RESUMO
Tau protein is of primary importance for neuronal homeostasis and when hyperphosphorylated (PP-Tau), it tends to aggregate in neurofibrillary tangles, as is the case with tauopathies, a class of neurodegenerative disorders. Reversible PP-Tau accumulation occurs in the brain of hibernating rodents and it was recently observed in rats (a non-hibernator) during synthetic torpor (ST), a pharmacological-induced torpor-like condition. To date, the expression of PP-Tau in the rat enteric nervous system (ENS) is still unknown. The present study immunohistochemically investigates the PP-Tau expression in the myenteric plexus of the ileum and colon of normothermic rats (CTRL) and during ST, focusing on the two major subclasses of enteric neurons, i.e., cholinergic and nitrergic.Results showed that both groups of rats expressed PP-Tau, with a significantly increased percentage of PP-Tau immunoreactive (IR) neurons in ST vs. CTRL. In all rats, the majority of PP-Tau-IR neurons were cholinergic. In ST rats, the percentage of PP-Tau-IR neurons expressing a nitrergic phenotype increased, although with no significant differences between groups. In addition, the ileum of ST rats showed a significant decrease in the percentage of nitrergic neurons. In conclusion, our findings suggest an adaptive response of ENS to very low core body temperatures, with changes involving PP-tau expression in enteric neurons, especially the ileal nitrergic subpopulation. In addition, the high presence of PP-Tau in cholinergic neurons, specifically, is very interesting and deserves further investigation. Altogether, these data strengthen the hypothesis of a common cellular mechanism triggered by ST, natural hibernation and tauopathies occurring in ENS neurons.
Assuntos
Colo/fisiopatologia , Íleo/fisiopatologia , Plexo Mientérico/metabolismo , Torpor/fisiologia , Proteínas tau/metabolismo , Animais , Masculino , Fosforilação , Ratos , Ratos Sprague-DawleyRESUMO
PURPOSE: To provide information about main pregnancy outcomes in HIV-HCV coinfected women and about the possible interactions between HIV and HCV in this particular population. METHODS: Data from a multicenter observational study of pregnant women with HIV, conducted in Italian University and Hospital Clinics between 2001 and 2015, were used. Eligibility criteria for analysis were HCV coinfection and at least one detectable plasma HCV-RNA viral load measured during pregnancy. Qualitative variables were compared using the Chi-square or the Fisher test and quantitative variables using the Mann-Whitney U test. The Spearman's coefficient was used to evaluate correlations between quantitative variables. RESULTS: Among 105 women with positive HCV-RNA, median HCV viral load was substantially identical at the three trimesters (5.68, 5.45, and 5.86 log IU/ml, respectively), and 85.7 % of the women had at least one HCV-RNA value >5 log IU/ml. Rate of preterm delivery was 28.6 % with HCV-RNA <5 log IU/ml and 43.2 % with HCV-RNA >5log (p = 0.309). Compared to women with term delivery, women with preterm delivery had higher median HCV-RNA levels (third trimester: 6.00 vs. 5.62 log IU/ml, p = 0.037). Third trimester HIV-RNA levels were below 50 copies/ml in 47.7 % of the cases. No cases of vertical HIV transmission occurred. Rate of HCV transmission was 9.0 % and occurred only with HCV-RNA levels >5 log IU/ml. CONCLUSIONS: Coinfection with HIV and HCV has relevant consequences in pregnancy: HIV coinfection is associated with high HCV-RNA levels that might favour HCV transmission, and HCV infection might further increase the risk of preterm delivery in women with HIV. HCV/HIV coinfected women should be considered a population at high risk of adverse outcomes.
Assuntos
Coinfecção/epidemiologia , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Hepatite C/complicações , Hepatite C/epidemiologia , Complicações Infecciosas na Gravidez/epidemiologia , Adulto , Feminino , Hepacivirus/isolamento & purificação , Hospitais Universitários , Humanos , Recém-Nascido , Itália/epidemiologia , Masculino , Gravidez , Resultado da Gravidez , Nascimento Prematuro , RNA Viral/sangue , Carga ViralRESUMO
The study included 309 HIV-infected pregnant women receiving a lamivudine-containing antiretroviral regimen from week 25 of gestational age until 6 months postpartum, during breastfeeding. Twenty-seven of them (8.7%) were hepatitis B virus surface antigen (HBsAg) positive; at baseline, hepatitis B virus (HBV) DNA levels >3 log(10) IU/mL (with a median level of 6.2 log(10) IU/mL) were found in 10 women, who at one, three and six months postpartum had median levels of 5.2 log(10) IU/mL, 4.5 log(10) IU/mL and 2.8 log(10) IU/mL, respectively. Twenty-four of the 30 breast milk samples evaluated had undetectable HBV DNA and the other six had values between 15 and 155 IU/mL. Median lamivudine concentrations were 1070 ng/mL in serum and 684 ng/mL in breast milk. Among the 24 HBV-exposed children with available samples, 16 always tested negative, four had a transient infection, one had an undetermined status and three (12.5%) first tested positive at Month 12 or Month 24. Among the children born to the HBV-uninfected mothers of the same cohort, the rate of HBsAg positivity at 12-24 months was 2% (4/196). Our finding of the absence of significative levels of HBV DNA in the breast milk of co-infected mothers supports the present recommendations for breastfeeding in HBV-infected women. Horizontal transmission can be hypothesized for the infections detected in children at 12-24 months. Children born to HBV-positive mothers remained at higher risk of postnatal HBV acquisition compared to those born to HBV-negative women.
Assuntos
Fármacos Anti-HIV/uso terapêutico , Aleitamento Materno , Coinfecção , Infecções por HIV/tratamento farmacológico , Vírus da Hepatite B , Hepatite B/transmissão , Transmissão Vertical de Doenças Infecciosas , Lamivudina/uso terapêutico , Adulto , Terapia Antirretroviral de Alta Atividade , Aleitamento Materno/efeitos adversos , Criança , Feminino , Infecções por HIV/virologia , Hepatite B/virologia , Humanos , Masculino , Gravidez , Fatores de Risco , Adulto JovemRESUMO
Body homeostasis and sleep homeostasis may both rely on the complex integrative activity carried out by the hypothalamus. Thus, the three main wake-sleep (WS) states (i.e. wakefulness, NREM sleep, and REM sleep) may be better understood if the different cardio-respiratory and metabolic parameters, which are under the integrated control of the autonomic and the endocrine systems, are studied during sleep monitoring. According to this view, many physiological events can be considered as an expression of the activity that physiological regulations should perform in order to cope with the need to fulfill body and sleep homeostasis. This review is aimed at making an assessment of data showing the existence of a physiological interplay between body homeostasis and sleep homeostasis, starting from the spontaneous changes observed in the somatic and autonomic activity during sleep, through evidence showing the deep changes occurring in the central integration of bodily functions during the different WS states, to the changes in the WS states observed when body homeostasis is challenged by the external environment and when the return to normal ambient conditions allows sleep homeo- stasis to run without apparent physiological restrictions. The data summarized in this review suggest that an approach to the dichotomy between NREM and REM sleep based on physiological regulations may offer a framework within which observations that a traditional behavioral approach may overlook can be interpreted. The study of the interplay between body and sleep homeostasis appears, therefore, to be a way to understand the function of complex organisms beyond that of the specific regulations.
Assuntos
Sistema Nervoso Autônomo/fisiologia , Sistema Endócrino/fisiologia , Homeostase , Sono/fisiologia , Animais , HumanosRESUMO
OBJECTIVES: The aim of the study was to determine the modifications of the mutational archive in proviral HIV-1 DNA occurring during 24 months of intermittent or continuous highly active antiretroviral therapy (HAART). METHODS: The study population included subjects enrolled in the Istituto Superiore di Sanità Pulsed Antiretroviral Therapy (ISS PART) clinical trial. All of these patients were on first-line HAART and had plasma HIV-1 RNA below 50 HIV-1 RNA copies/mL. A genotypic resistance test was performed on HIV-1 DNA extracted from peripheral blood mononuclear cells (PBMC) at baseline and after 24 months of follow-up. Resistance-associated mutations (RAMs) were defined according to the International AIDS Society (IAS) USA classification. RESULTS: Sixty-nine subjects were included in the study [36 enrolled in arm A of the ISS PART (continuous HAART) and 33 enrolled in arm B (intermittent HAART)]. No major modifications of the mutational archive were found in either group after 24 months of follow-up, in terms of both the proportion of subjects with mutations and the total number of mutations. CONCLUSIONS: In this patient population, the mutational archive in HIV-1 DNA extracted from PBMC was stable for 24 months, irrespective of HAART modality, whether continuous or intermittent.
Assuntos
Antirretrovirais/administração & dosagem , Terapia Antirretroviral de Alta Atividade/métodos , DNA Viral/genética , Infecções por HIV/virologia , HIV-1/genética , Provírus/genética , Adulto , Idoso , Análise Mutacional de DNA , DNA Viral/efeitos dos fármacos , Farmacorresistência Viral/genética , Feminino , Infecções por HIV/tratamento farmacológico , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Mutação , RNA Viral/análise , Fatores de Tempo , Adulto JovemRESUMO
ISS-IP1, a multicenter, randomized, 48-week open trial, was designed to compare the introduction of ritonavir or indinavir in patients with previous nucleoside experience and CD4+ cell counts below 50/mm3. Concomitant antiretroviral treatment with nucleoside analogs was allowed. Primary efficacy measures were survival and time to a new AIDS-defining event or death, analyzed through the whole period of observation by the intention-to-treat approach. Primary toxicity measures were time to treatment discontinuation and adverse events, grade at least 3/serious, analyzed by an on-treatment approach. Evaluation-of efficacy also included CD4+ cell and RNA response. The trial enrolled 1251 patients in 5 months. At baseline, mean CD4+ cell count was about 20 cells/mm3 and mean HIV RNA copy number was 4.9 log10/ml in both groups. Overall, 402 patients in the ritonavir group and 250 patients in the indinavir group permanently discontinued the assigned treatment (relative risk, 1.96; 95% CI, 1.68-2.30; p = 0.0001), with most of this difference dependent on a higher number of discontinuation for adverse events in the ritonavir group. After a mean follow-up of 307 days (ritonavir, 304; indinavir, 309), 124 deaths (ritonavir, 61; indinavir, 63; relative risk, 0.96; 95% CI, 0.67-1.36; p = 0.80) and 330 new AIDS-defining events (ritonavir, 170; indinavir, 160; relative risk, 1.05; 95% CI, 0.85-1.31; p = 0.60) were observed. CD4+ cell counts increased in both groups in patients still receiving treatment, with about 100 cells gained by week 24 and 150 cells gained by week 48. Body weight also increased over time in both groups. Analysis of RNA response showed a decrease of 1.5 log10 or higher in both treatment groups. Overall, 400 patients in the ritonavir group and 338 patients in the indinavir group developed at least one grade 3/serious new adverse event during follow-up (relative risk, 1.48; 95% CI, 1.28-1.72; p = 0.0001). Favorable CD4+ cell and RNA responses at 24 and 48 weeks were observed in both groups of patients remaining on treatment. Indinavir showed slightly better effects in sustaining RNA, CD4+ cell, and body weight responses. Ritonavir and indinavir results were comparable in terms of clinical outcome (survival and AIDS-defining events).
Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , HIV-1/fisiologia , Indinavir/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico , Ritonavir/uso terapêutico , Adulto , Idoso , Contagem de Linfócito CD4 , Quimioterapia Combinada , Feminino , Infecções por HIV/imunologia , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , Resultado do TratamentoRESUMO
The role of catecholaminergic mechanisms in determining the changes in the rat's preoptic cyclic adenosine monophosphate (cAMP) concentration during sleep deprivation and recovery induced by ambient temperature was investigated in the present study. To this end, the activity of tyrosine hydroxylase, the rate-limiting enzyme in catecholamine biosynthesis, was measured in the preoptic region of rats maintained in: (a) control (22 degrees C for 52 h), (b) deprivation (-10 degrees C for 52 h), and (c) recovery (22 degrees C for 4 h after 48 h at -10 degrees C) conditions. The enzyme followed a Michaelis-Menten kinetic. The analysis of substrate-related kinetic parameters (Km and Vmax) did not show any clear-cut difference between experimental conditions, which, as already known, induce both sleep deprivation and recovery in relation to significant cAMP changes.
Assuntos
AMP Cíclico/metabolismo , Área Pré-Óptica/metabolismo , Privação do Sono/fisiologia , Tirosina 3-Mono-Oxigenase/metabolismo , Animais , Cinética , Masculino , Ratos , Ratos Endogâmicos , TemperaturaRESUMO
The occurrence of REM sleep episodes, separated by intervals >3 min (single episodes) and < or =3 min (sequential episodes), was determined in the rat during the recovery (ambient temperature (Ta) 23 degrees C, L period of the LD [12 h:12 h]-cycle), which followed the exposure to low Ta (0 and -10 degrees C) during the D period of the previous LD-cycle, either in normal light (DL) or in continuous darkness (DD). Both exposures were characterized by an almost complete disappearance of REM sleep, whilst the recoveries showed an increase in the amount of REM sleep in the form of sequential episodes, which in DD was particularly prominent and concomitant with a decrease in the amount of REM sleep in the form of single episodes. The initial 2 h-rate of REM sleep occurrence was lower following the exposure to Ta -10 degrees C, than to Ta 0 degrees C. In DD, such an effect was due to the large reduction in the occurrence of sequential REM sleep episodes. A functional correlate of this finding is that the accumulation capacity of a second messenger (cAMP) was found to be lower at the end of the exposure to Ta -10 degrees C, with respect to both the control (Ta 23 degrees C) and the end of exposure to Ta 0 degrees C, in the preoptic-anterior hypothalamus, but not in the cerebral cortex.
Assuntos
Temperatura Baixa/efeitos adversos , Escuridão/efeitos adversos , Área Pré-Óptica/fisiologia , Sono REM/fisiologia , Análise de Variância , Animais , Regulação da Temperatura Corporal/fisiologia , AMP Cíclico/metabolismo , Hipóxia/metabolismo , Masculino , Área Pré-Óptica/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
From a physiological viewpoint, REM sleep (REMS) is a period during which homeostatic physiological regulations are impaired. In the rat, REMS occurs in two forms respectively characterized by episodes separated by long intervals (single REMS episodes) and by episodes which have short intervals and occur in sequences (REMS clusters). Since the partition of REMS in the form of either single or clustered episodes may reveal how the REMS drive and body homeostatic processes interact in the control of REMS occurrence, we have used this approach to clarify the effects of the rhythmical delivery of an auditory stimulus (1000 Hz, 63 or 88 dB, 50 ms, every 20 s), which has been previously observed by different authors to enhance REMS in the absence of a previous sleep deprivation. Stimuli were delivered to pairs of animals and triggered by the occurrence of REMS in one rat (REMS-selective stimulation), whilst the other animal received the same stimulus irrespectively of the stage of the wake-sleep cycle (REMS-unselective stimulation). The results showed that the REMS-selective stimulation did not change the overall amount of REMS, since an increase in the occurrence of REMS clusters was concomitant with a decrease in the occurrence of single REMS episodes. In contrast, under the REMS-unselective stimulation, the total amount of REMS was increased during the second day of stimulation through an increase in the duration of both types of REMS episodes. Since during the REMS-unselective stimulation 87% of the stimuli fell outside REMS (i.e., during the REMS interval), the results show that the occurrence of REMS is more consistently affected when the stimuli are delivered in a period during which homeostatic physiological regulations are fully operant.
Assuntos
Estimulação Acústica , Sono REM/fisiologia , Percepção do Tempo/fisiologia , Animais , Córtex Cerebral/fisiologia , Eletroencefalografia , Análise de Fourier , Homeostase/fisiologia , Percepção Sonora/fisiologia , Masculino , Ratos , Ratos Sprague-Dawley , Processamento de Sinais Assistido por ComputadorRESUMO
The concentration of adenosine 3',5'-cyclic monophosphate was measured, during the wake-sleep cycle, in the preoptic region and the cerebral cortex of rats kept in normal laboratory conditions (ambient temperature 22 +/- 0.5 degrees C, 12 h:12 h light-dark cycle) and, during wakefulness, in the preoptic region of rats exposed to extended light and dark periods (i.e. dark in the light hours of the normal photoperiod, and light in the dark hours of the normal photoperiod). The results show that the concentration of cAMP in the preoptic region changes according to the ultradian wake-sleep cyclic, decreasing from wakefulness, through synchronized sleep and to desynchronized sleep. This pattern of change was found to occur both in light and dark hours, however, in the dark hours the levels of preoptic cAMP are higher than those observed in the light hours. In contrast, no significant modification in cAMP concentration was found in the cerebral cortex. In the extended light and dark periods preoptic cAMP concentration increases above the levels found during wakefulness in normal photoperiods. These results show that preoptic cAMP concentration is influenced by ultradian and circadian factors which also appear to be related to sleep processes.
Assuntos
Ciclos de Atividade , Ritmo Circadiano , AMP Cíclico/metabolismo , Área Pré-Óptica/metabolismo , Animais , Escuridão , Luz , Masculino , Concentração Osmolar , Ratos , Ratos Endogâmicos , Fases do Sono/fisiologiaRESUMO
The concentration of adenosine 3':5' cyclic monophosphate (cAMP) was determined in the anteroventro-medial hypothalamus, the cerebral cortex, the pineal gland and the interscapular brown adipose tissue, during the different stages of the wake-sleep cycle of rats kept, under a 12-12-h light-dark cycle, in different environmental conditions, i.e., control (47-52 h at ambient temperature (Ta) 23 +/- 0.5 degrees C), exposure (47-52 h at Ta 0 +/- 1 degree C) and recovery (1-4 h at Ta 23 degrees C after 48 h at Ta 0 degree C). The results show that cAMP concentration consistently changed: (1) during the wake-sleep cycle in the anteroventro-medial hypothalamus, decreasing from wakefulness to sleep; (2) during the dark-light transition in the pineal gland, increasing with the onset of the light phase; and (3) with the environmental condition in the interscapular brown adipose tissue increasing, with respect to the control condition, in exposure and recovery. No significant changes in cAMP concentration were observed in the cerebral cortex.
Assuntos
Tecido Adiposo Marrom/metabolismo , Encéfalo/metabolismo , AMP Cíclico/metabolismo , Fases do Sono/fisiologia , Temperatura , Vigília/fisiologia , Animais , Córtex Cerebral/metabolismo , Hipotálamo/metabolismo , Masculino , Fotoperíodo , Glândula Pineal/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
This study was carried out in order to further test the hypothesis that the occurrence of REM sleep in the rat in the form of episodes separated by long intervals (single REM sleep episodes) and by short intervals (sequential REM sleep episodes) is differently influenced by changes in both sleep and ambient related processes. Rats were studied during the exposure to Ta -10 degrees C for 24 or 48 h and during a 12 h recovery period at laboratory Ta (23 degrees C) following either the first or the second 24 h of cold exposure. The exposure to such a low Ta induced an almost complete abolition of REM sleep which was followed, during recovery, by a marked REM sleep rebound. However, in spite of the larger REM sleep deprivation, the REM sleep rebound was weaker following the 48 h-exposure than that following the exposure for 24 h. The increase in the amount of REM sleep during the recovery period was due to an increase in the amount of that occurring in the form of sequential episodes, whilst that in the form of single episodes did not change with respect to control levels. However, the occurrence of REM sleep in the form of sequential episodes was partially impaired during the REM sleep rebound observed in the recovery period following the 48 h-exposure. These results would suggest that the homeostatic regulation of physiological variables may conflict with that of REM sleep occurrence and that the degree of such a contrast is indicated, at low Ta, by the amount of REM sleep in the form of single episodes and, during the following recovery, by the amount of REM sleep in the form of sequential episodes.
Assuntos
Sistema Nervoso Autônomo/fisiologia , Temperatura Baixa , Sono REM/fisiologia , Animais , Homeostase/fisiologia , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
The effects of the rhythmical delivery of an auditory stimulus (1000 Hz, from 50 to 100 dB, 20 ms, every 20 s) on the pattern of rapid eye movement (REM) sleep occurrence was studied in the rat. The stimulation was simultaneously carried out on pairs of rats over 5 consecutive days (10-h recording sessions), during which a tone of increasing intensity (50, 63, 75, 88, 100 dB) was used. In each experimental session, auditory stimulation was triggered by the REM sleep occurrence of one rat (REMS-selective stimulation) whilst the other rat simultaneously received the same stimuli, but during any stage of the wake-sleep cycle (REMS-unselective stimulation). The results showed that the total amount of REM sleep in the 10-h recording session was increased over the 5 days of stimulation in the REMS-unselective group. This effect was due to an increase in the mean duration of REM sleep episodes. However, no significant changes were observed in animals under REMS-selective stimulation, nor in a third group of animals in which the spontaneous evolution of REM sleep occurrence (REMS-spontaneous) was studied. Since 86% of the stimuli under the REMS-unselective auditory stimulation fell outside REM sleep, the result would suggest that REM sleep occurrence is affected when the stimuli are delivered during a time period (i.e. during wakefulness or non-REM sleep) in which it is well known that physiological regulations are fully operant.
Assuntos
Sono REM/fisiologia , Estimulação Acústica , Animais , Vias Auditivas/fisiologia , Encéfalo/fisiologia , Eletroencefalografia , Masculino , Periodicidade , Ratos , Ratos Sprague-DawleyRESUMO
The pattern of desynchronized sleep (DS) occurrence in the rat was studied during exposure to an ambient temperature (Ta) of 0 degrees C for 48 h and during a 12 h recovery period at laboratory Ta (23 degrees C) following the first and second 24 h of cold exposure. The exposure to low Ta induces a DS deprivation which is followed, during recovery, by a clear DS rebound. Both the decrease and the following increase in the amount of DS are due to changes in the frequency rather than in the duration of DS episodes. The frequency distribution of the intervals between the end of one DS episode and the beginning of the next (DS interval) has shown that two populations of DS intervals exist, i.e. short DS intervals (=3 min) and long DS intervals (>3 min). On the basis of this, two types of DS episodes have been identified: the 'single DS episode', which is both preceded and followed by a long DS interval, and the 'sequential DS episode', which is a DS episode occurring within a cluster or a sequence of DS episodes and is characteristically separated by short DS intervals. The occurrence of such sequential DS episodes in a 'DS cluster', allows a high amount of DS to occur without increasing the duration of the DS episode. DS clusters are repressed during cold exposure, when the DS drive is counteracted by the need to thermoregulate, and enhanced during recovery, when the DS drive is unrestrained. In contrast, the occurrence of single DS episodes is much less affected by such different experimental conditions.
RESUMO
The history of Italian parasitology can be subdivided into two periods: pre-Redi and post-Redi. The first period includes the contributions to parasitology by savants who operated during the Roman, medieval and Renaissance eras; the second period started in 1668 when Francesco Redi published his experiments to debunk the theory of spontaneous generation; the work of Redi was subsequently continued by Vallisnieri, Spallanzani and others. The latter period includes classic contributions in the field of parasitology provided by veterinarians such as Ercolani, Perroncito, Piana and Rivolta, and by physicians such as Bassi, Grassi, Golgi, and Celli. Also, two outstanding pages of medical parasitology were written during this period--the unraveling and defeat of St. Gotthard's disease and the conquering of malaria on Italian soil--both accomplished through the generous efforts of dedicated individuals.
Assuntos
Parasitologia/história , Ancylostoma/crescimento & desenvolvimento , Ancilostomíase/história , Animais , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História Antiga , História Medieval , Humanos , Itália , Malária/história , Plasmodium malariae/crescimento & desenvolvimentoRESUMO
Paradoxical embolization of venous thrombus into the abdominal aortic bifurcation has been diagnosed by means of aortography. Lower limb phlebothrombosis accounting for the embolus formation has been demonstrated by phlebography. Arterial embolectomy and venous thrombectomy were successfully performed. Recovery was complete without sequelae.
Assuntos
Doenças da Aorta/etiologia , Embolia/etiologia , Tromboflebite/complicações , Adulto , Doenças da Aorta/diagnóstico , Doenças da Aorta/cirurgia , Embolia/diagnóstico , Embolia/cirurgia , Feminino , Veia Femoral , HumanosRESUMO
The flea has been, indirectly, one of the protagonists in the history of man. As one of the two vectors of Yersinia pestis, the etiological agents of the Black Death, the flea (Xenopsylla cheopis) has contributed, over the centuries, to the death of millions of people in many countries. Galileo Galilei was the first to observe the flea with a microscope (1624), but the credit of depicting it with a stunning drawing goes to the Britisher Robert Hooke in 1665. A number of zoologists, including Antonie Van Leeuwenhoek and Diacinto Cestoni, well described and illustrated the life cycle of the flea in the XVII century. Some of these reports inspired scholars such as J. Swift and J. Donne for the composition of classic poems. Also, the flea, alone and with its hosts, has inspired a number of artists to create fine paintings; among them: G. M. Crespi, G. B. Piazzetta, G. de la Tour and others. Colorful sonnets on the flea in the Roman dialect were written by G. Belli and Trilussa. The flea also, as a theme, inspired musicians such as G. F. Ghedini and M. Mussorgsky, play writers such as Feydeau and moviemakers such as Charlie Chaplin. The flea is, indissolubly, connected with the history of Black Death. This disease in man is, in fact, caused--as demonstrated by Yersin and Simond--by the triad: bacterium (Yersinia pestis)/rat/flea (Xenopsylla cheopis). Over the centuries, Black Death has had a deep impact on both the visual arts and literature and, as a result, a very large number of paintings and other works of art have been produced to remember these tragic episodes. In the field of literature, Black Death has been skillfully described by writers such as Boccaccio, Manzoni and Camus. Finally, in recent years, following the discovery of the existence of a large market for the control of fleas in small animals, the interest in this minute insect has been resurrected and, parallel to that, the rebirth of the flea iconography, through electromicroscopy, has also taken place.
Assuntos
Medicina na Literatura , Medicina nas Artes , Sifonápteros , Argélia/epidemiologia , Animais , Arábia , Doenças do Gato/parasitologia , Doenças do Gato/prevenção & controle , Gatos , Surtos de Doenças/história , Doenças do Cão/parasitologia , Doenças do Cão/prevenção & controle , Cães , Ectoparasitoses/complicações , Ectoparasitoses/história , Ectoparasitoses/parasitologia , Ectoparasitoses/veterinária , Europa (Continente)/epidemiologia , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , História Antiga , História Medieval , Humanos , Controle de Insetos/história , Insetos Vetores/microbiologia , Peste/epidemiologia , Peste/história , Peste/microbiologia , Peste/transmissão , Ratos , Rickettsia typhi/fisiologia , Doenças dos Roedores/microbiologia , Sifonápteros/microbiologia , Tifo Endêmico Transmitido por Pulgas/microbiologia , Tifo Endêmico Transmitido por Pulgas/veterinária , Yersinia pestis/fisiologiaRESUMO
Sleep deprivation and recovery induce, in the hypothalamic preoptic region of the rat, opposite changes in cyclic AMP concentration which, when plotted in the standard form of the normal distribution, define two significantly divergent distributions. Thus, these opposite functional conditions may be related to corresponding changes in a biochemical parameter within an area involved in the control of the sleeping-waking cycle.
Assuntos
AMP Cíclico/metabolismo , Área Pré-Óptica/metabolismo , Sono/fisiologia , Animais , Ritmo Circadiano , Concentração Osmolar , Lobo Parietal/metabolismo , Privação do Sono/fisiologiaRESUMO
Echocardiography (M-mode and 2-dimensional) has identified unusual cardiac anomalies which, not related with cardiac murmurs or clicks or other clinical marks, had not been elsewhere discovered. Among them there is the atrial septal aneurysm, which often occurs with other cardiac malformations (congenital or acquired), but sometimes occurs as an isolated abnormality. The Authors report a case of isolated atrial septal aneurysm, detected in a 6 year-old boy.
Assuntos
Aneurisma Cardíaco , Átrios do Coração , Cardiomiopatias/diagnóstico por imagem , Criança , Ecocardiografia Doppler , Eletrocardiografia , Aneurisma Cardíaco/diagnóstico por imagem , Humanos , MasculinoRESUMO
Since REM sleep is characterized by a suspension of the hypothalamic integration of homeostatic regulations, it has been assumed that the duration of both REM sleep episodes and of the time interval between the end of one episode and the beginning of the following episode may be regulated according to sleep related processes and the homeostatic needs of the organism. A series of studies performed on the rat has shown that REM sleep episodes occur as two basic types: single REM sleep episodes, that are separated by intervals > 3 min and sequential episodes, that are separated by intervals < or = 3 min and appear in a cluster. Moreover, it has been observed that, in this species, a change in REM sleep occurrence is caused by a modification in the number of episodes and not in their duration. With respect to this, sleep deprivation and recovery are characterized by a decrease and an increase, respectively, in the number of sequential REM sleep episodes, but the number of single episodes tends to be kept constant. The central aspects of this kind of regulation have been examined biochemically in the preoptic-anterior hypothalamus, an area involved in the control of autonomic and sleep related processes. The results show that the accumulation of adenosine 3':5'-cyclic monophosphate (cAMP) is impaired, in this region, during sleep deprivation and appears to return to the control levels, during the recovery, with a rate inversely related to the degree of the previous deprivation. Moreover, it has been observed that the systemic administration of DL-propranolol and LiCl reduces cAMP accumulation mainly in the preoptic-anterior hypothalamus; this condition is concomitant with a reduction in REM sleep occurrence.