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- Intrinsic circannual regulation of brown adipose tissue form and function in tune with hibernation. [JOURNAL ARTICLE]
- Am J Physiol Endocrinol Metab 2013 Dec 10.
Winter hibernators repeatedly cycle between cold-torpor and rewarming supported by non-shivering thermogenesis in brown adipose tissue (BAT). In contrast, summer animals are homeotherms, undergoing reproduction, growth and fattening. This life history confers variability to BAT recruitment and activity. To address the components underlying pre-winter enhancement and winter activation, we interrogated the BAT proteome in 13-lined ground squirrels among three summer and five winter states. We also examined mixed physiology fall and spring individuals to test for ambient temperature and seasonal effects, and the timing of seasonal transitions. BAT form and function differs circannually in these animals, as evidenced by morphology and proteome dynamics. This intrinsic pattern distinguished homeothermic groups and early vs. late winter hibernators. Homeothermic variation derived from post-emergence delay in growth and substrate biosynthesis. The heterothermic proteome varied less despite extreme winter physiological shifts and was optimized to exploit lipids by enhanced fatty acid binding, β-oxidation and mitochondrial protein translocation. Surprisingly, ambient temperature did not affect the BAT proteome during transition seasons; rather the pronounced summer-winter shift preceded environmental changes and phenotypic progression. During fall transition, differential regulation of two fatty acid binding proteins provides further evidence of recruitment and separates proteomic preparation from successful hibernation. Abundance of FABP4 correlates with torpor bout length throughout the year, clarifying its potential function in hibernation. Metabolically active BAT is a target for treating human obesity and metabolic disorders. Understanding the hibernator's extreme and seasonally distinct recruitment and activation control strategies offers untapped potential to identify novel, therapeutically relevant regulatory pathways.
- Implications of the lack of desiccation tolerance in recalcitrant seeds. [REVIEW]
- Front Plant Sci 2013.:478.
A suite of interacting processes and mechanisms enables tolerance of desiccation and storage (conservation) of orthodox seeds in the dry state. While this is a long-term option under optimized conditions, dry orthodox seeds are not immortal, with life spans having been characterized as short, intermediate and long. Factors facilitating desiccation tolerance are metabolic "switch-off" and intracellular dedifferentiation. Recalcitrant seeds lack these mechanisms, contributing significantly to their desiccation sensitivity. Consequently, recalcitrant seeds, which are shed at high water contents, can be stored only in the short-term, under conditions not allowing dehydration. The periods of such hydrated storage are constrained by germination that occurs without the need for extraneous water, and the proliferation of seed-associated fungi. Cryopreservation is viewed as the only option for long-term conservation of the germplasm of recalcitrant-seeded species. This is not easily achieved, as each of the necessary procedures imposes oxidative damage. Intact recalcitrant seeds cannot be cryopreserved, the common practice being to use excised embryos or embryonic axes as explants. Dehydration is a necessary procedure prior to exposure to cryogenic temperatures, but this is associated with metabolism-linked injury mediated by uncontrolled reactive oxygen species generation and failing anti-oxidant systems. While the extent to which this occurs can be curtailed by maximizing drying rate (flash drying) it cannot be completely obviated. Explant cooling for, and rewarming after, cryostorage must necessarily be rapid, to avoid ice crystallization. The ramifications of desiccation sensitivity are discussed, as are problems involved in cryostorage, particularly those accompanying dehydration and damage consequent upon ice crystallization. While desiccation sensitivity is a "fact" of seed recalcitrance, resolutions of the difficulties involved germplasm conservation are possible as discussed.
- Chill-induced morphological alterations in Anacystis Nidulans as a function of growth temperature. [JOURNAL ARTICLE]
- Planta 1979 Jan; 145(1):63-68.
Cells of Anacystis nidulans grown at 25 or 30°C were examined both by thin-section and freeze-fracture electron microscopy. Cells grown at either temperature appeared similar when fixed at the growth temperature prior to observation. When cells were chilled to near 0°C for 30 min prior to fixation, those previously grown at 25° appeared unchanged as judged by thin sectioning while those grown at 39° showed considerable morphological alteration. Freeze fracture showed particle aggregation (more pronounced in 39°-grown cells) indicating lipid-phase separation in cells chilled prior to fixation. The phase separation was totally reversed by rewarming the chilled, 25°-grown cells to their growth temperature but was only partially reversed by rewarming chilled, 39°-grown cells. These results correlate with other effects of chilling seen in Anacystis cells grown at different temperatures.
- 49 practical application of the hollow fiber vitrification method for cryopreservation of Mammalian embryos. [Journal Article]
- Reprod Fertil Dev 2013 Dec; 26(1):138-9.
We recently developed the hollow fibro vitrification (HFV) method, which is a novel, high-performance embryo cryopreservation method (Matsunari et al., 2012). In this study, we aimed to verify the applicability of the HFV method for cryopreserving various types of embryos; BDF1 mouse embryos at the 2-cell stage, porcine parthenogenetic morulae derived from in vitro-matured oocytes, bovine morulae produced by in vitro maturation/fertilization (LIAJ Animal Biotechnology Center, Tokyo, Japan), and in vivo-derived blastocysts of common marmosets were vitrified, and their survival was assessed by culture or transfer. The embryos were vitrified using 20mM HEPES-buffered TCM-199 containing 20% calf serum as a base medium. Cellulose acetate hollow fibres (25mm) containing 1 to 20 embryos were placed in an equilibration solution containing 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (DMSO) for 5 to 7min, followed by incubation for 1min in vitrification solution containing 15% EG, 15% DMSO, and 0.5M sucrose. The embryos were then vitrified by immersion in LN. The embryos were devitrified by immersing the hollow fibre in a 1M sucrose solution at 38.5°C, which was followed by stepwise dilution of the cryoprotectants and washing. For a subset of the vitrified mouse embryos, rewarming in a non-ultra-rapid manner by melting a hollow fibre in air at room temperature for 5s was tested. Embryo transfer was performed to assess the viability of the vitrified mouse embryos. For porcine embryos, vitrification in LN vapor (-150°C) was tested. Development of the vitrified mouse embryos to blastocysts was equal to that of the non-vitrified embryos [105/110 (95.5%) v. 109/110 (99.1%)]. Post-transfer development to fetuses was also equal between the vitrified and non-vitrified embryos [pregnancy rates: 4/4 v. 2/2; developmental rates: 55/80 (68.8%) v. 35/40 (87.5%)]. Non-ultra-rapid rewarming did not decrease the survival of the vitrified mouse embryos [blastocysts: 94/100 (94.0%); pregnancy: 4/4; fetuses: 55/80 (68.8%)]. Blastocyst formation was equivalent for vitrification of porcine embryos in LN vapor [27/34 (79.4%)], direct immersion into LN [28/35 (80.0%)], and the non-vitrified control [31/32 (96.9%)]. Vitrification of 191 bovine morulae resulted in 153 (80.1%) blastocysts. In preliminary experiments, survival of marmoset blastocysts was 100% (n=6). These data demonstrate that the HFV method is (1) effective for embryos of various species and production methods; (2) effective even for porcine in vitro-derived morulae, which are highly cryosensitive; and (3) amenable to modifications such as non-ultra-rapid warming and cooling in LN vapor, increasing the potential applicability of the HFV method. For instance, vitrification in LN vapor may allow embryo cryopreservation with high hygienic standards.
- In Vivo Evaluation of Wound Bed Reaction and Graft Performance After Cold Skin Graft Storage: New Targets for Skin Tissue Engineering. [JOURNAL ARTICLE]
- J Burn Care Res 2013 Dec 3.
Surplus harvested skin grafts are routinely stored at 4 to 6°C in saline for several days in plastic surgery. The purpose of this study was to evaluate the influence of storage on human skin graft performance in an in vivo intravital microscopic setting after transplantation. Freshly harvested human full-thickness skin grafts and split-thickness skin grafts (STSGs) after storage of 0, 3, or 7 days in moist saline at 4 to 6°C were transplanted into the modified dorsal skinfold chamber, and intravital microscopy was performed to evaluate vessel morphology and angiogenic change of the wound bed. The chamber tissue was harvested 10 days after transplantation for evaluation of tissue integrity and inflammation (hematoxylin and eosin) as well as for immunohistochemistry (human CD31, murine CD31, Ki67, Tdt-mediated dUTP-biotin nick-end labelling). Intravital microscopy results showed no differences in the host angiogenic response between fresh and preserved grafts. However, STSGs and full-thickness skin grafts exhibited a trend toward different timing and strength in capillary widening and capillary bud formation. Preservation had no influence on graft quality before transplantation, but fresh STSGs showed better quality 10 days after transplantation than 7-day preserved grafts. Proliferation and apoptosis as well as host capillary in-growth and graft capillary degeneration were equal in all groups. These results indicate that cells may activate protective mechanisms under cold conditions, allowing them to maintain function and morphology. However, rewarming may disclose underlying tissue damage. These findings could be translated to a new approach for the design of full-thickness skin substitutes.
- Prolonged hypothermia due to olanzapine in the setting of renal failure: a case report and review of the literature. [REVIEW]
- Ther Adv Psychopharmacol 2013 Dec; 3(6):335-339.
Temperature dysregulation is an infrequent but previously documented adverse effect of antipsychotic medications. The majority of documented cases involve durations of hypothermia of less than 24 h. We present the case of a patient on therapeutic olanzapine for bipolar disease with dehydration from gastroenteritis leading to acute kidney injury in the setting of stage III chronic kidney disease, who presented with severe hypothermia of 31.2°C (88.2°F). He required active rewarming in the intensive care unit for a total of 9 days. This is the second case report of prolonged hypothermia from olanzapine in the setting of kidney disease. Clinicians should be aware that patients with renal dysfunction may be at increased risk for prolonged hypothermia from olanzapine.
- Disposition of Midazolam in Asphyxiated Neonates Receiving Therapeutic Hypothermia - A Pilot Study. [JOURNAL ARTICLE]
- Klin Padiatr 2013 Nov 28.
Moderate hypothermia has become an established therapy for asphyxiated neonates. Midazolam is a frequently used sedative for this indication, although it has never been investigated how therapeutic hypothermia and asphyxia influence midazolam metabolism in neonates.9 asphyxiated newborns were treated with whole body hypothermia of 32-34°C for 72 h and all of them received continuous midazolam infusion for sedation. Serum concentrations of midazolam and its metabolites 1-hydroxy-midazolam and 4-hydroxy-midazolam were measured during hypothermia and the rewarming period. Renal and hepatic parameters were assessed to take into account the influence of asphyxia related renal or hepatic impairment.We found a high interindividual variability of serum midazolam concentrations in asphyxiated neonates with therapeutic hypothermia; median midazolam concentration was 369.3 ng/ml (minimum 36.6; maximum 3 218.6 ng/ml). The population pharmacokinetic model revealed a midazolam clearance of 2.57 ml/kg/min, comparable to midazolam clearances observed in normothermic critically ill neonates. However, midazolam clearance was significantly decreased in patients with asphyxia related renal and hepatic impairment.It seems that isolated hypothermia does not significantly influence midazolam metabolism. However, neonates with asphyxia related hepatic and renal impairment are at risk of generating unexpectedly high serum midazolam concentrations. In addition pronounced interindividual variability of midazolam metabolism may contribute to dangerously high midazolam concentrations.
- True and 'Choke' Anastomoses between Perforator Angiosomes: Part II. Dynamic Thermographic Identification. [Journal Article]
- Plast Reconstr Surg 2013 Dec; 132(6):1457-64.
Cadaveric studies have revealed that cutaneous perforators are linked by either reduced-caliber "choke" arteries, or by vessels without change in caliber, the true anastomoses. These true anastomotic vessels are often found in parallel with the cutaneous nerves and accompanying veins, and are associated both experimentally and clinically with larger areas of flap survival. The Doppler probe and computed tomographic angiography are already used preoperatively to determine perforator locations but currently cannot reveal the type of anastomotic connections.Thermal images were taken in a previously described fashion and compared with both computed tomographic angiographic studies where available and with cadaveric angiographic studies previously performed by the authors' laboratory.Perforators larger than 1 mm were accurately localized by thermography when compared with computed tomographic angiography. Perforator angiosome rewarming closely approximated a log-based line of best fit. Interperforator zones were variable in their rewarming and correlated with known anatomical patterns of true and choke anastomoses between perforator angiosomes.Thermography now offers a new modality with which to bridge the gap not only by identifying the perforator "hot spots" but also by the robustness of their interconnections. The pattern of these interconnections seen on thermographic imaging has in turn been found to match those seen in the authors' cadaveric studies.
- Sublingual glyceryl trinitrate and the peripheral thermal responses in normal and cold-sensitive individuals. [JOURNAL ARTICLE]
- Microvasc Res 2013 Nov 23.
Non-freezing cold injury (NFCI) is a prevalent, but largely undiagnosed and poorly understood syndrome afflicting many who, as part of their work or leisure, expose their extremities to cold temperatures. The long term sequelae of NFCI are hyperhidrosis, cold-sensitivity and pain; these can last a lifetime. We tested the hypothesis that, in comparison with a placebo, sublingual glyceryl trinitrate (GTN) would increase the peripheral microcirculation during and after a mild cold challenge of individuals who had not been diagnosed with NFCI, but were cold-sensitive. Naive participants were categorised into two cohort groups: control (n=7) or cold-sensitive (n=6). All participants undertook a standardised two minute cold exposure of their right foot while toe skin temperature (Tsk; infra-red thermograms) and blood flow (toe pad laser Doppler) were measured. GTN increased the rate of rewarming and absolute Tsk of the coldest toe after the cold challenge in cold-sensitive individuals. GTN also increased the blood flow in the great toe during rewarming in some cold-sensitive individuals. We accept our hypothesis and suggest that the impairment in the vasodilatory response seen in individuals with cold-sensitivity can be overcome by the use of GTN, an endothelial-independent NO donor, and thereby improve the rewarming of cooled peripheral tissues.
- Kampo Extract of Shinbuto Improved Refractory Diarrhea in Milroy's Disease. [JOURNAL ARTICLE]
- Glob Adv Health Med 2013 Jan; 2(1):14-17.
Milroy's disease is a hereditary congenital lymphedema caused by lymphatic obstruction. The legs are most commonly affected, but impaired intestinal lymphatic flow can cause loose bowel movements. Here, we report the use of the Kampo extract of shinbuto for successful treatment of and abdominal pain in a patient with Milroy's disease. Milroy's disease was diagnosed because of left leg lymph-edema with onset at birth. Conservative therapy with a compression bandage was applied. However, when the patient moved to Manila at 35 years of age, she was exposed to drastic temperature changes between the air-conditioned cold environment in her room and the hot and humid environment outside. She developed a constitutional state of coldness as in hiesho (え). Then sudden lower abdominal pain and diarrhea began to occur 3 times per week and lasted at least 1 hour, sometimes accompanied by vomiting. It happened particularly when she was exposed to the cold environment and was not related to meals. Conventional anti-cholinergic or antidiarrhetic drugs had no therapeutic effect. These attacks continued in the same frequency for 3 years, so the patient visited a Kampo (traditional Japanese medicine) clinic, where her diagnosis of Milroy's disease-associated diarrhea and abdominal pain was augmented by the Kampo diagnosis of hiesho, suitai (body fluid retention). She was prescribed 7.5 g of shinbuto extract per day (TJ-30; Tsumura Co, Tokyo, Japan). The shinbuto extract significantly reduced abdominal pain and refractory diarrhea to about 2 days per month, and it tapered off completely in 3 months. Shinbuto is usually used against cold-induced diarrhea. Rewarming and water movement by shinbuto resulted in significant improvement in symptoms induced by hiesho and suitai triggered by the cold environment, though the patient's leg swelling did not change.