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Biomedical subjects

J Cobo

Publications and source records attributed to J Cobo.

At least 19 recordsLinked to original sources
PubMed2006

Abnormal development of pacinian corpuscles in double trkB;trkC knockout mice.

Pacinian corpuscles depend on either Aalpha or Abeta nerve fibers of the large- and intermediate-sized sensory neurons for the development and maintenance of the structural integrity. These neurons express TrkB and TrkC, two members of the family of signal transducing neurotrophin receptors, and mice lacking TrkB and TrkC lost specific neurons and the sensory corpuscles connected to them. The impact of single or double targeted mutations in trkB and trkC genes in the development of Pacinian corpuscles was investigated in 25-day-old mice using immunohistochemistry and ultrastructural techniques. Single mutations on trkB or trkC genes were without effect on the structure and S100 protein expression, and caused a slight reduction in the number of corpuscles. In mice carrying a double mutation on trkB;trkC genes most of the corpuscles were normal with a reduction of 17% in trkB-/-;trkC+/- mice, and 8% in trkB +/-;trkC -/- mice. Furthermore, a subset of the remaining Pacinian corpuscles (23% in trkB-/-;trkC+/- mice; 3% in trkB+/-;trkC-/- mice) were hypoplasic or atrophic. Present results strongly suggest that the development of a subset of murine Pacinian corpuscles is regulated by the Trk-neurotrophin system, especially TrkB, acting both at neuronal and/or peripheral level. The precise function of each member of this complex in the corpuscular morphogenesis remains to be elucidated, though.

Animals↗
PubMed2006

[Pure alexia secondary to progressive multifocal leukoencephalopathy as first manifestation of HIV infection].

INTRODUCTION: Pure alexia, or alexia without agraphia, is usually caused by disconnection between the gyrus angularis and visual areas of both hemispheres. Cerebrovascular disease is the most frequent cause of this syndrome. CLINICAL CASE: We report the first case of a patient with pure alexia secondary to progressive multifocal leukoencephalopathy (PML) as the first manifestation of Human Immunodeficiency Virus (HIV) infection. Polymerase chain reaction in cerebrospinal fluid was positive for JC virus. Despite favorable immunological and virological response to highly active antiretroviral therapy, neurological symptoms and demyelinating lesions progressed during the first months, and right homonyous hemianopsia, acalculia, and color anomia were noted. In magnetic resonance imaging (MRI) demyelinating lesions involved white matter of both occipital lobes, with left predominance, forceps major and splenium of the corpus callosum, together with white matter of the left temporal lobe and both hippocampal regions. During the following months, coinciding cidofovir treatment, the patient had partial clinical improvement, but neurological deficits persisted. The size of MRI lesions significantly improved. CONCLUSIONS: PML is frequently the first manifestation of AIDS (acquired immunodeficiency syndrome). It should be considered as a possible diagnosis of pure alexia.

Alexia, Pure↗
PubMed2005

Bcl-2 immunoreactivity in human cutaneous Meissner and Pacinian corpuscles.

The occurrence and distribution of Bcl-2, a protein involved in the death-life cell pathways, was investigated in the peripheral sensory nervous system of healthy adult humans, including lumbar dorsal root ganglia, nerve trunks and glabrous skin (to analyze sensory corpuscles) using Western blot and immunohistochemistry. The antibody used labelled a protein of 26 kDa of estimated molecular weight corresponding with Bcl-2. Immunohistochemistry showed that only a neuronal population in dorsal root ganglia, some axons in peripheral nerves and the axon supplying Meissner and Pacinian corpuscles contained Bcl-2, whereas peripheral glial cells (i.e. satellite glial cells, Schwann cell, and lamellar cells of sensory corpuscles) did not. These results suggest that in normal conditions, Bcl-2 is only present in some neuronal, but not glial, elements of the sensory peripheral nervous system. The functional significance, if any, of these results remains to be determined.

Adult↗
PubMed2005

Onset of antidepressant action: a pharmacological question?

OBJECTIVE: This study was conducted to analyse the onset of action of antidepressants in naturalistic conditions. METHOD: Multicenter, prospective, open-label, non-comparative naturalistic study among 582 depressed outpatients treated with mirtazapine. The patients were assessed at screening, and after 1, 2 and 4 weeks by the 17-item Hamilton depression rating scale (17-HAM-D) and clinical global impression (CGI). Onset of action was measured by traditional analyses based on the time to a persistent reduction of more than 50% from baseline on the 17-HAM-D. Patients were grouped into four groups: very fast responders, fast responders, traditional responders and partial or non-responders. The non-parametric Kruskall-Wallis test was used to assess differences between the groups and logistic regression to predict response after 1 week of treatment. RESULTS: 16% of patients had a very fast response, 42.1% a fast response, 26.5% a traditional response and 15.5% a partial or non-response. There were no significant differences between these groups with regard to dose of mirtazapine or sociodemographic characteristics. The baseline total 17-HAM-D was lower in the faster groups than in the slower groups. The evolution of 17-HAM-D items was similar in each responder group. CONCLUSION: Time to response varied from early faster response to late slower response. The evolution of 17-HAM-D for each type of response was similar, but occurred at a different time in each group.

Adolescent↗
PubMed2004

Adenosine deaminase activity in cerebrospinal fluid of HIV-infected patients: limited value for diagnosis of tuberculous meningitis.

Adenosine deaminase activity (ADA) determination in cerebrospinal fluid (CSF) is considered a specific test for the diagnosis of tuberculous meningitis. In order to study the variability of this marker in patients with different neurological disorders associated with HIV infection, and its utility for the diagnosis of tuberculous meningitis in these patients, the ADA levels in 417 CSF samples from HIV-infected patients with neurological symptoms were reviewed. HIV infection, HIV-associated neurological disorders, and progressive multifocal leukoencephalopathy were not associated with elevated ADA in CSF. Among patients with meningitis, receiver operating characteristic curve analysis gave an optimal ADA cut-off point of 8.5 IU/l for the diagnosis of tuberculous meningitis, with 57% sensitivity, 87% specificity, and an area under the curve of 0.747 (similar to that for CSF glucose concentration). False-positive results were found in patients with neurological CMV disease and cryptococcal, lymphomatous, and probable candidal meningitis. The results of this study indicate that ADA determination in CSF has limited utility for the diagnosis of tuberculous meningitis in HIV-infected patients.

AIDS-Related Opportunistic Infections↗
PubMed2004

Neurotrophin receptors in taste buds of adult zebrafish (Danio rerio).

TrkB plays crucial roles in the development and maintenance of taste buds in mammals. In this study we investigated the presence and cell localization of Trks (TrkA, TrkB and TrkC) in taste buds of the zebrafish (Danio rerio) using Western blot and immunohistochemistry. Proteins of 140 and 145 kDa, identified as full-length TrkA and TrkB, were detected. Conversely, the anti-TrkC antibody recognized a protein lower than expected (100 kDa). In agreement with these results the sensory cells of taste buds, displayed TrkA- and TrkB-like, but not TrkC-like, immunoreactivity. TrkA and TrkB co-existed in the same taste buds, but remains to be clarified whether or not they are co-expressed in the same cells. Present results demonstrate that as for mammals neurotrophins might play a role in sensory cells of the teleostean taste buds.

Animals↗
PubMed2003

Nocardial infection in patients infected with the human immunodeficiency virus.

During the period 1981-2000, we diagnosed eight cases of HIV-Nocardia co-infection (0.38% of AIDS cases). Six were males, and the mean age was 28.6 years. The most common risk factor for HIV infection was intravenous drug abuse. Most patients were severely immunodepressed at the time of diagnosis (mean CD4+ count, 35 cells/ micro L). The clinical forms of nocardiosis seen were pulmonary infection in three, skin or soft tissue infection in three, disseminated in one, and pulmonary colonization in one. Most patients were given sulfonamides, and a clinical response was observed in six of seven treated patients. However, two patients with pulmonary disease died from progressive infection. Although its incidence is very low among AIDS patients, nocardiosis is associated with high morbidity and mortality among HIV-infected individuals.

Adult↗
PubMed2002

Clinical study of 44 cases of Staphylococcus aureus meningitis.

In order to describe the clinical features and outcome of Staphylococcus aureus meningitis, the charts of 44 cases seen at one teaching hospital during a 20-year period were retrospectively reviewed. Staphylococcus aureus was the fifth most common cause of bacterial meningitis (10.2% of cases). There were 28 (63%) cases of postoperative meningitis and 16 (37%) of spontaneous meningitis. Patients with postoperative meningitis were younger than patients with spontaneous meningitis (mean age, 40.3 vs. 59.3 years; P=0.04) and had a lower frequency of community-acquired infection (32.1% vs. 93.8%; P<0.01), severe underlying diseases (28% vs. 87%; P<0.01) and associated staphylococcal infection (35% vs. 75%; P=0.01). The clinical presentation was similar in both groups, but patients with postoperative meningitis had a lower frequency of altered mental status (39% vs. 75%; P=0.02), meningeal signs (28% vs. 62%; P=0.02), petechial rash (0% vs. 18%; P=0.04), bacteremia (7% vs. 75%; P<0.01), and septic shock (0% vs. 44%; P<0.01). Most patients were treated with cloxacillin or vancomycin, with or without rifampicin, for a mean period of 22.5 days (range, 1-100 days). Overall mortality was 27%, and the mortality rate was higher for cases of spontaneous than postoperative meningitis (50% vs. 14%; P=0.01). Mortality correlated significantly with advanced age, spontaneous meningitis, altered mental status, and the presence of severe underlying diseases, bacteremia, and septic shock.

Anti-Bacterial Agents↗
PubMed2002

Infection with Nocardia species: clinical spectrum of disease and species distribution in Madrid, Spain, 1978-2001.

BACKGROUND: Clinical experience with nocardiosis is very limited in European countries. We describe 34 cases of nocardial infection seen at one Spanish teaching hospital. PATIENTS AND METHODS: A retrospective review of the clinical features and outcome of nocardial infections was conducted during a 24-year period (1978-2001). All cases were confirmed by culture. RESULTS: Predisposing factors included immunosuppression and/or pulmonary disease in 85% of patients; eight cases were related to HIV infection. Most isolates were initially identified as Nocardia asteroides complex (97%). The most common clinical form was pulmonary disease (41%), followed by disseminated (15%), cutaneous (12%), cerebral (9%) and articular disease (3%). A high proportion of patients (20%) had pulmonary colonization. Therapy with sulfonamides, imipenem or amikacin was given to 26 patients and a clinical response was observed in 65%. Overall mortality among patients with nocardial disease was 48% (13/27) but only seven patients (26%) died from nocardiosis. CONCLUSION: Nocardiosis remains a rare opportunistic infection that appears in immunosuppressed patients. HIV infection has become a common predisposing condition. The species distribution and disease spectrum are similar to those described in other European countries. Although most patients develop active disease, pulmonary colonization might not be as rare as has generally been assumed. Treatment with sulfonamides is usually effective and many patients may remain free of nocardial disease for a prolonged period.

Adolescent↗
PubMed2001

4-(4-Chlorophenyl)-3,7,7-trimethyl-1-[2-(4-nitrobenzoyl)ethyl]-4,7,8,9-tetrahydro-1H-pyrazolo[3,4-b]quinolin-5(6H)-one-ethanol (1/1).

Molecules of the title compound, C(28)H(27)ClN(4)O(4).C(2)H(6)O, form a C(6) chain via an N--H...O hydrogen bond along the c axis by the operation of a c-glide plane, with N...O = 2.761 (3) A and N--H...O = 165 degrees. The molecules are further linked by a weak C--H...O interaction, with C.O = 3.344 (4) A and C--H...O = 150 degrees. Pendant hydrogen-bonded ethanol solvent molecules are attached to the chains by O--H...N hydrogen bonds, with O...N = 2.904 (3) A and O--H...N = 175 degrees.

Antiviral Agents↗
PubMed2001

Ethyl 6-amino-2-methoxypyridine-3-carboxylate, interplay of molecular and supramolecular structure.

The title compound, C(9)H(12)N(2)O(3), crystallizes with two molecules in the asymmetric unit. There is extensive hydrogen bonding which results in the formation of a two-dimensional corrugated sheet. This supramolecular structure is determined by the formation of hydrogen-bonded chains resulting from the presence of a 6-amino group and an ethoxycarbonyl group as substituents on a pyridine ring in relative para positions which constitute a pi-electron 'push-pull' system.

Journal Article↗
PubMed2001

Bis[N-(6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxypyrimidin-2-yl)glycyl-glycinato]triaquacalcium: coordination polymer chains linked by hydrogen bonds.

In the title compound, [Ca(C9H11N6O5)2(H2O)3], the Ca atom lies on a twofold rotation axis in C2/c and the three water molecules are all disordered, each over two sites having equal occupancy. The anion acts as a bridging ligand between pairs of Ca sites on the same twofold axis, thus forming a one-dimensional coordination polymer, with the chains lying along the twofold axes. These chains are linked by multiple O-H...O and N-H...O hydrogen bonds into a single three-dimensional framework.

Journal Article↗
PubMed2001

Methyl 4-amino-2,3-dihydro-6-methoxy-1,3-dioxo-1H-pyrrolo[3,4-c]-pyridine-7-carboxylate forms hydrogen-bonded sheets built from R2(2)(8) and R6(6)(42) rings.

In the title compound, C10H9N3O5, which was formed by the reaction of 6-amino-2-methoxy-4(3H)-pyrimidinone with dimethyl acetylenedicarboxylate, the molecules are linked by N-H...O hydrogen bonds [N...O 2.8974 (15) and 3.0300 (15) A, and N-H...O 165 and 174 degrees] into planar sheets built from alternating R2(2)(8) and R6(6)(42) rings.

Journal Article↗
PubMed2001

[N-(6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl)-glycylglycinato]aquapotassium, a three-dimensional coordination polymer.

In the title compound, polymeric potassium N-(6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl)glycylglycinate hydrate, (K(+).C(9)H(11)N(6)O(5)(-).H(2)O)(n), the hexacoordinate K(+) cation is linked to five different anions as well as to the water molecule, with K-O distances in the range 2.617 (2)-2.850 (2) A. Four of the O atoms in each anion coordinate to K centres, one of them acting as a bridging ligand, leading to the formation of nearly square centrosymmetric K(2)O(2) rings. The structure is analysed in terms of (010) metal-ligand sheets linked by [010] chains of fused rings.

Journal Article↗
PubMed2001

Methyl 7-hydroxy-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydropteridine-6-carboxylate-dimethyl sulfoxide (1/1) forms chains containing O-H...O and C-H...O hydrogen bonds and aromatic pi-pi-stacking interactions.

In the title compound, C11H12N4O5-C2H6OS, the molecular components are linked by a short hydrogen bond with dimensions O...O 2.517 (2) A and O-H...O 168 degrees. Paired C-H...O hydrogen bonds [C...O 3.362 (2) and 3.382 (2) A; C-H...O 157 and 140 degrees] generate cyclic centrosymmetric four-component aggregates reinforced by aromatic pi-pi-stacking interactions, and further C-H...O hydrogen bonds [C.O 3.472 (3) and 3.521 (2) A; C-H...O 156 and 157 degrees] link these aggregates into chains.

Crystallography, X-Ray↗
PubMed2001

Predicting tuberculosis among HIV-infected patients admitted to hospital: comparison of a model with clinical judgment of infectious disease specialists.

The aim of this prospective study was to compare a model based on clinical variables with the clinical judgment of infectious disease specialists to identify HIV-infected patients requiring isolation at admission in order to prevent the nosocomial transmission of tuberculosis. Clinical, epidemiological and radiological variables available at admission were recorded for 362 admissions of 274 HIV-infected patients. Using multiple logistic regression analysis, a model to identify patients with tuberculosis was developed based on four clinical variables (node enlargement, constitutional symptoms, intravenous drug use, history of previous correct therapy for tuberculosis) and a positive auramine sputum stain. This model was applied to each of the 362 admissions studied. The decision made by the infectious disease specialist at admission was also recorded. The results indicate that application of the model would have allowed physicians to correctly identify and isolate 24 of 27 patients with tuberculosis, while 5.4 patients without tuberculosis would have been unnecessarily isolated for every patient with tuberculosis. The results for the infectious disease specialists were slightly better, with 26 of 27 patients with tuberculosis being identified and isolated correctly and only 3.2 patients being isolated unnecessarily for every patient with tuberculosis. Thus, a simple model based on clinical variables may be useful in helping physicians identify tuberculosis carriers among HIV-infected patients, but infectious disease specialists are able to identify them more efficiently.

AIDS-Related Opportunistic Infections↗