Renal tubular necrosis associated with anagrelide administration: a case report

A 62-year-old female patient with essential thrombocythemia experienced rapid renal dysfunction and was subsequently referred to our hospital. Further investigations did not reveal any significant abnormalities except for a slight increase in urinary β2-microglobulin levels. A renal biopsy was performed to investigate the cause of her renal dysfunction, revealing acute tubular necrosis, interstitial edema, and arteriosclerosis. No significant glomerular lesions were observed. Immunofluorescence staining and electron microscopy showed no abnormalities. She had been using anagrelide for 4 years, and her dosage was increased from 2.0 to 3.0 mg/day 10 months before her initial admission. Her renal function began to deteriorate 2 months after the anagrelide dosage increase. Although 0.625 mg of bisoprolol was initiated for tachycardia 3 months after the anagrelide dosage adjustment, we suspected that the acute tubular necrosis was associated with anagrelide administration. After transitioning from anagrelide to hydroxyurea and discontinuing bisoprolol, her renal function improved. This case suggests the importance of considering anagrelide as a potential cause of renal dysfunction in patients using this medication. Therefore, renal biopsy, combined with a comprehensive medical history, is crucial for evaluating the etiology of renal injury in such cases.

Improvement of Light Chain Proximal Tubulopathy without Crystals in IgGλ-type Monoclonal Gammopathy of Undetermined Significance Using Bortezomib and Dexamethasone

A 70-year-old woman with acute kidney injury, a high serum Creatinine (Cr) level (3.91 mg/dL), and proteinuria (protein/Cr ratio 1.59 g/gCr) was admitted. Serum IgG λ-type and urinary λ-type M proteins were observed. A bone marrow examination indicated monoclonal gammopathy of undetermined significance (MGUS). A renal biopsy showed distended proximal tubular cells, and immunofluorescence identified tissue positive for proximal tubular cell λ light chains. Electron microscopy identified fibril-like structures in the lysosomes. The patient was diagnosed with light chain proximal tubulopathy without crystals in IgG λ-type MGUS and treated with bortezomib and dexamethasone therapy, which improved her renal function.

Proteinuria and Renal Dysfunction Due to Extremely Low Birth Weight in a Patient with Silver-Russell Syndrome

A 36-year-old woman diagnosed with Silver-Russell syndrome during childhood presented to our department after a primary care physician suspected renal dysfunction. At birth, she had an extremely low weight (1210 g), and in childhood, she was diagnosed with Silver-Russell syndrome. At the age of 14 she was found to have proteinuria; however, the condition was never further examined. One month prior to her presentation to our department, the following were noted: 3+ urinary protein, 3.9 urinary protein/creatinine ratio, and 48 mL/min/1.73 m² estimated glomerular filtration rate. Abdominal computed tomography revealed small kidneys difficult to visualize using ultrasound. Therefore, an open renal biopsy was performed. The renal biopsy revealed no significant findings in the glomerulus except glomerular hypertrophy, and the glomerular density in the cortical area was low (0.6/mm²). The patient was diagnosed with oligomeganephronia. Proteinuria and renal dysfunction were likely due to glomerular hyperfiltration resulting from a low nephron count caused by low birth weight. Silver-Russell syndrome is characterized by intrauterine growth retardation and additional developmental disorders after birth. Here, we detected oligomeganephronia following kidney biopsy in a patient with Silver-Russell syndrome. We suspect that a reduced number of nephrons due to low birth weight caused proteinuria and renal dysfunction.

Predictive Value of Total Small-Vessel Disease Score for Recurrent Stroke in Patients Undergoing MaintenanceHemodialysis

OBJECTIVES

We sought to examine the validity of the total small-vessel disease (SVD) score in patients receiving maintenance hemodialysis by investigating its predictive value for recurrent stroke.

METHODS

We identified 159 patients who showed acute ischemic stroke while receiving maintenance hemodialysis at our institute between January 1, 2008, and December 31, 2020; retrospectively calculated the total SVD score for each patient; and extracted data on demographic factors and comorbidities that could potentially affect recurrent stroke. Death was thought to be a potential competing risk for recurrent stroke because the perceived risk of death was considerably higher than the risk of recurrent stroke in these patients. Thus, we investigated the association between the total SVD score and recurrent stroke by analyzing the competing risk of non-stroke death.

RESULTS

The median (interquartile range) age was 72 (62-80) years. A total of 38 (23.9%) recurrent strokes occurred, and 69 (43.4%) patients died during the 505 patient-year follow-up study. The estimated cumulative incidence of recurrent stroke at five years was 13.3%, 13.4%, 24.1%, 50%, and 60% for scores of 0 to 4, respectively, and the hazard ratio (HR), adjusted for variables that had been reported to be risk factors of stroke in dialysis patients, per unit increase in the score was 1.72 (95% CI, 1.34-2.21; p<0.001).

CONCLUSION

A higher total SVD score was associated with an increased risk of recurrent stroke in patients undergoing maintenance hemodialysis.

An Autopsy Case of Disseminated Varicella Zoster Virus Infection during the Treatment of Nephrotic Syndrome

A 68-year-old woman developed systemic blisters while receiving treatment for nephrotic syndrome. As she also developed marked liver dysfunction and disseminated intravascular coagulation, she was admitted to our hospital. She was diagnosed with varicella zoster virus (VZV) infection. Treatment was administered in the intensive-care unit, but the patient died on day 24 post-admission after severe VZV infection. A post-mortem examination showed micro-abscesses and necrosis caused by varicella zoster infection in multiple organs, including the liver, kidneys, and gastrointestinal tract. Because VZV infection can become severe in immunocompromised patients, careful consideration is needed for the prevention and treatment of the viral infection.

IgM monoclonal gammopathy with heavy-and-light-chain amyloidosis resembling fibrillary glomerulonephritis determined by tandem mass spectrometry: a case report

BACKGROUND

Fibrillary glomerulonephritis (FGN) is distinguished from amyloidosis by thicker fibrils and the lack of staining with histochemical dyes typically reactive with amyloid. However, congophilic FGN has been proposed recently and adding laser microdissection followed by mass spectrometry (LMD/MS) to conventional pathological methods would be helpful to diagnose FGN. Here, we report a patient initially diagnosed with FGN whose final pathological diagnosis was changed to immunoglobulin heavy-and-light-chain amyloidosis (AHL) after LMD/MS.

CASE PRESENTATION

A 75-year-old male developed nephrotic syndrome. Protein electrophoresis showed IgM κ type M proteinemia and he was diagnosed with IgM monoclonal gammopathy. A renal biopsy was performed and pathological examination showed marked periodic acid-Schiff-positive enlargement of the mesangial region and silver stain positivity, but weak direct fast scarlet staining. Immunofluorescence analysis showed monoclonal deposition of IgM-κ chain in the glomerulus. Under electron microscopy, the fibrils were about 20 nm in diameter, which was thicker than typical amyloid fibrils. Based on these findings, the patient was diagnosed with FGN. Although cyclophosphamide and prednisolone were administered, his renal function deteriorated and progressed to end stage renal disease requiring maintenance hemodialysis. As congophilic FGN has been recognized since 2018, Congo red staining and LMD/MS were performed. The Congo red staining was positive and LMD/MS results indicated that this was a case of AHL.

CONCLUSIONS

We reported a case of μ and κ chain AHL resembling FGN requiring LMD/MS for definitive diagnosis. Since FGN and amyloidosis exhibit pathological findings, even if Congo red staining is positive, LMD/MS needs to be considered in cases atypical pathological findings, such as silver stain positivity or thicker fibrils.

Correction: Effect of statin on life prognosis in Japanese patients undergoing hemodialysis

[This corrects the article DOI: 10.1371/journal.pone.0224111.].

Sex differences in uric acid levels in kidney transplant recipients and their donors: a preliminary retrospective cross-sectional study

Background

Higher serum uric acid (UA) levels are associated with poorer renal prognosis. In kidney transplantation, both donors and recipients are diagnosed as having chronic kidney diseases (CKD) based on renal function; however, their UA levels slightly vary. Elucidating the differences in UA would help improve kidney prognosis, especially for recipients. Therefore, we investigated UA levels in kidney transplant recipients by comparing them to those in their donors.

Methods

In this retrospective cross-sectional survey, background information and blood examination results were collected from the donors just before donation and after transplantation in the donors and recipients. Associations between UA and sex estimated glomerular filtration rate (eGFR), and body mass index (BMI) were evaluated. Data were assessed by the Wilcoxon rank-sum test for continuous variables and the chi-squared test for categorical variables; multiple linear regression analyses were performed to determine which factors were associated with renal function before and after transplantation.

Results

Participant characteristics were as follows. The mean donor age (n = 45, 16 men and 29 women) was 55 ± 11 years, and the mean recipient age (n = 45, 25 men and 20 women) was 46 ± 16 years. Sex-related differences (UA levels in men were predominant) existed in the UA of donors before (P < 0.001) and after donation (P < 0.001). Conversely, there were no significant sex-related differences in the UA of recipients (P = 0.51); the mean standardized eGFRs were similar in donors and recipients after transplantation. Multivariate linear regression analysis showed donor UA only correlated with donor sex before donation (P = 0.008). After donation, donor UA was associated with donor sex (P = 0.006), eGFR (P < 0.001), and BMI (P = 0.02). Notably, the UA of recipients after transplantation was only associated with eGFR (P = 0.003).

Conclusions

Sex has less impact on UA in recipients than in donors. UA has a greater impact on renal prognosis in women than men, even at the same UA level. Therefore, attention should be given to UA levels in female recipients. These findings can be useful for determining patient prognosis following kidney transplantation in both donors and recipients.

Effect of statin on life prognosis in Japanese patients undergoing hemodialysis

The effect of statin on hemodialysis patients is controversial. Although previous large-scale studies did not clarify its effect in this population, recent studies suggest that statins could be useful in reducing the risk of cardiovascular events and all-cause mortality in specific groups of patients undergoing hemodialysis. The aforementioned large-scale studies included a small percentage of Asians, and few studies have investigated the effects of statins in Asians undergoing hemodialysis. Thus, we investigated the benefits of statins in patients undergoing maintenance hemodialysis at a single center in Japan. We obtained demographic, clinical, and hemodialysis data of all patients who underwent maintenance hemodialysis at the Nagasaki Renal Center between July 2011 and June 2012. Patients were followed-up until June 2018. We studied 339 patients, of which 51 (15.0%) were prescribed pitavastatin. The mean observation period was 4.1±2.3 years, 43% were women, and the median hemodialysis vintage at baseline was 4.7 years. During the follow-up, 198 patients (58%) died, of which 22 (43%) were prescribed pitavastatin and 176 (61%) were not prescribed any statins. After propensity score matching based on age, sex, dialysis vintage, dialysis time, diabetes mellitus, ischemic heart disease, dry weight, left ventricular ejection fraction, and serum albumin, an intergroup comparison between those who received statins and those who did not (44 patients in each group) showed significant differences in survival rate based on the log-rank test (P<0.05). Although the causes of death did not differ significantly between groups, deaths due to cardiovascular events, infections, and cancer were fewer in the group prescribed statins. Our results suggest that statins may reduce mortality in Japanese patients undergoing maintenance hemodialysis. Although potential residual confounders exist, statins may have an influence on the reduction in the incidence of cardiovascular events, infections, and cancer. Nevertheless, further studies are required to prove this hypothesis.

Association between serum calcium levels and prognosis, hematoma volume, and onset of cerebral hemorrhage in patients undergoing hemodialysis

BACKGROUND

High serum calcium levels should be avoided in patients on hemodialysis (HD) because they can induce cardiovascular diseases and worsen the patient's prognosis. In contrast, low serum calcium levels worsen the prognosis of patients with cerebral hemorrhage in the general population. So far, whether serum calcium levels in patients on HD are associated with cerebral hemorrhage remains unknown. This study aimed to reveal the association between serum calcium and cerebral hemorrhage in patients on HD, including in-hospital death, volume of hematoma, and onset of cerebral hemorrhage.

METHODS

This cross-sectional case-control study included 99 patients on HD with cerebral hemorrhage at a single center between July 1, 2007 and December 31, 2017. Controls included 339 patients on HD at a single HD center between July 1, 2011 and June 30, 2012. Data on serum calcium level, patient demographics, and comorbid conditions were collected, and associations between cerebral hemorrhage and subsequent death were evaluated by multivariate logistic regression analysis. Further, the association of these backgrounds and hematoma volume was evaluated by multiple regression analysis.

RESULTS

Of the 99 patients, 32 (32%) died from cerebral hemorrhage. The corrected serum calcium level (odds ratio [OR], 2.49; 95% confidence interval [CI], 1.43-4.35; P < 0.001) and antiplatelet drug use (OR, 3.95; 95% CI, 1.50-10.4; P = 0.005) had significant effects on the prognosis. Moreover, the corrected serum calcium (P = 0.003) and antiplatelet drug use (P = 0.01) were significantly correlated with hematoma volume. In the patients, the corrected serum calcium level (OR, 1.54; 95% CI, 1.07-2.22; P = 0.02) was associated with the onset of cerebral hemorrhage, as was pre-hemodialysis systolic blood pressure (per 10 mmHg) (OR, 1.40; 95% CI, 1.23-1.59; P < 0.001).

CONCLUSIONS

Although the precise mechanisms remain unknown, a high serum calcium level is associated with cerebral hemorrhage in patients on HD. Thus, we should pay attentions to a patient's calcium level.

Membranous Nephropathy with Crescent after Hematopoietic Cell Transplantation

A 44-year-old man who received allogenic hematopoietic stem cell transplantation after being diagnosed with acute myeloid leukemia developed nephrosis when the dose of tacrolimus was tapered. A renal biopsy showed the granular deposition of immunoglobulin G in the glomerular basement membrane and subepithelial electron-dense deposits, crescent formation, C4d-positive staining of the peritubular capillary, and subendothelial swelling, suggesting that the main pathological diagnosis was membranous nephropathy and that chronic graft-versus-host disease played a role in the etiology of nephrosis. We herein report a case of membranous nephropathy with various pathological findings. C4d deposition suggests complement activation and the involvement of humoral factors.

A case of mild phenotype Alport syndrome caused by COL4A3 mutations

In a case of 41-year-old man with mild nephropathy, Alport syndrome (AS) was diagnosed from the renal biopsy. However, the α5 chain of type IV collagen expressed in the glomerular basement membrane, which was the atypical staining pattern of AS. Genetic testing suggested autosomal recessive AS from heterozygous mutations at two positions in the type IV collagen α3 chain. These two gene mutations represented a new pattern of mutation and was suggested the association with an atypical α5 chain expression and mild phenotype.

A Comparative Study of the Hemoglobin-Maintaining Effects Between Epoetin-β Pegol and Darbepoetin-α in Patients with Chronic Kidney Disease During 3 Months Before Dialysis Initiation

Background and Objective

We compared the hemoglobin-maintaining effects between continuous erythropoietin receptor activator (CERA) and darbepoetin-α (DA) in patients with chronic kidney disease (CKD) during the 3 months before dialysis initiation.

Methods

This study was conducted with 37 CERA-administered patients and 26 DA-administered patients who had initiated dialysis at a participating facility between January 2012 and December 2014. We investigated clinical laboratory data 3 months before and at dialysis initiation, and compared these data between the CERA and DA groups.

Results

No significant differences in hemoglobin level or reticulocyte count were found between the two groups 3 months before dialysis initiation. However, at dialysis initiation, the hemoglobin level (CERA 9.82 ± 1.52 vs. DA 8.79 ± 1.07 g/dL; P = 0.003) and the reticulocyte count (CERA 5.21 ± 2.95 vs. DA 3.15 ± 1.62 × 10⁴/μL; P = 0.004) were significantly higher in the CERA group than in the DA group. Moreover, the extent of changes in the erythropoietin resistance index during the 3 months before dialysis initiation was significantly increased in the DA group compared with the CERA group.

Conclusions

Our results suggest that CERA may be more effective than DA in maintaining hemoglobin levels in patients with CKD during 3 months before dialysis initiation.

Serum Endocan as a Predictive Marker for Decreased Urine Volume in Peritoneal Dialysis Patients

Background

Endocan is expressed in vascular endothelial cells, and its expression is enhanced following endothelial injury via inflammatory cytokines. Subsequently, endocan is secreted into the circulation. Thus, serum endocan levels are considered a marker of endothelial injury. However, to the best of our knowledge, no data on the serum endocan levels in peritoneal dialysis (PD) patients are available.

Material/Methods

This study included 21 PD patients who underwent peritoneal equilibration test (PET) more than once between 2011 and 2015. Serum samples were collected from each patient, and the 24-h urine volume was measured at the time of PET. Serum endocan levels were measured using enzyme-linked immunosorbent assay (ELISA) at the time of the first PET, and their relationship with clinical data or the extent of urine volume decline (mL/year) was analyzed retrospectively.

Results

Serum endocan levels were positively correlated with proteinuria level, serum creatinine level, serum tumor necrosis factor (TNF)-α level, β₂-microglobulin level, and PD drainage volume, but not with urine volume at baseline. The extent of decline in urine volume was significantly associated with serum endocan level, proteinuria level, serum creatinine level, and serum TNF-α level at baseline in a simple linear regression analysis. Moreover, multiple linear regression analysis showed that the serum endocan level and proteinuria level at baseline were independent predictors for the extent of decline in urine volume.

Conclusions

The results of this study indicate that serum endocan level and proteinuria level may be useful predictive markers for decreased urine volume in PD patients.

Continuous inflammation and ascites 10 months after the initiation of peritoneal dialysis

A 38-year-old man underwent peritoneal dialysis (PD) in May 2011 due to chronic renal failure with chronic glomerulonephritis. In early February 2012, he underwent laparoscopy to salvage and correct a malpositioned PD catheter. The laparoscopic intra-abdominal findings revealed turbid ascites and multiple fibrin lumps, despite the patient's lack of history of peritonitis. Based on these findings, in addition to the presence of continuous inflammation and ascites, a diagnosis of pre-encapsulating peritoneal sclerosis was suspected, and the treatment was switched from PD to hemodialysis. The administration of prednisolone at a dose of 20 mg/day and peritoneal lavage resulted in a decrease in the ascites and fibrin lumps.

Tuberculous osteomyelitis in the ulna of a patient undergoing hemodialysis

A 76-year-old woman on hemodialysis (HD) presented with pain and swelling in the left wrist and forearm. The osteomyelitis occurred in the part of the ulna adjacent to the arteriovenous fistula. Mycobacterium tuberculosis was identified in pus obtained from the left forearm, leading to a diagnosis of tuberculous osteomyelitis. The patient was treated with anti-tuberculous drugs and her symptoms improved. In this study, we report a case of tuberculous osteomyelitis occurring in the ulna, which is not the usual site of predilection for tuberculosis infection. As HD patients exhibit a high frequency of extrapulmonary tuberculosis, tuberculous osteomyelitis should be considered in the differential diagnosis of infectious osteomyelitis. In addition, it may be useful to perform stab cultures at an early stage in order to diagnose tuberculous osteomyelitis.

De novo minimal change disease after ABO-incompatible kidney transplantation

We report the clinical and pathological findings of a case of de novo minimal change disease (MCD) after ABO-incompatible living kidney transplantation. A 62-yr-old man with end-stage renal disease associated with type I diabetes received ABO-incompatible kidney transplantation from his 58-yr-old wife. Although allograft function was excellent immediately after surgery, massive proteinuria (35 g/d) appeared on post-transplantation day 5. After the allograft biopsy taken on post-transplantation day 6, he was treated with 12 cycles of plasma exchange, but the nephrotic-range proteinuria showed no remission. The biopsy specimen showed no significant pathological findings on light microscopy, but electron microscopy showed diffuse effacement of podocyte foot processes. Based on the diagnosis of de novo MCD, the patient received intravenous methylprednisolone pulse therapy, followed by high-dose steroid maintenance therapy. The steroid therapy induced complete remission of nephrotic syndrome and stable allograft function immediately, which was also maintained at one yr after the transplantation.

A case of minimal change nephrotic syndrome with immunoglobulin A nephropathy transitioned to focal segmental glomerulosclerosis

A 50-year-old woman with a 1-month history of lower extremity edema and a 5 kg weight increase was admitted to our hospital with suspected nephrotic syndrome in October 1999. Urine protein level was 3.5 g per day, 10-15 erythrocytes in urine per high-power field, and serum albumin level 2.5 g/dl. Furthermore, an accumulation of pleural effusion was confirmed by chest X-ray. The results of a renal biopsy indicated slight mesangial proliferation in the glomeruli by light microscopy, and an immunofluorescence study confirmed the deposition of immunoglobulin (Ig) A and C3 in the mesangial area. Diffuse attenuation of foot processes and dense deposits in the mesangial area were observed by electron microscopy. Treatment with 40 mg/day of prednisolone was effective, and proteinuria was negative 1 month later. Because of this course, we diagnosed minimal change nephrotic syndrome complicated by mild-proliferative IgA nephropathy. In November 2000, there was a relapse of nephrotic syndrome, which was believed to be induced by an influenza vaccination, but response to increased steroid treatment was favorable, and proteinuria disappeared on day 13 of steroid increase. A second relapse in May 2001, showed steroid resistance with renal insufficiency, and an increase in the selectivity index to 0.195. Light microscopy revealed focal sclerotic lesions of the glomeruli, and an immunofluorescence study revealed attenuation of mesangial IgA and C3 deposition. These findings led to the diagnosis that minimal change nephrotic syndrome had transitioned to focal segmental glomerulosclerosis, whereby mesangial IgA deposition was reduced by immunosuppressive treatment. Subsequently, her renal function gradually worsened to the point of end-stage renal failure by 27 months after the second relapse of nephrotic syndrome.

Bacterial peritonitis due to duodenal perforation by a fish bone in an elderly peritoneal dialysis patient

The patient, a 77-year-old-man, began peritoneal dialysis (PD) in August 2005. In January 2009, he developed lower abdominal pain and cloudy PD effluent. A diagnosis of peritonitis was made and Escherichia coli was detected in cultures of the PD effluent. An abdominal computed tomography scan showed a fish bone in the duodenal wall. An upper gastrointestinal endoscopy was performed, and a 3-cm fish bone was removed. We thus recommend careful investigation with the possibility of enteric peritonitis from the intestinal tract when E. coli is detected in effluent cultures during PD.

An elderly patient with diabetic nephropathy complicated by ANCA-associated nephritis

A 67-year-old man, on oral therapy for type 2 diabetes mellitus since 1990, had sustained proteinuria since 2005. When hematuria was first discovered in 2008, renal dysfunction [creatinine (Cr), 1.2 mg/dL], inflammation [C-reactive protein (CRP), 12 mg/dL] and high myeloperoxidase anti-neutrophil cytoplasmic antibodies (MPO-ANCA) levels [546 ELISA units (EU)] were observed. Renal biopsy showed the diagnosis of ANCA-associated nephritis combined with diabetic nephropathy. For this patient, there was pathological proof of the combination of diabetic nephropathy and ANCA-associated vasculitis.

[Case in which renal function improved following stent-graft placement in the aorta two months after the onset of stanford type B acute aortic dissection]

A 48-year-old man was admitted to the Department of Cardiovascular Surgery in our hospital after developing Stanford type B acute aortic dissection with a patent false lumen in July 2008. Conservative treatment involving rest and antihypertensive therapy was provided following admission. Urine volume decreased from day 9, and serum creatinine increased to 7.7 mg/dL. As it was suspected that the reduced renal blood flow was caused by progression of aortic dissection, contrast-enhanced computed tomography (CT)was performed. The left kidney showed reduced enhancement and the right kidney was heterogeneously enhanced. The dissection had extended to the left renal artery, and the reduced renal blood flow caused by narrowing of the left renal artery was thought to have caused the renal dysfunction. As elevated urea nitrogen and serum creatinine levels and hyperkalemia persisted, hemodialysis was performed a total of four times. Although the patient was subsequently withdrawn from dialysis, he continued to display severe renal dysfunction and was transferred to our department on day 28 for the treatment of renal failure. Conservative treatment was continued, but the maximum diameter of the thoracic aorta gradually increased, and stent placement at the entry of aortic dissection was indicated. On day 86, two stent-grafts were placed for entries at the distal site of the descending aorta and the distal site of the aortic arch. Postoperative abdominal contrast-enhanced CT showed expansion of the true lumen, and blood flow and contrast enhancement improved in both kidneys. Postoperatively, serum creatinine gradually decreased, improving to 1.16 mg/dL on day 96. Renography in the third month after stent-graft placement showed improved renal function in both kidneys. These findings suggest that even at approximately 2 months after the onset of acute renal failure associated with aortic dissection, renal function can be improved by restoring blood flow in the renal arteries.

Membranous nephropathy complicating nasopharyngeal carcinoma

The patient was a 38-year-old woman diagnosed with nephrotic syndrome. Steroid pulse therapy and mizoribine was started in late October 2002 and continued for about 10 months, but no apparent therapeutic effect was obtained. During this period, the patient was diagnosed with nasopharyngeal carcinoma. As nephrotic syndrome did not improve, renal biopsy was performed and membranous nephropathy (MN) was diagnosed. After resection of nasopharyngeal carcinoma was performed, the urinary protein level decreased rapidly. Since MN caused by nasopharyngeal carcinoma is very rare, this represents an interesting case of malignancy-associated MN.

Correlation between NO-induced ATP depletion and cytotoxicity in PC12 cells

To ascertain whether NO-elicited cell death is mediated by decreased intracellular ATP, the effect of sodium nitroprusside (SNP), a NO-generator, on ATP content in PC12 cells was examined. After treatment with SNP, the ATP content in PC12 cells was found to decline in a time- and concentration-dependent manner. The decline of ATP content in PC12 cells caused by SNP was found to occur before the appearance of cytotoxicity estimated by MTT staining. In addition, the ATP content of neuronally differentiated PC12 cells, which has been shown to have a higher resistance to SNP than the undifferentiated cells (Nakamura et al., 1997), was less affected by SNP treatment than the undifferentiated cells. These findings suggest that reduction of intracellular ATP content may be one of the mechanisms responsible for the NO toxicity in PC12 cells.