Functional morphology of the respiratory organs of the air-breathing fish with particular emphasis on the African catfishes, Clarias mossambicus and C. gariepinus

The evolution of air-breathing and transition from water to land were pivotal events that greatly determined the ecological diversification, the advances and the successes of animal life. During their relocation onto land, the so-called bimodal breathers were literally caught at the water-air interface. Among such animals are the diverse air-breathing bony fish. Such taxa, however, strictly do not constitute the so-called ‘bridging animals’, i.e., the inaugural animals that crossed from water to land, nor are they their direct progenitors. The pioneer transitional animals were the Devonian rhipidistian amphibians that possessed a primitive lung which acquired O₂ directly from air and discharged CO₂ back into the same. By having particular morphological and physiological adaptations for terrestrialness, the modern amphibious- and aquatic air-breathers are heuristic analogues of how and why animals relocated from water to land. It has generally been espoused that lack or dearth of O₂ in water, especially in the warm tropical one, was an elemental driver for adoption of air-breathing. There is, however, no direct causal relationship between the evolution of air-breathing and the shift onto land: the move onto land was a direct solution to the existing inimical respiratory conditions in water. This is evinced in the facts that: a) even after attaining capacity of air-breathing, an important preadaptation for life on land, some animals continued living in water while periodically accessing air, b) in the fish species that live in the well-oxygenated waters, e.g., torrential rivers, only few air-breathe and c) air-breathing has still evolved in freshwaters and seawaters, where levels of dissolved O₂ are sufficiently high. Here, the structure and function of the respiratory organs of the air-breathing fish are succinctly outlined. Two African catfishes, Clarias mossambicus and C. gariepinus are highlighted.     

Variations in internal structure,composition and protein distribution between intra‐ and extra‐articular knee ligaments and tendons

Tendons and ligaments play key roles in the musculoskeletal system in both man and animals. Both tissues can undergo traumatic injury, age‐related degeneration and chronic disease, causing discomfort, pain and increased susceptibility to wider degenerative joint disease. To date, tendon and ligament ultrastructural biology is relatively under‐studied in healthy, non‐diseased tissues. This information is essential to understand the pathology of these tissues with regard to function‐related injury and to assist with the future development of tissue‐engineered tendon and ligament structures. This study investigated the morphological, compositional and extracellular matrix protein distribution differences between tendons and ligaments around the non‐diseased canine stifle joint. The morphological, structural characteristics of different regions of the periarticular tendons and ligaments (the intra‐articular anterior cruciate ligament, the extra‐articular medial collateral ligament, the positional long digital extensor tendon and energy‐storing superficial digital flexor tendons) were identified using a novel semi‐objective histological scoring analysis and by determining their biochemical composition. Protein distribution of extracellular matrix collagens, proteoglycans and elastic fibre proteins in anterior cruciate ligament and long digital extensor tendon were also determined using immunostaining techniques. The anterior cruciate ligament was found to have significant morphological differences in comparison with the other three tissues, including less compact collagen architecture, differences in cell nuclei phenotype and increased glycosaminoglycan and elastin content. Intra‐ and interobserver differences of histology scoring resulted in an average score 0.7, indicative of good agreement between observers. Statistically significant differences were also found in the extracellular matrix composition in terms of glycosaminoglycan and elastin content, being more prominent in the anterior cruciate ligament than in the other three tissues. A different distribution of several extracellular matrix proteins was also found between long digital extensor tendon and anterior cruciate ligament, with a significantly increased immunostaining of aggrecan and versican in the anterior cruciate ligament. These findings directly relate to the different functions of tendon and ligament and indicate that the intra‐articular anterior cruciate ligament is subjected to more compressive forces, reflecting an adaptive response to normal or increased loads and resulting in different extracellular matrix composition and arrangement to protect the tissue from damage.     

Preserving normal ventricular activation versus atrioventricular delay optimization during pacing: the role of intrinsic atrioventricular conduction and pacing rate

The purpose of the study was to compare the effects of DDD pacing with optimal AV delay and AAI pacing on the systolic and diastolic performance at rest in patients with prolonged intrinsic AV conduction (first-degree AV block). We studied 17 patients (8 men, aged 69 +/- 9 years) with dual chamber pacemakers implanted for sick sinus syndrome in 15 patients and paroxysmal high degree AV block in 2 patients. Aortic flow and mitral flow were evaluated using Doppler echocardiography. Study protocol included the determination of the optimal AV delay in the DDD mode and comparison between AAI and DDD with optimal AV delay for pacing rate 70/min and 90/min. Stimulus-R interval during AAI (ARI) was 282 +/- 68 ms for rate 70/min and 330 +/- 98 ms for rate 90/min (P < 0.01). The optimal AV delay was 159 +/- 22 ms. AV delay optimization resulted in an increase of an aortic flow time velocity integral (AFTVI) of 16% +/- 9%. At rate 70/min the patients with ARI < or = 270 ms had higher AFTVI in AAI than in DDD (0.214 +/- 0.05 m vs 0.196 +/- 0.05 m, P < 0.01), while the patients with ARI > 270 ms demonstrated greater AFTVI under DDD compared to AAI (0.192 +/- 0.03 m vs 0.166 +/- 0.02 m, P < 0.01). At rate 90/min AFTVI was higher during DDD than AAI (0.183 +/- 0.03 m vs 0.162 +/- 0.03 m, P < 0.01). Mitral flow time velocity integral (MFTVI) at rate 70/min was higher in DDD than in AAI (0.189 +/- 0.05 m vs 0.173 +/- 0.05 m, P < 0.01), while at rate 90/min the difference was not significant in favor of DDD (0.149 +/- 0.05 m vs 0.158 +/- 0.04 m). The results suggest that in patients with first-degree AV block the relative impact of DDD and AAI pacing modes on the systolic performance depends on the intrinsic AV conduction time and on pacing rate.     

直接前路与后外侧入路人工股骨头置换治疗老年移位性股骨颈骨折的临床疗效对比

目的比较直接前路与后外侧入路人工股骨头置换术治疗老年移位性股骨颈骨折的临床治疗效果。方法选取2013年6月至2015年6月我科诊治的老年单侧移位性股骨颈骨折患者73例,其中采用直接前路36例(直接前路组),后外侧入路37例(后外侧入路组),分析其手术用时、切口长短及愈合时间、手术出血及伤口引流量、下床时间及住院天数,术后3天、7天疼痛视觉评分(VAS),术前、术后1、3、6、9、12个月及末次随访时髋关节Harris评分,术后脱位发生率及其他并发症发生情况。采用欧洲生活质量评分(EQ-5D评分)评价末次随访时患者健康生活质量。结果患者均获得随访,随访时间12~17个月,平均13.6个月。直接前路组的手术用时、切口长度、术中出血量及术后引流量小于后外侧入路组(P0.05),两组下地行走时间、伤口愈合时间无统计学差异(P0.05);直接前路组术后3天、7天疼痛视觉评分优于后外侧入路组;术后1月、3月、6月直接前路组Harris评分高于对照组,术后9、12个月及末次随访时两组Harris评分基本接近。两组患者术后末次随访时健康生活质量无统计学差异(P0.05)。直接前路组1例患者出现伤口局部红肿,后外侧入路组1例患者出现假体脱位,1例出现切口周缘麻木,两组患者无肺栓塞、下肢静脉血栓形成并发症。结论直接前路和后外侧入路均能有利于髋关节运动功能的恢复,早期临床疗效较好。直接前路手术创伤小,出血少,假体脱位发生率低,术后早期疗效好等优势,但直接前路手术对术者的手术技术要求较高。     

腹腔镜与开腹直肠癌保肛手术的临床对比研究

目的探讨腹腔镜直肠癌保肛手术的可行性、安全性及优越性。方法将2004年12月～2006年3月收治的可以行保肛手术直肠癌患者60例,随机分腹腔镜组和传统开腹组进行手术,对其临床资料进行比较分析。结果腹腔镜组29例,开腹手术28例。腹腔镜组术中出血量、手术切口长度、术后疼痛评分VAS、恢复肠道功能的时间和下床活动时间[(69±48)mL、(5.1±1.5)cm、(5.3±2.1)、(31±11)h和(2.5±1.2)d)]明显低于开腹手术组[(172±67)mL、(19.8±4.7)cm、(9.2±2.9)、(82±13)h和(7.2±2.8)d],腹腔镜组手术时间(172±36)min明显长于开腹手术组(142±47)min,两组之间差异均存在显著性,P<0.01。两组在肠段切除长度、肿块距下切缘距离和淋巴结清扫范围方面比较,差异无显著性,P>0.05。开腹手术组术中肉眼血尿、术后切口感染发生机会多于腹腔镜组,两组吻合口瘘的发生率基本相同。结论腹腔镜直肠癌根治手术创伤小,恢复快,安全可靠,对于能够按照TME原则进行手术保肛的直肠癌患者,能够取得与开腹手术同样的肿瘤根治性效果。     

Unlike adults,children and adolescents show predominantly increased neural activation to social exclusion by members of the opposite gender

The effects of group membership on brain responses to social exclusion have been investigated in adults, revealing greater anterior cingulate responses to exclusion by members of one’s in-group (e.g., same-gender). However, social exclusion is a critical aspect of peer relations in youth and reaches heightened salience during adolescence, a time when social anxiety disorders are also emergent. While the behavioral and neural correlates of social exclusion in adolescence have been extensively explored, the effects of group membership on peer rejection are less clear. The current study used functional magnetic resonance imaging (fMRI) to investigate the differential neural correlates of being excluded by peers of one’s same- versus opposite-gender during an online ball-toss game. Participants were a group of typically developing children and adolescents (7–17 years). As predicted, anterior cingulate cortex showed a main effect of social exclusion versus fair play. However, unlike a previous adult study, this region did not show increased activation to same-gender exclusion. Instead, several regions differentiating same- versus opposite-gender exclusion were exclusively more sensitive to exclusion by one’s opposite gender. These results are discussed in the context of adolescent socio-emotional development.     

Temporal control of glucocorticoid neurodynamics and its relevance for brain homeostasis,neuropathology and glucocorticoid-based therapeutics

Glucocorticoids mediate plethora of actions throughout the human body. Within the brain, they modulate aspects of immune system and neuroinflammatory processes, interfere with cellular metabolism and viability, interact with systems of neurotransmission and regulate neural rhythms. The influence of glucocorticoids on memory and emotional behaviour is well known and there is increasing evidence for their involvement in many neuropsychiatric pathologies. These effects, which at times can be in opposing directions, depend not only on the concentration of glucocorticoids but also the duration of their presence, the temporal relationship between their fluctuations, the co-influence of other stimuli, and the overall state of brain activity. Moreover, they are region- and cell type-specific. The molecular basis of such diversity of effects lies on the orchestration of the spatiotemporal interplay between glucocorticoid- and mineralocorticoid receptors, and is achieved through complex dynamics, mainly mediated via the circadian and ultradian pattern of glucocorticoid secretion. More sophisticated methodologies are therefore required to better approach the study of these hormones and improve the effectiveness of glucocorticoid-based therapeutics.     

Age‐related changes in amygdala–frontal connectivity during emotional face processing from childhood into young adulthood

The ability to process and respond to emotional facial expressions is a critical skill for healthy social and emotional development. There has been growing interest in understanding the neural circuitry underlying development of emotional processing, with previous research implicating functional connectivity between amygdala and frontal regions. However, existing work has focused on threatening emotional faces, raising questions regarding the extent to which these developmental patterns are specific to threat or to emotional face processing more broadly. In the current study, we examined age‐related changes in brain activity and amygdala functional connectivity during an fMRI emotional face matching task (including angry, fearful, and happy faces) in 61 healthy subjects aged 7–25 years. We found age‐related decreases in ventral medial prefrontal cortex activity in response to happy faces but not to angry or fearful faces, and an age‐related change (shifting from positive to negative correlation) in amygdala–anterior cingulate cortex/medial prefrontal cortex (ACC/mPFC) functional connectivity to all emotional faces. Specifically, positive correlations between amygdala and ACC/mPFC in children changed to negative correlations in adults, which may suggest early emergence of bottom‐up amygdala excitatory signaling to ACC/mPFC in children and later development of top‐down inhibitory control of ACC/mPFC over amygdala in adults. Age‐related changes in amygdala–ACC/mPFC connectivity did not vary for processing of different facial emotions, suggesting changes in amygdala–ACC/mPFC connectivity may underlie development of broad emotional processing, rather than threat‐specific processing. Hum Brain Mapp 37:1684–1695, 2016. © 2016 Wiley Periodicals, Inc .