An induced blood pressure rise does not alter upper airway resistance in sleeping humans

Wilson, Christine R., Shalini Manchanda, David Crabtree,James B. Skatrud, and Jerome A. Dempsey. An induced blood pressurerise does not alter upper airway resistance in sleeping humans.J. Appl. Physiol. 84(1): 269-276, 1998.Sleep apnea is associated with episodic increases in systemicblood pressure. We investigated whether transient increases in arterialpressure altered upper airway resistance and/or breathingpattern in nine sleeping humans (snorers and nonsnorers). Apressure-tipped catheter was placed below the base of the tongue, andflow was measured from a nose or face mask. Duringnon-rapid-eye-movement sleep, we injected 40- to 200-µg iv boluses ofphenylephrine. Parasympathetic blockade was used if bradycardia wasexcessive. Mean arterial pressure (MAP) rose by 20 ± 5 (mean ± SD) mmHg (range 12-37 mmHg) within 12 s and remained elevated for105 s. There were no significant changes in inspiratory or expiratorypharyngeal resistance (measured at peak flow, peak pressure, 0.2 l/s orby evaluating the dynamic pressure-flow relationship). Atpeak MAP, end-tidal CO₂ pressure fell by 1.5 Torr and remained low for 20-25 s. At 26 s after peak MAP, tidal volume fell by 19%, consistent with hypocapnic ventilatory inhibition. We conclude that transient increases in MAP of a magnitude commonly observed during non-rapid-eye-movement sleep-disordered breathing do not increase upper airway resistance and, therefore, willnot perpetuate subsequent obstructive events.

     

Family Physicians' Barriers to Cancer Screening in Extremely Obese Patients

Extremely obese women are less likely than nonobese women to receive breast and cervical cancer screening examinations. Reasons for this disparity are unclear and may stem from patient and/or physician barriers. This sequential mixed‐methods study used individual in‐depth interviews of 15 family physicians followed by a mail survey of 255 family physicians (53% response rate) to understand the barriers they faced in performing cancer screening examinations in extremely obese women. Barriers fell into three main areas: (i) difficulty doing pelvic and breast exams; (ii) inadequate equipment; and (iii) challenges overcoming patient barriers and refusal. This led some physicians to avoid performing breast and pelvic examinations on extremely obese women. Having more knowledge about specific examination techniques was associated with less difficulty in palpating lumps on breast and pelvic examinations (P < 0.005). Physicians perceived that embarrassment, aversion to undressing, and avoidance of discussions related to their weight were the most frequent barriers extremely obese women had with getting physical examinations. Educating and/or motivating patients and addressing fears were strategies used most frequently when patients refused mammograms or Pap smears. Interventions focusing on physician barriers, such as educating them on specific examination techniques, obtaining adequate equipment and supplies, and providing resources to assist physicians in dealing with patient barriers and refusal, may be fruitful in increasing cancer screening rates in extremely obese patients. Future research studies testing the effectiveness of these strategies are needed to improve cancer outcomes in this high‐risk population.     

The production of neuraminidase and fucosidase by Helicobacter pylori: Their possible relationship to pathogenicity

Abstract The pathogenicity of enterobacteria often correlates with their production of neuraminidase (sialidase). Forty-nine Helicobacter pylori isolates have therefore been examined for their production of neuraminidase and other glycosidases. All 49 isolates produced considerable neuraminidase (median 228 IU/μgmg protein, interquartile range 121–370), pH optimum 7.5. Nine of the 49 also produced fucosidase (median 23 IU/μgmg protein, interquartile range 12–39), pH optimum 7.0. Production of these enzymes did not correlate with bacterial Cag A expression or duodenal ulceration. Neutrophils exposed to neuraminidase show increased adherence to endothelium so the neuraminidase production by H. pylori could partly explain the predominant neutrophil inflammatory infiltrate seen in H. pylori -associated gastritis. Inhibition of this enzyme by use of neuraminidase-inhibitors could be a useful therapeutic approach.     

Family Physicians' Practices and Attitudes Regarding Care of Extremely Obese Patients

Despite the growing epidemic of extreme obesity in the United States, weight management is not adequately addressed in primary care. This study assessed family physicians' practices and attitudes regarding care of extremely obese patients and factors associated with them. A cross‐sectional, self‐administered survey was mailed to 500 family physicians in New Jersey (NJ) during March–May 2008. Measures included knowledge, weight management approaches, attitudes toward managing obesity, challenges with examinations, availability of supplies, and strategies to improve care. Response rate was 53% (N = 255). Bariatric surgery and weight loss medications were infrequently recommended, particularly in physicians with higher volume of extremely obese patients (odds ratio (OR) 0.38; 95% confidence interval (CI) 0.23, 0.62 and OR 0.51; 95% CI 0.31, 0.85 for surgery and medications, respectively). Higher knowledge was associated with increased frequency of recommendations of weight loss medications (P < 0.0001) and bariatric surgery (P < 0.0001). There was a high prevalence of negative attitudes, particularly in younger physicians and those with lower patient volume. Increased knowledge of weight‐loss diets was associated with less dislike in discussing weight loss (P < 0.0001), less frustration (P = 0.0001), less belief that treatment is often ineffective (P < 0.0001), and less pessimism about patient success (P = 0.0002). Many providers encountered challenges performing examinations on extremely obese patients. More education of primary care physicians, particularly on bariatric surgery, specific examination techniques, and availability of community resources for obese persons is needed. Further research is needed to determine if interventions to increase knowledge of physicians will lead to less negative attitudes toward weight loss and extremely obese patients.     

Whole-genome sequence analysis of Pseudomonas syringae pv. phaseolicola 1448A reveals divergence among pathovars in genes involved in virulence and transposition

Pseudomonas syringae pv. phaseolicola, a gram-negative bacterial plant pathogen, is the causal agent of halo blight of bean. In this study, we report on the genome sequence of P. syringae pv. phaseolicola isolate 1448A, which encodes 5,353 open reading frames (ORFs) on one circular chromosome (5,928,787 bp) and two plasmids (131,950 bp and 51,711 bp). Comparative analyses with a phylogenetically divergent pathovar, P. syringae pv. tomato DC3000, revealed a strong degree of conservation at the gene and genome levels. In total, 4,133 ORFs were identified as putative orthologs in these two pathovars using a reciprocal best-hit method, with 3,941 ORFs present in conserved, syntenic blocks. Although these two pathovars are highly similar at the physiological level, they have distinct host ranges; 1448A causes disease in beans, and DC3000 is pathogenic on tomato and Arabidopsis. Examination of the complement of ORFs encoding virulence, fitness, and survival factors revealed a substantial, but not complete, overlap between these two pathovars. Another distinguishing feature between the two pathovars is their distinctive sets of transposable elements. With access to a fifth complete pseudomonad genome sequence, we were able to identify 3,567 ORFs that likely comprise the core Pseudomonas genome and 365 ORFs that are P. syringae specific.     

Sonographic staging of the developmental status of mouse embryos in utero

In mouse developmental studies it is frequently desirable to isolate embryos of a specific age. However, the traditional staging of embryonic development based on postcoital dates often erroneously predicts the embryonic age, resulting in unwarranted sacrifice of the pregnant mother. Here we report a noninvasive way of staging embryonic development in utero. A clinical 14 MHz ultrasound system was employed to assess the morphology and size of developing embryos from embryonic day 7.5 to 18.5. We demonstrate that the developmental age of the mouse embryos can be accurately determined based on the sonographic morphology and size of the embryos. This noninvasive ultrasound application requires no anesthesia of the mice and the entire process of staging can be completed within 5-10 min. Empirically, this approach is applicable to mice of various genetic backgrounds and significantly enhances the efficiency of studying murine embryogenesis.