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Biomedical subjects

C Jin

Publications and source records attributed to C Jin.

193 records · Page 11Linked to original sources
PubMed1987

Acute tachycardia and pressor effects following injections of kainic acid into the antero-dorsal medial hypothalamus.

The responses of systemic arterial blood pressure and heart rate to intra-cerebral injections of the excitatory neurotoxin, kainic acid, were examined in urethane-anesthetized rats. Injections of kainic acid into the antero-dorsal medial hypothalamus produced dose-related increases in both blood pressure and heart rate over a range of 30-1000 ng. Exophthalmos, mydriasis, increased respiratory rate and movements of the vibrissae were also noted. Injections of 1000 ng of kainic acid into the antero-dorsal medial hypothalamus produced significantly greater increases in blood pressure and heart rate than comparable injections of equimolar doses of the excitatory neurotoxins, quisqualic acid, N-methyl-D-aspartic acid or quinolinic acid. No differences in the magnitude of the cardiovascular responses to 1000 ng of kainic acid were detected between injections directed towards the paraventricular nucleus of the hypothalamus (PVN), lateral hypothalamus or lateral cerebral ventricle. In contrast, at doses of 30 ng, injections directed towards the paraventricular nucleus produced significantly greater responses than comparable injections into the lateral hypothalamus, medial thalamus or lateral cerebral ventricle. The distribution of radiolabelled kainic acid at this dose was found to extend ipsilaterally in the medial hypothalamus as far as 1 mm rostral and caudal to the injection site. The results suggest that excitation of neuronal cell bodies within the medial hypothalamus by excitatory neurotoxins produces acute increases in blood pressure and heart rate. However, widespread diffusion of kainic acid, in particular, was documented and caution in interpretation of the results produced by local intra-cerebral injections of this agent is recommended.

Animals↗
PubMed1987

Leukaemia in benzene workers: a retrospective cohort study.

A retrospective cohort study was conducted in 233 benzene factories and 83 control factories in 12 cities in China. The benzene cohort and the control cohort consisted of 28,460 benzene exposed workers (178,556 person-years in 1972-81) and 28,257 control workers (199,201 person-years). Thirty cases of leukaemia (25 dead and 5 alive) were detected in the former and four cases (all dead) in the latter. The leukaemia mortality rate was 14/100,000 person-years in the benzene cohort and 2/100,000 person-years in the control cohort; the standardized mortality ratio was 5.74 (p less than 0.01 by U test). The average latency of benzene leukaemia was 11.4 years. Most (76.6%) cases of benzene leukaemia were of the acute type. The mortality due to benzene leukaemia was high in organic synthesis plants followed by painting and rubber synthesis industries. The concentration of benzene to which patients with a leukaemia were exposed ranged from 10 to 1000 mg/m3 (mostly from 50 to 500 mg/m3). Of the 25 cases of leukaemia, seven had a history of chronic benzene poisoning before the leukaemia developed.

Adult↗
PubMed1987

Occupational exposure to benzene in China.

Of a total of 528,729 workers exposed to benzene or benzene mixtures in China, 508,818 (96.23%) were examined. Altogether 2,676 cases of benzene poisoning were found, a prevalence of 0.15%. A higher prevalence of benzene poisoning was found in the cities of Hangjou, Hefei, Nanjing, Shenyang, and Xian. The geometric mean concentration of benzene in 50,255 workplaces was 18.1 mg/m3 but 64.6% of the workplaces had less than 40 mg/m3. There was a positive correlation between the prevalence of benzene poisoning and the concentration in shoemaking factories. The prevalence of benzene induced aplastic anaemia in shoemakers was about 5.8 times that occurring in the general population. The results of this investigation show the need for a practicable hygiene standard to prevent benzene poisoning.

Adult↗
PubMed1986

Cellular localization of proglucagon/glucagon-like peptide I messenger RNAs in rat brain.

Techniques of in situ hybridization histochemistry, Northern blot hybridization, and immunocytochemistry were used to investigate the biosynthesis of glucagon-like immunoreactants (GLIs) in rat brain. Cells in the nucleus tractus solitarius of the medulla oblongata of adult rat brain hybridized to a synthetic oligonucleotide probe (GLP-I oligomer) corresponding to nucleotide sequences in pancreatic proglucagon mRNA encoding glucagon-like peptide I (GLP-I), and stained with antisera specific for two antigenic determinants of pancreatic proglucagon, glucagon, and GLP-I. These data suggest that there is de novo synthesis of proglucagon in cells of the nucleus tractus solitarius via expression of a proglucagon mRNA similar to that produced in pancreas. Previous studies have shown that cells in hypothalamus stain with GLP-I antisera, but not with glucagon antisera. However, cells in the hypothalamus did not hybridize with the GLP-I oligomer and may therefore produce a GLP-I immunoreactant that is encoded by a mRNA different from the pancreatic proglucagon-mRNA-encoding glucagon and GLP-I. Northern blot hybridizations with a cDNA probe encoding the entire pancreatic proglucagon sequence did not detect proglucagon/GLP-I mRNAs in polyadenylated RNAs (Poly A RNA) from adult rat brainstem and hypothalamus, probably because of their low abundance. Poly A RNAs from fetal rat brain, however, contained two mRNAs that hybridized to the proglucagon cDNA probe. One mRNA of 1,300 bases is the same size as pancreatic proglucagon mRNA. The second mRNA of 1,500 bases may encode the GLP-I immunoreactant detected in the hypothalamus of adult rat brain. The presence of neurons with glucagon and glucagon-like peptides in the nucleus tractus solitarius suggests a role of these peptides in gustatory and/or cardiopulmonary control.

Animals↗
PubMed1986

Possible ethnic difference in toluene metabolism: a comparative study among Chinese, Turkish and Japanese solvent workers.

Toluene metabolism was studied in 192 Chinese workers in comparison with that in 130 Japanese and 17 Turks. Time-weighted average concentrations of toluene in the breathing zone of workers were measured utilizing passive dosimeters, and hippuric acid (HA) and omicron-cresol (omicron C) concentrations in shift-end spot urine samples by high-performance liquid chromatography (HPLC) and gas chromatography (GC), respectively. Under similar exposure conditions, male Japanese excreted almost twice as much HA as male Chinese, although such difference was less marked between female Chinese and Japanese. In contrast, the excretion of oC did not differ between the two ethnic groups. The ratio of oC over HA was highest among Turkish workers followed by Chinese, and lowest among Japanese. Possible roles of differences in toxicogenetics as well as in life patterns were discussed.

China↗
PubMed1986

Quantitative relation of urinary phenol levels to breathzone benzene concentrations: a factory survey.

Urine samples were collected from 64 men and 88 women in shoe factories and printing plants at the end of a seven hour day shift in the latter half of a week in spring. Urine samples were also taken from 43 men and 88 women in the same factories but who were not exposed to solvents. Exposure to benzene during the shift was monitored by passive dosimeters. Both phenol in urine and benzene in activated carbon were analysed with FID gas chromatographs. The urinary concentrations of phenol were linearly related to the time weighted average concentrations of benzene in the breathzone air; the variation was so small that those exposed to 10 ppm benzene could be separated from the non-exposed at least on a group basis when the phenol concentration was corrected either for creatinine concentration or for specific gravity. The urinary phenol concentrations corresponding to 10 ppm benzene were 47.5 mg/l (as observed), 57.9 mg/g creatinine, or 46.6 mg/l (specific gravity 1.016).

Adult↗
PubMed1979

Formation of carcinogenic N-nitroso compounds in corn-bread inoculated with fungi.

DMNA, DENA and MBNA are formed in corn-bread which has been inoculated with the most common species of fungi found in foodstuffs of Lin Xian County, Henan Province, such as F. moniliforme, A. flavus and others, and then, added with small amount of NaNO2 after a few days of incubation. These carcinogenic N-nitroso compounds can induce cancer of the liver or/and esophagus in experimental animals. Results of the present study show the capability of some fungi to produce chemical carcinogens as well as mycotoxins in contaminated food, and thus, open a new field of research in cancer etiology.

Aspergillus flavus↗
PubMedDate not supplied

Consultation-liaison psychiatry training and supervision results in fewer recommendations for constant observation.

In this study, we tested two hypotheses. First, that consultation-liaison (C-L)-trained psychiatry residents would order constant observation (CO) less frequently than psychiatry residents untrained in C-L. Second, we predicted that CO would be ordered less frequently under circumstances when experienced C-L psychiatry attending and fellows would be available to supervise psychiatry residents training in C-L. We reviewed a total of 138 consultations during a 6-month period. Constant observation was recommended in 31 cases (22.5%). Consultations were done by residents who had received training in C-L psychiatry (n=34) and by residents who were not trained in C-L (n=34). Residents not trained in C-L had a significantly higher percentage of CO orders (44.1%) compared to those trained in C-L (15.4%) (chi(2)=12.1, df=1, P<0.001). Because C-L-trained residents provided regular-hour and after-hour consults while residents without C-L training provided only after-hour consults, we also separately analyzed data from the 102 after-hour cases. We again found that residents with C-L training had a significantly lower rate of ordering CO (22.1%) than those who had not yet received C-L psychiatry training (44.1%) (chi(2)=5.31, df=1, P<0.05). We also found that C-L-trained residents ordered CO less frequently during regular hour consults (2.8%) when experienced staff are available in supervision compared to after hours (22.1%) (chi(2)=6.72, df=1, P<0.01). Our findings suggest that training in C-L psychiatry has a significant impact on the use of constant observation for patients in the general hospital thereby reducing the cost of care.

Adult↗
PubMedDate not supplied

A field emission SEM and HVTEM study of collagen fiber bundles in the lamina propria of the palatine mucosa in the developing mouse.

The ultrastructural development of the surface belonging to the epithelium-connective tissue interface of the hard and soft palatine mucosa of mouse was studied using field emission scanning electron microscopy and high voltage transmission electron microscopy methods. The tissues were analysed at 18 days of gestation, and, 1, 3, 7, 14, 21, 30 and 90 days after birth. The three-dimensional architecture of the connective tissue in the lamina propria showed different shapes. The papillae began to form on days 7 and 14 but continued to growth until the adult period. Different stages of primary and secondary connective tissue papillae were recognized in the hard palatine mucosa whereas the soft palate showed erect connective tissue papillae, small round formations containing taste buds and several openings of the salivary glands ducts.

Aging↗
PubMedDate not supplied

Growth of Candida species on commercial denture adhesives in vitro.

PURPOSE: Although denture adhesives are widely used by the elderly, it is unknown whether denture adhesives support microbial growth. Therefore, we investigated the growth of Candida species on six commercial denture adhesives. MATERIALS AND METHODS: The growth of a single isolate of C albicans and C tropicalis on six commercial denture adhesives was investigated by monitoring pH changes in growth media. RESULTS: In the preliminary study, the effect of each product on the pH value of the medium was examined; a single product itself significantly reduced the pH of medium below 5.0. When the yeast was grown on the materials, the pH changes in the media varied depending on the adhesive materials and, to a greater or lesser extent, on whether they showed antifungal activity. Two products (Cushion Collect and Collect Soft A) significantly suppressed C albicans growth (P < 0.01), and one product (Collect Soft A) effectively reduced C tropicalis growth (P < 0.01). CONCLUSION: Our results suggest that denture adhesives possess antifungal activity to a greater or lesser degree. However, one product caused the reduction of pH below 5.0. Thus, in the daily use of denture adhesives, attention should be paid to both the materials and their microbiologic properties.

Acrylic Resins↗
PubMedDate not supplied

Effects of some natural products as components of Chinese herbal medicines on mammary gland growth and function in mice.

As a possible step to evaluate the role in the mammary glands of the scales of Guanshanjia, the fruits of Lulutong and the seeds of Wangbuliouxing, which are the natural products used widely as the components of herbal medicine in China for the improvement of lactation and the therapy of breast disorders, the effects of these agents on mammary gland growth and function were studied in female mice. The chronic administration of each agent in drinking water improved several parameters; however, the mode of action differed markedly among agents. The results indicate the necessity of acquiring enough knowledge of the characteristics of each agent for the efficient prescription of herbal medicine as well as the single use of the agent.

Animals↗
PubMedDate not supplied

Development of mouse submandibular gland studied by field emission scanning electron microscopy.

The ultrastructural organization of mouse submandibular gland from 15 days gestation to 180 days of age was studied by field emission scanning electron microscopy. At 15 days of gestation several groups of acini, intercalated and striated ducts were present. They consisted of numerous pyramidal and/or polyhedral cells with spherical or elongated nuclei and short microvilli. At 3 days after birth different shapes of acinar structures covered by a network of fine collagen bundles were observed. The acinar portions corresponded to the terminal tubules and showed the acinar cells containing immature secretory granules. Fractured specimens of ducts revealed a flat surface with large central nuclei. At 14 days after birth acinar terminal portions possessed a round shape; branches of either intercalated and striated ducts were also observed. Gap junctions and interdigitations were numerous at the base of acinar cells. At 30 days after birth the acinar terminal portions and striated ducts revealed a large number of secretory granules. Acinar cells showed a pyramidal shape and basal nuclei. Freeze-cracked surfaces of the striated ductal cells evidenced also a pyramidal shape. Secretory granules ranged from 0.3 to 1.2 microns in size and were clearly observed by infoldings of the basement membranes. At 90 days after birth the ultrastructural features were more differentiated when compared with the previous ages. The freeze-cracked specimens showed very numerous secretory granules in all acinar and striated ductal cells. The granules occupied almost all the apical region of the cells. The outer surface of the basement membrane of acinar and myoepithelial cells was constituted by a spongy-like material covered by fine collagen fibrils. At 180 days after birth numerous secretory granules were seen either in acinar and ductal cells. A morphofunctional polarization of the cell was finally clearly observed in that the cytoplasmic organelles were concentrated in the basal portion whereas the secretory granules were located in the apical region of the cells.

Animals↗