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Biomedical subjects

R De Caro

Publications and source records attributed to R De Caro.

At least 19 recordsLinked to original sources
PubMed2006

Persistence of embryonic pattern of hepatocaval venous junction and patent ductus venosus in Budd-Chiari syndrome.

We report an autopsy study on a case of Budd-Chiari syndrome (BCS) in a 44-year-old woman. Dissection showed that the outlets of the right hepatic vein (HV) and of the common trunk of the middle and left HVs appeared as two small depressed areas with narrow ostia. Histological examination showed recent thrombosis of the tributaries of the HVs and centrilobular congestion with necrosis of the hepatic parenchyma. The juxtacaval portions of the major HVs showed a cuneiform shape, because of marked dilation, with thread-like ostia, and multiple small outlets of minor hepatic veins were also present. The coexistence of patent ductus venosus may have prevented the development of the hepatocaval venous junction, with persistence of the embryonic pattern, composed of multiple small channels draining into the right hepatocardiac channel. The unusual hepatocaval venous junction may have predisposed to thrombosis of the HVs, causing BCS.

Adult↗
PubMed2005

Morphogenesis of the posterior inferior cerebellar artery with three-dimensional reconstruction of the late embryonic vertebrobasilar system.

The posterior inferior cerebellar artery (PICA) shows the most variable course among the cerebellar arteries, mainly at the level of the lateral medullary segment. Based on the correlation between the level of origin and the characteristics of the lateromedullary segment, we have proposed three patterns of course of the PICA. With the aim of understanding their embryological basis we review the interrelations between the developing cerebellum and the primitive hindbrain arterial plexus through the analysis of transverse serial sections of human embryos of 22.5 and 23 mm crown-rump length. Three-dimensional reconstruction of the vertebrobasilar system has been performed to study the morphology of the vascular networks. The cerebellar primordium is vascularized by the metencephalic plexus that will form the basilar artery and the superior cerebellar arteries. Due to the development of the pontine flexure the rhomboid lips approach and the cerebellum comes into contact with the myelencephalon; thus the myelencephalic plexus represents an acquired source of vascularization for the cerebellum with respect to the metencephalic plexus. The examination of the transverse sections shows that the vertebral and basilar arteries, superior cerebellar arteries, anterior inferior cerebellar arteries, and primitive lateral vertebrobasilar anastomoses are well recognizable. The three-dimensional reconstruction of the vessels shows that the PICA is not yet defined due to the persistence of a plexus of many thin vessels at the level of the lateral aspect of the myelencephalon, indicating that its origin and course are established at the end of the embryonic period. Based on the evolution of the primitive hindbrain plexus, we suggest that in synchrony with the progressive descent of the cerebellum the branches of the myelencephalic plexus succeed with a rostrocaudal progression in feeding the cerebellum and the morphogenesis of the PICA results from the selection of portions of this plexus. The high origin of the PICA from the basilar artery could be ascribed to its development from a rostral collateral of the plexus due to an early development of the vessel at the beginning of its embryonic lifetime. Moreover, the three patterns of course of the PICA could reflect the variable retention of the primitive lateral vertebrobasilar anastomosis in the trunk of the definitive PICA, which may be related to its level of origin.

Arteries↗
PubMed2005

Histopathology of carotid body in heroin addiction. Possible chemosensitive impairment.

AIMS: To perform a morphometric analysis of carotid bodies in opiate addicts. METHODS AND RESULTS: Carotid bodies were sampled at autopsy from 35 subjects who died of heroin intoxication (mean age 26 years), and from eight young (22 years) and eight older subjects (66.5 years) who died of trauma. Sections were stained with haematoxylin-eosin, azan-Mallory, and double-labelling immunohistochemistry with antineuronal specific enolase and anti-S100, to count type I and type II cells. Interlobular and intralobular connective tissue was increased both in the opiate cases (43.45 +/- 6.79%, P < 0.001, and 13.34 +/- 5.72%, P < 0.001, respectively) and older cases (46.67 +/- 1.65%, P < 0.001, and 9.62 +/- 2.11%, P < 0.05, respectively) compared with young cases (33.17 +/- 6.41% and 4.33 +/- 1.84%, respectively). The percentage of type II cells in the opiate cases (51.6 +/- 7.3%, P < 0.001) and in the older controls (49.0 +/- 7.2%, P < 0.01) was higher than in the young cases (37.9 +/- 3.0%). Among type I cells, the light cell percentage in the opiate cases (65.85 +/- 11%, P < 0.001) was reduced with respect to the two control groups (82.8 +/- 5.34%, young; 81.62 +/- 8.58%, older). CONCLUSIONS: The increases in connective tissue and type II cells are similar to findings in ageing and chronic pulmonary disease, and may be ascribed to glomic hypoxia. A direct action of opiates should be taken into account for the decrease in light cells in heroin addiction. The histopathological changes in the carotid body, by impairing chemosensivity, may play a role in the fatal cardiorespiratory derangement of heroin addicts.

Adult↗
PubMed2004

Parapharyngeal ectopic thyroid: the possible persistence of the lateral thyroid anlage. Clinical case report.

The accessory midline thyroids are ascribed to an arrest of migration of the median thyroid anlage, while the lateral ectopic thyroids have induced a hypothesis of the presence of lateral thyroid anlage. We report the case of a 67-year-old man who presented with dyspnea and dysphagia of 1 year's duration. The clinical examination and radiological investigations (CT and MRI) showed a solid heterogeneous mass in the right parapharyngeal space. The fine needle aspiration biopsy was inconsistent. The mass (3x2.5x3.5 cm) was excised via a transoral approach. It was capsulated with an elastic consistency and showed a nodular appearance on the cut surface. Histological examination revealed thyroid tissue with the characteristics of colloid goiter. The postoperative (99m)Tc-pertechnetate scan showed the normal thyroid gland located in the usual pretracheal site. The absence of malignancy, at histology and immunohistochemistry, allows a metastatic nature of the mass to be ruled out, and accounts for a supernumerary thyroid. The occurrence of a parapharyngeal thyroid, although extremely rare, is worth bearing in mind as a possible ectopic location. This case also supports the hypothesized role of the lateral thyroid anlage in man deriving from the ultimo-branchial body in the morphogenesis of the lateral lobe of the thyroid gland.

Aged↗
PubMed2004

Imaging of primary sclerosing cholangitis: preliminary results by two new non-invasive techniques.

BACKGROUND: Magnetic resonance cholangiography is a new technique which has already gained a role in primary sclerosing cholangitis. Computerised tomographic cholangiography is another non-invasive technique which has been used in assessing abnormal biliary tree, but has never been applied to evaluating primary sclerosing cholangitis. AIMS: To evaluate the ability of both magnetic resonance cholangiography and computerised tomographic cholangiography to detect bile duct changes in primary sclerosing cholangitis. PATIENTS AND METHODS: Magnetic resonance cholangiography and computerised tomographic cholangiography were performed in 16 primary sclerosing cholangitis patients. The computerised tomographic cholangiography data set was transferred to a processing workstation to obtain tridimensional reconstructions. Magnetic resonance cholangiography and computerised tomographic cholangiography images were analysed blind by two radiologists to assess: primary sclerosing cholangitis involvement, quality of imaging and the radiologist's certainty in determining the presence and location of the disease. RESULTS: Mean imaging quality was significantly better with computerised tomographic cholangiography compared with magnetic resonance cholangiography. Primary sclerosing cholangitis was identified in 15 cases with computerised tomographic cholangiography and 10 with magnetic resonance cholangiography (P < 0.05). Sensitivity in diagnosing primary sclerosing cholangitis was 94% with computerised tomographic cholangiography versus 63% with magnetic resonance cholangiography. Intrahepatic location was found in 14 cases, definitely present in 10 cases with computerised tomographic cholangiography and five with magnetic resonance cholangiography. Extrahepatic location was found in 13 cases, definitely present in 11 cases with computerised tomographic cholangiography and four with magnetic resonance cholangiography (P < 0.05). Computerised tomographic cholangiography also offered dynamic information about biliary excretion. CONCLUSIONS: Computerised tomographic cholangiography enables more accurate detection and location of primary sclerosing cholangitis than magnetic resonance cholangiography. Since computerised tomographic cholangiography offers additional information about biliary excretion, it may be proposed as an integrative technique in the diagnosis and follow-up of patients with primary sclerosing cholangitis.

Adult↗
PubMed2003

The course of the posterior inferior cerebellar artery may be related to its level of origin.

The course of the posterior inferior cerebellar artery (PICA) was analyzed with reference to its origin and relationships with the medullary and cerebellar surfaces and the adjacent cranial nerves in 40 brains after the injection with acrylic resins of the vertebrobasilar system. In 42.5% of instances, the PICA originated from the lateral medullary segment of the vertebral artery (VA), in 32.5% from its premedullary segment, in 22.5% from the basilar artery (BA), and in 2.5% it was absent. With reference to the level of origin, three patterns of course for the lateral medullary segment of the PICA can be outlined. (1) When it arises from the lateral medullary segment of the VA, it passes below the hypoglossal nerve, and the lateral medullary segment may form a loop with an anterosuperior convexity towards the pontomedullary sulcus (41%), or it may follow a rectilinear course (41%). It passes at the level of the accessory nerve. The tonsillomedullary (TM) segment shows a caudal loop and the telovelotonsillary (TVT) has a cranial loop. (2) When the PICA arises from the BA, it passes above the hypoglossal nerve. The lateral medullary segment forms a loop with lateral convexity (78%) and passes above or through the glossopharyngeal nerve, frequently showing a recurrent course among the roots of the IX, X, or XI cranial nerve. The TM and the TVT segments do not have loops. (3) When the PICA arises from the premedullary segment of the VA, it passes above, below, or through the rootlets of the hypoglossal nerve. In the lateral medullary segment, it follows a rectilinear course (54%) and passes the plane formed by the IX, X, and XI cranial nerves at an intermediate level with respect to the other two patterns. The TM and the TVT segments show caudal and cranial loops. The different origins and courses of the PICA derive from the selection of different branches of the primitive vertebrobasilar plexus during the development of the cerebellum. The existence of an embryologic correlation between the course of the PICA and its level of origin may be useful in the evaluation of its angiographic anatomy.

Adolescent↗
PubMed2003

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".

Anatomy↗
PubMed2003

Pivotal role of the sub-supracardinal anastomosis in the development and course of the left renal vein.

A retroaortic left renal vein is encountered frequently in the dissecting room and in radiological investigations. A number of recent reports of this variation led us to review the development of the renal veins and the inferior vena cava to understand its etiology. For further insight, we also examined our collection of serial sections of cat embryos. In human embryos of about 15 mm the "renal collar," a venous ring around the aorta, is formed by anastomoses between subcardinal and supracardinal veins. The ventral part of the "renal collar" is formed from the intersubcardinal anastomosis, the dorsal part from the intersupracardinal anastomosis and the lateral parts from the sub-supracardinal anastomoses. The primitive renal veins drain venous blood from the metanephros into the sub-supracardinal anastomoses. A retroaortic left renal vein would form if the dorsal part of the sub-supracardinal anastomosis and the intersupracardinal anastomosis persist whereas the ventral part of the sub-supracardinal anastomosis and the intersubcardinal anastomosis regress.

Animals↗
PubMed2003

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.

Anatomy↗
PubMed2001

Fractal analysis of lumbar vertebral cancellous bone architecture.

Osteoporosis is characterized by bone mineral density (BMD) decreasing and spongy bone rearrangement with consequent loss of elasticity and increased bone fragility. Quantitative computed tomography (QCT) quantifies bone mineral content but does not describe spongy architecture. Analysis of trabecular pattern may provide additional information to evaluate osteoporosis. The aim of this study was to determine whether the fractal analysis of the microradiography of lumbar vertebrae provides a reliable assessment of bone texture, which correlates with the BMD. The lumbar segment of the spine was removed from 22 cadavers with no history of back pain and examined with standard x-ray, traditional tomography, and quantitative computed tomography to measure BMD. The fractal dimension, which quantifies the image fractal complexity, was calculated on microradiographs of axial sections of the fourth lumbar vertebra to determine its characteristic spongy network. The relationship between the values of the BMD and those of the fractal dimension was evaluated by linear regression and a statistically significant correlation (R = 0.96) was found. These findings suggest that the application of fractal analysis to radiological analyses can provide valuable information on the trabecular pattern of vertebrae. Thus, fractal dimensions of trabecular bone structure should be considered as a supplement to BMD evaluation in the assessment of osteoporosis.

Adult↗
PubMed2000

Solitary tract nuclei in acute heart failure.

BACKGROUND AND PURPOSE: Symmetrical necrosis of the brain stem nuclei has been described as a consequence of severe transitory cerebral hypoxia mainly in neonates or young adults who experienced an episode of acute ischemia due to transitory acute heart failure. We report selective bilateral lesions of the solitary tract nuclei in 5 adults with short survival intervals after acute heart failure. METHODS: In 5 patients who died due to cardiovascular pathology, histological examination was performed on multiple samples of cerebral hemispheres, on transverse sections of the midbrain and pons, and on transverse serial sections of the medulla stained with hematoxylin-eosin, Klüver-Barrera, and Luxol fast blue. The 3-dimensional reconstruction of the extension and topography of the medullary lesions was obtained with computed image analysis. RESULTS: In 4 subjects who died soon after an episode of acute heart failure (range of survival 10 hours to 2 days), the dorsal portion of the solitary tract nuclei showed an eosinophilic roundish aspect bilaterally. In their context, the neurons showed changes characteristic of ischemic coagulation necrosis. In a fifth patient, a 32-year-old man who died 15 days after an episode of cardiac arrest, 2 circumscribed symmetrical infarcts with macrophagic and astrocytic reactions were found at the same level. The topography of the lesions and the inflammatory reaction and gliosis of patient 5 suggest that the findings in the other 4 patients correspond to initial features of selective lesions of the solitary tract nuclei after acute heart failure: the short interval of survival prevented the evolution of the reactive process. The nucleus is localized at the watershed zone between the terminal branches of the medullary collateral vessels of the vertebral arteries, thus representing the last meadow in the case of sudden fall of the systemic blood flow due to acute heart failure. The absence of lesions of other medullary and pontine nuclei accounts for a selective vulnerability of the neurons of the solitary tract nuclei, and the selective dendritic lesions suggest an excitotoxic component to ischemic cell death. CONCLUSIONS: The commonly accepted resistance of the medullary centers to ischemic hypoxia in adults apparently could be due to the rapidity of death, which prevents the evolution of lesions that can be diagnosed. In addition, minor lesions in the medullary tegmentum after acute heart failure could play a role in the prevention of the resumption of autonomous cardiac and respiratory functions despite life-saving procedures.

Adult↗
PubMed1999

The inhibitor of phospholipase-A2, AACOCF3, stimulates steroid secretion by dispersed human and rat adrenocortical cells.

AACOF3 is a trifluomethylketone analog of arachidonic acid, which inhibits phospholipase-A2 (PLA2). AACOCF3 was found to concentration-dependently increase basal aldosterone and corticosterone secretion by dispersed rat zona glomerulosa and zona fasciculata/reticularis cells, respectively, as well as aldosterone and cortisol production by dispersed human adrenocortical cells. Maximal effective concentration was 10(-5) M, and elicited about 2.5-3.0-fold rises in steroid output. 10(-5) M AACOCF3 also enhanced submaximally (10(-15)/10(-12) M), but not maximally (10(-9) M) ACTH-stimulated hormonal secretion. Quantitative HPLC showed that 10(-5) M AACOCF3 evokes similar increases (from 2.0- to 3.0-fold) in the basal release of the entire spectrum of adrenocortical steroids (i.e. both intermediate and definitive products of steroid synthesis), thereby suggesting that AACOCF3 acts on the early steps of steroid synthesis. Accordingly, when pregnenolone metabolism is prevented by cyanoketone, 10(-5) M AACOCF3 increased by about 8-10-fold the production of this steroid. In conclusion, we have demonstrated a side-effect of AACOCF3, which may become relevant in studies where this chemical is used to inhibit PLA2 in tissues able to convert cholesterol to pregnenolone.

Adrenal Cortex↗
PubMed1999

Abnormal patterns of mucin secretion in ileal neobladder mucosa: evidence of preneoplastic lesion?

In gastric and colonic mucosa the abnormal pattern of mucin secretion has been related to an increased risk of malignant changes. The short- and long-term histologic and histochemical changes in the mucin content of the ileal mucosa have been studied in 180 biopsies from 90 male patients 6-96 months after radical cystectomy and urinary diversion via an orthotopic neobladder. Up to 3 years after surgery, histologic changes comprise a shortening of the villi and an increase in the number of goblet cells. Concomitantly, an abnormal pattern of mucin secretion, with a predominant secretion of sulfomucins, is demonstrable. After 3 years of follow-up, the mucosa progressively flattens and mucin production reduces; after 6 years, the prevalent finding is a flat, avillous epithelium without evidence of mucin secretion. There was no dysplasia or malignancies in any of the patients. The changes in the pattern of mucin production are not potential preneoplastic lesions, but represent a transient defence mechanism of the ileal mucosa exposed to urine.

Aged↗
PubMed1999

Cerebellin enhances in vitro secretory activity of human adrenal gland.

Cerebellin is a 16-amino acid peptide, originally isolated from rat cerebellum, whose presence has been recently demonstrated in the human adrenal glands and especially in medullary chromaffin cells. Cerebellin concentration dependently increased basal catecholamine (norepinephrine and epinephrine) release by human adrenal slices, containing medullary chromaffin tissue, minimal and maximal effective concentrations being 10(-9) and 10(-7) mol/L. Cerebellin (10(-7) mol/L) markedly enhanced cAMP release by adrenal slices, and the protein kinase A inhibitor H-89 (10(-5) mol/L) blocked catecholamine response to cerebellin. Cerebellin did not affect basal steroid secretion of dispersed human adrenocortical cells, but it concentration dependently increased aldosterone and cortisol production by adrenal slices. Again minimal and maximal effective concentrations were 10(-9) and 10(-7) mol/L. Aldosterone and cortisol responses to 10(-7) mol/L cerebellin was suppressed by both the beta-adrenoceptor antagonist l-alprenolol (10(-6) mol/L) and H-89 (10(-5) mol/L). Collectively, the present findings allow us to conclude that 1) cerebellin exerts a sizable secretagogue action on both cortex and medulla of human adrenals; 2) the peptide directly stimulates catecholamine release via the adenylate cyclase/protein kinase A-dependent signaling pathway; and 3) the mechanism underlying the adrenocortical stimulatory effect of cerebellin is indirect and probably involves the release of catecholamines, which in turn, acting in a paracrine manner, enhance steroid-hormone secretion.

Adrenal Cortex↗
PubMed1998

Morphometric analysis of the fibroadipose tissue of the female pelvis.

PURPOSE: The structure of the retroperitoneal connective tissue of the female pelvis was evaluated to determine whether its spatial arrangement may have a role in supporting the pelvic viscera. MATERIALS AND METHODS: After in situ formalin fixation the pelvic viscera with the surrounding connective tissue were removed together with the pelvic floor from 18 female cadavers 48 to 68 years old. Serial macrosections of the bladder base, cervix, lower rectum and pelvic floor complex, cut in coronal (4 cases) and horizontal (10 cases) planes, were stained with azan-Mallory, and the remaining 4 were cut in the horizontal plane and plastinated using von Hagens E12 technique. Morphometry of the retroperitoneal connective tissue was performed using a computerized system for image analysis connected through a black and white television camera to an optic microscope. The diameters of the adipose lobules and density of the connective tissue were evaluated in the proximity of the visceral adventitia and the parietal pelvic fascia, respectively. RESULTS: The retroperitoneal connective tissue of the female pelvis consists of varying amounts of adipose tissue divided into small lobules by thin connective laminae. These laminae are connected to the visceral and parietal layers of the pelvic fascia, and are closely connected to the vascular and nervous bundle sheaths crossing the pelvis. At the level of the sacrouterine and cardinal ligaments we were unable to find any connective ligamentous structure. Only an areolar tissue was seen, which after removal of the lipids demonstrated a fibrillar structure. The mean area of the adipose lobules was smaller (average of 1.41 mm.2) near the viscera with respect to the lateral retroperitoneal connective tissue (average of 1.73 mm.2) due to greater ramification of the connective laminae. CONCLUSIONS: In the absence of real connective ligaments the retroperitoneal connective tissue forms a 3-dimensional network of thin connective laminae that are connected to the visceral adventitia, parietal layer of the pelvic fascia and neurovascular bundles crossing the pelvis. These connective laminae are bounding adipose lobules of different size (smaller near the viscera, larger at the periphery). Overall, the retroperitoneal connective tissue constitutes an anatomical structure that, beyond the functional limits of any individual ligament, may have supporting properties.

Aged↗
PubMed1998

Endothelin-1, acting via the A receptor subtype, stimulates thymocyte proliferation in the rat.

Endothelins (ETs) are a family of vasoactive peptides widely distributed in the body systems, where they carry out major autocrine/paracrine regulatory functions, acting through two main subtypes of receptors (ETA and ETB). Evidence suggests that ETs play a permissive role in the development of neural crest-derived craniofacial structures, among which the thymus. Therefore, we have investigated whether ETs regulate thymocyte proliferation in the adult rat ET-1 (which binds both ETA and ETB receptors) increased the mitotic index (% of metaphase-arrested cells) in the thymus cortex, while ET-3 (which preferentially binds ETB) and the selective ETB-receptor agonists BQ-3020 and IRL-1620 did not. The ETA-receptor antagonists BQ-123 and BQ-610, but not the ETB-receptor antagonist BQ-788, abolished the ET-1 effect. Moreover, BQ-123 and BQ-610, when administered alone, evoked a significant decrease in the mitotic index. Collectively, these findings clearly indicate that endogenous ETs, through the activation of ETA receptors, are involved in the maintenance and stimulation thymocyte proliferation in the adult rat, thereby playing a possible important role in the modulation of the immune-system functions.

Animals↗
PubMed1998

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.

Follow-Up Studies↗