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Biomedical subjects

H Kanai

Publications and source records attributed to H Kanai.

At least 145 records · Page 8Linked to original sources
PubMed1990

Hypertension in obese children: fasting serum insulin levels are closely correlated with blood pressure.

The relationship between blood pressure and anthropometric or metabolic factors was studied in 324 obese children aged 9.5 +/- 1.8 years (mean +/- standard deviation). Obese children had a significantly higher blood pressure than non-obese children (systolic blood pressure: 121 +/- 14 mmHg in obese children vs 112 +/- 11 mmHg in non-obese children, P less than 0.001; diastolic blood pressure: 72 +/- 9 mmHg in obese children vs 66 +/- 7 mmHg in non-obese children, P less than 0.001). When the obese children were divided into hypertensive and normotensive groups, there was a significant difference in fasting serum insulin levels between the two groups (19.3 +/- 9.3 microU/ml in the hypertensive group vs 13.0 +/- 6.1 microU/ml in the normotensive group), and a close correlation between fasting serum insulin levels and systolic blood pressure was demonstrated (r = 0.63, P less than 0.001). However, there was no significant correlation between blood pressure and the degree of obesity itself or the waist-to-hip ratio in the obese children. There was no significant correlation between blood pressure and fasting plasma glucose, serum total cholesterol, or triglycerides levels in the obese children. Moreover, the correlation between fasting insulin levels and blood pressure was shown to be independent of the degree of obesity or waist-to-hip ratio and age by multiple regression analysis. These results indicate that hyperinsulinemia itself may play an important role in the pathogenesis of hypertension in obese children.

Anthropometry↗
PubMed1990

[Iron-dependent cytotoxic effects of dopa on cultured neurons of the dorsal root ganglia].

Although many authors have suggested that dopamine and its metabolites producing free radicals have an harmful effect in the substantia nigra, experimental evidence has not been shown. Using a newly established enzyme immunoassay of the neurofilament protein, a reliable index for the number of survived neurons in tissue culture, we evaluate the effects of Dopa on the neurons of dorsal root ganglia from mice. Neurons were destroyed by the exposure of 0.5 mM Dopa with or without superoxide dismutase and catalase, but they were saved by the pretreatment with 1.0 mM deferoxamine mesylate, a powerful iron-chelating agent. Formation of malondialdehyde, an index of lipid peroxidation, was also observed in the reaction of 0.5 mM Dopa and cerebral cortical neurons from new-born rats only when iron was present. These results indicate that Dopa initiates lipid peroxidation of cell membrane in the presence of a small amount of iron in the culture with little or no participation of reactive oxygen species, leading to the destruction of the neurons. In Parkinson's disease, the cytotoxic mechanism of Dopa and iron may involve the neuronal degeneration in the substantia nigra abundant in iron and dopaminergic neurons.

Animals↗
PubMed1989

[Effects of nerve growth factor and gangliosides on neurite elongation of cultured nerve cells from senescent mouse].

In vivo studies of nerve tissue of senescent animals have raised the possibility that initiation and elongation of axonal processes in regeneration are somehow altered by aging. However, this has not been examined in dissociated cell culture because of technical difficulties. The present study was performed to compare the effects of nerve growth factor (NGF) and gangliosides mixture (Gg1) on neurite elongation of dorsal root ganglion (DRG) cells from senescent mice with those from young adult mice. DRG neurons were obtained from male mice of the 72-week-old (Group O) and of the 10-week-old (Group Y). Dissociated neuronal cells of each group were cultured for 4 days in chemically determined serum-free medium including various levels of 7S-NGF up to 160 ng/ml or of Gg1 up to 20 micrograms/ml. After immunohistochemical identification of neuronal cells, neurites with two kinds of lengths, maximum length (ML; length of the longest neurite belonging to the individual neuron) and total length (TL; summation of length of all neurites belonging to that) were quantified as elongated neurites. NGF showed concentration-dependent neurite elongation in ML and TL of Group O and Y. Gg1 increased TL at relatively low levels in both groups but no significant changes were detected in ML. On the other hand high levels of Gg1 did not show any enhancement in ML or in TL. These results indicate that the effects of NGF and Gg1 were not altered by aging, as far as elongation of neurite was concerned. In addition to biochemical deterioration of the neuron itself, decreased release of neurite-promoting factors such as NGF and Gg1 from target cells of the neuron and surrounding cell may account for the reduction of capacity for neurite regeneration in aged animals.

Aging↗
PubMed1989

Intraplatelet and urinary serotonin concentrations in systemic lupus erythematosus with reference to its clinical manifestations.

Intraplatelet and plasma serotonin (5-HT) levels were measured in 39 patients with systemic lupus erythematosus (SLE) and in 15 healthy subjects. Urinary 5-HT concentrations were also measured in 32 patients with SLE and 14 healthy subjects. A significantly lower intraplatelet 5-HT level was observed in SLE patients, especially in the active phase with hypocomplementemia (CH50 less than 30 U/ml), 0.17 +/- 0.09 pmol/10(5) platelets, than that in normal controls, 0.36 +/- 0.14 pmol/10(5) platelets (p less than 0.01). Active SLE showed a significantly higher urinary 5-HT concentration, 0.37 +/- 0.15 nmol/ml/mg Cr, than normal controls, 0.21 +/- 0.08 nmol/ml/mg Cr (p less than 0.01). Serial measurements of intraplatelet and urinary 5-HT levels in five patients with SLE revealed a significant correlation between clinical activity and intraplatelet and urinary 5-HT levels. Exogenous 5-HT uptake by platelets in vitro is not altered in patients with SLE. The mechanism of decrease of intraplatelet 5-HT and increase of urinary 5-HT in SLE may be explained by the continuous activation of the blood coagulation within the vessel.

Adolescent↗
PubMed1989

[Hemodynamic significance of diffuse lung uptake of 201Tl in heart diseases].

Clinical significance of diffuse lung uptake of 201Tl was studied in 244 cases of various heart diseases. The grade of lung uptake of 201Tl was assessed by total lung uptake ratio (L/T), maximal lung uptake ratio (Max/T), lung to myocardium or mediastinum counts ratio (M/H or M/Med) and visual grade. L/T, Max/T, M/H and M/Med were directly correlated with pulmonary arterial pressure (PCW), and inversely correlated with cardiac output (CO) and cardiac index (CI). Among them, L/T was the best index to assess PCW, that was correlated with PCW (r = 0.65), CO (r = -0.53) and CI (r = -0.45). The visual grade of 201Tl lung uptake was correlated with L/T, and the increased lung uptake was associated with a higher PCW and a lower CO as well as a lower CI. Diffuse increased lung uptake of 201Tl was observed in 29 of 41 cases (70.7%) with myocardial infarction, 25 of 29 cases (86.2%) with mitral valvular diseases and 9 of 10 cases (90.0%) with combined valvular diseases, in addition, in most cases with left heart failure and cases of NYHA 3 and 4, but that was not rarely observed in cases of NYHA 2 and without left heart failure. In heart diseases, 201Tl myocardial scintigraphy seems to be valuable for detection of left heart failure including pulmonary congestion and interstitial pulmonary edema. Total lung uptake ratio (L/T) may be useful for estimation of PCW, and the visual grade of 201Tl lung uptake may be applicable as routine index for grading of lung uptake of 201Tl.

Aged↗
PubMed1989

[Clinical and etiological study of crossed cerebellar diaschisis. Report of two cases].

With the great progress in the imaging technique of cerebro-cerebellar perfusion and metabolism, it has been revealed that supratentorial cerebrovascular disorders often cause some reduction of contralateral cerebellar blood flow and metabolism. The phenomenon, termed crossed cerebellar diaschisis (CCD), is interpreted to be brought about by transneuronal deactivation of cerebellum via the corticopontocerebellar pathway and usually not to accompanied by limb-incoordination. We have experienced 2 cases presenting ataxia clinically and CCD in positron emission tomography (PET) which are thought to be caused by the interruption of two distinctive neural pathways, the corticopontocerebellar and cerebellorubrothalamic pathways. Case 1 was a 34-year-old housewife with cerebral infarction which magnetic resonance imaging disclosed in the left parietal cortex and subcortical white matter. She showed mild right-sided hemiataxia featured by dysarthria, hypermetria, dysrhythmia, decomposition, dysdiadochokinesis and rebound phenomenon. Cheirooral syndrome, a hand-pronation sign and defects of combined sensation were present on the right but not accompanied by any disturbances of deep sensation. PET with 15O-labeled CO2 and O2 demonstrated the left frontoparietooccipital and contralateral cerebellar hypoperfusion and hypometabolism. Case 2 was a 69-year-old female suffering from aftereffects of old thalamic hemorrhage. Neurological examination revealed moderate degree of right-sided hemiataxia suggesting a cerebellar type of dysfunction like in case 1. Muscle power and sensory system were well-preserved. Brain CT revealed a small and restricted low density area in the left posterolateral thalamus indicating destruction of the Vim nucleus. PET study confirmed reduced blood flow and oxygen metabolism in the left thalamus and contralateral cerebellar hemisphere.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Evaluation of 99mTc-albumin distribution ratio in the cardiac chambers and lungs].

In order to assess blood volume of the cardiac chambers and lungs, distribution ratio of 99mTc-albumin (HSA) was obtained from radionuclide angiocardiogram and non-gated or gated equilibrium cardiac pool scintigram, using a scintillation camera coupled to a minicomputer. The radio-activity of 99mTc of the entire cardiac blood pool including the large vessels (T), the right ventricle including the right atrium (RV) and the left ventricle (LV) was calculated from the 30 degrees anterior oblique cardiac pool scintigram. That of the both lungs (Lu) was calculated from the anterior cardiac pool scintigram. The radioactivity of total injected dose of HSA (H) was estimated from the initial transit of the tracer obtained by the radionuclide angiocardiogram. Then, distribution ratio of HSA of the each region of interest was expressed as RV/H, LV/H, T/H and Lu/H. RV/H, LV/H and T/H were 3.4 +/- 0.6%, 3.1 +/- 0.5% and 10.4 +/- 2.0% in controls, 6.0 +/- 0.8%, 2.6 +/- 0.8% and 14.2 +/- 2.4% in cor pulmonale, and 7.9 +/- 1.7%, 7.7 +/- 3.5% and 20.7 +/- 4.3% in heart diseases with left heart failure, respectively. Lu/H was 4.9 +/- 1.4% in controls, 4.4 +/- 1.1% in cor pulmonale and 6.6 +/- 1.9% in heart diseases without left heart failure. LV/H was correlated with left ventricular end-diastolic volume by contrast ventriculography. LV/H and RV/H were related with functional classification of NYHA. In conclusion, these parameters may be utilized as indices of the volume of blood pool of the heart chambers and lungs, and this method seems to be clinically applicable for the evaluation of pathophysiology in heart diseases.

Adult↗
PubMed1989

Evaluation of leg edema using a multifrequency impedance meter in patients with lymphatic obstruction.

To evaluate quantitatively local edema, electrical tissue impedance in the leg was measured with a multifrequency impedance meter in 10 patients without edema and in 10 other patients with lymphedema after hysterectomy for uterine cervical cancer (Groups 1 and 2, respectively). Equivalent resistivity of extra- and intracellular fluid (RE, RI, respectively) and the ratio RI/RE were calculated. The difference in mean RE between Groups 1 and 2 was significant (p less than 0.05). In four patients in Group 1 and nine in Group 2, simultaneous measurements were carried out on both legs. The differences between mean RE and RI/RE in Group 2 were significant (p less than 0.05, p less than 0.025, respectively). In these 13 patients, correlation coefficients between the ratio of cross-sectional areas of both legs, and both RE and RI/RE were -0.614 (p less than 0.05) and 0.805 (p less than 0.001), respectively. The results suggest that RE and RI/RE could be used as sensitive indicators of local edema.

Adult↗
PubMed1988

A novel system of LDL apheresis combining a centrifugal plasma separator with a specific LDL adsorption column.

A novel system of low density lipoprotein (LDL) apheresis for familial hypercholesterolemia (FH) was developed, combining a centrifugal plasma separator (IBM-2997) with a new adsorption column specific to lipoproteins containing apolipoprotein B (apo-B), and its operation was compared to previous methods. The present system selectively removed LDL without the substantial reduction of high density lipoprotein that was seen with other methods using membrane filters. The capacity for LDL removal was slightly more reduced with the adsorption column than with the membrane filters when a single column was used. Since the ability to obtain plasma in the centrifugal system was much higher than in the system using membrane filters for plasma separation, efficient apheresis could be performed in a much shorter time, without making an arterio-venous shunt. Remixing of blood cells, such as platelets, with the separated plasma sometimes raises the pressure within the plasma component separator, but the problem could be avoided by withdrawing the buffy coat fraction, using the WBC pump of the IBM separator. In conclusion, the novel system, combining the centrifugal plasma separator with the adsorption column, has proved, in our hands, to be a more useful and more convenient method than those previously used for the treatment of severe FH.

Adsorption↗
PubMed1988

Physical properties of flowing blood.

The changes of viscosity, optical reflection and electrical resistivity of blood due to flow are dependent on the orientation and deformation of red cells. From electrical point of view, it can be assumed that blood is suspension of small insulating particles (red cells) in conductive fluid (plasma) when the frequency of supplied voltage is lower than several hundreds KHz. When blood flows, red cells deform and orient in flow direction. Therefore, flowing blood shows anisotropic electrical and optical properties. In steady flow, blood resistivity longitudinal to flow decrease with flow rate, and transverse one increases. Blood flow in living body is not steady but pulsatile. We measured both longitudinal and transverse resistivity changes, optical reflection change and viscosity change of sinusoidally flowing blood in a rectangular conduit. The results are 1) during one period of sinusoidal flow the longitudinal resistivity change is opposite to that of transverse one, 2) the waveform of reflection light change is similar to that of resistance change, and 3) minimum points of both longitudinal resistivity and viscosity changes do not appear at the moment when flow is zero but are delayed. When the amplitude of sinusoidal flow is small and oscillation frequency is high, the phase difference between the zero crossing period of flow and the period of minimum change in resistivity, increases up to 90 degrees. Viscosity of blood decreases with increase of amplitude and frequency of sinusoidal flow.

Animals↗
PubMed1988

[Estimation of regional pulmonary ventilation using perfusion lung scintigram].

Using perfusion lung scintigram, motion of the regional pulmonary area and lung edge during ventilation was analyzed in 30 patients with various respiratory diseases. Images at maximal inspiration (I) and expiration (E) were obtained after the intravenous injection of 99mTc macroaggregated albumin (222-370 MBq) using a scintillation camera coupling to a small digital computer. Radioactivity in each pixels (E and I) and number of pixels in the both lungs (AE and AI) were calculated from the image of E and I. Changes of the regional pulmonary radioactivity during ventilation were calculated according to an expression as (E-I)/I, and the image of (E-I)/I was obtained too. The image of (E-I)/I consisted of positive and negative components. The image of positive (E-I)/I visualized the motion of the regional pulmonary area, and sum of positive (E-I)/I in the both lungs was correlated with vital capacity (r = 0.83, p less than 0.001). The image of negative (E-I)/I superimposed with the edges of the lung at maximal inspiration and expiration revealed the limits of the motion of the lung edge during ventilation. These results suggest that this technique is useful to estimate the regional pulmonary ventilation and motion of the lung edge.

Humans↗