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Neeraj Kumar

Publications and source records attributed to Neeraj Kumar.

At least 37 records · Page 2Linked to original sources
PubMed2005

Imaging features of copper deficiency myelopathy: a study of 25 cases.

Acquired copper deficiency presents with a spastic gait and sensory ataxia. Spinal cord magnetic resonance imaging (MRI) in patients with copper deficiency myelopathy may show increased T2 signal, most commonly in the dorsal midline cervical and thoracic cord. These imaging findings may be reversible with normalization of serum copper. The clinical and imaging picture is very similar to the subacute combined degeneration seen in patients with vitamin B12 deficiency. Neuroradiologists should consider this possibility when a long segment of symmetric dorsal spinal cord T2-hyperintensity is identified.

Adult↗
PubMed2005

Role of polyanhydrides as localized drug carriers.

Many drugs that are administered in an unmodified form by conventional systemic routes fail to reach target organs in an effective concentration, or are not effective over a length of time due to a facile metabolism. Various types of targeting delivery systems and devices have been tried over a long period of time to overcome these problems. Targeted delivery or localized drug delivery offers an advantage of reduced body burden and systemic toxicity of the drugs, especially useful for highly toxic drugs like anticancer agents. Local drug delivery via polymer is a simple approach and hypothesized to avoid the above stated problems. Polyanhydrides are a unique class of polymer for drug delivery because some of them demonstrate a near zero order drug release and relatively rapid biodegradation in vivo. Further, the release rate of polyanhydride fabricated device can be altered over a thousand fold by simple changes in the polymer backbone. Hence, these are one of the best-suited polymers for drug delivery, with biodegradability and biocompatibility. The review focuses on the advantages of polyanhydride carriers in localized drug delivery along with their degradability behavior, toxicological profile and role in various disease conditions.

Antineoplastic Agents↗
PubMed2005

Gene networks in hexaploid wheat: interacting quantitative trait loci for grain protein content.

In hexaploid wheat, single-locus and two-locus quantitative trait loci (QTL) analyses for grain protein content (GPC) were conducted using two different mapping populations (PI and PII). Main effect QTLs (M-QTLs), epistatic QTLs (E-QTLs) and QTL x environment interactions (QE, QQE) were detected using two-locus analyses in both the populations. Only a few QTLs were common in both the analyses, and the QTLs and the interactions detected in the two populations differed, suggesting the superiority of two-locus analysis and the need for using several mapping populations for QTL analysis. A sizable proportion of genetic variation for GPC was due to interactions (28.59% and 54.03%), rather than to M-QTL effects (7.24% and 7.22%), which are the only genetic effects often detected in the majority of QTL studies. Even E-QTLs made a marginal contribution to genetic variation (2.68% and 6.04%), thus suggesting that the major part of genetic variation is due to changes in gene networks rather than the presence or absence of specific genes. This is in sharp contrast to the genetic dissection of pre-harvest sprouting tolerance conducted by us earlier, where interaction effects were not substantial, suggesting that the nature of genetic variation also depends on the nature of the trait.

Plant Proteins↗
PubMed2005

Neurologic spectrum of chronic liver failure and basal ganglia T1 hyperintensity on magnetic resonance imaging: probable manganese neurotoxicity.

BACKGROUND: An atypical form of parkinsonism has been described in patients with chronic liver disease, associated with increased T1 signal in the basal ganglia on magnetic resonance imaging. The magnetic resonance imaging signal changes are characteristic of manganese accumulation, which has been neuropathologically confirmed. Manganese neurotoxicity may result in additional neurologic findings besides parkinsonism. OBJECTIVE: To fully characterize patients with chronic central nervous system symptoms and chronic liver failure associated with basal ganglia T1 hyperintensity. DESIGN: Prospective and retrospective case study. SETTING: Mayo Clinic, Rochester, Minn. PARTICIPANTS: Eight patients referred for neurologic evaluation and studied prospectively, and 7 additional retrospectively identified patients who had been examined by Mayo Clinic neurologists. MAIN OUTCOME MEASURES: Neurologic syndromes identified. RESULTS: Three syndromes were recognized in these 15 patients with liver failure and basal ganglia T1 hyperintensity on magnetic resonance imaging: (1) isolated parkinsonism, (2) gait ataxia plus other neurologic findings (ataxia-plus), and (3) cognitive impairment with psychiatric features. All but 1 patient had elevated blood manganese levels. Ammonia levels were normal in most, and the neurologic syndromes did not appear to reflect the well-known toxic-metabolic encephalopathy of liver disease. CONCLUSIONS: Chronic liver failure may result in heterogeneous neurologic syndromes that cut across a variety of liver diseases. We selected cases on the basis of evidence of brain manganese accumulation, and this may be a crucial component of these syndromes. Further studies are necessary to explore this issue.

Adult↗
PubMed2005

Levodopa-dyskinesia incidence by age of Parkinson's disease onset.

We assessed the 5-year risk of levodopa-induced dyskinesias by age of Parkinson's disease (PD) onset in a population-based cohort. The medical records linkage system of the Rochester Epidemiology project was used to identify residents of Olmsted County, Minnesota, with incident PD for the period 1976 through 1990. In this population-based study, the 5-year dyskinesia incidence declined with age. With PD onset after 70 years of age, the incidence was 16%. With onset from 40 to 59 years of age, the incidence was higher at 50%. These incidence data may overestimate the functional importance, because patients with minimal or reversible dyskinesias were counted.

Adult↗
PubMed2005

Clinical feature profile of spinocerebellar ataxia type 1-8 predicts genetically defined subtypes.

An increasing number of genetically defined types of spinocerebellar ataxia (SCA) have been reported in the past decade. Phenotype--genotype correlation studies have suggested a broad overlap between SCA types. The aim of the present study was to identify patterns of clinical features that were likely to distinguish between SCA types and to test the specificity and sensitivity of these signs and symptoms using a Bayesian classifier. In total, 127 patients from 50 families with SCA types 1 to 8 were examined using a worksheet with a panel of 33 symptoms and signs. By computing the probabilities of each trait for each SCA type, we rated the predictive value of each feature for each form of ataxia and then combined the probabilities for the entire panel of traits to construct a Bayesian classifier. Results of this analysis were summarized in a simpler, more operator-based algorithm. Patients with SCA5, SCA6, and SCA8 demonstrated a predominant cerebellar syndrome, whereas patients with SCA1, SCA2, SCA3, SCA4, and SCA7 frequently had clinical features indicating an extracerebellar involvement. The Bayesian classifier predicted the SCA type in 78% of patients with sensitivities between 60 and 100% and specificities between 94 and 98.2%. The highest sensitivity to correctly predict the true SCA type was found for SCA5, SCA7, and SCA8. Sensitivities and specificities found in the present study validate the use of algorithms to help to prioritize specific SCA gene testing, which will help to reduce costs for gene testing.

Age of Onset↗
PubMed2005

Expanding the spectrum of acquired cerebral hemiatrophy.

The authors report a 50-year-old man with progressive left hemispheric atrophy, cognitive decline, infrequent seizures, and spells suggestive of complicated migraine. They discuss the association between migraine and cerebral hemiatrophy and suggest that the spectrum of acquired cerebral hemiatrophy may be broader than what has been commonly recognized.

Atrophy↗
PubMed2005

An unusual presentation of rheumatoid meningitis.

BACKGROUND: Central nervous system involvement in rheumatoid arthritis can rarely occur in the absence of systemic disease. Rheumatoid meningitis has not been reported to present as spells of neurologic dysfunction. PATIENT AND METHODS: The authors describe a woman with a history of well-controlled rheumatoid arthritis who presented with headaches and spells of focal neurological dysfunction. Brain magnetic resonance imaging, brain biopsy, and temporal artery biopsy were required to make the diagnosis of rheumatoid meningitis with arteritis. RESULTS: Neuroimaging revealed abnormal leptomeningeal enhancement. Necrotizing granulomatous inflammation was seen on meningeal and brain biopsy. A temporal artery biopsy showed evidence of arteritis without giant cells. CONCLUSIONS: The possibility of central nervous system involvement by rheumatoid arthritis should be considered in patients with a history of rheumatoid arthritis even in the absence of systemic symptoms. Making the diagnosis may require meningeal and brain biopsy. The condition may be steroid responsive.

Aged↗
PubMed2005

Structure and biological activity of heparinoid.

Heparin is a biogenic anionic charged sulfated polysaccharide that has a range of desired activities including inhibition of tumor metastasis and inhibition of restenosis. However, its clinical use is limited to treating blood-clotting disorders. Anionic macromolecules called heparinoids have been investigated with the objective of developing heparin-like molecules with reduced anti-coagulant activity and selective anti-metastasis and anti-restenosis activity. This mini-review summarizes the synthesis and biological activity of the main synthetic heparinoids reported in the past three decades.

Amino Acids↗
PubMed2005

"Myelodysplasia," myeloneuropathy, and copper deficiency.

We describe a patient with a suspected myelodysplastic syndrome that developed in association with a neurologic disorder resembling subacute combined degeneration but without vitamin B12 deficiency. Ultimately, the hematologic manifestations and the neurologic syndrome were linked to severe copper deficiency. Prompt and complete reversal of the hematologic abnormalities occurred with copper replacement. Serum copper determination should be included in the work-up of patients with anemia and leukopenia of unclear etiology who have associated myeloneuropathy. The hematologic picture can resemble sideroblastic anemia or myelodysplastic syndrome. Hyperzincemia can be an accompanying abnormality even without exogenous zinc ingestion. The reason for the copper deficiency may not be evident.

Biopsy, Needle↗
PubMed2004

Copper deficiency myelopathy produces a clinical picture like subacute combined degeneration.

BACKGROUND: Copper deficiency in ruminants is known to cause an ataxic myelopathy. Copper deficiency as a cause of progressive myelopathy in adults is underrecognized. OBJECTIVE: To describe the clinical, biochemical, electrophysiologic, and imaging characteristics in 13 patients with myelopathy associated with copper deficiency. METHODS: The records of patients with a copper deficiency-associated myelopathy were reviewed. Clinical characteristics, laboratory investigations, and responses to therapeutic intervention were summarized. RESULTS: Thirteen such patients were found, 11 of them in a 15-month period. All patients presented with prominent gait difficulty, reflecting a sensory ataxia due to dorsal column dysfunction and lower limb spasticity. All patients had polyneuropathy. A high or high-normal serum zinc level was seen in 7 of the 11 patients for whom this information was available. Somatosensory evoked potential studies done in eight patients showed impaired conduction in central proprioceptive pathways. Dorsal column signal change on spine MRI was present in three patients. An initial clue to the diagnosis was a very low ceruloplasmin level; further tests of copper metabolism excluded Wilson disease. The cause remained unexplained in most patients. Oral copper supplementation restored normal or near-normal copper levels in 7 of the 12 patients in whom adequate follow-up data were available; parenteral supplementation restored normal level in 3 further patients. Copper supplementation prevented further neurologic deterioration, but the degree of actual improvement was variable. CONCLUSIONS: Unrecognized copper deficiency appears to be a common cause of idiopathic myelopathy in adults. The clinical picture bears striking similarities to the syndrome of subacute combined degeneration associated with vitamin B12 deficiency. Early recognition and copper supplementation may prevent neurologic deterioration.

Adult↗
PubMed2004

Spinal neurosarcoidosis mimicking an idiopathic inflammatory demyelinating syndrome.

BACKGROUND: Intramedullary neurosarcoidosis may be the first and only manifestation of the disease and may mimic an idiopathic inflammatory demyelinating syndrome both clinically and on neuroimaging results. METHODS AND RESULTS: Two patients who were seen initially with a relapsing-remitting neurologic course and a cervical intramedullary lesion on magnetic resonance imaging findings are reported. Both proved to have neurosarcoidosis. A computed axial tomographic scan of the chest showed hilar adenopathy, which provided a clue to the diagnosis. CONCLUSIONS: Symptoms due to an intramedullary cervical lesion can be the first manifestation of neurosarcoidosis. The clinical course can mimic a demyelinating illness. A high index of suspicion and a search for sarcoidosis at extraneural sites are required for an early diagnosis. Steroid treatment is associated with a favorable outcome.

Adult↗
PubMed2004

Copper deficiency myelopathy.

BACKGROUND: In humans, Menkes disease is the well-recognized neurological disorder due to inherited copper deficiency. Myelopathy due to acquired copper deficiency is not a well-recognized entity in humans, although myelopathy due to copper deficiency is well documented in some animal species. PATIENTS: We describe 3 patients who developed a progressive spastic-ataxic gait with proprioceptive deficits. All patients had a severe reduction in serum ceruloplasmin and copper levels. RESULTS: All patients had evidence of posterior column dysfunction clinically and on somatosensory evoked potential studies. Two had a signal change in the posterior column on magnetic resonance imaging of the spinal cord. CONCLUSION: Patients presenting with otherwise unexplained myelopathies should have their serum ceruloplasmin level measured.

Aged↗