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Biomedical subjects

K Amano

Publications and source records attributed to K Amano.

At least 199 records · Page 11Linked to original sources

A phage in Bartonella bacilliformis.

Bacteriophage-like particles were found in Bartonella bacilliformis culture. The particles consisted of head (icosahedral), 40 nm in diameter, and tail, 16 nm in length.

Bacteriophages↗

Structural studies of peptidoglycans in Campylobacter species.

Peptidoglycans (PG) from Campylobacter coli, Campylobacter jejuni, and Campylobacter fetus were composed of muramic acid, glucosamine, alanine, glutamic acid, and diaminopimelic acid in a molar ratio of 1.1:1:1.7:1.1:09. Thirty percent of the amino groups of diaminopimelic acid were involved in cross-linkages between peptides. During cultivation, C. coli and C. jejuni changed from a spiral to a coccoid form. In C. coli, we could isolate PG only from the spiral forms in yields of 0.8-1.2% by dry weight. C. fetus did not change to a coccoid form, and always contained PG. Thus, it is possible that the morphological transformation from the spirals to the coccoid forms of C. coli and C. jejuni is accompanied by, and probably due to, the degradation of PG.

Campylobacter↗

Serological studies of antigenic similarity between Japanese spotted fever rickettsiae and Weil-Felix test antigens.

Acute and convalescent-phase sera obtained from 10 patients infected with a Japanese strain of spotted fever group (SFG) rickettsia were tested by the indirect immunoperoxidase test, the Weil-Felix test, an enzyme-linked immunosorbent assay (ELISA), and immunoblotting. By the Weil-Felix test, the reactivity of these sera to the OX2 antigen was higher than those to the OX19 antigen, as is the case with sera from persons infected with other SFG rickettsiae. By ELISA, the titers of immunoglobulin M (IgM) antibodies against OX2 corresponded to the Weil-Felix test titers of these sera against OX2 but not to the titers obtained with IgG antibodies. The reactivity of the patient sera with the OX2 antigen in the Weil-Felix test was probably due to IgM antibodies against antigens which OX2 and SFG rickettsiae have in common. By immunoblotting tests, both IgG and IgM antibodies from the patient sera reacted with lipopolysaccharides from SFG rickettsiae and Proteus strain OX2. These results may show that these lipopolysaccharides contain similar epitopes.

Antibodies, Bacterial↗

Stereotactic mesencephalotomy for pain relief. A plea for stereotactic surgery.

Rostral mesencephalic reticulotomy (RMR) for pain relief was performed in 34 patients with intractable pain. Most of these patients have been followed for a long period of time postoperatively, the longest follow-up period being 11 years. Contrary to the commonly prevailed bias in the past that mesencephalotomy may be a surgical intervention with potential risk, these patients of RMR have continued to substantial improvement postoperatively in terms of their preoperative intractable painful dysesthesia after a long period of time. The results of pain relief for denervation pain as well as for nondenervation pain are surprisingly good even after unilateral procedures. There was no operative mortality. Postoperative disturbance of ocular motility has been reduced. RMR has its scientific basis in that the medial part of the reticular formation rather than the classical lateral spinothalamic tract has more significance in the central conduction of nociceptive impulses through the midbrain level, which was verified by intraoperative neuronal recording with a tungsten microelectrode. The present report emphasizes that stereotactic mesencephalotomy, if performed meticulously and precisely, is a safe surgical procedure for pain relief. Results of MRI and sensory manifestations of a patient 11 years after RMR are also presented.

Follow-Up Studies↗

[Group theoretical approach to the cognition of transformational structures and goodness of patterns].

In this article, we tried to reformulate the transformational structure theory of goodness judgment of patterns within the framework of the group theory. We found that reformulation based on the group concepts results in a more general theory, which we call the transformation group theory of goodness judgment of patterns. Main properties of the generalized theory are: 1. Each of the basic cognitive transformations is replaced by a transformation group. 2. They are the dihedral group consisting of mirror-image transformations and a cyclic transformation, the translation group, and the value-reversal transformation group. These groups are derivable independently of the given configurations. 3. The transformation group has the following properties: duality of invariance, non-divergency of transformations produced, and availability of indirect test of invariance. These properties are convenient for cognition of transformational structure of patterns in goodness judgment. 4. The intraconfigurational transformation structure of configurations can be defined by the transformation group so that order among goodness judgments can be predicted, in parallel with the existing transformational structure theory.

Cognition↗

The reactivity between rickettsiae and Weil-Felix test antigens against sera of rickettsial disease patients.

Of the sera which were positive to Rickettsia tsutsugamushi by indirect immunoperoxidase test, approximately 80% sera were positive to a Proteus OXK antigen by Weil-Felix test at 10 or more days after the onset of fever, while only 10% sera were positive within 9 days from the onset of fever. In ELISA using the OXK antigen, almost all of the paired sera of tsutsugamushi disease (TD) patients increased on the IgM antibody titres with the rise of their titres by Weil-Felix test, whereas the IgG antibody titres of these sera were unrelated with the titres of Weil-Felix test. We suspect that the reactivity of TD patients sera to the OXK antigen in Weil-Felix test was derived from the reactivity of the IgM antibody against the OXK antigen common with R. tsutsugamushi. The patient sera infected with a Japanese isolate of spotted fever group rickettsia (SFGR) cross-reacted with the Thai Tick Typhus (TTT) strain of SFGR by indirect immunoperoxidase test. In Weil-Felix test, the reactivity of these sera to OX2 antigen were higher than that to OX19 antigen, like the sera infected with other SFGR, except of R. rickettsii. These sera also reacted with TTT and OX2 antigens by ELISA. The titres of IgM antibody against OX2 antigen in the sera in ELISA were in parallel with the titres of the sera against OX2 antigen in Weil-Felix test, but not the titres of IgG antibody. We suggest that the reactivity of the patient sera infected with SFGR to OX2 antigen of Weil-Felix test is dependent on the IgM antibody.

Antigens, Bacterial↗

[Effect of suppletory estrogen or 1,25(OH)D3 on bone mineral content].

Post-menopausal changes in bone mineral content (BMC) and the effect of suppletory estrogen or 1,25(OH)D3 was studied. BMC was evaluated by means of quantitative computed tomography. Post-menopausal BMC (age 45-49) was 158.4 +/- 42.0 mg/cm3 which was significantly lower than in other subjects in the same aged group (192.3 +/- 27.1 mg/cm3). At two years, ten years and more than ten years post-menopause it decreased significantly by 17%, 30%, 55% respectively, compared with that of pre-menopausal BMC. The administration of conjugated estrogen (0.625 mg) or 1,25(OH)D3 was effective in preventing bone loss, although a transient decrease in BMC was observed in some cases to which 1,25(OH)D3 was administered. In cases of pre-menopausal bilateral oophorectomy, BMC was found to decrease significantly to the post-menopausal level about two years after operation. However, long-term estrogen replacement therapy tends to inhibit the decrease.

Aged↗

[Studies on clinical remission of rheumatoid arthritis].

Clinical remission was observed in 19 out of 276 patients with rheumatoid arthritis. Remission rate was higher in male patients. In order to determine the clinical characteristics of remission cases, comparative study was performed. Although the time between initiation of treatment and clinical remission varied from case to case, the remission was related to early diagnosis and use of immunomodulating drug. No exacerbation was observed in our 19 patients with remission for the periods of 17 observation months. However, serial X-ray examination of hands disclosed that the erosive changes developed even after clinical remission.

Adjuvants, Immunologic↗

6-Deoxy-D-talan and 6-deoxy-L-talan. Novel serotype-specific polysaccharide antigens from Actinobacillus actinomycetemcomitans.

Serotype-specific polysaccharide antigens from Actinobacillus actinomycetemcomitans ATCC 29523 (serotype a) and NCTC 9710 (serotype c) were extracted from whole cells by autoclaving and purified by ion-exchange chromatography and gel filtration. Analysis of component sugars by gas-liquid chromatography-mass spectrometry, high performance liquid chromatography, and NMR together with optical rotation data showed that the serotype a antigen was composed solely of 6-deoxy-D-talose, whereas the serotype c antigen consisted of 6-deoxy-L-talose. Structural analysis indicated that both of these antigens were composed of closely related repeating units, -3)-6-deoxy-alpha-D-Talp-(1-2)-6-deoxy-alpha-D-Talp-(1-(sero type a) and -3)-6-deoxy-alpha-L-Talp-(1-2)-6-deoxy-alpha-L-Talp-(1-(sero type c). 1H and 13C NMR analysis showed that both of these serotype antigens contained one acetyl group/2 sugar residues. These acetyl groups localized at the O-2 position of 3-linked 6-deoxy-D-talose (serotype a) or O-4 position of 3-linked 6-deoxy-L-talose residues (serotype c), respectively. These results coupled with our previous findings on the serotype b antigen (Amano, K., Nishihara, T., Shibuya, N., Noguchi, T., and Koga, T. (1989) Infect. Immun. 57, 2942-2946) showed that the serotype antigens from A. actinomycetemcomitans are a group of novel polysaccharides with structural features closely related biosynthetically.

Actinobacillus↗

An ultrasound-guided stereotactic apparatus for intracranial mass lesions.

One of disadvantages of conventional stereotactic operation for intracranial mass lesions is that it is basically a blind procedure even if the operation is performed in a gantry of a CT scan. High resolution ultrasound image gives real-time information on intracranial pathology such as bleeding, remaining cyst fluid or haematoma. The authors report an ultrasound guided stereotactic apparatus which gives real-time images of the lesion during operation.

Biopsy, Needle↗

Bilateral versus unilateral percutaneous high cervical cordotomy as a surgical method of pain relief.

The present report is concerned with the results of bilateral percutaneous high cervical cordotomy (60 patients) compared with those of unilateral cordotomy (161 patients). The result of pain relief is classified into 4 grades based on Hitchcock's criteria; grade 1: complete pain relief, grade 2: almost complete pain relief with slight residual pain, grade 3: persisting pain, but tolerable, grade 4: persisting pain, untolerable. In cases of bilateral cordotomy (60 patients), 76% of the cases showed grade 1, 19% being grade 2, 3% being grade 3 and 2% being grade 4. On the contrary, the unilateral cordotomy (161 patients) showed less impressive results, particularly in grade 1, namely, grade 1 being 64%, grade 2 being 18%, grade 3 being 14% and grade 4 being 4%. Clinically acceptable results (grade 1 plus grade 2) were, therefore, obtained in bilateral cordotomy (95%) as compared with unilateral cordotomy (82%). The difference in pain relief between bilateral and unilateral procedure observed in the present investigation is contrary to that reported previously by others. The possible explanation for less impressive result in regard to grade 1 of unilateral cordotomy is that unilateral cordotomy was performed in this series to alleviate the major side of patient's pain, followed by latent pain on the other side postoperatively, which is not uncommon phenomenon in cancer pain. Whereas all of the bilateral cordotomies were done either for midline pain or bilateral pain, unilateral cordotomy gave satisfactory pain relief in some cases of midline pain. Midline pain, therefore, does not necessarily require bilateral cordotomies from a clinical point of view.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Gastric antral vascular ectasia.

A case of gastric antral vascular ectasia confined to the antrum in an elderly Japanese male patient is described. The condition is a cause of blood loss and chronic iron deficiency anemia, particularly in the elderly. The clinical, endoscopic, and pathologic findings, which were contrasted with other hyperplastic or gastric vascular abnormalities, are described.

Aged↗

Electron microscopic studies on the in vitro proliferation of spotted fever group rickettsia isolated in Japan.

Rickettsia was isolated from a patient with Japanese spotted fever, and its proliferation in cultured green monkey kidney cells was observed by electron microscopy. In the course of this study, we observed fusion of infected cells to uninfected cells which may be a way of spreading the rickettsiae from a cell to another. On the other hand, whirlpool-like, multilayer membranous structures, similar to the mesosomes of gram-negative bacteria, were sometimes seen in the rickettsial cells. The other profiles common to the other rickettsiae in spotted fever group were observed, such as the electron-lucent halo zone around the rickettsiae, and external fibrous materials on their surface, but intranuclear multiplication was rarely observed.

Cell Division↗

The presence of anti-protein A antibodies in patients with rheumatoid arthritis.

Sixteen patients with rheumatoid arthritis (RA) were examined for the presence of anti-protein A antibodies. The F(ab')2 preparations from five RA patients showed significant binding to IgG-free protein A on ELISA. The protein A binding was further examined by immunoblotting. The F(ab')2 preparations of high protein A-binding protein gave a specific reaction with IgG-free protein A on nitrocellulose paper. This demonstrates the presence of anti-protein A antibodies in patients with RA. Those RA patients with anti-protein A antibodies had more active disease as judged by the Lansbury's activity index. The level of serum rheumatoid factor (RAHA) was significantly higher in patients with anti-protein A antibodies than in those without anti-protein A antibodies.

Adult↗