Pathomorphology of rat lungs during postradiation period

The xyloglucan from cotyledons of Hymenaea courbaril was hydrolysed with endo-(1,4)-beta-D-glucanase (cellulase) and analysed by TLC and HPAEC. The limit digest was different from those obtained from xyloglucans of Tamarindus indica and Copaifera langsdorffii. On treatment with nasturtium beta-galactosidase, two main oligosaccharides were detected by TLC and HPAEC. Using a process of enzymatic sequencing involving alternate treatments with a pure xyloglucan oligosaccharide-specific alpha-xylosidase, and a pure beta-glucosidase, both from nasturtium, their structures were deduced to be XXXG and a new oligosaccharide XXXXG. These structures were confirmed by 1H NMR. The relative proportions of XXXG and XXXXG indicate that approximately half of the subunits in Hymenaea xyloglucan are based on the new oligosaccharides. In the native polymer the XXXXG subunits are likely to carry galactosyl substituents in varying proportions, since cellulase hydrolysates contained many bands which were converted to XXXXG on hydrolysis with nasturtium beta-galactosidase. Although no comparative studies on the physico-chemical properties of Hymenaea courbaril xyloglucan have yet been performed, our results indicate that this polymer is less interactive with iodine when compared with T. indica and C. langsdorffii xyloglucans, suggesting that changes in conformation may occur due to the presence of XXXXG.     

Electromyographic activity of the cervical musculature during dynamic lateral bending

STUDY DESIGN: Electromyographic profiles from the neck muscles of five young, healthy men were obtained to study the muscular, activation patterns during dynamic external loading. OBJECTIVES: To examine the myoelectric activity of selected cervical muscles during dynamic loading, and to explore the reaction of the cervical muscles to different loading conditions. SUMMARY OF BACKGROUND DATA: The response of cervical muscles throughout dynamic external loading is not well understood. Electromyography provides information, within certain limitations, about the neural drive to various components of the musculature. Such information on activation, combined with geometric parameters of the musculoskeletal tissues, constitutes a tool for helping to understand the mechanism of head and neck impact-related injury. METHODS: Subjects were tested with the head and neck in the neutral and prebent positions. Dynamic loads were applied laterally to each subject by free-falling masses to create peak dynamic loads ranging from about 40 to 100 N. Force and electromyographic data were recorded, and cross-correlations from linear envelope electromyography were calculated. RESULTS: The peak electromyogram showed large differences between the two applied loads and between subjects. There were time delays (75-165 msec) between the peak applied force and the peak electromyogram. The muscles on the contralateral side demonstrated different electromyographic profiles between subjects. Within subjects, the electromyographic profiles from each muscle were consistent for the same trial conditions. CONCLUSIONS: Electromyographic profiles and the cross-correlator coefficients for cervical muscles have shown reproducible intrasubject muscle synergies, which were not sensitive to the magnitude of applied load and the posture of the head. Intersubject muscle activity patterns varied.     

Electronmicroscopic findings in the skeletal muscles of newborn swine with congenital splayleg

Pathomorphological studies were taken of 104 muscle samples (including M. longissimus dorsi, adductor, semimembranaceus) obtained from 26 piglets, aged between one and three days and received from six stocks (large whites, land race, hybrids), which exhibited symptoms of congenital splayleg. Presence of myofibrillar hypoplasia or disseminated necrotisation of fibre was established by light microscopy. Some of the piglets, however, failed to exhibit substantive changes at all. Four types of fibre were differentiated by electron microscopy: (1) the normal type (with intact fibrils, plenty of lipids etc.), (2) the hypoplastic type (inhibition of protein synthesis, lack and immaturity of fibrils, disorder of paraplasmatic substances), (3) the dystrophic type (variable defects of fibrils, decay), (4) the primitive type (myoplastlike cell elements with precipitate fibrillogenesis). While those types were of variegated intramuscular occurrence, some predominance was established of dystrophic changes. Hence, spraddle-legged piglets seem to be afflicted with disorder of muscular development accompanied by signs of myopathy. Outbreak and intensity of clinical symptoms are believed to depend on exogenous factors.     

Use of swine model in transplantation of vascularized skeletal tissue allografts

Permanent tolerance to vascularized skeletal tissue allografts can be induced in miniature swine with minor antigen differences using a 12-day course of CsA. Demonstration of skeletal tissue allograft survival in a large animal model without long-term immunosuppression represents an important step toward transplantation of skeletal tissue allografts in humans.     

Specification of the hypaxial musculature

During development of the amniote embryo, the dorsolateral territory of the somite is destined to give rise to the hypaxial skeletal musculature. To study the mechanisms that lead to the formation of this musculature, we cloned the chick Lbx1 gene that is specific to prospective hypaxial myoblasts at occipital, cervical and limb levels. Using this gene as a marker, we characterised the anatomical structures that produce the signals necessary for the specification of the hypaxial musculature by ablating them or transplanting them to ectopic locations in the chick embryo. In addition, we inserted BMP4 soaked beads medial to the somite. Our data suggest that lateralising signals from intermediate and lateral mesoderm have to synergise with dorsalising signals from the surface ectoderm to induce the formation of the hypaxial musculature. However, the lateralising function of the lateral mesoderm can only in part be mimicked by BMP4.     

Myosin heavy chain transitions during development. Functional implications for the respiratory musculature

The myosin heavy chain (MHC) exists as multiple isoforms that are encoded for by a family of genes. The respiratory musculature demonstrates muscle-specific and temporally-dependent changes in MHC isoform expression during maturation. Developmental expression of MHC isoforms correlate well with postnatal changes in actomyosin ATPase activity, specific force generation (P0/CSA), maximum unloaded velocity of shortening (V0) and and fatigue resistance. More specifically, as the expression of MHCneonatal declines and MHC2A, MHC2X, and MHC2B increase, actomyosin ATPase activity, P0/CSA, V0, and muscle fatigability increase. The increase in actomyosin ATPase activity with maturation is partially offset by a postnatal increase in oxidative capacity; however, as fatigue resistance declines with development it is apparent that the energy costs of contraction are not fully matched by an increase in energy production. Developmental transitions in smooth muscle MHC phenotype also occur although their functional importance remains unclear.     

Histopathology and ultrastructural changes of the musculature and nerves during methamidophos toxication in chicken

Primary mediastinal leiomyosarcomas are malignant sarcomas with unknown etiology not deriving from the smooth muscle fiber of the esophagus, trachea or main vessels. Very few cases have been reported in the literature and, although they are clinically unspecific, their histology is unique. The case described here is a 66-year-old woman with a leiomyosarcoma localized at the medium and posterior mediastinum, clinically presented as a mediastinal emergency.     

Pathomorphology of the kidneys in hemolytic-uremic syndrome in children

The kidneys were studied morphologically in 64 cases of hemolytic-uremic syndrome (HUS) in children aged from 17 days to 4 years. Three variants of the kidney alterations are distinguished depending on the duration of acute renal failure (ARF): early, late and delayed alterations. Early alterations were observed if ARF lasted for 1-10 days and were characterized by glomerular thrombotic microangiopathy with disturbance of the nephron proximal part function resultant from microcirculatory damage. Late kidney alterations (11-20 days of ARF) consisted of glomerular thrombi fibrinolysis, development of mesangial cell proliferation and mesangiolysis, proximal tubular epithelium regeneration and the appearance of nephrohydrosis resulting from the distal nephron part obstruction by hyalin cylinders. Delayed alterations (21-62 days of ARF) manifested with predominant atrophic and sclerotic processes. The first variant corresponded to the acute course of HUS while the two last variants to the subacute one.     

Pathomorphology of pneumococcal infection in children

The Colles' fracture is probably the most common fracture seen in the Emergency Department. Although there are several different methods of reduction and fixation, the goal of any treatment plan is to return the patient to normal function. Depending on the complexity, the Colles' fracture can be successfully treated open or closed. This article reviews the mechanism of injury, assessment, conservative or operative treatment, and rehabilitation of these fractures.     

Study of generation of sinter return fines during transportation

Abstract

Conventional tests of sinter strength such as the Tumbler test and the shatter test cannot predict the effect of transport parameters such as the drop height, conveying length, etc. on the amount of return fines generated during transport. In this work, various steps involved in transportation were simulated using customised drop and vibration tests, and the effect of sinter size, drop height and conveying time on the percentage of return fines and volume breakage was examined. Drop and vibration tests revealed that the extent of volume breakage is higher in case of larger sinter particles, but the percentage of return fines from various size fractions did not follow the corresponding trend in volume breakage. The contribution of various size fractions of sinter to generation of return fines was found to be in the order: 5–10 mm>20–30 mm～30–40 mm>10–20 mm. For any size fraction, the percentage of fines generated was found to be linearly related to the drop height in the case of drop tests and logarithmically related to the vibration time in the case of vibration tests.     

铁水输送过程中的在线温度预测模型

为了提高铁水温度管理水平，降低鱼雷罐车输送铁水过程中的温降，开发了铁水输送过程中的在线温度预测模型。该模型可以实时计算和预测重罐时的铁水温度，以及空罐时的罐衬温度。模型在宝钢铁水管理系统的应用证明计算值与实测值吻合良好。     

车站改造期间运输组织和安全管理浅见

通过介绍包神铁路东胜站设备改造期间施工、运输之间的矛盾提出了施工期间运输安全管理方面应采取的一些措施,使施工安全能得到有效的保证.     

Regulation of skeletal muscle perfusion during exercise

OBJECTIVE: To compare the composition and mechanical properties of the newly developed bladder acellular matrix graft (BAMG) with the normal urinary bladder in rat, pig and human. MATERIALS AND METHODS: Rat, pig and human urinary bladders were harvested and divided into control and experimental groups. For the latter, BAMGs were prepared, and light and transmission electron microscopic studies performed. Strips from the normal bladders and the BAMGs (10 in each group) were tested under tension, and the ultimate tensile strength, maximum strain, and elastic modulus were determined from stress/strain curves. RESULTS: Both types I and III collagen, as well as elastic fibres, were observed as major components of the matrix scaffold. There were more collagen type I fibres in the rat than in the pig and human BAMGs, whereas the pig, and particularly the human, both showed higher levels of type III collagen and elastic fibres. These different matrix scaffold patterns were confirmed by electron microscopy. Results from biomechanical testing showed no significant differences for strength, strain or elastic modulus between BAMG and control bladder strips, except in the rat where the maximum strain values were significantly lower. CONCLUSION: There are variations in the acellular matrix structure with similar biomechanical properties between the BAMG and the normal urinary bladder in three different species. These results may underscore the potential of the BAMG. Furthermore, this in vitro model provides a suitable method to study the mechanical properties of the urinary bladder and may serve as a diagnostic tool for various investigations.