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Biomedical subjects

T Tajima

Publications and source records attributed to T Tajima.

At least 397 records · Page 22Linked to original sources
PubMed1988

Assay of rat plasma pyruvate kinase activity with luciferin-luciferase.

An assay method for pyruvate kinase in rat plasma is described. Plasma samples were incubated with ADP and phosphoenolpyruvate in Tris buffer solution. The ATP produced by pyruvate kinase was measured by photocounting after the addition of a commercially available luciferin-luciferase preparation. Interference by ATP or adenylate kinase originally present in the sample was removed by a high degree of dilution. The assay is sensitive, reproducible, and rapid, especially when used for large numbers of samples. By this method, pyruvate kinase activity in normal rats was determined to be 0.51 +/- 0.05 (n = 6) U/ml plasma. In rats fed a vitamin E-deficient basal diet for 7, 10, or 14 weeks, pyruvate kinase activities were 0.70 +/- 0.11, 1.64 +/- 0.51, and 4.28 +/- 0.85 (n = 6) U/ml plasma, respectively. This method appears to be useful for the determination of pyruvate kinase activity in nutritional or pharmacological studies.

Animals↗
PubMed1988

Concentrations of alpha-1-antichymotrypsin and other acute phase reactants in patients with gastric cancer.

The serum levels of alpha-1-antichymotrypsin, immunosuppressive acidic glycoprotein, acid soluble glycoproteins, and sialic acid as acute phase reactants (APRs) and carcinoembryonic antigen (CEA) as a cancer-producing glycoprotein were measured preoperatively in 245 patients with gastric cancer who underwent gastrectomy and were treated with postoperative adjuvant chemotherapy or immunochemotherapy. The patients were classified into four groups: group A had normal leverl of serum CEA and APRs; group B had abnormal CEA levels; group C had normal levels of CEA and one or more abnormal levels of APRs; and group D showed abnormal levels of CEA and one or more abnormal levels of APRs. Groups A and B showed good survival rates, but groups C and D had poor rates. The patients in groups A and C who received immunochemotherapy exhibited significantly better survival rates than those treated with chemotherapy. The pretreatment of levels of CEA and APRs have potential as aids in prognosis and in the selection of suitable immunopotentiators and anticancer drugs for cancer patients.

Acute-Phase Proteins↗
PubMed1988

[Role of autologous bone marrow transplantation in cancer chemotherapy].

Over the past 9 years, total number of 147 patients with various types of malignant solid tumors were treated 220 times with high-dose chemotherapy supported by autologous bone marrow transplantation. Two most frequently used chemotherapeutic protocols were: cyclophosphamide 1,600 mg/m2 + adriamycin 80 mg/m2 + ACNU 3 mg/kg and cyclophosphamide 1,600-2,400 mg/m2 + adriamycin 80 mg/m2 + CDDP 100-120 mg/m2. There were 89 patients with advanced and/or recurrent diseases. The overall response (CR + PR) rate was 44.1% with the complete response (CR) rate, being 11.8% among 68 evaluable patients in this group. The most favorable response was obtained in breast cancer patients with 77.3% response rate and 13.6% CR rate. Nearly 50% of patients with gastric, lung, gynecological and pediatric malignancies responded, whereas poor responses were observed in the cases of pancreato-biliary, colorectal, esophageal cancers and melanoma. In 8 complete responders, three are alive and well without any evidence of disease 5 years after the treatment. There were 58 patients who underwent this treatment in adjuvant settings. There are 5 patients with breast cancer who have been followed over 5 years after treatment. All of them are alive and well without any demonstrable diseases. Four of them were in stage IIIa and histologically examined axillary nodes were positive in 14/15, 11/17, 37/44, 22/25. Autologous bone marrow transplantation seems to be instrumental in shortening the period of myelosuppression, thus allowing safe dose escalation in chemotherapy. Adequacy of cryopreserved marrow as marrow inoculum was ascertained with mononuclear cell count, cellular viability, CFU-GM, CFU-E, BFU-E and CFU-Mk.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

The effects of non-cryopreservation on colony formation of committed progenitor cells of bone marrow.

Bone marrow from five prospective candidates for autologous bone marrow transplantation was subjected to short-term non-cryopreservation at room temperature, and mononuclear cell counts, cellular viability, CFU-GM, CFU-E, BFU-E and CFU-Mk were tested on days 0, 1, 2, 3, 5 and 7 of preservation. On day 5, mononuclear cell counts were over 60% with cellular viability of approximately 80%, and the number of CFU-GM colonies remained at approximately 45% of the original value. Decreases in the numbers of CFU-E, BFU-E and CFU-Mk colonies, however, were more rapid. On the average, 50% preservation could be maintained for only 2 days. Thus the common belief that the CFU-GM assay is the most reliable parameter for qualifying the marrow inoculum in marrow transplantation can be challenged. We suggest that CFU-E, BFU-E and CFU-Mk are more sensitive with CFU-Mk being the most reliable. Judged from the decreasing numbers of CFU-Mk colonies, 48 hours appears to be the maximum period for non-cryopreservation of marrow under conditions of the study at room temperature. Vulnerabilities of marrow progenitors seem to differ from cell lineage to cell lineage, and this must be taken into careful consideration in pursuing marrow transplantation.

Adult↗
PubMed1988

Use of Broviac/Hickman catheter for long-term venous access in pediatric cancer patients.

Forty-two indwelling central venous catheters were inserted in 29 pediatric patients with malignant solid tumors. Indications included pre- and postoperative parenteral nutrition, intensive chemo-radiotherapy and bone marrow transplantation. Fifteen of the central venous catheters (15 patients) were Broviac/Hickman and remaining 27 catheters (14 patients) were traditional Silastic. Accidental displacements occurred in seven of the 27 Silastics (26%), whereas no Broviac catheter was inadvertently pulled out. Overall complication rates, including infection, accidental removal, and occlusion of the catheter, were 9.6 per 1,000 Silastic use days and 0.35 per 1,000 Broviac use days. No deaths were related to catheter complications. For long-term angioaccess in pediatric cancer patient the Broviac catheter was demonstrated to have a lower complication rate than the traditional Silastic catheter.

Adolescent↗
PubMed1988

Carbachol depolarizes and accelerates pacemaker activity in the sinoatrial node of chicks treated with pertussis toxin.

Carbachol hyperpolarized the membrane of sinoatrial (SA) node cells from saline-treated chicks in a concentration-dependent fashion (10(-8)-10(-4) M). The rate of spontaneous impulse generation diminished in the presence of carbachol; complete inhibition (arrest) occurred at 10(-6) M. The hyperpolarization and negative chronotropic effect of carbachol (10(-8)-10(-6) M) were prevented by pretreatment of chicks with islet activating protein. Treatment with islet activating protein, which inactivates the guanine nucleotide binding proteins Gi and Go unmasked "stimulant" effects at high (greater than or equal to 10(-5) M) concentrations of carbachol. The stimulant effects included membrane depolarization and an acceleration of spontaneous impulse generation detected at 10(-5) and 10(-4) M carbachol, respectively. Because the depolarization and acceleration produced by carbachol occurred in the presence of propranolol, they are independent of endogenous catecholamines. As with the inhibition of the SA node, the stimulation by carbachol was mediated by muscarinic receptors and prevented by atropine. We speculate that the depolarization of SA node cells by carbachol, as in left atrium, may be mediated by products of phosphoinositide metabolism because phosphoinositide hydrolysis is activated at the same concentrations (greater than or equal to 10(-5) M). The ionic mechanism for the carbachol-induced depolarization and acceleration in SA node cells is not known. By analogy with results in left atrial cells from islet activating protein-treated animals, the mechanism would involve an increased intracellular Na+ activity and stimulation of Na-Ca exchange.

Animals↗
PubMed1988

[A case of non-jaundice ampullary carcinoma with prominent lymphatic infiltration].

A case of a non-jaundiced ampullary carcinoma with a unique tumor spread is reported. A 3.2 X 1.0 cm-sized tumor at the ampulla of Vater was resected in a 64-year-old female. The primary focus of the well differentiated adenocarcinoma was confined to the intraampullary common channel, but the most of the tumor consisted of lymphatic permeation. A wide spread lymphogenous metastases had been noticed at operation, and the patient died nine months thereafter from metastases of the brain. The mechanism which prevented jaundice from developing in this case might be due to the unique way in which this tumor spread, without obstruction via the lymphatic space and only stenosing the bile duct.

Adenocarcinoma↗
PubMed1987

Regional cerebral blood flow of acute carbon monoxide poisoning in cats.

The mechanism of selective vulnerability of the cerebral white matter and pallidum in acute carbon monoxide (CO) poisoning was experimentally investigated by measuring regional cerebral blood flow (rCBF) with the iodo-[14C]antipyrine method. A CO group consisting of five cats was exposed to 0.2%-0.3% CO gas and the rCBF was measured when moderate systemic hypotension (70-80 mm Hg) occurred; because systemic hypotension of this level during exposing to 0.2%-0.3% CO gas induces typical cerebral lesions of acute CO poisoning in almost all cats [Okeda et al. Acta Neuropathol (Berl) 54:1-10 (1981)]. Controls were a hypotension group of three cats with moderate systemic hypotension induced for 1 h without CO exposure, and a control group of five cats which inhaled only air for 2 h. The rCBF of each structure in the CO and hypotension groups was evaluated as a percentage of that of the control group. The rCBF of the CO group exhibited a wide range (68%-127%) according to the structures examined, and the mean (94.6%) was large compared with that (range: 53%-82%, mean: 67.4%) of the hypotension group. In the CO group, the examined brain structures where divided in two groups according to the rCBF values; low-value structures and high-value structures. There was significant (P less than 0.05) difference between rCBFs of both the structure groups. The cerebral white matter and pallidum belonged to low-value structures, and these rCBFs did not show any significant difference from those of other structures in this structure group.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1987

Positive inotropic effects of acetylcholine and BAY K 8644 in embryonic chick ventricle.

BAY K 8644 augmented Ca2+-dependent action potentials and evoked a positive inotropic effect in embryonic chick ventricle. These effects are consistent with the properties of this Ca channel "agonist" whose actions are independent of adenosine 3',5'-cyclic monophosphate (cAMP)-dependent phosphorylation. At low to intermediate concentrations (10(-8) to 10(-6) M), the cholinergic agonists acetylcholine, carbachol, and oxotremorine inhibit Ca2+-dependent action potentials and contractions in embryonic ventricle only in the presence of drugs that cause cAMP accumulation. The prediction that low to intermediate concentrations of these cholinergic agonists should not inhibit the effects of BAY K 8644 on Ca2+-dependent action potentials and contractions was borne out experimentally. This result is consistent with the cAMP hypothesis for muscarinic inhibition. It is noteworthy that all cholinergic agonists tested evoked a positive inotropic effect at high concentrations (greater than 10(-6) M) in the presence or absence of BAY K 8644. The positive inotropic effect was initiated by muscarinic receptors for it was blocked by atropine and was independent of endogenous catecholamines, since it occurred in the presence of propranolol. It is speculated that the positive inotropic effect of muscarinic agonists in embryonic heart muscle is related to stimulation of phosphoinositide metabolism.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1987

Pertussis toxin-insensitive phosphoinositide hydrolysis, membrane depolarization, and positive inotropic effect of carbachol in chick atria.

Muscarinic agonists can stimulate rather than inhibit cardiac muscle in some preparations. In left atria from hatched chicks, treatment with pertussis toxin reversed the membrane action of carbachol from hyperpolarization to depolarization and reversed the inotropic effect of carbachol from negative to positive. Acetylcholine also depolarized the membrane and increased the force of contraction in atria from pertussis-toxin-treated chicks although oxotremorine did not. These cholinergic responses were blocked by atropine but not by adrenoceptor antagonists, suggesting that they are mediated via muscarinic receptors and are not due to actions of endogenously released catecholamines. Muscarinic receptor stimulation leads to two distinct biochemical responses in chick atria: inhibition of adenylate cyclase and activation of phosphoinositide (PI) hydrolysis. The former is lost in atria from pertussis-toxin-treated chicks, whereas the PI response persists. The pharmacologic characteristics of the PI response resemble those of the depolarization and positive inotropic response. Both are insensitive to blockade by pertussis toxin, require high concentrations of carbachol, and are elicited by acetylcholine but not by oxotremorine. The present study suggests that muscarinic agonist-induced PI turnover may be responsible for the membrane depolarization and positive inotropic effects of carbachol and acetylcholine; that an increase in Na+ conductance underlies these responses; and that it is stimulated either by an increase of intracellular calcium mobilized by inositol triphosphate and/or by activation by protein kinase C.

Adenylate Cyclase Toxin↗
PubMed1987

Candidate rotavirus vaccine (rhesus rotavirus strain) in children: an evaluation.

Fifty children, 3 months to 12 years of age, were given an experimental, orally administered, live attenuated rotavirus vaccine. Overall evidence of vaccine effectiveness as judged by vaccine virus shedding or a serologic response was seen in 82% of vaccinees. No clinical illness was seen in the rotavirus vaccinees when compared with 40 concurrently studied control children. No transmission to control children was observed even with close daily contact in a day-care setting. Young infants, generally less than 1 year of age, who had not previously experienced wild-type rotavirus infection shed significantly more vaccine virus. Limitation of virus shedding in those already exposed may be related to a prompt copro-IgA response which was significantly elevated by three days after vaccination. In summary, the development of this rotavirus vaccine, rhesus rotavirus-MMU-18006, is a promising step in the development of immunoprophylaxis against this major enteric pathogen.

Antibodies, Viral↗
PubMed1987

Positive vs. negative inotropic effects of carbachol in avian atrial muscle: role of Ni-like protein.

Treatment with pertussis toxin not only prevents inhibitory effects (e.g., reduced adenylate cyclase activity, decreased voltage-dependent Ca2+ entry, increased K+ efflux, and negative inotropy) but also unmasks stimulant effects (e.g., membrane depolarization and positive inotropy) of carbachol in chick atria. Pertussis toxin prevents transducer proteins (Ni and No) from linking muscarinic receptors to either adenylate cyclase and Ca2+ channels or K+ channels. However, pertussis toxin treatment does not block N proteins linking the muscarinic receptor to stimulant membrane effects. Membrane depolarization by carbachol, attributed by others to increased Na+ entry, may stimulate Na-Ca exchange and positive inotropy, perhaps by activation of phospholipase D. Alternatively, carbachol could increase inositol triphosphate content and thereby release Ca2+ from the sarcoplasmic reticulum to increase the force of contraction. The ability of carbachol to increase phosphoinositide hydrolysis is resistant to pertussis toxin. The second-messenger role of phospholipid metabolites provides a foundation for testing the hypothesis that such metabolites are eventually involved in the stimulant actions of carbachol seen in pertussis toxin-treated preparations.

Adenylate Cyclase Toxin↗
PubMed1987

A case of paroxysmal rate dependent intra-His bundle block.

We present a symptomatic bradycardia-dependent paroxysmal atrio-ventricular (A-V) block occurred within the bundle of His. Paroxysmal A-V block was caused by atrial or ventricular premature beats and also by sinus slowing. This case also showed tachycardia-dependent A-V block within the bundle of His. We also discussed the controversial mechanisms of paroxysmal A-V block.

Bundle-Branch Block↗