OVERHEATING IN BED AS AN IMPORTANT FACTOR IN MANY COMMON DERMATOSES

Background. Extensive questioning of patients with a wide variety of skin disorders led to the impression that nocturnal overheating was probably an important factor in the initiation and the perpetuation of many skin disorders. Methods. In order to test the hypothesis, 12 “clean-skinned” subjects (6M/6F) aged 18 to 45 years were monitored electronically every 30 seconds during an 8 hour sleep period (2300 to 0700 hours), sleeping under a standard 10 tog duvet. Results. All the subjects were too hot by 3 to 4°C. All showed changes in their EEG patterns with reduced REM sleep, increased awakenings, and all showed changes in their sleep stage patterns. In addition, they all showed evidence of increased sweating in the “heat-sink” area. Conclusions. The mechanisms where by such changes could be implicated in the precipitation and perpetuation of skin disease are discussed. “Lifestyle” modification as a very effective, noninvasive, therapeutic regime is recommended. Further research along these lines would probably be very valuable and instructive.     

Aortopulmonary window with patent ductus arteriosus and interrupted aortic arch: A case report

Indian Journal of Thoracic and Cardiovascular Surgery -     

Decreased density of beta-adrenergic and muscarinic cholinergic receptor sites in the vasa nervorum of aged rats

The pharmacological profile and the anatomical localization of beta-adrenergic and muscarinic cholinergic receptors of the vasa nervorum were studied in sections of sciatic nerve using radioreceptor binding and light microscope autoradiography techniques. Sprague—Dawley rats of 4 and 24 months of age were used. [³H]Dihydroalprenolol (DHA) and [³H]quinuclidinyl benzilate (QNB) were used to label beta-adrenergic and muscarinic cholinergic receptors, respectively. The ligands were bound to sections of rat sciatic nerve in a manner consistent with the labelling of beta-adrenergic or muscarinic cholinergic receptors in the 2 age groups investigated. The dissociation constant (K_d) values (about 1.37 nM for [³H]DHA and 0.75 nM for [³H]QNB) did not significantly change between 4- and 24-month-old rats. The maximum concentration of binding sites (B_max) for [³H]DHA was decreased by about 35% in 24 in comparison with 4-month-old rats. The B_max value autoradiogaphy revealed the development of specific silver grains in the medial layer of epineurial and perineurial arteries in sections of sciatic nerve exposed either to [³H]DHA or [³H]QNB. The number of silver grains developed in epineurial and perineurial arteries of rats of 24 months is significantly lower than in animals of 4 months. The above results suggest the occurrence of an age-dependent loss in the density of beta-adrenergic and muscarinic cholinergic receptors of vasa nervorum.     

Hypertensive brain damage: comparative evaluation of protective effect of treatment with dihydropyridine derivatives in spontaneously hypertensive rats

Hypertension is the main risk factor for cerebrovascular disease including vascular dementia and control of blood pressure might protect from lesions causing cognitive impairment. The influence of anti-hypertensive treatment on hypertensive brain damage was assessed in spontaneously hypertensive rats (SHR). SHR and age-matched normotensive Wistar Kyoto (WKY) rats were treated from the 14-26th week of age with the dihydropyridine-type Ca2+ channel blockers lercanidipine, manidipine and nimodipine and as a reference with the non-dihydropyridine-type vasodilator hydralazine. Volume of brain areas, number of nerve cells and glial fibrillary-acidic protein (GFAP)-immunoreactive astrocytes and neurofilament 200 kDa immunoreactivity were investigated in frontal and occipital cortex and in hippocampus. In control SHR, systolic blood pressure (SBP) was significantly higher in comparison with WKY rats. Compounds tested decreased to a similar extent SBP values in SHR, with the exception of nimodipine that caused a smaller reduction of SBP compared with other compounds. Decreased volume and number of nerve cells and loss of neurofilament protein immunoreactivity were observed in SHR. GFAP-immunoreactive astrocytes increased in number (hyperplasia) and in size (hypertrophy) in the frontal and occipital cortex of control SHR, and only in number in the hippocampus. Anti-hypertensive treatment countered in part microanatomical changes occurring in SHR. Drugs investigated with the exception of nimodipine exerted an equi-hypotensive effect. In spite of this the best protection was exerted by lercanidipine and, to a lesser extent, by nimodipine. Compared with nimodipine, lercanidipine induced a more effective decrease of SBP. This may represent an advantage in the treatment of hypertension with risk of brain damage.     

Localization of 5-hydroxytryptamine-like immunoreactive cells and nerve fibers in the rat female reproductive system.

The presence of 5-hydroxytryptamine (5-HT)-like immunoreactivity (IR) was studied in the rat female reproductive system using polyclonal antibodies directed against 5-HT. Moreover, 5-HT levels in the ovary, oviduct, uterus, and cervix were measured by high-pressure liquid chromatography with electrochemical detection. The highest 5-HT concentrations were found in the oviduct, followed in descending order by the cervix, the ovary, and the uterus. Most 5-HT-like IR was observed in the cytoplasm of mast cells. These cells were found in the connective tissue around the fimbria, in the oviduct, in the uterus, and in the ovary. Mast cells are clustered in the proximity of the parenchymal blood vessels. Moreover, a few 5-HT-like nerve fibers were found distributed mainly perivascularily in the uterine cervix and in the uterine horns as well as in the oviduct. IR nerve fibers were rarely seen within the ovary. The present data provide direct evidence that 5-HT in the female reproductive system not only is associated with mast cells but is located in nerve fibre-like structures as well. The functional significance of this probable 5-HT-ergic innervation of the female reproductive tract discovered in the present study should be clarified in future investigations.     

Glial fibrillary acidic protein immunoreactive astrocytes in developing rat hippocampus.

The developmental pattern of glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes was investigated in the hippocampus (subfields CA1, CA3 and CA4) and in the dentate gyrus of male and female rats aged 11, 16, 30, 90 and 150 days by immunohistochemistry associated with image analysis. Analysis was centred on stratum radiatum, a hippocampal area rich in GFAP-immunoreactive astrocytes. The volume of different portions of hippocampus, the number and the size of astrocytes, the intensity of cell body GFAP immunostaining as well as the extension of astrocyte were assessed. A maturation pattern consisting in higher cellular expression of GFAP, an increase in overall cell size and expanding arborisation from the 11th to the 30th postnatal day, followed by stabilisation of these parameters until the 90th day of life, and a subsequent decrease in the oldest age group studied was found. A sex-related different temporal pattern of astrocytes maturation in size and GFAP content was observed in the CA1 subfield only. The increase of GFAP content during pre-weaning ages was less pronounced in females than in males as well as the decrease between the 90th and the 150th day of age. Moreover, the size of astrocytes was larger in females than in males at the 11th and 150th days of life. These findings suggest that hippocampal astrocytes undergo rapid maturation in the 1st month of postnatal life, followed by a slow consolidation of this process until the 3rd month of life. At 5 months of age, there are still dynamic changes in the mature astrocytes, which become slender and thinner probably as a response to the increased volume of hippocampus noticeable at this age.     

Decreased inducibility of TNF expression in lipid-loaded macrophages

Background  

Inflammation and immune responses are considered to be very important in the pathogenesis of atherosclerosis. Lipid accumulation in macrophages of the arterial intima is a characteristic feature of atherosclerosis which can influence the inflammatory potential of macrophages. We studied the effects of lipid loading on the regulation of TNF expression in human monocyte-derived macrophages.