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Biomedical subjects

D Cheng

Publications and source records attributed to D Cheng.

149 records · Page 9Linked to original sources
PubMedDate not supplied

Renal cell carcinoma: correlation of CT findings with nuclear morphologic grading in 100 tumors.

The contrast-enhanced preoperative computed tomographic (CT) scans and microscopic slides of 94 patients with 100 surgically resected renal cell carcinomas (RCCs) were retrospectively and independently reviewed in order to correlate the CT imaging findings of RCC with nuclear grading. As nuclear grade increased, RCCs were more likely to be of higher stage and greater size at presentation, and appeared more heterogeneous and less marginated. Of the features analyzed, tumor margination most closely correlated with nuclear grade. Overlap in the CT appearance of individual tumors limited the potential of CT to differentiate RCCs of varying grade. Small, well-marginated, homogeneous tumors, however, were either grade I or II, and were distinguishable from the more aggressive grade III lesions, which generally displayed irregular margins and greater inhomogeneity.

Adult↗
PubMedDate not supplied

Sleep breathing and sleep movement disorders masquerading as insomnia in sexual-assault survivors.

A descriptive, hypothesis-generating study was performed with 156 female sexual-assault survivors who suffered from insomnia, nightmares, and posttraumatic stress disorder (PTSD). They completed 2 self-report sleep questionnaires to assess the potential presence of intrinsic sleep disorders. Seventy-seven percent of the sample (120 of 156) endorsed additional sleep complaints, besides their insomnia symptoms, that indicate the potential presence of sleep-disordered breathing ([SDB] 81 of 156, 52%) and sleep-related movement disorders ([SMD] 94 of 156, 60%). The potential for SDB was strongly correlated with the body mass index (BMI), an increase in arousal symptoms, and greater total PTSD severity. In some sexual-assault survivors, the relationship between sleeplessness and posttraumatic stress may be caused or exacerbated by intrinsic sleep disorders, and not be solely a function of psychophysiological insomnia--the traditional diagnostic term usually offered to explain the sleep problems associated with PTSD. Prevalence studies that use objective diagnostic evaluations such as polysomnography (PSG) are needed to test these hypotheses.

Adolescent↗
PubMedDate not supplied

Aerodynamic adsorption of permeable chemical protective suit.

A new laboratory apparatus and method were developed to test the protective ability of a permeable chemical protective suit (PCPS). The key features of this method are using a wind tunnel system and an aerodynamic model that could incorporate the complicated flow pattern around the protective clothing. This method illustrates the process of the PCPS system performance and can provide a system assessment through bench-scale experiments. A new aerodynamic adsorption equation for PCPS breakthrough curve calculation based on an aerodynamic model has been suggested, and the calculated breakthrough curves of benzene vapor on PCPS conform to the experiment curves.

Adsorption↗
PubMedDate not supplied

Comparison of the central nervous system activity of the aqueous and lipid extract of kava (Piper methysticum).

The central nervous activity of the aqueous extract of kava was examined in mice, and compared to the effect of the lipid-soluble extract. The aqueous extract caused a loss of spontaneous activity without loss of muscle tone. No hypnotic effect was seen, but some analgesia was produced. The anticonvulsant effect against strychnine was very slight and there was no evidence of local anesthetic action. There was a slight anti-apomorphine effect and tetrabenazine-induced ptosis was decreased. The lipid-soluble extract (kava resin) also decreased spontaneous motility, together with a marked reduction of motor control. Hypnosis, determined by loss of righting reflex, was produced, analgesia was marked, and a local anesthetic action evident. Kava resin also decreased apomorphine-induced hyperreactivity and partially reversed tetrabenazine-induced ptosis. Kava resin produces a greater range of pharmacological actions than the aqueous extract, and the latter is orally inactive in mice and rats. The pharmacological effects of kava ingestion appear to be due to the activity of the compounds present in the lipid-soluble fraction.

Animals↗