A cautionary note to hepatitis B e antigen (HBeAg)-negative test results in pregnant women in an area prevalent of HBeAg-negative chronic hepatitis B.

Maternal hepatitis B e Antigen (HBeAg) positivity poses a risk for hepatitis B virus (HBV) mother-to-child transmission (MTCT). In resource-constrained settings, HBeAg testing is recommended as an alternative to HBV DNA testing to establish antiviral prophylaxis eligibility. Nevertheless, the high prevalence of HBeAg-negative chronic hepatitis B (e-CHB) in many countries should not be overlooked. We studied HBV characteristics and explored the potential MTCT risk among HBeAg-negative/HBsAg-positive expectant mothers in an area prevalent of e-CHB. Among 1348 pregnant mothers screened for HBV infection, 81 (6.0%) were HBsAg-positive. These women were examined for HBeAg, HBV DNA, and cord blood HBV DNA. Sixteen (19.8%) of the HBsAg-positive mothers were HBeAg-positive, whereas 65 (80.2%) were HBeAg-negative, including eight inactive carriers (HBsAg <100 IU/ml, HBV DNA ≤ 2000 IU/ml, and ALT < 40 IU/L). Of the remaining 57 HBeAg-negative mothers, ten revealed HBV Basal Core Promoter or Precore mutations, with three having high viremia (HBV DNA > 200 000 IU/mL), which is associated with a high MTCT risk and therefore qualifies them for antiviral prophylaxis. This pilot study provides a cautionary note to the interpretation of negative HBeAg test results when determining eligibility for MTCT antiviral prophylaxis in situations with limited resources and in regions where e-CHB is prevalent.

Evaluation of thermal plasma process for treatment disposal of solid radioactive waste.

The management of radioactive waste is a worldwide activity based on the guidelines of the International Atomic Energy Agency (IAEA), and all stages of management require scientifically proven methods for possible deployment. The management of radioactive waste is a huge challenge due to the high risk in the collection, gathering, transport, handling, and storage. In this study, a thermal plasma treatment process was evaluated for its efficiency to process solid radioactive waste. Experiments were carried out with the application of stable isotopes of Lead, Iodine, Cobalt, and Cesium. After the thermal plasma treatments, the slag and the residual gas were analyzed to verify the influence of process time and discharge power on the efficiency of the process. The treatment for 25 min and 10 kW was sufficient to reduce the mass by 50% of the slag. When the applied power was increased to 15 kW, an expressive reduction in the treatment time (10 min) was able to promote the same mass reduction. The results indicated that the treatment of radioactive waste by thermal plasma is a promising method to manage and reduce the mass and volume for the final disposal.

LABEC, the INFN ion beam laboratory of nuclear techniques for environment and cultural heritage.

The LABEC laboratory, the INFN ion beam laboratory of nuclear techniques for environment and cultural heritage, located in the Scientific and Technological Campus of the University of Florence in Sesto Fiorentino, started its operational activities in 2004, after INFN decided in 2001 to provide our applied nuclear physics group with a large laboratory dedicated to applications of accelerator-related analytical techniques, based on a new 3 MV Tandetron accelerator. The new accelerator greatly improved the performance of existing Ion Beam Analysis (IBA) applications (for which we were using since the 1980s an old single-ended Van de Graaff accelerator) and in addition allowed to start a novel activity of Accelerator Mass Spectrometry (AMS), in particular for 14C dating. Switching between IBA and AMS operation became very easy and fast, which allowed us high flexibility in programming the activities, mainly focused on studies of cultural heritage and atmospheric aerosol composition, but including also applications to biology, geology, material science and forensics, ion implantation, tests of radiation damage to components, detector performance tests and low-energy nuclear physics. This paper describes the facilities presently available in the LABEC laboratory, their technical features and some success stories of recent applications.

Seroepidemiology of HBV infection among health-care workers in South Sulawesi, Indonesia.

BACKGROUND: Hepatitis B virus (HBV) infection is a world health problem with an estimated 257 million chronically infected people. Indonesia, with 7.1% prevalence of hepatitis B surface antigen (HBsAg), is classified as a moderately endemic country. Healthcare workers (HCWs) are at high occupational risk for HBV infection and potentially becoming transmitters for further infections. In Indonesia, the extent of hepatitis B among HCWs and specific control strategy are not available. This study evaluated the seroprevalence of HBV infection and associated risk factors in HCWs from four areas in South Sulawesi, Indonesia. METHODS: A total of 467 HCWs (median age 28 years, male/female 89/378) were recruited. All HCWs were classified into three age groups (< 20-29, 30-39, and ≥ 40 years old), three work types (administration, non-intervention, and intervention), and three service periods (< 5, 5-9, and ≥ 10 years). Data on socio-demographic characteristics and risk factors were obtained by questionnaire and serum samples were tested for HBV markers (HBsAg, its antibody [anti-HBs], and antibody to core antigen [anti-HBc]. Chi-square or Fisher's exact test was used to determine differences in categorical variables, while risk factors were reported as odds ratios (OR). RESULTS: The prevalence of current HBV infection (HBsAg+), exposure to HBV (anti-HBc+), and immunity to HBV (anti-HBs+) was 6.2, 19.2, and 26.1%, respectively. Two thirds (66.17%) of all HCWs did not express any of HBV markers. In relation to the age groups, intervention work-type, and service period of HCWs, increasing trends were observed in the exposure to HBV (p < 0.001, p < 0.001, and p < 0.010, respectively) and the immunity to HBV by natural infection (HBsAg-, anti-HBc+, anti-HBs+) (p = 0.004, p < 0.001, and p < 0.010, respectively). Needlestick injury contributed the highest risk factor (OR = 1.71; 95% CI: 1.05-2.77; p = 0.029) for infection acquisition, which mostly occurred in the intervention group (p = 0.046). CONCLUSION: Exposure to HBV showed significant association with HCWs' age, work type, and service period. Needlestick injury was the highest risk factor for the acquisition of HBV, with highest events in the intervention work-type. Two thirds of HCWs were still susceptible to HBV infection. Intervention strategies at the national level are required to mount prevention, control, and management of HBV infection in HCWs.

Refractive index variation in a free-standing diamond thin film induced by irradiation with fully transmitted high-energy protons.

Ion irradiation is a widely employed tool to fabricate diamond micro- and nano-structures for applications in integrated photonics and quantum optics. In this context, it is essential to accurately assess the effect of ion-induced damage on the variation of the refractive index of the material, both to control the side effects in the fabrication process and possibly finely tune such variations. Several partially contradictory accounts have been provided on the effect of the ion irradiation on the refractive index of single crystal diamond. These discrepancies may be attributable to the fact that in all cases the ions are implanted in the bulk of the material, thus inducing a series of concurrent effects (volume expansion, stress, doping, etc.). Here we report the systematic characterization of the refractive index variations occurring in a 38 µm thin artificial diamond sample upon irradiation with high-energy (3 MeV and 5 MeV) protons. In this configuration the ions are fully transmitted through the sample, while inducing an almost uniform damage profile with depth. Therefore, our findings conclusively identify and accurately quantify the change in the material polarizability as a function of ion beam damage as the primary cause for the modification of its refractive index.

Intracellular distribution and stability of a luminescent rhenium(i) tricarbonyl tetrazolato complex using epifluorescence microscopy in conjunction with X-ray fluorescence imaging.

Optical epifluorescence microscopy was used in conjunction with X-ray fluorescence imaging to monitor the stability and intracellular distribution of the luminescent rhenium(i) complex fac-[Re(CO)3(phen)L], where phen = 1,10-phenathroline and L = 5-(4-iodophenyl)tetrazolato, in 22Rv1 cells. The rhenium complex showed no signs of ancillary ligand dissociation, a conclusion based on data obtained via X-ray fluorescence imaging aligning iodine and rhenium distributions. A diffuse reticular localisation was detected for the complex in the nuclear/perinuclear region of cells, by either optical or X-ray fluorescence imaging techniques. X-ray fluorescence also showed that the rhenium complex disrupted the homeostasis of some biologically relevant elements, such as chlorine, potassium and zinc.

Unprecedented staining of polar lipids by a luminescent rhenium complex revealed by FTIR microspectroscopy in adipocytes.

Fourier transform infrared (FTIR) microspectroscopy and confocal imaging have been used to demonstrate that the neutral rhenium(i) tricarbonyl 1,10-phenanthroline complex bound to 4-cyanophenyltetrazolate as the ancillary ligand is able to localise in regions with high concentrations of polar lipids such as phosphatidylethanolamine (PE), sphingomyelin, sphingosphine and lysophosphatidic acid (LPA) in mammalian adipocytes.

Chronic hepatitis B in pregnant women: is hepatitis B surface antigen quantification useful for viral load prediction?

BACKGROUND: New cases of hepatitis B virus (HBV) infection continue to occur worldwide. Most of these are due to mother-to-child transmission (MTCT), with maternal viraemia as the most important contributing factor. The hepatitis B surface antigen (HBsAg) level, which correlates positively with viral load, has been used for treatment monitoring in chronic hepatitis B. This study evaluated the usefulness of quantitative HBsAg for viral load prediction in HBsAg-positive pregnant women. METHODS: A total of 943 pregnant women in Makassar, Indonesia, were screened for HBsAg. Sixty-four women were HBsAg-positive and investigated. HBsAg level and hepatitis B e antigen (HBeAg)/hepatitis B e antibody (anti-HBe) status were determined serologically. Viral load was measured by real-time PCR. HBV DNA was sequenced and analysed for identification of genotype and basal core promoter (BCP)/precore (PC) mutations. RESULTS: Of 64 subjects, 12 (18.8%) were HBeAg-positive and 52 (81.3%) were HBeAg-negative. HBsAg and HBV DNA levels were significantly higher in the HBeAg-positive group (p<0.001). HBsAg and HBV DNA levels were positively correlated in the HBeAg-positive group (r = 0.659; p=0.02), but not in the HBeAg-negative group (r=0.194; p=0.168). Low HBsAg levels (<3.0 log10 IU/ml) corresponded with HBV DNA levels<6.0 log10 IU/ml (r=0.404; p=0.001), a recognized threshold for MTCT. Genotype C was more prevalent than genotype B, but not associated with HBsAg level, viral load, or HBeAg status. Two-thirds of HBeAg-negative subjects with high HBV DNA levels harboured BCP (A1762T/G1764A) and/or PC (G1896A) variants. CONCLUSIONS: HBsAg levels provide a good viral load predictor in HBeAg-positive but not HBeAg-negative pregnant women. The HBeAg-negative group had a frequent occurrence of BCP/PC variants, which may have contributed to the lack of correlation observed. Samples with a low HBsAg level, which is associated with a low risk of MTCT, do not require HBV DNA measurement.

Complex refractive index variation in proton-damaged diamond.

An accurate control of the optical properties of single crystal diamond during microfabrication processes such as ion implantation plays a crucial role in the engineering of integrated photonic devices. In this work we present a systematic study of the variation of both real and imaginary parts of the refractive index of single crystal diamond, when damaged with 2 and 3 MeV protons at low-medium fluences (range: 10(15) - 10(17) cm(-2)). After implanting in 125 × 125 µm(2) areas with a scanning ion microbeam, the variation of optical pathlength of the implanted regions was measured with laser interferometric microscopy, while their optical transmission was studied using a spectrometric set-up with micrometric spatial resolution. On the basis of a model taking into account the strongly non-uniform damage profile in the bulk sample, the variation of the complex refractive index as a function of damage density was evaluated.

Heterogeneity of Mycobacterium tuberculosis strains in Makassar, Indonesia.

SETTING: Patients with suspected pulmonary tuberculosis (TB) visiting government TB diagnostic and treatment centres in Makassar City, South Sulawesi Province, Indonesia, from February to October 2008 were included in the study. OBJECTIVE: To determine the distribution of Mycobacterium tuberculosis genotypes in Makassar. DESIGN: Cross-sectional study. Spoligotyping, mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) and principal genetic grouping (PGG) were used to genotype the M. tuberculosis clinical isolates. RESULTS: Among 179 isolates derived from pulmonary TB patients, distribution of spoligotypes comprised the East Africa-Indian (30.2%), T (17.9%), H (12.3%) and Beijing (9.5%) lineages. Other lineages found in smaller proportions were the Latin American-Mediterranean, MANU, S and X lineages. Nineteen isolates (10.6%) could not be grouped into any of the reported lineages or shared types. Single nucleotide polymorphism analysis of katG(463) and gyrA(95) grouped these isolates primarily into PGG1 (9/19, 47%). CONCLUSION: Only a few genetically identical clustered isolates were identified within the 9-month study period, and most isolates were genetically diverse. Furthermore, 15 spoligopatterns identified in our study have not been reported previously. To our knowledge, this is the first comprehensive study describing genotypes of M. tuberculosis clinical isolates in Sulawesi.

Drug resistance among tuberculosis patients attending diagnostic and treatment centres in Makassar, Indonesia.

SETTING: Government tuberculosis (TB) diagnostic and treatment centres, Makassar, Indonesia. OBJECTIVE: To determine the proportions and patterns of resistance to commonly used TB drugs (isoniazid [INH], rifampicin, ethambutol and streptomycin) among pulmonary TB patients and assess potential risk factors for drug resistance. DESIGN: Cross-sectional study. RESULTS: Of 657 recruited patients, 234 were culture-positive. Drug susceptibility testing (DST) results were available for 216 patients. Among these, 197 were infected with Mycobacterium tuberculosis complex (145 new and 52 previously treated). Isolates from 89 new (61.4%) and 31 previously treated (59.6%) patients were susceptible to all four drugs. Resistance to INH was high among both patient groups (28.3% of new vs. 34.6% of previously treated). Multidrug-resistant TB (MDR-TB) cases accounted for respectively 4.1% and 19.2% of these patients. Resistance to >2 drugs was high among previously treated patients (19.2%). MDR-TB cases were more likely to have a history of excess alcohol use (adjusted OR 4.01, 95%CI 1.28-12.53) and previous TB treatment (adjusted OR 6.28, 95%CI 2.01-19.64). CONCLUSIONS: Regardless of previous treatment history, many culture-positive TB patients were infected with INH-resistant isolates, and a significant proportion of previously treated patients were infected with MDR-TB. Treating culture-positive TB patients, especially previously treated patients, based on DST results should therefore be considered.

Epoxy composite with milimetric carbon nanotubes.

Composite of multi-walled carbon nanotubes (MWCNT) and epoxy resin DGEBA were obtained with DDM hardener. The MWCNT were synthesized with length of millimeters by camphor/ferrocene pyrolysis. Different cure temperatures of DGEBA/DDM with addition of up to 1% MWCNT were studied to evaluate eventual changes in cure kinetics by differential scanning calorimetry (DSC). No change was detected in glass transition temperature with insertion of MWCNT although the cure enthalpy has been reduced.

Thermal annealing and electrochemical purification of multi-walled carbon nanotubes produced by camphor/ferrocene mixtures.

Multi-walled carbon nanotubes (MWCNT) were obtained by pyrolysis of camphor/ferrocene mixtures, at different concentrations of ferrocene, on quartz, polished silicon and carbon felt substrates. A detailed study by electron microscopy, Raman spectroscopy, X-ray diffraction and thermogravimetric analysis was carried out to determine the purity degree of MWCNTs. Thermal annealing under vacuum and electrochemical purification were used for iron removal. The thermal annealing brings improvement on crystalline structure of MWCNTs, besides iron elimination from internal structure of the tubes, while the electrochemical treatments remove efficiently the iron from MWCNT surface.

Evidence of light guiding in ion-implanted diamond.

We demonstrate the feasibility of fabricating light-waveguiding microstructures in bulk single-crystal diamond by means of direct ion implantation with a scanning microbeam, resulting in the modulation of the refractive index of the ion-beam damaged crystal. Direct evidence of waveguiding through such buried microchannels is obtained with a phase-shift micro-interferometric method allowing the study of the multimodal structure of the propagating electromagnetic field. The possibility of defining optical and photonic structures by direct ion writing opens a range of new possibilities in the design of quantum-optical devices in bulk single-crystal diamond.

Possible common central pathway for resistin and insulin in regulating food intake.

AIM: Adipose tissue has been the object of intense research in the field of obesity and diabetes diseases in the last decade. Examination of adipocyte-secreted peptides led to the identification of a unique polypeptide, resistin (RSTN), which has been suggested as a link between obesity and diabetes. RSTN plays a clearly documented role in blocking insulin (INS)-induced hypoglycaemia. As brain injection of INS affects feeding behaviour, we studied the possible interaction between INS and RSTN in food-deprived rats, measuring effects on food intake. In addition, we examined how RSTN might affect neuropeptide Y (NPY)-induced feeding, as studies have shown that rat RSTN can interfere with the NPY system. METHODS: Overnight food-deprived rats were injected into the third brain ventricle (3V) with either INS (10 or 20 mUI), RSTN (0.1-0.4 nmol/rat), or saline before access to food. Another group of rats was injected into the 3V with RSTN alone, NPY alone or RSTN plus NPY. Their food intake and body weight were measured. RESULTS: Our results confirm the hypophagic effect of RSTN on food deprivation-induced food intake, and more importantly, show that RSTN neither potentiates nor blocks the effects of INS on food intake, but does reduce the hyperphagic effect of NPY. CONCLUSION: The observation that RSTN does not modify feeding INS-induced hypophagia, but does influence NPY-induced feeding, points to the possibility that RSTN may be involved in control of food intake through an NPY-ergic mechanism as INS.

Effect of novel nociceptin/orphanin FQ-NOP receptor ligands on ethanol drinking in alcohol-preferring msP rats.

Activation of the NOP receptor by the endogenous ligand nociceptin/orphanin FQ (N/OFQ) reduces alcohol consumption in genetically selected alcohol-preferring Marchigian Sardinian (msP) rats. The present study evaluated the effect of three newly synthesized peptidergic and one brain-penetrating heterocyclic NOP receptor agonists on alcohol drinking in the two bottle choice paradigm. MsP rats were intracerebroventricularly (ICV) injected with the NOP receptor agonists OS-462 (0.5 and 1.0 microg), UFP-102 (0.25 and 1.0 microg) or UFP-112 (0.01 and 0.05 microg), or with Ro 64-6198 (0.3 and 1.0 mg/kg) given intraperitoneally (i.p.) and tested for 10% alcohol consumption. Results showed decreased alcohol consumption after treatment with all three peptidergic NOP receptor agonists (OS-462, UFP-102 and UFP-112). OS-462 (at the 1.0 microg dose) and UFP-102 (at the 0.25 microg dose) induced a significant increase in food intake as well. Surprisingly, Ro 64-6198 was ineffective at the 0.3 mg/kg dose, whereas it increased ethanol and food consumption at the 1.0 mg/kg dose. Pre-treatment with the selective mu-receptor antagonist naloxone (0.5 mg/kg, i.p.) reduced these effects of 1.0 mg/kg of Ro 64-6198. These findings confirm that activation of brain NOP receptors reduces alcohol drinking in msP rats and demonstrate that OS-462, UFP-102 and UFP-112 act as potent NOP receptor agonists. On the other hand, Ro 64-6198 increased alcohol drinking, an effect probably induced by a residual agonist activity of this compound at mu-opioid receptors. Overall, the results indicate that OS-462, UFP-102 and UFP-112 may represent valuable pharmacological tools to investigate the functional role of the brain N/OFQ system.

Variation at the rat Crhr1 locus and sensitivity to relapse into alcohol seeking induced by environmental stress.

Alcoholism is a chronic relapsing disorder with substantial heritability. Uncovering gene-environment interactions underlying this disease process can aid identification of novel treatment targets. Here, we found a lowered threshold for stress-induced reinstatement of alcohol seeking in Marchigian-Sardinian Preferring (msP) rats genetically selected for high alcohol preference. In situ hybridization for a panel of 20 stress-related genes in 16 brain regions was used to screen for differential gene expression that may underlie this behavioral phenotype. An innate up-regulation of the Crhr1 transcript, encoding the corticotropin-releasing hormone receptor 1 (CRH-R1), was found in several limbic brain areas of msP rats genetically selected for high alcohol preference, was associated with genetic polymorphism of the Crhr1 promoter, and was accompanied by increased CRH-R1 density. A selective CRH-R1 antagonist (antalarmin, 10-20 mg/kg) was devoid of effects on operant alcohol self-administration in unselected Wistar rats but significantly suppressed this behavior in the msP line. Stress-induced reinstatement of alcohol seeking was not significantly affected by antalarmin in Wistar rats but was fully blocked in msP animals. These data demonstrate that Crhr1 genotype and expression interact with environmental stress to reinstate alcohol-seeking behavior.

Quantitative detection of Salmonella enterica serovar Typhi from blood of suspected typhoid fever patients by real-time PCR.

We quantified the gene copies from Salmonella enterica serovar Typhi (S. Typhi) in the blood of patients suspected of having typhoid fever by using TaqMan-based real-time PCR (TaqMan assay) to target the S. Typhi flagellin gene in genomic DNAs isolated from blood samples. Of 55 blood samples taken from suspected typhoid fever patients, eight blood samples with a positive blood culture had S. Typhi loads ranging from 1.01 x 10(3) to 4.35 x 10(4) copies/ml blood, and from 47 blood samples with negative blood culture, there were 40 (85.1%) TaqMan assay-positive samples with loads ranging from 3.9 to 9.9 x 10(2) copies/ml blood. In the present study, the TaqMan assay detected more than 10(3) copies/ml blood of S. Typhi in all of the blood culture-positive samples, whereas less than 10(3) copies/ml blood of S. Typhi were detected in the blood culture-negative samples. Our findings suggest that a TaqMan assay may be useful for assessing S. Typhi loads, especially in cases of suspected typhoid fever with negative results from the standard blood culture test.

[Minimally invasive video-assisted thyroidectomy--techniques and results over 4 years of experience (1999-2002)]. / Tiroidectomia video-assistita minimamente invasiva (Mivat)--cenni di tecnica an e risultati di 4 anni di esperienza (Analisi della casistica 1999-2002).

INTRODUCTION: This study reviews four years of Minimally Invasive Video Assisted Thyroidectomy (MIVAT) technique and compares the results to those of traditional thyroid surgery. MATERIALS AND METHODS: Between 1999 and 2002, a series of 427 patients were submitted to MIVAT at our Department. Selection criteria were: thyroid nodule maximum diameter of 3.5 cm, total thyroid volume under 25 cc, no signs associated thyroiditis, diagnosis of benign thyroid disease or "low risk" thyroid tumor, no evidence of nodal disease of the neck. RESULTS: We operated on 362 females and 65 males and the mean age of the population was 39.6 years (range 10-77). A total thyroidectomy was performed in 208 cases, and 219 patients underwent a single-side procedure. Mean operative time was 30.4 minutes for lobectomy (range 20-140 minutes) and 50.2 for total thyroidectomy (range 35-140). Complications were represented by definitive recurrent nerve palsy in 3 patients (0.7%) and one case of definitive hypoparathyroidism (0.4%). A wound infection is reported in 3 cases and we had no major bleeding that required surgical revision. A conversion to open procedure was performed in 5 cases (1.2%); mean hospitalisation was 1.28 days (range: 1-4). CONCLUSIONS: This series demonstrates that MIVAT is not different to conventional open surgery in terms of complications, radicality of the procedure and operative time. Moreover, even if not statistically proved, MIVAT appears to offer some advantages in terms of cosmetic results and postoperative pain. In conclusion, we believe that MIVAT is a perfectly reproducible and safe technique for both benign and low-risk malignant thyroid disease, when correct indications are strictly followed.

Finite-size effects in single chain magnets: an experimental and theoretical study.

The problem of finite-size effects in s=1/2 Ising systems showing slow dynamics of the magnetization is investigated introducing diamagnetic impurities in a Co2+-radical chain. The static magnetic properties have been measured and analyzed considering the peculiarities induced by the ferrimagnetic character of the compound. The dynamic susceptibility shows that an Arrhenius law is observed with the same energy barrier for the pure and the doped compounds while the prefactor decreases, as theoretically predicted. Multiple spin reversal has also been investigated.