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Biomedical subjects

Jacob Yahav

Publications and source records attributed to Jacob Yahav.

15 recordsLinked to original sources
PubMed2007

Elevated 13C urea breath test values females infected with Helicobacter pylori.

(13)C-urea breath test (UBT) for the diagnosis of Helicobacter pylori requires a high density and active bacteria and has the potential to provide a noninvasive index of bacterial growth. We describe the gender differences in delta over baseline (13)C-UBT values in 7373 patients (4531 females and 2842 males) who underwent (13)C-UBT test for the diagnosis of H. pylori infection. A significantly (P<.001) higher mean +/- SD excess delta (13)CO(2) excretion was recorded in females (24.7+/-17.4) compared to males (17.6+/-11.8) aged 10-80 years. The age-adjusted difference between sexes was 7.1 (95% confidence interval, 6.4-7.9). Our analysis demonstrates quantitatively for the first time gender associated differences in H. pylori host interaction. This study suggests that infected females have a higher bacterial load and therefore may potentially infect their children at a higher degree than males.

Adolescent↗
PubMed2006

Helicobacter pylori and Clostridium difficile in cystic fibrosis patients.

We describe the prevalence of H. pylori and toxigenic Clostridium difficile (CD) infection and its relationship with gastrointestinal symptoms and pancreatic sufficiency (PS) or insufficiency (PI) in cystic fibrosis (CF) patients. Stool specimens from 30 consecutive patients with CF, aged 1-44, and from 30 healthy similarly aged subjects were tested for the H. pylori antigen by specific monoclonal antibodies and for CD toxins by Tox A/B assay and Tox A assay. CF patients were assessed clinically and tested for specific H. pylori serum antibodies and for mutations. In CF patients, the prevalence of H. pylori antigen was 16.6% (5/30), compared to 30% (9/30) in controls. Of the 26 CF patients with PI, only 2 (7.6%) were infected by H. pylori, compared with 3 of the 4 (75%) patients with PS (P=0.001). H. pylori infection was diagnosed in 3 of 5 (60%) CF patients carrying mild mutations, compared to 1 of 25 (4%) CF patients carrying severe mutations (P=0.01). Fourteen of 30 (46.6%) stool specimens from CF patients tested positive in the ToxA/B assay, and 3 of 14 tested positive for ToxA. No significant differences in antibiotic use, severity of lung disease, PI, chronic abdominal pain, or genotype were found between the two groups. None of the controls was positive for CD toxins. Prevalence of H. pylori infection in CF patients was lower than in similarly aged non-CF controls. CF patients with PI or a history of distal intestinal obstruction syndrome and those carrying mutations associated with a severe phenotype were protected against H. pylori infection. Almost half of the CF patients were asymptomatic carriers of CD producing mostly toxin B. More studies are needed to confirm our results in a larger group of CF patients.

Adolescent↗
PubMed2006

Susceptibility-guided vs. empiric retreatment of Helicobacter pylori infection after treatment failure.

Successful eradication of Helicobacter pylori after failure of standard triple therapy is difficult because of the higher resistance to metronidazole and clarithromycin. We evaluated the efficacy of susceptibility-guided vs. empiric retreatment for H. pylori after at least one treatment failure and determined the prevalence of posttreatment antibiotic resistance. Forty-nine patients in whom at least one treatment regimen for H. pylori eradication had failed underwent gastric biopsy and culture and were retreated according to the in vitro susceptibility results. Findings were compared with those for 49 control patients referred to our center for a (13)C-urea breath test. H. pylori eradication was assessed by urea breath test at least 6 weeks after retreatment in both groups. Susceptibility-guided retreatment was associated with better eradication rates than empiric treatment. The difference remained significant in stratified and multivariate analysis. Susceptibility-guided retreatment appears to be significantly more effective than empiric retreatment in eradicating H. pylori after at least one previous treatment failure.

Anti-Bacterial Agents↗
PubMed2006

In vitro activity of levofloxacin against Helicobacter pylori isolates from patients after treatment failure.

We tested the in vitro activity of levofloxacin (LEV), amoxicillin (AMP), clarithromycin (CLA), metronidazole (MET), and tetracycline (TET) against 70 clinical isolates of Helicobacter pylori recovered from 70 dyspeptic patients. All patients had previously failed 2 treatment regimens: first-line triple therapy with omeprazole, AMP, and CLA, and second-line quadruple therapy with omeprazole, MET, TET, and bismuth. Resistance to CLA, MET, and LEV was found in 65.7%, 57.1%, and 18.6% of isolates, respectively. Resistance to both CLA and MET was found in 32.8%, and to CLA, MET, and LEV in 12.8%. Only 4 of the isolates were resistant to both CLA and LEV, and none was resistant to LEV alone or to MET and LEV. Physicians should consider triple therapy with omeprazole, LEV, and AMP in patients unsuccessfully treated with first- and second-line regimens.

Anti-Bacterial Agents↗
PubMed2005

Helicobacter pylori infection in pediatrics.

The diagnosis of Helicobacter pylori infection continues to challenge practicing physicians around the world. In the last year, several reports from Africa tried to examine the epidemiology of H. pylori infection in nursing babies, while others investigated the association between recurrent abdominal pain symptoms and H. pylori. In the diagnostic arena, attempts were made to improve diagnostic accuracy, mainly by using a new monoclonal version of the stool antigen test, and by applying the urea breath test in smaller children. In the current report, the most important studies on H. pylori infection in children published in the last year are also reviewed.

Child↗
PubMed2004

Association of CagA+ Helicobacter pylori infection with aortic atheroma.

BACKGROUND: To investigate possible association between infection with CagA(+) strains of Helicobacter pylori and aortic atheroma diagnosed by transesophageal echocardiography. METHODS AND RESULTS: One hundred and eighty-eight consecutive subjects prospectively examined for presence of aortic atheroma (localized intimal thickening of >/=3mm) by transesophageal echocardiography were tested for serum IgG antibodies against H. pylori (enzyme-linked immunosorbent assay) and CagA protein (Western blot assay). The association between infection with H. pylori, CagA status of the infecting H. pylori strains, and aortic atherosclerosis was evaluated after adjusting for coronary artery disease risk factors. There was a linear trend for presence of atheroma in subjects with CagA-positive H. pylori infection (51/81, 63%) compared to subjects with CagA-negative H. pylori infection (21/45, 46.7%) and uninfected subjects (18/62, 29%) (p=0.003). H. pylori seropositivity was not associated with aortic atheroma (OR 2.9; 95% CI, 0.8-10.3; p=0.11) when CagA status is not taken into account. On multivariate analysis, parameters associated with risk of aortic atheroma were CagA-positive H. pylori seropositivity (OR 4.4; 95% CI, 1.4-14.7; p=0.01), older age (OR 1.2; 95% CI, 0.9-14.7; p=0.01), having ever smoked cigarettes (OR 3.6; 95% CI, 1.3-10.0; p<0.001), and elevated serum triglyceride level (OR 3.4; 95% CI, 1.3-9.4; p=0.02). CONCLUSIONS: After controlling for H. pylori infection and coronary artery disease risk factors, infection with a CagA-positive strain of H. pylori was independently associated with aortic atherosclerosis. This study suggests a gradient of atherosclerosis between uninfected individuals and patients with CagA-positive H. pylori infection and should prompt research into the role of CagA-positive H. pylori infection in the inflammatory atherosclerotic process.

Aged↗
PubMed2004

Susceptibility of Helicobacter pylori isolates to the antiadhesion activity of a high-molecular-weight constituent of cranberry.

The sensitivity of a large number of antibiotic-resistant and nonresistant Helicobacter pylori isolates to the antiadhesion effect of a high-molecular-mass, nondialysable constituent of cranberry juice was tested. Confluent monolayers of gastric cell line in microtiter plate wells were exposed to bacterial suspensions prepared from 83 H. pylori isolates from antibiotic-treated and untreated patients in the presence and absence of the cranberry constituent. Urease assay was used to calculate the percentage of adhesion inhibition. In two thirds of the isolates, adhesion to the gastric cells was inhibited by 0.2 mg/mL of the nondialysable material. There was no relationship between the antiadhesion effect of the cranberry material and metronidazole resistance in isolates from either treated or untreated patients (N=35). Only 13 isolates (16%) were resistant to both the nondialysable material and metronidazole, and 30 (36%) were resistant to the nondialysable material alone. There was no cross-resistance to the nondialysable material and metronidazole. These data suggest that a combination of antibiotics and a cranberry preparation may improve H. pylori eradication.

Amoxicillin↗
PubMed2004

Association of Helicobacter pylori infection with Shigella gastroenteritis in young children.

OBJECTIVE: Helicobacter pylori infection is acquired mainly in early childhood. Much is unknown about the mode of transmission. The organism can be cultivated from cathartic stools and vomitus and is potentially transmissible during episodes of gastrointestinal tract illness. Because Shigella and Salmonella are common pathogens in enteric infections in children, we examined the association of H. pylori with Shigella and Salmonella infections in pediatric patients. METHODS: The study population included consecutive children aged 2-72 months hospitalized with acute gastroenteritis who had culture-proven shigellosis (N = 78) or salmonellosis (N = 76). Sixty-five healthy similarly aged children with culture-negative stools served as controls. Parents of cases were queried for personal and family characteristics and socioeconomic indicators. The stool specimens from all participants were tested for H. pylori antigen. RESULTS: On univariate analysis, Shigella gastroenteritis was significantly associated with H. pylori positivity (odds ratio, OR: 3.5, 95% confidence interval (CI): 1.5-8.8, p= 0.004) compared to controls. This association remained significant even after adjusting for living conditions, father's occupation, and father's education (OR = 3.38, 95% CI: 1.39-8.22, p= 0.007). Salmonella gastroenteritis was not associated with H. pylori positivity (OR = 1.1; 95% CI: 0.4-3.0, p= 0.8). CONCLUSION: H. pylori infection in young children is associated with Shigella gastroenteritis. This association warrants further investigation.

Acute Disease↗
PubMed2003

Influence of a merger on nurses' emotional well-being: the importance of self-efficacy and emotional reactivity.

The influence of the merger of two major medical centres on the emotional well-being of nurses was investigated by use of a questionnaire on emotional distress, perception of threat, self-efficacy and emotional reactivity. Evaluations were carried out 1 month prior to the merger at the official announcement, and again half a year after the merger took place. Before the merger, threat perception was higher in the transferring nurses, but the difference was of borderline significance (P = 0.05). There was a significant positive correlation between threat perception and both emotional reactivity and emotional distress, and a significant negative correlation between self-efficacy and both threat perception and emotional distress (P < 0.001 for all). After the merger, the transferring nurses showed more emotional distress (P = 0.009). There was a significant positive correlation between threat perception, emotional distress and negative outcome variables such as burnout and stress (P < 0.001), and a significant negative correlation between threat perception and positive outcome variables such as growth (P < 0.01). This study identifies some personal characteristics that can affect the way nurses deal with hospital mergers and need to be considered during organizational changes in order to maintain job satisfaction.

Adaptation, Psychological↗
PubMed2003

Seven-year study of bacteremia in hospitalized patients on chronic hemodialysis in a single tertiary hospital.

Sixty-seven hospitalized bacteremic patients on chronic hemodialysis were matched with 134 bacteremic controls. Mortality (25% and 28% respectively) was unrelated to dialysis. Predictors of mortality were: advanced age, decreased functional capacity, and malignancies. Most common organisms recovered were Staphylococcus aureus (30%), coagulase negative Staphylococcus (15%), and polymicrobial agents (15%).

Adolescent↗
PubMed2003

Liver cirrhosis and portal hypertension in cystic fibrosis.

OBJECTIVES: Liver disease is the second cause of death in cystic fibrosis. The most deleterious complication of liver disease is portal hypertension, which has an estimated prevalence of up to 8%. Portal hypertension may manifest itself by splenomegaly, hypersplenism, gastro-oesophageal bleeding and ascites. The aim of our study was to determine the prevalence, risk factors and invasive management of portal hypertension at our centre. METHODS: One hundred and fifty patients with cystic fibrosis were followed up between 1975 and 2000 in the national cystic fibrosis centre in Israel. Forty patients (27%) had liver disease. All underwent clinical evaluation and laboratory and imaging studies. RESULTS: Portal hypertension was diagnosed in 10 patients (7%), of whom eight were male. The mean age at diagnosis was 11 years (range, 4-17 years). All had severe mutations of the cystic fibrosis transmembrane conductance regulator gene (the CFTR gene), pancreatic insufficiency, meconium ileus or distal intestinal obstruction syndrome and variceal bleeding. Seven patients underwent sclerotherapy to control acute bleeding. Four underwent portosystemic shunting (functioning up to 37 years). Two patients with severe lung and liver disease underwent transjugular intrahepatic portosystemic shunting, which provided bleeding control, but both died while waiting for lung/liver transplantation. One patient underwent liver transplantation due to liver failure and still had good liver and lung function 10 years later. CONCLUSIONS: Portal hypertension is more common among Israeli patients with cystic fibrosis. The unique genetic composition of our population may explain this phenomenon. Risk factors include male gender, pancreatic insufficiency, severe CFTR mutations, meconium ileus and meconium ileus equivalent. Sclerotherapy is the main option to control oesophageal variceal bleeding, while portosystemic shunts offer a prolonged alternative treatment for refractory bleeding. A transjugular intrahepatic portosystemic shunt and liver transplantation may also be effective, but further research is required in order to establish their role.

Adolescent↗
PubMed2003

Dyspepsia symptoms and Helicobacter pylori infection, Nakuru, Kenya.

The prevalence of Helicobacter pylori infection was studied in 138 patients with dyspepsia in a hospital in Nakuru, Kenya, and in 138 asymptomatic sex- and age-matched controls from the same population. Anti-H. pylori immunoglobulin (Ig) G was more prevalent in dyspeptic than asymptomatic persons (71% vs. 51%), particularly those <30 years old (71% vs. 38%). H. pylori seropositivity was associated with dyspepsia after adjusting for age, sex, and residence (urban or rural). Among adults, the association between H. pylori infection and dyspepsia remained after adjusting for the above factors and for educational attainment, family size, and manual occupation. H. pylori infection in asymptomatic residents of Nakuru, Kenya, was more prevalent in older persons, with a rate of 68%, than in those 31-40 years of age. However, young persons with dyspepsia had an unexpectedly high prevalence of H. pylori infection. H. pylori test-and-treat strategy should be considered in Kenyan patients with dyspepsia, particularly in persons <30 years of age.

Adolescent↗
PubMed2002

Resistance of Helicobacter pylori isolated in Israel to metronidazole, clarithromycin, tetracycline, amoxicillin and cefixime.

The resistance of Helicobacter pylori isolated in Israel to metronidazole, clarithromycin, tetracycline, amoxicillin and cefixime was tested in 138 isolates, including 28 from treatment failures. No resistance to tetracycline was detected. Resistance to amoxicillin was found in one isolate (MIC = 1.5 mg/L) from an untreated patient, and resistance to cefixime in two isolates from each group (P = 0.18). Resistance to metronidazole and clarithromycin was much higher in the isolates from treated than from untreated patients: 60.7% and 38.2% for metronidazole (MIC >or= 8 mg/L) (P = 0.03); 46.4% and 8.2% for clarithromycin (MIC >or= 2 mg/L) (P < 0.001). Therapeutic outcome would benefit from susceptibility testing, especially after treatment failure.

Amoxicillin↗
PubMed2002

Effects of an intensive 4-week summer camp on cystic fibrosis: pulmonary function, exercise tolerance, and nutrition.

STUDY OBJECTIVES: Cystic fibrosis (CF) patients prefer exercise to most other forms of therapy, although objective improvement remains controversial. Israeli CF patients have attended a summer program in Switzerland for many years with subjective improvement. However, CF camps worldwide have been cancelled recently, due to fears of cross-infection with resistant organisms. Therefore, we evaluated the effect of attending the camp on pulmonary function, exercise tolerance, and nutritional state in CF patients. DESIGN: Weight, resting pulmonary function, incremental exercise test results, and sputum culture findings were assessed before and after a 4-week intensive summer camp. SETTING: Davos, Switzerland (altitude, 1,500 m). PATIENTS: Thirteen Israeli CF patients (seven women and six men) with an age range of 9 to 25 years who had mild-to-moderate lung disease. No patients had Burkholderia cepacia detected in their sputum. INTERVENTIONS: The program included a high-calorie diet, chest physiotherapy, daily mountain climbing, and indoor activities. Arterial oxygen saturation (SaO(2)) was maintained at > 88% during exertion. RESULTS: Exercise tolerance improved significantly. The peak work capacity increased by 12.7%, the maximal oxygen uptake increased by 10%, and minute ventilation increased by 18.5% (p < 0.0005). Of the calculated parameters, the anaerobic threshold improved by 17%. Ventilation was always the limiting factor during exercise, although it improved. There was no significant change in resting lung function and pulse or in SaO(2) decline at maximal exercise. The mean weight gain was 1 kg. No patient acquired B cepacia. CONCLUSIONS: An intensive summer camp improved exercise tolerance and nutrition in CF patients. This may explain improved patient well-being despite unchanged values for resting lung function. The reinstitution of summer camps, with special care to avoid cross-infection, should be considered.

Adolescent↗