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Biomedical subjects

M C Machado

Publications and source records attributed to M C Machado.

At least 19 recordsLinked to original sources
PubMed1995

Splenic abscess.

Explore the source record for details and available documents.

Abdominal Abscess↗
PubMed1995

Effect of PAF antagonists on cerulein-induced pancreatitis.

The present study was undertaken to investigate the involvement of PAF in acute pancreatitis induced by cerulein in rats. Cerulein (two doses of 20 micrograms/rat, the first s.c. and the second i.v., 1 h apart) induced a significant increase in vascular permeability in the pancreas, evaluated by the Evans blue (EB) extravasation method. Plasma amylase levels were also significantly increased in this group. The PAF antagonists, BN-52021 (5 mg/kg) and WEB-2170 (1 and 10 mg/kg), both significantly reduced the extravasation of EB in the pancrease induced by i.v. injection of PAF (1 microgram/kg). At these concentrations, BN-52021 was effective at inhibiting cerulein-induced pancreatitis (60-70% of inhibition) whereas WEB-2170 had no significant effect. Although the inhibition induced by BN-52021 suggests the involvement of PAF in cerulein-pancreatitis, the lack of effect of WEB-2170 reported here does not allow a definite conclusion. Further studies are needed to elucidate the differential effect of the PAF antagonists.

Acute Disease↗
PubMed1995

Nodular form of local hepatic tuberculosis: case report.

The nodular form of hepatic tuberculosis (TB) is a very uncommon disease characterized by coalescing tubercles to form tumour-like tuberculomas or abscesses without evidence of extrahepatic tuberculosis. Since 1950, 23 cases of isolated nodular TB in the liver have been reported in the world literature. In 19 of these cases laparotomy was performed and the correct diagnosis was obtained only on histologic examination. We report one additional case of multiple tuberculous abscesses which were initially diagnosed as hepatic abscesses and at intraoperative evaluation were thought to be a liver tumour. The diagnosis was made by histological examination with identification of acid-fast bacili.

Diagnosis, Differential↗
PubMed1995

Reduction of pancreatic enzyme content and mortality in experimental acute pancreatitis in rats.

A previous report has shown that undernutrition reduces the mortality of acute experimental pancreatitis probably by decreasing pancreatic enzyme content. Cerulein in physiological doses reduces the enzyme content of the pancreas without any harmful effect on the organ. The aim of the present study was to asses the effect of acute reduction of pancreatic enzyme content on the outcome of acute pancreatitis. Two groups of male Wistar rats weighing 230-250 g were studied: group I, 12-h fasted animals, and group II, ad libitum-fed animals who received cerulein at the inframaximal dose (0.2 microgram kg-1 h-1) for 2 h. Cerulein administration resulted in the reduction of the pancreatic contents of chymotrypsinogen (71%), trypsinogen (55%), proelastase (60%), amylase (62%) and cathepsin B (45%) (P < 0.05). However, no significant reduction in pancreatic phospholipase content was observed. Acute pancreatitis was induced in group I after 12-h fasting and in group II at the end of cerulein infusion by retrograde injection o 0.5 ml of 2.5% Na+ taurocholate into the pancreatic duct. Ascites volume and the degree of histologically observed lesions were similar in both groups, but 72-h mortality was 56% in the control group (10/ 18) and 23% (5/22) in the cerulein group (P < 0.05). We speculate that the reduction of pancreatic enzyme content may exert its beneficial effect in acute pancreatitis by decreasing the quantity of pancreatic enzymes reaching the circulation and consequently their pathogenic effects.

Acute Disease↗
PubMed1993

Mononuclear phagocytic system in acute pancreatitis.

1. Functional alterations of the mononuclear phagocytic system (MPS) may be an important factor in the pathogenesis of infection in acute pancreatitis (AP). In the present study, MPS activity was investigated in rats and hepatic blood flow (HBF) was also determined. 2. A total of 122 male Wistar rats were divided into three groups: 1, AP group (N = 51); 2, sham-operated (SO) (N = 49); 3, intact group (IG) (N = 22). AP was induced by retrograde injection of 0.5 ml of 2.5% sodium taurocholate saline into the main biliopancreatic duct under ketamine chloride anesthesia. SO animals were submitted to the same surgical steps as AP animals except for AP induction. 3. Each experimental group was subdivided into two subgroups. The first subgroup was submitted to the study of MPS activity as follows: each group was injected with colloidal 198Au and liver clearance parameters were determined 2 h (N = 11), 12 h (N = 10) and 24 h (N = 10) later in the AP group, and 2 h (N = 9), 12 h (N = 10) and 24 h (N = 11) later in the SO group. In the second subgroup, HBF was assessed using 131I-bromosulphalein at 2 h (N = 10) and 24 h (N = 10) in the AP group and at 2 h (N = 10) and 24 h (N = 10) in the SO group. The IG was submitted to both radioactive tracer studies. Each animal was used for only one experiment.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1991

Doppler demonstration of cystic vein dilatation secondary to portal vein thrombosis.

High-resolution duplex ultrasound was used to demonstrate vascular dilatation in the gallbladder wall in eight patients with portal vein thrombosis. Gallbladder thickening, combined with a higher incidence of gallstone disease in patients with chronic hepatic disease can be misinterpreted as acute cholecystitis. The Doppler is helpful in detecting the vascular cause of the gallbladder wall thickening thus helping to reduce the frequency of inappropriate cholecystectomy.

Dilatation, Pathologic↗
PubMed1991

Modifications of tissue blood flow in acute pancreatitis.

1. Acute pancreatitis (AP) was induced by ductal injection of 2.5% sodium taurocholate saline solution. Plasma and red blood cell (RBC) volume and visceral organ blood flow were evaluated by a radioisotopic method (51Cr tracers) in 45 adult male Wistar rats (22 submitted to AP and 23 controls) 4 h after AP induction. 51Cr-albumin was used to measure plasma volume and 51Cr-RBC was used to measure RBC volume. 2. Changes in tissue hematocrit reflect alterations in tissue blood flow, since reduction in blood flow increases microvascular erythrocyte sequestration. To evaluate the tissue blood flow, we introduce a "tissue hematocrit index" calculated by relating 51Cr-RBC and 51Cr-albumin specific activities measured in visceral organ biopsies. Application of this index to the control and AP groups showed a decrease in blood flow in all visceral organs of the AP group which was reflected by an increase in tissue hematocrit index (2.5-fold for kidneys, 2-fold for pancreas and lungs, 1.6-fold for liver, and 1.2-fold for spleen). 3. As expected, there was an increase in blood hematocrit and a decrease in plasma volume in the AP group, but there were no significant alterations in RBC volume. However, an unequal decrease in blood flow in various tissues such as kidneys, lungs, pancreas and liver was detected in the AP group. 4. This approach provides an easy and simple way to evaluate possible therapeutic protocols for the treatment of acute pancreatitis by measuring effects on visceral blood flow and plasma and blood volumes.

Acute Disease↗
PubMed1989

Protective effect of a protein-free diet in acute experimental pancreatitis.

1. Survival time, amylase activity and pancreatic protein, DNA and RNA content were measured in 38 control rats and in 104 rats injected with sodium taurocholate to induce acute pancreatitis after 21 days on one of four diets differing in protein, lipid and carbohydrate content. 2. All of the parameters measured were lower in rats with pancreatitis than in controls maintained on the same diets. Among the rats with pancreatitis, those receiving a protein-free diet survived longer and had significantly higher DNA, lower amylase activity and lower RNA and protein levels than those receiving a balanced diet or one that was high in protein or lipid content. 3. We conclude that acute pancreatitis in rats has a more benign course in protein-undernourished animals.

Acute Disease↗
PubMed1986

A modified technique for surgical repair of cicatricial stenosis of the bile duct.

A modified technique for the treatment of biliary tract strictures is presented. It features the longitudinal incision of the biliary duct above the stricture without any lateral or posterior duct dissection. The duct and the jejunum are brought together and a continuous posterior row of sutures is applied. Separated stitches are used for the anterior suture. No internal splints are used. Four patients have been operated upon with good results during a follow-up period of two years.

Cholestasis↗
PubMed1984

Acute pancreatic necrosis in chronic alcoholic pancreatitis.

Necrotic lesions are rarely observed in chronic pancreatitis, but its presence in a few patients has been misinterpreted in the diagnosis of acute pancreatitis. In this series, 12 patients (11.2%) of 107 operated for chronic alcoholic pancreatitis, presented with acute pancreatic necrosis associated with pancreatic fibrosis characteristic of chronic pancreatitis. Ten patients were treated by pancreatic debridement and drainage and two by distal pancreatic resections. Postoperative complications included five pancreatic fistulas and two pancreatic abscesses. Despite the severity of the pancreatic lesions which led to several complications, all the patients survived. The occurrence of pancreatic necrosis in patients with chronic pancreatitis is demonstrated.

Adult↗
PubMed1983

Ultrasonographic evaluation of ascaris in the biliary tract.

Ascaris in the biliary tract may cause cholecystitis and obstruction of the common bile ducts. Two cases are presented where worms that were identified in the common bile duct caused obstructive jaundice. The image of the ascaris is typical in its morphology and movement. Ultrasonography is useful in the identification of this parasite in the biliary tract where other conventional radiological methods are frequently unsatisfactory.

Adult↗