The Vienna protocol and perspectives in radionuclide therapy.

The Vienna protocol for [153]Sm-EDTMP-therapy is based on the experience of the last two decades. Repeated treatments at a low dose are applied by several authors in order to achieve the maximum therapeutic effect with the lowest haematological toxicity. Significant benefits on pain palliation and some regression are documented. In contrast to earlier claims, [153]Sm-EDTMP treatment should be started as soon as more than 1 bone lesion appears in bone scintigraphy and/or bone pain becomes evident. Prospective randomized controlled studies, however, are urgently warranted in order to assess benefits beyond bone pain palliation on an evidence base. The combination with chemotherapy as well as radiotherapy may further improve the clinical results. Further research should be directed to identify underlying mechanisms of response and predictors of benefit and to elaborate an improved therapeutic schedule for further enhancing the response rate.

Platelet function after single [153Sm]EDTMP therapy in prostate cancer.

AIM: Aim of the study was to assess whether [153Sm] EDTMP therapy at a low-dose is associated with platelet activation. METHODS: In 29 patients suffering from metastatic prostate cancer platelet count and various platelet function parameters have been monitored for 2 months after a single (the first) application of 1.1 GBq mCi [153Sm]EDTMP. RESULTS: After 3 days insignificant signs of platelet activation (increase in malondialdehyde, adenosine diphosphate-induced platelet aggregation, decreased platelet sensitivity) occur, normalizing rapidly. At the nadir of platelet count (3-4 weeks) platelet aggregation response in non-count adjusted samples is somewhat lower, while activity per cell (count adjusted samples) is unchanged. Platelet proteins do not change at all. Insignificant activation of platelet function at day 3 is interpreted as an indicator of mild oxidation injury, late aggregation response changes in non-adjusted samples seem only to reflect temporarily decreased number of circulating platelets. Samarium-153-EDTMP therapy at doses (1.1 GBq) used in the Vienna-protocol is not associated with a significantly altered functional behavior of platelets. CONCLUSIONS: We conclude that a single dose of 1.1 GBq 153Sm-EDTMP does not significantly affect in vivo and ex vivo platelet function.

Should lidocaine be avoided for local anesthesia in radiation synovectomy?

AIM: Leakage is of major concern when performing radiation synovectomy. Although post-treatment immobilization was provided, extra-articular leakage of radioactivity has occasionally been observed in patients receiving local anesthesia in the course of radiation synovectomy. This study was performed to uncover any unfavourable effect of lidocaine on stability of (166)Ho-FHMA (ferrum hydroxide macroaggregate). METHODS: The radiopharmaceutical was investigated in bovine serum albumin (BSA) solutions (5, 10 mg/ml) at pH 6, 7 and 8. Furthermore, the tracer was incubated for 0, 2, 24, 48 and 120 hours in synovial fluid. In both series the influence of lidocaine-HCl 2% (500, 1000 microl) has been evaluated. RESULTS: In BSA test solutions, amount of lidocaine added [df(2), F=7.82, p-level: 0.00] and pH [df(2), F=7.82, p-level: 0.00] significantly influenced in vitro stability of (166)Ho labeled FHMA (n=72). This finding was confirmed in synovial fluid [df(2), F=3.82, p-level: 0.03] (n=60). CONCLUSION: In an experimental design mimicking normal and inflammatory conditions in the joint, addition of a few milliliters of lidocaine-HCl followed by a shift towards lower pH-values in synovial fluid may endanger stability of the carrier-tracer complex (166)Ho-FHMA and thereby enhance extra-articular leakage.

(Iso) Prostaglandins in saliva indicate oxidation injury after radioiodine therapy.

UNLABELLED: As salivary glands concentrate radioiodine the radiation injury associated with 131I-therapy may result in sialoadenitis and xerostoma leading to a lasting impaired quality of life. Recently we reported about prostaglandin concentration changes as biochemical markers for radiation injury. Isoprostanes, a new family of prostaglandin-like compounds, have been demonstrated to be reliable markers for oxidation injury in vivo. PATIENTS AND METHODS: In this study we examined the levels of 8-epi-PGF2alpha, the major member of the isoprostane family in 24 patients undergoing 1311 treatment in different doses for hyperthyroidism and differentiated thyroid cancer. 6 healthy sex and age-matched volunteers were monitored in parallel. Saliva(iso)prostaglandins were determined before 131I treatment, as well as 1, 3, 7, 14, 21, and 28 days, and 2, 3, and 6 months after therapy. RESULTS: 8-epi-PGF2alpha showed a significant 1311 dose-dependent temporary increase. The alterations were comparable in all investigated patients and significantly higher in cigarette smokers. TXB2 and 6-oxo-PGF, showed a dose-dependent increase too. TXB2 was higher in cigarette smokers and 6-oxo-PGF1alpha lower as compared to non-smokers. CONCLUSION: These results clearly demonstrate a dose- and time-dependent tissue (TXB2, 6-oxo-PGF1alpha) and oxidation in-jury (8-epi-PGF2alpha) after 131I-therapy in the salivary glands.

Professional athletes suffering from familial hypercholesterolaemia rarely tolerate statin treatment because of muscular problems.

AIMS: Muscular problems are the major group of side-effects during statin treatment. They are known to occur much more frequently during and after exercise. METHODS AND RESULTS: For the last 8 years we have monitored 22 professional athletes in whom, because of familial hypercholesterolaemia, treatment with different statins was attempted. Only six out of the 22 finally tolerated at least one member of this family of drugs. In three of these six the first statin prescribed allowed training performance without any limitation. Changing the drug demonstrated that only two tolerated all the four or five statins examined (atorvastatin, fluvastatin, lovastatin, pravastatin, simvastatin). Cerivastatin was not among the statins prescribed. CONCLUSIONS: These findings indicate that in top sports performers only about 20% tolerate statin treatment without side-effects. Clinical decision making as to lipid lowering therapy thus becomes a critical issue in this small subgroup of patients.

[Radiation doses deriving from patients treated with (166)Ho-ferric hydroxide]. / Strahlenexposition in der Umgebung von Patienten bei Radiosynoviorthese mit (166)Ho-Eisenhydroxid.

AIM: To estimate radiation doses deriving from patients treated with (166)Ho ferric hydroxide. METHODS: For radiation synoviorthesis about 900 +/- 100 MBq (166)Ho ferric hydroxide was injected into the knee joint of 16 patients. To estimate the radiation exposure of persons in the neighbourhood of the patients measurements of the dose rates were performed at 0.5 m, 1 m and 2 m distance of the treated joint 10 min after tracer injection. Measurements were carried out with and without radiation protection devices of the syringe. RESULTS: The initial values of the dose rate were 11.9 micro Sv/h at 0.5 m, 3.5 micro Sv/h at 1 m and 1 micro Sv/h at 2 m distance, respectively. The whole body doses were 2.9 micro Sv for the physician and 4.6 micro Sv for the technologist. The finger doses for the technologist and the physician were ranging from 65 to 111 micro Sv. After discharge at home other persons might receive 118 micro Sv. CONCLUSION: Our results, under very strict assumptions, clearly demonstrate that the calculated radiation exposure to medical and non medical personnel is well below the maximum annual dose limit. The use of any additional radiation protection device as syringe shielding does not significantly lower radiation exposure.

Daily prickly pear consumption improves platelet function.

Prickly pear is traditionally used by Pima Indians as a dietary nutrient against diabetes mellitus. We examined the effect of daily consumption of 250 g in 8 healthy volunteers and 8 patients with mild familial heterozygous hypercholesterolemia on various parameters of platelet function. Beside its action on lipids and lipoproteins, prickly pear consumption significantly reduced the platelet proteins (platelet factor 4 and beta-thromboglobulin), ADP-induced platelet aggregation and improved platelet sensitivity (against PGI2 and PGE1) in volunteers as well as in patients. Also plasma 11-DH-TXB2 and the WU-test showed a significant improvement in both patients and volunteers. In contrast, collagen-induced platelet aggregation and the number of circulating endothelial cells showed a significant response in patients only. No influence of prickly pear ingestion on peripheral platelet count was monitored. The dietary run-in period did not influence any of the parameters of haemostasis examined. No sex difference was seen. Prickly pear may induce at least part of its beneficial actions on the cardiovascular system via decreasing platelet activity and thereby improving haemostatic balance.

8-Epi-PGF2alpha and 6-oxo-PGF1alpha in human (varicose) veins: influence of age, sex, and risk factors.

The isoprostane 8-epi PGF2alpha is a vasoconstrictive, mitogenic, proliferative, and mild proaggregatory agent. We examined 8-epi-PGF2alpha and 6-oxo-PGF1alpha from venous tissue derived from varicose (venous) surgery by means of a specific radioimmunoassay. A total of 336 samples from 82 patients (50 females, 32 males; aged 22-68 years) were examined. Tissue samples were classified according to normal, dilated, and varicose. Of these, 94 samples from 31 patients (20 females, 11 males; aged 29-64 years) with additional risk factors (cigarette smoking, hyperlipidemia, diabetes mellitus) were determined in the same way. Mean absolute values for 6-oxo-PGF1alpha are not significantly higher for dilated segments followed by varicose and intact samples. No significant age and sex differences can be monitored. Presence of risk factors, however, results in a significantly diminished 6-oxo-PGF1alpha, irrespective of morphology. 8-Epi-PGF2alpha again showed no age and sex dependence, its presence in varicose segments, however, was significantly (p<0.01) decreased. Risk factors resulted in a significantly increased 8-epi-PGF2alpha. These data indicate that the influence of risk factors on vasomodulatory (iso-)eicosanoids of human veins is more pronounced than the actual morphologic stage. Lower 8-epi-PGF2alpha in varicose veins may shift the venous tone toward vasodilatation and contribute to development and progression of varicosis.

Binding of [99mTc]chondroitin sulfate to scavenger receptors on human chondrocytes as compared to binding of oxidized [125I]LDL on human macrophages.

Chondroitin sulfate (CS) used for treatment of osteoarthritis exerts distinct effects on human articular chondrocytes in vitro. We performed a binding analysis with 99mTc-labeled CS (Condrosulf, a commercial CS preparation containing calcium stearate) and cultured human chondrocytes in order to evaluate the presence of specific receptors. Saturation binding at 37 degrees C for 2 h revealed the presence of high-affinity binding sites for CS with a Kd of 2.3 x 10(-9) mol/L and a Bmax of 5.0 x 10(8). Extensive dialysis of Chondrosulf led to a decrease of the binding affinity by 52.5 +/- 19.5% and of the number of CS binding sites/cell by 62.0 +/- 14.0%, demonstrating that the additive present in the Condrosulf preparation enhances CS binding. The nature of the binding site is not yet known but evidence exists in the literature that the scavenger receptor CD36, thoroughly investigated on macrophages, is also found on chondrocytes and might be involved in CS binding. Therefore, we undertook a comparative binding study with human monocytes and labelled LDL and oxidized LDL, the latter being a postulated atherogenic agent in atherosclerosis. For [125I]-LDL binding we found a Kd of 0.45 x 10(-8) mol/L and a Bmax of 0.14 x 10(6) on quiescent monocytes and for [125I]-(ox)LDL binding a Kd of 1.8 x 10(-8) mol/L and a Bmax of 1.3 x 10(6) using LPS-activated monocytes. These data are comparable to the binding affinity found for lipoprotein-proteoglycan-complexes and hence are an indication but not a proof that CD36 is involved in CS binding to human chondrocytes.

Effect of giving up cigarette smoking and restarting in patients with clinically manifested atherosclerosis.

Cigarette smoking, a key risk factor for the development of vascular disease, is associated with an increased 8-epi-prostaglandin (PG) F(2alpha). Elevated 8-epi-PGF(2alpha) has been found in vascular tissue, blood and urine as well. We examined the influence of quitting cigarette smoking in 71 patients (38 males, 33 females; aged 32-67 a) with clinically manifested atherosclerosis and various risk factors. In addition, in eight patients with hypercholesterolemia without clinical manifestation of atherosclerosis quitting smoking was monitored as well. Twenty-six of the patients with manifested atherosclerosis and five with hypercholesterolemia restarted and the isoprostanes in plasma, serum and urine were monitored in these patients as well. Quitting cigarette smoking induces an immediate decline becoming significant after 1 or 2 weeks. Restarting smoking results in an increase in 8-epi-PGF(2alpha) reaching prevalues within almost 1 week. These findings indicate that the in vivo oxidation injury associated with cigarette smoking quickly decreases after quitting but increases soon after restarting immediately.

Enhanced accumulation of the isoprostane, 8-epi-PGF2 alpha, in human aortic and pulmonary valves of patients with coronary heart disease.

The aim of the present study was to investigate whether the isoprostane 8-epi-PGF2 alpha differently accumulates in semilunar valves of patients suffering from coronary heart disease (CHD, n = 19) as compared to valves from healthy heart donors (controls, n = 6). Sections from isolated aortic and pulmonary valves were analyzed by semiquantitative immunohistochemistry. The 8-epi-PGF2 alpha-content was determined by using a specific radioimmunoassay. The accumulation of 8-epi-PGF2 alpha in both valves was higher in CHD-patients in comparison to controls (Aortic valves: 36.49 +/- 11.26% vs. 15.78 +/- 3.04%; pulmonary valves: 46.79 +/- 9.80% vs. 14.99 +/- 3.57%). The results from the radioimmunoassay revealed comparable findings in both groups (CHD vs. controls: 395.95 +/- 86.09 vs. 139.50 +/- 47.46 pg/mg protein in the aortic valves and 430.47 +/- 76.30 vs. 147.33 +/- 53.84 pg/mg protein in pulmonary valves). Pulmonary valves seem to be more susceptible to oxidative stress than aortic valves as evidenced by a higher accumulation of 8-epi-PGF2 alpha in CHD patients. Considering the data presented in this study, we suggest that 8-epi-PGF2 alpha is a valuable indicator of oxidative injury in human semilunar valves.

Effect of black tea on (iso-)prostaglandins and platelet aggregation in healthy volunteers.

Flavonoids among others are found in tea. Many of them were shown to exhibit antioxidative action in vitro. We examined the effect of a 1-month consumption of 500 ml black tea containing 2.0 mg quercetin. While single tea consumption 2 h after finishing the intake did not affect any of the parameters (8-epi-PGF(2 alpha) in plasma and serum, 11-DH-TXB(2) and ADP-induced platelet aggregation) examined at all, 1-week consumption and even more than 1 month regular tea intake significantly decreased most of the parameters. The effect was somewhat more pronounced for females as compared with males, the values for 11-dehydro-thromboxane B(2) (11-DH-TXB(2)) and ADP-induced aggregation reached the level of significance in females only. These data show that regular daily black tea consumption for 1 month improves platelet function and decreases thromboxane and 8-epi-PGF(2 alpha) to a varying extent indicating a reduced in vivo oxidation injury.

Postprandial endothelial impairment and reduced glutathione levels in postmenopausal women.

BACKGROUND/AIM: Postmenopausal age is characterized by a higher risk for coronary heart disease (CHD) and postprandial lipemia is strictly related with the evidence of CHD. The aim of the study was to clarify the vascular effects of postprandial state in postmenopausal women. METHODS: Ten postmenopausal women (mean age 57 +/- 8 years) without vascular risk factors and history of cardiovascular disease underwent an oral fat load test. Endothelial function, expressed as brachial flow-mediated vasodilation (FMV), lipid parameters and reduced glutathione (GSH) were evaluated at baseline and 2, 4 and 6 h after the load. RESULTS: FMV showed a significant decrease at the 2nd hour (2.3 +/- 2.6%, vs. baseline 7.7 +/- 2.8%, p < 0.05) and overlapping to the basal value after 4 h. Triglycerides increased postprandially at the 2nd and 4th hour (1.6 +/- 0.6 micromol/l, 1.8 +/- 0.5 micromol/l vs. baseline 0.9 +/- 0.4 micromol/l, p < 0.05), decreasing thereafter. GSH decreased at the 2nd hour of the postprandial phase (5.1 +/- 1.9 micromol/l vs. baseline 8.4 +/- 1.9 micromol/l, p < 0.05), normalizing successively. At the univariate analysis a negative correlation was found between FMV and triglyceride changes (r = -0.37, p < 0.05) and a positive one between FMV and GSH modifications (r = 0.40, p < 0.05). CONCLUSION: These data demonstrated that postprandial lipemia transiently impairs endothelial reactivity by an oxidative burden, partly dependent to triglyceride increase.

Lymphatic mapping of sentinel nodes in early vulvar cancer.

OBJECTIVE: The aim of the study was to determine the diagnostic accuracy and feasibility of sentinel lymph node (SLN) detection using a gamma probe in patients suffering from vulvar cancer. METHODS: From May 1998 to November 2000, 26 patients with early vulvar cancer, planned for local wide excision or vulvectomy including groin dissection, were eligible for the study. Two to 3 h before the planned procedure we injected technetium(99) m-labeled microcolloid intradermally at four locations around the tumor. Dynamic and static images were recorded using a gamma camera. SLN locations were marked on the overlying skin. In the operating theater SLNs were identified at the beginning of the procedure using a handheld gamma-detection probe. After resection of suspected SLNs a standard unilateral or bilateral groin dissection was performed, subsequently followed by local wide excision or, if indicated, radical vulvectomy. Sentinel node detection using technetium(99) m-labeled microcolloid was compared with final histopathological and immunohistochemical results. RESULTS: Scintigraphy showed focal uptake in all 26 patients. Intraoperatively we detected all sentinel nodes by handheld gamma probe. In 20 patients, one sentinel node was identified unilaterally, while in 6 patients two or more nodes were identified bilaterally. Histologically positive SLNs were found in 9 patients. In our preliminary series we did not find any false-negative SLN. CONCLUSION: Identification of sentinel nodes in vulvar cancer is feasible with preoperatively administered technetium(99)m-labeled microcolloid. We confirm the results of previous studies and improve the evidence that the SLN procedure could be implemented in future therapy concepts.

Oral L-arginine administration attenuates postprandial endothelial dysfunction in young healthy males.

BACKGROUND: Endothelial dysfunction is considered the earliest stage of atherosclerosis. Postprandial phase is associated with a transient impairment of endothelial function concomitantly with the triglyceride-rich lipoprotein increase. This phenomenon may be explained by the oxidative burden induced by triglyceride-rich lipoproteins, reducing nitric oxide bioavailability. OBJECTIVE: To investigate the effect of a diet enriched with L-arginine, the substrate for nitric oxide synthesis on endothelial function in healthy volunteers. METHODS: Endothelial function (expressed as flow-mediated vasodilation (FMV) of the brachial artery), total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, LDL-size, Lp (a) and reduced glutathione (GSH) were evaluated in seven healthy males (mean age 23 +/- 3 years) without cardiovascular risk factors. Measurements were made at baseline and 2, 4 and 6 h after a standardized oral fat load. L-arginine (6 g daily) was administered for 10 days. On the 11th day the oral fat load and the parameters examined previously at entry were repeated. RESULTS: After the first oral fat load, FMV significantly decreased at 2 and 4 h, and overlapped with the basal levels at 6 h. After L-arginine treatment, FMV significantly decreased at 2 h and normalized after 4 and 6 h. Triglycerides increased at 2 and 4 h and decreased after 6 h in both sets of observations relating to before and after L-arginine administration. GSH dropped 2 h after the fat load, both before and after L-arginine. Before L-arginine, FMV exhibited a significant correlation with triglycerides (r= -0.426, P= 0.024) and GSH (r=0.48; P=0.009). After L-arginine, FMV was related to GSH (r=0.39; P=0.03) but not to triglycerides (r= -0.12; P=0.52). CONCLUSION: Postprandial endothelial impairment is partly abolished by L-arginine administration. These data, which require confirmation, suggest the importance of dietary choice for atherosclerosis prevention even in young healthy subjects.

Regular ingestion of opuntia robusta lowers oxidation injury.

The influence of opuntia robusta (prickly pear), a traditionally used dietary nutrient against diabetes mellitus among the American Indian population, was examined in 15 young patients suffering from familial heterozygous isolated hypercholesterolemia. Oxidation injury was determined via 8-epi-PGF(2 alpha)in plasma, serum and urine. Daily consumption of 250 g broiled edible pulp of prickly pear had no influence on body weight and body fat composition. Total cholesterol was lowered (P<0.01) as was LDL-cholesterol (P<0.04). No significant changes were observed either in triglycerides or in HDL. Prickly pear induced a significant decrease in plasma (27.9+/-3.3-->25.6+/-3.2;P<0.03), serum (302.0+/-11.4-->283.2+/-14.5;P<0.0003) and urinary (355.9+/-18.4-->323.9+/-16;P<0.00002) 8-epi-PGF(2alpha)values. The findings on a decrease of 8-epi-PGF(2alpha)were more pronounced in females than in males, the highest significance being found in urine, while, in contrast, the effects on total- and LDL-cholesterol were more pronounced in males. A prerunning 4 weeks period of dietary counseling had no significant effect on either of the parameters examined. These findings indicate that the regular ingestion of opuntia robusta is able to significantly reduce in-vivo oxidation injury in a group of patients suffering from familial hypercholesterolemia. This traditional food of the American Indians thus may have a significant cardiovascular benefit.

Verapamil decreases accumulation of 99Tcm-MIBI and 99Tcm-tetrofosmin in human breast cancer and soft tissue sarcoma cell lines.

99Tcm-methoxyisobutylisonitrile (99Tcm-MIBI) and 99Tcm-tetrofosmin are cationic tracers recognized by the efflux pump P-glycoprotein (Pgp). Verapamil has been shown to be a competitive inhibitor of Pgp, and was one of the first multidrug-resistant reversing agents identified. The aim of this preclinical in vitro study was to evaluate the effects of verapamil on the accumulation of 99Tcm-MIBI and 99Tcm-tetrofosmin in the human breast cancer cell lines MCF-7 and SK-BR-3 and in the human soft tissue sarcoma cell lines SW 982 and SW 1353, in comparison with respective control cells, i.e. without preincubation with verapamil. After preincubation with 10 or 100 microM of verapamil for 15 or 30 min, the 99Tcm-MIBI and 99Tcm-tetrofosmin accumulation in cells was assessed at 10, 30 and 60 min after incubation with these tracers. Addition of verapamil caused a decline in the accumulation of the two tracers at all incubation times, as compared with control cells. These effects of verapamil were neither dose- nor preincubation time-dependent in most cells. Our data indicate that verapamil is not a promising agent for increasing the sensitivity of scintigraphy with 99Tcm-MIBI or 99Tcm-tetrofosmin, or for evaluating Pgp tumour status in these types of tumours.

Increase of isoprostane 8-epi-PGF(2alpha)after restarting smoking.

Isoprostanes are known as reliable markers of in vivo oxidation injury. Cigarette smoking has been shown to be associated with a significant increase in 8-epi-PGF(2alpha), a major member of this family of compounds. Quitting smoking reduces 8-epi-PGF(2alpha) values to normal within a couple of weeks only. In this follow-up we checked the 8-epi-PGF(2alpha), values in plasma, serum and urine in 28 people who restarted smoking after a quitting attempt of various duration. 8-epi-PGF(2alpha)shows a certain increase after restarting smoking reaching a maximum after already 1 week. Continuation of smoking does not significantly further increase 8-epi-PGF(2alpha). These data indicate a fast response of restarting as on quitting smoking on in vivo oxidation injury. The oxidation injury reflected by 8-epi-PGF(2alpha)may be a key pathogenetic mechanism in smoking-induced vascular injury.

Statin induced myopathy does not show up in MIBI scintigraphy.

Statin induced myopathy is the most commonly seen side effect in users of this family of drugs. Their different forms present with either creatine phosphokinase (CK) elevation or not, signs of in vivo oxidation injury or not or a combination of both. The pathogenetic background, however, still remains obscure. As MIBI, beside myocardial and tumour scintigraphy, is useful in detecting muscle metabolic abnormalities, an increased uptake of MIBI in the diseased muscular segments could be expected. We investigated seven patients (five males, two females; aged 36-56 years) with statin induced myopathy with either elevated CK, isoprostanes or muscle pains at varying combinations. MIBI whole-body imaging was done immediately, the patients still being on the respective statin. Sixteen patients (six males, 10 females) suffering from lung or breast cancer and being on statins served as controls. No uptake abnormalities in any muscular segment either in the patients or the control group were seen. Thus, MIBI scintigraphy is not useful, apparently, in diagnosing and eventually localizing statin induced myopathy. These findings indicate that MIBI scintigraphy is of no help for diagnosis and gaining further insight into statin induced myopathy.