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Biomedical subjects

S Maki

Publications and source records attributed to S Maki.

At least 55 records · Page 3Linked to original sources

Scoliosis and congenital heart disease.

STUDY DESIGN: This study analyzed clinical characteristics of scoliosis associated with congenital heart disease. Chest roentgenograms were reviewed to determine frequency, type, onset, and progression of scoliosis associated with congenital heart disease. OBJECTIVES: To determine which patients with scoliosis and congenital heart disease should be followed-up carefully. SUMMARY OF BACKGROUND DATA: Although several studies have been reported on scoliosis and congenital heart disease, the etiology of scoliosis in patients with congenital heart disease is still unknown. Furthermore, it has been difficult to determine the progression of scoliosis. METHODS: Chest roentgenograms of 680 patients who underwent cardiac operations because of congenital heart disease were evaluated. RESULTS: Seventy-four (10.9%) of these patients had scoliosis of more than 10 degrees, although most of them had mild curves. Scoliosis in patients under 10 years old undergoing cardiac operations was more severe than in those older than 10 years who underwent surgery. Scoliosis associated with congenital heart disease showed no particular features. Patients with patent ductus arteriosus showed left convex, high thoracic scoliosis after surgery. CONCLUSIONS: The mechanisms of onset of scoliosis in patients with congenital heart disease were not simple and were affected by several factors, including age at operation, side of approach, and type of congenital heart disease.

Adolescent↗

Molecular organization of Chlorella vulgaris chromosome I: presence of telomeric repeats that are conserved in higher plants.

The unicellular green alga Chlorella vulgaris (strain C-169) has a small genome (38.8 Mb) consisting of 16 chromosomes, which can be easily separated by CHEF gel electrophoresis. We have isolated and characterized the smallest chromosome (chromosome I, 980 kb) to elucidate the fundamental molecular organization of a plant-type chromosome. Restriction mapping and sequence analyses revealed that the telomeres of this chromosome consist of 5'-TTTAGGG repeats running from the centromere towards the termini; this sequence is identical to those reported for several higher plants. This sequence is reiterated approximately 70 times at both termini, although individual clones exhibited microheterogeneity in both sequence and copy number of the repeats. Subtelomeric sequences proximal to the termini were totally different from each other: on the left arm, unique sequence elements (14-20 bp) which were specific to chromosome I, form a repeat array of 1.7 kb, whereas a 1.0 kb sequence on the right arm contained a poly(A)-associated element immediately next to the telomeric repeats. This element is repeated several times on chromosome I and many times on all the other chromosomes of this organism.

Base Sequence↗

Isolation and characterization of a kettin-like protein from crayfish claw muscle.

A 540 kDa protein was isolated from crayfish claw muscle (closer). The secondary structure mainly consisted of beta-sheet (70%). The rotary shadowed images were long filaments, 300-360 nm long. It is localized in the sides of the Z-lines extending to the I band and elongatable upon stretch of muscle. Immunological crossreactivities strongly suggested that this protein corresponds to kettin (500-700 kDa) of insect striated muscle. In view of molecular shape and secondary structure, and immunological crossreactivities, it is suggested that this kettin-like protein belongs to connectin/titin family of striated muscle.

Actins↗

Relation of emotional behaviors to urine catecholamines and cortisol.

We examined changes of epinephrine, norepinephrine, and cortisol levels in 24-h urine accompanying emotional behavior in cats such as restlessness, threat, and quiet biting attack elicited by electrical stimulation of specific sites within the hypothalamus. Although norepinephrine remained unchanged with restlessness but increased with threat, elevation of epinephrine and cortisol levels was common to restlessness and threat. No significant changes in these hormonal levels were seen with quiet biting attack and control. Therefore, it was suggested that emotional behaviors such as restlessness and threat are more closely related to emotional stress than quiet biting attack in cats.

Animals↗

Clinical results of the one-bone forearm.

Between 1973 and 1991, 19 patients underwent creation of a one-bone forearm at our institution as treatment for radioulnar instability secondary to trauma ("type 1" patients) or tumor resection or congenital deformity ("type 2" patients). Seventeen had failed previous reconstruction attempts. Ten one-bone forearms were constructed in neutral rotation, and nine in varying pronation (mean, 24 degrees). The distal ulna was absent or excised at the time of surgery in nine patients, partially excised in two, and shortened in one. At a mean follow-up interval of 42 months, the primary union rate was 68%, and the secondary rate was 74%. Using a rating scale devised for this study, 37% excellent, 32% good, 26% fair, and 5% poor results were noted. Poor results were statistically associated with previous trauma (type 1 patients), infection, severe nerve injury, and multiple previous surgical procedures. This is a retrospective study, and because of the limitations of such studies, no correlation of results with forearm rotational position, preoperative wrist or elbow dysfunction, fusion location, distal ulna excision or synostosis union was noted. Significant complications were noted in 10 patients, with a higher rate in type 1 patients. Although one-bone forearm construction remains a viable salvage option for forearm instability in selected patients, results may be less predictable than previously reported.

Adult↗

Reliability of the task-related component (P3b) of P3 event-related potentials.

Within session and between session reliabilities of the task-related component (P3b) of the P3 measures (amplitude, area and latency) and their habituation across eight sessions separated by 7-10 days, except for an interval of 1 month between the 6th and 7th sessions, were studied based on the difference waves, which were obtained by subtracting the ignored infrequent event-related potentials (ERP) from the target ERP elicited by a standard auditory oddball paradigm with eyes-open or eyes-closed conditions in 10 normal subjects. The within session reliabilities represented as Pearson correlation coefficients (r) were 0.57-0.66 for the three measures except for those for the latency and amplitude under the eyes-closed condition. The between session reliabilities expressed as intraclass correlation coefficients (R) ranged from 0.54 to 0.60 except for that for latency under eyes-closed conditions. Long-term habituation occurred within the first six sessions for the P3b amplitude and area, and dishabituation took place in the 7th session after an interval of 1 month, whereas no such phenomenon was observed for the P3b latency. Implications of the present results are discussed in terms of the clinical application of the P3 measures.

Adult↗

Human IgA nephritis: immunocytochemical evidence of a chronic inflammatory proliferative disorder.

This overview summarizes recent information concerning the biopathology of mesangial cell proliferation and matrix expansion which constitute fundamental features in human IgA nephritis. The currently available knowledge, mainly stemming for immunohistochemical observation of human materials, experimental investigations with laboratory animals, and mesangial cell culture studies, emphasizes the importance of cell to cell, cell to soluble factors, and cell to matrix interactions. Mesangial cells, activated by cytokines and growth factors, express adhesion molecules, stimulate proliferation both of themselves and neighbouring cells, and synthesize extracellular matrix. Matrix components, in turn, may influence the behaviour and proliferation activity of mesangial cells, or act as a receptor or reservoir for growth factors. Expression of protooncogenes, regulating cell proliferation and apoptosis, by glomerular cells could be associated with persistent cell replication and chronic tissue damage. These disease processes seem to be common to a group of diseases termed chronic inflammatory proliferative disorders.

Apoptosis↗

Molecular characterization of Chlorella chromosomes: screening of bent DNAs.

As a model for plant-type chromosomes, we have been characterizing molecular organization of Chlorella vulgaris (C-169) chromosome I. To locate structurally important chromosome regions, bent DNA fragments of this chromosome were systematically obtained and analyzed. By two-dimensional polyacrylamide gel electrophoresis, 150 clones containing bent DNA fragments were screened from C. vulgaris genomic libraries. These clones were classified into 3 groups by Southern hybridization. A group that hybridized with all Chlorella chromosomes contained fragments carrying a retroposon-like element. A clone (p2DS-66A) derived from chromosome VI strongly hybridized with chromosome I as well as the others. The corresponding chromosome I sequences (pI-21 and pI-31) were analyzed in detail.

Base Sequence↗

The RFC2 gene encoding a subunit of replication factor C of Saccharomyces cerevisiae.

Replication Factor C (RF-C) of Saccharomyces cerevisiae is a complex that consists of several different polypeptides ranging from 120- to 37 kDa (Yoder and Burgers, 1991; Fien and Stillman, 1992), similar to human RF-C. We have isolated a gene, RFC2, that appears to be a component of the yeast RF-C. The RFC2 gene is located on chromosome X of S. cerevisiae and is essential for cell growth. Disruption of the RFC2 gene led to a dumbbell-shaped terminal morphology, common to mutants having a defect in chromosomal DNA replication. The steady-state levels of RFC2 mRNA fluctuated less during the cell cycle than other genes involved in DNA replication. Nucleotide sequence of the gene revealed an open reading frame corresponding to a polypeptide with a calculated Mr of 39,716 and a high degree of amino acid sequence homology to the 37-kDa subunit of human RF-C. Polyclonal antibodies against bacterially expressed Rfc2 protein specifically reduced RF-C activity in the RF-C-dependent reaction catalyzed by yeast DNA polymerase III. Furthermore, the Rfc2 protein was copurified with RF-C activity throughout RF-C purification. These results strongly suggest that the RFC2 gene product is a component of yeast RF-C. The bacterially expressed Rfc2 protein preferentially bound to primed single-strand DNA and weakly to ATP.

Amino Acid Sequence↗

Cellular localization of inflammatory cytokines in human glomerulonephritis.

We evaluated the expression of inflammatory cytokines in renal tissues obtained from 45 patients with several types of glomerulonephritis. Immunofluorescence studies with specific antibodies to interleukin (IL)-1 alpha, IL-1 beta, IL-6, tumour necrosis factor (TNF)-alpha, and TNF-beta showed intense cytoplasmic staining in the glomeruli and interstitium. Cells positive for these cytokines were found frequently in tissue from patients with lupus nephritis (WHO Class IV) and membranoproliferative glomerulonephritis, and, to a lesser extent, in tissue from patients with mesangial proliferative glomerulonephritis, Henoch-Schönlein purpura nephritis, and minimal change nephrotic syndrome. Most of these cells were dual-stained with a monoclonal antibody to monocytes-macrophages. In situ hybridization for cytokine mRNA, combined with immunoperoxidase staining for monocytes-macrophages, detected IL-1 alpha, IL-6, and TNF-alpha mRNA in monocytes-macrophages infiltrating the glomeruli and interstitium. Occasionally, there was weak or moderate immunostaining for IL-1 alpha, IL-6, and TNF-alpha in the glomerular mesangial and epithelial cells, but in situ hybridization signals were rarely found in these loci. These findings suggest that infiltrating monocytes-macrophages, rather than resident glomerular cells, are the major source of inflammatory cytokines in human glomerulonephritis.

Glomerulonephritis↗

Antigenic phenotypes of Escherichia coli in urine from patients with urinary tract infections.

Various antigenic phenotypes of Escherichia coli in urine were analysed using monoclonal antibody against pyelonephritis-associated P-pili (PAP-pili), and polyvalent O- and K1-antisera, and the results were compared with the clinical diagnosis. PAP-pili, O1- and K1-positive E. coli were isolated more frequently in urine from patients with acute pyelonephritis. E. coli found in urine from patients with recurrent pyelonephritis were frequently PAP positive. Based on the antigenic phenotypes of strains in urine, it is suggested that pyelonephritopathogenic strains may originate from a small number of clones.

Acute Disease↗

Production and characterisation of monoclonal antibodies against pyelonephritis-associated P-pili of Escherichia coli.

Pyelonephritis-associated P-pili (PAP) of Escherichia coli O6,H(-),K1(-),F12,haemolysin(-) were purified by salt precipitation and affinity chromatography using Synsorb P1. Purified PAP showed a single band with a molecular weight of 18 kDa by electrophoretic analysis. A monoclonal antibody (mAb) was produced by fusion of the PAI myeloma cell line with splenic lymphocytes from BALB/c mice immunised with the purified PAP. The mAb was of IgM class with kappa light chains and reacted with a 18-kDa moeity of the salt precipitate; the epitope was present near the apical part of the pilus filaments. The mAb reacted with PAP in both immunofluorescence and haemagglutination tests when 108 strains isolated from urine samples were tested; the two tests were in agreement for 202 of 204 strains isolated from faecal samples.

Animals↗

Transient erythroblastopenia due to human parvovirus B19 infection: a case report of a boy suffering from purpura.

Transient erythroblastopenia of childhood (TEC) was observed in a boy infected by human parvovirus B19 (B19) before the manifestation of the typical clinical picture of erythema infectiosum (EI). He did not have any apparent symptoms of anemia, and spontaneous resolution of erythroblastopenia was observed before the manifestation of the symptoms of EI. The difference between primary B19 infection and classical TEC is discussed.

Child↗

The target antigen of anti-tubular basement membrane antibody-mediated interstitial nephritis.

Our previous studies showed that 54 kD and 48 kD tubular basement membrane (TBM) proteins were the major form of the target antigen involved in anti-TBM antibody-mediated tubulo-interstitial nephritis in humans. In those studies, we isolated the 54 kD glycoprotein (named gp54) from collagenase-digested bovine TBM. NH2-terminal amino acid sequencing indicated that gp54 represented a newly defined glycoprotein. In this study, we further characterized the target antigen, using mouse monoclonal antibodies to gp54 and polyclonal anti-gp54 peptide antibody. Two monoclonal antibodies (H79 and H80) were established, and they reacted, by immunofluorescence, predominantly with the proximal TBM of humans, rabbits, and Wistar, Sprague-Dawley, and Brown-Norway rats, but not with that of Lewis rats. They were also fixed by blotting intensely to the 54 kD component and weakly to the 48 kD component of collagenase-digested human TBM. In vivo transfer of H79 to Wistar rats showed extensive linear binding of mouse IgG to the TBM and the basal membrane of the small intestine; however, no pathologic changes were seen by light microscopy. The anti-gp54 peptide antibody reacted with both the 54 kD and 48 kD TBM components of human TBM. mRNA was prepared from rabbit kidneys, and fractionated to enrich mRNA encoding the 54 kD and 48 kD peptides. On in vitro translation experiments with the mRNA fraction, the 54 kD and 48 kD peptides were immunoprecipitated with anti-gp54 antibodies. These findings indicate that the 54 kD and 48 kD components are encoded with different mRNA, but that they share the same antigenic epitope.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

Combined therapy in children and adolescents with IgA nephropathy.

We retrospectively evaluated renal outcome in a total of 38 children and adolescents with IgA nephropathy who were selected for 6-month therapy for clinical (proteinuria > 1 g/m2/24 hour) and pathologic (mesangial proliferation, crescent formation, and tubulo-interstitial changes) features suggestive of progressive renal failure. Seventeen patients (group A) were treated with a combination of prednisolone, cyclophosphamide and dipyridamole, and the remaining patients (21; group B) were treated with the same drugs plus warfarin. All the patients were followed-up for more than 2 years (range 2-10 years, mean 4.8). In both groups, the mean urinary protein excretion value was significantly reduced after the therapy, compared with that at entry into the therapy. The significant reduction continued for up to 6 years in group A and up to 5 years in group B. Creatinine clearance was stable until 5-6 years after the trial in both groups, but 4 patients progressed to end-stage renal failure after that period. Post-therapy biopsy was performed in 14 patients, and was compared with the pre-therapy biopsy. The activity score had improved in both groups, but the chronicity score did not. These results indicate that there was a temporary effect and limited benefit with this treatment of combined drugs for children and adolescents with IgA nephropathy. The additive effect of warfarin was not substantiated.

Adolescent↗

Type IV collagen alpha 5 chain. Normal distribution and abnormalities in X-linked Alport syndrome revealed by monoclonal antibody.

Although the evidence indicates that mutation of the gene for the alpha 5 chain of type IV collagen, alpha 5-(IV), is the primary defect in X-linked Alport syndrome, protein data for the alpha 5(IV) chain with regard to its normal distribution and its distribution in patients with Alport syndrome is lacking. We produced a rat monoclonal antibody (H51) by immunizing rats with a synthetic peptide corresponding to the nonconsensus amino acid sequence of alpha 5(IV) NC1 domain. H51 reacted by Western blotting with 26-kd cationic monomers and associated dimers of human type IV collagen NC1 domain. Immunohistochemical studies demonstrated that in normal human kidney alpha 5(IV) was present in the glomerular basement membrane and basement membranes of the Bowman's capsule and in some tubules (collecting ducts). The alpha 5(IV) chain was also detected in the basement membranes of normal skin, eye, and lung. Male patients with X-linked Alport syndrome revealed no reactivity of renal and epidermal basement membranes with H51, whereas alpha 5(IV) staining was normal in the glomerular basement membrane of patients with other types of glomerular diseases, including benign familial hematuria. The staining was also normal in the skin of nonaffected males in X-linked Alport families. Female heterozygous for Alport syndrome exhibited a discontinuous or mosaic pattern in the immunofluorescent staining of the epidermal basement membrane. These findings confirm that in patients with X-linked Alport syndrome there are abnormalities in alpha 5(IV) in renal and epidermal basement membranes at the protein level. Immunofluorescent staining of skin biopsies with this antibody may be of value in making a diagnosis of Alport syndrome, and, furthermore, may aid in detecting carrier females in whom urinary abnormalities are often mild or silent.

Adolescent↗

Immunotactoid glomerulopathy in a child with Down syndrome.

A 9-year-old girl with Down (21-trisomy) syndrome was found to have proteinuria and microscopic haematuria at age 6 years. Proteinuria gradually increased during the next 3 years, although blood pressure and renal function remained normal. The patient exhibited no underlying systemic diseases, monoclonal gammopathy, cryoglobulinaemia or histological evidence of plasmacytoma. A percutaneous renal biopsy revealed immunotactoid glomerulopathy (fibrillary glomerulonephritis) characterized by thickening of the glomerular basement membrane, diffuse mesangial expansion and various-sized acid-Schiff-positive nodules that were intensely positive for IgG, light chains (kappa and lambda) and complement components (C3, C4, C1q) along the glomerular capillaries in the mesangium. Congo red dye and amyloid thioflavine T staining were negative. Fibrils (15-17 nm in diameter--larger than amyloid fibrils) were present in the mesangial area and within the glomerular basement membrane. We are not aware of a previous report of immunotactoid glomerulopathy and a patient with chromosomal abnormalities.

Child↗