PubMed Health⌕ Search

Biomedical subjects

Keiji Sano

Publications and source records attributed to Keiji Sano.

At least 19 recordsLinked to original sources
PubMed2007

Changes of bone mineral density after cementless total hip arthroplasty with two different stems.

Cementless total hip arthroplasty has achieved reliable long-term results since porous coatings were developed, but postoperative changes around the stem remain poorly documented. In this study, changes of the bone mineral density (BMD) were compared between two types of cementless stem. In group B (28 patients with 31 hips), a straight tapered stem with porous plasma spray coating on the proximal 1/4 was used, while group S (24 patients with 26 hips) was given a fluted, tri-slot stem with porous hydroxyapatite coating on the proximal 1/3. In group B, there was an early decrease of BMD, which recovered after 12 months, indicating that stress shielding was minimal. In group S, however, BMD continued to decrease without recovery. The stem shape and radiological findings suggested that the cause of stress shielding in group S was distal fixation.

Absorptiometry, Photon↗
PubMed2006

Assessment of vulnerable plaques causing acute coronary syndrome using integrated backscatter intravascular ultrasound.

OBJECTIVES: This study aims to define tissue characteristics of vulnerable plaques before acute coronary syndrome (ACS) by use of integrated backscatter intravascular ultrasound (IB-IVUS). BACKGROUND: Tissue characterization of coronary plaques is possible with the use of IB-IVUS. METHODS: The subjects were 140 patients with angina pectoris, and we selected 160 coronary lesions without significant stenosis for evaluation. Ultrasound signals were obtained by an IVUS system using a 40-MHz catheter. RESULTS: At the follow-up (30 +/- 7 months), 12 plaques caused ACS after the initial IVUS examination. Ten of the 12 plaques had IVUS parameters recorded at baseline. These 10 plaques were classified as vulnerable plaques (VP), and the other plaques were classified as stable plaques (SP; n = 143). There was no significant difference of vessel area, lumen area, and plaque area between VP and SP. However, plaque burden (60 +/- 9% vs. 52 +/- 9%; p = 0.014), eccentricity (0.70 +/- 0.10 vs. 0.55 +/- 0.17; p = 0.013), remodeling index (1.30 +/- 0.08 vs. 1.16 +/- 0.16; p = 0.006) and percentage lipid area (72 +/- 10% vs. 50 +/- 16%; p < 0.0001) were greater in VP than in SP. Percentage fibrous area (23 +/- 6% vs. 47 +/- 14%; p < 0.0001) was smaller in VP than in SP. The sensitivities, specificities, and positive predictive values of percentage fibrous area (90%, 96%, and 69%, respectively) and percentage lipid area (80%, 90%, and 42%, respectively) for classifying VP were evaluated. CONCLUSIONS: Tissue characteristics of VP before ACS were different from those of SP. This suggests that VP and SP as classified by IB-IVUS are useful in predicting ACS.

Aged↗
PubMed2006

Uracil-tegafur as an adjuvant for hepatocellular carcinoma: a randomized trial.

Frequent recurrence of hepatocellular carcinoma (HCC) after surgery remains a major clinical problem. This randomized controlled trial evaluated whether postoperative adjuvant therapy with oral uracil-tegafur (UFT) prevents recurrence of HCC. A total of 160 patients who underwent curative hepatic resection for HCC were randomly assigned to receive either 300 mg/day of UFT for 1 year after surgery (n = 79, UFT group) or surgery alone (n = 80, control group). The primary endpoint was recurrence-free survival, and the secondary endpoint was overall survival. Other study variables included liver function and type of recurrence. During a median follow-up of 4.8 years (range: 0.5-7.9), recurrence-free survival curves in the groups were similar (P = .87). Overall survival was slightly but not significantly worse in the UFT group than in the control group (P = .08). The rates of recurrence-free and overall survival at 5 years were 29% and 58%, respectively, in the UFT group, as compared with 29% and 73%, respectively, in the control group. The hazard ratio for recurrence in the UFT group, relative to the control, was 1.01 (95% confidence interval: 0.84-1.22, P = .87). The proportion of patients with advanced recurrence (i.e., multiple, extrahepatic, or associated with vascular invasion) was significantly higher in the UFT group (74%, 43 of 58 patients with recurrence) than in the control group (53%, 30 of 57) (P = .02). In conclusion, our results offer no evidence to support potential benefits of adjuvant chemotherapy with UFT after surgery in patients with HCC and suggest that such treatment may even worsen overall survival.

Adult↗
PubMed2006

Simultaneous resection of liver cell adenomas and an intrahepatic portosystemic venous shunt with elevation of serum PIVKA-II level.

A 27-year-old woman with no history of liver disease or oral contraceptive use presented with sudden abdominal pain. Laboratory data showed mild liver dysfunction with jaundice. Computed tomography and angiography revealed centrally located large liver cell adenomas (LCAs) and an intrahepatic portosystemic venous shunt (IHPSS) in the left lobe. The serum des-gamma-carboxy prothrombin (known as "protein induced by a lack of vitamin K or antagonist II," PIVKA-II) level was extremely high (6,647 mAU/ml), indicating malignant transformation of the tumors. Under the diagnosis of LCAs and IHPSS, the patient underwent simultaneous resection of the four liver tumors and portovenous shunt, and the hepatic vascular abnormality was resolved. The pathological diagnosis was LCAs without hepatocellular carcinoma. Immunohistochemical analysis with an anti-PIVKA-II monoclonal antibody showed positive staining of the adenoma cells. This case shows that LCA without malignant transformation can produce PIVKA-II, leading to high serum levels of PIVKA-II. Simultaneous resection of multiple tumors and closure of the portosystemic shunt are strongly recommended in a patient with LCA associated with IHPSS.

Adenoma, Liver Cell↗
PubMed2006

[Case of hydrocephalus associated with vestibular schwannoma, treated by tumor removal].

A 57-year-old male presented with gait disturbance, urinary incontinence, dementia resembling symptom of normal pressure hydrocephalus (NPH) and was admitted to our institusion. A computerized tomographic scan (CT) and magnetic resonance imaging (MRI) revealed hydrocephalus as well as a tumor in the right cerebellopontine angle. We diagnosed communicating-type hydrocephalus associated with the vestibular schwannoma and tumor removal was performed prior to ventriculo-peritoneal (V-P) shunt. After surgery, symptoms of the patient disappeared promptly and cerebrospinal fluid protein elevation was normalized. One month after surgery, CT and MRI revealed reduction of the ventricle size and V-P shunt became unnecessary. Hydrocephalus is occasionally complicated by vestibular schwannoma. The majority results from obstruction of the cerebrospinal fluid (CSF) pathway by large tumors. But, small tumors also cause communicating-type hydrocephalus. Although the selection of the treatment is controversial, tumor removal without a shunt is considered as a good strategy for management of hydrocephalus associated with vestibular schwannoma.

Humans↗
PubMed2006

[Chronological changes in MR angiography of a case with isolated angiitis of the CNS].

Isolated angiitis of the central nervous system (IAC) is a disease of unknown etiology, and is restricted to the small-to-medium-sized blood vessels of the central nervous system. We report serial MR angiography findings in a case of IAC. A 51-year-old female came to our hospital because of severe headache. Computed tomography (CT) 6 days after the onset didn't show anything particular, and MR angiography 8 days after the onset revealed segmental stenosis of the bilateral anterior cerebral arteries. However, we couldn't diagnose it as IAC. Thirteen days after the onset, the patient's headache worsened. Subsequent MRA revealed severe stenosis of the bilateral anterior and middle cerebral arteries. After that, steroid therapy was initiated. Her headache was disappeared immediately. Twenty-nine days after the onset, MRA showed the improvement of stenosis. Seventy-three days after the onset, stenosis of the cerebral arteries was disappeared. Interestingly, in another case report of IAC, MRA showed improvement of the stenosis one month after the onset, and disappearance of the stenosis two months after the onset.

Female↗
PubMed2005

KL-6 mucin expression in carcinoma of the ampulla of Vater: association with cancer progression.

AIM: To assess histochemical expression of KL-6 and its clinicopathological significance in carcinoma of the ampulla of Vater. METHODS: Ampullary carcinoma tissues were collected from 38 patients who underwent pancreatoduodenectomy or local resection. Tissues were subjected to immunohistochemical analysis using KL-6 antibody. RESULTS: Positive staining of ampullary carcinoma cells was observed in 26 (68.4%) cases. Staining was not found in the surrounding non-cancer regions of the ampullary tissues. Remarkable KL-6 expression was observed in invasive carcinoma cells in pancreatic and duodenal tissues and in metastatic carcinoma cells in lymph nodes. Positive KL-6 expression was related to lymph node metastasis (P = 0.020), pancreatic invasion (P = 0.016), duodenal invasion (P = 0.034), and advanced stage of TNM clinical classification (P = 0.010). Survival analysis showed that positive expression of KL-6 was related to a poorer prognosis (P = 0.029). CONCLUSION: The aberrant expression of KL-6 mucin is significantly related to unfavorable behaviors of carcinoma of the ampulla of Vater.

Aged↗
PubMed2005

Volumetric quantitative analysis of tissue characteristics of coronary plaques after statin therapy using three-dimensional integrated backscatter intravascular ultrasound.

OBJECTIVES: The purpose of the present study was twofold: 1) to evaluate the usefulness of three-dimensional (3D) integrated backscatter (IB) intravascular ultrasound (IVUS) for quantitative tissue characterization of coronary plaques; and 2) to use this imaging technique to determine if six months of statin therapy alters the tissue characteristics of coronary plaques. BACKGROUND: Three-dimensional IVUS techniques for quantitative tissue characterization of plaque composition have not been developed. METHODS: Radiofrequency (RF) signals were obtained using an IVUS system with a 40-MHz catheter. The IB values of the RF signal were calculated and color-coded. The 3D reconstruction of the color-coded map was performed by computer software. A total of 18 IB IVUS images were captured at an interval of 1 mm in each plaque. A total of 52 patients with hyperlipidemia were randomized to treatment with pravastatin (20 mg/day, n = 17), atorvastatin (20 mg/day, n = 18), or diet (n = 17) for six months. The tissue characteristics of arterial plaque in each patient (one arterial segment per patient) were analyzed with 3D IB IVUS before and after treatment. RESULTS: Significant increases of fibrous volume (pravastatin: 25.4 +/- 6.5% to 28.1 +/- 6.1%; atorvastatin: 26.2 +/- 5.7% to 30.1 +/- 5.5%) and mixed lesion volume (atorvastatin: 25.5 +/- 6.6% to 28.7 +/- 5.1%) and a reduction of lipid volume (pravastatin: 25.5 +/- 5.7% to 21.9 +/- 5.3%; atorvastatin: 26.5 +/- 5.2% to 19.9 +/- 5.5%) were observed after statin therapy. CONCLUSIONS: Statin therapy reduced the lipid component in patients with stable angina without reducing the degree of stenosis. Three-dimensional IB IVUS offers the potential for quantitative volumetric tissue characterization of coronary atherosclerosis.

Aged↗
PubMed2005

Assessment of hepatic reserve for indication of hepatic resection: decision tree incorporating indocyanine green test.

Preoperative assessment of liver function and prediction of postoperative remaining functional liver parenchymal mass and reserve is of paramount importance to minimize surgical risk, especially in patients with hepatocellular carcinoma (HCC), the majority of whom have liver cirrhosis as a complication. We have established a decision tree for deciding the safe limit of hepatectomy based on three variables: whether ascites is present, the serum total bilirubin level, and the indocyanine green retention rate at 15 minutes (ICGR-15), an indicator of sinusoidal capillarization. In patients who show a sign of decompensated cirrhosis as reflected by an elevated bilirubin value or uncontrollable ascites, hepatectomy is not indicated. In patients without ascites and with normal bilirubin level, the ICGR-15 value becomes the main determinant for the resectability and hepatectomy procedure. Incorporation of ICGR-15 into the decision tree enables patients conventionally classified into Child-Turcotte-Pugh class A or score 5-6 to be subdivided into several groups in which various hepatectomy procedures are feasible: enucleation, limited resection, segmentectomy, mono- to bisectoriectomy, and trisectriectomy. During strict application of this decision tree to 1429 consecutive hepatectomies, of which 685 were performed on HCC patients, during the last 10 years, we encountered only a single mortality.

Ascites↗
PubMed2005

Prognostic impact of anatomic resection for hepatocellular carcinoma.

OBJECTIVES: To evaluate the prognostic impact of anatomic versus nonanatomic resection on the patients' survival after resection of a single hepatocellular carcinoma (HCC). SUMMARY OF BACKGROUND DATA: Anatomic resection is a reasonable treatment option for HCC; however, its clinical significance remains to be confirmed. METHODS: Curative hepatic resection was performed for a single HCC in 210 patients; the patients were classified into the anatomic resection (n = 156) and nonanatomic resection (n = 54) groups. In 84 patients assigned to the anatomic resection group, segmentectomy or subsegmentectomy was performed. We evaluated the outcome of anatomic resection, including segmentectomy and subsegmentectomy, in comparison with that of nonanatomic resection, by the multivariate analysis taking into consideration 14 other clinical factors. RESULTS: Both the 5-year overall survival and disease-free survival rates in the anatomic resection group were significantly better than those in the nonanatomic resection group (66% versus 35%, P = 0.01, and 34% versus 16%, P = 0.006, respectively). In the segmentectomy and subsegmentectomy group, the 5-year overall and disease-free survival rates were 67% and 28%, respectively, both of which were also higher than the corresponding rates in the nonanatomic resection group (P = 0.007 and P = 0.001, respectively). The results of multivariate analysis revealed that anatomic resection was a significantly favorable factor for overall and disease-free survivals: the hazard ratios were 0.57 (95% confidence interval, 0.32-0.99, P= 0.04), and 0.65 (0.43-0.96, P = 0.03). CONCLUSION: Anatomic resection for a single HCC yields more favorable results rather than nonanatomic resection.

Adolescent↗
PubMed2005

Ultrasonically assisted retrohepatic dissection for a liver hanging maneuver.

OBJECTIVE: To establish a safer and technically easier retrohepatic dissection for the liver hanging maneuver with the assistance of intraoperative ultrasound (IOUS). SUMMARY BACKGROUND DATA: The liver hanging maneuver described by Belghiti et al is an innovative suspending technique of the liver and is useful in difficult major right hepatectomies or in donor operations for living donor liver transplantation. The most important complication of this procedure is injury to the short hepatic veins and subsequent massive bleeding with an incidence of 4% to 6%. METHODS: After the cranial dissection of the suprahepatic inferior vena cava (IVC) between the middle and left hepatic veins, a long light curved Kelly clamp is inserted from the caudal edge behind the caudate lobe and passed cranially along the anterior midline of the IVC. On the midway of the dissection, the proper hepatic vein draining the caudate lobe (PrCV) is visualized. A safe dissection path is confirmed by IOUS, identifying the position of the clamp tip, PrCV, and the caudal end of the cranial retrohepatic dissection. When IOUS shows that the clamp tip has reached the caudal end of the cranial dissection, the operator can feel the clamp tip with his/her finger and the retrohepatic dissection is completed. RESULTS: From September 2003 to July 2004, 50 donor operations were performed for adult living donor liver transplantation. Retrohepatic dissection was feasible in 40 cases (80%). Of these, a US-assisted retrohepatic dissection was performed in 34 donors. PrCVs were visualized by IOUS in 48 donors (96%). The location of these PrCVs varied significantly (60 degrees -175 degrees from the right edge of IVC), and there were no distinct landmarks for identifying the location of PrCVs and safe dissecting course (55 degrees -130 degrees ). IOUS found that the dissecting clamp was heading to the PrCV in 3 cases and the direction of dissection was shifted to avoid injury. No substantial bleeding or no other complication related to retrohepatic dissection was encountered in any of the cases. CONCLUSIONS: With the aid of IOUS, the whole course of the blind dissection between the anterior surface of the IVC and the liver could be clearly visualized. IOUS could also identify the PrCV, the most dangerous point in the retrohepatic dissection.

Adult↗
PubMed2005

Tailoring the type of donor hepatectomy for adult living donor liver transplantation.

Donor hepatectomies for adult living donor liver transplantations were performed in 200 consecutive donors to harvest a left liver (LL) graft (n = 5), a LL plus caudate lobe (LL + CL) graft (n = 63), a right liver (RL) graft (n = 86), a RL and middle hepatic vein (RL + MHV) graft (n = 28) or a right lateral sector (RLS) graft (n = 18). The graft type was selected so that at least 40% of the recipient's standard liver volume was harvested. No donor deaths occurred, and no significant differences in the morbidity rates among either donors or recipients were observed when the outcomes were stratified according to the graft type. Donors who donated RL exhibited higher values of serum total bilirubin and prothrombin time than those who donated non-RL (LL, LL + CL, RLS) grafts. The time taken for hilar dissection and parenchymal transection increased in the following order: RLS graft, LL graft and RL graft harvesting. In conclusion, non-RL grafting was more time consuming, but the hepatic functional loss in the donors was smaller. Our graft selection criteria were useful for reducing the use of RL grafts with acceptable morbidity in both donors and recipients.

Adolescent↗
PubMed2005

Characterization of a small heat shock protein, Mx Hsp16.6, of Myxococcus xanthus.

A number of heat shock proteins in Myxococcus xanthus were previously identified by two-dimensional (2D) gel electrophoresis. One of these protein was termed Mx Hsp16.6, and the gene encoding Mx Hsp16.6 was isolated. Mx Hsp16.6 consists of 147 amino acid residues and has an estimated molecular weight of 16,642, in accordance with the apparent molecular mass in the 2D gel. An alpha-crystallin domain, typically conserved in small heat shock proteins, was found in Mx Hsp16.6. Mx Hsp16.6 was not detected during normal vegetative growth but was immediately induced after heat shock. Expression of the hsp16.6 gene was not induced by other stresses, such as starvation, oxidation, and high osmolarity. Mx Hsp16.6 was mostly localized in particles formed after heat shock and precipitated by low-speed centrifugation. Furthermore, Mx Hsp16.6 was detected in highly electron-dense particles in heat-shocked cells by immunoelectron microscopy, suggesting that it forms large complexes with heat-denatured proteins. An insertion mutation in the hsp16.6 gene resulted in lower viability during heat shock and lower acquired thermotolerance. Therefore, it is likely that Mx Hsp16.6 plays critical roles in the heat shock response in M. xanthus.

Amino Acid Sequence↗
PubMed2005

In vivo quantitative tissue characterization of angiographically normal coronary lesions and the relation with risk factors: a study using integrated backscatter intravascular ultrasound.

BACKGROUND: Autopsy studies have shown atherosclerotic changes in angiographically normal coronary lesions (ANCL), and conventional intravascular ultrasound shows intimal thickening in these lesions, but cannot differentiate the lipid core. Accurate characterization of ANCL is essential to prevent progression to coronary artery disease. METHODS AND RESULTS: ANCL (n=120) were analyzed by integrated backscatter intravascular ultrasound (IB-IVUS) in 30 patients with stable angina pectoris. Of the 120 arterial segments analyzed by IB-IVUS, 78 (65%) showed lipid cores of 0.69+/-0.35 mm2 with fibrous caps of 200+/-100 microm thick, 44 (37%) had intimal hyperplasia with a thickness of 350+/-100 microm, and 65 (54%) showed fibrosis in the intimal wall without lipid core with a thickness of 450+/-150 microm. The diabetes mellitus (DM) group (n=14) had significantly (p<0.05) bigger lipid cores (0.62+/-0.38 mm2) and thinner intimal hyperplasia (100+/-100 microm) compared with the non-DM group (0.31+/-0.33 mm2, 150+/-150 microm, respectively). The hypertension (HT) group (n=23) had significantly more intimal hyperplasia (150+/-150 microm) compared with the non-HT group (50+/-100 microm). Hyperlipidemia (n=16) or smoking (n=6) did not significantly affect tissue characteristics. CONCLUSION: IB-IVUS showed various types of plaque in ANCL and the plaque characteristics were affected by DM and HT. The results provide new clinical insight into the early stage of human coronary atherosclerosis.

Aged↗
PubMed2005

Des-gamma-carboxyprothrombin expression in cancer and/or non-cancer liver tissues: association with survival of patients with resectable hepatocellular carcinoma.

Des-gamma-carboxyprothrombin (DCP), also known as a protein induced by vitamin K absence or antagonist II, is an abnormal prothrombin. The level of serum DCP is used in clinical diagnosis and prognosis of patients with hepatocellular carcinoma (HCC). Our previous immunohistochemical study showed that DCP is expressed not only in cancer tissues but also in the surrounding non-cancer tissues of HCC patients. However, clinical significance of DCP expression in non-cancer tissues of HCC patients remains unclear. In this study, we examined the relationship between histochemical expression of DCP in cancer and/or non-cancer tissues and the clinical outcome of the HCC patients. A retrospective study was performed of 132 patients each with a single primary HCC nodule. Expression of DCP in tissues was evaluated with immunohistochemical staining using anti-DCP antibody (MU-3). Serum DCP levels were determined using enzyme immunoassay with a double antibody sandwich system. Experimental and clinical data were processed by univariate and multivariate statistical analyses. DCP expression, even if it was observed only in non-cancer tissues, was related to poorer prognosis. Univariate and multivariate analyses showed that DCP expression in cancer and/or non-cancer tissues was a significant prognostic factor. Furthermore, the combined evaluation of tissue DCP expression and serum DCP levels showed that prognosis was poorest for patients showing positive tissue DCP expression and high levels of serum DCP. These results suggest that immunohistochemical evaluation of DCP expression not only in cancer but also in non-cancer tissues serves as a valuable factor in the prognosis of HCC patients and that the combined evaluation of tissue DCP expression and serum DCP level will be more valuable than either factor alone in the effective treatment and prognosis.

Adolescent↗
PubMed2005

[A case of spinal dural arteriovenous fistula draining to the ventral coronal venous plexus].

Here we report a case of spinal dural areteriovenous fistula (AVF) draining to the anterior spinal vein. An 80-year-old female presented with progressive weakness of lower extremities. MRI showed spinal enlargement at the Th10 to L1 with high intensity signals on T2-weighted image and multiple flow voids on the dorsal and ventral surface of the spinal cord. Angiogram of the left L2 lumbar artery demonstrated a hairpin-shaped vessel with ascending and descending limbs, mimicking radiculomedullary artery. Oblique view angiogram of the left L2 lumbar artery showed that radiculomedullary vein drained to the dilated anterior spinal vein, which then drained cranially and caudally on the anterior and posterior surface of the spinal cord. The patient underwent T9-L2 laminectomy. Several large tortuous dilated veins in the subarachnoid space were found. Examination of the inner surface of the dura revealed an arterialized vein that began at the level of L2 and coursed superiorly. The arterialized vein was coagulated and interrupted. The postoperative angiogram demonstrated the obliteration of the fistula. Postoperative MRI returned to normal with complete disappearance of T2 high signal, cord enlargement. In most spinal dural AVF, the venous drainage is predominantly upward on the posterior surface of the spinal cord. The spinal dural AVF draining to the anterior spinal vein is atypical, and cause difficulty in differentiating the anterior spinal artery from the anterior spinal vein. Oblique view angiogram may be helpful to differentiate the anterior spinal vein from anterior spinal artery.

Aged↗
PubMed2004

Duct-to-duct biliary reconstruction in adult living-donor liver transplantation.

BACKGROUND: Bile duct-to-duct reconstruction is now used in living-donor liver transplantation (LDLT) for adult patients. METHODS: The results of duct-to-duct reconstruction were retrospectively analyzed. The subjects were 81 adult patients who underwent LDLT at the University of Tokyo Hospital with a follow-up period of at least 1 year. The hilar plate of the recipient was dissected to at least the second-order branch of the bile ducts. Duct-to-duct anastomosis was performed with interrupted sutures, and an external stent tube was inserted from the orifice opposite the hilar plate. RESULTS: During the observation period (median, 664 days), biliary complications were observed in 26 cases (32%). The complications included bile juice leakage at the anastomosis or dissection plane of the graft in 12 patients, anastomotic stenosis in 10 patients, and tube trouble in 6 patients. Two patients had bile juice leakage followed by stenosis. Of the 26 patients, 21 required surgical revision. CONCLUSIONS: The current technique did not reduce morbidity as expected. Further technical advancement and refinement are needed for better results.

Adult↗