Download the Free Unbound MEDLINE PubMed App to your smartphone or tablet.
Available for iPhone, iPad, iPod touch, and Android.
- Cryopreservation of Passiflora pohlii nodal segments and assessment of genetic stability of regenerated plants. [JOURNAL ARTICLE]
- Cryo Letters 2014 May/June; 35(3):204-215.
Passiflora pohlii is a wild species native to Brazil, with a potential agronomic interest due to its tolerance to soil-borne pathogens that cause damage to the passion fruit culture, and could be used in breeding. Because this species occurs in impacted regions, the goal of this study was the development of in vitro conservation strategies, using nodal segments from axenic plants. Encapsulation-vitrification and vitrification techniques were tested for cryopreservation of nodal segments. The highest recovery (65%) was obtained with the vitrification technique using treatment with the PVS3 vitrification solution from 30 to 120 min. Post-rewarming recovery was achieved on MSM medium supplemented with 30.8 μM BAP with incubation in the dark for 30 days before transfer in the presence of light. No differences were detected between control and cryopreserved materials as assayed by RAPD and ISSR.
- Preserving human cells for regenerative, reproductive, and transfusion medicine. [Journal Article]
- Biotechnol J 2014 Jul; 9(7):895-903.
Cell cryopreservation maintains cellular life at sub-zero temperatures by slowing down biochemical processes. Various cell types are routinely cryopreserved in modern reproductive, regenerative, and transfusion medicine. Current cell cryopreservation methods involve freezing (slow/rapid) or vitrifying cells in the presence of a cryoprotective agent (CPA). Although these methods are clinically utilized, cryo-injury due to ice crystals, osmotic shock, and CPA toxicity cause loss of cell viability and function. Recent approaches using minimum volume vitrification provide alternatives to the conventional cryopreservation methods. Minimum volume vitrification provides ultra-high cooling and rewarming rates that enable preserving cells without ice crystal formation. Herein, we review recent advances in cell cryopreservation technology and provide examples of techniques that are utilized in oocyte, stem cell, and red blood cell cryopreservation.
- Survival after avalanche-induced cardiac arrest. [JOURNAL ARTICLE]
- Resuscitation 2014 Jun 24.
Criteria to prolong resuscitation after cardiac arrest (CA) induced by complete avalanche burial are critical since profound hypothermia could be involved. We sought parameters associated with survival in a cohort of victims of complete avalanche burial.Retrospective observational study of patients suffering CA on-scene after avalanche burial in the Northern French Alps between 1994 and 2013. Criteria associated with survival at discharge from the intensive care unit (ICU) were collected on scene and upon admission to Level-1 trauma center. Neurological outcome was assessed at 3 months using cerebral performance category score.Forty-eight patients were studied. They were buried for a median time of 43min (25-76min; 25-75(th) percentiles) and had a pre-hospital body core temperature of 28.0°C (26.0-30.7). Eighteen patients (37.5%) had pre-hospital return of spontaneous circulation and 30 had refractory CA. Rewarming of 21 patients (43.7%) was performed using extracorporeal life support. Eight patients (16.7%) survived and were discharged from the ICU, three (6.3%) had favorable neurological outcome at 3 months. Pre-hospital parameters associated with survival were the presence of an air pocket and rescue collapse. On admission, survivors had lower serum potassium concentrations than non-survivors: 3.2mmol/L (2.7-4.0) versus 5.6mmol/L (4.2-8.0), respectively (P<0.01). They also had normal values for prothrombin and activated partial thromboplastin compared to non-survivors.Our findings indicate that survival after avalanche burial and on-scene CA is rarely associated with favourable neurological outcome. Among criteria associated with survival, normal blood coagulation on admission warrants further investigation.
- Moderate-Dose Sedation and Analgesia During Targeted Temperature Management After Cardiac Arrest. [JOURNAL ARTICLE]
- Neurocrit Care 2014 Jun 25.
Sedation and analgesia regimens during targeted temperature management (TTM), after cardiac arrest varies widely, are poorly described in the literature and may have a negative impact on outcome. Since implementing TTM in 2005, we have used moderate-dose sedation and describe our experience with this approach.In this retrospective review, we included patients treated with TTM for cardiac arrest at our institution for 2008-2012. Patients received TTM if they did not follow verbal commands following cardiac arrest, regardless of place of arrest or rhythm. Utstein-compatible data were prospectively entered into the International Cardiac Arrest Registry, supplemented by review of nursing, pharmacy, and physical therapy records. We report analgesic and sedative medications and doses during the 24 h of active TTM at 33 °C, resource utilization, and important clinical events.166 patients treated with TTM after in- and out-of-hospital cardiac arrest with complete data were included. Overall survival was 42 %, median time to following commands was 3 h after rewarming (-6, 14), time to spontaneous breathing trial was 19 h (5-35), time to extubation was 28 h (9-60), and 59 % of survivors were discharged directly home at 13 (10-20) days. The incidence of seizure was 6 %, septic shock 4 %, and pneumonia 32 %. Four survivors required tracheostomy at 8, 8, 12, and 16 days.A moderate-dose sedation and analgesia regimen was well tolerated and effective during therapeutic hypothermia after cardiac arrest and is an effective alternative to very deep sedation. We recommend more complete description of sedation and analgesia protocols in future studies, including expanded outcome reporting to include variables affected by sedation therapy. Further study is required to define which sedation approach for TTM may be best.
- Core body temperature control by total liquid ventilation using a virtual lung temperature sensor. [JOURNAL ARTICLE]
- IEEE Trans Biomed Eng 2014 Jun 20.
In total liquid ventilation (TLV), the lungs are filled with a breathable liquid perfluorocarbon (PFC) while a liquid ventilator ensures proper gas exchange by renewal of a tidal volume of oxygenated and temperature controlled PFC. Given the rapid changes in core body temperature generated by TLV using the lung has a heat exchanger, it is crucial to have accurate and reliable core body temperature monitoring and control. This study presents the design of a virtual lung temperature sensor to control core temperature. In a first step, the virtual sensor, using expired PFC to estimate lung temperature noninvasively, was validated both in vitro and in vivo. The virtual lung temperature was then used to rapidly and automatically control core temperature. Experimentations were performed using the Inolivent-5.0 liquid ventilator with a feedback controller to modulate inspired PFC temperature thereby controlling lung temperature. The in vivo experimental protocol was conducted on 7 newborn lambs instrumented with temperature sensors at the femoral artery, pulmonary artery, oesophagus, right ear drum and rectum. After stabilization in conventional mechanical ventilation, TLV was initiated with fast hypothermia induction, followed by slow posthypothermic rewarming for 1 hour, then by fast rewarming to normothermia and finally a second fast hypothermia induction phase. Results showed that the virtual lung temperature was able to provide an accurate estimation of systemic arterial temperature. Results also demonstrate that TLV can precisely control core body temperature and can be favorably compared to extracorporeal circulation in terms of speed.
- Influence of ISDN, l-NAME and selenium on microcirculation, leukocyte endothelium interaction and angiogenesis after frostbite. [JOURNAL ARTICLE]
- Burns 2014 Jun 20.
The body of knowledge regarding the different facets of frostbite injury continues to expand. However, beside the administration of physiological saline, local rewarming, local disinfection and symptomatic medications, today no causal therapy is known which would accelerate angiogenesis and wound healing. The aim of this study was to investigate the influences of dilative acting drugs on microcirculation, angiogenesis and leukocyte behavior.Ears of male hairless mice (n=40) were inflicted with full thickness frostbites using a cold air jet. Then the affects of four intraperitoneal injections of isosorbitdinitrate (ISDN, n=10), l-nitroarginine-methyl-ester (l-NAME, n=10), selenium (n=10) or sodium chloride (n=10; each administered to one of four corresponding study groups), on microcirculation, leukocyte-endothelial interaction and angiogenesis were investigated over a 12-day period using intravital fluorescent microscopy.Angiogenesis was most improved by ISDN (36.8 vs. 54.5% non-perfused area on day 3, 3.9 vs. 17.0% on day 7 compared to selenium, p<0.006). Venular diameter was most significantly dilated in the ISDN-group, l-NAME showed significantly decreased diameter over the complete time of 12 days. ISDN had positive influences on edema formation, which was significantly reduced compared to control (27% lower values compared to control; p=0.007 on day 3). The l-NAME-group showed the significant highest leukocyte-adhesion compared to control on days 7 and 12 (53% resp. 58% higher, p<0.006).Overall, out of all the drugs tested, ISDN improved angiogenesis, dilated venules and decreased edema formation and therefore seems to have the greatest positive impact on these crucial parameters after frostbite injury.
- Unintentional perioperative hypothermia is associated with severe complications and high mortality in elective operations. [JOURNAL ARTICLE]
- Surgery 2014 Jun 16.
Hypothermia occurs in as many as 7% of elective colorectal operations and is an underestimated risk factor for complications and death. Rewarming of hypothermic patients alone is not sufficient to prevent such adverse events. We investigated the outcomes of patients who became hypothermic (<35°C) after elective operations and compared them with closely matched, nonhypothermic operative patients to better define the impact of hypothermia on surgical outcomes, as well as to identify independent risk factors for hypothermia.We queried the University HealthSystem Consortium (UHC) database for elective operative patients who became unintentionally hypothermic from October 2008 to March 2012, and identified 707 patients. Exclusion criteria were deliberate hypothermia, age <18 years, or death on day of admission. Separately, to validate the accuracy of hypothermia coding, we reviewed the hospital charts of all University of Louisville Hospital patients with hypothermia whose data were submitted to UHC.All patients from UHC with a code for hypothermia were indeed unintentionally hypothermic. Hypothermic patients undergoing elective operations experienced a 4-fold increase in mortality (17.0% vs 4.0%; P < .001) and a doubled complication rate (26.3% vs 13.9%; P < .001), in which sepsis and stroke increased the most. Several independent risk factors for hypothermia were amenable to preoperative improvement: anemia, chronic renal impairment, and unintended weight loss. Severity of illness on admission, age >65 years, male sex, and neurologic disorders also were risk factors.Hypothermia is associated with an increased rate of mortality and complications. Preventive treatment of these risk factors before operation and aggressive warming measures in the "at risk" population may decrease hypothermia-related morbidity and mortality in elective operations. Randomized-controlled trials should be conducted to evaluate the impact of aggressive warming measures in the at-risk population.
- [Changes on the expression of aquaporin-4 is associated with edema of brain in neonatal rats subjected to hypoxic Ischemic brain damage]. [English Abstract, Journal Article]
- Sichuan Da Xue Xue Bao Yi Xue Ban 2014 May; 45(3):386-9, 409.
To investigate changes of Aquaporin-4 (AQP-4) and the relation of brain edema after different time of hypoxic ischemic brain damage (HIBD).Healthy 3 day-old SD rats (n=60), were divided into Sham group (n=12), the hypoxic ischemic brain damage group (n=48). The rats were subjected to the ligation of right carotid artery (ischemia). After rewarming 30 min with mother, they were sent into a box full with 80 mL/L oxygen and 920 mL/L nitrogen (hypoxia) for 4 h, 8 h, 16 h, 24 h (n=12 respectively). The rats of sham group were subjected to exposure right carotid artery, but were not ligated. Rats of the HIBD group were sacrificed at 4 h, 8 h, 16 h, 24 h of hypoxic ischemic damage and rats of the sham group were sacrificed at 12 h after operation without hypoxic ischemic damage. Then brain water content from left and right hemisphere were investigated respetively to observe brain edema at different time of hypoxic ischemic brain damage, which was followed by the investigation of brain pathology through HE staining. Real time PCR was used to test the level of AQP-4 mRNA.Water content of right brain increased significantly after 8 h, 16 h and 24 h hypoxic ischemic brain damage, compared with the sham group (P < 0.05). Under light microscopy, the size of neurons and glia cells increased gradually during 8-24 h following HIBD. Dissolved Neurons were obviously observed during 16-24 h of HIBD. Glia cells were scarcely distributed. The mRNA expression of AQP-4 in right hippocampus decreased significantly during 4-24h of HIBD by evaluated with real time PCR (P < 0.05), when compared with the sham group.AQP-4 mRNA expression in hippocampus of neonatal rats with HIBD exhibited a significant decrease, which was associated with brain edema. The present findings indicated that AQP-4 may has a novel role in the brain edema in neonatal rats with HIBD.
- Heart rate variability in encephalopathic newborns during and after therapeutic hypothermia. [JOURNAL ARTICLE]
- J Perinatol 2014 Jun 12.
Objective:To evaluate whether heart rate variability (HRV) measures are predictive of neurological outcome in babies with hypoxic ischemic encephalopathy (HIE).Study Design:This case-control investigation included 20 term encephalopathic newborns treated with systemic hypothermia in a regional neonatal intensive care unit. Electrocardiographic data were collected continuously during hypothermia. Spectral analysis of beat-to-beat heart rate interval was used to quantify HRV. HRV measures were compared between infants with adverse outcome (death or neurodevelopmental impairment at 15 months, n=10) and those with favorable outcome (survivors without impairment, n=10).Result:HRV differentiated infants by outcome during hypothermia through post-rewarming, with the best distinction between groups at 24 h and after 80 h of life.Conclusion:HRV during hypothermia treatment distinguished HIE babies who subsequently died or had neurodevelopmental impairment from intact survivors. This physiological biomarker may identify infants in need of adjuvant neuroprotective interventions. These findings warrant further investigation in a larger population of infants with HIE.Journal of Perinatology advance online publication, 12 June 2014; doi:10.1038/jp.2014.108.
- Cold-induced depolarization of insect muscle: Differing roles of extracellular K+ during acute and chronic chilling. [JOURNAL ARTICLE]
- J Exp Biol 2014 Jun 4.
Insects enter chill coma, a reversible state of paralysis, at temperatures below their critical thermal minimum (CTmin), and the time required for an insect to recover after a cold exposure is termed chill coma recovery time (CCRT). The CTmin and CCRT are both important metrics of insect cold tolerance that are used interchangeably although chill coma recovery is not necessarily permitted by a direct reversal of the mechanism causing chill coma onset. Onset and recovery of coma have been attributed to loss of neuromuscular function due to depolarization of muscle fibre membrane potential (Vm). Here we test the hypothesis that muscle depolarization at chill coma onset and repolarization during chill coma recovery are caused by changes in extracellular [K(+)] and/or directly by low temperature. Using Locusta migratoria we measured in vivo muscle resting potentials of the extensor tibialis during cooling, following prolonged exposure to -2°C and during chill coma recovery, and related changes in Vm to transmembrane [K(+)] balance and temperature. Although Vm was rapidly depolarized by cooling, hemolymph [K(+)] did not rise until locusts had spent considerable time in the cold. Nonetheless, a rise in hemolymph [K(+)] during prolonged cold exposure further depressed muscle resting potential and slowed recovery from chill coma upon rewarming. Muscle resting potentials had a bimodal distribution, and with elevation of extracellular [K(+)] (but not temperature) muscle resting potentials become unimodal. Thus, a disruption of extracellular [K(+)] does depolarize muscle resting potential and slow CCRT, but it is unrelated to the insect CTmin, which is caused by an as-yet-unknown effect of temperature on muscle function.