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Biomedical subjects

N Nakajima

Publications and source records attributed to N Nakajima.

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

Functional glucosylation of kojic acid and daidzein with the Eucalyptus membrane-associated UDP-glucosyltransferase reaction system.

Kojic acid was glucosylated to kojic acid 5- and 7-O-beta-D-glucopyranosides by cultured cells of Eucalyptus perriniana. The glucosylation was also performed effectively by the enzymatic reaction system using membrane-associated UDP-glucosyltransferase from the cells with addition of UDP-glucose. The production of the 5-O-D-glucoside occurred exclusively prior to that of the 7-O-glucoside in both systems. In the same manner, daidzein was converted to daidzin (daidzein 7-O-beta-D-glucopyranoside) by the enzymatic system. Here, we propose methods for the structural modification of phytoestrogen-related substances by enzymatic beta-glucosylation.

Journal Article↗
PubMed2001

Molecular cloning, sequencing, and expression of cDNA encoding serine protease with fibrinolytic activity from earthworm.

An earthworm, Lumbricus rubellus, produces alkaline trypsin-like proteases that are greater than trypsins in their stability and strong tolerance to organic solvents. cDNAs encoding strong fibrinolytic proteases (F-III-2 and F-III-1) in the six isozymes were cloned and sequenced to study their stability-structure relationship. The cDNAs of F-III-2 and F-III-1 comprised 1011 and 973 bp and included open reading frames that encode polypeptides of 245 and 246 amino acid residues, respectively. The deduced amino acid sequences of F-III-2 and F-III-1 have 7 and 8 activation peptides in the N-termini respectively, indicating that they are translated as proenzymes and modified to active forms by posttranslational processing. They showed similarity to mammalian serine proteases and conserved the catalytic amino acid residues, however, neither arginine nor lysine residues were present in the autolysis region. The gene encoding the native form of F-III-2 was expressed in Pichia pastoris to produce and secrete the earthworm protease in the culture medium, which dissolves an artificial fibrin plate.

Amino Acid Sequence↗
PubMed2001

Cerebellar hemorrhage caused by dural arteriovenous fistula: a review of five cases.

OBJECT: In this study the authors performed a retrospective analysis of five cases in which the patients (three women and two men) were treated for intracranial dural arteriovenous fistulas (AVFs) associated with cerebellar hemorrhage. On the basis of their findings, the authors evaluated the characteristics of this unusual symptom. METHODS: The dural AVFs were located in the right cavernous sinus in one patient, the left transverse-sigmoid sinus in three patients, and the right superior petrosal sinus (SPS) in one patient. All patients presented with severe headache and/or loss of consciousness. Computerized tomography scans revealed a small cerebellar hemorrhage near the fourth ventricle and hydrocephalus in four cases, and a massive hemispheric cerebellar hemorrhage in the remaining case. The four patients with small hemorrhages underwent ventriculostomy and endovascular treatment; all recovered. The patient suffering from a massive hemorrhage because of a dural AVF in the SPS was treated by suboccipital craniectomy, hematoma evacuation, and removal of the vascular anomaly. This patient remains in a persistent vegetative state. In four cases, results of angiography demonstrated retrograde leptomeningeal venous drainage through the SPS to the anastomotic lateral mesencephalic vein (ALMV) and/or to the vein of the lateral recess of the fourth ventricle (VLR4V). Retrograde leptomeningeal venous drainage to the ALMV and/or VLR4V was responsible for cerebellar hemorrhage in these cases. CONCLUSIONS: Thus, it is important to consider dural AVF in cases in which there is even a small hemorrhage near the fourth ventricle accompanied by intraventricular perforation and a decreased level of consciousness.

Aged↗
PubMed2001

[Usefulness of ambulatory adjuvant chemotherapy with low-dose epirubicin in patients with axially-node positive breast cancer: Chiba Epirubicin Cooperative Study Group].

We evaluated the usefulness of adjuvant chemotherapy with low-dose epirubicin (EPI) as a key drug in patients with axially-node positive breast cancer. All the 24 patients who were entered in the study between January 1991 and December 1992 were shown histologically to have more than 4 axially-node involvement and underwent curable resection for the breast lesions. Twenty mg/m2 of EPI was administered intravenously every 4 weeks as ambulatory treatment for 1 year and 5-fluorouracil (5-FU) and tamoxifen (TAM) were concomitantly administered at a dose of 150 mg/day and 20-40 mg/day, respectively, daily for 2 years. The median follow-up period was 70 months with a 55.1% 5-year relapse-free survival and 67.4% 5-year survival rate. One patient developed Grade 3 nausea.vomiting, anorexia and general fatigue; however, the other toxicities were mild, such as Grade 1 leukopenia, liver dysfunction, nausea.vomiting, anorexia and general fatigue. This adjuvant therapy with low-dose EPI was safely administered to outpatients, and is considered to be useful for the treatment of axially-node positive breast cancer.

Adult↗
PubMed2001

[A case report on two stage operation of dissecting aneurysm of DeBakey IIIb type associated with dense pulmonary adhesion].

Successful surgical treatment of chronic dissecting aneurysm (DeBakey IIIb type) in a 50-year-old man was reported. His left lung was tightly adhered to the aneurysm and the chest wall, because he had a previous operation history for pyothorax. This patient showed copious pulmonary bleeding by the pulmonary injury during adhesiotomy. We selected the two stage operation for deducting operation risks, and finished the first operation at the end of adhesiotomy. Some pieces of e-PTFE sheet had been put between lung and thoracic wall, or aneurysm. After a week, waiting the cure of this pulmonary injury, the second operation was performed with a small quantity of pulmonary bleeding. There wasn't fresh pulmonary adhesion because of protection by e-PTFE sheet. The two stage operation was useful in cases associated with dense pulmonary adhesion.

Aortic Dissection↗
PubMed2001

Pulsatile cardiopulmonary bypass failed to prevent neuropsychological dysfunction.

To prevent neurological complications during cardiopulmonary bypass, cerebrovascular screenings by magnetic resonance angiography and computed tomographic scan of the brain were performed preoperatively in patients who had ischemic heart disease and all patients aged 60 years or older. From 1996 to 1999, 173 adult patients (mean age 65.1+/-7.7 y) were evaluated. Forty-one patients were considered to be at high risk from the screening tests and pulsatile cardiopulmonary bypass was applied. The remaining 132 patients were placed in the control group. Postoperative cerebral infarction caused by embolism was encountered in three patients (3/173, 1.7%), two in the high-risk group (2/41, 4.8%) and one in the control group (1/132, 0.8%), but the difference between these incidences was not statistically significant. Cerebral infarctions caused by brain hypoperfusion did not occur in this series. A neuropsychological test (Hasegawa's dementia scale, HDS) was done pre- and postoperatively. No one was diagnosed with dementia preoperatively, whereas 7 patients were diagnosed with dementia postoperatively. Among these 7 patients, 6 patients were in the high-risk group (17.1%, 6/35) and one patient was in the control group (0.9%, 1/113). Under these circumstances, using cerebrovascular screening and pulsatile cardiopulmonary bypass, cerebral infarction due to hypoperfusion did not occur, but cerebral infarction due to embolism was encountered, and neuropsychological dysfunction was not prevented.

Aged↗
PubMed2001

[Investigation of verdicts of civil suits brought against hospitals involving crimes committed by mental hospital inpatients with psychotic disorders].

The author investigated 11 verdicts of Japanese civil suits brought against hospitals involving crimes committed by mental hospital inpatients with psychotic disorders, principally by victims of injuries or by surviving relatives of homicide victims. About the half of the verdicts are based on the same logic. First, a detailed, case-specific investigation was performed. In some cases it was proven that the accidents could not have been predicted, and the suits were dismissed. In others the plaintiffs won the suits, because it was found that the violent acts were predictable and that the hospital staff had the means to prevent them. These verdicts require the hospital staff to predict the patient's actions according to the psychiatric history and present condition and then to make an appropriate response. This process is similar to the clinical decision-making process, although there have been some dubious findings in some of the court cases. However, the author also found that some verdicts were inappropriate and insufficient in that there was no individual investigation of the offender. Examining all 11 verdicts, the author found that the type of admission procedure adopted for the offender, whether they had a past history of violence, and whether the hospital was public or private did not seem to be significant to the judges in making their decisions.

Adult↗
PubMed2001

A study on the role of platelet function in patients with chronic pulmonary thromboembolism.

UNLABELLED: There has been no study on the platelet function in the patient with chronic pulmonary thromboembolism (CPTE). We speculate that the platelet function may be elevated in the patients. PURPOSE: 1. The platelet functions were compared among CPTE before surgery, deep vein thrombosis (DVT) and normal adult people. 2. The severity of CPTE in clinical grading to the platelet functions were compared. 3. The platelet function were compared before and after pulmonary thromboendarterectomy. METHODS: Pre-opetative CPTE group (n=16), post-operative CPTE group (n=11), DVT group (n=9) and control group (normal adult people: n=33) were investigated on the platelet functions defined as platelet adhesion (AD) and platelet aggregation (AG) test in this study. RESULTS: 1. No activation of platelet functions was observed in pre-operative CPTE patients. 2. There was no apparent relationship between the severity of disease and platelet functions. 3. Significant elevation of AG was obtained in the patients who received pulmonary thromboendarterectomy. CONCLUSION: In consideration to the finding in postoperative study, the administration of anti-platelet drug will help to prevent re-thrombosis of the pulmonary arteries after surgery.

Adolescent↗
PubMed2001

[Basic techniques in vascular surgery].

The procedure for vascular resection and reconstruction includes exposure of the diseased vessel, temporary interruption of blood flow, resection of the diseased segment, vascular repair or anastomosis and restoration of blood flow. Adequate exposure, including the healthy portions on both the afferent and efferent sides of the diseased segment, facilitates subsequent steps in the procedure. Since the temporary interruption of blood flow could lead to ischemic and reperfusion injuries, it is necessary to take measures to protect organs that receive blood flow from diseased vessels. The basic principles in vascular suturing are single sutures through all layers and intima-to-intima approximation. Continuous simple sutures are often used for vascular repair and anastomoses. In the case of anastomoses between small arteries, however, interrupted simple sutures are preferred to prevent stenosis. Twisting, stenosis, and overstretch at the point of anastomosis are errors that result in failure of vascular reconstruction. The methods for overcoming size differences between anastomosed vessels should be understood. Topical heparinization is easy and a useful method to prevent the production of thrombus. Systemic administration of anticoagulants is not always needed.

Anastomosis, Surgical↗
PubMed2001

Our experience of surgical treatment for chronic pulmonary thromboembolism.

Chronic pulmonary thromboembolism is one of the causes of pulmonary hypertension and carries a poor prognosis. Medical therapy is generally unsatisfactory, and surgery provides the only possibility of a cure. Though over 1400 cases have undergone pulmonary thromboendarterectomy (PTE) worldwide, the surgical procedure is performed with success only at a few institutions. It is important to select suitable patients, to perform PTE (not an embolectomy) and to manage successfully postoperatively. We report our experiences of surgical treatment for chronic pulmonary thromboembolism. Between June 1986 and March 2001, 50 patients (15 men, 35 women) underwent PTE at our hospital. The mean age was 51.3 years (range 22-73). We have adopted two surgical approaches to PTE. The number of operation deaths was 9 (18.0%). Forty-one patients survived, and the declines in their mean pulmonary arterial pressures (m-PAP) and pulmonary vascular resistance (PVR), and the inceraeses in cardiac indices (C.I.), were significant postoperatively. Their PaO2 improved significantly after 6 months. The symptoms were markedly reduced, and survival after PTE was 86-88% at 10 years. The only therapeutic alternative to PTE is lung transplantation. The great advantage of PTE includes an excellent long-term results without the risks associated with chronic immunosuppression and potential for chronic allograft rejection. We conclude that PTE can improve the prognosis of selected patients with chronic pulmonary thromboembolism, and morphological classification by CT scan could be useful for predictions about the surgical accessibility.

Adult↗
PubMed2000

Zinc release from the CH2C6 zinc finger domain of FILAMENTOUS FLOWER protein from Arabidopsis thaliana induces self-assembly.

The FILAMENTOUS FLOWER gene from Arabidopsis thaliana is a member of a gene family whose role is to specify abaxial cell fate in lateral organs. Analysis of the amino-terminal region of the FILAMENTOUS FLOWER protein suggests that seven cysteine residues at positions 14, 26, 30, 33, 54, 56, and 57, and two histidine residues at positions 18 and 24 contribute to a putative zinc finger motif, Cys-X(3)-His-X(5)-His-X-Cys-X(3)-Cys-X(2)-Cys-X(20)-Cys-X-Cys-Cys. Zinc determination experiments revealed that the FILAMENTOUS FLOWER protein binds two zinc ions per molecule. Chemical modification was required to release one zinc ion, whereas the other was released spontaneously or more rapidly in the presence of metallochromic indicator. The loss of a zinc ion and the subsequent structural change of the zinc finger domain were correlated with the multimerization of the FILAMENTOUS FLOWER protein. A cysteine residue at position 56 in the FILAMENTOUS FLOWER protein potentially interferes with zinc ligation within the zinc finger and causes this zinc release. In support of this, substitution of the Cys(56) by alanine suppressed both the zinc release and the multimerization of the FILAMENTOUS FLOWER protein. Deletion analysis showed that the region between positions 45 and 107 functions in the intermolecular contacts between FILAMENTOUS FLOWER proteins. This region corresponds to the carboxyl-terminal half of the zinc finger domain and the following hydrophobic region containing two putative alpha-helices. Our results suggest that the FILAMENTOUS FLOWER protein forms a range of different conformers. This attribute may lead to a greater degree of functional flexibility that is central to its role as an abaxial cell fate regulator.

Alanine↗
PubMed2000

Allelic loss in human intrahepatic cholangiocarcinoma: correlation between chromosome 8p22 and tumor progression.

Intrahepatic cholangiocarcinoma (ICC) is the second most common malignant primary tumor of the liver in Japan. Despite progress in operative techniques and adjuvant therapy, the prognosis of ICC remains very poor. Therefore, it is important to investigate the mechanism of carcinogenesis and progression of ICC. We screened allelic losses at 6 loci, including that of novel tumor-suppressor gene FEZ1 on chromosome 8p, and at 5 microsatellite loci to define the association with tumor-suppressor genes (HNPCC, APC, RB1, p53, DCC) in tumors from 18 unrelated ICC patients by PCR-loss of heterozygosity (LOH) assay and correlated the alterations with clinicopathological parameters. As a result, 61.1% (11 of 18) of patients showed LOH at 1 of the loci at least, and microsatellite instability was observed in 16.7% (3 of 18). At locus D8S258, relatively frequent LOH was detected (17.6%) compared with other loci on chromosome 8p. Among the other 5 chromosomal arms tested, the highest frequency of LOH (23.5%) was observed at D17S153. Fifty percent of cases with the mass-forming + periductal infiltrating type were frequently detected by LOH at D8S258 compared to cases of the mass-forming or intraductal growth type. In conclusion, we show that 1 putative tumor-suppressor gene on 8p22 may relate to progression of ICC and suggest that the p53 tumor-suppressor gene may be associated with carcinogenesis of ICC.

Aged↗
PubMed2000

Search for UV-responsive genes in human cells by differential mRNA display: involvement of human ras-related GTP-binding protein, Rheb, in UV susceptibility.

The search for genes responsible for the sensitivity of human cells to cell-killing effects of UV is an important area of biological research. To identify candidate genes responsible for UV sensitization, levels of mRNA expression were compared between UV-sensitive RSa cells and UV-resistant variant UV(r)-1 cells, using a differential display method and Northern blot analysis. Messenger RNA expression levels of human Ras homologue enriched in brain (Rheb) and/or a Rheb-like gene were up-regulated and slightly decreased in UV-irradiated RSa and UV(r)-1 cells, compared to in mock-irradiated cells, respectively. RSa and UV(r)-1 cells, both of which were treated with antisense oligonucleotides for Rheb RNA, exhibited an increased resistance to UV cell-killing. It remains unclear why UV(r)-1 cells are resistant to UV yet express Rheb mRNA at high levels. However, the results of antisense experiments together with the up-regulation in UV-irradiated RSa cells, suggest that Rheb is involved in the UV sensitization of both cells to UV cell-killing.

Cell Death↗