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Biomedical subjects

R Zhou

Publications and source records attributed to R Zhou.

At least 127 records · Page 7Linked to original sources
PubMed1998

[Relationship between plasma NO and PaO2 of artery blood in the patients with chronic pulmonary heart disease].

The plasma nitric oxide(NO) level in the 28 patients with chronic pulmonary heart disease and health controls were measured. The results showed that NO level in the exacerbating patients and stable patients was significantly lower than that in health controls. The NO level in the patients getting worse was markedly lower than that in the stable patients. The lower the oxygen pressure of the artery blood (PaO2), the lower the NO level. when the patient's situation was improving, the plasma NO level increased with rising PaO2. The plasma NO level in patients was associated with the PaO2. This study suggests that the sustained pulmonary hypertension caused by chronic hypoxia may relate to the reduction of NO synthesis and release, and that NO may play an important role in the pathogenesis in chronic pulmonary heart disease.

Aged↗
PubMed1998

[The changes and significance of the intensity of transcription of endothelial nitric oxide synthase-mRNA in placental tissue from cases of pregnancy induced hypertension].

OBJECTIVE: To determine the cause of decreasd expression of endothelial nitric oxide synthase (eNOS) in placental tissue from cases of pregnancy induced hypertension (PIH). METHODS: 9 placentae of normal pregnant women and 12 placentae of patients with PIH were studied. eNOS-mRNA was measured in placental tissue by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: (1) There was eNOS-mRNA in placental tissue of normal pregnancy as well as PIH cases. (2). The intensity of transcription of eNOS-mRNA in placental tissue of PIH cases decreased significantly when compared with that of normal pregnancy (P < 0.05). CONCLUSION: The decrease of the intensity of transcription of eNOS-mRNA in placental tissue of PIH patients may result in reduction of expression of eNOS in placental tissue of PIH.

Female↗
PubMed1998

[Experimental studies on antitumor activity of new recombinant human tumour necrosis factor in nude mice bearing nasopharyngeal carcinoma].

OBJECTIVE: Nude mice model bearing nasopharyngeal carcinoma were established using nasopharyngeal squamous carcinoma cell line (CNE-2). METHODS: New recombinant human tumor necrosis factor (NrhTNF-alpha) and carboplatin were administered locally or systemically, single or in combination. The microstructural and ultra-micro-structural changes of carcinoma after administration of NrhTNF-alpha were observed under light and electron microscopes. RESULTS AND CONCLUSION: 1. After treatment, the tumor showed hemorrhage, necrosis, regression, the survival time was prolonged. 2. Locally administered NrhTNF-alpha had more significant antitumor effect than intravenously administered of NrhTNF-alpha. 3. There is a notable synergistic antitumor effect by the combination use of NrhTNF-alpha and carboplatin. 4. Microscopy showed that cell changes mostly took place in plasma especially in mitochondria and endoplosmic reticula. The mitochondria were highly bloated. Besides, some nuclei were condensed and fragmented, resulted in cell death. These studies provide experimental basis for biological treatment of nasopharyngeal carcinoma.

Animals↗
PubMed1998

Regional, developmental, and cell cycle-dependent differences in mu, delta, and kappa-opioid receptor expression among cultured mouse astrocytes.

The diversity of opioid receptor expression was examined in astrocytes in low-density and non-dividing (confluent) cultures from the cerebral cortex, hippocampus, cerebellum, and striatum of 1-day-old mice. Mu, delta, and kappa opioid receptor expression was assessed in individual cells immunocytochemically, by using flow cytometry, and functionally by examining agonist-induced changes in intracellular calcium ([Ca2+]i). Significant spatial and temporal differences were evident in the pattern of expression of mu, delta, and kappa receptors among astrocytes. In low-density cultures, greater proportions of astrocytes expressed mu-opioid receptor immunoreactivity in the cerebral cortex and hippocampus (26-34%) than in the cerebellum or striatum (7-12%). At confluence, a greater percentage of astrocytes in cerebellar (26%) and striatal (30%) cultures expressed mu-immunoreactivity. Fewer astrocytes possessed delta-immunoreactivity in low-density striatal cultures (8%) compared to other regions (16-22%). The proportion of delta receptor-expressing astrocytes declined in the cerebellum but increased in the hippocampus. Kappa-opioid receptors were uniformly expressed by 27-34% of astrocytes from all regions, except in cortical cultures, where the proportion of kappa expressing cells was 38% at low-density and decreased to 22% at confluence. Selective mu (PLO 17; H-Tyr-Pro-Phe (N-Me) -D-Pro-NH2, delta ([D-Pen2, D-Pen5] enkephalin), or kappa (U50,488H; trans-(+/-)-3,4-Dichloro-N-methyl-N-[2-(1-pyrrolidinyl) cyclohexyl] benzeneacetamide methanesulfonate) opioid receptor agonists increased [Ca2+]i in subpopulations of astrocytes indicating the presence of functional receptors. Lastly, opioid receptor immunofluorescence varied during the cell division cycle. A greater proportion of astrocytes in the G2/M phase of the cell cycle were mu or delta receptor immunofluorescent than at G0/G1. When astrocytes were reversibly arrested in G1, significantly fewer cells expressed delta receptor immunofluorescence; however, upon reentry into the cell cycle immunofluorescent cells reappeared. In conclusion, opioid phenotype varies considerably among individual cultured astrocytes, and this diversity was determined by regional and developmental (age and cell cycle dependent) differences in the brain. These in vitro findings suggest astroglia contribute to regional and developmental idiosyncrasies in opioid function within the brain.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1997

GFRalpha-2 and GFRalpha-3 are two new receptors for ligands of the GDNF family.

The receptor for glial cell line-derived neurotrophic factor (GDNF) consists of GFRalpha-1 and Ret. Neurturin is a GDNF-related neurotrophin whose receptor is presently unknown. Here we report that neurturin can bind to either GFRalpha-1 or GFRalpha-2, a novel receptor related to GFRalpha-1. Both GFRalpha-1 and GFRalpha-2 mediate neurturin-induced Ret phosphorylation. GDNF can also bind to either GFRalpha-1 or GFRalpha-2, and activate Ret in the presence of either binding receptor. Although both ligands interact with both receptors, cells expressing GFRalpha-1 bind GDNF more efficiently than neurturin, while cells expressing GFRalpha-2 bind neurturin preferentially. Cross-linking and Ret activation data also suggest that while there is cross-talk, GFRalpha-1 is the primary receptor for GDNF and GFRalpha-2 exhibits a preference for neurturin. We have also cloned a cDNA that apparently codes for a third member of the GFRalpha receptor family. This putative receptor, designated GFRalpha-3, is closely related in amino acid sequence and is nearly identical in the spacing of its cysteine residues to both GFRalpha-1 and GFRalpha-2. Analysis of the tissue distribution of GFRalpha-1, GFRalpha-2, GFRalpha-3, and Ret by Northern blot reveals overlapping but distinct patterns of expression. Consistent with a role in GDNF function, the GFRalphas and Ret are expressed in many of the same tissues, suggesting that GFRalphas mediate the action of GDNF family ligands in vivo.

Amino Acid Sequence↗
PubMed1997

Regulation of topographic projection by the Eph family receptor Bsk (EphA5) and its ligands.

Topographic projection is a general feature of brain architecture and is critical for appropriate information processing and coding. Nevertheless, little is known about the mechanisms that govern topographic organization. The Eph family receptor tyrosine kinases and ligands have recently been implicated in the specification of topographic maps. We have shown that Bsk, an Eph family receptor, and its ligands are expressed in a complementary fashion in neurons and targets, respectively, in several neural systems. For example, in the hippocampus, Bsk is expressed in an increasing lateral to medial gradient. In contrast, at least three different ligands, viz., Elf-1, LERK3/Ehk1-L, and AL-1/RAGS/LERK7, are transcribed in complementary (opposing) gradients in the hippocampal subcortical target, the lateral septum. However, the spatial and temporal distribution of the ligands are different, such that combinatorially they specify the full target region during development. Consistent with a key role in hippocamposeptal topographic projection, the ligands selectively inhibit the growth of the topographically inappropriate medial hippocampal neurites but sustain the growth of the appropriate lateral neurites. Our studies indicate that the interaction of Bsk and its ligands restricts the receptor-positive medial neurons to the topographically appropriate, ligand-poor dorsal septal target. In addition to the hippocamposeptal system, Bsk and its ligands are also expressed in afferents and targets of several other systems, including the olfactory and the retinotectal systems. Consequently, Bsk and its ligands may play important roles in neuron-target interactions in multiple neural circuits.

Animals↗
PubMed1997

Dynamic expression suggests multiple roles of the eph family receptor brain-specific kinase (Bsk) during mouse neurogenesis.

The eph family ligands and receptors have been implicated in mediating topographic neuron-target interactions. We recently isolated Bsk, a new member of the eph family receptors, and showed that it is expressed primarily in the brain. To investigate the role of Bsk in the development of the nervous system, we examined the temporal and spatial patterns of Bsk expression using in situ hybridization. We report here that Bsk expression exhibits dynamic changes during embryogenesis. In early embryos, Bsk is widely transcribed in the nervous system, including the forebrain, midbrain, hindbrain and spinal cord. Bsk expression in the midbrain, hindbrain and spinal cord, however, gradually decreases while in the forebrain increases over time. By embryonic day 18, the most intense Bsk expression was found in the limbic system. High levels of the expression in the limbic system persisted throughout post-natal development and remained stable in the adult up to 24 month. The topography of Bsk expression is in the form of gradients in several regions of the brain, including the lateral septum, spinal cord, as well as the hippocampus. Selective expression was also observed in Purkinje cells. Our findings on the topography of Bsk expression provide support to potential roles of Bsk in topographic projection. Our analyses further suggest that there may be other novel functions of Bsk in early neurogenesis in addition to potential roles in topographic mapping.

Animals↗
PubMed1997

The intermediate layer: a morphologic study of the elastin and hyaluronic acid constituents of normal human vocal folds.

The lamina propria of vocal folds are important in voice production. We evaluated the morphologic features of elastin and hyaluronic acid, two important constituents of the lamina propria. Thirty normal human vocal folds were obtained from patients dying of traumatic causes without vocal fold injury. These tissues were immediately prepared for histologic and ultrastructural examination by standard methods. For specific study of the ultrastructure of the layers of the lamina propria, six vocal folds were divided horizontally through the midplane of the lamina propria. We found that the elastin composition of the vocal folds is variable, the largest amount being seen in the midportion on elastin-van Gieson (EVG) staining and ultrastructural evaluation. The superficial layer of the lamina propria contains fewer large elastin fibers. In this region, we found that elastin was predominantly composed of elaunin and oxytalan, which stain poorly with EVG. Using computer-assisted image analysis, we quantified the differences in elastin composition between the layers. The amount of elastin varied between men and women, and these differences could not be accurately measured by the methods employed. Hyaluronic acid was abundant especially in the midportion of the lamina propria and was significantly more abundant in men than women on quantification. The significance of these observations in normal vocal folds is discussed.

Adult↗
PubMed1997

[Thin membrane nephropathy: 27 cases].

To disclose the prevalence of thin membrane nephropathy (TMN) in China and its clinical and pathological features, we prospectively studied TMN cases including 722 cases of renal biopsies in 2 years. 27 cases (male 7 cases, female 20) were diagnosed as primary glomerulonephritis. The GBM thicknesses of TMN group (n = 27) and control group (n = 32) was 207 +/- 36 nm and 382 +/- 34 nm (P < 0.01) respectively. IF of TMN was negative or trace, near normal morphology or mild mesangial proliferative glomerulo nephritis was observed by LM. A few of them had global glomerular sclerosis or single crescent formation. All TMN patients had microscopic hematuria. About one third (9/27 cases) patients with TMN presented isolated persistent microscopic hemataria, 44.4% (12/27 cases) and 22.2% (6/27 cases) patients with TMN were accompanied with mildmoderate proteinuria and heavy proteinuria (> or = 3.5 g/24 h) or nephrotic syndrome. The patients with heavy proteinuria or nephrotic syndrome had good response to corticosteroid therapy. All patients with TMN had normal renal function, only a few of them had transient hypertension. The results showed that the prognosis of TMN would be regarded as good. The familial history of 15 patients with TMN was investigated, and 47% (7/15 cases) of them had > or = two members with microscopic hematuria in their families. TMN was found in 3.7% (27/722 cases) in total renal biopsies and 11.5% (9/78 cases) in the patients with isolated microscopic hematuria. It suggests that TMN isn't a rare kidney disease in China. Careful EM is a critical method for the correct diagnosis of TMN.

Adolescent↗
PubMed1997

[Resistant antibiotic analysis of methicillin-resistant staphylococcus].

Methicillin-resistant staphylococcus aureus is one of the important patholonic bacteria which cause nosocomial infection. In order to investigate the resistant antibiotic circumstances of this organism and hence provide foundations of prevention and treatment, we determined the resistant rates of 88 staphylococcus strains for methicillin and for other 14 kinds of commonly used antibiotics, and we determined the engendering beta-lactamase. The results showed that the isolation rate of methicillin-resistant staphylococcus aureus (MRSA) was 56%; the rate of methicillin-resistant staphylococcus coagulase-negative (MRSCoN) was 47.6%; the resistance rate and the multi-resistant rate of methicillin-resistant staphylococcus (MRS) for the 14 kinds of antibiotics were higher as compared with those of methicillin-sensitive (MSSA). Among all the tested strains, MRSA was the highest to engender beta-lactamase (92.9%); Methicillin-sensitive staphylococcus coagulase-negative (MSSCoN) was the lowest (39.4%). MRS was sensitive to vancomycin and furantoin. These suggest that when treating this bacterium, we should select these two antibiotics first.

Anti-Bacterial Agents↗
PubMed1997

[The study on analgesic effect of local-release delivery system--Huangjiabang].

Laboratory investigation was made on analgesic effect of local release delivery system, Huangjiabang, which mainly includes Chinese medical herbs. Through the application of twisting-body and thermal-plate experiments on white rats. The result showed that the pain threshold was markedly elevated (P < 0.05, P < 0.001) after the rats were fed with Huangjiabang 125 mg/kg or 250 mg/kg body weight, and the number of twisting body's animals significantly decreased (P < 0.001). The analgestic mechanism of Huangjiabang delivery system relates to its effect of invigorating the circulation of blood and accelerating the stasis assimilation, remitting the inflammation.

Analgesics, Non-Narcotic↗
PubMed1997

[Method of cyanogen bromide-fluorimetry determination of trace amount of selenomethionine in grain and blood].

Selenomethionine (SeMet) reacted with cyanogen bromide (BrCN) quantitatively forms CH3SeCN. After extracted with CHCl3, the Se of CH3SeCN is acid-digested to Se(IV). Then 2,3-diaminonaphthalene is used to determine the fluorescent Se value of 4,5-benzopiaselenol. The determination limit of this method was 3 ng/g SeMet. The accuracy of 10-500 ng Se in SeMet standard was 91.8%-97.6%. RSD was 1.9%-6.3%. Recoveries for grain and blood were 92.3%-96.7%. RSD was 2.7%-5.1%. The RSD for samples was 2.7%-9.0%. Selenocystine, selenocystiene selenite and methionine did not interfere with the determination.

Cyanogen Bromide↗
PubMed1997

[Inhibitory effects of two oligosaccharides on murine melanoma experimental metastasis].

OBJECTIVE: To observe the effects of a chemically synthesized tetrose and a natural yeast mannan on mouse melanoma experimental liver metastasis. METHODS: After treated with 4 mg tetrose (tetrose group) or 4 mg mannan (mannan group) for 30 minutes at 37 degrees C, 0.5 ml 1 x 10(6)B16-MBK melanoma cells were injected intraspleen. 55 days later, melanoma metastasis nodes in the surfaces of the liver and other organs as well as mouse survival time were observed. RESULTS: Of 6 mice in control (B16 cell+PBS), 4 died naturally within 55 days, 2 were dissected in the 55th day. All of the 6 mice had metastases in the livers, the total number of the melanoma nodes on each liver surface ranged from 2 to 30, with the largest one fused to the whole liver. One mouse had a neoplasm in the remnant site of injection, 3 had metastases in lungs, while of the 6 mice in the tetrose group, one died on the 50th day on injection. In mannan group, all of the 6 mice survived and no metastasis was seen except the largest diameter of < 1 mm of 2 liver nodes in one mouse. Neither tetrose nor mannan group had metastasis of the liver, and the weights of liver in the two groups were significantly lower than in the control. CONCLUSION: Both tetrose and mannan had the effects in blocking melanoma experimental liver metastasis, inhibiting transmigration of the liver, and prolonging the survival time of the mouse.

Animals↗
PubMed1997

[Reconstruction of lacrimal passage in repair of oblique facial cleft].

For the reconstruction of lacrimal passage in obligue facial cleft, three methods were performed in 4 cases. According to the difference in local pathology canaliculorhinestomy, transfer of vein or oral mucosa, or modified dacryocystorhinostomy was performed. The patients were followed for 6 to 12 months with satisfacting results.

Abnormalities, Multiple↗