Dynamics of somatostatin 4 receptor expression during chronic-stress loading and its potential as a chronic-stress marker.

Chronic stress has been implicated in mental illnesses and depressive behaviors. Somatostatin 4 receptor (SSTR4) has been shown to mediate anxiolytic and depression-like effects. Here, we aimed to explore the potential of SSTR4 as a diagnostic marker for chronic stress in mice. The mice were divided into single stress, chronic restraint stress, and control groups, and Sstr4 mRNA expression in the pituitary, lungs, and thymus, its protein expression in the thymus, were analyzed. Compared to controls, Sstr4 mRNA expression decreased significantly in the pituitary gland of the chronic and single-stress groups (P = 0.0181 and 0.0022, respectively) and lungs of the single-stress group (P = 0.0124), whereas it significantly increased in the thymus of the chronic-stress group (P = 0.0313). Thymic SSTR4 expression did not decrease significantly in stress groups compared to that in the control group (P = 0.0963). These results suggest that SSTR4 expression fluctuates in response to stress. Furthermore, Sstr4 mRNA expression dynamics in each organ differed based on single or chronic restraint stress-loading periods. In conclusion, this study suggests that investigating SSTR4 expression in each organ could allow for its use as a stress marker to estimate the stress-loading period and aid in diagnosing chronic stress.

HISTOULTRASTRUCTURAL FEATURES OF THYMOCYTES DUE TO THE IMPACT OF THE EXPERIMENTAL GENERAL DEHYDRATION OF A MILD DEGREE.

OBJECTIVE: The aim: The objective of the current study was to reveal ultrastructural changes in rats' thymocytes in experimental data in conditions of mild general dehydration. PATIENTS AND METHODS: Materials and methods: The study was conducted on 20 non-linear adult male laboratory rats weighing 150-170 g. Histological and semi-thin slides of the thymus were prepared according to the required guidelines. RESULTS: Results: On average, in the cortical zone of the thymus, there was decreased cellularity by 13.4% (p<0.001), while in the medulla zone this indicator turned out to be unreliable - 5.5% (р=0.19), compared to the indicators in animals of the control group. The study showed that a slight degree of general dehydration of the body causes ultrastructural changes in the thymus and is accompanied by a cell-mediated response of the central link of immunogenesis and results in morphological changes in the thymus, which are atrophic in nature with a typical pattern of remodeling of the organ's microstructure, which corresponds to cellular aging and the associated sign of accelerated involution. CONCLUSION: Conclusions: General dehydration of a mild degree in the experiment is accompanied by a cell-mediated response of the central link of immunogenesis and results in morphological changes in the thymus, which are atrophic in nature with a typical pattern of remodeling of the organ's microstructure, which corresponds to cellular aging and the associated sign of accelerated involution.

Immunological and Histological Studies of Different Concentrations of Rosmarinus officinalis and Thymus vulgaris Extracts on Thymus Gland of Chick Embryos.

Humanity has an ancient history of consuming medicinal plants for prophylaxis. Within hours, and even months, embryonic cells undergo several processes to form an organism. This study aimed to prove the positive or negative effects of using rosemary and thyme extract on the thymus gland and level of IL-10, IgM, and IgG in serum of chick embryos. The immunological effect was measured by histological and immunological studies. A total of 160 fertilized eggs were randomly distributed into 8 groups; on the 0 and 8th day of incubation, all treated groups received a dose of 0.1 mL/egg. On the 14th and 20th days of incubation, the embryos were sacrificed and the samples were collected (serum and thymus gland). The data were analyzed using ANOVA. Simple damage in thymic tissue with a low cell density in the embryos was treated with high concentrations of rosemary and thyme extracts, as well as in the mixed group. A significant decrease in IgM levels in the group treated by a high concentration of thyme. A decrease in IgG levels was found in the group treated with a high concentration of rosemary and in the mixed group, while the group treated with a high concentration of thyme and the mixed group showed decreases on the 14th day. A significant decrease in IL-10 levels was found on the 14th day, followed by an increase on the 20th day. Despite the benefits of rosemary and thyme, inflammation signs appeared on embryos treated with these herbs.

Histogenetic and disease-relevant phenotypes in thymic epithelial tumors (TETs): The potential significance for future TET classification.

Thymic epithelial tumors (TETs) encompass morphologically various subtypes. Thus, it would be meaningful to explore the expression phenotypes that delineate each TET subtype or overarching multiple subtypes. If these profiles are related to thymic physiology, they will improve our biological understanding of TETs and may contribute to the establishment of a more rational TET classification. Against this background, pathologists have attempted to identify histogenetic features in TETs for a long time. As part of this work, our group has reported several TET expression profiles that are histotype-dependent and related to the nature of thymic epithelial cells (TECs). For example, we found that beta5t, a constituent of thymoproteasome unique to cortical TECs, is expressed mainly in type B thymomas, for which the nomenclature of cortical thymoma was once considered. Another example is the discovery that most thymic carcinomas, especially thymic squamous cell carcinomas, exhibit expression profiles similar to tuft cells, a recently discovered special type of medullary TEC. This review outlines the currently reported histogenetic phenotypes of TETs, including those related to thymoma-associated myasthenia gravis, summarizes their genetic signatures, and provides a perspective for the future direction of TET classification.

Association of T cell infiltration and morphological change of thymus gland with the aggravation of pulmonary emphysema in testosterone deficiency.

Chronic obstructive pulmonary disease is an inflammatory lung disease characterized by chronic bronchitis and emphysema. Our previous study revealed that testosterone depletion induced T cell infiltration in the lungs and aggravated pulmonary emphysema in orchiectomized (ORX) mice exposed to porcine pancreatic elastase (PPE). However, the association between T cell infiltration and emphysema remains unclear. The aim of this study was to determine whether thymus and T cells are involved in the exacerbation of PPE-induced emphysema in ORX mice. The weight of thymus gland in ORX mice was significantly greater than that of sham mice. The pretreatment of anti-CD3 antibody suppressed PPE-induced thymic enlargement and T cell infiltration in the lungs in ORX mice, resulting in improved expansion of the alveolar diameter, a marker of emphysema exacerbation. These results suggest that increased thymic function due to testosterone deficiency and the associated increased pulmonary infiltration of T cells may trigger the development of emphysema.

Histological study of the role of CD34+ stem cells and mast cells in cyclophosphamide-induced thymic injury in rats and the possible attenuating role of melatonin.

Cyclophosphamide (CP) is an anticancer drug that adversely affects immunity and thymus structure. Melatonin is a hormone secreted by the pineal gland. It boosts immunity and has antioxidant properties. Therefore, the present study was conducted to investigate the possible protective effect of melatonin on CP-induced changes in the rat thymus. Forty male albino rats were used and divided equally into four main groups. Group I was the control group. Group II (melatonin group) received melatonin at a dose of 10 mg/kg body weight/day by intraperitoneal injection throughout the experimental period. Group III (CP group) received 200 mg/kg body weight CP by a single intraperitoneal injection. Group IV (CP + melatonin group) received melatonin intraperitoneally at a dose of 10 mg/kg body weight/day starting 5 days prior to CP injection until the end of the experiment. All rats were euthanized 7 days after CP injection. Administration of CP in group III resulted in depletion of the cortical thymoblasts. In addition, CD34-immunopositive stained stem cells decreased and mast cell infiltration increased. Electron microscopy showed degeneration of thymoblasts and vacuolization of epithelial reticular cells. Administration of melatonin with CP in group IV showed considerable protection of thymic histology. In conclusion, melatonin may protect against CP-induced thymic injury.

Finding the best method for screening for gestational diabetes mellitus: fetal thymic-thoracic ratio or fetal thymus transverse diameter

SUMMARY OBJECTIVE: The aim of this study was to compare the efficiency of fetal thymic-thoracic ratio and fetal thymus transverse diameter measurements in gestational diabetes mellitus. METHODS: Fetal thymic-thoracic ratio and fetal thymus transverse diameter were assessed in 360 pregnant women. Patients were examined in two groups: 180 gestational diabetes mellitus (study group) and 180 healthy pregnant women (control group). RESULTS: There were no statistically significant differences between the cases with gestational diabetes mellitus and the control group in terms of fetal thymus transverse diameter; however, the fetal thymic-thoracic ratio was found to be significantly lower in cases with gestational diabetes mellitus compared to that in the control group (p<0.001). CONCLUSION: The fetal thymic-thoracic ratio is superior to the fetal thymus transverse diameter in evaluating the fetal thymus size.

Growth hormone enhances the CD34+ stem cells repopulation of the male albino rat thymus gland in cyclophosphamide induced injury: immunohistochemical and electron microscopic study.

Cyclophosphamide (CP) is a chemotherapeutic drug that has a harmful effect on the immune system. Growth hormone (GH) is a peptide hormone that can enhance thymic functions in cases of immunosuppression. Therefore, the present study was performed to study the possible protective effect of growth hormone on cyclophosphamide-induced changes in the rat thymus gland. Sixty-four adult male albino rats were used and divided into three main groups. Group I (Control group). Group II (CP group) received 200 mg/kg body weight CP by a single intra-peritoneal injection. Group III (CP& GH group) received GH in a dose of 2 mg/kg body weight/day by subcutaneous injection starting 5 days before cyclophosphamide injection till the end of the experiment. Administration of CP (Group II) resulted in marked histopathological changes in thymus. Thymic cortex showed depletion of thymoblasts. There was a decrease in CD34 immune positively stained stem cells and an increase in CD68 immune positively stained macrophages. Ultrastructurally, thymoblasts were markedly degenerated and the most of epithelial reticular cells were vacuolated. Administration of GH (group III) showed preservation of the histological structure of the thymus. In conclusion, growth hormone could protect against cyclophosphamide induced thymic damage.

Fetal thymus in growth-restricted fetuses due to placental insufficiency

SUMMARY OBJECTIVE: The aim of this study was to assess fetal thymus size by ultrasound in growth-restricted fetuses due to placental insufficiency and compare to high-risk and low-risk pregnancy fetuses with normal placental function. METHODS: This is a nested case-control study of pregnant women followed up at a university hospital (July 2012 to July 2013). In all, 30 pregnant women presenting small fetuses for gestational age (estimated fetal weight <p10) due to placental insufficiency (umbilical artery Doppler >p95) were compared to 30 high-risk and 30 low-risk pregnancies presenting normal Doppler indices. The thymus transverse diameter and perimeter were converted into zeta score according to the normal values for gestational age. Head circumference and femur length were used to calculate ratios. RESULTS: Fetal thymus were significantly lower in pregnancies with placental insufficiency when compared to high-risk and low-risk pregnancies presenting, respectively, transverse diameter zeta score (-0.69±0.83 vs. 0.49±1.13 vs. 0.83±0.85, p<0.001) and P zeta score (-0.73±0.68 vs. 0.45±0.96 vs. 0.26±0.89, p<0.001). There was also a significant difference (p<0.05) in the ratios among the groups: pregnancies with placental insufficiency (TD/HC=0.10, P/FL=1.32, and P/HC=0.26), high-risk pregnancies (TD/HC=0.11, P/FL=1.40, and P/HC=0.30), and control group (DT/HC=0.11, P/FL=1.45, and P/HC=0.31). CONCLUSION: Fetal thymus size is reduced in growth-restricted fetuses due to placental insufficiency, suggesting fetal response as a consequence of the adverse environment.

Thymus variants on imaging of patients with primary Sjögren's syndrome and polymyositis/dermatomyositis: clinical and immunological significance.

We investigated the presence of radiographic thymus variants using a scoring system and examined their association with clinical and immunological features in primary Sjögren's syndrome (pSS) and polymyositis/dermatomyositis (PM/DM) patients. Cases of 72 patients with pSS and 47 with PM/DM were randomly selected from all visitors to our department who received chest CT scanning, excluding those with thymoma or thymic cyst, or age <30 years. We quantitatively interpreted and assessed thymus size and attenuation score in axial CT images. Thymic enlargement was identified in 16 (22.2%) pSS and 14 (29.8%) PM/DM patients. A thymus attenuation score ≥ 2 was seen in 11 (15.3%) pSS and 9 (19.1%) PM/DM patients. Thymic enlargement showed a significant association with the titre of rheumatoid factor in PM/DM patients. Thymic enlargement and score showed a significant association with body weight in pSS patients. Radiographic thymus variants are often observed in pSS and PM/DM patients, particularly in cases of PM/DM, and may suggest the role of an abnormal immune response in their pathogenesis.

An enlarged fetal thymus may be the initial response to intrauterine inflammation in pregnant women at risk for preterm birth

SUMMARY OBJECTIVE: Fetal thymus involvement in prematurity has been studied, and this study aimed to evaluate its relationship with short cervix and amniotic fluid sludge in the second trimester of pregnancy. METHODS: In this prospective cross-sectional study, 79 pregnant women (19+0 to 24+6 weeks) were included, and cervical length and the presence or absence of amniotic fluid sludge were evaluated. In the three-vessel view of the fetal thorax, the thymus was identified, and its perimeter and transverse diameter were measured and transformed to a zeta score based on gestational age. RESULTS: Data from 22 women with short cervix (<25 mm) and 57 patients with normal cervix (≥25 mm) were analyzed. The transverse diameter of the fetal thymus was significantly greater in the short cervix group compared to that of the normal cervix group (z-score 2.708 vs. −0.043, p=0.003). There were no significant differences in the perimeter (z-score −0.039 vs. −0.071, p=0.890) or the transverse diameter (z-score 1.297 vs. −0.004, p=0.091) of the fetal thymus associated with the presence (n=21) or absence of sludge (n=58). CONCLUSION: A short cervix is associated with an increased transverse diameter of the fetal thymus during the second trimester of gestation.

Characteristics and outcomes of anterior mediastinal cystic lesions diagnosed on chest MRI: implications for management of cystic lesions.

BACKGROUND: Chest MRI is a useful diagnostic modality for the evaluation of anterior mediastinal lesions but the outcomes of anterior mediastinal cystic lesions diagnosed on chest MRI are unclear. METHODS: In this multicenter retrospective study, patients who underwent contrast-enhanced chest MRI in two tertiary centers to assess anterior mediastinal cystic lesions were included after excluding overt solid tumors and thymic hyperplasia. Anterior mediastinal cystic lesions were classified into two categories: probable (simple) cyst or indeterminate lesion (complex cyst). Size and imaging features of lesions during follow-up were evaluated and clinical outcomes were assessed. RESULTS: A total of 204 patients (mean age, 59 ± 11 years; M:F = 111:93) were studied; 186 (91.2%) were classified as probable cysts and 18 (8.8%) as indeterminate lesions on MRI. Among patients with probable cysts and more than 2 years of follow-up, lesion size was unchanged in 39.6% (36/91), decreased in 16.5% (15/91), and fluctuated in 8.8% (8/91). All patients who underwent surgery were confirmed cysts. None developed mural nodules or irregular wall thickening, suspicious for malignancy during follow-up. In patients with indeterminate lesions, 16.7% (3/18) had pathologically confirmed thymoma and 44.4% (8/18) had proven cysts. Follow-up numbers and intervals after MRI in patients with probable cysts were variable among physicians and institutions in clinical practice (p < 0.05) but more than half were followed for up to 2 years in two centers. CONCLUSION: Diagnosing anterior mediastinal cysts using MRI is reliable. MRI-based management of anterior mediastinal lesions may reduce the number of unnecessary follow-ups and surgeries.

Solid Ectopic Cervical Thymus: A Case Report.

The thymus gland is a lymphoid organ normally located in the superior anterior mediastinum. It can rarely present abnormally in other sites along the thymopharyngeal canal and it might cause difficulties in breathing and/or feeding. We present a case report of an ectopic cervical thymus of a 10-month-old male infant who was presented to the hospital with a swelling on the left side of his neck for nine months. Investigations raised suspicion about four differential diagnoses and a total surgical excision for histopathological confirmation was deemed mandatory. It is of great importance to consider ectopic cervical thymus in the differential diagnosis of pediatric neck masses to avoid unnecessary procedures and prevent possible complications.

Preliminary application of the subxiphoid video-assisted thoracoscopic extended thymectomy / 中国基层医药

Objective:To analyze the preliminary effects of subxiphoid video-assisted thoracoscopic extended thymectomy.Methods:We retrospectively analyzed the clinical data of six patients who underwent subxiphoid video-assisted thoracoscopic extended thymectomy in Peking University International Hospital from August 2018 to June 2020.Results:All six patients underwent successful subxiphoid video-assisted thoracoscopic extended thymectomy without conversion to thoracotomy. The rate of R0 resection was 100%. Operative time was (175.50 ± 67.78) minutes, intraoperative blood loss was (40.83 ± 31.37) mL, and postoperative drainage time was (7.17 ± 3.55) days. The total amount of postoperative drainage was (1781.67 ± 1293.53) mL. Postoperative hospital stay was (10.67 ± 6.35) days. The length of hospital stay was (19.67 ± 5.65) days. The Visual Analog Scale score measured after surgery was (2.12 ± 0.48) points. Three patients had grade 1 complications, with an incidence of complications of 50.00%. Grade 3-5 compilations did not occur in any patient. No patient died during the perioperative period.Conclusion:Subxiphoid video-assisted thoracoscopic extended thymectomy is safe and effective and provides a good visual field. The surgical method allows bilateral thoracic surgery, reduces surgical trauma, and has a broad application prospect.

Echographic findings in ectopic intrathyroidal thymic tissue in children. A systematic review.

Intrathyroidal ectopic thymic tissue (IETT) is an indulgent, unusual entity and is part of the differential diagnosis of thyroid nodules in the pediatric population. Because of the low prevalence of IETT, the diagnosis may be difficult. Awareness of this diagnosis is definitive to avoid surgical interventions. The aim of this study was to review the literature on the echographic characteristics of IETT. We conducted a search of Ovid, PubMed and the virtual health library. A total of 619 patients with a mean age of 6.2 years old were included. IETT was located in the lower portion of both of the thyroidal lobes in 556 children, the echographic shape was reported for 173 patients, with the fusiform shape as the most representative, the appearance of the IETTs was reported for 121 patients, the most common was the hypoechogenic pattern with multiple internal echogenic foci. The average lesion diameter was 5.53 mm, and Doppler findings reported a hipovascular pattern in 56% of the lesions. In conclusion, IETT is an infrequent entity; nonetheless, it must be considered in the differential diagnosis of neck nodules in children and should be study and follow with echography to avoid unnecessary surgery.

Proliferation and Directional Differentiation of iNKT Cells Derived from DBA/1 Mice Thymus.

The rates of invariant natural killer T (iNKT) cells in vivo are very low, and the amounts of cells obtained directly from the body are hard enough to fulfill their potential in clinical application. To overcome this problem, we subcutaneously injected alpha-galactosylceramide (α-GalCer) into DBA/1 mice and thymic single cells were isolated and cultured in vitro. Fluorescence-activated cell sorting was used to detect the iNKT cells and their subsets in the thymus after the injection of α-GalCer by different methods. In addition, in vitro changes of single-cell suspensions and their cytokines in culture supernatants were assessed. Compared with the α-GalCer multiple subcutaneous injection group, the rates of iNKT cells in the α-GalCer single subcutaneous injection group were markedly higher at each time point, while the highest levels of iNKT1 and iNKT2 cells were observed on day 4 and  8, respectively. In α-GalCer single subcutaneous injection for 8 days and thymic mononuclear cell cultured for 14 days group, the expansion rate of iNKT cells was significantly faster than the other groups, while it reached a peak for iNKT1 cells. Interferon-gamma was consistent with the development of iNKT1 cells, however no difference was found between the cultured iNKT cells in vitro and the natural iNKT cells in vivo in terms of cytokine production. Herein, we introduced a method in which antigenic stimulation in vivo and directed induction in vitro yielded high levels of iNKT cells with specific functions.

Infection-Associated Thymic Atrophy.

The thymus is a vital organ of the immune system that plays an essential role in thymocyte development and maturation. Thymic atrophy occurs with age (physiological thymic atrophy) or as a result of viral, bacterial, parasitic or fungal infection (pathological thymic atrophy). Thymic atrophy directly results in loss of thymocytes and/or destruction of the thymic architecture, and indirectly leads to a decrease in naïve T cells and limited T cell receptor diversity. Thus, it is important to recognize the causes and mechanisms that induce thymic atrophy. In this review, we highlight current progress in infection-associated pathogenic thymic atrophy and discuss its possible mechanisms. In addition, we discuss whether extracellular vesicles/exosomes could be potential carriers of pathogenic substances to the thymus, and potential drugs for the treatment of thymic atrophy. Having acknowledged that most current research is limited to serological aspects, we look forward to the possibility of extending future work regarding the impact of neural modulation on thymic atrophy.

ALK+ Anaplastic large cell lymphoma with extensive cardiac involvement: A rare case report and review of the literature.

Cardiac lymphoma is a rare entity. In this setting, the secondary involvement of the heart is far more frequent than the primary cardiac lymphoma. Herein, we present an autopsy case of a disseminated anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma with a dominant mediastinal involvement. Extensive cardiac infiltration with the near replacement of the myocardial wall by the neoplastic cells was observed. A total of nine isolated case reports of anaplastic large cell lymphoma with cardiac involvement were found in the English-language literature, and a widespread cardiac and thymic infiltration by the systemic ALK-positive anaplastic large cell lymphoma has not been documented. An incidental regenerative nodule was also identified in the liver. The patient died of pulmonary thromboembolism and cardiac arrest.

Correlation of first-trimester thymus size with chromosomal anomalies.

OBJECTIVES: The aim of this study was to investigate the correlation between fetal thymus size measured during first-trimester screening and chromosomal anomalies. METHODS: This study is a retrospective evaluation, in which the anterior-posterior diameter of the thymus in a midsagittal plane was measured in first-trimester ultrasound between 11+0 and 13+6 weeks of gestation in 168 fetuses with chromosomal anomalies (study group) and 593 healthy fetuses (control group). The included cases were subdivided into six groups: (1) trisomy 21, (2) trisomy 18, (3) trisomy 13, (4) Turner syndrome, (5) triploidy and (6) normal controls. Thymus size measurements were adjusted to the week of gestation, which was determined by ultrasound using crown-rump-length (CRL), by calculating a ratio between CRL and thymus size (CRL-thymus-ratio). Each study group was compared with the control group separately. RESULTS: Thymus size in fetuses affected by trisomy 18 or trisomy 13 was noticeably smaller compared to the control group (1.4 mm [1.3, 1.5] and 1.3 mm [1.2, 1.4] vs. 1.8 mm [1.6, 2.1]; all p<0.001; respectively). The thymus size of fetuses with trisomy 21 and Turner syndrome did not differ from healthy fetuses. Between the CRL-thymus-ratios of the separate study groups no statistically noticeable differences could be found. CONCLUSIONS: Fetal thymus size appeared to be smaller in pregnancies affected by trisomy 18 and trisomy 13. The predictive value of fetal thymus size in first-trimester screening should be evaluated prospectively.

ALK+ Anaplastic large cell lymphoma with extensive cardiac involvement: A rare case report and review of the literature

Cardiac lymphoma is a rare entity. In this setting, the secondary involvement of the heart is far more frequent than the primary cardiac lymphoma. Herein, we present an autopsy case of a disseminated anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma with a dominant mediastinal involvement. Extensive cardiac infiltration with the near replacement of the myocardial wall by the neoplastic cells was observed. A total of nine isolated case reports of anaplastic large cell lymphoma with cardiac involvement were found in the English-language literature, and a widespread cardiac and thymic infiltration by the systemic ALK-positive anaplastic large cell lymphoma has not been documented. An incidental regenerative nodule was also identified in the liver. The patient died of pulmonary thromboembolism and cardiac arrest.