Role of the 5-lipooxygenase pathway in obstructive nephropathy.

Leukotrienes are products of the 5-lipooxygenase pathway of arachidonic acid metabolism that possess potent inflammatory properties. We examined the potential role of this pathway in the decrease in glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) observed in rats after unilateral release of bilateral ureteral obstruction (BUO) of 24 hours duration. Isolated glomeruli from rats with BUO produced significantly greater amounts of leukotriene B4 (LTB4) than glomeruli from sham-operated rats (SOR; P less than 0.0001). Glomeruli from rats with BUO given MK886, an inhibitor of the 5-lipooxygenase enzyme, or from rats with BUO subjected to both total body irradiation to prevent the leukocyte infiltration of the kidney and also given MK886 prior to obstruction, produced amounts of LTB4 not significantly different from those in glomeruli of SOR. Glomeruli from rats with BUO that had only total body irradiation prior to obstruction produced significantly less LTB4 than glomeruli from untreated BUO rats, but LTB4 production was still significantly greater than in glomeruli from SOR. There were no significant differences in GFR among SOR, SOR given MK886, and SOR subjected to total body irradiation. However, SOR given MK886 had significantly higher ERPF and lower renal vascular resistance (RVR) than SOR not pretreated with the lipooxygenase inhibitor. Rats with BUO given MK886, or subjected to total body irradiation, or both, prior to obstruction had significantly greater GFR and ERPF values and lower RVR than untreated BUO rats. Glomeruli from rats with BUO which were not pretreated had three times the leukocytes of glomeruli from SOR. This leukocyte infiltrate was composed of macrophages (about 55%) and neutrophils (about 45%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Testicular function after radioiodine therapy in patients with thyroid cancer.

Our aim was to assess testicular function in patients treated with high-dose radioiodine. Luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone levels were determined in 52 men with thyroid carcinoma before and 6, 12, and 18 months after radioiodine therapy (3.7-5.5 GBq (131)I; mean, 4.25 GBq (131)I) (group 1) and were also determined before and 18 months after the last radioiodine therapy in 22 patients who received high cumulative activities (13-27.7 GBq; mean, 20.3 GBq (131)I) (group 2). FSH levels were increased 6 months after therapy in all patients of group 1, while a decline was observed after 12 months, with 37 of 52 (71%) subjects presenting normal values. FSH values returned to normal after 18 months in all patients. In group 2, 12 of 22 (54.5%) patients presented elevated FSH and 8 (66%) of these individuals had oligospermia. Six months after radioiodine, increased LH levels were observed in only 5 of 52 (9.6%) patients of group 1, which returned to normal after 12 months, and in 5 of 22 (22%) of group 2. All patients showed normal testosterone levels. We conclude that 131I therapy may cause impairment of testicular function. A generally transient increase in FSH is highly common but is usually reversed within 18 months. Oligospermia was common (one third) after high cumulative (131)I activities. Becausee we did not perform a spermiogram before therapy, we cannot state that high cumulative (131)I activities cause permanent infertility. We recommend the routine use of sperm banks in the cases of men who still wish to have children and who will undergo therapy with (131)I activities of 14 GBq or more or in the case of patients with pelvic metastases.     

Oxidizing and reducing responses in type 1 diabetic patients determined up to 5 years after the clinical onset of the disease

Oxidative stress has been suggested to be the mediator of hyperglycaemia-induced diabetic complications. For this study we asked whether a significant imbalance between oxidizing and plasmatic reducing responses could be observed in DM1 patients receiving intensive therapy up to 5 years following the clinical onset of the disease. A total of 16 type 1 diabetic patients (DM1) without complications and 13 non-diabetic subjects were enrolled. Clinical and biochemical parameters were compared in the two populations studied. Moreover, reactive oxygen species (ROS) generation by granulocytes and the total plasma antioxidant status were simultaneously evaluated. Granulocytes-ROS derived and plasma antioxidant status were determined by chemiluminescence assay and tetrazolium dye reduction, respectively. Type 1 diabetic patients were receiving intensive therapy by multiple daily injections. In comparison with healthy individuals, DM1 patients exhibited an increase in ROS generation whilst plasma antioxidant status was unaltered and appeared to be sufficient to prevent the onset of typical oxidative stress. The clinical characteristics and the remaining biochemical parameters studied were similar for the two groups, except for a significantly decreased plasmatic level of uric acid in DM1 patients. This study suggests that the absence of complications in DM1 patients up to 5 years after onset of the disease may be associated with the oxidizing and reducing balance which need to be maintained in order to prevent or delay the onset of oxidative stress. The effective diabetic control involves evaluation of the oxidizing/antioxidant balance besides glycaemic control.     

Safety of radioiodine therapy in patients with thyroid carcinoma younger than 21 years

We studied 20 patients with differentiated thyroid carcinoma undergoing radioiodine therapy (> or = 100 mCi dose) before the age of 21: 10 patients without distant metastases received a mean dose of 145 mCi and 10 with lung involvement received 270 mCi. One or more years after ablative therapy, xerostomia was present in two patients but was not accompanied by more severe complications such as oral ulcers or fissures, and 99mTcO4- scintigraphy confirmed salivary dysfunction. One patient showed keratoconjunctivitis sicca. Blood counts did not reveal abnormalities caused by radioiodine therapy. FSH was normal in 18 patients. Patients with elevated levels had received radioiodine just over a year ago and repetition of the exam after 6 months showed that FSH had returned to normal. The 6 male patients had normal LH and testosterone levels. Analysis did not reveal signs of pulmonary fibrosis secondary to treatment in the 10 cases with iodine-accumulating metastases in this organ. Our data suggest that ablative therapy employing a dose of 100 to 300 mCi is safe in young individuals, but persistent complications such as salivary dysfunction and conjunctivitis may occur.     

Transferring Conditioned Partially Edentulous Ridge Form to a Master Cast

Gingival conditioning techniques in prosthodontics aim to overcome bone and soft‐tissue defects that often compromise the outcome of restorations in terms of esthetics, function, and biocompatibility. Whatever the technique used, it is essential to reproduce a regular concave gingival outline in order to recreate the natural aspect of the relationship between teeth and gingiva, eliminating black triangles. Transferring the details of the conditioned soft tissue to the laboratory technician with precision may be challenging. The authors hereby propose a novel technique to transfer the clinical aspect of the conditioned soft tissue to the master cast, using a customized metal framework to help ensure accuracy.