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Biomedical subjects

F Monaco

Publications and source records attributed to F Monaco.

At least 37 records · Page 2Linked to original sources

[Changes in the ratio of T-lymphocyte subpopulations in various cytological samples of Plummer's thyroid adenoma].

UNLABELLED: In order to correlate possible alterations of cell-mediated immune response with the evolutive phases of Plummer Adenoma (P. A.), T lymphocytes subpopulations in FNA samples and in peripheral blood lymphocytes (PBL) have been studied in 5 patients with autonomous nodules. The lymphocyte component in FNA and peripheral blood has been isolated by Lymphoprep gradient centrifugation; the analysis of T helper and T suppressor subpopulations was made by indirect immunofluorescence with OKT8 and OKT4 monoclonal antibodies. Our results show a reduction in OKT4/OKT8 ratio in cytological samples compared with PBL in patients with P. A., while in control subjects there was not statistically significant difference. In the patients with P. A., the relative increase of OKT8 lymphocytes in FNA compared with PBL is correlated with the functional state, that is toxic adenomas have a lower OKT4/OKT8 ratio compared with nodules in pre-toxic phase. IN CONCLUSION: T lymphocyte subpopulations typing in FNA demonstrate that, even in this type of hyperthyroidism, immune response disorders are present and consist of relative increase of suppressor/cytotoxic T cells, compared to T helper cells.

Adenoma

[Effects of enzymatic deglycosylation of human goiter thyroglobulin on its immunochemical properties].

Thyroglobulin (Tg), isolated from soluble iodoproteins by ammonium sulphate fractionation, was enzymatically deglycosylated in vitro and analyzed by polyacrylamide gel electrophoresis, double immunodiffusion and non-commercial RIA. Carbohydrate and iodine content was chemically determined. By PAAGE deglycosylated Tg (dTg) showed the appearance of a major band in the 12S region and three slower migrating bands corresponding to higher aggregates than 19S Tg. In immunodiffusion by testing native and deglycosylated Tg against anti-native Tg antiserum it was shown the appearance of a spur of native on deglycosylated Tg. By RIA of native and deglycosylated Tg against anti-deglycosylated Tg antiserum it was shown a minor binding capacity of the anti-deglycosylated antibody against native Tg at high dilutions. The results demonstrate that the enzymatic deglycosylation release almost all the carbohydrates of goiter Tg and that the removal of the carbohydrates of Tg produces a loss of antigenic determinants of the molecule.

Electrophoresis, Polyacrylamide Gel

[Polymorphism of human thyroxine binding serum globulin (TBG); existence of a new form of serum protein without detectable triiodothyronine binding power].

Two kinds of TBG polymorphism are described in human, one found in deglycosylated TBG from individual blood donors, the other is a genetically determined polymorphism. TBG from plasma samples from a patient with toxic goiter, not autoimmune, (p)TBG, from the patient's mother (m)TBG and from individual donors (n)TBG, were labeled with [125I]T4 or [125I]T3 and submitted to isoelectric focusing (IEF), followed by autoradiography. Three faint [125I]T4 radiolabeled bands were detectable in (p)TBG while four strong [125I]T4 radiolabeled bands were detectable in (m)TBG and (n)TBG), respectively. IEF of the [125I]T3 incubated serum samples resulted in no detectable isoelectric radiolabeled band for (p)TBG while a normal pattern was found in (m)TBG and in (n)TBG, respectively. These data suggest a new intraindividual not linked to sexual chromosome X polymorphism characterized by a loss in hormone binding.

Adult

Cardiac side effects of phenytoin and carbamazepine. A dose-related phenomenon?

Three patients with dystrophia myotonica and echocardiographic signs of subclinical cardiopathy had cardiac side effects during oral treatment with phenytoin sodium or carbamazepine. These side effects were dose related: ventricular tachycardia appeared at a toxic serum phenytoin level in one patient and disappeared as the concentration fell within the therapeutic range, and atrioventricular block grade 1 developed in two patients at low serum carbamazepine levels, its severity increasing with the drug level. Given the risk of dangerous side effects, cardiac status needs to be carefully assessed before administration of phenytoin or carbamazepine in the treatment of dystrophia myotonica.

Adult

Human undifferentiated thyroid carcinoma synthesizes and secretes 19S thyroglobulin.

Thyroglobulin (Tg) biosynthesis and secretion have been studied in one case of undifferentiated small spindle cell human thyroid carcinoma. From tumor tissue were extracted 32 mg of soluble proteins per gram of wet tissue, compared with 54 mg from control gland; after ammonium sulfate fractionation, density gradient centrifugation, and immunoprecipitation, 1.3 mg of Tg per gram of wet tissue, compared with 31.2 mg from control, were purified. By incubating in vitro up to 3 hours tumor slices with tritiated leucine, galactose, and 125I, the rate of incorporation of leucine and galactose increased with time in tumor tissue. However 125I incorporation into soluble proteins from tumor, at 3 hours of incubation, was only 1.7% of control value. By density gradient centrifugation of labeled soluble proteins a well-separated component sedimenting in the 19S peak was identified. No radioiodine was detected in the 19S fraction which showed the immunoreactive properties of 19S and was poor in 127I and sialic acid. In the incubation medium of tumor were secreted 0.4 mg of 19S Tg per gram of wet tissue compared with 48 mg of tissue in the control gland. Thus the undifferentiated thyroid carcinoma synthesizes a protein with the physiochemical and immunologic properties of 19S Tg. The undifferentiation of thyroid cells does not affect the biochemical steps involved in the synthesis of Tg.

Aged

A longitudinal study of valproate free fraction in the specific age group at greatest risk for febrile convulsions (children below 3 years).

The behavior of the free fraction of valproic acid (VPA) was evaluated during long-term treatment of 24 children (9-18 months of age) with febrile convulsions. A series of relevant hematological parameters was monitored for the entire observation period (12 months). VPA plasma levels ranged from 54.3 +/- 26 to 66.6 +/- 32.8 micrograms/ml. The unbound fraction of the drug was determined in tears, which has been shown to be the best practical indicator of the free portion of an anticonvulsant drug, and ranged from 5.1 +/- 4.0 to 6.1 +/- 4.3 micrograms/ml. The tear/plasma ratio (and hence the free/total ratio) ranged from 9.3 to 9.7, in agreement with literature data. No significant variations of VPA plasma and tear levels, and therefore of the tear/plasma ratios, were ever observed. The hematological data revealed no significant alterations during the entire observation time, although some of the variables did fluctuate. Side effects were mild and temporary. The present report indicates that VPA has no particular toxic effect in young children treated for the prevention of febrile convulsions.

Female

Transitory subclinical and permanent hypothyroidism in the course of subacute thyroiditis (de Quervain).

Sixty-two patients affected with subacute thyroiditis (SAT) were followed for a mean period of 14 months (range 1-40), by monitoring thyroid hormone levels in basal condition, pituitary TSH reserve, antithyroglobulin (TgAb) and antimicrosomal antibodies ( MsAb ), in order to study the natural course of the disease and to characterize its intermediate phase. In the first phase the mean serum iodothyronine levels were within normal limits, nevertheless elevated T3 and T4 levels were detected in 34 (54%) and 20 (32%) patients, respectively. The next phase was characterized by normal serum iodothyronine levels; TRH stimulation test, however, showed a significant increase of pituitary TSH reserve in 35 (56%) patients. All parameters reverted gradually towards normal in all but 3 patients, who showed overt permanent hypothyroidism. TgAb and MsAb were positive in the early stage in 15 (24%) and 40 (64%) patients, respectively, disappearing at the end of the follow-up period in all but one patient; this particular patient belonged to the group of 3 patients affected with permanent hypothyroidism. Our data indicate that the onset of SAT is characterized by transient hyperthyroidism and that transient subclinical hypothyroidism characterizes the next phase. TRH stimulation test is required for the diagnosis of the latter and for the identification of the few who develop permanent hypothyroidism.

Adolescent

Brain atrophy, peripheral neuropathy and folic acid deficiency.

A woman with peripheral neuropathy and cerebral atrophy, both secondary to a selective folic acid deficiency caused by severe gastrointestinal disturbances, was given folic acid replacement therapy, which improved her clinical, blood and neurophysiological status.

Atrophy

The penetration of phenobarbital in generalized and focal penicillin-induced epileptic brain of the cat.

The penetration of phenobarbital (PB) into cerebral tissue was determined in cats rendered epileptic by parenteral penicillin and in cats with focal penicillin-induced epilepsy. The results were compared with those from normal controls. In both kinds of experimental models of epilepsy, PB penetration was impaired, although a gradual and progressive accumulation of the drug in the brain tissue was observed in all three groups of cats (binding occurring from time 30 min on). Similar to the events with other substances, such as carbamazepine, the prolonged epileptic activity may have contributed to the impaired penetration of PB, because of severe metabolic alterations secondary to seizures. The present data confirm previous reports indicating that epileptic seizures alter the pharmacokinetics of drugs.

Absorption

Carbamazepine versus diphenylhydantoin in the treatment of myotonia.

A double-blind controlled trial was performed on 6 patients affected with Steinert's disease in order to evaluate the efficacy of two different dosages of diphenylhydantoin (PHT, 200 and 300 mg/day) and carbamazepine (CBZ, 600 and 800 mg/day) on the myotonic afterdischarge. Both dosages of PHT and CBZ induced a significant improvement of myotonia. For PHT a trend towards decreased efficacy is pointed out at toxic or at high dosages.

Adolescent

Long-term therapy with carbamazepine: effects on nerve conduction velocity.

Peripheral nerve function was evaluated in 30 epileptic patients on chronic therapy with carbamazepine (CBZ) and 20 healthy controls. The electrophysiological data indicated a mild progressive reduction of both motor and sensory conduction velocity in the patients on long-term treatment with the drug. The impairment of nerve function paralleled the duration of therapy (i.e. 1 through 3 years). CBZ plasma levels were constantly within the therapeutic range. Folic acid levels were below normal in about 50% of the subjects. In the absence of other evidence, the hypothesis cannot be excluded that folate deficiency may have played some role in the development of the peripheral nerve dysfunction.

Carbamazepine

Calibration of a heated transcutaneous carbon dioxide electrode to reflect arterial carbon dioxide.

The CO2 measured by a heated skin surface electrode is greater than arterial CO2. In this study we (1) determined the magnitude of this difference retrospectively, (2) adjusted the calibration of the heated transcutaneous CO2 electrode to reflect this difference, and (3) tested the validity of the calibration procedure prospectively. The retrospective study consisted of 252 simultaneous arterial and transcutaneous measurements on 38 infants and children (age range, 1 day to 6 yr). A linear regression analysis showed PtcCO2 = 1.61 X PaCO2 - 0.01 mmHg, r = 0.90 (p less than 0.0001). Because the intercept was virtually zero, we subsequently changed the calibration procedure by dividing the transcutaneous electrode reading by 1.61. The prospective study consisted of 269 more simultaneous arterial and transcutaneous measurements from 57 consecutive infants and children (age range, 1 day to 18 yr) using this calibration procedure. Regression analysis showed PtcCO2 = 1.02 X PaCO2 - 2.3 mmHg, r = 0.96 (p less than 0.0001). Thus, we found that the transcutaneous CO2 electrode, using this technique, reliably predicted the arterial CO2.

Adolescent