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Biomedical subjects

S Pozzi

Publications and source records attributed to S Pozzi.

29 records · Page 2Linked to original sources
PubMed1995

Parenteral antibiotics and selective intestinal decontamination do not prevent enteric bacterial overgrowth or translocation observed in a swine model of small bowel transplantation.

Alterations in the luminal microflora and increased intestinal translocation have been reported to occur following experimental and clinical small bowel transplantation (SBT). Selective intestinal decontamination (SID) has been used to prevent luminal overgrowth and bacterial translocation. Despite the wide use of SID in clinical SBT, there are no data supporting its usefulness in this situation. Thus, the aim of this investigation was to examine the effects of cyclosporine A (CsA) and SID upon bacterial overgrowth and translocation in a swine model of SBT. Nineteen Large White female pigs weighing 30 +/- 2 kg underwent a total orthotopic SBT and were randomly allocated to one of the following experimental groups as follows: Group 1 (No. 8) CSA 25 mg/kg body weight (b.w.)/day administered subcutaneously and Cefazolin 2 g/day im. Group 2 (No. 6) received the identical immunosuppression but the Cefazolin 2 g/day im was discontinued on the 5th Postoperative Day (pod) and switched to a SID regimen consisting of Vancomycin, 1 g, Nystatin, 500,000 IU, Colistin, 1,500,000 IU, and Tobramycin, 100 mg, given through a gastrostomy tube. Group 3 (No. 5) received no immunosuppression but antibiotic consisting of Cefazolin 2 g im/day. Group 4 (No. 7) underwent a small bowel autotransplantation. Group 4 received SID as in group 2 but no immunosuppression was given. Finally, 17 normal animals were sham-operated and were used as normal controls (N group). The animals in groups 1, 2, and 4 were sacrificed on the 29th pod. Those in group 3 were sacrificed on the 7th pod.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Luminal bacterial overgrowth and intestinal translocation in pigs given either cyclosporin A or 15-deoxyspergualin after small bowel transplantation.

OBJECTIVE: To examine the effects of two immunosuppressant regimens on composition of the bowel flora and rate of translocation after transplantation of the small bowel in pigs. DESIGN: Randomised controlled study. SETTING: University hospital, Italy. MATERIAL: 35 female Large White pigs. INTERVENTIONS: 9 Animals were not operated on (normal controls). 19 Animals underwent total orthotopic small bowel allotransplantation and were then randomised to receive: group A (n = 8) cyclosporin A 25 mg/kg subcutaneously and cephazolin 2 g intramuscularly daily; group B (n = 6) 15-deoxyspergualin (15-dos) 3 mg/kg for 7 days then 1.5 mg/kg, cephazolin 2 g intramuscularly daily for 4 days then selective intestinal decontamination with colistin 1.5 million U, tobramycin 100 mg, vancomycin 1 g, and nystatin 500,000 U daily; and group C (n = 5) cephazolin 2 g intramuscularly daily for 8 days. A further group (D, n = 7) underwent orthotopic autotransplantation and received the same antibiotic and selective decontamination regimens as group B. Animals in group C were killed on day 8, and the rest on day 29. MAIN OUTCOME MEASURES: Signs of rejection, graft versus host disease, luminal overgrowth, and evidence of translocation to mesenteric lymph nodes. RESULTS: All animals in group C, and 2 in group B, showed signs of acute rejection. There was a significant overgrowth of both aerobic and anaerobic bacteria in all 3 groups after allotransplantation compared with normal controls. Bacterial translocation was similar in autografted and allotransplanted animals. Mesenteric lymph nodes were colonised in 4/9 controls, 7/8 in group A, 4/4 in group B, 5/5 in group C, and 7/7 in group D. CONCLUSION: Neither cyclosporin A nor 15-dos prevented luminal overgrowth or bacterial translocation to mesenteric nodes up to one month after operation. The rate of translocation was similar in autotransplantation and allotransplantation, suggesting that non-immunological factors (for example, denervation and interruption of lymphatics) may have a role in these alterations.

Animals↗
PubMed1994

[Artificial nutrition in the management of lesions caused by caustic ingestion].

Ingestion of a large amount of corrosive agent results in a life-threatening condition which requires a much more aggressive diagnostic and therapeutic approach than was formerly recommended. Based on experience with a wide spectrum of upper g-i injuries in 56 patients treated through a 5-year-period, the Authors suggest an early staging of the lesions by immediate endoscopy, followed by adequate resective surgery for high-degree esophago-gastric lesions. Indications, techniques of artificial nutrition and the nutritional requirements of this condition are presented and fully discussed. The prompt institution of total parenteral nutrition is an essential part of the emergency management of these lesions. Fourteen patients underwent surgical treatment for the lesions; in all cases a Witzel's feeding jejunostomy was performed and postoperative enteral nutrition was started. Eight patients underwent a reconstructive operation of colon interposition and received home-based total enteral nutrition for a period of 8-25 weeks. No major complications relate to nutritional support occurred and nutritional indexes were normal at the end of the treatment.

Adolescent↗
PubMedDate not supplied

QSAR approach to POPs screening for atmospheric persistence.

The environmental behaviour of a persistent organic pollutant (POP) is mainly controlled by its persistence, its tendency to undergo long-range transport (LRT) and its physicochemical properties. Atmospheric half-life is one of the criteria commonly used to study air persistence and LRT potential. For the 12 UNEP POPs and another 48 possible POPs, the mean and maximum half-life estimations for degradation in air are modelled using different molecular structure descriptors (atom and fragment counts, topological and WHIM descriptors), selected by Genetic Algorithm, in QSAR regression models. Both values are modelled to obtain an average estimate and a precautionary value for ranking and screening purposes. The models, validated for their predictivity, could be applied to predict unavailable data. Principal component analysis (PCA) was then used to explore the half-life data in addition to the physicochemical properties that are most relevant to atmospheric mobility; the aim has been to screen and rank POPs with regard to their tendency towards atmospheric persistence and mobility, and to obtain a persistence index in air and an LRT index. These indexes were also modelled by molecular descriptors, thus allowing a preliminary screening of new compounds.

Air Movements↗
PubMedDate not supplied

Flexible sigmoidoscopy as a colorectal cancer screening test in the general population: recruitment phase results of a randomized controlled trial in Lombardia, Italy.

UNLABELLED: A two arm multicentre randomized controlled trial is in progress to evaluate the efficacy of flexible sigmoidoscopy (FS) as a screening test for colorectal cancer in the general population. AIMS: To determine the acceptance rate and feasibility of FS as a colorectal cancer screening test in average-risk asymptomatic volunteers. Average-risk, asymptomatic subjects, aged 55-64 years and assisted by 244 general practitioners (GPs) in Lombardy, Italy, were invited by postal questionnaire (PQ) to enter a study for the prevention of colorectal cancer and asked to indicate their interest in, and willingness to undergo, screening: those responding positively were randomized to the intervention or control arms. GPs were trained in colorectal cancer screening and proposed free FS to their patients randomized to the intervention arm. All sigmoidoscopies were performed by experienced endoscopists. Small polyps were removed at FS. Colonoscopy was indicated for high risk polyps (size more than 5 mm, more than two adenomas, villous histology, severe dysplasia or malignancy). 40,945 subjects were invited. 667 PQs were returned undelivered due to postal failure. 7,892 (19.59%) subjects responded, 2,116 of whom (26.81%) were not included, presenting 1 or more exclusion criteria. We randomized 5,778 volunteers and performed 1,582 sigmoidoscopies out of 2,885 subjects in the intervention arm (54.84% acceptance rate). Although the screening procedure had a good attendance rate in the intervention group, involvement of the people invited was lower than expected. Future FS screening programmes will require a keener focus on recruitment strategies, mainly with participation of GPs.

Colorectal Neoplasms↗
PubMedDate not supplied

[Feasibility of exeresis. Controversial aspects in the surgery of carcinoma of the pancreas].

Pancreatic cancer has a dismal prognosis also after resection with a 5 years' survival of about 5% in operated patients. The main clinical issue in patients with a malignant tumour is to identify the ones that would benefit from a surgical treatment. Resectability of pancreatic cancer has not an absolute value and the possible advantages in terms of prognosis and quality of life should be balanced with surgical mortality and morbidity. For this reason the management of this disease involves a multidisciplinary approach and the surgeon should join with the other specialists in experienced oncology centers. En exhaustive evaluation of the following prognostic factors should be made pre and intra-operatively to better define life expectancy with or without resection: Histotype: endocrine tumours and cystadenocarcinoma have, in general, a better prognosis, Staging: JPS classification has a better prognostic value if compared to the UICC. Completeness of the resection. Biological characteristics of the tumour. The main variables to be considered for the exeresis are: Size and local growth of the tumour (also considering the involvement of vessels, retroperitoneum and pancreatic capsule). Liver or peritoneal metastases: for this laparoscopy has a key role for staging. Histologic confirmation: differential diagnosis with chronic pancreatitis is sometimes difficult and every attempt should be made to have a pre-operative histology. Vascular invasion is one of the main contraindications to surgery and an exhaustive evaluation of vascular involvement should be considered mandatory. Lymph nodal involvement, in general, represents a negative prognostic factor even if Japanese authors claim that a radical resection can be performed in case of positive nodes in the peripancreatic area, if a complete lymphadenectomy is carried out.

Carcinoma↗