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Biomedical subjects

E Morales

Publications and source records attributed to E Morales.

At least 19 recordsLinked to original sources
PubMed2003

Results of kidney transplantation in recipients over 70 years of age: experience at a single center.

We performed 41 kidney transplants in patients >70 years (35 single and 6 dual), with a mean recipient age of 72+/-2 years, from January 1990 to December 2001. Mean age of the donors was 69+/-12 years. Immunosuppression used triple therapy with steroids, mycophenolate mofetil, and cyclosporine or tacrolimus. Cold ischemia time was 23+/-3 hours. The incidence of primary nonfunction was 4.8%, and delayed graft function 58.5%. Acute rejection incidence was 12%. The actuarial patient survival rates at 12, 24, and 36 months were 82.5%, 82.5%, and 75%, respectively. Actuarial survival rates of the grafts censuring for death of the recipient with a functioning graft were 89.5%, 86%, and 68%, respectively. Nine of the 18 graft losses were due to recipient death. Overall, renal transplant recipients >70 years showed good results. The principal cause of graft loss was recipient death.

Aged↗
PubMed2003

Helical computed tomography angiography is the most efficient test to assess vascular calcifications in the iliac arterial sector in renal transplant candidates.

UNLABELLED: The increased scope of renal transplant indications has lead to a larger number of recipients with vascular problems due to arterial calcifications in the iliac region. Compared to magnetic resonance and conventional arteriography, helical computed tomography angiography (HCTA) accurately depicts arterial diseases, including the location and extent of arterial calcification. The objective of this study was to assess the value of HCTA with maximum-intensity-projection (MIP) reconstruction to evaluate iliac arterial calcifications and stenosis among candidates for renal transplantation. MATERIAL AND METHODS: From December 1997 to March 2002, 114 HCTA scans with MIP reconstruction were performed in candidates for renal transplantation. Included patients fulfilled some of the following conditions: (a) older than 55 years, (b) diabetic, (c) second transplants, and (d) obvious vascular calcifications on plain abdominal x-ray. RESULTS: Among the 114 patients, 33 (29%) were excluded for transplantation due to universal calcification of the iliac arterial sector, and 81 (71%) were included on the waiting list due to the presence of calcium-free areas for the vascular anastomosis. Transplantation, which was attempted in 28 of the 81 patients, was successful in 25 using the area programmed after HCTA analysis. The transplants failed in three cases because no calcium-free area could be found upon surgical examination. CONCLUSION: HCTA with MIP reconstruction makes it possible to draw an exact map of the arterial calcifications of the iliac arterial sector, allowing better recipient selection and accurate planning for the vascular anastomosis and placement of the renal graft.

Angiography↗
PubMed2003

Effect of ageing on the proliferation and apoptosis of testicular germ cells in the Syrian hamster Mesocricetus auratus.

The cellular mechanisms implicated in the atrophy of seminiferous epithelium in ageing are currently under debate, although recent reports suggest that apoptosis may be the primary mechanism implicated in aged germ cell loss. Other investigators have suggested that changes in spermatogonial proliferation are also involved. In the present work, the changes in proliferation and apoptosis in the seminiferous epithelium of aged (24 months) Syrian hamsters were examined in concert and compared with those in young (6 months) animals. Proliferation of germ cells was studied by bromodeoxyuridine labelling and apoptosis was assessed by transmission electron microscopy and in situ TUNEL labelling. Aged animals showed a significant decrease in the numbers of total and proliferating spermatogonia plus preleptotene spermatocytes per unit volume and per testis and in the proliferative index (24.8 +/- 1.6%) compared with young animals (30.8 +/- 1.2%) (P < 0.05). The number of apoptotic spermatogonia plus spermatocytes per unit volume and the apoptotic index were significantly higher in aged animals (1.51 +/- 0.23% v. 0.77 +/- 0.04%; P < 0.05). Apoptosis was confirmed by morphological characteristics: condensation of the chromatin and nuclear fragmentation. In aged hamsters, tubular degeneration could be classified into several categories, showing an increase of apoptotic cells in tubular cross-sections characterized by maturation arrest in comparison with all other types. Spermatogonial proliferation was also diminished as seen in tubular cross-sections showing hypospermatogenesis, sloughing off of germ cells and maturation arrest. The results obtained in the present study suggest that the decrease in the proliferation of spermatogonia and the increase in apoptosis constitute two consecutive mechanisms correlated with the ageing of the seminiferous epithelium.

Aging↗
PubMed2003

[Immunoallergic interstitial nephritis vs. cholesterol atheroembolism. Differentiating characteristics].

The commonest clinical presentation of both immunoalergic interstitial nephritis (IIN) and atheroembolic renal disease (ATD) is an acute renal failure accompanied by skin lesions and eosinophilia. As a consequence, differential diagnosis between both entities is often very difficult. We have performed a comparative retrospective study of those patients diagnosed as having IIN or ATD in our Hospital in the period 1980-2000. A total of 42 patients have been diagnosed of IIN and 16 of ATD. Demographic data, as well as clinical and laboratory parameters and outcomes of every studied patient were analysed. We found a significantly higher prevalence of male sex (100% vs 57%, p < 0.01), previous history of hypertension (100% vs 55%, p < 0.01), chronic renal insufficiency (56% vs 17%, p < 0.01), ischemic heart disease (56% vs 14%, p < 0.001), peripheral ischemic disease, endovascular procedures (87% vs 7%, p < 0.001) and anticoagulant treatments (25% vs 5%, p < 0.001) among patients with ATD as compared with IIN, respectively. On the contrary, previous infections (45% vs 12%, p < 0.01) and exposure to new drugs (100% vs 40%, p < 0.001) were significantly more frequent among IIN patients in compare with ATD. ATD patients showed skin lesions consisting of livedo reticularis and digital infarcts (63% vs 31%, p < 0.05) accompanied by blood pressure increase (100% vs 24%, p < 0.001), whereas IIN patients showed fever (41% vs 19%, p < 0.05) and cutaneous rash as significant clinical manifestations, respectively. The number of ATD patients with proteinuria > 1 g/24 h was significantly higher, but no differences between both groups in the prevalence of urinary sediment abnormalities were observed. The prevalence of absolute eosinophilia was high in both groups (88% among ATD patients, 64% among IIN patients; pNS). Prognosis of both entities was clearly different: Almost all patients with ATD died (69%) or evolved to end-stage renal failure, whereas most patients with IIN showed a recovery of renal function after withdrawal of responsible drugs and steroid treatment. In summary, the analysis of clinical and laboratory data allows an initial differential diagnosis in patients suspected as having IIN or ATD.

Acute Kidney Injury↗
PubMed2002

Determination of polychlorinated biphenyls in biota samples using simultaneous pressurized liquid extraction and purification.

In order to reduce time and cost of analysis, a new pressurised liquid extraction method that automatically and rapidly achieves quantitative and selective (i.e., lipid-free) extraction of polychlorinated biphenyls (PCBs) in biota tissues was optimized. It consists of on-line clean-up by inclusion of sorbents in the extraction cell. The freeze-dried sample is dispersed with Florisil and loaded in the extraction cell containing an extra amount of Florisil. The extraction is performed under mild conditions using 55 ml of a dichloromethane-pentane (15:85) mixture, a temperature of 40 degrees C, a static extraction time of 10 min and two extraction cycles. The Florisil retains coextracted lipids from the matrix, and the extract, after pre-concentration, is clean enough for direct injection into GC-MS and GC-electron-capture detection (ECD). Quantitative recoveries (from 90 to 106%) are obtained for both native and spiked PCB congeners in samples with a high lipidic content (up to 42% dry mass, in spoonbill eggs). The reproducibility of replicate extractions was better than 11% relative standard deviation. Method detection limits were in the ranges of 0.001-0.004 and 0.002-0.07 ng g(-1) dry mass for GC-ECD and GC-MS-MS, respectively. The method was validated using the standard reference material SRM 2974 (a mussel tissue) from the US National Institute of Standards and Technology, compared to Soxhlet and matrix solid-phase dispersion extraction methods, and used to evaluate the contamination by PCBs in bivalves from South of Spain.

Animals↗
PubMed2001

Sample treatment in chromatography-based speciation of organometallic pollutants.

Speciation analysis is nowadays performed routinely in many laboratories to control the quality of the environment, food and health. Chemical speciation analyses generally include the study of different oxidation state of elements or individual organometallic compounds. The determination of the different chemical forms of elements is still an analytical challenge, since they are often unstable and concentrations in different matrices of interest are in the microg l(-1) or even in the ng l(-1) range (e.g., estuarine waters) or ng g(-1) in sediments and biological tissues. For this reason, sensitive and selective analytical atomic techniques are being used as available detectors for speciation, generally coupled with chromatography for the time-resolved introduction of analytes into the atomic spectrometer. The complexity of these instrumental couplings has a straightforward consequence on the duration of the analysis, but sample preparation to separate and transfer the chemical species present in the sample into a solution to be accepted readily by a chromatographic column is the more critical step of total analysis, and demands considerable operator skills and time cost. Traditionally, liquid-liquid extraction has been employed for sample treatment with serious disadvantages, such as consumption, disposal and long-term exposure to organic solvent. In addition, they are usually cumbersome and time-consuming. Therefore, the introduction of new reagents such as sodium tetraethylborate for the simultaneous derivatization of several elements has been proposed. Other possibilities are based in the implementation of techniques for efficient and accelerated isolation of species from the sample matrix. This is the case for microwave-assisted extraction, solid-phase extraction and microextraction, supercritical fluid extraction or pressurized liquid extraction, which offer new possibilities in species treatment, and the advantages of a drastic reduction of the extraction time and the embodiment into on-line flow analysis systems. This new generation of treatment techniques constitutes a good choice as fast extraction methods for feasible species-selective analysis of organometallic compounds under the picogram level, that can be used for national regulatory agencies, governmental and industrial quality control laboratories, and consequently, for manufacturers of analytical instrumentation.

Chromatography↗
PubMed2001

The contribution of dendritic Kv3 K+ channels to burst threshold in a sensory neuron.

Voltage-gated ion channels localized to dendritic membranes can shape signal processing in central neurons. This study describes the distribution and functional role of a high voltage-activating K(+) channel in the electrosensory lobe (ELL) of an apteronotid weakly electric fish. We identify a homolog of the Kv3.3 K(+) channel, AptKv3.3, that exhibits a high density of mRNA expression and immunolabel that is distributed over the entire soma-dendritic axis of ELL pyramidal cells. The kinetics and pharmacology of native K(+) channels recorded in pyramidal cell somata and apical dendrites match those of AptKv3.3 channels expressed in a heterologous expression system. The functional role of AptKv3.3 channels was assessed using focal drug ejections in somatic and dendritic regions of an in vitro slice preparation. Local blockade of AptKv3.3 channels slows the repolarization of spikes in pyramidal cell somata as well as spikes backpropagating into apical dendrites. The resulting increase in dendritic spike duration lowers the threshold for a gamma-frequency burst discharge that is driven by inward current associated with backpropagating dendritic spikes. Thus, dendritic AptKv3.3 K(+) channels influence the threshold for a form of burst discharge that has an established role in feature extraction of sensory input.

Action Potentials↗
PubMed2001

Neosporosis in Mexican dairy herds: lesions and immunohistochemical detection of Neospora caninum in fetuses.

Of 211 aborted bovine fetuses collected from Mexican dairy herds between January 1996 and March 1999, 73 showed microscopical lesions consistent with neosporosis. Of these 73 fetuses, 58 (79%) showed lymphocytic myocarditis, 39 (53%) showed microgliosis and multifocal necrosis in the brain, 39 (53%) showed lymphocytic hepatitis, and 19 (26%) showed lymphocytic myositis. Immunohistochemical examination of brain, myocardium and liver from 53 of the same 73 fetuses demonstrated Neospora caninum antigens in 41 (77%), of which 19 (46%) gave positive results in one of the three sites, 15 (37%) in two, and seven (17%) in three. The results indicated the presence of neosporosis in a number of the main dairy farming regions of Mexico.

Abortion, Veterinary↗
PubMed2001

Clinical features and long-term outcome of obesity-associated focal segmental glomerulosclerosis.

BACKGROUND: Several cases of obesity-associated focal segmental glomerulosclerosis (OB-FSG) have been reported but little is known about the clinico-pathological features of this entity and its long-term outcomes. METHODS: We studied 15 obese patients (BMI 35+/-5.2 kg/m(2)) with biopsy-proven FSG. They were compared with a control group of 15 non-obese patients with idiopathic FSG (I-FSG). RESULTS: Mean proteinuria at the time of renal biopsy was 3.1+/-2 g/24 h in OB-FSG; it reached the nephrotic range (> or =3.5 g/24 h) during follow-up in 12 patients (80%), but none of them had oedema, hypoproteinaemia, or hypoalbuminaemia. Proteinuria was more marked amongst I-FSG (6.5+/-4.2 g/24 h) and most of them developed oedema and biochemical nephrotic syndrome. Glomerulomegaly was observed in all renal biopsies from OB-FSG patients (mean glomerular diameter 256+/-24 microm in OB-FSG vs 199+/-26 microm in I-FSG, P<0.001). Twelve OB-FSG patients (80%) were treated with ACE inhibitors (ACEI) and proteinuria significantly decreased within the first 6 months of treatment but showed a later increase. None of the obese patients achieved a sustained weight loss. Seven (46%) patients with OB-FSG experienced a progressive renal insufficiency and five of them started intermittent dialysis. Kaplan-Meier estimated probabilities of renal survival after 5 and 10 years were 77 and 51%, respectively, in OB-FSG patients, and 52 and 30% in I-FSG (P<0.05). The risk of developing progressive renal failure among OB-FSG patients was statistically correlated with serum creatinine and creatinine clearance at presentation. CONCLUSIONS: OB-FSG indicates a poor prognosis with almost one-half of patients developing advanced renal failure. Knowledge of the clinico-pathological features of this entity (obesity, FSG lesions with glomerulomegaly, absence of nephrotic syndrome despite nephrotic-range proteinuria) should be helpful in establishing an accurate and early diagnosis.

Adult↗
PubMed2001

Seroprevalence study of bovine neosporosis in Mexico.

An indirect enzyme-linked immunosorbent assay was used to obtain epidemiologic information on bovine neosporosis in dairy herds of the Mexican central plateau. Sera were collected from 1,003 cows from 50 dairy herds. Forty-three herds (group A) had been experiencing a high abortion rate. The abortion rates for the remaining 7 herds (group B) were within normal limits for Mexico. Five-hundred sixty-one (56%) of the 1,003 sera were positive. The seroprevalence of Neospora caninum antibodies was 72% (95% CI = 68-75%) in group A and 36% (95% CI = 31-40%) in group B. These results clearly show that infection with N. caninum is widespread in Mexican dairy herds, as indicated by seropositive cows in group A and group B herds at the time of the sample collection.

Animal Husbandry↗
PubMed2000

Column-switching system for selenium speciation by coupling reversed-phase and ion-exchange high-performance liquid chromatography with microwave-assisted digestion-hydride generation-atomic fluorescence spectrometry.

Speciation of selenocysteine (SeCys), selenomethionine (SeMet), selenoethionine (SeET), selenite (Se(IV)) and selenate (Se(VI)) has been accomplished using high-performance liquid chromatography, with the aid of an anion exchange column and a reversed-phase column, both connected through a six-port switching valve. On-line microwave-assisted digestion and hydride generation steps were performed prior to the atomic fluorescence detection. The elution of the seleno amino acids was accomplished in the reversed-phased column using water as mobile phase. Selenite and selenate were separated in the anion exchange column, using gradient elution with an acetate buffer. The separation of the five selenium compounds took place in 15 min. The detection limits obtained ranged between 0.6 and 0.9 microg l(-1). Values of r>0.998 were obtained for linear fit graphs. A commercial available urine sample was analyzed, in which SeCys and Se(IV) were quantified.

Chromatography, High Pressure Liquid↗
PubMed2000

Double versus single renal allografts from aged donors.

BACKGROUND: The age limit of the cadaver kidney donors is increasing in response to the growing demand for renal transplantation. Simultaneous double kidney transplantation (SDKT) with kidneys obtained from elderly adults has been proposed to increase the transplantation number and improve its results. However, if SDKT is performed when there are no clear indications, a negative effect could be produced on the total number of transplanted patients as both kidneys would be used for only one recipient. MATERIAL AND METHODS: In December 1996 we designed a transplantation protocol to be able to extend the selection of cadaver kidney donors with normal serum creatinine levels without establishing any age limit. A pregraft renal biopsy was always performed to analyze the glomerulosclerosis (GE) percentage whenever the donors were 60 years of age or older. A SDKT was performed in a single recipient when the donor age was 75 years or older or when the donors between 60 and 74 years old had a GE rate of more than 15%. On the contrary, a single kidney transplantation was performed in two different recipients for kidneys from donors between 60 and 74 years of age with a GE rate of less than 15%. Kidneys having GE rates of more than 50% were discarded for transplantation. Donor kidneys from subjects younger than 60 years of age were always used for a single kidney transplantation. RESULTS: Based on the above mentioned protocol, from December 1996 to May 1998, 181 patients received a kidney transplantation in our hospital. These patients were divided into three groups: group I which included the SDKT recipients (n=21), group II or single kidney recipients from 60- to 74-year-old donors (n=40), and group III or recipients from <60-year-old donors (n=120). The mean follow-up time was 15+/-5 months (range 6-24). Mean donor age was 75+/-7 years in group I, this was significantly higher than in group II (67+/-4, P<0.001) and group III (37+/-15, P<0.001). The primary nonfunction rate was low in the three groups, there being no statistically significant differences (5, 5, and 4%, respectively). A significantly greater percentage of patients from group I (76%) presented immediate renal graft function as compared with group II (43%, P<0.01) and III (50%, P<0.05). The acute rejections rate was very low in all three groups (9.5, 7.5, and 22%, respectively) with significant differences between groups II and III (P<0.05). No significant differences between the different groups were observed for one year actuarial patient survival (100, 95, and 98%, respectively) or graft survival rates (95, 90, and 93%, respectively). The 6-month serum creatinine levels were excellent in the three groups, although there were significant differences between groups I and II (1.6+/-0.3 vs. 1.9+/-0.6 mg/dl, P<0.05), II and III (1.9+/-0.6 vs. 1.4+/-0.4 mg/dl, P<0.001), and I and III (P<0.05). CONCLUSIONS: Simultaneous double kidney transplantations make it possible to use kidneys from extremely elderly donors (>75 years) or those whose GE>15%. In addition, kidneys from donor 60-74 years old in which the GE<15% can be used for single kidney transplantations in two different recipients with excellent results.

Adult↗