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Biomedical subjects

S Moreno

Publications and source records attributed to S Moreno.

At least 163 records · Page 9Linked to original sources
PubMed1995

[Fever evolution after treatment in patients with tuberculosis and HIV infection].

OBJECTIVES: To compare the fever course after starting therapy in patients diagnosed of active tuberculosis with and without HIV infection and evaluate the usefulness of empiric antituberculous therapy in diagnosing the disease. METHODS: Review of clinical records from all patients meeting the following criteria for three years: recovery of Mycobacterium tuberculosis from any clinical sample, knowledge of serological status to HIV, initial therapy of tuberculosis, absence of ther causes of fever identified, and not being treated with drugs which potentially could interfere with the course of fever during their hospital stay. RESULTS: At admission HIV-positive patients with tuberculosis were afebrile in a significantly lower proportion than HIV-negative patients (17% vs. 54%, respectively; p < 0.001). After initiating antituberculous therapy, the median time to fever resolution was similar in both HIV-positive and HIV-negative patients (6 and 4 days, respectively). After two weeks of therapy, 25% of HIV-positive patients and 23% HIV-negative patients still had fever. No factor was identified which could predict the delay in resolution of fever. CONCLUSIONS: The course of fever was similar in both HIV-positive and HIV-negative patients after initiating antituberculous therapy. This empirical therapy may be useful in diagnosing tuberculosis, as fever resolved in the first two weeks of therapy in most patients.

AIDS-Related Opportunistic Infections↗
PubMed1995

[Tuberculosis presenting as diffuse pulmonary infiltrates in AIDS patients: diagnostic performance of clinical samples].

BACKGROUND: In patients with human immunodeficiency virus (HIV) infection, tuberculosis is frequently presented with diffuse pulmonary infiltrates which are indistinguishable from those caused by other respiratory pathogens. It is therefore useful to know the diagnostic performance of different clinical samples. METHODS: We have retrospectively analyzed the clinical histories of 56 patients seen over a 3-year period. All the patients had HIV infection, Mycobacterium tuberculosis isolated in at least one clinical sample and presented with diffuse bilateral infiltrates in thorax radiography. The results of all the clinical samples submitted to the microbiology laboratory. RESULTS: The highest performance in both stainings and cultures were obtained from the biopsy (or aspirate) of adenopathies (93 and 100%, respectively), sputum (57 and 88%) and urine (31 and 64%). A lower than expected sensitivity was obtained in the fibrobronchoscopy samples (bronchoalveolar lavage and transbronchial biopsy). The staining had low sensitivity for predicting positive cultures in all the samples except in the adenopathies. Visualization of granulomas in transbronchial biopsies and bone marrow was more sensitive for diagnosis than the demonstration of resistant acid-alcohol bacilli in the same samples. Globally, rapid diagnosis was obtained in 43 patients (76%). The remaining 13 (24%) patients were not diagnosed until the culture results had been received despite the adequate use of diagnostic procedures. CONCLUSIONS: These findings support the use of empiric treatment when tuberculosis is suspected despite initial negativity of the microbiologic and pathologic examinations following the discarding of other potential causes.

AIDS-Related Opportunistic Infections↗
PubMed1994

Low molecular weight protein-tyrosine phosphatases are highly conserved between fission yeast and man.

Cdc25 protein phosphatase dephosphorylates tyrosine 15 of Cdc2, thereby activating Cdc2/cyclin B kinase, which then brings about mitosis. A fission yeast (Schizosaccharomyces pombe) cDNA expression library was screened for clones that rescue cdc25-22. In addition to the cdc25+ and pyp3+ protein-tyrosine phosphatase genes, a third gene was discovered. This gene, named stp1+ (small tyrosine phosphatase), encodes a approximately 17.5-kDa protein that is approximately 42% identical to members of an unusual class of small (approximately 18 kDa) cytosolic phosphatases previously known to exist only in mammalian species. The biological functions of these proteins are unknown, but they have vigorous protein-tyrosine phosphatase activity in vitro and have a sequence motif, Cys-X5-Arg, that is present at the active sites of all known types of protein-tyrosine phosphatases. Sequence homology between S. pombe Stp1 and its mammalian homologs is particularly high in the active site region of the proteins. Rescue of cdc25-22 by overproduction of Stp1 protein is probably due to an ability of Stp1 to dephosphorylate tyrosine 15 of Cdc2. Disruption of stp1+ causes no obvious phenotype. The fact that Stp1 homologs are highly conserved between yeast and man suggests that they have important functions.

Amino Acid Sequence↗
PubMed1994

Regulation of protein kinase A subunits during germination of Mucor rouxii sporangiospores.

Levels of protein kinase A (PKA) subunits and of cAMP have been measured during aerobic germination of the sporangiospores of the dimorphic fungus Mucor rouxii; further, the holoenzyme and its catalytic (C) and regulatory (R) subunits have been visualized through sucrose gradient centrifugation. Sporangiospores contain around 0.06 microM of a dimeric holoenzyme species of 5.5 S and a sixfold excess of a free R subunit of 2.7 S. Both these species are proposed to be derived by proteolysis from the native forms. Enzymic activity at this stage is highly inhibited, as demonstrated with permeabilized cells. Immediately upon germination, and after a transient increase in cAMP concentration from 10 microM to 90 microM, C-subunit levels fall to 30%. After the onset of germination, the specific activity and concentration of both the 5.5 S holoenzyme species and the 2.7 S species of free R subunit decrease in parallel to the increase in total protein and volume. Net synthesis of C and R subunits to form a native holoenzyme species of 8.8 S is apparent 4 h onwards after germination. A significant increase in cellular concentration is observed at 6 h. At 7 h of growth, when germ-tube emission is complete, the holoenzyme concentration is around 0.23 microM; there is almost no free R subunit and the intracellular concentration of cAMP is around 3 microM. A role for PKA during germination and morphogenesis is discussed.

Cell Membrane Permeability↗
PubMed1994

Regulation of progression through the G1 phase of the cell cycle by the rum1+ gene.

The rum1+ gene is identified as a new regulator of G1 progression in fission yeast. It influences three aspects of G1 regulation: determination of the length of G1, dependence of S phase upon completion of mitosis, and restraint of mitosis until G1 is finished. We propose that it has a central role in regulating the G1 phase of the cell cycle.

Amino Acid Sequence↗
PubMed1994

Regulation of the cell cycle timing of Start in fission yeast by the rum1+ gene.

We have identified the rum1+ gene as a new regulator of the G1-phase of the fission yeast cell cycle. rum1+ determines the cell cycle timing of Start, by maintaining cells in a pre-Start state until they have attained a minimal critical mass. Cells lacking rum1+ are unable to arrest in pre-Start G1 in response to nitrogen starvation and are subsequently sterile. In addition, rum1+ prevents entry into mitosis from pre-Start G1, as shown by the fact that cdc10 mutants in the absence of rum1+ undergo lethal mitosis without entering S-phase.

Cell Cycle↗
PubMed1994

Molecular genetics of the glutamine synthetases in Rhizobium species.

Soil bacteria of the genus Rhizobium and Bradyrhizobium establish symbiotic interactions with leguminous plants that result in the formation of specialized structures, the nodules, in which the bacteria differentiate into bacteroids and fix nitrogen. Rhizobial glutamine synthetase (GS) activity is very low in the nodule. The ammonia produced by the bacteroids is exported to the plant cell, where it is assimilated by the GS from the plant, whereas in the free-living state, Rhizobium and Bradyrhizobium species assimilate ammonia for growth. Another characteristic of these species is that they possess two glutamine synthetase isozymes, known as GSI and GSII. A third glutamine synthetase isozyme, called GSIII, has been found in R. meliloti and R. etli.

Amino Acid Sequence↗
PubMed1994

Immobilization of coypus (Myocastor coypus) with ketamine hydrochloride and xylazine hydrochloride.

A combination of 100 mg/ml of ketamine hydrochloride (Ket) and 20 mg/ml of xylazine hydrochloride (Xyl) was used to immobilize coypus (Myocastor coypus). Eight mature coypus (four males and four females) were injected intramuscularly with doses ranging from 2.33 to 6.25 mg/kg of KET and 0.25 to 0.86 mg/kg of Xyl. The mean (+/- SE) time for induction, arousal, and recovery were 7.3 +/- 2 min, 23.5 +/- 0.3 min and 46 +/- 2.5 min, respectively. The mean +/- SE doses injected were 4.07 +/- 0.52 mg/kg Ket (range, 2.33 to 6.25 mg/kg) and 0.5 +/- 0.08 mg/kg Xyl (range, 0.25 to 0.86 mg/kg). No adverse responses were observed in any of the animals treated.

Animals↗
PubMed1994

Effects of Di-(2-ethylhexyl)phthalate on peroxisomes of liver, kidney and brain of lactating rats and their pups.

Di-(2-ethylhexyl)phthalate administered to adult lactating rats, from delivery to weaning, induces modifications of the peroxisomal enzymatic pattern in the liver, kidney and brain of both dams and pups. These modifications are age- and organ-dependent. Biochemical analysis shows that: 1) catalase specific activity is two-fold increased in the liver of both adult and newborn animals, in the kidney of newborns and in the brain of adults. 2)D-amino acid oxidase doubles in all newborn organs and in adult brain; it increases, although to a lesser extent, also in adult kidney, while it is half-reduced in adult liver. 3) Dihydroxyacetone phosphate acyl transferase only doubles in newborn liver, remaining fairly unchanged in all the other tested tissues. 4) Palmitoyl-CoA oxidase is greatly induced in the liver of both dams and litters, doubled in the kidneys and slightly increased or not at all in the brain of pups and mothers, respectively. The effect of the drug on enzyme activities is reversible, with different time courses depending on the considered enzyme and organ. Western blottings confirm the biochemical data. Electron microscopy shows proliferated peroxisomes in the liver and kidney of treated animals but not in the brain, where high catalase-like immunoreactivity is observed in the cytosol of neurons. Taken together, our data demonstrate that the response of peroxisomal enzymes to DEHP treatment is age- as well as tissue-dependent and specific for each enzyme studied.

Acyltransferases↗
PubMed1994

Impact of an educational program for the prevention of colonization of intravascular catheters.

OBJECTIVE: To evaluate the efficacy of an educational program for the prevention of catheter colonization. DESIGN: Two cross-sectional studies were carried out in a 500-bed randomly selected area of the hospital, separated by an educational program on the care of intravenous lines based on the Centers for Disease Control and Prevention (CDC) recommendations for the control of catheter-related infections. SETTING: A 2,100-bed urban general hospital affiliated with the University of Madrid (Spain). METHODS: Characteristics of patients and catheters and appropriateness of catheter care were evaluated. Cultures were taken from the point of insertion of the vascular catheter, the hubs, and infusion fluids. When catheter-associated infection was suspected, the distal end of the catheter was sent for culture and two blood cultures were taken. We compared the clinical and microbiological data before and after carrying out an educational program based on CDC recommendations for the control of catheter-related infections. RESULTS: Characteristics of patients and catheters did not differ between the two cross-sectional studies. Compared with baseline data, after the educational program we observed a reduction of inappropriate catheter care, from 83% to 38% (45% difference, 95% confidence interval [CI95], 55% to 35%, P < 0.0000), and a reduction in the rate of skin colonization, from 34% to 18% (16% difference, CI95, 26% to 5%, P < 0.001). The frequency of phlebitis (15% versus 14%), hub colonizations (12% versus 11%), catheter colonizations (2% versus 1%), and catheter-related bacteremias (0% versus 0%) remained unchanged between the two cross-sectional studies. CONCLUSIONS: Our educational program improved catheter care and reduced significantly the proportion of skin colonization around the insertion point. However, the educational program did not modify the proportion of hub colonization; because hub colonization has been demonstrated to be a source of line sepsis, our data suggest the need for a specific program directed to the maintenance of catheter hubs.

Adult↗
PubMed1993

Risk for developing tuberculosis among anergic patients infected with HIV.

OBJECTIVE: To assess the risk for development of tuberculosis among anergic patients infected with the human immunodeficiency virus (HIV). DESIGN: Retrospective cohort study. SETTING: Tertiary referral center. PATIENTS: All HIV-infected patients who had a baseline positive protein purified derivative test (PPD) and delayed-type hypersensitivity skin tests. MEASUREMENTS: Development of active tuberculosis. RESULTS: Of 374 patients, 108 (29%) had positive results of PPD tests, 154 (41%) had negative results of PPD tests but no skin anergy, and 112 (30%) were anergic. Conversion of the PPD to positive was observed in 10 of 67 (15%) patients with previously negative results of PPD tests and no anergy and in 3 of 36 (8%) anergic patients who were retested during the follow-up period (mean, 26 months). The risk for active tuberculosis to develop in patients not receiving isoniazid chemoprophylaxis was similar in patients with a positive PPD test result (10.4 cases per 100 person-years) and in anergic patients (12.4 cases per 100 person-years) and higher in both groups than in nonanergic patients with a negative PPD test result (5.4 cases per 100 person-years). Tuberculosis was more frequent among intravenous drug abusers with no previous isoniazid treatment (63 of 290, 22%) than among homosexual men (0 of 29) or patients in other HIV transmission categories (0 of 31). Preventive therapy with isoniazid reduced tuberculosis development (4% as compared with 31%; P = 0.008). Among 15 anergic patients who had CD4 counts measured within 3 months of tuberculosis development, only 1 (7%) had more than 500 CD4 cells/mm3. CONCLUSIONS: Anergic HIV-infected patients are at high risk for development of tuberculosis. Anergic HIV-infected patients, in addition to HIV-infected patients with positive results of PPD tests, should be offered preventive therapy if they live in areas with a high prevalence of tuberculosis, at least when the CD4 count decreases to less than 500 CD4 cells/mm3.

Adult↗
PubMed1993

Mycobacterium tuberculosis bacteremia in patients with and without human immunodeficiency virus infection.

PURPOSE: To determine the incidence of Mycobacterium tuberculosis bacteremia in a general hospital and to describe the clinical characteristics, therapy, and outcome of patients with bacteremic tuberculosis. PATIENTS AND METHODS: Clinical charts of all patients in whom M tuberculosis was isolated from blood cultures during a 5-year period were reviewed. Mycobacterium tuberculosis was detected by means of a nonradiometric blood culture system. RESULTS: Of 285 patients with culture-proved tuberculosis in whom blood cultures were obtained, 50 (14%) had M tuberculosis bacteremia. Of 42 patients analyzed, 34 (81%) were infected with human immunodeficiency virus (HIV) and eight (19%) were not infected with HIV. Blood was the only or the first positive specimen in 14 patients (33%). Most HIV-infected patients (79%) were intravenous drug users, and 40 (88%) had clinical and/or radiologic evidence of involvement of one or more organs. Lungs were affected in 71% of the patients. In-hospital mortality was 18% in HIV-infected patients with mycobacteremia. Among eight non-HIV-infected patients, four had an underlying disease, and none was immunosuppressed. Disseminated disease was diagnosed in three patients. Two patients died as a consequence of tuberculosis in this group. CONCLUSIONS: Mycobacterium tuberculosis bacteremia is common in HIV-infected patients and is possible in nonimmunosuppressed subjects. Blood cultures are helpful in making the diagnosis of tuberculosis and can help establish a diagnosis of disseminated infection.

AIDS-Related Opportunistic Infections↗
PubMed1993

Unusual neurofilament composition in cerebellar unipolar brush neurons.

During antibody screening on sections of rat cerebellum, we noticed a group of small neurons which exhibited unusual staining properties. They were robustly immunopositive for the high molecular weight neurofilament protein, moderately immunostained with antibodies to the low molecular weight neurofilament protein and alpha-internexin, but only faintly immunoreactive (in PAP sections) or essentially immunonegative (in immunofluorescent sections) with all members of a panel of antibodies directed against the middle molecular weight neurofilament protein. Since neurons generally react equally well with phosphate-independent, (antibodies to) low, middle and high molecular weight neurofilament protein, we conclude that middle molecular weight neurofilament protein is present in these cells in an unusually low relative amount. These cells are found in the granular layer and appear concentrated in the flocculus, ventral paraflocculus, and vermis, particularly in the ventral uvula and nodulus (lobules IXd and X). Previous studies performed by Hockfield defined a population of neurons of similar appearance and distribution using the monoclonal antibody Rat-302, which recognized an uncharacterized 160 kDa protein. We show here that the cells described by Hockfield are identical to those we have found and furthermore that the Rat-302 antibody specifically recognizes the dephosphorylated form of the lysine-serine-proline repeated sequences of high molecular weight neurofilament protein. These cells were studied by pre-embedding immunoelectron microscopy. The nucleus is deeply indented and shows little condensed chromatin. The cytoplasm contains scattered microtubules and a larger number of neurofilaments than expected in a small cell. There are numerous large dense core vesicles, an unusual organelle consisting of ringlet subunits, and relatively little granular endoplasmic reticulum. A thin axon and a single stout dendritic trunk emanate from the perikaryon. Although the cell body and the dendritic shaft may form either complex contacts with mossy fibres (resembling those previously termed en marron synapses) or simple symmetric synapses with small boutons containing pleomorphic vesicles, most of the synaptic relations are established on the shafts of brush-like branchlets that form at the tip of the dendrite and enter one or two glomeruli. Each branchlet forms an extraordinarily extensive asymmetric synapse with the mossy fibre rosette and the subsynaptic region shows a microfibrillar web connected to the postsynaptic density. In addition to other organelles, the branchlets contain numerous mitochondria and large dense core vesicles. Short, non-synaptic appendages with few cytoplasmic organelles emanated from the cell body, dendritic shaft and branchlets.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholinesterase↗
PubMed1993

Purification of peroxisomal fraction from rat brain.

A purification procedure to obtain peroxisomes (microperoxisomes) from the brain of suckling rats is reported. A P2 fraction, (crude light mitochondria) frozen and thawed seven times, was subfractionated yielding a P4 fraction, 4-fold enriched in catalase activity with respect to the cytoplasmic extract S1. The P4 fraction was used for further purification of peroxisomes by isopicnic centrifugation on Nycodenz gradient (1.10-1.20 g/ml). When the cerebellum was not included in the starting material, the equilibrium density of peroxisomes was 1.152-1.162 g/ml. In this case the overall yield of catalase in the most enriched fraction was 7% and its relative specific activity more than 50. When the cerebellum was included in the total homogenate, the equilibrium density shifted towards higher values (1.177 g/ml) and in this case the catalase relative specific activity in the peroxisomal enriched fraction was extremely high (> 100). The biochemical results, together with the electron microscope examination of the purified fractions, demonstrate that our procedure allows the best purification of brain peroxisomes so far obtained. The different equilibrium densities of peroxisomes observed in the two sets of experiments are interpreted in terms of size heterogeneity of these organelles in different brain portions and cell types.

Animals↗
PubMed1993

Isobutylmethylxanthine and other classical cyclic nucleotide phosphodiesterase inhibitors affect cAMP-dependent protein kinase activity.

The effect of 17 inhibitors of cyclic nucleotide phosphodiesterases (PDEs) was assayed on cAMP binding activity of Mucor rouxii protein kinase A (PKA), on PKA activity in the absence of cAMP and on free catalytic subunit (C) activity. Isobutylmethylxanthine (IBMX), SQ 20,009 and cilostamide, at 0.2 mM, behaved as partial agonists of cAMP since they inhibited binding of 0.15 microM [3H]cAMP to the regulatory subunit (R), stimulated slightly PKA activity in the absence of cAMP and did not modify C activity. Amrinone at 0.2 mM inhibited C activity competitively towards ATP. These four compounds displayed the same effects when assayed on eukaryotic protein kinase A types I (PKI) and II (PKII). The combined effect of IBMX and cAMP was analysed on Mucor PKA. Under dissociating conditions (+ 0.5 M NaCl) IBMX antagonized activation by low concentrations of cAMP, while in the absence of NaCl, IBMX potentiated the stimulating activity of cAMP.

1-Methyl-3-isobutylxanthine↗
PubMed1993

Meningitis due to Aeromonas species: case report and review.

In recent years, Aeromonas species has been reported to cause extraintestinal infections with a growing frequency. Meningitis due to Aeromonas species is, however, a rare entity. We report a case of aeromonas meningitis in a 54-year-old man with a history of chronic alcoholic liver disease who, after an episode of gastroenteritis, developed an acute clinical picture characteristic of meningitis with septic shock and ecthyma gangrenosum. Aeromonas veronii (biogroup sobria) was isolated from cultures of blood as well as from cultures of stool, peritoneal fluid, skin lesion, and CSF specimens (obtained by lumbar puncture). Our review of seven additional cases of aeromonas meningitis in the world literature revealed that this condition is generally secondary to metastatic dissemination from primary bacteremia. Aeromonas meningitis, which may or may not be preceded by gastroenteritis, presents clinically as bacterial meningitis, although the presence of skin lesions may increase suspicion of the diagnosis. Third-generation cephalosporins are probably the therapy of choice for patients with aeromonas meningitis.

Aeromonas↗
PubMed1992

Tuberculous meningitis in patients infected with the human immunodeficiency virus.

BACKGROUND AND METHODS: Tuberculosis is a frequent complication of human immunodeficiency virus (HIV) infection. We describe the clinical manifestations and outcomes of tuberculous meningitis in patients with HIV infection, and compare them with those in non-HIV-infected patients. We reviewed the records from 1985 through 1990 at two large referral hospitals in Madrid for patients who had Mycobacterium tuberculosis isolated from cerebrospinal fluid. RESULTS: Of 2205 patients with tuberculosis, 455 (21 percent) also had HIV infection, of whom 45 had M. tuberculosis isolated from the cerebrospinal fluid. Of the 37 HIV-infected patients with tuberculous meningitis for whom records were available, 24 (65 percent) had clinical or radiologic evidence of extrameningeal tuberculosis at the time of admission. In 18 of 26 patients (69 percent), a CT scan of the head was abnormal. In most patients, analysis of cerebrospinal fluid showed pleocytosis (median white-cell count, 0.234 x 10(9) per liter) and hypoglycorrhachia (median glucose level, 1.3 mmol per liter), but in 43 percent (15 of 35), the level of protein in cerebrospinal fluid was normal. In four patients with HIV infection, tuberculosis was only discovered after their deaths. Of the 33 patients who received antituberculous treatment, 7 died (in-hospital mortality, 21 percent). Illness lasting more than 14 days before admission and a CD4+ cell count of less than 0.2 x 10(9) per liter (200 per cubic millimeter) were associated with a poor prognosis. Comparison with tuberculous meningitis in patients without HIV infection showed that the presentation, clinical manifestations, cerebrospinal fluid findings, and mortality were generally similar in the two groups. However, of the 1750 patients without HIV infection, only 2 percent (38 patients) had tuberculous meningitis, as compared with 10 percent of the HIV-infected patients (P less than 0.001). CONCLUSIONS: HIV-infected patients with tuberculosis are at increased risk for meningitis, but infection with HIV does not appear to change the clinical manifestations or the outcome of tuberculous meningitis.

Acquired Immunodeficiency Syndrome↗