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1.
Toxins (Basel) ; 15(9)2023 Aug 28.
Article in English | MEDLINE | ID: mdl-37755956

ABSTRACT

The interactions between specific snake venom toxins and muscle constituents are the major cause of severe muscle damage that often result in amputations and subsequent socioeconomic ramifications for snakebite victims and/or their families. Therefore, improving our understanding of venom-induced muscle damage and determining the underlying mechanisms of muscle degeneration/regeneration following snakebites is critical to developing better strategies to tackle this issue. Here, we analysed intramuscular bleeding and thrombosis in muscle injuries induced by two different snake venom toxins (CAMP-Crotalus atrox metalloprotease (a PIII metalloprotease from the venom of this snake) and a three-finger toxin (CTX, a cardiotoxin from the venom of Naja pallida)). Classically, these toxins represent diverse scenarios characterised by persistent muscle damage (CAMP) and successful regeneration (CTX) following acute damage, as normally observed in envenomation by most vipers and some elapid snakes of Asian, Australasian, and African origin, respectively. Our immunohistochemical analysis confirmed that both CAMP and CTX induced extensive muscle destruction on day 5, although the effects of CTX were reversed over time. We identified the presence of fibrinogen and P-selectin exposure inside the damaged muscle sections, suggesting signs of bleeding and the formation of platelet aggregates/microthrombi in tissues, respectively. Intriguingly, CAMP causes integrin shedding but does not affect any blood clotting parameters, whereas CTX significantly extends the clotting time and has no impact on integrin shedding. The rates of fibrinogen clearance and reduction in microthrombi were greater in CTX-treated muscle compared to CAMP-treated muscle. Together, these findings reveal novel aspects of venom-induced muscle damage and highlight the relevance of haemostatic events such as bleeding and thrombosis for muscle regeneration and provide useful mechanistic insights for developing better therapeutic interventions.


Subject(s)
Crotalus , Snake Bites , Thrombosis , Venomous Snakes , Humans , Cardiotoxins/toxicity , Elapid Venoms/pharmacology , Snake Venoms/pharmacology , Hemorrhage/chemically induced , Metalloproteases/pharmacology , Fibrinogen , Muscle, Skeletal , Integrins , Snake Bites/complications
2.
Adv Healthc Mater ; 9(5): e1901521, 2020 03.
Article in English | MEDLINE | ID: mdl-31977153

ABSTRACT

Various injectable biomaterials are developed for the minimally invasive delivery of therapeutics. Typically, a mechanical tester is used to ascertain the force required to inject these biomaterials through a given syringe-needle system. However, currently there is no method to correlate the force measured in the laboratory to the perceived effort required to perform that injection by the end user. In this article, the injection force (F) for a variety of biomaterials, displaying a range of rheological properties, is compared with the effort scores from a 50 person panel study. The maximum injection force measured at crosshead speed 1 mm s-1 is a good proxy for injection effort, with an R2 of 0.89. This correlation leads to the following conclusions: participants can easily inject 5 mL of substance for F < 12 N; considerable effort is required to inject 5 mL for 12 N < F < 38 N; great effort is required and <5 mL can be injected for 38 N < F < 64 N; and materials are entirely non-injectable for F > 64 N. These values may be used by developers of injectable biomaterials to make decisions about formulations and needle sizes early in the translational process.


Subject(s)
Mechanical Phenomena , Needles , Humans , Injections , Rheology , Viscosity
3.
Article in English | MEDLINE | ID: mdl-28396652

ABSTRACT

AIM: Using routine hemoglobin A1c (HbA1c) testing to describe the prevalence, characteristics, and length of stay (LOS) of psychiatry inpatients with type 2 diabetes compared to those with pre-diabetes and those without diabetes. METHODS: In this prospective observational study, all inpatients aged greater than 30 years admitted to the Austin Health Psychiatry Unit, a major tertiary hospital, affiliated with the University of Melbourne, between February 2014 and April 2015 had routine HbA1c testing as part of the Diabetes Discovery Initiative. Patients were divided into three groups: diabetes (HbA1c ≥ 6.5%, 48 mmol/mol), pre-diabetes (HbA1c 5.7-6.4%, 39-46 mmol/mol), or no diabetes (HbA1c ≤ 5.6%, 38 mmol/mol). Baseline characteristics, co-morbidities, psychiatric illnesses, and treatment were recorded. RESULTS: There were a total of 335 psychiatry inpatients (median age 41 years). The most prevalent diagnoses were schizophrenia, depression, and substance abuse. Of the 335 psychiatric inpatients, 14% (n = 46) had diabetes and 19% (n = 63) had pre-diabetes, a prevalence threefold greater than in the aged matched general population. Compared to inpatients with pre-diabetes and no diabetes, those with diabetes were older and were at least twice as likely to have hypertension, obesity, and hyperlipidemia (all p ≤ 0.002). In multivariable analyses, diabetes was associated with increasing age (p = 0.02), substance abuse (p = 0.04), dyslipidaemia (p = 0.03), and aripiprazole use (p = 0.01). Patients with diabetes also had a 70% longer expected LOS (95% CI: 20-130%; p = 0.001), compared to those with pre-diabetes and no diabetes. CONCLUSION: Despite relative youth, one-third of all psychiatric inpatients above the age of 30 have diabetes or pre-diabetes. Presence of diabetes in psychiatric inpatients is associated with older age, substance abuse, and longer LOS. Routine inpatient HbA1c testing provides an opportunity for early detection and optimization of diabetes care.

4.
Burns ; 41(7): 1375-84, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26359733

ABSTRACT

INTRODUCTION: Burn care innovations have vastly reduced mortality rates and improved prognoses, fostering the need for multi-disciplinary input in holistic recovery. Consequently psychological and social considerations post-burn are included in National Burn Care Standards and have featured increasingly in burns literature. AIM: To identify the key findings of the rapidly expanding literature base for psychosocial adjustment post-burn, highlighting the most important knowledge and future directions for both practice and research. METHOD: MEDLINE, CINAHL, EMBASE, PsycINFO, BNI, HMIC databases were searched from January 2003 to September 2013 using search terms regarding psychosocial adjustment post-burn. After exclusions 24 papers underwent critical appraisal. RESULTS: Studies were categorised by the element of adjustment that they examined; psychopathology, quality of life, return to work, interpersonal, post-traumatic growth. Strengths, weaknesses, and significant findings within each category were presented. DISCUSSION: Although psychopathology and quality of life were well-researched compared to other categories, all would benefit from methodological improvements such as sample size or dropout rates. Coping strategies, premorbid psychopathology, and personality consistently featured as predictors of adjustment, although research should now move from identifying predictors, to clarifying the concept and parameters of psychosocial adjustment while developing and evaluating interventions to improve outcomes.


Subject(s)
Adaptation, Psychological , Burns/psychology , Humans , Mental Disorders/psychology , Personality , Quality of Life/psychology , Social Support , Stress Disorders, Post-Traumatic/psychology
5.
J Pain ; 15(3): 283-92, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24333399

ABSTRACT

UNLABELLED: Deep brain stimulation (DBS) of the periventricular/periaqueductal gray area and sensory thalamus can reduce pain intensity in patients with neuropathic pain. However, little is known about its impact on quality of life, emotional well-being, and cognition. This study followed up 18 patients who had received DBS for neuropathic pain. Each participant had previously undergone psychometric evaluation of each of the above areas as part of a routine presurgical neuropsychological assessment. Commensurate measures were employed at a follow-up assessment at least 6 months postsurgery. DBS significantly improved mood, anxiety, and aspects of quality of life. Improvements correlated with reduced pain severity. However, the sample continued to show impairments in most areas when compared against normative data published on nonclinical samples. There was little change in general cognitive functioning, aside from deterioration in spatial working memory. However, improvements in pain severity were associated with less improvement (and even deterioration) on measures of executive cognitive functioning. Improvements in emotional well-being also were correlated with changes in cognition. These results suggest that DBS of the periventricular/periaqueductal gray and/or sensory thalamus improves quality of life and emotional well-being in sufferers, although there is some indication of executive dysfunction, particularly among those reporting greatest pain alleviation. PERSPECTIVE: This article examines the neuropsychological outcomes of DBS surgery as a treatment for neuropathic pain. This intervention was found to improve pain severity, emotional well-being, and quality of life, although such benefits may be accompanied by reduced ability on tasks measuring executive functioning.


Subject(s)
Deep Brain Stimulation , Neuralgia/therapy , Adult , Affect/physiology , Anxiety/etiology , Anxiety/physiopathology , Anxiety/therapy , Cognition/physiology , Deep Brain Stimulation/adverse effects , Emotions/physiology , Executive Function/physiology , Female , Follow-Up Studies , Humans , Longitudinal Studies , Male , Memory Disorders/etiology , Memory Disorders/physiopathology , Memory, Short-Term/physiology , Middle Aged , Neuralgia/complications , Neuralgia/physiopathology , Neuralgia/psychology , Periaqueductal Gray/physiopathology , Periaqueductal Gray/surgery , Quality of Life , Severity of Illness Index , Space Perception/physiology , Treatment Outcome
6.
PLoS Genet ; 7(12): e1002374, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22144905

ABSTRACT

Sterol regulatory element binding proteins (SREBPs) are a class of basic helix-loop-helix transcription factors that regulate diverse cellular responses in eukaryotes. Adding to the recognized importance of SREBPs in human health, SREBPs in the human fungal pathogens Cryptococcus neoformans and Aspergillus fumigatus are required for fungal virulence and susceptibility to triazole antifungal drugs. To date, the exact mechanism(s) behind the role of SREBP in these observed phenotypes is not clear. Here, we report that A. fumigatus SREBP, SrbA, mediates regulation of iron acquisition in response to hypoxia and low iron conditions. To further define SrbA's role in iron acquisition in relation to previously studied fungal regulators of iron metabolism, SreA and HapX, a series of mutants were generated in the ΔsrbA background. These data suggest that SrbA is activated independently of SreA and HapX in response to iron limitation, but that HapX mRNA induction is partially dependent on SrbA. Intriguingly, exogenous addition of high iron or genetic deletion of sreA in the ΔsrbA background was able to partially rescue the hypoxia growth, triazole drug susceptibility, and decrease in ergosterol content phenotypes of ΔsrbA. Thus, we conclude that the fungal SREBP, SrbA, is critical for coordinating genes involved in iron acquisition and ergosterol biosynthesis under hypoxia and low iron conditions found at sites of human fungal infections. These results support a role for SREBP-mediated iron regulation in fungal virulence, and they lay a foundation for further exploration of SREBP's role in iron homeostasis in other eukaryotes.


Subject(s)
Antifungal Agents/pharmacology , Aspergillus fumigatus/drug effects , Ergosterol/metabolism , Iron/metabolism , Sterol Regulatory Element Binding Proteins/metabolism , Animals , Aspergillus fumigatus/pathogenicity , Drug Resistance, Fungal/genetics , Gene Expression Regulation, Fungal/genetics , Homeostasis , Humans , Lung Diseases, Fungal/drug therapy , Lung Diseases, Fungal/genetics , Mice , Oligonucleotide Array Sequence Analysis , Siderophores/metabolism , Sterol Regulatory Element Binding Proteins/genetics , Triazoles/pharmacology
7.
Mil Med ; 172(7): 726-30, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17691685

ABSTRACT

The purpose of this study was to describe the effects of blast exposure on hearing status. This study retrospectively analyzed hearing thresholds and otologic complaints for >250 patients with blast-related injuries from the global war on terror. Of patients who received full diagnostic evaluations, 32% reported a history of tympanic membrane perforation, 49% experienced tinnitus, 26% reported otalgia (ear pain), and 15% reported dizziness. Expected hearing thresholds were computed by applying age-correction factors to hearing tests performed earlier in the service members' careers and before their most recent deployment. Expected hearing thresholds were significantly better than actual postdeployment thresholds, indicating that significant changes occurred in the patients' hearing that could not be accounted for by age. Results from this study underline the need for documentation of pre-and postdeployment hearing tests and prompt otologic evaluation for the blast-exposed population.


Subject(s)
Blast Injuries/epidemiology , Ear Diseases/epidemiology , Ear/injuries , Global Health , Military Medicine , Military Personnel , Terrorism , Warfare , Adult , Audiometry , Female , Hearing Disorders/epidemiology , Humans , Male , Middle Aged , Prevalence , Retrospective Studies , United States/epidemiology
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