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Biomedical subjects

S Zhou

Publications and source records attributed to S Zhou.

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

Severity of liver disease in liver transplantation recipients with hepatitis C virus infection: relationship to genotype and level of viremia.

Infection with hepatitis C virus (HCV) genotype 1b has been reported to be associated with more severe posttransplantation liver disease than infection with non-1b genotypes. To address this issue, we evaluated the outcome in 124 patients who underwent liver transplantation for chronic HCV infection. The HCV genotype and/or serotype responsible for infection was determined by four different methods. HCV RNA was detected in serum samples by polymerase chain reaction (PCR) amplification, and quantified by branched DNA assay. Disease severity was expressed as a histological score (which included grading of portal inflammation, lobular activity, fibrosis, and cytopathic changes). Median duration of histological follow-up was 25 months (range 1-75 months). Genotype was assignable in 112 (92.5%) patients. Genotypes responsible for infection were as follows: 1a = 32.2%, 1b = 27.3%, 2a = 7.4%, 2b = 8.3%, 3a = 14%, and mixed infection (more than one subtype) = 3.3%. Level of viremia, alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and total histological score were not significantly different in patients infected with type 1b compared with patients infected with other genotypes. While duration of histological follow-up was greater in patients infected with type lb versus other types (P = .02), by univariate and multivariate analysis neither HCV genotype (lb versus others), level of viremia nor duration of histological follow-up were associated with disease severity. Moreover, there was no significant difference in the actuarial graft survival in patients infected with type lb compared with that of patients infected with non-lb types (82% and 87% at 3 years, respectively). Reanalysis using HCV genotype 1 showed no association with disease severity, graft survival, and patient survival. We conclude that HCV genotype 1 and subtype 1b are not associated with disease severity or graft survival in liver transplantation recipients.

Adult↗
PubMed1996

Prophylaxis in liver transplant recipients using a fixed dosing schedule of hepatitis B immunoglobulin.

Prophylactic hepatitis B immunoglobulin (HBIg) reduces the risk of reinfection in hepatitis B surface antigen (HBsAg)-positive liver transplant recipients. In the medical center of this study, high-dose HBIg immunoprophylaxis is administered at a fixed dose of 10,000 IU monthly, and in this study, the long-term efficacy of this treatment regimen was examined. Of 52 HBsAg-positive liver transplant recipients, 24 were administered HBIg immunoprophylaxis, and 28 were administered no specific therapy; the 2-year recurrence rates (defined by the reappearance of HBsAg) were 19% and 76%, respectively. Fifty-four percent of the HBIg-treated patients were positive for HBeAg or hepatitis B virus (HBV) DNA (by hybridization assay) pretransplantation. In patients administered monthly HBIg, intrapatient and interpatient variability in trough antibody to HBsAg (anti-HBs) titer was significant, highlighting the potential difficulties of using anti-HBs titer to guide therapy. Trough anti-HBs titers were less in patients who became HBsAg positive than in patients who remained HBsAg-negative (490 vs. 1290 mIU/mL) (P = .0001), reflecting either the cause or effect of HBV reinfection. Of 9 patients who remained HBsAg-negative and who were administered monthly HBIg for at least 1 year, HBV DNA by polymerase chain reaction amplification was detectable in the sera of 67%, the lymphocytes of 50%, and the liver of 57%. In conclusion, a fixed monthly dose of HBIg reduces the recurrence of HBs antigenemia, even in patients with indices of active viral replication pretransplantation. The presence of residual virus in the majority of patients administered HBIg suggests that long-term HBIg administration may be necessary.

Actuarial Analysis↗
PubMed1996

Effects of fatigue and sprint training on electromechanical delay of knee extensor muscles.

Electromechanical delay (EMD) of knee extensors in isometric contraction was investigated in six healthy men before and after four periods of 30-s allout sprint cycling exercise, conducted pre and post a 7-week sprint cycling training programme. The EMD was lengthened from 40.4 (SEM 3.46) ms at rest to 63.4 (SEM 7.80) ms after the fatiguing exercise (P < or = 0.05) in the pre-training test. During maximal voluntary contractions (MVC) conducted after the fatiguing exercise, the peak contraction force (Fpeak) and peak rate of force development (RFDpeak) were reduced by 51%-56% and 38%-50%, respectively (both P < or = 0.05). The mechanisms of EMD lengthening during fatigue could have been due to the deterioration in muscle conductive, contractile or elastic properties and require further study. The training programme increased the total work performed during the four periods of sprint exercise (P < or = 0.05). However, no significant training effects were found in the resting or postexercise EMD, Fpeak and RFDpeak during isometric MVC. These unchanged isometric contraction variables but enhanced dynamic performance suggest that isometric tests of muscle are insensitive to the neuromuscular adaptations to sprint training.

Adult↗
PubMed1996

Postnatal changes in the reticular lamina of the guinea pig organ of Corti.

The dimensions of the apical surfaces of hair cells were measured in guinea pigs, aged from 3 weeks before term to 25 weeks after birth. In the basal two-thirds of the cochlea, the apical surfaces of the outer hair cells and their supporting cells changed with age, shrinking in a direction radial across the cochlear duct. There was an associated widening of the angle of the 'V' of the rows of stereocilia. Further apically, between 12 and 16 mm from the base of the cochlea, the outer hair cells and their supporting cells underwent the opposite change, becoming wider in a radial direction with age. The changes were seen before birth and continued for more than 3 weeks after birth. The results suggest that the guinea pig cochlea continues certain developmental processes for a considerable time after birth.

Aging↗
PubMed1996

Topiramate: a potent anticonvulsant in the amygdala-kindled rat.

Topiramate, a chemically novel anti-epileptic drug, was evaluated in amygdala-kindled seizures in rats. Topiramate, given at doses between 0.63 and 80 mg/kg i.p. and p.o. 4 h before kindling stimulation, exhibited a dose-related inhibition on all seizure parameters measured, i.e. behavioral seizures, forelimb clonus, amygdala and cortical afterdischarges. The ED50 values obtained with topiramate on kindled seizures in all parameters tended to be lower than those observed on maximal electroshock seizures in rats. After oral drug administration, the ED50 values were: on forelimb clonus, 7.25 mg/kg; on amygdala afterdischarges 7.09 mg/kg and on cortical afterdischarges 7.12 mg/kg. After i.p. drug administration, the ED50 values were: on forelimb clonus, 10.6 mg/kg; on amygdala afterdischarges, 13.9 mg/kg and on cortical afterdischarges, 10.4 mg/kg. The data obtained after i.p. drug administration are in line with the suggestion that topiramate primarily blocks spread of seizures.

Administration, Oral↗
PubMed1996

The design and synthesis of substituted biphenyl libraries.

A novel scaffold system for the generation of diversity libraries has been designed which allows for rapid modification not only of functional groups, but their spatial arrangements as well. The biphenyl scaffold allows for display of three or four diverse functional groups in a wide variety of spatial arrangements depending on the substitution pattern selected. The libraries are generated by a combination of solution and solid-phase chemistries and are cleaved off the solid-support for screening.

Biphenyl Compounds↗
PubMed1996

Experimental study on reinnervation of vocal cord adductors with the ansa cervicalis.

The purpose of this study was to reestablish the adduction of the paralyzed vocal cord through reinnervation of the adductor muscles for unilateral vocal cord paralysis. In nine dogs, the adductor branch of the recurrent laryngeal nerve was anastomosed to the main branch of the ansa cervicalis. Six months later, various techniques of observation showed that seven of nine cases had excellent to good adduction during whining. Adduction was caused by reinnervation of the adductor muscles from the ansa cervicalis as demonstrated by laryngeal spontaneous and evoked electromyography, contraction tension, and various histologic findings. Therefore, the new technique could be a good treatment of unilateral vocal cord paralysis.

Animals↗
PubMed1996

Update: laryngeal reinnervation for unilateral vocal cord paralysis with the ansa cervicalis.

Eight patients underwent ansa cervicalis anastomosis to the adductor branch of the recurrent laryngeal nerve for unilateral vocal cord paralysis. They were followed long enough (at least 1 year) to determine if the procedure was successful. All cases have been subjected to preoperative and postoperative voice recording, acoustic analysis, and videolaryngoscopy. Some of them have been subjected to stroboscopy and electromyography (EMG). Data from these cases indicate that satisfactory phonatory quality may be achieved after the procedure. The reinnervated vocal cord neither abducted nor adducted, but it presented itself in midline for precise apposition with the normal cord. Synchronous mucosal waves in both vocal cords could be observed. EMG showed that the procedure produced satisfactory reinnervation of the adductory muscles. Therefore, the authors believe that the procedure could be proposed as an alternative to Teflon injection or thyroplasty in selected cases.

Adult↗
PubMed1996

Microsurgical replantation of the avulsed scalp: report of 20 cases.

Our 4-year experience with 20 patients who had suffered avulsion of 75 percent or more of the scalp is reviewed. All patients underwent replantation using microsurgical technique with 100 percent survival in 16, partial survival in 3, and failure in only 1 case. The emergency management and indications for replantation are demonstrated. The roles of sufficient preoperative preparation, generous debridement of damaged vessels, interpositional vein grafts, and the shortening of operative time in contributing to this success are emphasized. We developed a new surgical procedure called simultaneous vein grafts on donor and recipient sites in an effort to use less time in the anastomosis of interpositional vein grafts. Furthermore, we anastomosed the extra artery of the scalp to the vein on the recipient head when no suitable vein could be found. Intraoperative repair of the scalp sensory nerve and no postoperative use of any vasodilator or anticoagulant are discussed.

Adolescent↗
PubMed1996

[Ventilation effects of added jet air flows in different directions during expiratory phase on dogs with steam inhalation injury].

Nine dogs injured by inhaling steam were subjected to high frequency jet ventilation. Jet airflows of different directions were added during the expiratory phase, and their effects on respiration, circulation and improvment in ventilation efficiency of dogs with inhalation injury were compared, and the assessment of the mechanism of high frequency two-way jet ventilation in the trachea was made. According to the direction of added airflow during expiratory phase, the animal models were classified into three groups: Model A, the control group, without any added airflow; Model B, airflow opposite to the direction of ventilation was added; Model C, airflow of the same direction was added. The results showed: 1. Model B, with its CO2 elimination (Vco2) increased significantly (P < 0.01) and PaCO2 decreased significantly (P < 0.01), was preferable to Model A. This might be due to the reduction of dead space. 2. Model C, although there was slightly reduced anatomical and physiological dead space as compared with model A, showed worse ventilation effects. The mechanism was probably related to increase in PEEP (from 0.20 +/- 0.10 to 0.59 +/- 0.08 kPa) and FRC (from 433 +/- 59 to 504 +/- 7.0 ml). It is suggested that high frequency two-way jet ventilation is preferable for the treatment of inhalation injury with type 1 respiratory failure rather than high frequency ventilation with PEEP.

Animals↗
PubMed1996

[Laryngeal reinnervation by nerve-muscle multipedicle transfer].

Abductive ability was restored by means of a modified nerve-muscle pedicle technique, utilizing nerve-muscle multipedicle and multipoint implantation in seventeen dogs. The results showed that the procedure was superior to traditional Tucker's technique in functional recovery, electrophysiological activity and muscle strength which was also demonstrated by histochemical studies. There was little difference between double and three nerve-muscle pedicle transfer. The procedure has been used in three patients with bilateral vocal cord paralysis. Return of spontaneous abduction in the operated side in two patients was noted after eight and twelve weeks after surgery. All patients have achieved sufficient airway without the need of tracheotomy. Electromyography confirmed the reinnervation of posterior cricoarytenoid muscle.

Animals↗
PubMed1996

[Interleukin-6 and immune state in children with nephrotic syndrome].

IL-6 activities were determined in 37 children with idiopathic nephrotic syndrome (INS) by using an IL-6 dependent murine hybridoma-clone (MH60). The results showed that the levels of IL-6 activities in children with INS at the stage of onset were significantly higher than those of normal control group (P < 0.01), and the levels of IL-6 activities had positive correlation with the levels of urinary protein in 24 hours. The levels of IL-6 activities decreased remarkably at the stage of remission. CD+3 cells and the levels of serum IgG decreased significantly in those with INS; CD+8 cell increased and CD+4/CD-8 cell ratio decreased obviously in those with the simple nephrotic syndrome (SNS) at the stage of onset as compared with normal control group. These results indicate that there are immune disorders characterized by increased level of IL-6 activity in INS and suggest that IL-6 plays an important role in the development of INS.

CD4-CD8 Ratio↗
PubMed1996

[Improvement in model of mesangial proliferative glomerulonephritis of rat].

To establish a model of mesangial proliferative glomerulonephritis (MsPGN), we gave Sprague-Dawley rats staphylococcal enterotoxin B (SEB) intravenously twice in different times, bovine serum albumine (BSA) through digestive tract every other day, and Freud's adjuvant subcutaneously twice in different times, respectively. The results showed that measangial cells and matrix in glomeruli of rats began to proliferate at the end of 6th week and this change became obvious at the end of 8th week. The duration of experiment was shorter than that using only SEB, and the change of pathomorphology was stable. The experiment confirms the thesis that mucosal immunization of gastroenteric tract plays an important role in the development of MsPGN.

Animals↗
PubMed1996

[The serum MBP, myelin sheath immunohistochemistry and electromicroscope of expetrimental epilepsy rats].

We detected the level of myelin basic protein (MBP) in the serum of experimental epilepsy rats using simplified MBP ELISA, and the myelin sheaths of their brain with MBP immuno-histochemistry (IHC) and transmitted electronmicroscopy (TEM) in order to explore the relation of brain myelin sheaths and MBP to the pathogenic mechanism of epileptic seizure. The results show that the serum MBP level in the experimental epilepsy group is significantly higher than that in the control groups (P < 0.05), and is similar to that in some patients with generalized myoclonic seizures reported by us previously. The IHC and TEM findings in the brain of epilepsy rats indicate that the lamelliform structure of myelin sheaths in some part of hippocampus region becomes relaxing, disorderly and homogenized. Our studies imply that epileptic seizures are associated with MBP release from the subtle damaged regions of myelin sheaths during epileptic seizures, and the change of MBP component in myelin sheath may play and important role in the pathogenesis of epilepsy.

Animals↗
PubMed1996

[The study of the morphology of ultramicrostructure in molecular level of nucleus herniation of lumbar intervertebral disc].

In order to investigate the morphology of ultramicrostructure in molecular level of nucleus herniations, the authors studied the ultramicrostructure of three cases of nucleus herniations of lumbar intervertebral disc which were proved by operations and one case of normal nucleus pulposus of fresh corpse by using of atomic force microscope. The results showed that the arrangement of collagen bundle, collagen fiber and procollagen fiber were different between the two conditions, and the morphology of molecular particles of proteoglycan in nucleus herniations was different from that in the normal condition. In the condition of nucleus herniations, the collagen fiber formed procollagen fiber reticular porous adhering to the molecules of protein and proteoglycan, and the DNA adhering to the monochain of RNA in fiberal cell nuclei, in the form of bichain and multichain three dimensions helix structures. The banded structure (64-78 mm) of the procollagen fiber, and the collagenation and calcification of the degenerated nuclens pulposuses, the quantity of which was significant greater than normal (P < 0.05) indicated that the chronic injury of lumbar intervertebral nucleus pulposuses gave rise to the injury and break of the collagen fiber which resulted in twist (tangle) phenomenon so that nucleus pulposuses lost their normal resistance strength.

Adult↗