Alternate Day Fasting Improves Physiological and Molecular Markers of Aging in Healthy, Non-obese Humans

Caloric restriction and intermittent fasting are known to prolong life- and healthspan in model organisms, while their effects on humans are less well studied. In a randomized controlled trial study (ClinicalTrials.gov identifier: NCT02673515), we show that 4 weeks of strict alternate day fasting (ADF) improved markers of general health in healthy, middle-aged humans while causing a 37% calorie reduction on average. No adverse effects occurred even after >6 months. ADF improved cardiovascular markers, reduced fat mass (particularly the trunk fat), improving the fat-to-lean ratio, and increased β-hydroxybutyrate, even on non-fasting days. On fasting days, the pro-aging amino-acid methionine, among others, was periodically depleted, while polyunsaturated fatty acids were elevated. We found reduced levels sICAM-1 (an age-associated inflammatory marker), low-density lipoprotein, and the metabolic regulator triiodothyronine after long-term ADF. These results shed light on the physiological impact of ADF and supports its safety. ADF could eventually become a clinically relevant intervention.

Sequential megafaunal collapse in the North Pacific Ocean: an ongoing legacy of industrial whaling?

Populations of seals, sea lions, and sea otters have sequentially collapsed over large areas of the northern North Pacific Ocean and southern Bering Sea during the last several decades. A bottom-up nutritional limitation mechanism induced by physical oceanographic change or competition with fisheries was long thought to be largely responsible for these declines. The current weight of evidence is more consistent with top-down forcing. Increased predation by killer whales probably drove the sea otter collapse and may have been responsible for the earlier pinniped declines as well. We propose that decimation of the great whales by post-World War II industrial whaling caused the great whales' foremost natural predators, killer whales, to begin feeding more intensively on the smaller marine mammals, thus "fishing-down" this element of the marine food web. The timing of these events, information on the abundance, diet, and foraging behavior of both predators and prey, and feasibility analyses based on demographic and energetic modeling are all consistent with this hypothesis.

Tracing carbon flow in an arctic marine food web using fatty acid-stable isotope analysis

Global warming and the loss of sea ice threaten to alter patterns of productivity in arctic marine ecosystems because of a likely decline in primary productivity by sea ice algae. Estimates of the contribution of ice algae to total primary production range widely, from just 3 to >50%, and the importance of ice algae to higher trophic levels remains unknown. To help answer this question, we investigated a novel approach to food web studies by combining the two established methods of stable isotope analysis and fatty acid (FA) analysis--we determined the C isotopic composition of individual diatom FA and traced these biomarkers in consumers. Samples were collected near Barrow, Alaska and included ice algae, pelagic phytoplankton, zooplankton, fish, seabirds, pinnipeds and cetaceans. Ice algae and pelagic phytoplankton had distinctive overall FA signatures and clear differences in delta(13)C for two specific diatom FA biomarkers: 16:4n-1 (-24.0+/-2.4 and -30.7+/-0.8 per thousand, respectively) and 20:5n-3 (-18.3+/-2.0 and -26.9+/-0.7 per thousand, respectively). Nearly all delta(13)C values of these two FA in consumers fell between the two stable isotopic end members. A mass balance equation indicated that FA material derived from ice algae, compared to pelagic diatoms, averaged 71% (44-107%) in consumers based on delta(13)C values of 16:4n-1, but only 24% (0-61%) based on 20:5n-3. Our estimates derived from 16:4n-1, which is produced only by diatoms, probably best represented the contribution of ice algae relative to pelagic diatoms. However, many types of algae produce 20:5n-3, so the lower value derived from it likely represented a more realistic estimate of the proportion of ice algae material relative to all other types of phytoplankton. These preliminary results demonstrate the potential value of compound-specific isotope analysis of marine lipids to trace C flow through marine food webs and provide a foundation for future work.

Optimization of a synthetic arginine receptor. Systematic tuning of noncovalent interactions

The simple arginine binder 1 could be optimized by strengthening pi-cation as well as electrostatic interactions. Electron-donating or -withdrawing substituents in the 5-position provide experimental evidence for pi-cation interactions, because binding energies increase by up to 0.6 kcal/mol due to a single benzene-guanidinium interaction. Even more effective is the introduction of a third phosphonate functionality at the correct distance, so that the guanidinium cation is recognized by optimal electrostatic and hydrogen bond interactions. Monte Carlo simulations and NOESY experiments confirm the expected complex geometries. The optimized host molecule 8 binds arginine half an order of magnitude more efficiently than the parent molecule.

Induction of apoptosis in human cancer cells by targeting mitochondria with gold nanoparticles

A major challenge in designing cancer therapies is the induction of cancer cell apoptosis, although activation of intrinsic apoptotic pathways by targeting gold nanoparticles to mitochondria is promising. We report an in vitro procedure targeting mitochondria with conjugated gold nanoparticles and investigating effects on apoptosis induction in the human breast cancer cell line Jimt-1. Gold nanoparticles were conjugated to a variant of turbo green fluorescent protein (mitoTGFP) harbouring an amino-terminal mitochondrial localization signal. Au nanoparticle conjugates were further complexed with cationic maltotriose-modified poly(propylene imine) third generation dendrimers. Fluorescence and transmission electron microscopy revealed that Au nanoparticle conjugates were directed to mitochondria upon transfection, causing partial rupture of the outer mitochondrial membrane, triggering cell death. The ability to target Au nanoparticles into mitochondria of breast cancer cells and induce apoptosis reveals an alternative application of Au nanoparticles in photothermal therapy of cancer.

Executive control functions in task switching: evidence from brain injured patients

Executive mechanisms involved in task switching were studied in 18 brain injured patients. The patients had to rapidly switch back and forth between two visual classification tasks and the analyses focused on switch costs, (i.e., performance differences between switch and no-switch trials), and on interference effects, (i.e., processing costs imposed by the presence of interfering stimulus attributes). The patients were grouped according to the side of the brain lesion. Patients with left brain damage (LBD) showed higher switch costs than patients with right brain damage (RBD). These group differences were attributable to disproportionally high switch costs in patients with LBD and language or speech disorders. This result suggests that the efficiency of suppressing internal interference from a recently activated task set depends on the availability of verbal representations of the upcoming task. Patients with RBD showed higher interference from external task sets. This effect was not affected by language or speech disorders. The overall results argue for a fractionation of executive functions to protect against interference from internal and external sources in task switching.

A novel preventive therapy for paclitaxel-induced cognitive deficits: preclinical evidence from C57BL/6 mice

Chemotherapy-induced central nervous system (CNS) neurotoxicity presents an unmet medical need. Patients often report a cognitive decline in temporal correlation to chemotherapy, particularly for hippocampus-dependent verbal and visuo-spatial abilities. We treated adult C57Bl/6 mice with 12 × 20 mg kg^-1 paclitaxel (PTX), mimicking clinical conditions of dose-dense chemotherapy, followed by a pulse of bromodesoxyuridine (BrdU) to label dividing cells. In this model, mice developed visuo-spatial memory impairments, and we measured peak PTX concentrations in the hippocampus of 230 nm l^-1, which was sevenfold higher compared with the neocortex. Histologic analysis revealed a reduced hippocampal cell proliferation. In vitro, we observed severe toxicity in slowly proliferating neural stem cells (NSC) as well as human neuronal progenitor cells after 2 h exposure to low nanomolar concentrations of PTX. In comparison, mature post-mitotic hippocampal neurons and cell lines of malignant cells were less vulnerable. In PTX-treated NSC, we observed an increase of intracellular calcium levels, as well as an increased activity of calpain- and caspase 3/7, suggesting a calcium-dependent mechanism. This cell death pathway could be specifically inhibited with lithium, but not glycogen synthase kinase 3 inhibitors, which protected NSC in vitro. In vivo, preemptive treatment of mice with lithium prevented PTX-induced memory deficits and abnormal adult hippocampal neurogenesis. In summary, we identified a molecular pathomechanism, which invokes PTX-induced cytotoxicity in NSC independent of cell cycle status. This pathway could be pharmacologically inhibited with lithium without impairing paclitaxel's tubulin-dependent cytostatic mode of action, enabling a potential translational clinical approach.

Barriers to participation in clinical trials: a physician survey

Background

Clinical trials are vital for evidence-based cancer care. Oncologist engagement in clinical trials has an effect on patient recruitment, which in turn can affect trial success. Identifying barriers to clinical trial participation might enable interventions that could help to increase physician participation.

Methods

To assess factors affecting physician engagement in oncology trials, a national survey was conducted using the online SurveyMonkey tool (SurveyMonkey, San Mateo, CA, U.S.A.; http://www.surveymonkey.com). Physicians associated with the Canadian Cancer Clinical Trials Network and the Canadian Cancer Trials Group were asked about their specialty, years of experience, barriers to participation, and motivating interventions, which included an open-ended question inviting survey takers to suggest interventions.

Results

The survey collected 207 anonymous responses. Respondents were predominantly medical oncologists (46.4%), followed by radiation oncologists (24.6%). Almost 70% of the respondents had more than 10 years of experience. Significant time constraints included extra paperwork (77%), patient education (54%), and extended follow-up or clinic visits (53%). Timing of events within trials was also a barrier to participation (55%). Most respondents favoured clinical work credits (72%), academic credits (67%), a clinical trial alert system (75%), a regular meeting to review trial protocols (65%), and a screening log to aid in patient accrual (67%) as motivational strategies. Suggested interventions included increased support staff, streamlined regulatory burden, and provision of greater funding for trials and easier access to ancillary services.

Conclusions

The present study confirms that Canadian oncologists are willing to participate in clinical research, but face multiple barriers to trial participation. Those barriers could be mitigated by the implementation of several interventions identified in the study.

Reduced B12 uptake and increased gastrointestinal formate are associated with archaeome-mediated breath methane emission in humans

BACKGROUND

Methane is an end product of microbial fermentation in the human gastrointestinal tract. This gas is solely produced by an archaeal subpopulation of the human microbiome. Increased methane production has been associated with abdominal pain, bloating, constipation, IBD, CRC or other conditions. Twenty percent of the (healthy) Western populations innately exhale substantially higher amounts (>5 ppm) of this gas. The underlying principle for differential methane emission and its effect on human health is not sufficiently understood.

RESULTS

We assessed the breath methane content, the gastrointestinal microbiome, its function and metabolome, and dietary intake of one-hundred healthy young adults (female: n = 52, male: n = 48; mean age =24.1). On the basis of the amount of methane emitted, participants were grouped into high methane emitters (CH4 breath content 5-75 ppm) and low emitters (CH4 < 5 ppm). The microbiomes of high methane emitters were characterized by a 1000-fold increase in Methanobrevibacter smithii. This archaeon co-occurred with a bacterial community specialized on dietary fibre degradation, which included members of Ruminococcaceae and Christensenellaceae. As confirmed by metagenomics and metabolomics, the biology of high methane producers was further characterized by increased formate and acetate levels in the gut. These metabolites were strongly correlated with dietary habits, such as vitamin, fat and fibre intake, and microbiome function, altogether driving archaeal methanogenesis.

CONCLUSIONS

This study enlightens the complex, multi-level interplay of host diet, genetics and microbiome composition/function leading to two fundamentally different gastrointestinal phenotypes and identifies novel points of therapeutic action in methane-associated disorders. Video Abstract.

Liver resection or cryotherapy for colorectal liver metastases: a prospective case control study

BACKGROUND AND AIMS

While there is promising survival data for cryosurgery of colorectal liver metastases, local recurrence following cryoablation remains a problem. We aimed to compare morbidity and mortality, as well as the recurrence pattern and survival after liver resection and cryotherapy (alone or in combination with resection) for liver metastases.

PATIENTS AND METHODS

Between 1996 and 2002, 168 patients underwent liver resection alone and 55 patients had cryotherapy (25 in combination with liver resection) for colorectal liver metastases. The patient, tumour and operative details were recorded prospectively and the two patient groups were compared regarding morbidity, survival and recurrence.

RESULTS

More patients had a prior liver resection, liver metastases were smaller and less frequently synchronous, morbidity was significantly lower and hepatic recurrence was significantly more frequent in the cryotherapy group. Five-year survival rates following resection and cryotherapy were comparable (23 and 26% respectively), while overall and hepatic recurrence-free survival was inferior following cryotherapy.

CONCLUSION

Cryotherapy is a valuable treatment option for some patients with non-resectable colorectal liver metastases. While survival is comparable to that after resection, higher hepatic recurrence rates following cryotherapy should caution against the use of cryotherapy for resectable disease until the results of randomized controlled trials are available.

Causes and consequences of marine mammal population declines in southwest Alaska: a food-web perspective

Populations of sea otters, seals and sea lions have collapsed across much of southwest Alaska over the past several decades. The sea otter decline set off a trophic cascade in which the coastal marine ecosystem underwent a phase shift from kelp forests to deforested sea urchin barrens. This interaction in turn affected the distribution, abundance and productivity of numerous other species. Ecological consequences of the pinniped declines are largely unknown. Increased predation by transient (marine mammal-eating) killer whales probably caused the sea otter declines and may have caused the pinniped declines as well. Springer et al. proposed that killer whales, which purportedly fed extensively on great whales, expanded their diets to include a higher percentage of sea otters and pinnipeds following a sharp reduction in great whale numbers from post World War II industrial whaling. Critics of this hypothesis claim that great whales are not now and probably never were an important nutritional resource for killer whales. We used demographic/energetic analyses to evaluate whether or not a predator-prey system involving killer whales and the smaller marine mammals would be sustainable without some nutritional contribution from the great whales. Our results indicate that while such a system is possible, it could only exist under a narrow range of extreme conditions and is therefore highly unlikely.

Laparoscopic appendectomy in children with Enterobius vermicularis

As surgeons gain more experience with laparoscopy in children, it is becoming apparent that one of the best applications of the technique is for appendicitis. The advantages of laparoscopic appendectomy include a better cosmetic result, particularly in young female patients, a shorter recovery time, and an early return to normal activities. In the differential diagnosis of appendicitis, the association of Enterobius vermicularis (pinworms) inflammation in the pediatric age group is not uncommon. The endo-loop technique for laparoscopic appendectomy is the standard technique used in our department. In three patients with E. vermicularis undergoing appendix removal using this technique, pinworms were found to be set free into the abdomen after dividing the appendix between the loop ligatures. Bipolar coagulating forceps were used carefully to thermally desiccate the worms, which were then removed using a blunt grasper. E. vermicularis being released into the abdomen in children undergoing laparoscopic appendectomy using the endo-loop technique has not been reported. Careful evaluation of the appendix stump and simple but careful thermal desiccation and removal of pinworms, if present, must be considered when using the endo-loop technique.

Combined pentalogy of Cantrell with tetralogy of Fallot, gallbladder agenesis, and polysplenia: a case report

A male newborn with pentalogy of Cantrell, tetralogy of Fallot, agenesis of the gallbladder, and polysplenia died at 3 days of age. Polysplenia was not previously reported in this association.

Habitat use and habitat selection by spotted seals (Phoca largha) in the Bering Sea

Twelve spotted seals (Phoca largha) equipped with satellite-linked tags were tracked in the Bering Sea for 46-272 days during August-June 1991-1994. Alaskan seals were mostly near shore during August-October and 100-200 km offshore in January-June, and were broadly distributed in the region north of the 200-m isobath. Russian seals were located primarily near shore and within 100 km of the 200-m isobath during all months. During August-October, all seals were usually more than 200 km south of the sea-ice edge. In January-June, seals were mostly 0-200 km north of the sea-ice edge, often in areas with extensive ice coverage (7/10-9/10). We tested for habitat selection by determining how frequently a randomly moving seal would have been located in each habitat and comparing that with observed habitat use. Russian seals selected for nearshore and shallow-water areas in September-October and for near shore, within 25 km of the 200-m isobath, and the ice front during November-April. Alaskan seals selected for near shore areas in September-December; for offshore, shallow water, and the ice front in January-February; and for shallow water and pack ice in March-April. Biological processes associated with the highly productive "Green Belt" may have influenced the habitat use of Russian seals, but this did not appear to have been the case with Alaskan seals.

Rising rates of hospital-onset Klebsiella spp. and Pseudomonas aeruginosa bacteraemia in NHS acute trusts in England: a review of national surveillance data, August 2020-February 2021

Increases in hospital-onset Klebsiella spp. and Pseudomonas aeruginosa bacteraemia rates in England were observed between August 2020 and February 2021 to the highest levels recorded since the start of mandatory surveillance in April 2017. Cases were extracted from England's mandatory surveillance database for key Gram-negative bloodstream infections. Incidence rates for hospital-onset bacteraemia cases increased from 8.9 (N=255) to 14.9 (N=394) per 100,000 bed-days for Klebsiella spp. [incidence rate ratio (IRR) 1.7, P<0.001], and from 4.9 (N=139) to 6.2 (N=164) per 100,000 bed-days for P. aeruginosa (IRR 1.3, P<0.001) (August 2020-February 2021). These incidence rates were higher than the average rates observed during the same period in the previous 3 years. These trends coincided with an increase in the percentage of hospital-onset bacteraemia cases that were also positive for severe acute respiratory syndrome coronavirus-2.

Delayed referral despite appropriate knowledge in cryptorchidism as a cause of delayed orchidopexies in Austria

AIM

Guidelines recommend early orchidopexy in cryptorchidism to decrease the risk of infertility and tumor formation. We aimed to asses if a delayed initial presentation for cryptorchidism was due to unawareness of these guidelines or for any other reasons.

METHODS

A short questionnaire exploring timing and referral habits when assessing children with cryptorchidism was sent by email to all registered pediatricians in Austria. Comparatively, a chart review of performed orchidopexies was performed at our institution.

RESULTS

Of 369 registered pediatricians, 102 (27.6%) returned valid questionnaires. The average maximum age at which pediatricians in Austria suggested treatment of cryptorchidism was the 21.2 (8.4 months standard deviation (SD)) month of life. Assessment of testicular descent was reported to be regularly performed until the 8.8 (3-18 years SD) year of life. In contrast, from 1997-2008, 730 boys were treated surgically for cryptorchidism at our department. The mean age at operation was 3.4 years (3.1 years SD).

CONCLUSION

The majority of pediatricians in Austria know the correct timing for treatment of cryptorchidism. Nevertheless, orchidopexies are still carried out to later than suggested by international guidelines. Further studies and analysis to evaluate the reasons for these suboptimal referring patterns coupled with further communication improvements between pediatricians and surgeons are needed.

Distribution of Borrelia burgdorferi s.l. and Borrelia miyamotoi in Ixodes tick populations in Northern Germany, co-infections with Rickettsiales and assessment of potential influencing factors

To determine Borrelia spp. (Spirochaetales: Spirochaetaceae) prevalence and species distribution in Northern Germany, Ixodes ticks were sampled from April to October in 2018 and 2019 by the flagging method at three locations each in five regions. Analysis by quantitative real-time PCR of 3150 individual ticks revealed an overall prevalence of 30.6%, without significant differences between tick stages (31.7% positive adults, 28.6% positive nymphs). Significant differences were observed in seasonal infection rates, but not between regions, landscape types or sampling years. Analysis of co-infections with Rickettsiales indicated a negative association between Borrelia and Anaplasma phagocytophilum infection. The most frequent Borrelia species differentiated by Reverse Line Blot were B. afzelii and B. garinii/B. bavariensis, followed by B. valaisiana, B. burgdorferi sensu stricto, B. spielmanii and B. lusitaniae. Furthermore, B. miyamotoi was identified in 12.9% of differentiable samples. No effect of region nor landscape type on species composition was found, but significant variations in the distribution at the different sampling sites within a region were observed. The detected monthly fluctuations in prevalence and the differences in intra-regional Borrelia species distribution underline the importance of long-term and multi-location monitoring of Borrelia spp. in ticks as an essential part of public health assessment.

Potassium ions promote hexokinase-II dependent glycolysis

High expression levels of mitochondria-associated hexokinase-II (HKII) represent a hallmark of metabolically highly active cells such as fast proliferating cancer cells. Typically, the enzyme provides a crucial metabolic switch towards aerobic glycolysis. By imaging metabolic activities on the single-cell level with genetically encoded fluorescent biosensors, we here demonstrate that HKII activity requires intracellular K+. The K+ dependency of glycolysis in cells expressing HKII was confirmed in cell populations using extracellular flux analysis and nuclear magnetic resonance-based metabolomics. Reductions of intracellular K+ by gramicidin acutely disrupted HKII-dependent glycolysis and triggered energy stress pathways, while K+ re-addition promptly restored glycolysis-dependent adenosine-5'-triphosphate generation. Moreover, expression and activation of KV1.3, a voltage-gated K+ channel, lowered cellular K+ content and the glycolytic activity of HEK293 cells. Our findings unveil K+ as an essential cofactor of HKII and provide a mechanistic link between activities of distinct K+ channels and cell metabolism.

Exercise radionuclide ventriculography in evaluating successful transluminal coronary angioplasty

To evaluate the ability of transluminal coronary angioplasty (TCA) to relieve myocardial ischemia, 44 patients with single vessel disease underwent exercise gated radionuclide ventriculography (GRNV) before and 2.8 +/- 1.3 days following angiographically successful TCA. Pre-TCA GRNV was abnormal in 11 of 14 patients with right coronary artery (RCA) stenosis and 24 of 30 with left anterior descending (LAD) stenosis. Following TCA there was an increase in exercise duration from 500 +/- 288 sec to 625 +/- 273 sec (P less than 0.001), and in maximum double product from (209 +/- 69) x 10(2) to (263 +/- 70) x 10(2) (P less than 0.001). The number of patients with stress-induced ST-T abnormalities decreased from 13 to 4 (P less than 0.05), and the number with chest pain during exercise decreased from 18 to one (P less than 0.001). Whereas resting ejection fraction was unchanged (0.58 +/- 0.10 vs 0.59 +/- 0.11) following TCA, the ejection fraction at peak exercise increased from 0.61 +/- 0.13 to 0.66 +/- 0.12 (P less than 0.001). Of 24 patients with resting abnormalities, regional wall motion improved in 13. In 22 of 31 patients with stress-induced asynergy, the wall motion response to exercise improved (P less than 0.001). Of 19 patients restudied angiographically and with exercise GRNV at 6-12 months, restenosis of greater than or equal to 50% had occurred in six, four of whom had abnormal studies. In six of whom the degree of stenosis of the dilated artery had remained less than or equal to 20% the exercise GRNV study remained normal. It is concluded that GRNV is helpful in documenting the improvement in resting left ventricular function and functional reserve in patients with angiographically successful TCA. In the limited number of patients with late follow-up studies, data suggest that GRNV may be a valuable test to detect restenosis.

[Standards for treatment and expert opinion on transsexuals. The German Society for Sexual Research, The Academy of Sexual medicine and the Society for Sexual Science]

Over the last two-and-a-half years a committee of experts, consisting of members of the three leading German sexology associations, developed guidelines for treating and assessing transsexuals. Their purpose is to improve the care for patients with sex identity disorders and to ensure that such care is of uniform quality to avoid erroneous decisions to the disadvantage of those affected. The guidelines are set out in full.

T-lymphocyte subpopulations in the peripheral blood of patients with Crohn's disease

Samples of peripheral blood from 26 patients with Crohn's disease (CD) and 26 healthy age- and sex-matched controls were tested simultaneously for B and T lymphocytes and T-lymphocyte subpopulations with receptors for IgM (TM) and IgG (TG). Patients with CD had reduced proportions of T lymphocytes, and this reduction showed a significant correlation to the CD activity index (r = -0.65, p less than 0.01). There was slight reduction of TM only (p less than 0.05) inpatients with highly active disease but not in the total population of patients studied. Proportions of B and TG cells were similar in patients and controls. Patients with no clinical or radiological but histological signs of active disease had T lymphocytes and subpopulations like patients with inactive disease. This suggests that the reduction of T cells and T-cell subpopulations in CD are secondary effects. With regard to T-lymphocyte subpopulations, our results are in contrast to a recently published report and do not suggest that analysis of T cells according to the expression of Fc receptors helps in the understanding of functional changes in the T-cell system in patients with CD.