Search PubMed⌕ Search

Biomedical subjects

E de Miguel

Publications and source records attributed to E de Miguel.

At least 37 records · Page 2Linked to original sources
PubMed1996

[An experimental model of hepatointestinal transplant in the pig with clinical applications].

A model of experimental hepatointestinal transplant in pigs, with clinical applications is presented. Ten animals received a graft composed by the liver and the full length of the small bowel. Two pigs died during the transplant and in eight the surgical procedure was well tolerated with a good revascularization of the grafts. The coagulation parameters were normal after the transplant and only minor biochemical disturbances were found. The main difficulties of the surgical technique are related with the poor tolerance of the pig to the portal and caval clamping, and the close relationships of the duodenum, pancreas and distal colon, produced by the 360 degrees anti-clockwise bowel rotation around the mesenteric vessels. Clamping the supraceliac aorta during the implant of the graft keeps the animal hemodynamically stable and makes unnecessary the use of the more complicated veno venous shunt.

Animals↗
PubMed1995

Localized right upper lobe edema.

One of the lesser known atypical forms of radiographic presentation of pulmonary edema is the isolated or predominant affection of the upper right lobe in patients with mitral valve insufficiency. As a possible cause of this distribution, it has been established that the regurgitation jet during the ventricular systole may be directed selectively toward the orifice of the right upper lobe vein, locally accentuating the forces responsible for edema formation. There are few cases with these characteristics in the literature reviewed. We present an additional three cases, concluding that localized pulmonary edema secondary to mitral insufficiency should be suspected in the presence of any type of airspace consolidation in the right upper lobe, with or without associated affection of the middle lobe, in patients with a history of mitral valve insufficiency, especially when there are radiologic signs of left heart failure.

Adult↗
PubMed1995

[Biochemical indicators of primary graft dysfunction in experimental orthotopic liver transplantation].

Aiming at investigating biochemical markers of Primary Graft Nonfunction (PNF) in Orthotopic Liver Transplantation (OLT) an experimental work is made on 21 Large-White pigs randomly distributed in three groups of seven, and two additional groups of seven donors each. In Group I the supra and infrahepatic cava, the portal vein and the hepatic artery were clamped. After 30 minutes the caval and portal clamps were released and 30 minutes later the arterial clamp was also removed. In Group II (viable), OLT was performed. The Collins solution was used as preservation fluid, keeping the cold ischemia time under 2 hours. In Group III (Non-Viable), an OLT was carried out 24 hours of cold ischemia with Collins solution. Blood samples are taken in 8 different moments along the procedure to determinate the values of AST, ALT, LDH, FA, Bilirubin, Uric Acid, Cholesterol, Triglycerides, Urea, Creatinine, Glucose, Total Protein, Calcium, Phosphorus, CPK and Aldolase. The last 5 samples were drawn after reperfusion. In the Group III we found, in the samples drawn after reperfusion of the graft, significant increases in 5 of these parameters, AST, ALT LDH, Aldolase and Uric Acid. We consider that these 5 parameters may be of value in the early diagnosis of PNF of the graft, being the AST and ALT the most reliable, with the higher specificity for the same sensitivity.

Alanine Transaminase↗
PubMed1995

L-aspartate aminotransferase and L-asparaginase in rat lymph node: a histoenzymological and immunohistochemical study.

L-asparaginase and L-aspartate aminotransferase are both involved in the synthesis of L-aspartic acid. It has been observed that L-asparaginase is involved in the immunosuppressor morphine-dependent syndrome in lymphoid cells whereas L-aspartic acid blocks the development of this syndrome. The aim of the present study was to clarify the localization of L-AATase activity and L-asparaginase in rat lymph nodes using histoenzymological and immunohistochemical methods, respectively. No positive reaction was demonstrated for L-AATase while L-asparaginase shown to be present in lymphocytes and lymphoblastic cells. These observations lead us to suggest that L-asparaginase is the enzyme mainly responsible for the synthesis of the L-aspartic acid necessary for satisfying the living requirements of lymphoid cells. Therapeutically administered L-asparaginase could exert its action intracellularly after crossing the cell membrane.

Animals↗
PubMed1994

Neuropeptides and interleukin-6 in human joint inflammation relationship between intraarticular substance P and interleukin-6 concentrations.

Plasma and synovial fluid concentrations of interleukin-6 (IL-6), using an enzyme-linked immunosorbent assay, as well as immunoreactive levels of calcitonin gene-related peptide (CGRP), substance P and vasoactive intestinal peptide (VIP) were measured in 18 patients with rheumatoid arthritis and 20 with osteoarthritis of the knee. The concentrations of IL-6 were elevated in both plasma and synovial fluids from patients with rheumatoid arthritis whereas higher levels of substance P-, CGRP- and VIP-like immunoreactivities were found in the synovial fluid, but not in plasma, from patients with rheumatoid arthritis when compared with those in osteoarthritis. Furthermore, IL-6 and substance P levels in synovial fluid were significantly correlated both in rheumatoid arthritis and osteoarthritis patients. Our data seem to support the idea of an important role shared by neuropeptides and IL-6 in the pathogenesis of human inflammatory joint disease.

Arthritis, Rheumatoid↗
PubMed1994

Trophic effects of neurotensin in massive bowel resection in the rat.

The trophic effect of the administration of exogenous neurotensin on the intestinal mucosa was studied in rats following an 80% bowel resection. Villus length and mucosal DNA content were assessed in the jejunal and ileal mucosa of the remnant intestine 14 days after resection. The data obtained in an 80% resected control group (80% group) and an experimental group receiving an infusion of neurotensin (300 micrograms/kg/day) for 14 days subcutaneously (80% + NT group) were compared. The results indicate that the administration of exogenous neurotensin (80% + NT) increases villus length (jejunum: 920 +/- 77 vs 861 +/- 25 microns and ileum length: 975 +/- 23 vs 875 +/- 99 microns) to an extent greater than that observed in the 80% resected group not receiving exogenous neurotensin. The levels of mucosal DNA per milligram of protein increased significantly in both groups but was paradoxically less in the 80% + NT group than in the 80% resection group (jejunum: 8.12 +/- 0.56 vs 10.18 +/- 0.80; ileum: 8.63 +/- 0.43 vs 10.05 +/- 0.46). These data suggest that the administration of exogenous neurotensin to the rat potentiates the growth of intestinal villi and accelerates the intestinal trophic response seen following massive bowel resection. The increase in circulating enteroglucagon levels noted after neurotensin administration (80% + NT: 547 +/- 48 pg/ml vs 80%: 341 +/- 41 pg/ml) suggests that some of the trophic effects of neurotensin may be mediated, at least in part, by enteroglucagon. These data also suggest a potential role for the use of neurotensin in the initial treatment of individuals with short bowel syndrome.

Adaptation, Physiological↗
PubMed1994

Plasma enteroglucagon levels in different models of intestinal resection in the rat.

To assess the influence of the different intestinal segments on the plasma enteroglucagon level, three models of intestinal resection in the rat were studied (jejunal, ileal, 90%). The basal values for this peptide and those obtained after an infusion of intraduodenal glucose were compared. The results obtained in basal/post-glucose infusion were: 50% proximal (jejunum): 220/728 pg/ml; 50% distal (ileum): 10/233 pg/ml; and the middle 90%: 108/297 pg/ml. The glucose infusion produced a maximal response, permitting a better evaluation of the differences among the three resection models. The highest levels corresponded to the group in which the entire ileum was conserved.

Adaptation, Physiological↗
PubMed1994

Purine metabolism in women with primary gout.

PURPOSE: Uncontrolled studies have shown that women with gout have higher serum urate concentrations and similar or lower urinary uric acid excretion rates than do men with gout. These observations suggest a more defective tubular transport of uric acid in women than in men with gout. In this prospective study we assessed purine metabolism in women with primary gout under controlled conditions. We also examined whether there are sex-related differences in plasma and urinary purine concentrations among patients with primary gout. SUBJECTS AND METHODS: Ten women with crystal-proved primary gout and normal serum creatinine levels (below 116 mmol/L) were studied while they were on a purine-restricted diet and taking no medications known to influence uric acid metabolism. For comparison, 20 men with primary gout and 10 women without gout, matched for age, race, and body mass index, were studied under the same conditions. In each subject, plasma and 24-hour urinary uric acid, hypoxanthine, and xanthine concentrations were measured. The mean of three consecutive determinations for plasma purines and five for urinary purines was used. Standard formulas were used to calculate the renal clearances and the fractional excretion of purines. RESULTS: Mean plasma urate, hypoxanthine, and xanthine levels were significantly higher in women patients with primary gout compared with normal women (P < 0.05). Mean 24-hour urinary uric acid excretion was similar in both groups. Daily urinary hypoxanthine and xanthine excretion rates were significantly lower in gouty women patients than in control women (P < 0.05). The renal clearances and the fractional excretion of uric acid, hypoxanthine, and xanthine were markedly lower in women with primary gout than in control women (P < 0.05). Plasma and urinary purine concentrations were similarly increased and diminished, respectively, in women and men patients with primary gout. Plasma urate, hypoxanthine, and xanthine levels were inversely and significantly associated with the fractional excretion of uric acid (r = -0.520; P = 0.003), hypoxanthine (r = -0.555; P = 0.002), and xanthine (r = -0.384; P = 0.040), respectively. CONCLUSION: Women with primary gout have markedly diminished uric acid, hypoxanthine, and xanthine excretion rates. The disturbance of purine metabolism appears to be of a similar magnitude to that observed in gouty men. The absence of significant sex-related differences in plasma and urinary purine concentrations suggests a similar tubular dysfunction for purine excretion in women and men with primary gout.

Aged↗
PubMed1993

[Necrotizing vasculitis in the bladder].

The necrotizing lesion that affects the small and medium-sized arteries, commonly known as polyarteritis nodosa (PAN), usually have a systemic and variable involvement. Urothelial involvement at the level of the two ureters has been rarely described. We report a case of necrotizing vasculitis localized to the bladder that had manifested clinically as gross hematuria.

Aged↗
PubMed1992

Potent slow-binding inhibition of cathepsin B by its propeptide.

A peptide (PCB1) corresponding to the proregion of the rat cysteine protease cathepsin B was synthesized and its ability to inhibit cathepsin B activity investigated. PCB1 was found to be a potent inhibitor of mature cathepsin B at pH 6.0, yielding a Ki = 0.4 nM. This inhibition obeyed slow-binding kinetics and occurred as a one-step process with a k1 = 5.2 x 10(5) M-1 s-1 and a k2 = 2.2 x 10(-4) s-1. On dropping from pH 6.0 to 4.7, Ki increased markedly, and whereas k1 remained essentially unchanged, k2 increased to 4.5 x 10(-3) s-1. Thus, the increase in Ki at lower pH is due primarily to an increased dissociation rate for the cathepsin B/PCB1 complex. At pH 4.0, the inhibition was 160-fold weaker (Ki = 64 nM) than at pH 6.0, and the propeptide appeared to behave as a classical competitive inhibitor rather than a slow-binding inhibitor. Incubation of cathepsin B with a 10-fold excess of PCB1 overnight at pH 4.0 resulted in extensive cleavage of the propetide whereas no cleavage occurred at pH 6.0, consistent with the formation of a tight complex between cathepsin B and PCB1 at the higher pH. The synthetic propeptide of cathepsin B was found to be a much weaker inhibitor of papain, a structurally similar cysteine protease, and no pH dependence was observed. Inhibition constants of 2.8 and 5.6 microM were obtained for papain inhibition by PCB1 at pH 4.0 and 6.0, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1992

The origin of trochlear motoneurons in the larval sea lamprey, Petromyzon marinus L. An HRP study.

The origin of trochlear motoneurons in larval lampreys was studied by injection of HRP into the orbit. Immature motoneurons had ventricular attachments, the position of which with respect to the ventricular sulci was used to study their regions of origin. Motoneurons originate from the region between the sulcus intermedius dorsalis and the sulcus intermedius ventralis, which in other parts of the brain were identified as the visceromotor and viscerosensory columns. Both ipsilateral and contralateral immature motoneurons were found. The significance of these findings is discussed in relation to the origins of the trochlear nerve and its nucleus in vertebrates.

Aging↗
PubMed1992

McArdle's disease and gout.

We report the first case of McArdle's disease (muscle phosphorylase deficiency) and tophaceous gout. To examine the contribution of adenine nucleotide degradation to the disturbance of uric acid metabolism, we labeled the adenine nucleotide pool with [8-14C]adenine, and measured plasma and urine purines following vigorous exercise tests. Plasma and urinary hypoxanthine and xanthine concentrations and the specific radioactivity of urinary purines increased markedly, but plasma urate levels and uric acid excretion were not substantially modified. We suggest that, in this patient, the association of McArcle's disease with gout is coincidental.

Adenine Nucleotides↗
PubMed1992

Inadequate production of progesterone in women with systemic lupus erythematosus.

We have performed a longitudinal study of the hypothalamic-pituitary-ovary axis and adrenal function during the menstrual cycle in 26 women with inactive or quiescent systemic lupus erythematosus (SLE) and in 21 healthy women as controls. In all women studied, the menstrual cycle was proved to be ovulatory by ultrasound imaging and detection of an appropriately elevated value of peak serum progesterone. Blood samples were obtained for hormonal assay on several days of the menstrual cycle studied. Patients with SLE had lower peak and day-7 postovulation serum progesterone concentrations which were both significantly lower than those found in controls, whereas no major differences were observed for any of the other hormones analysed. Although the significance of the inadequate production of progesterone we have observed in SLE women with inactive disease is not clear, our data seem to indicate that a relative deficiency of progesterone might be considered among the potential predisposing factors for development of SLE in women.

Adult↗
PubMed1991

Female gout. Clinical spectrum and uric acid metabolism.

We reviewed the clinical features and uric acid metabolism in 37 female patients with gout. In 32 female patients (86%), gout was diagnosed after menopause. Among the five premenopausal patients, four had renal insufficiency and one had superactivity of phosphoribosylpyrophosphate synthetase. More than 50% of the female patients had osteoarthritis, hypertension, or renal insufficiency or were treated with diuretics. Comparison with 220 male patients with gout showed that female patients developed gout significantly later, more frequently had associated diseases, and more often were receiving diuretics, whereas significantly more male than female patients had alcoholism. The articular features of gout were similar in both groups. However, the prevalence of tophi was higher and its localization different in female than in male patients. Female patients with gout had a higher mean serum urate concentration and a lower mean urinary uric acid excretion than did male patients with gout. These differences were significant and independent of the effects of age, renal insufficiency, alcoholism, or previous diuretic intake. Renal underexcretion of uric acid appears to be more severe in female than in male patients with gout.

Adult↗
PubMed1991

Identification of glucagon binding sites on smooth muscle tissue of dog intestine. Quantification by means of ultrastructural autoradiography.

125I-glucagon binding sites have been detected and quantified on the intestinal smooth muscle cells of the dog by means of ultrastructural autoradiographic methods. These binding sites are located mainly in the plasmalema. The present findings established a morphological correlation with the physiological data concerning the spasmolytic function of the glucagon on the intestinal wall.

Animals↗