Scielo RSS <![CDATA[Revista médica de Chile]]> https://scielo.conicyt.cl/rss.php?pid=0034-988719990012&lang=es vol. 127 num. 12 lang. es <![CDATA[SciELO Logo]]> https://scielo.conicyt.cl/img/en/fbpelogp.gif https://scielo.conicyt.cl <![CDATA[Cardiopatía, embarazo y tratamiento anticoagulante]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200001&lng=es&nrm=iso&tlng=es Pregnancy is a hypercoagulable state. Some women with cardiac disease and mechanical valve prosthesis are at increased risk of arterial thromboembolic phenomena. These women are maintained on oral anticoagulants and require effective permanent prophylaxis during pregnancy. The use of oral anticoagulants during pregnancy is controversial because of the risks of embriopathy (Chondrodysplasia punctata) in fetuses who are exposed to coumarin between the 6th and 9th week of gestation, the risk of neurological disorders all through pregnancy, and a higher incidence of abortion and stillbirths. The exact incidence of these complications is unknown. Most of this information comes from North American reports, when much higher mean daily doses of coumarin were administered, and they were probably overemphasised2. Reports from Europe, Asia and our own, show that both embriopathy and central nervous system malformations are probably dose-related and that the risks of abnormality to the fetus are small3-8. The ACC Antithrombotic Consensus (1998) recommends the use of subcutaneous heparin all through pregnancy or until the 13th week of gestation. Heparin does not cross the placenta, however there is a higher risk of maternal bleeding, abortion and stillbirths. With the use of small dose of heparin and of therapeutic heparin doses there is a risk of prosthesis thrombosis. Anticoagulant treatment of patients with prosthetic heart valves during pregnancy remains controversial. Subcutaneous heparin prophylaxis is feasible but the use of well controlled oral anticoagulants appear to offer lower risks of maternal and fetal complications. <![CDATA[Diferencia en peso de nacimiento promedio según tres variables biológicas en recién nacidos normales]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200002&lng=es&nrm=iso&tlng=es Background: The most important determinant of birth weight is gestational age. However, other biological variables may influence this parameter. Aim: To study the influence of maternal parity, height and neonatal gender on the birth weight of normal newborns in a public Hospital of Southern Chile. Material and methods: A computer registry of all deliveries attended in Temuco Hospital between 1993 and 1998 was analyzed. Normal deliveries giving birth to newborns of more than 2,500 g and from women who did not suffer from conditions that could influence birth weight, such as hypertension, undernutrition or smoking, were selected. Results: From 27,736 deliveries, 12,580 were selected for the study. Male newborns with gestational ages from 37 to 42 weeks, had a higher weight than their female counterparts. Multiparous women and those with a height over 154 cm gave birth to newborns with a higher weight than nulliparous women or than those with a height of less than 154 cm. Conclusions: According to these results, birth weight must be corrected by gender and maternal features, to define those newborns that have a low birth weight for their gestational age. <![CDATA[Asociación entre el fenotipo fisura labiopalatina no sindrómica y marcadores de microsatélite ubicados en 4q]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200003&lng=es&nrm=iso&tlng=es Background: Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common craniofacial defect. Association studies have suggested that a clefting locus is located on chromosome 4q at or near two microsatellite markers D4S175 and D4S192. Aim: To test the hypothesis on the possible presence of a clefting locus on chromosome 4q. Material and methods: We carried out an association study on a sample of unrelated NSCLP patients, of their unaffected relatives and in controls. Both probands and relatives were further analyzed depending if they originated from simplex or multiplex families. DNA was analyzed with two PCR markers close to the putative NSCLP locus, dinucleotide repeats D4S175 and D4S192. PCR products were resolved by PAGE and visualized by silver staining. Statistical analysis was performed by means of <FONT FACE=Symbol>c</FONT>2 log ratio. Results: Significant differences between NSCLP and controls were observed when comparing the allele frequency distribution of D4S192 both in the total sample as well as in NSCLP-multiplex and simplex cases. No significant differences for D4S175 were observed in any of the comparisons. Unaffected relatives showed significant differences with controls both for D4S175 and D4S192. Conclusions: Our results support the hypothesis that a NSCLP locus maps on chromosome 4q close to the microsatellite marker D4S192. No differences were observed between NSCLP multiplex and simplex cases versus controls, implying that they do not represent different etiologic entities. The results of the present and previous studies in the same group of patients support the hypothesis that several major interacting genes participate in the etiology of NSCLP. <![CDATA[Prevalencia de mucosa cardial o fúndica y presencia de <I>Helicobacter pylori</I> en la unión de mucosas escamoso-columnar en pacientes con reflujo gastroesofágico crónico patológico sin metaplasia intestinal comparados con controles]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200004&lng=es&nrm=iso&tlng=es Background: The mucosa distal to the endoscopic mucosal change zone can have easily diagnosed early alterations, in patients with chronic gastroesophageal reflux. Aim: To determine the type of mucosa existent in the zone distal to the squamous-columnar junction in patients with chronic gastroesophageal reflux without intestinal metaplasia. Patients and methods: One hundred thirty four controls and 208 patients with chronic gastroesophageal reflux lasting two years were studied. Forty three of these patients had a normal endoscopy, 54 had an erosive esophagitis and 111 had a short columnar epithelium covering the distal esophagus, without intestinal metaplasia. In all subjects, four biopsies were obtained from a zone distal to the squamous-columnar junction and two from the distal gastric antrum. Results: In 59% of control subjects, fundic mucosa was present in the zone distal to the squamous-columnar junction. Cardial mucosa was present in the rest. In patients with chronic gastroesophageal reflux, cardial mucosa was predominant. Helicobacter pylorii infection decreased along with increasing extension of cardial mucosa covering the distal esophagus. Conclusions: In patients with chronic gastroesophageal reflux there is a metaplasia of fundic mucosa towards cardial mucosa. On the other hand, Helicobacter pylorii infection decreases gradually. <![CDATA[Emergencia de resistencia a macrólidos en <I>Streptococcus pyogenes</I>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200005&lng=es&nrm=iso&tlng=es Background: Diseases produced by Streptoccocus pyogenes are still a problem in Chile, as in the rest of the world. It exhibits in vitro susceptibility to different antimicrobials, but penicillin continues to be the treatment of choice. Alternative drugs have been developed for allergic patients, such as erythromycin, new macrolides and cephalosporins. Nevertheless, resistant strains are appearing due to the indiscriminate use of macrolides. Aim: To assess present antimicrobial susceptibility of S Pyogenes strains isolated from chilean patients. Material and Methods: The susceptibility to penicillin, macrolides, clindamycin, cephalotin and vancomycin of 153 S Pyogenes strains, obtained from different health centers of the Metropolitan Region and isolated between 1996 and 1998, was assessed using the Kirby-Bauer method. Agar dilution minimal inhibitory concentration was then determined to macrolide resistant strains. Results: All strains were susceptible to penicillin. There was a 7.2% cross-resistance to macrolides. Conclusions: These results confirm that S Pyogenes resistance to macrolides has increased considerably in the Metropolitan Region of Chile during the last years. <![CDATA[Estrés ocupacional en personal de salud]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200006&lng=es&nrm=iso&tlng=es Background: Occupational stress results from the interaction of multiple risk factors, such as the physical environment, biological function disturbances, work content and organization and diverse psychosocial components. Aim: To study the frequency of symptoms and the main sources of job stress, perceived by professional and non professional health care workers and to compare gender differences. Subjects and methods: A group of specially designed, self-administered, questionnaires adapted by the main author and independently validated, were applied. The results of two symptoms, one work satisfaction, and one job stress scales are reported. Results: One hundred sixteen women and 89 men were studied, 143 are professionals and 62 non professionals (clerical and nurse auxiliaries). Forty percent had symptoms of job stress and 82 subjects were defined as "probable cases", according to the ratings on the symptom scales. There were significant differences in the frequency of symptoms between professionals and non professionals (34.3 and 69.2% respectively). The main differences in symptoms, sources of job stress and dissatisfaction were more closely associated to the occupational level than to gender. Conclusions: A high frequency of job stress symptoms was observed in this sample of health care workers and the risk of occupational stress varies more with the occupational level than with gender. <![CDATA[Fluorosis dental: recuento de <I>Streptococcus mutans</I> en escolares provenientes de la Primera Región de Chile. Estudio longitudinal]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200007&lng=es&nrm=iso&tlng=es Background: High fluorine concentrations in drinking water are associated with a decrease in the amount of salivary S mutants. Taking into account that clinical dental fluorosis can appear with 1.5 ppm of fluorine in the drinking water, fluorine concentration in Mamiña is 2.4 ppm. Aim: To quantify salivary S mutans in school age children from Mamiña, a zone with a high fluorine content in the drinking water, during one year. Material and methods: During 1997 and 1998, dental health was assessed and salivary samples were obtained from 51 children (27 male) aged 10 ± 2 years to quantify S mutans. Results: Most children studied had more than 105 salivary S mutans colony forming units. No changes in the rates of infection or dental health characteristics were observed during the observation year. Conclusions: High fluorine content in the drinking water did not have an effect on salivary S mutans infection in this population. <![CDATA[Estudio anátomo-patológico del disco de la articulación temporomandibular en individuos colombianos]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200008&lng=es&nrm=iso&tlng=es Background: The temporomandibular joint is an oval fibrous plate that completely divides the joint and accommodates irregularities existent in the bone articular surfaces. Aim: To study the frequency of temporomandibular joint disk abnormalities among Colombian subjects. Material and methods: We studied 120 temporomandibular joint disks obtained from fresh cadavers arrived in the Instituto de Medicina Legal, in Cali Colombia. These were analyzed according to subject’s dental status and age. Results: Nineteen percent of disks had small erosions. In 7,5% of disks there were wider erosions or perforations. Twenty six percent of discs were very thin and this alteration was seen mostly in people aged 50 years or older. Conclusions: These results are intermediate between those who claim that disk perforations are rare and those who had shown tile opposite. The loss of dental pieces seems to be a risk factor leading to such disk perforation. <![CDATA[Heparina subcutánea durante el primer trimestre del embarazo en mujeres con prótesis valvulares ardíacas]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200009&lng=es&nrm=iso&tlng=es Background: Oral anticoagulation therapy in pregnant women with prosthetic heart valves is associated with a greater risk of abortion, fetal malformations and thromboembolic complications. Aim: To assess the use of subcutaneous heparin in women with pregnancies of less than 12 weeks as an alternative to oral anticoagulation therapy. Material and methods: Pregnant women were admitted to the hospital and coumarinics were replaced with not fractionated subcutaneous heparin in a dose of 10,000 IU every 12 hours, aiming at prolonging partial thromboplastin time, 2 or 2 1/2 times. During the hospitalization period, women were taught about the heparin injection technique. Coumarinics were restarted after week 13 of pregnancy until 10 days prior to the delivery date in which women were again admitted to the hospital and intravenous heparin was used until the delivery. Results: Between 1991 and 1997, this protocol was used during ten pregnancies in seven women aged 19 to 36 years old. Five had a Starr-Edwards prosthesis, one had a mitral Björk-Shilley prosthesis and one, a double prosthesis (mitral Starr-Machi and aortic St Jude). Subcutaneous heparin was started in the fifth week of pregnancy in 1 case, in the sixth week in seven and in the seventh week in two. There was no maternal mortality and one transient ischemic attack without sequelae. One non compliant patient had a Björk Shilley prosthetic valve dysfunction that required a valve replacement at the twelfth week of pregnancy and she had a spontaneous abortion at week 15. Other patient had a pneumonia at week 37 and gave birth to a stillbirth. There were no fetal malformations. Conclusions: This therapeutic protocol can be used among Chilean patients, but must be restricted to compliant women and a strict surveillance must be maintained. <![CDATA[Enfermedad de los tics (síndrome de Gilles de la Tourette): características clínicas de 70 pacientes]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200010&lng=es&nrm=iso&tlng=es Background: Tourette’s syndrome is a childhood-onset hereditary neurobehavioural disorder believed to occur without geographical restrictions. Although there have been reports of this disorder worldwide just a few are from Latin America. Aim: To report a preliminary experience with a series of 70 patients and to review recent advances in this disorder. Patients and Method: We reviewed patients seen in pediatric and adult neurological clinics in Santiago, Chile, all of whom fulfilled clinical diagnostic criteria for Tourette Syndrome. Results: Seventy patients were studied, 54 males (77.1%) and 16 females (22.8%), their mean age at first evaluation was 13.6 years (range 2-46). The mean age of onset of symptoms was 6.4 (range 2-20), the mean time of follow-up was 3 years. Fifty-eight patients showed simple motor tics (blinking, facial grimacing, shoulder shrugging), whereas dystonic tics like head jerking were seen in 38 patients, torticollis in 6 and oculogyric movements in 2. Complex motor tics like jumping, antics, trunk bending and head shaking were present in 16 subjects. Vocal tics were predominantly of the simple type: sniffing, throat clearing, blowing, and whistling. Complex vocal tics were seen in 12 patients, five cases showed palilalia, 3 echolalia and only six displayed coprolalia (8.5%). Tics were of mild to moderate severity in most patients. Obsessive-compulsive disorder was observed in 22.8% and attention deficit and hyperactivity disorder were present in 35.7%. Forty-five patients (64.2%) had a first degree relative with tics, nine patients (12.8%) had a family history of obsessive-compulsive disorder. The current evidence involving desinhibition of cortico-striatum-thalamic-cortical neuronal circuits in the pathogenesis of this disorder is analyzed. Conclusion: Our report supports the recognized clinical homogeneity and genetical basis of Tourette’s syndrome regardless of geographical region and ethnic origin. <![CDATA[Hepatotoxicidad por amoxicilina/ácido clavulánico: caso clínico]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200011&lng=es&nrm=iso&tlng=es We report a 72 years old diabetic male that, after the use of combined amoxicillin-clavulanic acid, developed pruritus and jaundice. Liver function tests showed serum total bilirubin of 4.3 mg/dL aspartate aminotransferase 140 U/l (normal &lt;35 U/L), alanine aminotransferase 470 U/L (normal &lt;40) and alkaline phosphatases of 400 U/L (normal &lt;100). Serology for hepatitis A, B and C viruses was negative, ERCP showed a normal biliary tree and liver biopsy disclosed a cholestatic hepatitis. Ursodeoxycholic was started to relieve pruritus. Liver function tests improved shortly thereafter, suggesting that this drug may be useful in the treatment of drug induced cholestasis. <![CDATA[Ictericia obstructiva en cáncer de próstata.: Caso clínico]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200012&lng=es&nrm=iso&tlng=es We report a 58 years old male, presenting with malaise, weight loss and jaundice. An abdominal ultrasound showed multiple lymphadenopathies in the hepatic hilus and around the pancreas. Fine needle aspiration of these nodes demonstrated an undifferentiated carcinoma. Prostate specific antigen was over 100 ng/ml and a prostate biopsy demonstrated a high grade carcinoma. The patient was subjected to an orchiectomy and hormone therapy (flutamide). Jaundice subsided and he is well after 3 years of follow up and maintained hormone therapy. <![CDATA[Hipertensión pulmonar e infección por VIH: comunicación de un caso]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200013&lng=es&nrm=iso&tlng=es Pulmonary hypertension associated to HIV infection has been reported in the literature with increased frequency. Apparently, this condition has a faster clinical evolution and a higher mortality than primary pulmonary hypertension. The pathogenic mechanisms of HIV associated pulmonary hypertension and the influence of its treatment on patient’s evolution are not well known. We report a 32 years old homosexual male that developed a severe dyspnea in a period of 2 months. Echocardiogram demonstrated right ventricular dilatation and a systolic pulmonary artery pressure of 86 mm Hg. No other causes for pulmonary hypertension were found. Antiviral therapy and vasodilator treatment with a calcium channel blocker were started and the patient had an important subjective clinical improvement. <![CDATA[Inactivación de genes supresores de tumores en la carcinogénesis del cuello uterino]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200014&lng=es&nrm=iso&tlng=es The importance of inactivation of tumor suppressor genes in the development/progression of carcinomas of the uterine cervix is reviewed. It is well known that HPV-related oncogenes are strongly linked to cervical cancer. However, fewer studies have explored the occurrence of inactivation of tumor suppressor genes in this neoplasia. Genetic deletions affecting tumor suppressor genes are the most common mechanism of inactivation of these genes. Studies using conventional molecular techniques such as restriction fragment length polymorphism (RFLP) and Southern Blot showed low frequency of deletions in cervical carcinomas. Detection of deletions by using RFLP and Southern Blot presents several disadvantages, the most important being the difficulty in analyzing pure tumor cells. More sensitive approaches include tissue microdissection and PCR analysis of microsatellites. Using these approaches, it has been shown that genetic deletions are, in fact, frequent events in cervical cancers, being detected in up to 95% of the cases. Multiple genetic loci are involved, including chromosomes 3p, 5p, 6p and 11q. Deletions are detected even in precursor lesions (cervical intraepithelial neoplasia, CIN). Some deletions have been correlated with prognostic parameters, such as stage, depth of invasion, and vascular space involvement. It is concluded that cervical carcinogenesis, like in other tumors, is a multistep process, characterized by the accumulation of events including activation of oncogenes, as well as inactivation of tumor suppressor genes. <![CDATA[Hantavirus en Chile: revisión y análisis de casos desde 1975]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200015&lng=es&nrm=iso&tlng=es Since the identification of the first case of Hantavirus infection in Chile in 1995, a great advance in the knowledge of the disease natural history has occurred. There is evidence to suppose that the infection by Andes virus in suburban areas of Argentina and Chile, whose natural reservoir is Oligoryzomys longicaudatus, has been present but unidentified for a long time. We describe a serologically proven case occurred in 1975. The clinical presentation of the disease slightly differs from that described for Hantavirus Pulmonary Syndrome (HPS), caused by Sin Nombre virus in the USA. There is a wider range of presentation forms including, besides HPS, mild and asymptomatic cases, a greater proportion of renal involvement and pediatric cases. Therefore the epidemiological scenario would be an endemic disease with fluctuations that follow changes in rodent population and their interactions with humans. <![CDATA[Historia de la genética latinoamericana en el siglo XX]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200016&lng=es&nrm=iso&tlng=es The aim of this historical review is to evaluate the evolution of genetics in the context of Latin American scientific culture, to value foreign influences and to highlight the discoveries and contributions of Latin American geneticists. During the first third of the twentieth century, local naturalists, botanists and physicians understood the chromosomal theory of heredity and Mendelian theory of evolution and begun research and teaching on these new theories and technologies. During the thirties and forties, North American geneticists visited South America and formed development poles on cytogenetics and population genetics in Brazil and Argentina. During the fifties and sixties, human genetics was formally established in Brazil, Argentina and Chile. Genetics teaching became generalized in universities and national Genetics Societies were formed. In 1969, the Latin American Genetics Society was created, unifying the efforts of zoologists, botanists, physicians and anthropologists in an unique Latin American cultural space, organizing 11 meetings between 1972 and 1994. Latin Americans have made a great contribution in genome discovery of animal, vegetable and human species in their territory. They explored the great genetic diversity of the continent, discovering new genes and diseases. The biomedical area had the greatest development. In 1997, there were 130 medical genetics centers, 120 hospitals specialized in congenital malformations, 56 molecular biology centers and 26 molecular genetics centers. At the end of the twentieth century, human genetics is completely integrated to medical sciences in Latin America. <![CDATA[Dobutamina y amrinona en shock séptico]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200017&lng=es&nrm=iso&tlng=es The aim of this historical review is to evaluate the evolution of genetics in the context of Latin American scientific culture, to value foreign influences and to highlight the discoveries and contributions of Latin American geneticists. During the first third of the twentieth century, local naturalists, botanists and physicians understood the chromosomal theory of heredity and Mendelian theory of evolution and begun research and teaching on these new theories and technologies. During the thirties and forties, North American geneticists visited South America and formed development poles on cytogenetics and population genetics in Brazil and Argentina. During the fifties and sixties, human genetics was formally established in Brazil, Argentina and Chile. Genetics teaching became generalized in universities and national Genetics Societies were formed. In 1969, the Latin American Genetics Society was created, unifying the efforts of zoologists, botanists, physicians and anthropologists in an unique Latin American cultural space, organizing 11 meetings between 1972 and 1994. Latin Americans have made a great contribution in genome discovery of animal, vegetable and human species in their territory. They explored the great genetic diversity of the continent, discovering new genes and diseases. The biomedical area had the greatest development. In 1997, there were 130 medical genetics centers, 120 hospitals specialized in congenital malformations, 56 molecular biology centers and 26 molecular genetics centers. At the end of the twentieth century, human genetics is completely integrated to medical sciences in Latin America. https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200018&lng=es&nrm=iso&tlng=es https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98871999001200019&lng=es&nrm=iso&tlng=es