Hydrogels: from controlled release to pH-responsive drug delivery

Hydrogels are one of the upcoming classes of polymer-based controlled-release drug delivery systems. Besides exhibiting swelling-controlled drug release, hydrogels also show stimuli-responsive changes in their structural network and hence, the drug release. Because of large variations in physiological pH at various body sites in normal as well as pathological conditions, pH-responsive polymeric networks have been extensively studied. This review highlights the use of hydrogels (a class of polymeric systems) in controlled drug delivery, and their application in stimuli-responsive, especially pH-responsive, drug release.     

Pre-operative embolization of auricular arteriovenous fistula

Treatment of auricular arteriovenous fistula (AVF) is a challenge with surgery being the preferred option until now. We present three cases of auricular AVFs who underwent pre-operative embolization and its outcome on surgery. Three patients were diagnosed to have auricular AVF by angiography. All three patients underwent pre-operative embolization with n-butyl 2-cyanoacrylate after which they underwent surgical resection of the AVF. Pre-operative embolization resulted in significant devascularization of the AVF thus leading to near bloodless and clean surgery. Pre-operative embolization of auricular AVFs is a good treatment option, leading to significantly reduced blood loss during surgical excision.     

Prospective comparative study of patients with culture proven and high suspicion of adult onset septic arthritis

OBJECTIVE: To investigate whether patients with acute septic arthritis (SA) diagnosed by positive synovial fluid (SF) culture (Newman grade A) have different clinical and serological features from those with sterile SF in whom there is nonetheless a high suspicion of SA (Newman grades B and C). PATIENTS AND METHODS: A prospective 12 month multicentre hospital based study of adult patients with SA recruited 47 patients with culture positive SA and 35 patients with clinically suspected SA but sterile SF. RESULTS: Patient demography, clinical and laboratory features at presentation were similar irrespective of the underlying diagnosis, SF culture, and the presence of prosthetic joints. Medical and surgical treatment and outcome were comparable in the two patient groups. Patients with both suspected and proven SA were more likely to be from the more socially deprived areas of our community (p<0.0001). CONCLUSION: Patients in whom there is a high clinical suspicion of SA are comparable to those patients with SA with a positive SF culture and have similar morbidity and mortality on follow up. Therefore, if clinical suspicion of SA is high then it is correct to treat as SA in the absence of bacterial proof.     

Sertraline-induced hypomania: a genuine side-effect

OBJECTIVE: Antidepressants including selective serotonin reuptake inhibitor (SSRI)-associated mania or hypomania has been well documented in the literature but these patients with switch have either mood disorders or various risk factors for bipolar disorder. This case report examines SSRI-induced hypomania in a patient with dissociative disorder and highlights hypomania as a genuine side-effect of sertraline rather than a switch. METHOD: A 23-year-old female patient with dissociative disorder has been described. RESULTS: Hypomanic symptoms emerged during treatment with sertraline at the dose of 50 mg/day after 3-4 days of initiation of therapy and had complete recovery within 7 days after stopping sertraline. CONCLUSION: In the absence of risk factors for manic switch, sertraline-induced hypomania may be a true side-effect of drug.     

Dual action antidepressants and some important considerations

OBJECTIVE: To review controlled studies of long-term treatment and their side-effects with newer dual action antidepressants following an acute episode of major depression. METHOD: A literature review (MedLine) was undertaken and references were selected for their relevance and methodology in describing their contribution to the examination of our objective. RESULT AND CONCLUSION: Three dual action antidepressants are identified: venlafaxine, mirtazapine and milnacipran. These are more effective and better tolerated than the older tricyclic antidepressants in the treatment of an acute episode of depression and in the prevention of relapse. They also offer advantages in that they lack autonomic side-effects of the tricyclics. However, sedation, nausea and sexual side-effects may occur with venlafaxine, and weight gain with mirtazapine.     

Increased adenine nucleotide translocator 1 in reactive astrocytes facilitates glutamate transport

A hallmark of central nervous system (CNS) pathology is reactive astrocyte production of the chronic glial scar that is inhibitory to neuronal regeneration. The reactive astrocyte response is complex; these cells also produce neurotrophic factors and are responsible for removal of extracellular glutamate, the excitatory neurotransmitter that rises to neurotoxic levels in injury and disease. To identify genes expressed by reactive astrocytes, we employed an in vivo model of the glial scar and differential display PCR and found an increase in the level of Ant1, a mitochondrial ATP/ADP exchanger that facilitates the flux of ATP out of the mitochondria. Ant1 expression in reactive astrocytes is regulated by transforming growth factor-beta1, a pluripotent CNS injury-induced cytokine. The significance of increased Ant1 is evident from the observation that glutamate uptake is significantly decreased in astrocytes from Ant1 null mutant mice while a specific Ant inhibitor reduces glutamate uptake in wild-type astrocytes. Thus, the astrocytic response to CNS injury includes an apparent increase in energy mobilization capacity by Ant1 that contributes to neuroprotective, energy-dependent glutamate uptake.     

Endoscopic third ventriculostomy in obstructed hydrocephalus

Forty-three ETV were performed in 46 patients of obstructive hydrocephalus. Study was divided into two groups. Group 1 was with 29 children of less than two years age. Group 2 had seventeen patients of more than 2 years, adolescent and adults. Group 1 had 70% clinical and 63% radiological improvement whereas Group 2 showed 100% clinical and 73% radiological improvement. ETV failed in relieving the symptoms of hydrocephalus in eight patients. They were eventually benefited with VP Shunt. There was one postoperative death, which was not related to the procedure. ETV is an important alternative to VP Shunt in relieving hydrocephalus due to obstruction in CSF pathway.