Disseminated histiocytic sarcoma in a squirrel monkey (Saimiri sciureus).

A 14-years-old squirrel monkey was euthanized due to weakness. Histopathological examination revealed multifocal growth of oval cells with severe atypia in the liver, spleen, and bone marrow. The neoplastic cells were positive for histiocytic markers (Iba1, HLA-DR, CD204). This is the fourth case of histiocytic sarcoma in non-human primates.

Predictive Factors for Successful Treatment of Deep Incisional Surgical Site Infections following Instrumented Spinal Surgeries: Retrospective Review of 1832 Cases.

BACKGROUND: Surgical site infection (SSI) is a major complication in spinal instrumentation that is often difficult to treat. The purpose of this study was to identify and determine prognostic indicators for successful treatment of spine instrumentation SSI. METHODS: Retrospectively, spine surgery cases were examined on SSI diagnosis. Post-instrumentation SSI patients were categorized as "Successful" if SSI subsided after single debridement. Patients in whom SSI did not subsided and/or required removal of instrumentation were classified as "Challenging". We investigated the relation of treatment outcomes to patients and treatment factors. RESULTS: A total of 1832 spinal instrumentation cases were recognized with 44 (2.40%) SSI cases. White blood cell count, C-reactive protein (CRP) levels, causative bacteria (i.e., S. Aureus or MRSA), trauma injury, and early-stage antimicrobial agent sensitivity correlated with treatment prognosis. Multivariate analysis highlighted CRP levels and applying early-stage sensitive antibiotics as potential impactful predictive factors for successful treatment. CONCLUSIONS: Our results demonstrated that early selection of sensitive antimicrobial agents is critical and emphasizes the potential for early-stage classification methods such as Gram staining. Additionally, S. Aureus and MRSA SSI formed significantly more challenging infections to treat, thus requiring consideration when deciding on instrumentation retention. These factors offer promising aspects for further large-scale studies.

Antiadipogenic Effects of Different Molecular Forms of Conjugated Linoleic Acid on 3T3-L1 Cells: Comparison between Free Fatty Acid and Phosphatidylcholine Forms.

The antiadipogenic activity of conjugated linoleic acids (CLA) in the form of phosphatidylcholine-bound (CLA-PC) or free fatty acids (FFA; CLA-FFA) was evaluated using 3T3-L1 adipocytes. Phosphatidylcholine from soya (soy-PC) was used as the comparison of PC form. Both the lipid accumulation and activity of glycerol-3-phosphate dehydrogenase were measured to determine lipogenesis, whereas the glycerol content was measured to evaluate lipolysis. The CLA uptake also measured to find out the utilization of CLA by the cells. As a results, lipid accumulation in 3T3-L1 adipocytes was inhibited in a dose-dependent manner following treatment with CLA-PC (50-400 µM). Both CLA-PC and soy-PC significantly suppressed lipid accumulation compared with CLA-FFA, even though the amount of CLA in CLA-PC was a half than CLA-FFA. The CLA uptake of PC form was superior to FFA form, however, no difference was noted between CLA-PC and soy-PC. These forms exerted their antiadipogenic activity via the suppression of lipogenesis, and not by increasing lipolysis. Short-term treatment, especially in the middle stage of differentiation, was more effective than long-term treatment; especially for CLA-FFA. The antiadipogenic effect of CLA-PC was partially attributed to the chemical structure of the PC molecule. These results provide important information for the utilization of physiologically functional fatty acids and particularly CLA in the food and medical fields.

Facile Preparation of Purified Sinapate Ethyl Ester from Rapeseed Meal Extracts Using Cation-exchange Resin in Dual Role as Adsorber and Catalyst.

In this study, cation-exchange resin was used to prepare an esterified antioxidant, sinapate ethyl ester (SE), using ethanolic extracts from rapeseed. A concentration of sinapic acid using the cation-exchange resin in 80% ethanol (aq) and subsequent interesterification of the extract in ethanol using the same resin afforded a product with a purity of 64 wt% and 100% of SE yield. Moreover, after purification using preparative thin-layer chromatography, almost 100 wt% purity was obtained. In an auto-oxidation test, purified SE conferred a much higher antioxidative effect on the bulk oil, emphasising the effectiveness of the protocol using cation-exchange resin for the purification.

The Enzymatic Preparation of Human Milk Fat Substitute Intermediate Rich in Palmitic Acid at sn-2 Position and Low-Unsaturated Fatty Acids at sn-1(3) Positions from Palm Oil Substrate.

The lipid products that consist of structured lipids rich in palmitic acid (16:0) at the sn-2 position of triacylglycerol (TAG) and rich in low-unsaturated fatty acids (FAs) (LUFAs), such as oleic acid; 18:1 and linoleic acid; 18:2 at the sn-1(3) positions, are useful intermediates for manufacturing human milk fat substitute (HMFS), which contains functional lipid components. In this study, the HMFS intermediate (HMFS-IM) was enzymatically prepared from palm oil without using other oil sources. First, the amount of 16:0 at the sn-2 position of TAG substrate was enhanced from 18.9% to more 34.5% via a random esterification reaction using a non-stereospecific lipase, Novozym® 435, to produce a random-palm substrate. Consequently, 2-monoacylglycerol (2-MAG) rich in 16:0 at the sn-2 position over 88%, together with the FA ethyl ester substrates rich in LUFAs, such as 18:1-Et and 18:2-Et above 93.5% was prepared through ethanolysis reaction using the same lipase from the random-palm substrate and by purification with urea complexation, respectively. As the preferred modified method, a continuous use of the same lipase to these reactions were achieved while reducing the usage of enzyme to half. Finally, an HMFS-IM rich in 16:0 at the sn-2 position more than 60% and LUFA at sn-1(3) positions was prepared using these palm oil-based products, including random-palm, palm-Et, and 2-MAG, via the interesterification reaction using a 1,3-stereospecific lipase, Lipozyme® RM-IM. Thus, HMFS-IM was successfully prepared by palm oil materials with a 65 wt% usage ratio. The concept described in this study will be useful for HMFS manufacturing from a single natural oil substrate, which is not initially rich in 16:0 at the sn-2 position.

Highly efficient preparation of 1-lysophosphatidylcholine via high proportion of Novozym® 435 (lipase B from Candida antarctica)-catalyzed ethanolysis.

Efficient preparation methods for 1-lysophosphatidylcholine (1-LPC), a physiologically important compound, are lacking. Here, we established a method for 1-LPC preparation via Novozym® 435 (a lipase B from Candida antarctica)-catalyzed ethanolysis. Novozym® 435 showed sn-1 regiospecificity to phosphatidylcholine, although it does not exhibit regiospecificity to triacylglycerol. In particular, quantitative 1-LPC yields (96.5 ±â€¯0.2 mol%) were reliably obtained in the presence of Novozym® 435 (100 wt% of PC), 97 % ethanol, in 72 h at 40 °C. During the reaction, acyl migration from 1-LPC to 2-LPC was rare. This novel synthetic method is expected to expand the practical applications of 1-LPC.

Enzymatic Preparation and Oxidative Stability of Human Milk Fat Substitute Containing Polyunsaturated Fatty Acid Located at sn-2 Position.

The development of human milk fat substitutes (HMFSs), rich in palmitic acid (16:0) at the sn-2 position of triacylglycerol (TAG) and rich in unsaturated fatty acids (FAs) (oleic acid, 18:1 and linoleic acid, 18:2) at the sn-1(3) positions, has gained popularity. In this study, HMFSs containing polyunsaturated fatty acids (PUFAs) predominantly at the sn-2 position were prepared, and their oxidation stabilities were compared. First, a non-PUFA-containing HMFS (NP-HMFS) was produced by enzymatic reactions using Novozyme® 435 and Lipozyme® RM-IM as the enzymes and lard as the raw material. Second, HMFSs, containing 10 % PUFA at the sn-2 or sn-1(3) position, were individually prepared by enzymatic reactions using lard and fish oil as raw materials. Here, sn-2-PUFA-monoacylglycerol (MAG) was extracted from the reaction solution using a mixture of hexane and ethanol/water (70:30, v/v) to produce high-purity sn-2-PUFA-MAG with 78.1 % yield. For the PUFA-containing HMFS substrates, comparable oxidation stability was confirmed by an auto-oxidation test. Finally, HMFSs containing 10 % or 2 % sn-1,3-18:1-sn-2-PUFA-TAG species were prepared by enzymatic reactions and subsequent physical blending. The oxidative stability of sn-1,3-18:1-sn-2-PUFA-HMFS was two-fold higher than that of 1/2/3-PUFA-HMFS in which each PUFA was located without stereospecific limitations in TAG. The removal of PUFA-TAG molecular species with higher concentrations of unsaturated units had a significant effect. In addition, the oxidation stability increased with the addition of tocopherol as an antioxidant. Thus, the combined use of two strategies, that is, the removal of PUFA-TAG molecular species with high concentrations of unsaturated units and the addition of antioxidants, would provide a PUFA-containing HMFS substrate with high oxidative stability.

Effect of Molecular Form of Conjugated Linoleic Acid on Oxidative Stability : Comparison of Triacylglycerol and Phosphatidylcholine Form.

The health benefits of conjugated linoleic acid (CLA), a functional lipid with anti-cancer, anti-obesity, and hypotensive activity, have garnered increasing attention. The current study was conducted to determine the oxidative stability of CLA in the form of triacylglycerol (CLA-TAG) and phosphatidylcholine (CLA-PC) at the sn-2 position. Oxidation was performed at 30°C or 40°C in the dark. Hydroperoxides, as the primary oxidation products, were analyzed using diphenyl-1-pyrenylphosphine. Thiobarbituric acid reactive substances (TBARS) and volatile compounds were monitored as secondary oxidation products. The results suggest that CLA-PC was more stable against oxidation than CLA-TAG from the perspective of suppression of the generation of hydroperoxides and TBARS. However, CLA-PC produced more volatile compounds than CLA-TAG. We suggest that choline was released during the oxidation of CLA-PC, and acted as an antioxidant. The ensuing reaction between choline and hydroperoxide induced the generation of volatile compounds such as pentanal, hexanal, and heptanal.

A Patient with Pediatric Septic Arthritis of the Hip Complicated with Osteomyelitis Responds to Clindamycin.

A 5-year-old girl was referred to our institution with complaints of right hip pain and fever (39.0°C); blood tests and magnetic resonance imaging (MRI) were performed. Blood biochemical results revealed a high inflammatory reaction. MRI results revealed inflammation in the hip joint. She was diagnosed with pediatric septic arthritis of the hip, which required arthrotomy and lavage drainage. Treatment with intravenous vancomycin was initiated on the assumption that the causative bacterial species was Staphylococcus aureus. However, Group A Streptococcus pyogenes (GAS) was subsequently isolated from an intraoperative sample, and the antimicrobial agent was switched to aminobenzylpenicillin (ABPC). Clindamycin (CLDM) was added to the treatment regimen 14 days after surgery as MRI indicated the development and spread of osteomyelitis. Three months post-surgery, MRI findings indicated that the osteomyelitis had resolved and antimicrobial therapy was discontinued. To prevent the spread of osteomyelitis, a combination of CLDM and ABPC should be considered at an early stage, particularly in pediatric patients with GAS-induced septic arthritis.

Preparation of Chiral Triacylglycerols, sn-POO and sn-OOP, via Lipase-mediated Acidolysis Reaction.

It is well known that lipases are useful tools for preparing various structured triacylglycerols (TAGs). However, the lipase-mediated preparation of chiral TAGs has never been reported. This study aimed to prepare chiral TAGs (viz., 1-palmitoyl-2,3-dioleoyl-sn-glycerol (sn-POO) or 1,2-dioleoyl-3-palmitoyl-sn-glycerol (sn-OOP)) via lipase mediated acidolysis, using triolein (TO) and palmitic acid (P) as substrates. Three commercially available lipases (viz., Lipozyme RM-IM®, Lipozyme TL-IM®, and Lipase OF®) were used. Lipozyme RM-IM® resulted in an increase 1P-2O (sn-POO + sn-OOP + 1,3-dioleoyl-2-palmitoyl-sn-glycerol) content with reaction time, which plateaued at 2~24 h (max. yield 47.1% at 4 h). The highest sn-POO/sn-OOP ratio of ca. 9 was obtained at 0.25 h, and the rate got close to 1 with reaction time (sn-POO/sn-OOP = 1.3 at 24 h). Lipozyme TL-IM® resulted in a lower 1P-2O synthesis rate than Lipozyme RM-IM®, where its highest sn-POO/sn-OOP ratio of ca. 2 was obtained at 0.25 h and did not vary much further with reaction time. In the case of Lipase OF®, its reaction rate for 1P-2O synthesis was lower than that of the other two lipases, and the highest sn-POO/sn-OOP ratio of ca. 1.4 was obtained at 0.5 h, reaching closer to 1 with a longer reaction time. Reaction solvents (viz., hexane, acetone, and benzene) also affected the 1P-2O preparation, where the highest 1P-2O content was obtained with the solvent-free system. Furthermore, the solvent-free system showed a higher reaction rate for 1P-2O synthesis than did the hexane system, with no effect on chiral specificity of the lipase for the TAG molecules. These results suggested that among three types of commercial lipase, Lipozyme RM-IM® is the most useful for the preparation of chiral TAGs by acidolysis reaction.

Effects of Triacylglycerol Molecular Species on the Oxidation Behavior of Oils Containing α-Linolenic Acid.

Two kinds of oils, pure perilla oil and a blend of perilla oil with palm oil, and their enzymatically interesterified oils having the same fatty acid compositions but with different compositions of triacylglycerol (TAG) species, were studied. In particular, the effects of TAG molecular species on the oxidation resistance of oils containing α-linolenic acid (Ln) were investigated. The content of TAG binding to three Ln molecules (3Ln-TAG) was found to be different between perilla oil (38.7%) and the interesterified oils (14.5-28.9%) , which were generated using Lipozyme RM-IM(®) (regiospecificity: sn-1, 3 positional). Oils with lower 3Ln-TAG contents were more stable to oxidation as determined by the conductometric determination method (CDM; 90°C, 20 L/h) than oils with higher 3Ln-TAG contents. This result was also supported by heating oxidation tests (180°C, 7 h) using the interesterified blended oils; the residual ratio of Ln-TAGs in the oils was found to be in the order of 3Ln-TAG<2Ln-TAG<1Ln-TAG. Oxidation stability of Lipase OF(®) (regiospecificity: random)-interesterified blended oils also improved on lowering the 3Ln-TAG content. In addition, the oxidation stabilities of Lipozyme RM-IM(®)-interesterified oils were slightly higher than those of the Lipase OF(®)-interesterified oils. We found that the content of 3Ln-TAG was almost the same in both oils, and the content of unsaturated fatty acid at the sn-1, 3 positions of Lipase OF(®)-interesterified oils was higher than that of Lipozyme RM-IM(®)-interesterified oils. These results indicate that oxidation stabilities of oils containing TAG with unsaturated fatty acid such as Ln at sn-2 position were higher than those having unsaturated fatty acids at the sn-1, 3 positions. From these results, the oxidation stability of oils rich in Ln, such as perilla oil and linseed oil, can be improved not only by decreasing 3Ln-TAG but also by enzymatically reducing the unsaturated fatty acid content at the sn-1, 3 positions.

Enzymatic preparation of human milk fat substitutes and their oxidation stability.

Human milk fat substitutes (HMFSs), rich in palmitic acid (P) at the sn-2 position of triacylglycerol (TAG), were prepared from lard via Novozym435(®)- and Lipozyme RM-IM(®)-mediated two-step reactions. First, 2-palmitoyl monoacylglycerol (2-P-MAG, 90% purity) was prepared via Novozym435(®)mediated ethanolysis of lard. Then, 2-P-MAG, oleic acid (O), linoleic acid (L), and lard were dissolved in hexane and subjected to a Lipozyme RM-IM(®)-mediated reaction for HMFS preparation. The effect of the amount of 2-P-MAG and fatty acids (O and L) in HMFS preparation were investigated. Under the optimum reaction conditions: 7 mmol of lard, 3.0 mmol of 2-P-MAG, 5.2 mmol of O, 3.5 mmol of L, 10 mL of hexane, 10 wt% of Lipozyme RM-IMR(®) (against the total weight of substrates), 550 rpm, 37°C and 6 h, a HMFS with total fatty acid composition and P content at the sn-2 position of TAG similar to that of human milk fat was prepared. In the same way, a HMFS having polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (PUFA-HMFS) was prepared. The HMFS and PUFA-HMFS prepared in this study, as well as fats extracted from commercially available powdered milk for infants (FPM) were evaluated for their oxidation stability by an auto-oxidation test. The test showed HMFS and PUFA-HMFS to possess greater oxidation stability than that the FPMs. These results indicated that the HMFS and PUFA-HMFS prepared in this study have value as potential ingredients for powdered milk.

Lipase-catalyzed preparation of phospholipids containing n-3 polyunsaturated fatty acids from soy phospholipids.

To utilize n-3 polyunsaturated fatty acid (PUFA) for a wide range of applications, we prepared phospholipids (PLs) containing PUFAs as constituent fatty acids (PUFA-PLs) via commercially available lipase OF-mediated transacylation with PL from soy (Soy-PL) and ethyl ester of PUFA (PUFA-Et). In a preliminary study to evaluate PUFA-incorporation (wt%) on phosphatidylcholine (PC), we observed that dehydration of Soy-PL is critical. PUFA-incorporation in PLs increased with acyl ratio and time. Finally, maximum PUFA-incorporation (47.1 ± 2.1 wt%) was obtained using the following reaction conditions: 2.0 mmol of Soy-PL, a PUFA-Et/Soy-PL acyl ratio of 7, 13 mL of hexane, 2.2 × 10(5) U of lipase OF, 500 rpm of agitation, a temperature of 37°C, and 72 h of reaction time. The analysis of fatty acid composition at the sn-2 position of obtained PL revealed that PUFAs incorporated into Soy-PL localized to the sn-2 position of the PL molecule in spite of using lipase OF whose positional specificity is random for triacylglycerol.

Effects of antioxidants and additional emulsifiers on the stability of emulsified milk fat in the photo/radical oxidation system.

The effects of antioxidants on the oxidative deterioration of emulsified oils and fats differ depending on the oxidation conditions, oils and fats used, and type of emulsifier. In this study, milk fat was emulsified to obtain water-oil (O/W) emulsion using Tween20 as emulsifier. The antioxidative effects of several antioxidants with various lipophilic properties, such as δ-tocopherol (Toc), epigallocatechin gallate (EGCg), quercetin (Qu), green tea extract (GTE), and rooibos tea extract (RTE) were investigated, the effects of additional emulsifiers such as polyglycerol and sucrose esters of fatty acids on the oxidation stability of the emulsion were also investigated. Under oxidative conditions of 30°C in 650 lx, Toc was more effective than GTE in suppressing the increase of the peroxide value (PV, meq/kg) of the emulsified milk fat. Under these oxidative conditions, the antioxidative effect of GTE was enhanced by the addition of polyglycerol and sucrose esters of fatty acids. Under the oxidative conditions at 40°C in dark with 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) or 2,2'-azobis (2,4-dimethylvaleronitrile) (AMVN), Toc showed the most antioxidative effect on suppression of the increase of PV and anisidine value (AnV) of the emulsified milk fat. Furthermore, additional emulsifiers also showed suppressive effects on the increase of the PV and AnV of the emulsified milk fat even without any antioxidants. The effects of additional emulsifiers on the oxidative stability of O/W emulsions were enhanced with antioxidants such as Toc, EGCg, and Qu.

Extraction and characterization of glucosinolates and isothiocyanates from rape seed meal.

While some isothiocyanate (ITCs) are attractive targets for the agricultural and pharmaceutical industries, the presence of goitrin and ITCs has hampered the widespread utilization of rapeseed meal. ITCs are the products of the myrosinase-mediated hydrolysis of glucosinolate (GSLs). As such, a study was conducted in order to gain a better understanding into the identity of the GSLs contained in rapeseed meal. Extraction of the GSLs was carried out with 20% ethanol, affording 3.0% GSL content. The resulting GSL extracts were purified via silica gel column chromatography resulting in the isolation of main three pure GLSs (GSL A, B, and C) and a final GSL content of 39.8%. The indirect-identification of the GSLs in rapeseed meal was also carried out via GC/MS analysis of ITCs. The GSLs, progoitrin and gluconapin, were present in the highest concentration in these extracts. Interestingly, only goitrin was produced when GSL A was the substrate for the defatted rapeseed meal mediated hydrolysis reaction. This indicates GSL A is a progoitrin. Conversely, 3-butenyl ITC was produced only when GSL B was used as substrate, indicating GSL B is gluconapin. These results will be helpful for opening the doors for the use of rapeseed meal in the agricultural or pharmaceutical sectors.

Oxidation behavior of triacylglycerol containing conjugated linolenic acids in sn-1(3) or sn-2 position.

The location of unsaturated fatty acid in triacylglycerols (TAGs) affects their oxidative stability. Herein, we studied the effect of location of conjugated linolenic acids (CLNs) in TAGs on their oxidative stability. First, the TAGs containing CLNs at sn-1(3) and sn-2 positions, were enzymatically prepared via Lipozyme RM-IM (immobilized Rhizomucor miehei lipase)-mediated acidolysis- and contained ca. 60% of CLNs at sn-1(3) or sn-2 position. The auto-oxidation test at 30°C in the dark showed oxidative stability of TAGs that mainly contained CLNs at sn-2 position was higher than that at sn-1(3) position based on peroxide value, anisidine value, polymeric substance and polar compound contents. Moreover, the thermal-oxidation test at 90°C for 24 h, showed the same result. Furthermore, even after 24 h of thermal oxidation, the oxidative stability of the TAGs containing CLNs at sn-2 positions rather than sn-1(3) positions remained at a higher level. Thus, the results showed that the TAG-containing CLNs are stable when the CLNs are located at sn-2 positions.

Analysis of predisposing factors in elderly people with type II odontoid fracture.

BACKGROUND CONTEXT: Type II odontoid fracture is the most frequent individual fracture in elderly people. An older person usually sustains a Type II odontoid fracture in a fall from standing or a seated height. A relationship between osteoarthritis in the upper cervical spine and Type II odontoid fracture has been reported. However, to our knowledge, few reports have investigated statistically whether disproportionate degeneration between joints influences the susceptibility to fracture. PURPOSE: The purpose of this study was to assess predisposition to Type II odontoid fracture in the elderly. STUDY DESIGN: Retrospective review of elderly patients sustained Type II odontoid fracture and other axis fractures. PATIENT SAMPLE: Thirty-eight patients aged 65 years and older with axis fractures. OUTCOME MEASURES: Evaluation of computed tomography findings by focusing on osteoporosis and the disproportion in degeneration between each of the upper cervical joints (atlantooccipital, atlantoodontoid, and lateral atlantoaxial joints). METHODS: Seventeen patients had a Type II odontoid fracture, and 21 patients had other axis fractures. Using the computed tomography findings, we classified osteoporosis at the dens-body junction and the severity of degenerative changes in the atlantoodontoid, atlantooccipital, and lateral atlantoaxial joints as none, mild, moderate, or severe. The proportion of patients with moderate or severe osteoporosis and degenerative changes in each joint and that of patients with disproportionate degenerative changes between joints (difference in grade of ≥2 levels between joints) were compared statistically. The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this article. RESULTS: Patients with osteoporosis and with disproportionate degenerative changes between the atlantoodontoid and lateral atlantoaxial joints were significantly more likely to have a Type II odontoid fracture than other axis fractures. These two factors were also assessed in multivariate logistic analysis. The disproportionate degenerative change between the atlantoodontoid and lateral atlantoaxial joint remained significant, even after adjusting for osteoporosis. CONCLUSIONS: Older patients with the dens fixed to the atlas because of degeneration of the atlantoodontoid joint and a smooth lateral atlantoaxial joint seem to sustain Type II odontoid fractures because, during a simple fall, the rotation of the head produces torque force on the osteoporotic dens-body junction, which acts as the rotatory center. The presence of the disproportionate osteoarthritic degeneration between the atlantoodontoid and lateral atlantoaxial joints predisposes older people to a Type II odontoid fracture.

Characterization of calcium ion sensitive region for ß-mannanase from Streptomyces thermolilacinus.

Despite the widespread industrial applications of ß-mannanase, the relations between the enzymatic properties and metal ions remain poorly understood. To elucidate the effects of metal ions on ß-mannanase, thermal stability and hydrolysis activity were characterized. The stman and tfman genes encoding ß-mannanase (EC.3.2.1.78) from Streptomyces thermolilacinus NBRC14274 and Thermobifida fusca NBRC14071 were cloned and expressed in Escherichia coli. The thermal stability of each enzyme shifted to the 7-9°C high temperature in the presence of Ca(2+) compared with that in the absence of Ca(2+). These results show that the thermal stability of StMan and TfMan was enhanced by the presence of Ca(2+). StMan, but not TfMan, required Ca(2+) for the hydrolysis activity. To identify the Ca(2+) sensitive region of StMan, we prepared eight chimeric enzymes. Based on the results of the relationship between Ca(2+) and hydrolysis activity, the region of amino-acid residues 244-349 of StMan was responsible for a Ca(2+) sensitive site.

MS/MS fragmentation-guided search of TMG-chitooligomycins and their structure-activity relationship in specific ß-N-acetylglucosaminidase inhibition.

The reducing tetrasaccharide TMG-chitotriomycin (1) is an inhibitor of ß-N-acetylglucosaminidase (GlcNAcase), produced by the actinomycete Streptomyces anulatus NBRC13369. The inhibitor shows a unique inhibitory spectrum, that is, selectivity toward enzymes from chitin-containing organisms such as insects and fungi. Nevertheless, its structure-selectivity relationship remains to be clarified. In this study, we conducted a structure-guided search of analogues of 1 in order to obtain diverse N,N,N-trimethylglucosaminium (TMG)-containing chitooligosaccharides. In this approach, the specific fragmentation profile of 1 on ESI-MS/MS analysis was used for the selective detection of desired compounds. As a result, two new analogues, named TMG-chitomonomycin (3) and TMG-chitobiomycin (2), were obtained from a culture filtrate of 1-producing Streptomyces. Their enzyme-inhibiting activity revealed that the potency and selectivity depended on the degree of polymerization of the reducing end GlcNAc units. Furthermore, a computational modeling study inspired the inhibitory mechanism of TMG-related compounds as a mimic of the substrate in the Michaelis complex of the GH20 enzyme. This study is an example of the successful application of a MS/MS experiment for structure-guided isolation of natural products.

Clinical features of the extension teardrop fracture of the axis: review of 13 cases.

OBJECT: Extension teardrop fracture of the axis is an extremely rare cervical spinal injury. The classic clinical features, which have mainly been described by radiologists rather than spine surgeons, include its occurrence in elderly patients with osteoporosis, an association with minimal or no prevertebral soft-tissue swelling, and an absence of associated neurological deficit. However, recent case studies indicate notable exceptions to these clinical features, although few studies have investigated osteoporosis in these patients. The purpose of the present study was to clarify the clinical features of extension teardrop fracture of the axis. METHODS: The authors retrospectively reviewed data obtained in 13 patients with regard to their injury etiology, neurological deficit, treatment and outcome (residual neck pain), and imaging findings (size and displacement of the fragment, C2-3 subluxation, disc injury, and osteoporosis of the axis). RESULTS: Extension teardrop fracture of the axis constituted 11.6% of upper cervical spinal injuries at the authors' institute. The mean age of the patients was 49.5 years and distinct osteoporosis was identified in only 1 patient. A C2-3 subluxation was observed in 2 patients, in whom the displacement of the fragment was significant, although its size did not appear to have an effect. Magnetic resonance imaging, undertaken in 7 patients within 48 hours of injury, showed no disc injuries. Instability of the cervical spine was absent in all patient at follow-up. Only one patient underwent surgery for the presenting symptoms of dysphagia. The other patients were treated conservatively. The authors examined 9 patients directly; these patients had bony fusion and did not complain of neck pain, except for a patient with traumatic spondylolisthesis. CONCLUSIONS: Extension teardrop fracture of the axis is generally caused by hyperextension of the cervical spine caused by a direct high-energy blow to the forehead or mandible. Based on the present case study, the authors believe that osteopenia and older age should not be considered risk factors. Most patients with an extension teardrop fracture of the axis can be treated conservatively, and surgical intervention may only be indicated for specific cases, such as those in which a patient presents with dysphagia or with other complicated fractures.