Density functional theory based screening of ternary alkali-transition metal borohydrides: a computational material design project.

We present a computational screening study of ternary metal borohydrides for reversible hydrogen storage based on density functional theory. We investigate the stability and decomposition of alloys containing 1 alkali metal atom, Li, Na, or K (M(1)); and 1 alkali, alkaline earth or 3d/4d transition metal atom (M(2)) plus two to five (BH(4))(-) groups, i.e., M(1)M(2)(BH(4))(2-5), using a number of model structures with trigonal, tetrahedral, octahedral, and free coordination of the metal borohydride complexes. Of the over 700 investigated structures, about 20 were predicted to form potentially stable alloys with promising decomposition energies. The M(1)(Al/Mn/Fe)(BH(4))(4), (Li/Na)Zn(BH(4))(3), and (Na/K)(Ni/Co)(BH(4))(3) alloys are found to be the most promising, followed by selected M(1)(Nb/Rh)(BH(4))(4) alloys.

A unique case of Bezold's abscess associated with multiple dural sinus thromboses.

OBJECTIVES/HYPOTHESIS: Bezold's abscess and dural sinus thromboses are rare complications of otitis media in the era of antibiotics. Although potentially fatal, they are treatable. We present a unique case report of Bezold's abscess in association with multiple dural sinus thromboses. STUDY DESIGN: Single case report. METHODS: A young female patient's clinical course is presented and discussed. We review the anatomy, incidence, pathogenesis, and treatment of Bezold's abscess and dural sinus thrombosis. RESULTS: After mastoidectomy, neck exploration, broad-spectrum intravenous antibiotics, and anticoagulation therapy, the patient recovered fully and has remained asymptomatic since her discharge from the hospital at 12 months' follow-up. CONCLUSIONS: This is the first reported case of Bezold's abscess associated with a cavernous sinus thrombosis and the third reported case of Bezold's abscess associated with lateral sinus thrombosis. Despite its rarity, Bezold's abscess must be recognized and treated aggressively. Dural sinus thrombosis is relatively more common, and treatment of the underlying cause is essential. The diagnosis and rapid, aggressive treatment of these conditions are essential for an optimal clinical outcome.

A case of mycosis fungoides after CD30 positive anaplastic large cell lymphoma.

A 55-year-old woman presented with mycosis fungoides (MF) after the total excision of primary cutaneous CD30+ anaplastic large cell lymphoma (ALCL). In the specimens obtained from the nodule of CD30+ ALCL and the plaque lesion of MF, the same pattern of T-cell receptor gene rearragement was detected.

Tinea pedis in Korean children.

BACKGROUND: Tinea pedis is an infrequent disease in children before the age of puberty. There are few epidemiologic and clinical data regarding cases of tinea pedis observed in children. Materials and methods We prospectively collected all cases of tinea pedis in children diagnosed during the years 1995-1997. Only those showing a positive result with potassium hydroxide preparation were included in the study. We performed fungal cultures in Sabouraud's agar in all cases to document the etiologic fungi. The clinical characteristics were investigated. RESULTS: A total of 21 children, aged 3 months to 14 years, were included. Fifteen patients were boys and six were girls. The mean age was 7.1 years. All the children were otherwise healthy. Prior to the establishment of the diagnosis of tinea pedis, 17 patients (80.9%) were treated for eczema without improvement. The intertriginous type was most common (53.3%). The first or second toe-webs were the sites of predilection (32.3%). Eighteen children (86%) had a family history of tinea pedis and more than half of cases (52.4%) showed occurrence in the summer. The results of fungal cultures were positive in 13 patients (57%). Trichophyton rubrum was the most commonly isolated pathogen (69.2%). The other associated dermatoses were onychomycosis (33.3%), atopic dermatitis (14%), plantar warts (10%), and chronic urticaria (5%). Tinea pedis and onychomycosis cleared after treatment with topical antifungals with or without systemic antifungals in all cases. CONCLUSIONS: Tinea pedis in children can occur more frequently than suspected. Our study shows the strong association with a family history and the seasonal relationship with occurrence in summer in more than half of cases. We suggest that tinea pedis should be considered in the differential diagnosis of foot dermatitis in children.

Neurotrophins can enhance spiral ganglion cell survival after inner hair cell loss.

Following destruction of sensory cells of the organ of Corti, spiral ganglion cells (SGC) in the guinea pig degenerate. Chronic electrical stimulation via cochlear prostheses can enhance their survival, with the effect blocked by stopping the electrically elicited action potentials with tetrodotoxin. Blocking action potentials in the normal hearing ear with tetrodotoxin, however, does not cause degeneration. This suggests that in the pathological ear VIII N activity acts as a survival factor, while in the normal ear there are other survival factors that maintain SGCs. We examined neurotrophins, as survival factors in the deafened ear. Two weeks of treatment with BDNF (brain derived neurotrophic factor) administered chronically via a mini-osmotic pump into scala tympani at 50 ng/ml, provided a statistically significant enhanced SGC survival over untreated deafened ears or deafened ears treated with artificial perilymph. Neurotrophin 3 provided some enhanced survival, but this was not statistically significant over untreated deafened ears. These observations suggest there are survival factors in the inner ear, including those coupled to direct activation of the auditory nerve fibers, that may serve to maintain the auditory nerve. These factors may be applied following deafness to maintain and enhance neural populations and to increase benefits to the profoundly deaf receiving cochlear implants.

Intracellular calcium stores and oscillatory contractions in arteries from genetically hypertensive rats.

Strips of tail artery from stroke-prone spontaneously hypertensive rats (SHRSP), but not from normotensive Wistar Kyoto (WKY) rats, exhibit oscillatory activity after stimulation with norepinephrine. In addition, oscillatory activity is observed in response to tetraethylammonium (TEA) in vessels from both SHRSP and WKY rats. Mechanistically, the oscillatory contractions are associated with calcium (Ca2+)-driven action potentials. We have tested the hypothesis that intracellular Ca2+ stores participate in the generation of norepinephrine-induced oscillatory contractions in tail arteries from SHRSP. Additionally, the role of intracellular Ca2+ stores on TEA-induced contractions were evaluated. Contractile force in strips of tail artery from SHRSP and WKY rats was measured, using standard muscle bath procedures, and the effect of interventions that affect the storage of intracellular Ca2+ on the oscillatory contractions was evaluated. Depletion of intracellular Ca2+ stores, with ryanodine, or inhibition of Ca2+ uptake into the sarcoplasmic reticulum (SR), with thapsigargin and cyclopiazonic acid (CPA), did not inhibit oscillatory contractions induced by norepinephrine in SHRSP vessels. However, these agents inhibited the amplitude of TEA-induced contractions in WKY strips. Bay K 8644 and A23187 inhibited TEA-induced oscillatory contractions in WKY vessels. In SHRSP tail artery Bay K 8644 inhibited both norepinephrine and TEA-induced contractions, while A23187 did not have any effect. The phospholipase C inhibitor, NCDC (3X 10(-5) M), blocked oscillatory activity induced by norepinephrine in SHRSP tail artery and TEA-induced oscillations both in SHRSP and WKY vessels. These observations suggest that Ca2+ release and Ca2+ uptake into intracellular Ca2+ stores are not involved in the contraction-relaxation cycles that characterize norepinephrine-induced oscillatory activity in SHRSP tail artery. Similarly, SR Ca2+ stores may modulate but are not essential for TEA-induced oscillatory contractions.