Multilobulated, multinucleated multiple myeloma.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to M Short.
Explore the source record for details and available documents.
Typhoid fever caused by Salmonella typhi remains endemic to many parts of South Africa, including Natal and KwaZulu, Northern Transvaal and the Transkei. Until recently, the majority of S. typhi isolates from South Africa have remained susceptible to ampicillin/amoxycillin and chloramphenicol, and only three cases of typhoid due to multi-antibiotic resistant strains of S. typhi have been documented. Ampicillin/amoxycillin and chloramphenicol are, therefore, still recommended as first line therapy for patients with typhoid fever in this country. We describe a cluster of six cases of typhoid caused by S. typhi that was resistant to ampicillin, chloramphenicol and trimethoprim-sulphamethoxazole. All these patients presented over a 3-month period; the patients were from three adjacent districts in the Northern Natal area of South Africa. The high rate of intestinal perforation (two of six) was a direct consequence of inappropriate antibiotic treatment. Failure of surgical intervention, renal impairment as well as delay in starting appropriate antibiotic treatment were factors contributing to the high mortality (three of six). The good clinical outcome in the remaining three patients probably resulted from treatment with appropriate antibiotics; however, mild disease in two of these patients may have been a contributing factor. All isolates showed high minimal inhibitory concentrations (MIC) of greater than or equal to 256 micrograms/ml to ampicillin, chloramphenicol and trimethoprim-sulphamethoxazole. The isolates were all highly sensitive to the third generation cephalosporins (MIC less than or equal to 0.06 micrograms/ml) and quinolones (MIC less than or equal to 0.03 micrograms/ml). Conjugation studies suggest a genetic transfer of resistance, probably plasmid mediated. The presence of beta-lactamase and chloramphenicol acetyl transferase enzymes in all six isolates tested would account for the resistance to ampicillin and chloramphenicol respectively. The transfer of such plasmids to erstwhile sensitive strains could conceivably occur in this typhoid-endemic area, where sanitary conditions are poor and living conditions crowded, thus further exacerbating the problem. It is recommended that in areas where such multiresistant strains are encountered, the third generation cephalosporins or quinolones be used as empiric therapy for typhoid fever.
This study has investigated two of the main problems with radiolabelled antibody imaging, the formation of circulating immune complexes (I.C.) and the non specific binding of radiolabel to the antibody molecule. Patients undergoing immunoscintigraphy with 111In labelled monoclonal antibody ICR2 were divided into three groups who received either the radiolabelled antibody alone (control, n = 12), the radiolabelled antibody which was incubated with the chelating agent diethylene triamine pentacetic acid (DTPA) prior to size exclusion chromatography (n = 6) or whose injectate was treated with DTPA and cold MAb administered intravenously prior to radiolabelled MAb administration (n = 6). Radiolabelled antibody uptake in abdominal organs was measured by region of interest analysis using a gamma camera with online computer and that in tumour and normal tissues by gamma well counting of biopsies. Circulating antigen and immune complex was measured by high pressure liquid chromatography (HPLC). The sensitivity of tumour imaging and the tumour uptake of radiolabelled antibody was not significantly different between the groups. Patients with high circulating antigen levels developed high levels of circulating immune complex but also had high tumour uptakes of radiolabelled antibody. Administration of cold MAb increased the splenic, but did not effect the tumour uptake of radiolabelled antibody and only minimally reduced levels of circulating immune complex. Chelate administration reduced the urinary excretion of radioactivity but increased the liver uptake of radioactivity. These results have shown that successful antibody imaging can be carried out despite high levels of circulating antigen, that large doses of unlabelled antibody are required to prevent immune complex formation and that removal of non specifically bound 111In does not reduce the liver uptake of radioactivity.
The prevalence, natural history, and genetic characteristics of simian immunodeficiency virus (SIV) infections in most feral African monkey species are presently unknown, yet this information is essential to elucidate their origin and relationship to other simian and human immunodeficiency viruses. In this study, a combination of classical and molecular approaches were used to identify and characterize SIV isolates from West African green monkeys (Cercopithecus sabaeus) (SIVagm isolates). Four SIVagm viruses from wild-caught West African green monkeys were isolated and analyzed biologically and molecularly. Amplification, cloning, and sequencing of a 279-bp polymerase fragment directly from uncultured peripheral blood mononuclear cells was facilitated by the use of nested polymerase chain reaction. The results indicated that West African green monkeys are naturally infected with SIVs which are closely related to East African SIVagm isolates. However, structural, antigenic, and genetic differences were observed which strongly suggest that the West African green monkey viruses comprise a phylogenetically distinct subgroup of SIVagm. These findings support our previous hypothesis that SIVagm viruses may have evolved and diverged coincident with the evolution and divergence of their African green monkey host. In addition, this study describes a polymerase chain reaction-based approach that allows the identification and molecular analysis of divergent SIV strains directly from primary monkey tissue. This approach, which does not depend on virus isolation methods, should facilitate future studies aimed at elucidating the origins and natural history of SIVs in feral African green monkey populations.
The lung dose and deposition patterns of drug delivered by dry powder inhaler are not known. The effects of inhaling 400 micrograms salbutamol delivered by dry powder inhaler (two 200 micrograms salbutamol Rotacaps), by pressurised metered dose inhaler, and by Acorn nebuliser were studied in nine subjects with chronic stable asthma. Technetium-99m labelled Teflon particles were mixed with micronised salbutamol in the pressurised metered dose inhaler and in the capsules; technetium-99m labelled human serum albumin was mixed with the salbutamol solution for the nebuliser study. The pressurised metered dose inhaler deposited 11.2% (SEM 0.8%) of the dose within the lungs; this was significantly more than the dose deposited by the dry powder inhaler (9.1% (0.6%], but did not differ significantly from the dose delivered by the nebuliser (9.9% (0.7%]. Distribution within the peripheral third of the lung was significantly greater with the nebuliser than with the other two systems; FEV1 improved to a significantly greater extent after inhalation of 400 micrograms salbutamol from the pressurised metered dose inhaler (35.6% from baseline) than from the nebuliser (25.8%) or dry powder inhaler (25.2%). Thus after inhalation of similar doses of salbutamol a larger proportion of drug was deposited within the lungs when it was inhaled from a metered dose inhaler than from a dry powder system; the nebuliser achieved the greatest peripheral deposition. The bronchodilator response seems to depend on the amount of drug within the lungs rather than its pattern of distribution.
Explore the source record for details and available documents.
The influence of breathing pattern on lung deposition and bronchodilator response to nebulised salbutamol is uncertain. Three different breathing patterns were assessed in eight patients with chronic stable asthma. Salbutamol solution (2.5 mg in 4 ml) mixed with technetium-99m labelled human serum albumin was nebulised by an Acorn nebuliser at a flow rate of 6 litres a minute. Particles with a mass median aerodynamic diameter of 4.8 microns were produced for inhalation by (a) tidal breathing, (b) six tidal breaths followed by three deep breaths, and (c) six tidal breaths followed by three deep breaths with a five second breath hold after each breath. Each breathing pattern was continued for four minutes. There was no significant difference in the percentage of radioaerosol deposited in the lung or in the distribution of radioaerosol within the lung as assessed by gamma camera imaging. Changes in bronchodilator responses as measured by peak expiratory flow rate (PEF), forced expiratory volume in one second (FEV1), and forced vital capacity (FVC) 30, 45, and 60 minutes after inhalation were similar for the three studies. The mean (SEM) maximum percentage change in FEV1 was 44 (7.1), 47 (9.2), and 51 (8.4) for studies 1, 2, and 3 respectively. The percentage of nebulised solution deposited in the body was also similar for the three breathing patterns--that is, 11-13%, of which 98% entered the lung. This study shows that inhaling a nebulised aerosol by tidal breathing, the simplest method, is as effective as tidal breathing with deep breaths with or without a breath hold.
The particle size of bronchodilator aerosols may be important in determining the site of deposition in the lung and their therapeutic effect. The distribution of aerosols (labelled with technetium-99m diethylene triamine pentacetic acid) of two different particle sizes has been studied by gamma camera imaging. The particles had mass median aerodynamic diameters (geometric standard deviations) of 1.4 (1.4) and 5.5 (2.3) micron, and they were administered from a jet nebuliser to eight patients with chronic severe stable asthma. There was no significant difference in peripheral lung deposition with the two aerosols in any patient. The bronchodilator effect of the two aerosols was determined from cumulative dose-response studies. To avoid large doses that might mask possible differences in effect due to aerosol size, small, precisely determined incremental amounts of salbutamol (25-250 micrograms total lung dose) were used. The two doses were given via a nebuliser on separate occasions and the bronchodilator response was measured from FEV1, forced vital capacity, and peak expiratory flow 30 minutes after each dose. Bronchodilatation was similar with the two aerosols at each dose of salbutamol. There was therefore no difference in distribution within the lung or any difference in bronchodilator effect between an aerosol of small (1.4 micron) particle size and an aerosol of 5.5 microns in patients with severe but stable asthma.
Interrelationships of selected mechanical and biochemical properties of hindlimb extensor muscles following low thoracic cord transection were studied. Kittens were spinalized (Sp) at 2 wk and maintained for 6-12 mo. Some Sp animals were exercised (Sp-E) on a treadmill 25-30 min/day, 5 days/wk. In situ contractile properties of the slow-twitch soleus (SOL) and fast-twitch medical gastrocnemius (MG) muscles of normal (N), Sp, and Sp-E cats were determined. Exercise did not affect most parameters; thus Sp and Sp-E groups are considered collectively. The cross-sectional areas (CSA) of the SOL and MG decreased by 43 and 32%, respectively. Specific tension (tension/CSA) was maintained in the SOL but decreased (P less than 0.05) in the MG. Contraction time (CT) and half-relaxation time were significantly shorter in the SOL but unchanged in the MG. Maximum shortening velocity (Vmax) and myosin ATPase (mumol X mg-1 X min-1) increased (P less than 0.05) in the SOL of both groups and the MG of Sp. Frequency-tension responses of both muscles shifted toward that resembling a "faster" muscle. These results substantiate the existence of relatively independent regulatory mechanisms for Vmax and CT and show that myosin ATPase levels are more closely related to Vmax than CT. Although the changes in the SOL were consistent with the hypothesis that slow fibers are converted to fast, the elevated Vmax and myosin ATPase of the MG suggest that significant changes also occur within a "fast" fiber-type category.
Previous calibration studies have shown a high interlaboratory variability in the potency of the proposed Office of Biologics (National Center for Drugs and Biologics, US-FDA) AHF standard relative to the 2nd International Standard for Factor VIII (Factor VIII:C) (WHO 73/552). This led to the formation of an Industry Collaborative Study group whose objective was to reduce the assay variability. The group, in collaboration with the Office of Biologics and the National Institute for Biological Standards and Control (UK), designed a study based on a monographed one-stage assay protocol, which specified all materials, assay methods, equipment, dilution technique, reagents, assay order, and calculation methodology. All participants received common reagents and samples, with the exception of substrate plasma. It was felt that substrate plasma could not be a common reagent in a monographed assay. However, each laboratory prepared substrate plasma according to the protocol. All data were analyzed by an independent statistical staff. Preparations assayed included two 10-donor plasma pools, the 2nd International Standard for Factor VIII (WHO 73/552), the proposed OoB Lot A internal standard, the participants' own house standards, and commercial AHF concentrate material. The results show a statistically insignificant reduction in the interlaboratory variability, but intralaboratory consistency was generally maintained. The study shows that monographing an assay for Factor VIII.
The results of a chromosome survey of 3993 liveborn infants, the majority of which have been studied using G-banding, are reported. The frequency of all types of chromosome abnormalities detected was similar to that found in previous newborn surveys, which were carried out on different socio-economic structure, but the incidence of aneuploid chromosome abnormalities was comparable in the two localities.
Explore the source record for details and available documents.