Locoregional radiotherapy improves survival outcomes in de novo metastatic nasopharyngeal carcinoma treated with chemoimmunotherapy.

BACKGROUND: We aimed to investigate the efficacy of locoregional radiotherapy (LRRT) in patients with de novo metastatic nasopharyngeal carcinoma (dmNPC) receiving chemotherapy combined with anti-programmed cell death receptor-1 monoclonal antibodies (anti-PD-1 mAbs) as first-line treatment and identify optimal candidates for LRRT. MATERIALS AND METHODS: We enrolled patients with dmNPC receiving platinum-based palliative chemotherapy and anti-PD-1 mAbs followed or not followed by LRRT from four centers. The endpoints were progression-free survival (PFS), objective response rate (ORR), and overall survival (OS). We used the inverse probability of treatment weighting (IPTW) to balance the baseline characteristics of the LRRT and non-LRRT groups to minimize selection bias before comparative analyses. Multivariate analyses were carried out using the Cox proportional hazards model. RESULTS: We included 163 patients with dmNPC (median follow-up: 22 months). The median PFS was 20 months, and the ORR was 92.0%; the median OS was not achieved. After IPTW adjustments, patients who received LRRT had a significant survival benefit over those not receiving LRRT (median PFS: 28 versus 15 months, P < 0.001). The Epstein-Barr virus DNA (EBV DNA) level after four to six cycles of anti-PD-1 mAbs [weighted hazard ratio (HR): 2.19, 95% confidence interval (CI) 1.22-3.92, P = 0.008] and LRRT (weighted HR: 0.58, 95% CI 0.34-0.99, P = 0.04) were independent prognostic factors. Patients with undetectable EBV DNA levels after four to six cycles of anti-PD-1 mAbs (early EBV DNA clearance) benefitted from LRRT (HR: 0.41, 95% CI 0.22-0.79, P = 0.008), whereas those with detectable levels did not (HR: 1.30, 95% CI 0.59-2.87, P = 0.51). CONCLUSIONS: Palliative chemotherapy combined with anti-PD-1 mAbs followed by LRRT was associated with improved PFS in patients with dmNPC, especially for patients with early EBV DNA clearance.

[Analysis of the whole genome traceability and transmission path simulation experiment of the local cluster COVID-19 epidemic].

Objective: To trace and characterize the whole genome of SARS-CoV-2 of confirmed cases in the outbreak of COVID-19 on July 31, 2021 in Henan Province. Method: Genome-wide sequencing and comparative analysis were performed on positive nucleic acid samples of SARS-CoV-2 from 167 local cases related to the epidemic on July 31, 2021, to analyze the consistency and evolution of the whole genome sequence of virus. Results: Through high-throughput sequencing, a total of 106 cases of SARS-CoV-2 whole genome sequences were obtained. The results of genome analysis showed that the whole genome sequences of 106 cases belonged to the VOC/Delta variant strain (B.1.617.2 clade), and the whole genome sequences of 106 cases were shared with the genomes of 3 imported cases from Myanmar admitted to a hospital in Zhengzhou. On the basis of 45 nucleotide sites, 1-5 nucleotide variation sites were added, and the genome sequence was highly homologous. Conclusion: Combined with the comprehensive analysis of viral genomics, transmission path simulation experiments and epidemiology, it is determined that the local new epidemic in Henan Province is caused by imported cases in the nosocomial area, and the spillover has caused localized infection in the community. At the same time, it spills over to some provincial cities and results in localized clustered epidemics.

[Associations between different levels of blood pressure and risk of prediabetes].

Objective: To explore sex and rural-urban differences in the associations of different blood pressure levels with the risk of prediabetes. Methods: We used a multi-stage stratified cluster random sampling method to investigate 21 637 residents aged ≥18 years from 10 survey areas in Hubei province in 2020. The data on questionnaire, physical measurements, and laboratory indicators of the participants were collected. The associations of different blood pressure levels with risk of prediabetes by sex and regions were analyzed using multivariate logistic regressions after complex weighting. Results: A total of 16 111 subjects were included. The prevalence (95%CI) of prediabetes, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and IFG complicated with IGT were 25.1% (14.4%-35.9%), 12.7% (3.2%-22.1%), 8.1% (6.3%-9.8%), and 4.4% (2.3%-6.5%), respectively. After multivariate adjustment, the risk of prediabetes, IFG, IGT, and IFG complicated with IGT increased with the increment of blood pressure (both P for trend <0.05). The positive dose-response relationships between blood pressure levels and risk of prediabetes were also significant among male, urban, and rural residents (both P for trend <0.05), and the interactions between sex and blood pressure showed significant associations for risk of prediabetes and IGT (both P for interaction <0.05). Conclusions: Higher blood pressure levels were associated with an increased risk of prediabetes. The association with prediabetes was stronger in males, but no significant difference was found between urban and rural residents. More distinctive and effective prevention and control strategies should be developed for different populations.

[Study of portal venous pressure gradient to predict high-hepatic encephalopathy-risk population post TIPS].

Transjugular intrahepatic portosystemic shunt (TIPS) can effectively reduce the portal venous pressure and relieve the clinical complications related to portal hypertension. However, hepatic encephalopathy (HE) is still the main complication post TIPS. Studies have shown that patients over 65 years old with liver function reserve in Child-Pugh grade C are the high-HE-risk group post TIPS, and early TIPS treatment can benefit the survival of these high-risk patients. In this study, TIPS was used to treat 60 cases aged > 65 years old and liver function reserve in Child-Pugh grade C (decompensated liver cirrhosis) with esophagogastric variceal bleeding. The clinical results of 1-year was observed and the porto systemic gradient (PSG) was evaluated. The relationship between the incidence of HE and the PSG of patients with and without HE were compared to evaluate the effect of PSG on the incidence of HE.

Gout in China, 1990-2017: the Global Burden of Disease Study 2017.

OBJECTIVE: The aim of the study was to estimate the gout burden and risk factors in China from 1990 to 2017. STUDY DESIGN: The Global Burden of Disease (GBD) Study uses various analytical tools and a diverse set of data sources to generate comparable estimates of deaths and mortality rates broken down by age, sex, cause, year, and geography. METHODS: We used the results from the GBD Study 2017 to compare disability-adjusted life years (DALYs), prevalence, incidence, and risk factors of gout in China. The median of the percentage change and 95% uncertainty intervals were determined for the period between 1990 and 2017. RESULTS: The age-standardized DALY rate, prevalence, and incidence increased 6.92%, 6.88%, and 6.16%, respectively, in China from 1990 to 2017. Although the rates of gout both globally and in China were increasing, the range of change for males in China was larger than that of the global level. All risk factors combined accounted for 30.04% of gout DALYs in 2017. The leading risk factors for gout DALYs were high body mass index and impaired kidney function, and the proportion of high body mass index increased significantly from 10.67% to 24.31%, whereas the proportion of impaired kidney function remained basically unchanged. CONCLUSIONS: The age-standardized DALY rate, prevalence, and incidence in China have increased progressively since 1990. Increasing attention on body weight management should be prioritized for controlling the rising prevalence of gout in the young and middle-aged population.

[Review on the etiology and complications of hand, foot and mouth disease, using data from the national sentinel surveillance program, in China, 2015-2016].

Objective: To understand the characteristics relating to the etiology and complications of hand, foot and mouth disease (HFMD) based on data from the pilot National Sentinel Surveillance (NSS) program so as to explore the feasibility, advantages and disadvantages of the NSS. Methods: Data were extracted from the NSS system, conducted in 11 provinces of China from November 2015 to October 2016. Characteristics regarding the etiology, complications of HFMD and factors related to the positive rates of HFMD specimens were analyzed under the logistic regression method by SPSS 20.0 software. Results: A total of 4 783 specimens were collected, including 3 390 from mild, 1 390 from severe and 3 from death cases. The overall positive rate was 81.43% (3 895/4 783). Other enteroviruses (non EV71/Cox A16 enteroviruses) appeared the major serotype (52.68%, 1 482/2 813) for mild infection of the disease while EV71 was for the severe cases (65.31%, 706/1 081). The serotype spectrum revealed by the pilot NSS was almost identical with the existing surveillance system. Other enteroviruses tended to infect younger children (χ(2)=130.17, P<0.001) than EV71 and Cox A16, in China. The multivariate logistic regression results showed that higher positive rate was associated with specimens which were collected from males, at children' hospitals, in peak seasons, timely and in stools. The positive rates presented downwarding trends with the extension of the onset-sampling interval (χ(2)=14.47, P<0.001 in stool specimen; χ(2)=31.99, P<0.001 in throat swab; χ(2)=24.26, P<0.001 in anal swab). Aseptic meningitis, non-brainstem encephalitis and brainstem encephalitis appeared the top three complications of both EV71-associated and other enteroviruses-associated severe HFMD cases. Conclusions: Factors as gender, season/place/timeliness of specimen collection, and types of hospital all appeared independently influenced the positive rates. NSS seemed feasible to be used as an alternative or supplement tool to the existing surveillance program in China.

The clinical observation of verapamil in combination with interventional chemotherapy in advanced gastric cancer.

OBJECTIVE: We analyzed the clinical observations of target arterial infusion of verapamil combined with chemotherapy as therapy for advanced gastric cancer. PATIENTS AND METHODS: From March 2012 to December 2015, a total of 63 patients with advanced gastric cancer were admitted to our department. The target artery in the control group was perfused with chemotherapy drugs only, and the target artery in the therapy group was injected with verapamil combined with chemotherapy drugs. RESULTS: The therapeutic effect of the therapy group was significantly better than that of the control group in the primary foci of gastric cancer. Liver metastatic lesions: 11 patients in the control group had liver metastases and 25 patients in the therapy group had liver metastases. The effective rate (CR+PR) of the therapy group was significantly better than the control group. Clinical benefit evaluation: in the therapy group of 43 cases, 40 cases presented positive clinical benefit and 38 cases positive clinical weight in KFS scoring system; the clinical benefit of the therapy group was significantly better than control group. Survival analysis: the disease progression-free rate and survival rate of the therapy group were 12 months and 24 months, which were higher than those in the control group. The median PFS and median OS were also significantly longer than those in the control group (p<0.01). In the therapy group, adverse effects of chemotherapy in 43 patients were relieved in a short time. CONCLUSIONS: Target arterial infusion of verapamil combined with chemotherapy drugs for advanced gastric cancer can significantly improve the efficacy of chemotherapy drugs and prolong the survival of patients.

Chronic obstructive pulmonary disease deaths, disability-adjusted life years, and risk factors in Hubei province of mid-China, 1990-2015: the Global Burden of Disease Study 2015.

OBJECTIVES: The trends of chronic obstructive pulmonary disease (COPD) mortality and prevalence from 1990 to 2015 in Hubei province of mid-China remain unknown. We used findings from the Global Burden of Disease (GBD) 2015 study to estimate the COPD burden and attributable to risk factors in Hubei province of China from 1990 to 2015. STUDY DESIGN: The GBD study uses various analytical tools and a diverse set of data sources to generate comparable estimates of deaths and mortality rates broken down by age, sex, cause, year, and geography. METHODS: Data were extracted from the GBD 2015 study. Statistical models were used to produce comprehensive results of COPD deaths, prevalence, disability-adjusted life years (DALYs), years of life lost, years lived with a disability, and attributable to risk factors in Hubei. The median of the percent change and 95% uncertainty intervals were determined for the period between 1990 and 2015. RESULTS: In 2015, there were 37,144 deaths from COPD in Hubei, accounting for 10.05% of the total deaths in Hubei. The age-standardized COPD death rate was reduced by 60.28% from 188.67 per 100,000 (in 1990) to 74.94 per 100,000 (in 2015). The age-standardized prevalence decreased from 4.30% (1990) to 2.85% (2015). By 2015, the leading risk factors for all ages COPD DALYs were smoking and ambient particulate matter pollution, accounting for 44.69% and 32.91%, respectively. The proportion of ambient ozone pollution was increasing steadily each year since 1990. CONCLUSION: Hubei has made substantial progress in reducing the mortality due to COPD since 1990, but the absolute number of COPD cases is increasing steadily, given the population growth and aging. The increasing contribution from smoking, ambient particulate matter pollution, and ambient ozone pollution should require growing attention.

[Severe cases with hand, foot and mouth disease: data based on national pilot hand, foot and mouth disease surveillance system].

Objective: To investigate the clinical severity, etiological classification and risk factors of severe cases with hand, foot and mouth disease (HFMD). Methods: A total of 1 489 records on severe and fatal HFMD cases reported to the national pilot surveillance system of HFMD were used to analyze the demographic, medical treatment, etiological classification of the cases. Treatment outcome related risk factors were also studied with multi-variable stepwise logistic regression method. Results: Seven out of the 1 489 severe HFMD cases died of this disease. A total of 960 (72.9%) were under three years old and 62.9% were male and most of the cases (937, 62.9%) resided in rural areas. Among all the cases, 494 (33.2%) went to seek the first medical assistance at the institutions of village or township level. Durations between disease onset and first medical attendance, being diagnosed as the disease or diagnosed as severe cases were 0(0-1) d, 1 (0-2) d and 2 (1-4) d, respectively. In total, 773 (51.9%) of the severe HFMD cases were diagnosed as with aseptic meningitis, 260 (17.5%) with brainstem encephalitis, 377 (25.3%) with non-brainstem encephalitis, 6 (0.4%) with encephalomyelitis, 1 (0.1%) with acute flaccid paralysis, 4 (0.3%) with pulmonary hemorrhage/pulmonary edema and 68 (4.6%) with cardiopulmonary failure. Of the etiologically diagnosed 1 217 severe and fatal HFMD cases, 642 (52.8%) were with EV71, other enterovirus 261 (21.5%), Cox A16 36 (3.0%), 1 (0.1%) with both EV71 and Cox A16. However, 277 (22.8%) showed negative on any pathogenic virus. Complication (Z=3.15, P=0.002) and duration between onset and diagnosed as severe cases (Z=3.95, P<0.001) were shown as key factors related to treatment outcomes. Conclusions: Most severe HFMD cases appeared in boys, especially living in the rural areas. Frequently seen complications would include aseptic meningitis, non-brainstem encephalitis and brainstem encephalitis. EV71 was the dominant etiology for severe and fatal cases. Early diagnosis and complication control were crucial, related to the treatment outcome of HFMD.

[Human enterovirus infection status and clinical characteristics of 274 patients with viral encephalitis in Henan Province, 2011-2012].

Objective: To investigate human enterovirus (HEV) infection and clinical characteristics of viral encephalitis patients in Pingdingshan, Henan Province. Methods: Cerebrospinal fluid specimens and epidemiological information were collected from 274 viral encephalitis patients in the departments of pediatrics and neurology in hospitals in Pingdingshan, Henan Province, from April 2011 to August 2012. Patients with bacterial infections were excluded from the study. Demographic information was collected by questionnaires and clinical information was mainly obtained from hospital examinations. Viral RNA was extracted using magnetic bead extraction. Real-time RT-PCR was then performed for HEV, CV-A16, and EV-A71 testing. SPSS statistical software was statistical analyses. Significant differences were determined using the chi-squared test (P<0.05). Results: Among 274 cases of viral encephalitis, 180 cases (65.7%) were male and 94 cases were female (34.3%). The median age was 2.17 years. Approximately 61.3% (168) of patients were younger than 3 years of age. A total of 107 (39.1%), 2 (0.7%), and 42 (15.3%) cases were positive for HEV, CV-A16, and EV-A71, respectively. Eleven patients were younger than 6 months of age and one patient was co-infected with HEV and EV-A71. In the<3, 3-5, 6-15, and>15 years old age groups, HEV infections comprised 31.5% (53/168), 52.9% (18/34), 53.0% (35/66), and 16.7% (1/6) (χ(2)=13.10, P=0.003), respectively. The EV-A71 infection rates were 17.9% (30/168), 23.5% (8/34), 6.1% (4/66), and 0 (χ(2)=8.04, P=0.045), respectively. The other enterovirus (OEV) infection rates were 12.5% (21/168), 29.4% (10/34), 48.5% (32/66), and 16.7% (1/6) (χ(2)=35.19, P<0.001), respectively. The rate of vomiting in OEV and EV-A71 infected patients was 73% (44/60) and 26% (11/42), respectively, while the frequency of skin rash in OEV and EV-A71 infected patients was 32% (19/60) and 79% (33/42), respectively. Approximately 95% (99/104) of patients infected with HEV had a fever, and the breathing rhythm change rate was 19% (20/104), which was lower than that of patients without HEV infection (36.8% (60/163)) (χ(2)=9.35, P=0.002). Conclusion: In Pingdingshan, HEV was a major causative agent of viral encephalitis and the rate of OEV infection was high, especially in children aged 3-15 years old. Fever was a common clinical symptom of patients infected with HEV. Patients infected with OEV primarily exhibited vomiting symptoms and EV-A71 infected patients showed skin rash.

The effect of immunoglobulin treatment for hemolysis on the incidence of necrotizing enterocolitis - a meta-analysis.

OBJECTIVE: The application of intravenous immune globulin (IVIG) has been recommended for treating hemolysis in neonates for several years. But in clinical work, more than one study reported that IVIG treatment maybe increased the risk of NEC in hemolytic patients. In light of this situation, we performed this meta-analysis. MATERIALS AND METHODS: We searched in PubMed, Embase, Cochrane databases for English references, and in Wanfang, VIP, Cnki databases for Chinese references (all last launched on 2015/12/18). Ultimately, 5 studies (Including 4 Chinese articles) were incorporated into this meta-analysis. Odds ratio (OR) and weighted mean difference (WMD) were calculated using a random-effects or fixed-effects model, depending on the data type and heterogeneity of the included studies. RESULTS: (1) Baseline data including gestational age, gender and TBil between IVIG and control groups were compared in hemolytic infants, and showed no significance. (2) With respect to possible inducement of NEC, SGA and formula feeding were found no significance between IVIG and control groups. In contrast, birth weight was found significantly different between the two groups (WMD = 33.35; 95% CI, 20.70-46.01; p < 0.00001). (3) Regarding the incidence of NEC and mortality, the result showed that there was a significant difference between the IVIG and the control groups in the risk of NEC (OR: 4.53; 95% CI, 2.34-8.79; p < 0.00001). CONCLUSIONS: Our results indicate that IVIG treatment for hemolysis may increase the risk of NEC in infants. But it does not increase the risk of final mortality.

[Effect of umbilical cord mesenchymal stem cell transplantation on immune function and prognosis of patients with decompensated hepatitis B cirrhosis].

Objective: To investigate the effect of human umbilical cord mesenchymal stem cells (hUCMSCs) on the immune function and prognosis of patients with decompensated hepatitis B cirrhosis. Methods: A total of 65 patients with decompensated hepatitis B cirrhosis were divided into observation group and control group. The patients in the observation group were given intervention (via the proper hepatic artery or the portal vein) and intravenous infusion of 4×108 hUCMSCs in two doses, as well as the same basic treatment as in the control group. The patients in the control group were given conventional medical treatment. ELISA as used to measure the serum levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNFα), interleukin-10 (IL-10), and transforming growth factor-ß (TGFß) in the observation group before surgery and at 1 week after surgery, as well as the serum levels of IL-6, TNFα, IL-10, and TGFß in the control group on admission and at 1 week after admission. Flow cytometry was used to measure the percentage of lymphocyte subsets in the observation group before surgery and at 1 week after surgery, as well as that in the control group on admission and at 1 week after admission. In addition, the patients' prognosis and major complications during hospitalization were observed in both groups, and the patients were followed up for 24 weeks to record the number of deaths. The t-test was used for comparison of continuous data, and the chi-square test was used for comparison of categorical data which were expressed as percentages. Results: At 1 week after the transplantation of hUCMSCs, compared with the control group, the observation group had significant reductions in the serum levels of IL-6 and TNFα and significant increases in the serum levels of IL-10 and TGFß (all P < 0.001), as well as significant increases in the percentages of T4 cells and Treg cells and significant reductions in the percentages of T8 cells and B cells (all P < 0.05). There were no significant differences in the changes in T3 cells and natural killer cells between the two groups (P > 0.05). Compared with the control group, the observation group had a significantly lower probability of progression to liver failure (6.45% vs 14.71%, P = 0.017). Conclusion: In the treatment of patients with decompensated hepatitis B cirrhosis, transplantation of UCMSCs can inhibit the proliferation of T cells and B cells and the differentiation of T8 cells, upregulate Treg cells, promote the secretion of immunosuppressive cytokines, and reduce the production of inflammatory cytokines. Therefore, it can alleviate liver inflammatory response and liver cell damage and reduce the probability of hepatic failure.

Hepatitis C virus in Mexican Americans: a population-based study reveals relatively high prevalence and negative association with diabetes.

This study aimed to estimate the prevalence and risk factors for hepatitis C virus (HCV) infection in Mexican Americans living in South Texas. We tested plasma for the presence of HCV antibody from the Cameron County Hispanic Cohort (CCHC), a randomized, population-based cohort in an economically disadvantaged Mexican American community on the United States/Mexico border with high rates of chronic disease. A weighted prevalence of HCV antibody of 2·3% [n = 1131, 95% confidence interval (CI) 1·2-3·4] was found. Participants with diabetes had low rates of HCV antibody (0·4%, 95% CI 0·0-0·9) and logistic regression revealed a statistically significant negative association between HCV and diabetes (OR 0·20, 95% CI 0·05-0·77) after adjusting for sociodemographic and clinical factors. This conflicts with reported positive associations of diabetes and HCV infection. No classic risk factors were identified, but important differences between genders emerged in analysis. This population-based study of HCV in Mexican Americans suggests that national studies do not adequately describe the epidemiology of HCV in this border community and that unique risk factors may be involved.

Phase II study of sorafenib in combination with cisplatin and 5-fluorouracil to treat recurrent or metastatic nasopharyngeal carcinoma.

BACKGROUND: We aimed to investigate the efficacy and tolerability of sorafenib combined with cisplatin and 5-fluorouracil (5-FU) in patients with recurrent or metastatic nasopharyngeal carcinoma (NPC). PATIENTS AND METHODS: It was a Simon two-stage designed trial. Chemotherapy-naive patients with recurrent or metastatic disease were enrolled. The regimen was sorafenib 400 mg orally b.i.d., cisplatin 80 mg/m(2) i.v. day 1, and 5-FU 1000 mg/m(2)/day CIV for 4 days, repeated every 21 days. After a maximum of six cycles of chemotherapy, patients received maintenance of sorafenib. RESULTS: In total, 54 patients were enrolled. The objective response rate reached 77.8%, including 1 complete response and 41 partial responses. The median progression-free survival was 7.2 months (95% CI 6.8-8.4 months), and the median overall survival was 11.8 months (95% CI 10.6-18.7 months). Major toxic effects included hand-foot skin reaction, myelosuppression, and gastrointestinal (GI) reaction. The incidence of hemorrhage was 22.2%, and one patient with liver metastases died of GI bleeding. Contrast-enhanced ultrasonography was carried out in a subset of patients with liver metastases. CONCLUSION: Combination of sorafenib, cisplatin (80 mg/m(2)) and 5-FU (3000 mg/m(2)) was tolerable and feasible in recurrent or metastatic NPC. Further randomized trials to compare sorafenib plus cisplatin and 5-FU with standard dose of cisplatin plus 5-FU in NPC are warranted.

Variation of respiratory resistance suggests optimization of airway caliber.

Physiologically optimized processes, such as respiration, walking, and cardiac function, usually show a range of variability about the optimized value. Airway resistance has, in the past, been noted as variable, and this variability has been connected to pulmonary disease (e.g., asthma). A hypothesis was presented many years ago that postulated airway resistance as an optimized parameter in healthy individuals, and we have noticed that respiratory measurements made with the airflow perturbation device (APD) tend to be variable in nature. It was posited that this variability indicates that respiratory resistance is optimized similarly to other physiological processes. Fifty subjects with a wide range of demographics volunteered to have 100 measurements made of their respiratory resistances. Resistances were separated into inhalation and exhalation phases. These were plotted and shown to have frequency distributions that were consistent with expectations for an optimized process. The frequency distributions were not quite symmetrical, being skewed slightly toward upper resistances. Comparison between subject data and data from a mechanical respiratory analog showed that subject resistance variation is overwhelmingly from the respiratory system and not from the APD.

Abuse and dependence on prescription opioids in adults: a mixture categorical and dimensional approach to diagnostic classification.

BACKGROUND: For the emerging DSM-V, it has been recommended that dimensional and categorical methods be used simultaneously in diagnostic classification; however, little is known about this combined approach for abuse and dependence. METHOD: Using data (n=37 708) from the 2007 National Survey on Drug Use and Health (NSDUH), DSM-IV criteria for prescription opioid abuse and dependence among non-prescribed opioid users (n=3037) were examined using factor analysis (FA), latent class analysis (LCA, categorical), item response theory (IRT, dimensional), and factor mixture (hybrid) approaches. RESULTS: A two-class factor mixture model (FMM) combining features of categorical latent classes and dimensional IRT estimates empirically fitted more parsimoniously to abuse and dependence criteria data than models from FA, LCA and IRT procedures respectively. This mixture model included a severely affected group (7%) with a comparatively moderate to high probability (0.32-0.88) of endorsing all abuse and dependence criteria items, and a less severely affected group (93%) with a low probability (0.003-0.16) of endorsing all criteria. The two empirically defined groups differed significantly in the pattern of non-prescribed opioid use, co-morbid major depression, and substance abuse treatment use. CONCLUSIONS: A factor mixture model integrating categorical and dimensional features of classification fits better to DSM-IV criteria for prescription opioid abuse and dependence in adults than a categorical or dimensional approach. Research is needed to examine the utility of this mixture classification for substance use disorders and treatment response.

The management of hepatitis C.

Hepatitis C is a serious public health problem with more than 170 million chronic carriers worldwide. Although hepatitis C infection can be cured in up to 40% of patients, current treatment is not ideal and is associated with a wide spectrum of side effects and complications. Therefore, emerging evidence suggests that patients can receive tailored therapy based on their viral kinetic changes during treatment. With better knowledge of hepatitis C viral genome and life cycle, compounds so called ''Specifically Targeted Antiviral Therapy for HCV or STAT-C'' are under development. This review will discuss current therapies and recent advances in new therapies for hepatitis C.

Is sonographic surveillance of polytetrafluoroethylene-covered transjugular intrahepatic portosystemic shunts (TIPS) necessary? A single centre experience comparing both types of stents.

AIM: To investigate whether sonographic (US) surveillance of polytetrafluoroethylene covered transjugular intrahepatic portosystemic shunts (TIPS) is necessary. MATERIALS AND METHODS: We identified 128 patients who underwent TIPS for complications of portal hypertension between January 2001 and December 2005 at a large tertiary centre. Procedural data were retrospectively analysed. US surveillance of the TIPS was performed at baseline with scheduled follow-up or whenever shunt dysfunction was suspected. Clinical and radiology reports were compared to assess US surveillance of the TIPS. RESULTS: Four hundred and twenty-six US studies were performed, with a median of three per patient (range 1-5). The median follow-up period was 378 days (range 1-1749 days). Twenty-three patients (18%) had baseline US studies performed only whereas 105 (82%) also had follow-up studies. Forty-one (32%) of 128 patients [32 (78%) Wallstent, nine (22%) Viatorr] had Doppler ultrasound abnormalities noted. Venography was performed in all 41 patients. Abnormal venography and elevated hepatic venous pressure gradient (HVPG) was seen in 34 (82.9%) of the 41 patients [29 (85.3%) Wallstent, five (14.7%) Viatorr]. Among the 34 patients, 17 (50%) [13 (76.5%) Wallstent, four (23.5%) Viatorr] had venographic abnormalities noted at the hepatic venous end accompanied by increased HVPG. All four of the Viatorr patients had minor narrowing at the hepatic venous end and HVPG measurements that ranged 3-4 mm Hg above 12 mm Hg. CONCLUSION: Considering the improved patency of covered stents in TIPS, US surveillance may be superfluous after the baseline study.

Determination of the absolute configurations of natural products using TDDFT optical rotation calculations: the iridoid oruwacin.

We report the determination of the absolute configuration (AC) of the iridoid natural product oruwacin by comparison of the optical rotations, [alpha] D, of its two enantiomers, calculated using time-dependent density functional theory (TDDFT), to the experimental [alpha] D value, +193. Conformational analysis of oruwacin using density functional theory (DFT) identifies eight conformations which are significantly populated at room temperature. [alpha] D values of these eight conformations are calculated using TDDFT at the B3LYP/aug-cc-pVDZ//B3LYP/6-31G* level, leading to the conformationally averaged [alpha] D values of -193 for the (1 R,5 S,8 S,9 S,10 S)-enantiomer and +193 for the (1 S,5 R,8 R,9 R,10 R)-enantiomer. Comparison of the calculated [alpha] D values to the value of the natural product proves that naturally occurring oruwacin has the AC 1 S,5 R,8 R,9 R,10 R. This AC is opposite to that assigned by Adesogan by comparison of the [alpha] D of oruwacin to that of the iridoid plumericin. Our results show that the assignment of the AC of a natural product by comparison of its [alpha] D to that of a chemically related molecule can be unreliable and should not be assumed to be definitive.

Determination of the absolute configurations of natural products via density functional theory calculations of vibrational circular dichroism, electronic circular dichroism, and optical rotation: the iridoids plumericin and isoplumericin.

The absolute configurations (ACs) of the iridoid natural products, plumericin (1) and isoplumericin (2), have been re-investigated using vibrational circular dichroism (VCD) spectroscopy, electronic circular dichroism (ECD) spectroscopy, and optical rotatory dispersion (ORD). Comparison of DFT calculations of the VCD spectra of 1 and 2 to the experimental VCD spectra of the natural products, (+)-1 and (+)-2, leads unambiguously to the AC (1R,5S,8S,9S,10S)-(+) for both 1 and 2. In contrast, comparison of time-dependent DFT (TDDFT) calculations of the ECD spectra of 1 and 2 to the experimental spectra of (+)-1 and (+)-2 does not permit definitive assignment of their ACs. On the other hand, TDDFT calculations of the ORD of (1R,5S,8S,9S,10S)-1 and -2 over the range of 365-589 nm are in excellent agreement with the experimental data of (+)-1 and (+)-2, confirming the ACs derived from the VCD spectra. Thus, the ACs initially proposed by Albers-Schönberg and Schmid are shown to be correct, and the opposite ACs recently derived from the ECD spectra of 1 and 2 by Elsässer et al. are shown to be incorrect. As a result, the ACs of other iridoid natural products obtained by chemical correlation with 1 and 2 are not in need of revision.