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Biomedical subjects

D L Barnard

Publications and source records attributed to D L Barnard.

At least 55 records · Page 3Linked to original sources
PubMed1991

Changes in serum erythropoietin levels during allogeneic bone marrow transplantation.

Serial serum erythropoietin levels were measured in 10 consecutive patients undergoing allogeneic bone marrow transplantation. Observed erythropoietin levels are compared with those predicted from a large control population of anaemic patients not receiving chemotherapy. There was an initial acute rise in serum erythropoietin, peaking between days 1 and 4 after marrow transfusion, which was unrelated to changes in haemoglobin concentration. Patients maintained serum erythropoietin concentrations at around twice the predicted level for the first 2 weeks following transplantation, with a gradual fall into the expected range by wk 3. Erythropoietin levels did not change with episodes of bacterial infection or acute graft-versus-host disease. A patient with severe aplastic anaemia had initial successful engraftment with normalisation of erythropoietin levels, but showed a marked and amplified rise in erythropoietin 2 wk before falling peripheral blood counts indicated failure of the bone marrow graft.

Adolescent↗
PubMed1988

Effects of ribamidine, a 3-carboxamidine derivative of ribavirin, on experimentally induced Phlebovirus infections.

Ribamidine (1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamidine) was inhibitory in rhesus monkey kidney (LLC-MK2 derivative) cells to Adames and Balliet strains of Punta Toro virus (PTV), a Phlebovirus related to Rift Valley fever and sandfly fever viruses. The 50% effective dose was 8 and 12 micrograms/ml against each respective virus strain; the 50% cytotoxic dose was 320 micrograms/ml, giving selectivity indices of 40 and 27 against each virus strain. The virus ratings were 1.2 and 1.0, respectively. In radiolabel uptake studies, ribamidine had a moderate effect on [3H]leucine uptake at dosages down to 1 microgram/ml, but [3H]thymidine, [32P], and [3H]uridine were inhibited at high (100-1000 micrograms/ml) doses only. Subcutaneous (s.c.) and oral treatments of Adames PTV-infected mice were equally highly effective, as evidenced particularly by 100% survivors. Reduced hepatic icterus, serum oxalic acid transaminase, serum glutamic pyruvic acid transaminase, and recoverable virus titers from livers and sera of infected mice were also seen as a result of ribamidine treatment. Twice daily treatment for 5 days could be started as late as 72 h post-virus inoculation (p.v.i.) with significant inhibition of PTV infection seen. Single s.c. treatments administered as late as 48 h p.v.i. were similarly effective. Using the chronic therapy schedule, the maximum tolerated dose was 1000 mg/kg/day and the minimum effective dose was 31.3 to 62.5 mg/kg/day. Using single treatment, a maximum tolerated dose was greater than 1000 mg/kg, and the minimum effective dose was 125 mg/kg. Ribamidine s.c. treatment of mice infected intracerebrally with the Balliet strain of PTV resulted in a moderate infection-inhibitory effect, seen especially by reduced virus titers in the brains of the infected, treated mice.

Administration, Oral↗
PubMed1987

Vitamin B12 absorption after allogeneic bone marrow transplantation.

The B12 absorption test (Schilling test) with intrinsic factor was used to examine ileal B12 absorption in 26 patients after allogeneic transplantation. The test was well tolerated and showed a profound fall in B12 absorption, which was maximal at two weeks after transplantation and recovered by eight weeks. The predominant influence on absorption at this stage was probably the conditioning schedule, and the presence of acute graft versus host disease (GVHD) was not associated with a further impairment of absorption. Six patients with chronic GVHD were studied. When compared with nine patients without GVHD there was a significant (p less than 0.005) reduction of B12 absorption. These findings suggest that the B12 absorption test may be a useful non-invasive method of studying bowel function after bone marrow transplantation.

Adolescent↗
PubMed1986

Suitability of new chlamydia transport medium for transport of herpes simplex virus.

A new chlamydia transport medium (ChlamydiaPort; Scott Laboratories, Inc., Fiskeville, R.I.) was evaluated for its suitability as a transport medium for herpes simplex virus (HSV). Two laboratory HSV strains (McIntyre and 333) and two clinical isolates (AO218 and AO301) were suspended in ChlamydiaPort, ViraPort (Scott Laboratories), and cell culture medium and maintained at 2 and 22 degrees C. Samples were tested at various time intervals to determine surviving virus. The range of half-lives of the HSV strains held at 2 degrees C in ChlamydiaPort medium was from 3.5 to 10 days, while virus stability was greater in ViraPort and less in cell culture medium. These HSV strains held at 22 degrees C in ChlamydiaPort had half-lives from 1.5 to 6 days, which were significantly greater than the half-lives of the viruses held in either tissue culture medium or ViraPort. Clinical specimens were tested for virus by using the Selecticult-HSV (Scott Laboratories) system to determine the performance of the transport medium under field conditions. Clinical specimens maintained up to 5 days at ambient temperatures in ChlamydiaPort medium appeared suitable for diagnostic testing without detectable loss of positive specimens. In addition, there was a significant decrease in the average time required for diagnosis when compared with a standard transport system, Virocult (Microdiagnostics, Cleveland, Ohio). These results show that HSV infections can be successfully diagnosed in distant virology laboratories by shipping specimens in ChlamydiaPort transport medium at ambient temperatures.

Chlamydia↗
PubMed1985

Comparison of an avidin-biotin immunoassay with three commercially available immunofluorescence kits for typing of herpes simplex virus.

An avidin-biotin complex system was compared with three commercially available immunofluorescence kits for serotyping herpes simplex virus isolates from clinical specimens. Sensitivity values showed that the Electro-Nucleonics and Immulok reagents were useful in detecting the presence of virus, whereas the predictive values showed that the Syva and Immulok reagents possessed adequate discrimination between the herpes simplex virus serotypes. The avidin-biotin complex system was equal or superior to the immunofluorescence reagents tested both in detecting herpes simplex virus antigens in cell culture and in serotyping herpes simplex virus isolates.

Antigens, Viral↗
PubMed1983

A retrospective evaluation of mediastinal tomograms, isotope liver scans, and isotope bone scans in the staging and management of patients with lymphoma.

The influence of mediastinal tomograms and isotope scans of liver and bone on the initial staging and management of patients with lymphoma has been studied. There appears to be only a small role for these investigative procedures, and it is suggested that considerable savings in time and money can be made by a more judicious use of these techniques.

Adolescent↗
PubMed1983

A pilot study of cyclical chemotherapy with high-dose methotrexate and CHOP (MTX-CHOP) in poor-prognosis non-Hodgkin's lymphoma (NHL).

In a pilot study of cyclical chemotherapy in patients with poor-prognosis non-Hodgkin's lymphoma (NHL), high-dose methotrexate (MTX) 1 g/m2 with folinic acid rescue was given as initial treatment and then between cycles of a single-arm CHOP combination administered every 4 weeks. Of 21 patients with previously untreated or minimally treated grade 2 (high-grade) histology stage II/III/IV NHL, 13 (62%) achieved complete remission (CR); the CR rate for stage III/IV patients was 56%. Of all 25 patients with grade 2 stage II/III/IV NHL, including previously treated patients, 16 (64%) achieved CR. The median follow-up of patients who completed treatment is currently 22 months and only 1 relapse has been recorded in the CR group. Only five of 24 grade 2 patients given the initial 'test' MTX failed to show any response, and eight patients achieved partial remission (PR) as a result of this single treatment. The response to MTX-CHOP in nine patients with grade 1 (low-grade) histology NHL was poor; only two achieved CR. These findings lend support to other data which indicate a useful role for MTX in the induction chemotherapy of advanced high-grade NHL, though the optimum dosage and drug sequence have yet to be determined.

Adolescent↗
PubMed1983

Thrombocytosis and microthrombocytosis: a clinical evaluation of 372 cases.

Data on 372 patients with thrombocytosis (TC), defined as a platelet count over 500 X 10(9)/1, were accumulated in a non-biased fashion. Surgery, per se, was a common cause of TC and malignancy, if uncomplicated by infection, bleeding or surgery, was a less common cause of TC than suggested in previous surveys. The reasons for these apparent differences are discussed. Postoperative TC resolved within 30 days of surgery in the absence of complications. Transient reactive TC due to a variety of causes was accompanied by a significant fall in platelet volume in contrast to the megathrombocytosis found in postsplenectomy and myeloproliferative TC.

Anemia, Hypochromic↗
PubMed1981

IgE lambda paraproteinaemia associated with a pleomorphic lymphoproliferative disorder.

A new case of IgE lambda paraproteinaemia is described in which the immunoproliferative disorder was lympho-plasmacytoid, rather than myelomatous in type. The patient, an 81-year-old woman, lacked both organomegaly and bone lesions. The peripheral white blood count was 30 X 10(9)/l (43% lymphocytes and 37% lymphoplasmacytoid cells) and the bone marrow was heavily infiltrated with mononuclear cells with 50% lymphocytes and 50% lymphoplasmacytoid cells). Detailed immunological marker analysis of both peripheral blood and marrow showed an increased population of morphologically normal T cells, together with neoplastic population of B cells. The neoplastic cells were shown to re-express surface immunoglobulin after stripping with anti-E anti-serum, and to synthesis Ig in radio-incorporation experiments. The immunological characteristics of the neoplastic cells are considered in relation to B-cell maturation and it is shown that the immunological phenotype was of the intermediate type to be expected in association with a lympho-plasmacytoid proliferation.

Age Factors↗
PubMed1979

Chronic myelomonocytic leukemia with paraproteinemia but no detectable plasmacytosis: a detailed cytological and immunological study.

A patient with chronic myelomonocytic leukemia with IgG K paraproteinemia, but no detectable plasmacytosis, is described. The patient was entering a blastic phase at the time of the most detailed studies. Cytological, cytochemical, and ultrastructural studies revealed a mixed myeloid proliferation with granulocytic forms predominating over monocytic elements. A variety of ultrastructural abnormalities, including defective granulation, was observed but no cells with highly developed rough endoplasmic reticulum were observed. Immunological marker studies showed that the mature myeloid cells possessed receptors for the Fc of IgG and weakly expressed the Ia-like P29/34 antigen. The mature myeloid cells also expressed both surface and intracytoplasmic Ig restricted to IgG K, and this IgG K persisted after 4 weeks in culture. A reverse plaque assay showed that the myeloid cells were capable of releasing IgG K in vitro, but studies involving the incorporation of radio-labeled amino acids showed no detectable Ig production by the myeloid cells. The possible interpretations of these data are discussed in some detail in relation to previous reports of paraproteinemia in myeloid proliferative disorders.

Aged↗
PubMed1973

Outbreak in Bristol of conjunctivitis caused by adenovirus type 8, and its epidemiology and control.

In an investigation of an outbreak of adenovirus type 8 infection involving over 40 people it was found that the infection spread initially within the eye hospital, but subsequently involved several family contacts and two local hospitals for mentally subnormal patients. Presumptive diagnosis should be possible before subepithelial opacities have developed provided an adequate history is taken, and had that been done in this outbreak it is reasonable to suppose that many cases could have been prevented.

Adenoviridae↗
PubMed1973

Bile acids and vitamin A absorption in man: the effects of two bile acid-binding agents, cholestyramine and lignin.

In 14 healthy volunteers, the addition of 12 g cholestyramine to a vitamin A-containing test meal reduced the expected rise in serum vitamin A by 59.5% (p<0.001). By contrast, lignin had no significant effect in 12 subjects. This study confirms the importance of bile acids in vitamin A absorption and the ineffectiveness of lignin as a sequestrator of conjugated bile acids.

Adult↗