Transcriptional downregulation of tight junction protein ZO-1 in active coeliac disease is reversed after a gluten-free diet

Coeliac disease is an autoimmune enteropathy characterized by an enhanced permeability of the intestinal epithelial barrier. In epithelial cells paracellular permeability is regulated by intercellular tight junction. The cytoplasmic protein ZO-1 interacts directly with F-actin and plays a pivotal role in the structural and functional organization of tight junction.

AIM

The aim of this study was to investigate the expression and localization of ZO-1 in the intestinal mucosa of coeliac patients.

PATIENTS AND METHODS

Twenty patients with active coeliac disease, seven of whom underwent a repeat biopsy following a gluten-free diet and 27 control subjects, were studied. In all subjects, three biopsies were obtained from distal duodenum during upper gastrointestinal endoscopy. ZO-1 protein localization and levels were detected by immunofluorescence followed by confocal microscopy analysis and immunoblotting. ZO-1 mRNA expression was assessed by RT-PCR. F-actin distribution was also investigated.

RESULTS

In patients with active coeliac disease, both ZO-1 protein levels and mRNA were clearly reduced. Cytoskeletal organization was disrupted with F-actin staining concentrated at the subcortical and basal surface regions. Abnormalities in ZO-1 expression and actin organization were reversed after a gluten-free diet.

CONCLUSIONS

In active coeliac disease, ZO-1 protein expression is downregulated at the transcriptional level in association with F-actin redistribution. These changes are completely reversed after a gluten-free diet and could contribute to the increased intestinal paracellular permeability observed in this disorder.

HIV Lipodystrophy Case Definition using Artificial Neural Network Modelling

Objective

A case definition of HIV lipodystrophy has recently been developed from a combination of clinical, metabolic and imaging/body composition variables using logistic regression methods. We aimed to evaluate whether artificial neural networks could improve the diagnostic accuracy.

Methods

The database of the case-control Lipodystrophy Case Definition Study was split into 504 subjects (265 with and 239 without lipodystrophy) used for training and 284 independent subjects (152 with and 132 without lipodystrophy) used for validation. Back-propagation neural networks with one or two middle layers were trained and validated. Results were compared against logistic regression models using the same information.

Results

Neural networks using clinical variables only (41 items) achieved consistently superior performance than logistic regression in terms of specificity, overall accuracy and area under the ROC curve. Their average sensitivity and specificity were 72.4 and 71.2%, as compared with 73.0 and 62.9% for logistic regression, respectively (area under the ROC curve, 0.784 vs 0.748). The discriminating performance of the neural networks was largely unaffected when built excluding 13 parameters that patients may not have readily available. The average sensitivity and specificity of the neural networks remained the same when metabolic variables were also considered (total 60 items) without a clear advantage against logistic regression (overall accuracy 71.8%). The performance of networks considering also body composition variables was similar to that of logistic regression (overall accuracy 78.5% for both).

Conclusions

Neural networks may offer a means to improve the discriminating performance for HIV lipodystrophy, when only clinical data are available and a rapid approximate diagnostic decision is needed. In this context, information on metabolic parameters is apparently not helpful in improving the diagnosis of HIV lipodystrophy, unless imaging and body composition studies are also obtained.

A phase I/II study of the protease inhibitor ritonavir in children with human immunodeficiency virus infection

BACKGROUND

Ritonavir, a potent antiretroviral protease inhibitor, has been approved for the treatment of adults and children with human immunodeficiency virus (HIV) infection. In a phase I/II study, we assessed the safety, tolerability, and pharmacokinetic profile of the oral solution of ritonavir in HIV-infected children and studied the preliminary antiviral and clinical effects.

METHODS

HIV-infected children between 6 months and 18 years of age were eligible. Four dose levels of ritonavir oral solution (250, 300, 350, and 400 mg/m given every 12 hours) were evaluated in two age groups (</=2 years, >2 years). Ritonavir was administered alone for the first 12 weeks and then in combination with zidovudine and/or didanosine. Clinical and laboratory parameters were monitored every 2 to 4 weeks.

RESULTS

A total of 48 children (median age, 7.7 years; range, 0.5 to 14.4 years) were included in this analysis. Dose-related nausea, diarrhea, and abdominal pain were the most common toxicities and resulted in discontinuation of ritonavir in 7 children. Ritonavir was well absorbed at all dose levels, and plasma concentrations reached a peak 2 to 4 hours after a dose. CD4 cells counts increased by a median of 79 cells/mm3 after 4 weeks of monotherapy and were maintained throughout the study. Plasma HIV RNA decreased by 1 to 2 log10 copies/mL within 4 to 8 weeks of ritonavir monotherapy, and this level was sustained in patients enrolled at the highest dose level of 400 mg/m for the 24-week period.

CONCLUSIONS

The oral solution of ritonavir has potent antiretroviral activity as a single agent and is relatively well tolerated by children when administered alone or in combination with zidovudine or didanosine.

Pharmacokinetic enhancement of inhibitors of the human immunodeficiency virus protease by coadministration with ritonavir

Coadministration with the human immunodeficiency virus (HIV) protease inhibitor ritonavir was investigated as a method for enhancing the levels of other peptidomimetic HIV protease inhibitors in plasma. In rat and human liver microsomes, ritonavir potently inhibited the cytochrome P450 (CYP)-mediated metabolism of saquinavir, indinavir, nelfinavir, and VX-478. The structural features of ritonavir responsible for CYP binding and inhibition were examined. Coadministration of other protease inhibitors with ritonavir in rats and dogs produced elevated and sustained plasma drug levels 8 to 12 h after a single dose. Drug exposure in rats was elevated by 8- to 46-fold. A > 50-fold enhancement of the concentrations of saquinavir in plasma was observed in humans following a single codose of ritonavir (600 mg) and saquinavir (200 mg). These results indicate that ritonavir can favorably alter the pharmacokinetic profiles of other protease inhibitors. Combination regimens of ritonavir and other protease inhibitors may thus play a role in the treatment of HIV infection. Because of potentially substantial drug level increases, however, such combinations require further investigation to establish safe regimens for clinical use.

[Immigration from outside the European Community in Campania: results of empirical research in three provinces]

"The study is based on the results of empirical research and deals with non-European Community immigrants living in Campania [Italy]....The essential aspects analyzed in the study refer to immigrants' motivations, place and country of origin, working conditions at home and in the new environment, [and] characteristics of working activity in Campania. The final part deals with social integration and migrants' relations with local institutions. The specific character of Campanian immigration is for many reasons connected with a widespread irregular economy which deeply affects migrants' personal attitudes and strategies." (SUMMARY IN ENG AND FRE)

In vitro activity of A-86719.1, a novel 2-pyridone antimicrobial agent

This study evaluated the in vitro activity of A-86719.1, a novel 2-pyridone antimicrobial agent. The drug inhibited all tested members of the family Enterobacteriaceae at < or = 0.5 microgram/ml and all tested Pseudomonas aeruginosa, Burkholderia (Pseudomonas) cepacia, and Xanthomonas maltophilia strains at < or = 2 micrograms/ml. All but two strains of gram-positive bacteria were inhibited by < or = 1 microgram of the new drug per ml, including isolates highly resistant to ciprofloxacin.

Randomized double-blind trial of high- and low-dose fleroxacin versus norfloxacin for complicated urinary tract infection

Patients were entered in a double-blind, placebo-controlled, multicenter study to compare low- and high-dose fleroxacin with norfloxacin for the treatment of complicated urinary tract infection (UTI). A total of 296 patients were enrolled; 102, 97, and 97 patients were randomized to receive 200 mg of fleroxacin (low-dose), 400 mg of fleroxacin (high-dose), both once daily, or 400 mg of norfloxacin twice daily, respectively, for 10 days. Of these patients, 101, 94, and 95 were included in the safety analysis, and 71, 61, and 58 in the efficacy analysis. The main reason for exclusion from the efficacy analysis was failure to isolate a pathogen at baseline. The groups were comparable with respect to demographics. In the low-dose fleroxacin group, 68 (96%) of 71 patients had bacteriologic cures (eight with superinfection), compared with 56 (92%) of 61 in the high-dose fleroxacin group (two with superinfection) and 52 (90%) of 58 in the norfloxacin group (four with superinfection). Escherichia coli was the most frequent isolate in all groups. In the low-dose fleroxacin group, clinical cure was recorded in 61 (86%) of 71, improvement in six, and failure in four. In the high-dose group, clinical cure was noted in 58 (95%) of 61 patients, improvement in two, and failure in one. In the norfloxacin group, 50 (86%) of 58 patients were clinically cured, four were improved, and four failed. Clinical adverse events were reported by 22 (22%) of 101, 36 (38%) of 94, and 19 (20%) of 95 patients in the low-dose fleroxacin, high-dose fleroxacin, and norfloxacin groups, respectively. Insomnia and nausea were reported most frequently in the fleroxacin groups, and nausea and headache were most common in the norfloxacin group. The efficacy and safety of low-dose fleroxacin are comparable to those of norfloxacin for treatment of complicated UTI.

Superficial laser vulvectomy. IV. Extended laser vaporization and adjunctive 5-fluorouracil therapy of human papillomavirus-associated vulvar disease

Although most human papillomavirus infections can be managed satisfactorily by office methods, extensive, refractory, and dysplastic vulvar disease poses frustrating problems. This observational cohort study evaluated the efficacy of extended laser ablation (vaporization of both clinically apparent and adjacent subclinical changes) among 160 women drawn from 1000 referrals between 1982-1987. During the final 2 years, the protocol incorporated two different 5-fluorouracil (5-FU) regimens: routine once-weekly applications as prophylaxis against postoperative recurrence, and twice-weekly dosing to avoid further laser surgery among patients with early but diffuse failures. One hundred seven patients (66.9%) were controlled by a single operation. Subsequent therapy for the remaining 53 women involved 44 additional superficial photovaporizations, 38 courses of therapeutic 5-FU, four deep laser destructions with skin grafting, and six trials of systemic alpha-interferon. Eventually, 158 patients (98.7%) entered stable clinical remission. Adjuvant 5-FU improved success rates among the 76 women with two or more adverse prognostic factors (87.5 versus 55.8%; P less than .01) but had no prophylactic value in the other 84 women. In contrast, the therapeutic 5-FU regimen was generally effective, avoiding the need for further surgery in 22 (57.9%) of 38 inevitable failures, compared with only four successes (10.3%) among 39 historic controls managed with caustic agents (chi 2 = 19.5; P less than .001). Improvements in laser technology had no impact upon outcome, but more sophisticated heat containment strategies reduced postoperative pain, healing time, and morbidity. Given adequate technique and an appropriate indication, we find extended laser ablation to be an excellent primary control method. However, the availability of an effective adjuvant regimen would be a valuable complement.