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B Person

Publications and source records attributed to B Person.

At least 19 recordsLinked to original sources

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.

Binding Sites

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.

Adult

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.

Adult

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.

Adolescent

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.

Adult

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.

Down-Regulation

[Treatment of common bile duct lithiasis: first-line endoscopic sphincterotomy and celioscopic cholecystectomy].

The aim of this study was to assess retrograd cholangiogram findings and first-line endoscopic sphincterotomy followed by laparoscopic cholecystectomy for the treatment of main bile duct lithiasis. Clinical, biological and echographic criteria predictive of main bile duct lithiasis were observed in 125 patients (32 men, 93 women, mean age 44.2 years) who underwent retrograde cholangiography. Results suggested lithiasis of the main bile duct in 105 case (87.5%) and were confirmed at endoscopic sphincterotomy in 99. There were no deaths; four complications occurred (3 moderate cases of pancreatitis, 1 cholecystitis). Conversion was required in 11.6%, usually because of difficulties in dissecting. No residual lithiasis was observed. Mean duration of hospitalization was 11.4 days. This sequential treatment scheme for main bile duct lithiasis appears to be effective, minimally invasive and safe.

Adult

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.

Endoscopy, Gastrointestinal

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.

Acquired Immunodeficiency Syndrome

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.

Acute Disease

[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.

Anti-Bacterial Agents

[Lansoprazole versus ranitidine in the prevention of early recurrences of digestive hemorrhages from gastroduodenal ulcers. Randomized double-blind multicenter study].

Strong inhibition of acid secretion could be able to decrease gastric and duodenal ulcer early rebleeding. OBJECTIVE--The aim of this double blind randomized trial was to compare early rebleeding rates of 2 groups of patients treated with ranitidine (600 mg/day) or lansoprazole (60 mg/day) per os for 6 consecutive days. METHODS--Seventy five patients with a high risk of rebleeding (clinical and endoscopical criteria) were included in this trial. These ulcers were Ia (n = 10), Ib (n = 20), IIa (n = 13), IIb (n = 32) in Forrest classification. RESULTS--Nineteen out of 75 patients rebled (25.3%): 11 out of 37 (30%) and 8 out of 38 (21%) in the ranitidine and lansoprazole groups respectively. Rates of rebleeding were 10%, 12.5%, 36% and 29% respectively in the ulcers grade Ia (previously treated with endoscopic sclerosis), Ib, IIa and IIb in the Forest classification. CONCLUSION--The rates of rebleeding were not statistically different in the 2 groups of treatment. The high rebleeding rates observed with Forrest IIa and IIb and duodenal ulcers support the need of haemostatic endoscopic therapy associated to antisecretory treatment in such patients.

2-Pyridinylmethylsulfinylbenzimidazoles

[Predictive factors of response to chemotherapy in epidermoid cancer of the esophagus. Study apropos of 60 patients and evaluation of a response score].

The aim of this study was to select predictive factors for response to chemotherapy in esophageal squamous cell carcinoma. Sixty patients, aged between 39 and 77 years (mean 61.5) received two initial chemotherapy sessions of 5 FU (1 mg/m2/24 h) and cisplatinum (20 mg/m2/24 h) during four days. Sixteen clinical, endoscopic, biological, and histological factors were collected. The response to chemotherapy was evaluated one month after completion of the second session by means of endoscopic and computed tomographic data. Thirty-two percent (CI: 20-44 percent) of patients had an objective response to chemotherapy (according to WHO criteria). Univariate analysis showed two predictive factors: obstructing pattern of tumor (P less than 0.01) and albuminemia less than 35 g/l (P less than 0.01). A response score was calculated with a stepwise regression model. The score correctly predicted a satisfactory response to chemotherapy with a sensitivity and specificity of 84.2 and 73 percent, respectively. Overall survival of these patients was statistically higher (P less than 0.001) compared with patients without any response. A satisfactory response to chemotherapy in patients with esophageal squamous cell carcinoma can be expected according to certain pretreatment factors.

Aged