Low values of left ventricular ejection time in the post-anhepatic phase may be associated with occurrence of primary graft dysfunction after orthotopic liver transplantation: results of a single-centre case-control study

BACKGROUND

Previous investigations on risk factors for orthotopic liver transplantation (OLT) surgery have not analyzed hemodynamic aberrations in great detail. Moreover, the usefulness of esophageal Doppler monitoring has not been extensively studied in this clinical setting. The aim of this study was to evaluate if the occurrence of primary graft dysfunction (PGD) may be anticipated by hemodynamic indexes measured by esophageal Doppler (ED) monitoring system as well as by pulmonary artery catheter (PAC) in patients undergoing OLT.

MATERIALS AND METHODS

38 OLT recipients were studied. Patients with acute liver failure or having non treated esophageal varices and those transplanted with marginal donors were excluded from the study. The haemodynamic data - measured by ED monitoring system (HemosonicTM 100, Arrow, OK, USA) and PAC - collected at the following 3 time points were considered for statistical analysis: 30 minutes after the induction of anesthesia but before skin incision, T0; 20 minutes after liver dissection, T1; at the beginning of biliary reconstruction, T2. On the basis of early outcome (72 hours after OLT), patients were distinguished into two groups: those with PGD (grade III-IV of Toronto classification) and those without PGD (grade I-II).

RESULTS

LVETc (left ventricular ejection time) values, registered at the beginning of biliary reconstruction (T2), were lower in patients with PGD compared to those without PGD (p < 0.000), while there were no differences in hemodynamic parameters derived from PAC between the two groups.

CONCLUSIONS

Since LVETc is related to preload, the results of this study would suggest that normovolemia could be the end point of a fluid replacement strategy in OLT setting.

High incidence of skin cancer in the Channel Islands

BACKGROUND

Previous studies looking at rates of malignant melanoma (MM) and nonmelanoma skin cancer (NMSC) in the UK have documented one of the highest rates in the southwest of England; however, the incidence of these tumours in Guernsey and Jersey, two of the Channel Islands, has not previously been reported.

AIMS

To determine the incidence of cutaneous MM and NMSC in the Channel Islands.

METHODS

Data for the period 2005-2009 were obtained from clinical and histopathological records for all MMs excised in the Channel Islands, and from the South-west Cancer Registry for MMs excised in the southwest of England and for NMSCs in both areas. The age-standardized incidence rate (ASRs) per 100,000 of the population in the Channel Islands were compared with those with the southwest of England, the UK and the rest of Europe where available. The MM characteristics of the Channel Islands were then compared with the southwest of England using standardized incidence ratios (SIRs).

RESULTS

The ASR/100,000 for cutaneous MM for 2005-2009 was 30 for the Channel Islands (31.3 for Jersey, 28.2 for Guernsey), 20.3 for the southwest of England, and 15.6 for the UK. Comparison with the rest of Europe indicated that the incidence of MM in the Channel Islands is one of the highest in Europe. The highest incidence of MM was in the over 65 years age group on both Guernsey and Jersey, and when divided into 5-year age bands, the 70-74 years age group had the highest rate. This suggests that this particular age group may have previously received greater exposure to some environmental factor that promotes MM development. The ASR/100,000 for NMSC was also higher for the Channel Islands (263.3) than for the southwest of England (174.6) for 2005-2009, and for the UK in 2009 (104.9).

CONCLUSIONS

This study indicates that the Channel Islands have a high incidence of skin cancer (both MM and NMSC). In addition, the data show that the ASRs in older people in this population group differ from those in mainland UK, showing higher rates in the over 65 years age group.

Ready access to illicit drugs among youth and adult users

BACKGROUND

Current drug-control strategies in Canada focus funding and resources predominantly on drug law enforcement, often at the expense of preventive, treatment, and harm reduction efforts. This study aimed to examine the availability of the most commonly used substances in Vancouver, Canada after the implementation of such strategies.

METHODS

Using data from two large cohorts of drug-using youth and adults in Vancouver from the calendar year 2007, we assessed perceived availability of heroin, crack, cocaine, crystal methamphetamine, and marijuana.

RESULTS

Compared to youth (n= 330), a greater proportion of adults (n= 1,160) reported immediate access (ie, within 10 minutes) to heroin (81.0% vs. 55.9%, p < .001), crack (90.4% vs. 69.3%, p < .001), and cocaine (83.7% vs. 61.1%, p < .001). Conversely, larger proportions of youth reported immediate access to crystal methamphetamine (62.8% vs. 39.4%, p < .001) and marijuana (88.4% vs. 73.2%, p < .001) compared to adult users.

CONCLUSIONS

Regardless of differences in illicit drug availability by age, all drugs are readily accessed in Vancouver despite drug law enforcement efforts. This includes drugs that are frequently injected and place users at risk of human immunodeficiency virus (HIV) infection and transmission of other blood-borne disease.

MAT1A variants modulate the effect of dietary fatty acids on plasma homocysteine concentrations

BACKGROUND AND AIM

Dietary n-3 polyunsaturated fatty acids (PUFAs) are associated with decreased plasma homocysteine (Hcy), an important biomarker for cardiovascular disease. The S-adenosylmethionine synthetase type-1 (MAT1A), an essential enzyme in the conversion of methionine to S-adenosylmethionine, plays a key role in homocysteine metabolism. This study investigated the interaction between dietary fatty acids and MAT1A genotypes on plasma Hcy concentrations among Boston Puerto Ricans.

METHODS AND RESULTS

Plasma Hcy and MAT1A genotypes were determined in 994 subjects of the Boston Puerto Rican Health Study. Dietary fatty acid intakes were assessed by interviews using a questionnaire adapted from the NCI/Block food frequency form.

RESULT

In the cross-sectional analysis, genetic variant MAT1A 3U1510 displayed a significant interaction with dietary n-3:n-6 PUFA ratio in determining plasma Hcy (p-value for interaction = 0.025). 3U1510G homozygotes had significantly lower plasma Hcy concentration than major allele homozygotes and heterozygotes (AA + AG) (p-value for trend = 0.019) when the n-3:n-6 ratio was >0.09. Two other MAT1A variants, d18777 and i15752, also showed significant interactions with different constituents of dietary fat influencing Hcy concentrations. Furthermore, haplotypes consisting of three variants displayed a strong interaction with n3:n6 ratio influencing Hcy concentrations.

CONCLUSIONS

Our results suggest that MAT1A genotypes appear to modulate effects of dietary fat on plasma Hcy.

The MMP-9/TIMP-1 axis controls the status of differentiation and function of myelin-forming Schwann cells in nerve regeneration

Background

Myelinating Schwann cells (mSCs) form myelin in the peripheral nervous system. Because of the works by us and others, matrix metalloproteinase-9 (MMP-9) has recently emerged as an essential component of the Schwann cell signaling network during sciatic nerve regeneration.

Methodology/Principal Findings

In the present study, using the genome-wide transcriptional profiling of normal and injured sciatic nerves in mice followed by extensive bioinformatics analyses of the data, we determined that an endogenous, specific MMP-9 inhibitor [tissue inhibitor of metalloproteinases (TIMP)-1] was a top up-regulated gene in the injured nerve. MMP-9 capture followed by gelatin zymography and Western blotting of the isolated samples revealed the presence of the MMP-9/TIMP-1 heterodimers and the activated MMP-9 enzyme in the injured nerve within the first 24 h post-injury. MMP-9 and TIMP-1 co-localized in mSCs. Knockout of the MMP-9 gene in mice resulted in elevated numbers of de-differentiated/immature mSCs in the damaged nerve. Our comparative studies using MMP-9 knockout and wild-type mice documented an aberrantly enhanced proliferative activity and, accordingly, an increased number of post-mitotic Schwann cells, short internodes and additional nodal abnormalities in remyelinated nerves of MMP-9 knockout mice. These data imply that during the first days post-injury MMP-9 exhibits a functionally important anti-mitogenic activity in the wild-type mice. Pharmacological inhibition of MMP activity suppressed the expression of Na_v1.7/1.8 channels in the crushed nerves.

Conclusion/Significance

Collectively, our data established an essential role of the MMP-9/TIMP-1 axis in guiding the mSC differentiation and the molecular assembly of myelin domains in the course of the nerve repair process. Our findings of the MMP-dependent regulation of Na_v channels, which we document here for the first time, provide a basis for therapeutic intervention in sensorimotor pathologies and pain.

Assessing fibromyalgia-related fatigue: content validity and psychometric performance of the Fatigue Visual Analog Scale in adult patients with fibromyalgia

OBJECTIVES

To document 1) the content validity and 2) measure improvements in fatigue, using the Fatigue Visual Analogue Scale (VAS) assessment tool in patients with fibromyalgia.

METHODS

The relevance and comprehensiveness of the Fatigue VAS were tested through a qualitative analysis of 20 subjects' verbatim transcripts from semi-structured qualitative interviews. Data from two randomised, controller trials in fibromyalgia (n=1121) were used to conduct correlation analyses with the Fatigue and Tiredness items from the Fibromyalgia Impact Questionnaire (FIQ) and the Short Form-36 Vitality scale. Known-groups and cross classification analyses were conducted to demonstrate the ability to measure improvement in fatigue using the Fatigue VAS.

RESULTS

All subjects spontaneously reported that fatigue was an important symptom to capture in fibromyalgia. The Fatigue VAS was well understood by most subjects (n=18/20). High correlations (Pearson r>0.75) and good agreement (k>0.66) were found between the Fatigue VAS and the FIQ tiredness items no. 16 and 17 and SF-36™ Vitality scale. In both clinical trials there was a substantial separation of approximately 20 points on the mean change in the Fatigue VAS score between responders (>30% improvement in pain VAS) and non-responders.

CONCLUSIONS

Previous studies have confirmed that fatigue is a major component of the fibromyalgia experience. This current study reports that fibromyalgia patients spontaneously rated fatigue as a highly significant feature of their illness, and supports the use of the Fatigue VAS as a valid questionnaire in fibromyalgia clinical trials.

Use of North America's first medically supervised safer injecting facility among HIV-positive injection drug users

The objective of this study was to examine supervised injecting facility (SIF) use among a cohort of 395 HIV-positive injection drug users (IDUs) in Vancouver, Canada. The correlates of SIF use were identified using generalized estimating equation analyses. In multivariate analyses, frequent SIF use was associated with homelessness (adjusted odds ratio [AOR] = 1.90), daily heroin injection (AOR = 1.56), and daily cocaine injection (AOR = 1.59). The reasons given for not using the SIF included a preference for injecting at home and already having a safe place to inject. The SIF services most commonly used were needle exchange and nursing services. The SIF appears to have attracted a high-risk subpopulation of HIV-positive IDUs; this coverage perhaps could be extended with the addition of HIV-specific services such as disease monitoring and the provision of antiretroviral therapy.

The validity of reporting willingness to use a supervised injecting facility on subsequent program use among people who use injection drugs

BACKGROUND

Innovative health programs for injection drug users (IDUs), such as supervised injecting facilities (SIFs), are often preceded by evaluations of IDUs' willingness to use the service. The validity of these surveys has not been fully evaluated. We sought to determine whether measures of willingness collected prior to the opening of a Canadian SIF accurately predicted subsequent use of the program.

METHODS

Data were derived from a prospective cohort of IDUs. The sample size for this study was 640 IDUs. Using multivariate logistic regression, it was assessed if a history of reporting willingness to use the program, were it available, was associated with subsequent use. In sub-analysis restricted to individuals who had a history of reported willingness, we used multivariate longitudinal analysis to identify factors associated with not attending the SIF.

RESULTS

Among 442 IDUs, 72% of those who reported initial willingness to use a SIF later attended the program, and a prior willingness to use a SIF significantly predicted later attendance (adjusted odds ratio = 1.67). In sub-analyses restricted to those who had a history of reporting willingness to use the SIF, not using the program was predicted by not frequenting the neighborhood where the SIF was located.

CONCLUSION

Our findings indicate that reported willingness measures collected from IDUs regarding potential SIF program participation prior to its opening independently predicted later attendance even when variables that were likely determinants of willingness were adjusted for. These data suggest that willingness measures are reasonably valid tools for planning the delivery of health services among IDU populations.