Search PubMed⌕ Search

Biomedical subjects

J Gomez

Publications and source records attributed to J Gomez.

At least 145 records · Page 8Linked to original sources
PubMed1990

Analysis of the autoagglutination phenomenon, serogroup and hydrophobicity as virulence markers in mesophilic aeromonads isolated from stool cultures.

The autoagglutination phenomenon (AA) was studied in 71 strains of mesophilic aeromonads isolated from stool cultures of patients with acute diarrhea (28 Aeromonas hydrophila, 20 Aeromonas sobria, and 23 Aeromonas caviae). Two phenotypes were considered in the AA+ strains: SP+ (self-pelleting) and PAB+ (precipitation after boiling). Serogrouping of the strains was performed only with the 0:11 serum. Other properties studied were agglutination with acriflavine (Acr) and crystal violet uptake (CVB). Phenotype AA+ was found in 29.5% of the strains; 7% of these AA+ strains exhibited the SP+ PAB+ pattern and 22.5% the SP- PAB+ pattern. The species Aeromonas hydrophila comprised the highest proportion (28.5%), and Aeromonas caviae the lowest (13%). Fifty percent of the PAB+ strains of Aeromonas hydrophila and Aeromonas sobria belonged to serotype 0:11. None of the PAB+ strains of Aeromonas caviae belonged to this serotype. 8.4% of the strains were Acr+ and 23.9% CVB+.

Acute Disease↗
PubMed1990

Microbiological characteristics of Weeksella virosa (formerly CDC group IIf) isolated from the human genitourinary tract.

Weeksella virosa (formerly CDC group IIf) is a nonsaccharolytic, oxidase- and catalase-positive, gram-negative rod which is unable to grow on MacConkey agar. At 48 h of incubation on blood or chocolate agar, the colonies present a characteristic appearance: intensely mucoid, adherent, and cream colored as a result of the production of a nondiffusible yellow pigment. This microorganism has been isolated predominantly from the female genitourinary tract, which indicates the opportunity for sexual transmission. We present the microbiological study of three strains of W. virosa identified in a study of 707 female genital samples, representing an incidence of 0.42%. At the same time, we analyzed the principal biochemical tests used in the identification of this microorganism and the susceptibilities of the organism to the different antimicrobial agents assayed.

Female↗
PubMed1990

Characterization of receptors for platelet-activating factor in guinea pig lung membranes.

Platelet-activating factor (PAF) is a potent contractile agonist in guinea pig peripheral lung strips. Whether PAF acts via specific receptor sites in the lung has not been fully established. To determine if specific receptor sites could be demonstrated in guinea pig peripheral lung tissue, we performed direct radioligand binding studies in tissue homogenates with [3H]C16-PAF (1-O-hexadecyl-sn-glyceryl-3-phosphorylcholine) and the PAF antagonists [3H]WEB 2086 and [3H]RP52770. These studies demonstrated binding sites for [3H]C16-PAF of high affinity (Kd of 2.6 nM from saturation isotherms and 0.9 nM from kinetic experiments) and a mean density of 200 fmol/mg protein. Binding was inhibited to the same degree with unlabeled C16-PAF, WEB 2086, and RP52770, all with pseudo-Hill slopes of unity. [3H]WEB 2086 binding demonstrated a receptor density similar to that of [3H]C16-PAF (226 fmol/mg protein) and was inhibited to the same degree by unlabeled C16-PAF, C18-PAF, WEB 2086, and RP52770. Although antagonist inhibition yielded pseudo-Hill slopes near unity, agonist inhibition slopes were shallow, suggesting two types or states for the PAF receptors. Direct binding studies with [3H]RP52770 revealed a much larger density of binding sites (1,200 fmol/mg protein), and this binding was not inhibited with C16-PAF, C18-PAF, WEB 2086, or lyso-PAF. These results indicate that guinea pig lung has specific binding sites for [3H]C16-PAF, that WEB 2086 is an effective antagonist of C16- and C18-PAF binding at these sites, and that RP52770 binds to the PAF site but, in addition, binds to another site with a much greater density.

Animals↗
PubMed1989

Subjective response during continuous infusion of cocaine.

The relationship between the subjective effects induced by IV cocaine injection(s) and cocaine plasma concentrations is complex and difficult to interpret. We designed a study in which bolus loading doses of cocaine followed by 4-hr placebo infusions were compared with the same bolus loading doses of cocaine followed by 4-hr infusions of cocaine calculated to maintain the peak plasma concentrations produced by the bolus. Seven cocaine-using volunteers were successfully studied using a randomized double-blind design, in which self- and observer-rating scales were used to measure drug effects. After the cocaine bolus loading doses, scores for most subjective measures remained elevated when the bolus was followed by a cocaine infusion. In contrast, the subjective responses returned to baseline when the bolus was followed by a placebo infusion. However, self-estimates of the intensity of the cocaine "rush" were not altered by the presence of active cocaine infusions and returned rapidly to baseline.

Adult↗
PubMed1989

Disruption of auditory function by acute administration of a "room odorizer" containing butyl nitrite in rats.

Butyl nitrite is the predominant and presumed active ingredient in a variety of commercial preparations sold as "room odorizers." These compounds have significant abuse potential, giving the user the sensation of a "rush", which may be related to their intense cardiovascular effects. The pharmacological properties of butyl nitrites are similar to those of amyl nitrite which is also abused for its psychological effects, but whose availability is limited by prescription for treatment of angina. A significant body of literature suggests that the inner ear is vulnerable to acute hypoxic exposure. Since butyl nitrite induces high levels of methemoglobin and also reduces blood pressure due to peripheral vasodilation, we hypothesized that this compound might produce auditory dysfunction. We studied the effect of acute exposure to a butyl nitrite "room odorizer" on 10- and 40-kHz auditory function in rats. A loss in auditory sensitivity was found at both frequencies on the day following administration of the compound. Auditory dysfunction tended to subside over the next several days at 40 kHz, although a significant loss of sensitivity for tones of 10 kHz was observed over a 6-day period after administration of the agent. Methemoglobin levels measured in rats of the same age were elevated significantly 30 and 60 min after butyl nitrite to levels of 30-45%. Methemoglobin levels were found to be normal 18 hr after administration when the first audiometric tests were conducted. The data suggest that auditory function in the middle of the rats' auditory range, 10 kHz, was disrupted for a longer period than was high-frequency (40 kHz) auditory function.

Air Pollutants↗
PubMed1989

Value of sonography in true complete diphallia.

A case of true complete diphallia associated with multiple malformations is presented. Complete radiological evaluation should include sonography of both penes preoperatively to classify the penile duplication correctly.

Abnormalities, Multiple↗
PubMed1989

Use of ceftriaxone in the treatment of bacterial infections in cirrhotic patients.

Sixty-two episodes of bacterial infection were studied in 51 cirrhotic patients. 2 g of ceftriaxone (active ingredient of Rocephin) were given intravenously once daily for 7-10 days. The infections were pneumonia, bacteremia, spontaneous bacterial peritonitis, urinary infection and others. Good responses were seen in 90% of the cases.

Adult↗
PubMed1989

Analysis of the individual allergens of Russian thistle pollen by an enzyme-linked immunoblotting technique.

Russian thistle pollen extract was analyzed by immunoblots of isoelectric focused and SDS-PAGE gels. Twenty distinct protein bands were recognized by human IgE- and IgG-specific antibodies in the immunoblot from the SDS-PAGE gel. Molecular weights of these allergens ranged from 12.2 kD to 85 kD. Seventeen bands were detected on isoelectric focusing immunoblots with pI from 3.95 to 7.70. Allergic subjects had differing individual patterns of protein band recognition. Immunoblot techniques provide detailed evaluations of the response of allergy subjects to components of crude natural allergens.

Allergens↗
PubMed1989

[Echocardiographic diagnosis of a hydatid cyst localized at the intraventricular septum].

A patient with case of an hydatid cyst located in the interventricular septum is presented. The two-dimensional echocardiography clearly visualized the cystic configuration of the disease, demonstrating its great usefulness for detecting this type of cardiac pathology. The patient underwent surgery with extracorporeal circulation. In this article we also discuss the surgical indications of this pathology.

Adult↗
PubMed1989

An evaluation of the results of a drug sample analysis.

An analysis of drug samples received by the National Toxicology Institute at Madrid during the period from September 1985 to May 1987 was undertaken with a view to carrying out an epidemiological assessment of drug abuse. Of 414 street drug samples, 63.5 per cent contained heroin, 12.5 per cent cocaine, 8.5 per cent amphetamine and 15.4 per cent other substances. The concentration of heroin ranged from 21 to 60 per cent in most of the samples (91.8 per cent) that contained it. Similar concentrations of cocaine were found in the samples containing that substance. Adulterants were detected in 78.8 per cent of the samples containing heroin, 59.6 per cent of the samples containing cocaine and 56 per cent of the samples containing amphetamine. The most common adulterants in the samples containing heroin were caffeine (68.4 per cent), phenobarbital (19.7 per cent), methaqualone (13.4 per cent) and procaine (13.4 per cent), while lidocaine was the most common adulterant (52 per cent) in the samples containing cocaine.

Amphetamines↗
PubMed1988

Partial cognitive-dysmnesic seizures as a model for studying psychosis.

Nineteen patients were analyzed who exhibited cognitive-dysmnesic psychic partial seizures and structural damage shown by means of CT scans. It was observed that these seizures originated in the amygdala-hippocampal system, coinciding with the effects found when using electrical stimulation of the brain. An attempt is made to relate these findings to the present biochemical hypotheses of schizophrenia, the kindling effect and the genetico-maturational hypotheses. All these data seem to agree and point in the direction of the possible neurophysiological mechanisms of psychosis and of schizophrenia in particular.

Adolescent↗
PubMed1987

Palinopsia and visual allesthesia.

Two cases of palinopsia are reported. The first patient had palinopsia and visual allesthesia secondary to an occipital calcified cysticercus. Symptoms were more prominent during treatment for his parasitic infection. The second case was a patient with long standing vascular headaches associated for many years with episodes of visual persistence; he had a right occipital lobe infarct; he reported deformation of images, illusion of movement and macropsia in his left homonymous hemianoptic visual field. Different hypotheses for explaining palinopsia have been proposed. An analysis of our cases does not prove or disprove any of the current hypotheses. However, the current hypotheses do not necessarily contradict each other. Implications of the two cases reported are analyzed.

Adult↗
PubMed1987

[Sudden tetraplegia caused by hemorrhage in a central-medullary astrocytoma].

A case is reported of central-medullary cervical astrocytoma, which without any previous history is shown by a sudden pattern of tetraplegia and breathing insufficiency. The myelography suggested the existence of an expansive intramedullary process, carrying out an urgent surgical decompression and evacuating a central-medullary hematoma in relation to a glial benign type. Various aspects of the sudden tetraplegia are discussed.

Adult↗
PubMed1986

Sustained ventricular tachycardia in chronic chagasic myocarditis: electrophysiologic and pharmacologic characteristics.

Sustained ventricular tachycardia (VT) develops in many patients with chronic Chagasic myocarditis. Programmed stimulation was used to study the electrophysiologic characteristics of VT in 15 patients with Chagas' cardiomyopathy. Nine patients were in New York Heart Association functional class I, 5 were in class II and 1 patient was in class III. The average ejection fraction was 56 +/- 7%, which is somewhat better than that reported in patients with VT owing to idiopathic cardiomyopathy. In 11 patients VT could be reproducibly initiated and terminated by programmed stimulation. Intravenous mexilitene prevented induction of VT in 7 of 8 patients; amiodarone did not prevent induction in 3 of 4 patients. Our data indicate that the mechanism of VT is likely to be reentrant in many patients, and therefore VT can be produced by extrastimuli. Electrophysiologic study is therefore useful for establishing the diagnosis of sustained VT and may be useful for guiding initial therapy in selected cases of Chagas' disease.

Adolescent↗
PubMed1986

Diagnosis and management of an atypical case of canine hydrocephalus, using computed tomography, ventriculoperitoneal shunting, and nuclear scintigraphy.

Hydrocephalus was diagnosed in a 4-month-old Staffordshire Terrier with gastrointestinal and neurologic signs and cervical pain, using computed tomography. A ventriculoperitoneal shunt was used to manage the hydrocephalus. Ventriculoperitoneal shunt patency was assessed, using nuclear scintigraphy. Because of expense and potential shunt complications, a ventriculoperitoneal shunt might not always be practical; however, this mode of diagnosis and management was successful.

Animals↗
PubMed1986

Chemotaxis of large granular lymphocytes.

The hypothesis that large granular lymphocytes (LGL) are capable of directed locomotion (chemotaxis) was tested. A population of LGL isolated from discontinuous Percoll gradients migrated along concentration gradients of N-formyl-methionyl-leucyl-phenylalanine (f-MLP), casein, and C5a, well known chemoattractants for polymorphonuclear leukocytes and monocytes, as well as interferon-beta and colony-stimulating factor. Interleukin 2, tuftsin, platelet-derived growth factor, and fibronectin were inactive. Migratory responses were greater in Percoll fractions with the highest lytic activity and HNK-1+ cells. The chemotactic response to f-MLP, casein, and C5a was always greater when the chemoattractant was present in greater concentration in the lower compartment of the Boyden chamber. Optimum chemotaxis was observed after a 1 hr incubation that made use of 12 micron nitrocellulose filters. LGL exhibited a high degree of nondirected locomotion when allowed to migrate for longer periods (greater than 2 hr), and when cultured in vitro for 24 to 72 hr in the presence or absence of IL 2 containing phytohemagluttinin-conditioned medium. The chemotactic LGL was HNK-1+, OKT11+ or HNK-1+, OKT11- on the basis of monoclonal antibody and complement depletion. They did not bear either T cell or monocyte cell surface markers, exhibiting an OKT3-, OKT4-, OKT8-, OKM1-, and MO2- phenotype, and did not form E rosettes at 29 degrees C, which is characteristic of lytic NK cells in contrast to T cells. Furthermore, a rat LGL leukemia (RNK) exhibited a chemotactic response to both f-MLP and casein. LGL chemotaxis to f-MLP could be inhibited in a dose-dependent manner by the inactive structural analog CBZ-phe-met, and the RNK tumor line specifically bound f-ML[3H]P, suggesting that LGL bear receptors for the chemotactic peptide.

Animals↗