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Biomedical subjects

A Tran

Publications and source records attributed to A Tran.

At least 73 records · Page 4Linked to original sources
PubMed1997

Significance of serum immunoglobulin M to hepatitis C virus core in patients with chronic hepatitis C.

OBJECTIVES: Anti-hepatitis C virus (HCV) IgM antibodies were found in patients with both acute and chronic hepatitis C. The aims of this study were to determine the significance, in terms of liver disease, virological parameters, and response to interferon therapy, of IgM antibody to hepatitis C virus core protein (IgM anti-HCV-core) in the serum of patients with chronic hepatitis C. METHODS: The presence of IgM anti-HCVcore was investigated in 42 patients with chronic hepatitis C. Tests for IgM anti-HCVcore was carried out before interferon therapy. The patients received 3 MU of interferon-alpha three times weekly for 6 months. A response to interferon therapy was defined as normal transaminase activity and negative viremia at the end of treatment (month 6: response), and a sustained response was defined as normal ALT values and negative viremia for 6 months after completion of therapy. RESULTS: Sixteen patients (38%) displayed IgM anti-HCVcore. The mean Knodell score of the IgM anti-HCVcore-positive patients was significantly higher than that of the IgM anti-HCVcore-negative patients (11.5 +/- 3.4 vs. 9.1 +/- 3.1, p = 0.04), and the occurrence of IgM anti-HCVcore tended to be associated with serotype 1 virus (p = 0.08). Finally, a significantly higher percentage of responders to interferon at the end of therapy were IgM anti-HCVcore negative (p = 0.04), and only one patient with a ratio of sample to cutoff over 2.0 responded to interferon. CONCLUSIONS: IgM anti-HCVcore appears to be a simple serological marker of more severe liver disease in patients with chronic hepatitis C and may have relevance to the outcome of antiviral therapy.

Antiviral Agents↗
PubMed1996

The potential role of external beam radiation in preventing restenosis after coronary angioplasty.

The potential role of radiation in the prevention of coronary artery restenosis after angioplasty has generated much recent interest. Animal research and pilot clinical efforts have focused primarily on intraluminal methods of radiation delivery. This article reviews the experience to date with external beam radiation in restenosis prevention and suggests issues that should be considered from the standpoint of both external beam and intravascular radiotherapy. External beam radiation can certainly play an effective role in clinical studies of coronary artery restenosis, and a multicenter randomized trial of external beam radiation after coronary angioplasty has been initiated.

Angioplasty, Balloon, Coronary↗
PubMed1996

Effect of stiripentol on carbamazepine plasma concentration and metabolism in epileptic children.

OBJECTIVE: To study the relationship between the plasma concentration of stiripentol (STP), a new antiepileptic drug, and its inhibitory effect on the formation of carbamazepine epoxide (CBZE) in epileptic children treated with carbamazepine (CBZ) either alone or in combination with another antiepileptic drug. METHODS: Minimum plasma concentration of antiepileptic drugs was measured before initiation of STP therapy (day 0) and on days 28 (STP 60 mg.kg-1.day-1) and 84 (STP 90 mg.kg-1.day-1) by HPLC. RESULTS: The CBZE/CBZ plasma concentration ratio decreased exponentially with increasing minimum plasma STP concentration (r = 0.80). The asymptote of the curve allowed the calculation of the minimum plasma STP concentration required to obtain the maximum inhibitory effect, i.e. 6.7 mg.l-1. CONCLUSION: The inhibitory effect of STP on CBZ metabolism expressed as the CBZE/CBZ plasma concentration ratio is dependent on STP plasma concentration, with a maximum effect at an average of 7 mg.l-1. The present data suggest that in order to evaluate the anticonvulsant efficacy of STP as add-on therapy, the minimum plasma STP concentration should be maintained above 7 mg.l-1 and the dosage of CBZ should simultaneously be decreased in steps by more than 50% to minimize the change in CBZ plasma concentration.

Adolescent↗
PubMed1996

Expanded pelvic radiotherapy fields for treatment of local-regionally advanced carcinoma of the cervix: outcome and complications.

OBJECTIVE: Recent anatomic and radiographic studies have indicated that standard external beam radiation portals may not adequately treat the volume at risk in patients with local-regionally advanced cervical cancer. A feasibility study was undertaken to evaluate toxicity, outcome, and patterns of failure in patients with advanced cervical cancer treated by expanded pelvic radiation fields. STUDY DESIGN: Thirty-eight women with stages IIB and III cancers of the cervix confined to the pelvis were irradiated with curative intent with expanded pelvic radiation portals. Anteriorly and posteriorly, the median field length and width were 20 and 17.5 cm, respectively. Lateral fields had a median width of 16.5 cm, and the posterior border encompassed the entire sacral silhouette. The median external beam whole-pelvis dose was 4140 cGy, with overall point A dose boosted by brachytherapy to 8315 cGy. RESULTS: Stage IIB patients (n = 22) had a 4-year actuarial local control rate of 70%, freedom from distant metastases rate of 62%, and disease-specific survival rate of 76%. In stage III disease (n = 16), the 4-year actuarial local control, freedom from distant metastases, and disease-specific survival rates were 80%, 48%, and 53%, respectively. Radiographically determined nodal status was an important predictor of disease-specific survival and distant metastases but not local control. The 4-year disease-specific survival rate was 40% in 11 patients with nodal disease compared with 71% in 27 node-negative patients (p < 0.01). The rate of freedom from distant metastases was 36% in node-positive patients versus 67% in node-negative cases (p < 0.01). The actuarial overall 4-year severe late complication rate was 14.8%. CONCLUSION: This study has demonstrated that expanded fields for pelvic radiotherapy is feasible, well tolerated, and therapeutic. The pelvic field design concepts presented should be integrated into radiation oncology practice.

Antineoplastic Agents↗
PubMed1996

Prednisolone withdrawal therapy enhances the effect of human lymphoblastoid interferon in chronic hepatitis B. INTERPRED Trial Group.

BACKGROUND/AIMS: The aim of this multicentre, randomised, controlled, clinical trial was to evaluate the effect of prednisolone followed by lymphoblastoid interferon treatment in chronic hepatitis B. METHODS: Two hundred and thirteen patients with chronic hepatitis B were randomised to either prednisolone (2 weeks of 0.6 mg/kg/day, 1 week of 0.45 mg/kg/day and 1 week of 0.25 mg/kg/day) or matching placebo followed by a 2-week rest phase and then human lymphoblastoid interferon 10 MU daily for 5 days followed by 10 MU thrice weekly for 11 weeks. Of 200 evaluable patients, 33 (16.5%) were females, and 50 (25%) were male homosexuals. Thirty three patients (16.5%) had chronic persistent hepatitis, 145 (72.5%) had chronic active hepatitis and 22 (11%) had active cirrhosis. RESULTS: Survival analysis disclosed statistically significant effects of prednisolone pre-treatment on both HBeAg disappearance and HBeAg to anti-HBe seroconversion (log-rank test statistics 5.43; p = 0.02 and 4.75; p = 0.03). Observed HBeAg disappearance and HBeAg to anti-HBe seroconversion rates (placebo vs. prednisolone patients) were 28% vs. 44% and 23% vs. 38%. Six months after stopping interferon, HBV DNA was negative in 51% of prednisolone patients vs. 28% of placebo patients (Chi-square test statistic 6.13; p = 0.013). Prednisolone pre-treatment tended to be more effective in patients with higher transaminase levels and in patients with low levels of HBV DNA. Fifteen patients (7.5%) (13 within 1 year of follow-up) eventually lost HBsAg; 14 of these subsequently developed anti-HBs. Interferon treatment was modified in 102 patients (51%). Three out of 22 patients with cirrhosis (14%), one of whom received prednisolone pre-treatment, developed hepatic decompensation with a fatal outcome while on interferon treatment. CONCLUSIONS: Prednisolone pre-treatment significantly enhanced the treatment effect of lymphoblastoid interferon in terms of HBeAg clearance and seroconversion to anti-HBe. Treatment should be used with caution in patients with cirrhosis and avoided in patients showing signs, or with a history, of decompensated cirrhosis.

Adult↗
PubMed1996

Effects of cyclic enteral nutrition on the immunological status of malnourished patients.

The effects of 2 weeks of refeeding by cyclic enteral nutrition on chronically malnourished (mean global nutritional deficiency 19.9 +/- 1.1%) hospitalized patients were assessed in a prospective study with special attention paid to immunological status. All patients were immunodeficient, with cell-mediated immunity being more affected than humoral immunity. After 2 weeks of refeeding, nutritional status had improved by 29.8%. Initially abnormal parameters of humoral immunity (IgM, C3 and C4) improved significantly (P < 0.05) between day 0 and day 15. The following cell-mediated immunity parameters also improved significantly (P < 0.05): CD8, monocyte count, natural killer cell activity and skin tests. Short-term refeeding by cyclic enteral nutrition appears to be a safe and effective way of improving immunodeficiency in chronically malnourished patients, with predictable consequences on infection.

Journal Article↗
PubMed1996

Perforation of the small intestine in a patient with disseminated Pneumocystis carinii infection in AIDS.

Perforation of the small intestine due to a segmental transmural Pneumocystis carinii infiltrate of the whole circumference was found in a surgical resection specimen as the cause of an acute abdomen in a 48-year-old heterosexual male patient suffering from acquired immunodeficiency syndrome. On autopsy, a disseminated Pneumocystis carinii infection was found involving spleen, thyroid gland and lymph nodes. The origin of this disseminated infection was a recurrent and severe Pneumocystis carinii pneumonia, which was first diagnosed two years before death and was treated with success. The hitherto unknown complication of an extrapulmonary Pneumocystis carinii infection described here extends the spectrum of lethal complications of opportunistic infections in acquired immunodeficiency syndrome.

AIDS-Related Opportunistic Infections↗
PubMed1996

[Chronic hepatic encephalopathy treated by long-term intravenous administration of flumazenil in ambulatory care].

Treatment of chronic hepatic encephalopathy is difficult. Oral flumazenil has been proposed for long-term treatment but is not presently available on the market. We report the successful treatment of one case of chronic hepatic encephalopathy in cirrhosis without precipitating factors by low dose intravenous injections of flumazenil (Anexate, 1 mg/4 hours). Flumazenil is expensive and not always effective. We suggest reserving this treatment to highly selected patients (without precipitating factor, or after failure of first choice treatment).

Ambulatory Care↗
PubMed1995

[Anti-thyroid autoantibodies in hepatitis C. Thyroid function after interferon therapy in 4 patients].

Four female patients had chronic hepatitis C associated with antithyroid autoantibodies. Hepatitis C virus infection was evidenced by liver biopsy and a positive-four-antigen recombinant immunoblot assay. All four patients were euthyroid before interferon therapy. Recombinant interferon alpha was given at a dose of 3 millions units three times a week for 6 months. At the end of the treatment, serum aminotransferase levels were within the normal range. Two patients progressed to hypothyroidism and 2 patients remained euthyroid. One year after the end of the treatment, only one patient had hypothyroidism and another had normal serum aminotransferase levels. These case-reports suggest that interferon administration may induce thyroid dysfunction in patients with antithyroid autoantibodies at the beginning of treatment. Thyroid dysfunction may be reversed when cytokine is withdrawn.

Adult↗
PubMed1995

Anti-GOR and anti-thyroid autoantibodies in patients with chronic hepatitis C.

Anti-thyroid autoantibodies have been described in anti-hepatitis C virus (HCV)-positive patients. It has been suggested that the anti-GOR response is closely related to HCV infection and may reflect an HCV-associated autoimmune phenomenon. This study was designed to evaluate the humoral anti-GOR response in anti-HCV-positive patients with anti-thyroid autoantibodies (group 1, 22 patients) and to compare it with the response in anti-HCV-positive patients without anti-thyroid autoantibodies (group 2, 44 patients) and in anti-HCV-negative patients with autoimmune thyroiditis (group 3, 28 patients). The prevalences of anti-GOR in groups 1, 2, and 3 were, respectively, 72.7, 61.3, and 3.5%. Anti-GOR levels were higher in group 1 than in group 2 or group 3 (P = 0.0001). Moreover, comparison of the Anti-GOR levels of groups 1 and 2 also revealed a statistically significant difference (P = 0.008). Detection of more elevated anti-GOR levels in group 1 patients suggests that anti-thyroid autoantibodies in anti-HCV-positive patients may be related to HCV.

Aged↗
PubMed1994

Differential expression of ZAP-70 and Syk protein tyrosine kinases, and the role of this family of protein tyrosine kinases in TCR signaling.

TCR stimulation results in the tyrosine phosphorylation of a number of cellular substrates. We have recently identified a 70-kDa protein tyrosine kinase, ZAP-70, which associates with the human TCR zeta-chain after TCR stimulation. We report here the isolation and sequence of a cDNA clone that encodes murine ZAP-70. Murine and human ZAP-70 share 93% amino acid identity and are homologous to the 72-kDa protein tyrosine kinase Syk. Syk has been implicated in the signal transduction pathways of the B cell membrane Ig and high affinity IgE receptors, Fc epsilon RI. In addition, we examined the tissue distribution of ZAP-70 and Syk in human and murine thymocyte subsets, B cells, and peripheral T cell subsets. ZAP-70 protein is expressed in all major thymocyte populations, with the level of expression being comparable to that found in both CD4+ and CD8+ peripheral T cells. Although Syk protein is also present in all thymocyte subsets, expression of Syk protein is down-regulated threefold to fourfold in peripheral T cells. In contrast to ZAP-70, expression of Syk is 12- to 15-fold higher in peripheral B cells when compared with peripheral T cells. In addition, whereas T cell stimulation results in down-regulation of Lck, no significant change in ZAP-70 or Syk protein is detected. Finally, we provide evidence that both ZAP-70 and Syk can associate with the TCR after TCR stimulation. With the use of a heterologous expression system, we show that, like ZAP-70, Syk is dependent upon a Src-family protein tyrosine kinase for association with the phosphorylated zeta-chain. Thus, the differential expression of these kinases suggests the possibility of different roles for ZAP-70 and Syk in TCR signaling and thymic development.

Amino Acid Sequence↗
PubMed1994

Erythromycin strengthens the defective lower esophageal sphincter in patients with gastroesophageal reflux disease.

Motilin induces phase III activity of the gastrointestinal tract. Erythromycin has a motilin-like effect on the stomach and significantly increases the lower esophageal sphincter (LES) pressure in normal volunteers. This investigation was performed to evaluate the effects of erythromycin on esophageal function in patients with gastroesophageal reflux disease (GERD). Esophageal manometry was performed in 10 GERD patients before and after intravenous infusion of 500 mg of erythromycin. Values are expressed as mean +/- SEM. LES pressure increased from 13.9 +/- 2.9 mm Hg at baseline to 28.9 +/- 3.6 mm Hg after infusion of erythromycin (p < 0.01). The duration of contractions in the proximal, middle, and distal esophagus was significantly prolonged from 3.5 +/- 0.4 seconds, 3.8 +/- 0.4 seconds, and 4.1 +/- 0.5 seconds to 4.2 +/- 0.2 seconds, 4.6 +/- 0.5 seconds, and 5.6 +/- 0.6 seconds, respectively, after infusion of erythromycin (p < 0.05 for each comparison). Erythromycin did not effect esophageal body contraction amplitude or velocity, or the upper esophageal sphincter. Serum motilin decreased slightly after the administration of erythromycin. We concluded the following: (1) Erythromycin profoundly stimulates the defective LES in patients with GERD. This appears to be a direct motilin agonist-like effect rather than being mediated by release of endogenous motilin. (2) Erythromycin has less effect on the esophageal body, although it does prolong the duration of esophageal contractions.

Erythromycin↗
PubMed1993

High prevalence of thyroid autoantibodies in a prospective series of patients with chronic hepatitis C before interferon therapy.

After describing two cases of Hashimoto's thyroiditis associated with chronic hepatitis C, we set up a prospective study to assess the prevalence of thyroid autoantibodies (thyroglobulin and thyroid microsomal autoantibodies) in 72 chronic hepatitis C patients (43 men and 29 women; mean age = 51 +/- 2.1 yr) before interferon therapy admitted between January and December 1991 to our liver unit. Thyroid autoantibodies were systematically assayed in 60 chronic HBsAg-positive patients (34 men and 26 women; mean age = 50 +/- 2.2 yr), who served as controls. Antibody to hepatitis C virus was detected with a second-generation enzyme immunoassay and then confirmed with a recombinant immunoblot assay and a supplemental enzyme immunoassay using two beads. In chronic hepatitis C patients, no men had thyroid autoantibodies. Nine of 29 women (31%) had thyroid autoantibodies. Among them, six (20.7%) had high titers of thyroid autoantibodies, and two had hypothyroidism. In all nine of these women, hepatitis C virus viremia was detected on nested polymerase chain reaction (with primers located in the 5' untranslated region). One year later, titers of thyroid autoantibodies had increased in one patient. Three other patients progressed to hypothyroidism. We judged four of 29 patients (13.8%) to have Hashimoto's thyroiditis on the basis of their high titers of thyroid autoantibodies and biological features of hypothyroidism. In the control group, only one man had thyroid microsome autoantibodies, at a very low titer (1:100). The association between chronic hepatitis C and presence of thyroid autoantibodies is clearly confirmed (p = 0.021) by this study.

Autoantibodies↗