A new scoring system to predict mortality in community-acquired pneumonia: CURB (S)-65.

OBJECTIVE: The first decision to be made in the case of community-acquired pneumonia (CAP) is whether hospitalization of the patient is mandatory. In this study, we aimed to investigate whether the addition of oxygenation parameters to CURB-65 has diagnostic value in predicting mortality in CAP. PATIENTS AND METHODS: A total of 903 CAP patients were included in the study. Patients with a CURB-65 score of 0 and 1 were classified as Group 1 and patients with a CURB-65 score of 2 or more were classified as Group 2. The prediction of mortality through Pneumonia Severity Index (PSI), CURB-65 and CURBS-65/CURBP-65 with the addition of SaO2 and PaO2 values; hence the four different models, was compared among all patient groups. RESULTS: As a result, 3.3% of the cases in Group 1 and 12.7% of the cases in Group 2 died. In both CURB-65 groups, it was noted that the frequency of patients with SaO2 <90% was significantly higher in the dead group than in the alive patient group (p=0.009 and p=0.001, respectively). In the univariate analysis, PaO2<60, and SaO2<90 were significantly associated with mortality. Model 2 (CURBS-65) and Model 3 (CURBP- 65) were examined, SaO2<90 (OR 2.08) was found to have an effect on death. In predicting mortality by the receiver operating characteristics (ROC) analysis, it was understood that the CURBS-65 score had a slightly higher area under the curve (AUC) value than CURB-65. CONCLUSIONS: As a result, it has been shown that the use of CURBS-65 scoring instead of CURB-65 clinical scoring may be more useful in predicting mortality.

E-learning in clinical microbiology and infectious diseases.

BACKGROUND: Becoming and staying competent is a challenge in clinical microbiology and infectious diseases because of dramatic increases in medical knowledge, discovery of new pathogens, emerging infections, new resistance mechanisms and laboratory techniques. E-learning is an effective way of meeting educational needs by providing more efficient and flexible training. E-learning resources have become more important to acquire new knowledge and skills, especially at a time of physical distancing. OBJECTIVES: This review aims to summarize the implementation of e-learning in clinical microbiology and infectious diseases with references to existing examples and resources. SOURCES: Literature and online resources for e-learning, online teaching/education in medical education, clinical microbiology and infectious diseases. CONTENT: The principles and common methods of e-learning and frequently used digital tools are described. For all aspects of e-learning/distance learning, available resources and examples of applications in clinical microbiology and infectious diseases are presented. IMPLICATIONS: The techniques, tools and resources described in this article should be considered for the development and implementation of e-learning programmes in clinical microbiology and infectious disease training.

Pneumonia severity indices predict prognosis in coronavirus disease-2019.

BACKGROUND: Early recognition of the severe illness is critical in coronavirus disease-19 (COVID-19) to provide best care and optimize the use of limited resources. OBJECTIVES: We aimed to determine the predictive properties of common community-acquired pneumonia (CAP) severity scores and COVID-19 specific indices. METHODS: In this retrospective cohort, COVID-19 patients hospitalized in a teaching hospital between 18 March-20 May 2020 were included. Demographic, clinical, and laboratory characteristics related to severity and mortality were measured and CURB-65, PSI, A-DROP, CALL, and COVID-GRAM scores were calculated as defined previously in the literature. Progression to severe disease and in-hospital/overall mortality during the follow-up of the patients were determined from electronic records. Kaplan-Meier, log-rank test, and Cox proportional hazard regression model was used. The discrimination capability of pneumonia severity indices was evaluated by receiver-operating-characteristic (ROC) analysis. RESULTS: Two hundred ninety-eight patients were included in the study. Sixty-two patients (20.8%) presented with severe COVID-19 while thirty-one (10.4%) developed severe COVID-19 at any time from the admission. In-hospital mortality was 39 (13.1%) while the overall mortality was 44 (14.8%). The mortality in low-risk groups that were identified to manage outside the hospital was 0 in CALL Class A, 1.67% in PSI low risk, and 2.68% in CURB-65 low-risk. However, the AUCs for the mortality prediction in COVID-19 were 0.875, 0.873, 0.859, 0.855, and 0.828 for A-DROP, PSI, CURB-65, COVID-GRAM, and CALL scores respectively. The AUCs for the prediction of progression to severe disease was 0.739, 0.711, 0,697, 0.673, and 0.668 for CURB-65, CALL, PSI, COVID-GRAM, A-DROP respectively. The hazard ratios (HR) for the tested pneumonia severity indices demonstrated that A-DROP and CURB-65 scores had the strongest association with mortality, and PSI, and COVID-GRAM scores predicted mortality independent from age and comorbidity. CONCLUSION: Community-acquired pneumonia (CAP) scores can predict in COVID-19. The indices proposed specifically to COVID-19 work less than nonspecific scoring systems surprisingly. The CALL score may be used to decide outpatient management in COVID-19.

Prognosis of hospitalized patients with community-acquired pneumonia.

INTRODUCTION: The long-term prognosis of patients with community-acquired pneumonia (CAP) has attracted increasing interest in recent years. The objective of the present study is to investigate the short and long-term outcomes in hospitalized patients with CAP and to identify the predictive factors associated with mortality. PATIENTS AND METHODS: The study was designed as a retrospective, multicenter, observational study. Hospitalized patients with CAP, as recorded in the pneumonia database of the Turkish Thoracic Society between 2011 and 2013, were included. Short-term mortality was defined as 30-day mortality and long-term mortality was assessed from those who survived 30 days. Predictive factors for short- and long-term mortality were analyzed. RESULTS: The study included 785 patients, 68% of whom were male and the mean age was 67±16 (18-92). The median duration of follow-up was 61.2±11.8 (37-90) months. Thirty-day mortality was 9.2% and the median survival of patients surviving 30 days was 62.8±4.4 months. Multivariate analysis revealed that advanced age, the absence of fever, a higher Charlson comorbidity score, higher blood urea nitrogen (BUN)/albumin ratios and lower alanine aminotransferase (ALT) levels were all predictors of long-term mortality. CONCLUSION: Long-term mortality following hospitalization for CAP is high. Charlson score and lack of fever are potential indicators for decreased long-term survival. As novel parameters, baseline BUN/albumin ratios and ALT levels are significantly associated with late mortality. Further interventions and closer monitoring are necessary for such subgroups of patients.

[Comparison of the CMV antigenemia test and CMV-DNA PCR results in solid organ transplant recipients]. / Solid organ nakli alicilarinda CMV antijenemi testi ve CMV-DNA PCR sonuçlarinin karsilastirilmasi.

Cytomegalovirus (CMV) infection is among the most common important viral infections in solid organ transplant (SOT) recipients. Diagnostic tests for detecting CMV replication are widely used for this group of patients, however there is no clear agreement on the cut-off levels for interpretation of clinical decisions especially when the low level of viral load is detected. In this study, CMV pp65 antigenemia test results were compared with plasma CMV-DNA levels detected by quantitative real-time polymerase chain reaction (qPCR) in samples of kidney and liver transplant recipients in the Central Laboratory of Dokuz Eylul University Hospital between 2011 and 2013, and the correlation between these two tests and viral load equivalent to antigenemia positivity were determined. In the study, pp65 antigenemia and CMV-DNA qPCR results were evaluated retrospectively. The samples from the same patients were included if the time between antigenemia and CMV-DNA qPCR tests were less than 48 hours. SPSS v15.0 was used for correlation, regression and ROC curve analysis. The results of the 217 samples collected from 100 patients (59 male, 41 female; age range: 16-71, mean age: 46 ± 13 years), 36 liver and 64 kidney recipients were evaluated in the study. Of the patients 80% were CMV IgM negative, IgG positive; 1% was CMV IgG and IgM positive; 2% were CMV IgM and IgG negative, while for 17 patients serological results could not be reached. CMV pp65 antigenemia and CMV-DNA were both negative in 102 (47%) samples, while both were positive in 37 (17%) samples. The single sample from a case with CMV IgM and IgG positivity yielded negative results for both antigenemia and CMV-DNA tests. In 78 samples antigenemia were negative and CMV-DNA qPCR were positive, while there were no samples with antigenemia positive and qPCR negative. Mean values of antigenemia and qPCR tests were 23 positive cells/200.000 leukocytes (range: 1 to 230 positive cells) and 12.595 copies/ml (range: 180 to 106.311 copies/ml), respectively. There was a significant correlation between antigenemia and qPCR results among the samples that were positive by both assays (r= 0.785). ROC curve analysis showed that CMV viral load of 205 copies/ml in plasma corresponds to ≥ 1 pp65 antigen positive cells per 200.000 leukocytes (sensitivity: 91.7%, specificity: 90.3%). Higher analytical sensitivity of qPCR test can be explained by the results of CMV-DNA PCR positive and antigenemia negative samples. Non-existence of samples with antigen positive and PCR negative results supported this finding. ROC analysis showed that any sample with CMV-DNA qPCR result less than 205 copies/ml, could be accepted as pp65 antigenemia negative. This viral load value is valid only for the studied patient group and assays, therefore could be changed according to study population and tests.

Comparison of p57, c-erbB-2, CD117, and Bcl-2 expression in the differential diagnosis of hydatidiform mole and hydropic abortion.

PURPOSE: To explore the utility of p57, c-erbB-2, CD 117, and Bel-2 immunostaining in the differential diagnosis of complete hydatidiform mole (CHM), partial hydatidiform mole (PHM), and hydropic abortion (HA). MATERIALS AND METHODS: Immunohistochemical expression of the p57, c-erbB-2, CD117, and Bel-2 proteins were investigated semi-quantitatively using paraffin-embedded tissue sections from histologically unequivocal cases of CHM (n = 20), PHM (n = 23), and HA (n = 17). RESULTS: All cases of CHM exhibited a striking absence of p57 expression. The percentage of positive p57 staining was similar between PHMs (73.9%) and HAs (76.5%) (p >0.05). The comparison of c-erbB-2 expression revealed a significantly higher percentage of positive c-erbB-2 staining in CHMs (45%) compared with that in PHMs (8.7%) and HAs (5.9%) (p = 0.006 and 0.01, respectively). The CD 117 expression pattern (immunoreactivity score, percentage of positive cells, and staining intensity) was significantly lower in HAs compared with that in PHMs and CHMs (p < 0.05 for all). A significantly increased Bel-2 expression pattern was observed in HAs compared with that in PHMs and CHMs (p < 0.05 for all). CONCLUSION: Immunohistochemical examination of p57, c-erbB-2, CD 117, and Bel-2 expression represents a relatively simple, reliable, and cost-efficient procedure to definitively distinguish among CHM, PHM, and HA.

Fecal calprotectin: can be used to distinguish between bacterial and viral gastroenteritis in children?

OBJECTIVE: Fecal calprotectin is used as a good indicator of intestinal mucosal inflammation. The aim of this study is to evaluate the diagnostic value of fecal calprotectin (f-CP) for the etiology of acute gastroenteritis in children. MATERIALS AND METHODS: All patients presenting with acute diarrhea (<18 years) who had 3 or more soft or watery stools per day were enrolled in this study. Stool microscopic examination and cultures for bacteria and parasites were performed. Polymerase chain reaction test was also applied to stool samples for viruses (Rotavirus, Adenovirus, Norwalk, and Astrovirus). The level of f-CP was carried out by using enzyme-linked immunosorbent assay test. RESULTS: Eighty-four patients with diarrhea were enrolled. The f-CP level was higher in patients with microscopic examination positive (n=17) (median with interquartile range, 1610.0 [908.8-2100] mg/L) than in patients with microscopic examination negative (n=67) (123.8 [25.0-406.3] mg/L) (P<.001). Concentrations of f-CP in patients with stool culture positive (1870.0 [822.5-2100] mg/L) were significantly elevated compared with the concentrations of the patient with virus detected in stool (95.0 [21.3-240.9] mg/L) (P<.001). In the diagnosis for bacterial acute gastroenteritis, the area under the receiver operating characteristic curve for f-CP was 0.867 (95% confidence interval, 0.763-0.971), sensitivity was 88.9%, and specificity was 76.0% if the threshold was taken as 710 mg/L. CONCLUSION: We conclude that f-CP, which is useful, valuable, noninvasive, easily and rapidly measured laboratory test along with simple microscopic examination of stool, can be used as an indicator of intestinal inflammation and to distinguish the bacterial gastroenteritis from the viral gastroenteritis.

A 5-year study of adenoviruses causing conjunctivitis in Izmir, Turkey.

Adenoviruses are a common cause of conjunctivitis. Genotypes are diverse and differ according to population and geographical distribution of the virus. There is limited data regarding ocular adenoviral infections and genotype distribution in Turkey. This study aimed to determine the adenovirus genotypes and their epidemiological features among patients with conjunctivitis between 2006 and 2010, in Izmir, Turkey. Adenoviral DNA was detected by PCR in 213 of 488 (44%) of the ocular samples collected from patients with viral conjunctivitis during the 5-year study period. Of these, 101 (47%) were randomly chosen and genotyped by sequence analysis. Seven genotypes were identified, including 3, 4, 8, 11, 19, 37, and 53. Genotype 8 and 4 were the dominant types detected in 67 (66.3%) and 25 (24.7%) of the samples, respectively. Other five genotypes (3, 11, 19, 37, 53) were detected in 9 (8.9%) samples. Genotype and seasonal differences observed throughout the study. Human adenoviruse (HAdV)-8 was the most frequent type, except 2008. The prevalence of genotype 4 increased starting from 2006, became dominant in 2008 and decreased in the following years. The peak season was mostly spring months, although it was possible to detect positive samples throughout the year. In conclusion, genotype 8 followed by genotype 4 was the most frequent adenoviral types causing conjunctivitis during the 5-year study period. Findings suggest that there is a slow shift between genotypes throughout the years.

Value of rapid antigen test for pandemic influenza A (H1N1) 2009 in the pediatric emergency department.

OBJECTIVE: Pandemic H1N1 influenza is the predominant influenza virus circulating in Turkey in 2009. Because of the clinical manifestations of influenza overlap with those attributable to other common respiratory illnesses of childhood, establishing a diagnosis of influenza requires confirmatory testing. The aim of our study was to define the predictive value of rapid influenza antigen detection test in children presenting to a pediatric emergency care department with influenza-like illness and to compare with clinical signs and symptoms. METHODS: From October to November 2009, 3646 patients presented with influenza-like illness to the pediatric emergency department. Influenza-like illness is defined as fever with cough or sore throat in the absence of a known cause other than influenza. Enrollment criteria included fever and at least one of the following symptoms: coryza, cough, headache, sore throat, or myalgia. All 322 enrolled patients received a nasal wash for rapid influenza diagnostic tests, and the results were compared with clinical signs. RESULTS: Rapid influenza detection test result was found positive in 167 (51.9%) of 322 patients. Clinical findings included fever as the presenting complaint (100%), fever (≥38 °C) (93.4%), cough (91.3%), rhinorrhea (66.1%), sore throat (35.1%), vomiting-diarrhea (22.4%), myalgia (20.2%), headache (18%) and shortness of breath (12.1%). There were 211 patients (65.5%) at high risk for the development of complications of pandemic H1N1 influenza A such as chronic lung disease (asthma) (n = 103, 48.8%), age younger than 2 years (n = 78, 37%), and neurologic disease (n = 10, 4.7%). The positivity rate and sensitivity of the test increase up to 70% in patients, who had the high body temperature (≥39 °C). The rapid test achieved the highest sensitivity in patients, who have high fever (≥39 °C), myalgia, vomiting, and diarrhea. CONCLUSIONS: We found that if the patients have high fever (≥39 °C), myalgia, and vomiting-diarrhea together, the likelihood of rapid antigen test positivity rate increases in patients, who presented with influenza-like illness.

Multicentre evaluation of central nervous system infections due to Flavi and Phleboviruses in Turkey.

OBJECTIVES: Flavi- and Phleboviruses associated with central nervous system (CNS) infections including West Nile Virus (WNV), Tick-borne Encephalitis Virus (TBEV) and Toscana Virus (TOSV) cause significant morbidity and mortality in humans. In this study, the impact of these agents have been investigated in CNS infections at referral hospitals in two provinces in Turkey, where circulation of these viruses have previously been recognized. METHODS: In the study, 258 samples from 126 individuals from Ankara and 113 samples from 108 individuals from Izmir provinces collected in 2010 were included. Viral RNAs were investigated by multiple genus and strain specific primers. Commercial serological assays were employed in screening and reactive results were evaluated with additional assays and by plaque reduction neutralization assay. RESULTS: Two cases of WNV CNS infections, 14 cases of TOSV infections and one TBEV-exposed individual were identified via serological testing. WNV infections in 61 and 56-year old individuals from Ankara presented with fever and encephalitis without skin rash and residual neurologic damage. TOSV-associated cases from both provinces mainly displayed signs of meningitis. TOSV exposure was documented for the first time from Izmir. CONCLUSIONS: WNV, TBEV and TOSV infections must be considered in cases of meningoencephalitis of unknown etiology in Turkey.

The remaining challenges of pneumococcal disease in adults.

Pneumococcal disease can be divided into invasive disease, i.e. when bacteria are detected in normally sterile body fluids, and noninvasive disease. Pneumococcal disease occurs more frequently in younger children and older adults. It is estimated that, in 2050, 30.3% of the European population will be ≥65 yrs old, compared with 15.7% in 2000. Preventive medicine, including vaccination, is essential for the promotion of healthy ageing. Uptake rates for influenza vaccination in the elderly are generally low, despite recommendations in many countries. In addition, it has been reported that influenza infections can make people more susceptible to pneumococcal infections. Despite pneumococcal vaccination, case fatality rates for patients hospitalised with invasive pneumococcal disease have remained at around 12% since the 1950s. Even when effective antibiotic therapy is administered, mortality can be high amongst immunocompetent patients in intensive care. Timely and accurate diagnosis of pneumococcal disease and identification of patients at high risk of poor outcome is essential to ensure that adequate treatment, including hospitalisation when necessary, is implemented as early as possible. Improved diagnostic techniques and more efficacious treatments may help to reduce the burden of pneumococcal disease, but preventive measures, such as influenza and pneumococcal vaccination, should be promoted in order to avoid preventable disease, particularly in the elderly.

[A real-time PCR assay for the quantification of hepatitis B virus DNA and concurrent detection of YMDD motif mutations]. / Hepatit B Virus DNA Düzeyi Tayini ve Es Zamanli Olarak YMDD Motif Mutasyonu Analizi Yapan Gerçek Zamanli PCR Testi.

Monitoring therapy in chronic hepatitis B patients receiving lamivudine therapy, is done by two different assays; determination of viral load and genotypic resistance. These methods are labor intensive and time consuming. It was aimed to develop an assay to quantitate hepatitis B virus (HBV) DNA in serum and detect YMDD (thyrosine, methionine, aspartate, aspartate) motif mutations in the same run. The assay was based on real-time polymerase chain reaction (Rt-PCR) with YMDD-specific hybridization probes. Determination of YMDD motif was done by melting temperature analysis. External standard curve was used for quantifying viral DNA, which was generated by standard sera (VQC S2220) including HBV-DNA between concentrations of 1000 to 3 million copies/ml. The assay was compared with commercial quantitative kit (Artus HBV RG PCR; Qiagen, Germany), commercial line prob assay (INNO-LiPA HBV DR v1.0; Innogenetics, Belgium) and direct DNA sequencing method. Thirty-eight serum samples obtained from 20 chronic hepatitis B patients (7 female, 13 male; age range: 27-70 years) treated with only lamivudine and were negative for HIV and HCV antigen and antibodies were tested in the study. The analytical sensitivity of the assay was found as 200 copies/ml, with a dynamic range of 1 x 103 to 3 x 107 copies/ml. PCR efficiency of the in-house assay was found to be 1.98. Comparison of log10 HBV-DNA concentrations determined by the in-house and commercial quantitative kits showed a significant correlation (r= 0.681). Melting temperature (Tm) analysis was used for the YMDD motif determination and found to be 59.86°C for YMDD, 56.34°C for YVDD and 55.10°C for YIDD. The results of the in-house assay, DNA sequencing and LiPA were concordant in samples with homogeneous virus population, and in-house assay could also detect the major type of YMDD motif in mixed viral populations The Rt-PCR method which was developed in this study is a rapid, accurate and reproducible method for quantifying HBV-DNA and detecting the predominant YMDD motif in the same run in two hours duration. It was concluded that this method may be a convenient tool for monitoring HBV-infected patients receiving lamivudine treatment.

Naturally occurring MHR variants in Turkish patients infected with hepatitis B virus.

Major B-cell epitopes are located at the major hydrophilic region (MHR) of hepatitis B virus (HBV) surface antigen (HBsAg). The genotypes, subtypes, and naturally occurring amino acid (aa) substitutions of MHR were analyzed in 81 Turkish adult patients (41 inactive HBsAg carriers and 40 patients with chronic hepatitis B) by direct sequencing of the S gene fragment. All the isolates were genotype D according to the phylogenetic analysis. The most common HBsAg subtype was ayw2, followed by ayw3 while one isolate specified ayw4 by encoding Leu127. MHR variants were detected in 22 of the 81 (27.2%) isolates. The prevalence was significantly higher in the chronic hepatitis B group (42.5%) compared to inactive HBsAg carriers (12.2%). Twenty-two samples had a total of 26 amino acid substitutions involving 14 positions. The majority of the patients had a single variation. Most of the amino acid substitutions were located at the HBs1 region of the MHR, while 9 of the 26 were in the classic "a" determinant (aa 124-147). When samples with "a" variants were evaluated by two different commercial HBsAg tests, only the isolate with Ser143Leu variation had a decreased reactivity in the assay using monoclonal antibodies for capture and detection. In conclusion, the findings of the study was in accordance with previous studies showing HBV genotype and subtype homogeneity (genotype D/ayw) in Turkey. Naturally occurring MHR and "a" determinant variants were common, especially among chronic hepatitis B patients. The influence of detected "a" variants on diagnostic assays was limited.

A new hepatitis B virus vaccine escape mutation in a renal transplant recipient.

Surface antigen mutations of hepatitis B virus (HBV) may lead to immune escape and cause failure of immunization. In this report, the development of a chronic HBV infection in a vaccinated renal transplant recipient with pre-existing anti-HBs antibody is documented. The sequencing data showed that the HBV strain carried five amino acid substitutions in the major hydrophilic region of the S protein, one (sS143L) located at the "a" determinant. A commercial HBsAg assay failed to detect the mutant antigen.

Pulmonary complications in heart transplant recipients.

BACKGROUND: Heart transplantation is an important therapeutic option for patients with end-stage disease, but is associated with major pulmonary complications. PATIENTS AND METHODS: We retrospectively reviewed the posttransplant follow-up of 34 orthotopic heart transplant recipients. RESULTS: Two of the 34 patients died of cardiac failure in the early postoperative period. Among the surviving patients, 10 (31.3%) developed pulmonary complications, all within the first 6 months: hospital-acquired bacterial pneumonia in five, fungal pneumonia in three, posttransplant lymphoproliferative disease in one, and community-acquired pneumonia in one patient. None of the patients developed transplantation-related malignancy. The overall mortality was 35.3%. Pneumonia-related mortality rate of 14.7% was due to early-onset nosocomial pneumonias, which were caused by bacterial and opportunistic microorganisms. Extrapulmonary causes of mortality were cardiac failure, meningitis, septicemia, and acute rejection. Cytomegalovirus antigenemia in the first month was associated with a poor prognosis. The frequency of pulmonary complications was higher among older patients and those who developed moderate rejection in the first month (P=.014 and P=.036, respectively). CONCLUSION: Pulmonary infections after heart transplantation occurred more frequently during the first 6 months posttransplantation, accounting for a significant portion of the posttransplantation mortality.

Prophylactic use of low-dose, on-demand, intramuscular hepatitis B immunoglobulin and lamivudine after liver transplantation.

The combination of hepatitis B immunoglobulin (HBIG) and antivirals (nucleos[t]ide analogs) has extended the applicability of orthotopic liver transplantation (OLT) for patients with hepatitis B virus (HBV)-related liver disease. However, HBIG administrations have an extremely high cost. Herein, we evaluated our results with low-dose, on-demand, intramuscular HBIG plus lamivudine (LAM) prophylaxis after OLT. The HBV DNA status in 40 patients at the time of OLT determined the treatment: group A (n = 22), HBV DNA (-), no antiviral pretreatment; group B (n = 11), HBV DNA (-), after LAM; group C (n = 3), HBV DNA (+) after LAM (LAM resistance/Adefovir [ADV] unavailable); group D (n = 2), HBV DNA (+), no antiviral pretreatment; and group E (n = 2), HBV DNA (-) after LAM + ADV (LAM resistance/ADV available). Five patients died within 12 months after OLT unrelated to HBV infection. The remaining 35 patients were followed for a median duration of 16 months (range, 6-93 months). Only two recipients from group C, who were transplanted despite LAM resistance + no ADV pretreatment, revealed recurrent HBV infections at 14 and 16 months posttransplantation; they were then treated successfully with ADV as it became available. The third group C recipient had undetectable HBV DNA at 18 months after OLT. The mean cumulative doses of HBIG administered within the first, second, and third years were 34,014, 5258, and 5090 IU, respectively. In conclusion, low-dose, on-demand, intramuscular HBIG plus (LAM +/- ADV) prophylaxis is a safe, efficient, and cost-effective regimen to prevent recurrent HBV infection following OLT. OLT despite untreated LAM resistance may require sustained higher serum HBsAb levels after surgery.

Label-free electrochemical hybridization genosensor for the detection of hepatitis B virus genotype on the development of Lamivudine resistance.

The resistance analysis related to the hepatitis B virus (HBV) genotyping and treatment procured key information for the study of infected patients. The aim of this study was to develop a novel assay for the voltammetric detection of DNA sequences related to the HBV genotype on the development of lamuvidine resistance by monitoring the oxidation signal of guanine. This new technique not only provides a rapid, cost-effective, simple analysis but also gives information concerning both genotyping and lamivudine resistance. Synthetic single-stranded oligonucleotides ("probe") including YMDD (HBV wild type) YVDD, or YIDD (mutations in the YMDD) variants have been immobilized onto pencil graphite electrodes with the adsorption at a controlled potential. The probes were hybridized with different concentrations of their complementary ("target") sequences such as synthetic complementary sequences, clonned PCR products, or real PCR samples. The formed synthetic hybrids on the electrode surface were evaluated by a differential pulse voltammetry technique using a label-free detection method. The oxidation signal of guanine was observed as a result of the specific hybridization between the probes and their synthetic targets and specific PCR products. The response of the hybridization of the probes with their single-base mismatch oligonucleotides at PGE was also detected. Control experiments using the noncomplementary oligonucleotides were performed to determine whether the DNA genosensor responds selectively. Numerous factors, affecting the probe immobilization, target hybridization, and nonspecific binding events, were optimized to maximize the sensitivity and reduce the assay time. Under the optimum conditions, 457 fmol/mL was found as the detection limit for target DNA. With the help of the appearance of the guanine signal, the new protocol is based on the electrochemical detection of HBV genotype for the development of lamuvidine resistance for the first time. Features of this protocol are discussed and optimized.

Failure to detect Chlamydia pneumoniae DNA in cerebral aneurysmal sac tissue with two different polymerase chain reaction methods.

OBJECTIVE: Chlamydia pneumoniae (C pneumoniae) is a common cause of a usually mild, community acquired pneumonia. This organism, however, can spread from the respiratory tract into other parts of the body and has been detected in up to 70% of atheromatous lesions in blood vessels. Although the exact mechanism of the C Pneumoniae contribution to the pathogenesis of atherosclerosis remains unknown, prophylactic antibiotic trials are planned for people at high risk for coronary disease. METHOD: In this study the authors aimed to investigate C pneumoniae DNA content in the cerebral aneurysmal sac tissue with the aid of polymerase chain reaction (PCR) method. C pneumoniae DNA was searched in 15 surgically clipped and removed aneurysmal sac tissue and in two tumour (an ependymoma of the fourth ventricle and a craniofaringoma) samples by touchdown enzyme time release PCR (TETR PCR) targeting 16S rRNA gene and by nested PCR targeting ompA gene. RESULTS: Both PCR methods were sensitive to detect in C pneumoniae 4x10(-2) genomes. C pneumoniae DNA was not detected in any of the 17 sample tissues of these patients. CONCLUSION: The contribution of C pneumoniae in the development of intracranial aneurysms cannot be excluded despite the results of this study. Further studies on the possible role of C pneumoniae or any other micro-organisms in the pathogenesis of aneurysms should be performed.