Biomedical subjects

Zmira Samra

Publications and source records attributed to Zmira Samra.

At least 19 recordsLinked to original sources

PubMed2004

Role of cytokine gene polymorphism and hepatic transforming growth factor beta1 expression in recurrent hepatitis C after liver transplantation.

Recurrent hepatitis C virus (HCV) infection after orthotopic liver transplantation (OLT) is nearly universal. Cytokines play an important role in the immune response to viral infection, and cytokine gene polymorphism affects the overall expression and secretion of cytokines. The objective of this study was to define the relationship between cytokine polymorphism and recurrent hepatitis C after OLT. Blood samples were collected from 36 patients at a mean of 44.6+/-30.4 months after OLT for chronic HCV infection. DNA was extracted from peripheral blood mononuclear cells, and polymerase chain reaction-sequence specific primers (PCR-SSP) analysis was performed on promoter sequences of transforming growth factor beta1 (TGF-beta1), interleukin 6 (IL-6) interleukin 10 (IL-10), tumor necrosis factor alpha (TNF-alpha) and interferon gamma (INF-gamma). Liver biopsies performed at diagnosis of recurrent disease were graded with the Knodell score, and hepatic TGF-beta1 expression was determined semiquantitatively by immunohistochemistry. The gene polymorphism of TGF-beta1 was correlated with its expression on hepatocytes and sinusoids. Polymorphism in all studied cytokine genes was correlated with recurrence, and interval to recurrence (>12 or < or =12 months post-OLT), and clinical (ascites, Child-Pugh score and death), biochemical parameters of recurrent HCV (serum alanine aminotransferase (ALT)), INR, albumin, bilirubin), and virological parameters (HCV genotype and load). Biopsies revealed recurrent HCV in 31 patients (86.1%); in 21 (67.7%), the interval to recurrence was 12 months. There was a statistically significant correlation between TGF-beta1 gene polymorphism, i.e., the genetic ability to produce high levels of TGF-beta1, and the intensity of TGF-beta1 staining on hepatocytes (p=0.003) and sinusoids (p=0.003), and the degree of fibrosis (p=0.02). A borderline correlation was found with the presence of ascites (p=0.007), but not with Child-Pugh score, synthetic liver function tests or HCV genotype and load. The genetic ability to produce low levels of IFN-gamma was correlated with recurrent disease (p=0.015). No such correlation was found for TGF-beta1 gene polymorphism. In conclusion, polymorphism in the TGF-beta1 gene correlates with its in situ hepatic expression in patients with recurrent HCV after liver transplantation. INF-gamma, but not TGF-beta1 gene polymorphism, correlates with early recurrent hepatitis C after transplantation. These findings might help to design preemptive prevention therapy in selected patients at risk.

Cohort Studies↗

PubMed2004

Optimal detection of Staphylococcus aureus from clinical specimens using a new chromogenic medium.

The new chromogenic medium CHROMagar Staph aureus (CASA) was evaluated for its ability to detect and presumptively identify Staphylococcus aureus. Nine hundred forty-two clinical specimens (742 wound, 200 sputum and bronchoalveolar lavage) were cultured on CASA, tryptic soy blood agar (TSBA), and mannitol salt agar (MSA). Of the 153 S. aureus isolates from wounds on any media, 151 grew on CASA and TSBA and 146 on MSA. Sensitivity after 24 hours was 93.5%, 94%, and 77%, respectively, and increased after 48 hours to 99% for CASA and TSBA and to 95% for MSA. Of the 41 isolates recovered from sputum and lavage, all grew on CASA, 27 on TSBA, and 36 on MSA. Sensitivity after 24 hours was 93%, 66%, and 81%, respectively, and 100%, 66%, and 88% after 48 hours. All specimens revealed 99% sensitivity for CASA, 92% for TSBA, and 94% for MSA. Specificity for CASA was 100%. Antimicrobial susceptibility tests showed full agreement between isolates from CASA and from reference media. In conclusion, CASA has a high sensitivity and can identify isolates undetected on conventional media (p value for CASA vs. TSBA was 0.001 and vs. MSA, 0.006). This difference is particularly notable when mixed flora are present. The simplicity of the colony recognition increased the medium specificity, allowing a reliable and rapid method for the detection of S. aureus on the primary plate.

Agar↗

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↗

PubMed2004

Adenovirus infection in hospitalized immunocompetent children.

This study investigated the clinical features of immunocompetent children with adenovirus infection requiring hospitalization. The files of 78 children (mean age 17 +/- 10 months) with community-acquired adenovirus infection admitted over a 2-year period were reviewed. The children were referred after 5.7 +/- 3.4 days of illness, all with fever (mean peak 39.8 +/- 0.8 degrees C). Temperature normalized after 3.5 +/- 2 days. Duration of hospitalization (mean, 7.0 +/- 3.9 days) correlated with lethargy, lung crackles, cracked lips, hypoxia, impaired liver tests, and high serum lactic dehydrogenase (LDH) concentration at admission. Serum LDH concentrations and hypoxemia predicted 70% of the variance in hospital stay. All patients recovered. Adenovirus infection may cause considerable morbidity, even in immunocompetent children. Disease severity, defined by duration of hospitalization, correlates with serum LDH concentrations and oxygen saturation at admission.

Adenovirus Infections, Human↗

PubMed2003

Use of the NOW Streptococcus pneumoniae urinary antigen test in cerebrospinal fluid for rapid diagnosis of pneumococcal meningitis.

Streptococcus pneumoniae is one of the most common pathogens in bacterial meningitis. Rapid diagnosis is critical for effective treatment. The aim of this study was to assess the accuracy of the NOW S. pneumoniae Urinary Antigen Test, (Binax, Portland, ME, USA) originally developed for urine testing, in detecting the S. pneumoniae antigen in cerebrospinal fluid (CSF). The study included 519 patients with suspected meningitis. CSF, blood and urine samples were cultured according to standard methods. CSF viral culture was also performed. CSF and urine specimens were tested for pneumococcal antigen with the NOW S. pneumoniae test.S. pneumoniae was isolated from the CSF of 22 patients. The direct antigen test was positive in CSF in 21/22 patients (95.4% sensitivity), and in urine, in 12/21 (57.1% sensitivity). Direct CSF smear was positive in 15/22 (68% sensitivity). CSF samples that cultured negative for S. pneumoniae (n = 470) or positive for other bacteria (n = 27) were also negative on the NOW test (100% specificity). By contrast, urine samples of 63/470 of patients with negative CSF culture were positive on the NOW test, as were 5/27 urine samples of patients with CSF culture positive for other bacteria (p = 0.45). The NOW S. pneumoniae antigen test in CSF yields a rapid and very reliable diagnosis of pneumococcal meningitis, enabling prompt and adequate treatment. Its low sensitivity in urine indicates that this mode of testing is not useful for the diagnosis of pneumococcal meningitis. These data have been included in the FDA application for approval of the NOW test for use in the CSF for the diagnosis of pneumococcal meningitis.

Adolescent↗

PubMed2003

Ill from eel?

Explore the source record for details and available documents.

Adult↗

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

Growing antimicrobial resistance of Shigella isolates.

Appropriate antibiotic treatment of shigellosis depends on identifying resistance patterns. By studying Shigella isolates in central Israel from 1998 to 2000, and comparing with the period 1991-1992, we identified a significantly increased resistance to tetracycline (from 23% to 87%, P < 0.00001), high resistance to trimethoprim-sulfamethoxazole (94%) and ampicillin (85%) and emerging resistance to quinolones (0.5-2%). These data mandate local monitoring of resistance and its consideration in empirical therapy.

Adult↗

PubMed2003

Herpes simplex virus type 1 is the prevailing cause of genital herpes in the Tel Aviv area, Israel.

BACKGROUND AND GOAL: The changing epidemiology of genital herpes with the increasing importance of herpes simplex virus (HSV) type 1 prompted a study on the relative prevalence of HSV-1 and HSV-2 among cases of genital herpes in the Tel Aviv area, Israel. STUDY DESIGN: A retrospective laboratory-based study of positive genital and nongenital herpes cultures performed at the Beilinson Medical Center between 1993 and 2002. Data regarding the number of isolates of each type and the age and sex of patients with genital lesions were retrieved from the database. Cultures were performed using Vero cells, and positive results were confirmed and typed by immunofluorescence. RESULTS: A total of 285 positive genital cultures and 659 positive nongenital cultures were recorded. HSV-1 was identified in 189 (66.3%) of the positive genital specimens and in 656 (99.55%) of the nongenital specimens. HSV-1 was isolated in 174 of 262 (66.4%) female subjects and 15 of 23 (65.2%) male subjects. The proportion of HSV-1 genital isolates was 72.7% in patients 15 to 24 years of age, 62% in those 25 to 44 years, and 46% in those aged 45 years or older. Overall, the annual isolation rate of genital HSV-1 has not changed markedly over the years. CONCLUSION: Herpes simplex virus type 1 has clearly been the predominant HSV type isolated from genital specimens in the Tel Aviv area over the last decade.

Adolescent↗

PubMed2003

Prevalence and risk factors for herpes simplex virus type 2 infection among pregnant women in Israel.

BACKGROUND: Although usually a nuisance to the adult patient, herpes simplex virus type 2 (HSV-2) infection can have devastating consequences on the infected newborn. It is thus important to document the prevalence and risk factors of this infection among pregnant women in a defined population. The availability of the new type-specific assays that provide accurate serologic results prompted us to study the seroprevalence of HSV-2 infection among pregnant women in Israel. STUDY DESIGN: In a cross-sectional descriptive study, 512 pregnant women were tested. The study population included Israeli-born Jewish and Arab women, and new immigrants from the former Soviet Union. A competition-based enzyme-linked immunosorbent assay (ELISA) was used to detect type-specific HSV-1 and HSV-2 antibodies. Univariate and multivariate analyses were performed to identify risk factors for HSV-2 seropositivity. RESULTS: The prevalence of HSV-2 infection was 13.3% (95% confidence interval, 10.5-16.5%) and that of HSV-1 was 94.9%. History of genital or labial herpes was reported by 1.3% and 26.8% of the participants, respectively. The HSV-2 infection rate was 3-fold higher among immigrants from the former Soviet Union (27.5%) than among Israeli-born Jewish and Arab women (9%). The only risk factor independently associated with HSV-2 seropositivity was multiple lifetime sexual partners. CONCLUSION: We have documented a relatively low seroprevalence of HSV-2 infection in a demographically mixed group of pregnant women in Israel. The role of high-risk sexual behavior in the spread of the infection has been reconfirmed.

Adolescent↗

PubMed2003

Genotypic and phenotypic resistance: longitudinal and sequential analysis of hepatitis B virus polymerase mutations in patients with lamivudine resistance after liver transplantation.

OBJECTIVE: Lamivudine-resistant strains appear in 27-62.5% of liver transplant recipients treated with lamivudine for hepatitis B virus (HBV) recurrence, and may lead to failure of antiviral therapy. In an extension of our previous study, we investigated the molecular events associated with the emergence of lamivudine-resistant mutants in this population. METHODS: Sequential serum samples from 10 consecutive patients with lamivudine resistance after liver transplantation were analyzed for viral genotype, precore mutants, and viral polymerase gene mutants (L528M, M552V, M552I) using restriction fragment length polymorphism. Quantitative analysis of HBV DNA was performed using hybridization assay and polymerase chain reaction. RESULTS: Eight patients (80%) were infected with genotype D and two (20%) with genotype C. Polymerase mutants (genotypic resistance) were identified in all the patients. Phenotypic resistance (rise in serum HBV DNA titers above the detection limit of the hybridization assay) developed in five patients (50%); of the remainder, three (30%) did not have phenotypic resistance, and two were primary nonresponders. Genotypic resistance was detected earlier than phenotypic resistance (median 285 days [range 42-510] vs median 387 days [range 320-420], p = 0.055). In five patients (50%), the emergence of the YMDD mutants took over the wild type; in three (30%), the YMDD mutant took over the wild type, but the wild type re-emerged during lamivudine therapy; and in two (20%), the YMDD mutants were detected in a mixture with the wild type (in different percentages). The mean pretreatment serum ALT level was significantly lower in the patients who did not develop phenotypic resistance (p = 0.0002). The M552I pure viral population was found mainly in these patients, and all retained stable graft function (median follow-up 33 months). A high pretreatment HBV DNA level (>50 x 10(6) copies/ml) was highly statistically significantly correlated with the rapid occurrence of phenotypic resistance (r = -0.90, p = 0.04). CONCLUSIONS: We reached the following conclusions: 1) In our area, liver transplant recipients who develop resistance to lamivudine given for recurrent HBV infection seem to be mainly infected with genotype D. 2) Re-emergence of the wild type can occur during lamivudine therapy. 3) Genotypic resistance precedes phenotypic resistance, although phenotypic resistance does not always follow genotypic resistance. 4) Quantitative determination of viremia and analysis of polymerase gene mutants are recommended for monitoring antiviral therapy of liver transplant patients with HBV reinfection in the graft.

Adult↗

PubMed2003

In vitro synergy of caspofungin and itraconazole against Aspergillus spp.: MIC versus minimal effective concentration end points.

Caspofungin and itraconazole were studied alone and in combination against 31 clinical isolates of Aspergillus spp. according to NCCLS M38-P guidelines. MICs and microscopic minimal effective concentrations (MECs) were recorded, and synergy was calculated by using both end points. Synergy or synergy to additivity was found in 30 of 31 isolates by using MIC end points. With MEC end points no synergy was found and indifference was detected in 26 of 31 strains.

Anti-Bacterial Agents↗

PubMed2003

Co-trimoxazole-sensitive, methicillin-resistant Staphylococcus aureus, Israel, 1988-1997.

Among bloodstream methicillin-resistant Staphylococcus aureus (MRSA) isolates from adult patients in a single hospital, susceptibility to co-trimoxazole increased progressively from 31% in 1988 to 92% in 1997 (p<0.0001). If also observed in other institutions, these findings should encourage the performance of a clinical trial of sufficient size to compare co-trimoxazole to vancomycin in treating MRSA infections.

Adult↗

PubMed2003

Vaginitis in a gynecologic practice in Israel: causes and risk factors.

BACKGROUND: Vaginal symptoms are a leading reason for a patient to visit her gynecologist. Little is known about the prevalence of the different causes of vaginitis and the risk factors for this entity in Israel. OBJECTIVE: To determine the prevalence of the main forms of vaginitis: vulvovaginal candidiasis, bacterial vaginosis, and trichomoniasis, in a gynecologic practice in Israel. METHODS: We evaluated 208 patients presenting with vaginal symptoms to a gynecologic clinic; 100 asymptomatic women who attended the clinic for routine check-up served as controls. Demographic, medical and gynecologic histories were obtained, and a pelvic examination was performed in all patients. Vaginal specimens were tested for pH and amine reaction, smeared for Gram-staining and cultured for yeasts and Trichomonas vaginalis. Bacterial vaginitis was diagnosed using the Nugent scoring system. Candida infection was diagnosed by microscopic examination and by culture. RESULTS: Candida spp. was the most common pathogen, documented by microscopy and culture in 35.5% of symptomatic women and 15% of asymptomatic controls (P < 0.001). Detection by culture only (negative microscopy) was documented in 18.7% of symptomatic patients and 15% of controls (P = 0.5). Bacterial vaginosis (Nugent score > or = 7) was diagnosed in 23.5% of patients and 13% of controls (P = 0.04). Trichomoniasis was present in 8.1% of symptomatic women and 4% of controls (P = 0.1). The main risk factors were antibiotic use for candidiasis and lack of use of oral contraception and condom use for trichomoniasis. CONCLUSION: Candida was by far the most common pathogen detected in our population. A statistically significant difference between patients and controls was noted for the prevalence of microscopically diagnosed candidiasis and bacterial vaginosis.

Adult↗

PubMed2002

High prevalence of toxin A-negative toxin B-positive Clostridium difficile in hospitalized patients with gastrointestinal disease.

The incidence of Clostridium difficile toxin A-negative toxin B-positive in hospitalized patients with severe gastrointestinal disease was evaluated. Of 530 stool specimens tested in parallel by two immunoassay tests, Tox A and Tox A/B (TechLab, Inc., Blacksburg, VA), 422 produced negative results on both tests. One hundred eight specimens (20.4%) tested positive by Tox A/B assay, and only 47 of them were also positive by Tox A. The 61 specimens with discrepant results were confirmed to be positive for toxin B by tissue culture cytotoxicity assay. Furthermore, 3 of the 422 specimens that were negative by enzyme immunoassay tested positive by cytotoxicity assay. The sensitivity and specificity of the Tox A/B test were 95.3% and 100%, respectively, with negative and positive predictive values of 99.3% and 100%, respectively, and a correlation rate of 99.4%. The high prevalence (56.5%) of specimens from symptomatic patients having detectable toxin B, but undetectable toxin A emphasizes the importance of using diagnostic tests that include toxin B. Furthermore, our data support the potential role of toxin B in the pathogenesis of toxigenic Clostridium difficile.

Bacterial Proteins↗

PubMed2002

In vitro susceptibility of Mycoplasma hominis clinical isolates to tetracyclines, quinolones and macrolides.

We tested the in vitro activity of levofloxacin, ciprofloxacin, doxycycline, tetracycline, erythromycin, roxithromycin, clarithromycin and azithromycin against 110 clinical isolates of Mycoplasma hominis. The minimal inhibitory concentrations (MICs) were determined with the Etest. The minimal concentrations at which 90% of the isolates were inhibited (MIC(90)) were 0.064 microg/ml doxycycline and 0.19 microg/ml tetracycline. In 9 isolates (8.1%), the MIC for doxycycline was 4-12 microg/ml. These isolates were also resistant to tetracycline with a MIC of 32-128 microg/ml. No significant difference was found between doxycycline and tetracycline (p = 0.076). Comparison of the two quinolones revealed that the MIC(90) for levofloxacin was 0.19 microg/ml and for ciprofloxacin, 0.5 microg/ml. A significant difference was found between doxycycline/tetracycline and levofloxacin or ciprofloxacin (p = 0.0001), and between levofloxacin and ciprofloxacin (p = 0.001). All the isolates were highly resistant to the macrolides with MIC > or = 256 microg/ml. This finding has important implications for cases in which Mycoplasma infection is suspected and culture and/or in vitro susceptibility tests are not available.

4-Quinolones↗

PubMed2002

Once-daily versus twice-daily intravenous administration of vancomycin for infections in hospitalized patients.

The efficacy and toxicity of once-daily (od) versus twice-daily (bd) dosing of vancomycin was compared in 121 hospitalized patients. Eighteen patients were then withdrawn from the study. Clinical and bacteriological responses were evaluated in all patients (n = 103). Nephrotoxicity was assessed in patients who did not receive nephrotoxic agents (n = 76). Ototoxicity was assessed in patients who completed two audiograms and were not receiving ototoxic agents (n = 63). No significant difference was found between the two groups for favourable clinical response: 47/51 (92.1%) and 49/52 (94.2%) in the od and bd groups, respectively. In 34 patients vancomycin was the only effective antibiotic. Fifteen of 18 (83.3%) evaluated episodes in the od and 12/16 (75.0%) evaluated episodes in the bd group showed a favourable bacteriological response. There were no significant differences between the od and bd groups for all adverse events. Nephrotoxicity developed in 4/37 (10.8%) and 3/39 (7.7%) patients, respectively. Hearing loss developed in 1/31 (3.2%) and 5/32 (15.6%). Phlebitis occurred in 7/51 (13.7%) and 12/52 (23.0%). Red man syndrome occurred in 7/51 (13.7%) and 5/52 (9.6%) in od and bd groups, respectively. The efficacy and safety profile of od administration of vancomycin is similar to that of the customary, but less convenient, bd administration.

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↗