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Biomedical subjects

S G Meranze

Publications and source records attributed to S G Meranze.

At least 19 recordsLinked to original sources
PubMed2000

Synergistic effect of adrenal steroids and angiotensin II on plasminogen activator inhibitor-1 production.

Recent data suggest an interaction between the renin-angiotensin-aldosterone system and fibrinolysis. Although previous work has focused on the effect of angiotensin II (Ang II) on plasminogen activator inhibitor (PAI-1) expression, the present study tests the hypothesis that aldosterone contributes to the regulation of PAI-1 expression. To test this hypothesis in vitro, luciferase reporter constructs containing the human PAI-1 promoter were transfected into rat aortic smooth muscle cells. Exposure of the cells to 100 nmol/L Ang II resulted in a 3-fold increase in luciferase activity. Neither 1 micromol/L dexamethasone nor 1 micromol/L aldosterone alone increased PAI-1 expression. However, both dexamethasone and aldosterone enhanced the effect of Ang II in a dose-dependent manner. This effect was abolished by mutation in the region of a putative glucocorticoid-responsive element. A similar interactive effect of Ang II and aldosterone was observed in cultured human umbilical vein endothelial cells. The time course of the effect of aldosterone on Ang II-induced PAI-1 expression was consistent with a classical mineralocorticoid receptor mechanism, and the effect of aldosterone on PAI-1 synthesis was attenuated by spironolactone. To determine whether aldosterone affected PAI-1 expression in vivo, we measured local venous PAI-1 antigen concentrations in six patients with primary hyperaldosteronism undergoing selective adrenal vein sampling. PAI-1 antigen, but not tissue plasminogen activator antigen, concentrations were significantly higher in adrenal venous blood than in peripheral venous blood. Taken together, these data support the hypothesis that aldosterone modulates the effect of Ang II on PAI-1 expression in vitro and in vivo in humans.

Adrenal Cortex Hormones↗
PubMed1996

Positron emission tomography with F-18-fluorodeoxyglucose to evaluate the results of hepatic chemoembolization.

BACKGROUND: Positron emission tomography (PET) using F-18-flurodeoxyglucose (18FDG) is an imaging modality allowing direct evaluation of cellular glucose metabolism. The purpose of this study was to examine the role of 18FDG-PET in monitoring chemoembolization therapy of patients with liver metastases from adenocarcinoma. METHODS: Thirty-four hepatic lesions in 4 patients were evaluated with 18FDG-PET before and 2-3 months after interventional therapy. All patients underwent transcatheter arterial chemoembolization. A total of nine PET studies were performed. Semiquantitative measurement of the metabolic activity of the lesions was performed using the standard uptake value (SUV) of 18FDG. Comparison was performed between sequential PET scans using Student's t test for paired data analysis. The PET findings were also compared with tumor marker levels measured at the time of the PET scans. RESULTS: Twenty-five of 34 lesions had decreased 18FDG uptake (SUV = 8 +/- 2 vs. 3 +/- 1; P < 0.00001), as expected in successful tumor chemoembolization. These findings were associated with a significant decrease in serum tumor marker levels (86 +/- 4%; P < 0.05) after treatment. However, there were 3 new lesions, and 6 of the 34 lesions demonstrated persistent or increased 18FDG uptake after treatment (SUV = 8 +/- 2 vs. 13 +/- 3; P < 0.05), consistent with the presence of residual viable tumor. These findings led to further interventional therapy in all patients. CONCLUSIONS: 18FDG-PET allows monitoring of response to treatment with hepatic chemoembolization in patients with liver metastases from adenocarcinoma. PET is a useful diagnostic tool and has the potential to be used to guide further interventional therapy.

Adenocarcinoma↗
PubMed1994

Incidence of shunt occlusion or stenosis following transjugular intrahepatic portosystemic shunt placement.

BACKGROUND/AIMS: Transjugular intrahepatic portosystemic shunt (TIPS) placement has been used for the treatment of recurrent variceal hemorrhage. The 1-year incidence of shunt stenosis or occlusion after TIPS placement was prospectively assessed, and the accuracy of Doppler ultrasonography to predict TIPS stenosis was evaluated. METHODS: Twenty-two patients with recurrent variceal hemorrhage were selected for TIPS placement between April 1991 and May 1992. Preoperative and postoperative evaluation included clinical assessment, upper gastrointestinal endoscopy, portal angiography with pressure measurements, and Doppler ultrasonography. Follow-up was performed at 3 and 12 months post-TIPS and when patients developed recurrent bleeding. RESULTS: Twenty-one of 22 patients (Child-Pugh class A-1, B-11, C-9) had successful TIPS placement. Seventeen of 21 patients have completed follow-up for at least 12 months. Of these 17 patients, 2 of 17 (12%) developed TIPS occlusion, 7 of 17 (41%) developed shunt stenosis, and 8 of 17 (47%) showed no stenosis on follow-up angiography. Doppler ultrasonographic assessment of the TIPS predicted shunt stenosis or occlusion with 100% sensitivity, 98% specificity, and 90% positive predictive value. CONCLUSIONS: Shunt occlusion or stenosis develops frequently within 12 months after TIPS placement, and Doppler ultrasonography is accurate in the noninvasive assessment of shunt stenosis. TIPS placement without careful follow-up and shunt revision cannot be considered a long-term treatment of variceal hemorrhage.

Adult↗
PubMed1990

Percutaneous extraction of gallstones in 20 patients.

Percutaneous cholecystolithotomy (PCL) was accomplished successfully without general anesthesia in 17 of 20 consecutive symptomatic patients from an outpatient gallstone center who were at risk for or had refused cholecystectomy. The other three patients underwent cholecystectomy because of a gallbladder collapse before admission, a tight stone-bearing phrygian cap, and a cannula slippage, respectively. A subhepatic approach was preferentially used after the fundus of the gallbladder was stabilized with a percutaneous anchor to prevent invagination and bile leakage. Retrograde slippage of the anchor into the tract in the first six patients was remedied by elongating the anchor from 2 to 3 cm. Calculi were removed in one session (11 patients) or two consecutive sessions (six patients). Morbidity included rehospitalization for stitch infection (n = 1) and dehydration (n = 1), cannula slippage (n = 1), broken guide wire (n = 1), vasovagal reaction (n = 1), and unextractable anchors (n = 3). Gallbladder endoscopy enabled identification of stones not visible at cholecystography. Hospitalization lasted 3-5 days; outpatient gallbladder drains were removed in 2-3 weeks in 10 patients and 4-6 weeks in seven (older) patients. No retained stones were seen at 6 months. The authors recommend PCL for patients at risk for surgery.

Adult↗
PubMed1988

Interventional radiologic treatment of complications following gastric bypass surgery for morbid obesity.

Complications of gastric bypass surgery include leakage from the gastrojejunal anastomosis with abscess formation and anastomotic stenosis. Using interventional radiologic techniques, we have treated 18 patients with such complications following surgery for morbid obesity, with clinical success in 11. Procedures included 9 abdominal abscess drainages and 7 balloon dilatations of stenotic or occluded gastrojejunal anastomoses. Eight of 9 abscesses resolved completely; 3 of 7 balloon dilatations resulted in long-term clinical improvement. We describe the techniques used as well as problems encountered in these patients.

Abdomen↗
PubMed1988

Percutaneous drainage of abscesses in patients with Crohn's disease.

The hospital courses of 9 patients with intraabdominal abscesses and Crohn's disease who underwent abscess drainage utilizing percutaneous techniques were reviewed. Percutaneous methods brought about resolution of fever, leukocytosis, and the abscess cavity in 8 patients. In 5 of these, definitive cure was achieved with percutaneous drainage. In 3, single-stage bowel surgery and fistulectomy were performed following resolution of the abscess cavities and improvement of clinical signs and symptoms. All patients had uncomplicated postoperative courses. Percutaneous drainage should be the initial drainage procedure in treating postoperative abscesses, and, when performed preoperatively, can diminish surgical morbidity.

Abdomen↗
PubMed1988

Early removal of retained biliary stone without T-tube removal: case report.

Techniques for removal of retained common bile duct stones through mature tracts are safe and well established. When symptomatic, the stones may require removal prior to the 4-6 week period required for tract maturation. We report a case in which substituting a Teflon sheath for the standard polyethylene basket sheath allowed manipulation through the T-tube lumen and basketing of an impacted distal common bile duct stone, which had caused pancreatitis. This technique is simple and avoids the problem of loss of access to the biliary tree in the early postoperative period.

Aged↗
PubMed1988

Fibrolamellar hepatocellular carcinoma: pitfalls in nonoperative diagnosis.

Results from ultrasonography, computed tomography (CT), scintigraphy, hepatic angiography, and magnetic resonance (MR) imaging were analyzed for five patients with surgically proved fibrolamellar hepatocellular carcinoma (FL-HCC)--a variant of hepatocellular carcinoma (HCC) that usually occurs in younger patients and has an improved prognosis and chance for curative resection. The radiologic findings were generally inconclusive for a differential diagnosis because the appearance of the lesions on the various imaging studies closely simulated that of either focal nodular hyperplasia, HCC, or metastases. CT and technetium-99m sulfur colloid scintigraphy were the most effective techniques for the workup of these lesions, but because they do not allow a definitive diagnosis, open biopsy is recommended for most lesions simulating focal nodular hyperplasia and HCC in younger patients. Although the current specificity of MR imaging in diagnosing liver lesions is low, further experience may permit more specific characterization of these lesions.

Adult↗
PubMed1988

The midaortic syndrome: diagnosis and treatment.

The midaortic syndrome is an unusual entity seen in children and adolescents. It is characterized by severe narrowing of the abdominal aorta with progressive involvement of the renal and visceral branches. Eleven patients (aged 5 months to 15 years) suspected of having midaortic syndrome were examined preoperatively and postoperatively. All patients had hypertension and were examined with midstream aortography. All aortograms showed a smooth, segmental stenosis of the abdominal aorta and severe bilateral proximal renal artery stenosis. In three patients, percutaneous transluminal angioplasty of the renal artery was attempted, two preoperatively and one for a postoperative stricture. None showed long-term success, presumably due to the progressive nature of the disease. Grafts were surgically placed in ten patients and produced successful results in nine.

Angioplasty, Balloon↗
PubMed1988

Renal and related retroperitoneal abscesses: percutaneous drainage.

Renal and related retroperitoneal abscesses cause significant morbidity and mortality and almost always require drainage. The authors report 18 cases of percutaneous drainage of renal and related retroperitoneal abscesses, all of which were successfully managed. In 11 of these cases (61%), percutaneous drainage constituted the only treatment required. In the remaining seven (39%), the patients' clinical status improved after percutaneous drainage, and they were able to undergo subsequent elective nephrectomy with fewer complications. These results are comparable to those achieved with percutaneous abdominal abscess drainage and justify the use of percutaneous drainage for renal and related retroperitoneal abscesses as the therapeutic procedure of choice.

Abscess↗
PubMed1987

Embolization of a subclavian artery aneurysm with steel coils and thrombin.

Subclavian artery aneurysms are rare lesions usually treated by surgical excision or ligation. Steel coils were used successfully to treat a rapidly enlarging subclavian aneurysm in a patient deemed unsuitable for surgery. Because of a profound, uncorrectable coagulopathy, thrombin was required to obtain effective thrombosis.

Aged↗