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Biomedical subjects

S White

Publications and source records attributed to S White.

At least 253 records · Page 14Linked to original sources
PubMed1987

Canine cardiovascular responses to endotracheally and intravenously administered atropine, isoproterenol, and propranolol.

This study compared canine cardiovascular responses observed after endotracheally administered atropine, isoproterenol, and propranolol to those observed following IV administration. Acetylcholine and isoproterenol dose response curves for arterial pressures and heart rate were established following IV boluses of each drug. Once the dose response curves were established, atropine and propranolol were administered endotracheally and intravenously in different groups to alter the established dose response curves. The time required for endotracheally and intravenously administered atropine and propranolol to inhibit 50% of the mean arterial pressure response following an IV infusion of acetylcholine and isoproterenol, respectively, was determined. Atropine and propranolol administered by either route significantly altered the arterial pressure response to acetylcholine and isoproterenol (P less than .05), respectively. Atropine altered the heart rate response to acetylcholine when administered by either route (P less than .05). IV-administered propranolol altered the heart rate response to isoproterenol (P less than .05); endotracheally administered propranolol did not. Atropine administered IV inhibited 50% of the mean arterial pressure response during an acetylcholine infusion within 21 seconds, and within 48 seconds following endotracheal administration. Propranolol administered intravenously inhibited 50% of the mean arterial pressure response during an isoproterenol infusion within 23 seconds, and within 49 seconds following endotracheal administration. The arterial pressure and heart rate responses immediately following endotracheally and intravenously administered isoproterenol also were measured and compared. The arterial pressure and heart rate responses after endotracheally administered isoproterenol were much less than those following IV administration (P less than .005). In dogs the pharmacological effects following endotracheally and intravenously administered atropine and propranolol are similar, while the effects of endotracheally and intravenously administered isoproterenol differ greatly.

Animals↗
PubMed1986

Interviewing young sexual abuse victims with anatomically correct dolls.

Two groups of children were interviewed with a structured format to elicit their responses to sexually anatomically correct dolls. Significant differences were found between the responses of children who had not been referred for suspected sexual abuse and those who had. Nonreferred children (n = 25) revealed very few behaviors indicative of abuse whereas referred children (n = 25) demonstrated significantly more sexually related behaviors when presented with the dolls. Of the age groups studied (2-6 years), 3 year olds were the most responsive to the dolls, while older children tended either to reveal their experiences or to become very nonresponsive. The authors argue for the use of structured interview techniques with use of the anatomical dolls and the collection of normative comparison data relative to the evaluation of suspected sexual abuse.

Child Abuse, Sexual↗
PubMed1986

Neonatal intracranial hemorrhage and phenobarbital.

We enrolled 280 intubated babies with birth weights of less than 1,751 g in a double-blind randomized prospective clinical trial to evaluate whether phenobarbital influences the likelihood of developing subependymal-intraventricular-intraparenchymal hemorrhage. Phenobarbital was associated with an increased risk of developing any subependymal-intraventricular-intraparenchymal hemorrhage and was not associated with a diminished risk of either severe hemorrhage or germinal matrix hemorrhage. This increased risk was apparent even after we considered the influence of phenobarbital levels, timing of phenobarbital administrations, institutional differences, quality of ultrasound scans, gestational age- and birth weight-specific effects, ascertainment bias, and other possible confounders of phenobarbital administration.

Cerebral Hemorrhage↗
PubMed1986

Genetic analysis of plasma sitosterol, apoprotein B, and lipoproteins in a large Amish pedigree with sitosterolemia.

We previously reported the finding of phytosterolemia, xanthomatosis, and hyperapobetalipoproteinemia (hyperapoB) in five siblings in a large Amish pedigree ascertained through a 13-year-old boy who died suddenly from advanced coronary atherosclerosis. Here, we present further analyses of the plasma levels of the plant sterol, sitosterol, of low density (beta) lipoprotein (LDL) sterol, and of LDL B protein. Of 254 relatives and spouses of the proband, 90.5% were examined. A series of genetic models were explored using a pedigree analysis where parameters reflecting frequency, transmission, and penetrance of putative genotypes were examined simultaneously using a maximum likelihood approach. Segregation analysis of the sitosterol levels showed that the phenotype of sitosterolemia was controlled by a rare autosomal recessive gene. There was also significant familial correlation in plasma sitosterol levels that was attributed to a polygenic component under a mixed model but could also be due to shared environments such as diets. The recessive model was supported by our finding that the plasma sitosterol levels in the parents and in six children born to three of the five sitosterolemics were less than 1 mg/dl, well within the normal range. The phenotype of hyperapoB is based on an elevated level of LDL B protein in the presence of a normal LDL cholesterol level (low LDL sterol to LDL B ratio). For both LDL sterol and LDL B, a polygenic model showed a slightly greater improvement in ln likelihood than did the Mendelian single locus model when both were compared to a sporadic model. Similar results were obtained for sterol levels of high density (alpha) lipoprotein (HDL) sterol. When segregation analysis was performed using the ratio of LDL sterol to LDL B, the Mendelian single locus model gave a slightly better fit to the data than did the polygenic model. While the analyses presented here provided unequivocal evidence for the recessive phenotype of phytosterolemia, we also identified a possible single gene factor that could account for the major portion of the strong familial aggregation in the ratio of LDL sterol to LDL B, and to a lesser extent LDL B. However, there is clear evidence of familial aggregation for these traits in this pedigree beyond that due to Mendelian components.

Adolescent↗
PubMed1986

Progressive systemic sclerosis and Graves' disease. Report of three cases.

Progressive systemic sclerosis (PSS) is associated with a broad spectrum of autoimmune thyroid diseases. While an association between PSS and hypothyroidism is well established, a relationship between PSS and hyperthyroidism is less well defined. We treated three patients with PSS whose course was complicated by Graves' disease. Because hyperthyroidism can simulate many of the symptoms of PSS progression and treatment of hyperthyroidism can lead to resolution of clinical deterioration in such patients, it is important to recognize the simultaneous occurrence of these diseases.

Adult↗
PubMed1985

Life-threatening bacterial pneumonia in male homosexuals with laboratory features of the acquired immunodeficiency syndrome.

Two male homosexuals with laboratory features of the acquired immunodeficiency syndrome developed fulminating pneumonia requiring mechanical ventilatory support despite antibiotic therapy. Pathology consistent with bacterial pneumonia without other opportunistic pathogens were found at open lung biopsy. Cultures from the open biopsy grew Hemophilus influenzae in one, and Streptococcus pneumoniae was seen on Gram stain and sputum culture prior to antimicrobial treatment in the other. Each recovered on continued single antibiotic therapy. Life-threatening bacterial pneumonia may be a feature of the acquired immunodeficiency syndrome, possibly due to B cell abnormalities.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Induction of ovulation with pulsatile luteinising hormone releasing hormone.

Ovulation was successfully induced with luteinising hormone releasing hormone in 28 women with hypothalamic amenorrhoea who had failed to respond to treatment with clomiphene. Luteinising hormone releasing hormone was administered in a pulsatile manner with miniaturised automatic infusion systems. The rate of ovarian follicular maturation, as monitored by serial pelvic ultrasonography, was similar to that observed in spontaneous cycles. Endocrine assessment by serial measurement of gonadotrophin, oestradiol, and progesterone concentrations showed hormone concentrations to be within the normal range. Intravenous treatment was required in only two patients, the remainder responding satisfactorily to subcutaneous infusion. All patients conceived within six cycles of treatment, and only one multiple pregnancy occurred.

Adult↗
PubMed1984

Permeability of cultured megakaryocytopoietic cells of the rat to dimethyl sulfoxide.

The permeability of the membrane of the rat megakaryocytopoietic cell to dimethyl sulfoxide was measured to assess its availability to the intracellular compartment. The method used was osmotic, and measured the initial loss of cell water followed by a reswelling to isotonic volume when cells were placed in culture media containing 0.6 M DMSO. Values for the hydraulic coefficient, Lp, the permeability of the membrane to DMSO, wRT , and the reflection coefficient were calculated from the equations of Kedem and Katchalsky . The average value at 25 degrees C for Lp was 0.46 micron min-1 atm1 ; wRT was 9.3 micron min-1, and the reflection coefficient was 0.65. At these cell volumes, 50% equilibration occurred in 5 sec. Cells equilibrated in 0.6 M DMSO increased their volume of osmotically inactive water. Coupled with this phenomenon of stabilization of water was a reduction in the hydraulic coefficient by 50%. These findings are discussed in the context of current hypotheses about cellular viability during freezing and thawing in the presence and absence of cryoprotectants.

Animals↗
PubMed1984

A miniature infuser for the pulsatile administration of LHRH.

This paper describes a compact, battery-powered infuser that is light, unobtrusive and simple to operate. A novel direct-drive method is used to deliver intermittent boluses of hormone at predetermined time intervals via a special prefilled syringe. Normal pregnancy rates were achieved in anovulatory women when infused with luteinising hormone releasing hormone (LHRH).

Biomedical Engineering↗
PubMed1984

Anatomy of the palmar fascia on the ulnar border of the hand.

Dupuytren's disease sometimes seems to arise from the tendon of abductor digiti minimi or the fascia overlying it. The normal anatomy of these structures is described and the tendon is shown to be of central importance in the organisation of the digital fascia. In particular, its connections with the superficial transverse palmar ligament, Grayson's ligaments and the digital band are demonstrated.

Dissection↗
PubMed1984

Value of serum C-reactive protein measurement in the management of bone marrow transplant recipients. Part I: Early transplant period.

Serum C-reactive protein concentrations were measured serially during the early transplant period in 68 bone marrow recipients transplanted for leukaemia (34), chronic granulocytic leukaemia (2), severe aplastic anaemia (6), and various inborn errors of metabolism (26). There were 116 clearly documented episodes of infection or acute graft versus host disease or both. Serum C-reactive protein concentrations in patients with viral (11) or fungal infection (6) were normal or only slightly raised. In 32 patients with isolated acute graft versus host disease, only three (10%) showed serum C-reactive protein concentrations above 40 mg/l. Values greater than 40 mg/l were strongly suggestive of bacterial infections and values above 100 mg/l were seen only in patients (43) with bacterial infections with or without acute graft versus host disease. These findings suggest that serum C-reactive protein concentrations are valuable both for diagnosis and monitoring of such infections.

Acute Disease↗