Biomedical subjects

Z C Peng

Publications and source records attributed to Z C Peng.

24 records · Page 2Linked to original sources

PubMed1994

Sleep and timekeeping changes, and dysregulation of the biological clock in experimental trypanosomiasis.

The rest-activity and body temperature 24 hours cycles, as well as the pattern of spontaneous sleep, were investigated in rats after infection with Trypanosoma brucei brucei. In the infected rats, which were entrained to a 12 hours/12 hours photoperiod, a considerable hypokinesia was detected during the hours of darkness. In most of the infected animals, the body temperature cycle displayed a lower amplitude and an advance of about 3 hours in respect to control rats; in addition, the body temperature rhythm was not significant in some infected rats. The relative proportion of slow wave synchronized sleep, as well as the rapid-eye movement (REM) latency, were significantly reduced in the infected animals, in which sleep was considerably fragmented. The induction of Fos (the protein encoded by the immediate early gene c-fos), in response to light stimulation during the early subjective night, was severely impaired in the hypothalamic suprachiasmatic nuclei in trypanosome-infected rats. Altogether these data point out a disruption of locomotor activity and body temperature 24 hours cycle and a major disorganization of sleep during experimental trypanosomiasis. In addition, our findings indicate that the molecular and functional correlates of the synchronizing action of the suprachiasmatic nuclei, which play a major role of biological clock of endogenous biological rhythms, could be altered during trypanosome infection.

Animals↗

PubMed1993

Fos induction by nerve growth factor in the adult rat brain.

The distribution of Fos, the protein product of the immediate early gene c-fos, was studied with immunocytochemistry in the adult male rat brain after nerve growth factor (NGF) administration. NGF was injected in the lateral cerebral ventricle through a previously implanted cannula. The total number of Fos-immunoreactive (ir) neurons in the brain was 2-3 times higher after NGF administration than in control animals (untreated or injected with cytochrome c). With respect to control rats, in the NGF-treated cases Fos-ir cells were more numerous in the anterior olfactory nucleus, in the medial prefrontal and anterior cingulate cortices, in the basal forebrain, in the preoptic and ventromedial nuclei of the hypothalamus, as well as anterior hypothalamic area, in the thalamic midline nuclei, and in some brainstem structures, such as the parabrachial nucleus. The relative quantitative increase of Fos-ir neurons varied in the different structures. In addition, Fos-ir neurons were evident after NGF administration in areas devoid of immunopositive cells in control animals. These included: frontoparietal and occipital cortical fields, the hypothalamic arcuate nucleus, and many brainstem structures, such as the dorsal nucleus of the lateral lemniscus, posterodorsal tegmental, medial and lateral vestibular, ventral cochlear, and prepositus hypoglossal nuclei. These findings demonstrate that the intracerebroventricular administration of NGF can induce c-fos expression in neurons in vivo. The distribution of Fos-ir neurons indicates that NGF can induce activation of functionally and chemically heterogeneous neuronal subsets in the brain.

Animals↗

PubMed1993

[Surgery of the skull base tumor].

Surgery of the skull base tumor has been undertaken in 19 patients, 15 with anterior skull base tumor and 4 lateral skull base tumor. Among them, 16 cases had malignant tumors and 3 had benign tumors. The dura was exposed in 15 patients and resected in 5 patients due to tumor invasion. The dura and bony defects could be repaired with fascia lata, galea pericranial flaps and scalp flaps. Cautery was useful for treating minimally involved duras. Three out of 16 patients with malignant tumors were free of tumors for 4-14 years and 5 for 1.5-3 years postoperatively; 7 cases died of tumor recurrence.

Adult↗

PubMed1992

Pungent principles of ginger (Zingiber officinale) are thermogenic in the perfused rat hindlimb.

Crude extracts of both fresh and dry ginger induced the perfused rat hindlimb to consume oxygen in association with increases in perfusion pressure and lactate production. The principles responsible for these observations, the gingerols and shogaols, were isolated and tested for relative thermogenic activity. The gingerol homologues possessed greater molar potency than their shogaol counterparts. (6)-Gingerol was the most potent principle isolated, causing a mean maximal increase in oxygen consumption of 1.4 +/- 0.1 mumol/g/h (21%), an increase in lactate efflux of 4.7 +/- 0.6 mumol/g/h (87%) with a perfusion pressure increase of 7.7 +/- 0.7 mmHg (30%). Increases in alkyl chain length within each homologous series led to decreased molar potency. Specific nitro-vasodilation using glyceryl trinitrate demonstrated that thermogenesis was at least partly associated with vasoconstriction. Concurrent infusion of alpha or beta antagonists showed that neither adrenergic receptors nor secondary catecholamine release were responsible for the observed effects. Increasing doses of the ginger principles ultimately led to inhibition of steady state oxygen consumption, although perfusion pressure continued to increase. Removal of high ginger principle doses was followed by apparent increases in oxygen uptake unaccompanied by elevated perfusion pressure. As a consequence, the effective concentration ranges of the ginger principles were relatively narrow. The cause of high dose effects is as yet undetermined but may have been due in part to disruption of mitochondrial function.

Animals↗

PubMed1987

Distribution of catecholamine-containing cell bodies in the human diencephalon.

The distribution and morphological characteristics of catecholamine (CA)-containing cell bodies in the diencephalon of 7-9-month-old fetuses were studied by means of the Faglu histofluorescence method. Although the general distribution of CA cell bodies in human diencephalon observed in the present study is similar to that in other mammals, there are some significant differences. A great number of CA neurons lie within the lateroventral hypothalamic zone. There are more numerous larger CA neurons distributed outside the periventricular gray in the human diencephalon.

Catecholamines↗

PubMedDate not supplied

ESR dating of tooth enamel: comparison with U-series, FT and TL dating at the Peking man site.

Deer tooth samples from Zhoukoudian, the Peking Man Cave, were studied. Non-linear fitting is used to determine AD, from which ESR ages were calculated by both the disequilibria model (DU) and linear uptake model (LU). Comparison of ESR ages with those from U-series, FT and TL methods show that the enamel of deer teeth is a suitable material for ESR dating.

Animals↗