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Biomedical subjects

J Arellano

Publications and source records attributed to J Arellano.

At least 19 recordsLinked to original sources
PubMed2001

High frequency of association of rheumatic/autoimmune diseases and untreated male hypogonadism with severe testicular dysfunction.

Our goal in the present work was to determine whether male patients with untreated hypogonadism have an increased risk of developing rheumatic/autoimmune disease (RAD), and, if so, whether there is a relation to the type of hypogonadism. We carried out neuroendocrine, genetic, and rheumatologic investigations in 13 such patients and 10 healthy male 46,XY normogonadic control subjects. Age and body mass index were similar in the two groups. Nine of the 13 patients had hypergonadotropic hypogonadism (five of whom had Klinefelter's syndrome [karyotype 47,XXY]) and 4 of the 13 had hypogonadotropic hypogonadism (46,XY). Of these last four, two had Kallmann's syndrome and two had idiopathic cryptorchidism. Eight (61%) of the 13 patients studied had RADs unrelated to the etiology of their hypogonadism. Of these, four had ankylosing spondylitis and histocompatibility B27 antigen, two had systemic lupus erythematosus (in one case associated with antiphospholipids), one had juvenile rheumatoid arthritis, and one had juvenile dermatomyositis. In comparison with the low frequencies of RADs in the general population (about 0.83%, including systemic lupus erythematosus, 0.03%; dermatomyositis, 0.04%; juvenile rheumatoid arthritis, 0.03%; ankylosing spondylitis, 0.01%; rheumatoid arthritis, 0.62%; and other RAD, 0.1%), there were surprisingly high frequencies of such disorders in this small group of patients with untreated hypogonadism (P < 0.001) and very low serum testosterone levels (P = 0.0005). The presence of RADs in these patients was independent of the etiology of their hypogonadism and was associated with marked gonadal failure with very low testosterone levels.

Adolescent↗
PubMed2001

Barrel pattern formation requires serotonin uptake by thalamocortical afferents, and not vesicular monoamine release.

Thalamocortical neurons innervating the barrel cortex in neonatal rodents transiently store serotonin (5-HT) in synaptic vesicles by expressing the plasma membrane serotonin transporter (5-HTT) and the vesicular monoamine transporter (VMAT2). 5-HTT knock-out (ko) mice reveal a nearly complete absence of 5-HT in the cerebral cortex by immunohistochemistry, and of barrels, both at P7 and adulthood. Quantitative electron microscopy reveals that 5-HTT ko affects neither the density of synapses nor the length of synaptic contacts in layer IV. VMAT2 ko mice, completely lacking activity-dependent vesicular release of monoamines including 5-HT, also show a complete lack of 5-HT in the cortex but display largely normal barrel fields, despite sometimes markedly reduced postnatal growth. Transient 5-HTT expression is thus required for barrel pattern formation, whereas activity-dependent vesicular 5-HT release is not.

Aging↗
PubMed2001

Transgenic tobacco plants that overexpress alfalfa NADH-glutamate synthase have higher carbon and nitrogen content.

This work reports the characterization of transgenic tobacco (Nicotiana tabacum L.) plants that constitutively overexpress NADH-GOGAT. Three independent transformants, designated GOS10, GOS13 and GOS19 (for GOGAT sense), with stable integration of the chimeric alfalfa NADH-GOGAT gene fused to the CaMV 35S promoter were studied. The transgene was stably integrated and inherited by the progeny. In these GOS lines, the expression of NADH-GOGAT mRNA and protein was detected at low levels in roots and leaves, while the expression of the host tobacco NADH-GOGAT gene was nearly undetectable. The roots of GOS lines showed an elevated (15-40%) enzyme activity as compared to control plants. When GOS plants were grown under greenhouse conditions and fed with either nitrate or ammonium as the sole nitrogen source, they showed higher total carbon and nitrogen content in shoots and increased shoot dry weight when plants were entering into the flowering stage, as compared to control plants. The observed phenotype of GOS plants was interpreted as reflecting a higher capacity to assimilate nitrogen due to a higher NADH-GOGAT activity.

Amino Acid Oxidoreductases↗
PubMed2001

Two-dimensional echo Doppler findings in juvenile and adult onset ankylosing spondylitis with long-term disease.

The authors' objective was to determine by 2-dimensional echo Doppler (2DECHO) the cardiac abnormalities in juvenile onset ankylosing spondylitis (JOAS) and adult onset ankylosing spondylitis (AOAS) in male patients with long-term disease. Twenty patients with JOAS, 31 with AOAS, and 20 healthy controls of the same age and gender without cardiopulmonary symptoms were studied. Using 2DECHO, the heart dimensions were determined according to American Society of Echocardiography guidelines. The left ventricle ejection fraction (LVEF) was calculated by Teichholz's formula. Cardiomyopathy was established when 2DECHO had diminished LVEF. Statistics used were the Student t and Fisher test, chi2, and ANOVA. Ninety percent of JOAS and 51% of AOAS patients were B27+ (p=0.005). The disease duration was 19.3 +/- 8.8 years in JOAS and 14.8 +/- 12.8 years in AOAS (p=NS). Age at the time of the study was 30.7 +/- 9.9 years in JOAS vs 40.3 +/- 12.7 in AOAS (p=0.003), and vs 40.2 +/- 17 years in controls (p=NS). There was a higher frequency of cardiomyopathy in AOAS (32.2%) than in JOAS (25%) and the controls (0%) (p=0.01). Patients with JOAS had a higher mitral valve gradient (25%) than AOAS patients (19%, p=NS) and controls (0%, p=0.04). Abnormal aortic ring reflectance was shown in 19% of AOAS vs 0% abnormalities in JOAS and controls (p=0.01). The aortic root diameter was increased in 58% of AOAS, 30% of JOAS, and 0% of controls (p=0.001). The frequency of 2DECHO abnormalities was increased in cardiopulmonary asymptomatic spondylitis patients. Despite the high frequency of B27+, JOAS had a lower frequency of aortic abnormalities than AOAS. Mitral valve gradient was found in JOAS and in AOAS that could contribute to a decreased ejection fraction and to left ventricular dysfunction.

Adolescent↗
PubMed1999

HLA characterization in adult asymptomatic cyst passers of Entamoeba histolytica/E. dispar.

The present work aimed at studying the possible association of HLA antigens with Entamoeba histolytica/E. dispar asymptomatic infection in a Mexican mestizo population. A case-control design was selected for evaluation of the role of genetic markers in parasite infection. For this purpose the HLA-A, HLA-B, and HLA-DR profiles of a population of asymptomatic E. histolytica/E. dispar adult cyst passers (cases) and a corresponding nonparasitized adult group (controls) followed for 12 months were identified. Entamoeba species were identified through zymodeme patterns and/or amplification of species-specific DNA sequences. A healthy, nonparasitized group of individuals was included as a control. Our results show that apparently, no specific HLA marker is associated with the asymptomatic cyst passers' condition. These findings have to be added to previous results in which, in contrast to a demonstrated association between HLA-DR3 and amebic liver abscess in Mexican mestizo adults and infants, no significant association with amebic rectocolitis was found.

Animals↗
PubMed1999

Histomorphological and histochemical characteristics of the intestine of the Senegal sole, Solea senegalensis.

The Senegal sole, Solea senegalensis has been exploited extensively in aquaculture from different countries; at present an intensive production of larvae and adults is being achieved with some nutritional problems. Since this species displays very different life styles and feeding habits at different stages of its life history (larvae, metamorphosis, adults), and because digestive mucins are implicated in different physiological processes including: increase of digestive efficiency, promotion of macromolecules-absorption, buffering of intestinal fluid, prevention of proteolytic damage to the epithelium and defence against bacteria, etc., we studied the histomorphological aspects, as well as the histochemical distribution of carbohydrates, (PAS, Alcian Blue), proteins (Bromophenol Blue), lipids (Oil Red O, Black Sudan B) and glycoproteins (Horseradish peroxidase-conjugated lectins) in the intestinal epithelium of adult Solea senegalensis specimens. Our data are compared with those obtained in larvae and adults of this and other fish species. Primary and secondary folds, microvilli of the intestinal enterocytes, as well as mucous or goblet cells were observed with a scanning electron microscope. Enterocytes and mucocytes of the intestine of adult Solea senegalensis were characterized by a rich supply of sugar and oligosaccharides. Carbohydrates (glycogen and mucins), proteins and lipids were present in cytoplasm and microvilli--brush border--of the enterocytes, which contain GalNAc, GlcNAc, Man, Glc and sialic acid-N-acetyl-D-galactosamine glycoconjugates. Intestinal mucous cells were strongly or weakly stained with Alcian Blue (pH 2.5 and 1). PAS reactivity was intense in numerous goblet cells, but some cells were PAS unreactive or weakly stained. Some goblet cells were positive for Bromophenol Blue but numerous cells were unstained; thus many proteins and possibly lipids may be conjugated with sugars. A similar reactivity to WGA and to neuraminidase-WGA was identified in some intestinal goblet, which were Con A unreactive, indicating the absence of Man and/or Glc and NANA glycoconjugates. GalNAc residues were only scarcely present in glycoproteins of some goblet cells.

Animals↗
PubMed1998

Yeast transcript elongation factor (TFIIS), structure and function. II: RNA polymerase binding, transcript cleavage, and read-through.

The transcriptionally active fragment of the yeast RNA polymerase II transcription elongation factor, TFIIS, comprises a three-helix bundle and a zinc ribbon motif joined by a linker region. We have probed the function of this fragment of TFIIS using structure-guided mutagenesis. The helix bundle domain binds RNA polymerase II with the same affinity as does the full-length TFIIS, and this interaction is mediated by a basic patch on the outer face of the third helix. TFIIS mutants that were unable to bind RNA polymerase II were inactive for transcription activity, confirming the central role of polymerase binding in the TFIIS mechanism of action. The linker and zinc ribbon regions play roles in promoting cleavage of the nascent transcript and read-through past the block to elongation. Mutation of three aromatic residues in the zinc ribbon domain (Phe269, Phe296, and Phe308) impaired both transcript cleavage and read-through. Mutations introduced in the linker region between residues 240 and 245 and between 250 and 255 also severely impaired both transcript cleavage and read-through activities. Our analysis suggests that the linker region of TFIIS probably adopts a critical structure in the context of the elongation complex.

Models, Molecular↗
PubMed1998

Histochemical study of lymphocystis disease in skin of gilthead seabream, Sparus aurata L.

A battery of horseradish peroxidase-conjugated lectins (Con A, WGA and DBA), as well as conventional histochemical techniques (PAS, saponification, Alcian Blue pH 0.1, 1, 2.5, chlorhydric hydrolisis, sialidase, Bromophenol blue, Tioglycollate reduction and Ferric-ferricyanide-FeIII) were used to study the content and distribution of carbohydrates, proteins and glycoconjugate sugar residues on the skin and on the lymphocystis-infected cells of gilthead seabream, Sparus aurata. Variable amounts of glycoproteins containing sialic acid, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, mannose and/or glucose residues were observed in the cuticle and mucous cells of the corporal skin, tails and fins. Germinative and epithelial cells of the epidermis contained glycogen, proteins, carboxylated groups, as well as glycoproteins with mannose and/or glucose and N-acetyl-D-galactosamine residues. Hyaline capsule of the mature lymphocystis-infected cells was strongly stained with PAS, Alcian Blue (pH 0.5 and 2.5) and weakly positive with Alcian Blue (pH 1). Con A reacted with the granular cytoplasm, specially around hyaline capsule, and with the basophilic intracytoplasmic inclusions developed in mature lymphocystis-infected cells of Sparus aurata skin. These sugar residues (mannose and/or glucose), as well as N-acetyl-D-glucosamine and/or sialic acid and N-acetyl-D-galactosamine were not detected in the hyaline capsule of the lymphocystis disease.

Animals↗
PubMed1998

Histochemical study of skin and gills of Senegal sole, Solea senegalensis larvae and adults.

A battery of horseradish peroxidase-conjugated lectins (Con A, WGA and DBA), as well as conventional histochemical techniques (PAS, saponification, Alcian Blue pH 0.1, 1, 2.5, chlorhydric hydrolisis, neuraminidase, Bromophenol blue, Tioglycollate reduction and Ferric-ferricyanide-FeIII) were used to study the content and distribution of carbohydrates, proteins and glycoconjugate sugar residues on the skin and gills of Senegal sole, Solea senegalensis larvae and adults: During larval development of Solea senegalensis (from hatching until day 45 posthatching), epidermal sacciform, as well as branchial and epidermal chloride cells were unreactive with all cytochemical tests performed in this paper. Mucous or goblet cells of the corporal skin and gills containing strongly sulphated acid glycoproteins were evident on days 15-20 of larval development, as well as in epidermal and branchial mucous cells of adult specimens, which also contained GlcNAc and/or sialic acid. In adult specimen, the proteic content was higher in branchial mucous cells than in epidermal cells. In larvae, variable amounts of glycoproteins containing sialic acid, GlcNAc, GalNAc, Man and/or Glc residues were observed in epithelial cells and/or cuticle. GlcNAc and/or sialic acid sugar residues were only weakly detected in glycoproteins of some epidermal and branchial mucous cells of larvae by day 45, because from hatching until metamorphosis, lectin reactions (WGA, Con A and DBA) were negative in mucous cells.

Animals↗
PubMed1996

Increased frequency of HLA-DR3 and complotype SCO1 in Mexican mestizo children with amoebic abscess of the liver.

The increase of HLA-DR3 and complotype SCO1 previously found in Mexican mestizo adults with E. histolytica amoebic abscess of the liver, was also found in Mexican mestizo children of either sex with the same disease, when compared to the healthy control population (adults and/or children) of the same ethnic and socioeconomic background. This HLA and complotype pattern was not found in Mexican Mestizo patients with amoebic rectocolitis. No linkage disequilibrium was found between these and the other MHC determinants tested in this survey. Thus, HLA-DR3 and SCO1 may constitute primary, independent risk factors, not for any kind of amoebic tissue invasion (i.e. amoebic rectocolitis), but specifically for amoebic liver abscess, irrespective of age or sex. The possibility of linkage disequilibrium with other factors (i.e. the TNF family) within or close to the MHC that were not tested in this study, is discussed. Children with amoebic liver abscess revealed a significant increase in HLA-DR5, and the absence of HLA-DR6 when compared to adults with amoebic liver abscess, suggesting that at least in this ethnic group these class II HLA traits may contribute to some of the peculiarities of pediatric amoebic liver abscess as opposed to the adult version of this disease. HLA-DR3, SCO1, but also HLA-DR5 and HLA-DR6 have all been associated with certain forms of immune-dysfunction, and may thus contribute to some of the clinical and immunological features of this parasitic disease.

Adolescent↗
PubMed1996

Histological and histochemical characteristics of the lymphocystis disease in gilthead seabream, Sparus aurata L. from the south-atlantic coast of Spain.

Lymphocystis disease of the gilthead seabream, Sparus aurata from the south Atlantic coasts of Spain was studied using various cytochemical methods for nucleic acids, proteins, carbohydrates and lipids. In lymphocystis infected cells, cytoplasm and nucleoli contained RNA. DNA was restricted to the periphery of the nucleus and within the intracytoplasmatic inclusions. During the development of infected cells, proteins rich in different aminoacids were observed in the granular cytoplasm, nucleus/nucleoli, intracytoplasm inclusions and hyaline capsule. Some glycogen was observed in the cytoplasm of these cells. The intracytoplasm inclusions and the hyaline capsule also contain hydrophilic lipids, being noticeable the presence of proteins containing S-S groups. Sulphated sialoglycoproteins and glycolipids and/or phospholipids were also components of the hyaline capsule.

Animals↗
PubMed1995

Antigen induced eosinophilia protects gerbils (Meriones unguiculatus) against experimental amebic abscess of the liver.

While the normal human eosinophil is destroyed in vitro by virulent Entamoeba histolytica, notwithstanding the presence of antibodies and complement, activated eosinophils promptly destroy the parasite even though succumbing in the process as well. To study the possible in vivo participation of eosinophils in invasive amebiasis, we compared the induction of experimental amebic abscess of the liver (EAAL) in gerbils (Meriones unguiculatus) previously made eosinophilic (532 +/- 80 eosinophils/mm3) through Toxocara canis antigen injection and normal control gerbils (101 +/- 15 eosinophils/mm3). Shortly (6 and 24 h) after intraportal injection of 10(5) virulent E. histolytica, the ratio of gerbils with EAAL, as well as the number and size of the abscesses was comparable in eosinophilic and control gerbils. At 96 h post-inoculation, the ratio of animals with EAAL was still the same in both groups, yet number and size of abscesses were significantly (p < 0.05) smaller in eosinophilic gerbils. The actuarial EAAL survival curve up to 45 days post-amebic inoculation was significantly (p < 0.05) shifted to the right in eosinophilic gerbils. No significant changes in IL-5 levels were recorded throughout these experiments. The results suggest that antigen-induced eosinophilia may exert a protective effect against EAAL in gerbils. It is speculated that a less overwhelming EAAL strategy--more akin to human amebic abscesses--may reveal this protective effect more clearly.

Animals↗
PubMed1993

Entamoeba histolytica: antibody response to recent and past invasive events.

Sero-epidemiological data from endemic amoebiasis areas are difficult to evaluate because the serology of individuals affected by an active process of Entamoeba histolytica tissue invasion is, at present, almost impossible to distinguish from that of individuals who have had an invasive event in the past. The present study compares serum antigenic recognition frequencies among three groups of individuals with different infective conditions: amoebic liver abscess patients; asymptomatic cyst passers; and individuals who have had amoebic liver abscess from one to three years before the study. Control groups consisted of Mexican and Canadian healthy adults. Western blots of E. histolytica membrane extract antigen were reacted with sera from the studied individuals, recognition frequency values were calculated and immunoplots of frequency differences were constructed. The results obtained suggest that the identification and purification of antigenic fractions, which are frequently recognized by sera of amoebic liver abscess patients (136, 132, 93, 70 and 62 kDa), or preferentially associated with past invasive events (144, 140 and 49 kDa), or related to the E. histolytica cyst passer condition (62 and 136 kDa), are important improvements in the use of serology for diagnosis and epidemiological studies in endemic areas of amoebiasis.

Adult↗
PubMed1992

The destruction of virulent Entamoeba histolytica by activated human eosinophils.

Unlike normal (i.e., non-activated) human eosinophils that are unable to destroy virulent Entamoeba histolytica even in the presence of antibodies and complement, activated eosinophils effectively destroy the parasite in vitro without the help of opsonins, yet increase this capacity with their assistance. Many activated eosinophils succumb in the process as well, probably victims of toxic products released by dying amoebae. Human activated eosinophils thus behave more like activated macrophages than like neutrophil polymorphonuclear leucocytes that are notoriously incompetent in dealing with virulent amoebae. As a regular constituent of early inflammatory reactions, and notwithstanding the absence of blood and tissue eosinophilia in invasive amoebiasis, the activated eosinophil may play a role in the defence against E. histolytica.

Adult↗
PubMed1992

The killing of Entamoeba histolytica by activated human eosinophils.

Unlike normal, opsonin aided human eosinophils, fMLP-activated human eosinophils are capable of destroying virulent E. histolytica. Opsonins are not required for this action, although they enhance the effect. Some activated eosinophils succumb in the action as well, probably victims of toxic products released by dying amebas. Activated eosinophils thus appear to resemble activated macrophages in their dealing with this parasite.

Adult↗