Anatomical definition of aortic root abscesses by transesophageal echocardiography: Planning a surgical strategy using homograft valves

Infective endocarditis of the native or a prosthetic aortic valve may be complicated by abscess cavity development in the aortic root, and successful treatment depends upon early diagnosis, clear anatomical definition preoperatively, and maintaining sterility of the second implant. Homograft valves offer many advantages in this setting. Timing of surgery and the choice of the particular technique depends on accurate characterization of the anatomical details of the abscess. Five cases of paravalvular aortic root abscess in the setting of prosthetic valve endocarditis are described. In each case the diagnosis was made with transesophageal echocardiography, and the information was used in planning the operative procedure of homograft valve replacement. This strategy is proposed as optimal management of this potentially lethal condition.     

Antagonism of leukotriene receptors and administration of a 5-lipoxygenase inhibitor do not affect hypoxic vasoconstriction

The role of leukotrienes in hypoxic vasoconstriction remains controversial. Our previous study using the lipoxygenase inhibitor BW 755C in dogs failed to show a substantive role for leukotrienes in hypoxic vasoconstriction. To clarify further the role of leukotrienes, we designed 3 protocols. In the first protocol, we examined the effects of LTD₄ boluses on the pulmonary circulation in 6 anesthetized dogs. LTD₄, 1 μg/kg, (a large dose relative to other species) produced no detectable constriction of the pulmonary artery, while systemic vascular resistance increased 41±17% (SD), left atrial pressure rose 3.5±1.5 mmHg, and cardiac output fell 18±8%. Two leukotriene receptor antagonists, LY171883 and L-648051, decreased these effects by more than 50%. In the second protocol, we tested these antagonists in 7 anesthetized, paralyzed, closed-chest dogs with acute left lower lobe atelectasis. Two manifestations of hypoxic vasoconstriction were examined: shunt fraction (as an inverse indicator of regional constriction in response to local hypoxia) and the pulmonary pressor response to global alveolar hypoxia (as an index of general hypoxic vasoconstriction). During normoxia before administration of the inhibitor, shunt fraction, measured using an SF₆ infusion, was 25±7%. The pulmonary pressor response to hypoxia, defined as the increase in pulmonary end-diastolic gradient (PDG) produced by 10% O₂ inhalation, averaged +10.5±3.6 mmHg. The increase in pulmonary vascular resistance (PVR) with hypoxia was +2.4±1.7 mmHg/L/min. Then, during normoxia, 1 of the 2 antagonists was administered. Shunt fraction was unchanged (26±4%; p=0.5). The pressor response to hypoxia was slightly less but remained substantial (the increase in PDG with hypoxia was +7.9±2.8 mmHg; p<0.05; the increase in PVR was +1.8±1.2 mmHg/L/min, p<0.10). In the third protocol we gave RG 5901, a relatively specific 5-lipoxygenase inhibitor, to 5 dogs with lobar atelectasis. The indices of hypoxic vasoconstriction were not affected by RG 5901. Shunt fraction was 29.5±8.1% before and 27.0±7.4% after RG 5901 (p>0.05). The pressor response to hypoxia was + 8.9±2.1 mmHg before and +8.7±3.7 mmHg after RG 5901 (p>0.05). We conclude that in dogs, hypoxic vasoconstriction does not appear to be mediated by leukotrienes.     

Mucilage-capped silver nanoparticles for glucose electrochemical sensing and fuel cell applications

A simple, cost-effective and green mucilage-capped silver nanoparticles (Mucilage-AgNPs) modified glassy carbon electrode (GC) composite was constructed for efficient and facile electrochemical oxidation of glucose for the first time. Mucilage-AgNPs were synthesized through the direct chemical reduction of Ag⁺ by mucilage extracted from Opuntia ficus-indica. Mucilage-AgNPs were identified and characterized using ultraviolet-visible spectroscopy, transmission electron microscopy and square wave voltammetry. Modification of the GC with AgNPs was carried out via a transfer-sticking technique with an immobilization time of 1 h. The Mucilage-AgNPs/GC composite was studied as a possible anode for glucose oxidation in a biofuel cell. The composite resulted in glucose oxidation with a current density and power density of 85.7 μA cm⁻² and 25.7 μW cm⁻², respectively. Glucose sensing using the Mucilage-AgNPs/GC composite was achieved successfully via two pathways: glucose oxidation and AgNP inhibition. The glucose oxidation-based sensor showed a lower detection limit of 0.01 mM and a linear range of 0.01 to 2.2 mM. The AgNPs inhibition-based sensor provides an indirect determination pathway of glucose with a detection limit of 0.1 mM and a linear range of 0.1 to 1.9 mM. AgNP inhibition is a novel pathway that could be used for determining a large number of organic and inorganic molecules. Overall, the Mucilage-AgNPs/GC is considered a pioneering composite for glucose sensing and fuel cell applications.

A simple, cost-effective and green mucilage-capped silver nanoparticles (Mucilage-AgNPs) modified glassy carbon electrode (GC) composite was constructed for efficient and facile electrochemical oxidation of glucose for the first time.     

Visceral basidiobolomycosis: An overlooked infection in immunocompetent children

Visceral basidiobolomycosis is an unusual fungal infection of viscera caused by saprophyte Basidiobolus ranarum. It is very rare in healthy children and poses a diagnostic challenge due to the non-specific clinical presentation and the absence of predisposing factors. We report a case of gastrointestinal basidiobolomycosis in a 4-year-old healthy girl who presented with a short history of abdominal pain, bleeding per rectum, fever, and weight loss. The diagnosis was based on high eosinophilic count, classical histopathology findings of fungal hyphae (the Splendore-Hoeppli phenomenon), and positive fungal culture from a tissue biopsy. Fungal infection was successfully eradicated with a combined approach of surgical resection of the infected tissue and a well-monitored course of antifungal therapy. The atypical clinical presentation, diagnostic techniques, and the role of surgery in the management of a rare and lethal fungal disease in an immunocompetent child are discussed.Key words: Basidiobolomycosis, child, fungal infection, gastrointestinal, immunocompetent     

Mixed gynecomastia

Gynecomastia is an enlargement of male breast resulting from a proliferation of its glandular component, and it is usually due to an altered estrogen-androgen balance. It should be differentiated from pseudogynecomastia, which is characterized by fat deposition without glandular proliferation and from breast carcinoma. Gynecomastia could be physiological in neonates and pubertal or pathological due to drug intake, chronic liver, or renal disease, hyperthyroidism, testicular or adrenal neoplasms, and hypogonadism whether primary, or secondary. Properly organized work-up is needed to reach the cause of gynecomastia. Here, we reported a case of a young Omani man with gynecomastia with the aim of creating awareness of the occurrence of Klinefelter’s syndrome (KS) in patients with gynecomastia, to observe any differences in clinical presentation of KS from those reported in the literature, and highlight the needed diagnostic work-up and treatment.Gynecomastia is an enlargement of male breast resulting from a proliferation of its glandular component. It is usually benign, bilateral, and characterized by the presence of a rubbery or firm mass around the nipples. It usually results from either increased estrogen level, increased breast sensitivity to estrogen,1 or low testosterone level. The highest incidence of gynecomastia is reported during neonatal period, puberty, and aging due to physiological disturbances. Pseudogynecomastia, which is often seen in obese men, refers to fat deposition without glandular proliferation and should be differentiated from gynecomastia. Therefore, male breast enlargement can be fatty (pseudogynecomastia or lipomastia), pure gynecomastia, or mixed. Our objective in presenting this particular case is to create awareness of the occurrence of Klinefelter’s syndrome (KS) in patients with gynecomastia, to observe any differences in clinical presentation of KS from those reported in the literature, and highlight the needed diagnostic work-up and treatment.     

Gender impact on prognosis of acute coronary syndrome patients treated with drug-eluting stents

Women have a higher risk of adverse outcomes after percutaneous coronary intervention (PCI) than men. However, in acute coronary syndrome (ACS), long-term outcomes after contemporary PCI with drug-eluting stent (DES) have not been fully investigated. We aimed to test the impact of gender on outcomes in patients with ACS after PCI with DES. We analyzed all patients with ACS from the prospective NOBORI-2 trial who underwent PCI with a Nobori DES from 2008 through 2009 in 125 centers worldwide. End points of the study were target lesion failure, cardiac death, myocardial infarction (MI), and clinically driven target lesion revascularization, and major adverse cardiac events (composite of cardiac death, MI, and target vessel revascularization) at 1 year and yearly up to 5 years. There were 1,640 patients with ACS, 1,268 men (77%) and 372 women (23%). Compared to men, women were 5 years older and more frequently had co-morbidities such as diabetes mellitus and hypertension. There were no gender differences for cardiac death (1.3% vs 2.7%), MI (2.1% vs 3.2%), or target lesion revascularization (2.6% vs 3.8%) at 1 year after the procedure for men and women, respectively. The trend was the same at 2 years (cardiac death 2.0% vs 2.3%, MI 2.5% vs 3.5%, target lesion revascularization 3.2% vs 4.6%). Target lesion failure rates were 4.5% and 5.9% at 1 year and 5.7% and 7.3% at 2 years in men and women, respectively (p = NS). Multivariate analysis, which included age, hypertension, diabetes mellitus, and number of diseased vessels, showed that gender was not a predictor for outcome. There were no differences in bleeding or stent thrombosis rates. Relief from anginal symptoms was similar. The same rate of adherence to dual antiplatelet therapy was observed and reached 73% at 1 year and 31% at 2 years after the ACS event and PCI. In conclusion, although women had worse baseline characteristics, no differences in outcomes were observed between men and women treated for ACS with contemporary DES.     

Can Bridge to Recovery Help to Reveal the Secrets of the Failing Heart?

Despite several decades of research and clinical experience, the basic mechanisms of the failing heart remain largely a secret. While pharmacological therapy can induce limited reverse remodeling, left ventricular assist device (LVAD) therapy offers the opportunity to induce significant improvements to the structure and function of the heart, with major clinical implications. LVAD therapy also provides significant insight into which changes have an impact on function and which do not, and could therefore reveal some of the secrets of the failing heart. In addition, LVAD-induced mechanical unloading may unlock further myocardial properties hitherto unknown such as the proliferation of the stem cell compartment. It may also serve as an important platform for emerging therapies such as gene and cell therapies. In this review, we highlight the most recent novel discoveries related to LVAD therapy and bridge to recovery (BTR). Discovering the integrated network of events that underlies BTR could unravel the secrets of the failing heart.     

Irrigation endoscopic discectomy: a novel percutaneous approach for lumbar disc prolapse

Purpose

The purpose of this study is to present a new endoscopic procedure, aiming to achieve the success rate equivalent to microsurgical discectomy, while addressing the drawbacks and limitations of other percutaneous techniques.

Methods

A series of 43 patients with uncontained lumbar disc herniation underwent surgery with irrigation endoscopic discectomy (IED). The endoscope and instruments are placed directly over the surface of the lamina through two posterior skin portals 5 mm each without any muscle retraction or dilatation. Pump irrigation is used for the opening of a potential working space. The rest of the procedure is performed endoscopically like the standard microsurgical discectomy.

Results

Outcome according to modified Macnab criteria was excellent in 78 %, good in 17 %, and poor in 5 % of patients. VAS for leg pain dropped from 78 preoperatively to 7, and the Oswestry Low-Back Pain Disability Questionnaire dropped from 76 to 19. The mean time for postoperative ambulation was 4 h, hospital stay was 8 h, and for return to work was 7 days.

Conclusions

Preliminary clinical experience with IED shows it to be as effective as microsurgical discectomy, and in comparison to other percutaneous procedures addressing noncontained herniations, a reduction in the cost, technical difficulty and surgical invasiveness has been demonstrated.