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Biomedical subjects

M Mason

Publications and source records attributed to M Mason.

At least 91 records · Page 5Linked to original sources
PubMed1992

Use of carboplatin in germ cell tumors of the testis.

The high cure rate among young men with metastatic testicular germ cell tumors heightens the issue of late treatment toxicity. Conventional combination chemotherapy based on cisplatin can be expected to cure 85% to 90% of patients with metastatic disease; however the cost of this success includes severe treatment side effects, including irreversible renal damage and the risk of neurotoxicity and ototoxicity. Carboplatin was investigated as a replacement for cisplatin in the treatment of these tumors because of its reduced toxicity. The Royal Marsden Hospital pilot studies have included 76 patients treated for metastatic nonseminoma with the combination carboplatin/etoposide/bleomycin between 1984 and 1988. The median follow-up at time of analysis was 24 months. The complete remission rate was 95% and the overall cause-specific survival was 98.5%. Also, 33 patients treated with single-agent carboplatin for advanced metastatic seminoma were followed for a median of 36 months. The actuarial progression-free survival was 79%, and 91% of patients were alive and disease-free. The results of these studies indicate that carboplatin has activity equivalent to cisplatin in germ cell tumors of the testis and is less toxic.

Adolescent↗
PubMed1992

[Effect of primary ovarian insufficiency on the molecular heterogeneity of pituitary gonadotropins].

It is known that hypophysial gonadotropins circulate in different molecular forms which are provided with different biological activity and that the proportion of such varieties keep a relation with the concentrations of estrogens in circulation. In physiological menopause predominate the great molecular forms which have a lesser biological activity and when estrogens are administrated a change is produced to smaller molecular forms. The present study tries to determine if in cases of ovarian insufficiency of long duration as in precocious menopause and the syndrome of refractory ovary the chromatographic conduct of gonadotropin is similar. Six patients with precocious menopause, and three with the syndrome of refractory ovary, were studied, in order to make a comparison of chromatographic pattern of FSF and LH in serum, with the one found in women with normal ovarian function and with physiologic menopause. The chromatographic analysis was done by filtration in gel of the serum and the subsequent determination of LH and FSH by RIA of double antibody. It was found that the chromatographic pattern of patients with ovarian insufficiency of long duration, characteristically presents larger molecular forms, specially in the refractory ovary syndrome with a greater alteration in the profile of LH. With base on these results it is concluded that the duration of ovarian insufficiency determine the type of molecular form, predominant, of gonadotropins. Also it is suggested that for the syndrome of refractory ovary, the greater heterogenicity of gonadotropins may explain part of physiopathogeny.

Adult↗
PubMed1992

On the use of historical control data to estimate dose response trends in quantal bioassay.

New tests for trend in proportions, in the presence of historical control data, are proposed. One such test is a simple score statistic based on a binomial likelihood for the "current" study and beta-binomial likelihoods for each historical control series. A closely related trend statistic based on estimating equations is also proposed. Trend statistics that allow overdispersed proportions in the current study are also developed, including a version of Tarone's (1982, Biometrics 38, 215-220) test that acknowledges sampling variation in the beta distribution parameters, and a trend statistic based on estimating equations. Each such trend test is evaluated with respect to size and power under both binomial and beta-binomial sampling conditions for the current study, and illustrations are provided.

Analysis of Variance↗
PubMed1991

Microdissection of chromosome band 11p15.5: characterization of probes mapping distal to the HBBC locus.

Both cytogenetic and molecular genetic analyses of the 11p15.5 subband suggest it may contain loci important in the genesis of a wide variety of tumors such as rhabdomyosarcomas and Wilms' tumors as well as the congenital tumors associated with the Beckwith-Wiedemann syndrome. As a first step in further defining the involvement of this chromosomal region in these various maladies, a library was constructed from the specific microdissection of chromosomal fragments representing 11p15.5-pter. Of 98 microclones analyzed, 31 identified single copy human DNA sequences, 21 of which mapped to 11p15.5 while 10 mapped proximal to the HBBC locus. Five of the 11p15.5-positioned microprobes detected restriction fragment length polymorphisms at their homologous genomic loci for various enzymes. These microprobes are now being utilized in several ways in order to address the underlying basis of the Beckwith-Wiedemann syndrome and its associated tumors.

Animals↗
PubMed1991

Effectiveness of carboplatin, etoposide, and bleomycin combination chemotherapy in good-prognosis metastatic testicular nonseminomatous germ cell tumors.

The combination of carboplatin, etoposide, and bleomycin (CEB) was evaluated as initial chemotherapy in 76 patients with good-prognosis metastatic nonseminomatous germ cell tumors (NSGCT) between 1984 and 1988. The classification of eligible patients included Royal Marsden Hospital (RMH) stages IM, IIA, IIB, IIC, IIIA, IIIB, IV0ABCL1, and IV0ABL2. Four courses of combination chemotherapy were administered in a 21-day cycle, and surgical excision of residual mass was performed in 27 cases (23 laparotomies and four thoracotomies). At the time of analysis, median follow-up was 24 months from start of chemotherapy (range, 6 to 54 months). The 2-year cause-specific survival probability was 98.5%, the single cause-related mortality being caused by bleomycin pneumonitis. Five patients failed CEB chemotherapy, but all have been successfully salvaged with a combination of surgery and intensive chemotherapy, follow-up from completion of all treatment being 35 to 44 months. The toxicity of CEB included bone marrow suppression and alopecia in all patients but no significant neurotoxicity or ototoxicity, and minimal renal toxicity. Only four (5%) patients had a decrease in the glomerular filtration rate greater than 15%. In 51% of patients, the hemoglobin fell below 10 g/dL. The WBC count nadir was less than 1,500/microL in 11% of treatment cycles and in 16% the platelet nadir fell below 50,000/microL. Decreases in the WBC and platelet counts were of very brief duration. Only one of 310 CEB cycles was complicated by neutropenic sepsis, and there were no episodes of thrombocytopenic purpura or bleeding. We conclude that the CEB combination represents an effective alternative to cisplatin-based chemotherapy in good-prognosis NSGCT and that the replacement of cisplatin by carboplatin leads to reduced toxicity.

Adolescent↗
PubMed1991

Impact of chemical dependency on family health status.

Previous discussions of the relationship between chemical dependency and family health have been based primarily on clinical observations and on the perceptions of family members rather than on research evidence. In order to systematically document the relationship, this study compared family medical insurance claims 2 years prior to and 2 years following the year in which a family member completed a chemical dependency treatment program. Results indicate a significant decrease in claims following the family member's completion of treatment, thus suggesting a relationship between the chemical dependency of one family member and the health status of other family members.

Adult↗
PubMed1988

Neurosensory disturbance associated with the anterior mandibular horizontal osteotomy.

Fifteen patients who underwent an anterior mandibular horizontal osteotomy (genioplasty) were retrospectively studied by neurosensory testing to evaluate light touch (LT) and temperature (T) discrimination. Testing was conducted using the two-alternative forced choice method. Density of a neurosensory disturbance (NSD), when it occurred, was also evaluated. A questionnaire was administered to determine if patients with a NSD perceived that their quality of life was adversely affected. The incidence of NSD was 3.4% (one of 30) to LT and 0% (none of 30) to T. The one abnormal mental nerve with a NSD to LT was moderately dense, but was not perceived by the patient as adversely affecting her quality of life.

Adolescent↗
PubMed1988

Analysis of cell-differentiation lineage in human teratomas using new monoclonal antibodies to cytostructural antigens of embryonal carcinoma cells.

Human embryonal carcinoma cells sometimes display the developmental potential of early embryonic stem cells. While available data do not clearly identify a counterpart of these tumor cells in normal development, previous comparisons of human embryonal carcinoma and yolk sac carcinomas indicated that these cell types are closely related, and suggested that embryonal carcinoma cells might resemble the progenitors of extraembryonic endoderm. To analyse further cell-differentiation lineage in these tumors, we produced monoclonal antibodies to cytostructurally associated antigens of human embryonal carcinoma cells. Spleen cells from mice immunized with a detergent-insoluble extract of cultured human embryonal carcinoma cells were fused to NS-1 myeloma cells, and hybridoma supernatants were screened by indirect immunofluorescence on the immunizing cell line, then on a panel of cell lines derived from human embryonal carcinomas, yolk sac carcinomas, and a range of neoplastic and normal tissues. Monoclonal antibody GCTM-1 stained the nuclei of all human cells tested and served as a positive control; this antibody immunoprecipitated proteins of 85 and 66 k Da from human embryonal carcinoma cells. GCTM-2 recognized an epitope on a 200-k Da extracellular protein present on the surface of embryonal carcinoma cells, and stained the surface of visceral yolk sac-type carcinoma and colorectal carcinoma cells as well. Enzymatic analysis of carbohydrate residues on the GCTM-2 antigen revealed that it was a keratan sulphate proteoglycan, and suggested that the epitope recognized by the antibody lies on the core protein. In immunoblots, antibody GCTM-3 bound to a 57-k Da cytoskeletal protein expressed in human embryonal carcinoma. This antibody decorated filamentous arrays in cell lines from human embryonal carcinoma, visceral yolk sac carcinoma, parietal yolk sac carcinoma (endodermal sinus tumour), and adenocarcinoma and large cell carcinoma of the lung. Antibody GCTM-4 recognized a determinant present on a 69-k Da polypeptide, associated with a component of the lysosomal compartment, which was expressed in embryonal carcinoma cells, but no other cell type tested. The results with this antibody panel thus allow distinction between human embryonal carcinoma and yolk sac carcinoma, but provide further evidence of a close relationship between these cell types.

Animals↗
PubMed1988

Catheter-associated Candida utilis fungemia in a patient with acquired immunodeficiency syndrome: species verification with a molecular probe.

Candida utilis was cultured from the blood of a patient with acquired immunodeficiency syndrome. The candidemia was apparently associated with catheter implantation. The isolate was identified initially by standard methods and verified by molecular probing. The pattern of actin-specific restriction fragments obtained from the DNA of the isolate, probed with C. albicans actin sequences, corresponded to that of C. utilis. This organism adds to the growing list of Candida species associated with human disease. Molecular probing offers a definitive identification when an unexpected etiological agent is found.

Acquired Immunodeficiency Syndrome↗
PubMed1987

An evaluation of case management.

This project explores the efficiency and effectiveness of case management as compared with the usual and customary services available to chronic mentally ill individuals in reducing readmissions to mental hospitals and improving the quality of life. A randomized pretest-posttest control group design was used to assign 417 individuals who had at least two discharges from a mental hospital to an experimental (E) group (N = 213) to receive case management services and a control (C) group (N = 204) who could receive any services but case management. After participation in the project for 12 months, 138 members of the E group and 126 members of the C group were reinterviewed. The E group received more services, cost more to maintain, and were admitted to mental hospitals more often, but concomitant improvement in quality of life indicators was not evident. Alternative explanations for the findings are discussed.

Activities of Daily Living↗
PubMed1987

Treatment strategies for self-injurious behavior in a large service-delivery network.

Despite pressures in recent years to discourage reliance upon pharmacological interventions, psychoactive drugs continue to be utilized extensively with institutionalized mentally retarded persons. In the present study the scope and pattern of psychoactive drug use within a state-wide institutional service-delivery network were examined, with a focus upon its role in the treatment of self-injurious behavior (SIB) and other aberrant behavior patterns. Correlates to psychoactive drugs and alternative intervention approaches were examined. Lack of treatment, insufficient utilization of behavioral technology, and use of physical and chemical restraints as adjuncts to positive behavioral programs were indicated.

Adult↗