Superficial brachioulnar artery in man

The individual arterial pattern of the upper limb is considerably variable (11-24%) and relevant for intraarterial interventions performed by cardiologists, plastic and vascular surgeons, radiologists, anaesthesiologists, transplant specialists, orthopaedists and neurosurgeons. Arterial variants in the upper limb result from modifications in the maintenance and regression of the initial capillary plexus, which forms dominant arterial channels and gradually expands into the growing upper limb bud between stages 12 and 21. In this case report we present the superficial brachioulnar artery with its external diameter of 3 mm and length of 525 mm, and of relevant course in the left upper limb of a 78-year-old male Caucasian formalin-fixed cadaver. The superficial brachioulnar artery unusually started with the superior part of axillary artery, presented the following five parts: axillary, brachial, cubital, antebrachial and palmar, and was finally continuous with the superficial palmar arch. The typical ulnar artery was somewhat hypoplastic and limited to the forearm. To the best of our knowledge, this is the first report in the professional literature to describe the start of the superficial brachioulnar artery with the superior part of axillary artery. We conclude the individual arterial pattern of the upper limb to be indispensably recognised preoperatively, so as to circumvent any unwanted injuries to the superficial brachioulnar artery that is considerably large, overlies the antebrachial fascia and supplies the superficial palmar arch.

Abstract 299: Large tandem duplications in cancer resulting from transcription and DNA replication collisions

Somatic structural variations (SVs) are common in cancer. Although a small fraction of SVs in breast and ovarian cancers can be attributed to homologous recombination deficiency, the underlying molecular mechanisms for the vast majority of somatic SVs remain unclear. Here, we focus on the roles of transcription and DNA replication collisions in genomic instability in cancer. Such collisions are unavoidable in cells since both transcription and replication use the same DNA as template. We hypothesized that transcription replication collisions (TRCs), if not properly repaired, would lead to collapsed replication forks and result in SVs. To this end, we studied somatic SVs in 5994 high-coverage whole-genome sequenced primary and metastatic tumors from three independent pan-cancer cohorts. A total of 12 conserved SV signatures, representing independent molecular mechanisms, were deconvoluted from these cohorts using non-negative matrix factorization approach. We detected replicated-strand bias, the expected footprint of transcription-replication collision, in large tandem duplications (TDs) across multiple cohorts. This bias was only observed in expressed genes, consistent with TRCs depending on transcription activity. Large TDs were abundant in female-specific (breast, ovarian and uterus), upper gastric-intestinal tract and prostate cancers. They were associated with worse patient survival and TP53 and CDK12 mutations. CDK12 is a cyclin-dependent kinase (CDK) and a key regulator of transcription elongation. Deleting or suppressing CDK12 using CRISPR-Cas9 in prostate cancer cell lines not only increased RNA:DNA hybrids (R-loops), but also promoted TRCs, suggesting a mechanism by which dysregulation of a transcriptional CDK may lead to genomic instability. Finally, using existing large-scale drug screening data, we found that cancer cell lines with abundant large TDs were significantly more sensitive to the WEE1 inhibitor, MK-1775, which we experimentally validated in prostate cancer cells lacking CDK12. In summary, our data suggest that large TDs in cancer form due to impaired TRC repair and can be used as a biomarker for prognosis and treatment.

Citation Format: Yang Yang, Michelle Badura, Patrick O’Leary, Emily Egusa, Troy Robinson, Xiaoming Zhong, Jason Swinderman, Minkyu Kim, Haolong Li, Alan Ashworth, Felix Feng, Jonathan Chou, Lixing Yang. Large tandem duplications in cancer resulting from transcription and DNA replication collisions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 299.

Quantitative anatomy of the growing supraspinatus muscle in the human fetus

BACKGROUND

The supraspinatus muscle, one of the four rotator cuff muscles, initiates abduction of the arm, simultaneously stretching the articular capsule at the glenohumeral joint, and also contributes to exorotation of the arm. In the present study we aimed to evaluate the age-specific normative values for morphometric parameters of the supraspinatus muscle in human fetuses at varying ages and to elaborate their growth models.

MATERIALS AND METHODS

Using anatomical dissection, digital image analysis (NIS Elements AR 3.0) and statistics (Student's t-test, regression analysis), the length, width, circumference and projection surface area of the supraspinatus muscle were measured in 34 human fetuses of both sexes (16 males, 18 females) aged 18-30 weeks of gestation.

RESULTS

Neither sex nor laterality differences were found in numerical data of the supraspinatus muscle. In the supraspinatus muscle its length and projection surface area increased logarithmically, while its width and circumference grew proportionately to gestational age. The following growth models of the supraspinatus muscle were established: y = -71.382 + 30.972 × ln(Age) ± 0.565 for length, y = -2.988 + 0.386 × Age ± 0.168 for greatest width (perpendicular to superior angle of scapula), y = -1.899 + 0.240 × Age ± 0.078 for width perpendicular to the scapular notch, y = -19.7016 + 3.381 × Age ± 2.036 for circumference, and y = -721.769 + 266.141 × ln(Age) ± 6.170 for projection surface area.

CONCLUSIONS

The supraspinatus muscle reveals neither sex nor laterality differences in its size. The supraspinatus muscle grows logarithmically with reference to its length and projection surface area, and proportionately with respect to its width and circumference.

Quantitative study of the primary ossification center of the parietal bone in the human fetus

Detailed morphometric data concentrating on the development of primary ossification centers in human fetuses is critical for the early detection of developmental defects. Thus, an understanding of the growth and development of the parietal bone is crucial in assessing both the normal and pathological development of the calvaria. The size of the parietal primary ossification center in 37 spontaneously aborted human fetuses of both sexes (16 males and 21 females) aged 18-30 weeks was studied by means of CT, digital-image analysis and statistics. The numerical data of the parietal primary ossification center in the human fetus displays neither sex nor laterality differences. With relation to fetal age in weeks, the parietal primary ossification center grew in sagittal diameter according to the quadratic function y = 16.322 + 0.0347 × (age)² ± 1.323 R² = 0.96, in projection surface area according to the cubic function y = 284.1895 + 0.051 × (age)³ ± 0.490, while in both coronal diameter and volume according to the quartic functions: y = 21.746 + 0.000025 × (age)⁴ ± 1.256 and y = 296.984 + 0.001 × (age)⁴, respectively. The obtained morphometric data of the parietal primary ossification center may be considered age-specific references, and so may contribute to the estimation of gestational ages and be useful in the diagnostics of congenital cranial defects.

Quantitative anatomy of primary ossification centres of the lateral and basilar parts of the occipital bone in the human foetus

BACKGROUND

Computed tomography (CT)-based quantitative analysis of primary ossification centres in the cranium has not been carried out to date due to the limited availability of the foetal human material. Detailed morphometric data about the development of primary ossification centres in human foetuses may be useful in the early detection of developmental defects. Understanding the growth and development of the occipital bone is crucial in assessing the normal and pathological development of the cranial base, and the cranium as a whole.

MATERIALS AND METHODS

The study material comprised 37 human foetuses (16 males and 21 females) aged 18-30 weeks of gestation. Using CT, digital image analysis software, three-dimensional reconstruction and statistical methods, the size of the primary ossification centres of the lateral and basilar parts of the occipital bone was evaluated.

RESULTS

The morphometric characteristics of primary ossification centres of the lateral and basilar parts of the occipital bone display neither sex nor laterality differences. These ossification centres grow linearly with respect to their sagittal and transverse diameters, projection surface area and volume.

CONCLUSIONS

The obtained morphometric data of primary ossification centres in the lateral and basilar parts of the occipital bone may be considered as normative for their respective prenatal weeks and may contribute to the estimation of gestational ages and the diagnostics of congenital defects.

DNA damage and eIF4G1 in breast cancer cells reprogram translation for survival and DNA repair mRNAs

The cellular response to DNA damage is mediated through multiple pathways that regulate and coordinate DNA repair, cell cycle arrest, and cell death. We show that the DNA damage response (DDR) induced by ionizing radiation (IR) is coordinated in breast cancer cells by selective mRNA translation mediated by high levels of translation initiation factor eIF4G1 (eukaryotic initiation factor 4γ1). Increased expression of eIF4G1, common in breast cancers, was found to selectively increase translation of mRNAs involved in cell survival and the DDR, preventing autophagy and apoptosis [Survivin, hypoxia inducible factor 1α (HIF1α), X-linked inhibitor of apoptosis (XIAP)], promoting cell cycle arrest [growth arrest and DNA damage protein 45a (GADD45a), protein 53 (p53), ATR-interacting protein (ATRIP), Check point kinase 1 (Chk1)] and DNA repair [p53 binding protein 1 (53BP1), breast cancer associated proteins 1, 2 (BRCA1/2), Poly-ADP ribose polymerase (PARP), replication factor c2-5 (Rfc2-5), ataxia telangiectasia mutated gene 1 (ATM), meiotic recombination protein 11 (MRE-11), and others]. Reduced expression of eIF4G1, but not its homolog eIF4G2, greatly sensitizes cells to DNA damage by IR, induces cell death by both apoptosis and autophagy, and significantly delays resolution of DNA damage foci with little reduction of overall protein synthesis. Although some mRNAs selectively translated by higher levels of eIF4G1 were found to use internal ribosome entry site (IRES)-mediated alternate translation, most do not. The latter group shows significantly reduced dependence on eIF4E for translation, facilitated by an enhanced requirement for eIF4G1. Increased expression of eIF4G1 therefore promotes specialized translation of survival, growth arrest, and DDR mRNAs that are important in cell survival and DNA repair following genotoxic DNA damage.

Radiation-induced CXCL16 release by breast cancer cells attracts effector T cells

Recruitment of effector T cells to inflamed peripheral tissues is regulated by chemokines and their receptors, but the factors regulating recruitment to tumors remain largely undefined. Ionizing radiation (IR) therapy is a common treatment modality for breast and other cancers. Used as a cytocidal agent for proliferating cancer cells, IR in combination with immunotherapy has been shown to promote immune-mediated tumor destruction in preclinical studies. In this study we demonstrate that IR markedly enhanced the secretion by mouse and human breast cancer cells of CXCL16, a chemokine that binds to CXCR6 on Th1 and activated CD8 effector T cells, and plays an important role in their recruitment to sites of inflammation. Using a poorly immunogenic mouse model of breast cancer, we found that irradiation increased the migration of CD8(+)CXCR6(+) activated T cells to tumors in vitro and in vivo. CXCR6-deficient mice showed reduced infiltration of tumors by activated CD8 T cells and impaired tumor regression following treatment with local IR to the tumor and Abs blocking the negative regulator of T cell activation, CTLA-4. These results provide the first evidence that IR can induce the secretion by cancer cells of proinflammatory chemotactic factors that recruit antitumor effector T cells. The ability of IR to convert tumors into "inflamed" peripheral tissues could be exploited to overcome obstacles at the effector phase of the antitumor immune response and improve the therapeutic efficacy of immunotherapy.

Molecular genetic characterisation of frontotemporal dementia on chromosome 3

We have previously localized a locus causing familial nonspecific dementia to the centromeric region of chromosome 3 in a pedigree from the Jutland area of Denmark. This pedigree shows anticipation. Here we present further analysis of these anticipation data which are suggestive of trinucleotide repeat expansion involvement. We also outline our strategies to clone the mutant gene via its putative associated trinucleotide repeat sequence.

Narrowing of the Hailey-Hailey disease gene region on chromosome 3q and identification of one kindred with a deletion in this region

Hailey-Hailey disease is a cutaneous abnormality transmitted as an autosomal dominant trait in which impaired interkeratinocyte adhesion produces recurrent blisters in characteristic skin sites. We report here a confirmation of the initial mapping of the mutant gene to chromosome 3q in an additional seven kindreds, narrowing of the candidate region to the sequences flanked by D3S1589 and D3S1541, and the finding in one family of a genomic DNA deletion whose centromeric end is located between these two flanking markers.