Amino groups of human serum albumin (HSA) can react non-enzymatically with carbonyl groups of red... more Amino groups of human serum albumin (HSA) can react non-enzymatically with carbonyl groups of reducing sugars to form advanced glycation end products (AGEs). These AGEs contribute to many of the chronic complications of diabetes including atherosclerosis, cataract formation and renal failure. The current study focused on in vitro non-enzymatic reactivity of glyceraldehyde (GA) and methylglyoxal (MG) with HSA and evaluated the rate and extent of AGE formation in the presence of varied concentrations of Zn(II). At normal physiological conditions, GA and MG readily react with HSA. The presence of Zn(II) in HSA-GA or HSA-MG incubation mixtures reduced AGE formation. This finding was confirmed by UV and fluorescence spectrometry, HPLC techniques, and matrix assisted laser desorption ionization mass spectrometry (MALDI-TOF). HPLC studies revealed decreased adduct formation of the glycated protein in the presence of Zn(II). The inhibition of AGE formation was intense at elevated Zn(II) concentrations. The results of this study suggest that Zn(II) may prove to be a potent agent in reducing AGE formation.
Hemorrhagic shock (HS) often causes coagulopathy due, in part, to decreased coagulation proteins.... more Hemorrhagic shock (HS) often causes coagulopathy due, in part, to decreased coagulation proteins. This study assessed the efficacy of fresh frozen plasma (FFP) in preventing this coagulopathy following a canine model of HS designed to mimic bleeding with shock as seen in the emergency department followed by bleeding without shock as seen during operation for control of bleeding. Twenty-two dogs had acute HS for 2 hours followed by resuscitation with red blood cells (RBC) plus lactated ringers (LR) or RBC and LR with FFP. After resuscitation, bleeding was continued for 1 hour while intravenous replacement of RBC and LR with or without FFP was provided. Baseline, postshock, postresuscitation, post-1 hour exchange, postoperative day one and day two measurements included coagulation Factors I, II, V, VII, VIII, and X, and the prothrombin (PT), partial thromboplastin (PTT), and thrombin times (TT). Baseline, postshock, and postresuscitation hemodynamic responses, coagulation factor levels, and coagulation times were similar for both groups. By contrast, the 1-hour postexchange factors were depleted in the LR dogs compared to the FFP dogs. This depletion correlated with prolonged PT, PTT, and TT in the LR dogs (mean 14, 35, and 8 seconds) compared to FFP dogs (9, 24, and 6 seconds). Severe HS beyond one blood volume exceeds the interstitial stores of coagulation protein, thus necessitating FFP supplementation.
Journal of materials science. Materials in medicine, 2015
Type I, bovine skin collagen was allowed to gel in the presence of various concentrations of a ca... more Type I, bovine skin collagen was allowed to gel in the presence of various concentrations of a carbon nanotube material covered with a polystyrene/polyaniline copolymer, called a carbon nanobrush (CNB). The rate of collagen gelation was enhanced by the presence of the CNB in a dose dependent manner. The extent of collagen gelation was due to the concentration of collagen and not the amount of CNB. Collagen D-periodicity, and average fibril diameter were unchanged by the CNB material as seen in transmission electron micrographs. Gel tensile strength was reduced by the presence of the CNB in a dose related manner. The collagen-CNB mixture may have a role in the repair and reconstruction of wounds or degenerated connective tissue.
The theoretical efficacy of hypertonic saline (HS) resuscitation for hemorrhagic shock purportedl... more The theoretical efficacy of hypertonic saline (HS) resuscitation for hemorrhagic shock purportedly stems from the osmolar extraction of intracellular fluid into the plasma. This hypothesis presumes a concomitant expansion of the interstitial fluid space. Colloid resuscitation, in theory, expands the plasma volume by extracting interstitial fluid. These hypotheses were tested in a canine-modified Wigger's model of hemorrhagic shock. Forty, male, splenectomized dogs were anesthetized and instrumented. Animals underwent a baseline equilibration period followed by shock for 120 minutes. Each animal was randomized to one of four groups and received equal amounts of Na+ either as lactated Ringer's (LR) solution, 10% dextran 40 (Dex) in normal saline, 7.5% saline (HS), or 7.5% saline plus Dex (HSD). Parameters measured at baseline, shock, and at postresuscitation 30 minutes, 60 minutes, 90 minutes, and 120 minutes, included: mean pressure (MAP), output, pulmonary capillary wedge pr...
The Journal of Trauma: Injury, Infection, and Critical Care, 1995
Outcome-based therapy is becoming the standard for assessing patient care efficacy. This study ex... more Outcome-based therapy is becoming the standard for assessing patient care efficacy. This study examines the ability of an artificial neural network to predict rib fracture injury outcome based on 20 intake variables determined within 1 hour of admission. The data base contained 580 patient records with four outcome variables: Length of hospital stay (LOS), ICU days, Lived, and Died. A 522-patient training set and a 58-patient test set were randomly selected. Nine networks were set up in a feed-forward, back-propagating design with each trained under different initial conditions. These networks predicted the test set outcome variables with an accuracy as high as 98% at the 80% testing level. Internal weight matrix examination indicated that age, ventilatory support, and high trauma scores were strongly associated with both ICU days and mortality. Being female, injury severity, and injury type were associated with increased LOS. Smoking and rib fracture number were low-level predictors of the four outcome variables.
ABSTRACT Poloxamer gels have shown promise for repair and regeneration of tissues. Electrically c... more ABSTRACT Poloxamer gels have shown promise for repair and regeneration of tissues. Electrically conductive gels can be created by suspending carbon nanobrushes (CNB) in poloxamer gels. These biocompatible gels can support cell proliferation and have wound healing applications. The objective of this work is to optimize gels and mechanically characterize them using rheometry. Poloxamer gels were made using water and Dulbecco's Modified Eagle Medium (DMEM). Carbon nanobrushes were added in different concentrations. Temperature, frequency, and squeeze/pull-off tests were conducted on gels. Results indicate that the elastic and viscous properties of poloxamer gels change when carbon nanobrushes are added. Carbon nanobrushes impart conductivity, introduce nanostructure, and can be utilized to tune the macroscopic mechanical properties of poloxamer gels. Ongoing work will optimize poloxamer content and carbon nanobrush concentration for cell growth. This work is applicable for tissue engineering and regeneration in clinical medicine.
Biochemical and Biophysical Research Communications, 2012
Amino groups in proteins can non-enzymatically react with reducing sugars to generate a structura... more Amino groups in proteins can non-enzymatically react with reducing sugars to generate a structurally diverse group of compounds referred to as advanced glycation end products (AGEs). The in vivo formation of AGEs contributes to some of the complications of diabetes including atherosclerosis, cataract formation, and renal failure. The formation of AGEs is dependent on both sugar and protein concentrations. Increases in temperature, pH, and exposure time of sugars to the proteins also play a significant role in the rate of AGE formation. This study focuses on the use of a combination of analytical techniques to study the in vitro AGE formation of HSA with dihydroxyacetone phosphate (DHAP), a ketose generated during glycolysis, and its dephosphorylated analog, dihydroxy acetone (DHA), commonly used as a browning reagent in skin tanning preparations. The extent of AGE formation was affected by DHAP and DHA concentrations and by the duration of HSA exposure to these glycating agents. Increases in temperature and pH sped the glycation process and enhanced the formation of the AGEs of HSA. MALDI-TOF mass spectroscopic data provided a reliable result to evaluate the extent of the AGE formation.
Amino groups of human serum albumin (HSA) can react non-enzymatically with carbonyl groups of red... more Amino groups of human serum albumin (HSA) can react non-enzymatically with carbonyl groups of reducing sugars to form advanced glycation end products (AGEs). These AGEs contribute to many of the chronic complications of diabetes including atherosclerosis, cataract formation and renal failure. The current study focused on in vitro non-enzymatic reactivity of glyceraldehyde (GA) and methylglyoxal (MG) with HSA and evaluated the rate and extent of AGE formation in the presence of varied concentrations of Zn(II). At normal physiological conditions, GA and MG readily react with HSA. The presence of Zn(II) in HSA-GA or HSA-MG incubation mixtures reduced AGE formation. This finding was confirmed by UV and fluorescence spectrometry, HPLC techniques, and matrix assisted laser desorption ionization mass spectrometry (MALDI-TOF). HPLC studies revealed decreased adduct formation of the glycated protein in the presence of Zn(II). The inhibition of AGE formation was intense at elevated Zn(II) concentrations. The results of this study suggest that Zn(II) may prove to be a potent agent in reducing AGE formation.
Hemorrhagic shock (HS) often causes coagulopathy due, in part, to decreased coagulation proteins.... more Hemorrhagic shock (HS) often causes coagulopathy due, in part, to decreased coagulation proteins. This study assessed the efficacy of fresh frozen plasma (FFP) in preventing this coagulopathy following a canine model of HS designed to mimic bleeding with shock as seen in the emergency department followed by bleeding without shock as seen during operation for control of bleeding. Twenty-two dogs had acute HS for 2 hours followed by resuscitation with red blood cells (RBC) plus lactated ringers (LR) or RBC and LR with FFP. After resuscitation, bleeding was continued for 1 hour while intravenous replacement of RBC and LR with or without FFP was provided. Baseline, postshock, postresuscitation, post-1 hour exchange, postoperative day one and day two measurements included coagulation Factors I, II, V, VII, VIII, and X, and the prothrombin (PT), partial thromboplastin (PTT), and thrombin times (TT). Baseline, postshock, and postresuscitation hemodynamic responses, coagulation factor levels, and coagulation times were similar for both groups. By contrast, the 1-hour postexchange factors were depleted in the LR dogs compared to the FFP dogs. This depletion correlated with prolonged PT, PTT, and TT in the LR dogs (mean 14, 35, and 8 seconds) compared to FFP dogs (9, 24, and 6 seconds). Severe HS beyond one blood volume exceeds the interstitial stores of coagulation protein, thus necessitating FFP supplementation.
Journal of materials science. Materials in medicine, 2015
Type I, bovine skin collagen was allowed to gel in the presence of various concentrations of a ca... more Type I, bovine skin collagen was allowed to gel in the presence of various concentrations of a carbon nanotube material covered with a polystyrene/polyaniline copolymer, called a carbon nanobrush (CNB). The rate of collagen gelation was enhanced by the presence of the CNB in a dose dependent manner. The extent of collagen gelation was due to the concentration of collagen and not the amount of CNB. Collagen D-periodicity, and average fibril diameter were unchanged by the CNB material as seen in transmission electron micrographs. Gel tensile strength was reduced by the presence of the CNB in a dose related manner. The collagen-CNB mixture may have a role in the repair and reconstruction of wounds or degenerated connective tissue.
The theoretical efficacy of hypertonic saline (HS) resuscitation for hemorrhagic shock purportedl... more The theoretical efficacy of hypertonic saline (HS) resuscitation for hemorrhagic shock purportedly stems from the osmolar extraction of intracellular fluid into the plasma. This hypothesis presumes a concomitant expansion of the interstitial fluid space. Colloid resuscitation, in theory, expands the plasma volume by extracting interstitial fluid. These hypotheses were tested in a canine-modified Wigger's model of hemorrhagic shock. Forty, male, splenectomized dogs were anesthetized and instrumented. Animals underwent a baseline equilibration period followed by shock for 120 minutes. Each animal was randomized to one of four groups and received equal amounts of Na+ either as lactated Ringer's (LR) solution, 10% dextran 40 (Dex) in normal saline, 7.5% saline (HS), or 7.5% saline plus Dex (HSD). Parameters measured at baseline, shock, and at postresuscitation 30 minutes, 60 minutes, 90 minutes, and 120 minutes, included: mean pressure (MAP), output, pulmonary capillary wedge pr...
The Journal of Trauma: Injury, Infection, and Critical Care, 1995
Outcome-based therapy is becoming the standard for assessing patient care efficacy. This study ex... more Outcome-based therapy is becoming the standard for assessing patient care efficacy. This study examines the ability of an artificial neural network to predict rib fracture injury outcome based on 20 intake variables determined within 1 hour of admission. The data base contained 580 patient records with four outcome variables: Length of hospital stay (LOS), ICU days, Lived, and Died. A 522-patient training set and a 58-patient test set were randomly selected. Nine networks were set up in a feed-forward, back-propagating design with each trained under different initial conditions. These networks predicted the test set outcome variables with an accuracy as high as 98% at the 80% testing level. Internal weight matrix examination indicated that age, ventilatory support, and high trauma scores were strongly associated with both ICU days and mortality. Being female, injury severity, and injury type were associated with increased LOS. Smoking and rib fracture number were low-level predictors of the four outcome variables.
ABSTRACT Poloxamer gels have shown promise for repair and regeneration of tissues. Electrically c... more ABSTRACT Poloxamer gels have shown promise for repair and regeneration of tissues. Electrically conductive gels can be created by suspending carbon nanobrushes (CNB) in poloxamer gels. These biocompatible gels can support cell proliferation and have wound healing applications. The objective of this work is to optimize gels and mechanically characterize them using rheometry. Poloxamer gels were made using water and Dulbecco's Modified Eagle Medium (DMEM). Carbon nanobrushes were added in different concentrations. Temperature, frequency, and squeeze/pull-off tests were conducted on gels. Results indicate that the elastic and viscous properties of poloxamer gels change when carbon nanobrushes are added. Carbon nanobrushes impart conductivity, introduce nanostructure, and can be utilized to tune the macroscopic mechanical properties of poloxamer gels. Ongoing work will optimize poloxamer content and carbon nanobrush concentration for cell growth. This work is applicable for tissue engineering and regeneration in clinical medicine.
Biochemical and Biophysical Research Communications, 2012
Amino groups in proteins can non-enzymatically react with reducing sugars to generate a structura... more Amino groups in proteins can non-enzymatically react with reducing sugars to generate a structurally diverse group of compounds referred to as advanced glycation end products (AGEs). The in vivo formation of AGEs contributes to some of the complications of diabetes including atherosclerosis, cataract formation, and renal failure. The formation of AGEs is dependent on both sugar and protein concentrations. Increases in temperature, pH, and exposure time of sugars to the proteins also play a significant role in the rate of AGE formation. This study focuses on the use of a combination of analytical techniques to study the in vitro AGE formation of HSA with dihydroxyacetone phosphate (DHAP), a ketose generated during glycolysis, and its dephosphorylated analog, dihydroxy acetone (DHA), commonly used as a browning reagent in skin tanning preparations. The extent of AGE formation was affected by DHAP and DHA concentrations and by the duration of HSA exposure to these glycating agents. Increases in temperature and pH sped the glycation process and enhanced the formation of the AGEs of HSA. MALDI-TOF mass spectroscopic data provided a reliable result to evaluate the extent of the AGE formation.
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Papers by G. Dombi