Impact of Adaptive Radiotherapy on Locally Advanced Head and Neck Cancer - A Dosimetric and Volumetric Study.

UNLABELLED: Objective of the study is to evaluate volumetric and dosimetric alterations taking place during radiotherapy for locally advanced head and neck cancer (LAHNC) and to assess benefit of replanning in them. MATERIALS AND METHODS: Thirty patients with LAHNC fulfilling the inclusion and exclusion criteria were enrolled in a prospective study. Planning scans were acquired both pre-treatment and after 20 fractions (mid-course) of radiotherapy. Single plan (OPLAN) based on initial CT scan was generated and executed for entire treatment course. Beam configuration of OPLAN was applied to anatomy of interim scan and a hybrid plan (HPLAN30) was generated. Adaptive replanning (RPLAN30) for remaining fractions was done and dose distribution with and without replanning compared for remaining fractions. RESULTS: Substantial shrinkage of target volume (TV) and parotids after 4 weeks of radiotherapy was reported (p<0.05). No significant difference between planned and delivered doses was seen for remaining fractions. Hybrid plans showed increase in delivered dose to spinal cord and parotids for remaining fractions. Interim replanning improved homogeneity of treatment plan and significantly reduced doses to cord (Dmax, D2% and D1%) and ipsilateral parotid (D33%, D50% and D66%) (p<0.05). CONCLUSIONS: Use of one or two mid-treatment CT scans and replanning provides greater normal tissue sparing alongwith improved TV coverage.

Larvicidal activity of few select indigenous plants of North East India against disease vector mosquitoes (Diptera: Culicidae)

Mosquitoes are the vectors of several life threatening diseases like dengue, malaria, Japanese encephalitis and lymphatic filariasis, which are widely present in the north-eastern states of India. Investigations on five local plants of north-east India, selected on the basis of their use by indigenous communities as fish poison, were carried out to study their mosquito larvicidal potential against Anopheles stephensi (malaria vector), Stegomyia aegypti (dengue vector) and Culex quinquefasciatus (lymphatic filariasis vector) mosquitoes. Crude Petroleum ether extracts of the roots of three plants viz. Derris elliptica, Linostoma decandrum and Croton tiglium were found to have remarkable larvicidal activity; D. elliptica extract was the most effective and with LC50 value of 0.307 μg/ml its activity was superior to propoxur, the standard synthetic larvicide. Half-life of larvicidal activity of D. elliptica and L. decandrum extracts ranged from 2-4 days.

Typhoid intestinal perforation: 24 perforations in one patient.

Intestine perforation is one of the most dreaded and common complication of typhoid fever remarkably so in developing world; it usually leads to diffuse peritonitis, requiring early surgical intervention. Despite various measures such as safe drinking water supply and safe disposal of waste, intestinal perforation from salmonellosis remains the most common emergency surgery performed. The incidence continues to rise, so also the mortality, despite new antibiotics and improvement in surgical technique. More disturbing is that we now see increasing number of ileal perforations and colonic involvement. We hereby present a case report of 35-year-old male with multiple (24) intestinal perforation in the Ileum and Cecum.

Prevention of Vascular Apoptosis in Myocardial Infarction by Losartan.

BACKGROUND: Previous studies have demonstrated the occurrence of apoptosis in cardiomyocytes in different types of cardiovascular diseases. This report provides the first evidence for the presence of vascular apoptosis in myocardial infarction induced in rats by occluding the coronary artery for 7 weeks. METHODS AND RESULTS: Apoptosis was characterized by DNA fragmentation, upregulation of caspase-3, downregulation of poly (ADP-ribose) polymerase (PARP), increased c-fos mRNA expression and caspase-3/PARP ratio in aortic vascular smooth muscle cells. The results show apoptotic changes in 10-25% of the aortic vascular cells after myocardial infarction; these alterations were prevented after treating the 3-week operated animals with an angiotensin II receptor antagonist, losartan (25 mg/kg/day; intraperitoneal) for 4 weeks. Cultured rat aortic smooth muscle cells exposed to 10 nmol/L angiotensin II for 48 hours also exhibited apoptotic changes, which were inhibited by 10 nmol/L losartan. CONCLUSIONS: These results suggest that vascular apoptosis occurs in myocardial infarction, and this may be due to an increase in the circulating levels of angiotensin II.

Early Changes in Minimal Luminal Diameter After Balloon Angioplasty and Directional Coronary Atherectomy.

Early elastic recoil has been implicated in the pathophysiology of restenosis after balloon coronary angioplasty (PTCA). Directional atherectomy (DCA) may significantly attenuate this vessel wall reaction by altering the vessel wall architecture, specifically by removing or injuring the medial smooth muscle cells. We compared the magnitude of early changes in minimal lumen diameter (MLD) after DCA followed by adjunctive PTCA (group I) in comparison to PTCA alone (group II). In two groups of 30 lesions, matched for vessel size and location, group I cases showed significantly less recoil than group II cases, as assessed by routinely performed 15 minute post-procedure angiograms: mean changes in post-procedure MLD +0.06mm (increase) vs. -0.31mm (decrease) respectively, p = 0.02. In a histopathologic substudy of the DCA treated patients, those without early recoil had significantly higher incidence of media removal compared to patients with recoil (50% vs. 7%, p = 0.03). Therefore, early changes in MLD, presumably related to elastic recoil, are less with DCA and adjunct PTCA in comparison to PTCA alone. Attenuation of early recoil may be an additional mechanism accounting for the acute lumen gain achieved with this technique.

Thrombin Generation and Activity During Coronary Angioplasty: Influence of Angiographic Lesion Morphology.

OBJECTIVE: To investigate the relationships between coronary atherosclerotic plaque injury, lesion morphology, and activation of the coagulation cascade. BACKGROUND: Balloon angioplasty of coronary lesions may result in intracoronary thrombin generation and activity. It is unknown whether the angiographic morphology of the lesion prior to intervention, an indicator of the presence of thrombus in the lesion, is a determinant of the degree of coagulation cascade activation. METHODS AND RESULTS: Biochemical markers of thrombin generation (prothrombin fragment F1+2) and thrombin activity (fibrinopeptide A; FPA) were measured in coronary blood before, 1 and 10 minutes after percutaneous transluminal coronary angioplasty (PTCA) in 24 patients with an angiographically complex lesion morphology and 24 patients with an angiographically simple lesion morphology. Using previously defined criteria, 18 of the 48 patients (38%) demonstrated a significant rise in coronary plasma F1+2; 8 of these 18 (44%) had simple and 10 of 18 (55%) had complex angiographic lesion morphologies (p=NS). With respect to thrombin activity, 15 of the 48 patients (31%) demonstrated a significant rise in coronary plasma FPA; 7 of these 15 patients (47%) had a simple lesion morphology and 8 (53%) had a complex morphology (p=NS). When analyzed as a group, patients with complex lesion morphologies demonstrated a small elevation in coronary plasma levels of FPA 10 minutes post-PTCA (median 3.2 ng/ml, 95% CI 2.4Ð5.8 ng/ml) in comparison to the levels measured proximal to the lesion pre-PTCA (median 2.1 ng/ml, 95% CI 1.6Ð3.5 ng/ml; p=0.05). In contrast, in the group of patients with simple lesion morphologies, the plasma FPA levels proximal to the lesion pre-PTCA (median 2.1 ng/ml, 95% CI 1.5 to 3.9 ng/ml) were similar to those measured 10 minutes after the procedure (median 2.0 ng/ml, 95% CI 1.5 to 6.3 ng/ml; p=NS). CONCLUSIONS: In comparison to patients with angiographically complex lesions, patients with angiographically simple lesions demonstrate a similar incidence (~33%) of elevated coronary plasma thrombin generation (F1+2) and activity (FPA) after PTCA. As a group, patients with angiographically complex lesions (irregular borders, overhanging edges, filling defects) demonstrate a slightly greater increase in thrombin activity in comparison to patients with simple lesion morphologies. Percutaneous coronary interventions of lesions with a wide variety of angiographic morphologies are prone to result in activation of the coagulation cascade.