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Coolant-assisted liquid nitrogen (LN) flash freezing of frozen tissues has been widely adopted to preserve tissue morphology for histopathological annotations in mass spectrometry-based spatial proteomics techniques. However, existing coolants pose health risks upon inhalation and are expensive. To overcome this challenge, we present our pilot study by introducing the EtOH-LN workflow, which demonstrates the feasibility of using 95 % ethanol as a safer and easily accessible alternative to existing coolants for LN-based cryoembedding of frozen tissues. Our study reveals that both the EtOH-LN and LN-only cryoembedding workflows exhibit significantly reduced freezing artifacts compared to cryoembedding in cryostat (p < 0.005), while EtOH-LN (SD = 0.56) generates more consistent results compared to LN-only (SD = 1.29). We have modified a previously reported morphology restoration method to incorporate the EtOH-LN workflow, which successfully restored the tissue architecture from freezing artifacts (p < 0.05). Additional studies are required to validate the impact of the EtOH-LN workflow on the molecular profiles of tissues.
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Artefatos , Proteômica , Congelamento , Projetos Piloto , Fluxo de Trabalho , Criopreservação/métodos , Etanol , Espectrometria de Massas , NitrogênioRESUMO
The general notion of complete hydatidiform moles is that most of them consist entirely of paternal DNA; hence, they do not express p57, a paternally imprinted gene. This forms the basis for the diagnosis of hydatidiform moles. There are about 38 paternally imprinted genes. The aim of this study is to determine whether other paternally imprinted genes could also assist in the diagnostic approach of hydatidiform moles. This study comprised of 29 complete moles, 15 partial moles and 17 non-molar abortuses. Immunohistochemical study using the antibodies of paternal-imprinted (RB1, TSSC3 and DOG1) and maternal-imprinted (DNMT1 and GATA3) genes were performed. The antibodies' immunoreactivity was evaluated on various placental cell types, namely cytotrophoblasts, syncytiotrophoblasts, villous stromal cells, extravillous intermediate trophoblasts and decidual cells. TSSC3 and RB1 expression were observed in all cases of partial moles and non-molar abortuses. In contrast, their expression in complete moles was identified in 31% (TSSC3) and 10.3% (RB1), respectively (p < 0.0001). DOG1 was consistently negative in all cell types in all cases. The expressions of maternally imprinted genes were seen in all cases, except for one case of complete mole where GATA3 was negative. Both TSSC3 and RB1 could serve as a useful adjunct to p57 for the discrimination of complete moles from partial moles and non-molar abortuses, especially in laboratories that lack comprehensive molecular service and in cases where p57 staining is equivocal.
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Mola Hidatiforme , Toupeiras , Animais , Feminino , Humanos , Gravidez , Anticorpos/metabolismo , Inibidor de Quinase Dependente de Ciclina p57/genética , Inibidor de Quinase Dependente de Ciclina p57/metabolismo , Mola Hidatiforme/diagnóstico , Mola Hidatiforme/genética , Imuno-Histoquímica , Toupeiras/metabolismo , Placenta/metabolismo , Proteínas de Ligação a Retinoblastoma/metabolismo , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Aldosterone-producing adenomas (APAs) are the commonest curable cause of hypertension. Most have gain-of-function somatic mutations of ion channels or transporters. Herein we report the discovery, replication and phenotype of mutations in the neuronal cell adhesion gene CADM1. Independent whole exome sequencing of 40 and 81 APAs found intramembranous p.Val380Asp or p.Gly379Asp variants in two patients whose hypertension and periodic primary aldosteronism were cured by adrenalectomy. Replication identified two more APAs with each variant (total, n = 6). The most upregulated gene (10- to 25-fold) in human adrenocortical H295R cells transduced with the mutations (compared to wildtype) was CYP11B2 (aldosterone synthase), and biological rhythms were the most differentially expressed process. CADM1 knockdown or mutation inhibited gap junction (GJ)-permeable dye transfer. GJ blockade by Gap27 increased CYP11B2 similarly to CADM1 mutation. Human adrenal zona glomerulosa (ZG) expression of GJA1 (the main GJ protein) was patchy, and annular GJs (sequelae of GJ communication) were less prominent in CYP11B2-positive micronodules than adjacent ZG. Somatic mutations of CADM1 cause reversible hypertension and reveal a role for GJ communication in suppressing physiological aldosterone production.
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Neoplasias do Córtex Suprarrenal , Adenoma Adrenocortical , Hiperaldosteronismo , Hipertensão , Humanos , Aldosterona , Citocromo P-450 CYP11B2 , Junções Comunicantes , Mutação , Molécula 1 de Adesão CelularRESUMO
The association between maternal COVID-19 infection, placental histomorphology and perinatal outcomes is uncertain. The published studies on how placental structure is affected after SARS-CoV-2 virus in COVID-19-infected pregnant women are lacking. We investigated the effects of maternal SARS-CoV-2 infection on placental histomorphology and pregnancy outcomes. A retrospective cohort study on 47 pregnant women with confirmed SARS-CoV-2 infection, matched with non-infected controls, was conducted. Relevant clinicopathological data and primary birth outcomes were recorded. Histomorphology and SARS-CoV-2 immunohistochemistry analyses of placental tissues were performed. Only 1 of 47 cases showed SARS-CoV-2 immunoreactivity in the syncytiotrophoblasts. Histologically, decidual vasculopathy (n = 22/47, p = 0.004), maternal vascular thrombosis (n = 9/47, p = 0.015) and chronic histiocytic intervillositis (n = 10/47, p = 0.027) were significantly higher in the COVID-19-infected placentas when compared to the control group. Maternal vascular thrombosis was a significant feature in the active COVID-19 group. A significant lower gestational age (p < 0.001)) at delivery and a higher caesarean section rate (p = 0.007) were observed in the active SARS-CoV-2-infected cases, resulting in a significant lower fetal-placental weight ratio (p = 0.022) and poorer Apgar score (p < 0.001). Notably, active (p = 0.027), symptomatic (p = 0.039), severe-critical (p = 0.002) maternal COVID-19 infection and placental inflammation (p = 0.011) were associated with an increased risk of preterm delivery. Altered placental villous maturation and severe-critical maternal COVID-19 infection were associated with an elevated risk of poor Apgar scores at birth (p = 0.018) and maternal mortality (p = 0.023), respectively.
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COVID-19 , Complicações Infecciosas na Gravidez , Cesárea , Feminino , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas , Placenta , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Resultado da Gravidez/epidemiologia , Estudos Retrospectivos , SARS-CoV-2 , Índice de Gravidade de DoençaRESUMO
Introduction: Cyclophilin A was reported to be increased in the serum of mothers with preeclampsia, and is implicated in its pathogenesis. This study aimed to determine the expression of cyclophilin A in the placenta of mothers with and without hypertension, and to correlate its expression with maternal complications and adverse perinatal outcomes. Materials and Methods: This study consisted of a total of 70 cases (35 cases of mothers with hypertension, and 35 normotensive mothers as a control). Cyclophilin A immunohistochemistry was performed on a paraffin-embedded tissue section of placenta submitted at full thickness in order to evaluate the expression in fetal endothelial cells, cytotrophoblasts, syncytiotrophoblasts, maternal endothelial cells and decidual cells. The cyclophilin A expression was scored as weak, moderate or strong intensity. Results: The hypertensive group was more likely to have preterm deliveries (p < 0.0001), caesarean sections (p < 0.0001), and infants admitted to the intensive care unit (p < 0.001). Fifty-one percent of the fetal endothelial cells and cytotrophoblasts expressed cyclophilin A in the hypertensive group, compared to only 28.6% in the normotensive group. However, the difference was not statistically significant (p = 0.086). Conclusion: We found no significant difference in placental cyclophilin A expression between hypertensive and normotensive mothers. There was also no difference in expression in mothers with and without maternal complications and adverse perinatal outcomes.
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Hipertensão , Pré-Eclâmpsia , Ciclofilina A/metabolismo , Células Endoteliais , Feminino , Humanos , Hipertensão/metabolismo , Recém-Nascido , Placenta/metabolismo , GravidezRESUMO
Background: Chorioamnionitis complicates about 1−5% of deliveries at term and causes about one-third of stillbirths. CXC-chemokine receptor 1 (CXCR1) binds IL-8 with high affinity and regulates neutrophil recruitment. We aimed to determine the immunoexpression of CXCR1 in placentas with chorioamnionitis, and its association with adverse perinatal outcomes. Methods: A total of 101 cases of chorioamnionitis and 32 cases of non-chorioamnionitis were recruited over a period of 2 years. CXCR1 immunohistochemistry was performed, and its immunoexpression in placentas was evaluated. The adverse perinatal outcomes included intrauterine death, poor APGAR score, early neonatal death, and respiratory complications. Results: Seventeen cases (17/101, 16.8%) with chorioamnionitis presented as preterm deliveries. Lung complications were more common in mothers who were >35 years (p = 0.003) and with a higher stage in the foetal inflammatory response (p = 0.03). Notably, 24 cases (23.8%) of histological chorioamnionitis were not detected clinically. Interestingly, the loss of CXCR1 immunoexpression in the umbilical cord endothelial cells (UCECs) was significantly associated with foetal death (p = 0.009). Conclusion: The loss of CXCR1 expression in UCECs was significantly associated with an increased risk of adverse perinatal outcomes and could be used as a biomarker to predict adverse perinatal outcomes in chorioamnionitis. Further study is warranted to study the pathophysiology involved in the failure of CXCR1 expression in these cells.
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Treatment for non-alcoholic fatty liver disease (NAFLD) currently consists of lifestyle modifications such as a low-fat diet, weight loss, and exercise. The gut microbiota forms part of the gut-liver axis and serves as a potential target for NAFLD treatment. We investigated the effect of probiotics on hepatic steatosis, fibrosis, and biochemical blood tests in patients with NAFLD. At the small intestinal mucosal level, we examined the effect of probiotics on the expression of CD4+ and CD8+ T lymphocytes, as well as the tight junction protein zona occluden-1 (ZO-1). This was a randomized, double-blind, placebo-controlled trial involving ultrasound-diagnosed NAFLD patients (n = 39) who were supplemented with either a probiotics sachet (MCP® BCMC® strains) or a placebo for a total of 6 months. Multi-strain probiotics (MCP® BCMC® strains) containing six different Lactobacillus and Bifidobacterium species at a concentration of 30 billion CFU were used. There were no significant changes at the end of the study in terms of hepatic steatosis (probiotics: -21.70 ± 42.6 dB/m, p = 0.052 vs. placebo: -10.72 ± 46.6 dB/m, p = 0.29) and fibrosis levels (probiotics: -0.25 ± 1.77 kPa, p = 0.55 vs. placebo: -0.62 ± 2.37 kPa, p = 0.23) as measured by transient elastography. Likewise, no significant changes were found for both groups for the following parameters: LiverFAST analysis (steatosis, fibrosis and inflammation scores), alanine aminotransferase, total cholesterol, triglycerides, and fasting glucose. In the immunohistochemistry (IHC) analysis, no significant expression changes were seen for CD4+ T lymphocytes in either group (probiotics: -0.33 ± 1.67, p = 0.35 vs. placebo: 0.35 ± 3.25, p = 0.63). However, significant reductions in the expression of CD8+ T lymphocytes (-7.0 ± 13.73, p = 0.04) and ZO-1 (Z-score = -2.86, p = 0.04) were found in the placebo group, but no significant changes in the probiotics group. In this pilot study, the use of probiotics did not result in any significant clinical improvement in NAFLD patients. However, at the microenvironment level (i.e., the small intestinal mucosa), probiotics seemed to be able to stabilize the mucosal immune function and to protect NAFLD patients against increased intestinal permeability. Therefore, probiotics might have a complementary role in treating NAFLD. Further studies with larger sample sizes, a longer duration, and different probiotic strains are needed to evaluate the real benefit of probiotics in NAFLD.
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Bifidobacterium , Mucosa Intestinal , Intestino Delgado , Lactobacillus , Fígado/patologia , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Probióticos/uso terapêutico , Adulto , Idoso , Linfócitos T CD8-Positivos/metabolismo , Método Duplo-Cego , Disbiose/tratamento farmacológico , Técnicas de Imagem por Elasticidade , Feminino , Microbioma Gastrointestinal , Humanos , Imunidade , Inflamação , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Intestino Delgado/imunologia , Intestino Delgado/patologia , Fígado/metabolismo , Cirrose Hepática , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/metabolismo , Permeabilidade , Projetos Piloto , Resultado do TratamentoRESUMO
OBJECTIVES: To determine the significance of tumour PTEN protein expression in endometrioid endometrial carcinoma (EEC) and it is correlation with tumour characteristics. METHODS: A total of 30 eligible archived paraffin-embedded tissue blocks from 61 EEC cases (January 2015-December 2017) were retrieved from the Histopathology Laboratory in Universiti Kebangsaan Malaysia Medical Centre (UKMMC) following institutional ethic approval. For PTEN protein detection, immunohistochemistry (IHC) staining was performed and the data was correlated with clinicopathologic parameters. RESULTS: Fourteen samples (46.7%) showed positive PTEN protein expression, while 16 (53.3%) were negative. The mean age was 62.00 ± 9.51 years old, while the mean Body Mass Index (BMI) was 27.28 ± 7.16 kg/m2. There was no significant difference between age (p=0.27, 95% CI: -10.98 to 3.21) and BMI (p=0.67, 95% CI: -4.30 to 6.58) with PTEN protein expression. There were significant correlation between PTEN protein expression with myometrial invasion (p=0.010), but not with lymphovascular space invasion (p=0.743), grade (p=0.532), stage (p=0.733) and CA-125 level (p=0.47). The higher stage correlates with the presence of LVSI (p=0.002). PTEN positive associated with longer disease-free-interval (p=0.025), but not improving the overall survival (p=0.38). CONCLUSIONS: Positive PTEN protein expression correlates with less myometrial invasion.
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Biomarcadores Tumorais , Neoplasias do Endométrio/metabolismo , Neoplasias do Endométrio/mortalidade , PTEN Fosfo-Hidrolase/metabolismo , Idoso , Neoplasias do Endométrio/diagnóstico , Neoplasias do Endométrio/genética , Feminino , Expressão Gênica , Humanos , Imuno-Histoquímica , Malásia , Pessoa de Meia-Idade , PTEN Fosfo-Hidrolase/genética , PrognósticoRESUMO
Endometrial carcinoma is the only gynaecologic malignancy with a raising incidence and mortality, posing a major health concern worldwide. The upregulation of programmed death ligand 1 (PD-L1) on tumour cells causes T-cell suppression, which impedes antitumour immunity, promotes immune cell evasion and enhances tumour survival. The aim of this study was to evaluate PD-L1 expression in endometrial carcinoma and to correlate it with survival rate. A total of 59 cases of endometrial carcinoma were evaluated. Thirty-two cases of non-neoplastic endometrial tissue were included as control. PD-L1 immunohistochemistry was performed on all cases. PD-L1 expression was evaluated on tumour cells and immune cells. PD-L1 was positive in 62.7% (37/59) and 28.8% (17/59) of immune cells and tumour cells, respectively. PD-L1 expression in immune cells was significantly higher in endometrial carcinoma than in non-neoplastic endometrium (p < 0.001). Among the patients with endometrial carcinoma, PD-L1 expression in tumour cells was significantly higher in patients who died (10/15, 66.7%) compared to those who survived (7/44, 15.9%) (p < 0.001). It is noteworthy to point out that the expression of PD-L1 in tumour cells was significantly associated with a poor survival. This suggests that immunomodulation using PD-L1 inhibitors may be useful in advanced endometrial carcinoma.
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Aim: Chemoresistance in colorectal cancer (CRC) has become a burden in treating the disease effectively. Circular RNAs (circRNAs) are a type of noncoding RNA that were found to be important in cellular homeostasis. The involvement of circRNAs in relation to chemoresistance in other types of cancers has also been reported. This study aims to identify the differentially expressed circRNAs between chemoresistant and chemosensitive CRC cells. Materials & methods: We developed a chemoresistant cell line model and profiled the circRNAs via microarray. We further validated the expression of two circRNAs in 25 formalin-fixed paraffin-embedded (FFPE) tissue specimens (13 nonresponders and 12 responders) via quantitative polymerase chain reaction (qPCR). Results & conclusion: We found that there were 773 upregulated and 732 downregulated circRNAs between the chemoresistant and chemosensitive HCT-116 cells. We found that hsa_circ_32883 could be a promising biotarget.
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Antineoplásicos/farmacologia , Neoplasias do Colo/genética , Neoplasias Colorretais/genética , MicroRNAs/genética , Oxaliplatina/farmacologia , RNA Circular/genética , RNA não Traduzido/genética , Linhagem Celular Tumoral , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Regulação para CimaRESUMO
Colorectal cancer is the third commonest malignancy in Asia including Malaysia. The immunogenic cancer-testis antigens, which are expressed in a variety of cancers but with limited expression in normal tissues except the testis, represent an attractive approach to improve treatment options for colorectal cancer. We aimed to validate four PASD1 peptides as the immunotherapeutic targets in colorectal cancer. First, PASD1 mRNA and protein expression were determined via real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. The PASD1 peptides specific to HLA-A*24:02 were investigated using IFN-y-ELISpot assay, followed by the cytolytic and granzyme-B-ELISpot assays to analyze the cytolytic effects of CD8+ T cells. Gene and protein expressions of PASD1 were detected in 20% and 17.3% of colorectal cancer samples, respectively. PASD1(4) peptide was shown to be immunogenic in colorectal cancer samples. CD8+ T cells raised against PASD1(4) peptide were able to lyze HLA-A*24:02+ PASD1+ cells. Our results reveal that PASD1(4) peptide represents a potential target for colorectal cancer.
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Antígenos de Neoplasias , Antígenos Nucleares , Neoplasias Colorretais , Antígeno HLA-A24/imunologia , Imunoterapia , Proteínas de Neoplasias , Peptídeos , Antígenos de Neoplasias/química , Antígenos de Neoplasias/imunologia , Antígenos de Neoplasias/farmacologia , Antígenos Nucleares/química , Antígenos Nucleares/imunologia , Antígenos Nucleares/farmacologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/patologia , Neoplasias Colorretais/terapia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/imunologia , Células HCT116 , Humanos , Imunidade Celular/efeitos dos fármacos , Masculino , Proteínas de Neoplasias/química , Proteínas de Neoplasias/imunologia , Proteínas de Neoplasias/farmacologia , Peptídeos/química , Peptídeos/imunologia , Peptídeos/farmacologiaRESUMO
Studies on excised adrenals from primary aldosteronism patients have found that somatic mutations in KCNJ5 frequently cause excess aldosterone production in the culprit aldosterone-producing adenoma (APA). KCNJ5 mutant APAs were reported to be peculiarly overrepresented among young females and in Oriental cohorts, compared to their older male, or Caucasian counterparts. These larger APAs were also reported to have similarities with the zona fasciculata (ZF) in the adrenal both from the steroid production profile and the morphology of the cell. We therefore aimed to corroborate these findings by characterizing the APAs from a multi-ethnic Malaysian cohort. The prevalence of KCNJ5 mutations was estimated through targeted DNA sequencing of KCNJ5 in 54 APAs. Confirmation of APA sample acquisition was performed by CYP11B2 immunohistochemistry (IHC) staining. The ZF steroid production profile was based on the ZF enzyme CYP17A1 IHC staining, and ZF cell morphology was based on a high cytoplasm to nucleus ratio. Seventeen (31.5%) APAs studied, harbored a KCNJ5 mutation. No female over-representation was seen in this cohort though females were found to have a higher expression of CYP11B2 than males (p = 0.009; Mann-Whitney U test). Age at adrenalectomy correlated negatively with the percentage of ZF-like cells in the APA (p = 0.01; Spearman's rho) but not with the KCNJ5 genotype. KCNJ5 mutant APAs had a high percentage of ZF-like cells (and high CYP17A1 expression) but so did the wild-type APAs. In summary, prevalence of KCNJ5 mutant APAs in this cohort was similar to other Caucasian cohorts, however, over-representation of females did not occur, which is similar to some studies in Oriental cohorts.
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BACKGROUND: Lung cancer is the third most common cancer worldwide. With major advances in the molecular testing of lung cancers and the introduction of targeted therapies, the distinction between adenocarcinoma and squamous cell carcinoma as well as pathologic subtyping has become important. Recent studies showed that p40 is highly specific for squamous and basal cells and is superior to p63 for diagnosing lung squamous cell carcinoma. The aim of this study was to evaluate the use of p40 immunohistochemical stain in the diagnosis of non-small cell lung carcinoma and its potential to replace current p63 antibody as the best immunohistochemical squamous marker. METHODS: Seventy formalin-fixed paraffin-embedded cases previously diagnosed as primary lung squamous cell carcinoma (n = 35) and lung adenocarcinoma (n = 35) from January 2008 to December 2016 were retrieved. The results of tumour cell immunoreactivity for p40 and p63 antibodies in lung squamous cell carcinoma and lung adenocarcinoma were compared. RESULTS: p40 was expressed in 27 cases of lung squamous cell carcinoma (77.1%). All cases of lung adenocarcinoma (35/35, 100%) were negative for p40. p63 expression was positive in 30 cases of lung squamous cell carcinoma (85.7%) and 13 cases of lung adenocarcinoma (37.1%). Reactivity for both p40 and p63 in lung squamous cell carcinoma was strong and diffuse, whereas variable reactivity was observed in lung adenocarcinoma. CONCLUSIONS: p40 is an excellent marker for distinguishing lung squamous cell carcinoma from adenocarcinoma, and p40 expression is equivalent to p63 expression in lung squamous cell carcinoma.
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Umbilical cord (UC) is a discarded product from the operating theatre and a ready source of mesenchymal stromal cells (MSCs). MSCs from UC express both embryonic and adult mesenchymal stem cell markers and are known to be hypoimmunogenic and non-tumorigenic and thus suitable for allogeneic cell transplantation. Our study aimed to determine the degree of immunotolerance and bone-forming capacity of osteodifferentiated human Wharton's jelly-derived mesenchymal stromal cells (hWJ-MSCs) from different segments of UC in an allogenic setting. UCs were obtained from healthy donors delivering a full-term infant by elective Caesarean section. hWJ-MSCs were isolated from 3 cm length segment from the maternal and foetal ends of UCs. Three-dimensional fibrin constructs were formed and implanted intramuscularly into immunocompetent mice. The mice were implanted with 1) fibrin construct with maternal hWJ-MSCs, 2) fibrin construct with foetal hWJ-MSCs, or 3) fibrin without cells; the control group received sham surgery. After 1 month, the lymphoid organs were analysed to determine the degree of immune rejection and bone constructs were analysed to determine the amount of bone formed. A pronounced immune reaction was noted in the fibrin group. The maternal segment constructs demonstrated greater osteogenesis than the foetal segment constructs. Both maternal and foetal segment constructs caused minimal immune reaction and thus appear to be safe for allogeneic bone transplant. The suppression of inflammation may be a result of increased anti-inflammatory cytokine production mediated by the hWJ-MSC. In summary, this study demonstrates the feasibility of using bone constructs derived from hWJ-MSCs in an allogenic setting.
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Aim: Abnormal expression patterns of beta-tubulin isotypes may provide a molecular rationale for the behaviour of lymphoma subtypes. In the present study class II and III beta-tubulin expression was assessed in non-neoplastic and neoplastic lymphoid tissues with reference to potential utility as new tumour biomarkers. Methods and results: In this cross-sectional study class II and III beta-tubulin expression was assessed in 304 neoplastic and 20 normal lymphoid tissues using qualitative and semi-quantitative immunohistochemistry. Class II beta-tubulin was found to be positive in the germinal centres, mantle zone and interfollicular regions of normal lymphoid tissues. It was also expressed in 15/15 (100%) lymphoblastic lymphomas, 229/231 (99%) mature B cell lymphomas, 22/22 (100%) T/NK-cell lymphomas and 36/36(100%) classical Hodgkin lymphomas. Class III beta-tubulin in contrast was germinal centre restricted and more selective, being found mainly in classical Hodgkin lymphomas (34/36 (94%)). It was also expressed in 58/171(34%) DLBCL, 11/12 (92%) mantle cell lymphomas and 6/6 (100%) Burkitt lymphomas. Other mature B cell, T/NK cell lymphomas and precursor lymphoblastic lymphomas were usually negative. Conclusions: Class II beta-tubulin shows ubiquitous expression in neoplastic and non-neoplastic lymphoisd tissues. In contrast, Class III beta-tubulin is germinal centre-restricted. Its consistent expression in classical Hodgkin lymphomas may point to use in the identification of Reed-Sternberg and Hodgkin cells. Its expression in a proportion of DLBCL, Burkitt and mantle cell lymphomas is of interest as this may be related to their aggressiveness.