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A Linares

Publications and source records attributed to A Linares.

At least 37 records · Page 2Linked to original sources
PubMed1997

Anti-insulin activity in normal newborn cord-blood serum: absence of IgG-mediated insulin binding.

Insulin autoantibodies (IAAs) are present in approximately 60% of type I diabetes patients at onset and are used as predictors for the disease. Although the prevalence of IAAs in the general population has been reported to be <1%, preliminary data have pointed out a higher proportion of IAA positivity in newborn cord-blood serum, and some authors have suggested that they are immunoglobulin G antibodies, resulting from a hypothetical gestational insulitis. To characterize this insulin-binding activity, we analyzed cord-blood sera from 100 healthy newborns, as well as serum from 21 of their mothers at delivery, 179 new-onset type I diabetic patients, and 200 healthy control subjects. IAAs were present in 0.5% of the control subjects and 54% of new-onset type I diabetic patients. On the other hand, 96% of the newborn cord-blood sera showed anti-insulin activity, while it was detected in only 14% of their mothers. No significant differences were observed between cord sera and the general population for islet-cell or anti-GAD autoantibodies. Anti-insulin activity in cord serum was not bound by protein A or protein G, in contrast with type I diabetes-related IAA activity. We conclude that this insulin-binding activity, present in most newborn cord sera and specific to the child, is not IgG mediated. These data, together with the absence of other pancreatic autoimmunity markers in this population, suggest that it is an isolated phenomenon not related to type I diabetes or other pancreatic autoimmune processes and is due to the presence of a cross-reacting molecule in cord blood that has yet to be identified.

Adolescent↗
PubMed1997

A comparison between two induction regimes for the interferon treatment of chronic hepatitis C. Response related factors.

Treatment of chronic hepatitis C with alfa interferon for 6 months achieves sustained responses in 15-25% of the patients. The initial induction with higher doses and the prolongation of treatment can improve the results. A randomized, prospective study was carried out to compare the efficacy of a short term induction schedule of interferon alfa-2b (group A) versus a long term one (group B). 106 patients with chronic hepatitis C were included: 54 received 5 megaunits tiw for 8 weeks and 52 for 16 weeks; afterwards, interferon was reduced to 3 megaunits up to 9 months. The percentage of sustained responses, transient responses and non responses were 18.5%, 24% and 57.4% in group A and 23.1%, 28.8% and 48.1% in group B (NS). The following factors were related to a poor response in the univariate analysis: an increase of serum iron levels, ferritin, Gamma-GT and bilirubin, anti-nuclear antibody positivity, presumed non-parenteral infection, an AST/ALT ratio greater than 0.75, a higher Knodell's index and a greater necrosis and fibrosis score. The multivariate analysis revealed that elevated serum iron and ferritin and anti-nuclear antibody positivity had an independent predictive value related to a non response. Our results appear to suggest that an induction with higher doses and the treatment over nine months are more efficient than the classic schedule. The prolongation of the induction period does not provide additional advantages.

Adolescent↗
PubMed1997

Progressive dysregulation of proliferation during cervical carcinogenesis as measured by MPM-2 antibody staining.

To better characterize the amount and location of loss of proliferation control during cervical carcinogenesis, 44 cervical cone biopsy specimens containing various grades of premalignant and malignant lesions and 12 normal cervix specimens were immunohistochemically examined using MPM-2. This antibody recognizes a phosphorylated epitope on a group of proteins that are preferentially phosphorylated at mitosis. The spatial organization of mitotic figures was determined using a computer-assisted image analysis system. The mitotic figure frequencies/unit of epithelial area were found to increase as the histological type progressed; the numbers of mitoses/square millimeter was 1.7 +/- 0.5 (mean +/- SE) for control normal epithelium (n = 12), 3.1 +/- 1.7 for normal epithelium adjacent to cervical intraepithelial neoplasia (CIN) and cancer (n = 28), 7.9 +/- 1.3 for CIN1 (n = 24), 75.8 +/- 16.3 for CIN2 (n = 11), 127.2 +/- 9.7 for CIN3 (n = 22), 196.9 +/- 33.2 for carcinoma in situ (n = 9), and 156.2 +/- 31.0 for cervical carcinoma (n = 8). The MPM-2 index was higher in high-risk premalignant lesions (i.e., those adjacent to areas of high-grade CIN and carcinoma) than it was in lower risk premalignant lesions (i.e., those with no adjacent higher grade CIN or cervical cancer), even if they exhibited the same histological grade. Moreover, the mean relative distance of the mitotic cells from the basement membrane (i.e., the distance from the basal layer to the surface) also increased as the histological grade progressed. These results suggest that proliferation becomes sequentially dysregulated both quantitatively and spatially during cervical carcinogenesis and that the MPM-2 antibody might be useful as a proliferation biomarker.

Antibodies, Monoclonal↗
PubMed1996

Immunogenicity, safety and protective efficacy of one dose of the rhesus rotavirus vaccine and serotype 1 and 2 human-rhesus rotavirus reassortants in children from Lima, Peru.

In a four cell trial, a single 10(4) plaque-forming unit dose of rhesus rotavirus (RRV) vaccine (serotype G3), a human rotavirus-rhesus rotavirus reassortant vaccine with serotype G1 specificity, a similar vaccine with serotype G2 specificity, or a placebo was administered with buffer orally at 2 months of age to 800 Peruvian infants. Only the RRV vaccine was associated with a febrile response (< 38 degrees C) that occurred in 9% of the infants on day 4 after vaccination. Diarrhea or other side-effects were not associated with administration of vaccine. Vaccine strains were shed by only 12-18% of the infants as determined by examination of a single stool specimen obtained on days 4 or 5 after vaccination. Fifty per cent of vaccines developed an IgA ELISA seroresponse; however, a serotype-specific seroresponse by plaque reduction neutralization was demonstrated in < 20% of the participants against each of the three candidate vaccine strains. Vaccine efficacy was evaluated by twice-weekly home surveillance for diarrheal diseases during 24 months post-immunization. Rotavirus diarrheal episodes were identified by ELISA. Only the RRV vaccine had a significant protective efficacy (29%, p = 0.03, chi-square test) against rotavirus diarrhea. Analysis of vaccine efficacy against rotavirus episodes of any severity in which no other enteropathogen was isolated showed a trend towards higher vaccine efficacy. In addition, a similar trend was observed in rotavirus-only episodes in which there was some degree of dehydration or when health services were utilized. Serotype G1 or G2 rotavirus strains were most prevalent during surveillance. Neither serotype G1 or serotype G2 vaccines were protective against serotype 1 or 2 rotavirus diarrhea, respectively. The serotype G2 vaccine was 84% protective against serotype 1 and 2 dehydrating rotavirus diarrhea in the small numbers of individuals evaluated. We conclude that one dose of 10(4) p.f.u. of the RRV, serotype G1, or serotype G2 rotavirus vaccine failed to induce either an adequate serotype-specific seroresponse or serotype-specific protection in children immunized at 2 months of age. Only the RRV vaccine induced a low level of protection against rotavirus diarrhea mainly of serotype G1 specificity. Future studies need to explore whether higher vaccine dose and/or more than one dose would increase the immunogenicity and efficacy of the rotavirus vaccine, especially in developing countries with a high level of baseline rotavirus antibodies.

Diarrhea, Infantile↗
PubMed1996

Colonoscopic findings in patients with lower gastrointestinal bleeding send to a hospital for their study. Value of clinical data in predicting normal or pathological findings.

BACKGROUND: Lower gastrointestinal bleeding is a highly frequent clinical problem that may reflect serious pathology in the colon. Colonoscopy is generally accepted as the diagnostic procedure of choice. Decisions as to whether to carry out colonoscopy or not, are not well defined. METHODS: 536 colonoscopies, made to discover the cause of lower gastrointestinal bleeding were analyzed and a final 457 included in the study. All of these patients came to the hospital because they had presented at least in one occasion, one episode of rectal bleeding, and were send by the specialist of the zone, in order to achieve a correct diagnosis of its process. In all cases the following associated symptoms were analyzed: the presence of diarrhea, constipation, abdominal pain and rectal mass on examination. The characteristics of lower gastrointestinal bleeding were analyzed in a subset of 150 consecutive patients. RESULTS: Mean age was 59 +/- 16.9 years. 54.5% were male and 45.5% female. The exploration was normal until the cecum in 146 patients (32%). In the remaining 311, the findings were: polyps (25.1%), diverticular disease (24%), neoplasia (12.6%), inflammatory bowel disease (9.4%), unspecific proctitis (2.4%), ischemic colitis (2.4%), angiodysplasia (1.9%), infectious colitis (1.1%), and miscellaneous (0.7%). An age of less than 40 years and the existence of anal pathology were significantly more frequent among patients with a normal examination (p < 0.001), but with a sensitivity of only 66%. No differences were found among patients with disordered bowel frequency or abdominal pain in relation to the colonoscopic findings. Previous presence of a rectal mass when the examination proved abnormal (p=0.06). Intermittent bleeding and the presence of blood in the stools were more frequent in patients with normal examination (p= 0.07 and p< 0.05, respectively). No significant differences in relation to colour, duration of bleeding, or to whether toilet paper was stained with blood were found. CONCLUSIONS: 1) The more frequent endoscopic findings were polyps and diverticular disease. 2) Clinical data are of little value in predicting a normal examination. 3) Total colonoscopy appears to be the first procedure of choice in all patients with lower gastrointestinal bleeding, irrespective of the clinical data and the presence of anal pathology.

Adolescent↗
PubMed1995

Tuberculous peritonitis: diagnostic value of ascitic fluid pH and lactate.

BACKGROUND: The analytical pattern of ascitic fluid in peritoneal tuberculosis is frequently similar to that found in other causes of ascites. The diagnostic value of the ascitic fluid pH and lactate in cases of tuberculous peritonitis has not yet been established. METHODS: Ascitic fluid pH, lactate, total proteins, cell count, lactate dehydrogenase, glucose, and their blood-ascitic gradients were determined in 10 patients with tuberculous peritonitis (group I). These results were compared with those obtained from 40 patients with cirrhotic sterile ascites (group II), 16 patients with spontaneous bacterial peritonitis (group III), and 18 patients with malignant ascites (group IV). RESULTS: A decreased pH and an elevated lactate level in ascitic fluid were found in patients in group I in comparison with those in group II (p < 0.001). No significant differences were found between group I and groups III and IV. The arterial blood-ascitic fluid pH gradient was more than 0.10 (p < 0.001), and the ascitic fluid-serum lactate gradient was greater than 15 mg/dl (p < 0.001) in group I when compared with group II. No significant differences were found between group I and groups III and IV. CONCLUSIONS: Ascitic fluid pH and lactate are useful markers in differentiating tuberculous peritonitis from cirrhotic sterile ascites. However, these variables lack specificity, as they are also decreased and increased, respectively, in cases of malignant ascites and spontaneous bacterial peritonitis.

Adult↗
PubMed1995

Epidemiology of hepatitis D virus infection: changes in the last 14 years.

To calculate the prevalence of hepatitis D virus (HDV) superinfection, antibody to HDV (anti-HD) was tested on admission in 696 hepatitis B virus (HBV) chronic carriers diagnosed between 1979 and 1992. Anti-HD was positive in 67 patients (9.6%), and it was more frequently detected in i.v. drug abusers (IVDA) (59/74, 79.7%) than in non-IVDA (8/622, 1.3%) (p = 0.0001). The prevalence of anti-HD was higher in HBV chronic carriers diagnosed between 1979 and 1985 (33/219, 15.1%) than in those diagnosed from 1986 to 1992 (34/477, 7.1%) (p < 0.001). However, these figures were not different when IVDA were analyzed alone; 29/34 (85%) and 30/40 (75%) (p = 0.4) IVDA diagnosed in both time frames were anti-HD-positive. Four hundred and thirty anti-HD-negative HBV carriers were prospectively followed, and serial determinations of anti-HD were made. Seroconversion to anti-HD was observed in only six patients (1.4%), and again the rate of seroconversion was higher in IVDA (5/10, 50%) than in non-IVDA (1/420, 0.2%) (p < 0.0001). These findings show that IVDA HBV chronic carriers are still an extremely high risk group for HDV superinfection in Spain and that this virus has little penetrance in other epidemiological categories of HBV carriers.

Adult↗
PubMed1995

Screening practices and knowledge, attitudes, and beliefs about cancer among Hispanic and non-Hispanic white women 35 years old or older in Nueces County, Texas.

A telephone survey was conducted among women 35 years old or older in Nueces County, Tex., to assess ethnic differences between Hispanic and non-Hispanic white women in self-reported cancer-screening practices and knowledge, attitudes, and beliefs about cancer and to evaluate the effect of ethnicity as a predictor for screening practices. A total of 233 Hispanic and 332 non-Hispanic white women participated in the survey. Hispanics were younger and had lower educational and income levels. Overall, Hispanics had lower rates than did non-Hispanics of lifetime mammography (65% versus 79%), clinical breast examination (86% versus 96%), monthly performance of breast self-examination (37% versus 49%), and lifetime fecal occult blood testing (36% versus 69%). After control for confounding factors, Hispanics were still less likely to have ever had a clinical breast examination and fecal occult blood test. Our results suggest the need for more culturally sensitive health promotion efforts to improve knowledge about cancer and early detection practices among Hispanic women.

Adult↗
PubMed1994

[A comparative analysis of blood donors with antibodies to the hepatitis C virus, positivity for the hepatitis B surface antigen and hypertransaminasemia in Asturias].

BACKGROUND: A comparative study of the differences with respect to prevalence, epidemiologic risk factors, clinical and analytical status and histologic data of blood donors with different liver diseases detected in the same geographical area and time period was carried out. METHODS: HBsAg or anti-HCV positive blood donors detected in Asturias (Spain) from October 1989-1991, and a third group of 115 consecutive donors with negative viral markers and an increase in ALT, as well as a fourth control group with no alterations were compared with a BMDP statistical program and logistic regression analysis. RESULTS: The prevalence of anti-HCV+ donors was greater than that of those with HBsAg+ in both general donors (0.87% vs 0.28%) as well as in new donors (1.77% vs 1.2%) with a constant incidence of HBsAg+ cases of around 0.16% of the donations with a decrease being observed in the anti-HCV+ (ELISA 1) cases from 0.76% to 0.25%. The mean age was significantly higher among the anti-HCV+ donors with respect to the remaining groups (41 vs 36 years). Likewise, the cases of anti-HCV+ presenting parenteral risk factors, such as intravenous drug addiction, transfusion or surgery were significantly higher, with the latter two having an independent predictive value. Signs or symptoms of liver disease were more frequently detected in the anti-HCV+ (10.8%) vs the HBsAg+ (2.3%) as were an increase in ALT (52.8% vs 12.7%) and histologic signs of chronic hepatitis (36.4% vs 6.9%). CONCLUSIONS: Anti-HCV+ blood donors more frequently present previous parenteral risk factors, signs or symptoms of chronic liver disease, hypertransaminasemia or histologic data of chronic hepatitis, thus its detection in al altruistic blood donor indicates a high probability of chronic subjacent liver disease. This is in contrast to donors with HBsAg+ which do not normally present liver disease and those with hypertransaminasemia with negative viral markers who generally have slight liver lesions.

Adult↗
PubMed1994

Early neonatal sudden death or near death syndrome. An epidemiological study of 29 cases.

Early neonatal sudden death syndrome (SIDS) is a rare but well known disease entity. Between January 1975 and December 1991, 29 full-term newborn infants delivered in our maternity unit and, considered healthy at birth, suffered early SIDS (n = 15) or early apparent life threatening events (ALTE) (n = 14). Data from the whole population of live full-term infants born in our hospital during the past five years have been used as a reference (n = 27,841). The general rate of early SIDS was 0.14 per 1000 (15/107,263). Combining early ALTE cases, the overall rate was 0.27 per 1000 (29/107,263). A postmortem examination was performed for all infants who died (20/29): no cause of death could be determined, and we did not observe a single case with evident sequelae. There were 9 deaths (31%) within the first hour after delivery and 12 deaths occurred in the early morning hours (04:00-08:00; RR = 3.76; p = 0.0008). The lowest incidence was in the spring (RR = 0.21; p = 0.03). There was a tendency for an increased incidence during the weekend and the summer. No influence of sex, maternal age, gestational age, infant weight presentation, delivery, anesthesia or presence of meconium-stained fluid was found. In our opinion, SIDS can take place even during the first hour of life and it is not possible to predict when a baby might be affected. Pediatrically trained caregivers, close observation by the mother during the first few days and resuscitation facilities in maternity wards may be the most important preventive measures to reduce the risk of early SIDS and the consequences of ALTE in the early newborn period.

Age Factors↗
PubMed1994

Delayed childbearing and pregnancy outcome.

This study is to analyze the effect of delayed childbearing on pregnancy outcome among nulliparous women. A hospital-based study was conducted with prospectively collected data from the computerized perinatal data base that includes information about all patients delivered in our Hospital. We studied 17,230 nulliparous women who were > or = 20 years of age with a singleton gestation delivered between 1987 and 1992. We assessed the rates of low birth weight (< 2500 g), preterm delivery (< 37 weeks), small for gestational age, perinatal death (> 500 g and 28 days of life), and selected complications of pregnancy and delivery (ante partum complications, meconium, labor abnormal fetal heart rate, cesarean section, breech presentation, Apgar score, umbilical cord-pH, and rates of neonatal admission). Compared with women aged 20-29 years, women aged > or = 35 years had no significantly higher odds ratio (OR) of low birth weight < 2500 g (OR = 1.3); preterm delivery < 37 weeks (OR = 1.2); small for gestational age (OR = 1.0); and perinatal death (OR = 1.7). In contrast, we found a significantly higher rates of specific antepartal complications (OR = 1.9); cesarean section (OR = 2.5); breech presentation (OR = 1.4); and higher rates of admission to the newborn intensive care unit (OR = 1.4); but excluding infants delivered before 37 weeks of gestation, we found no significantly higher odds ratio of neonatal admission (OR = 1.4). Delayed childbearing is associated with an increased risk of complications of pregnancy and delivery although neonatal outcomes were not appreciably different from those among infants of younger women.

Adult↗
PubMed1993

Utilization of ketone bodies by chick brain and spinal cord during embryonic and postnatal development.

Lipid synthesis from acetoacetate and 3-hydroxybutyrate was studied in chick embryo from 15 to 21 days and in chick neonate from 1 to 21 days. Embryonic spinal cord showed higher ability than brain to incorporate acetoacetate into total lipids, although a sharp decrease was found at hatching. 3-Hydroxybutyrate incorporation into total lipids was also higher in spinal cord than in brain, especially during the embryonic period. Phospholipids were the main lipids formed in both tissues from both precursors. An appreciable percentage of radioactivity was also recovered as free cholesterol, especially during the embryonic phase. The developmental patterns of amino acid synthesis from acetoacetate and 3-hydroxybutyrate were similar in both tissues: a clear increase after hatching was followed by a decrease at day 4 of neonatal life. Acetoacetate was a better substrate for amino acid synthesis than 3-hydroxybutyrate during the embryonic development in both tissues. Oxidation of both precursors to CO2 strongly decreased between 15 and 21 days of embryonic development both in brain and spinal cord.

3-Hydroxybutyric Acid↗
PubMed1993

Changes in ketone body utilization by chick liver, duodenal mucosa and kidney during embryonic and postnatal development.

1. Lipid synthesis from acetoacetate and 3-hydroxybutyrate in chick kidney and duodenal mucosa showed a clear decrease between 15 and 19 days of the embryonic phase, followed by an increase at hatching and a new decrease during the first neonatal period. The hepatic synthesis of lipids presented a different profile: a peak at 19-day-old embryo and a new increase during postnatal development. 2. These changes would be related to those in 3-hydroxybutyrate concentration in chick plasma throughout the perinatal period. 3. Phospholipids were the main kind of lipid formed in the three tissues. An appreciable percentage of radioactivity was also recovered as free cholesterol, especially during the embryonic phase. Triglycerides were also formed from acetoacetate in a high proportion in liver from neonatal animals. 4. Chick kidney showed the maximal ability to incorporate both precursors into amino acids. The peak obtained around hatching time would be related to the availability of the substrates. 5. Ketone body oxidation to CO2 was also maximal in kidney. In this tissue, a drastic decrease was observed during the final embryonic period, followed by a strong increase at day 1 after hatching and a new decrease at 4 days.

3-Hydroxybutyric Acid↗
PubMed1993

Treatment of chronic hepatitis C with recombinant interferon alfa-2b for nine months.

This randomised, controlled trial was designed to assess the response to a nine month course of interferon (IFN) alfa-2b, starting with a higher than usual dose. Forty eight patients received IFN 5 million units (MU) three times a week for eight weeks followed by 3 MU three times weekly for seven months; 25 patients in the control group received no treatment. The overall response to treatment was 68.7%, an improvement over other studies, but the high rate of relapse (85% in patients who responded) suggested that a nine month treatment period was insufficient in most cases. Histological improvement was seen in more than 80% of responders to interferon, including a reduction in inflammatory activity, necrosis, and fibrosis.

Adolescent↗