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Biomedical subjects

M A Carrasco

Publications and source records attributed to M A Carrasco.

At least 19 recordsLinked to original sources
PubMed2003

[People with leprosy in Campinas, Brazil: an anthropological perspective].

This article studies the life experiences of people with leprosy and their intra-domiciliary families in Campinas, Brazil, based on an analysis of their representations concerning health, disease, and treatment. Taking their living and working conditions as the background, the study sheds light on the strategies that allow them to adapt to social and family life, to obtain a livelihood, and to establish familiarity with the disease process. The article focuses particularly on the way such individuals deal with the problems of regaining their health, in addition to evaluating governmental and nongovernmental health services.

English Abstract↗
PubMed2001

Calcium transients in 1B5 myotubes lacking ryanodine receptors are related to inositol trisphosphate receptors.

Potassium depolarization of skeletal myotubes evokes slow calcium waves that are unrelated to contraction and involve the cell nucleus (Jaimovich, E., Reyes, R., Liberona, J. L., and Powell, J. A. (2000) Am. J. Physiol. 278, C998-C1010). Studies were done in both the 1B5 (Ry53-/-) murine "dyspedic" myoblast cell line, which does not express any ryanodine receptor isoforms (Moore, R. A., Nguyen, H., Galceran, J., Pessah, I. N., and Allen, P. D. (1998) J. Cell Biol. 140, 843-851), and C(2)C(12) cells, a myoblast cell line that expresses all three isoforms. Although 1B5 cells lack ryanodine binding, they bind tritiated inositol (1,4,5)-trisphosphate. Both type 1 and type 3 inositol trisphosphate receptors were immuno-located in the nuclei of both cell types and were visualized by Western blot analysis. After stimulation with 47 mm K(+), inositol trisphosphate mass raised transiently in both cell types. Both fast calcium increase and slow propagated calcium signals were seen in C(2)C(12) myotubes. However, 1B5 myotubes (as well as ryanodine-treated C(2)C(12) myotubes) displayed only a long-lasting, non-propagating calcium increase, particularly evident in the nuclei. Calcium signals in 1B5 myotubes were almost completely blocked by inhibitors of the inositol trisphosphate pathway: U73122, 2-aminoethoxydiphenyl borate, or xestospongin C. Results support the hypothesis that inositol trisphosphate mediates slow calcium signals in muscle cell ryanodine receptors, having a role in their time course and propagation.

Animals↗
PubMed2001

Ciliary body tumor and cataract: local resection combined with phacoemulsification.

A 57-year-old man developed a ciliary body mass, clinically diagnosed as malignant melanoma of the ciliary body, that produced a cataract in the right eye. Treatment was cataract surgery with sclerouvectomy performed simultaneously. Pathohistologic examination revealed an acquired adenoma of the nonpigmented ciliary epithelium. The clinicopathologic features and treatment of this tumor are discussed.

Adenoma↗
PubMed2001

IP(3) receptor function and localization in myotubes: an unexplored Ca(2+) signaling pathway in skeletal muscle.

We present evidence for an unexplored inositol 1,4,5-trisphosphate-mediated Ca(2+) signaling pathway in skeletal muscle. RT-PCR methods confirm expression of all three known isotypes of the inositol trisphosphate receptor in cultured rodent muscle. Confocal microscopy of cultured mouse muscle, doubly labeled for inositol receptor type 1 and proteins of known distribution, reveals that the receptors are localized to the I band of the sarcoplasmic reticulum, and this staining is continuous with staining of the nuclear envelope region. These results suggest that the receptors are positioned to mediate a slowly propagating Ca(2+) wave that follows the fast Ca(2+) transient upon K(+) depolarization. This slow wave, imaged using fluo-3, resulted in an increase in nucleoplasmic Ca(2+) lasting tens of seconds, but not contraction; the slow wave was blocked by both the inositol trisphosphate receptor inhibitor 2-aminoethoxydiphenyl borate and the phospholipase C inhibitor U-73122. To test the hypothesis that these slow Ca(2+) signals are involved in signal cascades leading to regulation of gene expression, we assayed for early effects of K(+) depolarization on mitogen-activated protein kinases, specifically extracellular-signal related kinases 1 and 2 and the transcription factor cAMP response element-binding protein (CREB). Within 30-60 seconds following depolarization, phosphorylation of both the kinases and CREB was evident and could be inhibited by 2-aminoethoxydiphenyl borate. These results suggest a signaling system mediated by Ca(2+) and inositol trisphosphate that could regulate gene expression in muscle cells.

Actinin↗
PubMed2000

Hydrodissection after nucleus fracture.

We introduce a technique of hydrodissection that reduces capsular bag distension and thus lowers the risk of capsular block syndrome. In 100 consecutive cases in which this method was used for cataract surgery, no complications occurred. Postoperative best corrected visual acuity was better than 20/40 in 96% of patients.

Adolescent↗
PubMed2000

Second intention healing after Mohs micrographic surgery.

BACKGROUND: Although second intention healing has been used for many years in Mohs micrographic surgery, it has lost popularity. This is due to the long process and functional alteration of important anatomical units if certain wound healing factors are not carefully taken into consideration. OBJECTIVE: To review indications, contraindications, complications, advantages, disadvantages, as well as basic concepts of the wound healing process, wound care and antibiotic prophylaxis in the management of open wounds after Mohs surgery. METHODS: A short but comprehensive review of studies published in the literature dealing with second intention healing as a reconstruction alternative option in certain situations. CONCLUSIONS: Second intention healing is a simple and cost-effective method for reconstruction after Mohs micrographic surgery in well-defined cases. It allows adequate tumoral control with good to excellent functional and cosmetic results.

Anti-Bacterial Agents↗
PubMed1997

Ca(2+)-dependent changes of acetylcholine release and IP3 mass in Torpedo cholinergic synaptosomes.

The aim of the present study was to investigate possible changes of inositol 1,4,5-trisphosphate (IP3) mass in Torpedo cholinergic synaptosomes in conditions promoting stimulated acetylcholine (ACh) release. For this purpose, we used a radioreceptor IP3 mass assay and a chemiluminescent method for ACh detection. Torpedo cholinergic synaptosomes have consistent IP3 mass levels under resting conditions. The IP3 mass was neither modified by changes in external Ca2+ nor by a Ca(2+)-free medium containing EGTA. IP3 mass and ACh release, measured in the same conditions and in parallel, were increased by depolarization with high K+ and by the ionophores A-23187 and gramicidin-D in a manner dependent on external Ca2+ emphasizing that Ca2+ entry, independently of the influx mechanism involved, leads to an IP3 increase. The phospholipase C beta inhibitors U-73122 and U-73343 reduced K(+)-stimulated IP3 levels while K(+)-evoked ACh release was almost completely blocked suggesting an additional effect of these drugs on depolarization-neurotransmitter secretion coupling. The effect reported showing an increase of IP3 by agents that stimulate ACh release may suggest a possible link between IP3 metabolism and the neurotransmitter release mechanism. However, such a link is probably not a direct one as implied by the results obtained with the inhibitors of phospholipase C.

Acetylcholine↗
PubMed1997

Changes in IP3 metabolism during skeletal muscle development in vivo and in vitro.

We have investigated whether IP3 metabolism presents particular changes during critical stages of muscle development. With this aim, we have measured IP3 formation through phospholipase C activity, IP3 removal through IP3 5-phosphatase and IP3 3-kinase activities, as well as IP3 mass, during myogenesis in vivo and in vitro. In developing rat skeletal muscle, both IP3 3-kinase and 5-phosphatase activities were relatively constant from embryonary day 15, the earliest age studied to postnatal day 10; 5-phosphatase decreased upon further development. A transient, major increase in phospholipase C activity was evident at embryonary day 18 while a non-significant increase in IP3 mass was detected at this embrionary age. In rat skeletal muscle in primary culture, all enzyme activities as well as the mass of IP3 increased significantly in myotubes compared to myoblasts. Myotubes incubated with calcitonin gene-related peptide, responded with a transient increase in IP3 mass after 2 to 10 sec; the CGRP-induced increase being completely blocked by U-73122, a phospholipase C inhibitor. Furthermore, IP3 mass increased within 1 hr after exposure to differentiating agents of both RCMH cells, a line derived from normal human skeletal muscle, and C2C12 cells. These results indicate that changes in IP3 metabolism can be correlated to critical stages of muscle development and differentiation, suggesting a possible role for IP3 in these processes.

Animals↗
PubMed1997

Bronchiolitis obliterans organizing pneumonia associated with acute Mycoplasma pneumoniae infection.

A patient with bronchiolitis obliterans organizing pneumonia (BOOP) associated with acute Mycoplasma pneumoniae infection is described. Although mycoplasmas have occasionally been associated with bronchiolitis obliterans, to the best of our knowledge, this is the first well-documented case of BOOP associated with M. pneumoniae infection. The diagnosis of BOOP was made by open-lung biopsy after fiberoptic transbronchial biopsy proved nondiagnostic. Corticosteroid therapy was administered and a dramatic improvement was observed; the patient remained without complaints during a 3-year follow-up period.

Acute Disease↗
PubMed1996

Ca(2+)-dependent changes of acetylcholine release and IP3 mass in Torpedo cholinergic synaptosomes.

The aim of the present study was to investigate possible changes of inositol 1,4,5-trisphosphate (IP3) mass in Torpedo cholinergic synaptosomes in conditions promoting stimulated acetylcholine (ACh) release. For this purpose, we used a radioreceptor IP3 mass assay and a chemiluminescent method for ACh detection. Torpedo cholinergic synaptosomes have consistent IP3 mass levels under resting conditions. The IP3 mass was neither modified by changes in external Ca2+ nor by a Ca(2+)-free medium containing EGTA. IP3 mass and ACh release, measured in the same conditions and in parallel, were increased by depolarization with high K+ and by the ionophores A-23/87 and gramicidin-D in a manner dependent on external Ca2+ emphasizing that Ca2+ entry, independently of the influx mechanism involved, leads to an IP3 increase. The phospholipase C beta inhibitors U-73122 and U-73343 reduced K(+)-stimulated IP3 levels while K(+)-evoked ACh release was almost completely blocked suggesting an additional effect of these drugs on depolarization-neurotransmitter secretion coupling. The effect reported showing an increase of IP3 by agents that stimulate ACh release may suggest a possible link between IP3 metabolism and the neurotransmitter release mechanism. However, such a link is probably not a direct one as implied by the results obtained with the inhibitors of phospholipase C.

Acetylcholine↗
PubMed1995

Inositol 1,4,5-trisphosphate 3-kinase activity in frog skeletal muscle.

Frog skeletal muscle contains a kinase activity that phosphorylates inositol 1,4,5-trisphosphate to inositol 1,3,4,5-tetrakisphosphate. The inositol 1,4,5-trisphosphate 3-kinase activity was mainly recovered in the soluble fraction, where it presented a marked dependency on free calcium concentration in the physiological range in the presence of endogenous calmodulin. At pCa 5, where the activity was highest, the soluble 3-kinase activity displayed a Km for inositol 1,4,5-trisphosphate of 1.6 microM and a Vmax value of 25.1 pmol mg-1 min-1. The removal rates of inositol 1,4,5-trisphosphate by 3-kinase and 5-phosphatase activities of the total homogenate under physiological ionic conditions were very similar, suggesting that both routes are equally important in metabolizing inositol 1,4,5-trisphosphate in frog skeletal muscle.

Animals↗
PubMed1994

Characterization and subcellular distribution of G-proteins in highly purified skeletal muscle fractions from rabbit and frog.

The presence of G-proteins in highly purified fractions from frog and rabbit skeletal muscles was analyzed by Bordetella pertussis toxin-catalyzed ADP-ribosylation and by immunoblots. Two B. pertussis toxin substrates were present in transverse tubules and sarcoplasmic reticulum from frog and rabbit skeletal muscle. Immunoblot analysis suggested that the two B. pertussis toxin substrates present in rabbit sarcoplasmic reticulum are possibly alpha i2 and alpha i3, but the corresponding substrates in sarcoplasmic reticulum from frog are still unidentified. Transverse tubules isolated from both rabbit and frog also contained alpha i2 and alpha i3; additionally, beta 35, beta 36, alpha o (weak immunoreactivity), alpha i1 (and/or alpha i3 in frog), alpha s (short form only in frog), and alpha q were found. Sarcoplasmic reticulum from rabbit also contained alpha s (predominantly alpha s short), beta 36, and alpha q. The presence of alpha q in sarcoplasmic reticulum, in addition to transverse tubules, is potentially a very important finding since this G-protein has been described only in plasma membranes so far. Also, this study describes the candidate G-proteins for the control of excitation-contraction coupling in skeletal muscle.

Adenosine Diphosphate Ribose↗
PubMed1993

[The influence of schools of scientific and classical administration on the scientific production of Brazilian nursing].

This paper traces the influence of F. W. Taylor and H. Fayol in the scientific output of brazilian nursing from 1930 to 1980. The scientific output of brazilian nursing is reviewed, looking for work based upon the Scientific and Classical Schools of Administration. The author executes a bibliographic survey based upon two periodicals: Revista Brasileira de Enfermagem and Revista Paulista de Hospitais. A total of 68 articles were selected and studied. Findings have shown that Taylor/Fayol had and still have an important influence on the theoretic foundation of nursing output. The central theme of the texts centers upon "Studies on the Organization of Hospital Nursing Services", and "Time and Motion Studies concerning Nursing Techniques and Activities:. The central preoccupation in these texts refers to productivity and rationality of work, regardless of the fact that the organization of health and nursing work is a human task, referring to the satisfaction of health needs.

Brazil↗
PubMed1993

[The epidemiological situation of Hansen's disease and its contacts in Campinas].

Leprosy is a highly prevalent, endemic disease in this country. Due to its long evolution, it gives rise to an extremely important social issue. This paper analyses the epidemiologic status of Leprosy in the municipality of Campinas. The epidemiologic framework indicates that control of leprosy communicants in Campinas remains inefficient, showing the need for further studies upon these social actors, important links in the epidemiologic sequence of this disease.

Adolescent↗
PubMed1991

Inositol 1,4,5-triphosphate phosphatase activity in membranes isolated from amphibian skeletal muscle [corrected].

The hydrolysis of [3H]inositol 1,4,5-trisphosphate by a soluble fraction and by isolated transverse tubule and sarcoplasmic reticulum membranes from frog skeletal muscle was studied. Transverse tubule membranes displayed rates of hydrolysis several-fold higher than those of sacroplasmic reticulum and soluble fraction; Km and Vmax were 25.2 microM and 44.1 nmol/mg/min, respectively. Transverse tubule membranes sequentially hydrolyzed inositol trisphosphate to inositol bisphosphate, inositol 1-phosphate and inositol, indicating that these membranes have inositol bis- and monophosphatases in addition to inositol trisphosphatase.

Animals↗
PubMed1988

Calcium modulation of phosphoinositide kinases in transverse tubule vesicles from frog skeletal muscle.

Highly purified transverse tubule membranes isolated from frog skeletal muscle phosphorylate phosphatidylinositol to phosphatidylinositol 4-phosphate and phosphatidylinositol (4,5)-bisphosphate. The two phosphorylation reactions have different calcium requirements. Phosphorylation of phosphatidylinositol to phosphatidylinositol 4-phosphate, which takes place in both isolated transverse tubules and sarcoplasmic reticulum membrane, is independent of calcium in a range of concentrations from 10(-9) to 10(-6) M, and is progressively inhibited to 10% of the maximal values by increasing calcium to 10(-4) M or higher (K0.5 = 5 X 10(-6) M). In contrast, phosphorylation of phosphatidylinositol 4-phosphate to phosphatidylinositol (4,5)-bisphosphate, a reaction exclusively present in transverse tubule membranes, is maximal at calcium concentrations higher than 2 X 10(-6) M and decreases to 30% of maximal values at calcium concentrations of 2 X 10(-7) M or lower (K0.5 = 10(-6) M). Unlike frog membranes, transverse tubules from rabbit muscle need exogenous phosphatidylinositol 4-phosphate in order to produce the bisphosphate derivative in the same range of calcium concentrations. Inositol (1,4,5)-trisphosphate has been proposed recently as a chemical messenger in excitation-contraction coupling in skeletal muscle. Calcium regulation of the synthesis of phosphatidylinositol (4,5)-bisphosphate, the membrane-bound precursor of inositol (1,4,5)-trisphosphate, might have physiological implications regarding modulation of excitation-contraction coupling by intracellular calcium levels.

1-Phosphatidylinositol 4-Kinase↗