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Biomedical subjects

R Bianchi

Publications and source records attributed to R Bianchi.

At least 271 records · Page 15Linked to original sources
PubMed1982

Serum thyroid hormone concentrations and recovery of TSH secretion after excision of autonomously functioning thyroid nodules.

Serum concentrations of TSH, TT4, TT3 and rT3 were monitored for one month after excision of ten autonomous thyroid adenomas which had suppressed TSH secretion. Basal serum TSH levels start to increase between 30 hr and 20 days after surgery reaching normal and steady levels by the 24 day. Serum TT3 concentrations rapidly decrease in the first 20 hr to values near the lower limit of the normal range. Thereafter TT3 levels change little until pituitary TSH secretion recovers. Serum TT4 levels also fall, but much more slowly than TT3. Rising TSH levels stimulate residual extranodular thyroid tissue secretion of both TT3 and TT4. However, serum TT3 levels rise more rapidly than TT4 levels. Preoperative serum concentrations of both TT4 and TT3 are related directly to the time required until the beginning of the postoperative rise in TSH levels, and inversely with the maximal postoperative serum TSH concentration achieved. Throughout the study period, for all patients, serum TSH concentrations were inversely related to serum TT4 concentrations. These data suggest that, although the time required until the onset of recovery of TSH secretion is directly related to preoperative levels of TT4 and TT3, the regulation of postoperative TSH levels is dependent upon serum TT4 levels. Also, the serum TT3 levels constant at the lower limit of the normal range before recovery of TSH secretion, and the preferential rise in serum TT3 concentrations associated with rising TSH secretion, may prevent or abbreviate temporary postoperative hypothyroidism.

Adenoma↗
PubMed1982

Intracerebral adoptive immunotherapy of a murine lymphoma antigenically altered by drug treatment in vivo.

Intracerebral tumor neutralization assay and adoptive immunotherapy with in vivo sensitized lymphocytes were done in immunodepressed mice challenged intracerebrally with L5178Y/DTIC lymphoma, a tumor subline antigenically altered by treatment with 5-(3,3-dimethyl-1-triazenyl)-1H-imidazole-4-carboxamide (DTIC) in vivo. Primary cytotoxic T-lymphocytes (CTL) were generated in vitro against L5178Y/DTIC cells with the use of splenocytes of histocompatible (BALB/cCr X DBA/2Cr)F1 donors. The extent of antitumor activity of CTL was evaluated by the measurement of tumor cell proliferation in the brain, as judged by the 125I-labeled 2'-deoxyuridine uptake values and by survival times of recipient mice. The results of the experiments showed: a) CTL were highly effective in inhibiting tumor growth when they were injected along with L5178Y/DTIC tumor cells in a Winn-type neutralization assay; b) the tumor inhibition mediated by CTL was specific, since no antilymphoma effects were detected when CTL sensitized against L5178Y/DTIC line were admixed with the parental L5178Y tumor or with other unrelated lymphoma cells; and c) local adoptive immunotherapy with CTL given on day 1, 3, or 5 after the intracerebral challenge with L5178Y/DTIC lymphoma substantially impaired tumor cell proliferation and significantly increased survival times of recipient leukemic mice.

Animals↗
PubMed1980

Labeled metabolites appearing in human serum after 125I-triiodothyronine (T3) administration: a quantitative reappraisal.

The appearance in human serum of labeled iodothyronines arising from 3,5,3'-triiodothyronine (T3) catabolism was measured after bolus administration of 125I-T3. The use of column chromatography made it possible to separate in the plasma samples iodoproteins, iodide, T3 and a fourth peak ("pre-T3") eluting just before T3. The radioactivity associated with this pre-T3 peak was found to be 0.5% of T3 activity 30 min after injection, and reached a plateau value of 5.6% +/- 1.2 (mean +/- SD) from the 10th hr onward. From these data, we calculated that a maximal 5% underestimation in T3 metabolic clearance rate is inherent in those analytical methods that do not completely separate pre-T3 from T3 radioactivity. The MCR of 3,3'-diiodothyronine (T2) was also measured from the plasma disappearance curve after single injection of 125I-3,3'-T2. From these data and the mean disappearance curve of T3, the appearance curve of 3,3'-T2 in plasma was reconstructed by convolution under the assumption of a 100% conversion of T3 to 3,3'-T2. A plateau value of 4.6% of T3 activity was computed, very comparable to the experimentally determined 5.6%. This suggest that, if labeled 3,3'-T2 is the main component of the pre-T3 peak, the conversion into 3,3'-T2 represents a major pathway of T3 metabolism in man.

Chromatography, Gel↗
PubMed1980

Coagulation factor XIII in patients with acute and chronic renal disease.

The behavior of coagulation factor XIII (fibrin-stabilizing factor, FSF) was studied in patients with renal disease. Specific antiserum against the active subunit (FSFA) was employed to set up a method for the direct measurement of the active fraction in plasma, according to the electroimmunodiffusion technique. The plasma FSFA levels were measured in the following patients: (I) 31 patients with chronic renal disease and serum creatinine not higher than 1.5 mg/dl; (II) 41 patients with chronic renal failure on conservative therapy; (III) 53 uremic patients on maintenance hemodialysis; (IV) 10 patients with acute renal failure. FSFA concentration (93.3 +/- 17.6% of a reference plasma in a group of 15 healthy controls) was found to be significantly higher than normal in the patients with chronic renal disease and serum creatinine lower than 1.5 mg/dl (127 +/- 39.8%, p less than 0.005). The FSFA levels were similarly increased in the 41 patients with chronic renal failure on conservative management (134.9 +/- 35.8%, p less than 0.001), and in the 53 end-stage uremics on maintenance hemodialysis (132.8 +/- 29.5%, p less than 0.001). Whereas, FSFA concentration was found to be markedly reduced in the 10 patients with acute renal failure (35.8 +/- 14.6%, p less than 0.001). In the patients with chronic renal disease (groups I, II, and III) plasmatic FSFA higher in those patients with serum triglycerides above the upper normal limit, and a significant positive correlation was found between serum triglycerides and FSFA plasma levels.

Acute Kidney Injury↗
PubMed1979

[Transfer in vivo of cytotoxic immune lymphocytes obtained in vitro in primary culture against a murine lymphoma antigenically altered by DTIC].

Specific cytotoxic T cells were obtained by coculturing "in vitro" normal spleen cells with inactivated histocompatible DTIC-altered lymphoma cells. The "in vivo" antitumor activity of such sensitized lymphocytes was evaluated by injecting a mixture of lymphocytes + tumor into the brains of lethally irradiated syngenic mice. The results indicated that such lymphocytes demonstrate antitumor activity against the same tumor but not against unrelated tumors.

Animals↗
PubMed1979

[Experimental models of immunochemotherapeutic synergism: study of the influence of the treatment schedule].

Graded doses of LSTPA or L1210 leukemia cells were injected ip or iv into fully compatible hosts or mice incompatible for Multiple Minor Histocompatibility Loci (MMHL). Three days later the animals were treated with single doses of BCNU, NM, DTIC and VCR. The results showed that NM and VCR could synergize with the weak anti-tumor immune responses of MMHL-histocompatible mice only upon ip injection of the tumor. If the same tumor has been injected iv, only BCNU could synergize with the host's antitumor response. On DTIC treatment, no synergistic effects were detectable for either route of tumor's challenge.

Animals↗
PubMed1979

Esterase activity of rat muscle.

The esterasic capacity of a series of skeletal muscles in response to three hemisuccinate ester drugs was investigated in rats and compared to that on alpha-naphthylacetate as a reference esterase substrate. Marked variations between different muscles and between given muscles of animals of different sex were observed, indicative of a complex heterogeneity in muscular expression of esterase activity.

Animals↗
PubMed1979

Triiodothyronine turnover studies in euthyroid patients with autonomous thyroid nodules.

Triiodothyronine (T3) kinetic studies were carried out using 126I-T3 and the single injection technique in eight clinically euthyroid patients with autonomous thyroid nodules and the metabolic results were compared to those obtained in a group of 12 healthy control subjects. Plasma labeled T3 concentration was measured by a chromatographic method based on the extraction of the hormone on Sephadex G-25 columns, followed by its elution with a specific anti-T3 antiserum. The analysis of the experimental plasma disappearance curves of the labeled hormone was performed using the noncompartmental method. The results obtained showed a significantly increased metabolic clearance rate of T3 in the patients with autonomous thyroid nodules, as compared to the control group. On the average, the T3 production rates were increased more significantly than the corresponding circulating levels of the hormone, therefore, suggesting that the significant TSH inhibition observed in the euthyroid patients with autonomous thyroid nodules could be related with an increased peripheral utilization of triiodothyronine.

Adolescent↗
PubMed1979

Effect of endogenous thyroid stimulating hormone levels on the secretion of thyroid hormones in man.

The effect of endogenous thyroid stimulating hormone (TSH) on the thyroid secretion of triiodothyronine (T3) and thyroxine (T4) was evaluated by serial determinations of serum T3. T4 and TSH concentrations in the following groups of patients: a) three patients submitted to surgical removal of a solitary, autonomous thyroid nodule which had completely inhibited the extranodular tissue; b) five subjects, with the same disease, in whom functional recovery of the extranodular tissue was induced by increased circulating TSH levels, produced by treatment with methimazole; c) one patient submitted to hemithyroidectomy for multinodular goitre; d) two hyperthyroid patients who had been treated with methimazole. In all these patients serum T3 and T4 levels progressively decreased, with a consequent progressive increase in serum TSH concentrations, leading to stimulation of the thyroid gland. During this TSH-induced stimulation of thyroid tissue, a significant positive correlation was found between the serum TSH concentrations and the corresponding ratio between the serum levels of T3 and T4 (T3/T4), both within each patient group (P less than 0.001) and among all patients (P less than 0.001). The same correlation also governs the relationship between the TSH and the T3/T4 values of 34 euthyroid control subjects and one patient with incipient hypothyroidism. These data strongly suggest that endogenous TSH can induce a preferential secretion of T3 over T4 by the human thyroid.

Goiter↗
PubMed1979

Evaluation of new membranes for hemodialysis: preliminary studies with a polycarbonate membrane.

A synthetic polycarbonate (PC) membrane supplied by C.R. Bard Inc. was assessed as to its clinical usefulness and suitability to regular use with artificial kidney. The permeability of the PC membrane to 11 solutes of increasing molecular volumes (Na+, Ca++, K+, Cl-, HPO4-, urea, creatinine, uric acid, glucose, BSP, cyanocobalamine) was measured in vitro by rotating dialysis cells, as compared to that of Cuprophan PT 150. The evaluation of the PC membrane in vivo was carried out during a regular hemodialytic treatment in 5 patients using a Kiil dialyzer. The dialysance of 6 solutes (HPO4-, urea, creatinine, uric acid, hypaque, cyanocobalamine) across the PC membrane was measured at 200 ml/min blood flow rate. Both in vitro and in vivo the PC membrane showed permeability and dialysance coefficients to small molecules approximately the same than standard PT 150; the ultrafiltration rate of the PC membrane was also superimposable to that of PT 150. On the contrary, larger molecules were removed much more efficiently by the polycarbonate membrane than by PT 150. These data suggest that the membrane evaluated in this study possesses some peculiar features which could possibly result in an improvement of the quality of regular hemodialysis.

Animals↗