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Biomedical subjects

A Shibata

Publications and source records attributed to A Shibata.

At least 253 records · Page 14Linked to original sources
PubMed1993

Prediction of the ability to purge clonogenic B cell lymphoma from normal BM in vitro by heat: their survival curves correspond to a curve reflecting mortality in humans.

To develop new purging regimens for ABMT the ability to predict potential for purging of tumor cells from BM is important. Since the sensitivity of human B cell lymphoma to hyperthermia is not known, we examined its effect on the growth of B cell lymphoma cell lines (Raji and Daudi) in vitro to evaluate potential for purging clonogenic tumor cells from normal marrow by heat, using a limiting dilution assay to measure log depletion of tumor cells in a 20-fold excess of normal BM. When exposed to heat (42-43 degrees C) for 120 min, both clonogenic Raji and Daudi cells were dramatically reduced (a 4-to-6 log reduction) with time, whereas at 42 degrees C over half and at 43 degrees C 10% of normal granulocyte-macrophage progenitor cells survived for the same time period. This high level of lymphoma cell depletion by heat correlated with that of immunologic and pharmacologic studies. In addition, these survival curves during heating were found to correlate with the Gompertz-Makeham formula--a law of human mortality. This formula may be useful in predicting the purging effect of heat. These results suggest that in vitro hyperthermia could be applied effectively for the elimination of residual, clonogenic lymphoma cells in autologous marrow grafts before ABMT.

Bone Marrow Purging↗
PubMed1993

[A case of dual origin of the left anterior descending coronary artery from the left and right coronary arteries with variant angina].

We present a case of a 68-year-old male inflicted with a rare anomaly of the coronary artery. He had been suspected to have worsening effort angina and underwent urgent cardiac catheterization. The coronary angiography revealed 75% stenosis in the first diagonal branch. The left anterior descending artery was terminated in the mid portion and did not reach the apex. Instead, an anomalous coronary artery from the portion just proximal to the right coronary artery reached the apex. After cardiac catheterization, nocturnal chest pain at rest started to occur frequently. We suspected that vasospasm may have occurred because ST segment elevations in leads II, III, aVF were recorded on the electrocardiogram. Administration of diltiazem (120 mg per day) suppressed angina. Exercise stress electrocardiogram and thallium-201 myocardial scintigram did not show apparent ischemia. This case suggests that we must consider the presence of coronary vasospasm even in patients with clinically-supposed effort angina, to be possibly due to vasospasm occurring in anomalous coronary arteries.

Aged↗
PubMed1993

Studies on the bone marrow cells from an excised pipe bone.

Samples of rib bone were collected and preserved under various conditions. The effect of preserving a piece of bone on the yield of hematopoietic stem cells was analyzed. Bone marrow cells were collected by means of flushing the bone marrow cavity with medium. The initial number of nucleated bone marrow cells collected from the donor's excised rib ranged from 0.8 x 10(8) to 2.3 x 10(8) per 1 cm of rib with an average of 1.21 x 10(8) (n = 7). In addition, the initial number of mononuclear bone marrow cells ranged from 1.1 x 10(7) to 4.8 x 10(7) per 1 cm of rib with an average of 2.47 x 10(7) (n = 7). The percentage loss of mononuclear bone marrow cells from rib preserved in medium for 48 hours at 4 degrees C, was less than 30%. A colony-forming assay by the methylcellulose method, complemented with r-G-CSF, r-GM-CSF, r-IL3, r-IL6, and r-erythropoietin, was done serially using bone marrow buffy-coat cells. These cells were obtained from the pieces of rib that were stored under various conditions. The number of CFU-GM and BFU-E that proliferated in this culture was 41.1 +/- 5.5 and 15.2 +/- 2.7 per dish. If the bone was preserved at 4 degrees C for 48 hours following excision, the recovery of CFU-GM and BFU-E from the bone marrow cells was greater than 50%. The effect of cryopreserving bone marrow mononuclear cells on the yield of hematopoietic cells was also analyzed. The percentage loss of proliferated hematopoietic cells by cryopreservation was less than 30% for bone marrow cells. Bone marrow cells were collected from pieces of rib obtained from cadaveric donors by means of the same method. The average number of nucleated bone marrow cells and MNCs was 1.26 x 10(7) and 2.30 x 10(7) per 1 cm of rib, respectively. The average number of CFU-GM and BFU-E that was detected by the colony-forming assay was 33.4 +/- 5.35 and 11.7 +/- 1.75 per dish, respectively. The percentage loss of proliferated hematopoietic cells by cryopreservation was less than 40% for bone marrow cells from cadaveric donors. These data, which reveal that hematopoietic bone marrow stem cells could be collected from a piece of pipe bone that was without circulation, suggest that it is possible to use pipe bone from cadaveric donors as a source of hematopoietic stem cells for bone marrow transplants.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1993

[A case of infective endocarditis in which a new vegetation appeared on a different site during chemotherapy].

42-year-old man, who had been febrile for about a month, was admitted to our hospital. Laboratory testing showed leukocytosis and high titer of CRP. Streptococcus sanguis II was detected in his blood culture. According to the echocardiogram, he had a vegetation on the anterior mitral leaflet, so he was diagnosed as having infective endocarditis. Antibiotic susceptibility test using the disc method showed (3+) response to penicillin G. After intravenous administration of 20 million units of penicillin G for 3 weeks, a new vegetation appeared on the posterior mitral leaflet although the one on the anterior mitral leaflet had disappeared. Imipenem/cilastatin was administered until the acute phase reactants became negative. But the vegetation did not disappear, so he had vegetectomy. This is the first case report of infective endocarditis in which a new vegetation appeared on a different site despite the disappearance of the first lesion during chemotherapy.

Adult↗
PubMed1993

[Platelets-morphology, shape changing factor, and platelet agglutinating factor. TTP Research Group].

The morphology of circulating platelets in thrombotic thrombocytopenic purpura (TTP) was studied, and basic mechanism of the characteristic shape abnormality found in TTP was investigated in in vitro condition. The platelet shape was spineless sphere (spherical platelets without pseudopods), and shape change persisted 2 months after remission. This type of platelets were produced by long term of activation of normal resting platelets by several agonists except ADP, and induced by dysfunction of both microtubules and microfilaments. These suggest that the shape change in TTP is not specific, but a good parameter for the activity of TTP. PAF activity by the method of Kelton et al. (1984) was detected in only 1 out of 30 samples from 10 patients. PSCF activity was found in 9 out of 29 samples from 10 patients independently from disease activity. Both activities does not reflect the activity of TTP.

Blood Coagulation Factors↗
PubMed1993

[Interferon therapy for chronic myelogenous leukemia].

Interferon alpha (IFN alpha) has been used in the treatment of chronic myelogenous leukemia (CML). The initial trial was made in 1983 by Talpaz et al. Their first report suggested that IFN alpha treatment could achieve high hematological remission. The cause of the effect was unclear, but may be mediated through interaction cell surface membrane and inhibitory protein production. IFN alpha was related to some T cell immunity, and could be taken to be Ph1 positive cell inhibition by normal T cell. Although IFN alpha therapy has limited use with get Ph1 negative hematopoiesis, intensive treatment of this kind is needed to minimize Ph1 clone, using various therapy combination with IFN alpha.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Biphasic effects of alcohols on the phase transition of poly(L-lysine) between alpha-helix and beta-sheet conformations.

Poly(L-lysine) exists as a random-coil at neutral pH, an alpha-helix at alkaline pH, and a beta-sheet when the alpha-helix poly(L-lysine) is heated. The present Fourier-transform infrared (FTIR) study showed that short-chain alcohols (methanol, ethanol, and 2-propanol) partially transformed alpha-helix poly(L-lysine) to beta-sheet when their concentrations were low. At higher concentrations, however, these alcohols reversed the reaction, and the alcohol-induced beta-sheet was transformed back to alpha-helix structure. The reversal occurred at 1.40 M methanol, 0.96 M ethanol, and 0.55 M 2-propanol. The alcohol effects on the secondary structure were further investigated by circular dichroism (CD) on the thermally induced beta-sheet poly(L-lysine). Methanol, ethanol, and 1-propanol, but not 1-butanol, shifted the negative mean-residue ellipticity at 217 nm of the beta-sheet poly(L-lysine) to the positive side at low concentrations of the alcohols and to the negative side at high concentrations. With 1-butanol, only the positive-side shift was observed. The positive-side shift at low concentrations of alcohols indicates enhancement of the hydrophobic interactions among the side chains of the polypeptide in the beta-sheet conformation. The negative-side shift indicates a partial transformation to alpha-helix. The shift from the positive to negative side occurred at 7.1 M methanol, 4.6 M ethanol, and 3.1 M 1-propanol. The alcohol concentrations for the beta-to-alpha transition were higher in the CD study than in the IR study.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Propanol↗
PubMed1992

The local anesthetic tetracaine destabilizes membrane structure by interaction with polar headgroups of phospholipids.

The effect of the local anesthetic tetracaine at less than 10 mM on the water permeability of the phospholipid membrane was examined using liposomes composed of various molar ratios of negatively charged cardiolipin to electrically neutral phosphatidylcholine by monitoring their osmotic shrinkage in hypertonic glucose solution at 30 degrees C. The concentration of tetracaine causing the maximum velocity of shrinkage of liposomes increased with increase in the molar ratio of cardiolipin. Tetracaine increased the zeta-potential of the negatively charged liposomal membrane toward the positive side due to the binding of its cationic form to the negatively charged polar headgroups in the membrane. The maximum velocity of water permeation induced by osmotic shock was observed at essentially the same tetracaine concentration giving a zeta-potential of the liposomal membrane of 0 mV. These concentrations were not affected by change in the sort of acyl-chain of phospholipids in the liposomes when their negative charges were the same. These results suggests that the membrane integrity is governed mainly by the electrical charge of phospholipid polar headgroups when phospholipid bilayers are in the highly fluid state, and that positively charged tetracaine molecules neutralize the negative surface charge, lowering the barrier for water permeation through phospholipid bilayers.

Cardiolipins↗
PubMed1992

The alpha-helix to beta-sheet transition in poly(L-lysine): effects of anesthetics and high pressure.

Poly(L-lysine) exists in a random-coil formation at a low pH, alpha-helix at a pH above 10.6, and transforms into beta-sheet when the alpha-helix polylysine is heated. Each conformation is clearly distinguishable in the amide-I band of the infrared spectrum. The thermotropic alpha-to-beta transition was studied by using differential scanning calorimetry. At pH 10.6, the transition temperature was 43.5 degrees C and the transition enthalpy was 170 cal/mol residue. At pH 11.85, the measurements were 36.7 degrees C and 910 cal/mol residue, respectively. Volatile anesthetics (chloroform, halothane, isoflurane and enflurane) partially transformed alpha-helix polylysine into beta-sheet. The transformation was reversed by the application of hydrostatic pressure in the range of 100-350 atm. Apparently, the alpha-to-beta transition was induced by anesthetics through partial dehydration of the peptide side-chains (beta-sheet surface is less hydrated than alpha-helix). High pressure reversed this process by re-hydrating the peptide. Because the membrane spanning domains of channel and receptor proteins are predominantly in the alpha-helix conformation, anesthetics may suppress the activity of excitable cells by transforming them into a less than optimal structure for electrogenic ion transport and neurotransmission. Proteins and lipid membranes maintain their structural integrity by interaction with water. That which attenuates the interaction will destabilize the structure. These data suggest that anesthetics alter macromolecular conformations essentially by a solvent effect, thereby destroying the solvation water shell surrounding macromolecules.

Anesthetics↗
PubMed1992

Immunoaffinity purification and cDNA cloning of human platelet prostaglandin endoperoxide synthase (cyclooxygenase).

The cDNA for prostaglandin endoperoxide synthase (cyclooxygenase) was cloned from human platelets by the polymerase chain reaction amplification method, and the primary structure of the enzyme was deduced from the nucleotide sequence. The enzyme was composed of 599 amino acids including 23-amino acid signal sequence, and the calculated molecular weight of the mature protein was 65,995. The enzyme was immunoaffinity-purified from human platelets. The N-terminal amino acid sequence determined by Edman degradation was Ala-Asp-Pro-Gly-Ala-Pro-Thr-Pro-, and the result confirmed the primary structure of the enzyme, which was deduced from the cDNA sequence.

Acetylation↗
PubMed1992

Circulating thrombomodulin as a novel endothelial cell marker: comparison of its behavior with von Willebrand factor and tissue-type plasminogen activator.

Circulating thrombomodulin is a novel endothelial cell marker, which may reflect the endothelial injury. Plasma levels of thrombomodulin were quantitated by an enzyme-linked immunosorbent assay (ELISA) in patients with hematological malignancies, liver disease, diabetes mellitus, collagen disease, thrombotic disease, and disseminated intravascular coagulation (DIC), and the thrombomodulin values were compared with those of von Willebrand factor antigen (vWf:Ag) and tissue-type plasminogen activator (t-PA) which are released from stimulated or damaged endothelial cells. The mean plasma concentrations of thrombomodulin in these disease states were elevated as compared with healthy subjects. A relatively high mean thrombomodulin level was observed in DIC, liver disease, and collagen disease. Abnormally high thrombomodulin values (greater than normal mean value + 3 SD) were found in 32.3% of patients with hematological malignancies, 57.7% of patients with liver disease, 39.3% of patients with diabetes mellitus, 30.0% of patients with collagen disease, 23.1% of patients with thrombotic disease, and 69.0% of patients with DIC. Plasma concentrations of both vWf:Ag and t-PA were also elevated in these patients. On the whole, the plasma thrombomodulin concentration was positively correlated with vWf:Ag (r = 0.441, P less than 0.001) and t-PA (r = 0.398, P less than 0.001). These findings indicate that the elevation of plasma thrombomodulin is frequently seen in a variety of diseases and circulating thrombomodulin is possibly useful for evaluating the endothelial damage in selected disease states.

Biomarkers↗
PubMed1992

Coexistence of congenital afibrinogenemia and protein C deficiency in a patient.

A rare association of congenital afibrinogenemia and hereditary protein C deficiency is described in a 37-year-old female who suffered from ischemic necrosis in the left first toe. The diagnosis of afibrinogenemia was assessed by the absence of fibrinogen in clotting and immunological assays. The diagnosis of hereditary heterozygous type I protein C deficiency was based on the evidence of proportional decreases of activity and antigen of plasma protein C in the propositus, her mother, and two maternal aunts.

Adult↗
PubMed1992

Dietary beta-carotene, cigarette smoking, and lung cancer in men.

A cohort of 5,080 men living in a retirement community in California (United States) and initially free from lung cancer were followed from June 1981 to December 1989. At recruitment, each study participant completed a mailed questionnaire which requested information on the subject's medical history, use of cigarettes, and usual consumption frequencies during the preceding 12 months of 44 vegetable and fruit items. Men who had never smoked had the highest mean daily intake of beta-carotene (8,505 micrograms), followed by past smokers (7,761 micrograms) and then by current smokers (6,178 micrograms). beta-Carotene intake of the subject's wife was correlated significantly with that of the husband in the 4,018 spouse pairs (r = 0.46; P = 0.0001). Among men with similar smoking habits, dietary beta-carotene intake significantly decreased with the spouse's smoking habit: never, past, and current smokers (P = 0.004; test for linear trend). During 31,477 person-years of follow-up, 125 incident cases of lung cancer were observed among the cohort of 5,080 men. Age-adjusted relative risks for lung cancer were below unity (i.e., demonstrating a reduced risk) for higher relative to lower consumption of beta-carotene, of all vegetables and fruits, and of yellow vegetables alone. However, these relative risks approached or crossed the null value when adjusted for personal smoking.

Aged↗
PubMed1992

A simple elimination of clonogenic tumor cells from human bone marrow in vitro by heat: its application to autologous bone marrow transplantation for B-cell lymphoma.

The application of hyperthermia to the treatment of neoplastic disease has focused on solid tumors. Since the hyperthermic sensitivity of human B-cell lymphoma cells is not known, we have examined the effect of hyperthermia on the growth of B-cell lymphoma cell lines (Raji and Daudi) in vitro to evaluate the ability to purge tumor cells from normal bone marrow by heat, utilizing a limiting-dilution assay to measure log depletion of tumor cells in a 20-fold excess of normal bone marrow. When exposed at 42 degrees C and 43 degrees C for 120 min, both clonogenic Raji and Daudi cells were dramatically decreased (a 4- to 6-log reduction) with exposure time, while leaving over half of the normal granulocyte-macrophage progenitor cells surviving at 42 degrees C and 10% at 43 degrees C. This high level of lymphoma-cell depletion by heat correlated with that obtained in immunologic and pharmacologic studies. These results suggest that in vitro hyperthermia might be applied effectively for the elimination of residual lymphoma cells in autologous marrow grafts before autologous bone marrow transplantation in B-cell non-Hodgkin's lymphoma.

Bone Marrow↗