The relative quantum yield of diethyl 2-acetamido-2-((3-oxo-3H-benzo[f]chromen-1-yl)methyl) malon... more The relative quantum yield of diethyl 2-acetamido-2-((3-oxo-3H-benzo[f]chromen-1-yl)methyl) malonate [2DAM] is estimated using single point method with quinine sulfate as standard reference. The quantum yield varies between 0.1161 and 0.3181 depending on the nature of the solvent. The rates of radiative and non radiative decay constants are also calculated. The fluorescence quenching of [2DAM] by aniline is studied at room temperature, by steady state, in five different solvents namely acetonitrile (AN), 1,4 dioxane (DX), 1,2 dichloroethane (DCE), tetrahydrofuran (THF) and toluene (TOL), in order to explore various possible quenching mechanisms. The experimental results show a positive deviation in Stern Volmer plots for all solvents. Various parameters for the quenching process are determined by ground state complex, sphere of action static quenching model and finite sink approximation model. The magnitudes of these rate parameters indicate that positive deviation in the Stern–Volmer (SV) plot.
The Journal of the Association of Physicians of India
Fourteen patients of Early Onset Cerebellar Ataxia with retained tendon reflexes (EOCA) were pros... more Fourteen patients of Early Onset Cerebellar Ataxia with retained tendon reflexes (EOCA) were prospectively evaluated clinically, electorphysiologically and with CT scan. Their age and duration of symptoms were 18.6 +/- 8.3 years and 7.8 +/- 5.1 years respectively. High consanguinity (91.7%) and positive family history (76.9%) suggested autosomal recessive inheritance. Apart from cerebellar signs and brisk knee jerks in all, other important findings were abnormal ocular movements (mostly impaired saccades) in 92.8%, Babinski's sign (78.6%), brisk ankle jerks (64.3%), spasticity in lower limbs (50%) and impairment of proprioceptive sensations (50%). Neuropsychological tests, done in 12 patients, were abnormal in all. Abnormalities of electroneuromyographic studies were universal, motor conduction parameters (85.7%) being more affected than sensory (78.6%). One or more modalities of evoked potentials were abnormal in 71.4%, that of brainstem auditory evoked response being most freq...
This prospective study was undertaken to characterize better electrophysiologically the newly des... more This prospective study was undertaken to characterize better electrophysiologically the newly described clinical entity of "Early onset cerebellar ataxia with retained tendon reflexes (EOCA)" and compare it with Olivopontocerebellar atrophy (OPCA) and Friedreich's ataxia (FA). Concentric needle electromyography and motor (median, common peroneal and posterior tibial) and sensory (median, sural and posterior tibial) nerve conduction studies were carried out in 14 patients of EOCA. The results were compared with those of 10 and 16 patients of FA and OPCA respectively. All patients of EOCA had either motor or sensory conduction abnormalities, motor being slightly more frequent than sensory (87.7% versus 78.6%). The neuropathy was distal and symmetrical, lacked correlation with duration or clinical stage of the disease, even between patients of the same family. Electrophysiological studies helped to detect subclinical motor and sensory neuropathy in most of the patients. N...
The Journal of the Association of Physicians of India, 1998
Morbidity and mortality in puerperal cerebral venous thrombosis (CVT) can be reduced by arresting... more Morbidity and mortality in puerperal cerebral venous thrombosis (CVT) can be reduced by arresting the progression of thrombosis using heparin. However, conventional dose of heparin requires monitoring of coagulation parameters and carries a risk of haemorrhage. The present study involved 56 patients of puerperal CVT with CT evidence of haemorrhagic infarction. Twenty nine of these patients received low dose heparin till 30th post-partum day or symptomatic relief. Their clinical features and severity were similar to 27 patients who did not receive heparin. The mortality and morbidity at discharge was significantly less (P < 0.001) in heparin treated group. There were no haemorrhagic complications. Low dose heparin is safe and effective in cerebral venous thrombosis, even with haemorrhagic infarction.
Electromyography and clinical neurophysiology, 1995
There is agreement on the clinical diagnostic criteria for acute inflammatory demyelinating polyn... more There is agreement on the clinical diagnostic criteria for acute inflammatory demyelinating polyneuropathy (AIDP/GBS) however, there is lack of consensus for detection of demyelination. In order to critically evaluate the prevailing criteria, sixty-six patients who fulfilled NINCDS criteria and had typical features of GBS were studied for electrophysiological abnormalities of peripheral nerves by using standard methods (median, common peroneal, sural and ulnar) between 1 to 12 weeks after the onset of symptoms. The commonest abnormality on motor nerve conduction study was prolonged distal latency (75%-83%) followed by reduction in CMAP amplitude (63%-82%), decreased velocity (48%-62%), conduction block (17%-39%) and f-wave abnormalities (37.8%-59%). Sensory conduction abnormalities were detected in over 20% of median, 25% of ulnar and 33% of sural nerves. All the patients had abnormality of at least two motor conduction parameters in one nerve when values beyond 2 SD of the mean wer...
A deficiency of plasma antithrombin III has been identified as a potential risk factor for thromb... more A deficiency of plasma antithrombin III has been identified as a potential risk factor for thrombosis. In a pilot study of 56 patients aged less than 40 years who presented with ischaemic stroke of unknown etiology, we detected only one case of plasma antithrombin III deficiency. Antithrombin III activity was estimated by a chromogenic assay. Hence, antithrombin III deficiency, though rare, should be considered while evaluating young patients with stroke of unknown etiology.
The Journal of the Association of Physicians of India, 1999
The cause of stroke in the young remains unknown in 20-50% of the patients. Infections preceding ... more The cause of stroke in the young remains unknown in 20-50% of the patients. Infections preceding stroke have been recently recognised to be an independent risk factor of stroke. Sixty consecutive patients aged 40 years or less presenting with ischaemic completed stroke are taken up for the study. Patients with neurological deficit of less than 24 hours, evidence of haemorrhage on CT scan, infection occurring after the onset of stroke were excluded. Controls consisted of age and sex matched persons residing in the same area. Both the groups were enquired about preceding fever and infections and were examined for evidence of infections. Serum was examined for antibodies against measles, herpes simplex, and Japanese B encephalitis viruses. Cultures were put up from appropriate samples and CSF examined in patients only. Evidence of infection was noted in 26 (43.3%) of patients and 6 controls (p < 0.001). History of fever was elicited in 23 patients and 3 controls while 15 patients we...
The Journal of the Association of Physicians of India, 1990
Two patients with internal carotid disease and normal/hypoplastic vertebro-basilar system present... more Two patients with internal carotid disease and normal/hypoplastic vertebro-basilar system presenting with symptoms of vertebrobasilar insufficiency are presented. The role of associated anomalies of the circle of Willis or major vessels in the pathogenesis of symptoms is highlighted.
The Journal of the Association of Physicians of India, 1995
Of the 220 patients of acute idiopathic demyelinating polyneuritis (AIDP/GBS) seen over a seven y... more Of the 220 patients of acute idiopathic demyelinating polyneuritis (AIDP/GBS) seen over a seven year period, 15 patients (M:F:11:4) had a relapsing course (6.8%). Their ages ranged from 8 yrs to 70 yrs. They had 36 episodes at a variable interval of 3 months to 25 yrs. Relapse rate varied from one to four. Antecedent events were noted during 16 episodes in 9 patients but the triggering factors were varied. Clinical features of individual episodes were similar to the acute monophasic illness, although they differed inseverity from one episode to the other. Autonomic disturbances were rare. Albuminocytological dissociation was observed during 19 of the 24 episodes. Electrophysiological abnormalities were observed during 19 of the 24 episodes. Electrophysiological abnormalities were present in all and were comparable with patients of non-recurrent illness. Sural nerve biopsy in 3 patients showed evidence of demyelination, remyelination, Wallerian degeneration and myelin breakdown but n...
The Journal of the Association of Physicians of India, 1989
A sixty two year old man who presented with tremors of trunk and lower limbs, appearing only on s... more A sixty two year old man who presented with tremors of trunk and lower limbs, appearing only on standing, is reported. The tremor frequency was 14-16 Hz and there was co-contraction of antagonistic muscles. No therapeutic benefit was noted with propranolol, primidone and diazepam. The possible pathogenesis of this rare orthostatic trunkal tremor and its relationship with essential tremor are discussed.
Stroke is a leading cause of deaths, and disabilities in India. Reliable and good quality data on... more Stroke is a leading cause of deaths, and disabilities in India. Reliable and good quality data on epidemiological characteristics of stroke are essential to plan, implement and evaluate stroke prevention and control programmes. A feasibility study was undertaken in Bangalore to examine the possibility of establishing stroke surveillance and to develop methodology for a larger programme. The study adapted WHO STEPs-STROKE methodology to collect data on hospitalized stroke events and fatal stroke events in the city of Bangalore. In STEP I, Information was collected from 1,174 stroke patients in three large hospitals and were followed till discharge and 28 days; outcome was measured as death or disability. Stroke cases fulfilling diagnostic criteria, evaluated by neurologists and CT/MRI confirmed cases were included. Brief information on major risk factors was collected from all stroke patients / family members and from medical records by trained research officers. In STEP II, death re...
A patient with Sturge-Weber-Dimitri disease presented with intractable seizures and progressive i... more A patient with Sturge-Weber-Dimitri disease presented with intractable seizures and progressive intellectual deterioration. There was no facial nevus or focal neurologic abnormality. CT disclosed bilateral calcification in a parieto-occipital gyral pattern. Histopathology of the brain revealed extensive calcification of vessel wall in parieto-occipital cortices.
The relative quantum yield of diethyl 2-acetamido-2-((3-oxo-3H-benzo[f]chromen-1-yl)methyl) malon... more The relative quantum yield of diethyl 2-acetamido-2-((3-oxo-3H-benzo[f]chromen-1-yl)methyl) malonate [2DAM] is estimated using single point method with quinine sulfate as standard reference. The quantum yield varies between 0.1161 and 0.3181 depending on the nature of the solvent. The rates of radiative and non radiative decay constants are also calculated. The fluorescence quenching of [2DAM] by aniline is studied at room temperature, by steady state, in five different solvents namely acetonitrile (AN), 1,4 dioxane (DX), 1,2 dichloroethane (DCE), tetrahydrofuran (THF) and toluene (TOL), in order to explore various possible quenching mechanisms. The experimental results show a positive deviation in Stern Volmer plots for all solvents. Various parameters for the quenching process are determined by ground state complex, sphere of action static quenching model and finite sink approximation model. The magnitudes of these rate parameters indicate that positive deviation in the Stern–Volmer (SV) plot.
The Journal of the Association of Physicians of India
Fourteen patients of Early Onset Cerebellar Ataxia with retained tendon reflexes (EOCA) were pros... more Fourteen patients of Early Onset Cerebellar Ataxia with retained tendon reflexes (EOCA) were prospectively evaluated clinically, electorphysiologically and with CT scan. Their age and duration of symptoms were 18.6 +/- 8.3 years and 7.8 +/- 5.1 years respectively. High consanguinity (91.7%) and positive family history (76.9%) suggested autosomal recessive inheritance. Apart from cerebellar signs and brisk knee jerks in all, other important findings were abnormal ocular movements (mostly impaired saccades) in 92.8%, Babinski's sign (78.6%), brisk ankle jerks (64.3%), spasticity in lower limbs (50%) and impairment of proprioceptive sensations (50%). Neuropsychological tests, done in 12 patients, were abnormal in all. Abnormalities of electroneuromyographic studies were universal, motor conduction parameters (85.7%) being more affected than sensory (78.6%). One or more modalities of evoked potentials were abnormal in 71.4%, that of brainstem auditory evoked response being most freq...
This prospective study was undertaken to characterize better electrophysiologically the newly des... more This prospective study was undertaken to characterize better electrophysiologically the newly described clinical entity of "Early onset cerebellar ataxia with retained tendon reflexes (EOCA)" and compare it with Olivopontocerebellar atrophy (OPCA) and Friedreich's ataxia (FA). Concentric needle electromyography and motor (median, common peroneal and posterior tibial) and sensory (median, sural and posterior tibial) nerve conduction studies were carried out in 14 patients of EOCA. The results were compared with those of 10 and 16 patients of FA and OPCA respectively. All patients of EOCA had either motor or sensory conduction abnormalities, motor being slightly more frequent than sensory (87.7% versus 78.6%). The neuropathy was distal and symmetrical, lacked correlation with duration or clinical stage of the disease, even between patients of the same family. Electrophysiological studies helped to detect subclinical motor and sensory neuropathy in most of the patients. N...
The Journal of the Association of Physicians of India, 1998
Morbidity and mortality in puerperal cerebral venous thrombosis (CVT) can be reduced by arresting... more Morbidity and mortality in puerperal cerebral venous thrombosis (CVT) can be reduced by arresting the progression of thrombosis using heparin. However, conventional dose of heparin requires monitoring of coagulation parameters and carries a risk of haemorrhage. The present study involved 56 patients of puerperal CVT with CT evidence of haemorrhagic infarction. Twenty nine of these patients received low dose heparin till 30th post-partum day or symptomatic relief. Their clinical features and severity were similar to 27 patients who did not receive heparin. The mortality and morbidity at discharge was significantly less (P < 0.001) in heparin treated group. There were no haemorrhagic complications. Low dose heparin is safe and effective in cerebral venous thrombosis, even with haemorrhagic infarction.
Electromyography and clinical neurophysiology, 1995
There is agreement on the clinical diagnostic criteria for acute inflammatory demyelinating polyn... more There is agreement on the clinical diagnostic criteria for acute inflammatory demyelinating polyneuropathy (AIDP/GBS) however, there is lack of consensus for detection of demyelination. In order to critically evaluate the prevailing criteria, sixty-six patients who fulfilled NINCDS criteria and had typical features of GBS were studied for electrophysiological abnormalities of peripheral nerves by using standard methods (median, common peroneal, sural and ulnar) between 1 to 12 weeks after the onset of symptoms. The commonest abnormality on motor nerve conduction study was prolonged distal latency (75%-83%) followed by reduction in CMAP amplitude (63%-82%), decreased velocity (48%-62%), conduction block (17%-39%) and f-wave abnormalities (37.8%-59%). Sensory conduction abnormalities were detected in over 20% of median, 25% of ulnar and 33% of sural nerves. All the patients had abnormality of at least two motor conduction parameters in one nerve when values beyond 2 SD of the mean wer...
A deficiency of plasma antithrombin III has been identified as a potential risk factor for thromb... more A deficiency of plasma antithrombin III has been identified as a potential risk factor for thrombosis. In a pilot study of 56 patients aged less than 40 years who presented with ischaemic stroke of unknown etiology, we detected only one case of plasma antithrombin III deficiency. Antithrombin III activity was estimated by a chromogenic assay. Hence, antithrombin III deficiency, though rare, should be considered while evaluating young patients with stroke of unknown etiology.
The Journal of the Association of Physicians of India, 1999
The cause of stroke in the young remains unknown in 20-50% of the patients. Infections preceding ... more The cause of stroke in the young remains unknown in 20-50% of the patients. Infections preceding stroke have been recently recognised to be an independent risk factor of stroke. Sixty consecutive patients aged 40 years or less presenting with ischaemic completed stroke are taken up for the study. Patients with neurological deficit of less than 24 hours, evidence of haemorrhage on CT scan, infection occurring after the onset of stroke were excluded. Controls consisted of age and sex matched persons residing in the same area. Both the groups were enquired about preceding fever and infections and were examined for evidence of infections. Serum was examined for antibodies against measles, herpes simplex, and Japanese B encephalitis viruses. Cultures were put up from appropriate samples and CSF examined in patients only. Evidence of infection was noted in 26 (43.3%) of patients and 6 controls (p < 0.001). History of fever was elicited in 23 patients and 3 controls while 15 patients we...
The Journal of the Association of Physicians of India, 1990
Two patients with internal carotid disease and normal/hypoplastic vertebro-basilar system present... more Two patients with internal carotid disease and normal/hypoplastic vertebro-basilar system presenting with symptoms of vertebrobasilar insufficiency are presented. The role of associated anomalies of the circle of Willis or major vessels in the pathogenesis of symptoms is highlighted.
The Journal of the Association of Physicians of India, 1995
Of the 220 patients of acute idiopathic demyelinating polyneuritis (AIDP/GBS) seen over a seven y... more Of the 220 patients of acute idiopathic demyelinating polyneuritis (AIDP/GBS) seen over a seven year period, 15 patients (M:F:11:4) had a relapsing course (6.8%). Their ages ranged from 8 yrs to 70 yrs. They had 36 episodes at a variable interval of 3 months to 25 yrs. Relapse rate varied from one to four. Antecedent events were noted during 16 episodes in 9 patients but the triggering factors were varied. Clinical features of individual episodes were similar to the acute monophasic illness, although they differed inseverity from one episode to the other. Autonomic disturbances were rare. Albuminocytological dissociation was observed during 19 of the 24 episodes. Electrophysiological abnormalities were observed during 19 of the 24 episodes. Electrophysiological abnormalities were present in all and were comparable with patients of non-recurrent illness. Sural nerve biopsy in 3 patients showed evidence of demyelination, remyelination, Wallerian degeneration and myelin breakdown but n...
The Journal of the Association of Physicians of India, 1989
A sixty two year old man who presented with tremors of trunk and lower limbs, appearing only on s... more A sixty two year old man who presented with tremors of trunk and lower limbs, appearing only on standing, is reported. The tremor frequency was 14-16 Hz and there was co-contraction of antagonistic muscles. No therapeutic benefit was noted with propranolol, primidone and diazepam. The possible pathogenesis of this rare orthostatic trunkal tremor and its relationship with essential tremor are discussed.
Stroke is a leading cause of deaths, and disabilities in India. Reliable and good quality data on... more Stroke is a leading cause of deaths, and disabilities in India. Reliable and good quality data on epidemiological characteristics of stroke are essential to plan, implement and evaluate stroke prevention and control programmes. A feasibility study was undertaken in Bangalore to examine the possibility of establishing stroke surveillance and to develop methodology for a larger programme. The study adapted WHO STEPs-STROKE methodology to collect data on hospitalized stroke events and fatal stroke events in the city of Bangalore. In STEP I, Information was collected from 1,174 stroke patients in three large hospitals and were followed till discharge and 28 days; outcome was measured as death or disability. Stroke cases fulfilling diagnostic criteria, evaluated by neurologists and CT/MRI confirmed cases were included. Brief information on major risk factors was collected from all stroke patients / family members and from medical records by trained research officers. In STEP II, death re...
A patient with Sturge-Weber-Dimitri disease presented with intractable seizures and progressive i... more A patient with Sturge-Weber-Dimitri disease presented with intractable seizures and progressive intellectual deterioration. There was no facial nevus or focal neurologic abnormality. CT disclosed bilateral calcification in a parieto-occipital gyral pattern. Histopathology of the brain revealed extensive calcification of vessel wall in parieto-occipital cortices.
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Papers by D. Nagaraja
by aniline is studied at room temperature, by steady state, in five different solvents namely acetonitrile (AN), 1,4 dioxane (DX), 1,2 dichloroethane (DCE), tetrahydrofuran (THF) and toluene (TOL), in order to explore various possible quenching mechanisms. The experimental results show a positive deviation in Stern Volmer plots for all solvents. Various parameters for the quenching process are determined by ground state complex, sphere of action static quenching model and finite sink approximation model. The magnitudes of these rate parameters indicate that positive deviation in the Stern–Volmer (SV) plot.
by aniline is studied at room temperature, by steady state, in five different solvents namely acetonitrile (AN), 1,4 dioxane (DX), 1,2 dichloroethane (DCE), tetrahydrofuran (THF) and toluene (TOL), in order to explore various possible quenching mechanisms. The experimental results show a positive deviation in Stern Volmer plots for all solvents. Various parameters for the quenching process are determined by ground state complex, sphere of action static quenching model and finite sink approximation model. The magnitudes of these rate parameters indicate that positive deviation in the Stern–Volmer (SV) plot.