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Biomedical subjects

P K Pal

Publications and source records attributed to P K Pal.

At least 19 recordsLinked to original sources
PubMed2006

Diabetic nonketotic hyperosmolar state: interesting imaging observations in 2 patients with involuntary movements and seizures.

We report two patients of diabetic nonketotic hyperosmolar state presenting acutely with "self-limiting hemichorea - hemiballismus" and "generalized convulsive status epilepticus". CT scan in both the patients revealed a hyperdense nonenhancing basal ganglia. Magnetic resonance imaging brain of patient 1 showed it to be hyperintense on T1W image and iso-hyper intense on T2W image, minimally enhancing with contrast injection.

Dyskinesias↗
PubMed2005

Management of neurodegenerative disorders: Parkinson's disease and Alzheimer's disease.

Neurodegenerative disorders result from premature progressive degeneration of specific neurons, and manifest as diseases or syndromes with varied combinations of cognitive, motor, sensory and autonomic dysfunctions. The management involves pharmacotherapy as well as non-pharmacological measures and also to lessen the burden of the care-givers. The medications available for medical treatment are: Levodopa, dopamine agonists, amantadine, anticholinergics, enzyme inhibitors, etc. Advanced Parkinson's disease is concerned with management of motor complications and non-motor complications. Recently surgical treatment is a great option for managing motor complication. Orthostatic hypotension, gait distiurbances, emotional and psychiatric problems, sleep disturbances can be managed and had been discussed in brief. Currently there is no medication available for the cure of Alzheimer's disease. The specific medications claimed to improve patient's well being and cognition include cholinesterase inhibitors, N-methyl-D-aspartate receptor antagonist, anti-oxidants, and anti-amyloid therapy. While medical and surgical treatments for Parkinson's disease have revolutionised the management, still drug therapy for Alzheimer's disease is dismal.

Alzheimer Disease↗
PubMed2004

Nocturnal sleep disturbances and daytime dysfunction in patients with Parkinson's disease and in their caregivers.

BACKGROUND: The role of aging, disease, medications, and mood disturbances in sleep disturbances (SD) in patients with Parkinson's disease (PD) is poorly understood, and the impact of SD on the quality of life of their caregivers (CG) largely undocumented. OBJECTIVES: To evaluate the pattern and determinants of disturbed sleep in PD patients complaining of SD, and in their primary CG. METHODS: A prospective evaluation of 40 non-demented patients with PD complaining of SD and 23 of their primary CG (all were spouses) was conducted using Pittsburgh Sleep Quality Index, Zung's self-rating depression and anxiety scales, Parkinson's Impact Scale (PIMS) (only for PD), and an additional sleep questionnaire. RESULTS: Eighty-four percent of patients were 'poor sleepers' with global sleep scores (GLSc) > 5. Other abnormalities were: excessive daytime sleepiness-57.5%, excessive daytime fatigue-72.5%, depression-51.5%, anxiety-63.1%, and abnormal PIMS score-83.8%. There was no correlation between the degree of sleep dysfunction and the age, severity, duration of PD or its treatment. Several component sleep scores correlated with anxiety scores, PIMS score with depression, and, subjects with GLSc > or = 10 had higher mean anxiety index. Daytime dysfunction (97.5%) was mainly associated with reduced enthusiasm, rather than excessive sleepiness. Among CG, 40% had a GLSc > 5, 21% had depression, and 10.5% had anxiety. Their depression, anxiety and sleep scores correlated with those of their spouses. CONCLUSIONS: PD patients with significant SD may represent a subset of patients with early, progressive degeneration of sleep centres, rather than an enhanced aging process. They are more susceptible mood disturbances, which correlate with the severity of sleep dysfunction. Sleep and mood disturbances also adversely affect the quality of life of spousal caregivers.

Adult↗
PubMed2003

Clinical features, assessment and treatment of essential tremor.

Essential tremor is the most common of the movement disorders, being 20 times more common than Parkinson's Disease. It is characterised by postural and kinetic tremor which maximally affects the hands. It can be assessed by physiological techniques, subjective clinical methods, objective clinical methods and handicap/disability scales. Accelerometry, spirography and handwriting assessment, volumetry and handicap/disability questionnaires are commonly used methods. Primidone and propranolol are the first-line drugs. Several second-line drugs have been identified. Surgical techniques include lesioning or stimulation of the ventral lateral thalamus. Alcohol and botulinum toxin A are found to reduce tremor amplitude as well.

Essential Tremor↗
PubMed2002

Moisture sorption characteristics of dudh churpi, a traditional milk product in India.

The sorption isotherms of dudh churpi, a shelf-stable traditional milk product in India, determined at 15, 25, 35 and 45 degrees C, were typical type II sigmoidal according to the BDDT (Brunauer-Deming-Deming-Teller) classification. Nine equations, namely Bradley, Henderson, Iglesias and Chirife, Khun, Mizrahi, GAB (Guggenheim-Anderson-de Boer), modified Mizrahi, Oswin and Caurie were fitted to the sorption data. Caurie's equation was found to be suited best to predict equilibrium moisture content of dudh churpi. Monolayer value, density of sorbed water, number of monolayers and area of adsorbent decreased with the increase in temperature.

Adsorption↗
PubMed2001

Positron emission tomography of dopamine pathways in familial Parkinsonian syndromes.

Positron emission tomography (PET) scan is considered to be the most useful tool with which to assess the integrity of nigrostriatal function in the living brain. Recently, different genetic defects have been associated with a variety of familial parkinsonian syndromes, the clinical phenotypes of which have varying degrees of similarities to idiopathic parkinsonism (IP), (sporadic Parkinson's disease). This review summarizes: (1) the PET scan findings (fluorodopa uptake and raclopride binding) in both familial parkinsonian syndromes and IP; and (2) the similarities and differences of the clinical and PET features between familial parkinsonian syndromes and IP. This analysis demonstrates that more similarities than differences exist in PET scan findings in the different familial parkinsonian syndromes with the exception of pallido-ponto-nigral degeneration (PPND), that is perhaps best considered as multisystem degeneration. As a result of this analysis, we believe that while different genetic defects may underlie different mechanisms of nigrostriatal degeneration, the final pattern of nigrostriatal dysfunction is essentially similar to that of IP. 'Parkinson's disease', therefore, may not represent a single disease entity, but rather the final manifestation of different pathogenetic mechanisms-mediated by genetic or environmental factors, or an interaction of genetic and environmental factors.

Dopamine↗
PubMed2000

Botulinum toxin A as treatment for drooling saliva in PD.

The authors evaluated intraparotid injections of botulinum toxin A in reducing salivary secretions and drooling in nine patients with PD. There was a marked objective reduction in secretion, and two thirds of the patients had subjective improvement in drooling. No side effects were observed. The authors conclude that botulinum toxin A promises to be a simple and effective treatment for the common problem of drooling saliva in chronic neurologic disease.

Aged↗
PubMed2000

Evidence for impaired presynaptic dopamine function in parkinsonian patients with motor fluctuations.

We used [18F]6-fluorodopa (FD) positron emission tomography (PET) to examine the severity of nigrostriatal dopaminergic dysfunction in 67 patients with Idiopathic Parkinsonism (IP), 52 with fluctuations and 15 with a stable response to levodopa. FD uptake (Ki) was reduced by 12% in the caudate (p = 0.08) and by 28% in the putamen (p = 0.0004) of patients with fluctuations compared to those with a stable response. However, there was considerable overlap of FD Ki values between the two groups. The fluctuators had a longer symptom duration (11.6 +/- 5.7 years) than the patients with a stable response to levodopa (4.3 +/- 2.4 years; p < 0.0001) and the age of onset of symptoms was earlier in the fluctuators (43.9 +/- 8.9 versus 54.1 +/- 10.4; p = 0.0004). Similar reductions in FD Ki in the fluctuators persisted following adjustment for these variables (7.5% in the caudate and 26% in the putamen; p = n.s. and 0.007, respectively). When smaller groups (n = 15 each) were matched for duration of symptoms, the reduction in caudate Ki in the fluctuators was only 1.9% (p = n.s.), but there was still a 24% reduction in putamen Ki (p = 0.05). These findings suggest that fluctuators and non-fluctuators may differ in the severity of their nigrostriatal damage and provide modest support for the hypothesis that fluctuations may in part reflect altered "buffering" capacity of dopaminergic nerve terminals. However, the considerable overlap between groups suggests that other factors such as altered postsynaptic mechanisms and/or increased turnover of dopamine may make a substantial contribution to the development of motor fluctuations.

Antiparkinson Agents↗
PubMed2000

Post-traumatic cervical dystonia: a distinct entity?

BACKGROUND/OBJECTIVE: The incidence of head/neck trauma preceding cervical dystonia (CD) has been reported to be 5-21%. There are few reports comparing the clinical characteristics of patients with and without a history of injury. Our aim was to compare the clinical characteristics of idiopathic CD (CD-I) to those with onset precipitated by trauma (CD-T). METHODS: We evaluated 114 consecutive patients with CD over a 9-month period. All patients were interviewed using a detailed questionnaire and had a neurological examination. Their clinical charts were also reviewed. RESULTS: Fourteen patients (12%) had mild head/neck injury within a year preceding the onset of CD. Between the two groups (CD-I and CD-T), the gender distribution (F:M of 3:2), family history of movement disorders (32% vs. 29%), the prevalence of gestes antagonistes (65% vs. 64%), and response to botulinum toxin were similar. There were non-specific trends, including an earlier age of onset (mean ages 43.3 vs. 37.6), higher prevalence of neck pain (86% vs. 100%), head tremor (67% vs. 79%), and dystonia in other body parts (23% vs. 36%) in CD-T. CONCLUSIONS: CD-I and CD-T are clinically similar. Trauma may be a triggering factor in CD but this was only supported by non-significant trends in its earlier age of onset.

Adult↗
PubMed2000

Long term outcome of unilateral pallidotomy: follow up of 15 patients for 3 years.

OBJECTIVES: With the advent of new antiparkinsonian drug therapy and promising results from subthalamic and pallidal stimulation, this study evaluated the long term efficacy of unilateral pallidotomy, a technique which has gained popularity over the past decade for the management of advanced Parkinson's disease. METHODS: The 15 patients reported here are part of the original cohort of 24 patients who underwent posteroventral pallidotomy for motor fluctuations and disabling dyskinesias 3 years ago as part of a prospective study. Evaluation scales included the unified Parkinson's disease rating scale, the Goetz dyskinesia scale, and the Purdue pegboard test. RESULTS: When compared with the prepallidotomy scores, the reduction in the limb dyskinesias and off state tremor scores persisted on the side contralateral to pallidotomy at the end of 3 years (dyskinesias were reduced by 64% (p<0.01) and tremor by 63% (p<0.05). Other measures tended to deteriorate. The dosage of antiparkinsonian medications did not change significantly from 3 months prepallidotomy to 3 years postpallidotomy. CONCLUSIONS: Although unilateral pallidotomy is useful in controlling the contralateral dyskinesias and tremor 3 years after surgery, all other early benefits disappear and activities of daily living continue to worsen.

Activities of Daily Living↗
PubMed2000

In vivo positron emission tomographic evidence for compensatory changes in presynaptic dopaminergic nerve terminals in Parkinson's disease.

Clinical symptoms of Parkinson's disease (PD) do not manifest until dopamine (DA) neuronal loss reaches a symptomatic threshold. To explore the mechanisms of functional compensation that occur in presynaptic DA nerve terminals in PD, we compared striatal positron emission tomographic (PET) measurements by using [11C]dihydrotetrabenazine ([11C]DTBZ; labeling the vesicular monoamine transporter type 2), [11C]methylphenidate (labeling the plasma membrane DA transporter), and [18F]dopa (reflecting synthesis and storage of DA). Three consecutive PET scans were performed in three-dimensional mode by using each tracer on 35 patients and 16 age-matched, normal controls. PET measurements by the three tracers were compared between subgroups of earlier and later stages of PD, between drug-naive and drug-treated subgroups of PD, and between subregions of the parkinsonian striatum. The quantitative relationships of [18F]dopa and [11]DTBZ, and of [11C]methylphenidate and [11C]DTBZ, were compared between the PD and the normal control subjects. We found that [18F]dopa Ki was reduced less than the binding potential (Bmax/Kd) for [11C]DTBZ in the parkinsonian striatum, whereas the [11C]methylphenidate binding potential was reduced more than [11C]DTBZ binding potential. These observations suggest that the activity of aromatic L-amino acid decarboxylase is up-regulated, whereas the plasma membrane DA transporter is down-regulated in the striatum of patients with PD.

Aged↗
PubMed2000

Head tremor in cervical dystonia.

OBJECTIVE: To compare the clinical characteristics, natural history, and therapeutic outcome of patients with cervical dystonia (CD) with head tremor (HT+) and without head tremor (HT-). METHODS: We prospectively evaluated 114 consecutive patients of CD over a 9-month period with a detailed questionnaire. Chi-square and t-tests were employed for statistical analysis. RESULTS: Seventy-eight (68.4%) patients had head tremor and 27 of them (34.6%) had tremor as one of the first symptoms. Age at onset of symptoms were similar in HT+ and HT- groups; however there was a higher prevalence in women in the former group (66.7% vs. 41.7%; p=0.01). HT+ patients had more frequent positive family history of essential-like hand/head tremor (21.8% vs. 5.5%; p<0.05), associated neck pain (92.3% vs. 77.8%: p<0.05), and essential-like hand tremor (40% vs. 8.3%; p<0.001). They also appeared to have more frequent history of preceding head/neck trauma (14.1% vs. 8.3%), frequent head rotation (88.5% vs. 69.4%) and antecollis (12.8% vs. 5.5%) but less often head tilt (37.2% vs. 47.2%) and gestes antagonistes (60.2% vs. 75%) than the HT- patients; however these differences were not statistically significant. The frequency of prior psychiatric illnesses, the incidence of dystonias in other parts of the body, frequency of retrocollis and shoulder elevation, and spontaneous remission were similar in the two groups. CONCLUSION: Head tremor is common in CD and is more commonly associated with hand tremor and family history of tremor or other movement disorders. This supports a possible genetic association between CD and essential tremor (ET). Linkage studies are required to evaluate the genetic association between CD and ET.

Adult↗
PubMed1999

Clinical and electrophysiological studies in vincristine induced neuropathy.

Eighteen patients of lymphoma, treated with vincristine (VCR) were assessed clinically and electrophysiologically before and for 3 months after therapy. The earliest evidence of neuropathy was impaired ankle jerk (around 2 weeks) and the earliest symptom was paraesthesia (by 4-5 weeks). At the end of the study, all the patients had absent ankle jerks and 75% had sensory symptoms and/or signs, the most frequent being impaired vibration sensation (62.5%). Motor abnormalities were much less common (18.7%) and constipation (62.5%) was the only autonomic manifestation. Concentric needle electromyography showed evidence of denervation (46.7%), especially in the small muscles of hand. Conduction studies showed prolonged mean distal latencies, decreased mean amplitudes of compound muscle action potentials, with almost unchanged conduction velocities. However, no conduction block was noted and F-wave studies were normal. During early weeks, in spite of impaired absent ankle jerks, H reflex was elicitable in the majority. However, later 56.2% had absent H reflex. The present study concludes that vincristine produces a distal symmetrical sensorimotor neuropathy, predominantly involving the large diameter fibers in the early stages. Electrophysiological studies characterize it as a distal axonopathy. However it is dependent on the dose of VCR and the duration of therapy: though in the usual doses it does produce neuropathy, it is rarely disabling in the early months.

Adolescent↗
PubMed1999

Early onset cerebellar ataxia with retained tendon reflexes (EOCA) and olivopontocerebellar atrophy (OPCA): a computed tomographic study.

Computed tomographic (CT) studies in olivopontocerebellar atrophies (OPCA) and 'early onset cerebellar ataxia with retained tendon reflexes (EOCA)' are few and vary widely in methodology and criteria for cerebellar and brainstem atrophy. In this prospective study, CT scan observations on 26 patients (EOCA-11, OPCA-15) were compared with 31 controls using qualitative and quantitative assessment of cisterns, ventricles and atrophy of brain. Vermian and/or cerebellar hemispheric (predominantly anterior) atrophy was present in 80.8% and both were equally common. Cerebral cortical atrophy (26.9%) and leukoariosis (15.4%) were less frequently seen. Statistically significant atrophy of pons, brachium pontis, cerebellum and midbrain was noted in patient group. No significant differences were observed between EOCA and OPCA groups. Evidence of atrophy did not correlate with either the duration of illness or the severity of cerebellar ataxia in both the groups. The severity of brainstem atrophy in 14 patients with and 12 patients without abnormal brainstem auditory evoked response did not differ significantly. This study highlights the methodology of CT evaluation for brainstem and cerebellar atrophy, draws attention to cerebral atrophy and emphasizes the lack of significant differences in CT morphology between OPCA and EOCA patients.

Adolescent↗
PubMed1994

An outbreak of viral hepatitis in a housing complex of north Calcutta.

In a housing complex of North Calcutta, a sudden outbreak of hepatitis occurred between September 1988 and January 1989. Of 620 residents, 8.5 per cent were affected. Majority of the cases occurred among the adult population and the case fatality rate was 3.8 per cent. The epidemic was common source with peak incidence in the month of November. The source of infection was most likely drinking water supplied by the Municipal Corporation which was found to be contaminated by faecal coli. Epidemic was suspected to be caused by enterically transmitted Non A Non B hepatitis virus as the serological testing of all 18 blood samples were negative for anti-HAVIgM titre and only one sample was positive for HBsAg.

Adolescent↗
PubMed1993

Proton liberation in the pre-steady state phase of creatine kinase.

Numerous stereochemical and kinetic investigations on the reaction pathway of creatine kinase (CK) suggest that this enzymic reaction proceeds via direct in-line transfer of phosphate between participating substrates and to date there has been no chemical evidence for any plausible intermediate between enzyme-substrate and enzyme-product complexes. By following the absorption pattern of a pH sensitive dye (o-cresol sulphonaphthalein) in a stopped flow module we have studied transient pH changes in the backward reaction of CK. While the rapid mixing of ADP and CK gives no pH transient, that of phosphocreatine (PCr) and CK gives H+ liberation with kapp of 62.8 sec-1. The magnitude of proton release is one H+ per monomer of CK. Mixing of PCr+CK with ADP does not give any detectable pH transient and the reaction immediately proceeds to steady phase. The mixing of ADP+CK with PCr again gives a release of 1.2 H+ per monomer of CK with kapp of around 67.2 sec-1 before the reaction proceeds to steady phase where there is absorption of one H+ per ADP transphosphorylated. The results obtained, therefore, indicate the involvement of proton deficient E.PCr and E.ADP.PCr complexes in the pathway of CK.

Adenosine Diphosphate↗
PubMed1992

The AMP-binding domain on adenylate kinase. Evidence for a conformational change during binary-to-ternary complex formation via photoaffinity labeling analyses.

The topological location of the nucleotide substrate binding environments on adenylate kinase has been explored with the fluorescent molecule [4-benzoyl]benzoyl-1-amidofluorescein (BzAF) and the nucleotide analog 3'-O-[4-benzoyl]benzoyl-ATP (BzATP), which are site-directed photoaffinity probes that bind covalently at the individual nucleotide sites. The MgBzATP substituted for MgATP as a substrate for this enzyme, whereas BzAF, which is neither a substrate nor a nucleotide, behaved as a competitive inhibitor for each nucleotide site independently. BzAF could be directed specifically to either of the nucleotide sites by near saturation of the second site with its natural nucleotide substrate. Using this second site blocking approach, each nucleotide site, in turn, could be protected competitively from BzAF-induced photoinhibition by the presence of its natural substrate. This strategy showed that under photolysis, the Kd(BzAF) of 0.1 mM (for the MgATP site) and 0.2 mM (for the AMP site) were nearly identical with the Km(app) values determined for MgATP and AMP, respectively. Pseudo first-order photolysis kinetics with [3H]BzAF revealed covalent binding stoichiometries for full inhibition of 1 mol of probe/mol of enzyme at either site. Thus, we prepared the binary complex ([3H]BzAF-enzyme) by photo-labeling the MgATP site-blocked enzyme with [3H]BzAf to 1:1 molar stoichiometry. Tryptic digestion followed by partial sequencing of the [3H]BzAF-labeled enzyme disclosed that BzAF was bound specifically within the peptide span Gly64-->Arg77. This amino acid domain therefore probably constitutes the neighborhood identifiable with AMP binding. Furthermore, we also achieved double photocovalent labeling of adenylate kinase with both photoprobes, by first cross-linking with approximately 1 mol of MgBzATP, followed by approximately 0.9 mol of [3H]BzAF, thus generating a ternary covalent complex. Comparison of the fluorescence of the binary species and the ternary (BzATP-enzyme-[3H]BzAF) complex revealed altered fluorescence emission profiles, which could indicate that a conformational change occurs during formation of the ternary (or transition state) complex.

Adenosine Monophosphate↗