A study of non-aromatizing androgen 19-hydroxylase in sheep adrenal

We reported on the unusually high isotope effect of non-aromatizing androgen 19-hydroxylase in sheep and dog adrenals and the validity of the [3H] water method using [19-3H3] androgen. We have extended the study to examine whether this 19-hydroxylation is catalyzed by a cytochrome P-450 dependent enzyme. Sheep adrenal homogenate (1.65 mg prot.) was incubated in the presence of NADPH (5.6mM) with [19-3H3, 4-14C]-androstenedione (A) (3.2 microM, 8.24 x 10(4) dpm 3H/micrograms, 3H/14C = 17.2) in a total of 1.2 ml PO4 buffer under air at pH 7.4 for 2, 5 and 10 min. [19-3H2, 4-14C]-19-hydroxy-A (19-OHA) with added carrier was purified through extraction, TLC, acetylation to form 19-AcOA, and further TLC to give 19-hydroxylase activity as assessed by the product isolation method. Simultaneously, the [3H] water was measured by distillation, and with correction by the apparent kinetic isotope effect (KH/KT = 11.8), used for assessment of 19-hydroxylase activity. The effects on the hydroxylation by cofactor (NADPH, NADH), incubation atmosphere (N2, CO/O2), cytochrome P-450 inhibitors (metyrapone, clotrimazole) and heating were measured by both methods. Compared to the complete system (89.6pmol/min/mg as 100%), carbon monoxide suppressed 15.8, 59.3 and 86.4% of the 19-hydroxylation when a CO/O2 ratio of 0.1, 1 and 9 was used, respectively. Replacement to nitrogen atmosphere decreased the activity by 93.8%. Replacement of NADPH with NADH (7.5mM) caused more than a 92.1% decrease in activity. Metyrapone at 50 and 200 microM and and clotrimazole at 2.5 and 10 microM suppressed the activity by 82.8, 90.4, 85.4 and 94.9%, respectively. A larger scale sheep adrenal incubation of A (250 microM) under 18O2 atmosphere and isolation of 19-AcOA were carried out in a similar manner. The gas chromatography-mass spectrometry analysis of the purified product showed 48.5% of the product to be 18O-labeled as [M+ + 2], m/e 346. Thus, the non-aromatizing androgen 19-hydroxylase requires NADPH and molecular oxygen. It is strongly inhibited by carbon monoxide and cytochrome P-450 inhibitors. These results indicate that the enzyme system responsible for non-aromatizing androgen 19-hydroxylase in adrenal is a cytochrome P-450 dependent monooxygenase.     

Risk factors for invasive aspergillosis in living donor liver transplant recipients.

Invasive aspergillosis (IA) is a severe complication of liver transplantation. Risk factors for IA after deceased donor liver transplantation (DDLT) have been presented in several reports, but are not well established for living donor liver transplant recipients. Here, a retrospective case-control study was performed. Five cases with IA were investigated after living donor liver transplantation (LDLT) between January 1999 and December 2002 at Kyoto University Hospital. For comparison, living donor liver transplant recipients without IA were taken as controls. These patients had undergone LDLT 1 month before or after each IA case and had the same survival times as the latter. We evaluated the clinical and laboratory findings for both groups up until their demise. Patients with IA after LDLT had a very poor prognosis. By univariate analysis, risk factors for IA were preoperative intensive care unit stay (P = 0.02) and preoperative steroid administration (P = 0.02). Preoperative steroid administration for fulminant hepatitis possibly predisposed to the development of IA after LDLT.     

Epinephrine is an enhancer of rat intestinal absorption.

Some physiological substances, including acetylcholine and nitric oxide, are useful candidates for stimulation of intestinal absorption of drugs. In the present study, we elucidated the ability of epinephrine (Epi) to stimulate the intestinal absorption of drugs. We evaluated the ability of Epi to enhance absorption of macromolecules using dextran (Mw 4000 Da), which is poorly absorbed from the intestine, as a model compound in situ in a closed loop of the rat jejunum. Treatment of the jejunum with Epi resulted in significant increase in absorption of dextran in a dose-dependent fashion. The area under the curve (AUC) from 0 to 4 h in the Epi-treated jejunum was 13-fold higher than that in the vehicle-treated jejunum. The absorption-enhancing activity of Epi was 40-fold higher than that of caprate, a clinically used absorption-enhancer of drugs. In the experimental conditions used in this study, histological injury of the mucosa and perturbation of the mucosal membrane were not observed in the Epi-treated jejunum. Treatment with an antagonist of alpha-adrenergic receptors attenuated the stimulation of intestinal absorption by Epi, and treatment with an agonist of alpha-adrenergic receptors resulted in enhancement of intestinal absorption. While an antagonist of beta-adrenergic receptors enhanced the absorption-enhancing effect of Epi, an agonist of beta-adrenergic receptors stimulated intestinal absorption. These results indicate that stimulation of adrenergic receptors may be a novel strategy for intestinal absorption of drugs.     

Treatment of a patient with end-stage renal disease, severe iron overload and ascites by weekly phlebotomy combined with recombinant human erythropoietin

A 41-year-old hemodialyzed woman developed ascites and was found to have secondary iron overload. The dose of administered iron was approximately 11-12 g, and her serum ferritin level was 15,000 ng/ml (15,000 micrograms/l). There were no signs of congestive heart failure, fluid overload, or liver cirrhosis. A program of weekly phlebotomy combined with recombinant human erythropoietin (rhEPO) therapy was tried to eliminate the iron congestion. After 9 months of this therapy, about 5 g of iron had been removed. The ascites completely disappeared, and her serum ferritin level fell to 5,800 ng/ml (5,800 micrograms/l). This suggests that such combined therapy would be useful when iron overload must be corrected rapidly. Before therapy, the sterile ascitic fluid showed exudative characteristics with 3.7 g/dl (37 g/l) of total protein. The serum-ascites albumin difference was 0.6 g/dl (6 g/l), and the fluid contained 1,400 inflammatory cells/mm3 (1.4 X 10(9)/l). Notably, the serum-ascites albumin difference increased in parallel with iron elimination. These findings suggested that iron deposition may have played a role in changing the permeability of the peritoneum, or in impairing lymphatic drainage, both of which are presumed to be pathogenetic factors of nephrogenic ascites.     

Immunological study on chyluria

Immunological studies were performed in 87 patients with chyluria referred to our clinic from January 1982 to December 1988. White blood cell count in 78 patients was 5210.3 +/- 1440.9/mm3. The fraction and the number of lymphocyte were 18.7 +/- 9.5% and 934.1 +/- 521.6/mm3, respectively: they were lower than normal limit. The percentages of T and B lymphocytes studied in 46 patients were 79.3% +/- 11.2% (normal range: 76-86) and 10.4 +/- 7.9% (normal range: 8-16), respectively: both lymphocytes tended to decrease in percentage. Lymphocyte blast formation stimulated with phytohemagglutinin (PHA) was carried out in 20 patients. The mean of the blast formation was 17410.0 +/- 10275.1 c.p.m. (normal range: 377700-62400), and much lower than normal value. Of 22 patients who had PPD skin test, only 9 (40.9%) were positive. These findings signified that cellular immunity was suppressed in patients with chyluria. On the other hand, the value of immunoglobulin was within normal range (IgG: 1325.3 +/- 475.6 mg/dl, IgA: 242.0 +/- 98.3 mg/dl, IgM 130.4 +/- 95.9 mg/dl). Study on the values of laboratory examinations showed statistically positive correlation between total lymphocyte population and T cell number, and between total lymphocyte population and lymphocyte blast formation. In patients with chyluria, serious sequelae have not been reported. However, care should be taken for possible opportunistic infection and, particularly, malignant tumors because suppression of cellular immunity may be one of the promoting factors of malignant tumors.     

An elderly case of idiopathic retroperitoneal fibrosis]

An elderly case of idiopathic retroperitoneal fibrosis (IRPF) with bilateral ureteral obstruction was reported. A 74-year-old man was admitted with complaints of general fatigue and loss of appetite. An elastic hard mass with a smooth surface was palpated in the left upper quadrant of the abdomen. Abnormal ESR and CRP were noticed. Abdominal ultrasonography showed both a homoechoic mass which surrounded the aorta in the retroperitoneal space and bilateral hydronephrosis. Computed tomography revealed a retroperitoneal mass involving bilateral ureters. Magnetic resonance imaging demonstrated a mass with a sharp image and signal intensity. Furthermore the morphological relationship between the mass and the ureters and major vessels clearly indicated the characteristics of benign retroperitoneal fibrosis. Based upon the above findings, a diagnosis of IRPF was made. After confirming the histological diagnosis by biopsy, treatment consisting of bilateral ureterolysis, intra-abdominal transposition of ureters and oral administration of prednisolone was performed, resulting in a normalization of laboratory findings. Analysis of 86 previously cases of IRPF reported up to 1990 in Japan, revealed the peak age to be in the 7th decade with predominance in males (males: females = 57:29).     

Kinetic study of glomerular epithelial cells associated with segmental glomerular sclerotic lesions with adhesion in spontaneously diabetic WBN/Kob rats

Background We previously found that glomerular epithelial cells play an important role in the formation of adhesive lesions. Glomerular sclerotic lesions develop after the inital adhesive lesions. Methods Two series of experiments were done with spontaneously diabetic WBN/Kob rats. These rats develop segmental glomerular sclerotic lesions with aging. The first series of experiments was intended to clarify the kinetics of glomerular cells on progressive glomerular damage in these rats. The second series of experiments was designed to study the relationship between proliferation (judged by % bromodeoxyuridine-positive cells) of glomerlar epithelial cells and sclerotic lesions with adhesions. Results In the first series, rats having increased proteinuria showed segmental glomerular sclerotic lesions with adhesions. At the same time, increased labeling indices of tuft cells and epithelial cells of Bowman's capsule were observed. In the second series, no significant increase in the labeling indices of tuft cells with sclerotic lesions was observed, compared to tuft cells without sclerotic lesions. In sclerotic lesions with adhesion, bromodeoxyurdine-positive cells were observed that were not distinguishable as podocytes or epithelial cells of Bowman's capsule. The highest labelling index was noted in the epithelial cells of Bowman's capsules with sclerosis. Conclusion This study shows that the proliferation of glomerular epithelial cells (mainly epithelial cells of Bowman's capsule) occurs in glomerular sclerotic lesions with adhesions.