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Biomedical subjects

J Ríos

Publications and source records attributed to J Ríos.

At least 19 recordsLinked to original sources

[New Modern Magpi: meatal advancement and glanuloplasty clinical course].

INTRODUCTION: Meatal advancement and glanuloplasty (MAGPI) described by Duckett, has been the most accepted technique for distal hypospadias repair along the last 20 years. Only 50% of the distal variants are amenable to the Magpi; last years several modifications has been reported in order to reach better cosmetic results and to make it available for the most of the distal hypospadias. We report the first 20 cases with some modifications of Magpi. MATERIALS AND METHODS: The basic steps of the technique are: we remove a triangular segment of glanular tissue distal to the meatus. Dissection of the dorsal and lateral urethral sides is made, accomplishing the urethral advancement without any tension. Strips of glandular epithelium are excised on each side, and glans tissue is sutured above the ventral urethral wall. RESULTS: There were 11 coronal, and 9 glanular hypospadias (3 with megameatus). 8 cases showed a slight incurvation that disappeared after releasing any cutaneous chordee. The posoperative follow-up was 35 weeks (R=7-48 weeks). Cosmetic and functional results were excellent, showing a natural circumcized penis. There wasn't any complications as meatal retraction, stenosis or incurvation. There was only a transitional hematoma and a minimal fistula that closed expontanely. CONCLUSIONS: New Modern Magpi adds minimal variations to the original technique, avoiding the cosmetic limitations derived from borderline indications. New Modern Magpi is amenable to near all of glanular hypospadias and most of coronal hypospadias.

Child, Preschool↗

Evolutionary Local Search of Fuzzy Rules through a novel Neuro-Fuzzy encoding method.

This paper proposes a new approach for constructing fuzzy knowledge bases using evolutionary methods. We have designed a genetic algorithm that automatically builds neuro-fuzzy architectures based on a new indirect encoding method. The neuro-fuzzy architecture represents the fuzzy knowledge base that solves a given problem; the search for this architecture takes advantage of a local search procedure that improves the chromosomes at each generation. Experiments conducted both on artificially generated and real world problems confirm the effectiveness of the proposed approach.

Algorithms↗

[Success of endoscopic management in vesicoureteral reflux, conditioned by ureteral dilatation].

INTRODUCTION: Endoscopic management has become an important alternative in the treatment of vesicoureteral reflux in children. Since 1995 we indicate it in our Hospital in children with grade II VUR (vesicoureteral reflux) after 1 year of medical management, in all children with grade III VUR and in children with grade IV VUR without reflux nephropathy. According to International Classification of reflux (IRSC), grade IV VUR differ to grade III mainly by the blunting of the calyces and the obliteration of sharp angle of the fornices. There may be seen in the high grades of reflux, important differences in the ureteral dilatation. AIM: The aim of this work is to study the influence of ureteral dilatation in the success of endoscopic management VUR. MATERIAL AND METHODS: A number of 245 refluxing renal units (URR) were treated endoscopically in our Hospital from 1995. We review the first 3.5 years (58 patients with 90 RRU). In a double blind study with the voiding cystourethrographies we graduated the ureteral dilatation in slight-normal, moderate and severe. The success rate after the first injection was compared between the 3 grades of ureteral dilatation. RESULTS: 3 patients had grade I VUR, 10 grade II, 54 grade III and 23 grade IV. After double blind study 39 patients had slight-normal ureteral dilatation, 39 moderate and 12 severe. There were statistical differences between the 3 grades of ureteral dilatation when we consider: all the patients, considering only grade III and IV reflux and studying only the patients with grade III reflux. However there wasn't statistical differences between grade III and IV VUR of the International Classification. CONCLUSIONS: The results show that ureteral dilatation is an important prognostical factor of the success rate in the endoscopic management of vesicoureteral reflux in children.

Child↗

[Ultrasound-guided hydrostatic reduction for the treatment of idiopathic intestinal invagination].

The more extended conservative treatment in intussusception consists of the accomplishment of fluoroscopy guided neumoenema. The development of the echography has allowed to introduce this as alternative in diagnosis and treatment of intussusception. Our objective is to analyze the therapeutic value of echography during resolution of intussusception with saline solution enema in pediatric patients. Intestinal intussusception was diagnosed in 183 patients by echography during a period of 7 years. Patients are classified in three groups according to treatment by means of opaque enema, radioscopy guided neumoenema or echography guided hydrostatic reduction enema. The results of the three series are analyzed: rate of failure of the procedure, the recurrences or the presence of complications. We exclude n = 18 patients that were operated on directly after the diagnosis. The reduction rate was 81.25% (9/16) with opaque enema; 94.6% (103/110) with neumoenema and 96.4% (27/28) with echography guided saline enema. Complications appeared in n = 2 cases of intestinal perforation, 1 with barium and 1 with air 2. Recurrences were n = 3, n = 2 with neumoenema and n = 1 with echography guided enema. Echography guide saline enema has a high security and effectiveness (96.4%), similar to the other methods, avoiding the exposition to ionic radiation. The technique is safe and it does not increase the rate of recurrences.

Child, Preschool↗

Aortic injury during diagnostic pediatric laparoscopy.

Major vascular injury during laparoscopic procedures is a rare but catastrophic complication. We report a pediatric case of aortic laceration during the setup phase of diagnostic laparoscopy in a 5-year-old girl with recurrent abdominal pain. The Veress needle inserted below the umbilicus confirmed the proper placement by use of a saline-filled syringe. The abdomen was insufflated without difficulty. The first trocar was inserted at the same point as Veress needle. The video laparoscope was introduced, and a small amount of blood was seen in the abdomen. We converted the procedure to laparotomy immediately. There was a large retroperitoneal hematoma. The vascular laceration was identified at the origin of the iliac arteries. It was sutured with prolene 5/0. The girl was discharged without further complication on the 10th postoperative day. The incidence of major vascular injuries is 0.03% to 0.07%. The vessels most frequently involved are the aorta, the iliac arteries, the mesenteric vessels, and the vena cava. More than 400 cases have been reported in the literature, but only four of these involve pediatric patients. In the vast majority of cases, the complication took place during the setup phase of laparoscopy (75%), and were related to the introduction of either the Veress needle (30%) or the first umbilical trocar (43%), although the rate is opposite this in some studies.

Aorta, Abdominal↗

The 5S rDNA of mussels Mytilus galloprovincialis and M. edulis: sequence variation and chromosomal location.

The 5S ribosomal DNA of the mussels Mytilus galloprovincialis and M. edulis was amplified by PCR using contiguous primers. The most general 5S rDNA amplification pattern consisted of several products in both mussels. Two main PCR products of about 250 bp and 760 bp were cloned and sequenced, revealing two classes of 5S rDNA units. These were characterized as containing an identical coding region of 119 bp but with highly divergent spacers. Clones of each unit type exhibited minimal differences except those of the large unit of M. edulis. The sequences analysed of the two mussels possess the same coding region and only six fixed base changes on the spacers. FISH, carried out with specific probes, consistently showed hybridization signals on the largest metacentric pair (two differentiated sites) and with variable frequency on two other metacentric pairs (one site on each pair). Differences in the 5S rDNA distribution between both mussels were not found. In M. edulis, chromosomes carrying 18S-28S rDNA were also identified by FISH. These correspond to two submetacentric-subtelocentric pairs, as was previously reported in M. galloprovincialis, demonstrating that the two rDNA multigene families are located on different chromosome pairs in these mussels.

Animals↗

Nitrendipine and enalapril combination therapy in mild to moderate hypertension: assessment of dose-response relationship by a clinical trial of factorial design.

Hypertension is an important cardiovascular risk factor and the goal of its pharmacologic treatment is to reduce morbidity and mortality. Treatment is usually initiated with a low dose of a single agent and titrated to a higher dose as required. As many as 50% of patients require the addition of a second agent to achieve satisfactory blood pressure control. The aim of this study was to assess the dose-response relationship of nitrendipine and enalapril alone or in fixed combination in the treatment of mild to moderate hypertension. A total of 496 patients were enrolled in a multicenter, randomized, double-blind, factorial-design, parallel-group clinical trial comparing placebo, nitrendipine (5, 10, and 20 mg) and enalapril (5, 10, and 20 mg) alone or in combination. After a single-blind, 2-week placebo run-in period, 414 patients whose diastolic blood pressure ranged between 90-109 mm Hg were randomly assigned to a treatment group. The combination of nitrendipine and enalapril, particularly regimens including nitrendipine 20 mg and enalapril 5 or 10 mg, were significantly superior to both monotherapies; mean diastolic blood pressure reductions from baseline to last visit were -12.5 and -14.3 mm Hg, respectively. Response surface analysis provided further evidence that these combinations were optimal in terms of anti-hypertensive efficacy. All treatments were well tolerated and the incidence of adverse events did not differ significantly between groups. In summary, the anti-hypertensive efficacy of the combination was found to be superior to both monotherapies at any doses. The dose combination achieving the greatest blood pressure reduction was nitrendipine 20 mg and enalapril 10 mg.

Adolescent↗

[Clinical patterns of soft-tissue sarcoma in children].

INTRODUCTION AND OBJECTIVES: Soft tissue sarcomas are rare mesenchymal neoplasms that constitute less than 10% of all pediatric malignancies. Half of these are rhabdomyosarcomas, the remaining 50% have a varied and heterogenous histologic and clinical patterns (fibrosarcoma, synovial cell sarcoma, extraskeletal Ewing's sarcoma, angiosarcoma, liposarcoma, leiomyosarcoma, ...). The purpose of this work is to evaluate our clinical experience with soft tissue sarcomas in uncommon sites over the past 10 years in order to delimitate the prognostic factors in survival and modalities of treatment. MATERIAL AND METHODS: Between 1989 and 1998, 10 patients were diagnosed with soft tissue sarcomas in uncommon sites and treated by us over a total number of 139 pediatric neoplasms (7.19%). Data on these patients were obtained from careful review of medical records. Variables investigated included histologic findings, tumor size, age at presentation, primary site, clinical group, radiologic test performed, surgical treatment, radiotherapy and adjuvant chemotherapy, complications and survival rates. Charts were registered in database Access. Statistical analysis was performed by the SPSS 8.0 statistical program. RESULTS: The following histologic types of these 10 tumors were identified: 1 hemangiopericytoma in oral cavity, 2 extraosseous Ewing's sarcoma, 1 botryoid rhabdomyosarcoma of the bladder, 1 mediastinal fibrosarcoma, 1 retroperitoneal rhabdomyosarcoma, 1 paratesticular rhabdomyosarcoma, 1 cervical condrosarcoma, 1 alveolar rhabdomyosarcoma and 1 deltoid rhabdomyosarcoma. 50% were rhabdomyosarcomas and the remaining 50% have a variated sarcomatous histologic pattern with a difficult classification. The mean age at diagnosis was 7 years (4.6 years accounted for rhabdomyosarcoma alone). Surgery with complete excision were performed only in six cases. Adjuvant chemotherapy with IVA was followed by radiotherapy only in four patients. All the children classified in clinical groups II, III or IV needed 2nd. line regimens of chemotherapy. Three patients died in the follow-up instead of the multimodal treatment. Survival ranged from 6 months to 9 years (mean 4 years). CONCLUSIONS: The impact of surgical resectability on outcome in these tumors has been clearly demonstrated over other factors like histologic appearance. Distant metastasis are infrequent but local recurrence are a constant in all cases with incomplete surgical resection. Based on those facts we could advanced an adequate approach to this kind of neoplasms: 1) wide complete surgical resection is mandatory; 2) radiotherapy will only be necessary if margins of resection cannot control the local disease, and 3) chemotherapy have not clearly demonstrated his benefits as adjuvant therapy in clinical group I lesions but his employ is recommended in all cases because of the poor prognosis due to local recurrence.

Adolescent↗

Effect of triterpenoids on the inflammation induced by protein kinase C activators, neuronally acting irritants and other agents.

In order to establish the mode of the anti-inflammatory activity of triterpenoids, 11 naturally occurring compounds were assayed on mouse ear oedema induced by the protein kinase C activators, mezerein, 12-O-tetradecanoylphorbol-13-acetate (TPA), two 12-deoxyphorbol-13-monoesters (13-tetradecanoate (DPT) and 13-phenylacetate (DPP)) and bryostatin 1, and by resiniferatoxin, xylene and arachidonic acid. The effects on bradykinin-induced paw oedema and on the rat skin inflammation caused by hydrogen peroxide were also examined. The oedema induced by mezerein and DPT was reduced to different extents by the triterpenoids administered epicutaneously (0.5 mg per ear). Against DPT-induced oedema, lupane and oleanane derivatives were the most effective compounds. Oleananes and lupanes possessing a carboxyl group were active against bryostatin 1-induced oedema. Most of the triterpenoids were ineffective against the neurogenic inflammation caused by resiniferatoxin and xylene. Many triterpenoids, especially oleanane and lupane alcoholic derivatives, were active against the plantar oedema induced by bradykinin and on the intradermal inflammation induced by hydrogen peroxide. In conclusion, the anti-inflammatory activity of triterpenoids may depend on inhibition of protein kinase C, without any involvement of neurogenic inflammatory mechanisms.

Animals↗

Anti-inflammatory glycoterpenoids from Scrophularia auriculata.

The activity of the four glycoterpenoids: two saponins, verbascosaponin A and verbascosaponin, and two iridoids, scropolioside A and scrovalentinoside, isolated from Scrophularia auriculata ssp. pseudoauriculata, were studied in different models of acute and chronic inflammation. Both saponins significantly inhibited the mouse paw edema induced by carrageenan and ear edema induced by single and multiple doses of 12-O-tetradecanoylphorbol 13-acetate (TPA). Verbascosaponin A showed a potency twice as high as that of indomethacin in the acute TPA model. Verbascosaponin A and scropolioside A were active after a long latency period against ethyl phenylpropiolate edema, as are glucocorticoids. When the putative corticoid-like mechanism of the two compounds was studied, verbascosaponin A activity was notably reduced by the mRNA synthesis inhibitor, actinomycin D, while the effect of scropolioside A was partially interfered with by the anti-glucocorticoid drugs used. Both iridoids were active on the delayed type hypersensitivity reaction. They significantly reduced the inflammatory lesion and suppressed the cellular infiltration.

Animals↗

Acute scrotum: an exceptional presentation of acute nonperforated appendicitis in childhood.

Acute scrotum is an exceptional form of presentation of acute appendicitis in the pediatric age group. Only 14 cases have been described in literature. The authors report a case of an 8-year-old boy with a 12-hour history of right hemiscrotal pain secondary to acute retrocecal nonperforated appendicitis. Surgical exploration showed a patent "processus vaginalis."

Acute Disease↗

Calcium-activated chloride currents and non-selective cation channels in a novel cystic fibrosis-derived human pancreatic duct cell line.

The modulation of ion fluxes across the plasma membrane of epithelial cells is central for fluid secretion and absorption. Their disruption can lead to pathological states. An example is cystic fibrosis (CF), a disease characterized by abnormal functioning of the cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-modulated chloride channel. Here we report the characterization of calcium-activated, DIDS sensitive chloride current and non-selective calcium-activated cation channels in a novel human pancreatic duct cell line (YHV-1) derived from a non-delta F508 mutation CF patient bearing a severe phenotype. Southern blot analysis of the CFTR gene indicates a distinct electrophoretic pattern for the region spanned by exons 15-24, a result presumably related to a mutation which has yet to be identified. In contrast to large calcium-activated chloride currents there were no cAMP-dependent CFTR-type chloride currents. Non-selective cation channels were blocked by intracellular ATP and activated by intracellular calcium and cAMP. We propose the cell line YHV-1 as a suitable model for studying pancreatic ion and fluid secretion alterations in CF.

Blotting, Southern↗

[Molecular genetic analysis of 2 Chilean cystic fibrosis patients and their families].

As a contribution to establish the real incidence of cystic fibrosis (CF) and the prevalent mutations in the Chilean population a method for the detection of delta F-508 and R-553X, two of the most frequent mutations described worldwide, has been implemented. The method is based on the polymerase chain reaction (PCR) amplification of DNA followed by allele specific restriction enzymatic digestion. The application of this techniques allowed to confirm CF diagnosis in two patients and to detect asymptomatic carriers in both families. One of the patients showed normal sweat electrolyte concentration.

Child↗

[Bactericidal spectrum of pyocins on strains collected at Region IX and X hospitals in Chile].

The inhibitory effect of 5 pyocins produced by wildstrains of Ps aeruginosa was tested by qualitative and quantitative techniques. 313 strains of 4 species: E coli, P vulgaris, Ps aeruginosa and St aureus were assayed. It was shown that the most active pyocin was P37, which inhibited 276 out of 313 strains tested. About 80% of E coli and 90% of St aureus strains were inhibited by the pyocins under being tested. It was established that sensitivity to pyocin was not restricted to close-related species but extends to unrelated families also.

Bacteriocins↗

Effect of ascorbic acid on the hepatotoxicity due to the daily intake of nitrate, nitrite and dimethylamine.

It is known that nitrates, nitrites and dimethylamine may react in the gastro-intestinal tract synthesizing the powerful hepatotoxic and carcinogenic dimethylnitrosamine. The purpose of this study was to investigate hepatotoxicity due to the daily intake of nitrates and nitrites administered to rats during 14 weeks together with dimethylamine in drinking water, and to evaluate the protecting effect of ascorbic acid against the hepatotoxicity of the presumably endogenous formed dimethylnitrosamine. The toxicity criteria studied were weight of liver (absolute and relative), free and total bilirubin, alkaline phosphatase and pyruvic glutamic transaminase, all in the form of serum, and histopathologic tests of the liver. The results gave evidence of hepatotoxicity induced by the intake of nitrate, nitrite and dimethylamine all together, and not through the only intake of nitrate or nitrite or of amine. Daily doses of ascorbic acid [(211 +/- 40) and (18 +/- 4) mg/kg] seemed to hinder hepatotoxicity according to the criteria under investigation.

Alanine Transaminase↗

Screening for red blood cell sorbitol dehydrogenase deficiency in patients with diabetes or cataracts.

Quantitative screening for red blood cell sorbitol dehydrogenase (RBC-SORD) deficiency in 111 patients with juvenile onset diabetes, 92 patients with adult onset diabetes, 42 patients with idiopathic cataracts and 192 professional blood donors was performed. A wide variability in RBC-SORD activity in controls and patients was observed. No significant differences in SORD activity either between patients with diabetes and patients with idiopathic cataracts or between diabetics with and without cataracts were observed. Whether or not there were carriers for either amorphous or hypomorphous alleles of the SORD locus in the population studied could not be defined in terms of enzymatic activity levels.

Cataract↗