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C Cortesini

Publications and source records attributed to C Cortesini.

At least 37 records · Page 2Linked to original sources
PubMed1993

Morphological evidence for a cecocolonic junction in man and functional implications.

The region above, below and in front of the ileocecal valve opening has been studied in man using both light and electron microscopy. A cecocolonic junction, comprising the colonic basal portion of the ileocecal valve, could be demonstrated in man, due to the specific anatomy of the inner portion of the circular muscle. This muscle was arranged in anastomosing cords, richly innervated and enveloped by elastic fibers. Its smooth muscle cells were characterized by extremely wide sarcoplasmic cisternae and cell-to-cell junctions, numerous caveolae and large amounts of glycogen. Interstitial cells were rarely found. This junction might be considered responsible for (1) ileal flow accommodation, (2) colonic active movements and (3) ileocecal valve closing and opening.

Aged↗
PubMed1992

GABAB receptor-mediated mechanisms in human intestine in vitro.

The spontaneous motility of longitudinal muscle of human jejunum was recorded and the effect of gamma-aminobutyric acid-ergic (GABAergic) drugs was tested. GABA and (-)-baclofen (10(-6)-10(-4) M) dose dependently reduced the amplitude and frequency of the spontaneous contractions; muscimol and 3-aminopropanesulfonic acid (3 x 10(-5) M) were ineffective. The effect of 3 x 10(-5) M GABA was reduced by 3 x 10(-3) M 5-aminovaleric acid but not by 3 x 10(-5) M picrotoxin. The dose-response curve for GABA was shifted to the right by 3 x 10(-3) M 3-aminopropanesulfonic acid. Tetrodotoxin 3 x 10(-7) M prevented the GABAergic action, whereas various receptor antagonists tested did not affect it. GABAergic drugs did not influence the spontaneous motility of either circular or longitudinal muscles of human colon. It is suggested that GABAB receptor activation induces the inhibition of human jejunum longitudinal muscle motility by a neurogenic mechanism. The possible involvement of postganglionic cholinergic neurons is to be evaluated by other techniques.

Colon↗
PubMed1992

Helicobacter pylori and luminal gastric pH. Relationships in nonulcer dyspepsia.

The relationships between gastric pH and Helicobacter pylori infection were studied in 37 consecutive subjects affected with nonulcer dyspepsia. Each underwent esophagogastroduodenoscopy with multiple gastric biopsies for both H. pylori and histologic assessment, and 24-hr antral pH monitoring. H. pylori was harbored by 59.5% of the subjects with whole gastric spread of infection in all but one patient. Histologic gastritis was shown in 70.3% of the subjects. H. pylori was strongly associated with gastritis, both antral nonatrophic and multifocal atrophic. The ranges of 24-hr pH values were 1.3-6.9 in the H. pylori-positive and 1.2-6.8 in the H. pylori-negative group. Differences in pH values between the two groups were not significant. Moreover, the mean percent time duration of pH above 2, 4, and 6 did not significantly differ between the two groups. Therefore, this study has shown that chronic H. pylori infection is not related to luminal gastric pH.

Adult↗
PubMed1991

Usefulness of colonic motility study in identifying patients at risk for complicated diverticular disease.

Colonic motility study was performed on a total of 145 patients. Of these, 55 were patients with symptomatic complicated diverticular disease, 30 had symptomatic uncomplicated diverticular disease, 30 had asymptomatic diverticular disease, and 30 were controls. The pressure sensors were positioned in the descending and the true sigmoid colon. Colonic motility index was significantly higher in symptomatic rather than in asymptomatic diverticular disease in the resting (P less than 0.001) and postprandial (P less than 0.001) states. This confirmed the association between symptomatic diverticular disease and high intraluminal pressure. The patients of the subgroup--complicated diverticular disease--were relatively young (mean age: 51.1 +/- 2.02 years) and had a short history of abdominal pain (18-36 months) and a short segment of colon with diverticula (cm 7.25 +/- 1.31). Our observations suggest that patients showing these indicators are at risk for major complication.

Diverticulum, Colon↗
PubMed1991

Gastric cell proliferation kinetics and bile reflux after partial gastrectomy.

Thirty-four randomized, partially gastrectomized subjects (12 with a Billroth II, 11 with a Billroth I, and 11 with a total biliary diversion reconstruction) were studied in order to assess the relationships between bile reflux, gastric histology, and cell proliferation kinetics. Bile acid quantity and concentration in the gastric aspirates progressively decreased from Billroth II to Billroth I to total biliary diversion (after which reflux was almost absent). Perianastomotic mucosa in Billroth II subjects showed the greatest degree of foveolar hyperplasia, and this decreased markedly with increasing distance from the anastomosis. Hyperplastic changes were less evident in Billroth I, and virtually absent in total biliary diversion subjects. The overall foveolar hyperplasia-like behavior of cell kinetic parameters (total pit cell number, labeled pit cell number, and labeling index) was shown. Moreover, subjects with mean bile acid concentration greater than 150 mumol/L had both a greater prevalence of foveolar hyperplasia and greater values of cell kinetic parameters than those with mean bile acid concentration less than or equal to 150 mumol/L. A superficialization of the proliferative compartment was also evident in the former group. These results show a close relationship between postgastrectomy bile reflux, foveolar hyperplasia, and cell kinetic parameters. Histologic and cell kinetic findings are probably the expression of gastric adaptation to chronic bile reflux exposure. Moreover, the type and entity of cell kinetic involvement and its relationship to foveolar hyperplasia and reflux may suggest new "tools" in post-gastrectomy surveillance and help to clarify patterns of gastric carcinogenesis.

Bile Reflux↗
PubMed1990

Neuromuscular structures specific to the submucosal border of the human colonic circular muscle layer.

The circular muscle layer of the human caecum and ascending colon is clearly subdivided into two portions: an outer one which includes the bulk of the circular muscle layer, and an inner one made up of only six to eight rows of cells. In the right transverse colon no demarcation can be observed, but a difference exists between the innermost and the outermost cells, since those of the two innermost rows possess some peculiarities with regard to the sarcoplasmic reticulum, glycogen particles, caveolae, and intercellular junctions. In the left part of the colon, the circular muscle layer is also divided into two portions. In fact, the innermost smooth muscle cells still possess peculiar morphologies, progressively increase in number, and become separate from each other making up a superficial muscle network. A fibrous lamella, along and inside which a ganglionated nerve plexus runs, is strictly apposed to the submucosal border of the circular muscle layer of the entire colonic length. A second nerve plexus runs between the two portions of the circular muscle layer. Both these plexuses are accompanied by interstitial cells of Cajal in the right colon only. The peculiar organization of the entire submucosal border of the human colonic circular muscle layer distinguishes it from other parts of the gut and probably represents a structural basis for control of human colonic motility. The presence of putative pacemaker cells (interstitial cells and peculiar smooth muscle cells) indicates that the inner border of human colonic circular muscle layer possesses pacemaking activities. Moreover, the interstitial cell--smooth muscle cell ratio differs depending on the colonic level; two main regions can be identified: the right and the left colon. Consequently, we might expect regional variation in pacemaking.

Cecum↗
PubMed1990

Smooth muscle cells, interstitial cells of Cajal and myenteric plexus interrelationships in the human colon.

The plane between longitudinal and circular muscle of human colon, as revealed on examination with light and electron microscopes, has no clear-cut border. Some groups of smooth muscle cells, obliquely oriented and with features similar to both circular and longitudinal ones--the connecting muscle bundles--run from one muscle layer to another. Other groups of smooth muscle cells, possessing their own specific ultrastructural features--the myenteric muscle sheaths--, make up envelopes of variable thickness around some myenteric ganglia and nerve strands, partially or completely embedding them in one or other muscle layer. Non-neuronal, non-muscular cells (interstitial cells of Cajal, covering cells, fibroblast-like and macrophage-like cells) complicate the texture of the myenteric muscle sheaths, creating an intricate, interconnected cellular network inside them, widespread among nerve bundles and smooth muscle cells; however, only interstitial cells have cell-to-cell junctions also with the smooth muscle cells and nerve endings. These data document the existence in this colonic area of two different types of muscle cell arrangements, one of which, the myenteric muscle sheath, only contains putative pacemaker cells.

Aged↗
PubMed1990

The zona glomerulosa of the adrenal gland in rats with portacaval shunt. An ultrastructural and morphometric study.

The zona glomerulosa of the adrenal glands was studied histologically, ultrastructurally and morphometrically in portacaval shunt (PCS)-bearing rats 4 weeks after surgery. Compared with controls, the zona glomerulosa of rats with PCS showed an increase in thickness and a reduction in the number of lipid droplets in the cells of its inner portion, adjacent to the intermediate zone. Moreover, electron microscopy and morphometry of the cells of the inner portion revealed that qualitative and quantitative changes occur, consisting in a decrease in lipid droplets, an increase in the amounts of smooth endoplasmic reticulum and mitochondria, enlargement of the Golgi apparatus, and the appearance of numerous dense bodies at the vascular cell poles. All the above findings indicate that PCS induces an enhanced activity of the fully differentiated cells of the zona glomerulosa, which may be considered as an adaptive response--mediated by an activation of the renin-angiotensin system--to the lowering of the systemic pressure taking place in this experimental condition.

Animals↗
PubMed1989

[Esophageal motor abnormalities, gastroesophageal reflux and duodenogastric reflux in patients with Raynaud's disease].

Twenty-four patients with Raynaud's phenomenon, without ARA criteria for classification, were examined, after clinical history, by means of esophageal manometry, combined gastric and esophageal pH-monitoring, endoscopy. The results showed in these patients a high incidence of esophageal motor abnormalities (66.6%), of gastroesophageal reflux (50%), and of duodenogastric reflux (45.8%).

Cohort Studies↗
PubMed1989

Motility effects of anterior resection of the rectum performed for diverticular disease.

Colonic motility study was performed in fiftyfive patients with symptomatic complicated diverticular disease, who underwent semielective surgery, and in twenty healthy volunteers. The pressure sensors were positioned in the descending and the true sigmoid colon. The colonic motility index was significantly higher in patients with symptomatic complicated diverticular disease than in controls in the basal (p less than 0.001) and post-prandial periods (p less than 0.001). Three months after anterior resection of the rectum with wide resection of descending colon the motility index was significantly reduced (p less than 0.001) in comparison to that before treatment; all patients were asymptomatic. Three years and five years later, the manometric findings continued to be stable and the patients continued to be asymptomatic. These data suggest that anterior resection of the rectum (with wide resection of the descending colon) lowers intraluminal pressure significantly and this effect appears long lasting.

Colon↗
PubMed1989

An ultrastructural study of the smooth muscle cells and nerve endings of the human stomach.

The circular muscle layer of the human stomach was studied with the electron microscope. The smooth muscle cells differ structurally according to their location. In fact, the circular muscle layer of the fundus is made up of large, irregularly shaped smooth muscle cells, with long, thick, dense bands, and immersed in an abundant, elastic supporting connective tissue. In the circular muscle layer of the corpus (the two curvatures and the corpus between), those located in the outermost zone are identical to that commonly described in the alimentary tract, but are gradually substituted, first by larger irregularly shaped cells, and then, towards the innermost area, by flattened cells richer in sarcoplasmic reticulum, with thick and continuous dense bands on their submucosal surface. The smooth muscle cells of the antrum are all identical to the outermost located corporal ones. The gap junctions are absent in the fundus and in the innermost area of the corporal circular muscle layer, are present in the other areas, particularly frequent in the antrum and in the outermost area of the greater curvature. The number of the nerve endings is similar in the fundus, greater curvature and antrum, while it is two-three times more in the other parts of the corpus. They are located at the periphery of the muscle bundles in the fundus, antrum and greater curvature, sparsely scattered among the smooth muscle cells in the other areas of the corpus and contain small agranular and large granular synaptic vesicles, often mixed in the same axon. These nerve endings lie distant from the smooth muscle cells in the fundus, antrum and greater curvature and directly contact the smooth muscle cells in the other parts of the corpus.

Adult↗
PubMed1989

An ultrastructural study of the interstitial cells of Cajal of the human stomach.

The interstitial cells of Cajal of the human stomach were studied at the electron microscope. These cells have an exceptionally elongated shape and several lateral branches. Their cytoplasm characteristically possesses cisternae of smooth endoplasmic reticulum and filaments. A capsular-like structure surrounds them and joins them to each other and to the neighbouring nerve endings and smooth muscle cells, and so they all make up anatomical units. Elastic fibres also make bridges between these cells and between smooth muscle cells and nerve endings. Despite these common characteristics, differences in cell number, distribution in respect of the muscle bundles and some cytoplasmic features have been found, depending on where these cells are located. In fact, there are few interstitial cells in the fundus, poor in filaments and branches, and only located inside the circular muscle layer. In the corpus and antrum they are many, rich in filaments and with their numerous branches make interconnected networks, one inside the circular muscle layer, another apposed to its myenteric surface and, in the antrum, a third one apposed to its submucosal surface, which accompany analogous nerve networks. Substantial differences in the contacts between the interstitial cells and the smooth muscle cells and nerve endings have not been found. For their ultrastructural characteristics a smooth muscle nature has been suggested for these cells. A correlation has also been attempted between the electrical and mechanical activities performed by the different gastric areas and the interstitial cell structure and arrangement.

Adult↗
PubMed1988

Short-term effects of bile diversion on postgastrectomy gastric histology.

Twelve partially gastrectomized subjects who have consecutively undergone total biliary diversion for severe bilious vomiting were studied before and after operation in order to assess the effects of surgery on gastric histology and enterogastric reflux. Before and six months after operation, the following protocol was performed: (1) blood examinations including serum basal gastrin; (2) endoscopy with multiple gastric biopsies; and (3) quantitation of bile acids in the gastric aspirate. Of the preoperative symptoms, bilious vomiting and heartburn completely disappeared postoperatively in all the subjects. Fasting bile reflux was significantly reduced (bile reflux was annulled in six and considerably lowered in the remaining six subjects), and erythema of the gastric mucosa completely disappeared in all the subjects after diversion. Among histological findings, while a significant regression of foveolar hyperplasia was found both in the perianastomotic area and in the body of gastric remnant, none of the other aspects identifiable in postgastrectomy gastric mucosa (chronic gastritis changes included) were affected by diversion. These results show that biliary diversion is effective in correcting reflux, bilious vomiting, erythema, and foveolar hyperplasia of the gastric mucosa and confirm the suggested relationship between bile reflux and gastric foveolar hyperplasia.

Adult↗