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Biomedical subjects

B Paul

Publications and source records attributed to B Paul.

At least 55 records · Page 3Linked to original sources
PubMed1996

Efficacy of recombinant interferon-alpha (rIFN-alpha) in polycythaemia vera: a study of 17 patients and an analysis of published data.

The efficacy and tolerability of rIFN-alpha has been evaluated in 17 selected patients with symptomatic polycythaemia vera, diagnosed according to the PRV Study Group criteria. Complete disease control (CR) was achieved, after 1-12 months, in nine patients, with partial control in a further five cases. Three patients failed to respond. Pruritus significantly improved in 83% (10/12) of cases, following 1-28 weeks of treatment. Six patients (35%), however, were unable to tolerate rIFN-alpha, on account of weight loss, myalgia and mental changes. Overall, alpha-interferon therapy significantly improved venesection requirements, MCV and PCV values, platelet counts, pruritus scores and the degree of splenomegaly. Analysis of pooled published data (100 evaluable patients, including the present study) revealed an overall CR of 60%, a PR of 27%, and a failure rate of 13%. Significant pruritus control (> 50% improvement) occurred in 77% of cases. rIFN-alpha appears to be an effective therapy for PV-associated myeloproliferation and/or pruritus, although side-effects remain a concern. Long-term studies are now indicated to determine if the natural history of the disease is altered, in particular whether the incidence of myelofibrosis and/or leukaemic transformation is reduced.

Adult↗
PubMed1994

Deletion of chromosome 20q in myelodysplasia can occur in a multipotent precursor of both myeloid cells and B cells.

Deletions of the long arm of chromosome 20 are associated with several myeloid malignancies and, in particular, with myeloproliferative disorders and myelodysplastic syndromes (MDS). Together with deletions of chromosome 5q and chromosome 7q, chromosome 20q deletions have previously been thought to be restricted to myeloid cells in patients with MDS. We report here that deletion of chromosome 20q in MDS can arise in a multipotent precursor of both myeloid cells and B cells. Clonal Epstein-Barr virus (EBV)-transformed cell lines, both with and without a 20q deletion, have been isolated from a patient with MDS. Moreover, these cell lines have been shown to provide a useful physical mapping tool and have been used to confirm the interstitial nature of the 20q deletion. Microsatellite polymerase chain reaction (PCR) and PCR analysis of PGK gene methylation have been used to study highly purified populations of peripheral blood cells. The 20q deletion was detectable by microsatellite PCR in peripheral blood granulocytes and monocytes but not in B cells or T cells. Clonality of the different lineages followed the same pattern as the 20q deletion. This represents the first report in which a chromosome abnormality associated with MDS has been immortalized in an EBV-transformed lymphoblastoid cell line. Furthermore, our data show that patients with apparent myeloid restriction of a chromosome deletion may in fact have a disease arising in a multipotent cell with both myeloid and lymphoid potential.

Aged↗
PubMed1994

Further evidence that activated protein C resistance can be misdiagnosed as inherited functional protein S deficiency.

A recent report that activated protein C (APC) resistance interferes with functional protein S (PS) assays prompted us to re-investigate two pedigrees previously diagnosed as having functional PS deficiency. APC resistance was demonstrated in all individuals with apparent functional PS deficiency. The latter diagnosis was shown to be due to the assay being non-linear, functional protein S becoming normal at higher dilutions. This observation, taken in conjunction with results of in vitro recovery studies with purified PS, leads us to conclude that APC resistance was the primary disorder in both pedigrees. The misdiagnosis of APC resistance as functional PS deficiency can be prevented by performing the PS assay at several dilutions, including concentrations lower than those recommended by PS assay manufacturers. Subjects previously diagnosed as having functional PS deficiency should be re-investigated for APC resistance.

Antigens↗
PubMed1994

Unusual infections following allogeneic bone marrow transplantation for chronic lymphocytic leukemia.

Unusually severe infections phenomena were observed in three patients with chronic lymphocytic leukemia (CLL) who had undergone allogeneic bone marrow transplantation (BMT) from matched sibling donors. The first developed three episodes of cytomegaloviremia requiring anti-viral therapy; the third episode accompanied by cytomegalovirus hepatitis which required prolonged therapy with foscarnet. Another had Listeria monocytogenes meningitis which was difficult to eradicate and required prolonged maintenance antimicrobial therapy with oral trimethoprim-sulfamethoxazole and intrathecal gentamicin until death due to chronic graft-versus-host disease. The third patient had cytomegaloviremia lasting 47 days, which did not clear within 4 weeks of full-dose ganciclovir. Although the number of patients is small, in our experience the problems encountered were unusually severe compared with patients allografted for other disease. We conclude that CLL patients undergoing allogeneic BMT may be at a higher risk of infectious complications than patients allografted for other diseases, and require careful monitoring.

Adult↗
PubMed1994

Myelodysplastic syndromes (MDS) in Central Africans.

Forty two patients who were seen and satisfied the French-American-British (FAB) diagnostic criteria for myelodysplastic syndromes (MDS) over a 6-year period at the University of Zimbabwe's Department of Haematology, Harare, are presented. Their overall ages ranged from 29 to 75 years with a mean +/- SD of 57.8 +/- 11.2 years. Males outnumbered females with a male to female ratio of 1.2:1. Refractory anaemia (RA) occurred in 33.3%; refractory anaemia with ringed sideroblasts (RARS) in 16.7%; refractory anaemia with excess blasts (RAEB) in 21.4%; refractory anaemia with excess blasts in transformation (RAEB-T) in 16.7% and chronic myelomonocytic leukaemia (CMML) in 11.9% of the patients. In 90.5% the disease was primary and in 9.5% prior exposure to myelotoxic agents resulted in secondary MDS. The study reveals that MDS as a cause of anaemia in the African population is usually hidden in the big number of well known anaemias due to rampant malaria, malnutrition and a host of nutritional deficiencies. There is therefore the need to increase diagnostic awareness among our clinicians about the existence of these disorders.

Adult↗
PubMed1993

Refined linkage map of chromosome 5 in the region of the spinal muscular atrophy gene.

The genetic map in the region of human chromosome 5 that harbors the gene for autosomal recessive forms of spinal muscular atrophy (SMA) has been refined by a multilocus linkage study in 50 SMA-segregating families. Among six markers spanning 8 cM for combined sexes, four were shown to be tightly linked to the SMA locus. Multipoint linkage analysis was used to establish the best estimate of the SMA gene location. Our data suggest that the most likely location for the SMA locus is between blocks AFM114ye7 (D5S465)/EF5.15 (D5S125) and MAP-1B/JK53 (D5S112) at a sex-combined genetic distance of 2.4 and 1.7 cM, respectively. Thus the SMA gene lies in the 4-cM region between these two blocks. This information is of primary importance for designing strategies for isolating the SMA gene.

Base Sequence↗
PubMed1992

Dissociation between the effects of benzodiazepine receptor agonists on behavioral vigilance and responsitivity.

The effects of benzodiazepine receptor (BZR) full agonists chlordiazepoxide and midazolam, and the partial agonist beta-carboline ZK 91,296 on the rat's performance in a simple reaction time paradigm were examined. This task required the animals to respond to a rarely and unpredictably occurring brief (50 ms) visual stimulus. Non-parametric measures of signal sensitivity and response bias derived from signal-detection theory were used as a basis for the dissociation between the effects of these drugs on attentional abilities and general responsivity. The dose-dependent effects of midazolam (0.1-3.13 mg/kg) on signal sensitivity and general responsivity occurred in parallel. In contrast, the effects of chlordiazepoxide (1.56-12.5 mg/kg) on signal sensitivity were largely independent from effects on response bias. The partial agonist ZK 91,296 (0.39-25 mg/kg) in general had little effect on performance. The effects of the highest doses of chlordiazepoxide and midazolam were reversed by the co-administration of the BZR antagonist Ro15-1788 (15 mg/kg). Additionally, extension of the stimulus presentation time to 500 ms decreased the magnitude of the effect of chlordiazepoxide on signal sensitivity. These results support the hypothesis that BZR agonist-induced disruption of attentional abilities is not necessarily confounded by effects on general responsivity or sedation, and thus may represent a discrete pharmacological property of BZR-agonists.

Animals↗
PubMed1992

A report of 104 transfusion errors in New York State.

In New York State, significant incidents involving the collection, processing, or transfusion of blood must be reported. Incident reports received over a 22-month period involving transfusion of blood to other than the intended recipient or release of blood of an incorrect group were analyzed. Among 1,784,600 transfusions of red cell components; there were 92 cases of erroneous transfusion that met study criteria (1/19,000). There were 54 ABO-incompatible transfusions (1/33,000); three of these (1/600,000) were fatal. Correction for underreporting of ABO-compatible errors resulted in an estimate of 1 per 12,000 as the true risk of transfusion error. National application of New York State data results in an estimate of 800 to 900 projected red cell-associated errors in the United States annually. The majority of reported errors occurred outside of the blood bank (43% resulted solely from failure to identify the patient and/or unit prior to transfusion and 11% resulted from phlebotomist error), while the blood bank was responsible for 25 percent of errors and contributed, with another hospital service, to 17 percent. The risk of transfusion of ABO-incompatible blood remains significant, and additional precautions to minimize the likelihood of such events should be considered.

ABO Blood-Group System↗
PubMed1992

Infection of peripheral blood mononuclear cells and cell lines by cell-free human T-cell lymphoma/leukemia virus type I.

Previous studies of in vitro infection by human T-cell lymphoma/leukemia virus type I (HTLV-I) have required cocultivation of target cells with HTLV-I cell lines or vesicular stomatitis virus pseudotypes containing HTLV-I envelope proteins. We report here the development of a cell-free infection assay for HTLV-I. Target cells were incubated with purified, DNase-treated HTLV-I virions for 4 h at 37 degrees C. Target cell DNA was then analyzed for the presence of newly synthesized HTLV-I proviral DNA by the highly sensitive polymerase chain reaction. Using this assay system, we have been able to consistently detect in vitro infection of a variety of cellular targets by different HTLV-I isolates. Optimal infection required the presence of 10 micrograms of DEAE-dextran per ml. The assay was dose dependent with respect to virus input. In general, the amount of proviral DNA detected correlated with the level of HTLV-I receptors present on the surface of the target cells, as measured by fluorochrome-labelled HTLV-I binding. Finally, the specificity of the assay was confirmed by demonstrating that the cell line, L1q, a somatic cell hybrid containing human chromosome 17q, to which the gene for the HTLV-I receptor has been mapped, was susceptible to infection by HTLV-I, while the parental mouse cell line from which it was derived, LMTK-, which lacks human chromosome 17q, was not.

Adult↗
PubMed1992

A three-year prospective study of 137 cases of acute leukaemia in Zimbabwe.

We studied 137 cases of acute leukaemia seen between December 1985 and November 1988, using traditional staining techniques together with cytochemistry and in cases of probable acute lymphoblastic leukaemia (Sudan Black negative) by immunophenotyping. Not all tests were carried out in every case (some cases of ALL could only be classified as T or non-T). Paediatric group (age less than or equal to 14 yrs): 75 cases--acute lymphoblastic leukaemia 52, acute myeloid leukaemia 18, acute undifferentiated leukaemia 5. Peak incidence in 5-9 year group. Male:Female ratio = 1.7:1. acute myeloid leukaemia was associated with chloromas in 2 cases (11 pc). Adult group: 62 cases--acute lymphoblastic leukaemia 23, acute myeloid leukaemia 36 and acute undifferentiated leukaemia 3. Peak incidence in 50-54 age group. Male:Female ratio = 1:1.2. Acute lymphoblastic leukaemia subtypes (all ages) T 16, Common 20, Null 12, 'non-T' 16, B cell 0, untyped 11. 69 pc were of L2 morphology. In T-ALL, 11 had thymomas and Male:Female ratio = 15:1. Male:Female ratio for 'non-T' = 1.5:1. Acute myeloid leukaemia subtypes (all ages) M1 3, M2 8, M3 14, M4 19, M5 8, M6 2, M7 1. Overall incidence of acute leukaemia appears increased at 0.91 per 100,000 per annum from previous studies in Zimbabwe. Common ALL (mean age = 13 years) is an emerging problem and now outnumbers T-ALL (mean age = 10 years). This may be related to a general improvement in living standards and health in Zimbabwe.

Acute Disease↗
PubMed1992

[Individual plaque flora determination in periodontal diseases. Methods and standardization].

The dental plaque of 15 patients with gingivitis and of 15 patients with marginal periodontitis was won by means of two different methods of isolation and sampling. Either the plaque was sampled by a scaler with and without covering the crown. The estimation of plaque-microflora was done by microscopical and cultural bacteriological methods. Differences in the composition of plaque-microflora could be found in dependence of method used in isolation and sampling. Also differences in bacterial colonisation of different regions were found using the same technique of sampling. The subgingival plaque in marginal periodontitis was different of the plaque in gingivitis. In plaque-microflora of periodontitis the percentage of gram-positive cocci and rods was decreasing, the percentage of gram-negative and mobile bacteria was increasing compared with the bacterial flora in gingivitis. In the subgingival plaque in gingivitis streptococci and actinomyces were the predominant bacteria.

Bacteriological Techniques↗
PubMed1991

von Willebrand's disease in Zimbabwe. A report on 3 families.

Three families with clinically typical features of von Willebrand's disease are described. One family had features to suggest type II disease. Von Willebrand's disease appears to be rare in Africa, but this may be due both to lack of awareness among clinicians and insufficient laboratory facilities.

Adolescent↗