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J Simonetti

Publications and source records attributed to J Simonetti.

34 records · Page 2Linked to original sources
PubMed1991

Left ventricular diastolic collapse. An echocardiographic sign of regional cardiac tamponade.

BACKGROUND: Cardiac tamponade after cardiac surgical procedures is often associated with hemodynamically significant localized pericardial effusions. The localized collection of pericardial effusion in the postoperative period and the atypical presentation of cardiac tamponade limit the use of conventional clinical and echocardiographic signs usually seen with a circumferential pericardial effusion. Observation of left ventricular diastolic collapse in the echocardiogram of a patient with postoperative regional cardiac tamponade prompted us to explore the frequency of this sign in regional cardiac tamponade. METHODS AND RESULTS: We retrospectively analyzed the echocardiograms of 18 patients with postoperative cardiac tamponade for the following echocardiographic findings: right atrial collapse, right ventricular diastolic collapse, left atrial collapse, and left ventricular diastolic collapse. Three of the 18 patients had circumferential pericardial effusion, and 15 had loculated pericardial effusion; in 10, the effusion was predominantly posterior, and in the other five, it extended laterally or inferiorly. The conventional echocardiographic signs of cardiac tamponade such as right atrial collapse, right ventricular diastolic collapse, and left atrial collapse were present in only 3, 1, and 3 of these 15 patients, respectively, but all exhibited left ventricular diastolic collapse. Increasing pressure within the compartment of a loculated pericardial effusion reaching the limit of pericardial distensibility and consequent transient reversal of transmural left ventricular pressure during diastole are most likely the basis for diastolic collapse of the thick-walled ventricle in a setting of regional cardiac tamponade. CONCLUSIONS: We conclude that left ventricular diastolic collapse is a frequent sign of regional cardiac tamponade and could be a useful marker of tamponade in postoperative patients.

Adult↗
PubMed1990

The 11q13 amplicon of a mammary carcinoma cell line.

Fifteen to 20% of breast carcinomas show amplification of genes located at 11q13. The HST/FGFK and INT2 fibroblast growth factor (FGF)-related genes and the BCL1 locus are usually present in the amplification units. We have investigated the structure and chromosomal location of the 11q13 amplicon of the MDA-MB-134 mammary carcinoma cell line by using in situ chromosomal and pulsed field gel hybridizations. The results indicate that a limited number of amplification units are involved in the constitution of an extended chromosomal region located on 11q. These units do not show any important rearrangement over rather large distances around the HST/INT2 and BCL1 loci.

Blotting, Northern↗
PubMed1990

Human CD28 and CTLA-4 Ig superfamily genes are located on chromosome 2 at bands q33-q34.

CD28 is a cell surface molecule present on most peripheral T cells which has been implied in the amplification of the T-cell response in vitro. Using in situ hybridization on human prometaphase cells, we have found that the human CD28 gene maps to chromosome 2 at bands q33-q34, as shown previously for the CTLA-4 gene. CD28 and CTLA-4 are both members of the Ig superfamily, where they define a subgroup of membrane-bound single V domains. Their chromosomal proximity and their close structural relationship suggest that these two genes could be the result of the duplication of a common evolutionary precursor and may share some functional properties.

Antigens, CD↗
PubMed1990

Problems and pitfalls in the performance and interpretation of color Doppler flow imaging: observations based on the influences of technical and physiological factors on the color Doppler examination of mitral regurgitation.

Color Doppler flow imaging has become an integral part of the echocardiographic examination. By providing real-time, two-dimensional spatial maps of normal and abnormal cardiac blood flows, this technique provides important information that may be used to guide patient management. The acquisition and display of color Doppler flow information may be influenced by technical factors, by the physiological condition of the patient, by abnormalities of cardiac morphology, and, on occasion, by artifact. In this article, the results of a study performed to evaluate the influence of technical factors on the color Doppler assessment of mitral regurgitation are reported. Mitral regurgitation jet area size changed significantly with variation in the control settings for color gain, color process, color map, color image resolution, and sector width. A review of those factors that influence the performance and interpretation of the color Doppler flow examination is provided and their significance discussed.

Echocardiography, Doppler↗
PubMed1989

Translocation (3;21) in Philadelphia positive chronic myeloid leukemia: high resolution chromosomal analysis and immunological study on five new cases.

Translocation t(3;21)(q26;q22) is a rare but nonrandom event occurring in Philadelphia positive chronic myeloid leukemia. We describe five new cases (two males, three females) where t(3;21) is associated with the progression of the disease. Using FACS analysis, we confirm the myeloid type of the blast crisis. High resolution chromosomal analysis allowed us to define more precisely the chromosomal breakpoints to 3q26.2 and 21q22.2, close to the respective localizations of two genes important in cell proliferation and cancer pathogenesis: the transferrin receptor gene and the ets.2 proto-oncogene.

Adult↗
PubMed1988

Pericardiocentesis under two-dimensional echocardiographic guidance in loculated pericardial effusion.

Pericardiocentesis to relieve tamponade from a loculated pericardial effusion in patients following cardiac surgery is greatly aided by two-dimensional echocardiographic imaging guidance. This technique delineates the fluid distribution and the site of adhesions, defines the path for introduction of an aspiration needle, alerts to the possibility of myocardial contact, and helps in positioning the drainage catheter. Two-dimensional echocardiographic imaging can be performed at the patient's bedside, and the images are easy to interpret. This technique simplifies pericardiocentesis and helps to avoid complications.

Catheterization↗
PubMed1988

Cervical versus intrauterine insemination of ewes using fresh or frozen semen diluted with aloe vera gel.

This study was conducted at Belen de Escobar, Argentina, in March and April 1987. Experimental work on synchronization of estrus, deep-freeze conservation of ram semen and small fertility trials involving cervical and intrauterine (i.u.) insemination methods was undertaken. A total of 80 Corriedale ewes were used in seven insemination trials. Insemination trials were grouped into two experimental groups for comparison of 1) frozen semen diluted with an experimental extender and a control diluent inseminated cervically or i.u. in synchronized/superovulated ewes and 2) cervical insemination of fresh diluted or frozen semen in ewes inseminated at natural estrus or in ewes that were synchronized/superovulated. An overall ovulation rate of 8.7 +/- 0.5 was obtained by using a superovulatory regimen consisting of 3 mg Norgestomet implants and a total dose of 18 mg follicle stimulating hormone-pituitary (FSH-P). Numbers of ova recovered per ewe following superovulation ranged from 4.3 to 5.4. In experimental Group I, fertilization rates improved when laparoscopic intrauterine AI was used compared with cervical insemination (P<0.05). Fertility rates of i.u. and cervical insemination of frozen semen diluted with the experimental extender showed satisfactory fertilizing capacity. In experimental Group II, a lower number of fertilized ova were recovered from ewes inseminated with frozen semen (P<0.02), irrespective of their estrus manipulation.

Journal Article↗
PubMed1987

Phenotypic evolution of CTL B-lines in vitro.

This study demonstrates that cytolytic T-cell lines exhibit progressive in-vitro modifications of their phenotype and of their growth behaviour and may use different pathways for their multiplication. Comparing three established cell lines, we firstly demonstrated that the expression of LFA-I is stable but the Lyt 2, 3 is rapidly lost. In this case, a high lectin-dependent cytotoxicity appears. Secondly, we demonstrated that two of the cell lines used the interleukin 2-interleukin 2 receptors (IL-2-IL-2R) binding pathway. Two different monoclonal antibodies showed that the IL-2 receptors distribution does not correlate with the number of functional sites which determines the IL-2 requirement. In contrast, the third cell line, although bearing high levels of IL-2 receptors, grows without the addition of IL-2; this cell growth is not inhibited by anti-IL-2 receptors monoclonal antibodies. Thirdly, it appears that the new property of IL-2 independence is associated with acquisition of the simultaneous capacity to induce tumour grafts in nude mice. As it has been recently reported that cytolytic T-lymphocytes against tumour cells could be promising immunotherapeutic agents, the spontaneous malignant transformation of such CTL lines should be taken into account before using them for adoptive immunotherapeutic purposes.

Animals↗
PubMed1984

Some simple computational methods to improve the folding of large RNAs.

Computational methods are described which increase the efficiency of the RNA folding algorithm described by Zuker and Stiegler. Bit addressing has been used to reduce the memory requirements from 2NxN to NxN/2. The order in which the nucleotide sequence is examined internally has been altered, and some additional short arrays which carry temporary information have been introduced. These changes optimize the management of the large data arrays generated by the algorithm. The methods were developed for use with a UNIVAC 1100/82 computer. They are, however, easily adaptable to other computers; especially those with virtual memory capabilities. The analysis of sequences up to 1000 nucleotides long are relatively routine, and larger searches are also feasible. Some limitations and applications of the algorithm are also discussed.

Base Sequence↗
PubMed1984

Functional characteristics of cytotoxic T lymphocyte polyoma virus-transformed fibroblast hybrids.

By two different fusions between a cytotoxic T-lymphocyte (CTL) clone and a polyoma virus (Py)-transformed fibroblast line, 40 hybrid clones have been generated. It has been demonstrated that they were all TCGF independent for multiplication. Moreover, some of these hybrids were functional for cytolytic expression, whether or not TCGF was present either at the time of fusion or in the selective media. Two clones generated from the same fusion were markedly cytolytic and were able to remove TCGF from their culture medium, suggesting that they possessed TCGF receptors. These clones also secreted discrete amounts of a TCGF-like factor. The effect of TCGF on hybrid cell proliferation is discussed.

Animals↗
PubMed1984

Hereditary congenital goitre with thyroglobulin deficiency causing hypothyroidism.

The thyroid glands of two hypothyroid goitrous siblings aged 13 and 14 and of a 21-year-old hypothyroid goitrous female were examined. In all three patients a very high thyroid uptake of iodide was observed in the presence of a negative perchlorate discharge test. An abnormally high serum protein bound iodine (12.9-20.0 micrograms/dl) and low serum T4 concentration suggested the presence of increased serum levels of iodoalbumin. Surprisingly, serum T3 levels were normal or low normal (80-220 ng/dl) in several determinations. Basal serum TSH was elevated and an exaggerated TSH response was observed after TRH. Serum thyroglobulin was undetectable in one patient, low normal in another and in the normal range for the third one. Except for the patient with undetectable Tg the two other subjects slightly increased the serum Tg levels after a bovine TSH injection. Plasma chromatography after a tracer dose of 125I disclosed only minute amounts of T3 + T4 and MIT + DIT. Studies performed in the homogenized thyroid tissues indicated that these goitrous glands had pronounced decrease of immunoreactive thyroglobulin. The total amount of Tg-like proteins (RIA) in the thyroid soluble protein extract was only 16-122 micrograms/g (normal: 50-70 mg/g of tissue). Ultracentrifugal studies were unable to demonstrate the presence of mature (18-20S) thyroglobulin. Only one peak (3.6-4.1S) was obtained in the pooled soluble proteins supernatants. Hydrolysis of the homogenates indicated, by subsequent column chromatography, very low relative concentrations of iodotyrosines and iodothyronines and that a relatively large amount of iodide remained associated with subcellular proteins and undigested. The predominant histological pattern was of the intermediary differentiated adenoma type, microfollicular or fetal, with several atypical features and capsular invasion which may suggest malignant change. We conclude that a defective Tg export from the cell to the lumen or an anomaly in the structural gene leading to inadequate translation of Tg mRNA finally results in deficient storage of normal, mature Tg in the colloid with subsequent goitrous hypothyroidism.

Adolescent↗
PubMed1981

Chromosomes involved in production of infectious SV40 particles in mouse/SV40-transformed Chinese hamster cell hybrids.

The clone 6d hybrid, capable of expressing the virus-specific T-antigen but unable to produce infectious virus particles after superinfection, presented a complete mouse (3T3-4E) chromosome complement and a significant loss of Chinese hamster (CHK/SVLP AG) chromosomes. Similar properties were displayed by a BUdR-resistant derivative of the Cl 6d hybrid (Cl 6d.6BU). Three independent superhybrid clones (CL 10B, Cl 10C, Cl 11A) isolated after backcross of the Cl 6d.6BU hybrid with a nontransformed Chinese hamster kidney cell line (CHK/AG) were able to produce infectious SV40 virus. In spite of the loss of mouse chromosomes, there was no significant difference in the average number of chromosomes between the Cl 6d.6BU and the superhybrid clones. Thus, the Chinese hamster chromosomes seemed to compensate for the loss of the mouse chromosomes. Although the effect of Chinese hamster chromosomes cannot be totally disregarded, our data suggested a positive correlation between the inability to produce infectious SV40 and the presence of certain mouse chromosomes.

Animals↗
PubMed1979

Imparied cyclic-AMP response to thyrotrophin in congenital hypothyroidism with thyroglobulin deficiency.

A 19 year old man had congenital hypothyroidism and severely retarded development. His thyroid gland was not enlarged and laboratory findings included low serum concentration of T4 (2.8 microgram/100 ml) and T3 (16 ng/100 ml) with a high level of TSH (52 microU/ml) that rose to 192 microU/ml after TRH. 131I uptake by the thyroid was normal (41.5% at 24 h) and did not show a normal increase after exogenous TSH administration (49.5% at 24 h). The perchlorate discharge test was negative and no antibodies against thyroid antigens were found. Studies on the biopsy specimen revealed low iodide trapping by the thyroid slices and no formation of cyclic AMP after TSH was added to the medium. The endogenous TSH of the patient was biologically active increasing cyclic adenosine monophosphate c-AMP concentration in normal thyroid slices. No thyroglobulin was found in the thyroid tissue either by immunological or ultracentrifugational methods. An increased proportion of iodoalbumin was present in the serum. We postulate that the fundamental defect in this gland is an impaired generation of c-AMP by the defective thyroid cell and deficiency of thyroglobulin formation resulting in inadequate thyroxine and triiodothyronine synthesis.

Adult↗
PubMed1978

Correlation between characteristics of transformation and malignancy of intra and interspecific somatic hybrid cells.

The transformed properties of five hybrid cell lines which had either one or another parent in common were studied and compared with their tumorigenicity. Three hybrid cell lines, derived from the Chinese hamster DC-3F/ADX/Aza line, were resistant to actinomycin-D. This property seemed to be correlated with the presence of a marker chromosome from the common parent. The tumorigenicity was intermediate between those of the parent cell lines. On the other hand, agglutinability by concanavalin A (Con A) was variable. Three hybrid cell lines which had either the A9 or the clone 1D (both derived from mouse fibroblasts) showed very similar transformed characteristics, but two were tumorigenic and one not so. It appears from this study that the properties of the hybrid cell lines can be influenced more by one parent, depending on the genes retained at chromosome segregation. The limits of Con A agglutination as a characteristic of transformation and the validity of the check pouch grafts as tumorigenicity test for malignant human cell lines are discussed.

Agglutination↗