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Biomedical subjects

C Morales

Publications and source records attributed to C Morales.

At least 199 records · Page 11Linked to original sources
PubMed1977

Irregular patterns of actin and myosin filaments in human skeletal muscle cells.

The ultrastructural study of cross sections of normal skeletal muscle cells showed the existence of irregular patterns of actin filaments in connection with the hexagonal pattern of the myosin filaments. The actin filaments surrounding each myosin filament vary in number from 6 to 11. The most frequent relationship is 9 to 1, followed by 10 to 1 and 8 to 1. The hexagonal pattern of actin filaments was observed only in the 6 to 1 arrays; as the actin filaments increase in number, they tend to form different polygons or circles around the myosin filaments. All described patterns may occur in each sarcomere. The actin to myosin filament ratio varies from 3 to 4 within each individual myofibril. The described variability of the actin filaments arrays leads to several difficulties in an explanation of the mechanism of muscular contraction.

Actins↗
PubMed1976

The clinical classification of ceroid-lipofuscinosis. A statistical approach.

A revision of 108 published cases from the last ten years has been made, of patients suffering ceroid-lipofuscinosis, which includes two cases studied in our department. The statistical analysis of the initial symptoms, the age of onset and the disease's duration, permits us to conclude that possibly there exists, within this syndrome, four different forms in accordance with the age of onset. Each one of them has a typical clinical pattern. Our classification was compared with previously existing ones.

Adolescent↗
PubMedDate not supplied

Cerebral abnormalities in congenital myotonic dystrophy.

The brain structure of 14 infants born with congenital myotonic dystrophy at 2 hospitals was evaluated by cranial ultrasonography, and the findings were correlated with clinical and neuropathologic data. Ventricular dilation was diagnosed in 11 infants (78%). Seven infants died during the neonatal period; all had ventricular dilation which remained essentially static. In the ultrasound scans of the 5 infants with ventricular dilation. Of the 7 survivors, 4 had ventricular dilation born at 1 hospital, 4 had widening of the interhemispheric fissure. Macrocephaly, a previously unrecognized finding in congenital myotonic dystrophy, was present in 10 infants (71%), 8 of whom presented with ventricular dilation. None had clinical evidence of increased intracranial pressure. There was no ventricular obstruction in the 4 brains examined pathologically. Histologic examination revealed minor expression of neuronal migrational disturbances in each patient. Macrocephaly together with the ultrasonographic and neuropathologic findings in our patients suggest that these abnormalities may originate in an external hydrocephalus.

Brain↗
PubMedDate not supplied

Preliminary screening of five ethnomedicinal plants of Guatemala.

We performed the Irwin test on some different extracts of the aerial parts of Tridax procumbens L., of the leaves of Neurolaena lobata (L.) R. Br., of the bark and leaves of Byrsonima crassifolia (L.) Kunth. and Gliricidia sepium Jacq. Walp. and of the root and leaves of Petiveria alliacea L. At a dosage of 1.25 g extract/100 g dried plant, the aqueous extracts of bark and leaves of Byrsonima crassifolia (L.) Kunth. and G. sepium Jacq. Walp. showed higher activity: decrease in motor activity, back tonus, reversible parpebral ptosis. catalepsy and strong hypothermia.

Animals↗
PubMedDate not supplied

Identifying opportunities to ask patients about their treatment wishes.

Here is a challenging ethical case study about a women who when faced with multiple complications wondered if she could go on. Without specific information on her wishes, an ethical situation ensued when she became unresponsive with combined cardiac, renal, respiratory, and infective complications from cardiac bypass surgery and chronic COPD. Part I describes this case submitted by DCCN readers and Part 2 provides a case analysis by an ethical consultant with suggestions for nurses in similar situations.

Advance Directives↗
PubMedDate not supplied

Response of testicular macrophages to EDS-induced Leydig cell death.

The response of testicular macrophages to massive Leydig cell death was studied by the administration of the specific Leydig cell cytotoxic ethylene dimethane sulphonate (EDS) to sham-operated (SO), short-term (STHX), and long-term (LTHX) hypophysectomized rats. EDS-killed Leydig cells showed the morphological features of the programmed cell death or apoptosis. A 2-fold increase in the number of macrophages was found on days 1-2 after treatment in both SO and STHX rats, and dead Leydig cells were completely eliminated by day 3 after treatment. Otherwise, in LTHX rats, there was a delay in the increase in the number of macrophages, and EDS-killed Leydig cells remained in the testicular interstitium for several days. These results indicate that the phagocytic capacity of the macrophage population was diminished in hypophysectomized rats, and particularly after long-term hypophysectomy.

Animals↗
PubMedDate not supplied

Response of the testis to gonadotrophin replacement in young hypophysectomized vs. gonadotrophin-releasing hormone antagonist-treated rats.

We have studied the response of atrophic Leydig cells to gonadotrophin replacement in young hypophysectomized (HX) and GnRH antagonist (GnRH-ANT)-treated rats. Hypophysectomy was performed at 28 days of age. Age-matched rats were treated with GnRH-ANT from 28 to 51 days of age. From 45 to 51 days of age, animals were injected with 5 IU recFSH, 10 IU hCG or vehicle. Body and testicular weights, as well as the diameter of the seminiferous tubules were significantly higher in GnRH-ANT-treated than in HX rats. Both recombinant FSH and hCG treatments induced a similar increase in testicular weight and tubule diameter in HX and GnRH-ANT-treated rats. However, hCG treatment induced a significantly higher increase in Leydig cell size in HX (3.2-fold) than in GnRH-ANT-treated (1.4-fold) rats. These results suggest that the response of atrophic Leydig cells to gonadotrophin supplementation was partially inhibited in the presence of GnRH antagonist, whereas Sertoli cell-mediated responses seem not to be affected.

Animals↗
PubMedDate not supplied

Allergic reaction caused by articaine.

We report the case of a 51-year-old woman who had an immediate skin reaction after subcutaneous administration of a local anesthetic (LA) composed of articaine and epinephrine before a dental procedure. The patient subsequently underwent further dental procedures without LA. Skin prick tests performed with commercial LAs (lidocaine, mepivacaine, bupivacaine and articaine) were negative with epinephrine and all LAs except articaine. In 10 healthy controls, skin prick tests with articaine were negative. Subcutaneous challenge test with mepivacaine (0.3 and 0.5 ml) was negative. Provocations with the remaining anesthetics of the amide group were not carried out due to the patient's refusal.

Anesthesia, Dental↗
PubMedDate not supplied

Cytodiagnosis of lymphoid proliferations by fine needle aspiration biopsy. Adjunctive value of flow cytometry.

OBJECTIVE: To determine the accuracy of fine needle aspiration biopsy (FNAB) complemented by flow cytometry (FC) for the diagnosis of reactive and neoplastic lymphoid proliferations and subclassification of malignant lymphomas. STUDY DESIGN: Forty-one FNABs of lymphoid lesions on which FC had been performed were evaluated retrospectively. All cases were correlated with histology or clinical follow-up. RESULTS: Twelve FNABs were diagnosed as reactive. Eleven of the 12 were confirmed as reactive on follow-up. One was a case of posttransplant lymphoproliferative disorder. Twenty-five FNABs diagnosed as lymphoma were confirmed by histology. In 22 of these 25 cases, there was 100% correlation between the subclassification given on FNAB with FC and that given on histology. Two of the remaining cases, which were correctly called follicular center cell lymphoma, showed discrepancies in grading. One case called Hodgkin's disease on FNAB was T-cell lymphoma on histology. Of four FNABs given an inconclusive diagnosis, two were lymphoma on follow-up, and two were reactive. CONCLUSION: FNAB examination, when it includes immunophenotyping by FC, is a useful technique for distinguishing reactive lymphoid proliferations from malignant lymphomas and for the subclassification of lymphomas.

Adolescent↗