Biomedical subjects

Takahiro Akiyama

Publications and source records attributed to Takahiro Akiyama.

5 recordsLinked to original sources

PubMed2005

Factors predicting long-term graft survival after kidney transplantation: multicenter study in Japan.

A multicenter retrospective study was conducted in 936 living donor kidney transplant recipients treated with cyclosporine (CsA) or tacrolimus (FK) from April 1982. The influences of acute rejection, hyperlipidemia, and hypertension were estimated by Kaplan-Meier's analysis and Wilcoxon's analysis. Of 916 recipients, 532 (58.1%) had acute rejections. The 5- and 10-year graft survival rates in the recipients with acute rejection were 75.2% and 55.2%, respectively. The corresponding rates of the recipients without acute rejection were 80.2% and 70.6%, respectively. The graft survival rate was worse in recipients with late-phase rejection and multiple rejection episodes (p < 0.00006). Of 451 recipients, 176 (39.0%) had hypercholesterolemia 3 years after kidney transplantation. The 5- and 10-year graft survival rates in the recipients with hypercholesterolemia were 88.7% and 68.7%, respectively. Those of the recipients without hypercholesterolemia were 95.2% and 83.9%, respectively. The graft survival rate in the recipients with hypercholesterolemia was lower than that in the recipients without hypercholesterolemia (p = 0.003). Of 323 recipients, 123 (38.1%) had hypertriglyceridemia 3 years after kidney transplantation. The 5- and 10-year graft survival rates in the recipients with hypertriglyceridemia were 93.7% and 80.5%, respectively. Those in the recipients without hypertriglyceridemia were 95.1% and 86.5%, respectively. The graft survival rate in the recipients with hypertriglyceridemia was lower than that in the recipients without hypertriglyceridemia (p = 0.371). Of 367 recipients, 151 (41.1%) had systolic hypertension 3 years after kidney transplantation. The 5- and 10-year graft survival rates in the recipients with hypertension were 85.6% and 64.7%, respectively. Those of the recipients without hypertension were 95.6% and 83.8%, respectively. The graft survival rate in the recipients with hypertension was lower than that in the recipients without hypertension (p < 0.001). Acute rejection, hyperlipidemia (hypercholesterolemia and hypertriglyceridemia), and hypertension are predictive factors for long-term graft survival. Especially the onset time, number of rejections, and efficacy of treatment for acute rejection would have a significant influence on long-term graft survival.

Adolescent↗

PubMed2004

Venous abnormalities incidentally accompanied by renal tumors.

We retrospectively examined the cases of renal tumors experienced between 1993 and 2002 to evaluate the rates of incidence and preoperative identification by imaging techniques, mainly CT, of retroperitoneal venous abnormalities. Among a total of 178 renal cell carcinomas and 13 renal benign tumors, the incidence of multiplicity of renal veins was 5.3%, restricted to operatively confirmed cases (9 out of 170 cases). None of these multiplicities could be detected by preoperative radiological examinations. Other major venous abnormalities included duplications of inferior vena cava and retroaortic left renal vein and spontaneous splenorenal shunt which were all correctly diagnosed preoperatively. The incidence of these abnormalities was 0.52% (1 out of 191 cases for each). A retroperitoneal venous anomaly is common, but urologists must have sufficient knowledge about acquired retroperitoneal venous abnormalities, which seem rather uncommon, to be prepared for the potential hazards which may occur during urological operations.

Carcinoma, Renal Cell↗

PubMed2003

[Phenotypic changes in human bladder smooth muscle cell].

Tissue specimens were resected from 15 patients (age 7 to 82, average 52.2 years old) with bladder diseases; i.e., 2 with neurogenic bladder, 6 recipients of kidney transplantation with defunctionalized bladder, 3 with benign prostatic hypertrophy, 3 with bladder cancer and 1 with vesicoureteral reflux. We investigated the phenotypic expression of the bladder smooth muscle cells with bladder diseases. The ratio of non-contractile to contractile phenotypes (nc/c ratio) showed a rising tendency with aging. The increase of nc/c ratio was especially notable with neurogenic bladder. Phenotypic expression was observed in human bladder smooth muscle cells as reported in vascular smooth muscle cells. Several bladder diseases cause a conversion of contractile smooth muscle cell phenotype from contractile type to non-contractile type, and this modulation of smooth muscle cell phenotype may play an important role in detrusor function.

Adolescent↗

PubMed2002

Mutations of stonewall disrupt the maintenance of female germline stem cells in Drosophila melanogaster.

Germline stem cells located at the anterior tip of the adult Drosophila melanogaster ovary are critical to the continuous production of mature eggs. Following germline stem cell division, one daughter cell remains a stem cell, while the other becomes a cystoblast committed to differentiation. In this study it was shown that mutations in the putative transcription factor stonewall (stwl) disrupted the maintenance of female germline stem cells. The stwl mutations resulted in a loss of germline stem cells, causing a rapid decrease in egg chamber production. The egg chambers developed only to a limited extent before degenerating. The four mitotic cystocyte divisions were frequently inhibited by stwl mutations. Furthermore, some stwl germaria from newly emerged females completely lacked both stem cells and developing cysts and had a strong reduction in size. The argument is presented here that stwl is involved in the continuation of cell division during female germline development.

Alleles↗

PubMed2002

[Evaluation of the management of blunt renal trauma and indication for surgery].

OBJECTIVES: Appropriate management of renal trauma is still controversial. Many of the patients have minor injuries and conservative treatment can achieve excellent outcomes without any complications. For major injuries of deep lacerations or ruptures, we have been performing early surgical treatment to salvage the kidney in the selected cases after the precise evaluation of the injury. To obtain the optimal management options, we evaluated the clinical results of our procedures. PATIENTS AND METHODS: We conducted a retrospective study, which included 106 cases of blunt renal trauma with evident etiology over the past 22 years and 9 months. The severity of the injury was evaluated mainly by CT scanning. The indication of renal exploration included persistent renal bleeding, large hematoma around the kidney, dislocated fragments, nonviable tissue, massive urinary extravasation and vascular injury. With the patients who required an operation, we first controlled the bleeding by clamping the hilar vessels. Then, the final decision whether to repair or remove the kidney was made based on the direct inspection of the injured kidney after the complete removal of the hematoma. The severity of renal trauma was classified by the classifications found in The Organ Injury Committee of the American Association for the Surgery of Trauma. RESULTS: Sixty-three patients were managed conservatively without any interventions, while 22 surgical repairs and 21 nephrectomies were performed. Of the 63 patients, 35 patients (81.4%) were operated on within 2 days after the injury. Judging from systolic blood pressure, red cell count, blood loss during surgery and transfusion requirements, surgically treated patients were more severely injured than conservatively treated patients. And nephrectomized patients than surgically repaired patients. All the surgically repaired cases were confirmed to have preserved renal functions postoperatively. In all of the 50 patients with Grade I injuries, conservative treatment was successful. Eight out of the 19 Grade II and III cases, who were indicated for kidney exploration because of multiple lacerations or considerable bleeding, were also successfully repaired. Localized hematoma with no urine leakage, even when it was large, settled spontaneously without complication. For the 37 Grade IV and V injuries, including 4 cases with hilar injuries, we implemented conservative procedures on 2 patients, surgical repair on 14 patients and nephrectomy on 21 patients. In the conservatively treated cases, one deep laceration with relatively large, but localized, hematoma, and minimal urine extravasation healed spontaneously. Atrophy of the segment and hypertension developed in the other ruptured kidney with dislocated fragments, large hematoma and urine leakage. This kidney, which also required later surgical exploration, did have good parenchymal blood flow. Hilar injury cases were all resulted in nephrectomy. CONCLUSION: In most of our cases the indication for surgical exploration or nephrectomy based on our criteria seemed to be properly decided. Several cases, though, might have received overtreatment. Recent advances in evaluations and strategies of renal trauma have decreased the need for surgical exploration. This may have overreached the indication for conservative management. Severely injured kidneys may be managed conservatively because in most cases bleeding settles after the full formation of large hematoma within the Gerota's fascia. In such cases, though, no one can predict whether the injury will heal spontaneously or not, and, moreover, whether a complication will develop or not. We think that the optimal management of the patient requires an accurate evaluation of the injured kidney. Therefore the indication for surgical exploration should be made based on the degree of the injury.

Adolescent↗