Immunoglobulin G4-related kidney disease involving the renal pelvis and perirenal fat:A case report

BACKGROUND Immunoglobulin(Ig)G4-related disease(Ig G4-RD)is an autoimmune disease associated with chronic and progressive inflammation and fibrosis.It is difficult to differentiate Ig G4-RD involving the kidney from infectious diseases and malignancy on imaging.CASE SUMMARY We report the case of a 51-year-old Chinese man whose abdominal computed tomography scan showed diffuse bilateral enlargement of the kidneys and perirenal fat,thickening of the renal pelvic walls,and hydronephrosis of the right kidney.Relevant laboratory test results showed a serum creatinine level of 464μmol/L.The patient was diagnosed with acute renal failure and was started on intermittent hemodialysis.Further tests revealed high serum Ig G4 levels(20.8 g/L)and an enlarged right submaxillary lymph node.Biopsy and histopathological examination of the enlarged node led to the diagnosis of Ig G4-RD.After corticosteroid therapy,his serum creatinine level quickly decreased to near normal levels.CONCLUSION Ig G4-RD affecting the renal pelvis or perirenal fat is rare,with atypical imaging features.Multidisciplinary consultation is critical for accurate diagnosis and treatment of this disease.Suspected cases should undergo biopsy to avoid misdiagnosis.

Nicotine Concentration in Leaves of Flue-cured Tobacco Plants as Affected by Removal of the Shoot Apex and Lateral Buds

It is believed that the nicotine concentration in tobacco is closely correlated with the amount of nitrogen （N） supplied. On the other hand, N uptake mainly occurs at the early growth stage, whereas nicotine concentration increases at the late growth stage, especially after removing the shoot apex. To identify the causes of the increased nicotine concentration in tobacco plants, and to compare the effects of different ways of mechanical wounding on nicotine concentration, field experiments were carried out in Fuzhou, Fujian Province in 2003 and 2004. Excision of the shoot apex had almost no influence on N content in the plant; however, it caused dramatic increases in nicotine concentration in leaves, especially in the middle and upper leaves. An additional increase of the nicotine concentration was obtained by removal of axillary buds. The wounding caused by routine leaf harvests, however, did not change the leaf nicotine concentration, and neither did reducing leaf harvest times. The present results revealed no direct relationship between N supply and nicotine concentration in tobacco leaves, and indicate that not all kinds of mechanical wounding were capable of stimulating nicotine synthesis in tobacco plants. Since nicotine production is highly dependent on the removal of apical meristems and hence on the major sources of auxin in the plant, and application of 1-naphthylacetic acid onto the cut surface of the stem after removing the shoot apex markedly decreased the nicotine concentration in different leaves and the total nicotine content in the plant, the results suggest that decreased auxin supply caused by removal of the shoot apex as a kind of mechanical wounding might regulate nicotine synthesis in the roots of tobacco plants.