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Biomedical subjects

M Alonso

Publications and source records attributed to M Alonso.

At least 73 records · Page 4Linked to original sources
PubMed2000

Relationships between bilateral asymmetry and tonic immobility reaction or heterophil to lymphocyte ratio in five breeds of chickens.

Bilateral asymmetry of several morphological traits, tonic immobility reaction, and leucocyte ratio were studied in hens and cocks from four Spanish breeds of chickens (Castellana, Buff Prat, Red Villafranquina, and Barred Red Vasca) and an F2 cross between Castellana and Buff Prat (C x BP - F2). Any two or all three types of bilateral asymmetry (fluctuating asymmetry, directional asymmetry, and antisymmetry) occurred together for the same trait in the different breeds. There was a significant difference in relative asymmetry among breeds (P < 0.05) for feather and spur lengths in males, and considerable negative heterosis for relative asymmetry of leg and wing lengths in C x BP - F2 males (-38 and -12%, respectively). The degree of relative asymmetry varied among traits and was between 3 and 12 times greater for spur length in males and for wing bay area in Villafranquina males. There were significant differences among breeds (P < 0.05) for tonic immobility duration. The duration of tonic immobility was positively associated with the mean relative asymmetry of all traits in females from the Villafranquina breed (r = 0.32; P < 0.05), but this finding was not consistent across the different breeds. No significant difference was found among breeds in terms of heterophil to lymphocyte ratio. Although there was no significant association between mean relative asymmetry of all traits and heterophil to lymphocyte ratio, males from the Villafranquina breed had a positive and significant relationship between relative asymmetry for wing bay area and leucocyte ratio (r = 0.34; P < 0.05). These results suggest that relative asymmetry measures did not provide a general tool to assess fear or stress susceptibility.

Animals↗
PubMed2000

Preferential inactivation of the p53 tumor suppressor pathway and lack of EGFR amplification distinguish de novo high grade pediatric astrocytomas from de novo adult astrocytomas.

Classification of high grade astrocytomas of children into genetic subtypes similar to the adult remains to be defined. Here we report an extensive characterization of 29 high grade pediatric astrocytomas, 7 WHO grade III and 22 WHO grade IV, for genetic alterations frequently observed in high grade adult astrocytomas occurring in either the p53/MDM2/p14ARF or Rb/CDK4/p16INK4a tumor suppressor pathways. In addition, we have assessed the contribution of EGFR overexpression and amplification and LOH for chromosome 10, two genetic alterations commonly associated with the development of de novo adult glioblastoma for their roles in the development of de novo astrocytomas of childhood. Our results suggest two major differences in the genetic pathway(s) leading to the formation of de novo high grade astrocytomas in children compared with those of the adult. Our findings show preferential inactivation of the p53 tumor suppressor pathway in >95% of pediatric astrocytomas versus inactivation of the Rb tumor suppressor pathway in <25% of the same tumors. In addition, de novo high grade pediatric astrocytomas lack amplification of the EGFR gene compared with EGFR amplification in one-third of adult glioblastomas. Since drug treatments and gene therapy strategies exploit specific genetic alterations in tumor cells, our findings have important implications for the future development of treatments for high grade pediatric astrocytomas.

Adolescent↗
PubMed2000

Setting health priorities in a Swiss canton: what do different methods tell us?

STUDY OBJECTIVE: Despite excellent mortality indicators, there is clear evidence that the health status of the population of Geneva could be improved if more attention and resources were devoted to prevention strategies. To identify a set of robust health priorities an original approach was used triangulating results between three methods. METHODS: The study calculated potential years of life lost, disability adjusted years of life lost, and conducted a Delphi survey to gather the opinion of health professionals and the general public. MAIN RESULTS: Several health conditions were unanimously selected by all three methods as top priorities: cardiovascular diseases, AIDS, respiratory cancer, breast cancer for women, suicide and traffic accidents. In addition, two determinants-alcohol abuse and tobacco abuse-for which a clear conceptual link could be established between all methods were chosen. Connections between priorities identified through the DALY and the Delphi method lead to further inclusion of chronic back pain and depression. Some issues solely identified through the Delphi survey were included as they were consistently considered important by professionals and the lay public alike-violence in the family, unemployment, social exclusion. CONCLUSIONS: These results indicate that health priorities, and by extension health care priorities, would benefit from using a mix of quantitative and qualitative research methods. The triangulation of results allows for a broader perspective and makes results more acceptable.

Attitude↗
PubMed2000

High prevalence of the polycystic ovary syndrome and hirsutism in women with type 1 diabetes mellitus.

The current recommendation for strict metabolic control of type 1 diabetes mellitus requires the administration of supraphysiological doses of insulin, which might result in insulin-mediated stimulation of androgen synthesis, as occurs in insulin-resistant states. At present, the prevalence of hyperandrogenic disorders in women with type 1 diabetes mellitus is unknown. Eighty-five women with type 1 diabetes mellitus were evaluated for symptoms and signs of hyperandrogenism. In 68 of the patients, several serum androgen and hormone concentrations were measured. The polycystic ovary syndrome (PCOS) was defined by the presence of menstrual dysfunction, together with clinical and/or biochemical evidence of hyperandrogenism, and exclusion of other etiologies. Eighteen healthy women, menstruating regularly, served as controls for the androgenic profiles. Thirty-three patients (38.8%) presented hyperandrogenic disorders (16 had PCOS, and 17 had hirsutism without menstrual dysfunction). Type 1 diabetic patients with PCOS presented increased serum total and free testosterone concentrations, and serum androstenedione levels, but had normal serum sex hormone-binding globulin and dehydroepiandrosterone-sulfate levels. Hirsute type 1 diabetic women without menstrual dysfunction presented normal serum androgen levels. There were no significant differences between hyperandrogenic and nonhyperandrogenic type 1 diabetes mellitus women in clinical variables such as the duration of diabetes, age at diagnosis of diabetes, conventional or intensive insulin therapy, mean daily insulin dosage, or metabolic control. In conclusion, women with type 1 diabetes mellitus have a high prevalence of hyperandrogenic disorders, including PCOS and hirsutism.

Adult↗
PubMed2000

[Obstructive myocardiopathic hypertrophy and sequential atrioventricular stimulation. Immediate results and long term follow-up. Seven years experience].

BACKGROUND: Sequential pacing as a primary treatment for patients with severe hypertrophic obstructive cardiomyopathy is still under controversy. In this study we sought to evaluate the effects of pacing on left ventricular systolic and diastolic function, its repercussion on pathophysiology and the possible changes in clinical evolution and functional class in patients who didn't respond to medical therapy. PATIENTS AND METHODS: Thirty-four patients with severe hypertrophic obstructive cardiomyopathy in functional class III-IV underwent evaluation. The mean age was 64 +/- 11 years. Sixty-two per cent were over 65. The study protocol included Holter monitoring, baseline echo-Doppler, during pacing, at 6 months and at the end of follow-up, and a complete catheterization and coronary angiography. Mean follow-up time was 36 +/- 20 month (range 6-74). In four patients sequential pacing was ineffective and the protocol had to be discontinued. Thirty patients received a permanent dual-chamber pacemaker and systolic and diastolic function were evaluated by hemodynamic, angiographic and eco-Doppler studies. RESULTS: Long-term stimulation reduced the subaortic gradient from 95 +/- 38 to 39 +/- 28 mmHg (p < 0.001), left ventricular systolic pressure from 207 +/- 38 to 164 +/- 30 mmHg (p < 0.001) and left ventricular end-diastolic pressure from 23 +/- 7 to 14 +/- 5 mmHg (p < 0.001), pulmonary capillary wedge pressure from 19 +/- 7 to 14 +/- 5 mmHg (p < 0.001), ejection fraction from 79 +/- 6 to 71 +/- 6% (p < 0.001) and mitral insufficiency. Diastolic function improved with an increase in early filling from 39 +/- 11 to 52 +/- 10% (p < 0.001) and E/A relation from 0.93 +/- 0.4 to 1.6 +/- 0.8 (p < 0.001), and a reduction in late filling from the left ventricle from 36 +/- 10% to 24 +/- 10% (p < 0.001). The speed of the E wave increased from 0.83 +/- 0.3 to 0.92 +/- 0.3 (p < 0.001) and we observed a reduction of the A wave from 93 +/- 0.3 to 0.66 +/- 0.2 (p < 0.001), pressure-half time from 95 +/- 34 to 66 +/- 19 ms (p < 0.001) and we observed deceleration time from 320 +/- 90 to 221 +/- 57 (p < 0.01). All patients have improved their functional class, allowing a reduction in pharmacological therapy. Two exitus of cardiological origin occurred. CONCLUSIONS: Sequential AV pacing in selected patients with severe hypertrophic obstructive cardiomyopathy can reduce subaortic gradient, pulmonary capillary wedge, left ventricular filling pressures and the severity of mitral regurgitation, and improve the markedly altered diastolic function. The significant symptomatic improvement allows a reduction in medical treatment. Thus, it represents a viable alternative to open-heart surgery, particularly in elderly patients, with lower morbidity and mortality rates.

Adult↗
PubMed1999

Filtration of Unipolarly Charged Aerosol Nanoparticles with an Initially Discharged Dielectric Screen.

This paper presents experimental results of penetration of nanometer-sized aerosol particles through an initially discharged dielectric screen. Experiments have been carried out with two types of monodisperse unipolarly charged particles having different dielectric constants (Ag and NaCl) and mobility-equivalent particle diameters between 2 and 10 nm (Peclet number between 4 and 80). At the very beginning of the process, the screen is uncharged and filtration is controlled by particle diffusion. As the number of charges on the screen increases due to the diffusional deposition of charged particles, an electric field of increasing strength is developed between the dielectric screen and the conductive metallic walls of the cylinder where the screen is placed. As a result, particles are also driven and lost to the walls and penetration decreases. This transient process can be well described by two dimensionless parameters, namely the Peclet number and a nondimensional number expressing the ratio of the particle drift velocity due to the field to the particle convective velocity due to the flowing medium (air). Copyright 1999 Academic Press.

Journal Article↗
PubMed1999

[Disseminated cryptococcosis in patients with AIDS. Prognostic factors of poor outcome].

BACKGROUND: The objectives of this study were to analyze the changes in the incidence of cryptococcal disease in the last 10 years (1987-1997) and to assess the factors of poor prognosis in HIV-1 infected patients. PATIENTS AND METHODS: Clinical records of HIV-1 infected patients diagnosed with cryptococcal infection from June 1987 to December 1997 at Hospital Clinic i Provincial in Barcelona, Spain, were examined. An univariate and multivariate analysis of the predictors of poor outcome was performed. RESULTS: Sixty clinical records were analyzed. The number of cases per 100 exposed patients per year decreased from 1991 to 1993 and, afterwards, decreased again from 1996. Fifty patients had a resolution of clinical symptoms, 17 out of this 50 patients (34%) had a relapse. Factors associated with a higher risk of relapse were a positive blood culture and cryptococcal antigen title in cerebrospinal fluid above 1/1.024. CONCLUSIONS: The decrease in the number of cases of cryptococcal infection coincides with the broad use of triazole antifungal drugs for oral candidiasis (1990-1991) and, afterwards, with the initiation of highly active antiretroviral therapy (1996). The best predictors of relapse are a positive blood cryptococcal culture and a high titter of cryptococcal antigen.

AIDS-Related Opportunistic Infections↗
PubMed1999

Spectrum of CFTR mutations in the Middle North of Spain and identification of a novel mutation (1341G-->A). Mutation in brief no. 252. Online.

We have analyzed 39 unrelated cystic fibrosis (CF) families by denaturing gradient gel electrophoresis (DGGE) and direct sequencing in order to determine the spectrum of CF mutations in our population. This approach has allowed us to detect 72 out of the 78 CF chromosomes (92.3%). The DF508 mutation was found to be present in 51/78 (65.4%) CF chromosomes, in accordance with the predicted Northwest-Southeast gradient within the European population. Another 14 known mutations, and the novel 1341G-->A mutation were identified. Nine out of fifteen non DF508 mutations were present in a single chromosome. The 1341G-->A mutation, found in 2 unrelated patients, is a new mutation associated to severe phenotype, causing pancreatic insufficiency and chronic lung infections. Our data suggest a different distribution of non-DF508 mutations in our population when compared with previous studies carried out in Spanish CF families. Six out of the 14 non-F508 in our study were not present in a recent study carried out in 640 Spanish families with CE These six mutations account for 29.6% non DF508 chromosomes in our sample.

Cystic Fibrosis↗
PubMed1999

Performance of thiophilic adsorption chromatography in the purification of rat IgG2b monoclonal antibodies from serum- and protein-free culture supernatants.

The usefulness of thiophilic adsorption chromatography for the purification of rat IgG2b monoclonal antibodies has been evaluated. This approach has not shown specificity for immunoglobulins; therefore, to minimize potential interferences, the purification was carried out from supernatants of hybridomas grown in serum- and protein-free conditions. The protein purity of the six final antibody preparations assayed was always >/= 97%. In addition to the easiness of this procedure, which enables one-step antibody purification, the materials employed are rather inexpensive and milligram amounts of antibody can be recovered from 1 L of supernatant. Overall, the purification of rat IgG2b monoclonals under the conditions reported here offers an advantageous alternative to other more expensive and cumbersome methods.

Animals↗
PubMed1999

Vitamin D receptor ontogenesis in rat liver.

Vitamin D through its receptor (VDR) plays a major role in bone mineral metabolism. However, VDR is also present in a variety of cell lines as well as in numerous tissues, suggesting other functions of the hormone beyond bone metabolism and mineral homeostasis. At the liver level, it has been shown that vitamin D induces numerous changes (i.e. enzyme activity level, stimulation of some metabolic pathways and stimulation of the normal liver recovery after partial hepatectomy). However, some works did not find VDR in the liver, and also used liver tissue as a negative control of VDR gene expression. In this paper, we examined fetal, neonatal and adult rat tissues for the presence of VDR using a sensitive RT-PCR technique and immunohistochemistry. We found VDR mRNA and VDR protein in rat liver at all different periods of rat life. Thus, we suggest that some of the actions of vitamin D on liver could be mediated at the genomic level through the VDR, and that the use of this tissue as a negative control of VDR gene expression is clearly inappropriate.

Animals↗
PubMed1999

Viral coinfection in salmonids: infectious pancreatic necrosis virus interferes with infectious hematopoietic necrosis virus.

Coinfection of farm-reared salmonids involving two viruses has been described, but there is no report on the interactions between viruses. Here we examine whether infectious pancreatic necrosis virus (IPNV) strain Sp interferes with the growth of infectious hematopoietic necrosis virus (IHNV) strain S46, a coinfected isolate from rainbow trout. When BF-2 cell culture was inoculated with S46 the infective titer of the IHNV fraction decreased by 3 log10 units compared to the growth curve of IHNV in the single infection. RT-PCR assay confirmed this reduction, which after successive passages of the co-infected sample led to a decrease in IHNV mRNA and the absence of the specific PCR product for IHNV. Flow cytometry showed that only 13% of the cells inoculated with S46 strain were infected with IHNV at 48-72 h post infection, in contrast to the 50-80% of cells that were positive for IPNV. Exposure of cells to IHNV for 24 h before infection with IPNV did not affect the infective titers of either virus or the PCR results obtained in simultaneous coinfections. Moreover IHNV was not inhibited when the IPNV inoculum was reduced. So, a multiplicity of infection dependence was demonstrated for IPNV-IHNV interference; the RT-PCR assay described here was found to be a suitable technique for identifying and studying dual viral infections.

Animals↗
PubMed1999

Cryopreserved arterial homografts: preliminary results in infrageniculate arterial reconstructions.

The aim of this report is to present our preliminary experience using cryopreserved arterial homografts in below-knee revascularization. We carried out a retrospective study at the Public Health Hospital of the Servicio Galego da Saude (SERGAS) from October 1995 to March 1997 in which cryopreserved arterial homografts were used for revascularization of 17 lower limbs in 16 patients. The clinical indications were limb-threatening ischemia in 15 lower extremities (7 with rest pain and 8 with ischemic ulcers or gangrene), and large aneurysms of femoropopliteal arteries in 2. In addition, 75% of the patients had undergone previous surgical procedures for revascularization on the involved extremity. No patient had a suitable greater saphenous vein in the ipsilateral extremity and all patients required a below-knee arterial reconstruction procedure. There was just one runoff vessel in 11 of 17 extremities (65%). A histological exam was performed in four patients who died (1 case) or had homograft-related complications (3 cases). The results of this study indicated that cryopreserved arterial homografts could be a promising alternative when below-knee revascularization is required in patients lacking suitable greater saphenous vein, especially in those with limited life expectancy, but despite early acceptable results, many aspects must be clarified. Close follow-up is mandatory.

Aged↗
PubMed1999

Induction of puberty with human chorionic gonadotropin and follicle-stimulating hormone in adolescent males with hypogonadotropic hypogonadism.

OBJECTIVE: To evaluate the clinical and hormonal responses of adolescent males with hypogonadotropic hypogonadism (HH) in response to gonadotropin replacement with the use of long-term combined hCG and FSH therapy. DESIGN: Prospective clinical study. SETTING: Clinical pediatric department providing tertiary care. PATIENT(S): Seven prepubertal males with isolated HH with a mean (+/-SD) age of 15.44+/-1.97 years and seven prepubertal males with panhypopituitarism-associated HH with a mean (+/-SD) age of 18.1+/-3.24 years were studied. INTERVENTION(S): Human chorionic gonadotropin (1,000-1,500 IU IM) and FSH (75-100 IU SC) were administered every alternate day of the week until the total induction of puberty and spermatogenesis was achieved. MAIN OUTCOME MEASURE(S): Serum testosterone levels, testicular volume, penis length, and sperm count were evaluated after the administration of hCG and FSH. RESULT(S): All patients achieved normal sexual maturation and normal or nearly normal adult male levels of testosterone. The increase in testicular size was significant in both groups. Positive sperm production was assessed in four of five patients with isolated HH and in three of three patients with panhypopituitarism-associated HH. CONCLUSION(S): Long-term combined hCG and FSH therapy is effective in inducing puberty, increasing testicular volume, and stimulating spermatogenesis in adolescent males with isolated HH and panhypopituitarism-associated HH.

Adolescent↗
PubMed1999

Nested PCR improves detection of infectious hematopoietic necrosis virus in cells coinfected with infectious pancreatic necrosis virus.

A nested assay using the reverse transcription-polymerase chain reaction (RT-PCR) was developed for the detection of infectious hematopoietic necrosis virus (IHNV) in cell cultures coinfected with infectious pancreatic necrosis virus (IPNV). Two pairs of primers were designed: one for the amplification of glycoprotein G-specific gene RNA from IHNV (or 1512 bp fragment), and the other for the amplification of an inner 753 bp fragment using the cDNA from the G gene as substrate. Direct RT-PCR was also developed for the amplification of a VP-2 gene fragment from IPNV (613 bp fragment); this method always detected the virus IPNV in the coinfected cells tested but the amplification of IHNV was not as readily achieved. IHNV, however, was detected specifically by nested PCR in coinfected cells at a multiplicity of infection that was 1000 times lower than that of IPNV. Nested PCR was therefore more sensitive than direct RT-PCR for IHNV, and may thus be more appropriate for the detection of low infective titers of IHNV in the presence of IPNV when interference occurs.

Animals↗
PubMed1999

Congruent docking of dimeric kinesin and ncd into three-dimensional electron cryomicroscopy maps of microtubule-motor ADP complexes.

We present a new map showing dimeric kinesin bound to microtubules in the presence of ADP that was obtained by electron cryomicroscopy and image reconstruction. The directly bound monomer (first head) shows a different conformation from one in the more tightly bound empty state. This change in the first head is amplified as a movement of the second (tethered) head, which tilts upward. The atomic coordinates of kinesin.ADP dock into our map so that the tethered head associates with the bound head as in the kinesin dimer structure seen by x-ray crystallography. The new docking orientation avoids problems associated with previous predictions; it puts residues implicated by proteolysis-protection and mutagenesis studies near the microtubule but does not lead to steric interference between the coiled-coil tail and the microtubule surface. The observed conformational changes in the tightly bound states would probably bring some important residues closer to tubulin. As expected from the homology with kinesin, the atomic coordinates of nonclaret disjunctional protein (ncd).ADP dock in the same orientation into the attached head in a map of microtubules decorated with dimeric ncd.ADP. Our results support the idea that the observed direct interaction between the two heads is important at some stages of the mechanism by which kinesin moves processively along microtubules.

Adenosine Diphosphate↗