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Biomedical subjects

H Reyes

Publications and source records attributed to H Reyes.

At least 73 records · Page 4Linked to original sources
PubMed1994

Missile embolization revisited: a rationale for selective management.

Embolization of missiles is an unusual presentation of penetrating trauma. Often the management of these injuries may be quite challenging, and selective management continues to be subject to controversy. We report a case of a bullet embolus to the right ventricle from the internal iliac vein in a 15-year-old boy that was managed with observation. An algorithm for diagnosis and management of this phenomenon mandates exploration of emboli to the aorta and peripheral arteries with repair of the vascular entry site and embolectomy. It also recommends operative intervention for symptomatic venous emboli to the heart and pulmonary circulation. Nonoperative management may be considered in patients with asymptomatic emboli to the right heart or the cerebral and pulmonary circulation.

Adolescent↗
PubMed1993

The Ah receptor nuclear translocator gene (ARNT) is located on q21 of human chromosome 1 and on mouse chromosome 3 near Cf-3.

We have mapped the Ah receptor nuclear translocator (ARNT) gene to a conserved linkage group located on mouse chromosome 3 and human chromosome 1. EcoRI-digested DNA from a panel of 17 human x mouse somatic cell hybrids was probed with a cDNA fragment of the human ARNT gene. Six of the 17 independent mouse x human hybrids were positive for human bands. Human chromosome 1 showed complete cosegregation with the gene, whereas discordant segregation was observed for all other human chromosomes. The human gene was localized to 1q21 by using DNA from mouse x human hybrid clones that retain translocations involving human chromosome 1, by segregation analysis in nine informative CEPH families, and by in situ hybridization. The mouse homologue was mapped to mouse chromosome 3 using a panel of 16 hamster x mouse somatic cell hybrids. Six of 16 mouse x hamster hybrids were positive for mouse bands, showing complete concordance with mouse chromosome 3. The mouse Arnt gene was regionally mapped on chromosome 3, using linkage analysis in an interspecific backcross. The results indicate that the mouse gene resides about 40 cM from the centromere and about 10 cM proximal to Cf-3, the gene for tissue factor.

Animals↗
PubMed1993

Intrahepatic cholestasis of pregnancy: an estrogen-related disease.

In the recent years new avenues have been opened in the treatment of ICP, a complex disorder that seems to represent a maladaptation of some young and otherwise healthy women, to estrogens or other sex hormones. New drugs have been shown capable of providing promising therapeutic effects either on pruritus, the main distressing symptoms of cholestasis (such as epomediol, silymarin) or both on pruritus and some biochemical abnormalities (such as UDCA). Future clinical and experimental studies should provide better insight into the pathogenesis of cholestasis, the mechanisms of bile formation and secretion, and the metabolism of estrogens and other sex hormones and their alteration relationship to cholestasis, a disorder that is highly prevalent in humans.

Animals↗
PubMed1993

Investigation on the potential role of the Ah receptor nuclear translocator protein in vitamin D receptor action.

The Ah receptor nuclear translocator protein (ARNT) is required for binding of the Ah (dioxin) receptor to the xenobiotic responsive element (XRE), and is a structural component of the XRE-binding form of the Ah receptor. The vitamin D receptor requires an accessory protein for binding to the vitamin D responsive element (VDRE) in the osteocalcin gene. Since the vitamin D receptor has similarities to the Ah receptor, we investigated whether ARNT is also required for vitamin D receptor activity. Two lines of evidence demonstrate that ARNT is not required for vitamin D receptor activity, and therefore does not correspond to the vitamin D receptor accessory protein: i) Antibodies to ARNT have no effect on binding of the vitamin D receptor to the VDRE. ii) c4, a mutant of Hepa-1 cells that is defective in ARNT activity, and in which binding of the Ah receptor to the XRE does not occur, possesses a vitamin D receptor with full activity for binding the VDRE.

Animals↗
PubMed1993

[Message from editors to authors: review articles. How can the scientific and educational results be improved?].

Most biomedical journals include review articles that pretend to provide the readers with an updated, synthetic and critical appraisal of some important topic. These articles are usually written by experts in the topics reviewed. There are no conventional or universally accepted requisites for the formal organization of contents in a review article. This is in contrast with other kinds of original articles. Therefore, to guide the authors on how to improve the review articles to be submitted to Revista Medica de Chile, some recommendations are proposed. These recommendations were based in the editors' experience and in other pertinent publications: 1) The scope and purpose of the review article should be established in the introductory paragraphs; 2) The methodology used in the selection of the literature reviewed and the time span covered by the search, should also be specified; 3) The author of the review article should systematically appraise the validity of the methods employed in the papers reviewed. A similar attitude should be observed with regards to the results, discussions and conclusions. The limitations and inconsistencies found should be pointed out; 4) The author of the review article should state his (her) own conclusions, identifying the solid as well as the weakly established facts; 5) Whenever feasible, a proposal of future lines of research envisioned after reviewing the literature, is commendable; 6) The literary style of the article should be kept as interesting as possible, to motivate the prospective readers; 7) The scope of the specific journal where the author intends to submit the review article, should always be kept in mind.

Publishing↗
PubMed1993

[Congenital hepatic fibrosis: an uncommon cause of portal hypertension].

Congenital hepatic fibrosis is an autosomic recessive disease, manifested in children or in young adults by hematemesis due to rupture of esophageal varices. Bacterial cholangitis may occur in some patients. Early diagnosis and treatment with portosystemic anastomosis and/or antibiotics may lead to a long survival with a good quality of life. Diagnosis requires histologic confirmation: normal hepatic lobules are surrounded by broad fibrous bands, and an increased number of bile ducts is usually seen in the portal tracts. Liver function remains well preserved. This report consists of 3 patients: a 17-year-old woman, a 10-year-old boy and a 24-year-old woman who developed severe upper GI bleeding due to ruptured esophageal varices. The first two patients were successfully operated on using the Sugiura technique for portal decompression. Their current survival after surgery is 3 and 9 years, respectively, with normal physical examination and liver function tests. The third patient died shortly after admission, due to the concurrence of a severe suppurative cholangitis.

Adolescent↗
PubMed1993

[The verbal autopsy: a tool for the study of mortality in children].

The verbal autopsy (VA) is a technique that has been used since 1931, but it wasn't until the last decade that it has been more widely used by different investigators to study mortality both in infancy/childhood and adulthood. The VA consists of an interview directed to a care-giver (usually the mother) close to the deceased subject, and its objective is to disclose information about the cause of death. The VA has been particularly useful in those places where a reliable record of mortality is unavailable or nonexisting. This paper describes the assumptions on which the VA is based, and highlights its most important methodological aspects. Lastly, we stress the use of the VA as an useful too to assess the process associated with mortality, including the family's decision-making process to look for medical care as well as the response and characteristics of the medical care system. In this respect, we point out to the usefulness of the VA as an interface between epidemiology and ethnography, and stress its potential impact as a tool to learn more about the process of health-seeking behaviors, from the points of view of mothers and physicians.

Autopsy↗
PubMed1993

[The verbal autopsy on children with a respiratory infection and acute diarrhea. An analysis of the disease-care-death process].

The study focuses on children between 72 hours and five years of age who died of acute respiratory infection (ARI) or acute diarrhea (AD) in the State of Tlaxcala. Peer Review Mortality Committee of the State contributed with the staff to the deaths analysis. Cases were included only when diagnosis was confirmed by verbal autopsy (VA). One hundred and thirty two cases were included (98 corresponding to ARI deaths and 34 to AD). The process related to medical care-seeking behaviors and prescribing practices by private and non-private physicians was analyzed through the VA. During the study period, 60% of children with ARI and 58.9% of children with AD died at home. More than 80% of these children had received medical care within three days preceding their death, and 50% of them had been seen by a physician within 12 hours prior to their death. Most of these visits were to a private doctor (71% for ARI and 86% for AD). Forty seven percent of treatments prescribed for ARI were judged to be wrong, either because of a bad choice of antibiotic or because the physician did not prescribe an antibiotic when the patient required it. Similarly, 65% of treatments for AD were considered erroneous, either due to the use of an antibiotic which was not justified or due to the lack of oral rehydration therapy when it was needed. Additionally, late referral to a hospital was considered as having direct influence at the death in half of the consultation. Families were too late in demanding medical care or demanded no care at all in 21.9% of cases of ARI and in 6.1% of cases of AD. We have found the VA to be useful in identifying problems related to the process of health-seeking behaviors and medical care. Our results suggest interventions that may lower the high mortality rates in Tlaxcala, such as training workshops directed to institutional and private physicians, and the implementation of top-of-line treatment centers where high-risk patients can be referred and also the health care workers can learn the correct treatment of both diseases. Future studies should focus on the identification of alarm signs and risk factors that may help to lower mortality due to ARI or AD, when recognized and treated at early stages.

Acute Disease↗
PubMed1992

Identification of the Ah receptor nuclear translocator protein (Arnt) as a component of the DNA binding form of the Ah receptor.

The Ah (dioxin) receptor binds a number of widely disseminated environmental pollutants, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and polycyclic aromatic hydrocarbons, and mediates their carcinogenic effects. The ligand-bound receptor activates Cyp 1a1 gene transcription through interaction with specific DNA sequences, termed xenobiotic responsive elements (XREs). The Ah receptor nuclear translocator protein (Arnt) is required for Ah receptor function. Arnt is now shown to be a structural component of the XRE binding form of the Ah receptor. Furthermore, Arnt and the ligand-binding subunit of the receptor were extracted as a complex from the nuclei of cells treated with ligand. Arnt contains a basic helix-loop-helix motif, which may be responsible for interacting with both the XRE and the ligand-binding subunit.

Animals↗
PubMed1992

Effects of ursodeoxycholic acid in patients with intrahepatic cholestasis of pregnancy.

The efficacy and safety of ursodeoxycholic acid in the treatment of intrahepatic cholestasis of pregnancy was investigated in an open pilot study. Five patients received 1 gm/day of ursodeoxycholic acid during 20 days and another three patients received two identical periods of treatment separated by a 14-day interval free of the drug. Pruritus and serum levels of total bile salts and glutamic-pyruvic transaminase improved significantly during treatment with ursodeoxycholic acid. In the three patients who received two periods of treatment with ursodeoxycholic acid, pruritus and the laboratory alterations relapsed in the second week after the drug was discontinued, but they improved again when ursodeoxycholic acid was readministered. No adverse reactions were detected in the mothers or in their babies. All newborns were thriving normally during a follow-up period that lasted 5 mo after delivery. It is concluded that UDCA appears to be safe when administered in late pregnancy; its promising efficacy in the treatment of intrahepatic cholestasis of pregnancy should now be confirmed in controlled clinical trials.

Adult↗
PubMed1992

High-dose vitamin C therapy for extensive deep dermal burns.

We studied the haemodynamic effects of antioxidant therapy with high-dose vitamin C administration (170 mg/kg/24 h) in guinea-pigs with 70 per cent body surface area deep dermal burns. The animals were divided into three groups of six animals each. Group 1 was resuscitated with Ringer's lactate solution according to the Parkland formula; group 2 with 25 per cent of the Parkland formula with vitamin C; and group 3 with 25 per cent of the Parkland formula without vitamin C. There were no significant differences in heart rates or in blood pressures between the groups throughout the 24-h study period. Group 3 showed significantly higher haematocrit values at 3 h postburn and thereafter as compared with those of group 2. The cardiac output values of group 2 were significantly higher than those of group 3, but equivalent to those of group 1. The water content of the burned skin in group 2 was significantly lower than that in the other groups, indicating that increased postburn capillary permeability was minimized by the administration of vitamin C. With adjuvant high-dose vitamin C administration, we were able to reduce the 24-h resuscitation fluid volume from 4 ml/kg/per cent burn to 1 ml/kg/per cent burn, while maintaining adequate cardiac output.

Animals↗
PubMed1992

[Symptomatic effect of epomediol in patients with cholestasis of pregnancy].

Epomediol is a terpenoid that prevents and reverses cholestasis induced by ethinylestradiol in the rat, apparently by improving liver cell membrane fluidity. Assuming that the pathogenesis of intrahepatic cholestasis of pregnancy (ICP) is related with increased estrogen levels, we studied the effects of epomediol in this disease. Patients hospitalized due to ICP received epomediol 900 mg/day (n = 7), or 1,200 mg/day (n = 4) orally, during 15 days. Biochemical parameters of liver dysfunction (serum bilirubin, bile salts, aminotransferase, alkaline phosphatases) were not modified during nor after epomediol administration. The severity of pruritus was significantly reduced in comparison to pretreatment status, with both doses of epomediol. A greater amelioration of pruritus was observed in patients treated with epomediol 1,200 mg/day than in patients who received 900 mg/day (to 20.7 +/- 6.2, as percent of pre-treatment severity score, versus 48.8 +/- 7.5 respectively; p < 0.05). After epomediol administration was stopped, pruritus relapsed in 6 patients; 3 of them had received the higher drug dose. After delivery, pruritus vanished and liver function tests returned to normal, in all patients. No adverse effects attributable to the drug were observed in the mothers or in their babies. The beneficial effect of epomediol on pruritus in patients with ICP appeared greater in this study than that observed recently in similar patients who received a placebo.

Bile Acids and Salts↗
PubMed1992

[Can we improve primary adult medical care?].

In Chile, primary medical care of adult patients is delivered mostly by young physicians, who work with little or insufficient interaction with their referral centers and with the main teaching hospitals. These physicians have no defined expectancies of a professional career in the field of primary care and they generally recent the lack of a programmed post-graduate education. After 3 to 5 years as general practitioners, some of them may have access to a formal teaching program to become specialists in internal medicine but, as in many other countries, it usually becomes a transit stage leading them to a subspecialty. This position paper adopted most of the proposals raised in a recent meeting, with the participation of universities, scientific and medical organizations, and the Ministry of Health, and modifies some of them. Because financial limitations may hinder the possibility of residency training programs in primary care internal medicine (as established in the USA), primary care of adults is proposed to be organized as a basic medical specialty, with formal teaching activities designed, delivered or supervised by the universities and medical scientific societies, and given as "credits" to be taken along 3 to 5 years. Simultaneously, outpatient care facilities should be improved, in the hospitals and in community units, allowing them to be used in under-graduate and post-graduate teaching programs. General practitioners, focused in adult patients, would receive a new professional status with the stimulus of a specific program of continuing medical education.

Adult↗
PubMed1992

The spectrum of liver and gastrointestinal disease seen in cholestasis of pregnancy.

A mild form of intrahepatic cholestasis is an infrequent complication of pregnancy, with a spontaneous cure almost immediately after delivery and that often recurs in future pregnancies. Pruritus alters maternal well-being, and a subclinical steatorrhea may impair the patient's nutritional status; otherwise, it is a mild disease in the mother, and no maternal mortality has been attributed to it. In contrast, cholestasis of pregnancy is often identified as a risk of increased perinatal morbidity and mortality. The cause of cholestasis of pregnancy is unknown. A hereditary predisposition seems to induce in the maternal liver an abnormal reaction to female sex hormones, but some still unidentified environmental (possibly dietary) factor could also be involved in the pathogenesis of the disease. Pruritus, but not the biochemical alterations, can be alleviated by the use of cholestyramine, silymarin, or epomediol. Ursodeoxycholic acid has been beneficial in pruritus and in liver function tests; an improvement in fetal prognosis should be evaluated in future controlled studies.

Cholestasis, Intrahepatic↗