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Biomedical subjects

G Zhang

Publications and source records attributed to G Zhang.

At least 685 records · Page 38Linked to original sources
PubMed1987

Grading of reflux by radionuclide cystography.

Over a three-year period, radionuclide cystography (RC) was performed on 145 patients. Of these, 31 nephroureteral units in 25 patients demonstrated vesicoureteral reflux by RC and also by radiographic cystography (XC). The RC and XC studies were performed within three months of one another. The grading of reflux was determined by RC and then compared with that of XC using the criteria for grading as established by the International Reflux Study Committee (IRSC). Of 18 nephroureteral units in 14 patients with grade II reflux by XC, 14 were similarly graded by RC (78%). Of five nephroureteral units in five patients with grade III reflux by XC, the correlation by RC was 100%. However, when grades II and III were combined into a single category of low-grade reflux, the correlation achieved between the two cystographic techniques was 100%. Of five nephroureteral units in four patients with grade IV reflux by XC, the correlation was 60%, and in three units in two patients with grade V reflux the correlation was 100%. When grades IV and V are combined into a category of high-grade reflux, a correlation of 100% is achieved. When the reflux is graded into the five IRSC categories, the overall unequivocal correlation between the two studies is 80%. However, when only two categories are used (low grade = grades II and III, and high grade = grades IV and V), a correlation of 100% is obtained.

Adolescent↗
PubMed1986

Urinary undiversion: indications, technique and results in 50 cases.

We present our experience with reconstruction of the diverted urinary tract in 50 patients divided into 3 groups according to the presence of neurogenic bladder dysfunction, severe renal failure or normally innervated bladders and sphincters with normal renal function. The over-all success rate of anatomical and functional reconstruction was 88 per cent and we expect it ultimately to increase to 94 per cent. However, because of a 2 per cent mortality rate and a 16 per cent major complication rate, we recommend that all other therapeutic options be considered carefully before undertaking urinary undiversion when the reconstruction involves use of intestinal segments.

Adolescent↗
PubMed1985

Cancer of the penis. Prognosis and treatment plans.

Sixty-one patients with clinical low-stage (Jackson Stage I) and 22 patients with clinical high-stage (Jackson Stage II or III or T3-4N0-1M0) carcinoma of the penis who were seen between 1952 and 1979 and followed for at least 3 years or until death were reviewed. The majority of patients with Stage I cancer were treated with partial penectomy, either with or without ilioinguinal lymphadenectomy. The remainder of patients with these early small lesions were treated with local excision or circumcision. Forty-one of the patients with this early penile cancer (Jackson Stage I or Tcis, T1N0M0 or T2N0M0) survived at least 3 years and were considered cured. The other 20 patients died of cancer (12 cases) or unrelated disease (8 cases). If the patients who died of other diseases are excluded, the corrected 5-year survival rate was 77%. Treatment failure was primarily due to metachronous inguinal metastases after initial treatment of the primary tumor and failure of response of metastatic disease to salvage treatment. Four factors probably were associated with a poor prognosis: large primary tumor, moderately to poorly differentiated cancer, younger age at onset, and inadequate initial treatment. In advanced (Jackson Stages II and III) disease, treatment by partial or total penectomy alone or in combination with radiation to inguinal nodes after penectomy produced 3-year or longer survival in only 2 of 9 patients, whereas treatment by early extended excision of both the primary lesion and the ilioinguinal lymph nodes produced 3-year or longer survival in 11 of 13 patients. The results suggest that local excision is appropriate only for carcinoma in situ. Partial penectomy and monthly follow-up for at least 1 year is appropriate for patients with small, well-differentiated primary tumors. Patients who have large or moderately to poorly differentiated primary tumors probably should undergo partial or total penectomy and immediate ilioinguinal lymphadenectomy.

Adult↗
PubMed1985

Involvement of spot 35 protein, a cerebellar protein, in modulation of Purkinje cell activity of the rat cerebellum.

Spot 35 protein, applied iontophoretically, produced inhibition of spontaneous Purkinje cell activity in most cells and augmented the NE- or 5-HT-induced inhibition of spontaneous discharges whereas it hardly affected the inhibitory response of Purkinje cells to GABA, taurine, and beta-alanine, and the excitatory response to glutamate. It is suggested that spot 35 protein may be involved in normal physiological operation of the cerebellum through modulation of the NE or 5-HT system.

Action Potentials↗
PubMed1985

Bilateral renal oncocytoma: report of 2 cases and literature review.

We report on 2 patients with bilateral renal oncocytoma treated in the last 5 years. One patient underwent bilateral partial nephrectomy for a solitary tumor in each kidney. Both tumors were confirmed to be renal oncocytomas by light and electron microscopic examination. After 4 years this patient had no evidence of local recurrence or distal metastasis. The second patient presented with bilateral multiple renal oncocytomas. Transabdominal bilateral renal exploration revealed 2 tumors in the right kidney and 3 tumors in the left kidney. Right radical nephrectomy and enucleation of the left renal tumors were performed. Examination by light and electron microscopy confirmed that all tumors from both kidneys were oncocytomas. Only 8 cases of bilateral renal oncocytoma have been reported in the literature, including our 2 cases. In 6 of these 8 cases the tumors were multicentric, which may be a characteristic of bilateral renal oncocytoma. Recognizing the coexistence of multicentricity and bilaterality is important because more conservative treatment is required. However, a favorable prognosis may still be anticipated.

Adenoma↗
PubMed1982

The structural analysis of hemoglobin Handsworth.

The present paper describes the structural analysis of an abnormal hemoglobin variant of alpha-chain found in a Chinese woman in the Hechi district of the Zhuang Autonomous Region of Guangxi, and finds it to be hemoglobin Handsworth (alpha 18(A16) Gly leads to Arg).

Amino Acid Sequence↗
PubMedDate not supplied

Hypothesis: naked plasmid DNA is taken up by cells in vivo by a receptor-mediated process.

Following the initial demonstration that intramuscularly-injected naked plasmid DNA (pDNA) is expressed in myofibers, it was shown that pDNA can be used for vaccination purposes. More recent studies have indicated that naked pDNA can also achieve high levels of transgene expression in vivo. This efficiency of naked pDNA expression, especially via intravascular route, is truly astounding. In this prospective review, we examine the possible mechanisms of naked pDNA uptake. The possible mechanisms; (a) large membrane disruption, (b) small membrane pores, and (c) receptor-mediated endocytosis, are considered in turn. Some recent original laboratory data relevant to these hypotheses are also presented.

Animals↗
PubMedDate not supplied

Time course of gene expression after plasmid DNA gene transfer to the liver.

BACKGROUND: High levels of expression in hepatocytes can be achieved after intraportal delivery of plasmid DNA vectors with up to 10% of all liver cells transfected. CMV promoter-driven expression is very high on Day 1 after injection, but is diminished strongly by Day 2. Expression slowly declines after 1 week. We describe experiments aimed at elucidating the reasons for this rapid decline in transgene expression. METHODS: Histological methods were used to determine the presence and extent of liver damage and hepatocyte proliferation. Viral and liver-specific promoters were tested to study promoter shut-off, Southern blotting was performed to determine the loss of the pDNA vector over time, and several mouse models were used to study the host immunological response. RESULTS: pDNA is lost rapidly early after injection, but remains at a relatively stable copy number after Day 4. Southern blotting experiments showed that plasmid DNA could be detected for at least 12 weeks after injection (0.2 copies per genome). The early rapid decline of expression is promoter dependent. A liver-specific albumin promoter resulted in similar levels of expression on Days 1 and 7, suggesting that promoter inactivation may be responsible for the instability of CMV promoter-driven expression. The slow decline in expression levels after 1 week appears to be the result of an immune response directed against the expressed transgene. Expression was much prolonged in immunosuppressed, immunodeficient, or antigen-tolerized mice. CONCLUSION: The present data suggest that if promoter inactivation can be overcome, intravascular delivery of plasmid DNA could be a highly efficient, simple and non-toxic liver gene therapy approach. Intravascular delivery of pDNA allows for the rapid screening of novel expression vectors in vivo.

Animals↗
PubMedDate not supplied

Chemical composition and microstructure of uroliths and urinary sediment crystals associated with the feeding of high-level cottonseed meal diet to water buffalo calves.

The chemical composition and microstructure of seven uroliths and four urinary sediment samples associated with the feeding of high-level cottonseed meal diet to buffalo calves were examined by chemical qualitative analyses, scanning electron microscopy (SEM), X-ray diffraction, and X-ray energy dispersive spectrometry (EDS). Struvite was a major component of kidney stones and of some bladder stones. The kidney stone sample appeared cracked under low power under SEM, aggregated into tiny balls under high power, and as a blade-like structure under even higher power. The bladder stone samples appeared finely granular or granular with various forms of prismatic crystals. The urinary sediments were prismatic crystals, with granules. The newly found prismatic crystals, which were rich in potassium and similar to struvite in crystal structure, were identified as potassium magnesium phosphate (KMgPO4.6H2O) in some bladder stones and urinary sediments. However, crystals which contained Mg and P only, which had been used for struvite identification, were not found by EDS examination in urinary sediments from fresh urine samples of buffalo calves fed the high-level cottonseed meal diet.

Animals↗
PubMedDate not supplied

Statistical modelling in specific case analysis.

In spite of the problems associated with the development of a statistical approach in specific case analysis, the potential of two statistical methods, logistic regression and Bayesian belief networks, has been investigated and found encouraging in the context of a database relating to child murders with a sexual connotation. Continual collaboration between statisticians and detectives would be needed in the collection of the data, the choice and construction of the models, and the interpretation of the results.

Adult↗