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Biomedical subjects

J Speer

Publications and source records attributed to J Speer.

At least 19 recordsLinked to original sources
PubMed2001

Evidence for a Soft Nuclear Equation-of-State from Kaon Production in Heavy-Ion Collisions.

The production of pions and kaons has been measured in 197Au+197Au collisions at beam energies from 0.6 to 1.5A GeV with the kaon spectrometer at SIS/GSI. The K+ meson multiplicity per nucleon is enhanced in Au+Au collisions by factors up to 6 relative to C+C reactions, whereas the corresponding pion ratio is reduced. The ratio of the K+ meson excitation functions for Au+Au and C+C collisions increases with decreasing beam energy. This behavior is expected for a soft nuclear equation-of-state.

Journal Article↗
PubMed2000

Emission pattern of high-energy pions: A new probe for the early phase of heavy-Ion collisions

The emission pattern of charged pions has been measured in Au+Au collisions at 1 GeV/nucleon incident energy. In peripheral collisions and at target rapidities, high-energy pions are emitted preferentially towards the target spectator matter. In contrast, low-energy pions are emitted predominantly in the opposite direction. The corresponding azimuthal anisotropy is explained by the interaction of pions with projectile and target spectator matter. This interaction with the spectator matter causes an effective shadowing which varies with time during the reaction. Our observations show that high-energy pions stem from the early stage of the collision whereas low-energy pions freeze out later.

Journal Article↗
PubMed1996

[Cochlear implants].

Cochlear implantation is a method of utmost importance recently employed in ear surgery. It makes even speech understanding possible with electrical stimulation of the inner ear in case of bilateral total deafness of cochlear origin. The authors have performed cochlear implantation for 10 years at the Ear-Nose and Throat Clinic of Semmelweis University. Since 1985 different implantation techniques have been used in case of 58 patients, both adults and children. The authors give account of of technical details, rapidly changing selection criteria and the call attention to the problems of peri- and postoperative period and rehabilitation, on they basis of their own results. Importance of team-work of the ear-surgeon, audiologist, psychologist, physicist and speech-therapist is emphasized, because success of the operation is based on proper selection, skillful operating techniques and postoperative rehabilitation, as well.

Cochlear Implants↗
PubMed1989

Etoposide combined with cyclophosphamide plus vincristine compared with doxorubicin plus cyclophosphamide plus vincristine and with high-dose cyclophosphamide plus vincristine in the treatment of small-cell carcinoma of the lung: a randomized trial of the Bristol Lung Cancer Study Group.

A total of 353 patients with previously untreated small-cell lung cancer (SCLC) were accrued in this multicenter trial. Patients were randomly assigned to receive one of the following three regimens: cyclophosphamide 1,000 mg/m2 intravenously (IV) day 1, vincristine 1.4 mg/m2 IV day 1, and etoposide 50 mg/m2 IV day 1, followed by etoposide 100 mg/m2/day orally days 2 through 5 (CEV); cyclophosphamide 1,000 mg/m2 IV day 1, vincristine 1.4 mg/m2 IV day 1, and doxorubicin 50 mg/m2 IV day 1 (CAV); cyclophosphamide 2,000 mg/m2 day 1 and vincristine 1.4 mg/m2 IV day 1 (CV). Cycles were repeated every 3 weeks. Treatment groups were comparable with respect to extent of disease, age, sex, performance status, and metastatic sites. No significant differences in response rates, response duration, or survival could be detected in limited disease, although there appeared to be a trend favoring CEV. Among extensive-disease patients, response duration on the CEV regimen was longer than on the CV regimen or the CAV program (P less than .001). The superiority of the CEV regimen was also demonstrated in the survival analysis in which differences attained statistical significance (P = .01). In this group the median survival was increased from 29 weeks on CV to 31 weeks on CAV and 39 weeks on CEV. Myelosuppression was the most frequent toxicity. It was more severe with CV than CEV or CAV. Most nonhematologic side effects were comparable among the three treatment groups. However, the high doses of cyclophosphamide in the CV regimen produced a higher incidence of hemorrhagic cystitis than in the CEV or CAV programs (P less than .001). Cardiotoxicity only occurred in the CAV group (P = .05). The addition of etoposide to the CV regimen resulted in significantly longer response duration and survival without increased toxicity. Similarly, the substitution of etoposide for the doxorubicin in the CAV regimen was associated with prolonged survival and reduced cardiotoxicity.

Adult↗
PubMed1989

Prenatal diagnosis of Duchenne muscular dystrophy: prospective linkage analysis and retrospective dystrophin cDNA analysis.

The accuracy of DNA-based prenatal diagnosis of Duchenne muscular dystrophy (DMD) was determined by study of 174 families. Only 60% of families had a living affected male, and 63% had history of a single affected male. Prenatal diagnosis was declined by 47% of mothers whose DNA studies predicted a carrier risk below 2%, and none have had affected sons. Fetal risk was estimated prospectively by linkage analysis using intragenic and flanking RFLPs and retrospectively using dystrophin cDNA analysis for families whose linkage estimates lacked precision. Diagnostic accuracy was determined by comparing predictions with 40 male pregnancy outcomes. On the basis of linkage analysis, we anticipated 3.2 DMD males and observed 3.0. Retrospective cDNA analysis identified deletions in 2 of these 3 males. The combined use of linkage and cDNA deletion analysis provided a highly accurate method for prenatal diagnosis of DMD.

DNA↗
PubMed1986

Prognostic factors for survival of 194 patients with low infiltrate leukemia.

Prognostic factors were identified from the histories of 194 patients diagnosed as having low infiltrate leukemia (LIL) between 1973 and 1981, when the policy was to delay treatment until there was evidence of progressive disease or life-threatening morbidity. Their median age was 59 yr; 63% were male; 30 had had a malignant disease previously. Presenting symptoms included anemia, 82%; infections, 15%; and hemorrhage, 16%. The group's median survival was 42 weeks, with high marrow cellularity and percentage of blasts, impairment of bone marrow, liver or renal function, age over 65 yr and performance status less than 80% associated with poorer survival. Cytogenetic changes associated with poor survival included loss of chromosome 5 or 7, additional chromosome 8, karyotypic instability, and presence of 100% abnormal metaphases. A regression model including terms for blood and bone marrow features, and age at hospital admission was able to stratify patients into prognostic groups in the same population and in an independent population admitted prior to 1973. Further prospective testing of the model is required. Twenty-six of the 78 patients who were eventually treated with combination chemotherapy achieved complete remission. The presence of Auer rods, diagnosis of acute leukemia or refractory anemia with excess blasts, rapid increase in marrow infiltrate and favorable cytogenetic karyotype were associated with response. Delaying treatment in all patients was found to have improved only modestly the survival of patients with LIL.

Adolescent↗
PubMed1984

Vindesine in advanced breast cancer, lymphoma and melanoma. A Colorado Clinical Oncology Group study.

Fifty-six patients with advanced metastatic carcinoma of the breast, melanoma and lymphoma were treated with the new vinca alkaloid vindesine in a prospective Phase II study. The dose was 3 mg/M2 by I.V. bolus once a week for a minimum of two doses. Patients who failed to respond to four I.V. doses were treated with 48-h intravenous infusions at a dose of 1.5 mg/M2 per 24 h. Of the 26 evaluable patients with breast cancer, there were only two incomplete responses and four patients who experienced stabilization of disease. Of the 12 evaluable patients with melanoma, no responses were seen with four patients experiencing stabilization of disease. Of the 11 patients with non-Hodgkin's lymphomas, there was one complete remission which persisted for 26 months and two partial remissions. No additional responses were seen when the mode of administration was changed to 48-h infusion in three patients with breast cancer, five patients with melanoma and one patient with lymphoma. Significant toxicities included neutropenia in 24 patients and nausea and vomiting in two patients. There were no drug related deaths. Previously reported experience with vindesine in these tumors is reviewed as well.

Adolescent↗
PubMed1984

Combination chemotherapy with BCNU, vincristine, mitomycin-C and prednisone in refractory breast carcinoma. A pilot study.

21 patients with metastatic breast cancer, refractory to conventional agents, were treated with a combination of BCNU, vincristine, mitomycin-C and prednisone given every 4 weeks. Only three of the nineteen (15.8%) evaluable patients were observed to have a partial remission, whereas four experienced stabilization of tumor. The sites which responded included skin lesions in two patients and a pleural effusion in 1 patient. This combination resulted in moderate to severe thrombocytopenia in five patients, but was otherwise well tolerated. This pilot study therefore suggests that these four agents in the schedule and doses given do not appear to be superior to any of these agents used singly for advanced, refractory breast cancer.

Adenocarcinoma↗
PubMed1979

tRNA breakdown products as markers for cancer.

Seven breakdown products of tRNA were quantitated by high pressure liquid chromatography in urine and were related to the creatinine content. In the urine of 26 of 27 patients with 13 different malignancies, there was an elevation of one or more of these "markers." The levels of excretion vary approximately with the stage of the disease.

Aminoisobutyric Acids↗