Polymer-coated hollow fiber for CO(2) laser delivery

Hollow fibers for CO(2) laser light have been fabricated with a cyclic olefin polymer as the inner dielectric. A film of cyclic olefin polymer was coated inside the glass capillary tubing by a simple liquid-flowing process. A polymer-coated fiber with a 700-microm bore showed a loss of 0.06 dB/m for CO(2) laser light because cyclic olefin polymer has low absorption at a 10.6-microm wavelength.

Reversible glomerular hypertrophy in adult patients with primary focal segmental glomerulosclerosis

The present study was performed to assess the pathogenetic role of glomerular hypertrophy in patients with primary focal segmental glomerulosclerosis (FSGS). We studied 14 patients with FSGS by morphometry. In seven patients, minimal change nephrotic syndrome (MCNS) was diagnosed on the first renal biopsy, but FSGS was diagnosed on the second biopsy (MCNS-FSGS group). Seven other patients with FSGS on the first biopsy underwent second biopsies while in remission (FSGS-R group). Biopsy results were compared with biopsies from 10 patients with MCNS and seven control subjects. Nonsclerotic glomeruli were examined. The mean glomerular tuft area, whole glomerular area, and number of mesangial cells were significantly increased in both biopsies from the MCNS-FSGS group and in the first biopsies obtained during the nephrotic stage of the FSGS-R group, compared with control subjects and patients with MCNS. Biopsies from FSGS patients in remission showed that the mean glomerular tuft area and number of mesangial cells were significantly decreased. The fractional extracellular matrix area (extracellular matrix area/glomerular tuft area) and mesangial cell density (mesangial cell number/glomerular tuft area) in FSGS during both nephrotic and remission stages were the same as those in control subjects and patients with MCNS. The present study suggests that glomerular hypertrophy precedes the development of glomerulosclerosis in FSGS and is reversible when patients are in remission. These features support the pathogenetic importance of glomerular hypertrophy in patients with primary FSGS.

[An elderly patient with purpura nephritis that appeared after extracorporeal shock wave lithotripsy]

We report a 63-year-old male patient with purpura nephritis, which appeared 7 days after extracorporeal shock wave lithotripsy (ESWL). He was referred to our clinic because of a petechial rash on both lower extremities, pretibial edema and massive proteinuria. Urinalysis showed proteinuria and hematuria and some hyaline casts. A 24-hour urine sample contained 5.0 g of protein. Renal function on admission was decreased: serum creatinine was 1.5 mg/dl and creatinine clearance, 21 ml/min. Immunoserological tests demonstrated an increase in serum IgA (424.3 mg/dl). A skin biopsy revealed leukocytoclastic vasculitis. A renal biopsy showed endocapillary proliferation in a diffuse, but segmental fashion. However, no crescent formation was seen. Immunofluorescence microscopy disclosed mesangial staining for IgA and C3. Electron microscopy demonstrated severe injury to endothelial and epithelial cells: detachment of endothelial and epithelial cells, foot process effacement and macrophage infiltration. Electron-dense deposits were observed in the subendothelial and paramesangial areas. Because renal function was deteriorating rapidly, methylprednisolone pulse therapy and immunosuppressive treatment were implemented. Treatment was effective and the patient's renal function and proteinuria improved remarkably. The electron microscopic findings in this case of purpura nephritis seemed to be more severe than usual, suggesting that ESWL may aggravate glomerular damage.

Clinical and morphological predictors of renal outcome in adult patients with focal and segmental glomerulosclerosis (FSGS)

In this retrospective study, we examined 35 adult patients with biopsy-proven, primary focal and segmental glomerulosclerosis (FSGS) and nephrotic syndrome to determine whether any of the clinical and morphological features of FSGS were associated with a higher risk of a poor renal outcome. Clinical factors assessed were the age, sex, amount of urinary protein, and presence of microscopic hematuria, hypertension and renal dysfunction at onset in each patient. Morphological parameters included the number of segmental sclerosis and global sclerosis, sclerosis score, location of segmental sclerosis, mean glomerular diameter, grade of tubulo-interstitial changes, and presence of vascular lesions. Twenty-three patients (66%) were in complete or incomplete (partial) remission, and 12 (34%) were non-responders at the end of follow-up. On univariate analysis, the age at onset, sclerosis score, mean glomerular diameter, and grade of tubulo-interstitial changes in no response were significantly greater than those parameters in remission. Multivariate logistic regression analysis revealed that the degree of tubulo-interstitial changes and mean glomerular diameter were independent risk factors for a poor renal outcome. These findings suggest that the estimation of these latter two parameters allows the nephrologist to predict the probable course and prognosis of an adult with FSGS. Intensive and prolonged therapy is recommended for patients without these two morphological features.

Alterations in extracellular matrix components and integrins in patients with preeclamptic nephropathy

The glomerular features of patients with preeclampsia consist of swelling of endothelial cells, subendothelial deposits of incompletely defined material, and thickening of the capillary walls. These abnormalities are thought to resolve in the postpartum period. The distribution of extracellular matrix (ECM) components and integrins was investigated in 10 such patients. Frozen sections and paraffin-embedded sections were stained with antibodies to type IV collagen, laminin (LN), fibronectin (FN), vitronectin (VN), tenascin (TN), fibronectin receptor (FNR), and vitronectin receptor (VNR). In preeclamptic nephropathy, the accumulation of type IV collagen, LN, FN, TN, and FNR was observed in the thickened capillary walls, particularly in the subendothelial layer and, to some extent, in the mesangium. However, deposits of VN were sparse and the distribution of VNR was similar to that in normal kidney. In segmental sclerotic lesions, the amounts of type IV collagen, LN, FN, VN, and TN were increased, whereas those of FNR and VNR were markedly decreased. These results suggest that the materials deposited in the subendothelial space consist of ECM components as well as of plasma-derived proteins, and that the deposition of ECM components and of FNR may be involved in the development and the reparative process of the characteristic glomerular lesions. The formation of sclerotic lesions was linked to the accumulation of ECM components, but not to an interaction with integrins.

Diet-induced hypercholesterolemia increases endothelin-1 release by aortic endothelial cells

Our previous studies demonstrated the morphological heterogeneity of endothelial cells (ECs) and the emergence of large multinucleated ECs in human and animal atherosclerotic lesions. To investigate the functional alteration of ECs in diet-induced atherosclerosis, immunoreactive endothelin-1 (irET-1) release by ECs of the rabbit aorta was correlated with scanning electron microscopy. Rabbits were fed a cholesterol diet for 12 weeks: by scanning electron microscopy, the area of ECs in the aorta increased in the hypercholesterolemic (HC) group as atherosclerosis progressed. Cultured ECs of the HC group released significantly more irET-1 than ECs of the control. The plasma irET-1 level was also elevated in the HC group. The results obtained suggest that accelerated secretion of ET-1 by ECs contributes to the development of atherosclerotic vascular lesions.

[A case of polyarteritis nodosa presenting with multiple intrarenal aneurysms and accelerated hypertension]

A twenty-one-year-old male was admitted to our hospital because of hypertension and proteinuria. He had felt general fatigue and low grade fever for one month. Blood pressure was 180/120 mmHg on admission. Laboratory findings showed 3+ proteinuria and 1+ occult blood in urinalysis; an accelerated erythrocyte sedimentation rate (ESR) of 39 mm/hr; elevation of LDH to 755 IU/l. Antinuclear antibody was positive with a titer of 1: 160, with a speckled pattern. Plasma renin activity and serum aldosterone were markedly elevated to 25.8 ng/ml/hr and 585.3 pg/ml, respectively. Renal function had declined mildly; endogenous creatinine clearance was 60 ml/min. Renal arteriogram demonstrated multiple intrarenal aneurysms in the bilateral kidneys. Aneurysms, 5-8 mm in diameter were located in the arteries from the interlobar to interlobular region. He was diagnosed as having polyarteritis nodosa (PN) and was then treated with 20 mg/day of prednisolone and monthly pulse therapy of cyclophosphamide. After steroid, cyclophosphamide and anti-hypertensive therapy, he became well and had normal blood pressure. The patient was considered a rare case of PN with multiple intrarenal aneurysms and accelerated hypertension. We discuss aneurysms in PN and accelerated or malignant hypertension documented in the literature.

Distribution of thrombomodulin in patients with focal and segmental glomerulosclerosis (FSGS)

Thrombomodulin (TM), an endothelial cell surface glycoprotein, is a regulatory factor in the intravascular anticoagulant system. Furthermore, its plasma level is believed to reflect injury to the endothelial cell. In searching for changes in intraglomerular coagulation and endothelial cell injury during the clinical course of 14 patients with focal and segmental glomerulosclerosis (FSGS), we evaluated the distribution of thrombomodulin (TM) in the kidney by immunohistochemical methods. In the nephrotic stage, intraglomerular staining for TM was weak and segmental and occurred in 6 out of 9 patients (67%), but the incidence of TM expression was not different significantly from that in the normal kidney. Sclerotic lesion was negative for TM. In all patients with incomplete remission and with complete remission, strong and diffuse staining was seen in intra- and extraglomerular endothelial cells. Moreover, TM was scattered in sclerotic lesions. The present study suggest that the over-expression of TM in remission may be linked to recovery from endothelial cell damage and that TM may be closely involved in the repair of FSGS.