Search PubMed⌕ Search

Biomedical subjects

K Seki

Publications and source records attributed to K Seki.

At least 55 records · Page 3Linked to original sources
PubMed2001

Subsequent pregnancy outcome in patients with spontaneous resolution of HCG after evacuation of hydatidiform mole: comparison between complete and partial mole.

This study compared subsequent pregnancy outcome in patients with complete and partial hydatidiform moles. Among 1052 patients with molar pregnancy (complete mole, 801; partial mole, 251) monitored at Chiba University Hospital between 1981 and 1999, 891 patients (84.7%) had spontaneous resolution of human chorionic gonadotrophin (HCG) after mole evacuation, and 161 patients (15.3%) required chemotherapy. Of the 891 patients, 438 (49.2%) had 650 subsequent pregnancies. The pregnancy outcome was not significantly different in patients with complete and partial moles, and was comparable with that in the general Japanese population. The incidence of repeat molar pregnancy in patients with complete and partial mole (1.3 and 1.5% respectively) was 5-fold higher than that of the general population, while no increased risk of persistent gestational trophoblastic tumour (GTT) associated with later molar pregnancy was observed. During HCG follow-up, 10 patients (1.1%) developed secondary high-risk GTT between 14 and 54 months after mole evacuation. The incidence of high-risk GTT in patients with and without subsequent pregnancies was 0.46% (2/438) and 1.8% (8/453) respectively (P = 0.1243). In conclusion, patients with complete and partial mole can anticipate a normal future reproductive outcome, and pregnancies after experiencing hydatidiform mole may not affect the development of high-risk GTT.

Adolescent↗
PubMed2001

Accuracy of Digora system in detecting artificial peri-implant bone defects.

This study was done to compare the diagnostic accuracy in detecting simulated intrabony defects around fixtures using Digora (DIG; Sordex Orion Corporation, Helsinki, Finland) compared with Ektaspeed Plus film (PLS; Eastman Kodak Co., Rochester, NY). Three titanium implant fixtures were placed in molar areas of three cadavers. Bone defects were created in the interproximal alveolar crest. Exposure time was adjusted to a PLS film and reduced to 1/5 only for DIG (1/5 DIG). The results of four observers were assessed. Sensitivity, specificity, accuracy, and under the receiver operator characteristic curve (ROC) area were evaluated. Statistical analyses were performed by using Friedman test and one-way ANOVA test. Mean sensitivity/specificity were 0.60/0.85 (DIG), 0.54/0.81 (1/5 DIG), and 0.64/0.58 (PLS). There were no statistically significant differences in the diagnostic accuracies. Digora had an equivalent performance to radiographic film in detecting intrabony defects adjacent to the implants, notwithstanding the amount of 1/5 of the exposure time.

Alveolar Bone Loss↗
PubMed2001

Influence of timing and magnitude of arterial wave reflection on left ventricular relaxation.

The influence of timing and magnitude of arterial wave reflection (WR) on afterload-dependent relaxation was evaluated in patients with a variety of heart diseases (group 1, age < 30 yr; group 2, age > 40 yr) and in dogs. While both femoral arteries were compressed (FC), WR returned just after the dicrotic notch (early diastole) in group 1 but before the dicrotic notch (late systole) in group 2. The time constant of the left ventricular pressure decay (tau) was shortened during FC in group 1, whereas it was prolonged in group 2. In dogs, a constriction of the thoracic aorta induced a late systolic augmentation of WR with a prolongation of tau (cf. group 2), whereas constriction of the lower abdominal aorta induced an early diastolic augmentation of WR with a shortening of tau (cf. group 1). With aortic constriction, coronary flow increased, and there was a close correlation between the peak change in backward aortic pressure and that in coronary flow regardless of the timing of WR. Thus the time at which WR returns during the cardiac cycle may have an important effect on left ventricular relaxation and coronary flow.

Adult↗
PubMed2001

Acid-catalyzed photoreaction of 6-chloro-1,3-dimethyluracil and mesitylene: formation of photocycloadducts and their characterization.

In contrast to the previously reported short time required (1 h) for photolysis of 6-chloro-1,3-dimethyluracil (6-CIDMU) and mesitylene, in the presence of TFA, resulting in two major products: 1,3,6,8,10-pentamethylcyclooctapyrimidine derivative (1d), and diazapentacyclo[6.4.0.0(1,3).0(2,5).0(4,8)]dodecane (2c), prolonged irradiation (18h) of this same mixture yields novel pentalenopyrimidine derivatives, including diazapentacyclo[6.4.0.0(1,3).0(2,6).0(4,8)]dodecane (3c).

Acids↗
PubMed2001

Purification and properties of two malate dehydrogenases from Candida sp. N-16 grown on methanol.

Two malate dehydrogenases (MDH-M1 and MDH-M2) were found in a methanol-using yeast, Candida sp. N-16. MDH-M2 was induced with methanol. These enzymes were purified as electrophoretically and isoelectrophoretically homogeneous proteins. The molecular weights of MDH-M1 and MDH-M2 were estimated to be about 78,000 (homodimer) and 160,000 (homotetramer). Several kinetic properties were significantly different between the two enzymes. The value (2.07) of Vmax(oxaloacetate)/Vmax(malate) and Kcats (555 s(-1) for oxaloacetate, 481 s(-1) for NADH) of MDH-M2 were higher than the ratio (1.37) of Vmax and Kcats (241 s(-1) for oxaloacetate, 271 s(-1) for NADH) of MDH-M1, respectively. The activity of MDH-M2 was inhibited by a high concentration of NAD+ and the activity of MDH-M1 by oxaloacetate.

Candida↗
PubMed2001

Electrocyclic rearrangement of pentamethylcyclooctapyrimidine-2,4-diones: reaction pathway into a 9,11-diazapentacyclo-[6.4.0.0(1,3).0(2,5).0(4,8)]dodecane system and a 9,11-diazapentacyclo [6.4.0.0(1,3).0(2,6).0(4,8)]dodecane system.

Photolysis of 6-chloro-1,3-dimethyluracil and mesitylene in the presence of trifluoroacetic acid (TFA) at low temperature gave 1,3,5,7,9- and 1,3,6,8,10-pentamethylcyclooctapyrimidine-2,4-diones (1b, 1c). Sequential photoreaction of the former (1b) resulted in the formation of 9,11-diazapentacyclo[6.4.0.0(1,3).0(2,5).0(4,8)]dodecane-2,4-dione (2b) by way of 9-exo-methylene derivative (7b) and cyclobutaquinazoline (8b). On the other hand, UV-irradiation of 1c led to the bond shift isomer (5c) whose photolysis in the presence of TFA gave rise to the formation of the [6.4.0.0(1,3).0(2,6).0(4,8)]dodecane isomer (3c).

Journal Article↗
PubMed2001

[A case of crossed aphasia with echolalia after the resection of tumor in the right medial frontal lobe].

We report a right-handed woman, who developed a non-fluent aphasia after resection of astrocytoma (grade III) in the right medial frontal lobe. On admission to the rehabilitation department, neurological examination revealed mild left hemiparesis, hyperreflexia on the left side and grasp reflex on the left hand. Neuropsychologically she showed general inattention, non-fluent aphasia, acalculia, constructional disability, and mild buccofacial apraxia. No other apraxia, unilateral spatial neglect or extinction phenomena were observed. An MRI demonstrated resected areas in the right superior frontal gyrus, subcortical region in the right middle frontal gyrus, anterior part of the cingulate gyrus, a part of supplementary motor area. Surrounding area in the right frontal lobe showed diffuse signal change. She demonstrated non-fluent aprosodic speech with word finding difficulty. No phonemic paraphasia, or anarthria was observed. Auditory comprehension was fair with some difficulty in comprehending complex commands. Naming was good, but verbal fluency tests for a category or phonemic cuing was severely impaired. She could repeat words but not sentences. Reading comprehension was disturbed by semantic paralexia and writing words was poor for both Kana (syllabogram) and Kanji(logogram) characters. A significant feature of her speech was mitigated echolalia. In both free conversation and examination setting, she often repeated phrases spoken to her which she used to start her speech. In addition, she repeated words spoken to others which were totally irrelevant to her conversation. She was aware of her echoing, which always embarrassed her. She described her echolalic tendency as a great nuisance. However, once echoing being forbidden, she could not initiate her speech and made incorrect responses after long delay. Thus, her compulsive echolalia helped to start her speech. Only four patients with crossed aphasia demonstrated echolalia in the literature. They showed severe aphasia with markedly decreased speech and severe comprehension deficit. A patient with a similar lesion in the right medial frontal lobe had aspontaneity in general and language function per se could not be examined properly. Echolalia related to the medial frontal lesion in the language dominant hemisphere was described as a compulsive speech response, because some other 'echoing' phenomena or compulsive behavior were also observed in these patients. On the other hand, some patients with a large lesion in the right hemisphere tended to respond to stimuli directed to other patients, so called 'response-to-next-patient-stimulation'. This behavior was explained by disinhibited shift of attention or perseveration of the set. Both compulsive speech responses and 'response-to-next-patient-stimulation' like phenomena may have contributed to the echolalia phenomena of the present case.

Adult↗
PubMed2001

Diagnosis of pancreatic adenocarcinoma by detection of human telomerase reverse transcriptase messenger RNA in pancreatic juice with sample qualification.

PURPOSE: We evaluated the diagnostic efficacy of detection of human telomerase reverse transcriptase (hTERT) message, a catalytic domain of human telomerase, in endoscopic retrograde pancreatography (ERP)-derived pancreatic juice. EXPERIMENTAL DESIGN: Both hTERT and CD25 expression were detected by reverse transcription-PCR (RT-PCR) in 17 patients with pancreatic adenocarcinoma (PC), 12 patients with chronic pancreatitis (CP), and 7 patients with no ERP abnormality (N). In the same patients, beta-actin message was semiquantified by competitive RT-PCR. K-ras codon 12 mutations were concomitantly analyzed by enriched PCR-SSCP in 11 and 7 PC and CP cases, respectively. RESULTS: Expression of hTERT was detected in 88% of PC cases and 17% of CP cases but not in the normal control (N). Alterations in K-ras were detected in 73% of PC cases and 57% of CP cases, respectively. beta-Actin mRNA was expressed in >3.0 x 10(1) copies/microl in all but two PC cases in which hTERT mRNA was not detected. CD25-positive and -negative peripheral lymphocytes were isolated from a normal volunteer using a fluorescent activating cell sorter. The hTERT message was detected in CD25-positive peripheral lymphocytes and in 18, 25, and 0% of the pancreatic juice samples from PC, CP, and N cases, respectively. All CP cases expressing hTERT message were also CD25 positive. CONCLUSIONS: These results suggest that detection of hTERT mRNA in pancreatic juice is a powerful tool to discriminate PC from CP, particularly when the samples are qualified against beta-actin mRNA levels and contaminating CD25-positive lymphocytes.

Actins↗
PubMed2001

[Cavernous sinus dural arteriovenous shunt presenting with subarachnoid hemorrhage and acute subdural hematoma: a case report].

Cavernous sinus dural arteriovenous shunt (CdAVS) usually presents with exophthalmos, conjunctival chemosis, ophthalmoplegia, headache, bruit, or pulsatile tinnitus. Intracranial hemorrhage associated with CdAVS is rare. We describe a patient with CdAVS presenting with subarachnoid hemorrhage and acute subdural hematoma. A 65-year-old woman presented headache and temporary loss of consciousness and was transferred to our hospital. On admission, the patient was alert and complained of a left-sided temporal headache. There were no ocular symptoms. A CT scan revealed subarachnoid hemorrhage and left acute subdural hematoma. When we prepared for cerebral angiography, the patient presented loss of consciousness following sudden onset of severe headache. Urgent angiography revealed left CdAVS, which was fed by both the internal carotid artery and the external carotid artery and drained only into ipsilateral (left) vein of the sylvian fissure. Aneurysmal dilatation of the draining veins and leptomeningeal drainage were present. No cerebral aneurysms were detected. After the angiography, a CT scan showed enlarged subdural hematoma, so left fronto-temporo-parietal craniotomy was immediately performed. On opening the dura mater, arterial bleeding from Sylvian fissure appeared and was uncontrollable. Unfortunately, the patient died 3 days after the operation. We concluded that subarachnoid hemorrhage and subdural hematoma were due to the rupture of engorged cortical veins. Our case report suggests that CdAVS with angiographic findings such as aneurysmal dilatation of the draining veins and leptomeningeal drainage should be treated urgently because of the high risk of the life-threatening complications resulting from a surgically uncontrollable hemorrhage.

Aged↗
PubMed2000

Unilateral spatial neglect in AD: significance of line bisection performance.

BACKGROUND: Unilateral spatial neglect has been rarely reported in patients with AD, although they often have right and left asymmetry of temporoparietal dysfunction. OBJECTIVE: To investigate if patients with AD would show unilateral spatial neglect in the line bisection test, and to reveal the relationship between their neglect and the area of cerebral dysfunction. METHOD: Thirty-two patients with mild to moderate AD and 32 age-matched healthy control subjects underwent an extensive line bisection test. SPECT was also obtained for the patients. RESULTS: Rightward bisection errors exceeded the normal range in 25% of patients with AD. They exhibited greater rightward errors for the longer lines in the left hemispace than in the right hemispace, and with the right hand than with the left hand; this corresponds to the characteristics of neglect seen after right hemisphere lesions. All patients who bisected 200 mm lines with errors over 10 mm showed disproportionate lowering of performance IQ and asymmetric right hemisphere hypoperfusion, especially in the temporoparietal region. Seventy-five percent of the patients performed normally in the center presentation but erred slightly toward the body midline in the right and left hemispaces. CONCLUSION: Left unilateral spatial neglect in mild to moderate AD may be rather common if tested with the line bisection test. Rightward errors over 10 mm suggest right temporoparietal dysfunction. In AD, three or more bisections of 200 mm lines in the center presentation are recommended for detection of neglect. Patients with AD but without neglect may have difficulty in shifting attention into the peripheral sector of the egocentric space.

Aged↗
PubMed2000

Human papillomavirus-positive well-differentiated villoglandular adenocarcinoma of the uterine cervix: A case report and review of the literature.

OBJECTIVE: A case of well-differentiated villoglandular adenocarcinoma of the uterine cervix, which was positive for human papillomavirus type 18, was reported. METHODS: The patient was a 52-year-old multipara who was referred to our department because of an abnormal Papanicolaou smear. A 4.0-cm exophytic lesion involving the cervix was detected. She was staged as FIGO IIa and radical hysterectomy combined with bilateral pelvic lymphadenectomy was performed. In addition to histopathological examination of the resected tumor, immunohistochemical studies of estrogen and progesterone receptors were performed using monoclonal antibodies. Detection of human papillomavirus DNA was attempted by polymerase chain reaction using consensus primers. RESULTS: The tumor was a typical well-differentiated villoglandular adenocarcinoma involving the vaginal wall. Both estrogen and progesterone receptors were negative. Human papillomavirus type 18 DNA was detected in the resected tumor. CONCLUSION: 'This is the first report of a case of typical well-differentiated villoglandular adenocarcinoma which was positive for human papillomavirus.

Adenocarcinoma↗
PubMed2000

Combination chemotherapy with methotrexate, etoposide, and actinomycin D for high-risk gestational trophoblastic tumors.

OBJECTIVES: The goal of this study was to evaluate the efficacy, toxicity, and survival of patients with high-risk gestational trophoblastic tumors (GTTs) treated with a methotrexate-etoposide-actinomycin D (MEA) regimen without cyclosphosphamide or vincristine. METHODS: Thirty-nine consecutive patients with high-risk GTTs (28 were defined high risk by WHO criteria) were treated with primarily the MEA regimen. Among them, 27 patients had received no prior chemotherapy and 12 had received prior chemotherapy. Survival, causes of treatment failure, and toxicity were analyzed retrospectively. RESULTS: After treatment with the MEA regimen, 29 of 39 patients achieved primary remission (74.4%), 8 developed resistance (20.5%), and 2 died of widespread metastases and chemotherapy-related toxicity. All 8 patients who developed resistance were treated with high-dose 5-fluorouracil and actinomycin D (FA); 6 were salvaged and 2 died of refractory disease. Three patients relapsed; 2 were controlled with FA or cisplatin-based chemotherapy and 1 who refused further treatment died. The disease-free survival rate was 87%. WHO grade 4 leukocytopenia and thrombocytopenia with the MEA regimen occurred in 5.3 and 6.4%, respectively, of the cycles; other toxic effects were acceptable and manageable. CONCLUSIONS: At present, MEA chemotherapy (without cyclophosphamide or vincristine) is our treatment of choice for patients with high-risk GTT. Its toxicity is predictable and manageable. For patients who become resistant to MEA, new salvage chemotherapy regimens are needed.

Adult↗
PubMed2000

Cisplatin (CDDP) specifically induces apoptosis via sequential activation of caspase-8, -3 and -6 in osteosarcoma.

PURPOSE: Osteosarcoma is a common malignant tumor. The first choice of treatment plan for osteosarcoma is chemotherapy. In particular, preoperative chemotherapy is most important in clinical treatment in orthopedics. In these chemotherapies, multiple anticancer drugs such as Adriamycin (ADM), CDDP, cyclophosphamide (CPM), methotrexate (MTX) and vincristine (VCR) are commonly used in combination. Recently, anticancer drugs have been shown to trigger apoptosis in various cancer cells. However, many studies on this topic have been examined using leukemia cell lines, and many kinds of cancer cells established from solid tumor are resistant to the induction of apoptosis by anticancer drugs. So in this study, we examined the effects of the anticancer drugs ADM, CDDP, CPM, MTX and VCR on osteosarcoma cells in vitro. We also examined the signaling pathways of each anticancer drug by studying the induction of apoptosis and activation of caspases in the osteosarcoma cells. METHODS: We examined the effects of the anticancer drugs ADM, CDDP, CPM, MTX and VCR, which are used clinically for the treatment of osteosarcoma, on cells of the human osteosarcoma (HOS) cell line. The cytotoxic effects of the anticancer drugs were evaluated using the MTT assay. We used both flow cytometry and activation of caspases to confirm the induction of apoptosis in the HOS cells. To dissect the pathway of the caspase cascade in apoptosis in HOS cells, we used the tetrapeptides YVAD-CHO, DMQD-CHO, VEID-CHO and IETD-CHO, which selectively inhibit caspase-1, -3, -6 and -8, respectively. RESULTS: ADM, CDDP, CPM and VCR, but not MTX, induced death of HOS cells in a dose-dependent manner. CDDP at 10 microM, CPM at 7.5 microM, ADM at 20 microM and VCR at 150 microM caused 80% cell death of HOS cells after 12 h. However, the percentages of apoptotic cells were 5.6% (medium alone), 75.9% (CDDP), 20.0% (CPM), 22.2% (ADM), 20.5% (VCR) and 13.1% (MTX). In addition, direct measurement of caspase-3 activity revealed that CDDP but not the other drugs activated caspase-3 in HOS cells. These analyses revealed that only CDDP induced apoptosis of HOS cells via activation of caspases. Furthermore, DMQD-CHO, VEID-CHO and IETD-CHO inhibited CDDP-induced apoptosis of HOS cells, suggesting that caspase-3, -6 and -8 are involved in the signaling pathway of CDDP-induced apoptosis. In contrast, none of the caspase inhibitors inhibited cell death induced by the other anticancer drugs. CONCLUSIONS: This study demonstrates that CDDP specifically induces apoptosis via activation of caspases and the other anticancer drugs induce death of HOS cells via different signaling pathways. It also demonstrates that caspase-8 is a key molecule in the earliest stage of the signaling pathway of CDDP-induced apoptosis of HOS cells, and caspase-3 works downstream of caspase-8.

Antineoplastic Agents↗
PubMed2000

Why are some patients with severe neglect able to copy a cube? The significance of verbal intelligence.

Cube-copying is often used to assess constructional ability of brain-damaged patients and the influence of unilateral spatial neglect is often pointed out in patients with right hemisphere lesions. However, some patients with severe neglect perform cube-copying satisfactorily. The aim of the present study is to identify the factors that affect the performance of cube-copying in patients with left unilateral spatial neglect. Constructional performance was investigated in 100 patients with unilateral spatial neglect using a task to copy the Necker cube. The relationship of the patients' cube-copying performance to the severity of their neglect, as well as other factors (verbal intelligence, age, duration after onset of the disease, educational level, lesion site, piecemeal approach, and side of starting to copy) was analyzed. Twenty-two normal subjects also participated in this study as controls. Among many factors adopted for analysis, neglect severity and verbal intelligence were found to be primary factors affecting the cube-copying performance of the patients with unilateral spatial neglect. The effect of neglect severity on cube-copying performance was apparent in the patients whose verbal intelligence was deteriorated, but was not observed in the patients with preserved verbal intelligence. Similarly, the effect of verbal intelligence on cube-copying performance was apparent in the patients with severe neglect, but not in the patients with mild neglect. We conclude that constructional ability in the copying of a cube is determined by verbal intelligence, as well as by the severity of unilateral spatial neglect.

Aged↗