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Biomedical subjects

M Miyazato

Publications and source records attributed to M Miyazato.

At least 19 recordsLinked to original sources

Transitional cell carcinoma of the renal pelvis forming tumor thrombus in the vena cava.

A 47-year-old man presented with a left renal incidentaloma without hematuria. The tumor was complicated by inferior vena cava (IVC) thrombus extending from Th11 to L4. A temporary IVC filter was introduced prior to surgery. A midline incision was used to perform a left radical nephrectomy and en bloc lymphadenectomy with excision of the inferior vena cava from above the level of the left renal vein to 2.5 cm above the confluence of the common iliac veins. The pathological diagnosis was invasive transitional cell carcinoma. The tumor thrombus consisted of transitional cell carcinoma that histologically invaded the walls of the IVC. He died of cancer 17 months after the operation for the liver metastases. This is the 18th case report of such a presentation in the literature.

Carcinoma, Transitional Cell↗

[Cadaveric renal transplantation for Goodpasture's syndrome: a case report].

A 19-year-old man with a history of histologically-proven Goodpasture's syndrome (hemoptysis, rapidly progressive glomerulonephritis, and positive anti-glomerular basement membrane (anti-GBM) antibody) was maintained on hemodialysis for 21 months. After steroid pulse therapy and plasmapheresis, his anti-GBM antibody disappeared. His stable condition on dialysis and a session of plasmapheresis prior to surgery allowed him to undergo cadaveric renal transplantation from a 34-year-old man. The blood type was identical (group A and Rh (+)), and there was 1 and 0 mismatch of HLA class 1 and 2, respectively. The initial immunosuppressants included cyclosporine, methylprednisolone, mizoribine, azathioprine, and anti-lymphocyte globulin (ALG). The transplanted kidney regained function on day 6 and he was free from hemodialysis. Circulating anti-GBM antibody was negative after surgery. The graft has functioned well for almost 4 years after transplantation without any episodes of renal or pulmonary complications. To the best of our knowledge, this is the first report of renal transplantation for Goodpasture's syndrome in the Japanese literature.

Adult↗

Retroperitoneoscopic heminephrectomy of the right upper collecting system emptying into an ectopic ureterocele in a 5-year-old girl: a case report.

A 5-year-old girl with a history of recurrent urinary tract infection since the age of 14 months was diagnosed as having a right duplicated urinary collecting system with the upper ureter ectopically opening in the urethra. She underwent retroperitoneoscopic heminephrectomy for a right dysplastic kidney and open ureterocelectomy and reimplantation of the refluxing lower ureter via Pfannenstiel incision. She survived the procedure without serious complications and resumed normal daily activities by day 6. To the best of our knowledge, this case is the 16th case of laparoscopic heminephrectomy for pediatric patients and the first case treated by the retroperitoneal approach in the English literature.

Child, Preschool↗

[A case of metachronous adenocarcinoma of the urinary bladder and the right upper urinary tract].

Bilateral hydronephrosis identified by a local physician brought a 65-year-old man to our hospital. Emergency percutaneous nephrostomy was bilaterally established for obstructive renal failure. After recovering renal function, the patient underwent radical cystectomy under the diagnosis of invasive bladder cancer and the construction of an ileal conduit. The pathology reported well differentiated adenocarcinoma (pT2, pL1, pV1). Five years after the surgery, gross hematuria developed. A computed tomographic scan revealed right hydronephrosis with a solid mass in the upper calyx. The urinary cytology was negative. The patient underwent right nephrectomy in May, 1999. The pathology then revealed well differentiated adenocarcinoma in the renal pelvis and ureter (pT3, pL0, pV0 and pT1, pL0, pV0, respectively). He is alive with mild chronic renal insufficiency with evidence of tumor at ten months after surgery. To our knowledge, this is the first case of metachronous adenocarcinoma of the urinary bladder and the upper urinary tract reported in the Japanese literature.

Adenocarcinoma↗

[Giant prostatic hypertrophy: a case report].

Benign prostate hypertrophy weighing more than 200 g is defined as giant prostatic hypertrophy. An 81-year-old man presented with urinary retention and underwent retropubic prostatectomy. Blood loss was 1,850 ml and he received 800 ml of autologous blood. The removed specimen weighed 267 g and pathology revealed benign hyperplasia of the prostate. We collected 32 such cases from the Japanese literature.

Aged↗

[Retroperitoneal schwannoma arising from the adrenal area: a case report].

A 67-year-old woman presented with upper abdominal pain and was found to have a suprarenal tumor by ultrasonography and CT scanning. Under a diagnosis of non-functioning adrenal tumor, we made an extraperitoneal approach via a lumbar incision and removed the tumor together with the left adrenal gland. There was minimal blood loss. The resected tumor was firm and had a yellowish-white cut surface. The lesion measured 60 x 40 x 35 mm and weighed 50 g. The pathological diagnosis was benign schwannoma, mainly of the Antoni type A. This is the 27th case of benign schwannoma in the adrenal area reported in the Japanese literature.

Adrenal Gland Neoplasms↗

[Renal transplantation for patients with systemic lupus erythematosus: report of two cases].

Renal transplantation for patients with systemic lupus erythematosus (SLE) remains controversial. We performed living-tissue related renal transplantation on a 45-year-old woman with SLE and an eight-month history of hemodialysis. We also did cadaveric renal transplantation on a 41-year-old man with SLE and a 12-year history of hemodialysis. Serological tests including tests for antinuclear antibodies and complements were negative prior to surgery and throughout the course in both cases. The latter patients survived herpes-zoster virus infection in month 6 and bacterial pneumonia in month 9 after transplantation. Neither patient experienced any rejection or relapse of lupus nephritis after the procedure, and both maintained good renal allograft functions. The recurrence of lupus nephritis is reportedly extremely rare, i.e., with a possibility rate of less than 1% in transplant patients with burnt-out SLE. To the best of our knowledge, these cases are the 27th and 28th case reports of renal transplantation for SLE patients in Japanese literature.

Adult↗

Identification of a novel splicing mutation and 1-bp deletion in the 17alpha-hydroxylase gene of Japanese patients with 17alpha-hydroxylase deficiency.

We report studies of two unrelated Japanese patients with 17alpha-hydroxylase deficiency caused by mutations of the 17alpha-hydroxylase (CYP17) gene. We amplified all eight exons of the CYP17 gene, including the exon-intron boundaries, by the polymerase chain reaction and determined their nucleotide sequences. Patient 1 had novel, compound heterozygous mutations of the CYP17 gene. One mutant allele had a guanine to thymine transversion at position +5 in the splice donor site of intron 2. This splice-site mutation caused exon 2 skipping, as shown by in vitro minigene expression analysis of an allelic construct, resulting in a frameshift and introducing a premature stop codon (TAG) 60 bp downstream from the exon 1-3 boundary. The other allele had a missense mutation of His (CAC) to Leu (CTC) at codon 373 in exon 6. These two mutations abolished the 17alpha-hydroxylase and 17,20-lyase activities. Restriction fragment length polymorphism (RFLP) analysis with a mismatch oligonucleotide showed that the patient's mother and brother carried the splice-site mutation, but not the missense mutation. Patient 2 was homozygous for a novel 1-bp deletion (cytosine) at codon 131 in exon 2. This 1-bp deletion produces a frameshift in translation and introduces a premature stop codon (TAG) proximal to the highly conserved heme iron-binding cysteine at codon 442 in microsomal cytochrome P450 steroid 17alpha-hydroxylase (P450c17). RFLP analysis showed that the mother was heterozygous for the mutation.

Adolescent↗

Tissue distribution, cellular source, and structural analysis of rat immunoreactive uroguanylin.

Uroguanylin, a member of the guanylin peptide family, acts on guanylyl cyclase C (GC-C) to regulate intestinal and renal fluid and electrolyte transport through the second messenger, cGMP. Using an antiserum raised against synthetic rat uroguanylin, we established an RIA and identified three endogenous molecular forms in the intestine and kidney: a 15-amino acid uroguanylin, an 18-amino acid uroguanylin that is a monobasic processing product, and a 9.4-kDa prouroguanylin. Prouroguanylin is the major molecular form in these two tissues, whereas only 15-amino-acid uroguanylin is present in the urine. Rat uroguanylin is most abundant in the proximal small intestine, its content decreasing toward the colon. Uroguanylin is present immunohistochemically in the endocrine cells in the intestine and stomach, B cells in the pancreatic islets, and tubular epithelial cells in the kidney. Uroguanylin has a widespread tissue distribution and is located in cells that function in an endocrine, paracrine, and/or luminocrine (luminal secretion) fashion. Uroguanylin may have physiological functions other than the regulation of fluid and electrolyte transport in the intestine and kidney.

Amino Acid Sequence↗

Genomic structure and chromosomal localization of human uroguanylin.

Uroguanylin, a member of the guanylin peptide family, is a novel peptide regulator in intestinal salt and water transport. We isolated the gene for uroguanylin from a human genomic library and determined its structure. This gene consists of three exons and two introns within an overall length of 2.5 kb. The 5' flanking region has TATA and CAAT boxes. The gene also has multiple binding sites for promoter-specific transcription factor, activator protein-1, and activator protein-2, and a cAMP-regulated enhancer element. Fluorescence in situ hybridization showed the uroguanylin gene at human chromosome 1p33-p34. RNA blot analysis showed that human uroguanylin mRNA is expressed in the gastric fundus and pylorus as well as in the intestine.

Amino Acid Sequence↗

A 5'-splice site mutation in the cytochrome P450 steroid 17alpha-hydroxylase gene in 17alpha-hydroxylase deficiency.

17alpha-Hydroxylase deficiency (17OHD) is an autosomal recessive disorder that produces an excess of mineralocorticoids and sexual differentiation abnormalities. Using DNA sequencing analysis of the 17alpha-hydroxylase (CYP17) gene from a Japanese patient with 17OHD, we identified a new type of genetic abnormality in this disease, a G to A transition at position +5 in the splice donor site of intron 7 of the CYP17 gene. In vitro expression analysis of an allelic minigene that consists of exons 6-8 of the patient's CYP17 gene showed that the transition causes the skipping of exon 7. This exon skipping alters the translational reading frame of exon 8 and introduces a premature stop codon (TAA) at amino acid position 410 proximal to the heme iron-binding site essential for the enzymatic activity of CYP17. Restriction enzyme analysis showed that the patient is homozygous for the mutated CYP17 gene, and the parents are heterozygotes. This is the first reported patient with 17OHD caused by the splice site mutation in the CYP17 gene.

Adrenal Hyperplasia, Congenital↗

Systemic sclerosis associated with diabetes insipidus.

A rare case of systemic sclerosis that preceded the development of diabetes insipidus is reported. This 25-year-old man presented with Raynaud's phenomenon and ulceration of the tip of the right thumb. The diagnosis of systemic sclerosis was based on findings of proximal scleroderma, sclerodactyly, serological abnormalities, and skin abnormalities verified histologically. Partial central diabetes insipidus was later diagnosed after the sudden appearance of polyuria and polydipsia. Coexistence of systemic sclerosis with diabetes insipidus suggests that diabetes insipidus in this patient might have occurred via an autoimmune mechanism.

Adult↗

Uroguanylin gene expression in the alimentary tract and extra-gastrointestinal tissues.

Uroguanylin, a member of the guanylin peptide family, is a novel peptide regulator for intestinal salt and water transport. A cDNA encoding a precursor for rat uroguanylin was cloned from a rat jejunum cDNA library and sequenced. The precursor was 106 amino acids long and included a 21 residue putative signal peptide at the N-terminus. Rat uroguanylin consisted of 15 amino acids similar to, but distinct from human uroguanylin; the C-terminal leucine residue was deleted and 3 residues were substituted compared to those in the human peptide. Synthetic rat uroguanylin-15 dose-dependently increased the cyclic GMP level in cultured T84 cells. RNA blot analysis showed that rat uroguanylin mRNA is expressed not only in the gastrointestinal tract but also in the lung, pancreas and kidney. Evidence for uroguanylin expression in extra-gastrointestinal tissues indicates the possible existence of a novel system for water and electrolyte homeostasis, and a more global effect of uroguanylin on epithelial cell function.

Amino Acid Sequence↗

Cloning and characterization of a cDNA encoding a precursor for human uroguanylin.

Uroguanylin, a member of the guanylin peptide family, is an endogenous activator of intestinal guanylate cyclase (GC-C). A cDNA encoding a precursor for human uroguanylin was cloned from a human colon cDNA library and sequenced. The precursor was 112 amino acids long and included a signal peptide at the N-terminus and the human uroguanylin sequence at the C-terminus. RNA blot analysis and the reverse transcription-polymerase chain reaction (RT-PCR) showed that human uroguanylin mRNA is expressed in the stomach and intestine. Uroguanylin, as well as guanylin, may be a potent physiological regulator of intestinal fluid and electrolyte transport.

Amino Acid Sequence↗

Tissue distribution and plasma concentration of human guanylin.

Guanylin, a peptide homologue of the bacterial heat-stable enterotoxins, is an endogenous activator of guanylate cyclase C (GC-C). We determined the tissue content and plasma concentration of human guanylin, and its cellular source in the intestine. Human guanylin is distributed widely from the duodenum to the rectum, the highest content being in the ileum and proximal colon. The plasma concentration of immunoreactive guanylin in the normal individuals tested was 30.3 +/- 3.7 fmol/ml (mean +/- SE) and that in patients with chronic renal failure was elevated with increasing serum creatinine concentration. Guanylin immunoreactivity was detected in the villus epithelial cells in the small intestine and these guanylin-containing cells were increased in number along the cephalocaudal axis of the gut. Guanylin was also present in Paneth cells in the small intestine and superficial epithelial cells in the large intestine. Guanylin mRNA was detected in the intestine by the reverse transcription-polymerase chain reaction. Guanylin may have paracrine action on neighboring enterocytes, activating intestinal guanylate cyclase and thereby regulating intestinal fluid as well as electrolyte transport through the second messenger, cyclic GMP.

Adolescent↗

[Intermittent hydronephrosis. A clinical study in 23 pediatric patients].

BACKGROUND: It is difficult to diagnose intermittent hydronephrosis and to decide the indication of surgical intervention. We investigated 23 cases of intermittent hydronephrosis. METHODS: From 1978 to 1995, a total of 23 patients were diagnosed as intermittent hydronephrosis in our institution. We inspected their clinical features and treatment which had been performed to them. RESULTS: Our study comprised 21 boys and 2 girls, whose mean age was 6 year old. Their chief complaint was intermittent flank pain (left: 21, right: 1, bilateral: 1) accompanied with gross hematuria (30%) and vomiting (39%). When they were asymptomatic, an excretory urogram revealed only mild pelvic dilatation without calyceal distension and kinking of ureteropelvic junction. Split renal function study by RI showed no difference between the affected side and the normal side except one case. When pelvic or calyceal enlargement was confirmed on ultrasonography while they were symptomatic, surgery was indicated. Surgery was performed in 17 cases (74%) including dismembered pyeloplasty in 14 cases, resection of aberrant vessel in 1, relocation of lower pole renal vessel in 1 and nephrectomy in 1. In surgical and histological view points, intrinsic stenosis was seen in 10 cases, extrinsic obstruction caused by aberrant vessels was seen in 4 and ureteral polyp was seen in 3 (bilateral polyp in 1 case). CONCLUSION: They had no more symptoms after operation. Of 23 among followed up cases without surgery, we experienced 2 cases unexpectedly advancing irreversible hydronephrotic change after the last attack, 1 case of gradually progressing hydronephrotic change and 1 case of severe renal dysfunction after many attacks. Therefore intermittent hydronephrosis should be followed up carefully.

Child↗

[Two cases of severe bacterial meningitis with paranasal sinusitis followed by cerebrovascular disease--pathophysiology and treatment of cerebrovascular disease].

We report two cases of pneumococcal meningitis with paranasal sinusitis followed by cerebrovascular disease. Both cases were occupational divers, and had past histories of head trauma and paranasal sinusitis. Despite the combined therapy with antibiotics and dexamethasone, they developed cerebrovascular complications. Case 1 developed cerebral infarction and hemorrhage on day 13, and in case 2 cerebral infarction occurred on day 15. In both cases, serum levels of TNF-alpha and IL-6 were elevated in the early stage of the illness (12 pg/ml and 21.3 pg/ml in case 1, and 50 pg/ml and 7,570 pg/ml in case 2, respectively). In case 2, TNF-alpha, IL-1 beta and IL-6 levels in the cerebrospinal fluid were also elevated on day 4 (25 pg/ml, 320 pg/ml and 6,870 pg/ml, respectively). Thrombocytosis was observed in both cases before the onset of the cerebrovascular complications. These cytokines may play significant roles in thrombocytosis leading to cerebrovascular complications in pneumococcal meningitis. Although the use of steroids as adjunctive therapy for bacterial meningitis has been found to be beneficial, the dosage of dexamethasone administered in our cases may not be enough to suppress the synthesis and release of the cytokines. Therefore, administration of large doses of glucocorticoid should be recommended before the treatment with antibiotics.

Adult↗