The effect of environmental temperature (20 degrees and 30 degrees) after injury on the catabolism of albumin in man

Albumin turnover was studied using ¹²⁵I-labelled albumin in 11 injured patients, mainly fractures of major long bones, who were treated at an environmental temperature of 20° (relative humidity 50–60%) and in nine patients nursed at 30°, relative humidity 35–45%. Plasma albumin, expressed either as intravascular content or as plasma concentration, decreased to reach a minimum on day 5 after injury at 20°. No significant alteration occurred in those patients treated at 30°.No change was found in the absolute rate of albumin catabolism (mass catabolised per unit time) at either environmental temperature but the fractional catabolic rate (absolute rate expressed as a fraction of the intravascular albumin content) was increased at 20° with a similar time sequence to the change in intravascular albumin content. Little alteration occurred in the fractional catabolic rate at the 30° environment. The ratio of extravascular to intravascular radioactivity showed no demonstrable change with time after injury and no difference was found between the mean value at 20° and that at 30°, although both were greater than normal.     

Studies on platelets exposed to or stored at temperatures below 20 degrees C or above 24 degrees C

BACKGROUND : Platelet concentrates (PCs) may be subjected to temperatures outside 20 to 22 degrees C during shipping or storage, which may have an adverse effect on platelet quality. STUDY DESIGN AND METHODS : These studies systematically evaluated the effect of short- term exposure (≤ 24 hours) of platelets to temperatures above 22° or below 20° C as part of standard 5-day PC storage at 22° C, as well as the effect of long-term storage (5 days) at 24 and 26° C. For the short-term exposure studies, up to 6 units of Day 1 standard PCs were mixed, split, and returned to the containers. Test units were then stored without agitation in an incubator at a specific temperature (4, 12, 16, or 18° C) for various times up to 24 hours, after which they were stored with agitation at 22° C. One unit acted as control and was stored at 20 to 22° C throughout the 5-day storage period. Loss of platelet discoid shape was determined photometrically by the extent of shape change assay, by an increase in apparent platelet size by morphologic evaluation, and by swirling. RESULTS : A gradual loss of platelet discoid shape occurred at temperatures below 20° C. For similar periods, a greater difference between test and control PCs was observed in units held at 4° C than in those held at 16° C. The data were fitted to an equation to relate platelet discoid shape (% of control) to exposure temperature and time. Assuming that a 20-percent decrease or more in the extent of shape change assay represents a significant loss in platelet viability, the equation predicts that such a loss occurs when the platelets are exposed to 16° C for ≥16 hours, to 12° C for ≥10 hours, or to 4°C for ≥6 hours, whereas exposure to 18° C for ≤24 hours has no significant effect. Storage for 5 days at temperatures ≤26° C was not associated with any significant reduction in platelet discoid shape or other measures of platelet quality. CONCLUSION : There was a gradual loss of platelet discoid shape at exposure temperatures < 20°C, which worsened as temperatures decreased and exposure times increased to 24 hours. This relationship can be described in an equation that could be used as a guideline for allowable exposure conditions.     

Study by Direct Calorimetry of Thermal Balance on the First Day of Life

Abstract. Using a gradient layer direct calorimeter, total heat losses were measured in 69 full term new-borns at 5 different ambient temperatures (T_A): 28, 30, 32, 34 and 36° C. The relative humidity of the air was kept constant at 50%. Oesophageal temperature (T_eg) and mean skin temperature (T?_s) were continuously recorded. All experiments lasted at least one hour. The mean total heat loss was at 28° C: 3.55 W/kg; at 30° C: 2.97 W/kg; at 32° C: 2.35 W/kg; at 34° C: 1.92 W/kg and at 36° C: 2.05 W/kg. Dry heat loss was proportional to the external temperature gradient. Evaporative heat loss was constant when new-borns were not subjected to heat or cold stress, with a mean of 0.39 W/kg. This value is a measurement of insensible perspiration. Sweating was elicited at a T_A of 36° C when the internal temperature gradient reached a mean value of 0.68° C. Heat storage (S). was calculated and was found to be negative at a T_A of 28 and 30° C, and positive at 34 and 36° C. A regression analysis between heat storage and total heat loss showed a mean heat loss of 2.61 W/kg when the new-borns were in thermal equilibrium (S= 0). This occured in most babies at a T_A slightly below 32° C. A minimal metabolic rate of about 6.0 ml kg^-1 min^-1, determined by direct calorimetry and calculation of S, was found at a T_A of 34 and 36° C. The cutaneous thermal conductance, which is an index of cutaneous blood flow was minimal at a T_A of 30° C. It increased sharply when T?_s reached 36.3° C. These data indicate that the range of thermal comfort on the first day of life in normal full-term new-borns is very narrow and that there is a perfect thermal balance at a T_A slightly below 32° C. However, at this T_A, the metabolic rate is not at a minimal level.     

Effect on platelet properties of exposure to temperatures below 20 degrees C for short periods during storage at 20 to 24 degrees C

Background : When platelet concentrates (PCs) are shipped over long distances, it is not always possible to ensure that their temperature is maintained at 20 to 24°C. In addition, PCs are not agitated as during routine storage. Study Design and Methods : Studies have been conducted to evaluate how exposure to temperatures below 20°C in the absence of agitation influences properties of platelets. In initial studies, exposure to 4°C for 3 or 5 hours or to 12°C for 5 or 17 hours on Day 2 of a 5- to 6-day storage period was associated with a loss of discoid shape. This was reflected by slightly lower but statistically different morphology scores after storage compared to those observed with control platelets that were stored only at 20 to 24°C. In addition, a qualitative difference in morphology was noted in controls and PCs held at 16°C for 17 hours. In more detailed studies, both the in vivo viability and in vitro properties of platelets exposed between Day 1 and Day 2 to either 12°C or 16°C for 17 hours were evaluated. The protocol involved a paired study design (n = 4 for each exposure temperature) with the simultaneous storage of two identical PCs, one exposed to 12 or 16°C and the other one maintained at 20 to 24°C throughout the 5-day storage. Results : Exposure to 12°C significantly reduced (p < 0.05 by paired t test) the in vivo recovery to 37.6 ± 13.8 percent (mean ± 1 SD) from 47.8 ± 11.5 percent and the survival time to 2.0 ± 0.3 days from 6.5 ± 1.4 days. On exposure to 16°C, the differences in viability from those of control units were much less but still significant. The in vivo recovery was 42.7 ± 3.8 percent compared to 49.2 ± 3.0 percent and the survival time was 3.5 ± 1.2 days compared to 6.6 ± 0.3 days. The loss of in vivo viability of the test platelets was associated with a loss of discoid shape, as reflected by morphology scores, extent of shape change, and mean platelet volume. In addition, platelet metabolism also appeared to be affected, as suggested by increased lactate production. All of the in vitro properties except for total ATP and residual glucose that were statistically different from those of controls on exposure to 12°C were also significantly different on exposure to 16°C. Conclusion : These findings demonstrate that platelets undergo substantial changes in in vivo viability and in vitro properties when they are exposed to temperatures below 20°C for short periods.     

Infra-red thermometry: the reliability of tympanic and temporal artery readings for predicting brain temperature after severe traumatic brain injury

Introduction

Temperature measurement is important during routine neurocritical care especially as differences between brain and systemic temperatures have been observed. The purpose of the study was to determine if infra-red temporal artery thermometry provides a better estimate of brain temperature than tympanic membrane temperature for patients with severe traumatic brain injury.

Methods

Brain parenchyma, tympanic membrane and temporal artery temperatures were recorded every 15–30 min for five hours during the first seven days after admission.

Results

Twenty patients aged 17–76 years were recruited. Brain and tympanic membrane temperature differences ranged from -0.8 °C to 2.5 °C (mean 0.9 °C). Brain and temporal artery temperature differences ranged from -0.7 °C to 1.5 °C (mean 0.3 °C). Tympanic membrane temperature differed from brain temperature by an average of 0.58 °C more than temporal artery temperature measurements (95% CI 0.31 °C to 0.85 °C, P < 0.0001).

Conclusions

At temperatures within the normal to febrile range, temporal artery temperature is closer to brain temperature than is tympanic membrane temperature.     

Vitamin C in plasma: a comparative study of the vitamin stabilized with trichloroacetic acid or metaphosphoric acid and the effects of storage at -70 degrees, -20 degrees, 4 degrees, and 25 degrees on the stabilized vitamin

Vitamin C concentration in human plasma was shown to be affected by storage time and temperature as well as by the kind of stabilizer used. Samples were stored for periods of time up to 21 days at temperatures of 25°, 4°, ? 20°, and ? 70°. Stabilizers employed in this study included trichloroacetic acid (TCA) and metaphosphoric acid (MPA). Plasma vitamin C demonstrated maximum stability in TCA or MPA when stored at ? 70°. Other storage conditions tested yielded less accurate vitamin C values.     

I N M EMORY OF K EITH N EELY,P H D,MPA, EMT-P

Abstract

Objective. We compared the use of two active cooling devices with passive cooling in a moderate-temperature (≈22°C) environment on heart rate (HR) and core temperature (T_c) recovery when applied to firefighters following 20 minutes of fire suppression. Methods. Firefighters (23 men, two women) performed 20 minutes of fire suppression at a live-fire evolution. Immediately following the evolution, the subjects removed their thermal protective clothing and were randomized to receive forearm immersion (FI), ice water perfused cooling vest (CV), or passive (P) cooling in an air-conditioned medical trailer for 30 minutes. Heart rate and deep gastric temperature were monitored every 5 minutes during recovery. Results. A single 20-minute bout of fire suppression resulted in near-maximal mean ± standard deviation HR (175 ± 13 b·min^?1, P; 172 ± 20 b·min^?1, FI; 177 ± 12 b·min^?1, CV) when compared with baseline (p < 0.001), a rapid and substantial rise in T_c (38.2° ± 0.7°, P; 38.3° ± 0.4°, FI; 38.3° ± 0.3°, CV) compared with baseline (p < 0.001), and body mass lost from sweating of nearly 1 kilogram. Cooling rates (°C·min) differed (p = 0.036) by device, with FI (0.05 ± 0.04) providing higher rates than P (0.03 ± 0.02) or CV (0.03 ± 0.04), although differences over 30 minutes were small and recovery of body temperature was incomplete in all groups. Conclusions. During 30 minutes of recovery following a 20-minute bout of fire suppression in a training academy setting, there is a slightly higher cooling rate for FI and no apparent benefit to CV when compared with P cooling in a moderate temperature environment.     

Temperature-dependent basal tone in isolated human saphenous veins: implication of TP-receptors

Abstract— Cutaneous blood vessels are very sensitive to changes in environmental temperature. The influence of variations in local temperature on the mechanisms involved in the basal tone, present in isolated human saphenous veins has not yet been studied. In the present study, segments with and without endothelium of human saphenous veins obtained from coronary bypass surgery patients were mounted for isometric tension recording in oxygenated physiological salt solution (PSS). After stabilisation of the basal tone, the local temperature was rapidly either decreased from 37 °C to 24 °C (cooling) or increased from 37 °C to 42°C (warming). When antagonists or inhibitors were used the preparations were incubated for 30 min with the drugs. During basal conditions, cooling caused relaxations of the saphenous vein segments with endothelium and warming caused contractions; the absence of the endothelium did not modify these responses. In veins without endothelium, the warming‐induced contractions were significantly inhibited by verapamil (10 μM) and by the antagonist of TP‐receptors (receptors for thromboxane A₂) Bay u 3405 (1 μM). The warming induced contractions were not affected by cyclooxygenase or lipoxygenase inhibition. At 37°C, the isoprostanes (8‐iso‐PGE₂ and 8‐iso‐PGF_2α) induced potent contractions that were significantly inhibited by Bay u 3405 (1 μM). The data show that a basal tone is present in isolated resting human saphenous vein segments at 37°C. This basal tone is decreased by local cooling and enhanced by local wanning and is not dependent on the presence of the endothelium. The warming‐induced contraction of the veins is mediated by a non‐cyclooxygenase, non‐lipoxygenase metabolite (iso‐prostanc?) that interacts with TP‐receptors and via an extracellular calcium‐dependent pathway.     

Influence of air exposure and storage condition on serum ionized magnesium level

The aim of this study was to evaluate whether reporting serum level of ionized magnesium (iMg) is appropriate when affected by various conditions such as exposure to air and delayed measurement. Serum levels of pH, iMg and normalized magnesium (nMg, normalized or adjusted concentration of iMg to pH?7.40) from 28 inpatients were measured at intervals of 3?min after exposing the samples to air at room temperature. Serum from 30 inpatients was stored in closed tubes at 4°C and ?20°C and iMg and nMg levels were measured after 2 days. It was found that serum iMg and nMg concentrations exposed to air were decreased by 0.0023?mmol/l and 0.0001?mmol/l per minute, respectively. nMg did not display any significant changes compared with iMg at 0?min, whereas iMg showed significant changes, which exceeded between‐day precision. For the stored serum, only iMg of serum at ?20°C showed no statistically significant changes (p?=?0.169). It is concluded that to report the result as iMg, the sample should be kept anaerobically, and if exposed to air, the result should be reported as nMg. For storage, iMg of serum kept anaerobically at ?20°C is reliable.     

Effect of fatty acids on thyroid function tests in vitro and in vivo

Addition of long-chain fatty acids to serum increased thyroxine (T₄), measured by a competitive protein binding assay, and triiodothyronine (T₃) uptake by Sephadex or resin (T₃U tests). This is compatible with the assumption that fatty acids compete with thyroxine for binding sites on T₄-binding proteins. When equimolar concentrations of various saturated and unsaturated fatty acids were added to serum it was observed that the effectiveness in raising tests based on protein binding of thyroid hormones increased with the number of double bonds. Unsaturated fatty acids also increased serum T₃ determined by radioimmunoassay (RIA). T₄(RIA) was not significantly influenced by either saturated or unsaturated fatty acids.Serum T₄(CPB) rose during storage at 22°C and 37°C but was stable at 4°C and — 20°C for periods up to two weeks. The proportional increase in T₄(CPB) and free fatty acids (FFA) indicated that this phenomenon was due, at least partly, to the interference from FFA formed during storage of the serum. There was also a small, significant increase in T₃U, T₃(RIA) and CT₄I (a free thyroxine estimate) after storage of serum at room temperature or higher for one to two weeks. Serum T₄(RIA) did not alter during two weeks of storage.In five subjects with raised serum FFA after eating a fat meal followed by a heparin injection an increase in T₄(CPB), T₃U, T₃(RIA) and CT₄I that was proportional to the increase in FFA was observed. This effect on the thyroid tests was small until the increase in FFA concentration exceeded 2 mmol/1. T₄(RIA) did not respond to the increase in FFA. In ten patients with raised levels of FFA due to uncontrolled diabetes T₄(CPB), T₄(RIA) and T₃(RIA) decreased while T₃U increased. These unexpected alterations were probably related to the severe, chronic illness in these patients. Increased FFA in vivo seem to be of little importance for the interpretation of thyroid tests in clinical practice.     

Glucose variation in centrifuged serum and lithium-heparin gel tubes stored for up to 96 hours at room temperature or 4 °C

Abstract

This study aimed to verify glucose stability within centrifuged serum and lithium-heparin tubes stored at room temperature (RT) or 4?°C. Sixty paired serum (plus gel separator), lithium-heparin (plus gel separator) and K₂-EDTA tubes were centrifuged within 30?min from collection. Thirty serum and lithium-heparin tubes were then stored at RT, whilst the other 30 serum and lithium-heparin tubes were kept at 4?°C. Complete cell blood count was performed in serum and plasma after centrifugation, as well as in K₂-EDTA paired whole blood tubes. Glucose was measured immediately after centrifugation and 3, 6, 24, 48, 72 and 96?h afterwards. Immeasurable blood cells values were found in serum, whilst residual leukocytes and platelets were present in lithium-heparin plasma. Regardless of storage conditions, glucose concentration decreased 3?h after centrifugation in lithium-heparin tubes, displaying uninterrupted reduction until 96?h. Mean decrease per hour was higher in plasma tubes stored at RT than at 4?°C. Performance specification was exceeded between 6 and 24?h of storage in most plasma tubes. Glucose concentration significantly decreased in serum tubes between 24 and 48?h, regardless of storage conditions. The mean glucose variation never exceeded performance specification throughout the study period. Mean glucose decrease per hour in plasma was not associated with blood cells counts before and after centrifugation, and was probably attributable to the presence of blood cells entrapped within the gel. Delayed glucose measurement in centrifuged serum tubes may be clinically viable up to 96?h, whilst it may be unadvisable in centrifuged lithium-heparin tubes.     

Effects of spinal immobilization at 20° on end-tidal carbon dioxide

ObjectiveThe aim was to determine the effect on end-tidal carbon dioxide (ETCO₂) of spinal immobilization (SI) at a conventional 0° angle and to investigate the usefulness of immobilization at a 20° angle for preventing possible hypoventilation.MethodsThe study included 80 healthy volunteers, randomly divided into two groups. Spinal backboards and cervical collars were applied in Group 1 using a 0° angle and in Group 2 using a 20° angle, with the head up. SI was continued for 1 h, and ETCO₂ values were measured at the 0th, 30th and 60th minute.ResultsThere were no significant differences between the groups in 0th and 30th minute ETCO₂. However, after 60th minute, results showed a statistically significant increase in ETCO₂ in Group 1 (35.5 mmHg [IQR 25–75:35–38]) compared to Group 2 (34 mmHg [IQR 25–75:33–36]) (p < 0.001). During SI, there was a statistically significant increase in ETCO₂ in Group 1 (35 mmHg [IQR 25–75:34–36], 35.5 mmHg [IQR 25–75:34–37] and 36 mmHg [IQR 25–75:35–38] respectively at the 0th, 30th and 60th minute after SI) (p < 0.001) and no change in Group 2. Also, we found statistically significant differences between ΔETCO₂ levels in Groups 1 and 2 at all 3 time intervals.ConclusionConventional SI with an angle of 0° led to an increase in ETCO₂ while subjects immobilization at a 20° angle maintained their initial ETCO₂ values. Immobilization at 20° may prevent decompensation in patients who have thoracic trauma or lung diseases or those who are elderly, pregnant, or obese.     

Increase in Temperature Induces the Malathion Toxicity in <Emphasis Type="Italic">Pangasianodon hypophthalmus</Emphasis>: A Short Term Acute Test

The study was conducted to evaluate the effect of higher temperature beyond optimum range on acute toxicity for malathion (effective concentration 50 %) in Pangasianodon hypophthalmus. A 2 days renewal bioassay system for 96 h was used to determine LC₅₀ value of malathion at three different regimes of temperature that is 30, 32 and 34 °C considering as T1, T2 and T3, respectively. The physico-chemical parameters of water of different treatment groups were estimated during pre and post-exposure of test chemical, following standard methods. The result of short term acute toxicity test at 96 h LC₅₀ values through probit analysis was found to be 7.76, 6.45 and 4.46 µL L^?1 for T1, T2, and T3, respectively. The 96 h LC₅₀ of malathion at 34 °C was found to be significantly (p < 0.01) lower as compared with estimated LC₅₀ for malathion at 30 and 32 °C. High temperature and free carbon dioxide coupled with low dissolved oxygen were significantly noticed in T3 group when compared to T1 and T2 groups. Lower LC₅₀ of malathion at 34 °C as compared to 30 and 32 °C showed that at a higher temperature, the toxicity of malathion increased, signifying diminished fish protective response to malathion toxicity. The current study reflects the impact of increased temperature on pesticide toxicity in the aquatic ecosystem, alarming the aqua farmers to judiciously use malathion in ponds.     

Effects of head flexion posture on the multidirectional static force capacity of the neck

BackgroundNeck muscle force protects vertebral alignment and resists potentially injurious loading of osteoligamentous structures during head impacts. As the majority of neck muscles generate moments about all three planes of motion, it is not clear how the force capacity of the neck might be modulated by direction of force application and head posture. The aim of our study was to measure the multidirectional moment-generating capacity of the neck and to evaluate effects of 20° of head flexion, a common head position in contact sports, on the measured capacity.MethodsWe conducted a cross-sectional study, with 25 males, 20–30 years old, performing maximum voluntary contractions, with ballistic intent, along eight directions, set at 45° intervals in the horizontal plane of the head. Three-dimensional moments at C₃ and T₁ were calculated using equations of static equilibrium. The variable of interest was the impulse of force generated from 0–50 ms. Effects of direction of force application and head posture, neutral and 20° flexion, were evaluated by two-way analysis of variance and linear regression.FindingsImpulse of force was lower along diagonal planes, at 45° from the mid-sagittal plane, compared to orthogonal planes (P < 0.001). Compared to neutral posture, head flexion produced a 55.2% decrease in impulse capacity at C₃ and 45.9% at T₁.InterpretationThe risk of injury with head impact would intrinsically be higher along diagonal planes and with a 20° head down position due to a lower moment generating capacity of the neck in the first 50 ms of force application.     

Serum growth factor stability in different eye drop packaging systems during storage

Serum eye drops (SED) have shown beneficial effects in patients suffering from dry eye syndrome and are manufactured for an increasing number of patients in Australia every year. Previous studies have examined the stability of serum growth factors during storage in either experimental vessels not used as the final packaging system or in eye drop bottles. To ensure the quality and safety of SED product manufactured in Australia, the stability of growth factors in serum packaged into two different systems during storage at different temperatures was examined. Healthy blood donors provided a whole blood donation, from which serum was prepared, diluted to 20% and dispensed into either a tube or a vial packaging system. The stability of growth factors, fibronectin and total protein in tube segments was comparable to matched vials samples during storage at −30 °C, 4 °C, 22 °C and 37 °C, with the exception of EGF and fibronectin in 20% SED stored in tube segments, which were more sensitive to storage conditions at 4 °C and 22 °C when compared to vials. Additionally, the growth factor, fibronectin and total protein concentration in both tube segments and vials was stable during storage at −30 °C for at least 9 months. This study highlights the impact of different manufacturing procedures on serum growth factor stability during storage.     

α1‐Adrenoceptors augment thermal hyperalgesia in mildly burnt skin

The effect of the α₁‐adrenoceptor agonist phenylephrine on sensitivity to heat was investigated at three sites of mild burn injury in the cutaneous forearm of 19 healthy participants. Two of the sites were pre‐treated with the α₁‐antagonist terazosin, to determine whether the effect of phenylephrine was mediated by α₁‐adrenoceptors. Terazosin was administered before the burn injury at one site, and after the burn injury at the other site. In another 15 participants, the nociceptive effect of the α₂‐adrenoceptor agonist clonidine was investigated with and without prior treatment with the α₂‐antagonist rauwolscine. Drugs were introduced into the skin by iontophoresis, and burns were induced by heating the skin to 48°C for 2min. Heat pain thresholds to a temperature ramp (0.5°C/s), and heat pain ratings to a thermal stimulus (45°C, 7s), were determined before and after the administration of each drug. Thermal hyperalgesia provoked by phenylephrine was inhibited by terazosin administered after the burn injury, but not by terazosin administered before the burn injury. However, neither α₂‐adrenoceptor stimulation nor blockade affected sensitivity to heat in the mildly burnt skin. These findings suggest that stimulation of cutaneous α₁‐adrenoceptors increased the excitability of heat‐sensitized nociceptive afferents. As terazosin was more effective when administered in burnt skin, an inflammatory response induced by the burn injury may have facilitated access of adrenergic agents to α₁‐adrenoceptors.     

Degree of freezing does not affect efficacy of frozen gloves for prevention of docetaxel-induced nail toxicity in breast cancer patients

Purpose

Frozen gloves (FG) are effective in preventing docetaxel-induced nail toxicity (DNT), but uncomfortable. The preventive effect of FG for DNT was compared using a standard (?25 to ?30°C) or more comfortable (?10 to ?20°C) preparation.

Methods

Breast cancer patients receiving docetaxel were eligible. Each patient wore an FG (prepared at ?10 to ?20°C for 90?min) for 60?min without replacement on the right hand. The left hand was protected by standard methods (FG prepared at ?25 to ?30°C overnight and worn for 90?min with replacement at 45?min). The primary endpoint was DNT occurrence at 5?months. Secondary endpoints included docetaxel exposure [cumulative dose and area under the blood concentration time curve (AUC)] until DNT occurrence and discomfort from FG. The pharmacokinetics of docetaxel was assessed.

Results

From 23 patients enrolled between December 2006 and June 2010, seven who received docetaxel for less than 5?months were excluded from evaluation. The median accumulated docetaxel dose was 700?mg/m² (340–1430?mg/m²). Within 5?months of FG use, none developed protocol-defined DNT in either hand. Two patients (13%) developed DNT at 7.2 and 7.3?months, respectively, both at ?10 to ?20°C. In the control hand (?25 to ?30°C), discomfort occurred in 92% of the cycles, compared to 15% in the experimental hand (?10 to ?20°C). Five patients (22%) experienced pain at ?25 to ?30°C, but none did at ?10 to ?20°C. The degree of docetaxel exposure was not related to DNT occurrence in our study.

Conclusion

A convenient preparation of FG at ?10 to ?20°C is almost as effective as a standard preparation at ?25 to ?30°C, with significantly less discomfort.     

In vitro characterization of phosphatidylglyceroglycerol‐based thermosensitive liposomes with encapsulated 1H MR T1‐shortening gadodiamide

Thermosensitive liposomes (TSL) with encapsulated proton (¹H) magnetic resonance (MR) contrast agents have been proposed for noninvasive online temperature monitoring during tumor treatment using chemotherapy combined with hyperthermia (HT). The technique exploits the fact that water exchange between the TSL interior and exterior is increased and/or the encapsulated ¹H MR contrast agent is released near the gel‐to‐liquid crystalline phase transition temperature (T_m) of TSL and thus shortens the ¹H MR relaxation time of tissue. In this work, newly developed, phosphatidylglyceroglycerol (DPPGOG)‐based TSL with encapsulated ¹H MR longitudinal relaxation time (T₁)‐shortening gadodiamide (Gd‐DTPA‐BMA) were characterized in vitro by measuring the temperature dependence of the T₁ of these gadodiamide‐containing DPPGOG‐TSL samples between 30 and 50°C. The measurements revealed that the T₁ nonlinearly slightly decreased with increasing temperature from 30 to 37°C, mainly due to increased water exchange between the gadodiamide‐containing DPPGOG‐TSL interior and exterior with the exception of negligible gadodiamide release. This implies that gadodiamide‐containing DPPGOG‐TSL were stable at temperatures ≤37°C, which was also confirmed by an independent stability study. From 37 to 44°C, the T₁ nonlinearly markedly decreased with increasing temperature since encapsulated gadodiamide was rapidly released. Above 44°C, gadodiamide was completely released and the T₁ was directly proportional to temperature while heated from 44 to 50°C and cooled from 50 to 30°C, respectively. Additionally, gadodiamide release was theoretically quantified and this calculated concentration was consistent with the actually released amount directly obtained from the cooling course of empty DPPGOG‐TSL with completely released gadodiamide. Copyright © 2008 John Wiley & Sons, Ltd.     

Effects of thermal applications on the abdominal temperature of rats.

The results of thermal applications to the abdomens of restrained, unanesthetized rats are reported. A silicone envelope through which water at 0. 10, 20, 30, 40, or 50°C circulated was applied while skin surface, subcutaneous, intraperitoneal, and colonic temperatures were measured. Pad applications at 0°C significantly lowered tissue temperature at all four locations measured. Pad applications at 10 and 20°C significantly lowered skin surface, subcutaneous, and intraperitoneal temperatures. Pad applications at 30°C significantly lowered skin surface and subcutaneous temperatures. Pad applications at 40 and 50°C significantly increased skin surface and subcutaneous temperatures, and applications at 50°C also increased intraperitoneal temperature. lntraperitoneal and colonic temperatures were insignificantly affected by pad applications of 30 and 40°C, and colonic temperatures were not significantly altered by any thermal application other than that at 0°C. The findings indicate that application of mild heat or cold (30–40°C) to the abdominal skin of the rat does not alter deep abdominal temperatures, indicating no deep vasomotor response to these thermal applications. The question can be raised whether these results suggest that a similar response may occur in humans.     

Impact of Temperature Gradient on the Indian Major Carp <Emphasis Type="Italic">Catla catla</Emphasis> Larvae

Catla catla (Family: Cyprinidae) were exposed to 10, 15, 20, 25, 30, 33 and 35 °C following 28 °C acclimation temperature. Temperature change rate was 2 °C/day. Mortality rate of fish was recorded. In 10 °C temperature group, 17 and 65 % mortality was recorded at 14 and 10 °C, respectively. Significantly (P < 0.05) higher mortality was recorded in fish exposed at 10–20 °C as compared to other treatments. Cumulative mortality rates were 89, 43, 24, 18, 1, 2, and 3 % in fish exposed at 10, 15, 20, 25, 30, 33, and 35 °C, respectively. In 10 °C temperature group, all fish died within 2 days, whereas in 15 and 20 °C temperature groups, mortality was continued up to 11 days; it was 18 days in 25 °C temperature group. With simple regression analysis for the temperature range (T < 28 °C and T > 28 °C), percentage changes of mortality per fall and increase of ΔT = 1 °C was calculated in the log-linear regression model framework. When temperature was reduced from 28 °C, the cumulative mortality increment in each 1 °C fall was e^.109 = 1.115 (P < 0.05). High R-square value indicated a high variation (96.8 %) in log-transformed mortality for temperature difference. Beta coefficient was less steep when temperature increased beyond 28 °C. The cumulative mortality e^.075 = 1.077 (P > 0.05) was obtained for each 1 °C increase of temperature from 28 °C.