Sprint interval training (SIT) is an effective method to maintain cardiorespiratory fitness (CRF) and glucose homeostasis in Scottish adolescents

The present study examined the physiological impact of a school based sprint interval training (SIT) intervention in replacement of standard physical education (SPE) class on cardio-respiratory fitness (CRF) and glucose homeostasis during the semester following summer vacation. Participants (n=49) were randomly allocated to either intervention (SIT; n=26, aged 16.9 ± 0.3 yrs) or control group who underwent standard physical education (SPE; n=23, aged 16.8 ± 0.6 yrs). CRF (VO₂max) and glucose homeostasis were obtained prior-to and following 7 weeks of SIT exercise. Significant group x time interaction was observed for CRF (P < 0.01) with non-significant trends for fasting insulin (P= 0.08), and HOMA-IR (P=0.06). CRF decreased (P < 0.01) in SPE such that POST intervention CRF was significantly lower (P< 0.05) in SPE. Fasting plasma glucose (P < 0.01), insulin (P< 0.01) and HOMA-IR (P< 0.01) increased significantly amongst SPE. The main finding of the present study is that 7-weeks of SIT exercise is an effective method of maintaining (but not improving) CRF and fasting insulin homeostasis amongst school-going adolescents. SIT exercise demonstrates potential as a time efficient physiological adjunct to standard PE class in order to maintain CRF during the school term.     

Two soluble glycosyltransferases glycosylate less efficiently in vivo than their membrane bound counterparts

Many Golgi glycosyltransferases are type II membrane proteins which are cleaved to produce soluble forms that are released from cells. Cho and Cummings recently reported that a soluble form of alpha1, 3- galactosyltransferase was comparable to its membrane bound counterpart in its ability to galactosylate newly synthesized glycoproteins (Cho,S.K. and Cummings,R.D. (1997) J. Biol. Chem., 272, 13622-13628). To test the generality of their findings, we compared the activities of the full length and soluble forms of two such glycosyltransferases, ss1,4 N-Acetylgalactosaminyltransferase (GM2/GD2/ GA2 synthase; GalNAcT) and beta galactoside alpha2,6 sialyltransferase (alpha2,6-ST; ST6Gal I), for production of their glycoconjugate products in vivo . Unlike the full length form of GalNAcT which produced ganglioside GM2 in transfected cells, soluble GalNAcT did not produce detectable GM2 in vivo even though it possessed in vitro GalNAcT activity comparable to that of full length GalNAcT. When compared with cells expressing full length alpha2,6-ST, cells expressing a soluble form of alpha2,6-ST contained 3-fold higher alpha2,6-ST mRNA levels and secreted 7-fold greater alpha2,6-ST activity as measured in vitro , but in striking contrast contained 2- to 4-fold less of the alpha2,6-linked sialic acid moiety in cellular glycoproteins in vivo . In summary these results suggest that unlike alpha1,3-galactosyltransferase the soluble forms of these two glycosyltransferases are less efficient at glycosylation of membrane proteins and lipids in vivo than their membrane bound counterparts.      

Social stress induced pressure breathing and consequent blood pressure oscillation

A large amplitude blood pressure oscillation occurs during social defeat in a territorial fight between male rats, and during the application of a psychosocial stimulus associated with this defeat. Synchronous recording of blood pressure, intrathoracic pressure and diaphragm activity shows that the blood pressure oscillation coincides with a typical respiratory pattern called 'pressure breathing', during which a strongly positive intrathoracic pressure with expiration can be observed. The expiration was relatively prolonged and accompanied by a rise in blood pressure and a decrease in heart frequency. These alterations outlast the applied social respectively psychosocial stimulations. The results of this study suggest that behaviorally induced pressure breathing is of importance to attentional processes during social stimulation. The contribution to the development of hypertension is discussed.     

Long-term Chikungunya sequelae and quality of life 2.5 years post-acute disease in a prospective cohort in Curaçao

BackgroundLittle is known about the persistence and impact of non-rheumatic symptoms after acute chikungunya disease. We have studied the clinical presentation and long-term impact of rheumatic and non-rheumatic symptoms on health related quality of life (QoL) 2.5 years after disease onset. Additionally, the validity of the Curaçao Long-Term Chikungunya Sequelae (CLTCS) score in classifying disease severity over time was evaluated.Methodology/Principal findingsThis prospective cohort study followed 248 chikungunya patients. Symptoms and SF-36 QoL were evaluated during baseline and follow-up at 2.5 years using questionnaires. Chikungunya disease status was classified using the CLTCS-score. At 2.5 years after disease onset patients were classified as being recovered (43%), mildly (35%) or highly (22%) affected. In comparison to mildly affected, highly affected patients reported the highest prevalence of ongoing rheumatic and non-rheumatic/psychological symptoms, with increased prevalence of arthralgia in the lower extremities (p = .01) and fatigue (p = .049) over time, and higher pain intensity (p < .001). Compared to mildly affected, being highly affected was associated with weakness in the lower extremities (OR: 1.90; CI: 1.29–2.80, p = .001) and worsened physical and mental QoL impairment.ConclusionsPatients are both physically and psychologically affected by rheumatic and non-rheumatic symptoms of long-term chikungunya disease.The CLTCS-score is an easy to use instrument for classifying long-term chikungunya disease severity and impact and can facilitate health care providers in identifying highly affected patients who are prone to develop severe QoL impairment. Highly affected patients are recommended to be treated in a multidisciplinary setting to improve physical and psychological functioning, and QoL.     

Extracellular polymeric substances of the marine fouling diatom amphora rostrata Wm.Sm

Amphora rostrata was grown under continuous illumination at 27°C in batch cultures using f/2 medium. Cell biomass (measured as chllorophyll a and cell counts) reached a maximum on day 7. Thereafter, cell biomass as chl a showed a small decrease. Planktonic('free') and biofilm extracellular polymeric substances (EPS) from the adherent cells of A. rostrata were studied. Both types of EPS were produced during the logarithmic phase of growth. However, production was higher during the stationary growth phase. Enhanced EPS production was associated with nutrient deficient conditions. Planktonic and biofilm EPS were purified by gel filtration using Sephadex G‐200 and ion exchange chromatography using DEAE‐cellulose. Both polymers showed the presence of a single peak. Capillary gas Chromatographie analysis of both planktonic and biofilm EPS showed that fucose (36.7%) and galactose (27.6%) were the most abundant monosaccharides, with small quantities of rhamnose, xylose, arabinose, mannose and glucose. Other chemical analysis showed the presence of sulphate, uronic acids, hexoamines, pyruvate and proteins in both the planktonic and bio‐film EPS. Uronic acid, pyruvate and sulphate together were found to contribute ～50 to 60% (W/W) to the EPS of A. rostrata. Such a high content of non‐sugar components indicates their importance to the diatom in metal binding, desiccation prevention and flexibility.     

Diastolic time fraction as a determinant of subendocardial perfusion

Diastolic time fraction (DTF) has been recognized as an important determinant for subendocardial perfusion, but microsphere studies in which DTF was the independent variable are practically absent. In 21 anesthetized goats, the left coronary main stem was artificially perfused at controlled pressure. DTF was varied by pacing the heart, vagus stimulation, or administration of dobutamine. Regional coronary flow was measured with fluorescent microspheres under full adenosine dilation. Perfusion pressure (P(c)) was defined as mean coronary arterial pressure minus minimal left ventricular pressure. Regional flow conductances (flow/P(c)) were as follows: for the subendocardium, C(endo) = -0.103 + 0.197 DTF + 0.00074 P(c) (P < 0.001); for the midmyocardium, conductance = -0.048 + 0.126 DTF + 0.00049 P(c) (P < 0.001); and for the subepicardium, C(epi) was not significant. C(endo)-DTF relations demonstrated a finite value for DTF at which flow is zero, implying that, at physiological pressures, systolic subendocardial flow limitation extends into diastole. The DTF corresponding to an equal conductance in subendocardium and subepicardium (DTF1) was inversely related to P(c): DTF1 = 0.78 - 0.003 P(c) (P < 0.01). When heart rate and P(c) were held constant and dobutamine was administered (5 goats), contractility doubled and DTF increased by 39%, resulting in an increase of C(endo) of 40%. It is concluded that 1) DTF is a determinant of subendocardial perfusion, 2) systolic compression exerts a flow-limiting effect into diastole, and 3) corresponding to clinical findings on inducible ischemia we predict that, under hyperemic conditions, C(endo) < C(epi) if P(c) is lower than approximately 75% of a normal aortic pressure and heart rate >80 beats/min.     

No evidence for long‐term effects of reproductive effort on parasite prevalence in great tits Parus major

Allocation of resources between the life history traits reproduction and parasite defence are expected because both are energetically costly. Experimental evidence for such allocation has been found in short‐term effects of reproduction on parasite prevalence or immune function. However, there is increasing evidence for long‐term negative effects of reproductive effort on individuals. This study investigates whether long‐term effects of reproductive effort on parasite prevalence exist. Brood sizes of great tits Parus major were experimentally altered in one breeding season and in the subsequent breeding season the prevalence of three parasites types (blood parasites, ticks and fleas) on the surviving parents were investigated. We detected no long‐term effects of brood size manipulation on the prevalence of parasites in the next year and therefore provide no evidence for inter‐seasonal effects of reproductive effort on parasite prevalence. The post hoc level of statistical power was reasonable for effects on blood parasite and flea prevalence, but low for effects on tick prevalence.     

Transcriptomic response to differentiation induction

Background  

Microarrays used for gene expression studies yield large amounts of data. The processing of such data typically leads to lists of differentially-regulated genes. A common terminal data analysis step is to map pathways of potentially interrelated genes.