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Biomedical subjects

B Zhou

Publications and source records attributed to B Zhou.

At least 163 records · Page 9Linked to original sources
PubMed1996

[The incidence of hypertension and associated factors in 10 population groups of China].

OBJECTIVE: To study the natural populations studied including 3 groups of workers, 6 groups of farmers and 1 group of fishermen, distributed in Heilongjiang, Hebei, Shanxi, Shannxi, Jiangsu and Zhejiang provinces and Guangxi Autonomous Region. METHODS: In 1982-1985, a total of 25656 persons (male 13,390, female 12,266) aged 35-59 were surveyed for the risk factors of cardiovascular diseases. RESULTS: 20641 (male 10584, female 10057) of them were re-examined in 1988-1989, giving a response rate of 80.5%. During the 5 year follow-up period, the incidence of definite hypertension was 1.20% (male) and 1.07% (female), with the borderline plus definite rates being 3.27% and 2.68% per year, respectively. The incidence varied from 0.76% to 5.62% per year for borderline plus definite. The incidence was higher in the north than in the south, higher in farmers than in workers, and lowest in fishermen. The incidence rates were higher in men than in women, and the older the age, the higher the incidence of hypertension. Both univariate and logistic regression indicated that the main risk factors of hypertension are the levels of baseline systolic and diastolic blood pressure, BMI, and alcohol intake, all of which showed a dose-response relation to the incidence rate of hypertension. These relationships were affected by age; the younger, the more marked the increase of relative risk (RR) with risk factor levels. After adjusting for age, sex and location by logistic regression, with every 10 mmHg increase of SBP or DBP within the normotensive range, or every 1 unit increase of BMI, the RR of hypertension was -- estimated to increase by 71.5%, 102.4% and 10.8%, respectively. No significant relationship was found between the level of serum cholesterol and the incidence of hypertension, but persons with faster heart rates showed a higher RR. CONCLUSION: Primary prevention of hypertension in persons should be started before age of 35 years.

Adult↗
PubMed1996

[Effects of endoscopic sinus surgery and relative factors].

The results of 296 endoscopic sinus surgery (ESS) from Oct. 1991 to May, 1993 were analysed. Pre- and post-operative examinations in this series were as follows: 1. Peripheral blood T lymphocyte subclusters test (100 cases): 2. Immunohistochemical test of nasal polyp (103 cases): 3. Pathologic examination of nasal polyp: 4. CT scan typing (103 cases). Men and women ratio was 2:1 and their ages varied from 7 to 72 years. 107 patients were given general anesthesia and 189 patients local anesthesia. The clinical stages of chronic sinusitis were divided as: 53.7% (N), 29.3% (II), 10.9% (III) and 6.1% (I). The clinical curative rate was 85.7% (126/147 cases), and improving rate was 99.3%. The standard of clinical stage of chronic sinusitis, the relative factors of prognosis with the results of ESS, pathological test, immunohistochemical test and follow-up after ESS were discussed.

CD4-CD8 Ratio↗
PubMed1996

[Effect of recombinant human epidermal growth factor on the expansion of human skin in vitro].

We investigated the effect of the different concentrations of recombinant human epidermal growth factor (rhEGF) on the expansion of human skin in vitro. Pieces of skin about 2 mm2 in area were placed in 24-cell wells and rhEGF in different concentrations was added. The wells were incubated at 37 degrees C in 5% CO2 for 4 d. The expanded area of each piece of skin was measured. The results indicated that rhEGF possessed a regulating effect on the expansion of skin pieces, and the expanded area was parabolically related with the concentrations of rhEGF. When the rhEGF concentration reached 5 micrograms/L, the maximal area expansion (7.08 +/- 2.40 mm2) was found, which was as twice as the area in control group (3.63 +/- 1.98 mm2). It was suggested that rhEGF had a potential therapeutic effect in wound healing.

Cell Division↗
PubMed1996

[Mechanism of inhibitory action of sodium ferulate on liver lipid peroxidation in mice].

The study has shown that sodium ferulate (SF) significantly inhibits the rise of liver lipid peroxides MDA content, alleviates the depletion of hepatic GSH pond, and reverses the decline of GST, GSH-Px levels in ethanol treated mice. The results indicate this inhibitory action of SF is related to diminishing the generation of oxygen free radicals by stabilizing GSH and related enzyme levels.

Animals↗
PubMed1996

[Treatment outcome of 1,000 cases of endoscopic sinus surgery].

To assess the treatment outcome of endoscopic sinus surgery (ESS), 1,000 patients with chronic sinusitis and nasal polyp treated between November 1991 and January 1995 were included in this study. Among them, 754 patients (64.8%) had previous operations from 1 to 25 times with an average of 3.7. Before ESS, axial and coronal CT scans were obtained (window width: 1,000 HU, window level: +90 HU; section thickness: 2 mm with 12 to 16 sections). Patients with clinical stages from I to IV were 9.9%, 21.0%, 15.0% and 54.1% respectively. Bilateral ESS was performed in 95% patients, septoplasty in 27.6%, middle meatal antrostomy in 78.5%. The clinical cure rate was 84.0%, 557 patients were considered as primary healing, 283 patients delayed healing and 160 patients had persistent inflammation. Complications were noted in 18 patients. Bleeding during ESS varied from 10 to 1,800 ml (average 180 ml). The indications, preoperative evaluation, control of bleeding, prevention of complications and prognosis were discussed in detail. The article indicated that the important factors to increase the cure rate are postoperative follow-up and systematic treatment.

Adolescent↗
PubMed1995

Comparative studies of the conformation of the N-terminal fragments of staphylococcal nuclease R in solution.

In order to elucidate the folding of nascent peptide, five peptide fragments of staphylococcal nuclease R starting from N-terminal end and of different chain lengths are made by deletion of 47, 39, 28, 14 and 8 amino-acid residues from its C-terminal end, respectively. Changes in conformation of the N-terminal fragments have been compared by using Fourier-transform infrared spectra, far-ultraviolet circular dichroism spectra and analysis of surface hydrophobicity. The experiments indicate that all the five fragments have certain amounts of residual structure; in general, with increasing the peptide chain, the contents of secondary structure and the enzyme's activity of the peptide increase, and the exposed hydrophobic side chains brought about by the deletion of C-terminal residues are gradually buried in the interior of the nuclease. However, the ordered secondary structures do not always increase with increasing the peptide chain. Further growth of the length of the peptide chain could have an important effect on the conformation of the peptide fragment already synthesized, suggesting some structural adjustments should be necessary in order for the newly synthesized polypeptide to attain its final native conformation. These results support Tsou's nascent peptide folding hypothesis (Tsou, C.-L. (1988) Biochemistry 27, 1809-1812).

Circular Dichroism↗
PubMed1995

Medicagenic acid saponins from Aster batangensis.

Two new medicagenic acid saponins, named asterbatanoside J and K, were isolated from the roots of Aster batangensis. On the basis of chemical and spectral studies especially 2D NMR including COSY, HETCOR, HMQC, HOHAHA, TOCSY, ROESY and HMBC techniques, their structures were established as 3-O-beta-D-glucopyranosyl-(1--> 6)-beta-D-glucopyranosyl-2 beta, 3 beta-dihydroxy-olean-12-en-23 alpha, 28-dioic acid- 28-O-alpha-L-arabinopyranosyl-(1-->3)-alpha-L- rhamnopyranosyl-(1-->2)-beta-D-fucopyranoside and 3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl- medicagenic acid-28-O-beta-D-xylopyranosyl-(-->4)-[alpha-L- arabinopyranosyl-(1 -->3)-alpha-L-rhamnopyranosyl-(1-->2) -beta-D-fucopyranside, respectively.

Carbohydrate Conformation↗
PubMed1995

The relationship between dietary factors and serum lipids in Chinese urban and rural populations of Beijing and Guangzhou. PRC-USA Cardiovascular and Cardiopulmonary Research Group.

BACKGROUND: Serum cholesterol (TC) levels and coronary heart disease (CHD) are lower in China than in western countries. This report examines the role of diet in determining TC. METHODS: Data were collected as part of a cross-sectional study of 10,000 men and women, 35-54 years old, conducted in 1983-1984 in four areas in China. A 10% subsample was surveyed for eating patterns and measurement of blood lipids. Six one-day dietary recalls were collected on each participant. RESULTS: Mean daily intake of energy from fat was less than 30%. Mean Keys scores ranged from 20.4 to 32.6. In multivariable regression analysis controlling for age, body mass index (BMI), and alcohol, Keys score was statistically associated with serum TC. A 10-unit greater Keys score was associated with 6.3 mg/dl higher TC and 4.0 mg/dl higher low density lipoprotein cholesterol. CONCLUSIONS: We conclude that in China the relation of dietary factors to serum lipids is similar to that in populations having high serum TC levels.

Adult↗
PubMed1995

Human chorionic gonadotropin (hCG) fails to stimulate gonocyte differentiation in newborn mouse testes in organ culture.

The primitive germ cells within the postnatal testis differentiate through several steps to form primary spermatocytes, which are required for postpubertal spermatogenesis. It is postulated that this germ cell development is controlled by the hypothalamic-pituitary-gonadal axis. To study the effect of human chorionic gonadotropin (hCG) on postnatal testicular germ cell differentiation, especially on gonocytes, newborn mouse testes (n = 75) were cultured for 7 days in vitro. The synthetic serum-free medium contained either hCG or exogenous human recombinant müllerian inhibiting substance (MIS) plus transferrin, insulin and retinoic acid (TIRA). Fetal calf serum 10% (FCS) was used for control medium. Thirty-eight newborn mouse testes were cultured with hCG (0.1 to 2.0 IU/ml). The percentages of differentiated type-A spermatogonia were not significantly increased compared with synthetic medium alone (NS, p > 0.05), but were only 5 to 7% (p < 0.001) of that of serum-containing medium. By contrast, normal transformation from gonocytes to type-A spermatogonia occurred in newborn mouse testes (n = 10) cultured with serum-free medium containing exogenous MIS. The percentage of differentiated type-A spermatogonia was approximately 77% (NS, p > 0.05) of those seen in serum-containing medium. These findings demonstrate that the transformation of gonocytes to type-A spermatogonia is regulated by MIS, rather than hCG. As early germ cell transformation is deficient in boys with cryptorchidism, the role of hCG in the treatment of infertility associated with undescended testes should be reevaluated.

Animals↗
PubMed1995

Auditory filter shapes at high frequencies.

The shape of the auditory filter was estimated at center frequencies of 4, 12, 14, and 16 kHz for normally hearing subjects, using the notched-noise method. A specially designed sound delivery system was used to generate a high-frequency masking noise with a flat spectrum. For all test frequencies, the auditory filter shapes were estimated at a noise spectrum level (N0) of 40 dB. The mean equivalent rectangular bandwidths (ERBs) of the auditory filter at 4, 12, and 14 kHz were close to the extrapolated values given by Glasberg and Moore [Hear. Res. 47, 103-108 (1990)]. At 16 kHz, the mean ERB was close to the extrapolated value given by Moore and Glasberg [J. Acoust. Soc. Am. 74, 750-753 (1983)]. At 12 and 14 kHz, the auditory filter shapes were also estimated at a noise spectrum level of 50 dB. The mean ERBs of the auditory filter were wider for the higher spectrum level, consistent with previous results obtained at lower center frequencies.

Adult↗
PubMed1995

Reliability of pure-tone thresholds at high frequencies.

Standing waves, in the ear canal are created by the interference of two plane waves of the same frequency traveling in opposite directions. One manifestation of this phenomena is that any lateral motion of the transducer produces a change in the length of the canal and therefore, in general, a change in the sound level at the eardrum. Because of the smaller wavelength at the higher frequencies, the changes produced by movement of the transducer will be larger for the higher frequencies than for the lower frequencies. Thus, when the transducer is removed and replaced between successive threshold estimates, it is expected, from physical principles alone, that the intrasubject reliability of the estimates should be better at the lower frequencies. Previous studies, however, have shown that the intrasubject reliability of threshold estimates is nearly the same at both the low (0-8 kHz) and the high (8-16 kHz) frequency regions. A possible explanation for these anomalous results is proposed. While it is found that transducer placement increases the variability of threshold estimates more at the higher frequencies, it has also been found that conventional headphones reduce the size of the standing wave ratios compared with a hard wall termination. An additional factor is the steeper slope of the psychometric function at the higher frequencies. The combination of these factors produces a standard deviation for threshold estimates that is only about 1 dB larger at the high than at the low frequency region.

Adult↗
PubMed1995

alpha-Ketoacids scavenge H2O2 in vitro and in vivo and reduce menadione-induced DNA injury and cytotoxicity.

We demonstrate that alpha-ketoacids reduce and, in some instances, abrogate menadione-induced DNA damage and cytotoxicity in the human breast cancer cell line, MCF7. We confirm that alpha-ketoacids quench the copious amounts of H2O2 generated by menadione while these alpha-ketoacids undergo nonenzymatic oxidative decarboxylation; our data thus support enhanced H2O2 production as an important pathway for menadione-induced DNA damage and cytotoxicity. We also demonstrate that alpha-ketoacids scavenge H2O2 generated by mitochondria and microsomes when these organelles are exposed to menadione; additionally, alpha-ketoacids protect oxidant-vulnerable enzymes against functional impairment induced by H2O2. Finally, we provide the first in vivo demonstration that acute elevations in concentrations of alpha-ketoacids in rat tissues and urine scavenge H2O2. We conclude that enhanced H2O2 production is a major pathway for menadione-induced DNA damage and cytotoxicity and that the diverse alpha-ketoacids present within the cell must be considered, along with glutathione peroxidase and catalase, as part of the intracellular antioxidant defense mechanisms that regulate the ambient levels of H2O2.

Animals↗
PubMed1995

[Surgical treatment of benign stenosis of the esophagus].

From Nov. 1972 to 1983 Oct., 88 patients with benign stenosis of the esophagus were operated on. The youngest patients was 18 months, and the oldest 63 years. From corrosive injury of esophagus to operation, the shortest period was 13 days and longest 10 years (mean 120 days). In 85 patients, transverse colon was used to replace the esophagus substernally. In 2 patients, reconstruction was done by gastric tube. One patient used transverse colon and part of descending colon. Preoperative gastrostomy was made in 5 patients. There was no operative mortality. One patient developed anastomotic stenosis postoperatively. He refused reoperation and died. The remaining patients survived with a normal life. For the reconstruction of esophagus, problems such as choice of grafts, time of operation, resection of scar or not, and place of anastomosis were discussed.

Adolescent↗
PubMed1995

[Clinicopathologic analysis of ependymoma in childhood].

A review of the clinicopathologic features of 23 ependymomas in children was made, of which 17 were male and 6 female, the male:female ratio being 2.8:1. Their average age was 8.8 years. Seven of the 23 ependymomas were supratentorial, 16 were infratentorial. The mean duration of symptoms prior to operation in the two groups was 5.3 and 3 months respectively. Histologically, the tumor could be classified into three types: papillary (or myxopapillary), epithelial and cellular. According to the degree of differentiation, the tumor could be divided into typical ependymoma and anaplastic ependymoma. Immunohistochemically, 17 of the 23 cases were positive for glial fiber acid protein (GFAP) and the remaining 6 cases were negative. The clinicopathologic features of childhood ependymomas, factors influencing prognosis and histologic classification are discussed.

Adolescent↗