Search PubMed⌕ Search

Biomedical subjects

M Sakamoto

Publications and source records attributed to M Sakamoto.

964 records · Page 54Linked to original sources

Effect of pentoxifylline on sperm motion.

The ability of pentoxifylline to stimulate sperm motility characteristics was assessed. The effect of pentoxifylline was immediate and lasted for 240 min. The percent motility was increased 1.5-fold when compared with the control at 120, 180, and 240 min after pentoxifylline treatment. Significant increases in velocity and amplitude of lateral head displacement by the agent were observed at 120 min after the start of incubation. Conversely, linearity was reduced by pentoxifylline. Beat-cross frequency did not show any significant change by the agent at any time point. Sperm swelling was not influenced by pentoxifylline throughout the experiment. It would appear that pentoxifylline stimulates sperm motion in vitro with no change of the sperm membrane.

Humans↗

Changes in seminal plasma transferrin concentration following administration of clomiphene citrate.

This study was designed to investigate the functional changes in Sertoli cells following clomiphene citrate administration to patients with idiopathic infertility. The agent was administered to 44 oligozoospermic patients. Patients with improvement in sperm concentration after treatment (improvement group) showed significantly lower pretreatment follicle-stimulating hormone (FSH) levels in serum. Serum FSH and testosterone levels significantly increased in the improvement group after treatment (both p < 0.05). Seminal transferrin concentration significantly increased in the improvement group after treatment (p < 0.05), although there was no significant difference between pretreatment seminal transferrin concentration in the improvement group and that in patients with no improvement in sperm concentration. Seminal plasma transferrin concentration in patients in whom pretreatment luteinizing hormone level in serum was below 10 mIU/mL, and in those in whom the ratio of post- to pretreatment values was 1.5 or more, tended to increase after treatment. This group also contained a few more patients with improvement in sperm concentration than the other groups. The patients showing low pretreatment FSH levels and a high ratio of post- to pretreatment values demonstrated a significant increase in seminal plasma transferrin concentration after treatment (p < 0.01), and this group contained more patients with improvement than the other groups. It would appear that Sertoli cell stimulation may induce an increase in sperm concentration after clomiphene citrate administration, and the elevated transferrin secretion seems to be associated with the increase of serum FSH level after treatment.

Adult↗

Acrobeads test using monoclonal antibody-coated immunobeads: clinical application.

Acrosome-reacted sperm was examined in infertile and fertile males using the Acrobeads test. The Acrobeads score was significantly higher in fertile males than in infertile males with normal or abnormal seminal findings (p < .005 and p < .001, respectively). The Acrobeads score was 2 or more in all the fertile males, but 62% of the infertile males with abnormal seminal findings (p < .02). Therefore, a disturbance in the acrosome reaction is suggested to be one of the causes of decreased fertility potential. A high correlation was found between Acrobeads score and sperm motility (r = .46, p < .001) or motile sperm concentration (r = .51, p < .0001). The Acrobeads test, the results of which reflect the acrosome condition of the sperm, is useful in the assessment of sperm function related to fertility.

Acrosome↗

Telomerase activity in gynecological tumors.

The aim of this study was to define the clinical implications of semi-quantitative telomerase activity in gynecological tumors by comparing the telomerase activity of cancerous lesion and the adjacent non-cancerous lesion. In 118 cases of gynecologic tumors, including 41 uterine cervical tumors, 43 uterine body tumors and 34 ovarian tumors, telomerase activities were determined using TRAPeze telomerase detection kit for the extension reaction of the telomere sequence and the PCR reaction for amplification of the sequence, and using fluorecence-based telomere repeat amplification protocol (F-TRAP) method for the detection. In all gynecologic cancers examined, telomerase activity of the cancerous lesion was significantly higher than that of the non-cancerous lesion. Telomerase activity in the uterine cervix increased in the following order of the normal uterine cervix, cervical dysplasia and cervical cancer. Regarding the endometrial cancer, telomerase activity at the primary lesion in patients with lymph node metastases was significantly higher than that in patients without lymph node metastases. When telomerase activity was compared by histologic subtypes of the ovarian cancer, clear cell adenocarcinoma showed significantly lower telomerase activity than the other subtypes, especially endometrioid adenocarcinoma. In all gynecologic cancers examined, there was no clear correlation between the telomerase activity and age at diagnosis or age of menopause. Although all tumors with 100 units or more telomerase activity were cancerous, the sensitivity was 39% in cervical cancer, 41% in endometrial cancer and 21% in ovarian cancer, respectively. Cervical intraepithelial neoplasia (CIN) had already increased telomerase activity and endometrial cancer with lymph node metastases had also greater activity than that without lymph node metastases. Although telomerase activity in ovarian cancer tended to increase as stage advances, it is noteworthy that clear cell adenocarcinoma showed significantly lower telomerase activity than endometrioid adenocarcinoma.

Cervix Uteri↗

Prognosis of hepatocellular carcinoma with no tumor stain treated by percutaneous ethanol injection.

BACKGROUND/AIMS: Some hepatocellular carcinoma nodules do not show tumor stain by hepatic angiography or enhanced computed tomography. The aim of this study was to clarify the prognosis of hepatocellular carcinoma with no tumor stain treated by percutaneous ethanol injection. METHODOLOGY: Twenty patients who had hepatocellular carcinoma with no tumor stain were treated by percutaneous ethanol injection between January 1990 and June 1998. No patients had received any anticancer treatments before percutaneous ethanol injection. Recurrence-free survival, predictive factors for recurrence and recurrent patterns were examined. Overall survival was also examined. RESULTS: Ten of the 20 patients showed intrahepatic recurrences in other parts of the treated lesions, although no local recurrence was observed. Median recurrence-free survival time, 1-, 3- and 5-year recurrence-free survival rates were 2.8 years, 66%, 43% and 22%, respectively. A serum alpha-fetoprotein level of 20 ng/mL or less was the only factor that was significantly associated with prolonged recurrence-free survival. Of the 12 recurrent nodules in 10 patients, 9 occurred in different segments of the treated lesion and 8 were histopathologically confirmed to be well-differentiated hepatocellular carcinoma. Overall survival rates 1, 3, and 5 years after percutaneous ethanol injection were 100%, 82%, and 75%, respectively. CONCLUSIONS: Percutaneous ethanol injection may be useful for the treatment of hepatocellular carcinoma with no tumor stain.

Aged↗

Optimal timing for application of ventricular assist devices in patients who cannot be weaned from cardiopulmonary bypass. An experimental study.

Missing the moment for application of ventricular assist devices (VAD) may be one of the major causes of multiple organ failure in patients who are to be weaned from cardiopulmonary bypass (CPB) with the aid of VAD. To determine the optimal timing for application of VAD in such patients, we examined the effect of a CPB assist on cardiac functional recovery from severe global ischemia using an experimental canine system. In the present study we created myocardial ischemia by clamping the aorta for 20 minutes (Group I; N = 7) or 45 minutes (Group II; N = 11) under normothermic CPB. The reliability of the method in creating severe cardiac failure was confirmed by testing the levels of adenosine triphosphate (ATP), creatine phosphate (CP), and lactate. After reperfusion of the myocardium, the heart was assisted by a totally vented CPB. The left ventricular end-systolic pressure-volume relationship (Emax), which is a load-independent index of contractility, was obtained every 15 minutes for up to 120 minutes of reperfusion. The Emax revealed that the function of the damaged heart recovers exponentially with time after reperfusion. From curves of the functional recovery of the heart, CPB support appeared to be beneficial for the first 60 minutes after reperfusion, and aided in the recovery of cardiac function in hearts damaged by global myocardial ischemia. However, CPB assist thereafter may not be effective in further improving cardiac function. We therefore concluded that the decision to use VAD should be determined by cardiac function by 60 minutes of reperfusion to avoid prolonging CPB time.

Adenosine Triphosphate↗

Intrahepatic cholangiocarcinoma presenting intrabile duct tumor growth: report of a case.

A case of intrahepatic cholangiocarcinoma with intrabile duct tumor growth is presented. A 70-year-old female with prolonged obstructive jaundice and cholangitis was diagnosed with a mass lesion in the left lobe of the liver accompanied by an intrabile duct component which caused hilar bile duct obstruction. Percutaneous transhepatic biliary drainage (PTBD) was performed via three routes with intensive care of the drainage catheters over a 2-month period to alleviate jaundice and cholangitis. Extended left hepatic lobectomy with combined resection of extrahepatic bile duct and regional lymph nodes were carried out curatively. Macroscopically, a tumor formed a 8 x 6 cm mass with a scalloped margin in the left lobe and had an intraductal component with a round smooth surface protruding from the lumen of the left hepatic duct into the common bile duct. The histologic type of the tumor was well differentiated tubular adenocarcinoma. The intraluminal tumor grew expansively without invasion to the bile duct wall. The postoperative course was uneventful and the patient has remained in good health without recurrence for 1 year and 3 months since surgery. This case report discusses a rare extension pattern in ICC and the management of malignant hilar obstruction during radical surgery.

Aged↗

Influence of alcohol abuse on recurrence after curative resection of hepatocellular carcinoma.

BACKGROUND/AIM: We studied the influence of alcohol abuse (ethanol intake > 80 gm/day for > 5 yr.) on recurrence in 81 patients with hepatocellular carcinoma who had undergone curative hepatic resection. Twenty-nine patients were positive for alcohol abuse [AA(+)] and 52 were not [AA(-)]. RESULTS: Recurrence of carcinoma within 2 and 27 postoperative months was observed in 45 (55.6%) of the 81 patients. The median disease-recurrence time was 12.0 mo in the AA(+) group and 24.1 mo in the AA(-) group (p<0.01). The patterns of recurrence were classified into the following 4 types: single-nodular type (intrahepatic single nodule); multi-nodular type (intrahepatic multiple nodules); whole liver type (diffuse recurrence over the whole remnant liver); and extrahepatic type (extrahepatic recurrence alone). Five (29.4%) of the 17 patients with recurrence in the AA(+) group demonstrated the whole liver type, compared with only 2(7.1%) of the 28 patients in the AA(-) group (p<0.05). CONCLUSION: Patients with alcohol abuse should be followed up particularly closely, even if they have received curative surgery, since alcohol abuse is strongly related to postoperative recurrence.

Alcoholism↗

The prognosis of patients with hepatocellular carcinoma of multicentric origin.

BACKGROUND/AIMS: The characteristics of patients with multicentric hepatocellular carcinoma (HCC) differ from those of patients with intrahepatic metastatic HCC. However, there are few reports regarding the long-term results in patients with HCC of multicentric occurrence. The purpose of this study was to clarify the prognosis of a group of patients with multicentric HCCs. MATERIALS AND METHODS: We evaluated the outcome in 28 patients with multiple hepatocellular carcinoma (HCC) suggestive of multicentric occurrence, all of whom underwent hepatic resection. The disease-free survival, recurrence pattern and survival were analyzed in the two subgroups of 12 patients with single advanced HCC (AdHCC) nodule and an early HCC (eHCC) or early advanced HCC (eAdHCC) nodule [Group A] and 16 patients with two AdHCC lesions [Group B]. These data were also compared with those of 58 patients with solitary AdHCC [Group C]. RESULTS: Both the disease-free survival and survival periods for Groups A and C were significantly longer than those for Group B, while no significant difference was seen between Group A and C. No significant differences among the three groups were recognized in the incidence of various types of recurrence pattern. CONCLUSIONS: The long-term results in patients with multicentric HCC apparently vary depending on the pathological condition at the time of operation. Among patients with multicentric HCC, those with AdHCC combined with an eHCC or eAdHCC are likely to show improved prognosis as a result of hepatic resection.

Carcinoma, Hepatocellular↗

Imaging of large early and early advanced hepatocellular carcinomas of more than 5 cm in diameter: report of two cases.

In an attempt to clarify the imaging characteristics of large early and early advanced hepatocellular carcinoma (HCC), we present two such cases which were greater than 5 cm in diameter. One case had four early HCCs and the other had early advanced HCC which was followed for five years and nine months. Multiphasic CT, CT arteriography (CTA), CT arterial portography (CTAP), and MR imaging were performed. Early HCC was shown as a low density mass by multiphasic contrast CT, CTAP and as a hyperintense mass on a T1-weighted image (WI) and isointense on T2WI. Early advanced HCC was demonstrated as a hypodense mass with hyperenhancing interior nodules on CTA, and isodense with hypodense internal foci on CTAP. One follow-up case showed a multi-step progression from early to early advanced HCC, and finally to overtly advanced HCC. Despite the unusually large size of these two tumors, the findings of multiphasic CT, CTA, CTAP, and MR imaging were consistent with those seen in common-sized (less than 2 cm) early and early advanced HCCs. Multi-step progression of hepatocarcinogenesis was observed in one case.

Aged↗