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Biomedical subjects

J Tanaka

Publications and source records attributed to J Tanaka.

At least 649 records · Page 36Linked to original sources
PubMed1988

Exocrine pancreatic function test by endoscopic retrograde aspiration of pure pancreatic juice.

The validity of endoscopic retrograde aspiration of pure pancreatic juice (PPJ) as an exocrine pancreatic function test was evaluated in terms of coefficients of variation in control subjects, reproducibility on repeated examinations, and sensitivity for detecting patients with chronic pancreatitis (CP). PPJ was obtained from, nine control subjects, four patients with suspected CP and 13 with CP. PPJ was collected from within the pancreatic duct by endoscopic retrograde catheterization of the papilla at 2-min intervals for 20 minutes after a bolus intravenous injection of secretin (1U/kg) and then for further 20 minutes after a bolus intravenous injection of CCK-PZ (1U/kg). It was recognized that endoscopic aspiration of PPJ was at least as useful and reliable as the traditional pancreozymin secretin test. Useful parameters included 10-min secretory volume and 10-min bicarbonate output after secretin stimulation, and 10-min enzyme output after CCK-PZ stimulation (lipase output showed higher sensitivity than amylase output). Maximal bicarbonate concentration showed poorer reproducibility and sensitivity despite better coefficients of variation. Lower limits in controls (mean-1.5SD) were 22.5ml for 10-min secretory volume, 2.7mEq for 10-min bicarbonate output, 24.5 x 10(3)U for 10-min amylase output and 3.4 x 10(3)IU for 10-min lipase output.

Adult↗
PubMed1988

Inhibitory effect of dimethyl sulfoxide on the proliferation of cultured arterial smooth muscle cells: relationship to the cytoplasmic microtubules.

Our preliminary study has shown that dimethyl sulfoxide (DMSO) has an inhibitory effect on the proliferation of cultured arterial smooth muscle cells and promotes phenotypic modulation from the synthetic state to the contractile state. In the present study we have examined the effect of DMSO with special attention to relationship between cell growth and cytoplasmic microtubules. DMSO inhibited DNA synthesis and cell division, and concomitantly promoted microtubule assembly. Initiation of DNA synthesis and cell division of nonproliferating cells by platelet-derived growth factor (PDGF) was also inhibited in the presence of 1% DMSO. A 12-hr incubation with 10(-6) M colchicine caused disruption of microtubules; however, pretreatment with 1% DMSO for 24 hr prevented the disruption, indicating that DMSO has a stabilizing action on microtubules. A 24-hr exposure to PDGF resulted in microtubule depolymerization, while the addition of 1% DMSO prevented the depolymerization. These results suggest that DMSO inhibits DNA synthesis of cultured smooth muscle cells by stabilizing cytoplasmic microtubules.

Animals↗
PubMed1988

Inhibitors of prostaglandin synthesis inhibit growth of human cytomegalovirus and reactivation of latent virus in a productively and latently infected human cell line.

Indomethacin and tetracaine, inhibitors of prostaglandin synthesis, inhibited production of infectious human cytomegalovirus (HCMV) in a human thyroid papillary carcinoma cell line (TPC-1) by 99.9% when added to cultures at the concentration of 2 x 10(-4) M during the first 24 hr after infection. Although immediate early virus proteins were synthesized at similar molar ratios in mock- and compound-treated cultures, induction of HCMV-specific DNA polymerase (one of the early virus proteins) was inhibited by treatment with these compounds, suggesting that the early stages of the virus growth cycle are most likely to be under the control of indomethacin or tetracaine action. We have previously developed an in vitro HCMV latency model system in TPC-1 cultures. This system was used to study the effect of these compounds on reactivation of the latent virus. When TPC-1 cultures preheated for 48 hr at 40.5 degrees were infected with HCMV and incubated at 40.5 degrees, the cultures could be maintained for 30 days without detection of infectious virus. The latent HCMV was reactivated within 10 days by reducing the incubation temperature from 40.5 to 37 degrees. However, when the latently infected cultures were treated with indomethacin or tetracaine immediately after being shifted to 37 degrees, reactivation of the latent virus was not observed.

Antigens, Viral↗
PubMed1988

Lateral hypothalamic area and paraventricular nucleus connections with subfornical organ neurons: an electrophysiological study in the rat.

The neural pathways from the lateral hypothalamic area (LHA) to the hypothalamic paraventricular nucleus (PVN) mediated by subfornical organ (SFO) neurons were examined in urethane-anesthetized male rats in order to determine the excitability of vasopressin (VP)-secreting neurons in the PVN. Microinjection of angiotensin II (AII) into the LHA excited the activity of nearly half (n = 8) of the SFO neurons (n = 18) activated antidromically by electrical stimulation of the PVN. Microinjection of AII into the LHA also caused excitation of approximately one-quarter (n = 11) of putative VP-secreting neurons (n = 45) in the PVN while the excitatory responses of the putative VP-secreting neurons were blocked or attenuated by pretreatment with the AII antagonist, saralasin (Sar), in the SFO. Electrical stimulation of the LHA, on the other hand, produced excitation (n = 17) or inhibition (n = 14) of the putative VP-secreting neurons (n = 52) in the PVN. About half of the excitatory responses to LHA stimulation were blocked or attenuated by pretreatment with Sar in the SFO, whereas the inhibitory responses were not affected. These results show some possible connections between the LHA and PVN, and suggest that AII-sensitive LHA neurons with efferent projections to the SFO may act to enhance the excitability of putative VP-secreting neurons in the PVN via an excitatory influence on the AII-sensitive SFO neurons.

Action Potentials↗
PubMed1988

Recovery curve of the H-reflex in normal infants, central coordination disturbance cases and cerebral palsy patients within the first year of life.

The differences in the recovery curve of the H-reflex in the gastrocnemius within the first year of life were evaluated among 81 normal controls, 40 infants with cerebral palsy and 11 infants with central coordination disturbance (CCD). In normal controls, the recoveries for the groups of under 6 months of age were more marked than those for the groups of 6 months and over of age, with interstimulus intervals of 400 msec and less. The results for the infants with cerebral palsy showed more rapid recovery and facilitation of the reflex compared to those in the normal control infants throughout the first year of life. The recovery curves for the infants with CCD were similar to those for the infants with cerebral palsy in part. It was considered that the recovery curve of the H-reflex might provide additional information for evaluating an infant's motor function.

Age Factors↗
PubMed1988

Intravenous injection of flunitrazepam for status epilepticus in children--two case reports.

Two cases of status epilepticus are reported, whose seizures responded well to the injection of flunitrazepam. One patient had generalized tonic clonic seizures and the other had partial seizures. The improvement of their condition was confirmed by both clinical and electroencephalographic examinations. There were no serious side effects observed. Flunitrazepam might have a potential efficacy for the treatment of status epilepticus of both generalized and partial seizures.

Electroencephalography↗
PubMed1988

Influence of microinjection of corticosterone into ventromedial hypothalamus on hepatic acetate metabolism in rabbits.

Corticosterone was injected into the ventromedial hypothalamus (VMH) of rabbits, and changes in hepatic acetate metabolism were studied. The microinjection of corticosterone with seasame oil into the VMH of intact rabbits increased the rates of 14C transfer from 14C-1-acetate into CO2, glucose, ketone bodies, triglyceride, free cholesterol, free fatty acids and phospholipids but decreased those of 14C transfer into cholesterol ester. However, corticosterone injected into the VMH of rabbits with VMH lesions or the parietal cortex of intact rabbits was without effect on the hepatic acetate metabolism. From these results it might be suggested that the VMH is an integral part of the corticosterone-sensitive brain regulator system in the hepatic acetate metabolism.

Acetates↗
PubMed1988

Cerebellar involvement in murine sphingomyelinosis: a new model of Niemann-Pick disease.

Mice with sphingomyelinosis (spm) with a C57BL/KsJ inbred background showed hepatosplenomegaly as early as four weeks (wk) of age and cerebellar signs around seven wk. Almost all animals died by 14 wk. Sudanophilic lipid accumulated in the liver, spleen, and lymph nodes as well as in the brain. The striking neuropathological change was a marked atrophy of the cerebellum, where Purkinje cells were predominantly involved. Loss of Purkinje cells started at the age of six wk before the cerebellar signs had become evident clinically. The cell loss appeared to be more marked in the vermis than in the hemispheres. Cytoplasmic inclusions in most cells consisted of myelin figures composed of concentric membranous lamellae. These inclusions were found mainly in the Purkinje cells at an early stage; thereafter, they were widely distributed in the granule cells, Golgi cells, some glial cells, macrophages and endothelial cells. The neuronal inclusions were frequently located in the vicinity of the Golgi apparatus; there were no unusual mitochondrial configurations. The clinicopathological characteristics of the mutant mice are similar to those of the human Niemann-Pick disease type C.

Animals↗
PubMed1988

Myelin basic protein as a possible marker for oligodendroglioma.

To search for a marker for oligodendroglioma, immunohistochemical analysis of myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP) were performed on tissues from 38 oligodendrogliomas. MBP was detected in 14 such tumors, positive cells being characterized by having rather rich cytoplasm containing a large nucleus and a prominent nucleolus. They seemed to be relatively poorly differentiated cells corresponding to oligodendroglioma grade II in the WHO classification, and appeared to have some cytological resemblance to immature oligodendrocytes in the newborn brain. Mature grade I tumor cells with a small dark nucleus and a perinuclear halo, and grade III anaplastic cells were MBP-negative. GFAP-positive cells were also found in tumors containing MBP-positive cells. A double immunostain for MBP and GFAP demonstrated that some tumor cells were simultaneously stained with both. Presumably the oligodendroglioma cells that showed such dual immunostaining would intrinsically express a myelin-forming glial phenotype. MBP may be applicable as a marker for oligodendrogliomas.

Biomarkers, Tumor↗
PubMed1988

Nucleotide sequence and expression of the Enterobacter aerogenes alpha-acetolactate decarboxylase gene in brewer's yeast.

The nucleotide sequence of a 1.4-kilobase DNA fragment containing the alpha-acetolactate decarboxylase gene of Enterobacter aerogenes was determined. The sequence contains an entire protein-coding region of 780 nucleotides which encodes an alpha-acetolactate decarboxylase of 260 amino acids. The DNA sequence coding for alpha-acetolactate decarboxylase was placed under the control of the alcohol dehydrogenase I promoter of the yeast Saccharomyces cerevisiae in a plasmid capable of autonomous replication in both S. cerevisiae and Escherichia coli. Brewer's yeast cells transformed by this plasmid showed alpha-acetolactate decarboxylase activity and were used in laboratory-scale fermentation experiments. These experiments revealed that the diacetyl concentration in wort fermented by the plasmid-containing yeast strain was significantly lower than that in wort fermented by the parental strain. These results indicated that the alpha-acetolactate decarboxylase activity produced by brewer's yeast cells degraded alpha-acetolactate and that this degradation caused a decrease in diacetyl production.

Base Sequence↗
PubMed1988

Effects of partial ischemia and reflow on mitochondrial metabolism in rat liver.

To clarify the effects of partial ischemia and reflow on the mitochondrial metabolism of the rat liver, the afferent vessels supplying the left lateral and left half of medial lobes were occluded and then reperfused after given time periods of ischemia (30, 60, 90 and 120 min, groups A, B, C and D, respectively). Samplings were taken at 0, 10 and 60 min after reperfusion. The energy charge levels of ischemic lobes decreased rapidly from 0.85 +/- 0.01 in the sham group to 0.38 +/- 0.11, 0.35 +/- 0.07 and 0.34 +/- 0.06 in groups B, C and D, respectively. The phosphorylative activities of mitochondria isolated from ischemic lobes decreased gradually along with the time of ischemia. The reversal of mitochondrial function and energy charge levels following reperfusion was noted in groups A and B. In nonischemic lobes, the phosphorylation rate (nmol ATP/mg/min) increased from 90 +/- 6 in sham group to 125 +/- 12 and 130 +/- 9; 131 +/- 5 and 130 +/- 6; 123 +/- 6 and 122 +/- 17, and 138 +/- 6 and 138 +/- 13 at 10 and 60 min after reflow in groups A, B, C and D, respectively (p less than 0.05). The energy charge level of nonischemic lobes decreased from 0.85 +/- 0.01 of sham group to 0.80 +/- 0.03 in group D (p less than 0.05). From these results, it is concluded that the transitional zone for the reversal of mitochondria function and energy metabolism following prolonged liver ischemia appears at around 60 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗