[Pediatric pancreatic lesions: a clinicopathological analysis of 42 cases].

Objective: To investigate the clinicopathological characteristics of pancreatic lesions in children. Methods: The clinicopathological data of pancreatic lesions in children were analyzed including 42 cases of pancreatic tumors diagnosed from January 2000 to May 2021 in Guangzhou Women's and Children's Medical Center, Guangzhou, China. Histological and immunohistochemical assessments were performed. Related literature was reviewed. Results: The 42 pediatric patients with pancreatic lesions aged 1 day to 12 years (mean, 4.25 years). There were 23 males and 19 females. Clinical presentations included abdominal masses, abdominal pain, vomiting and persistent hypoglycemia after birth. Ultrasound and computerized tomography examination showed space-occupying pancreatic lesions in 31 cases, but no detectable pancreatic lesions in 11 cases. Histologically, among the 42 cases, 22 cases (52.4%) were neoplastic, including 18 cases of epithelial origin. Nine cases of pancreatoblastoma showed that the epithelial tumor cells were arranged in a trabecular pattern, with squamous nests. Six cases of solid-pseudopapillary tumors revealed hemorrhagic and necrotic cysts and monomorphic epithelioid cells arranged in solid sheets, nests or pseudopapillae. Two cases of neuroendocrine tumors showed tumor cells arranged in cords or nests; one case had a mitotic count of about 3/10 high power field, and a Ki-67 index of about 5%, which was consistent with G2 neuroendocrine tumor; the other case showed tumor cells with cytological atypia, brisk mitoses, about 25/10 HPF and a Ki-67 index of about 80%, consistent with small-cell type neuroendocrine carcinoma. The case of acinar cell carcinoma showed high cellularity, tumor cells in solid, cord-like or acinar-like arrangement with little stroma, and monotonous tumor cells with single distinct nucleolus. There were 4 cases of mesenchymal tumors, including 3 cases of Kaposi's hemangioendothelioma and 1 case of inflammatory myofibroblastic tumor. Among the 20 cases (47.6%) of non-neoplastic lesions, there were 11 cases of hyperinsulinism with ATP-sensitive potassium channel abnormality (HAPCA). Severn cases of diffuse type HAPCA in which the islets scattered between the pancreatic acinar tissue, enlarged, and prominent nuclei. Three cases of focal type HAPCA showed pancreatic islet hyperplasia in the form of nested nodules (0.6-1.5 cm). One case of atypical type HAPCA had extensive islet hyperplasia in pancreatic tissue, and scattered proliferation of nest-like nodules was noted. There were also 7 cases of pseudocyst and 2 cases of congenital cyst. Immunohistochemically, pancreatoblastomas were diffusely positive for CKpan, CK8/18, and ß-catenin (nuclear staining of squamous nests only). Solid-pseudopapillary tumors expressed CD10, cyclin D1, CD99, vimentin, CD56, and ß-catenin (nuclear staining). Neuroendocrine tumors were positive for CK, Syn, NSE, CgA, CD56, and ß-catenin (membranous staining). The acinar cell carcinoma was positive for CK8/18, trypsin, and ß-catenin (membranous staining). Conclusions: Pancreatic lesions in children have a wide range of histopathological types. HAPCA is the most common lesion of newborns. Pediatric pancreatic tumors are rare and mostly malignant. It is important to recognize them and make correct pathological diagnoses.

[Gonadal neoplastic related lesions in children with disorders of sexual development: a clinicopathological study of twelve cases].

Objective: To investigate the clinicopathological features of gonadal neoplastic related lesions in children with disorders of sexual development (DsD). Methods: The clinical manifestations, chromosomal karyotype, histology and immunophenotype of 12 cases of neoplastic related lesions from Guangzhou Women and Children's Medical Center, Guangzhou were analyzed during Jan 2015 to May 2020. Results: Twelve cases of neoplastic related lesions were screened in 205 cases of DsD, and 6 patients with gonadal germ cell neoplasia aged 3-13 years with an average age of 8.3 years. There were 2 males and 4 females. Clinical features showed malformation of external genitalia in 2 cases, short stature in 2 cases, clitoral enlargement in 1 case, lower abdominal pain and a huge pelvic mass in 1 case. Chromosomal karyotyping of peripheral blood showed 2 cases of 46XY and 4 cases of 45X/46XY. Fourteen gonadal specimens were examined. Microscopically, 1 case showed dysgerminoma in left ovary, and malignant mixed germ cell tumors in right ovary, as well as gonadoblastoma (GB) and undifferentiated gonadal tissue (UGT). The remaining 5 cases were all precursor lesions of germ cell tumor. Six specimens showed GB, 3 of UGT, and 3 specimens showed germ cell neoplasia in situ (GCNIS), one of which was accompanied by intratubular seminoma and 1 was GB with GCNIS. The other 6 patients with DsD were aged from 8 months to 2 years and 5 months, including 5 males and 1 females. Clinical manifestations showed 5 cases of hypospadias and 1 case of bilateral indirect inguinal hernia. Microscopically, 6 cases showed maturation delay of gonocytes in seminiferous tubules. Immunohistochemically, the primordial germ cells/gonocytes expressed OCT3/4, PLAP and c-KIT in the 12 cases. Conclusion: Gonadal neoplasia in children with DsD is mainly precursor lesions of germ cell tumor and improved understanding of these lesions is of great significance.

[Pathologic features on gonadal changes of sexual developmental disorders in children].

Objective: To investigate the pathologic features of gonadal tissues of disorders of sexual development (DSD) in children. Methods: Fifty-three cases of gonadal developmental disorders were collected from July 2015 to August 2017 at Guangzhou Women and Children's Medical Center. Clinical manifestations, karyotypes, sex hormone levels, ultrasound imaging, histology and immunophenotype of gonadal tissues were analyzed. Results: The age of patients ranged from 7 months to 17 years with an average of (50.7 ± 47.1) months. Social genders of the patients included 32 males and 21 females. Forty-eight patients had abnormal sex hormone levels. Clinical presentations included: toward female genitalia in 25 cases, male genitalia tendency in 17 cases and ambiguous external genitalia in 11 cases. Hypospadias was seen in 31 cases and short stature was seen in 8 cases. Chromosomal karyotyping of peripheral blood revealed 23 cases of sex chromosome disorders, 22 cases of 46 XY disorders, of which 3 cases were 5α-reductase deficiency and 8 cases of 46 XX disorders. Ultrasound examination showed cryptorchidism in 30 cases, including 16 cases of unilateral, 14 cases of bilateral and 1 case presenting a huge pelvic tumor. A total of 97 gonadal tissues from 53 cases of DSD were examined, including 9 cases of unilateral and 44 cases of bilateral gonads. Microscopically, 55 gonads (56.7%) showed dysplastic testes including 17 unilateral and 19 bilateral gonads. Fourteen were streak gonads (14.4%) including 8 unilateral and 3 bilateral gonadal tissues. Nine streak gonad with epithelial cord-like structures (9.3%) were found, of which 5 were unilateral and 2 were bilateral lesions. Seven gonads were ovotestis (7.2%), unilateral in 5 cases (the other side of the gonads of ovary in 4 cases, 1 case of dysplastic testes) and bilateral in 1 case. Seven gonads showed follicular-rich ovarian tissue (7.2%). One case showed bilateral dysplastic testes with gonadoblastoma and ectopic adrenal cortex. One case of streak gonad showed epithelial cord-like structures and undifferentiated glandular tissue embedded in malignant mixed germ cell tumors (mixed gonadoblastoma, dysgerminoma, mature teratoma and yolk sac tumor). One case had testicular microlithiasis. Uterus and fallopian tube structures were found in 11 cases. Immunohistochemical stains were performed in 15 cases. D2-40, PLAP and CKIT were expressed in germ cells and Calretinin, WT1 and inhibin were positive in Setoli cells. SALL4 and OCT3/4 were positive in 3 cases. Inhibin highlighted interstitial Leydig cells in 2 cases. GPC3 was positive in yolk sac tumor component. Conclusions: Gonadal dysgenesis presents a broad spectrum of gonadal phenotypes with variable degrees of differentiation. The development of bilateral gonadal tissues has certain variability. Chromosomal karyotypes have no correlation with gonadal phenotypes. Accurate histopathologic diagnosis of gonadal dysgenesis plays an important role in the treatment and prognosis of the patient.

Experimental study on repairing skin defect by tissue-engineered skin substitute compositely constructed by adipose-derived stem cells and fibrin gel.

OBJECTIVE: To study the application value of artificial skin substitute compositely constructed by adipose-derived stem cells and fibrin gel in skin defect. MATERIALS AND METHODS: Adipose-derived stem cells (ADSCs) were obtained from healthy pure green fluorescent protein (GFP) transgenic mice and were proved to have multiple differentiation potentials. They compositely constructed artificial skin substitute in vitro with fibrin gel. 24 SD rats of either gender, with the gestational age of 3-5 weeks, were divided into four groups in the experiment, namely model group (autologous skin flap transplantation), adipose-derived stem cell transplantation group, fibrin gel transplantation group and compound transplantation group, 6 rats for each group. At the skin blood flow (measured by applying laser Doppler rheometer) and survival rate of the flap on 7d and 21d respectively, the materials were transplanted at back skin injury (1 cm×1 cm) to prepare tissue slice for routine HE staining. The conditions of wound healing were observed, and the angiogenesis of flap neovascularization was detected by the immunofluorescent assay. RESULTS: The skin blood flow, the survival rate of flap and density of neovascularization 7d and 21d after transplantation were significantly higher than those of stem cell group, followed by the model group, with the lowest ones in the fibrin gel group. The differences had statistical significance (p<0.05). The wound healing time of compound group was significantly shorter than that of stem cell group, followed by the model group, with the longest one in the fibrin gel group. The differences had statistical significance (p<0.05). CONCLUSIONS: The artificial skin substitute compositely constructed by adipose-derived stem cells and fibrin gel could significantly shorten healing time and improve the survival rate of the flap in skin defect, with better application value.

[Clinicopathologic study of pediatric vascular anomalies: a report of 117 cases].

OBJECTIVE: To study the clinicopathologic features of pediatric vascular anomalies and application of ISSVA classification. METHODS: The clinical features, histopathologic findings and immunohistochemical results were analyzed in 117 cases of pediatric vascular anomalies encountered during the period from May 2014 to May 2015. RESULTS: A total of 117 cases of vascular anomalies were studied. The age of patients ranged from 18 hours after birth to 11 years (mean age =34 months and median age =27 months). There were 73 male patients and 44 female patients, with the male-to-female ratio being 1.7∶1.0. Congenital skin lesions were found in 37 cases (31.6%). The common sites of involvement included head and neck region (46 cases, 39.3%), trunk (28 cases, 23.9%), extremities (14 cases, 12.0%) and internal viscera (31 cases, 26.5%). According to the new ISSVA classification, there were 74 cases of vascular malformations and 43 cases of vascular neoplasms (ratio=1.7∶1.0). The commonest vascular tumor encountered was infantile hemangioma (21 cases, 48.8%), including 17 cases in proliferative phase and 4 cases in involutive phase. Thirteen cases (23.3%) of congenital hemangioma were found, with 8 cases of rapidly involuting congenital hemangioma and 5 cases of non-involutive congenital hemangioma. Three of the congenital hemangioma occurred in liver. There were 5 cases (11.6%) of pyogenic granuloma, 3 cases (7.0%) of tufted angioma and 1 case (2.3%) of Kaposiform hemangioendothelioma. Amongst the 74 cases of vascular malformations encountered, lymphatic malformation was found in 47 cases (63.5%), venous malformation in 15 cases (20.2%), lymphatic-venous malformation in 11 cases (14.9%) and arteriovenous malformation in 1 case (1.4%). All cases of vascular anomalies were all positive for CD31 on immunostaining. Glut1 and CD15 were positive both in proliferative and involutive phases of the 21 cases of infantile hemangioma, while other vascular tumors and vascular malformations were negative. Forty-seven cases of lymphatic malformation and 11 cases of lymphatic-venous malformation showed D2-40 expression. Focal positivity for D2-40 was demonstrated in 3 cases of tufted angioma and 1 case of Kaposiform hemangioendothelioma. CONCLUSIONS: Vascular anomalies affecting infants and children include tumors and malformations. Accurate histopathologic diagnosis and ISSVA classification of the various types of vascular anomalies play an important role in clinical management.

The full length cloning of a novel porcine gene CFL2b and its influence on the MyHC expression.

Porcine CFL2b gene play an important role in the muscle development and myofibrillar formation in pig. To explore whether CFL2b expression affects muscle fiber trait, the porcine CFL2b full-length cDNA was amplified using homology based cDNA cloning and SMART RACE. Then the full length cDNA of porcine CFL2b was inserted into pEGFP-N1 and transfected into C2C12 cells. The cells stably expressing CFL2b were selected by G418. We examined the expression of MyHC 2x, MyHC 2b and MyHC1/slow in C2C12 cells stably expressing CFL2b. The results showed that the level of MyHC 2x and MyHC 2b mRNA were dramatically increased compared with control cells, while the level of MyHC1/slow mRNA is not changed. To identify the transcription events of CFL2b, the porcine CFL2b mRNA was detected by Northern blotting, two transcripts, long transcript (3,012 bp) and short transcript (1,466 bp) were found in porcine skeletal muscles. The nucleotide sequence of CFL2b shares 88.1 and 74.9% homology with the CFL2b gene in human and mouse. The deduced amino acid sequence of CFL2b (166 amino acids) in pig shares 100, 99.1% identity with the CFL2b in human and mouse, respectively. Taken together, our research revealed that porcine CFL2b may be involved in the regulation muscle fiber trait by affecting the expression of MyHC.

Structural and functional relationships of human DNA polymerases.

A continuing theme of our laboratory has been the understanding of human DNA polymerases at the structural level. We have purified DNA polymerases delta, epsilon and alpha from human placenta. Monoclonal antibodies to these polymerases were isolated and used as tools to study their immunochemical relationships. These studies have shown that while DNA polymerases delta, epsilon and alpha are discrete proteins, they must share common structural features by virtue of the ability of several of our monoclonal antibodies to exhibit cross-reactivity. A second approach we have taken is the molecular cloning of human DNA polymerase delta and epsilon. We have cloned the DNA polymerase delta cDNA, and this has allowed us to compare its primary structure to those of human polymerase alpha and other members of this polymerase family. Multiple sequence alignments have revealed that human DNA polymerase delta is also closely related to the herpes virus family of DNA polymerases. In situ hybridization has shown that the human DNA polymerase delta gene is localized to chromosome 19 q13.3-q13.4. In order to further determine the functional regions of the DNA polymerase delta structure we are currently expressing human pol delta in E. coli and baculovirus systems. Other work in our laboratory is directed toward examining the expression of DNA polymerase delta during the cell cycle.