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Biomedical subjects

J C Coelho

Publications and source records attributed to J C Coelho.

At least 37 records · Page 2Linked to original sources
PubMed1997

Neurological dysfunction in methylmalonic acidaemia is probably related to the inhibitory effect of methylmalonate on brain energy production.

Methylmalonic acidaemia is an inherited metabolic disorder caused by a severe deficiency of the activity of the enzyme L-methylmalonyl-CoA mutase or its cofactor 5'-deoxyadenosylcobalamin, resulting in tissue accumulation of large quantities of methylmalonic acid. Among the various clinical features, neurological symptoms are frequently observed. Patients may present cerebral atrophy and basal ganglia abnormalities are common. In the present report, we update the current knowledge on the influence of methylmalonic acid on brain metabolism in the hope of better understanding the neurological dysfunction characteristic of methylmalonic acidaemia. We present evidence showing that the metabolite inhibits brain energy production by various mechanisms and propose that a fall in cellular ATP generation leading to excitotoxicity is crucial for the occurrence of the neurological damage observed in these patients.

Adenosine Triphosphate↗
PubMed1997

Evaluation of an aspartame loading test for the detection of heterozygotes for classical phenylketonuria.

Classical phenylketonuria (PKU) is an inborn error of metabolism of autosomal recessive inheritance characterized by the accumulation of phenylalanine (Phe) in tissues due to Phe-4-hydroxylase deficiency. Several methods have been developed for the detection of PKU heterozygotes based on the determination of plasma Phe and tyrosine (Tyr) levels, on the analysis of the Phe/Tyr and Phe2/Tyr ratios and on the use of discriminant functions. The objective of the present study was to test the value of loading with aspartame (a sweetener consisting of Phe, aspartate and methanol) for the identification of PKU carriers. The study was conducted on 22 obligate heterozygotes and 27 controls. Two blood samples were collected (under fasting conditions and 30 min after the loading) for fluorometric determination of Phe and Tyr. Phe, Phe/Tyr and Phe2/Tyr values were higher in heterozygotes, whereas Tyr was higher in controls in both situations investigated. Linear discriminant function was considered to be the best parameter for differentiation of the individuals in the two groups. Under the conditions employed in the present study, aspartame loading did not show any advantages in discriminating between PKU carriers and normal individuals when compared to the same analysis performed under fasting conditions.

Aspartame↗
PubMed1997

Detection of metabolic disorders in high-risk patients. A pilot study in Salvador, Bahia.

The purpose of this pilot-study was to evaluate the applicability of a screening protocol for the detection of inborn errors of metabolism (IEM) in high-risk patients. The protocol was applied in 65 patients referred to the Medical Genetics Laboratory of the University Hospital Professor Edgard Santos due to the suspicion of an IEM. Eight of these patients (12.3%) displayed an abnormal result in the screening protocol. These patients, along with 22 who displayed normal results in the screening protocol but who presented clinical symptoms or signs suggestive of an IEM not detectable by the tests applied, were selected for a further diagnostic investigation. In 5 of these 30 patients (7.7% of the total sample) it was possible to establish the diagnosis of an specific IEM. The results indicate that the designed screening protocol was successfully applied, allowing the detection of affected patients in a frequency comparable to that observed in larger studies performed elsewhere. The continuation of this study and the enlargement of the sample will help to delineate the profile of IEM in northeast of Brazil and will allow the identification of a significative number of patients and families, who could benefit from the therapeutic and preventive measures available for these diseases.

Amino Acids↗
PubMed1996

Motility of Oddi's sphincter: recent developments and clinical applications.

BACKGROUND: In recent years, applications of electromyographic, cineradiographic, scintilographic, and endoscopic manometric techniques have improved our knowledge of normal and abnormal motility of Oddi's sphincter. This sphincter coordinates the time and rate of secretion of about 3 liters of bile and pancreatic juice into the duodenum daily. METHODS: Oddi's sphincter may be evaluated by endoscopic manometry, ultrasound, dynamic hepatobiliary scintigraphy, and laboratory tests. Endoscopic manometry is the best method for evaluating the function Oddi's sphincter. RESULTS: The basal pressure of Oddi's sphincter is usually 5 to 15 mm Hg greater than the bile and pancreatic duct pressures. Phasic contractions of 50 to 150 mm Hg in amplitude and 3 to 8 contractions per minute in frequency are superimposed on the basal pressure. A small percentage of patients with gastrointestinal symptoms after cholecystectomy has sphincter of Oddi dysfunction, which may have structural abnormality (papillary stenosis) or functional abnormality (Oddi's sphincter dyskinesia). CONCLUSIONS: Elevated basal pressure ( > 40 mm Hg) is the most important manometric finding of Oddi's sphincter dysfunction. Endoscopic sphincterotomy is the treatment of choice for patients with Oddi's sphincter dysfunction and elevated basal sphincter pressure.

Biliary Tract Diseases↗
PubMed1996

Factors influencing outcome in patients with gastrointestinal fistula.

The analysis of the prognostic factors in patients with gastrointestinal fistula requires an assessment of the quantitative and qualitative characteristics of the study population. General patient characteristics such as age, presence and degree of malnutrition, levels of plasma proteins, diagnosis of cancer or inflammatory bowel disease, or systemic sepsis must be considered, as well as local fistula characteristics. Besides the local anatomic characteristics of the fistulous tract, other factors such as fistula output, organ of origin, cause, and duration of the fistula must be considered in the assessment of a fistula patient. It is recognized, however, that it is very difficult to conclude that the presence of a single prognostic factor increases the risk in patients as complex and heterogeneous as those with digestive fistulas. It remains to be shown whether the combination of several predictive factors may enhance the chances of accurately predicting fistula closure and mortality in digestive fistulas.

Fistula↗
PubMed1996

Extrapyramidal disorder secondary to cytomegalovirus infection and toxoplasmosis after liver transplantation.

A boy underwent liver transplantation for postnecrotic cirrhosis secondary to Wilson's disease. The patient had no neurological clinical manifestations prior to the transplantation. The patient developed dysarthria, dysphagia, spasticity, rigidity, and intention and resting tremor of all extremities. Cranial computerized tomography revealed hypodensity of the thalamus, basal ganglia and external capsule. Anti-cytomegalovirus IgM became positive. At autopsy, there were severe pathological changes at the thalamus and basal ganglia.

Adolescent↗
PubMed1994

Possible high frequency of tetrahydrobiopterin deficiency in south Brazil.

We report our experience with the deficiency of 6-pyruvoyltetrahydropterin synthase, the most common form of tetrahydrobiopterin deficiency. We investigated 5200 patients suspected of having some inborn error of metabolism in a 10-year period, and detected 30 cases (from 28 sibships) of hyperphenylalaninaemias, HPA. From these, 4 sibships (5 patients) were affected by deficiency of 6-pyruvoyltetrahydropterin synthase. All of them were ethnically mixed, with some European ancestry detected in all. The age of diagnosis ranged from 2 to 9 years, and all were initially referred for investigation by having mental retardation and seizures. All of them showed low urinary biopterin levels and a marked elevation of neopterin. Although we detected only a few cases of HPA (30), 5 cases of 6-pyruvoyltetrahydropterin account for almost 20% of this total. The literature, however, reports a proportion of around 0.5%. As the frequency of classical phenylketonuria in our region is similar to that found in Caucasians (1/12,500), we believe that the frequency of this disease in South Brazil may be higher than expected (of the order of 1/400,000). We speculate that this finding could be related to a genetic drift (or founder effect).

Amino Acid Metabolism, Inborn Errors↗
PubMed1994

[Acute pancreatitis caused by varicella-zoster virus after liver transplantation].

Twenty-six days after liver transplantation for primary biliary cirrhosis, a 52 year-old patient was rehospitalized for viral infection. The clinical features were fatigue, anorexia and vomiting. On physical examination, vesicular skin lesions involving the left 8 th intercostal space were suggestive of herpes-zoster infection. The following day the patient was extremely tired and dyspnoeic. The abdomen was distended with moderate abdominal epigastric pain. The clinical picture worsened rapidly and the patient died a few hours later. Autopsy revealed acute haemorrhagic necrosis of the pancreas due to herpes-zoster virus.

Acute Disease↗
PubMed1993

Electromyographic evaluation of the gastrointestinal tract in dogs with short bowel syndrome.

Seven dogs were subjected to resection of 80% of the total length of the small bowel. Seven pairs of electrodes were implanted in the seromuscular layer of the antrum and remaining small bowel. Electromyographic recordings were obtained during fasting and after milk ingestion. Slow waves were identified in all sites studied and their frequencies were 4.7 +/- 0.4/min in the antrum; 17.5 +/- 0.58/min in D1; 17.5 +/- 0.61/min in D2; 17.43 +/- 0.65/min in J1; 17.40 +/- 0.62/min in J2; 10.28 +/- 0.77/min in I1; and 9.81 +/- 0.53/min in I2. The phase III of the migrating motor complex was identified in only one recording. Ingestion of milk caused the appearance of the fed pattern in all recording sites, except the antrum. It is concluded that extensive resection of the small bowel causes reduction of the slow wave frequency in the gut distal to the resection and disappearance of phase III of the migrating motor complex.

Animals↗
PubMed1990

Evaluation of preoperative hospitalization duration in skin flora.

The skin microbial flora of 18 patients was evaluated during prolonged preoperative hospital stay. Five cultures for bacteria and fungi were obtained on different days: on admission one, three and seven days after admission and after skin disinfection with povidone-iodine solution. There was no change in the mean bacterial count from the admission day to seven days after admission. All but one culture obtained following skin disinfection were negative. Pathogenic bacteria were isolated in only one of each of the following culture day: admission, three and seven days after admission. All cultures were negative for yeasts. The findings suggest that the higher rate of wound sepsis observed in patients with long preoperative hospitalization may not be due to bacterial flora change.

Abdomen↗
PubMed1990

Electromyographic evaluation of the gastrointestinal tract in patients with chronic Roux-en-Y limb.

Recently, a Roux-en-Y stasis syndrome was described in a few patients after gastric operations. Although the clinical long term results are usually good, the motility of Roux-en-Y biliary limb has not been evaluated yet. In the present study, we report electromyographic studies of the gastrointestinal tract of two patients with chronic Roux-en-Y hepaticojejunostomy. These two patients provided a unique opportunity to evaluate the electromyographic activity of chronic Roux-en-Y limb in humans after one to five years. Seven pairs of bipolar extracellular electrodes were implanted in the antrum, duodenum, proximal part of the jejunum (15 centimeters proximal to the jejunojejunostomy), distal part of the jejunum (15 centimeters distal to the jejunojejunostomy), ileum, proximal Roux-en-Y limb and distal Roux-en-Y limb. All four phases of the migrating motor complex (MMC) were identified in the antrum and small intestine, including the Roux-en-Y limb, almost simultaneously to phase III in the duodenum. In the other two recordings (25 per cent), there was no relationship between phase III in the Roux-en-Y limb and that in the duodenum. Ingestion of food caused substitution of the MMC by the fed activity pattern in all recordings in the antrum and small intestine, including the Roux-en-Y limb. The findings of the present study indicate that the electromyographic activity of the Roux-en-Y limb may remain normal during fasting and fed states even many years after its creation.

Adult↗
PubMed1987

The effect of preoperative internal and external biliary drainage on mortality of jaundiced rats.

Mortality following abdominal infection induced by cecal ligation and puncture was studied in rats with obstructive jaundice and after relief of the obstruction by preoperative internal or external biliary drainage. Four groups of adult Sprague-Dawley rats were used: common bile duct ligation (BDL), BDL followed by internal drainage after two weeks, BDL followed by external drainage after two weeks, and sham operation. The serum bilirubin concentration was significantly increased in the BDL group and returned to normal following internal and external drainage. Mortality in the sham group was 16.5% and increased to 83.3% following BDL, but it decreased significantly (25%) to near-normal values after preoperative internal drainage. However, after external drainage no significant reduction in mortality (63%) was found. These findings confirm the poor results of preoperative external drainage in previous studies and establish the efficacy of internal biliary drainage in a well-controlled experimental model that has to be evaluated in the clinical situation.

Animals↗
PubMed1987

Certain aspects of normal and abnormal motility of sphincter of Oddi.

Applications of electromyographic and endoscopic manometric techniques in experimental and clinical studies have enhanced our knowledge of the normal physiology and motility disturbances of the sphincter of Oddi. The sphincter of Oddi has an active role in coordinating the time and rate of secretion of biliopancreatic juice into the duodenum. In the opossum, the sphincter of Oddi exhibits spontaneous contractions that migrate distally along the sphincter and expels its contents into the duodenum. Although the motor activity of the sphincter of Oddi is independent from that of the duodenum, there is a correlation between the frequency of bursts of spike potentials in the sphincter of Oddi and the migrating motor complex phases in the duodenum. Abnormal motility of the sphincter of Oddi has been reported during endoscopic manometric evaluation of patients with choledocholithiasis and sphincter of Oddi dyskinesia. Patients with common bile duct stones have an increase in the frequency of retrograde propagation of phasic waves. Elevation of basal pressure as well as an increase in the frequency and amplitude of sphincter of Oddi phasic waves and the common bile duct-duodenum gradient pressure may occur in patients with sphincter of Oddi dyskinesia. Endoscopic manometric studies of the sphincter of Oddi may become an important method to diagnose sphincter of Oddi dyskinesia.

Ampulla of Vater↗
PubMed1987

Effect of nifedipine on the motility of the sphincter of Oddi and small bowel of the opossum.

The effect of the calcium-channel blocker nifedipine on the electromyographic activity of the small bowel and sphincter of Oddi was studied in conscious opossums. Electromyographic and arterial pressure recordings were started 7-10 days after implantation of seven pairs of electrodes along the small bowel and sphincter of Oddi. Continuous infusion of nifedipine caused a dose-dependent reduction of the frequency of spike bursts in the small bowel and sphincter of Oddi. Nifedipine at high doses abolished the migrating motor complex in the gastrointestinal tract. The frequency of slow waves was unchanged. This drug possibly inhibits the membrane influx of calcium into the smooth muscle cells of the gastrointestinal tract. We conclude that nifedipine causes an intense decrease in the motility of the small bowel and sphincter of Oddi.

Ampulla of Vater↗
PubMed1987

Intestinalization of pancreatic fragments in dogs: improvement in survival rate after acute segmental pancreatitis.

Intestinalization, a new method of pancreatic preservation in which vascularized pancreatic fragments are placed inside a jejunal pouch, has been tested for its effectiveness in the prevention of shock and death due to segmental pancreatitis. Intestinalization of the fragment resulted in the survival of eight of nine animals (89 percent) in which recovery was uneventful, whereas animals with pancreatitis in situ or in a mobilized fragment without intestinalization had a mortality rate of 100 percent within 2 days. We conclude that intestinalization ameliorates the outcome of hemorrhagic pancreatitis in the pancreatic fragment by effectively draining toxic products. The procedure may also be useful in pancreatic transplantation since no reintervention is necessary if graft failure or rejection occurs because the pancreas is accessible by endoscopy.

Animals↗
PubMed1987

Calcium-induced contraction and contractile protein of gallbladder smooth muscle after high-cholesterol feeding of prairie dogs.

Feeding a high-cholesterol diet to prairie dogs causes a reduction in contractile responses of gallbladder smooth muscle from these animals. In this study, the influence of cholesterol feeding on the contractile response to calcium and on the concentration of the contractile proteins actin and myosin was determined. Strips of gallbladder smooth muscle, at their optimal length for tension development, were stimulated maximally with carbachol. Then the muscle cell membranes were made permeable and strips were exposed to a maximally effective concentration of calcium. Strips from cholesterol fed animals developed less stress than those from control animals under all conditions. The concentration of actin and myosin was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. There were no differences in the concentrations of either protein between the cholesterol-fed and control animals. Our results indicate that the decreased contractile response seen in muscle from cholesterol-fed animals is not due to alterations in membrane excitation, excitation-contraction coupling, or in total contractile proteins.

Actins↗
PubMed1986

Effect of feeding on myoelectric activity of the sphincter of Oddi and the gastrointestinal tract in the opossum.

The effect of different foods on the myoelectric activity of the sphincter of Oddi and gastrointestinal tract was evaluated in the opossum. Gallbladder pressure was also recorded. Feeding fat and mixed food resulted in the greatest incidence of spike activity in the duodenum and jejunum, followed by protein. The lowest incidence of slow waves with spikes in the duodenum and jejunum followed feeding of carbohydrates (P less than 0.01). Likewise, the lowest spike activity in the sphincter of Oddi was observed after carbohydrate feeding (P less than 0.05). There was no significant difference in the incidence of spike potentials in the sphincter of Oddi when fat, protein, or mixed food was fed. No significant change in gallbladder pressure during fasting and following feeding of different aliments was observed. We concluded that there is a correlation between the frequency of spike potentials in the sphincter of Oddi and in the small bowel following feeding. The duration of the fed pattern for each type of food correlated with the number of spikes in the sphincter of Oddi and gastrointestinal tract.

Ampulla of Vater↗