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Biomedical subjects

P Antonini

Publications and source records attributed to P Antonini.

17 recordsLinked to original sources
PubMed1997

Characterization and radiosensitivity at high or low dose rate of four cell lines derived from human thyroid tumors.

PURPOSE: This study attempted to establish cell lines derived from human differentiated thyroid tumors, and to characterize and evaluate the radiation dose-rate effect. METHODS AND MATERIALS: Two cell lines (K1 and K2) were derived from papillary carcinomas, one (K7) from a follicular less-differentiated carcinoma and one (A14) from a follicular adenoma. Cell-survival curves after irradiation were established by the in vitro colony method. Radiation doses were delivered either at a high (45.9 Gy/h) or low dose rate (0.6 Gy/h) by a 60Co source. The data were analyzed according to the linear quadratic and multitarget model of radiation action. RESULTS: Doubling times were around 24 h. All cell lines were positive for intracellular thyroglobulin. Cyclic adenosine monophosphate (cAMP) response to thyrotropin (TSH) was significant for the cell lines derived from the follicular adenoma and follicular carcinoma. The two cell lines derived from papillary carcinomas were tumorigenic after inoculation into nude mice. After high-dose-rate irradiation, the surviving fraction at 2 Gy (SF2) was not significantly different for the three malignant cell lines K1, K2, and K7, and ranged from 0.39 to 0.42. For the adenoma cell line A14, we found a higher radiosensitivity with a lower SF2 value and a higher alpha parameter. After low-dose-rate irradiation, only one cell line (K2) showed a significant low-dose-rate sparing with a dose reduction factor of 1.35. CONCLUSION: The major result of our study is the weak effect of the dose rate on the survival of thyroid cell lines.

Adenocarcinoma, Follicular↗
PubMed1993

Cytogenetic characterization of a new human papillary thyroid carcinoma permanent cell line (GLAG-66).

A new permanent cell line (GLAG-66) has been established from the metastases of a papillary thyroid carcinoma in a male patient. Herein are reported the cytogenetic characteristics of this new cell line, which is tumorigenic in athymic mice. An aneuploid chromosomal pattern was observed (48 chromosomes) with various chromosomal abnormalities. The karyotype was: 48,XY,der(1)t(9;1;9), +der(8)t(1;8),der(9)t(1;9),der(9)t(1;9), +14. This cell line should prove to be of great value in the study of the biology of human papillary thyroid carcinomas.

Aneuploidy↗
PubMed1992

Cytogenetic studies on 19 papillary thyroid carcinomas.

Short-term cultures from 19 papillary thyroid adenocarcinomas revealed clonal numerical and/or structural chromosomal changes in 13 tumors, nonclonal abnormalities in one tumor, and only normal karyotypes in five tumors. Clonal abnormalities of chromosome 10 were present in three tumors, two of which had the translocation t(7;10)(q35;q21). Numerical abnormalities of chromosome 17 were detected in two tumors.

Adenocarcinoma, Papillary↗
PubMed1991

Cytogenetic abnormalities in thyroid adenomas.

Cytogenetic investigations using short-term cultures are reported in six thyroid adenomas. Clonal and nonclonal numerical chromosomal changes were present in two tumors. In two of the four remaining, nonclonal numerical and structural abnormalities were observed, whereas only normal karyotypes were found in the other two. Chromosome 10 and 17 were involved in several cases, although no common clonal changes could be detected. The present studies show that thyroid adenomas, benign tumors of an endocrine gland, may have chromosomal abnormalities, as described for other benign tumors.

Adenoma↗
PubMed1990

Cardiovascular regulation during angiotensin converting enzyme inhibition with captopril in diabetes-associated hypertension.

Diabetes-associated hypertension is accompanied by high levels of body sodium and cardiovascular hyper-reactivity to noradrenaline. Captopril, a promising drug for the treatment of hypertension in diabetics, may influence sodium metabolism and adrenergic pathways. This possibility was investigated in 11 patients with non-azotaemic diabetes mellitus and hypertension, studied after a 3-week placebo phase and after an 8-week phase of captopril treatment (50-100 mg/day). Blood pressure, exchangeable body sodium, blood volume, plasma renin activity, angiotensin II (Ang II), aldosterone, catecholamine levels and the pressor reactivity to infused Ang II or noradrenaline were measured. Compared with placebo, captopril caused a significant decrease in arterial pressure and stimulation of plasma renin activity. Exchangeable sodium, blood volume, plasma Ang II, aldosterone, noradrenaline and adrenaline levels, the pressor and aldosterone responsiveness to infused Ang II and the pressor response to infused noradrenaline (alone or combined with atropine) were not modified. These findings suggest that in hypertensive diabetics angiotensin converting enzyme inhibition causes a marked decrease in blood pressure. The mechanism of action is unrelated to changes in body sodium or noradrenergic-dependent pressor reactivity. In the stable phase of therapy, Ang II-dependent pathways are left unaltered when captopril is administered twice a day.

Adult↗
PubMed1990

Evaluation of the effect-duration of once-daily enalapril compared with once-daily captopril.

The extent and duration of the antihypertensive effect of enalapril and captopril, both given once daily, were evaluated in 12 mild-to-moderate essential hypertensives by 24-hour noninvasive blood pressure (BP) monitoring (Pressurometer IV-mod 1990-1991, Del Mar Avionics). Patients were randomized to a cross-over regimen either with enalapril, 10-20 mg, followed by captopril, 50-100 mg (first group), or with captopril followed by enalapril (second group). The dose was doubled if, at week 3 of each treatment, the diastolic BP remained at 90 mm Hg. Doubling of the 2 drugs was not required in 4 patients; in 7 patients the dose of both drugs was doubled; and in 1 patient the dose of only captopril was doubled. Two of the 7 patients who required doubling of both drugs were considered nonresponders to enalapril and captopril. The circadian rhythm was not altered by the treatments, and the drugs reduced BP mainly during the waking hours. However, the second peak of systolic BP in the late afternoon did not graphically appear to be modified by captopril administration. A periodic asymmetric model with 3 harmonics analysis carried out on 24-hour BP data justifies only the use of enalapril for once-daily administration.

Adult↗
PubMed1989

Isolation and structure determination of two new analogs of teicoplanin, a glycopeptide antibiotic.

Teicoplanin is an antibiotic produced by fermentation of Actinoplanes teichomyceticus as a complex formed by five closely related glycopeptides characterized by different fatty acid chains of ten and eleven carbon atoms. In addition, minor quantities of related substances are present. Two of them, named RS-1 and RS-2, were shown to be teicoplanins having as fatty acid chains 10-methylundecanoic acid and n-dodecanoic acid, respectively. Other two related substances, named RS-3 and RS-4, have now been isolated and purified starting from fermentation broths of a mutant of the same microorganism producing them in substantial amounts. This was achieved by semipreparative reversed-phase liquid chromatography carried out on high-pressure scale. The structures were assigned on the basis of 1H NMR spectra and homonuclear COSY 2D experiments and fast atom bombardment MS spectrometry, in comparison with the large mass of data till now accumulated on teicoplanin. RS-3 and RS-4 are teicoplanins having as fatty acid chains 6-methyloctanoic acid and n-nonanoic acid, respectively.

Actinomycetales↗
PubMed1988

[Unconscious insecurity before and after breast examination in senology patients without pathologic findings].

The study reported here surveyed unconscious insecurity among healthy women, who consulted a senological outpatient service because of suspected breast cancer. It was investigated whether and in what way the reduction in unconscious insecurity, after being informed that the diagnosis was favorable (no carcinoma), is dependent on certain psychological conditions. The patients were divided into various subgroups according to history and psychological criteria, and these subgroups were then compared with regard to the reduction in their feeling of insecurity after being advised that there were no pathological findings. The individual tendency to tenseness (Brauchli 1983, 1987 a, b) was used as an indicator of unconscious insecurity. Coming to terms consciously with the cancer risk and possible consequences of cancer, proved to be a prerequisite for an adequate reduction in unconscious insecurity after being informed that findings were negative.

Adaptation, Psychological↗
PubMed1987

Systemic and renal hemodynamic changes after two-month treatment with enalapril in patients with essential hypertension.

Twelve essential hypertensive patients with normal renal function were treated once daily with a new angiotensin converting enzyme inhibitor, enalapril maleate, for about two months. In all patients, the drug-induced changes in blood pressure (BP), systemic and renal hemodynamics, plasma renin activity (PRA), and urine aldosterone (UA) were evaluated. Mean arterial pressure was significantly lowered. No significant changes in cardiac index, heart rate, and stroke index were observed, while peripheral vascular resistance index was significantly decreased. Plasma and blood volumes were not significantly altered. The effects on renal hemodynamics consisted of a significant increase in renal plasma flow (RPF), a decrease in renal vascular resistance, and no change in glomerular filtration rate (GFR). UA excretion was significantly reduced during enalapril therapy. The drug was well tolerated, and no side effects were observed. In summary, enalapril is able to reduce blood pressure through a vasodilatatory effect without change in cardiac output. It increases renal blood flow with no change in glomerular filtration rate.

Adolescent↗
PubMed1985

Proglumetacin in arthritis of the hip and the knee. Results of a post-marketing surveillance study.

An open, multicentre, outpatient study involving 77 Italian orthopaedic and rheumatology centres was conducted to evaluate the efficacy and tolerability of proglumetacin in the treatment of arthritis of the hip and of the knee. A total of 1522 patients each received 450 mg/day proglumetacin (150 mg tablets X 3) for a period of 4 weeks, with checks at the end of weeks 1, 2, 3 and 4. The evaluation of efficacy was carried out using the following parameters: pain, inactivity, stiffness, limitation of mobility. Pain was reduced by 62% from the beginning to the end of the study. Complete tolerability was demonstrated in 82.9% (1262 patients) of the study group; side-effects, mainly involving the gastrointestinal tract, were seen in only 17.1% of the study group (260 patients). Side-effects were reported in 2.2% of the patients; 5.3% of these were shown to result from proglumetacin treatment. It was concluded that proglumetacin, at the optimum dose of 450 mg/day, answers the need for an effective and well tolerated drug of first choice in the treatment of arthritis.

Adult↗
PubMed1980

Thiazorifamycins. III. Biosynthesis of rifamycins P, Q and verde, novel metabolites from a mutant of Nocardia mediterranea.

The thiazorifamycins are derived from rifamycin S and cysteine; rifamycins P and Verde are formed by chemical reactions, while rifamycin Q synthesis involves obligatory enzymatic assistance. All antibiotics come from a common six-member precursor lacking C-1 of cysteine; the thiazin-2-one ring of rifamycin Verde retains both C-2 and C-3 of cysteine, while the thiazole ring of rifamycins P and Q retains only C-2, C-3 becoming exocyclic in the ring-contraction C-3 is present in rifamycin Q but not in P.

Biotransformation↗