Submental space infection presenting in a patient with Fanconi's anaemia.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to C Ferretti.
Explore the source record for details and available documents.
BACKGROUND AND PURPOSE: Stroke, disability, and dementia often coexist in elderly people. We assessed the prevalence and mutual association of these disorders in an elderly rural population. METHODS: We carried out a door-to-door survey on all subjects aged 65 years or over (n=1032) living in a rural community. To evaluate the associations between stroke and disability and between stroke and dementia, we compared stroke patients with all stroke-free subjects by means of two multiple logistic regression analyses. Subsequently, we performed a case-control analysis by comparing each stroke patient with two age- and sex-matched population control subjects. RESULTS: We identified 80 stroke patients. After the exclusion of five incident cases, the prevalence of stroke was 7.3% (95% confidence interval [CI], 5.7 to 8.9). Sixty-five percent of stroke survivors and 23% of stroke-free subjects were disabled (age- and sex-adjusted odds ratio [OR], 6.3; 95% CI, 3.7 to 10.9). Thirty percent of stroke survivors and 5.7% of stroke-free subjects were demented. The OR for dementia (stroke patients versus all stroke-free subjects) was 5.8 (95% CI, 3.1 to 10.8) and became 3.4 (95% CI, 1.5 to 8.0) in the case-control analysis. CONCLUSIONS: In our population, the prevalence of stroke was higher than in previous studies. Stroke survivors were more disabled and more at risk for dementia than stroke-free subjects.
Astronauts have to face chronic stress during the mission period. This might cause: (i) increased adrenocortico-trophin (ACTH) and cortisol (Cort) secretion; (ii) impaired luteinizing hormone (LH) output with consequent testosterone (T) hyposecretion in men. Moreover, should the subjects prove not to synchronize their inner clocks to the time shift protocols defined by NASA, most results would be questionable. The aim of this study was to verify if plasma testicular androgens were lower than baseline and Cort biorhythm was preserved in male astronauts during a short duration flight.
4-Hydroxynonenal, an aldehyde produced from lipid peroxidation of cellular membranes, inhibits growth and induces differentiation of HL-60 human leukemic cell line. Since it is highly unstable in the culture medium, its effectiveness is increased when added repeatedly to the cell suspension. We have previously demonstrated that HNE inhibits c-myc but not N-ras expression in HL-60 cells. Here we investigate its effect on the expression of c-myb and c-fos, two early genes involved in the induction of myeloid and monocytic differentiation. Moreover, since c-fos is directly correlated with the intracellular level of cAMP, we also analysed the cAMP concentration after aldehyde treatment. HNE significantly inhibits c-myb expression during and after repeated treatments. A single administration of 1 microM HNE decreases c-myb mRNA at 1 hour whereas 10 microM HNE inhibits c-myb expression from 3 to 6 hours after treatment, and then the expression returns to the control level. By contrast, c-fos expression and intracellular cAMP concentration do not show any significant change after HNE treatments.
OBJECTIVES: To estimate the prevalence of dementia in an elderly rural population and to determine the effects of age, sex, and education. METHODS: To obtain prevalence estimates of both cognitive impairment and dementia a door to door two phase population survey was carried out in three rural villages in central Italy. Of 1147 inhabitants older than 64, 968 (84.4%) completed the protocol. RESULTS: The prevalence rates (cases per 100 population over 64) were 8.0 for dementia and 27.3 for cognitive impairment. The prevalence rate for dementia did not differ between men and women (7.9 v 8.2), but increased with age (from 1.1 at age 65-69 to 34.8 at age 90-96). Subjects with less than three years of schooling had a significantly higher prevalence of dementia (14.6; 95% confidence interval (95% CI) 10.2-19.1) than subjects with three or more years of schooling (5.9; 95% CI 4.2-7.7). At the multivariate logistic analysis, the risk related with a low level of education was still present after adjustment for age and sex (OR = 2.0; 95% CI 1.2-3.3). Alzheimer's disease was diagnosed in 64% of the 78 demented patients, vascular dementia in 27%, and other dementing diseases in 9%. CONCLUSIONS: In both Alzheimer and vascular dementia subtypes, the prevalence rates did not differ between men and women, but increased with age and were higher in subjects with a low level of education.
This paper concerns the formal study on the generative powers of extended splicing (H) systems. First, using a classical result by Post which characterizes the recursively enumerable languages in terms of his Post Normal systems, we establish several new characterizations of extended H systems which not only allow us to have very simple alternative proof methods for the previous results mentioned above, but also give a new insight into the relationships between families of extended H systems. We show a kind of normal form for extended H systems exactly characterizing the class of regular languages. We also show a new representation result for the family of context-free languages in terms of extended H systems.
The role of the histamine (HA) H3 receptor (estimated by binding of [3H]N-alpha-methyl HA in the brain cortex) in the response of male rats to four types of stress was evaluated: acute weak foot-shock stress (0.5 mA x 1 s x 5 times), acute intense foot-shock stress (1mA x 10 s x 5 times), acute restraint stress (60 min at 24 degrees C) and chronic variate stress. Two groups of rats received chronic treatment with a tricyclic antidepressant: amitriptyline (5 mg/kg i.p.); one group was also chronically stressed. HA-H3 receptor density rapidly decreased in acute intense foot-shock and chronic variate stress, but was unchanged in acute weak foot-shock and restraint stress. Amitripytline counteracted the chronic variate stress-induced decrease, and increased HA-H3 receptor density when chronically administered in the non-stressed control group. These results indicate that cortical HA-H3 receptor density is affected by the response to stress in function of the type, duration and intensity of the stressor.
This paper examines the biochemical and behaviour changes induced by an acute stress (five 10-s, 1-mA foot-shocks) in three groups of rats: (1) never stressed, (2) subjected to chronic variate stress for 20 days, (3) subjected to the same chronic stress and treated with 5 mg/kg per day amitriptyline. After 15 min, acute stress led to a marked reduction in cortical beta-adrenoceptor and 5-HT2 receptor density, whereas the density of the 5-HT1A receptors was unchanged. Chronic stress also increased beta-adrenoceptor and 5-HT2 receptor density and had no effect on 5-HT1A. Acute stress diminished the density of beta-adrenoceptors in chronically stressed animals, but did not alter that of the two 5-HT populations. Amitriptyline alone reduced beta-adrenoceptor and 5-HT2 receptor densities only. Acute stress applied to animals treated with amitriptyline reduced 5-HT1A receptors, and caused a further beta-adrenoceptor decrease, but had no further effect on the 5-HT2 receptors. On behaviour, chronic stress diminished reactivity to the acute stress. This reduction was fully abolished by amitriptyline. An open-field study showed that acute stress reduced motor activity, increased latency times and diminished rearing in the controls, whereas chronic stress reduced motor activity only. No significant changes in behaviour were induced by the acute stress in animals subjected to chronic stress. The combination of chronic stress with amitriptyline was accompanied by a diminution of exploratory activity that persisted after the acute stress.(ABSTRACT TRUNCATED AT 250 WORDS)
Explore the source record for details and available documents.
The involvement of the histaminergic system in the regulation of weak stress was studied in rats. The parameters examined were the brain receptors and corticosterone (CS) plasma levels. The benzodiazepine diazepam [(2 mg/kg intraperitoneally (IP)] influenced neither foot-shock-induced changes in CS levels nor [3H]-histamine [(3H)-HA] binding site constants, whereas the tricyclic antidepressive amitriptyline (10 mg/kg IP) partially counteracted a plasma CS increase and prevented changes in [3H]-HA binding in the stressed rat brain. These observations are in agreement with the known activities of amitriptyline on monoaminergic metabolism and receptors. Moreover, these data provide further experimental evidence of the functional role of the central histaminergic system in organized stress response.
1. The mechanism of action and biological activity of a series of R-substituted and di-R-substituted phenylfuroxans is reported. 2. Maximal potency as vasodilators on rabbit aortic rings, precontracted with noradrenaline (1 microM), was shown by phenyl-cyano isomers and by the 3,4-dicyanofuroxan, characterized by a potency ratio 3-10 fold higher than glyceryl trinitrate (GTN). This effect was reduced upon coincubation with methylene blue or oxyhaemoglobin (10 microM). 3. The furoxan derivatives showing maximal potency as vasodilators were also able to inhibit collagen-induced platelet aggregation, with IC50 values in the sub-micromolar range. 4. The furoxan derivatives were able to stimulate partially purified, rat lung soluble guanylate cyclase; among the most active compounds, the 3-R-substituted isomers displayed a higher level of stimulatory effect than the 4-R analogues. 5. Solutions (0.1 mM) of all the tested furoxans, prepared using 50 mM phosphate buffer, pH 7.4, (diluting 10 mM DMSO stock solutions) did not release nitric oxide (NO) spontaneously; however in presence of 5 mM L-cysteine, a significant NO-releasing capacity was observed, which correlated significantly with their stimulation of the guanylate cyclase activity.
Explore the source record for details and available documents.
The peroxidative breakdown of membrane polyunsaturated fatty acids leads to the production of various carbonylic compounds: among these, 4-hydroxynonenal (HNE) displays many biological properties related to neutrophil functions. It stimulates rat and human polymorphonuclear (PMN) cell migration and has been detected during inflammation. The aim of this study was to elucidate and well characterize the mechanism of action of HNE. We observed that micromolar HNE concentrations that influence migration do not stimulate differently from many other chemoattractants the human PMN chemiluminescence (CL) induced by opsonized zymosan or phorbol 12-myristate 13-acetate (PMA). Higher HNE concentrations inhibit the light emission of stimulated PMN. Addition of 0.5 mM L-arginine (L-arg), the substrate of nitric oxide synthase, into the incubation medium had the effect of modifying human CL. In fact, HNE at 10-6 M, a concentration which is ineffective in absence of L-Arg, at 10-5 M reduces CL emission of PMA-stimulated human PMN. These observations have been confirmed by electron-spin resonance (ESR) analysis. HNE, according to other stimuli, induced PMN phosphoinositide-specific phospholipase C (PL-C). All these results considered together suggest the conclusion that HNE represents an interesting endogenous molecule that plays a role as an inflammatory mediator involved a) in the recruitment of phagocytic cells at the inflamed area, and b) in the modulation of respiratory burst and of nitric oxide (NO) production.
4-Phenyl-3-furoxancarbonitrile (2) affords nitric oxide under the action of thiol cofactors. Two principal products were isolated in the reaction with thiophenol: the phenylcyanoglyoxime (6) and 5-amino-3-phenyl-4-(phenylthio)isoxazole (7). Mechanisms which could account for the formation of these two products are discussed. Compound 2 is an efficient activator of the rat lung soluble guanylate cyclase, displays high vasodilatory activity on strips of rat thoracic aorta precontracted with noradrenaline, and is a potent inhibitor of platelet aggregation.
4-Hydroxynonenal (HNE) is produced during peroxidation of polyunsaturated fatty acids. It exerts a chemokinetic effect on human polymorphonuclear leukocytes (PMN). Investigations of this mechanism were performed. The results indicate that [3H]-HNE binding to PMN results both in non-specific bonds to the numerous SH groups of the cells and in binding to a saturable, reversible and specific HNE site. Scatchard analysis revealed that this is a single site with an apparent affinity constant of 319 nM and a density of 1.57 pmol (10(6))-1 cells. This specific binding site may be involved in the chemokinetic effect of HNE.
Since estradiol (E2) either increases or reduces the number of dopamine receptors in the corpus striatum of adult rats, depending on the dose and length of administration, the sensitivity of the two receptor subpopulations (D1 and D2) to E2 during ontogenesis was investigated. Rats of both sexes received either 10 micrograms/kg E2 for 3 days or 50 micrograms/kg for 6 days, and were sacrificed at the age of 15, 21, 40 and 120 days. D1 receptors (identified by [3H]SCH 23390 binding) displayed no changes in density and affinity in function of age, sex or E2 dose, whereas the D2 receptors (identified by [3H]spiperone binding) fell after the lower dose in all groups, and the higher dose resulted in supersensitivity in males of all ages, but only in the 15-day-old females. These findings show that the effect of E2 is bivalent on D2 density only. The effect of its brief administration at a low dose is not sex-dependent, whereas at higher doses administered for longer periods it appears to involve mechanisms linked to sexual differentiation after birth.
A weak electric foot-shock stressful stimulus (0.5 mA x 1 s x 5 times) significantly increases plasma corticosterone (CS) levels and modifies [3H]-histamine ([3H]-HA) binding site constants related to H2 receptors in rat cortical membranes. Progressive and total recovery of basal binding characteristics occurs 90 min later. A double-foot-shock stress procedure delays [3H]-HA binding characteristic recovery instead of strengthening stress effects. This finding is further evidence of involvement of the brain's histamine receptors in the response to mild stress.
It is assumed that theophylline (THEO) and its xanthinic derivatives inhibit lung phosphodiesterase (PDE) and block adenosine receptors in the induction of bronchodilatation. Since the theophyllinic compound ambroxol-theophylline-7-acetic acid (ATA) has been shown in vivo to be a sound bronchodilator, this paper compares the action of ambroxol-theophylline-7-acetate (ATA), its two components, theophylline-7-acetic acid (TAA) and ambroxol (AMB), and theophylline (THEO) on the hydrolytic activity of three rat-lung cAMP PDE (types I, III and IV) and on striatal adenosine receptors. THEO inhibited all three isoenzymes with equal intensity, whereas ATA was as powerful but inhibited types III and IV only, on which AMB and TAA also showed lower effects. Lastly, unlike THEO, ATA and its two components were unable to antagonize adenosine receptors. Taken as a whole, these results suggest that the bronchodilating activity of ATA is the result of specific inhibition of particular forms of PDE and is thus more specific than that of THEO alone.