Biomedical subjects

P De Paolis

Publications and source records attributed to P De Paolis.

At least 19 recordsLinked to original sources

PubMed2006

Emergency catheter probe endoscopic sonography (CP-EUS): an effective procedure in the assessment of a bleeding gangliocytic paraganglioma.

Catheter probe endoscopic sonography is a relatively rapid and safe procedure, carried out during standard endoscopy, capable of distinguishing solid from cystic lesions and vascular from avascular masses. Herein we discuss the role of catheter probe endoscopic sonography in the emergency assessment of a patient with recent and severe bleeding from an ulcerated polyp, arising from the papilla. During the endoscopy, catheter probe endoscopic sonography showed the solid and submucosal nature of the lesion, suggesting its localised and benign nature and, most importantly, demonstrating the high risk of rebleeding from vascular structures communicating with the ulcer. Because of this finding three metallic endoclips were positioned. The lesion was not removed endoscopically because of its difficult position and the high risk of haemorrhage. The mass, removed through a duodenotomy, was shown to be a gangliocytic paraganglioma, an uncommon tumour, frequently resulting in surgery because of abdominal pain and gastrointestinal bleeding.

Adult↗

PubMed2002

Surgery for carcinoma of the gallbladder. Our experience.

BACKGROUND: Carcinoma of the gallbladder is a gastrointestinal malignancy with a very poor prognosis. The 5-year survival rate amounts to less than 5% in most series. In this study we reviewed the results of surgical treatment for gallbladder carcinoma with special reference to extended radical procedures. METHODS: Between 1995 and 2000 we enrolled 36 patients (17 males and 19 females), 24 of whom were treated with simple cholecystectomy and 12 with radical resection (partial hepatectomy, regional lymphadenectomy, and common bile duct resection). The tumours were classified by stage using the criteria of the American Joint Committee on Cancer (AJCC). Stages, operative procedures, results of pathologic examinations and the outcome of the resected cases were reviewed. RESULTS: There were 2 postoperative deaths (0.55%). The mean follow-up period was 19.1 months (range 1-60). For stage I and II disease extended cholecystectomy had a better result than simple cholecystectomy: the 5-year survival rates were 38.4 versus 19%, respectively. For the patients with advanced stage III or IV gallbladder carcinoma, a significant advantage of survival resulted in case of liver resection as compared to surgical treatment without liver resection: the 5-year survival rates were 20 and 0%, respectively. CONCLUSIONS: The survival of stage I-II patients was good. For the patients in higher stages the prognosis was significantly worse. In these cases more aggressive surgery may be needed.

Aged↗

PubMed2001

Laparoscopic cholecystectomy in cirrhotic patients.

BACKGROUND/AIMS: Laparoscopic cholecystectomy has become the procedure of choice for symptomatic cholelithiasis. A study to evaluate the benefits and risks of laparoscopic cholecystectomy in cirrhotic patients was performed. METHODS: Between January 1994 and December 2000, 1,100 laparoscopic cholecystectomies for symptomatic gallbladder diseases were performed. There were 24 cirrhotic patients (group A) and 72 age- and sex-matched controls (group B). All patients had well-compensated cirrhosis (Child's class A or B). RESULTS: There was no operative mortality in either group and the postoperative complication rates were 20.8 and 9.72% in groups A and B, respectively (p < 0.000001). Operative time in group A was 89.16 vs. 68.41 min in group B (p < 0.000001). The estimated intraoperative blood loss in group A was 106.25 vs. 37.08 ml in group B (p < 0.000001). The average transfusion requirement was 0.155 and 0.0 units in groups A and B, respectively (p < 0.025). The hospital stay in groups A and B was 4.7 and 3.61 days, respectively (p < 0.0500). CONCLUSION: Laparoscopic cholecystectomy in patients with compensated cirrhosis is safe and should be the treatment of choice for these patients. Laparotomy should be applied only if the surgeon considers the operation inadequate to be continued laparoscopically.

Adult↗

PubMed2001

[Sufentanil vs morphine combined with ropivacaine for thoracic epidural analgesia in major abdominal surgery].

BACKGROUND: Pain, postoperative ileus, nausea, vomiting are the universal complications after major abdominal surgery. The aim of this study was to assess pain relief, side effects and recovery of gastrointestinal function during epidural analgesia with ropivacaine plus sufentanil and ropivacaine plus morphine after major abdominal surgery. METHODS: In this prospective study, sixty patients (median age 62+/-12 years) undergoing major abdominal surgery, after informed consent, were randomized into two groups, during a period of 3 months. Patients who were not considered suitable candidates for epidural anaesthesia were excluded. Epidural catheters were inserted at T8-T9 (upper abdominal surgery) or T9-T11 (lower abdominal surgery) and ropivacaine 0,5% 7-9 ml (upper abdominal surgery) or 10-12 ml (lower abdominal surgery) combined with sufentanil 30 mcg (group S, n=30) or with morphine 2 mg (group M, n=30) was injected. General anaesthesia was induced and a continuous epidural infusion of ropivacaine 0.5% 5-10 ml/h was begun. Postoperatively, continuous epidural administration of ropivacaine 0.2% plus sufentanil 0.5 mcg/ml (group S) or ropivacaine 0.2 plus morphine 0.02 mg/ml (group M) was continued. Data on the quality of analgesia, recovery of gastrointestinal function and all side effects were recorded for 48 hours. RESULTS: Incident and resting pain scores were not significantly different among group; although sufentanil provided better resting pain scores at 16th, 20th, 24th hours, and incident pain score at 24th hour. The incidence of nausea, vomiting and pruritus was more in morphine group (p<0,0001). Time to the first flatus was significantly shorter for patients in the sufentanil group (p<0,0001). The quality of pain relief assessed by the patients was rated as good in all patients. CONCLUSIONS: Continuous administration of epidural ropivacaine combined with sufentanil or with morphine resulted in good analgesia. Epidural analgesia with ropivacaine plus sufentanil provided the best balance of analgesia, side effects and recovery of gastrointestinal function.

Abdomen↗

PubMed2000

Characterization of caveolae from rat heart: localization of postreceptor signal transduction molecules and their rearrangement after norepinephrine stimulation.

Caveolae are plasma membrane subcompartments that have been implicated in signal transduction. In many cellular systems, caveolae are rich in signal transduction molecules such as G proteins and receptor-associated tyrosine kinases. An important structural component of the caveolae is caveolin. Recent evidence show that among the caveolin gene family, caveolin-3 is expressed in skeletal and cardiac muscle and caveolae are present in cardiac myocyte cells. Both the ANP receptor as well as the muscarinic receptor have been localized to the caveolae of cardiac myocytes in culture. These findings prompted us to conduct a further analysis of cardiac caveolae. In order to improve our understanding of the mechanisms of signal transduction regulation in cardiac myocytes, we isolated cardiac caveolae by discontinuous sucrose density gradient centrifugation from rat ventricles and rat neonatal cardiocytes. Our analysis of caveolar content demonstrates that heterotrimeric G proteins, p21ras and receptor-associated tyrosine kinases are concentrated within these structures. We also show that adrenergic stimulation induces an increase in the amount of diverse alpha- and beta-subunits of G proteins, as well as p21ras, in both in vivo and in vitro experimental settings. Our data show that cardiac caveolae are an important site of signal transduction regulation. This finding suggests a potential role for these structures in physiological and pathological states.

Adrenergic alpha-Agonists↗

PubMed2000

Role of angiotensin II AT1 and AT2 subtype receptors in the regulation of atrial natriuretic peptide expression in salt-restricted rats.

Previous studies have suggested that angiotensin II modulates ANP secretion and this action appears to be largely independent from its hemodynamic effects. In order to explore the contribution of angiotensin II AT1 (AT1r) and AT2 (AT2r) receptor subtypes in the regulation of cardiac ANP, we studied the effects of selective antagonists of these receptors on ANP mRNA levels in the cardiac chambers of salt-restricted rats. Thirty-one Sprague-Dawley rats (12 weeks-old) weighing 250-350 g were studied during a low salt regimen and randomly assigned to the following treatment groups: AT1r-blockade (losartan) (10 mg/kg/day) (n = 18), AT2r-blockade (PD123319) (50 microg/kg/min) (n = 6), Control (salt-restriction) (n = 7). Treatments were maintained for 7 days; subsequently, 12 rats from the AT1r-blockade group were subdivided in to two groups: AT1r/AT2r-blockade (losartan +PD123319) (n = 6) and AT1r-blockade/vehicle (losartan+vehible) (n = 6), and treated for 7 additional days. Systolic blood pressure was significantly reduced by AT1r-blockade (p < 0.001), while it was not affected by AT2r-blockade. Concomitant treatment with both antagonists (AT1r/AT2r-blockade) restored blood pressure values to baseline (p < 0.001 vs. AT1r-blockade, p = n.s. vs Control). Atrial ANP mRNA was reduced by AT1r-blockade (-42%, p < 0.05) and did not change during AT1r-blockade alone. On the contrary, concomitant treatment with both antagonists resulted in a further significant inhibition of ANP expression (-65% and -36% vs Control and AT1r-blockade, respectively, both p < 0.05). ANP expression in ventricles was not affected by any of these treatments. Our results demonstrate that angiotensin II tonically modulates cardiac ANP expression in our experimental model. In particular, angiotensin II receptor subtypes AT1r and AT2r regulate atrial ANP mRNA levels through a synergic action and independently from blood pressure changes.

Angiotensin II↗

PubMed2000

Defective suppression of the aldosterone biosynthesis during stroke permissive diet in the stroke-prone phenotype of the spontaneously hypertensive rat.

Previous studies have shown that short-term high salt intake unmasks blunted plasma aldosterone suppression in stroke-prone spontaneously hypertensive rats (SHRsp). The aim of this study was to evaluate the response of aldosterone biosynthesis and production to a sustained exposure to the stroke-permissive Japanese-style diet (JD) in young stroke-prone and stroke-resistant SHRs. For this purpose, 6-week old male rats from both strains were divided into 2 dietary groups and received regular diet (SHR = 37, SHRsp = 32) or the JD and 1% saline to drink (SHR = 34, SHRsp = 30) for 4 weeks. All measurements were carried out at the end of the dietary periods. After JD, plasma aldosterone levels were significantly decreased in SHR (from 357.8 +/- 57 to 163.3 +/- 31.5 pg/ml, p < 0.05) but markedly increased in SHRsp (from 442 +/- 56.5 to 739 +/- 125.7 pg/ml, p < 0.05). Consistently, the adrenal aldosterone synthase expression was reduced by JD in SHR (p < 0.05), whereas it was even slightly raised by JD in SHRsp so that, at the end of JD, aldosterone synthase mRNA was 5-fold higher in SHRsp than in SHR. Urinary sodium excretion (mEq/24h) achieved lower levels in SHRsp, so that fractional excretion of sodium was 80.2 +/- 9% in SHR and 40.3 +/- 8% in SHRsp (p < 0.05) in balance studies performed at the end of JD. These different responses of mineralocorticoid biosynthesis and urinary sodium excretion to JD were not accounted for by different adaptations of the renin-angiotensin and atrial natriuretic peptide systems, of serum potassium levels, or of adrenal 11beta-hydroxylase expression in the two strains. Systolic blood pressure was comparable in both strains throughout the experiment. These results demonstrate enhanced aldosterone biosynthesis, associated with reduced urinary excretion of sodium in response to JD in SHRsp before the onset of stroke. This abnormality may play a role in the higher susceptibility to stroke of this model.

Aldosterone↗

PubMed2000

Angiotensin II AT2 subtype receptors: an emerging target for cardiovascular therapy.

This article reviews the impressive amount of knowledge accumulated in the last few years on the angiotensin II AT2 subtype receptor. Although still elusive, a large body of experimental evidence strongly suggests that it may play an important role in the adaptive changes of the cardiovascular structures in response to pathological conditions such as myocardial infarction, congestive heart failure or hypertension. The most intriguing aspects of the biology of this receptor, however, appear to be: 1) the regulation of its transcription, which plays an important role in the expression of the protein in adults or in injured tissues; 2) its interaction or "cross-talk" with the predominant angiotensin II receptor, the AT1 subtype, or with the receptors of other growth factors or cytokines; and 3) its connections with the bradykinin/nitric oxide pathways. These aspects may be relevant for the therapeutical use of drugs which antagonize the renin-angiotensin system, such as angiotensin-converting enzyme inhibitors or angiotensin receptor antagonists, as well as for new therapeutic approaches to the treatment of cardiovascular diseases.

Angiotensin II↗

PubMed2000

Hepatocellular carcinoma in a non-cirrhotic liver. Two case reports and literature review.

Hepatocellular carcinoma (HCC) is closely associated with cirrhosis, but it also develops, although much less frequently, in a non-cirrhotic liver. It is suspected that hepatocellular carcinoma has a different etiology when associated and not associated with chronic liver disease. We report two cases of patients with hepatocellular carcinoma that developed in a non-cirrhotic liver. In the first case we describe an incidental liver nodular lesion containing multiple foci of HCC including pseudogland or trabecular formation and areas of sclerosis. The non-cancerous parenchyma of the liver was histologically unremarkable except for mild fatty changes of hepatocytes and minimal dysplasia. The second case describes a combined hepatocellular carcinoma and cholangiocellular carcinoma (CCC) (mixed carcinoma) in a patient who was serologically negative for both hepatitis B and C viruses. The adjacent liver parenchyma showed mild piecemeal necrosis and mild lobular activity compatible with chronic viral hepatitis, but cirrhosis was not established. This case appears to indicate that mixed type carcinoma can develop in a non-cirrhotic liver, with CCC being far more dominant than HCC; such a finding is extremely unusual, based on previously published reports.

Aged↗

PubMed2000

[Intestinal fistulas in Crohn disease].

BACKGROUND: Only a part of patients suffering from Crohn's disease has enteric fistulae and a different behaviour of Crohn's disease with fistulae is reported in the literature. Aim of this paper is to evaluate if enteric fistulae are a factor conditioning mortality, morbidity and overall postoperative course, in patients with Crohn's disease. METHODS: Data on the postoperative course of 126 laparotomies for Crohn's disease, performed between November 1993 and July 1998, have been prospectively examined. Moreover, the presence of enteric fistula has been evaluated during surgery. RESULTS: Out of 126 interventions, in 58 (46%) enteric fistulae were present. Mortality (5.2% vs 0), morbidity (14.5% vs 7.3%), necessity for a temporary ostomy (20.4% vs 3.5%) were greater in those patients with fistula, as compared as those without fistula. CONCLUSIONS: In conclusion, it is suggested that Crohn's disease with fistulae is a different type of disease, with higher mortality and morbidity rates.

Adult↗

PubMed2000

Management strategies in resection for carcinoma of the hepatic duct confluence: how to increase the resectability rate. Our experience and literature review.

The resectability rate of hilar bile duct carcinoma is reported to be variable and to inversely correlate with the size of the associated liver resection. In an attempt to reduce the risk of postoperative liver failure, the induction of a hypertrophy of remnant liver by preoperative portal vein embolization (PVE) has been proposed. We hereby analyse the results and the technical aspects of this procedure along with our personal experience.

Bile Duct Neoplasms↗

PubMed1999

Predominant expression of group-II metabotropic glutamate receptors in the goldfish brain.

Group-II metabotropic glutamate (mGlu) receptors (mGlu2/3 receptors) were highly expressed in various regions (telencephalon, optic tectum, and cerebellum, but not vagal lobe) of the goldfish brain. In the goldfish telencephalon, expression of mGlu2/3 receptors was even higher than in the rat cerebral cortex. In contrast, mGlu5 receptors showed low levels of expression in all goldfish brain regions, whereas mGlu1a receptors were only expressed in the goldfish cerebellum. Pharmacological activation of group-II mGlu receptors with the selective agonists, 2R,4R-4-aminopyrrolidine-2, 4-dicarboxylic acid and (2S,2'R,3'R)-2-(2,3-dicarboxycyclopropyl) glycine, reduced the evoked release of glutamate from goldfish brain synaptosomes, whereas agonists of group-I and -III mGlu receptors (3, 5-dihydroxyphenylglycine and L-2-amino-4-phosphonobutanoate) were inactive. The predominance of group-II over group-I mGlu receptors in the goldfish brain may provide a natural defense against excitotoxic neuronal death and contribute to the unusually high resistance of goldfish against hypoxic brain damage.

Animals↗

PubMed1999

Ketoconazole inhibits lipopolysaccharide-induced activation of the nitric oxide synthase gene in the murine macrophage cell line J774.

The aim of this study was to determine whether ketoconazole can affect the expression of the nitric oxide (NO) synthase gene in the murine macrophage cell line J774. The inducible enzyme (i-NOS) is activated in murine macrophages by LPS and cytokines. Exposure of the J774 cell line to ketoconazole for 24 h did not induce any NO release. Cells preincubated with ketoconazole and treated with LPS showed a significant decrease in nitrite levels in the culture medium, compared with controls (cells treated with LPS alone). The addition of 1 mM N-monomethyl-L-arginine (L-NMMA), a structural analogue of arginine, reduced nitrite levels by about 88+/-9.2% in cells treated with LPS alone, whereas in those treated with ketoconazole + LPS, the levels were comparable to the baseline values detected in control cells. Northern blotting, used to assess i-NOS mRNA expression in the J774 cells, showed that ketoconazole reduced the LPS-induced increase in i-NOS mRNA activation by about 50%. These results support another mechanism for the antiinflammatory effect of ketoconazole (i.e. reduction in i-NOS gene expression and consequently inhibition of reactive radical NO production), that may explain the antierythema and antiedema action of this compound, besides its antimycotic effects.

Animals↗

PubMed1999

Modulation of the AT2 subtype receptor gene activation and expression by the AT1 receptor in endothelial cells.

OBJECTIVE: To investigate whether angiotensin II type 2 (AT2) receptor (AT2-r) promoter activity and expression are modulated by angiotensin II (Ang II), and whether the AT1 receptor (AT1-r) is involved in this effect. DESIGN AND METHODS: Primary endothelial cells obtained from NEONATAL rat aorta, expressing both receptors, were transfected with the rat AT2-r promoter region cloned into a pCAT-reporter vector. The reporter-expression study was performed in a transient transfection assay system. Transfected cells were studied following angiotensin-converting enzyme inhibition to prevent endogenous formation of Ang II. Cells were subsequently stimulated for 6 h with Ang II, either alone or in combination with the AT1-r antagonist DuP753. AT2-r mRNA was assessed by RNase protection assay during the same pharmacological stimuli. RESULTS: Stimulation with Ang II caused an increase in promoter activity (+50%, P < 0.05 versus baseline), whereas mRNA expression was reduced by 50% (P < 0.05 versus baseline). Concomitant treatment with DuP753 and Ang II was associated with a 98% increase in promoter activity (P < 0.05 versus baseline). DuP753 also prevented the reduction in mRNA; it actually produced a 100% increase in AT2-r mRNA accumulation (P < 0.01 versus baseline). Studies with the AT2-r antagonist PD123319 indicate that the AT2-r is also involved in the regulation of AT2-r gene promoter activity. CONCLUSIONS: These data indicate that Ang II increases AT2-r promoter activity and decreases AT2-r mRNA accumulation in endothelial cells. The AT1 subtype receptor is involved in the modulation of both effects of Ang II. These findings suggest that changes in the expression of AT2 receptors may occur during treatment with AT1-r antagonists, and they indicate the existence of a cross-talk between AT1 and AT2 receptors.

Angiotensin II↗

PubMed1999

[Surgical treatment of internal duodenal diverticulum. Report of 2 clinical cases].

Internal duodenal diverticulum is a rare disease. Nowadays, less than 100 cases are reported in Western literature. Even if it is a pathology of malformative origin, the first clinical manifestations occur quite always during the III decade. Main symptom is a violent, suddenly arisen, abdominal colic, often associated with meals and with spontaneous remission. Frequency of accesses is variable in time; in most serious cases, colics are so close to cause a considerable reduction of nutrition. Among diagnostical means, very useful are Rx enema (that offers pathognomonical images) and endoscopy, by which the formation can be visualized directly and its connection with papilla can be delineated. In some rare cases, differential diagnosis has to be made with cystic dilatations of bile duct, and particularly with type III according to Alonso-Lej classification or choledochocele. When such a distinction is not possible, differential diagnosis will be made on the basis of histological examination of the type of mucosa present in the internal aspect of the diverticulum. Therapy of symptomatic forms is surgery. The technique of choice is transduodenal diverticulectomy. Cannulation of bile duct is a useful means to found the papilla during intervention, to protect duodenal suture in the postoperative period and to control it radiologically. Two cases of internal duodenal diverticulum operated on in the last 2 years are described and diagnostical and therapeutical items are discussed.

Adult↗

PubMed1998

Role of the angiotensin II AT2-subtype receptors in the blood pressure-lowering effect of losartan in salt-restricted rats.

OBJECTIVE: The aim of this study was to evaluate the potential role of the angiotensin II (Ang II) AT2 receptors (AT2) in the control of blood pressure (BP) in the rat and the effects of AT2 receptors on BP during AT1 receptor (AT1) antagonism. METHODS: The study was performed in 52 Sprague-Dawley rats, which were preliminarily salt-restricted (SR) to enhance circulating and tissue renin-angiotensin system activity. To explore whether AT2 plays a role in BP regulation, the BP effects of the selective AT2 and AT1 receptor antagonists PD123319 (PD) (50 microg/kg/min) and losartan (Los) (10 mg/kg/day), were studied. Seven rats were used as a control group. To define whether AT2 plays a role in the BP response observed during AT1 antagonism, 17 Los treated rats were divided into two groups: seven were treated with both antagonists (Los + PD) and 10 rats received Los + vehicle. The effects of both drugs were also studied in bilaterally nephrectomized rats (NX). All treatments were maintained for 1 week RESULTS: Los reduced BP significantly in both intact (P < 0.001) and NX (P < 0.05) rats, while PD increased BP in intact and NX rats (both P < 0.001). In the Los + PD group BP levels were significantly higher (P < 0.001 vs Los and Los + vehicle, P = ns vs pretreatment), while vehicle infusion did not modify the BP response to Los. CONCLUSION: The results show that in salt-restricted rats AT2 blockade offsets the BP-lowering effect of losartan and suggest that AT2 receptors contribute to the hypotensive effects of losartan. Thus, AT1 receptor antagonists such as losartan, which are becoming widely used in the clinical treatment of hypertension, may reduce BP not only by blockade of AT1 receptors, but also through the stimulation of AT2 receptors by the excess of angiotensin II.

Angiotensin II↗

PubMed1998

[Lipohyperplasia or intestinal lipomatosis].

Lipohyperplasia or intestinal lipomatosis is an infrequent disease characterised by anomalous infiltration of adipose tissue in the intestinal submucosa. Localised forms are generally asymptomatic, whereas diffuse forms may lead to intestinal subocclusion, digestive hemorrhage or diarrhoea. Although benign, the differential diagnosis of intestinal lipomatosis with malignant pathologies of the colon or appendix often prompts the need for surgical exploration and the histological analysis of biopsy material. Surgical exeresis of the lesion is generally associated with the normalisation of clinical symptoms. The authors report the onset and clinical evolution of two cases of intestinal lipomatosis referred to their attention.

English Abstract↗

PubMed1997

Plasma mevalonate concentrations in uremic patients.

Mevalonic acid (mevalonate or MVA), is an obligate precursor in the biosynthetic pathway of cholesterol. It is partially metabolized by the kidneys and its plasma concentrations are an index of endogenous cholesterol synthesis. The aim of the present study was to evaluate plasma MVA concentrations in uremic patients with different degrees of chronic renal failure (CRF; group A), and the effects of a single hemodialysis treatment on plasma MVA in a group of patients with end-stage renal disease (ESRD; group B). CRF patients exhibited a higher mean basal mevalonate concentration (13.3 +/- 6.5 ng/ml) than control subjects (4.68 +/- 1.32 ng/ml; P < 0.001). A statistically significant direct correlation was evident in CRF patients between mevalonate and creatinine plasma levels (r = 0.86; P < 0.001). A single hemodialysis treatment was associated with a significant reduction of plasma mevalonate concentrations four hours after the hemodialysis session (-57%; P < 0.001) and an increase up to the basal values 24 hours after the end of the treatment. In conclusion, our results demonstrated: (i) higher plasma MVA concentrations in patients with decreased renal function; (ii) a direct relationship between plasma MVA levels and the degree of kidney failure as expressed by creatinine plasma concentrations; and (iii) a clear cut reduction of elevated plasma MVA levels after a single hemodialysis treatment.

Adult↗