Nanofibrous antibiotic-eluting matrices: Biocompatibility studies in a rat model

This study evaluated the biocompatibility of degradable polydioxanone (PDS) electrospun drug delivery systems (hereafter referred as matrices) containing metronidazole (MET) or ciprofloxacin (CIP) after subcutaneous implantation in rats. Sixty adult male rats were randomized into six groups: SHAM (sham surgery); PDS (antibiotic-free matrix); 1MET (one 25 wt% MET matrix); 1CIP (one 25 wt% CIP matrix); 2MET (two 25 wt% MET matrices); and 2CIP (two 25 wt% CIP matrices). At 3 and 30 days, animals were assessed for inflammatory cell response (ICR), collagen fibers degradation, and oxidative profile (reactive oxygen species [ROS]; lipid peroxidation [LP]; and protein carbonyl [PC]). At 3 days, percentages of no/discrete ICR were 100, 93.3, 86.7, 76.7, 50, and 66.6 for SHAM, PDS, 1MET, 1CIP, 2MET, and 2CIP, respectively. At 30 days, percentages of no/discrete ICR were 100% for SHAM, PDS, 1MET, and 1CIP and 93.3% for 2MET and 2CIP. Between 3 and 30 days, SHAM, 1CIP, and 2CIP produced collagen, while 1MET and 2MET were unchanged. At 30 days, the collagen fiber means percentages for SHAM, PDS, 1MET, 1CIP, 2MET, and 2CIP were 63.7, 60.7, 56.6, 62.6, 51.8, and 61.7, respectively. Antibiotic-eluting matrices showed similar or better oxidative behavior when compared to PDS, except for CIP-eluting matrices, which showed higher levels of PC compared to SHAM or PDS at 30 days. Collectively, our findings indicate that antibiotic-eluting matrices may be an attractive biocompatible drug delivery system to fight periodontopathogens. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B, 2019.

Role of the adjunctive antimicrobial photodynamic therapy to periodontal treatment at plasmatic oxidative stress and vascular behavior

BACKGROUND

To evaluate for the first time in vivo the effects of methylene blue (MB) photosensitizer dissolved in ethanol in antimicrobial photodynamic therapy (aPDT) as adjuvant periodontal treatment, at plasmatic oxidative stress and vascular behavior in rat model.

METHODS

Wistar rats were divided into negative control (NC, no periodontitis) and positive control (PC, with periodontitis, without any treatment). The other groups had periodontitis and were treated with scaling and root planing (SRP); SRP+aPDT+MB dissolved in water (aPDT I); SRP+aPDT+MB dissolved in ethanol (aPDT II). The periodontitis was induced by ligature at the mandibular right first molar. At 7/15/30days, rats were euthanized, the plasma was used to determine oxidative stress parameters and gingival tissue for histomorphometric analysis.

RESULTS

PC showed higher thiobarbituric acid reactive substances levels in 7/15/30days. aPDT II was able to block the lipid peroxidation, especially between 15th and 30th days. Glutathione reduced levels were consumed in PC, aPDT I and II groups throughout the experiment. aPDT II increased the vitamin C levels which were restored in this group in the 30th day. aPDT II group showed the highest number of blood vessels.

CONCLUSION

In summary, the aPDT with MB dissolved in ethanol provides better therapeutic responses in periodontitis treatment.

Neuroprotective effects of quercetin on memory and anxiogenic-like behavior in diabetic rats: Role of ectonucleotidases and acetylcholinesterase activities

The present study investigated the protective effect of quercetin (Querc) on memory, anxiety-like behavior and impairment of ectonucleotidases and acetylcholinesterase (AChE) activities in brain of streptozotocin-induced diabetic rats (STZ-diabetes). The type 1 diabetes mellitus was induced by an intraperitoneal injection of 70mg/kg of streptozotocin (STZ), diluted in 0.1M sodium-citrate buffer (pH 4.5). Querc was dissolved in 25% ethanol and administered by gavage at the doses of 5, 25 and 50mg/kg once a day during 40days. The animals were distributed in eight groups of ten animals as follows: vehicle, Querc 5mg/kg, Querc 25mg/kg, Querc 50mg/kg, diabetes, diabetes plus Querc 5mg/kg, diabetes plus Querc 25mg/kg and diabetes plus Querc 50mg/kg. Querc was able to prevent the impairment of memory and the anxiogenic-like behavior induced by STZ-diabetes. In addition, Querc prevents the decrease in the NTPDase and increase in the adenosine deaminase (ADA) activities in SN from cerebral cortex of STZ-diabetes. STZ-diabetes increased the AChE activity in SN from cerebral cortex and hippocampus. Querc 50mg/kg was more effective to prevent the increase in AChE activity in the brain of STZ-diabetes. Querc also prevented an increase in the malondialdehyde levels in all the brain structures. In conclusion, the present findings showed that Querc could prevent the impairment of the enzymes that regulate the purinergic and cholinergic extracellular signaling and improve the memory and anxiety-like behavior induced by STZ-diabetes.

Antioxidant and anti-inflammatory effects of quercetin in functional and morphological alterations in streptozotocin-induced diabetic rats

The aim of this study was to investigate functional and morphological alterations caused by oxidative stress in streptozotocin (STZ)-induced diabetic rats and to evaluate the antioxidant effect of quercetin (QUE) in this disease. One hundred and thirty male Wistar rats, it were randomly distributed in 10 different experimental groups, with ten animals per group: Control Saline (CS), Control Ethanol (CE), Control QUE 5mg/kg (CQ5), Control QUE 25mg/kg (CQ25), Control QUE 50mg/kg (CQ50), Diabetic Saline (DS), Diabetic Ethanol (DE), Diabetic QUE 5mg/kg (DQ5), Diabetic QUE25 mg/kg (DQ25), Diabetic QUE 50mg/kg (DQ50). Therefore, hyperglycemia is directly involved in oxidative stress production, as well as in functional and morphological alterations caused by the excess of free radicals. QUE, specially at the dosage of 50mg/kg, can act as an antioxidant and anti-inflammatory agent, becoming a promising adjuvant in the treatment of diabetes mellitus.

Thyroid suppression test with a single oral dose of levothyroxine in the diagnosis of functional thyroid autonomy

OBJECTIVE

To propose a modified form of thyroid suppression test with use of a single oral dose of levothyroxine (35 mg/kg).

METHODS

After a baseline scintigram, 23 patients with nodular goiter suspected of autonomous function (warm or hot nodules, subnormal or undetectable thyrotropin levels, or both findings) and 14 normal subjects underwent a repeated scintigram 4 days after administration of levothyroxine. We evaluated triiodothyronine (T(3)), free thyroxine, and thyrotropin before and on the first, second, third, fourth, and seventh days after administration of the individualized dose of levothyroxine.

RESULTS

The 99th percentile of postsuppression uptake in normal subjects was determined, and an uptake >12.4%, a 131 I concentration restricted to the nodule, or both factors were adopted as the criteria for diagnosis of an autonomously functioning thyroid nodule. Twelve patients were considered to have autonomously functioning nodules, and 11 patients were considered to have nonautonomous nodules. Baseline thyrotropin levels in patients with autonomous nodules did not differ significantly from those in patients with nonautonomous nodules. No signs or symptoms of toxicity were detected during the test, but all study subjects had increased free thyroxine values, and seven had high levels of T(3).

CONCLUSION

The thyroid suppression test with 35 mg/kg of levothyroxine is an effective method for the diagnosis of an autonomously functioning thyroid nodule, is nontoxic, and avoids the inaccurate use of the medication occasionally observed with T(3). Even sensitive methods of thyrotropin determination cannot replace this test in the evaluation of autonomous thyroid function.

The contribution of 700,000 ORF sequence tags to the definition of the human transcriptome

Open reading frame expressed sequences tags (ORESTES) differ from conventional ESTs by providing sequence data from the central protein coding portion of transcripts. We generated a total of 696,745 ORESTES sequences from 24 human tissues and used a subset of the data that correspond to a set of 15,095 full-length mRNAs as a means of assessing the efficiency of the strategy and its potential contribution to the definition of the human transcriptome. We estimate that ORESTES sampled over 80% of all highly and moderately expressed, and between 40% and 50% of rarely expressed, human genes. In our most thoroughly sequenced tissue, the breast, the 130,000 ORESTES generated are derived from transcripts from an estimated 70% of all genes expressed in that tissue, with an equally efficient representation of both highly and poorly expressed genes. In this respect, we find that the capacity of the ORESTES strategy both for gene discovery and shotgun transcript sequence generation significantly exceeds that of conventional ESTs. The distribution of ORESTES is such that many human transcripts are now represented by a scaffold of partial sequences distributed along the length of each gene product. The experimental joining of the scaffold components, by reverse transcription-PCR, represents a direct route to transcript finishing that may represent a useful alternative to full-length cDNA cloning.

Estradiol decreases iodide uptake by rat thyroid follicular FRTL-5 cells

Estradiol has well-known indirect effects on the thyroid. A direct effect of estradiol on thyroid follicular cells, increasing cell growth and reducing the expression of the sodium-iodide symporter gene, has been recently reported. The aim of the present investigation was to study the effect of estradiol on iodide uptake by thyroid follicular cells, using FRTL-5 cells as a model. Estradiol decreased basal iodide uptake by FRTL-5 cells from control levels of 2.490 +/- 0.370 to 2.085 +/- 0.364 pmol I-/microg DNA at 1 ng/ml (P<0.02), to 1.970 +/- 0.302 pmol I-/microg DNA at 10 ng/ml (P<0.003), and to 2.038 +/- 0.389 pmol I-/microg DNA at 100 ng/ml (P<0.02). In addition, 4 ng/ml estradiol decreased iodide uptake induced by 0.02 mIU/ml thyrotropin from 8.678 +/- 0.408 to 7.312 +/- 0.506 pmol I-/microg DNA (P<0.02). A decrease in iodide uptake by thyroid cells caused by estradiol has not been described previously and may have a role in goiter pathogenesis.

Identification of human chromosome 22 transcribed sequences with ORF expressed sequence tags

Transcribed sequences in the human genome can be identified with confidence only by alignment with sequences derived from cDNAs synthesized from naturally occurring mRNAs. We constructed a set of 250,000 cDNAs that represent partial expressed gene sequences and that are biased toward the central coding regions of the resulting transcripts. They are termed ORF expressed sequence tags (ORESTES). The 250,000 ORESTES were assembled into 81,429 contigs. Of these, 1, 181 (1.45%) were found to match sequences in chromosome 22 with at least one ORESTES contig for 162 (65.6%) of the 247 known genes, for 67 (44.6%) of the 150 related genes, and for 45 of the 148 (30.4%) EST-predicted genes on this chromosome. Using a set of stringent criteria to validate our sequences, we identified a further 219 previously unannotated transcribed sequences on chromosome 22. Of these, 171 were in fact also defined by EST or full length cDNA sequences available in GenBank but not utilized in the initial annotation of the first human chromosome sequence. Thus despite representing less than 15% of all expressed human sequences in the public databases at the time of the present analysis, ORESTES sequences defined 48 transcribed sequences on chromosome 22 not defined by other sequences. All of the transcribed sequences defined by ORESTES coincided with DNA regions predicted as encoding exons by genscan. (http://genes.mit.edu/GENSCAN.html).

Detection of recurrent thyroid cancer by sensitive nested reverse transcription-polymerase chain reaction of thyroglobulin and sodium/iodide symporter messenger ribonucleic acid transcripts in peripheral blood

To investigate whether circulating thyroglobulin (Tg) messenger ribonucleic acid (mRNA) and sodium/iodide symporter (NIS) mRNA transcripts in peripheral blood are valuable in the follow-up of patients with thyroid cancer, we developed highly sensitive nested Tg and NIS mRNA detection assays and compared their accuracy with serum thyroglobulin (sTg) and whole body scan with 131I during the monitoring of 34 patients with well differentiated thyroid carcinoma who had undergone total thyroidectomy (17 of 34 also submitted to thyroid ablation with radioiodine) and were taking T4. Circulating Tg mRNA was found in 13 of 34 patients, 5 of 13 with detectable and 8 of 13 with undetectable sTg. From these 8 patients with undetectable Tg, 6 showed no cervical radioiodine uptake, and 3 presented proven metastatic disease (2 of them positive for antithyroglobulin antibodies). NIS mRNA was detected in 11 of 34 patients, but its measurement did not improve the ability to detect patients with metastases. Overall, identification of metastatic thyroid cancer was better associated with Tg mRNA than with NIS mRNA, sTg, or whole body scan (83% vs. 16.6% vs. 50% vs. 50%; P < 0.001). These data showed that circulating Tg mRNA is not only a more sensitive marker of residual thyroid tissue or thyroid cancer than sTg, particularly in patients during T4 therapy and with positive antithyroglobulin antibodies, but also was more sensitive than NIS mRNA in all patients.

Study of immunohistochemical expression of insulin-like growth factor I and proliferating cell nuclear antigen in thyroid gland papillary carcinoma and its metastasis

BACKGROUND

Several tumor factors are associated with papillary thyroid cancer. Most studies do not compare the expressions of these factors in the primary tumors and in their associated cervical metastasis.

METHODS

Paraffin sections of 20 patients with papillary carcinoma of the thyroid gland with lymph node metastasis were studied. The presence and distribution of insulin-like growth factor I (IGF-I) and proliferating cell nuclear antigen (PCNA) was analyzed, through immunohistochemical technique, in both primaries and lymph node metastasis. The results were correlated with clinical-pathologic data (sex, age, size of primary, multicentricity, thyroid capsule invasion, lymphatic and blood vessels invasion, development of distant metastasis, and associated thyroid diseases).

RESULTS

The qualitative analysis showed the reaction for IGF-I was present in more than 90% of the neoplastic cells in both primaries and lymph node metastasis. No correlation with the clinical-pathological features was observed. Regarding the PCNA, the mean percentage of nuclei stained showed no statistical difference between primaries and metastasis (p = 0.598). Except for age, clinicopathologic data had no influence on the mean percentage of nuclei stained. A correlation was verified between the percentage of cells stained by PCNA in primary tumors and the patients' age (p < 0. 01).

CONCLUSIONS

The expressions of these tumor factors are equally intense for both primary and metastatic tissue in papillary thyroid cancer. Despite the small size of the sample, the expressions of IGF-I and PCNA could not be associated to clinical-pathologic features, except for the age. As patients over 40 years old had higher expression of PCNA, this marker may have prognostic significance for patients with papillary thyroid cancer.

Serum cytokines in chronic Chagas' disease

We studied the serum levels of IL-2, IFN-gamma and TNF in different clinical forms of Chagas' disease and in patients clinically compensated and decompensated. Cytokines measured in 91 patients with the chronic form of the disease did not differ from those of 13 normal individuals, suggesting the absence of activation of the TH1 pattern of lymphocyte response. There were no statistical differences among the 17 patients in the indeterminate form of the disease, the patients presenting either early (n = 4) or well-developed signs of cardiomyopathy (n = 62), the digestive (n = 4) or the mixed (n = 4) forms of the disease. Serum TNF was undetectable and IFN-gamma levels did not differ between clinical forms and severities of Chagas' disease. However, we found IL-2 higher levels in the 25 non-controlled patients than in the 66 controlled individuals (p < 0.001). We suggest that IL-2 dosage may be useful as an indicator of the need for more aggressive procedures.

Expression of transforming growth factor beta1, beta2, and beta3 in multinodular goiters and differentiated thyroid carcinomas: a comparative study

The various isoforms of transforming growth factor-beta (TGFbeta) are growth-inhibiting cytokines for cells of epithelial origin. In malignant thyroid tumors, several studies documented a high expression of TGFbeta in the majority of thyroid follicular cells suggesting a possible role as an inhibitor of cell proliferation. In contrast to this uniform pattern of TGFbeta expression in thyroid cancer, scarce and controversial data have been reported on the expression of TGFbeta in benign multinodular goiter. In the present study, we therefore analyzed the expression of TGFbeta1, TGFbeta2, and TGFbeta3 in normal thyroid tissue, multinodular goiters and papillary thyroid carcinomas by immunohistochemistry. In normal thyroid tissue, expression of the 3 TGFbeta isoforms was barely detectable. However, in the carcinomas, almost all epithelial cells displayed immunoreactivity for the three TGFbeta isoforms. In the nodules from multinodular goiters, all 3 isoforms were found to be expressed although the immunolocalization of the 3 proteins was highly variable. TGFbeta-immunostaining was found in scattered clusters of variable size and, its expression pattern was heterogenous among individual cells within single follicles. TGFbeta-positivity was present in spite of immunostaining for proliferating cell nuclear antigen (PCNA), a marker for actively proliferating cells. In conclusion, this study shows that thyroid carcinomas and benign tumors express the TGFbeta1, TGFbeta2, and TGFbeta3 isoforms. In contrast to the abundant and homogeneous expression in differentiated thyroid carcinomas, TGFbeta expression displays a highly variable interfollicular and intrafollicular pattern in multinodular goiters, suggesting an important role of TGFbeta isoforms in tumorigenesis of thyroid cells.

[Comparison of two strategies for the early detection of congenital hypothyroidism]

OBJECTIVE

Compare two different strategies in newborn screening for congenital hypothyroidism, primary TSH in the umbilical cord blood (method 1) and primary T4 in blood collected from the heel in the 2nd day of life (method 2).

METHODS

We compared both strategies in 10,000 newborns, measuring TSH by a sensitive immunofluorimetric assay and T4 by a radioimmunoassay.

RESULTS

Both strategies detected all cases of hypothyroidism (4 cases, 1/2,500 newborns). The recalling index owing to insufficient amount of blood to perform the assays was zero in method 1 and 8.5% (850 newborns) in method 2. The recalling index for confirmation of the results was 0.06% (6 newborns) in method 1 and 2.25% (225 newborns) in method 2; when method 2 included supplementary TSH, the recalling index was reduced to 1.63% (163 newborns).

CONCLUSION

Our data indicate the technical superiority of the umbilical cord blood compared to heel and primary TSH compared to primary T4 in the neonatal thyroid screening for congenital hypothyroidism.

Prospective and controlled study of ophthalmopathy after radioiodine therapy for Graves' hyperthyroidism

The effects of radioiodine (131I) therapy for hyperthyroidism on the ocular process of Graves' disease is controversial. In order to evaluate the outcome of ophthalmopathy after radioiodine therapy for thyrotoxicosis we studied prospectively 30 Graves' hyperthyroid patients, 22 submitted to radioiodine (131I) treatment (group A) and 8 treated with antithyroid drugs (group B). All patients were evaluated by clinical ophthalmologic examination, and ocular proptosis (OP) was measured with both a Hertel exophthalmometer (HE) and computed tomography (CT) before and 4 to 7 months after therapy. No statistical difference was obtained between pre- and post-treatment OP measurements in each eye in either group, and we did not observe worsening in the ophthalmopathy of patients treated with drugs or radioiodine. After therapy, there was an improvement in the clinical signs of ophthalmopathy in 59% of group A and in 37.5% of group B patients. We found a significant correlation between OP measured by HE and by CT. CT findings showed an increase in orbital fat and/or muscle thickening in all patients at baseline, proving to be a useful procedure for ophthalmologic diagnosis in doubtful cases. No patient in either group developed hypothyroidism or elevated TSH levels during the study period; this may explain our good results in the evolution of Graves' ophthalmopathy after treatment with 131I and antithyroid drugs. Euthyroidism seems to be an important factor in the outcome of ophthalmopathy after therapy, whatever the mode of treatment chosen to achieve it.

[Predictive value of the measurement of iodothyronines in the prognosis of patients with severe nonthyroidal illness]

PURPOSE

In order to find prognostic parameters in patients with severe diseases, we analyzed sequentially the levels of thyroid hormones.

METHODS

We measured iodothyronines (T3, T4 and rT3) in 42 patients before the admission and after the discharge in an intensive care unit. In addition, we also measured the iodothyronines in other 17 patients after the discharge.

RESULTS

Comparing the group of good outcome with the patients who died, we observed in the former group initial normal T4 levels in 76% of the patients, which were maintained in 65% of them during hospitalization and in 70% of them at the time of delivery from the intensive care unit. Patients who died, however, presented initial low T4 levels in 56% of them, decreasing values in 95% of them during hospitalization and low levels in 81% of patients at the last dosage. The combined profile of T3 and T4 also differentiated good and bad outcome.

CONCLUSION

We suggest that serial analysis of serum levels of thyroid hormones may help the evaluation of critical care patients.

[Prospective study of the effects of amiodarone on thyroid function in chagasic patients in an area of iodine deficiency]

In order to evaluate the development of thyroid dysfunction during chronic amiodarone treatment in an area deficient in iodine and endemic for Chagas' disease, a group of 24 patients was prospectively studied. Clinical examination and measurement of serum T4, T3, rT3, TSH and antithyroglobulin antibodies were performed before and at 3 and 9 months of use of amiodarone. A TSH response 30 minutes after IV injection of 200 micrograms of TRH was also compared to TSH basal levels before and during amiodarone treatment. Thyroid radioactive uptake and scan were obtained before and nine months after amiodarone was started. Elevated rT3 concentrations were unexpectedly found in two thirds of the patients before treatment. Thyroid dysfunction developed during amiodarone administration in 20.8% of the patients; 12.5% became hyperthyroid and 8.3%, hypothyroid (with negative antithyroglobulin antibodies). Positive RAI uptake was seen in one patient with hyperthyroidism and diffuse goiter. Since T3 levels were not found to increase, the diagnosis of amiodarone-related hyperthyroidism was better evidenced by the reduced or blocked TSH response to TRH. Elevated TSH concentration was the best evidence of amiodarone-induced hypothyroidism. Increase in TSH levels since the beginning of amiodarone therapy may predispose to the growth of a goiter. In conclusion, amiodarone treatment in an iodine deficient area as above should be judiciously decided and thyroid function carefully monitored before and during the use of the drug.

Assessment of the efficacy and safety of nimesulide vs naproxen in paediatric patients with respiratory tract infections. A comparative single-blind study

A total of 99 paediatric patients (57 male, 42 female) aged 1 to 12 years, weighing 10 to 40kg and with acute pharyngo-amygdalitis were enrolled in a single-blind study to assess the efficacy and tolerability of nimesulide in comparison with naproxen when both drugs were administered over an 8-day treatment period. Among the 2 treatment groups comprising 99 evaluable patients, demographic analysis of age, weight and height did not reveal statistically significant differences. Evaluation of fever, pain, inflammation and nasal obstruction over the 8-day treatment period showed a significant improvement in these parameters for those patients treated with nimesulide when compared with naproxen from day 1, with remission of symptoms starting from day 3. These findings were complemented by a superior tolerability profile reported for nimesulide-treated patients. In conclusion, nimesulide appears to be a safe and effective treatment for paediatric patients with pharyngo-amygdalitis and it has shown superior efficacy and tolerability when compared with naproxen.

Outcome of thyroid function in newborns from mothers treated with amiodarone

Amiodarone, a drug extensively used as an antiarrhythmic agent, contains 37% iodine and causes several thyroid abnormalities. The transplacental passage of amiodarone occurs with chronic therapy; we describe in this report the outcome of 9 pregnant women who used amiodarone (200 mg/day) for treatment of resistant tachycardia and the follow-up of their newborns. All women were clinically euthyroid at the 3rd trimester and showed expected values of thyroid hormones (mean +/- SD: total T4, 228 +/- 45 nmol/L; total T3, 4.0 +/- 0.65 nmol/L; TSH, 4.0 +/- 1.8 mU/L; negative thyroid antibodies). At birth all newborns were normal on routine examination with no goiter or corneal changes. T4 and TSH, measured on dried umbilical blood spots were normal or borderline-normal in 8 of 9 babies. Only 1 neonate presented clearly abnormal values of T4 and TSH (96 mU/L); on clinical grounds the baby was normal, without signs of hypothyroidism. At 1 month of life, T4 and TSH were normal. Follow-ups at 3, 6, and 12 months were normal. We conclude that is not necessary to discontinue treatment with amiodarone in pregnant women with resistant tachycardia, but it is imperative to evaluate the thyroid function of the newborn, since transient hypothyroidism may occur.

Immunohistochemical demonstration of insulin-like growth factor I (IGF-1) in normal and pathological human pituitary glands

The authors have studied the presence and distribution of Insulin-Like-Growth-Factor-1 (IGF-1) in 5 autopsied normal and 20 surgically removed human pituitary adenomas, employing a peroxidase-anti-peroxidase method. IGF-1 could be demonstrated in all cases, with variation of cells immunostaining from 60% in normal pituitary gland to 100% in corticotroph cell adenoma.

Demonstration of the production and physiological role of insulin-like growth factor II in rat thyroid follicular cells in culture

Insulin-like growth factors (IGFs) are potent mitogens for FRTL5 rat thyroid follicular cells. IGFs also synergize the independent mitogenic effects of thyrotropin-stimulating hormone (TSH) and other agents that increase intracellular AMP concentration. We examined whether FRTL5 cells and M12 cells, a TSH-independent mutant cell line derived therefrom, secrete IGF that regulates the growth of rat thyroid follicular cells. Immunoreactive IGF-II, but not IGF-I, was found in media conditioned by FRTL5 cells; media from M12 cells contained four- to fivefold higher concentrations. Medium conditioned by FRTL5 and M12 both stimulated [3H]thymidine incorporation in FRTL5 and amplified the mitogenic effects of TSH. M12-conditioned medium was more potent than FRTL5-conditioned medium. Sm-1.2, a monoclonal antibody that recognizes IGF-I and IGF-II but not insulin, inhibited basal DNA synthesis in FRTL5 and M12 cells and the mitogenic effects in FRTL5 of agents that are synergized by IGF, such as TSH, forskolin, Bt2cAMP, and Graves'-IgG. Sm-1.2 did not inhibit the mitogenic response to insulin. Thus, rat insulin-like growth factor II (rIGF-II) is an autocrine growth factor that regulates FRTL5 growth, in part by amplifying the mitogenic response to TSH. Results with M12 cells raise the possibility that endogenous rIGF-II may partially mediate the TSH-independent growth of these cells.

Supranormal stimulation of deoxyribonucleic acid synthesis in FRTL5 cells by serum from patients with untreated acromegaly

Insulin-like growth factor I (IGF-I) is one of a number of mitogenic factors in the serum of animals and humans. We demonstrated previously that IGF-I is a potent mitogen for FRTL5 cells, a line of rat thyroid follicular cells. In this study, we assessed the relevance of this finding with respect to the levels of IGF-I found in human serum by comparing the effects of normal serum and serum from patients with untreated acromegaly or hypopituitarism on DNA synthesis in quiescent FRTL5 cells. As expected, when added to cells maintained in Coon's modified Ham's F-12 medium containing 0.1% BSA, but devoid of insulin, transferrin, TSH, or calf serum, normal serum produced a dose-dependent stimulation of [3H]thymidine incorporation into DNA. A similar, but more marked, effect was produced by the addition of serum from patients with untreated acromegaly. In multiple experiments, a standard concentration (0.5%) of acromegaly serum was more stimulatory to DNA synthesis than was normal serum. In a single experiment designed to eliminate interassay variation and define the relationship between the ability of serum to stimulate DNA synthesis and its IGF-I concentration, studies were performed with 0.5% concentrations of serum from 9 normal subjects, 15 patients with untreated acromegaly, and 3 patients with panhypopituitarism. On the average, [3H]thymidine incorporation in the presence of serum from patients with acromegaly was approximately 3 times, and that in the presence of serum from patients with hypopituitarism only one fourth, that in the presence of serum from normal subjects; there was no overlap of individual values in the three groups. For the entire study group, we found a highly significant correlation (r = 0.86) between the serum IGF-I concentration and the ability of that serum to stimulate thymidine incorporation into the DNA of FRTL5 cells. The stimulatory effects of serum from both normal and acromegalic subjects were decreased or abolished by the addition of a monoclonal antibody against IGF-I. In hypophysectomized rats, GH increases the thyroid to body weight ratio and enhances the effect of TSH to promote thyroid growth. Further, an inordinate frequency of nontoxic goiter in patients with acromegaly has been reported. Taken together with these observations, our findings suggest that the effect of IGF-I to promote thyroid cell growth in vitro has a counterpart in the living animal or patient.

Measurement of T4, T3 and reverse T3 levels, resin T3 uptake, and free thyroxin index in blood from the intervillous space of the placenta, in maternal peripheral blood, and in the umbilical artery and vein of normal parturients and their conceptuses

T4, T3, and reverse T3 (rT3) levels and the free thyroxine index were measured in blood collected from the intervillous space (IVS) after placental expulsion and compared to the values in maternal peripheral blood and in umbilical artery and umbilical vein of 21 clinically normal parturients and their conceptuses. T4 levels in maternal peripheral blood did not differ significantly from T4 levels in the IVS, but were significantly higher than those detected in umbilical vein and artery (p less than 0.05). There was no difference in T4 levels between umbilical vein and artery. The free thyroxine index was similar for the maternal compartments (maternal peripheral blood and IVS), but differed significantly from the fetal compartments (umbilical vein and umbilical artery). T3 levels in maternal peripheral blood were significantly higher than in the IVS, both of these values being significantly higher than in the fetal compartments. There was no difference in T3 levels between umbilical vein and artery. rT3 levels of maternal peripheral blood were one third that of the IVS (p less than 0.05). rT3 levels of the umbilical vein were 1.5 times higher than those of the IVS (p less than 0.05) and 5.2 times higher than those of maternal peripheral blood (p less than 0.005). No significant difference was obtained between umbilical vein and artery. The increase in rT3 and the decrease in T3 in the IVS in relation to maternal peripheral blood support the hypothesis that the placenta may preferentially convert T4 to rT3 at the expense of T3. The present data, however, do not permit the identification of the site where this conversion takes place.

The role of glucocorticoids in the stress-induced reduction of extrathyroidal 3,5,3'-triiodothyronine generation in rats

Serum concentrations of T4, T3, and rT3 as well as liver and kidney 5'-deiodinase activity, have been examined in rats stressed by restraint. After immobilization, serum concentrations of T3 decreased significantly (6 hr, -33 +/- 1%; 8 h, -42 +/- 3%), while serum rT3 increased (6 h, +55 +/- 3%; 8 h, +75 +/- 5%). In the same or similarly treated animals, there was a time-dependent reduction in T4 5'-deiodinase activity in both liver (4 h, -23 +/- 2%; 8 h, -43 +/- 3%) and kidney (4 h, -18 +/- 1%; 8 h, -42 +/- 3%) homogenates. The reduction in hepatic and renal T3 production was due to reduced enzyme activity and not to reduced substrate availability. In spite of reductions in serum TSH (4 h, -9 +/- 1%; 8 h, -51 +/- 5%), the serum T4 concentration did not fall. The serum concentration of corticosterone reached 30 times the basal level after 8 h of restraint. Either adrenalectomy or metyrapone treatment, followed by replacement with nonstress doses of B, completely prevented the alterations of iodothyronine metabolism induced by restraint. These results indicate that the stress-induced elevation of plasma glucocorticoids plays a key role in the pathogenesis of the low T3 syndrome in this model. The reduction in serum T3 may be accounted for by a reduction in T3 production by liver and kidney, adding support to the concept that these organs are an important source of plasma T3 in the rat.

Development of an homologous radioimmunoassay for the synthetic amino terminal (1-34) fragment of human parathyroid hormone using egg yolk-obtained antibodies

An homologous radioimmunoassay for the synthetic 1-34 amino terminal fragment of human parathyroid hormone (hPTH) was developed using antibodies obtained from yolk of eggs layed by an immunized chicken. The 125I labelled 1-34 hPTH peptide was purified by cation-exchange chromatography which provided a highly stable preparation. The specificity of the assay showed a cross-reactivity of 50% with the 1-34 hPTH (code 81/574) preparation and 27% with the 1-84 hPTH (code 79/500) preparation, when compared with the 1-34 hPTH from Bachem that was used for immunization and labelling. The minimal detectable dose of the assay was 10 pmol/l; in 69 healthy controls the values obtained ranged from less than 10 to 28 pmol/l and in 14 patients with surgically proven primary hyperparathyroidism from 10 to 519 pmol/l.

Egg yolk as a source of antibodies for human parathyroid hormone (hPTH) radioimmunoassay

Chickens were immunized with synthetic hPTH peptides 1-34 and 53-84. Serum from the best responder of each group was compared with IgG obtained from yolk of eggs layed by the same chicken, showing similar properties. A simple method for purification of IgG from yolk is described, allowing the obtaining of substantial amounts of anti-hPTH IgG without the need for bleeding the animals. We conclude that: 1) egg from chickens immunized with synthetic hPTH peptides are a convenient source of antibodies against these peptides; 2) this principle should apply to any other antigen to which chickens are good responders.

Hemiagenesis of the thyroid gland and T3 hyperthyroidism

A patient with hemiagenesis of the thyroid gland who presented with T₃ toxicosis is described. The diagnosis of thyroidal hemiagenesis was established through the administration of thyroid stimulating hormone and a thyroid scintiscan.

T₃ thyrotoxicosis is a previously unreported clinical presentation of thyroid hemiagenesis.

Subcellular localization of thyroxine and reverse triiodothyronine outer ring monodeiodinating activities

In order to examine the subcellular localization of outer ring T4- and rT3-monodeiodinating activities, nuclear, mitochondrial, microsomal, cytosol, and plasma membrane fractions of rat liver homogenate were incubated with either T4 or rT3 in phosphate buffer (pH 7.35) in the presence of 2 mM dithiothreitol for 15 min at 37 C, and the amount of product (T3 in the case of T4 and 3,3'-diiodothyronine in the case of rT3) was measured by specific RIA. The various tissue fractions were also examined for the relative concentration of various marker enzymes. T4 and rT3 monodeiodinating activities correlated better with enzyme markers of plasma membranes than of any other subcellular fraction in most tissue fractions. A fraction could be isolated, however, in which the monodeiodinating activities correlated better with the enzyme markers of microsomes than of plasma membranes. The various data suggest that plasma membranes and microsomes are two main sites of T4- and rT3-monodeiodinating activities. The location of T4 to T3 converting activity in the plasma membranes may serve to modulate the delivery of the more potent thyroid hormone, i.e. T3, into the cells.

3'-5'-Diiodothyronine in health and disease: studies by a radioimmunoassay

A simple, reproducible, and highly specific RIA has been developed for measurement of 3',5'-diiodothyronine ((3',5'-T2) in unextracted serum. Interference in binding of radioactive 3',5'-T2 to anti-3',5'-T2 by serum proteins was minimized by using 0.4 M phosphate buffer (pH 6.2) and merthiolate. The detection threshold of the RIA was 2.5 ng/100 ml. Recovery of nonradioactive 3',5'-T2 added to serum averaged 99%. T4, T3, and rT3 cross-reacted with 3',5'-T2-binding sites on anti-3',5'-T2 antibody only to the extent of 0.0025, less than 0.0004, and 0.22%, respectively. 3'-Monoiodothyronine cross-reacted 1.7%. Serum 3',5'-T2 concentrations were (mean +/- SD) 6.4 +/- 2.4 ng/100 ml in 53 normal subjects, 4.2 +/- 3.5 ng/100 ml in 7 hypothyroid patients, 14.9 +/- 7.7 ng/ml in 25 patients with hepatic cirrhosis, and 14.3 +/- 5.3 ng/100 ml in 31 newborns' cord blood sera. The values in each of the latter four groups were significantly different from normal. The mean serum 3',5'-T2 concentration of 7.7 +/- 2.5 ng/ml in eight subjects in the third trimester of pregnancy did not differ significantly from normal at a time when serum T4 and T3 were clearly elevated. Oral administration of 300 microgram rT3 to 9 normal subjects led to a mean maximal increase in serum 3',5'-T2 concentration of 45% at 1 h. Total fasting in 3 obese subjects was associated with a significant increase in serum 3',5'-T2 from 8.6 to 16.3 ng/100 ml at 6-8 days; serum rT3 increased similarly, while serum T3 decreased and T4 did not change. Administration of dexamethasone (2 mg also associated with nearly parallel increases in serum 3',5'-T2 and rT3 and a decrease in serum T3. 3',5'-T2 concentrations were also measured in amniotic fluids at different stages of gestation; the mean value of 15.2 ng/100 ml at 15-20 weeks gestation was significantly higher than that of 5.8 ng/ml at 33-40 weeks gestation. Pronase hydrolysates of 9 autopsy specimens of normal thyroid glands contained (mean +/- SD) 350 +/- 144 microgram T4 and 0.24 +/- 0.15 microgram 3',5'-T2/g wet wt. On the basis of these data and those available for MCRs of 3',5'-T2 and T4, it was estimated that thyroidal secretion contributes less than 1% of 3',5'-T2 measured in serum of normal man. The various data suggest that: 1) 3',5'-T2 is a normal component of human serum; 2) almost all 3',5'-T2 in human serum derives from extrathyroidal sources; and 3) changes in serum 3',5'-2 generally parallel those in rT3.

Peripheral blood T and B lymphocytes, in vitro stimulation with phytohemagglutinin, and sensitization with 2,4-dinitrochlorobenzene in Grave's disease

The percentage and absolute numbers of thymos-dependent (T) and thymos-independent (B) peripheral blood lymphocytes, the in vitro response of lymphocytes to phytohemagglutinin (PHA), and the sensitization with 2,4dinitrochlorobenzene (DNCB) was studied in 26 patients with hyperthyroidism due to Graves' disease. The results showed a normal percentage of both T and B cells and increased absoluted numbers of total lymphocytes in patients compared with 30 healthy controls. The in vitro response to PHA was normal in most patients with the exception of 5 of them who showed an impaired response. All patients developed a reaction of delayed hypersensitivity to DNCB. Our study indicated that there is no general abnormality in cell-mediated immunity in Graves' disease.