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Biomedical subjects

P Spinelli

Publications and source records attributed to P Spinelli.

At least 37 records · Page 2Linked to original sources
PubMed1998

Echinococcus granulosus: an intraperitoneal diffusion chamber model of secondary infection in mice.

The present work describes a new experimental model of secondary infection which allows, through the recovery of the parasite together with its local in vivo environment, examination of the local nonadaptive immune response of the infected host and the differentiation of the parasite from protoscoleces to cysts. In this model we administered protoscoleces within silicone diffusion chambers, previously implanted into the peritoneal cavities of mice. The process of designing the model involved, first, determination of the optimal time postimplantation to infect the mice and, second, evaluation of the parasite's ability to establish infection within the chambers. The optimal time for infection was considered to be after the inflammation caused by implantation of the chambers had subsided. Our results showed that by day 20 postsurgery, three parameters used as indications of inflammation (complement C3, serum amyloid P protein, and polymorphonuclear cells in the peritoneum and in the chamber contents) had reverted to their normal levels. In our study of parasite differentiation, we found that 2-3% of the total number of parasites inoculated into the chambers were recovered as viable cysts after 100 days. Throughout the infection period, the population of parasites recovered was heterogeneous; certain parasite morphologies that have not been described previously were observed. In conclusion, the use of intraperitoneal diffusion chambers offers a potential tool for investigating the in vivo differentiation process of secondary cysts of Echinococcus granulosus in mice and the early local interactions between host and parasite during this process.

Animals↗
PubMed1998

Exposure to cobalt and nickel in the hard-metal production industry.

OBJECTIVE: The shortage of cobalt (Co) on the metal market forced the industry to add nickel (Ni) to Co as a binding agent for the sintering of hard metal. This change enabled us to study (1) the exposure to Ni powder and (2) the effect of Ni on Co uptake (and vice versa). METHODS: Equal amounts of Co and Ni were used in the mixture in a plant employing 50 workers. Both personal ambient-air samples and single-void urine samples were taken twice in the same week, i.e., on Monday and Thursday. Atomic absorption spectroscopy (AAS) was used for analyses. RESULTS: The airborne availability of Ni (mean value 41.65 +/- 6.29 micrograms/m3) was 2-fold that of Co (mean value 21.85 +/- 24.25 micrograms/m3), although the two series of data (n = 20) were significantly correlated. Even if the Co and Ni urinary concentration values (n = 45) recorded on Monday morning and Thursday evening were significantly correlated, at the end of the week there was a 3-fold increase, specifically, from 7.3 to 22.28 micrograms/l, in Co elimination (a significant difference) and a 30% increase in Ni elimination from 11.98 to 15.83 micrograms/l. Moreover, on Monday morning, 90% of Ni urinary concentration values were higher than those of Co as opposed to only 33% on Thursday evening. In the six cases in which both airborne and urine determinations were performed on the 2 days, no significant relationship was found between external exposure and biological monitoring data. CONCLUSIONS: Although Ni uptake was variable, it was generally low, whereas Co uptake was substantial, as had previously been observed in the same plant when Co was the only binder under use. It was therefore possible to rule out any influence of Ni exposure on Co uptake and to suggest the contrary, as has been demonstrated in bacterial species and in rats using everted intestinal sacs.

Adult↗
PubMed1998

Observation of thoracic duct morphology in portal hypertension by endoscopic ultrasound.

BACKGROUND: Thoracic duct dilation has been demonstrated in portal hypertension and hepatic cirrhosis by lymphangiography and laparotomy and at autopsy. It is thought to be secondary to increased hepatic lymph flow and has been described in the absence of ascites or esophageal varices. The aim of the present study was to observe thoracic duct morphology by endoscopic ultrasound in various subsets of patients with portal hypertension and hepatic cirrhosis and also to validate existing radiologic/surgical data. METHODS: The thoracic duct of 33 patients with cirrhosis and portal hypertension was studied by endoscopic ultrasound. Patients were divided into four groups: 1, patients with ascites and esophageal varices; 2, esophageal varices without ascites; 3, without esophageal varices or ascites; 4, extrahepatic portal hypertension due to pancreatic malignancy. The thoracic duct diameter was also measured in 14 control subjects (group 5). RESULTS: When the thoracic duct diameter for the five groups was compared with analysis of variance, significance was p < 0.0001; by pairwise comparison, group 1 differed from the other four groups (p < 0.05). Thoracic duct dilation (5.61 mm) was seen in group 1 patients, whereas no dilation was present in groups 2 through 4. Additionally, thoracic duct diameter in 33 portal hypertensive and/or cirrhotic patients was significantly different from that in the 14 control subjects (p = 0. 003). CONCLUSION: The thoracic duct can be reliably identified by EUS in patients with hepatic cirrhosis and portal hypertension. Dilation of the duct is seen only in patients with hepatic cirrhosis, ascites, and esophageal varices. No thoracic duct dilation is present in extrahepatic portal hypertension. Contrary to existing radiologic/surgical data, thoracic duct dilation is not seen in all patients with hepatic cirrhosis and portal hypertension signifying advanced disease. A dilated thoracic duct by endoscopic ultrasound should be considered yet another sign of portal hypertension.

Ascites↗
PubMed1998

Ranitidine bismuth citrate with either clarithromycin 1 g/day or 1.5 g/day is equally effective in the eradication of H. pylori and healing of duodenal ulcer.

BACKGROUND: No randomized double-blind studies have been performed to compare clarithromycin 1 g/day with higher doses of the macrolide (1.5 g/day) when combined with ranitidine bismuth citrate (RBC). AIM: To compare H. pylori eradication and ulcer healing rates of RBC 400 mg b.d. for 4 weeks combined for the first 2 weeks either with clarithromycin 500 mg b.d. (Group A) or clarithromycin 500 mg t.d.s. (Group B). METHODS: Two hundred and seventy-three patients with H. pylori-positive active duodenal ulcer were included. H. pylori infection was detected by CLO-test and histology on antral and corpus biopsies before and at least 4 weeks after the end of therapy. Eradication was assumed if both CLO-test and histology results were negative for H. pylori. RESULTS: Eradication/healing rates according to intention-to-treat and per protocol analysis were 76/82% and 87/92% for Group A and 78/85% and 88/95% for Group B, respectively (P = N.S.). Adverse events were reported by 7% and 12% of patients in Groups A and B, respectively, and they were generally mild. CONCLUSIONS: RBC in co-prescription with clarithromycin 500 mg b.d. is as effective as RBC plus clarithromycin 500 t.d.s. in eradicating H. pylori and healing duodenal ulcers.

Adolescent↗
PubMed1998

Molecular basis of open-angle glaucoma in Italy.

Glaucoma is a group of ocular diseases characterized by an optic neuropathy in which degeneration of retinal ganglion cells leads to a characteristic excavation of the optic nerve head. Primary open-angle glaucoma (POAG) can be subdivided into two groups according to age of onset:- 1. the more common middle- to late-age onset, chronic open-angle glaucoma (COAG) diagnosed after the age of 40 years; 2. the rarer juvenile open-angle glaucoma (JOAG), which is diagnosed between the age of 3 years and early adulthood. Recently, the gene coding for the trabecular meshwork-induced glucocorticoid response protein (TIGR), located in chromosome 1 (1q23-25), was found mutated in patients affected by POAG. In this work we describe the clinical and molecular genetic features of several Italian families affected by autosomal dominant POAG, collected in various regions of Italy.

Adult↗
PubMed1998

Palliation of tracheobronchial malignant obstruction with metal stents in emergency conditions.

BACKGROUND: Endoluminal obstruction, caused by tracheobronchial malignancies, can require urgent treatment in case of severe respiratory distress. In emergencies, self-expanding metal stents can be endoscopically employed to solve acute symptoms. METHODS: Between April 1992 and August 1996, 7 patients were treated by positioning of metal stents in emergency conditions and observed to verify the immediate efficacy of endoscopic therapy. Tracheal stenosis, stenosis of trachea and right main bronchus and obstruction of trachea and left main bronchus were present in 5, 1 and 1 patient, respectively. Metal stents for intravascular use (Wallstent, Schneider, Zurich, Switzerland) were positioned on a guide wire by fiber- or video-bronchoscope, after local anaesthesia, monitoring the arterial oxygen saturation of every patient. RESULTS: In six patients breathlessness was resolved immediately. The last patient, suffering from severe mediastinal involvement, died from cardiac failure. No complication occurred. Mean survival was 40 days. CONCLUSIONS: Self-expanding metal stent placement is an easy and safe method, does not require general anaesthesia, is less traumatic and well tolerated, is quick to be performed and then can be used in emergencies. Nevertheless, it is impossible to remove the stent in case of malpositioning. Although this group is small, endobronchial stenting using metallic prostheses permits immediate ventilation and palliation of large airway obstruction.

Aged↗
PubMed1997

The comparative effects of subchronic administration of triphenyltin acetate (TPTA) on the hepatic and renal drug-metabolizing enzymes in rabbits and lambs.

The purpose of this study was to determine whether subchronic (70 days) oral exposure to moderate to high levels of triphenyltin acetate (TPTA), an organotin derivative used worldwide, would affect the microsomal hepatic and renal drug-metabolizing enzymes in rabbits and lambs. Rabbits were offered a diet containing 0, 15, 75 or 150 ppm TPTA, while lambs were daily given 0, 1.5 or 7.5 mg TPTA per kg bw. The tin content in the liver and kidneys was measured by atomic absorption spectrophotometry. In the rabbits' livers, TPTA failed to affect the cytochrome P450 content, or the oxidative, hydrolytic (carboxylesterase) or conjugative (UDPG-transferase) enzyme activities studied. In contrast, a striking dose-related increase in both P450 content and carboxylesterase activity (up to 280%) was detected in the rabbits' kidneys, but the ECOD and EROD activities were respectively unchanged or moderately depressed. None of the enzymes studied showed statistically significant changes in the ovine hepatic or renal subfractions. The results suggest that repeated exposure to TPTA could lead to the induction of a particular P450-isoenzyme in rabbit kidneys which is concerned with the metabolism of endogenous compounds (e.g. steroids, prostaglandins, thromboxanes). The lack of significant tissue- and species-related differences in the concentration of tin supports the hypothesis that the changes observed in the rabbits' kidneys may not have been caused solely by the accumulation of the metal in the tissues.

7-Alkoxycoumarin O-Dealkylase↗
PubMed1996

Non-small-cell lung cancer: detection of mediastinal lymph node metastases by endoscopic ultrasound and CT.

In this prospective study endoscopic ultrasound (EUS) and computed tomography (CT) were evaluated to compare diagnostic accuracy of the two methods. They were performed for nodal staging in selected patients admitted to our institution for non-small-cell lung cancer (NSCLC). From February 1992 to July 1993, 45 patients were recruited for the study when N3 and N2 nodal involvement were excluded on standard chest X-ray. All the patients completed EUS and CT exams for staging before treatment. The results of sensitivity, specificity and accuracy were obtained in 30 patients who underwent surgical treatment with macroscopically radical resection of T and N, which allowed a complete surgical and histological comparison of CT and EUS findings. On a per-patient basis CT results were: sensitivity 63.6%, specificity 78.9% and accuracy of 73.3%; on a nodal station basis sensitivity, specificity and accuracy were 70.0%, 85.1% and 81.6%, respectively. The EUS evaluation showed, on a per-patient basis, values of sensitivity 45.5%, specificity 57.9% and overall diagnostic accuracy of 53.3%. On a nodal station basis the results were 50.0%, 86.6% and 78.2%, respectively. The results obtained in the 30 patients when both techniques were taken in association regarding sensitivity (90.9%), specificity (73.7%) and accuracy (80.0%) on a per-patient basis suggest that the association of EUS and CT offers the best approach for preoperative staging of NSCLC.

Adenocarcinoma↗
PubMed1996

Conservative management of esophageal leaks by transluminal endoscopic drainage of the mediastinum or pleural space.

BACKGROUND: The management of postoperative leaks into the mediastinum or pleural cavities after esophageal surgery yields unsatisfactory results. A recently described method, drainage of the mediastinum or pleural cavity through suture line defects, has been used in our department with eight patients. METHODS: A suction tube was advanced over an endoscopically placed guide wire into the abscess from inside the esophagus, and gentle aspiration was used to remove saliva and secretions. Intravenous antibiotics and total parenteral nutrition were also given. RESULTS: The sepsis was rapidly controlled, and the abscess cavity progressively collapsed in all cases. Seven patients recovered and were discharged 34 to 61 days after operation; one died of concomitant complications. CONCLUSIONS: This method seems promising for the management of intrathoracic esophageal leaks.

Aged↗
PubMed1995

Natural fluorescence of normal and neoplastic human colon: a comprehensive "ex vivo" study.

BACKGROUND AND OBJECTIVE: A microspectrofluorometric analysis on "ex vivo" samples from normal tissue and adenocarcinoma of the human colon has been performed to characterize the histological, biochemical, and biophysical bases of the autofluorescence. STUDY DESIGN/MATERIALS AND METHODS: Differences between normal and tumor tissues are found that concern both the intensity distribution and spectral shape of the autofluorescence emission. The different pattern of the fluorescence intensity can be related to the histological organization of the tissue, and involves mainly the arrangement of the submucosa, the most fluorescent layer. RESULTS: The most evident differences in the spectral shape found in the 480-580 nm range involve the stromal compartment, seem to be due to the presence of different fluorochromes, and are possibly related to the host response to the tumor. CONCLUSION: The nature and the extent of the autofluorescence modification between normal and tumor tissue in sections explain at least partly the evidence of the "in vivo" analysis and highlight the importance of excitation for full exploitation of the potentials of autofluorescence in diagnosis.

Adenocarcinoma↗
PubMed1995

Prevention and treatment of complications after endoscopic prostheses placement in tumors of the upper gastrointestinal tract.

Endoscopic intubation is a popular palliative method to resolve immediately malignant dysphagia. However, the complication rate is still high. Between 1978 and 1993, at the Division of Diagnostic and Surgical Endoscopy of Istituto Nazionale Tumori in Milan, 305 patients suffering from malignant dysphagia, were endoscopically treated by insertion of an endoprosthesis. We report the analysis of data regarding our complication rate, compared with the literature, and our experience in preventing managing complications related to this endoscopic procedure.

Adult↗
PubMed1994

Absorption and excretion of cobalt in the hard metal industry.

Absorption and excretion of cobalt in the hard metal industry was investigated by means of ambient air and urine measurements in three factories with high levels of environmental cobalt pollution. In the presence of poor hygiene conditions and permission to smoking during work, there was no relationship between cobalt ambient air and cobalt urine concentrations. Such a finding was therefore attributed to a substantial skin contact. A simple experiment of skin exposure to freshly mixed or waste powder on volunteers identified a ten-fold increase of cobalt in urine in the post-exposure samples, thus confirming the contribution of dermal exposure as a route of entry. An improvement in the hygiene of the working conditions helped to investigate the relationship between exposure and excretion level. Cobalt uptake through the different routes of entry may be substantial, and requires a more prolonged exposure-free period so that the excretion rate can be reduced to the reference population level.

Absorption↗
PubMed1994

Ex vivo optical properties of human colon tissue.

Using a spectrophotometer equipped with an internal integrating sphere, the absorption (mu a) and the reduced scattering (microseconds') coefficients of ex vivo human colon tissues were evaluated from reflectance and transmittance measurements. Mu a and microseconds' varied from 47.7 to 1.0 cm-1 and from 14.2 to 6.2 cm-1, respectively, on passing from 300 nm to 800 nm. These results can be used to estimate the optical penetration depths when photodynamic therapy or light-induced fluorescence procedures are used.

Absorption↗