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Biomedical subjects

Z Lin

Publications and source records attributed to Z Lin.

At least 163 records · Page 9Linked to original sources
PubMed1999

Gastric myoelectrical activity, gastric emptying, and correlations with symptoms and fasting blood glucose levels in diabetic patients.

BACKGROUND: The aims of this study were to determine the electrogastrogram (EGG) changes and gastric emptying rates in diabetic patients and to investigate the correlation between upper gastrointestinal symptoms, fasting blood glucose, and gastric myoelectrical abnormalities. METHODS: Fourteen patients with long-standing type 1 diabetes mellitus and dyspepsia symptoms participated in the study. EGG recordings were obtained 30 minutes before and during a 2-hour radionuclide gastric emptying test for a solid meal. Fasting blood glucose was determined immediately before the gastric emptying study. Symptoms of nausea, vomiting, early satiety, abdominal bloating, and pain were rated from 0 to 3. RESULTS: Nine patients (64%) had delayed gastric emptying with 84.6 +/- 4.5% retention at 2 hours. Seven patients (50%) had abnormal EGG findings. The postprandial power change in the EGG of the patients with delayed gastric emptying (-0.48 +/- 0.16 dB) was decreased compared with patients with normal gastric emptying (4.7 +/- 2.6 dB) (P = 0.079). In patients with abnormal EGGs, the mean symptom score was significantly higher than patients with normal EGGs (2.42 +/- 0.13 versus 2.0 +/- 0.16; P < 0.05). Compared with normal gastric emptying patients, patients with delayed gastric emptying had higher but not significantly different symptom scores (2.31 +/- 0.11 versus 2.08 +/- 0.30; P = 0.225). There was no significant difference in fasting glucose levels in delayed (252 +/- 61.2 mg/dl) versus normal (378 +/- 82 mg/dl) gastric emptying or abnormal (288 +/- 86.4 mg/dl) EGGs versus patients with normal (304 +/- 57.6 mg/dl) EGGs. CONCLUSIONS: Overall, 78% (11 of 14) of patients with diabetes had either gastric motility or myoelectrical abnormalities. Patients with abnormal EGGs had more severe symptom scores. In diabetic patients with symptoms of gastropathy, an EGG may provide an important screening test for diagnosing abnormal gastric motility.

Adult↗
PubMed1999

Gastric myoelectrical activity and gastric emptying in patients with functional dyspepsia.

OBJECTIVES: The aims of this study were to investigate gastric myoelectrical activity and gastric emptying (GE) and their relationship in patients with functional dyspepsia. METHODS: The study was conducted in 15 healthy volunteers (six women, nine men, mean age: 42 yr) and 15 patients (13 women, two men, mean age: 43 yr) with functional dyspepsia. Gastric myoelectrical activity was recorded using cutaneous electrogastrography (EGG) for 30 min in the fasting state and for 120 min simultaneously with GE monitoring after an isotope-labeled solid meal. The anterior/posterior images of the stomach were taken using a technetium scanner immediately after eating, and then at 1, 2, and 4 h to determine the percentage of gastric retention. The dominant frequency of the EGG, the change of the postprandial EGG peak power (deltaP), and the percentage of normal 2-4 cycles/min (cpm) slow waves during each recording session were calculated and compared between the patients and healthy subjects. RESULTS: The patients had a significantly lower mean percentage of 2-4 cpm slow waves, both in the fed state and in the fasting state, than did healthy subjects. Compared to the EGG in the fasting state, a significant increase of the EGG dominant frequency in the fed state was observed in healthy subjects but not in the patients. The mean postprandial EGG power increase in the patients was substantially less than in the healthy subjects during the first postprandial hour but similar during the second postprandial hour. The mean percentage of gastric retention in patients is substantially higher than in the healthy subjects, both at 2 h after eating and at 4 h after eating. Of 15 patients, nine (60%) had delayed GE (gastric retention at 2 h >50%) and 10 (66%) had abnormal EGGs (percentage of 2-4 cpm <70% and/or deltaP < 0). Eight of these 10 patients (80%) with abnormal EGGs had delayed GE. CONCLUSIONS: A high proportion of adult patients (60%) with functional dyspepsia have abnormally slow GE and abnormalities in gastric myoelectrical activity.

Adult↗
PubMed1999

Dopamine transporter: transmembrane phenylalanine mutations can selectively influence dopamine uptake and cocaine analog recognition.

Cocaine blocks the normal role of the dopamine transporter (DAT) in terminating dopamine signaling through molecular interactions that are only partially understood. Cocaine analog structure-activity studies have suggested roles for both cationic and aromatic interactions among DAT, dopamine, and cocaine. We hypothesized that phenylalanine residues lying in putative DAT transmembrane (TM) domains were good candidates to contribute to aromatic and/or cationic interactions among DAT, dopamine, and cocaine. To test this idea, we characterized the influences of alanine substitution for each of 29 phenylalanine residues lying in or near a putative DAT TM domain. Cells express 22 mutants at near wild-type levels, manifest by DAT immunohistochemistry and binding of the radiolabeled cocaine analog [(3)H](-)-2-beta-carbomethoxy-3-beta-(4-fluorophenyl)tropane (CFT). Seven mutants fail to express at normal levels. Four mutations selectively reduce cocaine analog affinities. Alanine substitutions at Phe(76), Phe(98), Phe(390), and Phe(361) located in TM domains 1 and 2, the fourth extracellular loop near TM 4 and in TM 7, displayed normal affinities for dopamine but 3- to 8-fold reductions in affinities for CFT. One TM 3 mutation, F(155)A, selectively decreased dopamine affinity to less than 3% of wild-type levels while reducing CFT affinity less than 3-fold. In a current DAT structural model, each of the residues at which alanine substitution selectively reduces cocaine analog or dopamine affinities faces a central transporter cavity, whereas mutations that influence expression levels are more likely to lie at potential helix/helix interfaces. Specific, overlapping sets of phenylalanine residues contribute selectively to DAT recognition of dopamine and cocaine.

Alanine↗
PubMed1999

Expression of peroxisomal proliferator-activated receptors and retinoid X receptors in the kidney.

The discovery that 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) is a ligand for the gamma-isoform of peroxisome proliferator-activated receptor (PPAR) suggests nuclear signaling by prostaglandins. Studies were undertaken to determine the nephron localization of PPAR isoforms and their heterodimer partners, retinoid X receptors (RXR), and to evaluate the function of this system in the kidney. PPARalpha mRNA, determined by RT-PCR, was found predominately in cortex and further localized to proximal convoluted tubule (PCT); PPARgamma was abundant in renal inner medulla, localized to inner medullary collecting duct (IMCD) and renal medullary interstitial cells (RMIC); PPARbeta, the ubiquitous form of PPAR, was abundant in all nephron segments examined. RXRalpha was localized to PCT and IMCD, whereas RXRbeta was expressed in almost all nephron segments examined. mRNA expression of acyl-CoA synthase (ACS), a known PPAR target gene, was stimulated in renal cortex of rats fed with fenofibrate, but the expression was not significantly altered in either cortex or inner medulla of rats fed with troglitazone. In cultured RMIC cells, both troglitazone and 15d-PGJ2 significantly inhibited cell proliferation and dramatically altered cell shape by induction of cell process formation. We conclude that PPAR and RXR isoforms are expressed in a nephron segment-specific manner, suggesting distinct functions, with PPARalpha being involved in energy metabolism through regulating ACS in PCT and with PPARgamma being involved in modulating RMIC growth and differentiation.

Adipose Tissue↗
PubMed1999

Novel, non-radioactive, simple and multiplex PCR-cRFLP methods for genotyping human SP-A and SP-D marker alleles.

We have previously identified an allele of the human SP-A2 gene that occurs with greater frequency in an RDS population [12]. Because of the importance of SP-A in normal lung function and its newly emerging role in innate host defense and regulation of inflammatory processes, we wish to better characterize genotypes of both SP-A1 and SP-A2 genes. It has been determined that SP-D shares similar roles in immune response. Therefore, in this report we 1) describe a novel, non radioactive PCR based-cRFLP method for genotyping both SP-A and SP-D; 2) describe two previously unpublished biallelic polymorphisms within the SP-D gene; 3) present the partial sequence of one new SP-A1 allele (6A14) and describe other new SP-A1 and SP-A2 alleles; and 4) describe additional methodologies for SP-A genotype assessment. The ability to more accurately and efficiently genotype samples from individuals with various pulmonary diseases will facilitate population and family based association studies. Genetic polymorphisms may be identified that partially explain individual disease susceptibility and/or treatment effectiveness.

Alleles↗
PubMed1999

Diabetes and disenrollment in a health maintenance organization setting: a 4-year longitudinal study with a matched cohort.

OBJECTIVE: The increasing enrollment of Medicare beneficiaries in health maintenance organizations (HMOs) in recent years has caused concern about whether HMOs and their providers have created an unfavorable environment for members who are chronically ill. This study was designed to examine whether there are any differences in disenrollment rates among enrollees with diabetes and enrollees without diabetes. RESEARCH DESIGN AND METHODS: This was a 4-year longitudinal follow-up study with a matched cohort. Medicare beneficiaries (aged > or =65 years) with diabetes identified through pharmacy records in 1994 were matched with a comparison group according to age, sex, comorbidities, and type of provider groups in an HMO in California. RESULTS: The overall distribution of the characteristics of members in the diabetic and matched nondiabetic group is almost identical. The matched-pair chi2 tests indicated that there were no statistical differences in disenrollment rates between diabetic and nondiabetic members during all three follow-up periods (P = 0.16-0.85). CONCLUSIONS: We found that the HMO members with diabetes did not disenroll from the HMO at a higher rate than those without diabetes. The findings should alleviate some of the concern that HMOs and their contracted providers have created an unattractive environment for members who have chronic diseases such as diabetes.

Aged↗
PubMed1999

[Monitoring of serum lidocaine concentration in tumescent liposuction infiltrated with high-dosage lidocaine and its clinical significance].

OBJECTIVE: This study was carried out to determine the maximum and safe dosage of lidocaine administered in tumescent liposuction. METHODS: In 14 cases of tumescent liposuction using high-dosage, low-concentration lidocaine as local infiltration anesthetic, serum lidocaine concentrations were monitored with automated fluorescence polarization analysis. RESULTS: The time-concentration curve together with clinical manifestations indicated that in tumescent liposuction, lidocaine, under a concentration of 0.1 mg/ml mixed with 1/1,000,000 to 1/2,000,000 epinephrine, could be administered with a dosage of 35 mg/kg body weight as a local infiltration anesthetic while the serum lidocaine was still within the safety limit and no signs of intoxication manifested. The resulting diminution both in pain and blood loss during the operation enhanced the overall operation safety and suction volume. CONCLUSION: This study provides the basis for high-dosage lidocaine administration in tumescent liposuction.

Adult↗
PubMed1999

[Expression of adhesion molecules beta 1 integrin on the surface of fibroblasts in wound healing].

OBJECTIVE: To investigate the relationship between the expression of adhesion molecules integrin beta 1 and the synthesis of collagen in wound healing. METHODS: In this study, integrin beta 1 expression on fibroblasts derived from granulated wound and from normal skin was compared by the technique of immunoelectron microscope and flow cytometry. The differences of ultrastructure between the two groups of fibroblasts were also observed. RESULTS: The results showed that the expression of alpha 5 and beta 1 subunits on fibroblasts derived from granulated wound were higher than those from normal skin. Endoplasmic reticulum attached with more ribosome in the former cells was richer than that in the latter cells. CONCLUSION: These results suggest that the expression of adhesion molecules integrin beta 1 appears to be associated with the synthesis of collagen in wound healing.

Adolescent↗
PubMed1999

[Effects of heat-shock pretreatment on the survival of island flaps in rats].

OBJECTIVE: This study was to develop a new method that can lessen ischemia reperfusion injury and improve the survival of the island flap. METHOD: A right lower abdominal island flap was created in the SD rat according to the protocol of Harashina. Animals were divided into 2 groups (heat-shock pretreatment and control groups). The island flap viability and electronic microscopical appearance of flap tissue were evaluated following ischemia reperfusion injury. In order to explore the mechanism of this phenomenon, we examined the contents of HSP70 and measured the levels of SOD and MDA of the flap at various times. RESULTS: Compared with the control group, SOD activities of the flap were higher, and MDA content was lower. Survival rate of the island flap with heat-shock pretreatment was significantly increased (P < 0.01). CONCLUSION: The heat-shock pretreatment can lessen ischemia reperfusion injury and improve the survival of the island flap. It is suggested that the mechanism be related to following aspects: 1. The heat-shock pretreatment maintains stability of cell's function and structure. 2. It may increase the ability to catabolize free radicals by antioxidative enzymes.

Animals↗
PubMed1999

[Human preadipocyte culture and the establishment of hyperplasia and hypertrophy model].

OBJECTIVE: To better understand hyperplasia and hypertrophy properties of human adipose tissue. METHODS: Using an "adhesion-ceiling" culture strategy, fibroblast-like cells from adult pure adipose granules were successfully cultured. RESULTS: The cells were highly homogeneous, highly proliferative and with a high differentiation rate. Their dynamic morphological changes, growth curve, glycerophosphate dehydrogenase pattern, oil red O staining, and reaction to insulin and dexamethasone all verified their preadipocyte identity. Under controlled conditions, the preadipocytes replayed their in vivo hyperplasia and hypertrophy process. CONCLUSION: In mature human adipose tissue there exist functionally active fractions that can be modified. This study laid the basis for further probing into obesity and fat autotransplantation.

Adipocytes↗
PubMed1999

Surgical treatment of hepatocellular carcinoma and related basic research with special reference to recurrence and metastasis.

OBJECTIVE: To summarize the progress of surgical treatment of hepatocellular carcinoma (HCC) and related basic research at the Liver Cancer Institute of Shanghai Medical University in the recent years, with special reference to recurrence and metastasis. METHODS: Published and unpublished update clinical and experimental data in the above-mentioned areas are summarized. RESULTS: Surgical resection has played an important role in improving prognosis of HCC, the 5-year survival were 63.4% for small HCC resection (n = 806), 39.6% for large HCC resection (n = 1061), 64.7% for cytoreduction (using hepatic artery cannulation and ligation) and sequential resection of initially unresectable HCC (n = 93), 56.0% for cytoreduction using transcatheter arterial chemoembolization (TACE) and followed by resection (n = 65), and 22.4% for hepatic resection with removal of tumor thrombi in portal vein (n = 103). Unfortunately, the 5-year recurrent rate after curative resection of HCC was up to 61.5%, which was mainly a result of intrahepatic "metastasis" and multicentric origin of HCC. Clinically, re-resection of subclinical recurrence yielded 56% of 5-year survival (n = 202); prevention of recurrence by transcatheter arterial chemoembolization (TACE) + Interferon, or LAK/IL-2 therapy have decreased 3-year recurrent rate from 33% to 11%-18%. In experimental aspect, metastatic human HCC model in nude mice (LCI-D20) and HCC cell line with metastatic potential (MHCC97) have been established; studies on HCC invasiveness in the molecular level revealed similar results that reported in other solid cancers, and small HCC showed slightly better biological characteristics as compared with large HCC; microvessel density (MVD) that reflecting angiogenesis adversely correlated with 5-year survival of small HCC; experimental interventions using antisense H-ras, bispecific antibody, BB94, as well as anti-angiogenic agents (TNP470, suramin, CAI, heparin, antisense VEGF, etc.) have been demonstrated to inhibit tumor growth and lung metastasis in nude mice model. CONCLUSIONS: Recurrence and metastasis are the major obstacle to further improve prognosis of HCC, studies should be conducted both in clinical and experimental aspects, "HCC invasiveness" will be the major target to be studied, particularly in the molecular level, and anti-angiogenesis will be one of the important approach.

Angiogenesis Inhibitors↗
PubMed1999

[A comparative study between clinical response and pathologic changes to preoperative chemotherapy in non-small cell lung cancer].

OBJECTIVE: To study the clinical response to preoperative chemotherapy in relation to pathologic changes in non-small cell lung cancer (NSCLC). METHODS: Forty-six stage I-IIIa NSCLC patients were given 1-2 courses of preoperative chemotherapy with mitomycin C (MMC) 6 mg.M-2 on day 1, vindesine (VDS) 2.5-3 mg.M-2 on day 1, day 8 and/or day 15, and cisplatin (DDP) 90 mg.M-2 on day 1 (MVP regimen). 'The treatment was recycled every 28 days. Clinical response was assessed according to WHO criteria. Pathologic changes of the resected tumor were categorized to 3 grades. Grade I: No tumor under gross and microscopic observation. Grade II: Grossly no tumor present but residual tumor cells under microscopic observation. Grade III: Tumor reduced in size with clear margins; marked tumor cells degeneration and necrosis accompanied with fibrosis. Grade IV: Active proliferation of tumor cells with invasion. Grade I-II was considered to be chemotherapeutically effective. RESULTS: (1) The clinical response rate was higher in patients who had received 2 courses than those received 1 course of treatment. More patients treated with 2 courses had their pathologic changes in Grade I-II than those treated with 1 course of chemotherapy but the response rate was not fully consistent with pathologic grading. (2) Pathologic grading significantly correlated with the extent of tumor involvement but not with the lymph node status. (3) Efficacy of chemotherapy should be evaluated jointly by the clinical response and grading of pathologic changes. (4) Chemotherapy with MVP regimen did not elicit severe toxic side effect. Nor did it lead to operative morbidity, operative mortality and a delay in postoperative recovery. CONCLUSION: Preoperative chemotherapy with MVP regimen is effective in the treatment of NSCLC in stage I-IIIa.

Adult↗
PubMed1999

[Study on antitumor activity and mechanism of Ganoderma polysaccharides B].

OBJECTIVE: To study the antitumor activity and mechanism of Ganoderma polysaccharides (GL-B). METHODS: Both in vivo and in vitro experiments were conducted in the study. Proliferation of tumor cells was detected by MTT method, tumor necrosis factor alpha (TNF alpha) was detected by biological assay, and interferon gamma (IFN gamma) by enzyme-linked immunosorbent assay (ELISA). The level of mRNA was detected with the method of reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: (1) GL-B 50, 100, 200 micrograms/ml inhibited the growth of implanted sarcoma 180 in vivo significantly and dose-dependently. (2) GL-B directly adding to the cultured medium neither induced HL-60 apoptosis nor restrained its proliferation in vitro. (3) The macrophages and T lymphocytes cultured medium treated with GL-B significantly induced HL-60 apoptosis and inhibited its proliferation. GL-B significantly increased TNF alpha and IFN gamma release and their mRNA expression in the cultured medium. CONCLUSION: The anti-tumor activity of GL-B was derived from promoting mRNA expression of TNF alpha and IFN gamma, resulting in TNF alpha and IFN gamma release.

Animals↗
PubMed1999

[Atypical pheochromocytoma].

OBJECTIVE: To improve the diagnosis and treatment of atypical pheochromocytoma. METHODS: 51 cases of pheochromocytoma were treated from July 1985 to August 1998. RESULTS: Of the 51 cases, 19 were atypical, and were characterized by silent tumor, pheochromocytoma in pregnancy, bilateral tumor, extraadrenal tumor, malignant tumor, and recurrent tumor. Open operation was performed for all kinds of cases in accordance with their special characteristics. CONCLUSIONS: Surgical extirpation is the only means for the treatment of atypical pheochromocytoma and meticulous perioperative management is essential.

Adrenal Gland Neoplasms↗
PubMed1999

[Two-dimensional finite element analysis for morphology of craniofacial hard tissue of people with anterior crossbite at early permanent dentition].

OBJECTIVE: To analyze the morphology of craniofacial hard tissue of people with anterior crossbite at early at early permanent dentition. METHODS: The craniofacial morphology of hard tissue of 80 cases anterior crossbite of the early permanent dentition was analyzed by a special computer software system for finite element analysis of two-dimensional cranio-facial structure. RESULTS: The size change of each element was smaller than shape change in cross-bite group, which suggested that the shape change was the main element change; The posterior cranial base was found abnormal in both male and female groups, with counterclockwise rotation occurring at posterior cranial base to some extent; The upper part of face and the maxillary suffered underdevelopment in both male and female groups; The most outstanding change in size and shape occurred at anterior and superior part of mental, with each component of counterclockwise rotation to varying degree. CONCLUSION: Abnormality that occurs in craniofacial hard tissue of people with anterior crossbite at early permanent dentition period is highlighted by abnormal skeletal shape change and rotation, and may be one of the fundamental factors causing crossbite.

Adolescent↗
PubMed1999

[The use of autogeneic residual auditory ossicles, allogeneic auditory ossicles and the allogeneic nasoseptal cartilage in tympanoplasty].

OBJECTIVE: In search of ideal substance(s) for middle ear reconstruction, various materials were used and investigated in tympanoplasty. METHOD: Up to may 1996, three kinds of materials were be used to reconstruct the ossicular chain: 1. Auto-ossicular residue reposition, 153 ears; 2. Homo-ossicle transplantation, 119 ears; 3. Homo-chondroseptum transplantation, 93 ears. We analysed and compared the middle and long-term results in these three groups. RESULT: 1. In auto-ossicular residue reposition group, 86.3% was satisfied 10 years postoperation; 2. The satisfaction rate was 76.5% in homo-ossicle transplantation group; and 3. In the group of homo-chondroseptum graft, 77.4% of satisfaction rate was reached. CONCLUSION: Auto-ossicular residue reposition is a better choice for ossicular chain reconstruction. That is responsible for its convenient, free of rejection, and better long-term results.

Adolescent↗
PubMed1999

Preliminary observation of one-site combined trabeculectomy and phacoemulsification in the management of cataract patients with drug-controllable glaucoma.

PURPOSE: To evaluate the effect of one-site combined phacoemulsification and trabeculectomy in the management of cataract patients with drug-controllable glaucoma. METHODS: Twenty-four cases (25 eyes) of cataract patients with glaucoma whose intraocular pressure could be controlled by drugs were observed. All had undergone one-site combined phacoemulsification and trabeculectomy. Intraocular pressure and visual acuity were observed. RESULTS: The follow-up was 1-21 months. Postoperative visual acuity was 0.4-0.6 in 9 eyes, 0.7-0.9 in 7 eyes and 1.0 or better in 9 eyes. Postoperative intraocular pressure was 2.17 +/- 0.764 kPa (16.28 +/- 5.73 mmHg), 1.83 +/- 0.90 kPa (13.74 +/- 6.77 mmHg) lower than that before surgery (t = 11.89, P < 0.01). Only one eye needed one drug to control intraocular pressure after surgery. CONCLUSIONS: One-site combined phacoemulsification and trabeculectomy is a safe, effective and convenient technique for the management of cataract patients with drug-controllable glaucoma.

Aged↗