Biomedical subjects
Publications and source records attributed to C Balachandran.
Acanthosis nigricans in children is usually associated with obesity. Generalized acanthosis nigricans in childhood is rare. We report a 13-year-old boy with an 8-year history of generalized hyperpigmentation and velvety thickening of the skin. Despite an extensive physical and laboratory examination no evidence of underlying endocrinological or neoplastic disease was found.
Verrucous papules and plaques on the plantar surfaces should not be assumed to be mere warts, especially if the history is unusual. We present a patient with an ulceroproliferative growth on the heel which was found to represent the epithelioma cuniculatum form of squamous cell carcinoma.
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A 32-year-old fisherman suffering from lepromatous leprosy presented with fever, joint pains, bullous lesions, and multiple well-defined ulcers on the extremities and back of 10-days duration. The bullae ruptured to form ulcers of varying sizes with well-defined margins and necrotic bases. A few of the ulcers had black crusts resembling eschars. An immunofluorescence study ruled out autoimmune bullous disease. Histopathology of a lesion showed features of erythema nodosum leprosum.
The present study was conducted to assess the haemagglutination-inhibition (HI) titres required to protect the chicken reproductive tract against direct damage caused by Newcastle disease virus (NDV). Precociously induced oviduct and uterus by oestrogen treatment of young chicks were used to assess the damage or protection against the damage by analysis of ciliostasis or histopathological lesions. Unvaccinated day-old female white leghorn chickens were used as the maternally derived antibody (MDA) group. Chickens were vaccinated with either a live lentogenic vaccine on day 14 of age or, along with it, an inactivated vaccine at day 36 of age, to generate birds with a range of primary or secondary response induced HI antibodies. Birds with different HI antibody levels were challenged with virulent NDV. It was found that a HI antibody titre of 128 and above was protective against direct damage of the reproductive tract, while the 32-64 titre range was protective when derived through secondary vaccination only.
PURPOSE: To compare sensitivity and specificity of functional and structural changes in glaucoma using two objective tests: the multifocal visual evoked potential (m-VEP) and Heidelberg retinal tomography II (HRT). PATIENTS AND METHODS: 41 glaucoma patients and 25 normal individuals participated in the study. One eye per individual was included in the study. Individuals were evaluated with Humphrey visual field (HVF) perimetry, m-VEP, and HRT. Moorfield regression analysis findings of HRT were compared with presence of scotoma on m-VEP. Linear regression analysis of quantitative variables, such as HVF mean deviation (MD), m-VEP discriminant score (Accumap Severity Index) and, global HRT parameters was also performed. RESULTS: m-VEP sensitivity and specificity were 93% and 96% respectively. HRT sensitivity and specificity were 79% and 92% respectively. The area under the receiver operating characteristic curve (ROC) for m-VEP was 0.96 and for HRT varied from 0.79 to 0.86 depending on the parameters used. Linear correlation between MD and Accumap Severity Index score was -77%, while that between HRT global parameters, Accumap Severity Index and MD were at best around 50%. Topographic comparison of the presence of scotoma on HVF and m-VEP in different areas of the visual field showed good agreement. Comparison of optic nerve head structural abnormality with corresponding areas of field defects on HVF and m-VEP showed poor to moderate agreement. CONCLUSION: The objective test of optic nerve function (m-VEP) and structure (HRT) can detect glaucomatous damage, with limited correlation. The 2 functional tests, HVF and m-VEP correlate better with each other than with HRT. It remains important to look for both functional and structural changes in order to detect all glaucoma cases.
Progressive Systemic Sclerosis is a chronic connective tissue disease characterized by sclerosis of skin with involvement of the internal organs. The cause of PSS is unknown but autoimmune mechanisms and primary damage to blood vessels have been proposed to explain its pathogenesis. We report a case of PSS with widespread depigmentation resembling vitiligo.
A 13-year-old boy presented with erythematous scaly plaques on the face and extremities with history of photosensitivity of 7-years duration. There was no history of oral ulcers or joint pains. Although the histopathological findings were inconclusive, a positive lupus band test confirmed the diagnosis of subacute cutaneous lupus erythematosus.
Mammary tumours are the most common neoplasms in female dogs. The present study was designed to evaluate the relationship between different clinical stages with activities of phase I and phase II carcinogen-metabolizing enzymes in canine mammary tumours. The levels of cytochrome P450 and cytochrome b5 and the activities of glutathione S-transferase (GST), gamma-glutamyl transpeptidase (GGT), DT-diaphorase (DTD) and NADPH diaphorase in tumour tissues of 25 bitches was estimated. Enhanced levels of cytochrome P450 and b5 and phase II enzyme activities were observed in tumour tissues compared to the corresponding uninvolved adjacent tissues. The magnitude of the changes in phase I and phase II enzyme status was, however, more pronounced in stages I and II compared to stages III and IV. The results suggest that the balance between phase I carcinogen activation and phase II detoxification systems may play an important role in canine mammary tumour development.
Thirty-six, twenty-eight-day-old broiler chicks were randomly distributed into three groups of 12 birds each. Two groups were fed diets containing 10 ppm cyclopiazonic acid (CPA) and 1ppm T-2 toxin, respectively, to determine the mechanism of cell death in spleen and thymus at 6, 12, 24, and 36 h of post-treatment. The other group served as control. T-2 toxin treated group showed significant (P < 0.01) induction of apoptosis in thymus with peak induction at 24 h post-treatment where as, no significant differences were observed between the control and CPA groups. The CPA toxin treated group showed significant (P < 0.01) induction of apoptosis in spleen with peak induction at 24 h post-treatment. No significant differences were observed between the control and T-2 toxin group even though the latter showed a slight increase in the quantity of apoptotic cells at 36 h post-treatment in spleen. The semi-thin sections stained with toluidine blue from the spleen of CPA treated group exhibited crescent margination of chromatin against the nuclear envelope and shrinkage of lymphoid cells without any surrounding inflammation, the characteristics of apoptosis. The apoptotic thymocytes from T-2 fed birds appeared shrunken with condensed nucleus and showed crescent margination of chromatin against the nuclear envelope without any surrounding inflammation when compared with well-defined nuclei with dispersed chromatin in normal thymocytes. Ultrastructurally, splenocytes of the CPA treated group and thymocytes of the T-2 toxin treated birds showed apoptotic bodies characterized by crescent margination of the chromatin against the nuclear envelope. The study indicates that one route of the CPA and T-2 toxin induced cell death in lymphoid organs of broiler chicken is by apoptosis.
Forty, newly hatched, unsexed broiler chicks were fed diets containing 10 ppm cyclopiazonic acid (CPA) and 1 ppm T-2 toxin (T2) either individually or in combination for 28 days to study the immunopathological effects. Lymphoid organs revealed lymphocytolysis and lymphoid depletion in all toxin fed birds. Thymic and splenic CD+4 and CD+8 lymphocytes decreased significantly (p<0.01) in toxin fed birds when compared to the control. Thymic CD+8 lymphocytes of T2 and CPA-T2 showed significant (p<0.01) decrease from that of CPA and control groups. Splenic CD+4 and CD+8 lymphocytes showed significant (p<0.01) decrease in CPA and CPA-T2 fed groups when compared to the control. The T2 group did not differ significantly from that of control. The stimulation index (SI) of splenocytes to concavalin A revealed significant (p<0.01) decrease in all toxin fed birds. Significant (p<0.01) decrease were observed for the haemagglutination inhibition (HI) titres to Newcastle disease virus vaccine F strain (NDV) of birds fed CPA, T2 and in combination. Significant (p<0.01) interaction was found for lymphocyte subsets, SI and HI titres to NDV. The study indicated the immunosuppressive effect of these toxins either alone or in combination in broiler chicks.
Mammary tumours are the most common neoplasms in female dogs. Oxidative stress arising due to overproduction of reactive oxygen species, coupled with altered antioxidant capacities has been implicated in the pathogenesis of all types of cancers. However, the extent of lipid peroxidation and the status of antioxidants in canine mammary tumours have not been investigated. The present study was designed to evaluate the oxidant-antioxidant profile in canine mammary tumours. Lipid peroxidation as evidenced by the formation of thiobarbituric acid-reactive substances, lipid hydroperoxides, and conjugated dienes, as well as the status of the antioxidants superoxide dismutase, catalase, reduced glutathione, glutathione peroxidase, glutathione S-transferase and vitamin C, in tumour tissues of 25 bitches was estimated. Lipid peroxidation in tumour tissues was enhanced compared to the corresponding adjacent uninvolved tissues. This was accompanied by significant elevation in both enzymatic and non-enzymatic antioxidants. This study suggests that upregulation of antioxidants induced by lipid peroxidation confers a selective growth advantage to tumour cells over their adjacent normal counterparts.
AIMS: To examine the ability of the multifocal pattern visual evoked potential (mVEP) to detect field loss in neurological lesions affecting the visual pathway from the chiasm to the cortex. METHOD: The mVEPs recorded in the clinic were retrospectively reviewed for any cases involving central neurological lesions. Recordings had been performed with the AccuMap V1.3 objective perimeter, which used an array of four bipolar occipital electrodes to provide four differently oriented channels for simultaneous recording. 19 patients with hemianopias were identified. Of these there were 10 homonymous hemianopias with hemifield type loss, two bitemporal hemianopias, and seven homonymous hemianopias with quadrantanopic distribution. A comparison with subjective field results and CT/MRI findings was done to determine the relation between the two methods of visual field mapping and any relation with the anatomical location of the lesion and the mVEP results. RESULTS: In all hemianopic type cases (12) the defect was demonstrated on the mVEP and showed good correspondence in location of the scotoma (nine homonymous and two bitemporal). The topographic distribution was similar but not identical to subjective testing. Of the seven quadrantanopic type hemianopias, only four were found to have corresponding mVEP losses in the same areas. In the three cases where the mVEP was normal, the type of quadrantanopia had features consistent with an extra-striate lesion being very congruous, complete, and respecting the horizontal meridian. CONCLUSIONS: The mVEP can detect field loss from cortical lesions, but not in some cases of homonymous quadrantanopia, where the lesion may have been in the extra-striate cortex. This supports the concept that the mVEP is generated in V1 striate cortex and that it may be able to distinguish striate from extra-striate lesions. It implies caution should be used when interpreting "functional" loss using the mVEP if the visual field pattern is quadrantic.
AIM: To determine the efficacy and safety of perfluorocarbon liquid as a short term postoperative tamponade in patients with retinal detachment from giant retinal tears. METHOD: A retrospective consecutive case series of patients with retinal detachment from giant retinal tears who underwent vitrectomy using perfluorocarbon liquid as a short term postoperative internal tamponade. The perfluorocarbon liquid was removed 5-14 days (mean 7.5 days) later and replaced by gas or silicone oil. Scleral buckling was performed in some cases with proliferative vitreoretinopathy. The crystalline lens was removed if there was interference with the surgical view or if it was subluxated. The success rate of retinal reattachment, visual outcome, and postoperative complications were assessed. RESULTS: A total of 62 eyes of 61 patients with a follow up of 8-69 months (mean 24.5 months) were included. All retinas were attached intraoperatively. 14 eyes (22.6%) developed re-detachment and additional operations were performed in 13 eyes. At final visit, 58 eyes (93.5%) had retinas that remained attached with visual acuity 6/12 or better in 27 eyes (46.5%). The visual acuity improved in 34 eyes (54.8%) with 28 eyes (45.2%) improving at least two Snellen lines, it was unchanged in 20 eyes (32.3%), and was worse in eight eyes (12.9%). Three patients developed glaucoma that was controlled medically. There was no retained perfluorocarbon liquid in any eyes. CONCLUSION: Perfluorocarbon liquid appears safe and effective to use as a short term postoperative tamponade in management of retinal detachment from giant retinal tears.
Forty newly hatched unsexed Japanese quail (Coturnix coturnix japonica) chicks were fed diets containing 3 ppm aflatoxin (AF) and 4 ppm T(2) toxin either singly and in combination for 35 days. Sera samples were collected from six birds in each group at the end of the trial to study the effect of certain serum biochemical parameters. Highly significant (P < 0.01) differences were observed for serum total protein, albumin, globulin, glucose, cholesterol, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and gamma glutamyl transferase (GGT) between control and toxin treated groups. Toxin treated groups did not reveal any significant difference for serum urea nitrogen, creatinine, uric acid, calcium, phosphorus, sodium and potassium. There was a reduction in the levels of serum total protein, albumin, globulin, glucose, cholesterol, ALT and elevation of AST and GGT and variable ALP levels observed in toxin treated groups.
AIM: To study the maturation of multifocal visual evoked potentials (multifocal VEP) in normal children between the ages of 5 and 16 years and to apply the results clinically in selected cases to the diagnosis of optic pathway diseases. METHOD: 70 normal children were recruited from the community and multifocal VEP (Accumap ObjectiVision, Sydney, Australia) was recorded. The waveform of the evoked responses, the latency and amplitude were analysed. Using these data, an age matched comparison was made with three children with advanced optic nerve disease; two had optic nerve glioma and one had congenital glaucoma. RESULTS: The full field amplitude did not correlate with age and varied greatly within each age group (coefficient of variability 28%). When scaled with respect to the background electroencephalogram the intra-age group variability decreased to 15% and a sigmoid relation was found between amplitude and age. The scaled amplitude remained largely unchanged till 11 years, between 11 and 13 years there was a rapid increase (40%), and remained stable thereafter. This relation was seen at all eccentricities tested. The latency decreased gradually with age and plateaued at 13 years. In the three children with vision abnormalities this test was able to detect scotomas consistent with their condition. CONCLUSION: Multifocal VEP perimetry shows an age related maturation in the visual pathway, characterised by distinctive timeframe of development for amplitude and latency. It can be performed by children as young as 5 years of age and holds promise as a diagnostic test capable of documenting children's visual fields objectively, even before they are able to perform subjective field tests.
A 58-year old woman had anaphylactic reaction two hours after oral administration of paracetamol. She was treated conservatively and responded favourably. This incident is being reported as anaphylaxis to paracetamol which is rare. Whenever there is history of allergy to other non-narcotic analgesic drugs, paracetamol sensitivity should be tested under medical supervision.
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