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M C Díaz

Publications and source records attributed to M C Díaz.

At least 19 recordsLinked to original sources
PubMed1999

A high index of suspicion: the key to an early diagnosis of Wilson's disease in childhood.

BACKGROUND: To study the clinical features of Wilson's disease in childhood. METHODS: Retrospective review of the clinical, laboratory, and histologic features and prognosis of Wilson's disease in 26 Spanish children. RESULTS: The first medical visit, at age 9.8+/-3.4 years (range, 4-16 years), was prompted by liver dysfunction detected accidentally (61%), symptoms of liver disease (27%), family screening (8%), and extrapyramidal symptoms and personality changes (4%). There were laboratory data of hepatic failure in 27%. All copper metabolism test results (total serum copper, 24-hour urine excretion, serum ceruloplasmin) were abnormal in 62%, two in 27%, and one in 11%. All patients in whom extrahepatic involvement was found at diagnosis had severe liver disease. Histologic findings were portal fibrosis with steatosis (29%), cirrhosis (21%), portal fibrosis (17%), chronic active hepatitis (17%), and minimal changes or normality (17%). Penicillamine was administered to all but one patient. Four children underwent liver transplantation, three of them having received penicillamine for 12, 45, and 70 days. Three other patients recovered from liver failure after 1 year of treatment with penicillamine. After a follow-up of 4.5+/-3.3 years, all the children survived. Penicillamine caused severe toxicity in one patient. CONCLUSIONS: Wilson's disease in childhood is generally detected by maintaining a high suspicion of liver disease in patients who have no or nonspecific hepatic symptoms. Kayser-Fleischer ring is rare in childhood. Drug therapy is effective and well tolerated, even in some cases of hepatic insufficiency.

Adolescent↗
PubMed1998

Tacrolimus for steroid-resistant liver rejection in children.

Eighteen pediatric liver transplant recipients were converted from cyclosporine-based immunosuppression to tacrolimus for refractory rejection episodes affecting 21 grafts. Before conversion, steroid boluses were applied to all episodes followed by OKT3 monoclonal antibodies in 3 of them. Baseline biopsy showed cellular rejection in 18 patients and ductopenia in 3 cases. Thirteen episodes initiated within the first 2 postoperative weeks, and 8 occurred beyond the 21st day. A previous steroid-responsive episode of rejection was noted in 4 patients. Tacrolimus was administered by the oral route to obtain trough blood levels in the range 6-15 ng/ml. Reversal of rejection was obtained in 15 patients (71.4%). Complete normalization of liver function tests was achieved in 10 out of 12 patients who were followed for more than 6 months. A refractory evolution affected 6 patients (28.5%). Significant factors predictive for tacrolimus-resistant rejection were identified as ductopenia on baseline biopsy, previous episodes of acute rejection, late onset rejection (beyond 21st posttransplant (day), and a longer time of evolution of rejection prior to conversion.

Adolescent↗
PubMed1997

Vasoactive intestinal peptide (VIP) mediates the effect of estrogens on the dopaminergic tone in the hypothalamic-pituitary axis of ovariectomized (OVX) rats.

The role of vasoactive intestinal peptide (VIP) in the regulation of dopamine (DA) concentration in mediobasal hypothalamus (MBH), posterior and anterior pituitary of ovariectomized (OVX) estrogenized rats was studied using passive immunization against VIP with a specific antiserum (a-VIP). Chronic estradiol administration decreased DA concentration in MBH, and in posterior and anterior pituitary, compared to OVX control rats. DA tissue concentration increased following a-VIP administration to control and estrogenized OVX rats. In vitro study of VIP and a-VIP on DA release from MBH in chronically estrogenized OVX rats showed that estrogens decreased DA evoked-release from MBH;a-VIP increased DA evoked-release from MBH of control OVX and estrogenized rats. VIP decreased DA evoked-release from MBH of OVX rats, but had no effect on estrogenized rats. VIP decreased DA tissue concentration in MBH of OVX control but not of estrogenized rats. It is suggested that VIP decreases DA synthesis and release from hypothalamic neurons in female rats, and that VIP partially mediates the inhibitory effect of long-term estrogen administration on DA release from MBH.

Animals↗
PubMed1996

Neurokinin A affects the tubero-hypophyseal gabaergic system.

We have studied the in vitro effects of neurokinin A (NKA) on anterior pituitary GABA concentration and GABA release from the mediobasal hypothalamus and the neurointermediate lobe of male and ovariectomized female (OVX) rats. NKA significantly decreased the anterior pituitary GABA concentration, while the presence of a specific anti-NKA serum in the incubation medium increased the GABA concentration in this gland. By contrast, NKA did not modify basal or K(+)-evoked GABA release from the mediobasal hypothalamus of male or OVX rats. However, NKA decreased basal and K(+)-evoked GABA release from the neurointermediate lobe. Since GABA inhibits both prolactin (PRL) secretion from the anterior pituitary and the release of several putative PRL-releasing factors from the neurointermediate lobe, the decrease in anterior pituitary GABA concentration and the reduction in tubero-hypophyseal GABAergic activity induced by NKA may contribute to the stimulatory effect of this peptide on PRL secretion.

Animals↗
PubMed1996

Growth and height in children after liver transplantation.

To assess the linear growth after liver transplantation, height curves were constructed for 45 children who underwent liver transplantation at the Children's Hospital "La Paz", Madrid, and were followed for more than 2 years. The prednisolone dose was progressively tapered and switched to alternate-day administration at 12 months. Growth was severely impaired during daily steroid therapy but the mean growth rate normalized in the second year and a significant improvement was observed in successive years. Observations over a long period revealed fluctuating growth rates under stable or decreasing doses of prednisolone on alternate-day administration. Beyond the first year, some annual periods of abnormal growth rate occurred in 57% of the children. Marginally better posttransplantation growth was observed in children transplanted for intrahepatic cholestatic diseases. The prednisolone dose did not correlate with growth rate. In the long term, short stature was highly prevalent due to an accumulation of factors: previous disease, daily prednisolone period, inconstant growth rate under alternate-day steroid therapy, and pubertal delay.

Adolescent↗
PubMed1995

[Reduced-size liver transplants from cadaver and living donors: an alternative to waiting lists].

The ever expanding of indications of liver transplantation in children make pediatric donor pool unable to fulfill the needs. The reduced and partial transplants from cadaveric and living related donors reveal an effort to increase the number of pediatric grafts aid to reduce the mortality in the waiting list. Among 126 pediatric transplants performed in a 8-year period, 18 (15%) were reduced (n = 3) and partial livers (with preservation of the recipient vena cava) (n = 15). In 1993, 41% (n = 12) of the 29 liver transplantations performed were partial segments. In two of them the graft was harvested from a living-related donor. Eight transplants were made on an emergency basis and ten were elective. Eight patients were retransplanted. Considering the transplants performed in the Wisconsin era, after completing the "learning curve" the actuarial survival at five years reaches 65% approaching 70% for patients younger than 1 year and/or weighing less than 13 kg. The arterial complications in this group are limited to a single case of thrombosis. Despite our limited experience we conclude that reduced and partial transplants are useful to reduce the mortality in the waiting list with a survival similar to that of the whole grafts and with less vascular complications. The living-related transplant represents another step ahead that allows a further reduction of the shortage of organ available for the small children.

Age Factors↗
PubMed1994

GABA transport and subcellular distribution in the rat anterior pituitary gland.

In this investigation we have studied the uptake of gamma aminobutyric acid (GABA) into anterior pituitary slices. Tissue:medium ratios of about 45:1 were obtained after a 30-min incubation. The process responsible for 3H-GABA uptake was temperature-sensitive and sodium-dependent. The kinetic constants of saturable GABA transport were: Km 4.141 microM and Vmax 0.973 pmol/min/mg protein, at 25 degrees C. The incorporation of GABA into anterior pituitary was inhibited by specific inhibitors of neuronal and/or glial uptake. The subcellular distribution of GABA was investigated by continuous sucrose density gradients and differential centrifugation. Most of the endogenous and labelled GABA was present in the soluble fraction. However, a small part of GABA was found in the particulate fraction. These observations indicate that the anterior pituitary gland is able to concentrate GABA which interacts with intracellular particles.

Animals↗
PubMed1994

[Liver transplantation of living donors: first experiences in Spain].

The shortage of pediatric donors with a significant mortality in the waiting list has moved to the development of new techniques of liver transplantation that allow the reduction in size of bigger grafts to make them fit in the abdominal cavity of the small children. The last advancement on these techniques has come with the use as a graft of a segment of liver removed from a living donor genetically related with the recipient. The preliminary studies of the candidates for living donors were started after getting an informed consent. The evaluation consisted basically in: liver function test, virological screening, chest x-ray, EKG, volumetric CT scan to ascertain liver size, doppler ultrasound, selective hepatic arteriography, anesthetic consult and psychiatric study. Two candidates were accepted as living donors. In both the segments II and III of the liver were removed. The surgical procedures of donation lasted around six hours and the two donors were discharges at the seventh day without complication. The living related liver transplant represents an option that contribute to reduce the pediatric waiting list. The advantages of this technique are: the procedure may be performed in an elective way at the time that is appropriate for the patient and providing a graft of uniformly high quality.

Angiography↗
PubMed1993

Liver transplantation in small babies.

Pediatric liver transplantation is an effective treatment for end-stage liver disease with 1- and 5-year survivals approaching 90% and 70%, respectively. Survival is influenced by the recipient's age, weight, primary disease, vascular malformations, and nutritional status. Younger patients weighing less than 13 kg are considered to be a high-risk group. The aim of this article is to evaluate the impact of this group of patients on the overall results of our pediatric liver transplant program. From January 1986 through January 1992 we performed 76 liver transplants in 59 pediatric patients. Sixteen received a second graft and a third was required in one. Fourteen patients weighed less than 13 kg (mean, 11 kg; range, 6 to 13 kg). Their mean age was 12 months, with a range of 8 to 36 months. Indications for transplantation were: biliary atresia (9), Byler's disease (1), tyrosinemia (3), and alpha 1-antitrypsin deficiency (1). The incidence of rejection in this group (52%) was not significantly different from that in other patients (61%). Ten episodes of acute rejection required only steroids: in one monoclonal antibodies were added. Five patients had a new graft implanted, four for hepatic artery thrombosis and one for primary liver nonfunction. Nine patients are alive (64%) with the follow-up time ranging from 2 to 56 months (mean, 31). Five patients died of multiorgan failure (3), portal vein thrombosis (1), and primary liver nonfunction (1). Four-year graft and patient survival rates were 47% and 64%, respectively. Small babies are a high-risk group in a pediatric liver transplant program.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Portal venous flow as a prognostic factor in biliary atresia. A preliminary study].

Early prognosis factors determination is an important objective after Kasai's operation for biliary atresia repair. Serologic test, postoperative biliary flow, histologic studies and clinical manifestations provides adjunctive information. Hemodynamic patterns in biliary atresia where described in 80's before liver transplantation. This preliminary report evaluates portal flow velocity, hepatic arterial resistance and portal calibre in these patients. A prospective sonographic investigation was performed in ten children with biliary atresia. Hemodynamic findings and hepatobiliary function were compared in order to establish prognosis. All our patients with good prognosis had hepatopedal portal flow greater than 14 cm/sg, and arterial resistance between 0.68-0.78. Four patients with poor prognosis had hepatopedal flow lesser than 14 cm/sg or hepatopedal flow an resistance in hepatic artery was greater than 0.80.

Biliary Atresia↗
PubMed1991

[Histopathology of biliary atresia: correlation with biliary flow].

The objective of KASAI's operation is to obtain a postoperative bile excretion and to maintain an internal biliary fistula. The purpose of this report is to study the relationship between the liver histopathology and the postoperative bile flow and survival. From july 1976 to january 1990, 66 patients underwent a corrective operation for biliary atresia. In 24 patients we performed a KASAI's operation with internalization of the biliary conduit, 36 with externalization, four gall-bladder KASAI and two liver biopsy. The mean age at operation was 66 days and postoperative bile excretion was obtained in 43 of them (66 per 100). The survival rate was 70 per 100. The liver histopathology shown: minimum portal fibrosis (7.8 per 100), moderate (49 per 100) and severe (43 per 100). We found bile ducts in 30 patients (46 per 100), in three bile ducts were less than 50 mu, in 15 between 50 and 100 mu and more than 100 mu in 12. We did not found statistic correlation between grade of liver fibrosis size of bile duct and postoperative flow. We found a statistic correlation between the presence of bile ducts and postoperative flow (p less than 0.05).

Anastomosis, Surgical↗
PubMed1990

Ethanol-related changes in substance P in the hypothalamus and anterior pituitary.

The effect of the administration of a rabbit anti-substance P serum (ASPS) was studied in rats receiving an acute injection of ethanol. ASPS lowered serum prolactin levels and reduced the hyperprolactinemia induced by ethanol. ASPS also decreased LH serum levels in both saline- and ethanol-treated rats. The effect of ethanol on the concentration of substance P-like immunoreactivity (SP-LI) in the mediobasal hypothalamus and the anterior pituitary gland was also investigated. Ethanol reduced SP-LI in the mediobasal hypothalamus but increased it in the anterior pituitary gland. The presence of ethanol (50 mM) did not affect the K(+)-evoked release of SP-LI from either mediobasal hypothalamus or anterior pituitary gland, though it increased the SP-LI concentration remaining in this gland. These results indicate that ethanol increases the content of SP-LI in the anterior pituitary gland and suggest that substance P may be involved in the prolactin release induced by the acute administration of ethanol.

Animals↗
PubMed1990

Vasoactive intestinal peptide affects the GABAergic system in the hypothalamic-pituitary axis.

The effect of a specific antiserum against vasoactive intestinal peptide (VIP) on GABA in the hypothalamic-pituitary axis was studied. The administration of anti-VIP serum (A-VIP) increased anterior pituitary GABA concentration in control rats, but decreased this neurotransmitter in rats with hyperprolactinemia induced by acute or chronic treatments with estrogens, or by the implanting of anterior pituitary glands under the kidney capsule. Besides, the injection of the A-VIP serum in the morning in proestrous rats causes a decrease in anterior pituitary GABA concentration, measured in the afternoon of the same day. The in vitro effect of A-VIP and VIP on endogenous GABA release from hypothalamic fragments and on anterior pituitary GABA concentration was studied. A-VIP increased both basal and high K(+)-evoked GABA effluxes whereas VIP produced a decrease in evoked GABA efflux from hypothalamic fragments. Furthermore, A-VIP inhibited the normal degradation of GABA that occurs in the isolated gland whereas VIP increased it. These results suggest that VIP modifies hypothalamic GABA release and anterior pituitary GABA concentration.

Animals↗
PubMed1990

Effects of serotonin on the hypothalamic-pituitary GABAergic system.

The effects of serotonin (5-HT) and its precursor, 5-hydroxytryptophan (5-HTP) on the GABAergic system in the mediobasal hypothalamus (MBH) and the anterior pituitary were studied. The IP administration of 5-HTP produced a transient increase (only at 45 min after the injection) in glutamate decarboxylase activity (GAD) of MBH and in GABA concentration in anterior pituitary. Besides, 5-HTP administration increased the in vitro evoked GABA release from MBH. The administration of 5-HTP to hypophysectomized rats partially reversed the inhibitory effects of hypophysectomy on GABA concentration in MBH. We also examined the direct effect of 5-HT on some parameters on the hypothalamic GABAergic system. The presence of 5-HT in the incubation medium increased GAD activity and evoked GABA release from MBH. These observations indicate that the serotoninergic stimulation of the hypothalamic GABAergic system could be a direct effect which may, at least partially, be independent of the feedback mechanism induced by prolactin on the GABAergic neurons. The serotoninergic increase of prolactin secretion could be accomplished through stimulation of the hypothalamic GABAergic transmission.

4-Aminobutyrate Transaminase↗
PubMed1990

GABA as a presumptive paracrine signal in the pineal gland. Evidence on an intrapineal GABAergic system.

GABA is present in the pineal gland of several mammals, where it is synthesized in situ as well as taken up from the circulation. This article reviews available information suggesting a local, physiological role of pineal GABA. Both the pinealocytes and the glial pineal cells have the capacity to take up GABA from the extracellular space. The GABA synthesizing enzyme glutamic decarboxylase (GAD) is detectable in the pineal gland; in the bovine pineal GAD exhibits "neuronal-like" properties. By employing a specific antibody against GABA, about 15% of pinealocytes gave a positive reaction in bovine pineal glands. After a depolarizing stimulus, GABA was released from bovine and rat pineal glands by both Ca2(+)-dependent and Ca2(+)-independent processes. By employing neuronal and glial GABA uptake inhibitors, most 3H-GABA release in bovine pineal gland could be attributed to a "neuronal" (presumably pinealocyte) compartment. Several components of the GABA type A receptor supramolecular complex (i.e., GABA binding sites, central-type benzodiazepine binding sites, Cl- ionophore), as well as a minor population of GABA type B receptor sites, were detected in bovine and human pineal glands. In the rat pineals, GABA is released by norepinephrine (NE) acting through alpha 1-adrenoceptors. Physiological concentrations of GABA, by its effect on type A receptor sites, impaired NE-induced melatonin release; by acting on GABA type B receptors, it decreased NE release. Another presumable presynaptic effect of GABA (i.e., to augment maximal velocity and to decrease affinity of NE uptake) was mediated by type A receptor sites. It is proposed that pre- and postsynaptic activity of GABA in the pineal does not differ from that found for GABA interneurons in local circuits of the brain.

Animals↗
PubMed1990

[The pediatric liver transplant. The surgical aspects].

The Liver Transplant Program was begun at "La Paz" Children's Hospital on January 1986 after a long period of experimental activities. This was the first experience in the Madrid Community. From January 1986 to June 1989 we made 32 orthotopic liver transplants in 25 patients, seven received a second graft and one them received a liver segment because the donor had a large liver. 114 patients were evaluated but only 84 were considered candidates for liver transplantation. The different diseases of the transplants were: biliary atresia (9), Alagille syndrome (4), deficit alpha 1-antitrypsin (3), autoimmune hepatitis (2), neonatal hepatitis (1), Byler disease (1), Wolman disease (1). absent bile ducts (1), Wilson disease (1). Surgical technique was the same that has been described by Starzl using Eurocollins and lactate Ringer. In the 100% we made multiorgan procurement, liver and kidneys, 7% with heart and two heart-lung with hypothermia. In one occasion the donor operation was done out of the country (RFA--Düsseldorf). We never used by-pass during anhepatic phase. Arterial reconstruction was done by end-to-end anastomosis and in five patients we used aortic graft. Our arterial thrombosis rate was 18%. In one patient the portal vein was atrophic and we used a femoral graft between superior mesenteric vein and donor portal vein. For biliary reconstruction we used Roux-en-Y with intraluminal stent in 18 cases and choledocho-choledochus anastomosis in seven cases. Four patients had biliary complications: two biliary fistulas secondary to arterial thrombosis, biliary stenosis and bowel perforation by the intraluminal stent.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗