Endoscopic management of malignant biliary obstruction by means of covered metallic stents: primary stent placement vs. re-intervention.

BACKGROUND AND STUDY AIMS: Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Occlusion of covered metallic stents now occurs in about half of all patients with malignant biliary strictures. The removal of metallic stents followed by placement of a second stent has been attempted, but outcomes remain controversial. The aim of the current study was to evaluate the effectiveness and safety of the primary placement and secondary placement (re-intervention) of covered metallic stents and to assess the feasibility and safety of stent removal. PATIENTS AND METHODS: The study included 186 patients with unresectable malignant biliary strictures who underwent primary stent placement between October 2001 and March 2010.  Covered biliary self-expandable metal stents (SEMSs) were removed in 39 of these patients, and 36 underwent re-intervention. The patency times, occlusion rates of the first stent and re-intervention, success rates of stent removal, and complications were investigated. RESULTS: Covered SEMSs were placed in 186 patients. The median patency time of the first stent was 352 days. Stent occlusion occurred in 48.9 % of the patients and was mainly caused by debris or food residue (37 %), dislocation (19 %), and migration with hyperplasia (19 %). Stent removal was attempted in 50 patients and was successful without complication in 39 (78 %). Most of the patients in whom stent removal was unsuccessful had migration with hyperplasia. The median patency time of the second stent was 263 days. The stent patency time did not significantly differ between the first and the second stent. CONCLUSIONS: Covered SEMSs could be safely removed at the time of stent occlusion. Patency rates were similar for initial stent placement and re-intervention.

Near-infrared spectroscopy in carotid artery stenting predicts cerebral hyperperfusion syndrome.

OBJECTIVE: Cerebral hyperperfusion syndrome (CHS) following carotid artery stenting (CAS) or carotid endarterectomy (CEA) is rare but often fatal once intracranial hemorrhage has occurred. In particular, CHS occurs significantly earlier after CAS than after CEA. Thus a monitoring method for early detection of CHS is required. Near-infrared spectroscopy (NIRS) provides a noninvasive monitoring technique for assessing regional cerebral oxygen saturation (rSO2). This study evaluated the usefulness of transcranial NIRS during CAS for prediction of CHS. METHODS: Periprocedural rSO2 was monitored in 64 cases of CAS (52 men, 12 women; 71 +/- 6.6 years). The average degree of carotid stenosis was 76.8 +/- 11.3% by North American Symptomatic Carotid Endarterectomy Trial criteria. Bifrontal rSO2 was monitored during the procedure using NIRS. Seventeen patients were symptomatic and 47 were asymptomatic. CHS was diagnosed by increased cerebral blood flow by SPECT performed on the day after treatment with deterioration of neurologic symptoms. RESULTS: CHS was observed in two cases (3.1%). In the CHS group, post-reperfusion rSO2 values increased >24% from baseline until 3 minutes after reperfusion. In the non-CHS group, the normal upper limit (NUL) of the rSO2 change was set at 10.0% at 3 minutes after reperfusion. In the CHS group, rSO2 at 3 minutes after reperfusion was markedly higher than the NUL. In patients showing an rSO2 at 3 minutes after reperfusion increased by more than 10.0%, CHS following CAS could be predicted. CONCLUSION: Periprocedural increases in regional cerebral oxygen saturation measured by near- infrared spectroscopy can be an excellent predictor of cerebral hyperperfusion syndrome after carotid artery stenting.

Influence of endoscopic papillary balloon dilation and endoscopic sphincterotomy on sphincter of oddi function: a randomized controlled trial.

BACKGROUND AND STUDY AIM: Endoscopic papillary balloon dilation (EPBD) is assumed to have a theoretical advantage over endoscopic sphincterotomy (EST) in preserving sphincter of Oddi function because it does not involve cutting the biliary sphincter. Although attempts have been made to study the influence of EPBD and EST on sphincter of Oddi function, there is little agreement on this issue. In this study we used a method different from those described in previous reports to clarify whether EPBD or EST preserves sphincter of Oddi function better. PATIENTS AND METHODS: 200 patients with bile duct stones who met the eligibility criteria were randomly assigned to EPBD (n = 104) or an EST (n = 96) group. Sphincter of Oddi function was estimated by measurement of the activity of pancreatic enzymes in the common bile duct (CBD). Pure bile was collected immediately before EPBD or EST, at 1 week and at 1 year after the procedure. We also statistically investigated 14 factors other than EPBD or EST that might have the potential to affect sphincter of Oddi function. RESULTS: There was no significant difference between the baseline characteristics of the EPBD and EST groups. A total of 91 patients (46 in the EPBD group and 45 in the EST group) remained in the trial. Pure bile was collected from the CBD of 86 patients (43 EPBD and 43 EST) 1 week after the procedure. CBD stones were extracted successfully in all cases. Before the procedure, there were no significant differences in the levels of the five pancreatic enzymes between the EPBD and EST groups. At 1 week after the procedure, in both groups, there were significant increases in the levels of the five pancreatic enzymes. At 1 year after the procedure a complete series of pancreatic enzyme analyses was done in 33 patients (12 EPBD and 21 EST). There was no significant difference between the levels of the five pancreatic enzymes immediately before and 1 year after EPBD and EST. When the pancreatic enzyme levels of the two groups were directly compared, there was no significant difference at 1 year after the procedure, but the EPBD group had significantly higher levels at 1 week following the procedure. CONCLUSION: In this study it was found that in patients with CBD stones both EPBD and EST preserve sphincter of Oddi function.

An assay method for nitric oxide-related compounds in whole blood.

Recent evidence suggests that nitric oxide (NO) generated in vivo will be converted into the forms of nitrite/nitrate, nitrosyl hemoproteins, nitrosyl metal complexes, and S-nitroso-compounds in the circulation. Nitrosothiols have also been reported to be relatively stable metabolites with micromolar levels in plasma. We hypothesized, therefore, that the determinations of all the NO-related compounds in blood would be of diagnostic significance. The assay method described here consists of the thermolysis of all the NO-related compounds in whole blood and the detection of resulting nitrate by fluorometry or chemiluminescence after an enzymatic reduction. S-Nitroso-albumin and nitrosyl hemoglobin can be easily thermolysed to nitrate, and relatively stable S-nitroso-glutathione is also degraded to nitrate in the presence of blood constituents with high molecular mass (above 30 kDa). Concentrations of NO-related compounds in blood from healthy human as well as control or lipopolysaccharide-stimulated rats were determined. We found that membrane-bound NO which showed the augmented levels under the pathophysiological states could also be detected. Together with electron spin resonance spectra, our data indicate that the fraction of NO diffused and metabolized within red cells and the other NO-metabolites in plasma such as nitrite/nitrate and S-nitroso-compounds, both of which can reflect NO-production in vivo, would be recovered and detected quantitatively by this method.

Thyroid hormone-free albumin: charcoal treatment or resin treatment.

Free thyroid hormone measurement by means of immunoassay kits is greatly influenced by the altered serum albumin and free fatty acid (FFA) levels. In the evaluation of these kits, it is therefore essential to study the interferences due to these factors by adding FFA or thyroid hormone-free human serum albumin (HSA) to the assay mixture, but little attention has been paid to the selection of albumin. In the present study, FFA content in various preparations of thyroid hormone-free HSA was compared. Charcoal-treated HSA was free from both thyroid hormone and FFA, whereas anion exchange resin-treated HSA was only free from thyroid hormone. Commercially available "FFA-free HSA" was also free from thyroid hormone. Our results suggest that attention must be paid to the nature of albumin when studying the interference by albumin in free thyroid hormone measurement and that commercially available "FFA-free HSA" is a ready-to-use thyroid hormone-free HSA when HSA free from both FFA and thyroid hormone is desired.

Recognition and neural plasticity responding to deficient nutrient intake scanned by a functional MRI in the brain of rats with L-lysine deficiency.

Each L-amino acid (AA) in plasma and brain remains unchanged while normal diet is available. Once L-lysine (Lys) deficient diet was offered to rats, Lys in plasma and brain declined, and anorexia occurred. When solutions of AAs were offered, they selected the Lys solution, and their food intake and growth normalized. The single neuron activity in the lateral hypothalamic area of these rats suggested that neural plasticity occurred, specifically responding to Lys, both by iontophoretic application and during ingestion of AA. The recognition site for deficient nutrient intake in the brain of rats with Lys deficiency was identified by non-invasive magnetic resonance imaging (MRI 4.7 tesla, 40 cm bore in diameter) developed to monitor changes in cerebral blood flow and oxygenation in rat brain. Wistar strain young male rats fed with Lys deficient diet for 4 days, were adapted to be settled in the center of the bore. When they received a Lys injection intraperitoneally (0.2 M, 10 mL/kg), a signal intensity decrease in the medial and lateral hypothalamus appeared 30 minutes later in T2 weighted images, reflecting increased oxygenation which lasted for 30 minutes, and then gradually recovered. These changes never occurred in any other areas of the brain of rats with Lys deficiency, i.e., the thalamus, the cortex, the hippocampus, etc. There were no changes in the signal intensity with control injection of saline. In addition, oxygen consumption in the brain of rats without Lys deficiency was not altered by intraperitoneal Lys injection. The present results suggest that in essential AA deficiency, the medial and lateral hypothalamus may play important roles in recognition responses to particular deficient nutrients in order to maintain homeostasis.

Value of thallium-201 early reinjection for assessment of myocardial viability.

To assess the efficacy of early reinjection for predicting post intervention improvement in thallium-201 (T1) uptake and regional wall motion, we reinjected a small dose of T1 following post-stress imaging and obtained reinjection early images (10 min after early reinjection) and reinjection delayed images (3 hr afterwards) in 40 patients who were referred to us for revascularization (group I). Twenty-nine patients in group I also underwent conventional stress-redistribution T1 scintigraphy (group II). Conventional stress-redistribution T1 scintigraphy was repeated after intervention. Contrast left ventriculography was performed before and after intervention and changes in regional wall motion were assessed in 22 of 40 patients. In group I, the predictive value for improvement and no improvement (the accuracy) of reinjection early images in perfusion was 83%, while that of reinjection delayed images was 91%. Furthermore, the accuracy of reinjection early images in regional wall motion was 80%, while it was 91% for reinjection delayed images. In group II, the accuracy in perfusion was 78% and the value in regional wall motion was 70%. Both accuracy in perfusion and in regional wall motion obtained from reinjection delayed images were significantly higher than the values in group II (p < 0.05). These data suggest that early reinjection is useful for predicting postintervention thallium uptake and regional wall motion.

Circulating myosin light chain I levels after coronary reperfusion: a comparison with myocardial necrosis evaluated from single photon emission computed tomography with pyrophosphate.

This study was performed to assess the influence of coronary reperfusion on the serial serum myosin light chain (LC)I levels and to evaluate the relationship between the peak LCI level and the infarct size calculated from single photon emission computed tomography (SPECT) with technetium-99m pyrophosphate (Tc-99m PYP) in 11 patients who underwent coronary reperfusion. Blood was drawn before reperfusion, immediately after reperfusion, and once a day for 14 days, to estimate the time course of serum LCI release. The infarct size estimated by Tc-99m PYP ranged from 7.3 to 62.4 ml. The LCI levels obtained before reperfusion were less than 2.5 ng/ml but those obtained immediately after reperfusion were much higher. The value ranged from 2.7 to 9.7 ng/ml and that expressed as a percentage of peak LCI (% peak LCI) ranged from 19 to 83%. Collateral circulation, reperfusion arrhythmia and the degree of residual stenosis had no influence upon the % peak LCI. The correlation between peak LCI levels and SPECT-determined infarct size was good, with a correlation of 0.76 (p less than 0.01, regression line by least squares method y = 3.31 + 1.53x). Early serum LCI might be influenced by coronary reperfusion but the peak LCI value reflected acute myocardial necrosis in patients who underwent coronary reperfusion.

[Scintigraphic quantification of myocardial necrosis using "hot spot" imaging agents in acute myocardial infarction].

Both technetium-99m pyrophosphate/thallium-201 dual nuclide SPECT and indium-111 antimyosin antibody/thallium-201 dual nuclide SPECT were performed in identical 11 patients with acute myocardial infarction. Infarct size was calculated by both hot spot imaging agents on dual nuclide SPECT. Antimyosin accurately accumulated in the infarcted area in all 11 patients on SPECT images corresponding with the electrocardiography, but pyrophosphate accumulated at the site of infarct in 10 of 11 patients. The mean volume obtained from pyrophosphate was 32.5 ml and that from antimyosin was 21.9 ml. The relationship between infarct volume calculated by pyrophosphate and that by antimyosin was linear and correlated well (r = 0.98, p less than 0.001). However the volume of infarction determined with pyrophosphate exceeded that with antimyosin SPECT by 1.64 (p less than 0.001). The reason for this difference is not yet known, but may relate to pyrophosphate uptake in border zones that may or may not be irreversibly injured.

Clinical application of indium-111 antimyosin antibody and thallium-201 dual nuclide single photon emission computed tomography in acute myocardial infarction.

The significance of indium-111 antimyosin antibody and thallium-201 dual nuclide single photon emission computed tomography (SPECT) was evaluated in 7 patients with acute myocardial infarction (AMI) who underwent emergency coronary angiography with successful revascularization by intracoronary thrombolysis. Indium-111 antimyosin antibody and thallium-201 dual nuclide SPECT was performed 11 to 36 days after the onset of AMI. Antimyosin SPECT images delineated areas of myocardial necrosis in all 7 patients (100%), but planar images detected necrotic areas in only 4 of 7 patients (57%). Peak CPK-MBs of the 3 patients in which no necrotic area was detected by indium-111 planar image showed a tendency to be smaller. Indium-111 antimyosin antibody/thallium-201 overlap was observed in all patients. The area of overlap was at the center of necrosis in 4 patients (2 anterior infarction, 1 inferior infarction, 1 inferolateral infarction) and at the peripheral portion in 3 patients (all 3 had inferior infarction). Indium-111 antimyosin antibody and thallium-201 dual nuclide SPECT is useful in identifying the localization of myocardial infarction and the overlap of these tracers might reflect the presence of salvaged myocardium adjacent to the necrotic myocardium.

High performance liquid chromatography determination of cyanide in urine by pre-column fluorescence derivatization.

A method for the determination of cyanide in human urine has been developed. The method is based on the reaction of cyanide with 2,3-naphthalenedialdehyde and taurine to give a fluorescent product for reversed-phase HPLC separation and fluorometric detection. After centrifugation followed by dilution of urine samples, the specimens could be analysed directly by this method. The recovery of cyanide added to urine at concentration levels of 50-1000 pmol/mL was 85-96%. The detection limit of cyanide was 30 pmol/mL in urine. The method was successfully applied to the analysis of urine from smokers and nonsmokers. The mean concentrations of cyanide were found to be 215 pmol/mL for the former and 84 pmol/mL for the latter.

Prediction of three-dimensional structure of Escherichia coli ribosomal RNA.

A model for the tertiary structure of 23S, 16S and 5S ribosomal RNA molecules interacting with three tRNA molecules is presented using the secondary structure models common to E. coli, Z. mays chloroplast, and mammalian mitochondria. This ribosomal RNA model is represented by phosphorus atoms which are separated by 5.9 A in the standard A-form double helix conformation. The accumulated proximity data summarized in Table 1 were used to deduce the most reasonable assembly of helices separated from each other by at least 6.2 A. Straight-line approximation for single strands was adopted to describe the maximum allowed distance between helices. The model of a ribosome binding three tRNA molecules by Nierhaus (1984), the stereochemical model of codon-anticodon interaction by Sundaralingam et al. (1975) and the ribosomal transpeptidation model, forming an alpha-helical nascent polypeptide, by Lim & Spirin (1986), were incorporated in this model. The distribution of chemically modified nucleotides, cross-linked sites, invariant and missing regions in mammalian mitochondrial rRNAs are indicated on the model.

Discovery of a human erythroid differentiation factor (EDF) and its large-scale production.

A novel human protein exhibiting erythroid differentiation activity was discovered in the culture fluids of phorbol ester-stimulated human cells. The differentiation assay system involving Friend virus-derived mouse leukemia cells was used. THP-1 cells of myelomonocytic origin were typical producers. 4beta-Phorbol 12-myristate 13-acetate (PMA) was essential for inducible excretion of the erythroid differentiation factor (EDF). The factor was stable toward heat and pH (acidic or alkaline) but lost its activity on pronase treatment, which suggested its proteinous nature. After an optimization of the condition, production of EDF was performed on a 200-L scale for purification of the protein.

Fluorometric determination of cyanide with 2,3-naphthalenedialdehyde and taurine.

A method is proposed for the fluorometric determination of cyanide based on a fluorogenic reaction with 2,3-naphthalenedialdehyde and taurine at basic pH. As little as 10 pmole of cyanide in 500 mul of sample can be determined.

Purification and characterization of erythroid differentiation factor (EDF) isolated from human leukemia cell line THP-1.

We isolated a protein, from a cell line of human origin, which exhibits extensive differentiation inducing activity toward Friend leukemia cells. The protein, called Erythroid Differentiation Factor (EDF), was found in a 4 day culture of THP-1 cells performed in the presence of 4 beta-phorbol 12-myristate 13-acetate(PMA). EDF is a homodimer of a molecular weight of 25,000, with an NH2-terminal sequence identical to that of the beta A-chain of porcine Inhibin. It was suggested that a single protein species is responsible for the activities of both EDF and FRP, a FSH releasing protein isolated from porcine ovarian follicular fluid.

[Observation of magnetic fields from three directions, and the moving image of the heart in a normal subject].

Three components of the magnetic field generated by the heart over the anterior aspect of the chest in a normal subject were detected using a Superconducting Quantum Interference Device (SQUID) magnetometer with a single detecting coil in a magnetically shielded room. Contour maps and color density maps of the field were prepared by computer. Movies of sequential magnetic fields of the vertical component on the anterior aspect of the chest were made from these maps. In the movies, the maximum moved from the upper central portion to right lower portion in the early stage of ventricular excitation. It moved to the central portion in the middle stage, then returned to the upper central portion in the late stage. Three-dimensional maps of instantaneous magnetic fields over the anterior portion of the chest were derived from maps of three components of the field, and from presumed heart vectors and were drawn as arrows, based on the Viot-Savart theorem. Heart vectors from these field maps corresponded well with septal forces in the early stage, left ventricular free wall force in the middle stage and the basal force in the late stage, respectively. However, large circulating vectors in the form of clockwise rotation in the central portion were also presumed. These circulating heart vectors did not correspond with the sequence of cardiac excitation as reported by Durrer et al. This discrepancy may have been caused by the fact that the vertical electric current could not be expressed from our display for presuming an electric force. Therefore, new displays and interpretations may be required for the expression of heart vectors.

[Hypereosinophilic syndrome associated with extensive asynergy of the left ventricular wall: a case report].

This is a report of a case of the hypereosinophilic syndrome associated with extensive asynergy of the left ventricular wall. This 41-year-old man's hospital admission in March, 1982 was for congestive heart failure, with marked eosinophilia (34%). Slight depression of the ST segments and flatness of the T waves were observed in electrocardiographic leads I, II, III, a VF, and V 5-6. Digitalis and diuretics were ineffective, but supplementary prednisone therapy resulted in a decrease in eosinophilia and improvement of congestive heart failure. He was transferred to our hospital for further examination in May, 1982. There were no signs of congestive heart failure, but a third heart sound was detected on admission. Marked ST segment depression and inverted T waves were observed in the left precordial leads. Echocardiography cardiography showed extensive asynergy of the left ventricular wall, and progressive enlargement of the left atrium and left ventricle. High density area near the apex of the left ventricle suggested the presence of mural thrombi. A left endocardial biopsy showed organized thrombi sparsely invaded by eosinophils. There were no signs nor symptoms of peripheral emboli. Tapering of the dose of prednisone was attempted twice, but each time eosinophilia resulted. The patient is now free of symptoms, and is being maintained on 25 mg of prednisone daily.