Biomedical subjects

G Zhou

Publications and source records attributed to G Zhou.

At least 109 records · Page 6Linked to original sources

PubMed2000

[Dynamic changes of respiration pathway and active oxygen levels in subcultured tobacco callus].

During the growth and senescence of tobacco callus, the total respiration rate showed two peaks on the 11th and 19th day, respectively. The development and operation of alternative pathway increased gradually, reached the maximum between two respiration peaks, and then declined in the following days, but the cytochrome pathway was still as a main electron transport pathway consistently. Analysis on the levels of active oxygen species during the growth and senescence process in tobacco callus suggested that H2O2 and O2.- were involved in some way in the induction of the development and operation of the alternative pathway, but the increase of production rate of OH might suppress both the development and operation of the alternative pathway, which were enhanced by H2O2 and O2.- respectively. These results were further proved by the use of active oxygen scavengers. The possible participation of the alternative pathway enhanced by active oxygen in the initial senescence process was discussed.

Cells, Cultured↗

PubMed2000

[Effect of combined treatment of 60Co gamma-ray and EMS on antioxidase activity and ODAP content in Lathyrus sativus].

Lathyrus sativus seeds were treated with 60Co gamma-ray and EMS(ethyl methane sulfonate), and their emergence rate and SOD, POD and CAT activities were determined. The result indicated that the treatment decreased the emergence rate. The activities of SOD and POD were changed in accordance with the increase of irradiation dose and EMS concentration, while that of CAT had no obvious change. After treatment, the ODAP content in Lathyrus sativus decreased. Amutant was developed, with toxin content of 0.1%, compared to 0.2% in control.

Amino Acids, Diamino↗

PubMed2000

[Acoustic densitometry for quantification of renal allografts microcirculation and microstructure].

OBJECTIVE: To establish a new method for observing renal allografts microcirculation and microstructure with acoustic densitometry (integrated backscatter, contrast, second harmonics). METHODS: 27 patients with renal allografts were investigated by Doppler, IBS, contrast and second harmonics. Renal allografts failed age in 5 patients 20-61 years. Intravenous injection of SHU-508A was given, compared with pre-injection by quantitative assessment of acoustic densitometry (AD) of renal microstructure. RESULTS: There was a significant difference in the peak intensity, the area under the curve and the half-time of wash-out between pre-injection and injection contrast agent. The wish-in and wish-out curve was shown in a peak shape. The renal allografts with acute rejection were significantly lower than the control group in AD (P < 0.05). No contrast opacification of renal microstructure was present in 5 failed renal allografts and the wish-in and wish-out curve appeared in a straight line shape. CONCLUSION: AD is safe, and efficient in assessing renal allografts microstructure. It more sensitive in detecting allograft complication such as rejection than Doppler.

Adult↗

PubMed2000

[A descriptive epidemiological investigation of anophthalmos and microphthalmos in China during 1988 - 1992].

OBJECTIVE: To investigate the descriptive epidemiological characteristics of cases with anophthalmos and microphthalmos in China. METHOD: According to the hospital-bases monitoring method, the birth defects monitoring program was undertaken in 443 - 588 hospitals from 30 provinces, cities and autonomous regions in China. Data of the new born babies including intra-uterine death and stillbirth from 28 weeks of gestation to a period of 7 days after birth were collected between 1988 and 1992. RESULTS: There were 3,246,408 babies monitored, among which 382 cases of anophthalmos and microphthalmos were found. The average prevalence rate was 1.18/10,000 in China. The decreasing tendency of prevalence rate was shown during the period (chi(2) = 7.381, P < 0.01). The average prevalence rate in the rural area was significantly higher than that in the urban area, and the female cases were higher than that of male cases. The prevalence rates among various regions varied from 0.21 to 2.29/10,000 with the highest in Gansu province and lowest in Tianjin city. 87.7% of the cases with anophthalmos and microphthalmos were associated with other congenital malformations (multiple malformations). The associated malformations were mostly facial (including ear, neck, etc.) followed by skeletomuscular system and central nervous system. 8.1% of cases were diagnosed as syndromes, among which trisomy 21 was the most common condition. CONCLUSIONS: There were large variations in the prevalence rates of anophthalmos and microphthalmos in different parts in China. Careful analysis, particularly the chromosome analysis, should be performed to correctly diagnose the cases, especially for those with multiple malformations.

Abnormalities, Multiple↗

PubMed2000

[Subcutaneous panniculitis-like T-cell lymphoma: expression of cytotoxic-granule-associated protein TIA-1 and its relation with Epstein-Barr virus infection].

OBJECTIVE: To study the clinicopathologic features, the expression of cytotoxic-granule-associated protein TIA-1 and Epstein-Barr virus (EBV) infection in subcutaneous panniculitis-like T-cell lymphoma (SPTCL). METHODS: Totally 17 cases of SPTCL were studied. Immunohistochemical staining was done for TIA-1, CD45RO, CD3, CD20 and CD68, and in situ hybridization for EBV encoded small nuclear RNA (EBER1/2). RESULTS: In the 17 cases of SPTCL, the ratio of male-to-female was 1:1.1 and the median age was 24 years old. The main clinical manifestations were asymptomatic plaques, nodules and masses. Histologically, the pattern of lymphoid cells infiltration was panniculitis. The infiltrated lymphoid cells were pleomorphic and their mitotic figures were few (0 - 2/hpt). In the tumor tissue, there might be epithilioid granulomas, multinuclear cells, beanbag cells, small pieces of necrosis and small vessels with lymphoid cells infiltration in the vascular wall. Immunohistochemically, all the cases showed a T-cell phenotype and the expression rate of TIA-1 was 100% (16/16). By in situ hybridization, the positive rate of EBV-EBER1/2 was 29.4% (5/17). CONCLUSIONS: SPTCL has a specific histopathologic picture. It may originate from cytotoxic T lymphocytes or NK cells. Some of them may be accompanying with EBV latent infection.

Adolescent↗

PubMed2000

[A report of 115 cases of amputation after electric injury].

OBJECTIVE: To analyze the main features of amputation subsequent to electric injury. METHODS: One hundred and fifteen cases of amputation were analyzed with the purpose to define the indication, the optimal level, operational methods and the prognosis. RESULTS: The incidences of amputation in this group were 45.4% for upper and 14.9% for lower extremities, respectively. The indications were total necrosis of the extremities, secondary necrosis of the extremities due to the thrombosis, bleeding and rupture of the major supplying arteries and failure to restore severely injured tissue. The commonest amputation levels were the mid third and the upper third of the forearms. The primary healing rate was 63.5%. CONCLUSION: It was very important to identify the optimal indications, the proper levels and operational methods for the amputation after electric injury, so as to make stumps more suitable for the installation of artificial limbs to restore better function.

Amputation, Surgical↗

PubMed2000

[Analysis on 2158 neural tube defects diagnosed prenatally by ultrasound examination].

A retrospective survey was made to study the prenatal diagnosis on neural tube defects(NTD) by ultrasound examination from 1990 to 1993 in China. A total of 2158 livebirths and stillbirths affected by NTD with 28 weeks or more of gestation were investigated in 233 hospitals of 28 provinces, municipalities and autonomous regions all over the country. The results showed that 61.8% of the NTD were diagnosed prenatally, and 56.5% of the NTD were diagnosed by ultrasound examination. The ratios of anencephaly, myelocele and meningocele diagnosed prenatally by ultrasound examination were 66.7%, 62.5% and 52.5% respectively. Thoracic(46.4%) and lumbar (43.4%) spina bifida were diagnosed more frequently than cervical(35.5%) and sacral(31.7%) spina bifida. The ratios of prenatal diagnosis on NTD by ultrasound examination in provincial, municipal, county, and factory hospital units were 55.7%, 59.4%, 49.0% and 57.2% respectively. The ratios of prenatal diagnosis of NTD by ultrasound examination from 1990 to 1993 were 53.5%, 55.8%, 60.7% and 54.7% respectively. There was an increase in the prenatal diagnosis of NTD by ultrasound examination from 1990 to 1993. The ratios of prenatal diagnosis of NTD in county hospitals by ultrasound examination were relatively low. Anencephaly, myelocele and meningocele were more frequently diagnosed by prenatal ultrasound examination.

Adult↗

PubMed2000

[Relationship between the changes of serum free fatty acids and insulin resistance in type 2 diabetics].

The purpose of this study was to investigate the changes of serum free fatty acids (FFA) in fasting state and absorptive state and the relationship between FFA changes and insulin resistance in the patients with type 2 diabetes (DM2). 75 g of glucose were given to 60 patients with DM2. Fasting serum FFA, serum insulin levels and the same parameters 2 h after glucose load were measured by calorimetric and RIA methods. Fasting and 2 h after oral glucose tolerance test (OGTT) plasma glucose(PG) levels were also assessed by using glucose oxidase method. The results showed the levels of serum FFA, PG and insulin of fasting and after glucose load in the patients were significantly increased and their insulin-sensitive (ISI) was remarkably decreased as compared with those in 30 normal controls, P < 0.05. Multiple stepwise regression analysis showed that the FFA level of 2 h after OGTT was negatively correlated with ISI, P = 0.0304. The results suggest that in patients with DM2, the levels of fasting and absorptive FFA are significantly elevated, which is negatively correlated with the decline of ISI, implying the association of abnormal fasting and absorptive FFA and insulin resistance in patients with type 2 diabetes.

Adult↗

PubMed2000

[Survey of the patients with oblique facial clefts in China].

OBJECTIVE: A descriptive study was conducted to investigate the epidemiological characteristics of oblique facial clefts in China. METHODS: From 1987 to 1992, data were collected from more than 500 hospital-based units involved in a monitoring program and were analyzed by the National Center for Birth Defects Monitoring. The monitored subjects were the hospitalized births from 28 weeks gestation to a period within 7 days after delivery. RESULTS: There were 71 cases of oblique facial clefts in 4,489,692 births with an incidence of 0.16/10(4) in China. The incidence of oblique facial clefts in the rural and urban areas were 0.19/10(4) and 0.14/10(4) respectively, 0.18/10(4) in males and 0.12/10(4) in females. No significant differences were found. The unilateral oblique facial clefts were counted for 80%, and bilateral cases 20%. The incidence of unilateral oblique facial clefts in males is higher than that in females. The perinatal mortality was as high as 51%. There are 76% cases with associated abnormalities, most of which involved the maxillofacial region. The most common associated abnormality is cleft lip with cleft palate. CONCLUSION: The incidence of oblique facial clefts in China is the same as those in other countries. There is an unilateral predominance in this defect, especially in males. The perinatal mortality of this defect is high.

China↗

PubMed2000

[Experimental studies on exons 5-8 of p53 gene mutation in laryngeal squamous cell carcinoma].

This study was designed to detect the point mutations of exons 5-8 of p53 gene in laryngeal squamous cell carcinoma (LSCC) and analyze their relationship. The detection of fresh tumor samples from LSCC patients was performed using silver staining PCR-SSCP method. From among 60 patients samples, 47 were positive in SSCP. Mutation rate was 78.3% (47/60). The results showed that the prevalence of p53 mutations in LSCC subjected to silver staining PCR-SSCP test were 50% (30/60) in exon 5, 11.67%(7/60) in exon 6, 41.6%(25/60) in exon 7, and 25%(15/60) in exon 8. The majority of the mutations were found in exon 5 and exon 7. Exon 5 and exon 7 of p53 gene may be the mutation hotspot in LSCC; they may be the critical position easily attacked by some carcinogen factors relating to LSCC.

Carcinoma, Squamous Cell↗

PubMed2000

[Nonsyndromic cleft lip with or without cleft palate in Chinese population: analysis of 3766 cases].

A retrospective study was conducted to evaluate the variation trend in the incidence and epidemiological characteristics of nonsyndromic cleft lip with or without cleft palate in Chinese population. From 1988 to 1992, data were collected from more than 500 hospital-based units involved in a monitoring program and were analyzed by the National Center for Birth Defects Monitoring. The monitored subjects were the hospitalized births from 28 weeks gestation to a period within 7 days after delivery, which included 3246 408 perinatals and 3766 cases. The total incidence of nonsyndromic cleft lip with or without cleft palate was 11.6/10,000; the total incidence of celft lip alone was 3.8/10,000 and that of cleft lip with cleft palate was 7.8/10,000; no significant variation was noted in the annual incidence from 1988 to 1992. The incidence in males was 13.3/10,000, and 9.5/10,000 in females; there was a significant difference (P < 0.01). Of all the 3766 cases, cleft lip with cleft palate accounted for 67%, unilateral cleft lip 28% and unilateral cleft lip with cleft palate 43%. Left cleft lip and left cleft lip with cleft palate constituted 21% and 29% respectively. The sex-ratio was 1.6:1 for nonsyndromic cleft lip with or without cleft palate. It could be concluded that the incidence of nonsyndromic cleft lip with or without cleft palate showed no variation trend in China. Although no difference was found between urban and rural areas, the susceptibility to the defect was higher in males than in females. Cleft lip with cleft palate was more common than other types. There was a predominance of unilateral defects, of which most were on the left side.

China↗

PubMed2000

[An epidemiological investigation of anotia and microtia in China during 1988-1992].

OBJECTIVE: To investigate the epidemiological characteristics of cases with anotia and microtia in China. METHOD: The birth defect monitoring program was undertaken by a hospital-based monitoring method in 443-588 hospitals from 30 provinces, cities and autonomous regions across China. Data including intrauterine death and stillbirth from 28 weeks of gestation to a period of 7 days postpartum were collected between 1988 and 1992. RESULTS: A total of 3,246,408 births was monitored from 1988 to 1992, in which 453 cases had anotia and microtia. The average incidence was 1.40 per 10,000 during the five-year period. The decreased tendency of incidence was noted during the period (chi 2 = 5.5588, P < 0.05). The incidence in the urban area was significantly higher than that in the rural area. There was no sex difference in the incidence of anotia and microtia. The incidence varied among 30 provinces with highest incidence in Xinjiang province (2.08 per 10,000 births) and lowest in the Inner Mongolia Autonomous Region (0.33 per 10,000 births). In cases with the defects of anotia and microtia, 60.4% were accompanied with other congenital malformations. The proportion of multiple malformations with microtia and anotia was significantly higher than that of isolated case (chi 2 = 36.9277, P < 0.01). The highest incidence of concurrent malformations was anophthalmia or microphthalmia (13.1%), followed by facial cleft (12.6%), neural tube defects (10.0%), limb reduction defects (9.6%) and polydactyly (5.4%). There were also 3.5% cardiac defects. CONCLUSIONS: The prevalence of anotia and microtia varied among provinces across China. The high proportions of cases with anotia and microtia had multiple malformations. Therefore, careful examination of other malformations in patients with anotia and microtia is necessary.

Abnormalities, Multiple↗

PubMed1999

Cadmium-induced apoptosis and changes in expression of p53, c-jun and MT-I genes in testes and ventral prostate of rats.

Apoptosis and a change in the expression of p53, c-jun and MT-I genes occurred in rats exposed to cadmium in a way known to cause carcinogenesis in testes and ventral prostate. In situ end labelling (ISEL), DNA electrophoresis, and RT-PCR methods were used in present study. Adult male Wistar rats were given a single (s.c.) injection of 0, 5, 10, or 20 micromol/kg CdCl2. Then 12, 48 or 96 h after administration of cadmium, animals were sacrificed. It was observed that cadmium markedly induced apoptosis in the testes at the dose of 5 micromol/kg while 10 and 20 micromol/kg cadmium caused more necrosis than apoptosis. Apoptosis in the ventral prostate was markedly induced by all the doses of cadmium and there was an obvious time- and dose-dependent relationship between apoptotic index (AI) and cadmium treatment. Far fewer apoptotic cells appeared in liver, compared to the testes and ventral prostate. p53 mRNA expression was clearly enhanced in the ventral prostate but clearly suppressed in the testes by cadmium exposure, and the time- and dose-effect was very clear. The expression level of p53 in the liver was not affected by cadmium treatment. Cadmium-induced overexpression of c-jun gene appeared at 12 h in the liver, but not until 96 h in the testes and ventral prostate. Although the MT-I gene was found to be expressed in all tissues, marked induction by cadmium of the expression of MT-I gene was only observed in the liver. These results indicate: (1) that apoptosis is an early mechanism of acute tissue damage by cadmium in the testes and ventral prostate; (2) that p53 and c-jun genes may be involved in cadmium-induced cytotoxicity (apoptosis) and related carcinogenicity in male reproductive tissues; and (3) that the enhanced expression of MT-I in the liver could protect this organ from cadmium-induced cytotoxicity (apoptosis) and carcinogenicity.

Animals↗

PubMed1999

A novel src homology 3 domain-containing adaptor protein, HIP-55, that interacts with hematopoietic progenitor kinase 1.

Hematopoietic progenitor kinase 1 (HPK1) is a member of the mitogen-activated protein kinase kinase kinase kinase (MAP4K) family and an upstream activator of the c-Jun N-terminal kinase (JNK) signaling cascade. HPK1 interacts, through its proline-rich domains, with growth factor receptor-bound 2 (Grb2), CT10-regulated kinase (Crk), and Crk-like (CrkL) adaptor proteins. We identified a novel HPK1-interacting protein of 55 kDa (HIP-55), similar to the mouse SH3P7 protein, containing an N-terminal actin-binding domain and a C-terminal Src homology 3 domain. We found that HPK1 bound to HIP-55 both in vitro and in vivo. When co-transfected, HIP-55 increased HPK1's kinase activity as well as JNK1's kinase activity. A dominant-negative HPK1 mutant blocked activation of JNK1 by HIP-55 showing that HIP-55 activates the JNK1 signaling pathway via HPK1. Our results identify a novel protein, HIP-55, that binds to HPK1 and regulates the JNK1 signaling cascade.

Amino Acid Sequence↗

PubMed1999

Neoplastic potential of rat tracheal epithelial cell lines induced by 1-nitropyrene and dibenzo(a,i)pyrene.

Our previous study showed that both 1-nitropyrene (1-NP) and dibenzo(a,i)pyrene (DBP) induced enhanced growth variants (EGVs) in primary cultures of rat tracheal epithelial (RTE) cells exposed in vivo. Cell lines were established from some of the EGVs. Further studies, using anchorage-independent growth in soft agar and tumorigenicity in athymic nude mice, were performed to determine the neoplastic potential of EGVs induced by 1-NP and DBP. Results show that three of five from DBP- and five of five from 1-NP-induced cell lines displayed anchorage-independent growth. The colony forming efficiency (CFE) from DBP-induced cell lines was 0.067 per thousand and CFE from 1-NP-induced cell lines was 0.151 per thousand. There is a significant difference between the two CFEs (mu = 12.08, P<0. 01). Two of five DBP- and five of five 1-NP-induced cell lines produced squamous cell carcinomas (SCC) in nude mice. The rate of tumorigenicity counted by injected sites was 20% (6/30) for DBP-induced cell lines and 57% (17/30) for 1-NP-induced cell lines. There is a significant difference between the results of tumorigenicity from the cell lines induced by the two different compounds (chi(2)=8.53, P<0.01). Neither of the two cell lines from spontaneously developed foci grew in soft agar or produced SCC in nude mice. It seems that the neoplastic potential of transformed RTE cells induced by 1-NP was higher than that of DBP.

Animals↗

PubMed1999

Hematopoietic progenitor kinase 1 is a component of transforming growth factor beta-induced c-Jun N-terminal kinase signaling cascade.

The c-Jun N-terminal kinase (JNK) signaling pathway is involved in transforming growth factor beta (TGF-beta) signaling in a variety of cell systems. We report here that hematopoietic progenitor kinase 1 (HPK1), a novel Ste20-like protein serine/threonine kinase, serves as an upstream mediator for the TGF-beta-activated JNK1 cascade in 293T cells. TGF-beta treatment resulted in a time-dependent activation of HPK1, which was accompanied by similar kinetics of JNK1 activation. The activation of JNK1 by TGF-beta was abrogated by a kinase-defective HPK1 mutant but not by a kinase-defective mutant of kinase homologous to Ste20/Sps1. This result indicates that HPK1 is specifically required for TGF-beta-induced activation of JNK1. We also found that TGF-beta-induced JNK1 activation was blocked by a kinase-defective mutant of TGF-beta-activated kinase 1 (TAK1). In addition, interaction between HPK1 and TAK1 was observed in transient transfection assays, and this interaction was enhanced by TGF-beta treatment. Both stress-activated protein kinase/extracellular signal-regulated kinase kinase (SEK) and mitogen-activated protein kinase kinase 7 (MKK7) are immediate upstream activators of JNK1. Although SEK and MKK7 acted downstream of TAK1, only a kinase-defective SEK mutant blocked TGF-beta-induced activation of JNK1, indicating that the TGF-beta signal is relayed solely through SEK, but not MKK7, in vivo. Furthermore, TGF-beta-induced activating protein 1 activation was blocked by a HPK1 mutant, as well as by TAK1 and SEK mutants. Taken together, these studies establish a potential cascade of TGF-beta-activated interacting kinases beginning with HPK1, a Ste20 homolog, and ending in JNK1 activation: HPK1 --> TAK1 --> SEK --> JNK1.

Calcium-Calmodulin-Dependent Protein Kinases↗

PubMed1999

The orphan nuclear receptor COUP-TFII is required for angiogenesis and heart development.

The embryonic expression of COUP-TFII, an orphan nuclear receptor, suggests that it may participate in mesenchymal-epithelial interactions required for organogenesis. Targeted deletion of the COUP-TFII gene results in embryonic lethality with defects in angiogenesis and heart development. COUP-TFII mutants are defective in remodeling the primitive capillary plexus into large and small microcapillaries. In the COUP-TFII mutant heart, the atria and sinus venosus fail to develop past the primitive tube stage. Reciprocal interactions between the endothelium and the mesenchyme in the vascular system and heart are essential for normal development of these systems. In fact, the expression of Angiopoietin-1, a proangiogenic soluble factor thought to mediate the mesenchymal-endothelial interactions during heart development and vascular remodeling, is down-regulated in COUP-TFII mutants. This down-regulation suggests that COUP-TFII may be required for bidirectional signaling between the endothelial and mesenchymal compartments essential for proper angiogenesis and heart development.

Animals↗

PubMed1999

Genetic alterations of cancer-related genes in glass fiber-induced transformed cells.

Our previous studies have shown that glass fibers induced morphological transformation in BALB/c-3T3 cells and that transformed cells possessed preneoplastic properties and transforming genes. In the current study, possible molecular mechanisms of glass fiber-induced cell transformation related to the activation and/or inactivation of cancer-related genes resulting from gene amplification and/or point mutations were investigated. Gene amplification was determined by Southern blot analysis of K-ras, H-ras, c-myc, and c-fos proto-oncogenes. Mutational spectra of the p53 tumor suppressor gene and the K-ras proto-oncogene were characterized by single-stranded conformation polymorphism and DNA sequencing. Southern blot analysis showed that gene amplification was found in 56% (K-ras and c-myc), 67% (c-fos), and 100% (H-ras) of glass fiber-transformed cell lines. DNA sequencing analysis revealed that both transition and transversion mutations occurred and were concentrated in exon 2 of K-ras and exon 4 of p53. In addition, multiple mutations in different codons were found in K-ras and p53 These results suggest that (1) glass fiber-induced cell transformation could be attributed to the activation of the H-ras, K-ras, c-myc, and c-fos proto-oncogenes and/or the inactivation of the p53 tumor suppressor gene by gene amplification and/or point mutations and (2) multiple mutations might be due to genomic instability resulting from chromosomal alterations induced by glass fibers.

3T3 Cells↗