Removal of a potent cyanobacterial hepatotoxin by peat

Microcystins (cyclic heptapeptides), produced by a number of freshwater cyanobacteria, are of health concern in potable water supplies. In this article, the adsorptive removal of microcystin-RR (MCRR) from the aqueous solution by a low-cost adsorbent, peat, was investigated. The BET surface area of peat was found to be 12.134 m2/g. The adsorption process was pH dependent, with maximum adsorption occurring at pH 3. Kinetic studies revealed that the adsorption of MCRR onto peat was a rapid process. The adsorption capacity (Qmax) as revealed by the Langmuir model was found to be 286 μg/g at pH 3. Among various desorption media studied, strong alkali solutions (2 N NaOH) showed the highest desorption (97%). Thus, peat has potential to be used as an adsorbent for the removal of the cyanotoxin, MCRR, from drinking water.

Eccentric target sign in cerebral toxoplasmosis: neuropathological correlate to the imaging feature

Cerebral toxoplasmosis remains one of the most common focal brain lesions in patients with acquired immune deficiency syndrome (AIDS). Diagnosis is a challenge because on cranial imaging it closely mimics central nervous system lymphoma, primary and metastatic central nervous system (CNS) tumors, or other intracranial infections like tuberculoma or abscesses. A magnetic resonance imaging (MRI) feature on postcontrast T1-weighted sequences considered pathognomonic of toxoplasmosis is the "eccentric target sign." The pathological correlate of this imaging sign has been speculative. Herein we correlate the underlying histopathology to the MR feature of eccentric target sign in a patient with autopsy-proven HIV/AIDS-related cerebral toxoplasmosis. The central enhancing core of the target seen on MRI was produced by a leash of inflamed vessels extending down the length of the sulcus that was surrounded by concentric zones of necrosis and a wall composed of histiocytes and proliferating blood vessels, with impaired permeability producing the peripheral enhancing rim.

Teratoma in split cord malformation: an unusual association: a report of two cases with a review of the literature

Split cord malformations (SCM) may be discovered as isolated occult spinal dysraphism or in association with various other overt developmental spinal abnormalities or lesions. However, the occurrence of SCM with intraspinal teratoma is rare. We report 2 cases of teratoma associated with SCM, of which one is intramedullary and the other extradural within meningocele, with a brief review of the literature.

Cryptococcal meningitis: clinical, diagnostic and therapeutic overviews

Cryptococcal meningitis has emerged as a leading cause of infectious morbidity and mortality in patients with AIDS. Among the human immunodeficiency virus (HIV)-seropositive subjects, cryptococcal meningitis is the second most common cause of opportunistic neuro-infection. Current trends are changing due to the marked improvement of quality and length of life produced by highly active antiretroviral therapy (HAART). The introduction of generic HAART in India has resulted in an increase in the number of individuals getting treatment for HIV infection, as the cost of highly active antiretroviral therapy (HAART) has decreased 20- fold. Cryptococcal meningitis occurs in non-HIV patients who are immunodeficient due to diabetes, cancer, solid organ transplants, chemotherapeutic drugs, hematological malignancies etc and rarely in healthy individuals with no obvious predisposing factors. Diagnosis of cryptococcal meningitis is fairly straightforward once the diagnosis is considered in the differential diagnosis of chronic meningitis. Treatment of a patient with cryptococcal infection is a challenge for both the physician and the patient, but rewarding, as many would recover with timely and adequate antifungal therapy.

Co-existing thyrotropin secreting pituitary adenoma and low grade glioma: clinical considerations and literature review

The authors report an extremely rare co-occurrence of a thyrotropin secreting pituitary adenoma and a low grade glioma. A 35-year old patient was initially misdiagnosed and treated as a case of primary hyperthyroidism till he presented with visual symptoms and seizures. On evaluation he was also found to have a right frontal glioma. They discuss the presentation, clinical and diagnostic implications, treatment options and possible molecular pathways which help us understand the molecular biology of such tumor associations. They review literature of 12 previous indexed reports of pituitary tumors associated with various grades of gliomas. Though there are 3 previous reports of functioning pituitary tumors and gliomas, this is the first report of a thyrotropin secreting pituitary adenoma and an associated low grade glioma.

Cerebellar tuberculoma presenting as haematoma--a case report and pathophysiological consideration

Intracranial tuberculoma represents the most common mass lesion in neurotuberculosis. We report an unusual case of tuberculoma with haemorrhage presenting clinically as a cerebellar haemorrhage. Cranial CT scan revealed a peripherally enhancing cerebellar mass with haemorrhage and obstructive hydrocephalus, requiring urgent surgical evacuation of the haematoma. Histopathological examination revealed tuberculoma with features of phlebitis. In view of the pathological evidence of phlebitis in the lesion, it could represent an immune-mediated acute haemorrhagic leucoencephalitis in response to tubercular antigens.

Absence of age-related changes in nigral dopaminergic neurons of Asian Indians: relevance to lower incidence of Parkinson's disease

Age-related loss of melanized nigral neurons reported in the British Caucasians is not observed in Asian Indian, American and French adults. In the Americans, loss of dopaminergic phenotype occurs from midlife, without frank neurodegeneration. Here, we investigated whether nigral dopaminergic neurons in Asian Indians are lost with age or undergo morphological or biochemical dysfunction. Using unbiased stereology we estimated volume, number of melanized, borderline/non-melanized (n=34, 28 gestational weeks to 80 years) and tyrosine hydroxylase (TH)-Nurr1 co-labeled neurons (n=32, 28 gestational weeks to 80 years) in substantia nigra pars compacta. We quantified Nurr1 and TH proteins by immunoblotting (n=18, 28 gestational weeks to 69 years) and apoptotic neurons by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) staining. Nuclear and soma size was estimated by morphometry. There was no age-related decline in volume, neuronal density, neuronal numbers and TH-Nurr1 co-labeled neurons. TH and Nurr1 protein expression remained stable. Lack of TUNEL-TH co-labeled cells confirmed absence of neuronal apoptosis. The neuronal size remained unaltered. Our findings of preserved nigral dopaminergic neurons suggest no age-related loss of nigral function in Asian Indians, unlike the Americans. This may explain the lower incidence of Parkinson's disease in Asian Indians.

Synthesis of 2-(5Z,8Z,11Z,14Z)-Icosa-5,8,11,14-tetraenamidoethyl-d(4) Dihydrogen Phosphate, Tetra-deuterated pAEA

A labile intermediate phospho-anandamide (2-(5Z,8Z,11Z,14Z)-icosa-5,8,11,14-tetraenamidoethyl dihydrogen phosphate, pAEA) has been identified in mouse brain and macrophages, but its precise quantitation was difficult because of its low concentration and chemical instability. We report the synthesis of tetra-deuterated pAEA from 2-aminoethyl dihydrogen phosphate-1,1,2,2-d(4) and (5Z,8Z,11Z,14Z)-2,5-dioxopyrrolidin-1-yl icosa-5,8,11,14-tetraenoate. The compound will be used to quantitate the pAEA necessary for a novel biosynthetic pathway.

Nocardial brain abscess in an immunocompetent host

Nocardial infection of the central nervous system is rare and usually manifests as brain abscess. Here we describe an elderly gentleman who presented with signs and symptoms of an intracranial mass lesion localising to the frontal lobe. Clinical examination and CT scan suggested neoplasia as the probable diagnosis. A biloculated abscess was seen at surgery. Aspiration of the contents and examination of pus revealed Nocardia asteroides . Treatment included total excision and prolonged antibiotic therapy which resulted in an excellent outcome.