Seismic risk of critical facilities in the Dominican Republic: case study of school buildings

The island of Hispaniola, shared by the Dominican Republic and Haiti, is located in a subduction zone between the North America plate and the Caribbean plate. In addition, there are 13 geological faults in the interior of the island, some of which have shown the potential to generate earthquakes of magnitude 7.5 and higher. Thus, the whole island is considered to be a high seismic risk region. In the past 100 years, several earthquakes have affected both parts of the island. In the case of the Dominican Republic, two earthquakes stand out: a magnitude 8.1 earthquake on August 4, 1946, north of the Samaná Province, which caused a tsunami, soil liquefaction, and the loss of about 100 lives, and a magnitude 6.5 earthquake on September 22, 2003, in the city of Puerto Plata, which caused significant damage for infrastructures. Among the observed effects, the partial and total collapse of several school buildings had a remarkable impact on local communities. In addition to the high seismic risk, a large part of the national infrastructure may exhibit high vulnerability to earthquakes because the seismic regulations had been the same for 32 years, namely from 1979 to 2011. During these three decades, thousands of structures were built nationwide, including essential facilities such as hospitals and schools. Considering that the current student population in public schools in the Dominican Republic is over 2 million, with the majority attending buildings that were designed with the 1979 seismic code and which proved to be highly vulnerable during the Puerto Plata earthquake, it is vital to take measures that reduce the risk and minimize potential earthquake damage to school buildings. In this context, the Technological Institute of Santo Domingo (INTEC) has undertaken recently a project with the main objective to assess the seismic vulnerability of 22 schools located in the San Cristóbal Province, in the south of the Dominican Republic. The latter schools were all built prior to the adoption of the current updated seismic code. This paper presents the results of the assessment of the Fernando Cabral Ortega School. Although only the results of a single RC building are presented, the response of such structure can be considered representative of a portfolio of existing schools in Dominican Republic.

Molecular methods for cost-efficient monitoring of HAB (harmful algal bloom) dinoflagellate resting cysts

Cyst abundance and identity are essential for understanding and predicting blooms, and for assessing the dispersal of toxic target dinoflagellate species by natural or human mediated ways, as with ballast waters. The aim of this study was to apply rapid, specific and sensitive qPCR assays to enumerate toxic dinoflagellate cysts in sediment samples collected from Adriatic harbours. The molecular standard curves of various target species allowed obtaining the rDNA copy number per cyst. The analytical sensitivity for specific standard curves was determined to be 2 or 10 rDNA copies per reaction. The abundance varied in the range of 1-747 dinoflagellate cysts g^-1 dry weight. The assays showed greater sensitivity as compared to counts by light microscopy. This qPCR method revealed a powerful tool for the quantification of cysts from toxic dinoflagellate resting stages in sediment samples from Adriatic ports.

Effectiveness of different therapeutic strategies in preventing diverticulitis recurrence

BACKGROUND

Colonic diverticulitis shows a high recurrence rate.

AIMS

To assess the efficacy of three different therapeutic strategies in preventing diverticulitis recurrence.

MATERIALS AND METHODS

One hundred thirty patients suffering from Acute Uncomplicated Diverticulitis (AUD) (81 males, 49 females, mean age 64.71 years, range 40-85) were prospectively assessed. After obtaining remission, considered present when both endoscopic and histological damage were absent, the patients were treated with mesalazine 1.6 g/day (59 patients, group A), or rifaximin 800 mg/day for 7 days every month (52 patients, group B). Clinical, endoscopic and histological follow-up was performed after 6, 12 and thereafter every 12 months after diagnosis of AUD.

RESULTS

Seven patients were excluded from final evaluation because they were lost to follow-up. Fifty-five group A patients and 49 group B patients patients were available for the final assessment at the end of a 24-month follow-up. Sustained remission was significantly higher in group A with respect to group B.

CONCLUSIONS

Patients taking mesalazine have lower risk of diverticulitis recurrence than patients taking rifaximin because of the lower prevalence of persisting endoscopic and histological inflammation.

Performance evaluation of paediatric propofol pharmacokinetic models in healthy young children

BACKGROUND

The performance of eight currently available paediatric propofol pharmacokinetic models in target-controlled infusions (TCIs) was assessed, in healthy children from 3 to 26 months of age.

METHODS

Forty-one, ASA I-II children, aged 3-26 months were studied. After the induction of general anaesthesia with sevoflurane and remifentanil, a propofol bolus dose of 2.5 mg kg(-1) followed by an infusion of 8 mg kg(-1) h(-1) was given. Arterial blood samples were collected at 1, 2, 3, 5, 10, 20, 40, and 60 min post-bolus, at the end of surgery, and at 1, 3, 5, 30, 60, and 120 min after stopping the infusion. Model performance was visually inspected with measured/predicted plots. Median performance error (MDPE) and the median absolute performance error (MDAPE) were calculated to measure bias and accuracy of each model.

RESULTS

Performance of the eight models tested differed markedly during the different stages of propofol administration. Most models underestimated propofol concentration 1 min after the bolus dose, suggesting an overestimation of the initial volume of distribution. Six of the eight models tested were within the accepted limits of performance (MDPE<20% and MDAPE<30%). The model derived by Short and colleagues performed best.

CONCLUSIONS

Our results suggest that six of the eight models tested perform well in young children. Since most models overestimate the initial volume of distribution, the use for TCI might result in the administration of larger bolus doses than necessary.

Influence of obesity on propofol pharmacokinetics: derivation of a pharmacokinetic model

BACKGROUND

The objective of this study was to develop a pharmacokinetic (PK) model to characterize the influence of obesity on propofol PK parameters.

METHODS

Nineteen obese ASA II patients undergoing bariatric surgery were studied. Patients received propofol 2 mg kg(-1) bolus dose followed by a 5-20-40-120 min, 10-8-6-5 mg kg(-1) h(-1) infusion. Arterial blood samples were withdrawn at 1, 3, 5 min after induction, every 10-20 min during propofol infusion, and every 10-30 min for 2 h after stopping the propofol infusion. Arterial samples were processed by high-performance liquid chromatography. Time-concentration data profiles from this study were pooled with data from two other propofol PK studies available at http://www.opentci.org. Population PK modelling was performed using non-linear mixed effects model.

RESULTS

The study involved 19 obese adults who contributed 163 observations. The pooled analysis involved 51 patients (weight 93 sd 24 kg, range 44-160 kg; age 46 sd 16 yr, range 25-81 yr; BMI 33 sd 9 kg m(-2), range 16-52 kg m(-2)). A three-compartment model was used to investigate propofol PK. An allometric size model using total body weight (TBW) was superior to all other models investigated (linear TBW, free fat mass, lean body weight, normal fat mass) for all clearance parameters. Variability in V2 and Q2 was reduced by a function showing a decrease in both parameters with age.

CONCLUSIONS

We have derived a population PK model using obese and non-obese data to characterize propofol PK over a wide range of body weights. An allometric model using TBW as the size descriptor of volumes and clearances was superior to other size descriptors to characterize propofol PK in obese patients.

Safety and effectiveness of infliximab for inflammatory bowel diseases in clinical practice

BACKGROUND AND OBJECTIVES

Our aim was to assess the efficacy and safety of infliximab (IFX) in clinical practice in three Primary Care, Hospital Centers.

MATERIAL AND METHODS

From September 2004 to December 2008 62 patients (28 males, 34 females, mean age 30.25 years, range 15-55 years), affected by ulcerative colitis (UC) (23 pts) or by Crohn's disease (CD) (39 patients) were treated. Clinical efficacy, safety, mucosal healing and quality of life were assessed both in UC and CD.

RESULTS

A total of 746 infusions were performed. IFX was administered for a mean of 26 months (range 8-44 months). 33/39 (84.61%) pts with CD were in remission under treatment with IFX for a mean time of 19 months (range 12-44 months). Mean Crohn Disease Activity Index (CDAI) score decreased from 295 (range 258-346) to 136 (range 98-136) (p < 0.005). Inflammatory Bowel Disease Quality of Life (IBDQL) improved from 48 (at entry) to 198 (at the end of the study) (p < 0.005). 20/23 (86.95%) patients with UC were in remission under treatment with IFX for a mean of 18 months (range 8-34 months). Mean Disease Activity Index (DAI) decreased from 11 (range 9-12) to < 3 (range 2-3) (p < 0.05). Mean Mayo Subscore for Endoscopy decreased from 3 to < 1 (range 0-1). IBDQL improved from 56 (at entry) to 194 (at the end of the study) (p < 0.005). Only 5 patients (8.06%) experienced side-effects.

CONCLUSIONS

Long-term outpatients treatment with IFX seems to be safe and effective in managing patients affected by IBD in clinical practice.

New Insights into the Biological and Clinical Significance of Fecal Calprotectin in Inflammatory Bowel Disease

Nowadays, calprotectin, a cytoplasmatic protein, released by activated neutrophilic polymorphonuclear cells (PMN) and/or monocytes-macrophages (MØ), is considered a good indicator of inflammation in several diseases. Accordingly, fecal calprotectin represents a good predictor of clinical relapse in ulcerative colitis (UC) patients, whereas conflicting results have been reported in Crohn's disease (CD) patients. In our study, in 76 IBD patients (29 CD and 47 UC) fecal calprotectin has been evaluated by a commercial ELISA kit. Results demonstrate that levels of this protein in the stool are significantly more elevated in active CD and UC patients than in normal volunteers. In quiescent CD and UC a trend to higher levels of calprotectin than in the normal counterpart is, however, evident. These data suggest that a low-grade inflammation of the intestinal wall is always present in CD and UC patients, which may predict a clinical relapse risk. In the same group of patients calprotectin levels also were analyzed according to sex and age. A trend to higher values of calprotectin was present in male patients with active or quiescent CD than in their female counterparts. Only in UC patients in remission a trend to calprotectin increase was more marked in the male group than in the female counterpart. When CD and UC patients were divided up according to age, calprotectin positivity peaked between 30-39 years in active CD patients, while in quiescent CD maximum positivity was between 40 and 49 years. However, in both active and quiescent UC patients, calprotectin positivity increased with age. The more precocious detectability of fecal calprotectin in CD patients, as a marker of intestinal mucosa inflammation, may be related to the different histopathology of the two diseases (CD versus UC). However, reduced PMN and/or MØ trafficking from peripheral blood to intestinal mucosa with age by effects of chronic treatment should not be ignored in CD patients.

Detection and quantification of Prymnesium parvum (Haptophyceae) by real-time PCR

AIMS

The ichthyotoxic species Prymnesium parvum (Haptophyceae) is difficult to quantify in a microscopy-based monitoring programme, because the cells are very small, fragile and their morphology can be distorted by the use of fixatives. In the attempt to overcome these problems, a real-time PCR-based method for the rapid and sensitive identification and quantification of P. parvum was developed.

METHODS AND RESULTS

A quantitative real-time PCR assay was optimized with primers designed on the internal transcribed spacer 2 rDNA region of P. parvum. This PCR assay was specific, showing no amplification of DNA extracted from closely related species, and sensitive. Moreover, this method was able to detect and reliably quantify P. parvum cells in preserved environmental samples artificially spiked with known amounts of cultured cells.

CONCLUSIONS

Considering the specificity, sensitivity and applicability to preserved environmental samples, this method may be a useful tool for the monitoring of this toxic species.

SIGNIFICANCE AND IMPACT OF THE STUDY

The real-time PCR method described in this study may represent a progress towards the rapid detection and quantification of P. parvum cells in water-monitoring programmes, allowing the early application of strategies to control bloom events, such as the use of clay minerals.

Study on the oligosaccharides composition of the water-soluble fraction of marine mucilage by electrospray tandem mass spectrometry

The massive accumulation of organic matter, which periodically occurs in the northern Adriatic Sea, and in other locations worldwide, is presently thought to be the results of the aggregation of dissolved organic matter (DOM) into particulate organic matter (POM). This phenomenon is the result of human activities and propitious weather conditions. Although many aspects of the phenomenon are well understood, the trigger mechanisms leading to mucilage formation have not been clarified yet, probably as a consequence of inadequate analytical approaches. In this context, the recent advancements in LC-MS interfacing might contribute in clarifying the mechanism of mucilage formation. In the present paper, hydrophilic interaction liquid chromatography coupled with electrospray tandem mass spectrometry (HILC-ESI-MS/MS) is proposed as an innovative method for the investigation of underivatized oligosaccharides in mucilage samples. Recent findings suggest that the significant presence of these compounds in seawater can play an important role in the initial steps of the agglomeration processes forming gelatinous material. Our results reveal the presence of several maltodextrines in the water-soluble fraction of mucilage macroaggregates, collected in various locations of the northern Adriatic Sea. In our knowledge, the proposed method is the first application of LC-MS in the investigation of marine mucilage.

Capture probe conjugated to paramagnetic nanoparticles for purification of Alexandrium species (Dinophyceae) DNA from environmental samples

AIMS

To develop a rapid, cost-effective and selective Alexandrium DNA extraction procedure from environmental samples in order to provide good-quality template for the downstream PCR-based detection assay.

METHODS AND RESULTS

In this study, we tested a DNA extraction method based on silica-coated, superparamagnetic nanoparticles conjugated to a DNA-capture sequence (probe) complementary to a specific region of 5.8S rDNA of the genus Alexandrium. Cultured Alexandrium catenella cells were used as the harmful algal bloom species for the DNA extraction. Then, a PCR assay was performed with primers specific for the genus Alexandrium to assess the specificity and sensitivity of the nucleic acid extraction method. This method was applied to both cultured and field samples, reaching in both cases a detection limit of one A. catenella cell.

CONCLUSIONS

The results suggest that the use of probe-conjugated paramagnetic nanoparticles could be effective for the specific purification of microalgal DNA in cultured or environmental samples, ensuring sensitivity and specificity of the subsequent PCR assays.

SIGNIFICANCE AND IMPACT OF THE STUDY

The DNA extraction method optimized in this study represents a progress towards the rapid and efficient direct detection of Alexandrium cells in seawater monitoring. In fact, this method requires no other equipment than a magnet and a hybridization oven and, in principle, can be adapted to different toxic microalgal species and can be automated, allowing the processing of a high number of samples.

Thymidine phosphorylase profiles in nonmalignant and malignant pancreatic tissue. Potential therapeutic role of capecitabine on tumoral and endothelial cells and tumor-infiltrating macrophages

The drug capecitabine (CAP) is a thymidine Pi-deoxyribosyltransferase (TP) activated oral fluorpyrimidine that generates 5-fluorouracil (5-FU), preferentially, within tumors. Here, in 38 patients with pancreatic cancer we analyzed immunohistochemical TP expression in pancreatic cancer tissue (PCT) and adjacent nonmalignant pancreatic tissue (ANMPT). In addition, a correlation with the main clinical pathological features was made. Furthermore, TP-positive macrophages (MO) isolated from neoplastic tissue were determined. The mean of TP-positive epithelial cells and endothelial cells in terms of microvessel density was significantly higher in PCT than in ANMPT. Because pancreatic cancer is sensitive to 5-FU, TP-activated oral CAP in tumoral and endothelial cells and tumor infiltrating MO could increase the concentration of 5-FU at tumor site, thus resulting in an enhanced antitumor activity.

Identification of immunodominant hepatitis C virus (HCV)-specific cytotoxic T-cell epitopes by stimulation with endogenously synthesized HCV antigens

Hepatitis C virus (HCV)-specific CD8(+) cytotoxic T lymphocytes (CTL) are believed to play an important role in the pathogenesis of liver cell injury and viral clearance in HCV infection. Because HCV does not efficiently infect human cells in vitro and primary infected hepatocytes cannot be used as stimulator/target cells for CTL analysis, development of efficient systems to activate and expand CTL in vitro, reproducing antigen presentation to CTL occurring during natural infection, is mandatory to study CTL activity and to define the hierarchy of immunodominance of CTL epitopes. To achieve this goal, 5 different defective adenoviruses carrying structural and nonstructural HCV genes (core, core-E1-E2, E2, NS3-NS4A, NS3-NS5A) were used to induce the endogenous synthesis of HCV proteins in human adherent mononuclear cells in vitro and to allow their entry into the HLA class I cytosolic pathway of antigen processing. The cytolytic activity of peripheral blood lympho-mononuclear cells (PBMC) from HLA-A2(+) HCV-infected patients stimulated with recombinant adenovirus-infected cells was tested against target cells either pulsed with a panel of synthetic peptides containing the HLA-A2 binding motif or infected with recombinant vaccinia viruses carrying HCV genes. Our study defines a reproducible system to stimulate and expand HCV-specific CTL in vitro that mimics the conditions of antigen encounter in vivo. By this approach, we have identified several HLA-A2-restricted epitopes that should correspond to immunodominant HCV sequences recognized by CTL during natural infection. Therefore, these amino acid sequences represent ideal candidates for the design of therapeutic vaccines for chronic HCV infection.

Lamivudine treatment can overcome cytotoxic T-cell hyporesponsiveness in chronic hepatitis B: new perspectives for immune therapy

The hepatitis B virus (HBV) cytotoxic T lymphocyte (CTL) response in patients with chronic HBV infection is generally weak or totally undetectable. This inability to mount protective CTL responses is believed to be a crucial determinant of viral persistence, and its correction represents an important objective of immune therapies for chronic hepatitis B. However, amplification of CTL responses in vivo may be ineffective if HBV-specific CD8 cells are either absent or nonresponsive to exogenous stimulation. In this study, we asked whether antiviral treatments able to inhibit viral replication and to reduce viral and antigen load can successfully reconstitute CTL responses creating the appropriate conditions for their therapeutic stimulation. For this purpose, the HBV-specific CTL response before and during lamivudine therapy was studied longitudinally in 6 HLA-A2-positive patients with HBeAg+ chronic hepatitis B. Both HBV-specific cytotoxic T cell activity measured by chromium release assay on peptide stimulation in vitro and CD8+ T cell frequency measured ex vivo by HLA-A2/peptide tetramer staining were significantly augmented by lamivudine therapy. This enhancement followed the reconstitution of CD4 reactivity and the decline of viral load induced by therapy. Our study shows that lamivudine treatment in chronic hepatitis B can restore CTL reactivity, making CTL susceptible to exogenous stimulation. This effect may enhance the probability that T cell-based immune therapies delivered after lamivudine treatment can successfully reconstitute a protective CTL response able to cure chronic HBV infection.

Parasitic diatoms inside antarctic sponges

Antarctic sponges may host large populations of planktonic and benthic diatoms. After settling on the sponge, these diatoms enter its body through pinacocytes (1) and form, there, large mono- or pauci-specific assemblages. Yet the total amount of carbohydrates in the invaded sponge tissue is inversely correlated with that of chlorophyll-a. We suggest, therefore, that endobiont diatoms utilize the products of the metabolism of their host as an energy source. This is the first evidence indicating that an endobiotic autotrophic organism may parasitize its animal host. Moreover, this unusual symbiotic behavior could be a successful strategy that allows the diatom to survive in darkness.

Practice guidelines developed by specialty societies: the need for a critical appraisal

BACKGROUND

There is increasing concern about the quality, reliability, and independence of practice guidelines. Because no information is available on the methodological quality of the guidelines developed by specialty societies, we undertook a survey on those published in peer-reviewed journals.

METHODS

Practice guidelines produced by specialty societies and published in English between January, 1988, and July, 1998, where identified through MEDLINE. Their quality was assessed in terms of whether they reported: the type of professionals and stakeholders involved in the development process; the strategy to identify primary evidence; and an explicit grading of recommendations according to the quality of supporting evidence.

FINDINGS

Overall, 431 guidelines were eligible for the study. Most did not meet the criteria: 67% did not report any description of the type of stakeholders, 88% gave no information on searches for published studies, and 82% did not give any explicit grading of the strength of recommendations. There was improvement over time for searches (from 2% to 18%, p<0.001) and explicit grading of evidence (from 6% to 27%, p<0.001). All three criteria for quality were met in only 22 (5%) guidelines.

INTERPRETATION

Despite improvement over time, the quality of practice guidelines developed by specialty societies is unsatisfactory. Explicit methodological criteria for the production of guidelines shared among public agencies, scientific societies, and patients' associations need to be set up. Common standards of reporting, following the same principles that led to the CONSORT statement for randomised clinical trials, should be promoted.

Antiviral cell-mediated immune responses during hepatitis B and hepatitis C virus infections

Cell-mediated immune responses to hepatitis B (HBV) and hepatitis C virus (HCV) antigens are vigorous and multispecific in acute, self-limited infections. Moreover, the prevalent cytokine pattern of circulating virus-specific T cells from patients who recover spontaneously from acute hepatitis is Th1-like. Longitudinal analysis of the T cell response to HCV antigens from the early stages of HCV infection in patients who recover from hepatitis and those who do not indicates that weaker responses and a prevalent Th2 pattern of cytokine production is associated with viral persistence and chronic evolution of disease. Although similar sequential studies are missing in hepatitis B, the observation that HBV-specific T cell responses are very weak or totally undetectable in the peripheral blood of patients with long-lasting chronic hepatitis B suggests that strength and quality of virus-specific T cell responses at the early stages of infection may influence the final outcome of both hepatitis B and C. While T cell hyporesponsiveness seems to be an important determinant for HBV persistence once chronic hepatitis has developed, this mechanism appears to be less critical in chronic HCV infection, because the vigor and quality of HCV-specific T cell responses seem to improve as a function of the duration of infection. This is shown by the finding that HCV-specific CD4- and CD8-mediated responses are easily detectable in the peripheral blood of patients with long-lasting chronic hepatitis C and that production of Th1 cytokines predominates within their livers. HCV therefore seems to be able to persist even in the face of an active T cell response and to acquire the capacity to survive within a host environment apparently unfavorable to its persistence. The high variability of HCV may explain its efficiency in escaping immune surveillance.

Cytotoxic and hormonal treatment for metastatic breast cancer: a systematic review of published randomized trials involving 31,510 women

PURPOSE

A systematic review of randomized clinical trials (RCTs) was undertaken to assess the effectiveness of medical treatment for metastatic breast cancer.

METHODS

RCTs published between 1975 and 1997 have been classified according to 12 therapeutic comparisons: (1) polychemotherapy (PCHT) agents versus single agent; (2) PCHT regimens with anthracycline versus PCHT without anthracycline; (3) other PCHT versus cyclophosphamide, methotrexate, and fluorouracil (CMF); (4) chemotherapy (CHT) with epirubicin versus CHT with doxorubicin; (5) CHT versus same CHT delivered with less intensive schedules; (6) other endocrine therapy (OET) versus tamoxifen; (7) OET plus tamoxifen versus tamoxifen alone; (8) OET versus medroxyprogesterone; (9) OET versus aromatase inhibitors; (10) OET versus megestrol; (11) endocrine therapy (ET) versus same ET at lower doses; and (12) CHT plus ET versus CHT. Tumor response rates, mortality hazards ratio (HR) and frequency of severe side effects were the outcome measures.

RESULTS

A total of 189 eligible trials (31,510 patients) were identified. All provided response rates and 133 (70%) data or survival curves needed for calculation of the HR. In eight of 12 comparisons, statistically significant differences for response emerged (1, 2, 3, 5, 7, 8, 11, 12); all but no. 8 favored the first term of the comparison. Overall survival analysis showed better results of (a) PCHT versus single-agent CHT (HR=0.82; 95% confidence interval [CI], 0.75 to 0.90); (b) CHT with doxorubicin versus CHT with epirubicin (HR=1.13; 95% CI, 1.00 to 1.27); (c) CHT versus the same CHT delivered with less intensive schedules (HR=0.90; 95% CI, 0.83 to 0.97); (d) ET versus the same ET at lower doses (HR=0.86; 95% CI, 0.77 to 0.97). Quality of life was measured in only 2,995 of 31,510 patients (9.5%).

CONCLUSION

Despite some evidence of effectiveness of specific regimens, the relevance of these findings is limited by the modest survival benefit and the lack of evaluation of the quality-of-life impact of these treatments.

Lamivudine treatment can restore T cell responsiveness in chronic hepatitis B

High viral and/or antigen load may be an important cause of the T cell hyporesponsiveness to hepatitis B virus (HBV) antigens that is often observed in patients with chronic HBV infection. Reduction of viral and antigen load by lamivudine treatment represents an ideal model for investigating this hypothesis. HLA class II restricted T cell responses and serum levels of HBV-DNA, HBsAg, and HBeAg were studied before and during lamivudine treatment in 12 patients with hepatitis B e antigen positive chronic active hepatitis B to assess possible correlations between viral and/or antigen load and vigor of the T cell response. Cell proliferation to HBV nucleocapsid antigens and peptides and frequency of circulating HBV nucleocapsid-specific T cells were assessed to characterize CD4-mediated responses. A highly significant enhancement of the CD4-mediated response to HBV nucleocapsid antigens was already detectable in most patients 7-14 d after the start of lamivudine treatment. This effect was dramatic and persistent in 10 patients but undetectable in 2. It occurred concomitant with a rapid and marked reduction of viremia. Interestingly, lamivudine also enhanced the responses to mitogens and recall antigens, showing that its effect was not limited to HBV-specific T cells. In conclusion, an efficient antiviral T cell response can be restored by lamivudine treatment in patients with chronic hepatitis B concurrently with reduction of viremia, indicating the importance of viral load in the pathogenesis of T cell hyporesponsiveness in these patients. Since lamivudine treatment can overcome T cell hyporeactivity, combining lamivudine with treatments directed to stimulate the T cell response may represent an effective strategy to induce eradication of chronic HBV infection.

Molecular features of the hepatitis B virus nucleocapsid T-cell epitope 18-27: interaction with HLA and T-cell receptor

The strength of the cytotoxic T lymphocyte (CTL) response is believed to influence the final outcome of hepatitis B virus (HBV) infection. Among the different CTL epitopes so far identified, the sequence 18-27 of the HBV nucleocapsid antigen is widely recognized by CTL of HLA-A2-positive patients with acute self-limited HBV infection, and represents the main component of a peptide-based therapeutic vaccine aimed at stimulating the antiviral CTL response in patients with chronic hepatitis B. In the present study, we further analyzed the features of this important HBV region by the following: 1) defining the contribution of individual residues of the epitope to the interaction with the T-cell receptor (TCR) and with the HLA-A0201 molecule; 2) assessing the antigenicity of this viral region in the context of the different HLA-A2 subtypes; and 3) testing whether this sequence can stimulate not only HLA-class I but also HLA class II restricted T-cell responses. A clear hierarchy was observed in the ability of individual residues to act as TCR or HLA binding sites. Furthermore, the sequence HBc18-27 was able to be recognized by specific CTL when presented in the context of different HLA-A2 subtypes. Finally, this HBV region was also found to stimulate HLA class II restricted T-cell responses. These data further increase the potential coverage and efficacy of therapeutic vaccines based on the HBc18-27 sequence.

Predominant T-helper 1 cytokine profile of hepatitis B virus nucleocapsid-specific T cells in acute self-limited hepatitis B

The cytokine pattern secreted by T cells on viral antigen recognition is believed to exert a profound influence on both the type of disease caused by the infecting agent and the final outcome of the viral infection. To characterize the cytokine pattern associated with spontaneous resolution of acute hepatitis B, we analyzed interferon gamma (IFN-gamma), interleukin (IL)-4, and IL-5 production by a wide series of hepatitis B virus (HBV) nucleocapsid-specific T-cell lines (34 lines) and T-cell clones (71 clones) derived from the peripheral blood of 13 patients during the acute or recovery phase of hepatitis B (2 and 7 of them were studied only in the recovery or the acute phase, respectively, and 4 during both). Most T-cell lines (67%) and clones (77%) isolated during the acute phase of infection expressed a T-helper (Th) 1 cytokine profile dominated by the production of IFN-gamma. A larger proportion (74%) of T-cell lines produced several years after resolution of hepatitis was able to secrete not only IFN-gamma, but also IL-4 and IL-5 (Th0-like cells). Results indicate that the antigen-specific fraction of peripheral blood T cells in acute self-limited hepatitis B selectively secrete Th1-type eytokines, suggesting that Th1-mediated effects may contribute not only to liver cell injury, but probably also to recovery from disease and successful control of infection.

Different cytokine profiles of intraphepatic T cells in chronic hepatitis B and hepatitis C virus infections

BACKGROUND & AIMS

The cytokine pattern secreted by T cells at the site of viral replication may influence the final outcome of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. The aim of this study was to assess whether a cytokine imbalance oriented toward T helper (Th) 1 or Th2-type responses may play a role in chronic hepatitis B or C.

METHODS

Production of interferon (IFN)-gamma, interleukin (IL)-4, and IL-5 by wide series of T-cell clones derived from the liver of 6 patients with chronic hepatitis B (291 clones) and 9 patients with chronic hepatitis C (260 clones) was studied. T-cell clones were generated by limiting dilution from freshly isolated mononuclear cells derived from liver tissue to give a reliable representation of the intrahepatic inflammatory infiltrates.

RESULTS

The majority of liver-infiltrating T cells in chronic hepatitis C were Th1 cells able to secrete IFN-gamma but unable to secrete IL-4 or IL-5, whereas in hepatitis B, most CD4+ and CD8+ liver T cells were ThO-like cells able to produce not only IFN-gamma but also IL-4 and IL-5.

CONCLUSIONS

The different cytokine profiles of T cells within the liver in chronic HBV and HCV infections illustrate a different behavior of the local immune response in these two infections that may have pathogenetic implications.

Physicians' view of practice guidelines. A survey of Italian physicians

After more than 10 years of development, two different views of practice guidelines are emerging: either as an educational tool for the medical profession, or as a forum where health care issues can be debated by physicians and non-medical groups. Physicians use practice guidelines in the former model to set their own standards of good quality care, while the latter approach needs contributions from other components in order to decide what should be provided by our health care systems. In a survey of Italian physicians' opinions and attitudes toward practice guidelines, responders supported the "narrowest" model. More than 80% stated that improvement of quality of care and reduction of variation in clinical and practice styles should be the aim of practice guidelines, without representatives from outside the medical profession being involved (61%, 79% and 86% disagreed with a possible involvement, respectively, of patients, health care administrators and representatives of the public at large). Overall, 38% of physicians had a positive attitude toward guidelines viewed as a quality assurance tool for the medical profession. Overall, physicians seem to ignore that the need to rationalize health care calls for input from other professions and members of society. Indeed, most of the issues facing medicine today are mainly a matter of how much value our societies attach to the benefit expected from the available health services. The answers as to what should be done in health care probably cannot be left to the medical profession alone.

Long-lasting memory T cell responses following self-limited acute hepatitis B

The molecular and cellular basis of long-term T cell memory against viral antigens is still largely undefined. To characterize anti-viral protection by memory T cells against non-cytopathic viruses able to cause acute self-limited and chronic infections, such as the hepatitis B virus (HBV), we studied HLA class II restricted responses against HBV structural antigens in 17 patients with acute hepatitis B, during the acute stage of infection and 2.2 to 13 yr after clinical resolution of disease. Results indicate that: (a) significant T cell proliferative responses to HBV nucleocapsid antigens were detectable in all patients during the acute phase of infection and in 14/17 also 2-13 yr after clinical resolution of disease; b) long-lasting T cell responses were sustained by CD45RO+T cells, predominantly expressing the phenotype of recently activated cells; c) limiting dilution analysis showed that in some patients the frequency of HBV-specific T cells was comparable to that observed in the acute stage of infection and, usually, higher than in patients with chronic HBV infection; d) the same amino acid sequences were recognized by T cells in the acute and recovery phases of infection; and e) HBV-DNA was detectable by nested-PCR in approximately half of the subjects. to conclusion, our results show that vigorous anti-viral T cell responses are detectable in vitro several years after clinical recovery from acute hepatitis B. Detection of minute amounts of virus in some recovered subjects suggests that long-term maintenance of an active anti-viral T cell response could be important not only for protection against reinfection but also for keeping the persisting virus under tight control.

Short stay facilities: the future of efficient paediatric emergency services

Many children admitted to hospital can stay for 24 hours or less. Short stay facilities offer such children rapid stabilisation and early discharge with considerable financial saving. A 12 month study was completed in which data were collected from the children's emergency annex (CEA) at Westmead Hospital in Sydney's western suburbs. This university based teaching hospital provides care for a large paediatric population as well as three other district hospitals with limited children's bed capacity. From April 1994 to April 1995, 1300 children were admitted and entered into a database of general and hospital-specific information. Critical incident monitoring was undertaken and follow up with review within 24-72 hours for all children. The CEA increased hospital efficiency significantly by reducing bed days, with a saving of over $500,000 to the department. The average length of stay was 17.5 hours, and 58% of users were children of 2 years and under. Only 3% remained beyond 24 hours, and another 4% were admitted to inpatient beds for continued management of the primarily diagnosed condition. No critical incident was reported during this 12 month period. Short stay facilities are efficient and cost-effective for children with acute illness who can be rapidly stabilised with early discharge without critical incident. Children 12 months and under are particularly suited to this type of facility. Short stay facilities should be used to augment efficiency within children's emergency services which have high turnover and limited bed capacity.

Completeness of reporting of trials published in languages other than English: implications for conduct and reporting of systematic reviews

BACKGROUND

Lately, the number of systematic reviews published has increased substantially. Many systematic reviews exclude trials published in languages other than English. However, there is little empirical evidence to support this action. We looked for differences in the completeness of reporting between trials published in other languages and those published in English, to see whether the exclusion of trials published in other languages is justified.

METHODS

We compared completeness of reporting, design characteristics, and analytical approaches of 133 randomised controlled trials (RCTs) published in English between 1989 and 1994 and 96 published in French, German, Italian, or Spanish during the same time. RCTs were identified by hand searching of journals (seven in English and six in the other languages).

FINDINGS

We found no significant differences between trials published in English and other-language trials for any single item in the completeness of reporting scale (randomisation, double-blinding, withdrawals), or for the overall score (percentage of maximum possible score 51.0% for trials in English, 46.2% for trials in other languages; 95% CI for difference -1.1 to 10.5). Other-language trials were more likely than English-language trials to have adult participants, to use two or more interventions, and to compare two or more active treatments without an untreated control group. Trials in other languages were less likely to report a clearly prespecified primary outcome or any rationale for sample size estimation.

INTERPRETATION

These results provide evidence for inclusion of all trial reports, irrespective of the language in which they are published, in systematic reviews. Their inclusion is likely to increase precision and may reduce systematic errors. We hope that our findings will prove useful to those developing guidelines and policies for the conduct of reporting of systematic reviews.

Cytotoxic T lymphocyte response to a wild type hepatitis B virus epitope in patients chronically infected by variant viruses carrying substitutions within the epitope

Mutations that abrogate recognition of a viral epitope by class I-restricted cytotoxic T lymphocyte (CTL) can lead to viral escape if the CTL response against that epitope is crucial for viral clearance. The likelihood of this type of event is low when the CTL response is simultaneously directed against multiple viral epitopes, as has been recently reported for patients with acute self-limited hepatitis B virus (HBV) infection. The CTL response to HBV is usually quite weak, however, during chronic HBV infection, and it is generally acknowledged that this is a major determinant of viral persistence in this disease. If such individuals were to produce a mono- or oligospecific CTL response, however, negative selection of the corresponding mutant viruses might occur. We have recently studied two HLA-A2-positive patients with chronic hepatitis B who, atypically, developed a strong HLA-A2-restricted CTL response against an epitope (FLPSDFFPSV) that contains an HLA-A2-binding motif located between residues 18-27 of the viral nucleocapsid protein, hepatitis B core antigen (HBcAg). These patients failed, however, to respond to any of other HLA-A2-restricted HBV-derived peptides that are generally immunogenic in acutely infected patients who successfully clear the virus. Interestingly, DNA sequence analysis of HBV isolates from these two patients demonstrated alternative residues at position 27 (V --> A and V --> I) and position 21 (S --> N, S --> A, and S --> V) that reduced the HLA and T cell receptor-binding capacities of the variant sequences, respectively. Synthetic peptides containing these alternative sequences were poorly immunogenic compared to the prototype HBc18-27 sequence, and they could not be recognized by CTL clones specific for the prototype peptide. While we do not know if the two patients were originally infected by these variant viruses or if the variants emerged subsequent to infection because of immune selection, the results are most consistent with the latter hypothesis. If this is correct, the data suggest that negative selection of mutant viral genomes might contribute to viral persistence in a subset of patients with chronic HBV infection who express a narrow repertoire of anti-HBV CTL responses.

Variation in use of breast surgery and characteristics of hospitals' surgical staff

OBJECTIVE

To assess whether and how the characteristics of hospitals' surgical staff can predict utilization of breast conserving surgery. We anticipated that the use of the procedure was more frequent in hospitals with a greater proportion of younger and female surgeons on their staff.

SETTING

Sixty-two hospitals with different level of organization for the care of cancer patient from eight Italian regions were included.

DESIGN

We collected information on the personal characteristics (age and sex) of all surgeons on the staff of the participating centers. A concurrent pattern of care study was undertaken, in order to assess the utilization of breast conserving procedures.

RESULTS

The use of conservative surgery was 16%, 20%, 31%, in centers with 0%, < 20% and 20-50% female surgeons respectively (p = 0.003), while no associations emerged between the mean age of the surgical staff and the use of conservative surgery. This relationship also held true after adjusting for other patients' characteristics, such as stage of disease, age and presence of comorbidity. However, overall the use of patient-related and staff-related characteristics to predict the number of breast conserving surgeries performed in each area was able to explain only 16% of the observed variability in the use of breast conserving surgery.

CONCLUSIONS

Even though in this study a large proportion of the observed variation in the use of breast conserving surgery was still left unexplained, this finding suggests that assessing the relationship between doctors' characteristics and the use of scientific evidence is an important topic for health service research and can be of some help in exploring variations in clinical practice styles.

Natural variants of cytotoxic epitopes are T-cell receptor antagonists for antiviral cytotoxic T cells

It has been suggested that mutations within immunodominant cytotoxic T-lymphocyte (CTL) epitopes may be exploited by viruses to evade protective immune responses critical for clearance. Viral escape could originate from passive mechanisms, such as mutations within crucial CTL epitopes, either affecting major histocompatibility complex binding or T-cell antigen receptor (TCR) recognition. Additionally, it has recently been shown that substitutions of TCR contact sites can yield analogue peptides that can still interact with the T-cell receptor but be unable to deliver a full stimulatory signal, thus inducing anergy or acting as an antagonist for the TCR. We report here that hepatitis B virus isolates derived from two chronically infected patients display variant epitopes that act as natural TCR antagonists with the capacity to inhibit the CTL response to the wild-type epitope. During natural infection, TCR antagonist mutations of CTL epitopes could contribute to the development of viral persistence, especially if the antiviral CTL response is monospecific or the epitope is strongly immunodominant.

[The effect of ursodeoxycholic acid in patients with liver cirrhosis and chronic hypertransaminasemia]

The aim of the study was to evaluate the effect of ursodeoxycholic acid (UDCA) oral administration on alanine aminotransferases (ALT) levels in cirrhotic patients with chronic hypertransaminasemia. Ninety consecutive patients with histologically proven liver cirrhosis and ALT levels higher than twice the upper limit of normal for at least six months, were admitted to the study. All the patients were treated with UDCA 10 mg/kg/day for one year. At the end of this period they were randomized to placebo or to continue UDCA therapy for three further months. ALT levels were evaluated before the beginning of UDCA therapy, at twelve and fifteen months by standard methods. After 12 months of UDCA, ALT decreased significantly (-39 UI, 95% confidence intervals -27 to -52 UI). At the 15 th month ALT did not vary with respect to its values at the 12th month in 36 patients randomized to continue UDCA, while it increased significantly in patients taking the placebo (+11 UI 95% confidence intervals +2 to +19). The results of this study suggest that UDCA is effective in controlling the biochemical activity of the liver disease in cirrhotic patients.

T-cell response to structural and nonstructural hepatitis C virus antigens in persistent and self-limited hepatitis C virus infections

Twenty-nine patients with chronic hepatitis C and 15 asymptomatic hepatitis C virus antibody-positive subjects who clinically recovered from hepatitis C virus infection were studied for their peripheral blood lymphomononuclear cell proliferative response to hepatitis C virus structural and nonstructural antigens (core, envelope, nonstructural 4 and nonstructural 5) expressed in yeast as superoxide dismutase fusion proteins, in an initial attempt to define some of the features of the virus-specific immune response. Hepatitis C virus core was the most immunogenic antigen for human leukocyte antigen class II-restricted T cells in both groups of patients studied, and the proliferative response to it was the most vigorous and the most frequently expressed in comparison with the other antigens tested. The specificity of the results was supported by the lack of response to hepatitis C virus antigens by healthy uninfected controls and confirmed by recognition of recombinant core proteins of different origin (yeast and baculovirus) by polyclonal T-cell lines produced by T-cell stimulation with yeast-derived core. Each of the antigens tested was able to induce significant although variable levels of proliferative response, indicating that all can be immunogenic at the T-cell level. Significant proliferative responses to core, nonstructural 4 and nonstructural 5 antigens were more frequently detected in subjects who were able to eradicate infection than in patients with chronic hepatitis C, although the difference was statistically not significant. No difference was observed between the two groups of patients with respect to the response to the putative envelope antigens.

Inappropriate Halsted mastectomy and patient volume in Italian hospitals

To study whether Halsted mastectomy was used only when properly indicated, a prospective survey was undertaken on the process of care of 985 breast cancer patients seen consecutively at 62 general hospitals in Northern and Central Italy. Overall, 79% of Halsted mastectomies were performed inappropriately. The procedure was less likely to be performed on more educated patients and, other factors considered, on those seen at hospitals with larger volume. We conclude that the measurement of utilization of a surgical procedure for which only a few appropriate indications exist may help identify important relationships between hospital characteristics and quality of surgical care.

[The adjuvant treatment of operable breast carcinoma. The current status and outlook]

Breast cancer represents one of the most frequent neoplasm: every year, in Italy, 25,000 new cases are diagnosed with more than 9,000 deaths. In Italy--and also in other countries--has been shown a broad variability in the use of diagnostic or therapeutic procedures caused by different hospitals' characteristics, patients' conditions and physicians' opinions. Among the different therapeutic options, post-surgical therapy, that extends the disease-free interval and survival, fills an important position in the cure of breast cancer in relation to the overview published on Lancet the 4th and the 11th January 1992. According to this overview, patients who had surgery for breast cancer benefitted by an adjuvant therapy--hormonal or cytotoxic--with a reduction of mortality between 15 and 20%. That means, in Italy, a reduction of one thousand deaths per year for this neoplasm. Particularly the effectiveness of hormonal treatment in postmenopausal patients (not only in the oestrogen receptor (ER) positive but in the ER poor too), of ovarian ablation and chemotherapy in premenopausal patients was confirmed. In node negative patients the present overview recommends the adjuvant treatment for the risk reduction in recurrence and mortality. Nevertheless important research implications persist about treatment and a better definition of high risk patients; therefore more patient should be included in the randomized clinical trial.

Definition of a minimal optimal cytotoxic T-cell epitope within the hepatitis B virus nucleocapsid protein

Residues 11 to 27 of the hepatitis B virus nucleocapsid antigen contain a cytotoxic T-cell epitope that is recognized by cytotoxic T cells from virtually all HLA-A2-positive patients with acute hepatitis B virus infection. Using panels of truncated and overlapping peptides, we now show that the optimal amino acid sequence recognized by cytotoxic T cells is a 10-mer (residues 18 to 27) containing the predicted peptide-binding motif for HLA-A2 and that this peptide can stimulate cytotoxic T cells able to recognize endogenously synthesized hepatitis B core antigen. Since patients with chronic hepatitis B virus infection fail to mount an efficient cytotoxic T-cell response to it, this epitope might serve as the starting point for the design of synthetic peptide-based immunotherapeutic strategies to terminate persistent viral infection.

The influence of patient characteristics on the appropriateness of surgical treatment for breast cancer patients. Progetto Oncologia Femminile

BACKGROUND

Within the framework of a multi-annual educational intervention sponsored by the Ministry of Health and regional health authorities, patterns of the care delivered to breast cancer patients in Italian general hospitals were monitored in order to identify areas of practice whose quality was in need of improvement.

DESIGN

Information on the diagnostic and therapeutic procedures in 63 general hospitals in eight Italian regions performed in 1724 consecutive breast cancer patients were retrospectively gathered from medical records. Quality of care was assessed by a diagnostic and therapeutic score based on the observed degree of compliance with previously established courses of action.

RESULTS

The median value of the overall diagnostic and staging score was 60%. About one-third of surgical operations (38%) were inappropriate: one-fourth (24%) of patients with stage I-II disease had unnecessarily radical surgery (i.e., Halsted mastectomy), and limited surgery in patients with small tumors (i.e., < or = 2 cm) was under utilized. Chronological age influenced physicians' behaviour: elderly patients were more likely to have a less intensive diagnostic work-up and less appropriate surgical treatment (with more frequent performance of an unnecessary radical operation and a less frequent utilization of limited surgery), independently of their overall health status. The presence of one or more co-existent diseases was associated with a failure to undergo axillary clearance and with a lower utilization of conservative surgery independently of age.

CONCLUSION

In accord with others, this study confirms the existence of a clinically important effect of patient age on diagnostic and therapeutic behaviour and the use of unnecessarily radical surgery procedures. The paper discusses the implications of these findings for the next stage of the educational project, in which practice guidelines will be developed and implemented to improve the quality of care for breast cancer patients.

Cell mediated immune response to hepatitis B virus nucleocapsid antigen

A coordinated and efficient development of humoral and cell-mediated immune responses is believed to be required for complete eradication of viral infections. During the course of hepatitis B virus (HBV) infection, the HLA class II and class I-restricted T cell responses to HBV nucleocapsid antigens are vigorous in patients with acute infection who succeed in clearing the virus but weak or totally absent in patients with chronic persistence of the virus. These findings suggest a role for these responses in the pathogenesis of hepatitis B and in HBV clearance. Molecular analysis of T cell recognition of the HBV nucleoprotein defines the presence of immunodominant core epitopes recognized by helper and cytotoxic T cells that may represent the starting point for the design of alternative strategies for prevention and treatment of HBV infection.

Fine specificity of the human T-cell response to the hepatitis B virus preS1 antigen

The T-cell response to hepatitis B virus envelope antigens was studied in 11 hepatitis B vaccine recipients; 7 were selected to analyze the fine specificity of the T-cell response to the preS1 antigen. Four distinct T-cell epitopes were identified by peripheral blood lymphomononuclear cell stimulation with a panel of short synthetic peptides covering the preS1 sequence. The immunodominance of the preS1 epitopes included within peptides 21-30 and 29-48 was shown by their capacity to restimulate an HLA class II restricted proliferative response of T cells primed with the whole preS1 antigen. Conversely, peptide-specific T cells selected by peripheral blood lymphomononuclear cell stimulation with peptides 21-30 and 29-48 were able to recognize the native preS1 molecule, confirming that these epitopes are actually generated by the intracellular processing of preS1. Finally, amino acid residues essential for T-cell activation by peptide 21-30 were identified using 10 analogues of the stimulatory peptide containing single alanine substitutions. These results may be relevant to the design of efficient synthetic vaccines against hepatitis B virus infection.

[The immunopathogenesis of hepatitis B]

Knowledge of hepatitis B immunopathogenesis has greatly improved in the last few years thanks to the development of new methods of lymphocyte culture and the introduction of molecular techniques in the study of the cell-mediated antiviral immune responses. Some of the immune mechanisms likely responsible for liver cell injury and viral clearance during hepatitis B have recently been characterized. By using synthetic peptides and high efficiency recombinant expression vectors. HLA class I restricted cytotoxic T cells specifically able to recognize the nucleocapsid antigen of the hepatitis B virus (HBV) have been isolated from the blood of patients with acute self-limited hepatitis B. The observation that this cytotoxic response is lacking or very weak in chronic patients who do not succeed in clearing the virus suggests a major role for cytotoxic T cells in terminating virus infection. Similar behaviour is shown by HLA class II restricted CD4+ T cells which express much stronger levels of response to HBV nucleocapsid antigens in acute than in chronic HBV infection. Whether these defective responses in chronic patients are due to an actual lesion of the host's immune system or to viral mutations affecting immune surveillance and thereby allowing virus escape, still remain open issues. A definitive answer to these questions will, we hope, provide the appropriate tools to devise effective immune therapies against chronic HBV infection.

Autopresentation of hepatitis B virus envelope antigens by T cells

Processing and presentation by T cells appear to be limited to antigens that can directly interact with the T-cell surface, thereby overcoming the T-cell inefficiency in antigen capture and internalization. Our study provides evidence that the hepatitis B virus (HBV) envelope proteins can also be efficiently processed and presented by CD4+ and CD8+ T cells to other T cells in a human leukocyte antigen class II-restricted fashion. This phenomenon suggests a receptor-mediated interaction between T cells and the HBV envelope and defines a system that can, we hope, be exploited for the identification of the receptor binding site within the HBV envelope and for the characterization of the putative cellular HBV receptor.