Search PubMed⌕ Search

Biomedical subjects

M Herrera

Publications and source records attributed to M Herrera.

At least 73 records · Page 4Linked to original sources
PubMed1996

An open, multicenter clinical trial of piperacillin/tazobactam in the treatment of pediatric patients with intra-abdominal infections.

A total of 60 children with secondary peritonitis were enrolled in an open, non-comparative multicenter study designed to evaluate the safety, tolerance and efficacy of parenteral piperacillin/tazobactam (80/10 mg/kg every 8 hours) in young children. The most common diagnosis was perforated appendicitis (90%) and the three most common pathogens, obtained from the peritoneal cavity, were Escherichia coli (52 isolates), Pseudomonas aeruginosa (16 isolates) and Bacteroides sp. (19 isolates). Patients were examined daily during therapy, 4-14 days and 4-6 weeks post-therapy. Of the 60 patients, 43 were evaluable. The majority of patients had polymicrobial infections (36 patients). All the aerobic isolates were susceptible to piperacillin/tazobactam while 19 were resistant to piperacillin alone. Four of 43 clinically evaluable patients were considered a clinical failure and 3 of 40 bacteriologically evaluable patients were considered to have an unfavorable microbiological response. There were 2 clinically adverse events considered related to the study drug and several possibly related, mild and transitory, abnormalities in eosinophil counts and liver function tests. Based on the safety and efficacy results from this study, the advantages of using a single agent for the treatment of mixed infections of the peritoneal cavity and its potential activity against resistant organisms, we believe that further comparative clinical trials in children with intra-abdominal infections are warranted.

Bacteria, Aerobic↗
PubMed1996

Gastrin levels in mothers and neonates at delivery in various perinatal conditions.

BACKGROUND: This study was designed to assess the variations of gastrin (Ga) serum levels in mothers and newborns at birth in some perinatal disorders. MATERIALS AND METHODS: Ga levels were measured by RIA in maternal serum, amniotic fluid and cord sera of newborns in 55 cases with the following conditions: normal pregnancy and eutocic vaginal delivery (n = 8), repeat cesarean section (n = 10), and cardiotogographic register suggestive of fetal compromise (n = 15), cephalopelvic disproportion (n = 8), preeclampsia (n = 7) and postdate pregnancy (n = 7). Statistical analysis was performed by Mann-Whitney U test. RESULTS: Ga levels in cord sera of newborn and amniotic fluid in normal pregnancy and eutocic delivery were significantly higher (p < 0.02 and p < 0.01, respectively) than those found in patients with repeat cesarean operation. Serum Ga concentrations in women with postterm pregnancy were significantly higher (p < 0.02) than in women with prior cesarean section. Ga levels in amniotic fluid samples in the presence of suspected fetal compromise and postdate pregnancy were significantly higher (p < 0.001) than those observed in women who had repeat cesarean operation. CONCLUSION: Vaginal delivery and perinatal pathology may induce hypergastrinemia in both mother and neonate at birth.

Adult↗
PubMed1996

[Preventive program of birth defects: incidence of anencephaly in Maracaibo, Venezuela. 1993-1996 period].

Incidence of anencephaly in the State of Zulia, and specifically in the Eastern Coast of Lake Maracaibo, an oil exploitation area, has been declared high since the beginning of the 80's, coincident with the generalized use of ultrasound as a diagnostic tool for fetal evaluation. Through the Birth Defects Preventive Program, established at the Hospital Chiquinquirá in Maracaibo, we have developed a fourfold strategy for the study of birth defects: i) analysis of more than 32,332 ultrasound evaluations within the Ultrasound Service, between 1993 and 1996, ii) a case-control malformation registry beginning in 1995, iii) a study of malformed stillbirths at the Pathology Service, observed after 4232 deliveries within this hospital, and iv) a registry of over 638 mothers with high risk pregnancy for fetal defects detected at the prenatal clinic and carried out at the Perinatal Medical Genetics Service. As a reference population we study 345 medical histories obtained from the Medical Genetics and Prenatal Diagnostic Service at Hospital Coromoto, and oil companies related medical facility. This approach has led us to conclude that the incidence of anencephaly in the State of Zulia is 0.75/1000, significantly similar to that expected for most populations.

Anencephaly↗
PubMed1995

Prediction on admission of in-hospital mortality in patients older than 70 years with acute myocardial infarction.

STUDY OBJECTIVE: To identify the differential characteristics regarding risk factors, presentation, and clinical status on hospital admission in patients aged 70 years or older with acute myocardial infarction (MI) of less than 24 h of evolution, compared with patients younger than 70 years, and to analyze possible factors that could affect mortality on admission in the group of patients older than 70 years. STUDY DESIGN: Of 1,289 patients admitted in the coronary care unit with acute MI during the period 1988 to 1991, with a delay from onset of symptoms of less than 24 h, we defined two groups according to age: younger than 70 years (group 1) and 70 years or older (group 2) in order to analyze the possible predictive factors for mortality on hospital admission in patients older than 70 years (n = 322). By means of univariate analysis, we studied clinical variables that were present on admission; age; sex; medical history of diabetes, cerebrovascular accident, stable angina, previous MI, cardiac failure, right bundle branch block, and atrial fibrillation; previous treatment with digoxin, calcium antagonists, angiotensin-converting enzyme inhibitors (ACEI), antiaggregants or beta-blockers; location and extension of the acute MI, and thrombolysis. The association between mortality, as the dependent variable, and all other variables, as independent variables, was evaluated using a stepwise logistical regression procedure. RESULTS: In patients older than 70 years of age, the model included the following as independent predictors of mortality: female sex (odds ratio [OR], 2.59); complete right bundle branch block (CRBBB) (OR, 4.88); Q-wave MI (OR, 0.35 for non-Q-wave MI); and Forrester grade 2 to 3 (OR, 6.36) and 4 (OR, 80.14). CONCLUSIONS: In patients with acute MI and older than 70 years at the time of admission to the coronary care unit, together with the variables indicating the degree of hemodynamic involvement and the extension of the acute MI, factors such as female sex and CRBBB stand out as independent predictors of mortality.

Aged↗
PubMed1994

Molecular characterization of HLA class II genes in celiac disease patients of Latin American Caucasian origin.

In the present study, the polymorphic domain of HLA class II genes present in a pediatric population of Argentinian celiac disease patients was analyzed by hybridization to sequence-specific oligonucleotides and DNA sequencing. Sixteen out of 16 DR5/7 heterozygous patients bore the DQA1*0501 and DQB1*0201 alleles implicated in the DQ2 risk specificity. The second exon of DQA1, DQB1 and DRB1 genes from 2 DR5/7 patients was characterized by DNA sequencing. The following alleles were found in both patients: DRB1*1101 and DRB1*0701; DQB1*0301 and DQB1*0201; DQA1*0501 and DQA1*0201. Previous serological analysis in this population had shown the presence of DQ2 in 95% of the patients (40% in controls) and a negative association with DQ1 haplotypes, suggesting the presence of other "permissive" or neutral alleles. The following HLA-DQB1 alleles, besides DQB1*0201, were identified in 31 CD patients: DQB1*0301, 0302, 0401 and 0402. All these alleles share a common pattern of residues between positions 84 and 90, and distinct from that present in DQ1-related alleles.

Alleles↗
PubMed1994

Effect of policosanol on isoprenaline-induced myocardial necrosis in rats.

Policosanol is a mixture of higher aliphatic primary alcohols isolated from sugar cane (Saccharum officinarum L.) and octacosanol represents its main component. This study was conducted to examine the effects of policosanol on myocardial necrosis induced by subcutaneous injection of isoprenaline in rats. A significant reduction (P < 0.01) of infarct size, polymorphonuclear cells and mast cells was observed in animals treated with policosanol at 5 or 25 mg kg-1, while animals receiving only acetysalicylic acid pretreatment showed a significant decrease in the infarct area (P < 0.05). No significant differences in polymorphonuclear and mast cells were obtained when compared with positive control data. It is concluded that policosanol delays the evolution of infarction, showing a protective effect on the myocardial necrosis induced by isoprenaline in this experimental model.

Administration, Oral↗
PubMed1994

Projections from the primary auditory cortex onto the dorsal cortex of the inferior colliculus in albino rats.

The topography of connections from the primary auditory cortex (Te1) onto the dorsal cortex (DC) of the inferior colliculus (IC) was studied using the anterograde neural tracers Phaseolus vulgaris (PHA-L) and Biotinylated dextran amine (BDA). Injections in different restricted portions of the ventral Te1 showed labelled axonal sheets in the ipsilateral DC with extensions in the central nucleus and the external cortex. Also contralateral labelled axons were found with a patchy appearance. The pattern of labelled axonal laminae is arranged in an orderly fashion, so that a correlation exists between the injection field (antero-to caudoventral injections) and the pattern of labelled axonal sheets (from a ventromedial to a dorsolateral arrangement) in the IC. However, variations from this pattern were observed. Also only the injections made in rostral and middle parts of Te1 V are orderly arranged in the territory of the DC, while the Te1 V caudoventral projection partially overlaps those from antero and mid-central regions. A topographical arrangement in the fibre projection from the medial and dorsal zones of Te1 (Te1 D) exists in the neuropil of the IC. The bands from Te1 D overlapped with the bands from Te1 V but in different order. This indicates that the projection of the mid-dorsal zone of Te1 is not topographically arranged in the DC like Te1 V. Based on the results we have obtained, there is strong evidence that the projection from Te1 V to the DC is topographically organized in a rostrocaudal sequence which gives definite terminal fields. However, each of these fields (medial, central and external) receives a principal bulk of primary auditory cortical fibres and a supplementary one. This implies that territories of the DC which contain neurons responsive to low frequencies receive a projection from Te1 fields with neurons which are responsive to high or to low frequencies.

Acoustic Stimulation↗
PubMed1994

[Cystic hygroma. Antenatal diagnosis and clinical management].

Nine cases of cystic hygroma in pregnancy diagnostic by ultrasound are presented. Chromosomal abnormalities accompany in 7 cases occurred, with, great frequency of "Turner Syndrome". The prognostic of this congenital malformation, has relation with the chromosomopaty and the difference between septal and nonseptated cystic hygroma.

Adolescent↗
PubMed1994

[Listeria infections and pregnancy].

One clinical case of lysteriosis during pregnancy, diagnosed in the puerperium period is analyzed. Both the mother and the newborn recovered favorably.

Adult↗
PubMed1994

[Experience with prostaglandins E2 in intracervical gel and intravaginal tablets in fetal deaths].

Our clinical experience with E2 prostaglandins in intracervical gel and vaginal tablets to induce deliveries or abortions with dead fetuses is presented. The overall success rate of 50 patients was 70%, excluding 9 cases of anencephalos fetuses; the rate is increased to 77.7% in the cases of retained abortions and to 78.3% in the cases of dead fetuses in uterus after 20 weeks of gestation.

Abortion, Induced↗
PubMed1994

[Leishmaniasis in Ecuador. 1. Incidence of cutaneous leishmaniasis on the Pacific coast].

A clinico-epidemiologic survey on cutaneous leishmaniasis, due to Leishmania panamensis, was carried out on 961 persons in two study areas of the Pacific coast of Ecuador, to estimate the prevalence and the incidence of the disease. In the preandean hills, at Paraiso Escondido, the prevalence of active lesions was 4.8%; in the hills of the coastal cordillera, at La Tablada, it was 3.6%. The incidence of new cases in 1991 was high: 147% in the first village, and 106% in the second. These data are far higher than the Health Ministry statistics. The cumulated prevalence, obtained by addition of the scars and active lesions of leishmaniasis, was as high as 66% at Paraiso Escondido, and 47% at La Tablada. Most of the patients (62%) had only one ulcer or scar. Most of the people are contaminated during the first five years they live in these endemic areas. Nevertheless, the incidence remains high in all the age groups, because large numbers of migrants coming from non endemic regions are continuously settling in these colonization areas. Interviews have shown that the contaminations had occurred in the dry season, between July and December. These findings were confirmed by passive case detection at the Hospital A. Egas of Santo Domingo which covered the region. Contamination of young children and position of the lesions on the face suggested a domiciliary transmission, like in Panama and on the Pacific coast of Colombia.

Adult↗
PubMed1993

A conserved region of the MSP-1 surface protein of Plasmodium falciparum contains a recognition sequence for erythrocyte spectrin.

The major surface protein MSP-1 of Plasmodium falciparum blood-stage malaria parasites contains notably conserved sequence blocks with unknown function. The recombinant protein 190L, which represents such a block, exhibits a high affinity for red blood cell membranes. We demonstrate that both 190L and native MSP-1 protein bind to the inner red blood cell membrane skeleton protein spectrin. By using overlapping peptides covering the 190L molecule, we show that the spectrin contact site of 190L is included in a linear sequence of 30 amino acid residues. Association of 190L with naturally occurring spectrin deficient red blood cells is drastically reduced. In the same cells parasite invasion is normal, but the intracellular parasite development arrests late in the trophozoite stage. A similar situation arises when synthetic peptides covering the spectrin recognition sequence of 190L are added to P.falciparum cultures. These data and the cellular localization of MSP-1 suggest the possibility that MSP-1 associates with spectrin under natural conditions.

Amino Acid Sequence↗
PubMed1993

Intervertebral disc herniations (limbus vertebrae) in pediatric patients: report of 15 cases.

A revision of 15 cases of back pain and radiological features characteristic of anterior or posterior limbus vertebrae is presented. We comment on the radiological findings observed in the various imaging studies performed (conventional radiology, CT and MRI), which were attributed to the herniation of disc material into the vertebral body. In three patients who were followed up 12 years after the diagnosis, the initial roentgenograms of limbus vertebrae progressed in adult hood into radiological images characteristic of Schmorl's hernia as a sequela.

Adolescent↗
PubMed1993

Acute ischemic stroke from fibrocartilaginous embolism to the middle cerebral artery.

BACKGROUND AND PURPOSE: Fibrocartilaginous embolism from the nucleus pulposus has been reported as a rare cause of spinal cord ischemia. We were unable to find previous reports of embolism from this source to cerebral arteries. CASE DESCRIPTION: A previously healthy 17-year-old girl fell during a basketball game. Left hemiparesis and unresponsiveness developed followed by signs of right uncal herniation and death over a 3-day period. There was no evidence of neck, head, or spine trauma, and cardiac evaluation was normal. Neuropathological examination showed extensive ischemic infarction of the right middle cerebral artery territory, brain edema, and herniation. Complete embolic occlusion of the right middle cerebral artery by fibrocartilaginous material, consistent with nucleus pulposus, was documented. Small, terminal coronary artery branches also showed embolism by the same material and limited areas of myocardial infarction. CONCLUSIONS: Acute cerebral embolism after minor trauma in a young patient may be rarely due to fibrocartilaginous embolism from the nucleus pulposus. The pathogenesis of this problem remains poorly understood, but systemic embolism appeared to have occurred in this case.

Adolescent↗