Evaluation of non-clinical toxicity studies of COVID-19 vaccines.

In this study we evaluated the outcomes of non-clinical toxicity studies of various SARS-CoV-2 vaccines produced with different manufacturing technologies, with focus on Repeated Dose Toxicity (RDT) and Developmental and Reproductive Toxicity (DART) studies. We found that RDT and DART studies at doses relevant for human treatment showed no adverse effects while remaining observations were expected findings including local reactogenicity, immune response and macroscopic findings at the injection site. We have also reviewed the European Medicines Agency (EMA) nonclinical assessment reports for market authorization. Regardless of utilized vaccine manufacturing technology EMA assessment of the non-clinical studies consisted most frequently of comments related to study design, species selection and missing data. Sponsors have often submitted platform studies (vaccine studies with the same technology/construct but using other antigens) as supplementary data. Animal model-based toxicity testing has shown rather small effects, which have been never serious adverse effects. The translational value to support clinical development is mainly to inflammatory effects, indicative of the primary action of the vaccines. From a 3R perspective supportive platform technology data consisting of previously executed RDT and DART studies from the same platform technology are encouraged to be implemented in the vaccine assessment process.

A white raven detected by imaging.

The purpose of this case report is to describe a rare case of a patient with a phaeochromocytoma with several cardiovascular complications, which can be attributed to the tumour. Detection of a phaeochromocytoma sometimes needs a 'Sherlock Holmes spirit' or simply time.

Toward a comparative retrospective analysis of rat and rabbit developmental toxicity studies for pharmaceutical compounds.

Based on a proposal made at the ICH Workshop in Tallinn, Estonia (2010), the value of the rabbit embryo-fetal development (EFD) versus the rodent EFD was examined by the HESI DART group. A cross-industry data survey provided anonymised EFD and toxicokinetic data from EFD studies on over 400 marketed and unmarketed drugs (over 800 studies) that were entered by experts at RIVM into US EPA's ToxRefDB style database. The nature and severity of findings at the lowest observed adverse effect level (LOAEL) are being reviewed to quantitate the frequency with which lesser signs of embryo-fetal effects (e.g., delays in ossification, minor changes in frequency of variants) are driving the LOAELs. Interpretation was based on exposure rather than administered dose. This paper provides an update of this ongoing project as discussed during a workshop of the European Teratology Society in Ispra, Italy (2013). This was the first presentation of the initial data set, allowing debate on future directions, to provide a better understanding of the implications of either delaying a rabbit EFD or waiving the need in particular circumstances.

Compound-specific effects of diverse neurodevelopmental toxicants on global gene expression in the neural embryonic stem cell test (ESTn).

Alternative assays for developmental toxicity testing are needed to reduce animal use in regulatory toxicology. The in vitro murine neural embryonic stem cell test (ESTn) was designed as an alternative for neurodevelopmental toxicity testing. The integration of toxicogenomic-based approaches may further increase predictivity as well as provide insight into underlying mechanisms of developmental toxicity. In the present study, we investigated concentration-dependent effects of six mechanistically diverse compounds, acetaldehyde (ACE), carbamazepine (CBZ), flusilazole (FLU), monoethylhexyl phthalate (MEHP), penicillin G (PENG) and phenytoin (PHE), on the transcriptome and neural differentiation in the ESTn. All compounds with the exception of PENG altered ESTn morphology (cytotoxicity and neural differentiation) in a concentration-dependent manner. Compound induced gene expression changes and corresponding enriched gene ontology biological processes (GO-BP) were identified after 24h exposure at equipotent differentiation-inhibiting concentrations of the compounds. Both compound-specific and common gene expression changes were observed between subsets of tested compounds, in terms of significance, magnitude of regulation and functionality. For example, ACE, CBZ and FLU induced robust changes in number of significantly altered genes (≥ 687 genes) as well as a variety of GO-BP, as compared to MEHP, PHE and PENG (≤ 55 genes with no significant changes in GO-BP observed). Genes associated with developmentally related processes (embryonic morphogenesis, neuron differentiation, and Wnt signaling) showed diverse regulation after exposure to ACE, CBZ and FLU. In addition, gene expression and GO-BP enrichment showed concentration dependence, allowing discrimination of non-toxic versus toxic concentrations on the basis of transcriptomics. This information may be used to define adaptive versus toxic responses at the transcriptome level.

An abbreviated protocol for multilineage neural differentiation of murine embryonic stem cells and its perturbation by methyl mercury.

Alternative assays are highly desirable to reduce the extensive experimental animal use in developmental toxicity testing. In the present study, we developed an improved test system for assessing neurodevelopmental toxicity using differentiating embryonic stem cells. We advanced previously established methods by merging, modifying and abbreviating the original 20-day protocol into a more efficient 13-day neural differentiation protocol. Using morphological observation, immunocytochemistry, gene expression and flow cytometry, it was shown predominantly multiple lineages of neuroectodermal cells were formed in our protocol and to a lower extent, endodermal and mesodermal differentiated cell types. This abbreviated protocol should lead to an advanced screening method using morphology in combination with selected differentiation markers aimed at predicting neurodevelopmental toxicity. Finally, the assay was shown to express differential sensitivity to a model developmental neurotoxicant, methyl mercury.

Juxta-articular myxoma of the knee in a 5-year-old boy: a case report and review of the literature (2009: 12b).

Juxta-articular myxoma (JAM) is a relatively rare variant of myxoma that occurs in the vicinity of large joints. It is composed of fibroblast-like cells that produce an excessive amount of glycosaminoglycans rich in hyaluronic acid. The peak incidence is between the 3rd and 5th decades of life. In this report we describe an extremely rare case of JAM in the knee of a 5-year-old child. The clinical presentation, radiological features and histopathologic findings are described, and the relevant literature is reviewed.

Characterization of a chromosome 8-derived minute marker chromosome using microdissection and FISH in a boy with growth retardation.

In a 9-year-old boy referred because of growth retardation, chromosome analysis showed the presence of a minute marker chromosome in 75% of the metaphases examined. The application of microdissection in combination with fluorescence in situ hybridization demonstrated that the marker was derived from the centromere region of chromosome 8, the karyotype being: mos 47,XY,+mar.ish der(8)(D8Z1+)[75]/46,XY[25]. The clinical and cytogenetical findings are compared with cases previously reported in the literature.

Multiparameter flow cytometry as a tool for the detection of micrometastatic tumour cells in the sentinel lymph node procedure of patients with breast cancer.

AIM: To investigate whether multiparameter flow cytometry (MP-FCM) can be used for the detection of micrometastasis in sentinel lymph nodes (SLNs) in breast cancer. METHODS: Formalin fixed, paraffin wax embedded sentinel lymph nodes (n = 238) from 98 patients were analysed. For each lymph node, sections for haematoxylin and eosin (H&E) staining and immunohistochemistry (IHC) for cytokeratin (MNF116) were cut at three levels with a distance of 500 microm. The intervening material was used for MP-FCM. Cells were immunostained with MNF116, followed by an incubation with fluorescein isothiocyanate (FITC) labelled goat antimouse immunoglobulin. DNA was stained using propidium iodide. From each lymph node 100,000 cells were analysed on the flow cytometer. RESULTS: Thirty eight of the 98 patients with breast carcinoma showed evidence of metastatic disease in the SLN by one ore more of the three methods. In 37 of 38 cases where metastatic cells were seen in the routine H&E and/or IHC, more than 1% cytokeratin positive cells were detected by MP-FCM. In 24 patients, metastatic foci were more than 2 mm (macrometastasis) and in 14 these foci were smaller than 2 mm (micrometastasis). In three of these 14 cases, MP-FCM revealed positive SLNs, although this was not seen at first glance in the H&E or IHC sections. After revision of the slides, one of these three remained negative. However, MP-FCM analysis of the cytokeratin positive cells showed an aneuploid DNA peak, which was almost identical to that of the primary breast tumour. Duplicate measurements, done in 41 cases, showed a 99% reproducibility. In five of 14 patients with micrometastasis, one or two metastatic foci were found in the non-SLN. However, in 15 of 24 macrometastases multiple non-SLNs were found to have metastatic tumour. All micrometastases except for the remaining negative one mentioned above showed only diploid tumour cells, despite the fact that their primary tumours contained both diploid and aneuploid tumour cells. In primary tumours with more than 60% aneuploid cells, predominantly aneuploid macrometastasis were found, whereas diploid primary tumours only showed diploid micrometastases or macrometastases in their SLN. Aneuploid SLN macrometastases were associated with non-SLN metastases in five of seven patients, whereas diploid cases showed additional non-SLN metastases in only seven of 16 patients. CONCLUSION: In all cases, MP-FCM was sufficient to detect micrometastatic tumour cells in a large volume of lymph node tissue from SLNs. In some cases it was superior to H&E and IHC staining. Approximately 30% of SLN micrometastases are accompanied by additional non-SLN metastases. The size of the aneuploid fraction (> 60%) in the primary tumour may influence the risk of having both SLN and non-SLN metastases.

Phenotypic variability of the cat eye syndrome. Case report and review of the literature.

We present a male infant with preauricular skin tags and pits, downslanting palpebral fissures, hypertelorism, ectopic anus, hypospadias, and hypoplastic left heart syndrome. The clinical features in our patient show phenotypic overlap with the cat eye syndrome, as illustrated by the review of 105 reported cases. Cytogenetic analysis revealed a supernumerary marker chromosome, which was identified by microdissection and fluorescence in situ hybridization as an isodicentric chromosome 22(pter --> q11.2::q11.2 --> pter). It was proved with probes specific for the cat eye syndrome critical region that this region was present in quadruplicate in the propositus. We conclude that CES is characterized by large phenotypic variability, ranging from near normal to severe malformations, as reflected in the neurodevelopmental outcome. Preauricular skin tags and/or pits are the most consistent features, and suggest the presence of a supernumerary bisatellited marker chromosome 22 derived from duplication of the CES critical region.

Primary large cell neuroendocrine carcinoma of the presacral region.

A 7 cm diameter presacral tumour, not related to the intrapelvic organs, was found in a 51 year old woman. The needle biopsy showed a poorly differentiated large cell carcinoma. The patient died of urosepsis after chemotherapy. Postmortem examination revealed no other primary or metastatic tumour. Histological examination of the presacral tumour showed a large cell carcinoma with a trabecular pattern and strong immunoreactivity for neuroendocrine markers. The tumour was finally classified as a primary large cell neuroendocrine carcinoma of the presacral region.

Acid steatocrit: a reliable screening tool for steatorrhoea.

UNLABELLED: This study compared the acid steatocrit (AS) results of healthy children with those of sick children with and without gastrointestinal involvement. Stool samples of 166 children were investigated, comprising 50 healthy children, 26 asthma patients, and 90 patients with gastrointestinal problems divided into 34 treated cystic fibrosis (CF) patients with exocrine pancreatic insufficiency, 16 untreated coeliac disease (CD) patients and 40 patients with various gastrointestinal problems. The median values (5th-95th percentile) of AS results were 3.3% (0.0-21%) for healthy children, 4.5% (1.8-22.5%) for asthma patients, 24.7% (2.6-68.2%) for treated CF patients with exocrine pancreatic insufficiency, 19.8% (3-77.7%) for untreated CD patients and 5.5% (1.8-29%) for patients with various gastrointestinal diseases. CONCLUSION: The AS results of treated CF patients with exocrine pancreatic insufficiency and untreated CD patients were similar and significantly higher than those of healthy children and asthma patients. AS can be considered to be a reliable tool in screening for steatorrhoea in paediatric patients.

Androgen, estrogen and progesterone receptor expression in the human uterus during the menstrual cycle.

Cyclic changes in steroid receptor expression in endometrial cells are considered a reflection of its differential functions. Besides estrogen and progestogens, androgens have also been suggested to affect the biological function of the female reproductive tract. We investigated the distribution and intensity of immuno-cytochemical estrogen receptor (ER), progesterone receptor (PR) and androgen receptor (AR) staining in the various cell types of human endometrium and myometrium during the different menstrual cycle phases in 30 paraffin-embedded sections.AR expression in endometrial stromal cells decreased gradually from early proliferative till mid secretory phase. In the late secretory phase, AR expression in all cell types distinguished. Staining of epithelial cells was moderate. The disappearance of AR expression before cyclic separation of endometrial tissue may be causally related or just an epiphenomenon. Due to local competition for 5alpha-reduction of testosterone and the excess of progesterone in the secretory phase, the level of dihydrotestosterone (DHT) will be diminished. Hypothetically, if AR synthesis in endometrium would be DHT-dependent, it would explain the lack of AR expression in the late secretory phase.

Improved pre-operative mediastinal staging in non-small-cell lung cancer by serial sectioning and immunohistochemical staining of lymph-node biopsies.

OBJECTIVE: Mediastinal staging of non-small-cell lung carcinoma (NSCLC) by mediastinoscopy suffers from a low sensitivity, leading to a number of patients with unforeseen N2 disease at thoracotomy. This study was undertaken to assess whether pre-operative staging could be improved by serial sectioning and immunohistochemical staining of mediastinoscopy biopsies. METHODS: In 183 consecutive patients with NSCLC, a thoracotomy was performed after a thorough mediastinal staging by computed tomography scan and cervical mediastinoscopy. In 158 patients (88%), a mediastinal node dissection was performed, revealing unforeseen N2 disease in 24 cases (15%). The preserved mediastinoscopy biopsies of these patients were retrospectively serially sectioned and stained with MNF 116. RESULTS: Metastases could be identified in seven cases (30%), reducing unforeseen N2 disease from 15 to 10%. The number of patients who could theoretically benefit from neo-adjuvant therapy would have been increased by at least 10%. CONCLUSIONS: Pre-operative mediastinal staging can be improved considerably by serial sectioning and immunohistochemical staining of mediastinoscopic biopsy specimens.

Paraneoplastic pemphigus as the initial presentation of chronic lymphocytic leukemia.

The case history of a 61-year-old male patient is described, who presented with severe stomatitis, conjunctivitis and leukocytosis. The diagnosis chronic lymphocytic leukemia (CLL) stage A (0) was made, for which no treatment was necessary. Progression of stomatitis and conjunctivitis and erythosquamous skin lesions with bullae and vesiculae formation developed. Under the diagnosis of bullous pemphigoid the patient was treated with corticosteroids. The histologic and immunofluorescence examination of a skin biopsy was compatible with this diagnosis, and antibodies to skin could not be detected in a first serum sample. Pseudomonas was cultured from all lesions, the corticosteroids were stopped and antibiotic treatment was started, without clear effect. Because of progression of skin lesions and debilitation, the patient finally declined all treatment and died five weeks after admission. Post-mortem examination showed enlarged lymphnodes in the cervical, aortal en iliacal areas, with histology confirming the diagnosis of CLL. Indirect immunofluorescence with the second serum sample showed auto-antibodies in high titer directed against the intercellular epithelial substance. Immunoblot studies showed binding with the classic target antigens in paraneoplastic pemphigus. Re-examination of the histologic skin specimen and the result of direct immunofluorescence were in retrospect compatible with the diagnosis of paraneoplastic pemphigus.

De novo translocation (2;18)(q21;q22) in a child with severe epilepsy, developmental delay and mild dysmorphism.

De novo translocation (2;18)(q21;q22) in a patient with severe epilepsy developmental delay and mild dysmorphism: We report on a patient presenting with severe epilepsy, hypotonia, developmental delay, blepharophimosis, low-set ears, camptodactyly and tapering fingers, and cutaneous syndactyly of toes II and III of the right foot. The MRI showed some loss of volume of the white matter and delayed myelination, no other specific anomalies were present. Chromosome analysis revealed a translocation involving chromosomes 2 and 18, which was characterized further by FISH using band-specific probes. The possibility of a submicroscopic deletion is discussed and the patient is compared with patients reported in the literature with either 2q21 or 18q22 deletion.

A novel flow cytometric steroid hormone receptor assay for paraffin-embedded breast carcinomas: an objective quantification of the steroid hormone receptors and direct correlation to ploidy status and proliferative capacity in a single-tube assay.

Semiquantitative estimation of steroid hormone receptors by immunohistochemistry applied to paraffin sections is common practice in surgical pathology. Flow cytometric (FCM) analysis of estrogen receptor (ER) and progesterone receptor (PR) levels provides a faster and more objective quantitative assay. However, a major problem in such FCM analyses of solid tumor samples is the admixture of tumor cells with normal epithelial, stromal, and inflammatory cells. The aim of the underlying study was to investigate the applicability of a recently developed multiparameter flow cytometric methodology for the accurate estimation of the fraction of steroid hormone receptor-positive tumor cells and to explore whether this multiparameter approach allows the detection of specific, clinically relevant subsets of tumors, based on a combination of ploidy level, steroid hormone receptor status, and cell cycle characteristics. For this purpose, samples of 42 breast cancer patients, from which routine immunohistochemistry for ER and PR also was available, were analyzed. From each case, a cell suspension was prepared from the paraffin block by applying a heating and short pepsin digestion step to 50-microm-thick sections. These cell suspensions were double-immunostained for cytokeratin to identify the epithelial cells, and ER or PR, whereas DNA was quantitatively stained with propidium iodide using an optimized protocol. In the entire group of breast tumors, the percentages of ER- and PR-positive cells were registered in the epithelial subfraction, in combination with DNA ploidy and S phase fraction (SPF). A significant correlation was found between the fraction of hormone receptor-positive cells as found by the immunohistochemical and FCM procedures. For ER, a correlation coefficient of r = .87 was found, and for PR r = .62, both P < .0001. It became clear that all the diploid breast tumors had more than 30% tumor cells positive for ER with a SPF lower than 10%, whereas aneuploid tumors contained on average a smaller percentage of steroid hormone receptor-positive cells, and simultaneously an SPF greater than 10%. Our results show that this multiparameter FCM analysis allows an objective and reproducible quantification of the fraction of steroid hormone receptor-positive cells in the relevant epithelial cell compartment in relation to DNA ploidy status and proliferative capacity in a single-tube assay.

Clonality assessment of lymphoproliferative disorders by multiparameter flow cytometry of paraffin-embedded tissue: an additional diagnostic tool in surgical pathology.

A major drawback of immunohistochemical detection of monoclonality in B-cell lymphoproliferative disorders is the lack of contrast between surface-immunoglobulin staining and extracellular immunoglobulin staining. To bypass this drawback, immunophenotyping of single-cell suspensions by flow cytometry is commonly used. Although the expression of immunoglobulin light chain subtype can be quantified rapidly and reliably, the technique is hampered by the requirement of fresh unfixed material. We applied a recently developed technique for the isolation of single cells from formalin-fixed, paraffin-embedded material to measure clonality in B-cell lymphoproliferative disorders (lymphoid tissue (n = 10) and non-Hodgkin's B-cell lymphoma (n = 10). Immunocytochemistry indicated that common cell surface markers as well as the immunoglobulin light chains could be detected in the cell suspensions derived from archival material. In addition, the technique also allowed combined high-resolution DNA flow cytometric analysis. To investigate the effect of formalin fixation on cross-linking of extracellular immunoglobulins to lymphocytes, a double-immunostaining experiment for both light chain immunoglobulins (kappa and lambda) was performed. This experiment showed that this cross-linking was minimal (less than 2%). All cases of reactive lymphoid hyperplasia were DNA diploid and showed a polyclonal expression of immunoglobulin light chains. In contrast, in 9 of 10 non-Hodgkin's B-cell lymphomas, monoclonality was established on the basis of light chain expression, whereas only 6 of 9 cases were conclusive by immunohistochemistry. Four of the 9 cases were DNA aneuploid. One case did not show light chain expression at all by both techniques. However, this case could be classified as malignant by flow cytometric analysis because of the DNA-aneuploid nature of the B-cell subpopulation. The average S-phase fraction (SPF) of the B cells in the reactive lymphoid tissues was 3.5%. The mean SPF values for B cells in DNA-diploid cases of lymphomas was 3.0%, whereas the mean SPF of B cells in DNA-aneuploid cases was 6.1%. The presented technique is superior to immunohistochemistry for the detection of monoclonality in B-cell lymphoproliferative disorders and therefore provides a powerful tool to support the diagnosis of malignant lymphoma in routinely processed archival samples of lymphoid tissues.