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Biomedical subjects

C Rossi

Publications and source records attributed to C Rossi.

At least 217 records · Page 12Linked to original sources
PubMed1993

Inhibition of Fc gamma receptors in the plasma of subjects with Down's syndrome.

Subjects with Down's syndrome have several immunological abnormalities. We examined the sera of 29 subjects with Down's syndrome for the presence of Fc gamma receptor blocking and for the presence of anti-ssDNA antibodies by EA rosette inhibition. Fifty-five percent of Down subjects had levels of inhibition above the upper limit of normality in comparison to 7% of normal controls. The finding that after polyethylene glycol precipitation of selected sera giving high levels of EA rosette inhibition there was a reduction or a disappearance of the EA rosette inhibition could indicate that the blocking factors detected behaved as immune complexes. Since almost all subjects with anti-ssDNA antibodies also had elevated values of EA rosette inhibition, a role for immune complexes eventually formed with autoantibodies in an Fc-mediated immunoregulatory system is suggested.

Adolescent↗
PubMed1993

The establishment of underdominant chromosomal rearrangements in multi-deme systems with local extinction and colonization.

The fate of an underdominant chromosomal mutant was investigated in multideme models with high rates of local extinction and colonization. Four models with different patterns of colonization (number of colonists and place of origin of colonists) were studied by performing a large number of computer simulations with the Monte Carlo method for several sets of values of the following parameters: coefficient of selection against the heterozygote, extinction rate of each deme, deme size, and number of demes. The probability of the newly arisen rearrangement being established in the multi-deme system depends strongly on the pattern of colonization, other things being equal. In the three models in which there is absent or scarce mixing of gene pools of different demes when a new deme is founded, the fixation probability of the new chromosomal rearrangement is rather close to that calculated by R. Lande (1979, Evolution 33, 234-251; 1985, Heredity 54, 323-332), which is equal to the corresponding probability in a single deme divided by the number of demes. In the model with extensive mixing of gene pools of demes, the corresponding probability is lower (considerably in some cases). Furthermore, in the models where the fixation probability is higher, the analysis of the time of the process leads to the conclusion that in systems consisting of a large number of demes, overlapping of several different processes of fixation of chromosomal rearrangements occurs.

Animals↗
PubMed1993

Interrupted aortic arch and aortopulmonary window: one-stage repair in the first week of life.

Aortic arch interruption associated with an aortopulmonary window is a rare congenital malformation that needs an early diagnosis and surgical treatment to avoid irreversible pulmonary lesions. Here we describe a case of a successful one-stage surgical repair in a 3-day-old neonate, without the use of prosthetic material, for the correction of the aortic arch interruption.

Aorta, Thoracic↗
PubMed1993

Expression of non-conserved regions of the S genome segments of three hantaviruses: evaluation of the expressed polypeptides for diagnosis of haemorrhagic fever with renal syndrome.

Haemorrhagic fever with renal syndrome (HFRS) is a serious and often fatal disease caused by viruses in the Hantavirus genus of the family Bunyaviridae. We expressed the entire coding region of the small (S) genome segments of three serologically distinct hantaviruses as soluble proteins in Escherichia coli and evaluated the expressed nucleocapsid proteins (NPs) as antigens for diagnosis of HFRS. We also prepared novel diagnostic antigens by expressing truncated genes from which we deleted amino acid coding regions that were highly conserved among the three viruses. These antigens were analysed for their potential to detect and differentiate between antisera to various hantaviruses by ELISA. ELISA results obtained with HFRS patient sera or with sera from naturally or experimentally infected animals indicate that homologous antigens and antisera reacted to high titre. The truncated NPs were more specific than the complete NPs in distinguishing between possible aetiological agents of HFRS. Our findings demonstrate that prokaryotic expression of portions of the NPs of specific hantaviruses can be used to generate, readily and efficiently, large quantities of antigen that is both sensitive and specific in diagnostic assays for HFRS.

Animals↗
PubMed1993

Iontophoresis of drugs in the bladder wall: equipment and preliminary studies.

Iontophoresis is the active transport of ions into tissues by means of an electric current: Ji = -D(i)delta Ci/delta chi + DizeECi/kT. Where Ji is the total ionic flux, D(i) the diffusion coefficient, Ci the concentration, z the valency, and E the electric field. The first expression on the right side of the equation is Fick's law of diffusion and approaches zero for bladder mucosa, which leads to uncertain results following intravesical administration of various therapeutic agents. The application of an electric field will potentially accelerate drug administration into the bladder wall in a controllable manner. To evaluate this concept, an appropriate source of electric current and electrodes was fabricated; then, studies were conducted in human cadaveric bladders and clinical trials in human subjects. Ionized dyes were applied in duplicate to 10 fresh cadaveric bladders. Electric currents (3.5-5.0 mA) were applied for 20 min to 10 solutions, and no current was used in 10 controls. Twenty-eight patients had 100 ml solutions of 1% mepivacaine or lidocaine with epinephrine infused into their bladders prior to endoscopic resections. Twenty-two patients received currents of 10-20 mA for 10-20 min, and 6 controls had either no drugs or a current of reverse polarity applied. Visually and on microscopy, the 10 control cadaveric bladder surfaces demonstrated only faint staining of the surface mucosa whereas the experimental surfaces showed full-thickness staining of the mucosa extending into the muscularis. The 6 control patients required supplemental anesthesia or abandonment of the operative procedure. Of the 22 experimental subjects, 16 tolerated procedures with up to 25 g of tissue removed by diathermic resection.

Administration, Intravesical↗
PubMed1993

Hormonal status and clinical relevance of hirsutism in elderly women.

Hirsutism is a common condition of elderly women, but its aethiopathogeny and its clinical implications remain unclear. We therefore studied circulating androgen concentrations in elderly women. In addition, this study aims to define a possible relationship between hirsutism and anthropometric determinations, bone mass and serum lipids. Androgen levels were determined at basal state, after adrenocorticotrophin (ACTH) stimulation and after dexamethasone administration in 10 hirsute elderly women and compared to 10 age-matched non-hirsute women. Anthropometric determinations included measurements of skinfold thickness and body mass index. Spinal bone mass density was assessed using dual photon absorptiometry. Hirsute women presented significantly higher levels of testosterone than controls (1.49 +/- 0.38 vs 0.59 +/- 0.05 nmol/l, mean +/- SEM; p < 0.05) and dihydrotestosterone (0.54 +/- 0.07 vs 0.32 +/- 0.03; p < 0.02). 17-hydroxyprogesterone levels after ACTH stimulation tended to be higher in hirsute women than in controls. No differences were observed between the two groups in serum oestrogen concentrations, plasma lipid pattern or bone mineral density. Hirsute women had a lower body mass index and lower calculated percentage body fat than the control group. We conclude that: (i) hirsutism of elderly women is associated with increased androgen levels, probably from adrenal origin; (ii) in some cases, enhanced response in 17-hydroxyprogesterone after ACTH stimulation suggests a partial adrenal 21-hydroxylase deficiency; (iii) hirsute women present anthropometric characteristics compatible with the known anabolic effect of androgens on fat-free mass.

Adrenocorticotropic Hormone↗
PubMed1993

Prevalence of specific thrombotic accidents in patients with thrombocytosis.

The prevalence of specific thrombotic accidents recognized in 260 patients with thrombocytosis are reported. Ninety one were affected by PV, 86 by ET, 20 by MF and 63 by ST. The highest incidence of thrombosis was in the PV group. About half of ET and MF patients experienced a thrombosis. In all the patients thrombosis preferentially affected the cerebrovascular district (17.3% of the cases). Coronary artery disease occurred in PV while peripheral vascular disease was frequent in ET. Portal vein district thrombosis is not rare during the course of all MPD (7.1%). Apparently, deep vein thrombosis occurs in all patients with both primary and secondary thrombocytosis.

Adult↗
PubMed1992

Thanatophoric dysplasia in monozygotic twins discordant for cloverleaf skull: prenatal diagnosis, clinical and pathological findings.

We present male monozygotic twins with thanatophoric dysplasia (TD) type I concordant for long bone abnormalities and discordant for cloverleaf skull. The twins were the product of the second pregnancy of unrelated parents, with advanced paternal age. Prenatal diagnosis and postmortem examination showed severe rhizomelic shortness of limbs, bowing of the long bones with "telephone-receiver" femora in both twins, and cloverleaf skull and hydrocephalus in one of them. It is now accepted that most of cases of TD, such as in the present report, represent an autosomal dominant mutation with a high new mutations rate.

Adult↗
PubMed1992

Antidepressant-like effect of neurotensin administered in the ventral tegmental area in the forced swimming test.

Locomotor activity and behaviour in the forced swimming test were examined in rats which had received neurotensin (0.5-5.0 micrograms) in the ventral tegmental area. Doses of 5 micrograms neurotensin but not lower increased the locomotor activity for at least 2 h. At 0.5 and 1.0 microgram neurotensin significantly increased the time the animals spent in struggling with no changes in general motor activity (swimming). The effect of 1.0 microgram neurotensin on struggling was completely antagonized by 0.5 microgram (-)-sulpiride administered in the posterior nucleus accumbens. The results suggest that activation of the mesolimbic dopamine system through administration of neurotensin in the ventral tegmental area produces antidepressant-like effects. The significance of these findings for a role of endogenous neurotensin in depression remains to be clarified.

Analysis of Variance↗
PubMed1992

The role of serotonin and dopamine in brain in the antidepressant-like effect of clonidine in the forced swimming test.

The effect of clonidine (0.1 mg/kg, i.p.), as a three-injection course, on behaviour in the forced swimming test was studied in rats injected intracerebroventricularly (i.c.v.) with 150 micrograms 5,7-dihydroxy-tryptamine (5,7-DHT) to destroy serotonin (5-HT) neurones or treated with 100 mg/kg (i.p.) (+/-)-sulpiride or 0.5 micrograms/0.5 microliter (-)-sulpiride in the nucleus accumbens. Clonidine significantly increased struggling and reduced floating and the effects were antagonized by both treatments with sulpiride but not by 5,7-DHT which markedly depleted 5-HT in brain. The results suggest that the mesolimbic dopaminergic system but not 5-HT neurones, plays a permissive role in the antidepressant-like effect of clonidine in the forced swimming test.

5,7-Dihydroxytryptamine↗
PubMed1992

Urban air pollution: use of different mutagenicity assays to evaluate environmental genetic hazard.

The genotoxic activities associated with airborne particulate matter collected in Parma (northern Italy) have been determined. The airborne particle extracts were tested for mutagenicity using Salmonella frameshift (TA98) and base-substitution (TA100) tester strains with and without S9 microsomal activation and Saccharomyces cerevisiae strain D7 in order to determine the frequency of mitotic gene conversion and ilv1-92 mutant reversion in cells harvested at stationary and logarithmic growth phase. The relationship between mitochondrial DNA mutations and ageing, degenerative diseases and cancer prompted us to take into account the mitochondrial informational target, i.e., the respiratory-deficient (RD) mutants. The results obtained show a variability in the response for the different test systems during different months. The Salmonella mutagenicity trend was directly correlated with carbon monoxide, nitrogen oxides (NOx) and Pb concentration in airborne particulates and inversely correlated with temperature, whereas the mitochondrial genotoxic effect was higher during spring and late summer. These data suggest that the genotoxic risk assessment is a time-dependent value strictly correlated with the evaluation system being tested.

Air Pollutants↗
PubMed1992

Haemorrhagic disease of lagomorphs: evidence for a calicivirus.

Studies on the aetiological agents of rabbit haemorrhagic disease (RHD) and European brown hare syndrome show that the viruses responsible for these infections can be placed in the family Caliciviridae. Established members of this group are vesicular exanthema virus (prototype), San Miguel sea lion virus and feline calcivirus. The human hepatitis E virus and the Norwalk agent may soon be included. The RHD virus genome consists of a positive stranded RNA molecule composed of 7437 nucleotides. A major subgenomic RNA of 2.2 kb, colinear with the 3' end of the genomic RNA, can also be recovered from infected liver tissue, and both RNAs are enclosed within viral capsids formed by a single major protein of approximately 60 kDa. Electron microscopic examination of organ suspensions from diseased animals shows two types of particle; 35-40 nm complete virions have the regularly arranged cup-shaped depressions typical of calcivirus morphology, and 23-25 nm smooth particles resulting from degradation of the outer surface structures of the complete virions.

Animals↗
PubMed1992

Late reoperations after repair of tetralogy of Fallot.

Twenty-two patients underwent 23 late reoperations after total correction of tetralogy of Fallot from 1965 to 1990. Indications for reoperation included: isolated ventricular septal defect (VSD) in 9 patients (41%), isolated right ventricular outflow tract (RVOT) obstruction in 3 patients (13.7%), VSD associated with a RVOT obstruction in 7 patients (31.8%), aneurysm of the pericardial RVOT patch in 1 patient (4.5%), aortic insufficiency with a residual VSD in 1 patient (4.5%), and tricuspid regurgitation in 1 patient (4.5%). The reoperation consisted of closure of a residual VSD in 17 patients, relief of a RVOT gradient in 11, insertion of a RVOT valve in 4, tricuspid valve replacement in 1 (reoperated twice), aortic valve replacement in 1, and excision of a RVOT aneurysm in 1. Two patients died in hospital (9%) but there were no early deaths in the 11 patients reoperated upon after 1978. Mean follow-up period was 135 months. There were 2 late deaths. The actuarial 20-year survival was 87%. Of the surviving patients, 16 (89%) were in New York Heart Association class I, 1 (5.5%) was in class II, and one (5.5%) was in class III. One patient required a second reoperation for tricuspid bioprosthesis degeneration and 1 patient had moderate recurrent RVOT gradient due to calcified pulmonary bioprosthesis. This study tends to support the policy of recommending reoperation in the presence of surgically significant residual defects. Reoperation is associated with a low early mortality and good long-term results.

Adolescent↗
PubMed1992

Radiation therapy and conservative surgery for soft tissue sarcomas of the extremities, torso and head and neck.

Between May 1985 and July 1990, 45 patients (pts.) with primary (39) or recurrent (6) soft tissue sarcomas of the extremities (82%), torso (11%) and head and neck (7%) were treated with radiation therapy and conservative surgery. Seven pts. not amenable to conservative surgery underwent preoperative radiation therapy whereas 38 pts. underwent local excision and post-operative radiation therapy. Out of the 38 pts. managed by postoperative radiation, 24 (63%) showed negative surgical margins and 14 (37%) positive margins, their tumor being adjacent to vital structures. Preoperative radiation allowed conservative surgery in all 7 pts. with initially inoperable tumor; surgical margins were negative in 5 and positive in 2 pts. Twenty-six pts. (58%) had tumor greater than or equal to 5 cm (5-24) and 19 (42%) less than 5 cm (2.5-4.5) in diameter. High grade tumors (G2-G3) were reported in 41 pts. (90%). In pts. treated postoperatively the radiation dose was 64-66 Gy/32-33 fractions and the pts. treated preoperatively received a dose of 50 Gy/25 fractions. Median follow-up was 33 months and all pts. had a minimum follow-up of 12 months (12-72). Three pts. (6.5%) had local failure and 9 (20%) developed distant metastases with local tumor control. All distant metastases occurred in AJC stage IIIB, 9/18 (50%), with an increased frequency by tumor size. Overall local control and disease free survival rates at 5 years (product-limit method) were 93% and 73%, respectively. An evident decrease in disease-free survival rate (33%) was noted for stage IIIB pts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

A new fluorocarbon for keratoprosthesis.

Previous studies have demonstrated the potential use of microporous, biocompatible materials to improve the long-term stability of keratoprosthesis. To determine the factors that will influence corneal tissue ingrowth into biocompatible, microporous materials, we have compared three types of fluorocarbon polymers--Impra, Gore-Tex, and Proplast--after intrastromal implantation in rabbit corneas. Despite similar physicochemical structures, a great difference was observed in histologic and ultrastructural cross sections after 4- and 8-month follow-ups. For Gore-Tex, we observed extrusion of the implant and infiltration of necrotic and inflammatory cells. All implants of Proplast also led to significant corneal damage resulting in extrusion of the material. Through the use of electron and light microscopy and image analysis, this study demonstrates the presence of cell differentiation and collagen synthesis in the pores of the Impra implant. Apart from biocompatibility, this experiment demonstrates the influence of pore size, porous microorganization, and biomechanical factors on prosthetic corneal material. Only Impra offers satisfactory interface, allowing fibroblastic cells and neocollagen synthesis into its pores, and it can become transparent.

Animals↗
PubMed1992

Repetitive sequences cloned from Leptospira interrogans serovar hardjo genotype hardjoprajitno and their application to serovar identification.

We selected, from a genomic library of Leptospira interrogans serovar hardjo genotype hardjoprajitno, two probes containing repetitive sequences (pL1 and pL590). The hybridization patterns of these probes to DNA isolated from a variety of Leptospira serovars were examined and their ability to detect subtle differences at the genomic organization level was established. We identified the DNA fragments within pL1 and pL590 which are sufficient to yield polymorphic hybridization patterns; these results define the upper size limit of two novel repetitive elements in the Leptospira genome. The pattern and degree of hybridization observed for the serovars tested in this work were used to divide Leptospira spp. into groups which share genetic relatedness; our conclusions are consistent with previous classifications by other authors.

Blotting, Southern↗