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Biomedical subjects

C Font

Publications and source records attributed to C Font.

36 records · Page 2Linked to original sources
PubMed1997

A lacertilian dorsal retinorecipient thalamus: a re-investigation in the old-world lizard Podarcis hispanica.

The aim of this work is to delineate the retinorecipient cell groups of the dorsal thalamus of lizards and to study some of the differential connections in order to help to understand the evolution of the visual system in tetrapods. Tract-tracing and immunohistochemical techniques were applied to the retinorecipient dorsal thalamus of the lizard Podarcis hispanica. The retina of Podarcis projects to four areas of the dorsal thalamus: nucleus ovalis (Ov), intergeniculate leaflet (IGL), dorsal lateral geniculate nucleus (GLD) and dorsolateral anterior nucleus (DLA). Nucleus ovalis shows a clear cell plate/neuropile organization and projects to the ventral thalamus. Thus, it seems to belong to the ventral rather than to the dorsal thalamus. The IGL contains large cells reactive for GABA and/or NPY immunohistochemistry. It is interconnected with the supra/retrochiasmatic hypothalamus and projects to the opposite thalamus and to the ipsilateral tectum. The caudal DLA, which lacks both GABA- and NPY-like immunoreactive cells, is reached by a few thin retinal fibers, although distal dendrites of DLA cells enter the GLD, suggesting an important retinal input. The DLA projects to the medial and dorsal telencephalic cortices. The GLD is the main retinorecipient thalamic structure that projects to the telencephalon. It shows a crude laminar organization in which cell plate neurons project to the ipsilateral pallial thickening, but it does not receive a descending projection from the visual telencephalon and thus differs from the GLD of other amniotic vertebrates. In the context of present knowledge, these results suggest that an IGL homologue is present in all tetrapods studied, whereas Ov seems to be restricted to diapsid vertebrates. Moreover, our data suggest that a unimodal visual projection to the telencephalon (arising from the GLD) first appeared in reptiles by segregation from a limbic (multimodal) thalamo-telencephalic pathway.

Animals↗
PubMed1996

Hodgkin's disease presenting as a cholestatic febrile illness: incidence and main characteristics in a series of 421 patients.

In order to determine the frequency and characteristics of patients with liver abnormalities as the presenting manifestation of Hodgkin's disease (HD), 421 consecutive HD patients were studied. Six patients in the series (1.4%) presented with liver abnormalities that led to of a liver biopsy and the subsequent diagnosis of HD. All had fever prior to HD diagnosis, four frank jaundice, and one hepatic failure. No patient had pruritus. Moderate hepatomegaly was present in four patients. Cholestasis was observed in all cases; in most patients a moderate increase in the transaminase activity was also seen. Two patients had a mild rise in the serum LDH, four had leukopenia, and one eosinophilia. At liver histologic study, Reed-Sternberg cells were demonstrated in four patients; in the remaining two, the presence of atypical histiocytes, lymphocytes, and eosinophils was highly suggestive of HD, the latter diagnosis being confirmed by subsequent study of bone marrow and/or retroperitoneal lymphadenopathies. In three of the six patients, HD was not demonstrated in sites other than the liver. Three patients older than 60 years died shortly after HD diagnosis. By contrast, three patients younger than 40 years showed a dramatic response to chemotherapy: two of them had a further relapse, and one is considered cured after 14 years of continuous remission. Liver disease constitutes an infrequent form of HD presentation which must be included in the differential diagnosis of any patient with fever of unknown origin.

Adult↗
PubMed1996

Catecholaminergic interplexiform cells in the retina of lizards.

An immunohistochemical study of the distribution of tyrosine hydroxylase has been performed in the retina of lizards of the genera Podarcis, Anolis and Tarentola. Immunoreactive cells extending their processes into the inner plexiform layer were observed in all three species. Reactive fibres in the outer plexiform layer were also seen in Podarcis and Anolis, and hence they possess not only amacrine but also catecholaminergic interplexiform cells. The retina of Anolis also showed reactive fibres aposed to the photoreceptors near the central fovea. The role of this outer retinal innervation on dopamine-dependent light-adaptive phenomena is discussed from a comparative perspective.

Animals↗
PubMed1996

Polyarteritis nodosa in human immunodeficiency virus infection: report of four cases and review of the literature.

Four patients with HIV infection were diagnosed as having panarteritis nodosa type vasculitis in muscle samples taken by biopsy. Fever, weight loss and neuromuscular symptoms were the major complaints. All but one were successfully treated with a low dose of prednisone. The other patient refused treatment, but her muscular complaints did not worsen during 9 months of follow-up. Previously reported cases in the literature are reviewed.

Adult↗
PubMed1996

Von Willebrand factor in the outcome of temporal arteritis.

OBJECTIVE: To determine fluctuation in circulating von Willebrand factor (vWF) in the outcome of patients with temporal arteritis. METHODS: Plasma vWF antigen concentrations were measured in 65 patients with biopsy proven temporal arteritis at different disease activity stages, in 12 with isolated polymyalgia rheumatica, and in 16 controls. Fourteen temporal arteritis patients underwent serial determinations during the course of their disease. RESULTS: vWF concentrations were significantly raised in temporal arteritis (mean 220 [arbitrary units], range 96 to 720) and in polymyalgia rheumatica (mean 196, range 103 to 266) compared with healthy controls (mean 98, range 75 to 137) (P < 0.05). Although vWF values tended to be higher in temporal arteritis, no significant differences were found between temporal arteritis and polymyalgia rheumatica patients nor between temporal arteritis patients with ischaemic complications (mean 269, range 130 to 720) and those who presented with polymyalgia rheumatica or constitutional symptoms only (mean 179, range 140 to 220). The highest levels were obtained in patients with associated, mainly infectious, diseases (mean 631, range 240 to 1680). Raised vWF values found in active temporal arteritis patients (mean 220, range 96 to 720) persisted within the first two years after the beginning of treatment (mean 244, range 102 to 510) but tended to normalise in patients in long term remission (mean 143, range 50 to 260). CONCLUSIONS: Persistent elevation of vWF during early remission of temporal arteritis might represent an endothelial activation status induced by a remaining inflammatory microenvironment rather than a marker of endothelial cell injury. In long term remission, decreasing vWF concentrations might reflect progression of inflammatory lesions to a healing stage.

Acute Disease↗
PubMed1995

The septal complex of the telencephalon of the lizard Podarcis hispanica. I. Chemoarchitectonical organization.

In this paper we study the septal complex architecture in the lizard Podarcis hispanica (Lacertidae). Histochemical and immunohistochemical techniques were used to define the distribution of zinc (Timm stain), acetyl cholinesterase (AChase), gamma-aminobutyric acid (GABA), tyrosine hydroxylase (TH), dopamine (DA), serotonin (5-HT), and two neuropeptides: leu-enkephalin (L-ENK) and substance P (SP). These reactions delineate a coherent map of nine septal nuclei that are named with a topographical nomenclature: anterior, lateral, ventromedial, medial, dorsolateral, ventrolateral, and dorsal septal nuclei, nucleus septalis impar, and nucleus of the posterior pallial commissure. The anterior septal nucleus is characterized by intense reaction for zinc and the presence of fibers immunoreactive for GABA, 5-HT, and L-ENK, which form pericellular nests. The lateral septal nucelus shows intense reaction for zinc, a high density of GABA-immunoreactive cells, and L-ENK-immunoreactive fibers forming basketlike figures around unstained somata. The ventromedial septal nucleus shows intense AChase reactivity, a dense network of 5-HT-immunoreactive fibers, and virtually no labeling for the other histochemical stains. The medial septal nucleus is defined by heavy reactivity for zinc, dense DA/TH and L-ENK innervations, and the presence of L-ENK-immunoreactive cells. The dorsolateral septal nucleus shows intense AChase staining in the neuropile and a dense network of fibers immunoreactive for 5-HT and DA/TH, but it shows low staining for zinc. The ventrolateral septal nucleus shows L-ENK-immunoreactive cells and a dense L-ENK innervation, but low reactivity for zinc. The dorsal septal nucleus, intermingled with the fimbrial fibers, shows a dense population of GABA-immunoreactive cells and terminals, but it is unreactive for zinc. Two subdivisions can be established in this dorsal septal nucleus: the dorsal part, intensely reactive for AChase and innervated by 5-HT fibers, and the central part, which shows L-ENK-immunoreactive neurons and fibers without reactivity for either AChase or 5-HT. The nucleus septalis impar, traversed by the fibers of the anterior pallial commissure (mildly reactive for zinc), shows reaction for AChase but low (if present) reactivity for the remaining markers. The nucleus of the posterior pallial commissure shows a generally low reactivity for the histochemical reactions employed. The distribution of these markers is similar to that found in other squamate reptiles and allows for a direct comparison with the septal formation of mammals. Such a comparison reinforces the view that the limbic system has undergone a conservative evolution within vertebrates.

Acetylcholinesterase↗
PubMed1995

Pneumonia in ventilated head trauma patients: the role of thiopental therapy.

The role of barbiturate therapy in the development of pneumonia in head trauma patients in the intensive care unit of a university hospital was studied retrospectively. A total of 151 ventilated head trauma patients were included in the study. Intravenous thiopentone was administered to 75 patients (Group A), and 76 patients were managed without thiopentone therapy (Group B). Pneumonia was diagnosed when a new persistent pulmonary infiltrate appeared, with at least two of the following: (a) fever greater than 38 degrees C, (b) a white blood cell count greater than 15,000/mm3, or (c) the presence of purulent bronchial secretions. On admission, there were no differences in the acute physiology and chronic health evaluation 2 revision (APACHE II) and Glasgow Coma Score between Groups A and B. Fifty-three per cent of the patients treated with thiopentone (Group A) developed pneumonia compared with 35% in Group B (odds ratio 1.85, 95% confidence interval 0.97-3.51). Gram-negative and Staphylococcus aureus organisms were the most frequently isolated in all cases. No differences in age, sex, APACHE II, Glasgow Coma Score, nutritional status or dexamethasone treatment were observed between the groups with and without pulmonary infection. In the multivariate analysis, prolonged mechanical ventilation before pneumonia and thiopentone treatment remained as the only independent risk factors for the appearance of pneumonia in head trauma patients (p = 0.001 for both). Nevertheless, thiopentone did not increase the rate of mortality in patients with pneumonia. In conclusion, head trauma victims treated with thiopentone have a greater risk for the development of nosocomial pneumonia independent of mechanical ventilation.

Adolescent↗
PubMed1994

Seasonal sexually dimorphic distribution of neuropeptide Y-like immunoreactive neurons in the forebrain of the lizard Podarcis hispanica.

Since neuropeptide Y (NPY) is involved in several sex-specific physiological and behavioral processes, a sexual dimorphic distribution is expected in forebrain areas that take part in the control of reproduction physiology and sexual behavior. This question has been studied in the lizard Podarcis hispanica by comparing the distribution of NPY-like immunoreactive cells in several forebrain areas of males and females during the season of active (spring/summer) and inactive (fall/winter) reproductive activity. Both qualitative observations and statistical analysis (analysis of variance) indicate that the number of reactive cells within two forebrain areas, the lateral septum and the periventricular preoptic nucleus, depends on the sex (P = 0.02) and season (P = 0.03) and that, in fact, intersexual differences depend on the season of the reproductive annual cycle (P = 0.046). Other areas, such as the amygdaloid nucleus sphericus, show neither sexual dimorphism (P = 0.67), nor seasonal variation in the number of reactive cells (P = 0.18), nor seasonal variation of the intersexual differences (P = 0.75). When analyzed independently, the lateral septum shows a clear sexual dimorphism in favour of females (P = 0.003) whereas the number of reactive cells in the periventricular preoptic nucleus is significantly higher (P = 0.006) in males than in females. In the case of the preoptic nucleus, this sexual dimorphism is clearly accentuated during the season of reproductive activity (P = 0.007), but this dependence is not so clear for the lateral septum (P = 0.059).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Program for helping the smoker in primary care. Preliminary evaluation].

The program of help to the smoker (PHS) consists of a systematic intervention upon the whole of the demanding population, identifying the smokers and acting on them with a short, concise advise in all visits. The results after 2 months of operation of the PHS in a primary care center are reported. Among 483 persons 104 smokers were detected (23.65%). 27% showed a favorable disposition towards quitting smoking within a short term; only 17% declared to be against quitting. The best response (36.8% of favorable responses) was obtained in the group smoking 20 cigarettes per day or more. The reported data suggest that the PHS could be useful both in heavy and in minimal or moderate smokers. We consider these data as a preliminary evaluation; assessment with data of long term cessation from smoking is required.

Adolescent↗
PubMed1985

[Hypotension and diffusion of Rb-86 in the rat brain].

Studies on the permeability of potassium at the blood-brain barrier of rats show that, under normal conditions, the concentration of this ion is kept constant although wide variations in plasma are present. 86Rb has been utilized as an analog of K+. The permeability constant for control animals (arterial blood pressure of 100 +/- 3 mmHg), has been determined in 0.926 +/- 0.02 ml X g-1 X h-1 (brain cortex), and 1.107 +/- 0.12 ml X g-1 X h-1 (cerebellum). The permeability constant for hypotensive animals (arterial blood pressure of 40 +/- 5 mmHg), has been determined in 0.473 +/- 0.03 ml X g-1 X h-1 (brain cortex), and 0.608 +/- 0.06 ml X g-1 X h-1 (cerebellum). During hypotension there is a marked decrease in the permeability constant of 86Rb at the blood-brain barrier of rats.

Animals↗
PubMed1982

[Simultaneous diffusion of inositol and mannitol in the rat brain].

The diffusion of both inositol and mannitol has been determined simultaneously by the integral bolus method in rat brain. The permeability constant (Kin) of inositol averaged 0.27 +/- 0.02 ml X (100 g)-1 X min-1 or 4 X 10(-7) cm X s-1 at a cerebral capillary surface area of 100 cm2 x g-1. The permeability of mannitol was 0.08 +/- 0.01 ml X (100 g)-1. min-1 or 1 X 10(-7) cm X s-1. Neither glucose nor galactose affected the inositol permeability. Hypoglycemia increased somewhat the Km value for mannitol. The basal ganglia showed an increase Km for both substrates as compared with those obtained for cortex, temporal and parietal tissues.

Animals↗
PubMed1981

Is the retrograde axonal transport of 3H-5-HT a specific process of serotoninergic neurons?

The specificity of the retrograde axonal transport of 3H-serotonin (3H-5-HT) was radioautographically studied in the afferents to the olfactory bulb (O.B.). Injections of 3H-5-HT of different concentrations (10(-2), 10(-3), 10(-4) and 10(-5) M) were performed into the O.B. of catron pretreated rats. Following injection of 3H-5-HT (10(-2) M), a cytoplasmic perikaryal labeling was observed in the bulk of afferents to the O.B. (aminergic and non-aminergic neurons). When lower concentrations of 3H-5-HT (10(-5) M) were injected into the O.B., the retrograde labeling was only seen in the raphe dorsalis (RD) serotoninergic perikarya. The specificity of the uptake-retrograde transport of 3H-5-HT seems to depend on the selectivity of uptake by nerve terminals.

Afferent Pathways↗
PubMed1980

Retrograde axonal transport following injection of [3H]-serotonin into the olfactory bulb. II. Radioautographic study.

Radioautography was used to study the intraneuronal distribution of [3H]-serotonin (5-HT) and/or its derivatives selectively taken up by the olfactory bulb (OB) serotonergic terminals and subsequently transported to their parent cell bodies in the midbrain raphe nuclei. This was done 24 h after injection of [3H]5-HT into the main OB of rats either pretreated or not with monoamine oxidase (MAO) inhibitor. A prior mechanical obstruction of the rostral ventricular cavities prevented diffusion of the tracer towards cerebrospinal fluid. Heavily labelled nerve cell bodies were found mainly in the ipsilateral raphe dorsalis nucleus (RDN) and to a lesser extent in the raphe centralis nucleus. The radioautographic reaction often extended to dendritic processes while sparing the nucleus. A diffuse reaction was also observed but limited to the raphe area. The supraependymal 5-HT fibers were found to be free of labelling. Neither local destruction of catecholaminergic terminals with 6-OHDA, nor absence of MAO inhibition, impaired this radioautographic pattern, while destruction of serotonergic terminals with 5,6-dihydroxytryptamine in OB resulted in the disappearance of labelled axonal varicosities and neurons in the OB and the RDN respectively. At the electron microscopy level, labelled cell bodies in the RDN were medium-sized (12-15 micrometers). Silver grains were localized mainly on mitochondria and, to a lesser extent, on lysosomes and endoplasmic reticulum but spared the nucleus and the nucleolus. Silver grains were also found near the nuclear membrane and outside the neuronal membrane. The observation of heavy metal impregnated thick sections confirmed the preferential localization of silver grains on mitochondria with or without inhibition of MAO. These results could account for the subcellular compartments involved in the retrograde axonal transport of [3H]5-HT and its subsequent degradation and/or dendritic release.

Animals↗
PubMedDate not supplied

[Employees attitudes to workplace health promotion programs for cancer prevention].

OBJECTIVE: [corrected] We describe a method for feasibility assessment of workplace health promotion (WHP) programs as a necessary prerequisite of any WHP program. METHODS: A total of 167 employees from five workplace communities participated in the study. A questionnaire on the basic components of feasibility (risk factors, attitudes to workplace health promotion interventions, and social-occupational context) was administered. RESULTS: Risk behaviours were common among the employees interviewed. Health promotion in the workplace was favorably viewed by 79% of subjects but reported participation would be lower. Interventions on diet and physical activity received the highest acceptance. Participation would be greatest among local administration employees. CONCLUSIONS: The method demonstrated its utility in obtaining useful data for designing workplace health promotion interventions.

Adolescent↗
PubMedDate not supplied

Ascending projections from the optic tectum in the lizard Podarcis hispanica.

The ascending projections of the optic tectum, including their cells of origin, have been studied in the lizard Podarcis hispanica by means of a two-step experimental procedure. First, tracers were injected in the tectum to study the anterograde labeling in the forebrain. Second, the cells of origin of these projections have been identified by analyzing the retrograde labeling after tracer injections in the thalamus, hypothalamus, and pretectum. Three main tectal ascending pathways have been described: the dorsal tecto-thalamic tract (dtt), the medial tecto-thalamic tract (mtt), and the ventral tecto-thalamic tract (vtt). The dtt originates in radial cells of layers 5 and 7 and bipolar cells of layers 8 and 10 that project to the lateral neuropile of the dorsal lateral geniculate nucleus (GLD), to the intergeniculate leaflet (IGL), and to the ventral lateral geniculate nucleus (GLV). The mtt arises from radial neurons of layers 3 and 5 and bilaterally reaches the putative reticular thalamus and its boundary with the hypothalamus, the rostral IGL, and the area triangularis (AT). The vtt is composed of fibers from ganglion and multipolar cells of the layer 7 that project bilaterally to the nucleus of the vtt, the ventrolateral thalamic nucleus, the medial posterior thalamic nucleus (MP), the nucleus rotundus (Rot), the IGL, and the cell plate of the GLD. Therefore, the GLD receives not only direct retinal afferents but also two different tectal inputs, thus constituting a convergence point in the two visual pathways to the telencephalon. Moreover, different tectal cells specifically project to the ventrolateral thalamus and to pretectal nuclei. These results are discussed from comparative and functional viewpoints.

Animals↗