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Biomedical subjects

S C Zhang

Publications and source records attributed to S C Zhang.

At least 73 records · Page 4Linked to original sources

Observations on renal function in workers exposed to lead.

Renal function was studied in 40 workers chronically exposed to lead at a smelter. The geometric means of lead were 40 (range 24.0 - 63.0) micrograms/dl in blood and 47 (range 19 - 115) micrograms/g creatinine or 71 (range 20 - 250) micrograms/l in urine, respectively. There were no significant differences between the lead-exposed group and a control group in the concentrations of beta 2-microglobulin in serum, urinary total protein and IgG, whereas the level of beta 2-microglobulin in urine was significantly higher in the lead-exposed group (p less than 0.01). No individual lead worker showed abnormally increased level of urinary beta 2-microglobulin. The significance of increased excretion of beta 2-microglobulin on the basis of the group remains to be elucidated.

Environmental Exposure↗

An electroneurographic assessment of subclinical lead neurotoxicity.

While heavy exposure to inorganic lead is capable of inducing symptomatic neuropathy in man, the subclinical neuropathy due to low levels of occupational lead exposure remains to be proved. The reported results of electroneurographic studies on lead workers, however, have been controversial. In this study, 40 lead smeltery workers and 50 non-exposed referents were investigated. The air concentrations of lead at worksites were 0.25 to 42.5 mg/m3. The geometric means of PbB, PbU and delta-ALAU in lead exposed group were 40.03 micrograms/dl, 71 micrograms/l and 4.68 mg/l respectively, which were significantly higher (P less than 0.001) than those (7.01 micrograms/dl, 6.0 micrograms/l and 1.81 mg/l respectively) in the reference group. There were no clinical symptoms or signs of nerve damage in either group. Alcoholism and diabetes were excluded in both groups. Nerve conduction velocity was measured by a DISA 1500 electromyograph in both groups. Eleven electroneurographic parameters, including motor nerve conduction velocity (MCV) and distal latency (DML) of median, ulnar and peroneal nerves as well as sensory nerve conduction velocity (SCV) and distal latency (DSL) of median, ulnar and sural nerves, showed statistically significant differences between the two groups. However, the results of electroneurographic measurements of each individual in the lead-exposed group were all within the normal range. There was no correlation between the blood-lead levels and the neurophysiological measurements except for the median MCV. No correlation was seen between the median MCV and the exposure duration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Acute renal failure and multiple organ system failure.

We treated 23 patients with acute renal failure who had multiple organ system failure. The patients ranged in age from 16 to 66 years (mean, 36 years). All patients underwent hemodialysis. Mortality increased with the number of organ systems involved, from 22% for patients with two systems involved to 100% for patients with four systems involved. The overall mortality was 47.8%. The association of ventilatory failure and sepsis resulted in the most deaths. Early resuscitation, eradication of the primary lesion, and hemodialysis are the most important points in the treatment and prevention of multiple organ system failure in patients with acute renal failure. Thus, the problems of single and multiple organ system failure in China are similar to those in other countries.

Acute Kidney Injury↗

Receptor-mediated binding of C1q on pulmonary endothelial cells.

Normal undamaged pulmonary endothelial cells appear to be immunologically privileged in that they do not express receptors for the Fc portion of IgG nor for C3b. However, these receptors become unmasked on endothelial cells injured by viral infection or exposure to white cell lysates. We now present evidence to indicate that C1q binds to specific receptors on the surface of normal healthy endothelial cells. The binding is dose-dependent, reversible and saturable. Furthermore our data show that binding of C1q to endothelial cells is via the collagenous portion of the molecule not via the globular head regions. Thus binding of C1q to endothelium would have the effect of exposing Fc receptors that could then bind to IgG of circulating immune complexes. That Fc receptors are in fact exposed is shown by rosette formation with antibody sensitized erythrocytes. With 2C1r-2C1s-associated C1q, no binding occurred using C1 fixation and transfer assays. Our results indicate that C1q binding to endothelium provides a means for localizing immune complexes on pulmonary vessels and may be important in the initiation and progression of the inflammatory response.

Animals↗