Biomedical subjects

Dushyant Purohit

Publications and source records attributed to Dushyant Purohit.

6 recordsLinked to original sources

PubMed2006

Pituicytoma presenting with spontaneous hemorrhage.

Pituicytomas are rare tumors. Previously reported pituicytomas all presented with signs and symptoms relating to mass effect or endocrinological dysfunction. We report a 47 year old man who presented with sudden, severe headache and was found to have a hemorrhagic suprasellar mass with hemorrhage into the third ventricle. A mass arising from the pituitary stalk was found at surgery, and thorough pathological analysis revealed a pituicytoma. Pituicytoma should be considered in the differential diagnosis of a hemorrhagic suprasellar mass.

Adult↗

PubMed2004

Autonomic failure as the initial presentation of Parkinson disease and dementia with Lewy bodies.

The authors report the clinical and postmortem neuropathologic findings of two patients, one with Parkinson disease (PD) and one with dementia with Lewy bodies (DLB), both of whom initially sought treatment for isolated autonomic failure. These cases suggest that neurodegeneration in PD and DLB may begin outside the CNS in autonomic postganglionic neurons, a finding with potential diagnostic and therapeutic implications.

Aged↗

PubMed2003

Caspase gene expression in the brain as a function of the clinical progression of Alzheimer disease.

BACKGROUND: Caspase gene expression has previously been reported in terminal Alzheimer disease (AD) brain, but, currently, little is known about the temporal pattern of caspase gene expression relative to the onset and clinical progression of AD. OBJECTIVE: To derive a profile of caspase gene expression and proapoptotic indexes as a function of the clinical and neuropathologic progression of AD dementia. SETTING AND PATIENTS: Postmortem survey of nursing home patients characterized clinically by Clinical Dementia Rating (CDR) and neuropathologically by Consortium to Establish a Registry for Alzheimer's Disease criteria. DESIGN AND OUTCOME MEASURES: To assess messenger RNA expression of caspase-1, -2L, -2S, -3, -5, -6, -7, -8, and -9; apoptotic cell death by TUNEL assay; and poly (ADP-ribose) polymerase cleavage in postmortem brain tissue samples from cognitively normal (CDR 0), high risk of developing AD dementia (CDR 0.5), and severe dementia (CDR 5) cases. RESULTS: Compared with CDR 0 cases, elevated messenger RNA expression of caspase-1 and caspase-7 in the entorhinal cortex of CDR 0.5 cases coincided with increased poly (ADP-ribose) polymerase cleavage but not apoptotic cell injury. In the entorhinal cortex of CDR 5 cases, we found elevation of caspase-1, -2L, -3, -5, -6, -7, -8, and -9 and a greater than 4-fold increase in TUNEL-positive cells. Caspase messenger RNA expression was closely associated with neurofibrillary tangle and, to a lesser extent, neuritic plaque density. CONCLUSIONS: Proapoptotic mechanisms may be at play early in the onset of AD (before overt signs of apoptosis) and may be a conditional factor for later apoptotic cell injury or death. These data have relevance to potential therapeutic interventions for AD using selective caspase inhibitors.

Aged↗

PubMed2003

CCR1 is an early and specific marker of Alzheimer's disease.

Chemokines are a diverse group of small proteins that effect cell signaling by binding to G-protein-coupled, seven-trans-membrane receptors. Our group had found previously that the chemokine receptor CCR1 was present in neurons and dystrophic processes in a small sample of Alzheimer's disease cases. This expanded immunohistochemical study shows that the number of CCR1-positive plaque-like structures in the hippocampus and entorhinal cortex is highly correlated to dementia state as measured by the clinical dementia rating score. CCR1 immunoreactivity is found in dystrophic, neurofilament-positive, synaptophysin-negative neurites that are associated with senile plaques containing amyloid beta peptides of the 1-42 species (Abeta42). CCR1 was not, however, associated with diffuse deposits of Abeta42. There was limited expression of CCR1 in neurofibrillary tangle-bearing neuritic processes. Astrocytes and microglia were typically negative for CCR1. Human brains from age-matched, nondemented individuals rarely displayed either CCR1 or Abeta42 immunoreactivity. Seven other types of dementing neurodegenerative diseases were examined, and all failed to demonstrate CCR1 immunopositivity unless Abeta42-positive plaques were also present. Thus, neuronal CCR1 is not a generalized marker of neurodegeneration. Rather, it appears to be part of the neuroimmune response to Abeta42-positive neuritic plaques.

Alzheimer Disease↗

PubMed2002

Palliative and aggressive end-of-life care for patients with dementia.

OBJECTIVES: The goals of this study were to establish the frequency of palliative and aggressive treatment measures among patients with and without dementia during the last six months of life, to identify relationships between the severity of dementia and aggressive and palliative care, and to determine whether treatment patterns have changed over time. METHODS: Antemortem data for 279 patients with dementia and 24 control patients who were brought for autopsy in chronic care facilities between 1985 and 2000 were reviewed. The severity of dementia was defined by scores on the Clinical Dementia Rating scale. Data on use of systemic antibiotics (designated as an aggressive treatment measure) and on use of narcotic and nonnarcotic pain medications and nasal oxygen (defined as palliative measures) were collected from medical charts. RESULTS: Fifty-three percent of the patients with dementia and 46 percent of those without dementia had received systemic antibiotics. Fourteen percent of the patients with dementia and 38 percent of those without dementia had received narcotic pain medications. The prevalence of aggressive and palliative measures did not vary significantly with the severity of dementia. Eleven percent of the patients with dementia who died between 1991 and 1995 and 18 percent of those who died between 1996 and 2000 had received narcotic pain medications in the last six months of their lives. CONCLUSIONS: Use of systemic antibiotics is prevalent in the treatment of patients with end-stage dementia, despite the limited utility and discomfort associated with the use of these agents. That patients with severe dementia and those with milder cognitive impairment received similar treatment may be contrary to good clinical practice, given the poor prognosis of patients with severe dementia.

Aged↗

PubMedDate not supplied

Parkinson's disease without expected neuropathologic abnormality.

A case is reported of an initially 78-year-old man whose presentation and course, closely followed over 10 years by an academic neurologist, were consistent with classic idiopathic Parkinson's disease (PD), including unilateral onset, obvious cogwheeling, and a very good prolonged response to levodopa/carbidopa (LD/CD). Yet at autopsy, there was no neuronal loss in the substantia nigra nor were there any Lewy bodies or immunochemical evidence of alpha synuclein in the multiple brain structures studied. This case does not support the hypothesis that the use of LD/CD is toxic to the substantia nigra in people. This patient had been on traditional doses of LD/CD for approximately 10 years, yet the number of cells in the substantia nigra was well within the normal range at autopsy. These findings are not unique, but point out the need to explain the occurrence of typical PD symptoms and course in the absence of any PD-related neuropathologic changes.

Aged↗