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Biomedical subjects

J H Cissik

Publications and source records attributed to J H Cissik.

At least 19 recordsLinked to original sources
PubMed1993

Aggregation of killer whale platelets.

The aggregation of blood platelets is a crucial step in normal hemostasis for all mammals. Circulating platelets are sensitive to a large variety of physiologic and non-physiologic stimulants, some of which are formed or exposed in conjunction with vascular damage or endothelial cell denudation. In addition, drastic pressure changes activate human platelets. Killer whale platelet function, on the other hand, is very intriguing since these animals do not seem to experience untoward platelet reactions during or after diving to great depths, nor do they experience abnormal bleeding associated with sub optimal platelet function. We examined this concept and determined that killer whale platelets, in response to ADP, PAF, and arachidonic acid, appeared to aggregate normally during the first 2-5 minutes after addition of the agonist, but had completely disaggregated at 10 minutes. Collagen- and A23187-induced aggregation appeared normal and complete within 10 minutes, while there was no response to epinephrine or ristocetin. Thromboxane production by killer whale platelets appears to be quantitatively similar to that produced by human platelets in response to ADP and PAF and exceeded that produced by human platelets when collagen was used as the agonist. In summary, this study reports a reduced platelet aggregation reaction in killer whales in response to several platelet agonists which does not appear to be related to the generation of thromboxane. This phenomenon may serve a protective role in these mammals by preventing thrombosis during diving and resurfacing.

Adaptation, Physiological↗
PubMed1992

New extraction procedure and high-performance liquid chromatographic method for analyzing polyethylene glycol-400 in urine.

We describe a new, highly efficient method for extracting polyethylene glycol-400 from urine and for its analysis by isocratic reversed-phase high-performance liquid chromatography. This method is an improvement over previously published methods in that it does not require the use of ion-exchange resins and lyophilization prior to extraction, nor does it require the separation and analysis of the individual polymers of polyethylene glycol. The procedure described in this report entails extraction with a salt-solvent combination of ammonium sulfate and dichloromethane and analysis by reversed-phase high-performance liquid chromatography. The lower limit of detection was approximately 0.25 g/l with a 2-ml urine sample. Analytical recoveries of polyethylene glycol-400 added to urine at 2.5 and 5.0 g/l averaged 97 and 96%, respectively (n = 10). Within- and between-day coefficients of variation were less than 5% at 2.5 and 5.0 g/l. Studies of various urine samples from patients receiving polyethylene glycol-400 revealed no interferences from other urine substances.

Chromatography, High Pressure Liquid↗
PubMed1992

A comparison of human and porcine platelet fatty acid composition.

1. Human and pig platelets were analyzed for lipid composition by gas chromatography. 2. In comparing the two species' platelets, we noted significant differences in several lipid concentrations, some of which involved major lipid constituents. 3. The lipids for which there are significant differences in composition may contribute to those variations in platelet responses to stimulation demonstrated to exist between species.

Animals↗
PubMed1991

Cardiopulmonary reference standards in the pregnant sheep (Ovis aries): a comparative study of ovine and human physiology in obstetrics.

1. Complete blood counts, respiratory rate, tidal volume, arterial and mixed venous blood gases; heart rate, cardiac output, and arterial, pulmonary artery, central venous and pulmonary wedge pressures were determined in 10 pregnant adult sheep of 42.7-65.7 kg body weight. 2. Arithmetic means, standard deviations, and coefficients of variation were calculated to develop reference values; in addition, the 95% confidence limits for ranges were established. 3. Comparison of derived data with that from non-pregnant sheep shows changes similar to those seen when examining pregnant and non-pregnant humans. 4. These results indicate the pregnant sheep is an acceptable model for human obstetrical research.

Animals↗
PubMed1991

A comparison of human and canine platelet fatty acid composition.

1. Human and canine platelets were analysed for lipid composition by gas chromatography. 2. In comparing the two species' platelets, there were several lipids for which there were significant differences in lipid concentration. 3. The results indicate that human and canine platelets are quite similar in platelet lipid composition; however, the lipids for which there are significant differences may contribute to variations between species in platelet responses to stimulation.

Animals↗
PubMed1990

Cryogenically preserved adult and juvenile goat mandibular condylar transplantation.

Loss of a functional temporomandibular joint (TMJ) has long been a clinical challenge in both children and adults. Although reconstruction to date has been performed with various prosthetic devices or autogenous costochondral grafts, these procedures have a potential for complications and morbidity. Our studies were performed to determine the feasibility of healing, growth, and long-term function of TMJ reconstruction techniques with cryogenically preserved mandibular allografts in the goat model. This species was chosen because the surgical anatomy and biomechanics of the goat TMJ are very similar to those of the human TMJ. The positive results of the studies and their relevance will be described.

Animals↗
PubMed1990

Evaluation of Gore-Tex graft material in the repair of right ventricular outflow tract defect.

Following right ventriculotomy, Gore-Tex PTFE vascular grafts were placed in eight neutered male, 6- to 8-week-old, 8- to 12-kg pigs. Ten to 14 months after surgery each pig was evaluated by right heart catheterization. The swine were sacrificed and the hearts were evaluated grossly and microscopically. Comparison of the mean derived cardiovascular hemodynamic parameters in this group with published data on swine and humans indicated normal cardiovascular physiology. Since there was no gradient across the patched areas, it appears that the patches had no adverse effects on the cardiovascular system of growing pigs over an approximately 1-year time period. In addition, the Gore-Tex appeared to be satisfactory for the repair of right ventricular outflow enlargement. Its relative ease of handling, configuration, and lack of aneurysm formation were advantages over other available materials. However, focal calcification and chronic inflammatory reaction did indicate the possibility of long-term prosthetic failure.

Animals↗
PubMed1990

Simulated nasoalveolar palatal defects: a canine model to study bone grafts.

A simple, surgical technique to create a simulated nasoalveolar palatal defect in the canine is described. The procedure has been performed in 60 canines, and we have not experienced closure of the created clefts. The surgically created clefts had to fulfill five criteria: (1) bilateral maxillary alveolar clefts had to exist in each research animal; (2) each cleft had to have a 1-cm bony width; (3) a demonstrable oronasal communication had to be present; (4) each cleft had to be lined by healthy epithelialized mucosa; (5) there had to be functional teeth adjacent to each side of every cleft.

Animals↗
PubMed1989

Cardiovascular hemodynamics in the swine following long-term placement of prosthetic grafts post right ventriculotomy.

1. Heart rate, cardiac output and arterial, pulmonary artery, central venous and pulmonary wedge pressures were measured in eight neutered male pigs of an average of 14 months of age and 145.0-231.0 kg body weight. 2. These measurements were made 10-16 months after right ventriculotomy and placement of Gore-Tex PTFE Vascular Grafts. 3. Arithmetic means, standard deviations and coefficients of variation were calculated and the 95% confidence limits for ranges were established. 4. Comparison of derived data with that from published data on swine and on humans indicated normal cardiovascular hemodynamics in this group. 5. In addition, there was no gradient across the patched area. 6. It appears, therefore, that these patches had no adverse effects on the cardiovascular system of growing pigs.

Animals↗
PubMed1988

Effects of ritodrine hydrochloride on arteriovenous blood gas and shunt in healthy pregnant yellow baboons.

Although the cardiovascular, renal, and metabolic effects of ritodrine hydrochloride have been extensively investigated, its effect on shunt and oxygen dynamics have not. To define the effects of ritodrine hydrochloride on these parameters, six pregnant baboons were exposed to both low (1.5 micrograms/kg/min) and high (5 micrograms/kg/min) concentrations of the drug and compared with six control animals not exposed. Ritodrine had no effect on arterial or mixed venous oxygen tension, the arteriovenous oxygen content difference, or the venous-arterial shunt fraction. The treated animals did manifest a significant decline in both arterial (p less than 0.05) and mixed venous carbon dioxide (p less than 0.01) pressures, with associated increases in the respective pH values (p less than 0.001 and p less than 0.01). Total pulmonary resistance also showed a significant fall during ritodrine treatment (p less than 0.05). These data support a minimal, if any, impact of ritodrine hydrochloride on the blunting of normal hypoxic pulmonary vasoconstriction. Furthermore, these data are of potential use as a reference in the treatment of pregnant women who have sustained life-threatening insults from exposure to these agents.

Animals↗
PubMed1988

Transplantation of cryogenically preserved mandibular condyles in the adult and juvenile goat.

Loss of a functional temporomandibular joint (TMJ), due to various causes including tumor resection, joint disease such as osteonecrosis, and injury or trauma, has long been a clinical challenge in both children and adults. It may be a significant problem facing physicians during another war. While reconstruction to date has been performed with various prosthetic devices or autogenous costochondral grafts, these procedures have a potential for complications and morbidity. This procedure could adversely delay the return of military members to a combat unit, or affect their ability to serve as functional members of society. Our studies were performed to determine the feasibility of TMJ reconstruction techniques, healing, and long-term function and growth using cryogenically preserved mandibular allografts in the goat. This species was chosen because the surgical anatomy and biomechanics of the goat TMJ are very similar to that of the human. The positive results of the studies and their relevance to future military medical readiness and civilian medicine will be described.

Age Factors↗
PubMed1987

Reference standards and the physiologic significance of the pregnant goat (Capra hircus) as a human model in obstetrical research.

1. Amniotic fluid, cerebrospinal fluid, serum, and urine chemistries; respiratory rate and arterial and mixed venous blood gases; heart rate, hematocrit, and cardiac output; and arterial, pulmonary artery, central venous and pulmonary wedge pressures were measured in 20 pregnant adult goats of 19.5-34 kg body weight. 2. Arithmetic means, standard deviations, and coefficients of variation were calculated to develop reference values; in addition, the 95% confidence limits for ranges were established. 3. Comparison of derived data with that from non-pregnant goats shows changes similar to those seen when examining pregnant and non-pregnant humans. 4. These results indicate the pregnant goat is an acceptable model for human obstetrical research.

Animals↗
PubMed1987

Determination of cardiac output and other reference physiology parameters in lightly anesthetized dogs.

1. Cardiac output; arterial, pulmonary artery, central venous and pulmonary wedge pressures; heart rate, hematocrit, and plasma sodium and potassium; arterial and mixed venous blood gases; and respiratory rates were measured in 45 mixed sex, non-pregnant, clinically normal mongrel dogs of 8-30 kilograms body weight following light anesthesia with halothane/50% N20-02. 2. Arithmetic means and standard deviations were calculated to develop tables of reference values. 3. Mean measured cardiac outputs were found to be 31-59% higher in these dogs than the values indicated by published standards; cardiac indices were 30-44% higher; heart rates were 16-30% lower; calculated stroke volumes were 60-112% greater; and total peripheral resistances were 35-57% less than the standard published values. 4. All other measured or calculated parameters fell within previously published canine or human reference limits.

Anesthesia, General↗
PubMed1987

Clinically stable asthmatics have highly reproducible pulmonary function tests.

The reproducibility of standard function tests was evaluated in a group of ten stable asthmatics over a 10-day period. Relationships between repeated measures of pulmonary functions examined by analysis of variance at the 95% confidence level were comparable to studies in normal subjects. This precision helps validate the recommendations of the Committee on Emphysema for assessment of reversibility in airway obstruction.

Adult↗
PubMed1986

Double-blind crossover study of five bronchodilator medications and two delivery methods in stable asthma. Is there a best combination for use in the pulmonary laboratory?

The effects of five bronchodilator drugs and two methods of delivery (nebulizer vs metered-dose inhalers) on pulmonary function were studied in ten subjects with stable asthma. All subjects demonstrated statistically significant improvements (p less than 0.05) in pulmonary function relative to baseline and placebo effects after each medication, regardless of method of delivery; however, there was no statistically significant difference between the changes in pulmonary function caused by medication, method, or medication-method combination (p greater than 0.05). The choice of medication and device for delivery would appear to depend on the budget and time available in the laboratory.

Administration, Inhalation↗
PubMed1982

Effects of cigarette smoking on pulmonary function in asymptomatic asbestos workers with normal chest radiograms.

A comprehensive health screening program consisting of standardized health and occupational history questionnaire, blood chemistry profile, complete blood count, urinalysis, chest radiograph, and pulmonary function testing was organized for the Asbestos Workers Union Local Number 1 in St. Louis, Missouri. The program was available on a voluntary basis to all the workers in the Union. One hundred and thirty-five male caucasian workers or 44% of the membership volunteered to participate and all the data were used in this study. All blood chemistry profiles and urinalysis results were within normal limits. Twenty-two of the asbestos workers had radiologic pulmonary abnormalities as well as severe pulmonary function impairment. The remaining 113 workers were divided into subgroups based on the number of years of exposure to asbestos and their smoking history. Although asymptomatic, workers with more than 20 years exposure to asbestos had significantly decreased pulmonary functions compared to those with less than 20 years exposure. When smokers and nonsmokers were compared, an additive effect between smoking and asbestosis was observed. This study also discovered that significant decreases in pulmonary functions occur early in the exposure to asbestos.

Adult↗
PubMed1981

Evaluation of the Cavitron Spirometric Computer for accuracy in clinical screening spirometry.

Ten healthy male cardiopulmonary technicians, 10 aircrew members, and 10 patients performed a series of pulmonary function studies to compare the Cavitron Spirometric Computer to the conventional water-sealed Collins 13.5-/spirometer. A total of 50 studies were performed on the spirometers individually and then with the spirometers linked in-line. The Cavitron FVC averaged 6% less, the FEV1--7% less, and the FEF 25-75%--11.6% less than comparable measurements from the Collins spirometer. Since these difference are within the suggested guidelines for screening studies, the Cavitron Spirometric Computer is acceptable for use in clinical screening spirometry.

Adult↗