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Biomedical subjects

I Katsuki

Publications and source records attributed to I Katsuki.

13 recordsLinked to original sources
PubMed2001

Correlation among crystal shape, absolute configuration, and circular dichroism spectrum of enantiomorphs of Tris[2-(((2-phenylimidazol-4-yl)methylidene)amino)ethyl]-aminemetal(II) nitrate-methanol (1/1).

A series of metal(II) complexes of a tripod-type ligand with the chemical formulas [M(H(3)L)](NO(3))(2).MeOH (M = Mn (1), Fe (2), Co (3), Ni (4), Zn (6)) and [Cu(H(3)L)](NO(3))(2).CH(3)CN.H(2)O (5) were synthesized and characterized (H(3)L = tris[2-(((2-phenylimidazol-4-yl)methylidene)amino)ethyl]amine). The crystal structures were determined, in which those of 1-4 and 6 are isomorphous and conglomerates, because they crystallize into the acentric space group P2(1)2(1)2(1). Each metal(II) ion of 1-4 and 6 assumes an octahedral coordination environment with the N(6) donor atoms of the tripod ligand and becomes either a C (clockwise) or an A (anticlockwise) enantiomorph because of the screw arrangement of the tripod-type ligand around the metal(II) ion. The crystals were divided into two groups, where their crystal shapes are mirror images and their CD spectra show enantiomeric patterns. The circular dichroism (CD) spectrum of the crystal used for the X-ray analysis was measured. The absolute configuration of the enantiomorph of the crystal used for the X-ray analysis was determined by the Flack parameter. The correlation among the crystal shape, the absolute configuration, and the CD spectral pattern was thus confirmed for 1-4 and 6. On the other hand, 5 assumes a square pyramidal coordination geometry with the N(5) donor atoms, and hence, there are no optical isomers.

Journal Article↗
PubMed2000

Synthesis, characterization, and spontaneous resolution of chiral nickel(II) complexes with the tripod ligand tris[2-(((2-phenylimidazol-4-yl)methylidene)amino)ethyl]amine.

The chiral nickel(II) complexes of a tripod-type ligand with the chemical formulas [Ni(H3L)](NO3)2.MeOH (1), [Ni(H3L)](ClO4)2.MeOH (2), and [Ni(H3L)](C6H5COO)2.6H2O (3) were synthesized and characterized (H3L = tris[2-(((2-phenylimidazol-4-yl)methylidene)amino)ethyl]amine). The crystal structures of 1-3 were determined by their single-crystal X-ray analyses. 1, C37H40N12O7Ni: orthorhombic, P2(1)2(1)2(1); a = 14.198(2) A, b = 22.422(2) A, c = 12.019(2) A, Z = 4. 2, C37H40N10O9Cl2Ni: orthorhombic, P2(1)2(1)2(1); a = 14.206(2) A, b = 22.735(3) A, c = 12.696(3) A, Z = 4. 3, C50H58N10O10Ni: triclinic, P1; a = 14.191(5) A, b = 16.048(4) A, c = 13.692(4) A, alpha = 115.25(2) degrees, beta = 111.07(3) degrees, gamma = 64.75(2) degrees, Z = 2. Each complex has an octahedral coordination environment for the nickel(II) ion, formed by the six nitrogen donor atoms, and is either a delta (clockwise) or a lambda (anticlockwise) enantiomorph, depending on the screw arrangement of the tripod-type ligand around the nickel(II) ion. The circular dichroism (CD) spectrum of a powdered sample of a crystal of 1 showed a positive and a negative peak at 915 and 630 nm, respectively, and that of another crystal showed an enantiomeric pattern. The observation of the Cotton effect and the crystal structure provided evidence for spontaneous resolution of the chiral complex molecule.

Journal Article↗
PubMed1998

Ferritin subunits in sera and synovial fluids from patients with rheumatoid arthritis.

OBJECTIVE: To determine the proportion of glycosylated ferritin [ferritin bound to concanavalin A (Con-A)] and ferritin subunits in sera and synovial fluids (SF) from patients with rheumatoid arthritis (RA). METHODS: Ferritin concentrations were measured by a sandwich ELISA using rabbit IgG F(ab')2 anti-human ferritin antibody as a coating antibody. Proportions of glycosylated ferritin were examined using Con-A Sepharose 4B. Ferritin subunits were tested by Western blot analysis. RESULTS: Ferritin concentrations in RA SF were significantly elevated compared to those in osteoarthritis (OA) SF (p < 0.01) and those in RA sera (p < 0.01). Percentages of glycosylated ferritin in SF were low in both RA and OA (RA 11.9 +/- 10.7, n = 41; OA 6.9 +/- 11.0, n = 10). However, percentages of glycosylated ferritin in RA sera (65.9 +/- 15.0, n = 20) were significantly higher than in RA SF (p < 0.01). Western blot analysis revealed both G subunit (23 kDa) and L subunit ( 19 kDa) in RA sera, although SF ferritin was composed mostly of L subunit. CONCLUSION: Significant differences in ferritin molecule composition were observed between sera and SF from patients with RA, which suggests that in RA most SF ferritin is synthesized locally in the affected joint.

Adult↗
PubMed1984

Pathogenetic difference between collagen arthritis and adjuvant arthritis.

Daily treatment with cyclosporin at a dose of 25 mg/kg for 14 d gave complete suppression of the development of collagen arthritis and adjuvant arthritis in Sprague-Dawley rats during an observation period of 45 d. To study whether the immunologic unresponsiveness produced by cyclosporin is antigen specific, we rechallenged the cyclosporin-protected rats with either type II collagen or complete Freund's adjuvant (CFA) after discontinuation of cyclosporin treatment. Type II collagen-immunized, cyclosporin-protected rats did not develop arthritis in response to reimmunization with type II collagen, but, they did develop arthritis in response to a subsequent injection of CFA. Similarly, CFA-injected, cyclosporin-protected rats showed a suppressed arthritogenic reaction in response to reinjection of CFA, whereas their response to a subsequent immunization with type II collagen was unaffected. On the other hand, the rats that were treated with cyclosporin without any prior antigenic challenge could develop arthritis in response to a subsequent injection of CFA or type II collagen after cessation of cyclosporin treatment. These results indicate that specific immunologic unresponsiveness can be induced by cyclosporin in the two experimental models of polyarthritis, collagen arthritis and adjuvant arthritis, and that there is no cross-reactivity between type II collagen and the mycobacterial cell wall components. The results further indicate that immunity to type II collagen plays a critical role in the pathogenesis of collagen arthritis but that its pathogenetic role in adjuvant arthritis is insignificant.

Animals↗
PubMed1983

Paradoxical effects of cyclosporin A on collagen arthritis in rats.

The effect of the immunosuppressive agent cyclosporin A (CS-A) on collagen arthritis in Sprague-Dawley rats is investigated. A 14-d course of CS-A treatment at doses of 15 mg/kg per day or more, begun on the same day as type II collagen immunization, suppressed the development of arthritis as well as humoral and delayed-type hypersensitivity (DTH) skin test responses to type II collagen, possibly by interfering with helper T cells. Additional studies demonstrated that CS-A treatment only during the induction phase of immunity proved to be successful. When CS-A treatment was started only during the immediately preclinical phase of arthritis or after the disease onset, a significant enhancement of the disease was obtained in a dose-dependent manner. This enhancement was accompanied by an augmentation of DTH skin reactions, while antibody responses were either suppressed or unaffected. These results appear to be attributable at least in part to a suppressive effect of CS-A on a population of suppressor T cells, thus resulting in a T cell-mediated helper effect. It is therefore reasonable to assume that the paradoxical effects of CS-A on collagen arthritis in rats might be caused by an altering of the sensitive balance of the two regulatory subpopulations of T cells. It is also possible that cell-mediated immune responses may play an important role in influencing the course of the disease.

Animals↗
PubMed1983

Spondyloepiphyseal dysplasia tarda with progressive arthropathy.

The clinical and roentgenographic manifestations of six cases suffering from spondyloepiphyseal dysplasia tarda with progressive arthropathy are presented. The roentgenographic features consist of generalized platyspondyly and varying degrees of epiphyseal involvement with conspicuous enlargement of both ends of the short tubular bones of the hands. This disorder appears at an earlier age, and is more crippling than the usual form of spondyloepiphyseal dysplasia tarda. It is suggested that orthopaedic measures are essential for all patients with this disorder, as profound disability may be expected by progressive involvement of the major joints.

Adolescent↗
PubMed1983

Hurler-Scheie phenotype with parental consanguinity. Report of an additional case supporting the concept of genetic heterogeneity.

The Hurler-Scheie phenotype in a 27-year-old woman of first-cousin parentage is possibly the first reported in the orthopedic literature. The patient exhibited short stature, coarse facies, corneal clouding, multiple stiff joints, normal intelligence, and a long history of bilateral carpal tunnel syndrome, which has not been relieved after operation. The irreversible nerve damage was apparently produced by the marked thickening of the transverse carpal ligament. Surgical findings in this case and data from published reports emphasize the need for early surgical treatment of the associated carpal tunnel syndrome in patients with the Hurler-Scheie phenotype. Parental consanguinity present in this patient is further evidence supporting the concept of a third mutant allele different from both the Hurler gene and the Scheie gene.

Adult↗
PubMed1982

Generalized enchondromatosis with unusual complications of soft tissue calcifications and hemangiomas. Follow-up for over a twelve-year period.

Generalized enchondromatosis is a newly delineated type of enchondromatosis. Radiographically there are multiple enchondromata in almost all metaphyses of the long and short tubular bones and the lesions are in almost the same stage of development with mild platyspondyly and skull deformity. The pelvic changes are characteristic and, together with the metaphyseal changes of the long and short tubular bones, are probably diagnostic of this disorder. The present case demonstrates advanced radiographic features of this disorder associated with unusual soft tissue calcifications and hemangiomas. The presence of hemangiomas in our case as well as three cases in the literature suggests this feature is more than a coincidence.

Bone Neoplasms↗
PubMed1982

Intermediate form of osteopetrosis with recessive inheritance.

The clinical and radiographic features of the intermediate form of osteopetrosis in two sibs are presented in which the disorder appears to have been inherited as a recessive trait. Although this form of osteopetrosis has been poorly delineated, its recognition is practically important in order to give an accurate prognosis. This paper also presents an unusual complication of bilateral avascular necrosis of the femoral head in the younger sib. Radiographic changes of the femoral heads suggest those of Legg-Calvé-Perthes disease, though the possibility of avascular necrosis following unrecognized femoral neck fracture is not completely excluded.

Adolescent↗
PubMed1982

Transtrochanteric rotational osteotomy of the femoral head for the treatment of osteonecrosis. Follow-up statistics.

Transtrochanteric rotational osteotomy of the femoral head was technically established as a surgical procedure in 1972. This procedure has been successfully performed on 250 hips in 204 patients. In the treatment of idiopathic and steroid-induced osteonecrosis of the femoral head, the results of 128 hips in 90 patients followed two to nine years were reviewed. In 98 of 128 hips, excellent results were obtained clinically and roentgenographically. Progressive collapse in the newly created weight-bearing area occurred in 25 hips where the lesions had been extensive. In 35 of 39 Grade I or II hips, excellent results were obtained in every respect (success rate: 90%). Following the analysis of results on the preoperative lateral roentgenograms of the femoral head, 76 of the 80 hips in the group in which the intact area was greater than one third of the total articular surface showed no collapse of the newly created weight-bearing area, thus accounting for a 95% success rate. In cases when a further collapse was prevented, the necrotic lesions were smaller at follow-up. Excellent results were obtained when the osteotomy was performed during the early stage of necrosis and in the absence of an advanced collapse, even in extensive lesions. In advanced cases with an extensive lesion, adequate anterior rotation is essential and intentional varus position should be designed. These results suggest that this procedure will inhibit progressive collapse of the femoral head and restore the joint more effectively than other surgical procedures.

Femur Head Necrosis↗
PubMed1981

Phalangeal microgeodic syndrome in childhood: report of seven cases and review of the literature.

Seven cases of phalangeal microgeodic syndrome in childhood are reported. Reviewing the literature, we have found a total of thirty Japanese cases, including the cases of our own. On the other hand, only ten cases have been reported outside Japan. The mean age of onset of the Japanese was six and a half years, which is older than that in the initial description. Of further interest is the fact all the cases in Japan occurred sporadically and exclusively in winter, and regressed spontaneously and fairly rapidly within six months. Furthermore, most of the cases reported in Europe also occurred in the winter months. These facts imply an etiological relationship between the lowered temperature and the bone lesions.

Bone Diseases↗