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S Susa

Publications and source records attributed to S Susa.

At least 19 recordsLinked to original sources
PubMed2001

Neonatal-onset hereditary coproporphyria with male pseudohermaphrodism.

The appearance of hereditary coproporphyria (HCP) before puberty is very rare, and all reported cases of early-onset HCP have been in the homozygous or the compound heterozygous state. Some have been identified as harderoporphyria, which is a rare erythropoietic variant form of HCP. These conditions can be differentiated by molecular analysis because the gene abnormality responsible for harderoporphyria seems to be unique (K404E). Early-onset HCP, not harderoporphyria, is reported with a gene mutation in the heterozygous state and male pseudohermaphrodism. It was shown that adrenal gland hypofunction resulted in male pseudohermaphrodism. This case demonstrates the possibility that abnormalities of steroid metabolism influence porphyria.

Adrenal Insufficiency↗
PubMed2001

Characterization of platelet-derived growth factor-induced p38 mitogen-activated protein kinase activation in vascular smooth muscle cells.

BACKGROUND: The mitogen-activated protein (MAP) kinase super-family plays a crucial role in cell growth and differentiation and even in programmed cell death in response to diverse extracellular stimuli. The platelet-derived growth factor (PDGF)-BB is well known to promote the proliferation of vascular smooth muscle cells (VSMC) via extracellular-regulated protein kinases (ERKs), leading to the development of cardiovascular diseases. However, it has not yet been clarified whether PDGFs that include other isoforms can activate the other parallel signal transduction pathways, c-jun NH2-terminal protein kinase (JNK) and p38 MAP kinase (p38), in VSMC. In this study, we investigated the effect of PDGFs on p38 activation in cultured rat VSMC. MATERIALS AND METHODS: After stimulation by PDGFs with SB-203580 or PD-98059, the cells were solubilized, and the expressions of MAP kinases, MAP kinase kinases (MKKs), phosphorylated DNA-binding proteins, and cyclooxigenases (COXs) were examined by immunoblot analysis. RESULTS: PDGFs activated p38 phosphorylation dose-dependently, and the phosphorylations were specifically inhibited by SB-203580 but not by PD-98059. PDGFs also activated the phosphorylation of MKK 3/MKK 6 but not that of either stress-activated protein kinase/ERK kinase or JNK. PDGFs affected the activation of a cyclic AMP response-element binding protein, which was inhibited by SB-203580. However, the activating transcription factor-2 was not activated by PDGFs. Interestingly, the stimulation of PDGFs for 72 h enhanced the level of COX-2, and these levels were decreased by SB-203580. CONCLUSION: These results have clarified that PDGFs activate the p38 cascade via an MKK 3/6 pathway, independently of the ERK cascade, and subsequently regulate the level of COX-2 in rat VSMC, providing that PDGFs influence the inflammatory process in the vascular wall.

Activating Transcription Factor 2↗
PubMed2001

Platelet-derived growth factor BB-induced p38 mitogen-activated protein kinase activation causes cell growth, but not apoptosis, in vascular smooth muscle cells.

The aim of this experiment was to examine the regulation of p38 mitogen-activated protein (MAP) kinase by platelet-derived growth factor (PDGF)-BB and its biological effects on rat cultured vascular smooth muscle cells (VSMCs). VSMCs were obtained from aortae of male Wistar rats by the media explant technique. After being stimulated by PDGF-BB with or without the p38 MAP kinase-specific inhibitor, SB-203580, the cells were solubilized, and the levels of phosphorylated p38 MAP kinase were examined by immunoblot analysis. The amounts of DNA synthesis and content were measured by using [3H]-thymidine and Hoechst-33258 dye, respectively. The detection of apoptotic cells was evaluated by the TUNEL method. PDGF-BB could phosphorylate p38 MAP kinase dose-dependently, and the phosphorylation was specifically inhibited by SB-203580 in a dose-dependent manner. However, PDGF-BB did not affect the protein level of p38 MAP kinase. Both [3H]-thymidine incorporation and total cellular DNA content were increased by PDGF-BB, and these elevations were prevented by SB-203580. In contrast, PDGF-BB-stimulated VSMCs did not show apoptotic change in spite of the presence or absence of SB-203580. These results established that PDGF-BB activated p38 MAP kinase and subsequently regulated cell growth in VSMCs, providing a molecular mechanism by which p38 MAP kinase can cause the development of cardiovascular diseases, including atherosclerosis.

Animals↗
PubMed2000

Increase in serum ceruloplasmin with aging is not observed in type 2 diabetes.

Changes of serum ceruloplasmin (Cp) levels have been reported in many conditions including diabetes mellitus (DM), in which the serum Cp levels were increased. In this study, we have examined the influence of aging on serum Cp levels in normal individuals and in individuals with DM. Serum Cp levels were measured in 85 outpatients with type 2 diabetes (type 2 DM group) as well as in 71 healthy individuals (control group). All patients recruited for this study were negative for the glutamic acid decarboxylase (GAD) antibody. The subjects were sub-grouped based on their ages (<55 and 55 < or =). The serum Cp levels in the control group increased significantly with aging (r=0.325, p<0.0055), while levels in the type 2 DM group did not (r=0.091, p=0.4079). The levels in the type 2 DM group (<55) were significantly higher than those in the control group (<55) (p = 0.0029), while the Cp levels in the type 2 DM group (55 < or =) were not different from those in the control group (55 < or =) (p=0.4187). An age-related increase of serum Cp levels was observed in normal individuals, but this change was not observed in type 2 DM patients since serum Cp levels in type 2 DM patients of all ages were similar to the levels in normal elderly individuals.

Adult↗
PubMed2000

A novel mutation of the ceruloplasmin gene in a patient with heteroallelic ceruloplasmin gene mutation (HypoCPGM).

We found a novel missense mutation in the ceruloplasmin (Cp) gene in a patient with the heteroallelic Cp gene mutation (HypoCPGM). The patient was a 72-year-old woman who came to our hospital with a 1-year history of postural tremor of the hands. The diagnosis was made based on serum Cp and copper readings which were about half the normal levels, as well as MRI tests of her brain which showed characteristics for hereditary ceruloplasmin deficiency (HCD), known to be caused by the homoallelic Cp gene mutation. Polymerase chain reaction (PCR)-direct sequencing analysis of the Cp gene of the patient revealed a novel point mutation, A to T, at nucleotide position 82 in Exon 1. This mutation changes the Ile28 codon (ATT) to a Phe codon (TTT) (missense mutation). PCR-restriction analysis with restriction enzyme Tsp EI for the mutation revealed that both the patient and her son were heterozygotes for the mutation.

Aged↗
PubMed1999

Acute intermittent porphyria with central pontine myelinolysis and cortical laminar necrosis.

Acute intermittent porphyria (AIP) is an autosomal-dominant disease caused by a deficiency of porphobilinogen (PBG) deaminase. Patients with AIP present with neurological syndromes such as autonomic neuropathy, peripheral axonal neuropathy or central nervous system dysfunction. We report serial MRI of a patient with AIP who had cortical and subcortical cerebral changes. A 29-year-old woman with a 6-month history of AIP had an attack with severe hyponatraemia and generalised convulsions, treated with haem arginate and supportive therapy. MRI showed central pontine and extrapontine myelinolysis and cortical laminar necrosis. These are not common in AIP, but are likely to have been caused by rapid correction of hyponatraemia and by vasospasm, which could be induced by AIP.

Adult↗
PubMed1999

Fine structure of the human translocation protein 1 (HTP1/TLOC1) gene.

We characterized the genomic region corresponding to the human translocation protein 1 (HTP1/TLOC1) cDNA previously reported. An experiment using rapid amplification of cDNA ends revealed that the transcription initiation site was at -12 bp upstream from the translation initiation codon ATG. Using direct-sequencing PCR, we determined precise intron/exon boundaries and intron-exon composition of the gene. The gene region spanned approximately 28 kb and was composed of eight exons and seven introns. The lengths of exons and introns range from 48 to > 1707 bp and from 0.25 to 8.2 kb, respectively. The translation initiation codon and the termination codon were located in exons 1 and 8, respectively. The nucleotide sequences of the introns were also determined in the region around the intron/exon boundaries for 63 to 442 bp. All of the sequences around the intron/exon boundaries were consistent with the 5' and 3' consensus sequences for splice junctions of transcribed genes. Putative lariat sequences were identified between -28 and -64 nucleotides from the 3' splice junction for all seven introns. DNA walking experiments revealed a promoter region of 600 bp. The promoter region did not contain an apparent TATA box or a CAT box but did contain Evi-1, GATA, v-Myb, MZF1, and AP-1 binding sites--factors known as regulatory factors on expression of the gene in blood cells. Therefore, this gene may be one such gene.

Base Sequence↗
PubMed1998

Identification of a novel mutation of the CPO gene in a Japanese hereditary coproporphyria family.

Hereditary coproporphyria (HCP) is an autosomal dominant disease characterized by a deficiency of coproporphyrinogen oxidase (CPO) caused by a mutation in the CPO gene. Only 11 mutations of the gene have been reported in HCP patients. We report another mutation in a Japanese family. Polymerase chain reaction-single strand conformational polymorphism and direct sequence analyses demonstrated a C to T substitution in exon 1 of the CPO gene at nucleotide position 85, which lies in the putative presequence for targeting to mitochondria. This mutation changes the codon for glutamine to a termination codon at amino acid position 29. MaeI restriction analysis showed two other carriers in the family. The C-T mutation is located within a recently proposed putative alternative translation initiation codon (TIC-1), supporting that TIC-1 is the real TIC rather than TIC-2.

Adult↗
PubMed1998

A novel mutation of coproporphyrinogen oxidase (CPO) gene in a Japanese family.

Hereditary coproporphyria (HCP) is an autosomal dominant disease characterized by a deficiency of coproporphyrinogen oxidase (CPO). Only 11 mutations of the gene have been reported to date as the mutations responsible for HCP. We report here a novel mutation of the gene responsible for the disease in a Japanese family. Analysis of the polymerase chain reaction (PCR) amplified DNA fragments of the gene by direct-sequencing and/or cloning-based sequencing methods revealed the gene abnormality responsible for the disease. The mutation found was a single base deletion of T at nt position 526, which results in frame shift and truncation of coded protein at amino acid position 204. Screening of pre-symptomatic cases seemed to be possible by PCR restriction analysis using restriction enzyme Xcm I.

Coproporphyrinogen Oxidase↗
PubMed1998

Hyperglycemia is a factor for an increase in serum ceruloplasmin in type 2 diabetes.

OBJECTIVE: To examine if there is a correlation between high blood glucose and serum ceruloplasmin (Cp) levels. RESEARCH DESIGN AND METHODS: Serum Cp levels were measured in 637 patients with type 2 diabetes (all type 2 diabetes group). For the follow-up type 2 diabetes group, 161 patients who had not had any changes in their situation during the last year that are known to influence serum Cp levels were reexamined 1 year later. The control group was composed of 158 healthy individuals. Serum Cp and blood HbA1c levels were measured by radial immunodiffusion and high-performance liquid chromatography assays, respectively. RESULTS: Serum Cp levels in the all type 2 diabetes group were significantly higher than those in the control group (P < 0.0001), although the serum Cp levels did not correlate with the blood HbA1c levels in the all type 2 diabetes group (r = 0.055, P = 0.351). Then we evaluated those factors (delta-log Cp and delta-HbA1c) in the follow-up type 2 diabetes group to minimize changes from the genetic differences and to exclude any known factors influencing serum Cp levels. This indicated that the delta-HbA1c had a positive correlation to the delta-log Cp (r = 0.304, P < 0.0001). CONCLUSIONS: A persistent high blood glucose (namely HbA1c) is associated with an increase in serum Cp levels over 1 year.

Adult↗
PubMed1997

Identification of a human cDNA homologue to the Drosophila translocation protein 1 (Dtrp1).

In yeast, several integral membrane proteins such as Sec61p, Sec62p and Sec63p have been reported as the components involved in protein translocation across and into the endoplasmic reticulum (ER) membrane. Among them, the homologues of Sec61p have been found both in bacterias and mammals, whereas those of Sec62p or Sec63p have not. So, Sec61p seem to be the evolutionary conserved component, while Sec62p and Sec63p may not. To date, no homologues of Sec62p have been found in mammals yet. Here, we report a novel human cDNA, HTP1 (for human translocation protein 1), that encodes a protein of 399 amino acids that is 36.3% identical (64.6% similar) to Drosophila homologue of Sec62p, Drosophila translocation protein 1 (Dtrpl). Northern blot analysis showed two HTP1 transcripts of about 2.8 and 5.5 kb, which were expressed concomitantly in various human tissues such as heart, brain, placenta, liver and pancreas.

Amino Acid Sequence↗
PubMed1991

Steroid receptors in nonmalignant and malignant kidney tissue of patients with endemic (Balkan) nephropathy.

The presence, affinity, binding capacity, structure and function of receptors for estrogen (ER), progesterone (PR) and glucocorticoid (GR) were investigated in 24 autologous pairs of control and neoplastic kidney tissues of patients with endemic (Balkan) nephropathy. In control tissue, all the three steroid receptors were absent in 20.8% and present in 25.0% of samples, whereas in malignant tissues the percentage of negative samples increased to 37.5% and that of positive ones decreased to 20.8%. Ten patients had identical receptors in both, control and cancer tissues. Due to malignant transformation nine patients lost one or more receptors, while five patients acquired them. Wide ranges of values were obtained when evaluating receptor affinity (Kd) and binding capacity (N). The structure and function of steroid receptors were investigated by determining the sedimentation coefficients (S) of steroid-receptor complexes before and after the activation. The unactivated GR-complex (8 S) was detected in two of control samples only, whereas in the remaining control tissues, as well as in malignant tissues only the activated form (4 S) was found regardless of the activation. PR and ER complexes were detected at 4 S region only. These results show that in endemic nephropathy the structure of steroid receptors may be altered often in both, non malignant and malignant kidney tissue, suggesting that the analysis of receptor structure may be worthwhile for the prediction of the success of eventual hormone therapy.

Aged↗