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Biomedical subjects

J C Rice

Publications and source records attributed to J C Rice.

At least 19 recordsLinked to original sources
PubMed1992

Structural requirements for galanin inhibition of pentagastrin-stimulated gastric acid secretion in conscious rats.

The effects of rat galanin, together with a number of its N- and C-terminal fragments, on pentagastrin-stimulated gastric acid secretion were studied in conscious rats equipped with chronic gastric fistulas. Similarly to its porcine counterpart studied previously, at a dose of 3 nmol/kg per h rat galanin was a potent inhibitor of gastric acid secretion. The N-terminal fragments, rat galanin-(1-10) and -(1-15), retained about 60% of the inhibitory potency of the whole galanin sequence whilst the C-terminal fragments, rat galanin-(2-29), -(3-29) and -(9-29), were unable to produce significant inhibition over comparable dose ranges. Surprisingly, however, simply acetylating the alpha-amino group in position 9 of rat galanin-(9-29) restored almost full gastric acid inhibitory activity in a homologous rat model. We speculate that this could be due to a favorable conformational effect on the C-terminal region produced by alpha-acetylation. These results also suggest that structural features within either the N-terminal or C-terminal regions of rat galanin are able to elicit this particular biological response. One possible explanation for this could be the involvement of more than one rat galanin receptor having different ligand recognition requirements.

Animals↗
PubMed1992

The effect of sex education on teenagers in St. Kitts and Nevis.

Knowledge of sexual matters is one of several key factors capable of influencing teenage reproductive behavior. This article reports the results of initial and followup surveys designed to test such knowledge among adolescent students in St. Kitts and Nevis before and after they received a family life/sex education course in the mid-1980s. This course provided information about fundamentals of human reproduction and contraception, human growth and development, emotional development, and issues of adolescent sexuality.

Adolescent↗
PubMed1991

Infrainguinal revascularization for limb salvage in patients with end-stage renal disease.

We studied the efficacy of infrainguinal bypass for limb salvage in patients with end-stage renal disease. The patency of 42 femoropopliteal and femorodistal bypasses, performed for limb salvage in 37 patients with end-stage renal disease, was assessed with Doppler ultrasonography and dye tests. Patency rates and limb salvage were determined by life-table analysis. Average age was 45 years (range, 28 to 61 years); 23 of the 37 were men. Twenty-three patients had diabetes mellitus, and 16 were smokers. Bypass procedures were done in 32 instances while the patients were maintained with chronic hemodialysis and in five instances with peritoneal dialysis; in five instances the patients had had successful renal transplantation. Indications for revascularization included pain at rest, nonhealing ulcer, or distal gangrene. Femoropopliteal bypass was done in 32 limbs; 10 were more distal procedures. Reversed saphenous vein was the conduit in 30 cases; prosthetic material was used in the remainder. Autogenous material was used in all distal bypasses. Four patients required graft revision during the initial hospitalization, but none thereafter. Two patients died within the operative period, nine within 18 months of operation. Nine major operations were required. Three-month cumulative graft patency was achieved in 41 cases and corresponding limb salvage in 33 cases; 18-month patency was achieved in 34 cases and overall limb salvage in 33 cases. Success of limb salvage most closely correlated with preoperative ankle-brachial ratio and level of bypass required.

Adult↗
PubMed1991

Distribution and elimination of [2-14C]amino-3,8-dimethylimidazo [4, 5-f] quinoxaline in mice. Analysis by whole animal autoradiography.

1. 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) is a potent bacterial promutagen and carcinogen, formed when beef is cooked. In mammals, MeIQx is metabolized and activated by liver enzymes, but induces tumours in both hepatic and extrahepatic tissues. 2. Intravenous administration of [14C]MeIQx and whole animal autoradiography has been employed to examine the disposition of MeIQx. Within 10 min, radiolabel was distributed throughout body tissue. Liver levels of radioactivity rapidly rose and remained elevated in comparison to other tissues, throughout the period of study (4 d). 3. At early time points radioactivity accumulated in the stomach, kidney and salivary glands then later in the intestine. Radioactivity was rapidly eliminated from the majority of tissues although did persist in liver and intestines throughout the duration of the study, probably due to covalently bound material. No radioactivity could be detected in the central nervous system, thus neither MeIQx nor its metabolites cross the blood-brain barrier to any significant extent. 4. The rapid elimination of radioactivity from the tissues is in good agreement with the time course of excretion of MeIQx. Irrespective of the route of administration (i.v., i.p., p.o.), a substantial proportion of the labelled material is excreted within 24 h and is present in both urine and faeces in similar quantities. 5. Thus MeIQx is extensively bioavailable, is distributed throughout body tissue and, although the majority is quickly cleared, some remains bound to liver and intestine.

Animals↗
PubMed1990

The fabric dependence of the orthotropic elastic constants of cancellous bone.

It has been proposed that the orthotropic elastic constants of cancellous bone depend upon a tensorial measure of anisotropy called fabric as well as the tissue's structural density. Cowin (1985, Mechanics Mater, 4, 137-147; 1986, J. biomech. Engng 108, 83-88) developed explicit relationships for the elastic constant, structural density and fabric relationship. In this study the orthotropic elastic moduli, structural density, and fabric components were measured for 11 cancellous bone specimens from five bovine femora and for 75 specimens from three human proximal tibiae and fitted to these relationships using a least squares analysis. The relationships explained between 72 and 94% of the variance in the elastic constants. The relationships between the elastic constants and squared or cubed power functions of structural density had better predictive value over the entire distribution of the data than did expressions with linear functions of structural density.

Aged↗
PubMed1990

Efficacy of home health care in patients with peripheral vascular disease.

This investigation was designed to study the effects of home health care (HHC) on patients who have been hospitalized with peripheral vascular disease. For a patient to have HHC, the patient had to have a defined wound, educational needs, or both. Sixty patients, 30 with HHC and 30 without, were contacted approximately 30 days after their last hospital discharge. The 30 patients with HHC were deemed to be at increased risk because of multisystem disease with multiple medications, infirmity, early senility, and often complex wounds. In a prospective fashion, each patient was interviewed by either a registered nurse or medical student using a standardized data collection form. The following issues were assessed: incidence of postoperative complications, knowledge of the patient of his or her disease, compliance with medication (knowledge of, regular use), incidence of readmission, and unscheduled clinic or emergency department visits. Upon statistical analysis using the two-sample t-test and Pearson chi-square test, no significant differences were found between the two groups in terms of complications, compliance, or patient education. HHC, therefore, was found to be helpful to patients with peripheral vascular disease. In our study, the use of HHC made the risk of complications in a group of patients with defined teaching needs and wound care needs equal to that in a group with no such defined needs on discharge from the hospital.

Chi-Square Distribution↗
PubMed1990

Factors important to students in selecting a residency program.

A 22-item questionnaire, designed to assess the factors students considered important when they ranked residency programs, was distributed to the 1988 senior class of Tulane University School of Medicine just before the submission deadline of the National Residency Matching Program. Completed surveys were obtained from 111 of the 157 graduating students (approximately 71%) and were representative of the entire class in terms of sex, age, race, marital status, and anticipated field of specialization. Results of this investigation suggest that the satisfaction of a program's house officers and the seniors' general impression at the interview were the most important selection factors of the matriculating seniors surveyed. Diversity of the training experience and geographic location were also important selection factors. House officer benefits and salary were low-priority factors in the seniors' program selections.

Career Choice↗
PubMed1990

Asymmetries of sleep spindles and beta activity in pediatric EEG.

Unilateral suppression of beta activity, unilateral suppression of sleep spindles, and unilateral delta slowing on EEG have not been previously compared regarding accompanying neuroradiological (NR) and clinical neurological (CN) findings in children. We studied EEGs in children under age 10 years with unilateral beta suppression (n = 80), spindle suppression (n = 51) or unilateral delta slowing (n = 49). There were no significant differences between the three groups of abnormal EEGs in their relationships with NR and CN. Unilateral suppression of sleep spindles and beta activity are at least as accurate as focal slowing in lateralizing NR and CN findings.

Beta Rhythm↗
PubMed1990

Patient compliance with fitted compression hosiery monitored by photoplethysmography.

This study assessed the compliance useage and impact by monitoring of graded compression hosiery in chronic venous disease. Diagnostic methods, such as qualitative photoplethysmography (PPG), have enabled the physician to assess deep-vein valvular incompetence earlier and begin specific treatment measures to slow the progression of symptoms. This study group, comprised of 100 patients, was diagnosed initially with deep-venous thrombophlebitis and evaluated by phleborrheography and PPG at three-month intervals for one year. The patients were instructed to wear fitted, graded compression hosiery after hospital discharge; compliance was 37% at one year. The primary reason for noncompliance was socioeconomic. The price of the ideal graded compression hosiery was not easily within reach of this population and insurance reimbursement was difficult or impossible to obtain. Complaint patients felt better while wearing the compression hosiery. Increasing deterioration of qualitative PPG values of deep-valve assessment was found in both compliant and noncompliant patients at each testing interval. The PPG value deteriorated as time increased with or without the compression hose, although symptoms lessened when the prescribed hosiery was worn. The long-term sequelae of wearing or not wearing the hosiery are yet to be determined, but PPG assessment is normalized with the hosiery in place.

Adult↗
PubMed1989

Primary repair vs. colostomy for the treatment of penetrating colon injuries.

The charts of 81 consecutive patients with penetrating colonic trauma were reviewed. Sixty-five patients were considered for evaluation. Penetrating abdominal trauma index, associated injuries, length of operative procedure, wounding agent, length of hospital stay, method of treatment, and septic complications were evaluated. Twenty-eight patients were treated with colostomy at the site of injury: five with diverting colostomy proximal to repair, 30 with primary repair (either single or multiple injuries), and two with exteriorization and early drop back. Overall septic morbidity was 15 of 65 (23 percent) patients. No statistically significant difference was found in morbidity between colostomy, 9 of 33 (27 percent), and primary repair, 6 of 30 (20 percent). The two patients with exteriorized repairs had no morbidity. No deaths were reported among the 65 patients studied. Thirty-two of the 33 (97 percent) colostomies were later closed with morbidity in 7 of 32 (22 percent). The mean length of stay for primary repair patients was 10.3 +/- 2.8 days and for colostomy patients, 25.7 +/- 3.8 days, counting days for both initial and colostomy closure admissions (P less than .05). Colostomy was not mandated by anatomic location or number of colonic injuries, circumference of colonic wall involved, presence of fecal contamination, or involvement of mesenteric blood supply. This study indicates that primary repair does not carry an increased risk of septic complications and saves the patient the significant risk and increased hospital stay of colostomy closure. Prospective studies addressing this area are indicated.

Adult↗
PubMed1989

College students' knowledge and health beliefs about AIDS: implications for education and prevention.

A questionnaire designed to measure the application of the dimensions of the Health Belief Model (HBM) to AIDS prevention and to practicing safer sex was administered to 139 undergraduates aged 22 years and under. Students generally had good knowledge about the facts of AIDS, which was consistent with other studies. We found an important difference between students' beliefs about practicing safer sex to prevent AIDS depending on whether their level of knowledge was high or low. The HBM posits that all of its dimensions must be present in order for belief to be followed by action. However, students with low knowledge indicated that the perceived barriers to practicing safer sex were higher than did students with high knowledge about AIDS. These results suggest that special efforts need to be made to teach students with low knowledge more about AIDS and that the barriers to safer sex can and should be overcome. There were no differences between students known to be sexually active compared with those who may or may not have been sexually active. One explanation was a possibly high number of students in the group identified as "perhaps sexually active" who actually were sexually active. Similarly, there were no differences between college students who did or did not know someone with AIDS, but this may have been due to the small number of students who did know such a person. Students' preferences for the format and methodology of AIDS education also were presented. In general, the students preferred small-group discussions and formats such as movies or panel discussions where they could remain "anonymous."(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1989

Penetrating injuries to the colon: analysis by anatomic region of injury.

The preferred method for the treatment of penetrating injuries to the colon remains a source of controversy. In our retrospective review of 65 patients with penetrating colon injuries, 33 patients were managed by colostomy formation, 30 were treated by primary repair, and two had exteriorized repair with early return to the abdominal cavity (drop back). The anatomic location of injury was ascending colon in 19 (29%), transverse colon in 20 (31%), descending colon in 22 (34%), and multiple sites in four (6%). The average penetrating abdominal trauma index (PATI) was 24 (ascending colon injuries, 23; transverse colon, 26; descending colon, 24; and multiple colon sites, 28). Overall septic morbidity was 15/65 (23%). Colostomy closure was later done in 32/33 (97%), with a morbidity of 7/32 (22%). The mean length of hospital stay for primary repair was ten days and for colostomy (including both required hospital stays), 26 days (P less than .05). These data suggest that primary repair is as safe as colostomy formation for the management of penetrating colon injuries, regardless of anatomic site of injury.

Adult↗
PubMed1989

Erythropoietin production in exhypoxic polycythemic mice.

Our present study was undertaken to determine the serum erythropoietin concentration (radioimmunoassay), hematocrit, red cell mass, and body weight of mice exposed to hypoxia in a hypobaric chamber (0.42 atm, 22 h/day) for 14 days and during the 10 posthypoxic days at ambient pressure to clarify the correlation of the red cell mass and erythropoietin production during hypoxia. The mean serum erythropoietin titer was 326.23 +/- 77.04 mU/ml after 2 days, reached the highest level after 3 days (452.2 +/- 114.5 mU/ml), then gradually declined to a level of 36.5 +/- 11.4 mU/ml after 14 days of hypoxia, and was undetectable during the 10-day posthypoxic period. The hematocrit values were significantly increased from 41.09 +/- 0.50% at day 0 to 51.65 +/- 1.08% after 3 days and to 72.20 +/- 1.53% after 14 days of hypoxia. The red cell mass (calculated from initial body weight) increased from 3.24 +/- 0.1 ml/100 g at day 0 to 7.32 +/- 0.46 ml/100 g after 14 days of hypoxia and declined to 6.66 +/- 0.53 ml/100 g at the end of the 10-day posthypoxic period. The mice lost weight while they were in the hypobaric chamber and showed a significant increase in body weight during the 10-day posthypoxic period. These studies support the concept that chronic intermittent hypoxia causes an early increase, followed by a rapid decline, in erythropoietin production, which is correlated with the gradual increase in red cell mass.

Animals↗
PubMed1989

Lower limb embolus: a near-lethal disease after age 75 years.

Because it has been suggested that embolectomy increases morbidity and mortality, we reviewed our experience with lower-extremity embolectomy in an elderly high-risk population. Of 153 consecutive patient records reviewed, 69 were sufficiently complete for analysis. Of these patients, 45 were men with a mean age of 80.7 years (range, 75 to 91 years); 24 were women with a mean age of 76.9 years (range, 75 to 81 years). Records were reviewed for patient age, sex, race, acute myocardial infarction or atrial fibrillation upon admission, history of smoking, diabetes, and cardiac disease (acute and chronic), admission blood pressure, role of postoperative echocardiography, and New York Heart Association classification (NYHA class). All patients were hemodynamically stable at the time of operation. Forty-two of the 69 patients had a history of smoking, nine were diabetic, and 48 (33 men and 15 women) had hypertension (blood pressure greater than 140/90 mm Hg) on admission. Twelve deaths occurred within the perioperative period. Nine patients had an acute myocardial infarction and 12 had arrhythmias on admission. Thirty patients (15 men and 15 women) were in NYHA class III. A total of 30 patients had died by six months postoperatively, 27 of cardiovascular causes. The perioperative mortality was 12/69 (17%), and long-term mortality was 30/69 (43%). Simultaneous embolus and myocardial infarction was associated with 100% mortality for the patients surviving the operation; 15 patients required another operation for amputation (nine above-knee and six below-knee).

Age Factors↗
PubMed1989

Penetrating injury to the carotid artery. A reappraisal of management.

Penetrating trauma remains the most common cause of cervical carotid artery injury. Controversy persists regarding proper management of these injuries, especially in the presence of a neurologic deficit. Recent experience with 24 patients over a 5-year period is reviewed. In patients with preoperative neurologic deficits, neither repair nor ligation of the injured vessel altered outcome. Outcome correlated only with preoperative neurologic status. All patients without preoperative neurologic deficits should have repair attempted when technically feasible. Although controversial, this study supports carotid artery repair except in comatose patients who have profound neurologic deficits.

Adult↗
PubMed1988

On the dependence of the elasticity and strength of cancellous bone on apparent density.

This paper presents a statistical analysis of the pooled data from a number of previous experiments concerning the dependence of the Young's moduli and strength of cancellous bone tissue upon apparent density. The results show that both the Young's moduli and the strength are proportional to the square of apparent density of the tissue and are therefore proportional to one another. It is shown that the coefficient of proportionality is different for human and bovine tissue. It is concluded that the suggestion of Wolff (Das Gesetz der Transformation der Knochen, Hirschwald, Berlin, 1892) that compact bone tissue is simply more dense cancellous bone tissue is not an accurate statement when only the mechanical properties of these two tissues are considered. It is noted that estimates for the elastic modulus of the individual trabecula of human cancellous bone vary from 1 to 20 GPa and it is suggested that this question needs further study.

Biomechanical Phenomena↗
PubMed1988

Measurement of impotence by laser Doppler flowmetry and conventional methodology.

The problem of vasculogenic impotence was evaluated by laser Doppler flowmetry with the LD5000 capillary perfusion monitor to determine cutaneous penile blood flow in 25 men defined previously as impotent by Doppler ultrasound with penile brachial ratios of 0.63 +/- 0.14. Erotic visual stimulation for 1, 2 and 4 minutes did not statistically change the cutaneous flow as measured by laser Doppler flowmetry from its baseline of 20 mv. The dynamics of skin microcirculation in the penis may reflect changes in the deeper vessels and represent an alternate, dependable method to evaluate capillary perfusion.

Adult↗