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Biomedical subjects

S H Guo

Publications and source records attributed to S H Guo.

13 recordsLinked to original sources
PubMed2001

A novel enzyme reactor using gluten membrane entrapping cell-associated enzyme.

A membrane enzyme reactor consisting of variable pieces of replaceable cell-immobilized membranes was proposed for the continuous production of bioproducts. To demonstrate the characteristics of the reactor, cell-immobilized membranes were prepared by the entrapment of permeabilized recombinant Escherichia coli cells containing penicillin G acylase within the gluten matrices. A stainless-steel net that was created with a mesh frame was used to support each gluten membrane so that the membranes could be filled into the rectangular-shaped reactor. The reactor equipped with either six or 12 pieces of cell-immobilized gluten membranes containing a biomass concentration of 5%, w/w was effective in catalyzing the production of 6-aminopenicillanic acid from penicillin G. In comparison with intact cells, the cell-immobilized preparation was more stable and the half-life time of the immobilized cell-associate enzyme in gluten membrane was estimated to be 36 days by a long-term operation. As the substrate solution was forced to flow through the reactor equipped with six membranes and in the direction perpendicular to the membranes, the pressure drop was determined to be less than 50 cm H(2)O with a flow-rate up to 50 mL/min. This low pressure due to the porous structure of gluten membrane would lead to a lower operational cost. Increasing either the number of membranes or the area of each cell-immobilized membrane can easily do scaling-up of this membrane reactor.

Anti-Bacterial Agents↗
PubMed2001

Nuclear matrix in developing rat spermatogenic cells.

The nonchromatin structure or nuclear matrix in developing spermatogenic cells of the rat was studied using a biochemical fractionation in concert with resinless section electron microscopy. Observations demonstrated that the nuclear matrix of spermatogenic cells consisted of a three-dimensional network of filaments of variable thicknesses. In spermatogonia and spermatocytes the nuclear matrix consisted of relatively thin filaments, while that of round spermatids consisted of a thicker interconnecting network of filament. In elongating spermatids, the interior of the nuclear matrix consisted of a network of dense filaments bounded by a peripheral lamina. The protein composition of the nuclear matrix in spermatogenic cells was examined by high-resolution two-dimensional gel electrophoresis and correlated with morphological changes characteristic of each stage. The results showed that the proteins of nuclear matrix changed in a cell stage-specific manner. These stage-specific changes corresponded to the major transitions of chromatin structure and function during spermatogenesis. Furthermore, immunocytochemical and immunoblotting analysis of DNA topoisomerase II (topo II) revealed that this enzyme exhibited stage-specific variations and was associated with the nuclear matrix. These results suggest that the nuclear matrix in spermatogenic cells may be involved in mediating DNA modifications and maintaining nuclear organization during spermatogenesis. Mol. Reprod. Dev. 59:314-321, 2001.

Animals↗
PubMed1996

[Comparison between the plaque reduction neutralization test and the hemagglutination inhibition test in determination of human anti-measles antibodies].

In order to evaluate the difference between plaque reduction neutralization test (PNt) and hemagglutination inhibition (HI) test on human anti-measles antibodies, pre- and postimmunization sera collected from 328 infants aged 3-6 months who were immunized with Shanghai 191 measles vaccine, were detected by both methods. The results demonstrated that PNt was more sensitive than HI when they were used to measure the pre-immunization sera. No significant difference was found between these two methods when they were used to measure the post-immunization sera. PNt can be used to test low level maternal anti-measles antibodies in infants, especially for estimating the effect of maternal anti-measles antibodies on the immunogenicity of measles vaccine.

Antibodies, Viral↗
PubMed1995

[Experimental study on anti-duck hepatitis B viral effect of Phyllanthus urinaria of different areas and combined therapy with other drugs].

The duck hepatitis B virus model was treated with phyllanthus urinaria of different area and combined with Sophora flavesceus as well as ciprofloxacin once a day for one month, the results indicated: Guangxi and Yunnan Phyllanthus could lower the serum DHBV DNA significantly (P < 0.05), but Chongqing Phyllanthus couldn't. And the amount of serum DHBV DNA rose a week after stopping of Yunnan Phyllanthus. The antiviral effect of Guangxi Phyllanthus combined with ciprofloxacin seems to be strengthened (P < 0.05).

Animals↗
PubMed1995

[Correlation between kidney deficiency syndrome and bone density].

In order to study the relationship between Kidney Deficiency Syndrome (KDS)and bone density (BD), the BD of 2068 subjects (40-69 years old)was measured with SPA-IIC type monophoton BD scanning device made in China. The subjects including 1144 cases of KDS (320 males and 824 females); 608 cases without KDS (306 males and 302 females); 164 cases of Lung Deficiency (80 males and 84 females); 152 cases of Spleen Deficiency (76 males and 76 females). Through comparison with the same sex and age group, it was found that BD in KDS patients was significantly lower than that in the normal subjects and those without KDS, also lower than that in the Lung and Spleen Deficiency patients. It indicated that KDS had the corresponding BD changes, which confirmed the TCM classical theory "The Kidney governs the bone". Based on the measuring data, the authors took the lower limit of BD normal value minus two folds of SD as the critical value for KDS diagnosis in 40-49 years age group, i. e., male BD < 0.6 g/cm2, female BD < 0.5 g/cm2. The clinical feedback showed that the male and female related coincident rates were 76% and 80% respectively. Therefore, the critical value could be taken as an objective index for KDS diagnosis after excluding other affecting factors.

Adult↗
PubMed1993

[Effect of menopausal time on osteal density].

Osteal density of 189 Kidney Deficiency (KD) women displayed after menopause as determined by the method of gamma-ray absorption. The result showed that the osteal density of the KD women was significantly lower than those women of same ages without KD (P < 0.001) and the osteal density of the women whose menopause occurred before the age of 45 was lower than that after 45 (P < 0.05). This suggested that the prematurity of ovarial function and the decrease of estrogen ahead of time might be the cause. Therefore, the earlier the menopause, the lower the osteal density, as well as the more serious the KD well be.

Age Factors↗
PubMed1989

[Vesicles and the formation of cholesterol monohydrate crystals (CMC) in human bile].

Vesicles have recently been proved to be a nonmicellar mode of cholesterol dissolution and transportation in bile. It was reported that the aggregation of vesicles was a very important step for the formation of CMC. With 9-10 days' observation by transmission electron microscopy, vesicles were found in all the 3 gallbladder, 3 hepatic and 3 T-tube bile from 7 gallstone patients, 2 hours after centrifuged (2 h, 37 degrees C, 100,000g). The four-consecutive steps of CMC's formation were found to be: (1) novoformation of vesicles (25-50 nm), (2) "precrystals" (60-75 nm) appearing on the surface of the aggregates, (3) "precrystals" growing into submicroscopic CMC (600-750 nm long), (4) submicroscopic CMC and microscopic CMC (about 10,000 nm). "Precrystal" was believed as a new finding and it might be the very early step of the nucleation of CMC.

Bile↗