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Biomedical subjects

X He

Publications and source records attributed to X He.

At least 433 records · Page 24Linked to original sources
PubMed1991

Etiology of childhood diarrhea in Beijing, China.

To determine the role of recently recognized enteropathogens in childhood diarrhea in China, 221 children with diarrhea and 108 controls seen at the Beijing Children's Hospital were studied during April and May 1989. Stools were examined for ova, parasites, and rotavirus, cultured for bacterial pathogens, and probed for enterotoxigenic Escherichia coli (ETEC), enteroinvasive E. coli (EIEC), enterohemorrhagic E. coli (EHEC), and enteropathogenic adherence factor-positive (EAF+) E. coli. Pathogens were identified in 56.5% of children with diarrhea and 43.5% of controls (P = 0.04). Detection of enteropathogens was significantly greater in patients examined within 1 week of symptom onset (65%) than in patients examined later (39%; P = 0.01). ETEC was the most frequently detected pathogen in children with diarrhea, accounting for 20% of the cases. Other agents identified in patients included the following: salmonellae, 12%; rotavirus, 7%; EIEC, 7%; EHEC, 7%; members of the Aeromonas hydrophila group, 6%; EAF+ E. coli, 5%; Ascaris lumbricoides, 3%; shigellae, 3%; campylobacters, 2%; and Vibrio spp., 0.5%. The isolation rates of salmonellae (P = 0.02), EAF+ E. coli (P = 0.04), and mixed pathogens (P = 0.05) were significantly greater for diarrhea patients than for controls. Resistance to multiple antimicrobial agents occurred in 39% of the Salmonella isolates, 22% of the Aeromonas isolates, and 17% of the Shigella isolates. Multiresistant salmonellae (P = 0.05) and shigellae were recovered from diarrheal stools only. Ciprofloxacin, cefotaxime, and imipenem were the only agents tested to which all bacterial isolates were susceptible in vitro. These results suggest that both traditional and newly recognized agents are important causes of childhood diarrhea in Beijing and that therapy may be complicated by indigenous antimicrobial resistance.

Child, Preschool↗
PubMed1991

Tst-1, a member of the POU domain gene family, binds the promoter of the gene encoding the cell surface adhesion molecule P0.

Tst-1, a member of the POU domain gene family, is expressed in specific neurons and in myelinating glia in the mammalian nervous system. Bacterially expressed Tst-1 binds specifically to the promoter of the gene encoding myelin protein P0, a Schwann cell surface adhesion molecule. In cotransfection assays, Tst-1 can specifically repress the P0 promoter. The N-terminal part of Tst-1 protein is highly glycine- and alanine-rich, a structural feature shared by the helix-loop-helix protein TFEB.

Amino Acid Sequence↗
PubMed1991

[Content of astraglin A in zhongfeng naomai tong oral liquid].

Using HPTLC-scanning method, the contents of astraglin A in four kinds of zhongfeng naomai tong oral liquid have been determined to be 0.0018-0.0022%. Simple and easy to use the method is recommended for the quality control of compound preparations containing huangqi.

Chromatography, Thin Layer↗
PubMed1990

Capsaicin inhibits responses of fine afferents from the knee joint of the cat to mechanical and chemical stimuli.

In adult anaesthetized cats we studied the effects of capsaicin on the responses of single slowly conducting afferents of the knee joint to mechanical and chemical stimuli (bradykinin). An intra-arterial bolus injection of capsaicin into the joint reduced or abolished the responses to passive movements of the joint in 8 of 19 afferents and the responses to intra-arterially administered bradykinin in 10 of 11 units. Capsaicin was usually effective at 10(-4) to 10(-3) M. The inhibition was predominantly observed in nociceptive afferents, whereas most low threshold units were not desensitized.

Animals↗
PubMed1990

Circulating glycoconjugates in CSF of meningioma patients.

This study investigated whether tumor-associated gangliosides or glycoproteins may be markers for meningiomas in CSF. The concentrations of a number of gangliosides and sulphatide were determined with specific monoclonal antibodies and cholera toxin B-subunit in a thin-layer chromatography overlay technique. As compared to a reference group of 10 individuals (mean age 50 +/- 14 years), the CSF samples from 7 meningioma patients (mean age 55 +/- 12 years) were found to contain significantly increased concentrations of ganglioside GD3 [II3(NeuAc)2-LacCer], one of the major gangliosides in meningioma tissue specimens. Sulphatide was significantly increased in 6 of 7 patients. Tumor-associated glycoproteins detected by the lectin Ricinus communis 1 in meningioma tissue specimens, but not in normal human brain tissue, were also found in the CSF of the meningioma patients. An early diagnosis of meningiomas might be achieved by the combined assay in CSF of ganglioside GD3 and glycoproteins with Ricinus communis lectin.

Antibodies, Monoclonal↗
PubMed1990

A family of POU-domain and Pit-1 tissue-specific transcription factors in pituitary and neuroendocrine development.

The anterior pituitary gland provides a model for investigating the molecular basis for the appearance of phenotypically distinct cell types, within an organ, a central question in development. The rat prolactin and growth hormone genes are selectively expressed in distinct cell types (lactotrophs and somatotrophs) of the anterior pituitary gland, which reflect differential mechanisms of gene activation or restriction because of interactions of multiple factors binding to these genes. We find that the pituitary-specific 33,000 dalton transcription factor, Pit-1, normally expressed in somatotrophs, lactotrophs, and thyrotrophs, can bind to and activate both growth hormone and prolactin promoters in vitro at levels even tenfold lower than those normally present in pituitary cells. In the case of the prolactin gene, high levels of expression in transgenic animals required two cis-active regions; a distal enhancer (-1.8 to -1.5 kb) and a proximal region (-422 to +33 bp). Each of these regions alone can direct low levels of fusion gene expression to prolactin-producing cell types in transgenic mice, but a synergistic interaction between these regions is necessary for high levels of expression. The initial appearance of the prolactin transgene expression closely follows the appearance of high levels of Pit-1, but later increases in expression coincident with appearance of mature lactotrophs suggest the operation of additional, critical positive factor(s). Unexpectedly, transgenes containing the distal enhancer removed from its normal context are expressed in both the prolactin-producing lactotrophs and the TSH-producing thyrotrophs, thereby suggesting that sequences flanking this enhancer are necessary to restrict expression to the correct cell type within the pituitary. These data indicate that distinct processes of gene activation and restriction are necessary for the fidelity of cell-type specific expression within an organ. Consistent with this model, we find that lactotroph cell lines that cannot express the growth hormone gene contain high levels of functional Pit-1. We suggest a large, highly related POU-domain gene family, potentially exceeding 100 members, has been conserved and expanded in evolution to meet the increasing requirements for more intricate patterns of cell phenotypes. The POU-domain subgroup of the homeodomain gene family, in concert with other homeodomain proteins and with other classes of transcription factors, is likely to contribute to the establishment of the mammalian neuroendocrine system.

Animals↗
PubMed1990

[Localization of human testis determining factors on Y chromosome].

This is a study of in situ chromosomal hybridization and dot blot and southern blot hybridization using a testis determining factor related probe Y156 in sexually malformed patients. According to the phenotype karyotype analysis and hybridization results of these cases, especially 2 cases with dic (Y) and different breakpoints, we consider that the TDF must be located on YP11.32. The clinical value of Y156 probe is discussed.

DNA Probes↗
PubMed1990

[Determination of tangshenoside I in Codonopsis pilosula Nannf. by TLC-UV spectrophotometric method].

A method of thin layer chromatographic separation and ultraviolet spectrophotometric determination of tangshenoside I in Codonopsis pilosula is described. A comparison of the contents in various samples is made. The contents of tangshenoside I in frosted sample have been found to be twice as much as in normal drug. The recovery of tangshenoside I is 99.92% and the coefficient of variation of eight samplings is 1.77%.

Chromatography, Thin Layer↗
PubMed1990

Cyclosporine A prolonged survival time of parathyroid gland allograft in rats.

We divided the experimental animals into three groups. In the first group, only cyclosporine solvent containing no cyclosporine was given to rats. In the second group, cyclosporine A was given intraperitoneally from the 1st to the 5th days after transplantation at a daily dosage of 2 mg/100 g BW. In the third group, besides the first courses of cyclosporine A treatment as in group II, second and third courses were given on the 30th to 34th and 60th to 64th days after transplantation. Our results show that a relatively large dose given in a short course together with intermittent enhancement treatment proves much more effective than a short course without enhancement treatment.

Animals↗
PubMed1990

[Construction of promoter probe vector pFDC4 and gene expression vector pFDC11 with high transformation efficiency in Bacillus stearothermophilus].

A 0.5kb fragment from Sau3A-digested total DNA of Bacillus stearothermophilus CU21 was cloned with the vector pPGV5, a derivative of pPL703. The insertion of this fragment can activate the expression of the promoteless cat-86 gene on the cloning vector in both B. stearothermophilus and Bacillus subtilis hosts. When the 0.54 kb fragment is present in pPGV5 in either orientation, the transformation efficiency of the plasmid is increased about 10(3) to 10(4) fold in CU21 protoplasts. Southern hybridization showed this 0.54 kb fragment was homologous with a 1.6kb fragment, which was shown by Imanaka et al. (1984, J. Gen. Microbiol. 130, 1399-1408) to originate in a cryptic plasmid resident in CU21 and to enhance the transformat on efficiency of another plasmid. With this 0.54kb fragment a new promoter probe vector pFDC4 and a gene expression vector pFDC11 were constructed. Both can transform the CU21 recipient with high efficiency.

Gene Expression↗
PubMed1990

[A study on treatment of retinal detachment with unseen retinal breaks].

64 cases (66 eyes) of retinal detachment in which no breaks can be found were treated with pars plana vitrectomy, scleral buckling or encircling procedures. The selection of operation depended on the shape and size of retinal detachment, the position of peripheral retinal lattice degeneration, phakia or aphakia, traumatic situation and the appearance of proliferative vitreoretinopathy. The results showed that the detached retina was successfully reattached in 53 eyes (80.3%), 4 eyes were improved (6%), only 9 eyes failed (16.7%). The technic of operation and application are discussed. We consider that suitable active surgical treatment for this kind of cases is encouraging.

Adolescent↗