[Lymphatic circulation of the lung: general considerations].
Explore the source record for details and available documents.
Humans↗
Biomedical subjects
S Asakura
Publications and source records attributed to S Asakura.
Hydrophobic residues 382-386 of antithrombin III, Ala-Ala-Ala-Ser-Thr, serve as the epitope for an antibody which facilitates hydrolysis of the inhibitor by thrombin.
In the presence of a monoclonal antibody raised against the human thrombin-antithrombin III complex, the reaction between thrombin and antithrombin III proceeded to form preferentially a two-chain form of the inhibitor rather than to follow the major pathway of stable acyl complex formation. We thus propose the term "switching antibody" for an antibody that switches the enzyme-inhibitor reaction (Asakura, S., Matsuda, M., Yoshida, N., Terukina, S., and Kihara, H. (1989) J. Biol. Chem. 264, 13736-13739). By analyzing a CNBr fragment of the thrombin-antithrombin III complex that reacts with the antibody we localized the epitope for the antibody to a strongly hydrophobic residue 382-386 peptide segment, Ala-Ala-Ala-Ser-Thr, of the inhibitor, which is also contiguous with a hydrophobic amino acid Ala at its carboxyl terminus. This particular region should be cryptic in nascent antithrombin III, but could have been exposed to provide the reactive site for the antibody at an early stage of the reaction. Thereby a conformational change may have been induced at or near the reactive site of the complex, facilitating hydrolysis of the inhibitor by the enzyme. Interestingly, this hydrophobic region is highly conserved among members of the serpin family.
Amino Acid Sequence↗
[A bulky mass non-Hodgkin's lymphoma with dysuria in the rectovesical space].
A case of non-Hodgkin's lymphoma is reported. A 71-year-old man presented with complaint of dysuria and urinary frequency. Rectal examination and CT scan revealed a bulky mass in the rectovesical space. Transperineal needle biopsy of the tumor revealed non-Hodgkin's lymphoma, large cell type, diffuse. The patient received combination chemotherapy of adriamycin, cyclophosphamide, vincristine, prednisolone and pepleomycin. After two days the tumor was marvelously reduced in size, and partial response (PR) by CT was achieved after two months. PR was sustained for two months with cyclophosphamide, vincristine and prednisolone. However, the tumor progressed gradually, and he died five months after the first treatment and two additional courses of chemotherapy. Autopsy showed a 1,700 g bulky mass in the rectovesical space. The mass was covered with peritoneum and had a fistula from rectum to central necrosis of the tumor. Nine cases of the non-Hodgkin's lymphoma with complaint of dysuria have been reported in Japan before our case, which seemed to arise from the submucosal tissue of anterior rectal wall, prostate or lymphatic tissue of rectovesical space.
Aged↗
Total reconstitution of Salmonella flagellar filaments from hook and purified flagellin and hook-associated proteins in vitro.
Salmonella flagellar filaments comprise the following distinct parts connected in series: a curved hook composed of a single kind of subunit (hook protein); two short segments made up of hook-associated proteins (HAP1 and HAP3); a long helical filament composed of flagellin; and a cap composed of HAP2. In this study, a procedure was developed to isolate HAPs from the culture medium of a short-flagella mutant. We demonstrate that hook-filament complex can be formed in vitro by sequential addition of HAP1, HAP3 and flagellin to hook fragments.
Bacterial Proteins↗
A monoclonal antibody that triggers deacylation of an intermediate thrombin-antithrombin III complex.
Upon incubation of antithrombin III with thrombin in the presence of a monoclonal antibody recognizing an epitope exposed on the heavy chain part of thrombin-cleaved two-chain antithrombin III, antithrombin III was preferentially cleaved by the enzyme as a substrate, rather than covalently complexed with the enzyme to form an equimolar, stable acyl complex. Once the stable acyl complex was formed between the enzyme and antithrombin III, however, no further liberation of two-chain antithrombin III was observed. Kinetic studies showed that heparin does not affect this reaction, although generation of thrombin-cleaved two-chain antithrombin III is apparently accelerated in accordance with the rate constant for heparin-enhanced thrombin-antithrombin III complex formation. Here we propose the term "switching antibody" for an antibody that triggers deacylation of an intermediate enzyme-inhibitor complex by switching the enzyme-inhibitor reaction from the major pathway of stable acyl complex formation to an alternative pathway of cleavage of the inhibitor as a substrate.
Antibodies, Monoclonal↗
Calcium-triggered movement of regulated actin in vitro. A fluorescence microscopy study.
We previously reported setting up an in vitro system for the observation of actin filament sliding along myosin filaments. The system involved a minute amount of fluorescently labelled F-actin, and its movement was monitored by fluorescence microscopy. Here, we report observations of the Ca2+-dependent movement of F-actin complex with tropomyosin plus troponin (regulated actin) added to the movement system in place of pure F-actin. In a wide range of pCa (-log10[Ca2+]) between 3 and 5.5 at 30 degrees C, regulated actin filaments moved rapidly, and the average velocity depended little on the Ca2+ concentration (about 7.5 microns/s). However, when the Ca2+ concentration was decreased to pCa = 5.8 or lower, the filaments suddenly stopped moving. In striking contrast to these observations, unregulated actin moved rapidly within the whole pCa range examined, the average velocity (about 7.5 microns/s) being essentially Ca2+-independent. These observations indicate that (1) tropomyosin-troponin actually gave Ca2+-sensitivity to F-actin, and (2) the movement system was regulated by Ca2+ in an on-off fashion within a narrow range of Ca2+ concentration. In a pCa range between 5.8 and 6.0, regulated actin filaments did not exhibit thermal motion; instead, they had fixed positions in the specimen, possibly because they remained associated with myosin filaments in the background, without sliding past each other. Although regulated actin moved fast in the presence of 1 mM-CaCl2 (pCa = 3) at 30 degrees C, it became entirely non-motile as the temperature was decreased to 25 degrees C or lower. Such a sharp movement/temperature relation was never found for unregulated actin. We assayed regulated actin-activated myosin ATPase in the same conditions as used for microscopy, and found that the ATPase activity depended both on pCa and on the temperature considerably less than the movement of regulated actin. The results suggest that the sliding velocity in the in vitro system would not be proportional to the rate of actin-activated ATPase.
Actins↗
Synacrosomal formation after cell fusion of round spermatids of Xenopus laevis.
Cell fusion was induced by hypotonic medium in pairs of spermatids which were derived from single secondary spermatocytes. In a pair of fused spermatids, a single acrosome (synacrosome) eventually formed whenever the cell fusion was induced during the course of acrosomal formation. Direct observation of the process of synacrosomal formation was made on pairs of fused spermatids which had completed acrosomal formation. Two patterns occurred, namely, fusion of two acrosomes or enlargement of one with diminution of the other. The total volume of the two acrosomes before synacrosomal formation almost equaled the volume of the coalesced synacrosomes in fused spermatids. Neither colchicine nor cytochalasin B prevented synacrosomal formation in spermatids which were fused after each had completed acrosomal formation. These results indicate that neither microtubules nor microfilaments seem to play a role in the formation of a synacrosome in pairs of fused spermatids. However, cycloheximide did inhibit acrosomal formation when present during the early stage of acrosome differentiation in pairs of spermatids which had been fused just after second meiotic division. This fact indicates that acrosomal formation is mediated by some protein(s) which are synthesized during the initial period of acrosomal formation.
Acrosome↗
Clinical observations on fertile males with varicocele.
During the clinical observation of 32 fertile cases with varicocele interesting findings were made. Normal semen, a sperm density above 40 million/ml and a motile sperm rate of over 60% were observed in 46.9% of the cases. Furthermore, a sperm density of more than 40 million/ml was found in 75% and a motile sperm rate of more than 50% was detected in 81.3%, indicating normal or adequate spermogram data. A difference in right-left testicular size was recognized in 35.5% (11 cases). Only 2 of the cases had oligospermia and 9 cases had normospermia. Two cases had low testosterone values and low motile sperm rates were also detected. Secondary infertility occurred in 33.3%. In 25% of the cases, scrotal scintigraphy revealed an accumulation of high radioactivity indicating venous blood pooling over the affected site in the early phase of dynamic images. In the other cases, different venous flow characteristics were detected visually.
Adult↗
Improved technique of tubeless cutaneous ureterostomy and results of permanent urinary diversion.
An improved technique of tubeless cutaneous ureterostomy through a single stoma was devised by modifing the traditional cutaneous ureterostomy. Using this method, urinary diversions were performed on 12 cases with malignancies: 6 had radical cystectomy and the other 6 had pelvic exenteration. Normal bilateral ureters were observed in 11 cases in preoperative intravenous pyelography. Stomal stenosis was found in 1 case (8.3%) requiring operative stomal revision. Generally satisfactory results were obtained. This method could lower the incidence of complications. A long-term follow-up is needed, but 2 cases who have survived for more than 4 years since the operation have shown excellent results. It was thought that it would be difficult to perform tubeless cutaneous ureterostomy on normal-sized ureters, but our clinical results indicate that this method may be able to provide permanent urinary diversion.
Adult↗
The role of endogenous dopamine in congestive heart failure.
Although the effects of epinephrine and norepinephrine in congestive heart failure have been extensively studied, and exogenous dopamine, another of the catecholamines, has been widely used for the treatment of congestive heart failure, little attention has been paid to the physiological significance of endogenous dopamine in this condition. The present study was therefore designed to assess the physiological significance of endogenous dopamine in congestive heart failure. Nineteen patients with congestive heart failure caused by such conditions as acute myocardial infarction, valvular disease and dilated cardiomyopathy were examined before and after treatment with diuretics, digitalis and vasodilators. Electrolyte, creatinine and catecholamine concentrations in plasma and urine were analyzed. Urinary dopamine levels were increased in 13 out of 19 cases before treatment and returned to the normal range after treatment, falling from 2448 +/- 950.7 to 528.8 +/- 56.3 micrograms/day (normal level, less than 700 micrograms/day). Urinary dopamine excretion was markedly elevated within 24 hours after the onset of symptoms of heart failure, such as chest pain, palpitations and dyspnea. The relationship between urinary dopamine excretion and time after the onset of symptoms showed a strong statistical correlation (r = 0.55, p less than 0.001). Urinary dopamine excretion was also well correlated with plasma dopamine concentration, urinary norepinephrine excretion and venous pressure. From these results, it is concluded that endogenous dopamine seems to play an important role during the acute phase of congestive heart failure.
Adult↗
Fibrinogen Sapporo: dysfibrinogenemia characterized by the replacement of A alpha arginine-16 by histidine resulting in the delayed release of fibrinopeptide A by thrombin.
Congenital dysfibrinogenemia was found in a 60-year-old asymptomatic female and her daughter. Purified fibrinogen derived from the propositus, apparently a heterozygote for the abnormality, characteristically showed delayed but complete release of fibrinopeptide A upon digestion with thrombin but its defective release by Ancrod, a snake venom enzyme, from half of her fibrinogen molecules. This congenital dysfibrinogenemia with an A alpha arginine (Arg) to histidine (His) substitution was tentatively designated as fibrinogen Sapporo. Although this type of abnormal fibrinogen had been identified among Caucasians, no such cases have so far been reported in Japan.
Female↗
[Analysis of abnormal fibrinogens--introduction of new strategies].
Explore the source record for details and available documents.
Amino Acid Sequence↗
Preparation and characterization of monoclonal antibodies against the human thrombin-antithrombin III complex.
Monoclonal antibodies were raised against human thrombin-antithrombin III complex by a hybridoma technique. Among them, five monoclonal antibodies, designated as JITAT-4, -14, -16, -17 and -19, were found to react with thrombin-antithrombin III, but not with its nascent components, alpha-thrombin or antithrombin III. Their respective immunoglobulin classes are IgG1 for JITAT-16 and -19, and IgG2a for JITAT-4, -14 and -17. Besides the thrombin-antithrombin III complex, they all bound to the Factor Xa-antithrombin III complex and the active-site-cleaved two-chain antithrombin III as well. Moreover, the reactivity of these two antibodies to the neoantigens was not affected by heparin, suggesting that their epitopes are independent of heparin-induced conformational changes of antithrombin III. Two of them, JITAT-16 and -17, were categorized as high-affinity antibodies to thrombin-antithrombin III complex, the dissociation constants being 6.7 nM and 4.8 nM, respectively. However, they do not share antigenic determinants. These monoclonal antibodies may allow us to explore more precisely the reaction between antithrombin III and thrombin or its related enzymes.
Antibodies, Monoclonal↗
Formation of flagella during interphase in secondary spermatocytes from Xenopus laevis in vitro.
In cell culture, single motile flagella, 1 micron in length, were observed to grow from secondary spermatocytes of Xenopus laevis within 2-3 hours after telophase I, at 22 degrees C. About 90% of the secondary spermatocytes formed flagella as observed by phase-contrast microscopy. The flagella grew up to 2-6 microns in length during interphase II, which lasted about 18 hours. The presence of the "9 + 2" microtubular structure of the flagellar axonemes of secondary spermatocytes was confirmed by electron microscopy. When chromosomal condensation began (prophase II), the flagella were resorbed into the cells and, after the second meiotic division, a flagellum was formed again by each of the round spermatids. Thus, there appears to be a close relationship between the meiotic division cycle and the formation of flagella. The possible contribution of Sertoli cells to the formation of flagella in secondary spermatocytes was examined by reducing the number of Sertoli cells to less than ten per culture. Under these conditions, flagella formed in secondary spermatocytes with very high efficiency. It is very likely that secondary spermatocytes form flagella in vivo, since the secondary spermatocytes were observed to have flagella immediately after dissociation of the testes.
Animals↗
[Two cases of urethral leiomyoma].
Two cases of urethral leiomyoma are reported. Two Japanese women 39 and 28 years old presented with the complaint of a painless mass protruding from the anterior wall of urethra to urethral meatus. The mass was firm with associated condyloma acuminatum on its surface and was easily removed by surgical excision. Sixty-four cases of urethral leiomyoma have been reported in Japan before the present cases. The majority of them were in females. The peak of incidence was in the 30th to 40th decade, suggesting the relationship of urethral leiomyoma to female sex hormones. No malignant development has been described. Judging from these findings, it appears possible to differentiate leiomyoma of urethra from caruncle, urethral prolapse or urethral carcinoma by careful inspection and palpation of a mobile firm mass under epithelium.
Adult↗
[A case of malignant pleural mesothelioma and its sensitivity tests for anti-cancer drugs].
Explore the source record for details and available documents.
Animals↗
Stimulation of in vitro motility of Chlamydomonas axonemes by inhibition of cAMP-dependent phosphorylation.
When demembranated axonemes of Chlamydomonas were reactivated with Mg-ATP, the proportion of motile axonemes was significantly increased by the presence of either phosphodiesterase (PDE) or protein inhibitor of cAMP-dependent kinase (PKI). The effect of PDE was cancelled by the addition of cAMP. These findings strongly suggest that the axoneme samples have endogenous cAMP, which can reduce the proportion of motile axonemes via phosphorylation. This inhibitory effect of cAMP on Chlamydomonas axonemes is opposite to its stimulatory effect on the axonemal motility in other organisms so far reported. PKI or PDE activated the motility either in the absence of Ca2+, when the axonemes beat with an asymmetric waveform, or in 10(-5) M Ca2+, when the axonemes beat with a symmetric waveform. This cAMP-dependent regulation of motility was observed with the axonemes from which detergent-soluble material had been removed, indicating that the proteins responsible for the regulation still remained in the axonemes. Preliminary in vitro phosphorylation studies have implicated two polypeptides as candidates for the target protein of cAMP-dependent protein kinase: one with a molecular weight of 270 kD and the other with a much larger molecular weight.
Calcium↗
Declining trends in blood pressure level and the prevalence of hypertension, and changes in related factors in Japan, 1956-1980.
Trends in age-specific and age-adjusted blood pressure and the prevalence of hypertension were obtained from the National Nutrition Survey of Japan, 1956-1980. The national trends in the age-adjusted blood pressure of people (30-69 years old) in Japan during the 1956-1980 period show an increasing pattern reaching a peak around 1964 followed by a decreasing pattern. To explore the possible factors which have contributed to the change in blood pressure levels, we analyzed the relationship between the blood pressure and several possible factors, including the rate of treatment for cardiovascular diseases (CVD) for men and women, annual salt and alcohol consumption per captia and body mass index (MBI) for men and women. Only alcohol consumption was considered in the analysis of men because women in Japan still tend to drink relatively little alcohol. In simple descriptive analyses, the increasing trend in the treatment rates of CVD seemed to be related to the decrease in the blood pressure level and in the prevalence rate of hypertension for both men and women. The impact of treatment rate seemed to overcome the adverse influence of the increasing trends in BMI. Recent decrease in salt consumption may account in part for the later period of the decreasing trends in blood pressure level and the prevalence of hypertension. In multiple regression analysis using these time series data, CVD, BMI and alcohol consumption were significantly related to blood pressure level and the prevalence of hypertension, although salt was not significant in these analyses.
Adult↗