Resonant X-ray excitation of the nuclear clock isomer 45Sc.

Resonant oscillators with stable frequencies and large quality factors help us to keep track of time with high precision. Examples range from quartz crystal oscillators in wristwatches to atomic oscillators in atomic clocks, which are, at present, our most precise time measurement devices1. The search for more stable and convenient reference oscillators is continuing2-6. Nuclear oscillators are better than atomic oscillators because of their naturally higher quality factors and higher resilience against external perturbations7-9. One of the most promising cases is an ultra-narrow nuclear resonance transition in 45Sc between the ground state and the 12.4-keV isomeric state with a long lifetime of 0.47 s (ref. 10). The scientific potential of 45Sc was realized long ago, but applications require 45Sc resonant excitation, which in turn requires accelerator-driven, high-brightness X-ray sources11 that have become available only recently. Here we report on resonant X-ray excitation of the 45Sc isomeric state by irradiation of Sc-metal foil with 12.4-keV photon pulses from a state-of-the-art X-ray free-electron laser and subsequent detection of nuclear decay products. Simultaneously, the transition energy was determined as [Formula: see text] with an uncertainty that is two orders of magnitude smaller than the previously known values. These advancements enable the application of this isomer in extreme metrology, nuclear clock technology, ultra-high-precision spectroscopy and similar applications.

ARF1-related disorder: phenotypic and molecular spectrum.

PURPOSE: ARF1 was previously implicated in periventricular nodular heterotopia (PVNH) in only five individuals and systematic clinical characterisation was not available. The aim of this study is to provide a comprehensive description of the phenotypic and genotypic spectrum of ARF1-related neurodevelopmental disorder. METHODS: We collected detailed phenotypes of an international cohort of individuals (n=17) with ARF1 variants assembled through the GeneMatcher platform. Missense variants were structurally modelled, and the impact of several were functionally validated. RESULTS: De novo variants (10 missense, 1 frameshift, 1 splice altering resulting in 9 residues insertion) in ARF1 were identified among 17 unrelated individuals. Detailed phenotypes included intellectual disability (ID), microcephaly, seizures and PVNH. No specific facial characteristics were consistent across all cases, however microretrognathia was common. Various hearing and visual defects were recurrent, and interestingly, some inflammatory features were reported. MRI of the brain frequently showed abnormalities consistent with a neuronal migration disorder. CONCLUSION: We confirm the role of ARF1 in an autosomal dominant syndrome with a phenotypic spectrum including severe ID, microcephaly, seizures and PVNH due to impaired neuronal migration.

CRISPR-ENHANCE: An enhanced nucleic acid detection platform using Cas12a.

Rapid detection of nucleic acids is essential for clinical diagnosis of a wide range of infectious and non-infectious diseases. CRISPR-based diagnostic platforms are well-established for rapid and specific detection of nucleic acids but suffer from a low detection sensitivity without a target pre-amplification step. Our recently developed detection system, called CRISPR-ENHANCE, employs engineered crRNAs and optimized conditions to achieve a significantly higher sensitivity and enable femtomolar levels of nucleic acid detection even without target pre-amplification. Using the CRISPR-ENHANCE platform and following the methodology detailed in this paper, nucleic acid detection for low copy numbers can be achieved in less than an hour through either a fluorescence-based detection or a lateral flow assay. The step-by-step instructions provided, in addition to describing how to perform both assays, incorporate details on a LAMP/RT-LAMP-based target amplification step to enable detection of RNA, ssDNA and dsDNA. Furthermore, a protocol for in-house expression and purification of LbCas12a using CL7/lm7-based affinity chromatography, which has been used to achieve a high yield and purity of the enzyme in a single-step, is provided.

Effects of a Short-Term Heat Acclimation Protocol in Elite Amateur Boxers.

ABSTRACT: Stone, BL, Ashley, JD, Skinner, RM, Polanco, JP, Walters, MT, Schilling, BK, and Kellawan, JM. Effects of a short-term heat acclimation protocol in elite amateur boxers. J Strength Cond Res 36(7): 1966-1971, 2022-Boxing requires proficient technical and tactical skills coupled with high levels of physiological capacity. Although heat and humidity negatively affect acute exercise performance, short-term exercise training in hot and humid environments can lead to physiological adaptations that enhance exercise performance in both hot and thermoneutral conditions. In highly trained endurance athletes, exercise-induced acclimation can occur in as little as 5 days (known as short-term heat acclimation [STHA]). However, the impact of a 5-day heat acclimation (5-DayHA) in combat athletes, such as elite amateur boxers, is unknown. The aim of the present investigation was to determine whether a 5-DayHA improves aerobic performance in a thermoneutral environment and causes positive physiological adaptations in elite boxers. Seven elite amateur boxers underwent a 5-DayHA protocol, consisting of 60-minute exercise sessions in an environmental chamber at 32 °C and 70% relative humidity. Repeat sprint test (RST) evaluated aerobic performance in a thermoneutral environment 24 hours before and after the 5-DayHA. Presession and postsession hydration status (urine specific gravity) and body mass were assessed. After a 5-DayHA period, boxers significantly improved RST performance (13 ± 7 to 19 ± 7 sprints, d = 0.92, p = 0.03) but not pre-exercise hydration status (1.02 ± 0.01 to 1.01 ± 0.01, d = 0.82, p = 0.07). Therefore, these findings suggest 5-DayHA enhances aerobic performance in elite-level amateur boxers and may provide a viable training option for elite combat athletes.

Neuromuscular Fatigue in Pitchers Across a Collegiate Baseball Season.

Stone, BL and Schilling, BK. Neuromuscular fatigue in pitchers across a collegiate baseball season. J Strength Cond Res 34(7): 1933-1937, 2020-Neuromuscular fatigue in baseball pitchers has become an important aspect of injury risk. It is imperative to understand how fatigue is manifested to enhance resiliency and mitigate injury risk. Secondarily, collecting data on neuromuscular characteristics of baseball pitchers provides a framework to address these concerns. Using the countermovement jump, this study observed neuromuscular performance during the preseason, midseason, and postseason of a collegiate baseball season with college baseball pitchers. No statistically significant changes were noted in any of the main variables at any testing timepoint (p > 0.05). However, several variables, including concentric mean force (ConMF, d = 0.59) and concentric peak force (ConPF, d = 0.59) in addition to eccentric mean force (EccMF, d = 0.54) and eccentric mean power (EccMP, d = -0.66), displayed moderate effects from preseason testing to midseason testing. Furthermore, jump height displayed a large negative effect from preseason to midseason (d = -0.89). Secondarily, descriptive data for both concentric and eccentric variables were also determined from the present findings. There were moderate changes in neuromuscular fatigue in Division I collegiate pitchers across a competitive season and has provided descriptive data for neuromuscular characteristics in collegiate baseball pitchers.

Effects of an Experimental vs. Traditional Military Training Program on 2-Mile Run Performance During the Army Physical Fitness Test.

Stone, BL, Heishman, AD, and Campbell, JA. The effects of an experimental vs. traditional military training program on 2-mile run performance during the army physical fitness test. J Strength Cond Res 34(12): 3431-3438, 2020-The purpose of this study was to compare the effects of an experimental vs. traditional military run training on 2-mile run ability in the Army Reserve Officers' Training Corps cadets. Fifty college-aged cadets were randomly placed into 2 groups and trained for 4 weeks with either an experimental running program (EXP, n = 22) comprised rating of perceived exertion (RPE) intensity-specific, energy system-based intervals or with traditional military running program (TRA, n = 28) using a crossover study design. A 2-mile run assessment was performed just before the start, at the end of the first 4 weeks, and again after the second 4 weeks of training after crossover. The EXP program significantly decreased 2-mile run times (961.3 ± 155.8 seconds to 943.4 ± 140.2 seconds, p = 0.012, baseline to post 1), whereas the TRA group experienced a significant increase in run times (901.0 ± 79.2 vs. 913.9 ± 82.9 seconds) over the same training period. There was a moderate effect size (d = 0.61, p = 0.07) for the experimental run program to "reverse" the adverse effects of the traditional program within the 4-week training period (post 1 to post 2) after treatment crossover. Thus, for short-term training of military personnel, RPE intensity-specific running program comprising aerobic and anaerobic system development can enhance 2-mile run performance superior to a traditional program while reducing training volume (60 minutes per session vs. 43.2 minutes per session, respectively). Future research should extend the training period to determine efficacy of this training approach for long-term improvement of aerobic capacity and possible reduction of musculoskeletal injury.

The significance of Trk receptors in pancreatic cancer.

This study investigated the Trk receptor family as a therapeutic target in pancreatic ductal adenocarcinoma and assessed their prognostic significance. Global gene expression analysis was investigated in prospectively collected pancreatic ductal adenocarcinomas that had either undergone neoadjuvant chemoradiation or were treated by surgery. PANC-1 and MIA-PaCa-2 cell lines were investigated to establish whether fractionated radiation altered expression of four neuroendocrine genes and whether this resulted in subsequent changes in radiosensitivity. A specific inhibitor of TrkA, B, and C, AstraZeneca 1332, was investigated in vitro and in vivo in combination with radiation. A tissue microarray was constructed from 77 pancreatic ductal adenocarcinoma patients who had undergone neoadjuvant chemoradiation and the Trk receptor, and neurogenic differentiation 1 expression was assessed and correlated with overall survival. A total of 99 genes were identified that were differentially expressed in the chemoradiation patients with neuroendocrine genes and pathways, in particular the neurogenic differentiation 1 and Trk receptor family, being prominent. Fractionated radiation upregulated the expression of neuroendocrine genes, and AstraZeneca 1332 treatment in vitro enhanced radiosensitivity. No added effect of AstraZeneca 1332 was observed in vivo. Trk receptor expression varied between isoforms but did not correlate significantly with clinical outcome. Radiation treatment upregulated neuroendocrine gene expression but the Trk receptor family does not appear to be a promising treatment target.

The TRAIL receptor agonist drozitumab targets basal B triple-negative breast cancer cells that express vimentin and Axl.

Previously, we found that GST-tagged tumor necrosis factor-related apoptosis inducing ligand preferentially killed triple-negative breast cancer (TNBC) cells with a mesenchymal phenotype by activating death receptor 5 (DR5). The purpose of this study was to explore the sensitivity of breast cancer cell lines to drozitumab, a clinically tested DR5-specific agonist; identify potential biomarkers of drozitumab-sensitive breast cancer cells; and determine if those biomarkers were present in tumors from patients with TNBC. We evaluated viability, caspase activity, and sub-G1 DNA content in drozitumab-treated breast cancer cell lines and we characterized expression of potential biomarkers by immunoblot. Expression levels of vimentin and Axl were then explored in 177 TNBC samples from a publically available cDNA microarray dataset and by immunohistochemistry (IHC) in tumor tissue samples obtained from 53 African-American women with TNBC. Drozitumab-induced apoptosis in mesenchymal TNBC cell lines but not in cell lines from other breast cancer subtypes. The drozitumab-sensitive TNBC cell lines expressed the mesenchymal markers vimentin and Axl. Vimentin and Axl mRNA and protein were expressed in a subset of human TNBC tumors. By IHC, ~15 % of TNBC tumors had vimentin and Axl expression in the top quartile for both. These findings indicate that drozitumab-sensitive mesenchymal TNBC cells express vimentin and Axl, which can be identified in a subset of human TNBC tumors. Thus, vimentin and Axl may be useful to identify TNBC patients who would be most likely to benefit from a DR5 agonist.

Chromogranin A staining as a prognostic variable in newly diagnosed Gleason score 7-10 prostate cancer treated with definitive radiotherapy.

PURPOSE: To demonstrate the association of neuroendocrine differentiation, as identified by chromogranin A (CgA) staining, with clinical outcomes in newly diagnosed prostatic adenocarcinoma treated with definitive radiotherapy (RT). MATERIALS/METHODS: Patients with Gleason score ≥7 adenocarcinoma were identified from our outcomes database. RT consisted of external beam, brachytherapy, or external beam with brachytherapy boost. Biopsy specimens were stained for neuroendocrine differentiation with CgA. Results were interpreted by a single pathologist. CgA staining was quantified as 0%, <1%, 1-10%, or >10% of tumor cells. Clinical outcomes were blinded at the time of pathologic evaluation. RESULTS: CgA staining was performed on 289 patients. 149 patients had Gleason score 7, and 140 were Gleason score 8-10. Median follow-up was 6.5 years. For patients with <1% versus >1% CgA staining, pretreatment characteristics were well-balanced. CgA staining was detected in 90 cases (31%). 58 patients had focal positive (<1%) CgA staining, and 32 cases had >1% of tumor cells CgA positive. Patients with >1% CgA staining had inferior biochemical control, clinical failure, distant metastases (DM), and cause-specific survival (CSS) rates. Ten-year rates of DM were 8% versus 48% for patients with <1% versus >1% CgA positive cells, respectively (P < 0.001). CSS at 10 years was 95% versus 76%, respectively (P < 0.001). Local control was equivalent in the two patient cohorts. Patients with <1% CgA staining had similar outcomes to those patients with 0% staining. CONCLUSIONS: Neuroendocrine differentiation involving >1% of tumor cells on prostate cancer biopsies is a predictor of DM and CSS in patients treated with primary RT.

Clinical validation of engineered CRISPR/Cas12a for rapid SARS-CoV-2 detection.

Background: The coronavirus disease (COVID-19) caused by SARS-CoV-2 has swept through the globe at an unprecedented rate. CRISPR-based detection technologies have emerged as a rapid and affordable platform that can shape the future of diagnostics. Methods: We developed ENHANCEv2 that is composed of a chimeric guide RNA, a modified LbCas12a enzyme, and a dual reporter construct to improve the previously reported ENHANCE system. We validated both ENHANCE and ENHANCEv2 using 62 nasopharyngeal swabs and compared the results to RT-qPCR. We created a lyophilized version of ENHANCEv2 and characterized its detection capability and stability. Results: Here we demonstrate that when coupled with an RT-LAMP step, ENHANCE detects COVID-19 samples down to a few copies with 95% accuracy while maintaining a high specificity towards various isolates of SARS-CoV-2 against 31 highly similar and common respiratory pathogens. ENHANCE works robustly in a wide range of magnesium concentrations (3 mM-13 mM), allowing for further assay optimization. Our clinical validation results for both ENHANCE and ENHANCEv2 show 60/62 (96.7%) sample agreement with RT-qPCR results while only using 5 µL of sample and 20 minutes of CRISPR reaction. We show that the lateral flow assay using paper-based strips displays 100% agreement with the fluorescence-based reporter assay during clinical validation. Finally, we demonstrate that a lyophilized version of ENHANCEv2 shows high sensitivity and specificity for SARS-CoV-2 detection while reducing the CRISPR reaction time to as low as 3 minutes while maintaining its detection capability for several weeks upon storage at room temperature. Conclusions: CRISPR-based diagnostic platforms offer many advantages as compared to conventional qPCR-based detection methods. Our work here provides clinical validation of ENHANCE and its improved form ENHANCEv2 for the detection of COVID-19.

Investigation of the Prognostic Significance of Neuroendocrine Differentiation in Gleason Score 7 to 10 Prostate Adenocarcinoma in Patients With Distant Metastasis After Definitive Radiotherapy.

OBJECTIVES: We investigated the prognostic implications of neuroendocrine differentiation (NED) in prostate adenocarcinoma detected by chromogranin A (CgA) in patients who developed distant metastasis (DM) after radiotherapy. METHODS: Patients with Gleason score 7 to 10 conventional acinar prostate adenocarcinoma treated with definitive radiotherapy and with core biopsy CgA staining completed were reviewed. Patients who developed DM, defined as disease beyond the primary tumor or pelvic lymph nodes, underwent detailed chart review. Statistical analysis included Kaplan-Meier estimates and descriptive statistics to compare based on quantification of CgA staining. RESULTS: Thirty-five patients had confirmed DM. Twenty-five patients had less than 1% of cells staining positive for CgA, and 10 patients had more than 1%. Median overall survival (OS) time was 3.26 and 1.04 years, respectively (P = .52). Median cause-specific survival (CSS) was 6.15 and 1.04 years, respectively (P = .21). Fifty-six percent of patients with CgA less than 1% died of prostate cancer compared with 90% of those with CgA more than 1% (P = .059). There were no significant differences in sites of metastatic disease or administration of systemic therapies. CONCLUSIONS: No significant differences in OS and CSS were observed based on NED detected by CgA. Reduced median survival time and increased cancer-related death in cases with focal NED generates the hypothesis of inferior outcomes among patients with documented DM.

Cell Type-specific Adaptive Signaling Responses to KRASG12C Inhibition.

PURPOSE: Covalent inhibitors of KRASG12C specifically target tumors driven by this form of mutant KRAS, yet early studies show that bypass signaling drives adaptive resistance. Although several combination strategies have been shown to improve efficacy of KRASG12C inhibitors (KRASi), underlying mechanisms and predictive strategies for patient enrichment are less clear. EXPERIMENTAL DESIGN: We performed mass spectrometry-based phosphoproteomics analysis in KRASG12C cell lines after short-term treatment with ARS-1620. To understand signaling diversity and cell type-specific markers, we compared proteome and phosphoproteomes of KRASG12C cells. Gene expression patterns of KRASG12C cell lines and lung tumor tissues were examined. RESULTS: Our analysis suggests cell type-specific perturbation to ERBB2/3 signaling compensates for repressed ERK and AKT signaling following ARS-1620 treatment in epithelial cell type, and this subtype was also more responsive to coinhibition of SHP2 and SOS1. Conversely, both high basal and feedback activation of FGFR or AXL signaling were identified in mesenchymal cells. Inhibition of FGFR signaling suppressed feedback activation of ERK and mTOR, while AXL inhibition suppressed PI3K pathway. In both cell lines and human lung cancer tissues with KRASG12C, we observed high basal ERBB2/3 associated with epithelial gene signatures, while higher basal FGFR1 and AXL were observed in cells/tumors with mesenchymal gene signatures. CONCLUSIONS: Our phosphoproteomic study identified cell type-adaptive responses to KRASi. Markers and targets associated with ERBB2/3 signaling in epithelial subtype and with FGFR1/AXL signaling in mesenchymal subtype should be considered in patient enrichment schemes with KRASi.

Clonally expanded, GPR15-expressing pathogenic effector TH2 cells are associated with eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is an allergic disorder characterized by the recruitment of eosinophils to the esophagus, resulting in chronic inflammation. We sought to understand the cellular populations present in tissue biopsies of patients with EoE and to determine how these populations are altered between active disease and remission. To this end, we analyzed cells obtained from esophageal biopsies, duodenal biopsies, and peripheral blood of patients with EoE diagnosed with active disease or remission with single-cell RNA and T cell receptor (TCR) sequencing. Pathogenic effector TH2 (peTH2) cells present in the esophageal biopsies of patients with active disease expressed distinct gene signatures associated with the synthesis of eicosanoids. The esophageal tissue-resident peTH2 population also exhibited clonal expansion, suggesting antigen-specific activation. Peripheral CRTH2+CD161- and CRTH2+CD161+ memory CD4+ T cells were enriched for either a conventional TH2 phenotype or a peTH2 phenotype, respectively. These cells also exhibited substantial clonal expansion and convergence of TCR sequences, suggesting that they are expanded in response to a defined set of antigens. The esophagus-homing receptor GPR15 was up-regulated by peripheral peTH2 clonotypes that were also detected in the esophagus. Finally, GPR15+ peTH2 cells were enriched among milk-reactive CD4+ T cells in patients with milk-triggered disease, suggesting that these cells are an expanded, food antigen-specific population with enhanced esophagus homing potential.

Screening of antimicrobial agents for in vitro radiation protection and mitigation capacity, including those used in supportive care regimens for bone marrow transplant recipients.

Antibiotic and antifungal agents used in supportive care regimens for bone marrow transplantation recipients contribute to a significant dose-modifying effect of otherwise lethal total body irradiation. To determine whether drugs used in supportive care and other commonly used antibiotics such as tetracycline function as radiation protectors or damage mitigators in vitro, 13 drugs were tested for radiation protection and radiation damage mitigation of 32D cl 3 hematopoietic progenitor cells in clonagenic survival curves in vitro. Antibiotic/Antifungal agents including cilastatin, amikacin, ceftazidine, vancomycin, tetracycline, doxycycline, ciprofloxacin, metronidazole, methacycline, minocycline, meclocycline, oxytetracycline and rolitetracycline were added in 1, 10, or 100 micromolar concentrations to murine interleukin-3-dependent hematopoietic progenitor cell line 32D cl 3 cells either before or after irradiation of 0 to 8 Gy. Control irradiated 32D cl 3 cells showed radiosensitivity comparable to freshly explanted mouse marrow hematopoietic progenitor cells (D(0) 1.1+/-0.1 Gy, N 1.5+/-0.4). Positive control GS-nitroxide JP4-039 (known radiation mitigator) treated 32D cl 3 cells were radioresistant (D(0) 1.2+/-0.1, N 5.8+/-2.4 (p=0.009)). Of the 13 drugs tested, tetracycline was found to be a significant radiation mitigator (D(0) 0.9+/-0.1, N 13.9+/-0.4 (p=0.0027)). Thus, the radiation dose-modifying effect of some antibiotics, but not those currently used in the supportive care (antibiotic/antifungal regimens) for marrow transplant patients, may act as radiation damage mitigators for hematopoietic cells as well as decreasing the growth and inflammatory response to microbial pathogens.

Understanding cognitive performance during exercise in Reserve Officers' Training Corps: establishing the executive function-exercise intensity relationship.

Military performance depends on high-level cognition, specifically executive function (EF), while simultaneously performing strenuous exercise. However, most studies examine cognitive performance following, not during, exercise. Therefore, our aim was to examine the relationship between EF and exercise intensity. Following familiarization, 13 Reserve Officers' Training Corp cadets (age = 19.6 ± 2 yr, five women) completed a graded exercise test (GxT) and two executive function exercise tests (EFETs) separated by a duration of ≥24 h. The EFET was a combined iPad-based EF test (Cedar Operator Workload Assessment Tool) and GxT. Heart rate (HR) and prefrontal cortex (PFC) oxygenation [near-infrared spectroscopy (NIRS)] were continuously recorded. The EF score was analyzed for accuracy of responses (%hit rate). Heart rate reserve was calculated to normalize exercise intensity (%HRR). For PFC oxygenation recordings, NIRS variables were used to calculate the tissue saturation index (%TSI). Data from EFET trials were averaged into a singular response. The %hit rate declined at heart rate reserves (HRRs) of ≥80%, reaching nadir at 100% HRR (74.09 ± 10.63%, P < 0.01). The tissue saturation index (TSI) followed a similar pattern, declining at ≥70% of HRR and at a greater rate during EFET compared with during GxT (P < 0.01), reaching a nadir in both conditions at 100% HRR (60.39 ± 2.94 vs. 63.13 ± 3.16%, P < 0.01). Therefore, EF decline is dependent on exercise intensity, as is %TSI. These data suggest that reductions in EF during high-intensity exercise are at least in part related to attenuated PFC oxygenation. Thus, interventions that improve PFC oxygenation may improve combined exercise and EF performance.NEW & NOTEWORTHY The executive functioning aspect of cognition was evaluated during graded exercise in Reserve Officers' Training Corps cadets. Executive function declined at exercise intensities of ≥80% of heart rate reserve. The decline in executive function was coupled with declines in the oxygenation of the prefrontal cortex, the brain region responsible for executive functioning. These data define the executive function-exercise intensity relationship and provide evidence supporting the reticular activation hypofrontality theory as a model of cognitive change.

The High Precision of Functional and Neuromuscular Measures to Classify Sarcopenia in Older Women.

BACKGROUND AND PURPOSE: Previous literature suggests that reductions in appendicular skeletal mass (ASM) may have a greater detrimental effect than total lean body mass regarding the onset and progression of sarcopenia. Unfortunately, limited access to equipment that accurately determines ASM often leads to many individuals remaining undiagnosed and experiencing functional decline. Therefore, the purpose of this investigation was to determine the ability of functional and neuromuscular measures to identify ASM in older women. METHODS: Forty-one (sarcopenic n = 15) older women underwent body composition analysis via dual-energy X-ray absorptiometry (DXA) and performed the following measures: bench press (BP) 1-repetition maximum strength (1RM), vertical jump height and power, handgrip strength, Timed Up and Go test, Berg Balance Scale testing, and bench press power testing at 20%, 40%, and 60% 1RM. RESULTS AND DISCUSSION: Regression analyses revealed 3 significant models accounting for 93.8%, 91.1%, and 86.4% of the variance in DXA-derived ASM. Paired-samples t tests revealed no significant differences between model-derived and DXA-derived ASM for each model, and each model was significantly correlated to DXA-derived ASM (P < .001). In addition, each model revealed a strong ability to appropriately classify sarcopenia status, with the area under the curve values ranging from 0.86 to 0.93. The present data indicate that ASM can be determined with high precision by measuring outcome variables such as jump power, body weight, and grip strength in older women. CONCLUSIONS: Therefore, the present models could be used to identify, screen, or classify older women as sarcopenic, ultimately allowing the implementation of interventions aimed at decreasing the difficulty of activities of daily living and increasing quality of life.

SHOULDER EXTERNAL ROTATOR STRENGTH IN RESPONSE TO VARIOUS SITTING POSTURES: A CONTROLLED LABORATORY STUDY.

BACKGROUND: The forward head rounded shoulder (FHRS) sitting posture has been associated with decreased shoulder complex muscle strength and function. Upon clinical observation, the adverse effects of the FHRS sitting posture on shoulder complex isometric muscle strength is also present when testing controls for scapular position. HYPOTHESIS/PURPOSE: The purpose of the study was to assess the effect of various sitting postures on shoulder external rotator muscle isometric strength when the strength testing controls for scapular position. STUDY DESIGN: A cohort study, with subjects serving as their own controls. METHODS: One hundred subjects ages 20-26 participated in the study. Each subject was placed in a neutral cervical sitting (NCS) posture which was maintained for five minutes after which the strength of the dominant shoulder external rotators was immediately tested with the glenohumeral joint in the neutral position using a Micro-FET3 Hand Held Muscle Testing Dynamometer (HHMTD). Each subject was returned to the NCS posture for subsequent external rotator strength testing after five minutes in a FHRS sitting posture, five additional minutes in the NCS posture and five minutes in a retracted cervical sitting (RCS) posture resulting in each subjects' external rotator strength being tested on four occasions. Subjects were randomized for order between the FHRS and RCS postures. RESULTS: Mean strength values for each condition were normalized to the mean strength value for the 1st NCS condition for each subject. A statistically significant decline in shoulder external rotator strength following the FHRS sitting posture occurred compared to the appropriate postural conditions (p<.05). A frequency analysis revealed that 36% of the subjects demonstrated greater than 10% decline in external rotator strength following five minutes in the FHRS sitting posture. The average percentage of strength decline in those with greater than a 10% reduction in external rotator strength was 19%. Sixty-four percent of the subjects experienced less than a 10% decline in shoulder external rotator strength in response to the FHRS sitting posture. CONCLUSION: Shoulder external rotator strength declined 8% following five minutes in the FHRS sitting posture. A sub-population of 36% demonstrated an average decline of 19% in shoulder external rotator strength following five minutes in the FHRS sitting posture. The strength decline appears to resolve over the short-term by returning to the NCS posture. LEVEL OF EVIDENCE: Level III.

Cell proliferation and vascularization in mouse models of pituitary hormone deficiency.

Mutations in the transcription factors PIT1 (pituitary transcription factor 1) and PROP1 (prophet of Pit1) lead to pituitary hormone deficiency and hypopituitarism in mice and humans. To determine the basis for this, we performed histological analysis of Pit1- and Prop1-deficient dwarf mouse pituitaries throughout fetal and postnatal development. Pit1-deficient mice first exhibit pituitary hypoplasia after birth, primarily caused by reduced cell proliferation, although there is some apoptosis. To determine whether altered development of the vascular system contributes to hypopituitarism, we examined vascularization from embryonic d 14.5 and throughout development. No obvious differences in vascularization are evident in developing Pit1-deficient pituitaries. In contrast, the Prop1-deficient mouse pituitaries are poorly vascularized and dysmorphic, with a striking elevation in apoptosis. At postnatal d 11, apoptosis-independent caspase-3 activation occurs in thyrotropes and somatotropes of normal but not mutant pituitaries. This suggests that Prop1 and/or Pit1 may be necessary for caspase-3 expression. These studies provide further insight as to the mechanisms of Prop1 and Pit1 action in mice.

Role of PROP1 in pituitary gland growth.

Mutations in the PROP1 transcription factor gene lead to reduced production of thyrotropin, GH, prolactin, and gonadotropins as well as to pituitary hypoplasia in adult humans and mice. Some PROP1-deficient patients initially exhibit pituitary hyperplasia that resolves to hypoplasia. To understand this feature and to explore the mechanism whereby PROP1 regulates anterior pituitary gland growth, we carried out longitudinal studies in normal and Prop1-deficient dwarf mice from early embryogenesis through adulthood, examining the volume of Rathke's pouch and its derivatives, the position and number of dividing cells, the rate of apoptosis, and cell migration by pulse labeling. The results suggest that anterior pituitary progenitors normally leave the perilumenal region of Rathke's pouch and migrate to form the anterior lobe as they differentiate. Some of the cells that seed the anterior lobe during organogenesis have proliferative potential, supporting the expansion of the anterior lobe after birth. Prop1-deficient fetal pituitaries are dysmorphic because mutant cells are retained in the perilumenal area and fail to differentiate. After birth, mutant pituitaries exhibit enhanced apoptosis and reduced proliferation, apparently because the mutant anterior lobe is not seeded with progenitors. These studies suggest a mechanism for Prop1 action and an explanation for some of the clinical findings in human patients.

Changes in Pulmonary Function Following Image-Guided Stereotactic Lung Radiotherapy: Neither Lower Baseline Nor Post-SBRT Pulmonary Function Are Associated with Worse Overall Survival.

PURPOSE: To determine changes in pulmonary function brought about by lung stereotactic body radiation therapy (SBRT). METHODS: One hundred and twenty-seven patients were treated with lung SBRT using 48 to 60Gy in four to five fractions on a prospective trial. We obtained pulmonary function tests (PFTs) at baseline, 6 weeks, 3 months, 6 months, 9 months, 12 months, and 24 months after SBRT. Group mean PFT parameter values are reported. RESULTS: At baseline forced expiratory volume in 1 second (FEV1) was 1.5 l (67% predicted, range: 0.4-3.4 l), corrected diffusing capacity for carbon monoxide was 12.2 ml/min/mmHg (50.8% predicted, range: 3.3-27.2 ml/min/mmHg), and total lung capacity was 5.7 l (102.4% predicted, range: 3.1-9.1 l). At 12 months, there was decline in FEV1 (-4.1%; p = 0.01), corrected diffusing capacity for carbon monoxide (-5.2%; p = 0.027), forced vital capacity (-5.7%; p = 0.004), and total lung capacity (-3.6%; p = 0.039). Declines in FEV1 (-7.6%; p = 0.001) and forced vital capacity (-8.9%; p = 0.001) persisted at 24 months. Rates of pneumonitis were 3.1% and 0.8% for grades 2 and 3, respectively. There were no grade 3 PFT toxicities at 12 months. Lower PFTs at baseline and 1 year after SBRT did not predict for worse overall survival. CONCLUSIONS: As the largest cohort of patients with prospective follow-up PFT evaluation after lung SBRT, this supports the safety of SBRT in this population of predominantly medically inoperable patients. While statistically significant, nearly all declines in PFTs would be rated as a grade 1 on the Radiation Therapy Oncology Group scale, demonstrating safety. PFT declines were not associated with worse overall survival.