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Biomedical subjects

C Navarro

Publications and source records attributed to C Navarro.

At least 19 recordsLinked to original sources
PubMed1999

Neurofibromatosis and early onset of cancers in hMLH1-deficient children.

Hereditary nonpolyposis colon cancer is a common hereditary disorder caused by the germ-line mutations of DNA mismatch repair (MMR) genes, especially hMLH1 and hMSH2. We report here the first identification of human compounds with a homozygous inactivation of a MMR gene. In a typical hereditary nonpolyposis colon cancer family, MMR-deficient children conceived from matings between heterozygotes for a hMLH1 deleterious mutation exhibited clinical features of de novo neurofibromatosis type I and early onset of extracolonic cancers. This observation demonstrates that MMR deficiency is compatible with human development but may lead to mutations during embryogenesis. On the basis of clinical symptoms observed in MMR-deficient children, we speculate that the neurofibromatosis type 1 gene is a preferential target for such alterations.

Adaptor Proteins, Signal Transducing↗
PubMed1998

Subsarcolemmal expression of utrophin in neuromuscular disorders: an immunohistochemical study of 80 cases.

The immunohistochemical expression of utrophin in 80 muscle biopsies from patients with dystrophinopathies and other neuromuscular disorders is reported. All biopsy specimens were routinely studied by a battery of 12 histoenzymatic techniques, and immunohistochemistry was performed for spectrin, three domains of dystrophin and two domains of utrophin. Abnormal utrophin expression was observed in all dystrophinopathic muscles compared with normal controls or biopsy samples from several other muscular diseases. Inflammatory myopathies presented abnormal overexpression of utrophin and an abnormal dystrophin immunolabeling pattern. This overexpression of utrophin appears to be directly related to the decrease in dystrophin. We conclude that the study of utrophin is important for the histological interpretation and differential diagnosis of dystrophin-related muscular disorders.

Adolescent↗
PubMed1998

Embryology of esophageal atresia in the adriamycin rat model.

PURPOSE: The aim of this study was to describe the dysmorphogenetic process leading to esophageal atresia and tracheoesophageal fistula (EA + TEF) in the recently developed Adriamycin model of the malformation. METHODS: Time-mated pregnant rats were given either Adriamycin (1.75 mg/kg intraperitoneally) or saline on days 6 to 9 of gestation, and their embryos recovered on days 12, 12.5, and 13 were serially sectioned in the transversal plane and studied microscopically after H&E and PAS staining. The findings were compared with those of age-matched untreated embryos. RESULTS: All untreated and saline embryos were normal, whereas 49% of Adriamycin embryos had foregut malformations. Tracheoesophageal separation was complete on day 12 in control embryos, whereas 9 of 10 Adriamycin-exposed embryos had a common esophagotrachea with low emergence of the bronchi at that stage. This pattern had evolved into that of a regular EA + TEF in all nine malformed embryos by day 13. On day 12.5, esophagotrachea was found in 6 of 13 and EA + TEF in 5 of 13 embryos. Two had less well-defined malformations. CONCLUSIONS: Esophagotrachea equivalent to complete tracheoesophageal cleft is the first step leading to EA + TEF in this model. The full-blown malformation is finally acquired by partial loss of the posterior wall of the foregut, which tapers-off in the mediastinal mesenchyme and respiratory differentiation of the anterior wall down to the level of bronchial bifurcation, where it constitutes the fistula and the distal esophagus.

Abnormalities, Drug-Induced↗
PubMed1998

Cardiovascular risk factors and educational attainment in Southern Spain: a study of a random sample of 3091 adults.

STUDY OBJECTIVE: To analyze the associations between educational attainment and major cardiovascular disease risk factors in the Murcia Region (Southern Spain). DESIGN: During 1992 we conducted a survey by interview, with multi-stage random sampling, representative of the general adult population. We calculated odds ratios (OR) and trends by logistic regression as a measure of the association between educational levels and cardiovascular risk factors, taking the university level as the reference category. PARTICIPANTS: A total of 1514 men and 1577 women aged between 18 and 65 years was included in the study. Rate of response to the questionnaire was 61%. Seventy-eight percent of the respondents provided a blood sample. A telephone survey on a representative sample of non-respondents (n = 347), showed no statistical differences in the level of studies. MEASUREMENTS: We asked for educational level (highest schooling qualification completed), and according to the WHO MONICA protocol we measured: blood pressure, cigarette smoking, height, weight and total cholesterol, triglycerides and HDL-cholesterol. We also obtained the leisure-time physical activity by a validated questionnaire. MAIN RESULTS: In a context of a low level of schooling, mainly among the older age groups, the prevalence of risk factors except smoking in women is higher in the lower educational levels. Systolic blood pressure tends slightly to increase as schooling level decreases (both genders, p<0.02). Conversely, serum total cholesterol and triglycerides decrease with higher level of schooling in men. The high levels of HDL-cholesterol observed in all educational groups show no trend in both genders. Arterial hypertension in men and women and overweight in women tend to decrease with higher educational attainment. Moreover, higher level of education is associated with vigorous physical exercise in both genders and cigarette smoking in women. We observed the strongest significant magnitude association in nonschooling with hypertension in men (OR: 1.82; 95% CI: 1.15, 2.89), in women (OR: 2.39; 95% CI: 1.05, 5.44), and with overweight in women (OR: 3.22; 95% CI: 1.97, 5.27), meaning that compared to people at the university level, people without schooling showed two to three times higher prevalence of hypertension and overweight (only women). Also non-schooling obtained the lowest significant association with protective physical exercise for coronary heart disease in men (OR: 0.32; 95% CI: 0.18, 0.56) and in women (OR: 0.31; 95% CI: 0.15, 0.62) pointing out that people at the university level of education had three times the prevalence of vigorous physical activity than their non schoolarized counterparts. CONCLUSIONS: After adjusting for environmental factors, in our adult general population, educational attainment is inversely associated with arterial hypertension in both genders and with overweight in women, and directly associated with cigarette smoking in women and with leisure-time physical activity in both genders.

Adolescent↗
PubMed1998

Familial multiple symmetric lipomatosis associated with the A8344G mutation of mitochondrial DNA.

We describe familial multiple symmetric lipomatosis in a pedigree harboring the 8344 mutation in the tRNA(Lys) gene of mitochondrial DNA (mtDNA). The proband showed neuromuscular involvement but lacked the typical manifestations of myoclonic epilepsy and ragged-red fibers disease. The distribution of the mutation was unusual because the proportion of mutated genomes was higher in blood and lipomas than in muscle tissue.

Adult↗
PubMed1998

Molecular genetic analysis of McArdle's disease in Spanish patients.

We analyzed leukocyte DNA of 19 patients from 12 Spanish families with McArdle's disease (myophosphorylase deficiency). In 15 patients, the enzyme defect was documented histochemically in muscle, and in four the diagnosis was based on clinical and laboratory data. Three patients were homozygous and six were heterozygous for the nonsense mutation at codon 49 (R49X). Our findings indicate that the R49X mutation, which is common in English and American patients, is also present in Spanish patients with McArdle's disease, but at a lower frequency.

Adult↗
PubMed1998

Control of understanding in a task involving medical assistance given by telephone.

This paper addresses the control of understanding in a task involving medical assistance given by phone. This situation was described and analyzed in two previous papers with different goals. Here we focus on activity carried out by the operator in charge of emergency calls (injuries, suicides, medical problems,...) in which the operator must control data given by the caller. We assume that the quality of data in the very first message (by the caller) influences the nature of control (by the operator). Methodology for assessing quality of information and type of control is presented. Nature of control is categorized by "validation" or "checking." Quality of information is assessed by an "informational rate" and some actual verbal exchanges illustrate this point. Findings show that control in the course of dialogues is determined by the quality of information sent by the caller initially.

Chi-Square Distribution↗
PubMed1998

Pharmacodynamics and tolerance of two nadroparin formulations (10,250 and 20,500 anti Xa IU x ml(-1)) delivered for 10 days at therapeutic dose.

Venous thromboembolism may be efficiently treated by once-a-day (o.d.) administration of a high dose of low molecular weight heparin (LMWH) instead of administration of the same total dose in two injections a day (b.i.d.). To reduce the volume of the subcutaneous (s.c.) injection, a more concentrated form of the drug is advisable. This study was designed to compare the bioavailability of 2 formulations of nadroparin containing 10,250 and 20,500 anti-Xa IU x ml(-1) respectively. This was an open, randomized, cross-over study where 12 healthy volunteers (age 18-35) were enrolled. They received either 90 anti-Xa IU x kg(-1) b.i.d. of the 10,250 IU preparation (treatment A), or 180 anti-Xa IU x kg(-1) o.d. of the 20,500 IU preparation (treatment B) for 10 days. On day 1, the subjects were sampled between 0 and 12 h (treatment A) or between 0 and 24 h (treatment B). On day 10, they were sampled between 0 and 12 h and between 12 and 24 h (treatment A) or between 0 and 24 h (treatment B). Anti-Xa and anti-IIa activities were determined by specific chromogenic assays. The main result of the study was that the bioavailability of the anti-Xa activity of the 2 nadroparin formulations was equivalent, as shown by the comparison of the AUC(0-12 h) plus AUC(12-24 h) (treatment A) and the AUC(0-24 h) (treatment B), calculated on day 10. This study also allowed a number of interesting observations to be made. 1) Between day 1 and day 10, there was an accumulation of the anti-Xa activity for treatment A but not for treatment B (accumulation factors: 1.6 and 1.1 respectively); 2) On day 10, the AUC(0-12 h) were slightly but significantly lower than the AUC(12-24 h) suggesting a circadian effect for anti-Xa and anti-IIa activities; 3) the clearance of the anti-Xa activity was comparable at the 2-dose regimens, while that of the anti-IIa activity was lower in treatment B than in treatment A, indicating a significant dose effect for the pharmacodynamics of the longer heparin chains; 4) On average, the clearance of the anti-IIa activity was twice as high as that of the anti-Xa activity; 5) For treatment B, significant APTT prolongations were noticed at Tmax (prolongation factor: 1.7 +/- 0.25), in relation with the anti-IIa activity (0.3 +/- 0.1 IU x ml(-1)).

Adolescent↗
PubMed1998

Aging and venous thromboembolism influence the pharmacodynamics of the anti-factor Xa and anti-thrombin activities of a low molecular weight heparin (nadroparin).

Venous thromboembolism may be efficiently treated by one single daily administration of a high dose of low molecular weight heparin (LMWH). The present study investigates if the physiological deterioration of renal function associated with normal aging or the presence of an acute venous thromboembolism influences the pharmacodynamic pattern of the anti-factor Xa and anti-thrombin activities. Three groups of 12 subjects were investigated. The first 2 groups were composed of healthy volunteers differing by age (25 +/- 4 and 65 +/- 3 yrs) and creatinine clearance (114 +/- 15 and 62 +/- 6 ml x min(-1)). The third group was composed of patients hospitalized for deep vein thrombosis, having a mean age of 65 +/- 11 yrs and creatinine clearance of 76 +/- 8 ml x min(-1). Nadroparin was administered subcutaneously once daily at the dose of 180 anti-factor Xa IU.kg(-1) for 6 to 10 days. Serial sampling on day 1 and on the last day of administration (day n) allowed the pharmacodynamic parameters of the anti-factor Xa and anti-thrombin activities to be compared at the beginning and at the end of the treatment. The main findings were the following: (1) After repeated administration, a significant accumulation of the anti-factor Xa activity was observed in the healthy elderly and in the patients but not in the healthy young subjects (accumulation factor: 1.3). There was no evidence of accumulation of anti-thrombin activity; (2) There were significant correlations between the clearance of creatinine and the clearance of the anti-factor Xa activity but not with that of the anti-thrombin activity; (3) In the patients, the clearance of the anti-factor Xa and of the anti-thrombin activities were 1.4 and 2 times higher respectively than those calculated in the healthy elderly; (4) The mean ratio of the of anti-factor Xa and anti-thrombin clearances was close to 2 in the healthy subjects but equal to 5.4 in the patients. These results suggest that the mechanisms involved in the clearance of polysaccharide chains which support the anti-thrombin activity are different from those of the anti-factor Xa activity and that the enhanced binding properties of plasma proteins to unfractionated heparin reported in patients presenting an acute venous thromboembolism also exists for LMWH, predominantly for the anti-thrombin activity.

Adult↗
PubMed1998

[Morphological changes of mitochondrial myopathies].

By means of the modified trichromic method of Gomori, introduced by Engel and Cunningham in 1963 [1], it has been possible to demonstrate the presence of ragged-red fibers (RRF) in the mitochondrial myopathies. At present, to study these disorders in muscle biopsies, one may also use morphological, ultrastructural, histochemical, fluorescent, immunological and molecular biology methods. However, the alterations thus demonstrated in striated muscle are not always present in all these diseases due to mitochondrial alterations. At the same time, the multisystemic nature of these diseases also implies alterations in the central nervous system.

Antibodies, Antinuclear↗
PubMed1997

Germline hMSH2 and hMLH1 gene mutations in incomplete HNPCC families.

Hereditary non-polyposis colon cancer (HNPCC) is a common hereditary disease characterized by a predisposition to an early onset of colorectal cancer. The majority of the HNPCC families carry germline mutations of either hMSH2 or hMLH1 genes, whereas germline mutations of hPMS1 and hPMS2 genes have rarely been observed. Almost all of the germline mutations reported so far concern typical HNPCC families. However, there are families that display aggregations of colon cancer even though they do not fulfil all HNPCC criteria (incomplete HNPCC families) as well as sporadic cases of early onset colon cancers that could be related to germline mutations of these genes. Therefore, we screened germline mutations of hMSH2 and hMLH1 genes in 3 groups of patients from France and Turkey: typical HNPCC (n = 3), incomplete HNPCC (n = 9) and young patients without apparent familial history (n = 7). By in vitro synthesis of protein assay, heteroduplex analysis and direct genomic sequencing, we identified 1 family with hMSH2 mutation and 5 families with hMLH1 mutations. Two of the 3 HNPCC families (66%) displayed hMLH1 germline mutations. Interestingly, 4 of 9 families with incomplete HNPCC (44%) also displayed mutations of hMSH2 or hMLH1 genes. In contrast, no germline mutation of these genes was found in 7 young patients. Our results show that germline mutations of hMSH2 and hMLH1 genes contribute to a significant fraction of familial predisposition to colon cancer cases that do not fulfil all diagnostic criteria of HNPCC.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Prevalence and control of arterial hypertension in the south-east of Spain: a radical but still insufficient improvement.

Stroke mortality rates in Spain are one of the highest in all of Europe. At the same time, the Murcia region (south-east Spain) shows, for both genders, the highest age-adjusted stroke mortality rates in all of Spain. The earliest available hypertension figure estimations for this area go back to 1981, when a high prevalence combined with an almost nonexistent control was detected. One decade later, updated prevalence estimations of hypertension are presented jointly with their degree of control and their association with other risk factors based on the results of a prevalence survey in a random population sample (n = 3,091). Arterial blood pressure was measured following the MONICA protocol, maintaining a tight quality control on between and within-observer variability. As hypertensive was considered any person with systolic blood pressure (SBP) > or = 140 mmHg or with diastolic blood pressure (DBP) > or = 90 mmHg or with antihypertensive pharmacological treatment. Detected prevalence rises to 32.3% (CI 95%: 29.1%-35.5%) among males and to 23.7% (CI 95%: 21.4%-26%) among females, maintaining its level regarding figures observed back in 1981. However, its control has been increased, especially among hypertensive women [from less than 5% in 1981 to 35% (95% CI: 32%-37.8%) at present]. Hypertension is strongly associated to hipercholesterolemia, overweight, obesity and diabetes (p < 0.01). On the contrary, it shows an opposite association with current smoking, higher educational level and leisure time physical activity (p < 0.01). The highest educational level was associated with better hypertension treatment and control. In summary, while hypertension prevalence is stabilized in our population, its control has improved in a measurable but still insufficient way. These results are in accordance with a decreasing trend in stroke mortality registered in the Murcia Region along the last decade.

Adolescent↗
PubMed1997

Prevalence of hepatitis A antibodies in southeastern Spain: a population-based study.

The prevalence of hepatitis A antibodies in the adult population of the Murcia Region (southeast of Spain) was estimated using an anonymous unlinked serosurvey in a population-based sample of 2,203 adults. The overall anti-HAV prevalence was 76.5%. The prevalence increased with age and was higher in individuals living in towns with less than 10,000 inhabitants.

Adolescent↗
PubMed1997

Expression of myogenic regulatory factors (MRFs) in human neuromuscular disorders.

Immunohistochemical studies using antibodies to myogenic regulatory factors (MRFs) Myo D, myogenin, myf-5, and myf-6, and transcription factors c-Fos and c-Jun, were performed on muscle biopsies from patients suffering from Duchenne and Becker muscular dystrophies, polymyositis, and denervation atrophy, to investigate whether expression of these factors occurs during degeneration and regeneration of adult muscle fibres. Strong Myo D, myogenin, myf-5 and myf-6 immunoreactivity was observed in the nuclei of small regenerating fibres and satellite cells, as revealed by double-labelling immunohistochemistry with N-CAM antibodies, in Duchenne and Becker muscular dystrophies and in polymyositis. This suggests that the myogenic programme is activated during regeneration of adult human muscle fibres. In addition, strong myf-6 and c-Jun immunoreactivity was found in the cytoplasm of some necrotic muscle fibres in patients with Duchenne and Becker muscular dystrophies and in patients with polymyositis. The latter findings suggest that strong cytoplasmic expression of myf-6 and c-Jun is related to the process of muscle fibre degeneration that occurs in these conditions. Increased Myo D, myogenin, myf-5 and myf-6 immunoreactivity was not observed in the nuclei of denervated muscle fibres, although strong c-Fos and c-Jun immunoreactivity was seen in the nuclei of denervated muscle fibres; this suggests that denervation triggers the expression of these transcription factors. Taken together, these observations demonstrate that MRFs and c-Fos and c-Jun are selectively expressed in different human muscular disorders.

Adolescent↗
PubMed1997

Human papillomavirus DNA and antibodies to human papillomaviruses 16 E2, L2, and E7 peptides as predictors of survival in patients with squamous cell cervical cancer.

PURPOSE: To assess whether human papillomavirus (HPV) DNA detection in cervical cancer specimens, or antibodies to selected HPV 16 peptides are predictors of tumor recurrence and long-term survival in patients with squamous cell invasive cervical cancer. SUBJECTS AND METHODS: Four hundred seventy-one cases included in two population-based case-control studies underwent follow-up evaluation. The survival and cause of death were ascertained for 410 cases (87%), with a median follow-up time of 4.6 years after diagnosis. HPV DNA was assessed using an L1 polymerase chain reaction (PCR)-based system and Southern hybridization (SH) on scraped cytologic specimens or biopsies. HPV 16 antibodies to E2, L2, and E7 peptides were detected with enzyme-linked immunosorbent assay (ELISA). RESULTS: Clinical stage was the only independent prognostic factor for recurrence or survival. Although seropositivity to HPV 16 E7/3 peptide predicted a twofold excess risk of mortality (adjusted hazards ratio [HRa] = 2.0; 95% confidence interval [CI], 1.2 to 3.3), the association was restricted to stage I (HRa = 6.6; 95% CI, 1.2 to 37.6) and II (HRa = 5.9; 95% CI, 2.1 to 16.5) patients. The presence of HPV DNA (HRa = 0.9; 95% CI, 0.5 to 1.5), different estimates of the HPV viral load and the HPV type identified were not predictors of tumor recurrence or survival. CONCLUSION: The presence of antibodies to HPV 16 E7 proteins is of prognostic value in early-stage cervical cancer. Our results provide strong evidence that detection and typing of HPV DNA in cervical cells or tissues is not a prognostic factor for recurrence or survival.

Adult↗
PubMed1996

Male sexual behavior and human papillomavirus DNA: key risk factors for cervical cancer in Spain.

BACKGROUND: It is now established that certain types of human papillomaviruses (HPVs) are the sexually transmitted agents etiologically linked to cervical cancer. Studies assessing the contribution of the male's sexual behavior and genital HPV DNA status to the risk of development of cervical neoplasia in sexual partners have yielded inconsistent results. PURPOSE: This study evaluates the role of men's sexual behavior and the presence of HPV DNA in the penis on the development of cervical cancer in their sexual partners in Spain, a low-risk area for cervical neoplasia. METHODS: Husbands (n = 633) of women participating in two case-control studies of cervical neoplasia were interviewed to obtain information on lifestyle habits, including sexual practices. Cytologic samples were taken from the distal urethra and the surface of the glans penis of 183 husbands of case women and of 171 husbands of control women. These samples were analyzed by a polymerase chain reaction-based system using a generic probe and 25 type-specific probes for the detection and typing of HPV DNA. Serologic specimens were also obtained and analyzed for antibodies to Chlamydia trachomatis, Treponema pallidum, herpes simplex virus type II, and Neisseria gonorrhoeae. RESULTS: The presence of HPV DNA in the husbands' penis conveyed a fivefold risk of cervical cancer to their wives (adjusted odds ratio [OR] for HPV DNA positivity = 4.9; 95% confidence interval [CI] = 1.9-12.6). The risk of cervical cancer was strongly related to HPV type (adjusted OR for HPV type 16 = 9.0; 95% CI = 1.1-77.5), to the husbands' number of extramarital partners (adjusted OR = 11.0; 95% CI = 3.0-40.0; for > or = 21 women versus one), and to the number of prostitutes as extramarital sexual partners (adjusted OR = 8.0; 95% CI = 2.9-22.2; for > or = 10 women versus none). Presence of antibodies to C. trachomatis (adjusted OR = 2.6; 95% CI = 1.4-4.6) and an early age at first sexual intercourse of the husband (adjusted OR = 3.2; 95% CI = 1.7-5.9; for < or = 15 years versus > or = 21 years) were also associated with cervical neoplasia in the wife. After adjustment for these variables and for the wife's pack-years of smoking, the husband's smoking was moderately associated with cervical cancer in his wife (adjusted OR = 2.5; 95% CI = 1.4-4.4; for > or = 26.2 pack-years versus none). CONCLUSIONS: The study supports the role of men as vectors of the HPV types that are related to cervical cancer. Life-time number of female sexual partners, number of female prostitutes as sexual partners, and detection of HPV DNA in the penis of husbands are all surrogate markers of exposure to HPV during marriage. IMPLICATIONS: Men who report multiple sexual partners or who are carriers of HPV DNA may be vectors of high-risk HPV types and may place their wives at high risk of developing cervical cancer. Prostitutes are an important reservoir of high-risk HPVs.

Carcinoma, Squamous Cell↗