Hydrothermally functionalized biocompatible nitrogen doped graphene nanosheet based biomimetic platforms for nitric oxide detection.

Hydrothermal synthesis of nanocomposites is of significant importance, as it affords facile, biocompatible, nontoxic, and economic fabrication. Herein, we report a hitherto unexplored cytocompatible and reusable biomimetic electrochemical sensor based on pyridyl porphyrin functionalized nitrogen doped graphene nanosheets. The porphyrin functionalized nitrogen doped graphene nanosheets (PFNGS) were prepared by a low temperature hydrothermal method via non-covalent strategies with a minimal impact on their physicochemical properties. Owing to their exceptional attributes like operational ease, low cost, portability, and sensitivity, the as-synthesized PFNGS, formed by π-π interactions, were employed for sensing nitric oxide (NO), which is a key regulator of diverse biological processes. Compared to porphyrin and nitrogen doped graphene nanosheets alone, PFNGS exhibited exceptional sensitivity (3.6191 µA µM-1) and remarkable electrocatalytic properties (0.61 V). This clearly outperforms the previously reported modified electrode materials for the electrochemical detection of NO. Cyclic voltammetry (CV) data also suggested that the PFNGS modified electrode possessed an increased reactive surface area, which results in an increase in the number of reactive sites and low charge transfer resistance. These results also demonstrated that the PFNGS modified electrode showed high stability and reproducibility, the limit of detection (LOD) (S/N = 3) of which was estimated to be 1 nM. Our PFNGS were found to be highly biocompatible and could also detect NO released from macrophage cells. This blend of biocompatibility, electrode stability, electrocatalytic activity along with enhanced sensitivity and selectivity makes PFNGS a powerful and reliable nanomaterial for various biomedical applications in complex biological systems.

A rare case of reversible acquired AA-type renal amyloidosis in a chronic filariasis patient receiving antifilarial therapy.

Lymphatic filariasis is a major health problem in India with a large number of patients tending to be asymptomatic. In the Southeast and South Asian regions, Wuchereria bancrofti is the most prevalent parasite, causing filariasis in 99.4% of cases. While kidney involvement is a rare event in chronic filariasis, this case is unique because AA-type renal amyloidosis occurs in chronic W. bancrofti infection. We present here a unique case of lymphatic filariasis. The patient, a 25-year-old male who was previously diagnosed with right lower limb filarial lymphedema and had undergone lymphovenous anastomosis, was admitted for evaluation of persistent nephrotic-range proteinuria. Autoimmune markers in the form of anti-nuclear antibodies, anti-double-stranded DNA and anti-neutrophil cytoplasmic antibody were negative; C3 was normal. Urine analysis revealed inactive sediment with moderate proteinuria. Both serum and urine electrophoresis were negative for paraproteins and bone marrow aspirate and biopsy were normal. Evidence of active filarial infection was established on the basis of microfilariae in the peripheral smear and a positive W. bancrofti antigen test. Kidney biopsy revealed renal amyloidosis when stained with Congo red and anti-AA immunostain. The patient's proteinuria improved on conservative management with angiotensin-converting enzyme inhibitors and a course of antifilarial drugs. His proteinuria returned to <1 g/24 h with normalization of renal function and no significant proteinuria on periodic follow-up at 6-month and 1-year intervals. Repeat kidney biopsy after 1.5 years showed regression of amyloidosis. Repeat demonstration of filarial antigen and microfilariae in the peripheral smear were negative on multiple occasions during the follow-up period. Although various chronic infections can lead to secondary renal amyloidosis, this is the first case reported in world literature where secondary amyloidosis developed as a complication of chronic filarial infection due to W. bancrofti. This is probably also the first case reported in world literature where renal amyloidosis has an etiological association with W. bancrofti infection and where patient symptoms improved with antifilarial and antiproteinuric management.

A series report of autoimmune hypothyroidism associated with Hashimoto's encephalopathy: an under diagnosed clinical entity with good prognosis.

Thyroid dysfunctions may be accompanied by numerous neurological and psychiatric disorders. The most well-known is cognitive impairment and depression in hypothyroid patients, as well as an increased risk of cerebrovascular accidents. A separate, although a rare entity, is Hashimoto's encephalopathy. Unlike encephalopathy associated with other conditions, management in Hashimoto's encephalopathy highly responds to steroid treatment and may be associated with normal thyroid profile at presentation. Hashimoto's encephalopathy, while rare, may have been under-recognised since its clinical presentation overlaps several more common disorders, such as depression, seizures or anxiety. We present two cases of hypothyroidism with peculiar presentation. The first case has rapidly progressive neurological dysfunction, normal thyroid function at presentation, normal MRI finding and responds to steroid treatment. The second case has a subacute progressive neurological deterioration with elevated thyroid-stimulating hormone titre at presentation. Both these cases are known hypothyroidism on regular thyroxin replacement therapy with elevated anti-thyroid peroxidase antibodies. We conclude that Hashimoto's encephalopathy can present with a wide spectrum of neurological illnesses in the setting of hypothyroidism. Thyroid status may vary from hypothyroid, normothyroid to even hyperthyroid. This condition usually has an abnormal electroencephalography (EEG) background and usually responds to high dose steroids.