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Biomedical subjects

R Hall

Publications and source records attributed to R Hall.

At least 181 records · Page 10Linked to original sources
PubMed1993

High-dose cytosine arabinoside in chronic lymphocytic leukemia: a clinical and pharmacologic analysis.

Twenty-seven patients with B-cell chronic lymphocytic leukemia (CLL) or a related lymphoid malignancy were treated with high-dose cytosine arabinoside (ara-C) at a dosage of 3 gm/m2 administered over 2 hours every 12 hours at one to four doses per course, which were repeated at 4-week intervals. Median patient age was 60 years. Fifty-four percent of CLL patients had Rai stage III or IV disease and the median number of prior therapies was three. Two patients achieved a complete response, five had a partial response, and two had clinical improvement for an overall response rate of 33%. The median duration of response was 9 months. Myelosuppression and infection were the main toxicities. Intracellular levels of the active metabolite ara-C triphosphate varied among patients, but comparisons of pharmacokinetic parameters revealed no significant differences between responders and non-responders. We conclude that high-dose ara-C has modest activity in CLL and that its use in combination with other agents in the treatment of CLL is warranted.

Aged↗
PubMed1993

A study of medical device packaging.

In his article published in the January/February 1993 issue of Medical Device Technology, the author detailed a comprehensive packaging brief for designers of sterile medical device packaging. This article contains an evaluation of the packaging currently used in the industry, which include pouches, soft formings, and rigid blister packs. The study highlights their advantages and disadvantages and also offers some advice for developing a package that performs as designed.

Disposable Equipment↗
PubMed1992

Smoking-related DNA adducts in human gastric cancers.

DNA was extracted from the tumour tissue of 26 patients (18 smokers, 8 non-smokers) undergoing surgery for gastric cancer, and analyzed for the presence of DNA adducts by the 32P-post-labelling method. Adducts were detected in all samples tested, and adduct levels ranged from 2 adducts/10(8) nucleotides to 60 adducts/10(8) nucleotides. In male subjects, adduct levels were significantly greater in the DNA of smokers than in that of non-smokers. These results support epidemiological data suggesting that smoking is a risk factor for gastric cancer.

Aged↗
PubMed1992

Regulation of gene expression of rat skeletal muscle/liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase. Isolation and characterization of a glucocorticoid response element in the first intron of the gene.

At least two genes encode isoenzymes of rat 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase. Alternative splicing of one of these genes generates a skeletal muscle-specific transcript from an upstream promoter and a liver-specific transcript from a downstream promoter. A potent glucocorticoid response element was identified in the first intron of the gene, i.e. between liver exon I and exon II. The element is approximately 3.5 kilobase pairs (kb) downstream of the liver isoenzyme transcription start site and 13 kb upstream of exon II of the gene and confers dexamethasone-sensitive expression of chloramphenicol acetyltransferase (CAT) activity from a heterologous thymidine kinase promoter and from both homologous 5'-flanking regions of the gene. This glucocorticoid response element also exhibits androgen- but not estrogen-sensitive expression of CAT activity in HeLa cells cotransfected with the appropriate receptor expression vector. DNase footprint and sequence analysis revealed that the element is comprised minimally of two adjacent 15-mer glucocorticoid receptor dimer binding sites situated in opposite orientations. Glucocortcoid regulation of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase gene expression in liver and skeletal muscle is mediated by a single complex glucocorticoid response element located in the first intron of the skeletal muscle/liver gene.

Animals↗
PubMed1992

Association between postpartum thyroid dysfunction and thyroid antibodies and depression.

OBJECTIVE: To define the relation between mood and autoimmune thyroid dysfunction during the eight months after delivery. DESIGN: Double blind comparison of the psychiatric status of women positive and negative for thyroid antibodies. Clinical examination and blood sampling for free triiodothyronine and thyroxine, thyroid stimulating hormone, and thyroid antibody concentrations at four weekly intervals. Psychiatric assessment at six, eight, 12, 20, and 28 weeks post partum. SETTING: Outpatient department of district hospital. PATIENTS: 145 antibody positive women and 229 antibody negative women delivering between August 1987 and December 1989. MAIN OUTCOME MEASURES: Thyroid status. Number of cases of mental ill health by the general health questionnaire, research diagnostic criteria, Hamilton 17 item depression scale, hospital anxiety and depression scale, and Edinburgh postnatal depression scale. RESULTS: Six weeks after delivery the general health questionnaire showed 62 (43%) antibody positive women and 65 (28%) antibody negative women had mental ill health (chi 2 = 8.18, p less than 0.005). Follow up of 110 antibody positive and 132 antibody negative women showed significantly greater depression by research diagnostic criteria in antibody positive women (47%) than antibody negative women (32%) regardless of thyroid dysfunction. Antibody positive women showed higher mean scores for depression on the Hamilton (6.01 v 3.89, p = 0.0002), Edinburgh (7.45 v 5.92, p = 0.031), and hospital depression scales (4.95 v 3.79, p = 0.003). CONCLUSION: Depressive symptoms are associated with positive thyroid antibody status in the postpartum period.

Autoantibodies↗
PubMed1992

Theileria annulata: alterations in phosphoprotein and protein kinase activity profiles of infected leukocytes of the bovine host, Bos taurus.

The phosphoprotein profiles of T. annulata-infected and uninfected leukocyte cell lines were compared by both in vivo and in vitro labeling assays. Three phosphoproteins were unique to T. annulata-infected cells, while a further two were quantitatively increased relative to uninfected cells. In addition, two proteins were present and phosphorylated only in the uninfected cell lines, suggesting either a repression of these proteins or their dephosphorylation upon infection of the host cell by the parasite. In order to determine if alterations in protein kinase activity may be responsible for these differences, as opposed to levels of available substrate, an in situ electrophoretic protein kinase assay was developed. This assay allowed a crude separation of protein kinases and revealed alterations in the protein kinase profile of Theileria-infected cells which reflected the differences observed in phosphoprotein profiles. Two protein kinases were unique to infected cells, a further two were more active in infected cells while one was more active in uninfected cells.

Adenosine Triphosphate↗
PubMed1992

Meningococcal disease in Wales: clinical features, outcome and public health management.

In Wales, in 1988, 119 patients with meningococcal disease were identified, so giving a crude annual incidence of 4.2 patients per 100,000 population. The combined classical clinical features of fever, vomiting, neck stiffness, headache and purpuric rash were identified in only 9% of patients. Fever and vomiting were the commonest symptoms, both being present in 60% of patients. A rash was noted in 77% of patients but neck stiffness in only 39%. Rash was more common in children, headache and photophobia in adults. A total of 13 patients died, the fatality rare increasing with age from 3% in infants to 20% in older teenagers and adults. Only 15% of 75 patients admitted to hospital by general practitioners were known to have received intravenous or intramuscular penicillin before admission as recommended by the Chief Medical Officers of the Health Departments in the U.K. Only 24% of patients received rifampicin to clear nasopharyngeal carriage before or at discharge from hospital. Altogether, 375 household contacts of patients were identified. At least 84% of them received chemoprophylaxis.

Acute Disease↗
PubMed1992

Mimicry of elastin repetitive motifs by Theileria annulata sporozoite surface antigen.

Theileria annulata is an important pathogen of cattle in the tropics. The gene sequence of a sporozoite surface antigen (SPAG-1) is reported. Data is also presented demonstrating that SPAG-1 is synthesised as a large precursor. This antigen, which is a candidate for inclusion in a subunit vaccine, shows a remarkable degree of molecular mimicry to the extracellular matrix protein elastin. It contains both repetitive motifs PGVGV and VGVAPG. Immunofluorescence using a monoclonal antibody against VGVAPG confirmed that this peptide is expressed on sporozoites as predicted. The presence of VGVAPG is particularly interesting since this is the ligand for elastin receptors on a range of cell types, including macrophages/monocytes which are a major class of host target cells. It is proposed that this antigen represents the ligand whereby T. annulata recognises its host cells.

Amino Acid Sequence↗
PubMed1992

The sonographic appearances in postpartum thyroiditis.

During the postpartum period about 50% of women with circulating thyroid autoantibodies develop a transient autoimmune thyroiditis. To determine the sonographic appearances in postpartum thyroiditis (PPT), serial ultrasound (US) scans of the thyroid were performed in 135 postpartum women who were divided into three clinical groups: Group 1, 37 antibody positive subjects who developed PPT; Group 2, 28 antibody positive subjects in whom thyroid function remained normal; Group 3, 70 antibody negative controls. Thyroid hypoechogenicity was observed in 14/31 patients (45%) who were scanned between 4 and 8 weeks postpartum and who subsequently developed PPT (Group 1) compared with 4/24 patients (17%) in Group 2 (P less than 0.05) and 1/65 patients (1.5%) in Group 3 (P less than 0.001). In antibody positive patients, the positive predictive value of an abnormal scan during this period was 78%. Between 15 and 25 weeks postpartum thyroid hypoechogenicity was present in 32/37 patients (86%) in Group 1 compared with 11/28 patients (39%) in Group 2 (P less than 0.001) and 2/70 patients (3%) in Group 3 (P less than 0.001). Sonographic abnormality persisted beyond 32 weeks postpartum in 36/41 antibody positive patients (87%) who had exhibited thyroid hypoechogenicity earlier during the study and who had late scans. The characteristic US appearance in PPT is thyroid hypoechogenicity. The role of sonography in the prediction, diagnosis and follow up of patients with PPT is discussed.

Autoantibodies↗
PubMed1992

Delayed root canal therapy: an analysis of treatment over time.

A retrospective study of 898 teeth receiving root canal therapy was performed to document the sequelae of delayed completion of root canal treatment. Teeth were categorized into a prompt treatment group and a delayed treatment group. Comparisons of prompt and delayed treatment groups were made with regard to preoperative pain, interappointment emergencies, postobturation pain, and final treatment. Findings from this study show that a palliative endodontic procedure is an extremely effective treatment. However, 56% of teeth with incomplete root canal therapy eventually were extracted compared with 2 to 3% for the root canal filling treatment groups. By emphasizing the potential loss of the tooth rather than the potential of interappointment emergencies, the clinician may be more effective in achieving compliance among patients receiving delayed treatment.

Acute Disease↗
PubMed1992

Theileria annulata-infected cells produce abundant proteases whose activity is reduced by long-term cell culture.

Lysates of Theileria annulata-infected bovine lymphoblastoid cells and their uninfected counterparts were tested for protease activity using gelatin substrate SDS-PAGE. The infected cells produced a number of extra activities at pH 8.0 in the presence of Ca2+. Calcium was found to enhance the activities but was not an absolute requirement. Studies using inhibitors, including E64, 3,4-dichloroisocoumarin, pepstatin and 1, 10-phenanthroline suggested that the activities were metalloproteases. We analysed two vaccine lines; the Ode line from India and the Ankara Pendik line from Turkey. In the Ode line the later passage had very much reduced levels of the enzyme activities. In the case of the Ankara Pendik line both stages analysed had very low protease activities, but a reduction from the early to late passage was also observed. The reduction in the level of protease activity was also observed as a gradual process during on-going culture of lines derived from the Hissar and Ode stocks. In the Ode line we demonstrated a parallel decrease in the production of microschizonts upon temperature shift in vitro.

Animals↗
PubMed1992

Iodine metabolism in postpartum thyroiditis.

To investigate the etiologic role of iodine intake in postpartum thyroiditis (PPT), we have measured postpartum urinary iodine excretion serially in a large prospective study of PPT. A total of 1996 women were screened for thyroid microsomal antibody during the second trimester of pregnancy. One hundred fifty-two of the 235 antibody-positive women and an equal number of age-matched antibody-negative controls were followed postpartum with measurements of urinary iodine and thyroid function at monthly intervals for 12 months. Iodine excretion in the immediate postpartum period did not differ between the 73 women who developed PPT and the antibody-negative controls. In women with PPT with hyperthyroidism, hypothyroidism, or hyperthyroidism followed by hypothyroidism, increased urinary iodine excretion was observed between 8 and 16 weeks postpartum, which preceded the hormonal disturbances among the women with hypothyroidism. The height of the rise in urinary iodine excretion during the first 20 weeks postpartum correlated with the serum free thyroxine levels (r = 0.61, p less than 0.001). Iodine intake is unlikely to affect the prevalence of PPT. However, these data show that the hyperthyroid phase of PPT is associated with a significant release of intrathyroidal iodine due to thyroid destruction and that the same process also occurs to a lesser extent before the hormonal disturbances associated with hypothyroid PPT.

Autoantibodies↗