Quantification of mechanical properties in long-term in vivo used silicone catheter lines according to DIN 10555-3.

BACKGROUND: Totally implantable central venous access port devices are crucial for intravenous application of chemotherapeutics and long-term therapy for chronic disease. Common complications include thrombosis and device fracture related to altered material properties through exposure in situ. This study exhibits whether uniaxial tensile properties (DIN 10555-3) of in vivo used catheters prove inferior to unused catheters. MATERIAL AND METHODS: 5 unused, originally packed silicone catheters were cut into 6 segments of 50 mm: 3 segments each were cleaned via cleaning solution (n = 15) while 3 segments were left unattended (n = 15). Distal segments (50 mm) of long-term in vivo used silicone catheters were cleaned before testing (n = 33). Overall mechanical behavior was tested in a custom-made self-centering, torsion free carrier. Maximum force stress at failure, strain at failure and Young's modulus were determined and statistically analyzed. FINDINGS: Unused catheters showed no significant difference in testing. in vivo used catheters exhibited 20% lower maximal force than unused catheters (p < 0.001), strain at break (p ã€ˆ0,001), and 7% higher elastic modulus (p = 0.004; power: 0.845). Due to a constant cross section area, stress at failure was proportional to maximum force (p < 0.001). Relation between determined parameters and dwell times was non-significant. INTERPRETATION: In vivo long-term used silicone catheters showed significantly lower ultimate strength than unused ones. It is likely that in situ altering changes the mechanical properties of catheters and may potentially lead to failure.

Polyphosphate (PolyP) for alveolar cleft repair: study protocol for a pilot randomized controlled trial.

OBJECTIVE: Bone grafting is an important surgical procedure to restore missing bone in patients with alveolar cleft lip/palate, aiming to stabilize either sides of the maxillary segments by inducing new bone formation, and in bilateral cleft cases also to stabilize the pre-maxilla. Polyphosphate (PolyP), a physiological polymer composed of orthophosphate units linked together with high-energy phosphate bonds, is a naturally existing compound in platelets which, when complexed with calcium as Ca-polyP microparticles (Ca-polyP MPs), was proven to have osteoinductive properties in preclinical studies. AIM: To evaluate the feasibility, safety, and osteoinductivity of Ca-polyP MPs as a bone-inducing graft material in humans. METHODS: This prospective non-blinded first-in-man clinical pilot study shall consist of 8 alveolar cleft patients of 13 years or older to evaluate the feasibility and safety of Ca-PolyP MPs as a bone-inducing graft material. Patients will receive Ca-polyP graft material only or Ca-polyP in combination with biphasic calcium phosphate (BCP) as a bone substitute carrier. During the trial, the participants will be investigated closely for safety parameters using radiographic imaging, regular blood tests, and physical examinations. After 6 months, a hollow drill will be used to prepare the implantation site to obtain a biopsy. The radiographic imaging will be used for clinical evaluation; the biopsy will be processed for histological/histomorphometric evaluation of bone formation. DISCUSSION: This is the first-in-man study evaluating the safety and feasibility of the polyP as well as the potential regenerative capacity of polyP using an alveolar cleft model. TRIAL REGISTRATION: Indonesian Trial Registry INA-EW74C1N . Registered on 12 June 2020.

Family-based intervention to prevent childhood obesity among school-age children of low socioeconomic status: study protocol of the FIVALIN project.

BACKGROUND: Childhood obesity represents a global public health crisis: the number of obese children and adolescents (aged 5-19 years) worldwide has risen tenfold in the past four decades. The vast majority of overweight and obese children live in high-income countries, and low socio-economic status (SES) is a significant risk factor. Family Based Interventions (FBI) have demonstrated positive results in preventing obesity, although these results are strongly influenced by SES. Moreover, we still poorly understand how FBI can determine a positive trend in weight status in low-income communities. Therefore, there is an urgent need to define and evaluate innovative and multi-target projects to reduce obesity risk behaviors and health inequalities and the present study aims to present the study protocol of FIVALIN a FBI that pretends to achieve this goal. METHODS: We will conduct a quasi-experimental design within 60 Community Child Centers (CCC) in Barcelona metropolitan area. Each cluster (CCC) will be assigned by convenience to the intervention and control groups. For the whole study, a total of 810 children aged 8-12 years and 600 parents will be recruited during 3 consecutive editions (1st - 2019/2020; 2nd - 2020/2021; 3rd - 2021/2022) of 10 months each. The action is a regular multicomponent health-promotion intervention targeting children, families, and CCC. All activities are based on the Motivational Interviewing (MI) approach and will focus on promoting good dietary habits, physical activity, appropriate screen time and sleep duration, and psychological well-being. The control group participate in a unique workshop on general awareness of healthy lifestyles for families. We will perform a comparative analysis of the evolution of weight status, healthy lifestyles, and socioeconomic variables, between the intervention and control groups. DISCUSSION: There is a need for more evidence on how to target and evaluate holistic interventions in low SES families. Our multi-targeting intervention for obesity prevention tackles risky behaviors that go beyond diet and physical activity (PA). Therefore, future interventions can effectively promote all the behavioral domains that determine trends in the weight status. TRIAL REGISTRATION: ISRCTN Registry: ISRCRN12682870 . Registered 9 July 2020. Retrospectively registered. Protocol version: 30 April 2021, version 5.

Halo effect of a Mediterranean-lifestyle weight-loss intervention on untreated family members' weight and physical activity: a prospective study.

OBJECTIVES: Obesity is subject to strong family clustering. The relatives of participants in weight-loss interventions may also modify their lifestyle and lose weight. The aim of this study was to examine the presence and magnitude of a halo effect in untreated family members of participants enrolled in a randomized, multi-component, lifestyle intervention. METHODS: A total of 148 untreated adult family members of participants in an intensive weight-loss lifestyle intervention (the PREDIMED-Plus study) were included. Changes at 1 and 2 years in body weight, physical activity, and adherence to a traditional Mediterranean diet (MedDiet) were measured. Generalized linear mixed models were used to assess whether the change differed between family members of the intervention group compared to the control. RESULTS: Untreated family members from the intervention group displayed a greater weight loss than those from the control after 1 and 2 years: adjusted 2-year weight change difference between groups was -3.98 (SE 1.10) kg (p < 0.001). There was a halo effect with regard to adherence to the MedDiet at one year which was sustained at two years: 2-year adjusted difference in MedDiet score change +3.25 (SE 0.46) (p < 0.001). In contrast, no halo effect was observed with regard to physical activity, as the untreated family members did not substantially modify their physical activity levels in either group, and the adjusted difference at two years between the 2 groups was -272 (SE 624) METs.min/week (p = 0.665). CONCLUSIONS: In the first prospective study to assess the influence on untreated family members of a diet and physical activity weight-loss intervention, we found evidence of a halo effect in relatives on weight loss and improvement in adherence to a MedDiet, but not on physical activity. The expansion of MedDiet changes from individuals involved in a weight-loss intervention to their family members can be a facilitator for obesity prevention.

[When emergency physician and tele-emergency physician save life together : A case description on the application of prehospital telemedicine for ventricular tachycardia with hemodynamic instability]. / Wenn Notarzt und Telenotarzt gemeinsam Leben retten : Eine Fallbeschreibung für die Anwendung der prähospitalen Telemedizin bei einer kreislaufinstabilen ventrikulären Tachykardie.

Telemedicine has already entered the rescue service in some regions of Germany. This case description is about a telemedical emergency physician case where an emergency doctor was also at the scene of the emergency. The patient had a life-threatening ventricular tachycardia and became hemodynamically unstable. The emergency physician was still inexperienced and overwhelmed by the complex situation. She decided to contact the tele-emergency medical services (tele-ems) and could then be instructed to perform intraosseous access, drug treatment and electrical cardioversion in the unstable patient. The cooperation with the tele-ems physician enabled the still inexperienced emergency physician to perform a guideline-compliant treatment and to transport the stabilized patient to the hospital in a timely manner.

[Appropriate allocation of resources for interhospital transfer in emergency medical service-is a physician in the dispatch center helpful?] / Indikationsgerechte Durchführung von Sekundärtransporten im Rettungsdienst ­ Hilft der Arzt in der Leitstelle?

BACKGROUND: The number of interhospital transfers is constantly increasing because of specialization of medical facilities, capacity balancing between intensive care units as well as earlier rehabilitation procedures. This leads to an increase in requests for emergency physicians to accompany patient transfers. This study investigated whether clarification of interhospital transport by an emergency physician at the dispatch center can optimize the use of emergency services resources. METHOD: All transport clarifications performed by a tele-emergency physician between 1 January 2018 and 31 December 2019 were retrospectively analyzed as well as the transport request forms. Furthermore, all data on the number and alarmed rescue resources for interhospital transfers in the city of Aachen from 2013 onwards were exported from the dispatch center databank and included in the evaluation. RESULTS: In total 2333 requests for interhospital patient transfers from 2018 and 2019 were analyzed as well as 10,923 transports recorded from 2013 to 2019. The number of patient transfers accompanied by an emergency physician from 2013 to 2019 was significantly reduced from 786 (68.2%) to 495 (30.5%, p > 0.001). The correct resources of rescue vehicles and staff was requested in 1816 cases (77.8%). The urgency of emergency patient transfers was correctly evaluated in 567 (89.2%) cases. In total 526 assignments were carried out without an emergency physician and 315 of these patients were accompanied by a tele-emergency physician during transfer. CONCLUSION: The immediate clarification of interhospital transport requests by an emergency physician at the dispatch center leads to a significant reduction in unnecessary medical accompaniment of patient transfers. The choice of an appropriate transfer vehicle and staff should not be left to the requesting hospital physician alone.

Low-dose strength training in addition to neuromuscular exercise and education in patients with knee osteoarthritis in secondary care - a randomized controlled trial.

OBJECTIVES: To investigate the effects of lower limb strength training in addition to neuromuscular exercise and education (ST + NEMEX-EDU) compared to neuromuscular exercise and education alone (NEMEX-EDU) on self-reported physical function in patients with knee osteoarthritis (KOA). DESIGN: Patient-blinded, parallel-group randomized controlled trial (RCT). METHODS: The trial included 90 patients in secondary care with radiographic and symptomatic KOA, ineligible for knee replacement. Both groups exercised twice weekly for 12 weeks. Additional strength training consisted of a single, fatiguing knee extension set (30-60RM) before four sets of leg-press (8-12RM). Primary outcome was the between-group difference on the subscale activities of daily living from the Knee Injury and Osteoarthritis Outcome Score (KOOSADL) at 12 weeks. Secondary outcomes included KOOS symptoms, pain, function in sport and recreation, and quality of life, 40 m walk, stair climb, leg extension power, EuroQol-5D-5L, pain medication usage, and adverse events. RESULTS: There was no statistically significant between-group difference in KOOSADL at 12-weeks; adjusted mean difference -1.15 (-6.78 to 4.48). Except for the stair climb test, which demonstrated an adjusted mean difference of 1.15 (0.09-2.21) in favor of ST + NEMEX-EDU, all other outcomes showed no statistically significant between-group differences. Neither group improved leg extension power. CONCLUSION: The addition of lower-limb strength training, using a low-dose approach, to neuromuscular exercise and education carried no additional benefits on self-reported physical function or on most secondary outcomes. Both groups displayed similar improvements at 12-week follow-up. Hence, the current low-dose strength training approach provided no additional clinical value in this group of KOA patients. Trial identifier (ClinicalTrials.gov): NCT03215602.

Longitudinal changes in Mediterranean diet and transition between different obesity phenotypes.

BACKGROUND & AIMS: Little is known about the impact of specific dietary patterns on the development of obesity phenotypes. We aimed to determine the association of longitudinal changes in adherence to the traditional Mediterranean diet (MedDiet) with the transition between different obesity phenotypes. METHODS: Data of 5801 older men and women at high cardiovascular risk from PREDIMED trial were used. Adherence to MedDiet was measured with the validated 14p-Mediterranean Diet Adherence Screener (MEDAS). Using the simultaneous combination of metabolic health- and body size-related parameters participants were categorized into one of four phenotypes: metabolically healthy and abnormal obese (MHO and MAO), metabolically healthy and abnormal non-obese (MHNO and MANO). Cox regression models with yearly repeated measures during 5-year of follow-up were built with use of Markov chain assumption. RESULTS: Each 2-point increase in MEDAS was associated with the following transitions: in MAO participants, with a 16% (95% CI 3-31%) greater likelihood of becoming MHO; in MHO participants with a 14% (3-23%) lower risk of becoming MAO; in MHNO participants with a 18% (5-30%) lower risk of becoming MHO. In MANO women, but not in men, MEDAS was associated with 20% (5-38%) greater likely of becoming MHNO (p for interaction by gender 0.014). No other significant associations were observed. CONCLUSIONS: Better adherence to the traditional MedDiet is associated with transitions to healthier phenotypes, promoting metabolic health improvement in MAO, MANO (only in women), and MHO, as well as protecting against obesity incidence in MHNO subjects.

Early changes in tests of peripheral nerve function during oxaliplatin treatment and their correlation with chemotherapy-induced polyneuropathy symptoms and signs.

BACKGROUND AND PURPOSE: Assessment of the severity of chronic peripheral neuropathy during oxaliplatin treatment is based on symptoms. Efforts to adjust the total dose of oxaliplatin to prevent severe neuropathy can be complicated by the worsening of neuropathy symptoms following treatment. Objective measures of the structure and function of peripheral nerves during early phases of treatment may aid in determining the optimal oxaliplatin dose in individual patients. Intraepidermal nerve fibre density (IENFD) has been suggested as an early marker of peripheral neuropathy. METHODS: Sixty patients were examined before treatment and following 25% and 50% of the total planned oxaliplatin dose. Fifty-five of them were also examined at completion of chemotherapy and 6 months later. IENFD in skin biopsies from the distal leg, nerve conduction studies and quantitative sensory testing at the dorsum of the foot were performed. Forty-six healthy subjects were examined at baseline and after 6 and 52 weeks for comparison. RESULTS: Intraepidermal nerve fibre density was not reduced during treatment. Sural nerve amplitude and conduction velocity, vibration detection thresholds, mechanical detection threshold and cold detection threshold were significantly reduced during treatment. Compared to reference values and spontaneous changes in healthy subjects, the largest proportions of patients with deterioration were found for vibration detection thresholds followed by nerve conduction studies, mechanical detection threshold, cold detection threshold and IENFD. CONCLUSIONS: Significant changes were most pronounced for measures of large nerve fibre function, especially vibration sensation. Skin biopsies do not seem to provide a clinically relevant objective measure of peripheral nerve deterioration during oxaliplatin treatment.

[Analgesia in the emergency medical service: comparison between tele-emergency physician and call back procedure with respect to application safety, effectiveness and tolerance]. / Analgesie im Rettungsdienst: Vergleich zwischen Telenotarzt- und Callback-Verfahren hinsichtlich Anwendungssicherheit, Wirksamkeit und Verträglichkeit.

BACKGROUND: Acute pain is a common reason for calling emergency medical services (EMS) and can require medication depending on the pain intensity. German EMS personnel feel strong pressure to reduce a patient's pain but are restricted by law. Currently, German federal law only allows the administration of opioid-containing drugs by or on the order of a physician, while in other European countries (e.g. Switzerland and The Netherlands) the administration of opioid-based analgesia by trained and certified paramedics is common practice. Consequently, a patient in Germany experiencing acute pain needs the attendance of an emergency physician in EMS missions. According to international standards pain reduction on the numeric rating scale (NRS) score by ≥2 or a NRS score ≤4 at the end of the patient transport is considered to be adequate. OBJECTIVE: Comparison of two different algorithm-based concepts for analgesia with consultation of a physician analyzing the efficacy, tolerance and safety of application. MATERIAL AND METHODS: In a retrospective cohort study in two different regions, two physician-supported algorithm-based analgesia concepts, a call back-supported concept (EMS Schleswig-Holstein: RKiSH) and a tele-EMS physician-based concept (EMS Aachen: RDAC), were compared over 2 years. The call back-supported concept is based on specific algorithms and certification of EMS personnel. In Aachen, the tele-EMS physician is integrated into the routine EMS system and includes immediate vital data transmission. RESULTS: Over a period of 2 years call back-supported analgesia was administered in 878 cases (2016: 428, 2017: 450) and telemedically assisted analgesia was used in 728 cases (2015: 226, 2016: 502). Call back vs. telemedicine: initial NRS scores were 9 (8-10) and 8 (6-9), respectively (p < 0.0001); NRS scores were reduced by 4 (3-5) and 5 (3-6), respectively (p = 0.0002), leading to mean NRS scores of 4 (3-6) vs. 3 (2-4), respectively (p < 0.0001) at patient handover/emergency room arrival. Clinically relevant pain reduction was achieved in both groups. Complete NRS documentation was conducted in 753 (85.8%) vs. 673 (92.4%) cases, respectively, p = 0. Severe adverse events did not occur in either of the groups. CONCLUSION: The administration of analgesia by EMS personnel with teleconsultation of a physician is effective and has a low rate of complications, particularly morphine. Overall, algorithm-based call back-supported as well as telemedically supported analgesia concepts based on regular training improve the management of pain in the prehospital setting. In addition, the resources of the emergency physician remain available for life-threatening emergencies. The training, certification and supervision of EMS personnel is very important in both systems to ensure the best pain management care and patient safety. Adjustments to the federal law on the administration of analgesics would facilitate the realization of algorithm-based concepts by paramedics as pain reduction could be performed with delegation by a medical director without consulting another physician.

Mismatch 'never events' in hip and knee arthroplasty: a cohort and intervention study.

AIMS: The aim of this study was to give estimates of the incidence of component incompatibility in hip and knee arthroplasty and to test the effect of an online, real-time compatibility check. MATERIALS AND METHODS: Intraoperative barcode registration of arthroplasty implants was introduced in Denmark in 2013. We developed a compatibility database and, from May 2017, real-time compatibility checking was implemented and became part of the registration. We defined four classes of component incompatibility: A-I, A-II, B-I, and B-II, depending on an assessment of the level of risk to the patient (A/B), and on whether incompatibility was knowingly accepted (I/II). RESULTS: A total of 26 524 arthroplasties were analyzed. From 12 307 procedures that were undertaken before implementation of the compatibility check, 21 class A incompatibilities were identified (real- or high-risk combinations; 0.17%; 95% confidence interval (CI) 0.11 to 0.26). From 5692 hip and 6615 knee procedures prior to implementation of the compatibility check, we found rates of class A-I incompatibility (real- or high-risk combinations unknowingly inserted) of 0.14% (95% CI 0.06 to 0.28) and 0.17% (95% CI 0.08 to 0.30), respectively. From 14 217 procedures after the introduction of compatibility checking (7187 hips and 7030 knees), eight class A incompatibilities (0.06%; 95% CI 0.02 to 0.11) were identified. This difference was statistically significant (p = 0.008). CONCLUSION: Our data presents validated estimates of the baseline incidence of incompatibility events for hip and knee arthroplasty procedures and shows that a significant reduction in class A incompatibility events is possible using a web-based recording system. Cite this article: Bone Joint J 2019;101-B:960-969.

Photochemical multivariate curve resolution models for the investigation of photochromic systems under continuous irradiation.

We propose a multivariate curve resolution approach for the investigation of photochromic systems using UV-Visible spectroscopy. The incorporation of photochemical hard-models as constraints in multivariate curve resolution alternating least squares (MCR-ALS) allows extracting reaction quantum yields in situations where a complete knowledge of the system is not available. We apply this approach to the study of the photochromism of CMTE (cis-1,2-dicyano-1,2-bis(2,4,5-trimethyl-3-thienyl)ethene) under continuous monochromatic irradiation. The mechanism, involving 3 species and 2 reversible reactions, is written and translated into a kinetic constraint that can be applied to the concentration profiles within ALS. First, ambiguity of the solution obtained for photochemical model(s) is calculated and discussed for single set analysis. Multiset analysis is then proposed combining data obtained under different irradiation wavelengths to provide more reliable results. Finally, the photochemical reactivity of CMTE is widely unraveled, and some description of the mechanism observed under irradiation at 365 nm is given.

Fermented dairy products, diet quality, and cardio-metabolic profile of a Mediterranean cohort at high cardiovascular risk.

BACKGROUND AND AIMS: Fermented dairy products have been associated with a better diet quality and cardio-metabolic profile. However, in Mediterranean populations, these associations have not been well characterized. The aim of this study was to assess the diet quality and the associations between the consumption of total fermented dairy products and their subtypes and the prevalence of Metabolic Syndrome (MetS) components in a Mediterranean population at high cardiovascular risk. METHODS AND RESULTS: Baseline cross-sectional analyses were conducted on 6,572 men and women (mean age: 65 years) with overweight or obesity and MetS recruited into the PREDIMED-Plus cohort. A 143-item Food Frequency Questionnaire (FFQ) was used, and anthropometrical, biochemical, and blood pressure measurements were recorded. Multivariate-adjusted Cox regressions were fitted to analyze the association between quartiles of consumption of fermented dairy products and their subtypes and MetS components to estimate the relative risk (RR) and 95% confidence intervals (95% CIs). Participants who were high consumers of fermented dairy products reported a higher consumption of fruit, vegetables, fish, nuts, and whole bread and a lower consumption of white bread, alcohol, and cookies. Participants in the higher quartile showed a lower prevalence of the low HDL-cholesterol component of the MetS (RR=0.88; 95% CI: 0.78-0.98) than those in the lowest quartile of cheese consumption. Cheese consumption was inversely associated with the prevalence of hypertriglyceridemia. Total fermented dairy products, yogurt, and its types were not associated with any of the MetS components. CONCLUSIONS: Compared to nonconsumers, participants consuming fermented dairy products reported a better diet quality and, particularly, cheese consumers presented a lower prevalence of hypertriglyceridemia and low HDL-cholesterol plasma levels, which are MetS components.

Plasma gelsolin promotes re-epithelialization.

Woundhealing disorders characterized by impaired or delayed re-epithelialization are a serious medical problem that is painful and difficult to treat. Gelsolin (GSN), a known actin modulator, supports epithelial cell regeneration and apoptosis. The aim of this study was to estimate the potential of recombinant gelsolin (rhu-pGSN) for ocular surface regeneration to establish a novel therapy for delayed or complicated wound healing. We analyzed the influence of gelsolin on cell proliferation and wound healing in vitro, in vivo/ex vivo and by gene knockdown. Gelsolin is expressed in all tested tissues of the ocular system as shown by molecular analysis. The concentration of GSN is significantly increased in tear fluid samples of patients with dry eye disease. rhu-pGSN induces cell proliferation and faster wound healing in vitro as well as in vivo/ex vivo. TGF-ß dependent transcription of SMA is significantly decreased after GSN gene knockdown. Gelsolin is an inherent protein of the ocular system and is secreted into the tear fluid. Our results show a positive effect on corneal cell proliferation and wound healing. Furthermore, GSN regulates the synthesis of SMA in myofibroblasts, which establishes GSN as a key protein of TGF-ß dependent cell differentiation.

Time-resolved electron spectroscopy for chemical analysis of photodissociation: Photoelectron spectra of Fe(CO)5, Fe(CO)4, and Fe(CO)3.

The prototypical photoinduced dissociation of Fe(CO)5 in the gas phase is used to test time-resolved x-ray photoelectron spectroscopy for studying photochemical reactions. Upon one-photon excitation at 266 nm, Fe(CO)5 successively dissociates to Fe(CO)4 and Fe(CO)3 along a pathway where both fragments retain the singlet multiplicity of Fe(CO)5. The x-ray free-electron laser FLASH is used to probe the reaction intermediates Fe(CO)4 and Fe(CO)3 with time-resolved valence and core-level photoelectron spectroscopy, and experimental results are interpreted with ab initio quantum chemical calculations. Changes in the valence photoelectron spectra are shown to reflect changes in the valence-orbital interactions upon Fe-CO dissociation, thereby validating fundamental theoretical concepts in Fe-CO bonding. Chemical shifts of CO 3σ inner-valence and Fe 3p core-level binding energies are shown to correlate with changes in the coordination number of the Fe center. We interpret this with coordination-dependent charge localization and core-hole screening based on calculated changes in electron densities upon core-hole creation in the final ionic states. This extends the established capabilities of steady-state electron spectroscopy for chemical analysis to time-resolved investigations. It could also serve as a benchmark for how charge and spin density changes in molecular dissociation and excited-state dynamics are expressed in valence and core-level photoelectron spectroscopy.

Test method for mechanical properties of implantable catheters according to DIN 10555-3.

To enable causal analysis of port catheter failure, this study aimed to develop an experimental setup for uniaxial tensile tests that addresses the specific requirements of highly elastic medical catheters; and to quantify parameters of the catheters' mechanical competence with respect to effects of artificial aging. Segments of 6F-polyurethane catheters were tested in their native status, after chemical and after mechanical aging. Tension experiments were performed with a rate of 220 mm/min until catheter failure. Material behavior was analyzed based on load cell measurements of the universal test system and an additional optical distance registration. The Young's modulus, the ultimate stress and the ultimate strain were determined. Chemical aging significantly decreased Young's modulus (84%; p = 0.001) and ultimate stress (83%; p < 0.001), whereas mechanical aged samples demonstrated similar results for the Young's modulus (p = 0.772) and a non-significant rise of ultimate stress (13%; p = 0.128). Ultimate strain did not differ significantly regardless of the pretreatment. The results proof reliability, reproducibility and sensitivity to quantify artificial aging induced variations and also promise to detect deviations in material features caused by long-term clinical usage of catheters.

Mitochondria, glycogen, and lipid droplets in skeletal muscle during testosterone treatment and strength training: a randomized, double-blinded, placebo-controlled trial.

Low testosterone levels in aging men are associated with insulin resistance. Mitochondrial dysfunction, changes in glycogen metabolism, and lipid accumulation are linked to insulin resistance in skeletal muscle. In this randomized, double-blinded, placebo-controlled study, we investigated the effects of six-month testosterone replacement therapy (TRT) and strength training (ST) on mitochondrial, glycogen, and lipid droplet (LD) content in skeletal muscle of aging men with subnormal bioavailable testosterone (BioT) levels. Mitochondrial, glycogen, and LD volume fractions in muscle biopsies were estimated by transmission electron microscopy. Insulin sensitivity (insulin-stimulated Rd) and body composition were assessed by euglycemic-hyperinsulinemic clamp and dual X-ray absorptiometry, respectively. TRT significantly increased total testosterone levels, BioT, and lean body mass (LBM) (p < 0.05), whereas percent body fat decreased (p < 0.05), and insulin sensitivity was unchanged. Baseline mitochondrial volume fraction correlated inversely with percent body fat (ρ = -0.43; p = 0.003). Δ-mitochondrial fraction correlated positively with Δ-total testosterone (ρ = 0.70; p = 0.02), and Δ-glycogen fraction correlated inversely with Δ-LBM (ρ = -0.83; p = 0.002) during six-month TRT, but no significant changes were observed in mitochondrial, glycogen, and LD volume fractions during TRT and ST. In conclusion, in this exploratory small-scale study, the beneficial effects of six-month TRT on total testosterone, LBM, and percent body fat were not followed by significant changes in fractions of mitochondria, glycogen, or lipid in skeletal muscle of aging men with lowered testosterone levels. Six-month ST or combined three-month ST+TRT did not change intramyocellular mitochondria, glycogen, and LD fractions compared to placebo. However, further studies with a larger sample size are needed.