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Biomedical subjects

H Jin

Publications and source records attributed to H Jin.

At least 253 records · Page 14Linked to original sources
PubMed1991

Localization of substance P-like immunoreactivity in guinea pig vestibular endorgans and the vestibular ganglion.

The immunocytochemical distribution of substance P (SP) in guinea pig vestibular endorgans and the vestibular ganglion was investigated. Two kinds of SP-immunoreactive fibers were distinguished. Most were thick, and found around or beneath sensory hair cells. These SP-immunoreactive fibers were distributed predominantly on the slope of the crista and the peripheral region of the macula. By electron microscopy, we confirmed this type of SP-like immunoreactivity to be restricted within primary afferent neurons. Some vestibular ganglion cells also showed SP-like immunoreactivity, suggesting that SP is present in some primary afferent neurons, and is involved in afferent neurotransmission. The characteristic distribution of SP may indicate functional differences within each endorgan. The other group of immunoreactive nerve fibers, varicous thin fibers, could be found in the stroma of vestibular endorgans, nerve trunk, vestibular ganglion, and along blood vessels of the vestibular ganglion. These fibers may have a different origin, and have an influence on blood flow and certain other functions.

Animals↗
PubMed1991

Expression of functional Bunyamwera virus L protein by recombinant vaccinia viruses.

A cDNA containing the complete coding sequence of the Bunyamwera virus (family Bunyaviridae) L genome segment has been constructed and cloned into two recombinant vaccinia virus expression systems. In the first, the L gene is under control of vaccinia virus P7.5 promoter; in the second, the L gene is under control of the bacteriophage T7 phi 10 promoter, and expression of the L gene requires coinfection with a second recombinant vaccinia virus which synthesizes T7 RNA polymerase. Both systems express a protein which is the same size as the Bunyamwera virus L protein and is recognized by a monospecific L antiserum. The expressed L protein was shown to be functional in synthesizing Bunyamwera virus RNA in a nucleocapsid transfection assay: recombinant vaccinia virus-infected cells were transfected with purified Bunyamwera virus nucleocapsids, and subsequently, total cellular RNA was analyzed by Northern (RNA) blotting. No Bunyamwera virus RNA was detected in control transfections, but in cells which had previously been infected with recombinant vaccinia viruses expressing the L protein, both positive- and negative-sense Bunyamwera virus S segment RNA was detected. The suitability of this system to delineate functional domains within the Bunyamwera virus L protein is discussed.

Animals↗
PubMed1991

Atrial natriuretic peptide in acute hypoxia-induced pulmonary hypertension in rats.

To test the hypothesis that exogenous atrial natriuretic peptide (ANP) prevents the acute pulmonary pressor response to hypoxia, ANP (20-micrograms/kg bolus followed by 1-microgram.kg-1.min-1 infusion) or vehicle was administered intravenously to conscious rats beginning 3 min before exposure to hypoxia or room air for 90 min. Exogenous ANP abolished the acute pulmonary pressor response to hypoxia in association with marked and parallel increases in plasma ANP and guanosine 5'-cyclic monophosphate (cGMP) and with a significant increase in lung cGMP content. To examine whether endogenous ANP modulates the acute pulmonary pressor response to hypoxia, rats were pretreated with a monoclonal antibody (Ab) to ANP and exposed to hypoxia. Mean pulmonary arterial pressure (MPAP) in the Ab-treated rats was not different from control over the first 6 h of hypoxic exposure. Thereafter, the Ab-treated group had significantly higher MPAP than control. Our data suggest that 1) exogenous ANP blocks the pulmonary pressor response to acute hypoxia via stimulation of cGMP accumulation in the pulmonary vasculature, and 2) endogenous ANP may modulate the subacute, but not acute, phase of hypoxic pulmonary hypertension.

Acute Disease↗
PubMed1991

[A study on the inhibition effect of tetrandrine on the pingyangmycinum induced pulmonary fibrosis].

A model of pulmonary fibrosis caused by a single intratracheal injection 0.1 mg pingyangmycinum in mice was reported. The effect of tetrandrine, a herbal powder, 50 mg/kg time, on the pathological development of pulmonary fibrosis, and the activity of superoxide dismutase (SOD), angiotensin converting enzyme (ACE), quantity of hydroxyproline (HYP) in this mice model were investigated. We also contrast tetrandrine with cortisol. The result showed that tetrandrine may inhibit the formation and development of pulmonary fibrosis. On the other hand, tetrandrine and cortisol may increase the activity of SOD of lung tissue, reduce the quantity of HYP of lung tissue and decrease the activity of serum ACE.

Alkaloids↗
PubMed1991

[Chemical constituents of the aerial parts of six species of Bupleurum genus medicinally used in south-west region of China].

The chemical constituents of the aerial parts of six species of Bupleurum genus (B. kunmingense, B. polyclonum, B. wenchuanense, B. longicaule var. franchetii, B. rockii and B. chaishoui) medicinally used in south-west region of China have been investigated with the results of obtaining eight flavonoid compounds and six triterpenoid saponins. The aglycones of these eight flavonoid compounds are quercetin and isorhamnetin, which are different from the aglycones of the flavonoid compounds isolated from the aerial parts of B. chinense, the official species in Chinese Pharmacopoeia. In the latter case, the aglycone is kaempferol. This difference may be of chemotaxonomic value in Bupleurum genus.

Antiviral Agents↗
PubMed1990

The prevalence of dementia and Alzheimer's disease in Shanghai, China: impact of age, gender, and education.

We report the prevalence rates for dementia and Alzheimer's disease (AD) obtained from a probability sample survey of 5,055 noninstitutionalized older persons in Shanghai, China. A two-stage procedure was used for case finding and case identification. A Chinese version of the Mini-Mental State Examination was used to determine cases of possible dementia. Three different cutoff points on this mental status test were used depending on the respondent's level of education. Clinical evaluations, based on functional assessments and psychiatric interview, medical and neurological examinations, three standardized mental status tests, and a selected group of psychometric tests, were made in the second stage of the study to ascertain the clinical diagnosis of dementia and AD utilizing the Diagnostic and Statistical Manual for Mental Disorders, edition 3 and National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria, respectively. The prevalence rate of dementia in persons 65 years and older was 4.6%. Clinically diagnosed AD accounted for 65% of the subjects with dementia. These findings indicate that the prevalence of dementia in Shanghai is very much higher than figures published earlier for China and Japan, and at the lower part of the range of values reported for community residents in the United States and other Western countries, but less than half of that reported in the recently published survey of the elderly in East Boston. Increasing age, gender (female), and low education are each highly significant and independent risk factors for dementia. One hypothesis to explain the increased prevalence in elderly women who had received no formal education invokes the possibility of an effect of early deprivation, perhaps lowering brain "reserve," allowing the symptoms of dementia to appear at an earlier date during disease progression.

Age Factors↗
PubMed1990

Atrial natriuretic peptide clearance receptor agonist lowers pulmonary pressure in hypoxic rats.

We demonstrated previously that intravenous administration of exogenous atrial natriuretic peptide (ANP) lowers mean pulmonary arterial pressure (MPAP) in hypoxia-adapted rats. To test the hypothesis that endogenous ANP may also lower MPAP in this model, C-ANP-(4-23), a ring-deleted analogue of ANP that binds to the biologically silent ANP clearance receptor (C-ANP receptor) but not to the ANP biological receptor (B-ANP receptor), was administered intravenously as a bolus injection (10 micrograms/kg) followed by an infusion (1 micrograms.kg-1.min-1 for 60 min) to rats adapted to hypoxia (10% O2) for 4 wk and to air control rats. C-ANP-(4-23) significantly lowered MPAP in hypoxic rats but not in air controls. A statistically insignificant reduction in mean systemic arterial pressure was found in both groups after C-ANP-(4-23) administration. C-ANP-(4-23) significantly (two- to threefold) increased endogenous plasma ANP levels in both groups; the increase was not significantly different between groups. Both basal and post-C-ANP-(4-23) levels of plasma ANP were greater in hypoxia-adapted animals than in air controls; the C-ANP-induced increase in plasma ANP was not significantly different between groups. These results suggest that the endogenous ANP may modulate pulmonary vascular tone in rats with hypoxic pulmonary hypertension.

Animals↗
PubMed1990

Atrial natriuretic peptide attenuates the development of pulmonary hypertension in rats adapted to chronic hypoxia.

To test the hypothesis that chronic infusion of atrial natriuretic peptide (ANP) instituted before hypoxic exposure attenuates the development of pulmonary hypertension in hypoxia adapted rats, ANP (0.2 and 1.0 microgram/h) or vehicle was administered intravenously via osmotic minipump for 4 wk beginning before exposure to 10% O2 or to room air. Low dose ANP increased plasma ANP levels by only 60% of vehicle controls after 4 wk and significantly decreased mean pulmonary arterial pressure (MPAP) (P less than 0.01), the ratio of right ventricular weight to body weight (RV/BW) (P less than 0.01), and the wall thickness of small (50-100 microns) pulmonary arteries (P = 0.01) in hypoxia-adapted rats. ANP did not alter any of these parameters in air-control rats. High dose ANP increased plasma ANP levels by 230% of control and produced greater reductions in MPAP (P less than 0.001) and RV/BW) (P less than 0.05), but not in pulmonary arterial wall thickness, than the low dose. Neither dose of ANP altered mean systemic arterial pressure in either hypoxic or normoxic rats. The data demonstrate that chronic infusion of exogenous ANP at a dose that does not affect MPAP or RV weight in air-control rats attenuates the development of pulmonary hypertension and RV enlargement in rats adapted to chronic hypoxia.

Acclimatization↗
PubMed1990

Relation between plasma atrial natriuretic peptide (ANP) and glomerular ANP receptors in 5/6 nephrectomized rats.

Chronic renal failure (CRF) was induced in male wistar rats (Group I) by 5/6 nephrectomy and the sham-operated ones served as control (Group II). The results showed that in Group I, plasma atrial natriuretic peptide (ANP) levels increased progressively as the Scr was elevated. Plasma R-A rose simultaneously compared to the normal (P less than 0.001). At the 20th week after operation, urine volume and Na decreased significantly (P less than 0.05). The number of glomerular receptors decreased markedly at the 12th week (P less than 0.05) and 20th week (P less than 0.01). Our data suggest that in 5/6 nephrectomized rats, the elevation of plasma ANP level might be partly caused by the damage of glomerular ANP receptors, and the elevated plasma ANP could not play its role in diuresis, natriuresis, blood pressure depression and R-A inhibition as a result of the damage of kidney ANP receptors.

Animals↗
PubMed1989

Cross-cultural studies of dementia. A comparison of mini-mental state examination performance in Finland and China.

The Mini-Mental State Examination of Folstein et al was translated into and culturally adapted to Chinese and Finnish and used in dementia surveys involving probability samples of 2187 Shanghai elderly, aged 65 to 74 years, and 525 Finns of the same age group. The mean scores of these two groups were statistically different owing to the lower scores of Shanghai subjects who had no formal education. When this subset of 579 subjects was eliminated from the analysis, the distribution of total scores was almost identical in the two populations, suggesting that the Mini-Mental State Examination can be used in disease populations, provided education is taken into account. However, there remained cultural differences in regard to individual test items; the Chinese had better recall but did not do as well as Finnish or US subjects when asked to copy a figure.

Aged↗
PubMed1989

Production of AMP and adenosine in the interstitial fluid compartment of the isolated perfused normoxic guinea pig heart.

The pathway of production of AMP and adenosine in the myocardial interstitial fluid compartment was studied in the isolated perfused normoxic guinea pig heart by collecting the transmyocardial effluent (t.m.e.) with the method of De Deckere and Ten Hoor (1977). Besides adenosine and inosine, AMP was found in t.m.e. Infusion of alpha,beta-methylene adenosine 5'-diphosphate (AOPCP), a specific inhibitor of the ecto 5'-nucleotidase, resulted in increases in t.m.e. AMP and inosine and a decrease in adenosine. Infusion of acetate producing a nearly twofold increase in myocardial AMP content did not increase the t.m.e. AMP even in the presence of AOPCP. In preparations made from 6-OH dopamine treated animals, the t.m.e. adenosine and inosine were reduced and AOPCP produced smaller increases in AMP and inosine, indicating that most if not all of the t.m.e. AMP originated from the sympathetic nerve terminals. Infusions of beta,gamma-imidoadenosine and beta,gamma-methylene adenosine 5'-triphosphate (AMPPNP and AMPPCP), non-hydrolysable analogs of ATP, resulted in dose-dependent increases in the t.m.e. AMP, which were much augmented in the presence of AOPCP. AMPPNP produced similar effects in 6-OH dopamine-treated preparations. As AMPPNP and AMPPCP are good substrates of ATP pyrophosphohydrolase, these findings indicate the presence of ATP pyrophosphohydrolase in the myocardial interstitial space.

5'-Nucleotidase↗
PubMed1989

Cross-cultural studies of dementia: use of a Chinese version of the Blessed-Roth Information-Memory-Concentration test in a Shanghai dementia survey.

A culturally adapted Chinese version of the Blessed-Roth Information-Memory-Concentration test (CIMC) was used in a dementia screening survey of a probability sample of 5,055 elderly Shanghai residents. The individual items on the CIMC that best predicted the overall score were similar to the best predictor of an American version of the IMC. Performance on the CIMC was markedly affected by the level of education or lack thereof. In a subsample for whom clinical diagnoses were obtained, it was possible to establish cutoff values on the CIMC by stratifying the sample according to education.

Aged↗
PubMed1989

Atrial natriuretic factor in NaCl-sensitive and NaCl-resistant spontaneously hypertensive rats.

Our previous studies demonstrated that chronic dietary NaCl supplementation is associated with significant increases in plasma atrial natriuretic factor in Wistar-Kyoto (WKY) rats but not in NaCl-sensitive spontaneously hypertensive rats (SHR-S). The current study tested the hypotheses that 1) acute volume-induced atrial natriuretic factor release is impaired in SHR-S compared with control NaCl-resistant SHR (SHR-R) and WKY rats maintained on basal (1%) NaCl diets; 2) dietary NaCl supplementation (8% NaCl for 2 weeks) alters acute volume-dependent atrial natriuretic factor release in these strains; and 3) replacement of the deficiency in circulating atrial natriuretic factor seen in NaCl-supplemented SHR-S can reverse the NaCl-sensitive component of hypertension. SHR-S and control SHR-R and WKY rats were placed on 1% or 8% NaCl diets at age 7 weeks; 2 weeks later, right atrial pressure and plasma atrial natriuretic factor were measured in conscious rats before and after acute volume expansion (7, 20, and 60 ml/kg, 5% dextrose, for 1 minute). The slopes of the right atrial pressure x plasma atrial natriuretic factor linear regression for the SHR-S fed both 1% and 8% NaCl were significantly shallower (p less than 0.01) than those of 1% NaCl-fed SHR-R or WKY rats. Dietary NaCl supplementation did not alter right atrial pressure in any strain and blunted acute volume-induced atrial natriuretic factor release in WKY rats, but not in SHR-S or SHR-R, suggesting the dietary NaCl-induced elevation in plasma atrial natriuretic factor levels in WKY rats may be related to impaired clearance, as well as enhanced release, of the peptide. The plasma levels of exogenous atrial natriuretic factor required to abolish the NaCl-induced pressor effect in SHR-S were 12-fold greater than endogenous plasma atrial natriuretic factor levels in 8% NaCl-fed WKY rats, suggesting that impairment of atrial natriuretic factor release does not play a major role in the pathogenesis of NaCl-sensitive hypertension in SHR-S.

Animals↗
PubMed1989

[Malignant tumor with peripheral neuropathy as presenting symptom--clinical analysis of 52 cases].

Fifty-two cases of malignant tumors with peripheral neuropathy as presenting symptom are reported. The duration of the peripheral neuropathy varied from 2 to 11 months before the malignant tumors were confirmed. The initial peripheral neuropathy included cranial nerve, sciatic nerve, intercostal nerve, brachial plexus, multiple peripheral nerves, thoracic outlet syndrome, polyneuritis, peripheral neuritis, autonomic nerve and Horner's syndrome. Most of these malignant tumors were lung cancer, nasopharyngeal cancer and hepatic carcinoma in order of incidence. Pathogenesis, clinical features, diagnosis and treatment of these tumors are discussed with review of the literature. The author emphasizes that if there was peripheral neuropathy of unknown cause, examination has to be done in detail and repeatedly for early diagnosis and better result.

Adult↗
PubMed1989

Partial agonist activity of celiprolol as assessed in conscious unrestrained dogs in comparison with those of pindolol and labetalol.

The effects of celiprolol on the heart rate (HR) and the total peripheral resistance (TPR) were studied in chronically instrumented conscious dogs in comparison with those of pindolol, propranolol and labetalol. Intravenous injection of pindolol, celiprolol and labetalol increased the HR and decreased the TPR dose-dependently, whereas propranolol did not. The ratios of doses that elicited 12% changes in both parameters (HR12/TPR12) were 4.85 +/- 2.63, 0.61 +/- 0.03 and 0.42 +/- 0.11 for celiprolol, pindolol and labetalol, respectively, indicating the preferential reduction of TPR by celiprolol. Changes in HR and TPR produced by these three agents were antagonized by propranolol dose-dependently. However, inhibition by 3 mg/kg of propranolol was incomplete in the cases of labetalol-induced decrease in the TPR at the dose of TPR12 (51%) and celiprolol-induced increase in the HR at the dose of HR12 (89%). These results suggest that changes produced by celiprolol as well as pindolol and labetalol were mostly explainable by partial agonist activity via beta-adrenoceptors. However, the contribution of the alpha-blocking activity must also be taken into consideration in the case of the reduction of the TPR by labetalol. In addition, there is a possibility that celiprolol may increase HR via its direct action.

Adrenergic alpha-Agonists↗
PubMed1989

[The effect of vanillin on the fully amygdala-kindled seizures in the rat].

The anticonvulsive action of vanillin, an antiepileptic agent structurally related to vanillyl alcohol isolated from Gastrodia elata Blume, on the fully amygdala-kindled seizures was investigated. Fully kindled seizures were produced by repeated application of low intensity electrical stimulation to the basolateral amygdala once per day. Fifteen consecutive stimulations were needed to reach the first stage 5 seizures at which animals showed behavioral convulsions and electroencephalographic abnormalities. The stage 5 seizures were suppressed by vanillin ip 1 h before stimulation with the ED50 of 286 mg/kg. Meanwhile, the epileptic afterdischarge duration was significantly shortened. Phenytoin at a nontoxic dose 50 mg/kg ip obviously reduced the stage 5 seizures. The present study provides a very useful experimental model of chronic epilepsy to detect anticonvulsants.

Amygdala↗
PubMed1989

[Optimum number of mixed peripheral blood samples by membrane filtration technique for mass blood survey of filariasis].

The membrane filtration technique has been used widely in the evaluation of effect of control and survey of filariasis. The present study was made to explore an optimum number of mixed peripheral blood samples and a mathematical model of work load for this method in surveying filariasis. By analysing the correlation between the microfilaremia rate and the optimum number of mixed peripheral blood samples and applying the theory of Binomial Distribution or Poisson Distribution, the authors reckoned a table for estimating the number of filariasis cases in villages with different microfilarial rates and different population as well as the optimum number of mixed peripheral blood samples.

Animals↗