Persistent influence of precession on northern ice sheet variability since the early Pleistocene

Prior to ~1 million years ago (Ma), variations in global ice volume were dominated by changes in obliquity; however, the role of precession remains unresolved. Using a record of North Atlantic ice rafting spanning the past 1.7 million years, we find that the onset of ice rafting within a given glacial cycle (reflecting ice sheet expansion) consistently occurred during times of decreasing obliquity whereas mass ice wasting (ablation) events were consistently tied to minima in precession. Furthermore, our results suggest that the ubiquitous association between precession-driven mass wasting events and glacial termination is a distinct feature of the mid to late Pleistocene. Before then (increasing), obliquity alone was sufficient to end a glacial cycle, before losing its dominant grip on deglaciation with the southward extension of Northern Hemisphere ice sheets since ~1 Ma.

P5750Manipulation strategy for crossing coronary chronic total occlusion: an update from the Japanese CTO-PCI expert registry

Background

The percutaneous coronary intervention (PCI) strategy for chronic total occlusion (CTO) based on the guidewire manipulation time remains infrequent.

Purpose

We aimed to assess CTO-PCI strategy on the basis of guidewire manipulation time.

Methods

A total of 5843 patients undergoing CTO PCI between January 2014 and December 2017 and enrolled in the Japanese CTO-PCI expert registry were assessed. Their CTO-PCI strategies, procedural outcomes, and guidewire manipulation time were analysed.

Results

The primary retrograde approach was performed on 1562 patients (26.7%). The overall guidewire and technical success rates were 92.8% and 90.6%, respectively. Median guidewire manipulation time of guidewire success and failure were 56 (interquatile range [IQR]: 22 to 111) min and 176 (IQR: 130 to 229) min, respectively. The average Japanese CTO score of the primary antegrade approach with the antegrade alone, the primary antegrade approach with the retrograde approach, and the primary retrograde approach were 1.7±1.1, 2.1±1.2, and 2.3±1.1, respectively (p<0.001). Median successful guidewire crossing time of single wiring in the antegrade alone was 23 (IQR: 11 to 44) min, and that of the primary retrograde approach was significantly shorter than that of the primary antegrade approach with the retrograde approach (107 [IQR: 70 to 161] min vs. 126 [IQR: 87 to 174] min; p<0.001). Reattempt, CTO length ≥20 mm, and proximal cap ambiguity were the predictors of guidewire failure in the primary antegrade approach with antegrade alone, but were not those in the primary retrograde approach.

Conclusions

Although successful guidewire crossing time of the primary antegrade approach with the antegrade alone is short, that of the primary retrograde approach can be shorter than that of the primary antegrade approach with the retrograde approach. Choosing an appropriate CTO-PCI strategy leads to shortening of successful guidewire crossing time.

Fission yeast APC/C activators Slp1 and Fzr1 sequentially trigger two consecutive nuclear divisions during meiosis

In meiosis, two rounds of nuclear division occur consecutively without DNA replication between the divisions. We isolated a fission yeast mutant in which the nucleus divides only once to generate two spores, as opposed to four, in meiosis. In this mutant, we found that the initiation codon of the slp1⁺ gene is converted to ATA, producing a reduced amount of Slp1. As a member of the Fizzy family of anaphase-promoting complex/cyclosome (APC/C) activators, Slp1 is essential for vegetative growth; however, the mutant allele shows a phenotype only in meiosis. Slp1 insufficiency delays degradation of maturation-promoting factor at the first meiotic division, and another APC/C activator, Fzr1, which acts late in meiosis, terminates meiosis immediately after the delayed first division to produce two viable spores.

Nanocoating for biomolecule delivery using layer-by-layer self-assembly

Since its introduction in the early 1990s, layer-by-layer (LbL) self-assembly of films has been widely used in the fields of nanoelectronics, optics, sensors, surface coatings, and controlled drug delivery. The growth of this industry is propelled by the ease of film manufacture, low cost, mild assembly conditions, precise control of coating thickness, and versatility of coating materials. Despite the wealth of research on LbL for biomolecule delivery, clinical translation has been limited and slow. This review provides an overview of methods and mechanisms of loading biomolecules within LbL films and achieving controlled release. In particular, this review highlights recent advances in the development of LbL coatings for the delivery of different types of biomolecules including proteins, polypeptides, DNA, particles and viruses. To address the need for co-delivery of multiple types of biomolecules at different timing, we also review recent advances in incorporating compartmentalization into LbL assembly. Existing obstacles to clinical translation of LbL technologies and enabling technologies for future directions are also discussed.

Does Regular Post-exercise Cold Application Attenuate Trained Muscle Adaptation?

This study examined the effects of regular post-exercise cold application on muscular and vascular adaptations induced by moderate-intensity resistance training. 14 male subjects participated in resistance training: 5 sets of 8 wrist-flexion exercises at workload of 70-80% of the single repetition maximum, 3 times a week for 6 weeks. 7 subjects immersed their experimental forearms in cold water (10±1°C) for 20 min after wrist-flexion exercises (cooled group), and the other 7 served as control subjects (noncooled group). Measurements were taken before and after the training period; wrist-flexor thickness, brachial-artery diameter, maximal muscle strength, and local muscle endurance were measured in upper extremities. Wrist-flexor thicknesses of the experimental arms increased after training in both groups, but the extent of each increase was significantly less in the cooled group compared with the noncooled group. Maximal muscle strength and brachial-artery diameter did not increase in the cooled group, while they increased in the noncooled group. Local muscle endurance increased in both groups, but the increase in the cooled group tended to be lower compared to the noncooled group. Regular post-exercise cold application to muscles might attenuate muscular and vascular adaptations to resistance training.

Tofogliflozin, a sodium/glucose cotransporter 2 inhibitor, attenuates body weight gain and fat accumulation in diabetic and obese animal models

OBJECTIVE

Tofogliflozin, a highly selective inhibitor of sodium/glucose cotransporter 2 (SGLT2), induces urinary glucose excretion (UGE), improves hyperglycemia and reduces body weight in patients with Type 2 diabetes (T2D). The mechanisms of tofogliflozin on body weight reduction were investigated in detail with obese and diabetic animal models.

METHODS

Diet-induced obese (DIO) rats and KKAy mice (a mouse model of diabetes with obesity) were fed diets containing tofogliflozin. Body weight, body composition, biochemical parameters and metabolic parameters were evaluated.

RESULTS

In DIO rats tofogliflozin was administered for 9 weeks, UGE was induced and body weight gain was attenuated. Body fat mass decreased without significant change in bone mass or lean body mass. Food consumption (FC) increased without change in energy expenditure, and deduced total calorie balance (deduced total calorie balance=FC-UGE-energy expenditure) decreased. Respiratory quotient (RQ) and plasma triglyceride (TG) level decreased, and plasma total ketone body (TKB) level increased. Moreover, plasma leptin level, adipocyte cell size and proportion of CD68-positive cells in mesenteric adipose tissue decreased. In KKAy mice, tofogliflozin was administered for 3 or 5 weeks, plasma glucose level and body weight gain decreased together with a reduction in liver weight and TG content without a reduction in body water content. Combination therapy with tofogliflozin and pioglitazone suppressed pioglitazone-induced body weight gain and reduced glycated hemoglobin level more effectively than monotherapy with either pioglitazone or tofogliflozin alone.

CONCLUSION

Body weight reduction with tofogliflozin is mainly due to calorie loss with increased UGE. In addition, tofogliflozin also induces a metabolic shift from carbohydrate oxidation to fatty acid oxidation, which may lead to prevention of fat accumulation and inflammation in adipose tissue and liver. Tofogliflozin may have the potential to prevent obesity, hepatic steatosis and improve insulin resistance as well as hyperglycemia.

Chromosomes rein back the spindle pole body during horsetail movement in fission yeast meiosis

In meiosis, pairing and recombination of homologous chromosomes are crucial for the correct segregation of chromosomes, and substantial movements of chromosomes are required to achieve homolog pairing. During this process, it is known that telomeres cluster to form a bouquet arrangement of chromosomes. The fission yeast Schizosaccharomyces pombe provides a striking example of bouquet formation, after which the entire nucleus oscillates between the cell poles (these oscillations are generally called horsetail nuclear movements) while the telomeres remain clustered to the spindle pole body (SPB; a centrosome-equivalent structure in fungi) at the leading edge of the moving nucleus. S. pombe mutants defective in telomere clustering frequently form aberrant spindles, such as monopolar or nonpolar spindles, leading to missegregation of the chromosomes at the subsequent meiotic divisions. Here we demonstrate that such defects in meiotic spindle formation caused by loss of meiotic telomere clustering are rescued when nuclear movement is prevented. On the other hand, stopping nuclear movement does not rescue defects in telomere clustering, nor chromosome missgregation even in cells that have formed a bipolar spindle. These results suggest that movement of the SPB without attachment of telomeres leads to the formation of aberrant spindles, but that recovering bipolar spindles is not sufficient for rescue of chromosome missegregation in mutants lacking telomere clustering.

Relationship between xerostomia and gingival condition in young adults

BACKGROUND AND OBJECTIVE

Xerostomia is a subjective symptom of dryness in the mouth. Although a correlation between xerostomia and oral conditions in the elderly has been reported, there are few such studies in the young adults. The aim of this study was to examine the relationship of xerostomia with the gingival condition in university students.

MATERIAL AND METHODS

A total of 2077 students (1202 male subjects and 875 female subjects), 18-24 years of age, were examined. The disease activity and severity of the gingival condition were assessed as the percentage of teeth with bleeding on probing (%BOP) and the presence of teeth with probing pocket depth of ≥ 4 mm, respectively. Additional information on xerostomia, oral health behaviors, coffee/tea intake and nasal congestion was collected via a questionnaire. Path analysis was used to test pathways from xerostomia to the gingival condition.

RESULTS

One-hundred and eighty-three (8.8%) students responded that their mouths frequently or always felt dry. Xerostomia was related to %BOP and dental plaque formation, but was not related to the presence of probing pocket depth ≥ 4 mm. In the structural model, xerostomia was related to dental plaque formation (p < 0.01), and a lower level of dental plaque formation was associated with a lower %BOP. Xerostomia was associated with coffee/tea intake (p < 0.01) and nasal congestion (p < 0.001).

CONCLUSION

Xerostomia was indirectly related to gingival disease activity through the accumulation of dental plaque. Nasal congestion and coffee/tea intake also affected xerostomia. These findings suggest that xerostomia should be considered in screening for gingivitis risk in young adults.