CYCLIC PEPTIDES: X. Bitter Taste and Chymotryptic Hydrolysis of Cyclic Depsidipeptides Containing a Tryptophan Residue*

Four stereoisomers (I-LL, I-LD, I-DL and I-DD) of a cyclic depsidipeptide (I) containing a tryptophan and a 2-hydroxy-4-methylpentanoic acid residue were synthesized, and their taste and chymotryptic susceptibility were examined. Compound I-LL is a depsipeptide analog of a bitter principle BP-II, cyclo(-L-Trp-L-Leu-), obtained from casein hydrolyzate. All of the four stereoisomers of I are strongly bitter to taste. Another depsipeptide analog, L-aspartyl-L-2-hydroxy-3-phenylpropanoic acid methyl ester, of the sweet H-L-Asp-L-Phe- OMe showed bitter taste instead of sweet. Chymotrypsin hydrolyzed I-LL and I-LD in moderate rates, and I-DL and I-DD very slowly.     

Echographic Detection of Latent Severe Thrombotic Stenosis of the Superior Vena Cava and Innominate Vein in Patients with a Pacemaker: Integrated Diagnosis Using Sonography, Pulse Doppler, and Color Flow

Thrombosis of the innominate vein and SVC is a serious complication in patients with pacemakers, inducing puhnonary embolism or SVC syndrome. Venography is the definitive method for its diagnosis; however, it is too invasive for related studies. The purpose of this study was to validate sonography, pulse Doppler, and color flow in detecting noninvasively innominate vein or SVC thrombosis in patients with pacemakers. In 53 patients with pacemakers, the 1 severe SVC stenosis and 18 severe innominate vein stenoses due to thrombosis were diagnosed by digital subtraction angiography. Sonography accurately showed the severe SVC stenosis due to thrombosis, but had limitations on the innominate vein thrombosis. Color flow demonstrated mosaic flow, indicating poststenotic turbulence due to stenosis of the innominate vein and SVC caused by thrombosis in 15 of 16 patients, and pulse Doppler disclosed absence of flow due to complete occlusion of the innominate vein in 2 of 2 patients. Sensitivity and specificity for detecting severe innominate vein stenosis due to thrombosis using combined color flow and pulse Doppler was 94% and 100%, respectively. In conclusion, sonography, pulse Doppler, and color flow allow accurate detection of severe innominate vein or SVC stenosis due to thrombosis, and are therefore useful for the follow-up of patients with a pacemaker.     

Trends in neonatal exchange transfusions at Yodogawa Christian Hospital

A review was conducted to determine the trends in exchange transfusion (ET) of newborn infants at the Yodogawa Christian Hospital during the past 18 years. At that hospital in 1957, the first ET was performed on a term infant with severe hemolytic jaundice caused by rhesus factor (Rh) incompatibility. By 1989, ET had been performed in more than 1400 newborn infants. These cases of newborns who had had ET were retrospectively reviewed, with a focus on every 3 year period from 1974 to 1992. The total number of infants requiring ET noticeably decreased from 68 cases (14.0% of total admissions) in 1974 to 19 cases (6.1% of total admissions) in 1992. (X², P < 0.001) There were three major significant changes in ET during those years. The first was a change in the subjects for ET. The incidence of ET for term infants showed a marked decrease, while the incidence of ET for preterm infants, especially for very low birthweight (VLBW) infants (< 1500 g), noticeably increased. The second was a change in indications for ET. There was a marked decrease in the need for ET as a result of hyperbilirubinemia, while the incidence of ET because of other etiologies, such as septicemia and/or disseminated intravascular coagulopathy, noticeably increased. The third was a change in the technical methods of ET. Now at the Yodogawa Christian Hospital, 100% of the infants are given ET with an automated peripheral two-site method, instead of the Diamond method. Although ET might still be a useful treatment for severe hyperbilirubinemia and other acute problems, the total number of ET noticeably decreased in accord with a decrease in the number of severe hyperbilirubinemia in term newborns. On the other hand, the incidence of ET in preterm infants increased relatively, accompanied by an increase in the survival of VLBW infants. The automated two-site method is the preferred technique for ET at the Yodogawa Christian Hospital, rather than the Diamond method. Further changes in ET might occur in accord with new alternative measures in future.     

Analysis of Fibrinolysis by the Use of Epsilon-Aminocaproic Acid: Preliminary Report

From the foregoing analysis of the inhibitory action of -aminocaproic acidin the fibrinolytic process, it is evident that the process involves two reactionphases, fibrinolysis and metafibrinolysis.

Fibrinolysopeptide and metafibrin are split off from fibrin in fibrinolysis.The former is a peptide with N-terminal glycine, while the latter is a monochloracetic acid-soluble metaprotein having both aspartic acid and tyrosineas N-terminal amino acids.

     

Diagnostic System for Helicobacter pylori Urease Based on a pHsensitive Field Effect Transistor

A rapid diagnostic system for Helicobacter pylori (H. pylori) was developed based on an urease analyser using a pH-sensitive field effect transistor (pH-FET). The system is composed of a solid-phase capillary-tube and a pH-measuring cell. The solid-phase tube, with an inner diameter 0.55 mm and coated with a monoclonal antibody against H. pylori's urease, was used to selectively capture the urease in endoscopically collected gastric mucus. The urease activity on the inner surface of the solid-phase tube was measured by coupling it with ph-FET in a pH measuring cell containing urea solution. Before immuno reaction in the solid-phase, gastric mucus was diluted with a phosphate buffered saline containing 1% n-octylglucoside, which was effective for accelerating the release of active urease from H. pylori's cells suspended in the sample solution. As a result of preliminary evaluations, it was found that the clinical sensitivity and specificity were 100 and 86%, respectively, using a bacteriological test as a reference.     

A Case of Esophageal Carcinoma and Collision Tumor of the Stomach

A case of double primary cancer of the esophagus and stomachwith metastasis of the esophageal cancer to the stomach is reported.The entire stomach and the lower part of the esophagus weresurgically resected and intrathoracic esophagojejunostomy wasperformed. Macroscopically, two tumors were found to be present,both in the lower esophagus and the stomach. There were twoprimary cancers, one a squamous cell carcinoma of the esophagusand the other a collision tumor of the stomach which consistedof well-differentiated adenocarcinoma and signet ring cell carcinoma.Furthermore, this collision tumor was present together witha metastatic lesion from the esophageal carcinoma.