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Biomedical subjects

J Qi

Publications and source records attributed to J Qi.

122 records · Page 7Linked to original sources
PubMed1993

[An investigation of the effect of rostral ventrolateral medulla lesion on pressor response induced by electrical stimulation of hypothalamic paraventricular nucleus in the cat].

The experiments were performed on 20 adult cats anesthetized with chloralose and urethane, paralyzed and artificially ventilated. The rostral ventrolateral medulla (RVL) was explored by electrical stimulation. We found that an area, 3-5 mm rostral to the obex, 3-4 mm lateral to the midline, and 0-1 mm from the ventral surface of the medulla, was the most effective region for producing a pressor response. After bilateral microinjection of kainic acid into or electrolytic lesion of the above-mentioned active RVL area, a large decrease in arterial blood pressure was elicited, and the pressor response induced by electrical stimulation of the hypothalamic paraventricular nucleus (PA) was nearly eliminated. The results suggest that the RVL mediates the PA pressor response.

Animals↗
PubMed1992

Cytosol-free calcium concentration in single bladder smooth muscle cells from normal and diabetic rats.

The effect of diabetes mellitus on intracellular calcium concentration was measured in single rat bladder smooth muscle cells using the fluorescent calcium indicator dye fura-2 AM. Techniques were developed for isolation and short-term culture of rat bladder smooth muscle cells. Cytosol-free calcium concentrations were measured at rest and during carbachol stimulation. Peak intracellular calcium concentration, rate of increase in intracellular calcium concentration and the integral of accumulation of intracellular calcium were determined. The techniques used to isolate and culture bladder smooth muscle cells produced live, physiologically responsive cells. Resting intracellular free calcium levels and were similar in control and diabetic cells. Both control and diabetic cells responded to carbachol stimulation. No significant differences between these cells were noted in peak calcium concentrations, rate of response or integral of response, but standard errors were large. Two patterns of intracellular response to carbachol stimulation were identified, and may explain the large variability in intracellular calcium response to carbachol stimulation.

Animals↗
PubMed1989

Dynamic CT scan of intracranial tumors.

Of ninety-eight patients with intracranial tumors examined by dynamic CT scanning, 66 were confirmed operatively and pathologically. Our study showed that: 1) Dynamic CT can be performed safely and easily in outpatients; 2) Acoustic neurinoma, meningioma, pituitary chromophobe adenoma, astrocytoma and metastatic tumor have varying levels of time-density curves; 3) The tissue-blood ratio (TBR) at peak time (TBRp) is a useful indicator of the vascularity of tumoral tissues, and analysis of the time-density curve combining with TBRp is helpful to the differential diagnosis of tumors; 4) Differential diagnosis between tumors and vascular abnormalities such as aneurysm and arteriovenous malformation could be made easily with dynamic CT.

Adenoma, Chromophobe↗
PubMed1989

[Comparative study on protein components of ouabain resistant mutant and wild cells of Chinese hamster V79 cell line by two-dimensional gel electrophoresis].

In the sense of gene expression, the primary and direct change in mutant cells should be involved in the protein component. Two-dimensional polyacrylamide gel electrophoresis has been used to compare the protein components of ouabain resistant mutant cells (ouaR) and sensitive wild type cells (ouaS) of chinese hamster lung cell line V79. The procedure is based on O'Farrell's method and we have made some modifications. In order to make the study reliable, we took twenty polypeptide spots as a reference marker. These marker spots could always be reproduced in a series of parallel experiments with both mutant and wild cells. In addition, these markers covered different small areas, representing different isoelectric point (pI) and molecular weight (MW) on the electrophoretogram. With reference to these marker spots, some polypeptide spots showed variations in their position, size and density. It is notable that the changes appeared in the small area 4 (pI/MW:5.0/28-30kd) and the small area (pI/MW:6.3/39kd) is highly reproducible and significant, so that these changes might be specific to ouabain resistant mutant of V79 cells. Since the level of genetic polymorphism of mammalian cells on two-dimensional gel electrophoresis is quite low, these specific changes might reflect the differences in gene structure and expression. This primary study should enhance the usefulness of two-dimensional gel electrophoresis for mutagenesis research with cultured mammalian somatic cells.

Animals↗
PubMed1989

[Correlation between videodensity and iodine concentration in DSA--a prospective research].

This article is a prospective research on parametric imaging of DSA. With the help of phantoms, the authors finished the transformation of videodensity into iodine concentration. The value of iodine concentration will be used as the basis of parametric imaging instead of videodensity which is a non-dimensional value. In part "I" of this article, the authors obtained a group of attenuation curves of 24 iodine samples, which are energy dependent, and verified the possibility of transformation of videodensity into iodine concentration under the non-standard conditions. In part "II", the authors designed a group of phantoms and an exposure program in order to accomplish the density-concentration transformation under clinical conditions. The feasibility of the method was confirmed.

Absorptiometry, Photon↗
PubMed1989

[DSA parametric imaging--a research on organs blood flow perfusion].

This was an animal experimental study about blood flow perfusion of the kidney, brain and lung with DSA parametric imaging. The authors set up a gradient stenotic vessel model for research of blood flow perfusion of the kidney and brain, and a model of balloon embolization for research of blood flow perfusion of the lung. The experiment indicated that these models can reflect exactly the quantitative changes of blood flow perfusion of organs. The parameter-"peak height" is a useful indicator reflecting the quantitative changes of regional blood flow, whereas both time parameters-Tmax and 1/2 Tmax are not sensitive ones. The authors suggested that the information obtained from this experiment could be used as the basis for DSA parametric imaging in human.

Angiography, Digital Subtraction↗
PubMedDate not supplied

L-deprenyl induces aromatic L-amino acid decarboxylase (AADC) mRNA in the rat substantia nigra and ventral tegmentum. An in situ hybridization study.

L-Deprenyl is a complex drug, and number of mechanisms have been proposed to explain its effects. These include blockade of dopamine metabolism, amplification of dopamine responses, induction of superoxide dismutase or delaying apoptosis. Using in situ hybridization techniques, we have shown that L-deprenyl (5-10 mg/kg intraperitoneally, killed after 24 h) increases aromatic L-amino acid decarboxylase (AADC) mRNA levels in rat substantia nigraventral tegmental area. In human brain tissue, AADC is present at low levels, suggesting a possible rate-limiting role in monoamine synthesis. This is particularly important in parkinsonian patients, since the therapeutic efficacy of L-DOPA is attributed to its enzymatic decarboxylation to dopamine. The present findings support that one of the effects of L-deprenyl may be to facilitate the decarboxylation of L-DOPA by increasing the availability of AADC.

Animals↗
PubMedDate not supplied

Potential virulence determinants in terminal regions of variola smallpox virus genome.

Smallpox eradication culminated the most successful antimicrobial campaign in medical history. To characterize further the linear double-stranded DNA genome of the aetiological agent of smallpox, we have determined the entire nucleotide sequence of the highly virulent variola major virus, strain Bangladesh-1975 (VAR-BSH; 186,102 base pairs, 33.7% G + C; Genbank accession number, L22579). Here we highlight features of the molecule and focus on a few of the 187 putative proteins that probably contribute to pathogenicity and virus host-range properties. One hundred and fifty proteins were markedly similar to those of vaccinia virus (smallpox vaccine), for which a complete sequence has been reported for strain Copenhagen (VAC-CPN; 191,636 base pairs, 33.3% G + C). The remaining 37 proteins reflected variola-specific sequences or open reading frame divergences for variant proteins, which are often truncated or elongated compared with their vaccinia counterparts.

Animals↗
PubMedDate not supplied

Fine needle aspiration cytology diagnosis of renal medullary carcinoma: a case report.

BACKGROUND: Renal medullary carcinoma is a recently described, highly aggressive neoplasm that affects predominantly young African American males with a history of sickle cell trait. To the best of our knowledge, this is the first report of fine needle aspirate cytology (FNAC) findings of renal medullary carcinoma. CASE: A 14-year-old, African American male with a history of sickle cell trait presented with the sudden onset of third cranial nerve palsy. Radiographic examination demonstrated possible tumor masses in the brain, thorax and left kidney. Ultrasound-guided fine needle aspiration was performed on the left kidney, and a cytologic diagnosis of "suspect renal medullary carcinoma" was rendered. The cytologic diagnosis was confirmed by tissue examination. CONCLUSION: The cytologic features of renal medullary carcinoma include loosely cohesive clusters and single epithelioid cells with cytologic atypia, including high nuclear/cytoplasmic ratios, hyperchromasia, prominent nucleoli and cytoplasmic vacuolation. These cytologic findings, coupled with clinical findings (young black male with sickle cell trait), allow recognition of this rare renal neoplasm.

Adolescent↗