In situ cardiac performance of Atlantic cod (Gadus morhua) at cold temperatures: long-term acclimation, acute thermal challenge and the role of adrenaline

The resting and maximum in situ cardiac performance of Newfoundland Atlantic cod (Gadus morhua) acclimated to 10, 4 and 0°C were measured at their respective acclimation temperatures, and when acutely exposed to temperature changes: i.e. hearts from 10°C fish cooled to 4°C, and hearts from 4°C fish measured at 10 and 0°C. Intrinsic heart rate (f(H)) decreased from 41 beats min(-1) at 10°C to 33 beats min(-1) at 4°C and 25 beats min(-1) at 0°C. However, this degree of thermal dependency was not reflected in maximal cardiac output (Q(max) values were ~44, ~37 and ~34 ml min(-1) kg(-1) at 10, 4 and 0°C, respectively). Further, cardiac scope showed a slight positive compensation between 4 and 0°C (Q(10)=1.7), and full, if not a slight over compensation between 10 and 4°C (Q(10)=0.9). The maximal performance of hearts exposed to an acute decrease in temperature (i.e. from 10 to 4°C and 4 to 0°C) was comparable to that measured for hearts from 4°C- and 0°C-acclimated fish, respectively. In contrast, 4°C-acclimated hearts significantly out-performed 10°C-acclimated hearts when tested at a common temperature of 10°C (in terms of both Q(max) and power output). Only minimal differences in cardiac function were seen between hearts stimulated with basal (5 nmol l(-1)) versus maximal (200 nmol l(-1)) levels of adrenaline, the effects of which were not temperature dependent. These results: (1) show that maximum performance of the isolated cod heart is not compromised by exposure to cold temperatures; and (2) support data from other studies, which show that, in contrast to salmonids, cod cardiac performance/myocardial contractility is not dependent upon humoral adrenergic stimulation.

Thermal acclimation to 4 or 10 degrees C imparts minimal benefit on swimming performance in Atlantic cod (Gadus morhua L.).

Thermal acclimation is frequently cited as a means by which ectothermic animals improve their Darwinian fitness, i.e. the beneficial acclimation hypothesis. As the critical swimming speed (U (crit)) test is often used as a proxy measure of fitness, we acclimated Atlantic cod (Gadus morhua) to 4 and 10 degrees C and then assessed their U (crit) swimming performance at their respective acclimation temperatures and during acute temperature reversal. Because phenotypic differences exist between different populations of cod, we undertook these experiments in two different populations, North Sea cod and North East Arctic cod. Acclimation to 4 or 10 degrees C had a minimal effect on swimming performance or U (crit), however test temperature did, with all groups having a 10-17% higher U (crit) at 10 degrees C. The swimming efficiency was significantly lower in all groups at 4 degrees C arguably due to the compression of the muscle fibre recruitment order. This also led to a reduction in the duration of "kick and glide" swimming at 4 degrees C. No significant differences were seen between the two populations in any of the measured parameters, due possibly to the extended acclimation period. Our data indicate that acclimation imparts little benefit on U (crit) swimming test in Atlantic cod. Further efforts need to identify the functional consequences of the long-term thermal acclimation process.

An examination of the metabolic processes underpinning critical swimming in Atlantic cod (Gadus morhua L.) using in vivo 31P-NMR spectroscopy.

Traditionally, critical swimming speed has been defined as the speed when a fish can no longer propel itself forward, and is exhausted. To gain a better understanding of the metabolic processes at work during a U(crit) swim test, and that lead to fatigue, we developed a method using in vivo (31)P-NMR spectroscopy in combination with a Brett-type swim tunnel. Our data showed that a metabolic transition point is reached when the fish change from using steady state aerobic metabolism to non-steady state anaerobic metabolism, as indicated by a significant increase in inorganic phosphate levels from 0.3+/-0.3 to 9.5+/-3.4 mol g(-1), and a drop in intracellular pH from 7.48+/-0.03 to 6.81+/-0.05 in muscle. This coincides with the point when the fish change gait from subcarangiform swimming to kick-and-glide bursts. As the number of kicks increased, so too did the Pi concentration, and the pH(i) dropped. Both changes were maximal at U(crit). A significant drop in Gibbs free energy change of ATP hydrolysis from -55.6+/-1.4 to -49.8+/-0.7 kJ mol(-1) is argued to have been involved in fatigue. This confirms earlier findings that the traditional definition of U(crit), unlike other critical points that are typically marked by a transition from aerobic to anaerobic metabolism, is the point of complete exhaustion of both aerobic and anaerobic resources.

Molecular characterisation and expression of Atlantic cod (Gadus morhua) myoglobin from two populations held at two different acclimation temperatures.

Much previous research has demonstrated the plasticity of myoglobin concentrations in both cardiac and skeletal myocytes in response to hypoxia and training. No study has yet looked at the effect of thermal acclimation on myoglobin in fish. Atlantic cod (Gadus morhua) from two different populations, i.e. the North Sea and the North East Arctic, were acclimated to 10 and 4 degrees C. Both the myoglobin mRNA and myoglobin protein in cod hearts increased significantly by up to 3.7 and 2.3 fold respectively as a result of acclimation to 4 degrees C. These increments were largest in the Arctic population, which in earlier studies have been shown to possess cold compensated metabolic demands at low temperatures. These metabolic demands associated with higher mitochondrial capacities may have driven the increase in cardiac myoglobin concentrations, in order to support diffusive oxygen supply. At the same time the increase in myoglobin levels may serve further functions during cold acclimation, for example, protection of the cell against reactive oxygen species, and scavenging nitric oxide, thereby contributing to the regulation of mitochondrial volume density.

Overweight children have a greater proportion of fat mass relative to muscle mass in the upper limbs than in the lower limbs: implications for bone strength at the distal forearm

BACKGROUND: The influence of adiposity on upper-limb bone strength has rarely been studied in children, despite the high incidence of forearm fractures in this population. OBJECTIVE: The objective was to compare the influence of muscle and fat tissues on bone strength between the upper and lower limbs in prepubertal children. DESIGN: Bone mineral content, total bone cross-sectional area, cortical bone area (CoA), cortical thickness (CoTh) at the radius and tibia (4% and 66%, respectively), trabecular density (TrD), bone strength index (4% sites), cortical density (CoD), stress-strain index, and muscle and fat areas (66% sites) were measured by using peripheral quantitative computed tomography in 427 children (206 boys) aged 7-10 y. RESULTS: Overweight children (n = 93) had greater values for bone variables (0.3-1.3 SD; P < 0.0001) than did their normal-weight peers, except for CoD 66% and CoTh 4%. The between-group differences were 21-87% greater at the tibia than at the radius. After adjustment for muscle cross-sectional area, TrD 4%, bone mineral content, CoA, and CoTh 66% at the tibia remained greater in overweight children, whereas at the distal radius total bone cross-sectional area and CoTh were smaller in overweight children (P < 0.05). Overweight children had a greater fat-muscle ratio than did normal-weight children, particularly in the forearm (92 +/- 28% compared with 57 +/- 17%). Fat-muscle ratio correlated negatively with all bone variables, except for TrD and CoD, after adjustment for body weight (r = -0.17 to -0.54; P < 0.0001). CONCLUSIONS: Overweight children had stronger bones than did their normal-weight peers, largely because of greater muscle size. However, the overweight children had a high proportion of fat relative to muscle in the forearm, which is associated with reduced bone strength.

Stroke events, and case fatalities in Switzerland based on hospital statistics and cause of death statistics

OBJECTIVE: In Switzerland there is a shortage of population-based information on stroke incidence and case fatalities (CF). The aim of this study was to estimate stroke event rates and both in- and out-of-hospital CF rates. METHODS: Data on stroke diagnoses, coded according to I60-I64 (ICD 10), were taken from the Federal Hospital Discharge Statistics database (HOST) and the Cause of Death database (CoD) for the year 2004. The number of total stroke events and of age- and gender-specific and agestandardised event rates were estimated; overall CF, in-hospital and out-of-hospital, were determined. RESULTS: Among the overall number of 13 996 hospital discharges from stroke (HOST) the number was lower in women (n = 6736) than in men (n = 7260). A total of 3568 deaths (2137 women and 1431 men) due to stroke were recorded in the CoD database. The number of estimated stroke events was 15 733, and higher in women (n = 7933) than in men (n = 7800). Men presented significantly higher age-specific stroke event rates and a higher age-standardised event rate (178.7/100 000 versus 119.7/100 000). Overall CF rates were significantly higher for women (26.9%) than for men (18.4%). The same was true of out-of-hospital CF but not of in-hospital CF rates. CONCLUSION: The data on estimated stroke events obtained indicate that stroke discharge rate underestimates the stroke event rate. Out-of-hospital deaths from stroke accounted for the largest proportion of total stroke deaths. Sex differences in both number of total stroke events and deaths could be explained by the higher proportion of women than men aged 55+ in the Swiss population.

The AsaP1 peptidase of Aeromonas salmonicida subsp. achromogenes is a highly conserved deuterolysin metalloprotease (family M35) and a major virulence factor

Infections by the bacterium Aeromonas salmonicida subsp. achromogenes cause significant disease in a number of fish species. In this study, we showed that AsaP1, a toxic 19-kDa metallopeptidase produced by A. salmonicida subsp. achromogenes, belongs to the group of extracellular peptidases (Aeromonas type) (MEROPS ID M35.003) of the deuterolysin family of zinc-dependent aspzincin endopeptidases. The structural gene of AsaP1 was sequenced and found to be highly conserved among gram-negative bacteria. An isogenic Delta asaP1 A. salmonicida subsp. achromogenes strain was constructed, and its ability to infect fish was compared with that of the wild-type (wt) strain. The Delta asaP1 strain was found to infect Arctic charr, Atlantic salmon, and Atlantic cod, but its virulence was decreased relative to that of the wt strain. The 50% lethal dose of the AsaP1 mutant was 10-fold higher in charr and 5-fold higher in salmon than that of the wt strain. The pathology induced by the AsaP1-deficient strain was also different from that of the wt strain. Furthermore, the mutant established significant bacterial colonization in all observed organs without any signs of a host response in the infected tissue. AsaP1 is therefore the first member of the M35 family that has been shown to be a bacterial virulence factor.

„Neko bi pomislio da se barem delimično sačuva dogma o monarhiji”: Antilatinski traktati Varlaama Kalabrijskog u srpskoslovenskom prevodu 14. veka

Die antilateinischen Traktate von Gregorios Palamas und Barlaam von Kalabrien stellten für die serbischen Übersetzer des 14. Jahrhunderts eine grosse Herausforderung dar – nicht nur wegen ihres dogmatischen Inhalts, sondern auch wegen des ausgeprägt polemischen Charakters ihrer Argumentation. In diesem Aufsatz wird die argumentative Form der zwei Traktate („opuscula“ ) Barlaams von Kalabrien analysiert, die in cod. Dečani 88 enthalten sind (fol. 38r-81r). Der zweite von ihnen (fol. 69v-81r) richtet sich an ein griechisches (orthodoxes) Auditorium; die Anreden an die Lateiner, die sich darin finden, haben rein rhetorischen Charakter. Der erste Traktat (fol. 39r-69r), der während der Unionsverhandlungen des Jahres 1334/1335 entstand, hat jedoch eine für die byzantinische Unionspolemik eher ungewöhnliche Form: der Dialog mit der Gegenseite ist hier keine rhetorische Fiktion, sondern ein ernstes Anliegen des Autors. Dies hat bereits bei der Rezeption des Traktats im griechisch-athonitischen Milieu den Verdacht geweckt, Barlaam habe den Lateinern unzulässige Zugeständnisse gemacht. Barlaam hat versucht, diesen Verdacht durch metakommunikative Kommentare zu entkräften, die ausschliesslich in der serbisch-kirchenslavischen Übersetzung von Dečani 88 enthalten sind. Der Übersetzer der Traktate hat deren argumentative Form im wesentlichen nicht angetastet und nur gelegentlich versucht, die Zugehörigkeit der einzelnen Argumente dem Leser durch Marginalscholien deutlich zu machen.

Clipping techniques in cerebral aneurysm surgery

The history of cerebral aneurysm surgery owes a great tribute to the tenacity of pioneering neurosurgeons who designed and developed the clips used to close the aneurysms neck. However, until the beginning of the past century, surgery of complex and challenging aneurysms was impossible due to the lack of surgical microscope and commercially available sophisticated clips. The modern era of the spring clips began in the second half of last century. Until then, only malleable metal clips and other non-metallic materials were available for intracranial aneurysms. Indeed, the earliest clips were hazardous and difficult to handle. Several neurosurgeons put their effort in developing new clip models, based on their personal experience in the treatment of cerebral aneurysms. Finally, the introduction of the surgical microscope, together with the availability of more sophisticated clips, has allowed the treatment of complex and challenging aneurysms. However, today none of the new instruments or tools for surgical therapy of aneurysms could be used safely and effectively without keeping in mind the lessons on innovative surgical techniques provided by great neurovascular surgeons. Thanks to their legacy, we can now treat many types of aneurysms that had always been considered inoperable. In this article, we review the basic principles of surgical clipping and illustrate some more advanced techniques to be used for complex aneurysms.

Prevention of ischemic complications during aneurysm surgery

Ischemic complications during aneurysm surgery are a frequent cause of postoperative infarctions and new neurological deficits. In this article, we discuss imaging and neurophysiological tools that may help the surgeon to detect intraoperative ischemia. The strength of intraoperative digital subtraction angiography (DSA) is the full view of the arterial and venous vessel. DSA is the gold standard in complex and giant aneurysms, but due to certain disadvantages, it cannot be considered standard of care. Microvascular Doppler sonography is probably the fastest diagnostic tool and can quickly aid diagnosis of large vessel occlusions. Intraoperative indocyanine green videoangiography is the best tool to assess flow in perforating and larger arteries, as well as occlusion of the aneurysm sac. Intraoperative neurophysiological monitoring with somatosensory and motor evoked potentials indirectly measures blood flow by recording neuronal function. It covers all causes of intraoperative ischemia, provided that ischemia occurs in the brain areas under surveillance. However, every method has advantages and disadvantages. No single method is superior to the others in every aspect. Therefore, it is very important for the neurosurgeon to know the strengths and weaknesses of each tool in order to have them available, to know how to use them for each individual situation, and to be ready to apply them within the time window for reversible cerebral ischemia.

Cause-Specific Long-Term Mortality in Survivors of Childhood Cancer in Switzerland: A Population Based Study.

Survivors of childhood cancer have a higher mortality than the general population. We describe cause-specific long-term mortality in a population-based cohort of childhood cancer survivors. We included all children diagnosed with cancer in Switzerland (1976-2007) at age 0-14 years, who survived ≥5 years after diagnosis and followed survivors until December 31, 2012. We obtained causes of death (COD) from the Swiss mortality statistics and used data from the Swiss general population to calculate age-, calendar year- and sex-standardized mortality ratios (SMR), and absolute excess risks (AER) for different COD, by Poisson regression. We included 3'965 survivors and 49'704 person years at risk. Of these, 246 (6.2%) died, which was 11 times higher than expected (SMR 11.0). Mortality was particularly high for diseases of the respiratory (SMR 14.8) and circulatory system (SMR 12.7), and for second cancers (SMR 11.6). The pattern of cause-specific mortality differed by primary cancer diagnosis, and changed with time since diagnosis. In the first 10 years after 5-year survival, 78.9% of excess deaths were caused by recurrence of the original cancer (AER 46.1). Twenty-five years after diagnosis, only 36.5% (AER 9.1) were caused by recurrence, 21.3% by second cancers (AER 5.3) and 33.3% by circulatory diseases (AER 8.3). Our study confirms an elevated mortality in survivors of childhood cancer for at least 30 years after diagnosis with an increased proportion of deaths caused by late toxicities of the treatment. The results underline the importance of clinical follow-up continuing years after the end of treatment for childhood cancer. This article is protected by copyright. All rights reserved.