Search PubMed⌕ Search

Biomedical subjects

F Alvarez

Publications and source records attributed to F Alvarez.

At least 271 records · Page 15Linked to original sources
PubMed1984

Intrauterine contraception with copper and with levonorgestrel: a randomized study of the TCu 380Ag and levonorgestrel 20 mcg/day devices.

First year results of a randomized study of 1509 users of the Copper T380Ag with a silver core or of an IUD releasing 20 mcg day of levonorgestrel are reported. The cumulative gross pregnancy rate for each device was 0.3 per 100 at one year, with more than 490 women having one year of use with each device. The levonorgestrel-releasing device was associated with significantly fewer bleeding days and significantly increased hemoglobin levels when compared with pre-admission values or the one year values observed among users of the TCu380Ag. Terminations attributable to amenorrhea were significantly more frequent among users of the levonorgestrel-releasing device. The TCu 380Ag was associated with increased frequency and severity of dysmenorrhea compared with pre-admission levels or with the steroid-releasing device. Hemoglobin levels were somewhat reduced among users of the TCu 380Ag device. Terminations attributable to pain were, however, not significantly different by device. Continuation rates at the end of the first year were not significantly different by device.

Adolescent↗
PubMed1984

Daily serum choriogonadotropin concentrations in early human gestation.

Fifteen regularly menstruating, healthy women were studied from day 10 of the menstrual cycle to either confirmation of pregnancy or spontaneous menses. Daily blood samples were obtained and serum luteinizing hormone (LH), human chorionic gonadotropin hormone (hCG), 17 beta-estradiol and progesterone were determined by means of specific radioimmunoassay (RIA). Two of the women experienced spontaneous conception with a rise in hCG on 12 and 13 days after LH peak.

Adolescent↗
PubMed1984

Plasma vitamin E levels in children with cholestasis.

Plasma vitamin levels were assayed in 58 children presenting with chronic cholestasis. In the infants who developed cholestasis during the first weeks of life, vitamin E levels dropped below normal values after the age of 4 months. In the older children, vitamin E levels were not correlated with the etiology of cholestasis but with the degree of cholestasis, as expressed by serum bilirubin, serum bile acids, and fat absorption coefficient. We did not find any relationship between vitamin E levels and other biological parameters such as alkaline phosphatases, triglycerides, phospholipids, and cholesterol. These results further support the importance of vitamin E deficiency in chronic cholestasis of infants and children.

Absorption↗
PubMed1983

Levonorgestrel plasma levels during continuous administration with different models of subdermal implants.

Plasma concentrations of levonorgestrel were determined in women using subdermal levonorgestrel implants. One group had 6 Silastic capsules (NORPLANT), one group had 4 and one group had 6 covered Silastic rods for variable lengths of time. Levonorgestrel concentrations remained constant around 0.4 ng/ml up until 6 years of use in the Norplant group. The observation period was shorter for the covered rods; plasma concentrations were, however, constant around 0.55 ng/ml and 0.70 ng/ml for 3.5 years with the 4 rods and 6 covered rods, respectively. The difference in mean levonorgestrel concentrations between the three groups were statistically significant (p less than 0.0005). Plasma levels of levonorgestrel were twice to three times higher in blood obtained from the arm with the implants compared to the levels found in the other arm. The application of a tourniquet for variable periods before blood sampling did not influence the plasma concentrations of levonorgestrel.

Blood Specimen Collection↗
PubMed1983

Portal obstruction in children. I. Clinical investigation and hemorrhage risk.

We examined 108 children with obstruction of the portal vein. Symptoms included splenomegaly and gastrointestinal tract hemorrhage. Obstruction was secondary to portal vein injury in 44 children and was combined with congenital malformations in 17 others. Ultrasonography provided the correct diagnosis in 36 of the 37 children in whom it was performed. Angiography, performed in 101 children, showed that the obstruction extended to the superior mesenteric vein in 14 children and to the entire portal venous system in seven; intrahepatic branches were involved in half the cases. Natural splenorenal shunts were visible in 19 children but were not clearly associated with a lower risk of gastrointestinal tract bleeding; in five of 30 children, cavography displayed abnormalities of the inferior vena cava. Spontaneous gastrointestinal tract hemorrhage occurred in 78 children. Fiberoptic endoscopy showed esophageal varices in 79 of the 81 children studied. The presence of tense varices and congestion of esophageal mucosa clearly augmented the risk of bleeding. These results suggest a simple method of investigation based on ultrasonography for diagnosis and on endoscopy for prognosis. Angiography should be limited to children with a history of gastrointestinal tract bleeding for whom a surgical portosystemic shunt is being considered.

Adolescent↗
PubMed1983

Portal obstruction in children. II. Results of surgical portosystemic shunts.

Seventy-six children with portal vein obstruction underwent surgical portosystemic shunt, for severe gastrointestinal tract bleeding in 64 and for prophylactic purposes in 12. Endoscopy and angiography or both showed shunt patency in 70 children; thrombosis occurred in the remaining six. The mean age at successful shunt surgery was 6 years 10 months. Early postoperative assessment of shunt patency was judged from regression of splenomegaly and thrombocytopenia when splenectomy was not performed; when done, early postoperative ultrasonography correctly indicated the result. Significant regression of endoscopy was most often delayed postoperatively for up to six months. Children with a proved patent shunt did not have any further episodes of gastrointestinal tract bleeding, displayed no clinical signs of encephalopathy, and often exhibited a striking increase in growth velocity. These results strongly support the contention that a portosystemic shunt is the best treatment for portal vein obstruction after the first spontaneous bleeding episode, even in young children.

Adolescent↗
PubMed1983

Hepatitis B virus DNA in children's liver diseases: detection by blot hybridisation in liver and serum.

Molecular hybridisation using cloned hepatitis B virus DNA (HBV DNA) was applied to liver and serum samples from 46 children (39 with liver diseases and seven controls) for detection of HBV DNA sequences, free and integrated into the liver cell genome. HBV DNA integration was observed in 10 children. The young age of some of these cases indicates that such integration can occur early in liver disease and is not related to the duration of viral infection. Thirteen children exhibited serological evidence of active viral multiplication. All but one had free HBV DNA in liver tissue and integrated HBV DNA sequences were found in four cases. Integrated HBV DNA sequences alone were also detected in three children with neither HBV-antigens nor HBV DNA in serum. One had inactive cirrhosis, and the two others, chronic active hepatitis. Consequently DNA hybridisation may be useful for diagnosis, in the absence of serological signs of HBV infection; its specificity was enhanced in the present investigation by negative results in six children with autoimmune chronic active hepatitis. Taken together, the above results imply that HBV-DNA integration can occur in both active and inactive liver disease. Integrated HBV DNA was also observed in the liver of three children with fatal hepatic failure who presented with antibodies to HBsAg and/or to hepatitis B core antigen in the serum. This finding raises the question of the relationship between the host immune factors and the state of HBV DNA.

Adolescent↗
PubMed1982

Latent chronic cholangitis in congenital hepatic fibrosis.

In a five-year-old girl with congenital hepatic fibrosis raised erythrocyte sedimentation rate and serum gammaglobulins were noted for 3 years. Needle liver biopsy showed histological features of cholangitis and Klebsiella oxytoca was cultured from a liver biopsy specimen. Antibiotic treatment resulted in normalization of erythrocyte sedimentation rate and serum gammaglobulins. This suggest that cholangitis can be clinically latent in congenital hepatic fibrosis and should be investigated and treated when unexplained inflammatory signs are present.

Child, Preschool↗
PubMed1982

Calcified cerebral hydatid cyst.

A case of calcified cerebral hydatid cyst recently treated in our neurosurgical service is reported. The frequency of calcified cerebral hydatid cyst (CCHC) is less than 1% of cerebral hydatid cysts. A review of the literature disclosed 13 cases of calcified cerebral hydatid cysts. The clinical presentation and radiological findings are discussed. The present case is, to the best of our knowledge, the first case studied by computerized tomography.

Adult↗
PubMed1982

[HB virus antigens in the liver during chronic hepatitis in children].

An immunoperoxidase study of HBsAg and HBcAg was carried out on liver biopsies of 30 children with chronic hepatitis or idiopathic cirrhosis. Presence of HBsAg and HBcAg occurred only in children who were HBsAg positive in their serum. The number of cytoplasmic HBsAg positive hepatocytes appears higher in children whose liver disease is histologically less severe. The number of hepatocytes with nuclear HBcAg seems directly related to the presence or absence of HBeAg in the serum. Those results are in agreement with previously published observations suggesting that the host's immune response is an important factor of the severity of the liver disease in hepatitis B infections.

Autoimmune Diseases↗
PubMed1982

[Vitamin E and cholestasis in children].

The mechanisms and consequences of Vitamin E deficiency were studied in 12 children presenting with chronic cholestasis. Preliminary results indicate that: (1) Vitamin E serum levels are lowest in children with the long-lasting cholestasis and in children in whom fat malabsorption is deepest. (2) Signs of neurologic dysfunction involving peripheral nerves, cerebellum, eye movements and retina were present in 7 children. (3) In vitro study of RBC showed increased hemolysis with oxidating agents and in physiological saline. Degree of hemolysis was inversely related to the serum level of vitamin E. (4) Increased platelet aggregation was observed in 8 patients; 6 of these also had low levels of serum Vitamin E.

Child↗
PubMed1981

131I rose bengal: its use in the evaluation of infantile jaundice.

One-hundred ten 131I-rose bengal studies (RBI) were performed in infants suspected of having biliary atresia. Fecal RBI excretion of less than 10% was observed in 72 of 73 cases of extrahepatic biliary atresia, but also in 10 of 37 cases of intrahepatic cholestasis of various origins. One-hundred twenty-two RBI tests were performed in children operated on for extrahepatic biliary atresia and 71 tests were performed between postsurgical weeks 3 and 8, and 51 tests were done later. Prognostically, early tests show that fecal RBI excretion of more than 15% was observed in 2 of 34 cases who were later completely jaundice-free and in only 1 of 37 cases where no bile flow restoration occurred.

Bile Ducts↗