Detection of Methicillin-Resistant Staphylococcus aureus Using mecA/nuc Genes and Antibiotic Susceptibility Profile of Malaysian Clinical Isolates

The aim of this study is to compare methicillin-resistant Staphylococcus aureus (MRSA) detection methods and to generate antibiogram profile of S. aureus clinical isolates from two teaching hospitals in Malaysia including three reference isolates from American Type Culture Collection (ATCC). The mecA/nuc gene PCR amplification, spot inoculation test and oxacillin disc diffusion test were applied to compare its MRSA detection abilities. No disagreement between the three methods was observed. From 29 bacterial isolates (including the ATCC strains) tested, 19 isolates were confirmed as S. aureus with 14 isolates exhibiting multidrug-resistance. All isolates are still susceptible to vancomycin as indicated by the E-test result. Current biochemical tests are comparable with the molecular detection method for MRSA used in this study while multidrug-resistance traits are present in both MRSA and MSSA clinical isolates. Presently, mupirocin seems to be the best alternative for vancomycin against multidrug-resistant S. aureus infections in Malaysia. Susceptibility profile of 19 S. aureus isolates acquired from two teaching hospitals and ATCC towards 16 selected antibiotics was analyzed and an antibiogram was generated. Findings also indicated resistance against many of the available antibiotics and thus an urgent need to search for alternative antibiotics.     

加减止痉散配合推拿治疗腰椎间盘突出症的临床应用

目的：分析腰椎间盘突出症采用止痉散加减配合推拿治疗的临床应用效果。方法：将2013 年10 月～2014年10月我院中医 门诊收治的90 例腰椎间盘突出症患者,将其按随机数字表法分为对照组和治疗组(n=45)。对照组患者采用针刺、推拿及牵引疗 法,治疗组患者在此基础上给予中药止痉散加减进行治疗。对比两组患者的临床总有效率及直腿抬高试验结果。结果：治疗组的 临床总有效率(97.78%)明显高于对照组的临床总有效率(75.56%),差异具有统计学意义(P＜0.05);另外,治疗组直腿抬高试验＞ 70° 的比例(68.89%)明显高于对照组的(42.22%),差异具有统计学意义(P＜0.05)。结论：止痉散加减配合推拿治疗腰椎间盘突出症 具有较好的临床效果。     

Performance of a three-stage aerobic RBC reactor in food canning wastewater treatment

Biological treatment using attached growth in a three-stage lab-scale rotating biological contactor (RBC) was implemented for wastewater from food cannery industries. The wastewater contained high level of organic compounds due to fish and fruit cleaning, cooking and filling processes. Nutrients available in the wastewater enhanced the growth of microorganisms and allowed the biological treatment to be effective. The RBC consisted of 54 parallel discs rotating in a reservoir and was arranged in three stages, i.e. 18 discs oriented in each stage. Effect of major operating and physical variables such as hydraulic retention time (HRT), disc submergence and disc rotational speed were examined in COD removal. For duration of 5 days, 96.4% BOD removal was achieved in batch experiment. BOD constant rate (k) and ultimate BOD were determined respectively, 0.8198 day⁻¹ and 6349 mg/l by Thomas graphical method. COD removal efficiency was increased from 85.3 to 97.4% while the HRT was increased from 24 to 48 h. The COD removal efficiency increased from 74.9 to 87.5% as the disc submergence was increased from 31 to 36%. At submergence level of 23.7%, removal efficiency was increased due to activation of second and third compartments. When the rotational speed was increased from 3 to 11 rpm, the COD removal efficiency was also increased from 62.7 to 93.7%, respectively. The stage COD removal efficiency was gradually decreased with an increase number of stage and about 88% of organic compounds were removed in the first stage of aerobic RBC, indicating that the single stage reactor may be sufficient in practical application.     

持久脊柱负荷与椎间盘组织中MMP-2表达关系的研究

目的：建立一压力可控型椎间盘退变模型,并探讨持久的脊柱负荷对椎间盘MMP-2表达的影响。方法：选用54只成年Wistar大鼠随机分为三组,分别模拟人类在站立（A组1.12N）、坐位直立（B组1.68N）、坐位前屈（C组3.08N）三种状态下椎间盘内的负荷情况,给予大鼠尾椎Co9/10椎间盘恒定压力加压,以相邻Co8/9椎间盘不加压作为对照（D组）。三组分别在3、7、14天后取受压及对照椎间盘标本,进行HE染色组织学观察及免疫组织化学分析,观察椎间盘退变情况及MMP-2在椎间盘组织中的含量变化。结果：随时间与压力的增加,椎间盘组织学评分与MMP-2表达增高（P〈0.05）,MMP-2表达与椎间盘退变程度成正相关（r=0.870,P〈0.05）。结论：持久的脊柱负荷可引起椎间盘退变及MMP-2表达增加,MMP-2可能在椎间盘退变的过程中发挥重要作用。     

Changes in duration of developmental phases of durum wheat caused by breeding in Spain and Italy during the 20th century and its impact on yield

Background and Aims

Although the apical development of wheat has been widely described, studies analysing how genetic breeding over the 20th century influenced the developmental phases and its consequences on yield generation are lacking, especially for durum wheat under field conditions in Mediterranean environments. The aims of this study were to analyse the effects of breeding in Spain and Italy on crop development during the last century, to determine whether or not breeding significantly altered the developmental phases between sowing and maturity, and to evaluate the importance of each phase in determining the number of grains per spike of durum wheat (Triticum durum) cultivars representing the germplasm grown throughout the 20th century in Spain and Italy.

Methods

Eight field experiments were carried out during 4 years in two contrasting latitudes (Lleida and Granada, Spain). Plant material consisted of 24 durum wheat cultivars (12 Italian and 12 Spanish) grown throughout the 20th century in Spain and Italy.

Key Results

In Spanish materials, breeding reduced the duration of the period from sowing to anthesis, placing the grain-filling period in better conditions. In those cultivars, the sub-phase sowing–terminal spikelet formation was reduced while the duration of the period from booting to anthesis was increased. The number of grains per spike increased by 23 % from old to modern cultivars, by changes in the number of grains per spikelet in both Spanish and Italian cultivars. Floral abortion from booting to anthesis diminished by 24 % from old to modern cultivars, and grain setting increased by 13 %.

Conclusions

The results suggest that breeding reduced not only plant height, but also the time to anthesis. By extending the duration of the phase from booting to anthesis, which was associated with an increase in spike dry weight and grains per spike, it suggests that future increases in spike fertility could be achieved by enlarging that phase.     

Interleukin-23 is constitutively expressed in the human annulus in vivo and in vitro,and is up-regulated in vitro by TNF-α

ABSTRACT

Interleukin-23 (IL-23, IL-23p19) is a proinflammatory cytokine in the IL-12-related family. Although inflammatory cells in herniated discs have been shown to contain IL-23, little is known about the presence and role of IL-23 in human disc cells. We analyzed disc specimens for IL-23 localization using immunohistochemistry in control, herniated and non-herniated discs from which annulus fibrosus (annulus) cells were isolated and cultured to identify IL-23 gene expression and production. Microarray analysis was used to assess the expression of IL-23 in disc tissue and in cells exposed to two proinflammatory cytokines, IL-1ß and TNF-α. IL-23 was present in annulus cells at the protein level and its expression was up-regulated significantly in herniated compared to control disc tissue. Direct measurement of medium components confirmed production of IL-23 and its receptor, IL-23R, by annulus cells in vitro. Annulus cells in three-dimensional culture exposed to TNF-α, but not IL-1ß, resulted in significant up-regulation of IL-23 expression compared to control cells. Our findings are evidence for the constitutive presence of IL-23 in the human disc and that its expression in vitro is modified by exposure to TNF-α.     

Tenascin in the human intervertebral disc: alterations with aging and disc degeneration

Our objective for this study was to determine the presence and distribution of tenascin in the human intervertebral disc. The tenascins are a family of extracellular matrix proteins with repeated structural domains homologous to epidermal growth factor, fibronectin type III and the fibrinogens. Little is known about the presence of this protein in the disc. Ten normal human discs donated from subjects newborn to 15 years old, 10 control discs from adult donors aged 24-41 years, and 11 surgical disc specimens from patients aged 26-76 years were examined for immunolocalization of tenascin. In young discs, tenascin was localized throughout the annulus; in the nucleus, localization was confined to pericellular matrix. In adult control and degenerating disc specimens, tenascin in the annulus was localized primarily in pericellular matrix regions encircling either single cells or clusters of disc cells; in rare instances localization was more diffuse in the intraterritorial matrix. In young, healthy disc, tenascin was abundant throughout the annulus. In contrast, degenerating discs in adults showed a localization restricted to the pericellular, and rarely, more restricted intraterritorial matrix. These observations indicate that changes in the amount and distribution of tenascin may have a role in disc aging and degeneration, possibly by modulating fibronectin-disc-cell interactions, and causing alterations in the shape of disc cells.     

Notes towards an optimal sampling strategy in dendroclimatology

Though the extraction of increment cores is common practice in tree-ring research, there is no standard for the number of samples per tree, or trees per site needed to accurately describe the common growth pattern of a discrete population of trees over space and time. Tree-ring chronologies composed of living, subfossil and archaeological material often combine an uneven distribution of increment cores and disc samples. The effects of taking one or two cores per tree, or even the inclusion of multiple radii measurements from entire discs, on chronology development and quality remain unreported. Here, we present four new larch (Larix cajanderi Mayr) ring width chronologies from the same 20 trees in northeastern Siberia that have been independently developed using different combinations of core and disc samples. Our experiment reveals: i) sawing is much faster than coring, with the latter not always hitting the pith; ii) the disc-based chronology contains fewer locally absent rings, extends further back in time and exhibits more growth coherency; iii) although the sampling design has little impact on the overall chronology behaviour, lower frequency information is more robustly obtained from the disc measurements that also tend to reflect a slightly stronger temperature signal. In quantifying the influence of sampling strategy on the quality of tree-ring width chronologies, and their suitability for climate reconstructions, this study provides useful insights for optimizing fieldwork campaigns, as well as for developing composite chronologies from different wood sources.     

Preparation of Intact Bovine Tail Intervertebral Discs for Organ Culture

The intervertebral disc (IVD) is the joint of the spine connecting vertebra to vertebra. It functions to transmit loading of the spine and give flexibility to the spine. It composes of three compartments: the innermost nucleus pulposus (NP) encompassing by the annulus fibrosus (AF), and two cartilaginous endplates connecting the NP and AF to the vertebral body on both sides. Discogenic pain possibly caused by degenerative intervertebral disc disease (DDD) and disc herniations has been identified as a major problem in our modern society. To study possible mechanisms of IVD degeneration, in vitro organ culture systems with live disc cells are highly appealing. The in vitro culture of intact bovine coccygeal IVDs has advanced to a relevant model system, which allows the study of mechano-biological aspects in a well-controlled physiological and mechanical environment. Bovine tail IVDs can be obtained relatively easy in higher numbers and are very similar to the human lumbar IVDs with respect to cell density, cell population and dimensions. However, previous bovine caudal IVD harvesting techniques retaining cartilaginous endplates and bony endplates failed after 1-2 days of culture since the nutrition pathways were obviously blocked by clotted blood. IVDs are the biggest avascular organs, thus, the nutrients to the cells in the NP are solely dependent on diffusion via the capillary buds from the adjacent vertebral body. Presence of bone debris and clotted blood on the endplate surfaces can hinder nutrient diffusion into the center of the disc and compromise cell viability. Our group established a relatively quick protocol to "crack"-out the IVDs from the tail with a low risk for contamination. We are able to permeabilize the freshly-cut bony endplate surfaces by using a surgical jet lavage system, which removes the blood clots and cutting debris and very efficiently reopens the nutrition diffusion pathway to the center of the IVD. The presence of growth plates on both sides of the vertebral bone has to be avoided and to be removed prior to culture. In this video, we outline the crucial steps during preparation and demonstrate the key to a successful organ culture maintaining high cell viability for 14 days under free swelling culture. The culture time could be extended when appropriate mechanical environment can be maintained by using mechanical loading bioreactor. The technique demonstrated here can be extended to other animal species such as porcine, ovine and leporine caudal and lumbar IVD isolation.     

Trypanosoma cruzi: Lactate dehydrogenase isoenzymes and infections in mice

Total plasma LDH isoenzyme (EC 1.1.1.27) levels increased significantly over the normal level in mice infected with strains of Trypanosoma cruzi from three different geographic locations, but some strain differences were observed. The most rapid increase was exhibited by the blood-induced Tulahuen strain, but this strain, unlike the House 510 or House 11, did not elicit an increase during the early period of infection. Overall increases in LDH-1 and LDH-2, heart isoenzymes, were most marked in vector-derived House 510 infections, but, as in the Tulahuen strain, a considerable increase was also observed in blood-induced infections. The House 510 strain also elicited significant increases in LDH-4; these were particularly high during the early period of the blood-induced infection. By contrast, the vector-derived Tulahuen strain elicited a higher increase in LDH-4 during the early period than the House 510 or House 11 strains. Comparable similarites and differences were also observed in regard to LDH-3, 5, and “X.” The most marked isoenzyme increases were those of “LDH-X” exhibited by the blood-induced House 510 and vector-derived Tulahuen strains.Parallel histopathologic studies of liver, heart, and skeletal muscle disclosed significant pathology in all the infections. Animals with blood-induced Tulahuen strain infections characteristically showed extensive necrosis with marked multiplication of parasites throughout the liver, but little or no evident damage to the heart and skeleal muscle. Animals infected with House 510 and House 11 strains exhibited minimal pathology in the liver but severe damage to the heart and skeletal muscle. Increases in LDH-4 and LDH-5, isoenzymes which represent both liver and skeletal muscle, in blood-induced Tulahuen infections were attributed largely to liver damage, but in the House 510 and House 11 infections were related more to skeletal muscle.