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M Sakuma

Publications and source records attributed to M Sakuma.

At least 91 records · Page 5Linked to original sources

A prospective follow-up study of brain morphology and cognition in first-episode schizophrenic patients: preliminary findings.

Brain morphological abnormalities have been reported in several independent investigations of chronic schizophrenic patients. The present study is a prospective 4-year follow-up of first-episode schizophrenic patients to determine whether some of these abnormalities may be a consequence of regional brain structural change over time after the onset of a first psychotic episode. Whole hemisphere, temporal lobes, superior temporal gyrus, hippocampus, caudate, corpus callosum, and lateral ventricles were measured in a series of MRI scans taken over a 4-year period in 20 patients and five controls. Total volume reduction was noted in both hemispheres to a greater degree in patients than controls. When adjusted for total brain size, left ventricular enlargement occurred in patients, but not controls, over time. These preliminary data suggest that subtle cortical atrophy may be occurring over time after the onset of illness.

Adult↗

Chemical analysis of neurotransmitter candidates in clonal cell lines from Drosophila central nervous system, II: Neuropeptides and amino acids.

In a previous study, we have found acetylcholine and/or L-DOPA in 10 colonial clones from one cell line of Drosophila larval central nervous system (CNS). In this study, to characterize clonal neuronal phenotypes further, we have examined three neuropeptides and 19 amino acids using HPLC system. Substance P and proctolin were found in seven and eight out of ten clones, respectively. On the other hand, somatostatin was expressed in all ten clones. GABA and taurine were not detected in any clones. Glutamate, which is an excitatory transmitter in Drosophila, was found in all the clones, although its content was different seven times among them. Glycine, which is not known as a transmitter in Drosophila, was found to be unevenly expressed among them. Therefore, the conspicuous expression of peptides or amino acids in some clones suggests that the substances have a special role in Drosophila CNS.

Amino Acids↗

Alterations in coagulation and fibrinolysis after surgery for aortic aneurysm.

We investigated the alterations in the coagulation and fibrinolysis systems after aortic aneurysm surgery under cardiopulmonary bypass (CPB) while using newly developed "molecular markers". Fibrinogen and antithrombin III (AT-III) decreased after surgery but returned to normal values within three days. The thrombin-antithrombin III complex (TAT) and plasmin-alpha-2-plasmin inhibitor complex (PIC) both showed increased values even preoperatively, which indicated that coagulation and fibrinolysis were activated in some patients with an aortic aneurysm. Both markers maintained a high level for at least 14 days after surgery. The fibrin degradation product (FDP) also showed an increased value before and after surgery. These results apparently showed that coagulation/fibrinolysis had already been activated in some patients and maintained such a state for at least 14 days after surgery. The relation of activated system and postoperative organ dysfunction as well as the means to suppress such activation are also discussed.

Aged↗

Preoperative disseminated intravascular coagulation (DIC) associated with aortic aneurysm--does it need to be corrected before surgery?

Disseminated intravascular coagulation (DIC) is one of the complications accompanying aortic aneurysm. We herein report four patients with aortic aneurysm who had DIC preoperatively. In all four cases, DIC was corrected immediately after surgery; however, in two cases, DIC could not be corrected preoperatively. This prompted us to reconsider the importance of correcting DIC before surgery. Of the four cases reported in this paper, DIC existed even at the time of surgery in two cases, in spite of meticulous treatment with heparin and/or protease inhibitor; however, the DIC could be removed postoperatively even in these two cases. Surgeons should not waste time with intensive DIC treatment preoperatively. If the DIC cannot be corrected within more than 2 weeks of meticulous treatment, surgeons should then perform surgery on the patient. In addition, it is also essential to ensure that the DIC is due to the aneurysm itself and that no other disease processes have been overlooked.

Aged↗

The incidence of internal malignancies in pemphigus and bullous pemphigoid in Japan.

To evaluate the significance of the association of malignancy with autoimmune blistering diseases, we studied the incidence of internal malignancies in pemphigus and bullous pemphigoid based upon 496 cases of pemphigus and 1113 cases of bullous pemphigoid in Japan. Results showed that (1) an association between internal malignancies and pemphigus was observed in 25 out of 496 cases (5.0%), while that with bullous pemphigoid was seen in 64 out of 1113 cases (5.8%). Such association ratios were significantly higher than that of the controls aged over 70 years old (0.61%); (2) The average ages of pemphigus/bullous pemphigoid with malignancy were 64.7 and 69.2 years, respectively. The association ratio of malignancy with pemphigus increased by age, while that with pemphigoid was not correlated with aging; (3) Lung cancer was most common in pemphigus and gastric cancer in bullous pemphigoid; (4) There were no significant differences in the titers of circulating antibody, the presence or extent of mucous involvement or annular erythema between bullous pemphigoid patients with malignancy and without malignancy. Our results indicated that detailed examination for internal malignancy is essential for those patients with pemphigus or bullous pemphigoid.

Aged↗

Analysis of proximal fragment sclerosis and surgical outcome of scaphoid non-union by magnetic resonance imaging.

32 patients with scaphoid non-union were examined to clarify the relationship between pre-operative radiographic sclerosis in the proximal fragment and signal intensity on magnetic resonance imaging (MRI). In addition, the correlation between changes in signal intensity in the proximal fragment and surgical outcome after bone grafting and internal fixation was investigated. Proximal fragment sclerosis was observed in seven patients. Comparison of the T1 and T2-weighted images with those of the 25 patients without proximal fragment sclerosis revealed no differences. Therefore, there was no relationship between sclerotic changes on plain radiography and the degree of avascularity of the proximal fragment assessed by MRI. None of the patients who had low signal intensity on both T1 and T2-weighted images achieved union within 5 months after surgery. Thus the detection of signal intensity on both T1 and T2-weighted images can be useful to predict the prognosis after the surgery.

Adolescent↗

Spinal cord protection during thoracoabdominal aortic aneurysm repair: results of selective reconstruction of the critical segmental arteries guided by evoked spinal cord potential monitoring.

PURPOSE: The purpose of this study is to evaluate the results of spinal cord protection based on selective reconstruction of the segmental arteries. METHODS: Twenty-one patients who underwent repair of aneurysms (nine descending thoracic and 12 thoracoabdominal: three type I, six type II, and three type III) were analyzed. Ten patients had postdissection aneurysms. Operative techniques consisted of evoked spinal cord potential (ESP-dsc) monitoring and femorofemoral bypass in all cases, segmental resection in 12, and mild systemic hypothermia in eight. Arteries critical for cord blood flow were selectively reconstructed; if ESP-dsc showed change after resection of an aortic segment, arteries originating from this segment were reconstructed. RESULTS: ESP-dsc change was observed in 12 patients. Arteries found to be critical were at the T8-L1 level in all but three cases. Selective reconstruction was performed in 10 of these 12 patients. ESP-dsc change could be reversed before reconstruction in four cases, three by control of back-bleeding critical arteries. Selective reconstruction resulted in return of ESP-dsc in seven other patients. Spinal cord injury occurred in five patients, two of whom did not undergo selective reconstruction. CONCLUSION: These results suggest that our current technique allows determination of critical arteries but does not completely prevent injury.

Adult↗

Significance of the right ventricular free wall in dogs with and without pulmonary constriction.

To evaluate the role of the right ventricular (RV) free wall in cardiac function, RV and left ventricular (LV) wall segment lengths were measured by ultrasonic crystals in 10 open chest dogs with the pericardium preserved. Right coronary artery (RCA) was perfused separately by own blood and the flow was reduced stepwise until active shortening (delta L) of the RV segment disappeared or RCA flow became zero (Ischemia). The experiment was repeated with and without pulmonary stenosis (PS). At Ischemia, RV and LV systolic pressures decreased. RV end-diastolic length increased and RV delta L decreased. LV end-diastolic length and LV delta L were reduced. LV stroke volume concurrently fell. These changes became more prominent with PS. The critical level of RCA flow, at which RV delta L began to change, was higher with PS (5.27 +/- 2.85 ml/min, mean +/- S.D.) than without PS (1.44 +/- 1.16, p < 0.01). Based on the relationships between RV delta L and percent changes in RV developed pressure and stroke volume, the degree of the decreases in RV developed pressure and stroke volume at RV delta L of zero were estimated to be about 20%. These results indicate that the RV free wall partly contributes to maintaining the RV function, especially during RV pressure overload.

Animals↗

Specific binding of dehydroepiandrosterone sulfate to rat liver cytosol: a possible association with peroxisomal enzyme induction.

Incubation of [3H]dehydroepiandrosterone sulfate (DHEAS) with rat liver cytosol demonstrated its specific binding with a dissociation constant of 72 +/- 14 nM and a maximal binding capacity of 312 +/- 105 fmol/mg cytosol protein. The binding correlated with the amount of cytosol protein, and depended on time, temperature and pH, with equilibrium being reached after 6 h at 0 degrees C and pH 7.5. Boiling or treatment of the cytosol with proteases or sulfhydryl-blocking reagents affected the binding. The apparent molecular mass of the binding entity was estimated to be 160-230 kDa by HPLC gel filtration. In competitive binding studies, free steroids, including dehydroepiandrosterone (DHEA), sulfatase substrates and ligands of organic anion binders such as ligandin and fatty acid binding protein, had no effect on the [3H]DHEAS binding. Peroxisome proliferators also had no effect, except Wy-14,643. Competition with various steroids related to DHEAS revealed strict structural requirements for DHEAS binding, in which epiandrosterone sulfate was almost as effective as unlabeled DHEAS in inhibiting [3H]DHEAS binding. These findings indicated the presence of a binding protein highly specific to DHEAS in rat liver cytosol. The DHEAS binding in liver cytosol was 2-fold higher in male than in female rats. The cytosolic DHEAS binding was highest in the liver, followed by the kidney and heart. The possibility of association between the DHEAS binding and DHEA induction of peroxisomal beta-oxidation is discussed.

Animals↗

Prolonged alkylcatechol-induced expression of c-jun proto-oncogene followed by elevation of NGF mRNA in cultured astroglial cells.

We have already shown that alkylcatechol markedly enhances synthesis/secretion of nerve growth factor (NGF) in cultured mouse fibroblasts and astroglial cells through immediate accumulation of NGF mRNA and that the stimulatory effect of alkylcatechol on NGF synthesis/secretion is synergistically enhanced by the coadministration of phorbol 12-myristate 13-acetate (PMA). The stimulatory effect on NGF mRNA expression of astroglial cells in culture by 4-methylcatechol (MC), an alkylcatechol, and/or PMA was blocked by treatment of the cells with cycloheximide, suggesting de novo synthesis of some cellular protein(s) is essential for the observed increase in the NGF mRNA level. The exposure to MC and/or PMA caused a rapid increase in c-fos mRNA content, which was immediately followed by an increase in c-jun mRNA, prior to NGF mRNA elevation. The expression of c-fos mRNA was transiently enhanced in all cases of the treatment with MC and/or PMA. The c-jun mRNA expression was also observed transiently when the cells were treated with PMA alone, while the expression of c-jun mRNA was pronounced and long-lasting after the treatment with MC, which was much further enhanced by the coadministration of PMA. The result that the profile of the change in c-jun mRNA expression resembled that in NGF mRNA expression suggests that the increase in c-jun mRNA is responsible for the subsequent increase in NGF mRNA after MC treatment. The contransfection of mouse astroglial cells with expression plasmids of c-fos and/or c-jun and NGF promoter gene showed that simultaneous expression of both c-fos and c-jun genes was necessary to enhance NGF promoter activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Chemical analysis of neurotransmitter candidates in clonal cell lines from Drosophila central nervous system. I. ACh and L-dopa.

To characterize neuronal phenotypes, aminergic neurotransmitters, i.e. acetylcholine (ACh), catecholamine (CA)s and other biogenic amines (serotonin, octopamine), were surveyed in 10 colonial clones from one cell line of Drosophila larval CNS using HPLC-ECD system. ACh, which is a neurotransmitter in Drosophila, was found in 7 out of 10 clones. CAs, their metabolites, and other amines were not detected in any clones. However, all the 10 clones expressed L-dopa, a precursor of CAs. Consequently, seven clones expressed ACh and L-dopa. L-dopa as a novel neurotransmitter candidate was discussed.

Acetylcholine↗

Purification and properties of long-chain acyl-CoA hydrolases from the liver cytosol of rats treated with peroxisome proliferator.

Two long-chain acyl-CoA hydrolases, referred to as ACH1 and ACH2, were purified from the liver cytosol of rats fed a diet containing di(2-ethylhexyl)phthalate, a peroxisome proliferator. The molecular mass of ACH1 was estimated to be 73 kDa by gel filtration, and that of the subunits, 36 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The corresponding values of ACH2 were 42 and 43 kDa, respectively. Both enzymes were active toward fatty acyl-CoAs with chain-lengths of C12-16, but ACH1 had relatively broad specificity as acyl-CoAs with C8-18 were good substrates. A marked difference in their catalytic properties was found in the maximal velocity; for palmitoyl-CoA, 553 and 4.23 mumol/min/mg with Km values of 5.9 and 5.4 microM for ACH1 and ACH2, respectively. ACH2 underwent severe substrate inhibition with high concentrations of long-chain acyl-CoAs, whereas ACH1 did not. Examination with various reagents including divalent cations, sulfhydryl-blocking reagent, nucleotides, and hypolipidemic drugs, characterized ACH1 and ACH2 with several properties distinct from those of mitochondrial and microsomal hydrolases. ACH1 and ACH2 were also discernible in that the former, but not the latter, was inhibited by ATP. In the liver cytosol of rats treated with di(2-ethylhexyl)phthalate, about 90% of palmitoyl-CoA hydrolase activity was titrated with anti-ACH1 and anti-ACH2 antibodies. Immunoblot analysis suggested the presence of the enzymes also in extrahepatic tissues, especially in the brain and testis (ACH1), and in the heart and kidney (ACH2).

Animals↗

Newly established cell lines from Drosophila larval CNS express neural specific characteristics.

From the central nervous system of Drosophila melanogaster 3rd instar larvae, eight continuous cell lines have been established (named ML-DmBG1 to 8). Using ML-DmBG2, single colony isolation was carried out and six colonial clones were obtained. All reacted to the antibody to horseradish peroxidase, which is a neuronal marker in insects. Acetylcholine, a known neurotransmitter in Drosophila, was detected in three of the colonial clones by high performance liquid chromatography. Therefore, it is concluded that the established colonial clones are neural cells originating in the larval central nervous system. Among them, some variation was observed with respect to morphology, acetylcholine content, and reactivity to anti-HRP. The variation may reflect the heterogeneity of cells composing the central nervous system.

Acetylcholine↗

The incidence of internal malignancies in autoimmune blistering diseases: pemphigus and bullous pemphigoid in Japan.

To evaluate the significance of the association of malignancy with autoimmune blistering diseases, we studied the incidence of internal malignancies in 496 pemphigus and 1,113 bullous pemphigoid (BP) patients in Japan. Statistical analysis showed that an association ratio of internal malignancies with pemphigus was 5.0% and that with BP was 5.8%. These ratios were significantly higher than that of the controls aged over 70 years (0.61%). Our results indicate that detailed examination for internal malignancy is essential for patients with pemphigus or BP.

Age Factors↗

[Clinical results of selective cerebral perfusion during reconstruction of the transverse aortic arch].

Selective cerebral perfusion (SPC) has become a reliable method for brain protection during reconstruction of the transverse aortic arch. However, arterial cannulation technique for the branches of the aortic arch varies among groups, and the necessity of perfusion for the left subclavian artery is controversial. To avoid atheroembolism to the brain and malperfusion of the vertebral arterial system, we carefully selected the arterial cannulation technique according to the result of preoperative ultrasonographic and angiographic evaluation of the branches of the aortic arch, and decided the necessity of perfusion for the left subclavian artery according to the dominance of the two vertebral arteries and the result of pressure monitoring of all three branches. In this report, we analyzed our clinical results of selective cerebral perfusion on 22 consecutive patients, which was performed between April 1992 and December 1993. There were 14 atherosclerotic aneurysms and 8 aortic dissections. The flow rate for SCP was controlled by a single blood pump separate from that for systemic perfusion, with the mean value being 13.1 ml/kg/min. Mean of minimum left superficial temporal arterial pressure was 51 mmHg, mean duration of SCP was 134 minutes, and mean of the lowest esophageal temperature was 17.9 degrees C. Blood pH was regulated with alpha-stat strategy. Arterial cannula for SCP was inserted directly into the vessels through a stab wound in most cases. In three of four patients in whom dissection extended to the branches, a balloon catheter was introduced through the lumen of the aortic arch.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗