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Biomedical subjects

C Escobar

Publications and source records attributed to C Escobar.

51 records · Page 3Linked to original sources
PubMed1989

[In vitro culture of melanocyte-bearing epidermis and its application in the treatment of vitiligo and the stable leukodermas].

Skin specimens were cultured in vitro in a attempt to reproduce epidermal sheets bearing melanocytes. After exploring different parameters and culture conditions, 16 out of 45 samples yielded pigmented epidermal membranes with melanocytes. This epidermis bearing melanocytes was transplanted to a patient with segmental vitiligo and a satisfactory repigmentation was achieved. The factors contributing to the development of this pigmented in vitro cultured epidermis, and the potential of this technology for treating refractory but stable forms of vitiligo, are discussed.

Adult↗
PubMed1987

On the pathogenesis of idiopathic guttate hypomelanosis.

Idiopathic guttate hypomelanosis is a common leukodermic dermatosis of obscure origin, consisting of small 2- to 5-mm achromic or hypopigmented macules, mainly affecting the exposed upper and lower extremities. In a group of 400 consecutive dermatologic patients, idiopathic guttate hypomelanosis was much more prevalent in women than in men. However, in both sexes this prevalence became more common with advancing age. In another group of fifteen patients with idiopathic guttate hypomelanosis and fifteen normal controls matched by age, sex, and skin type, the following was found: A cause-effect relationship between chronic actinic exposure and the development of idiopathic guttate hypomelanosis could not be established by statistical studies. A family aggregation survey disclosed a higher prevalence of idiopathic guttate hypomelanosis in the family of patients with idiopathic guttate hypomelanosis than in the control group. Epithelial atrophy, patchy absence of melanocytes and melanin, flattening of the rete pegs, and basket weave hyperkeratosis were the most prominent histologic findings of idiopathic guttate hypomelanosis. Minigrafts of normal skin implanted in idiopathic guttate hypomelanosis lesions did not modify the achromic defects, whereas intralesional triamcinolone with or without grafts improved the appearance of these lesions.

Adult↗
PubMed1986

A comparative study between injectable low-temperature (70 degrees C) gutta-percha and silver amalgam as a retroseal.

This study compared two different dental materials used in endodontic retrosealing procedures. One of these materials was a new low-temperature gutta-percha product, manufactured by the Hygenic Corporation, that involved an injection technique. The second of these materials was silver amalgam. Silver amalgam was selected because it has been recognized by many clinicians as the most effective apical sealing material. Two groups of ten recently extracted teeth were endodontically prepared with one of each of the materials being tested, and the effectiveness of these materials as sealants was determined by their ability to inhibit the penetration of methylene blue dye for a predetermined period of time through the apically sealed root tips. Preliminary results obtained indicated that, although these materials were not 100% effective in inhibiting the dye penetration, each was as effective as the other when evaluated by two observers following completion of the study as determined by its experimental design. No significant difference was exhibited between the amalgam group and the gutta-percha group. The leakage of the dye that was observed in each of the groups might have been caused by the ineffectiveness of, or the ineffective use of, the nail polish or cyanoacrylate used to coat all but the apically sealed tips of the endodonticalled prepared teeth. The function of these coating materials was to prevent penetration of the dye through the surface of the body of the root.(ABSTRACT TRUNCATED AT 250 WORDS)

Dental Amalgam↗
PubMed1984

Massive pleural effusions in cirrhotic patients with ascites.

A method is described based on the passage of air across the diaphragm to detect pathological diaphragmatic orifices in autopsies. This method was used in 65 post-mortem studies; orifices were detected in 7 cases. Only one of these appears histologically to be a real spontaneous orifice. This was found in the post-mortem study of a cirrhotic patient with ascites and massive and recurrent hydrothorax. In eight patients with cirrhotic ascites and pleural effusions, radioisotopes were introduced into the ascites fluid, and only in two of them, both with right massive and recurrent pleural effusion, was radioactivity detected in the pleural cavity within the 1st h after injection. The radioisotopic method for detecting in vivo these orifices avoids the repeated taps that are necessary when dyes are used.

Ascites↗
PubMedDate not supplied

Vertical induction of the inclusion body hepatitis/hydropericardium syndrome with fowl adenovirus and chicken anemia virus.

The hypothesis that fowl adenovirus (FAV) and chicken anemia virus (CAV), transmitted vertically and simultaneously, induce the inclusion body hepatitis (IBH)/hydropericardium (HP) syndrome in progeny chickens was tested. Thus, 35-wk-old light brown layer breeders, showing absence of antibodies against FAV and variable titers against CAV, were intramuscularly singly infected with the FAV serotype 4 isolate 341 or dually infected with CAV (isolate 10343) and FAV. All hens (groups A [FAV alone], B [FAV + CAV], and C [noninfected]) were clinically healthy throughout the experimental period. Both infectious viruses FAV and CAV were isolated from progenies obtained as early as 5 days after infection of their breeders. Hematocrit, serum proteins, and aspartate-aminotransferase values showed a few statistical differences between the progeny groups. Most of these differences were detected in the progeny chickens of group B. However, almost all values met reference values for the species. The pathologic findings showed that progeny chickens obtained from both singly and dually infected breeders developed macroscopic and histopathologic changes of IBH/HP. The pathologic findings shown by progeny chickens of group A (FAV) were not expected because neither synergism nor prior immunodepression by CAV was concurrent. Chickens of group B (CAV + FAV) also developed IBH/HP. Although not many differences in the evaluated parameters between groups A and B were statistically significant, most pathologic findings of group B indicated a more severe manifestation of the disease. However, because FAV alone did reproduce the syndrome, the results shown by group B would not allow a definitive confirmation of the hypothesis that the association of FAV and CAV is necessary for the successful induction of the IBH/HP syndrome in chickens when transmitted vertically.

Adenoviridae Infections↗
PubMedDate not supplied

Effects of thyroxine on the development of self-grooming behavior in rats.

The effects of intraperitoneal thyroxine administration (1 microgram/body weight) on postnatal days 1-3 and the subsequent alterations upon the development of six self-grooming components were measured postnatally in male Wistar rats between days 1-60. Observations on self-grooming components showed that thyroxine-treated rats did not show consistent significant differences in the duration of grooming movements of short displacement directed to the forepaws and head throughout the study, as compared to controls. By contrast, after weaning, the duration of grooming movements of long displacement directed to the fur, genital area, and body scratching were significantly increased. The findings suggest that early thyroxine treatment may primarily interfere with the neural circuitry that modulate long displacement grooming movements, rather than with the substrates controlling short displacement grooming activities. Thus, the hormone might be acting upon neural modulatory systems of self-grooming having different vulnerability in relation to the level of maturity of the brain circuits underlying each grooming component.

Animals↗
PubMedDate not supplied

Protein malnutrition on suprachiasmatic nucleus cells in rats of three ages.

The effects of prenatal and postnatal protein malnutrition on the major and minor somatic axes of the suprachiasmatic nucleus (SCN) cells of the rat were investigated. Female rats were fed either 6%, 8% or 25% casein diet 5 weeks before mating, during gestation and lactation. After weaning the pups were maintained on the same diet until sacrifice at 30, 90 or 220 days of age. The major and minor axes in fusiform, multipolar and ovoid cells were measured in Nissl-stained SCN slices. Although the 8% diet group displayed significant reductions in fusiform and ovoid cells, the 6% diet group showed the most intense reductions in cell size of the three cell types. In the 6% diet group, cell size was significantly lower at 30 days but the difference with the other nutritional groups ameliorated at 90 days and almost reached control values at 220 days. These data suggest that malnutrition maintained during gestation and postnatal life reduces the somatic size of SCN cells. This alteration may be a morphological substrate underlying sleep and behavioral circadian alterations observed in malnourished rats.

Age Factors↗
PubMedDate not supplied

[Lymphocyte subpopulations and surgery. The role of postoperative parenteral nutrition].

The effects of LCT-based lipid emulsions used in TPN on immune system remains controversial. In this prospective study we research the effects of three types of TPN on T-lymphocyte subsets and NK cells. 21 patients diagnosed because of upper gastrointestinal carcinoma (UGIC), and amenable of curative surgery were included in the study. TPN support was maintained 10 postoperative days at least. All patients received 35 non-proteic Kcal/KG BW/day. Group I (without lipid): received 100% of caloric intake (CI) by glucose. Group II (LCT): received 55% of CI by glucose and 45% by LCT at 20% emulsion. Group III (MCT/LCT): received 55% of CI by glucose and 45% by MCT/LCT at 20% mixture. T-lymphocyte subsets were determined by flow cytometry preoperatively and in first and tenth postoperative days. Our results suggest that patients diagnosed of UGIC present alterations of cellular immunity. These alterations are increased by the age and by surgical act. The changes found are independent of the type of TPN. LCT-based emulsions have similar effects on T-lymphocyte subsets that MCT/LCT-based emulsions.

Aged↗