Effect of cryoprotectant and concentration on the sperm quality of walking catfish, Clarias batrachus, post-cryopreservation.

BACKGROUND: Walking catfish, Clarias batrachus is one of the native and most popular freshwater catfish species in Indonesia. However, cultivation faces challenges, particularly due to the scarcity of larvae resulting from underdeveloped breeding technologies. Cryopreservation is a method of storing sperm to maintain viability for a long period and support the breeding technology of the fish. Cryoprotectant, in this context, plays an important role in determining the success of sperm cryopreservation. OBJECTIVE: To determine the best type and concentration of cryoprotectant for cryopreservation of walking catfish sperm. MATERIALS AND METHODS: A total of five different types of cryoprotectants, namely DMSO, glycerol, ethyl glycol, ethanol, and methanol, were tested at four concentration levels namely 0%, 5%, 10%, 15%, and 20%, each with four replications. RESULTS: The type and concentration of cryoprotectant had a significant effect on sperm motility and viability (P < 0.05). The best outcomes were obtained with 5% DMSO and ethyl glycol, 10% glycerol and methanol, as well as 15% ethanol. CONCLUSION: The highest motility and viability values were obtained with 5% DMSO, resulting in its recommendation for cryopreservation of walking catfish sperm. Doi.org/10.54680/fr24510110612.

Motility, viability and fertility of goldfish Carassius auratus (Pisces: Cyprinidae) post short-term cryopreservation.

BACKGRUND: Goldfish Carassius auratus is a popular ornamental fish extensively cultured worldwide. Sperm cryopreservation is a common fish breeding method that ensures sperm availability around the year. Studies on cryopreservation of goldfish sperm, especially on the suitability of cryoprotectant types and pre-freezing time, are scarcely available. OBJECTIVE: To determine the most suitable type of cryoprotectant and pre-freezing for the successful cryopreservation of goldfish sperm. MATERIALS AND METHODS: A completely randomized design with two factors was utilized in this study. The first factor is the type of cryoprotectants, which included methanol, ethanol, ethylene glycol, glycerol, and DMSO. The second is pre-freezing times of 10, 20, 30, and 40 min at each of the pre-freezing temperatures of 4 degree C, -10 degree C, and -79 degree C, meaning that the total times for the ramping down of temperature were 30, 60, 90 and 120 min, respectively. The Ringer solution and 10% egg yolk were used as extender and extracellular cryoprotectant. The sperm was stored at -179 degree C for 7 days. RESULTS: The ANOVA test showed that cryoprotectants and pre-freezing significantly affected the motility, viability, and fertility of goldfish sperm after freezing in liquid nitrogen for 7 days (P<0.05). Furthermore, 10% DMSO combined with 15% egg yolk with an pre-freezing time of 20 min can maintain sperm motility, viability, and fertility higher than other treatments, by 79%, 80%, and 33%, respectively. The agarose gel electrophoresis showed no DNA fragmentation in all samples, including fresh sperm. CONCLUSION: We conclude that 10% DMSO combined with 15% egg yolk and 20 min pre-freezing is the best treatment for goldfish sperm cryopreservation. DOI: 10.54680/fr23310110412.

In multiple situational light settings, visual observation for skin colour assessment is comparable with colorimeter measurement.

BACKGROUND: Finding inexpensive and reliable techniques for assessing skin colour is important, given that it is related to several adverse human health outcomes. Visual observation is considered a subjective approach assessment and, even when made by trained assessor, concern has been raised about the need for controlled lighting in the study venue. The aim of this study is to determine whether visual skin colour assessments correlate with objective skin colour measurements in study venues with different lighting types and configurations. METHODS: Two trained investigators, with confirmed visual acuity, visually classified the inner, upper arm skin colour of 556 adults using Munsell(®) colour classifications converted to Individual Typology Angle (°ITA) values based on published data. Skin colour at the same anatomic site was also measured using a colorimeter. Each participant was assessed in one of 10 different buildings, each with a different study day. Munsell(®) -derived °ITA values were compared to colorimeter °ITA values for the full sample and by building/day. RESULTS: We found a strong positive, monotonic correlation between Munsell(®) derived °ITA values and colorimeter °ITA values for all participants (Spearman ρ = 0.8585, P < 0.001). Similar relationships were found when Munsell(®) and colorimeter °ITA values were compared for participants assessed in the same building for all 10 buildings (Spearman ρ values ranged from 0.797 to 0.934, all correlations were statistically significant at P < 0.001). CONCLUSION: It is possible to visually assess individual skin colour in multiple situational lighting settings and retrieve results that are comparable with objective measurements of skin colour. This was true for individuals of varying population groups and skin pigmentation.

Difficult airway communication between anaesthetists and general practitioners.

BACKGROUND AND AIMS: Advance warning of patients who are difficult to intubate may prevent an airway catastrophe but relies on effective communication between specialties. Anaesthetists aim to inform general practitioners whenever a difficult airway is encountered and expect general practitioners to include this information in subsequent referrals. We investigated how anaesthetists communicated with general practitioners, their knowledge of the Read Code (used by general practitioner computer systems) for difficult tracheal intubation, and how likely general practitioners were to pass the information on. METHODS AND RESULTS: We surveyed 631 consultant anaesthetists and 217 general practitioners. We found only 125 (20%) anaesthetists consistently wrote difficult airway letters to general practitioners. Only 20 (3%) knew the Read Code for difficult intubation (SP2y3), although 454 (72%) thought it to be useful. Most general practitioners (212, 98%) thought airway information to be important, but only half receiving a difficult airway communication forwarded it on. General practitioners recommended including the Read Code SP2y3 and labelling it 'high priority', ensuring that 'Difficult Tracheal Intubation' would be listed in the Emergency Care Summary generated for hospital referrals. CONCLUSION: Communication between anaesthetists and general practitioners is currently poor, but could be improved by simplifying difficult airway letters and including the SP2y3 code and a statement of priority.

Glacier retreat reorganizes river habitats leaving refugia for Alpine invertebrate biodiversity poorly protected.

Alpine river biodiversity around the world is under threat from glacier retreat driven by rapid warming, yet our ability to predict the future distributions of specialist cold-water species is currently limited. Here we link future glacier projections, hydrological routing methods and species distribution models to quantify the changing influence of glaciers on population distributions of 15 alpine river invertebrate species across the entire European Alps, from 2020 to 2100. Glacial influence on rivers is projected to decrease steadily, with river networks expanding into higher elevations at a rate of 1% per decade. Species are projected to undergo upstream distribution shifts where glaciers persist but become functionally extinct where glaciers disappear completely. Several alpine catchments are predicted to offer climate refugia for cold-water specialists. However, present-day protected area networks provide relatively poor coverage of these future refugia, suggesting that alpine conservation strategies must change to accommodate the future effects of global warming.

Controlled release recombinant human interferon-α2b for treating patients with chronic hepatitis C genotype 1: a phase 2a clinical trial.

Better convenience and tolerability and sustained therapeutic concentrations might improve interferon (IFN) treatment for chronic hepatitis C virus (HCV) infection. In an open-label, randomized study, controlled release free (chemically unmodified) recombinant human IFN-α(2b) in poly(ether-ester) microspheres (CR-rhIFN-α(2b)), was injected at doses of 160, 320, 480 or 640 µg every 2 weeks for 12 weeks with concomitant weight-based oral ribavirin in 32 treatment-naïve patients with chronic HCV genotype 1. Treatment was well tolerated, with 31 patients (97%) successfully completing the study. Full doses of CR-rhIFN-α(2b) were administered on 96% of scheduled occasions. Flu-like symptoms were generally mild and brief. Injection site reactions developed in 13 patients (41%), and neutropenia occurred in six of eight patients receiving 640 µg. In the 320, 480 and 640 µg groups, 62-75% of patients achieved a ≥2 log(10) HCV RNA reduction by 4 weeks and 88-100% by 12 weeks. For those groups, the pooled median time to ≥2 log(10) reduction was 11 days (95% confidence interval, 7-35 days). In those groups, viral reduction below the limit of detection was accomplished in 25% of patients by 4 weeks and in 62% by 12 weeks. The 160-µg dose was less potent. After CR-rhIFN-α(2b) injection, stable plateau levels of serum IFN-α(2b) were generally reached within 72 h. Treatment-emergent neutralizing antibodies to IFN-α(2b) were observed in one patient. No antibodies to host plant proteins were detected. CR-rhIFN-α(2b) with ribavirin cotherapy was well tolerated and displayed potent early antiviral activity in patients with chronic HCV genotype 1.

Future trends in measuring physiology in free-living animals.

Thus far, ecophysiology research has predominantly been conducted within controlled laboratory-based environments, owing to a mismatch between the recording technologies available for physiological monitoring in wild animals and the suite of behaviours and environments they need to withstand, without unduly affecting subjects. While it is possible to record some physiological variables for free-living animals using animal-attached logging devices, including inertial-measurement, heart-rate and temperature loggers, the field is still in its infancy. In this opinion piece, we review the most important future research directions for advancing the field of 'physiologging' in wild animals, including the technological development that we anticipate will be required, and the fiscal and ethical challenges that must be overcome. Non-invasive, multi-sensor miniature devices are ubiquitous in the world of human health and fitness monitoring, creating invaluable opportunities for animal and human physiologging to drive synergistic advances. We argue that by capitalizing on the research efforts and advancements made in the development of human wearables, it will be possible to design the non-invasive loggers needed by ecophysiologists to collect accurate physiological data from free-ranging animals ethically and with an absolute minimum of impact. In turn, findings have the capacity to foster transformative advances in human health monitoring. Thus, we invite biomedical engineers and researchers to collaborate with the animal-tagging community to drive forward the advancements necessary to realize the full potential of both fields. This article is part of the theme issue 'Measuring physiology in free-living animals (Part II)'.

Bisphosphonates and osteoporotic fractures: a cross-design synthesis of results among compliant/persistent postmenopausal women in clinical practice versus randomized controlled trials.

UNLABELLED: In a cross-design synthesis, total fractures were similarly reduced by bisphosphonates among postmenopausal women in randomized trials (23.8%) and highly compliant/persistent patients in observational studies of large databases from routine practice (20.3%). Bisphosphonates also reduced nonvertebral, vertebral and hip fractures in randomized trials and observational studies. In the real-word setting, compliant/persistent patients can gain a benefit from bisphosphonates comparable to that of randomized trial participants. INTRODUCTION: The purpose of the study was to determine whether clinical fracture risk reduction by bisphosphonate treatment in women with postmenopausal osteoporosis differs between randomized controlled trials and routine practice. METHODS: Randomized trials comparing bisphosphonate with placebo and observational studies comparing highly compliant/persistent with less compliant/persistent patients were sought by electronic searches and ancillary methods. Clinical fracture data were extracted from the study reports and quantitatively combined by random effects metaanalysis. RESULTS: The odds ratio (OR) for all clinical fractures in randomized trials of 0.762, with a 95% confidence interval (CI) of 0.680-0.855, was closely similar to that in the observational studies (OR, 0.797; CI, 0.748-0.850). Pooled clinical fracture reduction across both study designs was 22%. Nonvertebral, vertebral, and hip fractures were also significantly reduced by bisphosphonate treatment in both randomized trials and observational studies. CONCLUSIONS: Compliant/persistent patients in the "real-world" setting benefit from bisphosphonate treatment to a similar extent as patients in randomized trials.

Diamond Blackfan anemia is mediated by hyperactive Nemo-like kinase.

Diamond Blackfan Anemia (DBA) is a congenital bone marrow failure syndrome associated with ribosomal gene mutations that lead to ribosomal insufficiency. DBA is characterized by anemia, congenital anomalies, and cancer predisposition. Treatment for DBA is associated with significant morbidity. Here, we report the identification of Nemo-like kinase (NLK) as a potential target for DBA therapy. To identify new DBA targets, we screen for small molecules that increase erythroid expansion in mouse models of DBA. This screen identified a compound that inhibits NLK. Chemical and genetic inhibition of NLK increases erythroid expansion in mouse and human progenitors, including bone marrow cells from DBA patients. In DBA models and patient samples, aberrant NLK activation is initiated at the Megakaryocyte/Erythroid Progenitor (MEP) stage of differentiation and is not observed in non-erythroid hematopoietic lineages or healthy erythroblasts. We propose that NLK mediates aberrant erythropoiesis in DBA and is a potential target for therapy.

Menopausal flushes: a neuroendocrine link with pulsatile luteninizing hormone secreation.

Menopausal flush episodes were found to be invariably associated with the initiation of pulsatile pituitary release of luteinizing hormone. This was not accompanied by a significant change in circulating catecholamine or prolactin concentrations. Since pulsatile luteinizing hormone release results from episodic secretion of luteinizing hormone releasing factor by the hypothalamus, these findings suggest a link between the neuroendocrine mechanisms that initiate such episodic secretion and those responsible for the onset of flush episodes.

Relationship of BMI z score to fat percent and fat mass in multiethnic prepubertal children.

OBJECTIVE: The objective of the study is to examine the validity of body mass index z score (zBMI) as a measure of percent body fat in prepubertal children. METHODS: One hundred eleven multiethnic, healthy, Tanner 1 children aged 6-12 years had fat percent and fat mass measured by the four-compartment method as part of the Paediatric Rosetta Body Composition Cohort. Multiple regression models were developed with fat percent as the dependent variable and zBMI, age, sex and ethnicity as independent variables. RESULTS: Body mass index z score predicted fat percent, adjusted for age in both girls (P < 0.001, RMSE 5.67 and R2 0.54) and boys (P < 0.001, RMSE 4.71, R2 0.69). The average model percent error was 20.3% in girls and 21.6% in boys. zBMI2 predicted fat mass when adjusted for age and zBMI in both girls (P < 0.001, RMSE 2.27 and R2 0.82) and boys (P < 0.001, RMSE 2.08 and R2 0.81). The average percent error was 7.2% in girls and 8.7% in boys. Age was associated with percentage body fat (P < 0.01), while ethnicity was not (P > 0.05). CONCLUSIONS: Given the relatively large error in the models, zBMI are not a useful indicator of fat mass in healthy, Tanner 1 children. zBMI2 scores are associated with significantly lower absolute percent errors in girls and boys.

Catecholamine-mediated reduction in uterine blood flow after nicotine infusion in the pregnant ewe.

The effect of nicotine on uterine blood flow, uterine vascular resistance, and plasma catecholamine concentration was studied in chronically catheterized pregnant sheep equipped with electromagnetic flow probes. The systemic administration of nicotine (14--32 micrograms/kg body wt per min) resulted in a 44% reduction in uterine blood flow (P less than 0.001) and a 203% increase in uterine vascular resistance. Both responses were inhibited by pretreatment with the alpha blocker, phentolamine. Arterial plasma concentrations of norepinephrine and epinephrine, measured by a single isotopic radioenzymatic assay, rose (from 117.9 +/- 6.7 to 201.8 +/- 13.3 pg/ml, P less than 0.001; and from 71.6 +/- 4.5 to 124.1 +/- 8.4 pg/ml, P less than 0.001, respectively) during nicotine infusion. The findings suggest that nicotine exerts a deleterious effect on uterine blood flow mediated through the release of catecholamines.

Cellular localization of AT1 receptor mRNA and protein in normal placenta and its reduced expression in intrauterine growth restriction. Angiotensin II stimulates the release of vasorelaxants.

Angiotensin II (ANG II) is a potent vasoconstrictor and growth promoter. Quantitative receptor autoradiography using the nonselective radioligand [125I]ANG II and subtype-selective competing compounds demonstrated the presence of both ANG II receptor (AT)1 and AT2 receptor recognition sites. In addition, a relatively small population of apparently non-AT1/non-AT2 sites was identified that may represent a novel high affinity ANG II recognition site in human placenta. Using placental membrane preparations, the AT2 receptor antagonist PD123177 failed to compete for [3H]ANG II binding at relevant concentrations, whereas the AT1 receptor antagonist losartan competed in a monophasic manner for all the specific binding, suggesting that the non-AT1/non-AT2 recognition site identified using autoradiography may be a cytosolic binding site. AT1 receptor binding was significantly reduced (P < 0. 02) in intraeuterine growth restriction (IUGR) pregnancies. Western blot analysis confirmed this showing a reduction in AT1 receptor protein. In situ hybridization and immunocytochemistry revealed that AT1 receptor mRNA and protein were localized throughout pregnancy in the cytotrophoblast, syncytiotrophoblast, and extravillous trophoblast, as well as in or around the blood vessels of placental villi. The intensity of the hybridization signal for AT1 receptor mRNA over the syncytium was reduced in IUGR. ANG II evoked a rapid and concentration-dependent release of NO in first trimester cytotrophoblast-like cells that was abolished by the inclusion of the competitive NOS inhibitor NG-monomethyl-L-arginine. Neither losartan nor PD123177 alone significantly inhibited ANG II-evoked NO release, and when cells were stimulated with ANG II in the presence of losartan (10 microM) and PD123177 (10 microM) in combination, NO release was significantly inhibited (P < 0.05). These observations also suggest, for the first time, the existence of a cross-talk between AT1 or AT2 receptors in trophoblast and that the reduction in placental AT1 receptors in IUGR may, in part, account for poor placental function in this disorder.

Differential trafficking of transforming growth factor-beta receptors and ligand in polarized epithelial cells.

Epithelial cells in vivo form tight cell-cell associations that spatially separate distinct apical and basolateral domains. These domains provide discrete cellular processes essential for proper tissue and organ development. Using confocal imaging and selective plasma membrane domain activation, the type I and type II transforming growth factor-beta (TGFbeta) receptors were found to be localized specifically at the basolateral surfaces of polarized Madin-Darby canine kidney (MDCK) cells. Receptors concentrated predominantly at the lateral sites of cell-cell contact, adjacent to the gap junctional complex. Cytoplasmic domain truncations for each receptor resulted in the loss of specific lateral domain targeting and dispersion to both the apical and basal domains. Whereas receptors concentrate basolaterally in regions of direct cell-cell contact in nonpolarized MDCK cell monolayers, receptor staining was absent from areas of noncell contact. In contrast to the defined basolateral polarity observed for the TGFbeta receptor complex, TGFbeta ligand secretion was found to be from the apical surfaces. Confocal imaging of MDCK cells with an antibody to TGFbeta1 confirmed a predominant apical localization, with a stark absence at the basal membrane. These findings indicate that cell adhesion regulates the localization of TGFbeta receptors in polarized epithelial cultures and that the response to TGFbeta is dependent upon the spatial distribution and secretion of TGFbeta receptors and ligand, respectively.

Placental restriction in multi-fetal pregnancies increases spontaneous ambulatory activity during daylight hours in young adult female sheep.

Intrauterine growth restriction (IUGR) has adverse effects on metabolic health and early life, whereas physical activity is protective against later development of metabolic disease. Relationships between birth weight and physical activity in humans, and effects of IUGR on voluntary activity in rodents, are mixed and few studies have measured physical activity in a free-ranging environment. We hypothesized that induced restriction of placental growth and function (PR) in sheep would decrease spontaneous ambulatory activity (SAA) in free-ranging adolescent and young adult progeny from multi-fetal pregnancies. To test this hypothesis, we used Global Positioning System watches to continuously record SAA between 1800 and 1200 h the following day, twice during a 16-day recording period, in progeny of control (CON, n=5 males, 9 females) and PR pregnancies (n=9 males, 10 females) as adolescents (30 weeks) and as young adults (43 weeks). PR reduced size at birth overall, but not in survivors included in SAA studies. In adolescents, SAA did not differ between treatments and females were more active than males overall and during the day (each P<0.001). In adults, daytime SAA was greater in PR than CON females (P=0.020), with a similar trend in males (P=0.053) and was greater in females than males (P=0.016). Adult SAA was negatively correlated with birth weight in females only. Contrary to our hypothesis, restricted placental function and small size at birth did not reduce progeny SAA. The mechanisms for increased daytime SAA in adult female PR and low birth weight sheep require further investigation.

Circadian rhythm in circulating concentration of dihydroxyphenylacetic acid in normal women.

The 24-h patterns of plasma concentration change in dopamine (DA) and its immediate deaminated metabolite, dihydroxyphenylacetic acid (DOPAC), were determined in 6 normal women (16 studies) by a modified radioenzymatic assay. Changes in DOPAC levels exhibited a marked circadian rhythm, with peak during the day and a nadir at night. At 1200 h, the DOPAC concentration increased significantly (P less than 10(-4)) to a peak value 62.9 +/- 8.4 ng/ml) 117% higher than the 24-h mean. At 2200 h, plasma DOPAC decreased (P less than 10(-4)) to a nadir concentration (10.0 +/- 3.3 ng/ml) 66% lower than the 24-h mean. The circadian rhythm of DOPAC could be reproducibly demonstrated over at least 4 successive days in individual subjects. There were no well defined circadian variations in plasma concentrations of DA. Since the plasma DOPAC concentration appears to reflect central nervous system dopaminergic neuronal activity, the present demonstration of a circadian rhythm of plasma DOPAC suggests that the activity of central nervous system DA-containing cells is higher during the day than at night.

Actuarial disease-free survival after prostate cancer brachytherapy using interactive techniques with biplane ultrasound and fluoroscopic guidance.

PURPOSE: To evaluate the effectiveness and safety of interactive transperineal brachytherapy under biplane ultrasound and fluoroscopic guidance in patients with localized prostate cancer. METHODS AND MATERIALS: Brachytherapy using 125I or 103Pd radioactive seeds either alone or in combination with adjunctive external beam radiotherapy (XRT) was administered to 490 patients at a single institution. Post-treatment follow-up included clinical assessment of disease status, assays of serum prostate-specific antigen (PSA) levels and documentation of treatment-related symptoms and complications. RESULTS: Actuarial disease-free survival at 5 yr was 79% (95% CI, 71-85%), and the 5-yr actuarial rate of local control was 98% (95% CI, 94-99%). Post-treatment PSA nadir and pretreatment PSA level were found to be significant predictors of disease-free survival. In patients with a PSA nadir < 0.5 ng/ml, 5-yr disease-free survival was 93% (95% CI, 84-97%), compared with 25% (95% CI, 5-53%) in patients whose PSA nadir was 0.5-1.0 ng/ml and 15% (95% CI, 3-38) in patients with a PSA nadir > 1.0 ng/ml. Brachytherapy was well tolerated with few post-treatment complications. CONCLUSION: A broad range of patients with localized prostate cancer can benefit from transperineal brachytherapy with minimal morbidity. A post-treatment PSA nadir below 0.5 ng/ml provides a useful prognostic indicator of favorable long-term outcome.

Possible interactions between angiotensin II and insulin: effects on glucose and lipid metabolism in vivo and in vitro.

Angiotensin II (ANGII) increases insulin sensitivity in diabetic and non-diabetic subjects, even at subpressor doses, and because there is 'crosstalk' between ANGII and insulin-signaling pathways the underlying mechanism may not be due solely to changes in regional blood flow. A series of experimental studies was undertaken to evaluate the effects of ANGII on glucose and lipid metabolism in vivo and in vitro. Groups of fructose-fed, insulin-resistant Sprague-Dawley (SD) rats were pre-treated with 0.3 mg/kg per day of the AT(1)-receptor antagonist L-158 809 (n=16), or vehicle (n=16), by oral gavage. This was prior to an oral glucose tolerance test (day 5) and measurement of the effects of ANGII infusion (20 ng/kg per min i.v. for 3 h) on whole-body insulin sensitivity using the insulin suppression test (day 7). The effect of ANGII infusion on total triglyceride secretion rate (TGSR) was evaluated in normal SD rats pretreated for 7 days with L-158 809 (n=12) or vehicle (n=12). AT(1)- and AT(2)- receptor mRNA expression and [(3)H]2-deoxyglucose uptake were assessed in cultured L6 myoblasts. Short-term treatment with L-158 809 had no effect on glucose tolerance or fasting triglyceride levels in fructose-fed rats. ANGII infusion had no effect on insulin sensitivity in fructose-fed rats pretreated with vehicle (steady-state plasma glucose (SSPG) values 8.1+/-1.6 vs 8. 4+/-0.4 mmol/l), but pretreatment with L-158 809 resulted in ANGII having a modest insulin antagonist effect in this insulin-resistant model (SSPG values 9.6+/-0.3 vs 7.1+/-0.6, P<0.03). ANGII infusion had no significant effect on TGSR (e.g. 24.6+/-1.4 vs 28.4+/-0.9 mg/100 g per h in vehicle-treated animals). RT-PCR analysis showed that L6 cells express both AT(1)- and AT(2)-receptor mRNA. Incubation with ANGII (10(-9) and 10(-8) M) had no significant effect on the dose-response curve for insulin-stimulated [(3)H]2-deoxyglucose uptake. For example, C(I200) values (dose of insulin required to increase glucose uptake by 200%) were 4.5 x 10(-9) M (control) vs 3.9 x 10(-9) M and 6.2 x 10(-9) M, whereas the positive control (glucagon-like peptide-1) increased insulin sensitivity. Thus, ANGII infusion may have a modest insulin antagonist effect on glucose disposal in insulin-resistant fructose-fed rats pretreated with an AT(1)-blocker, but ANGII has no effect on TGSR or in vitro glucose uptake in L6 myoblasts. These findings are relevant to recent clinical discussions about the metabolic effects of ANGII and renin-angiotensin system blockade.

Failure of retrograde cerebral perfusion to attenuate metabolic changes associated with hypothermic circulatory arrest.

OBJECTIVES: Although retrograde cerebral perfusion has become a popular adjunctive technique and may improve cerebral ischemic tolerance during hypothermic circulatory arrest, direct cerebral metabolic benefit has yet to be demonstrated in human subjects. We investigated the post-arrest metabolic phenomena with and without retrograde cerebral perfusion in patients. METHODS: In a prospective randomized trial, 42 patients undergoing aortic surgery requiring hypothermic circulatory arrest were allocated to receive hypothermic circulatory arrest alone (n = 21) or hypothermic circulatory arrest with additional retrograde cerebral perfusion (n = 21). Circulatory arrest was commenced at 15 degrees C, and retrograde perfusion was instituted through the superior vena cava at a maximum jugular bulb pressure of 25 mm Hg. Transcranial, paired, repeated samples of the arterial and jugular bulb blood were analyzed for oxygen and glucose. Velocity in the right middle cerebral artery was also measured simultaneously. RESULTS: There were 3 (7.1%) deaths and 3 (7.1%) episodes of neurologic deficit. Mean bypass and circulatory arrest duration (in minutes) were similar between groups (P =.4 and.14). The mean retrograde perfusion duration was 23 minutes. Post-arrest nasopharyngeal temperature was similar (15.3 degrees C vs. 15.3 degrees C). Retrograde perfusion did not affect post-arrest oxygen extraction, glucose extraction, or jugular bulb Po(2). There was no immediate lactate release immediately after hypothermic circulatory arrest. CONCLUSIONS: Retrograde cerebral perfusion did not influence immediate post-arrest nasopharyngeal temperature or cerebral metabolic recovery. The low jugular bulb Po(2) suggests equivalent ischemia. These findings cast doubt on the effectiveness of retrograde cerebral perfusion as a metabolic adjunct to hypothermic circulatory arrest.

Albumin versus hydroxyethyl starch in cardiopulmonary bypass surgery: a meta-analysis of postoperative bleeding.

BACKGROUND: This meta-analysis tested the hypothesis that cumulative blood loss during the first 24 hours after cardiopulmonary bypass is lower in patients exposed to albumin than hydroxyethyl starch (HES). METHODS: Randomized controlled trials comparing albumin and HES in cardiopulmonary bypass patients were identified by bibliographic database searches and other methods. RESULTS: Sixteen trials involving 653 randomized patients were included. In 88% of randomized comparisons, postoperative bleeding was lower in the albumin group, and the standardized mean difference in bleeding favoring albumin across all trials (-0.24; 95% confidence interval, -0.40 to -0.08) was statistically significant. Bleeding differences between albumin and either high or medium molecular weight HES were similar. In trials of adults, the pooled mean blood loss in the albumin group was 693+/-350 mL compared with 789+/-487 mL in the HES group. The estimated proportion of adult albumin group patients with blood loss of more than 1,000 mL was 19% compared with 33% of adult HES group patients. Conclusions. Postoperative blood loss is significantly lower in cardiopulmonary bypass patients exposed to albumin than HES.