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Biomedical subjects

T Hongo

Publications and source records attributed to T Hongo.

At least 127 records · Page 7Linked to original sources
PubMed1985

Spin label study of the effect of ticlopidine on platelets.

The effect of ticlopidine on platelet membrane fluidity was investigated using a spin label technique. Ticlopidine, when orally administered to rats, increased both the order parameter and the motion parameter, indicating a decrease in the membrane fluidity of platelets. On the other hand, the order parameter and the motion parameter decreased markedly when the platelets were aggregated by thrombin. Ticlopidine inhibited the thrombin-induced aggregation of platelets and caused a slight increase in order parameter and motion parameter in thrombin-aggregated platelets. Judging from sodium dodecyl sulfate polyacrylamide gel electrophoresis, ticlopidine did not modify the electrophoretic pattern of platelet proteins appreciably. Ticlopidine decreased cholesterol/phospholipids molar ratio and increased slightly total amounts of proteins of the platelets. These results indicate that the inhibitory action by ticlopidine was accompanied by changes in membrane fluidity, and these changes were due to a perturbation of the membrane phospholipid core of the platelets by ticlopidine and/or its metabolites.

Animals↗
PubMed1985

Interrelationship of some selected nutritional parameters relevant to taste for salt in a group of college-aged women.

Students in a women's college were investigated for taste acuity for salt, discrimination of salt concentrations in food, and anthropometrical (the body mass index, and systolic and diastolic blood pressures) and biochemical nutritional parameters (blood hemoglobin, plasma zinc, plasma copper, plasma vitamin A, plasma retinol-binding protein, urinary sodium, urinary potassium, urinary magnesium, urinary calcium and urinary zinc). Among 95 students who participated in the test for discrimination of salt concentrations, which was repeated 6 times with 5 different test samples, only 43 (45.3%) committed no mistakes. The detection threshold for taste of salt was significantly associated with neither the discriminability of salt concentrations nor any biochemical parameters. Levels of plasma zinc (PZn), urinary zinc (UZn) and plasma vitamin A (VA) were lower in the present subjects than in those reported previously. The rate of correct discrimination (RCD) was significantly correlated with PZn and VA positively, and with urinary sodium (UNa) and urinary potassium (UK) negatively. In the factor analysis to investigate the interrelationship of nutritional parameters, 6 factors with significance were extracted, among which factors 3 and 4 were related to RCD. Factor 3 had large loadings on VA, plasma retinol-binding protein (RBP) and RCD, and factor 4 was positively loaded on UNa and UK and negatively on UZn and RCD. In the stepwise multiple regression analysis (RCD being the dependent variable), significant independent variables selected were VA, UK, PZn, systolic blood pressure and UNa. From these results, the college-aged women's failure in discriminating salt concentrations in food was likely to be related to vitamin A inadequacy, mild Zn deficiency and excessive intakes of Na and K.

Adolescent↗
PubMed1985

[Current problems in the surgical treatment of acquired heart disease].

Despite recent progress in surgical treatment for acquired heart disease, there still remain some problems to be solved. Recently, incidence of the aged and serious cases are increasing. In order to detect the limitation of surgical indication for these cases, a multivariate analysis for prediction of low cardiac output syndrome (LOS) after prosthetic valve replacement was performed. Variables with significant relationship to LOS were different from the types of disease and it seemed difficult to decide indication from single factor such as age or cardiac function alone. Mechanical assist for the postoperative failing heart was carried out for 45 cases. Of these 45, 3 cases underwent clinical application of partial artificial heart (PAH). Two cases weaned from PAH and there was one long-term survival. Duration of cardiac assist in one case who did not wean from PAH was as long as 70 days. Incidence of re-replacement of prosthetic valve due to malfunction was higher in recent 5 years when compared to that in former years. Incidence and type of malfunction of prosthetic valve were different according to the types of prosthesis. Survival and event-free rates in long-term follow-up period were markedly embellished by the types of prosthesis.

Aged↗
PubMed1984

The pattern of monosynaptic Ia-connections to hindlimb motor nuclei in the baboon: a comparison with the cat.

The pattern of Ia-connections to motor nuclei of 17 hindlimb muscles (or groups of muscles) has been investigated in baboons by intracellular recording of Ia-e.ps.p.s evoked in motoneurons from different muscle nerves. The amplitudes are normalized to 70 mV resting potential and compared with similarly normalized Ia-e.ps.p.s in cats. As in the cat, Ia-excitation is drawn from a restricted number of muscles and the homonymous effect is usually dominating. Heteronymous connections to many motor nuclei are different in the two species. For example, hip extensors are generally more Ia-isolated from each other in baboons than in cats, and also knee flexors have fewer Ia-interconnections than in cats. A unidirectional Ia-synergism between some hip extensors and knee flexors in cats has changed to a bidirectional one in baboons, with a tendency to lateralization of the connections. Among ankle extensors, soleus has smaller heteronymous Ia-connections from its synergic ankle extensors than in cats. In baboons, plantaris is heteronymously Ia-excited from gastrocnemius-soleus but not from the intrinsic plantar muscles; whereas in cats there exists a considerable Ia-projection from the intrinsic plantar muscles but not from gastrocnemius-soleus. There is a corresponding difference in the insertion of the plantaris tendon, which shows that this muscle acts as toe extensor in cats but as ankle extensor in baboons. For most of the motor nuclei, the homonymous as well as the total aggregate of Ia-e.ps.p.s is smaller in the baboon than in the cat; but the amplitude range between different motor nuclei is larger in the baboon. Reciprocal Ia-i.ps.p.s are evoked only after spinal transection or when brain function is depressed. It is postulated that baboons, contrary to cats, have descending tonic inhibition of transmission in the reciprocal Ia-inhibitory pathway. The phylogenetic flexibility of Ia-connections is discussed and contrasted with their ontogenetic stability.

Action Potentials↗
PubMed1984

Hair mercury levels of Japanese women during the period 1881 to 1968.

The hair samples of Japanese females during the period from 1881 to 1968 were obtained from various localities of the central area of Japan. Inorganic mercury levels were elevated in unwashed hair samples from prewar periods, especially during 1920s , while elevation of organic mercury levels was conspicuous during 1960s. The increase of inorganic mercury levels in samples from the 1920s is suspected to be due to mercury contamination of hair cosmetics, and increased organic mercury levels in the hair from the 1960s can be explained by active fish consumption.

Adolescent↗
PubMed1984

A physiological study of identification, axonal course and cerebellar projection of spinocerebellar tract cells in the central cervical nucleus of the cat.

Spinocerebellar tract (SCT) neurones in and around the central cervical nucleus (CCN) were physiologically identified by antidromic activation of these cells on stimulation of the cerebellum. Among the spinocerebellar tract cells thus identified, those ascending the contralateral spinal funiculi were found in the CCN and ventralwards, whereas those ascending the ipsilateral funiculi existed mostly dorsal to the CCN partly overlapping with crossed cells in the nucleus. Mapping sites from which CCN cells were antidromically activated showed that axons of the CCN-SCT cross at the same segment, ascend the ventral funiculus initially, the lateral funiculus at rostral C1 and the lateral border of the medulla to reach the cerebellar peduncle, enter the cerebellum mainly via the restiform body but possibly also via the superior peduncle. Systematic mapping of stimulation within the cerebellum indicated that the CCN-SCT projects to the medial part of the anterior lobe and the posterior lobe bilaterally. Projection to lobules I-II was found in almost all CCN-SCT cells examined. Three fourths of CCN-SCT cells projected to the posterior lobe, as revealed by less extensive mapping. Mapping of axonal regions of the same single CCN-SCT cells showed that they project multifocally in the cerebellum, where projection to lobules I-II was common and that to other areas varied with individual cells. Conduction velocities decreased within the cerebellum probably as the result of repeated branching. Mossy fibre responses evoked on stimulation of the C2 dorsal root in cats with the transected dorsal funiculi were shown to be mediated mostly via the CCN-SCT. Mapping the field potential showed that the response was by far the largest in lobules I-II. This suggested that the terminals provided by the CCN-SCT are the densest in these lobules.

Afferent Pathways↗
PubMed1984

Neck muscle afferent input to spinocerebellar tract cells of the central cervical nucleus in the cat.

Extracellular and intracellular recordings were made from spinocerebellar tract neurones of the central cervical nucleus (CCN) in C1-C3 segments of the anaesthetized cat. These neurones were identified by antidromic activation from the cerebellar peduncle. Stimulation of the ipsilateral dorsal root elicited extracellular spikes or EPSPs with a monosynaptic latency in almost all CCN neurones in the same segment (segmental input). Late excitatory effects were also observed in about one third of CCN neurones. The monosynaptic EPSP was occasionally followed by an IPSP. The excitatory input from the dorsal root to CCN neurones was extended over several segments for some CCN neurons (extrasegmental input). Monosynaptic excitation was evoked in CCN neurones after stimulation of dorsal neck muscle nerves as well; i.e. splenius (SPL), biventer cervicis and complexus (BCC), rectus capitus dorsalis, and obliquus capitus caudalis. Thresholds for this excitation were near the threshold of the nerve, suggesting that it originated from group I fibres. The component of excitation added after strong stimulation of neck muscle nerves would be attributed to group II fibres. When a CCN neurone received excitatory input from the nerve of one muscle, it was generally not affected by stimulation of other nerves in the same segment. Such muscle specificity of segmental input was the principal pattern of connexion of neck muscle afferents with CCN neurones. In some cases, however, excitatory convergence from SPL and BCC nerves onto single CCN neurones or excitation from the SPL nerve and inhibition from the BCC nerve were also observed. Nearly half of the CCN neurones received input from one muscle nerve of the same segment and not from the afferent of the same muscle of different segments, indicating a segment specificity of input. In the remaining CCN neurones, weaker excitatory effects were induced from afferents of different segments as well. In such extrasegmental effects, inputs to CCN neurones from caudal segments predominated in frequency over those from rostral segments. The origin of extrasegmental input was generally confined to the same muscle. Low threshold muscle afferents from the SPL and BCC were intraaxonally stained with HRP. The collaterals of the stained fibre distributed branchlets and terminals to the CCN, laminae VII, VIII, and motor nuclei. Two fibres responding to local muscle prodding or stretch showed a similar morphology. The findings indicated that muscle spindle afferents from primary endings projected to the CCN.

Afferent Pathways↗
PubMed1984

Elemental contamination of Japanese women's hair from historical samples.

Japanese women's hair, which had been cut in the past and preserved was examined for the presence of 12 elements (Na, K, Mg, Ca, Sr, Mn, Fe, Cu, Zn, Hg, Pb and P). Elevated levels of Fe, Mn, Cu, Pb and Hg (inorganic mercury) were conspicuous in the samples cut in the period 1880-1929 and used as hair pieces (kamoji). The effects of washing on element concentration depended on both the method of washing and the type of element. The least effective was washing with acetone and water, compared with two other methods involving anionic or non-ionic surface active agents. The most resistant elements to washing were Pb, Hg, Cu and Zn. From the intercorrelation of element content and factor analysis, by examining the diminution of contents by washing and by comparing the detected levels with the values measured on contemporary Japanese women's hair, the contribution of exogenous contamination to hair levels was found to be very strong for Fe, Mn, Cu, Hg (inorganic mercury), and Pb, moderate for Na and Zn, and negligible for Ca, Mg, Sr, K, Hg (organic mercury), and P.

Calcium↗
PubMed1984

Toxic effects of selenodiglutathione on pregnant mice.

A single dose of selenodiglutathione (GSSeSG) or sodium selenite (SS) was injected i.v. into pregnant CD-1 mice on day 12 of gestation at dosages varying from 16.4-32.0 mumol/kg body weight. Dose-dependent elevation of maternal death rates was observed for both treatments, and the slope of the dose-response curve was significantly steeper following GSSeSG treatment. However, fetotoxic effects were not different between the treatments.

Animals↗
PubMed1984

The capacity of antigen-presenting cells is fully preserved in childhood cancer patients.

T cells from 19 out of 25 childhood cancer patients showed impaired proliferative responses to purified protein derivatives (PPD)-pulsed antigen-presenting cells (APC) although all of the patients had been immunized with BCG. To test whether such low responsiveness of T cells results from the dysfunction of T cells or from that of APC, the experiment was designed to assess the proliferative response of T cells from patients or their parents to PPD-pulsed APC from patients or parents. These combinations seem to be suitable to assess the activity of T cells or APC since at least partial identity of HLA-D/DR antigens is required for T cell-APC interactions. Although T cells from patients who showed low responsiveness to PPD failed to respond even to PPD-pulsed APC from parents, T cells from parents were able to respond to PPD-pulsed APC from patients as well as to autologous APC. These observations strongly suggest that the low responsiveness to PPD in childhood cancer patients results from the dysfunction of T cells, and the capacity of APC is fully preserved. In other words, it appears that the capacity of APC is not impaired by chemotherapy, neoplastic cells, or other factors. Suppressor T cells appeared not to be involved in such dysfunction of T cells.

Adolescent↗
PubMed1984

[Primary malignant melanoma of the breast].

A 30-year-old woman with malignant melanoma of the breast is reported. She palpated a tumor in the upper outer quadrant of the left breast. Physical examination and mammographic findings suggested a benign tumor and excisional biopsy was performed. A cut surface of the tumor showed a few black spotty lesions. Pathologic examination revealed infiltration of melanoma cells around the mammary glands and ducts and the connective tissue. Melanoma cells were present in the mammary ducts, suggesting that these cells originated from the ductal epithelium.

Adult↗
PubMed1983

Spontaneous formation of a monolayer membrane from sarcoplasmic reticulum at an air-water interface.

Surface pressure was found to be produced spontaneously at the interface between air and a suspension containing fragmented sarcoplasmic reticulum (FSR) from rabbit white muscle. Large and stable surface pressure was formed only in a limited concentration range of FSR in the suspension and the pressure formation was proved to be an irreversible phenomenon, suggesting the formation of a monolayer membrane resulting from the disruption of FSR vesicles. Monolayer formation was directly confirmed by analyzing the components included in the membrane and by calculating the surface area occupied by these components. The monolayer included phospholipids, cholesterol and proteins, and appeared to originate from FSR vesicles since the molecular ratios of these components as well as the results of the SDS polyacrylamide gel electrophoresis were similar in both membranes. This phenomenon can be utilized as a method of monolayer preparation from biological membrane vesicles, and should be very useful for the reconstitution of planar biological membranes.

Air↗