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Biomedical subjects

W Anderson

Publications and source records attributed to W Anderson.

208 records · Page 12Linked to original sources
PubMedDate not supplied

Morphologic and endocrine changes in the reproductive organs in rats implanted with gossypol acetate pellet in the testis.

Gossypol acetate pellets in concentrations ranging from 0.5, 1.0, 5.0, 10.0, to 20.0 mg were implanted in the testis of rats for a period up to 7 weeks. The implant was made in one testis only. In animals with a 10.0-mg implant, the germinal epithelium showed degenerative changes following the 7-week period, but spermatogonia and spermatocytes were unaffected. The effect of gossypol acetate appeared to be at the spermatid level. The electron microscopic study showed that the acrosomal membranes were disrupted. Blood testosterone and LH, but not FSH, decreased significantly (P less than 0.01). The fertility studies showed 100% infertility but no loss in libido in the 10-mg implant group. Up to the 7-week period, implants of less than 10 mg produced no significant effects on any of the parameters mentioned above. Animals with 20-mg implants had toxic symptoms. From the results in this study, it is concluded that 10.0 mg of gossypol acetate implanted in a single pellet in one testis causes antispermatogenic effects.

Animals↗
PubMedDate not supplied

Neuropeptide Y, peptide YY, and pancreatic polypeptide modulate duodenal and colonic motility at a thoracic spinal site in rats.

Neuropeptide Y, PYY, and PP (200 pmol) alter intraluminal pressure in the duodenum and colon of rats following their administration into the thoracic (T8-T10) region of the spinal cord. Neuropeptide Y decreases the tone of the duodenum and the colon following intrathecal (T8-T10) administration prior to an increase in tone to baseline or greater. There is no effect on intraluminal pressure of either the duodenum or the colon following intrathecal administration of NPY or PP into the lumbar (L4-L5) region of the spinal cord. Following intrathecal (T8-T10) administration of PYY and PP, increases in intraduodenal pressures are observed (+2.1 and +3.0 mmHg from saline baseline). Phasic contractions of the duodenum are increased following intrathecal administration of PYY into the thoracic spinal cord of rats. Neuropeptide Y, PYY, and PP increase intracolonic pressure +2.2, +3.3, and +3.7 mmHg from saline baseline, respectively. Phasic contractions of the colon are increased following PP intrathecal thoracic administration. Responsiveness of the duodenum or colon to the different ligands of the PP-fold peptide family in the absence of alpha-adrenergic blockade did not vary. The increases in intraluminal pressure of the duodenum and colon following intrathecal administration of the PP-fold peptides are attenuated by both alpha-1 adrenergic (prazosin) and alpha-2 adrenergic (yohimbine) blockade. There is a difference in responsiveness of the colon between the ligands of the PP-fold family in the presence of the alpha-2 adrenergic blockade. The findings of this study indicate that duodenal and colonic motility are modulated by the PP-fold peptides at thoracic spinal sites via alteration of sympathetic outflow.

Animals↗
PubMedDate not supplied

The peripheral modulation of duodenal and colonic motility in rats by the pancreatic polypeptide-fold family: neuropeptide Y, peptide YY, and pancreatic polypeptide.

Neuropeptide Y (NPY), peptide YY (PYY), and pancreatic polypeptide (PP) altered intraluminal pressure in the duodenum and colon of fasted anesthetized rats following intravenous bolus administration. There were rapid increases in intraluminal pressure of the duodenum and colon of anesthetized rats following peripheral injections of NPY, PYY and PP. Administration (IV) of NPY, PYY, and PP increased intraduodenal pressure +1.8, +3.2, and +3.7 mmHg compared to saline baseline. Prazosin, an alpha-2 adrenergic antagonist, did not alter the response of the duodenum of urethane-anesthesized rats to any of the PP-fold peptides following peripheral administration. Yohimbine, an alpha 2-adrenergic antagonist, attenuated the excitatory response of rat duodenum following NPY (IV) but did not alter the duodenal response to PP (IV). Intravenous NPY, PYY, and PP increased intracolonic pressure +2.0, +3.3, and +6.2 mmHg compared to saline baseline. In the presence of prazosin, an alpha 1-adrenergic antagonist, the intraluminal pressure of the colon increased +2.6, +2.4, and +8.1 mmHg compared to saline baseline by NPY, PYY, and PP (IV), respectively. In the presence of alpha 2-adrenergic blockade by yohimbine, NPY, PYY, and PP (IV) increased intraluminal pressure of the colon +4.2, +2.9, and +2.5 mmHg compared to saline baseline. The response of the duodenum to the excitatory effect of PYY (IV) was enhanced in the presence of yohimbine. Duodenal and colonic tone were modulated by the PP-fold peptides following peripheral administration. The alpha-adrenergic nervous system played only a minor role in the modulation of GI motility by the PP-fold peptides at peripheral sites.

Animals↗
PubMedDate not supplied

Evaluation of a respiratory rate monitor in postsurgical patients.

STUDY OBJECTIVE: To evaluate the clinical use of a cardiorespiratory rate monitor in patients receiving epidural opioids following major surgery. DESIGN: For 6 hours during the night following surgery, patients were continuously monitored with a cardiorespiratory rate monitor and a pulse oximeter, as well as by an in-room observer. SETTING: Postoperative surgical ward at a university hospital. PATIENTS: Eight ASA physical status I and II patients ages 30 to 76 years. INTERVENTIONS: Any bradypneic, hypoxemic, bradycardic, or tachycardic event was confirmed by the observer and recorded. MEASUREMENTS AND MAIN RESULTS: The cardiorespiratory rate monitor accurately identified true bradypneic episodes in five of the eight patients. There were no false-positive alarms. The respiratory rate monitor and the pulse oximeter identified one episode of hypoxemia. There were no episodes of bradycardia or tachycardia. CONCLUSIONS: The cardiorespiratory rate monitor is useful in patients at risk for bradypnea following surgery.

Adult↗
PubMedDate not supplied

Effects of EMS transportation on time to diagnosis and treatment of acute myocardial infarction in the emergency department.

INTRODUCTION: Recent studies have documented decreased time to emergency department (ED) thrombolytic therapy with the use of prehospital electrocardiography. PURPOSE: Is the time to ED diagnosis and treatment of acute myocardial infarction (AMI) patients with thrombolytic agents decreased by emergency medical services (EMS) transport when compared with those transported by other means (non-EMS)? DESIGN: Retrospective, case-control study. POPULATION: The AMI patients treated with thrombolytic agents at a 34,000-visit, community hospital ED during 1992. METHODS: Review of records of patients who received thrombolytic therapy for AMI. Statistical analysis was performed using "Student's" t-test and Yates corrected Chi-square (chi 2). RESULTS: Eighty-seven patients received thrombolytic agents for AMI during 1992; 33 arrived by ambulance, 54 arrived by other methods. There were no differences in age, gender, or time of ED arrival among these groups. Ambulance patients received standard advanced life support (ALS) care, but not a 12-lead electrocardiogram (ECG) or thrombolytic agents. Ambulance patients experienced a significantly shorter time to first ECG (12.9 +/- 9.1 min. versus 20.8 +/- 25.3 min.; p = .028) and received thrombolytic therapy sooner than did controls (56.0 +/- 31.5 min. versus 78.0 +/- 63.4 min.; p = .018). There was no difference in time from diagnosis to treatment between these groups. CONCLUSION: Emergency medical services transport of AMI patients in this study decreased time to diagnosis and treatment and may be a confounder in studies that assess the value of field EMS interventions. Non-EMS AMI patients did not receive as rapid diagnosis and treatment, and emergency physicians should evaluate and address this issue in their departments.

Ambulances↗
PubMedDate not supplied

The Ok Tedi Health and Nutrition Project, Papua New Guinea: physique, growth and nutritional status of the Wopkaimin of the Star Mountains.

A survey was carried out to establish baseline anthropometric and health data in the Wopkaimin, a small group of Mountain Ok-speaking hunter-horticulturalists who live in a remote and isolated part of the Highland fringe of Papua New Guinea, where a major gold and copper mine is being developed. Malaria is hyperendemic in the region and infant mortality has been estimated at approximately 230 per thousand. A 79% sample of the population was examined and the results of the anthropometric survey are reported. Wopkaimin childrens' heights and weights are well below the 50th percentile of British standards throughout growth; at maturity boys' weights and girls' heights and weights are at or below the 3rd percentile, and boys' weights are just above the 10th percentile. Wopkaimin children lag far behind British children in percentage of adult height achieved at all ages, and appear to attain maturity at least four years later. This relatively slow growth and short adult stature may represent an adaptive response to chronic nutritional deprivation, for which there is evidence from skinfold thickness and arm circumference measurements. Younger adults are significntly taller, heavier, fatter and more muscular than older adults; possible explanations for this are discussed. Within the sample, individuals living in villages less than a day's walk from the mine town are significantly taller, heavier and fatter than those living further away, and there are also similar significant anthropometric differences between employed and unemployed men. Ready food availability which has come with the mine development appears to be the most likely explanation for these differences. A continuing study of changing patterns of health and nutrition in the area has been initiated.

Adolescent↗
PubMedDate not supplied

[Effects of endocrine peptides on proliferation, migration and differentiation of human endothelial cells].

AIMS: We aimed to evaluate the effects of several peptides (substance P, VIP, neuropeptide Y, bombesin, glucagon and somatostatin) on the proliferation, migration and differentiation of human endothelial cells and their modulation by an anti-angiogenic factor, endostatin. METHODS: Human endothelial cells (HUVEC) were isolated from umbilical veins. Their proliferation was measured by the incorporation of tritiated thymidine. Their migration was evaluated by using an haptotactic assay performed in Boyden chambers, after metabolic labeling of HUVEC through (35) S-methionin. Differentiation was evaluated as the capacity for HUVEC to form capillaries. RESULTS: Endothelial cell proliferation was increased by neuropeptide Y, bombesin and glucagon. Somatostatin induced a significant decrease in basal and stimulated endothelial cell proliferation. The migration of HUVEC increased in the presence of substance P, VIP, neuropeptide Y, bombesin, glucagon and somatostatin. The number of capillaries was increased by substance P and VIP and decreased by neuropeptide Y, bombesin and somatostatin. Endostatin induced a significant decrease in endothelial cell proliferation in the basal state and after stimulation by neuropeptide Y and bombesin. Endostatin had no additive effect on the anti-proliferative action of somatostatin. CONCLUSIONS: Our results suggest a role for endocrine peptides in the regulation of tumor angiogenesis. The potent anti-angiogenic effect of somatostatin may promote new therapeutic strategies.

Bombesin↗