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Biomedical subjects

A Smith

Publications and source records attributed to A Smith.

At least 1,045 records · Page 58Linked to original sources

Explaining variation in general practitioner referrals to hospital.

Reported rates of referral by individual general practitioners to hospitals range from less than 1% of all consultations to more than 20%. Research on variations in rates of referral by general practitioners in the UK is reviewed here. Studies have largely failed to account for variation either in terms of differences in the characteristics of patients or differences in the doctors and their practices. It is argued that this failure arises because most studies do not distinguish between different types of referral or reasons for making a referral. In order to begin to explain variations it is necessary to identify the stages in the complex process of decision making. A theoretical model of the referral decision is advanced, which is intended to provide a framework for further research on the referral process.

Decision Making↗

Incidence and mechanism of neutropenia and thrombocytopenia in patients with human immunodeficiency virus infection.

The incidence of lymphopenia, thrombocytopenia and neutropenia was studied in 105 homosexual men with HIV infection. Lymphopenia was common in patients with AIDS (75%), but its incidence in PGL (24%) was not significantly different from that in asymptomatic anti-HIV positive (15%) homosexual men. Neutropenia and thrombocytopenia were found in patients with AIDS or PGL, but not in asymptomatic anti-HIV positive homosexuals. The study suggests that the neutropenia and thrombocytopenia in these patients were due to autoimmune destruction of neutrophils and platelets.

Acquired Immunodeficiency Syndrome↗

Albumin microspheres for intra-articular drug delivery: investigation of their retention in normal and arthritic knee joints of rabbits.

The retention of 131I-labelled albumin microspheres and microsphere-entrapped [131I]rose bengal was investigated in normal and experimentally arthritic knee joints of rabbits. Albumin microspheres were cleared slowly from the joint cavity and no significant difference was observed between normal and inflamed joints. Entrapment of rose bengal within albumin microspheres was found to delay the clearance of the drug from the joint when compared with a solution of rose bengal. In addition, the retention time for entrapped rose bengal was dependent on the degree of inflammation present.

Albumins↗

Increased ATPase acid stability in type 1 fibers of rat soleus.

Type 1 fibers in skeletal muscle have been considered homogeneous on the basis of their acid-resistant ATPase activity. We have found that the Type 1 fibers in rat soleus are more resistant to prolonged acid pre-incubation than are those in other muscles.

Acids↗

Thyroidectomy significantly alters carbonic anhydrase III concentration and fiber distribution in rat muscle.

Thyroidectomy has a dramatic effect on rat muscle, greatly increasing the number of Type I fibers and the concentrations of carbonic anhydrase III (CAIII) in the muscle. Carbonic anhydrase III is not confined to the Type I fibers, as was previously believed, but also occurs in fibers that exhibit a level of ATPase staining less than that of 2A fibers but greater than 2B. These fibers are rare in normal muscle but become numerous after thyroidectomy, when they stain heavily for CAIII.

Adenosine Triphosphatases↗

Pulmonary cryptosporidiosis occurring in a bone marrow transplant patient.

We describe what is believed to be the first bone marrow transplant patient, a 32-year-old man, in whom pulmonary cryptosporidiosis was associated with terminal respiratory failure. The diagnosis, treatment and postmortem histology are discussed together with a brief review of the literature.

Adult↗

S-antigen: characterization of a pathogenic epitope which mediates experimental autoimmune uveitis and pinealitis in Lewis rats.

S-antigen (48K protein) is a photoreceptor cell protein highly pathogenic for the induction of experimental autoimmune uveitis (EAU) and intimately involved in the visual process. EAU is characterized, in part, as a T-cell mediated autoimmune disease which results in a severe inflammation of the uveal tract, and pineal gland. In order to determine specific sites in S-antigen responsible for its pathogenicity we synthesized twenty-three peptides, corresponding to the entire 404 amino acid sequence, and tested each peptide for its ability to induce EAU in Lewis rats. One peptide, peptide M (18 amino acids in length), was found to be highly pathogenic and consistently induced an EAU that was identical to the disease caused by native S-antigen. Clinically, the disease that developed in the eye was characterized by iris and pericorneal hyperemia, followed by inflammatory exudates in the anterior and vitreous chambers. Histopathologically a severe inflammatory response was observed which resulted in the complete destruction of the photoreceptor cell layer of the retina. In order to more fully characterize this pathogenic site, 14 additional smaller peptides (eight to eighteen amino acids in length) corresponding to the left and right portions of peptide M were synthesized. Of these peptides, peptide M16L, M15L, and M12L induced EAU, further localizing this pathogenic site to a small well-characterized region of S-antigen consisting of twelve amino acids. In addition, animals with ocular inflammatory disease had an associated pinealitis characterized by a lymphocytic infiltration of the subcapsular and central area of the pineal gland. The significance of these findings and the relationship of S-antigen in the pathogenesis of EAU and other autoimmune diseases is discussed.

Amino Acid Sequence↗

A bridge over troubled waters: an innovative day-treatment program for older adolescents.

An innovative day-treatment program designed to reduce the likelihood that severely disturbed, older adolescents will become chronically ill young adults is described and clinical vignettes are presented which illustrate the program's effectiveness in facilitating educational achievement and enhanced social functioning among patients with significant histories of hospitalization and substance abuse.

Adolescent↗

Esophagogastric anastomosis performed with a stapler: the occurrence of leakage and stricture.

The circular stapler has lowered the leakage rate of an esophageal anastomosis to a level hitherto achieved by only a few surgeons performing hand anastomosis on selected patients with carcinoma of the esophagus. However, the esophageal anastomosis performed with a stapler is also associated with a high stricture rate. Our prospective study was conducted to determine the leakage rate and the incidence of stricture after esophagogastric anastomosis was performed with a stapler, the relationship of stricture to the size of the stapler, and the risk of stricture in relation to time. In a group of 174 patients with carcinoma of the thoracic esophagus, resection was performed, and a one-stage esophagogastric anastomosis was constructed. There were 33 hand anastomoses, 64 anastomoses with an EEA stapler (U.S. Surgical Corp., Norwalk, Conn.), and 77 anastomoses with an ILS stapler (Ethicon Ltd., Edinburgh, U.K.). The anastomotic leakage rate was 3.4% (6/174); 3% with the hand technique and 3.5% with the stapler technique (4.7% for the EEA and 2.6% for the ILS). After leakages and hospital deaths were excluded, 133 discharged patients were evaluated for the occurrence of anastomotic strictures. Only those who complained of dysphagia were investigated. The incidence of stricture for hand anastomosis was 8.7%-EEA 20% and ILS 10%; the overall incidence of anastomoses with a stapler was 14.5%. The true incidence would probably be higher if all patients were assessed by endoscopic or radiologic examination after operation. All three sizes of EEA staplers had a high incidence of stricture. For the ILS stapler the 25 mm size had the highest stricture rate (28.6%) of all groups, but for the 29 and 33 mm sizes, the incidences were 5.3% and 0%, respectively. Actuarial analysis showed an increasing risk of stricture with a reduction in the size of stapler used and was 32.5% and 35%, respectively, for the ILS 25 mm and EEA 25 mm staplers at 131/2 months. The risk of stricture occurrence was highest in the first 4 months. Treatment by bougienage was satisfactory. In conclusion, esophagogastric anastomosis performed with a stapler is a very safe procedure with respect to leakage but is associated with a high risk of stricture, except when the largest ILS staplers are used. However, dilatation readily overcomes the stricture occurrence and adequately compensates for the reduced leakage rate and its attendant serious consequences.

Esophageal Neoplasms↗

Retrovirus infections among patients treated in Britain with various clotting factors.

At the end of 1984 a collaborative survey was carried out to determine the prevalence of infection with human T cell lymphotropic virus type III/lymphadenopathy associated virus (HTLV-III/LAV) and HTLV-I among 584 recipients of various blood products in Britain at that time. In 204 cases yearly point prevalence figures for infection were also obtained for 1978 to 1983. In 1984, 215 of 315 patients (68%) who had received commercial concentrate for haemophilia A were identified as positive for anti-HTLV-III/LAV as compared with only 18 of 166 patients (11%) given British concentrate alone for this disease. This difference was further emphasised by the yearly point prevalence rates: seroconversion began in 1980 among recipients of commercial concentrate, but not until 1983 did such an instance occur among recipients of British concentrate. Any conclusions must remain speculative, but possibly seropositivity among haemophiliacs may not carry so grave a prognosis as previously thought.

Blood Coagulation Factors↗

Chronic inflammatory bowel disease, cigarette smoking, and use of oral contraceptives: findings in a large cohort study of women of childbearing age.

Since the start in 1968 of the Oxford Family Planning Association contraceptive study 31 women have developed ulcerative colitis and 18 have developed Crohn's disease, giving incidences of 0.15 and 0.09/1000 woman years respectively. The incidence of ulcerative colitis in women who were non-smokers on entry to the study was 0.17/1000 woman years and the incidence in smokers was 0.11/1000 woman years. The findings for Crohn's disease were entirely different, the corresponding incidences being 0.05 and 0.17/1000 woman years respectively. Both ulcerative colitis and Crohn's disease were more common among women currently using oral contraceptives than among those not doing so. Incidences per 1000 woman years for ulcerative colitis were 0.26 in users and 0.11 in non-users; for Crohn's disease the incidences were 0.13 and 0.07 respectively. Though the association between the use of oral contraceptives and chronic inflammatory bowel disease cannot be regarded as established, the effects of smoking have been shown consistently in many studies. This observation provides an important clue to the aetiology of chronic inflammatory bowel disease.

Adult↗

Two apparent Philadelphia chromosomes arising from translocations with different chromosomes in a patient with CML: 46,XY,t(7;22)(p22;q11),t(9;22)(q34;q11).

Chromosome studies on bone marrow cells and unstimulated peripheral lymphocytes from a patient with chronic myelogenous leukemia revealed the presence in all cells of two apparent Philadelphia chromosomes: one resulting from the classical translocation with a chromosome #9, and the other arising from a translocation between chromosomes #22 and #7. There was no normal chromosome #22. Some of the cells also had an i(17q), indicative of blast crisis. Repeated chromosome studies at different times during the course of the disease revealed the evolution of additional karyotypic changes. All cells from later samples had an extra #8; some of these cells had a third Philadelphia chromosome, whereas, others had a second Y chromosome. Although a few normal cells were seen in PHA-stimulated lymphocyte cultures, indicating that the patient has a normal constitutional karyotype, most of the cells had a karyotype identical to that found in unstimulated cultures. This unusual karyotype, 46,XY,t(7;22)(p22;q11),t(9;22)(q34;q11), represents the first case in which two apparent Philadelphia chromosomes are present in the leukemic cells from a patient in the absence of a normal #22 chromosome.

Chromosome Banding↗