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Biomedical subjects

R Rossi

Publications and source records attributed to R Rossi.

At least 397 records · Page 22Linked to original sources
PubMed1989

In vitro effects of estrogen on tgb and c-myc gene expression in normal and neoplastic human thyroids.

The authors investigated the effects of 17 beta-estradiol (E) and thyroid-stimulating hormone (TSH) on tgb (coding for thyroglobulin), c-myc RNA levels, and [3H]thymidine (thy) incorporation in suspension cultures of normal, adenomatous and carcinomatous human thyroid follicles. The cultured follicles showed decreased tgb RNA and enhanced c-myc RNA levels. In the culture of normal and adenomatous samples E caused a significant increase of [3H]thy incorporation and tgb RNA levels, with no effect on c-myc RNA levels. No effect of E was observed in the carcinomatous thyroid culture. TSH induced a significant increase of [3H]thy incorporation and c-myc expression only in adenoma cultures and a significant increase of tgb RNA levels in both normal and adenomatous samples. TSH had no effect on the carcinoma. The results show that E, like TSH, stimulates in vitro the expression of the tgb gene in differentiated cells, without stimulating the expression of the c-myc proto-oncogene, suggesting a possible action of E on normal thyroid function and perhaps growth, even if not associated with increased c-myc expression.

Cell Division↗
PubMed1989

Identification of a trypanocidal factor against Trypanosoma equiperdum in normal human serum.

Normal human serum (HS) contains trypanolytic activity and agglutinins to Trypanosoma equiperdum, while such activities are not found in sera from a range of animals susceptible to infection. HS given to T. equiperdum-infected mice caused a rapid decrease in the number of circulating trypanosomes and protection from lethal infection. Trypanolytic activity of human serum was found to be associated, after DEAE chromatography and Sephadex G-200 gel filtration, with the fraction containing 19S antibodies. Immunofluorescence assays confirmed a binding of human IgM and C1q complement component onto the surface of T. equiperdum. Anti-T. equiperdum activity of HS was specifically directed to T. equiperdum surface components and not to some mouse serum components adsorbed on parasites during the growth in the host, because HS adsorbed in vivo in CD-1 mice retained full protective and agglutinating properties. Trypanocidal activity appears in human serum about the 7th month after birth and persists until late in life. On the contrary, human purified high-density lipoprotein had no significant in vitro or in vivo trypanocidal activity. In conclusion, strong natural anti-T. equiperdum activity in human serum was mainly mediated by natural antibodies of the IgM class. The presence of natural IgM active against T. equiperdum in HS could represent one of the natural mechanisms of resistance of refractory hosts against trypanosome infections. This phenomenon provides further evidence that host specificity of trypanosomes may be partly conditioned by the presence of natural antibodies.

Agglutination Tests↗
PubMed1989

FCE 22101 and FCE 22891: in-vitro antibacterial activity at concentrations simulating human plasma levels following intravenous, intramuscular and oral administration.

The plasma concentrations of FCE 22101 observed following slow intravenous infusions (1 and 4 h), intramuscular injection and after oral administration of the prodrug FCE 22891 were simulated in a glass chamber containing bacterial cultures. The bacteria used were Staphylococcus aureus ATCC 13709, Staph. aureus 2101 (methicillin-resistant), Streptococcus faecium ATCC 8043, Escherichia coli ATCC 12407, Enterobacter cloacae 1321E and Ent. cloacae P99 (cefazolin-resistant). Addition of FCE 22101 was found to result in a reduction in number of all bacterial strains except Str. faecium, with which only bacteriostasis was observed.

Administration, Oral↗
PubMed1989

Activity of FCE 22891 compared with cefuroxime axetil and cefixime in pulmonary and subcutaneous infections in mice.

The therapeutic activity of FCE 22891 was compared with that of two new oral cephalosporins, cefuroxime axetil and cefixime against Streptococcus pneumoniae respiratory infection and subcutaneous abscesses induced by mixed aerobes and anaerobes in mice. In experimental pneumonia FCE 22891 was the most active antibiotic. In aerobic abscesses FCE 22891 proved the most active agent in infections induced by methicillin susceptible and resistant Staphylococcus aureus while all three compounds were very active, against Str. pyogenes. In abscesses caused by Gram-negative bacteria, FCE 22891 showed good and constant efficacy. Cefixime was the most active drug against the two susceptible strains of Escherichia coli and Enterobacter cloacae and also against resistant Esch. coli but was inactive against a strain of Ent. cloacae that produced cephalosporinase. Cefuroxime axetil was less active than the other two drugs against Gram-negative bacteria with adequate efficacy only against a susceptible strain of Ent. cloacae. FCE 22891 was more effective than cefixime and cefuroxime axetil in preventing and reducing the size of abscesses induced by Bacteroides fragilis 101. We conclude that FCE 22891, despite its short half life of 6 min in mice, exerts comparable and sometimes better activity than the two oral cephalosporins characterized by longer half lives.

Abscess↗
PubMed1989

Immunosuppressive effect of cyclosporin A on resistance to systemic infection with Candida albicans.

We studied the influence of cyclosporin-A (Cy-A) on resistance of mice to systemic infection with Candida albicans. Cy-A clearly inhibited resistance to C. albicans. The effect was dose-dependent and time and route of administration of the drug were important. This immunodepressive effect was due, at least in part, to an impairment of polymorphonuclear leucocyte (PMNL) candidacidal activity, as demonstrated in vitro by a reduction of phagocytic and cytotoxic activity and in vivo by protection when PMNL from untreated mice were transferred into cyclophosphamide-treated hosts challenged with C. albicans. The decreased activity of PMNL could be partly restored by adoptive transfer of normal T-lymphocytes into Cy-A-treated mice, as well as by exposure of PMNL to gamma-interferon (IFN-gamma) in vitro.

Animals↗
PubMed1989

On the crustacean hosts of larval acanthocephalan parasites of fishes from a coastal lagoon of River Po Delta.

A total of 4664 crustaceans of 2 species of gammarids (Gammarus insensibilis Stock, G. aequicauda Martynon) were collected and examined in search of larval helminth parasites. Larvae of Telosentis exiguus Von Linstow 1901 (Acanthocephala) were found in 6 out of 2806 G. insensibilis so far examined. This is the first record of an intermediate host for T. exiguus, of which a definitive host in Italy has already been indicated by us in Atherina boyeri.

Acanthocephala↗
PubMed1989

No flow or low flow? A study of the ischemic marker creatine kinase BB after deep hypothermic procedures.

Twenty-seven children with complex congenital heart malformations necessitating early repair were studied before and after deep hypothermic procedures. The children were allocated into two groups. One group underwent total circulatory arrest (40 +/- 6 minutes). In the other group perfusion was maintained during deep hypothermia but reduced a 25% of normal at normothermia. The temperature was reduced to 15 degrees C (nasopharynx) in both groups with a combination of topical and core cooling. To study cerebral injury, were made serial measurements of creatine kinase isoenzyme BB from arterial samples before and for 8 hours after the deep hypothermic procedure. Creatine kinase isoenzyme BB increased after both procedures from 4.3 +/- 0.9 ng/ml to 10.4 +/- 1.8 ng/ml in the circulatory arrest group and from 2.8 +/- 0.7 ng/ml to 9.9 +/- 1.9 ng/ml in the low-flow group (no significant difference). The results were analyzed in relation to age, size, study group, hemoglobin, blood glucose, and blood gases. The creatine kinase BB levels were positively related to preoperative hemoglobin and blood glucose values before the hypothermic procedures.

Blood Glucose↗
PubMed1989

[Operative central unit for coordinating the emergencies-urgencies department. Proposal for a mini-unit to solve the problems caused by the relation between volunteer associations and the public structure].

One of the most important problems, of very difficult solution, in organizing an A/E department is to co-ordinate the emergency in the field. This peculiar task is carried on by an operative central station, the core of an A/E Dept. The organizer in Arezzo try to find out the efficiency and a cost benefit ratio of this central station and try to jump over an historical hindrance to operate by mutual consent with voluntary service. This seems to be possible with the technological development of telephone system and broadcast system. Staff, technical qualifications, connections, reception, modulation, sorting out of different calls are discussed in conjunction with problems of health education concerning the operative central station that coordinates A/E Dept in Arezzo.

Emergency Medical Service Communication Systems↗
PubMed1989

[Survey carried out by land of the intervention time for territorial health care].

While organizing the Catchment area of A/E Department in Arezzo, a recording of intervention time of prehospital care system (primary transport) was made by land. The analysis recorded that one third of the field on the Catchment area of the A/E Dept was in a red dangerous zone reachable in 15 minutes and more. Such analysis confirmed the importance of local operation bonds all for a correct redistribution of ambulances in the Catchment area and a rational choice of vans and staff suitable for an advanced life support only where and when really necessary.

Ambulances↗
PubMed1989

[Diagnosis of the nature of biliary stenoses: role of exfoliative cytology by external biliary drainage].

The use of percutaneous transhepatic biliary drainage (PTBD) has allowed the development of new diagnostic examinations, such as biliary exfoliative cytology. This is extremely important in patients with biliary tract strictures, in order to obtain a diagnosis about the real nature of the stricture. Forty-nine patients underwent exfoliative biliary tract cytology from bile samples. Exfoliative cytology was performed on bile samples taken at different times for each patient. The results of our study proved this examination to be highly specific (there were no false positive samples), although the diagnostic sensitivity was not as high (63.9%). It is important to underline that whenever the epithelium of the biliary tract is involved by neoplasm, the result of examination is always positive. These data may be useful to choose an appropriate surgical procedure.

Bile↗
PubMed1989

Elective deep hypothermia with total circulatory arrest: changes in plasma creatine kinase BB, blood glucose, and clinical variables.

Serial measurements of a marker of brain ischemia, creatine kinase isoenzyme BB, were performed in arterial and internal jugular venous blood from 20 infants younger than 1 year of age before and during the first 20 hours after deep hypothermic total circulatory arrest procedures. A two-site monoclonal method was used, and the results were analyzed in relation to age, size, type of cardiac lesion, hemoglobin level, blood glucose level, pH, and duration of the total circulatory arrest. The creatine kinase BB concentrations increased after the arrest, more so in venous than in arterial blood, from 3.2 +/- 0.5 ng/ml to 17.5 +/- 4.5 in arterial blood and from 3.5 +/- 0.5 ng/ml to 18.1 +/- 5.8 in venous blood. Arterial-venous concentration differences correlated with venous concentrations (r = 0.92, p less than 0.01). The duration of the arrest correlated with creatine kinase BB concentrations during reperfusion with correlation coefficients between 0.50 to 0.90 depending of what sequence of the 20-hour sampling period was analyzed. The best correlation was obtained during the first 4 hours of reperfusion. Age, size of the child, and preoperative cyanosis correlated with postoperative creatine kinase BB but were less important than the arrest time, blood glucose level (r = 0.62, p less than 0.01), pH (r = -0.78, p less than 0.01), and hemoglobin level (r = 0.76, p less than 0.01) during reperfusion. It is suggested that a different control of blood glucose level and pH during reperfusion may be of importance to reduce biochemical signs of cerebral dysfunction after deep hypothermic total circulatory arrest procedures.

Blood Glucose↗
PubMed1988

Comparison of the performances of an automated arrhythmia detector working on original and virtual ECG tracings.

Two approaches can be taken to improve the performance of an automatic arrhythmia detector: perfecting the detection algorithms or improving the quality of the investigated traces by preprocessing the original traces. This paper reports on the results of a data preprocessing approach. Preprocessing consists in constructing new traces, which we call virtual. They are mathematically obtained from the original traces and referred to the dominant cardiac electric axis. The classifications obtained with an arrhythmia detector using both virtual and original traces are presented and discussed. By comparing the performance indices obtained under the two different conditions, it can be seen that a diagnosis based on the virtual traces is as acceptable as one based on the original traces. This result should be judged as favorable, since the algorithm was not adjusted or calibrated to the virtual traces, while those who developed it had certainly calibrated the parameters to the original traces.

Algorithms↗
PubMed1988

Sorbitol malabsorption in normal volunteers and in patients with coeliac disease.

Sorbitol is a hexahydroxy alcohol used as a sugar substitute in many dietetic foods and as a drug vehicle. Previous studies have suggested that sorbitol ingestion may be an additional cause of non-specific gastrointestinal distress. We evaluated sorbitol malabsorption in 30 healthy volunteers, seven patients with untreated coeliac disease and nine patients with coeliac disease on a gluten free diet, using a four hour H2 breath test. After ingestion of test solutions containing sorbitol 10 and 20 g and of four sweets (6.8 g sorbitol), 90%, 100%, and 62% of healthy volunteers, respectively had significantly raised H2 excretion, indicating malabsorption of sorbitol. Of all healthy subjects tested, 45% after 10 g, 100% after 20 g, and 50% after four sweets complained of symptoms of carbohydrate intolerance during the eight hours after sorbitol. After a 5 g dose given at concentrations of 2%, 4%, 8%, 16%, malabsorption was shown in 10%, 12%, 22%, and 43% of the healthy volunteers. Symptoms of intolerance at 5 g were experienced only at concentrations of 8% and 16%. Unlike healthy volunteers and coeliac patients on a gluten free diet, 100% of untreated coeliacs malabsorbed a 2% solution of 5 g sorbitol. These results show that malabsorption and intolerance of sorbitol may result from ingestion of doses and/or concentrations usually found in many foods and drugs; they underline the need to consider this as a possible and hitherto underestimated cause of gastrointestinal symptoms.

Adult↗
PubMed1988

An expanded view of risk-group definition in differentiated thyroid carcinoma.

There continues to be controversy about every aspect of management of differentiated thyroid carcinoma. In an age-based risk group previously described, low-risk patients made up 62% of cases and had a death rate of only 1%. Recent reports from the Mayo Clinic have expanded the concept of the low-risk group to include 86% of all cases with a 2% death rate by utilizing several anatomic and pathologic criteria of risk. We offer here another multifactorial system for the identification of low-risk patients who made up 89.4% of all patient seen between 1961 and 1980 and who have a death rate of only 1.8%. The resultant high-risk group constitutes 11% of cases but carries a 46% mortality rate. The risk-group definition is completely clinical and is based on age, presence of distant metastases, and the size and extent of primary cancer. It can be used confidently at the operating table to select conservative surgical procedures in patients with negligible risk of death. Through the succeeding decades analyzed, from 1941 to 1980, the effectiveness of this clinical categorization has increased substantially in separating patients at high and low risk, so that a mortality rate ratio of 26:1 now exists between high- and low-risk groups, respectively.

Adult↗