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Biomedical subjects

D Singh

Publications and source records attributed to D Singh.

At least 91 records · Page 5Linked to original sources
PubMed2001

Tibialis posterior tendon dysfunction: a primary or secondary problem?

Seventeen patients with a mean follow-up of 64.4 months following a tibialis posterior tendon transfer to regain active foot dorsiflexion were clinically examined specifically for signs of tibialis posterior tendon dysfunction. The results show that 8 patients (47%) had Grade 4 or better power of eversion but none had a clinical flatfoot on the Harris-Beath footprints. Only 6% had forefoot abduction; 17% exhibited hindfoot valgus and 82% were able to perform the single-heel rise. Tibialis posterior tendon dysfunction therefore does not appear to be an inevitable sequel of tibialis posterior tendon transfer even in the presence of a functioning peroneal muscle. Other studies have noted that a pre-existent flatfoot was often present in patients with tibialis posterior tendon dysfunction. None of the patients in this study had pre-existent flatfoot. We suggest that a predisposition, in the form of a pre-existent tendency to flatfoot may also be a factor in the pathogenesis of tibialis posterior tendon dysfunction. This may explain the long-term failure of flexor digitorum longus and flexor hallucis longus tendon transfers in the treatment for tibialis posterior tendon dysfunction when the biomechanics of the foot has not been altered.

Adolescent↗
PubMed2001

Tibialis posterior insufficiency occurring in a patient without peronei: a mechanical etiology.

A patient presented with a painful flatfoot deformity, which developed after the onset of a drop-foot secondary to a herniated lumbar disk. On examination, the only functioning muscles were her gastrocnemius-soleus complex and her intrinsic toe flexors. Her affected foot had taken the classic deformity seen with tibialis posterior dysfunction--a valgus heel, midfoot collapse and an abducted forefoot. Peroneus brevis was not functioning and therefore could not be implicated as part of the etiology of this patient's acquired flatfoot deformity. The mechanism in which the ground reaction force produces the foot deformity in a tibialis posterior insufficient foot will be presented.

Electromyography↗
PubMed2001

Quercetin, a bioflavonoid, protects against oxidative stress-related renal dysfunction by cyclosporine in rats.

Nephrotoxicity is the most common and clinically important side effect of cyclosporine (CsA). Recent evidence suggests that reactive oxygen species (ROS) play an important role in CsA nephrotoxicity. This study was designed to demonstrate the role of oxidative stress and its relation to renal dysfunction and to investigate the effects of quercetin, a bioflavonoid with antioxidant properties, in CsA-induced nephrotoxicity. Quercetin (0.5 and 2.0 mg/kg i.p.) was administered 24 h before and concurrently with CsA (20 mg/kg s.c.) for 21 days. Tissue lipid peroxidation was measured as thiobarbituric acid reacting substances (TBARS). Renal function was assessed by estimating plasma creatinine, blood urea nitrogen (BUN), creatinine and urea clearance. Renal morphological alterations were assessed histopathologically. Pretreatment with CsA (20 mg/kg s.c.) for 21 days produced elevated levels of TBARS and deteriorated renal function as assessed by increased plasma creatinine, BUN and decreased creatinine and urea clearance as compared to vehicle-treated rats. The kidneys of CsA-treated rats showed severe striped interstitial fibrosis, arteriopathy, glomerular basement thickening, tubular vacuolization and hyaline casts. Quercetin (2 mg/kg) markedly reduced elevated levels of TBARS and significantly attenuated renal dysfunction and morphological changes in CsA-treated rats. It is likely that quercetin, due to its antioxidant properties, prevented CsA-induced ROS and consequently CsA nephrotoxicity. These results clearly demonstrate the pivotal role of oxidative stress and its relation to renal dysfunction, and also point to the therapeutic potential of the natural antioxidant quercetin in CsA-induced nephrotoxicity.

Animals↗
PubMed2001

Toxic exposures.

Adolescence is a time of immense physical and social change. Risk-taking behavior is commonplace and often includes experimentation with various illicit drugs. Toxic ingestions remain a significant medical problem in this population. The major objective of this review is to provide an overview of the more common toxic exposures in adolescents. A framework is presented for understanding some of the factors that result in substance abuse in adolescents. Signs, symptoms and clinical manifestations of commonly abused drugs are presented along with general approaches to management of acute overdose. As the population of adolescents with underlying heart disease continues to grow, it is important for primary care providers to individualize treatment of adolescents with congenital or acquired heart disease. The impact of pre-existing cardiac disease is briefly reviewed.

Adolescent↗
PubMed2001

Health care workers with AIDS: the patient's right to know.

This paper discusses the relationship between a hospital patient and his healthcare worker who is HIV positive or has active AIDS. What are the actual and potential risks involved? How much is a patient entitled to know about the HIV status of his doctor, dentist or nurse? How much does a carer have to reveal in this regard to a patient? Case law is adduced and discussed in the light of current approaches to this problem.

Confidentiality↗
PubMed2001

An oligo astrocytoma with widespread calcification along axonal fibres.

A rare case of a young man with a diffusely calcified oligo astrocytoma in right parieto occipital region, which spread along the axonal fibres into right temporal lobe and to the left parietal lobe is presented. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated the extent of the lesion. The mass was partially resected.

Adult↗
PubMed2001

Febrile status epilepticus as the first presentation of cortical developmental malformation: report of 2 cases.

Cortical developmental malformations are an important cause for epilepsy. The epileptic disorder usually begins with sporadic seizures, followed by gradually increasing seizure frequency and culminating in epilepsia partialis continua. We report the de-novo occurrence of focal status epilepticus accompanying hyperpyrexia in two male children, aged 18 months and 4 years. One child had prior neuro-developmental delay, while in the other, developmental milestones were normal. In both instances, there were no seizures prior to the presenting neurological illness. Cerebrospinal fluid examination was normal in both the cases. Magnetic resonance imaging revealed extensive pachygyria in one patient and focal cortical thickening in the other. Therefore, cortical developmental malformation may be suspected as an underlying aetiology in children presenting with de-novo status epilepticus and hyperpyrexia.

Cerebral Cortex↗
PubMed2001

Disappearing cystic cerebellar medulloblastoma: the ghost tumour.

A case of medulloblastoma, which disappeared following steroid administration and a single sitting of radiotherapy (8Gy) is presented. At surgical exploration tumour was not found, multiple biopsies were negative. Post operative CT scan too did not show the tumour. Five months later, tumour reappeared in left cerebellar lobe in cystic and solid form. Patient was reoperated and tumour was decompressed. The biopsy showed medulloblastoma. To our knowledge, medulloblastomas are not known to be completely responsive to either of these modalities.

Adolescent↗
PubMed2001

Activity of glutathione related enzymes and ovarian steroid hormones in different sizes of follicles from goat and sheep ovary of different reproductive stages.

The investigations on enzymes related to glutathione like glutathione-S-transferase (GST) and glutathione peroxidase (GSH-Px) have been carried out mostly in human and rat ovaries, however the studies on these enzymes in ruminants are relatively absent. In the present study the changes in the activity of these enzymes, in different sizes of follicles from goat and sheep ovaries of different reproductive stages, were investigated. The results demonstrated that the activity of the enzyme GST increased with the increase in size of the follicles from small to large follicles of follicular phase ovary and from small to medium follicles of luteal phase ovary in both the species, thereafter it decreased in large follicles of luteal phase ovary. There was increasing pattern in the activity of GSH-Px in the follicular phase follicles and a decreasing pattern in the luteal phase follicles from both the species. Thus the changes in the activity of glutathione related enzymes namely GST and GSH-Px in different size follicles from both the species during different reproductive phases are evident from the results. It is reasonable, therefore, to assume that these enzymes may have functional role in the steroid hormone metabolism in ruminant ovary as reported in human ovary.

Animals↗
PubMed2001

Analysis of quantitative relationship between viability determination in leprosy by MFP, ATP bioluminescence and gene amplification assay.

Two hundred twenty-one untreated, borderline lepromatous/lepromatous (BL/LL) leprosy patients have been investigated for viability by the mouse foot pad method (MFP), adenosine triphosphate (ATP) and polymerase chain reaction (PCR). The biopsies were collected at the beginning of and 12/24 months after treatment. The patient group was treated with a) immunotherapy (BCG/Mw) + MDT; b) MDT + pyrazinamide; c) control MDT; d) MDT + minocycline 100 mg once a month supervised + ofloxacin 400 mg once a month supervised. Biopsies were divided in three parts for use in the mouse foot pad, molecular and ATP investigations. In untreated and treated patients (at 12 and 24 months), there was a general agreement among all three techniques, and PCR and ATP showed higher positivity as compared to MFP. Further, there was good correlation among the viable biomass estimated by bacillary ATP levels, PCR assay and growth in mouse foot pads. The positivity was observed by MFP as well as PCR assay (18-kDa and 36-kDa) from all of the specimens when the ATP content was more than 3.6 pg/million. When the ATP content was below 3.5 pg/million, the positive takes in MFP decreased but the PCR positivity correlated with ATP bioluminescence up to 0.04 pg/million. When the ATP content was even lower, the uptake in the MFP was possibly a matter of chance, while PCR positivity was observed in 96% of the cases. For specimens with undetectable ATP, positivity was seen in 1% of the cases, showing the inability of ATP bioluminescence method to detect low background due to host ATP. PCR signals in some cases could be due to the higher sensitivity of the method or persistence of DNA after bacterial death in some cases. On the whole, the PCR methods even though targeting DNA have shown good correlations with biomass which confirm their usefulness in monitoring therapeutic responses in leprosy.

Adenosine Triphosphate↗
PubMed2000

A novel form of "central pouchlike" cataract, with sutural opacities, maps to chromosome 15q21-22.

Congenital cataract is a clinically and genetically highly heterogeneous eye disorder, with autosomal dominant inheritance being most common. We investigated a large seven-generation family with 74 individuals affected by autosomal dominant congenital cataract (ADCC). The phenotype in this family can be described as "central pouchlike" cataract with sutural opacities, and it differs from the other mapped cataracts. We performed linkage analysis with microsatellite markers in this family and excluded the known candidate genes. A genomewide search revealed linkage to markers on chromosome 15, with a maximum two-point LOD score of 5.98 at straight theta=0 with marker D15S117. Multipoint analysis also gave a maximum LOD score of 5.98 at D15S117. Multipoint and haplotype analysis narrowed the cataract locus to a 10-cM region between markers D15S209 and D15S1036, closely linked to marker D15S117 in q21-q22 region of chromosome 15. This is the first report of a gene for a clinically new type of ADCC at 15q21-22 locus.

Cataract↗