Search PubMed⌕ Search

Biomedical subjects

Z Zhou

Publications and source records attributed to Z Zhou.

At least 379 records · Page 21Linked to original sources
PubMed1996

Identification of immune system and response genes, and novel mutations causing melanotic tumor formation in Drosophila melanogaster.

We are using Drosophila as a model system for analysis of immunity and tumor formation and have conducted two types of screens using enhancer detector strains to find genes related to these processes; genes expressed in the immune system (type A; hemocytes, lymph glands and fat body) and genes increased in expression by bacterial infection (type B). For type A, tissue-specific reporter gene activity was determined. For type B, a variation of enhancer detection was devised in which beta-galactosidase is assayed spectrophotometrically with and without bacterial infection. Because of immune system involvement in melanotic tumor formation, a third type was hypothesized to be found among types A and B; genes that, when mutated, have a melanotic tumor phenotype. Enhancer detector strains (2800) were screened for type A, 900 for B, and 11 retained for further analysis. Complementation tests, cytological mapping, P-element mobilization, and determination of lethal phase and mutant phenotype have identified six novel genes, Dorothy, wizard, toto, viking, Thor and dappled, and one previously identified gene, Collagen IV. All are associated with reporter gene expression in at least one immune system tissue. Thor has increased expression upon infection. Mutations of wizard and dappled have a melanotic tumor phenotype.

Animals↗
PubMed1996

Fetal and neoplastic expression of the neurotensin gene in the human colon.

OBJECTIVE: The authors identified various colon cancers that express the gene for the gut peptide neurotensin (NT/N). In addition, the authors sought to delineate the temporal pattern of NT/N gene expression in the human fetal colon. SUMMARY BACKGROUND DATA: Expression of NT/N is localized to the mucosa of the adult small bowel but also has been identified in the fetal colon, which resembles the small bowel until the end of the second trimester. Ectopic NT/N expression has been shown in certain types of colon cancer, suggesting a reversion to a fetal phenotype. METHODS: Sensitive ribonuclease protection assays were used to determine NT/N expression in colon cancers and adjacent normal mucosa as well as colon cancers established as tumor xenografts and fetal colon samples. RESULTS: NT/N gene expression was shown in 4 of 12 (25%) human colon cancer xenografts and in 11 of 40 (28%) freshly resected colon adenocarcinomas; NT/N gene expression was not expressed in any of the samples of normal colonic mucosa adjacent to the tumors. The NT/N gene was expressed maximally in the fetal colon between 16 and 18 weeks' gestation; NT/N expression was decreased between 19 and 22 weeks and was not apparent in either the 24-week fetal colon or the adult samples. CONCLUSIONS: The NT/N gene expression is expressed transiently in the fetal colon during a development stage that is characterized by morphologic similarity to the small bowel. In addition, NT/N is reexpressed in approximately one fourth of the human colon cancers, indicating that neoplastic transformation leads to reversion to a fetal phenotype in certain types of colon cancer. The NT/N gene will provide a useful model to further define the complex differentiation pathways in the normal gut as well as the process of fetal "dedifferentiation" in certain types of colon cancer.

Adenocarcinoma↗
PubMed1996

Transdermal prodrug concepts: permeation of buprenorphine and its alkyl esters through hairless mouse skin and influence of vehicles.

In vitro skin permeation of buprenorphine (BUP) and three of its alkyl ester prodrugs was evaluated using hairless mouse skin. The three esters selected were the acetyl ester (Ac-BUP), butyl ester (Bu-BUP), and isobutyl ester (Isb-BUP). These drugs were applied on the skin as saturated slurries in three vehicles commonly used to formulate agents for transdermal purposes: propylene glycol, polyethylene glycol 400 (PEG 400), and light mineral oil. Unique solubilities were found for each drug on each vehicle. Fluxes through hairless mouse skin were evaluated for each combination of drug and vehicle using Franz diffusion cells. From PEG 400 formulations, the skin fluxes of BUP, Ac-BUP, Bu-BUP, and Isb-BUP were 0.47 +/- 0.08, 1.64 +/- 0.31, 0.33 +/- 0.05, 0.75 +/- 0.20 micrograms/cm2/h, respectively. Thus, among the three potential prodrugs chosen, only Ac-BUP showed significantly higher skin flux than BUP. There were no inter-vehicle differences in the fluxes from saturated slurries between the vehicles. Moreover, all the esters were detected substantially in the form of regenerated parent drug (BUP) in the receptor compartment. Indeed, only Ac-BUP exited the skin in a measurably intact form, but the fraction escaping metabolism in transit was small (approximately 2%). However, based on drug dispositions in the skin, the regeneration of buprenorphine seems to depend on the alkyl chain length of the ester moiety. The molar percentages of regenerated parent drug in whole drug collected from the skin following the permeation experiments were: Ac-BUP, 9.2%; Bu-BUP, 40.7%; Isb-BUP, 9.6%, respectively. Thus, only Ac-BUP appears promising as a prodrug of buprenorphine, because it is not overly hydrophilic for skin permeation and is also highly metabolized to the parent compound while in the skin.

Analgesics, Opioid↗
PubMed1996

The Community Medical Alliance: an integrated system of care in Greater Boston for people with severe disability and AIDS.

The Community Medical Alliance in Boston has adapted principles of prepaid managed care to redesign service delivery for people with severe physical disability and with late-stage AIDS. Experience to date suggests that the flexibility of capitation can be used to substantially shift care from its usual hospital focus to clinicians in home and community settings, especially nurse practitioners, with a high degree of patient satisfaction and without apparent compromise in quality. Instead of limiting access, managed care can use prepayment to support early interventions, coordination, and the development of services specifically designed to meet the needs of the target population.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Diagnostic risk adjustment for Medicaid: the disability payment system.

This article describes a system of diagnostic categories that Medicaid programs can use for adjusting capitation payments to health plans that enroll people with disability. Medicaid claims from Colorado, Michigan, Missouri, New York, and Ohio are analyzed to demonstrate that the greater predictability of costs among people with disabilities makes risk adjustment more feasible than for a general population and more critical to creating health systems for people with disability. The application of our diagnostic categories to State claims data is described, including estimated effects on subsequent-year costs of various diagnoses. The challenges of implementing adjustment by diagnosis are explored.

Adolescent↗
PubMed1996

Alzheimer amyloid-beta peptide forms denaturant-resistant complex with type epsilon 3 but not type epsilon 4 isoform of native apolipoprotein E.

BACKGROUND: The apolipoprotein E (apoE) type epsilon 4 isoform specifies increased cerebral and cerebrovascular accumulation of amyloid-beta protein (A beta) and contributes to the genetic susceptibility underlying a large proportion (approximately 60%) of typical, sporadic Alzheimer disease. Unfortunately, in vitro biochemical studies of direct apoE isoform-specific interactions with A beta have been inconsistent, perhaps due to the use by different research groups of apoE isoform preparations in different conformational states (purified denatured versus native). MATERIALS AND METHODS: In the current study, we have investigated the possibility that synthetic A beta(1-40) preferentially associates with native apoE of either the type epsilon 3 or the type epsilon 4 isoform. RESULTS: Here, we demonstrate the preferential association of synthetic A beta(1-40) with native apoE epsilon 3. The complex between apoE epsilon 3 and A beta(1-40) could not be disrupted by sodium dodecyl sulfate. In a parallel assay, no denaturant-resistant association of A beta(1-40) with apoE epsilon 4 was detectable. CONCLUSIONS: These results support the notion that the apoE epsilon 4 isoform may foster beta-amyloidogenesis because apoE epsilon 4 is inefficient in forming complexes with A beta.

Amyloid beta-Peptides↗
PubMed1996

Experience in prevention of serious complications of laparoscopic cholecystectomy.

OBJECTIVE: To study the causes and prevention of the complications of laparoscopic cholecystectomy (LC). PATIENTS AND METHODS: Based on experience with 2 428 cases, the following should be paid attention to when dissecting and separating adhesions around the gallbladder and of the Calot's triangle. The best method for the prevention of mistaking the common bile duct (CBD) for the cystic duct is to find the junction of the cystic infundibulum and duct, separate the gallbladder wall along the infundibulum, and transect the cystic duct at the junction with the infundibulum. If dense adhesions around the gallbladder or of the Calot's triangle are met with, LC should be abandoned and open the cholecystectomy (OC) should be used instead. In separating the Calot's triangle, blunt dissection should be used to avoid burning the extrahepatic bile duct (EHBD), and blind hemostasis should be avoided. If the cystic artery lies in the upper part and the back of the cystic duct, the cystic duct should be dissected out, clipped and cut first, then the cystic artery be dealt with. If the cystic artery is in the front part of the pedicle of the gallbladder, the artery should be separated, clipped and cut first. Injury to the adjacent organs may be avoided by using electric coagulating hook correctly and avoiding accidental damage to the viscera, and keeping from viscera injury due to current chemotaxis in the closed cavity of the body. RESULTS: A total of 2427 patients were cured. One patient died of frequent episodes of supraventricular tachycardia and pneumonia on the 21st day after LC. CONCLUSION: If LC surgeons follow the above said principles of LC technique. LC is very safe for patients with benign diseases of the gallbladder.

Adolescent↗
PubMed1996

Clinical investigation of traditional Chinese medicine and pharmacy in treating respiratory tract infections in AIDS.

Based on the difference in severity of the disease and complications, 80 cases of acquired immune-deficiency syndrome (AIDS) accompanied with cough were divided into 2 groups: One treated by traditional Chinese medicine (TCM group), including 58 cases and the other treated by Integrated Chinese and Western medicine (integrated group), 22 cases. The therapeutic results show that in the TCM group there were 18 cases (31.03%) with clinical cure of the respiratory tract infection, 7 cases with therapeutic effect (12.07%) and 33 cases without any effect (56.90%), for a total rate of 43.10% therapeutic effectiveness; while in the integrated group there were 6 cases with clinical cure (27.27%), 2 cases with therapeutic effect (9.09%) and 14 cases without any effect (63.64%), the total rate of therapeutic effectiveness being 36.36%, slightly lower than in the TCM group and possibly related to greater severity of the disease or complications.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Using FIGO histologic grade to determine when to perform lymphadenectomies in endometrioid adenocarcinoma of the endometrium.

PURPOSE: Controversy remains as to whether selective pelvic and periaortic lymphadenectomies should be performed in low grade (grade 1 or 2) endometrioid endometrial cancer. The authors reviewed their experience over the last three years in their population of endometrioid adenocarcinomas of the endometrium to see if lymphadenectomies were necessary in low grade malignancies. METHODS: The records of all patients with endometrioid adenocarcinoma of the endometrium undergoing primary surgery by the gynecologic oncology service between November 1, 1991, and August 31, 1994, were analyzed for age, FIGO stage, grade, histologic type, lymphovascular space invasion, peritoneal cytology, and time to recurrence. RESULTS: Sixty-five patients with endometrioid adenocarcinoma of the endometrium were found. Twenty-five had grade I disease, 31, grade 2 disease, and 9, grade 3. Forty-seven patients had stage I disease, 5 stage II disease, 12 stage III disease and 1, stage IV disease. No patient with grade 1 disease had positive lymph nodes on examination. Six with grade 2 (19.4%) and two (22.2%) with grade 3 disease had positive lymph nodes. The percentage of patients with positive lymph nodes was not significantly different between those with grade 2 and 3 disease (p = 0.86) but was significantly different between grade 2 or 3 and grade 1 (p = 0.021) (p = 0.017). CONCLUSION: Pelvic and periaortic lymphadenectomies should be performed as part of standard surgical therapy in patients with FIGO grade 2 endometrioid adenocarcinomas of the endometrium. The decision as to whether to perform lymphadenectomies in grade 1 tumors must be left to the discretion of the surgeon since a chance exists that a higher grade or more deeply invasive tumor may be found on final pathological diagnosis.

Adenocarcinoma↗
PubMed1996

High level expression of oryzacystatin in Escherichia coli.

A rice cDNA library of immature seeds has already been constructed, from which colonies carrying oryzacystatin cDNA were isolated. The coding region of the oryzacystatin (a thiol proteinase inhibitor) gene was amplified by the Polymerase Chain Reaction (PCR) and inserted downstream of lambdaPRPL promoter of E. coli thermal-inducible expression vector pBV220. An oryzacystatin expression plasmid pBVC9 was therefore obtained. Shifting the culture temperature of E. coli DH5 alpha (pBVC9) from 30 degrees C to 42 degrees C led to a high level expression of oryzacystatin. The result of SDS-PAGE showed a distinct band of 12.0 kDa which accounts for at least 10% of the total soluble proteins. The inhibitory activity of the total soluble proteins of E. coli DH5 alpha (pBVC9) toward papain was confirmed by using that of E. coli DH5 alpha (pBV220) as a control.

Cloning, Molecular↗
PubMed1996

The amplification and expression of MDR1 gene in adriamycine resistant cell line of colon cancer cell HR8348.

P-glycoprotein plays an important role in highly drug resistant cells. But its high expression cannot be achieved by chemotherapy. In order to study the effect of P-glycoprotein on clinical tumors, we established a low ADM resistant colon cancer cell line HR/ADM and determined the amplification and expression of mdr-1 gene. The GLC/ADM showed a resistant pattern similar to classical MDR and the transcription of mdr-1 gene determined by RT-PCR increased. The immunocytochemical analysis showed strong positive staining with monoclonal antibody. The gene amplification of mdr-1 was clearly demonstrated by southern blot. Our results suggested that moderate expression of P-glycoprotein might be enough for a high resistant pattern.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

[Labeling DNA probe by polymerase chain reaction].

The use of polymerase chain reaction (PCR) for labeling probe has been demonstrated to offer various advantages including efficient labeling of DNA fragments as small as 72 bp, direct labeling of genomic DNA, and labeling with subnanogram amounts of input DNA. Therefore, a procedure for the nonradioactive labeling of chromasomal DNA 203 bp fragments of Helicobacter pylori with the hapten digoxigenin (Dig) by PCR has been developed. The results showed that the concentration of probe labeled by PCR was much higher than that by random primer labeled. PCR has the advantage of rapidity and economy. It is a very effective technique for synthesis of Dig-labeled DNA probe.

DNA Probes↗
PubMed1996

[The nonfunctional adrenal tumors: report of 30 cases].

79 cases of adrenal tumors were treated in our hospital from 1985 to Aprit. 1994. 30 of them had nonfunctional adrenal tumors. Data have shown that nonfunction adrenal tumor is not unusual. The detection rate of the disease will increase with the development and popularization of medical imageology which consists of B-ultrasonography and CT scanning etc. In this article, the diagnosis and treatment of this disease were discussed in detail with a review of the literature.

Adenocarcinoma↗
PubMed1996

[Determination of content of chlorpromazine hydrochloride in compound metamizole sodium microenema by acid-dye colorimetric method].

An acid-dye colormetric method was described for the determination of chlorpromazine hydrochloride in the compound preparation. The method was based on the reaction of chlorpromazine hydrochloride with methyl orange, to form a yellow complex, which then was extracted by chloroform and exhibited a maximum absorption at 424 nm. The optimal conditions for determination were selected by orthogonal design test. The linear range of this method was 20-120 micrograms/ml (r = 0.9997). The average recovery of the three sample solutions of different concentrations was 99.72% +/- 0.46% (n = 6). The other ingredients of preparation do not interfere with chlorpromazine determination. This method is more sensitive and accurate and can be used for quality control of this compound preparation.

Chlorpromazine↗
PubMed1996

[Experimental studies of segmental bone defects treated by skeletal external fixation].

Bony tissue of an average of 13.6% of the original length (OL) was resected from the tibia shaft in 26 mature goats. The fracture ends were compressively fixed with skeletal external fixation (SEF). Simultaneously, upper metaphysiotomy was performed to lengthen the tibia with a lengthening rate of 1.0 mm/d and a total lengthening 20.14% of OL. The restoration of blood circulation and the hemodynamic changes during the repair process of the compressively fixed bone ends and the metaphysiotomy site were studied with angiography, microvascular cast, Chinese ink permeated transparent thick slide, and radioactive microsphere measurement of regional blood flow (RBF). It was found that there were abundant vascular networks in the lengthened zone. The blood vessels not only could keep up with the same lengthening rate of growing, but also were gradually converted into the Haversian system in the newly formed cortex of the lengthened area. In the 2nd week after the cessation of bone lengthening, the RBF of the lengthened zone reached the maximum (54.56 +/- 8.53 ml/mm/100 g). It was also found that in the 7th postoperative week, the vessels of the cortex of the osteotomy shortening ends could grow across the space between them and anastomose with each other. The RBF at this time was 31.82 +/- 2.85 ml/mm/100 g. In the 12th week after operation, the RBF was still 2 times higher than that of the normal cortex (3.02 +/- 0.13 ml/mm/100 g). The primary healing could be observed under the wellreduction and stable compressive external fixation. These findings provide a theoretical basis for the clinical application of SEF for the treatment of tibial shaft defects or nonunion associated with limb shortening.

Animals↗
PubMed1996

[An experimental study of pathomorphology in the iris and ciliary body after intraocular lens implantation].

OBJECTIVE: To study the pathological changes and morphological features in the iris and ciliary body after lens extraction and intraocular lens (IOL) implantation in rabbits and discuss the mechanism of postoperative intraocular inflammatory response. METHODS: 27 adult pigmented rabbits were divided into three groups, (1) extracapsular lens extraction and IOL implantation. (2) simple extracapsular lens extraction, and (3) the control group without surgical intervention. The iris and ciliary body in every eye were taken on the 1st, 7th and 14th days after surgery, their pathological changes were observed with light microscopy, and the number of inflammatory cells were counted. The data were analyzed by using analysis of variance of SAS software. RESULTS: The pathological changes might be divided into three stages: (1) acute inflammation and exudative changes in the early stage (on the 1st day postoperatively), (2) subacute inflammation and granuloma formation in the middle stage (on the 7th day postoperatively, and (3) chronic inflammation and fibrosis in the late stage (on the 14th day postoperatively). CONCLUSION: The inflammatory cells in the iris and ciliary body are significantly higher in eyes with IOL implantation than that in eyes with simple extracapsular lens extraction (P < 0.01). Besides macrophages, there are many lymphocytes, eosinophils and plasma cells in the iris and ciliary body, suggesting that an active immune response exist in the inflammation.

Animals↗