Biomedical subjects
Publications and source records attributed to B Singh.
We report a humeral fracture associated with complete radial nerve palsy, where immediate nerve recovery followed decompression. This uncommon type of nerve lesion is referred to as axonamonosis and is not included in the traditional Seddon nerve injury classification.
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Bacterial diseases, especially those of the lung caused by Gram-negative bacteria, inflict significant economic loss associated with mortality and morbidity in domestic animals. Toll-like receptor 4 (TLR4) has recently been recognized as a major receptor for cellular interactions with lipopolysaccharides derived from Gram-negative bacteria. However, there are no data on the expression of TLR4 in various organs of domestic animals. We performed immunohistochemistry and immuno-gold electron microscopy to localize TLR4 in lung and seven other organs from normal pig, dog and calf (n=2 each) and in inflamed lungs from calves (n=4) challenged with Mannheimia hemolytica. The data show TLR4 in macrophages in lung, small intestine, liver and spleen in all the species and pulmonary intravascular macrophages in calves and pigs. Epithelium in lung, small intestine, cornea and convoluted and straight renal tubules was stained for TLR4. Vascular endothelium of large blood vessels only in lungs and skin was positive, and skeletal muscles were negative for TLR4. In inflamed lungs, airway epithelium showed reduced staining for TLR4 while staining in macrophages remained unaltered. These are the first immunocytochemical data on TLR4 expression in domestic animal species and show similarity in TLR4 staining in macrophages, epithelium and vascular endothelium among dog, pig and cattle.
Pediatric dentists often come across lesions in neonates, the most common ones being Bohn's nodules and Epstein Pearls. Other common lesions seen in the oral cavity of neonates are congenital epulis, hemangiomas and mucus extravasation cysts. Mucus extravasation phenomenon is generally encountered over the lip but rarely seen over the alveolar ridge. Presented here is a case of a 1-month-old baby with a mucus extravasation cyst measuring 0.7 x 1 cm in size over the alveolar ridge.
INTRODUCTION: Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) is a rare, neurodegenerative and fatal disease caused by mutations in the mitochondrial DNA. Multiple systems of the body, including the oral cavity, can be affected by this disease. An electronic search of Medline spanning the years 1985 to 2003 was carried out using the key words "MELAS, Dentistry." It yielded no literature on the dental aspects of MELAS. CLINICAL PICTURE: This report documents the case of a 6-year-old Chinese boy diagnosed with MELAS and highlights problems encountered in the multidisciplinary management of MELAS patients, including its dental management. TREATMENT AND OUTCOME: Dental management was successfully performed under general anaesthesia with close medical supervision by paediatrician and anaesthetist. CONCLUSIONS: There is no known treatment of the underlying disease and the clinical course is usually unpredictable. Preventive dental care is important in this group of patients as concurrent medical conditions can complicate dental care.
This article highlights 2 contrasting lesions of the floor of the mouth, the first being a benign lipoma growth and the latter, an adenoid cystic carcinoma. Both of these lesions appear clinically similar, presenting as a swelling with normal overlying mucosa and otherwise asymptomatic at the time of clinical examination. As the swelling for Case 1 is small and fluctuant, no special investigation was ordered, whereas a computed tomographic scan was ordered for the larger expansile lesion in Case 2. The lesions were excised under local and general anaesthesia respectively and a histology henceforth. Recovery for both cases were uneventful and no recurrence or complication was noted to date when this article was written. The two extreme natures of the lesions manifested in the region serve as a cautionary note to clinicians.
The growth of dermoid cysts at the floor of the mouth is considered a rare condition. Typically, intra-oral dermoid cysts present as non-tender, slow growing masses at the sublingual, submental and submandibular region. We report a case of a young adult male who presented at our hospital with a sublingual cyst superimposed with acute infection and failed antibiotic treatment. The cyst was excised and confirmed histopathologically as a dermoid cyst with overlying acute inflammation. Clinical progress was uneventful and postoperative recovery excellent with no recurrence.
Cardiac sympathetic denervation for intractable angina pectoris in patients unsuitable for conventional revascularization is currently gaining popularity since this procedure may be performed via minimally invasive surgery. A thorough understanding of cardiac innervation and its variations is crucial to successfully effect cardiac denervation. This study aimed to demonstrate the cervical and thoracic sympathetic contributions to the cardiac plexus. The cervical and thoracic sympathetic trunks in 21 fetuses and eight adults were micro-dissected bilaterally and documented ( n=58 sides). The superior cervical cardiac ramus originated from the superior cervical ganglion (present in all specimens) in 53% of cases. The middle cervical ganglion (incidence 81%) gave rise to the middle cervical cardiac ramus in 88% of cases. The cervico-thoracic ganglion (incidence 85%) gave the cervico-thoracic cardiac ramus in 84%. In the thoracic region, four cardiac rami arose from the T2-T6 segment of the thoracic sympathetic trunk. All cervical and thoracic cardiac rami were traced consistently to the deep cardiac plexus. Khogali et al.'s (1999) success of limited T2-T4 sympathectomy in relieving pain at rest of patients with intractable angina pectoris appears to indicate that a significant afferent pain pathway from the heart is selectively interrupted. The variability in pattern of the cervical ganglia, cardiac rami and cervical contributions to the cardiac plexus does not appear to affect the outcome of limited sympathectomy. The complexity of cardiac pain pathways is not fully understood. The study is continuing and attempts to contribute to defining these cardiac neuronal pathways.
The uptake of arsenic (As) by plants from contaminated soils presents a health hazard that may affect the use of agricultural and former industrial land. Methods for limiting the hazard are desirable. A proposed remediation treatment comprises the precipitation of iron (Fe) oxides in the contaminated soil by adding ferrous sulfate and lime. The effects on As bioavailability were assessed using a range of vegetable crops grown in the field. Four UK locations were used, where soil was contaminated by As from different sources. At the most contaminated site, a clay loam containing a mean of 748 mg As kg(-1) soil, beetroot, calabrese, cauliflower, lettuce, potato, radish and spinach were grown. For all crops except spinach, ferrous sulfate treatment caused a significant reduction in the bioavailability of As in some part of the crop. Application of ferrous sulfate in solution, providing 0.2% Fe oxides in the soil (0-10 cm), reduced As uptake by a mean of 22%. Solid ferrous sulfate was applied to give concentrations of 0.5% and 1% Fe oxides: the 0.5% concentration reduced As uptake by a mean of 32% and the 1% concentration gave no significant additional benefit. On a sandy loam containing 65 mg As kg(-1) soil, there was tentative evidence that ferrous sulfate treatment up to 2% Fe oxides caused a significant reduction in lettuce As, but calabrese did not respond. At the other two sites, the effects of ferrous sulfate treatment were not significant, but the uptake of soil As was low in treated and untreated soils. Differences between sites in the bioavailable fraction of soil As may be related to the soil texture or the source of As. The highest bioavailability was found on the soil which had been contaminated by aerial deposition and had a high sand content.
The nerve of Kuntz and alternate neural pathways (ANPs) have long been considered crucial for upper limb sympathetic supply. However, at thoracoscopy, these structures are neither consistently identified nor searched for. This is probably reflective of the effectiveness of an isolated second thoracic ganglionectomy for upper limb sympathectomy. We present the case of a 19-year-old male who underwent a second thoracic ganglionectomy for palmar hyperhidrosis. On the left side, approximately 2.5 cm lateral to the typically located sympathetic chain, a filamentous structure (one-quarter the diameter of the sympathetic chain), identified as the nerve of Kuntz, was noted coursing across the neck of the second rib.
In this new era of minimal access surgery, advances in optics and illumination have established thoracoscopic sympathectomy as a pre-eminent procedure, including a safe and efficient technique for upper limb sympathectomy. The success of thoracoscopy will doubtless ensure that a greater number of these procedures will be carried out and will put some of the daunting technical challenges posed by traditional open surgical procedures to rest. The thoracoscopic era affords the surgical anatomist a new challenge: to move the teaching of living anatomy to a higher level.
In the Indian traditional system of medicine Withania somnifera Dun. is widely regarded as the Indian Ginseng. A new withanolide-free hydrosoluble fraction was isolated from the roots of Withania somnifera Dun. and was evaluated for putative antistress activity against a battery of tests to delineate the activity of this fraction. The latter fraction exhibited significant antistress activity in a dose-related manner (Singh et al., 2001) and was further studied against chemical and physical induced stress in rats and mice. The extract of Withania somnifera root (a commercial preparation available locally) was also used to compare the results. A preliminary acute toxicity study in mice showed a good margin of safety with a high therapeutic index.
T. amplexicaule Roth. has been investigated phytochemically for biologically active constituents from the benzene extract. This yielded a mixture of terpenoids: beta-sitosterol, alpha-amyrin, lupeol, hexacosanoic acid, ceryl alcohol and hexacosane. The sequential extracts, isolated terpenoids and reference antibiotics were screened for their possible bioactivities against selected pathogenic bacteria, Escherichia coli, Staphylococcus aureus and fungi, Aspergillus flavus and Penicillium chrysogenum etc. Out of the sequential extracts, the benzene extract was more potent against S. aureus (IZ = 10.36) and R. phaseoli (IZ = 10.69). The inhibition zones of isolated terpenoids were also recorded and the activity index was calculated and it was found that hexacosane was more active (IZ = 13.39) against E. coli and hexacosanoic acid had greater activity against A. flavus (IZ = 11.56). The present study deals with antimicrobial screening of sequential extracts and isolated terpenoids.
OBJECTIVE: To investigate, if, urinary iodine contents as a marker of iodine deficiency and hypothyroidism are associated with the incidence of neonatal hyperbilirubinemia. METHODS: One hundred neonates with total serum bilirubin > or = 15 mg/dl and with no known cause of jaundice were included in the study as a jaundice group. An equal number (n = 100) of non-jaundiced neonates (bilirubin < or = 14.9 mg/dl) with matching for age, gestation period and weight were enrolled in the study as a control group. RESULTS: Thirteen neonates (13%) in the study group had urinary iodine levels < 100 mg/dl as against only 2 (2%) in the control group (p < 0.05). Thirty-four (34/200-17%) neonates i.e. 17 each in the study and control groups had serum TSH > 5 mU/ml and hence an indirect indicator of iodine deficiency in the study population. The mean serum levels of total T3, T4 and TSH in the study neonates were 1.52 +/- 1.23 ng/ml, 15.8 +/- 12.0 micrograms/dl & 3.13 +/- 3.0 mU/ml respectively and did not differ significantly from the mean levels in the control group. Only one neonate in the study group had serum TSH > 20 mU/ml which was suggestive of hypothyroidism, but had normal T3 & T4. Seven neonates in the study group and 8 in the control group had low T4. There was no significant correlation between the maternal and neonatal urine iodine levels, thyroid functions and the bilirubin levels (p > 0.01). CONCLUSION: The jaundiced babies had lower urine oidine levels than the control population. Since, there was no significant difference in the levels of the thyroid hormones, no cause and effect relationship could be inferred between iodine deficiency and jaundice.
Thirty-two patients reporting to the Lundu District Hospital, Sarawak, Malaysian Borneo, with uncomplicated falciparum malaria were recruited into a multifaceted study to assess treatment response. Following combined chloroquine and sulphadoxine/pyrimethamine treatment the patients were followed for 28 days according to the World Health Organisation in vivo drug response protocol. The in vivo study revealed that 13 (41%) of the patients had a sensitive response to treatment, five (16%) cleared asexual stage parasites but had persistent gametocytes, 11 (34%) had RI type resistance and three (9%) had RII type resistance requiring quinine intervention before day 7 for parasite clearance. Although clinically insignificant, patients with persistent gametocytes, surviving chloroquine and sulphadoxine/pyrimethamine treatment during maturation, were placed in the reduced response to treatment group for analysis. Allelic typing detected 100% prevalence of the pfcrt K76T marker associated with chloroquine resistance and 78% prevalence of the pfdhfr NRNL haplotype associated with sulphadoxine/pyrimethamine treatment failure. High serum chloroquine levels and pfdhfr haplotypes with <or=2 point mutations were independently associated with a sensitive response to treatment. However four patients in the sensitive response group had both low serum chloroquine levels and the pfdhfr NRNL haplotype. A degree of immunity, consistent with malaria endemicity, may account for the apparently paradoxical presence of markers of drug resistance in the sensitive group.
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Peri-urban agriculture is vital for the urban populations of many developing countries. Increases in both industrialization and urbanization, and associated air pollution threaten urban food production and its quality. Six hour mean concentrations were monitored for SO(2), NO(2) and O(3) and plant responses were measured in terms of physiological characteristics, pigment, biomass and yield. Parameter reductions in mung bean (Vigna radiata), palak (Beta vulgaris), wheat (Triticum aestivum) and mustard (Brassica compestris) grown within the urban fringes of Varanasi, India correlated directly with the gaseous pollutants levels. The magnitude of response involved all three gaseous pollutants at peri-urban sites; O(3) had more influence at a rural site. The study concluded that air pollution in Varanasi could negatively influence crop yield.