1.Molecular cytogenetic analysis and diagnosis of three fetuses with psu idic(Y)(q11.22) using a combination of multiple techniques.
Xuejiao CHEN ; Meizhen DAI ; Milei ZHU ; Weiwu SHI
Chinese Journal of Medical Genetics 2025;42(3):360-367
OBJECTIVE:
To explore the molecular cytogenetic characteristics of three fetuses with psu idic(Y)(q11.22) using a combination of multiple methods.
METHODS:
A total of 11 000 pregnant women who underwent prenatal diagnosis at the Prenatal Diagnosis Center of Taizhou City from January 2019 to October 2024 were selected as the study subjects. Chromosome karyotype analysis (G-banding) and copy number variation analysis based on next-generation sequencing (NGS) were performed on the amniotic fluid/cord blood samples of the 11 000 fetuses. For cases suspected of Y chromosome abnormalities, C-banding and/or fluorescence in situ hybridization (FISH) and AZF microdeletion testing were additionally conducted. This study has been reviewed and approved by the Medical Ethics Committee of Taizhou Hospital, Zhejiang Province (Ethics No. KL20240860).
RESULTS:
Among the 11,000 prenatal samples undergoing concurrent karyotype and copy number variation analysis, two fetuses with 45,X/46,X,psu idic(Y)(q11.22) mosaicism and one fetus with 46,X,psu idic(Y)(q11.22) were detected. FISH detection indicated that approximately 66.7% of the cells in fetus 2 exhibited a dicentric Y chromosome, and the metaphase karyotype supported the presence of a pseudodicentric chromosome. AZF testing revealed complete deletion of the AZFb+AZFc regions in fetus 2 and fetus 3.
CONCLUSION
Conventional G-banding karyotype analysis for psu idic(Y)(q11.22) is prone to misdiagnosis or missed diagnosis. The combined application of chromosome karyotype analysis (G+C banding), copy number variation analysis, and FISH detection in clinical practice can accurately diagnose fetuses with psu idic(Y).
Humans
;
Female
;
Pregnancy
;
Prenatal Diagnosis/methods*
;
DNA Copy Number Variations/genetics*
;
Adult
;
Chromosomes, Human, Y/genetics*
;
Karyotyping
;
In Situ Hybridization, Fluorescence
;
Cytogenetic Analysis/methods*
;
Fetus
;
High-Throughput Nucleotide Sequencing
;
Male
2.Application value of chromosomal microarray analysis for the detection of low-level mosaicisms in amniotic fluid samples and analysis of rare cases.
Huiyuan SHAO ; Zongyu MIAO ; Hong WU ; Lei LI ; Xiaoyan LIU ; Yuping WANG ; Lihua JIANG
Chinese Journal of Medical Genetics 2025;42(4):441-445
OBJECTIVE:
To assess the value of chromosomal microarray analysis (CMA) for the detection of low-level mosaicisms in amniotic fluid samples, and to retrospectively analyze the rare cases of mosaicisms.
METHODS:
Chromosomal karyotype of the fetus was determined by G-banding analysis of cultured amniotic fluid cells. CMA was used to detect copy number variation of fetal chromosomes, and fluorescence in situ hybridization (FISH) was used to determine the proportion of fetal chromosomal mosaicisms in uncultured amniotic fluid cells.
RESULTS:
Among 825 prenatal samples, 4 cases of true fetal mosaicisms were detected, which yielded an incidence of 0.48%. Two cases were sex chromosomal mosaicisms, and two were autosomal mosaicisms, which involved chromosomes 8 and 9, respectively. All cases were verified by G-banding analysis of cultured amniotic fluid cells, CMA, and/or FISH.
CONCLUSION
CMA has a great value for detecting low-level mosaicisms in amniotic fluid samples, though the positive results need to be verified by other techniques and should be interpreted with caution. The review of rare cases can provide a basis for prenatal genetic counseling.
Humans
;
Female
;
Amniotic Fluid/metabolism*
;
Pregnancy
;
Mosaicism/embryology*
;
Prenatal Diagnosis/methods*
;
Adult
;
In Situ Hybridization, Fluorescence
;
Microarray Analysis/methods*
;
Karyotyping
;
Retrospective Studies
;
Male
3.Clinical characteristics and genetic analysis of four patients with Disorders of sex development.
Xiuyan WANG ; Fanrong MENG ; Yunfang SHI ; Duan JU ; Xinghong ZHOU ; Haiwei DONG ; Xiaozhou LI
Chinese Journal of Medical Genetics 2025;42(9):1089-1095
OBJECTIVE:
To explore the clinical characteristics and genetic factors in four patients with Disorder of sex development (DSD).
METHODS:
Four patients who visited Tianjin Medical University General Hospital between January 2023 and January 2024, presenting with short stature, abnormal external genitalia, or infertility as their chief complaints, were selected as the study subjects. Clinical data were collected, and peripheral or umbilical cord blood samples were obtained for karyotyping analysis and low-depth whole-genome sequencing (CNV-seq). Quantitative fluorescence PCR (QF-PCR) was used to detect the sex-determining region Y (SRY) gene and azoospermia factor (AZF) on the Y chromosome, while fluorescence in situ hybridization (FISH) was employed to determine the location of the SRY gene. Whole exome sequencing (WES) was performed for genetic testing, and Sanger sequencing was used for familial validation of the candidate variants. The study procedure and protocol were approved by the Medical Ethics Committee of Tianjin Medical University General Hospital (Ethics No.: IRB2024-WZ-006).
RESULTS:
Case 1 had a karyotype of 45,X[22]/46,XY[8], with CNV-seq indicating a mosaic deletion of 7.44 Mb (copy number = 0.2) at Yp11.31-p11.2, a mosaic deletion of 5.32 Mb (copy number = 0.3) at Yq11.1-q11.221, and a deletion of 10.26 Mb (copy number = 0) at Yq11.221-q11.23. Y chromosome microdeletion analysis showed SRY and AZFa (+), AZFb+c (-). Case 2 had a karyotype of 45,X[12]/46,X,del(X)(q26.3)[18], with CNV-seq indicating a mosaic deletion of 132.62 Mb (copy number = 1.4) at Xp22.33-q26.3 and a deletion of 19.62 Mb (copy number = 1) at Xq26.3-q28. Case 3 had a karyotype of 46,XX, with CNV-seq showing two copies of the X chromosome and no Y chromosome. Y chromosome microdeletion analysis showed SRY (+) and AZFa+b+c (-), and FISH confirmed a translocation of the SRY gene to the terminal end of the short arm of the X chromosome. Case 4 had a karyotype of 46,XY, with CNV-seq showing one copy each of the X and Y chromosomes. Y chromosome microdeletion analysis showed SRY(+) and AZFa+b+c (+), and WES revealed a c.1103del variant in the AR gene (maternal origin), which was classified as a pathogenic variant based on the guidelines from the American College of Medical Genetics and Genomics (ACMG) (PVS1+PP1+PM2_Supporting).
CONCLUSION
The combined application of multiple detection techniques such as chromosomal karyotyping analysis, CNV-seq, QF-PCR, and WES can identify the genetic etiology of DSD patients, providing a basis for clinical consultation and treatment plan formulation.
Humans
;
Male
;
Female
;
Chromosomes, Human, Y/genetics*
;
Disorders of Sex Development/genetics*
;
Sex-Determining Region Y Protein/genetics*
;
Karyotyping
;
In Situ Hybridization, Fluorescence
;
Exome Sequencing
;
Adult
;
Child
4.Analysis of false-negative cases by Optical genome mapping and a literature review.
Junrong ZHANG ; Min SU ; Yuquan ZHANG ; Jianlin ZHANG
Chinese Journal of Medical Genetics 2025;42(11):1288-1294
OBJECTIVE:
To explore the reasons for false negative results by Optical genome mapping (OGM) analysis of three cases and propose strategies for handling them.
METHODS:
Three patients presented at the Affiliated Hospital of Nantong University between July 2022 and July 2024 were selected as study subjects. The patients included a 37-year-old female with two miscarriages, a 1.5-year-old boy with delayed motor development, and a 35-year-old male whose son had intellectual disability. The patients had undergone comprehensive evaluation with chromosomal karyotyping analysis, single nucleotide polymorphism microarray (SNP array) assay, fluorescence in situ hybridization (FISH), and methylation-specific multiple ligation-dependent probe amplification (MS-MLPA). A retrospective analysis was also carried out on the results of OGM testing. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: 2020-K004).
RESULTS:
The chromosomal karyotype of patient 1 was 46,XX,4qs, and no abnormality was found by SNP array, FISH, and OGM testing. Patient 2 had a normal chromosomal karyotype, and SNP array analysis did not reveal any copy number abnormalities of chromosomal fragments but the presence of a homozygous region of approximately 79.58 Mb at 15q11.2-q26.3 (chr15: 22817871_102397317). MS-MLPA detection indicated that the copy number of the 15q11.2-q13 region was 2, and the degree of methylation was relatively high (average ratio = 1.0). OGM detection confirmed the presence of approximately 67.97 Mb of homozygosity in the chr15:33814680_101787650 [hg38] region of 15q14-q26.3. Patient 3 had a chromosomal karyotype of 46,XY,t(9;14)(q13;q11.2). No abnormality was found by OGM testing for patients 1 and 3.
CONCLUSION
As a novel cytogenetic technique, OGM can achieve high-resolution and high-precision analysis for numerical and structural genomic abnormalities. Nevertheless, it also has certain limitations, as its false negative results are related to factors such as the type of genomic variation, the chromosomal regions involved in the variation, the type of disease, and the version of human reference genome. Currently, it cannot be used as an independent method for the diagnosis of genetic diseases.
Humans
;
Male
;
Female
;
Adult
;
Polymorphism, Single Nucleotide/genetics*
;
Karyotyping
;
Chromosome Mapping/methods*
;
Infant
;
False Negative Reactions
;
In Situ Hybridization, Fluorescence
5.Genetic analysis of a phenotypically normal male with SRY gene-positive 46,XX/46,XY tetrameric chimerism.
Weiguo ZHANG ; Mengxue WU ; Zhi YANG ; Feiyan PAN ; Zhizhi HE ; Yiyang ZHU
Chinese Journal of Medical Genetics 2025;42(12):1502-1507
OBJECTIVE:
To investigate the clinical characteristics and genetic etiology of a male with a normal phenotype and SRY gene-positive 46,XX/46,XY tetrazoospermia chimerism.
METHODS:
A male patient with an abnormal peripheral blood chromosomal karyotype detected at the Infertility Center of Taizhou Hospital of Zhejiang Province on December 2, 2013 was selected as the study subject. Peripheral venous blood samples were collected from the proband and his family members, together with a semen sample from the proband. Chromosomal karyotype analysis, red blood cell blood group identification, chromosomal microarray analysis (CMA), fluorescence in situ hybridization (FISH), sex-determining region Y (SRY) gene detection, and short tandem repeat (STR) microsatellite marker analysis were performed on the peripheral venous blood sample from the proband. Routine semen analysis, sperm FISH, and STR testing were also conducted. STR verification was performed on both parents. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: k20201009).
RESULTS:
The proband, a 37-year-old male, had normal secondary sexual characteristics and external genitalia development. The chromosomal karyotype of his peripheral blood sample was 46,XX[94]/46,XY[6]. ABO blood group typing was positive for Rh(D) type O and negative for Rh(D) type A, indicating the presence of two red blood cell populations. CMA result was arr[GRCh37](1-22)×2,(XX)×1. Autosomal and X chromosome SNP genotypes were BB-BB, AB-AB, and AA-AA, making it impossible to identify homozygous/heterozygous chimerism. FISH detection of interphase nuclei showed nuc ish XX[92]/XY[8]. Testing of the SRY gene was positive. STR analysis showed a single X peak (no Y peak) at the AMEL locus, 10/12 at the Penta D locus, and no third allele at other loci. Routine semen analysis were normal. Sperm FISH detection showed haploid nuclei nuc ish X[53]/Y[47]. Sperm STR analysis revealed an X/Y bimodal distribution at the AMEL locus and a 9/14 distribution at the Penta D locus, with no third allele observed at other loci. Above results suggested that the proband's blood and germ cell lines had originated from a heterozygous chimera formed by the fusion of two different zygotes.
CONCLUSION
Combined genetic techniques confirmed that the proband's peripheral blood AMEL genotype is X/X, while the sperm is X/Y. The Penta D locus showed a bi-allelic heterozygous pattern of 10/12 in the peripheral blood sample and 9/14 in the sperm sample, suggesting that the proband is a tetrazygotic chimera resulted from the fusion of 46,XX/46,XY zygotes.
Humans
;
Male
;
Adult
;
Chimerism
;
Microsatellite Repeats
;
Sex-Determining Region Y Protein/genetics*
;
Phenotype
;
Genes, sry
;
In Situ Hybridization, Fluorescence
;
Karyotyping
6.Infrared thermography-assisted design and harvesting of ultrathin anterolateral thigh perforator flaps.
Chenxi ZHANG ; Jiadong PAN ; Shanqing YIN ; Guoqing SHAO ; Xianting ZHOU ; Gaoxiang YU ; Luzhe WU ; Xin WANG
Chinese Journal of Reparative and Reconstructive Surgery 2025;39(9):1143-1148
OBJECTIVE:
To explore the application value of infrared thermography in the design and harvesting of ultrathin anterolateral thigh perforator flaps.
METHODS:
Between June 2024 and December 2024, 9 cases of ultrathin anterolateral thigh perforator flaps were designed and harvested with the assistance of infrared thermography. There were 7 males and 2 females, aged 21-61 years (mean, 39.8 years). The body mass index ranged from 19.49 to 26.45 kg/m² (mean, 23.85 kg/m²). Causes of injury included 5 cases of traffic accident injuries and 4 cases of machine crush injuries. There were 3 cases of leg wounds, 2 cases of foot wounds, and 4 cases of hand wounds. After debridement, the size of wound ranged from 7 cm×4 cm to 13 cm×11 cm. The time from admission to flap repair surgery was 5-12 days (mean, 7 days). Preoperatively, perforator localization was performed using a traditional Doppler flow detector and infrared thermography, respectively. The results were compared with the actual intraoperative locations; a discrepancy ≤10 mm was considered as consistent localization (positive), and the positive predictive value was calculated. All 9 cases were repaired with ultrathin anterolateral thigh perforator flaps designed and harvested based on thermographic images. The size of flap ranged from 8 cm×5 cm to 14 cm×8 cm, with a thickness of 3-6 mm (mean, 5.2 mm). One donor site was repaired with a full-thickness skin graft, and the others were sutured directly. Postoperatively, anti-inflammatory, anticoagulant, and anti-vascular spasm treatments were administered, and follow-up was conducted.
RESULTS:
The Doppler flow detector identified 22 perforating vessels within the set range, among which 16 were confirmed as superficial fascia layer perforators intraoperatively, with a positive predictive value of 72.7%. The infrared thermograph detected 23 superficial fascia layer perforating vessels, and 21 were verified intraoperatively, with a positive predictive value of 91.3%. There was no significant difference between the two methods [OR (95%CI)=3.93 (0.70, 22.15), P=0.100]. The perforator localization time of the infrared thermograph was (5.1±1.3) minutes, which was significantly shorter than that of the Doppler flow detector [(10.1±2.6) minutes; MD (95%CI)=-5.00 (-7.08, -2.91), P<0.001]. Postoperatively, 1 case of distal flap necrosis healed after dressing change; all other flaps survived successfully. The skin grafts at donor site survived, and all incisions healed by first intention. All patients were followed up 3-6 months (mean, 4.7 months). No pain or other discomfort occurred at the donor or recipient sites. All patients with foot wounds could walk with shoes, and no secondary flap revision was required. Flaps in 3 hand wound cases, 2 foot wound cases, and 3 leg wound cases recovered light touch and pressure sensation, but not pain or temperature sensation; the remaining 2 cases had no sensory recovery.
CONCLUSION
Preoperative localization using infrared thermography for repairing ultrathin anterolateral thigh perforator flaps can help evaluate the blood supply status of perforators, reduce complications, and improve surgical safety and flap survival rate.
Humans
;
Perforator Flap/blood supply*
;
Adult
;
Male
;
Thermography/methods*
;
Female
;
Thigh/blood supply*
;
Middle Aged
;
Plastic Surgery Procedures/methods*
;
Tissue and Organ Harvesting/methods*
;
Infrared Rays
;
Skin Transplantation/methods*
;
Soft Tissue Injuries/surgery*
;
Young Adult
7.Clinical analysis of nutritional components in children with acute leukemia.
Li-Xia SHI ; Ming-Zhong ZHAO ; Fei-Fei WANG ; Yu-Qian XING ; Hong-Yan JI ; Ping ZHAO
Chinese Journal of Contemporary Pediatrics 2025;27(3):300-307
OBJECTIVES:
To assess the changes in body composition and nutritional risks faced by children with different stages of acute leukemia (AL).
METHODS:
Bioelectrical impedance analysis combined with anthropometric measurements was used to detect body composition. This prospective study was conducted from August 2023 to July 2024 at Shandong Provincial Hospital, examining the body composition and physical balance of children with various stages of AL and healthy children.
RESULTS:
The non-fat components of children with AL and healthy children both showed a linear increase with age. In the younger age group, there were no significant differences in body composition between children with AL and healthy children. However, in the older age group, the body composition of children undergoing chemotherapy for AL was significantly lower than that of healthy children (P<0.05), and muscle mass recovered first after the completion of AL chemotherapy. The proportion of children with increased trunk fat in AL children who completed chemotherapy was significantly lower than that in healthy children (P<0.05), while the incidence rate of severe left-right imbalance in body composition was significantly higher (P<0.05). Muscle distribution in children with AL primarily showed insufficient limb and overall muscle mass, whereas healthy children mainly exhibited insufficient upper limb muscle mass.
CONCLUSIONS
The body composition of children with AL varies at different treatment stages, indicating that nutritional status is affected by both the disease itself and the treatment. Early screening can provide a basis for reasonable nutritional intervention.
Humans
;
Child
;
Male
;
Female
;
Child, Preschool
;
Body Composition
;
Prospective Studies
;
Adolescent
;
Leukemia/metabolism*
;
Infant
;
Nutritional Status
;
Acute Disease
;
Electric Impedance
8.The Clinical Characteristics and Prognosis of Patients with Light-Chain Amyloidosis: A Retrospective Analysis.
Dan ZHAO ; Zeng-Kai WANG ; Ting-Ting CHEN ; Bing-Jie YAO
Journal of Experimental Hematology 2025;33(2):593-600
OBJECTIVE:
To retrospectively analyze the clinical characteristics, prognosis and prognostic factors of patients with light-chain (AL) amyloidosis, so as to provide reference for the diagnosis and treatment of AL amyloidosis.
METHODS:
Clinical data of 52 patients diagnosed with AL amyloidosis at two hospitals from January 2017 to November 2022 were collected. The clinical characteristics, differences in clinical indexes between the deceased group and the survival group were analyzed. Kaplan-Meier curves were used for overall survival (OS) analysis, and Cox regression models were used to analyze the factors affecting the prognosis.
RESULTS:
The median age of the 52 patients at diagnosis was 61(41-81) years old, and 63.5% of the patients were male. Heart (69.2%) and kidney (67.3%) were the most involved organs, and 67.3% of the patients had two or more organs involved. Most patients (71.2%) received chemotherapy regimens containing bortezomib, including 5 patients (9.6%) who received treatment with daratumumab in combination with bortezomib. The proportion of male patients (81.0%), the proportion of patients with cardiac involvement (95.2%), and the proportion of patients with Mayo 2012 stage ≥III (95.2%), as well as the levels of hs-cTnI and NT-proBNP in the deceased group were significantly higher than those in the survival group ( P < 0.05). The median OS time of the enrolled patients was 33.4(2.6-60.2) months, with 1-year, 2-year, 3-year and 5-year OS rates of 83.7%, 79.3%, 58.9% and 32.7%, respectively. The Kaplan-Meier survival curve analysis revealed that patients with male gender (P =0.040), NT-proBNP ≥3 600 ng/L ( P < 0.001), Mayo 2012 stage ≥III ( P < 0.001), and cardiac involvement (P =0.008) had poor prognosis and shorter overall survival (OS) time. The multivariate regression analysis showed that Mayo 2012 stage ≥III was an independent risk factor for prognosis.
CONCLUSION
In recent years, the survival rate of patients with AL amyloidosis has improved significantly, but the 5-year survival rate is still relatively low. Cardiac biomarkers (NT-proBNP and hs-cTnI) and Mayo 2012 stage at diagnosis continue to provide important prognostic information. Bortezomib-based regimens were used as the primary treatment in most patients, and the addition of daratumumab is becoming increasingly common.
Humans
;
Retrospective Studies
;
Prognosis
;
Middle Aged
;
Male
;
Female
;
Aged
;
Immunoglobulin Light-chain Amyloidosis/diagnosis*
;
Adult
;
Aged, 80 and over
;
Kaplan-Meier Estimate
9.Effects of Total Body Irradiation with 60 Co Gamma Ray at Different Dose Rates on Hematopoietic and Immune Cells in Mice.
Hui SHU ; Ya DONG ; Xue-Wen ZHANG ; Xing SHEN ; Shuang XING ; Zu-Yin YU
Journal of Experimental Hematology 2025;33(4):1181-1189
OBJECTIVE:
To investigate the effect of irradiation dose rate of 60Co γ-ray on hematopoietic and immune cells in total body irradiation (TBI) mice.
METHODS:
After TBI with 8 Gy 60Co γ-ray at three irradiation dose rates of 0.027, 0.256 and 0.597 Gy/min, the survival and change of body weight of C57BL/6J mice were observed within 30 days. The peripheral blood parameters were examined at each time point within 30 days post-irradiation. The hematopoietic stem/progenitor cell counts of mice were examined on the 10th and 30th day post-irradiation by flow cytometry, as well as the proportions of immune cells in peripheral blood, bone marrow and spleen of mice on the 30th day post-irradiation.
RESULTS:
After TBI with 8 Gy 60Co γ-ray, the 30-day survival rate of high dose-rate group was 0, which was significantly lower than 90% of medium dose-rate group and 100% of low dose-rate group (both P < 0.001). The peripheral blood parameters of all three groups showed a sharp decline → low value → gradually recovering trend. The count of white blood cell, neutrophil, lymphocyte, red blood cell, platelet and hemoglobin level in the high dose-rate and medium dose-rate groups were significantly lower than those in the low dose-rate group on day 7-18 post-irradiation (all P < 0.05), but there were no significant differences between the high dose-rate and medium dose-rate groups (P >0.05). On the 10th day after irradiation, the proportion and number of bone marrow hematopoietic stem/progenitor cells (including LK, LSK, LT-HSC, ST-HSC, and MPP cells) in the low dose-rate and medium dose-rate groups were significantly decreased compared to those in the normal group (all P < 0.05), but there were no significant differences between the two groups (P >0.05). On the 30th day after irradiation, LSK, LT-HSC, ST-HSC and MPP cells in the low dose-rate group recovered to normal levels, while those in the medium dose-rate group were still significantly lower than those in the low dose-rate group (all P < 0.001). The results of bone marrow and peripheral immune cell tests on the 30th day after irradiation showed that the ratios of T and B lymphocytes in the low dose-rate and medium dose-rate groups were reduced compared to that in the normal group (both P < 0.05), while the ratio of neutrophils was increased (P < 0.01). The trend of changes in the spleen and peripheral blood was consistent.
CONCLUSION
The degree of hematopoietic and immune cell damage in mice after TBI with 8 Gy 60Co γ-ray is related to the dose rate, and low dose-rate irradiation can reduce the damage in the animal model. Therefore, choosing the appropriate dose rate of irradiation is a key factor in establishing an objective and reliable experimental animal model of irradiation.
Animals
;
Mice
;
Whole-Body Irradiation
;
Gamma Rays
;
Mice, Inbred C57BL
;
Hematopoietic Stem Cells/radiation effects*
;
Cobalt Radioisotopes
;
Dose-Response Relationship, Radiation
;
Male
10.Single exposure to near-threshold 5G millimeter wave modifies restraint stress responses in rats.
Akiko MATSUMOTO ; Ikumi ENDO ; Etsuko IJIMA ; Akimasa HIRATA ; Sachiko KODERA ; Masayoshi ICHIBA ; Mikiko TOKIYA ; Takashi HIKAGE ; Hiroshi MASUDA
Environmental Health and Preventive Medicine 2025;30():33-33
BACKGROUND:
In response to growing concerns about the health effects of quasi-millimeter waves (qMMW) used in 5th-generation wireless systems, conservative whole-body exposure thresholds based on indirect evidence have been proposed. The guidelines define a whole-body average specific absorption rate (WBA-SAR) of 4 W/kg which causes a 1 °C increase in core temperature, as the operational threshold for adverse health effects. To address the lack of direct evidence, we recently reported that a 30-minute exposure to qMMW at 4.6 W/kg resulted in a 1 °C increase in rat core temperature. Here, we further analyzed the near-threshold stress response for the first time, using biological samples from the aforementioned and additional experiments.
METHODS:
A total of 59 young Sprague-Dawley rats (240-322 g) were exposed to 28 GHz for 40 minutes at WBA-SARs of 0, 3.7, and 7.2 W/kg, under normal (22.5 °C, 45-55% humidity), and heat (32 °C, 70% humidity) conditions. Rats were restrained in acrylic holders for dose control. We repeatedly measured serum and urinary biomarkers of stress response, aggregated the data, and analyzed them using a single statistical mixed model to subtract the effects of sham exposure and between-subject variation.
RESULTS:
Sham exposure induced stress responses, suggesting an effect of restraint. After the subtraction of the sham exposure effect, 28 GHz appeared to induce stress responses as evidenced by elevated serum-free corticosterone 1 or 3 days after the exposure, which was more evident in animals with a change in rectal temperature exceeding 1 °C. Urinary-free catecholamines demonstrated an inhibitory property of 28 GHz frequency exposure on the stress response as evidenced by noradrenaline on the day of exposure. Heat exposure enhanced this effect, suggesting a possible role of noradrenaline in heat dissipation by promoting cutaneous blood flow, a notion supported by the correlation between noradrenaline levels and tail surface temperature, a critical organ for heat dissipation.
CONCLUSIONS
This study is the first to demonstrate that qMMW whole-body exposure can alter the stress response as indicated by corticosterone and noradrenaline at near-threshold levels. Our findings may provide insight into the biological basis of the whole-body exposure thresholds in the international guidelines.
Animals
;
Rats
;
Rats, Sprague-Dawley
;
Male
;
Restraint, Physical
;
Stress, Physiological/radiation effects*
;
Corticosterone/blood*
;
Biomarkers/blood*
;
Microwaves/adverse effects*

Result Analysis
Print
Save
E-mail