Preoperative assessment of blood vessel involvement in patients with pancreatic cancer

The major prerequisite for resection of a pancreatic tumor is non-involvement of large blood vessels. Preoperative assessment of blood vessel infiltration may prevent unnecessary surgery. The aim of our study was to investigate the accuracy of endoscopic ultrasonography (EUS) in diagnosis of pancreatic cancer and in preoperative staging. Thirteen patients (7 females, 6 males; mean age 64 years) with a pancreatic tumor, but no evidence of distant metastases, underwent EUS and computerized tomography (CT) in order to assess blood vessel involvement by the tumor. The results were compared with intraoperative findings in 12 patients and with postmortem findings in 1 patient. A tumor was demonstrated by EUS in 12 patients and was confirmed at surgery in all 12 patients. In one patient no tumor was demonstrated by EUS, although a tumor was visible by CT; no tumor was found at surgery. In two patients CT failed to demonstrate a pancreatic tumor that was demonstrated by EUS; at surgery a tumor was detected in both patients. EUS detected blood vessel involvement in seven patients, which was confirmed at surgery in six of them. In the other six patients surgery confirmed the EUS finding of no blood vessel involvement. CT detected blood vessel involvement in two patients only. The overall accuracy of EUS and CT for detecting the tumor was 100% and 77% respectively, and for blood vessel involvement 92% and 61% respectively. In conclusion, EUS is an accurate procedure for preoperative assessment of blood vessel involvement in patients with pancreatic cancer. This procedure may enable the selection of those patients who may benefit from surgery, and should be part of the evaluation of patients with pancreatic cancer who are candidates for curative surgery.

Pulmonary function abnormalities in type I Gaucher disease

The purpose of this study was to determine the prevalence of pulmonary function and radiographic abnormalities among patients with type I Gaucher's disease, and to analyse the relationship between the pulmonary involvement and genotype and clinical severity score. All patients attending the Gaucher clinic at the Shaare Zedek Medical Center, Jerusalem, Israel, during the years 1992-1993 were prospectively evaluated. Each patient had pulmonary function tests, chest radiography, clinical assessment in terms of degree of organ involvement, and genotype analysis. Of the 95 patients included in the study (mean +/- SD age 29 +/- 15 yrs), 68% had some pulmonary function abnormalities, most commonly a reduced FRC and transfer coefficient for carbon monoxide (Kco), found in 45% and in 42% of the patients respectively. Total lung capacity (TLC) was reduced in 22% of the patients and forced expiratory flows in approximately one third of the patients. Signs of airtrapping (elevated residual volume (RV) or RV/TLC) were seen in 18% of the patients. Males had a higher incidence of reduced expiratory flow than females, (forced expiratory volume in one second (FEV1) was reduced in 36% of males vs 5% of females). Chest radiographic abnormalities were found in 17% of the patients, although only 4% had severe changes. Patients with abnormal pulmonary function had a significantly higher severity score index than those with normal pulmonary function tests. There was no association between abnormal pulmonary function and genotype or age. In conclusion, abnormal pulmonary function is common among type I Gaucher patients. Pulmonary function tests show airways obstruction, with reduced expiratory flows, reduction in lung volumes and alveolar-capillary diffusion abnormality. The rate of progression and the clinical significance need to be determined.

Omeprazole has no effect on acetaminophen kinetics in the rat

We investigated in the rat the effect of the H+/H(+)-ATPase inhibitor, omeprazole, on the kinetics of acetaminophen. Two groups of rats were treated with either omeprazole 50 mg/kg/day or the vehicle for 7 days. On day seven, the pharmacokinetic parameters of acetaminophen clearance were determined in the conscious rat. Elimination rate constant, elimination half life time, clearance and volume of distribution of acetaminophen were not disturbed by omeprazole. It is concluded that in the rat, omeprazole does not affect acetaminophen kinetics and, therefore, will not increase susceptibility to acetaminophen toxicity.

Accuracy of endoscopic ultrasonography for preoperative staging of esophageal malignancy

Surgery for esophageal cancer carries a high mortality rate and a low rate of resectability for cure. Accurate preoperative staging is therefore of utmost importance. Staging is based on computerized tomography (CT), and recently, the use of endoscopic ultrasonography (EUS). We performed EUS and CT on 10 patients with esophageal cancer. Tumors were staged according to the TNM classification. According to the CT results, seven patients had a T3 tumor, one T1-2 and two T0. All patients were diagnosed as T3 by EUS. One patient, who was treated by combined modality treatment with chemotherapy and radiotherapy, converted to T0. Six patients were operated on, and in five, pathological findings were of an invasive tumor. The T stage was predicted correctly in five patients by CT and in all six patients by EUS. N stage was correctly diagnosed in two patients by CT and in five by EUS. It is concluded that EUS is superior to CT for preoperative staging of esophageal tumors. EUS should be undertaken as a routine procedure prior to surgery for esophageal cancer.

Famotidine has no effect on cardiac performance and liver blood flow in the rat

Conflicting results have been reported on the effect of famotidine on cardiac performance and visceral hemodynamics, studied by non-invasive techniques. It is for that reason that we used the radioactive microsphere technique to study the effect of famotidine on cardiac performance in the rat. Hepatic blood flow (HBF) and portal blood flow (PBF) were measured during the same experiment. Rats were either given famotidine (2.0 mg/kg per day) or drinking water for 7 days through an orogastric tube. Administration of famotidine had no effect on cardiac output (CO), HBF, PBF, or liver blood flow (LBF), which is the sum of HBF and PBF. In both groups, LBF consisted of a similar fraction of CO, 14.5 +/- 3.9% and 15.7 +/- 4.38%, in the control and the famotidine groups, respectively. Pulse rate, systolic pressure and left ventricular contractility were not affected by famotidine. It is concluded that in the rat, administration of famotidine for 7 days has no effect on systemic, hepatic or portal hemodynamics.

A multicenter, double-blind, randomized controlled study of omeprazole versus ranitidine in the treatment of duodenal ulcer in Israel

A multicenter, double-blind, randomized, controlled study of 203 Israeli patients with endoscopically proven duodenal ulcer is described. The study compares the efficacy (i.e., ulcer healing and relief of symptoms) and safety of 20 mg omeprazole once daily in the morning, with those of 300 mg ranitidine once daily at night. The omeprazole group had significantly higher cumulative healing rates than the ranitidine group both at day 15 (71% vs. 55%, P < 0.03) and day 29 (94% vs. 86%, P < 0.05). The efficacy was unaffected by known risk factors such as smoking. The omeprazole group had significantly fewer days with pain than the ranitidine group (median 1 vs. 3.5 days) (P < 0.03). There were no differences in ulcer size, symptoms or healing rates between Ashkenazi and Sephardic patients who were born in Israel, or who had immigrated to Israel. In summary, the present study confirms the efficacy and safety of omeprazole in the treatment of duodenal ulcer. Omeprazole provides more rapid relief of the symptoms and heals a greater proportion of duodenal ulcers, within 2-4 weeks, than ranitidine.

Vanadate has no effect on insulin-extraction by the rat liver

The mechanism(s) responsible for the insulin-like effects of vanadate are still unclear, although several possible explanations have been raised. However, the possibility that vanadate induces inhibition of insulin degradation in the liver was not examined yet. Therefore, in the present study we examined the effect of vanadate on the extraction of insulin by the perfused rat liver using an open, non-recycling system. Baseline insulin extraction (44 +/- 2% and 37 +/- 3%) was not affected by the administration of 1 and 5 microM vanadate (decreased to 42 +/- 2% and 36 +/- 1, respectively, p = NS). Vanadate had no adverse effects on liver viability, and the bile flow remained stable during and after vanadate administration (0.87 +/- 0.08 microliter/min/g liver prior to Vs. 0.084 +/- 0.11 microliter/min/g liver following vanadate administration). This study shows that vanadate does not inhibit insulin extraction by the perfused liver, and that does of vanadate that effectively inhibit hepatic glucose production possess no adverse effects on liver viability.

Alpha interferon has no effect on lidocaine metabolism in the rat

Interferons (IFN) inhibit activity of many isoenzymes of the hepatic microsomal cytochrome P-450 system. This inhibition is species specific. Lidocaine is metabolized by cytochrome P-450 III A 4. We investigated in the rat the effect of rat alpha-IFN on lidocaine elimination and on its extraction by the isolated perfused rat liver. To determine elimination, the femoral artery and vein were cannulated. 24 h later, the conscious rat was given lidocaine through the venous catheter and blood was drawn from the arterial catheter for lidocaine determination every 3 min for 20 min. 7 rats were pre-treated with intramuscular rat alpha-IFN 7.5 x 10(5) U, 24 h prior to the experiment and another 4 rats were given saline i.m. The lidocaine elimination rate constant was unchanged, 0.065 min-1 and 0.063 min-1 for the control and IFN groups, respectively. To investigate lidocaine extraction, the isolated perfused rat liver was used. Perfusate samples from the portal and hepatic veins were drawn at 2 min intervals for 20 min, and lidocaine extraction determined. Extraction was determined in two groups of 6 rats each. The first group served as control and these rats were injected with saline only, while in the second group, the rats were pre-treated with rat alpha-IFN 7.5 x 10(5) U. Lidocaine extraction by the isolated perfused rat liver remained unchanged, 97.0 +/- 0.7% and 94.0 +/- 2.4% in the control and IFN treated groups, respectively. It is concluded that the rat alpha-IFN affects neither the elimination nor the extraction of lidocaine.

Complications of rubber band ligation of symptomatic internal hemorrhoids

In a prospective study, 512 patients undergoing hemorrhoidal band ligation over a seven-year period were followed up to focus on complications. Thirteen patients (2.5 percent) were hospitalized: six with delayed massive rectal bleeding, three with urinary retention, pain, and fever (one developed perianal abscess), and three others with severe pain due to prolapsed thrombotic hemorrhoids (one developed difficulty in urination). One patient developed perianal abscess and perianal fistula two months after ligation. Twenty-four patients (4.6 percent) suffered from minor complications: 11 patients had painful thrombosed hemorrhoids; five experienced slippage of bands; three had mild bleeding; two developed band-related mucosal ulcer; one experienced each time, after two subsequent ligations, priapism lasting several hours; and difficulty in urination and tender induration above the dentate line occurred in two other patients. Rubber band ligation is, in effect, a miniature hemorrhoidectomy and has been considered, until recent reports of fatalities associated with this procedure, as an effective, safe, and efficient method of treating symptomatic second-degree and third-degree hemorrhoids. We conclude that the ability to handle complications that occur secondary to the rubber band ligation and, thereby, prevent sepsis and the low rate of major complications in our study justify reliance on this method of treating symptomatic hemorrhoids.

Recovery of pressor response to norepinephrine following relief of the obstructed common bile duct in the rat

Jaundice caused by common bile duct (CBD) obstruction is associated with a blunted pressor response to norepinephrine (NE). We studied the rate and extent of recovery of the pressor response in the rat following relief of the obstruction. Three groups of male Wistar rats underwent CBD ligation. In the first and second group blood pressure measurements were obtained at 72 and 144 h after CBD ligation, respectively. In the third group pressure measurements were recorded 72 h after the relief of a 72-h obstruction. A fourth group served as control, and measurements were obtained 72 h after a sham operation. In all four groups measurements included basal blood pressure and pressure change following escalating doses of NE, ranging from 0.5 to 10 micrograms/kg. Basal blood pressure was similar in all four groups. In the control group the change of blood pressure was 23.4% +/- 6.7% in response to the lowest dose of NE, and 83.5% +/- 24.9% in response to the highest dose. A blunted pressor response to NE was recorded in all three groups with CBD obstruction. The duration of CBD ligation (72 or 144 h) did not affect this blunded response. Re-establishment of bile flow for 72 h made only a slight improvement in the response to NE. Obstruction of the CBD was associated with hyperbilirubinemia which disappeared following the re-anastomosis of the CBD to the duodenum. This most significant decrease in serum bilirubin was not associated with a similar improvement in pressor response to NE. We conclude that in the rat CBD obstruction is associated with a blunted pressor response to NE, that relief of CBD obstruction for 72 h is insufficient to abolish this response, and that there is no full correlation between serum bilirubin and pressor response.

Recovery of hepatic clearance and extraction following a release of common bile duct obstruction in the rat

The rate of recovery for hepatic clearance and extraction following release of common-duct obstruction was investigated in the rat. Male Wistar rats underwent ligation of a cannulated common bile duct. Two weeks later, the cannula was opened and implanted into the duodenum, thus re-establishing enterohepatic circulation. Hepatic extraction and indocyanine green clearance were determined in three groups of six rats each, which differed by the time elapsed from the re-establishment of communication between the common bile duct and duodenum, i.e., 1, 48 and 168 h, respectively. A fourth group, in which a sham operation was performed, served as a control. Clearance was reduced from 16.9 +/- 2.5 ml/min per kg in the control group to 2.9 +/- 0.8, 5.4 +/- 2.4, and 8.5 +/- 3.3 ml/min per kg 1, 48, and 168 h, respectively, after release of common-bile-duct obstruction. Extraction rate was reduced from 37.3 +/- 5.9% to 17.5 +/- 2.7% in the 1st hour and recovered completely at 1 week. Thus, in the rat, release of a 2-week common-bile-duct obstruction is associated with complete recovery of the extraction capacity of the liver within a week, but only incomplete recovery of clearance. This decrease in clearance seems to be due to a decrease in effective hepatic blood flow, mostly probably due to the development of porto-systemic shunts.

Aspartic-acid synthesis in C3 plants

In a previous study (Melzer and O'Leary, 1987, Plant Physiol. 84, 58-60), we used isotopic methods to show that a substantial fraction of protein-bound aspartic acid in tobacco is derived from anaplerotic synthesis via phosphoenolpyruvate (PEP) carboxylase. Similar studies in soybean (Glycine max L.) and spinach (Spinacia oleracea L.) showed a similar pattern, and this pattern persists with age because of slow protein turnover. A more quantitative analysis indicates that about 40% of protein-bound aspartate is derived in this manner. Analyses of free aspartic and malic acids show that contribution of PEP carboxylase to the synthesis of these acids decreases with increasing age. The C4 plant Zea mays L. did not show this pattern.

Double-blind controlled trial of flumazenil in patients who underwent upper gastrointestinal endoscopy

The antisedative effect of flumazenil, a benzodiazepine antagonist, was studied in a double-blind placebo controlled trial in 61 patients who underwent upper gastrointestinal endoscopy and sedation with benzodiazepines. The efficacy of flumazenil in reversing the effect of both benzodiazepines, diazepam and midazolam, was significantly higher than placebo (p less than 0.0001). The effect of flumazenil was prompt and was clearly noticed at the first assessment, 5 min after its administration. In none of the patients was a relapse of the sedative effect of the benzodiazepines noticed. The administration of flumazenil was free of major side effects. Flumazenil administration permits an earlier discharge of patients following endoscopy. Its availability in the endoscopy suite may improve the outcome of serious but rare side effects related to benzodiazepines.

Oxygen isotope effects on the ribulosebisphosphate oxygenase reaction

The oxygen isotope effect at the substrate O2 on the oxygenase reaction of ribulose bisphosphate carboxylase/oxygenase from spinach is pH and metal dependent. The pH dependence between pH 7.4 and 8.9 is different with Mg2+ (steady decrease in this isotope effect from 1.036 to 1.030) and Mn2+ (minimum isotope effect of 1.028 at pH 8.0). Deuteration of the substrate ([3-2H]ribulose bisphosphate) has no influence on the isotope effect. The results are interpreted as a direct participation of the metal ion in the oxygen-sensitive step, i.e. carbon-oxygen bond formation and the stabilization of the intermediates. In the overall reaction oxygen addition is a major rate-limiting step, and the observed isotope effect is probably close to the intrinsic oxygen isotope effect of the reaction. The basic mechanisms for carboxylation and oxygenation of ribulose bisphosphate appear to be the same.

The effect of PGE2 on hepatic blood flow and bile indocyanin green in the rat

The effect of Prostaglandin E2 (PGE2) on hepatic blood flow and bile excretion has been only partially investigated. We studied in the rat the effect of PGE2 on indocyanine green (ICG) clearance, bile flow and ICG recovery in the bile. PGE2 administered to rats at a rate of 2 micrograms/kg/min had no effect on ICG clearance as compared to vehicle-treated rats (14.6 +/- 2.5 Vs, 16.9 +/- 2.5 ml/min/kg) and on bile flow (1.23 +/- 0.15 Vs. 1.24 +/- 0.11 microliters/min/gm liver). However, ICG excretion in bile was significantly increased as compared to a vehicle-treated group, 0.48 +/- 0.09 and 0.25 +/- 0.02 micrograms/microliters bile, respectively (P less than 0.005). This effect of PGE2 on ICG recovery in bile was found to be dose-dependent, and when PGE2 was administered at a rate of 1 microgram/kg/min, bile ICG decreased to 0.33 +/- 0.10 microgram/microliter bile. The effect of PGE2 on bile ICG is not due to an increased extraction of ICG by the liver since using the isolated perfused rat liver, the mean ICG extraction rate over a 20 minute period, with and without PGE2 infusion, was very similar, 33 +/- 3.5 and 37 +/- 6.2 percent, respectively. The lack of effect of PGE2 on ICG clearance and extraction and on bile flow, with an increase in biliary excretion of ICG, suggests a decreased hepatic storage of ICG induced by PGE2 possibly due to an accelerated rate of ICG excretion from the hepatocytes to the bile canaliculi.

Carbon isotope effects on the decarboxylation of carboxylic acids. Comparison of the lactate oxidase reaction and the degradation of pyruvate by H2O2

The isotope effect at C-1 on the H2O2-catalysed decarboxylation of pyruvate (used as a model reaction for the enzymic reaction) increases between pH 3 and 10 from 1.0007 +/- 0.0004 to 1.0283 +/- 0.0014 (25 degrees C). This result indicates a change in the rate-determining step from formation of the tetrahedral intermediate to decarboxylation of this intermediate. Practically no isotope fractionation at C-1 (1.0011 +/- 0.0002, pH 6.0, 25 degrees C) is found in the lactate oxidase-catalysed decarboxylation of lactate, which is indicative for the existence of an irreversible O2-dependent step prior to the enzyme-catalysed decarboxylation. In addition, the result provides further evidence that dissociation of pyruvate and H2O2 from the enzyme can be excluded. The isotope effect at C-2 of lactate in the enzymic reaction (1.0048 +/- 0.0004) is attributed to the hydrogen transfer step from lactate to the coenzyme.

Pulmonary manifestations of temporal arteritis

Temporal arteritis is a well-recognized multi-systemic disease. Pulmonary manifestations, however, are extremely rare. In two patients with biopsy-proven temporal arteritis, lung involvement was observed. One patient presented with multinodular pulmonary lesions, while the second had a diffuse interstitial pattern. Both patients responded well to corticosteroid treatment. In a review of the literature, only four additional cases associating lung involvement with temporal arteritis were found. The possibility of primary pulmonary vasculitis should be considered in elderly patients with temporal arteritis.