Mucociliary clearance,airway inflammation and nasal symptoms in urban motorcyclists

OBJECTIVES:There is evidence that outdoor workers exposed to high levels of air pollution exhibit airway inflammation and increased airway symptoms. We hypothesized that these workers would experience increased airway symptoms and decreased nasal mucociliary clearance associated with their exposure to air pollution.METHODS:In total, 25 non-smoking commercial motorcyclists, aged 18-44 years, were included in this study. These drivers work 8-12 hours per day, 5 days per week, driving on urban streets. Nasal mucociliary clearance was measured by the saccharine transit test; airway acidification was measured by assessing the pH of exhaled breath condensate; and airway symptoms were measured by the Sino-nasal Outcome Test-20 questionnaire. To assess personal air pollution exposure, the subjects used a passive-diffusion nitrogen dioxide (NO₂) concentration-monitoring system during the 14 days before each assessment. The associations between NO₂ and the airway outcomes were analyzed using the Mann-Whitney test and the Chi-Square test. Clinicaltrials.gov: {"type":"clinical-trial","attrs":{"text":"NCT01976039","term_id":"NCT01976039"}}NCT01976039.RESULTS:Compared with clearance in healthy adult males, mucociliary clearance was decreased in 32% of the motorcyclists. Additionally, 64% of the motorcyclists had airway acidification and 92% experienced airway symptoms. The median personal NO₂ exposure level was 75 mg/m³ for these subjects and a significant association was observed between NO₂ and impaired mucociliary clearance (p = 0.036).CONCLUSION:Non-smoking commercial motorcyclists exhibit increased airway symptoms and airway acidification as well as decreased nasal mucociliary clearance, all of which are significantly associated with the amount of exposure to air pollution.     

Contrasting effects of recombinant human granulocyte-macrophage colony- stimulating factor (CSF) and granulocyte CSF treatment on the cycling of blood elements in childhood-onset cyclic neutropenia

Recombinant human granulocyte colony-stimulating factor (G-CSF) treatment has been shown to increase average neutrophil counts substantially in patients with childhood-onset cyclic neutropenia (or "cyclic hematopoiesis"), but not to eliminate the cyclic oscillations of neutrophil counts or those of other blood elements (monocytes, platelets, eosinophils, and reticulocytes) that are characteristic of this hematopoietic disorder. Indeed, oscillations of neutrophil counts are amplified during G-CSF treatment. We have compared the effects of recombinant granulocyte-macrophage-CSF (GM-CSF) with those of G-CSF in three patients with this disease (2 men and 1 woman, 17, 30, and 32 years of age). These patients were treated with GM-CSF (2.1 micrograms/kg/day, subcutaneously) for 6 weeks, preceded and followed by 6 to 13 weeks of detailed observation to document changes in the cyclic oscillations of blood neutrophils and other blood elements; two of the patients were subsequently treated with G-CSF (5.0 micrograms/kg/d, subcutaneously) and observed for comparable periods of time. Unlike G-CSF treatment, which increased average neutrophil counts more than 20-fold, GM-CSF increased neutrophil counts only modestly, from 1.6- to 3.9-fold, although eosinophilia of varying prominence was induced in each patient. However, at the same time, GM-CSF treatment dampened or eliminated the multilineage oscillations of circulating blood elements (neutrophils, monocytes, platelets, and/or reticulocytes) in each of the patients. In contrast, G-CSF treatment of the same patients markedly amplified the oscillations of neutrophil counts and caused the cycling of other blood elements (monocytes in particular) to become more distinct. These findings support the conclusion that the distinctive cycling of blood cell production in childhood-onset cyclic neutropenia results from abnormalities in the coordinate regulation of both GM-CSF-responsive, multipotential progenitor cells and G-CSF-responsive, lineage-restricted, neutrophil progenitors.     

运动性心律失常

运动性心律失常是指发生于机体剧烈运动期间或之后的心律失常。临床表现不一,从心悸、头晕、晕厥、心绞痛、急性心肌梗死和充血性心力衰竭,甚至到心脏性猝死。运动性心律失常可见于心肌缺血,如患有动脉粥样硬化性心脏病以及患有原发性或继发性心肌病的患者。然而,也可能发生在似乎健康的个体。在后一组人群中,运动性心律失常可以是良性的,但也可以是获得性(如药物诱发)或先天性(如先天性长QT综合征或致心律失常性右室发育不良)心电活动或结构的异常而呈恶性。这种潜在病理生理学机制的复杂性,使运动性心律失常的诊断和治疗成为临床医学上的…     

Evaluation of normal-sized ovaries associated with primary peritoneal serous carcinoma for possible precursors of ovarian serous carcinoma

OBJECTIVE: Three groups of "high-risk" ovaries have previously been studied for possible precursors of ovarian carcinoma: ovaries removed prophylactically from women at high risk, normal ovaries contralateral to a unilateral ovarian carcinoma, and normal ovarian tissue found adjacent to primary ovarian carcinomas. No data are available for a fourth high-risk group: normal-sized ovaries from women with primary peritoneal serous carcinoma. METHODS: Grossly normal-sized ovaries from 26 patients with primary peritoneal serous carcinoma were compared to normal-sized ovaries from 75 controls. Controls were divided at the median age for age matching. Cortical inclusions, surface epithelial invaginations (clefts), surface papillary proliferation, and calcifications were examined. RESULTS: Case versus control comparisons showed, respectively, inclusions in 92% and 68% of patients, clefts in 54% and 59%, and papillomatosis in 35% and 16%. For each profile of ovary on one section, cases versus controls, respectively, had a mean number of inclusions of 5.55 and 3.97, size of the largest inclusion of 1.28 and 1.27 mm, and depth of the deepest cleft of 1.04 and 0.9 mm. After controlling for age, correcting for multiple comparisons and using two-sided chi square, there were no significant differences between cases and controls in all the parameters measured. In comparing the two control groups, the only significant finding was that the young group displayed deeper clefts than the older group (2.06 versus 0.9 mm, respectively). CONCLUSION: Grossly normal-sized ovaries from women with primary peritoneal serous carcinoma display no significant differences in inclusions, clefts, papillomatosis, and calcifications in comparison to age-matched controls.     

Structural investigation of three distinct amorphous forms of Ar hydrate

Three amorphous forms of Ar hydrate were produced using the crystalline clathrate hydrate Ar·6.5H₂O (structure II, Fd$\bar{3}$m, a ≈ 17.1 Å) as a precursor and structurally characterized by a combination of isotope substitution (³⁶Ar) neutron diffraction and molecular dynamics (MD) simulations. The first form followed from the pressure-induced amorphization of the precursor at 1.5 GPa at 95 K and the second from isobaric annealing at 2 GPa and subsequent cooling back to 95 K. In analogy to amorphous ice, these amorphs are termed high-density amorphous (HDA) and very-high-density amorphous (VHDA), respectively. The third amorph (recovered amorphous, RA) was obtained when recovering VHDA to ambient pressure (at 95 K). The three amorphs have distinctly different structures. In HDA the distinction of the original two crystallographically different Ar guests is maintained as differently dense Ar–water hydration structures, which expresses itself in a split first diffraction peak in the neutron structure factor function. Relaxation of the local water structure during annealing produces a homogeneous hydration environment around Ar, which is accompanied with a densification by about 3%. Upon pressure release the homogeneous amorphous structure undergoes expansion by about 21%. Both VHDA and RA can be considered frozen solutions of immiscible Ar and water in which in average 15 and 11 water molecules, respectively, coordinate Ar out to 4 Å. The local water structures of HDA and VHDA Ar hydrates show some analogy to those of the corresponding amorphous ices, featuring H₂O molecules in 5- and 6-fold coordination with neighboring molecules. However, they are considerably less dense. Most similarity is seen between RA and low density amorphous ice (LDA), which both feature strictly 4-coordinated H₂O networks. It is inferred that, depending on the kind of clathrate structure and occupancy of cages, amorphous states produced from clathrate hydrates display variable local water structures.

Three amorphous forms of Ar clathrate hydrate (pressure-amorphized, annealed and recovered) were characterized by isotope substitution (³⁶Ar) neutron diffraction and molecular dynamics and their local coordinations analyzed and compared to pure ice.     

Neurological complications of thoracic endovascular aortic repair

Thoracic endovascular aortic repair (TEVAR) has decreased the morbidity and mortality associated with open surgical repair of descending thoracic aortic diseases, but important complications unique to the procedure remain. Spinal cord ischemia and infarction is a recognized complication caused by endovascular coverage or injury to spinal cord collateral vessels. Stroke is a consequence of thromboembolism or coverage of aortic arch branch vessels with insufficient collateral circulation. Understanding the risk factors and the pathophysiology of neurological complications of TEVAR are important for the successful anesthetic and surgical management and treatment of patients undergoing endovascular procedures involving the thoracic aorta.     

Natural history of gutter-related type Ia endoleaks after snorkel/chimney endovascular aneurysm repair

Objective

Alternative endovascular strategies using parallel or snorkel/chimney (chimney endovascular aneurysm repair [ch-EVAR]) techniques have been developed to address the lack of widespread availability and manufacturing limitations with branched/fenestrated aortic devices for the treatment of complex abdominal aortic aneurysms. Despite high technical success and midterm patency of snorkel stent configurations, concerns remain regarding the perceived increased incidence of early gutter-related type Ia endoleaks. We aimed to evaluate the incidence and natural history of gutter-related type Ia endoleaks following ch-EVAR.

Association between report of insomnia and daytime functioning

ObjectivesThe relationship between reports of insomnia and daytime functioning was investigated using hierarchical regression. The presence or absence of a report of insomnia was the predictor of primary interest. A number of covariates were included in the model: demographic variables, health variables, and quantitative sleep parameters.MethodsData were collected from a community sample in the Memphis, Tennessee area. Data from 734 volunteers, ranging in age from 20 to 96 years were analyzed. The sample included 235 individuals who reported having chronic insomnia and 499 individuals who reported no sleep problems. Participants completed a 2-week sleep diary, a battery of daytime functioning questionnaires, and a medical disorders checklist. Demographic information was also collected. The daytime functioning assessment included the Beck Depression Inventory, the State-Trait Anxiety Inventory, the Epworth Sleepiness Scale, the Insomnia Impact Scale, and the Fatigue Severity Scale. The hierarchical regression model included four sets. The first three sets consisted of 18 variables capturing demographic, health, and sleep diary parameters. The fourth set included a single dichotomous variable representing the presence or absence of a report of insomnia.ResultsReports of insomnia were a significant predictor of all five daytime functioning measures, which is consistent with previous research. We also showed that reports of insomnia were able to uniquely explain a significant amount of variability in self-reported daytime functioning after controlling for demographics, health, and sleep diary variables. The pattern of individual variables that reached significance in the first three sets varied depending on which daytime functioning measure was predicted, however, age, the presence of pain, the presence of mental health problems, SOL, and WASO were the most commonly significant predictors of poor daytime functioning from these sets across measures.ConclusionsIndividuals’ perceptions of their sleep are related to differences in their reported daytime functioning, which are not accounted for by demographic factors, health surveys, or quantitative sleep assessments. Reports of insomnia may be related to a set of common cognitive factors among individuals who report having insomnia which cause them to be distressed with their sleep and increase their dissatisfaction with daytime functioning. Relevance of the findings to insomnia research and clinical management are discussed.     

Ethical and legal issues in the treatment of children with cancer. Our responsibilities to the parents, to the child, and to the other similarly afflicted children

The treating physician's ethical and legal responsibilities to a child with cancer often merge. On the one hand, there is a responsibility to the parents to keep them informed of the risks and benefits of proposed treatment modalities and to obtain their informed consent. On the other hand, there is an independent obligation to the child. Where consent is unreasonably withheld and the child's interests are jeopardized, it is the physician's responsibility to bring the matter to the courts.