Effects of the human immunodeficiency virus type 1 Rev protein on reporter gene and host T-cell gene expression

The HIV-1 encoded regulatory Rev protein acts to selectively increase the cytoplasmic concentration of incompletely spliced viral mRNAs through interaction with the Rev responsive element (RRE). In addition, the Rev activation domain, believed to be a nuclear export sequence, has been shown to modulate the export of non-RRE containing RNAs (e.g. 5S rRNA, splicesomal U snRNAs). Recent evidence suggests Rev activity depends on interactions with cellular cofactors, leading to speculation that Rev utilizes a cellular RNA and/or a protein export pathway. Rev interactions with cellular cofactors could lead to sequestration of those cofactors from normal cellular activities, suggesting potential Rev effects on cellular gene products and their resultant activity. We have examined the role of Rev in modulating the expression of cellular gene products. Through transient cotransfection assays, we observed a consistent and significant decrease in the levels of luciferase and B-galactosidase activity in the presence of a Rev expressing construct. Cell fractionation studies demonstrated the nuclear retention of the luciferase gene transcripts. Surprisingly, similar effects were observed on constitutively expressed RNAs such as gamma-actin transcripts, and the 18S and 28S rRNAs. These results suggest Rev can disrupt the nuclear export of multiple classes of RNAs.

Interobserver agreement on endoscopic diagnosis of bleeding peptic ulcers

BACKGROUND

The aim of this prospective study was to evaluate the interobserver agreement of stigmata of recent hemorrhage of bleeding peptic ulcers.

METHODS

Sixty-one consecutive adult patients were enrolled in the study and nine (three junior and six senior) endoscopists reviewed standardized video recordings of endoscopic examinations. Interobserver agreement was evaluated using the kappa (kappa) index, intraclass correlation coefficient, and proportion of agreement. Observer bias and poorly trained observers were investigated.

RESULTS

Interobserver agreement was very good for oozing (kappa = 0.68), good for clot (kappa = 0.51), poor for spurting (kappa = 0.29) and visible vessels (kappa = 0.33), and excellent for the absence of stigmata (kappa = 0.82). Observer bias sometimes occurred and the number of poorly trained observers was low. The kappa indexes were significantly better in senior than in junior investigators: 0.48 +/- 0.16 versus 0.37 +/- 0.26, respectively, p < 0.05. The agreement between the in vivo evaluation and video tape recordings (intraobserver agreement) was good (kappa = 0.60 +/- 0.19). There was no training phenomenon between the first and the second half of the patient group.

CONCLUSIONS

The endoscopic classification of bleeding ulcers might be simplified by limiting grading to a few classes. Special attention should be paid to the training of endoscopists.

Endoscopic detection of early esophageal cancer in a high-risk population: does Lugol staining improve videoendoscopy?

BACKGROUND

The aim of this study was to prospectively compare the diagnostic accuracy of videoendoscopy, with and without Lugol staining, for the detection of esophageal cancer in alcoholic or smoking patients older than 40 years.

METHODS

Daily alcohol and tobacco consumption and overt and latent symptoms were noted. The 158 patients included were examined by videoendoscopy and with Lugol dye.

RESULTS

The mean consumption of alcohol and tobacco was 86 +/- 49 gm/day for 26 +/- 11 years, and 30 +/- 18 pack-years, respectively. Twenty-five patients had no symptoms. Before Lugol staining, 12 patients had endoscopically identified cancerous lesions. After Lugol staining, 13 patients had 17 esophageal cancers, 3 of which were high-grade dysplasia. The prevalence of esophageal cancer was 8.2%: 95% CI [4,14]. Dye-free surfaces were significantly larger than the endoscopic patterns observed before Lugol staining (11.6 +/- 9.2 cm2 vs 1.4 +/- 1.7 cm2; p < 0.02).

CONCLUSIONS

In an alcoholic smoking population, the prevalence of esophageal cancer detected by endoscopy is high and not related to symptoms described by patients. Lugol staining only moderately improves the diagnostic accuracy of videoendoscopy; its main advantage is the assessment of the mucosal extension of esophageal cancer.

Diagnostic strategies for extrahepatic cholestasis of indefinite origin: endoscopic ultrasonography or retrograde cholangiography? Results of a prospective study

BACKGROUND AND STUDY AIMS

Due to its lower morbidity, it has been suggested that endoscopic ultrasonography (EUS) might replace endoscopic retrograde cholangiography (ERC) in the management of extrahepatic cholestasis of unknown origin. The present study aimed to compare the diagnostic accuracy of EUS and ERC in the management of cholestasis of unknown origin, taking into account the patient's general status and the necessity of endoscopic therapy.

PATIENTS AND METHODS

Sixty-eight patients with cholestasis of unknown origin were studied prospectively. EUS followed by ERC was carried out on a blinded basis by two endoscopists; diagnostic and therapeutic suggestions were made after either examination. During the ERC procedure and before withdrawing the tube, the endoscopist provided the final conclusions and carried out appropriate endoscopic treatment.

RESULTS

A correct diagnosis was obtained with EUS and ERC in 94% and in 92% of cases, respectively (not significant). After EUS, diagnostic ERC was necessary for diagnosis and therapy in 24% and 58% of cases, respectively. After ERC, EUS was requested in 41% of cases. The higher the American Society of Anesthesiologists (ASA) grade, the less it was necessary to perform a complementary investigation. In ASA grade 1 patients, endoscopic therapy was suggested in 38% of cases after EUS and in 33% after ERC (not significant); in ASA grade 3 patients, it was suggested in 93% of cases.

CONCLUSIONS

The diagnostic sensitivities of EUS and ERC are similar for extrahepatic cholestasis. ERC is first indicated in poor candidates for surgery, since endoscopic therapy is frequently required. In good candidates for surgery, EUS should be carried out first in order to stage a tumor or identify choledocholithiasis.

What role can endoscopy play in the management of biliary complications after laparoscopic cholecystectomy?

BACKGROUND AND STUDY AIMS

This study was carried out to establish the indications for biliary endoscopy due to biliary complications after laparoscopic cholecystectomy (LC).

PATIENTS AND METHODS

One hundred nineteen patients (36 men, 86 women; median age 59, range 16-93) were referred for endoscopic retrograde cholangiopancreatography (ERCP) to five centers between 1990 and 1994, and included in the study. The delay between LC and ERCP was 105 +/- 21 days.

RESULTS

Four types of complications were observed. a) Fifty-seven patients had residual stones or clip migration into the common bile duct (CBD); all were successfully treated with endoscopic sphincterotomy (ES). b) Twelve major injuries to the CBD were diagnosed by ERCP; successful surgical repair was carried out in most of these cases. c) Twenty patients had a partial biliary stricture; endoscopic stenting was attempted as a primary procedure in eight patients, with a satisfactory outcome in five (63%). d) Thirty patients had a bile leak; endoscopic therapy (26 patients) led to recovery in 18 (69%). The benefit of endoscopic treatment was less clear in five (19%); ES failed to bring about improvement in three patients (12%).

CONCLUSIONS

ERCP is indicated when a biliary complication is suspected after laparoscopic cholecystectomy. Endoscopic sphincterotomy is effective for the treatment of retained stones, clip migration, and bile leakage. Endoscopic stenting may be offered as a primary option in partial CBD strictures.

Crystallographic investigation of the dependence of calcium and phosphate ions for notexin

The crystal structure of the neurotoxic phospholipase A2, notexin, revealed three binding sites for sulphate ions which were suggested to be phosphate binding sites of importance for the activity of the toxin. The present investigation shows that the sulphate ion bound to the major binding site alters the structure of residues 60-75. In the absence of sulphate and phosphate, the structure of this loop has a conformation which partly resembles the non-neurotoxic PLA2s. The affinity of notexin for phosphate is 17 microM, as measured by the increase in fluorescence at 345 nm. Since the concentrations of phosphate and sulphate ions in blood plasma are 3 and 1 mM, respectively, the binding site must be occupied under physiological conditions. This major sulphate/phosphate binding site explains the specific affinity labelling by pyridoxal phosphate. Pyridoxal phosphate binds to this anion binding site which allows the reaction with Lys-88 or Lys-89. The structure of notexin in the presence and absence of Ca2+ shows only small local structural differences.

Endoscopic ultrasonographic signs of portal hypertension in cirrhosis

BACKGROUND

Endoscopic ultrasonography (EUS) has been suggested to investigate portal hypertension (PHT). We compared EUS and endoscopy in the exploration of PHT in cirrhosis.

METHODS

In 58 patients with cirrhosis and 16 controls, the presence of esophageal varices and gastric varices was recorded by both endoscopy and EUS, peridigestive varices and perforating veins by EUS. Relationships of patterns with each other and with clinical and biologic data were evaluated.

RESULTS

In patients with cirrhosis: esophageal varices were found by endoscopy and EUS in 88% and 55% of cirrhotic cases (p < 0.01), and gastric varices in 17% and 41%, respectively (p < 0.01). Perforating veins, below the gastroesophageal junction, were diagnosed by EUS in 40% of cases and never in controls. A significant relationship was found between perforating veins and the following patterns: peri-digestive varices, gastric varices at EUS, and esophageal varices at endoscopy. In patients with and without cirrhosis: after multivariate analysis, only esophageal varices at endoscopy were independently related to cirrhosis. However, in Child-Pugh class A patients, both esophageal varices and perforating veins were independently related to cirrhosis (diagnostic accuracy, 92%).

CONCLUSIONS

EUS is of limited value in the diagnosis of cirrhosis because it gives little additional information to upper gastrointestinal endoscopy. The relationships between perforating veins, varices, and peridigestive varices support the hypothesis that perforating veins are important in the pathogenesis of esophageal and gastric varices.

A model of community mobilization for the prevention of HIV in women and infants. Prevention of HIV in Women and Infants Demonstration Projects

The prevention of HIV in Women and Infants Demonstration Projects use a conceptual model for maximizing broad community participation for HIV prevention called the Community Mobilization Framework. The projects' comprehensive approach attempts to bring about changes on a community level using a model which encourages community-wide participation of persons with various roles and relationships in the community. The Community Mobilization Framework is one way to systematically conceptualize the organization of the community for the purpose of mobilizing the maximum number of community members around a common health initiative. A community becomes mobilized around an issue by endorsing health-enhancing attitudes, behaviors, and projects supporting positive health outcomes. This mobilization is expressed through the promotion, support, and delivery of motivational and informational health messages which convey consistent ideas, themes, and images. There are two fundamental bases of the Community Mobilization Framework. The first is its characterization of the variety of individual, social, and organizational roles and relationships in the community that might be used in a concerted campaign for HIV prevention for women. The second basis of the model is the description of the nature and extent of the involvement, which includes a continuum of involvement, ranging from simple endorsement to building active coalitions around a health initiative. The paper discusses practical methods of applying these principles, with the Women and Infants Demonstration Projects providing concrete examples.

[A rare cause of severe diarrhea in children: pseudomembranous colitis]

BACKGROUND

Pseudomembranous colitis is a rare and serious complication of treatment by antibiotics. The case of a patient with a protracted pseudomembranous colitis followed by two relapses is reported.

CASE REPORT

A 4 year-old boy was admitted after 18 days of profuse and feverish diarrhea. He had been given amoxycillin for 10 days, one and a half months previously. His temperature was 40 degrees C; he had abdominal pain and leucocytosis was 30,000/mm3. The situation rapidly improved with digestive rest and i.v. antibiotic therapy. Relapse of diarrhea together with bilious vomiting and acute abdominal pains required readmission three days after his discharge. Search for Clostridium difficile in stools remained negative. The diagnosis of pseudomembranous colitis was confirmed by sigmoidoscopy and intestinal biopsy. The patient was given parenteral nutrition for 3 weeks and vancomycin. The disease was complicated by anasarca related to severe protein-loosing enteropathy but evolution was finally favourable after a two month period.

CONCLUSION

Pseudomembranous colitis remains a serious affection in childhood; its prognosis largely depends on the precocity of diagnosis and treatment.

Sclerotherapy with or without octreotide for acute variceal bleeding

BACKGROUND

Sclerotherapy is considered the most effective way to stop bleeding from esophageal varices, but acute variceal bleeding is still associated with a high risk of rebleeding and death. We compared sclerotherapy alone with sclerotherapy and octreotide to control acute variceal bleeding and prevent early rebleeding in patients with cirrhosis.

METHODS

In a double-blind, prospective trial, 199 patients with cirrhosis and acute variceal bleeding who underwent emergency sclerotherapy were randomly assigned to receive a continuous infusion of octreotide (25 micrograms per hour) or placebo for five days. The primary outcome measure was survival without rebleeding five days after sclerotherapy.

RESULTS

After five days, the proportion of patients who had survived without rebleeding was higher in the octreotide group (85 of 98 patients, or 87 percent) than in the placebo group (72 of 101, or 71 percent; 95 percent confidence interval for the difference, 4 to 27 percent; P = 0.009). The mean number of units of blood transfused within the first 24 hours after sclerotherapy was lower in the octreotide group (1.2 units; range, 0 to 7) than in the placebo group (2.0 units; range, 0 to 10; P = 0.006). A logistic-regression analysis showed that the treatment assignment (P = 0.003) and the number of blood units transfused before any other treatment was undertaken (P = 0.002) were the only two variables independently associated with survival without rebleeding. After adjustment for base-line differences between the two groups, the odds ratio for treatment failure in the placebo group, as compared with the octreotide group, was 3.3 (95 percent confidence interval, 1.5 to 7.3). The mean (+/- SD) 15-day cumulative survival rate (estimated by the Kaplan-Meier method) was 88 +/- 12 percent in both groups. Side effects were minor, and their incidence was similar in the two groups.

CONCLUSIONS

In patients with cirrhosis, the combination of sclerotherapy and octreotide is more effective than sclerotherapy alone in controlling acute variceal bleeding, but there is no difference between the overall mortality rates associated with the two approaches to treatment.

Prevention of recurrent variceal bleeding in alcoholic cirrhotic patients: prospective controlled trial of propranolol and sclerotherapy

We conducted a prospective randomized controlled study to evaluate the effectiveness of propranolol and sclerotherapy, compared to a control group, in the prevention of variceal rebleeding in alcoholic cirrhotic patients. Among the 79 patients included, the distribution of patients according to Child-Pugh classification was: A, 22%; B, 40%; and C, 38%. Propranolol was given twice daily with a mean final dose of 54 +/- 16 mg/day, this resulted in a mean reduction in resting heart rate of 26 +/- 7%. Sclerotherapy was performed weekly using 1% polidocanol. End points were rebleeding or death. During the mean follow up of 19 +/- 16 months, 43 patients bled and 22 patients died. The cumulative percentages of patients free of rebleeding at 1 year were: propranolol, 81% (95% confidence interval (CI): 63-92); sclerotherapy, 64% (95% CI: 45-82); control, 54% (95% CI: 36-71); these differences did not reach statistical significance. The cumulative percentages of patients alive at 1 year were: propranolol, 92% (95% CI: 76-98); sclerotherapy, 79% (95% CI: 58-91); control, 81% (95% CI: 60-93); these differences were not statistically significant. Alcohol withdrawal, which occurred in 66% of patients, was an independent predictive factor associated with a decreased risk of rebleeding or death. In conclusion, a life table analysis of patients free of rebleeding, as well as of patients surviving, revealed a tendency in favour of propranolol. The lack of a statistical support for these two favorable effects could be due to poor statistical power.(ABSTRACT TRUNCATED AT 250 WORDS)

Pancreas divisum and pancreatitis: a coincidental association?

The aim of the present study is to assess the frequency of pancreas divisum and the features of patients with pancreas divisum in order to assess the role of this anomaly in the occurrence of pancreatitis. A total of 1049 endoscopic retrograde pancreatographies were studied between 1978 and 1988. Patients with pancreas divisum were studied in terms of their clinical findings and their disease (pancreatitis or not). Pancreas divisum was diagnosed in 62 patients (5.9%). No statistical differences with regard to age and sex were found between patients with and without pancreas divisum. The frequency of pancreas divisum was similar in the different groups of disease, especially chronic pancreatitis, acute pancreatitis, recurrent pancreatitis and idiopathic pancreatitis. The study of pancreatograms showed that dorsal ductal abnormalities alone were found as frequently as ventral alterations alone. Our results show that pancreas divisum cannot be directly implicated in the occurrence of pancreatitis, and should not prompt a systematic sphincterotomy of the accessory papilla. This treatment should only be considered in the rare cases of acute recurrent idiopathic pancreatitis with dorsal ductal dilatation and stenosis of the accessory papilla.

Severe hemorrhagic radiation proctitis advancing to gradual cessation with hyperbaric oxygen

We report a case of a male patient suffering from a severe hemorrhagic radiation proctitis which gradually ceased with hyperbaric oxygen. We discuss the mechanisms of chronic radiation injury and the effect of the hyperbaric oxygen. This therapy is proposed as an alternative to surgical intervention for this abnormality.

[Determination of the carcinoembryonic antigen and endoscopic sphincterectomy in papillomatosis of the bile ducts]

Two new cases of multiple biliary papillomatosis are reported. In these 2 cases, endoscopic retrograde cholangiography (CRE) was performed; the roentgen findings are described; the mucinous aspect of the bile, the important levels of biliary carcinoembryonic antigen and the intraductal biopsies after endoscopic sphincterotomy (E.S.) furnished precious aid for diagnosis; one E.S. was performed in the two cases allowing satisfactory drainage biliary; in one case, surgery and chemotherapy were associated; based on these two cases and 26 others of literature, management of the disease is discussed.

[Mixed carcinoid tumor-adenocarcinoma of the stomach. Review of the literature, apropos of a case]

We report a case of mixed tumor of the stomach with a double histological population: carcinoid and adenocarcinoma. The carcinoid component presented an usual morphological pattern with "atypical" elements, and without argyrophilic cells; the carcinoid cells were exclusively marked by an anti-serotonin serum. The other component was a poorly differentiated carcinoma, with muco secretion, which was not marked by and anti-carcino-embryonic antigen serum. The limit between the two components was sharp. The association of mucin in the carcinoma and serotonin in the carcinoid component was an argument in favour of the diagnosis of mixed tumor carcinoid-adenocarcinoma (composite tumor) of the stomach. The evolution after operation leaded to a local recurrence and to the death 10 months later, in spite of chemotherapy. The existence of composite tumors raises nosological, histogenetical and diagnostic problems, which are discussed in this work. The prognosis of these tumors is unknown and therapeutic possibilities seem to be scanty.