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E Sola

Publications and source records attributed to E Sola.

At least 19 recordsLinked to original sources
PubMed2006

Multivesicular release at developing Schaffer collateral-CA1 synapses: an analytic approach to describe experimental data.

We developed and analytically solved a simple and general stochastic model to distinguish the univesicular from the multivesicular mode of glutamate release. The model solution gives analytical mathematical expressions for average values of quantities that can be measured experimentally. Comparison of these quantities with the experimental measures allows one to discriminate the release mode and to determine the most probable values of model parameters. The model has been validated at glutamatergic CA3-CA1 synapses in the hippocampus from newborn (P1-P5 old) rats. Our results strongly support a multivesicular type of release process requiring a variable pool of immediately releasable vesicles. Moreover, computing quantities that are functions of the model parameters, the mean amplitude of the synaptic response to the release of a single vesicle (q) was estimated to be 5-10 pA, in very good agreement with experimental findings. In addition a multivesicular type of release was supported by the following experimental evidences: 1) a high variability of the amplitude of successes, with a coefficient of variation ranging from 0.12 to 0.73; 2) an average potency ratio a2/a1 between the second and first response to a pair of stimuli >1; and 3) changes in the potency of the synaptic response to the first stimulus when the release probability was modified by increasing or decreasing the extracellular calcium concentration. Our results indicate that at Schaffer collateral-CA1 synapses of the neonatal rat hippocampus a single action potential may induce the release of more than one vesicle from the same release site.

Action Potentials↗
PubMed2006

Polyomavirus BK nephropathy: the effect of an early diagnosis on renal function or graft loss.

Polyomavirus BK nephropathy is a new complication among renal transplant patients. We studied 664 cadaver renal transplant recipients from February 1998 to February 2005, divided into two periods: 448 (group A, February 1998 to July 2003) and 176 (group B, August 2003 to February 2005). Twenty patients (3%) developed biopsy-confirmed polyomavirus BK nephropathy; 13 (2.9%) in group A after worsening renal function and 7 (3.9%) in group B after a prospective cytologic study in urine, examining for decoy cells, and a qualitative polymerase chain reaction (PCR) assay in urine and blood. The mean time to diagnosis was higher among group A (15.0 +/- 1.6 versus 7.2 +/- 4.0 months), as was the serum creatinine (2.5 +/- 0.7 versus 2.0 +/- 0.6 mg/dL). After 12 months the serum creatinine was 2.7 +/- 1.3 versus 1.7 +/- 0.2 mg/dL, respectively. Poor prognostic factors were a persistently positive PCR in blood and viral inclusions in the control biopsy.

Adult↗
PubMed2006

Expanded criteria donors for kidney transplantation: quality control and results.

Although the number of kidneys from expanded criteria deceased donors (ECDs) is growing in most transplant centers, the limits for acceptance of these kidneys and the safety standards have still not been fully established. We evaluated 342 kidney transplants performed between January 1999 and December 2004. In 77 (22.5%) of these, the kidneys were from ECDs, that is, donors age >60 years and with one of the following characteristics: hypertension, death due to cerebrovascular accident (CVA) or glomerular filtration rate (GFR) <70 mL/min. The results of the ECD transplants were compared with 265 transplants during the same period from standard donors (SDs), that is, donors age <60 years and GFR > 70 mL/min. All the ECD kidneys underwent biopsy and were accepted for transplantation only if the score was <7. The ECDs (66.5 +/- 4.3 years) in comparison with the SDs (48.0 +/- 16.0 years) had a greater frequency of death due to CVA (94.8% vs 49.8%) and a lower GFR (80.4 +/- 25.0 vs 111 +/- 41.6 mL/min; P < .05). Of the ECDs, 97.4% had a history of hypertension versus 24.3% of the SDs. Kidney biopsies were performed in 116 SD kidneys because the donor age was >55 years or there was a history of hypertension. The median score for the kidney biopsies of the ECD kidneys was 3 versus 2 for the SD kidneys. Graft survival was not significantly different until the fifth year. The GFR at 12 months was significantly different (SDs, 58.0 +/- 22.7 vs ECDs, 48.9 +/- 16.5 mL/min; P < .05). Although the GFR in the ECD kidneys was lower than that of the SD kidneys, it could still be adequate for recipients older than 50 years of age. Accordingly, the acceptance criteria for ECD kidneys based mainly on the kidney biopsy score and donor GFR benefit the recipients.

Aged↗
PubMed2006

Pulmonary toxicity associated with sirolimus treatment in kidney transplantation.

INTRODUCTION: An important side effect of sirolimus, a drug often used in organ transplantation, is pulmonary toxicity. MATERIALS AND METHODS: We present five kidney transplant patients who developed this toxicity associated with sirolimus. All underwent chest radiography computed tomography, fiberoptic bronchoscopy with bronchoalveolar lavage (BAL), microbiological studies of the bronchial aspirate, blood, and sputum, and cytomegalovirus (CMV) polymerase chain reaction (PCR) in blood as well as two had transbronchial biopsies. RESULTS: All five were men of mean age 54.8 +/- 10.3 years. In two sirolimus formed part of de novo therapy, and three were converted from calcineurin inhibitors. The mean treatment time was 16.6 +/- 13.7 months, with trough levels of 11.3 +/- 3 ng/mL. The patients presented with fever, cough, dyspnea, anemia, and dyslipidemia. The radiological pattern was diffuse alveolointerstitial (n = 2), or bilateral basal interstitial (n = 2), or bilateral basal alveolar (n = 1). The cell count in the BAL was 95% to 99% macrophages. In two patients cultures for bacteria were positive: Hemophilus and Pseudomonas. Tests for fungi, mycobacteria, pneumocystis, and legionella, as well as PCR for CMV were all negative. Transbronchial biopsy yielded insufficient material in one patient and a deposit of fibrinoid material and nonnecrotizing granuloma in the other. Antibacterial therapy was started, three with cotrimoxazole and two with ganciclovir, with no response. The respiratory symptoms improved after withdrawal of sirolimus (mean, 2.4 +/- 1.5 days). The mean hospital stay was 19.8 +/- 14.1 days. CONCLUSION: Pulmonary toxicity due to sirolimus should be included in the differential diagnosis of kidney transplant patients who display signs of interstitial pneumonia. Its diagnosis is difficult requiring exclusion of other pulmonary diseases. Resolution of the symptoms was quick after suspension of the drug.

Adult↗
PubMed2006

Posttransplant lymphoproliferative disease: a series of 23 cases.

Posttransplant lymphoproliferative disease (PTLD) is a rare but clinically important disorder due to its increasing incidence and its impact on renal function and the life of the patient. Between 1979 and 2005, this center performed 1614 kidney transplants, and 23 patients had PTLD. We undertook a retrospective study, analyzing risk factors, presentation, and evolution of the disorder. The most common clinical presentation was fever and adenopathy. All cases except one received calcineurin inhibitors, and nine were treated with monoclonal or polyclonal antibodies. Serology for Epstein Barr virus (EBV) was negative in nine patients at the time of transplant, and in five it became positive on diagnosis of PTLD. The predominant disorder was non-Hodgkin's lymphoma (NHL), either polymorphous (n = 11) or monomorphous (n = 7). The base therapy consisted of reducing or suspending calcineurin inhibitors and the addition of sirolimus and antivirals. Three patients received rituximab, and five chemotherapy. The disease progressed in 36% of the polymorphous NHL, in 67% of the monomorphous, and in 100% of the Hodgkin's lymphoma, whereas 10 patients had remission. Renal function worsened on diagnosis in eight patients, and the graft was infiltrated in five (confirmed histologically). Five patients lost the graft and 12 died; six due to infection and five due to PTLD. Survival was worse in the patients aged over 55 years. We conclude that in most cases EBV is positive on diagnosis of the PTLD, an age older than 55 years affords a poor prognosis, and lymphocyte infiltration of the graft is common, as is worsening renal function.

Humans↗
PubMed2006

Anterior uveitis associated with treatment with intravenous cidofovir in kidney transplant patients with BK virus nephropathy.

BACKGROUND: Polyomavirus-associated nephropathy (PVAN) is an important cause of kidney dysfunction and graft loss. Different treatment regimens have been used, including low-dose intravenous cidofovir. Anterior uveitis, a complication of this treatment, has been reported after its use in patients with cytomegalovirus-associated retinitis. We analyzed the incidence and associated risk factors for this disorder in patients with PVAN. PATIENTS AND METHODS: The study included 14 kidney-transplant patients who had received low doses of cidofovir after being diagnosed with PVAN. RESULTS: Five (35%) patients developed an episode of anterior uveitis. The mean number of cidofovir doses given was 6.8 +/- 1.6 as compared with 9.1 +/- 2.1 in patients who did not develop the disease. Creatinine clearance at diagnosis of the nephropathy and after terminating treatment was lower in the uveitis patients, who had a graft survival of 40% versus 100% in the patients who did not develop eye involvement. Treatment was suspended in the affected patients, with complete resolution in 80% after the administration of topical corticoids and cycloplegics. CONCLUSIONS: Anterior uveitis secondary to low-dose treatment with cidofovir is a common complication in patients with PVAN and is associated with the degree of renal involvement. In the absence of larger studies, cidofovir should be used with caution in patients with creatinine clearance below 30 mL/min.

Adult↗
PubMed2006

[Renal transplantation in HIV-infected patients in Spain].

HIV infection has experienced dramatic improvement in morbidity and mortality with the highly active antiretroviral therapy (HAART). This prompted a reevaluation of organ-solid transplantation as a treatment option for HIV-infected patients. Some trials in the United States have shown that one- and 2-year graft and patient survival is comparable to HIV-negative transplant population. In Europe the experience is still scarce. The aim of this study is to analyse the outcome and the clinical characteristics of HIV-infected patients who received kidney transplantation in Spain in the HAART era. Ten patients were transplanted in our country since 2001. Only one patient was black. The main cause of end-stage renal disease reported was glomerulonephritis. Six of the recipients were coinfected by hepatitis C virus. Inclusion criteria included undetectable HIV viral load and CD4 counts greater than 200/pL. Immunosuppression consisted of steroids, tacrolimus and mycophenolate mofetil, with antibody induction in 4 cases. The median and mean follow-up was 11 and 16.3+/-15.6 (3-46) months, respectively. One recipient lost his graft because of early renal venous thrombosis. The remaining patients are functioning graft with mean serum creatinina level of 1.5 +/- 0.5 mg/dl. Biopsy-proven acute rejection was diagnosed in 4 recipients and was reversed in all cases with antirejection treatment. The plasma HIV RNA levels have remained controlled and CD4 counts have been stable in excess of 200 cell/microL. None of patients have developed AIDS complications. Recipients receiving protease inhibitor-based HAART regimens required significant dosing modification to maintain appropriate tacrolimus levels. Our results show that renal transplantation can be a safe and effective treatment in select HIV-infected patients. Like other series, the acute rejection rate was higher than in non-HIV recipients. The reasons of this rejection incidence remain unknown.

Adult↗
PubMed2005

Pancreas islet transplantation in patients with type 1 diabetes mellitus after kidney transplantation.

Diabetic patients with end-stage renal disease have a high mortality rate. A combined kidney-pancreas transplant is associated with greater life expectancy. Pancreas islet transplantation is an alternative involving a lower degree of morbidity. We present two patients, of 41 and 37 years of age, with a long history of diabetes mellitus (C-peptide negative), both with a previous kidney transplant, who had been treated with 22 and 28 U of insulin/d, respectively. Both patients had frequent episodes of unawareness hypoglycemia. Pancreatic islets were infused to a total of 7809 and 19,180 IE/kg, respectively. Basal posttransplant C peptide levels were 2.9 and 1.3 ng/mL. After the implant, one patient required occasional doses of insulin, and the other patient more than 50% reduced dose. After the first implant neither patient had any episodes of unawareness hypoglycemia. HbA1c at 4 months were 6.2% and 6.9%. There were no transplant-related complications.

Adult↗
PubMed2004

[De novo hemolytic uremic syndrome in a kidney-pancreas recipient in the postoperative period].

Among the numeruos adverse side effects of tacrolimus (TAC), de novo thrombotic microangiopathy stands out as an infrecuente but severe complication. Renal dysfunction is the only alteration that should lead to suspicion of thrombotic microangiopathy, because the clinical features of intravascular hemolysis are not always found. The definitive diagnosis can usually be made with kidney biopsy. Patientes with TAC induced thrombotic microangiopathy usually promptly recover after treatment withdrawal or reduction in the dose of TAC and a short course of plasma therapy, but the risk of rejection increases. Switching from TAC to cyclosporine has also been tried with resolution of the hemolysis but thrombotic microangiopathy has been noted with both and this condition may later recur. We present a 29-year-old man who received a kidney-pancreas transplant for end-stage diabetic nephropathy. After initial induction with basiliximab, the immunosuppression consisted of prednisone, tacrolimus and mycophenolate mofetil. Twenty four days posttransplantation his renal function declined with a peak creatine level of 2.35 mg/dl. Laboratory studies showed thrombocytopenia and features of intravascular hemolysis. TAC associated hemolytic uremic syndrome was suspected and drug was immediately stopped and converted to sirolimus. Also he was treated with plasma infusion. The allograft biopsy showed focal glomerular and arteriolar acute thrombosis without evidence of rejection. Our experience demostrate that switching from tacrolimus to sirolimus could be an adecuate strategy for patients who develop FK506-associated de novo thrombotic microangiopathy without increase risk of acute rejection.

Adult↗
PubMed2001

Transmission of trans effects in dinuclear complexes.

The substitution of a terminal hydride ligand in the complexes [Ir(2)(mu-H)(mu-Pz)(2)H(3)(L)P(i)Pr(3))(2)] (L = NCCH(3) (1) or pyrazole (3)) by chloride provokes a significant change in the lability of the L ligand, despite the fact that the substituted hydride and the L ligand lie in opposite extremes of the diiridium(III) complexes. Detailed structural studies of complex 3 and its chloro-trihydride analogue [Ir(2)(mu-H)(mu-Pz)(2)H(2)Cl(HPz)(P(i)Pr(3))(2)] (4) have shown that this behavior is a consequence of the transmission of ligand trans effects from one extreme of the molecule to the other, with the participation of the bridging hydride. Extended Hückel calculations on model diiridium complexes have suggested that such trans effect transmissions are due to the formation of molecular orbitals of sigma symmetry extended along the backbones of the complexes. This is also an expected feature for metal-metal bonded complexes. The feasibility of the transmission of ligand trans effects and trans influences through metal-metal bonds and its relevance to the understanding of both the reactivity and structures of metal-metal bonded dinuclear compounds have been substantiated through structural studies and selected reactions of the diiridium(II) complexes [Ir(2)(mu-1,8-(NH)(2)naphth)I(CH(3))(CO)(2)(P(i)Pr(3))(2)] (isomers 6 and 7) and their cationic derivatives [Ir(2)(mu-1,8-(NH)(2)naphth)(CH(3))(CO)(2)(P(i)Pr(3))(2)](CF(3)SO(3)) (isomers 8 and 9).

Journal Article↗
PubMed2000

Key factors determining the course of methyl iodide oxidative addition to diamidonaphthalene-bridged diiridium(I) and dirhodium(I) complexes.

The course of methyl iodide oxidative addition to various nucleophilic complexes, [Ir2(mu-1,8-(NH)2naphth)(CO)2(PiPr3)2] (1), [IrRh(mu-1,8-(NH)2naphth)(CO)2(PiPr3)2] (2), and [Rh2(mu-1,8-(NH)2naphth)(CO)2(PR3)2] (R = iPr, 3; Ph, 4; p-tolyl, 5; Me, 6), has been investigated. The CH3I addition to complex 1 readily affords the diiridium(II) complex [Ir2(mu-1,8-(NH)2naphth)I(CH3)(CO)2(PiPr3)2] (7), which undergoes slow rearrangement to give a thermodynamically stable stereoisomer, 8. The reaction of the Ir-Rh complex 2 gives the ionic compound [IrRh(mu-1,8-(NH)2naphth)(CH3)(CO)2(PiPr3)2]I (10). The dirhodium compounds, 3-5, undergo one-center additions to yield acyl complexes of the formula (Rh2(mu-1,8-(NH)2naphth)I(COCH3)(CO)(PR3)2] (R = iPr, 12; Ph, 13; p-tolyl, 14). The structure of 12 has been determined by X-ray diffraction. Further reactions of these Rh(III)-Rh(I) acyl derivatives with CH3I are productive only for the p-tolylphosphine derivative, which affords the bis-acyl complex [Rh2(mu-1,8-(NH)2naphth)(CH3CO)2I2(P(p-tolyl)3)2] (15). The reaction of the PMe3 derivative, 6, allows the isolation of the bis-methyl complex [Rh2(mu-1,8-(NH)2naphth)(mu-I)(CH3)2(CO)2(PMe3)2]I (16a), which emanates from a double one-center addition. Upon reaction with methyl triflate, the starting materials, 1, 2, 3, and 6, give the isostructural cationic methyl complexes 9, 11, 17, and 18, respectively. The behavior of these cationic methyl compounds toward CH3I, CH3OSO2CF3, and tetrabutylamonium iodide is consistent with the role of these species as intermediates in the SN2 addition of CH3I. Compounds 18 and 17 react with an excess of methyl triflate to give [Rh2(mu-1,8-(NH)2naphth)(mu-OSO2CF3)(CH3)2(CO)2(PMe3)2][CF3SO3] (19) and [Rh2(mu-1,8-(NH)2naphth)(OSO2CF3)(COCH3)(CH3)(CO)(PiPr3)2][CF3SO3] (20), respectively. Upon treatment with acetonitrile, complexes 17 and 18 give the isostructural cationic acyl complexes [Rh2(mu-1,8-(NH)2naphth)(COCH3)(NCCH3)(CO)(PR3)2][CF3SO3] (R = iPr, 21; Me, 22). A kinetic study of the reaction leading to 21 shows that formation of these complexes involves a slow insertion step followed by the fast coordination of the acetonitrile. The variety of reactions found in this system can be rationalized in terms of three alternative reaction pathways, which are determined by the effectiveness of the interactions between the two metal centers of the dinuclear complex and by the steric constraints due to the phosphine ligands.

Journal Article↗
PubMed2000

Evidence for a dinuclear mechanism in alkyne hydrogenations catalyzed by pyrazolate-bridged diiridium complexes

The products obtained from the sequential reaction of [Ir2(mu-H)(mu-Pz)2H3(NCCH3)(PiPr3)2] (1) with diphenylacetylene and their subsequent reactions with hydrogen have been investigated in order to deduce the mechanisms operating in the hydrogenation reactions catalyzed by 1. The reaction of 1 with an excess of diphenylacetylene gives cis-stilbene and [Ir2(mu-H)(mu-Pz)2-[eta1-C6H4-2-[eta1-(Z)-C=CHPh]]((Z)-C(Ph) =CHPh](NCCH3)(PiPr3)2] (2), the structure of which has been determined by X-ray diffraction. The formation of 2 involves the intermediate species [Ir2(mu-H)(mu-Pz)2H2((Z)-C(Ph)=CHPh](NCCH3)-(PiPr3)2](3),[Ir2(mu-H)(mu-Pz)2H[(Z)-C(Ph)=CHPh]2(NCCH3)(PiPr3)2] (4), and [Ir2(mu-H)(mu-Pz)2H[eta1-C6H4-2-[eta1-(Z)-C=CHPh](NCCH3)(PiPr3)2] (5), which have been isolated and characterized. These three complexes react with hydrogen to give cis-stilbene and 1 and are possible intermediates of the diphenylacetylene hydrogenation under catalytic conditions. Nevertheless, the rate of formation of 5 is very slow compared with the rate of catalytic hydrogenation, which excludes its participation during catalysis. Compound 2 also reacts with hydrogen in benzene, but in this case the hydrogenation gives 1,2-diphenylethane as the sole organic product. The course of this reaction in acetone has been investigated, and deuteration experiments were carried out. The formation of [Ir2(mu-H)(mu-Pz)2H[eta1-C6H4-2-[eta1-(Z)-C=CHPh]](OC(CD3)2)(PiPr3)2] (6) and [Ir2(mu-H)(mu-Pz)2H[eta1-C6H4-2-[eta1-(Z)-C-CHPh]](NCCH3)(PiPr3)2] (7) was observed under these conditions. The experimental evidence obtained supports two alternative mechanisms for the alkyne hydrogenation catalyzed by 1, one of them being dinuclear and the other mononuclear. The experimental data suggest that the former is favored.

Journal Article↗
PubMed1996

[Cryopreservation of embryos in an in vitro fertilization program(IVN-ET)--preliminary results].

The authors present preliminary results of cryopreservation of embryos in IVF-ET programme in the Institute of Obstetrics and Gynecology in Białystok. The method of slow cooling embryos with 1, 2 propanediol and saccharose were used. In the group of 136 patients with excess embryos after the transfer of two fresh embryos 29 pregnancies (21.3%) were obtained. After the transfer of frozen/thawed embryos up till now 5 pregnancies have been obtained (one child born, 3 pregnancies ongoing, 1 abortion).

Cryopreservation↗
PubMed1996

["Long protocol" for ovarian stimulation using D-Trp6 LHRH (Triptorelin Depot) and menopausal gonadotropin in the IVF-ET program].

39 patients (age 35-40, anovulation, previous failures in the IVF-ET programme) were superovulated using GnRH analogue (Decapeptyl-Depot) in the long protocol and hMG 97 embryos were transferred and 109 were cryopreserved. The clinical pregnancy and implantation rates were 31.6% and 13.4%. The long protocol gives better results in the IVF-ET programme but increases the costs of treatment.

Adult↗