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Biomedical subjects

Z H Liu

Publications and source records attributed to Z H Liu.

At least 91 records · Page 5Linked to original sources
PubMed1990

Conversion of pregnenolone to progesterone by mouse morulae and blastocysts.

When mouse morulae, early blastocysts and implanting blastocysts were cultured with tritiated pregnenolone, tritiated progesterone and its metabolites, 5 alpha-pregnan-3,20-dione and 3 alpha-hydroxy-5 alpha-pregnan-20-one, were isolated from the medium. It appears that mouse embryos can make progesterone from pregnenolone and the progesterone is quickly metabolized into various metabolites. These abilities increase with development. It is suggested that the mouse embryo can make progesterone and may regulate its own progesterone level for optimal development.

5-alpha-Dihydroprogesterone↗
PubMed1989

Viral etiology of cervical carcinoma. Human papilloma virus and herpes simplex virus type 2.

The possible role of human papilloma virus (HPV) and herpes simplex virus type 2 (HSV-2) in the viral etiology of cervical carcinoma was investigated a series of cervical lesions were studied for the presence of HPV and HSV-2 DNA sequences as well as HPV and HSV-2 antigens by DNA dot blot hybridization technique and high-specificity PAP staining method. The results obtained were correlated with the histologic diagnosis. HPV 16 DNA sequences detected in cervical carcinoma biopsies were 43%, whereas HSV-2 DNA sequences were only 8%. HPV antigens detected in cervical dysplasia were 31%, whereas those detected in cervical carcinoma and cervicitis were the least. HSV-2 antigens were detected in chronic cervicitis, dysplasia and cervical carcinoma. The difference in positive rate between the cervical carcinoma and cervicitis groups was statistically significant, (chi-square test, P less than 0.01). No HPV DNA and HSV-2 DNA sequences were found in the same specimen, although both HPV DNA sequences and HSV-2 antigens were found in the same sample in some cases. The results indicate that the viral etiology of cervical carcinoma may be multifactorial. Both HSV-2 and HPV may be associated with cervical carcinoma, but the mechanisms involved are different. HSV-2 and HPV may act synergistically in the development of cervical carcinoma.

Antigens, Viral, Tumor↗
PubMed1989

[Thin-layer chromatography of mycolic acids methanolysates of whole-cell in Mycobacterium and related bacteria].

Mycolic acid methanolysates of whole-cell in Mycobacterium and related bacteria were analysed by thin-layer chromatography. The experimental results show that five of twenty-two species, M. tuberculosis, M. bovis, M. kansasii, M. marinum and M. gastri have similar pattern of mycolates, composed of alpha-mycolates, methoxymycolates, ketomycolates and two unknown components. M. gilvum, M. phleri, M. avium, M. intracellulare, M. xenopi and M. nonchromogenicum contain alpha-mycolates, ketomycolates and wax-ester. The patterns of TLC for other tested species were different from each other. Nocardia, Rhodococcus and Corynebacterium show a relatively simple pattern which principally contain alpha-mycolates. The four genus can be differentiated. Spots of mycolic acids of nine strains Mycobacterium sp. isolated from patients in this hospital were similar to M. tuberculosis. These strains were also identified to the same result as above by traditional methods. The method is of value in the classification and identification of Mycobacterium.

Chromatography, Thin Layer↗
PubMed1988

Chemical speciation and distribution of arsenic in water, suspended solids and sediment of Xiangjiang River, China.

The forms of arsenic in the Zuzou Zone of the Xiangjang River are evaluated. Nine fractions of arsenic, consisting of soluble arsenic(III) and total soluble arsenic, loosely bound arsenic, aluminium arsenate, iron arsenate, calcium arsenate, arsenic occluded on iron oxide, organic compounds of arsenic and residual arsenic, were separated from suspended solids and sediments by sequential chemical extraction. All arsenic fractions were determined by ASV and AFS. The distributions of arsenic and arsenic fractions in water, sediments and suspended solids are discussed in terms of the mechanisms of arsenic transport and deposition in aquatic ecosystems.

Arsenic↗
PubMed1987

[Kinetic observation and analysis of the radioactivity distribution of 125I-labelled F(ab')2 fragments of monoclonal antibody against human lung cancer cells in normal mice].

Radioactivity distribution of 125I-labelled F(ab')2 fragments in 14 organs and tissues of normal mice for 11 time-phases from 0.5 hour to 7 days after injection was observed. The radioactivity-time curves of these organs and tissues were divided into three types according to their characteristics: excreting type (blood and liver), absorbing type (thyroid), absorbing-excreting type (the other organs and tissues). The organs fully perfused with blood had shorter peak-time and higher peak-value, such as heart, lung, kidney and liver. All of the peak-times were equal to or less than 2 days after injection, therefore the image taking should be kept away from this period. The excreting rate constants of slow metabolic component were similar for various organs and tissues except thyroid and brain. The brain had a low peak in the curve and small excreting rate constant. It was demonstrated that F(ab')2 fragments were able to penetrate the blood-brain barrier but absorption and excretion were slower compared with the other organs and tissues. The radioiodine was obviously concentrated in the subcutaneous tissue, which may have been the main cause of the subcutaneous tissue tumor induced by radioiodine. The radioactivity-time curve in which the peak value and inflect point existed simultaneously shows that radioactivity metabolism after injection of 125I-F(ab')2 follows three compartment models. The biological meanings corresponding to three sections of the blood radioactivity-time curve are pure distribution, distribution-recycle and catabolic-excretory phases, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

The cells of origin of the aberrant recrossed retinotectal projection in the rat.

The cells of origin of the aberrant recrossed retinotectal projection induced by neonatal unilateral eye enucleation and collicular lesion in rats were studied using horseradish peroxidase and fluorescent dyes as pathway tracers. The results showed that labelled ganglion cells which gave rise to the recrossed retinotectal projection were distributed in almost the entire area of the remaining retina. However, more labelled cells were observed in the nasal than in the temporal half of the retina, and very few cells contributing to the recrossed projection were located in the lower temporal retinal crescent where cells of the uncrossed retinotectal fibers were heavily concentrated. In addition, a small number of recrossed retinotectal fibers were found to arise from ganglion cells which simultaneously sent out uncrossed retinotectal fibers terminating in the same remaining colliculus.

Animals↗
PubMed1986

Displaced retinal ganglion cells in normal rats and rats with one eye enucleated at birth.

The displaced retinal ganglion cells in normal rats and rats with left eye enucleated at birth were studied using the fluorescent dye Fast blue as neuronal marker. The dye was introduced to the right optic tract of the rats 7 days before perfusion. Frozen coronal sections of the brains and retinal whole-mounts from all rats were examined under ultraviolet illumination. In the normal rat, the displaced cells constituted 0.91% and 2.07% of the entire population of cells projecting to the contralateral and ipsilateral side of the brain, respectively. While the contralaterally projecting displaced cells were widely distributed in the retina, the ipsilateral ones concentrated mainly in the temporal retinal crescent in all rats studied. However, an increase in the number of the ipsilaterally projecting displaced cells was detected in unilaterally enucleated rats as compared to that observed in normal animals.

Animals↗
PubMed1986

Study on late effects of radioiodine on rats.

This paper describes the results observed on 850 male Wistar rats for two years after intraperitoneal injection with 131I, 132I or 125I of different radioactivities. The incidence of thyroid malignant tumor was 45.8% when the dose absorbed by the thyroid gland was 7.8 Gy in the 131I groups, and even tumors of lung and soft tissue, and malfunction of kidney and immune organs could be elicited when the radioiodine was overdosed. Both 132I and 125I have their optimal carcinogenic dose ranges and optimal doses of carcinogenesis. As the dosage decreases to a certain level, a low-limit dose incapable of inducing cancers may be present. 131I induced mainly papillary and mixed type carcinomas, 132I chiefly follicular and undifferentiated type carcinomas, while 125I induced follicular and medullary carcinomas. The paper also discusses cytochemical DNA quantitative assays of different histological types of thyroid gland carcinomas, holding that reference to such data as decreasing serum T4, elevating serum TSH and CIC may be helpful for early diagnosis of thyroid carcinomas.

Adenocarcinoma↗