[Influence of dietary selenium level on immune function of rats with esophageal tumors induced by methylbenzylnitrosamine (NMBzA)]

The influence of dietary selenium of the incidence of esophageal tumor induced by NMBzA and the immune function during carcinogenesis were studied in rats fed with Torula yeast diet and survived for 18 weeks. The incidences of esophageal tumors were statistically not significant among rats on normal, high and low selenium intake (P greater than 0.05). The level of plaque forming cells (PFC), delayed type hypersensitivity (DTH), natural killer cell activity (NK) were significantly higher in the high selenium diet group than those of the low selenium diet group (P less than 0.05). The authors believe that the modulation of dietary selenium can alter the immune function of animals during carcinogenesis but the anticarcinogenic effect of selenium still needs further study.

Mechanism of action of sparfloxacin against and mechanism of resistance in gram-negative and gram-positive bacteria

The inhibition of DNA synthesis by sparfloxacin; accumulation of sparfloxacin into members of the family Enterobacteriaceae, Pseudomonas aeruginosa, and staphylococci; induction of recA in Escherichia coli; and the optimum bactericidal concentration (OBC) were measured, and killing kinetics at the OBC were estimated. The OBC and maximum recA-inducing concentration in E. coli were both 1 microgram of sparfloxacin per ml. Accumulation was rapid; two- to threefold more sparfloxacin than ciprofloxacin accumulated in staphylococci and more sparfloxacin accumulated in staphylococci than in gram-negative bacteria. Laboratory mutants with decreased susceptibilities to quinolones alone or multiply resistant were selected from the Enterobacteriaceae and Staphylococcus aureus by using sparfloxacin.

[A study on the methods for correcting the error in measurement of children blood pressure]

The blood pressures of a group of children was obtained with sphygmomanometer cuffs of varying widths. It was suggested that the cuff width can be effect for accuracy of blood pressure determination, then a correct formula of blood pressure determination using an inadequate cuffs was calculated. The efficacy and feasibility of the formula was tested in another two groups of children. The production of the formula made a possibility for practicing the proposal of American Heart Association in which the width of an adequate cuff was believed to be 40% of the circumference in middle arms. The formula was simple and convenient and should be used in childhood prophylactic medicine, healthy care especially in popularized measurement of children blood pressure and scientific cooperative investigation.

High performance isoelectric focusing using capillary electrophoresis instrumentation

High performance isoelectric focusing in capillaries provides rapid, high resolution separation of proteins based on their isoelectric points. Results can be obtained in a matter of minutes with little or no sample preparation. The technique requires the use of coated capillaries to reduce electroendosmosis so that stable, focused zones can be attained. Once focused, protein zones may be mobilized by the addition of salt to the catholyte or anolyte buffer. On-tube UV monitoring enables direct detection of sample components during mobilization with mass sensitivity equal to that of silver staining. The linear relationship between mobilization time and isoelectric point allows the technique to be used for estimation of protein pI. Demonstrated applications include separation of proteins in biological fluids with possible clinical applications, and characterization of biopharmaceutical proteins and monoclonal antibodies.

[SEM study of invasive characteristics of colorectal cancer]

This paper reports the results of a study on the invasive characteristics of 22 colorectal cancer by scanning electron microscopy (SEM). The results showed that adenocarcinoma cells stretching polymorphic pseudopodia penetrated into peripheral tissue and adhered to or invaded the vessels, but most of the mucoid carcinoma cells migrated separately into the tissue clefts and invaded the vessels. The invasive mode had dominant differentiation in two typical cancer. The author believes that colorectal cancer possesses two invasive factors: ameboid movement and destroying tissues by lysozyme.

[Extraction-spectrophotometric determination of copper in tablets and injections of Chinese medicine]

Cu reacts with neo-cuproin and eosin Y to form a coloured associated complex. In chloroform its apparent E value is 6.83 X 10(4) 1 mol-1 cm-1 at lambda = 544 nm. We used this system to determine the contents of trace copper in some tablets and injections of Chinese medicine. This method is simple, highly sensitive and selective.

On the generalization of the Weinbaum-Jiji bioheat equation to microvessels of unequal size; the relation between the near field and local average tissue temperatures

The extensive series of experiments reported in Lemons et al. [1] show that measureable local tissue temperature fluctuations are observed primarily in the vicinity of the 100-500 micron countercurrent vessels of the microcirculation and thus strongly support the basic hypothesis in the new bioheat equation of Weinbaum and Jiji [2] that these countercurrent microvessels are the principal determinants of local blood-tissue heat transfer. However, the detailed temperature profiles in the vicinity of these vessels indicate that large asymmetries in the local temperature field can result from the significant differences in size between the countercurrent artery and vein. Using the superposition techniques of Baish et al. [9], the paper first presents a solution to the classic problem of an unequal countercurrent heat exchanger with heat loss to the far field. This solution is then used to generalize the Weinbaum-Jiji bioheat equation and the conductivity tensor that appears in this equation to vessels of unequal size. An asymptotic analysis has also been developed to elucidate the relationship between the near field temperature of the artery-vein pair and the local average tissue temperature. This analysis is used to rigorously prove the closure approximation relating the local arterial-venous temperature difference and the mean tissue temperature gradient which had been derived in [2] using a more heuristic approach.

Microskin grafting. I. Animal experiments

This article reports a new grafting technique--microskin grafting. These experiments were carried out in rabbits, and used a small amount of autograft minced into tiny pieces and then spread on a piece of homograft. The combined autograft plus homograft was then transplanted onto the wound of a rabbit. In 12 rabbits, the microskin grafts took well and covered the wound completely in 8 rabbits. The expansion ratios of the micrografts were from 7:1 to 15:1. The healing time of the wound was from 19 to 35 days. The operation failed in 4 rabbits because of the homograft moving. Histological sections revealed that microskin grafts orientated upwards can grow well and those orientated in a lateral or downward direction can grow too. This technique is an effective procedure for repairing extensive wounds with smaller donor sites.