„Elaioplasten“ fehlen den Schließzellen vonHosta plantaginea

Zusammenfassung Die Korollen-Epidermis vonHosta plantaginea besitzt in jungen Blüten in jeder Zelle je einen wohlentwickelten Elaioplasten, den Stomata-Schließ-zellen fehlen diese Inhaltskörper.     

Stomata-Anomalie vonOpuntia-Virusträgern

Zusammenfassung Die Spaltöffnungsapparate von Kakteen (Opuntia. Epiphyllum, Rhipsalis), die in den Epidermiszellen Eiweißspindeln enthalten, degenerieren häufig oder weisen eine abnorme Entwicklung auf. So kommen bei den Blättern vonOpuntia subulata zahlreiche Zwillingsspaltöffnungen vor, die aus einer Mutterzelle hervorgehen (eineiige Zwillinge). Die Eiweißspindeln werden als Virus-Körper aufgefaßt und es wird vermutet, daß die gehäufte Bildung der abnormen Stomata mit der Virusinfektion zusammenhängt, obwohl die Schließzellen der Kakteen keine Virus-Einschlußkörper enthalten. Die Abnormitäten und Verkümmerungen des Spaltöffnungsapparates wären demnach ein mikroskopisch sichtbares Symptom an äußerlich symptomlosen Virusträgern.     

Explanatory models of black lung: Understanding the health-related behavior of Appalachian coal miners

Many retired coal miners who are eligible for care in a black lung treatment enter at little or no cost to themselves do not enter into available programs or discontinue soon after beginning therapy. Reasons for this behavior are related to the prevalent beliefs among Appalachians concerning the course of black lung and the appropriate treatment for it. The miners' health beliefs are clearly at odds with those of the health care providers who work in the centers. Using the concept of explanatory model, popular and professional health cultures are analyzed, focusing on course of disease, sick role, appropriate treatment, and expected outcome. Differences in explanatory models are discussed with regard to implications for the organization and delivery of care to retired coal miners with black lung.     

Endocrine markers of semistarvation in healthy lean men in a multistressor environment.

We tested the hypothesis that key endocrine responses to semistarvation would be attenuated by changing only the food intake in a multistressor environment that also included sustained workload, inadequate sleep, and thermal strain. Serum hormones were compared within and between two groups of healthy young male volunteers participating in the 8-wk US Army Ranger course, with four repeated cycles of restricted energy intakes and refeeding: group 1 (n = 49) and group 2 (n = 48); energy deficits averaged 1,200 and 1,000 kcal/day, respectively. After 8 wk, most of group 1 achieved a minimum body fat, serum 3,5,3'-triiodothyronine (T(3)) was below normal (78 +/- 20 ng/dl), testosterone (T) approached castrate levels (4.5 +/- 3.9 nmol/l), insulin-like growth factor I (IGF-I) declined by one-half (75 +/- 25 microg/l), and cholesterol rose from 158 +/- 31 to 217 +/- 39 mg/dl. Bioavailable T(3) and T were further reduced by increases in their specific binding proteins in response to declining insulin. Refeeding, even with continuation of the other stressors, produced prompt recovery of T(3), T, and IGF-I. Higher energy intakes in group 2 attenuated the subclinical hypothyroidism and hypercholesterolemia, whereas consistent luteinizing hormone suppression indicated centrally mediated threshold effects on gonadal hormone suppression. We conclude that low T, T(3), and IGF-I remained reliable markers of acute energy deficits in the presence of other stressors; elevated cholesterol and cortisol provided information about chronic status, corresponding to diminishing body fat stores.     

Hitze-Resistenz funktionierender Stomata-Nebenzellen

Ohne Zusammenfassung     

Elaioplasten fehlen den Schließzellen vonBotrychium

Ohne Zusammenfassung