Scimitar syndrome

A female child of age five attended our institution in Jan 2006 with repeated upper respiratory infection. Plain skiagram and CT examinations confirmed the case to be a Scimitar syndrome. DOI: http://dx.doi.org/10.3329/bjms.v14i1.21576 Bangladesh Journal of Medical Science Vol.14(1) 2015 p.103-105

Cystic Meningioma

Meningiomas are most common intracranial extraaxial tumours, but atypical meningeiomas like cystic meningioma are rare. It is about 2 to 4 % in adults and 10 to 19 % in infants. Because of its atypical presentation a case of cystic meningioma is presented. DOI: http://dx.doi.org/10.3329/bjms.v12i1.11542 Bangladesh Journal of Medical Science Vol. 12 No. 01 January’13 pp.83-85

Calculi In A Female Urethral: A Rare Cause of Acute Urinary Retention

Urinary calculi are rarely seen in the urethra and are usually encountered in men with urethral stricture or diverticulum. The case of a 23-year-old woman presented with acute retention of urine associated with recurrent urinary tract infection.  Cystoscopy was done and the stone was removed. The patient has been well, with no dysuria, and in­continence for 3-month follow-ups.DOI: http://dx.doi.org/10.3329/bjms.v11i2.8724 Bangladesh Journal of Medical Science Vol. 11 No. 02 April 2012: 137-138 

Metal contacts in nanocrystalline n-type GaN: Schottky diodes

Contact properties in nanocrystalline n-GaN in thin film form were studied by depositing nanocrystalline films onto aluminium coated fused silica substrates by high pressure sputtering of Si (1 at%) doped GaN target. Schottky diodes were realized with Au, Ni and Pd as top contacts on the nanocrystalline n-GaN films to examine the contact properties of the diodes thus formed. Variation of current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the Schottky diodes were recorded at different temperatures and analyzed in the light of the existing theories.

Studies of self-organized nanostructures on InP(111) surfaces after low energy Ar+ ion irradiation

We report formation of self organized InP nano dots using 3 keV Ar+ ion sputtering, at 15 degrees incidence from surface normal, on InP(111) surface. Morphology and optical properties of the sputtered surface, as a function of sputtering time, have been investigated by Scanning Probe Microscopy and Raman Scattering techniques. Uniform patterns of nano dots are observed for different durations of sputtering. The sizes and the heights of these nano dots vary between 10 to 100 nm and 20 to 40 nm, respectively. With increasing of sputtering time, t, the size and height of these nano dots increases up to a certain sputtering time t(c). However beyond t(c), the dots break down into smaller nanostructures, and as a result, the size and height of these nanostructures decrease. The uniformity and regularity of these structures are also lost for sputtering beyond t(c). The crossover behavior is also observed in the rms surface roughness. Raman investigations of InP nano dots reveal optical phonon softening due to phonon confinement in the surface nano dots.

XPS studies of DNA-cation-interacted self-assembled HgTe quantum dots formed under electrodeposition and their resultant biomolecular recognition application

DNA interactions with multivalent cations, leading to wrapping around the cations and thermodynamically stable structure formation, followed by electrodeposition, have yielded a narrow size distributed single-crystalline HgTe-DNA quantum dot (QD) hybrid system. The mechanisms of the DNA interactions resulting in self-assembled HgTe QDs through phosphate-cation linkages and superstructure formation by nitrogen base interactions have been established by their respective binding energy shifts as evidenced from x-ray photoelectron spectroscopic studies. The photoluminescence peak position associated with HgTe QD single stranded DNA is red shifted in the presence of its conjugate and suggests the system as a potential optical probe for biomolecular recognition applications.

Biomolecular recognition in DNA tagged CdSe nanowires

DNA template driven CdSe nanobeads (NBs) and nanowires (NWs) have been synthesized by an electrodeposition technique. The synthesis protocol has yielded randomly oriented cubic CdSe NBs with mean size approximately 3.0 nm in presence of single stranded DNA, poly G(30). Monocrystalline cubic CdSe NWs of width approximately 4.0 nm with string-like morphology have been achieved when synthesized in presence of both poly G(30) and its conjugate, poly C(30). Optical absorption of CdSe NBs show a blue shift of 0.8 eV and long wavelength tailing where as NWs show steep increase of absorption in shorter wavelength regime accompanied by a further blue shift. DNA tags to the NBs or NWs have been confirmed from Fourier transform infrared spectroscopy measurements. Biomolecular recognition with CdSe NWs have been established by photoluminescence measurements.

Combined effect of adenosine 3',5'-cyclic monophosphate stimulating agents, vitamin E succinate, and heat on the survival of murine B-16 melanoma cells in culture

An elevation of the intracellular level of cAMP by 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (R020-1724) during heat treatment (41 degrees C for 10 hours) markedly reduced the survival of murine B-16 melanoma cells in culture; however, heat alone or R020-1724 treatment at 37 degrees C for 10 hours was ineffective. D-alpha-tocopheryl succinate (vitamin E succinate), which did not increase cAMP level, reduced the survival of heated cells to a greater degree than with vitamin E succinate alone. The presence of vitamin E succinate for the entire experimental period (during heat and observation period) was necessary for this effect. R020-1724 in combination with vitamin E succinate was more effective in reducing the survival of heated cells than the individual agents. Although prostaglandin (PG) A2 did not increase cAMP level in melanoma cells, it decreased the survival of heated cells when present during heat treatment. Other forms of PG such as PGE1 and PGF2 alpha were ineffective. The combination of R020-1724 with two non-cAMP stimulating agents, PGA2 and vitamin E succinate, decreased the survival of heated cells by about 94% of control. These results suggest that the heat sensitivity of melanoma cells can be increased by cAMP-dependent and -independent mechanisms.

Effect of alpha tocopheryl succinate on adenylate cyclase activity in murine neuroblastoma cells in culture

Alpha tocopheryl succinate treatment (6-8 micrograms/ml), which inhibited the growth of murine neuroblastoma (NBP2) cells (46 +/- 3%), reduced basal and prostaglandin (PG)E1- and PGA2-stimulated adenylate cyclase (AC) activity in vitro. It also inhibited sodium fluoride (NaF)- and forskolin-stimulated AC activity, suggesting that the effect of vitamin E succinate on AC activity is mediated via stimulatory GTP-binding protein (Gs) and catalytic subunit. Vitamin E succinate-induced reduction of AC activity is not strictly related to inhibition of cell growth. This is substantiated by the finding that, although retinoic acid and butylated hydroxyanisole reduced the growth by over 50%, they did not inhibit AC activity. On the other hand, 4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (R020-1724, 200 micrograms/ml), which inhibited growth (73 +/- 3%) and induced differentiation in NB cells, increased basal and PGE1-stimulated AC activity. Vitamin E succinate treatment also reduced PGE1- and PGA2-AC activity in murine fibroblasts (L-cells) without inhibiting growth.

Alpha tocopheryl succinate inhibits melanocyte-stimulating hormone (MSH)-sensitive adenylate cyclase activity in melanoma cells

D-alpha tocopheryl succinate (vitamin E succinate), which is known to induce differentiation and growth inhibition in murine B-16 melanoma cells, reduced basal and melanocyte-stimulating hormone (MSH)-stimulated adenylate cyclase (AC) activity in vitro. Vitamin E succinate treatment also reduced sodium fluoride- and forskoline-stimulated AC activity of melanoma cells in vitro. Treatment of cells with vitamin E succinate (6 micrograms/ml] for a period of 24 hours was sufficient to reduce MSH-stimulated AC activity. Other forms of vitamin E, such as d1-alpha tocopheryl nicotinate, d1-alpha tocopheryl acetate, and d1-alpha tocopherol, which did not affect growth or morphology of melanoma cells, were relatively less effective in altering basal and MSH-stimulated AC activity. Retinoic acid, which inhibited the growth of B-16 melanoma cells, also reduced basal and MSH-, NaF-, and forskolin-stimulated AC activity in vitro. Prostaglandin A2, which inhibited growth and altered morphology, did not change basal or MSH-stimulated AC activity. These results show that one of the mechanisms of action of vitamin E succinate and retinoic acid on melanoma cells may involve reduction of basal and MSH-sensitive AC activity, and this vitamin effect is not necessarily related to growth inhibition.