The Patient Symptom Experience After Tisagenlecleucel and Lisocabtagene Maraleucel CAR T-Cell Therapy for Lymphoma

OBJECTIVES

Chimeric Antigen Receptor (CAR) T-cell treatment is associated with several unique toxicities, and the short-term symptom trajectory in the immediately after therapy is well-documented. However, little is known about patients' long-term symptom experience. The study aimed to elicit the symptom experience of adult patients in remission after CAR T-cell therapy for B cell lymphoma.

DATA SOURCES

A qualitative descriptive design with thematic analysis was utilized. Recruitment occurred at a tertiary academic medical center using the following inclusion criteria: adult recipient of CAR T-cell therapy for B-cell lymphoma between 3 and 12 months prior to enrollment, and currently in remission. Semi-structured interviews were conducted, transcripts were inductively coded, and team members met weekly to ensure rigor. The final sample included 10 patients: Seven received tisagenlecleucel and three received lisocabtagene marleucel and were a median of 169 days post-infusion and 65 years of age.

CONCLUSIONS

Participants continued to report symptoms, including fatigue, neuropathy, low endurance, insomnia, memory problems, and pain. Most symptoms improved over time. Some symptoms interfered with social activities, work, driving, and physical activity, though participants reported that most symptoms existed prior to CAR T-cell therapy, and overall, found CAR T-cell therapy acceptable.

IMPLICATIONS FOR NURSING PRACTICE

Patients in remission after CAR T-cell therapy often continue to experience symptoms. Nurses should continue to assess this growing patient population and determine if patients require additional symptom management or support. Further research is needed to understand long-term symptom trajectory and associations with prior lines of therapy and CAR T-cell therapy.

An Integrative Review of Measures of Spirituality in Experimental Studies of Psilocybin in Serious Illness Populations

Background: Psilocybin-assisted therapies (PAT) are reemerging as a treatment for complex distress often prompting mystical experiences, enhanced meaning, and spiritual wellbeing. We sought to investigate how measures of spirituality are employed in experimental studies of PAT conducted with seriously ill adults. Methods: We included experimental studies of psilocybin conducted with seriously ill adults, which employed measures that contained spirituality and mysticism concepts within their domains or subdomains. Included studies were peer-reviewed and published in English language (up to December 2021). Results: Seven articles met our inclusion criteria. A total of 12 unique instruments were identified. The most frequently used instruments were the Mystical Experience Questionnaire (MEQ30), the Functional Assessment of Chronic Illness Therapy-Spirituality (FACIT-Sp-12), and the Demoralization Scale (DS-I/II) (used in four studies each), followed by the Persisting Effects Questionnaire (PEQ) (used in three studies). Overall, studies did not consistently define and contextualize spirituality domains and subdomains studied. Conclusions: Despite well-recognized significance of spirituality in PAT, there was considerable heterogeneity in number and types of spirituality measures employed across studies. There also seemed a lack of attention to defining and operationalizing spirituality and its domains and subdomains. This is notable as spirituality and overlapping concepts (eg mystical experiences) contributes substantially to this body of research and patients' therapeutic outcomes. Towards developing more rigorous science of spirituality in PAT research, there is a critical need to evaluate and refine measures of spirituality to enhance their utility and replicability, limit participant burden, and better contextualize spirituality-related findings and outcomes.

Currently recommended skin scores correlate highly in the assessment of patients with Juvenile Dermatomyositis (JDM)

BACKGROUND

Juvenile Dermatomyositis (JDM) is a rare, chronic, and life-threatening childhood autoimmune disease. Currently, there are recommended, reliable and validated measurement tools for assessment of skin disease activity in JDM including the Disease Activity Score (skinDAS), Cutaneous Assessment Tool (CAT), and the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI). The Physician's global assessment skin visual analog scale (Skin VAS) is also widely used for skin activity in JDM. For the purpose of comparative international studies, we wanted to compare these tools to the Physician's skin VAS (as a standard) to identify which performs better.

OBJECTIVES

We sought to compare the correlations of these scoring tools, and separately assess the responsiveness each tool demonstrates following patient treatment, in order to see if one tool may be preferred. This was determined by assessing how well these tools correlate with each other, and the Physician's skin VAS over time, as well as the responsiveness of each tool after patient treatment.

METHODS

Skin scores were recorded at a baseline (first visit after June 1^st, 2018) and all follow-up office visits at the Juvenile Dermatomyositis Clinic. Following baseline visits, patients were followed up as clinically indicated. A subset of newly diagnosed patients (inception cohort) was identified. Correlations were assessed at the baseline visit and over time for the whole cohort. The correlations over time were derived using Generalized Estimating Equations (GEEs). Standardized response means with 95% confidence intervals were calculated to test score responsiveness for the nested inception cohort.

RESULTS

The skinDAS, CAT and CDASI all correlated highly with each other and with the Physician's skin VAS. The three scoring tools accurately reflected Physician's skin VAS scores over time. In addition, all tools showed moderate to high responsiveness following treatment.

CONCLUSION

All studied skin score tools performed well in our study and appear to be useful. Since no tool far outperforms the others, arbitrary consensus will be needed to select a single standard measurement tool for the purposes of efficiency and global comparability.

A roadmap: Social distancing physical activity data collection to protect those with intellectual disabilities

The novel coronavirus may impact exercise habits of those with intellectual disabilities. Due to the mandated discontinuation of face-to-face research, investigators must adapt projects to protect all involved while collecting objective physical activity metrics. This brief report outlines a modification process of research methods to adhere to social distancing mandates present during COVID-19. Actions taken included electronic consent and assent forms, an electronic survey, and mailing an accelerometer with included instructions. The amended research methods were implemented without risk for virus transmission or undue burden on the research team, participant, or caregiver. Recruitment was likely impacted by the coronavirus-mediated quarantine, plausibly resulting in bias. Objective physical activity data collection can be sufficiently modified to protect those with intellectual disabilities and investigators. Future research designs may require greater participant incentives and the creation of in-home participation.

Optimizing trilateration estimates for tracking fine‐scale movement of wildlife using automated radio telemetry networks

A major advancement in the use of radio telemetry has been the development of automated radio tracking systems (ARTS), which allow animal movements to be tracked continuously. A new ARTS approach is the use of a network of simple radio receivers (nodes) that collect radio signal strength (RSS) values from animal‐borne radio transmitters. However, the use of RSS‐based localization methods in wildlife tracking research is new, and analytical approaches critical for determining high‐quality location data have lagged behind technological developments. We present an analytical approach to optimize RSS‐based localization estimates for a node network designed to track fine‐scale animal movements in a localized area. Specifically, we test the application of analytical filters (signal strength, distance among nodes) to data from real and simulated node networks that differ in the density and configuration of nodes. We evaluate how different filters and network configurations (density and regularity of node spacing) may influence the accuracy of RSS‐based localization estimates. Overall, the use of signal strength and distance‐based filters resulted in a 3‐ to 9‐fold increase in median accuracy of location estimates over unfiltered estimates, with the most stringent filters providing location estimates with a median accuracy ranging from 28 to 73 m depending on the configuration and spacing of the node network. We found that distance filters performed significantly better than RSS filters for networks with evenly spaced nodes, but the advantage diminished when nodes were less uniformly spaced within a network. Our results not only provide analytical approaches to greatly increase the accuracy of RSS‐based localization estimates, as well as the computer code to do so, but also provide guidance on how to best configure node networks to maximize the accuracy and capabilities of such systems for wildlife tracking studies.

Effect of somatic maturity on the aerobic and anaerobic adaptations to sprint interval training

The purpose of this study was to assess the maturity-related differences in the aerobic and anaerobic adaptations to sprint interval training (SIT) among youth male athletes. Twenty-seven youth male athletes were assessed for years from peak height velocity (PHV) and classified into prepubescent (PRE, n = 7, years from PHV = -2.21 ± 0.47 years), peripubescent (PERI, n = 10, years from PHV = 0.25 ± 0.88 years), and postpubescent (POST, n = 10, years from PHV = 2.81 ± 0.50 years) groups based on their years from estimated peak height velocity. Participants completed a ramp exercise protocol on a cycle ergometer to determine maximal aerobic power, maximal oxygen consumption (VO2peak ), and fatigue thresholds. Following baseline, all participants completed a 4-week SIT program that consisted of eight total training sessions. During each session, participants completed repeated 20-s sprints on a cycle ergometer against a resistance of 7.5% of body mass. The number of sprints per sessions increased from four in session 1 to seven in session 7, with four sprints in session 8. Peak and mean power from sessions 1 and 8 were recorded. All participants completed a post-testing ramp exercise protocol that mirrored baseline. Maximal aerobic power increased (p < .001) across all groups from baseline (212.61 ± 57.45 W) to post-testing (223.24 ± 58.90 W); however, VO2peak only increased in POST (3.31 ± 0.43 to 3.54 ± 0.43 L min-1 , p = .003). Similarly, GET, VT, and RCP increased in POST, with no changes in PRE or PERI. In terms of anaerobic performance, PERI and POST had significant increases in peak and mean power. POST improved aerobic and anaerobic performance following SIT, while PERI only experienced improvements in anaerobic performance. Conversely, PRE had no changes in aerobic or anaerobic performance. The adaptations to SIT appear to be influenced by the somatic maturity status.

Adolescent Weight and Health Behaviors and Their Associations With Individual, Social, and Parental Factors

BACKGROUND

To examine the associations and differences between gender and weight classification for physical activity (PA) and individual, social, and parental factors.

METHODS

Data from wave 2 of the "Growing up in Ireland" national study were used, resulting in a sample of 7525 13-year-old adolescents. Information on factors affecting adolescents' social, emotional, cognitive, and physical development was collected.

RESULTS

Overweight (OW) adolescents were more likely to exercise and restrict food for weight loss and less likely to perform moderate to vigorous PA than normal weight adolescents. Parent body mass index was associated with adolescent body mass index for OW and normal weight adolescents, with the strongest association seen with OW females. Parents of OW adolescents considered themselves to be more OW and less physically active than parents of normal weight adolescents. Furthermore, for all groups, a greater amount of moderate to vigorous PA was associated with less television viewing, greater PA of parents, and a greater number of friends.

CONCLUSION

Parental health behaviors play a significant role in adolescents' bodyweight, representing the necessity for more constructive health behaviors and PA among parents. Future interventions may be strengthened by focusing specifically on gender and body mass index, while taking into consideration the importance of parental behaviors on adolescents.

A systematic evaluation of advance care planning patient educational resources

BACKGROUND

Advance care planning (ACP) conversations help individuals exercise autonomy and make informed decisions about their care. There are many ACP resources available to support the process of advance care planning, yet available resources not universally accepted and under-utilized in clinical practice.

OBJECTIVE

This study aims to systematically evaluate commonly available general ACP patient educational resources using a comprehensive approach to assess elements ranging from resource inclusion to health literacy.

DESIGN

Systematic evaluation of general ACP educational resources METHODS: ACP educational resources were systematically identified and evaluated for: Patient Education Materials Assessment Tool (PEMAT) score, Flesch-Kincaid reading ease and grade level, cost, languages available, and categories of content including Advance directive/Healthcare proxy, Physician Order for Life-Sustaining Treatment (POLST), Living will, values, preferences, and goals.

RESULTS

Educational resources (n = 20) were identified. These resources were classified as information resources, workbooks, interactive websites, or and activities/conversation guides. The average PEMAT understandability score was 86 (range 58-100) and the average actionability was 90 (range 40-100). Two resources met Flesch-Kincaid reading ease and grade level. Eight were available in English only, nine in two languages, and three in more than two languages. Three explicitly discussed completion of POLST forms. The majority of the resources adequately addressed the content of advanced directives and health care proxy, values, goals, and preferences for future care. The level of time commitment required to use each resource also varied considerably.

CONCLUSION

We present a comprehensive evaluation of resources to support ACP. Using the Transtheoretical Model, we provide a guide for the use of these educational resources based on patient readiness. This review allows clinicians to identify aspects of each resource that may be helpful in preparing older adults for future healthcare decsions. Our analysis has identified the need to continue to refine these educational resources so that they can reach a broad population with varying needs. Advance care planning (ACP) conversations help individuals exercise autonomy and make informed decisions about their care. There are many ACP educational resources available to support the process of advance care planning, yet available resources are not universally accepted and under-utilized in clinical practice. We present a comprehensive evaluation of 20 educational resources to support ACP. Educational resources were identified and evaluated for: Patient Education Materials Assessment Tool (PEMAT) score, Flesch-Kincaid reading ease and grade level, cost, languages available, and categories of content. Using the Transtheoretical Model, we provide a guide for the use of these educational resources based on patient readiness. This review allows clinicians to identify aspects of each resource that may be helpful in preparing older adults for future healthcare decisions. Our analysis has identified the need to continue to refine these educational resources so that they can reach a broad population with varying needs.

Comparison of sustained-release and rapid-release β-alanine formulations on changes in skeletal muscle carnosine and histidine content and isometric performance following a muscle-damaging protocol

β-alanine supplementation increases muscle carnosine content and improves anaerobic exercise performance by enhancing intracellular buffering capacity. β-alanine ingestion in its traditional rapid-release formulation (RR) is associated with the symptoms of paresthesia. A sustained-release formulation (SR) of β-alanine has been shown to circumvent paresthesia and extend the period of supply to muscle for carnosine synthesis. The purpose of this investigation was to compare 28 days of SR and RR formulations of β-alanine (6 g day^-1) on changes in carnosine content of the vastus lateralis and muscle fatigue. Thirty-nine recreationally active men and women were assigned to one of the three groups: SR, RR, or placebo (PLA). Participants supplementing with SR and RR formulations increased muscle carnosine content by 50.1% (3.87 mmol kg^-1ww) and 37.9% (2.62 mmol kg^-1ww), respectively. The change in muscle carnosine content in participants consuming SR was significantly different (p = 0.010) from those consuming PLA, but no significant difference was noted between RR and PLA (p = 0.077). Although participants ingesting SR experienced a 16.4% greater increase in muscle carnosine than RR, fatigue during maximal voluntary isometric contractions was significantly attenuated in both SR and RR compared to PLA (p = 0.002 and 0.024, respectively). Symptoms of paresthesia were significantly more frequent in RR compared to SR, the latter of which did not differ from PLA. Results of this study demonstrated that only participants consuming the SR formulation experienced a significant increase in muscle carnosine. Differences in the muscle carnosine response between these formulations may have practical significance for athletic populations in which small changes may have important implications on performance.

Monocyte Recruitment after High-Intensity and High-Volume Resistance Exercise

The innate immune response is generally considered to have an important role in tissue remodeling after resistance exercise.

PURPOSE

The purpose of this study was to compare changes in markers of monocyte recruitment after an acute bout of high-intensity (HVY) versus high-volume (VOL) lower-body resistance exercise.

METHODS

Ten resistance-trained men (24.7 ± 3.4 yr, 90.1 ± 11.3 kg, 176.0 ± 4.9 cm) performed each protocol in a randomized, counterbalanced order. Blood samples were collected at baseline, immediately (IP), 30 min (30P), 1 h (1H), 2 h (2H), and 5 h (5H) postexercise. Plasma concentrations of monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor alpha (TNF-α), myoglobin, and cortisol were measured via assay. Tumor necrosis factor receptor 1 (TNFr1), macrophage-1 antigen (cluster of differentiation 11b [CD11b]), and C-C chemokine receptor 2 (CCR2) expression levels were measured using flow cytometry. TNFr1 and CD11b were assessed on CD14CD16 monocytes, whereas CCR2 was assessed on CD14 monocytes.

RESULTS

Plasma myoglobin concentrations were significantly greater after HVY compared with VOL (P < 0.001). Changes in plasma TNF-α, MCP-1, and expression levels of CCR2 and CD11b were similar between HVY and VOL. When collapsed across groups, TNF-α was significantly increased at IP, 30P, 1H, and 2H (P values < 0.05), whereas MCP-1 was significantly elevated at all postexercise time points (P values < 0.05). CCR2 expression on CD14 monocytes was significantly lower at IP, 1H, 2H, and 5H (P values < 0.05). CD11b expression on CD14 CD16 was significantly greater at IP (P < 0.014) and 1H (P = 0.009). TNFr1 expression did not differ from baseline at any time point. Plasma cortisol concentrations did not seem to be related to receptor expression.

CONCLUSIONS

Results indicate that both HVY and VOL protocols stimulate a robust proinflammatory response. However, no differences were noted between resistance exercise training paradigms.

Post-resistance exercise ingestion of milk protein attenuates plasma TNFα and TNFr1 expression on monocyte subpopulations

Attenuating TNFα/TNFr1 signaling in monocytes has been proposed as a means of mitigating inflammation. The purpose of this study was to examine the effects of a milk protein supplement on TNFα and monocyte TNFr1 expression. Ten resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) ingested supplement (SUPP) or placebo (PL) immediately post-exercise in a randomized, cross-over design. Blood samples were obtained at baseline (BL), immediately (IP), 30-min (30P), 1-h (1H), 2-h (2H), and 5-h (5H) post-exercise to assess plasma concentrations of myoglobin; tumor necrosis factor-alpha (TNFα); and expression of tumor necrosis factor receptor 1 (TNFr1) on classical, intermediate, and non-classical monocytes. Magnitude-based inferences were used to provide inferences on the true effects of SUPP compared to PL. Plasma TNFα concentrations were "likely attenuated" (91.6% likelihood effect) from BL to 30P in the SUPP group compared with PL (d = 0.87; mean effect: 2.3 ± 2.4 pg mL^-1). TNFr1 expressions on classical (75.9% likelihood effect) and intermediate (93.0% likelihood effect) monocytes were "likely attenuated" from BL to 2H in the SUPP group compared with PL (d = 0.67; mean effect: 510 ± 670 RFU, and d = 1.05; mean effect: 2500 ± 2300 RFU, respectively). TNFr1 expression on non-classical monocytes was "likely attenuated" (77.6% likelihood effect) from BL to 1H in the SUPP group compared with PL (d = 0.69; mean effect: 330 ± 430 RFU). Ingestion of a milk protein supplement immediately post-exercise appears to attenuate both plasma TNFα concentrations and TNFr1 expression on monocyte subpopulations in resistance-trained men.

Changes in Plasma Aldosterone and Electrolytes Following High-Volume and High-Intensity Resistance Exercise Protocols in Trained Men

Boone, CH, Hoffman, JR, Gonzalez, AM, Jajtner, AR, Townsend, JR, Baker, KM, Fukuda, DH, and Stout, JR. Changes in plasma aldosterone and electrolytes following high-volume and high-intensity resistance exercise protocols in trained men. J Strength Cond Res 30(7): 1917-1923, 2016-Program variables such as training intensity, volume, and rest interval length are known to elicit distinct hormonal, metabolic, and physical responses. However, little is known regarding resistance exercise (RE) program design and the fluid regulatory response. This investigation aimed to compare the plasma aldosterone (ALD), electrolyte, plasma volume (PV), and osmolality (Posm) responses following high-volume (HV; 4-6 × 10-12 reps, 70% 1 repetition maximum [1RM], 60-s rest) and high-intensity (HI; 6 × 3-5 reps, 90% 1RM, 180-second rest) RE protocols. Ten experienced, resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) performed each protocol in a random, counterbalanced order. Blood samples were obtained at baseline (BL), immediately (IP), 30 minutes (30P), and 1 hour (1H) postexercise. Significant trial × time interactions (p < 0.01) were observed in Posm, sodium (Na), and potassium (K), whereas a trend (p = 0.06) was observed for ALD. The PV shift from BL-30P was greater than BL-IP and BL-1H (p ≤ 0.05), but no significant between-trial differences were noted. Comparisons between RE protocols revealed significantly greater (p ≤ 0.05) elevations during HV vs. HI in Posm at IP, 30P, and 1H; and Na at IP and 30P. During HV, significant reductions (p ≤ 0.05) were noted in K at IP compared with HI. Area under the curve analysis indicates a trend (p = 0.07) toward a higher ALD response following HV compared with HI. Results of this study indicate that high-volume, moderate-intensity resistance exercise seems to augment the fluid regulatory response to a greater extent than low-volume, high-intensity training.

Resistance exercise increases intramuscular NF-κb signaling in untrained males

PURPOSE

The NF-κB signaling pathway regulates multiple cellular processes following exercise stress. This study aims to examine the effects of an acute lower-body resistance exercise protocol and subsequent recovery on intramuscular NF-κB signaling.

METHODS

Twenty-eight untrained males were assigned to either a control (CON; n = 11) or exercise group (EX; n = 17) and completed a lower-body resistance exercise protocol consisting of the back squat, leg press, and leg extension exercises. Skeletal muscle microbiopsies were obtained from the vastus lateralis pre-exercise (PRE), 1-hour (1H), 5-hours (5H), and 48-hours (48H) post-resistance exercise. Multiplex signaling assay kits (EMD Millipore, Billerica, MA, USA) were used to quantify the total protein (TNFR1, c-Myc) or phosphorylation status of proteins belonging to the NF-κB signaling pathway (IKKa/b, IkBα, NF-κB) using multiplex protein assay. Repeated measures ANOVA analysis was used to determine the effects of the exercise bout on intramuscular signaling at each time point. Additionally, change scores were analyzed by magnitude based inferences to determine a mechanistic interpretation.

RESULTS

Repeated measures ANOVA indicated a trend for a two-way interaction between the EX and CON Group (p = 0.064) for c-Myc post resistance exercise. Magnitude based inference analysis suggest a "Very Likely" increase in total c-Myc from PRE-5H and a "Likely" increase in IkBα phosphorylation from PRE-5H post-resistance exercise.

CONCLUSION

Results indicated that c-Myc transcription factor is elevated following acute intense resistance exercise in untrained males. Future studies should examine the role that post-resistance exercise NF-κβ signaling plays in c-Myc induction, ribosome biogenesis and skeletal muscle regeneration.

The effect of an acute ingestion of Turkish coffee on reaction time and time trial performance

BACKGROUND

The purpose of this study was to examine the ergogenic benefits of Turkish coffee consumed an hour before exercise. In addition, metabolic, cardiovascular, and subjective measures of energy, focus and alertness were examined in healthy, recreationally active adults who were regular caffeine consumers (>200 mg per day).

METHODS

Twenty males (n = 10) and females (n = 10), age 24.1 ± 2.9 y; height 1.70 ± 0.09 m; body mass 73.0 ± 13.0 kg (mean ± SD), ingested both Turkish coffee [3 mg · kg(-1) BW of caffeine, (TC)], and decaffeinated Turkish coffee (DC) in a double-blind, randomized, cross-over design. Performance measures included a 5 km time trial, upper and lower body reaction to visual stimuli, and multiple object tracking. Plasma caffeine concentrations, blood pressure (BP), heart rate and subjective measures of energy, focus and alertness were assessed at baseline (BL), 30-min following coffee ingestion (30+), prior to endurance exercise (PRE) and immediately-post 5 km (IP). Metabolic measures [VO2, V E , and respiratory exchange rate (RER)] were measured during the 5 km.

RESULTS

Plasma caffeine concentrations were significantly greater during TC (p < 0.001) at 30+, PRE, and IP compared to DC. Significantly higher energy levels were reported at 30+ and PRE for TC compared to DC. Upper body reaction performance (p = 0.023) and RER (p = 0.019) were significantly higher for TC (85.1 ± 11.6 "hits," and 0.98 ± 0.05 respectively) compared to DC (81.2 ± 13.7 "hits," and 0.96 ± 0.05, respectively). Although no significant differences (p = 0.192) were observed in 5 km run time, 12 of the 20 subjects ran faster (p = 0.012) during TC (1662 ± 252 s) compared to DC (1743 ± 296 s). Systolic BP was significantly elevated during TC in comparison to DC. No other differences (p > 0.05) were noted in any of the other performance or metabolic measures.

CONCLUSIONS

Acute ingestion of TC resulted in a significant elevation in plasma caffeine concentrations within 30-min of consumption. TC ingestion resulted in significant performance benefits in reaction time and an increase in subjective feelings of energy in habitual caffeine users. No significant differences were noted in time for the 5 km between trials, however 60 % of the participants performed the 5 km faster during the TC trial and were deemed responders. When comparing TC to DC in responders only, significantly faster times were noted when consuming TC compared to DC. No significant benefits were noted in measures of cognitive function.

Protein supplementation does not alter intramuscular anabolic signaling or endocrine response after resistance exercise in trained men

The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway appears to be the primary regulator of muscle protein synthesis. A variety of stimuli including resistance exercise, amino acids, and hormonal signals activate mTORC1 signaling. The purpose of this study was to investigate the effect of a protein supplement on mTORC1 signaling following a resistance exercise protocol designed to promote elevations in circulating hormone concentrations. We hypothesized that the protein supplement would augment the intramuscular anabolic signaling response. Ten resistance-trained men (age, 24.7 ± 3.4 years; weight, 90.1 ± 11.3 kg; height, 176.0 ± 4.9 cm) received either a placebo or a supplement containing 20 g protein, 6 g carbohydrates, and 1 g fat after high-volume, short-rest lower-body resistance exercise. Blood samples were obtained at baseline, immediately, 30 minutes, 1 hour, 2 hours, and 5 hours after exercise. Fine-needle muscle biopsies were completed at baseline, 1 hour, and 5 hours after exercise. Myoglobin, lactate dehydrogenase, and lactate concentrations were significantly elevated after resistance exercise (P < .0001); however, no differences were observed between trials. Resistance exercise also elicited a significant insulin, growth hormone, and cortisol response (P < .01); however, no differences were observed between trials for insulin-like growth factor-1, insulin, testosterone, growth hormone, or cortisol. Intramuscular anabolic signaling analysis revealed significant elevations in RPS6 phosphorylation after resistance exercise (P = .001); however, no differences were observed between trials for signaling proteins including Akt, mTOR, p70S6k, and RPS6. The endocrine response and phosphorylation status of signaling proteins within the mTORC1 pathway did not appear to be altered by ingestion of supplement after resistance exercise in resistance-trained men.

Intramuscular anabolic signaling and endocrine response following high volume and high intensity resistance exercise protocols in trained men

Resistance exercise paradigms are often divided into high volume (HV) or high intensity (HI) protocols, however, it is unknown whether these protocols differentially stimulate mTORC1 signaling. The purpose of this study was to examine mTORC1 signaling in conjunction with circulating hormone concentrations following a typical HV and HI lower-body resistance exercise protocol. Ten resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm) performed each resistance exercise protocol in a random, counterbalanced order. Blood samples were obtained at baseline (BL), immediately (IP), 30 min (30P), 1 h (1H), 2 h (2H), and 5 h (5H) postexercise. Fine needle muscle biopsies were completed at BL, 1H, and 5H. Electromyography of the vastus lateralis was also recorded during each protocol. HV and HI produced a similar magnitude of muscle activation across sets. Myoglobin and lactate dehydrogenase concentrations were significantly greater following HI compared to HV (P = 0.01–0.02), whereas the lactate response was significantly higher following HV compared to HI (P = 0.003). The growth hormone, cortisol, and insulin responses were significantly greater following HV compared to HI (P = 0.0001–0.04). No significant differences between protocols were observed for the IGF-1 or testosterone response. Intramuscular anabolic signaling analysis revealed a significantly greater (P = 0.03) phosphorylation of IGF-1 receptor at 1H following HV compared to HI. Phosphorylation status of all other signaling proteins including mTOR, p70S6k, and RPS6 were not significantly different between trials. Despite significant differences in markers of muscle damage and the endocrine response following HV and HI, both protocols appeared to elicit similar mTORC1 activation in resistance-trained men.

Evidence for a role of an intracardiac renin-angiotensin system in normal and failing hearts

Although substantial evidence of a cardiac RAS has been obtained in the past decade, a number of important questions remain unanswered. These include identification and localization of the cell types responsible for production of the system's components as well as the regulation of synthesis, storage, and secretion pathways for each component. Future studies, which will utilize tools of molecular biology that have become recently available (for example, transgenic animal models), renin inhibitors, angiotensin receptor antagonists, and bradykinin antagonists, will help to elucidate specific roles of the cardiac RAS in normal and failing hearts.

Nutritional value of soybean meal produced from conventional, high-protein, or low-oligosaccharide varieties of soybeans and fed to broiler chicks

Three experiments were conducted to determine the feeding value to broiler chicks of soybean meal (SBM) produced from high-protein (SBM-HP), low-oligosaccharide (SBM-LO), or conventional (SBM-CV) varieties of soybeans. The 3 SBM contained 54.9, 53.6, and 47.5% CP, respectively. The standardized digestibility (SDD) of amino acids (AA) in the 3 ingredients was measured using a precision-fed rooster assay with cecectomized Single Comb White Leghorn roosters. Results indicated that the SDD of AA was not different among the 3 sources of SBM, with the exception that the SDD of Lys in SBM-HP tended to be greater (P = 0.07) than that in SBM-CV. In the second experiment, a precision-fed rooster assay was used to measure the concentration of TME(n) in each source of SBM. Results indicated that the TME(n) in SBM-HP was greater (P < 0.001) than those in SBM-LO and SBM-CV (3,104 vs. 2,984 and 2,963 kcal/kg of DM). A 14-d growth performance experiment was also conducted using 120 Ross 308 male commercial broiler chicks (mean initial BW = 102.6 g) that were allotted to a completely randomized design. There were 5 chicks/pen and 8 replicate pens/diet. Three corn- and SBM-based diets were formulated based on the data for digestible AA and TME(n) that were measured in the previous experiments. Each source of SBM was used in 1 diet, but because of the greater concentrations of digestible AA in SBM-HP and SBM-LO than in SBM-CV, the inclusion of SBM-HP and SBM-LO were 31.21 and 32.60%, respectively, whereas an inclusion of 38.21% SBM-CV was used. There were no differences among the 3 diets for BW gain or feed efficiency, which indicated that the reduced inclusion rates of SBM-HP and SBM-LO compared with SBM-CV were not detrimental to broiler chick growth performance. It was concluded that, compared with SBM-CV, SBM-HP and SBM-LO are needed in lower concentrations in diets fed to broiler chicks because these 2 sources of SBM have a greater nutritional value than does SBM-CV.

Amino acid digestibility and concentration of digestible and metabolizable energy in soybean meal produced from conventional, high-protein, or low-oligosaccharide varieties of soybeans and fed to growing pigs

Two experiments were conducted to determine AA digestibility and the concentration of DE and ME in 5 sources of soybean meal (SBM). The 5 sources included hexane-extracted SBM produced from high-protein soybeans (SBM-HP) and conventional soybeans (SBM-CONV), and mechanically extruded-expelled SBM produced from high-protein soybeans (EE-SBM-HP), low-oligosaccharide soybeans (EE-SBM-LO), and conventional soybeans (EE-SBM-CONV). Five diets that each contained 1 source of SBM and a N-free diet were used in Exp. 1 to determine AA digestibility in each meal. Twelve growing barrows (initial BW: 67.7 +/- 1.34 kg) were allotted to a replicated 6 x 6 Latin square design with 6 periods and 6 diets in each square. Each period lasted 7 d, and ileal digesta were collected on d 6 and 7 of each period. Results of the experiment showed that the standardized ileal digestibility (SID) of all AA except Trp was similar for SBM-HP and SBM-CONV, but EE-SBM-HP and EE-SBM-LO had greater (P < 0.05) SID of His, Ile, Lys, Thr, and Val than EE-SBM-CONV. The SID of all indispensable AA in EE-SBM-HP was greater (P < 0.05) than in SBM-HP. The SID of Arg, Ile, Leu, and Phe in EE-SBM-CONV was greater (P < 0.05) than in SBM-CONV, but the SID of Trp was also greater (P < 0.05) in SBM-CONV than in EE-SBM-CONV. Experiment 2 was conducted to measure DE and ME in the same 5 sources of SBM as used in Exp. 1. Forty-eight growing barrows (initial BW: 38.6 +/- 3.46 kg) were placed in metabolism cages and randomly allotted to 6 diets with 8 replicates per diet. A corn-based diet and 5 diets based on a mixture of corn and each source of SBM were formulated. Urine and feces were collected during a 5-d collection period, and values for DE and ME in each source of SBM were calculated using the difference procedure. Results showed that the ME in SBM-HP tended to be greater (P = 0.10) than in SBM-CONV (4,074 vs. 3,672 kcal/kg of DM). The ME in EE-SBM-HP also tended to be greater (P = 0.10) than in EE-SBM-CONV and in EE-SBM-LO (4,069 vs. 3,620 and 3,721 kcal/kg of DM), but there was no difference in ME between extracted and extruded-expelled meals. It is concluded that SBM-HP has a greater feeding value than SBM-CONV because of greater concentrations of digestible AA and ME. Likewise, EE-SBM-LO has a greater concentration of most indispensable AA than EE-SBM-CONV, but the concentration of ME is similar in these 2 meals. Results of this experiment also showed that AA digestibility values in extruded-expelled SBM are greater than in hexane-extracted SBM.

Kinematic analysis of upper extremity joint motion in children using posterior walkers

This study applies an upper extremity model to analyze motion in 25 children with cerebral palsy using posterior walkers. The study indicates that throughout a gait cycle, the shoulders and wrist are in extension and the elbows are flexed. It also reveals that the elbows are the most asymmetrical joint of the upper extremities during walker-assisted ambulation.

Effect of Host Plant Resistance and Reduced Rates and Frequencies of Fungicide Application to Control Potato Late Blight

Field experiments were conducted during 1998 to 2000 to determine the response of commercial potato cultivars and advanced breeding lines (ABL) differing in susceptibility to foliar late blight (caused by Phytophthora infestans) to reduced rates and frequencies of residual, contact fungicide applications. When environmental conditions were most favorable for the development of late blight, the lowest application rate of the fungicides chlorothalonil or fluazinam (33% of the manufacturers' recommended application rate [MRAR]) gave unsatisfactory control of potato late blight. Under conditions moderately conducive for late blight development, effective control was achieved with 33 to 66% MRAR with either fungicide. The Michigan State University advanced selection, MSG274-3, was the least susceptible ABL tested and, during 1998 to 2000, late blight was effectively managed using reduced rates of fungicides. Application rates of chlorothalonil (33 to 100% MRAR) significantly reduced late blight in the cultivar Snowden (5-day application interval) compared with the nontreated control; whereas, late blight was not effectively controlled in Snowden even at 100% MRAR of chlorothalonil at either 10- or 15-day application intervals in 1999 or 2000. The ABL MSG274-3 was the least susceptible of all cultivars and ABL used in this study, and required minimal chemical protection against late blight. The study demonstrates that ABL with reduced susceptibility to late blight can be managed with reduced fungicide rates and longer application intervals, thus offering more economical control of this disease.

Role of transglutaminase II in retinoic acid-induced activation of RhoA-associated kinase-2

Transamidation is a post-translational modification of proteins mediated by tissue transglutaminase II (TGase), a GTP-binding protein, participating in signal transduction pathways as a non-conventional G-protein. Retinoic acid (RA), which is known to have a role in cell differentiation, is a potent activator of TGASE: The activation of TGase results in increased transamidation of RhoA, which is inhibited by monodansylcadaverine (MDC; an inhibitor of transglutaminase activity) and TGaseM (a TGase mutant lacking transglutaminase activity). Transamidated RhoA functions as a constitutively active G-protein, showing increased binding to its downstream target, RhoA-associated kinase-2 (ROCK-2). Upon binding to RhoA, ROCK-2 becomes autophosphorylated and demonstrates stimulated kinase activity. The RA-stimulated interaction between RhoA and ROCK-2 is blocked by MDC and TGaseM, indicating a role for transglutaminase activity in the interaction. Biochemical effects of TGase activation, coupled with the formation of stress fibers and focal adhesion complexes, are proposed to have a significant role in cell differentiation.

The effect of muscle damage on strength and fatigue deficits

Many studies have reported prolonged force deficits after a bout of resistance training. However there is a dearth of information on the neuromuscular mechanisms underlying these deficits. This study examined whether an acute bout of resistance training had prolonged detrimental effects on muscle activation and excitation-contraction coupling. Two groups of 16 subjects each were tested before resistance exercise and at 1, 3, 5, and 7 days postexercise. A dvnamic group was tested for concentric and eccentric 1 repetition maximum and 3-methylhistidine (3-MH). An isometric group was tested for maximal voluntary contraction, muscle inactivation, relative fatigue, and evoked twitch properties. Both groups experienced similar increases in pain, limb circumference, and decreased range of motion between 1 and 3 days postexercise. Decrements occurred with eccentric strength, maximal voluntary contraction, muscle inactivation, relative fatigue, twitch amplitude, and increases in 3-MH. Although muscle damage-induced characteristics (pain, swelling, range of motion, 3-MH) were not correlated with neuromuscular impairments (muscle activation, force output), disruption of excitation-contraction coupling may have contributed to decrements in fatigue.

Regulation of angiotensinogen gene expression and protein in neonatal rat cardiac fibroblasts by glucocorticoid and beta-adrenergic stimulation

We previously demonstrated the presence of components for a renin-angiotensin system in fibroblasts cultured from neonatal rat ventricles, the regulation of expression of which has not been studied. Since glucocorticoids and beta-adrenergic stimuli have been implicated in cardiac hypertrophy, and function as regulators of the circulating renin-angiotensin system, we examined the effects of dexamethasone and isoproterenol on angiotensinogen mRNA levels and protein secretion in cultured neonatal rat cardiac fibroblasts. Treatment of cardiac fibroblasts for 8 h with 10 micromol/l isoproterenol or 100 nmol/l dexamethasone increased angiotensinogen mRNA levels by 246 +/- 7% and 1406 +/- 207%, respectively. Over 24 h, dexamethasone and isoproterenol increased angiotensinogen secretion by 148 +/- 32% and 123 +/- 26%, respectively. Angiotensin II, which has been reported to be a positive regulator of angiotensinogen synthesis and secretion in liver, markedly attenuated the effects of dexamethasone and isoproterenol on angiotensinogen mRNA expression and secretion. In the presence of 1 micromol/l angiotensin II, the stimulation in angiotensinogen secretion observed with dexamethasone and isoproterenol was decreased by 62% and 76%, respectively. The negative feedback of angiotensin II on angiotensinogen expression was primarily mediated through the type one angiotensin II (AT1) receptor (IC50 = 0.30 +/- 0.02 nmol/l). In summary, results from this study demonstrate that angiotensinogen mRNA levels and protein secretion in cardiac fibroblasts are positively regulated by glucocorticoid and beta-adrenergic stimulation. In addition, angiotensinogen production by cardiac fibroblasts is under negative feedback control of angiotensin II.

Cardiotrophin-1 increases angiotensinogen mRNA in rat cardiac myocytes through STAT3 : an autocrine loop for hypertrophy

-Cardiotrophin-1, an interleukin-6-related cytokine, stimulates the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway and induces cardiac myocyte hypertrophy. In this study, we demonstrate that cardiotrophin-1 induces cardiac myocyte hypertrophy in part by upregulation of a local renin-angiotensin system through the JAK/STAT pathway. We found that cardiotrophin-1 increased angiotensinogen mRNA expression in cardiac myocytes via STAT3 activation. Tyrosine phosphorylation of STAT3 by cardiotrophin-1 treatment resulted in STAT3 homodimer binding to the St-domain in the angiotensinogen gene promoter, which lead to promoter activation in a transient transfection assay. Cardiotrophin-1-induced STAT3 tyrosine phosphorylation and binding to the St-domain were suppressed by AG490, a specific JAK2 inhibitor, which also attenuated cardiotrophin-1-stimulated angiotensinogen promoter activity. Cardiotrophin-1 did not activate the angiotensinogen gene promoter that contained a substitution mutation within the St-domain. Finally, losartan, an angiotensin II type 1 receptor antagonist, significantly attenuated cardiotrophin-1-induced hypertrophy of neonatal rat cardiac myocytes. Angiotensin II is known to induce cardiac myocyte hypertrophy by activating the G-protein-coupled angiotensin II type 1 receptor. Our results suggest that upregulation of angiotensinogen and angiotensin II production contribute to cardiotrophin-1-induced cardiac myocyte hypertrophy and emphasize an important interaction between G-protein-coupled and cytokine receptors.

Angiotensin II-stimulated induction of sis-inducing factor is mediated by pertussis toxin-insensitive G(q) proteins in cardiac myocytes

The Janus kinase-signal transducers and activators of transcription (JAK-STAT) pathway is stimulated by angiotensin II (Ang II) via the type 1 receptor after acute pressure overload in the heart. The purpose of this study was to determine whether activation of the JAK-STAT pathway by Ang II is dependent on G proteins. Ang II (100 nmol/L for 120 minutes) caused formation of sis-inducing factor (SIF) complexes and tyrosine phosphorylation of STAT proteins in neonatal rat ventricular myocytes. The percentage of change in Ang II-stimulated SIF induction was not affected by pertussis toxin (PTX) or GP antagonist-2A, compounds that inhibit activation of G(i) and G(o) proteins. In contrast, GP antagonist-2A, a peptide that selectively inhibits activation of G(q) proteins, completely abolished Ang II-stimulated SIF induction and STAT3 tyrosine phosphorylation. Pretreatment of cardiac myocytes with U73122, an inhibitor of phosphatidylinositol-specific phospholipase C (PLC) activity, decreased Ang II-stimulated SIF induction and STAT3 tyrosine phosphorylation in a dose-dependent manner. Chelation of intracellular Ca(2+) with BAPTA-AM did not alter Ang II-stimulated SIF induction. In contrast, pretreatment of cardiac myocytes with Ro-31-8220, a potent and specific inhibitor of protein kinase C (PKC), decreased Ang II-stimulated SIF induction in a dose-dependent manner. Ang II-stimulated SIF induction was abolished in cardiac myocytes after downregulation of PKC by treatment with PMA. From these data, we conclude that Ang II-stimulated SIF induction and STAT3 tyrosine phosphorylation is mediated by PTX-insensitive G proteins through a G(q)-PLC-PKC-mediated pathway in neonatal rat ventricular myocytes.

The cardiac renin-angiotensin system: conceptual, or a regulator of cardiac function?

Angiotensin II, the effector peptide of the renin-angiotensin system, regulates cellular growth in response to developmental, physiological, and pathological processes. The identification of renin-angiotensin system components and angiotensin II receptors in cardiac tissue suggests the existence of an autocrine/paracrine system that has effects independent of angiotensin II derived from the circulatory system. To be functional, a local renin-angiotensin system should produce sufficient amounts of the autocrine and/or paracrine factor to elicit biological responses, contain the final effector (angiotensin II receptor), and respond to humoral, neural, and/or mechanical stimuli. In this review, we discuss evidence for a functional cardiac renin-angiotensin system.

Amplification of angiotensin II signaling in cardiac myocytes by adenovirus-mediated overexpression of the AT1 receptor

Low levels of AT1 receptor can make studying the growth-related signal transduction events mediated by this angiotensin II receptor in cardiac myocytes technically difficult. The purpose of the present study was to establish whether an adenovirus expression system could be used to increase the number of plasma membrane AT1 receptors in neonatal rat ventricular myocytes, thereby amplifying the signaling pathways activated by this receptor. Cardiac myocytes infected with adenovirus expressing the AT1 receptor exhibited increased ligand binding. The overexpressed receptor appeared to function like the endogenous receptor, in regard to agonist-induced internalization, as well as coupling to MAPK activation and protein tyrosine phosphorylation events. In addition, adenovirus-mediated overexpression of the AT1 receptor resulted in the amplification of angiotensin II intracellular signaling. In conclusion, adenovirus-mediated overexpression of angiotensin II receptors appears to be a useful strategy for studying the signal transduction events activated by this hormone in cardiac myocytes and for unraveling the molecular means by which this receptor type couples to a hypertrophic pattern of growth and gene expression.

Paracrine actions of cardiac fibroblasts on cardiomyocytes: implications for the cardiac renin-angiotensin system

Conditioned medium of cardiac fibroblasts was found to induce protein synthesis and signal transduction events rapidly, and to increase angiotensinogen messenger RNA (mRNA) levels in neonatal rat ventricular myocytes. Within 4 hours, fibroblast-conditioned medium (FCM) stimulated protein synthesis in cardiac myocytes, independent of the contractile state, and induced marked increases within 24 hours in total protein content. Endothelin- released by cardiac fibroblasts was not responsible for the stimulation of protein synthesis. FCM rapidly activated signal transduction events in cardiac myocytes associated with hypertrophic stimuli, including: (1) increased tyrosine phosphorylation of several prominent protein bands; (2) mitogen-activated protein kinases (ERK 1 and ERK 2); and (3) protein kinase C. Finally, FCM caused an increase at 8 hours in angiotensinogen mRNA levels of cardiac myocytes, whereas no effect was observed on mRNA levels for renin or the type 1 angiotensin II receptor (AT1). Our results suggest that cardiac fibroblasts produce a factor that rapidly activates cardiac myocyte growth through a membrane receptor that couples to conventional signal transduction pathways.

Highly corrected close-packed microlens arrays and moth-eye structuring on curved surfaces

The fabrication of near-micrometer-sized close-packed coherent microlens arrays on spheric or aspheric surfaces has been accomplished by use of a compact holographic projector system that was developed for producing multimicrometer down to submicrometer grid patterning on curved surfaces. The microlens arrays, which can be utilized as moth-eye relief structures, are formed in a photoimageable bisbenzocyclobutene polymeric resin by a photolytic process involving standing-wave interference patterns from the holographic projector system. Because of absorption, each integral microlenslet of the finished arrays possesses a near-paraboloid contour. The trajectories of the meridional rays from each microlenslet can be optimized to intersect at either a single point or a locus of points.

Highly corrected submicrometer grid patterning on curved surfaces

A compact holographic projector system was built and tested. This projection system offers a practical approach for making a highly corrected mesh or grid pattern on curved surfaces. The pattern can range in size from multimicrometer to submicrometer dimensions and be recorded in either positive or negative photoresist. Standing-wave interference patterns in the form of a diverging close-packed lattice of either hexagonal or square rodlike intensity maxima extending outward from a point or a locus of points are produced by multiple-beam holography that involves the combination of a holographic diffraction grating and a hypercomatic focusing objective.

Cross-talk between angiotensin II and interleukin-6-induced signaling through Stat3 transcription factor

In cultured neonatal rat cardiac fibroblasts and CHO-K1 cells expressing angiotensin II (Ang II) type 1 receptors (AT1) (T3CHO/AT1A cell line), Ang II induced a delayed tyrosine phosphorylation of Stat3 (Signal Transducers and Activators of Transcription) with maximal activation at 2 h. This was in contrast to the rapid tyrosine phosphorylation (15-30 min) of Stat3 by the cytokine interleukin-6 (IL-6). Using T3CHO/AT1A cells, we tested the hypothesis that the delayed tyrosine phosphorylation of Stat3 by Ang II resulted from the induction of an inhibitory pathway (0-30 min) prior to activation (1-2 h). In support of this hypothesis, we observed that a short treatment of cells with Ang II transiently inhibited the IL-6-induced Stat3 tyrosine phosphorylation. The inhibitory effect of Ang II could be attenuated by exposing the cells to a specific inhibitor of MAP kinase kinase 1, PD98059. Such modulatory cross-talk between Ang II and IL-6 may have relevance in pathophysiological conditions such as cardiac hypertrophy, and in acute phase and inflammatory responses.

Phosphorylation of the angiotensin II (AT1A) receptor carboxyl terminus: a role in receptor endocytosis

The molecular mechanism of angiotensin II type I receptor (AT1) endocytosis is obscure, although the identification of an important serine/threonine rich region (Thr332Lys333Met334Ser335Thr336Leu337 Ser338) within the carboxyl terminus of the AT1A receptor subtype suggests that phosphorylation may be involved. In this study, we examined the phosphorylation and internalization of full-length AT1A receptors and compared this to receptors with truncations and mutations of the carboxyl terminus. Epitope-tagged full-length AT1A receptors, when transiently transfected in Chinese hamster ovary (CHO)-K1 cells, displayed a basal level of phosphorylation that was significantly enhanced by angiotensin II (Ang II) stimulation. Phosphorylation of AT1A receptors was progressively reduced by serial truncation of the carboxyl terminus, and truncation to Lys325, which removed the last 34 amino acids, almost completely inhibited Ang II-stimulated 32P incorporation into the AT1A receptor. To investigate the correlation between receptor phosphorylation and endocytosis, an epitope-tagged mutant receptor was produced, in which the carboxyl-terminal residues, Thr332, Ser335, Thr336, and Ser338, previously identified as important for receptor internalization, were substituted with alanine. Compared with the wild-type receptor, this mutant displayed a clear reduction in Ang II-stimulated phosphorylation. Such a correlation was further strengthened by the novel observation that the Ang II peptide antagonist, Sar(1)Ile8-Ang II, which paradoxically causes internalization of wild-type AT1A receptors, also promoted their phosphorylation. In an attempt to directly relate phosphorylation of the carboxyl terminus to endocytosis, the internalization kinetics of wild-type AT1A receptors and receptors mutated within the Thr332-Ser338 region were compared. The four putative phosphorylation sites (Thr332, Ser335, Thr336, and Ser338) were substituted with either neutral [alanine (A)] or acidic amino acids [glutamic acid (E) and aspartic acid (D)], the former to prevent phosphorylation and the latter to reproduce the acidic charge created by phosphorylation. Wild-type AT1A receptors, expressed in Chinese hamster ovary cells, rapidly internalized after Ang II stimulation [t1/2 2.3 min; maximal level of internalization (Ymax) 78.2%], as did mutant receptors carrying single acidic substitutions (T332E, t1/2 2.7 min, Ymax 76.3%; S335D, t1/2 2.4 min, Ymax 76.7%; T336E, t1/2 2.5 min, Ymax 78.2%; S338D, t1/2 2.6 min, Ymax 78.4%). While acidic amino acid substitutions may simply be not as structurally disruptive as alanine mutations, we interpret the tolerance of a negative charge in this region as suggestive that phosphorylation may permit maximal internalization. Substitution of all four residues to alanine produced a receptor with markedly reduced internalization kinetics (T332A/S335A/T336A/S338A, t1/2 10.1 min, Ymax 47.9%), while endocytosis was significantly rescued in the corresponding quadruple acidic mutant (T332E/S335D/T336E/S338D, t1/2 6.4 min, Ymax 53.4%). Double mutation of S335 and T336 to alanine also diminished the rate and extent of endocytosis (S335A/T336A, 3.9 min, Ymax 69.3%), while the analogous double acidic mutant displayed wild type-like endocytotic parameters (S335D/T336E, t1/2 2.6 min, Ymax 77.5%). Based on the apparent rescue of internalization by acidic amino acid substitutions in a region that we have identified as a site of Ang II-induced phosphorylation, we conclude that maximal endocytosis of the AT1A receptor requires phosphorylation within this serine/threonine-rich segment of the carboxyl terminus.

Half-Fourier RARE MR cholangiopancreatography: experience in 300 subjects

PURPOSE

To determine prospectively the clinical applications and diagnostic accuracy of half-Fourier rapid acquisition with relaxation enhancement (RARE) magnetic resonance (MR) cholangiopancreatography (MRCP) in a large patient population.

MATERIALS AND METHODS

Breath-hold, heavily T2-weighted half-Fourier RARE MRCP was performed in 265 patients with suspected pancreaticobiliary disease and in 35 control patients without symptoms or signs referrable to the biliary tract or pancreatic duct. MRCP findings were correlated with those at direct cholangiography, pathologic examination, cross-sectional imaging, and clinical follow-up.

RESULTS

Diagnostic MRCP examinations were obtained in 299 (99.7%) subjects. MRCP yielded an accuracy of 100% in determining the presence of pancreaticobiliary disease, the presence and level of biliary obstruction, and obstruction due to bile duct calculi. The accuracy of MRCP and MR imaging in determining the presence and level of malignant obstruction was 98.2%. MRCP obviated endoscopic retrograde cholangiopancreatography (ERCP) by excluding choledocholithiasis in patients with acute pancreatitis (n = 13) and nonspecific abdominal pain (n = 82). In patients with sclerosing cholangitis and acquired immunodeficiency syndrome cholangiopathy, MRCP depicted the biliary tract as clearly as did ERCP (n = 9). After failed ERCP, MRCP delineated the pancreaticobiliary tract and helped determine therapeutic options (n = 27).

CONCLUSION

Half-Fourier RARE MRCP enables accurate evaluation of pancreaticobiliary disease and obviates ERCP in some patients.

alpha-Thrombin inhibits signal transducers and activators of transcription 3 signaling by interleukin-6, leukemia inhibitory factor, and ciliary neurotrophic factor in CCL39 cells

We recently demonstrated that, in rat aortic smooth muscle cells, alpha-thrombin stimulated Stat3/SIF-A (signal transducers and activators of transcription 3/sis-inducing factor-A) activity [G. J. Bhat et al. (1997) Hypertension 29(Pt. 2), 356-360]. In the present study, we observed that exposure of CCL39 cells (a Chinese hamster lung fibroblast cell line) to alpha-thrombin resulted in a time-dependent decrease in basal SIF-A activity. We hypothesized that the decrease in basal SIF-A was due to the initiation of an inhibitory pathway, following alpha-thrombin exposure. To test this hypothesis, we determined if alpha-thrombin would inhibit Stat3 and SIF-A activation by interleukin-6 (IL-6), leukemia inhibitory factor (LIF), and ciliary neurotrophic factor (CNTF). In support of this hypothesis, alpha-thrombin inhibited the Stat3/SIF-A response induced by all the above cytokines. The inhibition by alpha-thrombin was concentration dependent, was sensitive to hirudin, and was mimicked by the thrombin receptor agonist peptide. The inhibition did not require the activation of phorbol 12-myristate 13-acetate-sensitive isoforms of protein kinase C and was reversed by pretreatment with the mitogen-activated protein kinase kinase 1 (MAPKK1 or MEK1) inhibitor PD98059. Inhibitory cross talk between alpha-thrombin and IL-6 was also observed in MRC-5 cells, a fibroblast cell line derived from human lung tissue. Thus, we identify a novel alpha-thrombin inhibitory pathway which, acting through a MAPKK1-dependent mechanism, blocks IL-6-, LIF-, and CNTF-induced Stat3/SIF-A activation. This inhibitory cross talk may provide an important regulatory function to modulate gene transcription by these cytokines, during immune and inflammatory responses.