The Burundi Heart Centre: From concept to design.

Burundi is one of the worlds poorest nations, which is also reflected in its relative lack of cardiac facilities, particularly those catering to young children and adults. The authors discuss current efforts to build The Burundi Heart Centre to help address this challenge. In particular, they highlight how the project can act as a case study for a sustainable architecture that involves local people and uses locally available materials in a contemporary and innovative way

Pattern and degree of left ventricular remodeling following a tailored surgical approach for hypertrophic obstructive cardiomyopathy.

Background The role of a tailored surgical approach for hypertrophic cardiomyopathy (HCM) on regional ventricular remodelling remains unknown. The aims of this study were to evaluate the pattern, extent and functional impact of regional ventricular remodelling after a tailored surgical approach. Methods From 2005 to 2008, 44 patients with obstructive HCM underwent tailored surgical intervention. Of those, 14 were ineligible for cardiac magnetic resonance (CMR) studies. From the remainder, 14 unselected patients (42±12 years) underwent pre- and post-operative CMR studies at a median 12 months post-operatively (range 4-37 months). Regional changes in left ventricular (LV) thickness as well as global LV function following surgery were assessed using CMR Tools (London, UK). Results Pre-operative mean echocardiographic septal thickness was 21±4 mm and mean LV outflow gradient was 69±32 mmHg. Following surgery, there was a significant degree of regional regression of LV thickness in all segments of the LV, ranging from 16% in the antero-lateral midventricular segment to 41% in the anterior basal segment. Wall thickening was significantly increased in basal segments but showed no significant change in the midventricular or apical segments. Globally, mean indexed LV mass decreased significantly after surgery (120±29g/m2 versus 154±36g/m2; p<0.001). There was a trend for increased indexed LV end-diastolic volume (70±13 mL versus 65±11 mL; p=0.16) with a normalization of LV ejection fraction (68±7% versus 75±9%; p<0.01). Conclusion Following a tailored surgical relief of outflow obstruction for HCM, there is a marked regional reverse LV remodelling. These changes could have a significant impact on overall ventricular dynamics and function

Valve interstitial cells induce donor-specific T-cell anergy

AbstractObjectives: Valve allografts produce an immune response, which can influence their performance. The exact role of the interaction between recipient T cells and the different cellular components of the donor valve in stimulating an immune response is not known. Therefore the T-cell response to valve endothelial and interstitial cells was investigated in vitro. Methods: Valve endothelial and interstitial cells were characterized for cell-surface molecules before and after interferon γ treatment by means of a panel of specific monoclonal antibodies and flow cytometry. The proliferative response of highly purified T lymphocytes was used to assess the immunogenicity of cultured valve endothelial and interstitial cells. This was further investigated by using a 2-step tolerance-induction protocol. Results: Valve endothelial and interstitial cells express similar levels of human leukocyte antigens and adhesion and costimulatory molecules, which are either induced or upregulated after interferon γ treatment. T-cell responses to endothelial cells were detected after interferon γ treatment, but responses to interferon γ–treated interstitial cells were not detected. This lack of response resulted in the induction of T-cell anergy, which was reversed by the presence of the costimulatory molecule B7-1. Conclusions: Although valve endothelial and interstitial cells express a similar range of cell-surface molecules, it is only the endothelial cells that are immunogenic. In addition, we have shown that these 2 cell types interact in a donorspecific manner to orchestrate the immune response and therefore may have clinical relevance in the allogeneic response of the heart valve recipients.J Thorac Cardiovasc Surg 2001;122:129-3

Quantification and Comparison of Droplet Formation During Endoscopic and Microscopic Ear Surgery: A Cadaveric Model

Objectives: The COVID-19 pandemic and the disproportional spread of the disease among otorhinolaryngologists raised concerns regarding the safety of health care staff. Therefore, a quantitative risk assessment for otologic surgery would be desirable. This study aims to quantitatively compare the risk of perioperative droplet formation between microscopic and endoscopic approaches. Study Design: Experimental research. Setting: Temporal bone laboratory. Methods: The middle ear of whole head specimens was injected with fluorescein (0.2 mg/10 mL) before endoscopic and microscopic epitympanectomy and mastoidectomy. Fluorescent droplet deposition on the surgical table was recorded under ultraviolet light, quantified, and compared among the interventions. Drilling time, droplet proportion, fluorescein intensity, and droplet size were assessed for every procedure. Results: A total of 12 procedures were performed: 4 endoscopic epitympanectomies, 4 microscopic epitympanectomies, and 4 mastoidectomies. The mean (SD) proportion of fluorescein droplets was 0.14‰ (0.10‰) for endoscopic epitympanectomy and 0.64‰ (0.31‰) for microscopic epitympanectomy. During mastoidectomy, the deposition of droplets was 8.77‰ (6.71‰). Statistical comparison based on a mixed effects model revealed a significant increase (0.50‰) in droplet deposition during microscopic epitympanectomy as compared with endoscopic epitympanectomy (95% CI, 0.16‰ to 0.84‰). Conclusions: There is considerable droplet generation during otologic surgery, and this represents a risk for the spread of airborne infectious diseases. The endoscopic technique offers the lowest risk of droplet formation as compared with microscopic approaches, with a significant 4.5-fold reduction of droplets between endoscopic and microscopic epitympanectomy and a 62-fold reduction between endoscopic epitympanectomy and cortical mastoidectomy

Co-channel interference and background noise in κ - μ fading channels

In this letter, we derive novel analytical and closed form expressions for the outage probability, when the signal-of- interest (SoI) and the interferer experience kappa-mu fading in the presence of Gaussian noise. Most importantly, these expressions hold true for independent and non-identically distributed kappa-mu variates, without parameter constraints. We also find the asymptotic behaviour when the average signal to noise ratio of the SoI is significantly larger than that of the interferer. It is worth highlighting that our new solutions are very general owing to the flexibility of the kappa-mu fading model21512151218CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ304248/2014-2This work was supported by the U.K. Engineering and Physical Sciences Research Council under Grant Reference EP/L026074/1 and by CNPq under Grant Reference 304248/2014-2

Hyperacute hyponatremia mimicking acute ischemic stroke: A case report.

We present a case of hyperacute hyponatremia with stroke like symptoms on presentation. Symptoms included confusion, left-sided facial droop, right-sided hemiparesis, dysarthria and aphasia, with an NIH stroke score of 5. Sodium level at the time of presentation was 119 mmol/L which dropped acutely from 138 mmol/L seven hours prior. Symptoms improved after treatment with 3% saline and no evidence of stroke, intracranial hemorrhage or space-occupying lesion was seen on imaging. The most likely cause of the hyponatremia was increased free water consumption and ADH surge. The patient remained symptom free after discharge with resolution of hyponatremia. Acute hyponatremia can cause focal neurological complaints and deficits, mimicking acute ischemic stroke. We advise clinicians to be aware of this entity when considering interventions for possible acute ischemic stroke and evaluating a patient with focal neurological deficits

Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Determination of Temozolomide in Mouse Brain Tissue

Temozolomide is a Food and Drug Administration-approved anticancer drug that has poor drug delivery via oral or intravenous routes. A potential strategy to combat this problem is investigating alternative routes of administration, requiring quantitation of the drug in the brain tissues by liquid chromatography-mass spectrometry. However, current methods used to extract the drug from brain tissues resulted in poor recovery and substantial matrix effects. Herein, we reported a new two-step extraction method that involves the use of Proteinase K to lyse tumor tissues to efficiently release the drug, followed by ethanol protein precipitation. The extracts were then separated on a C18 column and analyzed in positive electrospray ionization, a multiple reaction monitoring mode of the triple quadrupole. We found this new method led to a recovery of 82% with negligible matrix effects. The method has been validated in accordance with Food and Drug Administration guidance for linearity, specificity, selectivity, accuracy, precision, carry-over, stability, and lower limit of quantitation. In conclusion, we have developed and validated a liquid chromatography-mass spectrometry method with a novel sample preparation method that was able to efficiently extract temozolomide from mouse brain tissue with high recovery