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Biomedical subjects

L Zhao

Publications and source records attributed to L Zhao.

At least 433 records · Page 24Linked to original sources
PubMed1992

Haemocompatibility of polymer having phospholipid polar groups evaluated by monoclonal antibody method.

The haemocompatibility of a polymer having the phospholipid polar group, poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate(BMA)), was evaluated by a monoclonal antibody SZ-21 (directing specifically against the membrane glycoprotein complex IIIa of human platelet) radioimmunoassay method. The study showed that poly(MPC-co-BMA) possessed better haemocompatibility than segmented polyurethane (SPEU). Radioactivity of platelets adhered (counts per min/cm) on a polyethylene (PE) tube coated with poly(MPC-co-BMA) was 19.51 +/- 5.58, with albumin; 20.05 +/- 7.29, with SPEU having sulphonated group; 76.10 +/- 18.9, with SPEU; 287.0 +/- 95.0, PE treated by plasma irradiation; 2091 +/- 261, and original PE was 1772 +/- 116. The results were further certified by scanning electron microscopic observations.

Antibodies, Monoclonal↗
PubMed1992

Factors related to long-term stay in hospital by elderly people in a Japanese city.

The characteristics and social backgrounds of 61 elderly patients with long hospital stays and those of 179 incapacitated elderly people living at home in a Japanese city were compared. Discriminant function analysis was performed to clarify the factors associated with long-term use of hospital beds by elderly people. In addition to this analysis, the elderly patients with long hospital stays were divided into two subgroups according to the likelihood of discharge, and these subgroups were compared in the same way. The elderly patients with long hospital stays were more likely to be women, persons with low ADL, living alone and not living with a spouse or a second generation, compared with incapacitated elderly people living at home. Analysis of the subgroups of the elderly subjects with long hospital stays showed that use of a urethral catheter and not undergoing rehabilitation were the medical factors related to difficulty of discharge, while being women, of advanced age and not having their own room at home were the non-medical factors associated with long-term occupation of hospital beds.

Activities of Daily Living↗
PubMed1992

Chronic hypoxia impairs soluble guanylyl cyclase-mediated pulmonary arterial relaxation in the rat.

We have examined the effects of exposing rats to hypoxia (10% fractional inspired O2 concentration) for 2 and 7 days on endothelium-dependent and -independent vasodilation and also on the ability of guanosine 3',5'-cyclic monophosphate (cGMP) to activate cGMP-dependent protein kinase (G-kinase) in rat conduit pulmonary arteries (PA). The ability of acetylcholine (ACh) and sodium nitroprusside (SNP) to both relax PA rings and elevate tissue cGMP levels was significantly attenuated in PA from hypoxic animals. The ability of atrial natriuretic peptide to relax and generate cGMP in PA rings was unchanged by hypoxia. Relaxation and elevation of cGMP levels induced by SNP in aortic rings was unaltered by hypoxia. Similarly, hypoxia did not alter the concentration-dependent activation by exogenous cGMP of G-kinase. We conclude that chronic exposure of rats to hypoxia results in a selective impairment of soluble guanylyl cyclase in rat PA, leading to an attenuation of ACh- and SNP-induced cGMP accumulation and relaxation.

Animals↗
PubMed1992

Effects of natriuretic peptides and neutral endopeptidase 24.11 inhibition in isolated perfused rat lung.

We have studied the acute effect of brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) on pulmonary vascular tone in normoxia and acute hypoxia in the absence and presence of a specific inhibitor of neutral endopeptidase 24.11 (NEI, UK 73, 967, candoxatrilat; Pfizer) in the isolated and blood-perfused rat lung preparation. Baseline pulmonary artery pressure (Ppa) was 16.4 +/- 0.3 mm Hg in lungs from normoxic control rats and 22.5 +/- 0.3 mm Hg in lungs from rats kept in hypoxia (FIO2 = 10%) for 7 days. Acute hypoxic pulmonary vasoconstriction (HPV delta Ppa) was similar in normoxic control rats (9.5 +/- 0.6 mm Hg) and chronically hypoxic rats (9.8 +/- 0.9 mm Hg). NEI at 0.07 and 0.2 mg had no effect on baseline Ppa or HPV delta Ppa. Synthetic BNP at 10 nM had no effect on baseline Ppa but produced a 2.8 +/- 0.2 mm Hg reduction in HPV delta Ppa alone and 2.7 +/- 0.2 mm Hg reduction in the presence of 0.07 mg NEI in normoxic control rats. In contrast, ANP at 10 nM produced a significantly greater decrease in HPV delta Ppa in the presence of 0.07 mg NEI (4.8 +/- 0.3 mm Hg, p < 0.05) compared with ANP alone (2.9 +/- 0.4 mm Hg), and similar results were also observed in chronically hypoxic rats. Thus, BNP has a vasodilator effect similar to that of ANP in the pulmonary circulation. Inhibition of neutral endopeptidase 24.11 augments the effects of ANP on HPV but does not influence the pulmonary vascular responses to BNP.

Animals↗
PubMed1992

[Factors influencing prolonged hospital stays by elderly patients: problems in medical management including use of urethral catheters].

Fifty-nine elderly patients who had been hospitalized more than six months in five hospitals in the city of Mino in Osaka Prefecture, were studied to clarify the factors influencing prolonged hospital stays by the elderly. Their mean age was 82.2 years, and women accounted for 86% of the patients. One-third had suffered a stroke. As for ADL, 44% were completely dependent when walking, eating, bathing and dressing. Moreover, 36% had severe dementia, 19% suffered from decubitus ulcers, 66% were undergoing rehabilitation, 58% were receiving venous infusion therapy, 36% used a urethral catheter, and 10% were receiving tube feeding. The subjects were divided into two groups according to the likelihood of discharge assessed by the doctors in charge: one group consisted of 27 patients who might be discharged and the other of 32 patients with an ongoing need for inpatient care. Multivariate analyses using Hayashi's quantification method II indicated that use of a urethral catheter and not undergoing rehabilitation were the main factors associated with the need for inpatient care, while being a woman, being of advanced age and not having one's own room at home were the non-medical factors which made it difficult for the patients to be discharged from the hospital. As use of a urethral catheter was the factor most strongly related to prolonged hospital stay, multivariate analyses were applied to the 45 patients with urinary incontinence, who were divided into one group of 21 patients with, and one of 24 without a urethral catheter. The factors associated with use of a urethral catheter were then investigated.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[The toxicity of herbicide Asulam].

We conducted a series of toxicity tests and short-term mutagenic assays of Asulam and 40% (W/V) sodium Asulam. It was found that the LD50 of Asulam with acute oral toxicity was 30000 mg/kg for mice, and the LD50 of sodium Asulam for mice and rats were equal (8250 mg/kg). The cumulative coefficient of sodium Asulam in Wistar rats was 9.42. None died from sodium Asulam absorbed via skin. Negative results were obtained in Ames test, Bacillus subtilis repair test and the micronucleus test. There was no significant difference between the control group and the treated groups in the chromosomal aberration rates of spermatogonia and primary spermatocytes of mice testis. The results indicated that Asulam should be regarded as a substance of low toxicity and low accumulation. No mutagenicity was observed in our experiment.

Animals↗
PubMed1992

[A new virus of rabbit. III. Study on morphological superstructure and antigenicity of rabbit hemorrhagic disease virus (RHDV)].

In the spring 1986, an acute infectious disease occurred in Wuhan Second Producing Medical Manufactory, and the rabbit almost died. We tested the mortal symptom and confirmed rabbit Hemorrhagic Disease (RHD) as same as Huang Yinyao report. Hubei Traditional Chinese Medicine Institute appear this RHD also. After we purified virus of above two source by low speed, high speed and sucrose density gradient centrifugation, they can react with antiserum of RHDV from Nanjing Agricultural University in agar gel immunodiffusion tests. These results proved that they belong to the same serotype. Data indicate RHDV have difference morphological superstructure, viral polypeptides and especially RHDV can't react with antiserum of standard Parvovirus of rabbit and so on, so we suggest RHDV is a new virus.

Animals↗
PubMed1992

[A new virus of rabbit. II. Study on morphological structure and some physicochemical properties of a strain of rabbit hemorrhagic disease virus].

In this paper a strain of Rabbit Hemorrhagic Disease Virus (RHDV) was isolated and purified from the diseased rabbit livers with a method of using chloroform, two-phase of polyethylene-glycol-dextran sulfate sodium and sucrose density gradient centrifugation. Purified virus was nonenveloped, icosahedeal symmetry with a triangulation number of 3, and 33-37 nm in diameter. The capsid was composed of 32 capsomeres with central holes in an outer diameter of about 9nm. Two types of viral particles having different sedimentation coefficient, 130s and 166s could be identified after sucrose density gradient centrifugation. Probably no less than four virion proteins with molecular weight of 66.4, 65.0, 63.5, 41.0 x 10(3) dalton were detected by SDS-polyacrylamide gel electrophoresis. Viral nucleic acid was extracted from purified virus by using SDS-proteinase K-phenol. Tests with diphenylamine, formaldehyde, and staining with acridine orange as well as the curves of thermal denaturation showed that this kind of virus had a single-stranded DNA. The molecular weight of the ssDNA was approx 2.1 x 10(6) dalton as determined by electron microscopy. Data indicate that the RHDV may like the parvovirus of the family Parvoviridae.

Animals↗
PubMed1992

[A comparative study of the characteristics and social backgrounds of frail and elderly persons at home, long-stay elderly hospital patients, and residents of welfare homes for the frail elderly].

Three studies were carried out in Mino City, Osaka Prefecture, on 188 frail and elderly persons living at home (the home group), 61 elderly patients who had been hospitalized more than six months (the inpatient group), and 72 residents of welfare homes for the frail elderly (the resident group). The characteristics and social backgrounds of the three groups were compared. About 30% of each group had suffered a stroke. As for ADL score, moderate disability was dominant in the home group, severe disability in the inpatient group, and slight disability in the resident group. The proportions of those who had been living alone and those who had no spouse were significantly higher in the inpatient group and in the resident group than in the home group. Significantly fewer subjects in the resident group had been living with their offspring than in the home group or in the inpatient group. The percentage of those who did not have their own home was the highest for the resident group. Multivariate analyses using Hayashi's quantification method II were conducted for a comparison between cases belonging to the home group and the inpatient group, and between the home group and the resident group. The analysis of the home group and the inpatient group revealed a relationship of the inpatient group to severe disability in ADL, and living alone. Differences between these two groups were related to such variables as ADL, sex, living or not living alone, living or not living with offspring, and having or not having a spouse.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Effects of continuous infusion of atrial natriuretic peptide on the pulmonary hypertension induced by chronic hypoxia in rats.

1. The effects of the continuous infusion of atrial natriuretic peptide on the development of pulmonary hypertension were studied in rats exposed to chronic hypoxia. 2. Continuous intravenous infusion of two doses of synthetic rat atrial natriuretic peptide, 300 ng/h per rat (0.10 pmol/h per rat) and 800 ng/h per rat (0.28 pmol/h per rat), attenuated the development of pulmonary hypertension in rats exposed to chronic hypoxia (fractional concentration of oxygen in inspired air = 10%) for 7 days: (i) the pulmonary artery pressure (mean +/- SD) in the vehicle-treated hypoxic group was 45 +/- 6 mmHg compared with 28 +/- 6 mmHg in the vehicle-treated normotoxic group (n = 8, P less than 0.001); (ii) treatment with atrial natriuretic peptide in normoxia did not alter the pulmonary artery pressure, systemic blood pressure or heart rate; (iii) treatment with atrial natriuretic peptide in hypoxia resulted in a lower pulmonary artery pressure in the group treated with 800 ng of atrial natriuretic peptide/h per rat (38 +/- 8 mmHg, P less than 0.05 compared with the vehicle-treated hypoxic group) without affecting the systemic blood pressure or heart rate. 3. Chronic hypoxia resulted in an extension of vascular smooth muscle towards the periphery of the lung with the development of muscle in normally non-muscularized vessels (remodelling).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Two New Oleanane Saponins from Anemone flaccida.

Two new oleanane saponins, named flaccidoside II and III, were isolated from the rhizome of ANEMONE FLACCIDA Fr. Schmidt. On the basis of spectroscopic analysis and chemical transformation their structures were elucidated as 3- O-[alpha- L-rhamnopyranosyl-(1-->2)-beta- D-xylopyranosyl]-oleanolic acid 28- O-[alpha- L-rhamnopyranosyl-(1-->4)-beta- D-glucopyranosyl-(1-->6)-beta- D-glucopyranoside] and 3- O-[beta- D-glucopyranosyl-(1-->2)-beta- D-xylopyranosyl]-oleanolic acid 28- O-[alpha- L-rhamnopyranosyl-(1-->4)-beta- D-glucopyranosyl-(1-->6)-beta- D-glucopyranoside].

Journal Article↗
PubMed1991

Neutral endopeptidase 24.11 inhibition reduces pulmonary vascular remodeling in rats exposed to chronic hypoxia.

Inhibition of the metabolism of endogenous atrial natriuretic peptide (ANP), by continuous infusion of a specific inhibitor of neutral endopeptidase (membrane metalloendopeptidase E.C. 3.4.24.11), UK 73,967 (candoxatrilat), was undertaken in rats, in which chronic hypoxia was used as a stimulus to induce pulmonary hypertension and right ventricular hypertrophy. Inhibition of neutral endopeptidase 24.11 with low-dose and high-dose UK 73,967 (NEI) increased endogenous plasma ANP by greater than 155% during the development of pulmonary hypertension. NEI treatment reduced mean pulmonary arterial pressure in hypoxia as follows: vehicle 26.6 +/- 4.0 mm Hg; low-dose NEI 22.7 +/- 1.9 mm Hg, and high-dose NEI 22.6 +/- 2.5 mm Hg (both p less than 0.01 compared with hypoxic vehicle); however, it was without effect on pulmonary arterial pressure in normoxia (17.6 +/- 2.2 mm Hg) or on systemic blood pressure. The development of right ventricular hypertrophy was also reduced in both groups treated with NEI (right ventricular weight/left ventricular weight: 0.43 +/- 0.03 vehicle; 0.40 +/- 0.02 low-dose NEI and 0.40 +/- 0.02 high-dose NEI, both p less than 0.05 compared with vehicle). Remodelling of the pulmonary vasculature, characterized by extension of the muscle within the small pulmonary arteries toward the periphery of the lung, was reduced by NEI treatment (percentage of thick-walled peripheral vessels; 19.2 +/- 3.1% vehicle; 10.4 +/- 2.3% low-dose NEI and 8.1 +/- 1.8% high-dose NEI, both p less than 0.001 compared with vehicle). In the isolated blood perfused rat lung pulsed doses of NEI had no effect on pulmonary vascular tone in the absence of ANP. Specific inhibition of the enzyme neutral endopeptidase reduces vascular remodelling, the development of pulmonary hypertension, and right ventricular hypertrophy. Endogenous ANP modulates vascular remodelling in vivo. Retarding the metabolism of endogenous ANP through inhibition of neutral endopeptidase 24.11 represents a potential approach toward therapy. g

Animals↗
PubMed1991

Anterior tarsal tunnel syndrome.

We have reviewed 10 patients treated for anterior tarsal tunnel syndrome produced by compression of the deep peroneal nerve or its branches, and we have studied the anatomy of the tunnel in 25 adult feet. The causes of onset of the syndrome included contusion of the dorsum of the foot, tight shoe laces, talonavicular osteophytosis, ganglion, and pes cavus. The clinical signs were often diagnostic but electromyography was helpful. Operative decompression in nine feet of eight patients gave successful results at 1.5 to 4 years follow-up.

Adolescent↗
PubMed1991

[Plasma PGI2 and TXA2 levels on a model of PDH in leptospirosis].

Guinea pigs were intravenously injected with icterhemorrhagiae serogroup Lai serovar strain 017 leptospirosis to model the pulmonary diffuse hemorrhage (PDH) in leptospirosis. Thirty-eight hours after the injection, the jugular arteries were catheterized to collect blood sample. The plasma was prepared for radioimmunoassay of TXB2 and 6-keto-PGF1a, the stable metabolites of TXA2 and PGI2 respectively. The plasma level of TXB2 in the experimental group, 107.15 +/- 41.65 pg/ml (n = 7), almost doubled that of the control, 54.05 +/- 12.93 pg/ml (n = 7), with significant difference (P less than 0.01); meanwhile, no significant difference was observed of 6-keto-PGF1a, 67.97 +/- 16.89 pg/ml (n = 6) vs. 98.06 +/- 40.63 pg/ml (n = 9) with P greater than 0.1. The fact that TXA2 causes vasoconstriction and increases vessel permeability suggests that TXA2 elevation should play a role in the mechanism of PDH in leptospirosis.

6-Ketoprostaglandin F1 alpha↗