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M Seki

Publications and source records attributed to M Seki.

571 records · Page 32Linked to original sources
PubMedDate not supplied

Mathematical model for analysis of mass transfer for immobilized cells in lactic acid fermentation.

A new mathematical model is proposed to analyze the mass transfer behavior in lactic acid fermentation using immobilized cells entrapped in calcium alginate. The model is comprised of material balance equations for glucose, free lactic acid, and several ions. The dissociation rate of lactic acid (rdiss) is involved in the proposed equations. To solve the equations numerically, a modified calculating method is proposed. Through model analysis, the possible mass transfer behavior in the gel bead was discussed. The model is validated by comparisons with the experimental results obtained from batch and continuous fermentation. The simulations using the model were made to investigate the mass transfer limitation in the gel beads. The results showed that the cell density gradient was formed in the gel beads and it was caused by the accumulation of the inhibitory product (free lactic acid), not by substrate starvation. Moreover, unusual mass transfer behavior of lactate ion in the immobilization support was pointed out.

Biotechnology↗
PubMedDate not supplied

Microfabricated polymer chip for capillary gel electrophoresis.

A polymer (PDMS: poly(dimethylsiloxane)) microchip for capillary gel electrophoresis that can separate different sizes of DNA molecules in a small experimental scale is presented. This microchip can be easily produced by a simple PDMS molding method against a microfabricated master without the use of elaborate bonding processes. This PDMS microchip could be used as a single use device unlike conventional microchips made of glass, quartz or silicon. The capillary channel on the chip was partially filled with agarose gel that can enhance separation resolution of different sizes of DNA molecules and can shorten the channel length required for the separation of the sample compared to capillary electrophoresis in free-flow or polymer solution format. We discuss the optimal conditions for the gel preparation that could be used in the microchannel. DNA molecules were successfully driven by an electric field and separated to form bands in the range of 100 bp to 1 kbp in a 2.0% agarose-filled microchannel with 8 mm of effective separation length.

Coated Materials, Biocompatible↗
PubMedDate not supplied

Functional Independence Measure for Children (WeeFIM): a preliminary study in nondisabled Japanese children.

The Functional Independence Measure for Children (WeeFIM) was developed based on the FIMSM instrument to assess disability in children aged six months to seven years. Its reliability and validity have been studied, and normative data are available for American children. The WeeFIM instrument is potentially an internationally useful instrument, but data from other countries are lacking. The objectives of this study are to examine whether the WeeFIM instrument is applicable to Japanese children and to describe preliminary normative data. To study interrater reliability, we had two examiners assess 20 nondisabled children and calculated weighted kappas for individual item scores and intraclass correlation coefficients for total scores and motor and cognitive subscores. We then assessed 110 nondisabled children ages six months to seven years to obtain normative data and compared them with the American data. In 51 of these healthy children, we compared total WeeFIM scores with developmental ages as obtained with the Tsumori test, a standardized developmental test widely used in Japan to assess its concurrent validity. The weighted kappas were greater than 0.8, and the intraclass correlation coefficients were greater than 0.98. Total scores and motor and cognitive subscores increased with age, reaching a plateau at 60 to 72 months, which is similar to the American data. There were three patterns of chronologic changes in individual item scores: items showing high correlations with age (Spearman's rho > 0.8; grooming, dressing, memory, etc.), moderate correlations (0.8 > rho > 0.7; eating, bladder, comprehension, etc.), and lower correlations (0.7 > rho > 0.6; locomotion and chair transfer). Total scores correlated significantly with developmental ages (Spearman's rho = 0.938), but there was a discrepancy between each item score and the pass-or-fail patterns of the Tsumori test. This study demonstrated the applicability of the WeeFIM instrument to Japanese children with satisfactory reliability and validity and provided preliminary normative data for future studies.

Activities of Daily Living↗
PubMedDate not supplied

Tumor thrombus in the branches of the distal portal vein: CT demonstration.

Punctate and linear low density structures adjacent to the tumor nodules in the CT images of eight patients with hepatocellular carcinomas were followed for greater than 5 months to investigate the evolution of these low density structures. During the period of follow-up, patients were given anticancer therapy. Computed tomographic, angiographic, and autopsy examinations indicated that the CT finding of punctate or linear low density structures represented a tumor thrombus in the portal branches of the third and more distal orders. In two cases that showed punctate or linear low density structures adjacent to the distal side of the tumor nodules to the porta hepatis, a daughter nodule was detected by CT at 6.5 and 9.2 months, respectively, after the appearance of the low density structures. In two cases that showed punctate or linear low density structures adjacent to the proximal side of the tumor nodules to the porta hepatis, rapid and extensive tumor growth was found by CT at 5.4 and 8.0 months, respectively, after the appearance of the low density structures.

Aged↗
PubMedDate not supplied

Liver hypertrophy and portal hypertension in association with tumor thrombus in the portal vein: CT findings.

The growth rate of tumor thrombus in the portal vein and the concomitant enlargement of the volumes of the left lateral segment of the liver and the spleen were retrospectively investigated in 11 patients with hepatocellular carcinoma (HCC). In 7 of the 11 patients the left lateral segment of the liver enlarged as the tumor thrombus extended to the right second order branches and the more proximal order branches to the porta hepatis and eventually obstructed these branches. The volume of the left lateral segment was 1.3 to 2.7 times larger, compared with its original volume at the time of HCC detection. An increase in splenic volume was also found in 8 of the 11 patients. The increasing ratios of the splenic volume amounted to 1.3 to 2.1 times the volume found at the time of HCC detection. The growth of tumor thrombus in the right first order branch and portal trunk and the ensuing obstruction of these branches by the tumor thrombus resulted in the development of intractable ascites in 5 of the 11 patients and the development of hepatofugal collateral vessels in all 11 patients. These findings were not demonstrated prior to obstruction of these branches.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Age-related changes in nerve growth factor receptor immunoreactive neurons in the magnocellular basal forebrain system in rat brain--an immunocytochemical and morphometric study.

Morphometrical changes with aging in nerve growth factor receptor (NGFR) immunoreactive neurons in the basal forebrain were studied in juvenile and aged rat brains by means of NGFR immunohistochemistry. The nucleus basalis of Meynert (NBM) had cell loss and atrophy of NGFR immunoreactive neurons, and the horizontal nucleus of diagonal band of Broca (HNDB) showed only atrophy of these neurons. The medial septal nucleus and vertical nucleus of diagonal band of Broca had no significant change. Neuropil NGFR immunostaining was reduced in its intensity in the aged rats. As nerve growth factor is synthesized in the target areas and retrogradely transported to the nerve cell body within the basal forebrain and NGFR immunoreactive neurons are largely cholinergic ones, degeneration of NGFR-positive neurons in the basal forebrain may be related to a decreased cholinergic activity. The degeneration of the dendrites of NGFR-immunoreactive neurons were reported to be extensively found in the basal forebrain nuclei, in contrast, degeneration of the cell body of NGFR-immunoreactive neurons was confined to those in the NBM and HNDB in the present study. These findings suggest that atrophic changes in the dendrites precede those in the cell bodies of NGFR-immunoreactive neurons.

Aging↗
PubMedDate not supplied

Pulmonary arteriovenous malformation: radionuclide detection and quantification of right-to-left shunting.

Radionuclide detection and quantification of right-to-left shunting in two patients with pulmonary arteriovenous malformation and Rendu-Osler-Weber disease are described. Radionuclide studies are simple, atraumatic, and clinically useful in determining the vascular nature of the lesion and in quantifying the amount of right-to-left shunting with reasonable accuracy both before and after operation.

Adult↗
PubMedDate not supplied

[Frequency of lipoprotein-X (LP-X) in icteric patients. Comparison with some bioquimical data (author's transl)].

The authors have studied the frequency of an abnormal lipoprotein (LP-X), by the method presented by YAE e col. (21). The LP-X test is useful in differentiating of a cholestatic process from a non-cholestatic one, but it is not adequate to distinguish an intrahepatic cholestasis from an extrahepatic biliary obstruction. Out of the 41 icteric patients who were studied, a frequency of the presence of the LP-X was observed in 68.3% thus distributed: viral hepatitis 90,5% obstructive jaundice 85,7%, jaundice of uncertain etiology 37.6%; it was not present in 5 patients with hepatic cirrhosis and in the serum of 21 healthy volunteers. A significant association was found between the presence of LP-X and an abnormal curve of lipoproteins.

Adolescent↗
PubMedDate not supplied

Effect of recombinant human granulocyte colony-stimulating factor on variations of morphologically identifiable bone marrow cells in myelosuppressed mice.

To examine the effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on neutrophilic recovery after cytotoxic agents, the variations of marrow colony-forming units of granulocytes and macrophages (CFU-GM) and morphologically identifiable bone marrow cells were investigated in cyclophosphamide (CPA)-treated mice. In mice treated with CPA at 200mg/kg intraperitoneally (day 0), marked decreases in peripheral neutrophils and nucleated cells in the femur were observed. In the femur of mice treated with CPA, the greatest depression in number occurred firstly with CFU-GM and the most immature granulocytes, such as myeloblasts and promyelocytes, followed in turn by myelocytes, metamyelocytes and mature neutrophils. Administration of rhG-CSF for four successive days (days 1-4) after CPA treatment completely prevented the neutropenia. In the femur, rhG-CSF enhanced the recovery of progenitors and immature granulocytes from their depression in the order of their differentiation, and recovery of marrow neutrophils was also promoted. From these studies, we confirmed that rhG-CSF effects an increase in peripheral neutrophils by enhancing the proliferation and differentiation of CFU-GM and immature marrow granulocytes.

Animals↗