Nutritional considerations in adult cardiothoracic surgical patients

The importance of the preoperative nutritional status of cardiothoracic surgical patients in determining outcomes is demonstrated and discussed. Demographic, anthropometric, and biochemical changes in patients undergoing cardiothoracic surgery increase the importance of identifying those at risk for postoperative complications resulting from malnutrition. The interrelationships of chronic heart failure, cardiac cachexia, nutritional status, and nutritional support are identified and emphasized. The complexities of myocardial energetics and metabolism are outlined together with the nutrient needs for patients undergoing cardiac, pulmonary, or other intrathoracic operative procedures.     

Cholesteryl ester storage disease of clinical and genetic characterisation: A case report and review of literature

BACKGROUND Cholesteryl ester storage disease(CESD)is a rare genetic disease.Its symptoms and severity are highly variable.CESD is a systemic disease that can lead to the accumulation of fat and inflammation in the liver,as well as gastrointestinal and cardiovascular disease.The majority of patients require liver transplantation due to decompensated cirrhosis.Enzyme replacement therapy has been approved based on a randomized trial.Our study aims to clinically and genetically evaluate two siblings with CESD who underwent liver transplantation,as well as their first-degree family members.CASE SUMMARY The siblings were compound heterozygous for the missense variant in LIPA exon 8,c.894G>A,(p.Gln298Gln)and a single base pair deletion,c.482del(p.Asn161Ilefs*19).Analyses of single nucleotide polymorphisms showed variants with an increased risk of fatty liver disease and fibrosis for both patients.Clinically,both patients show signs of recurrence of CESD in the liver after transplantation and additional gastrointestinal and cardiovascular signs of CESD.Three family members who were LIPA heterozygous had a lysosomal acid lipase activity below the reference value.One of these carriers,a seven-year-old boy,was found to have severe dyslipidemia and was subsequently treated with statins.CONCLUSION Our study underlines that CESD is a multi-organ disease,the progression of which may occur post-liver transplantation.Our findings underline the need for monitoring of complications and assessment of possible further treatment.     

Hyperoxia but not ambient pressure decreases tetrahydrobiopterin level without affecting the enzymatic capability of nitric oxide synthase in human endothelial cells

Nitric oxide (NO) seems to be related to bubble formation and endothelial dysfunction resulting in decompression sickness. Bubble formation can be affected by aerobic exercise or manipulating NO. A prior heat stress (HS) has been shown to confer protection against decompression sickness in rats. An important question was if the oxidative environment experienced during diving limits the availability of the nitric oxide synthase (NOS) cofactor tetrahydrobiopterin (BH4). Human endothelial cells were used to investigate how HS and simulated diving affected NO synthesis and defense systems such as heat shock protein 70 (HSP70) and glutathione (GSH). BH4 was measured using a novel LC–MS/MS method and NOS by monitoring the conversion of radiolabeled l-arginine to l-citrulline. Increased pO₂ reduced BH4 levels in cells in a dose-dependent manner independently of high pressure. This effect may result in decreased generation of NO by NOS. The BH4 decrease seemed to be abolished when cells were exposed to HS prior to hyperoxia. NOS enzyme was unaffected by increased pO₂ but substantially reduced after HS. The BH4 level seemed to a minor extent to be dependent upon GSH and probably to a higher degree dependent on other antioxidants such as ascorbic acid. A simulated dive at 60 kPa O₂ had a potentiating effect on the heat-induced HSP70 expression, whereas GSH levels were unaffected by hyperoxic exposure. HS, hyperoxia, and dive affected several biochemical parameters that may play important roles in the mechanisms protecting against the adverse effects of saturation diving.     

Research digest

Alzheimer's disease is a degenerative disease characterised by a progressive loss of cognitive functions and impairment of activities of daily living severe enough to interfere with normal functioning. To help persons with this disease perform a variety of activities, our research team developed AP@LZ, an electronic organiser specifically designed for them. Two participants with Alzheimer's disease learned how to use AP@LZ in their daily lives by following a structured learning method. After the learning phase, the participants were able to use AP@LZ efficiently and facilitate their day-to-day activities for several months, despite the steady progression of the disease. These results suggest that persons with Alzheimer's disease can learn to use new technologies to compensate for their everyday memory problems, which opens up new rehabilitation possibilities in dementia care.     

Prospective measurements of dehydroepiandrosterone sulfate in a cohort of elderly subjects: Relationship to gender, subjective health, smoking habits, and 10-year mortality

The decrease with age of the adrenal-secreted dehydroepiandrosterone sulfate (DHEAS) in serum has suggested that it may be causally related to longevity. For the PAQUID [People (Personnes) Aged (Agées) About What (Quid, in Latin)] cohort of elderly subjects, we have previously reported higher DHEAS in men than in women, a decrease with age and, among men, a negative correlation between the DHEAS level and mortality at 2 and 4 years. Here, with an 8-year followup in 290 subjects, we show a global decrease of 2.3% per year for men and 3.9% per year for women. However, in approximately 30% of cases, there was an increase of DHEAS. We observed no relationship between the evolution of DHEAS level and functional, psychological, and mental status, possibly because of selection by death. In women, no association was found between mortality and DHEAS level. In men, the relative risk (RR) of death was higher for the lowest levels of DHEAS (RR = 1.9, P = 0.007), with RR = 6.5, P = 0.003 for those under 70 years old, a result indicating heterogeneity of the population. There was an effect of subjective health on mortality that disappeared after adjustment of DHEAS levels, suggesting its relation with these DHEAS levels. Death RR was much higher in smokers with a low DHEAS level than in nonsmokers with high DHEAS (RR = 6.7, P = 0.001). We submit that the involvement of DHEAS is possibly different according to gender, that association between low DHEAS level and mortality only for men under 70 years old possibly reflects heterogeneity of the population, and that DHEAS level is a reliable predictor of death in male smokers.     

X-linked dominant chondrodysplasia with platyspondyly, distinctive brachydactyly, hydrocephaly, and microphthalmia

We describe a family with an X-linked dominant chondrodysplasia. Four males and six females were affected through four generations. Identification of skeletal abnormalities and hydrocephaly during the pregnancy of three male fetuses led to termination of the pregnancies. A fourth affected male died at 6 days of life. The four patients had chondrodysplasia, hydrocephaly, and facial features with microphthalmia. Radiographs showed severe platyspondyly and various bone abnormalities including a distinctive metaphyseal cupping of the metacarpals, metatarsals, and phalanges. The affected females were less affected and showed small stature, sometimes associated with body asymmetry and mild mental retardation. This condition appears to be a previously unrecognized X-linked dominant chondrodysplasia.     

Detection and identification of Ehrlichia spp. in ticks collected in Tunisia and Morocco

A broad-range 16S rRNA gene PCR assay followed by partial sequencing of the 16S rRNA gene was used for the detection of members of the family Anaplasmataceae in ticks in North Africa. A total of 418 questing Ixodes ricinus ticks collected in Tunisia and Morocco, as well as 188 Rhipicephalus ticks from dogs and 52 Hyalomma ticks from bovines in Tunisia, were included in this study. Of 324 adult I. ricinus ticks, 16.3% were positive for Ehrlichia spp., whereas only 3.4 and 2.8% of nymphs and larvae, respectively, were positive. A large heterogeneity was observed in the nucleotide sequences. Partial sequences identical to that of the agent of human granulocytic ehrlichiosis (HGE) were detected in I. ricinus and Hyalomma detritum, whereas partial sequences identical to that of Anaplasma platys were detected in Rhipicephalus sanguineus. However, variants of Anaplasma, provisionally designated Anaplasma-like, were predominant in the I. ricinus tick population in Maghreb. Otherwise, two variants of the genus Ehrlichia were detected in I. ricinus and H. detritum. Surprisingly, a variant of Wolbachia pipientis was evidenced from I. ricinus in Morocco. These results emphasized the potential risk of tick bites for human and animal populations in North Africa.     

Understanding tuberculosis epidemiology using structured statistical models

Molecular epidemiological studies can provide novel insights into the transmission of infectious diseases such as tuberculosis. Typically, risk factors for transmission are identified using traditional hypothesis-driven statistical methods such as logistic regression. However, limitations become apparent in these approaches as the scope of these studies expand to include additional epidemiological and bacterial genomic data. Here we examine the use of Bayesian models to analyze tuberculosis epidemiology. We begin by exploring the use of Bayesian networks (BNs) to identify the distribution of tuberculosis patient attributes (including demographic and clinical attributes). Using existing algorithms for constructing BNs from observational data, we learned a BN from data about tuberculosis patients collected in San Francisco from 1991 to 1999. We verified that the resulting probabilistic models did in fact capture known statistical relationships. Next, we examine the use of newly introduced methods for representing and automatically constructing probabilistic models in structured domains. We use statistical relational models (SRMs) to model distributions over relational domains. SRMs are ideally suited to richly structured epidemiological data. We use a data-driven method to construct a statistical relational model directly from data stored in a relational database. The resulting model reveals the relationships between variables in the data and describes their distribution. We applied this procedure to the data on tuberculosis patients in San Francisco from 1991 to 1999, their Mycobacterium tuberculosis strains, and data on contact investigations. The resulting statistical relational model corroborated previously reported findings and revealed several novel associations. These models illustrate the potential for this approach to reveal relationships within richly structured data that may not be apparent using conventional statistical approaches. We show that Bayesian methods, in particular statistical relational models, are an important tool for understanding infectious disease epidemiology.     

Ixodes ricinus density, and distribution and prevalence of Borrelia burgdorferi sensu lato infection along an altitudinal gradient

In this study, we measured the phenology of Ixodes ricinus ticks and their infection with Borrelia burgdorferi sensu lato (sl) simultaneously along an altitudinal gradient to assess the impact of climate on the phenology of ticks and on their infection with B. burgdorferi sl. From 1999 to 2001, free-living I. ricinus ticks were collected monthly by flagging vegetation at three different altitudes (620, 740, and 900 m above sea level) on the slope of a mountain in Chaumont (Neuchatel, Switzerland). I. ricinus ticks were examined for the presence of B. burgdorferi sl by using direct fluorescent antibody assay and isolation of spirochetes. Borrelia species were characterized by polymerase chain reaction followed by restriction fragment-length polymorphism. Tick density and tick phenology varied with altitude. Although the peak tick density decreased and the onset of ticks was delayed with altitude, the phenology was much more stable among years at the highest altitudes than at the lowest. The prevalence of B. burgdorferi infection in nymphs and adults decreased with altitude. The prevalence of infection differed significantly among years, and it was significantly higher in adults (30%) than in nymphs (21%). B. burgdorferi infection in adults was positively related with adult density, but this was not observed for nymphs. Five B. burgdorferi sl genospecies were successfully isolated: B. garinii, B. burgdorferi sensu stricto, B. afzelii, B. valaisiana, and B. lusitaniae. Mixed infections were obtained from five of 140 infected ticks. The greatest diversity in Borrelia species was observed at the lowest altitude where all five Borrelia species were present, whereas at the two highest altitudes, B. lusitaniae was not observed.