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Biomedical subjects

H Illner

Publications and source records attributed to H Illner.

At least 19 recordsLinked to original sources
PubMed1999

The effect of sympatholytics on uncontrolled hemorrhage.

OBJECTIVE: To assess the possible benefits of sympatholytics on uncontrolled hemorrhage in unanesthetized rats. DESIGN: A randomized laboratory study using rats to test the effects of sympatholytics on uncontrolled hemorrhage. SETTING: Research laboratory. SUBJECTS: Forty female Sprague-Dawley rats, randomly assigned into four groups according to the treatment: untreated (Control); alpha-adrenergic blockade with phenoxybenzamine (Alpha); beta-adrenergic blockade with propranolol (Beta); and a combined alpha- and beta-adrenergic blockade by phenoxybenzamine and propranolol (Alpha/Beta). INTERVENTION: After cannulation under light ether, the rats were allowed to awaken. A baseline blood sample was withdrawn. The uncontrolled hemorrhage was initiated by tail resection and allowed to continue without intervention for the duration of the experiment. After 15 mins, 80 mL/kg isotonic saline fluid was infused at 4.4 mL/min. At 60 mins, another blood sample was drawn; changes in mean arterial pressure, hematocrit, blood loss, and mortality were observed for up to 180 mins. MAIN OUTCOME MEASURE: Survival, mortality, blood loss (amount, prevalence, and rate), and hemodynamic variables (mean arterial pressure, pulse rate, hematocrit). RESULTS: In the Alpha group, there was a reduction in spontaneous blood loss compared with the control group (2.9 vs. 10.6 mL/kg, respectively) and 100% survival. In contrast, the Beta group exhibited an increase in tail blood loss (21.1 mL) and a decreased survival (10%). Despite the enhanced hemorrhage in the Alpha/Beta group (17.0 mL/kg) compared with controls, the survival rate in both of these groups was 60%. In all groups, no significant increase in tail blood loss was observed after 60 mins. CONCLUSIONS: An alpha-adrenergic blockade increased survival in uncontrolled hemorrhage by significantly reducing spontaneous blood loss. Conversely, a beta-adrenergic blockade significantly decreased survival and increased blood loss, whereas a combined blockade significantly increased blood loss without affecting survival.

Adrenergic alpha-Antagonists↗
PubMed1999

The effects of varying fluid volume and rate of resuscitation during uncontrolled hemorrhage.

BACKGROUND: The role of rate and volume of infusion in survival from experimental uncontrolled hemorrhage was evaluated. METHODS: Hemorrhage was initiated using tail resection in 43 female rats assigned to the following five groups: nonresuscitated; resuscitated with moderate volume, slower rate; resuscitated with moderate volume, faster rate; resuscitated with high volume, slower rate; and resuscitated with high volume, faster rate. RESULTS: A trend toward improved survival was noted with faster rate of infusion (60 vs. 33.3% survival rate with moderate volume and 28.6 vs. 12.5% with high volume, compared with 16.7% in the nonresuscitated animals). CONCLUSION: Rapid infusion of moderate volume of isotonic saline improved survival in uncontrolled hemorrhage. Extreme volumes, infused rapidly, also resulted in higher survival rates compared with those observed in nonresuscitated rats.

Animals↗
PubMed1995

Effects of anesthesia on a model of uncontrolled hemorrhage in rats.

OBJECTIVES: Excessive blood loss in a rat model of uncontrolled hemorrhage has been attributed to the vasodilatory effects of a droperidol-ketamine mixture used for anesthesia. The present study compared responses to droperidol-ketamine and pentobarbital with those responses of a control group without anesthesia during uncontrolled hemorrhage. DESIGN: Prospective, randomized, controlled trial. SETTING: University surgical research laboratory. SUBJECTS: Forty-five female Sprague-Dawley rats (210 to 275 g). INTERVENTIONS: Rats were randomly divided into three groups of 15 each according to the type of anesthesia: unanesthetized; pentobarbital; and droperidol-ketamine. A 75% tail resection was used to initiate hemorrhage. Mortality, survival time, and blood loss were monitored, and the differences between all three groups were tested using chi 2 test (mortality) and one-way analysis of variance (ANOVA) (survival and blood loss) for statistical significance. MEASUREMENTS AND RESULTS: Mean blood loss amounts at 15 mins were 8.9, 13.6, and 22.4 mL/kg for the unanesthetized, pentobarbital, and droperidol-ketamine groups, respectively. Mortality rates for the three groups were 0%, 0%, and 53% at 30 mins and 60%, 33%, and 93% at 90 mins, respectively. Mean survival times for these groups were 94, 135, and 39 mins, respectively. CONCLUSIONS: An excessive rate of blood loss due to the use of droperidol-ketamine anesthesia renders this model inappropriate for investigation of uncontrolled hemorrhage. The response of rats under pentobarbital anesthesia more closely approximates that of unanesthetized rats. However, the higher mortality rate despite the lesser hemorrhage observed in the latter group seems to indicate the existence of other factors (in addition to blood loss) that may contribute to the early death of these animals.

Analysis of Variance↗
PubMed1993

The regulation of intracellular Mg2+ in guinea-pig heart, studied with Mg(2+)-selective microelectrodes and fluorochromes.

Because of the reported presence of a Na(+)-Mg2+ exchanger in guinea-pig but not in ferret myocardium, the Mg2+ extrusion mechanism in guinea-pig myocardium has been reinvestigated using Mg(2+)- and Na(+)- selective microelectrodes and the fluorochromes mag-fura-2 and -5. The mean [Mg2+]i measured with microelectrodes in trabeculae or papillary muscles was 0.72 mmol/l (n = 22, thirteen experiments; range 0.42-1.23 mmol/l). Increasing [Mg2+]o from 0.5 mmol/l to either 10.5 or 20 mmol/l caused small increases in [Mg2+]i. Decreasing [Na+]o by 50% had no effect on the [Mg2+]i and there was no change in [Na+]i on increasing [Mg2+]o from 0.5 to 10.5 mmol/l. Varying pHo or changing pHi with NH4Cl did not influence the [Mg2+]i. In vitro calibration of mag-fura-2 and -5 using the ratio method gave values for K'd (experimentally determined dissociation constant) of 22.2 +/- 2.7 (mean +/- S.D., n = 7) and 25.7 +/- 1.3 (n = 4) mmol/l respectively. Mag-fura-2 reacted to physiological concentrations of Ca2+ and mag-fura-5 to changes in pH. In isolated myocytes, Na+ removal gave an apparent increase of [Mg2+]i with mag-fura-2 but not with mag-fura-5. However, when the pHi was altered with NH4Cl mag-fura-5 showed an apparent decrease in [Mg2+]i on application and an apparent increase on removal, with a time course similar to the pHi changes. It is concluded that Mg2+ extrusion in guinea-pig myocardium is not via a Na(+)-Mg2+ exchanger. The use of mag-fura-2 and -5 are limited in their application because of Ca2+ and H+ sensitivity respectively.

Animals↗
PubMed1993

The effects of isotonic saline volume resuscitation in uncontrolled hemorrhage.

In the present study, the effects of early isotonic fluid resuscitation on uncontrolled hemorrhage in rats under pentobarbital anesthesia were assessed. Forty-five female Sprague-Dawley rats, weighing between 230 and 295 grams, were anesthetized and cannulated. Uncontrolled hemorrhage was initiated by a 75 percent tail resection, and the rats were randomly divided into three groups: group 1, no resuscitation; groups 2 and 3, saline solution administration over a four minute interval (40 and 80 milliliters per kilogram, respectively), 15 minutes after the initial hemorrhage. Changes in blood pressure, blood loss and mortality rates were recorded and the rats were observed for up to 360 minutes. The mortality rates were 73, 40 and 53 percent for groups 1, 2 and 3, respectively. The corresponding average survival times for these groups were 135, 195 and 178 minutes. The difference between groups 1 and 2 were above the 95 percent confidence level using the chi-square test (mortality) and the Student's t test. The average total blood loss in groups 2 and 3 was 31.7 and 41.4 milliliters per kilogram of body weight; when compared with group 1 (24.6 milliliters per kilogram), the difference between the two latter groups (1 and 3) was statistically significant with a p < 0.001. These results suggest that early infusion of isotonic fluid improves survival time and reduces short term mortality in uncontrolled hemorrhage regardless of the associated increases in blood loss.

Animals↗
PubMed1992

Evaluation of mag-fura-5, the new fluorescent indicator for free magnesium measurements.

The new fluorescent indicator, mag-fura-5, was evaluated for its ability to measure accurately physiological changes in cytosolic free magnesium. The apparent dissociation constants (Kd) of the fluorochrome for Mg2+, Mg2+/EGTA and Ca2+/EGTA solutions were 14.7 mM, 15.4 mM, and 1.8 mM respectively. The calculated difference in the fluorescence ratios and in the resulting pMg between the standards with low-Ca2+ or low H+ backgrounds and the corresponding samples with approximately physiological levels were not significant. In contrast, the changes due to an increased Ca2+ or H+ content were statistically significant, with mean pMg differences of 0.10 +/- 0.09 (P < 0.02) and 0.33 +/- 0.26 (P < 0.01) respectively. Repetitive measurements on 3 consecutive days yielded comparable data with differences not exceeding 4%. Because of the good reproducibility, it is suggested that the new fluorescent probe may be suitable for free cytosolic magnesium determinations in isolated cells.

Calcium↗
PubMed1989

Use of topical antiseptic in prophylaxis of catheter-related septic complications.

Pretreatment of catheters by a simple new procedure designed to reduce the incidence of septic complications was tested in both in vitro and in vivo studies. In the former experiments, the high sensitivity of gram-negative bacteria and fungi to Silastic (silicone rubber) catheters pretreated with silver nitrate solution was determined. The antimicrobrial activity remained unchanged after both sterilization and up to six weeks of storage. Furthermore, prolonged incubation of treated catheter segments in Escherichia coli inoculated plasma resulted in a significant reduction of organisms in the media and those adherent to the surface of the catheters. The in vivo experiments were performed upon two groups of rabbits. In the first group, catheters (one treated and one untreated) were implanted into contralateral jugular veins. In the second group, alternating treated and control catheter segments were threaded onto polyethylene core tubing; the resulting string of segments was positioned in the inferior vena cava. Five to 11 days after implantation of the catheter, all rabbits were intravenously injected with live E. coli (approximately 10(8) to 10(9) organisms per kilogram of weight); 18 to 24 hours later, the catheters and blood samples were removed for cultivation. Significant reductions in both incidence and magnitude of colonization in treated catheters by E. coli were observed in both rabbit groups. Additionally, histologic examination did not reveal any significant differences between contralateral jugular veins (previously in prolonged and intimate contact with the indwelling catheters), confirming the absence of any local adverse effects of silver nitrate.

Animals↗
PubMed1985

Extracellular fluid deficit following operation and its correction with Ringer's lactate. A reassessment.

The changes in extracellular fluid volume (ECV) in two groups of surgical patients, one receiving Ringer's lactate solution intraoperatively and the other receiving only dextrose and water, were assessed. A deficit in the ECV, as measured by radioactive sulfate, of 1.9 +/- 0.8 l (p less than 0.003) compared to the preoperative volume was found in the dextrose group. This was accompanied by a decrease in the mean creatinine clearance (-13% p less than 0.01), the mean urinary sodium excretion (-57% p less than 0.05), and the mean rate of clearance of the sulfate tracer (-18% p less than 0.01). The use of intraoperative Ringer's lactate (1660 cc +/- 96 cc) resulted in no change in the ECV, an increase in the mean creatinine clearance (+10% p less than 0.05), and no change in sodium excretion or tracer clearance. As a result of these findings, it appears that postoperative sodium retention is a physiologic response to a decreased ECV, which can be prevented by the administration of Ringer's lactate.

Adult↗
PubMed1985

Cellular function in liver and muscle during hemorrhagic shock in primates.

The results of this study demonstrated that muscle ATP levels were sustained in hemorrhagic shock despite marked deterioration of muscle function as indicated by a decline in PD. This indicated that energy depletion was not the primary basis of the cellular dysfunction in hemorrhagic shock. Cellular dysfunction and metabolic abnormalities in the liver occurred earlier during the course of hemorrhagic shock than in muscle. Other studies were cited in which it was suggested that inhibition of the membrane bound sodium and potassium active transport mechanism is the likely cause of tissue electrolyte and fluid shifts observed during prolonged periods of hemorrhagic shock.

Adenosine Triphosphate↗
PubMed1984

Increased chromium uptake in polymorphonuclear leukocytes from burned patients.

Following thermal injury neutrophil function is severely impaired and thought to be hypometabolic; however, the host is considered to be hypermetabolic. To further investigate the metabolism and the function of neutrophils following thermal injury, neutrophil migration and chromium uptake were studied using radio-labelled neutrophils. Random and directed migration were found to be significantly reduced compared to control values. Neutrophil lysozyme content was also reduced in these burn cells while serum lysozyme from the same patients was significantly elevated over control values. These data suggest lysozyme is released by the neutrophil into the circulatory system. The influx of chromium in cells from burned patients was much greater than the influx in normal cells used in studies for chemotaxis. Influx of chromium over time and over varying concentrations of chromium was linear (r2 = 0.90) in cells from burned patients and normals. Cells from burned patients, however, took up more chromium than normals. Influx velocity of chromium was also determined and found to be greater in burn cells than normal cells. Since it has been shown that chromium influx is an energy-dependent reaction it is suggested that cellular energy stores are being depleted by the influx of chromium. Whether this is a response to an intracellular deficit or uncoupling of metabolic pathways is not known at this time.

Adult↗
PubMed1983

Response of extravascular lung water to intraoperative fluids.

The effect of Ringer's Lactate (RL) and a colloid containing salt solution Plasmanate (PL) on extravascular lung water (EVLW) during aortic surgery was evaluated in a prospective study of 18 patients. Measured blood loss was replaced with packed red blood cells. In addition to red blood cell replacement, either RL or PL was infused (1) to maintain the cardiac output (CO) equal to or greater than the preoperative value, (2) to maintain the pulmonary capillary wedge pressure (PCWP) plus or minus 2 mmHg of preoperative values, and (3) to keep the urinary output greater than or equal to 30 cc/hr. Cardiac output, EVLW, PCWP, serum colloid osmotic pressure (COP), and intrapulmonary shunt fraction (Qs/Qt) were measured serially. All baseline values were similar between groups. The groups were well matched for age, associated disease, operating time, blood loss, and blood transfusions. During operation, the RL group required two times the rate of infusion of the PL group. Urine flow rates were similar on the day of surgery, but by postoperative days one and two, the PL group had approximately one-half of the urine flow rate compared to the RL group. Cardiac output and Qs/Qt increased in both groups. EVLW did not change after operation in either group, despite marked decrease in COP in the RL group. These data indicate that crystalloid resuscitation to physiologic endpoints does not increase extravascular lung water. Thus, manipulation of COP by PL was unnecessary in these patients.

Aged↗
PubMed1983

Changes in red blood cell transmembrane potential, electrolytes, and energy content in septic shock.

Septic shock was induced in adult baboons by the infusion of live Escherichia coli. A progressive derangement in skeletal muscle cell function was documented by the direct measurement of declining transmembrane potential difference (PD). A concurrent depolarization of the red blood cell (RBC) was characterized by cellular uptake of chloride, sodium, and water, and loss of potassium. The decrease in RBC PD was significantly greater than the change predicted to occur from acidosis alone. These findings are compatible with changes in membrane permeability and decreased active transport. The continuous accumulation of RBC adenosine triphosphate during shock suggests decreased energy utilization rather than decreased energy production as a factor leading to diminished active ion transport.

Animals↗
PubMed1983

Hepatocyte dysfunction in thermal injury.

Transmembrane potential difference (PD) is a reliable indicator of cellular function. Decreased PD in hepatocytes in hemorrhagic shock occurred concomitant with decreased adenosine triphosphate (ATP), suggesting energy depletion as the mechanism of cell dysfunction. This study correlates changes in liver and muscle PD with hepatocyte ATP, glucose-6-phosphate (G-6-P), and lactate levels in burn shock and resuscitation. Six adult female baboons were subjected to 52.4 +/- 6.3% body surface area third-degree scald burns. The animals were resuscitated using the Parkland formula, after the muscle PD had fallen to -70 mV. Liver PD decreased from 46.2 +/- 2.4 mV to 22.4 +/- 3.8 mV in burn shock. The PD recovered toward normal with resuscitation. ATP and G-6-P contents did not change significantly, while lactate rose threefold in burn shock. A severe cellular derangement was indicated by this marked hepatocyte depolarization. Maintenance of normal intracellular ATP excludes energy depletion as the mechanism of this cell dysfunction. These findings are consistent with failure of active ion transport or changes in cell membrane permeability which were partially recovered during fluid resuscitation.

Adenosine Triphosphate↗
PubMed1983

Neutrophil migratory activity in severe hemorrhagic shock.

Sepsis continues to be a major cause of patient death following hemorrhagic shock. To explain this increased susceptibility to infection on a cellular level, neutrophil function was studied in nine adult baboons subjected to severe hemorrhage. Neutrophil migratory activity was found to be significantly decreased immediately after hemorrhage (P less than 0.05 vs control) and continued to decline throughout the experiment. After an initial small decline, neutrophil adherence increased to significant levels after 4 h of hypotension (P less than 0.05 vs control). The present data support the hypothesis that increased susceptibility to infection after sustained hemorrhage is a result of impaired neutrophil function.

Animals↗
PubMed1982

Pulmonary acid injury: effects of positive end-expiratory pressure and crystalloid vs colloid fluid resuscitation.

Pulmonary acid aspiration results in hypoxemia and hypovolemia. We assessed the effects of positive end-expiratory pressure (PEEP) and fluid resuscitation on oxygenation and alveolar-capillary membrane permeability after acid aspiration. Alveolar-capillary membrane permeability was assessed by determination of extravascular lung water volume, using the thermal-green dye double-indicator technique, extravasation of iodinated 1 125 serum albumin into lung parenchyma, and albumin leak into the alveolar spaces. The data from this study demonstrated that PEEP improved oxygenation after acid aspiration, but did not alter progression of the injury; cardiac output and oxygen transport were improved by plasma volume repletion while receiving PEEP; and resuscitation with 5% albumin solution increased plasma albumin content and tracheal albumin content commensurately and did not modify progression of the injury.

Animals↗
PubMed1982

The effect of intravenous steroids on alveolar-capillary membrane permeability in pulmonary acid injury.

The treatment of pulmonary aspiration of gastric contents remains largely empirical. The purpose of the present study was to evaluate the effect of methylprednisolone administration (30 mg/kg) on alveolar-capillary membrane permeability after pulmonary acid aspiration in dogs. Alveolar-capillary membrane permeability was assessed by several methods. Extravascular lung water volume (EVLW), extravasation of 125I-serum albumin (RISA) into lung parenchyma, and albumin leak into the alveolar spaces were measured. EVLW increased progressively from 5.5 +/- 0.6 to 20.0 +/- 2.3 ml/kg in Group I (Acid) and from 5.4 +/- 1.2 to 22.1 +/- 3.1 ml/kg in Group II (Acid + Steroids) over the 5 hours after acid injury. The ratio of Lung Extravascular RISA to Plasma RISA was 0.56 +/- 0.14 and 0.58 +/- 0.14 in Group I and Group II, respectively (normal = 0.19 +/- 0.06). The tracheal albumin to plasma albumin ratio remained near 1.0 from 2 hours to 5 hours post-aspiration in both groups. This study demonstrated that pulmonary acid injury resulted in a marked increase in alveolar-capillary permeability to albumin, smaller solutes, and water which was not ameliorated by the administration of methylprednisolone.

Adrenal Cortex Hormones↗
PubMed1982

Changes in sodium, potassium, and adenosine triphosphate contents of red blood cells in sepsis and septic shock.

Sepsis and septic shock were induced in fifteen awake rabbits by the infusion of live Escherichia coli. Sodium K+, and adenosine triphosphate (ATP) concentrations in red blood cells (RBC) and plasma were measured during the control, septic, and septic shock periods. The significant elevations of Na+ content in RBC during sepsis appeared to be primarily a function of increased cell membrane permeability. The significantly decreased intracellular K+ concentrations, accompanying the high Na+ levels of RBC later in shock, were consistent with progressive failure of the energy-dependent transport mechanism (Na+-k+ pump). Hyponatremia and hyperkalemia were apparent in the late stages of sepsis, these alterations reached statistically significant levels in the shock period. The electrolyte derangements associated with sepsis and septic shock could not be related to energy depletion. The continuous significant accumulations of ATP, observed in RBC and plasma, were interpreted as a result of decreased energy utilization and attributed to the diminished active ion transport by the impaired Na+-K+ pump.

Adenosine Triphosphate↗