First Measurement of the Nuclear-Recoil Ionization Yield in Silicon at 100 eV

We measured the nuclear-recoil ionization yield in silicon with a cryogenic phonon-sensitive gram-scale detector. Neutrons from a monoenergetic beam scatter off of the silicon nuclei at angles corresponding to energy depositions from 4 keV down to 100 eV, the lowest energy probed so far. The results show no sign of an ionization production threshold above 100 eV. These results call for further investigation of the ionization yield theory and a comprehensive determination of the detector response function at energies below the keV scale.

A model industrial workhorse: Bacillus subtilis strain 168 and its genome after a quarter of a century

The vast majority of genomic sequences are automatically annotated using various software programs. The accuracy of these annotations depends heavily on the very few manual annotation efforts that combine verified experimental data with genomic sequences from model organisms. Here, we summarize the updated functional annotation of Bacillus subtilis strain 168, a quarter century after its genome sequence was first made public. Since the last such effort 5 years ago, 1168 genetic functions have been updated, allowing the construction of a new metabolic model of this organism of environmental and industrial interest. The emphasis in this review is on new metabolic insights, the role of metals in metabolism and macromolecule biosynthesis, functions involved in biofilm formation, features controlling cell growth, and finally, protein agents that allow class discrimination, thus allowing maintenance management, and accuracy of all cell processes. New 'genomic objects' and an extensive updated literature review have been included for the sequence, now available at the International Nucleotide Sequence Database Collaboration (INSDC: AccNum AL009126.4).

Synchronous bilateral laparoscopic adrenalectomy: Surgical technique and perioperative results of a 13-years' experience

INTRODUCTION AND OBJECTIVES

Laparoscopic surgery is the standard approach for the treatment of adrenal glands. Bilateral synchronous adrenalectomy is rarely performed, and evidence about this procedure is limited. Our objective is to report our 13-year experience with synchronous laparoscopic bilateral adrenalectomy, evaluating its feasibility, safety, and perioperative outcomes.

PATIENTS AND METHODS

A total of 23 consecutive patients undergoing synchronous bilateral laparoscopic adrenalectomy between 2007 and 2020 in a single academic center were included. Variables evaluated were operative time, estimated blood loss, conversion to open surgery, postoperative complications, mortality, and postoperative length of stay.

RESULTS

Mean operative time was 189.3 ± 48.9 min. Mean estimated blood loss was 163.0 ± 201.3 mL. There were no conversions to open surgery. Five patients had postoperative complications, three of those were major. No patient died in the perioperative period. Median postoperative length of stay was three days (range 1-30). At pathology analysis, 15 patients had bilateral adrenal hyperplasia, 2 unilateral adrenal hyperplasia and a contralateral benign tumor, 1 unilateral adrenal hyperplasia and a normal contralateral gland, 1 unilateral adenoma, 3 bilateral pheochromocytomas and 1 bilateral myelolipoma.

CONCLUSION

Synchronous bilateral laparoscopic adrenalectomy is a feasible and safe technique. A multidisciplinary and experienced team involving anesthesiologists and endocrinologists is required.

Novel Dormancy Mechanism of Castration Resistance in Bone Metastatic Prostate Cancer Organoids

Advanced prostate cancer (PCa) patients with bone metastases are treated with androgen pathway directed therapy (APDT). However, this treatment invariably fails and the cancer becomes castration resistant. To elucidate resistance mechanisms and to provide a more predictive pre-clinical research platform reflecting tumor heterogeneity, we established organoids from a patient-derived xenograft (PDX) model of bone metastatic prostate cancer, PCSD1. APDT-resistant PDX-derived organoids (PDOs) emerged when cultured without androgen or with the anti-androgen, enzalutamide. Transcriptomics revealed up-regulation of neurogenic and steroidogenic genes and down-regulation of DNA repair, cell cycle, circadian pathways and the severe acute respiratory syndrome (SARS)-CoV-2 host viral entry factors, ACE2 and TMPRSS2. Time course analysis of the cell cycle in live cells revealed that enzalutamide induced a gradual transition into a reversible dormant state as shown here for the first time at the single cell level in the context of multi-cellular, 3D living organoids using the Fucci2BL fluorescent live cell cycle tracker system. We show here a new mechanism of castration resistance in which enzalutamide induced dormancy and novel basal-luminal-like cells in bone metastatic prostate cancer organoids. These PDX organoids can be used to develop therapies targeting dormant APDT-resistant cells and host factors required for SARS-CoV-2 viral entry.

Abstract 6109: Enzalutamide treatment of patient derived bone metastatic prostate cancer xenograft models implanted in the bone resulted in durable progression to castration resistant prostate cancer (CRPC)

Background: Upon diagnosis of castration-resistant prostate cancer (CRPC), 84% of patients present with metastases and their survival rate is 28% despite improvements in treatment options. PCSD1, a patient-derived xenograft from a prostate cancer bone metastasis replicated the donor patient's CRPC and was resistant to the anti-androgen drug, bicalutamide, in the bone niche. To further understand the mechanisms of androgen deprivation therapy (ADT) resistance, we treated PCSD1 and PCSD13, a novel patient derived xenograft model from a small cell prostate cancer bone metastasis, with the more potent anti-androgen, Enzalutamide.

Methods: PDX cells were implanted into male Rag2−/−γc−/− mice intra-femorally (IF) or subcutaneously (SC). Mice with established tumors were treated o.g. for 4-5 weeks with Enzalutamide (10mg/kg/day) or Vehicle control. Tumor growth was measured bi-weekly with calipers and in vivo bioluminescence (IVIS). Tumors were analyzed using FACS, RNASeq, whole exome sequencing (WES) and Oncoscan.

Results: PCSD1 and PCSD13 tumors were resistant to enzalutamide when implanted in the femur bone but not sub-cutaneously. When the enzalutamide-resistant tumor cells from the bone were re-injected sub-cutaneously they retained their enzalutamide resistance in contrast to treatment-naïve PCSD1 SC tumors. Transcriptomic analysis revealed significant modulation of WNT5A, EMT and neuronal programs. Single cell analyses revealed heterogeneous sub-populations that behave as cancer stem cells in 3D organoid cultures. Genome-wide CNV analysis of patient bone metastasis samples from the same patient obtained 10 months apart and his xenografts revealed extensive CNVs which were highly conserved between the patient samples and xenografts.

Conclusions: Our PDX models demonstrated that the bone niche promotes tumor growth and malignant progression even when treated with the potent anti-androgen, enzalutamide. These PDX models of bone metastatic prostate cancer were resistant to enzalutamide in the femur bone (IF) but sensitive in the sub-cutaneous environment (SC). Enzalutamide resistance in the bone produced a permanent change in the tumor cells that was retained when re-injected in the sub-cutaneous location. This elucidates the importance of utilizing in vivo patient derived models to gain a better understanding of why the bone niche supports tumor growth.

Citation Format: Christina A.M. Jamieson, Michelle T. Muldong, Sanghee Lee, Christina N. Wu, Danielle N. Burner, Theresa R. Mendoza, Catalina Arreola, Abril Zuniga, Nicholas A. Cacalano, Catriona H. Jamieson, Christopher J. Kane, Anna A. Kulidjian. Enzalutamide treatment of patient derived bone metastatic prostate cancer xenograft models implanted in the bone resulted in durable progression to castration resistant prostate cancer (CRPC) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6109.

Evaluation of new external quality assessment guidelines involving random blinded rechecking of acid-fast bacilli smears in a pilot project setting in Mexico

SETTING

Laboratories in Mexico that support the national tuberculosis (TB) control program have been involved in an acid-fast bacilli (AFB) microscopy external quality assurance program which includes rechecking 100% of smears identified as AFB-positive by the local laboratories and 10% of smears identified as AFB-negative. Very few errors have been detected in Mexico using non-random selection and unblinded rechecking of the slides.

OBJECTIVE

To evaluate the results from a 1-year pilot program involving blinded rechecking of randomly selected AFB slides from local TB laboratories in two Mexican states and determine its feasibility for future implementation.

DESIGN

To reduce potential bias, laboratory staff from the National TB Laboratory, Institute for Epidemiological Diagnosis and Reference (InDRE), performed quarterly statistical sampling of AFB smears and on-site evaluations in local laboratories in each state. AFB smears were rechecked at the respective state laboratories with discordant results resolved at InDRE.

RESULTS

A significantly greater percentage of errors was detected on the randomly selected, blinded AFB smears than on the non-randomly selected, unblinded smears.

CONCLUSION

Random blinded rechecking provides more accurate estimates of AFB microscopy results, resulting in improved diagnosis and monitoring of treatment response.

1 Patterning the limb before and after SHH

The Summer Meeting of the Anatomical Society of Great Britain and Ireland was held at the University of Dundee, from 23rd to 25th July 2002. It included a symposium on 'How to make a hand'. The following are abstracts of communications and posters presented at the meeting.

Roles of macrophages in measles virus infection of genetically modified mice

Knowledge of the mechanisms of virus dissemination in acute measles is cursory, but cells of the monocyte/macrophage (MM) lineage appear to be early targets. We characterized the dissemination of the Edmonston B vaccine strain of measles virus (MV-Ed) in peripheral blood mononuclear cells (PBMC) of two mouse strains expressing the human MV-Ed receptor CD46 with human-like tissue specificity and efficiency. In one strain the alpha/beta interferon receptor is defective, allowing for efficient MV-Ed systemic spread. In both mouse strains the PBMC most efficiently infected were F4/80-positive MMs, regardless of the inoculation route used. Circulating B lymphocytes and CD4-positive T lymphocytes were infected at lower levels, but no infected CD8-positive T lymphocytes were detected. To elucidate the roles of MMs in infection, we depleted these cells by clodronate liposome treatment in vivo. MV-Ed infection of splenic MM-depleted mice caused strong activation and infection of splenic dendritic cells (DC), followed by enhanced virus replication in the spleen. Similarly, depletion of lung macrophages resulted in strong activation and infection of lung DC. Thus, in MV infections of genetically modified mice, blood monocytes and tissue macrophages provide functions beneficial for both the virus and the host: they support virus replication early after infection, but they also contribute to protecting other immune cells from infection. Human MM may have similar roles in acute measles.

Recombinant measles viruses expressing heterologous antigens of mumps and simian immunodeficiency viruses

We have genetically engineered a panel of recombinant measles viruses (rMVs) that express from various positions within the MV genome either the HN or F surface glycoproteins of mumps virus (MuV) or the env, gag or pol proteins from simian immunodeficiency virus (SIV). All rMVs were rescued from the respective antigenomic plasmid constructs; progeny viruses replicated comparably to the progenitor Edmonston B MV, but showed slight propagation retardation, which was dependent on the size and nature of the expressed proteins and on the genomic position of the inserts. All transgenes except that encoding mumps F glycoprotein were faithfully maintained and expressed even after virus amplification by 10(20). Our results suggest possible applications of rMVs as live-attenuated, multivalent vaccines against retroviruses such as SIV and HIV as well as other pathogens more distantly related to MV than MuV.

The short stature homeobox gene SHOX is involved in skeletal abnormalities in Turner syndrome

Turner syndrome is characterized by short stature and is frequently associated with a variable spectrum of somatic features including ovarian failure, heart and renal abnormalities, micrognathia, cubitus valgus, high-arched palate, short metacarpals and Madelung deformity. Madelung deformity is also a key feature of Leri-Weill syndrome. Defects of the pseudoautosomal homeobox gene SHOX were previously shown to lead to short stature and Leri-Weill syndrome, and haploinsufficiency of SHOX was implicated to cause the short stature phenotype in Turner syndrome. Despite exhaustive searches, no direct murine orthologue of SHOX is evident. SHOX is, however, closely related to the SHOX2 homeobox gene on 3q, which has a murine counterpart, Og12x. We analysed SHOX and SHOX2 expression during human embryonic development, and referenced the expression patterns against those of Og12x. The SHOX expression pattern in the limb and first and second pharyngeal arches not only explains SHOX -related short stature phenotypes, but also for the first time provides evidence for the involvement of this gene in the development of additional Turner stigmata. This is strongly supported by the presence of Turner-characteristic dysmorphic skeletal features in patients with SHOX nonsense mutations.

Dickkopf genes are co-ordinately expressed in mesodermal lineages

Dickkopf-1 (dkk-1) is member of a novel family of secreted proteins and functions in head induction during Xenopus embryogenesis, acting as a potent inhibitor of Wnt signalling. Here we report: (1) the isolation of two additional murine members of the dkk family, dkk-2 and dkk-3; and (2) analysis of adult and embryonic gene expression of mouse dkk-1,-2, and -3, Xenopus dkk-1 as well as chicken dkk-3. Comparative developmental analyses of the dkk-1, dkk-2 and dkk-3 in mice indicate that these genes are both temporally and spatially regulated. They define overlapping deep domains in mesenchymal lineages suggesting a co-ordinated mode of action. All dkks show distinct and elevated expression patterns in tissues that mediate epithelial- mesenchyme transformations suggesting that they may participate in heart, tooth, hair and whisker follicle, limb and bone induction. In the limb buds expression of these genes are found in regions of programmed cell death. In a given organ, dkk-1 tends to be the earliest member expressed. Comparison with Xenopus dkk-1 and chicken dkk-3 shows evolutionarily conserved expression patterns. Our observations indicate that dkk genes constitute a new family of secreted proteins that may mediate inductive interactions between epithelial and mesenchymal cells.

Formin defines a large family of morphoregulatory genes and functions in establishment of the polarising region

Formin was originally isolated as the gene affected by the murine limb deformity (ld) mutations, which disrupt the epithelial-mesenchymal interactions regulating patterning of the vertebrate limb autopod. More recently, a rapidly growing number of genes with similarity to formin have been isolated from many different species including fungi and plants. Genetic and biochemical analysis shows that formin family members function in cellular processes regulating either cytokinesis and/or cell polarisation. Another common feature among formin family members is their requirement in morphogenetic processes such as budding and conjugation of yeast, establishment of Drosophila oocyte polarity and vertebrate limb pattern formation. Vertebrate formins are predominantly nuclear proteins which control polarising activity in limb buds through establishment of the SHH/FGF-4 feedback loop. Formin acts in the limb bud mesenchyme to induce apical ectodermal ridge (AER) differentiation and FGF-4 expression in the posterior AER compartment. Finally, disruption of the epithelial-mesenchymal interactions controlling induction of metanephric kidneys in ld mutant embryos indicates that formin might function more generally in transduction of morphogenetic signals during embryonic pattern formation.

Immortalized cell lines derived from mice lacking both type I and type II IFN receptors unify some functions of immature and mature dendritic cells

Cells with dendritic morphology obtained from several organs of mice lacking both type I and II IFN receptors were immortalized by a retrovirus and analysed for their phenotype and for their function to induce cognate immune responses in vitro and in vivo. Two cell lines called AG101 (skin) and AG116 (brain) were cloned and analysed in more detail. They constitutively expressed the cell surface markers CD45, CD11b, MHC class II, F4/80, N418, B7-2 and ICAM1 but were CD8- and B220-negative. Cells from both lines were capable of taking up ovalbumin (OVA). The processed protein was presented to the OVA-specific T cell hybridoma BO97.105 which responded specifically with the production of IL-2. AG101 and AG116 cells were able to induce a mixed lymphocyte reaction as shown by a 50-fold increase of IL-2 production over background. Naive T cells were stimulated by antigen-primed AG101 and AG116, resulting in a T cell proliferation which was 20-30 times over background, and in IL-2 production it was 10 times the background. The capacity of AG101 or AG116 cells to prime naive T cells was directly compared with freshly isolated and cultured cutaneous dendritic cells (DC) from 129 Sv/Ev mice (wtDC). After cognate T cell interaction, IL-6 (20-100-fold) and IL-12 p40 (100-1000-fold) were similarly up-regulated in either AG101, AG116 or mature wtDC. To analyse the capacity of the immortalized DC to induce antibodies in vivo, cell line AG116 was permanently infected with Borna disease virus (BDV) which is unable to replicate in adult mice. One hundred and twenty-nine Sv/Ev mice injected with different cell numbers of AG116 carrying BDV (but not control cells) produced antibodies against the viral BDVp40 and BDVp24 protein. Therefore, the cell lines AG101 and AG116 appear to unify some functions of immature and mature DC. They are able to pick up antigen and process it. In the absence of externally added cytokines, the antigen presented on AG101 or AG116 cells drives T cells with an efficiency similar to mature DC. The cloned cell lines may prove to be useful to study both immune response and replication of infectious agents in the absence of functional interferon receptors.

Epidemic cholera in rural El Salvador: risk factors in a region covered by a cholera prevention campaign

In response to the Latin American cholera epidemic, El Salvador began a prevention programme in April 1991. The first case was confirmed in August, and 700 cases were reported within 3 months. A matched case-control study was conducted in rural La Libertad Department in November 1991. Illness was associated with eating cold cooked or raw seafood (odds ratio [OR] = 7.0; 95% confidence limits [CL] = 1.4, 35.0) and with drinking water outside the home (OR = 8.8; 95% CL = 1.7, 44.6). Assertion of knowledge about how to prevent cholera (OR = 0.2; 95% CL = 0.1, 0.8) and eating rice (OR = 0.2; 95% CL = 0.1, 0.8) were protective. More controls than patients regularly used soap (OR = 0.3; 95% CL = 0.1, 1.0). This study demonstrated three important points for cholera prevention: (1) seafood should be eaten cooked and hot; (2) populations at risk should be taught to treat household drinking water and to avoid drinking water outside the home unless it is known to be treated; and (3) education about hygiene can be an important tool in preventing cholera.

[Value of preoperative colonoscopy in colon-rectal neoplasms]

The surgical approach to treat colo-rectal carcinoma is usually based on the findings of barium enema. In 102 patients we reviewed the yield of pre-operative colonoscopy. Barium enema revealed the cancer in 76 of 84 patients (91%), whereas colonoscopy did so in 96 of 102 subjects (94%). In addition, 5 associated cancerous lesions were demonstrated by colonoscopy and none by barium enema. Associated benign lesions were seen in 14 patients. In 5 patients the surgical plan based on the barium enema was modified by the findings at colonoscopy. Eight false negatives to barium enema were correctly diagnosed by colonoscopy. We conclude that colonoscopy yields valuable information, beyond that of barium enema, in patients with colo-rectal cancer.