Numerical Simulation and Experimental Validation of Blood Flow in Arteries with Structured-Tree Outflow Conditions

Blood flow in the large systemic arteries is modeled using one-dimensional equations derived from the axisymmetric Navier–Stokes equations for flow in compliant and tapering vessels. The arterial tree is truncated after the first few generations of large arteries with the remaining small arteries and arterioles providing outflow boundary conditions for the large arteries. By modeling the small arteries and arterioles as a structured tree, a semi-analytical approach based on a linearized version of the governing equations can be used to derive an expression for the root impedance of the structured tree in the frequency domain. In the time domain, this provides the proper outflow boundary condition. The structured tree is a binary asymmetric tree in which the radii of the daughter vessels are scaled linearly with the radius of the parent vessel. Blood flow and pressure in the large vessels are computed as functions of time and axial distance within each of the arteries. Comparison between the simulations and magnetic resonance measurements in the ascending aorta and nine peripheral locations in one individual shows excellent agreement between the two. © 2000 Biomedical Engineering Society. PAC00: 8719Uv     

Indoor mite allergens in patients with respiratory allergy living in Porto, Portugal

We investigated the levels of mite allergens (Der p 1, Der f 1, Der 2, and Lep d 1) in dust samples from the homes of 59 patients with asthma, 36 sensitized to house-dust mites (HDM) and 23 to grass pollen (controls), living in Porto, northern Portugal. The relationship between exposure and sensitization to HDM and the influence of housing conditions on mite-allergen levels were also evaluated. Der p 1 (median 9.2 μg/g) and Der 2 (4.6 μg/g) were the main allergens, while Der f 1 and Lep d 1 levels were always <1 μg/g dust and undetectable in 11% and 47% of samples, respectively. All HDM-sensitized asthmatics were exposed to Der p 1 levels >2 μg/g and their homes contained significantly higher levels of Der p 1 (median 12.5 vs 6.4 μg/g; P=0.008) and Der 2 (6.2 vs 3.0 μg/g; P=0.004) when compared to the control group. A significant correlation was observed between the exposure to Der p 1 and the wheal area at skin testing with the Dermatophagoides pteronyssinus (Dp) extract (P=0.01) as well as with serum specific IgE levels to Dp (P=0.03). Patients with higher levels of serum specific IgE (≥17.5 HRU/ml) were also more frequently exposed to Der p 1 levels ≥10 (μg/g (P=0.002). Old homes, presence of carpets, and signs of dampness were conditions associated with significantly higher levels of mite allergens. In conclusion, we found high levels of Der p 1 and Der 2 particularly in the homes of HDM-sensitized patients and we confirm the relationship between exposure and sensitization to HDM, assessed by both in vivo and in vitro methods. In addition to a favorable outdoor climate, we found in our region housing conditions propitious to mite growth, suggesting that specific geographic characteristics must also be taken into account for the correct planning of mite-avoidance measures.     

Behavioral phenotyping of mice in pharmacological and toxicological research

The evaluation of behavioral effects is an important component for the in vivo screening of drugs or potentially toxic compounds in mice. Ideally, such screening should be composed of monitoring general health, sensory functions, and motor abilities, right before specific behavioral domains are tested. A rational strategy in the design and procedure of testing as well as an effective composition of different well-established and reproducible behavioral tests can minimize the risk of false positive and false negative results in drug screening. In the present review we describe such basic considerations in planning experiments, selecting strains of mice, and propose groups of behavioral tasks suitable for a reliable detection of differences in specific behavioral domains in mice. Screening of general health and neurophysiologic functions (reflexes, sensory abilities) and motor function (pole test, wire hang test, beam walking, rotarod, accelerod, and footprint) as well as specific hypothesis-guided testing in the behavioral domains of learning and memory (water maze, radial maze, conditioned fear, and avoidance tasks), emotionality (open field, hole board, elevated plus maze, and object exploration), nociception (tail flick, hot plate), psychiatric-like conditions (porsolt swim test, acoustic startle response, and prepulse inhibition), and aggression (isolation-induced aggression, spontaneous aggression, and territorial aggression) are described in further detail. This review is designed to describe a general approach, which increases reliability of behavioral screening. Furthermore, it provides an overview on a selection of specific procedures suitable for but not limited to behavioral screening in pharmacology and toxicology.     

Hyperplastic foci in chronic liver disease: Their proliferative activity assessed by nucleolar organizing region

In the cirrhotic and precirrhotic liver, there may be small foci with increased cellularity and amphophilic cytoplasm. These are microscopic lesions that do not form macroscopically detectable nodules, which differ from the macroscopically apparent nodules of dysplastic nodules. In the present study, we assessed the proliferating activity of 12 hyperplastic foci in 11 patients with cirrhosis or chronic hepatitis, by staining for agyrophilic nucleolar organizing regions (AgNOR). The mean AgNOR count per nucleus in the hyperplastic foci ranged from 0.96 to 1.36 (mean, 1.13; SD 0.12), and from 0.81 to 1.06 (mean, 0.94; SD 0.08) in the controls. The AgNOR count In the hyperplastic foci was significantly higher than that In the controls (P> 30.01). Small hyperplastic foci show Increased proliferative activity. Further study on these foci is required to clarify their relation to hepatocarcinogenesis.     

Early and advanced gastric cancer during follow-up of apparently benign gastric ulcer: significance of the presence of epithelial dysplasia

One hundred and forty-four patients with apparently benign gastric ulcer were endoscopically followed up in order to evaluate the outcome of the lesion. Particular attention was given to: (a) detect possible delay in diagnosing gastric cancer; (b) ascertain the frequency of association with epithelial dysplasia; (c) establish the role of markers, such as serum pepsinogen group I (PGI), and gastric juice CEA in predicting gastric ulcer evolution. Endoscopic and bioptic check-ups were carried out during the first year at 3, 6 and 12 months after endoscopic healing of the ulcer, and then at every symptomatic recurrence. Ten patients (6.9%) were found to present histological evidence of malignancy (within 3 months in six cases, between 6 and 12 months in three cases, and after 41 months in the rest). Four cases were early gastric cancers, and six had shown dysplastic changes of the mucosa at the edge or scar of the ulcer. Serum PGI levels were not significantly different in gastric cancer patients, while gastric juice CEA levels were sharply increased compared to those of gastric ulcer patients: nine out of ten patients had values above normal range. These data suggest that: (a) there may be some delay in diagnosing gastric carcinoma, and gastric ulcer patients should be controlled routinely more than once; (b) the presence of dysplasia indicates the need for prolonged follow-up, because of the high risk of association with or evolution into gastric cancer, and because of the higher number of early gastric cancer detections that this protocol allows; (c) further support in monitoring patients "at risk" may be afforded by gastric juice CEA determination.     

Prevalence and distribution of gingivitis and dental caries in children aged 6–12 years in Brisbane primary schools

A study of caries experience and gingivitis prevalence in 6-, 9- and 12-yr-old children attending primary schools in Brisbane was undertaken in November/December 1983. Children from high socioeconomic level (SEL) schools exhibited lower dmft and DMFT scores at all ages. At age 6 yr the proportion of children with caries-free primary dentitions was for high SEL Schools 70%, for middle SEL schools 52% and for low SEL Schools 23%. At 12 yr DMFT scores were 1.8 (high), 2.1 (middle) and 3.3 (low). Similar differences in gingivitis prevalence occurred, children from high SEL schools displaying a much lower proportion of bleeding sites than those from middle and low SEL schools. For selection of children at "high risk" to gingival disease for intensive prevention programmes, an increased emphasis on probing techniques is indicated to achieve diagnostic consistency.     

Stretched attend posture,a non-social form of ambivalence,is sensitive to a conflict-reducing drug action

Based upon the ethological element stretched attend to a conspecific, which reflects ambivalence between approach and avoidance in a social context, a simple, non-social behavioral method for studying conflict behavior in mice was investigated. Thus, stretched attend posture (SAP) and other behavioral acts were measured in untreated or drug-treated mice which were individually placed on a perforated platform previously rubbed with foreign male urine and boluses. In naive, untreated mice, the occurrence of SAP was partly housing- and lighting-dependent. After repeated exposure to the test situation, untreated mice showed less SAP, whereas static behavior (immobility and activity at rest) was increased. After single oral treatment with diazepam, clobazam or phenobarbital, SAP was reduced, whereas static behavior or going forwards in SAP was increased. Chlorpromazine and imipramine did not influence SAP. In naive mice, single IP injection of pentylenetetrazol did not significantly increase SAP. The similarity in the behavioral response between experienced, untreated mice and naive animals treated with diazepam, clobazam, or phenobarbital suggests that drug-treated mice behaved as if they were already familiar with the test situation. The latter drug-induced changes are consistent with data obtained in animal models which are based upon the measurement of behavioral inhibition. Under the present test conditions, pentylenetetrazol did not show anxiogenic properties. Nevertheless, the SAP test, based primarily on the measurement of the ambivalence element, offers a simple procedure for examining the conflict-reducing properties of drugs, dispensing with the need of noxious stimuli or prior training.Some of these results were presented at the 15th Annual USGEB/USSBE Meeting in Fribourg, Switzerland (17–18 March 1983) and, published in abstract form in Experientia (1983) 39(6):681–682     

泽漆水提物对香烟烟雾诱导小鼠慢性阻塞性肺病及肺组织癌前病变相关蛋白的影响

目的：探究泽漆水提物对香烟烟雾(CS)所致的慢性阻塞性肺病(COPD)的保护作用及肺组织癌前病变相关蛋白的影响。方法：通过建立CS所致的COPD小鼠模型(60只),随机分为正常组、模型组、阳性药组(地塞米松2 mg·kg^-1)及泽漆水提物低、中、高剂量组(1.875、3.75、7.5 g·kg^-1)。采用高效液相色谱法(HPLC)测定泽漆水提物中相关成分;动物肺功能仪检测小鼠呼气末期暂停(EEP)、气道阻力(Penh)、50%肺活量呼吸时的呼气流量(EF50)等肺功能指标变化;高通量液相蛋白芯片技术检测小鼠肺泡灌洗液(BALF)中白细胞介素(IL)-2、IL-5、IL-18、IL-17A、IL-27等炎性因子水平变化;苏木素-伊红(HE)染色检测小鼠肺组织的病理变化;比色法测定小鼠肺组织中的丙二醛(MDA)、髓过氧化物酶(MPO)及谷胱甘肽过氧化物酶(GSH-Px)含量变化;实时荧光定量聚合酶链式反应(Real-time PCR)检测肿瘤坏死因子-α(TNF-α)、转化生长因子-β(TGF-β)、基质金属蛋白酶(MMP)-2、MMP-9及MM...     

Characteristics and Risk Factors of Hospitalized and Nonhospitalized COVID-19 Patients,Atlanta, Georgia,USA, March–April 2020

We compared the characteristics of hospitalized and nonhospitalized patients who had coronavirus disease in Atlanta, Georgia, USA. We found that risk for hospitalization increased with a patient’s age and number of concurrent conditions. We also found a potential association between hospitalization and high hemoglobin A1c levels in persons with diabetes.     

Associations between weather conditions and physical activity and sedentary time in children and adolescents: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to investigate the associations between weather conditions and physical activity (PA) and sedentary time (ST) in children and adolescents. A systematic search of six databases identified 11,816 articles, of which 26 studies were included in the review. Several weather conditions were included, such as rainfall, temperature, wind speed, day length, sunlight, humidity, snowfall, and clouds. Meta-analyses showed that higher temperatures were associated with more moderate-to-vigorous PA, while lower temperature and heavily rainfall was associated with longer ST. Children and adolescents showed more PA and less ST during favorable weather conditions. Future longitudinal and intervention studies on PA and ST should focus on how weather conditions promote or hinder these behaviors.