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M C Machado

Publications and source records attributed to M C Machado.

At least 19 recordsLinked to original sources
PubMed2006

Metallothionein isoform 3 gene is differentially expressed in corticotropin-producing pituitary adenomas.

In order to search for candidate genes related to pituitary adenoma aggressiveness, the present investigation was intended to compare the mRNA expression profile from a pool of four nonfunctional pituitary adenomas (NFPA) with a spinal cord metastasis of a nonfunctional pituitary carcinoma (MNFPC). The metallothionein isoform 3 (MT3) gene was differentially expressed in nonfunctional adenomas in comparison to the metastasis of nonfunctional carcinoma. A microarray dataset comprising 19,881 probes was employed for comparing expression profiles of a spinal cord metastasis of a nonfunctional pituitary carcinoma with a pool of four nonfunctional pituitary adenomas. RT-qPCR confirmed the microarray findings and was used to investigate MT3 mRNA gene expression in tumor samples of a series of 52 different pituitary adenoma subtypes comprising 10 corticotropin (ACTH)-producing, 18 growth hormone (GH)-producing, 8 prolactin (PRL)-producing, and 16 nonfunctional adenomas. Microarray data analysis by GeneSifter program unveiled Gene Ontology terms related to zinc ion-binding activity closely related to MT3 function. MT3 mRNA expression was statistically significantly higher in ACTH-producing pituitary adenomas and in nonfunctional pituitary adenomas in comparison to the other pituitary adenoma subtypes. The more abundant expression of this gene in ACTH-producing pituitary adenomas suggests that MT3 could be related to distinct pituitary cell lineage regulating the activity of some transcription factor of importance in hormone production and/or secretion.

Adenoma↗
PubMed2004

Use of palivizumab to control an outbreak of syncytial respiratory virus in a neonatal intensive care unit.

To evaluate the safety and effectiveness of a humanized respiratory syncytial virus (RSV) monoclonal antibody (palivizumab) to control an outbreak of RSV in a neonatal intensive care unit (NICU), we retrospectively analysed two RSV outbreaks. Between 11 November 1998 and 18 March 1999, two separate RSV outbreaks occurred in a large (26 beds) NICU. All procedures for preventing nosocomial spread of RSV (including the use of palivizumab in the second outbreak) were retrospectively analysed. The cumulative incidence (CI), secondary attack rate (SAR) and risk ratio of infection were determined before and after the use of palivizumab for all patients and for those with gestational age below and above 32 weeks in the NICU during the second outbreak. Standard infection control measures were effective in the first outbreak (three cases). In the second outbreak, after three index cases, five additional infants were newly RSV-infected within one month. Three infants had RSV pneumonia and required mechanical ventilation; one infant died. Standard infection control procedures were initiated from the beginning of this outbreak. Palivizumab was given to all infants in the NICU after the fifth case was identified. CI was 2.4% in the first 15 days and 10.5% in the second, and SAR was 2.9 per thousand in the first 15 days and 14.1 per thousand in the second, both dropping to zero after the administration of palivizumab. The risk ratio of infection was 4.65 times higher in infants under 32 weeks gestational age. After the use of palivizumab, there were no additional identified cases. In addition to careful infection control procedures, the use of palivizumab might have contributed to arresting the outbreak of RSV infection in the NICU, suggesting that it could be an additional resource in the control of severe nosocomial RSV outbreaks.

Antibodies, Monoclonal↗
PubMed2001

Protective effect of metronidazole on uncoupling mitochondrial oxidative phosphorylation induced by NSAID: a new mechanism.

BACKGROUND: The pathogenesis of non-steroidal anti-inflammatory drug (NSAID) enteropathy is complex. It involves uncoupling of mitochondrial oxidative phosphorylation which alters the intercellular junction and increases intestinal permeability with consequent intestinal damage. Metronidazole diminishes the inflammation induced by indomethacin but the mechanisms remain speculative. A direct effect on luminal bacteria has traditionally been thought to account for the protective effect of metronidazole. However, a protective effect of metronidazole on mitochondrial oxidative phosphorylation has never been tested. AIMS: To assess the protective effect of metronidazole on mitochondrial uncoupling induced by indomethacin and also on the increased intestinal permeability and macroscopic damage. MATERIAL AND METHODS: The protective effect of metronidazole was evaluated in rats given indomethacin; a macroscopic score was devised to quantify intestinal lesions, and intestinal permeability was measured by means of (51)Cr-ethylenediaminetetraacetic acid. The protective effect of metronidazole against mitochondrial uncoupling induced by indomethacin was assessed using isolated coupled rat liver mitochondria obtained from rats pretreated with metronidazole or saline. RESULTS: Metronidazole significantly reduced the macroscopic intestinal damage and increase in intestinal permeability induced by indomethacin; furthermore, at the mitochondrial level, it significantly reduced the increase in oxygen consumption in state 4 induced by indomethacin and caused less reduction of the respiratory control rate. CONCLUSION: Our study confirmed the beneficial effects of metronidazole on intestinal damage and intestinal permeability, and demonstrated, for the first time, a direct protective effect of metronidazole on uncoupling of mitochondrial oxidative phosphorylation caused by NSAIDs.

Animals↗
PubMed2001

Multicentric pheochromocytoma and involvement of the inferior vena cava.

CONTEXT: Extension of pheochromocytomas to the inferior vena cava is rare. Multicentric tumors are rare as well, being present in up to 10% of cases. Surgery is the treatment of choice because of the long-term survival free of disease. DESIGN: Case report. CASE REPORT: We report on a case of right adrenal pheochromocytoma with extension to the supra-diaphragmatic vena cava, which underwent surgical excision through thoracophrenic laparotomy without the need for cardiopulmonary bypass. In a 6-year follow-up, another pheochromocytoma was found in the infra-renal Zuckerkandl's organ. Complete surgical excision of the tumor was performed by a median laparotomy and complete retroperitoneal dissection. In both cases, the total removal of the pheochromocytoma has been guaranteed by having margins free of tumor and a normal post-operative level of catecholamines. The pathological study revealed a malignant pheochromocytoma with margins free of neoplasia in both specimens.

Adrenal Gland Neoplasms↗
PubMed2000

Hepatic adenoma and focal nodular hyperplasia: differential diagnosis and treatment.

The diagnosis of benign hepatic tumors as hepatic adenoma (HA) and focal nodular hyperplasia (FNH) remains a challenge for clinicians and surgeons. The importance of differentiating between these lesions is based on the fact that HA must be surgically resected and FNH can be only observed. A series of 23 female patients with benign liver tumors (13 FNH, 10 HA) were evaluated, and a radiologic diagnostic algorithm was employed with the aim of establishing preoperative criteria for the differential diagnosis. All patients were submitted to surgical biopsy or hepatic resection to confirm the diagnosis. Based only on clinical and laboratory data, distinction was not possible. According to the investigative algorithm, the diagnosis was correct in 82.6% of the cases; but even with the development of imaging methods, which were used in combination, the differentiation was not possible in four patients. For FNH cases scintigraphy presented a sensitivity of 38.4% and specificity of 100%, whereas for HA the sensitivity reached 60% and specificity 85.7%. Magnetic resonance imaging, employed when scintigraphic findings were not typical, presented sensitivities of 71.4% and 80% and specificities of 100% and 100% for FNH and HA, respectively. Preoperative diagnosis of FNH was possible in 10 of 13 (76.9%) patients and was confirmed by histology in all of them. In one case, FNH was misdiagnosed as HA. The diagnosis of HA was possible in 9 of 10 (90%) adenoma cases. Surgical biopsy remains the best method for the differential diagnosis between HA and FNH and must be performed in all doubtful cases. Surgical resection is the treatment of choice for all patients with adenoma and can be performed safely. With the evolution of imaging methods it seems that the preoperative diagnosis of FNH may be considered reliable, thereby avoiding unnecessary surgical resection.

Adenoma↗
PubMed2000

Alternative technique of laparoscopic hepaticojejunostomy for advanced pancreatic head cancer.

Only 20% of patients with pancreatic cancer can undergo curative resection. Therefore, palliative treatment of pancreatic cancer assumes the utmost clinical importance. The aim of the palliative treatment of pancreatic head carcinoma is to relieve the jaundice and/or duodenal obstruction. Endoscopic or transparietal decompression of the obstructed bile duct can be accomplished in most cases, but the durability of these techniques is not as great as that of a surgically created bypass. On the other hand, hepaticojejunostomy carries higher morbidity and mortality rates than the former nonsurgical methods. In order to promote long lasting palliation with low morbidity and mortality rates, minimally invasive techniques of biliary and gastric bypass have been described. However, laparoscopic Roux-en-Y hepaticojejunostomy seems to be a complex surgical procedure. With an aim to simplify the construction of a laparoscopic hepaticojejunostomy, the authors suggest an alternative technique.

Female↗
PubMed2000

Preoperative diagnosis of pancreatic leiomyosarcoma.

BACKGROUND: The low incidence of pancreatic leiomyosarcoma is responsible for the small number of cases correctly diagnosed preoperatively, the tumor being frequently confused with benign pancreatic lesions. RESULTS: We describe a symptom free 52-yr-old male bearing an abdominal mass incidentally found at physical examination. Imaging techniques revealed a nonhomogenous large mass at the head of the pancreas that dislodged the portal vein and the superior mesenteric vein. Increased metabolic activity in the tumor area demonstrated by 18F-fluorodeoxyglicose positron emission tomography scan allowed the diagnosis of a malignant lesion. The patient was operated on and a pylorus preserving pancreatoduodenectomy performed. The pathology diagnosis was a low grade leiomyosarcoma. Immunohistochemistry revealed positivity for vimentin and smooth muscle specific actin. The clinical course was uneventful after 2 yr follow-up. CONCLUSION: Pancreatic leiomyosarcoma may be preoperatively diagnosed by image techniques and differentiated from benign lesions by means of fluorodeoxyglicose positron emission tomography scanning (FDGPET).

Actins↗
PubMed1999

Primary intrahepatic lithiasis: report of a case treated by laparoscopic bilioenteric anastomosis.

Recent advances in videolaparoscopic surgery have made this method the treatment of choice for many biliary diseases. However, it has not been used in certain cases, such as primary intrahepatic lithiasis. The authors report a case of a 62-year-old woman with a history of several episodes of cholangitis. Investigation revealed dilated intra- and extrahepatic bile ducts with intrahepatic stones. The patient underwent laparoscopy, and intraoperative cholangiography disclosed an enlarged common duct with absence of stones and the presence of multiple calculi in the intrahepatic biliary tree. A choledochotomy followed by choledochoscopy was performed, which revealed several intrahepatic pigmented stones that were completely retrieved, followed by a laterolateral choledochoduodenostomy to decompress the biliary tree and to allow the migration of residual or recurrent stones. The patient had an uneventful recovery and was discharged on the fourth postoperative day. After 15 months of follow-up the patient is asymptomatic with normal results of liver function tests. Late postoperative upper digestive endoscopy showed a patent choledochoduodenostomy.

Bile Ducts, Intrahepatic↗
PubMed1998

An alternative technique in the treatment of celiac axis stenosis diagnosed during pancreaticoduodenectomy.

Celiac compression is usually a benign condition, but when surgery necessitates division of collaterals from the superior mesenteric artery, it may cause life-threatening celiac organ ischemia. Celiac axis obstruction is found in 12.5% to 49.7% of patients during abdominal angiography. In such patients, the arterial blood supply to the stomach, spleen, and liver is sustained through extraordinarily well-developed pathways in the pancreas. Though collateral pathways may be sacrificed during pancreaticoduodenectomy, only a small proportion of patients develop hepatic, gastric and splenic ischemia during the procedure. If the appropriate angiographic studies have not been obtained before pancreatic resection, a test occlusion of the gastroduodenal artery, as recommended by Bull et al., should precede its ligation. The hepatic arteries are palpated before and after the test occlusion. In the occasional patient in whom the pulse diminishes during occlusion or if there is evidence of upper abdominal visceral ischemia, revascularization of the celiac circulation may be required. Reestablishment of the celiac circulation may be accomplished by the use of a vein graft between the aorta and the celiac tributaries. This article describes an alternative technique for revascularization of the celiac circulation without the use of a venous graft.

Anastomosis, Surgical↗
PubMed1997

Hepatic damage during acute pancreatitis in the rat.

We studied the alterations in the metabolism of liver mitochondria in rats with acute pancreatitis. Male Wistar rats were allocated to a control group (group I) and to five other groups corresponding to 2, 4, 12, 24 and 48 h after the induction of acute pancreatitis by the injection of 5% sodium taurocholate into the pancreatic duct. Sham-operated animals were submitted to the same surgical steps except for the induction of acute pancreatitis. Mitochondrial oxidation and phosphorylation were measured polarographically by determining oxygen consumption without ADP (basal respiration, state 4) and in the presence of ADP (activated respiration, state 3). Serum amylase, transaminases (ALT and AST) and protein were also determined. Ascitic fluid, contents of amylase, trypsin and total protein were also determined and arterial blood pressure was measured in all groups. In ascitic fluid, trypsin and amylase increased reaching a maximum at 2 and 4 h, respectively. Serum amylase increased at 2 h reaching a maximum at 4 h. Serum transaminase levels increased at 12 and 24 h. After 2 h (and also 4 h) there was an increase in state 4 respiration (45.65 +/- 1.79 vs 28.96 +/- 1.50) and a decrease in respiration control rate (3.53 +/- 0.09 vs 4.45 +/- 0.08) and in the ADP/O ratio (1.77 +/- 0.02 vs 1.91 +/- 0.01) compared to controls (P < 0.05). These results indicate a disruption of mitochondrial function, which recovered after 12 h. In the 48-h groups there was mitochondrial damage similar to that occurring in ischemic lesion. Beat-to-beat analysis (30 min) showed that arterial blood pressure remained normal up to 24 h (111 +/- 3 mmHg) while a significant decrease occurred in the 48-h group (91 +/- 4 mmHg). These data suggest biphasic damage in mitochondrial function in acute pancreatitis: an initial uncoupled phase, possibly secondary to enzyme activity, followed by a temporary recovery and then a late and final dysfunction, associated with arterial hypotension, possibly related to ischemic damage.

Animals↗
PubMed1995

Splenic abscess.

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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↗