Sonographic measurement of thyroid volumes in healthy Chinese infants aged 0 to 12 months

Genetic and Phenotypic Characteristics of Congenital Hypothyroidism in a Chinese Cohort

BACKGROUND

The molecular etiology and the genotype-phenotype correlation of congenital hypothyroidism (CH) remain unclear.

METHODS

We performed genetic analysis in 42 newborns with CH using whole-exome sequencing. Patients were divided into a single-gene group and a multi-gene group according to the number of affected genes, or divided into a monoallelic group, a biallelic group, and an oligogenic group according to the pattern of the detected variants. The clinical characteristics were compared between groups.

RESULTS

Thyroid dysgenesis (TD) was observed in 10 patients and goiter in 5 patients, whereas 27 patients had normal-sized gland-in-situ (GIS). We identified 58 variants in five genes in 29 patients. The genes with the most frequent variants were DUOX2 (70.7%), followed by TSHR (12.1%), DUOXA2 (10.3%), and TPO (5.2%). Variants in the genes causing dyshormonogenesis (DH) were more common than those in the genes causing TD (87.9% versus 12.1%). Among the patients with detected variants, 26 (89.7%) were harboring a single gene variant (single-gene group), which include 22 patients harboring biallelic variants (biallelic group) and four patients harboring monoallelic variants (monoallelic group). Three (10.3%) patients harbored variants in two or three genes (multi-gene group or oligogenic group). Compared with the single-gene group, the levothyroxine (L-T4) dose at 1 year of age was higher in the multi-gene group (p = 0.018). A controllable reduction in the L-T4 dose was observed in 25% of patients in the monoallelic group and 59.1% of patients in the biallelic group; however, no patients with such reduction in the L-T4 dose were observed in the oligogenic group.

CONCLUSIONS

Patients with normal-sized GIS accounted for the majority of our cohort. Genetic defects in the genes causing DH were more common than those in the genes causing TD, with biallelic variants in DUOX2 being dominant. DH might be the leading pathophysiology of CH in Chinese individuals.

Determination of thyroid volume in infants with suspected congenital hypothyroidism-the limitations of both subjective and objective evaluation

Objective:

To compare two methods of assessing gland size on thyroid ultrasound in newborn infants with suspected congenital hypothyroidism (CH).

Methods:

Images from infants with eutopic glands referred between 2007 and 2013 were evaluated blind by two sets of observers. Subjective gland size was categorised as small, borderline-small, normal, borderline-large and large. Objective gland volume, calculated as the sum of each lobe using the prolate ellipsoid formula (length x width x depth x π/6), was put into corresponding categories: <0.8, 0.81–1.0, 1.1– <2.2, 2.2–2.4 and >2.4 ml, derived from normative Scottish data.

Results:

Of 36 infants, permanent CH was present in 17, transient CH in 17, status uncertain in 2. Mean (SD) intraobserver error for thyroid volume measurement was 0.11 (0.23) ml [8.3%]. Subjective assessment by two observers was discordant in only four (10.8%) infants. However, subjective vs objective evaluation was discordant in 14 (39%). Eight (three permanent, five transient CH) had large glands subjectively but normal glands objectively; and six (four transient CH) had normal glands subjectively but small glands objectively. The former infants all showed a single flattened curve to the anterior thyroid margin, giving an impression of bulkiness. Gland shape was normal in the latter infants.

Conclusion:

Neither subjective nor objective evaluation predicts permanent vs transient CH. Altered gland shape may confound both methods, and undermine use of the conventional formula for measuring lobe volume.

Advances in knowledge:

Until more refined methods are available for assessing thyroid size, both subjective and objective evaluation are recommended in CH.

Defining Normative Sonographic Measurements of Neonatal Thyroid Volumes: Results of 165 Healthy Neonates from a Single Center in Northwest Malaysia

Background:

Congenital hypothyroidism is the most common cause of treatable mental impairment and growth retardation in newborns. Early diagnosis requires measurement of serum thyroid-stimulating hormone (TSH) and free T4 coupled with an ultrasound of the thyroid gland. However, detailed sonographic evaluation of the thyroid gland requires comparison to the local thyroid normative volumetric values, which is currently lacking.

Methods:

A cross-sectional study was conducted from November 10, 2015, to April 18, 2018, recruiting 165 healthy neonates with normal TSH in their 1^st week of life, from a single center in Northwest Malaysia. Ultrasound thyroid was done by a single ultrasonographer (κ = 0.86, percent agreement = 92.4), and the thyroid volume (TV) was calculated using the Brunn formula.

Results:

All measurements showed skewed distribution with no significant difference between the right and left lobes. The local normative values for neonatal total TV was 0.61 (interquartile range [IQR] = 0.230) cm³, 0.31 (IQR = 0.150) cm³ for right TV, and 0.28 (IQR = 0.110) cm³ for left TV. There was a strong correlation between the right and left TVs, r = 0.767, P < 0.001. There were also no differences in the total TV across different genders and races.

Conclusion:

The normative values for TV determined in our study may be used accordingly in clinical practice to evaluate thyroid hypoplasia or goiter by other Asian countries due to the similarly shared biodemography.

Thyroid gland volumes in premature infants using serial ultrasounds

BACKGROUND

There is a gap in knowledge about the postnatal growth of thyroid gland in preterm infants.

OBJECTIVE

To determine postnatal growth of thyroid gland in preterm infants.

METHODS

Thyroid gland volume was calculated in 57 prospectively enrolled preterm infants by measuring serial longitudinal, antero-posterior, and transverse dimensions of thyroid gland with ultrasound. Data were analyzed by using the Wilcoxon and independent t test.

RESULTS

There was a significant correlation between thyroid volume (TV) and birthweight (BW) (p = 0.01), and between TV and gestational age (p = 0.02). However, unexpectedly, 12 infants had a decrease in TV between the first and second ultrasounds. Infants with late onset bacterial sepsis had lower TVs on their second ultrasounds than infants without sepsis.

CONCLUSIONS

Thyroid ultrasound in preterm infants provides noninvasive and quick approach to determine TV and morphology. TV in preterm infants correlates positively with BW and gestational age. However, postnatal growth of thyroid gland is variable and may seemingly be affected by postnatal factors.

Ultrasound Measurements of Thyroid Gland Volume at 36 Weeks' Corrected Gestational Age in Extremely Preterm Infants Born before 28 Weeks' Gestation

BACKGROUND

Thyroid ultrasound is a non-invasive imaging tool and provides good evaluation of thyroid anatomy, location, vascularisation, and echogenicity. The aim of this study was to assess thyroid function and thyroid volume in extremely preterm infants born before 28 weeks' gestation evaluated at 36 weeks' corrected gestational age (CGA) compared to term infants' normative data in the literature.

DESIGN

In this largest prospective UK study of extremely premature infants born at less than 28 weeks' gestation, thyroid volume measurement was assessed at 36 weeks' CGA. Fifty-five extremely preterm infants (28 males) who were born before 28 weeks' gestation were recruited to the study. All infants had ultrasound assessment of the thyroid gland at 36 weeks' CGA. We also prospectively measured thyroid stimulating hormone (TSH) and free thyroxine (FT4) in all infants at the time of recruitment (within 5 days of birth), at days 14, 21, and 28, and at 36 weeks' CGA.

RESULTS

The mean thyroid volume was measured at 0.57 mL (SD ±0.18). There was no association between mean thyroid volume and thyroid function (TSH or FT4). No associations were found between mean thyroid volume and gestation or birth weight in these infants.

CONCLUSIONS

Our findings provide a reference range with a mean thyroid volume of 0.57 mL (SD ±0.18) in this extremely preterm age group if less than 28 weeks' gestation. Thyroid volume at birth can vary from country to country due to variations in iodine intake as well as gestational age.

Thyroid Imaging in Infants

Congenital hypothyroidism is the most common preventable cause of mental retardation. It is important to know the cause of each patient's thyroid dysfunction to foresee the course of therapy and outcomes. Imaging methods, such as ultrasound and thyroid scan, help determine the anatomy and function of the thyroid gland. Although thyroid scan is considered superior in detecting ectopic thyroid tissue, ultrasound is able to detect the presence of thyroid tissue not otherwise visualized in 15% of patients.

Sonographic evaluation of the thyroid size in neonates

PURPOSE

To validate the use of the ratio between the total transverse diameters of the thyroid lobes (Th) and the width of the trachea (Tr)-the Th:Tr or Yasumoto ratio-as a sonographic method for estimating thyroid size, and to determine reference values for this ratio and for thyroid volume in neonates.

METHODS

In this cross-sectional study, we evaluated thyroid size according to the Yasumoto ratio and the thyroid volume calculated with the ellipsoid formula in 125 healthy, euthyroid, iodine-sufficient, full-term neonates.

RESULTS

The mean thyroid gland volume was 1.00 ml (95% confidence interval, 0.95-1.03 ml), and the mean Yasumoto ratio was 2.29 (95% confidence interval, 2.21-2.31). The lower- and upper-limit results falling within 2 SDs of the mean were 0.45 ml and 1.53 ml for the volume and 1.71 and 2.87 for the ratio.

CONCLUSIONS

In full-term, euthyroid, iodine-sufficient neonates, the normal reference interval for thyroid volume measured on sonography was 0.45-1.53 ml and that for the Yasumoto ratio was 1.71-2.87. A ratio of 1.7 may be applied as the cutoff value for sonographic diagnosis of thyroid dysgenesis in full-term neonates with congenital hypothyroidism. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound 43:224-229, 2015.

Influence of deleted in colorectal carcinoma gene on proliferation of ovarian cancer cell line SKOV-3 in vivo and in vitro

OBJECTIVE

To elucidate the effects of the deleted in colorectal carcinoma (DCC) gene on proliferation of ovarian cancer cell line SKOV-3.

METHOD

An exogenous recombinant eukaryotic expression vector pcDNA3.1(+)-DCC, containing human DCC cDNA coding sequences, was constructed and transfected into SKOV-3 cells (SKOV-3/DCC). The pcDNA3.1 (+) transfected cells (SKOV-3/Neo) and SKOV-3 cells were used as the positive and negative controls, respectively. Expressions of DCC mRNA and protein were analyzed by RT-PCR and immunocytochemical analysis, respectively. Cell growth was detected by soft agar colony formation assay and MTT assay. Flow cytometry and transmission electron microscopy were used to assess the effects of DCC on cell cycle distribution and ultrastructure, respectively. BALB/c mice were used to evaluate the effects of DCC on tumorigenicity in vivo.

RESULTS

RT-PCR and immunocytochemical analysis revealed the exogenous DCC gene was successfully transfected into SKOV-3 cell lines and obtained permanent expression. The half maximal inhibitory concentration (IC50) of SKOV-3/DCC cells was significantly lower than that of SKOV-3 or SKOV-3/Neo cells (all P<0.05). DCC expression caused SKOV-3 cells to be arrested in G1 phase (78.0%), and electron microscopic analysis showed SKOV-3/DCC cells displayed typical morphological changes of apoptosis. Two mice xenografted with SKOV-3/DCC cells showed no tumor tumorigenecity. The tumor volume of BALB/c mice bearing SKOV-3/DCC cells (3.403 mm(3)) was smaller than that of SKOV-3 cells (9.206 mm(3)).

CONCLUSION

DCC gene may play an important role in suppressing the growth of SKOV-3 cell line and inducing apoptosis.