The dose response to alcohol use of carbohydrate-deficient transferrin (CDT), gamma-glutamyltrans... more The dose response to alcohol use of carbohydrate-deficient transferrin (CDT), gamma-glutamyltransferase (GGT), and their combination (gamma-CDT) was studied in an age- and gender-stratified, random sample from Finland in 1997. A linear association with a threshold between alcohol consumption and the three markers was observed. Body mass index was negatively associated with CDT and positively with GGT Age was positively associated with GGT and gamma-CDT In conclusion, CDT appears to be an early phase marker of alcohol consumption. The combined marker, gamma-CDT, was less associated with factors such as body mass index but more strongly correlated with alcohol consumption than were the two markers separately.
Introduction: Recently, prognostic biomarkers have gained increasing interest in both human and v... more Introduction: Recently, prognostic biomarkers have gained increasing interest in both human and veterinary medicine. Chromogranin A (CgA) has been shown to be a useful prognostic biomarker for organ dysfunction in humans and a reliable diagnostic and prognostic biomarker for neuroendocrine tumors in both humans and dogs. CgA can be measured in both blood and saliva. As salivary collection is less invasive than blood collection, salivary samples could be an alternative method of collection, but the correlation between saliva and plasma levels of CgA has not been yet evaluated in dogs. Objective: The objective of this study was to investigate the correlation between CgA levels in saliva and plasma in healthy dogs. Materials and Methods: Blood and salivary samples were collected four times daily from five healthy beagle dogs over a 10 day-period. Salivary samples were collected by placing a polyether polyol swab on both buccal surfaces for 30 seconds. The samples were centrifuged at 3,...
The phase behavior of systems containing minimum amounts of sodium bis (2-ethylhexyl) sulfosuccin... more The phase behavior of systems containing minimum amounts of sodium bis (2-ethylhexyl) sulfosuccinate with equimolar ratio of tetra ethyl ammonium chloride were studied as a function of salt concentration and alkane carbon number at ambient temperature. Visual inspection as well as cross polarizers were used to detect anisotropy. Solubilization ratios for oil and brine in the middle phases were measured and used to calculate the interfacial tension. Ultra-low interfacial tension values were predicted for the systems containing heptane, octane and nonane as model oil. Different phase behavior was observed for systems with higher alkane number.
Background: Pyometra is potentially life-threatening and often leads to sepsis. Currently, there ... more Background: Pyometra is potentially life-threatening and often leads to sepsis. Currently, there are no precise diagnostic markers for identifying dogs with sepsis. Serum amyloid A (SAA) is a major acute phase protein in dogs. The aim of the present study was to explore the value of SAA analysis as a possible marker for sepsis in dogs with pyometra. Methods: Twenty-three septic and eight non-septic bitches undergoing ovariohysterectomy were included. Blood samples were collected prior to surgery. SAA analysis was performed with an ELISA test. Results: Mean (±SE) serum concentrations of SAA were significantly higher in septic (130.8 ± 8.0 mg/L) compared to non-septic bitches (88.5 ± 20.8 mg/mL). Conclusions: SAA concentrations were increased the septic dogs with pyometra and may be useful as an adjunctive diagnostic marker for sepsis. To evaluate the full potential of SAA as a marker for sepsis, further studies are warranted.
Biochemical markers can provide objective evidence of high alcohol consumption. However, currentl... more Biochemical markers can provide objective evidence of high alcohol consumption. However, currently available markers have limitations in their diagnostic performance. The diagnostic values of the most frequently used markers [carbohydrate-deficient transferrin (CDT), gamma-glutamyltransferase (GGT), aspartate aminotransferase, alanine aminotransferase, and mean corpuscular volume] were studied in an analysis of six different clinical studies (n = 1412) on alcohol abusers and social drinkers. The purpose of the analyses was to determine whether a combination of markers would improve the diagnosis of subjects. Discrimination between alcohol abusers and social drinkers, as measured by the areas under nonparametric ROC plots, was significantly better (P<0.001) for the new combined marker [gamma-CDT = 0.8. ln(GGT) + 1.3. ln(CDT)] than for any of the separate markers or combination of CDT or GGT with other markers. The cutoff values for gamma-CDT (6.5) can be taken to be the same among...
It has not yet been shown that ossification of ungular cartilages (OUC) is a pathological conditi... more It has not yet been shown that ossification of ungular cartilages (OUC) is a pathological condition. Beside heredity, factors such as sex, age, repeated concussion, local trauma, hoof and body size have been suggested as contributing factors for OUC development. By comparing radiographs of front hooves from cold-blooded trotters with different age we wanted to evaluate when development of OUC in cold-blooded trotters occurs and if and when it stabilizes in relation to age and workload. Diagnosis and grading of OUC were based on radiological field examinations of 649 Swedish and Norwegian cold-blooded trotters' front hooves. A hundred and forty-seven of the horses were re-examined 3-13 years (mean age 9, median 8 years) after the first occasion. All radiographs were evaluated blind, using two different grading systems for OUC. Work load, in form of number of races completed, and body size score were collected from official data. Four statistical ordinal regression models were use...
To investigate the physiologic reactions after removal of 1st ovary and whether this is repeated ... more To investigate the physiologic reactions after removal of 1st ovary and whether this is repeated during removal of the 2nd ovary in elective ovariohysterectomy. Prospective study. Dogs (n = 10). Dogs were premedicated with acepromazine, carprofen, and methadone and anesthetized with propofol and isoflurane. Blood pressure, heart rate, and end-tidal isoflurane concentration were measured every minute. The effects of various events during surgery on physiologic variables were analyzed using mixed linear models. Blood and urine samples were collected before anesthesia, before incision, before and after removal of ovaries with a 15 minute pause between ovary removal, and after abdominal closure. Plasma vasopressin and urinary noradrenalin and creatinine concentrations were analyzed. The magnitude of blood pressure increase at removal of the 1st ovary was greater than for the 2nd ovary because of an elevation in baseline. Similarly, the heart rate increased at the removal of the 1st ovary but not at removal of the 2nd ovary. Plasma vasopressin concentration increased at removal of both ovaries. Urinary noradrenalin/creatinine ratio increased at anesthesia, removal of both ovaries, and was elevated at closure of the abdomen. End-tidal isoflurane concentration did not change. Blood pressure and vasopressin concentrations changed in parallel using z-scores for comparison. Peak values for blood pressure, heart rate, plasma vasopressin concentration, and urinary noradrenalin/creatinine ratio did not differ between removals of the ovaries. Relative changes differed between repeated noxious stimuli, which should be considered in evaluation of methods at ovary removal.
Early diagnosis and appropriate treatment of pyometra is essential for a favorable outcome. The d... more Early diagnosis and appropriate treatment of pyometra is essential for a favorable outcome. The disease may have deadly consequences if sepsis develops. Sepsis, defined as systemic inflammatory response syndrome, SIRS, is caused by infection and is associated with increased morbidity and mortality rates in both veterinary and human medicine. Early diagnosis and treatment is crucial for survival. In female dogs with pyometra, the majority fulfil clinical criteria for sepsis. However, sepsis is difficult to diagnose since clinical findings are diffuse and bacterial blood culture results may take 24 hours and are not always reliable (due to contamination or no growth because of antimicrobial therapy). There is an urgent need of a rapid, sensitive and specific diagnostic test for early identification of sepsis. The aim of the present study was to evaluate concentrations of the inflammatory markers Serum amyloid A (SAA), C-reactive protein (CRP), and Insulin-like growth factor-I (IGF-I) ...
Horses with insect bite hypersensitivity (IBH) have difficulty in completely avoiding allergens, ... more Horses with insect bite hypersensitivity (IBH) have difficulty in completely avoiding allergens, so effective treatment options are required. A randomised, placebo controlled and double blinded field study was conducted to determine the pharmacokinetics and efficacy in reducing dermatitis of the antihistamine cetirizine given orally at 0.4 mg/kg twice daily for 3 weeks. The influence of protection blankets and stabling were also investigated. The estimated maximum plasma concentration (C(max)) and trough plasma concentration of cetirizine were 135 ng/mL and 18 ng/mL, respectively. There was no difference in dermatitis reduction between the treatment and placebo groups (P = 0.77). The findings indicated that cetirizine was of no apparent benefit in treating IBH at the dose rate tested. The use of blankets and stabling were shown to have favourable influence on the dermatitis (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) and may be the preferred options to prevent this condition.
Serum thymidine kinase (sTK) activity was evaluated as a tumor marker for canine malignant lympho... more Serum thymidine kinase (sTK) activity was evaluated as a tumor marker for canine malignant lymphoma (ML). The objective was to investigate if sTK, as in humans, could be used as a prognostic marker for survival time in dogs with ML and if sTK could identify early signs of progression of disease in treated dogs. Serum samples from 52 dogs with ML were tested for initial TK activity. Samples from 21 normal dogs and 25 dogs with nonhematologic neoplasms were used for comparison. Forty-four dogs with ML were treated. Serum TK activity was measured in treated dogs before each treatment and every 4 weeks thereafter until relapse. Dogs with ML had 2-180 times higher TK activity (TK 5-900 U/L) than normal dogs (TK &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;7 U/L) based on the mean + 2 standard deviations. In the group of other neoplasms, only 2 dogs had a moderate increase (6.4 and 7.5 U/L) compared with the controls. Mean sTK activities in the dogs with ML that had gone into complete remission (CR) were not significantly different from activities in healthy controls (P = .68). Mean sTK at least 3 weeks before and at the time of relapse was significantly higher than activity measured at CR (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .0001). Dogs with ML that initially had sTK &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;30 U/L had significantly shorter survival times (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .0001). Furthermore, sTK activity reflected the clinical staging of ML. Measuring sTK can be used as a powerful objective tumor marker for prognosis and for predicting relapse before recurrence of clinically detectable disease in dogs with ML undergoing chemotherapy.
In the dog, the normal estrous cycle includes a prolonged luteal phase. Progesterone stimulates l... more In the dog, the normal estrous cycle includes a prolonged luteal phase. Progesterone stimulates local canine mammary growth hormone (GH) production, which may act systemically and contribute to insulin resistance. Swedish Elkhounds are predisposed to progesterone-related diabetes mellitus, and the relationship among insulin resistance, GH, and insulin-like growth factor I (IGF-I) is of particular interest. To study insulin resistance in relation to GH and IGF-I in nondiabetic Swedish Elkhounds during diestrus. We also assessed whether alterations in these hormones could predict diestrus-linked diseases and all-cause mortality. Eighty-four privately owned female intact Swedish Elkhounds &gt;4 years of age. Blood sampling and clinical examination during luteal phase, with a follow-up questionnaire after 20 months. Insulin resistance was calculated by homeostasis model assessment (HOMA-IR). In multivariable regression analysis, GH was positively associated with HOMA-IR (P = .009). An increase in GH of 1 ng/mL was associated with a 12.7% increase in HOMA-IR. Moreover, C-peptide was positively associated with IGF-I (P = .04), and an increase in C-peptide of 0.1 ng/mL was associated with a 6.9% increase in IGF-I. Structural equation modeling supported these results. Twenty-three animals were found to have previously unrecognized mammary masses and had higher GH (P &lt; .0001) and IGF-I (P = .007) than dogs without mammary masses (n = 61). There was no association between high GH and IGF-I concentrations at sampling and future mammary masses. We showed that GH was strongly associated with insulin resistance in older Swedish Elkhounds during diestrus.
ABSTRACT Volatile chemical cues are used by herbivorous insects to locate and identify their host... more ABSTRACT Volatile chemical cues are used by herbivorous insects to locate and identify their host plants. Many species show a preference for volatiles experienced during development in the natal habitat. The reliability of this learnt information, however, may be limited. Many insects develop in restricted habitats, often on a single plant. Large between-plant variability in volatile emission, due to genetic differences and different exposure to biotic and abiotic factors, means that the volatile profile of a single plant may not be representative of the entire species. Insects must, therefore, balance the benefits of learning with the risks associated with its reliability. This is especially important for insects for which habitat exploration is costly. We hypothesize that information gained in the natal habitat is most likely to be utilized in situations where the cost of habitat exploration is lowest. To test this hypothesis, the black bean aphid, Aphis fabae, was reared on artificial diet while exposed to volatiles from its host, broad bean, and an unsuitable host, mustard. When offered the choice between bean and mustard leaves as adults, aphids showed a preference for the leaves whose odor they had experienced during development. When only exposed to volatiles from the two plants, in the absence of cues to indicate proximity or accessibility of the odor source, aphids preferred bean volatiles, regardless of experience. This suggests that information acquired from the natal habitat is only utilized when the perceived cost of habitat assessment is low, with innate preferences dominating otherwise.
The dose response to alcohol use of carbohydrate-deficient transferrin (CDT), gamma-glutamyltrans... more The dose response to alcohol use of carbohydrate-deficient transferrin (CDT), gamma-glutamyltransferase (GGT), and their combination (gamma-CDT) was studied in an age- and gender-stratified, random sample from Finland in 1997. A linear association with a threshold between alcohol consumption and the three markers was observed. Body mass index was negatively associated with CDT and positively with GGT Age was positively associated with GGT and gamma-CDT In conclusion, CDT appears to be an early phase marker of alcohol consumption. The combined marker, gamma-CDT, was less associated with factors such as body mass index but more strongly correlated with alcohol consumption than were the two markers separately.
Introduction: Recently, prognostic biomarkers have gained increasing interest in both human and v... more Introduction: Recently, prognostic biomarkers have gained increasing interest in both human and veterinary medicine. Chromogranin A (CgA) has been shown to be a useful prognostic biomarker for organ dysfunction in humans and a reliable diagnostic and prognostic biomarker for neuroendocrine tumors in both humans and dogs. CgA can be measured in both blood and saliva. As salivary collection is less invasive than blood collection, salivary samples could be an alternative method of collection, but the correlation between saliva and plasma levels of CgA has not been yet evaluated in dogs. Objective: The objective of this study was to investigate the correlation between CgA levels in saliva and plasma in healthy dogs. Materials and Methods: Blood and salivary samples were collected four times daily from five healthy beagle dogs over a 10 day-period. Salivary samples were collected by placing a polyether polyol swab on both buccal surfaces for 30 seconds. The samples were centrifuged at 3,...
The phase behavior of systems containing minimum amounts of sodium bis (2-ethylhexyl) sulfosuccin... more The phase behavior of systems containing minimum amounts of sodium bis (2-ethylhexyl) sulfosuccinate with equimolar ratio of tetra ethyl ammonium chloride were studied as a function of salt concentration and alkane carbon number at ambient temperature. Visual inspection as well as cross polarizers were used to detect anisotropy. Solubilization ratios for oil and brine in the middle phases were measured and used to calculate the interfacial tension. Ultra-low interfacial tension values were predicted for the systems containing heptane, octane and nonane as model oil. Different phase behavior was observed for systems with higher alkane number.
Background: Pyometra is potentially life-threatening and often leads to sepsis. Currently, there ... more Background: Pyometra is potentially life-threatening and often leads to sepsis. Currently, there are no precise diagnostic markers for identifying dogs with sepsis. Serum amyloid A (SAA) is a major acute phase protein in dogs. The aim of the present study was to explore the value of SAA analysis as a possible marker for sepsis in dogs with pyometra. Methods: Twenty-three septic and eight non-septic bitches undergoing ovariohysterectomy were included. Blood samples were collected prior to surgery. SAA analysis was performed with an ELISA test. Results: Mean (±SE) serum concentrations of SAA were significantly higher in septic (130.8 ± 8.0 mg/L) compared to non-septic bitches (88.5 ± 20.8 mg/mL). Conclusions: SAA concentrations were increased the septic dogs with pyometra and may be useful as an adjunctive diagnostic marker for sepsis. To evaluate the full potential of SAA as a marker for sepsis, further studies are warranted.
Biochemical markers can provide objective evidence of high alcohol consumption. However, currentl... more Biochemical markers can provide objective evidence of high alcohol consumption. However, currently available markers have limitations in their diagnostic performance. The diagnostic values of the most frequently used markers [carbohydrate-deficient transferrin (CDT), gamma-glutamyltransferase (GGT), aspartate aminotransferase, alanine aminotransferase, and mean corpuscular volume] were studied in an analysis of six different clinical studies (n = 1412) on alcohol abusers and social drinkers. The purpose of the analyses was to determine whether a combination of markers would improve the diagnosis of subjects. Discrimination between alcohol abusers and social drinkers, as measured by the areas under nonparametric ROC plots, was significantly better (P<0.001) for the new combined marker [gamma-CDT = 0.8. ln(GGT) + 1.3. ln(CDT)] than for any of the separate markers or combination of CDT or GGT with other markers. The cutoff values for gamma-CDT (6.5) can be taken to be the same among...
It has not yet been shown that ossification of ungular cartilages (OUC) is a pathological conditi... more It has not yet been shown that ossification of ungular cartilages (OUC) is a pathological condition. Beside heredity, factors such as sex, age, repeated concussion, local trauma, hoof and body size have been suggested as contributing factors for OUC development. By comparing radiographs of front hooves from cold-blooded trotters with different age we wanted to evaluate when development of OUC in cold-blooded trotters occurs and if and when it stabilizes in relation to age and workload. Diagnosis and grading of OUC were based on radiological field examinations of 649 Swedish and Norwegian cold-blooded trotters' front hooves. A hundred and forty-seven of the horses were re-examined 3-13 years (mean age 9, median 8 years) after the first occasion. All radiographs were evaluated blind, using two different grading systems for OUC. Work load, in form of number of races completed, and body size score were collected from official data. Four statistical ordinal regression models were use...
To investigate the physiologic reactions after removal of 1st ovary and whether this is repeated ... more To investigate the physiologic reactions after removal of 1st ovary and whether this is repeated during removal of the 2nd ovary in elective ovariohysterectomy. Prospective study. Dogs (n = 10). Dogs were premedicated with acepromazine, carprofen, and methadone and anesthetized with propofol and isoflurane. Blood pressure, heart rate, and end-tidal isoflurane concentration were measured every minute. The effects of various events during surgery on physiologic variables were analyzed using mixed linear models. Blood and urine samples were collected before anesthesia, before incision, before and after removal of ovaries with a 15 minute pause between ovary removal, and after abdominal closure. Plasma vasopressin and urinary noradrenalin and creatinine concentrations were analyzed. The magnitude of blood pressure increase at removal of the 1st ovary was greater than for the 2nd ovary because of an elevation in baseline. Similarly, the heart rate increased at the removal of the 1st ovary but not at removal of the 2nd ovary. Plasma vasopressin concentration increased at removal of both ovaries. Urinary noradrenalin/creatinine ratio increased at anesthesia, removal of both ovaries, and was elevated at closure of the abdomen. End-tidal isoflurane concentration did not change. Blood pressure and vasopressin concentrations changed in parallel using z-scores for comparison. Peak values for blood pressure, heart rate, plasma vasopressin concentration, and urinary noradrenalin/creatinine ratio did not differ between removals of the ovaries. Relative changes differed between repeated noxious stimuli, which should be considered in evaluation of methods at ovary removal.
Early diagnosis and appropriate treatment of pyometra is essential for a favorable outcome. The d... more Early diagnosis and appropriate treatment of pyometra is essential for a favorable outcome. The disease may have deadly consequences if sepsis develops. Sepsis, defined as systemic inflammatory response syndrome, SIRS, is caused by infection and is associated with increased morbidity and mortality rates in both veterinary and human medicine. Early diagnosis and treatment is crucial for survival. In female dogs with pyometra, the majority fulfil clinical criteria for sepsis. However, sepsis is difficult to diagnose since clinical findings are diffuse and bacterial blood culture results may take 24 hours and are not always reliable (due to contamination or no growth because of antimicrobial therapy). There is an urgent need of a rapid, sensitive and specific diagnostic test for early identification of sepsis. The aim of the present study was to evaluate concentrations of the inflammatory markers Serum amyloid A (SAA), C-reactive protein (CRP), and Insulin-like growth factor-I (IGF-I) ...
Horses with insect bite hypersensitivity (IBH) have difficulty in completely avoiding allergens, ... more Horses with insect bite hypersensitivity (IBH) have difficulty in completely avoiding allergens, so effective treatment options are required. A randomised, placebo controlled and double blinded field study was conducted to determine the pharmacokinetics and efficacy in reducing dermatitis of the antihistamine cetirizine given orally at 0.4 mg/kg twice daily for 3 weeks. The influence of protection blankets and stabling were also investigated. The estimated maximum plasma concentration (C(max)) and trough plasma concentration of cetirizine were 135 ng/mL and 18 ng/mL, respectively. There was no difference in dermatitis reduction between the treatment and placebo groups (P = 0.77). The findings indicated that cetirizine was of no apparent benefit in treating IBH at the dose rate tested. The use of blankets and stabling were shown to have favourable influence on the dermatitis (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) and may be the preferred options to prevent this condition.
Serum thymidine kinase (sTK) activity was evaluated as a tumor marker for canine malignant lympho... more Serum thymidine kinase (sTK) activity was evaluated as a tumor marker for canine malignant lymphoma (ML). The objective was to investigate if sTK, as in humans, could be used as a prognostic marker for survival time in dogs with ML and if sTK could identify early signs of progression of disease in treated dogs. Serum samples from 52 dogs with ML were tested for initial TK activity. Samples from 21 normal dogs and 25 dogs with nonhematologic neoplasms were used for comparison. Forty-four dogs with ML were treated. Serum TK activity was measured in treated dogs before each treatment and every 4 weeks thereafter until relapse. Dogs with ML had 2-180 times higher TK activity (TK 5-900 U/L) than normal dogs (TK &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;7 U/L) based on the mean + 2 standard deviations. In the group of other neoplasms, only 2 dogs had a moderate increase (6.4 and 7.5 U/L) compared with the controls. Mean sTK activities in the dogs with ML that had gone into complete remission (CR) were not significantly different from activities in healthy controls (P = .68). Mean sTK at least 3 weeks before and at the time of relapse was significantly higher than activity measured at CR (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .0001). Dogs with ML that initially had sTK &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;30 U/L had significantly shorter survival times (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .0001). Furthermore, sTK activity reflected the clinical staging of ML. Measuring sTK can be used as a powerful objective tumor marker for prognosis and for predicting relapse before recurrence of clinically detectable disease in dogs with ML undergoing chemotherapy.
In the dog, the normal estrous cycle includes a prolonged luteal phase. Progesterone stimulates l... more In the dog, the normal estrous cycle includes a prolonged luteal phase. Progesterone stimulates local canine mammary growth hormone (GH) production, which may act systemically and contribute to insulin resistance. Swedish Elkhounds are predisposed to progesterone-related diabetes mellitus, and the relationship among insulin resistance, GH, and insulin-like growth factor I (IGF-I) is of particular interest. To study insulin resistance in relation to GH and IGF-I in nondiabetic Swedish Elkhounds during diestrus. We also assessed whether alterations in these hormones could predict diestrus-linked diseases and all-cause mortality. Eighty-four privately owned female intact Swedish Elkhounds &gt;4 years of age. Blood sampling and clinical examination during luteal phase, with a follow-up questionnaire after 20 months. Insulin resistance was calculated by homeostasis model assessment (HOMA-IR). In multivariable regression analysis, GH was positively associated with HOMA-IR (P = .009). An increase in GH of 1 ng/mL was associated with a 12.7% increase in HOMA-IR. Moreover, C-peptide was positively associated with IGF-I (P = .04), and an increase in C-peptide of 0.1 ng/mL was associated with a 6.9% increase in IGF-I. Structural equation modeling supported these results. Twenty-three animals were found to have previously unrecognized mammary masses and had higher GH (P &lt; .0001) and IGF-I (P = .007) than dogs without mammary masses (n = 61). There was no association between high GH and IGF-I concentrations at sampling and future mammary masses. We showed that GH was strongly associated with insulin resistance in older Swedish Elkhounds during diestrus.
ABSTRACT Volatile chemical cues are used by herbivorous insects to locate and identify their host... more ABSTRACT Volatile chemical cues are used by herbivorous insects to locate and identify their host plants. Many species show a preference for volatiles experienced during development in the natal habitat. The reliability of this learnt information, however, may be limited. Many insects develop in restricted habitats, often on a single plant. Large between-plant variability in volatile emission, due to genetic differences and different exposure to biotic and abiotic factors, means that the volatile profile of a single plant may not be representative of the entire species. Insects must, therefore, balance the benefits of learning with the risks associated with its reliability. This is especially important for insects for which habitat exploration is costly. We hypothesize that information gained in the natal habitat is most likely to be utilized in situations where the cost of habitat exploration is lowest. To test this hypothesis, the black bean aphid, Aphis fabae, was reared on artificial diet while exposed to volatiles from its host, broad bean, and an unsuitable host, mustard. When offered the choice between bean and mustard leaves as adults, aphids showed a preference for the leaves whose odor they had experienced during development. When only exposed to volatiles from the two plants, in the absence of cues to indicate proximity or accessibility of the odor source, aphids preferred bean volatiles, regardless of experience. This suggests that information acquired from the natal habitat is only utilized when the perceived cost of habitat assessment is low, with innate preferences dominating otherwise.
Many plant species are able to perceive mechanical stimuli and respond with physiological, morpho... more Many plant species are able to perceive mechanical stimuli and respond with physiological, morphological or biochemical adjustments. Such changes in plant status may be detected by herbivory insects providing them with reliable cues about host plant quality. The broader ecological significance of induced plant responses to mechanical stimuli on herbivore insect behavior has not been explicitly investigated. In this study examined whether plant response to 1 min daily touching treatment over a period of 6 days affects olfactory response and host plant acceptance by the bird cherry-oat aphid Rhopalosiphum padi L. on maize and by the black bean aphid Aphis fabae Scop. on bean. Both tested aphid species showed significantly reduced acceptance of touched plants compared with untouched plants. Volatiles released by touched and untouched plants were collected and identified by gas chromatography-mass spectrometry (GC/MS). Stepwise discriminant analyses identified (E)-nerolidol and (E)-β-caryophyllene in maize and 6-methyl-5-hepten-2-one and an unidentified sesquiterpene in bean as the best discriminating compounds in the volatile profiles of touched plants. Olfactory bioassay demonstrated aphid avoidance of volatiles emitted by touched plants. Our study suggests that even brief mechanical stimuli can induce changes in plants that have potential to affect host plant selection and acceptance by aphids. The link between plant response to mechanical stimuli and insect behaviour identified in our study represents a new phenomenon that contributes to the broader ecological significance of induced plant responses to mechanical stress.
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