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Biomedical subjects

M Carrera

Publications and source records attributed to M Carrera.

At least 37 records · Page 2Linked to original sources
PubMed2001

Supported discharge shortens hospital stay in patients hospitalized because of an exacerbation of COPD.

This prospective, controlled, but not formally randomized study investigates the feasibility and efficiency of an alternative to standard hospitalization for patients with exacerbated chronic obstructive pulmonary disease (COPD), based upon supported discharge with nurse supervision at home. Over a 12-month period, emergency physicians, not directly involved in the study, admitted 205 patients with exacerbated COPD to the authors' respiratory unit. Patients were included in the supported discharge group (n=105) if they voluntarily chose to participate in the programme and lived in the city of Palma de Mallorca (where adequate home support could be provided). Patients not fulfilling these criteria (mainly residents outside the city) served as controls (n=100). Inpatient treatment was standardized in all patients and included oxygen therapy, bronchodilators, antibiotics and steroids. Both groups were comparable in terms of age (mean +/- SD: 70 +/- 10 versus 65 +/- 11 yr for supported discharge and control group, respectively), severity of airflow obstruction (forced expiratory volume in one second 45 +/- 18% reference versus 46 +/- 19% ref.), comorbidity and socioeconomic status. Length of hospital stay (LOS) in the supported discharge group was shorter (5.9 +/- 2.8 versus 8.0 +/- 5.1 days, p < 0.001). After discharge, a respiratory nurse visited supported discharge patients at home during 7.3 +/- 3.8 days. Only one patient (1%) required hospital readmission during this period of time. The reduced LOS resulted in a lower utilization of hospital beds at any given point in time throughout the study period. Within the framework and potential limitations of this study, the results indicate that the supported discharge programme in Spain: 1) allows a significant reduction in the length of hospital stay of patients hospitalized because of an exacerbation of chronic obstructive pulmonary disease; 2) does not result in an inappropriately increased rate of hospital readmissions; and 3) reduces the utilization of hospital resources.

Aged↗
PubMed2001

Hepatitis C virus infection and de novo glomerular lesions in renal allografts.

In the present study we examine whether hepatitis C virus (HCV) infection status influences glomerular pathologic findings in renal allografts and its effect on graft outcome. Renal allograft biopsies performed between January 1991 and June 1999 were considered. Exclusion criteria were insufficient sample, unknown HCV serological status at time of biopsy and final diagnosis of acute rejection. Light microscopy and immunofluorescence studies were performed on all biopsies. According to a predefined protocol, electron microscopy was carried out. Of 138 eligible renal allograft biopsies, 42 fulfilled at least one exclusion criterion. Of 96 biopsies selected for the study, 44 (45.8%) were from HCV-positive and 52 from HCV-negative recipients. Renal biopsy was performed 74 +/- 55 and 60 +/- 39 months after transplantation in HCV-positive and HCV-negative groups, respectively (p = 0.12). Of 44 HCV-positive biopsies, 20 (45.4%) showed membranoproliferative glomerulonephritis (MPGN) (16 type I and 4 type III). Conversely, in HCV-negative biopsies there were only three cases of MPGN (2 type I and 1 type III). De novo membranous GN (MGN) was diagnosed in 8/44 (18.2%) HCV-positive and in 4/52 (7.7%) HCV-negative cases. The prevalence of chronic transplant glomerulopathy was similar in HCV-positive and HCV-negative groups (11.4% and 11.5%, respectively). The prognosis of de novo GN (either MPGN or MGN) was worse in HCV-positive than in HCV-negative recipients (relative risk 4.89; 95% confidence interval, 1.15-20.69; p = 0.03). By multivariate analysis, HCV-positive serology infection was the only independent predictor of graft loss (relative risk 2.64; 95% confidence interval, 1.35-5.17; p = 0.005). In diagnostic renal allograft biopsies the presence of de novo immune-mediated glomerulonephritis, especially type I MPGN, is strongly associated with HCV infection and results in accelerated loss of the graft.

Adult↗
PubMed2000

Heterogeneity for mutations in the CFTR gene and clinical correlations in patients with congenital absence of the vas deferens.

Congenital absence of the vas deferens (CAVD) is a heterogeneous disorder, largely due to mutations in the cystic fibrosis (CFTR) gene. Patients with unilateral absence of the vas deferens (CUAVD) and patients with CAVD in association with renal agenesis appear to have a different aetiology to those with isolated CAVD. We have studied 134 Spanish CAVD patients [110 congenital bilateral absence of the vas deferens (CBAVD) and 24 CUAVD], 16 of whom (six CBAVD, 10 CUAVD) had additional renal anomalies. Forty-two different CFTR mutations were identified, seven of them being novel. Some 45% of the CFTR mutations were specific to CAVD, and were not found in patients with cystic fibrosis or in the general Spanish population. CFTR mutations were detected in 85% of CBAVD patients and in 38% of those with CUAVD. Among those patients with renal anomalies, 31% carried one CFTR mutation. Anomalies in seminal vesicles and ejaculatory ducts were common in patients with CAVD. The prevalence of cryptorchidism and inguinal hernia appeared to be increased in CAVD patients, as well as nasal pathology and frequent respiratory infections. This study confirms the molecular heterogeneity of CFTR mutations in CAVD, and emphasizes the importance of an extensive CFTR analysis in these patients. In contrast with previous studies, this report suggests that CFTR might have a role in urogenital anomalies.

Abnormalities, Multiple↗
PubMed2000

Hepatocellular carcinoma in a non-cirrhotic liver. Two case reports and literature review.

Hepatocellular carcinoma (HCC) is closely associated with cirrhosis, but it also develops, although much less frequently, in a non-cirrhotic liver. It is suspected that hepatocellular carcinoma has a different etiology when associated and not associated with chronic liver disease. We report two cases of patients with hepatocellular carcinoma that developed in a non-cirrhotic liver. In the first case we describe an incidental liver nodular lesion containing multiple foci of HCC including pseudogland or trabecular formation and areas of sclerosis. The non-cancerous parenchyma of the liver was histologically unremarkable except for mild fatty changes of hepatocytes and minimal dysplasia. The second case describes a combined hepatocellular carcinoma and cholangiocellular carcinoma (CCC) (mixed carcinoma) in a patient who was serologically negative for both hepatitis B and C viruses. The adjacent liver parenchyma showed mild piecemeal necrosis and mild lobular activity compatible with chronic viral hepatitis, but cirrhosis was not established. This case appears to indicate that mixed type carcinoma can develop in a non-cirrhotic liver, with CCC being far more dominant than HCC; such a finding is extremely unusual, based on previously published reports.

Aged↗
PubMed2000

Management strategies in resection for carcinoma of the hepatic duct confluence: how to increase the resectability rate. Our experience and literature review.

The resectability rate of hilar bile duct carcinoma is reported to be variable and to inversely correlate with the size of the associated liver resection. In an attempt to reduce the risk of postoperative liver failure, the induction of a hypertrophy of remnant liver by preoperative portal vein embolization (PVE) has been proposed. We hereby analyse the results and the technical aspects of this procedure along with our personal experience.

Bile Duct Neoplasms↗
PubMed1999

[The results of the operation of a monitoring unit for home oxygen therapy].

OBJECTIVE: This study aims to a) analyze the prevalence of domiciliary oxygen therapy (DOT) in Mallorca, b) evaluate the cost effectiveness of the DOT monitoring unit, and c) determine the survival of patients with chronic obstructive pulmonary disease who are presently receiving DOT. METHOD: When the DOT unit was created in April 1994, the situation of all patients receiving DOT in Mallorca was assessed in a transversal study. Over the next three years, these patients were reassessed regularly and all new prescriptions were evaluated (longitudinal study). RESULTS: Before the unit began work, DOT was prescribed for 71 out of 100,000 inhabitants. DOT was withdrawn from 31% of patients assessed in the transversal study. By the end of the longitudinal study, DOT was being prescribed at a rate of 56 times per 10,000 inhabitants. The activities of the DOT unit brought about annual savings of approximately 38 million pesetas. The number of patients with liquid oxygen and concentrators increased such that the latter has become the main delivery system. The survival of COPD patients with DOT in this study seems to be longer than report. CONCLUSIONS: a) The prevalence of DOT use in Mallorca before the DOT unit began operating was too high. b) The cost effectiveness of DOT monitoring is positive because DOT use has been optimized and significant savings have ensued (= 38 millions pesetas/year). c) The survival of COPD patients receiving DOT at present appears better than that reported in the literature, possibly related to the greater efficacy of modern treatment.

Aged↗
PubMed1999

Oxygen therapy during exacerbations of chronic obstructive pulmonary disease.

Venturi masks (VMs) and nasal prongs (NPs) are widely used to treat acute respiratory failure (ARF) in chronic obstructive pulmonary disease (COPD). In this study, these devices were compared in terms of their potentiality to worsen respiratory acidosis and their capacity to maintain adequate (> 90%) arterial oxygenation (Sa,O2) through time (approximately 24 h). In a randomized cross-over study, 18 consecutive COPD patients who required hospitalization because of ARF were studied. After determining baseline arterial blood gas levels (on room air), patients were randomized to receive oxygen therapy through a VM or NPs at the lowest possible inspiratory oxygen fraction that resulted in an initial Sa,O2 of > or = 90%. Arterial blood gas levels were measured again 30 min later (on O2), and Sa,O2 recorded using a computer during the subsequent approximately 24 h. Patients were then crossed-over to receive O2 therapy by means of the alternative device (NPs or VM), and the same measurements obtained again in the same order. It was observed that both the VM and NPs improved arterial oxygen tension (p<0.0001) to the same extent (p=NS), without any significant effect upon arterial carbon dioxide tension or pH. However, despite this adequate initial oxygenation, Sa,O2 was < 90% for 3.7+/-3.8 h using the VM and for 5.4+/-5.9 h using NPs (p<0.05). Regression analysis showed that the degree of arterial hypoxaemia (p<0.05) and arterial hypercapnia (p<0.05) present before starting O2 therapy and, particularly, the initial Sa,O2 achieved after initiation of O2 therapy (p<0.0001) enabled the time (in h) that patients would be poorly oxygenated (Sa,O2 < 90%) on follow-up to be predicted. These findings suggest that, in order to maintain an adequate (> 90%) level of arterial oxygenation in patients with chronic obstructive pulmonary disease and moderate acute respiratory failure: 1) the initial arterial oxygen saturation on oxygen should be maximized whenever possible by increasing the inspiratory oxygen fraction; 2) this strategy seems feasible because neither the VM nor NPs worsen respiratory acidosis significantly; and 3) the Venturi mask (better than nasal prongs) should be recommended.

Acidosis, Respiratory↗
PubMed1999

Long-term effects of cyclosporine A in Alport's syndrome.

BACKGROUND: In 1991, our initial results of cyclosporine A (CsA) administration in eight patients with Alport's syndrome were published. A significant decrease in or disappearance of proteinuria and apparently good tolerance to CsA were observed in all patients. METHODS: CsA administration has been maintained in these eight patients with the aim of obtaining further information about the clinical course of the disease. The ages of these eight patients currently range from 15 to 27 years, and the mean duration of treatment is from 7 to 10 years (x = 8.4 years). RESULTS: Renal function has remained stable, with no evaluable changes in serum creatinine levels compared with pre-CsA treatment values. Proteinuria in all patients has either remained negative or are values far lower than pretreatment levels. A second renal biopsy was performed in all patients after five years of CsA administration. No aggravation of the lesion present at the first biopsy or lesions typical of cyclosporine intoxication was observed. CONCLUSIONS: After a mean duration of 8.4 years and with no deterioration in renal function, we found possible beneficial effects of the continued treatment of CsA in patients with Alport's syndrome who present evidence of progression to renal insufficiency.

Adolescent↗
PubMed1999

Patients with obstructive sleep apnea exhibit genioglossus dysfunction that is normalized after treatment with continuous positive airway pressure.

Obstructive sleep apnea syndrome (OSAS) is characterized by repetitive episodes of pharyngeal closure during sleep. The pathogenesis of OSAS is unclear. We hypothesized that the genioglossus (GG), the most important pharyngeal dilator muscle, would be abnormal in patients with OSAS. Further, because treatment with continuous positive airway pressure (CPAP) is very effective clinically in these patients, we investigated the effects of CPAP upon the structure and function of the GG. We studied 16 patients with OSAS (nine of them at diagnosis and seven after having been under treatment with CPAP for at least 1 yr) and 11 control subjects in whom OSAS was excluded clinically. A biopsy of the GG was obtained in each subject, mounted in a tissue bath, and stimulated through platinum electrodes. The following measurements were obtained: maximal twitch tension, contraction time, half-relaxation time, the force-frequency relationship, and the response to a fatiguing protocol. The percentage of type I ("slow twitch") and type II ("fast twitch") fibers was also quantified. Patients with OSAS showed a greater GG fatigability than did control subjects (ANOVA, p < 0.001). Interestingly, this abnormality was entirely corrected by CPAP. Likewise, the percentage of type II fibers was significantly higher in patients with OSAS (59 +/- 4%) than in control subjects (39 +/- 4%, p < 0.001) and, again, these structural changes were corrected by CPAP (40 +/- 3%, p < 0.001). These results show that the function and structure of the GG is abnormal in patients with OSAS. Because these abnormalities are corrected by CPAP, we suggest that they are likely a consequence, not a cause, of the disease.

Humans↗
PubMed1999

Confirmation of diagnosis in preimplantation genetic diagnosis (PGD) through blastocyst culture: preliminary experience.

Three cases of preimplantation genetic diagnosis (PGD) (two for sexing and one for aneuploidy screening) are presented. Embryo biopsy was performed at day 3 and diagnosis was established with fluorescent in situ hybridization (FISH). Embryos not used for replacement were cultured in sequential media for blastocyst development. Blastocyst rate was 39.3 per cent. Confirmations of diagnosis were established with FISH in blastocysts and arrested embryos. Mosaicism was observed in 7/8 blastocysts (mean number of cells analysed: 55.5) and 5/8 arrested embryos. The percentage of abnormal cells was 17.1 per cent for blastocysts and 54 per cent for arrested embryos. Polypoid cells were observed in 4/8 blastocysts. Confirmation of diagnosis at the blastocyst stage is a useful tool in PGD.

Aneuploidy↗
PubMed1998

Does the number of hypopnoeas influence therapy in patients with obstructive sleep apnoea?

The definition of hypopnoea varies widely between sleep laboratories. This study sought to evaluate the impact upon therapeutic decision of the most commonly used one, which defines hypopnoea as a reduction in airflow of 50% (or more) accompanied by a decreased blood oxygen saturation of 4% (or more) (Agency for Health Care Policy and Research). We studied 109 consecutive patients (99 male) with an apnoea-hypopnoea index (AHI) greater than 5. The same investigator evaluated each patient twice. First, the hypopnoea index (HI) was unavailable to him by study design, and judgment was based upon the number of apnoeas and the clinical situation of the patient. Thereafter, he evaluated all patients again, in random order, this time taking into account the AHI and the clinical condition of the patient. Therapeutic decision was compared at the end of the study. Mean age was 54 +/- 11 years (+/- SD) and body mass index 33 +/- 6 kg m-2. Most patients had normal spirometry and day-time arterial blood gases. Mean apnoea index (AI) was 35 +/- 24 h-1. Therapeutic decision based on the AI lead to conservative treatment (diet and sleep hygiene) in 32 cases and to active treatment in 77 patients [76 continuous positive airway pressure (CPAP) and one surgery]. The AHI was 40 +/- 24 h-1. The consideration of the number of hypopnoeas lead to a therapeutic change only in four patients (3.7%) (chi 2 = 0.36, P > 0.3). These four patients had an AI of 15, 7, 3, and 9 h-1 and an AHI of 22, 10, 46, and 17 h-1, respectively. Combined with their clinical data, this increase was considered a requirement for active treatment (CPAP). The most commonly used definition of hypopnoea has a small impact upon therapeutic decision in patients with obstructive sleep apnoea syndrome (OSAS). We suggest the need to develop new definitions of hypopnoea that incorporate other variables (neurophysiological, cardiovascular) of potential clinical relevance. Our results also show that the outcome of any new definition has to be assessed rigorously in terms of its clinical impact.

Adult↗
PubMed1998

Successful use of a laser for human embryo biopsy in preimplantation genetic diagnosis: report of two cases.

PURPOSE: The use of Tyrode's acid to drill the zona pellucida for embryo biopsy is the most widely used methodology in preimplantation genetic diagnosis. Instead of this, we propose the use of a 1.48-micron diode noncontact laser, which is quicker, simpler, and safer. METHODS: The laser beam was tangentially guided to the zona pellucida of the embryo. Depending on zona pellucida measurement, two to four consecutive shots of 8-22 msec were necessary to drill the zona pellucida of the 13 embryos biopsied for two patients (hemophilia carriers). RESULTS: Female embryos were replaced into the uterus of the patients (1.5 embryos/replacement). One single pregnancy was established (33.3% implantation rate). Coculture of untransferable embryos showed a blastocyst rate of 66.7% (4/6) for male embryos and 25% (1/4) for abnormal ones. CONCLUSIONS: These results demonstrate the safety and usefulness of laser methodology in preimplantation genetic diagnosis.

Adult↗
PubMed1998

Chromosome analysis of human preimplantation embryos.

Although karyotyping is the ideal method for diagnosing chromosome anomalies in the human embryo, the detection of chromosome anomalies in preimplantation human embryos by classical cytogenetics is extremely difficult. Nowadays, fluorescent in situ hybridization (FISH) in interphase nuclei is the method of choice. Both karyotype studies and FISH analysis of human preimplantation embryos obtained after in vitro fertilization (IVF) treatment revealed a high rate (25-51%) of chromosomally abnormal embryos. FISH analysis showed that chromosome mosaicism (22-24%) and chaotic embryos (7-26%) were the most frequent chromosome anomalies. Therefore, it seems that natural selection may be the reason for the low implantation rates of human preimplantation embryos in IVF programs. Although it is not possible to carry out such studies on embryos from natural conceptions, frequent occurrence of chromosome mosaicism and chaotically dividing embryos may apply to in vivo conception and explain the low fecundity rates in humans.

Blastocyst↗
PubMed1997

Laser blastocyst biopsy for preimplantation diagnosis in the human.

A new methodology for blastocyst biopsy that uses a 1.48 microm diode laser is described. Trophectoderm cells are biopsied after laster zona drilling and culture, fixed and processed for fluorescent in situ hybridisation (FISH) analysis. Preliminary results on the efficiency of the procedure and blastocyst recovery rate are promising. Blastocyst laser biopsy is a useful tool in preimplantation genetic diagnosis (PGD) as it allows a more reliable diagnosis and widens the diagnostic possibilities on account of the higher number of cells obtained in the biopsy.

Biopsy↗