PubMed Health⌕ Search

Biomedical subjects

J Calvo

Publications and source records attributed to J Calvo.

At least 19 recordsLinked to original sources
PubMed2006

Globally dispersed Y chromosomal haplotypes in wild and domestic sheep.

To date, investigations of genetic diversity and the origins of domestication in sheep have utilised autosomal microsatellites and variation in the mitochondrial genome. We present the first analysis of both domestic and wild sheep using genetic markers residing on the ovine Y chromosome. Analysis of a single nucleotide polymorphism (oY1) in the SRY promoter region revealed that allele A-oY1 was present in all wild bighorn sheep (Ovis canadensis), two subspecies of thinhorn sheep (Ovis dalli), European Mouflon (Ovis musimon) and the Barbary (Ammontragis lervia). A-oY1 also had the highest frequency (71.4%) within 458 domestic sheep drawn from 65 breeds sampled from Africa, Asia, Australia, the Caribbean, Europe, the Middle East and Central Asia. Sequence analysis of a second locus, microsatellite SRYM18, revealed a compound repeat array displaying fixed differences, which identified bighorn and thinhorn sheep as distinct from the European Mouflon and domestic animals. Combined genotypic data identified 11 male-specific haplotypes that represented at least two separate lineages. Investigation of the geographical distribution of each haplotype revealed that one (H6) was both very common and widespread in the global sample of domestic breeds. The remaining haplotypes each displayed more restricted and informative distributions. For example, H5 was likely founded following the domestication of European breeds and was used to trace the recent transportation of animals to both the Caribbean and Australia. A high rate of Y chromosomal dispersal appears to have taken place during the development of domestic sheep as only 12.9% of the total observed variation was partitioned between major geographical regions.

Alleles↗
PubMed2005

Preliminary study of choledochocholedochostomy without T tube in liver transplantation: a comparative study.

INTRODUCTION: Biliary anastomosis during liver transplantation can be safely performed using an end-to-end choledochocholedochostomy, with or without a T tube. The objective of this study was to determine whether the insertion of a T tube was related to more postoperative complications. METHODS: Between April 1986 and September 2004, we performed a retrospective, longitudinal, and comparative study of 1012 liver transplantations, including 50 adult recipients with a T tube and a control group with a choledochocholedochostomy without a T tube. RESULTS: T tube insertion was associated with more postoperative complications and worse actuarial survival of both the recipient and graft, though these differences did not reach statistical significance. CONCLUSION: The duct-to-duct biliary anastomosis stented with a T tube tends to be associated with more postoperative complications. Based on this analysis, we recommend the performance of a nonstented anastomosis.

Biliary Tract Diseases↗
PubMed2005

Comparative analysis of the results of orthotopic liver transplantation in patients with and without portal vein thrombosis.

INTRODUCTION: Portal vein thrombosis (PVT), which had been considered an absolute contraindication to orthotopic liver transplantation (OLT), is currently considered a risk factor that increases morbi-mortality. The objective of this study was to compare OLT outcomes in patients with vs without PVT. MATERIALS AND METHODS: Between April 1986 and December 2003, a sample of 83 patients with PVT was compared with another sample of 83 patients without PVT among 962 OLT performed in our department. RESULTS: Both groups were homogeneous in terms of epidemiological variables, surgical technique, immunosuppression, and donor-related variables. There were no differences with respect to graft function during the first week following surgery. Surgical time and anhepatic phase duration was longer in the PVT group, albeit the differences were not significant. PVT patients also required more transfusions; a strong statistical association was observed with respect to blood (P = .12) and plasma (P = .11) transfusions and statistically significant differences regarding platelet transfusions (P = .02). Time on mechanical ventilation and the length of stay in the ICU were longer but not significant among PVT patients. The only statistically significant difference was the incidence of portal rethrombosis (P = .02). With respect to mean and global patient and graft actuarial survivals after 1, 3, 5, and 10 years, we have observed no significant intergroup differences, although both patient (P = .48; NS) and graft (P = .96, NS) survivals were lower among PVT cases. CONCLUSIONS: PVT should not only cease to be considered a contraindication for OLT, but there were no significant differences between the outcomes despite this finding.

Adolescent↗
PubMed2005

Modulation of hepatocyte growth factor plasma levels in relation to the dose of exogenous heparin administered: an experimental study in rats.

INTRODUCTION: Partial liver transplantation has been consolidated to be a valid treatment option. We sought to understand the factors that modulate and may be harnessed to accelerate hepatocyte regeneration. We sought to determine the impact of heparin on m-hepatocyte growth factor (HGF) plasma concentrations. MATERIALS AND METHODS: Sixteen rats were assigned to four groups of four animals each: group A, without heparin; group B, 600 IU/kg; group C, 1000 IU/kg, group D, 1400 IU/kg. Blood samples (0.5 mL) were obtained from each rat at baseline and at 30, 60, 120, and 240 minutes. After the samples were centrifuged to separate supernates from the cell phase they were stored at -20 degrees C in the m-HGF reagent and subsequently tested using enzyme-linked immunosorbent assay. Results were analyzed using SPSS 11.5 statistical software. RESULTS: Among the 16 rats, one died at 110 minutes, just prior to the last extraction. The remaining rats were sacrificed. Mean weight was: 466 +/- 64.24 g with no intergroup differences (P = .149). The comparative results (using Student t test) were: baseline A(1-4) versus A(1-4) 30 minutes: P < .05; baseline A(1-4) versus A(1-4) 60 minutes: P < .05; baseline A(1-4) versus A(1-4) 120 minutes: P = .10 (NS); baseline A(1-4) versus A(1-4) 240 minutes: P = .15 (NS). No significant differences were found among group B: baseline C(1-4) versus C(1-4) 30 minutes and 60 minutes: NS; baseline C(1-4) versus C(1-4) 120 minutes: P < .001; baseline C(1-4) versus C(1-4) 240 minutes: P < .10 (NS). Finally, the results in group D were: baseline D(1-4) versus D(1-4) 30 minutes: NS; baseline D(1-4) versus D(1-4) 60 minutes and 120 minutes: P < .05; baseline D(1-4) versus D(1-4) 240 minutes: P < .0005. When we compared group A to C and D, we detected differences (albeit not when compared to B) with P values = .01. Peak values were obtained at 120 and 240 minutes (225.21 pg/mL and 221.78 pg/mL) among groups C and D. CONCLUSION: Heparin has a positive effect to increase serum HGF concentrations among rats. The effect was dependent on the administered dose and the time elapsed.

Animals↗
PubMed2005

[Combined intratympanic and intravenous dexomethasone to control vertigo in Meniere disease].

OBJECTIVE: To verify the result in the use of intratympanic corticosteroids, combined with intravenous, in patients with Meniere disease (MD). MATERIAL AND METHODS: Ten patients with vertigo due to MD in stages 4-5 or 6 were included in the study. Combined intratympanic and intravenous dexamethasone was infiltrated. The number of episodes among the months 18 and 24 of treatment, comparing them with the number of episodes 6 months before treatment (according to the norms of the American committee for the hearing and the equilibrium, 1995) are studied. RESULTS: All patients improved significantly. In one of them treatment was repeated after 6 months. A number of patients with hearing improvement were observed. CONCLUSIONS: The use of combined dexamethasone may be useful to control vertigo due to MD, to avoid or to be a prior step to other more aggressive treatments.

Administration, Topical↗
PubMed2003

Results in split liver transplantation.

INTRODUCTION: The shortage in cadaveric grafts has prompted the development of alternative surgical techniques to expand the donor pool. OBJECTIVE: To evaluate the feasibility of split liver transplantation using an observational, retrospective, and longitudinal study. MATERIALS AND METHODS: Between April 1986 and October 2002 we performed 875 liver transplants. From April 1991 to date, we performed 18 split liver transplantations in patients of mean age 42.27+/-25.65 years; five children and 13 adults; and 83.3% women. Urgent transplants accounted for 38.9%. Mean patient weight was 52.29+/-20.87 kg. Ex situ splitting was performed in 33%. The mean cold ischemia time was 460+/-265.69 minutes with a mean warm time of 64.33+/-11.78 minutes. Mean consumption of packed blood was 5.59+/-4.87 units; of frozen fresh plasma, 11.56+/-7.42 units; and of platelets 4.89+/-4.99 units. RESULTS: After a mean follow-up of 10.83+/-12.51 months, 55.56% of the recipients are alive. Actuarial patient and graft survival rates at 1 year are 55.6% and 44.12%, respectively. Actuarial patient and graft survival rates at 1 year, excluding operative mortality were 77% and 68%, respectively. Actuarial patient and graft survival rates at 1 year, comparing urgent and elective transplantations are: 14.29 and 14%, respectively, for urgent cases and 90.91 and 90% for elective ones. Operative mortality was 16.6% while mortality during follow-up was 26.6%. The late complications included arterial thrombosis (n=2): of whom the first needed liver retransplantation 4 months after split liver transplantation; chronic rejection (n=2), recurrence of hepatitis (n=1). CONCLUSIONS: Split liver transplantation is a useful way to expand the graft pool and shows better results in elective liver transplantation.

Adult↗
PubMed2003

Live liver donation: a prospective analysis of exclusion criteria for healthy and potential donors.

INTRODUCTION: Living donor liver transplantation represents a controversial option to increase the donor pool. DESIGN: Prospective and descriptive clinical study. OBJECTIVE: (1) To identify risk factors (exclusion criteria) for live donation; (2) to determine the rate of recipients that benefit from a living donor. METHODS: Between May 1995 (first adult-to-adult living donor liver transplantation in Spain) and November 2002, we evaluated 74 healthy volunteers and performed 12 living donor liver transplants (no donor mortality). RESULTS: All actual donors and volunteers are alive and healthy. After a mean time of 3.2+/-0.5 weeks, 72% of potential donors were considered unsuitable for live donation. Exclusion criteria were grouped in three categories: (primary) donor safety reasons (68%); (secondary): ABO mismatch (17%) and (tertiary): cadaveric graft transplantation (15%). Consequently, just 43.7% of the recipients presenting to us with a potential living donor, did finally benefit from these organs. The mortality rate was 8.3% for 43 recipients presenting with a living donor in comparison to 15% for those who did not (321 recipients between May 1995 and November 2001). CONCLUSIONS: ALDLT can benefit a significant number of recipients on the waiting list (43.7% of those presenting with a donor). The most frequent exclusion criteria concern donor safety, namely, unsuspected chronic liver diseases and unsuspected thrombophilic disorders.

ABO Blood-Group System↗
PubMed2002

Double dimer peptide constructs are immunogenic and protective against Plasmodium falciparum in the experimental Aotus monkey model.

Multiple antigen peptide constructs (MAPs) have been used to obtain defined multimeric peptide molecules useful in the development of possible synthetic malaria vaccines. In this context, a method was developed, named double dimer constructs (DDCs), involving the direct synthesis of a dimeric peptide with a C-terminal cysteine. A tetrameric molecule was then obtained by oxidation of sulfhydryl groups. Dimer synthesis was optimized using a Fmoc/tBu strategy, dimers were purified by HPLC, oxidized with DMSO and characterized by HPLC and MALDI-TOF-MS. The tetramers or DDCs obtained by this method were used as immunogens in the search for a possible malaria vaccine. It was found that they were immunogenic in the experimental Aotus monkey model, and were able to induce protective immunity when challenged experimentally with a highly infective Plasmodium falciparum malaria strain.

Amino Acid Sequence↗
PubMed2002

Peripheral oxygen transport in skeletal muscle of Antarctic and sub-Antarctic notothenioid fish.

Transcellular oxygen flux was modelled mathematically in the aerobic skeletal muscles of perciform fish species living at widely different temperatures (Antarctica, sub-Antarctica and the Mediterranean Sea). Using structural data derived from stereological analysis of electron micrographs, mean fibre P(O(2)) was calculated on the basis of temperature-corrected rates of mitochondrial respiration and oxygen diffusion. The mean muscle fibre diameter (MFD) among Antarctic notothenioids was in the range 17-61 microm and mitochondrial volume density, Vv(mit,f), was 0.27-0.53, but capillary-to-fibre ratio varied only between 1.2 and 1.5. For a mean capillary P(O(2)) of 6 kPa, the model predicted a mean tissue P(O(2)) in the range 0.7-5.8 kPa at the estimated maximum aerobic capacity (M(O(2)max)). The lowest levels of tissue oxygenation were found in the pectoral muscle fibres of the icefish Chaenocephalus aceratus, which lacks the respiratory pigments haemoglobin and myoglobin. Red-blooded notothenioids found in the sub-Antarctic had a similar muscle fine structure to those caught south of the Antarctic Convergence, with an MFD of 20-41 microm and Vv(mit,f) of 0.27-0.33, resulting in an estimated mean P(O(2)) of 4-5 kPa at M(O(2)max). Mean tissue P(O(2)) in the sub-Antarctic icefish Champsocephalus esox, with greater MFD and Vv(mit,f), 56 microm and 0.51, respectively, was calculated to exceed 1 kPa at winter temperatures (4 degrees C), although oxidative metabolism was predicted to be impaired at the summer maximum of 10 degrees C. At the high end of the thermal range, related perciform species from the Mediterranean had a negligible drop in intracellular P(O(2)) across their small-diameter fibres, to a minimum of 5.4 kPa, comparable with that predicted for Trematomus newnesi from the Antarctic (5.6 kPa) with a similar MFD. These data suggest that, within a single phylogenetic group, integrative structural adaptations potentially enable a similar degree of tissue oxygenation over a 20 degrees C range of environmental temperature in the red-blooded notothenioids, and that this is compromised by the lack of respiratory pigments in the icefishes. The mean capillary radius was 1.5 times greater in the two icefish than in the other notothenioids, and the model simulations indicate that the evolution of wide-bore capillaries is essential to maintain tissue oxygenation in the absence of respiratory pigments.

Animals↗
PubMed2001

Role of two conserved cytoplasmic threonine residues (T410 and T412) in CD5 signaling.

CD5 is a transmembrane coreceptor that modulates activation and differentiation signals mediated by the Ag-specific receptor present on both T and B1a lymphocytes. CD5 lacks intrinsic catalytic activity, and its immunomodulatory properties result from intracellular interactions mediated by the CD5 cytoplasmic tail. The nature of these interactions is currently a matter of investigation. Here, we present a selective mutagenesis analysis of two conserved threonine residues (T410 and T412) located at the membrane-proximal cytoplasmic region of CD5. These residues are contained within consensus phosphorylation motifs for protein kinase C and are shown here to be critical for in vivo protein kinase C-mediated phosphorylation of CD5. Functional studies revealed that the integrity of T410 and T412 is also critical for CD5-mediated phosphatidylcholine-specific phospholipase C (PC-PLC) activation and phorbol ester-mediated inhibition of Ab-induced internalization of CD5. These results strongly argue in favor of a role for T410 and T412 in the signaling mediated by CD5.

Amino Acid Substitution↗
PubMed2001

Clinical and microbiological characteristics of 28 patients with Staphylococcus schleiferi infection.

The aim of this study was to analyse the clinical and microbiological characteristics of a series of patients with infection by Staphylococcus schleiferi. Seventy-one isolates were recovered from 36 patients between January 1993 and June 1999 at a tertiary care centre in northern Spain. There were 28 patients with well-documented clinical data. Infection was more frequent in men (89.3%), and more than half of the patients had some degree of immunosuppression, mainly malignant neoplasms. Infection was nosocomial in 22 cases and community-acquired in the remaining cases. Staphylococcus schleiferi was frequently associated with wound infections, mainly surgical-site infections, although unusual types of infections were detected. Infection-related mortality was low. This study highlights the importance of careful identification of Staphylococcus schleiferi in the clinical microbiology laboratory. Due to the documented association of Staphylococcus schleiferi with clinical infections in humans, any isolates of this organism should be assumed to be pathogenic, unless proven otherwise.

Adult↗
PubMed2001

High circulating levels of soluble scavenger receptors (sCD5 and sCD6) in patients with primary Sjögren's syndrome.

OBJECTIVE: To determine the existence of circulating levels of soluble scavenger receptors (sCD5 and sCD6) in patients with primary Sjögren's syndrome (SS), and to analyse the correlation with clinical and immunological features of SS. METHODS: Ninety consecutive patients with primary SS were studied. All patients fulfilled four or more of the European diagnostic criteria for SS. sCD5 and sCD6 levels were determined using a specific enzyme-linked immunosorbent assay (ELISA) developed in our laboratory. RESULTS: Detectable levels of sCD5 were found in 39 (43%) SS patients. The mean+/-standard error values of sCD5 were 3.5+/-0.5 ng/ml for patients with SS and 1.9+/-0.1 ng/ml for healthy blood donors (P<0.001). We found higher levels of sCD5 in patients with hypocomplementaemia (6.5 vs 3.5 ng/ml, P=0.03) and cryoglobulinaemia (6.9 vs 2.6 ng/ml, P=0.001). On the other hand, detectable levels of sCD6 were found in 60 (67%) SS patients. The mean+/-standard error values of sCD6 were 25.5+/-7.8 ng/ml in SS patients and 5.27+/-1.40 ng/ml in healthy blood donors (P=0.01). When the sCD6 levels were compared according to the presence or absence of immunological features, patients with cryoglobulinaemia showed higher levels of circulating sCD6 (77.3 vs 17 ng/ml, P=0.01) than those without cryoglobulinaemia. CONCLUSION: Patients with primary SS showed higher levels of circulating sCD5 and sCD6 when compared with controls. Moreover, the existence of some immunological features (hypocomplementaemia and cryoglobulinaemia) was associated with high levels of both soluble scavenger receptors. These facts may reflect an enhanced lymphocytic activation in patients with primary SS.

Adult↗
PubMed2001

[Behcet's disease: retrospective study].

BACKGROUND: Since the criteria for the diagnosis of Behçet's disease was established several isolated cases have been reported to the literature with clinical manifestations associated. We tried to analyze the clinical parameters associated to this disease in 24 patients in our hospital. METHODS: A retrospective analysis was made of the patients diagnosed of Behçet's disease at Hospital General of Valencia since 1990 to 2000. The diagnosis of Behçet's disease was made by the criteria of the International Study Group for Behçet disease. Data regarding personal, clinical manifestations and clinical course were collected. RESULTS: Of the 24 cases, fourteen (58%) were men and ten (42%) were women. The median of the diagnosed was 33 years. All of them had oral recidivant ulcers. The genital ulcers appeared in twenty (83%) cases. Thirteen cases (54%) had ocular manifestations, and the skin lesions appear in 10 cases (42%). We review other clinical manifestations associated to Behçet disease: articular clinical appear in 17 cases (70%), digestive manifestations in six cases (25%), neurological manifestations three cases (12%), vascular clinical two cases (8%). CONCLUSIONS: Our results are similar to the Mediterranean expression of Behçet's disease. We must study the clinical manifestations associated to this disease that are not include in the criteria of diagnosis.

Adult↗
PubMed2000

Genomic organization of the human CD5 gene.

CD5 is a member of the family of receptors which contain extracellular domains homologous to the type I macrophage scavenger receptor cysteine-rich (SRCR) domain. Here, we compare the exon/intron organization of the human CD5 gene with its mouse homologue, as well as with the human CD6 gene, the closest related member of the SRCR superfamily. The human CD5 gene spans about 24.5 kb and consists of at least 11 exons. These exons are conserved in size, number, and structure in the mouse CD5 homologue. No evidence for the biallelic polymorphism reported in the mouse could be found among a population of 100 individuals of different ethnic origins. The human CD5 gene maps to the Chromosome (Chr) 11q12.2 region, 82 kb downstream from the human CD6 gene, in a head-to-tail orientation, a situation which recalls that reported at mouse Chr 19. The exon/intron organization of the human CD5 and CD6 genes was very similar, differing in the size of intron 1 and the number of exons coding for their cytoplasmic regions. While several isoforms, resulting from alternative splicing of the cytoplasmic exons, have been reported for CD6, we only found evidence of a cytoplasmic tailless CD5 isoform. The conserved structure of the CD5 and CD6 loci, both in mouse and human genomes, supports the notion that the two genes may have evolved from duplication of a primordial gene. The existence of a gene complex for the SRCR superfamily on human Chr 11q (and mouse Chr 19) still remains to be disclosed.

Alternative Splicing↗