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Biomedical subjects

R Cooper

Publications and source records attributed to R Cooper.

At least 145 records · Page 8Linked to original sources
PubMed1994

Primer residues deposited by handguns.

There is much anecdotal information being disseminated, even offered in expert witness testimony, concerning the deposit of primer residues on the hands of persons in front of the muzzle of handguns. We present data for 9 mm and 380 Auto pistols and for a 38 caliber revolver depicting the procedure for obtaining wipings taken from targets representing the hands of a gunshot victim. These wipings from pork tissue were then analyzed for the primer residue metals antimony, barium, and lead. The data show that the two primary metals, antimony and barium, are deposited on the targets out to 4 feet for the pistols and out to three feet for the 38-caliber revolver. Testing will continue in actual cases with the gun and ammunition involved in the shooting.

Animals↗
PubMed1994

Radiofrequency catheter ablation as a primary therapy for treatment of ventricular tachycardia in a patient after repair of tetralogy of Fallot.

A 20-year-old man with previous surgical repair of tetralogy of Fallot was admitted with hemodynamically significant ventricular tachycardia that was terminated with cardioversion. He was found at electrophysiological study to have easily inducible ventricular tachycardia that was mapped to the right ventricular outflow tract. Radiofrequency catheter ablation of the ventricular tachycardia focus rendered the patient's arrhythmia noninducible. This case represents a successful radiofrequency catheter ablation of a ventricular tachycardia focus associated with tetralogy of Fallot repair.

Adult↗
PubMed1994

Angiotensinogen gene in human hypertension. Lack of an association of the 235T allele among African Americans.

The frequency of the 235T and 174M alleles of the angiotensinogen gene, previously reported to be associated with hypertension in Caucasians and Japanese, was compared between 57 hypertensive African Americans and 130 normotensive African Americans sampled as part of a community survey of hypertension in the Chicago area. The frequency of the 235T allele was unrelated to hypertension status (cases, 83%, control subjects, 82%), as was true for the 174M allele. Compared with Caucasians, the frequency of the 235T allele was twice as high in this African American population, while the frequency of the 174M allele was similar. Even higher frequencies of the 235T allele (93%) were noted in a sample of 122 Nigerians. It appears that the 235T allele is very common in populations of West African origin, although we found no evidence that it confers risk of hypertension.

Adult↗
PubMed1994

WIN 66306, a new neurokinin antagonist produced by an Aspergillus species: fermentation, isolation and physico-chemical properties.

WIN 66306 (1a), a cyclic peptide containing a novel amino acid, was isolated as a neurokinin antagonist from an Aspergillus species, labelled SC230. Conditions that maximized the production of 1a were developed, leading also to production of the related compound WIN 68577 (2) and rosellichalasin (3). Both 2 and 3 were more active in the rat NK1 than in the human NK1 receptor binding assay, while 1a was more active at the human receptor with an inhibitor affinity constant of 7 microM.

Amino Acid Sequence↗
PubMed1994

Isolation and structure elucidation of two new calpain inhibitors from Streptomyces griseus.

Two new peptides, a diketopiperazine of N-methyltyrosine (1) and a tetrapeptide containing N-methyltyrosine (2), were isolated from an actinomycete strain Streptomyces griseus. These compounds inhibit the enzyme calpain in the micromolar range and were characterized on the basis of spectroscopic analysis, amino acid analysis and sequencing. The structure of the tetrapeptide N-methyltyrosyl-N-methyltyrosyl-leucyl-alanine (2), was also confirmed by total synthesis.

Calpain↗
PubMed1994

Benzomalvins, new substance P inhibitors from a Penicillium sp.

In the course of screening microbial broths for neurokinin receptor antagonists, a series of new benzodiazepines, benzomalvins A (1), B (2) and C (3), has been isolated from the culture broth of a fungus identified as a Penicillium sp. Benzomalvin A (1) showed inhibitory activity against substance P with Ki values of 12, 42 and 43 microM at the guinea pig, rat and human neurokinin NK1 receptors, respectively. Benzomalvins B (2) and C (3) were only weakly active. The structures of these compounds were determined by spectroscopic methods including MS measurements and NMR analysis.

Animals↗
PubMed1994

Peanut agglutinin binding by gastric mucosal epithelial cells in Helicobacter pylori associated gastritis.

Gastric biopsies (42) from patients with peptic ulcer disease were classified into Helicobacter pylori positive (32) and negative (10) groups, based on the results of tissue urease test and microscopic demonstration of spiral bacteria. A statistically significant difference in peanut agglutinin (PNA) binding between the two groups was observed, attributable to exposure of sialic acid residues on gastric epithelium in the H. pylori positive group. That the negative binding was due to sialic acid, was further confirmed by application of sialidase digestion technique. These results support the existing biochemical evidence for exposure of sialic acid residues on H. pylori colonized epithelium.

Adolescent↗
PubMed1994

Endoscopic ultrasound in the evaluation of Barrett's esophagus: a preliminary report.

OBJECTIVE: Endoscopic screening of Barrett's esophagus (BE) for dysplasia is imprecise and controversial. Endoscopic ultrasound (EUS) allows a detailed circumferential image of the esophageal wall. Our objective in this study was to assess the utility of EUS for surveillance in Barrett's esophagus. METHODS: Consecutive patients with proven BE undergoing endoscopy were evaluated with EUS. Esophageal wall thickness (EWT) was measured as the distance from the balloon-mucosal interface to the outermost hyperechoic line. EWT was determined as the average of all measurements done every 2-3 cm along the esophagus. Identical measurements were performed in a series of controls. RESULTS: Fifteen patients with BE and 13 control patients were studied. Two patients had focal submucosal thickening on EUS with EWTs of 10 mm and 7 mm. Surgical resection of the esophagus in these two cases with high-grade dysplasia revealed submucosal carcinoma at the area of EUS-documented thickening. The mean EWT of controls measured 2.6 mm, nondysplastic BE measured 3.3 mm, and BE with dysplasia measured 4.0 mm. The EWT of both dysplastic and nondysplastic Barrett's was significantly greater than that of the controls (p < 0.02, Student's t test). CONCLUSIONS: 1) As measured by EUS, the esophageal wall is significantly thickened in the columnar-lined portion of Barrett's esophagus. 2) EUS-detected focal thickening may represent submucosal carcinoma in areas of dysplasia and guide early surgery. Thus, EUS may play a role in evaluating the patients with dysplasia in Barrett's esophagus.

Adult↗
PubMed1993

Race, income, and survival from breast cancer at two public hospitals.

BACKGROUND: Some studies have shown that adjustment for socioeconomic status reduces breast cancer survival differences between blacks and whites. The purpose of this study is to evaluate the effect of age, race, stage, treatment, and income status on breast cancer survival among women attending public hospitals in Chicago, Illinois. METHODS: Hospital Cancer Registry data on 887 black women and 265 white women with breast cancer onset between 1973-1985 were analyzed using Cox regression and Kaplan-Meier techniques. The purpose was to examine the effect of age, race, stage, treatment, and income on breast cancer survival. RESULTS: Black women with breast cancer were younger and poorer than white women with breast cancer. There were no significant differences between blacks and whites with regard to stage, estrogen receptor status, or type of treatment. Black women had lower 5-year breast cancer survival rates compared to white women (50.2% versus 60.2%; P = 0.05), and survival was lower when adjusted for stage and age. However, when adjusted for income in addition to stage and age, the effect of race on survival was reduced (from relative risk = 1.26; 95% confidence interval = 1.02, 1.57 to relative risk = 1.17%; 95% confidence interval = 0.95, 1.38). CONCLUSIONS: Income influences breast cancer survival differences between blacks and whites in this population.

Black or African American↗
PubMed1993

Antidromic activation of a peptidergic pathway in the limbic system of the male rat.

Stimulation of the medial amygdaloid nucleus (AME) produces a long-latency and long-lasting inhibition of pyramidal cells in both the dorsal and the ventral hippocampus. The inhibition is blocked by a specific antagonist to vasopressin, which is a candidate neurotransmitter in the system. Antidromic activation of the AME from the hippocampus occurs with a latency suggestive of the conduction velocity of small diameter unmyelinated fibers. Immunocytochemistry for vasopressin reveals small diameter, unmyelinated immunoreactive fibers in the vicinity of the stimulating electrode in the hippocampus, and immunoreactive cell bodies in the vicinity of the recording electrode in the AME.

Amygdala↗
PubMed1993

Performance of two films for densitometry of retinal photographs.

The relative performance was determined of two different photographic films (Kodak Panatomic-X and Kodak Technical Pan) for densitometry readings from retinal photographs of patients who had or were suspected of having glaucoma. The raw data from the two films were significantly different. The high contrast film was particularly sensitive to external variables; however, when normalised in terms of the standardised deviation, the data from the two films were comparable (P < 0.005). We also measured the pattern of nerve fibre layer loss using digital image analysis of red-free photographs of normal, ocular-hypertensive, glaucoma-suspect and glaucomatous eyes. Several mathematical techniques were used to characterise the data from each eye and then to compare these data to the mean photographic density of the normal eyes. Results showed that it was possible to separate normal eyes from glaucomatous eyes. The highest sensitivity achieved was 100% for right and 88% for left eyes, and the highest specificity was 100% for both eyes.

Adult↗
PubMed1993

Survey of library and information use by health-care students.

The study compares and contrasts the usage and views of three groups of health-care students (Pre-Project 2000, Project 2000 and BSc Occupational Therapy) on their library facilities. A literature review is included which underpins the importance of libraries for health-care students. Data was compiled from survey responses. The results demonstrate which libraries the students use, how often they use them, what they do in the libraries, and the stock used. They also show the level of student confidence and the services used. The implications of the study for future provision are considered.

Attitude of Health Personnel↗