Search PubMed⌕ Search

Biomedical subjects

E Romero

Publications and source records attributed to E Romero.

At least 19 recordsLinked to original sources
PubMed1995

HIV type 1 intraperitoneal infection of rabbits permits early detection of serum antibodies to Gag, Pol, and Env proteins, neutralizing antibodies, and proviral DNA from peripheral blood mononuclear cells.

The aim of this study is the development of an animal model useful for studying HIV-1 pathogenesis, candidate vaccines, and antiviral drugs. Aseptic thioglycolate peritonitis was induced in six rabbits. After 4 days, four rabbits were infected with 1 ml of HIV-1 stock containing 100 times the MID50. Blood samples were collected every 2 weeks for 8 months. Serum antibodies were tested by ELISA, using as antigen the recombinant protein p24; synthetic peptides of highly conserved regions of p31, gp41, and gp120; and a synthetic peptide of gp120 at the V3 loop region of HIV-1 strains IIIB and MN. Furthermore, neutralizing antibodies were tested by a microscale neutralization assay. Proviral DNA was detected by PCR, and virus isolation was performed by a cocultivation technique using primary rabbit peripheral blood mononuclear cells (PBMCs). All infected rabbits produced antibodies to HIV-1 proteins within 2 weeks and up to 8 months after virus infection. Serum antibodies were directed against the Env (gp120 and gp41), Gag (p24), and Pol (p31) proteins and against two synthetic peptides whose sequence corresponds to gp120 at the V3 loop region of HIV-1 strains IIIB and MN. Neutralizing antibodies were also detected in the sera of infected animals. Proviral DNA was detected in PBMCs by PCR within 4 weeks and up to 8 months after HIV-1 infection. HIV-1 was also isolated from PBMCs of infected animals at 30, 60, and 120 days after infection. Results obtained indicate that HIV-1 intraperitoneal infection of the rabbit permits the early detection of serum antibodies to Gag, Pol, and Env proteins, neutralizing antibodies, and proviral DNA sequences from PBMCs.

Animals↗
PubMed1995

Extended-spectrum beta-lactamases conferring resistance to monobactams and oxyimino-cephalosporins in clinical isolates of Serratia marcescens.

We studied antibiotic resistance patterns and extended-spectrum beta-lactamases (ES beta Ls) production in Serratia marcescens strains isolated in our hospital during 1993. We examined 210 S. marcescens isolates. Of these, 172 were obtained from 49 patients admitted to an intensive care ward; 157 out of 172 were obtained from February to October and presented the same pattern of antibiotic resistance, including monobactams and oxyimino-cephalosporins. The remaining 15 out of 172 isolates (obtained from September to December) were susceptible to all drugs tested, with the exception of first generation cephalosporins. Thirty-eight additional isolates were recovered, during the same period, from 28 patients admitted to wards other than the intensive care unit; also these strains showed the high susceptibility pattern reported above. Epidemic strains of S. marcescens produced three different types of beta-lactamase with pI 5.4, 5.5, and 8.4. In contrast, non-epidemic strains produced only one type of beta-lactamase with pI 8.4. Conjugation experiments showed that the beta-lactamases having a pI of 5.4 and 5.5 (but not the one with pI 8.4) were plasmid-mediated. Since the beta-lactamase with pI 5.5 was capable of hydrolyzing monobactams and oxyimino-cephalosporins it was classified as ES beta L. Electrophoretic analysis showed that plasmids obtained from multiresistant strains were of about 54 kb; these plasmids appeared also to code for aminoglycoside resistance. Our data indicate that the plasmid-mediated production of ES beta Ls may contribute to the epidemic spread of Serratia marcescens in high-risk wards.

Aztreonam↗
PubMed1994

Extended-spectrum beta-lactamases from Klebsiella pneumoniae strains isolated at an Italian hospital.

Eighteen strains of Klebsiella pneumoniae recently isolated from hospitalized patients were resistant or moderately resistant to oxyimino-cephalosporins (ceftazidime and/or cefotaxime), aztreonam, cefoxitin and all but one were susceptible to imipenem. Analysis of enzymes produced by these clinical isolates revealed a wide pattern of extended-spectrum beta-lactamases. All isolates produced one or more beta-lactamases that were characterized preliminarily by their isoelectric point. Strains isolated early were from patients in the Intensive Care Unit and produced an ES beta-lactamase with an apparent pI of 7.6, whereas the later isolates were from surgical and medical wards of the same hospital and produced ES beta-lactamases with apparent pI of 8.2 and 8.4, respectively. This suggests the emergence of SHV-5 and MIR-1 beta-lactamases in our hospital. Agarose gel electrophoresis of plasmid DNA revealed the presence of a similar plasmid of approximate size 60 Kb in all isolates.

Conjugation, Genetic↗
PubMed1994

Outbreak of extended-spectrum beta-lactamase producing Serratia marcescens in an intensive care unit.

Serratia marcescens has recently been identified as an important etiological agent in nosocomial infections, and is considered to be an opportunistic pathogen agent in immunosuppressed patients undergoing long periods of intensive care. Research carried out in 1991 and 1992 showed that it was of epidemiological relevance in only 1-2% of clinical isolates at the Ospedale di Circolo, Varese, Italy. However, between 7 February and 11 October 1993, the incidence of cases attributable to S. marcescens had increased to 5%; 157 strains of Serratia marcescens were isolated from clinical specimens of 43 patients admitted to an intensive care unit; these strains, characterized by epidemic spread, showed the same pattern of multiresistance to antibiotics including monobactams and oxyimino-cephalosporins. During the same period 23 isolates were also recovered from 18 patients admitted to wards other than the intensive care unit; these strains, characterized by a wide range of antibiotic susceptibility, were also sensitive to beta-lactam antibiotics with the exception of first generation cephalosporins. The production of extended-spectrum beta-lactamases (ES beta Ls) and their genetic determinism were studied. All the epidemic strains of S. marcescens resistant to ceftazidime, cefotaxime, ceftriaxone and aztreonam produced three different beta-lactamases with pI 5.4, 5.5 and 8.4 respectively. In contrast, non-epidemic strains produced only a beta-lactamase with pI 8.4. The beta-lactamase with pI 5.5 was plasmid-mediated, hydrolizing ceftazidime and aztreonam, showing it to be an ES beta L; while the beta-lactamase with pI 5.4, although plasmid-mediated, did not hydrolize monobactams or oxyimino-cephalosporins.(ABSTRACT TRUNCATED AT 250 WORDS)

Cross Infection↗
PubMed1992

Comparative effects of dopaminergic agonists on cardiovascular, renal, and renin-angiotensin systems in hypertensive patients.

The role of dopaminergic receptors on renal function has been extensively studied. Recently dopaminergic receptor has been classified in two subtypes D1 and D2, which seem to have different modulatory function. However, the role of dopaminergic receptors on cardiovascular function and more specifically the potential role of dopaminergic agonists as antihypertensive agents has not yet been clarified. Nine outpatients with mild and moderate hypertension were studied in the Cardiology Service of Vargas Hospital with a D1 agonist, piribedil, at 50-100 mg/day, orally, for 8 weeks, and with a D2 agonist, bromocriptine, at 2.5 - 5 mg/day, orally, for an another 8 weeks by using a placebo comparative crossover design. Piribedil reduced blood pressure with a modest increase in heart rate, plasma renin activity, and of plasma aldosterone, and an important increment of renal function. Bromocriptine reduced blood pressure with a decrease in heart rate and plasma aldosterone without altering renal function. There was no orthostatic hypotension with either agent. The authors conclude that activation of dopaminergic D1 receptor induces a vasodilatory and antihypertensive effect with a reflex increase in sympathetic tone, whereas activation of dopaminergic D2 receptor induces a decrease in sympathetic tone, probably due to a decrease in norepinephrine release at adrenergic endings. The potential effect of these compounds as antihypertensive agents is of great interest because blood pressure reduction can be induced by a new mechanism, i.e. activation of dopaminergic receptors which results in a decrease of the renin angiotensin system or a vasodilatory action.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗
PubMed1992

Double-blind placebo-controlled trial of terazosin effect on blood pressure and urinary output of dopamine in hypertensive patients.

In a parallel, double-blind study, 12 untreated hypertensive patients received terazosin (2-4 mg/day for 4 weeks), and 12 received placebo during the same period. Systolic and diastolic blood pressure decreased significantly in the terazosin group, from 150 +/- 5.0 mmHg systolic and 99.6 +/- 2.0 diastolic before treatment, to 134.0 +/- 7.0 systolic and 85.6 +/- 3.0 mmHg diastolic at week 4 of treatment. No significant blood pressure changes occurred in the placebo group. Blood pressure decrease showed a positive correlation (r = .62 and r = .52 for systolic and diastolic blood pressure, respectively) with the patient's age (P less than .05). Total plasma cholesterol decreased 18% in the terazosin group (P less than .05) and 9% in the placebo group (P greater than .05). Urinary dopamine excretion decreased significantly from 692.8 +/- 180.0 to 330.5 +/- 52.0 micrograms/24 hours in the terazosin group (P less than .05) and showed a nonsignificant increase in the placebo group. Compared with 22 age- and sex-matched healthy volunteers, urinary dopamine excretion in the hypertensive group before treatment was not statistically different (779.3 +/- 83.1 micrograms/24 hours). Dopamine excretion was higher in untreated hypertensive men and in male healthy volunteers compared with women. The decrease of urinary dopamine excretion observed under terazosin treatment could be due to a decrease of kidney dopamine synthesis or release induced by blood pressure reduction, or secondarily to the blockade of kidney alpha 1-receptors, modulating dopamine excretion. No significant changes were observed in urinary excretion of noradrenaline and adrenaline.

Adrenergic alpha-Antagonists↗
PubMed1992

[CD10(CALLA)-negative acute lymphoblastic leukemia. A group with a bad prognosis].

The results of 188 patients with acute lymphoblastic leukemia, studied between 1985 and 1990, showed that 8 cases were CD10 negative, Dr, and CD19 positive. These findings indicate cell dedifferentiation and poor prognosis. The patients age ranged from 2 to 30 years, with a mean of 11 years. The male/female ratio was 5/3. Lymph node enlargement and splenomegaly were found in the 8 patients. With the exception of one patient in whom leucopenia was present, the white cell counts were always higher than 30,000/dl. The karyotype was studied in four cases, and all of them were hyperdiploid. This is the first report in Venezuela of cases with acute lymphoblastic leukemia - CD 10 negative.

Adolescent↗
PubMed1992

Mice infection with HIV-1: a new mouse model for HIV-1 in vivo research.

In mice experimentally infected with 1 x 10(5) UI/mouse of HTLV-IIIB IgM antibodies were detected 10-12 days after the infection, reaching peak values two weeks later; the IgM seratiter progressively decreased thereafter and was negative at ten-eleven weeks. HIV p24 antigen was detected ten-fifteen days after infection and reached peak values five-six weeks later. Antigenemia subsequently decreased and showed an oscillating course with a progressive decrease which persisted throughout the observation period. Two weeks after infection we detected IgG antibodies to the major core protein p24; reactivity to gp41 was observed as early as reactivity to p24 and persisted throughout observation period. The IgG antibodies to all HIV epitopes peaked two-three weeks after infection; the time course showed a decrease after ten weeks, progressively decreasing thereafter. After sixty-five weeks of infection the IgG seratiter value was lower but remained positive. Viruses indistinguishable from HIV were isolated from the peripheral blood mononuclear cells of infected mice 30, 60, 180 days after infection. These seroimmunological and virological data confirm that the immunocompetent mouse may serve as a low-cost reproducible model for HIV-1 in vivo research.

Animals↗
PubMed1990

Social and medical problems in children of heroin-addicted parents. A study of 75 patients.

Between January 1985 and December 1987, seventy-five children of intravenous heroin-addicted parents (one or both) were studied. Their ages ranged from 4 days to 14 years. All patients had suffered from several pediatric diseases. Three major types of problems were found among the children studied: infectious diseases, nutritional diseases, and parental neglect and/or disinterest. The most common diagnoses at discharge were gastroenteritis (24%), pneumonia (21%), malnutrition (17%), upper airway infectious diseases (13%), septicemia (12%), child abuse (4%), acquired immunodeficiency syndrome (3%), and other infectious diseases (24%). Their parents reported hepatitis B virus infection, acquired immunodeficiency syndrome (AIDS), and alcoholism. The unemployment rate among the fathers was 37%. Sixteen percent of mothers were prostitutes. There was an imprisonment record of 19% for mothers and fathers combined. A multidisciplinary approach for this group of children would make prevention possible and care less expensive.

Adolescent↗
PubMed1990

Aggressive keratoacanthoma of the eyelid: "malignant" keratoacanthoma or squamous cell carcinoma?

We report an aggressive keratoacanthoma of the upper eyelid that recurred at the site of a previously excised keratoacanthoma. The diagnosis was confirmed by biopsy. Because the surgery required would be extensive, medical therapy was tried first. The tumor was treated with intralesional injections of 5-fluorouracil and radiotherapy. Despite this therapy, the orbital computed tomogram showed tumor extension into the orbit, and an orbital exenteration was performed. Histopathology of the excised tumor was consistent with squamous cell carcinoma. We discuss the topic of malignant transformation of the keratoacanthoma.

Carcinoma, Squamous Cell↗
PubMed1990

Alterations in prolactin secretion during the 1st postnatal month following perinatal dopaminergic blockade with haloperidol.

This research was intended to study the effects of perinatal haloperidol administration on the postnatal secretion of prolactin (PRL) with the aim of investigating the existence of a 'critical period' during which the lack of dopamine influence could cause long-term alterations in the secretion of this hormone. A first group of animals, composed of pregnant rats, was injected daily with haloperidol (1 mg/kg) from day 16 of gestation to delivery. A second group of newborn rats received the same dose from days 2 to 6 after birth. Pituitary and serum PRL were measured weekly by radioimmunoassay during the 1st postnatal month in pups from the injected mothers, in postnatally injected rats, and in controls. The results showed a significant increase in the pituitary amounts of PRL that was more intense after the prenatal treatment, especially in the females. In serum, the prenatal treatment induced PRL levels higher than in the controls, whereas the postnatally injected group exhibited a V-shaped response which has been described as characteristic of neuroleptic withdrawal. These data confirm the existence of a 'critical period' during which perinatal administration of haloperidol alters the postnatal PRL production and secretion patterns. The persistence of high PRL contents in pituitary may reflect an alteration in the hormone synthesis and/or an increase in the rate of somatomammotrophes that differentiate into lactotrophes after suppression of dopamine influence. The high PRL levels in serum indicate a failure in the control of PRL release, perhaps after damaging the tuberoinfundibular neurons as a consequence of the high prolactinemia induced by the treatment.

Animals↗
PubMed1990

Effects of propolis flavonoids on virus infectivity and replication.

The effect of five propolis flavonoids on the infectivity and replication of some herpesvirus, adenovirus, coronavirus and rotavirus strains has been studied. Experiments were performed in vitro in cell cultures using the viral plaque reduction technique. The cytotoxicity of flavonoids, including chrysine, kaempferol, acacetin, galangin and quercetin, was evaluated on uninfected monolayers to determine their effect on cell growth and viability. Chrysine and kaempferol caused a concentration-dependent reduction of intracellular replication of herpes-virus strains when monolayers were infected and subsequently cultured in a drug-containing medium. However, virus infectivity was not significantly affected. Acacetin and galangin had no effect on either the infectivity or replication of any of the viruses studied. Quercetin reduced infectivity and intracellular replication, but only at the highest concentrations tested.

Animals↗
PubMed1990

Kinetics of p24 antigenemia, IgM, IgG antibodies to p24 and p41 and Ig virus isolation in rabbits experimentally infected with HIV-1.

In rabbits experimentally infected with 1.10(5) u.i./ml HIV, IgM antibodies were detected 10-15 days after infection, reaching peak value two weeks later and remaining stable for two weeks long. Then a the IgM serotiters progressively decreased and were negative at ten weeks. HIV p24 antigen was detected ten-fifteen days after infection, reaching peak value five-six weeks later. Antigenemia subsequently decreased and reached a second peak after nine weeks. In our experimental conditions, the antigenemia persisted throughout the observation period. The IgG antibody titer reached a maximum two weeks after infection; the time course showed a decrease after ten weeks, followed by progressively decreasing fluctuating course. After twenty four weeks of infection the serotiter values though lower were always positive. Three-four weeks after infection we detected IgG antibodies to the major core protein p24. Reactivity of IgG antibodies to gp41 was observed earlier than reactivity to p24; these antibodies were detected over six months after infection. Viruses indistinguishable from HIV were isolated from the peripheral blood mononuclear cells of infected rabbits 30, 60 and 180 days after infection. These data further confirm that the rabbit may serve as an economical and reproducible model for HIV infection in which vaccines and antiviral agents could be tested.

Animals↗
PubMed1990

Emergence of cross-resistance to imipenem and other beta-lactam antibiotics in Pseudomonas aeruginosa during therapy.

The emergence of resistance to imipenem and other beta-lactams by Pseudomonas aeruginosa was investigated with two pairs of isolates. Two of these isolates were susceptible to imipenem and other beta-lactam antibiotics, such as moxalactam, ceftriaxone and cefotaxime, while the other two had developed resistance to those antibiotics during imipenem therapy. So far imipenem-resistant isolates have not demonstrated cross-resistance to other beta-lactam agents. We examined in these clinical isolates the possible mechanisms of resistance due to permeability modifications, either in outer membrane proteins (porins) or to LPS (lipopolysaccharides) complex. Particularly we analysed possible modification of physico-chemical properties of outer membrane proteins, such as changes in their hydrophobicity and electrical charge. beta-lactamase production was also studied. Results showed that resistance to imipenem may be related to loss or modifications in hydrophobicity of an outer membrane protein of about 46 Kdal; other modifications concerned hydrophobicity of the porin OMP F and, in one strain, the LPS complex appears to be responsible for resistance to other beta-lactam antibiotics together in combination with the production of beta-lactamases.

Anti-Bacterial Agents↗
PubMed1990

Trichogenic trichoblastoma. An unusual neoplasm of hair germ.

Tumors of hair germ are a very rare group of primary cutaneous neoplasms that have been divided into two groups: epithelial and mesenchymal. Epithelial neoplasms of hair germ are further subdivided into those that are purely epithelial (trichoblastomas) and into epithelial neoplasms with mesenchymal components that may cause inductive changes toward the earliest phase of hair follicle differentiation (trichoblastic fibroma) or a more advanced and complete hair follicle formation (trichogenic trichoblastoma). We herein report an ulcerated trichogenic trichoblastoma whose epithelial and mesenchymal components recapitulated the formation of numerous primitive dermal papillae of the hair bulb because there were numerous strands of small polygonal epithelial cells that delimited areas of a dense and abundantly cellular connective tissue in a hair papilla-like pattern.

Adult↗
PubMed1989

Modification of norfloxacin inhibition of DNA gyrase induced by a 28 KDal DNA binding protein.

We have previously studied a clinical isolate of Providencia stuartii which showed high levels of resistance to 4-quinolones, aminoglycoside and beta-lactam antibiotics (Landini et al., 1987). DNA gyrase from this isolate was inhibited for 50% of activity at a concentration of 15 microM of norfloxacin, which is about 5-fold higher compared to the 50% inhibitory concentration for a standard DNA gyrase. It has been described that 4-quinolone inhibition of DNA gyrase is caused by their binding to DNA and by the distortion induced in DNA tertiary structure, and that affinity binding of 4-quinolones is different for DNAs in different structures. In order to detect whether the interaction between pAT 153 and a protein able to modify DNA tertiary structure could affect norfloxacin inhibitory concentrations for DNA gyrase we purified from the clinical isolate of Providencia stuartii a DNA binding protein of about 28 KDal which induces changes in supercoiling degree of DNA. Assays of DNA gyrase activity were performed on the complex pAT 153-DNA binding protein-norfloxacin. Results showed an increase from 15 microM to 20 microM of 50% norfloxacin inhibitory concentration for DNA gyrase when pAT 153 was complexed with the 28 KDal protein.

DNA Helicases↗
PubMed1989

Detection of IgG anti-HIV antibodies in mice experimentally infected with HIV-1.

In the present work we report our preliminary data demonstrating the susceptibility of mouse to HIV infection. IgG antibodies were found in mice intraperitoneally inoculated with H9/HTLV-IIIB infected cells. Infected mice showed a humoral response and the antibodies detection includes specific immunoglobulin directed against the major gene product of HIV. Two weeks after infection with HIV infected cells we detected in mice IgG antibodies to p24, and the reactivity to gp41 was observed as early as reactivity to p24 and persisted throughout observation period. The persistence of specific antibody response to HIV after one year seems to demonstrate the possibility of the use of the mouse as animal model for HIV in vivo experiments. Studies concerning the degree and kinetic of HIV infection in mouse are in progress in our laboratory.

Acquired Immunodeficiency Syndrome↗