Solitary Osteochondroma of the Skull Base: A Case Report and Literature Review

We report a case of an osteochondroma in the posterior clinoid process that occurred in a 43-year-old man with trochlear nerve palsy. Although the potential preoperative diagnoses based on computed tomography and magnetic resonance imaging included other intracranial tumors such as calcified meningioma, thallium-201 single-photon emission computed tomography effectively differentiated osteochondroma from those possibilities. Via an orbitozygomatic approach, a subtotal resection was achieved with a good relief of symptoms. Twenty-two cases of solitary osteochondromas in the skull base have been reported that have demonstrated little risk of recurrence or malignant transformation. However, surgery for skull base osteochondromas does carry a significant risk with a reported mortality > 10%. Although some previous reports advocate complete resection as the only curative method for skull base osteochondromas, the risks of total resection should be weighed against the chance for recurrence; our review of the literature demonstrated a relatively high mortality and an extremely low incidence of recurrence.

Accurate standard hydrogen electrode potential and applications to the redox potentials of vitamin C and NAD/NADH

We computationally evaluated the standard hydrogen electrode (SHE) potential in aqueous phase and the Gibbs energy of a proton from the experimental pKa values of alcohol molecules. From the "golden standard" CCSD(T)/aug-cc-pVTZ level calculation, we estimated the SHE potential as 4.48 V, which is very close to the IUPAC-recommended experimental value of 4.44 V. As applications to the Gaussian-3 (G3) methods, which also reproduce the "golden standard" level calculations, we computed various pKa values and redox potentials for a vitamin series. For vitamin C, we support the experimental result of +0.35 V and predict the pKa value of d-ascorbic acid to be 3.7-3.9. Using a model molecule for nicotinamide adenine dinucleotide (NAD), we reproduced the redox potential and determined the order of the proton/electron addition, based on both the proton affinity and redox potential.

DFT and TD-DFT studies of electronic structures and one-electron excitation states of a cyanide-bridged molecular square complex

The electronic structures and physical properties of [Co₂Fe₂(CN)₆(tp*)₂(dtbbpy)₄](PF₆)₂·2MeOH are investigated by DFT and TD-DFT calculations.

Bazedoxifene blocks AGEs-RAGE-induced superoxide generation and MCP-1 level in endothelial cells

Advanced glycation endproducts (AGEs) and their receptor (RAGE) play a role in vascular complications in diabetes. We have previously shown that 17β-estradiol at 10 nmol/l, a nearly identical plasma concentration to that during mid-pregnancy, up-regulates RAGE expression in endothelial cells. The finding might suggest the involvement of 17β-estradiol in the deterioration of vascular complications in diabetes during pregnancy. However, the effects of the selective estrogen receptor modulator, bazedoxifene, on oxidative and inflammatory reactions in AGEs-exposed endothelial cells remain unknown. In this study, we addressed the issue. Ten nmol/l 17β-estradiol increased RAGE and monocyte chemoattractant protein-1 (MCP-1) gene and protein expression in human umbilical vein endothelial cells (HUVECs), both of which were blocked by 10 nmol/l bazedoxifene. Bazedoxifene at 10 nmol/l also significantly inhibited the AGEs-induced superoxide generation, RAGE and MCP-1 gene and protein expression in HUVECs. The present study suggests that blockade of the AGEs-RAGE axis by bazedoxifene might be a novel therapeutic target for preventing vascular damage in diabetes, especially in postmenopausal women.

A Case of the Internal Carotid Artery-Posterior Communicating Artery Aneurysm Mimicking Tolosa-Hunt Syndrome

A 53-year-old woman experienced a right retrobulbar pain followed by ipsilateral extraocular palsies in all directions without dilated pupils or ptosis. Because a plain head computed tomography (CT) scan obtained on her initial visit showed no abnormal findings, such as subarachnoid hemorrhage or a giant cavernous aneurysm, her condition was provisionally diagnosed as Tolosa–Hunt syndrome and elective magnetic resonance (MR) imaging was scheduled. The day after her initial visit, however, she suddenly developed complete ptosis and a dilated pupil on the right side. Emergency MR imaging and angiography revealed a clover leaf-shaped aneurysm projecting to the cavernous sinus at the junction of the internal carotid artery and the posterior communicating artery. Her condition was diagnosed as impending rupture of the aneurysm, and she underwent emergency open surgery. Her symptoms completely resolved within the following 2 weeks. Our case demonstrated that a medium-sized internal carotid artery–posterior communicating artery aneurysm can cause simultaneous oculomotor and abducens nerve palsies with retrobulbar pain if the shape of the aneurysm is complicated. Although these symptoms are very similar to those of Tolosa–Hunt syndrome, we believe that prompt radiological examinations such as MR or 3D CT angiography should be performed to prevent subsequent rupture of the aneurysm.

Effects of supplemental oxygen on urinary 8-hydroxy-2'-deoxyguanosine levels in extremely low birth weight infants

As the effects of supplementary oxygen on urinary excretion of 8-hydroxy-2'-deoxyguanosine (8-OHdG) are poorly understood, urinary 8-OHdG levels (ng/mg creatinine) were determined longitudinally on the postnatal day (PND) 1, 3, and 30 in 16 neonates with birth weight < 1000 g. No supplementary oxygen was required in 9 neonates during the first 24 h of life. Urinary 8-OHdG level on PND 1 was inversely correlated with birth weight in these 9 neonates (P = 0.0323) and was higher in four with birth weight < 750 g than five with birth weight > 750 g (41.0 ± 6.9 vs. 5.6 ± 2.7, respectively, P = 0.0200). Median urinary 8-OHdG on PND 1 of these 9 neonates was significantly lower than that of 7 neonates with oxygen (9.3 vs. 60.2, respectively), although there were no significant differences in clinical background, such as birth weight, between the two groups. Five of the 9 did not require supplemental oxygen at all during the first 30 days of life. Median urinary 8-OHdG levels were consistently significantly lower in the 5 neonates than in 11 neonates with oxygen transiently or persistently (9.3 vs. 54.6, 19.1 vs. 61.4, and 28.3 vs. 145 on PND 1, 3, and 30, respectively), although there were no differences in clinical background, such as birth weight, between the two groups. Urinary 8-OHdG on PND 30 was significantly positively correlated with supplemental oxygen dose on PND 30 (P < 0.0001), but not with birth weight in the 16 neonates. These results suggest that higher supplemental oxygen tension caused higher urinary 8-OHdG in this population.

Linagliptin blocks renal damage in type 1 diabetic rats by suppressing advanced glycation end products-receptor axis

Advanced glycation end products (AGEs) and their receptor (RAGE) play a role in diabetic nephropathy. We have recently found that linagliptin, an inhibitor of dipeptidyl peptidase-4 (DPP-4) suppresses the AGE-induced oxidative stress generation and intercellular adhesion molecule-1 (ICAM-1) gene expression in endothelial cells. However, whether linagliptin could have beneficial effects on experimental diabetic nephropathy in a glucose-lowering independent manner remains unknown. To address the issue, this study examined the effects of linagliptin on renal damage in streptozotocin-induced diabetic rats. Serum levels of DPP-4 were significantly elevated in diabetic rats compared with control rats. Although linagliptin treatment for 2 weeks did not improve hyperglycemia in diabetic rats, linagliptin significantly reduced AGEs levels, RAGE gene expression, and 8-hydroxy-2'-deoxyguanosine, a marker of oxidative stress in the kidney of diabetic rats. Furthermore, linagliptin significantly reduced albuminuria, renal ICAM-1 mRNA levels, and lymphocyte infiltration into the glomeruli of diabetic rats. Our present study suggests that linagliptin could exert beneficial effects on diabetic nephropathy partly by blocking the AGE-RAGE-evoked oxidative stress generation in the kidney of streptozotocin-induced diabetic rats. Inhibition of DPP-4 by linagliptin might be a promising strategy for the treatment of diabetic nephropathy.

Vitamin C nutrition in cattle

Domestic animals, including ruminants, can synthesize vitamin C (VC) in their liver; as such, the dietary requirement for VC has not been confirmed in these animals. The adequacy of VC has been evaluated by quantifying VC levels in plasma, but the reported values in bovine plasma have been widely variable. Plasma VC concentration is decreased by heat stress, hepatic lesions, fattening, and infectious diseases such as mastitis in cattle. Therefore, VC supplementation is potentially beneficial for cattle with low plasma VC concentration. This review discusses the methods for determination of plasma VC concentration in cattle, VC nutrition, and the efficacy of VC supplementation in calves, dairy cattle, and beef cattle. Additionally I propose a reference range for plasma VC concentration in Japanese Black cattle.

Olmesartan blocks advanced glycation end products-induced vcam-1 gene expression in mesangial cells by restoring Angiotensin-converting enzyme 2 level

Advanced glycation end products (AGEs) and their receptor (RAGE) system are involved in diabetic nephropathy. Angiotensin-converting enzyme 2 (ACE 2) plays a protective role against cardiovascular and renal injury by stimulating the production of angiotensin-(1-7) [Ang-(1-7)], an antagonist of angiotensin II (Ang II). However, effects of the AGEs-RAGE axis on ACE 2 expression in mesangial cells remain unknown. We examined here the role of ACE 2 in the AGEs-RAGE-induced mesangial cell damage and investigated whether olmesartan, one of the Ang II type 1 receptor blockers (ARB), prevented the deleterious effects of AGEs via restoration of ACE 2 and Ang-(1-7) level. AGEs significantly increased superoxide generation, upregulated RAGE mRNA level, and decreased ACE 2 gene expression and Ang-(1-7) production in mesangial cells, all of which were blocked by olmesartan, but not by a different type of ARB, azilsartan. An antioxidant, N-acetylcysteine or RAGE-antibodies also restored the decrease in ACE 2 mRNA level in AGEs-exposed mesangial cells. Moreover, olmesartan, but not azilsartan completely inhibited the AGEs-induced increase in vascular cell adhesion molecule-1 (VCAM-1) mRNA level in mesangial cells, which was abolished by the treatment with A-779, an antagonist of Ang-(1-7) receptor, Mas receptor. Our present study suggests that olmesartan could block the AGEs-induced VCAM-1 gene induction in mesangial cells by restoring the downregulated ACE 2 levels and subsequently stimulating the Ang-(1-7)-Mas receptor axis. Restoration of ACE 2 levels and blockade of renin-angiotensin system by olmesartan might be a promising strategy for the treatment of diabetic nephropathy.

Molecular Phylogenetic Diversity of the Bacterial Community in the Gut of the TermiteCoptotermes formosanus

The phylogenetic diversity of the bacterial community in the gut of the termite Coptotermes formosanus was investigated using a 16S rRNA gene clone library constructed by PCR. After screening by restriction fragment length polymorphism (RFLP) analysis, 49 out of 261 clones with unique RFLP patterns were sequenced and phylogenetically analyzed. Many of the clones (94%) were derived from Bacteroidales, Spirochaetes, and low G + C content gram-positive bacteria consisting of Clostridiales, Mycoplasmatales, Bacillales, and Lactobacillales. In addition, a few clones derived from Actinobacteria, Proteobacteria, Planctomycetes, Verrucomicrobia, and the candidate phylum "Synergistes" were also found. The most frequently identified RFLP type, BCf1-03, was assigned to the order Bacteroideales, and it constituted about 70% of the analyzed clones. The phylogenetic analysis revealed that the representative clones found in this study tended to form some clusters with the sequences cloned from the termite gut in several other studies, suggesting the existence of termite-specific bacterial lineages.

Impact of assimilated and interactive aerosol on tropical cyclogenesis

This article investigates the impact of Saharan dust on the development of tropical cyclones in the Atlantic. A global data assimilation and forecast system, the NASA GEOS-5, is used to assimilate all satellite and conventional data sets used operationally for numerical weather prediction. In addition, this new GEOS-5 version includes assimilation of aerosol optical depth from the Moderate Resolution Imaging Spectroradiometer. The analysis so obtained comprises atmospheric quantities and a realistic 3-D aerosol and cloud distribution, consistent with the meteorology and validated against Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation and CloudSat data. These improved analyses are used to initialize GEOS-5 forecasts, explicitly accounting for aerosol direct radiative effects and their impact on the atmospheric dynamics. Parallel simulations with/without aerosol radiative effects show that effects of dust on static stability increase with time, becoming highly significant after day 5 and producing an environment less favorable to tropical cyclogenesis.

Nylon-Oligomer Hydrolase Promoting Cleavage Reactions in Unnatural Amide Compounds

The active site of 6-aminohexanoate-dimer hydrolase, a nylon-6 byproduct-degrading enzyme with a β-lactamase fold, possesses a Ser112/Lys115/Tyr215 catalytic triad similar to the one of penicillin-recognizing family of serine-reactive hydrolases but includes a unique Tyr170 residue. By using a reactive quantum mechanics/molecular mechanics (QM/MM) approach, we work out its catalytic mechanism and related functional/structural specificities. At variance with other peptidases, we show that the involvement of Tyr170 in the enzyme-substrate interactions is responsible for a structural variation in the substrate-binding state. The acylation via a tetrahedral intermediate is the rate-limiting step, with a free-energy barrier of ∼21 kcal/mol, driven by the catalytic triad Ser112, Lys115, and Tyr215, acting as a nucleophile, general base, and general acid, respectively. The functional interaction of Tyr170 with this triad leads to an efficient disruption of the tetrahedral intermediate, promoting a conformational change of the substrate favorable for proton donation from the general acid.

[A review of treatment outcomes for intracranial abscess at our institution]

BACKGROUND

Intracranial abscesses account for 2% of the intracranial mass even in advanced countries. Because of the variety of causative organisms and symptoms, a standard treatment for intracranial abscess has not yet been established.

MATERIALS AND METHODS

We retrospectively reviewed the treatment outcomes for intracranial brain abscess and subdural abscess to assess the risk factors for poor prognosis and problems related to treatment.

RESULTS

In total, 28 patients were included in this study. Preceding craniocervical infections were found in 35.7% of patients. In 39.3% of patients, causative organisms were not identified. The treatment outcome evaluated using the modified Rankin Scale was 0 in 17 patients, 1 in 1 patient, 2 in 2 patients, 4 in 3 patients, 5 in 1 patient, and 6 in 4 patients. All mortality was noted in patients older than 60 years. Advanced age and the development of ventriculitis were significantly associated with poor outcome, i.e., a modified Rankin Scale score of 4 or worse. In contrast, the presence of fever or headache as initial symptoms, severity of neurological deficit, location of the abscess, and lack of identification of causative organism were not related to poor outcome. Compared with our previous treatment results, diffusion-weighted MR imaging has significantly contributed to the improvement of outcomes.

CONCLUSION

Early administration of antibiotic therapy based on MR findings was critical in obtaining a good outcome in the treatment of brain abscess. Based on our experience, treatment should be continued, even for patients in a critical condition.