Reproductive competition between polygynous parasite queens in ant colonies

BACKGROUND: Evaluation of percutaneous tracheostomy (PT) with the guide wire dilating forceps (GWDF) technique. METHODS: Prospective study of perioperative complications, retrospective analysis of early and late complications in an ICU in a teaching university hospital. RESULTS: The success rate of the procedure was 96.5%. The average procedure time in 171 consecutive patients was 5.0 min. Perioperative complications requiring surgical or medical intervention occurred in 6.4% of 171 patients. This included conversion to surgical tracheostomy, which was necessary in six patients (3.5%). Major complications while being cannulated occurred in 2.4% of 164 patients but seemed mostly unrelated with the GWDF technique itself. Late complications (after decannulation) were mostly minor and occurred in 22.6% of 106 patients. Only one patient (0.9%) had a symptomatic tracheal stenosis developed. CONCLUSION: Percutaneous tracheostomy with the guide wire dilating forceps technique is easy to perform at the bedside with few late complications. However, in our study, perioperative and immediate postoperative bleeding complications (minor and major) occur quite often

Baroreflex control of muscle sympathetic nerve activity after carotid body tumor resection

Bilateral carotid body tumor resection causes a permanent attenuation of vagal baroreflex sensitivity. We retrospectively examined the effects of bilateral carotid body tumor resection on the baroreflex control of sympathetic nerve traffic. Muscle sympathetic nerve activity was recorded in 5 patients after bilateral carotid body tumor resection ( 1 man and 4 women, 51 +/- 11 years) and 6 healthy control subjects ( 2 men and 4 women, 50 +/- 7 years). Baroreflex sensitivity was calculated from changes in R-R interval and muscle sympathetic nerve activity in response to bolus injections of phenylephrine and nitroprusside. In addition, sympathetic responses to the Valsalva maneuver and cold pressor test were measured. The integrated neurogram of patients and control subjects contained a similar pattern of pulse synchronous burst of nerve activity. Baroreflex control of both heart rate and sympathetic nerve activity were attenuated in patients as compared with control subjects [ heart rate baroreflex sensitivity: 3.68 +/- 0.93 versus 11.61 +/- 4.72 ms/mm Hg ( phenylephrine, P = 0.011) and 2.53 +/- 1.36 versus 5.82 +/- 1.94 ms/mm Hg ( nitroprusside, P = 0.05); sympathetic baroreflex sensitivity: 3.70 +/- 2.90 versus 7.53 +/- 4.12 activity/100 beats/mm Hg ( phenylephrine, P = 0.10) and 3.93 +/- 4.43 versus 15.27 +/- 10.03 activity/100 beats/mm Hg ( nitroprusside, P = 0.028)]. The Valsalva maneuver elicited normal reflex changes in muscle sympathetic nerve activity, whereas heart rate responses were blunted in the patients with bilateral carotid body tumor resection. Maximal sympathetic responses to the cold pressor test did not differ between the two groups. Denervation of carotid sinus baroreceptors as the result of bilateral carotid body tumor resection produces chronic impairment of baroreflex control of both heart rate and sympathetic nerve activity. During the Valsalva maneuver, loss of carotid baroreflex control of heart rate is less well compensated for by the extra carotid baroreceptors than the control of muscle sympathetic nerve activit

Baroreflex and chemoreflex function after bilateral carotid body tumor resection

Objective To investigate whether bilateral carotid body tumor resection invariably and chronically affects arterial baroreflex or peripheral chemoreflex function. Methods We studied eight consecutive patients (two men and six women; ages 48.1 +/- 11.8 years), a median time of 3.4 years (range 1.3-20.6 years) after bilateral carotid body tumor resection, and 12 healthy control individuals (eight men and four women; ages 53.7 +/- 10.1 years). Baroreflex sensitivity (phenylephrine), blood pressure and its variability (24 h Spacelabs and 5 h Portapres recordings), responses to standard cardiovascular reflex tests and the ventilatory responses to normocapnic and hypercapnic hypoxia were assessed. Results Baroreflex sensitivity was lower in patients (6.4 +/- 7.2 ms/mmHg) than in controls (14.7 +/- 6.6 ms/mmHg; P +/- 0.011). Mean office blood pressure and heart rate were normal in patients (1123.3 +/- 11.9/79.0 +/- 7.3 mmHg and 67.5 +/- 9.4 beats/min, respectively) and controls (117.8 +/- 10.6/74.0 +/- 6.8 mmHg and 61.1 +/- 9.2 beats/min, respectively). Blood pressure variability was increased during ambulatory measurements. Three patients exhibited orthostatic hypotension. The Valsalva ratio, an index of baroreflex-mediated cardiovagal innervation, was lower in patients (1.4 +/- 0.2) than in controls (1.8 +/- 0.5; P +/- 0.008). The normocapnic ventilatory response to hypoxia was absent in all patients, whereas a small residual response to hypoxia was observed under hypercapnic conditions in two patients. Conclusions Bilateral carotid body tumor resection results in heterogeneous expression of arterial baroreflex dysfunction, whereas the normocapnic hypoxic drive is invariably abolished as a result of peripheral chemoreflex failure. (C) 2003 Lippincott Williams Wilkin

Arterial baroreflex and peripheral chemoreflex function after radiotherapy for laryngeal or pharyngeal cancer

Purpose: Denervation of the carotid sinus causes baroreflex and chemoreflex failure, resulting in labile hypertension and loss of hypoxic responsiveness. We investigated whether radiation therapy for laryngeal or pharyngeal cancer affects baroreflex and chemoreflex function. Methods and Materials: Twelve patients were studied after radiation therapy for locally advanced laryngeal or pharyngeal cancer (11 male, 1 female, age: 56.0 +/- 7.9 years), 3.3 years (median; range 1.0-4.7) after radiotherapy and 15 healthy controls (11 male, 4 female, 53.4 +/- 9.2 years). We measured baroreflex sensitivity (phenylephrine), blood pressure level and variability (24-h Spacelabs and 5-h Portapres recordings), responses to cardiovascular reflex tests, and the ventilatory responses to normocapnic and hypercapnic hypoxia. Results: Baroreflex sensitivity was lower in patients (9.7 +/- 7.8 ms/mm Hg) than in controls (17.5 +/- 10.3 ms/nun Hg, p = 0.011). Mean office blood pressure was significantly higher in patients (141.5 +/- 27.8/89.2 +/- 10.6 mm Hg, 63.3 +/- 12.3 bpm) than in controls (117.3 +/- 10.1/75.1 +/- 6.8 mm Hg, 61.8 +/- 10.8 bpm). Blood pressure variability was not different between groups, nor were the responses to reflex tests. The normo/hypercapnic ventilatory response to hypoxia was similar in patients (0.21 +/- 0.10/1.37 +/- 0.60 L/min/%) and controls (0.22 +/- 0.16/1.19 +/- 0.78 L/min/%). Conclusions: Radiation therapy for laryngeal or pharyngeal carcinoma does not affect chemoreflex function, but results in an attenuated baroreflex sensitivity. Clinically relevant blood pressure lability is absent however. (C) 2002 Elsevier Science In

Long-term effects of carotid sinus Denervation on arterial blood pressure in humans

Background-After experimental carotid sinus denervation in animals, blood pressure (BP) level and variability increase markedly but normalize to preoperative levels within 10 to 14 days. We investigated the course of arterial BP level and variability after bilateral denervation of the carotid sinus baroreceptors in humans. Methods and Results-We studied 4 women (age 41 to 63 years) who were referred for evaluation of arterial baroreflex function because of clinical suspicion of carotid sinus denervation attributable to bilateral carotid body tumor resection. The course of BP level and variability was assessed from repeated office and 24-hour ambulatory measurements (Spacelabs/Portapres) during I to 10 years of (retrospective) follow-up. Rapid cardiovascular reflex adjustments to active standing and Valsalva's maneuver were assessed. Office BP level increased from 132/86 mm Hg (range, 118 to 148/80 to 92 mm Hg) before bilateral surgery to 160/105 mm Hg (range, 143 to 194/90 to 116 mm Hg) 1 to 10 years after surgery. During continuous 24-hour noninvasive BP recording (Portapres), a marked BP variability was apparent in all 4 patients. Initial symptomatic hypotension on change to the upright posture and abnormal responses to Valsalva's maneuver were observed. Conclusions-Acute carotid sinus denervation, as a result of bilateral carotid body tumor resection, has a long-term effect on the level. variability, and rapid reflex control of arterial BP. Therefore, in contrast to earlier experimental observations, the compensatory ability of the baroreceptor areas outside the carotid sinus seems to be of limited importance in the regulation of BP in human

Progress against laryngeal cancer in The Netherlands between 1989 and 2010

Cancer of the larynx is a frequently occurring head and neck cancer in The Netherlands. The main risk factors are smoking and excessive alcohol consumption. The aim of our study was to evaluate the progress against laryngeal cancer by studying trends in incidence, mortality and survival in The Netherlands. All patients in The Netherlands Cancer Registry diagnosed with invasive primary squamous cell carcinoma of the larynx during the period 1989-2010 were included for analysis. Time trends in incidence, mortality, treatment and survival were described for the total group and stratified by sex and subsite: glottis, supraglottis and subglottis. The most frequently affected subsite for men was the glottis (69%) and for women the supraglottis (55%). Glottic cancer was diagnosed at lower stages than supraglottic cancer. Incidence and mortality rates decreased for males with -2.5 and -2.8% per year, respectively, but remained stable for women, except for an increasing mortality rate in older women (EAPC: +2.5%). Five-year relative survival rates were stable for glottic (85%) and supraglottic (50%) cancer, whereas patients with high-staged cancers more often received radiotherapy. Multivariable analysis showed lower relative excess risks of dying for women, younger patients ( What's new? Cancer of the larynx is a common malignancy in The Netherlands and is linked to smoking and abundant alcohol consumption. As this study shows, however, while incidence and mortality rates for laryngeal cancer decreased for Dutch males over the period 1989-2010, in line with changes in smoking habits, rates remained stable or increased for women. Furthermore, the application of radiotherapy increased in patients with high-staged cancer, but five-year relative survival rates remained stable for glottic and supraglottic cancer. So, while progress has been made in some respects, The Netherlands has seen little improvement in laryngeal cancer survival