- Colima, Colima, Mexico
Valery Melnikov
Universidad de Colima, School of Medicine, Faculty Member
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Iron overload (IOL) increases the risk of diabetes mellitus (DM). Capsaicin (CAP), an agonist of transient receptor potential vanilloid-1 (TRPV1), reduces the effects of IOL. We evaluated the effects of chronic CAP administration on... more
Iron overload (IOL) increases the risk of diabetes mellitus (DM). Capsaicin (CAP), an agonist of transient receptor potential vanilloid-1 (TRPV1), reduces the effects of IOL. We evaluated the effects of chronic CAP administration on hepcidin expression, kidney iron deposits, and urinary biomarkers in a male Wistar rat model with IOL and DM (DM-IOL). IOL was induced with oral administration of iron for 12 weeks and DM was induced with streptozotocin. Four groups were studied: Healthy, DM, DM-IOL, and DM-IOL + CAP (1 mg·kg−1·day−1 for 12 weeks). Iron deposits were visualized with Perls tissue staining and a colorimetric assay. Serum hepcidin levels were measured with an enzyme-linked immunosorbent assay. Kidney biomarkers were assayed in 24 h urine samples. In the DM-IOL + CAP group, the total area of iron deposits and the total iron content in kidneys were smaller than those observed in both untreated DM groups. CAP administration significantly increased hepcidin levels in the DM-IOL...
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Doxycycline (Doxy) is an antibiotic, which has exhibited anti-inflammatory activity and glucose metabolism improvement. The present study was proposed to evaluate its effects on glucose metabolism and other associated processes, such as... more
Doxycycline (Doxy) is an antibiotic, which has exhibited anti-inflammatory activity and glucose metabolism improvement. The present study was proposed to evaluate its effects on glucose metabolism and other associated processes, such as lipemia and adipogenesis, as well as, to evaluate its effects on the liver, pancreas, and aorta in subjects fed with an occidental high-fat diet (HFD). The trial followed three groups of BALB/c mice for 6 months: (1) Standard diet (SD); (2) HFD-placebo (saline solution); and (3) HFD-Doxy (10 mg/kg/day). Intrahepatic fat accumulation (steatohepatosis) and the epididymal fat pad, as well as the hepatic inflammatory infiltrate and ALT serum levels were higher in both groups with the HFD (with/without doxycycline) in comparison with the SD group. The thickness of the aorta (preclinic atherosclerosis) was significantly elevated in the HFD group with respect to the HFD + Doxy and SD group, these two being similar groups to each other. The HFD-Doxy group ha...
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Rheumatoid arthritis is globally present in about 1% of the population. This autoinflammatory disease modifies the connective tissue, causing pain and inflammation of the joints. Over time, it causes the loss of joint cartilage and bone... more
Rheumatoid arthritis is globally present in about 1% of the population. This autoinflammatory disease modifies the connective tissue, causing pain and inflammation of the joints. Over time, it causes the loss of joint cartilage and bone mass, decreasing the patient's quality of life. Treatment options now available either give symptomatic alleviation or alter the disease process. Nonetheless, adherence to chronic treatment is typically limited due to adverse effects. As a result, new therapy approaches, such as systemic administration of neutral electrolyzed saline to improve patients’ quality of life, are being investigated. The study is a randomized prospective preclinical trial with a single-blind and a 4-arm parallel group using a collagen-induced mice model to generate rheumatoid arthritis. It was carried out on 36 male BALB/c mice, with the primary outcome measure being a scoring system for histopathologic assessment. When all groups are compared, there are significant dif...
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Background and objectives: Cardiac remodeling in pregnancy and postpartum is poorly understood. The aim of this study was to evaluate changes in cardiac fibrosis (pericardial, perivascular, and interstitial), as well as the expression of... more
Background and objectives: Cardiac remodeling in pregnancy and postpartum is poorly understood. The aim of this study was to evaluate changes in cardiac fibrosis (pericardial, perivascular, and interstitial), as well as the expression of matrix metalloproteinases (MMP-1, MMP-2, and MMP-9) and their inhibitors (Tissue inhibitors of metalloproteinases, TIMP-1 and TIMP-4) during late pregnancy and postpartum in rat left ventricle. Materials and Methods: Female Sprague–Dawley rats were used for this study. Rats were divided three groups: non-pregnant, late pregnancy, and postpartum. The heart was weighed and cardiac fibrosis was studied by conventional histological procedures. The expression and transcript level of target proteins were evaluated using immunoblot techniques and quantitative PCR. Results: The experiments showed an increase of perivascular, pericardial, and interstitial fibrosis in heart during pregnancy and its reversion in postpartum. Moreover, in late pregnancy, MMP-1, ...
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Inflammation is an essential component of prostate cancer (PCa), and mefenamic acid has been reported to decrease its biochemical progression. The current standard therapy for PCa is androgen deprivation therapy (ADT), which has side... more
Inflammation is an essential component of prostate cancer (PCa), and mefenamic acid has been reported to decrease its biochemical progression. The current standard therapy for PCa is androgen deprivation therapy (ADT), which has side effects such as cognitive dysfunction, risk of Alzheimer's disease, and dementia. Published results of in vitro tests and animal models studies have shown that mefenamic acid could be used as a neuroprotector. Objective: Examine the therapeutic potential of mefenamic acid in cognitive impairment used in a controlled clinical trial. Clinical trial phase II was conducted on patients undergoing ADT for PCa. Two groups of 14 patients were included. One was treated with a placebo, while the other received mefenamic acid 500 mg PO every 12hrs for six months. The outcome was evaluated through the Mini-Mental State Examination (MMSE) score at six months. At the beginning of the study, both groups had similar MMSE scores (mefenamic acid vs. placebo: 26.0±2.5...
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During phase 2 of the COVID-19 pandemic in a Mexican City, informal street vendors (cases) and formal employees (controls) were interviewed. A total of 82.6% of street vendors preferred to expose themselves to the coronavirus than to stop... more
During phase 2 of the COVID-19 pandemic in a Mexican City, informal street vendors (cases) and formal employees (controls) were interviewed. A total of 82.6% of street vendors preferred to expose themselves to the coronavirus than to stop working, compared with 18.4% of formal employees (adjusted OR = 19.4, 95%CI: 4.6-81.7, p < 0.001). Street vendors had 7 times less fear of dying from coronavirus (adjusted OR = 0.14, 95% CI: 0.03-0.5, p = 0.005) and showed a 16-times greater lack of real concern for the increase in cases in their community than the formal employees (adjusted OR = 0.06, 95% CI: 0.01-0.3, p = 0.002). Street vendors were the group with the poorest adherence to household and work area containment measures that continued to be in contact with others. The corresponding authorities must plan specific strategies that allow street vendors to survive economically, while at the same time, protecting community health.
Introduction: Due to the coronavirus pandemic, identifying the infected individuals has become key to limiting its spread. Virus nucleic acid real-time RT-PCR testing has become the current standard diagnostic method but high demand could... more
Introduction: Due to the coronavirus pandemic, identifying the infected individuals has become key to limiting its spread. Virus nucleic acid real-time RT-PCR testing has become the current standard diagnostic method but high demand could lead to shortages. Therefore, we propose a detection strategy using a one-step nested RT-PCR. Methodology: The nucleotide region in the ORF1ab gene that has the greatest differences between the human coronavirus and the bat coronavirus was selected. Primers were designed after that sequence. All diagnostic primers are species-specific since the 3´ end of the sequence differs from that of other species. A primer set also creates a synthetic positive control. Amplified products were seen in a 2.5% agarose gel, as well as in an SYBR Green-Based Real-Time RT-PCR. Results: Amplification was achieved for the positive control and specific regions in both techniques. Conclusions: This new technique is flexible and easy to implement. It does not require a r...
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Background: Coronavirus disease (COVID-19) is currently the main public health problem worldwide. The administration of neutral electrolyzed saline, a solution that contains reactive species of chlorine and oxygen (ROS), may be an... more
Background: Coronavirus disease (COVID-19) is currently the main public health problem worldwide. The administration of neutral electrolyzed saline, a solution that contains reactive species of chlorine and oxygen (ROS), may be an effective therapeutic alternative due to its immunomodulating characteristics, in systemic inflammation control, as well as in immune response improvement, promoting control of the viral infection. The present study evaluated the efficacy of treatment with intravenous and/or nebulized neutral electrolyzed saline combined with usual medical care versus usual medical care alone, in ambulatory patients with COVID-19.Methods: A prospective, 2-arm, parallel group, randomized, open-label, phase I-II clinical trial included 39 patients in the control group (usual medical care alone) and 45 patients in the experimental group (usual medical care + intravenous and/or nebulized electrolyzed saline, with dose escalation). Two aspects were evaluated during the twenty-d...
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Esteatose Hepatica Nao Alcoolica Relacao Com a Sindrome Metabolica e Os Fatores De Risco Cardiovascular Em Adolescentes Obesos Nonalcoholic Hepatic Steatosis Association with Metabolic Syndrome and Cardiovascular Risk Factors in Obese Adolescents Esteatosis Hepatica No Alcoholica Relacion Con El ...more
This study aimed to examine the effects of moderate (MIT) and high-intensity training (HIT) chronic exercise on plasma tumor necrosis factor alpha (TNF-α) level and its impact on Langerhans islet morphology in healthy rats. Two-month old... more
This study aimed to examine the effects of moderate (MIT) and high-intensity training (HIT) chronic exercise on plasma tumor necrosis factor alpha (TNF-α) level and its impact on Langerhans islet morphology in healthy rats. Two-month old normal male Wistar rats were divided into three groups: control (C, n=6), MIT (n=6), and HIT (n=4). The training protocol consisted in 24 sessions of running on a treadmill at 60-80% maximal oxygen consumption (VO2max) for MIT, and >80% VO2max for HIT. TNF-α and insulin were measured with ELISA tests. Duodenal pancreas was dissected to analyze the Langerhans islets by immunohistochemistry, a correlation analysis was performed with the nuclei/total islet area. Results: HIT and MIT rats showed lower TNF-α plasma levels than controls. Plasma insulin level decreased significantly in HIT compared with C and MIT. In addition, the islet area and nuclei density per islet were higher in the exercise groups compared with C. However, none of the groups show...
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Mefenamic acid is a non‑steroidal anti‑inflammatory drug exhibiting a wide range of anti‑inflammatory, antipyretic, analgesic and probable antiviral activities. The present study evaluated the efficacy of treatment with mefenamic acid... more
Mefenamic acid is a non‑steroidal anti‑inflammatory drug exhibiting a wide range of anti‑inflammatory, antipyretic, analgesic and probable antiviral activities. The present study evaluated the efficacy of treatment with mefenamic acid combined with standard medical care vs. standard medical care plus a placebo in ambulatory patients with coronavirus disease 2019 (COVID‑19; nasal/oropharyngeal swabs reverse transcription‑PCR test results positive for severe acute respiratory syndrome coronavirus 2). The present study is a phase II prospective, two‑arm, parallel‑group, randomized, double‑blind placebo‑controlled clinical trial which analyzed 36 patients. Two aspects were evaluated during the 14‑day follow‑up period: i) The time for reaching a patient acceptable symptom state (PASS), and ii) the last day of each COVID‑19 symptom presentation. Adverse effects were evaluated. The clinical severity for all the patients in the study was mild (88.9%) and moderate (11.1%). The control (placebo) group achieved PASS on day 8.0±1.3, compared with day 4.4±0.8 in the mefenamic acid group (P=0.020, Kaplan‑Meier analyses using log‑rank tests). Patients that received mefenamic acid plus standard medical care had a ~16‑fold higher probability of achieving PASS on day 8 (adjusted RR, 15.57; 95% CI, 1.22‑198.71; P=0.035), compared with the placebo plus standard medical care group. All symptoms lasted for fewer days in the mefenamic acid group, compared with the placebo group; however, only the symptoms of headache (P=0.008), retro‑orbital eye pain (P=0.049), and sore throat (P=0.029) exhibited statistically significant differences. The experimental treatment produced no severe adverse effects. On the whole, the present study demonstrates that the administration of mefenamic acid markedly reduced the symptomatology and time to reach PASS in ambulatory patients with COVID‑19. Due to its probable antiviral effects and potent anti‑inflammatory mechanisms, mefenamic acid may prove to be useful in the treatment of COVID‑19, in combination with other drugs, including the new antivirals (remdesivir, molnupiravir, or favipiravir). However, future studies are also required to confirm these findings.
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Centruroides tecomanus is a medically important scorpion of the state of Colima (Mexico). This communication reports the identification of venom components of this scorpion with biological activity over insects/crickets (Acheta... more
Centruroides tecomanus is a medically important scorpion of the state of Colima (Mexico). This communication reports the identification of venom components of this scorpion with biological activity over insects/crickets (Acheta domestica), crustaceans/fresh water shrimps (Cambarellus montezumae), and mammalians/mice (Mus musculus, strain CD1). It also describes the pharmacological effects on cell lines in culture (L5178Y cells, HeLa cells, HuTu cells and Jurkat E6-1 cells), as well as on several types of bacteria (see below). The soluble venom of this scorpion was fractionated by high-performance liquid chromatography (HPLC) and collected separately in twelve independent fractions collected over 60 min run (5 min time apart each other). The HPLC components of fraction VII were lethal to all three species used for assay. The IVth fraction had a toxic effect on freshwater shrimps. In this species, fractions VI, VII and VIII were all lethal. For crickets, fractions V and VI were toxic ...
Research Interests: Biology, Drug Discovery, Apoptosis, Medicine, Mexico, and 15 moreSpleen, Insecticides, Humans, Animal venoms and toxins, Mice, Animals, Staphylococcus aureus, SCORPIONS, Microbial Sensitivity Tests, MEXICO, Amino Acid Sequence, Antineoplastic Agents, Toxicon, Gryllidae, and Pharmacology and pharmaceutical sciences
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Alzheimer pathogenesis involves mitochondrial dysfunction, which is closely related to amyloid-ß(Aß) generation, abnormal tau phosphorylation, oxidative stress, and apoptosis. Alterations in membranal components, including cholesterol and... more
Alzheimer pathogenesis involves mitochondrial dysfunction, which is closely related to amyloid-ß(Aß) generation, abnormal tau phosphorylation, oxidative stress, and apoptosis. Alterations in membranal components, including cholesterol and fatty acids, their characteristics, disposition, and distribution along the membranes, have been studied as evidence of cell membrane alterations in AD brain. The majority of these studies have been focused on the cytoplasmic membrane; meanwhile the mitochondrial membranes have been less explored. In this work, we studied lipids and mitochondrial membranesin vivo, following intracerebral injection of fibrillar amyloid-ß(Aß). The purpose was to determine how Aßmay be responsible for beginning of a vicious cycle where oxidative stress and alterations in cholesterol, lipids and fatty acids, feed back on each other to cause mitochondrial dysfunction. We observed changes in mitochondrial membrane lipids, and fatty acids, following intracerebral injectio...
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Amyloid-beta(Aβ) pathology is related to mitochondrial dysfunction accompanied by energy reduction and an elevated production of reactive oxygen species (ROS). Monomers and oligomers of Aβ have been found inside mitochondria where they... more
Amyloid-beta(Aβ) pathology is related to mitochondrial dysfunction accompanied by energy reduction and an elevated production of reactive oxygen species (ROS). Monomers and oligomers of Aβ have been found inside mitochondria where they accumulate in a time-dependent manner as demonstrated in transgenic mice and in Alzheimer’s disease (AD) brain. We hypothesize that the internalization of extracellular Aβ aggregates is the major cause of mitochondrial damage and here we report that following the injection of fibrillar Aβ into the hippocampus, there is severe axonal damage which is accompanied by the entrance of Aβ into the cell. Thereafter, Aβ appears in mitochondria where it is linked to alterations in the ionic gradient across the inner mitochondrial membrane. This effect is accompanied by disruption of subcellular structure, oxidative stress, and a significant reduction in both the respiratory control ratio and in the hydrolytic activity of ATPase. Orally administrated melatonin r...
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Research Interests: Skeletal muscle biology, Immunohistochemistry, Multidisciplinary, Insulin Resistance, Insulin, and 13 moreLiver, Animals, Male, ROC Curve, PLoS one, Rats, Wistar Rats, Glucose Tolerance Test, Glycogen, Area Under Curve, islets of Langerhans, Phisiology of pancreas, and Brain-derived neurotrophic factor (BDNF)
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Previous work has shown that the carotid body glomus cells can function as glucose sensors. The activation of these chemoreceptors, and of its afferent nucleus in the brainstem (solitary tract nucleus - STn), induces rapid changes in... more
Previous work has shown that the carotid body glomus cells can function as glucose sensors. The activation of these chemoreceptors, and of its afferent nucleus in the brainstem (solitary tract nucleus - STn), induces rapid changes in blood glucose levels and brain glucose retention. Nitric oxide (NO) in STn has been suggested to play a key role in the processing of baroreceptor signaling initiated in the carotid sinus. However, the relationship between changes in NO in STn and carotid body induced glycemic changes has not been studied. Here we investigated in anesthetized rats how changes in brain glucose retention, induced by the local stimulation of carotid body chemoreceptors with sodium cyanide (NaCN), were affected by modulation of NO levels in STn. We found that NO donor sodium nitroprusside (SNP) micro-injected into STn completely blocked the brain glucose retention reflex induced by NaCN chemoreceptor stimulation. In contrast, NOS inhibitor N(ω)-nitro-L-arginine methyl ester (L-NAME) increased brain glucose retention reflex compared to controls or to SNP rats. Interestingly, carotid body stimulation doubled the expression of nNOS in STn, but had no effect in iNOS. NO in STn could function to terminate brain glucose retention induced by carotid body stimulation. The work indicates that NO and STn play key roles in the regulation of brain glucose retention.
Research Interests: Biological Sciences, Brain, Glucose, Blood Glucose, Nitric oxide, and 15 moreAnimals, Male, Anesthesia, CHEMICAL SCIENCES, Brain Glucose Uptake, Rats, Nitric Oxide Synthase, Wistar Rats, Carotid Body, Methyl Ester, Sodium Cyanide, Nitric oxide donors, Sodium Nitroprusside, nitroprusside, and Medical and Health Sciences
Carotid body chemoreceptors function as glucose sensors and contribute to glucose homeostasis. The nucleus tractus solitarii (NTS) is the first central nervous system (CNS) nuclei for processing of information arising in the carotid body.... more
Carotid body chemoreceptors function as glucose sensors and contribute to glucose homeostasis. The nucleus tractus solitarii (NTS) is the first central nervous system (CNS) nuclei for processing of information arising in the carotid body. Here, we microinjected a nitric oxide (NO) donor sodium nitroprusside (SNP), an NO-independent activator of the soluble guanylyl cyclase (sGC) (YC₁) or an NO-synthase (NOS) inhibitor Nω-nitro-l-arginine methyl ester (L-NAME) into the commissural NTS (cNTS) before carotid chemoreceptor anoxic stimulation and measured arterial glucose and the expression of Fos-like immunoreactivity (Fos-ir). Male Wistar rats (250-300 g) were anesthetized, and the carotid sinus was vascularly isolated. Either artificial cerebrospinal fluid (aCSF), SNP, YC₁ or L-NAME were stereotaxically injected into the cNTS. The SNP and YC₁ infused into the cNTS before carotid chemoreceptor stimulation (SNP-2 and YC₁-2 groups) similarly increased arterial glucose compared to the aCSF-2 group. By contrast, infusion of L-NAME into the cNTS before carotid chemoreceptor stimulation (L-NAME-2 group) decreased arterial glucose concentration. The number of cNTS Fos-ir neurons, determined in all the groups studied except for YC₁ groups, significantly increased in SNP-2 rat when compared to the aCSF-2 or SNP-2 groups. Our findings demonstrate that NO signaling, and the correlative activation of groups of cNTS neurons, plays key roles in the hyperglycemic reflex initiated by carotid chemoreceptor stimulation.
Research Interests: Chemistry, Medicine, Biological Sciences, Anoxia, Glucose, and 15 moreHyperglycemia, Blood Glucose, Nitric oxide, Animals, Male, Neurons, CHEMICAL SCIENCES, Rats, Homeostasis, Carotid Body, Gene Expression Regulation, Nitric oxide donors, Carotid Arteries, nitroprusside, and Medical and Health Sciences
A high-fat diet and male obesity are aspects associated with germinal epithelial alterations and male infertility. Some reports have shown that certain tetracyclines can protect the germinal epithelium from toxic drugs. The aim of the... more
A high-fat diet and male obesity are aspects associated with germinal epithelial alterations and male infertility. Some reports have shown that certain tetracyclines can protect the germinal epithelium from toxic drugs. The aim of the present study design was to evaluate the possible effect of doxycycline on testicular germ cells in individuals fed a Western diet (atherogenic), using a murine model. Two groups of male mice (BALB/c) were fed a high-fat Western diet (HFD). One of these two groups was given doxycycline at a dose of 10 mg/kg/day (HFD+Dox). A third group was fed a standard rodent diet (SD group). After 6 months, the mice were euthanized and morphologic and histopathologic analyses were performed. Germinal epithelial height was similar between the SD group (54 μm) and the HFD+Dox group (53 μm) (p = 0.26), and it was significantly reduced in the HFD group (47 μm) (p = 0.0001). The degree of germinal epithelial loss (DGEL) was significantly lower in the SD (10) and HFD+Dox (12.5) groups than in the HFD group (30) (p = 0.0001 and =0.007, respectively). There were no differences in the DGEL between the SD and HFD+Dox groups (p = 0.42). Doxycycline administration was shown to prevent germinal epithelial loss in the testes of mice fed a high-fat diet. Future studies are necessary to evaluate the clinical usefulness of doxycycline or its analogs in persons with a habitual high-fat diet.
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Go to AGRIS search. Genes and Genomics (Dec 2008). A Polymorphism in the Matrix Metalloproteinase-2 (MMP-2-1306T greater than C) Gene Promoter is Associated with High Risk of Ischemic Stroke in Hypertensive Patients. ...
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The aim of this randomized, double-blind clinical trial was to determine the effectiveness of systemic antibiotic application followed by either topical ionized solution (IS) or topical saline solution (placebo) as surgical site infection... more
The aim of this randomized, double-blind clinical trial was to determine the effectiveness of systemic antibiotic application followed by either topical ionized solution (IS) or topical saline solution (placebo) as surgical site infection (SSI) prophylaxis in appendectomy for non-perforated appendicitis. Prophylactic antibiotic was administered pre-incision and either topical IS or placebo was applied pre-suturing to 529 patients, who were then monitored for 30 days. When topical IS was used, SSI relative risk was 0.739 (95% CI 0.537, 1.019) and the SSI prevention rate was 26.06% (CI −1.8%, 46.3%). The number needed to treat was 14.80 patients and the number needed to harm was 209 in order for SSI to be avoided. In conclusion, there was a trend for topical IS prophylaxis to reduce SSI frequency in patients undergoing appendectomy for non-perforated appendicitis, but the result was not statistically significant.
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The action of matrix metalloproteinases (MMPs) can weaken the arterial wall, contributing to the destabilizing and rupture of atheromatous plaque. Within the MMPs, type 2 stands out due to its action on basement membrane constituents.... more
The action of matrix metalloproteinases (MMPs) can weaken the arterial wall, contributing to the destabilizing and rupture of atheromatous plaque. Within the MMPs, type 2 stands out due to its action on basement membrane constituents. Previous studies have revealed elevated levels of MMP-2 in the acute phase of ischemic stroke (IS). An MMP-2 single nucleotide polymorphism, -1306T>C (rs243865), displayed strikingly high promoter activity with the C allele. Our study analyzed whether or not the MMP-2-1306T>C polymorphism contributed to the development of IS in a Mexican population. Ninety-eight patients with IS and 213 control subjects were analyzed. Genomic DNA isolation, polymerase chain reaction (PCR), and polymorphism detection by restriction enzyme digestion were performed to detect MMP-2-1306T>C polymorphism. An increased probability of IS associated with the MMP-2 CC genotype (OR, 1.70; 95% CI, 1.02-2.85) was found. IS risk associated with the CC genotype was more pron...
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Dengue epidemics remain as a priority public health problem especially in tropical countries. Mainly the presence of dengue hemorrhagic fever or other severe forms of the disease represent the greatest social and economic burdens to... more
Dengue epidemics remain as a priority public health problem especially in tropical countries. Mainly the presence of dengue hemorrhagic fever or other severe forms of the disease represent the greatest social and economic burdens to affected populations. These costs are even greater when dealing with younger populations, as occurs in Southeast Asian countries where rates of severe dengue are highest amongst newborns and little infants. One possible explanation for this phenomenon * Facultad de Medicina, Universidad de Colima. Correspondencia: Dr. Francisco Espinoza Gomez, Facultad de Medicina de la Universidad de Colima, Avenida Universidad 333, colonia las Viboras, Colima, Col. C.P. 28040; e mail: fespin@ucol.mx. † Estudiante de la Facultad de Medicina de la Universidad Autonoma de Sinaloa.
INTRODUCTION The present study was conducted to estimate the incidence of seropositivity to anti-Trypanosoma cruzi antibodies and analyze potential risk factors in Colima, on the western coast of Mexico. METHODOLOGY Longitudinal studies... more
INTRODUCTION The present study was conducted to estimate the incidence of seropositivity to anti-Trypanosoma cruzi antibodies and analyze potential risk factors in Colima, on the western coast of Mexico. METHODOLOGY Longitudinal studies of 209 subjects with negative serology in 1999 for anti-Trypanosoma cruzi antibodies by hemagglutination inhibition test were tested again in 2005. At the same time, 716 children under six years of age were surveyed serologically (total n = 925); the history of Trypanosoma cruzi infection was determined by the same hemagglutination inhibition test. The variables analyzed were age, sex, living in triatomine-infested places, type of community, quality of housing, presence of pets, and number of inhabitants per house. RESULTS Trypanosoma cruzi seropositivity in the period of six years was 22/925 cases, with a point prevalence of 2.73% and an adjusted rate of 7.3/1,000 person-years. The variable living in triatomine-infested areas showed association with...
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Introduction: COVID-19 pandemic affects human health and the global economy. Its evolution is unpredictable, making it hard for governments to provide response actions suited for all populations. Meanwhile, informal street workers carry... more
Introduction: COVID-19 pandemic affects human health and the global economy. Its evolution is unpredictable, making it hard for governments to provide response actions suited for all populations. Meanwhile, informal street workers carry on with their labor despite contingency measures to sustain their lives. The objective was to conduct a case-control study to become aware of how street vendors' economy is affected during the COVID-19 pandemic. Methodology: During phase 2 of the COVID-19 pandemic in a Mexican suburban city. We interviewed informal street vendors (cases) and formal employees (controls). Results: Before mobility restrictions were in place, population income came 1.5% from formal employment and 23.5% from informal employment (street vendors). Informal employees lived on less than the equivalent of 1.5 Big Macs per day (p <0.001). After the contingency measures, formal employment kept the same, while the informal employment ratio increased to 57.4% (p < 0.001)...
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Arthralgia is a potentially incapacitating condition and a persistent symptom in chronic or acute episodes of Chikungunya fever caused by infection with the Chikungunya virus (CHIKV). To the best of our knowledge, there are no reports on... more
Arthralgia is a potentially incapacitating condition and a persistent symptom in chronic or acute episodes of Chikungunya fever caused by infection with the Chikungunya virus (CHIKV). To the best of our knowledge, there are no reports on risk factors associated with the intensity of arthralgias in typical acute episodes of the disease. Although a number of studies have reported on risk factors associated with the development of the chronic stage of the disease, smoking habits have not been analyzed. Smoking is an interesting factor to consider since it is the main environmental risk factor for the development of rheumatoid arthritis (RA), a similar disease to CHIKV in many aspects. In the present study, 140 patients infected with CHIKV were assessed for risk factors associated with severe arthralgia intensity in the acute phase (pain of 9/10 on the visual analog scale of 0-10) and moderate to severe intensity (according to the Routine Assessment of Patient Index Data 3) 3.5 months a...
Leptin is a protein hormone that plays a key role in the regulation of energy balance and glucose homeostasis. Leptin and all leptin receptor isoforms are present in the carotid bodies, but its precise function in glucose regulation and... more
Leptin is a protein hormone that plays a key role in the regulation of energy balance and glucose homeostasis. Leptin and all leptin receptor isoforms are present in the carotid bodies, but its precise function in glucose regulation and metabolism is not yet known. The aim of this study was to determine whether exogenous leptin, microinjected into the commissural nucleus tractus solitarii (cNTS), preceding sodium cyanide (NaCN) injection into the circulatory isolated carotid sinus (ICS), in vivo, modifies hyperglycemic reflex (HR) and brain glucose retention (BGR). In anesthetized Wistar rats (sodium pentobarbital, i.p. 3.3 mg/100 g/saline, Pfizer, Mex), arterial and venous blood samples were collected from silastic catheters implanted in the abdominal aorta and jugular sinus. Exogenous leptin (50 ng/20 nL of aCSF) or leptin vehicle (20 nL of aCSF) microinjected (stereotaxically) into the cNTS 4 min before NaCN (5 μg/100 g/50 μL saline into ICS) (experimental 1 [E1] and control 1[C1...
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Dengue virus (DENV) is currently considered as one of the most important mosquito-borne viral pathogens affecting humans. Genetic variations in viruses are likely to be a condition for more effective evasion of the immune system and... more
Dengue virus (DENV) is currently considered as one of the most important mosquito-borne viral pathogens affecting humans. Genetic variations in viruses are likely to be a condition for more effective evasion of the immune system and resulting in severe clinical consequences. The DENV‑1 NS5 gene was sequenced to establish whether during an epidemic burst there were genetic variations of the virus and whether any variant was associated (through a case‑control design) with severe clinical behavior. A total of 31 patients positive for DENV‑1 were enrolled. Among the nucleotide differences between the sequences, only two generated amino acid changes. The variants 124Met/166Ser (amino acid positions according to the report GenBank AJL35015.1), were associated with a severe clinical course of the disease. Via in silico tests, it was identified that the variations generate changes in the protein probably affecting the function of type‑1 interferon, either at the level of its receptor or by ...
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The repeated injection of insulin (unconditioned stimulus, UCS) immediately followed by exposure to sensory stimulation (e.g. sound or odor; conditioned stimulus, CS) results in a learned conditioned reflex in which the exposure to the CS... more
The repeated injection of insulin (unconditioned stimulus, UCS) immediately followed by exposure to sensory stimulation (e.g. sound or odor; conditioned stimulus, CS) results in a learned conditioned reflex in which the exposure to the CS alone lowers blood glucose. The brain regions participating in this hypoglycemic Pavlovian response remain unknown. Here we investigate if nitric oxide (NO) in the nucleus tractus solitarius (NTS), a nucleus known to be involved in glucose homeostasis, participates in this hypoglycemic reflex. Insulin injections (UCS) were paired with exposure to menthol odor (CS). After 8-10 reinforcements (4-5days training), rats acquire the learned hypoglycemic response. An increase in c-Fos expression was observed in the NTS, the ventrolateral hypothalamic nucleus (VLH) and other brain regions of conditioned rats. Microinjections of 3-(5'-hydroxymethyl-2'furyl)-1-benzyl indazole (YC-1) a stimulator of soluble guanylate cyclase (sGC) into NTS before the ...
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The present study was conducted to estimate the incidence of seropositivity to anti-Trypanosoma cruzi antibodies and analyze potential risk factors in Colima, on the western coast of Mexico. Longitudinal studies of 209 subjects with... more
The present study was conducted to estimate the incidence of seropositivity to anti-Trypanosoma cruzi antibodies and analyze potential risk factors in Colima, on the western coast of Mexico. Longitudinal studies of 209 subjects with negative serology in 1999 for anti-Trypanosoma cruzi antibodies by hemagglutination inhibition test were tested again in 2005. At the same time, 716 children under six years of age were surveyed serologically (total n = 925); the history of Trypanosoma cruzi infection was determined by the same hemagglutination inhibition test. The variables analyzed were age, sex, living in triatomine-infested places, type of community, quality of housing, presence of pets, and number of inhabitants per house. Trypanosoma cruzi seropositivity in the period of six years was 22/925 cases, with a point prevalence of 2.73% and an adjusted rate of 7.3/1,000 person-years. The variable living in triatomine-infested areas showed association with seropositivity anti-Trypanosoma ...
Research Interests:
Chagas&amp;amp;amp;amp;amp;amp;amp;amp;#39; disease is caused by unicellular parasite Trypanosoma cruzi (T. cruzi). It is endemic throughout Latin America, but nowadays has become a global challenge due to tourism and migration.... more
Chagas&amp;amp;amp;amp;amp;amp;amp;amp;#39; disease is caused by unicellular parasite Trypanosoma cruzi (T. cruzi). It is endemic throughout Latin America, but nowadays has become a global challenge due to tourism and migration. Non-treated infection may result in health-threatening complications and lead to death. Current medications for this infection are nifurtimox (NFT) and benznidazol. Both drugs may cause side effects and are ineffective in the chronic phase. Therefore, new antichagasic compounds are urgently required. Nitazoxanide (NTZ) is a broad spectrum antiparasitic drug, proposed recently as a potential candidate to be added to the list of essential medicines for integrated neglected tropical disease control and elimination. Although the effect of NTZ against T. cruzi epimastigotes in vitro was reported, the corresponding experiments in animal models of T. cruzi infection have never been undertaken. The present work was designed to fill this gap and evaluate the effect of NTZ on experimental murine trypanosomiasis, in comparison with classical antichagasic agent NFT. Highly sensitive to T. cruzi BALB/c mice were infected using Albarrada T. cruzi strain, recently isolated in Mexico. Experimental groups were either left untreated, or otherwise treated with NFT, NTZ (100 and 1000 mg/kg), or with both drugs simultaneously. The severity of the infection was estimated based on criteria such as parasitemia, lesions in target tissues (heart, muscles and lungs) and mortality. Despite the expected protective effect, NTZ drastically aggravates the course of T. cruzi infection. Namely, parasitemia, tissue lesions and mortality caused by T. cruzi infection were significantly higher in NTZ-treated mice groups, even in comparison with untreated infected animals. NTZ by itself no produced mortality o tissue damage, and NFT showed an expected protective effect. Our results indicate that NTZ cannot be considered for Chagas&amp;amp;amp;amp;amp;amp;amp;amp;#39; disease treatment. Moreover, NTZ should be used with caution in patients positive for T. cruzi infection.