PubMed Health⌕ Search

Biomedical subjects

A Severini

Publications and source records attributed to A Severini.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Prognostic factors after percutaneous transhepatic biliary drainage].

The authors reviewed the clinical charts and the radiographic files of 93 patients with obstructive jaundice--in 86 cases due to neoplasm--treated with PTBD. The test of differences from survival curves was used to identify the clinical parameters predictive of short survival after PTBD. The difference in survival curves was significant relative to serum indirect bilirubin (cut point: 7.6 mg%), to serum cholinesterase (cut point: 1290 mU/ml), to white blood cell counts (cut point: 8600/mm3), to blood urea nitrogen (BUN) levels (cut point: 60 mg%). Because of the marked negative prognostic value of high BUN levels, our data seem to indicate that PTBD should not be performed when severe renal insufficiency is present. Other parameters correlated with a short survival after PTBD were the histotype of metastasis (in comparison with the other ones), and large neoplastic volume (in comparison with a small and a medium ones). Through pre-PTBD radiological and laboratory data analysis, a group of patients can be selected in whom the procedure will increase neither well-being nor survival, as plotted against those patients who are likely to benefit from biliary drainage.

Bile Duct Neoplasms↗
PubMed1990

Interconversion of replication and recombination structures: implications for terminal repeats and concatemers.

Replication and recombination structures can be interconverted by branch-migration. Using this simple concept a novel mechanism is proposed for generating concatemers through an initial single-strand DNA invasion into a duplex. Only DNAs with terminal repeats can form concatemers, and Herpes Simplex Virus DNA replication is considered in detail. The model is more parsimonious than other models such as Watson's for concatemer formation.

Base Sequence↗
PubMed1990

[Use of Severini's coaxial catheters in gastrointestinal interventional radiology].

The growing importance of gastrointestinal interventional radiology has led to the development of new instruments and materials for the different proposed purposes. The authors present a set consisting of two coaxial catheters which was created for percutaneous transhepatic biliary drainage (Severini set). Its easy handling, adaptability and tolerability make it a versatile instrument in the hands of interventional radiologists for positioning large-calibre catheter (9-14 F) in deep sites. Hereafter are reported the results in 29 patients treated with different therapeutic aims and the use of the set for different pathologies. The catheters allowed a complete resolution of the collections communicating with the gastrointestinal tract in 4 of 5 patients. The catheter was inserted as a feeding tube in 22 patients. Finally, it was used as a gastrostomy catheter in 2 patients. Neither early nor late complications due to insertion or use of this set were observed.

Adenocarcinoma↗
PubMed1990

Double contrast small bowel enema in a case of selective duodeno-jejunal amyloidosis.

Double contrast small bowel enema in a patient with selective amyloidosis of the duodenum and jejunum revealed an unusual radiologic pattern, mimicking multiple polyposis. Many submucosal polypoid lesions, sessile or pedunculated, were scattered throughout the duodenum and proximal jejunum. The lesions had smooth borders and did not show any retraction at the base. Other typical radiologic patterns of intestinal amyloidosis described in the literature were not observed in the present case. Differential diagnosis from multiple polyposis and diffuse lymphoproliferative neoplastic diseases is discussed.

Aged↗
PubMed1989

Inherited diseases in North American Mennonites: focus on Old Colony (Chortitza) Mennonites.

The patterns of migration and the genetic disorders occurring among North American Mennonites are reviewed, and inherited conditions recently recognized in a religious and genetic isolate, the Old Colony (Chortitza) Mennonites, are described. Old Colony Mennonites are of Dutch/German origin and descend from approximately 400 founding families who settled in the Old Colony, Chortitza (the Ukraine, USSR) in the late 1700s, and then migrated to Canada and Central and South America in the past century. We investigated over 6 generations of a Canadian Old Colony kindred in which there was extensive intermarriage, and in whom 28 individuals developed diabetes mellitus. Insulin-dependent diabetes mellitus (IDDM) occurred in 14 affected individuals in 10 closely related sibships; the 11 living IDDM patients were all concordant for the immunogenetic marker HLA-DR4. Fourteen close relatives had other disorders of carbohydrate metabolism, including gestational diabetes and non-insulin-dependent diabetes mellitus. Other close relatives had autoimmune diseases, including rheumatoid arthritis, hyper- and hypothyroidism, multiple sclerosis, and red cell aplasia. Other inherited diseases, including Alport syndrome, congenital defects, and inborn errors of metabolism were also found in the kindred. In the almost exclusively (99%) Old Colony Mennonite public health district in which the kindred was ascertained, there were multiple cases of Tourette syndrome, of malformations (including congenital heart defects and cleft lip +/- palate), and familial clusters of inborn errors of metabolism. We report this Old Colony (Chortitza) Mennonite isolate because 1) there are large familial aggregations of tissue-specific autoimmune diseases, malformations, inborn errors of metabolism, and of some other conditions whose genetic basis is still unknown; 2) there are multiple cases of rare genetic conditions, 3) we have established a computerized genealogic data base on over 1,000 kindred members as well as a cryopreserved lymphocyte/DNA bank on over 100 closely related individuals with various genetic conditions; and 4) this religious isolate, which extends across North, Central, and South America, offers an excellent opportunity for studying the epidemiology and molecular genetics of both common and rare inherited diseases.

Adrenal Hyperplasia, Congenital↗
PubMed1989

[Percutaneous transhepatic biliary drainage. Complications and their treatment].

In the present series of 296 PTBDs in 281 patients, 103 complications of different degree developed (34.7%). Early complications directly connected to the procedure (32/296 = 10.8%) and late complications generally due to malfunctioning of the catheter or progression of the disease (71/296 = 23.9%) are analyzed. Caveats to prevent complications, therapeutic procedures to resolve them, as well as obtained results are reported. On the whole, major complications directly related to the procedure are present in a small percentage and the procedure appears well tolerated also in patients with poor general conditions.

Bile Duct Neoplasms↗
PubMed1989

[Cholangitis and percutaneous biliary drainage].

The binomial PTBD-cholangitis often stands under different and sometimes even opposite relations. Among its indications the procedure lists, the treatment of cholangitis which, on the other hand, may be itself a complication of biliary drainage. The present work proposes a critical review of cholangitis-PTBD correlations, from an ordinary clinical-radiological point of view. Different pathogenetic hypothesis of cholangitis (inflammation, cholestasis, surgical manipulation) are discussed together with risk factors (impaired macrophagic-phagocytic system, immunosuppression, wide neoplastic liver involvement, multiple intrahepatic ductal obstructions, chronic liver diseases, aged patients, etc.). The authors also report about prevention and treatment of septic complications which must be carried out following technical and therapeutic strategies, such as chemoprophylaxis and focused antibiotic therapy according to bile culture samples, slow injection of small amounts of contrast medium, peripheral branches approach, gentle handling of catheters and guidewires, flushing with saline solutions and brushing of the catheter itself, and finally use of large gauge catheters in the presence of bile sludge.

Bacterial Infections↗
PubMed1989

[Radiologic examination in assessing the response to chemoradiotherapy of esophageal spinocellular carcinoma].

Squamous cell carcinoma represents more than 90% of esophageal cancers; its prognosis is still extremely severe. A treatment consisting in the combined use of preoperative chemotherapy and radiotherapy is now in course of experimentation at Istituto Nazionale Tumori, Milan. Over a period of 28 months (July 1985 to October 1987), 21 patients with 22 lesions (stage III) underwent a double contrast study of the esophagus, both before and after therapy. The radiological evaluation of the lesions after treatment was compared with the pathological diagnosis. Radiological diagnosis has been confirmed in 86.3% of cases (19/22 lesions) as far as mucosal detailing was concerned. On the contrary, radiological evaluation has proven unreliable as far as submucosal layers were concerned. No radiological false positives have been observed.

Adult↗
PubMed1989

[Postoperative radiologic follow-up of rectocolonic anastomoses. The visualization of fistulous passages after evacuation].

The early postoperative study of colo-rectal anastomoses is a common diagnostic procedure with symptomatic patients which is extended to asymptomatic patients by some authors. Eighty-eight anastomotic fistulas were early diagnosed after intervention in 316 patients who underwent a water-soluble contrast enema. Four out of these fistulas (4.5%) could not be demonstrated at complete filling on X-ray, but were only opacified on radiographs taken after the spontaneous evacuation of contrast medium. The increase in endoluminal pressure due to the evacuation and the lack of balloon catheter probably play a role in allowing these fistulas to be visualized.

Anastomosis, Surgical↗
PubMed1989

Genetic conditions among Canadian Mennonites: evidence for a founder effect among the old colony (Chortitza) Mennonites.

Distinctive disease patterns exist among Canadian Old Colony (Chortitza) Mennonites. This religious and genetic isolate is of 16th century Dutch/German ancestry. The group originated in the Netherlands, then settled in the Vistula delta area of western Prussia for 200 years. A small number of founding families later migrated to Chortitza, the "Old Colony", in the Ukraine in the late 18th/early 19th century, where they remained a distinct genetic isolate. This group has come to Canada over the past 100 years. The more conservative Canadian Mennonites of Chortitza descent practice strict endogamy, have a large family size and live predominantly in rural public health subdistricts in the four western provinces, and in southern Ontario. The world's largest reported familial aggregations of insulin-dependent diabetes mellitus, of autoimmune diseases and of Tourette syndrome were initially ascertained in a small northern Alberta public health subdistrict. Clusterings of malformations, inborn errors of metabolism, and other conditions were also found in the subdistrict, and in group descendents living in other provinces. A founder effect, or genetic drift, accounts for the familial aggregations of autosomal recessive and dominant conditions, some diseases of multifactorial determination, and other inherited conditions in Canadian kinships descending from this ancestral group. The medical literature on genetic conditions among Canadian Mennonites is reviewed and re-evaluated in the light of this information. There is biochemical, serologic, and molecular biologic evidence in favour of genetic homogeneity amongst patients with certain inherited conditions in this special population group. This genetic isolate offers potential for the study of the genetic epidemiology and molecular biology of inherited diseases. A computerized genealogic data base on about 1400 group members, as well as a cryopreserved lymphocyte/DNA bank on over 100 individuals with genetic conditions has been established in this special population group.

Alberta↗
PubMed1988

Unusual clustering of diseases in a Canadian Old Colony (Chortitza) Mennonite kindred and community.

We investigated a large Old Colony (Chortitza) Mennonite kindred with branches across Canada. Six generations of the kindred were traced. There was intermarriage among numerous family members. Insulin-dependent diabetes mellitus (IDDM) was identified in 10 members; all 7 living patients were found to carry the immunogenetic marker HLA-DR4. Nine other close relatives had disorders of carbohydrate metabolism, including gestational diabetes mellitus and non-insulin-dependent diabetes mellitus progressing to insulin use. Ten other relatives had autoimmune diseases, including rheumatoid arthritis, hyperthyroidism, hypothyroidism and multiple sclerosis. Cases of Alport's syndrome, congenital malformations, inborn errors of metabolism and unusual malignant diseases were also found in the kindred. In the small Alberta community in which the kindred was ascertained there were people of Old Colony Mennonite descent with genetic conditions such as Gilles de la Tourette's syndrome and congenital malformations, including congenital heart disease. This kindred represents the largest reported familial aggregation of IDDM. This disease and other disorders of carbohydrate metabolism occur in the context of a strong familial predisposition to autoimmune disease. Study of this family may permit empiric testing of proposed models of inheritance of diseases of complex origin such as IDDM. We report this Old Colony (Chortitza) Mennonite community because it is one of the settlements populated by this religious and genetic isolate, which extends across Canada and Central and South America and affords opportunities for the study of both common and rare inherited diseases.

Adolescent↗
PubMed1988

Sensitivity of Hemoccult test for large bowel cancer in high-risk subjects.

From 1979 to 1982, 1233 symptom-free subjects at high risk for colon cancer because of family history and/or personal history of bowel neoplasia (cancer or adenomatous polyp) were examined with a guaiac test (Hemoccult II) for occult blood in stools. The test was positive (H+) in 98 subjects (7.9%). Endoscopy was subsequently performed on 86% of the H+ and on 64% of the H- subjects. Of 20 in invasive cancers found, 15 had been H+ [75.0%; 95% confidence interval (CI), 54.3-91.0%]. Of 96 patients with adenoma(s), 23 were H+ (24%; 95% CI, 16.0-33.0%). However, the sensitivity for adenomas was higher in patients with multiple adenomas or with a single adenoma measuring 2 cm or more in its largest diameter (37.5%; 95% CI, 21.8-54.7%). Of 699 subjects free of neoplastic lesions at endoscopy, 47 had been H+, ie, false positive (6.7%; 95% CI, 5.0-8.7%). Adjusting for differential compliance of H+ and H- subjects to endoscopy, a corrected estimate for sensitivity would be 69% for cancer and 19% for adenomas; the corrected estimate for the false-positive rate would be 5%.

Adenoma↗
PubMed1988

[Gastrointestinal interventional radiology. Technics and preliminary results].

Gastrointestinal interventional radiology allows the positioning of feeding tubes in difficult situations, as well as the balloon dilatation of stenoses and the transintestinal drainage of fistulas and collections, with some advantages over endoscopic and surgical procedures. In the present series feeding tubes were positioned in 26 patients, both to get over the strictures in the upper gastrointestinal tract and to exclude fistulous tracts or anastomotic leaks from alimentary transit. Balloon dilatation was performed in 10 patients with stenoses of different aetiologies, at different levels of the gastrointestinal tract: in all cases the clinical symptoms diminished. All the 7 non-neoplastic stenoses were successfully treated (follow-up 6-27 months). The draining of abscesses through the enteric fistulous tract did allow the reduction/resolution of all collections in a short time. These procedures are simple and safe, and help to reduce the interval between diagnosis and therapy. Their failure does not prevent the use of other therapeutic procedures.

Abscess↗
PubMed1988

The occurrence of cholangitis after percutaneous biliary drainage: evaluation of some risk factors.

Sepsis of the biliary tract is often reported after percutaneous transhepatic biliary drainage (PTBD) and is considered a life-threatening condition. The authors studied 39 patients with biliary stenosis (35 with neoplastic stricture and four with benign disease) with the purpose of identifying some factors possibly associated with a higher risk of cholangitis. None of the patients complained of biliary sepsis at the first clinical examination. Several factors were taken into account and were statistically tested according to Miettinen rate ratios to differentiate patients in whom cholangitis would consequently develop: nature, site and extent of basic disease, type and functioning of PTBD, skin contamination at puncture site of PTBD, and bile contamination at PTBD and at follow-up. The presence of bacteria in the first bile (31.5%) was not related to a higher risk. All subjects showed bile contamination after PTBD, but cholangitis developed in only 15 patients, and it was always supported by enteric microorganisms. When we compared patients with cholangitis and subjects without infection, it was possible to demonstrate a statistically significant association of cholangitis and the following: nature of the stricture, presence of multiple intrahepatic biliary obstruction, neoplastic invasion or compression on the duodenum, and presence of Staphylococcus aureus on the skin at puncture site at drainage.

Adult↗
PubMed1987

A new set for transhepatic insertion of large caliber catheters for biliary drainage: technical and clinical report.

An original set for percutaneous insertion of large caliber (12-16 French) biliary drainages is described. The results obtained in the 70 patients submitted to biliary drainage with late complications due to malfunction of the standard 8.3 or 10 F catheters show the advantage of the set described. The correction of unsatisfactory levels of bilirubinemia was obtained in 100% of cases, the resolution of recurrent cholangitis in 84.2% and of bile leakage on the skin in 46.7%. The large caliber and the large side holes of the catheter, together with its length and its easy handling, allow resolution of many different problems of insufficient drainage present in patients with neoplastic involvement of bile ducts.

Bile↗
PubMed1987

Increase in intracellular Na+: transmembrane signal for rejoining of DNA strand breaks in proliferating lymphocytes.

Two early events in the mitogen-induced entry of murine splenocytes into proliferation are (a) a rapid rise in influx of Na+, causing its total internal concentration to increase by 42 +/- 7% within 2 h of culture with concanavalin A (Con A), and (b) rejoining of some 3000 DNA strand breaks per diploid genome within the same period. Con A did not induce rejoining in low Na+ (less than 9 mM) medium, but the process began directly when Na+ was added, at its usual concentration, to the growth medium. Incubation of cells with ouabain, an inhibitor of the Na+K+-ATPase, or monensin, a Na+ ionophore, caused an increase in the internal Na+ concentration in normal, but not in low, Na+ medium. In the former (but not in the latter) medium, both ouabain and monensin caused rejoining of the DNA strand breaks to occur in resting lymphocytes, i.e., in the absence of mitogen. Stimulation of splenocytes with Con A also resulted in a rapid but transient increase in the level of intracellular free Ca2+. This effect was also observed in the absence of extracellular Na+; however, deprivation of extracellular Ca2+ completely abolished this effect. Moreover, the intracellular free Ca2+ level was significantly higher in cells suspended in Na+-free buffer or medium. Since the Con A-induced rejoining of DNA strand breaks occurred in the absence of extracellular Ca2+ and removal of extracellular Na+ had no inhibitory effect on the Con A-induced increase in the level of intracellular free Ca2+, the Con A-stimulated repair could not have been mediated by the initial increase in Ca2+ influx. The early mitogen-induced increase in the internal Na+ concentration is a necessary and sufficient signal for the rejoining of breaks, an event that must occur before the proliferating lymphocytes can replicate their DNA.

Animals↗
PubMed1987

Sodium ion influx in proliferating lymphocytes: an early component of the mitogenic signal.

Stimulation of pig peripheral blood lymphocytes with concanavalin A (Con A) provoked a rapid increase (two- to threefold) in the rate of ouabain-inhibitable K+ uptake observable within 3-10 min of stimulation with mitogen. At least two phases can be distinguished in the activation of the Na+/K+ pump: the early phase (till 3 h) is characterized by an unaltered number of ouabain binding sites and the later phase (noted at 5 h) by an increased number of such sites. Both K+ efflux and influx increased to the same extent, thereby maintaining [K+]i at the same level as in resting cells (120 mM). Within 3 min of addition of mitogen, the rates of total and amiloride-inhibitable Na+ uptake went up two- and fourfold, respectively, thus resulting in rapid increase in [Na+]i from 20 to about 50 mM. Activation of the Na+/K+ pump was not observed when the cells were stimulated with Con A in low Na+ medium (9 mM), nor did the usual rise in [Na+]i occur. When monensin (30 microM), a Na+/H+ ionophore, was added to resting cells, an increase in both [Na+]i and active K+ uptake occurred in normal medium but not when cells were suspended in low Na+ isotonic buffer. Amiloride (500 microM), on the other hand, prevented both the Con A-induced increase in [Na+]i and the activation of the Na+/K+ pump. Despite complete inhibition of the Na+,K+-ATPase in the presence of ouabain (1 mM), Con A activated the amiloride-inhibitable Na+ uptake in the usual way. In mouse splenocytes stimulated with Con A, there was also a parallel rise in both [Na+]i and active K+ uptake but this took considerably longer to occur than was the case in pig peripheral blood lymphocytes. Increase in both ionic fluxes, the former passive and the latter active, is essential to the entry and maintenance of the cells in proliferative cycle.

Amiloride↗