A prorenin was isolated from normal human plasma by DEAE-Sepharose column chromatography, 70% ammonium sulfate precipitation and Blue-Sepharose column chromatography. The prorenin had an apparent molecular weight of 46, 000 and 48, 000 daltons as determined by gel filtration on ltrogel AcA 44. When the prorenin was activated by trypsin, α-chymotrypsin, plasmin, pepsin and renin, molecular weights of activated renins were smaller than that of the prorenin. But, human urinary kallikrein and urokinase did not activate the prorenin at all. Trypsin-activated renin was a little different from natural plasma active renin, but the trypsin-activated kallikrein-treated renin coincided with plasma active renin concerning molecular weight (43, 000), Km value (60 nM, for sheep angiotensinogen) and Ki value for pepstatin A (2.6μM). Renin-activated renin had the same molecular and kinetic properties as human kidney renin. When human plasma active renin was treated with neuraminidase, its molecular weight decreased to 38, 000 daltons. These results suggest that cleavage of the specific site in peptide bond of plasma prorenin by various proteolytic enzymes results in different molecular weights of activated renins. Human plasma prorenin was separated into two types, adsorbed and non-adsorbed, by chromatography on a concanavalin-A-Sepharose column, About 80% of it was adsorbed to the column. Non-adsorbed prorenin had a molecular weight of 48, 000 and an isoelectric point of 5.44. Adsorbed prorenin had a molecular weight of 46, 000 and isoelectric points of 5.56 and 5.30. After activation with trypsin, both activated renins were similar with respect to molecular weight (45, 000), thermostability, Km value (0.56μM, for human angiom tensinogen) and pH profile. But, pI values of both activated renins differed. There exist in human plasma two different types of prorenin which differ in carbohydrate composition.

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The biopsized renal tissues from two patients with membranous nephropathy were studied to evaluate the localization of IgG deposit in the glomeruli and its significance by immuno-electron microscopy using the peroxidaseRantiperoxidase complex with antihuman IgG rabbit serum. One patient was a 57-yr-old female with relapsing primary membranous nephritis and the other patient was a 38-yr-old female with lupus nephritis. In the former case, the IgG deposit was locally observed within the glomerular basement membrane and the cytoplasm of the glomerular epithelial cells along the glomerular basement membrane. The IgG deposit in the cytoplasm of the glomerular epithelial cells was not continuously located at the basement membrane where the immune deposits were observed as a high electron density. However, the IgG in the cytoplasm of the glomerular epithelial cells was continuously deposited at the basement membrane where the immune deposits were observed as a lucent electron density. These facts suggest that the immune complex have a specific affinity to the glomerular epithelial cells. In the later case, a number of small immune deposits were scattered in the lamina densa of the glomerular basement membrane with relatively regular distance, and they rarely fused with one another. These findings might be based on a specific evidence in SLE and a functional and structural singularity of the glomerular basement membrane.

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Different types of the glomerular epithelial detachment have been reported in various glomerular diseases. Kidney biopsy specimens from 116 patients were investigated by electron microscopy with special attention to this lesion . The epithelial detachment was classified into 4 types: (1) glomerular basement membrane (GBM) denudation (Type I), (2) epithelial desquamation (Type II), (3) subepithelial protrusion (Type III), and (4) subepithelial expansion (Type IV). Type I was observed in almost all kinds of glomerular diseases, particularly associated with nephrotic syndrome. This lesion, however, was noticed in the cases showing only hema tuna. Type II was accompanied by either GBM abnormalities including attenuation, wrinkling, irregular thickening, splintering, and amyloid deposition, or subepithelial widening with or without electron dense deposits . Type III was seen mostly in the patients with massive proteinuria. It seemed to be the early lesion of segmental sclerosis. Type IV was the most advanced epithelial detachment seen in the sclerotic glomerular tufts. The typical lesion was observed in focal glomerular sclerosis, although it is not pathognomonic. Some of the epithelial detachment such as Type III or IV may possibly develope into segmental glomerular sclerosis, However other unknown factors may also be concerned in this process, since these detachments are commonly seen in various glomerular diseases. In conclusion, the severity of epithelial detachment is correlated with the degree of glomerular damage and proteinuria.

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The immunological disorder in various primary renal diseases (PRD) and lupusnephritis (LN) was analyzed using various mitogens.In vitro proliferative responses of the peripheral blood lymphocytes (PBL) to pokeweed mitogen (PWM) and Staphylococcus aureus Cowan I (STA) were decreased in the nephrotic stages of minimal change nephrotic syndrome (MCNS) and LN. The suppressed responses of PBL to phytohemagglutinin (PHA), concanavalin A (Con A) and STA were restored markedly by depleting monocytes in PRD, while functional defects of the lymphocytes except for the PHA response were present in LN.Meanwhile, in vitro spontaneous production of Ig, in particular IgG and/or IgA, was increased in the nephrotic stages of MCNS and IgA nephropathy (IgA-GN) and the active stage of LN and the mitogen-induced Ig production was rather impaired. From these results, it was indicated that the B cells were activated in vivo in certain typer of PRD and LN and could not expand further in vitro by the monocytes-mediated suppression when stimulated with the mitogens.

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Immunosuppressive factor(s) in sera of six children with minimal change nephrotic syndrome (MCNS) were studied. (1) Phosphatidylinositol (PI) and DNA synthesis of peripheral blood mononuclear cells (PBMs) of healthy donor activated by lipopolysaccharide (LPS), Staphylococcus aureus Cowan I strain (SAC) or pokeweed mitogen (PWM) were suppressed by the sera of MCNS. Those suppressive activities were contained in the fraction of lipoproteindeficient serum (LPDS : d>1.25). (2) PI and DNA synthesis of PWM-activated T or non-T cells were also suppressed by sera of MCNS, especially by LPDS fraction. (3) Sterol biosynthesis of PBMs activated by LPS, SAC or PWM were suppressed by sera of MCNS. However, LPDS fraction of MCNS could not suppress the sterol biosynthesis. (4) The differentiation of B cells to IgM-secreting cells by PWM were suppressed by sera of MCNS and the suppressive activity was contained in the fraction of LPDS. However, it was not cleared whether the LPDS fraction of MCNS suppressed B cell differentiation itself or suppressed it secondly by suppressing the prolif erations of T or B cells.

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In sucrose density gradient analysis of circulating immune complexes (CIC) detected by solid phase anti-C 3 assay, the peak of reactivity usually occupies 7 S fractions. We analysed anti-C 3 assay and interpreted this phenomenon. Pepsin agglutinators (PA) in human serum which are IgG or IgA antibodies to F (ab')₂ of rabbit IgG (also of human IgG) bind to solid phase fixed F(ab')₂ anti-C 3, and are detected as if they were C 3 binding immune complexes. This PA differ from rheumatoid factors, as PA do not react with aggregated rabbit IgG nor human IgG and react only with F (ab')₂. It is necessary to preincubate patient serum with rabbit F(ab')₂-Sepharose 4 B in order to absorb pepsin agglutinators prior to anti-C 3 assay. With this absorbing technique, we made it possible to detect IgA-IgG mixed CIC. Microtyter plate was coated with F (ab')₂ anti-IgA, and×21 diluted patient serum whose PA were preabsorbed was added to incubate 37°C 1 hr.Then the plate was washed, anti-IgG-HRPG was added and incubated 37°C 1 hr., and peroxidase activity was determined. IgG and IgA were mixed, heat aggregated and used as AHG standard. Another clinical or analytical sandwich assay is possible in the same way as anti⋅IgA-anti⋅IgG assay using PA absorbed serum.

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In order to investigate the importance of tubulo-interstitial changes in renal cortex in evaluating the severity as well as prognosis in biopsy specimen of nephritides, follow up studies were conducted in 101 patients with IgA nephropathy (average follow up periods 61 months) and 75 cases of idiopathic membranous nephropathy (average follow up period: 83 months) subsequent to renal checkups. Degree of tubulo-interstitial changes, assayed semiquantitatively by light microscopic observation, was correlated with the severity of glomerular injuries, incidence of other histo-pathological parameters, clinical variables at renal biopsy and status at final follow up. In both diseases, degree of tubulo-interstitial changes were significantly correlated with the severity of glomerular injury, incidence of segmental sclerosis, global sclerosis, arteriolosclerosis as well as such clinical variables as age at biopsy, blood pressure and serum creatinine level The incidence that retained stable renal function at final follow up was more than 90 percent among the cases with tubulo-interstitial changes less than 20 percent of the cortical area, whereas that decreased to less than 67 percent in the cases with more tubulo-interstitial changes in both diseases (p<0.05). It was thus concluded that semiquantitative evaluation of the tubulo-interstitial changes in cortex would reflect the severity of glomerular injury and therefore would contribute to the prognostification of the primary glomerulonephritic patients such as IgA nephropathy and idiopathic membranous nephropathy.

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To investigate Na⁺ dependent phosphate uptake in various conditions, brush border membrane vesicles (BBMV) were purified from rat renal cortices by Ca²⁺ recipitation and porous glass-beads column chromatography. In the presence of 100 mM NaSCN, the peak of the overshoot was observed after incubation for 40 s and the accumulation of phosphate was 5.5 times higher than that in equilibrated state. Phosphate uptake was accelerated by the increase of extravesicular Na⁺ concentration. The Na⁺ dependent uptake of phosphate was followed Michaelis-Menten kinetics in low substrate concentration under 300μM, and the apparent Km and Vmax were 46 .EM and 3.8 nmole/mg protein⋅20 s respectively. Above this concentration, the lower affinity of the phosphate transport system was observed. The elevation of pH of the incubation medium increased the rate of phosphate uptake and in the presence of D-glucose, the uptake of phosphate was inhibited in BBMV. The divalent cations Ca²⁺ and Mg²⁺ did not affect the phosphate uptake, suggesting that these cations could not directly regulate membrane transport of phosphate.

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The killer (K) cell population of peripheral blood lymphocytes was determined by the plaque technique in 35 patients with renal glomerular diseases and 15 normal subjects. The K-cell population correlated well with the antibody-dependent cell-mediated cytotoxicity estimated by measurement of ⁵¹Cr released from labeled target cells. The normal controls showed a K-cell population of 6.5plusmn;1.7 (meanplusmn;S.D.) %, while some patients with various type of chronic glomerulonephritis (GN) and those with poststreptococcal acute GN had marked depression during the active stage, ie, in all four cases of poststreptococcal glomerulonephritis, 17 of 19 cases of primary chronic glomerulonephritis, one case of lupus nephritis and one case of HPs associated nephropathy, a low K-cell population was observed. The decrease of peripheral blood lymphocyte K-cell population was conspicuous in diffuse mesangial proliferative GN and membranoproliferative GN, compared to focal mesangial proliferative GN among various histologic forms of primary chronic GN. A dose-dependent suppression in vitro by adding aggregated IgG of the K-cell population of normal peripheral blood lymphocytes was observed. Furthermore, there was clinical evidence of inverse correlation between the concentration of circulating immune complexes and the K-cell population . It was inferred from the data that the depression of K-cell population in the patients with active phase of acute and chronic GN might be ascribed to inhibition by immune complexes . Such depression was observed, however, in three of nine cases of nephrotic syndrome negative for immune complex as well. This suggests possible participation of some inhibitory factor (s) other than immune complex and points to necessity for further investigation.

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The diagnostic validity for lateralization by abdominal computed tomography (CT), adrenal isotopic scanning, and adrenal venous sampling was studied in 11 patients with primary aldosteronism and 1 patient with idiopathic hyperaldosteronism. All of the patients with primary aldosteronism were subsequently operated and all were found to have histologically adrenal adenomas. CT scann was taken using G. E. 8800 and adrenal scintiscan was carried out after dexamethasone administration to suppress the endogenous ACTH. Adrenal venous sampling was performed under mild sodium restriction. In the cases we failed to insert catheter into the right adrenal vein, lateralization was determined by comparing plasma aldosterone concentrations in renal veins with that in the high inferior vena cava above the renal veins. The CT scan showed in as high as 98% of the patients the exact side of the adrenal lesion, whereas the adrenal scintiscan revealed as low accuracy as 60%. This value was almost the same with the procedure by the adrenal venous sampling (64%). Incorrect preoperative identification by the CT scan and adrenal scintigraphy was 0%, though it was 11% by the adrenal venous sampling. The only one case the CT scan failed to detect was a small adenoma (0.9×0.8×0.7cm), but adrenal venous sampling showed the side correctly. These three examinations were performed in one case of idiopathic hyperaldosteronism, as all the procedures could not disclose a adrenal adenoma. The blood pressure of this patient has been controlled by the treatment with spironolactone for the past ten years.

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We investigated whether ACE in plasma affects or not the renin-angiotensin-aldosterone system in hypertensive subjects. Plasma ACE activity was determined by both methods of Cushman et al, and of Friedland et al. Plasma aldosterone level and plasma renin activity were radioimmunoassayed. There was neither relationship between ACE activity and aldosterone level nor between ACE activity and renin activity in plasma. The plasma ACE activity was slightly related to the plasma angiotensin I and a regression equation was represented as Y=-2.887X+98.7 and a coefficent of correlation was -0476. If plasma ACE activity is high, it may be suggested that the conversion of angiotensin II to angiotensin II will be accelerated. The fluctuation of this conversion would be resulted in the change in concentration of angiotensin I in blood. Our results indicate that the plasma ACE may be the important enzyme as well as renin on pathogenesis of hypertension.

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Compositions of analyzed 233 urinary tract stones from Tsukuba University Hospital and its affiliated hospitals in the southern part of Ibaraki Prefecture were studied with respect to their clinical manifestations. Prevalent ages were from 20's to 50's with the most prevalent being 40's. Male to female ratio was approximately 2.6 to 1. Number of urinary tract stones from upper urinary tract was predominant to those from lower urinary tract with the approximated ratio being 9 to 1. Calcium stones were most predominant component (88.1%) in our series. Regarding the composition of analyzed calculi, there were some findings different from those reported by other authors. Calcium phosphate stone was more prevalent (13.7%). The compound stone partly composed of magnesium ammonium phosphate (MAP) was found only in 1 case, whereas frequency of single MAP stone was not different. Therefore frequency of compound stones in our series was less than expected (40.4%).Differences of stone composition in calcium stone, uric acid stone and MAP stone with respect to sex difference were not different from those of other institutions. Analysis of the stone composition passed spontaneously revealed that calcium oxalate stone, mixed calcium oxalate-calcium phosphate stone, uric acid stone and cystine stone were easy to pass spontaneously, whereas calcium phosphate stone and MAP stone were difficult.

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In order to clarify the pathophysiology of Bartter's syndrome, plasma renin activity (PRA), aldosterone concentration(PAC), noradrenaline level (PNA), plasma volume (PV), extracellular fluid volume (ECFV), total exchangeable sodium (Nae), the pressor response to intravenously infused angiotensin-II (ANG-II-R) and noradrenaline (NA-R), 24 hour urinary excretion of kallikrein(uKAL), kinin(uKIN), and prostaglandins(uPG), fractional excretion of potassium (FE_K) and inorganic phosphorus (FE_P), and fractional delivery (FDCl dis.) and reabsorption of chloride in distal nephrons (FRCl dis.) were measured before and after treatment with indomethacin (IM, 75 mg/day) for two weeks in a 39-yearold female patient with this syndrome, under dietary control with 200 mEq of sodium, 75 mEq of potassium, 0.8g of calcium and 1.35g of inorganic phosphorus. Before IM treatment, this patient had significantly higher values of PRA, PAC, PNA, FEK, FEP and lower values of serum potassium (1.7-0.3mEq/l), PV, ECFV, Nae, ANG-II-R, NA-R, uKIN and uPG than those of an age matched control group. Under maximal diuresis, in this patient, FDCI dism was higher but FRCI dise was lower than those in the patient with psychogenic vomiting described by Gill and Bartter. Following 2 weeks of IM administration, significant decreases in the values of PRA, PAC, PNA and uKAL and increases in serum potassium, PV, ECFV, ANG-II-R, NA-R, uKIN were observed. However, none of these parameters recovered to within normal range. Furthermore, no remarkable changes in FDCl dis. and FRCl dis, were observed after treatment. From the present study, the possibility is raised that an attenuation of sodium chloride reabsorption in the ascending loop of Henle and the proximal tubule might be a primary abnormality of Bartter's syndrome.

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The study was done to clarify the mutual relationship between the clinical and the histopathological findings of idiopathic membranous glomerulonephritis (iMGN). Among the cases with biopsy proved membranous glomerulonephritis (137 cases), 89 (65%) were iMGN. The average age at initial renal checkup was 39.1 yrs and their average follow up period 73 months. Sixty seven cases (75%) presented with nephrotic syndrome at the time of renal biopsy. Complete remission was observed in 32 (43%) among 74 cases that could be followed for more than 2 years.
Eight cases that went into impaired renal function (serum creatinine>1.5 mg/dl) had longer interval between the onset and renal biopsy than those that retained normal renal function. Hypertension accompanied more frequently in such cases.
Electron microscopic findings of the glomerular basement membrane were divided into four stages according to the criteria of Ehrenreich & Churg. Nine cases were classified as Stage I, 26 as Stage II, 37 as Stage III and 11 as Stage IV. All of the cases that went into renal function impairment had Stage III or IV injuries. The prognosis of the cases with Stage II was far better than those with Stage IV (p< 0.05). The cases with tubulointerstitial changes of more than 30% of the renal cortical area had higher incidences of hypertention, renal function impairment and lower percentage of complete remission than those without such changes (p<0.05).
Among the cases that followed for less than 5 years, the rate of complete remission in the patients treated with steroid and/or immunosuppressive drugs was higher than that of the non-treated (p<0.1).
But in the cases that followed for more than 5 years, no such difference was observed. Therefore, spontaneous complete remission could be expected even after more than 5 years following the onset.
The prognosis of iMGN in this study was better than those reported from foreign countries, in spite of severer histopathological findings.

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