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Biomedical subjects

P Ruff

Publications and source records attributed to P Ruff.

At least 37 records · Page 2Linked to original sources
PubMed1996

A phase II study of cisplatin/ifosfamide in recurrent/metastatic undifferentiated nasopharyngeal carcinoma among young blacks in southern Africa.

Recurrent/metastatic, undifferentiated nasopharyngeal carcinoma (UDNPC) is known to be chemosensitive but has rarely been studied in Phase II methodology. No studies concerning its chemoresponsiveness among southern Africans have been demonstrated to date. From 1990 through 1994, 18 African patients from the Johannesburg metropolitan area with recurrent (following radiotherapy failure) or primarily metastatic (bone) UDNPC were treated with ifosfamide (3 g/m), mesna, and cisplatin (50 mg/m) for 2 days. Three patients (15%) attained complete remission and eight (44%) partial remission, yielding an overall response rate of 59%. Median response duration was 28 weeks. Two patients (11%) had stable disease with symptomatic improvement and five (30%) progressed on therapy. Treatment was generally well tolerated but there was one treatment-related death (neutropenic sepsis). The combination of ifosfamide/cisplatin appears to be promising in UDNPC commonly seen in young patients in southern Africa. However, the duration of response still tends to be brief.

Adolescent↗
PubMed1996

Molecular analysis of a silent polymorphism in the PDZ domain of p55, the major palmitoylated erythrocyte membrane protein.

Two independently published cDNA sequences of p55, the X-linked major palmitoylated erythrocyte membrane protein, revealed a discrepancy between G and T at position 358 (Genbank: M64925). This results in codon 85, in exon 3 in the PDZ (PSD-95, discs-large, Z0-1) domain, being either ACG or ACT. As both ACG and ACT code for threonine, this represents a silent polymorphism. Polymerase chain reaction (PCR), single-stranded conformational polymorphism (SSCP), and direct-sequencing analysis of exon 3 of the p55 gene was performed in 98 subjects of African and European origin. Of the 70 females studied, the frequency of G versus T at position 358 was 0.76:0.24, while of the 28 males, 16 had a G and 12 a T at position 358 (0.57:0.43). In subjects of African origin, the frequency of G versus T at position 358 was 0.78:0.22; in subjects of European origin the ratio was 0.63:0.37.

Blood Proteins↗
PubMed1995

Patterns of clonal evolution in transformed chronic myelogenous leukemia.

Chronic myelogenous leukemia (CML) is an initially indolent disease which transforms into an acute leukemia about 2-5 years after diagnosis. We report a series of 75 patients, from a total of 125 patients with CML, who underwent acute blastic transformation. These included four unclassified, 10 lymphoid, and 61 non-lymphoid acute leukemias, including 54 myeloblastic, three promyelocytic, one myelomonocytic, one erythroblastic, and two megakaryoblastic leukemias. Fifty-two patients developed new cytogenetic abnormalities in addition to being Ph positive. These included trisomies of chromosomes 8, 19, and 21, isochromosome of the long arm of chromosome 17 (i(17q)), double and triple Ph, as well as other translocations, deletions, and additions. The overall median survival once the diagnosis of acute blast crisis was made was 61 days.

Adult↗
PubMed1994

Radiation therapy in an elderly African population with Kaposi's sarcoma.

There are no published studies on the efficacy of modern radiation therapy in elderly populations with the endemic African type of Kaposi's sarcoma (AKS). The present retrospective analysis of 20 elderly AKS patients treated by radiotherapy attempts to supply information relevant to the older age group. It demonstrates that excellent symptomatic relief with minimal side effects can be attained and suggests that the role of radiotherapy as the treatment of choice in this particular group should be emphasized.

Africa↗
PubMed1994

Lymphoproliferative malignancies in association with endemic African Kaposi's sarcoma.

The association of classical Kaposi's sarcoma with lymphoproliferative disorders is well known. However, far less is known about lymphoproliferative malignancies in endemic African Kaposi's sarcoma. A review of 47 patients with the endemic type of Kapos's sarcoma treated at the Johannesburg Teaching Hospital Complex between 1980 and 1992 revealed four patients (8.5 pc) in whom Kaposi's sarcoma was associated with a malignant lymphoma. Possible pathogenetic mechanisms are suggested and the current literature is reviewed.

Adult↗
PubMed1993

Radiation therapy in endemic (African) Kaposi's sarcoma.

PURPOSE: Evaluating the role of radiation therapy in the treatment of the endemic, African variant of Kaposi's sarcoma. A retrospective analysis. METHODS AND MATERIALS: Between 1978 and 1990, 28 symptomatic African patients with the African Human Immunodeficiency Virus negative type of Kaposi's sarcoma were referred to the Johannesburg General Hospital. Following staging, all patients were treated with radiation therapy. Doses ranged between 8-10 Gy (single fraction) or 14-24 Gy fractionated over 1-3 weeks. RESULTS: Complete and partial regression of cutaneous lesions was achieved in 9 (32%) and 15 (54%) patients, retrospectively. A complete/near-complete alleviation of symptoms was achieved in all patients. Response rate and duration of response was not influenced by age, radiation modality or schedule. Side effects were minimal. CONCLUSION: Our study emphasizes the high radiosensitivity of the endemic, African type of Kaposi's sarcoma, indicating its usefulness as the treatment of choice for this disease.

HIV Seronegativity↗
PubMed1993

Cloning of human erythroid dematin reveals another member of the villin family.

Dematin is an actin-bundling protein originally identified in the human erythroid membrane skeleton. Its actin-bundling activity is abolished upon phosphorylation by the cAMP-dependent protein kinase and is restored after dephosphorylation. Here we report the complete primary structure of human erythroid dematin, whose sequence includes a homologue of the "headpiece" sequence found at the C terminus of villin. This headpiece is essential for villin function in inducing microvillar development and actin redistribution. The widespread expression of dematin transcripts in human tissues suggests that dematin and its homologues may substitute for villin in villin-negative tissues to regulate actin reorganization by a phosphorylation-regulated mechanism.

Actins↗
PubMed1993

[Thoracoscopic lung biopsy in diagnosis of interstitial lung diseases].

Thoracoscopic lung biopsy is accepted to be an appropriate method in diagnosing interstitial lung diseases when lung tissue examination is needed for accurate diagnosis. In our study of 30 patients with chronic interstitial lung diseases a high sensitivity of 97% was reached similar to the yield reported from open lung biopsy techniques. The manyfold described handicap of long lasting pleural fistula after thoracoscopic biopsies could be prevented in most cases by sealing the biopsy site with a fibrin layer. Thus the mean pleural drainage-time was reduced to 3.7 +/- 1.0 days and only 3 out of the 30 patients required a prolonged drainage up to 11 days. There were only a few minor complications except in one patient who developed an etiologically unclear pulmonary edema shortly after the procedure. However the results obtained by this modified bioptic technique are encouraging and confirm again the efficacy and safety of thoracoscopic lung biopsy in diagnosing interstitial lung diseases.

Biopsy↗
PubMed1991

Molecular identification of a major palmitoylated erythrocyte membrane protein containing the src homology 3 motif.

The complete amino acid sequence of a 55-kDa erythrocyte membrane protein was deduced from cDNA clones isolated from a human reticulocyte library. This protein, p55, is copurified during the isolation of dematin, an actin-bundling protein of the erythrocyte membrane cytoskeleton. Fractions enriched in p55 also contain protein kinase activity that completely abolishes the actin-bundling property of purified dematin in vitro. The predicted amino acid sequence of p55 does not contain any consensus sequence corresponding to the catalytic domains of protein kinases but does contain a conserved sequence found in the noncatalytic domains of oncogene-encoded tyrosine kinases. This conserved src homology 3 (SH-3) motif appears to suppress the tyrosine kinase activity of various oncoproteins and has also been found in several plasma membrane associated proteins involved in signal transduction. Northern blot analysis indicated that p55 mRNA was constitutively expressed during erythropoiesis and underwent 2-fold amplification after induction of K562 erythroleukemia cells toward the erythropoietic lineage. The abundant expression of p55 mRNA, along with protein 4.1 mRNA, was evident in terminally differentiated human reticulocytes. Although p55 has many features consistent with known peripheral membrane proteins, its tight association with the plasma membrane is reminiscent of an integral membrane protein. This fact may be partly explained by the observation that p55 is the most extensively palmitoylated protein of the erythrocyte membrane.

Amino Acid Sequence↗
PubMed1991

Malaria and ovalocytosis--molecular mimicry?

Two recently published reports have described findings which will have a profound impact on the understanding of molecular mechanisms of human resistance to malaria infection. In Melanesian ovalocytosis, a genetic polymorphism found in Papua New Guinea and parts of South East Asia, the red cells are highly resistant to invasion by various species of malaria parasite. The molecular nature of the defect in ovalocytic erythrocytes was not known. Recent reports by Liu et al. (Liu, S.-C., Zhai, S., Palek, J., Golan, D., Amato, D., Hassan, K., Nurse, G., Babona, D., Coetzer, T., Jarolim, P. Zaik, M. and Borwein, S. (1990) N. Engl. J. Med. 323, 1530-1538.) and Jones et al. (Jones, G.L., Edmundson, H.M., Wesche, D. and Saul, A. (1991) Biochim. Biophys. Acta 1096, 33-40.) have now identified the abnormality in the band 3 protein of ovalocytic red cell membranes. A major discovery in the Jones et al. study is the presence of an extended peptide at the N-terminus of ovalocyte band 3 protein. This novel 13 amino acid extended sequence is not found in the primary structure of normal band 3 protein and was suggested to be the cause of band 3 defect in ovalocytes. We have analyzed this extended sequence through Genbank using SWISS-PROT database and found that an almost identical sequence exists in a malaria parasite protein called RESA.

Amino Acid Sequence↗
PubMed1990

cDNA sequence for human erythrocyte ankyrin.

The cDNA for human erythrocyte ankyrin has been isolated from a series of overlapping clones obtained from a reticulocyte cDNA library. The composite cDNA sequence has a large open reading frame of 5636 base pairs (bp) with the complete coding sequence for a polypeptide of 1879 amino acids with a predicted molecular mass of 206 kDa. The derived amino acid sequence contained 194 residues that were identical to those obtained by direct amino acid sequencing of 11 ankyrin proteolytic peptides. The primary sequence contained 23 highly homologous repeat units of 33 amino acids within the 90-kDa band 3 binding domain. Two cDNA clones showed evidence of apparent mRNA processing, resulting in the deletions of 486 bp and 135 bp, respectively. The 486-bp deletion resulted in the removal of a 16-kDa highly acidic peptide, and the smaller deletion had the effect of altering the COOH terminus of the molecule. Radiolabeled ankyrin cDNAs recognized two erythroid message sizes by RNA blot analysis, one of which was predominantly associated with early erythroid cell types. An ankyrin message was also observed in RNA from the human cerebellum by the same method. The ankyrin gene is assigned to chromosome 8 using genomic DNA from a panel of sorted human chromosomes.

Amino Acid Sequence↗
PubMed1989

Precursor T-cell lymphoma associated with human immunodeficiency virus type 1 (HIV-1) infection. First reported case.

The majority of lymphomas that develop in human immunodeficiency virus type 1 (HIV-1) positive patients have a B-cell phenotype, with few reported cases of T-cell lymphoma. Within the latter group, those that have been comprehensively phenotyped had a mature helper T-cell phenotype (CD4+). We report, for the first time, an HIV-1 positive patient with a precursor T-cell lymphoma (CD7+,CD1-,CD3-,CD4-, and CD8-). T-cell receptor beta and gamma genes were in the germline configuration and integration of HIV-1 DNA could not be detected in the lymphoma cell genome.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Sequential hormonal therapy and sequential hormonal and chemotherapy for advanced prostatic cancer.

Ninety-two patients with D2 prostatic cancer were studied. Initial treatment was with either diethylstilboestrol (DES) or orchidectomy. Response to DES (5/63, 81%) was significantly higher than for orchidectomy (18/29, 62%; p less than 0.01). However, duration of response and duration of survival were not significantly different for the 2 forms of hormonal therapy. Fifty-seven patients were randomised to receive second-line treatment with either medroxyprogesterone acetate (MPA), oral chlorambucil or combination chemotherapy (adriamycin + cyclophosphamide + 5-fluoro-uracil). Response to second-line treatment was similar for all 3 regimens (46% overall response). Most of the responses were disease stabilisation and, although there was symptomatic benefit, response to second-line therapy did not significantly improve survival compared to the survival experience of the group as a whole. It is concluded that palliative second-line treatment for advanced prostatic cancer should consist of the least toxic form of treatment which in this study was second-line hormone administration (MPA).

Adenocarcinoma↗
PubMed1989

Intraperitoneal chemotherapy in peritoneal malignancy: impact of intensive system care on practicability.

In a group of 31 patients a port-a-cath-system for intraperitoneal chemotherapy was installed. From 23 evaluable patients 9 showed a tumor remission, but only 1 was a patient with gastrointestinal carcinoma. All others were patients with ovarial carcinoma. The median survival rate of all patients was 9 months after implantation of the intraperitoneal catheter. 50% of all patients with gastrointestinal carcinoma died within the first 6 months, only 1 of 11 patients with ovarial carcinoma died in this period.

Adult↗
PubMed1987

Abnormalities of chromosome 12p13 and malignant proliferation of eosinophils: a nonrandom association.

Four patients representing a spectrum of haematological malignancies are reported. Two patients had Philadelphia chromosome negative myeloproliferative disorders, one had acute lymphoblastic leukaemia and one had eosinophilic leukaemia. In each case eosinophilia was present and demonstrated to be part of the malignancy by the association of clonally abnormal metaphases with eosinophil granules. Abnormalities involving the short arm of chromosome 12 (12p13) were a constant feature in all four cases and therefore a nonrandom association between this chromosome region and malignant eosinophil proliferation is proposed.

Acute Disease↗
PubMed1985

Factors influencing human IgE synthesis in vitro and in vivo.

Several pitfalls may affect studies on human IgE synthesis in vitro. In this paper, the requirement for stringent specificity of the anti-IgE antibodies used and for assessment not only of IgE detectable in culture supernatants but also as cell-associated IgE is emphasized. The use of cycloheximide-treated cultures as controls also leaves wishes open. Activated, human T cells and T cell hybridomas produce IgE-binding factors, which may be detected by a sensitive in vitro test and which may apparently also become the endeavour of synthesis by molecular biological techniques. Although the evidence available in rodents for the role of IgE-binding factors in modulating IgE synthesis has not yet been fully reproduced by us in man, the fact that classical IgE-enhancing procedures in rodents (e.g. radiotherapy, T cell suppression) also affect IgE production in man leads to believe that similar immunoregulation mechanisms apply to various mammalian species studied so far.

Antibody Formation↗