Workshop in clinical anatomy for residents in gynecology and obstetrics.

A workshop in the clinical anatomy of the female pelvic viscera has been part of the training program for the first year residents in Gynecology and Obstetrics at the University of Padova since the 1999-2000 academic year. The purpose of the workshop is to offer a direct experience of practical anatomy despite a shortage of cadavers. It is designed for six residents who work in three teams on three specimens. The anatomical specimens are unembalmed, unfixed, female pelvic visceral blocs that are harvested from the cadavers 24 hr after death. They are stored at -12 degrees C and removed from the freezer 12 hr before the workshop. The workshop is 3 hr in length and has two parts: one on theory and one practical. In the theoretical section (30 min), the teacher presents the topographical anatomy of the specimens and the residents analyze a clinically oriented worksheet. In the practical section (2 hr), the residents identify viscera, vessels, and nerves through inspection and palpation, and then a step-by-step dissection is carried out. In the last section (30 min), the workshop includes presentations on the three specimens that illustrate anatomical variability and assess knowledge of topographical anatomy. For many residents, this is the first practical experience of the anatomy of the female pelvic viscera because the anatomical courses for medical students do not include direct dissection by students. The unfixed viscera preserves the natural characteristics of the different tissues that exhibit the aspects of living organs, such as color, softness, and pliability, enhancing the knowledge of anatomy. The worksheet is structured as a guide to the anatomical basis of physical examination through inspection and palpation of the viscera. It also introduces the residents to the surgical anatomy of the female pelvis through a brief and selective dissection focused on the relationship between the different regional systems.

A short course of dissection for second-year medical students at the School of Medicine of Padova.

A "Short course of dissection" was introduced in 1999 for the second-year medical students at the University of Padova. The course aims to offer a direct experience of practical anatomy despite a shortage of time for anatomy courses and lack of availability of cadavers. The course is optional and is planned for 40 students, subdivided into eight working groups. It consists of five sessions on the following topics: the viscera of the male pelvis; the viscera of the female pelvis; the kidney, the testis and spermatic cord; the thorax and abdomen; the brain. Each session lasts 3 hours and is organized as follow: (A) Theory: Teacher: concise review of the systematic and topographic anatomy of the selected topic (20 min); Students: analysis of a dissection guide (20 min). (B) Practice: Students: identification of the viscera and vascular and nervous structures, through inspection and palpation (15 min); step-by-step dissection following the worksheet (80 min); presentation of the visceral blocks as prosections under a closed-circuit telecamera (anatomical variability) (30 min); Teachers and students: three-dimensional conceptualization tests (15 min). At the end of the 2000 and 2001 courses, a questionnaire was administered to the students and the results confirm the usefulness of dissection for developing a three-dimensional knowledge of anatomy. In our opinion the main guidelines in planning a short course of dissection are: (1) selection of the topics, aimed at allowing experience of the gross anatomy of single viscera, fascia and serosa as well as the evaluation of the topographical relationships between parts of different systems including the local vessels and nerves; (2) preparation of a worksheet, presenting in 10-15 points concise instructions for the step-by-step progression from inspection to palpation and dissection of the anatomical structures of the visceral block; (3) direct dissection, brief and selective, by students; (4) clinical correlation; (5) motivational teachers, who stimulate the active involvement of students in "learning by doing" and also "learning how to do".

Monte Carlo model of nonlinear chromatography

A stochastic approach to the nonlinear chromatography theory, based on the Monte Carlo simulation method, is presented. A computer program, acting as a "virtual chromatograph" and performing a discrete event simulation, is described. Such a program allows one to choose the column type, operating conditions, sample composition, injection method, mobile-phase dispersion model, and stationary-phase sorption-desorption kinetics. Nonlinearity is accounted for by continuously monitoring and updating both the column and the solute status and by moving individual molecules step by step along the column according to specific random modes. The program has been validated through a series of statistical tests and comparing the results with the well-known achievements of the classical stochastic theory. A first application is presented, referred to a real case benzene elution on a gas solid capillary column, where the Langmuir adsorption isotherm is assumed. The effect of both the sorption modes and the site capacity are investigated. Possible applications to investigate open problems in several fields of separation science are emphasized. In addition, several specific points such as the down-scaling of a real case and the correspondence of specific adsorption dynamics with the equilibrium Langmuir isotherm are described.

Middle cerebral artery thrombosis following blunt head trauma.

Stroke caused by occlusion of an intracranial artery following blunt head trauma is a rare event. Traumatic dissections of the middle cerebral artery have been reported while thrombosis is very rare. We describe a case of fatal thrombosis of the left middle cerebral artery that occurred in the time interval between 2 and 6 hours after an apparently minor head trauma in a motor vehicle accident. The 25-year-old woman was in normal health on admission to the hospital. Two hours later the patient manifested nystagmus and vomiting. Six hours later she was aphasic with right hemiparesis. Twenty-four hours later the patient was comatose. A third CT scan performed at that time showed a wide infarct of the left cerebral hemisphere and a hyperdense left middle cerebral artery. The patient died 5 days after the collision. The autopsy confirmed the presence of the cerebral infarct and revealed thrombosis of the left middle cerebral artery. Microscopically, the transverse rupture of the intima and of the elastic lamina along the whole circumference of the vessel was found at the beginning of the thrombosed tract. We conclude that the blunt head trauma caused a partial rupture of the wall of the left middle cerebral artery with consequent thrombosis of the vessel and cerebral infarct. Based on the anatomy of the middle cerebral artery and on the review of the morphological literature we propose that the 2 types of lesion, the dissection and the thrombosis, that may follow closed head trauma, might depend on a common denominator that is the primitive rupture of the intima and elastic lamina.

Structural and ultrastructural changes in ileal neobladder mucosa: a 7-year follow-up.

OBJECTIVE: To investigate the long-term morphological changes in the intestinal segment used to create an orthotopic ileal neobladder. MATERIALS AND METHODS: Periodic endoscopy with biopsy of the ileal mucosa was performed in 90 patients 3-84 months after radical cystectomy and urinary diversion via an orthotopic neobladder. Three cold-cup biopsies were taken from each patient and mucosal specimens processed for light and electronic microscopy. RESULTS: Early changes (up to 1 year after surgery) comprised a marked shortening of the villi with loss of microvilli. After 4 years, the prevalent finding was of flat, avillous epithelium that tended to stratify in some areas. The avillous areas were mixed with islets of villous mucosa. There was no dysplasia or malignancy in any of the 90 patients. CONCLUSIONS: Prolonged contact with urine elicited a biphasic response in the ileal mucosa, i.e. an early inflammatory phase, ascribed to the noxious action of urine, followed by a regressive phase in which the epithelium tended to assume a morphology similar to the urothelium. The atrophic changes were almost totally completed after 4 years, although areas with marked modifications alternated with others where the morphology was normal, even many years after surgery. Late changes in the ileal neobladder mucosa appear to be an expression of a functional adaptation of the mucosa to the new environment.

Megalodolichobasilaris: the effect of atherosclerosis on a previously weakened arterial wall?

The morphological findings of 2 basilar artery giant fusiform aneurysms are presented. In one case (a 63-year-old man) the aneurysm was accidentally found at autopsy. Its wall was mainly formed by fibrous tissue without a smooth muscle layer and presented fragmented but still recognizable elastic lamina. In the media there were small well-formed bony spicules. In the other case (a 59-year-old man) the aneurysm had broken causing subarachnoid hemorrhage. The wall showed a marked reduction of smooth muscle cells and thinning and fragmentation of elastic lamina. A second sacciform aneurysm was present at the basilar tip. The review of the literature and the morphological findings of the 2 cases, characterized by abnormality of the portion of the basilar artery not directly involved in the aneurysm wall, consisting of a diffuse deficit of the tunica media and lamina elastica, might suggest that the fusiform aspect of the aneurysm may be the result of the degenerative effect of atherosclerosis on a cogenital, structural or dysmetabolic, or acquired, inflammatory, weakening of the arterial wall.

Anatomy of segmental duplication in the human basilar artery. Possible site of aneurysm formation.

Segmental duplications of the basilar artery, previously reported exclusively as anatomical variations, owe their clinical interest to the possible association with aneurysms localized at the junctions of the fenestrated segments. The morphological characteristics of 5 cases of basilar artery segmental duplication without aneurysms, found at autopsy, are reported. In 3 of these the proximal junction of the fenestrated segment was studied with scanning electron microscopy and morphometry. In all cases the tunica media of the medial wall of the 2 branches showed a progressive thinning towards the junctions of the fenestrated segments and a small muscular gap at their apex. The limited medial defect might be embryologically ascribed to the persistence of the morphological individuality of the tunica media of the 2 branches at the point where the fusion of the primitive longitudinal neural arteries stopped. The review of the literature shows that the morphology of the junctions of the fenestrated segments is in conformity with that of the intracranial arterial bifurcations. For this reason the basilar artery fenestration exposes to the blood flow a new distal bifurcation where the same etiologic factors that are still under discussion in the origin of saccular intracranial aneurysms may be active.

The persistent primitive hypoglossal artery: a rare anatomic variation with frequent clinical implications.

The case of a persistent primitive hypoglossal artery (PHA) in a 72-year-old man dead from myocardial infarction is presented. The autopsy showed the presence of a semicircular marginal infarct on the surface of the left cerebral hemisphere. The PHA anastomized the basilar artery origin with the left internal carotid artery, running through the left hypoglossal canal together with the hypoglossal nerve. The vertebral and posterior communicating arteries were hypoplastic. The PHA represented the morphological base on which the cerebral vascular insufficiency acted, following the generalized circulatory insufficiency due to the myocardial infarct, causing the cerebral infarct. Based on the embryology of the cranial arteries and on the morphological findings we suggest that the persistence of the hypoglossal artery: 1) precedes the vertebral and posterior communicating arteries hypoplasia causing it by competition for the territory of distribution; 2) gives rise to an almost complete dependence of the cerebral circulation from the carotid system with predictable ischemic consequences in the case of a critical reduction of the carotid blood flow; 3) may be associated with an anomalous structure of the vessel wall and exposes the basilar trunk to an unusual haemodynamic stress, predisposing to the onset of aneurysms.

The organization of subperitoneal connective tissue in the female pelvis.

The organization of the subperitoneal connective tissue in the female pelvis was studied in 6 cases, aged between 58 and 65, deceased from extrapelvic diseases. The pelvic viscera were removed as a whole with the surrounding subperitoneal tissue using a circular cut performed at the level of the pelvic walls. The specimens were fixed in 5% formalin. The bladder dome, uterine body and rectum, up to the anorectal junction, were removed. In two cases the specimens were dehydrated and embedded in paraffin. Ten micron sections were stained with Haematoxilin-Eosin and Azan-Mallory. In 2 other cases the specimens were plastinated according to Von Hagens E12 technique; the passage in acetone at room temperature lasted 24 hours. In the remaining 2 cases the plastination with E12 was carried out after a passage in acetone at room temperature which lasted about 15 days in order to fully remove the lipids from the subperitoneal adipose tissue. The morphological findings demonstrate that the subperitoneal tissue of the female pelvis has an areolar structure with small adipose lobules separated by thin fibrous laminae connected to the vasculo-nervous bundles and to the parietal and visceral layers of the fascia pelvica. The three dimensional spatial organization of the network of thin connective laminae constitutes an anatomical device with possible supporting properties.

Correlation of testicular volume, histology and LHRH test in adolescents with idiopathic varicocele.

Testicular growth failure as well as a well-documented histological damage have been reported in adolescents with varicocele. However, the proper management of this disorder in childhood is still debated due to the lack of seminal data and to the large number of adults with varicocele who have no fertility problems. In order to identify the subset of patients who are at risk of developing impaired testicular function and thus candidates for early varicocelectomy, we have studied 15 adolescents 10-17 years old with a grade II-III left-sided varicocele. Testicular volume and gonadotropin response to LHRH stimulation were evaluated preoperatively and compared to the histological findings from bilateral testicular biopsies. An abnormal left testicular histology was observed in 7 boys (46.6%) but only 3 of them (20%) showed severe testicular damage. The difference in size between the right and the left testis was never significant and was of no value in detecting subjects with abnormal histology. A good correlation was found between testicular injury and an increased response of both gonadotropins to the administration of LHRH. Decreased testicular volume does not seem to be a reliable predictor of early testicular damage. The assessment of gonadotropin response to LHRH may provide an additional objective means of evaluating adolescents with varicocele.

Fenestration of the vertebrobasilar junction.

A fenestration of the vertebrobasilar junction was found in an 80-year-old man during autopsy. It was associated with thrombosis of the vertebral arteries which had caused a left Wallenberg syndrome. The left limb of the fenestration presenting the same transverse diameter as that of the remaining part of the basilar artery appeared to be its direct (true) origin. The right limb had a lesser transverse diameter and appeared to bridge the lateral surface of the rostral end of the right vertebral artery and the basilar trunk. According to the authors, this fenestration could have been caused by the persistence of the cranial part of a primitive lateral vertebrobasilar anastomosis, rather then by the usual incomplete fusion of the primitive paired basilar arteries.

Anatomy of the optic nerve in elderly men.

The microscopic and ultrastructural modifications of glial and mesenchymal components of the optic nerve in the physiologic aging were studied in 182 human optic nerves. According to the age of subjects, a modification of topography of astrocytes was observed. In the 7th-8th decade, the axons of the optic nerve showed some phenomena of swelling and axonal degeneration. During the years, the central artery of retina showed an evident hyperplasia of intima and an increase of collagen of the media. While the connective tissue was good represented by the end of the 1st decade in the central vein of retina, the muscular tissue was almost absent. The interfascicular connective tissue increased considerably in the aging.

Congenital polyp of the prostatic urethra: report on 2 cases.

Congenital polyps of the prostatic urethra are an uncommon cause of obstructive uropathy, infection and/or hematuria in male children. A filling defect localized in the posterior urethra on the voiding cystourethrogram represents the peculiar diagnostic finding. Transurethral resection is the treatment of choice, according to the size of the polyp. Two cases of congenital posterior urethral polyps are reported and the main clinical and radiological features are discussed. This lesion has to be considered in the differential diagnosis of the voiding dysfunction in young boys.

[Mechanical responses on isolated frog neuromuscular preparations in the presence of calcitonin]. / Risposte meccaniche di preparati neuromuscolari isolati di rana in presenza di calcitonina.

Previous observations had shown that, in the isolated rat preparations, calcitonin facilitates the excitement transmission from autonomic nerve-endings to smooth muscle. The present research, was designed to verify whether this facilitation effect could be present in somatic nerve-endings too. For this reason, we used the isolated frog "sciatic nerve-gastrocnemius muscle" preparation where the calcitonin influence on the beginning of a complete tetanic response was studied. The motor nerve-endings were stimulated at different frequencies. It was observed that the added calcitonin and/or an increased [Ca++] medium induced a complete tetanic response also at stimulating frequencies that, in the controls, provoked only a clonic response. Moreover, both the calcitonin and the increased [Ca++] medium frequently induced an increase in the mechanical muscle tension developed. These facilitating effects were reduced or even abolished with inhibition of Ca++-passage through the cell membrane by nifedipine. Therefore, we could hypothesize that the added calcitonin causes increased Ach-release from the somatic nerve-endings and that this action depends on facilitated Ca++-passage through the cell membrane of the nerve-endings and of the muscle fibres too.