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We hypothesized that heat shock protein 90 (HSP90) expression would be increased in vascular tissue exposed to a hypoxic stress that resulted in altered contractile function. We tested this hypothesis by subjecting excised rat aortic rings to a hypoxic stress that has been shown to reduce contractile force induced by arginine vasopressin (PO2 ≈50 mm Hg for 1 h) and determining the effect on HSP90 expression. Concentration-response curves were determined for control and hypoxic excised rat aortic rings exposed to norepinephrine (n = 8) or KCl (n = 8). Hypoxia reduced the force generated in response to the highest concentration of each agonist. HSP90 expression was evaluated by immunoblotting (n = 6) and immunohistochemistry (n = 7). Both methods documented increased expression of HSP90 in hypoxic aortae as compared to controls. HSP90 expression was increased within the cytoplasm and in conjunction with the nucleus of vascular smooth muscle cells in the tunica media and also within vascular myointimal cells. We conclude that a hypoxic stress sufficient to induce contractile dysfunction increases HSP90 expression in rat aortic smooth muscle cells.

A device was designed to measure the change in optical density (/spl Delta/OD) of blood at selected wavelengths as a function of the concentration of optically absorbing multiple indicator dilution (MID) tracers. The optical MID (OMID) tracers selected for this measurement device and their corresponding wavelengths are the following: indocyanine green(ICG)-bound albumin measured at 820 nm, sulfhemoglobinated erythrocytes (Shb-RBC's) measured at 620 nm, and 1,2-propanediol measured at 9.55 /spl mu/m. Arterial blood from cannulated anesthetized dogs was circulated through an extracorporeal flow-through circuit which included this /spl Delta/OD measurement device. Calibration of the 820 nm and 620 nm channels produced r/sup 2/ of greater than 0.95 for the optical density-tracer mass regressions. The propanediol measurement channel (9.55 /spl mu/m) was also linearly calibrated. An in vivo optical MID study was performed and compared to a radioisotope MID study. Lung vascular permeability-surface area (PS) values calculated using the two methods were 5.76 and 5.73 mL/s. It is concluded that this OMID technique is an acceptable alternative to radioisotope MID studies. >

Pleural pressure was measured at end expiration in anesthetized rabbit using a rib capsule placed in the right fifth rib. Three groups of rabbits were studied in right and left lateral recumbency at least 8 weeks after surgery; rabbits hat had undergone left pneumonectomy (Px, n = 8), rabbits that had undergone left pneumonectomy with wax plombage (Px + W, n = 7), and sham-operated control rabbits (S, n = 6). In S, Px, and Px + W rabbits in the left lateral position (lung and capsule nondependently), pleural pressure was −2.11 ± 0.88 (mean ± SD), −2.65 ± 0.23, and −1.96 ± 0.55 cmH 2 O respectively. In S, Px and Px + W rabbits in the right lateral position (lung and capsule dependent), pleural pressure was 0.64 ± 0.22, 0.85 ± 1.42, and 0.48 ± 1.77 cmH 2 O respectively. In each position, pleural pressure did not differ among groups. This suggests that the compensatory increase in lung volume and reduced lung compliance following pneumonectomy in rabbits (Olson, J. Appl. Physiol. 74: 415–422, 1993) was not simply due to hyperinflation of the remaining lung.

Engineering educators and students are at the interface between biomedical engineering technology and the developing world. Through service learning efforts and organizations like Engineers Without Borders and Engineering World Health, engineers find themselves asking questions about ethics and standards as they relate to the developing world. The goal of this session is to begin a dialogue about ethics and standards for biomedical engineers working with people in the developing world and to start the process of developing guidelines that will inform their practice. This session will use a case-based and education-focused strategy to begin this dialogue. The session will utilize facilitators with expertise in these areas to discuss various case studies. They will attempt to address questions about biomedical engineering ethics and standards in the context of economic and logistical constraints. The output of this dialogue will be direct input to a workshop on biomedical engineering ethics and standards in the developing world and will be the foundation for a consensus for guidelines for engineers practicing in the developing world.

Acute lower respiratory infections are common and deadly in Central America. Nebulizers are relatively expensive medical devices that aerosolize medicine for inhalation into the lower respiratory tract. Senior design students at Marquette University have worked on low cost nebulizer designs that can be used in remote poor areas in Central America. These students' senior design experience has been unconventional. Problem identification and customer interviews have occurred during immersion trips to Central America. The project has been continued over several years with multiple groups. Service learning has been incorporated into the senior design course. Sustainability and other design related issues pertaining to the developing world were given a higher priority than other design parameters. The designs focused on the use of human power that can be implemented within the economic, technical, and medical constraints of the Central American market. Regulatory and ethical issues were also addressed. Students in these groups were exposed to many engineering design issues as well as issues of global health and social justice in Central America.

This paper presents a new method to determine the electromagnetic characteristics of slow release B1 relay, which is used in US railways. This relay operates few seconds after it is energized or de-energized. The slow operation of this relay is accomplished by short circuits loops around the magnetic core of the relay. The operation of the B1 relay is highly affected by electromagnetic characteristics of the relay, therefore, this research aimed to obtain the B-H or equivalently /spl lambda/-I curve of the relay core. Since the relay has short circuit loop around its core, it is not possible to obtain its /spl lambda/-I curve by conventional methods. Thus, different methods have been proposed, and finally the most efficient one is chosen and explained further in this paper.

One of the basic tasks in railway maintenance is inspection of the rail in order to detect defects. Rail defects have different properties and are divided into various categories with regard to the type and position of defects on the rail. This paper presents an approach for the detection of defects in rail based on wavelet transformation. Multi-resolution signal decomposition based on wavelet transform or wavelet packet provides a set of decomposed signals at distinct frequency bands, which contains independent dynamic information due to the orthogonality of wavelet functions. Wavelet transform and wavelet packet in tandem with various signal processing methods, such as autoregressive spectrum, energy monitoring, fractal dimension, etc., can produce desirable results for condition monitoring and fault diagnosis. Defect detection is based on decomposition of the signal acquired by means of magnetic coil and Hall sensors from the railroad rail, and then applying wavelet coefficients to the extracted signals. Comparing these extracted coefficients provides an indication of the healthy rail from the defective rail. Experimental results are presented for a healthy rail and some of the more common defects. Deviation of wavelet coefficients in the healthy rail case from the case with defects shows that it is possible to classify healthy rails from defective ones.

We estimated the magnitude of parenchymal interdependence in excised pig lungs by measuring small airway diameter during homogeneous and nonhomogeneous lung inflation, by comparing the ratio of the specific compliance of the lung (Cl) to the specific compliance of a single lung region (Cs) and by using a continuum mechanics analysis to estimate the pressure at the interface between a single lung region and the surrounding lung. We found that the diameter of airways in a single lung region increased when the lung was held at a transpulmonary pressure (Ptp) of 5, 10 or 15 cmH2O and pressure in the region was increased by up to Ptp + 15 cmH2O, indicating that the surrounding lung offered little resistance to expansion of the lung region. The ratio of Cl to Cs averaged 1.22 (n = 5 lungs), indicating that the parenchyma surrounding the lung region caused a small reduction in its distensibility. When the lung was held at a Ptp of 5 cmH2O, pressure at the interface was estimated to be 1.1, 0.8 and −1.9 cmH2O when pressure in the single lung region was 15, 10 and 0 cmH2O, respectively. The relatively small change in boundary pressure from pleural pressure as the region was inflated or deflated indicated that the mechanical interaction between adjacent lung regions was small. Taken together, these results confirm the prediction of a small interdependence effect as determined by measurements of the distensibility and distortability of the pulmonary parenchyma.

The volatile components produced by enzyme extracts from tomato fruit using amino acid substrates were analysed by gas and thin-layer chromatography. Alanine, leucine, and valine were among the best substrates. Extracts from red-ripe tomatoes were more active than those from green fruit. The products differed somewhat with each preparation and with the particular substrate used. Propanal was present in most reaction products especially when alanine was used as substrate. With enzymes from red-ripe fruit, alanine gave mainly carbonyl compounds while leucine and valine gave mainly alcohols. Mixed amino acids sometimes resulted in new volatile components. The mechanism appears to involve transamination.

The composition of tomato fruit at nine different stages of maturity was studied. The dry matter content decreased gradually, whereas the alcohol-soluble material and non-protein nitrogen increased with ripening. Total nitrogen decreased up to the large green stage and then increased during ripening. Starch accumulated until nearly the large green stage and then diminished rapidly. Of the two components of starch, amylose decreased much faster than amylopectin, and the ratios of amylopectin and amylose thus increased during ripening. Among the amino acids, glutamic acid was present in an exceptionally high concentration, and its concentration doubled during ripening. A concomitant decrease in the concentration of several other amino acids was noted. The possibility of amino acids serving as precursors for the synthesis of volatile aroma components in tomato is discussed.

低線量照射による果実蔬菜の貯蔵はかなり有望な面のあることが報告されているが, 照射に伴う組織の軟化, 特有な風味の変化など好ましくない問題点がまだ残されている。果実蔬菜の風味に対する放射線照射の影響を化学的面より研究した報告は少ない。リンゴ果実についてもMasseyら (1964) やPhillips (1960) の興味ある研究があるが, その風味に対する放射線照射効果については報告されていない。本実験はおもにデリシャスリンゴを用い, 照射による風味の悪化を揮発性成分の変化から追究するために行なったものである。実験材料は137Cs γ線 (2.5×104R/hr) によって20℃下で照射された。照射線量はO, 6.25×104, 1.25×105および1.0×106Rであった。揮発性成分はHeadspacevapor分析法によってガスクロマトグラフで分析した。無照射区のリンゴには二十数種の中性揮発性成分が検出され, リンゴ特有の風味を表わすと推定される二つの型のクロマトグラムが得られた。これらの無照射区のクロマトグラムと照射区のそれとを比較することによって照射リンゴの風味の変化の原因を検討した結果, 照射直後における風味の低下の原因の一つはある種の高沸点化合物の減少により, また貯蔵中におけるそれは貯蔵中の高沸点化合物の減少と無照射区にみられる低沸点化合物の生成が抑制されることにより起るものと推定した。

Fifteen distinct peaks were resolved from red-ripe tomato flavor extract by gas Chromatographic techniques. Except isobutanol, n -hexanol, and n -hexanal, concentrations of the volatile components in the field-grown tomatoes were higher than those in the greenhouse-grown tomatoes. Artificially ripened tomatoes contained less volatile components.

Strips of smooth muscle from the cervical tracheae of six adult male crab-eating monkeys (Macaca fascicularis) were studied in jacketed 25 ml organ baths filled with Krebs-bicarbonate solution maintained at 37 degrees C and gassed with 5% CO2 in oxygen. Isometric tissue tension increased in response to electrical field stimulation (18 V, 25 Hz, 0.5 msec), norepinephrine in the presence of propranolol, acetylcholine and histamine. Atropine abolished the contractile response to electrical stimulation. Tissues that were contracted with acetylcholine or pretreated with atropine then contracted with histamine relaxed when stimulated electrically. The relaxation was unaffected by propranolol but was abolished by tetrodotoxin. Isoproterenol relaxed tissues that were contracted with histamine, but failed to relax histamine-contracted tissues that had been pretreated with propranolol. Norepinephrine did not change isometric tension in untreated tissues or tissues pretreated with phentolamine. These results demonstrate the presence of excitatory and inhibitory nerves and noninnervated beta-adrenergic receptors in macaque trachealis. The excitatory nerves appear to be cholinergic. The inhibitory response to electrical stimulation is not mediated through muscarinic cholinergic or beta-adrenergic receptors. The inhibitory response to electrical field stimulation was likely mediated through nonadrenergic noncholinergic nerves.