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Biomedical subjects

S A Wilson

Publications and source records attributed to S A Wilson.

72 records · Page 4Linked to original sources

Outbreaks of astrovirus type 1 and rotavirus gastroenteritis in a geriatric in-patient population.

Two outbreaks of viral gastroenteritis occurred in seven psychogeriatric wards of a 469-bed psychiatric hospital. The outbreaks occurred over an eight-week period; the first affected 30 people and rotavirus was detected in 12 of 14 persons from whom faecal specimens were available. The second affected 32 people (15 of whom were affected in the previous outbreak) and astrovirus was detected in 5 of the 24 people from whom specimens were available. Specific IgM to astrovirus was demonstrated in 3 patients. The rotavirus outbreak was characterised by a longer duration of illness (mean 4 days), and more severe symptoms; two elderly female patients had severe symptoms over a 14-15 day period but recovered. In the astrovirus outbreak the duration of illness was shorter and symptoms were milder although the attack rate was higher than that observed for rotavirus.

Adult↗

The development and evaluation of radioimmune assays for the detection of immune globulins M and G against astrovirus.

The development and evaluation of radioimmune assays for the detection of IgM and IgG antibodies to astrovirus are described. The test was shown to be sensitive and specific, and suitable for screening large numbers of sera. The use of the assays has established that astrovirus type 1 is prevalent in the United Kingdom and that not only infants but also schoolchildren and elderly patients are affected. Further evidence is given to support the view that Marin County Agent is antigenically related to astrovirus type 1.

Adult↗

Production and characterisation of a human monoclonal antibody to cytomegalovirus and its use in an early nuclear fluorescence assay.

A human monoclonal antibody to cytomegalovirus (CMV) was produced by transforming peripheral blood mononuclear cells of a patient with recent CMV infection. It is directed against a late antigen located in the nucleus of CMV infected fibroblasts at 24-72 hours postinfection and immuneprecipitates 65K and 48K proteins from 35S-labelled CMV infected cells. Results of its use in an early nuclear fluorescence assay for rapid diagnosis are presented.

Adult↗

Chlamydia trachomatis as a cause of neonatal conjunctivitis.

Chlamydia trachomatis was identified in 37 of 73 consecutive neonates with purulent conjunctivitis, including four delivered by caesarean section with intact membranes. Most (28/37) presented in the first week. Infection was significantly associated with referral from the community. Genital C. trachomatis infection was present in 13 of 35 parents of affected infants.

Chlamydia trachomatis↗

The biliary elimination of amaranth, indocyanine green and nitrazepam in germ-free rats.

In anaesthetised bile duct-cannulated rats the overall rate of bile flow was 15-50% lower in both male and female germ-free (GF) rats. Except in the case of amaranth in female GF rats, this was reflected in a lower rate of biliary excretion of the three test xenobiotics, of which two (amaranth and indocyanine green) are excreted unchanged and one (nitrazepam) is excreted solely as metabolites. It was also noted that compared with conventional (CV) rats the relative liver weights (g/kg body weight) were about 20% lower in GF animals. After the intravenous injection of 14C-nitrazepam, thin-layer chromatographic separation of biliary nitrazepam-derived radioactivity revealed three loci (A, B and C in decreasing order of polarity). The relative proportions of A, B and C were similar in GF and CV rats, with C and B being the major and minor "metabolites" respectively. When 14C-nitrazepam was given intragastrically to non-anaesthetised rats, by 9 days about 20% and 70% of the dose had been recovered in the urine and faeces respectively of both GF and CV rats. The rate of elimination of urinary radioactivity was similar in GF and CV rats. However, faecal elimination was much slower in GF animals, for example after 24 hr the respective amounts of radioactivity excreted in GF and CV rats corresponded to 13% and 52% of the dose. These findings indicate that the indigenous bacterial population of an animal may indirectly affect the disposition of a xenobiotic whether or not it is metabolised by the bacteria.

Amaranth Dye↗

A strain dependent sex difference in ouabain-induced cardiotoxicity in rats.

Male rats of the BDIX strain were about twice as sensitive to the lethal effects of intravenously infused ouabain than were their female counterparts. This sex difference in ouabain sensitivity was not exhibited by rats of the Wistar strain. In bile duct-cannulated animals, ouabain biliary excretion was much faster in female BDIX rats. This finding could partly explain the greater ouabain resistance, although certain aspects of the cardiac/plasma ouabain concentration data did suggest that there may have been a component of the sex-related resistance that was not explicable on a pharmacokinetic basis. The faster ouabain biliary excretion in female rats could also partly explain the fact that for similar rates of infusion, the plasma ouabain concentration during infusion was similar in both sexes, despite the body size of the female rats being about one-third smaller.

Animals↗

Influence of potential virulence determinants on Bordetella bronchiseptica-induced ciliostasis.

Eighteen strains of Bordetella bronchiseptica, selected on the basis of previously determined phenotypic characteristics, were examined for their ability to induce ciliostasis in canine tracheal outgrowth cultures. Fifteen strains grown on brucella agar caused ciliostasis. Strains that did not cause ciliostasis were stable, nonpiliated, and nonhemolytic, they did not produce extracellular adenylate cyclase, and were morphologically indistinguishable from rough-phase variants on brucella agar. Plasmids were detected in only five of the strains which induced ciliostasis, transfer of plasmids from four of these strains to one which did not induce ciliostasis did not alter its virulence or colony morphology. All strains which were hemolytic on Bordet-Gengou agar produced extracellular adenylate cyclase. Two nonhemolytic strains, one which produced only rough colonies on brucella agar, also induced ciliostasis. Two types of colony (phase) variation were observed: one recognizable on both brucella agar and Bordet-Gengou agar at frequencies of less than or equal to 10(-2), associated with multiple loss of virulence determinants, and the other recognizable only on Bordet-Gengou agar at frequencies of greater than or equal to 10(-2), associated with flagellum expression. The possession of readily detectable somatic pili was the only phenotypic characteristic consistently associated with the ability to induce ciliostasis. Formalin-killed and chloramphenicol-inhibited B. bronchiseptica strain 110H organisms had detectable pili and attached to cilia, but did not cause ciliostasis. Protease-treated B. bronchiseptica strain 110H organisms did not have detectable pili and in the presence of chloramphenicol did not attach to cilia. Attachment to cilia, although not in itself sufficient to cause ciliostasis, is intimately associated with and may be required for the induction of ciliostasis by B. bronchiseptica strains.

Adenylyl Cyclases↗

Mechanisms for the effects of acetylcholine on sodium transport in frog skin.

In frog skin (Rana temporaria) acetylcholine applied to the serosal surface produces either a sustained inhibiton or sustained stimulation of short-circuit current (SCC). The former effect is accompanied by a reduction and the latter by an increase in total tissue conductance. Both effects of acetylcholine can be accounted for, within experimental error, by changes in net sodium flux across the tissue. By use of selective agonists and antagonists it is concluded that acetylcholine interacts with muscarinic receptors in the serosal membrane. The effects of cholinoceptor agents are also seen with isolated epithelium. The stimulatory effect of acetylcholine is potentiated by theophylline and blocked by inhibitors of prostaglandin synthetase and by mepacrine. It is suggested that acetylcholine stimulates transport by liberating prostaglandins which may then activate adenylcyclase. The inhibitory effect of acetylcholine is correlated with a reduction in cyclic AMP content of the epithelium. Calcium appears to be an important determinant of the type of response seen eith acetylcholine, but the mechanism is not known.

Acetylcholine↗

Increase in epithelial cyclic adenosine 3',5'-monophosphate following vanadate.

Vanadate increases the cyclic adenosine 3',5'-monophosphate (cyclic AMP) content of frog skin epithelium and apparently antagonizes the stimulation by isoprenaline. The effect appears to be a direct activation of adenyl cyclase. This new effect of vanadate together with the inhibitory effects on Na-K ATPase may explain the irregular effects on sodium transport.

Animals↗

Tibial tubercle transfer: a long-range follow-up study.

The prime indications for tibial tubercle transfer are 2 or more complete patellar dislocations with trivial trauma or recurrent subluxation with or without pain causing "giving way." A high "Q" angle, flat lateral condyle, aplastic patella or positive apprehension test may be associated but are not always prime indications in surgery. Methods of fixation are of individual preference in this series and a single screw sufficed. An arthrotomy is not always necessary but is suggested if indicated. If the proximal tibial epiphysis is open, corrective measures are suggested that do not involve the extension of the proximal tibial epiphysis into the tibial tubercle. The tubercle should be advanced to compensate for patella alta and lined up with the femoral shaft. Transplantation of the tubercle medially 3/4'' and distally 1/2'' was generally satisfactory in a series of 377 operations with an average follow up of 3 1/2 years.

Adolescent↗

Autoradiography: technique for drastic reduction of exposure time to alpha particles.

High-speed, gross, alpha autoradiographs can be made if silver-activated zinc sulfide is used as an intensifier in conjunction with high-speed film. The intensifier is interposed between the sample and film. This technique requires about 1/1000 of the exposure time required with Kodak NTB plates. The gross autoradiographs have greater contrast but slightly less resolution than conventional plates.

Animals↗

Evidence of hypertriglyceridemia in managing HIV patients on efavirenz.

Of the recently approved antiretroviral agents, efavirenz has become a popular medication for the treatment of HIV infection. The efficacy of an efavirenz-based regimen has allowed the use of a combination of this medication with other antiretroviral agents in all levels of HIV disease, resulting in decreased viral replication and positive clinical results. Efavirenz is also proposed as an acceptable agent to switch to from a protease inhibitor-based regimen to reduce the risk of metabolic complications. In addition, the favorable side-effect profile, diminished pill burden for clients, and daily dosing have contributed to its popularity. Primary care practitioners should be cognizant of the possible side-effect profile of antiretroviral therapy combinations and enter into a collaborative relationship with the infectious disease clinician to ensure safe and effective patient care.

Alkynes↗

Gadolinium chloride toxicity in the rat.

Groups of 10 male and 10 female Sprague-Dawley rats were given a single intravenous injection of gadolinium chloride solution at dosages of 0 (saline vehicle), 0.07, 0.14, and 0.35 mmol/kg. Apart from 1 top-dose female, which died during dosing, 5 rats/sex/ group were necropsied 48 hr postdose, and the remaining 5 rats/sex/group were necropsied 14 days postdose. Macroscopic, hematological, and clinical chemistry analyses were undertaken on all animals that were necropsied. Histopathological examination was undertaken on all organs from high-dose and control animals necropsied 48 hr postdose and on tissues that showed treatment-related changes from all other rats necropsied either 48 hr or 14 days postdose. Major lesions related to gadolinium chloride administration consisted of mineral deposition in capillary beds (particularly lung and kidney), phagocytosis of mineral by the mononuclear phagocytic system, hepatocellular and splenic necrosis followed by dystrophic mineralization, mineralization of the fundic glandular mucosa in the absence of necrosis followed by mucous cell hyperplasia, decreased platelet numbers and increased prothrombin time, and activated partial thromboplastin time. Electron microscopy and x-ray microanalysis of the spleen and liver revealed electron-dense deposits in splenic macrophages, Kupffer cells, and hepatocytes composed of gadolinium, calcium, and phosphate.

Adrenal Glands↗

Women and hospice care.

The hospice movement has grown extensively in the last ten years. This article examines the role of women in hospice, components of hospice care and a profile of 544 admissions to an inpatient hospice unit over a five year period. Case studies are given to illustrate the needs of women in hospice. Regulatory processes facing hospice programs today are reviewed.

Adult↗