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Biomedical subjects

R C Young

Publications and source records attributed to R C Young.

At least 19 recordsLinked to original sources

The stereoselective recognition of substrates by phosphoinositide kinases. Studies using synthetic stereoisomers of dipalmitoyl phosphatidylinositol.

Soluble phosphatidylinositol (PtdIns) 4- and 3-kinase activities were partially purified and characterized from human placental extracts. The placental PtdIns 4-kinase (type 3) has a Km for ATP of 460 microM and is kinetically different to a partially purified human erythrocyte, membrane-bound, PtdIns 4-kinase (type 2). These three inositol lipid kinases were then used to compare their substrate specificities against the four synthetic stereoisomers of dipalmitoyl PtdIns. Only the placental 4-kinase was influenced by the chirality of the glycerol moiety of PtdIns. However, neither of the 4-kinases was able to phosphorylate L-PtdIns and, therefore, these kinases have an absolute requirement for the inositol ring to be linked to the glyceryl backbone of the lipid through the D-1 position. Phosphoinositide 3-kinase, on the other hand, was found to phosphorylate both D- and L-PtdIns. While the 3-kinase phosphorylated exclusively the D-3 position of D-PtdIns, further analyses demonstrated that the same enzyme phosphorylated two sites on L-PtdIns, namely the D-6 and D-5 positions of the inositol ring. Some implications of these findings are discussed.

1-Phosphatidylinositol 4-Kinase

Quantitative gas-liquid chromatography of neutral sugars in human serum glycoproteins. Fucose, mannose, and galactose as predictors in ovarian and small cell lung carcinoma.

A precise and accurate gas-liquid chromatographic (GLC) method has been developed for the quantitative analysis of the neutral sugars L-fucose (6-deoxygalactose), mannose, galactose, and glucose in ethanol precipitates of human serum proteins. The chromatographic conditions and sample preparation resulted in short analysis time (20 min per run) and made routine analyses practicable (twelve samples per day). The alditol acetate derivatization yielded single derivatives for each sugar. Complete separation was achieved on a 2.0 m X 2 mm I.D. column with 2.0% Silar-7CP on Chromosorb W AW 80--100 mesh. The results of hydrolysis showed that the release of fucose and galactose preceded the release of mannose. Hydrolysis with AG 50 W-X8 (H+) ion-exchange resin in 0.5 N HCl at 100 degrees for 7 h optimized glycosidic bond cleavage with only minimal destruction of fucose, mannose and galactose. A combination of strong cation- and anion-exchange resin columns was used to remove chromatographic background of peptides, amino acids, amino sugars, and inorganic ions. An average R.S.D. of less than 4% with recovery of greater than 86% for the three sugars was achieved. The homogeneity of the chromatographic peaks for the neutral sugars of normal human serum glycoproteins was confirmed by GLC--mass spectrometry. Significantly elevated ratios of fucose, galactose, and mannose to serum protein were observed for patients with small cell lung and ovarian carcinomas.

Carcinoma

A comparison between combination chemotherapy and total body irradiation plus combination chemotherapy in non-Hodgkin's lymphoma.

Thirty-nine untreated patients with either lymphocytic or nodular mixed/nodular histiocytic non-Hodgkin's lymphoma, stage II--IV, were randomized to treatment with total body irradiation (TBI), 100 rads in 10 fractions over 12 days, plus combination chemotherapy with either cyclophosphamide, vincristine and prednisone (CVP) or cyclophosphamide, vincristine, procarbazine and prednisone (C-MOPP) or to treatment with combination chemotherapy (CVP or C-MOPP) alone. Remission rate and duration was comparable for both treatment groups; thus the use of both treatment modalities ab initio provides no therapeutic advantage.

Adult

Central nervous system complications of non-Hodgkin's lymphoma. The potential role for prophylactic therapy.

In 38 patients with non-Hodgkin's lymphoma, involvement of the central nervous system (CNS) by malignant lymphoma developed during an eight year period. All patients had lymphomatous meningitis; clinical involvement of the spinal nerves or cranial nerves suggested the diagnosis. Spinal fluid was abnormal in 97 per cent of the patients although a positive cytology could be documented in only 67 per cent by lumbar puncture. The histology in 82 per cent of the patients was diffuse. Involvement of the CNS in nodular lymphoma was uncommon (3 per cent), and the histology in virtually all of these patients had converted to diffuse. At the time of diagnosis of CNS disease, 95 per cent of the patients had other evidence of advanced disease; 66 per cent had bone marrow involvement. In only 18 per cent of the patients did CNS disease develop while they were in clinical remission. Eighty-five per cent of the patients treated with whole brain irradiation and intrathecal chemotherapy had a good clinical response. Knowledge of these risk factors permits definition of a group of patients who may benefit from CNS prophylaxis.

Adult

Ovarian cancer: a solid tumor with evidence of normal cellular immune function but abnormal B cell function.

Immunologic assays of B and T lymphocyte function were performed on 21 patients with epithelial ovarian cancer prior to either chemotherapy or radiotherapy. The results were compared to similar studies on 12 age-matched normal women. The total peripheral blood lymphocyte counts, proportion of E rosette positive cells, stimulation of T cells by phytohemagglutinin and concanavalin A, recall skin tests, and the ability to have a primary delayed hypersensitivity response to keyhold limpet hemocyanin did not differ between patients and controls. However, patients with ovarian cancer had statistically significant reduction in surface immunoglobulin positive cells, proliferative response to pokeweed mitogen and primary antibody response to keyhole limpet hemocyanin. In contrast to results in patients with other solid tumors, these data indicate that untreated patients with ovarian cancer have evidence of normal cellular immune function but abnormal B cell function.

Adult

Chemotherapy of Hodgkin's disease.

During the past 10 to 15 years, there have been dramatic improvements in the prognosis of patients with advanced Hodgkin's disease resulting from the development of combination chemotherapy. The long-term follow-up of patients with advanced disease treated with MOPP indicates that 66 per cent of those achieving complete remissions have not relapsed and remain off therapy at five and 10 years follow-up. Attempts to make additions, subtractions or modifications in the MOPP regimen have not generally improved the overall survival rate or reduced the toxicity. Development of non-cross-resistant combinations provides a rational approach to the treatment of primary induction failures and those who relapse after short initial remissions. Alternating sequence induction chemotherapy regimens show considerable promise. The use of combined modality approaches to the treatment of localized IB--IIIB Hodgkin's disease has made a significant impact on disease-free survival but has yet to alter actual survival. Combined modality approaches in advanced disease are encouraging but as yet long-term follow-up is not available to assess their worth vis-à-vis existing therapies for advanced disease. Improved survival has brought about concern over late complications, particularly second malignancies. These complications require careful monitoring and must be balanced against any survival benefit seen from combined modality approaches. However, the fact that patients now survive long enough to be potentially at risk for such long-term complications is a testament to the efficacy of modern day aggressive therapy.

Bleomycin

Therapist A--B score and treatment outcome with psychiatric in patients: a table of random numbers.

The study evaluated the relationship between therapist personality and treatment success for 141 schizophrenics and 94 non-schizophrenics randomly assigned to short or long hospitalization. The 47 therapists were self-rated on the Whitehorn--Betz A--B scale in both the original and the Campbell versions. Outcome was assessed on the Health--Sickness Rating Scale and the Psychiatric Evaluation Form at discharge and at 1 and 2 year follow-up. The hypothesis of greater success for A--type therapists with schizophrenics was not confirmed, nor were alternative relationships evident in the data.

Affective Symptoms

Localization of the immune response in sarcoidosis.

Pulmonary sarcoidosis is an interstitial disease characterized by granulomas within the lung parenchyma, anergy to a variety of skin tests, and decreased numbers of circulating T-lymphocytes. To evaluate the effector cell populations present at sites of disease in patients with active pulmonary sarcoidosis, inflammatory and immune effector cells were isolated from lung via bronchoalveolar lavage and compared to comparable cell populations from the peripheral blood of the same patients and similar cell populations of normal subjects and patients with idiopathic pulmonary fibrosis. Patients with sarcoidosis had a marked increase in the percentage of T-lymphocytes in the lung despite a significant peripheral blood T-lymphocytopenia. In addition, many of these T-lymphocytes demonstrated surface marker characteristics associated with lymphocyte activation, and they spontaneously secreted leukocyte inhibitory factor. In contrast to patients with sarcoidosis, normal subjects and patients with idiopathic pulmonary fibrosis had similar percentages of T-lymphocytes in lung and blood, and there was no evidence for T-lymphocyte activation. Analysis of lymphocytes in uninvolved marrow from 7 of 8 patients with sarcoidosis revealed proportions of T-lymphocytes similar to those in the marrows of normal subjects and patients with idiopathic pulmonary fibrosis. In comparison, one patient with sarcoidosis had large numbers of T-lymphocytes in bone marrow, but only in areas where there were granulomas in the marrow. These studies suggest that: (1) the alveolitis of pulmonary sarcoidosis is characterized by large numbers of activated T-lymphocytes, and (2) there is an anatomic localization of the immune response in sarcoidosis in that analysis of uninvolved tissues such as peripheral blood may not reflect local immune responses at sites of granuloma formation.

Adult

Prolonged disease-free survival in Hodgkin's disease with MOPP reinduction after first relapse.

Thirty-two patients with Hodgkin's disease who relapsed after a first complete remission induced by nitrogen mustard, vincristine, procarbazine, and prednisone (MOPP) were retreated with MOPP chemotherapy. Nineteen patients achieved a second complete remission. Median duration of the second complete remission was 21 months. The likelihood of achieving a second complete response could be predicted by the duration of the first response. Fourteen of 15 patients whose first complete remission was longer than 12 months achieved a second complete response in contrast to five of 17 patients whose initial complete remission lasted less than 12 months (P less than 0.001). Median survival of all patients in this study who were re-treated with MOPP was longer than 4 years after their first relapse. We conclude that patients with Hodgkin's disease who relapse after a first complete remission induced by MOPP are not necessarily resistant to further MOPP therapy and can achieve long-term survival with MOPP reinduction.

Adolescent

Histologic grade in advanced ovarian cancer.

The histologic grade of epithelial ovarian tumors was found to be a major prognostic factor for survival in patients with advanced (stage III-IV) disease. In addition, a grading system based on cytologic detail (modified Broders' grades I-IV) identified groups with a differential response to chemotherapy. The overall improvement in survival observed with combination chemotherapy was related primarily to an increased survival of patients with grade II and III lesions. Although the survival of patients with grade I lesions was markedly better than for patients with grade IV lesions, in neither case was it influenced by the choice of single-agent or combination chemotherapy. In prospective clinical trials in advanced disease, modified Broders' grades should be included as a separate stratification factor.

Altretamine

Treatment of osteogenic sarcoma. I. Effect of adjuvant high-dose methotrexate after amputation.

Thirty-nine patients with extremity osteogenic sarcoma and no discernible metastases were treated with amputation and postoperative adjuvant high-dose methotrexate with leucovorin rescue. One half of the patients were also randomized to receive bacillus Calmette-Guérin by a multiple-puncture technique. Results have been analyzed with a minimum followup of 10 months and a median followup of 27 months. Actuarial analysis estimates that 38% of current protocol patients remain continuously free of disease for 24 months compared to only 17.4% of historical control patients (P = 0.029; one-sided generalized Kruskal-Wallis test). Bacillus Calmette-Guérin administered by a multiple-puncture technique had no effect on disease-free interval. Minor differences between current protocol and historical control patients with regard to race, age, histologic type, and site and size of primary tumors do not affect the difference in disease-free interval between these two patient groups. However, current patients had somewhat lower grade lesions and consideration of the patients with grade III and IV lesions only, lessens the difference between current and historical control patients (P = 0.11; one-sided generalized Kruskal-Wallis test). High-dose methotrexate was administered with virtually no morbidity and no deaths. The small differences observed in this study between protocol patients treated with surgery plus high-dose methotrexate and historical control patients treated with surgery alone point to the need for a prospective randomized study to establish the role of high-dose methotrexate in the adjuvant treatment of patients with osteogenic sarcoma.

Adolescent

Respiratory effects of a single, moderately acute, smoke inhalation episode.

Twenty-three hospital employees who suffered ill effects of smoke inhalation were pulmonary-function tested within 72 hours, after ten weeks, and again after 45 weeks of exposure. Four nonexposed control subjects were selected for comparison of data.Exposed persons commonly had restrictive lung disease which may have resulted from stimulation of irritant receptors in bronchi and/or interstitial edema of chemical injury at the level of the ventilation-perfusion unit. Airways obstruction was infrequent, despite the possibility of inhalation of di-isocyanates, an intermediary product of burning polyurethane foam that may cause chemical asthma. Eye and constitutional symptoms were also frequent.Clinical recovery was as a rule rapid and complete (within a week), but physiologic recovery was protracted (over 45 weeks in some cases). Most surprisingly, cigarette smoking and/or presence of cardiopulmonary disease did not contribute to morbidity.

Acute Disease