Subcellular structure of bovine thyroid gland. VII. A study on the distribution of bovine thyroid plasma membranes by density gradient centrifugation in zonal rotors.

In order to obtain plasma membrane-rich fractions two methods were tried. Approach A was based on differential pelleting followed by discontinous gradient centrifugation in a B-XIV zonal rotor. In approach B homogeneization was performed in buffered water (NaHCO3, pH 7.4). The 73 300 X g pellet from this homogenate was subjected to buoyant density equilibrium in a HS zonal rotor (continuous sucrose gradient). Using approach A, the highest relative specific activity for plasma membrane markers was found at the 30-37% sucrose interphase. However, an increase for glucose 6-phosphatase (endoplasmic reticulum marker) was also found at that interphase. Using approach B marker profiles different from approach A were found. Approach B results in a subdivision of membrane material in four distinct regions. These regions do not contain completely pure membrane species, although region I seems to be essentially derived from plasma membranes. It is also concluded from approach A that plasma membranes from bovine thyroid tissue are heterogeneous.     

Investigation of an expert systems approach to bacterial identification

An investigation was carried out to assess the feasibility ofusing an expert systems approach to assist in the identificationof unknown isolates of bacteria. A system was developed usingLisp which utilized the knowledge stored in standard bacteriologicaltexts. A comparison of the expert systems approach and the probabilisticapproach based on Bayes Theorem was made together with the advantagesand disadvantages of each approach. Received on November 5, 1990; accepted on February 20, 1991     

Facile synthesis and cytotoxicity of triterpenoid saponins bearing a unique disaccharide moiety: hederacolchiside A1 and its analogues

An improved synthetic approach toward hederacolchiside A1, an antitumor triterpenoid saponin bearing a unique disaccharide moiety, was established. This approach began from a partially protected intermediate and avoided tedious protection-deprotection manipulation. An abnormal ring conformation (1C4) of the center arabinose residue was found in the intermediate, which may account for the unusual regioselectivity between 3-OH and 4-OH of arabinose. Two analogues of hederacolchiside A1 were then facilely prepared by this approach and exhibited significant cytotoxicity in preliminary in vitro assay.     

改良肩关节前上方入路结合锁定接骨板治疗肱骨近端骨折

目的:评价改良肩关节前上方入路结合肱骨近端锁定接骨板治疗肱骨近端骨折的优越性。方法:分别采取改良肩前上方入路(A组)、肩峰下外侧入路(B组)和肩关节前内侧入路(C组)结合锁定近端肱骨接骨板固定治疗72例肱骨近端骨折患者。比较各组患者手术时间、术中出血量及术后引流量,术后1周疼痛视觉模拟评分(Visual analogue scale,VAS),术后3月Constan-Murley评分和骨折愈合率之间的差异。结果:A组和B组手术时间无差异(P0.05),二者均大于C组(P0.05);A组和B组术中出血量、术后引流量及术后1周VAS评分无差异(P0.05),二者均小于C组(P0.05);术后3月,A组和B组Constan-Murley评分、骨折愈合率无差异(P0.05;P0.0125),二者均大于C组(P0.05;P0.0125)。结论:改良肩前上方入路治疗肱骨近端骨折具有创伤小的特点,同时具备术中改变切口扩大显露的灵活性,是一种治疗肱骨近端骨折安全有效的手术入路。     

Surgical exposure of the optic nerve in the guinea pig.

A lateral orbitotomy approach was used to surgically expose the optic nerve in the guinea pig. This approach was excellent for experimental access to the optic nerve with minimal trauma to the eye.     

Nanosphere lithography-based platform for developing rapid and high sensitivity microarray systems

A novel gold nanoarray (NA)-based platform was developed for microarray applications. This novel approach is based upon the principle of nanosphere lithography and can be used for one-step antibody immobilization. The developed platform was checked by functionalizing with cysteine followed by capturing biotinylated antibody and detecting it with dye-conjugated steptravidin. An immunoassay was performed with spiked samples containing human fetuin A antigen. The minimum limits of detection (LOD) of human fetuin A for NA-based and conventional microarray platforms were 50 pg/mL and 50 ng/mL, respectively. The developed approach was highly reproducible and unlike conventional microarray approaches the use of a spotting system was omitted because immobilization was controlled and directed on the predefined arrays. This approach could be an ideal alternative for developing microarrays. And, the ease of the strategy also allows the high throughput production of the microarrays.     

经右胸三切口与左胸两切口入路对胸中段食管癌患者手术效果、淋巴结转移和远期预后的影响

摘要 目的：探讨经右胸三切口与左胸两切口入路对胸中段食管癌患者手术效果、淋巴结转移和远期预后的影响。方法：回顾性分析2013年2月~2015年3月期间我院收治的胸中段食管癌患者90例的临床资料,根据入路方式的不同将患者分为A组（n=44,左胸两切口入路）和B组（n=46,右胸三切口入路）,比较两组患者手术效果、淋巴结转移、并发症和远期预后。结果：B组手术时间、住院时间、术后留置胸管时间均长于A组,术中出血量多于A组（P<0.05）。B组淋巴结清扫数多于A组,淋巴结总转移率则低于A组（P<0.05）。两组1年生存率比较差异无统计学意义（P>0.05）;B组3年生存率、5年生存率均高于A组（P<0.05）。两组并发症发生率比较差异无统计学意义（P>0.05）。结论：与左胸两切口入路相比,胸中段食管癌患者选用经右胸三切口入路,虽术中创伤大,术后恢复略慢,但该入路方式在淋巴结转移率、生存率方面有明显改善,且不增加并发症发生率。     

Minimally Invasive Mitral Valve Replacement Using the Valve-in-valve Technique

A 90-year-old woman with two previous mitral valve replacements, presented with pulmonary edema due to mitral regurgitation from degeneration of her bioprosthetic mitral valve. A minimally invasive approach was used to replace the bioprosthetic mitral valve. During surgery, the bioprosthetic valve was noted to be too adherent to the endocardium of the left atrium, making removal of the prosthesis not only difficult, but also potentially harmful. The new bioprosthetic valve was instead placed using a valve-in-valve approach.     

Universal method for single nucleotide substitution identification

A new approach to the identification of point mutations by allele-specific PCR was proposed. The mutation R408W of the human phenylalanine hydroxylase gene was used as a model. A high specificity of the approach was achieved by the use of primers partially complementary to the genomic DNA. Polyethylene glycol covalently attached to one of the allele-specific primers provides for the differential identification of the PCR products due to a change in electrophoretic mobility.     

Detection of Legionella spp. by fluorescent in situ hybridization in dental unit waterlines

AIMS: To confirm the presence of viable Legionella spp. in dental unit waterlines (DUWL) using fluorescent in situ hybridization (FISH) and compare this method with culture approach and also to validate the utility of an enrichment to increase FISH sensitivity. METHODS AND RESULTS: Water samples from 40 dental units were analysed. Three different techniques for detecting Legionella spp. were compared: (i) culture approach, (ii) direct FISH and (iii) FISH with a previous R2A medium enrichment (R2A/FISH). The FISH detection was confirmed by PCR. The use of the direct FISH does not improve significantly the detection of legionellae when compared with the culture. On the contrary, when R2A/FISH was performed, sensitivity was, respectively, two- and threefold higher than that with the direct FISH and culture approach. Using R2A/FISH, 63% of water samples analysed showed a contamination by legionellae. CONCLUSIONS: Legionellae detection by direct FISH and R2A/FISH in dental unit water is possible but is more rapid and more sensitive (R2A/FISH) than the culture approach. SIGNIFICANCE AND IMPACT OF THE STUDY: R2A/FISH showed that several pathogens present in DUWL are viable but may not be culturable. Unlike PCR, R2A/FISH is designed to detect only metabolically active cells and therefore provides more pertinent information on infectious risk.     

Functional assessment of neurologic impairment: track analysis in diabetic and compression neuropathies

A laboratory approach to measuring neurologic impairment has been developed that is applicable to systemic disease as well as localized nerve injury. This approach compares individual parameters of the experimental rat hind footprint (walking track) with weight- and sex-matched control track parameters; classic mathematical indexing is not utilized. The normal track data obtained for the Sprague-Dawley rat showed a significant increase in print length (PL), toe spread (TS), and intermediate toe spread (ITS) with increasing rat weight. A significant difference between male and female rats above 400 gm also was noted. For a localized injury (sciatic nerve cut), this approach demonstrated that the contralateral hind footprint was a "compensated" rather than a normal track. This approach to track analysis also was capable of demonstrating progressive neurologic impairment for a sciatic nerve compression model and a systemic disease such as diabetes, as well as demonstrating reversal of these abnormal patterns when the "disease state" was treated.     

Coping with perturbations to a layout somersault in tumbling

Tumbling is a dynamic movement requiring control of the linear and angular momenta generated during the approach and takeoff phases. Both of these phases are subject to some variability even when the gymnast is trying to perform a given movement repeatedly. This paper used a simulation model of tumbling takeoff to establish how well gymnasts can cope with perturbations of the approach and takeoff phases. A five segment planar simulation model with torque generators at each joint was developed to simulate tumbling takeoffs. The model was customised to an elite gymnast by determining subject specific inertia and torque parameters and a simulation was produced which closely matched a performance of a layout somersault by the gymnast. The performance of a layout somersault was found to be sensitive to the approach characteristics and the activation timings but relatively insensitive to the elasticity of the track and maximum muscle strength. Appropriate variation of the activation timings used during the takeoff phase was capable of coping with moderate perturbations of the approach characteristics. A model of aerial movement established that variation of body configuration in the flight phase was capable of adjusting for takeoff perturbations that would lead to rotation errors of up to 8%. Providing the errors in perceiving approach characteristics are less than 5% or 5 degrees and the errors in timing activations are less than 7ms, perturbations in the approach can be accommodated using adjustments during takeoff and flight.     

Detection and modelling of time-dependent QTL in animal populations

A longitudinal approach is proposed to map QTL affecting function-valued traits and to estimate their effect over time. The method is based on fitting mixed random regression models. The QTL allelic effects are modelled with random coefficient parametric curves and using a gametic relationship matrix. A simulation study was conducted in order to assess the ability of the approach to fit different patterns of QTL over time. It was found that this longitudinal approach was able to adequately fit the simulated variance functions and considerably improved the power of detection of time-varying QTL effects compared to the traditional univariate model. This was confirmed by an analysis of protein yield data in dairy cattle, where the model was able to detect QTL with high effect either at the beginning or the end of the lactation, that were not detected with a simple 305 day model.     

B超声引导下肋锁间隙与喙突入路连续臂丛神经阻滞对Barton骨折术后镇痛效果比较

目的:比较超声引导下肋锁间隙与喙突两种入路连续臂丛神经阻滞对Barton骨折手术患者术后的镇痛效果。方法:选择择期行Barton骨折手术患者60例,随机分为肋锁间隙入路连续臂丛神经阻滞组(A组,n=30)和喙突入路连续锁骨下臂丛神经阻滞组(B组,n=30)。两组均在超声引导下进行臂丛神经阻滞,同时留置神经阻滞导管,麻醉后2小时经神经阻滞导管连接无线电子镇痛泵。记录手术过程中神经深度、麻醉操作时间,并评估麻醉效果;记录术后第一次追加药物时间;记录麻醉后6 h、12 h、18 h、24 h、36 h、48 h静息及运动状态VAS评分;记录术后第一天和第二天镇痛泵有效按压次数及补救镇痛情况;记录患者满意度及并发症发生情况。结果:与B组相比,A组神经深度明显减浅(P<0.05),麻醉操作时间显著缩短(P<0.05),术后第一次追加药物时间延长(P<0.05),麻醉后12 h、18 h、24 h、36 h静息及运动状态VAS评分较低(P<0.05),术后第一天有效按压次数明显减少(P<0.05),患者满意度评分高(P<0.05),误穿血管发生率明显减少(P<0.05)。结论:超声引导下肋锁间隙入路与喙突入路连续锁骨下臂丛神经阻滞均可安全有效用于Barton骨折手术术后镇痛;但肋锁间隙连续臂丛神经阻滞术后镇痛效果更好,且具有神经阻滞深度浅、操作时间更短、阻滞效果更好、患者满意度更高及并发症更少等优点。     

Synthesis of phosphonate 3-phthalidyl esters as prodrugs for potential intracellular delivery of phosphonates.

A new prodrug approach for intracellular delivery of phosphonates was developed via the synthesis of 3-phthalidyl esters of 1-naphthalenemethylphosphonate. This approach is advantageous over the traditional acyloxymethyl phosphonate prodrugs, because these prodrugs do not generate formaldehyde and have improved plasma half-lives.     

不同入路腔镜手术治疗甲状腺微小乳头状癌临床疗效比较的回顾性研究

摘要 目的：回顾性对比经胸乳入路、经口腔前庭入路两种入路方式治疗甲状腺微小乳头状癌（PTMC）的疗效。方法：回顾性分析南方医科大学附属南海医院甲状腺血管外科2019年1月-2021年6月期间接收的141例单侧PTMC患者的临床资料。按照入路方式的不同将患者分为A组（n=83,经胸乳入路）和B组（n=58,经口腔前庭入路）,对比两组患者的创伤应激指标、手术相关指标、美容满意度、并发症及随访预后情况。结果：B组的手术时间长于A组,中央区淋巴结清扫数目多于A组,术后第1 d引流量、术中出血量少于A组,术后第1 d颈部VAS评分、切口总长度小于A组,术后住院时间短于A组（P<0.05）。术前、术后2 d,两组白细胞计数（WBC）、C反应蛋白（CRP）、前列腺素E₂（PGE₂）、皮质醇（Cor）水平组间对比无差异（P>0.05）;两组术后2 d,WBC、PGE2、CRP、Cor水平均较术前升高（P<0.05）。B组的美容满意率高于A组（P<0.05）。两组并发症发生率组间对比无差异（P>0.05）。术后随访1年,两组患者的死亡率、复发率、颈部淋巴结转移率均为0,组间对比无差异（P＞0.05）。结论：经口腔前庭入路可获得与经胸乳入路治疗PTMC相当的手术疗效,但经口腔前庭入路清除中央淋巴结数目更多,创伤小,术后疼痛轻,同时美容满意度更高。     

Relatively strong automatic appetitive action-tendencies in male carriers of the OPRM1 G-allele

This study investigated whether automatic approach action tendencies for alcohol-related stimuli were associated with variation in the mu-opioid receptor gene ( OPRM1 ), previously related to rewarding effects of alcohol and craving. An adapted approach avoidance task was used, in which participants pulled or pushed a joystick in reaction to the format of a picture shown on the computer screen (e.g. pull landscape pictures and push portrait pictures). Picture size on the screen changed upon joystick movement, so that upon a pull movement picture size increased (creating a sense of approach) and upon a push movement picture size decreased (avoidance). Participants reacted to four categories of pictures: alcohol-related, other appetitive, general positive and general negative. The sample consisted of 84 heavy drinking young men without a g-allele in the A118G (or A355G) single nucleotide polymorphism of the OPRM1 gene and 24 heavy drinking young men with at least one g-allele. Heavy drinking carriers of a g-allele showed relatively strong automatic approach tendencies for alcohol (approach bias). Unexpectedly, they also showed an approach bias for other appetitive stimuli. No approach bias was found for general positive or negative stimuli. These results suggest that automatic approach tendencies in response to appetitive stimuli could play a role in the etiology of addictive behaviors and related disorders. Further research is needed to investigate the specificity of this approach bias and possible gender differences.     

Conditioning the pecking motions of pigeons

The spatio-temporal courses of head and neck motions of pigeons while pecking at small grains are described. Single and serial pecks are distinguished but the inter- and intraindividual variability of the peck kinetics is stressed. Pigeons were then trained with instrumental conditioning procedures to speed-up their pecking. A partial reinforcement schedule where pigeons had to peck repeatedly before receiving reward led to a mild shortening of inter-peck intervals at lower reinforcement rates but surprisingly, a lengthening at higher rates. A schedule where short inter-peck intervals were differentially rewarded yielded a pronounced abbreviation of the inter-peck intervals, but this was achieved by a reduction of the movement path rather than an increase in motion velocity. A schedule whereby increased approach velocities were differentially rewarded yielded marked movement accelerations. When pigeons were rewarded for diminished approach speeds they also showed significant movement decelerations. Finally, it is shown that pigeons could learn to reliably abort their peck approach movement when a visual stimulus signalling a penalty was occasionally presented during the approach movement. The proportion of successful peck interruptions decreased as these interruption signals occurred later during the approach phase. It is concluded that the pecking of pigeons is neither an innately fixed nor a visually ballistic movement. It is instead a multiply controlled and flexibly adaptable response pattern.     

Immobilization of lipase on cotton cloth using the layer-by-layer self-assembly technique

Lipase from Thermomyces lanuginosus was assembled into multiple layers on polyethylenimine treated cotton flannel cloth, utilising the enzymes property of forming bimolecular aggregates via layer-by-layer (LBL) immobilization technique. An increase in lipase activity with increasing enzyme layers confirmed lipase aggregation. A study to compare the activity of enzyme bound by classical LBL technique, containing alternate layers of polyethylenimine and lipase and the modified approach indicated above, showed that more enzyme was bound to cloth in the modified approach. A total of 13 U/cm² of enzyme were bound to cloth till the fifth layer whereas only 10.2 U/cm² were bound till the fifth bilayer in the classical approach. The successful assembly of lipase molecules has shown that this modified technique is a promising approach to immobilize enzymes that aggregate through hydrophobic interactions as nano-films on cloth.     

Attractivity of male and female rats after early endocrine manipulation

Approach behavior toward males and approach behavior toward females were studied in the male rat. Adult male rats approached neonatally castrated male rats more than they approached intact males. Neonatally androgenized female rats and estrous female rats were equally approached. A preferential approach toward the androgenized female was evident when the alternative incentive was a proestrous female. These adult patterns of approach behavior appeared on Day 50 after birth. It is concluded that early endocrine manipulation influences the attractivity of the incentives.