A role of insular cortex in cardiovascular function

We sought to determine whether the insular cortex contributes to the regulation of arterial blood pressure (AP). Responses to electrical and chemical stimulation of the cortex were studied in the anesthetized, paralyzed, and artificially ventilated Sprague-Dawley rat. The insular cortex was initially defined, anatomically, by the distributions of retrogradely labeled perikarya following injections of wheat germ agglutinin-horseradish peroxidase (WGA-HRP) into the nucleus tractus solitarii (NTS). Injections of WGA-HRP into the insular cortex anterogradely labeled terminals in cardiopulmonary and other divisions of the NTS and confirmed projections revealed by retrograde tracing experiments. Electrical stimulation of the insular cortex elicited elevations of AP (less than or equal to 50 mm Hg) and cardioacceleration (less than or equal to 40 bpm). The locations of the most active pressor sites corresponded closely to the locations of retrogradely labeled cells in layer V of granular and posterior agranular areas of the insular cortex (areas 14 and 13) and the extreme capsule. Maximal pressor responses were obtained at a stimulus intensity of three to five times threshold current of 20-30 microA. Responses elicited mostly with higher-threshold currents were also mapped in areas 2a and 5lb and the claustrum and within the corpus callosum. Unilateral injections into the insular pressor area of the excitatory amino acid monosodium glutamate (L-Glu; 0.05 nmol to 10 nmol) or the rigid structural analogue of L-Glu, kainic acid (KA) (0.4 nmol) (which specifically excite perikarya), caused topographically specific elevations in AP and tachycardia. During the course of the anatomical transport studies, new findings were obtained on the organization and characteristics of the cortical innervation of the NTS and the nucleus reticularis parvocellularis. Topographic relationships between the cortex and the NTS were organized in a more complex manner than previously thought. Cells projecting to caudal cardiopulmonary segments of the NTS were fewer and generally located ventrally and caudally and in a more restricted area than cells projecting rostrally or to the parvicellular reticular formation. Anterograde transport data revealed new presumptive terminal fields in dorsolateral, ventral, periventricular, and commissural regions of the NTS, including an area overlapping the terminal field of the aortic baroreceptor nerve. We conclude that neurons within an area of the insular cortex projecting to multiple brainstem autonomic nuclei, including a region of the NTS innervated by baroreceptor afferents, increase arterial blood pressure and heart rate.(ABSTRACT TRUNCATED AT 400 WORDS)     

The surgical removal of mandibular third molars: a study in decision making.

OBJECTIVE: The aim of this study was to investigate and analyze the angulation of and the various indications for removal of mandibular third molars in Jordanians as a representative Arab sample. METHOD AND MATERIALS: The data included in this retrospective study were obtained from the clinical and radiographic records of 1,282 patients undergoing mandibular third molar surgery during a 5-year period from 1994 to 1999. The indications for removal of the mandibular third molars were classified in accordance with age and gender. The angular position of mandibular third molars was registered. RESULTS: A total of 2,252 mandibular third molars were removed from 740 male patients (57.7%) and 542 female patients (42.3%) aged 14 to 67 years. Pericoronitis was the most common indication for surgery, affecting 1,055 teeth (46.8%). Caries was observed in 519 third molars (23.0%). The vertical angular position was most commonly found (1,383 teeth; 61.4%) followed by the mesioangular position (407 teeth; 18.1%). CONCLUSION: The results obtained in this study are similar to those reported in earlier studies carried out elsewhere, although the incidence of periodontitis among Jordanians was significantly higher and occurred in older patients, and prophylactic removal was performed less frequently than has been reported in other countries.     

Philanthotoxin blocks quisqualate-, AMPA- and kainate-, but not NMDA-, induced excitation of rat brainstem neurones in vivo.

1. The effect of electrophoretic ejection of philanthotoxin (the polyamine toxin, from the Egyptian digger wasp) was tested on responses of brainstem and spinal neurones in the pentobarbitone-anaesthetized rat to excitatory amino acids. 2. Philanthotoxin caused a dose-dependent reduction of responses to quisqualate, alpha-amino-3-hydroxy-5-phenyl-4-isoxazolepropionate (AMPA) and kainate with little effect on those to N-methyl-D-aspartate (NMDA). 3. The time-course of this antagonist action was slow. In particular the rate of recovery was dependent on frequency of ejection of the agonist. This agonist-dependent recovery suggests that philanthotoxin has a channel blocking mode of action on mammalian central neurones.     

Multicentre prospective audit of surgical outcomes and acute complications following short course pre-operative radiotherapy for resectable rectal cancer

BACKGROUND: The addition of short course pre-operative radiotherapy to total mesorectal excision reduces local recurrence in resectable adenocarcinoma of the rectum. In a previous retrospective study potential factors associated with early complications following this combination were identified. The aim of this study was to examine these relationships in a prospective multicentre audit. METHODS: One hundred and seven patients who received short course pre-operative radiotherapy in four cancer centres between 1 October 2001 and 30 September 2002 were included. Data including patient age, radiotherapy field length, overall treatment time, operation type, surgical outcomes and complications occurring within 3 months of the 1st day of radiotherapy were collected. These were compared and combined with the previously studied cohort of 176 patients treated at one centre between 1st January 1998 and 31st December 1999. RESULTS: In the prospective cohort only patient age (P=0.001) was significantly associated with acute complications. However, both the overall treatment time (median 9.0 vs 11.0 days P <0.0001) and field length (median 16.6 vs 17.0 cm P=0.03) were significantly shorter in this cohort when compared to the previous retrospective study. In patients from both studies (n=283), increasing age (P=0.002) and field length (independent of operation type) (P=0.02) were independently associated with an increased risk of acute complications. CONCLUSIONS: This study suggests that meticulous selection of patients for short course pre-operative radiotherapy and smaller planning target volumes may be associated with a lower risk of acute complications. The use of MRI scanning to stage pelvic disease may reduce the number of patients with R1 resections receiving short course pre-operative radiotherapy.     

The species of mallophaga in wild birds in Iran.

Up to date 2 species of Mallophaga have been reported from birds in Iran. Further studies in Tehran area showed that the wild birds harbour more lice. The following species of Mallophage are reported for the first time from birds in Iran. Anaticola crassicornis from Anas clypeata, Laemobothrion maximum from Falco tinnunculus Laemobothrion sp. from Aquila chrysaetos Alcedoecus annulatus from Alcedo athis, Colpocephalum pectinatum and Strigiphilus sp. from Streptopelia turtur, Amrysidea fulvomaculata from Coturnix coturnix, philopterus picae from pica pica, Philopterus ocellatus and Colpocephalum pectinatum from Athene noctua, Philopterus sp. from Turdus ruficollis, Upupicola upupae from Upupa epops, Amyrsidea hexapilosus from Phasianus colchicus, Colpocephalum sp. from Falco cherrug.