Isolation and structure determination of oxidative degradation products of atorvastatin

Methods were developed for the preparation and isolation of four oxidative degradation products of atorvastatin. ATV-FX1 was prepared in the alkaline acetonitrile solution of atorvastatin with the addition of hydrogen peroxide. The exposition of aqueous acetonitrile solution of atorvastatin to sunlight for several hours followed by the alkalization of the solution with potassium hydroxide to pH 8–9 gave ATV-FXA. By the acidification of the solution with phosphoric acid to pH 3 ATV-FXA1 and FXA2 were prepared. The isolation of oxidative degradation products was carried out on a reversed-phase chromatographic column Luna prep C18(2) 10 μm applying several separation steps. The liquid chromatography coupled with a mass spectrometer (LC-MS), high resolution MS (HR-MS), 1D and 2D NMR spectroscopy methods were applied for the structure elucidation. All degradants are due to the oxidation of the pyrrole ring. The most probable reaction mechanism is intermediate endoperoxide formation with subsequent rearrangement and nucleophilic attack by the 5-hydroxy group of the heptanoic fragment. ATV-FX1 is 4-[1b-(4-Fluoro-phenyl)-6-hydroxy-6-isopropyl-1a-phenyl-6a-phenylcarbamoyl-hexahydro-1,2-dioxa-5a-aza-cyclopropa[a]inden-3-yl]-3-(R)-hydroxy-butyric acid and has a molecular mass increased by two oxygen atoms with regard to atorvastatin. ATV-FXA is the regioisomeric compound, 4-[6-(4-Fluoro-phenyl)-6-hydroxy-1b-isopropyl-6a-phenyl-1a-phenylcarbamoyl-hexahydro-1,2-dioxa-5a-aza-cyclopropa[a]inden-3-yl]-3-(R)-hydroxy-butyric acid. Its descendants ATV-FXA1 and FXA2 appeared without the atorvastatin heptanoic fragment and are 3-(4-Fluoro-benzoyl)-2-isobutyryl-3-phenyl-oxirane-2-carboxylic acid phenylamide and 4-(4-Fluoro-phenyl)-2,4-dihydroxy-2-isopropyl-5-phenyl-3,6-dioxa-bicyclo[3.1.0]hexane-1-carboxylic acid phenylamide, respectively. Quantitative NMR spectroscopy was employed for the assay determination of isolated oxidative degradation products. The results obtained were used for the determination of the UV response factors relative to atorvastatin.     

Feasibility of early hospital discharge directly from coronary care unit after primary angioplasty for uncomplicated acute myocardial infarction

Current European and American guidelines recommend early discharge for patients with uncomplicated acute myocardial infarction (AMI). However, this concept has not been widely accepted, and experience with direct discharge from the coronary care unit is limited. We aimed to investigate safety and cost effectiveness of early discharge directly from coronary care unit following successful percutaneous coronary angioplasty (PTCA) in patients with uncomplicated AMI. We included consecutive thirty-one patients with uncomplicated AMI and successful PTCA admitted to coronary care unit of a university hospital. Uncomplicated course was defined as absence of reinfarction, ischemia, VF/VT, repeated PTCA, and heart failure within first 72 hours. Incidence of death, reinfarction, VF/VT, need for revascularisation, and hospitalisation due to heart failure at 1, 6, and 12 months was compared with 56 randomly selected AMI patients with successful PTCA but longer hospitalisation. Average hospital stay was 4 days in early and 6.7 days in control group (p<0.05). Control group had more extensive coronary disease (54% two or more vessels vs. 28% in early discharge, p<0,05). During follow up, none of the early discharged patients died, the only observed event was repeat PTCA due to angina pectoris. In the control group, mortality at 12 months was 3.5% (p<0.05). Cumulative 12 month event free survival was 96% in early discharge group and 87% in control group, but difference was not significant (p=0.15, Cox-Mantel test). Cost reduction of early discharge amounted to 1100 Euro per patient. In conclusions, our study confirmed that for a selected population of patients with AMI, successful PTCA, and uncomplicated clinical course during first 72 hours, discharge as early as three days following the admission is safe.     

In vivo microvascular response of murine cutaneous muscle to ibuprofen-releasing polyurethane foam

In view of their pain-relieving effect, the non steroidal anti-inflammatory drugs are more and more used as a pain-reducing component in modern wound dressings. To analyse the effect on new blood vessel growth, implants from Biatain Ibu, a polyurethane foam containing ibuprofen, were inserted into the dorsal skinfold chamber of BALB/c mice. Implants from ibuprofen-free polyurethane foam Biatain served as controls (n = 10 per group). Blood vessel growth and the functional vessel density (FVD) as a parameter for microvascularization of implant's border zone were assessed by intravital fluorescence microscopy (IVFM). IVFM was performed on days 3, 7 and 12 after implantation. Direct comparison showed no significant differences in FVD (mm/mm(2)) for the border zone of the ibuprofen-releasing implants versus controls on day 3 (185.49 +/- 4.75 versus 197.17 +/- 5.21) and day 7 (229.60 +/- 8.53 versus 247.99 +/- 5.39). However, the IVFM showed a significant increased FVD for ibuprofen-releasing implants (301.30 +/- 8.44 versus 279.24 +/- 5.78) on day 12 (P < 0.05). Also, a significant increase of FVD was detected for the ibuprofen-releasing implants throughout the implantation time of 12 days. This study shows that local release of small-dose ibuprofen from a polyurethane dressing does not decrease new blood vessel growth during the implantation time of 12 days. In the end, the microvascularization of implant's border zones in both groups was found comparatively undisturbed.     

Testing the Finno-Ugrian Suicide Hypothesis: geographic variation of elderly suicide rates across Europe

The pattern of geographic variation in European suicide rates in the high-risk group of individuals aged 65 years and over was investigated, in order to provide a further test of the Finno-Ugrian Suicide Hypothesis, i.e. the assumption that genetic differences between populations may partially account for spatial differences seen in the suicide prevalence. National suicide rates (average of 1970-2002) of the elderly from 34 European countries were regressed on geographic position terms, i.e. capital cities' latitude and longitude, along with transformations (e.g. squared latitude) and interaction terms (e.g. latitude multiplied with longitude) of these, which statistically modeled various possible geographic gradients in the suicide rates. In these regression models, the strongest and statistically significant predictor of elderly suicide rates was an interaction term of squared latitude multiplied with longitude, indicating that suicide rates increased to the northeast. This accounted for 13.8% (total), 20.8% (males) and 11.6% (females) of the cross-national variance in elderly suicide rates. No further geographic position term accounted for a significant increment of further variance in suicide rates over and above this predictor. Controls for national quality of living conditions and alcohol consumption rates left these results essentially unchanged. Replicating previous evidence based on suicide rates of the general population, suicide rates of the elderly show a northeastern gradient across Europe. This J-shaped belt of high-suicide-rate countries spans from Central Europe (Austria, Hungary and Slovenia) to Northeastern Europe (Finland and the Baltic countries). There are early historical and genetic communalities among the populations inhabiting this area, but, in terms of culture, recent history, political systems and socioeconomic factors, there is great diversity between these countries. The current findings thus add to cumulated empirical evidence consistent with the Finno-Ugrian Suicide Hypothesis.     

Truncated tau expression levels determine life span of a rat model of tauopathy without causing neuronal loss or correlating with terminal neurofibrillary tangle load

We have previously demonstrated in a transgenic rat model of tauopathy that human misfolded truncated tau derived from Alzheimer's disease suffices to drive neurofibrillary degeneration in vivo . We employed this model to investigate the impact of truncated tau expression levels on life span, neuronal loss and the final load of neurofibrillary tangles (NFTs) in transgenic rats. Two independent transgenic lines (SHR72, SHR318), that display different expression levels of truncated tau, were utilized in this study. We found that transgene expression levels in the brain of SHR72 rats were 44% higher than in SHR318 rats and that truncated tau protein levels determined the survival rate of transgenic rats. The line with higher expression levels of truncated tau (SHR72) showed decreased median survival (222.5 days) when compared with the line with lower expression (SHR318; 294.5 days). Interestingly, NFT loads (total NFT/total neurons) were very similar in terminal stages of disease in both transgenic lines (SHR72 – 10.9%; SHR318 – 11.6%), despite significantly different expression levels of truncated tau. Moreover, mean neuron numbers in the hippocampus (CA1–3) and brain stem (gigantocellular reticular nucleus) in the two transgenic rat strains in the terminal stages of disease were similar, and did not differ significantly from those observed in age-matched non-transgenic controls. These findings suggest that the expression levels of misfolded truncated tau determine the life span in a transgenic rat model of tauopathy without causing neuronal loss or correlating with terminal NFT load.     

Semaglutide delays 4-hour gastric emptying in women with polycystic ovary syndrome and obesity

Aim

To evaluate the effect of once-weekly subcutaneous semaglutide 1.0 mg on the late digestive period of gastric emptying (GE) after ingestion of a standardized solid test meal by using technetium scintigraphy, the reference method for this purpose.

Methods

We conducted a single-blind, placebo-controlled trial in 20 obese women with polycystic ovary syndrome (PCOS; mean [range] age 35 [32.3-40.8] years, body mass index 37 [30.7-39.8] kg/m²) randomized to subcutaneous semaglutide 1.0 mg once weekly or placebo for 12 weeks. GE was assessed after ingestion of [^99mTc] colloid in a pancake labelled with radiopharmaceutical by scintigraphy using sequential static imaging and dynamic acquisition at baseline and at Week 13. Estimation of GE was obtained by repeated imaging of remaining [^99mTc] activity at fixed time intervals over the course of 4 hours after ingestion.

Results

From baseline to the study end, semaglutide increased the estimated retention of gastric contents by 3.5% at 1 hour, 25.5% at 2 hours, 38.0% at 3 hours and 30.0% at 4 hours after ingestion of the radioactively labelled solid meal. Four hours after ingestion, semaglutide retained 37% of solid meal in the stomach compared to no gastric retention in the placebo group (P = 0.002). Time taken for half the radiolabelled meal to empty from the stomach was significantly longer in the semaglutide group than the placebo group (171 vs. 118 min; P < 0.001).

Conclusion

Semaglutide markedly delayed 4-hour GE in women with PCOS and obesity.     

No evidence of compensatory changes in energy balance,despite reductions in body weight and liver fat,during dapagliflozin treatment in type 2 diabetes mellitus: A randomized,double-blind,placebo-controlled,cross-over trial (ENERGIZE)

Aim

This study assessed the impact of dapagliflozin on food intake, eating behaviour, energy expenditure, magnetic resonance imaging (MRI)-determined brain response to food cues and body composition in patients with type 2 diabetes mellitus (T2D).

Materials and Methods

Patients were given dapagliflozin 10 mg once daily in a randomized, double-blind, placebo-controlled trial with short-term (1 week) and long-term (12 weeks) cross-over periods. The primary outcome was the difference in test meal food intake between long-term dapagliflozin and placebo treatment. Secondary outcomes included short-term differences in test meal food intake, short- and long-term differences in appetite and eating rate, energy expenditure and functional MRI brain activity in relation to food images. We determined differences in glycated haemoglobin, weight, liver fat (by ¹H magnetic resonance spectroscopy) and subcutaneous/visceral adipose tissue volumes (by MRI).

Results

In total, 52 patients (43% were women) were randomized; with the analysis of 49 patients: median age 58 years, weight 99.1 kg, body mass index 35 kg/m², glycated haemoglobin 49 mmol/mol. Dapagliflozin reduced glycated haemoglobin by 9.7 mmol/mol [95% confidence interval (CI) 3.91-16.27, p = .004], and body weight (−2.84 vs. −0.87 kg) versus placebo. There was no short- or long-term difference in test meal food intake between dapagliflozin and placebo [mean difference 5.7 g (95% CI −127.9 to 139.3, p = .933); 15.8 g (95% CI −147.7 to 116.1, p = .813), respectively] nor in the rate of eating, energy expenditure, appetite, or brain responses to food cues. Liver fat (median reduction −4.7 vs. 1.95%), but not subcutaneous/visceral adipose tissue, decreased significantly with 12 weeks of dapagliflozin.

Conclusions

The reduction in body weight and liver fat with dapagliflozin was not associated with compensatory adaptations in food intake or energy expenditure.     

Desynchronization of cortical rhythms following cutaneous stimulation: effects of stimulus repetition and intensity, and of the size of corpus callosum.

OBJECTIVE: Event-related desynchronization (ERD) and synchronization (ERS) of the Rolandic electroencephalographic (EEG) rhythms following brief, innocuous electrocutaneous stimulation were studied with respect to stimulus intensity and repetition and the size of corpus callosum (CC). METHODS: EEG was recorded using 82 closely spaced electrodes in 13 right-handed subjects. The subjects received 650 brief electrical stimuli to the right index finger at irregular intervals (6-12 s) in 5 blocks. The intensities of the stimuli varied randomly at 20, 30, 50, 65 and 80% of pain threshold. RESULTS: Mu- and beta-ERD of 0.3-0.6 s latency over the contra- and ipsilateral S1/M1 area was observed in all subjects. Post-stimulus beta-ERS over the contra- and ipsilateral frontal cortices with a peak latency of 0.6-0.8 s was found in 9 subjects. Stimuli presented in the second half of the experiment were followed by a smaller ipsilateral mu-ERD and smaller contra- and ipsilateral beta-ERD than stimuli applied in the first block. Mu- and beta-ERD and beta-ERS distinguished weak (20%) from intermediate and strong stimuli (>35%) but not the intermediate from strong stimuli. The amplitude of ipsilateral beta-ERS correlated positively with the size of intermediate truncus of CC (r(9)=0.71, P<0.05). In contrast, ipsilateral ERD showed no significant correlations with the size of CC. CONCLUSIONS: Habituation of ipsilateral mu-ERD and bilateral beta-ERD and beta-ERS suggests that these cortical responses are parts of the orienting response, and fail to disentangle fine intensity gradations. Ipsilateral beta-ERS appears to be mediated by the transcallosal fiber system.     

Non-coding RNA as a trigger of neuropathologic disorder phenotypes in transgenic Drosophila

At most, many protein-misfolding diseases develop as environmentally induced sporadic disorders. Recent studies indicate that the dynamic interplay between a wide repertoire of noncoding RNAs and the environment play an important role in brain development and pathogenesis of brain disorders. To elucidate this new issue, novel animal models which reproduce the most prominent disease manifestations are required. For this, transgenic Drosophila strains were constructed to express small highly structured, non-coding RNA under control of a heat shock promoter. Expression of the RNA induced formation of intracellular aggregates revealed by Thioflafin T in embryonic cell culture and Congo Red in the brain of transgenic flies. Also, this strongly perturbed the brain control of locomotion monitored by the parameters of sound production and memory retention of young 5-day-old males. This novel model demonstrates that expression of non-coding RNA alone is sufficient to trigger neuropathology.