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Biomedical subjects

B Rico

Publications and source records attributed to B Rico.

13 recordsLinked to original sources
PubMed1999

Distribution of acetylcholinesterase and choline acetyltransferase in the main and accessory olfactory bulbs of the hedgehog (Erinaceus europaeus).

The distribution of cholinergic markers was studied in the main olfactory bulb (MOB) and accessory olfactory bulb (AOB) of the western European hedgehog (Erinaceus europaeus) by using choline acetyltransferase (ChAT) immunocytochemistry and acetylcholinesterase (AChE) histochemistry. A dense network of AChE-containing and ChAT-immunoreactive fibers was observed innervating all layers of the MOB except the olfactory nerve layer, where neither AChE- nor ChAT-labeled elements were found. The highest density of AChE- and ChAT-positive axons was found in the glomerular layer (GL)/external plexiform layer (EPL) boundary, and in the internal plexiform layer. This general distribution pattern of ChAT- and AChE-stained axons resembled the distribution pattern found in rodents. Nevertheless, some interspecies differences, such as the lack of atypical glomeruli in the hedgehog, were also found. In addition to fibers, a population of noncholinergic and presumably cholinoceptive AChE-active neurons was observed in the hedgehog. All mitral and tufted cells of the hedgehog MOB showed a dark AChE staining unlike previous observations in the mitral and tufted cells of rodents. As in other species previously reported, subpopulations of external tufted cells and short-axon cells were also AChE-active. Finally, a population of small AChE-containing cells was observed in the EPL of the hedgehog MOB. The size, shape, and location of these cells coincided with those of satellite and perinidal cells, two neuronal types described previously in the EPL of the hedgehog and not present in the rodent MOB. The AOB of the hedgehog showed a distribution of AChE- and ChAT-positive fibers similar to the rodent AOB. Nevertheless, a heterogeneous innervation of vomeronasal glomeruli by bundles of AChE- and ChAT-labeled axons found in the hedgehog has not been previously found in any other species. As in the MOB, all mitral cells in the AOB showed a strong AChE activity. These results demonstrate some similarities but also important differences between the distribution of ChAT and AChE in the MOB and AOB of rodents and this primitive mammalian. These variations may indicate a different organization of the cholinergic modulation of the olfactory information in the insectivores.

Acetylcholinesterase↗
PubMed1998

Adrenergic innervation of the monkey thalamus: an immunohistochemical study.

The distribution and function of the neurotransmitter adrenaline in the primate brain are poorly understood. Biochemical studies have shown the presence of adrenaline or its biosynthetic enzyme, phenylethanolamine-N-methyltransferase, in the rat and human thalamus. However, the distribution of the adrenergic fibres in the thalamus has only been demonstrated in rats. We study the adrenergic innervation of the macaque monkey thalamus using immunohistochemistry against phenyletanolamine-N-methyltransferase. The distribution of phenyletanolamine-N-methyltransferase-immunoreactive fibres is markedly heterogeneous and principally restricted to those nuclei, or their portions, that are located in or close to the midline, with the highest density being found in the paraventricular, parafascicular and mediodorsal nuclei. The paraventricular nucleus is densely innervated by adrenergic axons throughout, while the densest innervation of the parafascicular nucleus is located in its medial part and the strongest mediodorsal nuclear immunolabelling is found in its most posterior and medial region. Moderate or low concentrations of phenyletanolamine-N-methyltransferase-immunopositive fibres are present in the paratenial nucleus, and all parts of the central nucleus, nucleus reuniens, central medial nucleus, centromedian nucleus, medial geniculate body and medial pulvinar nucleus, while only scattered immunoreactive axons are found in other thalamic nuclei. The morphology of the phenyletanolamine-N-methyltransferase-immunoreactive axons is quite diverse, as they have different diameters and most are endowed with diversely-shaped varicosities. These findings are the first morphological evidence for the presence of adrenergic innervation in the primate thalamus and reveal that this innervation is highly selective, heterogeneous and more widely distributed in primates than in rats. The thalamic nuclei innervated by adrenaline are connected to widespread limbic and associative cortical areas as well as to subcortical structures, in particular the neostriatum and amygdala. We hypothesize that thalamic adrenaline may be implicated in emotional, social and attentional mechanisms through its facilitation of co-ordinated action by these brain regions.

Animals↗
PubMed1998

A population of cholinergic neurons is present in the macaque monkey thalamus.

Three new cholinergic markers were employed to study the cholinergic innervation in the thalamus of adult macaque monkeys. They were: two antibodies against choline acetyltransferase (ChAT), one polyclonal and one monoclonal; and a polyclonal antibody against the vesicular transporter of acetylcholine (VAChT), a powerful new marker that colocalizes with ChAT. This approach led to an unexpected finding: the three antibodies positively immunostained a population of neurons in the paracentral nucleus. The immunostained cells are confined to the dorsal region of this nucleus along its rostrocaudal extent. Measurement of the somatic areas of the immunostained neurons indicated that they correspond to a population of large neurons thought to be projection neurons. Because dorsal paracentral neurons are known to project to the dorsal striatum and specific cortical areas involved in visual and visuomotor mechanisms, these structures might be modulated by cholinergic thalamic neurons.

Animals↗
PubMed1996

Ultrastructural study of the Pacinian corpuscles in the newborn and adult dog forefoot.

Pacinian corpuscles (PC) of the newborn and adult dog forefoot were studied by electron microscopy. The PC of newborn dog forefoot show a rare development: they exhibit a lamellar arrangement, although the lamellar compartments do not surround completely the fiber. The outer core cells show a well-developed perinuclear endoplasmic reticulum. They are surrounded by a discontinuous basal lamina. Mast cells between the lamellae of the outer core are observed. Desmosome-like and zonula adherens junctions, as well as pinocytotic vesicles, are shown in the inner core cells. Intermediate filaments are also observed in the glial cells of the inner core. In PC of adult dog forefoot a general organization of a concentrically arranged capsule, outer core, intermediate layer and inner core around a nerve ending is always present. In the intermediate layer, lamellar cells (specialized fibroblast) do not surround completely the inner core. The inner core lamellae possess numerous pinocytotic vesicles, an extensive network of filaments, special cell junctions (gap, desmosome) and a discontinuous basal lamina. The present results show a conservative structural organization in PC, although differences among species are discussed.

Age Factors↗
PubMed1995

Study of Fc gamma murine macrophage receptors (Fc gamma R) in the internalization of Histoplasma capsulatum yeasts.

Reports about Fc gamma R involvement in the phagocytosis of Histoplasma capsulatum yeast are contradictory. Fungal cells were incubated with anti-Histoplasma murine IgG or normal IgG as control. The opsonized yeasts were adjusted and spread on a J774.2 macrophage cell line monolayer. Yeast cells were allowed to attach to the monolayers at 4 degrees C for 1 h prior to initiating the internalization step of the phagocytic process, by shifting the cells to 37 degrees C. The participation of Fc gamma R in the internalization of yeast was monitored by radioiodination labelling of the macrophage surface proteins, and rosette-forming cells for erythrocytes coated with antibodies (RFC-EA). Results showed decreased [125I]-incorporation on the macrophage surface proteins at 15 min post-anti-Histoplasma IgG opsonized yeast infection. The same was observed when high and low virulent H. capsulatum strains were used. A decrease of RFC percentage was also observed at 15 min after IgG opsonized yeast phagocytosis. Results support the disappearance of Fc gamma R at 15 min from the surface of the macrophage that had ingested anti-Histoplasma IgG opsonized yeasts. The recovery of [125I]-counts and the RFC response at a longer time of phagocytosis suggest a possible Fc gamma R recycling mechanism.

Animals↗
PubMed1992

[Children and AIDS].

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Synthesis and structural, conformational, and pharmacological study of some of esters derived from 3-phenethyl-3-azabicyclo[3.2.1]octan-8-beta-ol and the corresponding N-endo-methyl quaternary derivatives.

A series of 8-beta-acyloxy-3-phenethyl-3-azabicyclo[3.2.1]octane and its N-endo methiodides were synthesized and studied by 1H and 13C NMR spectroscopy, and the crystal structure of 8-beta-p-chlorobenzoyloxy-3-phenethyl-3-azabicyclo[3.2.1]octane methiodide (2c) was determined by X-ray diffraction. In CDCl3 solution, 1b-1e display the same preferred conformation. The cyclopentane and piperidine rings adopt an envelope conformation flattened at C-8 and a distorted chair conformation puckered at C-8 and flattened at N-3, respectively, with the N-substituent in the equatorial position with respect to the piperidine ring. In all cases, methylation takes place from the endo position. The ability of the title compounds to antagonize the acetylcholine-induced contraction of guinea pig ileum is also reported. An initial structure-activity relationship is proposed.

Animals↗
PubMed1989

Evaluation of phagolysosome fusion in acridine orange stained macrophages infected with Histoplasma capsulatum.

A phagosome-lysosome (PL) fusion was performed in vitro using peritoneal cells from normal BALB/c mice and the J774.2 macrophage cell line infected with the yeast phase of the fungus Histoplasma capsulatum at ratios of 5 x 10(5), 5 x 10(6) or 1 x 10(7) yeasts per 1 x 10(6) macrophages, and phagocytosis was allowed to proceed for 5, 30 and 60 min. Macrophage lysosomes were pre-labelled with acridine orange and the cells were challenged with the parasite. Fusion was evaluated by fluorescence microscopy and the number of macrophages with stained yeast cells was scored. The phagolysosome fusion frequency (PLFF) was calculated by subtracting the specific fusions of infected macrophages from the non-specific fusions of uninfected macrophages and normalizing the total number of bound yeasts. The PLFF was determined using different doses and strains of H. capsulatum. Results showed that PLFF in infected macrophages depends on the infection dose. Inhibition of PL fusion was detected mainly at a high infection ratio (1 x 10(7) yeasts/1 x 10(6) macrophages), and PL fusion varied with phagocytosis time. No significant differences were observed in the fusions when different Histoplasma strains were used. Results with J774.2 cells were similar to peritoneal cells, indicating that both methodology and fusion calculations employed were useful, in spite of the heterogeneity of macrophage populations used.

Acridine Orange↗
PubMed1989

AIDS in Mexico: trends and projections.

The first case of AIDS in Mexico was reported in 1981. Through mid-1988, 1,502 cases had been reported, the incidence of cases having doubled every 7.7 months. Of the cases in adults, 87.6% were sexually transmitted, transfusion with contaminated blood or blood products accounted for 10.8%, and intravenous drug abuse for 0.3%. In the 56 pediatric AIDS cases reported, transmission through contaminated blood accounted for 67.9%, sexual contact for 5.4%, and perinatal transmission for 19.6%. The disease appears to be spreading from the large cities to peripheral and rural areas, and to be spreading faster among heterosexuals than among homosexual and bisexual males. Projections based on continued exponential doubling at the 1983-1986 rate suggest the cumulative AIDS case total could exceed 75,000 by the end of 1991. More conservative estimates based on an observed lengthening of the doubling time predict as many as 260,000 cases by the end of 1994.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[Campaigns against AIDS in Mexico: the sounds of silence or a bridge over troubled waters?].

This paper analyzes the mass media campaigns developed by the Mexican Council for AIDS Control and Prevention (CONASIDA) from 1987 to 1994. This paper presents the lessons learned, a discussion of obstacles and mistakes, and the different evaluation methods which have been used in CONASIDA'S mass media communication strategies and their results. Knowing the opinion of some clue informants was considered relevant--taking into account that evaluations were made by and at CONASIDA--and seven in-depth interviews were conducted among intellectuals, non-governmental organizations (NGO) leaders and public opinion leaders. The importance of society's involvement in AIDS prevention is stated, and two examples of mass media campaigns developed by civil groups are commented. A section about the importance of research as a requisite to produce preventive messages is included, along with some examples. Finally, some conclusions are presented, useful to us, as well as others, in developing new educational campaigns.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[AIDS and human rights].

AIDS and human rights are closely related issues. This paper describes the relationship between AIDS and human rights, the impact and consequences of discrimination and the importance of the defense of human rights as a cornerstone strategy in AIDS prevention. Some general ethical aspects are addressed and two dilemmas which have been raised by the epidemic are discussed: the apparent conflict between individual and community rights and the reactions of intolerance and repression from those who claim that only through coercive strategies will the epidemic be brought under control. Specific problems in Mexico are described based on data collected at CONASIDA's Human Rights Department between 1992 and 1994. Finally some conclusions are stated emphasizing that, in the AIDS epidemic, the defense of human rights is the cornerstone of any public health strategy.

Acquired Immunodeficiency Syndrome↗