Metabolic fate of 2,2-dimethylbutyryl moiety of simvastatin in rats: identification of metabolites by gas chromatography/mass spectrometry.

Metabolic pathways of simvastatin (MK-733), a lactone prodrug of an inhibitor of HMG-CoA reductase, were elucidated in male rats, using the [14C]-labelled compound. Evidence has been obtained for hydrolysis of simvastatin and its metabolites at their 2,2-dimethylbutyryl moieties. Metabolites identified in plasma were 2,2-dimethylbutyric acid (DMB), 2,2-dimethyl-3-hydroxybutyric acid (DMHB) and an open chain hydroxy acid of simvastatin: metabolites identified in urine were DMHB, a glucuronide and the glycine conjugate of DMB. They were characterized by gas chromatography/electron impact and chemical ionization mass spectrometry as phenacyl or pertrimethylsilylated derivatives. The structures of the metabolites and the aglycone of the glucuronide were confirmed as phenacyl esters by comparison of their chromatographic data and mass spectra with those of the phenacyl derivatives of authentic compounds.     

The CADO-E I type endometrial applicator for RALS therapy

A dual stainless steel applicator (CADO-E I type) was developed for intracavitary radiotherapy of endometrial carcinoma using remotely controlled afterloader (RALS). An inverted pear-shaped isodose curve was obtained by means of this metallic applicator and Co-60 source with a stepwise movement. Reference point X was defined as 2 cm below the fundus and 2 cm lateral to the center line of the uterus to specify the dose absorbed to the uterine corpus with our endometrial applicator. Since cancer residua resulting from cold spots in dose distribution were recognized at the uterine fundus by histopathological investigation of serial sections in the hysterectomy specimens, we intend to develop an applicator with three metallic tubes (CADO-E II type).     

Aortic pressure augmentation as a marker of cardiovascular risk in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is associated with increases in cardiovascular morbidity and mortality. Vascular changes in individuals with OSAS have not been fully elucidated, however. The possible impact of OSAS on the extent of aortic pressure augmentation (AG), an indicator of cardiovascular risk, was investigated. Forty-five consecutive male patients aged 35 to 78 years (56.0+/-9.6 years) who were referred to the sleep clinic of Nagoya University Hospital for screening and treatment of OSAS and 71 age-matched healthy men were enrolled in the study. AG was derived from the pressure waveform measured at the radial artery by applanation tonometry. The number of apnea and hypopnea episodes per hour (apnea-hypopnea index [AHI]) was determined by standard polysomnography. AG was significantly greater in OSAS patients than in controls (9.0+/-4.1 vs. 6.4+/-3.4 mmHg, p<0.001), and it was significantly reduced in 19 OSAS patients treated with continuous positive airway pressure. AG was also significantly correlated with the AHI (r=0.562, p<0.001) and age (r=0.356, p=0.016) but not with the serum concentrations of low and high density lipoprotein-cholesterol, triglyceride, or glycosylated hemoglobin. Stepwise multiple regression analysis revealed that the AHI was the most significant contributing factor to the increased AG in OSAS patients (beta=0.109, r=0.530, p<0.001). OSAS may thus have an adverse effect on vascular function that can be ameliorated by appropriate treatment.     

Detection of necrotic neural response in super‐acute cerebral ischemia using activity‐induced manganese‐enhanced (AIM) MRI

Immediate and certain determination of the treatable area is important for choosing risky treatments such as thrombolysis for brain ischemia, especially in the super‐acute phase. Although it has been suggested that the mismatch between regions displaying ‘large abnormal perfusion’ and ‘small abnormal diffusion’ indicates a treatable area on an MRI, it has also been reported that the mismatch region is an imperfect approximation of the treatable region named the ‘penumbra’. Manganese accumulation reflecting calcium influx into cells was reported previously in a middle cerebral artery occlusion (MCAO) model using activity‐induced manganese‐enhanced (AIM) MRI. However, in the super‐acute phase, there have been no reports about mismatches between areas showing changes to the apparent diffusion coefficient (ADC) and regions that are enhanced in AIM MRI. It is expected that the AIM signal can be enhanced immediately after cerebral ischemia in the necrotic core region due to calcium influx. In this study, a remote embolic rat model, created using titanium‐oxide macrospheres, was used to observe necrotic neural responses in the super‐acute phase after ischemia. In addition, images were evaluated by comparison between ADC, AIM MRI, and histology. The signal enhancement in AIM MRI was detected at 2 min after the cerebral infarction using a remote embolic method. The enhanced area on the AIM MRI was significantly smaller than that on the ADC map. The tissue degeneration highlighted by histological analysis corresponded more closely to the enhanced area on the AIM MRI than that on the ADC map. Thus, the manganese‐enhanced region in brain ischemia might indicate ‘necrotic’ irreversible tissue that underwent calcium influx. Copyright © 2009 John Wiley & Sons, Ltd.     

Human group IIA secretory phospholipase A2 induces neuronal cell death via apoptosis.

Expression of group IIA secretory phospholipase A2 (sPLA2-IIA) is documented in the cerebral cortex (CTX) after ischemia, suggesting that sPLA2-IIA is associated with neurodegeneration. However, how sPLA2-IIA is involved in the neurodegeneration remains obscure. To clarify the pathologic role of sPLA2-IIA, we examined its neurotoxicity in rats that had the middle cerebral artery occluded and in primary cultures of cortical neurons. After occlusion, sPLA2 activity was increased in the CTX. An sPLA2 inhibitor, indoxam, significantly ameliorated not only the elevated activity of the sPLA2 but also the neurodegeneration in the CTX. The neuroprotective effect of indoxam was observed even when it was administered after occlusion. In primary cultures, sPLA2-IIA caused marked neuronal cell death. Morphologic and ultrastructural characteristics of neuronal cell death by sPLA2-IIA were apoptotic, as evidenced by condensed chromatin and fragmented DNA. Before apoptosis, sPLA2-IIA liberated arachidonic acid (AA) and generated prostaglandin D2 (PGD2), an AA metabolite, from neurons. Indoxam significantly suppressed not only AA release, but also PGD2 generation. Indoxam prevented neurons from sPLA2-IIA-induced neuronal cell death. The neuroprotective effect of indoxam was observed even when it was administered after sPLA2-IIA treatment. Furthermore, a cyclooxygenase-2 inhibitor significantly prevented neurons from sPLA2-IIA-induced PGD2 generation and neuronal cell death. In conclusion, sPLA2-IIA induces neuronal cell death via apoptosis, which might be associated with AA metabolites, especially PGD2. Furthermore, sPLA2 contributes to neurodegeneration in the ischemic brain, highlighting the therapeutic potential of sPLA2-IIA inhibitors for stroke.     

Three-dimensional sonographic assessment of fetal behavior in the early second trimester of pregnancy.

OBJECTIVE: To evaluate the fetal behavior pattern in the early second trimester of pregnancy by use of specially developed abdominal dynamic three-dimensional sonography. METHODS: Dynamic three-dimensional sonographic examinations were performed on 11 healthy pregnant women at 14 to 18 weeks of gestation. This imaging system provided continuous three-dimensional sonographic images every 1 to 2 seconds. Fetal movements were recorded continuously for 60 minutes in each fetus. The rate of occurrence of head, mouth, arm, trunk, and leg movements was evaluated. All fetal behavioral patterns were observed during the period studied. RESULTS: The active phase (time with fetal movements) was 59.4%, and the resting phase was 40.6%. The most active fetal behavior pattern was an arm movement, whereas the least was a mouth movement. Moreover, each fetal movement was synchronized and harmonized with other fetal movements (a few movement patterns were found to be generated simultaneously). CONCLUSIONS: Dynamic three-dimensional sonography provides a novel means for evaluation of fetal behavior in the early second trimester of pregnancy. These results suggest that dynamic three-dimensional sonography may be an important modality in future early fetal behavior research and in evaluation of early fetal well-being.     

Chronic hypoxia accelerates the progression of atherosclerosis in apolipoprotein E-knockout mice.

The aim of this study was to investigate the effect of chronic hypoxia on the development and progression of atherosclerosis in apolipoprotein E-knockout (apoE-KO) mice. Male and female apoE-KO mice (6 weeks old) and age- and sex-matched wild-type mice were kept under hypoxic conditions (10.0 +/- 0.5% O2) in a gas chamber or in room air for 3 weeks. Aortic atherosclerotic plaque was not observed in wild-type mice under normoxic or hypoxic conditions. In the apoE-KO mice, however, hypoxia induced proliferation of smooth muscle cells and plaque formation in the aorta, which were not observed under normoxic conditions. Although sexual dimorphism of the response to hypoxia was not observed, these hypoxia-induced atherogenic changes were accompanied by a significant increase of plasma low density lipoprotein (LDL) cholesterol and NADPH-dependent vascular superoxide (O2-) production. Furthermore, matrix metalloproteinase (MMP)-9 was activated in the aorta of apoE-KO mice. In conclusion, chronic hypoxia accelerated the development of atherosclerosis in apoE-KO mice, along with increased O2- production and activated MMP-9 in the aorta.     

Quantification of cell kinetic characteristics using flow cytometric measurements of deoxyribonucleic acid and bromodeoxyuridine for bladder cancer

A total of 56 human bladder tumors that were histologically proved to be transitional cell carcinoma was analyzed by simultaneous flow cytometric 2-color measurements of deoxyribonucleic acid (DNA) and bromodeoxyuridine. Bromodeoxyuridine in vitro labeling was performed by sample incubation with bromodeoxyuridine under high atmospheric pressure oxygen. Grade 1 tumors showed 33.3% aneuploidy with a mean bromodeoxyuridine positive stained ratio (labeling index) of 5.1 +/- 3.4%. Grade 2 tumors featured 51.7% aneuploidy with a mean labeling index of 8.9 +/- 7.7%. On the other hand, a markedly increased labeling index of 15.2 +/- 8.2% with aneuploidy was observed in all but 1 grade 3 tumors. When DNA ploidy and labeling indexes were compared according to the presence or absence of muscular invasion of tumors, all 16 muscle invasive tumors showed aneuploidy (mean labeling index 18.7 +/- 8.0%), while 17 of 40 nonmuscle invasive tumors showed aneuploidy (mean labeling index 8.6 +/- 5.4%). This labeling index difference was statistically significant (p less than 0.01). These results indicate that bromodeoxyuridine/DNA 2-color flow cytometry may provide an objective parameter for quantification of the malignant potential of bladder cancers.