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Biomedical subjects

R C Young

Publications and source records attributed to R C Young.

At least 163 records · Page 9Linked to original sources
PubMed1989

Short-term effects of smoking cessation: benefit or penalty?

Eight of ten cigarette smokers successful in a smoking cessation group therapy program were examined, initially, and at six and 12 months postcessation. Examination included completion of a respiratory questionnaire and selective pulmonary function testing that included maximum expiratory flow volume curves, slope of phase 3 alveolar plateau, and closing volume. Two symptomatic subjects became symptom-free within six months postcessation. Results indicate a mean weight gain of 4.1 kg within 12 months (P less than 0.01), deterioration in mean forced expiratory volume in one second as percent of forced vital capacity (P less than 0.05), and deterioration in mean forced expiratory volume in three seconds as percent of forced vital capacity postcessation (P less than 0.05). Other tests derived from the maximum expiratory flow-volume curve, slope of phase 3, or closing volume showed no change. These results may be explained by a number of factors and may have implications for future studies.

Adult↗
PubMed1988

High-dose carboplatin with diethyldithiocarbamate chemoprotection in treatment of women with relapsed ovarian cancer.

Diethyldithiocarbamate (DDTC) has been found to protect the bone marrow, kidneys, and gastrointestinal tract from the toxic effects of cisplatin and carboplatin (CBDCA) in animal models. In an attempt to minimize the toxic effects of high-dose CBDCA (800 mg/m2), a pilot study was undertaken in which women with relapsed or refractory epithelial ovarian cancer were treated with high-dose CBDCA, which was followed 3 hours later with DDTC (4 g/m2). There were four partial responses and no complete response in 21 patients who could be evaluated (overall response rate, 19%). Significant toxic effects, including three treatment-related deaths, were associated with the regimen. This study suggests that while high-dose CBDCA plus DDTC may be active in relapsed or refractory ovarian cancer, it is associated with clinically significant hematologic and autonomic toxic effects.

Adult↗
PubMed1988

Deletion of 3(p14p23) in secondary erythroleukemia arising in long-term survivors of small cell lung cancer.

Cytogenetic studies were done on the leukemia cells of two patients with small cell lung cancer (SCLC) who developed erythroleukemia (acute nonlymphocytic leukemia, French-American-British M6) after combined modality chemotherapy and radiotherapy for their lung cancer. Surprisingly, both erythroleukemias exhibited the del(3)(p14p23) predominantly found in SCLC. In four other patients who had secondary erythroleukemias associated with other cancers, no deletions of 3p were found. These findings could be accounted for by one of three possible mechanisms: (a) an inherited recessive gene (anti-oncogene or tumor suppressor gene) in this region of 3p was uncovered by the combined modality therapy, (b) an inherited predisposition to damage of both chromosomes at 3p14 leads to SCLC and erythroleukemia after exposure to carcinogens and/or chemotherapy-radiotherapy, or (c) the finding of lineage specificity for the 3p deletion with the presence of the 3p deletion in SCLC and erythroleukemia suggests a common bone marrow precursor.

Aged↗
PubMed1988

Malignant pheochromocytoma: effective treatment with a combination of cyclophosphamide, vincristine, and dacarbazine.

STUDY OBJECTIVE: To determine the efficacy and toxicity of combination chemotherapy in patients with advanced, malignant pheochromocytoma. DESIGN: Nonrandomized, single-arm trial. SETTING: Governmental medical referral center. PATIENTS: Fourteen patients with malignant pheochromocytoma confirmed by histologic tests. All patients had metastatic disease and elevated urinary catecholamine secretion. INTERVENTIONS: After optimization of antihypertensive therapy, patients received cyclophosphamide, 750 mg/m2 body surface area on day 1; vincristine, 1.4 mg/m2 on day 1, and dacarbazine, 600 mg/m2 on days 1 and 2, every 21 days. MEASUREMENTS AND MAIN RESULTS: Combination chemotherapy with cyclophosphamide, vincristine, and dacarbazine produced a complete and partial response rate of 57% (median duration, 21 months; range, 7 to more than 34). Complete and partial biochemical responses were seen in 79% of patients (median duration, more than 22 months; range, 6 to more than 35). All responding patients had objective improvement in performance status and blood pressure. Toxicity included expected hematologic, neurologic, and gastrointestinal effects of chemotherapy without serious sequelae. There were four minor hypotensive episodes and one minor hypertensive episode. CONCLUSIONS: Combination chemotherapy with cyclophosphamide, vincristine, and dacarbazine is effective for advanced malignant pheochromocytoma. Urinary catecholamines are useful to ascertain biochemical response to therapy.

Adolescent↗
PubMed1988

Cornell Scale for Depression in Dementia.

The Cornell Scale for Depression in Dementia is introduced. This is a 19-item clinician-administered instrument that uses information from interviews with both the patient and a nursing staff member, a method suitable for demented patients. The scale has high interrater reliability (kw = 0.67), internal consistency (coefficient alpha: 0.84), and sensitivity. Total Cornell Scale scores correlate (0.83) with depressive subtypes of various intensity classified according to Research Diagnostic Criteria.

Aged↗
PubMed1988

Morphologic and electrophysiologic characterization of isolated pregnant human myometrial cells.

Myometrium was obtained from pregnant volunteers by biopsy of the upper margin of the uterine incision at the time of cesarean section. A multistep enzymatic digestion with collagenase, trypsin, protease, and deoxyribonuclease yielded viable cells capable of contraction. Primary monolayer culture was carried out in the presence of human pregnant serum. Electron microscopic examination of freshly isolated and cultured cells revealed an ultrastructure indicative of smooth muscle cells. Intracellular microelectrode studies were performed on freshly isolated cells. Passive membrane properties were: resting membrane potential, -49.4 mV; specific membrane resistance, 6.06 kohms-cm2; specific membrane capacitance, 1.57 microfarad per square centimeter. Outward-going rectification was observed in response to depolarizing current pulses. Regenerative action potentials were not observed; however, transient voltage responses were elicited after depolarizing, but not hyperpolarizing, current pulses. These studies characterize a human tissue preparation that is applicable to electrophysiologic investigation of the control of uterine function.

Action Potentials↗
PubMed1988

Retrospective analysis of stage I and II indolent lymphomas at the National Cancer Institute.

We have retrospectively reviewed the records of 54 patients with Stages I and II indolent lymphoma treated at the National Cancer Institute between January 1958 and December 1984. Patients were treated by a variety of approaches, with 48/54 patients receiving some form of radiation therapy. The median potential follow-up was 9 years (rang 1.7-23.7 years). Overall survival and disease-free survival at 10 years were 69% and 48%, respectively. There were no relapses among Stage I patients after 6.5 years, with 11 of 27 patients followed beyond that time, suggesting that some patients may be cured. Of the 38 patients who received radiation therapy alone as primary treatment, 17 ultimately relapsed. Seventy-one percent of these relapses were nodal. Our data suggest that patients with early stage indolent lymphoma can be treated with curative intent. The finding that most relapses after radiation therapy occur in untreated lymph nodes suggests that total lymphoid irradiation may prolong disease-free survival and, perhaps, overall survival as well.

Adolescent↗
PubMed1988

Development of a new physicochemical model for brain penetration and its application to the design of centrally acting H2 receptor histamine antagonists.

A rational approach to the design of centrally acting agents is presented, based initially upon a comparison of the physicochemical properties of three typical histamine H2 receptor antagonists which do not readily cross the blood-brain barrier with those of the three brain-penetrating drugs clonidine (6), mepyramine (7) and imipramine (8). A good correlation was found between the logarithms of the equilibrium brain/blood concentration ratios in the rat and the partition parameter, delta log P, defined as log P (1-octanol/water)-log P (cyclohexane/water), which suggests that brain penetration might be improved by reducing overall hydrogen-bonding ability. This model has been employed as a guide in the design of novel brain-penetrating H2 antagonists by the systematic structural modification of representatives of different structural types of H2 antagonists. Although marked increases in brain penetration amongst congeners of cimetidine (1), ranitidine (9), and tiotidine (10) were achieved, no compound was found with an acceptable combination of H2 antagonist activity (-log KB in the guinea pig atrium greater than 7.0) and brain penetration (steady-state brain/blood concentration ratio greater than 1.0). Conversely, structural modification of N-[[(piperidinyl-methyl)phenoxy]propy]acetamide (30) led to several potent, novel compounds which readily cross the blood-brain barrier. One of these, zolantidine (SK&F 95282, 41), whose -log KB is 7.46 and steady-state brain/blood ratio is 1.4, has been identified for use in studying histaminergic H2 receptor mechanisms in brain. Comparison of delta log P values with the logarithms of the brain/blood ratios for 20 structurally diverse compounds for which data became available confirms a highly significant correlation and supports the general validity of this model.

Algorithms↗
PubMed1988

Isomers of 10-hydroxynortriptyline in geriatric depression.

In geriatric, depressed inpatients treated with nortriptyline (NT), total unconjugated plasma concentrations of the Z isomer of the 10-hydroxylated metabolite (10-OH-NT) were determined simultaneously with concentrations of the E isomer by high-performance liquid chromatography. Z-10-OH-NT concentrations averaged 14% of E-10-OH-NT concentrations.

Aged↗
PubMed1988

Zolantidine (SK&F 95282) is a potent selective brain-penetrating histamine H2-receptor antagonist.

1. The novel benzthiazole derivative zolantidine (SK&F 95282) is a potent antagonist of histamine at H2-receptors in guinea-pig atrium and rat uterus. Only apparent pA2 values of 7.46 and 7.26 respectively could be calculated since the slopes of the Schild plots were significantly less than unity. 2. Zolantidine is equally potent as an antagonist at histamine H2-receptors in guinea-pig brain. The compound inhibited histamine stimulated adenylate cyclase (pKi 7.3) and dimaprit stimulated adenosine 3':5'-cyclic monophosphate (cyclic AMP) accumulation (approx pA2 7.63), and competed with [3H]-tiotidine binding (pKi 7.17). 3. Zolantidine is at least 30 fold more potent at H2-receptors than at other peripheral and central receptors investigated. 4. Infusion of zolantidine into rats produces a brain concentration greater than the plateau blood concentration (brain/blood ratio 1.45). 5. Zolantidine is thus characterized as a potent selective brain-penetrating H2-receptor antagonist, and will be a valuable pharmacological tool for investigating possible physiological and pathological roles for histamine in the central nervous system.

Animals↗
PubMed1988

Use of the Cornell scale in nondemented patients.

The Cornell scale is a 19-item clinician-administered scale of depression that uses information from interviews with both patients and their caregivers. The Cornell scale has been validated in demented patients. In this study, the Cornell scale was psychometically tested in nondemented geriatric subjects by administering it to 15 depressed patients, 15 patients with other psychiatric diagnoses, and 15 normal control subjects. The Cornell scale had high interrater reliability (Cohen's kappa = 0.74), internal consistency (Kuder-Richardson's coefficient = 0.98), and sensitivity, and correlated significantly (Spearman's r = 0.81) with Research Diagnostic Criteria psychiatric diagnoses associated with various intensity of depression. To our knowledge, the Cornell scale is the only depression-rating instrument that has been validated in both demented and nondemented geriatric subjects.

Aged↗
PubMed1988

Residual abdominal masses in aggressive non-Hodgkin's lymphoma after combination chemotherapy: significance and management.

When patients with aggressive lymphoma present with intraabdominal disease, a stable residual mass is frequently detected radiographically at the time of the clinical complete remission. To discern the optimal management for this clinical problem, we reviewed 241 patients with aggressive lymphoma treated at the National Cancer Institute (NCI) from 1977 to 1986. Seventy-two/241 patients (30%) had an abdominal mass at diagnosis and 29/72 (40%) were left with a radiographically detectable residual mass at clinical complete remission. The likelihood of a residual mass was much higher for patients with bulky disease (P2 less than .0003) (two-tailed test [P2]). Twenty-nine patients had radiologically stable residual masses after therapy, and of 22 (76%) with pathologic evaluations, 21 had negative specimens (95%) and one was positive (5%). None of the patients with negative pathologic evaluation has relapsed in the abdominal site (median follow-up, 31 months). Seven patients were observed clinically without laparotomy: five are alive, without evidence of disease, at 2 to 9 years; two relapsed with disseminated disease within 2 months of chemotherapy. Initial tumor size and size of the residual mass did not correlate with residual disease, since residual masses identified by radiographic examination did not usually harbor viable lymphoma cells. Aspiration cytology was negative for residual tumor in 15/16 cases. One negative result was not confirmed at laparotomy, presumably due to sampling error. The one positive aspiration was followed by a negative laparotomy, possibly due to subsequent tumor necrosis. Restaging laparotomy has a low yield. In most patients with aggressive lymphoma who have otherwise completely responded to carefully administered full-dose combination chemotherapy, stable residual abdominal masses can be closely followed clinically without surgical exploration.

Antineoplastic Combined Chemotherapy Protocols↗