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Biomedical subjects

A Thomas

Publications and source records attributed to A Thomas.

At least 19 recordsLinked to original sources

Vero cytotoxin-producing Escherichia coli O 157 in the United Kingdom.

A total of 226 cultures of Vero cytotoxin-producing Escherichia coli O 157 isolated from humans was received by the PHLS Laboratory of Enteric Pathogens during the six month period January to June 1992. A record monthly total of 122 isolates was received in June. Ten phage types (PT) were identified during this period; PT 2 (45%) and PT 49 (21%) predominated. In addition, 27 human sera with antibodies to E. coli O 157 lipopolysaccharide (LPS) were examined from other cases during this period, making a total of 253 cases of infection associated with E. coli O 157.

Bacterial Toxins

Body size perception and body satisfaction in restrained and unrestrained eaters.

In 21 restrained and 20 unrestrained eaters body size perception was measured using the video distortion technique (VDT), the image marking procedure (IMP) and the kinesthetic size estimating apparatus (KSEA). Body satisfaction was assessed by questionnaires (Body Shape Questionnaire, Dieting scale of the Eating Attitudes Test). Restrained eaters showed no systematic over- or underestimation of the body size but less perceptual accuracy (in VDT and KSEA). Furthermore, they were clearly more dissatisfied with their bodies than unrestrained eaters. Both findings were unrelated to each other. In both groups depressive mood or thoughts seemed to be associated with body dissatisfaction but not with body size misperception. Objective body measures (body mass index, body fat content) were not related to either body size perception or body satisfaction. The findings suggest that a perceptual uncertainty in regard to body size (either for visual or for somatosensory aspects) has already developed in restrained eaters, which may constitute a predisposition for more overt forms of body size misperception as found in eating disorder patients.

Behavior Therapy

Percutaneous lung aspiration biopsy: a comparison between two fine needles.

Fine needle lung aspiration biopsy is now a well established method of obtaining tissue for histopathological diagnosis. It is fast, simple and reliable, and has a very low complication rate. We report our experience using two fine needles, the Turner and the EZ-EM Cut-Biopsy needles, comparing their yield and complication rates. We found that both needles had comparable diagnostic yields (65% with the Turner, and 71% with the EZ-EM) and complication rates. We also found that in most cases, aspirates alone were sufficient for diagnosis, and that obtaining tissue cores with larger bore EZ-EM needles did not significantly influence the diagnostic outcome. We conclude that both the Turner and the EZ-EM needles are equally effective and safe in percutaneous lung aspiration biopsy. The least traumatic needle should be used except when the cytological diagnosis is nonspecific inflammatory cells or inadequate, in which case a repeat with a cutting needle is advised to obtain a core of tissue.

Biopsy, Needle

Evaluation of a Salmonella-specific DNA probe by colony hybridization using non-isotopic and isotopic labeling.

A 2.3 kilobase (kb) Salmonella probe, JEO402-1, and two subfragments, F1214 (1.3 kb) and F1217 (0.8 kb), have been evaluated by colony hybridization using pure cultures of Salmonella serovars and non-salmonella bacteria. JEO402-1, and its subfragments, F1214 and F1217, hybridized to all of 156 different Salmonella serovars tested, while there was no reaction to 112 non-salmonella strains belonging to 19 genera and 37 species of Enterobacteriaceae. Together with previously published results, the JEO402-1 probe has now been shown to detect a total of 396 Salmonella strains belonging to 214 serovars of Salmonella subspecies I-VI. A total of 178 non-salmonella strains representing 23 genera and 51 species of Enterobacteriaceae have all tested negative with JEO402-1. The hybridization results obtained using a digoxigenin-labeled probe were similar to those obtained with 35S isotopic labeling when complete colony lysis was ensured.

Bacterial Typing Techniques

Assessment of function, perfusion, metabolism, and histology in hearts preserved with University of Wisconsin solution.

BACKGROUND: University of Wisconsin solution has shown promise for prolonged cardiac preservation. This study compared the effects of 24-hour cold storage and perfusion preservation techniques by assessment of function, perfusion, metabolism, and histological changes. METHODS AND RESULTS: Three groups of rabbit hearts (n = 6 each) were evaluated: 1) control with immediate reperfusion, 2) continuous perfusion preservation, and 3) cold storage. Hearts were reperfused for 30 minutes, and left ventricular systolic pressure (LVSP) was measured by isovolumetric balloon (LVEDP, 20 mm Hg). We used 201Tl to assess perfusion and 14C-acetate to assess metabolism by macroautoradiography. LVSP was similar for controls and hearts preserved with continuous perfusion (134.8 +/- 2.1 versus 112.2 +/- 6.0 mm Hg, respectively). Hearts preserved with cold storage techniques were significantly worse (36.7 +/- 6.0 versus 134.4 +/- 8.2 mm Hg, p < 0.001). Controls showed homogeneous perfusion and metabolism, whereas hearts in the continuous perfusion group showed mild hypoperfusion and histological damage (26.4 +/- 2.7% of left ventricular cross section). Hearts in the cold storage group had 51.7 +/- 1.2% of the left ventricle hypoperfused and damaged. Histology in the control group was normal; in the perfused group, there were only mild changes; and in the cold storage group, there were extensive derangements of cellular architecture. CONCLUSIONS: Continuous perfusion of the heart with 4 degrees C modified University of Wisconsin solution provided function comparable to that of control. Conversely, cold storage showed extremely poor return of function. Autoradiography confirmed mild perfusion and metabolism abnormalities in control and continuous perfusion hearts, whereas there was marked derangement of cellular architecture, perfusion, and metabolism in the cold storage hearts.

Adenosine

A restaurant-associated outbreak of E. coli O157 infection.

An outbreak of haemorrhagic colitis due to Escherichia coli O157 and associated with a restaurant in Lothian, occurred in September 1990. There were 16 symptomatic cases, four of whom (all children) required dialysis. Notable features of the outbreak were the wide range of incubation periods (1-14 days), the occurrence of secondary spread through asymptomatic carriers and the prolonged period (at least seven days) during which the restaurant appears to have been the source of infection. Despite careful investigation, no single source within the restaurant was identified. The implications for public health are discussed.

Adult

Control of oral anticoagulation in patients using long-term internal jugular catheters for haemodialysis access.

Patients using long-term double-lumen silastic jugular catheters for haemodialysis access frequently require oral anticoagulants to maintain patency of the catheter. It may be difficult or impossible to obtain peripheral vein blood samples for PT measurements to regulate the oral anticoagulant dose. Our studies have shown that removal of 3 mls of blood from the catheter limb containing the heparin (to be discarded) followed by 10 mls as a heparin wash-out (to be returned to the patient) allows blood to be taken from the arterial limb of the catheter for PT measurement. The PT measurement obtained from the arterial limb after a 10 ml wash-out is nearly always identical with the PT measurement on blood obtained from a peripheral vein. If the simultaneously measured aPTT is normal the PT is predictably and consistently accurate. If the aPTT is raised due to traces of residual heparin then the PT may be inaccurate and should be repeated. This method is easy and reliable and can be recommended as an aid to regulation of the oral anticoagulant dose.

Anticoagulants

A comparison of the initiation factors of eukaryotic protein synthesis from ribosomes and from the postribosomal supernatant.

A purification procedure is described for the initiation factors of protein synthesis from rabbit reticulocytes: (a) from the ribosomal wash and (b) from the postribosomal supernantant. A comparison is made between these preparations with respect to yield and specific activity. eIF-4A and eIF-4D occur mainly in the postribosomal supernatant; eIF-2, eIF-4C and eIF-5 are more evenly divided over both fractions, whereas eIF-1, eIF-3 and eIF-4B are found almost exclusively in the ribosomal wash. No significant difference in specific activity could be detected when factors from both sources were compared, with a possible exception of eIF-4A and eIF-4D.

Animals

Adrenocorticotrophin-related peptides in adult and foetal sheep pituitary glands.

Differences in foetal and adult adrenal function may be due to qualitative as well as quantitative changes in the pituitary corticotrophic stimulus. Pituitary glands from adult and foetal sheep were freshly dissected and stored at -70 degrees C until extracted at pH 1.5. The extracts were subjected to chromatography on Sephadex G-100 superfine and fractions were assayed by multiple radioimmunoassays directed against the NH2- and CO2H-terminal sequences of ACTH and lipotrophin (LPH). Peaks corresponding to beta-melanocyte-stimulating hormone (beta-MSH), beta-LHP, gamma-LPH, beta-endorphin and ACTH were identified, with little or no evidence for the presence of alpha-MSH and corticotrophin-like intermediate lobe peptide. Three peaks of large molecular weight material, A. B and C, were identified and their relative proportions shown to be considerably greater in the foetus than in the adult. The immunoassay profile of peaks A and B suggested that they were 'stem hormones' which could give rise to a family of biologically active peptides. Since the 'family tree' which they engender varies according to the stage of development, it is proposed that the changes in the 'trophic family' may explain the different adrenal responses of the foetal and adult sheep.

Adrenocorticotropic Hormone

Aerobic and anaerobic bacterial flora in semen from fertile and infertile groups of men.

Semen samples were collected by masturbation under asceptic conditions from men who had sired children within the past 6 mo (group A) and asymptomatic men attending an infertility clinic who had not sired children and whose wives were asymptomatic for infertility (group B). These 109 semen samples were analyzed and cultured for isolation of aerobic and anerobic organisms. Overall, 68% of the specimens had positive bacterial cultures: 54% of the samples from group A were positive and 73% from group B were positive. Mixed bacterial flora were isolated from both groups but in group B they were more varied and present in a higher colony count than in group A. Staphylococcus epidermidis, Staph. aureus, Corynebacterium species, Mycoplasma hominis, and Ureaplasma urealyticum were isolated from group A. Group B revealed these organisma plus Streptococcus pneumoniae type III, Strep. pyogenes group A, Strep. feacalis, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Candida albicans, Bacteroides species, Peptostreptococcus species, and Eubacterium species. Semen samples from group A were of better quality than those from group B. In addition, the antibacterial effect of seminal plasma from group A was greater than that from group B.

Adult