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Biomedical subjects

M Herrera

Publications and source records attributed to M Herrera.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

Quantitative corneal anatomy in emmetropic subjects.

PURPOSE: Currently there is little information available about the corneal thickness values of healthy emmetropic subjects. Therefore, the authors decided to analyze the corneal thickness in healthy emmetropic subjects. METHODS: The authors analyzed the difference in thickness values between the thinnest corneal site and the central and paracentral cornea in 124 eyes of 124 healthy emmetropic white subjects. RESULTS: The mean difference between the thinnest site of the cornea and the thickness values obtained in the areas analyzed was as follows: 12+/-6 microm center; 140+/-19 microm superonasal; 133+/-23 microm nasal; 117+/-26 microm inferonasal; 122+/-19 microm superotemporal ; 89+/-22 microm temporal; and 99+/-29 microm inferotemporal (p<0.001; one way analysis of variance test). CONCLUSIONS: In healthy emmetropic white subjects the thinnest site of the cornea is statistically lower than the central and paracentral cornea.

Adolescent↗
PubMedDate not supplied

Development of cutaneous sarcoidosis in a patient with chronic hepatitis C treated with interferon alpha 2b.

BACKGROUND: Sarcoidosis is a multisystemic granulomatous disorder of unknown etiology that most commonly affects young adults. A probable induction of sarcoidosis by interferons (IFN) has been published. To this date, few cases of cutaneous sarcoidosis inpatients with chronic hepatitis C under interferon treatment have been reported. OBJECTIVE: We describe a 50-year-old woman with chronic hepatitis C who developed lesions of cutaneous sarcoidosis three months after IFN treatment. CONCLUSIONS: The possible role of INF therapy in the development of cutaneous sarcoidosis in a patient with chronic hepatitis C should be considered.

Antiviral Agents↗
PubMedDate not supplied

Pheochromocytoma and clear-cell renal carcinoma in a child with von Hippel-Lindau disease: a patient report.

A 6 year-old boy with von Hippel-Lindau (VHL) disease presented with hypertension due to bilateral pheochromocytomas. At age 13 he developed a renal carcinoma and bilateral paragangliomas. His mother had retinal angiomas, bilateral pheochromocytomas and a cerebellar hemangioblastoma. This unusual presentation illustrates the complexity and difficulties associated with the management of VHL disease.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

A comparison of the hydrodynamical behaviour of three heart aortic prostheses by numerical methods.

The behaviour of the blood flow passing through artificial heart values in aortic position is numerically simulated by discretizing the Navier-Stokes equations for viscous incompressible flow through the finite element method. Three different artificial valves, Starr-Edwards, St Jude and disc valves, are modelled by using the finite element method as well as the Navier-Stokes equations for viscous incompressible flow. The blood flow behaviour is characterized by discretizing both planar and axisymmetric domains of the value devices. The streamlines as well as the velocity distributions are studied and compared. Likewise, the pressure patterns are analysed and compared. Some numerical examples of the three valves are presented and discussed herein.

Algorithms↗
PubMedDate not supplied

Antibacterial activity of glass-ionomer restorative cements exposed to cavity-producing microorganisms.

The antibacterial activity of the glass-ionomer restorative cements Ketac-Fil, Ketac-Silver, Fuji II LC, and Vitremer was studied in vitro, in conjunction with a total of 32 strains of five bacterial genera that may be associated with dental caries: Streptococcus spp, Lactobacillus spp, Actinomyces spp, Porphyromonas spp, and Clostridium spp. Agar plate diffusion was the method used for the bacterial cultures, which included a chlorhexidine control. All four glass-ionomer cements were found to inhibit bacterial growth, though with noteworthy differences in their spheres of action. Vitremer was the cement determined to have the greatest antibacterial effects, whereas Ketac-Silver presented the least inhibitory action.

Actinomyces↗
PubMedDate not supplied

Antibacterial activity of resin adhesives, glass ionomer and resin-modified glass ionomer cements and a compomer in contact with dentin caries samples.

A total of 103 clinical samples of carious dentin were used to study the antibacterial action of different dental resin adhesive materials (Gluma 2000, Syntac, Prisma Universal Bond 3, Scotchbond Multi-Purpose and Prime&Bond 2.0) glass ionomer cements (Ketac-Cem, Ketac-Bond, Ketac-Silver, Ketac-Fil) resin-modified glass ionomer cements (Fuji II LC, Vitremer and Vitrebond) and a compomer (Dyract). The agar plate diffusion method was used for the microbial cultures and a chlorhexidine control. The growth of the caries-producing microorganisms was effectively inhibited by the Vitremer and Vitrebond cements, and to a lesser extent by the Scotchbond Multi-Purpose adhesive system. Overall, there were statistically significant differences in the antibacterial activity of the products tested.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Benign encephalitis of the brain stem].

INTRODUCTION: The secondary encephalitis disorders are due to an immunological mechanism which causes demyelinating lesions of the central and peripheral nervous systems, with very variable clinical features. The pathogenesis and localization of benign encephalitis of the brain stem and the Miller Fisher syndrome (MFS) are still subject to debate. It is suggested that they may both belong to different extremes of the same nosological spectrum known as the ophthalmoplegia-ataxia-areflexia syndrome. CLINICAL CASE: We report the case of an 11 year old boy with encephalitis of the brain stem who had electromyographic alterations compatible with the Guillain-Barré syndrome, and MR images characteristic of an acute demyelinating disorder of the brainstem. CONCLUSIONS: The encephalitis of the brain stem is an uncommon condition in children which leads to diagnostic difficulty at its onset, since this is similar in other disorders such as MFS, tumours, cerebrovascular accidents and less often in the initial stages of multiple sclerosis. The clinical course is very useful to distinguish between these conditions. MR is the imaging technique of choice for diagnosis in these patients. Although there is currently no specific treatment for post-infectious encephalitis, the use of high doses of immunoglobulins may be justified in view of the physiopathological origin of the condition.

Bradycardia↗
PubMedDate not supplied

[Endoscopic esophagitis findings in patients with gastroesophageal reflux symptoms].

The experience concerning the findings of endoscopical esophagitis in patients with reflux symptoms studied between January 1984, and December 1986, is presented. Endoscopical esophagitis, according to the European classification was found in 5% of the patients. Grade I (mild) and Grade III (Barrett) were the most frequent findings. Symptoms were similar to those reported in the international literature. No difference in age, sex distribution, for each group of esophagitis were seen. The distance of the squamous-columnar limit from the incisors was significantly higher in patients within esophagitis group III or IV.

Adolescent↗
PubMedDate not supplied

HLA and celiac disease in Argentina: involvement of the DQ subregion.

A population of 62 unrelated homogeneous Argentinian celiac pediatric patients were typed for HLA-A,B,C,DR, and DQ antigens. The association between celiac disease and the DR3 and DR7 antigens was confirmed. The specificity DQw2 was present in 95.2 per cent of the patients. Nevertheless, it was of interest that the most significant phenotypes observed were DR3/DR7, DR7/DR5, and DR3/DR5. The significance of these findings is discussed.

Alleles↗
PubMedDate not supplied

[Surgical anatomy of tetralogy of Fallot].

We analyzed 131 hearts with tetralogy of Fallot for their prominent surgical anatomical features. Special attention was paid to the different elements of the right ventricular outflow tract obstruction, the supraventricular bands and types of septal defect and their relations with the conducting tissue and coronary supply. The infundibular region proved to be the core of the malformation in tetralogy, the left and anterior septal deviation being the origin of pulmonary stenosis and the rest of the embryopathological elements that characterize this malformation. Our results support the notion that each case has, besides the general features of the malformation, particular aspects which must be analyzed. This conjunction of general and particular features provides the clinician with a morphological basis for the interpretation of the diverse diagnostic procedures and the surgeon with the general scope of tetralogy and the individual features of each case which must be taken into account in the choice of the best possible surgical procedure.

Humans↗