摘要:

AbstractThe gubernaculum, innervated by the genital branch of the genitofemoral nerve, plays an important role in inguinoscrotal testicular descent. Cremaster muscle develops within the gubernaculum, and it has been demonstrated that an intact nerve is essential for gubernacular migration and scrotal pouch formation. In this electron microscopy study, we investigated the relationship between the gubernaculum, cremaster muscle, and the developing scrotum in normal rats and rats rendered cryptorchid by genitofemoral nerve division.In 12 neonatal rats, the genitofemural nerve was divided unilaterally. Rats were sacrificed at 2, 4, 7, 10, 14, and 18 days (n = 2 for each group), and sagittal sections through the cremaster muscle‐scrotal interface evaluated with transmission electron microscopy. These were compared to non‐operated control animals sacrificed at 0, 2, 4, 7, 10, 14, and 18 days (n = 2 for each group). We observed the following changes in the cremaster muscle of the operated group compared to unoperated controls: (1) an increase in the number of immature muscle fibers; (2) variable muscle fiber size; (3) disorganization of internal structures; and (4) vacuolization within the muscle fibers. There were no demonstrable ultrastructural interface or scrotal ligament differences between the operated and unoperated specimens.This study suggests that architecturally normal early gubernacular and cremaster muscle growth is dependent on an intact genitofemoral nerve. The poor scrotal growth seen without genitofemoral nerve input may be due to attachment of the scrotal ligament in an ectopic location in combination with abnormal cremaster muscle development. © 1994 Wiley‐Lis

ISSN:0897-3806    

DOI:10.1002/ca.980070502

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThis experimental study was undertaken to identify the surface and internal stress distribution and load transmission in menisci under different loading states using a three‐dimensional photoelastic method. These studies were carried out in four series of loading tests on models of menisci. Our observations showed that the stresses of the medial and lateral menisci were concentrated at the central strip of the menisci and that the magnitude of stresses on the superior surfaces of the menisci were greater than that on the inferior surfaces. The load bearing capacity of the lateral menisces where greater than that of the medial one. The results also showed that a complex apparatus, composed of the menisci and other associated structures surrounding the knee joint, plays an important role in the course of force transmission. In addition, the cause of meniscal splitting and the experimental method are discussed. © 1994 Wiley‐Liss,

ISSN:0897-3806    

DOI:10.1002/ca.980070503

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThe latissimus dorsi muscle (LD) has been the subject of numerous studies, especially because of its variety of possible applications in plastic and reconstructive surgery.The clinical use of functional electrical stimulation (FES) and cardiomyoplasty has raised completely new questions in recent years. It was the aim of our study to find an optimal model for animal experiments for this cardiosurgical method, in which the LD is completely removed from its origin and transferred into the thorax. For this purpose, we compared the LD's arterial supply in animals used in experimental surgery, the sheep, dog, and pig, with the LD's supply in human.For studying the arteries of the LD macroscopically and by X‐ray, we used an injection solution of latex and barium sulfate. After injection of the solution the vascularization was photographically documented. Subsequently, the muscle was detached from the neurovascular pedicle and prepared for radiological examination of the arterial vascularization.The planimetric computer‐assisted identification of the various areas supplied by arterial branches was based on these radiograms. In order to also assess the weight of the supplied parts, the muscles were gravimetrically analyzed.The study showed that the blood supply in pig is very similar to that of man. This species, therefore, would be best suited for experimental cardiomyoplasty. © 1994 Wiley‐Lis

ISSN:0897-3806    

DOI:10.1002/ca.980070504

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractFifteen consecutive patients having open heart surgery using retrograde cardioplegia were studied to demonstrate that important venous collateralization exists between the coronary sinus (CS) and its left ventricular branches and the right ventricle (RV). The venous collateralization makes possible RV myocardial protection during retrograde cardioplegia. Right ventricular venous drainage principally occurs via anterior cardiac veins, which drain into the right atrium, and thebesian veins, which drain into both the RV and the atrium, generally without connection to the CS. Retrograde cardioplegia used during open heart surgery should, therefore, give inadequate myocardial protection to the RV. Two RV temperature probes used as markers for RV perfusion were monitored continuously during cardiac arrest. Systemic temperature while on cardiopulmonary bypass was 25°C, and the retrograde perfusate solution temperature was 4°C. Coronary sinus pressure during the bypass procedure was maintained between 20 torr and 50 torr. Mean temperatures at the two probe sites were 16.1°C and 14.5°C. We conclude that a complex network of venous collaterals between the coronary sinus and left ventricle and the right ventricle allow excellent myocardial protection during retrograde cardioplegia. © 1994 Wiley‐Lis

ISSN:0897-3806    

DOI:10.1002/ca.980070505

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractDeep to the extensor expansion of the interphalangeal and metatarsophalangeal joints of the toes, there exists a structure of dense irregular connective tissue that corresponds to the opposite volar plate. This plate is a constant finding, is meniscoid, and challenges previous descriptions of the anatomy and function of these joints. © 1994 Wiley‐Liss, I

ISSN:0897-3806    

DOI:10.1002/ca.980070506

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractOpinions about the presence of a bandlike structure or a ligament in the lateral part of the temporomandibular joint capsule are divergent. In an attempt to find a definition for this structure, the capsules of 20 post mortem human specimens were examined both anatomically and histologically. The density of collagen tissue was investigated in detail with the aim to establish characteristics by which a structure can be classified objectively as a ligament.While there is still some uncertainty about its masticatory function, the lateral (temporomandibular) ligament influences and limits the border movements of the mandible. The macroscopic investigations showed that 70% (14) of the temporomandibular joints exhibited an obvious ligament. In the rest of the cases (6) only a thin, indistinct structure could be observed. In those with macroscopically obvious ligaments, 35.7% (5) were characterized by sharp borders forming a cord‐like structure.The histological observations did not confirm in all cases the findings of the macroscopic investigations. Only 57% of the macroscopically identified ligaments could be classified as such histologically. They were formed of thick, closely packed, parallel collagenous bundles with a regular pattern.This study confirms the variable existence of a lateral ligament in the human TMJ. © 1994 Wiley‐Liss,

ISSN:0897-3806    

DOI:10.1002/ca.980070507

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractTranspedicular screw fixation is a widely used method in vertebral surgery, but it suffers from complications due to mismatches between the screw and pedicle. Therefore, information on the real minimal diameter of pedicle is needed for the development of instrumentation techniques and implantable devices. A total of 4,212 measurements from 1,404 pedicles of 702 human vertebrae were made from thoracic (T11, T12) to lumbar (L1–L5). We found that there was a real minimal diameter which was different from the vertical and transverse diameters of pedicles. This is the smallest diameter which cannot be definitely determined by the imaging methods currently in use, such as anteroposterior and lateral radiographs, and computed tomography; direct measurements excepted. Based on these results, we suggest that neither vertical nor transverse diameter gives accurate measurements of minimal diameter. However, minimal diameter size may be estimated using the ratio of vertical or transverse diameter to minimal diameter reported in this study for each level. © 1994 Wiley‐Liss,

ISSN:0897-3806    

DOI:10.1002/ca.980070508

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractAs a component of a recent academic review, the Department of Anatomy and Neurosciences faculty at the University of Texas Medical Branch in Galveston, Texas, developed a questionnaire designed to compare the curricula, direction, and challenges of their department with the approximately 140 anatomy departments in the U. S. and Canada. The response was overwhelming in that over 80% of the schools returned a completed questionnaire. One of the areas of interest revealed by this survey was a growing concern over significant changes in both medical school curricula and the future of anatomy departments. Most departments still used traditional lectures to present course material and the majority of the scheduled contact hours were in the dissection laboratory; however, other teaching formats, such as case studies and small group discussions, accounted for significantly more of the teaching effort. Nearly 20% of the schools were making major modifications in their teaching methods. The general trend was to include more integrated, problem‐based learning and computer‐assisted teaching while reducing overall content, didactic lectures, and rote memorization. The role and need for traditionally trained gross anatomists in medical education appeared to be diminishing as curricular reform moved toward more student‐directed, faculty‐facilitated programs. Concurrently, the recruitment and career development of gross anatomy faculty appeared to be influenced more by funding status than by academic training or teaching experience, as most departmental chairman were willing to hire non‐anatomists and “train” them to assume an often reduced teaching load in gross anatomy courses. In addition, fewer graduate students were being trained in classical gross anatomy, a trend that better suited the emerging student‐directed medical school curricula. The reduction in classically trained anatomists also appeared to reflect the widespread practice whereby anatomy faculty were rewarded far more for research than for teaching. Although the continued inclusion of gross anatomy in medical education appeared to be assured, its traditional mode of presentation and academic prominence will likely change by the turn of the century. © 1994

ISSN:0897-3806    

DOI:10.1002/ca.980070509

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

摘要:

AbstractThis article, based upon a survey distributed to general practitioners in Switzerland, is part of a comprehensive work directed toward the development of a medical curriculum based on the specific requirements of primary health care. Analysis shows that it is possible to make a reduction in the amount of anatomy taught without endangering the basic knowledge necessary for clinical practice. © 1994 Wiley‐Liss, I

ISSN:0897-3806    

DOI:10.1002/ca.980070510

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY

ISSN:0897-3806    

DOI:10.1002/ca.980070511

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1994

数据来源: WILEY