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Biomedical subjects

G Zhang

Publications and source records attributed to G Zhang.

At least 577 records · Page 32Linked to original sources
PubMed1995

[The delayed traumatic intracerebral haematomas].

The results of CT observation of 378 inpatients with head injury were reported. 46 delayed traumatic intracerebral haematomas (DTICH) patients were found to have 71 haematomas. The incidence of DTICH was 12.2%. 80.7% of DTICH patients were noted 48 hours after injury. Most of them were young and middle aged persons. The places of baematomas were at the injured zones. The intracranial pressure continous monitor is useful to judge the DTICH during the early stage. Surgical operation is proposed for the patients with many haematomas and displaced central tissue. The haematomas should be cleansed for the frequently occurring haematoma patients. The death rate of the example was 17.4%, which was lower than 44%-71% reported elsewhere.

Adolescent↗
PubMed1995

Prevention of impairment in leprosy; results from a collaborative project in China.

OBJECTIVE: to evaluate programs of prevention and treatment of impairments due to leprosy in 8 geographical areas in the People's Republic of China. DESIGN: follow up of cohorts of leprosy patients receiving a range of different interventions. SETTING: 8 different geographical areas in China, varying in urban and rural characteristics from 6 provinces and 2 municipalities. SUBJECTS: leprosy patients who were receiving or had completed a course of antileprosy chemotherapy. INTERVENTIONS: a range of interventions, including steroids, self-care training, adapted footwear, surgery and provision of prostheses. MAIN OUTCOME MEASURES: changes in eye, hand and foot impairments between baseline assessment and assessment at 2 years. RESULTS: 232 out of 3571 patients assessed monthly over 2 years developed acute neuritis and, in most areas, were promptly and adequately treated. Regular self care of eyes was established in 238 out of 313 patients with lagophthalmos and was associated with reduction in the prevalence of conjunctivitis. Regular self care of hands was established in 730 out of 1010 patients with neurological impairment of the hand; this was associated with a reduction (80%) in hand cracks and wounds. Regular self care of feet was established in 745 out of 1094 patients with neurological impairment of the feet; this was associated with a 83% reduction in patients with cracks and a 33% reduction in patients with sole wounds. A footwear program was established in all 8 areas providing footwear to 4698 patients over the 2-year period; this was associated with a reduction of 61% and 21% in patients with cracks and wounds, respectively. Management of complicated sole wounds in 256 patients resulted in 69% of these patients being free of sole wounds at 2 years. Targets for reconstructive surgery and amputations were not fully attained, but lower limb prostheses were provided for 306 patients. CONCLUSIONS: leprosy is a chronic disease characterized by peripheral neuropathies which can result in increasing secondary impairments and disabilities. The emphasis, in countries such as China where the chemotherapy programs have been effectively implemented, is shifting to prevention and treatment of impairments. This innovative program in China has successfully demonstrated that it is possible to prevent and reverse impairments due to leprosy.

Artificial Limbs↗
PubMed1995

[Angiotensin II increasing the inhibitory effects of electroacupuncture on the nociceptive discharge of neurons in the spinal dorsal horn].

Experiments were performed on 53 rats. The nociceptive discharges of spinal dorsal horn neurons were extracellularly recorded by glass microelectrodes and tested for the effects of angiotensin II (A II) on the nociceptive discharges of spinal dorsal horn neurons and AII on the inhibitory effects of electroacupuncture (EA). The results showed as follows: (a) The nociceptive discharges of spinal dorsal horn neurons might be inhibited (25/35) or facilitated (10) with A II (50-500 ng/20 ul) applied to the surface of dorsal spinal cord (L2-3); (b) The facilitory effects (5/5) were observed with A II (2 ug/20 ul) applied to the surface of dorsal spinal cord; (c) The inhibitory effects of EA (20 Hz, 2-4 V, 5 min) could be increased with A II (250 mg/20 ul, 8/9). Therefore, A II may modulate the nociceptive response of spinal dorsal horn neurons and influence the effects of EA, and different effects can be produced when the different dosage of A II is applied to the surface of dorsal horn.

Angiotensin II↗
PubMed1995

[Microwave tissue coagulation for bladder carcinoma].

47 patients with bladder carcinoma were treated by microwave tissue coagulation (MTC) through urethra. The total effective rate was 100%. Among 43 patients followed-up, 17 had recurrence of the carcinoma 6-20 months after operation and received another MTC therapy successfully. This kind of treatment is indicated for tiny, multiple, scattered and reccurred tumor. It has advantages of safety, easy operation, fast effect, mild suffering. It is an ideal treatment for the patients who are intolerable or unwilling to accept major operation.

Adult↗
PubMed1995

[Scanning electron microscope observation on the eggs of Musca domestica vicina].

The surface structures of the eggs of house fly (M. domestica vicina) were examined by SEM. A layer of membranaous structure with small holes in clusters covering the whole egg was seen. The membranous structure is supported by large amount of tissue masses of different sizes. The submembranous tissue is dotted with numerous concave-holes. A hatching crack with a layer of very thin and vulnerable membrane runs lengthwise across the concave surface of the egg.

Animals↗
PubMed1995

[Detection of K-ras oncogene activation in human lung cancer and its possible clinical application].

By using a modified polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) technique, we detected K-ras codon 12 mutation in 102 formalin-fixed, paraffin-embedded tissues from surgical samples of lung cancer patients. The X2 test was used to determine the statistical significance of difference, according to the presence or absence of mutation in codon 12 of K-ras oncogene. We found 25 cases (24%) positive for mutation of K-ras 12 codon. Mutation occurred in 6 of the 40 cases (15%) of squamous cell carcinoma, 18 of 37 adenocarcinoma cases (49%), 1 of 2 adenosquamous cases, 0 of 1 carcinoid patient, but no K-ras activation was found in small cell carcinoma (0/22) cases. Analysis of the clinical and pathological features of 37 adenocarcinoma cases showed no apparent associations between the K-ras codon 12 mutation and sex, disease stage, tumor size (T), metastatic status (M) and the degree of differentiation (all P values greater than 0.05), but the nodes (N) of K-ras-positive adenocarcinoma tended to be more than the K-ras-negative ones (P < 0.01). From 26 male cases of adenocarcinoma mutation in codon 12 of K-ras occur more frequently in adenocarcinoma from smokers than non-smokers (P < 0.05), suggesting that smoking is an important factor in the induction of the mutation. Among 37 adenocarcinoma cases, only 25 cases can be traced the recurrence rate in 1-year. The 1-year recurrence rates were 85% (11/13) in K-ras mutational patients, more than 25% (3/12) in K-ras negative ones (P < 0.01), whereas there was no relationship between recurrence and differentiation in these 25 cases. The findings suggest the K-ras gene mutation may be one of the prognostic markers for human lung adenocarcinoma.

Adenocarcinoma↗
PubMed1995

[Clinical application prospect of digital subtraction technique for periapical radiographs].

The composition and functions of digital subtraction system for conventional radiographs were introduced. Based on the experimental test for this system, it has been found that digital subtraction system for conventional radiographs is very valuable for the diagnoses of minute bone lesions in the bifurcation, root side and apical part of the teeth as well as in the alveolar crest. In addition, the reproducibility of the projection geometry, the principle of digital subtraction and its clinical application prospect are also discussed in the present paper.

Humans↗
PubMed1995

Epidermal growth factor receptor and transforming growth factor alpha expression in papillary and nonpapillary renal cell carcinoma: correlation with metastatic behavior and prognosis.

Papillary renal carcinomas are a cytogenetically unique subset of renal carcinomas that have been reported to be clinically less aggressive. We have examined 19 papillary tumors for immunohistochemical expression of the epidermal growth factor receptor (EGF-R) and its ligand, transforming growth factor alpha (TGF-alpha). EGF-R and TGF-alpha expression was also studied in 149 nonpapillary tumors and 7 mixed papillary/solid tumors. EGF-R and TGF-alpha expression were compared to histology, stage, metastatic behavior, and survival. Formalin-fixed, paraffin-embedded nephrectomy specimens collected between 1977 and 1986 were stained with antibodies to EGF-R and TGF-alpha. Patients with papillary tumors were found to present with earlier stage disease and had significantly longer survival. Papillary tumors had a significantly lower rate of EGF-R positivity than solid pattern tumors (21% versus 73%, P < 0.001). Intermediate or strong cell membrane immunoreactivity for EGF-R was associated with high tumor grade and poor disease-specific survival. EGF-R positivity in the primary tumor was associated with the presence of metastatic disease and with metastatic spread to lung versus bone. Tumor parenchymal TGF-alpha staining was present in 50% of the cases and was not associated with stage or grade. Unrelated to tumor parenchymal TGF staining, tumor vessels stained for TGF-alpha in 56% of the cases. Vessel TGF-alpha staining was absent in papillary tumors (P < 0.001). The improved clinical behavior of papillary tumors as compared to nonpapillary renal tumors may be related, in part, to their relatively lower levels of EGF-R expression.

Adult↗
PubMed1994

Association of immunohistochemical staining for p53 with metastatic progression and poor survival in patients with renal cell carcinoma.

BACKGROUND: Mutations of the p53 gene have been found in many types of human tumors. In some tumors, p53 gene mutations are associated with advanced disease and poor prognosis. There is wide variation in the reported incidence of p53 mutation in renal cell carcinoma, and its prognostic significance for this tumor is unknown. PURPOSE: This retrospective immunohistochemical study was designed to examine associations between p53 immunostaining and histologic type, tumor grade, clinical behavior, and survival. METHODS: Paraffin-embedded nephrectomy specimens collected from 1978 through 1986 from 175 patients were immunostained for p53 using the D07 monoclonal antibody. Positive staining for p53 has been linked to the accumulation of mutant p53 protein. Thirteen specimens of concurrent metastatic lesions were available from 11 primary cases. Clinical follow-up information was available on 164 patients. RESULTS: Immunostaining for p53 suggested the presence of p53 mutation in 49 (28%) of 175 renal tumors studied. Staining was associated with high tumor grade and stage but not with cell type or histologic pattern. Eleven (85%) of 13 metastatic lesions stained positively for p53, versus only four (36%) of the 11 paired primary tumors. Immunostaining for p53 was strongly associated with poor survival among patients without distant metastases at presentation. In this group, 10-year disease-specific survival was 78% for patients with nonstaining tumors versus 48% for those with p53-positive tumors (P < or = .003). There was an 87% 10-year disease-specific survival rate for patients with nonstaining Robson stage 1 tumors versus a 62% 10-year survival rate for patients with p53-positive Robson stage 1 tumors (P < .01). Multivariate analysis showed p53 immunoreactivity to be an independent predictor of survival for patients with nonmetastatic renal cell carcinoma, whereas tumor grade was not. CONCLUSIONS: Positive p53 immunostaining in renal cell carcinoma is associated with metastatic disease and poor survival in patients with early-stage disease. IMPLICATIONS: In renal cell carcinoma, mutations of the p53 gene may allow or contribute to the acquisition of metastatic potential.

Adult↗
PubMed1994

Activation of adenosine A1 receptors underlies anticonvulsant effect of CGS21680.

Focal injection of the adenosine A2A receptor agonist CGS21680 (2-[p-(2-carboxyethyl)phenylethylamino]-5'-N-ethyl-carboxamidoaden osine) in the rat prepiriform cortex produced a reduction in the severity of bicuculline methiodide-induced motor seizures. The anticonvulsant effect of CGS21680 exhibited dose-dependency and modest potency (ED50 = 605 +/- 47 pmol/rat). Pharmacological characterization of the anticonvulsant response in the prepiriform cortex revealed a significant correlation between the potency of adenosine analogs as anticonvulsants and their respective affinities for adenosine A1 receptors in vitro. These results indicate that the low affinity of CGS21680 for adenosine A1 receptors is sufficient to account for the anticonvulsant activity of this compound in the rat prepiriform cortex.

Adenosine↗
PubMed1994

Age changes in mastication in the pig.

A comparative study of chewing in miniature pigs at three stages of dental development was carried out using electromyography and movement analysis. The mastication of the youngest pigs was characterized by longer burst durations of jaw muscles, particularly closing muscles, and greater relative jaw opening. Chewing side alternated irregularly and burst durations were variable. Between the intermediate and oldest ages, the parameters remained almost unchanged. Because the amount of dental development that occurred between the second two stages was just as extensive as that between the first two, progressive eruption cannot account for the age changes observed in mastication.

Age Factors↗
PubMed1994

Fabrication and characterization of glucose sensors based on a microarray H2O2 electrode.

A glucose sensor was recently developed by modifying an immobilized GOD (glucose oxidase) membrane and coating Nafion diffusion limiting membrane over an amperometric H2O2 MAE (microarray electrode), which was fabricated by using standard planar processing. The chip of the sensor is 2.5 mm by 15. The MAE is composed of an Ag/AgCl RE (reference electrode), a Pt CE (counter electrode) and two sets of Pt WE (working electrode), each set consists of five bands. Silicon nitride was chosen as the top insulator. Six MAEs different in both width and length of the band were examined and the MAE with the narrowest width (10 microns) of bands exhibits the best electrochemical performances. The glucose sensor based on the MAE B1-2 presents a linear range of 0.5-40 mM glucose at 37 degrees C with a 1/15 M phosphate buffer solution (pH = 7.0) as supporting electrolyte. The sensitivity, background current, response time, CV (coefficient of variation) and long-term stability of the sensor are 7.1 +/- 0.5 nA/mM, 2 +/- 0.5 nA, 30 s, 3.4% and 6 days respectively.

Biosensing Techniques↗
PubMed1994

Expression of epidermal growth factor receptor in invasive transitional cell carcinoma of the urinary bladder. A multivariate survival analysis.

Epidermal growth factor receptor (EGFR) immunoreactivity was evaluated in 85 cases of invasive transitional cell carcinoma of the bladder. The impact of EGFR staining on patient survival was compared with tumor stage, histologic grade, immunoreactivity for c-erb B-2 and proliferating cell nuclear antigen, flow cytometrically determined S-phase fraction and DNA ploidy, abnormal expression of blood-group-related antigens, and patient blood type. Using a new monoclonal anti-EGFR antibody reactive in formalin-fixed tissue, the authors found a significant correlation between EGFR expression and high tumor stage, and between EGFR expression and poor patient outcome. However, EGFR expression as a predictor of prognosis was not independent of stage. An intriguing association between patient blood type and patient survival was noted. Other indices did not predict patient outcome after data were adjusted for stage.

ABO Blood-Group System↗
PubMed1994

Effect of unilateral bite splint on mastication in the miniature pig.

Unilateral premature occlusal contacts are known to alter masticatory activity levels during clenching, but whether natural chewing is similarly affected is not known. The purpose of this study was to analyse the effects of a unilateral bite splint on mastication. Eleven experiments were carried out using three miniature pigs. Electromyography of the masticatory muscles and movements of the jaw were recorded during natural chewing before and after inserting a bite splint on the second and third deciduous premolars. In contrast to human clenching, the integrated activities of the jaw-closing muscles increased, especially on the contralateral side. The increases were mainly due to the prolongation of the burst durations. Jaw opening activity was increased as well. The frequency of mastication fell slightly and the animal preferred to chew food on the bite splint side. These results demonstrate the importance within the particular experimental conditions of the occlusal condition in regulating chewing behaviour.

Animals↗
PubMed1994

Vasodilation induced by substance P in guinea pig carotid arteries.

In the guinea pig carotid artery with an intact endothelium, substance P (SP, 10(-10)-10(-7) M) relaxed the norepinephrine- (NE) contracted smooth muscles transiently, in a concentration-dependent manner. Acetylcholine (ACh, 10(-6) M) produced a sustained relaxation. SP and ACh also relaxed muscles contracted with high-K (29.6 mM) solution, with a similar form but with a reduced amplitude compared with findings in NE-contracted muscles. In the presence of nitroarginine (10(-5) M) and NE, the ACh-induced relaxation was transient, with a reduced amplitude, whereas the SP-induced relaxation was not significantly changed. In muscles contracted with high-K solution containing nitroarginine, neither SP nor ACh produced relaxation. SP (> 10(-11) M) transiently hyperpolarized the membrane, but only when this peptide was applied from the intimal side of the intact vessel, and the peak amplitude reached approximately 20 mV from the resting potential at 10(-8) M. ACh transiently hyperpolarized the membrane (the peak amplitude being approximately 10 mV), in both the adventitial and intimal applications. In high-K solution, neither SP nor ACh produced hyperpolarization. The amplitude of hyperpolarizations produced by SP did not significantly change in the presence of nitroarginine, oxyhemoglobin, or indomethacin. Thus, SP-induced relaxation seems to be produced mainly by endothelium-derived hyperpolarizing factor-induced hyperpolarization.

Animals↗