Thyroid homeostasis in B6C3F1 mice upon sub-chronic exposure to trifluoroiodomethane (CF3I)

2021 ◽  
pp. 074823372110196
Author(s):  
Thomas A. Lewandowski ◽  
Gensheng Wang ◽  
Matthew D. Reed ◽  
Andrew P. Gigliotti ◽  
Joel M. Cohen ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Health Effect ◽  
Species Difference ◽  
Recovery Period ◽  
Clinical Signs ◽  
Thyroid Stimulating Hormone ◽  
Male Rats ◽  
Whole Body ◽  
Male Mice ◽  
Fire Suppressant

Trifluoroiodomethane (CF3I) is a fire suppressant gas with potential for use in low global-warming refrigerant blends. Data from studies in rats suggest that the most sensitive health effect of CF3I is thyroid hormone perturbation, but the rat is a particularly sensitive species for disruption of thyroid homeostasis. Mice appear to be less sensitive than rats but still a conservative model with respect to humans. The purpose of this study was to test tolerance and thyroid response to CF3I in B6C3F1 male mice. Male mice were exposed to CF3I for 6 h per day, for 28 days, via whole body exposure at concentrations of 2500, 5000 and 10,000 ppm. A 16-day recovery period was included to evaluate reversibility. No adverse clinical signs were observed throughout the study, and body weights were unaffected by exposure. CF3I exposure had no effect on thyroid histology. An increase in relative thyroid weight was observed at 10,000 ppm on day 28 but not in a separate group of animals evaluated on day 29, and thyroid weight was not different from controls at 44 days. Slight and sporadic changes in serum triiodothyronine, thyroxine, and thyroid-stimulating hormone were observed but did not follow a consistent pattern with respect to timing, dose, or direction. Overall, exposure at up to 10,000 ppm (1.0%) of CF3I gas for 28 days produced no overt general toxicity and only transient, recoverable effects on thyroid weight and hormones at certain concentrations. On the basis of the effect of CF3I exposure on the thyroid, including evaluation of thyroid histopathology, the no observed adverse effect level for this study is 10,000 ppm. Considering the apparently greater toxicity reported in prior studies in male rats, our data suggest a species difference between rats and mice in terms of susceptibility to CF3I-induced thyroid hormone perturbation.

The Subchronic Oral Toxicity of Ethane, 1,2-Bis(pentabromophenyl) (Saytex 8010) in Rats

2002 ◽  
Vol 21 (3) ◽  
pp. 165-170 ◽  
Author(s):  
M. L. Hardy ◽  
D. Margitich ◽  
L. Ackerman ◽  
R. L. Smith
Keyword(s):  
Corn Oil ◽  
Clinical Chemistry ◽  
Recovery Period ◽  
Clinical Signs ◽  
Female Rats ◽  
Male Rats ◽  
High Dose ◽  
Low Grade ◽  
Oral Toxicity ◽  
Effect Level

Ethane, 1,2-bis(pentabromophenyl) (EBP; CAS no. 8452–53–9) dose levels of 0, 100, 320 and 1000 mg/kg/day administered to rats by gavage in corn oil for 90 consecutive days produced no compound-related clinical signs of systemic toxicity, ocular lesions, or alterations in urinalysis, clinical chemistry, and hematology values in the treated or recovery groups. No biologically or toxicologically significant differences were observed in body weights, body weight gains, and food consumption. Statistically significant differences were found between control and high-dose animals in mean absolute or relative liver weights. Histomorphological evaluation showed in male rats low-grade liver changes consisting of minimal to slight hepatocellular vacuolation (high-dose males) and minimal to slight centrilobular hepatocytomegaly (high- and possibly mid-dose males). These changes had resolved by the end of the 28-day recovery period. No treatment-related changes were found in the livers of female rats. No treatment-related histomorphologic changes were present in any of the other tissues examined in either sex, except for evidence of aspirated test article in individual rats. The 90-day EBP no-adverse-effect level in the rat was 1000 mg/kg/day, and was consistent with that of the preceding 28-day study (no-effect level 1250 mg/kg/day). EBP's lack of toxicity is likely related to poor bioavailability due to its high molecular weight and low solubility.

Effect of goitrogen administration on the circadian rhythm of serum thyroid stimulating hormone in the rat

1981 ◽  
Vol 98 (3) ◽  
pp. 396-401 ◽  
Author(s):  
B. Stringer ◽  
D. Wynford-Thomas ◽  
B. Jasani ◽  
E. D. Williams
Keyword(s):  
Circadian Rhythm ◽  
Thyroid Hormone ◽  
Circadian Rhythms ◽  
Thyroid Function ◽  
Diurnal Rhythm ◽  
Thyroid Stimulating Hormone ◽  
Male Rats ◽  
Hormone Synthesis ◽  
Serum Tsh

Abstract. Adult male rats were fed a goitrogen, aminotriazole, for 74 days at a dose known to suppress thyroid function completely. At the end of this period, these animals along with matched controls were killed in groups of seven at 3 hourly intervals throughout a 24 hour period, and serum TSH, T3, T4 and albumin assayed. No significant circadian rhythms of T3, T4 or albumin were found in either, but a highly significant rhythm of TSH was demonstrated both in controls and goitrogen treated groups, with a diminished relative amplitude in the latter. The results indicate that a significant diurnal rhythm of serum TSH persists in the rat despite long-term blockade of thyroid hormone synthesis and that the existence of this rhythm is therefore independent of the presence of circulating T3 or T4.

scholarly journals Compliance with follow-up and the informative value of diagnostic whole-body scan in patients with differentiated thyroid carcinoma given recombinant human TSH

2004 ◽  
Vol 150 (3) ◽  
pp. 285-290 ◽  
Author(s):  
O Cohen ◽  
S Dabhi ◽  
A Karasik ◽  
S Zila Zwas
Keyword(s):  
Thyroid Hormone ◽  
Differentiated Thyroid Carcinoma ◽  
Thyroid Stimulating Hormone ◽  
Whole Body ◽  
Human Thyroid ◽  
Whole Body Scan ◽  
Body Scan ◽  
Thyroid Hormone Withdrawal ◽  
Tertiary Referral Center

OBJECTIVE: Protocols for monitoring patients with differentiated thyroid cancer (DTC) include measurement of serum Tg and, for most patients, whole-body scan (WBS) with low radioiodine activities ('diagnostic' WBS). Recently, recombinant human thyroid-stimulating hormone (rhTSH) has become available to provide the TSH stimulation necessary for these procedures, whilst avoiding thyroid hormone withdrawal and hypothyroid complications. In addition, the inclusion of diagnostic WBS in DTC follow-up has recently become controversial. We have assessed the compliance with withdrawal-aided monitoring and the informative value of diagnostic WBS in consecutive tertiary referral center patients. DESIGN: Forty-eight patients received rhTSH (0.9 mg) in two consecutive daily injections, with radioiodine administration 24 h, diagnostic WBS 48 h, and serum Tg testing prior to and 72 h later. METHODS: Compliance with withdrawal-aided monitoring was assessed with a questionnaire provided by the referring physician, patient record analysis, and patient interview. The informative value of diagnostic WBS was assessed by comparing findings against serum Tg measurements in light of physical and other radiological examinations. RESULTS: Forty of the forty-eight patients were female, the mean age was 43.9 years and the median follow-up from diagnosis was 4.5 years (range 1-19 years). Twenty-seven (56%) patients were compliant and 12 (25%) were non-compliant; compliance was not known in nine. Of 17 patients with clinically suspicious or significant findings on any available modality, four had uptake outside the thyroid bed on WBS but stimulated Tg <2.5 ng/ml on immunometric assay, while five had a negative WBS with serum Tg >2.5 ng/ml. CONCLUSIONS: Thyroid hormone withdrawal substantially impairs, and rhTSH administration substantially promotes, compliance with DTC monitoring. rhTSH-aided WBS is informative and should be included in the follow-up of unselected patients with DTC.

Congenital Feline Hypothyroidism With Partially Erupted Adult Dentition in a 10-Month-Old Male Neutered Domestic Shorthair Cat: A Case Report

2018 ◽  
Vol 35 (3) ◽  
pp. 178-186 ◽  
Author(s):  
Teresa Jacobson ◽  
Judy Rochette
Keyword(s):  
Case Report ◽  
Thyroid Hormone ◽  
Short Stature ◽  
Clinical Signs ◽  
Thyroid Stimulating Hormone ◽  
Permanent Dentition ◽  
Gingival Tissue ◽  
Short Neck ◽  
Hair Coat ◽  
Pendulous Abdomen

Congenital feline hypothyroidism was diagnosed in a 10-month-old kitten. The kitten appeared to have disproportionate dwarfism, with the clinical signs of incompletely erupted permanent dentition covered by thickened gingival tissue, short stature, a broad, flattened face, short neck, pendulous abdomen, kitten-like hair coat, and goiter. Hypothyroidism was confirmed with baseline T4, freeT4, and thyroid-stimulating hormone testing. The kitten was treated with thyroid hormone supplementation and monitored. The kitten appeared clinically like a normal healthy cat at 22 months of age on thyroid supplementation.

scholarly journals STUDY OF THE «ACUTE» TOXICITY OF LIPOSOMAL DRUG FORM OF ANTINEOPLASTIC PHOTOSENSITIZER THIOSENS

2015 ◽  
Vol 14 (3) ◽  
pp. 49-54 ◽  
Author(s):  
N. Yu. Kulbachevskay ◽  
E. V. Sanarova ◽  
O. I. Konyeva ◽  
N. P. Ermakova ◽  
V. M. Buchman ◽  
...  
Keyword(s):  
Acute Toxicity ◽  
Dosage Form ◽  
Dose Range ◽  
Clinical Signs ◽  
Male Rats ◽  
Male Mice ◽  
Preclinical Research ◽  
Male And Female ◽  
Liposomal Drug ◽  
Series Of Experiments

The laboratory for development of drug forms, N.N. Blokhin Russian Cancer Research Center developed a lyophilized liposomal dosage form (LLDF) of a new infrared photosensitizer phthalocyanine derivative - Thiosens. Previous studies determined optimal composition of the dosage form, technology of its production and methods of analysis; a number of biological experiments were performed. The next step of preclinical research is studying "acute" toxicity of LLDF, which is presented in this paper. The study of "acute" toxicity of LLDF Thiosens was carried out in the laboratory of Pharmacology and Toxicology. "Acute" toxicity of LLDF Thiosens was studied in the experiments on mice hybrids F1 (CBA » C57Bl / 6J) male and female and weinbrener outbred male rats. In the first series of experiments LLDF Thiosens was administered to male mice in the dose range of 5; 10; 20 and 30 mg/kg. In the second series of experiments, male and female mice were injected with LLDF Thiosens in the dosage range 6; 12 and 24 mg/kg. Male mice were treated by LLDF Thiosens intravenously; no symptoms of toxicity were registered at the doses of 5 and 10 mg/kg; death was observed in all experimental animals after administration at the doses of 20 and 30 mg/kg on the first day in the result of inactivity and piloerection. In the second series of experiments no sex differences were found in single intravenous injection of LLDF Thiosens. The results of the studies of "acute" toxicity in rats demon strated that when LLDF Thiosens was administered in doses 3, 6 and 9 mg/kg animal deaths were reported. A single intravenous LLDF Thiosens administration in rats in the excess of the expected dose for human in 1.5-4.5 times was well tolerated by the animals: animal mortality, clinical signs of toxicity and changes in behavioral responses were absent.

scholarly journals Metastatic Follicular Thyroid Carcinoma Secreting Thyroid Hormone and Radioiodine Avid without Stimulation: A Case Report and Literature Review

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Syed A. Abid ◽  
Brendan C. Stack ◽  
Donald L. Bodenner
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Carcinoma ◽  
Follicular Thyroid Carcinoma ◽  
Cervical Vertebrae ◽  
Lung Nodule ◽  
Thyroid Stimulating Hormone ◽  
Whole Body ◽  
Rapid Progression ◽  
Free T4 ◽  
Metastatic Lesions

Introduction. This is an extremely rare case of a patient with metastatic follicular thyroid cancer who continued to produce thyroid hormone and was iodine scan positive without stimulation after thyroidectomy and radioiodine (I-131) therapy.Patient Findings. A 76-year-old Caucasian male was diagnosed with metastatic follicular thyroid carcinoma on lung nodule biopsy. Total thyroidectomy was performed and he was ablated with 160 mCi of I-131 after recombinant human thyrotropin (rhTSH) stimulation. Whole body scan (WBS) after treatment showed uptake in bilateral lungs, right sacrum, and pelvis. The thyroglobulin decreased from 2,063 to 965 four months after treatment but rapidly increased to 2,506 eleven months after I-131. Thyroid stimulating hormone (TSH) remained suppressed and free T4 remained elevated after I-131 therapy without thyroid hormone supplementation. He was treated with an additional 209 mCi with WBS findings positive in lung and pelvis. Despite I-131, new metastatic lesions were noted in the left thyroid bed and large destructive lesion to the first cervical vertebrae four months after the second I-131 dose.Conclusions. This case is exceptional because of its rarity and also due to the dissociation between tumor differentiation and aggressiveness. The metastatic lesions continued to secrete thyroid hormone and remained radioiodine avid with rapid progression after I-131 therapy.

Genistein Increase Thyroid Hormone and 7 alpha-hydroxycholesterol concentrations in the liver of middle-aged male rats

2018 ◽  
Author(s):  
Branka Sosic-Jurjevic ◽  
Dieter Lutjohann ◽  
Dragana Miljic ◽  
Jasmina Ciric ◽  
Svetlana Trifunovic ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Male Rats ◽  
Middle Aged ◽  
Middle Aged Male
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