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Biomedical subjects

C Z Chen

Publications and source records attributed to C Z Chen.

At least 37 records · Page 2Linked to original sources
PubMed1993

HIV-related knowledge and attitudes among medical students in China.

A modified version of the 'WHO/KABP Questionnaire for Students' was administered to 302 students at a medical university in China. The instrument included items to assess the students' demographic background, knowledge of AIDS/HIV, attitudes about AIDS, as well as towards people infected with HIV, those groups commonly labelled as 'high risk' and toward sources of information. The average score on the knowledge scale was 80% correct. There was a substantial disparity in knowledge between how HIV is transmitted and how HIV is not transmitted--90% of the former items were answered correctly, while only 72% of the latter were answered correctly. Over 40% of the sample blamed prostitutes for AIDS in China, whereas 22% blamed drug addicts and 6% blamed homosexuals. Two-thirds of the sample indicated that they thought people with AIDS got what they deserve. About one-third of the sample supported quarantine measures as well as keeping infected students out of classrooms. Nearly half of the sample indicated that they did not trust any of the official sources of health information we asked about and 27% said that they thought the government was concealing information about AIDS.

Adolescent↗
PubMed1993

Clinical trials for removal of bilirubin by high-capacity nonionic adsorbent.

To remove bilirubin from patients with hyperbilirubinemia, nonionic macroporous adsorbent NK-110 was tailor-made from styrene and divinyl benzene at Nankai University. Five patients were perfused through shunts filled with 500 ml of the above adsorbent. After 2 h of hemoperfusion, total bilirubin decreased within the range of 22-51%. During the treatment, no noticeable changes in electrolytes, urea nitrogen, serum glutamicpyruvic transaminase (SGPT), TTT, and amino acid concentrations were observed. Platelet depletion was satisfactory. Hemoglobin, white cell count, globulin, and albumin showed no remarkable changes. The nonionic adsorbent shows a high efficacy for bilirubin removal and has a great potential for future clinical applications.

Adsorption↗
PubMed1993

[A study of hygienic standard for titanium in the source of drinking water].

The smell and taste thresholds of titanium in water were tested. The results indicated that the concentration of smell and taste thresholds for Titanium were 4.329mg/L and 3.332mg/L respectively. The threshold below value of autopurification was 0.1mg/L. The toxicity assessment showed that the acute toxicity of titanium by oral route was of low order according to the toxicity classification. There was no obvious cumulative effect, nor was there mutagenesis demonstrable. Chronic toxicity test of titanium in rats showed that the maximum non-effective concentration was 1.08mg/L. It is suggested that the maximum allowable concentration of titanium in drinking water may be 0.1 mg/L.

Animals↗
PubMed1992

[Analysis of 7 elements in the serum and lens of senile cataract patients].

The contents of Fe, Al, Cu, Zn, Ca, Mg and P in the serum and lens of senile cataract patients were determined with inductively coupled plasma (ICP) spectrometry to find that (1) the Fe, Al, Zn and Ca levels in senile cataractous lenses were significantly higher, and the P level lower than those in normal subjects; however, the serum levels of Fe, Al, Zn and Ca were significantly lower, and the level of P higher than those in normal subjects; (2) the serum levels of Cu and Zn varied with the duration of cataract, which could explain the inconsistency among authors with regard to these parameters; (3) the relation between Fe and Al and the development of cataract remained to be elucidated; (4) the Ca/P ratio in senile cataractous lenses was 50 times (1:0.02) that in clear lenses; these 2 elements were regarded to have close relation with cataractogenesis; and (5) Cu and Mg were not related to cataractogenesis, a finding in agreement with most reports.

Aged↗
PubMed1991

Retinopathy, neuropathy and nephropathy in non-insulin-dependent diabetic patients.

In 1978, an epidemiological survey for adult diabetes was conducted in Taipei City. A total of 219 Chinese non-insulin-dependent diabetic patients were discovered and 217 of them were examined for retinopathy, neuropathy and nephropathy. Among the 110 men and 107 women studied, 63.1% were free of complications and the prevalences for retinopathy, nephropathy and neuropathy were 24.0%, 12.9% and 23.5%, respectively. The clinical and biochemical data of the patients were compared. For those with and those without complications, the diabetic duration (8.2 +/- 6.7 vs 4.1 +/- 2.7, years), percentage of insulin treatment (8.8% +/- 0.7%), percentage of hypertension (42.5% vs 26.3%), and the fasting plasma glucose (182.8 +/- 63.6 vs 135.0 +/- 44.6, mg/dl) were significantly different. Diabetic duration and glycemic control consistently correlated with retinopathy, nephropathy and neuropathy. Hypertension and insulin treatment were also associated positively with the complications. The more complications the diabetic patients had, the poorer the glycemic control, the longer the diabetic duration, a higher percentage of insulin treatment and hypertension were found.

Blood Glucose↗
PubMed1991

Modified Wicomb's apparatus for preservation of heart for 24 hours.

To prolong the time of heart preservation, we modified the Wicomb's perfusion apparatus, in which oxygen flow acts as the source of power and provides oxygenation for the perfused myocardium. Ten adult porcine hearts which had been preserved for 24 hours were resuscitated successfully and continued to beat steadily for more than 1.5-3 hours after reperfusion. Myocardial ultrastructure was observed at the end of preservation and 15-120 minutes after reperfusion. The damages of the myocardial ultrastructure at the end of preservation were reversible.

Animals↗
PubMed1990

Advances of adsorbents for hemoperfusion in China.

Activated charcoal with various coating materials were screened and tested as adsorbents in hemoperfusion. Among them silicon rubber polyurethane, crosslinked agrose, polyvinyl acetate, polyhydroxy ethyl methacrylate showed good blood compatible properties. Various types of resins and carbonized resins with different functional groups, and structures were tested for the adsorption of small molecules i.e. creatinine, barbiturates, middle molecules i.e. VitB12, inulin, cytochrome C and large molecules i.e. unconjugated bilirubin. High adsorption capacities were obtained and uncoated carbonized resins showed satisfactory blood compatible properties. NK-107 a macroporous, non-coated resin is now being manufactured and successfully used clinically on patients for acute detoxification of hypnotic drugs. Polysaccharide dialdehyde and polystyrene derivatives etc. were used for the removal of urea, ammonia, potassium and phosphorus. DNA immune adsorbents were prepared for systemic lupus erythematosus therapy.

Adsorption↗
PubMed1989

Reactivity and stability improvement of immobilized glucose oxidase.

Glucose oxidase (GOD) was immobilized on agrose(a) by diazotization using p(beta-sulfate-ethylfonyl)aniline(SESA) as cross-linking agent, (b) by a new improved glutaraldehyde method and (c) by polyacrylamide entrapment. Results showed that GOD immobilized by the improved glutaraldehyde method had an activity of 10% and 100% higher than that by diazotization and entrapment method respectively. Catalase co-immobilized with GOD on agrose greatly enhanced the stability of GOD. Proteins such as hemoglobin(Hb), bovine serum albumin(BSA) and reducing agent i.e. VitC added during immobilization had the same effect but to a lesser extent.

Drug Stability↗
PubMed1987

In vitro in vivo studies on removal of middle molecules by macroporous resins.

Various types of macroporous resin beads were screened for the adsorption of middle molecules in vitro. In order to obtain high adsorption capacity, the pore size of the resin should be large enough to allow diffusion of the middle molecules. The adsorption capacity of X-5 resin for Vitamin B12, inulin and cytochrome C was 35.3 mg/g, 1.2 mg/g and 42.9 mg/g respectively in vitro tests. Hemoperfusion with acute renal failure rat model showed good clearance (0.35 +/- 0.25) with X-5 resin for middle molecules.

Acute Kidney Injury↗
PubMed1986

Biophysical mechanism of radiation damage to mammalian cells by X- and gamma-rays.

Published information on the reproductive death in mammalian cells irradiated by a wide range of X- and gamma-ray energies has been re-analysed to extract intrinsic efficiencies of damage for the secondary electrons in transient equilibrium. On a log-log plot, a linear dependence on the track average l.e.t. and the average specific primary ionization is found, indicating that either serves as a good quality parameter. The soft X-ray data are consistent with this conclusion. Upon comparison with data for fast heavy ion irradiations, the average specific primary ionization is shown to be applicable independently of radiation type whereas track average l.e.t. is not. Furthermore it is revealed that electrons are most damaging near the end of their range but their efficiency is only about 10-20 per cent of that of fast ions at the same quality, possibly due to the influence of multiple scatter on the electron penetration depth. It is deduced that, for the dose rates involved, the damage by electrons is predominantly by intra-track action and not inter-track action. The results are consistent with the suggestion that optimum damage occurs when the mean free path between ionizations is equivalent to the strand separation in the double-stranded DNA.

Animals↗
PubMed1986

Removal of unconjugated bilirubin by macroreticular resin in hemoperfusion.

Macroporous polystyrene and polyvinylpyridine beads with quaternary ammonium and tertiary groups were tailor-made for the adsorption of unconjugated bilirubin. In vitro studies in order to obtain high adsorption capacity, the synthesized macroporous resin should have an average pore size of about 160 A and with surface area as large as possible. As the crosslinking of the resin increased from 4%-40% the amount of bilirubin adsorbed increased from 0.17 mg/g to 2.0 mg/g. Resins containing strong basic groups have higher adsorption capacities than their corresponding weak base groups. Adsorption mechanism studies showed that both chemical and physical adsorption took place. Adsorption of bilirubin in plasma was some what lower than in buffer solution.

Adsorption↗
PubMed1985

X-ray photoelectron spectra study on the derivatives of N-beta-phenethyl amine and N-beta-phenethyl glycine.

The X-ray photoelectron spectra of sixteen derivatives of N-beta-phenethyl amine and N-beta-phenethyl glycine have been studied. The effect of different structures on N1s binding energy and that of their Pauling's atomic charge density on the nitrogen atoms are investigated. The experimental binding energy of N1s is proportional to the calculated Pauling's atomic charge density. It shows that the phosphoryl group is the strongest nitrogen lone pair electron localizing group as compared with the corresponding sulfonyl and acyl derivatives. The XPS results agree with the data that there is no decarbonylation during the synthesis of N-dialkylphosphoryl-tetrahydro-3-benzazepin-1-one. In addition, since the N1s in P-N bond is smaller than that in S-N and C-N bonds, the phosphoryl group can be removed under much milder conditions. These results provide a semi-empirical evidence for the synthesis of the skeleton of the cephalotaxine. It also differentiates the reaction paths for these three different amino protecting groups.

Alkaloids↗