Biomedical subjects

Hiroki Shima

Publications and source records attributed to Hiroki Shima.

At least 19 recordsLinked to original sources

PubMed2006

Retroperitoneal ancient schwannoma presenting as an adrenal incidentaloma: CT and MR findings.

A 35-year-old woman was referred to our institution for additional examinations to evaluate bilateral suprarenal masses incidentally found on abdominal ultrasonographic images obtained during an annual medical health checkup. Our computed tomographic scans showed bilateral and well-circumscribed low-density suprarenal masses, while MRI revealed the tumors to be heterogeneous with low intensity on T1-weighted images and high intensity on T2-weighted images. A laparoscopic adrenalectomy was performed under the suspicion of a malignant tumor, such as a malignant fibrous histiocytoma. Pathologic findings indicated a retroperitoneal ancient schwannoma of two histologic types: Antoni A and Antoni B. We considered that elucidation of the characteristic features of a schwannoma would provide helpful preoperative information for diagnosis.

Abdomen↗

PubMed2006

[Hermaphroditism].

Explore the source record for details and available documents.

Adrenal Glands↗

PubMed2006

Partial androgen insensitivity syndrome with thermolability in the androgen receptor.

We report case of partial androgen insensitivity syndrome in a 12-year-old boy referred to our clinic complaining of bilateral gynecomastia and left undescended testicle. Laparoscopy for undescended testicle and bilateral mastectomy were performed, and the left testicle was absent. When skin fibroblasts of the scrotum obtained during surgery were cultured to analyse the androgen receptors, a slight thermolability was observed. Genomic examination of the androgen receptor gene could not detect any mutations.

Androgen-Insensitivity Syndrome↗

PubMed2006

Testicular seminoma associated with massive necrosis.

A 70-year-old man presented with 2 years history of a painless hard mass in the left scrotum. Both pelvic computed tomography and magnetic resonance image showed enhancement only in the wall of the tumor, indicating a benign disease, rather than a neoplastic lesion. Physical examination 3 weeks after the first presentation showed the remarkable reduction of the left testicular size. Left inguinal orchiectomy was carried out and pathological diagnosis was seminoma with extensive necrotic areas occupying mostly the tumor. Either shrinkage or enlargement of testicular size with a long history demands full investigation for malignancy.

Aged↗

PubMed2006

[Orthotopic bladder substitution].

Orthotopic bladder substitution is the most desired form of urinary diversion because the patient can restore normal voiding after cystectomy. However, urethral recurrence must be seriously considered and the patients with a risk of urethral recurrence are not indicated. Each method of bladder substitution has merits and demerits. We compared the Mainz method and the Studer method of orthotopic bladder substitution we performed on 8 and 11 patients, respectively since 1992. The Studer orthotopic ileal bladder substitution has given better results with better voiding pattern and less complication rates. We consider the Studer ileal bladder substitution as a good technique to restore normal voiding after cystectomy.

Aged↗

PubMed2006

[Intra-arterial chemotherapy for invasive bladder cancer (T2-3N0M0)].

We assessed the effectiveness of intra-arterial MVAC chemotherapy or a combination of intra-arterial chemotherapy and external beam radiotherapy based on diagnostic images and histological (transurethral) examination in 15 cases with T2-3NOM0 between January 2003 and September 2005. When the clinical response was assessed one month after the treatments, a complete response (CR) was achieved in 20% (1/5) and 50% (5/10) by intra-arterial MVAC chemotherapy and a combination of intra-arterial chemotherapy and external beam radiotherapy, respectively. Total radical cystectomy was required on one patient during the follow-up period of 4-26 months. Although our result showed that the combination of external beam radiation therapy and intraarterial cisplatin effectively contributed to the preservation of the bladder with localized invasive bladder cancer, radical cystectomy is required when CR is not achieved after this treatment.

Aged↗

PubMed2005

Isolation and characterization of novel xrs2 mutations in Saccharomyces cerevisiae.

The Mre11/Rad50/Xrs2 (MRX) complex is involved in DNA damage repair, DNA damage response, telomere control, and meiotic recombination. Here, we constructed and characterized novel mutant alleles of XRS2. The alleles with mutations in the C-terminal conserved domain of Xrs2 were grouped into the same class. Mutant Xrs2 in this class lacked Mre11 interaction ability. The second class, lacking a C-terminal end, showed defects only in telomere control. A previous study showed that this C-terminal end contains a Tel1-association domain. These results indicate that Xrs2 contains two functional domains, Mre11- and Tel1-binding domains. While the Mre11-binding domain is essential for Xrs2 function, the Tel1-binding domain may be essential only for Tel1 function in telomere maintenance. The third class, despite containing a large deletion in the N-terminal region, showed no defects in DNA damage repair. However, some mutants, which showed a reduced level of Xrs2 protein, were partially defective in formation of meiotic DSBs and telomere maintenance. These defects were suppressed by overexpression of the mutant Xrs2 protein. This result suggests that the total amount of Xrs2 protein is a critical determinant for the function of the MRX complex especially with regard to telomere maintenance and meiotic DSB formation.

Amino Acid Sequence↗

PubMed2005

Kidney displacement simulator for retroperitoneal laparoscopic nephrectomy.

PURPOSE: We evaluated the efficacy of a renal displacement simulator originally developed at our department for retroperitoneal laparoscopic nephrectomy. MATERIALS AND METHODS: A total of 12 patients with a malignant localized renal (7) or ureteral (5) neoplasm underwent multidetector row computerized tomography. Imaging data were sent to a dedicated work station to create volume rendering and virtual laparoscopic images of the kidney, which was displaced ventral using a retroperitoneal balloon. These findings were compared with video images obtained during laparoscopy surgery. RESULTS: The kidney displacement simulator depicted all renal arteries (100% sensitivity) and 13 of 14 renal veins (93% sensitivity). Hilar anatomy, including the tumor, as well as major vessels and their relationships were visualized by the simulator in the laparoscopic views. The major vessel portions completely corresponded to those seen during surgery, and the left adrenal and gonadal veins were also synchronized quite well. CONCLUSIONS: Our kidney displacement simulator was able to visualize the major vessel portions and branched small vessels, such as the adrenal and gonadal veins, prior to surgery. It is considered useful for providing guidance to surgeons and decreasing operative risks and possible complications.

Aged↗

PubMed2005

[The front line on the therapy for VUR in children].

The establishment of a guideline for the therapy of vesicoureteral reflux (VUR) by, the American Urological Association (1997) was one of the most remarkable events in the field of pediatric urology. However, in the daily clinical setting we often have difficulty in deciding whether we should proceed to operate or take a watch and wait policy in patients with high grade VUR. In this debate the indication of surgery, alternative minimal invasive choice, and/or conservative therapy for VUR are discussed from clinical standpoints referring to various cases of VUR.

Antibiotic Prophylaxis↗

PubMed2005

[A case report of bladder hernia associated with prostate cancer].

We report a case of bladder hernia. A 68-year-old man was admitted to our hospital for the management of prostate cancer. An egg-sized soft mass was palpated at his right inguinal region. Magnetic resonance imaging and cystography revealed that the mass was a bladder hernia. During radical prostatectomy, we had to resect the bladder hernia for safe regional lymphadenectomy. This hernia was the extraperitoneal type. The stage of prostate cancer was pT3b N0 M0. This is the third reported case of inguinal bladder hernia associated with prostate cancer in Japan.

Adenocarcinoma↗

PubMed2005

[Spontaneous rupture of renal angiomyolipoma: a case report].

A 55-year-old woman presented with sudden right lower abdominal pain. Computed tomography demonstrated retroperitoneal hematoma associated with minus-density area, diagnosed as spontaneous rupture of angiomyolipoma. Super-selective transarterial embolization was performed, but anemia and right abdominal pain became worse in spite of conservative therapy including transfusion, indicating re-rupture of the renal tumor. Although partial nephrectomy was planned, right nephrectomy was finally performed because of massive intraoperative bleeding. Accurate diagnosis and prompt treatment are required when life-threatening rupture of renal tumor is suspected.

Abdomen, Acute↗

PubMed2004

[Differentiation and development of internal sexual organs, and müllerian inhibiting substance].

Internal sexual organs are differentiated and developed by androgens and regressed by müllerian inhibiting substance(anti-müllerian hormone). The role of 5 alpha-dihydrotestosterone, reduced form of testosterone by 5 alpha-reductase, in terms of development of Wolffian duct is discussed with soluble mesenchymal factor responsible for the epithelial branching morphogenesis of mouse seminal vesicle on the basis of experimental results using organ culture assay of mouse new-born seminal vesicle. An update of müllerian inhibiting substance, a fetal regressor of female internal organs such as uterus, fallopian tubes and upper third vagina, is also discussed.

Androgens↗

PubMed2004

Birth of healthy neonates after intracytoplasmic injection of ejaculated or testicular spermatozoa from men with nonmosaic Klinefelter's syndrome: a report of 2 cases.

BACKGROUND: Klinefelter's syndrome is one of the major causes of azoospermia, cryptozoospermia and severe oligozoospermia with either a nonmosaic (47,XXY) or mosaic (47,XXY/46,XY) ICSI treatment with cryopreserved testicular spermatozoa failed, but after the third attempt, 6 of 8 oocytes injected with cryopreserved sperm were fertilized and karyotype. Men with Klinefelter's syndrome generally have difficulty having children. CASES: Patient 1 had motile spermatozoa in the ejaculate, which were injected into 3 oocytes, resulting in fertilization and cleavage. Two good-quality embryos were transferred into his wife's uterine cavity. She conceived and, following a normal pregnancy, delivered a healthy female infant. Two years later she conceived for the second time with motile spermatozoa in the ejaculate and delivered a healthy male infant uneventfully. To our knowledge, this was the first case in which a nonmosaic Kleinefelter's syndrome patient fathered 2 children through intracytoplasmic sperm injection (ICSI) using motile spermatozoa in the ejaculate. Patient 2, with azoospermia, was subjected to testicular biopsy to collect spermatozoa. The first 2 attempts at ICSI treatment with cryopreserved testicular spermatozoa failed, but after the third attempt, 6 of 8 oocytes injected with cryopreserved sperm were fertilized and cleaved. Two of these embryos were transferred into the wife's uterine cavity. She conceived and, following a normal pregnancy, delivered a healthy male infant. In all cases, amniocentesis followed by genetic analysis showed a normal karyotype. CONCLUSION: Two infertile men with nonmosaic Klinefelter's syndrome successfully fathered normal children after intracytoplasmic injection of ejaculated or testicular spermatozoa.

Adult↗

PubMed2004

[Epidermoid cyst of perineo-scrotal region: report of a case].

The patient was a 36-year-old male with a chief complaint of painless mass in the perineum. An elastic and immobile mass with the tip of thumb finger size was palpable in the left perineum and magnetic resonance imaging (MRI) showed the tumor with high intensity on T2 weighted image from perineum through left scrotum. The tumor was surgically removed and a histopathological study revealed epidermoid cyst.

Adult↗

PubMed2003

Extra-renal erythropoietin secretion after bilateral nephrectomy.

Serum concentrations of erythropoietin and soluble transferrin receptor were examined immediately after removal of the remaining kidney in a patient with a history of unilateral radical nephrectomy. Unexpectedly, the erythropoietin concentration increased from 18.2 U/L to 42.5 within 6 h after the operation. Soluble transferrin receptor (TfR) concentration rapidly decreased from 2,725 microgram/L to 1,548 during the 12-h postoperative period. Extra-renal erythropoietin secretion could increase to more than twice as much as the renal secretion of erythropoietin immediately after the loss of renal tissue, and the rise in erythropoietin could accelerate the recycling of TfR, thus causing a decrease in its serum concentration.

Aged↗

PubMed2003

[A case of CA19-9 producing transitional cell carcinoma of the ureter].

We report a case of CA19-9 producing urothelial carcinoma of the right ureter. A 61-year-old male patient who had an extremely high value of serum CA19-9 (1,185 U/ml) with right hydronephrosis was referred to us. Magnetic resonance urography and retrograde ureterography revealed a long irregular filling defect in the right distal ureter. Under the diagnosis of right ureteral tumor, we performed right total nephroureterectomy and pelvic lymphadenectomy. The tumor was histologically diagnosed as grade 1 transitional cell carcinoma and pelvic lymphnodes were positive (pT1N2M0). The tumor cells showed positive immunostaining for CA19-9. The serum CA19-9 level was normalized after the operation and successive adjuvant chemotherapy (M-VAC 2 course). No recurrence was found for 15 months after operation. In this case, the serum CA19-9 level was useful as a tumor marker.

Biomarkers, Tumor↗

PubMed2003

[Testicular microlithiasis: report of 14 cases].

Testicular microlithiasis (TM) is a comparatively rare condition in which calcified congelations fill the lumina of the seminiferous tubules. Using high-frequency linear transducers (10 MHz), TM is easily demonstrated as tiny punctate echogenic foci, which typically do not give an acoustic shadow, and is classified into classic type (CTM) and limited type (LTM) on the basis of the presence of five or more microliths at least on one image of the testes. Fourteen patients were found to have TM, 6 of which were LTM and 8 were CTM. In one patient with CTM, coexisting mixed germ cell tumor (seminoma, embryonal cell carcinoma) was demonstrated. Until further data are available, it seems reasonable to consider patients with TM as having an increased risk of developing a primary testicular tumor.

Adolescent↗

PubMed2002

Primary carcinoid tumor of the urinary bladder.

A polyp of about 1.0 cm diameter was incidentally found at the center of the posterior wall of the urinary bladder in a 73-year-old man on cystoscopic examination. A polyp was resected through a transurethral route without recurrence for 22 months. A polyp consisted of a tumor covered with mucosa of the bladder. Tumor cells have round or oval nuclei with fine chromatin and one or two nucleoli per nucleus, and finely granular eosinophilic cytoplasm, being arranged in a trabecular or tubular pattern. Furthermore, they showed positive staining for chromogranin-A and with Grimelius stain, indicating that the tumor is a carcinoid tumor. Since there was no evidence of carcinoid tumors in organs other than the urinary bladder, the present case is a primary carcinoid tumor (well differentiated endocrine tumor) of the urinary bladder which is extremely rare.

Aged↗