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Introduction: Artificial intelligence has started to become a part of scientific studies and may help researchers with a wide range of tasks. However, no scientific studies have been published on its ussefulness in writing cover letters for scientific articles. This study aimed to determine whether Generative Pre-Trained Transformer (GPT)-4 is as good as humans in writing cover letters for scientific papers., Methods: In this randomised non-inferiority study, we included two parallel arms consisting of cover letters written by humans and by GPT-4. Each arm had 18 cover letters, which were assessed by three different blinded assessors. The assessors completed a questionnaire in which they had to assess the cover letters with respect to impression, readability, criteria satisfaction, and degree of detail. Subsequently, we performed readability tests with Lix score and Flesch Kincaid grade level., Results: No significant or relevant difference was found on any parameter. A total of 61% of the blinded assessors guessed correctly as to whether the cover letter was written by GPT-4 or a human. GPT-4 had a higher score according to our objective readability tests. Nevertheless, it performed better than human writing on readability in the subjective assessments., Conclusion: We found that GPT-4 was non-inferior at writing cover letters compared to humans. This may be used to streamline cover letters for researchers, providing an equal chance to all researchers for advancement to peer-review., Funding: This study received no financial support from external sources., Trial Registration: This study was not registered before the study commenced., (Published under Open Access CC-BY-NC-BD 4.0. https://creativecommons.org/licenses/by-nc-nd/4.0/.)

Background Natural language processing models are increasingly used in scientific research, and their ability to perform various tasks in the research process is rapidly advancing. This study aims to investigate whether Generative Pre-trained Transformer 4 (GPT-4) is equal to humans in writing introduction sections for scientific articles. Methods This randomized non-inferiority study was reported according to the Consolidated Standards of Reporting Trials for non-inferiority trials and artificial intelligence (AI) guidelines. GPT-4 was instructed to synthesize 18 introduction sections based on the aim of previously published studies, and these sections were compared to the human-written introductions already published in a medical journal. Eight blinded assessors randomly evaluated the introduction sections using 1-10 Likert scales. Results There was no significant difference between GPT-4 and human introductions regarding publishability and content quality. GPT-4 had one point significantly better scores in readability, which was considered a non-relevant difference. The majority of assessors (59%) preferred GPT-4, while 33% preferred human-written introductions. Based on Lix and Flesch-Kincaid scores, GPT-4 introductions were 10 and two points higher, respectively, indicating that the sentences were longer and had longer words. Conclusion GPT-4 was found to be equal to humans in writing introductions regarding publishability, readability, and content quality. The majority of assessors preferred GPT-4 introductions and less than half could determine which were written by GPT-4 or humans. These findings suggest that GPT-4 can be a useful tool for writing introduction sections, and further studies should evaluate its ability to write other parts of scientific articles., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Sikander et al.)

Mycobacteria can colonize environments where the availability of metal ions is limited. Biological or inorganic chelators play an important role in limiting metal availability, and we developed a model to examine Mycobacterium smegmatis survival in the presence of the chelator sodium citrate. We observed that instead of restricting M. smegmatis growth, concentrated sodium citrate killed M. smegmatis . RNAseq analysis during sodium citrate treatment revealed transcriptional signatures of metal starvation and hyperosmotic stress. Notably, metal starvation and hyperosmotic stress, individually, do not kill M. smegmatis under these conditions. A forward genetic transposon selection was conducted to examine why sodium citrate was lethal, and several sodium-citrate-tolerant mutants were isolated. Based on the identity of three tolerant mutants, mgtE , treZ , and fadD6, we propose a dual stress model of killing by sodium citrate, where sodium citrate chelate metals from the cell envelope and then osmotic stress in combination with a weakened cell envelope causes cell lysis. This sodium citrate tolerance screen identified mutants in several other genes with no known function, with most conserved in the pathogen M. tuberculosis . Therefore, this model will serve as a basis to define their functions, potentially in maintaining cell wall integrity, cation homeostasis, or osmotolerance. IMPORTANCE Bacteria require mechanisms to adapt to environments with differing metal availability. When Mycobacterium smegmatis is treated with high concentrations of the metal chelator sodium citrate, the bacteria are killed. To define the mechanisms underlying killing by sodium citrate, we conducted a genetic selection and observed tolerance to killing in mutants of the mgtE magnesium transporter. Further characterization studies support a model where killing by sodium citrate is driven by a weakened cell wall and osmotic stress, that in combination cause cell lysis., Competing Interests: R.B.A. is the founder and owner of Tarn Biosciences, Inc., a company that is working to develop new antimycobacterial drugs.

Latent tuberculosis infection (LTBI) constitutes an important public health problem because of risk of progression to TB disease. Effective treatment of multi-drug resistant (MDR) LTBI would prevent progression to MDR TB disease, which would improve patient and public health outcomes. The majority of MDR LTBI treatment studies have focused on the use of fluoroquinolone-based antibiotic regimens. Options for and experience in the treatment of fluoroquinolone-resistant MDR LTBI are limited in the published literature and not comprehensively addressed in current guidelines. In this review, we share our experience with the treatment of fluoroquinolone-resistant MDR LTBI with linezolid. We discuss treatment options for MDR TB that provide context for predicting effective MDR LTBI treatment, with a focus on the microbiologic and pharmacokinetic properties of linezolid that support its use. We then summarize the evidence for treatment of MDR LTBI. Finally, we present our experiences treating fluoroquinolone-resistant MDR LTBI with linezolid with an emphasis on dosing considerations to optimize efficacy and minimize potential toxicities., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Background: Up to 40% of young medical doctors feel that the internships prepared them insufficiently for the clinical work. This study investigated whether a Clinical Task Force (CTF) could improve internship quality., Methods: The CTF visited internship departments with a triple-targeted approach: first, departments pre-filled a self-evaluating questionnaire; secondly, CTF visited departments to discuss the self-evaluation and previous student evaluations; and thirdly, CTF and departments agreed on several quality-improving focus points to work on after the meeting. Focus points were followed-up after three and 12 months. The impact on internship quality was assessed with departments' student evaluation scores, number of completed focus points, and the effect of completed focus points on a range of learning parameters. The CTF learned several things along the way, that potentially could affect the quality of internships. A shortlist of these was provided to illustrate unmeasurable benefits., Results: The CTF met with 53 out of 60 eligible departments. The CTF and departments agreed upon 197 focus points of which 64% were completed. The three most frequent categories of focus points were Introduction of the students, The departments' evaluation percentage, and The departments' function as an educational site. The mean student evaluation scores did not change significantly, but the individual evaluation parameters changed significantly in two categories. It decreased in the category regarding the students' satisfaction with the clinical lecturers and the scheduled teaching and increased in the category regarding the percentage of students evaluating the department., Conclusion: The CTF's triple-targeted approach did not increase the mean student evaluation score significantly. For departments that completed the agreed focus points, one category increased and another decreased. However, the unmeasurable benefits illustrated that CTF was a good viable linking element between the faculty, departments, and students with the potential of improving other aspects of the quality of internships., Competing Interests: The authors declare no conflict of interest., (© 2023 The Authors.)

Aim: We aimed to investigate how celestial phenomena like zodiac signs, lunar phases, and Friday the 13th impacted the risk of reoperation after groin hernia repair., Methods: We conducted a nationwide register-based study based on the Danish Hernia Database and Danish Patient Safety Authority's Online Register between 2000-2019. We included patients ≥18 years undergoing open Lichtenstein or laparoscopic groin hernia repair. The main outcomes were risk of reoperation after groin hernia repair in relation to patient and surgeon zodiac sign, lunar phase at the time of the repair, and Friday the 13th vs other Fridays., Results: 151,901 groin hernias were included in the analysis of patient zodiac sign, and 25,075 groin hernias were included in the analysis of surgeon zodiac sign. Compared with the Sagittarius, there was a significantly higher risk of reoperation (HR [95% CI]) if the performing surgeon was born under the Capricorn (1.93 [1.16-3.12]); Pisces (1.68 [1.09-2.57]); Aries (1.61 [1.07-2.38]); Taurus (1.62 [1.04-2.54]); Cancer (2.21 [1.48-3.28]); or Virgo (1.71 [1.13-2.59]). Repairs performed under the waxing (1.23 [1.03-1.46]) and the new moon (1.54 [1.11-2.13]) had significantly higher risk of reoperation (HR [95% CI]) compared with the waning moon. Neither patient zodiac sign nor Friday the 13th affected risk of reoperation after groin hernia repair., Conclusions: Surgeons' zodiac sign and lunar phase significantly affected the risk of reoperation after groin hernia repair. Neither patients' zodiac sign nor Friday the 13th influenced on the risk of reoperation after groin hernia repair. This indicates why significant findings should be considered carefully to distinguish between random statistical association and cause-and-effect relations., Competing Interests: Nil, (© PMA.)

In defined media supplemented with single carbon sources, Mycobacterium tuberculosis (Mtb) exhibits carbon source specific growth restriction. When supplied with glycerol as the sole carbon source at pH 5.7, Mtb establishes a metabolically active state of nonreplicating persistence known as acid growth arrest. We hypothesized that acid growth arrest on glycerol is not a metabolic restriction, but rather an adaptive response. To test this hypothesis, we selected for and identified several Mtb mutants that could grow under these restrictive conditions. All mutations were mapped to the ppe51 gene and resulted in variants with 3 different amino acid substitutions- S211R, E215K, and A228D. Expression of the ppe51 variants in Mtb promoted growth at acidic pH showing that the mutant alleles are sufficient to cause the dominant gain-of-function, Enhanced Acid Growth (EAG) phenotype. Testing growth on other single carbon sources showed the PPE51 variants specifically enhanced growth on glycerol, suggesting PPE51 plays a role in glycerol uptake. Using radiolabeled glycerol, enhanced glycerol uptake was observed in Mtb expressing the PPE51 (S211R) variant, with glycerol overaccumulation in triacylglycerol. Notably, the EAG phenotype is deleterious for growth in macrophages, where the mutants have selectively faster replication and reduced survival in activated macrophages compared to resting macrophages. Recombinant PPE51 protein exhibited differential thermostability in the wild type (WT) or S211R variants in the presence of glycerol, supporting the model that EAG substitutions alter PPE51-glycerol interactions. Together, these findings support that PPE51 variants selectively promote glycerol uptake and that slowed growth at acidic pH is an important adaptive mechanism required for macrophage pathogenesis. IMPORTANCE It is puzzling why Mycobacterium tuberculosis (Mtb) cannot grow on glycerol at acidic pH, as it has a carbon source and oxygen, everything it needs to grow. In this study, we found that Mtb limits uptake of glycerol at acidic pH to restrict its growth and that mutations in ppe51 promote uptake of glycerol at acidic pH and enable growth. That is, Mtb can grow well at acidic pH on glycerol, but has adapted instead to stop growth. Notably, ppe51 variants exhibit enhanced replication and reduced survival in activated macrophages, supporting a role for pH-dependent slowed growth during macrophage pathogenesis.

Neurodevelopmental disorders are highly heterogenous conditions resulting from abnormalities of brain architecture and/or function. FBXW7 (F-box and WD-repeat-domain-containing 7), a recognized developmental regulator and tumor suppressor, has been shown to regulate cell-cycle progression and cell growth and survival by targeting substrates including CYCLIN E1/2 and NOTCH for degradation via the ubiquitin proteasome system. We used a genotype-first approach and global data-sharing platforms to identify 35 individuals harboring de novo and inherited FBXW7 germline monoallelic chromosomal deletions and nonsense, frameshift, splice-site, and missense variants associated with a neurodevelopmental syndrome. The FBXW7 neurodevelopmental syndrome is distinguished by global developmental delay, borderline to severe intellectual disability, hypotonia, and gastrointestinal issues. Brain imaging detailed variable underlying structural abnormalities affecting the cerebellum, corpus collosum, and white matter. A crystal-structure model of FBXW7 predicted that missense variants were clustered at the substrate-binding surface of the WD40 domain and that these might reduce FBXW7 substrate binding affinity. Expression of recombinant FBXW7 missense variants in cultured cells demonstrated impaired CYCLIN E1 and CYCLIN E2 turnover. Pan-neuronal knockdown of the Drosophila ortholog, archipelago, impaired learning and neuronal function. Collectively, the data presented herein provide compelling evidence of an F-Box protein-related, phenotypically variable neurodevelopmental disorder associated with monoallelic variants in FBXW7., Competing Interests: Declaration of interests I.E.S. has served on scientific advisory boards for UCB, Eisai, GlaxoSmithKline, BioMarin, Nutricia, Rogcon, Chiesi, Encoded Therapeutics, Xenon Pharmaceuticals, and Knopp Biosciences; has received speaker honoraria from GlaxoSmithKline, UCB, BioMarin, Biocodex, and Eisai; has received funding for travel from UCB, Biocodex, GlaxoSmithKline, Biomarin and Eisai; has served as an investigator for Zogenix, Zynerba, Ultragenyx, GW Pharma, UCB, Eisai, Anavex Life Sciences, Ovid Therapeutics, Epygenyx, Encoded Therapeutics and Marinus; and has consulted for Zynerba Pharmaceuticals, Atheneum Partners, Ovid Therapeutics, Care Beyond Diagnosis, Epilepsy Consortium and UCB. She may accrue future revenue on pending patent WO2009/086591; her patent for SCN1A testing is held by Bionomics and is licensed to various diagnostic companies; and she has a patent for a molecular diagnostic/therapeutic target for benign familial infantile epilepsy (BFIE) (PRRT2), WO/2013/059884. She receives and/or has received research support from the National Health and Medical Research Council of Australia, Medical Research Future Fund, Health Research Council of New Zealand, CURE, Australian Epilepsy Research Fund, and the National Institute of Neurological Disorders and Stroke of the National Institutes of Health. J.P. is co-chief scientific officer for Global Gene Corp. All other authors declare no competing interests., (Copyright © 2022 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

Competing Interests: The authors have declared that no competing interests exist.

Long-chain fatty-acid oxidation disorders (LC-FAODs) are autosomal recessive inherited metabolic conditions that occur due to a disruption in the body's ability to perform mitochondrial beta oxidation. Expanded newborn screening is widening phenotypic understanding of these disorders, as well improving our knowledge of disease incidence. Management of these disorders is focused on avoidance of fasting, dietary changes and supplementation with energy sources that bypass the metabolic block. Recent US Food and Drug Administration approval of triheptanoin has improved the outcome for affected individuals. New research into dietary modifications and novel pharmacologic therapies continues for these disorders. In this article, we review the major LC-FAODs and their clinical presentation., Competing Interests: Disclosures: Barbara K Burton has received consulting fees and/or honoraria from Ultragenyx Pharmaceutical Inc. Joshua J Baker has no financial or non-financial relationships or activities to declare in relation to this article., (© Touch Medical Media 2021.)

Psychedelics, compounds that can induce dramatic changes in conscious experience, have been used by humans for centuries. Recent studies have shown that certain psychedelics can induce neural plasticity by promoting neurite growth and synapse formation. In this review, we focus on the role of classical serotonergic psychedelics in neural plasticity and discuss its implication for their therapeutic potentials., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Lukasiewicz, Baker, Zuo and Lu.)

Monomeric boroles have been gaining attention as reagents for the synthesis of heterocycles due to their ability to insert atoms into the BC 4 ring in a single step. Although unique boron frameworks can be accessed via this methodology, the products feature aryl substitution on the carbon centers as steric bulk is required to preclude borole dimerization. This work demonstrates that insertion chemistry is possible with Diels-Alder dimeric boroles and that such reactivity is not exclusive to monomeric boroles with bulky groups. With 1-phenyl-2,3,4,5-tetramethylborole dimer, the formal 1,1-insertion of a nitrene and sulfur generate the six-membered aromatic 1,2-azaborine and 1,2-thiaborine, respectively. The isolation of the 1,2-thiaborine enabled the synthesis of an η 6 -chromium complex. Benzophenone and diphenylketene readily insert a CO unit to generate BOC 5 seven-membered rings confirming dimeric boroles can serve as monomeric synthons in 1,2-insertion reactions. An epoxide did not furnish the anticipated eight-membered BOC 6 ring, instead provided a bicyclic system with a BOC 3 ring. The insertion chemistry was demonstrated with two other borole dimers featuring different substitution with diphenylketene as a substrate. This work elevates borole insertion chemistry to a new level to access products that do not require bulky substitution., (This journal is © The Royal Society of Chemistry 2020.)

Mycobacterium tuberculosis (Mtb) senses and adapts to acidic environments during the course of infection. Acidic pH-dependent adaptations include the induction of metabolic genes associated with anaplerosis and growth arrest on specific carbon sources. Here we report that deletion of isocitrate lyase or phosphoenolpyruvate carboxykinase results in reduced growth at acidic pH and altered metabolite profiles, supporting that remodeling of anaplerotic metabolism is required for pH-dependent adaptation. Mtb cultured at pH 5.7 in minimal medium containing glycerol as a single carbon source exhibits an acid growth arrest phenotype, where the bacterium is non-replicating but viable and metabolically active. The bacterium assimilates and metabolizes glycerol and maintains ATP pools during acid growth arrest and becomes tolerant to detergent stress and the antibiotics isoniazid and rifampin. A forward genetic screen identified mutants that do not arrest their growth at acidic pH, including four enhanced acid growth (eag) mutants with three distinct mutations in the proline-proline-glutamate (PPE) gene MT3221 (also named ppe51). Overexpression of the MT3221(S211R) variant protein in wild type Mtb results in enhanced acid growth and reduced drug tolerance. These findings support that acid growth arrest is a genetically controlled, adaptive process and not simply a physiological limitation associated with acidic pH.

Background: Declining mortality has led to a rising number of persons living with HIV (PLWH) and concerns about a future shortage of HIV practitioners., Aim: To develop an HIV Primary Care Track for internal medicine residents., Setting: Academic hospital and community health center with a history of caring for PLWH and lesbian, gay, bisexual, and transgender (LGBT) patients., Participants: Internal medicine residents., Program Description: We enrolled four residents annually in a 3-year track with the goal of having each provide continuity care to at least 20 PLWH. The curriculum included small group learning sessions, outpatient electives, a global health opportunity, and the development of a scholarly project., Program Evaluation: All residents successfully accrued 20 or more PLWH as continuity patients. Senior residents passed the American Academy of HIV Medicine certification exam, and 75 % of graduates took positions in primary care involving PLWH. Clinical performance of residents in HIV care quality measures was comparable to those reported in published cohorts., Discussion: We developed and implemented a novel track to train medical residents in the care of PLWH and LGBT patients. Our results suggest that a designated residency track can serve as a model for training the next generation of HIV practitioners.

Background: Interest in developing more feasible and affordable applications of virtual microscopy in the field of cytology continues to grow., Aims: The aim of this study was to investigate the scanning parameters for the thyroid fine needle aspiration (FNA) cytology specimens., Subjects and Methods: A total of twelve glass slides from thyroid FNA cytology specimens were digitized at ×40 with 1 micron (μ) interval using seven focal plane (FP) levels (Group 1), five FP levels (Group 2), and three FP levels (Group 3) using iScan Coreo Au scanner (Ventana, AZ, USA) producing 36 virtual images (VI). With an average wash out period of 2 days, three participants diagnosed the preannotated cells of Groups 1, 2, and 3 using BioImagene's Image Viewer (version 3.1) (Ventana, Inc., Tucson, AZ, USA), and the corresponding 12 glass slides (Group 4) using conventional light microscopy., Results: All three raters correctly identified and showed complete agreement on the glass and VI for: 86% of the cases at FP Level 3, 83% of the cases at both the FP Levels 5 and 7. The intra-observer concordance between the glass slides and VI for all three raters was highest (97%) for Level 3 and glass, same (94%) for Level 5 and glass; and Level 7 and glass. The inter-rater reliability was found to be highest for the glass slides, and three FP levels (77%), followed by five FP levels (69.5%), and seven FP levels (69.1%)., Conclusions: This pilot study found that among the three different FP levels, the VI digitized using three FP levels had slightly higher concordance, intra-observer concordance, and inter-rater reliability. Scanning additional levels above three FP levels did not improve concordance. We believe that there is no added benefit of acquiring five FP levels or more especially when considering the file size, and storage costs. Hence, this study reports that FP level three and 1 μ could be the potential scanning parameters for the thyroid FNA cytology specimens.

During pathogenesis, Mycobacterium tuberculosis (Mtb) colonizes environments, such as the macrophage or necrotic granuloma, that are acidic and rich in cholesterol and fatty acids. The goal of this study was to examine how acidic pH and available carbon sources interact to regulate Mtb physiology. Here we report that Mtb growth at acidic pH requires host-associated carbon sources that function at the intersection of glycolysis and the TCA cycle, such as pyruvate, acetate, oxaloacetate and cholesterol. In contrast, in other tested carbon sources, Mtb fully arrests its growth at acidic pH and establishes a state of non-replicating persistence. Growth-arrested Mtb is resuscitated by the addition of pyruvate suggesting that growth arrest is due to a pH-dependent checkpoint on metabolism. Additionally, we demonstrate that the phoPR two-component regulatory system is required to slow Mtb growth at acidic pH and functions to maintain redox homeostasis. Transcriptional profiling and functional metabolic studies demonstrate that signals from acidic pH and carbon source are integrated to remodel pathways associated with anaplerotic central metabolism, lipid anabolism and the regeneration of oxidized cofactors. Because phoPR is required for Mtb virulence in animals, we suggest that pH-driven adaptation may be critical to Mtb pathogenesis., (© 2014 John Wiley & Sons Ltd.)

Highly active antiretroviral therapy (HAART) is able to suppress human immunodeficiency virus type 1 (HIV-1) to undetectable levels in the majority of patients, but eradication has not been achieved because latent viral reservoirs persist, particularly in resting CD4(+) T lymphocytes. It is generally understood that HIV-1 does not efficiently infect resting CD4(+) T cells, and latent infection in those cells may arise when infected CD4(+) T lymphoblasts return to resting state. In this study, we found that stimulation by endothelial cells can render resting CD4(+) T cells permissible for direct HIV infection, including both productive and latent infection. These stimulated T cells remain largely phenotypically unactivated and show a lower death rate than activated T cells, which promotes the survival of infected cells. The stimulation by endothelial cells does not involve interleukin 7 (IL-7), IL-15, CCL19, or CCL21. Endothelial cells line the lymphatic vessels in the lymphoid tissues and have frequent interactions with T cells in vivo. Our study proposes a new mechanism for infection of resting CD4(+) T cells in vivo and a new mechanism for latent infection in resting CD4(+) T cells.

Background: Recent studies have demonstrated a high prevalence of pharyngeal (P) and rectal (R) Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) infections among men who have sex with men (MSM). Guidelines by the Centers for Disease Control and Prevention recommend testing at least annually. But surveys of medical providers suggest that adherence to these guidelines is minimal as a result of limited time and staff. Because of these concerns, we evaluated the feasibility and accuracy of patient self-testing., Methods: Three-hundred seventy-four patients at a Washington, DC clinic who identified themselves as MSM and requested testing for sexually transmitted infections (STIs) participated in the study. Patients performed self-screening using the Gen-Probe APTIMA Combo 2 (AC2) kit after viewing written and pictorial instructions. Trained providers also screened patients. We randomized the order in which patients or providers performed testing., Results: Among those receiving specific tests, 8% of patients tested positive for R-GC, 9.3% for P-GC, 12.7% for R-CT, and 1.3% for P-CT. We performed McNemar tests, stratified by infection type and anatomic site to evaluate concordance. Self-administered testing was significantly better at identifying P-GC (discordant: 3%) and R-GC (discordant: 2.9%) (P ≤.01), and had results similar to provider- administered testing for P-CT (discordant: 0.5%) and R-CT (discordant: 1.1%) detection., Conclusions: The equivalent or better detection rates for rectal and oral gonorrhea and chlamydia among patients suggest that patients are capable of performing their own screening for STIs, which may increase infection detection and treatment.

Background: Vpr is exclusively expressed in primate lentiviruses and contributes to viral replication and disease progression in vivo. HIV-1 Vpr has two major activities in vitro: arrest of cell cycle in the G2 phase (G2 arrest), and enhancement of viral replication in macrophages. Previously, we reported a potent HIV-1 restriction in the human CD4+ CEM.NKR (NKR) T cells, where wild-type (WT) HIV-1 replication was inhibited by almost 1,000-fold. From the parental NKR cells, we isolated eight clones by limiting dilution. These clones showed three levels of resistance to the WT HIV-1 infection: non-permissive (NP), semi-permissive (SP), and permissive (P). Here, we compared the replication of WT, Vif-defective, Vpr-defective, and Vpu-defective viruses in these cells., Results: Although both WT and Vpu-defective viruses could replicate in the permissive and semi-permissive clones, the replication of Vif-defective and Vpr-defective viruses was completely restricted. The expression of APOBEC3G (A3G) cytidine deaminase in NKR cells explains why Vif, but not Vpr, was required for HIV-1 replication. When the Vpr-defective virus life cycle was compared with the WT virus life cycle in the semi-permissive cells, it was found that the Vpr-defective virus could enter the cell and produce virions containing properly processed Gag and Env proteins, but these virions showed much less efficiency for reverse transcription during the next-round of infection. In addition, although viral replication was restricted in the non-permissive cells, treatment with arsenic trioxide (As2O3) could completely restore WT, but not Vpr-defective virus replication. Moreover, disruption of Vpr binding to its cofactor DCAF1 and/or induction of G2 arrest activity did not disrupt the Vpr activity in enhancing HIV-1 replication in NKR cells., Conclusions: These results demonstrate that HIV-1 replication in NKR cells is Vpr-dependent. Vpr promotes HIV-1 replication from the 2nd cycle likely by overcoming a block at early stage of viral replication; and this activity does not require DCAF1 and G2 arrest. Further studies of this mechanism should provide new understanding of Vpr function in the HIV-1 life cycle.

Recent genome-wide association studies of individuals of Asian and European descent have found that SNPs located within the genomic region (1p31.3) encoding the Wntless (Wls)/Gpr177 protein are associated significantly with reduced bone mineral density. Wls/Gpr177 is a newly identified chaperone protein that specifically escorts Wnt ligands for secretion. Given the strong functional association between the Wnt signaling pathways and bone development and homeostasis, we generated osteoblast-specific Wls-deficient (Ocn-Cre;Wls-flox) mice. Homozygous conditional knockout animals were born at a normal Mendelian frequency. Whole-body dual-energy X-ray absorptiometry scanning revealed that bone-mass accrual was significantly inhibited in homozygotes as early as 20 d of age. These homozygotes had spontaneous fractures and a high frequency of premature lethality at around 2 mo of age. Microcomputed tomography analysis and histomorphometric data revealed a dramatic reduction of both trabecular and cortical bone mass in homozygous mutants. Bone formation in homozygotes was severely impaired, but no obvious phenotypic change was observed in mice heterozygous for the conditional deletion. In vitro studies showed that Wls-deficient osteoblasts had a defect in differentiation and mineralization, with significant reductions in the expression of key osteoblast differentiation regulators. In summary, these results reveal a surprising and crucial role of osteoblast-secreted Wnt ligands in bone-mass accrual.

The hip region is examined to determine what aspects of musculoskeletal anatomy are precociously developed in primate species with highly specialized modes of locomotion. Muscles of the hind limb were removed and weighed in each specimen, and the hip joint of selected specimens was studied in stained serial sections. No perinatal differences among species are evident, but in adults, the hip joint of Galago moholi (a leaping specialist) appears to have proportionally thick articular cartilage (relative to the subchondral plate) compared to two species of cheirogaleids. Muscle mass distribution in the hind limbs confirms previous observations that the quadriceps femoris muscle is especially large in Galago (in percent mass of the entire hind limb), while the hip region is smaller compared to the more quadrupedal cheirogaleids. Across age groups, the species with the least specialized locomotion as adults, Cheirogaleus medius, shows little or no change in proximal to distal percentage distribution of muscle mass. Galago has a larger percentage mass gain in the thigh. We suggest that muscle mass gain to specific limb segments may be a critical milestone for primates with extremely specialized modes of locomotion.

A rhesus monkey was trained to perform individuated and combined finger flexions of the thumb, index, and middle finger. Nine implantable myoelectric sensors (IMES) were then surgically implanted into the finger muscles of the monkey's forearm, without any adverse effects over two years postimplantation. Using an inductive link, EMG was wirelessly recorded from the IMES as the monkey performed a finger flexion task. The EMG from the different IMES implants showed very little cross correlation. An offline parallel linear discriminant analysis (LDA) based algorithm was used to decode finger activity based on features extracted from continuously presented frames of recorded EMG. The offline parallel LDA was run on intraday sessions as well as on sessions where the algorithm was trained on one day and tested on following days. The performance of the algorithm was evaluated continuously by comparing classification output by the algorithm to the current state of the finger switches. The algorithm detected and classified seven different finger movements, including individual and combined finger flexions, and a no-movement state (chance performance = 12.5%) . When the algorithm was trained and tested on data collected the same day, the average performance was 43.8+/-3.6% n=10. When the training-testing separation period was five months, the average performance of the algorithm was 46.5+/-3.4% n=8. These results demonstrated that using EMG recorded and wirelessly transmitted by IMES offers a promising approach for providing intuitive, dexterous control of artificial limbs where human patients have sufficient, functional residual muscle following amputation.

The Centers for Medicare and Medicaid Services has decided not to pay hospitals a specific rate in 2006 to cover drug handling costs, but that doesn't mean it won't do so in the future. Hospitals that are dividing their reporting of pharmacy costs on Medicare cost reports between "Pharmacy" and "Drugs Charged to Patients" may be exemplifying best practice in accounting for such costs. Best-practice hospitals will help ensure that CMS will set fair rates for drug handling payments to hospitals, in the event it decides such payments are appropriate.

A 10-year-old Tennessee Walking Horse gelding was admitted to the veterinary teaching hospital for evaluation of intermittent fever, lethargy, and anorexia. Initial laboratory analyses revealed anemia and hyperfibrinogenemia. Abdominocentesis and thoracentesis yielded fluid samples with high nucleated cell counts and total protein concentrations. The tentative diagnosis was nonseptic peritonitis. The horse did not improve after 4 days of antimicrobial treatment, and pitting edema of the ventral midline developed. Thoracic radiography and ultrasonography revealed consolidation of the ventral aspect of the lung fields and pleural effusion. Pleuroscopy of the right hemithorax revealed pleural effusion and a soft-tissue mass in the caudal portion of the mediastinum. Findings on biopsy of the liver and mediastinal mass led to a presumptive diagnosis of metastatic cholangiocellular carcinoma. The horse was euthanatized, and the diagnosis was confirmed at necropsy.

Dental plaque deposits are known to be potent stimulants of lymphocyte transformation in patients with periodontal disease but not in normal subjects. Since plaque deposits consist mainly of whole bacteria, the cell walls of the most commonly found organisms in plaque were tested for their capacity to induce lymphocyte transformation. There was a direct correlation between the severity of peridontal disease and the amount of transformation induced by the cell walls of oral bacteria and by solubilized dental plaque. Cord blood leukocytes and lymphocytes from clinically normal people did not respond, which indicates that these stimulants are antigens rather than mitogens. Of the eleven bacteria tested, four members of the family Actinomycetaceae (Actinomyces viscosus, A. israelii, A. naeslundii, and Arachnia propionica), the related Propionibacterium acnes, and an anaerobic gram-negative anaerobic rod (27N). The high prevalence of the former organisms in the mature dental plaque that forms around the gingival crevice area and the potent efficacy with which they stimulate lymphocytes indicates that Actinomyces and certain gram-negative anaerobes may be important etiological agents in chronic periodontal inflammation in man.

Twenty dentulous subjects undergoing clinical therapy for severe periodontitis were used to determine the longitudinal effects of bacterial plaque reduction in vitro lymphocyte transformation. The therapy consisted of either complete extractions or partial extractions and periodontal surgery combined with rigorous oral hygiene. Prior to therapy lymphocytes from these subjects responded significantly to Streptolysin O (SLO) but were not transformed significantly by solubilized dental plaque. However, after therapy lymphocytes from these same subjects responded significantly to both solubilized dental plaque and SLO. This indicates that the severe periodontitis patients were specifically unresponsive to solubilized dental plaque prior to therapy. The mechanism of the unresponsiveness is not clear, but probably does not involve serum factors because supplementation of the lymphocyte cultures with pooled homologous plasma from individuals with gingivitis or moderate periodontitis (instead of the patient's autologous plasma) did not significantly change the mean lymphocyte responses to solubilized dental plaque. In addition, lymphocytes from eleven long-term (5--18 yr) edentulous subjects, who were free of oral inflammation, were significantly transformed by solubilized dental plaque. The latter lymphocyte responses and those of the treated periodontitis patients could be due either to the presence of low levels of oral bacteria in the edentulous mouth or to the lymphocyte transformation assay being a measure of previous antigen sensitization rather than current disease status. In either case, lymphocyte transformation to solubilized dental plaque is not a useful diagnostic tool in periodontitis, but should continue to be a valuable research tool for investigating pathological mechanisms in periodontitis.