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Biomedical subjects

J Pritchard

Publications and source records attributed to J Pritchard.

At least 253 records · Page 14Linked to original sources

Chemotherapy of advanced neuroblastoma: does adriamycin contribute?

Between 1970 and 1977, 69 children with newly diagnosed stage III or IV neuroblastoma were treated with pulses of either cyclophosphamide and vincristine (CV) (n = 23), or cyclophosphamide, vincristine, and adriamycin (CVA) (n = 46). The 'complete' and partial response rates were 35 and 22% to CV, and 43 and 26% to CVA. For 'complete' responders the median time to relapse was 18 months for those treated with CV, and 17 months for those treated CVA; for partial responders the times were 5 and 7 months respectively. At 2 1/2 years only 17% of the CV patients and only 13% of the CVA patients were alive and free of disease, giving a 15% overall survival rate. The addition of adriamycin to cyclophosphamide and vincristine did not significantly improve the response rate, duration of response, or survival in these children with advanced neuroblastoma. The previously noted favourable effects of age less than 1 year at diagnosis and of female sex were confirmed. The equally poor survival for stage III and stage IV patients justifies the inclusion of stage III patients in a bad prognosis group.

Abdominal Neoplasms↗

Documentation of Epstein-Barr virus infection in immunodeficient patients with life-threatening lymphoproliferative diseases by clinical, virological, and immunopathological studies.

Multiple methods, pedigree analysis, clinical evaluation, and Epstein-Barr virus (EBV)-specific serology, EBV DNA hybridization of tissues to probe for viral genome, staining of touch imprints for EBV nuclear-associated antigen, establishment of spontaneous infected B-cell lines from peripheral blood or tissues, examination of peripheral blood smears, and hematopathology studies, were used to study seven patients with the X-linked lymphoproliferative syndrome and seven additional patients with life-threatening EBV-associated diseases. These studies demonstrated EBV in the tissues of all 14 patients and immunodeficient antibody responses to EBV were documented. This virus can produce various life-threatening lymphoproliferative diseases in a variety of immunodeficient patients.

Adolescent↗

Neuroblastoma: a review of 21 cases presenting with spinal cord compression.

The records of 21 children with neuroblastoma presenting with spinal cord compression, encountered over 17 years, were reviewed. Thirteen patients (61%) survive, free of neuroblastoma, at intervals ranging from nine months to 192 months (median, 78 months) from the time of diagnosis. The explanation for this relatively high survival rate was sought in an analysis of the cases which took into account age, site, extent of disease, and histology. The most significant features to emerge were the unusually high proportion of children under 12 months of age at presentation (11 of 21) most of whom survive (9 of 11) and the low incidence (3 of 21) of detectable at the time of diagnosis. The absence of a paraspinal mass was an unfavourable prognostic features (1 of 6 survives) whilst if a paraspinal mass was present, its anatomical level did not influence survival. In particular, children with retroperitoneal tumors fared no worse (survival, 6 of 7) than those with primary tumors at other sites (survival, 6 of 8). Morbidity was high (6 of 13), principally in infants with spinal cord compression from birth. Survival was also related to the histologic maturity of the tumor, even in the presence of metastases. Recommendations for management are made.

Catecholamines↗

HLA-A, B and C antigens in South Indian families with leprosy.

Seventy-two families, selected for having at least two children affected with leprosy, were HLA typed for 57 A, B and C locus antigens recognized by the WHO Nomenclature Committee. In addition, 20 possible new "splits" were investigated. The distribution of A, B and C locus antigens in affected and unaffected family members was similar, irrespective of the type of leprosy in the family. Gene frequencies (derived by direct gene counting from 253 haplotypes), haplotype frequencies and delta values were calculated. There is evidence for heterogeneity of B5, B15, B17, Bw16 and Bw35 and for the existence of at least one A locus and one B locus antigen not previously detected. The value of the HLA system for detecting expaternal children in a highly inbred population and the effect of inbreeding on the HLA system is discussed.

Chromosome Mapping↗

HLA-linked genes and leprosy: a family study in Karigiri, South India.

The evidence for a genetic determination of susceptibility to leprosy is reviewed. To test the hypothesis that an HLA (histocompatibility leukocyte antigen)-linked gene is associated with such susceptibility, the association between the distribution of leprosy within a family and the segregation of HLA haplotypes was investigated among 72 families who lived in Karigiri, Tamil Nadu State, South India. A statistically significant association was found for families in which siblings had tuberculoid leprosy and in which neither parent had leprosy. The findings from the data of this study agree with those of two previous studies carried out among smaller populations is Surinam and Wardha, Maharashtra State, India. Such an agreement suggests that a genetic determinant which is linked to the major HLA locus on chromosome 6 and which is probably recessive affects susceptibility to tuberculoid leprosy in humans.

Alleles↗

High dose melphalan and non-cryopreserved autologous bone marrow treatment of malignant melanoma and neuroblastoma.

Autologous non-cryopreserved bone marrow infused 8 hours after an intravenous injection of melphalan, 140 mg/m2, accelerates bone marrow recovery. This effect is most noticeable in the recovery of peripheral blood granulocytes. Twenty patients with disseminated malignant melanoma were treated with this regimen: there were 12 responses, two of them complete but the toxicity of the treatment was not sufficient to justify using this method of treatment routinely since survival was little influenced by treatment (4-11 months). In 8 patients with disseminated neuroblastoma, high dose melphalan/autograft was used in a program of combined modality treatment. Three of the patients are disease free at 16, 11 and 6 months and in one the disease is 'static', not having grown for 13 months. The treatment for this tumour deserves further exploration, and perhaps similar treatment ought to be explored for other tumours.

Bone Marrow Transplantation↗

Colonic function in patients with diverticular disease.

Diverticular disease is thought to be associated with prolonged intestinal transit-time, a reduced stool weight, and increased intracolonic pressure. Sixty patients with diverticular disease did not regularly show these features. Variation in colonic function was considerable in these patients and was similar to that in the general population from which the patients were recruited. Constipation may be a complication of diverticular disease and not necessarily part of its aetiology.

Adult↗

Ultrasonography in the management of unexplained renal failure.

A series of seven cases of acute renal failure is presented in which sonographic study of the kidneys provided diagnostic information not otherwise obtainable. Ultrasonic imaging should be among the first diagnostic procedures applied in cases of acute unexplained renal failure because it provides rapid answers to the most urgent management problems--whether there is an obstructive component, and what is the potential for recovery.

Acute Kidney Injury↗

Variability in the amount of beta-globin mRNA in beta0 thalassemia.

Globin mRNA isolated from a number of beta0 thalassemia patients of different ethnic origins was analyzed by RNA-cDNA hybridization and, in two cases, by fingerprint analysis of 125I-labeled mRNA. Quantitation of the relative amounts of alpha- and beta-mRNA by hybridization to purified alpha-and beta-cDNA revealed that in approximately half the cases, there was less than 1% as much beta-mRNA as alpha-mRNA. In the rest of the cases, low levels of beta-like mRNA were detected in amounts 4-12% as abundant as alpha-mRNA. There was variability in the yield of beta-like mRNA in patients of the same racial group, in the same patient at different times and in similarly affected siblings: beta-mRNA was virtually absent in some samples, whereas low but significant levels were found in other samples. In one patient, beta-like mRNA was not detected in peripheral blood RNA, but was present in the RNA of bone marrow cells. In one case, the thermal stability of the beta0 thalassemia mRNA-beta-cDNA hybrid was measured and found to be slightly lower than that of the authentic beta-mRNA-beta-cDNA hybrid. In none of the cases tested was there synthesis of beta-globin chains directed by beta0 thalassemia mRNA in a cell-free protein-synthesizing system, even when beta-like mRNA was detected in the sample by hybridization assays. mRNA from two patients was labeled in vitro with 125I, digested with T1 RNAase and fractionated in two dimensions. Analysis of the resulting fingerprints revealed the presence of prominent alpha chain-specific oligonucleotides without detectable beta chain-specific oligonucleotides, and thereby confirmed the results of hybridization assays showing absent or very low levels of beta-mRNA in the same RNA samples. Our results support the concept that beta0 thalassemia is heterogeneous in its molecular basis even within the same racial group: in some patients, it is associated with absent beta globin mRNA, whereas in other patients, it is associated with low but significant levels of nonfunctional beta or beta-like globin mRNA. The variable amounts of beta-like mRNA detected in different samples from the same patient, and in patients with the same genotype, indicate that as yet undefined factors can influence the yield of beta-like mRNA observed in beta0 thalassemia.

Blood Cells↗

Comparison of bran, ispaghula, and lactulose on colon function in diverticular disease.

Bran, ispaghula (Fybogel), and lactulose were given to three groups of patients with diverticular disease for four weeks. Faecal weights, bile acids, fat and electrolytes, transit time, and colonic motility were estimated before and after treatment. Stool weight increased, notably with Fybogel. Cereal bran had the greatest effect on the transit time, reducing it significantly. There were no changes in faecal bile acids, fat or electrolytes. Coarse bran reduced colonic motility and the number of high pressure waves after food; Fybogel increased the basal pressure and was without effect on the food-stimulated pressures; whereas lactulose influenced neither. All agents paradoxically equally alleviated symptoms.

Adult↗

Assay of thalassaemic messenger RNA in the wheat germ system.

Messenger RNA(mRNA) has been prepared from reticulocytes obtained from patients with different types of thalassaemia and assayed in the wheat germ system. Since normal human reticulocyte mRNA directs the synthesis of equal numbers of alpha- and beta-globin chains in this system it offers a rapid and simple technique for assaying mRNA in the thalassaemic disorders. In mRNA from beta+ thalassaemics the deficiency of beta-globin synthesis mirrored that observed in intact reticulocytes while that prepared from patients wiht haemoglobin H disease gave alpha/beta globin chain production ratios which showed consistently greater imbalance than was found in reticulocytes. Messenger RNA prepared from haemoglobin E-beta0 thalassaemics from Thailand directed no detectable beta-chain synthesis while that prepared from a betaO thalassaemic from Ferrara synthesized a fraction with the chromatographic characteristics of beta-globin chains.

Globins↗

The patterns of fetal haemoglobin production in leukaemia.

Elevated levels of haemoglobin F (Hb F) have been foudn in a wide range of haematological malignancies, but very high levels were found only in juvenile chronic myeloid leukaemia (JCML), and erythroleukaemia occurring in infancy. In both these disorders a reversion to a fetal form of erythropoiesis may occur, as judged by both the structure of the Hb F and by the disappearance of Hb A2 and the carbnoic-anhydrase isozymes during the course of the illness. The clinical picture of JCML is not always associated with a reversion to fetal erythropoiesis; there appears to be a heterogeneity of conditions with this clinical label. Thus the reversion to a completely fetal pattern of erythropoiesis seems to occur in a variety of leukaemias which start in early life. This change is associated with a uniformly bad prognosis. Of a group of 17 patients with acute myeloid leukaemia 15 developed an increase in the level of Hb F about 60 days after the commencement of treatment; significantly greater increases were observed in those achieving a clinical remission. The level of Hb F usually declined during remission but high levels persisted in a few cases. Increased levels of Hb F were found also in patients with other haematological malignancies who had undergone periods of marrow aplasia during treatment. In all cases the Hb F was heterogeneously distributed throughout the red cells. Analysis of gamma15 or gammaCB3 peptides of Hb F from a variety of leukaemias gave glycine compositions ranging from 0.20 to 0.85 residues with many values in the fetal range; all cases with a reversion to fetal erythropoiesis had values in the fetal range. Attempts to confirm the 'fetal' origin of the cells containing Hb F by means of other markers was possible only in the cases of JCML and in one child with erythroleukaemia. These studies indicate that in some forms of leukaemia there may be a genuine reversion to fetal erythropoiesis while in others the emergence of cells containing Hb F appears to be part of a rapid regeneration process occurring after a period of marrow aplasia. The diagnostic and prognostic value of these observations is discussed.

Adult↗