The evolutionary history of hepaciviruses

In the search for natural reservoirs of hepatitis C virus (HCV), a broad diversity of non-human viruses within the Hepacivirus genus has been uncovered. However, the evolutionary dynamics that shaped the diversity and timescale of hepaciviruses evolution remain elusive. To gain further insights into the origins and evolution of this genus, we screened a large dataset of wild mammal samples (n = 1,672) from Africa and Asia, and generated 34 full-length hepacivirus genomes. Phylogenetic analysis of these data together with publicly available genomes emphasizes the importance of rodents as hepacivirus hosts and we identify 13 rodent species and 3 rodent genera (in Cricetidae and Muridae families) as novel hosts of hepaciviruses. Through co-phylogenetic analyses, we demonstrate that hepacivirus diversity has been affected by cross-species transmission events against the backdrop of detectable signal of virus-host co-divergence in the deep evolutionary history. Using a Bayesian phylogenetic multidimensional scaling approach, we explore the extent to which host relatedness and geographic distances have structured present-day hepacivirus diversity. Our results provide evidence for a substantial structuring of mammalian hepacivirus diversity by host as well as geography, with a somewhat more irregular diffusion process in geographic space. Finally, using a mechanistic model that accounts for substitution saturation, we provide the first formal estimates of the timescale of hepacivirus evolution and estimate the origin of the genus to be about 22 million years ago. Our results offer a comprehensive overview of the micro- and macroevolutionary processes that have shaped hepacivirus diversity and enhance our understanding of the long-term evolution of the Hepacivirus genus.

[The ineffective or short-term recurrence of trigeminal neuralgia after microballoon compression:different causes and management strategies]

Objectives: To explore the causes of ineffective or short-term recurrence (within 3 months)of trigeminal neuralgia treated by percutaneous microballoon compression(PBC), and to examine the reoperative strategies and clincal outcomes of modified PBC. Methods: The clinical data of 21 patients with ineffective or short-term recurrence after PBC treatment (5.7% of 369 patient received PBC) admitted to the Department of Neurosurgery,Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University from June 2018 to June 2020 were retrospectively analyzed.There were 8 males and 13 females, mean aged 66.6 years (range:51 to 79 years).Among them,2 patients was ineffective after PBC and 19 patients relapsed within 3 months.The distribution of pain was along V₂ branches in 2 cases,V₃ branches in 3 cases,V₁+V₂ branches in 1 case,and V₂+V₃ branches in 15 cases.The mean time of recurrence was 46.8 days (range:23 to 76 days) among the 19 patients with short-term recurrence.The patients were divided into 4 types based on the causes of postoperative ineffectiveness or short-term recurrence.TypeⅠ:extracapsular false pear (1 case);Type Ⅱ:invalid true pear(2 cases);Type Ⅲ:capsular rupture (6 cases);Type Ⅳ:compression blind area (12 cases).The individualized modified PBC operation plans were used according to the types of the patients and the clinical effect and complications of the patients were observed. Results: The pain symptoms of the patients disappeared after the second operation with immediate effective rate of 100%. All patients had mild facial numbness after surgery.Five patients(23.8%,5/21) had masseter muscle weakness, 3 (14.3%,3/21) had peristomatous herpes, 1(4.8%, 1/21) had diplopia.No bleeding or other complications occurred.All patients were followed up for at least 12 months (range:13 to 28 months). One patient (4.8%,1/21) (compression blind area type) had pain recurrence 9 months after surgery, and cured by receiving the original modified PBC surgery again with no recurrence after another 13 months' follow-up. None of the other patients relapsed during the follow-up period.Up to the last follow-up,19 cases(90.5%,19/21) were cured,and 2 cases (9.5%,2/21) were relieved. Conclusions: The main reason for ineffective or short-term recurrence of PBC in trigeminal neuralgia patients is the ineffectively compressed of trigeminal ganglion.According to the different types of patients,the use of individualized modified surgical scheme can improve the efficacy of PBC surgery.

Occurrence of gastrointestinal nematodes in captive nonhuman primates at Matang Wildlife Centre, Sarawak

Gastrointestinal nematodes can cause assorted health problems to human and other primates. The status of gastrointestinal nematodes in non-human primates remained less documented in Malaysia. This study aimed to determine the occurrence of gastrointestinal nematodes recovered from the fecal samples of captive non-human primates at the Matang Wildlife Centre (MWC), Sarawak. Fresh fecal samples were collected from 60 non-human primates of six species (i.e. Orangutan, Bornean gibbon, Silvered Leaf monkey, Slow loris, Pig-tailed macaque, and Long-tailed macaque) and processed using simple fecal floatation method and fecal sedimentation method. This study shows high prevalence of nematode infection (>=50%) and co-infection (22 from 45 infected individuals) in all species of captive non-human primates found in MWC, except one individual of young Silvered Leaf monkey was negative for nematode. From these, eight genera of 11 species and one unknown nematode larvae were recovered and among them Oesophagostomum sp., Ascaris sp., and Strongyloides sp. were the most common nematodes infecting the non-human primates. All the Bornean gibbon (n=7) were found to be infected with nematodes. Moreover, Long-tailed macaques at the centre were heavily infected by Ascaris sp. (number of total count, n_t = 2132; total mean abundance, MA=113.70). This is the first report of high prevalence nematode infection on multiple species of captive non-human primates in a wildlife centre located in Sarawak. Some of the nematodes are of zoonotic potential. This information is important for health care management, both in-situ and ex-situ conservations of captive and free-ranging nonhuman primates.

[Etiological analysis on patients with vertigo or dizziness]

Objective: To explore the spectrum of causes for patients with vertigo or dizziness in the Department of Neurology, and provide a reference for diagnosis and treatment of patients with vertigo or dizziness. Methods: Clinical data of patients in the Department of Neurology, Baotou Central Hospital between January 2016 and September 2017 was retrospectively analyzed. The target group under study was diagnosed based on the uniform diagnostic criteria. Results: A total of 9 200 patients with a chief complaint of vertigo or dizziness were included. The ratio of male to female was 1∶1.8, with an age range of 19 to 85 years. The different etiology was as follows: benign paroxysmal positional vertigo (BPPV) (3 148 cases, 34.22%), persistent postural-perceptual dizziness (PPPD) (2 006 cases, 21.80%), vertigo caused by cerebrovascular diseases (1 463 cases, 15.90%), vestibular neuritis (741 cases, 8.05%), vestibular migraine (536 cases, 5.83%), vestibular paroxysmia (336 cases, 3.65%), Ménière disease (187 cases, 2.03%), drug-induced vertigo (96 cases, 1.04%), neurological degenerative diseases (74 cases, 0.80%), sudden sensorineural hearing loss (51 cases, 0.55%), multiple sclerosis and neuromyelitis optica (21 cases, 0.23%), other reasons (22 cases, 0.24%), unknown reasons (519 cases, 5.64%). Conclusions: Dizziness is resulted from various causes, and BPPV is the most common reason. Vertigo caused by cerebrovascular diseases appears to gradually increase along with age. PPPD is very common in clinical practice, so clinicians needs to be highly aware of BPPV and PPPD. Although those dizziness diseases have a low incidence, they should not be ignored. There are still certain proportion of vertigo patients whose diagnosis are undetermined.

Co-infections of ectoparasite species in synanthropic rodents of western Sarawak, Malaysian Borneo

Little is known regarding infestation of ectoparasites in synanthropic rodents in Sarawak, Malaysia. A total of 44 rodents from three species (Rattus rattus, Rattus tiomanicus and Sundamys muelleri) were trapped from four residential areas in western Sarawak, Malaysia, for ectoparasites screening. A total of 117 ectoparasites from three hard tick species (Ixodes granulatus, Haemaphysalis sp. 1, Haemaphysalis sp. 2), three mesostigmatid mite species (Laelaps echidninus, Laelaps sedlaceki, and Laelaps nuttalli), one trombiculid mite (chigger species), and one louse species (Hoplopleura sp.), were recovered from 32 infected rodents (72.73% infestation). Infestations by multiple ectoparasite species on the same rodent individuals were recorded in R. rattus and R. tiomanicus (28.1%, n=9) in this study, while Sundamys muelleri was only infested with L. echidninus. One R. rattus individual was co-infected with ticks, louse, and mesostigmatid mite. L. echidninus was the generalist ectoparasite species that infected all three rodent species in three of the residential areas studied. Ectoparasite species diversity was significantly different among four residential areas based on Shannon index and diversity t-test (p-value <0.05). This study provides the first record of the association of synanthropic rodents with multiple ectoparasite infections in residential areas of western Sarawak, Malaysia.

Diagnostic performance of conventional MRI parameters and apparent diffusion coefficient values in differentiating between benign and malignant soft-tissue tumours

AIM

To compare the abilities of conventional magnetic resonance imaging (MRI) and apparent diffusion coefficient (ADC) in differentiating between benign and malignant soft-tissue tumours (STT).

MATERIAL AND METHODS

A total of 123 patients with STT who underwent 3 T MRI, including diffusion-weighted imaging (DWI), were retrospectively analysed using variate conventional MRI parameters, ADC_mean and ADC_min.

RESULTS

For the all-STT group, the correlation between the malignant STT conventional MRI parameters, except deep compartment involvement, compared to those of benign STT were statistically significant with univariate analysis. Maximum diameter of the tumour (p=0.001; odds ratio [OR], 8.97) and ADC_mean (p=0.020; OR, 4.30) were independent factors with multivariate analysis. For the non-myxoid non-haemosiderin STT group, signal heterogeneity on axial T1-weighted imaging (T1WI; p=0.017), ADC_mean, and ADC_min (p=0.001, p=0.001), showed significant differences with univariate analysis between malignancy and benignity. Signal heterogeneity in axial T1WI (p=0.025; OR, 12.64) and ADC_mean (p=0.004; OR, 33.15) were independent factors with multivariate analysis.

CONCLUSION

ADC values as well as conventional MRI parameters were useful in differentiating between benign and malignant STT. The ADC_mean was the most powerful diagnostic parameter in non-myxoid non-haemosiderin STT.

Gestural praxis in young adults with mild to moderate intellectual disabilities

BACKGROUND

Praxis functioning in the population with intellectual disabilities (ID) has been poorly studied. The goal of this research was to look for a starting point to study the praxic functioning in young adults with mild to moderate ID.

METHOD

Thirty young adults with ID and 30 young adults without ID, between the ages of 18 and 35 years, participated in this study. All participants completed tests that assessed gestural praxis.

RESULTS

It was possible to observe similar praxis behaviour in the group with ID in almost all domains studied, albeit showing statistical values lower than those of the group without ID.

DISCUSSIONS

Despite the high number of errors committed, the sample of participants with ID was able to reach the goal of praxic tasks performed; such errors may be associated with a deficit in the development of various brain functions and not only with praxis functioning, mainly related to a lower yield in terms of planning, monitoring and correcting intentional movement.

In-silico prediction of blood-brain barrier permeability

The ability of penetration of the blood-brain barrier is one of the significant properties of a drug or drug-like compound for the central nervous system (CNS), which is commonly expressed by log BB (log BB = log (C (brain)/C (blood))). In this work, a dataset of 320 compounds with log BB values was split into a training set including 198 compounds and a test set including 122 compounds according to their structure properties by a Kohonen's self-organizing map (SOM). Each molecule was represented by global and shape descriptors, 2D autocorrelation descriptors and RDF descriptors calculated by ADRIANA.Code. Several quantitative models for prediction of log BB were built by a multilinear regression (MLR), a support vector machine (SVM) and an artificial neural network (ANN) analysis. The models show good prediction performance on the test set compounds.

Clinical and molecular epidemiology of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae in a long-term study from Japan

The detection rates of extended-spectrum β-lactamase (ESBL)-producing bacteria in Japan are very low (∼5%) compared with those obtained worldwide. Further, the current trend of these bacteria in Japan is not known, and few studies with longitudinal observations have been reported. To obtain epidemiologic data on ESBL-producing bacteria, their genotypic features, and their antibiotic resistance patterns in Japan, we analyzed bacterial isolates from hospitalized patients at our institution over the 7-year period from 2003 to 2009. Of 2,304 isolates, 202 (8.8%) were found to be ESBL producers, including Escherichia coli, Klebsiella pneumonia, and Proteus mirabilis. The detection rates of the ESBL-producing isolates gradually increased and reached 17.1% and 10.5% for the E. coli and K. pneumoniae strains, respectively, in 2009. Genotyping analysis showed that ∼90% of the ESBL-producing isolates carried the CTX-M genotype, in which the CTX-M-9 group was predominant, although the CTX-M-2 group is considered to be the main genotype in Japan; further, many of the strains produced multiple β-lactamases. The detection rates of ESBL-producing bacteria may tend to be high within a limited region in Japan. A countrywide survey is required to understand the trend for ESBL-producing bacteria at the national level. In addition, our findings suggest that the genotypes of the detected ESBL producers are similar to those exhibiting a successful nosocomial spread worldwide.

Surveillance of antibiotic resistance in Neisseria gonorrhoeae in the WHO Western Pacific and South East Asian regions, 2007-2008

Long-term surveillance of antimicrobial resistance in Neisseria gonorrhoeae has been conducted in the World Health Organization (WHO) Western Pacific Region (WPR) to optimise antibiotic treatment of gonococcal disease since 1992. In 2007 and 2008, this Gonococcal Antimicrobial Surveillance Programme (GASP) was enhanced by the inclusion of data from the South East Asian Region (SEAR) and recruitment of additional centres within the WPR. Approximately 17,450 N. gonorrhoeae were examined for their susceptibility to one or more antibiotics used for the treatment of gonorrhoea by external quality controlled methods in 24 reporting centres in 20 countries and/or jurisdictions. A high proportion of penicillin and/or quinolone resistance was again detected amongst isolates tested in North Asia and the WHO SEAR, but much lower rates of penicillin resistance and little quinolone resistance was present in most of the Pacific Island countries. The proportion of gonococci reported as 'resistant', 'less susceptible' or 'non-susceptible' gonococci to the third-generation cephalosporin antibiotic ceftriaxone lay in a wide range, but no major changes were evident in cephalosporin minimal inhibitory concentration (MIC) patterns in 2007-2008. Altered cephalosporin susceptibility was associated with treatment failures following therapy with oral third-generation cephalosporins. There is a need for revision and clarification of some of the in vitro criteria that are currently used to categorise the clinical importance of gonococci with different ceftriaxone and oral cephalosporin MIC levels. The number of instances of spectinomycin resistance remained low. A high proportion of strains tested continued to exhibit a form of plasmid mediated high level resistance to tetracyclines. The continuing emergence and spread of antibiotic resistant gonococci in and from the WHO WPR and SEAR supports the need for gonococcal antimicrobial resistance surveillance programs such as GASP to be maintained and potentially expanded.

Lentinula edodes (Shiitake) mushroom extract protects against hydrogen peroxide induced cytotoxicity in peripheral blood mononuclear cells

Lentinula edodes (Berk) Pegler, commonly known as Shiitake mushroom has been used as medicinal food in Asian countries, especially in China and Japan and is believed to possess strong immunomodulatory property. In the present study, the methanolic extract of the fruit bodies of L. edodes was investigated for cytoprotective effect against H2O2-induced cytotoxicity in human peripheral blood mononuclear cells (PBMCs) by measuring the activities of xanthine oxidase (XO) and glutathione peroxidase (GPx) . H2O2 at a concentration of 5 microM caused 50% inhibition of PBMCs viability. The extract improved the PBMC viability and exerted a dose-dependent protection against H2O2-induced cytotoxicity. At 100 microg/ml of extract concentration, the cell viability increased by 60% compared with the PBMCs incubated with H2O2 alone. The extract also inhibited XO activity in PBMC, while showing moderate stimulatory effect on GPx. However, in the presence of H2O2 alone, both the enzyme activities were increased significantly. The GPx activity increased, possibly in response to the increased availability of H2O2 in the cell. When the cells were pretreated with the extract and washed (to remove the extract) prior to the addition of H2O2, the GPx and XO activities as well as the cell viability were comparable to those when incubated with the extract alone. Thus, it is suggested that one of the possible mechanisms via which L. edodes methanolic extract confers protection against H2O2-induced oxidative stress in PBMC is by inhibiting the superoxide-producing XO and increasing GPx activity which could rapidly inactivate H2O2.

Identification of potential influenza virus endonuclease inhibitors through virtual screening based on the 3D-QSAR model

Influenza endonucleases have appeared as an attractive target of antiviral therapy for influenza infection. With the purpose of designing a novel antiviral agent with enhanced biological activities against influenza endonuclease, a three-dimensional quantitative structure-activity relationships (3D-QSAR) model was generated based on 34 influenza endonuclease inhibitors. The comparative molecular similarity index analysis (CoMSIA) with a steric, electrostatic and hydrophobic (SEH) model showed the best correlative and predictive capability (q(2) = 0.763, r(2) = 0.969 and F = 174.785), which provided a pharmacophore composed of the electronegative moiety as well as the bulky hydrophobic group. The CoMSIA model was used as a pharmacophore query in the UNITY search of the ChemDiv compound library to give virtual active compounds. The 3D-QSAR model was then used to predict the activity of the selected compounds, which identified three compounds as the most likely inhibitor candidates.

Two cases of intraperitoneal bladder rupture following vaginal delivery

We report two rare cases of isolated spontaneous intraperitoneal bladder rupture following normal vaginal delivery without concomitant uterine rupture. Two primigravidas, aged 32 years and 34 years, presented following vaginal delivery with abdominal distension and acute renal failure. The initial diagnosis in both cases was severe urosepsis. Definitive diagnosis was achieved after 48 hours. Comparison was made with two of the cases found in the literature and all four cases were reviewed. Laparotomy and bladder repair were performed in all patients with no adverse outcome reported. Two of them were diagnosed only during laparotomy. Key diagnostic clinical features were acute renal failure, new-onset ascites and bowel ileus with sepsis. This rare but life-threatening condition is often diagnosed late. Prompt laparotomy and bladder repair are necessary to prevent an adverse outcome.

Clear cell sarcoma of the rectus sheath

We report a 35-year-old Chinese woman with clear cell sarcoma of the rectus sheath aponeurosis presenting as a tender anterior abdominal mass. She was treated with wide local excision. Local recurrence and distant metastasis occurred within two months of the onset of the complaint. Clear cell sarcoma is a rare cancer with a propensity for slow progressive invasion. They occur most commonly in the extremities, and the majority of patients are young adults. This case report demonstrates an unusual site of occurrence for clear cell sarcoma.

Clinics in diagnostic imaging (109). Nocardial adrenal abscess

A 34-year-old man presented with a two-month history of intermittent fever and left loin pain. A large left suprarenal mass was detected on computed tomography and magnetic resonance imaging. Blood pressure, serum electrolytes, serum cortisol and urinary catecholamines were normal. Laparoscopic adrenalectomy was planned but the mass was found to be an isolated adrenal abscess due to Nocardiosis. He was later found to have AIDS. The clinical utility of various imaging modalities and management of adrenal cysts are reviewed.

Evaluation of the Hodge test and the imipenem-EDTA double-disk synergy test for differentiating metallo-beta-lactamase-producing isolates of Pseudomonas spp. and Acinetobacter spp

Gram-negative bacilli with acquired metallo-beta-lactamase (MBL) production have been increasingly reported in some countries, necessitating their detection. The aim of this study was to evaluate the performance of the Hodge test and those of the imipenem (IPM)-EDTA, ceftazidime (CAZ)-mercaptopropionic acid (MPA), and CAZ-sodium mercaptoacetic acid (SMA) double-disk synergy tests (DDSTs). The efficiencies of testing CAZ-resistant and IPM-nonsusceptible isolates were also compared. Strains used for the evaluation were known IMP-1 and VIM-2 MBL-producing isolates and consecutive and CAZ-nonsusceptible isolates of pseudomonads and acinetobacters. The performance of the Hodge test was improved by addition of zinc sulfate (140 microg/disk) to an IPM disk. In DDSTs, EDTA (ca. 1,900 microg) disks were better at detecting MBL-producing strains among pseudomonads, while MPA (3 microl) and SMA (3 mg) disks performed better for acinetobacters. EDTA (ca. 750 microg)-plus-SMA (ca. 2 mg) disks performed better than EDTA, MPA, or SMA disks with both organisms. CAZ-SMA DDSTs failed to detect 22 of 80 (28%) MBL-producing acinetobacters. In conclusion, use of an IPM disk and an EDTA (750 microg)-plus-SMA (2 mg) disk improves performance, and testing IPM-nonsusceptible isolates rather than CAZ-resistant isolates could reduce screening work. Further evaluation of the test is required for the detection of other types of MBL-producing gram-negative bacilli.

Giant mixed-type perinephric liposarcoma

Retroperitoneal fatty tumours are uncommon occurrences in current urologic practice, the differentials being lipomas, liposarcomas and extra-renal angiomyolipomas (AML). We report an unusual case of a 48-year-old Chinese female who presented with a 6.2 kg giant mixed-type liposarcoma in the left perinephric space, invading into the renal cortex and parenchyma. Extirpative surgery with left radical nephrectomy was performed, and histology confirmed liposarcoma with both myxoid and well-differentiated elements. The patient remains well and disease-free at 6-month follow-up. We review the literature on the diagnosis and management of these perinephric lipomatous lesions. We also discuss the diagnostic dilemma in differentiating such malignancies from benign angiomyolipomas in the perinephric area on conventional radiological imaging, and its direct implications with respect to extent of surgery and renal preservation.

Age-related accumulation of Ig V(H) gene somatic mutations in peripheral B cells from aged humans

To investigate age-related alterations in human humoral immunity, we analysed Ig heavy chain variable region genes expressed by peripheral B cells from young and aged individuals. Three hundred and twenty-seven cDNA sequences, 163 micro and 164 gamma transcripts with VH5 family genes, were analysed for somatic hypermutation and VHDJH recombinational features. Unmutated and mutated micro transcripts were interpreted as being from naive and memory IgM B cells, respectively. In young and aged individuals, the percentages of naive IgM among total micro transcripts were 39% and 42%, respectively. D and JH segment usage in naive IgM from aged individuals was similar to that from young individuals. The mutational frequencies of memory IgM were similar in young and aged individuals. gamma transcripts, which are regarded as being from memory IgG B cells, showed a significantly higher mutational frequency (7.6%) in aged than in young individuals (5.8%) (P < 0.01). These findings suggest that VHDJH recombinational diversity was preserved, but that the accumulation of somatic mutations in the IgG VH region was increased in aged humans. The accumulation of somatic mutations in IgG B cells during ageing may imply that an age-related alteration exists in the selection and/or maintenance of peripheral memory B cells.

The effectiveness of anti-retroviral drug therapy for HIV-1 is associated with HIV-1 proviral DNA levels and viral selection

The effect of combination anti-retroviral therapy regimens on HIV-1 proviral DNA levels in peripheral blood mononuclear cells was examined in 12 HIV-1-positive patients, using endpoint dilution polymerase chain reaction and serial cloning, and sequencing of the gag region of HIV-1. The major clone was defined as the most numerous of 10 analysed clones, and observation periods ranged from 8 months to 32 months (mean 19.7 +/- 10.2 months). In five patients (one with primary-stage HIV-1 infection) receiving three anti-retroviral drugs, HIV-1 RNA reduced to undetectable levels (i.e. < or = 100 copies/ml). HIV-1 proviral DNA and the number of major clones reduced in four of these patients. HIV-1 RNA levels reduced, but remained detectable, in five other patients. In the two remaining patients (both receiving two rather than three anti-retroviral drugs), HIV-1 RNA levels increased. These results suggest that the population of major clones may be affected when HIV-1 RNA levels reduce following combination regimens of anti-retroviral therapy.

Genistein prevents nuclear factor-kappa B activation and acute lung injury induced by lipopolysaccharide

Protein tyrosine kinase (PTK) inhibitors have been proposed to reduce lung injury and lethal toxicity. The mechanisms responsible for the effects of PTK inhibitors remain obscure. The purpose of the present study was to examine whether genistein, a specific inhibitor of PTK, inhibits nuclear factor-kappa B (NF-kappaB) activation during acute lung injury induced by lipopolysaccharide (LPS) and, if so, to enumerate the effects of inhibition of NF-kappaB activation on LPS-induced proinflammatory gene products, such as cytokine-inducible neutrophil chemoattractant (CINC) and matrix metalloproteinase-9 (MMP-9), as well as neutrophil influx into the lungs. Intratracheal treatment of rats with LPS (6 mg/kg) resulted in increases in total protein and lactate dehydrogenase activity in bronchoalveolar lavage fluid and activated DNA-binding activity of NF-kappaB in alveolar macrophages and lung tissue. A 2-h pretreatment with genistein (50 mg/kg, intraperitoneally) inhibited the LPS-induced changes in lung injury parameters and the induction of NF-kappaB activation. Furthermore, these inhibitory effects of genistein correlated with a depression of LPS-induced protein tyrosine phosphorylation (approximately molecular masses of 46, 48, and 54 kD) and phosphorylation of Jun N-terminal kinase (JNK) in lung tissue. Genistein also substantially reduced the LPS-induced CINC production and MMP-9 activity and suppressed neutrophil recruitment. These results suggest that genistein attenuates LPS-induced acute lung responses through inhibition of NF-kappaB activation. In addition, NF-kappaB activation appears to be an important mechanism mediating LPS-induced CINC production and MMP-9 activity and resulting neutrophil recruitment associated with acute lung inflammation and injury.

Evidence of B cell clonal expansion in HIV type 1-infected patients

HIV-1 infection results in a gradual decrease in CD4(+) T cell counts and progressive immune deficiency. Increased T cell turnover in HIV-1-infected patients, which can be interpreted as T cell clonal expansion, has been thought to be relevant to its pathogenesis. To investigate whether B cell clonal expansion also occurs in HIV-1-infected patients, we examined the expressed V(H)DJ(H) gene sequences of peripheral B cells in HIV-1-infected patients with hypergammaglobulinemia. Identical V(H)DJ(H) gene rearrangements with additional nucleotide differences in V(H) genes were analyzed as a marker of clonally related B cells. From healthy individuals and HIV-1-uninfected patients with hypergammaglobulinemia, clonally related B cells were detected in none of 10 (0%) and 2 of 10 (20%), respectively. No clonally related B cells were detected in any of the nine HIV-1-infected patients with detectable viral loads and normal Ig levels (0%). In contrast, from 9 of 14 HIV-1-infected patients with hypergammaglobulinemia (64%), clonally related B cells were detected. In addition, no HIV-1-infected patients who exhibited normal Ig levels after antiretroviral therapy had clonally related B cells. These findings suggest that B cell clonal expansion is present in HIV-1-infected patients with hypergammaglobulinemia.

Hepatitis B virus genomes of chronic hepatitis patients do not contain specific mutations related to acute exacerbation

To determine the specific viral variants associated with acute exacerbation of chronic hepatitis from hepatitis B virus (HBV) infection, we analyzed the complete nucleotide sequences of the HBV genome in serial serum samples from two chronic active hepatitis patients who seroconverted from HBeAg to anti-HBe. HBV DNA was amplified by polymerase chain reaction (PCR) and sequenced. A 1896 precore stop codon mutant (G to A at nt 1896) coexisting with the wild sequence was found in both patients prior to seroconversion from HBeAg to anti-HBe. Core promoter mutations at nucleotide positions 1762 (A to T) and 1764 (G to A) were found in both patients throughout the observation period. Mutations were observed in the HBV genome of the two patients at different time points, and there was no correlation between the mutations and liver disease or DNA polymerase levels. The nucleotide divergence rate and the composition of quasispecies in the HBV sequence at the time of acute exacerbation were almost the same as were found at other time points. These results suggest that acute exacerbation does not appear to be caused by a characteristic HBV species. The multiple factors that cause generalized HBV replication activation may contribute to acute exacerbation.

Evaluation of efficiency of screening extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in hospitals where the bacteria are increasingly prevalent

The disk screening methods for extended-spectrum beta-lactamase-producing strains were evaluated. The confirmatory work is reduced significantly in settings such as those in this study, by changing the cefpodoxime breakpoint to < or =20 mm and by not testing cefoxitin-resistant isolates. Cefotaxime and ceftazidime disk screening is reliable, and the laboratory-prepared cefotaxime- and ceftazidime-clavulanic acid disks are stable at -20 degrees C for 12 weeks.

Neonatal intensive care unit outbreak caused by a strain of Klebsiella oxytoca resistant to aztreonam due to overproduction of chromosomal beta-lactamase

Klebsiella oxytoca strains resistant to both aztreonam and ceftriaxone were isolated from six neonates in a neonatal intensive care unit and water reservoirs of two humidifiers attached to the neonatal incubators. These isolates were assumed to be of the same clone because they were characterized by the same antimicrobial susceptibility and pulsed field gel electrophoresis patterns. It was established that the drug resistance was attributed to overproduction of chromosomally encoded Kl beta-lactamase. It was determined that an isolate (K. oxytoca H1) contained a high enzyme concentration (27microg/100microg of protein in enzyme extracts), at least 27 times higher than the control K. oxytoca N1. It was also demonstrated that isolates had a point mutation in the - 35 concensus region of the promotor gene of bla(OXY-2)leading to enzyme overproduction. Outbreaks caused by K1 hyperproducers have not previously been described.

[Effect of highly active antiretroviral therapy (HAART) on hypergammaglobulinemia in HIV infected patients]

To investigate the mechanism of hypergammaglobulinemia in HIV infected patients, the effect of highly active antiretroviral therapy (HAART) on the hypergammaglobulinemia was analyzed. Involved in this study were 34 untreated, 21 HAART-effective (complete response) and 14 HAART-non-effective (partial response) patients. Serum levels of HIV-RNA and gammaglobulin and immunoglobulin (Ig) isotypes were measured. Mean HIV-RNA levels of untreated and partial response patients were 1.6 x 10(4) copies/ml and 0.4 x 10(4) copies/ml, respectively. HIV-RNA levels of all complete response patients were below 4.0 x 10(2) copies/ml. Mean gammaglobulin percentages of untreated, partial response and complete response patients were 24.4%, 21.8% and 17.9%, respectively (p < 0.01 in untreated vs complete response patients). Mean IgG levels in the three groups were 2,489 mg/dl, 1,947 mg/dl and 1,618 mg/dl, respectively (p < 0.001 in untreated vs complete response patients). IgA levels were high in some untreated patients and lower in complete response patients. IgE levels were increased in some untreated and partial response patients, but there was no significant difference among the three groups. These results suggested that the hypergammaglobulinemia found in HIV infected patients was associated with HIV replication. The activation mechanism might differ by Ig isotypes.

Antimicrobial resistance surveillance of bacteria in 1999 in Korea with a special reference to resistance of enterococci to vancomycin and gram-negative bacilli to third generation cephalosporin, imipenem, and fluoroquinolone

The trend of antimicrobial resistance of bacteria isolated from patients in 30 Korean hospitals in 1999 was analyzed with a particular attention to cefotaxime- or fluoroquinolone-resistant gram-negative bacilli, imipenem-resistant Pseudomonas aeruginosa, and vancomycin-resistant enterococci. Adequacy of susceptibility testing, and any change in the frequencies of isolated species were also analyzed. The results showed that only 20% and 30% of hospitals tested the piperacillin-tazobactam and cefoxitin susceptibility of Enterobacteriaceae, respectively, only 24% of hospitals the piperacillin-tazobactam susceptibility of P. aeruginosa, and 17% of hospitals the fusidic acid susceptibility of staphylococci. Among the isolates 26.3% were glucose-nonfermenting gram-negative bacilli, and 34.7% of Enterococcus were Enterococcus faecium. Slight decline of cefotaxime-resistance rate to 20% was noted in Klebsiella pneumoniae, while fluoroquinolone-resistance rate was 68% in Acinetobacter baumannii. The ceftazidime- and imipenem-resistance rates were 17% and 18%, respectively in P. aeruginosa. The vancomycin-resistance rate of E. faecium rose significantly to 15.1%, but the rates varied significantly depending on hospitals suggesting presence of different degree of selective pressure or nosocomial spread. In conclusion, the prevalence of imipenem-resistant P. aeruginosa and the increase of vancomycin-resistant E. faecium were the particularly worrisome phenomena observed in this study.

Solid phase synthesis of carbocyclic l-2'-deoxynucleosides

[reaction: see text] Carbocyclic L-2'deoxynucleosides 17 were synthesized on solid phase in four steps from the appropriately protected intermedate 11. The Mitsunobu reaction was used as a condensation method between the carbocyclic moiety and heterocyclic bases. The regioselectivity of the carbocyclic nucleosides was compared between the solid and solution phase syntheses.

2'-Ribose-ferrocene oligonucleotides for electronic detection of nucleic acids

We have synthesized two novel phosphoramidites with a ferrocenyl moiety at the 2'-ribose position linked through a butoxy linker. Using automated DNA/RNA synthesis techniques, oligonucleotides containing ferrocene at various positions were prepared and characterized by HPLC, MALDI-TOF mass spectrometry, and electrochemistry. Thermal stability studies of the ferrocene-modified DNA duplexes revealed that introduction of one or two ferrocenyl complexes does not result in an observed change of the T(m) values of the corresponding DNA duplexes when compared to the nonmodified hybrids. These data indicate that the introduction of a ferrocenyl group at the 2'-position of the ribose ring containing either a purine or pyrimidine base has no effect on the stability of the modified DNA. The electrochemical behavior of the ferrocene-containing DNA was examined by cyclic voltammetry. The modified 2'-ferrocene-oligonucleotides are electrochemically active and can be used as signaling probes for the electronic detection of nucleic acids on bioelectronic sensors.

A two year global evaluation of the susceptibility of Candida species to fluconazole by disk diffusion

The in-vitro activity of fluconazole against 46,831 yeast isolates collected over a two-year period from 57 laboratories in 33 countries worldwide was assessed using a disc diffusion method. Candida albicans was the organism isolated most frequently, accounting for 68.6% of the total number of isolates. C. glabrata, C. tropicalis, C parapsilosis and C. krusei and Cryptococcus neoformans represented 9.9, 4.7, 4.3, 1.9, and 1.4% of isolates respectively during the 2 year period and rates varied markedly between countries. In 1999 data blood isolates represented 4.9% of all isolates and intensive care unit isolates represented 9.9%. In both the 1998 and 1999 data, 99% of C. albicans were fully susceptible (S) to fluconazole, and 95.6% of all species of yeasts tested were S or susceptible-dose dependent (S-DD) to fluconazole. No emerging trends of resistance were noted with any of the Candida spp. tested as 96% of all isolates retained susceptibility (S or S-DD) to this agent.

Understanding the mode of action of L-nucleosides as antiviral agents: a molecular modeling approach

Computer modeling studies have been performed on the several pairs of D- and L-nucleoside inhibitors with the HIV-1 RT model. Additionally, clinically important M184V mutation, which confers the viral resistance against 3TC and FTC, were studied by the same modeling system.

Present situation of antimicrobial resistance in Korea

Resistance of bacteria to antimicrobial agents is a worldwide concern. In Korea, resistant bacteria are more prevalent than in other industrialized countries. Methicillin-resistant Staphylococcus aureus, erythromycin-resistant Streptococcus pyogenes, penicillin non-susceptible pneumococci, beta-lactamase-producing gonococci, extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae, class C beta-lactamase-producing E. coli, fluoroquinolone-resistant E. coli, and aminoglycoside-resistant Acinetobacter baumannii and Pseudomonas aeruginosa are examples of resistant bacteria prevalent in Korea, and their presence suggests a high level of antimicrobial selective pressure and the nosocomial spread of resistant bacteria. Recently observed rapid increases in the incidence of vancomycin-resistant Enterococcus faecium and carbapenem-resistant P. aeruginosa present new threats in Korea.

Bioelectronic detection of point mutations using discrimination of the H63D polymorphism of the Hfe gene as a model

BACKGROUND

A bioelectronic detection platform has recently been developed that facilitates the detection and characterization of nucleic acids. The DNA chip platform is compatible with homogeneous assays because separate labeling and wash steps are not required. A one-step, bioelectronic detection assay was developed to genotype patient samples with respect to the H63D polymorphism of the Hfe gene, associated with hereditary hemochromatosis.

METHODS AND RESULTS

Electrode arrays were modified with DNA capture probes that were perfectly matched to the wild-type or mutant allele of H63D. Amplicons containing the polymorphic site were hybridized with the capture probes on the electrode arrays in the presence of electronically labeled reporter (signaling) probes. Voltammetric analysis of the electrode arrays was conducted first at ambient temperature and then at elevated temperature. The electronic signal was preferentially diminished at elevated temperature from electrodes that hybridized with mismatched target amplicons.

CONCLUSION

An assay for bioelectronic genotyping of the H63D polymorphism was developed and used with six patient specimens to show the feasibility of this system as a model for point mutation detection.