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Biomedical subjects

S Yang

Publications and source records attributed to S Yang.

At least 505 records · Page 28Linked to original sources
PubMed1995

Effects of dehydroepiandrosterone in immunosuppressed adult mice infected with Cryptosporidium parvum.

Cryptosporidiosis is a diarrheal disease in humans and other animals caused by the coccidian parasite, Cryptosporidium parvum. This study was undertaken to determine the effectiveness of dehydroepiandrosterone (DHEA) in reducing C. parvum infections in immunosuppressed adult C57BL/6N mice and to identify the immunomodulatory effects of DHEA that result in increased resistance to cryptosporidiosis. Dexamethasone-immunosuppressed mice were readily infected with C. parvum following orogastric intubation with 10(6) oocysts/mouse. DHEA treatment of these mice significantly reduced (P < 0.01) both fecal oocyst shedding and parasite colonization of the ilea. Immunosuppressed mice treated with DHEA had more splenic total T cells, CD4+ T cells, and CD8+ T cells than immunosuppressed mice that were not treated, but the differences were not always significant. Moreover, nonimmunosuppressed mice treated with DHEA had significantly more (P < 0.05) splenic total T cells, CD4+ T cells, and total B cells than nonimmunosuppressed mice that did not receive DHEA. Of particular interest was the significantly larger (P < 0.05) number of CD8+ T cells in immunosuppressed, C. parvum-infected, DHEA-treated mice compared with the same mice that were not treated. Up-regulation of the immune system by exogenous DHEA may be useful in the treatment and palliation of cryptosporidiosis.

Animals↗
PubMed1995

Nonaccommodative factors of refractive accommodative esotropia.

The clinical characteristics of 45 cases of refractive accommodative esotropia were compared with 31 cases of the control group who remained orthotropic in the presence of uncorrected same degree of hypermetropia. In addition to the general ophthalmologic and orthoptic examinations, the accommodative convergence/accommodation (AC/A) ratio, fusional vergences and random dot stereopsis were investigated. The hypermetropic patients without esotropia were found to have a lower AC/A ratio and normal fusional function, while in cases with refractive accommodative esotropia, their AC/A ratios were normal and their fusional functions were decreased, especially significant being the divergent fusional function. In both groups, their stereopsis was defective or absent. It is suggested that esotropia be not simply caused by excessive accommodation due to uncorrected hypermetropia, and the range of divergent fusional function and the level of AC/A ratio be the two factors which determine the causation of esotropia in cases with uncorrected hypermetropia.

Accommodation, Ocular↗
PubMed1995

[Nationwide survey of the distribution of human parasites in China--infection with parasite species in human population].

The infection rate of main species of parasites and their character by first nationwide survey of human parasites was made. The overall infection rate of human intestinal parasite and the infection rate of most species of parasites were higher in females than that in males. The infection rate according to the age group, the highest infection rate was found in the group aged 5-14 years. With regard to the relation between parasitic infections and occupations of the infected persons, the highest infection rates of Ascaris lumbricoides were exhibited in school children, of hookworm and Clonorchis sinensis were in halfpeasants and halfmerchant and vegetable grower; of Trichuris trichiura were in fishers, of Giardia lamblia, Entamoeba histolytica and Taenia were in herdsmen and halfherdsmen and halfpeasants. In this survey it is also shown that each nationality has their main species of parasites. The family clustering of some main parasites were proved by some province/autonomous region/municipality.

Adolescent↗
PubMed1995

Characterization of M-CSF and its receptor in microphthalmic mice.

The macrophage colony-stimulating factor (M-CSF) gene expression in osteopetrotic mice (op/op) is defective due to a point-mutation in the M-CSF gene [1]. However, almost all osteopetrotic patients have been shown to have a normal or elevated circulating level of bioactive M-CSF [2]. To investigate the action of the M-CSF in mi/mi mice (microphthalmic; another osteopetrotic mouse mutant), M-CSF levels and its receptors were studied. We found that serum levels of M-CSF in mi/mi mice were not significantly different from normal control mice. The M-CSF receptor binding affinity of spleen-adherent cells was similar to that of control mice. In spleen cells from mi/mi mice, the receptor binding sites per cell (normalized to total spleen cells, M-CSF receptor positive cells, or M-CSF receptor RNA positive cells) were present in a greater number than in spleen cells from phenotypically normal siblings. Northern blot analysis showed that there is no significant difference in transcripts of the M-CSF receptor (c-fms) in the mi/mi and phenotypically normal mice. Unlike the op/op mutant, M-CSF levels, as well as the affinity and number of M-CSF receptors, do not explain the defect in osteoclastic function in the mi/mi mutation.

Animals↗
PubMed1995

Therapeutic efficacy of paromomycin in immunosuppressed adult mice infected with Cryptosporidium parvum.

The intent of this study was to evaluate the therapeutic efficacy of paromomycin in immunosuppressed adult C57BL/6N mice infected with Cryptosporidium parvum. Seven groups of 10 mice/group were used. Groups 1, 2, and 7 served as normal, toxicity, and placebo controls, respectively. Groups 2-7 were immunosuppressed with dexamethasone phosphate administered ad libitum in drinking water. Groups 3-7 were infected with C. parvum on day 7 postimmunosuppression. Groups 3-6 were treated by administering paromomycin per os for 10 consecutive days, beginning on day 10 postinfection, at dosage levels of 0.25, 0.5, 1, and 2 g/kg/day, respectively. Paromomycin was judged to be nontoxic at the dosage levels used. Groups 1 and 2 remained uninfected while groups 3-7 began shedding oocysts by day 3 postinfection. Paromomycin was therapeutically effective against C. parvum at 1 and 2 g/kg/day as determined by significant reductions in fecal oocyst shedding (P < 0.01), parasite colonization (P < 0.05), and villus atrophy (P < 0.05) in the ilea and terminal ilea of infected mice. We conclude that paromomycin may be useful in the treatment and palliation of cryptosporidiosis.

Animals↗
PubMed1995

Systemic lupus erythematosus presenting as pleural effusion: report of a case.

Systemic lupus erythematosus (SLE) presenting as a pleural effusion in a young male is not common. This paper describes a 20-year-old man who was admitted to hospital with a spiking fever, chills and cough. A chest x-ray showed alveolar infiltration and a moderate right-sided pleural effusion. The patient was treated for parapneumonic effusion. Thoracentesis was performed and cytology of the aspirated fluid was initially interpreted as showing only numerous polymorphonuclear (PMN) leukocytes. However, in spite of antibiotic treatment the symptoms persisted. A careful review of the cytology specimen showed classic lupus erythematosus (LE) cells in addition to PMN cells. Subsequent investigation, including antinuclear antibodies titer, confirmed the diagnosis of LE pleurisy. Therapy with antibiotics was discontinued and treatment with prednisolone 20 mg daily was begun. There was a rapid clinical response including resolution of the fever and pleural effusion.

Adult↗
PubMed1995

The regulation of pac gene expression by CRP and FNR.

The expression of pac gene is under the regulation of many factors. The mechanisms of glucose and oxygen regulation have been studied. It was found that FNR showed no effect on the expression of pac, and CRP activated the expression of pac. The possible binding site of CRP was found to be located upstream to the pac promoter.

Bacterial Proteins↗
PubMed1995

Application of xiang cheng san in treatment of chronic protracted diarrhea in children.

One hundred and sixty-two children suffering from chronic protracted diarrhea were randomly divided into two groups and observed clinically. In the Chinese herbal medicine group (HM group), Xiang Cheng San was externally applied to the umbilicus of patients, while in the western medicine group (WM group), western drugs were routinely given. The results showed that the therapeutic effects were markedly better in the HM than in the WM group. Animal experiments showed that external application of Xiang Cheng San may inhibit hyperperistalsis of the intestine in mice, suppress peristalsis of the isolated smooth muscles in rabbits, and dilate micro-vessels and thus improve micro-circulation of the mesentery in rats.

Administration, Cutaneous↗
PubMed1995

[Laryngeal paralysis and laryngospasm].

The intrinsic laryngeal muscle potential was recorded with electromyography. Vocal cord movements were observed by a video stroboscope. Laryngeal paralysis is divided into mild, moderate, and severe degrees based on the potentials of intrinsic laryngeal muscles and on the status of vocal cord movements. In the past 11 years (from 1983 to 1993) 1211 cases were diagnosed as having mild, moderate, and severe laryngeal paralysis. Among them, there were 11 cases with laryngospasm including 3 mild, 2 moderate, and 6 severe cases. The findings obtained from careful observation on these 11 cases of laryngospasm demonstrated that there were certain relationships between laryngeal paralysis and laryngospasm. During the course of exacerbation or restoration of paralysis, the laryngospasm may occur.

Adult↗
PubMed1995

Cloning and overexpression of thermostable DNA polymerase gene in Escherichia coli.

Thermostable DNA polymerase genes had been amplified from Thermus aquaticus YT-1 using the PCR technique. The amplified 2.5-kb DNA fragment was inserted into pUC18 and confirmed to be a thermostable DNA polymerase gene by restriction mapping and DNA sequencing. The insert fragment was then combined into an expression vector, pBV221. This recombinant plasmid overexpressed a 94-kDa of recombinant protein in E. coli. A 100-mL E. coli. culture could yield 1.5 x 10(5) units of Taq DNA polymerase, which could be applied in the PCR.

Base Sequence↗
PubMed1995

[Diagnosis and surgical treatment of tuberculous lymphadenopathy of hilar and mediastinal lymph nodes].

Fifty-eight patients with hilar and mediastinal tuberculous lymphadenopathy treated with surgical operation were reported. The authors presented their preliminary experience in diagnosis, surgical technique and satisfactory outcome. The concluded that in certain situation, thoractomy is indicated for both acquiring objective, accurate diagnosis and definitive, effective treatment.

Adult↗
PubMed1995

[Overexpression of c-myc and p53 gene in human hepato-cellular carcinoma--a study with immunohistochemistry and in situ hybridization].

Immunohistochemistry (ABC method) and in situ hybridization (DNA-RNA) were used to detect c-myc and p53 gene expression in tissues of human HCC and nearby non-tumorous liver (NT) from 23 patients. The results showed that the positive rates of P62c-myc were 87% (20/23) in HCC and 91% (21/23) in NT. The positive rates of P53 protein were 39% (9/23) in HCC as well as in NT. The positive rates of c-myc and p53 mRNA were 70% (16/23) and 56% (13/23) in HCC and NT respectively. The expression of c-myc and p53 at protein level was significantly correlated with that at mRNA level. These observations suggest a close association of c-myc and p53 gene overexpression with hepatocarcinogenesis. Immunohistochemistry (ABC method) on section of paraffin embedded tissue is a reliable method for detecting c-myc and p53 gene expression in HCC.

Carcinoma, Hepatocellular↗
PubMed1995

[The deterioration of refractive accommodative esotropia].

137 patients with refractive accommodative esotropia who were followed for at least 5 years were investigated. The results showed that in 23 of the 137 patients (16.8%) occurred the deterioration of esotropia that means esotropia can no longer be controlled by wearing a pair of complete corrective spectacles. The deterioration develops most likely in patients with delay of anti-accommodative therapy or with malfunction of binocular vision. The age of onset, refractive status and the visual acuity difference between bilateral eyes are not etiologic factors in the process of deterioration. We consider that early diagnosis of accommodative esotropia, timely prescription of optical correction and maintenance of normal binocular vision play important roles in preventing the deterioration.

Accommodation, Ocular↗
PubMed1995

Geographical distribution of Pseudomonas pseudomallei in China.

1,366 samples of soil and water from southern China coastal provinces were examined for Pseudomonas pseudomallei. Data showed that 58 samples were positive for this bacteria, which is primarily distributed in Hainan Province and the coastal region of mainland. This paper confirmed the environmental presence of P. pseudomallei in China and showed that the distribution of this pathogen has at least reached a latitude of 25.5 degrees north.

Agriculture↗
PubMed1994

Effects of amino acid insertions on the proteolysis of a staphylococcal protein A derivative in Escherichia coli.

In vivo proteolysis of protein ZZT0, derived from the B domain of staphylococcal protein A, was investigated in Escherichia coli before and after insertion of 1-3 multiples of the tetrapeptide Ala-Trp-Trp-Pro close to the C-terminus of ZZT0. Before insertion, ZZT0 was proteolytically stable as judged from the purity of IgG binding proteins up to 1 h after inhibition of protein synthesis with chloramphenicol. Insertion of 1-3 units of Ala-Trp-Trp-Pro into ZZT0 increased progressively the sensitivity to proteolysis and induced DnaK and GroEL binding to the protein. The time for 50% in vivo hydrolysis of the full length protein derivative that was most susceptible to proteolysis, i.e. with three tetrapeptide units, was about 40 min when cultivated in a bioreactor and about 4 min in a shaken flask culture. Molecular masses and N-terminal sequences of the main degradation products indicated that protein ZZT0 is cleaved at identical sites irrespective of the number of inserted tetrapeptide units and that the cleavage sites are located far from the insertion point. Insertion of another hydrophobic amino acid, isoleucine, as the tetrapeptide Ala-Ile-Ile-Pro, only induced a slight proteolysis of the ZZT0 molecule under similar conditions. This indicates that the insertion of tryptophan residues, rather than of a general hydrophobic segment, plays an essential role in the induced proteolysis of the ZZT0 protein.

Amino Acid Sequence↗
PubMed1994

De novo 17q paracentric inversion mosaicism in a patient with Beemer-Langer type short rib-polydactyly syndrome with special consideration to the classification of short rib polydactyly syndromes.

A de novo 17q paracentric inversion mosaicism is detected in a fetus with type IV short rib (polydactyly) syndrome (Beemer-Langer). The cytogenetic finding in our case suggests a possible location of the gene or cluster of linked genes responsible for SR (P) S type IV to 17q21 or 17q23. Since this chromosome abnormality has not been described in short rib polydactyly syndromes and the existence of type IV SR (P) S has been controversial, the literature of this entity is reviewed with special consideration to the classification of short rib polydactyly syndromes.

Chromosome Aberrations↗