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Biomedical subjects

N Suwa

Publications and source records attributed to N Suwa.

At least 19 recordsLinked to original sources
PubMed1991

The transient appearance of small blastoid cells in the marrow after bone marrow transplantation.

Of 14 patients who underwent allogeneic or syngeneic bone marrow transplantation, 6 had a transient appearance of small blastoid cells in the bone marrow after transplantation. Most of these patients (11) had leukemia, although 3 had severe aplastic anemia. The cells were 8-18 micron in diameter and had scant cytoplasm and dense nuclei with smooth, homogeneous chromatin. They often had distinct nuclear clefts. These cells constituted 4.0-21.3% of the total number of bone marrow cells. They were not reactive with peroxidase, alpha-naphtyl butylate esterase, naphthol AS-D chloroacetate esterase, or periodic acid-Schiff stains. Immunocytochemical analysis revealed that the small blastoid cells expressed terminal deoxynucleotidyl transferase, Ia-like, CD19, and CD10 antigens and cytoplasmic mu heavy chains, indicating a precursor B-cell phenotype. CD20 antigen was not expressed on these cells. The data suggest that cytoplasmic mu may be expressed earlier than CD20 antigen in the differentiation of B-cell lineage. The morphologic, cytochemical, and immunophenotypic characteristics did not distinguish these nonneoplastic cells distinctly from leukemic lymphoblastic cells. The increase of small blastoid cells was a transient and self-limited phenomenon, in contrast to that of neoplastic blasts. These cells should be recognized as a common component of the bone marrow of marrow transplant recipients. The significance and role of these cells in immune recovery and hematopoiesis remain uncertain.

Bone Marrow↗
PubMed1977

Estimation of the distribution of ellipsoids with random test lines.

The distribution F(lambda) of the length lambda of chords delivered by a random test line of unit length, which intersects a sufficiently large number of ellipsoids of different sizes but of uniform shape randomly oriented and dispersed in a three-dimensional space of unit volume, is give by (formula: see text). In this equation, phi(e) is a coefficient determined by two eccentricities of the ellipsoids and N(r) is the distribution function of their major semi-axes r. In the case of spheres phi(e) is 1, but otherwise it is always smaller than 1. N(r) can be further expressed as the product of the probability distribution p(r) of r and the total number Nvo of the ellipsoids in a unit volume. On account of the above equation, it is possible to extend the application of the histometrical methods of spheres with the use of chord length immediately to a group of ellipsoids of uniform shape, so far as the estimation of the parameters of p(r) is concerned. Even with a group of ellipsoids of different shapes, the same principle is valid, provided that all the subgroups of ellipsoids of different eccentricities have a common p(r). Nvo is most practically estimated from Nvo=Tv(h)/2h, in which Tv(h) is the number of tangential points made by ellipsoids with a test plane of unit surface area during its transit h in the direction perpendicular to itself.

Mathematics↗
PubMed1976

Morphometrical method to estimate the parameters of distribution functions assumed for spherical bodies from measurements on a random section.

The general equations to correlate the distribution of the radius r of spheres randomly dispersed in the three-dimensional space with measurements on a random test plane are (see article) and (see article) for the diameter delta of circular sections of spheres; and (see article) and (see article) for the length lambda of chords delivered by intersection of a random test line. In the above expressions Nvo, Nao and Nlambdao are the numbers of spheres in a unit volume, of circles on a unit surface area and of chords per unit length of a test line, respectively; n is O or a positive integer; r the arithmetical mean of r; (deltan) and (lambdan) the means of the n-th powers of delta and lambda, respectively; and Qn a quotient defined by Qn = (rn)/rn. The ratio of measured (delta2/delta2 or (lambda2/lambda2 is used for calculating one of the parameters of assumed theoretical distribution functions. A second parameter is then estimated from delta or lambda. The method was applied to the normal pancreatic islets, and the use of chord length lambda was preferred to that of diameter delta, because the error due to the failure in identifying very small islet sections was minimized in the former.

Biometry↗
PubMed1976

Quantitative analysis of cardiac hypertrophy due to pressure load in reference to the relations of blood pressure, left ventricular weight and left ventricular capacity.

In almost all of the cases of cardiac hypertrophy due to sustained hypertension, left ventricular capacity is increased in proportion to increased left ventricular weight, even in the absence of manifest cardiac insufficiency. The condition is regarded as the general expression of cardiac response to pressure load, and the concept of "isomorphic hypertrophy" is proposed. Concentric hypertrophy of the current concept is observed only on rare special occasions, and its role in cardiac adaptation to pressure load is obscure. The increase in myocardial mass is sufficient to maintain the work done by a unit myocardial volume at a normal level. However, the calculation on pertinent models demonstrates that hypertrophied hearts of any type expel the normal stroke volume with smaller shortening of muscle fibers under larger stress, which is further elevated with the progress of cardiac contraction. Because the maximum force generated by muscle fibers declines with advancing cardiac contraction, hypertrophied hearts harbor a latent risk of mechanical insufficiency. Even under pressure load, ventricular dilation seems to precede the re-inforcement of ventricular wall in the development of cardiac hypertrophy. A common mechanism may be therefore assumed underlying the development and performance of all types of hypertrophied hearts, regardless of the difference in the character of physical loads.

Adult↗
PubMed1976

Errors of parameters of distribution functions for spherical bodies stochastically estimated on a random test plane.

The parameters of some distribution functions for the radius of spherical bodies randomly dispersed in a three-dimensional space can be estimated on a random test plane of unit surface area. In this estimation the set of measured Nao, delta and (delta2) or that of Nlambdao, lambda and (lambda2) is used. They are number of circles, arithmetical mean and secondary moment of circle diameters or number of chords delivered by intersection of a test line of unit length with circles, arithmetical mean and secondary moment of chord length, respectively. Provided that the region of measurement is sufficiently large, intraregional errors of these quantities expressed as the squares of coefficient of variation C are approximately: [C(Nao)]omega2=1/Nao, [C(delta)omega2=(32/3pi2)(Q3/Q2(2))(1/Nao) and [C(delta2)]omega2=(6/5)(Q5/Q3(2))(1/Nao); [C(Nlambdao)]omega2=1/MNlambdao, [C(lambda)]omega2=(9/8)(Q4Q2/Q3(2))(1/MNlambdao) and [C(lambda2)]omega2=(4/3)(Q6Q2/Q4(2))(1/MNlambdao). In these expressions Qn is a quotient defined by (Dn)/Dn, D and n being sphere diameter and a positive integer, respectively. The first three expressions may be used in these forms as the errors for the total region containing spheres. In the second three expressions M is the number of random test lines of unit length. When M is small, they can stand for the errors of the total region. In the case of large M, however, interregional errors or errors of sampling have to be added to them. The geometrical parameter of a distribution function of D is estimated from (delta2)/delta2 or (lambda2)/lambda2. The error of this ratio W is given by: [C(W)]2=[C(X2)-2C(X)]2, where X stands for delta or lambda.

Mathematics↗
PubMed1976

Errors of parameters of distribution functions for spherical bodies stochastically estimated with parallel test lines of regular and narrow intervals.

The parameters of some distribution functions for the radius of spherical bodies randomly dispersed in a three-dimensional space can be estimated with a grating of parallel test lines of regular intervals superposed on a test plane of unit surface area. The interval of the test lines is set narrower than the mean diameter of the circles on the test plane. The errors of number Nlambdao of chords per test line of unit length, arithmetical mean lambda and secondary moment (lambda2) of the length of individual chords are: [C(Nlambdao)*]2=(4/9pi)(Q3/Q2(2))(1/M2lambdaNlambdao)+(4/pi)(lambda/Nlambdao), [C(lambda)*]2=(pi/4)[(32/3pi2) - 1](1/M2lambdaNlambdao)+[(4/pi)-(3pi/8)(Q2(2)/Q3)](lambda/Nlambdao) and [C(lambda2)*]2 = (1024/2025pi)(Q5Q3/Q4(2))(1/M2lambdaNlambdao)+4[(4/pi)-(3pi/8)(Q2(2)/Q3)](lambda/Nlambdao). The first and second terms of the right sides of these expressions represent intraregional and interregional errors, respectively; * denotes the error for the total region; M is the expectation of the number of test lines of unit length covering the test plane; and Qn a quotient (Dn)/Dn of sphere diameter D, n being a positive integer. Intraregional errors are inversely proportional to M2 with the grating, while they are inversely proportional only to M with random test lines. The use of regularly arranged test lines is consequently effective in minimizing intraregional errors.

Mathematics↗
PubMed1976

Left ventricular stiffness and chamber geometry in the pressure-overloaded hypertrophied heart.

Pressure-overloaded hypertrophy of the left ventricle (LV) was produced by coarctation of the ascending aorta in 7 dogs. The overall mean weight of the left ventricle (LVW) was 7.86 +/- 1.49 (S.D.) g/kg body weight; (normal, 5.99 +/- 0.70 g/kg: p less than 0.05). After potassium arrest, pressure-volume (P-V) relationships were examined with the left ventricles isolated from the normals and from the dogs of left ventricular hypertrophy (LVH-dogs). In both groups, the P-V relationships could be expressed by an equation deltaV=a-be-cP throughout the range of filling pressure of 2.5 to 35 cmH2O, where deltav was the actual volume change of LV, P intraventricular pressure, and a, b and c constants. A sensitive index of LV stiffness, the half-inflation pressure (h), was defined as 1n (2b/a)/c. In hypertrophied hearts, h was 10.5 +/- 0.7 cmH2O; (normal 8.0 +/- 0.4 cmH2O; P less than 0.001). The ratio of LVW to LVVp=h (the left ventricular volume at h) in hypertrophy, which was related to the LV chamber geometry, was 3.1 +/- 0.6 in contrast with the normal value of 2.0 +/- 0.3. The development of concentric hypertrophy was thus demonstrated. Moreover, h was closely correlated with LVW/LVVp=h in both the normals and the LVH-dogs (r=0.83; p less than 0.01). On the other hand, an index of LV wall stiffness h/LVW/LVVP=h was relatively constant. Therefore, the increase of LV stiffness in the LVH-dogs was attributed to the change in chamber geometry.

Animals↗
PubMed1975

Two cases of acute pandysautonomia.

Two men had acute nonprogressive pandysautonomia. Both of them showed orthostatic hypotension, fainting in upright position, pupillary disturbances, diminished sweating, anacidity, and impotence. Case 1 showed considerable but inadequate improvement within 31 months. Case 2 recovered completely after 11 months. Clinical and pharmacodynamic investigations suggested that the main lesion was located in postganglionic fibers in case 1 and in preganglionic fibers in case 2. The cause of this disorder is unknown, although both patients had undergone substantial weight loss.

Acetylcholine↗
PubMed1975

Analysis of diastolic pressure-volume relation of the canine left ventricle: half-inflation pressure as an index of left ventricular compliance.

A sensitive index was proposed for the determination of left ventricular compliance. In the isolated potassium-arrested canine left ventricle, the pressure-volume (P-V) relationship was expressed as deltaV=a-be-cP throughout the range of filling pressure from 0 to 40 cmH2O, where deltaV and P were the actual volume change and intraventricular pressure, and a, b and c were constants. Then, half-inflation pressure (h) was calculated from h=[ln(2b/a)]/c. Left ventricular weight (LVW), intraventricular volume (LVV), ventricular external radius (ro) and internal radius (ri) were obtained from the measurements on the left ventricle, fixed at a filling pressure of 10 cmH2O. Then, LVVp=h, ro and ri at h were calculated. In the normal canine hearts, h was well correlated to LVW/LVVp=h and [(ro-ri)/ri]p=h. On the other hand, h/LVW/LVVp=h and h/[(ro-ri)/ri]p=h were constant and independent of LVW within a range of 40 to 150 g. These ratios rose markedly in the state of rigor mortis. From these results, it was concluded that h/LVW/LVVp=h and h/[(ro-ri)/ri]p=h depended on the left ventricular wall stiffness. And h was influenced by changes in LVW/LVVp=h and [(ro-ri)/ri]p=h in the absence of changes in intrinsic muscle stiffness.

Animals↗