Hibernation Research Articles

Loss of bone mass can occur in mammals after prolonged disuse but the situation for hibernators that are in a state of torpor for many months of the year is not yet fully understood. The present study assesses the bone remodeling mechanisms present in Daurian ground squirrels (Spermophilus dauricus) during hibernation as compared with a model of hindlimb disuse. Differences in microstructure, mechanical properties, bone remodeling-related proteins (Runx2, OCN, ALP, RANKL, CTK and MMP-9) and key proteins of Wnt/β-catenin signaling pathway (GSK-3β and phospho-β-catenin) were evaluated in ground squirrels under 3 conditions: summer active (SA) vs. hibernation (HIB) vs. hindlimb unloaded (HLU). The results indicated that the body weight in HLU ground squirrels was lower than the SA group, and the middle tibia diameter in the HLU group was lower than that in SA and HIB groups. The thickness of cortical and trabecular bone in femurs from HLU ground squirrels was lower than in SA and HIB groups. Most parameters of the tibia in the HLU group were lower than those in SA and HIB groups, which indicated cortical bone loss in ground squirrels. Moreover, our data showed that the changes in microscopic parameters in the femur were more obvious than those in the tibia in HLU and HIB ground squirrels. The levels of Runx2 and ALP were lower in HLU ground squirrels than SA and HIB groups. The protein levels of OCN were unchanged in the three groups, but the protein levels of ALP were lower in the HLU group than in SA and HIB groups. RANKL, CTK and MMP-9 protein levels were significantly decreased in tibia of HLU ground squirrels as compared with SA and HIB groups. In addition, the protein expression levels of RANKL, CTK and MMP-9 showed no statistical difference between SA and HIB ground squirrels. Thus, the mechanisms involved in the balance between bone formation and resorption in hibernating and hindlimb unloading ground squirrels may be different. The present study showed that in femur, the Wnt signaling pathway was inhibited, the protein level of GSK-3β was increased, and the protein expression of phospho-β-catenin was decreased in the HIB group as compared with the SA group, which indicates that the Wnt signaling pathway has a great influence on the femur of the HIB group. In conclusion, the natural anti-osteoporosis properties of Daurian ground squirrels are seasonal. The squirrels do not experience bone loss when they are inactive for a long time during hibernation, but the mechanisms of anti-osteoporosis did not work in HLU summer active squirrels.

![Figure][1] Peeka, a female grizzly bear, walking on a treadmill while being fed apples to keep her motivated. Photo credit: Anthony Carnahan. In the run up to hibernation, grizzly bears go on a colossal binge, consuming as many calories as possible to get them through the long winter.

For the first time, the causative agent of late blight Phytophthora megasperma Drech. in Kazakhstan found on soybean crops in 2015. It is a quarantine disease. The article provides data on the spread of the disease, describes the symptoms of late blight soy. The frequency of the development of the disease depending on weather conditions has been established, the parasitic kind of the pathogen in Kazakhstan has been identified and biological features have been studied. The source of infection of the disease are plant debris, soil and seeds. All biotic and abiotic factors that weaken plants predispose them to infection. For sowing, only healthy seed material should be used, since the causative agent of late blight hibernates in infected seeds. Timely implementation of agricultural practices during the growing season contributes to the good development of plants, thereby increasing their resistance to the disease. Reduced degree of late blight also with a rarer plant standing. So, in the experiments, when sowing of rows between rows of 60 cm of soybean lesions by late blight was performed, it decreased by 7.7%. Chemical measures for the control of late blight have been developed. Studies on the use of contact and systemic fungicides against late blight soy show that all using drugs inhibit the development of late blight. The most effective fungicides were ridomil and metalaxyl, where their biological effectiveness was 30.7-47.3%. The zoned and promising varieties and hybrids of local and foreign soybean breeding are evaluated for disease resistance. Varieties and hybrids immune to the disease have not been identified. Resistant to late blight French varieties Dicabit.

Our review deals with the unique phenomenon of hibernation in the animal world and its endocrine control. The probable cause of hibernation; how animals overcome the environmental stress by hibernating are discussed here. This review introspects the role of different hormones during the process of hibernation in animals finally the effect of global warming on hibernating animals is also highlighted.

Objective The aim of this study was to assess the role of nitrate-augmented technetium-99m (99mTc) sestamibi imaging in the evaluation of viable myocardium in patients who had ischemic heart disease with depressed left ventricle (LV) systolic function. Background In the setting of acute myocardial infarction, stunning can occur, which is the persistent LV dysfunction following opening of the occluded coronary artery; recovery of function occurs usually within months. In the setting of chronic LV dysfunction, the pathophysiology underlying the dysfunction is referred to as myocardial hibernation. Various imaging techniques have been introduced to detect viability and discriminate this from scar tissue. Patients and methods Between November 2015 and November 2016, 100 patients with a history of myocardial infarction 'functional class II and III' or/and LV dysfunction were included in this multicenter prospective study. All patients underwent 99mTc sestamibi myocardial perfusion imaging under both rest and rest with nitrate conditions. Results Nitrates improved viability detection by myocardial perfusion imaging in patients with depressed LV systolic function. There was significant decrease in the total perfusion defect in rest with nitrate study in comparison with the rest study (P = 0.006). Conclusion In patients with chronic ischemic heart disease with depressed LV systolic function, the use of nitrate-augmented Tc-99m sestamibi protocol in cardiac single photon emission computed tomography imaging results in improved detection of viable but hypoperfused segments. It is a good indicator for differentiating viable tissues from the scar.

![Graphic][1] Hibernators, or animals that ‘sleep’ through the winter to conserve energy, have always fascinated scientists. To date, researchers have studied the adaptations that allow these animals to be inactive for so long and their ability to come back from their slumber at the

The spring started with two popular architectural events in Siberia: in the beginning of March the youth Archbukhta was held in Irkutsk (8), and at the end of the same month the Archigesh was organized for mountain skiers in Novokuznetsk (12). After determination of the winners, our attention was focused on the city environment, the most trending topic of the season. Spring is the best season to take care of the city environment in general and of urban improvement in particular, because the snow melts to uncover all drawbacks of the surface relief. At the same time, contractors wake up from hibernation and are ready to manage the allocated funds. Citizens choose (now by themselves!) the public spaces to be financed by those funds. And so, the interior of the city. In April small towns and historic settlements of our big country prepared submissions to the city environment competition opened by the Ministry of Construction. At the end of May, already under the new Minister of Construction, the results of the competition were announced (40). The winners were congratulated by the Prime-Minister. The rest of the participants cannot but hope that this useful competition will be held annually. The criteria included identity: its recognizing, preservation and even creation. Already in June, Irkutsk architects, urbanists, historians and sociologists discussed the same (their favourite) topic at the Project Baikal Discussion Club Meeting held at a new place, “Boiling Point” (88). The object of the issue is Zaryadye in Moscow, a brand-new urban interior of the capital (131).

As a typical hibernator, the Daurian ground squirrel (Spermophilus dauricus) spends considerable time in a state of reduced activity with prolonged fasting. Despite this, they experience little muscle atrophy and have thus become an interesting anti-disuse muscle atrophy model. The IKKβ/NF-κB signaling pathway is significant to muscle atrophy due to the protein degradation resulting from the upregulation of the E3 ubiquitin ligase MuRF1. The current study showed that the IKKβ/NF-κB signaling pathway and MuRF1 maintained relatively steady mRNA and protein expression levels, with little muscle atrophy observed in the soleus (slow-twitch, SOL) or extensor digitorum longus (fast-twitch, EDL) during hibernation (HIB); however, mRNA expression significantly increased in the SOL and EDL muscle during interbout arousal (IBA), as did the MuRF1 mRNA level in the SOL and MuRF1 protein level in the EDL. Interestingly, the expressions of p50 and MuRF1 significantly increased during HIB in the gastrocnemius (mixed muscle, GAS) and showed moderate atrophy, but dramatically decreased during IBA. Elevated IKKβ and p50 mRNA and protein expression in the cardiac muscle (CM) during HIB did not accompany increased MuRF1 expression or muscle wasting. Importantly, almost all increased or decreased indicators in the tested tissues recovered to pre-hibernation levels after HIB. This is the first study to report on the unexpected regulation of the IKKβ/NF-κB/MuRF1 pathway with remarkable muscle plasticity in Daurian ground squirrels during hibernation. Furthermore, we found that different types of muscles exhibited different strategies to cope with prolonged hibernation-induced disuse muscle atrophy.

Hibernoma are rare benign tumors of brown adipose tissue. The tumor was first described in 1906 by Merkel who named them Pseudolipoma. The term Hibernoma was given by Grey in 1914 because of its similarity to brown fat in hibernating animal. Males are more often involved than females. Here we report on two patients of age group 14 years and 60 years male respectively. The tumor presented with swelling temporal region in first patient and with parietal region swelling in other patient.

Background: Morphological changes of testes and seminiferous epithelium cycle were observed by optical and transmission electron microscopy to determine male reproductive patterns of the hibernating Korean greater horseshoe bat, Rhinolophus ferrumequinum korai. Materials and methods: In this study, 40 male Rhinolophus ferrumequinum korai were collected from abandoned mines in Gyeongnam and Jeonnam provinces of South Korea from January 2014-December 2015. Differentiation process and cytological traits of seminiferous epithelium following monthly changes were examined with electron microscopic techniques and observed by optical and electron microscopy. Results and conclusion: Male reproductive pattern of hibernating Korean R. ferrumequinum korai consists of three main stages. The first is the spermatogenesis stage (from April-September), including spermatocytogenesis (which appears from April-May) and spermiogenesis (from June-September). The activity of spermatogenesis was the highest in August. The lumen of seminiferous tubules was open from mid-April to mid-October. It was closed from November to March of the following year. The second is the phagocytosis stage (from mid-Octobermid- November) that is a purification process to prepare for new spermatogenesis the following year. This period is called the cleansing period. The third is the dormant stage that is a state of holding only spermatogonia and Sertoli cells. It is an adaptation strategy to store energy for long periods of hibernation. Compared to previous studies [1], spermatogenesis period preceded one month earlier. This suggests that temperature increase can impact reproductive development and spermatogenesis.

We compared the effects of hibernation inactivity and 14-day hindlimb unloading in non-hibernating period on biochemical, rheological, and hematological parameters of blood in Daurian ground squirrels (Spermophilus dauricus). Twenty-four squirrels were randomly divided into four groups: control (CON), hibernation (HIB), post-hibernation (POST), and 14-day hindlimb unloading (HU). The results showed that serum enzymes (L-lactate dehydrogenase, alanine aminotransferase, and aspartate aminotransferase) activities decreased in HIB, POST, and HU squirrels compared with CON. Total protein (including albumin and globulin) maintained in HIB but decreased in HU compared with CON. Total cholesterol and high-density lipoprotein-cholesterol increased in HIB but maintained in HU and POST compared with CON. Meanwhile, serum creatinine decreased and urea increased in HU compared with CON. All blood ions concentrations were unchanged in HIB, POST, and HU squirrels compared with CON except calcium which increased in HIB compared with CON, and phosphorus which increased in HIB and POST compared with CON. Most of detected serum biochemical analytes in POST recovered to the CON level. Blood viscosity, which was unchanged in all shear rates in HU, increased in HIB and recovered in POST in lower shear rates compared with CON. Erythrocyte and corpuscular volume decreased in HIB and HU but maintained in POST compared with CON. All the routine hematological parameters recovered in POST as compared with CON except platelet, which decreased in HIB and POST but maintained in HU compared with CON. In conclusion, our results suggested a remarkable ability to maintain blood homeostasis in hibernating squirrels.

Surgeries under Suspended Animation (Hibernation)

Objective To evaluate the predictive role of myocardial viability assessed by 99Tcm-MIBI GSMPI and 18F-FDG PET on the volume change of the left ventricle(LV) after coronary artery bypass graft (CABG) operation. Methods From December 2013 to December 2014, 39 patients (37 males, 2 females; average age (64±9) years) with ischemic cardiomyopathy planned for surgical revascularization in the Third Affiliated Hospital of Soochow University were prospectively recruited. All patients underwent 99Tcm-MIBI GSMPI and myocardial 18F-FDG PET to assess myocardial viability preoperatively and GSMPI to assess myocardial perfusion 3-6 months after CABG. Reduction of LV volume ≥10% was considered significant. Patients were divided into two groups based on the reduction of LV volume, and the clinical data were compared between the two groups including gender, age, BMI, history of hypertension, diabetes, hyperlipidemia, angina pectoris, CCS classification for angina pectoris, NYHA classification for functional status, EDV, ESV, LVEF, preoperative creatinine, Gensini score, the number of viable myocardium, scar and normal myocardium and follow-up duration, by independent-sample t test, χ2 test and Mann-Whitney test. Multivariate logistic regression analysis was performed to determine the factors to predict reduction of LV volume after revascularization. ROC curve analysis was performed to determine the cut off number of hibernating segments for reduction of LV volume after revascularization. Results The number of viable segments in the reduced group (n=26) was significantly higher than that in the non-reduced group ((n=13; 4.5±2.8 vs 2.4±1.5; t=-3.011, P 0.05). The number of viable segments was directly related to reduction of LV volume after revascularization (odds ratio(OR)=2.462, P<0.05). ROC curve analysis revealed that 3 viable segments yielded the highest sensitivity, specificity and accuracy (all were 76.92%; 10/13, 20/26, 30/39) for predicting reduction of LV volume, and the AUC was 0.743. The rate of LV volume reduction in patients with more than 3 viable segments (86.96%, 20/23) was higher than that of patients with less than 3 viable segments (37.50%, 6/16; χ2=10.39, P<0.01). Conclusions The reduced group has more viable segments and less scarring segments than the non-reduced group. The number of viable segments is directly related to LV volume reduction after revascularization. The presence of more than three mismatched segments on GSMPI and myocardial 18F-FDG PET in patients with ischemic cardiomyopathy before CABG is an independent predictor of LV volume reduction. Key words: Coronary disease; Coronary artery bypass; Myocardium; Ventricular function, left; Tomography, emission-computed; Tomography, emission-computed, single-photon; Deoxyglucose; MIBI

A cost of being amicable in a hibernating mammal

How bears keep their bones strong during hibernation

Hibernators strategies to cope with cardiomyocyte stress

Walking hibernation won't save starving polar bears

In order to highlight the temporal dynamics of different stages of follicula distribution on reproductive output, we analysed the female size and the reproductive frequency of the European pond turtle, Emys orbicularis , using 191 ultrasonographic and 67 x-ray images (collected from 2000 to 2011 in two different localities of a coastal plain area of NorthWestern Italy). To compare digital image results we also used anatomical topography of autopsied females. Although reproductive females were significantly longer in one locality and larger in the second one, clutch size did not differ between localities. Two main clutches were produced during a year, with occasionally a third one. Shelled eggs were frequent in May, June and July, while follicula were present till August, with a decrease in follicular size especially in July and August. Despite the presence of a number of follicles in late summer and in autumn, a third expected clutch was only an exceptional event, differently from what happens in other sites of the species’ distribution range. The permanence of follicles after the last deposition is interpreted as a possible extra energy source during the very hot and dry summers of coastal central Italy and for the hibernating phase.

The Bedriaga's Plate-tailed Gecko, Teratoscincus bedriagai, Nikolsky, 1900 is distributed in the northern and eastern deserts of Sistan, Iran and the desert regions of southern Afghanistan. In this research, the male reproductive cycle of this lizard has been studied from 5 April to 5 August, 2013. Totally, 40 adult males were collected by hand at midnight from four adjacent stations in Damghan County, Semnan Province of Iran. Most of the lizards were observed on highly saline, loose soil covered with a thin salt crust, and were common near Tamarix bushes. Animals were transferred to the laboratory and their morphometric characters were measured. After anesthetizing the animals, their testes were removed and processed for morphometric and histological studies. Results showed that the spermatogenesis started after hibernation from early April and ended in August. The peak of spermatogenesis was in May. The numbers of seminiferous tubules were 24-75 and their diameter varied between 72.50 and 232.50 microns. The diameter of tunica albuginea varied between 3.05 and 8.20 microns and diameter of germinal layer varied between 20.40 and 124.30 microns. Spermatogenesis of T. bedriagai in Iran is seasonal and alternates with associate type.

Objective To explore the imaging characteristics and the complementarity of contrast- enhanced cardiac magnetic resonance CMR and nuclear myocardial perfusion/metabolic imaging in the evaluation of myocardial viability in patients with ischemic cardiomyopathy. Methods A total of 111 patients with diagnosed coronary artery disease and left ventricular dysfunction were retrospectively enrolled in this study. All patients underwent CMR and nuclear myocardial imaging within 1 month. Cine CMR was employed to evaluate cardiac function and wall motion. Contrast-enhanced CMR and myocardial perfusion/metabolic images were quantitatively assessed using a standard 17-segment and 5-score system. Dysfunctional segments were classified as viable or non- viable based on contrast- enhanced CMR and myocardial perfusion/metabolic imaging, respectively. No enhancement or sub-endocardial enhancement was defined as viable, while transmural enhancement was defined as non-viable. Severely matched perfusion/metabolism defects on nuclear imaging were assigned as non-viable while other patterns were considered as viable.Kappa index was calculated to evaluate the diagnostic concordance in assessing myocardial viability between contrast- enhanced CMR and myocardial perfusion/metabolic imaging. Results Among 1 887 segments in 111 patients, 80.3%(1 516/1 887) were dysfunctional. Of them, 63.3% (959/1 516) were viable and 36.7%(557/1 516) were non-viable on contrast-enhanced CMR, while 79.7%(1 208/1 516) were viable and 20.3% (308/1 516) were non-viable on nuclear myocardial imaging. The two modalities had a moderate concordance (Kappa=0.46, P<0.01). In segments with normal perfusion and metabolism, 73.9% (431/583) had various extent of enhancement but most of them(84.2%, 363/431) were subendocardial. On the other hand, 21.0% (117/557) segments with transmural enhancement had hibernating myocardium on nuclear imaging. Conclusions Contrast-enhanced CMR and nuclear myocardial imaging have a moderate concordance in the evaluation of myocardial viability in ischemic cardiomyopathy. Combination of the two modalities is expected to improve the diagnostic accuracy in assessing myocardial viability. Key words: Myocardium; Magnetic resonance imaging; Nuclear imaging; Myocardial ischemia