[Liver abscesses due to Yersinia pseudotuberculosis discloses a genetic hemochromatosis].
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Aged↗
Biomedical subjects
E Hernandez
Publications and source records attributed to E Hernandez.
New metallic allotropes of planar and tubular carbon
We propose a new family of layered sp(2)-like carbon crystals, incorporating five-, six-, and seven-membered rings in 2D Bravais lattices. These periodic sheets can be rolled so as to generate nanotubes of different diameter and chirality. We demonstrate that these sheets and tubes are metastable and more favorable than C60, and it is also shown that their mechanical properties are similar to those of graphene. Density of states calculations of all structures revealed an intrinsic metallic behavior, independent of orientation, tube diameter, and chirality.
Journal Article↗
Preparation and characterization of Furosemide-Eudragit controlled release systems.
Solid dispersions and physical mixtures were prepared and characterized by X-ray diffraction, infrared spectroscopy, electronic microscopy and dissolution rate studies. The characterization with X-ray diffraction showed a transition from the crystalline to the amorphous phase. A new phase near 50% Furosemide concentration with both types of carriers was present. From infrared spectroscopy strong interactions between amine and carbonyl groups from both the Furosemide and the polymers were found. Electronic microscopy analysis showed that the Furosemide changed its crystalline habit from needle to a new spherical phase, with diameter near to 1 microm. Solid dispersions were prepared in order to modify the system characteristics. The Furosemide dissolution rate was determined in order to follow the behavioural changes of the system. Scanning electron microscopy showed the presence of micro spheres within the polymeric matrix, and the channels formed due to the Furosemide dissolution inside the Eudragit: this fact modified the release pattern of the Furosemide system.
Acrylic Resins↗
Hydrogen interaction with dislocations in Si
An H plasma has a remarkable effect on dislocation mobility in silicon, reducing its activation energy to 1.2 eV. Applying density functional theory to the interactions of H and H2 with the core of the 90 degrees partial dislocation in Si, we have identified a path for motion involving kink formation and migration at hydrogenated core bonds which conforms exactly to the experimentally measured activation energy.
Journal Article↗
Subconjunctival carboplatin in retinoblastoma: impact of tumor burden and dose schedule.
OBJECTIVE: To evaluate the impact of tumor burden and chemotherapy dose scheduling on the response to subconjunctival carboplatin treatment in a murine transgenic retinoblastoma model. METHODS: Eighty simian virus 40 T antigen-positive mice were treated at age 5 or 10 weeks. Six control animals received placebo treatment. Twenty-four 5-week-old mice received 6 subconjunctival carboplatin injections at doses of 30 to 300 microg delivered at 72-hour intervals. Fifty 10-week-old mice received either 6 or 12 subconjunctival carboplatin injections at doses of 30 to 300 microg delivered at 72-hour intervals. All eyes were obtained at age 16 weeks for histopathologic examination. Eyes were graded as positive if any tumor was present. RESULTS: All simian virus 40 T antigen-positive control eyes contained large tumor foci throughout the retina. Subconjunctival carboplatin injections controlled tumors in a dose-dependent manner. Tumor control was observed in 50% of treated eyes at 138.3 microg for the 10-week-old 6-injection group, 94.3 microg for the 5-week-old 6-injection group, and 85.9 microg for the 10-week-old 12-injection group. CONCLUSION: Increased tumor burden requires an increase in subconjunctival carboplatin dose scheduling to maintain local tumor control in this murine model of retinoblastoma. CLINICAL RELEVANCE: This study documents the efficacy of subconjunctival carboplatin in the treatment of an animal model of retinoblastoma. These data establish a framework for further human clinical trials. Arch Ophthalmol. 2000;118:1549-1554
Animals↗
Design of a magnetically integrated microporous implant.
OBJECTIVE: To determine the orbital tolerance of a microporous implant fitted with an integrated stainless steel post and the enhanced motility associated with magnetic coupling of the prosthetic and the implant in a rabbit model. METHODS: Six New Zealand white rabbits underwent primary enucleation with implantation of a 12-mm microporous polyethylene implant with a 2 x 3-mm stainless steel post embedded flush with the anterior surface. At 1 month, the rabbits were fitted with an external prosthesis containing two 1-mm circular rare earth dental magnets embedded at 0. 5 mm off the midline (right and left of center at the horizon). Magnetic coupling forces were determined with a hanging block technique. RESULTS: No evidence of toxicity was observed in association with this integrated ocular implant. Magnetic coupling forces were noted maximally at 0.47 N. Clinical grading of motility documented enhancement in lateral excursion when compared with nonintegrated controls. CONCLUSION: Magnetically integrated microporous implants achieve excellent enhancement of motility without evidence of complications in this rabbit model. CLINICAL RELEVANCE: This study establishes a framework for the clinical evaluation of a magnetically integrated implant that may enhance prosthetic motility without requiring direct mechanical coupling of the implant to the prosthesis. Arch Ophthalmol. 2000;118:1259-1262
Animals↗
The significance of thrombocytosis in patients with locally advanced cervical carcinoma: a Gynecologic Oncology Group study.
OBJECTIVE: The aim of this study was to determine the incidence of thrombocytosis and its possible impact on survival probability among women with locally advanced cervical carcinoma. METHODS: The database of 294 patients with Stages IIB-IVA cervical carcinoma without periaortic node metastasis who were treated with standardized radiation therapy and concurrent hydroxyurea or misonidazole was analyzed. Pretreatment platelet counts were available for 291 patients who are the subject of this study. RESULTS: Thrombocytosis (platelet count >400 x 10(9)/liter) was present in 86 (29.6%) of the 291 patients. A multivariate Cox proportional hazards model showed that patients without extrapelvic disease and with thrombocytosis had a 55% greater chance of dying than those without thrombocytosis (relative risk = 1.55, 95% confidence interval 1.08-2.21). Patients with thrombocytosis had larger tumors and more frequently had bilateral parametrial involvement, tumor fixation to the sidewall, and positive pelvic lymph nodes than patients without thrombocytosis. Thrombocytosis was not found to be a prognostic factor in patients with positive pelvic nodes. However, in patients with negative pelvic nodes, the presence or absence of thrombocytosis was related to survival. CONCLUSION: Thrombocytosis is a frequent finding among patients with advanced cervical carcinoma and seems to be related to tumor burden. Among patients with locally advanced cervical carcinoma who had negative pelvic nodes, those with thrombocytosis had a poorer survival.
Adult↗
Study of sesquiterpene lactones from Milleria quinqueflora on their anti-inflammatory activity using the transcription factor NF-kappa B as molecular target.
In Central America aerial parts of the Asteraceae Milleria quinqueflora are used in traditional medicine as a remedy for skin infections. Reinvestigation of this plant afforded thirteen sesquiterpene lactones (Sls), three of them are new. All isolated Sls were studied for their anti-inflammatory activity using the transcription factor NF-kappa B as molecular target. NF-kappa B is involved in the synthesis of inflammatory mediators, such as cytokines and chemokines. NF-kappa B DNA binding was inhibited at micromolar concentrations by all Sls.
Anti-Inflammatory Agents, Non-Steroidal↗
Role of persistent amenorrhea in bone mineral metabolism of young hemodialyzed women.
BACKGROUND: Chronic renal failure in women is frequently associated with endocrine disturbances leading to menstrual disorders. However, most studies on renal osteodystrophy have not taken into account the possible role of these hormonal disturbances on the pathogenesis of bone alterations seen in these patients. In the present study, we evaluated bone mineral metabolism in a group of young hemodialyzed women with persistent amenorrhea and compared them with similar women with regular menstruation. METHODS: We studied 74 women who were further subdivided into 43 women with regular menstrual periods and 31 women with persistent amenorrhea, defined as the absence of menstrual bleeding for more than six months. In all patients, we performed a bone mineral density (BMD) analysis and simultaneously evaluated different biochemical parameters, intact parathyroid hormone (iPTH), sexual hormone determinations that included total estradiol, follicle-stimulating (FSH), and luteinizing hormone and markers of bone resorption such as the procollagen type 1 cross-linked carboxy-terminal telopeptide (ICTP). RESULTS: Serum calcium, phosphorus, and iPTH were similar in both groups. Serum alkaline phosphatase was higher in amenorrheic women. Although the total serum estradiol concentration was normal in the amenorrheic women when compared with nonuremic women, the values were significantly lower than those in regularly menstruating women. Serum FSH and ICTP values were significantly higher in the amenorrheic women. Trabecular BMD in the lumbar spine was also significantly lower in the amenorrheic women compared with regularly menstruating dialysis patients. Lumbar spine BMD and total estradiol levels correlated significantly in the amenorrheic group. CONCLUSIONS: These studies show that persistent amenorrheic young women on dialysis have lower trabecular BMD and evidence of increased bone resorption when compared with normal menstruating women on dialysis. The possible impact of these results in the natural history of the uremic osteodystrophy remains to be determined.
Adult↗
Decreased virulence of a strain of Pseudomonas aeruginosa O12 overexpressing a chromosomal type 1 beta-lactamase could be due to reduced expression of cell-to-cell signaling dependent virulence factors.
Pseudomonas aeruginosa produces a large variety of virulence factors and is characterized by its capacity to rapidly develop resistance when exposed to antibiotics. In order to evaluate a possible correlation between acquired resistance to antibiotics and virulence, we examined the virulence of four isogenic variants of P. aeruginosa O12 that differ in their resistance phenotypes to various beta-lactam antibiotics in a mouse model of acute pneumonia. Strains overproducing a chromosomal type 1 beta-lactamase were less virulent in both immunocompetent and immunosuppressed animals. Whereas the production of the exopolysaccharide alginate was similar between the four strains, extracellular virulence factors (elastase, rhamnolipid) that are controlled by the cell-to-cell signaling system circuit were detected in reduced amounts in the supernatant of the two isolates overproducing type 1 beta-lactamase. These results suggest that strains overexpressing the chromosomal type 1 beta-lactamase could be less virulent because of a reduction of cell-to-cell signaling dependent virulence factor production.
Alginates↗
Super-infection by Bacillus thuringiensis H34 or 3a3b can lead to death in mice infected with the influenza A virus.
Bacterial super-infections are the main cause of complication and mortality after influenza virus (IAV) infection. Since Bacillus thuringiensis (Bt) is considered non-pathogenic for humans and is widely sprayed in urban areas, the aim of this work was to evaluate the potential pathogenicity of a combined infection Bt-IAV in a mouse model of pneumonia. Bacteria used for super-infections were Bt serotype H34 isolated from human infection and the insecticidal strain 3a3b obtained from a commercial source. Virus strain was A/Scotland/20/74 (H3N2) adapted to BALB/c mice by serial lung passage. Combined infection with 4% of the viral lethal dose 50% (LD(50)) and 10(2) spores of Bt H34 killed 40% of the mice. Mortality rates increased up to 55% and 100% when combined infections were done with respectively 10(4) and 10(7) spores. The insecticidal strain Bt 3a3b was less pathogenic than Bt H34. A dose of 10(4) spores associated with 4% of IAV LD(50) killed 50% of the mice. This inoculum must be compared with the doses usually sprayed in agriculture: 10(11) spores m(-2). Total protection against super-infection was obtained when mice were treated with amantadine. Even if only a few cases of Bt human infection have been reported, these results suggest a possible risk for workers spraying Bt-based biopesticides during flu outbreaks.
Administration, Oral↗
Angiographic anatomy of the inferior right atrial isthmus in patients with and without history of common atrial flutter.
BACKGROUND: Although most ablative procedures undertaken for common atrial flutter target the inferior right atrial isthmus, comparative studies of the morphology of this area are lacking. Our study examines its angiographic anatomy, making correlations with postmortem specimens, to provide a better understanding of the anatomic substrate of this arrhythmia. METHODS AND RESULTS: The gross morphological features and dimensions of the area between the orifice of the inferior caval vein and the attachment of the septal leaflet of the tricuspid valve were determined from angiograms made in 23 patients with documented atrial flutter and 30 control subjects. For comparison, we studied 20 normal heart specimens. When viewed in right anterior oblique projection, 2 morphologically distinct areas were identified. In the specimens, the inferior isthmus measured a mean length of 30+/-4 mm, not significantly different from the dimensions obtained from angiograms of control subjects. The mean length of the isthmus, however, was greater in patients with common atrial flutter than those without (37+/-8 versus 28+/-6 mm). Patients with atrial flutter and structural heart disease had an even longer isthmus than those with flutter alone (39. 6+/-8 versus 33+/-7 mm). Compared with those without flutter, the atrial diameter was also larger in patients with flutter (57.6+/-9 versus 48.5+/-6 mm). Reevaluation carried out at follow-up 10+/-2 months after ablation did not show any reduction in atrial size, although contractility improved. CONCLUSIONS: The inferior isthmus and right atrium in patients with common atrial flutter were significantly larger than those in a control population.
Adult↗
Mycophenolate mofetil, cyclosporine, and steroids after renal transplantation: five-year results at a single center.
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Adult↗
The early impact of mycophenolate mofetil in combination with steroids and cyclosporine Neoral after renal transplantation: a six-month analysis.
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Adult↗
Embolization of an anomalous bronchial artery aneurysm in a patient with agenesis of the left pulmonary artery.
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Aneurysm↗
Recent reformulations of Freud's development and abandonment of his seduction theory: historical/scientific clarification or a continued assault on truth?
It is well known that, as part of Freud's early work with "hysteria," he reported making discoveries of sexual abuse that he interpreted first as genuine but subsequently as fantasy. Several writers now argue that Freud never made such discoveries; rather that he lied about them, only inferred abuse from his patients' symptoms, or suggested false memories to his clients. The present authors evaluate Freud's original work and these recent claims and conclude that (a) they are not new and are similar to the original reaction that Freud received; (b) the assertion that Freud did not make discoveries of abuse is unwarranted; and (c) these recent writers frequently have supported their positions by misrepresenting what Freud actually wrote, ignoring evidence that contradicted their position, failing to consider obvious and more plausible explanations for Freud's behavior, and going beyond the available data and stating with certainty what cannot be determined.
Child↗
Stroke in Hispanic veterans: a descriptive study.
BACKGROUND: Differences in risk factor prevalence and distribution of atherosclerotic cerebrovascular disease have been reported among different racial-ethnic groups. Identification of stroke syndromes and risk factors specific to the Puerto Rican male population should lead to more effective diagnosis, treatment, and prevention programs. METHODS: We prospectively and consecutively evaluated 118 Hispanic male veterans admitted to our Stroke Unit from June 1994 to September 1995. RESULTS: Ninety patients (76%) had an ischemic infarct, 26 (22%) had a transient ischemic attack, and 2 (2%) had an intracerebral and/or subarachnoid hemorrhage. Hypertension was the most common risk factor. Echocardiographic studies were done in 64% of the patients, and the most common findings were concentric left ventricular hypertrophy and diastolic dysfunction. Cerebral angiography was done in 40 cases, and findings were abnormal in 32 (80%). CONCLUSIONS: We believe this is the largest descriptive study of Hispanic male veterans with stroke syndromes. It provides baseline data to serve as a comparison group for future research.
Adult↗
Bacillus thuringiensis serotype H34 isolated from human and insecticidal strains serotypes 3a3b and H14 can lead to death of immunocompetent mice after pulmonary infection.
In 1995, we isolated a strain of Bacillus thuringiensis serotype H34 from severe human tissue necrosis. This bacterium was able to induce myonecrosis in immunosuppressed mice after cutaneous infection. Its potential pathogenicity for immunocompetent hosts was investigated in a mouse model of pulmonary infection. Mice infected intranasally by a suspension containing 10(8) spores died within 8 h in a clinical toxic-shock syndrome. In the same conditions, infection with a mutant without crystalline toxin, with the supernatant from a culture containing 10(8) bacteria ml(-1) and by the insecticidal strain serotypes 3a3b or H14 led to identical results. Lower inocula simply induced a local inflammatory reaction with bacterial persistence observed during the course of 10 days.
Animals↗