Fulminant radiation-induced necrosis after stereotactic radiation therapy to the posterior fossa. Case report and review of the literature

The problem of radiation-induced necrosis of normal brain surrounding the target area has been a major catalyst for the development of stereotactically focused radiation therapy. According to current opinion, the effects of stereotactic irradiation are confined to the region targeted. The authors present a case in which the administration of a conventional dose of stereotactically focused irradiation for treatment of a pilocytic astrocytoma produced fulminant necrosis that necessitated a combination of intensive surgical and medical management, after which the patient improved over the course of 1 year. Concomitant with his improvement, the initially remarkable findings on magnetic resonance imaging gradually resolved. In this presentation the authors emphasize the need to evaluate alternatives carefully before a decision is made to administer therapeutic irradiation. Furthermore, they explore the roles that target, host, and dosage factors play in hypersensitivity to radiation injury, the detection of these factors before treatment, and the administration of radioprotective agents. With the growing use of stereotactically focused irradiation as a primary treatment modality for a variety of neurosurgical conditions, it is important to be cognizant of its uncommon but potentially lethal side effects. A cooperative multicenter database in which the outcomes and morbidity following stereotactic irradiation are recorded is essential to the detection of relatively uncommon but severe complications such as those observed in this case.     

Comparative evaluation of marginal integrity of two new fissure sealants using invasive and non-invasive techniques: a SEM study

In this era of preventive dentistry, many dental materials used for prevention of dental diseases are available. Since last few decades efforts are being directed towards prevention of dental caries which is one of the major dental diseases tormenting mankind. The main avenues available are plaque control, use of systemic and local fluorides and use of fissure sealants. There are many factors that contribute towards a successful sealant restoration such as properties of enamel, duration of etching, acid used for etching, manipulative variables. However, one of the prime factors governing the efficacy and life expectancy of a sealant is the marginal adaptability. This study was carried out on a total of 40 intact premolar teeth, which were divided in four main groups and subjected to evaluation under Scanning Electron Microscope. The parameters checked were the width and the number of marginal gaps. The results obtained showed that Teethmate had better marginal integrity and favored the use of invasive technique over non-invasive technique.     

Surgical considerations in malignant neoplasia of nose and paranasal sinuses

Most recurrences of cancers of the nose and paranasal sinuses are attributed to inadequate local control of disease. Since such tumours are usually advanced a standard maxillectomy procedure is inadequate Nevertheless batter local control is obtainable by modifying palatal zygomatic or superior bone cuts (cranifacial resection) or including an appropriate part of the septum in the specimen. This paper describes 78 such cases undergoing surgicad ablation. Uses of CT and modifications of standard surgical techniques adapted for various tumour extensions are described.     

Clinical course of isolated ventricular septal defect: An Indian experience

To define the clinical course of ventricular septal defect, 410 consecutive patients with isolated ventricular septal defect were evaluated over a period of 13 years. Their age ranged from 12 days to 24 years at the time of first visit to the hospital. Patients with less than 2 years follow-up period were excluded. One hundred and fifty seven patients were one year of age or less. The left to right shunt size remained the same in 52.4% of cases. In 34.4% the shunt size decreased, with complete closure of ventricular septal defect in 8.8%. Closure of ventricular septal defect was observed even in patients who had initially presented with large left to right flow, and congestive heart failure in infancy. Right ventricular outflow tract obstruction developed in 8.5% of patients usually between 2 and 10 years of age. Murmur of aortic regurgitation appeared in 8.9% on follow-up. Infective endocarditis developed in 6 cases. The unfortunate complication of Eisemenger's complex was seen in 3 patients; they had not returned for follow up for a long period of time. Hence, our data show that the left to right shunt across the ventricular septal defect decreases in about one-third of patients. However, a regular follow up is essential to prevent development of Eisenmenger's complex and for early detection of other complications like aortic regurgitation and right ventricular outflow tract obstruction.     

Hypophosphatemic rickets : Easy to diagnose, difficult to treat

Hypophosphatemic rickets (HR) has generated a lot of interest in recent times. There is need to recognize this disorder and differentiate it from the more common nutritional rickets because the therapy is different. It is also important to emphasize that a detailed clinical examination with pedigree analysis and easily available biochemical tests are adequate to establish the diagnosis in most cases. This report presents three families with hypophosphatemic rickets. Interestingly, many of these patients had a mixed picture of HR and nutritional rickets. Their important features are described with special emphasis on early initiation of treatment with oral phosphate and stringent monitoring of renal functions to prevent development of irreversible renal insufficiency.     

P3 event-related evoked potential in young adults

P3 component of event related potential reflects memory and decision making processes. It has been applied as an index of information processing in a wide variety of normal and cognitive impaired subjects. Scalp P3 was elicited in 24 male neurologically and audiologically normal young subjects of 17-20 years (Av. 17.7) of age. Standard auditory 'Oddball' paradigm involving simple discrimination task of concentrating on infrequent (target) stimulus and ignoring frequent (non target) stimulus was employed. Evoked response trials of discriminating 32 target stimuli out of 160 total presented (20% target and 80% non target randomly) were replicated and analysed by computer. Latency of P3 as 305 +/- 18.4 msec and amplitude 6.5 +/- 2.1 uv are being reported which are comparable with age and sex matched subjects of western world.     

Chelation in metal intoxication. XIV. Comparative effect of thiol and amino chelators on lead-poisoned rats with normal or damaged kidneys

D-Penicillamine (DPA), diethyldithiocarbamate (DDC), L-cysteine, ethylenediaminetetraacetic acid (EDTA), cyclohexylenediaminetetraacetic acid (CDTA), and diethylene triamine pentaacetic acid (DTPA) were compared for their efficacy to enhance urinary excretion of Pb, to reduce Pb concentration of body organs, and to restore the enhanced urinary excretion of delta-aminolevulinic acid (delta-ALA), the inhibited activities of blood delta-ALA dehydratase, and renal enzymes in Pb-administered rats (10 mg/kg, po, 4 weeks) with normal or experimentally damaged kidneys. The acute renal damage was induced by uranyl acetate (3 mg/kg, sc, once) prior to treatment with the chelators (0.3 mmol/kg, ip, twice) and evaluated by enhanced urinary excretion of diagnostic enzymes and inhibition in their renal activities. Among thiol chelators, DPA was the most effective followed by DDC in enhancing the urinary excretion of Pb, reducing the concentration of Pb in blood, kidneys and liver, and in restoring Pb-induced biological alterations in urine, blood, and kidneys. Among amino carboxylic acids, DTPA was the most effective and EDTA and CDTA were about equally potent in countering Pb toxicity. Protection was more marked in animals with normal kidneys than in those with acutely damaged kidneys.