The conformation of the heptacosapeptide hormone, gastrin releasing peptide, has been studied in buffer and in the presence of lipids, using static and dynamic fluorescence and CD. The results ...obtained show that, in buffer, the hormone exists in a collection of flexible, random coil type conformers, characterized by a beta-turn between residues 14-19. On the other hand, organic solvents can induce some degree of ordered secondary structure in the peptide chain. The marked changes, observed in CD and fluorescence spectra upon addition of lysolecitin micelles and dimyristoylphosphatidylserine vesicles, clearly show that the peptide interacts with lipids, assuming a lipid specific configuration. Interestingly, no significative spectroscopic changes are produced by exposure to dimyristoylphosphatidylcholine vesicles both in the gel and liquid-chrystalline phases, suggesting a requirement for negatively charged lipids during the process of hormone-membrane interaction.
The brain in congestive heart failure Acanfora, D.; Trojano, L.; Iannuzzi, G.L. ...
Archives of gerontology and geriatrics,
11/1996, Letnik:
23, Številka:
3
Journal Article
Recenzirano
In the present paper we discuss two issues about relationships between congestive heart failure and the brain. First, major acute cerebrovascular events are very frequent among elderly people, but ...stroke does not appear to be frequently associated with congestive heart failure. Second, some cardiovascular conditions may determine progressive damage of cerebral tissue, with consequent impairment of cognitive functions. The association of cognitive impairment and cardiovascular diseases may dramatically increase morbility and mortality risks in the elderly. Recent studies seem to show that hypotension and congestive heart failure are risk factors for dementia in elderly people. In view of this data, an Italian multicentric study on congestive heart failure in hospitalized elderly patients (CHF Italian Study I) included a brief screening of cognitive abilities (MMSE). The presence of congestive heart failure induced a significant decrease of MMSE scores: mean MMSE score after statistical adjustment for the other variables was about one point lower in patients with congestive heart failure respect to elderly patients affected by heart disease but without congestive heart failure. A novel multicentric study (CHF Italian Study II) has been performed to identify cognitive functions more specifically impaired during congestive heart failure in the elderly. Preliminary data relative to 385 patients, confirmed that congestive heart failure may induce a generalized impairment of cognitive functions. These data have relevant clinical implications because they demonstrate that a multidisciplinary approach is necessary in these patients, both for prevention and rehabilitation therapy.
Neuronal morphology and dendritic architecture of the tuberal and mammillary regions in the hypothalamus of the quail (Coturnix coturnix japonica) were investigated by means of classical ...neuroanatomical methods (Bodian silver impregnation, Luxol-fast blue, cresyl violet, toluidine blue, rapid Golgi method). The tuberal region is characterized by isodendritic neurons, in particular: a) pyriform and bipolar neurons, occasionally arranged diagonally to the ventricular surface; b) CSF-contacting neurons, located subependymally or more deeply in the periventricular gray, which are especially abundant in the paraventricular organ and in the proximity of the median eminence; c) numerous multipolar neurons, endowed with stout, almost unbranched dendritic processes, occupying generally the medio-lateral areas of the hypothalamus. Some multipolar neurons display somata, pyramidal or ovoidal in shape, almost imperceptibly tapering into three or more dendritic trunks. These relatively straight and long dendrites are rich in dendritic spines. In the mammillary region, Golgi impregnation shows multipolar neurons of medium size, most likely belonging to the lateral mammillary nucleus.
This study looked at factors contributing to a favor- able adjustment and sense of well being among a non-clinical popu- lation of divorcing parents. Subjects responded to a survey of demo- graphic ...and divorce data and self perceptions about stress coping abilities. The results suggest that higher levels of coping resources are connected with greater optimism about the future, fewer finan- cial problems, more confidence in parenting ability, and a more satisfactory relationship with the former spouse. Coping resources may also be affected by a person's race or a combination of race and gender.
The conformation of the tetradecapeptide hormone bombesin has been studied in buffer and in the presence of lysolecithin micelles, using static and dynamic fluorescence, CD, and one- and ...two-dimensional nmr. The results obtained show that in buffer bombesin is present in an extended flexible chain, with no evidence for any ordered secondary structure. A marked change in the CD spectrum is observed changing from buffer to the lipid suspension. Concomitantly, the 1H-nmr spectrum of bombesin, in a D2O lipid dispersion, shows the persistence of resonances due to exchangeable protons and in similar conditions the fluorescence intensity increases. We think therefore that these results strongly support the hypothesis that bombesin interacts with the lipid phase, assuming ordered secondary structure. Finally, the marked dependence of tryptophan fluorescence quantum efficiency and order parameter from the hormone concentration in the presence of lysolecithin but not in buffer leads to the conclusion that bombesin can associate into the lipid matrix.
Sub-clinical hypothyroidism is defined by elevated serum thyroid-stimulating hormone level in the face of normal free thyroid hormone values. The role of sub-clinical hypothyroidism as independent ...risk factor for atherosclerosis has been suggested by clinical studies which demonstrated a higher prevalence of peripheral arterial disease, aortic atherosclerosis and coronary artery disease, in patients affected by this pathological condition. This association have been confirmed by the assessment of subclinical atherosclerosis by means of B-mode ultrasonography. Using this method an higher intima-media thickness (IMT) of carotid artery, a close marker of early atherosclerosis changes, have been found in patients with subclinical hypothyroidism compared to control euthyroid subjects. Levothyroxine replacement therapy of sub-clinical hypothyroidism was able to improve both the carotid IMT and atherogenic lipid profile, suggesting that lipid infiltration of the endothelium may represent a mechanism underlying the atherosclerotic process in patients with this pathological condition. Morphologic and functional changes of the myocardial tissue has been also demonstrated in patients with sub-clinical hypothyroidism, using ultrasonic backscatter video densitometry. All these data provide evidence of cardiovascular remodelling in patients with sub-clinical hypothyroidism. Vascular remodelling in sub-clinical hypothyroidism patients could be also studied by means of backscatter analysis of carotid artery, a method which allows the assessment of vascular sclerosis. Our preliminary results using this method suggested that not only atherosclerosis by also sclerosis characterises vascular remodelling in sub-clinical hypothyroidism patients.
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