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Biomedical subjects

M Hernández

Publications and source records attributed to M Hernández.

At least 19 recordsLinked to original sources
PubMed2007

Personality in patients with migraine evaluated with the "Temperament and Character Inventory".

The objective of this study was to assess the personality profile of a sample of Mexican patients with migraine using the Temperament and Character Inventory (TCI). A cross-sectional study was performed including adult migraine patients identified from the outpatient neurology clinics of two large teaching hospitals in Mexico City. Patients were asked to voluntarily participate in the study. A physician conducted a standardised diagnostic interview adhering to the criteria of the International Headache Society (IHS). Patients were interviewed and administered the TCI. We used two healthy controls groups and a third group of non-migraine pain controls. One hundred and fortytwo subjects with migraine, 108 healthy blood donors, 269 young healthy controls and 30 patients with non-migraine pain (NMP) were included in the study. Patients with migraine had higher scores in the dimension harm avoidance (HA) and all its sub-dimensions (p<0.05) than healthy patients. Patients with non-migraine pain had high scores in HA and low scores in novelty seeking, self-directedness and cooperativeness. Blood donors had high scores in the following subdimensions: HA1, HA4 and C3 (Cooperativeness). Personality features consistent with migraine are avoidance, rigidity, reserve and obsessivity. Our study shows that patients with chronic pain share some of the personality features of patients with migraine but their TCI profile could be indicative of cluster C avoidant personality. Blood donors were shown to have more energy, with a tendency to help other people and be more optimistic. The results support serotoninergic involvement as explaining the physiopathology of migraine.

Adult↗
PubMed2006

Further evaluation of the synthetic peptide vaccine S3Pvac against Taenia solium cysticercosis in pigs in an endemic town of Mexico.

Taenia solium cysticercosis is a parasitic disease frequently affecting human health and the pig industry in many developing countries. A synthetic peptide vaccine (designated S3Pvac) against porcine cysticercosis has been developed previously as an aid to interrupt transmission and has been shown to be effective. The results of the present study support the effectiveness of the vaccine under endemic field conditions. However, given the time-frame of the vaccination trial, no changes in the local levels of transmission were detectable before and after vaccination using sentinel pigs. Thus, this investigation shows the limited usefulness of single vaccination as the sole means of interrupting Taenia solium transmission in an endemic region.

Animals↗
PubMed2006

Neuronal and smooth muscle receptors involved in the PACAP- and VIP-induced relaxations of the pig urinary bladder neck.

BACKGROUND AND PURPOSE: As pituitary adenylate cyclase-activating polypeptide 38 (PACAP 38)- and vasoactive intestinal peptide (VIP) are widely distributed in the urinary tract, the current study investigated the receptors and mechanisms involved in relaxations induced by these peptides in the pig bladder neck. EXPERIMENTAL APPROACH: Urothelium-denuded strips were suspended in organ baths for isometric force recordings and the relaxations to VIP and PACAP analogues were investigated. KEY RESULTS: VIP, PACAP 38, PACAP 27 and [Ala(11,22,28)]-VIP produced similar relaxations. Inhibition of neuronal voltage-gated Ca(2+) channels reduced relaxations to PACAP 38 and increased those induced by VIP. Blockade of capsaicin-sensitive primary afferents (CSPA), nitric oxide (NO)-synthase or guanylate cyclase reduced the PACAP 38 relaxations but failed to modify the VIP responses. Inhibition of VIP/PACAP receptors and of voltage-gated K(+) channels reduced PACAP 38 and VIP relaxations, which were not modified by the K(+) channel blockers iberiotoxin, charybdotoxin, apamin or glibenclamide. The phosphodiesterase 4 inhibitor rolipram and the adenylate cyclase activator forskolin produced potent relaxations. Blockade of protein kinase A (PKA) reduced PACAP 38- and VIP-induced relaxations. CONCLUSIONS AND IMPLICATIONS: PACAP 38 and VIP relax the pig urinary bladder neck through muscle VPAC(2) receptors linked to the cAMP-PKA pathway and involve activation of voltage-gated K(+) channels. Facilitatory PAC(1) receptors located at CSPA and coupled to NO release, and inhibitory VPAC receptors at motor endings are also involved in the relaxations to PACAP 38 and VIP, respectively. VIP/PACAP receptor antagonists could be useful in the therapy of urinary incontinence produced by intrinsic sphincter deficiency.

Adenylyl Cyclases↗
PubMed2006

Long term NSAID treatment inhibits COX-2 synthesis in the knee synovial membrane of patients with osteoarthritis: differential proinflammatory cytokine profile between celecoxib and aceclofenac.

OBJECTIVE: To compare the effect of celecoxib with that of a classic non-steroidal anti-inflammatory drug (NSAID) on synovial inflammation and on the synovial expression of proinflammatory genes in patients with knee osteoarthritis (OA). METHODS: 30 patients with severe knee OA scheduled for total knee replacement surgery were included in a 3 month clinical trial. They were randomised to two groups: patients treated with celecoxib (CBX) (200 mg/24 h) and patients treated with aceclofenac (ACF) (100 mg/12 h). Those patients with OA who did not want to be treated with NSAIDs served as a control group. During knee surgery, synovial fluid (SF) and synovial membrane (SM) were collected. A SM specimen was fixed and embedded in paraffin and another part was frozen for molecular biology studies. RESULTS: At the end of study both CBX and ACF treated patients showed a significant improvement in pain and knee function compared with controls. Both drugs significantly reduced prostaglandin E(2) (PGE(2)) SF concentration and down regulated COX-2 mRNA and protein expression at the SM. However, synovial macrophage infiltration (CD68 antigen staining) and expression of proinflammatory mediators, such as interleukin 1beta and tumour necrosis factor alpha, were decreased only by CBX treatment. CONCLUSION: Both drugs improved joint pain and function, inhibited SF PGE(2) concentration, and induced a decrease in synovial COX-2 expression and synthesis not related to the tissue inflammatory status. These data suggest that PGE(2) blocking agents may decrease PGE(2) production not only by direct COX-2 inhibition but also by down regulating COX-2 expression and synthesis. However, CBX and ACF appear to have different anti-inflammatory profiles in controlling OA synovial macrophage infiltration and proinflammatory expression.

Aged↗
PubMed2006

Tumour banks in pediatric oncology.

INTRODUCTION: The information offered by the new genomic and proteomic techniques will play a central role in our knowledge of cancer; but it is limited by the lack of available tissue samples. Cancer in children is a sum of infrequent diseases, so tumor banks are support tools for translational research, providing access to a sufficiently large series of samples, which would minimize the asymmetric effect of the diverse origin. MATERIAL AND METHODS: From 2003 a Molecular Pathology Network in Pediatric Solid Tumors Netwoks exists in Spain, and we are a part of it. Our aim was to create a pediatric tumor bank program and consensus documents about its use. RESULTS: Standard Operating Procedures for collection and transport of samples have been created. CONCLUSIONS: Thinking about the fast progress in Molecular Biology and the low frequency in pediatric tumors, it is vital to consider the importance of a bio bank.

Adolescent↗
PubMed2006

Is there any association between nek3 and cancers with frequent 13q14 deletion?

Chromosomal region 13q14 is frequently deleted in prostate cancer. nek3, a protein kinase related gene, is located on this region. Analysis of the coding region of nek3 showed an A insertion/deletion polymorphism in a stretch of adenines at the end of exon 9, with 2 alleles showing either 7 or 8 adenines. In addition we found a variant human NEK3 transcript, which lacks the entire exon 10 due to alternative splicing. The frequency of A8 allele is statistically higher in prostate cancer samples (p < 0.001) than normal controls, indicating that tumor samples preferentially express a full length protein. On the contrary, normal samples have a higher frequency for the A7 allele, expressing preferentially a shorter protein. To test if this association is a common feature in cancers with frequent 13q14 alterations, we analyzed cell lines established from oral, lung, and hepatocellular cancers. An association between nek3 A insertion/deletion polymorphism and cancers with alterations at 13q14 is observed.

Carcinoma, Hepatocellular↗
PubMed2006

Genetic change in the polynesian population of Easter Island: evidence from Alu insertion polymorphisms.

The origin of Pacific islanders is still an open issue in human population genetics. To address this topic we analyzed a set of 18 Alu insertion polymorphisms in a total of 176 chromosomes from native Easter Island inhabitants (Rapanui). Available genealogical records allowed us to subdivide the total island sample into two groups, representative of the native population living in the island around 1900, and another formed by individuals with some ancestors of non-Rapanui origin. Significant genetic differentiation was found between these groups, allowing us to make some biodemographic and historical inferences about the origin and evolution of this geographically isolated island population. Our data are consistent with equivalent and recent contributions from Amerindian and European migrants to the 1900s Rapanui population, with an accelerated increase in the European gene flow during the 20(th) century, especially since the 1960s. Comparative analysis of our results with other available Alu variation data on neighbouring populations supports the "Voyaging Corridor" model of Polynesian human settlement, which indicates that pre-Polynesians are mainly derived from Southeast Asian and Wallacean populations rather than from Taiwan or the Philippines. This study underlines the importance of sampling and taking into account historical information in genetic studies to unravel the recent evolution of human populations.

Alu Elements↗
PubMed2006

Factors influencing boar sperm cryosurvival.

Optimal sperm cryopreservation is a prerequisite for the sustainable commercial application of frozen-thawed boar semen for AI. Three experiments were performed to identify factors influencing variability of postthaw sperm survival among 464 boar ejaculates. Sperm-rich ejaculate fractions were cryopre-served using a standard freezing-thawing procedure for 0.5-mL plastic straws and computer-controlled freezing equipment. Postthaw sperm motility (assessed with a computer-assisted semen analysis system) and viability (simultaneously probed by flow cytometry analysis after triple-fluorescent stain), evaluated 30 and 150 min postthaw, were used to estimate the success of cryopreservation. In the first experiment, 168 unselected ejaculates (1 ejaculate/boar), from boars of 6 breeds with a wide age range (8 to 48 mo), were cryopreserved over a 12-mo period to evaluate the predictive value of boar (breed and age), semen collection, transport variables (season of ejaculate collection, interval between collections, and ejaculate temperature exposure), initial semen traits, and sperm quality before freezing on sperm survival after freezing-thawing. In Exp. 2, 4 ejaculates from each of 29 boars, preselected according to their initial semen traits and sperm quality before freezing, were collected and frozen over a 6-mo period to evaluate the influence of interboar and intraboar ejaculate variability in the survival of sperm after cryopreservation. In Exp. 3, 12 ejaculates preselected as for Exp. 2, from each of 15 boars with known good sperm cryosurvival, were collected and frozen over a 12-mo period to estimate the sustainability of sperm cryosurvival between ejaculates over time. Boar and semen collection and transport variables were not predictive of sperm cryosurvival among ejaculates. Initial semen traits and sperm quality variables observed before freezing explained 23.2 and 10.9%, respectively, of the variation in postthaw sperm motility and viability. However, more that 70% of total variance observed in postthaw sperm quality variables among ejaculates was explained by boar. This indicates that boar is the most important (P < 0.001) factor explaining the variability among ejaculates in sperm cryosurvival, with most (14 of the 15 boars in Exp. 3) showing consistent (P > 0.05) sperm cryosurvival over time.

Animals↗
PubMed2006

Strategies to improve the fertility of frozen-thawed boar semen for artificial insemination.

Although cryopreservation of boar semen for artificial insemination (AI) was developed 35 years ago, cryopreservation conditions and AI strategies are still considered sub-optimal. AI with excessive numbers of frozen-thawed sperm (5-6 x 10(9) cells), still does not achieve fertility levels similar to AI using liquid semen because of reduced sperm survival. Frozen-thawed (FT) spermatozoa have therefore not been the preferred option for commercial breeding programmes. However, substantial progress has been made regarding boar sperm cryopreservation. Adjustment of cooling and re-warming rates to biophysical properties of boar spermatozoa, new sperm package systems and the achievement of accurately consistent freezing of large numbers of samples using programmable freezers have contributed to post-thaw survival rates above 50%, a threshold similar to that used for bull AI-semen. Moreover, these post-thaw sperm survival rates are consistent within a large population of boars selected for sperm freezability potential, as occurs with AI-bull sires. When such post-thaw boar semen is deposited intra-utero, acceptable fertility (in terms of farrowing rates and litter size) is obtained. Currently, the most effective application of FT-semen for AI is achieved using deep uterine-AI (DUI) which allows placement of a minimal semen dose (in volume 0.5 to 10 mL and sperm number 0.5 to 1 x 10(9) total spermatozoa) into the anterior 1/3 of one uterine horn, with levels of fertility close to AI with liquid semen. However, owing to their shorter life span, FT-boar spermatozoa require an AI-to-ovulation interval not longer than 4-6 h, making peri-ovulatory AI a pre-requisite to obtain the highest possible fertility. Spontaneous ovulation most often occurs when two-thirds of oestrus has passed. Estimation of the duration of oestrus, taking into account the weaning-to-oestrus interval, is helpful when establishing appropriate AI-schedules. However, as the length of oestrus varies within and between farms, different AI strategies should be established a priori. The development of bio-sensors for spontaneous ovulation will widen the use of AI with frozen-thawed frozen semen.

Animals↗
PubMed2006

[Cardiac and vascular homograft valves transplant].

The advances in the manipulation of human tissues, the development of cryobiology, paediatric cardiac surgery, the impossibility of obtaining an ideal prosthetic cardiac valve and the surgical treatment of cardiovascular infections have revived interest in the use of homografts. The donors of these homografts can be: a) Live donors: aortic and pulmonary valve of the recipient of a heart transplant; b) Multiorgan donors with a diagnosis of death according to neurological criteria, whose heart is rejected for heart transplant; c) Cadaver donors with asystolia of less than 8 hours. Homograft cardiac valves are the substitute of choice in aortic valve endocarditis, patients with counter-indications for anticoagulation, reconstruction of the outflow tract of the right ventricle, aortic valve replacement in children and young adults through the Ross operation, and an optional indication is the aortic valve and/or rising aorta replacement in patients over 60 years of age. Although there are not sufficiently broad series of homogratfs with arterial substitutes, with respect to the number of patients and time of evolution, the results suggest that this can benefit patients with vascular infection, immunodepressed patients or complex patients whose technique during the operation might require a homograft.

Adult↗
PubMed2005

Does multivariate analysis of post-thaw sperm characteristics accurately estimate in vitro fertility of boar individual ejaculates?

The objective of this study was to determine if a multivariate pattern analysis of frozen-thawed sperm characteristics of boar semen of unknown fertility, thus identifying groups of ejaculates as "good" or "bad" freezers, would estimate their fertilizing potential in an in vitro embryo production (IVP) system. Frozen-thawed spermatozoa from a single ejaculate collected from 46 boars were evaluated for sperm motility and kinematic patterns, for sperm viability and for early changes in sperm membrane stability. All data generated were used for a multivariate pattern analysis (PATN; CSIRO, Canberra, Australia) which objectively classified all ejaculates within a data set in to one of two groups, categorised as "good" (n = 25) or "bad" (n = 21) according with their freezability. In vitro matured oocytes were exposed to 2000 or 4000 frozen-thawed spermatozoa per oocyte for 6h and then cultured in embryo culture medium for either 6h (assurance of fertilization) or 7 days (to collect data on embryo development). Rates of sperm oocyte penetration and of embryo development significantly (p < 0.05) increased in a sperm:oocyte ratio-dependent manner. A similar pattern was observed when sperm characteristics were grouped. Indeed, ejaculates classified as "good" showed significantly (p < 0.05) higher rates of oocyte penetration, cleavage and of blastocyst formation than those classified as "bad". However, variation was still present among individuals (ejaculates, boars) in their ability to produce blastocysts in vitro. It is therefore concluded that despite the presence of a relationship for ejaculates with good semen quality post-thaw (thus grouped as "good") to higher IVP-results, the presence of individual variation does not allow for an accurate estimation of in vitro fertility based solely on the frozen-thawed semen quality parameters of a single ejaculate from a given boar.

Analysis of Variance↗
PubMed2005

Biological and behavioral determinants of fertility in Tierra del Fuego.

The reproductive history of 182 women in postreproductive life or near menopause from the Chilean part of Tierra del Fuego was traced back by means of familial interviews. These postmenopausal women represent the population since almost the beginning of the settlement, and their reproductive years were spent on the island. Path analysis was applied to analyze fertility determinants of these women and to propose a complex model of interconnections among factors. The reproductive history of these women is characterized by a long fertile span, a short childbearing period, and low fertility. Age at menarche is relatively late, and the age of the women at first birth is mainly determined by their late age at marriage. The use of contraception is related to both spacing and stopping behaviors. The late age of women at marriage, the rhythm of conception, and practices of contraception are proposed as the main determinants of fertility in Tierra del Fuego.

Age Factors↗
PubMed2005

Antimicrobial peptides are among the antagonistic metabolites produced by Bifidobacterium against Helicobacter pylori.

Sixty acid-resistant Bifidobacterium isolates were recovered from human faeces and identified by genus-specific PCR and RAPD-PCR. Helicobacter pylori strains were isolated from gastric biopsies and identified by species-specific PCR. Twenty-four of the 60 Bifidobacterium isolates were considered to be different strains by RAPD-PCR. Six of the twenty-four different strains were shown to inhibit H. pylori. These antagonistic effects were related to heat-stable proteinaceous compounds, resistant to heating at 100 degrees C for 10 min, but sensitive to proteases. H. pylori stains showed variable resistance to therapeutic antibiotics (metronidazole and clarithromycin), while all the selected bifidobacteria showed intrinsic resistance to metronidazole. These potentially probiotic bifidobacteria were able to inhibit the growth of both antibiotic sensitive and resistant H. pylori strains. Thus, the synthesis of antimicrobial peptides could be one of the mechanisms of bifidobacteria to combat H. pylori infections.

Acetic Acid↗
PubMed2005

Urgent lung transplantation in Spain.

BACKGROUND: Lung donors are scarce and lung transplantation resources are limited. Because urgent lung transplantation (ULT) is assumed to yield poor results, its use is controversial. We assessed the outcome of patients who received ULT seeking to determine effectiveness and risk factors. PATIENTS AND METHOD: We collected data from every ULT performed in Spain during 5 years (1998-2002). The survival of patients was studied using Kaplan-Meier, Cox regression, and chi-square statistical analyses. We compared outcomes and perioperative mortality (over 30 days) for ULT procedures, analyzing the influence of certain variables (age, type of transplant, diagnosis, indication, and time on waiting list). RESULTS: Among 109 patients proposed for the procedure, 73 ULT were performed during the period. The most frequent indications were pulmonary fibrosis (19 cases) and cystic fibrosis (19 cases), showing the worst and the better survival rates, respectively. The bad prognosis, determined mainly by per operative mortality rate (35.62%), was significantly affected by age (worse for patients older than 40 years) and type of LT (single worse than double; P < .05). A longer time waiting for ULT also showed a worse prognosis (P < .005). CONCLUSIONS: Long-term survival after ULT shows that the procedure is effective and efficient for a select group of patients, despite the high per operative risk. ULT should be reserved for younger patients. It also requires performance in a short period (just a few days), initially rejecting a single lung transplant, provided that the patient is adequately monitored.

Humans↗
PubMed2005

Typical isolated ectrodactyly of hands and feet: early antenatal diagnosis.

Ectrodactyly is a rare dominant autosomal malformation with variable expression. Herein we report a case early diagnosed by ultrasound at 15 weeks of gestation of isolated ectrodactyly involving the four limbs. The sonographic findings were bilateral split hands and split foot. Diagnosis of typical isolated ectrodactyly was pathologically confirmed. Clinical forms, pathogenesis, differential diagnosis, and early prenatal diagnosis are discussed.

Abortion, Induced↗
PubMed2005

[Comparison of three methods of inducing chronic elevation of intraocular pressure in the pig (experimental glaucoma)].

PURPOSE: To compare three methods of inducing experimental glaucoma in the adult pig, based on achieving chronic elevation of the intraocular pressure (IOP). METHODS: A total of 16 adult pigs were used in the present study. In all instances, the right eye was used as control and the left eye as the experimental eye. The animals were divided into three groups: 1) 3 pigs in which 3 episcleral veins were cauterized (experimental period = 21 weeks); 2) 6 animals in which the anterior chamber of the eye was injected with a solution containing latex fluorospheres (experimental period = 11 weeks); and 3) 4 pigs in which the anterior chamber of the eye was injected with a solution containing latex fluorospheres plus methylcellulose (experimental period = 11 weeks). RESULTS: The episcleral vein cauterization was the only method which produced a sustained elevation of the IOP throughout most of the experimental period. Moreover, the elevation of the IOP achieved by this method resulted in selective retinal ganglion cell (RGC) loss that affected mainly the mid-peripheral and peripheral retina and caused an increase in the mean soma area of the remaining RGCs. CONCLUSIONS: Cauterization of the episcleral veins resulted in a significant and sustained elevation of the IOP and RGC loss when compared with the other two approaches tested in the present study, which barely modified the pig's RGC distribution. Thus, we conclude that the episcleral vein cauterization is the best of the methods tested to induce experimental glaucoma in the pig.

Animals↗