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Biomedical subjects

H Sinzinger

Publications and source records attributed to H Sinzinger.

At least 91 records · Page 5Linked to original sources
PubMed1999

Increased plasma, serum and urinary 8-epi-prostaglandin F2 alpha in heterozygous hypercholesterolemia.

Oxidation injury results in foam cell formation, which is known to be a central mechanism in atherogenesis. We investigated in this study whether 8-epi-prostaglandin (PG) F2 alpha, an in vivo indicator of oxidative stress, is elevated in hyperlipoproteinemia. The isoprostane 8-epi-PGF2 alpha levels in plasma, serum and urine were determined in 123 patients (67 m, 56 f; 17-60 years) suffering from familial heterozygous hypercholesterolemia (FH). A group of 99 normocholesterolemic adults (51 m, 48 f; 20-63 years) served as controls. Plasma, serum and urine levels of 8-epi-PGF2 alpha were significantly (p < 0.01) higher in the FH group. Smokers showed elevated 8-epi-PGF2 alpha levels; however, no correlation was observed to hypertension, age and sex. Successful dietary and drug treatment of FH patients resulted in a significant decrease in 8-epi-PGF2 alpha levels in plasma, serum and urine. These findings indicate that FH is associated with increased oxidation injury, which is beneficially influenced by successful dietary and/or drug treatment.

Adolescent↗
PubMed1999

Axillary metastases of an occult primary carcinoma of the breast-discovered only by 99mTc-tetrofosmin scintigraphy.

Recent reports consider 99mTc-tetrofosmin scintigraphy to be a powerful new diagnostic tool for discriminating malignant from benign breast disease. We report on a woman suffering from histologically confirmed axillary metastases of a primary unknown, occult carcinoma, whose origin was suspected within the breast. All the diagnostic procedures performed to discover any lesion failed or were inconclusive. The primary cancer was clearly visualized, however, in the right breast by means of 99mTc-tetrofosmin scintigraphy. Conclusion. We suggest that 99mTc-tetrofosmin scintigraphy is a powerful method to detect breast cancer, especially when other diagnostic imaging procedures are inconclusive.

Axilla↗
PubMed1999

99m-Tc-tetrofosmin scintigraphy and breast cancer.

BACKGROUND: 99m-Tc-tetrofosmin holds significant interest among medical oncologists because of its high positive predictive value (>90%) in pilot trials, exceeding sensitivity and specificity rates of mammography. Objective. Our objective was to assess the diagnostic accuracy of 99m-Tc-tetrofosmin whole-body scintigraphy in outpatients. PATIENTS AND METHODS: Thirty-one patients with an abnormal mammograph (n = 22) or follow-up patients (n = 9), 7 of whom were known to have metastatic disease, were included. Tracer (550 MBq) was injected into the cubital vein. Whole-body planar and single photon emission computed tomography images of regions of interest were obtained. Histology, computed tomography (CT), or magnetic resonance imaging (MRI) were performed to confirm scintigraphic results. Correlation between scintigraphy and CT or MRI was assessed by two independent radiologists. Accuracy, sensitivity, and specificity rates for the diagnosis of local and distant breast cancer lesions were given. RESULTS: Of the 22 first-visit patients, 15 had breast cancer, and 7 had no evidence of any malignant disease. Of all patients examined (n = 31), 21 had distant metastases. Breast tumors were correctly diagnosed in 14/15 patients (93%), with only 1 false-negative result. Extrahepatic metastatic lesions (n = 16) were correctly diagnosed in 14 (88%) patients, whereas the method was not suitable for the diagnosis of liver metastases. CONCLUSION: Tetrofosmin scintigraphy has shown very high detection rates of breast tumors and of metastatic lesions and is therefore a valuable option in breast cancer diagnosis.

Adult↗
PubMed1999

A head-to-head comparison between technetium-99m-tetrofosmin and technetium-99m-MIBI scintigraphy to evaluate suspicious breast lesions.

The aim of this study was to assess the diagnostic value of technetium-99m-tetrofosmin and technetium-99m-MIBI in a head-to-head comparison. Both radiopharmaceuticals are routinely used for detecting breast cancer. In a prospective, open, diagnostic trial, the two radiopharmaceuticals were administered randomly on different days to the same 101 women suffering from 103 breast tumours. Planar images and single photon emission computer tomography (SPET) were performed. After histological examination of the tumours, sensitivity, specificity and positive and negative predictive value were compared. 99mTc-tetrofosmin and 99mTc-MIBI showed low sensitivity in planar images (44% vs 46%, respectively). SPET improved sensitivity (70% vs 69%, respectively). Specificity in planar images was 83% and 87%, and it was even lower using SPET (70% vs 78%, respectively). Positive predictive value in planar images was 76% vs 81%, and it was not changed by SPET. Negative predictive value was low in planar images (54% vs 57%, respectively), but it was improved by using SPET (65% vs 67%, respectively). In conclusion, 99mTc-tetrofosmin and 99mTc-MIBI scintigraphy show similar diagnostic value in assessing suspicious breast lesions.

Adult↗
PubMed1999

Effects of PGI2 and analogues (taprostene, iloprost) on oxidation of native and glycated LDL.

Oxidation and glycation of low-density lipoprotein (LDL) has been claimed to play a central role in the pathogenesis of atherosclerosis. Therefore, the inhibition of this processes is of major therapeutic importance. In the present paper the influence of prostaglandin (PG)I2, and its stable analogues taprostene and iloprost on copper-induced oxidation of native, glycated and glycoxidated LDL was investigated. The results show, that the most pronounced effect on inhibition of native LDL-oxidation was obtained by taprostene in the whole concentration range tested (0.2 microg-10 microg/ml) reaching a maximal inhibition of 95% at 10 microg/ml. Examining glycoxidated LDL the inhibitory effect on oxidation was less pronounced reaching only about 10%. In case of glycated LDL, however, no significant inhibitory effect on oxidation was seen. Iloprost was effective as inhibitory agent against oxidation of native LDL at concentrations of 10 and 20 microg/ml, showing a maximal inhibition of 86% at a concentration of 20 microg/ml. Iloprost was ineffective on oxidation of glycated and glycoxidated LDL. Examining the extremely short-lived PGI2 itself, no significant inhibitory effect on oxidation of native, glycated or glycoxidated LDL, however, was seen. This finding might be of relevance for patients with diabetes mellitus, showing a decreased endogenous PGI2-production in particular those with bad metabolic control and high concentrations of circulating advanced glycosylation end products (AGEs).

Adult↗
PubMed1999

Maternal cigarette smoking increases F2-isoprostanes and reduces prostacyclin and nitric oxide in umbilical vessels.

The objective of this study was to evaluate the influence of smoking on F2-isoprostanes, prostacylin and nitric oxide in human umbilical vessels. Umbilical cords from 13 babies of smoking mothers and from 28 babies of non-smoking mothers were examined for levels of F2-isoprostanes, prostacyclin, L-arginine, and L-citrulline. Forty-one umbilical arteries and eleven umbilical veins were analyzed. Statistical analysis of data was done using modified t-test. Cigarette smoking increased F2-isoprostane levels and reduced the generation of prostacyclin, L-arginine and L-citrulline comparably in umbilical arteries and veins. Notably, in umbilical cords of babies of non-smoking mothers the F2-isoprostane level was significantly higher in arteries. Cigarette smoking correlates with a direct vasoconstrictive effect. We suggest that smoking might enhance the vasoconstrictory capacity in umbilical arteries by increased F2-isoprostanes and by a simultaneous decrease in the production of the vasodilatory compounds, prostacyclin, and nitric oxide.

Adult↗
PubMed1999

Platelet labeling with 67Ga chelates.

68Ga-labeled platelets could be useful for positron emission tomographic (PET) studies. In order to identify the optimal chelate for radiolabeling of platelets with 68Ga, we investigated the platelet uptake of 67Ga-oxine, -tropolone and -MPO. The platelet uptake of 67Ga-oxine and -tropolone is very low (< 5%). The platelet uptake of 67Ga-MPO, in contrast, increases with platelet density (highest at 10(9) platelets/ml) up to 18%. Our data provide evidence that only 68Ga-MPO could be useful for PET-studies.

Adult↗
PubMed1999

Vascular 131I-low-density lipoprotein imaging in patients with hypertension and early atherosclerotic lesions in the carotid artery.

BACKGROUND: The reinjection of autologous 131I-labelled low-density lipoprotein (LDL) followed by vascular scintigraphy has been used to investigate lipid-containing plaques, but no information is available on the early stages of plaques in hypertensives. Vascular scintigraphy after re-injection of autologous 131I-labelled LDL was used to investigate early atherosclerotic lesions visualized by sonography in the carotid arteries of patients with hypertension. PATIENTS AND METHODS: 10 male patients (4 smokers; mean age 56 +/- 8 years;) with early carotid atherosclerosis (mono- or bilateral; intima-media-thickness ranging from 1.5 to 3.5 mm) as shown by sonography were studied. All these normolipemic patients suffered from primary hypertension and were treated with diuretics. As controls 6 healthy male subjects (3 smokers; mean age 54 +/- 9 years;), with normal blood pressure and lipid pattern were recruited. RESULTS: Hot spots appeared in the areas with early atherosclerosis in 7 patients, while none were seen in controls. Positive kinetic curves were observed in 4 patients. No significant differences emerged in the target/non-target ratios. CONCLUSIONS: Vascular lipoprotein uptake in hypertensive patients is apparently late and rather limited; the uptake pattern may depend on plaque composition.

Adult↗
PubMed1999

The economy class syndrome--a survey of 19 cases.

BACKGROUND: Thromboembolic events during or immediately after long-distance flights (economy class syndrome--ECS) are gaining more importance due to the rapidly increasing number of flights. Systematic data on haemostatic parameters in these patients are not available yet. PATIENTS AND METHODS: We were therefore analyzing the anamnestic, laboratory and clinical findings in 19 patients (17 males, 2 females, aged 33-75 years) with the final clinical diagnosis ECS. RESULTS: Symptoms commenced either immediately or up to 93 hours after disembarkation (mean 42.3 hours). In the great majority (84.2%) myocardial infarction was the initial diagnosis. No defect in the coagulation and/or prostaglandin system was discovered in either of the patients. Prevalence of smoking (26.3%) was even lower than in the normal population. No predisposing factors were found. Apparent anamnestic similarities were flu and fever (47.4%) while 4 of the patients (26.3%) had severe diarrhoea and dehydration before the flight. Almost all the patients (78.9%) were drinking alcohol during the flight and not actively moving their legs (84.2%). ECS occurred also in business and first class passengers. CONCLUSION: Surprisingly the onset of ECS is definitely not associated with haemostatic defects and not necessarily associated with the clinical risk factors reported.

Adult↗
PubMed1999

Presence of PGE1 binding determines the erectile response to PGE1.

The clinical benefit of PGE1 in erectile dysfunction in men is well proven, while other species including non-human primates show almost no response. The reason for that difference is still unclear. We examined PGE1 binding in human surgical material (n=27) and from transsexual surgery (n=7) as well as rhesus (n=10) and cynomolgus monkeys (n=8) corpus cavernosum tissue. Erection was judged after intracavernous injection of PGE1 in men (10 microg) and in monkeys (5 microg). Human corpus cavernosum shows high- (binding capacity 24.7+/-3.3 pmol/mg protein) and low-affinity (binding capacity 77.4+/-7.3 pmol/mg protein) PGE1 binding sites. Oestrogen (3 mg/day) for more than one month before transsexual surgery decreases receptor density significantly. In rhesus and cynomolgus monkeys no high-affinity binding could be detected, while they respond on PGE1 with slight tumescence only. These findings indicate a significant correlation between corpus cavernosum PGE1 receptor density and the erectile response.

Adult↗
PubMed1999

6-Oxo-PGF1alpha and 8-epi-PGF2alpha in human atherosclerotic vascular tissue.

Isoprostanes are a new family of compounds generated by the free radical catalyzed action on arachidonic acid. Formed during oxidation they have been claimed to be a reliable indicator of in vivo oxidation injury. We assessed the amount of 8-epi-PGF2alpha in human surgical specimens as compared to PGI2 (via its stable metabolite 6-oxo-PGF1alpha), the major compound generated by vascular tissue. 8-epi-PGF2alpha is low in normal vascular tissue as is the 8-epi-PGF2alpha/6-oxo-PGF1alpha ratio. The vessels of smokers in general exhibited an increased 8-epi-PGF2alpha (r=0.82) and a decreased 6-oxo-PGF1alpha (r=0.71). The 8-epi-PGF2alpha/6-oxo-PGF1alpha ratio is, not significantly, increased in vessels derived from hyperlipidemics and hypertensives. These findings indicate that lipid peroxidation occurs within the human arterial wall as evidenced by 8-epi-PGF2alpha, probably further decreasing the synthesis of PGI2 and promoting atherogenic mechanisms.

6-Ketoprostaglandin F1 alpha↗