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Biomedical subjects

P Chang

Publications and source records attributed to P Chang.

At least 289 records · Page 16Linked to original sources
PubMed1982

Hemodynamic changes during prostatectomy in cardiac patients.

Hemodynamic responses to transurethral prostatectomy (TURP) were studied in 9 patients with severe cardiac disease. This group of patients tolerated spinal anesthesia and TURP in an unpredictable manner. One adverse effect was the high pulmonary capillary wedge pressures (WP of 21 mm Hg or higher) in 4 of the 9 patients during operation. All nine cases were considered. Attention was directed toward significant cases. The high WP was not always indicated by high CVP either before or during operation, and it did not necessarily relate to the amount of fluid utilized or amount of prostate resected. Another adverse effect was the marked changes in systemic resistance in 6 patients. Because of the unpredictable hemodynamic responses, thermodilution flow-directed pulmonary artery catheter was valuable in several cases. It made it possible to select specific therapeutic agents and direct tham at isolated hemodynamic dysfunctions.

Aged↗
PubMed1982

Clinical trial of an algorithm for outcome prediction in acute circulatory failure.

The authors evaluated prospectively an index for outcome prediction previously developed retrospectively from the cardiorespiratory data of a series of 113 critically ill postoperative general surgical patients. A predictive score generated by nonparametric multivariate analysis of the observed value for each cardiorespiratory variable and the frequency distributions of survivors' and nonsurvivors' values of that variable at each stage of postoperative shock. An overall global predictive index was then generated from the sum of the weighted predictive scores in each variable. This predictive index was tested prospectively in a new series of 156 operations and was found to be 94% accurate for the values of the last available data set, suggesting that the method satisfactorily predicts outcome. This index may be used as an objective measure of the severity of illness; i.e., it may be used to track the clinical course of postoperative general surgical patients during periods of critical illness. It was concluded that the predictive index aids in evaluation of monitored cardiorespiratory variables, improves interpretation of physiologic alternation, and facilitates clinical decision-making of critically ill patients at the bedside.

Adult↗
PubMed1982

Clinical trial of survivors' cardiorespiratory patterns as therapeutic goals in critically ill postoperative patients.

The hypothesis was tested that the median values of survivors of life-threatening postoperative conditions, rather than the norms of unstressed healthy volunteers, are the appropriate therapeutic goals for critically ill postoperative patients. The authors studied prospectively a series of 100 consecutive critically ill postoperative patients; normal values were used as the therapeutic goals of the control patients, while the median values of survivors were used as the goals of therapy for the protocol group. The age, sex, primary illness, surgical operation, lowest mean arterial pressure (MAP), time in hypotension incidence of severe hypotension (MAP greater than 50 mm Hg), and presence of associated severe medical illnesses (defined by predetermined criteria) were comparable in the control and protocol groups; i.e., clinical conditions of the protocol group were at least as severe as those of the control group. The mortality was significantly less in the protocol group (13%) than in the control group (48%); the number of life-threatening complications were also greater in the control group. These data suggest that the cardiorespiratory pattern of survivors are the appropriate goals of therapy for critically ill patients.

Adult↗
PubMed1981

Adenocarcinoma of the appendix.

Twenty-two cases of appendiceal adenocarcinoma are reviewed. Correct diagnosis was not made preoperatively in any case, and in only 38 per cent of the cases was it made intraoperatively. Thirty-two per cent of the patients had second primary neoplasm, and in more than half of these cases, the neoplasms were most likely concurrent with the appendiceal tumors. The overall five-year survival rate of the 22 patients was 18.7 per cent, with a 43.4 per cent survival rate in the curative resection group. The grade of tumor differentiation was the only significant factor in determining curative resectability and prognosis.

Adenocarcinoma↗
PubMed1981

Polymer implant materials with improved X-ray opacity and biocompatibility.

Poly(methyl methacrylate) samples containing 28 wt% inorganic fillers such as zirconium oxide, barium sulphate, zinc oxide, magnesium oxide and tricalcium phosphate were prepared and studied for their suitability as implant materials by physical property tests, X-ray opacity measurement, cell culture, and animal implantations. Addition of inorganic fillers to poly(methyl methacrylate) increased the compressive strength but decreased the transverse strength. Zirconium oxide was found to be most suitable as an X-ray opaque filler, and tricalcium phosphate showed superior biocompatibility when added to poly(methyl methacrylate) in cell culture experiments. The zirconium oxide and tricalcium phosphate composites evoked no greater unfavourable tissue reaction in rats than pure poly(methyl methacrylate). From the physical and biological standpoints zirconium oxide is the radiopaque filler of choice to be incorporated in poly(methyl methacrylate) implant material and addition of tricalcium phosphate could improve it's biocompatibility.

Animals↗
PubMed1981

Personality characteristics of nonretarded phenylketonurics and their family members.

The effect of phenylketonuria cannot be restricted merely to the intellectual function of the central nervous system. Because of increasing evidence that phenylketonurics present different personality problems, this study was undertaken to learn the personality characteristics of 19 nonretarded phenylketonurics, their 27 unaffected siblings, and 36 parents as reflected in their MMPI profiles. Results indicated increased incidence of psychopathology in male PKUs, and, to a lesser extent, unaffected male siblings. No consistent trend toward psychopathology was found in female PKUs, female siblings or in parents. Personality profiles indicating significant psychopathology were more frequently encountered among adult male PKUs than among adolescent male PKUs. This study suggests that heterozygous parents of phenylketonurics do not manifest psychopathological personality characteristics, and that male offspring of heterozygous mothers have a higher risk of developing psychopathology than have female children.

Adolescent↗
PubMed1980

Cis-Dichlorodiammine platinum and adriamycin therapy for advanced gynecological and genitourinary neoplasms.

Cis-Dichlorodiammine platinum (DDP) 75 mg/m2 on days 1 and 8 and Adriamycin (ADR) 60 mg/m2 on day 1 were used in 31 patients with advanced gynecological and genitourinary neoplasms. The DDP was given by 6 hours intravenous infusion with 2 liters of 5% Dextrose and 0.5 normal saline using Mannitol and/or furosemide diuresis. Courses were repeated every 21 to 28 days. Responses were seen in 7 of 8 patients with germinal cell neoplasms (5 complete, 2 partial) with a median duration of eight months. A partial response was obtained in 3 of 7 patients with bladder carcinoma with a median duration of three months. There were four partial responses obtained in 9 patients with ovarian carcinoma with a median duration of five months. Toxicities included nausea and vomiting in all 31 patients, nephrotoxicity (serum creatinine > 2 g/100 ml) in patients, tinnitus and/or high frequency hearing loss in 10 patients, and neurotoxicity (peripheral neuropathy, normal pressure hydrocephalus, papilledema) in 8 patients. Severe leukopenia (WBC < 2000/cu mm) and thrombocytopenia (< 100,000/cu mm) occurred in 25% and 45% of evaluable courses, respectively and necessitated dosage reduction in all and delay of therapy in some patients. Peak plasma Pt levels were 2.61 +/- .18 microgram/cc on day 1 and 3.52 +/- .39 microgram/cc on day 8 with a longer terminal half-life on day 8 (252 hours) compared to day 1 (156 hours). Peak plasma ADR levels ranged from .53 to 1.67 N moles/cc with an average terminal half-life of 22.8 hours. This agrees with values of ADR when given alone. This dose and schedule of DDP-ADR is active against advanced gynecological and genitourinary neoplasms, but the amount of toxicity seen indicates that modifications will have to be made.

Adolescent↗
PubMed1980

Increased incidence of brain metastases in sarcoma patients.

Eleven cases of brain metastases that developed in 114 sarcoma patients are presented. Two of 11 patients presented with brain metastasis at the time of diagnosis and the other nine developed them later. The high incidence of brain metastases in patients with rhabdomyosarcoma (26%) and malignant fibrous histiocytoma (27%), two types of tumor which supposedly metastasize rarely to the brain, is remarkable. The increased incidence of brain metastases may be related to longer survival of sarcoma patients and to the inability of AMN and other drugs used in the treatment of sarcomas to cross the blood-brain barrier. Preventive treatment of brain metastases with drugs active in the CNS or with radiotherapy following the diagnosis of pulmonary metastases, could be useful, especially in patients with rhabdomyosarcoma and malignant fibrous histiocytoma.

Antineoplastic Agents↗
PubMed1980

Hypertrophic pulmonary osteoarthropathy and metastases from a malignant fibrous histiocytoma.

Malignant fibrous histiocytoma is a recently accepted member of the mesenchymal group of tumors. Hypertrophic pulmonary osteoarthropathy is rarely seen with metastatic lung disease but when it occurs it is most frequently described with sarcomatous tumor metastases. In the case reported here, this phenomenon developed with pulmonary metastases from a malignant fibrous histiocytoma, indicating that this tumor resembles other sarcomas in giving rise to this unusual clinical syndrome.

Adult↗
PubMed1979

Cardiorespiratory monitoring in postoperative patients: I. Prediction of outcome and severity of illness.

An index for prediction of outcome for use as a measure of the severity of illness was developed by a nonparametric multivariate analysis of cardiorespiratory data from 113 critically ill postoperative general surgical patients. This severity (predictive) index was based on a computerized algorithm that compares a given observed value with the frequency distributions of survivors and nonsurvivors. The difference in the mean values of this index for survivors and nonsurvivors was statistically significant (p less than 0.001) during each stage of shock. Sensitivity of the index in prediction of survival ranged from 70-93% depending upon stage, the specificity of the index ranged from 76-92%, and the predictive accuracy ranged from 87-96%. The severity index is used as a process measure to track the course of critically ill patients and to evaluate the efficacy of alternative therapies.

Cardiovascular System↗
PubMed1979

Cardiorespiratory monitoring in postoperative patients: II. Quantitative therapeutic indices as guides to therapy.

Immediate (proximate) and late (optimal) therapeutic goals for critically ill postoperative general surgical patients were based on the frequency distributions of cardiorespiratory data of the survivors immediately after resuscitation and in the late stage of shock, respectively. An algorithm was developed which expresses in quantitative terms the distance from observed values for each variable to both of these therapeutic goals. Further, composite indices were also made of related cardiorespiratory variables that reflect the important aspects of acute circulatory failure and its therapy; i.e., volume, flow, tissue perfusion, oxygen transport, and bodily response to stress. The therapeutic indices of nonsurvivors were found to have greater mean deficits that survivors (p less than 0.05) during all but the middle stage of shock. The therapeutic indices greatly aid in the organization and display of monitored cardiorespiratory variables by expressing the circulatory defects in easily understood indices that can be related to therapeutic interventions. Moreover, the interactions of the various aspects of cardiorespiratory function before and after therapy may be easily observed.

Cardiovascular System↗