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Biomedical subjects

J Zhao

Publications and source records attributed to J Zhao.

At least 721 records · Page 40Linked to original sources
PubMed1991

Experimental serotonin myopathy as an animal model of muscle degeneration and regeneration in muscular dystrophy.

Degenerating and regenerating muscle fibers, in serotonin-induced myopathy (SM) of rats, were investigated histochemically, immunohistochemically and electron microscopically with polyclonal antibodies against dystrophin, type IV collagen and laminin. The myopathy produced was characterized by grouping of degenerating and regenerating muscle fibers, and degeneration of capillary endothelial cells. Dystrophin disappeared in an early stage of muscle degeneration and reappeared in an early stage of regeneration. On the other hand, type IV collagen and laminin were well preserved throughout the degeneration and regeneration processes, even on the shrunk and wrinkled basement membrane of empty muscle fibers after phagocytosis. Muscle fiber regeneration was completed within each tube of the preserved basement membrane through the fusion of myoblasts derived from satellite cells of single necrotic fibers, myotubes already being visible on the 1st or 2nd day of regeneration on light microscopy. These small regenerating myotubes did not fuse with each other at all. The findings in the present experimental SM study are compatible with those in Duchenne muscular dystrophy, especially at the preclinical stage.

Animals↗
PubMed1991

Nerve growth factor receptor immunoreactivity on the tunica adventitia of intramuscular blood vessels in childhood muscular dystrophies.

Muscle tissues from cases of childhood neuromuscular disorders were examined immunohistochemically and immunoelectrophoretically using a monoclonal antibody against the human nerve growth factor receptor (NGFR). Strong NGFR immunoreactivity on the tunica adventitia of blood vessels and proliferating peripheral nerve endings in biopsied muscle specimens from muscular dystrophy patients was observed, but it was almost completely absent in specimens from non-diagnostic controls and cases of other neuromuscular disorders. This suggests a process in the sympathetic nervous system involving blood vessels in muscular dystrophies. Immunoblot analysis failed to show a band corresponding to 70-75 kd, the reported molecular size of the NGFR, but showed a clear band corresponding to 25 kd in muscular dystrophy patients, which is assumed to be a detached amino-terminal domain of the NGFR.

Adolescent↗
PubMed1991

Calcium and phosphorus fluxes during hemodialysis with low calcium dialysate.

We evaluated the acute effects of varying dialysate calcium concentration on plasma concentrations and dialyzer fluxes of calcium and phosphorus in adult hemodialysis patients. Seven individuals with stable end-stage renal failure were dialyzed 4 hours, three times weekly. The effects of dialysates containing 1.75, 1.25, or 0.75 mmol/L (70.1, 50.1, or 30.1 mg/L) of calcium were compared. Each patient was studied once at each bath calcium concentration. Compared with the predialysis mean value of 2.27 mmol/L (9.1 mg/dL), plasma total calcium concentration increased, remained constant, or decreased with the 1.75-, 1.25-, or 0.75-mmol/L calcium dialysates, respectively. The 0.75-mmol/L calcium dialysate did not cause signs or symptoms of hypocalcemia (and the plasma calcium concentration did not fall below 1.80 mmol/L [7.2 mg/dL]). Plasma phosphorus concentrations decreased equally from a predialysis mean value of 2.16 mmol/L (6.7 mg/dL), regardless of the dialysate calcium concentration. After 4 hours of treatment with the three different dialysates, the cumulative calcium fluxes were significantly different. With 1.75 mmol/L calcium, mean bodily calcium accumulation was 21.9 mmol (879 mg). With 1.25 mmol/L, there was no net calcium flux. With 0.75 mmol/L, mean patient calcium loss was 5.8 mmol (231 mg). Mean phosphorus removal after 4 hours was 32.5 mmol (1,006 mg) and was unaffected by dialysate calcium concentration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Dystrophin in control and mdx retina.

To determine whether or not dystrophin really exists in the outer plexiform layer (OPL) of the retina, we studied control and mdx mice, using four kinds of polyclonal antibodies (DMDP-II, 60 kd, 30 kd and DMDP-IV) against dystrophin. Although control OPL showed a positive immunohistochemical reaction with all four antibodies, mdx OPL showed a positive reaction with DMDP-II and DMDP-IV, a negative reaction with 60 kd and 30 kd antibodies. Immunoblot analysis showed the positive band compatible with the immunohistochemical reaction.

Animals↗
PubMed1991

Bone remodeling in hypervitaminosis D3. Radiologic-microangiographic-pathologic correlations.

To investigate the mechanism of bone changes in hypervitaminosis D3, we compared contact radiographs, microangiograms by injection of Chinese ink, and corresponding histopathologic macrosections of 66 rabbits that received different doses of vitamin D3. In early stages, radiographs showed subperiosteal bone resorption and porotic cortical bone. The corresponding microangiograms showed proliferating vessels in the periosteum and cortical bone with associated dilatation of the Haversian and Volkmann's canals. When metastatic calcification fills these intracortical caverns or the intertrabecular spaces in the metaphysis and physis, the bone shows a diffuse increased density on radiographs. A dense band in the metaphysis reflects a thickening of calcified chondromatrix due to a hypotrophy of the distal metaphyseal capillaries. Six to 12 weeks after vitamin D3 withdrawal, radiographs showed further increased density of the cortical bone, due to newly formed bone and metastatic calcification. Alternating bands of increased and decreased density in the metaphysis and physis reflect the reinvasion of normal vasculature between growth cartilage and calcified chondromatrix, with normalization of endochondral ossification.

Angiography↗
PubMed1991

[Preliminary serological survey on Mycoplasma and Chlamydia infection among gonorrhoea cases].

The antibodies to Mycoplasma hominis (Mh) and Chlamydia trachomatis (Ct) in 123 sera from the patients with gonorrhoea and 108 sera from the healthy persons control were detected with micro-indirect hemagglutination test. The results showed that the antibody to Mh positive rate was 23.58%, GMT 1: 7.60, and to Ct 72.35%, GMT 1: 8.71 in the patients. The differences of the antibody levels between the patients and the controls were significant. It was suggested that the urogenital infections caused by Mh and/or Ct are common in the patients with gonorrhoea in Liuzhou area, Guang Xi Autonomous Region of China. The significance and distributional characteristics of Mh and Ct infections in the urogenital system and the reasons about higher positive rate in the patients with gonorrhea were discussed.

Adult↗
PubMed1991

[Treatment of acute cerebral infarction with PGI2--evaluating the clinical effect and observation of dynamic changes in plasma TXB2 and 6-keto PGF1 alpha levels].

18 patients with acute cerebral infarction were randomly subdivided into two groups: PGI2-treated group (11 cases) and low-molecular-weight Dextran-treated group (7 cases). Dosage of PGI2 was 2-5 ng/kg/min intravenous drip. Infusion was started within 72 hours after the onset of symptoms. The data showed that the plasma 6-keto-PGF1 alpha levels were increased, the plasma TXB2 levels, MAR as well as the scores of neurological deficit were decreased in the PGI2-treated group. The clinical improvement in PGI2-treated group is better than that in the dextran-treated group.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

The antiatherogenic effects of components isolated from pollen typhae.

Based on the results of previous investigations that pollen Typhae, a Traditional Chinese Medicine, Had antiatherogenic effects, several components were isolated successively from the drug and their effects on porcine aortic endothelial cell (EC) and smooth muscle cell (SMC) cultures as well as on platelet aggregation were examined. 12 components isolated from Pollen Typhae have been identified on their chemical structures and biological effects. 4 of them showed different evident antiatherogenic effects. 1) Isorhamnetin-3-O-rhamnosyl-glucoside could stimulate EC to produce tPA and PGI2; 2) Quercetin-3-O-neohesperidose could protect EC from injury by fibrin, as well as raise tPA activity; 3) beta-Sitosterol palmitate could inhibit SMC proliferation and 4) beta-Sitosterol glucoside showed an inhibitory effect on platelet aggregation. These results would provide some information for the search of new drugs in the treatment and prevention of atherosclerosis.

Animals↗
PubMed1990

[Study of dental maturity in children aged 3-16 years in Chengdu].

Dental maturity was studied in a group of 903 healthy children (boys: 465, girls: 438) born in Chengudu from 1972 through 1988. Dental maturity was estimated by the method of Demirjian and Goldstein, which is based on the development of seven left mandibular permanent teeth; teeth formation was studied. The standard and curves of dental maturity for Chengdu children (boys and girls) were constructed. At 3-5 years old, boys had their dental maturity slightly earlier than girls; there was no significant difference between boys and girls (P greater than 0.05). At the age of 7-14, girls were more advanced than boys (P less than 0.05). Developmental curves of seven left mandibular permanent teeth were plotted. The sexual difference was smaller at the crown developmental stage, and it increased during the root development. In all, girls were more advanced by 0.45 year than boys. The maximum average difference was 0.85 year for the canine. The time that each developmental stage has taken was shorter in 50% of girls as compared with that in boys, and it was longer in 28% of girls. There was no difference between boys and girls in the remaining 22% of cases.

Adolescent↗
PubMed1990

[Study chronic radiation-induced lens lesions].

This paper observed the relationships among site, dose pathological morphology, pathogenesis, incidence, and diagnostic criteria in retrospectively evaluating 685 cases of chronic radiation-induced lens damage. We conclude that early diagnosis together with protective measures are indispensible to preventing and treating radiation-induced lens damage.

Cataract↗
PubMed1990

Metastatic calcification within bone. The main cause of osteosclerosis in hypervitaminosis D3. Radiologic-pathologic correlation.

Because the pathogenesis of osteosclerosis in hypervitaminosis D is still not well elucidated, the authors experimentally studied hypervitaminosis D3 in 66 rabbits by injecting different doses of vitamin D3. Contact radiographs of bone specimens showed various signs of osteosclerosis, including dense epiphyses and metaphyses, thickened bony articular surfaces, dense metaphyseal bands, modeling defects at the metaphysis, and dense and thickened cortical bone. The corresponding pathologic sections showed that conspicuous metastatic calcification coated the trabeculae and filled bone marrow cavity and caverns in the original but porotic cortical and periosteal new bone. Rather than being resorbed, the metastatic calcifications were embedded in a thick layer of newly formed bone 6 to 14 weeks after vitamin D3 withdrawal. This study suggests that in hypervitaminosis D3, the osteoblasts and bone marrow undergo degeneration, leading to necrosis and calcification. After vitamin D3 withdrawal, osteoblasts reappear and become overactive, leading to overossification.

Animals↗
PubMed1990

[A study on pathogen antigen and serodiagnosis of Malleus and Melioidosis with McAbs].

A study on pathogen antigen and serodiagnosis of Malleus and Mlioidosis was made with McAbs which are against Ps. mallei or Ps. pseudomallei. The results showed that (1) Ps. mallei and Ps. pseudomallei express different surface antigen types respectively, and there are antigen overlapping in some degree between them; (2) Epitope 2D4 is common to Ps. mallei and Ps. pseudomallei; (3) The antibody which is similar to McAbs 4D4 or 1A9 might be a common serum antibody of Malleus and Melioidosis; and (4) McAb 3A1 is a high specific one which reacts with Ps. pseudomallei only, and with it, it is possible to resolve the immunological problem of distinguishing diagnosis between Malleus and Melioidosis.

Animals↗
PubMed1989

Further study of pollen typhae's effects on the production of tPA and PGI, by cultured endothelial cells.

We had reported that Pollen Typhae, a Chinese traditional herbal medicine could reduce atherosclerotic plaque formation in experimental animals. Fraction IV isolated from Pollen Typhae had the ability to raise tPA and PGI2 productions by cultured porcine aortic endothelial cells (EC). In this paper we reported that F.IV was divided chemically into four subfractions named SubF.1-4 among them SubF.2-2 was further separated from SubF.2, and SubF.4-1 from SubF.4. The six subfractions were tested for their effects on the productions of tPA (125I-fibrin plate method) and PGI2(RIA) by porcine endothelial cells. The results showed that SubF.3 could enhance tPA activity and SubF.2-2 could increase PGI2 level. With Chrono-Log 500 Lumi-Aggregometer, SubF.1,2-2 and 3 were found to be able to inhibit platelet aggregation and release reaction. These data indicated that the mechanisms of Pollen Typhae in its antiatherosclerotic effects were multiple which resulted from various biologic effects exerted by various components of this drug. Chemical analyses were performed and their structures were identified, demonstrating that SubF.2-2 was a flavonoid, while SubF.3 was a group of flavonoids, implying there are some antiatherogenic components in flavonoids.

Adult↗