EPR identification of the negatively charged vacancy in diamond.
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Biomedical subjects
Publications and source records attributed to H Kanda.
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Deoxyspergualin (DSG), which is a new immunosuppressive drug developed in Japan, is expected to be an immunosuppressant for the treatment of rejection, because it has immunosuppressive action different from that of other drugs. In the present study we used DSG to treat renal allograft rejection of in total 17 cases; 6 cases with acute rejection, 8 with chronic rejection and 3 with acute on chronic rejection. We infused DSG very slowly over 3 hours at a dose of 3-7 mg/kg/day for 5-7 days. Four cases (44.4%) with acute or acute on chronic rejection showed excellent response to DSG, three cases (33.3%) showed fair response and two cases (22.3%) did not respond at all. We also used DSG in patients with chronic rejection. In many of them, the increase in serum creatinine was suppressed. Ten of the total patients (58.8%) developed side effects including leukocytopenia, thrombocytopenia, numbness of the fact etc. No patients needed discontinuation of DSG. From the above results, we think that DSG is a safe and effective drug to treat acute rejection. Furthermore, we could get the results which suggest that DSG is effective for the treatment of chronic rejection.
Distribution of intermediate filament proteins (IFs) and several special markers was studied in 39 testicular germ cell tumors and 8 embryos and foetuses. The similarity and difference between development of germ cell tumor and embryogenesis were immunohistochemically investigated. Seminoma and embryonal carcinoma, as tumoral counterparts of undifferentiated germ cells, were characterized by little IF expression. This study revealed that the maturing and differentiating process in germ cell tumor is different from normal embryonal development and the tumor cells showed leaping maturing steps in tumorigenesis. Immunostaining for IFs helped to discover the further differentiation occurring in embryonal carcinoma and to demonstrate heterogeneous elements in non-seminoma germ cell tumors, which sometimes might not be apparent by light microscopical observation of H&E staining section. According to the findings, two patterns in mixed germ cell tumors are suggested; i.e., combined and diffuse types. The mechanism of tumorigenesis of the two types is supposed to be different. Clinically, the prognosis of most patients with testicular germ cell tumor is fairly good because of the improved chemotherapies that are dependent on histological diagnosis.
The diagnostic value of preoperative echocardiography was assessed in 51 patients with aortic stenosis. We measured 1) left ventricular-aortic pressure gradient (LV-Ao PG), 2) aortic valve area (AVA), 3) grade of LV hypertrophy and function, and 4) aortic annulus diameter for determining the availability and size of a prosthesis. The maximal instantaneous PG (max-PG) by continuous-wave (cw) Doppler echocardiography correlated well with the peak-to-peak PG by cardiac catheterization (cath), and their correlation equation was y = 1.49 x -48.3 with a correlation coefficient of 0.90. Excellent correlations were also found between cw-max PG and cath-max PG (r = 0.84), and between cw-mean systolic PG and cath-mean systolic PG (r = 0.80). The AVA of the echocardiogram, which was derived from the stroke volume using Gibson's M-mode echocardiographic formula and the cw-Doppler echocardiographic mean gradient, correlated well with the AVA of the cardiac catheterization using Gorlin's formula (y = 1.33 x -0.61, r = 0.79). Preoperative LV pump function, which was obtained from the M-mode echocardiogram, correlated inversely with end-systolic wall stress, and a depressed LV pump function was observed in patients with inadequate hypertrophy. In such patients, however, depressed function was alleviated after surgical treatment. Thus, we considered that cardiac catheterization for further examination is unnecessary, even in such patients. To determine the available size of the prosthesis, measurement of the inner diameter of the aortic annulus on the long-axis cross-sections was the most useful.(ABSTRACT TRUNCATED AT 250 WORDS)
To determine the relative superiority of a prosthesis in the mitral position, in vivo hemodynamics were examined by Doppler echocardiography, and the results were compared with other types of mechanical mitral valves including 63 Björk-Shiley convexo-concave (BS) values, 30 Duromedics (DM) valves, and 58 Medtronic Hall (MH) valves. For this comparison, the following indices were evaluated: peak velocity of mitral flow (PV), mitral valve orifice area (MVA), mitral valvular regurgitation, New York Heart Association (NYHA) classification, pulmonary capillary wedge pressure (PC), cardiac index (CI) and valve-related complications. On Doppler echocardiograms, PV ranged from 1.2 to 2.0 m/sec with a mean of 1.6 m/sec. There was no evident relationship between the PV and the valve size in each type of prosthesis, and no significant difference in the PVs among the valves. The mean MVA was 2.6 cm2 (25 mm DM, 25 mm MH), which was regarded satisfactory from a clinical standpoint. MVA increased with the increase in the valve size in all types of valves, and of all sizes, MVA was larger in the DM and MH groups than in the BS group. Similarly, the incidence of valvular regurgitation was relatively low in all groups, and the degree of regurgitation proved to be grade II or less in all cases. As for the clinical results, clinical symptoms (NYHA) and hemodynamic states (PC, CI) improved postoperatively, with the differences among the types of prosthetic valves being insignificant. The incidences of thromboembolism, valvular thrombosis, valve failure and prosthetic endocarditis were relatively low in all groups.(ABSTRACT TRUNCATED AT 250 WORDS)
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The value of dynamic magnetic resonance imaging (MRI) in the examination of the function of transplanted kidneys was examined. Dynamic MRI was performed on 14 renal transplant patients. After the injection of Gd-DTPA (dimeglumine gadopentetate), we used small tip angle gradient echo (STAGE) technique with a flip angle of 20 degrees. The cortex was higher in signal intensity of well functioning grafts than the medulla before the injection in Gd-DTPA. Signal intensity of the cortex decreased after 30 seconds. After 1 minute the signal intensity of the cortex recovered and low intensity band meaning passage of Gd-DTPA at corticomedullary differentiation was displayed. Signal intensity of the medulla decreased after 3 minutes. Signal intensity of the parenchyma of transplanted kidney after 5 minutes was much the same as that before injection. Image of poor functioning grafts displayed unclear figures. Time-intensity values of both cortex and medulla in well functioning grafts decreased rapidly after about 2 minutes, and rose thereafter. Time-intensity curves of both cortex and medulla were almost flat on and after 5 minutes. Time-intensity curves of both cortex and medulla in poor functioning grafts were almost flat through out the examination. We concluded that effective parameters of the graft function for the time-intensity curve were delta I1 and delta I2. Dynamic MRI was suggested to be useful in the evaluation of kidney graft function.
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The Drosophila melanogaster transposable element copia is usually 5 kb long with long terminal repeats (LTRs), and its major transcripts are a full-length 5-kb RNA and a 2-kb RNA. We have previously shown that the 2-kb RNA is generated through splicing. Here, we have cloned a genomic intronless copia using an oligodeoxyribonucleotide probe which is specific for the junction of the two exons. The unusual copia is bounded by two LTRs and lacks precisely the intron of the 2-kb copia RNA. Identification of genomic intronless copia strongly suggests that copia transposes through an RNA intermediate. Moreover, we have found that copia virus-like particles (VLPs), in which reverse transcription of copia RNA seems likely to occur, packages the spliced copia RNA much less efficiently than the full-length copia RNA. This result leads to the suggestion that much lower copy number of genomic intronless copia, as compared with that of 'normal' copia, may be responsible for the inefficient packaging of the spliced copia RNA into the VLP.
Drosophila copia protease is likely to be encoded in the gag gene. We have expressed copia gag polyprotein precursor in E. coli. The gag precursor was correctly processed to generate a unique laminate structure in E. coli. The processing was almost completely blocked by a mutation at the putative active site of copia protease, and resulted in accumulation of the precursor. Furthermore, the laminate structure was not found in E. coli expressing the mutant precursor. These results indicate that the protease is involved in cleaving the gag precursor itself. Also, the assembly of copia gag protein should correlate to the autoprocessing of copia gag polyprotein precursor.
Many investigators have reported that myocardial norepinephrine content is decreased in congestive heart failure. However there have been no studies of how decrease in myocardial norepinephrine might influence myocardial contraction. To clarify whether decreased myocardial norepinephrine per se affects myocardial contraction, we observed the change in left ventricular contractility during 30 min of left stellate ganglion stimulation in control and acutely reserpinized dogs. We obtained left ventricular max dp/dt and left ventricular end-systolic pressure-segment length relationships as indicators of left ventricular contractility. Both parameters decreased after left stellate ganglion stimulation in reserpinized dogs (left ventricular max dp/dt: 2064 +/- 200 to 1608 +/- 168 mmHg/s, left ventricular end-systolic pressure-segment length slope 117 +/- 22 to 79 +/- 14 mmHg/mm, n = 8, P less than 0.05), while they did not change in controls. In reserpinized dogs, left ventricular norepinephrine content decreased to one-third that of controls before the stimulation, and further decreased after stimulation. These data indicate that lowered myocardial norepinephrine itself may be responsible for the negative effect on left ventricular contractility in congestive heart failure.
The C3H/HeN (C3H) and C57BL/6N (C57) mouse strains are known, respectively, for their high and low susceptibility to both spontaneous and chemically induced hepatocarcinogenesis. The present study was aimed at elucidating whether this difference is dependent on intrinsic features of the target hepatocytes or in the in vivo milieu and associated growth promoting factors to which the cells are exposed. C3H in equilibrium with C57 chimeric mice were produced and given injections of diethylnitrosamine (20 microgram/g body weight) at the age of 15 days. The animals were sacrificed 6 or 9 months thereafter, and the numbers and sizes of altered cell lesions were scored. The clonal growth of both cell types was immunohistochemically confirmed using anti C3H-specific antigen antibodies. Quantitative assessment revealed C3H lesions in the chimera livers to be far larger (5:1) than those of C57 derivation and associated with more frequent malignant progression as was evident histologically. Furthermore, foamy change and hyalin body formation, which have been described as characteristics of C3H and C57BL hepatic tumors, respectively, were also featured as differentiative characteristics in lesions of both cell types in chimera mice. Thus, the results clearly demonstrated that the principal mechanism(s) underlying strain difference in diethylnitrosamine-initiated hepatocarcinogenesis exists in the target cells and is not milieu-dependent.
The complete nucleotide sequences of the variable region genes of the heavy and light polypeptide chains of a human monoclonal rheumatoid factor (RF) produced from a human-mouse heterohybridoma were determined. The antibody, designated YES8c, contained V kappa III, J kappa 2, VH1, JH4, and a D gene segment of 9 amino acids. The nucleotide sequences and the deduced amino acid sequences of the light chain variable region were remarkably homologous (97-98%) to previously described RF of the Wa idiotypic family (PAY, GLO, CUR, FLO, and GAR) and to that of a V kappa III germline gene (Humkv325). The YES8c heavy chain variable region gene was most closely related to the VH1 gene of the restricted human fetal repertoire, designated 51p1, and also to 3 rearranged VH1 genes that were recently isolated from patients with chronic lymphocytic leukemia. These results suggest that variable region genes of RFs are highly conserved and that YES8c VH, as well as V kappa, may be identical to heavy and light chains expressed during early B cell development.
To determine whether chronotropic and atrial inotropic responses to sympathetic nerve stimulation are maintained longer than ventricular inotropic response, the present study was performed with control and acute reserpinized dogs. We stimulated the right stellate ganglion of both groups supramaximally for 60 min and compared right atrial responses (chronotropism and inotropism) with left ventricular (LV) dP/dtmax. In the control group, heart rate (HR) immediately increased and was only slightly attenuated with 60 min of stimulation, and right atrial (RA) inotropic response was less attenuated than was LV response (7% in HR, 33% in RA dP/dtmax, 50% in LV dP/dtmax, P less than 0.01, from the peak value of each response). RA and LV norepinephrine (NE) content was decreased by the stimulation but remained higher than the LV control value. In the reserpinized group, NE content in the RA was low before the stimulation and was further decreased by the stimulation. In this group, HR response was attenuated (27% in HR, P less than 0.01) as was LV dP/dtmax, and the difference in contractile responsiveness between atrium and ventricle disappeared (58% in RA dP/dtmax vs. 61% in LV dP/dtmax, NS). The results indicate that the chronotropic response was only slightly attenuated and that the atrial contractile response was attenuated less than the ventricular response, with sustained sympathetic nerve stimulation in the normal heart. This can be ascribed to the much higher NE content in the RA than that in the LV.
We reviewed our 12.5-year experience with ileocecal conduit (ICC) and report the long-term results of 147 cases of ICC compared with those of our 102 cases of ileal conduit (IC). We usually performed ICC following total cystectomy for carcinoma of the bladder, while we chose IC in cases of high stage or recurrent malignancies. The average follow-up period was 41.7 months in the ICC group and 28.8 months in the IC group. The postoperative mortality (6.1%) and the incidence of early complications (21.1%) in the ICC group were comparable with the reported incidences for IC. In the later period, stomal problems were most frequently encountered. Urinary tract complications are important because they affect renal function in the course of a long period of time. Excretory urogram showed a satisfactory result and serum creatinine remained within the normal limits even in patients followed up for a long time in both groups. The incidences of pyelonephritis and urinary stones in the ICC group were 13.6 and 5.4%, respectively. We had expected a much lower incidence of these complications and ICC could not cover all the drawbacks of IC. However, at present, there is no ideal or perfect method of urinary diversion, ICC should be one of the acceptable options which has a satisfactory long-term result.
Images of thallium-201 cardiac tomography in the 50-degree right-lateral-semidecubital vs. usual supine positions were compared after a single dose of the isotope in 225 patients with or suspected of coronary artery diseases. Compared with the supine position method, the semidecubital position method enabled 25% shortening of the orbital radius (20.0 +/- 0.9 cm to 15.3 +/- 0.6 cm, n = 174, p less than 0.05), higher posteroinferior wall counts in both exercise and 3-hour-delayed images by up to 18%, better image sharpness and contrast, less motion artifact, more marked redistribution in the ischemic walls, and significantly higher specificity (57% vs. 78%, p less than 0.05) and accuracy (63% vs. 79%, p less than 0.05) for inferior wall lesions. The results indicate that the thallium cardiac scan is significantly affected by patient position during scanning, i.e., artifactual inferior wall defects due to photon attenuation in the supine position method. The semidecubital position method is recommended to minimize this artifact. The method is simple, easy to perform, well tolerated, feasible in any 1-headed tomography system, inexpensive, and free of running costs.
Our induction immunosuppressive therapies were carried out on patients split into three groups. The first group of 25 recipients were treated with regimen I [cyclosporin (CsA); 12 mg/kg/day and prednisolone (Pred)]. The second group of 16 recipients were treated with regimen II [CsA; 6 mg/kg/day, Pred and mizoribine (MIZ) or azathioprine (AZA)]. The third group of 14 recipients were treated with regimen III [CsA; 10 mg/kg/day, Pred and MIZ or AZA]. There was no significant difference among the three groups in renal function three months after renal transplantation. The frequency and grade of rejection were significantly higher in Group II than in the other groups. One of group I had CsA nephrotoxicity and none of group III had liver dysfunction three months after renal transplantation. Group I had a higher incidence of posttransplant hypertension. Hypertension of group I was very severe. We concluded that the triple-drug therapy on group III was the best induction immunosuppressive therapy after renal transplantation of the above three.
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