Biomedical subjects

K Hu

Publications and source records attributed to K Hu.

150 records · Page 9Linked to original sources

PubMedDate not supplied

Metabolism of polychlorinated dibenzo-p-dioxins and related dioxin-like compounds.

Recent work on the metabolism of polychlorinated dibenzo-p-dioxins and related compounds such as polychlorinated dibenzofurans and coplanar polychlorinated biphenyls is reviewed. Most in vivo studies and epidemiological studies on humans have been concerned with rates of elimination of these compounds; in vitro work has shown that a wide variety of metabolites can be found, either in hydroxylated format (typically in feces) or as conjugates (in urine). Metabolism of this group of compounds seems always to represent a detoxification process rather than one of bioactivation.

Animals↗

PubMedDate not supplied

Mechanisms of reversal of adriamycin resistance in human ovarian carcinoma cell line by ultrasound.

The aim of this study was to investigate the reversal of adriamycin resistance in human ovarian cancer cells by ultrasound exposure from perspectives of apoptosis and mdr1 gene. Apoptosis was determined by flow cytometry and mdr1 level by reverse transcription-polymerase chain reaction (RT-PCR). Apoptosis indexes were improved in groups in which ultrasound exposures were applied. RT-PCR did not support that insonation-decreased mdr1 level. These findings suggested that the ultrasound-enhanced therapeutic efficacy was not mediated via modulating gene expression, and ultrasound maybe lowered thresholds for apoptosis and oncosis in chemoresistant ovarian cancer cells.

Antineoplastic Agents↗

PubMedDate not supplied

Ultrastructure alterations in adriamycin-resistant and cisplatin-resistant human ovarian cancer cell lines exposed to nonlethal ultrasound.

Human ovarian cancer cell lines, SKOV3 and its adriamycin-resistant substrain SKOV3/ADR and COC1 and its cisplatin-resistant substrain COC1/DDP, were exposed to nonlethal ultrasound. Ultrastructures in sham-insonated and insonated cells were inspected by transmission electron microscopy, and cytochrome C in cytosol was determined by enzyme-linked immunosorbent assay. Ultrasound exposure led to no significant changes in SKOV3/ADR cells, but tumid mitochondria occurred in SKOV3 cells. Mitochondria changes were also detected in some exposed COC1 and COC1/DDP cells. Apoptotic bodies could be detected in either control or insonated COC1/DDP cells. A few exposed COC1/DDP cells became reticular. Cytochrome C in cytosol in exposed SKOV3/ADR cells was increased but that in exposed COC1/DDP cells was decreased. These findings revealed that the bioeffect of ultrasound on chemosensitive cells was not identical to that of chemoresistant ones, and ultrasound was a potential approach for treatment of drug-resistant ovarian cancers.

Antibiotics, Antineoplastic↗

PubMedDate not supplied

Expression of estrogen receptors ERalpha and ERbeta in endometrial hyperplasia and adenocarcinoma.

We assessed the expression of estrogen receptors (ER)alpha and ERbeta in 114 human endometrial hyperplasia and adenocarcinomas. The aim of this study was to determine the expression of both ER isoforms in human endometrial tissue by immunohistochemistry. From normal proliferation to simple and complex hyperplasia, the expression of ERalpha was increased (P < 0.05), while ERbeta did not change much (P > 0.05). In atypia hyperplasia and adenocarcinoma, both ERalpha and ERbeta were decreased significantly (P < 0.05). Most endometrial adenocarcinomas expressed ERalpha, either alone or in combination with ERbeta, and the ERbeta/ERalpha ratio was decreased when compared to normal proliferation (P < 0.05). Also, we found that the expression of ERalpha and ERbeta has no relationship with the status of lymph node of adenocarcinoma (P > 0.05). Both ERalpha and ERbeta play an important role in endometrial hyperplasia and carcinomas, the levels of ERalpha and ERbeta appear be used as prognostic indicators.

Adenocarcinoma↗

PubMedDate not supplied

Bechterew decompensation.

A right labyrinthectomy was performed in rats 5 months after a left labyrinthectomy. Spontaneous compensation of balance functions after both operations was assessed by observing nystagmus, rolling about the longitudinal axis, circular walking and head tilt. Decompensation, induced by brief halothane-NO anaesthesia, released predominantly symptoms characteristic for the period after the first labyrinthectomy. Bechterew symptoms could, however, also be decompensated. It is concluded that Bechterew compensation does not re-establish balance in the central vestibular system. Dysbalance and vertigo of vestibular origin is thus conceivable in patients after all peripheral vestibular function has been lost.

Animals↗

PubMedDate not supplied

The cytotoxicity of methyl protoneodioscin (NSC-698791) against human cancer cell lines in vitro.

Methyl protoneodioscin (NSC-698791) is a furostanol saponin isolated from the rhizome of Dioscorea collettii var. hypoglauca (Dioscoreaceae), a Chinese herbal remedy for the treatment of cervical carcinoma, carcinoma of the urinary bladder and renal tumor for centuries. In order to systematically evaluate its potential anticancer activity, methyl protoneodioscin cytotoxicity was tested in vitro against 60 human cancer cell lines in the NCI's (National Cancer Institute, USA) anticancer drug screen. As a result, methyl protoneodioscin was cytotoxic against all the test cell lines from leukemia and solid tumors in the NCI's human cancer panel, especially selectively against one non-small cell lung cancer (NSCLC) line (A549/ATCC), one colon cancer line (HCT-116), two central nenous system (CNS) cancer lines (SF-539 and SNB-75), one melanoma line (M14), one renal cancer line (CAKI-1), one prostate cancer (DU-145) and two breast cancer lines (HS 578T and MDA-MB-435) with GI50 < or = 2.0 microM. The selectivity between these nine most sensitive lines and the least sensitive line (TK-10) was from 22- to 30- fold. In the same cancer subpanel, a selectivity at GI50 level of more than 15-fold was observed between A549/ATCC and EKVX (NSCLC), between CAKI-1 and TK-10, A498 (renal cancer), respectively. In general the CNS cancer was the most sensitive subpanel, while renal cancer was the least sensitive subpanel. Based on an analysis of COMPARE computer program with methyl protoneodioscin as a seed compound, no compounds in the NCIs anticancer drug screen database have similar cytotoxicity patterns (mean graphs) to that of methyl protoneodioscin, indicating a potential novel mechanism of anticancer action involved.

Antineoplastic Agents, Phytogenic↗