Advances in microbial exoenzymes bioengineering for improvement of bioplastics degradation.

Plastic pollution has become a major global concern, posing numerous challenges for the environment and wildlife. Most conventional ways of plastics degradation are inefficient and cause great damage to ecosystems. The development of biodegradable plastics offers a promising solution for waste management. These plastics are designed to break down under various conditions, opening up new possibilities to mitigate the negative impact of traditional plastics. Microbes, including bacteria and fungi, play a crucial role in the degradation of bioplastics by producing and secreting extracellular enzymes, such as cutinase, lipases, and proteases. However, these microbial enzymes are sensitive to extreme environmental conditions, such as temperature and acidity, affecting their functions and stability. To address these challenges, scientists have employed protein engineering and immobilization techniques to enhance enzyme stability and predict protein structures. Strategies such as improving enzyme and substrate interaction, increasing enzyme thermostability, reinforcing the bonding between the active site of the enzyme and substrate, and refining enzyme activity are being utilized to boost enzyme immobilization and functionality. Recently, bioengineering through gene cloning and expression in potential microorganisms, has revolutionized the biodegradation of bioplastics. This review aimed to discuss the most recent protein engineering strategies for modifying bioplastic-degrading enzymes in terms of stability and functionality, including enzyme thermostability enhancement, reinforcing the substrate binding to the enzyme active site, refining with other enzymes, and improvement of enzyme surface and substrate action. Additionally, discovered bioplastic-degrading exoenzymes by metagenomics techniques were emphasized.

SLC19A1 Genetic Variation Leads to Altered Thiamine Diphosphate Transport: Implications for the Risk of Developing Wernicke-Korsakoff's Syndrome.

AIMS: Wernicke-Korsakoff syndrome (WKS) is commonly associated with chronic alcohol misuse, a condition known to have multiple detrimental effects on thiamine metabolism. This study was conducted to identify genetic variants that may contribute to the development of WKS in individuals with alcohol dependence syndrome through alteration of thiamine transport into cells. METHODS: Exome sequencing data from a panel of genes related to alcohol metabolism and thiamine pathways were analysed in a discovery cohort of 29 individuals with WKS to identify possible genetic risk variants associated with its development. Variant frequencies in this discovery cohort were compared with European frequencies in the Genome Aggregation Database browser, and those present at significantly higher frequencies were genotyped in an additional cohort of 87 alcohol-dependent cases with WKS and 197 alcohol-dependent cognitively intact controls. RESULTS: Thirty non-synonymous variants were identified in the discovery cohort and, after filtering, 23 were taken forward and genotyped in the case-control cohort. Of these SLC19A1:rs1051266:G was nominally associated with WKS. SLC19A1 encodes the reduced folate carrier, a major transporter for physiological folate in plasma; rs1051266 is reported to impact folate transport. Thiamine pyrophosphate (TPP) efflux was significantly decreased in HEK293 cells, stably transfected with rs1051266:G, under thiamine deficient conditions when compared with the efflux from cells transfected with rs1051266:A (P = 5.7 × 10-11). CONCLUSION: This study provides evidence for the role of genetic variation in the SLC19A1 gene, which may contribute to the development of WKS in vivo through modulation of TPP transport in cells.

Incidence of Adverse Reactions to Parenteral Thiamine in the Treatment of Wernicke's Encephalopathy, and Recommendations.

AIM: To offer an estimate of the incidence of anaphylactic reactions to parenteral products containing thiamine used in the treatment of Wernicke's encephalopathy (WE) and make recommendations. METHOD: Review of previously released data on some older products and parenteral thiamine use in some other countries; analysis of sales and adverse incident data on anaphylaxis for a contemporary parenteral product used in the UK, Pabrinex. RESULTS: It was difficult to estimate the incidence of related anaphylactic reactions to Pabrinex in the UK because the number of doses given is unknown. Sales data are only an approximation to doses given because for products with a limited shelf life not all product sold is administered. However, available data indicate that there have been 10 anaphylactic reactions to Pabrinex from between 5,431,235-6,651,947 patient-days (14,880-16,080 years) of treatment. CONCLUSION: It is reasonable to assume that the risk of anaphylaxis is low, and lower than for many other drugs. The risk-benefit ratio for administration is favourable given the potential severity of brain damage in Wernicke-Korsakoff (WK) syndrome. There is a need for international agreement on the reporting of anaphylaxis and on the optimum thiamine therapy for the treatment of WK syndrome. We make recommendations on how this might be achieved.

The Impact of Variable Wind Shear Coefficients on Risk Reduction of Wind Energy Projects.

Estimation of wind speed at proposed hub heights is typically achieved using a wind shear exponent or wind shear coefficient (WSC), variation in wind speed as a function of height. The WSC is subject to temporal variation at low and high frequencies, ranging from diurnal and seasonal variations to disturbance caused by weather patterns; however, in many cases, it is assumed that the WSC remains constant. This assumption creates significant error in resource assessment, increasing uncertainty in projects and potentially significantly impacting the ability to control gird connected wind generators. This paper contributes to the body of knowledge relating to the evaluation and assessment of wind speed, with particular emphasis on the development of techniques to improve the accuracy of estimated wind speed above measurement height. It presents an evaluation of the use of a variable wind shear coefficient methodology based on a distribution of wind shear coefficients which have been implemented in real time. The results indicate that a VWSC provides a more accurate estimate of wind at hub height, ranging from 41% to 4% reduction in root mean squared error (RMSE) between predicted and actual wind speeds when using a variable wind shear coefficient at heights ranging from 33% to 100% above the highest actual wind measurement.

Phenotypic heterogeneity in study populations may significantly confound the results of genetic association studies on alcohol dependence.

BACKGROUND: The interpretation of genetic studies on alcohol dependence may be confounded by the co-occurrence of substance dependence, psychiatric disorders and alcohol-related comorbidities, for example, cirrhosis. Significant single-marker and haplotypic associations between polymorphisms in the zinc finger gene, ZNF699, and alcohol dependence were reported in the Irish Affected Sib Pair Study of Alcohol Dependence population, one-third of whom had co-occurring substance dependence while 80% had identified psychiatric comorbidity. The aim of this study was to explore variant ZNF699 associations with alcohol dependence while exercising controls for potential confounders. METHODS: The study population was comprised of 1449 alcohol-dependent cases and 1283 population controls; all were of British or Irish ancestry. None of the cases had a history of dependence on other substances, and the frequency of comorbid depression was low. A separate, ancestry-matched cohort of 196 opioid-dependent cases was also included. Genotyping for the four previously identified SNPs of interest in ZNF699 was performed using K-Biosciences Competitive Allele Specific PCR. RESULTS: No single-marker associations were found between polymorphisms in ZNF699 and alcohol dependence per se. A significant allelic association was found between rs7254880 in ZNF699 and alcohol-related cirrhosis (n=292), using cases with no biopsy evidence of liver disease (n=314) as controls (P=0.013). Significant allelic associations were also found between rs12460279 (P=0.028), rs7252865 (P=0.012) and rs10854142 (P=0.016) in ZNF699 and opioid dependence. CONCLUSION: Phenotypic variation in study populations may contribute towards the nonreplication of genetic association studies on alcohol dependence; controls for recognised confounding variables should be exercised whenever possible.

Evaluation of Sleep Disorders in Patients With Severe Traumatic Brain Injury During Rehabilitation.

OBJECTIVE: To explore the presence and types of sleep disorders in chronic patients with severe traumatic brain injury (TBI) undergoing inpatient rehabilitation using formal diagnostic criteria based on the International Classification of Sleep Disorders, 2nd edition. DESIGN: Cross-sectional study. SETTING: Inpatient brain injury rehabilitation units. PARTICIPANTS: Chronic inpatients with severe TBI (N=30) were evaluated during rehabilitation. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants wore an actiwatch for 7 days and completed self-report measures on sleep, mood, fatigue, pain, and daytime sleepiness. RESULTS: Twenty participants (67%) had a sleep-wake cycle disturbance, of which 15 (50%) met diagnostic criteria for a sleep disorder. Diagnosed sleep disorders in the sample were insomnia (26.7%), posttraumatic hypersomnia (6.7%), delayed sleep phase syndrome (10%), irregular sleep-wake pattern disorder (3.3%), and periodic limb movement disorder (3.3%). Sleep quality was estimated by senior clinical staff as interfering with rehabilitation in 36.6% of the sample. Poor sleep quality was associated with greater anxiety, fatigue, and daytime sleepiness. CONCLUSIONS: Consistent with previous studies, the present study showed high levels of sleep-wake cycle disturbances in patients with severe TBI undergoing rehabilitation, which were associated with anxiety, fatigue, and daytime sleepiness. These findings highlight the importance of assessing and treating sleep problems in patients with TBI undergoing rehabilitation.

Genetic variants in or near ADH1B and ADH1C affect susceptibility to alcohol dependence in a British and Irish population.

Certain single nucleotide polymorphisms (SNPs) in genes encoding alcohol dehydrogenase (ADH) enzymes confer a significant protective effect against alcohol dependence syndrome (ADS) in East Asian populations. Recently, attention has focused on the role of these SNPs in determining ADS risk in European populations. To further elucidate these associations, SNPs of interest in ADH1B, ADH1C and the ADH1B/1C intergenic region were genotyped in a British and Irish population (ADS cases n = 1076: controls n = 1027) to assess their relative contribution to ADS risk. A highly significant, protective association was observed between the minor allele of rs1229984 in ADH1B and ADS risk [allelic P = 8.4 × 10(-6) , odds ratio (OR) = 0.26, 95 percent confidence interval, 0.14, 0.49]. Significant associations were also observed between ADS risk and the ADH1B/1C intergenic variant, rs1789891 [allelic P = 7.2 × 10(-5) , OR = 1.4 (1.2, 1.6)] and three non-synonymous SNPs rs698, rs1693482 and rs283413 in ADH1C. However, these associations were not completely independent; thus, while the ADH1B rs1229984 minor allele association was independent of those of the intergenic variant rs1789891 and the three ADH1C variants, the three ADH1C variants were not individually independent. In conclusion, the rare ADH1B rs1229984 mutation provides significant protection against ADS in this British and Irish population; other variants in the ADH gene cluster also alter ADS risk, although the strong linkage disequilibrium between SNPs at this location precluded clear identification of the variant(s) driving the associations.

Mammals of Australia's tropical savannas: a conceptual model of assemblage structure and regulatory factors in the Kimberley region.

We construct a state-and-transition model for mammals in tropical savannas in northern Australia to synthesize ecological knowledge and understand mammalian declines. We aimed to validate the existence of alternative mammal assemblage states similar to those in arid Australian grasslands, and to speculate on transition triggers. Based on the arid grassland model, we hypothesized that assemblages are partitioned across rainfall gradients and between substrates. We also predicted that assemblages typical of arid regions in boom periods would be prevalent in savannas with higher and more regular rainfall. Data from eight mammal surveys from the Kimberley region, Western Australia (1994 to 2011) were collated. Survey sites were partitioned across rainfall zones and habitats. Data allowed us to identify three assemblage states: State 0:--low numbers of mammals, State II:--dominated by omnivorous rodents and State III:--dominated by rodents and larger marsupials. Unlike arid grasslands, assemblage dominance by insectivorous dasyurids (State I) did not occur in savannas. Mammal assemblages were partitioned across rainfall zones and between substrates as predicted, but-unlike arid regions-were not related strongly to yearly rainfall. Mammal assemblage composition showed high regional stability, probably related to high annual rainfall and predictable wet season resource pulses. As a consequence, we speculate that perpetually booming assemblages in savannas allow top-down control of the ecosystem, with suppression of introduced cats by the dingo, the region's top predator. Under conditions of low or erratic productivity, imposed increasingly by intense fire regimes and introduced herbivore grazing, dingoes may not limit impacts of cats on native mammals. These interacting factors may explain contemporary declines of savanna mammals as well as historical declines in arid Australia. The cat-ecosystem productivity hypothesis raised here differs from the already-articulated cat-habitat structure hypothesis for mammal declines, and we suggest approaches for explicit testing of transition triggers for competing hypotheses.

Genetic and environmental interplay in risky drinking in adolescents: a literature review.

AIMS: The aim of the study was to review recent research on the interplay between genes, environment and epigenetic factors in risky drinking in adolescents and the impact of neurobiological determinants on early alcohol-related cognitive deficits in young people. METHODS: Narrative review. RESULTS: There is consensus that the brain and the behaviour are shaped during development by the combined effects of genes, childhood experiences, environment and hormonal variations. Epigenetic factors seem to play a role in linking the expression of genes with stress and external experiences during brain maturation and development. Evidence on the interaction between genes and environmental factors illustrates that, in adolescence, external factors play a more important role than genetic factors on the risk of developing alcohol problems later on in life. CONCLUSIONS: Adolescence is a crucial stage of brain development; intervening early and applying certain prevention programmes may halt the progression of alcohol misuse.

Time to act on the inadequate management of Wernicke's encephalopathy in the UK.

Wernicke's encephalopathy (WE) is a serious medical emergency whose pathogenesis is well understood and reviewed in this paper. Summarizing the evidence for its prophylaxis and management, the authors suggest that, in the UK, there is evidence that many patients identified as being at risk of WE currently do not receive appropriate treatment, despite the availability (not universal) of guidelines and protocols.

A rare case of tuberculosis of the midfoot.

Despite the increasing prevalence of tuberculosis in developed countries, tuberculous osteomyelitis of the foot remains an uncommon complication. The relative rarity of such a diagnosis means that delays are often incurred before clinicians can correctly identify the pathogen and therefore instigate appropriate chemotherapy. The authors present a case of midfoot pain secondary to tuberculous osteomyelitis.

Case study: Epidermoid cyst following percutaneous Topaz coblation for plantar fasciitis.

An epidermoid cyst is formed when there is proliferation of epidermal cells within an area of the dermis. They may be formed by the traumatic implantation of epidermal cells within the dermis as well as many other mechanisms. We present a case of epidermoid cyst formation following Topaz coblation for plantar fasciitis; a complication we believe is yet to be reported in the literature.

The Korsakoff syndrome: clinical aspects, psychology and treatment.

AIMS: The Korsakoff syndrome is a preventable memory disorder that usually emerges (although not always) in the aftermath of an episode of Wernicke's encephalopathy. The present paper reviews the clinical and scientific literature on this disorder. METHODS: A systematic review of the clinical and scientific literature on Wernicke's encephalopathy and the alcoholic Korsakoff syndrome. RESULTS: The Korsakoff syndrome is most commonly associated with chronic alcohol misuse, and some heavy drinkers may have a genetic predisposition to developing the syndrome. The characteristic neuropathology includes neuronal loss, micro-haemorrhages and gliosis in the paraventricular and peri-aqueductal grey matter. Lesions in the mammillary bodies, the mammillo-thalamic tract and the anterior thalamus may be more important to memory dysfunction than lesions in the medial dorsal nucleus of the thalamus. Episodic memory is severely affected in the Korsakoff syndrome, and the learning of new semantic memories is variably affected. 'Implicit' aspects of memory are preserved. These patients are often first encountered in general hospital settings where they can occupy acute medical beds for lengthy periods. Abstinence is the cornerstone of any rehabilitation programme. Korsakoff patients are capable of new learning, particularly if they live in a calm and well-structured environment and if new information is cued. There are few long-term follow-up studies, but these patients are reported to have a normal life expectancy if they remain abstinent from alcohol. CONCLUSIONS: Although we now have substantial knowledge about the nature of this disorder, scientific questions (e.g. regarding the underlying genetics) remain. More particularly, there is a dearth of appropriate long-term care facilities for these patients, given that empirical research has shown that good practice has beneficial effects.