Minimal change nephrotic syndrome in a 74-year-old patient following parenteral administration of sheep cells.
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Biomedical subjects
Publications and source records attributed to D O Stichtenoth.
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Nitric oxide (NO) is synthesized from L-arginine by the NO synthases. At present, mainly three NO synthase isoenzyme groups are differentiated: two constitutive NO synthases, responsible for homeostatic cardiovascular and neuronal functions of NO, and an inducible NO synthase. After induction by certain cytokines or endotoxin, this latter isoform produces large quantities of NO with cyto- and bacteriotoxic effects. High amounts of NO, synthesized systemically and intra-articularly, play an important role in inflammatory joint diseases, as shown in animal models of arthritis and in patients with rheumatoid arthritis or spondyloarthropathies. In experimental arthritis, administration of NO synthase inhibitors profoundly reduced disease activity. In humans, beneficial effects of NO synthesis inhibition are inferred from indirect evidence: glucocorticoids, inhibiting induction of the inducible NO synthase, reduce enhanced NO synthesis and disease activity. Thus, selective inhibition of the pathologically enhanced NO synthesis emerges as a new experimental therapeutic approach in the treatment of inflammatory joint diseases.
BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) can block renin release via inhibition of cyclooxygenase (COX). The responsible COX-isoenzyme in man is unknown. Therefore, we assessed the effects of meloxicam, a selective inhibitor of COX-2, and indomethacin, an unselective inhibitor of COX-1 and COX-2, on furosemide stimulated plasma renin activity (PRA). METHODS: In a randomized cross-over design 15 healthy female volunteers received no NSAID or meloxicam 7.5 mg/d for 6 days or indomethacin 25 mg tid for 2 days and 25 mg on the 3rd day. On the control day and on the last day of each treatment the following parameters were evaluated before and after furosemide 20 mg i.v.: PRA measured by RIA, urinary excretion of prostaglandin E2 (PGE2) assessed by gas chromatography-tandem mass spectrometry, urine volume and urinary excretion of sodium, potassium, and creatinine, and serum concentrations of sodium, potassium, and creatinine. RESULTS: Furosemide led to a more than two-fold rise of PRA. Indomethacin as well as meloxicam had no significant effect on basal PRA but inhibited the furosemide-stimulated PRA increase. PGE2 excretion on the control day rose two-fold after furosemide. Meloxicam had no effect on basal PGE2 excretion, whereas indomethacin reduced this parameter by 30%. Both drugs inhibited the increase of urinary PGE2 after furosemide. No drug effects on urine flow nor on electrolytes and creatinine in serum and urine could be observed. CONCLUSION: Meloxicam inhibited furosemide stimulated renin release, suggesting that in man COX-2 is responsible for prostaglandin synthesis mediating renin release.
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Mechanisms regulating the balance of T-helper 1 (Th1) and T-helper 2 (Th2) immune responses are of great interest as they may determine the outcome of allergic and infectious diseases. Recently, in mice, nitric oxide (NO), a powerful modulator of inflammation, has been reported to preferentially down-regulate Th1-mediated immune responses. In the present study, we investigated the effect of NO on the production of Th1- and Th2-associated cytokines by activated human T cells and human T-cell clones. Cytokine secretion was measured in the presence of the NO-donating agents 3-morpholinosydnonimine (SIN-1) and S-nitroso-N-acetylpenicillamine (SNAP). Both NO-donors markedly inhibited the release of interferon-gamma (IFN-gamma), interleukin-2 (IL-2), IL-5, IL-10 and IL-4 by anti-CD3 activated T cells. A preferential inhibition of Th1-associated cytokines was not observed. Neither was nitrite found in the supernatants of activated T cells, nor was specific mRNA for inducible and constitutive NO synthase detectable, indicating that T cells themselves did not contribute to the observed effect of the NO donors. Costimulation with anti-CD28 monoclonal antibodies (mAb) prevented SIN-1/SNAP-mediated down-regulation of cytokine production only in part. In contrast, when T cells were stimulated by phorbol-ester and ionomycin, they were refractory to SIN-1-induced inhibition of cytokine production. When SIN-1 was added after the onset of anti-CD3 stimulation, the inhibitory effect was found to be less pronounced, indicating that SIN-1 may interfere with early signal transduction events. The addition of superoxide dismutase (SOD) and catalase did not restore the effects of SIN-1, demonstrating that the inhibition of cytokines was due to NO and not to oxygen intermediates. Furthermore, 8-Br-cGMP-mediated increase of intracellular cGMP caused the same pattern of cytokine inhibition as observed with SIN-1 and SNAP. Using a single cell assay, these agents were shown to reduce the frequency of IFN-gamma-producing T cells, suggesting that not all T cells are susceptible to SIN-1/SNAP. However, cytokine production by purified T-cell subpopulations (CD4+, CD8+, CD45RA+, and CD45RO+) was equally impaired by NO donors. In conclusion, in contrast to the murine system, our results do not provide evidence that NO preferentially inhibits Th1-cytokine secretion of activated human T cells in vitro.
BACKGROUND: Meloxicam is a new NSAID with selectivity for the inducible cyclooxygenase (COX-2) in vitro. We compared the effects of therapeutically equivalent doses of meloxicam and indomethacin, a preferential inhibitor of the constitutive cyclooxygenase (COX-1), on platelet aggregation and platelet thromboxane formation, which are exclusively COX-1 dependent, physiological renal, and total body prostaglandin E2 (PGE2) production. METHODS: In a randomized cross-over design, 14 healthy female volunteers received meloxicam 7.5 mg per day for 6 days or indomethacin 25 mg three times per day for 3 days; the wash-out period was 5 days, and drug intake was adapted to the menstrual cycle. On the day before treatment and on the last day of each treatment period the following parameters were evaluated: maximum platelet aggregation and thromboxane B2 (TXB2) formation in response to 1.0 mmol/L arachidonic acid; 24-hour urinary excretion of PGE2 and 7 alpha-hydroxy-5, 11-diketo-tetranor-prosta-1, 16-dionic acid (PGE-M), the index metabolites of renal and total body PGE2 synthesis, respectively, were assessed by gas chromatography/tandem mass spectrometry. RESULTS: Maximum platelet aggregation and TXB2 formation were almost completely inhibited by indomethacin (-87% and -99%, respectively; p < 0.001, each) as compared to control (100%), but remained unaffected by meloxicam (-1% and +4%, respectively). Meloxicam showed no significant effects on urinary PGE2 excretion (-13%) and only slight effects on PGE-M excretion (-22%; p < 0.05), whereas indomethacin reduced urinary PGE2 excretion (-43%; p < 0.05) as well as PGE-M excretion (-36%; p < 0.001). CONCLUSIONS: Our data show, that meloxicam 7.5 mg per day is COX-1 sparing in humans in vivo.
S-Nitroso-L-cysteine has been shown to be a circulating metabolite of the L-arginine-derived nitric oxide (NO.) in mammals. We describe here a highly sensitive gas chromatographic-mass spectrometric (GC-MS) method for the measurement of S-nitroso-N-acetyl-L-cysteine, the potential mercapturic acid of S-nitroso-L-cysteine, in human plasma and urine. For use as internal standard (I.S.) in this method we synthesized S-[15N]nitroso-N-[2H3]acetyl-L-cysteine. In plasma (n = 10) and urine (n = 30) samples of healthy humans no S-nitroso-N-acetyl-L-cysteine was detected (detection limit approximately 1 nM). Injecting the I.S. in the rat showed a good recovery of the I.S. but no endogenous S-nitroso-N-acetyl-L-cysteine. Our results suggest that renal N-acetylation of S-nitroso-L-cysteine does not represent a metabolic pathway in man.
OBJECTIVE: In the present randomized, fourway crossover study we determined the effects of two oral doses each of ketoprofen and ibuprofen on platelet aggregation and prostanoid formation in man. METHODS: Twelve healthy female volunteers received for 2 consecutive days, followed by a 5-day drug-free interval, one of the following: ketoprofen 3 x 25 mg per day, or ketoprofen 3 x 50 mg per day, or ibuprofen 3 x 200 mg per day, or ibuprofen 3 x 400 mg per day. The response criteria, determined before and on the 2nd day of each treatment period, were: maximal platelet aggregation in response to 1.0 mmol.l-1 arachidonic acid measured by the method of Born and Cross, thromboxane B2 (TXB2) concentration in platelet-rich plasma after aggregation measured by radioimmunoassay, and PGE-M, the index metabolite of total body prostaglandin E2 (PGE2) production, assessed by gas chromatography/tandem mass spectrometry using 18O2-PGE-M as internal standard. RESULTS: Platelet aggregation was significantly reduced by ketoprofen 3 x 25 mg per day (-57%) and ketoprofen 3 x 50 mg per day (-85%) as compared to control, whereas ibuprofen 3 x 200 mg per day (-3%) and ibuprofen 3 x 400 mg per day (-22%) had no significant effects. TXB2 synthesis was significantly decreased by ketoprofen 3 x 25 mg per day (-72%), ketoprofen 3 x 50 mg per day (-97%) and ibuprofen 3 x 400 mg per day (-48%) as compared to control; ibuprofen 3 x 200 mg per day did not reduce TXB2 formation significantly (-23%). All four treatments reduced 24-h urinary excretion of PGE-M significantly in the range of -39% (ketoprofen 3 x 25 mg per day) to -53% (ibuprofen 3 x 400 mg per day) without significant differences between treatments. CONCLUSION: Our data show that both ketoprofen dosages were more effective in inhibition of platelet aggregation and platelet thromboxane synthesis than ibuprofen in low or high dosage. Total body synthesis of the E-prostaglandins was inhibited by all drug schedules without significant differences between treatments.
We describe a 73-year-old forest owner with widespread erythema, myalgia, and proximal muscle weakness. The clinical signs and the results of electromyography, magnetic resonance imaging, and a muscle biopsy were consistent with dermatomyositis. However, serology was positive for Borrelia burgdorferi. More importantly, B burgdorferi DNA was detected in skin by polymerase chain reaction techniques, and spirochete-like organisms were detected in the muscle by silver staining. Lyme disease with muscle involvement can mimic or trigger dermatomyositis and should be considered in the differential diagnosis of dermatomyositis.
We determined the concentrations of nitrate, reflecting endogenous nitric oxide (NO) production, by gas chromatography in the sera of patients with spondyloarthropathy. In those patients with active disease, as indicated by elevated C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) serum nitrate levels (n = 7; mean 73.2 +/- s.d. 21.7 mumol/l) were significantly (P < 0.001) increased in comparison to patients with inactive spondyloarthropathy (n = 7; 31.7 +/- 9.5 mumol/l) and healthy volunteers (n = 10; 33.4 +/- 15.9 mumol/l). The nitrate serum levels correlated closely with CRP and ESR (r = 0.8, P < 0.001, each). There were no major differences in dietary nitrate intake between the study groups. The increased concentrations of serum nitrate in patients with active spondyloarthropathy indicate that NO production is enhanced in these patients.
OBJECTIVES: To determine daily production of nitric oxide (NO) measured as urinary nitrate excretion, and the effect of prednisolone in patients with rheumatoid arthritis (RA). METHODS: Twenty four hour urinary nitrate was measured by gas chromatography in 10 patients with RA, before and two to four weeks after commencement of prednisolone 0.5 mg/kg body weight, and in 18 healthy controls. RESULTS: Before the start of prednisolone treatment the urinary nitrate excretion in patients with RA was 2.7-fold greater (p < 0.001) than that in healthy volunteers. After prednisolone it decreased significantly, by 28%, at which time inflammatory activity (as indicated by C reactive protein, erythrocyte sedimentation rate, joint count, and early morning stiffness) was also reduced considerably. Despite this decrease, the urinary nitrate excretion in patients with RA remained twice that in the control group (p < 0.05). CONCLUSIONS: Our data suggest that the endogenous production of NO is enhanced in patients with RA. Furthermore, the results indicate that, in parallel with suppression of inflammation, this increased NO synthesis could be reduced by prednisolone treatment.
OBJECTIVES: In rats with adjuvant arthritis measurements were taken of the urinary excretion of nitrate, reflecting endogenous nitric oxide (NO) formation, and cyclic guanosine monophosphate (cGMP). METHODS: Urinary nitrate was determined by gas chromatography, cGMP by radioimmunoassay. RESULTS: A significant (p < 0.001), more than three fold increase of urinary nitrate excretion was found in rats 20 days after induction of adjuvant arthritis compared with non-arthritic rats. There was no significant difference in urinary cGMP excretion between arthritic rats and control animals. CONCLUSION: The data suggest that the dramatic increase of urinary nitrate excretion is due to increase of NO synthesis by the inducible form of NO synthase.
In rats with adjuvant arthritis we measured the urinary excretion of 2,3-dinor-6-oxo-PGF1 alpha, 7 alpha-hydroxy-5,11-dioxo-tetranor-prosta-1,16- dioic acid (PGE-M) and 2,3-dinor-thromboxane-B2, reflecting total body synthesis of prostacyclin, thromboxane and the E-prostaglandins, respectively. The urinary prostanoid metabolites were assessed by gas chromatography/tandem mass spectrometry using stable isotope internal standards. We found a more than 10-fold increase of urinary 2,3-dinor-6-oxo-PGF1 alpha excretion and a 5-fold higher urinary excretion of PGE-M in adjuvant arthritic rats as compared to non-arthritic control rats (p < 0.001; n = 12, each). There was no significant difference in urinary 2,3-dinor-thromboxane-B2 excretion between arthritic rats and control animals. Our data show a dramatic increase of urinary 2,3-dinor-6-oxo-PGF1 alpha excretion reflecting increased total body prostacyclin synthesis. It can be assumed that prostacyclin plays a role in generalized inflammatory reactions, comparable to that of the E-prostaglandins.