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Biomedical subjects

M M Wu

Publications and source records attributed to M M Wu.

At least 19 recordsLinked to original sources
PubMed1992

Cancer potential in liver, lung, bladder and kidney due to ingested inorganic arsenic in drinking water.

In order to compare risk of various internal organ cancers induced by ingested inorganic arsenic and to assess the differences in risk between males and females, cancer potency indices were calculated using mortality rates among residents in an endemic area of chronic arsenicism on the southwest coast of Taiwan, and the Armitage-Doll multistage model. Based on a total of 898,806 person-years as well as 202 liver cancer, 304 lung cancer, 202 bladder cancer and 64 kidney cancer deaths, a significant dose-response relationship was observed between arsenic level in drinking water and mortality of the cancers. The potency index of developing cancer of the liver, lung, bladder and kidney due to an intake of 10 micrograms kg day of arsenic was estimated as 4.3 x 10(-3), 1.2 x 10(-2), 1.2 x 10(-2), and 4.2 x 10(-3), respectively, for males; as well as 3.6 x 10(-3), 1.3 x 10(-2), 1.7 x 10(-2), and 4.8 x 10(-3), respectively, for females in the study area. The multiplicity of inorganic arsenic-induced carcinogenicity without showing any organotropism deserves further investigation.

Adult↗
PubMed1992

A novel score for predicting the mortality of septic shock patients.

OBJECTIVE: To establish a prognostic scoring system for septic shock patients. DESIGN: The clinical, biological, and hemodynamic data of these patients were retrospectively explored to select variables independently associated with outcome. According to the risk of death, ratings from 0 to 2 points were attributed to each value. SETTING: Medical intensive care service of a 1,000-bed tertiary care university medical center. PATIENTS: Eighty-eight patients in septic shock in whom hemodynamic measurements were performed using pulmonary artery flotation catheters. RESULTS: Fourteen clinical, biological, and hemodynamic variables were selected and rated for each patient. A Simplified Septic Shock Score, available immediately after admission and catheterization, was established by adding the rates of these variables. The mean Simplified Septic Shock Score was 2.5 +/- 1.7 (SD) in 43 survivors and 6.5 +/- 2.3 in 45 nonsurvivors (p less than .0001). Some underlying diseases and characteristics of infections also correlated with the outcome. Further ratings from 0 to 2 points were attributed to these conditions. A Complete Septic Shock Score was calculated by adding these rates to the Simplified Septic Shock Score. The Complete Septic Shock Score had a slightly better prognostic value than the Simplified Septic Shock Score, but it could be determined only after the availability of the microbiological data. The mean Complete Septic Shock Score was 3.1 +/- 1.9 in survivors and 8.4 +/- 2.6 in nonsurvivors (p less than .0001). Both Simplified and Complete Septic Shock Scores showed better association with patient outcome than the Simplified Acute Physiology Score or the Acute Physiology and Chronic Health Evaluation (APACHE II) score. CONCLUSIONS: The Simplified and the Complete Septic Shock Scores are simple scoring systems that appear to predict the outcome of septic shock patients more accurately than general scoring systems, such as the Simplified Acute Physiology Score and APACHE II score. These septic shock scores might be useful in assessing the severity of septic shock patients.

Adult↗
PubMed1991

Voltage dependence of current through the Na,K-exchange pump of Rana oocytes.

We have studied current (IStr) through the Na,K pump in amphibian oocytes under conditions designed to minimize parallel undesired currents. Specifically, IStr was measured as the strophanthidin-sensitive current in the presence of Ba2+, Cd2+ and gluconate (in place of external Cl-). In addition, IStr was studied only after the difference currents from successive applications and washouts of strophanthidin (Str) were reproducible. The dose-response relationship to Str in four oocytes displayed a mean K0.5 of 0.4 microM, with 2-5 microM producing 84-93% pump block. From baseline data with 12 Na(+)-preloaded oocytes, voltage clamped in the range [-170, +50 mV] with and without 2-5 microM Str, the average IStr depended directly on Vm up to a plateau at 0 mV with interpolated zero current at -165 mV. In three oocytes, lowering the external [Na+] markedly decreased the voltage sensitivity of Ip, while producing only a small change in the maximal outward IStr. In contrast, decreasing the external [K+] from 25 to 2.5 mM reduced IStr at 0 mV without substantially affecting its voltage dependence. At K+ concentrations of less than 1 mM, both the absolute value of IStr at 0 mV and the slope conductance were reduced. In eight oocytes, the activation of the averaged IStr by [K+]0 over the voltage interval [-30, +30 mV] was well fit by the Hill equation, with K' = 1.7 +/- 0.4 mM and nH (the minimum number of K+ binding sites) = 1.7 +/- 0.4. The results unequivocally establish that the cardiotonic-sensitive current of Rana oocytes displays only a positive slope conductance for [K+]0 greater than 1 mM. There is therefore no need to postulate more than one voltage-sensitive step in the cycling of the Na, K pump under physiologic conditions. The effects of varying external Na+ and K+ are consistent with results obtained in other tissues and may reflect an ion-well effect.

Animals↗
PubMed1990

Prognostic values of tumor necrosis factor/cachectin, interleukin-1, interferon-alpha, and interferon-gamma in the serum of patients with septic shock. Swiss-Dutch J5 Immunoglobulin Study Group.

Serum concentrations of immunoreactive tumor necrosis factor/cachectin (TNF), interleukin-1 beta (IL-1 beta), interferon-gamma (IFN gamma), and interferon-alpha (IFN alpha) were prospectively measured in 70 patients with septic shock to determine their evolution and prognostic values. In a univariate analysis, levels of TNF (P = .002) and IL-1 beta (P = .05) were associated with the patient's outcome, but not IFN alpha (P = .15) and IFN gamma (P = .26). In contrast, in a stepwise logistic regression analysis, the severity of the underlying disease (P = .01), the age of the patient (P = .02), the documentation of infection (nonbacteremic infections vs. bacteremias, P = .03), the urine output (P = .04), and the arterial pH (P = .05) contributed more significantly to prediction of patient outcome than the serum levels of TNF (P = .07). After 10 days, the median concentration of TNF was undetectable (less than 100 pg/ml) in the survivors, whereas it remained elevated (305 pg/ml, P = .002) in the nonsurvivors. Thus, in patients with septic shock due to various gram-negative bacteria, other parameters than the absolute serum concentration of immunoreactive TNF contributed significantly to the prediction of outcome.

Adolescent↗
PubMed1990

Risk factors for gallstones among Chinese in Taiwan. A community sonographic survey.

A health survey of adults aged 30 years or more was carried out in southwest Taiwan to determine the prevalence of gallstones and to study risk factors associated with gallstones. Blood samples were collected and abdominal sonographic examination and anthropometric measurements were performed on a total of 923 people. The 40 gallstone cases detected resulted in a prevalence of 4.3%. The risk factors explored included age, sex, hepatitis, obesity, hyperlipidemia, and diabetes mellitus (DM). Age and DM were the only significant factors associated with gallstones in our study. With a reference group of 30-39-year-olds as a comparison, multiple logistic regression analysis showed a trend effect with odds ratios of 1.73, 3.74, and 6.32 for age groups of 40-49, 50-59, and 60 or above, respectively. The odds ratio for DM was as high as 2.59. However, sex, body weight index, chronic hepatitis B, and hyperlipidemia were not significantly associated with gallstones.

Adult↗
PubMed1990

Demethylation pathways in caffeine metabolism as indicators of variability in 1,1,1-trichloroethane oxidation in man.

Twenty volunteers were exposed to 191 +/- 7 p.p.m. 1,1,1-trichloroethane or 50 +/- 2 p.p.m. perchloroethylene vapour for 6 hr. They were then evaluated for their rate of caffeine metabolism, mephenytoin hydroxylation and debrisoquine hydroxylation. Seven subjects were identified as 'fast acetylators' of caffeine and one person as a slow metabolizer of debrisoquine. The "slow acetylators" exposed to perchloroethylene excreted an average of 3.83 +/- 0.35 mg trichloroacetic acid within 24 hr (N = 13, +/- S.E.) and the 'fast acetylators' 3.58 +/- 0.48 mg (N = 7, +/- S.E.). The excretion of trichloroethanol by the same persons after 1,1,1-trichloroethane exposure was 14.1 +/- 1.12 mg and 16.7 +/- 1.48 mg, respectively. The excretion of trichloroacetic acid in the latter exposure varied significantly between the seven 'fast' and 13 'slow acetylators' (0.43 +/- 0.08 mg versus 1.03 +/- 0.19 mg; +/- S.E.; P = 0.037). A multiple linear regression analysis confirmed this association when other factors, such as body weight, creatinine clearance, smoking habit and alcohol consumption, were taken into account. One volunteer proved to be a poor hydroxylator of debrisoquine and excreted half the amount of trichloroacetic acid in the perchloroethylene exposure and half the amount of trichloroethanol in the 1,1,1-trichloroethane exposure compared to the others. A reduction in the solvent metabolism could thus be predicted by the debrisoquine test. On the other hand, the caffeine test predicted faster oxidation of trichloroethanol which could be of toxicological and pharmacological importance e.g. in the clinical use of chloral.

Adult↗
PubMed1990

Phrenic nerve transfer for treatment of root avulsion of the brachial plexus.

Phrenic nerve transfer was performed in 164 patients with root avulsion of the brachial plexus. The methods of operation consisted of phrenic nerve transfer to and anastomosis with the musculocutaneous nerve, the phrenic nerve bridging to the musculocutaneous nerve, phrenic nerve anastomosis with or bridging to the median nerve, and phrenic nerve anastomosis with other nerves. Follow-up of 65 patients for more than 2 years showed an effective rate of 84.6%. The result indicated that this operation has no deleterious effects on respiration, and the surgical effects are related to severity of injury, duration, mode of operation and patient's age.

Adolescent↗
PubMed1989

Phrenic nerve transfer for brachial plexus motor neurotization.

We report a series of 164 patients who underwent phrenic neurotization to elements of the brachial plexus with root avulsion injuries. Recipient nerves included musculocutaneous nerve in 125 patients (78 direct neurotizations and 48 with intervening autograft), median nerve in 10 patients, and a variety of other nerves in 28 patients. Sixty-five patients presented a follow-up period of 2 or more years. Of this group, 55 patients (84.6%) achieved a recovery of M-3 or better. We observed no long-term deleterious effects on respiratory function.

Adolescent↗
PubMed1989

Circulatory crisis in free toe-to-hand transfer and its management: I. Clinical experience.

On the basis of experience with 226 patients undergoing free toe transfer for reconstruction of the thumb and fingers, circulatory crises during and after surgery are analyzed and classified according to the time of crisis occurrence. Prompt re-exploration is indicated when the crisis occurs within 24 hr postoperative. Crises occurring 48 hr and more postoperative are usually due to vasospasm, and antispasmodic therapy should be instituted. Surgical intervention in these later cases may prove fruitless.

Finger Injuries↗
PubMed1989

Dose-response relation between arsenic concentration in well water and mortality from cancers and vascular diseases.

Age-adjusted mortality rates were analyzed to examine the dose-response relation between ingested arsenic levels and risk of cancers and vascular diseases among residents in the endemic area of blackfoot disease, a unique peripheral vascular disease associated with long-term exposure to high-arsenic artesian well water and confined to the southwestern coast of Taiwan. The arsenic levels in well water determined in 1964-1966 were available in 42 villages of the study area, while mortality and population data during 1973-1986 were obtained from the local household registration offices and Taiwan Provincial Department of Health. Age-adjusted mortality rates from various cancers and vascular diseases by sex were calculated using the 1976 world population as the standard population. A significant dose-response relation was observed between arsenic levels in well water and cancers of the bladder, kidney, skin, and lung in both males and females, and cancers of the prostate and liver in males. However, there was no association for cancers of the nasopharynx, esophagus, stomach, colon, and uterine cervix, and for leukemia. Arsenic levels in well water were also associated with peripheral vascular diseases and cardiovascular diseases in a dose-response pattern, but not with cerebrovascular accidents. The dual effect of arsenic on carcinogenesis and arteriosclerosis and the interrelation between these two pathogenic mechanisms deserve more intensive study.

Adolescent↗
PubMed1989

Variability in biological monitoring of solvent exposure. I. Development of a population physiological model.

Biological indicators of exposure to solvents are often characterised by a high variability that may be due either to fluctuations in exposure or individual differences in the workers. To describe and understand this variability better a physiological model for differing workers under variable industrial environments has been developed. Standard statistical distributions are used to simulate variability in exposure concentration, physical workload, body build, liver function, and renal clearance. For groups of workers exposed daily, the model calculates air monitoring indicators and biological monitoring results (expired air, blood, and urine). The results obtained are discussed and compared with measured data, both physiological (body build, cardiac output, alveolar ventilation) and toxicokinetic for six solvents: 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, benzene, toluene, styrene, and their main metabolites. Possible applications of this population physiological model are presented.

Adipose Tissue↗
PubMed1989

Variability in biological monitoring of organic solvent exposure. II. Application of a population physiological model.

A physiological population model is used to study the variability associated with the biological monitoring of solvent exposure. The model consists of a combination of a physiological compartmental model and statistical simulation technique. Variable components considered are: exposure concentration, physical workload, body build, liver function, and renal function. The model is applied to six solvents: trichloroethylene, tetrachloroethylene, methylchloroform, benzene, toluene, and styrene. Biological indicators and air monitoring are compared as predictors of exposure, both external and internal (uptake, brain concentration, reactive metabolite formation). It appears that the choice of the best indicator depends on the type of exposure which is to be predicted. The effects of the various factors, environmental, physiological, or metabolic, are quantified and discussed. It is shown that fluctuation in exposure plays a large part in the final variability of biological indicator results. Further improvements and applications of this population model are considered.

Benzene↗
PubMed1988

Retinol-regulated gene expression in human tracheobronchial epithelial cells. Enhanced expression of elongation factor EF-1 alpha.

Conducting airway epithelial cells requires vitamin A or its synthetic chemicals (retinoids) for their survival and for the expression of normal mucociliary functions. By using molecular cloning, we have shown that one of the effects of retinol on cultured human tracheobronchial epithelial (HTBE) cells is the enhancement (from 2- to 4-fold) of the mRNA encoding the elongation factor EF-1 alpha. Sequence analysis has shown that clone HT7, which was identified by differential hybridization procedures, contained a cDNA insert which encoded a protein closely resembling (81%) elongation factor EF-1 alpha from brine shrimp and completely identical to the published sequence of human elongation factor EF-1 alpha (Brands, H.H.G.M., Maassen, J.A., Van Hemert, F.J., Amons, R., and Moller, W. (1986) Eur. J. Biochem. 155, 167-171). Regions of homology of HT7 to EF-Tu from yeast mitochondria, plant chloroplasts, and Escherichia coli are also evident. A single RNA band at 1700 bases was observed for both untreated and retinol-treated HTBE cells, and for mouse liver and parotid glands when Northern transfer from denaturing agarose gel was probed with a 32P-labeled HT7 insert. An enhanced amino acid incorporation and increased protein content per cell for HTBE cells grown in the presence of retinol were observed. Results presented by these studies indicate that retinol may regulate the transcription of a factor required for translation.

Amino Acid Sequence↗
PubMed1988

Postrelational database implementation for newborn screening and tracking.

Development of microcomputer based systems for the management of data in newborn screening programs has posed special difficulties. This paper describes the specific requirements for implementing an effective newborn screening database system using a unique postrelational database system. This system has been developed by Neometrics Inc. for use by laboratories engaged in running high volume newborn screening programs, and is currently operational in a number of state health laboratories.

Database Management Systems↗