Association of Pericentrin with the γ Tubulin Ring Complex: a Dissertation

Pericentrin is a molecular scaffold protein. It anchors protein kinases, (PKB, (Purohit, personal communication), PKC, (Chen et al., 2004), PKA Diviani et al., 2000), the γ tubulin ring complex, (γ TuRC) (Zimmerman et al., 2004), and possibly dynein (Purohit et al., 1999) to the spindle pole. The γ TuRC is a ~ 2 MDa complex which binds the minus ends of microtubules and nucleates microtubules in vitro, (Zheng et al., 1995). Prior to this work, nothing was known about the association of the γTuRC with pericentrin. Herein I report the biochemical identification of a large protein complex in Xenopus extracts containing pericentrin, the γ TuRC, and other as yet unidentified proteins. Immunodepletion of γ tubulin results in co-depletion of pericentrin, indicating that virtually all the pericentrin in a Xenopus extract is associated with γ tubulin. However, pericentrin is not a member of the, γ TuRC, since isolated γ TuRCs do not contain pericentrin. The association of pericentrin with the γ TuRC is readily disrupted, resulting in two separable complexes, a small pericentrin containing complex of approximately 740 KDa and the the γ TuRC, 1.9 MDa in Xenopus. Co overexpression/ coimmunoprecipitation and yeast two hybrid studies demonstrate that pericentrin binds the γTuRC through interactions with both GCP2 and GCP3. When added to Xenopus mitotic extracts, the GCP2/3 binding domain uncoupled γ TuRCs from centrosomes, inhibited microtubule aster assembly and induced rapid disassembly of pre-assembled asters. All phenotypes were significantly reduced in a pericentrin mutant with diminished GCP2/3 binding, and were specific for mitotic centro somal asters as I observed little effect on interphase asters or on asters assembled by the Ran-mediated centrosome-independent pathway. Overexpression of the GCP2/3 binding domain of pericentrin in somatic cells perturbed mitotic astral microtubules and spindle bipolarity. Likewise pericentrin silencing by small interfering RNAs in somatic cells disrupted γ tubulin localization and spindle organization in mitosis but had no effect on γ tubulin localization or microtubule organization in interphase cells. Pericentrin silencing or overexpression induced G2/antephase arrest followed by apoptosis in many but not all cell types. I conclude that pericentrin anchoring of γ tubulin complexes at centrosomes in mitotic cells is required for proper spindle organization and that loss of this anchoring mechanism elicits a checkpoint response that prevents mitotic entry and triggers apoptotic cell death. Additionally, I provide functional and in vitro evidence to suggest that the larger pericentrin isoform (pericentrin B/ Kendrin) is not functionally homologous to pericentrin/pericentrin A in regard to it\u27s interaction with the γ TuRC

Evaluation of an Alternative School's Impact on the Graduation Rate Overall and for Students Receiving Free or Reduced Price Meals in One Local School System

Free and reduced meals (FARM) students in one Maryland school system are dropping out of school at a rate almost five times greater than non-FARM students. In order to address the overall and the FARM subgroup dropout rate an intervention program was implemented. The program invited students with the greatest risk of dropping out to attend. Small class sizes and faculty that focused on building relationships and meeting each individual student’s social and emotional needs are hallmarks of the intervention. The effectiveness of the program was established through three tests: 1. Finding the average overall dropout rate before the inception of the program compared to dropout rate after the implementation; 2. A logistic regression to determine the probability of a student graduating from high school based on data from a group of students who attended the intervention as compared to a demographically matched group of students who did not attend; 3. A logistic regression to determine the probability of a student graduating based on data from a group of students who attended the program as compared to a pooled group of students who where invited to attend, but did not. The results suggest the program is effective; however, the reader should be cautioned as the results are based on a small sample size. The county experienced a 5.35% decrease in the overall dropout rate and a 6.80% decrease in the FARM dropout rate after the implementation of the program. Matched students who attended the program were almost fifteen times more likely to graduate than their peers who did not attend the program, and matched FARM students were fourteen times more likely to graduate. Students who attended the program had an almost nine times greater chance of graduating, and FARM students had an eight times greater probability of graduating, than students who were invited to attend but did not. The results show a relationship between the implementation of the dropout intervention program and a decrease in the dropout rate for the county and for the FARM subgroup

Centrosome-intrinsic mechanisms modulate centrosome integrity during fever

The centrosome is critical for cell division, ciliogenesis, membrane trafficking, and immunological synapse function. The immunological synapse is part of the immune response, which is often accompanied by fever/heat stress (HS). Here we provide evidence that HS causes deconstruction of all centrosome substructures primarily through degradation by centrosome-associated proteasomes. This renders the centrosome nonfunctional. Heat-activated degradation is centrosome selective, as other nonmembranous organelles (midbody, kinetochore) and membrane-bounded organelles (mitochondria) remain largely intact. Heat-induced centrosome inactivation was rescued by targeting Hsp70 to the centrosome. In contrast, Hsp70 excluded from the centrosome via targeting to membranes failed to rescue, as did chaperone inactivation. This indicates that there is a balance between degradation and chaperone rescue at the centrosome after HS. This novel mechanism of centrosome regulation during fever contributes to immunological synapse formation. Heat-induced centrosome inactivation is a physiologically relevant event, as centrosomes in leukocytes of febrile patients are disrupted. Cell Biology under license from the author(s)

An Open-Access Review to Determine Best Evidence-Based Practice for COPD

Background: The manifestation of Chronic Obstructive Pulmonary Disease (COPD) can have an enormous impact on individuals’ areas of occupation, specifically activities of daily living. Occupational therapy (OT) practitioners have the ability to efficiently treat these clients using evidence-based interventions to achieve optimal functioning and quality of life. The purpose of this research study was to identify specific interventions supported by evidence for consumers with COPD using an open-access database for OT. Method: A thematic synthesis of 102 articles available on COPD via the open-access database OTseeker was used in this study. A constant comparison approach revealed seven descriptive themes for intervention including exercise, education, self-management, cognitive-behavioral therapy, complementary and alternative medicine therapy, breathing technique training, and nutrition. Results: For each theme, sub-themes were discussed and components of effective interventions were identified. Aspects of an evidence-based intervention program for individuals with COPD were outlined. Conclusion: Occupational therapists can use this evidence to thoroughly design well-rounded effective evidence-based intervention programs to enable individuals with COPD to live life to its fullest

Identifying verbal short-term memory and working memory impairments in individuals with latent aphasia

PURPOSE : This study was undertaken to explore whether measures of verbal short-term memory and working memory are sensitive to impairments in people with latent aphasia, who score within normal limits on typical aphasia test batteries. METHOD : Seven individuals with latent aphasia and 24 neurotypical control participants completed 40 tasks from the Temple Assessment of Language and Short-term Memory in Aphasia (TALSA) that assess various aspects of verbal short-term memory, working memory, and language processing. Subtests were identified that differentiated between the two groups of participants. RESULTS : Twenty-one TALSA tasks were identified on which the participants with latent aphasia had significantly different performance than the typical control participants. All of these subtests engaged verbal short-term memory, and some involved working memory as well. Furthermore, the TALSA detected individual differences in linguistic profiles among participants with latent aphasia. CONCLUSIONS : People with latent aphasia may be identified by tests that tap verbal short-term memory and working memory. In addition, the TALSA was found to be sensitive to the heterogeneity of this population. Further development of these measures will improve identification and treatment of this challenging population.The National Institute on Deafness and Other Communication Disordershttps://pubs.asha.org/journal/ajslphj2022Speech-Language Pathology and Audiolog

A Comparison of Administrative and Physiologic Predictive Models in Determining Risk Adjusted Mortality Rates in Critically Ill Patients

Hospitals are increasingly compared based on clinical outcomes adjusted for severity of illness. Multiple methods exist to adjust for differences between patients. The challenge for consumers of this information, both the public and healthcare providers, is interpreting differences in risk adjustment models particularly when models differ in their use of administrative and physiologic data. We set to examine how administrative and physiologic models compare to each when applied to critically ill patients.We prospectively abstracted variables for a physiologic and administrative model of mortality from two intensive care units in the United States. Predicted mortality was compared through the Pearsons Product coefficient and Bland-Altman analysis. A subgroup of patients admitted directly from the emergency department was analyzed to remove potential confounding changes in condition prior to ICU admission.We included 556 patients from two academic medical centers in this analysis. The administrative model and physiologic models predicted mortalities for the combined cohort were 15.3% (95% CI 13.7%, 16.8%) and 24.6% (95% CI 22.7%, 26.5%) (t-test p-value<0.001). The r(2) for these models was 0.297. The Bland-Atlman plot suggests that at low predicted mortality there was good agreement; however, as mortality increased the models diverged. Similar results were found when analyzing a subgroup of patients admitted directly from the emergency department. When comparing the two hospitals, there was a statistical difference when using the administrative model but not the physiologic model. Unexplained mortality, defined as those patients who died who had a predicted mortality less than 10%, was a rare event by either model.In conclusion, while it has been shown that administrative models provide estimates of mortality that are similar to physiologic models in non-critically ill patients with pneumonia, our results suggest this finding can not be applied globally to patients admitted to intensive care units. As patients and providers increasingly use publicly reported information in making health care decisions and referrals, it is critical that the provided information be understood. Our results suggest that severity of illness may influence the mortality index in administrative models. We suggest that when interpreting "report cards" or metrics, health care providers determine how the risk adjustment was made and compares to other risk adjustment models

Cost impact of procalcitonin-guided decision making on duration of antibiotic therapy for suspected early-onset sepsis in neonates

Abstract Backgrounds The large, international, randomized controlled NeoPInS trial showed that procalcitonin (PCT)-guided decision making was superior to standard care in reducing the duration of antibiotic therapy and hospitalization in neonates suspected of early-onset sepsis (EOS), without increased adverse events. This study aimed to perform a cost-minimization study of the NeoPInS trial, comparing health care costs of standard care and PCT-guided decision making based on the NeoPInS algorithm, and to analyze subgroups based on country, risk category and gestational age. Methods Data from the NeoPInS trial in neonates born after 34 weeks of gestational age with suspected EOS in the first 72 h of life requiring antibiotic therapy were used. We performed a cost-minimization study of health care costs, comparing standard care to PCT-guided decision making. Results In total, 1489 neonates were included in the study, of which 754 were treated according to PCT-guided decision making and 735 received standard care. Mean health care costs of PCT-guided decision making were not significantly different from costs of standard care (€3649 vs. €3616). Considering subgroups, we found a significant reduction in health care costs of PCT-guided decision making for risk category ‘infection unlikely’ and for gestational age ≥ 37 weeks in the Netherlands, Switzerland and the Czech Republic, and for gestational age < 37 weeks in the Czech Republic. Conclusions Health care costs of PCT-guided decision making of term and late-preterm neonates with suspected EOS are not significantly different from costs of standard care. Significant cost reduction was found for risk category ‘infection unlikely,’ and is affected by both the price of PCT-testing and (prolonged) hospitalization due to SAEs

Machine learning used to compare the diagnostic accuracy of risk factors, clinical signs and biomarkers and to develop a new prediction model for neonatal early-onset sepsis

Background: Current strategies for risk stratification and prediction of neonatal early-onset sepsis (EOS) are inefficient and lack diagnostic performance. The aim of this study was to use machine learning to analyze the diagnostic accuracy of risk factors (RFs), clinical signs and biomarkers and to develop a prediction model for culture-proven EOS. We hypothesized that the contribution to diagnostic accuracy of biomarkers is higher than of RFs or clinical signs. Study Design: Secondary analysis of the prospective international multicenter NeoPInS study. Neonates born after completed 34 weeks of gestation with antibiotic therapy due to suspected EOS within the first 72 hours of life participated. Primary outcome was defined as predictive performance for culture-proven EOS with variables known at the start of antibiotic therapy. Machine learning was used in form of a random forest classifier. Results: One thousand six hundred eighty-five neonates treated for suspected infection were analyzed. Biomarkers were superior to clinical signs and RFs for prediction of culture-proven EOS. C-reactive protein and white blood cells were most important for the prediction of the culture result. Our full model achieved an area-under-the-receiver-operating-characteristic-curve of 83.41% (±8.8%) and an area-under-the-precision-recall-curve of 28.42% (±11.5%). The predictive performance of the model with RFs alone was comparable with random. Conclusions: Biomarkers have to be considered in algorithms for the management of neonates suspected of EOS. A 2-step approach with a screening tool for all neonates in combination with our model in the preselected population with an increased risk for EOS may have the potential to reduce the start of unnecessary antibiotics

Effectiveness of adjuvant occupational therapy in employees with depression: design of a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Major depressive disorder is among the medical conditions with the highest negative impact on work outcome. However, little is known regarding evidence-based interventions targeting the improvement of work outcomes in depressed employees. In this paper, the design of a randomized controlled trial is presented in order to evaluate the effectiveness of adjuvant occupational therapy in employees with depression. This occupational intervention is based on an earlier intervention, which was designed and proven effective by our research group, and is the only intervention to date that specifically targets work outcome in depressed employees.</p> <p>Methods/Design</p> <p>In a two-arm randomized controlled trial, a total of 117 participants are randomized to either 'care as usual' or <it>' </it>care as usual' with the addition of occupational therapy. Patients included in the study are employees who are absent from work due to depression for at least 25% of their contract hours, and who have a possibility of returning to their own or a new job. The occupational intervention consists of six individual sessions, eight group sessions and a work-place visit over a 16-week period. By increasing exposure to the working environment, and by stimulating communication between employer and employee, the occupational intervention aims to enhance self-efficacy and the acquisition of more adaptive coping strategies. Assessments take place at baseline, and at 6, 12, and 18-month follow-ups. Primary outcome measure is work participation (hours of absenteeism and time until work resumption). Secondary outcome measures are work functioning, symptomatology, health-related quality of life, and neurocognitive functioning. In addition, cost-effectiveness is evaluated from a societal perspective. Finally, mechanisms of change (intermediate outcomes) and potential patient-treatment matching variables are investigated.</p> <p>Discussion</p> <p>This study hopes to provide valuable knowledge regarding an intervention to treat depression, one of the most common and debilitating diseases of our time. If our intervention is proven (cost-) effective, the personal, economic, and health benefits for both patients and employers are far-reaching.</p> <p>Trial registration number</p> <p>NTR2057</p

Protocol for Fit Bodies, Fine Minds: a randomized controlled trial on the affect of exercise and cognitive training on cognitive functioning in older adults

Background. Declines in cognitive functioning are a normal part of aging that can affect daily functioning and quality of life. This study will examine the impact of an exercise training program, and a combined exercise and cognitive training program, on the cognitive and physical functioning of older adults. Methods/Design. Fit Bodies, Fine Minds is a randomized, controlled trial. Community-dwelling adults, aged between 65 and 75 years, are randomly allocated to one of three groups for 16 weeks. The exercise-only group do three 60-minute exercise sessions per week. The exercise and cognitive training group do two 60-minute exercise sessions and one 60-minute cognitive training session per week. A no-training control group is contacted every 4 weeks. Measures of cognitive functioning, physical fitness and psychological well-being are taken at baseline (0 weeks), post-test (16 weeks) and 6-month follop (40 weeks). Qualitative responses to the program are taken at post-test. Discussion. With an increasingly aged population, interventions to improve the functioning and quality of life of older adults are particularly important. Exercise training, either alone or in combination with cognitive training, may be an effective means of optimizing cognitive functioning in older adults. This study will add to the growing evidence base on the effectiveness of these interventions. Trial Registration. Australian Clinical Trials Register: ACTRN012607000151437