Spiral Course Research Articles

Variations in the cystic duct: frequency and the relationship among insertion sides and heights on the bile duct.

Evaluation of the cystic duct anatomy prior to bile duct or gallbladder surgery is important, to decrease the risk of bile duct injury. This study aimed to clarify the frequency of cystic duct variations and the relationship between them. Data of 205 patients who underwent cholecystectomy after imaging at Sada Hospital, Japan, were analyzed. The Chi-square test was used to analyze the relationships among variations. The lateral and posterior sides of the bile duct were the two most common insertion points (92 patients, 44.9%), and the middle height was the most common insertion height (135 patients, 65.9%). Clinically important variations (spiral courses, parallel courses, low insertions, and right hepatic duct draining) relating to the risk of bile duct injury were observed in 24 patients (11.7%). Regarding the relationship between the insertion sides and heights, we noticed that the posterior insertion frequently existed in low insertions (75.0%, P<0.001) and did not exist in high insertions. In contrast, the anterior insertion coexisted with high and never low insertions. Spiral courses have two courses: anterior and posterior, and anterior ones were only found in high insertion cases. The insertion point of the cystic duct and the spiral courses tended to be anterior or lateral superiorly and posterior inferiorly. Clinically significant variations in cystic duct insertions are common and surgeons should be cautious about these variations to avoid complications.

Integration of ultrasonography training into undergraduate medical education: catch up with professional needs

ObjectiveUltrasonography (US) has become the first-line imaging modality even for physicians who are not imaging specialists. The progress has not yet been sufficiently considered in medical education. The aim was to develop a curriculum that integrates US as a compulsory part into medical education directly from the start, to build up professional competencies toward residency.MethodsDevelopment was based on Kern’s six-step approach to identify problems, specify needs, define goals, outline strategies, and propose methods.ResultsThe proposed curriculum follows a spiral course within which students should pass through four levels of training with increasing complexity. Students will be asked to independently prepare for courses by using learning videos. On the first training level, US should be closely linked to anatomy and physiology courses. Competency-centered courses should be held in small groups. On the second level, in the third year of education, students will apply point-of-care ultrasonography concerning multiple medical disciplines. On the third level, they will select a compulsory course in a specialty of their choice, held at five consecutive dates. From then on, US will be conducted in patients. Finally, during the final year, students are expected to use US under pro-active supervision with a large degree of independence and confidence. Throughout the curriculum, the discipline of radiology combines vertically with foundational sciences and horizontally with other medical specialties.ConclusionThe conceptual proposal for a longitudinal US curriculum presented here has been developed by radiologists to equip students with competencies needed for contemporary patient care.

Keep up with progress-Ultrasound education requires change.

Despite increasing use of ultrasound imaging even beyond the circle of radiologists, low priority is given to student training. Until today, integration of ultrasound into clinical education at medical schools still lags far behind, and a curricular structure is oftentimes missing or implemented half-heartedly on a voluntary basis. Main reasons for not having ultrasound integrated are lack of time and poor funding. Finally, residents feel inadequately prepared for daily professional practice. For patient safety and satisfaction, however, it is highly desirable that ultrasound becomes second nature to the next generations of physicians, as the stethoscope already is.1 At our university hospital, we recently developed and implemented a multidisciplinary curriculum that integrates ultrasound as a compulsory part into medical education directly from start to finish. The curriculum follows a spiral course with four levels of training in which learning activities are repeated with continuously growing complexity. Competency-centred “probe-in-the-hand” courses are held in small groups of maximum six learners. Students start to practice ultrasonography by scanning each other, attending training in skills labs and, finally, deepen experience in clinical settings. Students should prepare self-determinedly for courses using learning videos available on the university's in-house network and on publicly available e-learning platforms. On the first training level, during preclinical education, ultrasonography is closely linked to anatomy dissection- and physiology courses. With this vertical integration, basic sciences are put into context and vice versa, clinical aspects are introduced into early medical training. At the same time, specific psychomotor skills are introduced. On the second level, in the third year of medical education, students apply point-of-care ultrasound in peers, skills lab simulations and ultrasound phantoms. The skills lab will be available during semester breaks to provide the opportunity to practice outside scheduled courses. On the third level, during advanced clinical education, students select a compulsory elective ultrasound course in a specialty of their choice, held at five consecutive dates following the concept of work-based learning. This allows students to direct their own learning and to focus on their preferred specialty. From then on, they conduct ultrasound examinations in patients. During the final year, students successively adapt skills and knowledge to growing medical experience. Now they are expected to use ultrasound with a large degree of independence and confidence. Entrustable professional activities are specified and assessed concomitantly. The longitudinal curriculum might serve as an inspiring example, however, with built-in flexibility according to requirements of each medical school and changing conditions. Incidental effects including enhancement of self-determined learning and mutual benefits regarding learning success in involved disciplines are expected. Costs and time can be saved by e-learning and appointment of student tutors. As participating departments share benefits arising from integration of ultrasound, they may contribute to the costs proportionally. In the interest of both patients and students, with an eye to the future, medical schools are encouraged to remove initial obstacles and tackle full and early integration of ultrasound into their curricula.

Ultrasound technologies in the diagnosis, treatment, and rehabilitation of children with testicular torsion

AIM: This study improves the diagnosis of testicular inversion in children to select different treatment strategies by determining the effectiveness of conservative and surgical testicular detorsion criteria.&#x0D; MATERIALS AND METHODS: The clinical data from 2010 to 2020 included 110 children with testicular torsion. In 64% of cases, the left testicle predominated. Testicular torsion occurred in 50% of children in the 12- to 14-year-old age group. The time from disease onset to seeking medical help ranged from 1.5 hours to 11 days. It was less than 6 hours in 41.8% of children, from 6 to 12 hours in 13.6% of boys, 12 to 24 hours in 11% of patients, and more than 24 hours in 33.6% of boys and adolescents. The protocol for the diagnosis, treatment and rehabilitation of all children included various techniques for ultrasound examination of the scrotal organs.&#x0D; RESULTS: The analysis showed the absence of reliable criteria for detecting testicle torsion in the early periods (61%100%): spiral course of the spermatic vessels (63.9%), change in the position of the testicle (19.8%), increase in the volume of the testicle and appendage (98.3%), a change in testicle shape and the inability to withdraw its poles (47.5%), and a hydrocele (67.2%). The index of false-negative results of the ultrasound scan of the scrotal organs reaches 40%. Conservative navigation detorsion was performed in 39 (35.5%) boys and adolescents during the early disease stages. The ultrasound criteria for the effectiveness of conservative detorsion were established. The main criteria normalized blood flow in the testis (100%). Surgical treatment of testicular inversion was performed in 71 (64.5%) boys and adolescents.&#x0D; CONCLUSIONS: Compliance with the protocol for diagnosing, treating, and rehabilitating children in different age groups with testicular torsion allowed us to determine adequate emergency treatment strategies and follow-up. An ultrasound differential diagnosis is performed with testicular hydatid torsion and inflammatory diseases of the scrotal organs. The informativeness of the ultrasound methods amounted to 60%.

Teaching Mechatronics to Non-traditional Mechanical Engineering Students – An Adaptive Approach

The mechanical engineering program at our university has adopted an integrated curriculum, with the first-two years based on multidisciplinary engineering foundation spiral courses across the college, and the last-two years following traditional mechanical engineering courses within the home department. This paper presents how we introduce the broad field of mechatronics to non-traditional mechanical engineering students via a single technical elective course. Students enrolled in mechatronics usually demonstrate a wide range in knowledge and skill preparation, especially in the areas of electronics, instrumentation, and programming. Such diversity of backgrounds, in addition to the breadth of topics typically associated with mechatronics, impose a great challenge to the design and delivery of the course. In this empirical investigation, we propose an adaptive approach to respond to the challenge. Two stages of adaptation are involved in this teaching approach. At the stage of course design, design-loop adaption is applied to restructure the course contents based on a starting point assessment. During the process of course delivery, task-loop adaption is implemented based on the dynamic assessment of student knowledge state. By replacing the common one-fixed-content-fit-all teaching approach to an adaptive one, we can engage the less prepared and less enthusiastic students while maintaining the interest of the majority in class. Qualitative analysis of the course evaluation results have shown that the adaptive teaching approach has achieved success in several dimensions. The most encouraging feedback lies in the fact that students’ interests in the broad field of mechatronics are greatly inspired by the course.

Complex Endovascular Aortic Repair with a Branch for an Intercostal Artery in Marfan Patient

Introduction: Spinal cord ischemia (SCI) caused by intercostal artery occlusion in combination with procedural factors such as hypotension is the Achilles heel of open and endovascular TAAA-repair report a case of branched endovascular aortic repair including a branch for a large intercostal artery as a protective method in a patient at risk for spinal cord ischemia (SCI). We report a case of branched EVAR (bEVAR) in a Marfan patient with a 6cm Type IV TAAA including a branch for a large previously re-implanted intercostal artery. Methods: A 43-year-old patient with known Marfan syndrome presented with a type IV thoraco-abdominal aortic aneurysm (TAAA) and history of multiple previous cardiac and aortic operations over the past 28 years. The maximum diameter of the aneurysm was 60mm. The patient had two right renal arteries and two re-implanted segmental arteries. With the goal to preserve both right renal arteries and one large intercostal artery a 6-branched custom-made stent-graft was planned and manufactured. A custom-made stent-graft (Cook Medical, Bjaeverskov, Denmark) was planned. The branched component was planned to land in the mid/distal descending thoracic aorta with antegrade branches for the CA, SMA and renal arteries and a retrograde branch on the opposite left side for the intercostal artery. The retrograde branch for the intercostal artery was positioned at 5:00 o'clock in order to allow a spiral course of the bridging covered stent to the origin of the vessel at 9:30 o'clock with a lower risk of kinking. Bilateral femoral and right brachial artery access was used. The intercostal artery was catheterized and connected to the retrograde branch from femoral access successfully. Results: Selective angiography of the target vessels and final angiography demonstrated good sealing and unimpeded branch-perfusion, without endoleak. The patient was discharged from hospital to home on postoperative day 10 without complications. Six-month-follow up CTA demonstrated unchanged well-fitting endo-graft-position with good sealing and patency of all six branches including the two branches on the right renal artery and the branch to the intercostal artery (Figure. 5). The TAAA-diameter had significantly decreased from 60mm to 42mm and no signs of endoleak were present. Conclusion: Branched endovascular aortic repair with a branch to a large intercostal artery was technically feasible and clinically successful. Disclosure: Tilo Kölbel has intellectual property with Cook Medical, receives royalties, research, travel and educational grants, speaking fees and is consultant and proctor with Cook Medical. Nikolaos Tsilimparis receives travel and educational grants, speaking fees and is proctor with Cook Medical.

Two-dimensional speckle-tracking echocardiographic evaluation of the longitudinal deformation of the left ventricular myocardium in patients with severe coronary artery tortuosity.

Coronary artery tortuosity (CAT) is an anatomical condition in which epicardial coronary arteries have abnormal curves or spiral courses. Although correlated with higher rates of positive stress test, its effects on the myocardial function remain to be clearly defined. We included in this cross-sectional study and evaluated with 2D speckle-tracking echocardiography 40 consecutive patients admitted to our hospital for selective coronary angiography which showed severe CAT without significant epicardial coronary artery stenosis, and 40 consecutive subjects matched for age, hypertension, and diabetes in whom selective coronary angiography showed neither CAT nor significant epicardial coronary artery stenosis. Systolic strain, strain rate, and early and late diastolic strain rates were not significantly different between the 2 groups, even after adjustment for potential confounding variables. The 2D speckle-tracking echocardiography-derived indices of longitudinal deformation of the left ventricular myocardium were not significantly different between the patients with severe CAT and controls.

Nerve length measurement method in a radial motor nerve conduction study

Background Previous studies of radial nerve conduction study (NCS) did not present how to measure the length of the radial nerve across the elbow, and did not even mention how to manage the spiral course of the nerve. This study aimed to applicate the most reliable method to measure the length of the radial nerve during NCS. Methods Three points (A, B, and C) were determined along the relatively straight course of the radial nerve. The distance was measured using three different methods: L1) straight distance corresponding to the A-C distance, L2) sum of the distances corresponding to the A-B-C distance, L3) based on the L2, but the elbow is flexed at a 45° angle. We compared the three methods of distance measurement and the calculated nerve conduction velocities (V1, V2, and V3) in normal healthy subjects. Results 19 normal participants were enrolled. The mean value for method L1, L2 and L3 were 22.5 ± 1.8 cm, 24.0 ± 2.1 cm, and 23.2 ± 2.1 cm (p < 0.001). Calculated conduction velocities using those distance measurement methods as follows (p < 0.001): V1 (60.9 ± 2.7 m/s), V2 (64.6 ± 3.3 m/s), and V3 (63.4 ± 3.9 m/s). V2 was significantly greater than V1 and V3 (p < 0.001, p = 0.010, respectively). Conclusions The distance measurement using a stopover point near the lateral epicondyle between two stimulus points in position of a fully extended elbow with forearm pronation is the most appropriate posture for radial motor NCS.

Umbilical Coiling Index and Perinatal Outcome

&lt;strong&gt;Objective(s):&lt;/strong&gt; To study the association of umbilical coiling index and perinatal outcome. &lt;strong&gt;Method(s):&lt;/strong&gt; One hundred and eighty five umbilical cords were examined. A coil is defined as a complete 360 degree spiral course of umbilical vessels around the Wharton's jelly. UCI was calculated by dividing the total number of coils by the umbilical cord length in centimeters. The outcomes measured were in terms of IUGR, fetal heart rate abnormalities during labor, meconium stained amniotic fluid, number of assisted deliveries was required, NICU admission, FSB, birth weight, ponderal index, various maternal medical illnesses. Hypocoiling was considered with UCI less than the 10th percentile and hypercoiling was considered UCI greater than the 90th percentile. Statistical analysis was done by Chi-square test, Fischer's exact test and the t-test where ever applicable. &lt;strong&gt;Results:&lt;/strong&gt; The mean UCI in our study was found to be 0.19 + 0.08. 82.7% of the cords were normocoiled whereas 8.6% cords were hypocoiled as well as hypercoiled each. UCI below 0.09 was hypocoiling and above 0.26 was hypercoiling. In this study we found that PIH, IUGR, intrapartum FHR abnormalities, MSAF, increased instrumental deliveries, low APGAR scores, NICU admission, low birth weight and ponderal index were significantly associated with hypocoiling (P&amp;lt;0.05). IUGR and NICU admission were significantly associated with hypercoiling too (P&amp;lt;0.05). &lt;strong&gt;Conclusion:&lt;/strong&gt; Our study thus shows that abnormal umbilical coiling index is associated with adverse perinatal outcome.

Morphogenesis of the inner ear at different stages of normal human development.

This study examined the external morphology and morphometry of the human embryonic inner ear membranous labyrinth and documented its three-dimensional position in the developing embryo using phase-contrast X-ray computed tomography and magnetic resonance imaging. A total of 27 samples between Carnegie stage (CS) 17 and the postembryonic phase during trimester 1 (approximately 6-10 weeks after fertilization) were included. The otic vesicle elongated along the dorso-ventral axis and differentiated into the end lymphatic appendage and cochlear duct (CD) at CS 17. The spiral course of the CD began at CS18, with anterior and posterior semicircular ducts (SDs) forming prominent circles with a common crus. The spiral course of the CD comprised more than two turns at the postembryonic phase, at which time the height of the CD was evident. A linear increase was observed in the length of anterior, posterior, and lateral SDs, in that order, and the length of the CD increased exponentially over the course of development. Bending in the medial direction was observed between the cochlear and vestibular parts from the latero-caudal view, with the angle decreasing during development. The position of the inner ear was stable throughout the period of observation on the lateral to ventral side of the rhombencephalon, caudal to the pontine flexure, and adjacent to the auditory ganglia. The plane of the lateral semicircular canal was approximately 8.0°-14.6° with respect to the cranial caudal (z-)axis, indicating that the orientation of the inner ear changes during growth to adulthood.

Parameters influence on maneuvered towed cable system dynamics

The dynamic response of a towed cable system to ship maneuver is parametrically simulated. Three dimensionless parameters influence on towed cable system maneuverability is investigated. They are ratio of total length to turning radius R/L, ratio of cable mass to vehicle mass σ, and ratio of mass unit length to hydrodynamic force w/r. An oscillatory motion of towed vehicle is found in simulation of spiral towed courses. Features of this oscillation in different spiral courses are compared. The sharp turns, gradual turns and their transient states of towed cable dynamics for different course directions are discussed extensively. According to the characters of transient states and horizontal trajectories evolution of maneuvered cable system, the dynamic behaviors can be divided into three situations in Fig. 8 turning maneuvers. The behavior of towed cable system during a zigzag turning course is simulated in the end. Two ingredients of heave motion are found during small ratio of turning radii to length in this course. The primary damp to initial turning becomes weak and the response to alternative turns plays a more and more important role. The damping properties of the transient behavior in different maneuvers show a periodical invariance to σ during some turning maneuvers.

Hurricane-based Optimization Algorithm

This paper introduces a new meta-heuristic optimization technique called Hurricane-based Optimization algorithm (HOA). The underlying concepts and ideas behind the proposed method are inspired from nature and based on the observation of hurricanes, radial wind and pressure profiles. In HOA, wind parcels move in a spiral course outward from a low-pressure zone called the eye emulating hurricanes in the real world. During this process, wind parcels search for a lower pressure zone (new eye), which is considered as the optimal solution. The HOA is tested with several benchmark functions frequently used in the area of optimization. The obtained results exhibit the high performance of the proposed method.

Intrarenal smooth muscle: Histology of a complex urodymamic machine

ObjectiveTo know better the microscopic arrangement of the bundles of smooth muscle in the human renal parenchyma, its distribution and anatomical relationships, trying to make a reconstruction of this muscular system. MethodsFive adult human kidneys and one fetal kidney were processed “in toto” with cross sections every 300μm. In the histological sections we identify the smooth muscle fibers trying to determine its insertion, course and anatomical relationship with other structures of the kidney tissue. ResultsThere are bundles of smooth muscle fibers of variable thickness parallel to the edges of the medullary pyramids, bundles that surrounding the medulla in a spiral course, and bundles that accompany arcuate vessels, the latter being the most abundant and easy to identify. These groups of muscle fibers do not have a precise or constant insertion site, their periodicity is not homogeneous and they are not a direct extension of the muscle of the renal pelvis, although some bundles are in contact with it. There are also unusual and inconstant small muscle fibers not associated to vessels in the interstitium of the cortex and, exceptionally, in the medulla. ConclusionThere is a complex microscopic system of smooth muscle fibers that partially surround the renal medulla and are related to renal pelvic muscles without a direct continuity with them. Although this small muscular system is under-recognized, it could be very important in urodynamics.

Músculo liso intrarrenal: histología de una compleja máquina urodinámica

ObjectiveTo know better the microscopic arrangement of the bundles of smooth muscle in the human renal parenchyma, their distribution and anatomical relationships, trying to make a reconstruction of this muscular system. MethodsFive adult human kidneys and one fetal kidney were processed “in toto” with cross sections every 300μm. In the histological sections we identify the smooth muscle fibers trying to determine its insertion, course and anatomical relationship with other structures of the kidney tissue. ResultsThere are bundles of smooth muscle fibers of variable thickness parallel to the edges of the medullary pyramids, bundles that surrounding the medulla in a spiral course, and bundles that accompany arcuate vessels, the latter being the most abundant and easy to identify. These groups of muscle fibers do not have a precise or constant insertion site, their periodicity is not homogeneous and they are not a direct extension of the muscle of the renal pelvis, although some bundles are in contact with it. There are also unusual and inconstant small muscle fibers no associated to vessels in the interstitium of the cortex and, exceptionally, in the medulla. ConclusionThere is a complex microscopic system of smooth muscle fibers that partially surround the renal medulla and are related to renal pelvic muscles without a direct continuity with them. Although this small muscular system is under-recognized, could be very important in urodynamics.

Renal allograft function not impacted by extensive aortic dissection.

A 63-year-old hypertensive male underwent renal transplantation from his nephew in 2005. In 2007, he was diagnosed with aortic dissection—Stanford type A and B with aortic aneurysm. He had resection of the aortic aneurysm and replacement of the ascending aorta with a hemi-arch graft with left coronary artery implantation. In January 2010, he presented with chest pain, fever and malaise. Blood pressure was 107/73 mmHg and pulse 96/min and the femoral, anterior tibial, posterior tibial and dorsalis pedis artery pulses were palpable bilaterally. Computed tomography (CT) chest scan showed left pleural effusion. Diagnostic pleural tap was bloody and positive for Mycobacterium tuberculosis by polymerase chain reaction. Blood urea was 21 mg/dL, creatinine 1.2 mg/dL, haemoglobin 10.7 g/dL, WBC 11 800 mm3, platelet count 173 000 mm3, total protein 6.3 g/dL, albumin 2.9 mg/dL, electrolytes normal and troponin-I 0.031 ng/mL. Maintenance immunosuppressives used were prednisone 5 mg OD, mycophenolate mofetil 500 mg BD and rapamycin 1 mg OD. Other medications used were isoniazid 300 mg OD, pyrazinamide 750 mg BD, rifampicin 450 mg OD, levofloxacin 500 mg OD and vitamin B6 20 mg OD. CT angiogram showed normal ascending aorta with previous aortic repair. Dissection originated distal to left subclavian artery with dense contrast-filled false lumen and poorly filled true lumen. The dissection had a spiral course extending up to proximal segments of the iliac arteries (Figure 1). The abdominal aortic segment was not dilated. The origin of the artery for the transplant kidney and visceral arteries was the true lumen. The false lumen extended up to the left common iliac artery (Figure 2). This patient, with an unusual presentation of aortic dissection, and probably with a leaking aneurysm due to an infective pathology caused by Mycobacterium tuberculosis, had good allograft function as the transplant renal artery originated from the true lumen of the right common iliac artery maintaining adequate perfusion. He continues to have a good graft function 4 months later. Fig. 1 Dissection extending up to iliac arteries. Fig. 2 Transplant kidney and the vascular supply. Conflict of interest statement. None declared.

Rheotactic Macaronichnus, and Human and Cattle Trackways in Holocene Beachrock, Greece: Reconstruction of Paleoshoreline Orientation

Macaronichnus segregatis occurs in an upper foreshore conglomeratic to sandy beachrock dating from Roman times, on the east coast of Rhodes, Greece. In some laminae, M. segregatis is strongly oriented perpendicularly to the Recent and Holocene seashore. In other laminae, this trace fossil displays a winding to spiral course. These forms are introduced as new ichnosubspecies, M. segregatis lineiformis, M. segregatis maeandriformis and M. segregatis spiriformis, respectively. It is suggested that these middle-tier trace fossils were produced under conditions of different porewater flow. During higher energy periods, predominantly in winter, water movement perpendicular to the coastline caused M. segregatis to be oriented rheotactically. During periods of more or less stationary pore-water, predominantly in summer, M. segregatis assumed a spiral form. The winding form represents intermediate conditions. Closely beneath the Macaronichnus horizons a large burrow fill was found, probably referable to Psilonichnus isp. In the same beachrock are undertracks attributed to artiodactyls, associated with tracks and a trackway of human origin. The anatomy of the tracks indicates the direction of travel of the trackmakers, eastward and westward along-shore in all cases but one. The morphology of the tracks has been influenced by the gravitational effect of beach slope. Orientation, morphology and structure of trace fossils provide clear evidence that the sandstone and gravel unit is a beachrock and reveal the precise orientation of the paleoshoreline.

Spiral Blue practical procedures course

The practical procedures course is suitable for doctors at all levels who want to learn how to perform practical procedures in a supportive and relaxed environment. I did the course as a foundation year 2 doctor. Despite my eagerness to learn, I have found few opportunities to practise procedures such as inserting central lines and chest drains. This is partly because shifts are shorter than before, but also because so many jobs must be done in the working day that there is no opportunity to be supervised. Also, I have often …

The extracellular matrix of the human aortic wall: Ultrastructural observations by FEG-SEM and by tapping-mode AFM

Fragments of human ascending aorta harvested during heart surgery were cryofractured and observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Elastic fibers appear as irregular, undulated laminae of variable size and shape. Their surface shows an evident fibrous texture suggestive of a criss–crossed, delicate filamentous scaffold and is marked by a number of features such as ridges, holes and protruding ribs. At higher magnification, both SEM and AFM show the surface composed of a finely granular material, with a bead size of approximately 20 nm. However, the thickness of the metal coating in one case, and the tip convolution effect on the other, may equally result in an artifactual enlargement of the structures, so that the beads may be significantly smaller. The surfaces created by the fracture always appear smooth and compact and with this technique do not reveal significant detail. The collagen component is mostly represented by small, uniform fibrils gathered in flexuous bundles and following a wavy course not unlike that of the elastic laminae. An orthogonal lattice of small proteoglycans is readily evident even without a specific treatment. Occasionally, the fibrils appear encrusted or engulfed in a grainy matrix reminiscent of the elastic fiber surface. Fluid Tapping-Mode Atomic Force Microscopy simultaneously reveals the surface-bound proteoglycans and the inner architecture of the fibrils, composed of smaller subunits following a spiral course with a winding angle of approximately 17°.

Three-dimensional reconstruction of Haversian systems in ovine compact bone.

Haversian systems or secondary osteons are an integral component of compact bone. However, as their exact shape is debatable, this study describes a technique to view their morphology in three dimensions. Bone remodeling in adult ovine long bones was labelled at intervals using a series of chelating fluorochromes. A series of longitudinal sections were cut at 25 microm intervals through blocks of the distal radius embedded in methylmethacrylate using a sledge macrotome. The chelating agents were used as markers of bone formation in the study of bone growth and osteon morphology. The two-dimensional image of each section was examined using an epifluorescence microscope. Images were transferred to a PC via a CCD low light colour video camera. Surface reference points were noted on each of the sections and, using computer software, a three-dimensional image of a refilling labelled osteon was reconstructed and its dimensions measured. Haversian systems may have a gentle spiral course along the longitudinal axis of the bone. They intertwine with adjacent osteons and give multiple branches along their course producing a complex pattern of organization. The mean labelled length and diameter of the osteons was 1.4 + 1 mm and 145 + 0.42 microm [Mean + S.D], respectively.

The surgical anatomy of the fasciae and the fascial spaces related to the rectum.

The perirectal fasciae and their vascular and neural relationships were studied based on the dissection of 46 fresh cadavers. The rectal fascia is a tubular sleeve, areolar in nature, which houses the superior rectal vessels and lymphatics. The nerves which supply fibres to the pelvic plexus run close to the rectum, contained in the urogenital and presacral fasciae. The rectum is attached to these two fasciae by the rectal stalks, which take a spiral course round the rectum, being posterolateral in the upper rectum, lateral in the mid-rectum and anterolateral in the lower rectum. During rectal resection the pelvic nn. may be preserved if the rectal dissection proceeds close to the rectal fascia. After cutting the rectal insertion of the presacral fascia, the lower rectal stalks (paraproctium) come into direct view and can be divided close to the rectal wall with no risk of damage to the pelvic plexus.