Masson's Hemangioma of the Cheek: A Case Report.

We report a rare case of intravascular papillary endothelial hyperplasia (IPEH) of the cheek. This neoplasm, known as Masson's tumor, is an unusual vascular lesion of proliferating endothelial cells. It is usually confined to the lumen of preexisting vessels or vascular malformations. The principal significance of IPEH is its resemblance to a variety of benign and malignant diseases and possible misdiagnosis as such. Achieving a correct diagnosis is essential to avoid subjecting a patient to either unnecessarily aggressive or inadequate therapy. For this reason, awareness of this lesion is very important.

The impact of hearing loss in older adults: a tertiary care hospital based study.

Hearing loss is the most common sensory deficit in the elderly, and is becoming a severe social and health problem. Presbycusis is the result of aging which can lead to communication problems compromising the quality of life (QoL).Since the elderly population is increasing worldwide, presbycusis is showing a similar trend. This study intended to identify the impact of hearing loss in the social life of the elderly. A total of 70 elderly patients attending Nepal Medical College Teaching Hospital who were found to have sensorineural hearing loss (SNHL) on pure tone audiometry (PTA) were recruited for this study.None of the patients had used hearing aids in the past. To assess their handicap due to hearing impairment a Hearing Handicap Inventory for the Elderly (HHIE) questionnaire was used and patients were graded as: no handicap, mild to moderate handicap and significant handicap. Pure-tone averages (PTA) were calculated for the thresholds at 0.5, 1 and 2 kHz in each ear. Patients with their PTA values between 26 to 40 dBHL were interpreted as having mild SNHL, those between 41 to 55dBHL as moderate SNHL and those above 55 dBHL as severe SNHL. Out of 70 patients, 65 had some degree of handicap ranging from mild to severe. The severity of handicap was significantly associated with the degree of hearing loss in both ears.

Pattern of head and neck malignancies in eastern part of Nepal.

The term head and neck refers to the upper aerodigestive tract, the salivary glands, the thyroid, parathyroid glands, the sino-nasal tract and the skin of the head and neck region. Malignancies at these sites are important due to the divergence in their behaviors and prognosis. A retrospective, cross sectional, series of cases were studied to determine the pattern of head and neck malignancies in our department from January, 2005 to July, 2006. A total of 90 cases of head and neck malignancies proven on histopathology were studied. Pharynx 25 (27.78%) was the commonest site involved by cancer. In the pharynx, malignancies at the nasopharyngeal region contributed to the bulk of the tumor constituting 12 (48.00%). Histopathologically, squamous cell carcinoma was seen in 61, (67.77%) subjects. Most of the patients presented in IIIrd or IVth stage of disease. The commonest treatment strategy adopted was surgery with post operative radiotherapy. Nasopharyngeal carcinoma is a major concern in this part of the region.

Ear diseases in children presenting at Nepal Medical College Teaching Hospital.

Ear diseases are a common presentation in the ENT out-patient department. These diseases can have sequelae if not treated early which may cause increased morbidity, hearing disability and even mortality. Identifying these conditions early and treating them can reduce these unwanted sequelae. A prospective study over a period of three years was undertaken in a tertiary care hospital in Kathmandu. All children presenting with ear diseases consecutively in the ENT out-patients were included and their data was recorded in a pro forma. The data was analysed for frequency and cross-tabulated. The study included 2218 children with ear diseases among which 868 (39.1%) were pre-school and 1350 (60.9%) were school going children. The male to female ratio was 1.5:1. The most common otological problem was wax impaction (40.2%), followed by acute otitis media (AOM) with 24.3%, chronic suppurative otitis media (CSOM) with 17.7% and acute otitis externa (AOE) with 7.5% of the total cases. The other conditions were otitis media with effusion (2.8%), foreign bodies in the ear (2.3%), otomycosis (1.7%), preauricular sinus (1.1%), sensorineural hearing loss (0.8%), trauma to the ear (0.7%), keloids (0.3%), microtia (0.2%) and perichondritis (0.2%).The three year olds had the highest number of otological diseases with 9.2% of the total among the ages studied. It is felt that proper education of health care providers regarding ear diseases and also awareness in the community can prevent and reduce the disability and complications of these conditions.

Removal of coin from upper esophageal tract in children with Magill's forceps under propofol sedation.

Foreign body ingestion is a common emergency problem in children. Coins are the most common foreign bodies lodged in the esophagus. This is a retrospective study where we reviewed 21 consecutive paediatric cases of coins impacted in the upper esophagus. These children were attended at the BP Koirala Institute of Health Sciences, Dharan, from March 2007 to March 2008. In this study, Mc-Intosh laryngoscopes were inserted into the pharynx to elevate the larynx and to expose the esophageal entrance. Then Magill's forceps were advanced into the esophagus and opened in order to see and extract the coin from the esophagus under propofol sedation. Coins were successfully removed by Magill forceps without any complications from all 21 children. Amongst these children, 14 (66.7%) were male and 7 (33.3%) were female. The mean age of the children was 3.79 (+/- 3.02) years. The coin was grasped and extracted on the first attempt in all 21 patients. The mean time for the removal of the coin (i.e. initiation of laryngoscope to removal of coin) was 51.48 (+/- 24.17) seconds. During direct laryngoscopy, 15 (71.4%) coins were visualized clearly, whereas 6 (28.6%) were not. However all coins were successfully removed. The most commonly ingested coin is a one rupee Nepali coin (42.9%) followed by a two rupee coin (19.0%) and an Indian one rupee coin. Thus it can be seen that the coin impacted at the cricopharynx and upper oesophagus can be safely, easily and quickly removed by direct laryngoscopy and Magill's forceps under propofol sedation.

Penetrating neck injury by an arrow: a paradigm of age old assault.

Penetrating neck injuries by traditional weapons are rare entity in the modern era of sophisticated weapons. We report an unusual case of penetrating neck injury by a metallic arrow entering anterior neck in zone II and its tip coming out of neck posteriorly causing difficulty for patient to lie down as well as posing challenge to intubate. Arrows are low velocity projectile and from a close proximity they can cause penetrating trauma similar to a low powered handgun. Management of the case was discussed.

Primary salivary gland tumors in eastern Nepal tertiary care hospital.

BACKGROUND: The knowledge of the distribution and pattern of salivary gland tumors in the tertiary care center can provide overview of the disease pattern in the region. It also helps in planning the strategies to treat the disease and launch the awareness program in the community to this largely curable disease. METHODS: A retrospective observational study of all the salivary gland tumors treated in the department of Otolaryngology, B. P. Koirala Institute of Health Sciences during April 2004 to March 2009 was done. Age, sex, presenting features, radiological findings, histopathological type of the tumor and type of surgery were recorded and descriptive analysis was done to calculate frequencies, percentage and their relations. RESULTS: Out of total 51 cases, 81% (n=41) were benign and 19% (n=10) malignant tumors. Male to female ratio was 1:2.1. Mean age for benign and malignant tumors were 32.3 and 46.5 years respectively. Parotid tumor outnumbered all other sites comprising 69%, followed by submandiibular 18% and minor glands 13%. Pleomorphic adenoma was the commonest tumor (76%) of all primary salivary gland tumors. Benign to malignant tumor ratio of parotid, submandibular and minor glands were 6:1, 3.5:1 and 1.3:1 respectively. Adenoid cystic carcinoma (40%) and mucoepidermoid carcinoma (30%) were commonest malignant tumors. CONCLUSIONS: The principal site for salivary gland tumors in eastern Nepal population was the parotid and the pleomorphic adenoma outnumbered all other tumors. Most of the cases in both benign and malignant group presented with painless lump often misleading the gravity of disease.

Eccrine poroma in neck of a child--a rare presentation.

An eccrine poroma is a common benign tumour arising from the eccrine sweat gland duct epithelium in the dermo-epidermal region. Its occurrence in the neck region in pediatric age group is a rare entity. Here we report a case of an eccrine poroma in the retro-auricular area just below and behind the lobule of the left pinna in a nine years old child.

Fungal maxillary sinusitis: a prospective study in a tertiary care hospital of eastern Nepal.

INTRODUCTION: The incidence of mycotic infections and the diversity of pathogenic fungi have increased dramatically in recent years. Fungal sinusitis should be considered in all the patients with chronic maxillary sinusitis (CMS), especially in association with certain clinical features that serve as clue to the diagnosis. Aspergillus is the most common fungal pathogen in maxillary sinus. METHODOLOGY: A total of 100 patients those who fulfilled the diagnostic criteria (Lanza and Kennedy, 1992) for chronic rhinosinusitis were eligible for this open level and randomized prospective study. Only those above 14 years of age were included. RESULTS: Fungal maxillary sinusitis was seen in 14% of all cases of chronic maxillary sinusitis in eastern part of Nepal. We identified Acremonium and Candida species as commonest fungi involved in fungal maxillary sinusitis (FMS). To the best of our knowledge this is the first such study conducted in eastern Nepal.

Protein structure determination by non-parametric regression and knowledge-based constraints.

We have devised a non-parametric regression-based approach for the estimation of small- and medium-range inter-residual three-dimensional (3d) distances in a protein using only the primary sequence as input. A multivariate analysis of variance technique is used to identify the attributes of the primary sequence that is most effective in determining the tertiary structure. Certain compactness and hydrophobic core building heuristics are used along with the estimated distances in a distance geometry program to predict the 3d-structure (tertiary fold). Our method is found to predict correctly the native topologies of small proteins having up to 150 residues. The sensitivity of the structures to long-range distance constraints is studied by incorporating a small number of NMR distance restraints. In terms of modularity, precision, accuracy and computational efficiency our method is found to be better in comparison with current computational methods like X-PLOR and DRAGON on the sample that was reported in the literature for the comparison of these two methods.

Molecular dynamics simulation of a 13-mer duplex DNA: a PvuII substrate.

Parallel version of AMBER 4.1 was ported and optimised on the Indian parallel supercomputer PARAM OpenFrame built around Sun Ultra Sparc processors. This version of AMBER program was then used to carry out molecular dynamics (MD) simulations on 5'-TGACCAGCTGGTC-3', a substrate for PvuII enzyme. MD simulations in water are carried out under following conditions: (i) unconstrained at 300 K (230 ps); (ii) unconstrained at 283 K (500 ps); (iii) Watson-Crick basepair constrained at 283 K (1 ns); and (iv) Watson-Crick basepair constrained with ions at 283 K (1.2 ns). In all these simulation studies, the molecule was observed to be bending and maximum distortions in the double helix around was seen around the G7:C7' basepair, which is the phosphodiester bond that is cleaved by PvuII. Analysis of MD simulation with ions carried out for 1.2 ns also pointed out that the conformation of double helix alternates between a conformation close to B-form and close to A-form. It is argued that a bent non-standard conformation is recognised by the PvuII enzyme. The maximum bend occurs at the G7:C7' region, weakening the phosphodiester bond and allows His48 to get placed in such a fashion to permit the scission through a general base mechanism. The bending and distortion observed is a property of the sequence which acts as a substrate for PvuII enzyme. This is confirmed by carrying out MD studies on the Dickerson's sequence d(CGCGAATTCGCG)2 as a reference molecule, which practically does not bend or get deformed.

Current Progress in Anticalcif ication for Bioprosthetic and Polymeric Heart Valves.

The use of bioprosthetic valves fabricated from fixed heterograft tissue (porcine aortic valves or bovine pericardium) in heart valve replacement surgery is limited because of calcification-related failures. The mechanism of calcification of bioprosthetic valves is quite complex and has a variety of determinants, including host factors, tissue fixation conditions, and mechanical effects. Currently, there is no effective therapy to prevent calcification in clinical settings. This article reviews a variety of anticalcification strategies that are under investigation either in advanced animal models or in clinical trials. Bisphosphonates, such as ethan hydroxybisphosphonate (EHBP), inhibit calcium phosphate crystal formation. However, because of their systemic toxicity, they are used as either tissue treatments or polymeric site-specific delivery systems. Detergent treatment, such as sodium dodecyl sulfate (SDS), extracts almost all phospholipids from bioprosthetic heart valve cuspal tissue. Procedures, such as amino oleic acid pretreatment, inhibit calcium uptake. Polyurethane trileaflet valves, investigated as alternatives to bioprosthetic or mechanical valve prostheses, undergo intrinsic and thrombus-related calcification and degradation. Calcification- and thrombus-resistant polyurethanes synthesized in our laboratory by covalent linking of EHBP or heparin (either in bulk or on surface) by unique polyepoxidation chemistry are attractive candidates for further research. Tissue-engineered heart valves may have an important place in the future.

Calcification of polyurethanes implanted subdermally in rats is enhanced by calciphylaxis.

Calcification complicates the use of the polymer polyurethane in cardiovascular implants. To date only costly experimental circulatory animal models have been useful for investigating this disease process. In this paper we report that polyurethane calcification in rat subdermal implants is enhanced by overdosing with a vitamin-D analog. The calcification-prone state, known as calciphylaxis, was induced in 4-week old rats by oral administration of a vitamin-D analog, dihydrotachysterol. We studied two commercially available polyurethanes (Biomer and Mitrathane) and two proprietary polyurethanes (PEU-2000 and PEU-100). PEU-100 is unique because it is derivatized with ethanehydroxy-bisphosphonate (EHBP) for calcification resistance. Polyurethane calcium and phosphate levels and morphological changes due to calciphylaxis were compared with those of control rat subdermal explants in 60-day studies. Increased polyurethane mineralization was observed due to calciphylaxis with 60-day rat subdermal explants of Biomer, Mitrathane, and PEU-2000 (calcium levels, respectively, 4.13 +/- 0.56, 18.61 +/- 2.73, and 3.37 +/- 0.22 microgram/mg, mean +/- standard error) as compared to control explants (calcium levels, respectively, 1.22 +/- 0.1, 12.57 +/- 0.86, and 0.20 +/- 0.86 microgram/mg). The study also demonstrated that with 60-day implants calciphylaxis had no side effects on somatic growth and serum calcium levels. Explant surface morphology of these polyurethane explants examined by scanning electron microscopy, back scattering electron imaging coupled with energy dispersive X-ray spectroscopy, and light microscopy demonstrated the presence of predominantly surface-oriented calcification. PEU-100, derivatized with 100 n.moles/ mg of EHBP, resisted calcification with explant calcium levels 0.51 +/- 0.01 (calciphylaxis) and 0.38 +/- 0.01 (control) microgram/mg. It is concluded that calciphylaxis enhances superficial polyurethane calcification in rat subdermal implants and that an EHBP-modified polyurethane resists calcification despite calciphylaxis. Rat subdermal implants using calciphylaxis may be generally useful for evaluating the calcification potential of various biomedical polymers.

Chemoenzymatic synthesis of D(-)phenylglycine using hydantoinase of Pseudomonas desmolyticum resting cells.

We screened 125 Pseudomonas strains from our culture collection for the production of hydantoinase activity using DL-phenylhydantoin as a substrate. Pseudomonas desmolyticum NCIM 2112 was found to be the best hydantoinase (dihydropyrimidinase E.C. 3.5.2.2) producer. The enzymatic reactions were carried out using 18-20-h grown cells in nutrient broth and 5-phenylhydantoin as the substrate. Optimization studies for the biotransformation reaction were performed to increase product yield. The optimum pH and temperature for D(-)N-carbamoylphenylglycine production were 9.5 and 30 degrees C, respectively. Biotransformation under these alkaline conditions allowed the complete conversion of 27.0 g l-1 of DL-phenylhydantoin to 26.5 g l-1 of N-carbamoylphenylglycine within 24 h, with a molar yield of 90%. The hydantoinase involved in this biotransformation process was strictly D-stereospecific, because the product isolated was pure D(-)N-carbamoylphenylglycine. This pure product was further chemically converted to D(-)phenylglycine using nitrous acid with an 80% chemical yield. Thus, the overall conversion efficiency of DL-5-phenylhydantoin to D(-)phenylglycine was found to be 65-68%.

Probabilistic learning in immune network: weighted tree matching model.

Adaptive learning properties (of clonal selection and affinity maturation) in the immune network model are investigated in this paper under a nonlinear data structural representation of the involved molecules. Weighted trees are constructed to model the multiple paratopes/epitopes on the antibodies/antigens. Parallel computing experiments are carried out for the canonical coding of these trees and the corresponding multiple matching interactions. Our experiments on real data have shown significant results on the cognitive properties of the immune network. These and other computational results are presented along with a discussion of future applications.

A self-organizing cognitive network of antibody repertoire development.

A self-organizing cognitive network is mapped here onto the Id network model. The weight-vectors in this network represent some important topographical and biophysical parameters in the antibody-antigen affinity landscape. The Kohonen layers in the network correspond to affinity clones and the involved algorithm simulates the operations of clonal selection, hypermutation, differentiation, diversity, and affinity maturation. Two significant features of this model are: (i) a computationally feasible and biophysically informative representation of the para/epitopes, and (ii) the ability to perform simultaneous (parallel) and associative computations in a multidimensional shape-space. Computational experiments with real data have shown cognitive properties of this network. The results also indicate scope in quantitative characterization of the metadynamics of the above operations/weights in the adaptive development of the antibody repertoire.

Duplex and triplex directed DNA cleavage by oligonucleotide-Cu(II)/Co(III) metallodesferal conjugates.

Cu(II) desferal conjugated to d(T)10 at 5'-end is shown to direct the cleavage of single stranded 19-mer target DNA d(TA1GCCCGGCG), with a base preference G > C >> A. In contrast, the corresponding Co(II)-desferal conjugate directed the cleavage specific to only G sites (G12, G16, G17 and G19). Triplex targetting on the duplex 5'-TCCTGATAAAGGAGGAGATGAAGAAAAAATGA-3': 3'-AGGACTATTTCCTCCTCTACTTCTTTTTTACT-5', using Cu(II) desferal conjugated to 5'-end of 3'-TTTCCTCCTCT-5' directed the cleavage at G5.

Ab-Ag affinity thresholds in inventory optimization.

The role of antibody-antigen affinity and concentrations in adaptive antibody response is analyzed in a framework of probabilistic inventory model for antibody production. Our results indicate significant differences in optimal behaviours of low, moderate and high affinity groups and offer important implications. Interestingly, the involved approach is also of relevance in other production systems. Directions for its applications in industries and information sciences are also presented.