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81.
Some of the characteristic features of aging skin, such as wrinkling, loss of elasticity, and atrophy, can largely be attributed to dermal changes. The amount of collagen in the skin decreases, while the cross linking increases, and the solubility of collagen is reduced. The total number of fibroblasts decreases, and their metabolism shows characteristic alterations. Some of the functions of fibroblasts in aging skin, such as the synthesis of protein and collagen, but also proliferation and chemotaxis, can be investigated by means of in vitro models. In addition, various syndromes of premature aging (e.g. progeria, Werner's syndrome) have proved useful models and have contributed considerably to the understanding of aging processes. 相似文献
82.
Efficacy and tolerability of pantoprazole 40 mg versus 80 mg in patients with reflux oesophagitis. 总被引:4,自引:2,他引:2
van Rensburg CJ Honiball PJ Grundling HD van Zyl JH Spies SK Eloff FP Simjee AE Segal I Botha JF Cariem AK Marks IN Theron I Bethke TD 《Alimentary pharmacology & therapeutics》1996,10(3):397-401
BACKGROUND: Pantoprazole is a substituted benzimidazole which is a potent inhibitor of gastric acid secretion by its action upon H+, K+- ATPase. METHODS: Pantoprazole 40 mg and 80 mg were compared in a randomized double-blind study in 192 out-patients with stage II or III (Savary-Miller classification) reflux oesophagitis. Patients received either pantoprazole 40 mg (n = 97) or pantoprazole 80 mg (n = 95), once daily before breakfast for 4 weeks. Treatment was extended for a further 4 weeks if the oesophagitis had not healed. RESULTS: After 4 weeks complete healing of the reflux oesophagitis was seen in 78% of protocol-correct patients given pantoprazole 40 mg daily (n = 86), and in 72% in the 80 mg (n = 87) group. The cumulative healing rates after 8 weeks were 95 and 94%, respectively (P > 0.05, Cochran-Mantel- Haenszel), and time until healing of oesophagitis comparable in both groups. Differences between doses were also not significant in an intention-to-treat analysis. Both dosing schedules were well tolerated and the patients experienced remarkable symptom relief. No adverse event or changes in laboratory values of clinical significance could definitely be ascribed to the trial medication. CONCLUSION: The 40 mg pantoprazole dosage is comparable to 80 mg in reflux oesophagitis, both in efficacy and tolerability. 相似文献
83.
A method of automatic exposure termination (AET) for xeromammography has been devised, significantly reducing the rate of repeat exposures due to poor choice of manual exposure factors. AET images are of good quality and are reliably produced. The concept of AET is based on the existence of an optimal transmitted exposure to the selenium plate, which is easily determined experimentally. In routine clinical xeromammography, a repeat rate of 20% was eliminated by the use of AET. 相似文献
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Basal membranes are an ubiquitous component of all human organs and fulfil a large variety of functions. They separate epithelial from mesenchymal tissue and control the passage of substances, of inflammatory as well as tumor cells. They form the extracellular cytoskeleton, regulate growth processes, and play an important part in wound healing. Ultrastructurally, the lamina densa can be distinguished from the lamina lucida. Anchoring fibrils connect the basal membrane of the dermoepidermal junction with the underlying dermis, while anchoring plates connect it with the epidermal cells. During the last few years, various components of the basal membrane have been biochemically analyzed. Different proteins were characterized, and their corresponding morphological structure could be identified. The growing knowledge regarding the structure and composition of the dermo-epidermal junction has led to a better understanding of many diseases involving this structure, in particular inborn and acquired bullous diseases, but also that of the role of the basal membrane in metastasis and tumor invasions. The characterization of antigens in bullous diseases with circulating antibodies has led to exact diagnostic criteria concerning the often overlapping disorders and allows, e.g., the differentiation between bullous pemphigoid and epidermolysis bullosa acquisita. 相似文献
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The haemoglobinopathies are a group of autosomal recessively inherited diseases that are common among populations in the Mediterranean, in Africa and large parts of Asia. In Germany, the immigration of people from those parts of the world has resulted in an increased occurrence in particular of beta thalassaemia. Homozygous patients usually become transfusion dependent during the first year of life as the excess of alpha globin chains in the erythroid precursors causes a most severe dyserythropoietic anaemia. Genetic determinants that diminish the alpha globin chain excess are thus clinically significant. Here, we describe the molecular genetic changes that result in an increased gamma globin gene expression and hende in a binding of alpha globin chains as HbF. We discuss the significance of those changes for the clinical course of beta thalassaemia and for the elucidation of the ontogenetic processes of gene regulation during the perinatal haemoglobin switch. 相似文献
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Sonographic breast imaging has been useful in the differentiation of cystic from solid masses. It has also been helpful in the characterization of palpable breast masses in the absence of corresponding abnormalities. The authors undertook a prospective study that incorporated pulsed Doppler analysis into sonographic real-time imaging of solid breast masses. Thirty-eight patients were examined. In 12 of the patients there were positive Doppler signals, while in 26 patients there were no Doppler signals. The 12 patients showing positive Doppler signals proved to have infiltrating ductal carcinoma, while the 26 patients with negative Doppler signals proved to have benign breast disorders. Pulsed Doppler analysis as a supplement to sonographic real-time imaging shows promise for the identification of breast carcinoma. 相似文献