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S L Zhou

Publications and source records attributed to S L Zhou.

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

Comparison of plasma membrane FABP and mitochondrial isoform of aspartate aminotransferase from rat liver.

A relationship between plasma membrane fatty acid binding protein (FABPpm), a putative membrane transporter for long-chain fatty acids, and the mitochondrial isoform of aspartate aminotransferase (m-AspAT) has been reported. Accordingly, we have compared the chemical and immunological properties of rat liver m-AspAT with those of rat liver FABPpm isolated by two procedures: 1) detergent solubilization of the membranes followed by purification via fatty acid affinity chromatography (FABP-1) or 2) salt extraction of the membranes and subsequent purification by high-performance liquid chromatography (HPLC; FABP-2). Comparison of the three protein preparations revealed no differences with respect to NH2-terminal amino acid sequence, amino acid composition, peptides from tryptic digests, AspAT enzymatic activity, isoelectric point, mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), retention on five different HPLC columns, and immunoprecipitation and immunoblotting of SDS-PAGE separated proteins with polyclonal antisera. Examination of the proteins by nondenaturing PAGE showed a consistent second band in FABP-1 and FABP-2 not always present in m-AspAT. However, whenever present, this band was immunoreactive with antibodies to both m-AspAT and FABP-1. Hence, FABP-1 and FABP-2 are indistinguishable from one another. They are also at least closely related, if not identical, to m-AspAT.

Amino Acid Sequence↗
PubMed1993

[Ultrastructural study on spermatogenesis and sustentacular cell of the testes of Schistosoma japonicum].

This paper deals with the ultrastructural study of the spermatogenesis and sustentacular cell of the testes of Schistosoma japonicum by means of TEM. Albeit several papers have reported on the ultrastructural studies of the testes of male reproductive organ of S. mansoni, no systemic observation on the spermatogenesis of schistosome and ultrastructure of the testes of S. japonicum was available. The authors described the characteristics of the spermatogonium, spermatocyte and different appearance of spermatids. The latter was subdivided into 4 types, namely, Sda, Sdb, Sdc and Sdd, which could be identified by the features of nuclear shape and the density of matrix, the distribution of the mitochondria in the cytoplasm, the appearing and the formation of the acrosome-like structure, the presentation and elimination of the residual bodies, etc. The spermatids were embedded and interdigitated among the sustentacular cells, forming a complicated picture in the field of TEM. The acrosome-like structure and the inclusion of residual bodies were revealed in developing spermatids. The origin and the characteristics of these structures were discussed.

Acrosome↗
PubMed1992

Adipocyte differentiation of 3T3-L1 cells involves augmented expression of a 43-kDa plasma membrane fatty acid-binding protein.

A previously described 43-kDa plasma membrane fatty acid-binding protein (FABPPM) was not observed by immunohistochemical methods in proliferating 3T3-L1 fibroblasts. However, it was detectable in plasma membranes by the second day of confluent growth, prior to accumulation of visible lipid droplets, and was strongly expressed in 8-day differentiated adipocytes. These observations were confirmed by extraction of plasma membrane proteins and subsequent immunoblotting. Kinetics of initial [3H]oleate uptake by both fibroblasts and adipocytes consisted of the sum of a saturable and a non-saturable component. During differentiation the saturable component increased progressively. Vmax increased from 3 to 25 to 110 pmol.s-1.mg cell protein-1 between the fibroblast, the 4-day, and 8 day adipocyte stages; Km was 24 nM in fibroblasts and approximately 55 nM in both 4- and 8-day differentiated adipocytes. By contrast, the rate constant for nonsaturable oleate influx decreased progressively from 0.026 to 0.010 ml.s-1.mg protein-1 between the fibroblast and 8 day adipocyte stages. In 8-day adipocytes saturable oleate uptake was inhibited by up to 55% by antibodies against rat liver FABPPM; these antibodies had no effect on uptake of 2-deoxyglucose or the medium chain fatty acid octanoate. They also had no effect on oleate uptake by fibroblasts. These studies support the hypothesis that FABPPM is a component of a saturable transport mechanism for long chain fatty acids.

3T3 Cells↗
PubMed1992

Sex differences in hepatic fatty acid uptake reflect a greater affinity of the transport system in females.

In this study, we examined the hypothesis that the reported sex difference in hepatic free fatty acid (FFA) uptake involves the putative FFA transport system, the plasma membrane fatty acid binding protein (FABPpm). In hepatocytes isolated from both male and female rats, initial [3H]oleate uptake velocity reflected transmembrane influx and not subsequent metabolism and was a saturable function of the unbound oleate concentration. Although Vmax values were similar (61 +/- 2 vs. 65 +/- 5 pmol.min-1.5 x 10(4) cells-1 for females and males, respectively), the apparent Km was significantly smaller in females (40 +/- 4 vs. 90 +/- 11 nM; P less than 0.05), reflecting faster influx velocities in female cells over a range of unbound oleate concentrations. The oleate efflux rate constant was also greater in females (0.280 +/- 0.014 vs. 0.198 +/- 0.020 min-1; P less than 0.05) despite their greater hepatic content of cytosolic FABP. Finally, despite the greater rates of transmembrane FFA flux in female hepatocytes, the surface expression of FABPpm was virtually identical in the two sexes (2.5 +/- 0.5 vs. 2.4 +/- 0.4 microgram/10(6) cells). Collectively, these data indicate that at FFA-to-albumin ratios occurring in vivo the plasma membrane of female hepatocytes transports oleate bidirectionally at a greater rate than that of male hepatocytes. A sex-related difference in the functional affinity of FABPpm for FFA appears the most likely explanation for the greater oleate uptake in females.

Animals↗
PubMed1992

Pharmacokinetics of ribostamycin in paediatric patients.

In the present study, ribostamycin concentrations in serum were measured by microbiological assay in 20 paediatric patients aged 3 months to 11 years after intramuscular ribostamycin 10, 15 and 20 mg/kg. All pharmacokinetic parameters and statistical analyses were calculated by computer. These results showed that the absorption rate constant (ka), elimination rate constant (ke), time to peak serum concentration (tmax), elimination half-life (t1/2), apparent volume of distribution (Vd/F), total body clearance (CL) and area under the serum concentration-time curve (AUC) were significantly different in infants under 6 months from those in children over 3 years (p less than 0.05), except for the peak serum concentration (Cmax) and lag time from administration to the first appearance of drug in the serum (tlag) [p greater than 0.05]. The absorption of ribostamycin in infants was more rapid than that in children, but elimination was slower (p less than 0.05). The Vd/F and CL in infants were also larger than in children (p less than 0.01). There were significant positive correlations between Cmax, AUC and ribostamycin dosage (p less than 0.01). Pharmacokinetic parameters for infants and children were compared with those observed in adults, and it was found that ribostamycin absorption and elimination were more rapid in the paediatric patients. The Cmax in children and infants after intramuscular ribostamycin 10 mg/kg approached that in adults after an intramuscular dose of ribostamycin 500mg. Using a 1-compartment open pharmacokinetic model, the optimum intramuscular ribostamycin administration interval was estimated as 6.01 and 7.56h for children and infants, respectively, while the value was 8.5h in adults. When the drug was administered in multiple doses of 15 mg/kg intramuscularly every 8h, no accumulation occurred in children. It is suggested that ribostamycin be administered in intramuscular doses of 10 to 15 mg/kg twice daily in infants and 3 times daily in children, respectively.

Absorption↗
PubMed1992

[Further observation on the ultrastructure of the sporocyst of Schistosoma japonicum].

A further observation was conducted on the ultrastructure of mother sporocyst (Ms) daughter sporocyst in the brood chamber (b-Ds), migrating daughter sporocyst (mi-Ds) and daughter sporocyst in the liver tissue (1-Ds) of Oncomelania hupensis by scanning and transmission electron microscopy. There are 5 points worthy of mention here, namely: 1. A special structure, microvilli polymerizing cisterna, is found on the tegument of 52-day-old Ms branche in all directions and a tubule-like structure is connected to the matrix of the tegument. The significance of this structure may be dealt with the metabolism and transport of the parasite. 2. The tegumental spines appear on 52-day-old Ms. 3. The function of multilaminated vesicle in the tegument of 1-Ds may be associated with the turning over of the surface coat of the larvae and the compatibility between parasite and molluscan host. 4. Abundant alpha-glycogen granules and mitochondria appear in the cytoplasm of parenchyma cell of brood chamber of Ms and Ds. It is proposed that the parenchymal cells not only served as the filling material, but also serve as the nursing cells for the regulation of asexual reproduction of the sporocysts. 5. The orientation of muscle fibers of the head of the mi-Ds and narrow node region of 1-Ds shows a well development of the inner longitudinal fibers adjacent to the outer circular muscle layer. They run anteroposteriorly or vertically from the dorsal to the ventral. The pattern of muscle fibers may account for the activity of these regions of the parasite. (Figs 1-8).(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1992

[Transmission electron microscopy of tegument and digestive tract of Schistosoma japonicum during long-term cultivation in vitro].

The article reports the result of the observation on the ultrastructure of the tegument and digestive tract of Schistosoma japonicum schistosomula cultured 130 days in vitro in 841 medium, and the 42-day-old adults from infected animal cultured 23 days in 851 medium by transmission electron microscopy. The results showed that the ultrastructure of the tegument including sensory papillae and flame cells was normal. The matrix seemed to have no vacuolization. The surface of the esophagus was highly rugous. Many laminae and lipid droplets filled the lumen of the digestive tract and the tubules-like depressions from basal lamina were occurred. All these structures seemed to have less variation as compared with the prior authors' data from normal worms. It is considered that the above two media which we cesigned were suitable for the growth and development of the schistosomes due to the tegument and digestive tract maintained their metabolic function in the long-term cultivation in vitro. (Figs 1-10).

Animals↗
PubMed1991

Production of hepatitis B virus nucleocapsidlike core particles in Xenopus oocytes: assembly occurs mainly in the cytoplasm and does not require the nucleus.

The location of hepatitis B virus (HBV) nucleocapsid (core particle) assembly in infected cells remains controversial. Some lines of evidence implicate the nucleus; others favor the cytoplasm. Via injection of a synthetic mRNA encoding the HBV nucleocapsid protein (p21.5), we have expressed both unassembled p21.5 and nucleocapsidlike core particles in Xenopus oocytes. Subcellular fractionation reveals that approximately 91% of the unassembled p21.5 and 95% of the core particles are cytoplasmic, with only 9 and 5%, respectively, in the nucleus. We present evidence showing that unassembled p21.5 equilibrates between nucleus and cytoplasm by passive diffusion and that intact core particles do not enter the nucleus. To examine the role of the nucleus in core particle formation, we expressed p21.5 in surgically anucleate oocytes. We show that anucleate oocytes support efficient core particle formation, indicating that (i) the nucleus is not essential for assembly and (ii) the cytoplasm can assemble most core particles found in oocytes. On the basis of our data, we propose that in oocytes, most core particle assembly (up to 95%) occurs in the cytoplasm, but that at least approximately 5% of the cellular core particles are assembled in the nucleus and remain there. We discuss the implications of these findings for the formation of replication-competent core particles in infected cells.

Amino Acid Sequence↗
PubMed1991

150-kD von Willebrand factor binding protein extracted from human vascular subendothelium is type VI collagen.

We have previously shown that von Willebrand factor (vWF), a glycoprotein which plays a critical role in the adhesion of platelets to injured blood vessels, is present within vascular subendothelium. We investigated the identity of the subendothelial binding site(s) for vWF by examining vWF binding to subendothelial constituents and solubilized a 150-kD protein with SDS-urea that bound vWF. This protein had an amino-acid composition similar to that of the type VI collagen alpha-1/alpha-2 chains, was recognized by specific polyclonal antibodies against type VI collagen, and had a similar acidic isoelectric point. Furthermore, we found that purified type VI collagen also bound vWF. Thus, we have identified the extracted 150-kD protein as type VI collagen. This protein may play a significant role in the binding of vWF to vascular subendothelium in vivo.

Amino Acids↗
PubMed1990

Purification of rat liver mitochondrial aspartate aminotransferase and separation of its isoforms utilizing high-performance liquid chromatography.

A rapid method for purification of mitochondrial aspartate aminotransferase from rat liver employing high-performance liquid chromatography is reported. The product is purified 80-fold with a recovery greater than or equal to 50% in a single day. The amino acid composition, N-terminal amino acid sequence, specific activity, and spectral characteristics of the isolated enzyme are similar to those previously reported for this protein. The protein is homogeneous by standard electrophoretic and chromatographic criteria, but can be resolved into at least five isoforms by a carboxymethylated resin column using high-performance liquid chromatography. The principal isoform initially isolated is converted into two additional isoforms with lower specific activity upon storage at 4 degrees C.

Amino Acid Sequence↗
PubMed1990

Plasma membrane fatty acid-binding protein and mitochondrial glutamic-oxaloacetic transaminase of rat liver are related.

The hepatic plasma membrane fatty acid-binding protein (h-FABPPM) and the mitochondrial isoenzyme of glutamic-oxaloacetic transaminase (mGOT) of rat liver have similar amino acid compositions and identical amino acid sequences for residues 3-24. Both proteins migrate with an apparent molecular mass of 43 kDa on SDS/polyacrylamide gel electrophoresis, have a similar pattern of basic charge isomers on isoelectric focusing, are eluted similarly from four different high-performance liquid chromatographic columns, have absorption maxima at 435 nm under acid conditions and 354 nm at pH 8.3, and bind oleate with a Ka approximately 1.2-1.4 x 10(7) M-1. Sinusoidally enriched liver plasma membranes and purified h-FABPPM have GOT enzymatic activity; the relative specific activities (units/mg) of the membranes and purified protein suggest that h-FABPPM constitutes 1-2% of plasma membrane protein in the rat hepatocyte. Monospecific rabbit antiserum against h-FABPPM reacts on Western blotting with mGOT, and vice versa. Antisera against both proteins produce plasma membrane immunofluorescence in rat hepatocytes and selectively inhibit the hepatocellular uptake of [3H]oleate but not that of [35S]sulfobromophthalein or [14C]taurocholate. The inhibition of oleate uptake produced by anti-h-FABPPM can be eliminated by preincubation of the antiserum with mGOT; similarly, the plasma membrane immunofluorescence produced by either antiserum can be eliminated by preincubation with the other antigen. These data suggest that h-FABPPM and mGOT are closely related.

Amino Acid Sequence↗
PubMed1989

Rat monoclonal antibodies to murine IgM determinants: application to antibody purification.

Two monoclonal rat antibodies (RAM11 and RAM12) were raised against mouse IgM antibodies. These 2 antibodies were isotype-specific since they bound murine IgM but not IgG or IgA antibodies; moreover, sera from mouse strains possessing different allotypic determinants inhibited the binding of RAM11 and RAM12. Both antibodies can be readily purified from culture supernatants on protein G-agarose (but not on protein A-agarose). After coupling to Sepharose 4B, RAM11 provided a useful affinity chromatography support for the purification of murine IgM antibodies from biological fluids.

Animals↗
PubMed1989

Characteristics of HBsAg subtypes distribution in Beijing area.

This paper reports that 300 HBsAg positives were distributed in 262 families. 14 of the 262 families had two or more HBsAg positives. In the 14 families, 7 showed the same subtype HBsAg, probably due to HBV infection from family source. Another 7 families showed HBsAg of different subtypes, definitely due to infections from the community.

Adolescent↗
PubMed1989

[A preliminary study on diagnosis of schistosomiasis japonica by indirect immunoperoxidase assay using daughter sporocyst-containing Oncomelania tissue sections].

Schistosoma japonicum daughter sporocysts in Oncomelania tissue sections were, for the first time, used as antigen in the diagnosis of schistosomiasis japonica by indirect immunoperoxidase assay (IIPA-DS). The most strong peroxidase reaction was localized on the tegument of the daughter sporocysts and cercariae, and at some parts of cercarial parenchyma, when IIPA-DS was carried out. Of 112 sera from proven cases of schistosomiasis japonica, 106 (94.6%) were positive, the range of titre dilution was from 1:1 to 1:160, the geometric mean of titres was 1:20. IIPA-DS highly coincided with IHA, COP and ELISA in both sensitivity and strength of reaction. Sera from 101 blood donors and 24 normal rabbits were all negative. No cross reaction with sera from 24 patients with paragonimiasis was observed.

Animals↗