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51.
Haas W Haberl B Syafruddin Idris I Kallert D Kersten S Stiegeler P;Syafruddin 《Parasitology research》2005,95(1):30-39
The infective third-stage larvae of the hookworms Necator americanus and Ancylostoma duodenale infect their human hosts by active skin invasion, but A. duodenale is in addition capable of oral infection. The behaviour of the larvae when crawling on surfaces has already been described. Here we analyse in various in vitro systems the other behavioural invasion phases: activation, penetration, and orientation within the host. The larvae normally remained in a motionless, energy-saving, resting posture. An activation to sinusoidal locomotion was stimulated in both species by similar cues such as touch, vibration, water currents, heat, light, and chemicals. Human breath in addition stimulated searching and waving (nictating) behaviour, which facilitates a change-over to the host. Activating cues in air streams were warmth and moisture; CO2 activated only in combination with warmth and/or moisture. Penetration behaviour in both species was stimulated by warmth and skin extracts. The stimulating components of skin extracts were fatty acids, but their stimulating characteristics differed from those inducing schistosome cercarial skin penetration. After penetration into agar substrates, both species showed thermo-orientation, but only A. duodenale followed gradients of serum. The directing serum cues were not amino acids and glucose (the supposed cues for schistosome blood vessel localization), but Ringers solution attracted the larvae. The host-finding and host-invasion behaviour of both hookworm species is well adapted to the invasion of the human skin, and there seems to be no particular adaptation of A. duodenale behaviour to the oral infection mode. Hookworm host-finding behaviour is not as complex as that of schistosome cercariae but seems well adapted to the ecological conditions in the transmission sites. 相似文献
52.
Kanjickal D Lopina S Evancho-Chapman MM Schmidt S Donovan D 《Journal of biomedical materials research. Part A》2005,74(3):454-460
A simple and effective technique of improving delivery of hydrophobic drugs from swellable systems is presented. Conventional methods of drug loading in hydrogel systems are limited by the characteristics of the pharmacological agent. The approach we present uses complexants to modulate drug release. Crosslinked poly(ethylene glycol) (PEG) hydrogels were synthesized, characterized, and used for vascular applications. The release of cyclosporine (CyA) from PEG hydrogels is significantly altered by the sterilization techniques. It was hypothesized that the release of CyA from PEG hydrogels can be modulated by using complexants. A cyclodextrin-CyA complex solution was prepared and used for drug loading. The sterilized PEG hydrogels that were loaded using the cyclodextrin-CyA complex solution had favorable release characteristics compared with the release from PEG hydrogels that were loaded using the conventional technique. Hence, drug release from swellable systems can be tailored by the application of this strategy. 相似文献
53.
Joncourt F Neuhaus B Jostarndt-Foegen K Kleinle S Steiner B Gallati S 《Human mutation》2004,23(4):385-391
Recently developed PCR systems offer online-monitoring of amplification and allow simple and reliable DNA quantification. We have used the LightCycler system to develop a simple and rapid method for direct identification of female carriers of deletions and duplications in the dystrophin gene. The challenge resides in the ability to identify the presence of a deleted or duplicated allele over the background contributed by the normal allele. Quantification is based on the determination of the ratio between potentially deleted/duplicated dystrophin exons and non-deleted/-duplicated reference exons using the unspecific dsDNA-dye SYBRgreen I. In a retrospective study, we evaluated our method in female relatives of DMD/BMD patients with known carrier status by comparative analysis of deleted or duplicated versus non-deleted/-duplicated exons. Carrier status was accurately attributed in 100% of cases, the mean ratios being 0.52+/-0.12 for deletion carriers (expected value: 0.5) and 1.56+/-0.18 for duplication carriers (expected value: 1.5) vs. 1.022+/-0.17 for non-carriers (expected value: 1.0). The method proved to be simple, rapid, reliable, and cost-effective. It may be used for direct determination of deletions/duplications in potential DMD/BMD carriers and may easily be adapted for other genetic conditions involving deletions and duplications. 相似文献
54.
Georg H. Eifert Stephanie E. Hodson Doreen R. Tracey L. Seville Kumar Gunawardane 《Journal of behavioral medicine》1996,19(4):385-399
Psychological features and complaints of persons presenting to medical settings with heart-focused anxiety and noncardiac chest pain are poorly understood. Comparing 20 healthy heart-anxious patients to cardiac and surgical inpatients and nonpatient controls, we found that healthy heart-anxious patients (a) were as afraid of chest pain and heart palpitations as inpatients with heart disease, (b) were as incapacitated by symptoms and using medical services as much as both inpatient groups; and (c) reported higher levels of cardiac disease conviction, heart awareness, and behaviors designed to protect their heart than surgical patients and nonpatients. Compared to all other groups, healthy heart-anxious patients reported more panic and other anxiety disorders, hypochondriacal beliefs, physical symptoms, obsessive-compulsive concerns, and negative affect. Following a hyperventilation test, heart-anxious patients also indicated more distressing symptoms and thoughts, and felt less safe and in control than surgical patients and nonpatients. Results support efforts for a timely recognition, diagnosis, and behavioral treatment of persons with heart-focused anxiety. 相似文献
55.
56.
Johnson JG Cohen P Kotler L Kasen S Brook JS 《Journal of consulting and clinical psychology》2002,70(5):1119-1128
Longitudinal data were used to investigate whether anxiety, depressive, disruptive, personality, or substance use disorders are associated with risk for the development of eating disorders during adolescence or early adulthood. Psychiatric disorders were assessed among 726 youths from a random community sample during adolescence and early adulthood. Depressive disorders during early adolescence were associated with elevated risk for the onset of eating disorders, dietary restriction, purging behavior, and recurrent weight fluctuations after preexisting eating problems and other psychiatric disorders were controlled statistically. Disruptive and personality disorders were independently associated with elevated risk for specific eating or weight problems. The present findings suggest that depressive disorders during early adolescence may contribute to the development of eating disorders during middle adolescence or early adulthood. 相似文献
57.
58.
Katharine J. Foster Stephanie Q. Zhang Stephen R. Braddock Rashmi Chikarmane Cirilo Sotelo‐Avila Jose Greenspon 《American journal of medical genetics. Part A》2019,179(5):817-821
Retinoic acid receptor beta (RARB) variants are heavily linked to pathologies of neural crest cell migration. The purpose of this report is to present a 23‐month‐old male with the previously described R387C RARB gain‐of‐function variant whose gastrointestinal issues and long‐term constipation lead to the discovery of colonic hypoganglionosis. This case further delineates the pattern of malformation associated with RARB variants. The findings are also consistent with the known etiology of aganglionic colon due to failed neural crest cell migration. 相似文献
59.
George Capone Mary Stephens Stephanie Santoro Brian Chicoine Peter Bulova Moya Peterson Joan Jasien Anna Jo Smith Down Syndrome Medical Interest Group Adult Health Workgroup 《American journal of medical genetics. Part A》2020,182(7):1832-1845
Adults with Down syndrome (DS) represent a unique population who are in need of clinical guidelines to address their medical care. Many of these conditions are of public health importance with the potential to develop screening recommendations to improve clinical care for this population. Our workgroup previously identified and prioritized co‐occurring medical conditions in adults with DS. In this study, we again performed detailed literature searches on an additional six medical conditions of clinical importance. A series of key questions (KQ) were formulated a priori to guide the literature search strategy. Our KQs focused on disease prevalence, severity, risk‐factors, methodologies for screening/evaluation, impact on morbidity, and potential costs/benefits. The available evidence was extracted, evaluated and graded on quality. The number of participants and the design of clinical studies varied by condition and were often inadequate for answering most of the KQ. Based upon our review, we provide a summary of the findings on hip dysplasia, menopause, acquired cardiac valve disease, type 2 diabetes mellitus, hematologic disorders, and dysphagia. Minimal evidence demonstrates significant gaps in our clinical knowledge that compromises clinical decision‐making and management of these medically complex individuals. The creation of evidence‐based clinical guidance for this population will not be possible until these gaps are addressed. 相似文献