Comparison of cerebral pharmacokinetics of buprenorphine and norbuprenorphine in anin vivosheep model

The pharmacokinetics and time course of blood-brain equilibration of buprenorphine (BUP) and norbuprenorphine (norBUP) in sheep were characterized. Sheep were administered 0.04 mg kg(-1) BUP or 0.6 mg kg(-1) norBUP as 4-min i.v. infusions. The cerebral kinetics were inferred from arterio-sagittal sinus concentration gradients and changes in cerebral blood flow. These data were fitted to physiologically based pharmacokinetic models. BUP cerebral kinetics were best described by a membrane-limited model with a large equilibration delay (half-life of 20 min) between brain and blood due to intermediate permeability (47 ml min(-1)) and a large cerebral distribution volume (595 ml). Significant limitation in permeability (6 ml min(-1)) characterized the cerebral kinetics of norBUP with a cerebral distribution volume (157 ml) giving a blood-brain equilibration half-life (21 min) similar to that for BUP. The logD of BUP and norBUP were 3.93 +/- 0.08 and 1.18 +/- 0.04 (mean +/- SD), respectively. Both compounds revealed slow cerebral equilibration with variations in degree of permeability and distribution volume reflecting the difference in lipophilicity. It is possible that norBUP contributes to the central effects seen after chronic BUP administration as this study demonstrated its entry into the brain.

Rate measurements of the hydrolysis of complex organic macromolecules in cold aqueous solutions: implications for prebiotic chemistry on the early Earth and Titan

Organic macromolecules ("complex tholins") were synthesized from a 0.95 N(2)/0.05 CH(4) atmosphere in a high-voltage AC flow discharge reactor. When placed in liquid water, specific water soluble compounds in the macromolecules demonstrated Arrhenius type first order kinetics between 273 and 313 K and produced oxygenated organic species with activation energies in the range of approximately 60+/-10 kJ mol(-1). These reactions displayed half lives between 0.3 and 17 days at 273 K. Oxygen incorporation into such materials--a necessary step toward the formation of biological molecules--is therefore fast compared to processes that occur on geologic timescales, which include the freezing of impact melt pools and possible cryovolcanic sites on Saturn's organic-rich moon Titan.

Development of silent gastric carcinoid in a type 1 diabetic patient with primer hypothyreosis

Az 1-es típusú cukorbetegség gyakran társul egyéb autoimmun kórképekkel. A parietalis sejtellenes antitestek (PCA), melyek az 1-es típusú cukorbetegek mintegy 20%-ában megtalálhatók, autoimmun gastritis és anaemia perniciosa jelenlétére figyelmeztetnek. A PCA-k a gyomor-H + /K + ATP-ázt károsítják, és hypo-/achlorhydriát, hypergastrinaemiát okozhatnak. Ennek következtében az enterochromaffin-szerű (ECL) sejtek hyper-/dysplasiaja alakulhat ki, mely carcinoid gyomortumor kialakulására hajlamosít. Az ECL-sejtek hyperplasiájából fejlődő gyomorcarcinoidok az autoimmun gastritises vagy anaemia perniciosában szenvedő betegek 4–9%-ában alakulnak ki. A 29 éves, 6 éve 1-es típusú diabéteszben szenvedő, 8 éves kora óta primer hypothyreosis miatt pajzsmirigyhormon-szubsztitúcióban részesülő nőbetegünknél gyomorpanaszok miatt felső panendoszkópia és biopsziás vizsgálat történt. Az endoszkópia többszörös kicsi polipokat mutatott a fundus területén nonantral hypergastrinaemiás (A-típusú) atrophiás gastritissel. A parietalis sejtantitest-vizsgálat pozitív volt, a szérum-chromogranin-A koncentrációja (CgA) 289,7 ng/ml (norm: 98 ng/ml alatt), a TSH-szint 9,93 mIU/L volt. A szövettani vizsgálat carcinoid tumort igazolt. Octreotidterápiát követően parciális gastrectomiát végeztek. Műtét után a szérum-chromogranin-A-szint normalizálódott. A nonatral, többszörös polipok néma neuroendocrin tumort takarhatnak, melyek rendszerint lassan növekvő, benignus viselkedésű endokrin daganatok, de magas malignitású endokrin karcinómák is lehetnek. A specifikus szérum- vagy szöveti chromogranin-A (CgA) és egyéb endokrin tumorra utaló markerek mérésének elérhetővé válásával e tumorok könnyen felismerhetők lehetnek a klinikus számára.

[Temporal artery biopsy may remain positive even after long-term corticosteroid treatment: report of two cases]

INTRODUCTION

Temporal arteritis is the most common systemic vasculitis of the elderly. It is diagnosed with the combination of a clinico-biological syndrome and typical histologic features recognized on temporal artery biopsy (TAB). Cortisteroid therapy is quickly recommended, before the TAB is performed or before the histologic results confirm the diagnosis. It is recommended to perform TAB as soon as possible after the treatment has begun in order to avoid a presumed improvement or normalisation of the histological features.

EXEGESIS

We report the cases of two patients, a 76-year-old woman and a 78-year-old man who had persistent clinical and histological features of temporal arteritis 5 years and one year respectively after corticosteroid therapy was initiated.

CONCLUSION

Histological changes in the temporal artery biopsy may persist for as long as five years in a patient receiving a corticosteroid treatment for temporal arteritis. Even when largely delayed after the beginning of the treatment, temporal artery biopsy may prove to be important in diagnosing persistent temporal arteritis.

Antioxidant measurements

Chemical reactions, including oxidation and reduction of molecules, occur in every cell. These reactions can lead to the production of free radicals. Free radicals react with organic substrates such as lipids, proteins, and DNA. Through oxidation free radicals cause damage to these molecules, disturbing their normal function, and may therefore contribute to a variety of diseases. The anti-oxidation system, which consists of enzymatic antioxidants and non-enzymatic antioxidants, defends against oxidative stress. The aim of this review is to summarize general aspects of methods to measure the antioxidant defence system all in one (total antioxidant capacity) and discuss a number of methods which are currently used for detection of antioxidant properties.

Soluble semicarbazide-sensitive amine oxidase (SSAO) activity is related to oxidative stress and subchronic inflammation in streptozotocin-induced diabetic rats

Diabetes is known to increase the risk of Alzheimer's disease (AD) and vascular dementia via oxidative stress and inflammation. There are speculations that SSAO activity might be related to the development of AD. Our aim was to investigate whether changes of soluble SSAO activity, oxidative stress and inflammation markers are related to each other in diabetes. Soluble and tissue-bound SSAO activities (from serum and aorta, respectively) were determined in streptozotocin (STZ)-induced diabetic rats without insulin treatment, receiving insulin once, or twice daily compared to control animals. After three weeks of treatment soluble and tissue-bound SSAO activities (seSSAO and aoSSAO, respectively), serum total antioxidant status (TAS), high sensitivity C-reactive protein (hsCRP), fructose amine levels and routine laboratory parameters were determined. SeSSAO activity significantly increased in the diabetic groups without treatment and receiving insulin once daily, and a marked decrease in aoSSAO activity was seen in all diabetic groups. Increased oxidative stress was correlated with hsCRP elevation, while hsCRP and seSSAO activity were also significantly correlated. In all groups seSSAO and aoSSAO activities were in negative correlation with each other. Our results support the view that poor metabolic control leads to increased oxidative stress, which in turn may cause the elevation of hsCRP levels. Soluble SSAO on the one hand acts as an adhesion molecule--thus possibly being a factor responsible for the late complications of diabetes--and on the other hand, it may contribute to oxidative stress. Our parsimonious conclusion is that there is a relation between the risk factors of AD and vascular dementia (diabetes, oxidative stress and chronic inflammation) and SSAO activity, which may originate from the vessel wall.

Coexistence of folie communiquée and folie simultanée

Objective. The authors report a case during which they observed serious subtypes of induced delusional psychosis (folie communiquée and folie simultanée) without any common genetic background or premorbid psychosis in the case of the secondary patient. Method. The clinical phenomenology of the case is described. Results. Mild intellectual disability and environmental-psychological factors (social isolation and the symbiotic-like interpersonal relatedness) play an essential aetiological role in the case of the secondary recipient patient. Conclusion. The authors emphasize the importance of subclassification of induced delusional psychosis for further aetiological and clinical research.

In vitro study of elements in herbal remedies

Decreased glucose tolerance is a first sign of diabetes mellitus and therefore rigorous control must be taken in carbohydrate and lipid metabolisms. Herbal remedies (lyophilized extracts of Myrtilli folium and Phaseoli fructus sine seminibus (L1), Myrtilli folium, Phaseoli fructus sine seminibus, and Salviae folium (L2) are traditionally used in mid-European folk medicine and in common adjuvant therapy for the prevention of complications in type 2 diabetes. Significant iron (355.7 +/- 13.8 mg/kg) and zinc (84.73 +/- 1.83 mg/kg) concentration was found in L1 and chromium (3.82 +/- 2.71 mg/kg) in L2. Ion concentrations in teas made from L1 and L2 are relatively low because the quantities of metal ions in teas do not cover the daily need, although the teas are good sources for some elements. According to the Recommended Daily Allowances, the tea of L1 is a good source for iron and manganese, whereas for chromium, the tea of L2 is better. For evaluating the element bioavailability, an in vitro dialysis system was applied to determine the element transfer from tea of the lyophilized sample to the plasma (buffer pH=7.4). Measurements showed that the elements transferred between 6.90% (iron from tea of L2) and 90.05% (chromium from tea of L2) through the membrane from teas to the plasma. Metal ions in teas of herbal remedies might contribute to the favorable therapeutic effect of preventing complications, because they might transfer through the membranes in relatively high percentages.

Association of IgA nephropathy, hypothyroidism and hypercholesterolemia

Immunoglobulin A (IgA) nephropathy can rarely be associated with thyroid disease. We present a case of a young lady with nephrotic range proteinuria, microscopic hematuria, a creatinine clearance of 67 ml/min, biopsy proven IgA nephropathy, in whom hypercholesterolemia persisted after immunosuppressive therapy induced remission of glomerulonephritis. Fluvastatin was given but rhabdomyolysis developed. Unexpectedly, CK remained elevated following discontinuation of fluvastatin. Secondary amenorrhoea prompted endocrine work-up and hypothyroidism was diagnosed. Cholesterol, CK and TSH values became normal within 3 months on L-thyroxin therapy. The literature of the association of glomerular diseases and thyroid illness is reviewed. We would like to draw the attention to the possible association of glomerular pathologies and thyroid diseases and the importance of ruling out hypothyroidism and measuring CK level before starting statin therapy.

Dermatomyosite induite par la pravastatine

INTRODUCTION

The toxic myopathy caused by statins (HMG-CoA reductase inhibitors) is well established. Recent reports add to these effects systemic immune diseases including systemic lupus erythematosus, vasculitis, polymyositis or dermatomyositis.

EXEGESIS

We report a case of dermatomyositis in a 69-year-old patient treated with pravastatin [Elisor]. She presented with typical features of dermatomyositis 2 years after she started a treatment with pravastatin. The treatment was discontinued and she slowly improved, with a transient dermocorticosteroid treatment. Eight other patients with dermatomyositis and chronic treatment with HMG-CoA reductase inhibitors are reported in the literature. All of them presented with classical features of dermatomyositis. The discontinuation of the treatment was followed by spontaneous clinical and biological improvement in 3/9 patients. The other patients received high doses of corticosteroids and improved, except one patient who died of respiratory failure (pulmonary fibrosis) despite the adjunction of oral cyclophosphamide [Endoxan]. In these patients, dermatomyositis can be considered as a severe adverse reaction to HMG-CoA reductase inhibitors although a distinct casual link cannot be definitely established.

CONCLUSION

The increasing prescription of statins has led to the parallel increment of reported side-effects, where autoimmune diseases are now described. Among them, our case of dermatomyositis in a patient receiving pravastatin adds to the eight reported cases in the literature and highlights the potential role of statins as triggers of immune systemic diseases.

[Effect of vitamin E supplementation on the vitamin content of lipoprotein in young men and women]

The effect of supplementary Vitamin E on the vitamin content of lipoproteins in young men and women. Inappropriate vitamin and trace element supplementation may facilitate the development of atherosclerosis. It is known that Vitamin E protects lipids from oxidative stress, while clinical signs of atherosclerosis appear later in women compared to men.

AIMS

(1) The increase of vitamin E in plasma and plasma lipoproteins after 4 weeks of supplementation vitamin E was investigated, (2) furthermore it was tested whether a proportion shift occurs in alpha-tocopherol content of lipoproteins, (3) and checked for gender-related differences in plasma and plasma lipoprotein vitamin E levels before, during and after treatment, (4) plasma CRP levels as a marker of lipid peroxidation were also followed.

METHODS

5-5 young healthy men and women took part in the study, receiving 700 IU/day Vitamin E for one month. Each subject was studied before and at the end of treatment, and also one month after treatment. HDL and LDL-VLDL containing lipoproteins were separated. Vitamin E and hsCRP levels were measured (by HPLC and an immunoturbidimetric method, respectively).

RESULTS

Vitamin E treatment induced in both genders an approximately threefold increase in vitamin E concentration in HDL-cholesterol (8.1 +/- 1.7 micromol/l vs. 22.5 +/- 7.5 micromol/l, p < 0.001), and a twofold increase in LDL-VLDL-cholesterol (22.0 +/- 3.7 micromol/l vs. 49.0 +/- 9.0 micromol/l, p < 0.001). Plasma and HDL vitamin E levels were higher in women than in men at the onset of treatment (6.8 +/- 0.96 micromol/l vs. 9.5 +/- 1.10 micromol/l), but during the treatment these gender-related differences disappeared. When plasma vitamin E concentration were considered 100% and the changes of the vitamin E concentrations of lipoproteins were calculated, it was found that supplementation with vitamin E in men increased the vitamin E concentration of LDL-VLDL cholesterol to a higher extent compared to women (LDL-VLDL % in men: 59.8 +/- 7.43%, in women: 49.3 +/- 7.41%, p < 0.05). All the observed changes regressed one month after cessation of supplementation. The level of hsCRP decreased during vitamin E treatment (1.07 +/- 0.9 mg/l vs. 0.2 +/- 0.14 mg/l, p < 0.001), and remained suppressed after the cessation of treatment (0.37 +/- 0.4, p < 0.01).

CONCLUSIONS

These results support the hypothesis that women at young age are better protected against lipid-peroxidation as compared to men because of higher HDL vitamin E concentrations. Vitamin E supplementation in men eliminates this concentration difference between genders, and also increases LDL-VLDL vitamin E. In both genders high concentration of vitamin E in lipoproteins was associated with low hsCRP concentration.

Insulin treatment decreases the antioxidant defense mechanism in experimental diabetes

BACKGROUND

Hyperglycemia-induced oxidative stress and left ventricular hypertrophy is an independent risk factor for cardiovascular disease. Our aim was to determine the relationship between left ventricular hypertrophy and the total scavenger capacity (TSC) in diabetic rats.

MATERIAL/METHODS

Control animals (n=30) were compared to streptozotocin-induced diabetic rats (n=38) and diabe-tic rats receiving insulin treatment (n=30) for 22 days. Half of the animals received angiotensin II on day 21. The left ventricular mass, TSC and carbohydrate parameters were determined.

RESULTS

Diabetes did not alter left ventricular mass; however, diabetes with insulin treatment was associated with left ventricular hypertrophy. The extent of ventricular hypertrophy did not change significantly in this group after angiotensin II treatment. TSC increased very significantly in diabetic rats. These differences remained high when angiotensin II-treated control rats [CA] were compared with treated diabetic rats [DA] (p<0.005). TSC decreased significantly when diabetic rats were treated with insulin.

CONCLUSIONS

Diabetes results in oxidative stress, which in turn enhances the activity of antioxidant enzymes. This increase in enzyme activity inhibits the subcellular remodeling processes, thus also inhibiting concomitant cardiac hypertrophy. Insulin treatment decreases the activity of the antioxidant system and can enhance the function of other localized tissue-specific growth factors. These changes may contribute to the early onset of cardiovascular damage detected in diabetic patients.

Beneficial effects of aminoguanidine on the cardiovascular system of diabetic rats

BACKGROUND

The study focused on investigating the effect of aminoguanidine on cardiovascular damages in diabetes and the possible mechanisms of its action.

METHODS

Aminoguanidine (AMNG) was used to treat streptozotocin-induced diabetic rats, and the effects were compared to those obtained under insulin treatment. Blood metabolic parameters, *NO and ONOO- as well as protein carbonyl levels and cardiac hypertrophy were determined.

RESULTS

Diabetic animals showed increased *NO levels and markedly increased ONOO- generation in the aorta, along with a significant hypertrophy and protein carbonylation in the cardiac tissue. Both AMNG and insulin treatment suppressed the levels of overproduced *NO or ONOO- in the vasculature, but only AMNG was able to prevent hypertrophic alterations and reduce protein carbonylation in the cardiac tissue.

CONCLUSIONS

Oxidative protein modification, together with cardiac hypertrophy and high generation of *NO and ONOO-, are important early events in the development of cardiovascular complications in diabetes. Aminoguanidine could prevent hypertrophy through inhibition of production of nonenzymatic glycation products rather than via inhibition of *NO production.

ID22: a multitechnique hard X-ray microprobe beamline at the European Synchrotron Radiation Facility

The ID22 beamline is dedicated to hard X-ray microanalysis allowing the combination of fluorescence, spectroscopy, diffraction and tomography techniques in a wide energy range from 6 to 70 keV. The recent installation of an in-vacuum undulator, a new sample stage and the adaptation of various focusing optics has contributed to a great improvement in the capabilities of the beamline, which is now accessed by a wide user community issued from medical, earth and environmental science, archaeology and material science. Many applications requiring low detection limits for localization/speciation of trace elements together with structural analysis have been developed at the beamline on the (sub)micrometer scale. The possibility of combining simultaneously different analytical probes offers the opportunity of a thorough study of a given sample or scientific problem. This paper presents a review of the recent developments of the beamline and a detailed description of its capabilities through examples from different fields of applications.

Impairment of the NO/cGMP pathway in the fasting and postprandial state in type 1 diabetes mellitus

The assessment of the postprandial state in diabetes mellitus has gained importance due to postprandial hyperglycemia being considered as an independent risk factor for cardiovascular disease. Hyperglycemia may contribute to vascular dysfunction through the alteration of the nitric oxide/cyclic guanosine monophosphate (NO/cGMP) pathway. The authors assessed the NO/cGMP pathway in the fasting and postprandial state in 20 type 1 diabetic patients (age: 34.1 +/- 2.6 years, body mass index (BMI): 24.1 +/- 1.3 kg/m (2), duration of diabetes: 16 +/- 2.2 years, HbA (1C): 8.3 +/- 0.4 %, [x +/- SEM], 10 without, 10 with late complications) and 20 matched control subjects (age: 39.7 +/- 1.9 years, BMI: 25.3 +/- 1.1 kg/m (2)). In the fasting state NO end product (nitrite/nitrate) levels did not differ between the diabetic and control group, cGMP levels were found to be significantly lower in the diabetic group (2.5 +/- 0.2 vs. 4.6 +/- 0.6 nmol/l, p = 0.01). A higher level of lipid peroxidation end products (TBARS) was found in diabetic subjects (6.7 +/- 0.4 vs. 5.0 +/- 0.3 micro mol/l, p = 0.004). The diabetic subgroup without late complications had significantly higher nitrite/nitrate levels compared to the patients with complications (57.8 +/- 6.6 vs. 30.4 +/- 4.3 micro mol/l, p = 0.006), their TBARS and cGMP levels were similar. The control subjects responded to the test meal with an increase in the cGMP levels (4.6 +/- 0.6 to 5.5 +/- 0.6 nmol/l, p = 0.02), while in the diabetic group no change was detected. Postprandial nitrite/nitrate levels decreased in both groups, they were significantly lower in the diabetic group. There was no difference between postprandial nitrite/nitrate, cGMP, or glucose levels in the diabetic subgroups. Postprandial glucose levels showed a significant negative correlation with cGMP levels in the diabetic group (r = - 0.50, p = 0.02). The results suggest that in subjects with type 1 diabetes mellitus NO might have an impaired ability to induce cGMP production in the fasting state prior to the development of late specific complications or microalbuminuria under hyperglycemic conditions. Postprandial hyperglycemia is suggested to interfere with endothelial NO action, as shown by the decreased nitrite/nitrate and unchanged cGMP plasma levels in the diabetic group. The impairment of the NO/cGMP pathway both in the fasting and postprandial state that was shown in patients without diabetic complications may be an early sign of hyperglycemia induced vascular damage in type 1 diabetes mellitus.

[Ghrelin: a new peptide regulating the neurohormonal system and energy homeostasis]

Ghrelin: a new peptide regulating the neurohormonal system and energy homeostasis. Research leading to the identification of ghrelin started with the discovery of growth hormone secretagogues, continued with the description of ghrelin receptors and ended with description of the chemical structure of ghrelin. However, several aspects concerning the role of ghrelin in physiology and pathophysiology are still under investigation. The majority of ghrelin is produced in the stomach, but it is also expressed in the hypothalamus, pituitary, intestine, kidney, heart, pancreas and gonads. Ghrelin stimulates growth hormone secretion via growth hormone secretagogue receptors, and it increases appetite. Ghrelin secretion in the stomach depends on both acute and chronic changes in energy balance. Presently available data support the hypothesis that the stomach, in addition to its important role in digestion, not only influences pituitary hormone secretion via ghrelin production but it also sends orexigenic (appetite increasing) signals to hypothalamic nuclei involved in the regulation of energy homeostasis. In addition to these main effects, ghrelin influences the cardiovascular, gastrointestinal, reproductive and endocrine functions. It can be anticipated that further research on the physiological and pathophysiological role of ghrelin will lead to a better understanding of neurohormonal processes and the central regulation of energy homeostasis.