Discriminatory GSRs.
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Discrimination, Psychological↗
Biomedical subjects
I Martin
Publications and source records attributed to I Martin.
A comprehensive educational program improves clinical outcome measures in inner-city patients with asthma.
BACKGROUND: Despite improved understanding of the pathophysiology of asthma, morbidity and mortality continue to rise, with disproportionate increases occurring among urban, indigent minorities. New approaches in the management of asthma are therefore necessary to reverse these dramatic and costly trends. OBJECTIVE: To determine if patients who are admitted to the hospital with acute asthma and receive inpatient education will have improved outpatient follow-up and clinical outcome measures compared with those receiving conventional care. METHODS: Patients enrolled in the study had a primary admission diagnosis of asthma and were between ages 18 and 45 years. Exclusion criteria included comorbid disease, inability to speak English, absence of a telephone in the primary residence, or pregnancy. Seventy-seven patients admitted from the emergency department with asthma were randomized to either the inpatient educational program (IEP) or routine care (control group). Patients in the IEP received asthma education, bedside spirometry, a telephone call 24 hours after discharge, and scheduled follow-up in an outpatient asthma program within 1 week of discharge. Those individuals randomized to the routine management group received conventional inpatient asthma care and routine follow-up. RESULTS: The patients enrolled in the IEP had a markedly higher follow-up rate compared with outpatient appointments (60% vs. 27%; P = .01) and significantly fewer emergency department visits (P = .04) and hospitalizations (P = .04) for asthma in the 6 months following IEP intervention, as compared with control patients. This represented a substantial cost savings to the managed care organization. CONCLUSION: Our study suggests that an IEP in the treatment of indigent, inner-city patients hospitalized with asthma reduces the need for subsequent emergent care and improves outpatient follow-up in a cost-effective manner.
Acute Disease↗
Enhanced cartilage tissue engineering by sequential exposure of chondrocytes to FGF-2 during 2D expansion and BMP-2 during 3D cultivation.
Bovine calf articular chondrocytes, either primary or expanded in monolayers (2D) with or without 5 ng/ml fibroblast growth factor-2 (FGF-2), were cultured on three-dimensional (3D) biodegradable polyglycolic acid (PGA) scaffolds with or without 10 ng/ml bone morphogenetic protein-2 (BMP-2). Chondrocytes expanded without FGF-2 exhibited high intensity immunostaining for smooth muscle alpha-actin (SMA) and collagen type I and induced shrinkage of the PGA scaffold, thus resembling contractile fibroblasts. Chondrocytes expanded in the presence of FGF-2 and cultured 6 weeks on PGA scaffolds yielded engineered cartilage with 3.7-fold higher cell number, 4.2-fold higher wet weight, and 2.8-fold higher wet weight glycosaminoglycan (GAG) fraction than chondrocytes expanded without FGF-2. Chondrocytes expanded with FGF-2 and cultured on PGA scaffolds in the presence of BMP-2 for 6 weeks yielded engineered cartilage with similar cellularity and size, 1.5-fold higher wet weight GAG fraction, and more homogenous GAG distribution than the corresponding engineered cartilage cultured without BMP-2. The presence of BMP-2 during 3D culture had no apparent effect on primary chondrocytes or those expanded without FGF-2. In summary, the presence of FGF-2 during 2D expansion reduced chondrocyte expression of fibroblastic molecules and induced responsiveness to BMP-2 during 3D cultivation on PGA scaffolds.
Actins↗
Human classical conditioning. The status of the CS.
Recent reports of failure to obtain blocking in human galvanic skin response (GSR) conditioning, together with our own equivocal results with eyelid conditioning, have motivated us to re-examine the status of the conditioned stimulus (CS) in human conditioning studies. The issues raised by compound stimuli, by contextual cues and occasion setting stimuli, and by cross-modal transfer are considered in the light of data from our laboratories. These data include observations on the interchangeability of stimulus modalities during acquisition, the use of varying information loads embedded in occasion setting displays, the comparison of alternative blocking designs and the analysis of response topography in relation to stimulus variability. They suggested that an adequate account of the CS in human conditioning studies must recognize that it is dynamically processed and reprocessed both during and after acquisition.
Arousal↗
Blocking observed in human eyelid conditioning.
The status of blocking in human eyelid conditioning was examined in a series of four experiments modelled on rabbit nictitating membrane (NMR) procedures to ensure comparability with the animal literature. The first three employed Tones and Lights as CSs and a preliminary experiment established equivalent salience of these stimuli. The fourth employed all light conditioned stimuli (CSs). Each of the experiments balanced order of presentation of blocked and non-blocked stimuli in extinction; each yielded reliable evidence of blocking tested in extinction. However, the blocking effects were attenuated or abolished in those groups receiving the to-be-blocked stimulus on the first trial in extinction. The results show blocking to be a relatively weak, easily disrupted phenomenon compared with rabbit studies. They suggest that rapid re-appraisal of stimulus significance plays a more important role in human subjects than has been observed in animal studies.
Arousal↗
The role of awareness in human conditioning.
The cognitive view of human classical conditioning is that Ss are active in thinking about the pattern of stimulus events which occurs, the demands of the situation, and the kind of responses which they give. A question crucially central to conditioning theory is whether these thoughts and expectations determine conditional responding. This paper reports on two conditioning and personality experiments, employing the standard procedure of a single cue CS-UCS schedule and masking task, which assess awareness of stimulus contingencies and demand characteristics by means of a postexperimental questionnaire. Results were quite clear in showing no significant relationship between measures of awareness and eyelid conditioning.
Adolescent↗
"Extending the Rescorla-Wagner theory to account for transswitching" by H. Lachnit and H.D. Kimmel.
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Animals↗
70+ and going strong: Ed and Irene Martin, hosts for a new age.
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Aged↗
Dynamic cell seeding of polymer scaffolds for cartilage tissue engineering.
Cell seeding of three-dimensional polymer scaffolds is the first step of the cultivation of engineered tissues in bioreactors. Seeding requirements of large scaffolds to make implants for potential clinical use include: (a) high yield, to maximize the utilization of donor cells, (b) high kinetic rate, to minimize the time in suspension for anchorage-dependent and shear-sensitive cells, and (c) high and spatially uniform distribution of attached cells, for rapid and uniform tissue regeneration. Highly porous, fibrous polyglycolic acid scaffolds, 5-10 mm in diameter and 2-5 mm thick, were seeded with bovine articular chondrocytes in well-mixed spinner flasks. Essentially, all cells attached throughout the scaffold volume within 1 day. Mixing promoted the formation of 20-32-micron diameter cell aggregates that enhanced the kinetics of cell attachment without compromising the uniformity of cell distribution. The kinetics and possible mechanisms of cell seeding were related to the formation of cell aggregates by a simple mathematical model that can be used to optimize seeding conditions for cartilage tissue engineering.
Animals↗
Producing prefabricated tissues and organs via tissue engineering.
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Animals↗
Bone and cartilage tissue engineering for facial reconstructive surgery.
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Animals↗
Method for quantitative analysis of glycosaminoglycan distribution in cultured natural and engineered cartilage.
Cartilage tissue engineering can provide a valuable tool for controlled studies of tissue development. As an example, analysis of the spatial distribution of glycosaminoglycans (GAG) in sections of cartilaginous tissues engineered under different culture conditions could be used to correlate the effects of environmental factors with the structure of the regenerated tissue. In this paper we describe a computer-based technique for quantitative analysis of safranin-O stained histological sections, using low magnification light microscopy images. We identified a parameter to quantify the intensity of red color in the sections, which in turn was proportional to the biochemically determined wet weight fraction of GAG in corresponding tissue samples, and to describe the spatial distribution of GAG as a function of depth from the section edge. A broken line regression model was then used to determine the thickness of an external region, with lower GAG fractions, and the spatial rate of change in GAG content. The method was applied to the quantitation of GAG distribution in samples of natural and engineered cartilage, cultured for 6 weeks in three different vessels: static flasks, mixed flasks, and rotating bioreactors.
Animals↗
What studies of fusion peptides tell us about viral envelope glycoprotein-mediated membrane fusion (review).
This review describes the numerous and innovative methods used to study the structure and function of viral fusion peptides. The systems studied include both intact fusion proteins and synthetic peptides interacting with model membranes. The strategies and methods include dissecting the fusion process into intermediate stages, comparing the effects of sequence mutations, electrophysiological patch clamp methods, hydrophobic photolabelling, video microscopy of the redistribution of both aqueous and lipophilic fluorescent probes between cells, standard optical spectroscopy of peptides in solution (circular dichroism and fluorescence) and attenuated total reflection-Fourier transform infrared spectroscopy of peptides bound to planar bilayers. Although the goal of a detailed picture of the fusion pore has not been achieved for any of the intermediate stages, important properties useful for constraining the development of models are emerging. For example, the presence of alpha-helical structure in at least part of the fusion peptide is strongly correlated with activity; whereas, beta-structure tends to be less prevalent, associated with non-native experimental conditions, and more related to vesicle aggregation than fusion. The specific angle of insertion of the peptides into the membrane plane is also found to be an important characteristic for the fusion process. A shallow penetration, extending only to the central aliphatic core region, is likely responsible for the destabilization of the lipids required for coalescence of the apposing membranes and fusion. The functional role of the fusion peptides (which tend to be either nonpolar or aliphatic) is then to bind to and dehydrate the outer bilayers at a localized site; and thus reduce the energy barrier for the formation of highly curved, lipidic 'stalk' intermediates. In addition, the importance of the formation of specific, 'higher-order' fusion peptide complexes has also been shown. Recent crystallographic structures of core domains of two more fusion proteins (in addition to influenza haemagglutinin) has greatly facilitated the development of prototypic models of the fusion site. This latter effort will undoubtedly benefit from the insights and constraints gained from the studies of fusion peptides.
Amino Acid Sequence↗
Implementation of WHO/ISH Guidelines: role and activities of WHO.
Cardiovascular disease (CVD) is, for most adults, the biggest risk to life. Hypertension is the most common CVD affecting large proportions of adults in most populations throughout the world. Although cost-effective technologies for hypertension management are available, the level of hypertension awareness and treatment in the population at risk is not satisfactory. It is estimated that, worldwide, there are at least 500 million people with hypertension not receiving appropriate treatment who would require immediate intervention. Thus, community-based hypertension control represents a great challenge for all societies. Hypertension management guidelines have the potential to improve hypertension management practice and even public education. In order to increase its impact, however, an implementation strategy is needed that includes advocacy, dissemination, training and evaluation as its major components.
Adult↗
Glucocorticoid response and adrenal lipid peroxidation in rats submitted to chronic hypobaric hypoxia.
The well known physiological changes that occur in adaptation to chronic hypobaric hypoxia (CHH) prevent the fall in arterial blood oxygen pressure below normal limits but neither the ventilatory nor the circulatory adaptation are able to maintain a normal capillary blood pO2. We report here our findings on adrenal histology, function, and lipid peroxidation in intact and castrated rats of both sexes submitted to twelve weeks of adaptation to 4,400 m simulated altitude. In the CHH rats hematocrit was increased; adrenal weight was increased in males and decreased in castrated females. Adrenal histology and histochemistry were normal. Corticosterone level and uric acid were unchanged except in castrated animals: corticosterone was decreased in males and increased in females. Uric acid was increased in castrated males, the only group in which adrenal lipid peroxidation was unaffected by castration. In the remaining groups, it was diminished compared to their intact controls. Intact normoxic males showed a significant direct correlation between plasmatic lipoperoxidation products (TBA-reactive substances) and uric acid (r = 0.961), which disappeared under hypoxia or with castration. Sex related differences were found in hematocrit and adrenal weight responses. The presence of androgens was involved in the adaptative response of cortical and reticular histometry, lipid peroxidation, and corticosterone level. These results do not support Selye's hypothesis of exhausted adrenal glands in chronic stages of adaptation and suggest that a proper relation between adrenal and gonadal steroids hormones is essential for systemic and tissular responses to diminished oxygen supply.
Adaptation, Physiological↗
Changes in the renin-angiotensin-aldosterone system in 2 kidney -2 clip Goldblatt hypertensive rats of both sexes submitted to chronic hypobaric hypoxia.
The effect of chronic hypobaric hypoxia (CHH) on the development of 2k-2c Goldblatt renovascular hypertension has been analyzed in rats of both sexes. Results have shown lower values of blood pressure (BP) in all the animals exposed to CHH compared with their normoxic control (P < 0.001). Haematocrit was increased by adaptation to CHH (P < 0.001), and was larger in male than in female hypoxic rats, both normotensive (P < 0.05) and hypertensive (P < 0.01). Plasma renin activity was higher in normoxic and hypoxic hypertensive female rats than in their normotensive controls (P < 0.05). Plasma angiotensinogen concentration was higher in normoxic control male rats than in all the other groups. This difference disappeared after adaptation to CHH or development of hypertension. Plasma aldosterone concentration was lowest in normoxic control male rats and the difference also disappeared after CHH or renal ischemia. Present data indicate that CHH blunts the hypertensive response to bilateral renal ischemia in male and female rats. Sexual differences related to the mechanisms that could be involved in hypertension development have been observed. The renin-angiotensin-aldosterone system might be modulated by gonadal hormones during the development of hypertension.
Aldosterone↗
Uniform tissues engineered by seeding and culturing cells in 3D scaffolds under perfusion at defined oxygen tensions.
In this work, we assessed whether culture of uniformly seeded chondrocytes under direct perfusion, which supplies the cells with normoxic oxygen levels, can maintain a uniform distribution of viable cells throughout porous scaffolds several milimeters in thickness, and support the development of uniform tissue grafts. An integrated bioreactor system was first developed to streamline the steps of perfusion cell seeding of porous scaffolds and perfusion culture of the cell-seeded scaffolds. Oxygen tensions in perfused constructs were monitored by in-line oxygen sensors incorporated at the construct inlet and outlet. Adult human articular chondrocytes were perfusion-seeded into 4.5 mm thick foam scaffolds at a rate of 1 mm/s. Cell-seeded foams were then either cultured statically in dishes or further cultured under perfusion at a rate of 100 microm/s for 2 weeks. Following perfusion seeding, viable cells were uniformly distributed throughout the foams. Constructs subsequently cultured statically were highly heterogeneous, with cells and matrix concentrated at the construct periphery. In contrast, constructs cultured under perfusion were highly homogeneous, with uniform distributions of cells and matrix. Oxygen tensions of the perfused medium were maintained near normoxic levels (inlet congruent with 20%, outlet > 15%) at all times of culture. We have demonstrated that perfusion culture of cells seeded uniformly within porous scaffolds, at a flow rate maintaining a homogeneous oxygen supply, supports the development of uniform engineering tissue grafts of clinically relevant thicknesses.
Adult↗
Bi-zonal cartilaginous tissues engineered in a rotary cell culture system.
In this study, we aimed at validating a rotary cell culture system (RCCS) bioreactor with medium recirculation and external oxygenation, for cartilage tissue engineering. Primary bovine and human culture-expanded chondrocytes were seeded into non-woven meshes of esterified hyaluronan (HYAFF-11), and the resulting constructs were cultured statically or in the RCCS, in the presence of insulin and TGFbeta3, for up to 4 weeks. Culture in the RCCS did not induce significant differences in the contents of glycosaminoglycans (GAG) and collagen deposited, but markedly affected their distribution. In contrast to statically grown tissues, engineered cartilage cultured in the RCCS had a bi-zonal structure, consisting of an outgrowing fibrous capsule deficient in GAG and rich in collagen, and an inner region more positively stained for GAG. Structurally, trends were similar using primary bovine or expanded human chondrocytes, although the human cells deposited inferior amounts of matrix. The use of the presented RCCS, in conjunction with the described medium composition, has the potential to generate bi-zonal tissues with features qualitatively resembling the native meniscus.
Adult↗