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Biomedical subjects

R Ferguson

Publications and source records attributed to R Ferguson.

At least 73 records · Page 4Linked to original sources

Transfusion-associated AIDS: donor-recipient human immunodeficiency virus exhibits genetic heterogeneity.

The genetic diversity of the human immunodeficiency virus (HIV) isolated from transfusion-associated AIDS patients has been examined. Restriction enzyme mapping studies of integrated proviral DNA of donor and recipient origin demonstrated genomic variation between isolates. Analysis of the molecularly cloned viral genomes of one donor-recipient pair showed that virus from the recipient had restriction enzyme site differences from the donor, noticeably clustered in the env and orf-2 regions, and also had a greater number of restriction sites in common with the donor as well. These results suggest that HIV may undergo genomic variation in vivo. Comparison of donor-recipient viruses may further the understanding of the molecular basis for AIDS pathogenesis.

Acquired Immunodeficiency Syndrome↗

Cisapride: influence on oesophageal and gastric emptying and gastro-oesophageal reflux in patients with reflux oesophagitis.

A preliminary, double-blind placebo controlled trial of cisapride in reflux oesophagitis was conducted. Eighteen patients were allocated to treatment with either placebo or cisapride, 10 mg three times daily, orally, before meals. Gastric emptying of a scrambled egg meal, oesophageal transit of a liquid bolus and ambulatory monitoring of oesophageal pH were assessed before and after four weeks' therapy. Overall, gastric emptying rates were not influenced by cisapride, although a small but significant reduction in gastric isotope retention, 20 minutes after meal ingestion was observed in patients on the active drug. Oesophageal transit times were not altered by cisapride. A small but significant reduction in the duration of gastro-oesophageal reflux followed cisapride therapy when compared with placebo.

Adult↗

The effect of antibiotic therapy before admission to hospital on recognition of the causative organism in acute bacterial meningitis.

A large series of patients with acute bacterial meningitis has been reviewed in order to determine whether antibiotic treatment before admission to hospital adversely affects recognition of the causal organisms. Although bacteria were identified less often in those who had had pre-admission antibiotics compared with those who had not, the difference was not statistically significant.

Acute Disease↗

Comparative observation of fibroblasts derived from the papillary and reticular dermis of infants and adults: growth kinetics, packing density at confluence and surface morphology.

We have confirmed the reports of Harper and Grove (Science, 204 (1979) 526-527), and Azzarone and Macierira-Coehlo (J. Cell Sci., 57 (1982) 177-187) that fibroblasts derived from the papillary dermis have greater in vitro growth potential and longer replicative lifespans than genomically identical fibroblasts derived from the reticular dermis. In addition we demonstrate that the kinetics of cell replication differ for papillary and reticular fibroblasts derived from infant and adult donors. Infant papillary fibroblasts replicate at faster rates than reticular fibroblasts throughout the growth cycle. Adult papillary and reticular fibroblasts replicate at similar rates at low cell densities, but exponential growth of reticular fibroblasts slows at lower cell densities than papillary fibroblasts suggesting that they are more sensitive to density-dependent inhibition of replication. The surface morphologies of reticular fibroblasts and papillary fibroblasts at confluence correlate with their growth kinetics. The decreased cell yields of reticular fibroblasts appears related to the spreading behaviors of individual cells which stretch and occupy more area of the growth surface than do papillary fibroblasts. These data and the reports cited clearly show that one must account for the presence of at least two distinct populations of dermal fibroblasts when examining their biological properties in vitro.

Adult↗

Lidocaine removal during resin hemoperfusion for phenobarbital intoxication.

A deeply comatose patient with severe phenobarbital intoxication was hemoperfused with an Amerlite XAD-4 column. She was receiving lidocaine for ventricular ectopy. The rate of lidocaine infusion had to be increased to control ventricular arrhythmias during hemoperfusion. Plasma clearance for lidocaine by the column was 122 ml/min at initiation and 75 ml/min at 2 h. These findings suggest that an increment in lidocaine infusion may be needed during resin hemoperfusion in patients receiving this drug because of its removal by the column.

Female↗

The usefulness of the Denver Developmental Screening Test to predict kindergarten problems in a general community population.

The Denver Developmental Screening Test (DDST) was administered to 2,569 children five to seven months prior to starting kindergarten in September 1980 in a geographically well-defined community. The test was administered by trained public health nurses. At the end of the 1980-1981 school year, all 163 kindergarten teachers in the area completed a rating form for each child in their class. The rating form determined global ratings of: 1) learning abilities; 2) classroom behavior; 3) amount of special attention required; and 4) referrals to special education services outside the classroom. The specificity of the DDST in predicting kindergarten teacher ratings was 99 per cent for all areas. Test sensitivity varied from 5 per cent to 10 per cent in detecting problems in the four areas. The predictive values of an positive test varied from 31 per cent for behavior problems to 62 per cent for extra attention required in the classroom. Negative test predictive values varied from 79 per cent to 93 per cent. These results based on kindergarten teacher ratings suggest that, because of the low sensitivity and modest predictive value, the DDST may be relatively inefficient to use in a school entry screening program in a general community population of children.

Child, Preschool↗

Morphologic alterations in the Purkinje neuron of the rat induced by lysergic acid diethylamide and fixation.

The effect of lysergic acid diethylamide (LSD) on the morphology of the cerebellar cortex of the rat was studied with electron microscopy. Hippocampal electrical activity was used as an objective measure of drug efficacy. At a dose of 1700 micrograms/kg, the amplitude from the hippocampus was diminished (in 2 to 5 min) and this effect lasted for about 65 to 165 min. A morphologic alteration consisting of cisternal stacks occurred in the dendrites of Purkinje neurons of rats treated with this dose of LSD, with the perfusion carried out correctly. These stacks of smooth endoplasmic reticulum were seen 2 h after injection and persisted for at least 8 h. A reduction in the volume of perfused fluid to less than 500 ml caused similar changes in the dendrites of the Purkinje neuron of untreated rats; this was one way to experimentally induce a faulty perfusion. With LSD and faulty perfusion (reduced volume) more severe changes occurred in the dendrites and small stacks of smooth endoplasmic reticulum were seen in the Purkinje soma; similar changes were also seen when the perfusion of a control animal was mismanaged during the initial 3 min. The Purkinje neuron seems to manifest morphologic alterations, generally of two types, with exposure to a variety of noxious agents. The LSD caused some perturbation of this neuron, and this was found under properly controlled conditions of fixation. The results are interpreted as indicating that LSD is causing a metabolic alteration which could disrupt the synaptic activity over several hours.

Animals↗

Mitogen responsiveness and inhibitory activity of mesenteric lymph node cells. Conditioned medium containing T cell growth factor reverses suppressor function.

Blood-, lymph node-, and tumour-infiltrating lymphocytes (PBL, LNC, and TIL, respectively) from patients with colonic neoplasms were tested for responsiveness to phytohaemagglutinin (PHA). All populations responded, with LNC and PBL showing comparable reactivities while TIL were less reactive as assessed by incorporation of 3H-thymidine. Increased mitogen responsiveness was observed for T cells enriched by SRBC rosette formation or passage through nylon columns. Mitomycin C-treated LNC and TIL inhibited PHA induced 3H-thymidine incorporation of admixed autologous PBL, suggesting the presence of suppressor cells. Suppressor activity resided primarily in the SRBC rosetting population and was dose-dependent, with increasing numbers of LNC giving greater diminution of PHA response. Suppression by LNC was apparent only when they were added to PBL responders within 6 h of the initiation of stimulation assays, in common with the effects of Concanavalin A (Con A)-induced suppressors on PBL phytomitogen responsiveness. Con A-induced and LNC-suppressor activity could be reversed by addition of lymphocyte-conditioned medium (CM) containing T cell growth factor (TCGF; interleukin IL-2). These data provide further evidence that the suppressor phenomena observed in this system are a function of activated T cells present both in drainage lymph nodes and at the tumour site.

Cells, Cultured↗

Improved patient and primary renal allograft survival in uremic diabetic recipients.

From January 1968 to December 1981, 470 uremic diabetic patients received primary renal allografts at the University of Minnesota. Until 1979, the patient and graft survival rates were less good in diabetic than in nondiabetic recipients. Since 1979, the results in diabetics have been at least equal to those achieved in nondiabetic patients. Two-year actuarial patient and graft survival rates in diabetic renal allograft recipients were, respectively, 71 and 66% from 1968 to 1976 (n = 156), 78 and 64% from 1976 to 1979 (n = 187), and 88 and 82% from 1979 to 1981 (n = 127). Improved survival rates were seen in all donor source and recipient age categories. For comparison, the 2-year patient and graft survival rates in nondiabetic renal allograft recipients who received transplants between 1979 and 1981 (n = 162) were 92 and 79%. Changes associated with improved survival rates included performance of pretransplant splenectomy on all patients except those receiving grafts from HLA-identical siblings, deliberate transfusions of blood from greater than or equal to 5 random donors at least 1 month before transplantation, intensive insulin therapy for diabetic management post-transplant, and less vigorous treatment of repetitive rejection episodes. The current results show that diabetic recipients are no longer at higher risk than nondiabetics for graft or patient loss, at least during the first 2 years after transplantation.

Adolescent↗

Palliative intubation of oesophagogastric neoplasms at fibreoptic endoscopy.

Of one hundred and twenty-one patients with neoplastic obstruction of the oesophagus or cardia 118 underwent palliative intubation at fibreoptic endoscopy on a total of 135 occasions. Sixty had adenocarcinoma, 49 had squamous carcinoma, and in nine the oesophagus was involved by a growth arising elsewhere. Satisfactory swallowing ws restored in 112 patients. Thirteen patients died in hospital shortly after the procedure. Five fatal and 10 non-fatal perforations were sustained in 135 intubation procedures. Complications of tube function included food blockage on 26 occasions, tumour overgrowth on seven occasions, displacement on 16 occasions, disappearance of the tube in two patients, and late oesophageal perforation on nine occasions. Fifty-six patients survived for three months, 33 for six months, and 10 for a year after intubation. Comparison with series in the literature of patients who underwent surgical palliative intubation suggests that endoscopic palliation has lower mortality and morbidity, and an increased survival time, and is now the method of choice for palliation of oesophagogastric neoplasms.

Adenocarcinoma↗

Catecholamine neurons of the central nervous system in organotypic culture.

A standardized dissection has been designed to produce explants from the locus coeruleus of the newborn mouse brain. This area, termed the peduncular region, may be explanted with or without cerebellar neurons. Organotypic cultures with peduncular cells contain a cluster of 20-50 (or more) closely-packed large neurons, characterized by intracellular refractile granules in the living state. When treated with the glyoxylic acid method, somata of the granule-containing neurons exhibited catecholamine fluorescence, and a profuse plexus of varicose fluorescent fibers permeated the explant and its outgrowth. Intracellular staining of these cells with horseradish peroxidase demonstrated bipolar and multipolar neurons (25-30 micrometers), with stout dendrites and varicose axons. Granule-containing neurons stained for acetylcholinesterase. Electron microscopically, large dense granules were seen, which appear to correspond to the granules seen in living neurons. Cultures with these cells also have a high concentration of catecholamines in the medium. It is concluded that the granule-bearing neurons of the living culture are in fact neurons of the locus coeruleus.

Acetylcholinesterase↗

Coeliac disease, fertility, and pregnancy.

The effect of coeliac disease and its treatment on fertility and pregnancy in 74 patients is reported. Those on a normal diet had a shorter reproductive period, were relatively infertile, and had a higher incidence of spontaneous abortions than those on a gluten-free diet. Although maternal health did not appear to be seriously impaired by pregnancy in undiagnosed coeliacs, those on a gluten-free diet had significantly fewer symptoms and had heavier babies.

Abortion, Spontaneous↗

Celiac disease and malignancy.

Fifty-five patients with celiac disease and coexistent malignant disease (27 lymphoma, 28 other malignancies) are described. The important clinical features at presentation of lymphoma were weight loss, abdominal pain, diarrhea, profound weakness and fever, associated with anemia, raised ESR, hypoalbuminemia and steatorrhea. There were no specific features to enable earlier diagnosis. Radiology was unhelpful and in no case were malignant cells seen in the jejunal biopsy. Four of the lymphomas were Hodgkin's disease, none of which involved the bowel; the remainder were reticulum cell sarcoma, 17 of which involved the bowel. Definitive diagnosis prior to death was made in only 18 patients, of whom 16 survived from 2 to 226 days (mean, 76 days). Of the remaining two patients, one is still alive, while the other died 26 years after the original diagnosis of Hodgkin's disease. The possibility of lymphoma should be considered in those who present with celiac disease in middle life and in those who deteriorate for no apparent reason after a period of stability on a gluten-free diet. The index of suspicion for lymphoma in celiac disease should be high and early laparotomy be considered in patients with unexplained deterioration. Twenty-eight patients with 29 carcinomas and 3 other tumors are also described. The presentations of these malignancies were no different from their presentations in non-celiac patients, and their development did not provoke a relapse of celiac disease. Considering the whole series of 55 patients, there was little evidence for the view that malignancy itself was the cause of the flat jejunal mucosal appearances seen in these patients.

Adult↗