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Biomedical subjects

F Ito

Publications and source records attributed to F Ito.

At least 55 records · Page 3Linked to original sources
PubMed1999

Angiotensin II type 1 receptor expression in two cases of juxtaglomerular cell tumor: correlation to negative feedback of renin secretion by angiotensin II.

The angiotensin II (Ang II) type 1 (AT1) receptor is highly expressed on juxtaglomerular (G) cells and is assumed to be involved in the negative short loop feedback regulation of renin secretion and in the suppression of Ang II-mediated JG cell proliferation and/or growth. However, as JG cell tumor is rare, expression and pathophysiological significance of AT1 receptor expression in JG cell tumor remain unknown. In the present study, we investigated renin responses to various treatments, including the angiotensin converting enzyme inhibitor captopril, and correlated the results with AT1 and Ang II type 2 (AT2) receptor mRNA expression levels in two cases of JG cell tumor. Whereas plasma renin activity (PRA) did not show any significant change in Case 1, it was increased by 72% in Case 2 in response to captopril challenge. In concordance with these results, AT1 receptor mRNA was not detected in tumor tissue of Case 1 but was clearly demonstrated in the tumor of Case 2. AT2 receptor mRNA expression was not detected in either of the cases. In contrast to captopril challenge, PRA was suppressed by 30% in Case 1 and 42% in Case 2 in response to saline infusion, and was increased by 230% in Case 1 and 59% in Case 2 in response to furosemide-upright posture for 2 h. These results suggest that the short loop feedback inhibition of renin secretion by Ang II in JG cell tumor is closely related to AT1 receptor expression levels in the tumor tissue. In addition, the result suggested that despite its autonomy, renin secretion from JG cell tumor is still under physiological regulatory control.

Adenocarcinoma↗
PubMed1999

Purification and characterization of bovine pancreatic bile salt-activated lipase.

An enzyme with lipase and esterase activity was purified from bovine pancreas. Furthermore, a non-radioactive lipase assay was developed which is 100 times more sensitive than the conventional methods and allowed the characterization of the lipase activity of the enzyme. The lipase activity increased 42 times in the presence of 10 mM sodium taurocholate, which for the first time provides direct evidence that a bile salt-activated lipase (bp-BAL) was isolated from bovine pancreas. This conclusion is further supported by the fact that the N-terminal amino acid sequence of this lipase/esterase is 88% homologous to human milk BAL and human pancreatic BAL. Staining with various lectins showed that bp-BAL is a glycoprotein which contains fucose residues. Previously from bovine pancreas a lysophospholipase has been purified and a gene was cloned and sequenced encoding an enzyme with cholesterol esterase/lysophospholipase activity. Comparison of the N-terminal amino acid sequence of bp-BAL with the deduced amino acid sequence of the latter revealed that they are identical. Furthermore, the molecular weight of the purified bp-BAL of 63,000, as estimated by SDS-PAGE, is very similar to that of the purified lysophospholipase (65,000) and to the theoretical molecular weight of 65,147 of the cholesterol esterase/lysophospholipase. These data suggest that these three enzymes are one and the same.

Amino Acid Sequence↗
PubMed1999

Transverse cervical artery bypass pedicle for treatment of common carotid artery occlusion: new adjunct for revascularization of the internal carotid artery domain.

OBJECTIVE: We present two cases of common carotid artery occlusion that were treated by vascular reconstruction using the transverse cervical artery. METHODS: Two patients with common carotid artery occlusion presented with transient ischemic attacks resulting from decreased cerebral blood flow on the affected side. Both patients underwent vascular reconstruction using the transverse cervical artery. The transverse cervical artery was anastomosed to the ipsilateral external carotid artery at its origin, as a pedicle graft. A superficial temporal artery-middle cerebral artery anastomosis was then performed. RESULTS: The postoperative courses were uneventful. The transverse cervical artery bypass grafts were patent, and cerebral blood flow increased to normal levels. CONCLUSION: Transverse cervical artery grafting provides a less tedious alternative to saphenous vein interposition grafting for revascularization of the internal carotid artery domain.

Aged↗
PubMed1999

[Renal angiomyolipoma with a tumor thrombus extending into the right atrium--a case report].

We present a case of spontaneous rupture of renal angiomyolipoma with a tumor thrombus extending from the right renal vein and inferior vena cava to the right atrium. A 41-year-old woman, previously in good health, was referred to our hospital with right flank pain. Computed tomography showed fat densities in both tumor and thrombus. Other imaging examinations also demonstrated a large right renal mass (18 cm in diameter), a long tumor thrombus (13 cm in length) and a small left renal tumor (1.5 cm in diameter). Right nephrectomy and en-bloc removal of the intra caval and intracardiac tumor thrombus were performed on cardiopulmonary bypass. It was pathologically diagnosed as an angiomyolipoma without tuberous sclerosis. At present, three years after surgery the patient is doing well, showing neither metastasis nor increase of the left renal angiomyolipoma. To our knowledge, our case seems to be the 3rd case report of renal angiomyolipoma with a tumor thrombus extending to the right atrium. We conclude that renal angiomyolipoma even with an intra cardiac tumor thrombus can be resected safely and successfully.

Adult↗
PubMed1999

[A case of sudden death by pulmonary embolism after angio-embolization of renal cell carcinoma extending into the inferior vena cava].

We report a 42-year-old renal-transplanted man with renal cell carcinoma (RCC) in the native kidney. He was admitted with gross hematuria and general fatigue as the chief complaint. Ultrasonography, computed tomography, magnetic resonance imaging and angiography, revealed a right RCC with intracaval tumor thrombus extending to the level of hepatic veins. Since selective renal angiography demonstrated a hypervascular tumor, angio-embolization was performed preoperatively. However, he died suddenly the next morning despite aggressive resuscitative measures. Autopsy revealed bilateral pulmonary arteries obstructed by the tumor thrombus. Renal arterial embolization is useful for advanced RCC, and side effects are mostly transient and well tolerated by the patients. However, indications for angio-embolization should be selected carefully with such a fatal case as this patient kept in mind.

Carcinoma, Renal Cell↗
PubMed1999

Ethanol injection therapy of the prostate for benign prostatic hyperplasia: preliminary report on application of a new technique.

PURPOSE: We evaluate the efficacy of a new technique of minimally invasive treatment for benign prostatic hyperplasia involving direct injection of dehydrated ethanol. MATERIALS AND METHODS: Dehydrated ethanol was injected transurethrally with lumbar or sacral and urethral anesthesia in 10 patients with prostatic hyperplasia. Endoscopic injection was performed at 4 to 8 sites in the prostate and 3.5 to 12.0 ml. ethanol were used. RESULTS: There were no intraoperative complications but postoperative urinary retention occurred transiently in all patients which required catheterization for a mean of 8.8 days. Mean symptom score plus or minus standard deviation was 12.2+/-5.8 at 3 months postoperatively, which was significantly improved from 23.1+/-7.0 preoperatively (p<0.01). Mean quality of life score also improved significantly from 5.1+/-0.6 preoperatively to 3.2+/-1.5 at 3 months postoperatively (p<0.01), mean peak urinary flow rate increased from 8.0+/-2.2 (9 patients) to 13.1+/-3.6 ml. per second (p<0.05) and mean residual urine volume decreased from 129.1+/-55.3 (9 patients) to 49.3+/-34.7 ml. (p<0.05). There was no significant change in prostate volume. Acute epididymitis and chronic prostatitis occurred in 1 patient each. CONCLUSIONS: This technique can be performed as an outpatient procedure and appears to be safe and cost-effective. Retrograde ejaculation can be avoided.

Aged↗
PubMed1998

Molecular cloning of a novel putative Ca2+ channel protein (TRPC7) highly expressed in brain.

We have isolated cDNA clones for a novel human protein, TRPC7 (transient receptor potential-related channels), which consists of 1503 amino acid residues from the fetal brain and caudate nucleus cDNA libraries. Northern blot analysis indicated that the TRPC7 gene is highly expressed as a 6.5-kb transcript in brain. The TRPC7 protein has significant homology with Caenorhabditis elegans hypothetical proteins T01H8.5, C05C12.3, and F54D1.5 and with Drosophila and human transient receptor potential (trp) proteins. The TRPC7 protein has seven putative transmembrane domains that probably constitute a Ca2+ channel as in the above-mentioned proteins. Genomic sequencing revealed that the TRPC7 gene consists of 32 exons spanning approximately 90 kb. The TRPC7 gene was mapped between D21S400 and D21S171 on human chromosome 21q22.3, 14 kb distal to a NotI site in D21S400. This novel TRPC7 gene could be a candidate gene for genetic disorders such as bipolar affective disorder, nonsyndromic hereditary deafness, Knobloch syndrome, and holoprosencephaly, which were mapped to this region.

Amino Acid Sequence↗
PubMed1998

Widespread occurrence of the micro-organism Wolbachia in ants.

For more than 20 years, sex allocation in hymenopteran societies has been a major topic in insect sociobiology. A recurring idea was that relatedness asymmetrics arising from their haplodiploid sex determination system would lead to various parent-offspring conflicts over optimal reproduction. A possible weakness of existing theory is that only interests of nuclear genes are properly accounted for. Yet, a diversity of maternally transmitted elements manipulate the reproduction of their host in many solitary arthropod groups. The bacterium Wolbachia is a striking example of such a selfish cytoplasmic element, with effects ranging from reproductive incompatibility between host strains, induction of parthenogenesis and feminization of males. This paper reports on a first PCR-based Wolbachia screening in ants. Out of 50 Indo-Australian species, 50% screened positive for an A-group strain. One of these species also harboured a B-group strain in a double infection. Various factors that might explain the unusually high incidence of Wolbachia in ants are discussed. In general, Wolbachia may represent a widespread and previously unrecognized party active in the conflicts of interest within social insect colonies.

Animals↗
PubMed1998

Antagonistic regulation of cell migration by epidermal growth factor and glucocorticoid in human gastric carcinoma cells.

Epidermal growth factor (EGF) induced the disruption and scattering of colonies of TMK-1, a cell line derived from a human gastric carcinoma. A stimulatory action of EGF on cell migration was also observed as determined by a wound assay. However, these actions of EGF were inhibited if the cells were pretreated with dexamethasone, a synthetic glucocorticoid. Dexamethasone increased cell adhesion to collagen type IV and laminin, but not to poly-L-lysine and fibronectin. In contrast, EGF did not affect cell adhesion to these extracellular matrices whether dexamethasone was present or not. Dexamethasone enhanced the protein levels of both alpha1 and beta1 integrin subunits, and that of the alpha1 beta1 heterodimer. Further, flow cytometric analysis revealed that dexamethasone increased the expression of beta1 and alpha1 integrin subunits at the cell surface, whereas EGF increased expression of beta1 and alpha2 subunits at the cell surface. Antibodies against alpha1 and beta1 integrin subunits inhibited the increased cell adhesion seen in the presence of dexamethasone. An immunofluorescence study indicated that dexamethasone increased the formation of focal adhesions along the entire edges of cell colonies. In contrast, EGF led to the formation of focal adhesions preferentially at the cell front, and this EGF-induced preferential formation was not observed if the cells were pretreated with dexamethasone. These results suggest that glucocorticoid increased cell adhesion to the extracellular matrix via alpha1 beta1 integrin, and thereby antagonized EGF-induced cell migration.

Cadherins↗
PubMed1998

Correlation between the growth of uterine leiomyomata and estrogen and progesterone receptor content in needle biopsy specimens.

OBJECTIVE: To examine the relationship between estrogen receptor (ER) and progesterone receptor (PR) content in needle biopsy specimens and the growth of uterine leiomyomata after biopsy. DESIGN: Prospective clinical study. SETTING: University teaching hospital. PATIENT(S): Thirty-one women with uterine leiomyomata and a normal menstrual cycle. INTERVENTION(S): Transcervical needle biopsy of uterine leiomyomata. MAIN OUTCOME MEASURE(S): The relationships between histologic features (smooth muscle content, immunohistochemical expression of ER and PR) and the percent increase over a 12-month observation period in the volume of the largest myoma nodule measured by magnetic resonance imaging were analyzed. RESULT(S): Both the density and intensity of immunohistochemical staining of PRs in uterine leiomyoma tissue showed significant positive correlation with leiomyoma growth. CONCLUSION(S): The growth of uterine leiomyomata can be determined by histologic and immunohistochemical analysis of needle biopsy specimens from uterine leiomyomata.

Adult↗
PubMed1998

Extrinsic nerve strands in the aganglionic segment of Hirschsprung's disease.

BACKGROUND/PURPOSE: The distributions and pathways of the extrinsic enteric nerves in the aganglionic segment in Hirschsprung's disease (HD) have not been delineated completely. The authors have clarified the major pathways and the details of fine distribution of the extrinsic nerves in the aganglionic segment of a congenital aganglionosis rat. Further investigation was extended to apply those findings in human materials. METHODS: Five HD patients, eight fetuses, and two postmortem neonates with normally innervated colon were examined. Specimens were observed by histochemical technique using light microscopy in whole-mount preparations. RESULTS: Two sets of extrinsic nerve strands were observed in the distal aganglionic colon; one consisted of a continuous network located between the longitudinal and circular muscle coats, and the other involved branches that mainly coursed along the blood vessels in the submucosal layer originating from the nearby mesentery. These two sets of nerve strands were similar to those of aganglionosis rats. Also, thick nerve strands were found running longitudinally in the myenteric layer in the normally ganglionated colon of 18- and 21-week-old fetuses. These nerve strands were unclear in a 32-week-old fetus. CONCLUSIONS: This study showed the following: (1) the origin of the nerve strands in the myenteric layer is mainly the pelvic nerve plexus and (2) the number of ascending extrinsic nerve strands decreases from the proximal colon in cases of long-segment aganglionosis, which may be caused by the same process that occurs in the normally innervated bowel.

Colon↗
PubMed1998

Surgical removal of protein plugs complicating choledochal cysts: primary repair after adequate opening of the pancreatic duct.

BACKGROUND/PURPOSE: Recently, pancreaticoduodenectomies have been performed for choledochal cysts complicated by protein plugs. The authors describe a new surgical procedure for removal of protein plugs or pancreatic stones that does not involve pancreatectomy. METHODS: Protein plugs were detected in 43 (34.1%) of 126 pediatric patients with choledochal cysts. The plugs disappeared spontaneously in 26 patients and were removed using nonsurgical methods in seven. The 10 patients treated surgically are considered here. RESULTS: Protein plugs were removed with the residual cyst in one patient. The plugs in the common channel were flushed into the duodenum by irrigation with saline through the narrow segment beneath choledochal cyst in another. The plugs were removed through the narrow segment using a blunt spoon in four. In the other four patients, the plugs that were too large or too hard to be removed through the narrow segment were taken away through an incision in the main pancreatic duct. This was followed by primary closure of the main pancreatic duct using the narrow segment as a flap to prevent stricture formation. All of the patients have done well. CONCLUSIONS: Protein plugs complicating choledochal cysts can be removed without pancreatectomy. Particularly, primary repair of the pancreatic duct using a flap made of the narrow segment beneath the choledochal cyst is a safe and feasible method to remove large or hard protein plugs.

Adolescent↗
PubMed1998

Combined resection of abdominal aorta and inferior vena cava for retroperitoneal rhabdomyosarcoma invading the aortoiliac bifurcation.

The authors report on an 11-year-old boy with retroperitoneal alveolar rhabdomyosarcoma at the aortoiliac bifurcation. The tumor was resected en bloc together with the infrarenal abdominal aorta and the inferior vena cava. The aortic defect was repaired successfully with a Y-shaped Dacron graft. The authors conclude that tumor resection with aortic reconstruction can be a choice for unresectable retroperitoneal tumors in children.

Aorta, Abdominal↗
PubMed1998

Vertigo secondary to hypotension: the relationship between therapeutic effects and hearing.

Patients with vertebrobasilar insufficiency tend to develop transient, repeated vertigo. However, diagnostic criteria by which to definitively diagnose circulatory disturbance of the vertebrobasilar system have yet to be established. Thus, in order to determine such criteria the relationship between the therapeutic effects on clinical symptoms and hearing in 40 patients with vertigo secondary to hypotension were investigated in the present study. In most patients, vertigo was perceived as a floating or spinning sensation which occurred spontaneously or during positional changes and lasted for a short period of time without hearing disturbance. Audiometry revealed bilateral low-frequency hearing loss or a tendency to low-frequency hearing loss in all patients. Low-frequency hearing loss is an important audiometric indication of vertebrobasilar insufficiency. Such hearing loss is very responsive to therapeutic circulatory agents and is considered to be an index for the evaluation of the effects of treatment for vertebrobasilar insufficiency.

Adenosine Triphosphate↗