Myocardial resistance assessed by guidewire-based pressure-temperature measurement: in vitro validation.

By injecting a few cubic centimeters of saline into the coronary artery and using thermodilution principles, mean transit time (T(mn)) of the injectate can be calculated and is inversely proportional to coronary blood flow. Because microvascular resistance equals distal coronary pressure (P(d)) divided by myocardial flow, the product P(d). T(mn) provides an index of myocardial resistance (IMR). In this in vitro study in a physiologic model of the coronary circulation, we compared IMR to true myocardial resistance (TMR) at different degrees of myocardial resistance and at different degrees of epicardial stenosis. Absolute blood flow was varied from 42 to 203 ml/min and TMR varied from 0.39 to 1.63 dynes. sec/cm(5). Inverse mean transit time correlated well to absolute blood flow (R(2) = 0.93). Furthermore, an excellent correlation was found between IMR and TMR (R(2) = 0.94). IMR was independent on the severity of epicardial stenosis and thus specific for myocardial resistance. Thus, using one single guidewire, both fractional flow reserve and IMR can be measured simultaneously as indexes of epicardial and microvascular disease, respectively, enabling separate assessment of both coronary arterial and microvascular disease.     

Second primary tumors involving non-small cell lung cancer: prevalence and its influence on survival

OBJECTIVES: Patients with lung cancer have a relative high risk for second primary cancers. We studied the prevalence of second primary tumors in patients with a diagnosis of non-small cell lung cancer (NSCLC) in their history or at follow-up. Furthermore, we studied survival in subgroups of those patients. METHODS AND PATIENTS: Retrospectively, 860 patients with NSCLC that had been diagnosed in the period from January 1, 1990, to December 31, 1999, were evaluated for second primary cancers either in their history or in the follow-up period. The patients were divided into the following four groups: group I, patients with another primary tumor detected in the follow-up period (n = 44); group II, patients with another primary tumor in their history (n = 148); group III, patients with no other primary tumor found in their history or at follow-up (n = 634); and group IV, patients with more than one other primary tumor in found in their history or at follow-up (n = 34). RESULTS: The most frequently diagnosed double tumors were located in the lungs, the head and neck region, and the urinary tract. The interval between another malignancy as the first tumor (group II, 83 months) and NSCLC as the second malignancy was significantly longer than vice versa (group I, 14.5 months; p < 0.05). In > 80% of patients, the second primary tumors were diagnosed within 1 year after NSCLC was diagnosed. The 5-year survival rate is significantly better for patients with more than two primary malignancies compared to patients without two primary malignancies and patients with one other tumor in their history (p = 0.004 and 0.012, respectively). The 5-year survival rate in patients with a second tumor in the follow-up period was better than in patients without any other second tumor (p = 0.029). As the TNM stage and therapy were comparable in all subgroups, it could not be used as explanation for the difference in survival rates. CONCLUSION: In 25% of patients, additional tumors that were NSCLC were diagnosed either in their history or in the follow-up period. The majority of second tumors following NSCLC are diagnosed within 1 year. Nevertheless, patients with a second tumor tend to have an overall better survival rate than patients without second primaries, suggesting different growth habits.     

The changing epidemiology of malaria in Ifakara Town, southern Tanzania

Between 1995 and 2000 there were marked changes in the epidemiology of malaria in Ifakara, southern Tanzania. We documented these changes using parasitological and clinical data from a series of community- and hospital-based studies involving children up to the age of 5 years. There was a right shift and lowering in the age-specific parasite prevalence in the community-based cohort studies. The incidence of clinical malaria in placebo-receiving infants in additional study cohorts dropped from 0.8 in 1995 to 0.43 episodes per infant per year in 2000, an incidence rate ratio of 0.53 (95% confidence interval: 0.404, 0.70, P<0.0001). At the same time, there was an increase in the total number of malaria admissions and a marked right shift in the age pattern of these admissions (median age in 1995 1.55 years vs. 2.33 in 2000, P<0.0001). However, the burden of malaria deaths remained in infants. We discuss how these dramatic changes in the epidemiology of malaria may have arisen from the use of currently available malaria control tools. Caution is required in the interpretation of hospital-based data as it is likely to underestimate the impact of anaemia on mortality in the community, where most paediatric deaths occur. Even in low/moderate malaria transmission settings, where older children suffer most malaria episodes, targeting effective malaria control at infants may produce important reductions in infant mortality caused by malaria.     

三叶因子与胃黏膜保护的研究进展

三叶因子家族是一群主要由胃肠道黏液细胞分泌的小分子多肽.其共同特征为均含一特殊的P结构域及三叶状结构.这种稳定的结构使三叶因子家族具有明显的抗蛋白酶水解、酸消化及耐热特性,因而能在消化道复杂的环境中保持生物活性.目前在哺乳动物体内发现的有pS2/TFF1、SP/TFF2和ITF/TFF3三种,它们具有黏膜保护与修复、肿瘤抑制、信号传导、调节细胞凋亡等功能.本文阐述了三叶因子家族发现的历史,并初步探讨了其作用.同时也对三叶因子受体这一热点的研究现状进行总结.     

Problematic Alcohol Use Among Individuals with HIV: Relations with Everyday Memory Functioning and HIV Symptom Severity

Problematic alcohol use has been shown to negatively impact cognitive functions germane to achieving optimal HIV health outcomes. The present study, a secondary data analysis, examined the impact of problematic alcohol use on aspects of everyday memory functioning in a sample of 172 HIV-infected individuals (22 % female; M _age = 48.37 years, SD = 8.64; 39 % Black/non-Hispanic). Additionally, we tested whether self-reported memory functioning explained the relation between problematic alcohol use and HIV symptom severity. Results indicated that problematic patterns of alcohol use were associated with lower total memory functioning, retrieval (e.g., recall-difficulty) and memory for activity (e.g., what you did yesterday) and greater HIV symptom severity. Memory functioning mediated the relation between problematic alcohol use and HIV symptom severity. However, the direction of this relation was unclear as HIV symptom severity also mediated the relation between problematic alcohol use and memory functioning. Findings highlight the importance of integrated care for HIV and alcohol use disorders and suggest that routine alcohol and cognitive screenings may bolster health outcomes among this vulnerable population.     

Bexarotene increases uptake of radioiodide in metastases of differentiated thyroid carcinoma

OBJECTIVE: Treatment options for metastases of differentiated thyroid carcinoma (DTC) are limited due to decreased uptake of radioiodide (I-131). Therefore, strategies to improve I-131 uptake are mandatory. It has been suggested that retinoids have beneficial effects on iodide uptake in vitro and in humans. However, to date, only studies with 13-cis-retinoic acid have been performed in humans. We therefore decided to study the effects of 6 weeks of treatment with the retinoid X receptor activator bexarotene on I-131 uptake in patients with metastatic DTC. DESIGN: Open prospective intervention study. METHODS: Twelve patients with metastases of DTC, with insufficient uptake of I-131, received 6 weeks of treatment with 300 mg bexarotene/day. Prior to, and after this intervention, I-131 uptake was measured by whole-body scintigraphy and single photon emission tomography (SPECT) 3 days after 185 MBq I-131. Diagnostic imaging was preceded by two consecutive injections of recombinant human TSH. RESULTS: Bexarotene treatment induced I-131 uptake in metastases of 8 out of 11 patients (one patient died for reasons not related to the study). However, uptake was only discernable at SPECT and had incomplete matching with metastases as visualized by CT scanning. CONCLUSIONS: Bexarotene partially restores I-131 uptake in metastases of DTC. The clinical relevance of this observation may be limited due to the differential responses of the different metastases within each patient and the low intensity of I-131 uptake.     

Microbial community in a sediment-hosted CO2 lake of the southern Okinawa Trough hydrothermal system

Increasing levels of CO2 in the atmosphere are expected to cause climatic change with negative effects on the earth's ecosystems and human society. Consequently, a variety of CO2 disposal options are discussed, including injection into the deep ocean. Because the dissolution of CO2 in seawater will decrease ambient pH considerably, negative consequences for deep-water ecosystems have been predicted. Hence, ecosystems associated with natural CO2 reservoirs in the deep sea, and the dynamics of gaseous, liquid, and solid CO2 in such environments, are of great interest to science and society. We report here a biogeochemical and microbiological characterization of a microbial community inhabiting deep-sea sediments overlying a natural CO2 lake at the Yonaguni Knoll IV hydrothermal field, southern Okinawa Trough. We found high abundances (>10(9) cm(-3)) of microbial cells in sediment pavements above the CO2 lake, decreasing to strikingly low cell numbers (10(7) cm(-3)) at the liquid CO2/CO2-hydrate interface. The key groups in these sediments were as follows: (i) the anaerobic methanotrophic archaea ANME-2c and the Eel-2 group of Deltaproteobacteria and (ii) sulfur-metabolizing chemolithotrophs within the Gamma- and Epsilonproteobacteria. The detection of functional genes related to one-carbon assimilation and the presence of highly 13C-depleted archaeal and bacterial lipid biomarkers suggest that microorganisms assimilating CO2 and/or CH4 dominate the liquid CO2 and CO2-hydrate-bearing sediments. Clearly, the Yonaguni Knoll is an exceptional natural laboratory for the study of consequences of CO2 disposal as well as of natural CO2 reservoirs as potential microbial habitats on early Earth and other celestial bodies.     

Clarithromycin suppresses IL-13-induced goblet cell metaplasia via the TMEM16A-dependent pathway in guinea pig airway epithelial cells

Background

Transmembrane protein 16A (TMEM16A) is associated with mucus secretion and ion transport in asthma. Clarithromycin (CAM) is reported to inhibit IL-13-induced goblet cell metaplasia. However, the effect of CAM on TMEM16A function and expression remains unclear.