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Effectiveness of a universal, school-based, online programme for the prevention of anxiety, depression, and substance misuse among adolescents in Australia: 72-month outcomes from a cluster-randomised controlled trial. Lancet Digit Health 2024; 6:e334-e344. [PMID: 38670742 DOI: 10.1016/s2589-7500(24)00046-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 02/26/2024] [Accepted: 02/29/2024] [Indexed: 04/28/2024]
Abstract
BACKGROUND The CSC study found that the universal delivery of a school-based, online programme for the prevention of mental health and substance use disorders among adolescents resulted in improvements in mental health and substance use outcomes at 30-month follow-up. We aimed to compare the long-term effects of four interventions-Climate Schools Combined (CSC) mental health and substance use, Climate Schools Substance Use (CSSU) alone, Climate Schools Mental Health (CSMH) alone, and standard health education-on mental health and substance use outcomes among adolescents at 72-month follow-up into early adulthood. METHODS This long-term study followed up adolescents from a multicentre, cluster-randomised trial conducted across three states in Australia (New South Wales, Queensland, and Western Australia) enrolled between Sept 1, 2013, and Feb 28, 2014, for up to 72 months after baseline assessment. Adolescents (aged 18-20 years) from the original CSC study who accepted contact at 30-month follow-up and provided informed consent at 60-month follow-up were eligible. The interventions were delivered in school classrooms through an online delivery format and used a mixture of peer cartoon storyboards and classroom activities that were focused on alcohol, cannabis, anxiety, and depression. Participants took part in two web-based assessments at 60-month and 72-month follow-up. Primary outcomes were alcohol use, cannabis use, anxiety, and depression, measured by self-reported surveys and analysed by intention to treat (ie, in all students who were eligible at baseline). This trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12613000723785), including the extended follow-up study. FINDINGS Of 6386 students enrolled from 71 schools, 1556 (24·4%) were randomly assigned to education as usual, 1739 (27·2%) to CSSU, 1594 (25·0%) to CSMH, and 1497 (23·4%) to CSC. 311 (22·2%) of 1401 participants in the control group, 394 (26·4%) of 1495 in the CSSU group, 477 (37·%) of 1289 in the CSMH group, and 400 (32·5%) of 1232 in the CSC group completed follow-up at 72 months. Adolescents in the CSC group reported slower year-by-year increases in weekly alcohol use (odds ratio 0·78 [95% CI 0·66-0·92]; p=0·0028) and heavy episodic drinking (0·69 [0·58-0·81]; p<0·0001) than did the control group. However, significant baseline differences between groups for drinking outcomes, and no difference in the predicted probability of weekly or heavy episodic drinking between groups were observed at 72 months. Sensitivity analyses increased uncertainty around estimates. No significant long-term differences were observed in relation to alcohol use disorder, cannabis use, cannabis use disorder, anxiety, or depression. No adverse events were reported during the trial. INTERPRETATION We found some evidence that a universal online programme for the prevention of anxiety, depression, and substance use delivered in early adolescence is effective in reducing the use and harmful use of alcohol into early adulthood. However, confidence in these findings is reduced due to baseline differences, and we did not see a difference in the predicted probability of drinking between groups at 72-month follow-up. These findings suggest that a universal prevention programme in adolescence is not sufficient to have lasting effects on mental health and substance use disorders in the long term. In addition to baseline differences, substantial attrition warrants caution in interpretation and the latter factor highlights the need for future long-term follow-up studies to invest in strategies to increase engagement. FUNDING Australian National Health and Medical Research Council.
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Clinical supervision in medical education: A citation analysis. MEDICAL TEACHER 2024; 46:505-511. [PMID: 37949084 DOI: 10.1080/0142159x.2023.2257375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
PURPOSE Medical education relies on clinical supervision for critical functions, including trainee assessment and ensuring patient safety. Yet, there is substantial variance in supervision, which has led to calls for a shared definition of the concept and guidelines to inform practice. AMEE Guide No. 27 provided these desired elements and is highly cited, suggesting that translation and utilization of the Guide's knowledge is suboptimal. This study investigates utilization by systematically characterizing citations to the Guide and by describing translation of its recommendations in relation to supervision. MATERIALS AND METHODS Citations were identified using Web of Science, Scopus, and Google Scholar. The authors coded all citations and conducted a subanalysis of studies specific to supervision. RESULTS 583 studies were identified; 268 met inclusion criteria for general analysis of which 167 studies were further analyzed. Most studies reiterated the Guide's characterization of effective supervision, but few demonstrate how these recommendations inform innovations in supervisory practice. CONCLUSION Translation of the Guide's recommendations regarding clinical supervision appears limited. Future research should consider the extent of knowledge translation occurring in clinical supervision literature as well as AMEE Guides. Increased attention to knowledge translation in medical education may benefit the distribution of similar knowledge products.
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CLPB disaggregase dysfunction impacts the functional integrity of the proteolytic SPY complex. J Cell Biol 2024; 223:e202305087. [PMID: 38270563 PMCID: PMC10818064 DOI: 10.1083/jcb.202305087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 11/07/2023] [Accepted: 12/21/2023] [Indexed: 01/26/2024] Open
Abstract
CLPB is a mitochondrial intermembrane space AAA+ domain-containing disaggregase. CLPB mutations are associated with 3-methylglutaconic aciduria and neutropenia; however, the molecular mechanism underscoring disease and the contribution of CLPB substrates to disease pathology remains unknown. Interactions between CLPB and mitochondrial quality control (QC) factors, including PARL and OPA1, have been reported, hinting at dysregulation of organelle QC in disease. Utilizing proteomic and biochemical approaches, we show a stress-specific aggregation phenotype in a CLPB-null environment and define the CLPB substrate profile. We illustrate an interplay between intermembrane space proteins including CLPB, HAX1, HTRA2, and the inner membrane quality control proteins (STOML2, PARL, YME1L1; SPY complex), with CLPB deficiency impeding SPY complex function by virtue of protein aggregation in the intermembrane space. We conclude that there is an interdependency of mitochondrial QC components at the intermembrane space/inner membrane interface, and perturbations to this network may underscore CLPB disease pathology.
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Human Tim8a, Tim8b and Tim13 are auxiliary assembly factors of mature Complex IV. EMBO Rep 2023:e56430. [PMID: 37272231 PMCID: PMC10398661 DOI: 10.15252/embr.202256430] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 05/11/2023] [Accepted: 05/16/2023] [Indexed: 06/06/2023] Open
Abstract
Human Tim8a and Tim8b are paralogous intermembrane space proteins of the small TIM chaperone family. Yeast small TIMs function in the trafficking of proteins to the outer and inner mitochondrial membranes. This putative import function for hTim8a and hTim8b has been challenged in human models, but their precise molecular function(s) remains undefined. Likewise, the necessity for human cells to encode two Tim8 proteins and whether any potential redundancy exists is unclear. We demonstrate that hTim8a and hTim8b function in the assembly of cytochrome c oxidase (Complex IV). Using affinity enrichment mass spectrometry, we define the interaction network of hTim8a, hTim8b and hTim13, identifying subunits and assembly factors of the Complex IV COX2 module. hTim8-deficient cells have a COX2 and COX3 module defect and exhibit an accumulation of the Complex IV S2 subcomplex. These data suggest that hTim8a and hTim8b function in assembly of Complex IV via interactions with intermediate-assembly subcomplexes. We propose that hTim8-hTim13 complexes are auxiliary assembly factors involved in the formation of the Complex IV S3 subcomplex during assembly of mature Complex IV.
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Patient-reported outcome measures for paediatric acute lower respiratory infection studies. Eur Respir Rev 2023; 32:32/167/220229. [PMID: 36889787 PMCID: PMC10032589 DOI: 10.1183/16000617.0229-2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/17/2023] [Indexed: 03/10/2023] Open
Abstract
BACKGROUND Patient-reported outcome measures (PROMs) are recommended for capturing meaningful outcomes in clinical trials. The use of PROMs for children with acute lower respiratory infections (ALRIs) has not been systematically reported. We aimed to identify and characterise patient-reported outcomes and PROMs used in paediatric ALRI studies and summarise their measurement properties. METHODS Medline, Embase and Cochrane were searched (until April 2022). Studies that reported on patient-reported outcome (or measure) use or development and included subjects aged <18 years with ALRIs were included. Study, population and patient-reported outcome (or measure) characteristics were extracted. RESULTS Of 2793 articles identified, 18 met inclusion criteria, including 12 PROMs. Two disease-specific PROMs were used in settings in which they had been validated. The Canadian Acute Respiratory Illness and Flu Scale was the most frequently used disease-specific PROM (five studies). The EuroQol-Five Dimensions-Youth system was the most frequently used generic PROM (two studies). There was considerable heterogeneity in validation methods. The outcome measures identified in this review lack validation for young children and none involve sufficient content validity for use with First Nations children. CONCLUSIONS There is an urgent need for PROM development that considers the populations in which the burden of ALRI predominates.
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Mitochondrial biology and dysfunction in secondary mitochondrial disease. Open Biol 2022; 12:220274. [PMID: 36475414 PMCID: PMC9727669 DOI: 10.1098/rsob.220274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial diseases are a broad, genetically heterogeneous class of metabolic disorders characterized by deficits in oxidative phosphorylation (OXPHOS). Primary mitochondrial disease (PMD) defines pathologies resulting from mutation of mitochondrial DNA (mtDNA) or nuclear genes affecting either mtDNA expression or the biogenesis and function of the respiratory chain. Secondary mitochondrial disease (SMD) arises due to mutation of nuclear-encoded genes independent of, or indirectly influencing OXPHOS assembly and operation. Despite instances of novel SMD increasing year-on-year, PMD is much more widely discussed in the literature. Indeed, since the implementation of next generation sequencing (NGS) techniques in 2010, many novel mitochondrial disease genes have been identified, approximately half of which are linked to SMD. This review will consolidate existing knowledge of SMDs and outline discrete categories within which to better understand the diversity of SMD phenotypes. By providing context to the biochemical and molecular pathways perturbed in SMD, we hope to further demonstrate the intricacies of SMD pathologies outside of their indirect contribution to mitochondrial energy generation.
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Premature Ovarian Insufficiency in CLPB Deficiency: Transcriptomic, Proteomic and Phenotypic Insights. J Clin Endocrinol Metab 2022; 107:3328-3340. [PMID: 36074910 PMCID: PMC9693831 DOI: 10.1210/clinem/dgac528] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Indexed: 11/19/2022]
Abstract
CONTEXT Premature ovarian insufficiency (POI) is a common form of female infertility that usually presents as an isolated condition but can be part of various genetic syndromes. Early diagnosis and treatment of POI can minimize comorbidity and improve health outcomes. OBJECTIVE We aimed to determine the genetic cause of syndromic POI, intellectual disability, neutropenia, and cataracts. METHODS We performed whole-exome sequencing (WES) followed by functional validation via RT-PCR, RNAseq, and quantitative proteomics, as well as clinical update of previously reported patients with variants in the caseinolytic peptidase B (CLPB) gene. RESULTS We identified causative variants in CLPB, encoding a mitochondrial disaggregase. Variants in this gene are known to cause an autosomal recessive syndrome involving 3-methylglutaconic aciduria, neurological dysfunction, cataracts, and neutropenia that is often fatal in childhood; however, there is likely a reporting bias toward severe cases. Using RNAseq and quantitative proteomics we validated causation and gained insight into genotype:phenotype correlation. Clinical follow-up of patients with CLPB deficiency who survived to adulthood identified POI and infertility as a common postpubertal ailment. CONCLUSION A novel splicing variant is associated with CLPB deficiency in an individual who survived to adulthood. POI is a common feature of postpubertal female individuals with CLPB deficiency. Patients with CLPB deficiency should be referred to pediatric gynecologists/endocrinologists for prompt POI diagnosis and hormone replacement therapy to minimize associated comorbidities.
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Vibrational spectroscopic analysis of blood for diagnosis of infections and sepsis: a review of requirements for a rapid diagnostic test. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2021; 13:157-168. [PMID: 33284291 DOI: 10.1039/d0ay01991g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Infections and sepsis represent a growing global burden. There is a widespread clinical need for a rapid, high-throughput and sensitive technique for the diagnosis of infections and detection of invading pathogens and the presence of sepsis. Current diagnostic methods primarily consist of laboratory-based haematology, biochemistry and microbiology that are time consuming, labour- and resource-intensive, and prone to both false positive and false negative results. Current methods are insufficient for the increasing demands on healthcare systems, causing delays in diagnosis and initiation of treatment, due to the intrinsic time delay in sample preparation, measurement, and analysis. Vibrational spectroscopic techniques can overcome these limitations by providing a rapid, label-free and low-cost method for blood analysis, with limited sample preparation required, potentially revolutionising clinical diagnostics by producing actionable results that enable early diagnosis, leading to improved patient outcomes. This review will discuss the challenges associated with the diagnosis of infections and sepsis, primarily within the UK healthcare system. We will consider the clinical potential of spectroscopic point-of-care technologies to enable blood analysis in the primary-care setting.
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Liquid biopsy for cancer diagnosis using vibrational spectroscopy: systematic review. BJS Open 2020; 4:554-562. [PMID: 32424976 PMCID: PMC7397350 DOI: 10.1002/bjs5.50289] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 03/23/2020] [Indexed: 02/06/2023] Open
Abstract
Background Vibrational spectroscopy (VS) is a minimally invasive tool for analysing biological material to detect disease. This study aimed to review its application to human blood for cancer diagnosis. Methods A systematic review was undertaken using a keyword electronic database search (MEDLINE, Embase, PubMed, TRIP and Cochrane Library), with all original English‐language manuscripts examining the use of vibrational spectral analysis of human blood for cancer detection. Studies involving fewer than 75 patients in the cancer or control group, animal studies, or where the primary analyte was not blood were excluded. Results From 1446 results, six studies (published in 2010–2018) examining brain, bladder, oral, breast, oesophageal and hepatic cancer met the criteria for inclusion, with a total population of 2392 (1316 cancer, 1076 control; 1476 men, 916 women). For cancer detection, reported mean sensitivities in each included study ranged from 79·3 to 98 per cent, with specificities of 82·8–95 per cent and accuracies between 81·1 and 97·1 per cent. Heterogeneity in reporting strategies, methods and outcome measures made meta‐analysis inappropriate. Conclusion VS shows high potential for cancer diagnosis, but until there is agreement on uniform standard reporting methods and studies with adequate sample size for valid classification models have been performed, its value in clinical practice will remain uncertain.
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Biofluid infrared spectro-diagnostics: pre-analytical considerations for clinical applications. Faraday Discuss 2018; 187:521-37. [PMID: 27048927 DOI: 10.1039/c5fd00184f] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Several proof-of-concept studies on the vibrational spectroscopy of biofluids have demonstrated that the methodology has promising potential as a clinical diagnostic tool. However, these studies also show that there is a lack of a standardised protocol in sample handling and preparation prior to spectroscopic analysis. One of the most important sources of analytical errors is the pre-analytical phase. For the technique to be translated into clinics, it is clear that a very strict protocol needs to be established for such biological samples. This study focuses on some of the aspects of the pre-analytical phase in the development of the high-throughput Fourier Transform Infrared (FTIR) spectroscopy of some of the most common biofluids such as serum, plasma and bile. Pre-analytical considerations that can impact either the samples (solvents, anti-coagulants, freeze-thaw cycles…) and/or spectroscopic analysis (sample preparation such as drying, deposit methods, volumes, substrates, operators dependence…) and consequently the quality and the reproducibility of spectral data will be discussed in this report.
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The regulation of mitochondrial DNA copy number in glioblastoma cells. Cell Death Differ 2013; 20:1644-53. [PMID: 23995230 PMCID: PMC3824586 DOI: 10.1038/cdd.2013.115] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 07/10/2013] [Accepted: 07/22/2013] [Indexed: 01/07/2023] Open
Abstract
As stem cells undergo differentiation, mitochondrial DNA (mtDNA) copy number is strictly regulated in order that specialized cells can generate appropriate levels of adenosine triphosphate (ATP) through oxidative phosphorylation (OXPHOS) to undertake their specific functions. It is not understood whether tumor-initiating cells regulate their mtDNA in a similar manner or whether mtDNA is essential for tumorigenesis. We show that human neural stem cells (hNSCs) increased their mtDNA content during differentiation in a process that was mediated by a synergistic relationship between the nuclear and mitochondrial genomes and results in increased respiratory capacity. Differentiating multipotent glioblastoma cells failed to match the expansion in mtDNA copy number, patterns of gene expression and increased respiratory capacity observed in hNSCs. Partial depletion of glioblastoma cell mtDNA rescued mtDNA replication events and enhanced cell differentiation. However, prolonged depletion resulted in impaired mtDNA replication, reduced proliferation and induced the expression of early developmental and pro-survival markers including POU class 5 homeobox 1 (OCT4) and sonic hedgehog (SHH). The transfer of glioblastoma cells depleted to varying degrees of their mtDNA content into immunocompromised mice resulted in tumors requiring significantly longer to form compared with non-depleted cells. The number of tumors formed and the time to tumor formation was relative to the degree of mtDNA depletion. The tumors derived from mtDNA depleted glioblastoma cells recovered their mtDNA copy number as part of the tumor formation process. These outcomes demonstrate the importance of mtDNA to the initiation and maintenance of tumorigenesis in glioblastoma multiforme.
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FTIR-based spectroscopic analysis in the identification of clinically aggressive prostate cancer. Br J Cancer 2008; 99:1859-66. [PMID: 18985044 PMCID: PMC2600682 DOI: 10.1038/sj.bjc.6604753] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Fourier transform infrared (FTIR) spectroscopy is a vibrational spectroscopic technique that uses infrared radiation to vibrate molecular bonds within the sample that absorbs it. As different samples contain different molecular bonds or different configurations of molecular bonds, FTIR allows us to obtain chemical information on molecules within the sample. Fourier transform infrared microspectroscopy in conjunction with a principal component-discriminant function analysis (PC-DFA) algorithm was applied to the grading of prostate cancer (CaP) tissue specimens. The PC-DFA algorithm is used alongside the established diagnostic measures of Gleason grading and the tumour/node/metastasis system. Principal component-discriminant function analysis improved the sensitivity and specificity of a three-band Gleason score criterion diagnosis previously reported by attaining an overall sensitivity of 92.3% and specificity of 99.4%. For the first time, we present the use of a two-band criterion showing an association of FTIR-based spectral characteristics with clinically aggressive behaviour in CaP manifest as local and/or distal spread. This paper shows the potential for the use of spectroscopic analysis for the evaluation of the biopotential of CaP in an accurate and reproducible manner.
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Abstract
Carcass traits have been successfully used to determine body composition of steers. Body composition, in turn, has been used to predict energy content of ADG to compute feed requirements of individual animals fed in groups. This information is used in the Cornell value discovery system (CVDS) to predict DM required (DMR) for the observed animal performance. In this experiment, the prediction of individual DMR for the observed performance of group-fed yearling bulls was evaluated using energy content of gain, which was based on ultrasound measurements to estimate carcass traits and energy content of ADG. One hundred eighteen spring-born purebred and crossbred bulls (BW = 288 +/- 4.3 kg) were sorted visually into 3 marketing groups based on estimated days to reach USDA low Choice quality grade. The bulls were fed a common high-concentrate diet in 12 slatted-floor pens (9 to 10 head/pen). Ultrasound measurements including back-fat (uBF), rump fat, LM area (uLMA), and intramuscular fat were taken at approximately 1 yr of age. Carcass measurements including HCW, backfat over the 12th to 13th rib (BF), marbling score (MRB), and LM area (LMA) were collected for comparison with ultrasound data for predicting carcass composition. The 9th to 11th-rib section was removed and dissected into soft tissue and bone for determination of chemical composition, which was used to predict carcass fat and empty body fat (EBF). The predicted EBF averaged 23.7 +/- 4.0%. Multiple regression analysis indicated that carcass traits explained 72% of the variation in predicted EBF (EBF = 16.0583 + 5.6352 x BF + 0.01781 x HCW + 1.0486 x MRB - 0.1239 x LMA). Because carcass traits are not available on bulls intended for use as herd sires, another equation using predicted HCW (pHCW) and ultrasound measurements was developed (EBF = 39.9535 x uBF - 0.1384 x uLMA + 0.0867 x pHCW - 0.0897 x uBF x pHCW - 1.3690). This equation accounted for 62% of the variation in EBF. The use of an equation to predict EBF developed with steer composition data overpredicted the EBF predicted in these experiments (28.7 vs. 23.7%, respectively). In a validation study with 37 individually fed bulls, the use of the ultrasound-based equation in the CVDS to predict energy content of gain accounted for 60% of the variation in the observed efficiency of gain, with 1.5% bias, and identified 3 of the 4 most efficient bulls.
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Abstract
Identification of efficient animals in the postweaning growth phase for use in selection for improved feed efficiency is important to improve the economic and environmental sustainability of the beef cattle industry. Progeny testing using group-fed animals in commercial feedlots is the most common and practical method used to evaluate postweaning growth on large numbers of animals. We developed the Cornell Value Discovery System (CVDS) to dynamically predict growth rate, accumulated weight, days required to reach target body composition, carcass weight, and composition of individual beef cattle fed in group pens. Observed BW, ADG, BW at 28% empty body fat (EBF), breed type, environmental conditions, and dietary ME concentration are used by the CVDS to predict, for each animal in a pen, the feed DM required for maintenance (FFM), the feed DM required for gain, and the total DM required for maintenance and gain (DMR). The CVDS then computes DMR-to-ADG ratio (DMR:ADG), which is a feed conversion measure, and ADG-to-DMR ratio (ADG:DMR), which is a feed efficiency measure, for each animal. This study used the observed F:G ratio of 362 individually fed steers to evaluate CVDS-predicted indicators of feed efficiency and the Kleiber ratio. A subset of 37 data points was used to evaluate residual feed intake (RFI) as an indicator of feed efficiency. The database included 4 published studies, each with detailed individual animal description, environment, diet, and body composition information. The CVDS-predicted DMR:ADG accounted for 84% of the variation in the actual F:G ratio with a mean bias of 1.94% (P = 0.20). The predicted FFM to actual DMI ratio had a high correlation with actual ADG (R2 = 0.76), and indicated a decay-type nonlinear dilution of FFM as ADG increased. The CVDS-predicted ADG:DMR and the Kleiber ratio had a significant (R2 = 0.88) logarithmic relationship. In an analysis of a contemporary group within the database, RFI was highly correlated with the F:G ratio (r = 0.71). There was a positive relationship between RFI and EBF. The RFIM (DMI - DMR) was moderately correlated with DMI and ADG (0.37 and -0.38; respectively), suggesting that selecting for low RFI(M) would decrease DMI and increase ADG in this database. We conclude that the CVDS model can be used to identify differences in the F:G and G:F ratios by predicting DMR for individual growing cattle fed in groups.
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Functional and cellular adaptations of rodent skeletal muscle to weightlessness. JOURNAL OF GRAVITATIONAL PHYSIOLOGY : A JOURNAL OF THE INTERNATIONAL SOCIETY FOR GRAVITATIONAL PHYSIOLOGY 2001; 2:P39-42. [PMID: 11538926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Microgravity perturbs a wide variety of physiological systems. Specifically, skeletal muscle has been shown to undergo dramatic changes even during spaceflights of short durations. Despite a growing body of knowledge, many critical issues related to sarcomeric gene expression and the translation of this information into muscle function remain relatively unexplored. Ultimately, the types and quantities of contractile proteins present in skeletal muscle fibers determine muscle function. As shown in Figure 1, the pool of contractile proteins is determined by 4 important processes: i) transcription of sarcomeric genes; ii) translation of sarcomeric mRNA transcripts; iii) myofibrillar assembly; and iv) myofibrillar disassembly (i.e., protein degradation). Any factor(s) affecting one or more of these systems will ultimately impact skeletal muscle function. With respect to Figure 1, the objective of this paper is to provide a focused summary of the affects of short duration spaceflights on myosin composition of the soleus (SOL) muscle. This will be achieved by describing the affects of spaceflight upon: i) mechanical properties of skeletal muscle that are determined by the types and quantity of myosin; ii) myosin heavy chain (MHC) protein isoform composition; and ii) MHC mRNA isoform content. Data reported in this paper are from spaceflight missions having durations of 6 (PARE-02;2) and 14 days (SLS-2).
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Abstract
A published model designed to predict individual feed required for the observed shrunk BW and ADG of growing cattle when fed in groups was modified and evaluated to improve its accuracy. This model is needed to accurately bill feed and compute cost of gain in marketing programs based on individual animal management. Because of its importance in predicting energy required for growth, a database of 401 steers was used to develop an equation to predict percentage of empty-body fat (EBF) from carcass measurements (12th rib fat thickness, hot carcass weight, USDA quality grade, and longissimus muscle area), which accounted for 61% of the variation in EBF with no bias (P > 0.1). When tested with an independent data set of 951 steers, the equation accounted for 51% of the variation with 1% proportional bias. The large variation in the carcass measurements at a particular EBF observed in this study indicates further improvement is limited by the inability of carcass measurements to account for variation in fat distribution in the various carcass components. Because of its importance in setting the target end point, a database of 1,355 steers and heifers was used to determine the relationship between EBF and USDA quality grade. These data indicate growing and finishing cattle reach Select and low-Choice quality grades at an EBF of 26.15 +/- 0.19 and 28.61 +/- 0.20%, respectively (P < 0.05). A data set of 228 steers from different breeds from two serial slaughter studies indicated 14.26 +/- 1.52 kg of empty BW change are required to increase EBF one percentage unit for cattle fed high-energy diets; this adjustment is needed to adjust final shrunk BW to the target EBF end point. The model to predict DM required with modifications developed in this study was evaluated with data from 365 individually fed cattle and it accounted for 74% of the variation in observed DM consumed with no bias (P > 0.1). When the revised model was applied to a commercial feedlot data set containing 12,105 steers and heifers, the total observed DM consumed was predicted with a bias of less than 1%. The model presented in this study accounts for differences known to affect animal requirements (breed type, BW and ADG, and weight at the target EBF end point) and can be used to fairly allocate feed to individuals fed in a group under commercial feedlot conditions.
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Abstract
OBJECTIVE To assess the relationships between home death and a set of demographic, disease-related, and health-resource factors among individuals who died of cancer. DESIGN Prospective cohort study. SETTING All adult deaths from cancer in Connecticut during 1994. PARTICIPANTS Six thousand eight hundred and thirteen individuals who met all of the following criteria: died of a cancer-related cause in 1994, had previously been diagnosed with cancer in Connecticut, and were age 18 and older at the time of death. MEASUREMENT Site of death. RESULTS Twenty-nine percent of the study sample died at home, 42% died in a hospital, 17% died in a nursing home, and 11% died in an inpatient hospice facility. Multivariate analysis indicated that demographic characteristics (being married, female, white, and residing in a higher income area), disease-related factors (type of cancer, longer survival postdiagnosis), and health-resource factors (greater availability of hospice providers, less availability of hospital beds) were associated with dying at home rather than in a hospital or inpatient hospice. CONCLUSIONS The implications of this study for clinical practice and health planning are considerable. The findings identify groups (men, unmarried individuals, and those living in lower income areas) at higher risk for institutionalized death-groups that may be targeted for possible interventions to promote home death when home death is preferred by patients and their families. Further, the findings suggest that site of death is influenced by available health-system resources. Thus, if home death is to be supported, the relative availability of hospital beds and hospice providers may be an effective policy tool for promoting home death.
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Abstract
Chediak-Higashi syndrome (CHS) is a rare autosomal-recessive disorder characterized by immune deficiency, partial oculocutaneous albinism, and large eosinophilic, peroxidase-positive inclusion bodies in granule-containing cells. The adult form of CHS manifests during late childhood to early adulthood and is marked by various neurologic sequelae, including parkinsonism, dementia, spinocerebellar degeneration, and peripheral neuropathy. We report the case of a 29-year-old man with adult CHS who exhibited a progressive asymmetric parkinsonism, including rest tremor, and axial, cervical, and appendicular dystonia. The diagnosis was confirmed by the presence of characteristic large peroxidase-positive granules within leukocytes and markedly decreased natural killer cell function. Levodopa/carbidopa and amantadine provided benefit for tremor. CHS, although rare, should be considered in the differential diagnosis of young adult parkinsonism.
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Single-fiber myosin heavy-chain isoform composition of rodent laryngeal muscle: modulation by thyroid hormone. ARCHIVES OF OTOLARYNGOLOGY--HEAD & NECK SURGERY 2000; 126:874-80. [PMID: 10889000 DOI: 10.1001/archotol.126.7.874] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Studies have shown that canine laryngeal muscle contains a large number of muscle fibers that coexpress varying combinations of myosin heavy-chain (MyHC) isoforms. Currently, it is not clear whether this phenomenon is unique to canine laryngeal muscle or occurs in all mammals. OBJECTIVES To examine the single-fiber MyHC isoform composition of rodent laryngeal muscle and to examine the plasticity of single-fiber MyHC isoform composition via manipulation of thyroid state. RESULTS (1) Findings of single-fiber electrophoretic analyses clearly demonstrate that most fibers in both the posterior cricoarytenoid and thyroarytenoid muscles exhibit MyHC polymorphism. However, the proportions and patterns of polymorphism appear to be muscle specific. (2) Although the fast type IIL isoform was observed in fibers from both muscles, it was always coexpressed in combination with other MyHC isoforms (ie, no pure type IIL fibers were found), and always represented a minor proportion of the total MyHC pool. (3) Altering the thyroid state proved a useful tool for exploring the scope of MyHC isoform expression in these muscles. While the posterior cricoarytenoid muscle seemed more sensitive to the thyroid state, transitions in both muscles were primarily confined to the fast type IIX and IIB MyHC isoforms. CONCLUSION The findings of this study support the concept that single-fiber MyHC polymorphism occurs commonly in mammalian laryngeal muscle.
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Novel transitions in MHC isoforms: separate and combined effects of thyroid hormone and mechanical unloading. J Appl Physiol (1985) 1998; 85:2237-48. [PMID: 9843548 DOI: 10.1152/jappl.1998.85.6.2237] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Single-fiber (n = 3,818 fibers) electrophoretic analyses were used to delineate the separate and combined effects of hyperthyroidism (T3) and hindlimb suspension (HS) on the myosin heavy chain (MHC) isoform composition (1-, 2-, and 4-wk time points) of the rat soleus muscle. The key findings of this study are as follows. First, T3 and HS both altered the distribution of MHC isoforms at the single-fiber level; however, the populations of fibers produced by these two interventions were clearly different from one another. Second, T3 + HS rapidly converted the soleus into a fast muscle, producing large increases in the relative contents of the fast type IIx and IIb MHC isoforms which were primarily expressed in several populations of hybrid fibers (e.g., types I/IIa/IIx, I/IIx/IIb, I/IIa/IIx/IIb). Finally, T3 + HS produced unique populations of hybrid fibers that did not adhere to the Ileft arrow over right arrow IIaleft arrow over right arrow IIxleft arrow over right arrow IIb sequential scheme of MHC plasticity. Collectively, the findings of this study demonstrate that the intervention of T3 + HS is a powerful model for manipulating and studying MHC isoform plasticity in slow skeletal muscle.
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Do you work with local parishes? Putting patients first response. HEALTH PROGRESS (SAINT LOUIS, MO.) 1998; 79:18. [PMID: 10339223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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A new concept in laryngeal muscle: multiple myosin isoform types in single muscle fibers of the lateral cricoarytenoid. Otolaryngol Head Neck Surg 1998; 118:86-94. [PMID: 9450834 DOI: 10.1016/s0194-5998(98)70380-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This report describes the first known investigation of canine laryngeal muscle in which single fibers were dissected and their myosin heavy chain (MHC) isoform content was analyzed. Both SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and western blot techniques were used. The data from single fiber SDS-PAGE indicate that the lateral cricoarytenoid (LCA) is predominantly a fast muscle composed of the following MHC isoforms: Type I, 16.3%; Type IIA, 71.3%; Type IIX, 10.4%; and Type IIB, 2.0%. The results reveal a phenomenon that, to our knowledge, has not been previously described for laryngeal muscle: the presence of two or more MHC isoforms in a single canine LCA muscle fiber. A large number (41%) of muscle fibers coexpressed two or more MHC isoforms. The three most common patterns of coexpression were Type IIA/IIX (72%), Type IIA/I (16%), and Type IIA/IIX/I (8%). Interestingly, the fast Type IIX MHC isoform was typically present with other isoforms and rarely found by itself in individual fibers. Additional experiments are underway to determine whether other laryngeal muscles exhibit such an unusually high ratio of MHC isoform polymorphism.
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Single-fiber and whole muscle analyses of MHC isoform plasticity: interaction between T3 and unloading. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:C944-52. [PMID: 9316416 DOI: 10.1152/ajpcell.1997.273.3.c944] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Previous data suggest that separate interventions of hyperthyroidism (T3) and hindlimb suspension (HS) act on some but not all slow type I fibers in the soleus muscle. This may be due to the presence of "refractory" fibers that are unresponsive to either of these interventions. Alternatively, T3 and HS might act on different populations of slow type I fibers in the soleus muscle. Adult female Sprague-Dawley rats were assigned to 1) control, 2) T3, 3) HS, or 4) T3+HS. Nine animals were assigned to each group. Single-fiber electrophoretic analyses (n = 40 per muscle) of the soleus muscle demonstrated that the HS reduced the percentage of slow type I fibers from approximately 80% (control) to approximately 40% (HS) of the fiber population. Although hyperthyroidism affected a greater percentage of slow type I fibers than HS, a small population (approximately 10% of the slow type I fibers) were unaffected by T3. The combined intervention, in contrast, transformed all slow type I fibers into fibers expressing various combinations of fast myosin heavy chain (MHC) isoforms. These findings demonstrate that the soleus muscle does not contain so-called refractory fibers. They further suggest that the soleus muscle contains different populations of slow type I fibers that vary in their sensitivity to altered physiological conditions.
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Evaluation of Infant Diarrhea Associated with Elevated Levels of Sulfate in Drinking Water: A Case-Control Investigation in South Dakota. INTERNATIONAL JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH 1997; 3:171-176. [PMID: 9891115 DOI: 10.1179/oeh.1997.3.3.171] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The objective of this study was to assess the association between infant diarrhea and ingestion of water containing elevated sulfate levels. The authors identified 274 mothers of infants born in 19 South Dakota counties with high water sulfate concentrations. Demographic information and seven-day- recall dietary and health data were obtained by telephone interviews. Sulfate in drinking water was measured from samples submitted by the participants. Logistic regression was used to estimate the risk for diarrhea (>/=3 loose stools in 24 hours). Questionnaires were completed for 274 households: 69% drank municipal water and 54% reported using the water in the infants' diets. Thirty-nine infants developed diarrhea. Of the 170 households that submitted water samples, 141 (83%) were using the water in the infants' diets. The median sulfate level of the water samples was 264 mg/L. Twenty-five of the infants developed diarrhea. Average infant daily sulfate intake was not significantly associated with an increased diarrhea rate. There was no significant association between sulfate ingestion and the incidence of diarrhea for the range of sulfate levels studied. There was no evidence of a dose-response or threshold effect. However, because of the small number of the most highly exposed infants, the possibility of such an association should be further evaluated.
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Abstract
This study tested for the hypothesis that mechanical loading, not stimulation frequency per se, plays a key role in determining the plasticity of myosin heavy chain (MHC) protein isoform expression in muscle undergoing resistance training. Female Sprague-Dawley rats were randomly assigned to resistance-training programs that employed active 1) shortening (n = 7) or 2) lengthening contractions (n = 8). The medial gastrocnemius (MG) muscles in each group trained under loading conditions that approximated 90-95% of maximum isometric tetanic tension but were stimulated at frequencies of 100 and approximately 25 Hz, respectively. Lengthening and shortening contractions were produced by using a Cambridge ergometer system. The MG muscles trained every other day, performing a total of 16 training session. Both training programs produced significant (P < 0.01) and similar reductions in the fast type IIB MHC protein isoform in the white MG muscle, reducing its relative content to approximately 50% of the total MHC protein isoform pool. These changes were accompanied by increases in the relative content of the fast type IIX MHC protein isoform that were of similar magnitude for both groups. The results of this study clearly demonstrate that stimulation frequency does not play a key role in modulating MHC isoform alterations that result from high-resistance training.
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Microgravity-induced transformations of myosin isoforms and contractile properties of skeletal muscle. J Appl Physiol (1985) 1996; 81:123-32. [PMID: 8828654 DOI: 10.1152/jappl.1996.81.1.123] [Citation(s) in RCA: 153] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
This study examined the effects of microgravity (14 days) on 1) the contractile properties of the soleus (Sol), an antigravity skeletal muscle; and 2) the myosin heavy chain (MHC) protein and mRNA isoform content of the Sol, vastus intermedius (VI), plantaris (Plan), and tibialis anterior (TA) muscles. The force-velocity relationships of the flight Sol muscles had a significant reduction in maximal isometric tension (-37%) and a corresponding increase in maximal shortening velocity (+20%). Additionally, the force-frequency relationship of the flight Sol muscles was shifted to the right of the ground-based control group. Microgravity had the greatest effect on muscle fiber composition in the Sol muscle, with a reduction in slow muscle fibers and a corresponding increase in muscle fibers categorized as hybrid fibers. The estimated absolute MHC isoform content was altered to the greatest extent in the Sol and VI muscles, with significant decreases and elevations in the slow type I and fast type IIX MHC protein isoforms, respectively. Consistent with the protein data, both the flight Sol and VI muscles exhibited significant elevations in the fast type IIX MHC mRNA isoform. In contrast, however, the flight Plan and TA groups had significant increases in the fast type IIB MHC mRNA isoform content without corresponding changes at the protein level. The results of this study suggest that spaceflight of even short duration produces important changes in the contractile properties of antigravity skeletal muscle. These changes are mediated by alterations in MHC phenotype and reductions in muscle mass. In some instances, the alterations in MHC mRNA isoform content seemed to be uncoupled from those occurring at the protein level. This apparent uncoupling between mRNA and protein expression demonstrates that the effects of microgravity must be better understood at the transcriptional, translational, and post-translational levels.
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Abstract
The overall objective of the studies reported herein was to examine the effects of high-resistance training on myosin heavy-chain (MHC) protein and mRNA isoform expression. The findings from these studies can be summarized as follows: 1) there was a substantial increase in the fast type IIX MHC protein isoform content of the trained red and white medial gastrocnemius muscles, but this did not occur until after the eighth training session (i.e., 16 days); 2) single-fiber analyses demonstrated that many so-called fast type IIB fibers contained small amounts of the fast type IIX MHC protein isoform and that the high-resistance training program altered the bias of fast type IIB-type IIX MHC protein isoform distribution in these fibers but did not increase the number of fibers that could be categorized as exclusively fast type IIX fibers; 3) the high-resistance training program produced a rapid (i.e., after two training sessions) elevation in the fast type IIX MHC mRNA isoform and a corresponding repression of the fast type IIB MHC mRNA isoform; and 4) the dose-response study revealed that as few as 10 contractions (40 s) per training session were capable of elevating the expression of the fast type IIX MHC mRNA isoform by approximately 250%. These collective findings demonstrate that high-resistance training is a powerful modulator of MHC protein isoforms and that pretranslational mechanisms are very sensitive to even small amounts of high-resistance training.
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Recent trends in the use of inhaled beta 2-adrenergic agonists and inhaled corticosteroids in Saskatchewan. CMAJ 1995; 153:1437-43. [PMID: 7585370 PMCID: PMC1487449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVE To examine recent trends in the use of inhaled beta 2-adrenergic agonists and inhaled corticosteroids for the treatment of asthma among Saskatchewan residents and to determine whether these trends are in keeping with widely publicized guidelines recommending a reduction in the use of agents to treat symptoms (i.e., inhaled beta 2-adrenergic agonists) and increased use of prophylactic agents (i.e., inhaled corticosteroids). DESIGN Descriptive pharmacoepidemiologic study conducted with the use of data from the computerized database of the Saskatchewan Prescription Drug Plan. SETTING Saskatchewan. PATIENTS Saskatchewan residents 5 to 54 years of age who received one or more outpatient prescriptions for drugs to treat asthma (inhaled drugs, ingested beta 2-adrenergic agonists and ingested methylxanthines) from 1989 to 1993. OUTCOME MEASURES Epidemiologic trends, calculated for each year: number of prescriptions per 1,000 persons; number of patients who received prescriptions for inhaled corticosteroids, inhaled beta 2-adrenergic agonists and any type of drug to treat asthma; mean number of such prescriptions per patient; and weighted mean amount of salbutamol, fenoterol and beclomethasone dispensed per patient. RESULTS There has been an increase in the proportion of the population receiving prescriptions for drugs to treat asthma. The number of patients receiving these drugs per 1,000 people rose during the study period from 33.38 to 46.59 for any drug to treat asthma, from 24.70 to 33.77 for inhaled beta 2-adrenergic agonists and from 6.1 to 19.9 for inhaled corticosteroids. The mean number of prescriptions per patient decreased steadily for all drugs to treat asthma (from 5.34 in 1989 to 3.88 in 1993), for inhaled beta 2-adrenergic agonists (from 4.35 to 3.09) and for inhaled corticosteroids (from 2.98 to 2.25). The weighted mean amount of inhaled salbutamol dispensed per patient per year decreased by 40%, from 178.08 mg in 1989 to 109.14 mg in 1993. The weighted amount of fenoterol dispensed per patient per year declined even more, by 58%, from 387.91 mg in 1989 to 164.00 mg in 1993. Conversely, the weighted amount of inhaled beclomethasone dispensed per patient per year increased by 35% from 46.95 mg in 1989 to 63.50 mg in 1992, then dropped to 56.17 mg per year in 1993. CONCLUSION These data demonstrate a substantial change in Saskatchewan in the prescribing of drugs to treat asthma; they suggest that many physicians responded to current guidelines advocating increased attention to prevention of airway inflammation in the treatment of asthma.
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Abstract
The delivery of nursing care should be based on meeting patients' individual needs. This article presents the findings of a small-scale study which explored the feelings that people express regarding the care they would like and receive from nurses.
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The effects of space flight on the contractile apparatus of antigravity muscles: implications for aging and deconditioning. JOURNAL OF GRAVITATIONAL PHYSIOLOGY : A JOURNAL OF THE INTERNATIONAL SOCIETY FOR GRAVITATIONAL PHYSIOLOGY 1994; 1:P8-11. [PMID: 11538774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Previous studies have shown that the unloading of skeletal muscle, as occurring during exposure to space flight, exerts a profound effect on both the mass (cross sectional area) of skeletal muscle fibers and the relative expression of protein isoforms comprising the contractile system. Available information suggests that slow (type I) fibers, comprising chiefly the antigravity muscles of experimental animals, in addition to atrophying, undergo alterations in the type of myosin heavy chain (MHC) expressed such that faster isoforms become concomitantly expressed in a sub-population of slow fibers when insufficient force-bearing activity is maintained on the muscle. Consequently, these transformations in both mass and myosin heavy chain phenotype could exert a significant impact on the functional properties of skeletal muscle as manifest in the strength, contractile speed, and endurance scope of the muscle. To further explore these issues, a study was performed in which young adult male rats were exposed to zero gravity for six days, following which, the antigravity soleus muscle was examined for a) contractile properties, determined in situ and b) isomyosin expression, as studied using biochemical, molecular biology, and histochemical/immunohistochemical techniques.
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MESH Headings
- Aging/physiology
- Animals
- Immunohistochemistry
- Isomerism
- Male
- Muscle Contraction/physiology
- Muscle Fibers, Fast-Twitch/metabolism
- Muscle Fibers, Fast-Twitch/pathology
- Muscle Fibers, Fast-Twitch/physiology
- Muscle Fibers, Slow-Twitch/metabolism
- Muscle Fibers, Slow-Twitch/pathology
- Muscle Fibers, Slow-Twitch/physiology
- Muscle, Skeletal/chemistry
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/physiology
- Muscular Atrophy/metabolism
- Muscular Atrophy/physiopathology
- Myosin Heavy Chains/analysis
- Myosin Heavy Chains/chemistry
- Myosin Heavy Chains/genetics
- Phenotype
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Space Flight
- Weightlessness
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Effect of spaceflight on skeletal muscle: mechanical properties and myosin isoform content of a slow muscle. J Appl Physiol (1985) 1994; 76:1764-73. [PMID: 8045858 DOI: 10.1152/jappl.1994.76.4.1764] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
This study examined changes in contractile, biochemical, and histochemical properties of slow antigravity skeletal muscle after a 6-day spaceflight mission. Twelve male Sprague-Dawley rats were randomly divided into two groups: flight and ground-based control. Approximately 3 h after the landing, in situ contractile measurements were made on the soleus muscles of the flight animals. The control animals were studied 24 h later. The contractile measurements included force-velocity relationship, force-frequency relationship, and fatigability. Biochemical measurements focused on the myosin heavy chain (MHC) and myosin light chain profiles. Adenosine-triphosphatase histochemistry was performed to identify cross-sectional area of slow and fast muscle fibers and to determine the percent fiber type distribution. The force-velocity relationships of the flight muscles were altered such that maximal isometric tension (Po) was decreased by 24% and maximal shortening velocity was increased by 14% (P < 0.05). The force-frequency relationship of the flight muscles was shifted to the right of the control muscles. At the end of the 2-min fatigue test, the flight muscles generated only 34% of Po, whereas the control muscles generated 64% of Po. The flight muscles exhibited de novo expression of the type IIx MHC isoform as well as a slight decrease in the slow type I and fast type IIa MHC isoforms. Histochemical analyses of flight muscles demonstrated a small increase in the percentage of fast type II fibers and a greater atrophy of the slow type I fibers. The results demonstrate that contractile properties of slow antigravity skeletal muscle are sensitive to the microgravity environment and that changes begin to occur within the 1st wk. These changes were at least, in part, associated with changes in the amount and type of contractile protein expressed.
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A population-wide profile of prescription drug use in Saskatchewan, 1989. CMAJ 1992; 146:2177-86. [PMID: 1351790 PMCID: PMC1492271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2023] Open
Abstract
OBJECTIVE To measure the prevalence of prescription drug use in Saskatchewan in 1989. DESIGN Retrospective study. PARTICIPANTS A total of 961,203 Saskatchewan residents (including those who died or were born during the study year) who were eligible for coverage under the Saskatchewan Prescription Drug Plan. The study population represented 94% of the province's total population; those excluded were mostly status Indians (for whom a federal plan is available). MAIN RESULTS At least one prescription was received by 66.0% of the study population in 1989. The mean number of prescriptions per patient was 8.2, and the mean cost of drug material per prescription was $13.95. Females received substantially more prescriptions than males; the difference was particularly notable for cardiovascular agents, antidepressants and benzodiazepines. In the senior population 80.8% received at least one prescription; the mean number of prescriptions per patient was 18.4. The most commonly dispensed drug for the entire study population was amoxicillin (290 prescriptions per 1000 people); triazolam was the most frequently dispensed central nervous system drug (74 prescriptions per 1000 people). Regional variation in overall drug use was remarkably small, although it increased at the drug-class level, especially for tranquillizers. The use of cardiovascular drugs was 27% to 32% higher (depending on how use was measured) per Regina resident than per Saskatoon resident. Benzodiazepines were commonly used on a long-term basis, despite recommendations to the contrary. CONCLUSIONS The results quantify the prevalence of prescription drug use, underscore the importance of careful management of drug therapy by physicians and pharmacists (especially for seniors), illustrate substantial variation in drug therapy strategies and raise questions about utilization of benzodiazepines and cardiovascular drugs.
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High phosphorus concentration in Trifolium balansae and Medicago polymorpha seed increases in herbage and seed yields in the field. ACTA ACUST UNITED AC 1989. [DOI: 10.1071/ea9890791] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Seed of Trifolium balansae and Medicago polymorpha, of the same size (mean ± s.d., T. balansae 0.8 ± 0.01 mglseed, M. polymorpha 3.6 ± 0.05 mg/seed) but with increasing phosphorus (P) concentration in the seed (T. balansae 0.34 to 0.63% P, M. polymorpha 0.40 to 0.64% P), were sown in field experiments as singlestrain, dense, ungrazed swards on 2 different soil types (a sand and a lateritic gravel sand) in south-western Australia. Different amounts of superphosphate were drilled with the seed (5-40 kg P/ha for the sand, and 15-100 kg P/ha for the lateritic gravel sand). Increasing P concentration in seed increased yields of dried herbage measured at each harvest, and also increased seed yields (measured for M. polymorpha only). Increasing P concentration in the seed increased the effectiveness of superphosphate drilled with the seed, so that less fertiliser was required to produce the same yield as P concentration in the seed increased.
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Increasing phosphorus concentration in lupin seed increases grain yield on phosphorus deficient soil. ACTA ACUST UNITED AC 1989. [DOI: 10.1071/ea9890797] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In a field experiment on a phosphorus (P) deficient soil in south-western Australia, lupin seed (Lupinus angustifolius cv. Danja) of the same size (157 mg/seed) but with 2 different phosphorus (P) concentrations in the seed (2.0 and 2.8 g P/kg) was sown with 4 levels of superphosphate (5, 20, 40 and 60 kg P/ha) drilled with the seed in May 1988 to examine the effect of seed P concentration on subsequent dry matter (DM) and grain yields. Increasing the amount of superphosphate applied from 5 to 60 kg P/ha almost doubled yields. In addition, lupins grown from seed containing the higher P concentration produced larger yields of dried whole tops in early August (69-day-old) for all levels of superphosphate drilled with the seed, the difference decreasing from about 45 to 10% as the level of superphosphate increased from 5 to 60 kg P/ha. By maturity (mid- November), however, plants grown from seed containing the higher P concentration in seed produced higher DM yields of tops and grain only when 5 and 20 kg P/ha superphosphate was drilled with the seed, the differences being about 40 and 20%, respectively.
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The Chief Scientist reports ... marketing health. HEALTH BULLETIN 1988; 46:296-303. [PMID: 3182269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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High phosphorus concentrations in seed of wheat and annual medic are related to higher rates of dry matter production of seedlings and plants. ACTA ACUST UNITED AC 1988. [DOI: 10.1071/ea9880765] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Seed of 2 cultivars of wheat (Triticum aestivum) and 1 burr medic (Medicago polymorpha) with increasing phosphorus (P) concentrations (wheat 1.4-3.7 g P/kg dry matter, medic 3.3-7.9 g P/kg dry matter) were collected from field experiments with variable levels of applied superphosphate (wheat 0- 577 kg P/ha, medic 0-364 kg P/ha) in south-western Australia. These seeds were used in further experiments to examine the effect of seed P concentration on the subsequent dry matter (DM) production of seedlings and plants in 3 glasshouse pot experiments and 1 field experiment. Seed of the same size (wheat, 35 mg/seed; medic, 3.6 mg/seed) but with increasing P concentration produced substantially higher DM yields in the absence or presence of freshly applied superphosphate P up to 28-35 days after sowing in the pot experiments and 67 days after sowing in the field experiment.
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The University of Southern California's Committee in Action. LABORATORY ANIMAL SCIENCE 1987; 37 Spec No:81-9. [PMID: 3626512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Comparative digestion, rumen fermentation and kinetics of forage diets by steers and wethers. J Anim Sci 1984; 59:237-45. [PMID: 6086564 DOI: 10.2527/jas1984.591237x] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Four rumen fistulated wether and beef steers were used to evaluate differences in dry matter digestibility (DMD) between cattle and sheep. They were fed either perennial ryegrass or switchgrass hay at an ad libitum or restricted level for four experimental periods. Significant ruminant species X forage and ruminant species X level of intake (P less than .05) interactions were observed for digestible dry matter. The steers digested the switchgrass 7 percentage units greater than the wethers while ryegrass was digested equally. Digestibility differences between the steers and wethers were 6 percentage units at the ad libitum level of intake and 1 unit at the restricted level of intake. Crude protein digestibility tended to be greater (P less than .10) for sheep with a 7 unit difference for switchgrass and a 3 unit difference for ryegrass. The mean ruminal solids retention time of the digesta was approximately (P less than .01) 50% greater (26.0 vs 17.4 h) in cattle, with no difference in ruminal liquid dilution rate (LD) between animal species. Total ruminal volatile fatty acid concentration differed (P less than .01) with level of intake; however, no influence due to intake on the molar proportion of acetate (P greater than .10) or propionate (P greater than .10) was evident in spite of a difference (P less than .01) in LD. Rumen pH (P less than .05) and osmolality (P less than .01) were affected by both level of intake and forage, with the ryegrass and high level of intake decreasing pH and increasing osmolality.(ABSTRACT TRUNCATED AT 250 WORDS)
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Abstract
Repeated blockade of the endorphin receptors eventually induces symptoms resembling an opiate abstinence syndrome, despite the complete absence of opiate narcotics. Rats were injected with 0.6 mg/kg naloxone or with injection vehicle alone twice a day for six days. They were observed twice a day for four subsequent days. Body shakes, head shakes, scratches and total symptoms were significantly elevated in the naloxone treated group over controls. Symptoms were completely reversed by a small dose of morphine but not by naloxone. In a second experiment, rats were injected for ten days with the same dosage of naloxone. The abstinence-like syndrome began after six days of naloxone and continued for several days after cessation of injections. Total symptoms, body shakes, scratches and aggression were significantly elevated over controls and were reversed by morphine but not by naloxone.
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The surgical management of elbow joint deformity associated with premature growth plate closure in dogs. J Small Anim Pract 1978; 19:639-45. [PMID: 713492 DOI: 10.1111/j.1748-5827.1978.tb05553.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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The reasons and cure for dehumanization in nursing homes. HOSPITAL & COMMUNITY PSYCHIATRY 1974; 25:173-4. [PMID: 4832743 DOI: 10.1176/ps.25.3.173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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