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Biomedical subjects

D Todd

Publications and source records attributed to D Todd.

At least 181 records · Page 10Linked to original sources
PubMed1984

Epidemiology of rotavirus infection in broiler chickens: recognition of four serogroups.

In a longitudinal survey of 11 broiler flocks, rotavirus excretion was detected by direct electron microscopic examination of faeces in 10. In most of these flocks, rotavirus excretion was first detected during the third week of life. In some flocks, infection with 2 antigenically distinct serogroups of rotavirus was demonstrated. In a more detailed survey of a 34,000 bird broiler crop, rotavirus excretion was detected intermittently from 9-50 days. Infection with 4 different RNA electropherotypes of rotavirus occurred in waves with each wave of infection lasting about 1 week. Analysis of representatives of the 4 different electropherotypes by cross-immunofluorescence indicated that each electropherotype represented an antigenically distinct serogroup. Two of these serogroups were represented by the previously characterised Ch 1 and 132 chicken rotavirus isolates. The other 2 serogroups have not been previously recognised.

Animals↗
PubMed1984

Iron overload in patients with haemoglobin H disease.

Serum ferritin was measured in 46 Chinese patients with Hb H disease (HbHD) and compared with 84 controls according to age group. Ferritin levels were elevated in 14 of 20 males and 20 of 26 females and the extent of the abnormality increased with age. Splenectomy did not appear to be associated with particularly high levels of serum ferritin in this disease.

Adolescent↗
PubMed1984

Thalassemia.

Explore the source record for details and available documents.

Fetal Hemoglobin↗
PubMed1984

Iron overload in thalassaemic patients in Hong Kong.

Body iron status, as measured by serum ferritin, was studied in 101 adult Chinese thalassaemic patients, 46 males and 55 females. Thirty of them had mild disease (beta thalassaemia trait), 56 disease of intermediate severity (haemoglobin H disease) and 15 severe disease (homozygous beta thalassaemia, Hb E-beta thalassaemia and delta beta-beta thalassaemia). The extent of iron overload correlated with the severity of disease. In severe thalassaemia, iron overload occurred early in life and was independent of multiple transfusions. While significant impairment of left ventricular function was present in only one of six patients studied, evidence of decreased pituitary (especially gonadotrophic) function was observed in six out of seven. Hypocalcaemia, probably due to hypoparathyroidism, was seen in one.

Adolescent↗
PubMed1983

Studies on the antigenic relationship between bovine subgroup 2 and conventional mammalian adenoviruses using immunofluorescence.

In double immunodiffusion tests between a bovine subgroup 2 adenovirus (serotype 8) and other mammalian adenoviruses, no group-specific crossing was demonstrated. However, in cross-fluorescent antibody tests (FAT) between bovine subgroup 2 viruses (serotypes 5, 7 and 8) and conventional (non-subgroup 2) adenoviruses from several species (bovine adenovirus serotypes 1 and 2, ovine serotypes 1, 4 and 5, porcine serotype 1, and human serotypes 2 and 5) sharing of antigens was demonstrated. The FAT titres observed when rabbit antisera to conventional adenoviruses were used to stain bovine subgroup 2 viruses were, however, much lower than titres with other non-subgroup 2 viruses. The converse was also true. The crossing was also predominantly one-sided. The low level cross was confirmed using antisera to selected viruses prepared in chickens to exclude interference by possible natural adenovirus infections in the rabbits used to prepare the antisera in the initial experiments.

Adenoviridae↗
PubMed1983

Evaluation of bubble clicking in gastric aspirate in the newborn.

Gastric aspirates were obtained soon after delivery from 167 babies 24 to 40 weeks gestation. Bubble clicking and foam stability tests were compared for their reliability in determining pulmonary maturity. Both tests predicted mature lungs accurately in 90-91% of babies, however their ability to predict immature lungs was less, bubble clicking predicting it accurately in 88% of babies and foam stability test predicting it in 77% of babies. Bubble clicking, foam stability tests, L/S ratio and two dimensional thin layer chromatography were done in 26 gastric aspirates obtained from 22 babies with mature lungs and 4 babies with with hyaline membrane disease. Phosphatidyl glycerol was present in 21 of the 22 babies with mature lungs. Bubble clicking demonstrated a 95% accuracy and foam stability test 100% accuracy in predicting the presence of phosphatidyl glycerol. Bubble clicking is a useful and easily preformed test in the clinical assessment of a preterm baby.

Chromatography, Thin Layer↗
PubMed1982

The effect of oral contraceptives on coagulation and fibrinolytic parameters in the Chinese--a prospective study.

Thirty-two Chinese and 7 Caucasians were studied prospectively for 12 months for the effects of oral contraceptives (OC) on certain coagulation and fibrinolytic parameters. In both ethnic groups there was an increase in alpha 1 antitrypsin level. There was no significant change in antithrombin III concentration measured either by radioimmunoassay (At-III-RIA) or chromogenic assay (anti Xa-chromogenic) in the Chinese, but a significant decrease in anti Xa-chromogenic at 7 months and At-III-RIA at 12 months in the Caucasians. Also, alpha 2 plasmin inhibitor (alpha 2 PI) levels were unchanged in the Chinese but a significant increase occurred in the Caucasians at 12 months. Enhanced fibrinolytic response to venous occlusion was demonstrated in the Chinese at 12 months but not in the Caucasians.

Adult↗
PubMed1982

Venous thrombosis in haemoglobin H disease after splenectomy.

While venous thrombosis and pulmonary embolism are rare among the Chinese, two of nine patients with haemoglobin H disease developed these complications after splenectomy. The clinical data of the two patients were reported and the relevant literature reviewed. It was concluded that the persistent thrombocytosis and an intravascular haemolysis, particularly prominent in this form of thalassaemia, are contributory to the hypercoagulable state.

Adult↗
PubMed1982

Subjective correlates of small-town population change.

"This study examines subjective correlates-of-place among a set of small towns located in the Manitoba part of the Canadian Prairies. The subjective correlates are discussed in terms of their differences from objective correlates-of-place, the usual indicators of quality-of-life pertaining to a community. A rationale is developed to account for the varying associations of subjective and objective correlates with population change. In particular, analysis attempts to infer which variables are associated with population gain as opposed to population loss."

Americas↗
PubMed1982

The screening of Chinese cord blood for haemoglobinopathies.

The frequency of haemoglobinopathies among the Hong Kong Chinese newborn was examined by screening 932 consecutive cord blood samples by electrophoresis. The findings indicate that 49 (5.2%) had electrophoretic abnormalities, of which 39 (4.2%) demonstrated the presence of Hb Bart's. 14 of these 39 babies were re-investigated after 1 year and all were proven to carry the alpha-thalassaemia gene. This is the first study in which Chinese babies with Hb Bart's in cord blood had the diagnosis of alpha-thalassaemia trait confirmed in later life. 3 out of 4 other babies had different haemoglobin variants, namely Hb alpha Q, Hb J and Hb New York. 1 out of the 6 babies who had elevated A2 levels at birth was found to carry the beta-thalassaemia trait. None had a serious haemoglobinopathy.

China↗
PubMed1982

Midazolam: radioimmunoassay for pharmacokinetic studies in man.

A specific radioimmunoassay (RIA) for the determination of the new short-acting water soluble imidazo-1,4-benzodiazepine, midazolam, directly in plasma has been developed. Employing 3H-midazolam as the radioligand and a rabbit antiserum to a diazo conjugate of 5'-aminomidazolam and albumin, the method has a limit of sensitivity of 2 ng/ml of midazolam using a 20 microliters sample of plasma. The intra- and inter-assay coefficients of variation ranged from 4 to 7% and 13 to 15%, respectively. The specificity of the RIA was established by demonstrating good agreement with both EC-GC and GC-MS procedures in the analysis of multiple clinical plasma samples. The utility of the RIA for the pharmacokinetic evaluation of midazolam is illustrated with plasma concentration profiles of the drug obtained in subjects who had received midazolam intravenously, intramuscularly and orally.

Animals↗
PubMed1982

Salvage chemotherapy for non-Hodgkin's lymphoma.

Nineteen patients with advanced non-Hodgkin's lymphoma resistant to previous chemotherapy were treated with combination chemotherapy consisting of lomustine (CCNU), cytarabine, and prednisone. Eight patients (42%) had complete remission and four (21%) had partial remission. The median survival time of the 19 patients was greater than 14 months. The eight patients who had complete remission were still alive as of May 1, 1982, with a median follow-up time of 632 days (range, 365-1247). We believe that this combination chemotherapy scheme warrants further investigation.

Adult↗
PubMed1981

Enzyme-linked immunosorbent assay for detecting antibodies to Aujeszky's disease virus in pigs.

An indirect micro enzyme-linked immunosorbent assay (ELISA) for detecting antibodies to Aujeszky's disease virus in pigs is described. A control antigen prepared from infected cells was included for each serum tested. Of 243 sera from serologically positive farms, 175 (72 per cent) and 147 (60 per cent) were positive by the ELISA test and microtitre serum neutralisation test, respectively. Failure to include a control antigen for each serum would have resulted in 14 sera (6 per cent) being differently recorded. Results for sera from experimental and field infections indicated that seroconversion was more quickly detected by the ELISA test than the microtitre serum neutralisation test. In addition to greater sensitivity the ELISA test has other advantages over the serum neutralisation test. ELISA is a rapid, cheap test which is not dependent on a continuous supply of cell cultures and which can be readily automated.

Animals↗
PubMed1981

Clinical features of hepatocellular carcinoma: review of 211 patients in Hong Kong.

A retrospective study of 211 patients with proven hepatocellular carcinoma (HCC) was made. The commonest symptoms were anorexia and malaise (73%). Five patients (2.5%) had near-normal biochemical tests despite the presence of massive tumors. Diagnostic yield from angiography, percutaneous peritoneoscopic biopsy, or scintiscanning was 87-98%. Three percent of the patients had resectable tumors. Median survival for patients with untreated disease was 3.5 weeks. Apart from histology, the total serum bilirubin level was the only factor of prognostic value. Only 12 patients had preexisting symptomatic cirrhosis. When compared with 80 patients with symptomatic postnecrotic cirrhosis without malignancy, patients with HCC had higher SGOT:SGPT ratio, Higher serum albumin levels, and higher platelet counts. There was only minimal overlap of patients with symptomatic postnecrotic cirrhosis and those with HCC. The authors conclude that their patients with HCC appeared late for treatment. A probable difference in the development of symptomatic postnecrotic cirrhosis and of HCC with asymptomatic postnecrotic cirrhosis is suggested.

Adolescent↗