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Biomedical subjects

A Maki

Publications and source records attributed to A Maki.

At least 55 records · Page 3Linked to original sources
PubMed1996

Visualizing human motor activity by using non-invasive optical topography.

To visualize the spatial and temporal hemodynamic changes in the cortex associated with human cortical activity, a 12-channel non-invasive optical topography (NOT) measurement system has been developed. This NOT system, which is based on near-infrared light spectroscopy, can visualize changes in the oxygenation states of human tissue. The hemodynamic changes caused by human motor activity were measured and analyzed using NOT. Five subjects randomly performed unilateral finger opposition during 30 s for motor activation. When the subjects performed contralateral (right) finger movement, significant increases in oxygenated and total hemoglobin were observed around the motor cortex in the left fronto-central region. Significant differences in the hemodynamic changes were observed in four of the five subjects between for contralateral (right) and ipsilateral (left) finger movement around the motor cortex.

Adult↗
PubMed1995

Recurrent splenic artery aneurysms developing after aneurysmectomy without splenectomy: report of a case.

We report herein the case of a 47-year-old man who developed a huge splenic artery aneurysm (SAA) with splenomegaly, for which ligation of the splenic artery and partial aneurysmectomy was performed. A celiac arteriogram taken 2 months postoperatively revealed that two small aneurysms had developed in the collateral vessels, indicating that increased blood flow through the collateral circulation could be responsible for the formation of secondary aneurysms. This postoperative change suggests that the etiology is related to the SAA and thus, the possibility that aneurysms may develop in the collateral vessels following spleen-preserving procedures for SAA must be borne in mind and careful follow-up performed at regular intervals.

Aneurysm↗
PubMed1995

Bryostatin 1 induces apoptosis and augments inhibitory effects of vincristine in human diffuse large cell lymphoma.

Bryostatin 1 (Bryo1), a macrocyclic lactone and a protein kinase C activator, is isolated from the marine bryozoan Bugula neritina. In this study we describe its effect, alone or after sequential use with vincristine (VCR), on the human diffuse large cell lymphoma cell line WSU-DLCL2. Our results show that both Bryo1 and VCR induced apoptosis as demonstrated by morphological examination, DNA flow cytometry (FCM), and DNA fragmentation on agarose gel electrophoresis. Cells pretreated for 24 h with Bryo1 and then exposed to VCR showed an increase in apoptosis compared to cells that were exposed to Bryo1 or VCR alone. We also studied the effects of Bryo1, VCR and their combination on cell growth, bcl-2 and p53 expression, and inhibition of cell proliferation as measured by [3H]-thymidine incorporation. Cell analysis showed significant growth inhibition of WSU-DLCL2 cells by the Bryo1/VCR combination as compared to either agent alone. Immunocytochemistry (ICC) revealed that relative bcl-2 oncoprotein expression was decreased in cells treated with Bryo1, or VCR separately and was abolished by combining both drugs. When examined by ICC, WSU-DLCL2 cells were initially negative for the p53 protein. However, upon treatment with the above agents, the relative expression of p53 was moderate on Bryo1-or VCR-treated cells and strong on cells treated with the Bryo1/VCR combination. Cell proliferation as measured by [3H]-thymidine incorporation revealed significant inhibition of tumor growth by exposure to the agents when compared to the control. In contrast, Bryo1, VCR and their combination did not show any inhibition of normal bone marrow growth. These findings taken together, suggest that the exposure of WSU-DLCL2 cells to Bryo1 prior to treatment with VCR enhances apoptosis, a phenomenon which might be exploited for future therapies.

Antineoplastic Agents↗
PubMed1995

The bcl-2 and p53 oncoproteins can be modulated by bryostatin 1 and dolastatins in human diffuse large cell lymphoma.

The effects of dolastatin 10 (Dol10) and dolastatin 15 (Dol15) alone, and after treatment with bryostatin 1 (Bryo1), on human diffuse large cell lymphoma cell line (WSU-DLCL2) were studied. At a concentration of 1.0 ng/ml Dol10 and Dol15 showed significant growth inhibition (p < 0.05). This inhibition was intensified when the cells were pretreated for 24 h with 200 nM Bryo1. Bryo1, Dol10 and Dol15 induced apoptosis which was seen on morphological examination, by flow cytometry and DNA fragmentation on agarose gel electrophoresis. Cells pretreated with Bryo1 and then exposed to Dol10 showed an increase in apoptosis compared with cells that were treated with the Dol10, Dol15 alone. Immunocytochemistry revealed that WSU-DLCL2 cells express the bcl-2 oncoprotein constitutively. bcl-2 expression was decreased when cells were treated with Bryo1, Dol10 or Dol15 and abolished with the Bryo1/Dol10 combination. WSU-DLCL2 cells were negative for p53 protein expression, upon treatment with Bryo1 or Dol10, the expression of p53 was weak and moderate with the Bryo1/Dol10 combination. The inverse correlation between bcl-2 and p53 oncoprotein expression seems to be related to induction of apoptosis in this lymphoma cell line.

Antineoplastic Agents↗
PubMed1995

Spatial and temporal analysis of human motor activity using noninvasive NIR topography.

The effect of motor activity on the left fronto-central region of the human brain was analyzed spatially and temporally by using noninvasive near-infrared light (NIR) topography. The changes in oxygenation states caused by motor activity were measured using intensity-modulated NIR spectroscopy at ten measurement positions on the head surface. The subject randomly performed unilateral finger opposition for 30 s as motor stimulation. When the subject performed contralateral (right) finger movement, significant increases in both oxygenated hemoglobin (oxy-Hb) and total hemoglobin (total-Hb) and decreases in deoxygenated hemoglobin (deoxy-Hb) were observed in a particular area. By mapping the static topograms of the changes of each Hb and comparing them with an anatomical image of MRI, it was found that the particular area was located on the motor cortex along the central sulcus. By mapping the dynamic topograms of the changes of total-Hb, which reflect the cerebral blood volume, and analyzing the spatiotemporal hemodynamic changes associated with the brain activity, it was found that the regional change in cerebral blood volume in the primary motor area overlaps the global change around the motor cortex. These results demonstrate that NIR topography can be used to effectively observe the human brain activity.

Adult↗
PubMed1995

Induced expression of a ubiquitin COOH-terminal hydrolase in acute lymphoblastic leukemia.

To identify potential effector molecules of human B-cell differentiation, the acute lymphoblastic leukemia cells (Reh) were induced to terminal differentiation in vitro using the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate. Proteins of parent and differentiated Reh cells were mapped using powerful two-dimensional gel electrophoresis coupled with ultrasensitive silver stain. New protein (MW-pl; p34-5.3) spot was induced in the differentiated Reh cells. The NH2-terminal sequencing of this protein revealed 100% homology with the ubiquitin COOH-terminal hydrolase isozyme L1 (UCH-L1). The presence of UCH-L1 protein in the differentiated Reh cells but not in parent cells was confirmed by immunocytochemistry and Western blot. The cDNA for this enzyme was cloned from the differentiated Reh cells, and the UCH-L1 mRNA was detected in both parent and 12-O-tetradecanoylphorbol-13-acetate-induced cells. However, the message was more abundant in the differentiated cells than parent cells, indicating a posttranscriptional regulation. Until now, UCH-L1 was thought to be neuron-specific. The induced expression of UCH-L1 in differentiated Reh cells argues for a role of this enzyme, and the ubiquitin system, in B-cell differentiation.

Adolescent↗
PubMed1994

Complete obstruction of the inferior vena cava due to chronic relapsing pancreatitis: a case report.

A woman aged 62 with long history of chronic relapsing pancreatitis presented with swelling and ulcer in the lower limbs and occasional gastrointestinal bleeding. The radiological imaging showed complete obstruction of Inferior Vena Cava (IVC) at the level of the pancreas and well developed collateral vessels. Portal vein and splenic vein were also obstructed and superior mesenteric venous blood drained into the liver via coronary vein. She was originally found to have pancreas head tumor, which was not resectable. A palliative operation was performed, but histological examination of pancreatic specimen suggested only chronic inflammation and no evidence of malignancy. She was diagnosed as tumor-forming type chronic pancreatitis. Although SPV or SMV-PV obstruction has been recognized as a complication of chronic pancreatitis, IVC obstruction can occur by the same mechanism. This is the only case but one ever reported. Not only splenoportography but IVC-graphy will contribute to more precise understanding of patient's condition with chronic pancreatitis.

Chronic Disease↗
PubMed1994

Noninvasive evaluation of cytochrome c oxidase activity of the liver. Its prognostic value for hepatic resection.

OBJECTIVE: To clarify the relationship between the noninvasive evaluation of hepatic mitochondrial function, the redox tolerance test, and cytochrome c oxidase activity of the liver, focusing on surgical risk in hepatic resection. DESIGN: Six-month randomized clinical trial. SETTING: Inpatients in surgical department. STUDY PARTICIPANTS: Forty patients who underwent hepatic resection (n = 36) and other abdominal operations (n = 4). INTERVENTION: Preoperative, noninvasive: The redox tolerance test, which measures the changes in arterial ketone body ratio in response to 75 g of oral glucose loading. Intraoperative, invasive: Cytochrome c oxidase activity and energy charge of the liver. MAIN OUTCOME MEASURE: Correlation of the index in the redox tolerance test (RTI) with cytochrome c oxidase activity, both of which predict the postoperative course. RESULTS: The RTI values were negatively correlated with the maximal velocity (Vmax) and Michaelis constant (Km) values of cytochrome c oxidase activity. The maximal velocity and Michaelis constant values in patients with RTI values above or equal to 0.5 (group A, n = 29) were significantly lower than those in patients with RTI values below 0.5 (group B, n = 11). Eight (72.7%) of 11 patients in group B experienced postoperative complications. CONCLUSION: The RTI is a noninvasive method of assessing the hepatic energy metabolism and can be a useful index for evaluating surgical risk in hepatectomy.

Adenine Nucleotides↗
PubMed1994

Protein studies of human non-Hodgkin's B-lymphoma: appraisal by two-dimensional gel electrophoresis.

We have utilized two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) coupled with silver stain to identify cellular proteins in human non-Hodgkin's B-lymphoma (NHL). Five cell lines (SKDHL2B, WSU-DLCL2, WSU-NHL, WSU-FSCCL and SKLN1), representing four different NHL maturational stages and a normal Epstein-Barr virus (EBV)-transformed line of B-cell origin (SKLN1) were studied. The NHL lines were immunophenotyped using flow cytometry with lineage associated monoclonal antibodies. Whole cell lysates of the cell lines were subjected to 2-D PAGE analyses. The gels were analyzed with an image scanning computer and the qualitative differences of protein patterns were studied. Results revealed great similarities in patterns of the NHL lines. A master map containing common NHL-protein spots was constructed. When the map of each tumor line was compared to the master map, several protein spots were associated with each NHL-grade. Search for these proteins in the normal EBV-transformed B-cell line showed that only one of the proteins (S3; M(r)/pI 19/5.9) was present. Proteins that were detected in malignant NHL, but not in the normal EBV-line, could provide important information regarding the human NHL B-lymphocyte data-bases. Whether or not these proteins are definite malignant markers to distinguish between different NHL maturational stages needs further exploration through electroblotting and microsequencing.

Antigens, CD↗
PubMed1994

Role of cytosolic Ca2+ and protein kinases in the induction of the hsp70 gene.

The role of cytosolic Ca2+ ([Ca2+]i) and protein kinases in the hsp70 induction following heat shock was investigated in cultured rat proximal tubular epithelial (PTE) cells. Changes in [Ca2+]i were measured by digital imaging fluorescence microscopy using fura 2. Steady state levels of hsp70 mRNA were examined by either Northern or dot blot analyses. [Ca2+]i increased within 10 minutes and continued to increase following heat shock. The increases in [Ca2+]i were reduced in nominally Ca(2+)-free media with or without EGTA. [Ca2+]i also increased within 0.5 minutes following ionomycin, but then declined to normal levels by 1.0 to 1.5 minutes. Heat shock induced hsp70 mRNA within 15 minutes, which continued to increase up to three hours. Ionomycin also induced hsp70 mRNA, which peaked at 30 minutes, and gradually decreased thereafter. The hsp70 induction following heat shock was attenuated when extracellular Ca2+ was reduced. Chelation of [Ca2+]i by quin-2 also reduced the hsp70 induction. Inhibitors of protein kinases, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), calphostin C, genistein, and 2-aminopurine, also had inhibitory effects on the hsp70 induction. In contrast, a calmodulin inhibitor, chlorpromazine, had little effect. These results suggest that heat shock increases [Ca2+]i in rat PTE cells and that [Ca2+]i and protein kinases are involved in the hsp70 induction following heat shock.

Animals↗
PubMed1993

Optical CT imaging of hemoglobin oxygen-saturation using dual-wavelength time gate technique.

Our results may be summarized as follows: 1. In-vivo hemoglobin oxygen-saturation images of rat brain can be obtained using near-infrared light. 2. The transmitted light has multiple scattered components, which degrade spatial resolution, though most of the scattering can be excluded by a suitable time-gating technique. 3. The hemoglobin oxygen-saturation of the cerebellum is higher than that of the cerebrum in untreated anesthetized rats. Although further improvements in the technique should result in better resolution, we have demonstrated the feasibility of using near-infrared light to obtain in-vivo hemoglobin oxygen-saturation images.

Animals↗
PubMed1993

Induction of immediate early and stress genes in rat proximal tubule epithelium following injury: the significance of cytosolic ionized calcium.

This study was designed to investigate the influence of intracellular ionized calcium ([Ca2+]i) on the induction of c-fos, c-jun, c-myc, and hsp70 genes after oxidant stress induced by xanthine/xanthine oxidase (X/XOD) treatment or after heat shock using primary cultures of rat proximal tubule epithelium (PTE). X/XOD (500 microM/25 mU/mL) induced all of these genes; ionomycin also resulted in similar kinetics of induction of all genes. The expression of both c-fos following X/XOD treatment and hsp70 following heat shock was markedly decreased through chelation of [Ca2+]i by Quin 2/AM. The c-fos expression following X/XOD treatment was partly reduced by a protein kinase C inhibitor, staurosporine (ST), and markedly inhibited by another protein kinase inhibitor, 2-aminopurine (2AP), while both ST and 2AP markedly reduced hsp70 expression. The ADP-ribosylation transferase inhibitor 3-aminobenzamide had no effect on either c-fos or hsp70 expression. These results suggest that cell injuries leading to increased [Ca2+]i in PTE result in induction of c-fos, c-jun, c-myc, and hsp70; and that the activation of c-fos and hsp70 genes may be regulated by [Ca2+]i and [Ca2+]i-dependent protein kinases.

Animals↗
PubMed1992

Role of [Ca2+]i in induction of c-fos, c-jun, and c-myc mRNA in rat PTE after oxidative stress.

Oxidative stress plays an important role in various types of cell injury and tumor promotion. Cells respond to oxidative stress in many ways including changes in membrane organization, ion movements, and altered gene expression, all of which contribute to the subsequent fate of affected cells. In this study, we investigated the expression of the proto-oncogenes c-fos, c-myc, and c-jun, which play a key role in proliferation and differentiation, using primary cultures of rat proximal tubular epithelium exposed to oxidative stress generated by the xanthine/xanthine oxidase system. This system generates superoxide and H2O2 in the extracellular space stimulating the release of active oxygen species from inflammatory cells. c-fos mRNA was expressed within 15 min, peaked at 30 min, and returned to constitutive levels by 3 h. c-jun mRNA began to rise after 30 min, peaked at 120 min, and remained above the constitutive levels up to 180 min. c-myc mRNA expression was less affected by the treatment, with levels increasing gradually over the 180 min period. The expression of c-fos was inhibited by superoxide dismutase but not by catalase and was super-induced by cycloheximide. H2O2 alone did not induce any c-fos mRNA in this system. Chelation of extracellular ionized calcium by EGTA or of intracellular ionized calcium by Quin 2/AM resulted in a marked decrease of c-fos expression. Two protein kinase C inhibitors, H-7 and staurosporine, partly diminished the expression of c-fos, whereas a third, 2-aminopurine, which has a broader spectrum of inhibiting protein kinases, almost completely abolished it. A poly ADP-ribosylation inhibitor, 3-aminobenzamide, had no effect on c-fos expression in this system. Our results show that oxidative stress provokes sequential expression of c-fos, c-jun, and c-myc, mRNA in this order. This c-fos expression appears to be largely controlled by calcium ion movement, which could include protein kinase C activation. Another protein kinase or kinases also appear to play an important role.

Alkaloids↗