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Biomedical subjects

K Yonemoto

Publications and source records attributed to K Yonemoto.

At least 19 recordsLinked to original sources
PubMed2006

Decreasing incidence of lacunar vs other types of cerebral infarction in a Japanese population.

BACKGROUND: There is scant information on secular trends in the incidence and survival of ischemic stroke subtypes. METHODS: The authors established three cohorts of Hisayama residents age > or =40 years in 1961 (1,618 subjects), 1974 (2,038 subjects), and 1988 (2,637 subjects). They followed up with each cohort for 12 years, comparing the incidence and survival rate of ischemic stroke subtypes. Morphologic examinations by autopsy or brain imaging was performed on most of the ischemic stroke cases in all cohorts. RESULTS: The age-standardized incidence of lacunar infarction significantly declined by 59% for men and by 28% for women from the first to the second cohort. It continued to decline by 41% for men, but the decline decelerated for women between the second and third cohort. The age-standardized incidence of atherothrombotic infarction tended to decline from the first to the second cohort, whereas it was sustained between the second and third cohort for both sexes. The age-standardized incidence of cardioembolic infarction was unchanged throughout the cohorts. In these cohorts, mean blood pressure levels among hypertensive subjects and the prevalence of current smoker decreased with time, though the prevalence of hypertension remained stable. The 5-year survival rate after lacunar infarction significantly improved among the cohorts, but those of atherothrombotic and cardioembolic infarction did not. CONCLUSIONS: These data suggest that, in the Japanese population, the incidence of lacunar infarction steadily declined for the last 40 years. The improvement of hypertension control and decreasing prevalence of smoking might be responsible for this trend.

Adult↗
PubMed2001

Cricoarytenoid arthritis with rheumatoid arthritis and systemic lupus erythematosus.

A 56-year-old woman with rheumatoid arthritis (RA) suddenly developed severe respiratory distress and laryngeal stridor, which required endotracheal intubation. She had had RA for 12 years, which had been controlled well with prednisolone (3 mg/day) at the orthopedic clinic. Laryngoscopy revealed cricoarytenoid arthritis. She was finally diagnosed as having overlap syndrome with RA and systemic lupus erythematosus. She was given high dose corticosteroids that improved her clinical symptoms and laryngoscopic findings. She represents the first patient with overlap syndrome who developed an acute airway obstruction due to cricoarytenoid arthritis.

Arthritis, Rheumatoid↗
PubMed2001

CD56-Positive cutaneous lymphoma with multicentric Castleman's disease-like systemic manifestations.

We report a 55-year-old Japanese male with CD56+ cutaneous lymphoma. The patient had multiple cervical lymphadenopathy, a red nodule on his neck, and parotid gland nodularity. Histologic features of the biopsied cervical lymph node showed follicular hyperplasia with numerous plasma cells. A biopsied skin specimen of the nodule on his neck demonstrated dense infiltration of atypical large lymphocytes into the dermis. Immunohistochemical study of this specimen revealed CD3+, CD4+, and CD56+ expression in the majority of neoplastic cells. Polymerase chain reaction assays for the detection of Epstein-Barr virus sequences were positive for lymph node and skin DNA. Laboratory examinations showed polyclonal gammopathy, pancytopenia, and high serum interleukin-6 levels. These clinical and histological findings resembled those of multicentric Castleman's disease.

CD56 Antigen↗
PubMed2000

Diffuse large B-cell lymphoma associated with skin, muscle and cranial nerve involvement.

The present case, a 75-year-old man with extranodal B-cell lymphoma showed facial hemiplegia, paresthesia and cutaneous manifestations. He was initially diagnosed as having a facial paralysis of unknown etiology. One month after the original diagnosis, erythematous indurated plaques developed on his left cheek and nose. A skin biopsy from the plaque on his cheek showed dense infiltrates of large lymphocytes with irregularly shaped nuclei and prominent nucleoli in the dermis and subcutaneous tissue. The lymphocytes were positive for L26 and CD79a. A diagnosis of diffuse large B-cell lymphoma was made. A muscle biopsy from facial muscle in the area of the erythematous plaque showed massive destruction of the muscle tissues by the lymphomatous infiltrates. Furthermore, electrodiagnostic study showed peripheral cranial nerve palsies, involving the left facial and trigeminal nerves. We conclude that diffuse large B-cell lymphoma may develop symptoms such as facial hemiplegia and paresthesia prior to cutaneous manifestations. Diffuse large B-cell lymphoma must be considered as one of the important causes of palsies of cranial nerves at the peripheral level.

Aged↗
PubMed1998

Silent nucleotide substitution in the sterol 27-hydroxylase gene (CYP 27) leads to alternative pre-mRNA splicing by activating a cryptic 5' splice site at the mutant codon in cerebrotendinous xanthomatosis patients.

A functionally silent nucleotide substitution of the sterol 27-hydroxylase gene (CYP 27), identified in two families with cerebrotendinous xanthomatosis (CTX), was confirmed to cause alternative pre-mRNA splicing of the gene. Full-length RT-PCR analysis of the CYP 27 gene in a patient from one of the CTX families revealed one major and an additional faint band. Sequence analysis of the cloned RT-PCR product showed three species of cDNA: 3' terminal 13 bp of exon 2 deleted cDNA, exon 2 skipped cDNA, and full-length cDNA with a functionally silent G to T mutation at codon 112 (GGG 112Gly to GGT 112Gly). Only a single base change was identified by genomic DNA sequence analysis of the CYP 27 gene in the patient: T replaced G at the third position of codon 112, 13 bp upstream from the 3' terminus of exon 2. Transfection of constructed minigenes, with or without the mutation, confirmed that this silent mutation resulted in alternative pre-mRNA splicing by activating a cryptic 5' splice site around the mutant codon. The mutation was also identified in two patients from another CTX family, with a compound heterozygous pattern of A for G substitution at codon 372, a mutation reported previously by our group. The results elucidate a novel molecular basis for the CTX and suggest the significance of a silent nucleotide substitution with regard to pre-RNA splicing.

Alternative Splicing↗
PubMed1997

Genomic organization and alternative splicing of human PACE4 (SPC4), kexin-like processing endoprotease.

PACE4 (paired basic amino acid cleaving enzyme) is a member of a family of the mammalian kexin-like proprotein convertases containing a subtilisin-like catalytic domain. Previously we reported seven isoform mRNAs of PACE4 that vary in size and 3'-coding sequence [A. Tsuji et al. (1994) Biochem. Biophys. Res. Commun. 200, 943-950; K. Mori et al. (1997) J. Biochem. 121, 941-948]. To determine the origin of these isoforms, the entire human PACE4 gene has been isolated as a set of overlapping genomic DNA fragments, and analyzed by restriction enzyme digestion and nucleotide sequence determination. The human PACE4 gene spans at least 250 kb and is distributed over 25 exons that range in size from 39 to 1,422 base pairs. Human PACE4 gene is the largest kexin-like proprotein convertase gene reported to date. The most striking feature of its genomic structure is the size of the introns and the number of exons, although the general organization of signal peptide, propeptide, and catalytic domains, which are conserved in this family, is very similar to that reported for other kexin-like protease genes. The structural analysis of PACE4 genomic DNA indicates that multiple PACE4 transcripts are produced as a consequence of alternative RNA splicing events, including exon skipping, and differences in the usage of the inner 5'-splicing donor and polyadenylation sites. A major transcriptional start site was detected 314 bp upstream from the ATG translational start site by primer extension analysis. Sequence analysis of the 5'-flanking region revealed that PACE4 gene lacks TATA and CCAAT boxes in the proximal upstream region of the start site, although potential binding sites for several transcription factors including SP1, AP1, AP2, PEA3, Ets-1, GHF (growth hormone factor)-1, CREB (cyclic AMP response element binding protein), and basic helix-loop-helix proteins, were present. An unusual sequence of six tandem repeats of a nonadecamer (GGCCTGGGGGTTCACCTGC) containing an E box is found in the 5'-flanking region. These results suggest that PACE4 is not a constitutive gene product and its expression is regulated by various transcription factors.

Alternative Splicing↗
PubMed1996

Inhibitory effect of magnesium L-ascorbyl-2-phosphate (VC-PMG) on melanogenesis in vitro and in vivo.

BACKGROUND: An inhibitory effect of ascorbic acid (AsA) on melanogenesis has been described. However, AsA is quickly oxidized and decomposed in aqueous solution and thus is not generally useful as a depigmenting agent. OBJECTIVE: Our purpose was to examine the effect on pigmentation of magnesium-L-ascorbyl-2-phosphate (VC-PMG), a stable derivative of AsA. METHODS: Percutaneous absorption of VC-PMG was examined in dermatomed human skin, and its effect on melanin production by mammalian tyrosinase and human melanoma cells in culture was also measured. A 10% VC-PMG cream was applied to the patients. RESULTS: VC-PMG suppressed melanin formation by tyrosinase and melanoma cells. In situ experiments demonstrated that VC-PMG cream was absorbed into the epidermis and that 1.6% remained 48 hours after application. The lightening effect was significant in 19 of 34 patients with chloasma or senile freckles and in 3 of 25 patients with normal skin. CONCLUSION: VC-PMG is effective in reducing skin hyperpigmentation in some patients.

Ascorbic Acid↗
PubMed1996

Bowen's disease: statistical study of a 10 year period.

According to histological records, a total of 74 patients were diagnosed with Bowen's disease (B.d.) between 1 January 1984 and 31 December 1993 at the Department of Dermatology of Kitasato University. There was slight female predominance (36 male, 38 female), and 73% of the patients were older than 60 years; the mean age was 66.8 years. Fifteen patients had multiple (two-five) lesions. In 13 patients, other benign skin lesions were also found. Arsenic exposure as etiologic factor could have been present in 2 cases. Only 3 patients had other associated malignant tumors, which does not confirm the paraneoplastic nature of B.d. One-fifth of the lesions were on sun-exposed areas (head, neck and hands). Although we excluded invasive carcinomas from our statistical study, we mention the 8 invasive carcinomas developing from B.d. in that period. Histopathological classification of B.d. is uncommon. Classifying our cases by Darier's histopathological classification, 63.3% of them belonged to the lenticular type. The malignant potential of different histopathological types of B.d. needs further investigation.

Adult↗
PubMed1992

Histological examination of surface repair tissue after successful osteotomy for osteoarthritis of the hip joint.

In this study biopsy specimens of the surface repair tissue from the weightbearing area of the hip joint were collected from 15 patients who had undergone successful valgus osteotomy, and these were examined histologically. In 6 of the 15 patients the specimens stained strongly with safranin-O in all three layers of the matrix. However, the repair tissue from another 6 patients showed strong staining only in the intermediate and deep layers, while that from 2 patients stained only in the deep layer. Specimens from 5 patients were stained for S-100 protein and positive cells were detected in all cases, demonstrating that the cells in the repair tissue were chondrocytes. However, there was no tide mark in the repair tissue and the arrangement of the cells differed from that in normal cartilage. Discontinuity of the subchondral bone was also noted. These findings make it likely that the repair tissue was of bone marrow origin.

Adult↗
PubMed1992

Lichen planus annularis: an immunohistochemical study.

Lichen planus annularis is a relatively rare skin manifestation of lichen planus. The mechanisms in the formation of annular lesions are not fully understood. We reported here a 57-year-old female with this disease. The eruption initially occurred as lichen-papules, then enlarged (bean-sized, umbilicated small plaques), and finally developed annular manifestations. We performed immunohistochemical examinations of specimens taken from different types of eruptions. In all specimens, HLA-DR was expressed in the focal keratinocytes adjacent to the dermal HLA-DR positive cell infiltration. Both in the initial papule and in the final annular lesion, expression of ICAM-1 was present only in the keratinocytes above the dermal cell infiltration, similar to HLA-DR. It is of interest that, in the umbilicated small plaques, the peripheral epidermis other than the central site extensively reacted to ICAM-1. LFA-1 expression was most prominent in the mononuclear cells impinging on the dermo-epidermal junction in all specimens. In addition, in the periphery of the umbilicated small plaques, which showed no bandlike dense cell infiltration nor degeneration of basement membrane, TNF-alpha, but not LFA-1, was positive in the infiltrated cells of the upper dermis. These results suggest that expressions of ICAM-1 and TNF-alpha in the peripheral keratinocytes and dermal infiltrated cells are important molecular events in the mechanisms of formation of the annular lesions.

Antigens, CD↗
PubMed1992

Radiological evaluation on allograft reconstruction of the acetabulum combined with supporting device in revision total hip replacement.

We reviewed the radiographs of 25 hips of 20 patients who had received revisions of the acetabular components of total hip replacement supplemented by allograft for bone defects. Bone defects in 20 hips (80%) were classified into type D (cranio-central defect) according to Itoman's classification. In eight, sockets were installed directly on the allografts (group A). A metallic supporting device was used for reinforcing the grafts in 17 hips (group B). The position of the acetabular socket was measured on a radiograph, taken immediately after revision surgery and again at the latest follow-up. Using a MEM template, cranial and central migrations were determined. Mean cranial migration in hips of group A was 3.6 mm. Group B was 0.2 mm. Maintenance of thickness of the allografts was 60.6% in the cranial region and 75% in the central in group A. In the hips of group B, however, almost 100% of the initial thickness was maintained cranially and centrally. Allograft reconstruction of acetabular bone defect in revision total hip replacement is a beneficial procedure. The remaining pelvic bone is usually in poor condition, therefore, it is necessary to ensure primary fixation by the metallic supporting device.

Acetabulum↗
PubMed1992

Valgus-flexion osteotomy for middle-aged patients with advanced osteoarthritis of the hip: a clinical and radiological evaluation.

We followed up 34 secondary osteoarthritis patients with 38 hips treated by valgus-flexion osteotomy between 1979 and 1985. The average age of the patients at surgery was 45 years and the follow-up period ranged from 5 to 11 years. After surgery, the clinical evaluations were made according to the JOA Hip Score which remained unchanged in all 38 hips for 5 years. After 6 years there were some hips whose score declined with time. It was found that the preoperative extension-flexion range was the factor that was most closely associated with the result of the surgery (p less than 0.01). Radiological examination at 5 years revealed that the joint space had been widely broadened and the trabecular structure nearly normalized in 23 hips (60.5%), while 15 hips (39.5%) showed a slight degree of joint space broadening and were left with sclerosis and pseudocysts. After a lapse of 10 years or more, in 13 hips out of 10 patients, seven were found to have osteoarthritic changes and revision had to be done by THR in 2 patients. Valgus-flexion osteotomy can therefore be said to provide one of the useful means to preserve joints when employed in middle-aged patients with secondary OA.

Adult↗
PubMed1990

Effects of deoxyspergualin on collagen arthritis in mice.

We have studied the effect of the immunosuppressive agent deoxyspergualin (DSG) on collagen arthritis in mice. DSG, when given prophylactically, was capable of suppressing the development of collagen arthritis in mice as well as the immunological response to native type II collagen in a dose-dependent manner. Further, treatment of DSG, started 7 days after the primary immunization, also resulted in the inhibition of development of arthritis and immunity to collagen. The treatment of DSG, started after a booster injection, did not suppress the development of arthritis, despite suppression of antibody production in collagen. These findings suggest the possibility that a threshold level of anti-type II collagen antibodies may exist which must be exceeded before arthritis develops. Its therapeutic use in mice did not affect the clinical course of arthritis or the immune response to collagen, which is similar to the results obtained with cyclosporin.

Animals↗