Pancreatic Pseudocyst after Fully Covered Self-expandable Metallic Stent Placement: A Case Report

A 70-year-old woman presented with stage III pancreatic head cancer. After endoscopic sphincterotomy, a fully covered self-expandable metallic stent (FCSEMS) was placed in the common bile duct to manage jaundice. The patient developed a fever and abdominal pain 40 days after stent placement, with a suspected diagnosis of infected pancreatic pseudocyst. Purulent discharge from the papilla was observed during FCSEMS removal, and pancreatography revealed a pseudocyst connected to the main pancreatic duct. The pancreatic pseudocyst resolved after transpapillary drainage. Pancreatic pseudocysts should be suspected after biliary FCSEMS placement, and prompt removal and endoscopic drainage of the FCSEMS should be considered.

Clinical Outcomes of S-1 Monotherapy and Modified FOLFIRINOX Therapy after Gemcitabine plus Nab-paclitaxel Therapy in Unresectable Pancreatic Cancer

Objective S-1 and modified FOLFIRINOX (mFFX) were often used as the second-line chemotherapies after failure of gemcitabine plus nab-paclitaxel (GnP) in unresectable pancreatic cancer (UPC) until nanoliposomal irinotecan plus 5-fluorouracil/leucovorin therapy was approved as an alternative in Japan in 2020. However, the clinical outcomes of S-1 and mFFX after GnP have scarcely been reported. Therefore, we retrospectively studied them. Methods We extracted the clinical data of 86 patients with UPC who received second-line chemotherapy after GnP between 2015 and 2020. Among the patients who had a good organ functions and no massive ascites, 41 patients treated with S-1 and 21 treated with mFFX were enrolled. Results Compared to S-1, mFFX tended to be used for younger patients with a good general condition (median age, 63 vs. 71 years, p<0.01; and performance status 0, 67% vs. 37%, p<0.05). The median progression-free and overall survival were similar between the S-1 (3.7 and 7.2 months, respectively) and mFFX (3.3 and 7.4 months, respectively) groups. The response rate in patients with measurable lesions was 4% (n=1/23) in the S-1 group and 17% (n=2/12) in the mFFX group. The incidence of grade 3 or 4 adverse events was 20% in the S-1 group and 57% (neutrophil count decreased in 43%) in the mFFX group (p<0.01). Conclusion S-1 and mFFX were both acceptable second-line chemotherapies after GnP therapy for UPC, although attention should be paid to myelosuppression during mFFX treatment. Further studies involving nanoliposomal irinotecan plus 5-fluorouracil/leucovorin therapy are necessary to facilitate the selection of the optimal regimen for each patient.

Quadrics and Scherk towers

We investigate the relation between quadrics and their Christoffel duals on the one hand, and certain zero mean curvature surfaces and their Gauss maps on the other hand. To study the relation between timelike minimal surfaces and the Christoffel duals of 1-sheeted hyperboloids we introduce para-holomorphic elliptic functions. The curves of type change for real isothermic surfaces of mixed causal type turn out to be aligned with the real curvature line net.

Effects of acute exercise on visual reaction time

We examined the effects of acute exercise on reaction time to visual stimuli presented in the central portion and periphery of the visual field. Twelve participants performed reaction time tasks at rest and during cycling at 65 % peak oxygen uptake in two visual conditions. We used circular black-and-white checkerboard patterns as visual stimuli. The participants were asked to respond as quickly as possible to pattern reversal of the visual stimulus by releasing a response button. Reaction time was fractionated into Premotor time and Motor time. Premotor time in the peripheral condition significantly increased (p < 0.025) during exercise (mean +/- SE; 195.9 +/- 7.9 ms) from that at rest (183.7 +/- 6.8 ms). Premotor time in the central condition did not differ between at rest (185.3 +/- 7.6 ms) and during exercise (188.4 +/- 6.6 ms). These data suggest that the ability to respond to visual stimuli presented in the periphery of the visual field is vulnerable to moderate to severe exercise, as compared with the ability to respond to visual stimuli presented in the central portion of the visual field. An exercise-induced increase in arousal level and a consequent narrowing of attentional focus would explain the present results.

New lidocaine ester derivatives with a prolonged anesthetic effect

In order to find a new long acting local anesthetic, methyl, ethyl, and butyl ester derivatives of lidocaine were synthesized in our laboratory. The topical anesthetic activity was studied with the effects on corneal reflex in rabbits, and the duration of action with those on the action potential of rabbit vagus nerve was studied in vitro. All drugs showed adequate topical anesthetic activities. The onset time to induce a complete blockage of the action potential in the excised vagus nerve was 97.1 +/- 6.3 s for lidocaine, 289.3 +/- 29.0 s for methyl ester, 186.3 +/- 18.4 s for ethyl ester, and 85.3 +/- 9.0 s for butyl ester. The mean duration of action, which was assessed as the time to recover from the complete block to 30% of control amplitude in a drug-free medium, was 32.5 +/- 3.1 min for lidocaine, 39.9 +/- 11.3 min for methyl ester, 68.2 +/- 4.2 min for ethyl ester, and 108.7 +/- 12.3 min for butyl ester. The differences in the duration of action between the ester derivatives and the original lidocaine were all statistically significant. The duration of action of all drugs studied paralleled with their protein binding capacities. These findings indicate the possibility that the ester derivatives studied, especially butyl ester, can be used as a long acting local anesthetic.

[Improvement of inter-assay for the standardization of PT and TT--clinical significance of local standardization method]

We performed a nationwide Inter-assay including 112 laboratories for the standardization of prothrombin time (PT) and thrombotest (TT). The data were expressed as seconds, percentile and INR. INR was expressed by 2 methods; Method I (conventional method): INR was expressed using each ISI assigned for reagent or reagent-instrument at the respective laboratories and Method II (local standardization method): INR was expressed using each reference curve created with INR assigned standard plasmas at the respective laboratories. (1) Sample distribution of PT as well as TT was the smallest with the data expressed by Method II followed by Method I and then by percentile. The data expressed by seconds was widely distributed and not useful for the standardization of PT and TT. (2) Even the sample distribution obtained by Method II was dependent on the different ISI of the reagents, as it was found that the larger the ISI of the reagents, the wider the distribution of data. (3) The difference between PT and TT of each test plasma was analysed by t-test. It was found that the difference was insignificant when both data were expressed by Method II, but significant when expressed by Method I, suggesting that PT and TT were interchangeable with the use of Method II. (4) Sample distribution of percentile expression and INR with the use of method II was compared. It was revealed that the sample distribution of INR was smaller than that of percentile. It was concluded that INR expressed by the local standardization method was most useful for the standardization of PT and TT.

[Proton magnetic resonance study on the interaction of lidocaine derivatives with lecithin vesicles]

The interaction of lidocaine hydrochloride or lidocaine ester derivatives with lecithin vesicles was investigated by proton magnetic resonance (1H-NMR) spectroscopy. Signal broadening of drug indicated the incorporation of the drug into the vesicle membrane. Positively charged nitrogen of lidocaine hydrochloride interacted with polar part of the lecithin vesicles. On the other hand, lidocaine ester derivatives indicated interaction with lecithin vesicles not only by positive charge of nitrogen but also by electrostatic effect of ester carbonyl group. This may be related with the prolonged duration of lidocaine ester derivatives.

[Assay of glycated fibrinogen in plasma as an indicator of blood glucose control]

A method of assay for glycated fibrinogen (C-Fbg) in plasma has been developed. This method is based on the measurement of 1-deoxy-1-morpholino-D-fructose (DMF) in the fibrinogen (Fbg) solution separated from plasma and redissolved. Twenty five NIH units of thrombin was added to 600 microliters of plasma. After incubation, the fibrin clot was separated and washed. The fibrin clot was redissolved with Owren's veronal buffer contained urokinase. After incubation, DMF was measured using a Fructosamine Kit. G-Fbg measured by this method correlated significantly with the amount of furosine that was a specific product by hydrolysis of glycated lysine residue. In this method, the CV for intraday assay ranged from 2.0 to 3.6% and that for interday assay was 3.9%. The average of G-Fbg values in 78 diabetic patients (23.8 +/- 10.7 mumol DMF/g Fbg) was significantly higher than in 26 normal subjects (9.2 +/- 3.8 mumol DMF/g Fbg). The G-Fbg value correlated with blood glucose at the same time or one day earlier than 1-2 weeks or 1 month earlier. These results suggest that assay of G-Fbg by this method may be useful in monitoring short-term control of blood glucose in diabetic patients.

Relationship between the pharmacological effects of benzodiazepines and their in vivo binding sites in the brain of rats

To compare the in vitro pharmacological effect and in the brain distribution of benzodiazepines and phenobarbital, three group of sixty anesthetized rats (470-480 g) were administered 5 microCi of 3H-diazepam, 3H-flunitrazepam or 3H-phenobarbital. The rats were decapitated 3, 10, or 40 minutes after the intravenous injection of these drugs. Radioactivity of the tissue was measured and calculated as d.p.m./g. tissue. 3H-diazepam radioactivity in the brain-stem and hypothalamus was significantly higher than in the brain cortex 3 and 10 minutes after the injection. 3H-flunitrazepam radioactivity in the brain cortex was higher than in other regions. There was no significant decrease in 3H-phenobarbital brain concentration, even 40 minutes after injection. The distribution of benzodiazepine is closely related with its pharmacological effect, and this suggests that in vitro benzodiazepine binding sites are not responsible for the pharmacological action in vivo.

The effects of 30% nitrous oxide on auditory evoked middle latency responses

The effects of 30% nitrous oxide on auditory evoked middle latency responses (MLR) were studied in 11 healthy volunteers. The evoked potentials were averaged from electroencephalograms following stimulation by 2048 clicks at 10 Hz and of 0.5 ms duration. Latencies and amplitudes of the Pa-Nb wave were measured and compared with the control values. The mean amplitude after inhalation of nitrous oxide for 30 minutes nitrous oxide was 54.2 +/- 23.9 (SD) % of control value. This decrease was recognised as statistically significant (P less than 0.05). Latencies of the Pa-Nb wave did not alter during the inhalation of nitrous oxide. The results show that 30% nitrous oxide slightly suppressed the auditory cortex.

Radioallergosorbent test (RAST) for specific IgE antibody to lidocaine, procaine and methylparaben

Although anaphylactoid reactions to local anesthetics are well known, a radioallergosorbent test (RAST) to detect specific drug reagin (IgE) anti-body has not been developed. We established RAST for local anesthetics by using carboxylic acid derivatives of lidocaine, procaine and methylparaben. Serum samples were taken from 100 volunteers who were regarded to be nonallergic to the drugs used. Negative RAST values obtained from these volunteers were 1653 +/- 254(SD) cpm (lidocaine), 2750 +/- 264 cpm (procaine), and 2805 +/- 336 cpm (methyl paraben).

Primary tracheoesophageal shunt operation for postlaryngectomy speech with sphincter mechanism

This paper describes a primary voice restoration technique designed to eliminate the problem of aspiration commonly encountered in rehabilitation procedures following laryngectomy. This technique, utilized in 16 patients, consists of a unique combination of tracheal flap for voice production and bilateral esophageal constrictor muscle flaps to prevent aspiration. Fourteen patients developed satisfactory tracheoesophageal speech; of them 12 had normal deglutition without problems of aspiration. On radiographic examination, the bilateral esophageal muscle flaps, in combination with the dilatation and elevation of the cervical esophagus, provide a sphincter mechanism that prevents tracheal reflux during deglutition.

General anesthesia and surgical stress increase plasma immunoreactive beta-endorphin-like substances

The concentrations of human immunoreactive beta-endorphin-like substances in plasma were measured as a means of determining the effects of general anesthesia and surgical stress on the endogenous morphine-like substances. Sixty-nine adult patients and 44 pediatric patients who had undergone oral surgery in general anesthesia were the subjects of this study. In comparison to the control values, the results of this study showed an increase of beta-endorphin concentration in the plasma during anesthesia and surgery. The increase was particularly significant in the patients who had relatively a major surgical stress and in those patients showing a weak anesthetic action, while the patients with relatively a minor surgical stress or strong anesthetic action showed a small increase. From these findings, it seems proper to assume that the secretion of beta-endorphin in the plasma is accelerated by general anesthesia and surgical stress than to assume that the amount of beta-endorphin in the plasma is increased by the administration of anesthetic agents.

Primary tracheoesophageal shunt operation for postlaryngectomy voice restoration--a sphincter mechanism against aspiration

Out of a total of 113 consecutive tracheoesophageal (TE) shunt operations for postlaryngectomy voice restoration in the past 8 years performed at the Department of Otorhinolaryngology, 92 patients (81%) succeeded in the postoperative TE speech. The essential part of this surgery consists of the construction of the TE shunt using the membraneous part of the trachea obtained at surgery. In the course of 8 years, important changes have been employed for the prevention of aspiration. We attempted to combine primary cancer surgery with the creation of intelligible voice, but without aspiration. For the above purpose, we have employed the bilateral esophageal muscle flaps (BEMF) against aspiration in combination with the TE shunt construction for phonation. Sixteen of 18 patients thus operated on complained of no aspiration even with a drop of saliva and dietary fluids. As far as the mechanism against aspiration is concerned, both dilatation and elevation of the cervical esophagus during deglutition, together with the BEMF, seem to approximate the sphincter mechanism against tracheal reflux. A proper case selection may achieve high success rates for preserving normal deglutition and restoring speech after total laryngectomy.

Elimination of sex factors in Escherichia coli by urea

Eliminatory action of urea on the sex factor (F) in Escherichia coli K-12 strains is reported. Growth of E. coli harboring F or F'8 (F-gal) factors in Penassay Broth containing urea led to the loss of these genetic elements and yielded F(-) cells. Appearance of F(-) cells among survivors was already observed when the culture was in the very early stage of exponential phase. However, frequencies of F(-) cells formed did not increase much as a function of the incubation time. Unusual F(+) or F'8 cells which retained the ability of genetic transfer but showed resistance to M12 phage were also isolated. Addition of sucrose to broth with urea led to the favorable growth of cells in the culture and the increase, if little, of elimination frequencies of F factors by urea. These findings, coupled with other observations, suggest that urea has two separate actions in enhancing the frequency of F(-) bacteria, namely, (i) to inactivate F by direct action, such as mutation, and (ii) to select the F(-) variants by differentially inhibiting the growth of F(+).