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Fetal growth restriction (FGR) and prematurity are associated with high risk of brain injury and long-term neurological deficits. FGR infants born preterm are commonly exposed to mechanical ventilation, but it is not known whether ventilation differentially induces brain pathology in FGR infants compared with appropriate for gestational age (AGA) infants. We investigated markers of neuropathology in moderate-to late-preterm FGR lambs, compared with AGA lambs, delivered by caesarean birth and ventilated under standard neonatal conditions for 24 h. FGR was induced by single umbilical artery ligation in fetal sheep at 88-day gestation (term, 150 days). At 125-day gestation, FGR and AGA lambs were delivered, dried, intubated, and commenced on noninjurious ventilation, with surfactant administration at 10 min. A group of unventilated FGR and AGA lambs at the same gestation was also examined. Over 24 h, circulating pH, PO2, and lactate levels were similar between groups. Ventilated FGR lambs had lower cerebral blood flow compared with AGA lambs (P = 0.01). The brain of ventilated FGR lambs showed neuropathology compared with unventilated FGR, and unventilated and ventilated AGA lambs, with increased apoptosis (caspase-3), blood-brain barrier dysfunction (albumin extravasation), activated microglia (Iba-1), and increased expression of cellular oxidative stress (4-hydroxynonenal). The neuropathologies seen in the ventilated FGR brain were most pronounced in the periventricular and subcortical white matter but also evident in the subventricular zone, cortical gray matter, and hippocampus. Ventilation of preterm FGR lambs increased brain injury compared with AGA preterm lambs and unventilated FGR lambs, mediated via increased vascular permeability, neuroinflammation and oxidative stress.Copyright © 2018 the American Physiological Society.

Fetal growth restriction (FGR) and prematurity are associated with high risk of brain injury and long-term neurological deficits. FGR infants born preterm are commonly exposed to mechanical ventilation, but it is not known whether ventilation differentially induces brain pathology in FGR infants compared with appropriate for gestational age (AGA) infants. We investigated markers of neuropathology in moderate-to late-preterm FGR lambs, compared with AGA lambs, delivered by caesarean birth and ventilated under standard neonatal conditions for 24 h. FGR was induced by single umbilical artery ligation in fetal sheep at 88-day gestation (term, 150 days). At 125-day gestation, FGR and AGA lambs were delivered, dried, intubated, and commenced on noninjurious ventilation, with surfactant administration at 10 min. A group of unventilated FGR and AGA lambs at the same gestation was also examined. Over 24 h, circulating pH, PO2, and lactate levels were similar between groups. Ventilated FGR lambs had lower cerebral blood flow compared with AGA lambs (P = 0.01). The brain of ventilated FGR lambs showed neuropathology compared with unventilated FGR, and unventilated and ventilated AGA lambs, with increased apoptosis (caspase-3), blood-brain barrier dysfunction (albumin extravasation), activated microglia (Iba-1), and increased expression of cellular oxidative stress (4-hydroxynonenal). The neuropathologies seen in the ventilated FGR brain were most pronounced in the periventricular and subcortical white matter but also evident in the subventricular zone, cortical gray matter, and hippocampus. Ventilation of preterm FGR lambs increased brain injury compared with AGA preterm lambs and unventilated FGR lambs, mediated via increased vascular permeability, neuroinflammation and oxidative stress.Copyright © 2018 the American Physiological Society.

Previous studies that utilized sodium lactate infusion did not use resistance exercise protocol or analyzed muscle biopsies, or performed sex specific analysis. Aim: We initiated a project where resistance exercise was performed with low and high levels of lactate, acquired by venous lactate infusion where the specific aim of this study was to investigate and chart the physiological characteristics of sodium lactate infusion during a bout of resistance exercise on whole group level and sexes separated Method: A randomized, placebo controlled, cross-over design was implemented where male (n = 8) and female (n = 8) subjects accustomed to resistance exercise visited the laboratory three times for preliminary testing and training familiarization. In the following two experimental trials subjects arrived in an overnight fasted state. A resting state muscle biopsy was extracted from m. vastus lateralis and repeated blood samples were initiated which followed by 20 minute of baseline infusion of either infusate in resting state at 0.05 mmol/kg/min infusion rate with additional bolus doses during subsequent exercise. Following a brief warm up, unilateral knee-extensions (6 x 8-10 reps at 75% of 1-RM) were performered with or without venous infusion of sodium lactate, with volume matched saline as control. Exercise load and volume were matched between trials. Four additional biopsies were extracted at post-exercise, recovery period, and 24-hour post-exercise. Results: Sodium lactate infusion vs saline infusion respectively during resistance exercise yielded significantly higher blood lactate with sodium lactate (6.78 ± 0.33 mmol/l vs 2.99 ± 0.17 mmol/l), plasma lactate (8.86 ± 0.39 mmol/l vs 4.39 ± 0.22 mmol/l), blood sodium (143 ± 0.4 mmol/l vs 142 ± 0.3 mmol/l), blood pH (7.42 ± 0.01 vs 7.34 ± 0.01), but lower blood potassium (3.9 ± 0.1 mmol/l vs 4.2 ± 0.1 mmol/l), all immediately following exercise. Sodium lactate infusion elicited main effect of trials and muscle lacta, Tidigare studier som använt natriumlaktat infusion använde inte styrketräningsprotokoll, eller analyserade muskelbiopsier eller utförde könsspecifika analyser. Syfte och frågeställningar: Vi initierade ett projekt där styrketräning utfördes med låga eller höga nivåer av laktat som erhölls genom venös natriumlaktat infusion med det specifika syftet att undersöka och kartlägga fysiologisk karakteristiska av naturiumlaktat infusion under styrketräningsövning på helgrupps- och könsseparerad nivå. Följande frågeställningar inrättades; hur påverkar natriumlaktat infusion under styrketräning helblod- och plasma laktat, glukos, natrium, kalium, plasma volym genom hemoglobin och hematokrit, blod pH, muskellaktat- och muskel pH samt om skillnader i respons finns efter att könsspecifika analyser utförts på dessa variabler. Metod: En randomiserad, placebokontrollerad cross-over design implementerades där styrketräningsvana män (n = 8) och kvinnor (n = 8) besökte laboratoriet tre gånger för preliminäraför tester och träningsfamiliarisering. I efterföljande två experimentella försök anlände försökspersonerna i ett över nattligt fastande tillstånd. En baslinje biopsi extraherades från m. vastus lateralis och repeterade blodprover initierades med efterföljande 20 minuter av baslinje infusion av endera infusat i vilotillstånd med 0.05 mmol/kg/min infusionshastighet med ytterligare bolusdoser under efterföljande träning. Efter en kort uppvärmning utfördes unilaterala knäextensioner (6 x 8-10 reps vid 75% av 1-RM) med eller utan venös infusion av natrium laktat, med volymmatchande saltlösning som kontroll. Träningsbelastning och volym matchades mellan försök. Ytterligare fyra biopsier extraherades vid efter-träning, återhämtningsperiod, och efter 24 timmar. Resultat: Natriumlaktat respektive saltlösnings infusion under styrketräning gav signifikant högre blodlaktat med natriumlaktat infusion (6.78 ± 0.33 mmol/l mot 2.99 ± 0.17 mmol/l), plasmalaktat (8.86 ± 0.39 mmol/l mot 4.39 ± 0.22, Potential sex differences in the molecular response to resistance exercise with lactate infusion

Previous studies that utilized sodium lactate infusion did not use resistance exercise protocol or analyzed muscle biopsies, or performed sex specific analysis. Aim: We initiated a project where resistance exercise was performed with low and high levels of lactate, acquired by venous lactate infusion where the specific aim of this study was to investigate and chart the physiological characteristics of sodium lactate infusion during a bout of resistance exercise on whole group level and sexes separated Method: A randomized, placebo controlled, cross-over design was implemented where male (n = 8) and female (n = 8) subjects accustomed to resistance exercise visited the laboratory three times for preliminary testing and training familiarization. In the following two experimental trials subjects arrived in an overnight fasted state. A resting state muscle biopsy was extracted from m. vastus lateralis and repeated blood samples were initiated which followed by 20 minute of baseline infusion of either infusate in resting state at 0.05 mmol/kg/min infusion rate with additional bolus doses during subsequent exercise. Following a brief warm up, unilateral knee-extensions (6 x 8-10 reps at 75% of 1-RM) were performered with or without venous infusion of sodium lactate, with volume matched saline as control. Exercise load and volume were matched between trials. Four additional biopsies were extracted at post-exercise, recovery period, and 24-hour post-exercise. Results: Sodium lactate infusion vs saline infusion respectively during resistance exercise yielded significantly higher blood lactate with sodium lactate (6.78 ± 0.33 mmol/l vs 2.99 ± 0.17 mmol/l), plasma lactate (8.86 ± 0.39 mmol/l vs 4.39 ± 0.22 mmol/l), blood sodium (143 ± 0.4 mmol/l vs 142 ± 0.3 mmol/l), blood pH (7.42 ± 0.01 vs 7.34 ± 0.01), but lower blood potassium (3.9 ± 0.1 mmol/l vs 4.2 ± 0.1 mmol/l), all immediately following exercise. Sodium lactate infusion elicited main effect of trials and muscle lacta, Tidigare studier som använt natriumlaktat infusion använde inte styrketräningsprotokoll, eller analyserade muskelbiopsier eller utförde könsspecifika analyser. Syfte och frågeställningar: Vi initierade ett projekt där styrketräning utfördes med låga eller höga nivåer av laktat som erhölls genom venös natriumlaktat infusion med det specifika syftet att undersöka och kartlägga fysiologisk karakteristiska av naturiumlaktat infusion under styrketräningsövning på helgrupps- och könsseparerad nivå. Följande frågeställningar inrättades; hur påverkar natriumlaktat infusion under styrketräning helblod- och plasma laktat, glukos, natrium, kalium, plasma volym genom hemoglobin och hematokrit, blod pH, muskellaktat- och muskel pH samt om skillnader i respons finns efter att könsspecifika analyser utförts på dessa variabler. Metod: En randomiserad, placebokontrollerad cross-over design implementerades där styrketräningsvana män (n = 8) och kvinnor (n = 8) besökte laboratoriet tre gånger för preliminäraför tester och träningsfamiliarisering. I efterföljande två experimentella försök anlände försökspersonerna i ett över nattligt fastande tillstånd. En baslinje biopsi extraherades från m. vastus lateralis och repeterade blodprover initierades med efterföljande 20 minuter av baslinje infusion av endera infusat i vilotillstånd med 0.05 mmol/kg/min infusionshastighet med ytterligare bolusdoser under efterföljande träning. Efter en kort uppvärmning utfördes unilaterala knäextensioner (6 x 8-10 reps vid 75% av 1-RM) med eller utan venös infusion av natrium laktat, med volymmatchande saltlösning som kontroll. Träningsbelastning och volym matchades mellan försök. Ytterligare fyra biopsier extraherades vid efter-träning, återhämtningsperiod, och efter 24 timmar. Resultat: Natriumlaktat respektive saltlösnings infusion under styrketräning gav signifikant högre blodlaktat med natriumlaktat infusion (6.78 ± 0.33 mmol/l mot 2.99 ± 0.17 mmol/l), plasmalaktat (8.86 ± 0.39 mmol/l mot 4.39 ± 0.22, Potential sex differences in the molecular response to resistance exercise with lactate infusion

Background: Glasgow coma score (GCS) less than 9 is often used to decide to intubate in the emergency department (ED). We analyzed suspected GHB intoxications presenting to our ED-network, with GCS < 9 and compared clinical features of intubated (INT) and not intubated (non-INT) patients. Method(s): Retrospective analysis of presentations with suspected GHB intoxication (Jan 2013-Jan 2017). Data included demographics, co-ingestants, ethanol intake, physiological and blood gas parameters on presentation, lowest GCS, intubation status, and length of stay (LOS). Continuous data reported as median (range) or mean (95% CI). Result(s): There were 332 suspected GHB presentations (280 non-INTand 52 intubated). GCS < 9 documented in 78 non-INT and 51 INT patients. Median age was 25 years for both cohorts. GHB was suspected on presentation (non-INT 88 vs INT 94%) with similar incidences of poly-drug (40 vs 39%), amphetamine (30 vs 37%), and ethanol co-ingestion (32 vs 33%), respectively. Median serum-ethanol concentration: non-INT 0.015 vs INT 0.02 mg/dL. Initial venous blood gases showed similar mean serum pH: non-INT 7.32 (95% CI 7.31-7.34) vs INT 7.30 (95% CI 7.28-7.32) and mean pCO2 non-INT 50.5 mmHg (95% CI 48-52) vs INT50(95% CI 47-51). Median lowest GCS for non-INT 7 (3-8)vsINT 3 (3-8), p < 0.0001. Presenting pulse and BP were similar. Median time to intubation from ED presentation was 22 min and those intubated were vomiting more frequently (23 vs 13%, p = 0.15, OR 2.1, 95% CI 0.83-5.3) and more commonly had a subsequent cranialCT (86 vs 9%, OR 64, 95% CI 21-194). Cranial CTs were all normal. Median time to extubation was 7 h (2.5-40) vs non-INT patient time to GCS 15 2.5 h (0.5-16), p < 0.0001. Median total LOS: INT 24 h (4-123) vs non-INT 5.0 h (0.5-84), p < 0.0001. Median peak propofol infusion rate while intubated was 200 mg/h (50-500). Conclusion(s): GCS was the only significantly different clinical parameter on presentation between intubated and non-intubated pa

Background: Glasgow coma score (GCS) less than 9 is often used to decide to intubate in the emergency department (ED). We analyzed suspected GHB intoxications presenting to our ED-network, with GCS < 9 and compared clinical features of intubated (INT) and not intubated (non-INT) patients. Method(s): Retrospective analysis of presentations with suspected GHB intoxication (Jan 2013-Jan 2017). Data included demographics, co-ingestants, ethanol intake, physiological and blood gas parameters on presentation, lowest GCS, intubation status, and length of stay (LOS). Continuous data reported as median (range) or mean (95% CI). Result(s): There were 332 suspected GHB presentations (280 non-INTand 52 intubated). GCS < 9 documented in 78 non-INT and 51 INT patients. Median age was 25 years for both cohorts. GHB was suspected on presentation (non-INT 88 vs INT 94%) with similar incidences of poly-drug (40 vs 39%), amphetamine (30 vs 37%), and ethanol co-ingestion (32 vs 33%), respectively. Median serum-ethanol concentration: non-INT 0.015 vs INT 0.02 mg/dL. Initial venous blood gases showed similar mean serum pH: non-INT 7.32 (95% CI 7.31-7.34) vs INT 7.30 (95% CI 7.28-7.32) and mean pCO2 non-INT 50.5 mmHg (95% CI 48-52) vs INT50(95% CI 47-51). Median lowest GCS for non-INT 7 (3-8)vsINT 3 (3-8), p < 0.0001. Presenting pulse and BP were similar. Median time to intubation from ED presentation was 22 min and those intubated were vomiting more frequently (23 vs 13%, p = 0.15, OR 2.1, 95% CI 0.83-5.3) and more commonly had a subsequent cranialCT (86 vs 9%, OR 64, 95% CI 21-194). Cranial CTs were all normal. Median time to extubation was 7 h (2.5-40) vs non-INT patient time to GCS 15 2.5 h (0.5-16), p < 0.0001. Median total LOS: INT 24 h (4-123) vs non-INT 5.0 h (0.5-84), p < 0.0001. Median peak propofol infusion rate while intubated was 200 mg/h (50-500). Conclusion(s): GCS was the only significantly different clinical parameter on presentation between intubated and non-intubated pa

Tracking physiological parameters in different organs within the same organism simultaneously and in real time can provide an outstanding representation of the organism’s physiological status. The state-of-the-art technique of using encapsulated fluorescent molecular probes (microencapsulated biomarkers) is a unique tool that can serve as a platform for the development of new methods to obtain in vivo physiological measurements and is applicable to a broad range of organisms. Here, we describe a novel technique to monitor the pH of blood inside the gill capillaries and interstitial fluid of muscles by using microencapsulated biomarkers in a zebrafish model. The functionality of the proposed technique is shown by the identification of acidification under anesthesia-induced coma and after death. The pH in muscles reacts to hypoxia faster than that in the gill bloodstream, which makes both parameters applicable as markers of either local or bodily reactions.

Background:Cardiovascular dysfunction at birth may underlie poor outcomes after fetal growth restriction (FGR) in neonates. We compared the cardiovascular transition between FGR and appropriately grown (AG) preterm lambs and examined possible mechanisms underlying any cardiovascular dysfunction in FGR lambs. Method(s):FGR was induced in ewes bearing twins at 0.7 gestation; the twin was used as an internal control (AG). At 0.8 gestation, lambs were delivered and either euthanized with their arteries isolated for in vitro wire myography, or ventilated for 2 h. At 60 min, inhaled nitric oxide (iNO) was administered in a subgroup for 30 min. Molecular assessment of the nitric oxide (NO) pathway within lung tissue was conducted. Result(s):FGR lambs had lower left ventricular output and cerebral blood flow (CBF) and higher systemic vascular resistance compared with AG lambs. INO administration to FGR lambs rapidly improved cardiovascular and systemic hemodynamics but resulted in decreased CBF in AG lambs. Isolated arteries from FGR lambs showed impaired sensitivity to NO donors, but enhanced vasodilation to Sildenafil and Sodium nitroprusside, and altered expression of components of the NO pathway. Conclusion(s):Cardiovascular dysfunction at birth may underlie the increased morbidity and mortality observed in preterm FGR newborns. Impaired NO signaling likely underlies the abnormal vascular reactivity.Copyright © 2016 International Pediatric Research Foundation, Inc.

Background:Cardiovascular dysfunction at birth may underlie poor outcomes after fetal growth restriction (FGR) in neonates. We compared the cardiovascular transition between FGR and appropriately grown (AG) preterm lambs and examined possible mechanisms underlying any cardiovascular dysfunction in FGR lambs. Method(s):FGR was induced in ewes bearing twins at 0.7 gestation; the twin was used as an internal control (AG). At 0.8 gestation, lambs were delivered and either euthanized with their arteries isolated for in vitro wire myography, or ventilated for 2 h. At 60 min, inhaled nitric oxide (iNO) was administered in a subgroup for 30 min. Molecular assessment of the nitric oxide (NO) pathway within lung tissue was conducted. Result(s):FGR lambs had lower left ventricular output and cerebral blood flow (CBF) and higher systemic vascular resistance compared with AG lambs. INO administration to FGR lambs rapidly improved cardiovascular and systemic hemodynamics but resulted in decreased CBF in AG lambs. Isolated arteries from FGR lambs showed impaired sensitivity to NO donors, but enhanced vasodilation to Sildenafil and Sodium nitroprusside, and altered expression of components of the NO pathway. Conclusion(s):Cardiovascular dysfunction at birth may underlie the increased morbidity and mortality observed in preterm FGR newborns. Impaired NO signaling likely underlies the abnormal vascular reactivity.Copyright © 2016 International Pediatric Research Foundation, Inc.

Vampire bats, Desmodus rotundus, must maximize their feeding cycle of one blood meal per day by being efficient in the stalking and acquisition of their food. Riskin and Hermanson documented the running gait of the common vampire bat and observed they were efficient at running speeds, using longer stride lengths and thus decreased stride frequency. We obtained preliminary data on gait maintained for up to 10 minutes on a moving treadmill belt at speeds ranging from 0.23 to 0.74 m/s, which spanned a range from walking to running gaits. Bats tended to transition between gaits at about 0.40 m/s. Fourteen bats were studied and included four that were able to walk or run for 10 minutes. There was no significant change in either stride duration or frequency associated with an increase in speed. We estimated O2 consumption and CO2 production both before and 5 minutes after exercise, and found that O2 consumption increased 1 minute and 5 minutes after exercise. CO2 levels increased significantly 1 minute after exercise, but tended back towards pre-exercise level 5 minutes after exercise. Two bats were tested for blood O2, CO2 and pH levels. Interestingly, pH levels fell from 7.3 to about 7.0, indicating lactate accumulation.

It was hypothesized that an oscillation of tissue oxygen index (TOI) determined by near-infrared spectroscopy during recovery from exercise occurs due to feedback control of adenosine triphosphate and that frequency of the oscillation is affected by blood pH. In order to examine these hypotheses, we aimed 1) to determine whether there is an oscillation of TOI during recovery from exercise and 2) to determine the effect of blood pH on frequency of the oscillation of TOI. Three exercises were performed with exercise intensities of 30 % and 70 % peak oxygen uptake (Vo2peak) for 12 min and with exercise intensity of 70 % Vo2peak for 30 s. TOI during recovery from the exercise was analyzed by fast Fourier transform in order to obtain power spectra density (PSD). There was a significant difference in the frequency at which maximal PSD of TOI appeared (Fmax) between the exercises with 70 % Vo2peak for 12 min (0.0039±0 Hz) and for 30 s (0.0061±0.0028 Hz). However, there was no significant difference in Fmax between the exercises with 30 % (0.0043±0.0013 Hz) and with 70 % Vo2peak for 12 min despite differences in blood pH and blood lactate from the warmed fingertips. It is concluded that there was an oscillation in TOI during recovery from the three exercises. It was not clearly shown that there was an effect of blood pH on Fmax.

It was hypothesized that an oscillation of tissue oxygen index (TOI) determined by near-infrared spectroscopy during recovery from exercise occurs due to feedback control of adenosine triphosphate and that frequency of the oscillation is affected by blood pH. In order to examine these hypotheses, we aimed 1) to determine whether there is an oscillation of TOI during recovery from exercise and 2) to determine the effect of blood pH on frequency of the oscillation of TOI. Three exercises were performed with exercise intensities of 30 % and 70 % peak oxygen uptake (Vo2peak) for 12 min and with exercise intensity of 70 % Vo2peak for 30 s. TOI during recovery from the exercise was analyzed by fast Fourier transform in order to obtain power spectra density (PSD). There was a significant difference in the frequency at which maximal PSD of TOI appeared (Fmax) between the exercises with 70 % Vo2peak for 12 min (0.0039±0 Hz) and for 30 s (0.0061±0.0028 Hz). However, there was no significant difference in Fmax between the exercises with 30 % (0.0043±0.0013 Hz) and with 70 % Vo2peak for 12 min despite differences in blood pH and blood lactate from the warmed fingertips. It is concluded that there was an oscillation in TOI during recovery from the three exercises. It was not clearly shown that there was an effect of blood pH on Fmax.

It was hypothesized that an oscillation of tissue oxygen index (TOI) determined by near-infrared spectroscopy during recovery from exercise occurs due to feedback control of adenosine triphosphate and that frequency of the oscillation is affected by blood pH. In order to examine these hypotheses, we aimed 1) to determine whether there is an oscillation of TOI during recovery from exercise and 2) to determine the effect of blood pH on frequency of the oscillation of TOI. Three exercises were performed with exercise intensities of 30 % and 70 % peak oxygen uptake (Vo2peak) for 12 min and with exercise intensity of 70 % Vo2peak for 30 s. TOI during recovery from the exercise was analyzed by fast Fourier transform in order to obtain power spectra density (PSD). There was a significant difference in the frequency at which maximal PSD of TOI appeared (Fmax) between the exercises with 70 % Vo2peak for 12 min (0.0039±0 Hz) and for 30 s (0.0061±0.0028 Hz). However, there was no significant difference in Fmax between the exercises with 30 % (0.0043±0.0013 Hz) and with 70 % Vo2peak for 12 min despite differences in blood pH and blood lactate from the warmed fingertips. It is concluded that there was an oscillation in TOI during recovery from the three exercises. It was not clearly shown that there was an effect of blood pH on Fmax.

It was hypothesized that an oscillation of tissue oxygen index (TOI) determined by near-infrared spectroscopy during recovery from exercise occurs due to feedback control of adenosine triphosphate and that frequency of the oscillation is affected by blood pH. In order to examine these hypotheses, we aimed 1) to determine whether there is an oscillation of TOI during recovery from exercise and 2) to determine the effect of blood pH on frequency of the oscillation of TOI. Three exercises were performed with exercise intensities of 30 % and 70 % peak oxygen uptake (Vo2peak) for 12 min and with exercise intensity of 70 % Vo2peak for 30 s. TOI during recovery from the exercise was analyzed by fast Fourier transform in order to obtain power spectra density (PSD). There was a significant difference in the frequency at which maximal PSD of TOI appeared (Fmax) between the exercises with 70 % Vo2peak for 12 min (0.0039±0 Hz) and for 30 s (0.0061±0.0028 Hz). However, there was no significant difference in Fmax between the exercises with 30 % (0.0043±0.0013 Hz) and with 70 % Vo2peak for 12 min despite differences in blood pH and blood lactate from the warmed fingertips. It is concluded that there was an oscillation in TOI during recovery from the three exercises. It was not clearly shown that there was an effect of blood pH on Fmax.

Renal tubular acidosis is a common cause of normal anion gap metabolic acidosis but these disorders can be easily missed or misdiagnosed. We highlight the approach to assessing renal tubular acidosis by discussing a case study with a temporal data set collected over more than 5 weeks. We highlight the principles and the necessary information required for a diagnosis of classic distal renal tubular acidosis. We also briefly review several aspects of type 1 renal tubular acidosis related to autoimmune disease, drugs and thyroid disorders. © 2013 Royal Australasian College of Physicians.

Renal tubular acidosis is a common cause of normal anion gap metabolic acidosis but these disorders can be easily missed or misdiagnosed. We highlight the approach to assessing renal tubular acidosis by discussing a case study with a temporal data set collected over more than 5 weeks. We highlight the principles and the necessary information required for a diagnosis of classic distal renal tubular acidosis. We also briefly review several aspects of type 1 renal tubular acidosis related to autoimmune disease, drugs and thyroid disorders. © 2013 Royal Australasian College of Physicians.

The literature suggests that up to 19% of umbilical cord blood samples are invalid. Accordingly, it has been proposed that blood should be universally collected from both vessels. We prospectively collected paired arterial and venous blood to examine whether our centre, where staff were experienced in single vessel collection, was more accurate. Of 289 paired samples, 53 (18.3%) were considered invalid. Despite this significant error rate, we propose that routinely, only arterial sampling is needed and that an additional venous sample need only be taken to validate samples in cases of pH < 7.15, a difficult delivery or a non-vigorous baby.

The literature suggests that up to 19% of umbilical cord blood samples are invalid. Accordingly, it has been proposed that blood should be universally collected from both vessels. We prospectively collected paired arterial and venous blood to examine whether our centre, where staff were experienced in single vessel collection, was more accurate. Of 289 paired samples, 53 (18.3%) were considered invalid. Despite this significant error rate, we propose that routinely, only arterial sampling is needed and that an additional venous sample need only be taken to validate samples in cases of pH < 7.15, a difficult delivery or a non-vigorous baby.

To determine that whether arterial carbon dioxide (PaCO2) affects ventilation (VE) during recovery from impulse-like exercises of various intensities, subjects performed four impulse-like tests with different workloads. Each test consisted of a 20-sec impulse-like exercise at 80 rpm and 60-min recovery. Blood samples were collected at rest and during recovery to measure blood ions and gases. VE was measured continuously during rest, exercise and recovery periods. A significant curvilinear relationship was observed between VE and pH during recovery from the 300 and 400 watts tests in all subjects. VE was elevated during recovery from the 100 watts test despite no change in any of the humoral factors. Arterialized carbon dioxide (PaCO2) kinetics showed fluctuation, being increased at 1 min and decreased at 5 min during recovery, and this fluctuation was more enhanced with increase in exercise intensity. There was a significant relationship between VE and PaCO2 during recovery from the 300 and 400 watts tests in all subjects. The results of the present study demonstrate that pH and neural factors drive VE during recovery from impulse-like exercise and that fluctuation in PaCO2 controls VE as a feedback loop and this feedback function is more enhanced as the work intensity increases.

To determine that whether arterial carbon dioxide (PaCO2) affects ventilation (VE) during recovery from impulse-like exercises of various intensities, subjects performed four impulse-like tests with different workloads. Each test consisted of a 20-sec impulse-like exercise at 80 rpm and 60-min recovery. Blood samples were collected at rest and during recovery to measure blood ions and gases. VE was measured continuously during rest, exercise and recovery periods. A significant curvilinear relationship was observed between VE and pH during recovery from the 300 and 400 watts tests in all subjects. VE was elevated during recovery from the 100 watts test despite no change in any of the humoral factors. Arterialized carbon dioxide (PaCO2) kinetics showed fluctuation, being increased at 1 min and decreased at 5 min during recovery, and this fluctuation was more enhanced with increase in exercise intensity. There was a significant relationship between VE and PaCO2 during recovery from the 300 and 400 watts tests in all subjects. The results of the present study demonstrate that pH and neural factors drive VE during recovery from impulse-like exercise and that fluctuation in PaCO2 controls VE as a feedback loop and this feedback function is more enhanced as the work intensity increases.

To determine that whether arterial carbon dioxide (PaCO2) affects ventilation (VE) during recovery from impulse-like exercises of various intensities, subjects performed four impulse-like tests with different workloads. Each test consisted of a 20-sec impulse-like exercise at 80 rpm and 60-min recovery. Blood samples were collected at rest and during recovery to measure blood ions and gases. VE was measured continuously during rest, exercise and recovery periods. A significant curvilinear relationship was observed between VE and pH during recovery from the 300 and 400 watts tests in all subjects. VE was elevated during recovery from the 100 watts test despite no change in any of the humoral factors. Arterialized carbon dioxide (PaCO2) kinetics showed fluctuation, being increased at 1 min and decreased at 5 min during recovery, and this fluctuation was more enhanced with increase in exercise intensity. There was a significant relationship between VE and PaCO2 during recovery from the 300 and 400 watts tests in all subjects. The results of the present study demonstrate that pH and neural factors drive VE during recovery from impulse-like exercise and that fluctuation in PaCO2 controls VE as a feedback loop and this feedback function is more enhanced as the work intensity increases.

To determine that whether arterial carbon dioxide (PaCO2) affects ventilation (VE) during recovery from impulse-like exercises of various intensities, subjects performed four impulse-like tests with different workloads. Each test consisted of a 20-sec impulse-like exercise at 80 rpm and 60-min recovery. Blood samples were collected at rest and during recovery to measure blood ions and gases. VE was measured continuously during rest, exercise and recovery periods. A significant curvilinear relationship was observed between VE and pH during recovery from the 300 and 400 watts tests in all subjects. VE was elevated during recovery from the 100 watts test despite no change in any of the humoral factors. Arterialized carbon dioxide (PaCO2) kinetics showed fluctuation, being increased at 1 min and decreased at 5 min during recovery, and this fluctuation was more enhanced with increase in exercise intensity. There was a significant relationship between VE and PaCO2 during recovery from the 300 and 400 watts tests in all subjects. The results of the present study demonstrate that pH and neural factors drive VE during recovery from impulse-like exercise and that fluctuation in PaCO2 controls VE as a feedback loop and this feedback function is more enhanced as the work intensity increases.

The objective of this work was to examine the effect of heat stress on glucose and pH values in blood of high-yielding dairy cows in the early stage of lactation, as well as to determine whether the changes in these parameters are interdependent under such conditions. An experiment was performed on high-yielding dairy cows during the summer and the spring periods. Forty cows were selected, twenty each for the two periods under investigation. In the course of the experiment, the temperature humidity index (THI) was determined for the entire period of investigations, and then also the average daily THI, nightmorning THI (average value of hourly THI measured from 22h on the previous day until 10h of the current day), as well as the day-night THI (average value of hourly THI measured during the period from 10h to 22h of the current day). The pH and glucose concentration were determined in blood samples taken in the morning and afternoon of days 30, 60, and 90 of lactation during the spring and summer periods of the investigations. Based on the results for the THI, it was established that the animals were not exposed to the effect of extreme heat stress during the spring period of investigations, while they were periodically exposed to moderate but also extreme heat stress during the summer, in particular in the afternoon hours. It can be concluded from the results obtained for the blood pH that the cows were in respiratory alkalosis during the summer in the morning and afternoon hours on day 30, in the afternoon hours of days 60 and 90 of lactation, as well as in the afternoon on day 90 of lactation during the spring period of investigations. During the summer period, there were no statistically significant differences between the pH value determined in the morning and afternoon hours on day 30 of lactation, while the pH value was significantly higher in the afternoon hours than in the morning hours on days 60 and 90 of lactation. There were no significant differences b, Cilj ovog istraživanja je bio da se ispita uticaj toplotnog stresa na vrednosti glikemije i pH krvi kod visokomlečnih krava u ranoj fazi laktacije, kao i da se utvrdi da li su promene ovih parametara u takvim uslovima međusobno zavisne. Ogled je izveden na visokomlečnim kravama tokom leta i proleća. Odabrano je četrdeset krava, po dvadeset za oba perioda ispitivanja. Tokom ogleda računati su satni toplotni indeksi (THI) za ceo period ispitivanja, a zatim i prosečan dnevni THI, noćnojutarnji THI (prosečna vrednost satnih THI izmerenih u periodu od 22h prethodnog dana do 10h ujutro tekućeg dana), kao i dnevnovečernji THI (prosečna vrednost satnih THI izmerenih u periodu od 10 h do 22 h tekućeg dana). U uzorcima krvi uzetim ujutru i posle podne 30, 60. i 90. dana laktacije tokom prolećnog i letnjeg perioda ispitivanja određivan je pH i koncentracija glukoze. Na osnovu rezultata za THI utvrđeno je da životinje u prolećnom periodu ispitivanja nisu bile izložene delovanju izrazitog toplotnog stresa, dok su tokom leta bile periodič no izložene umerenom, ali i izrazitom toplotnom stresu, posebno u poslepodnevnim satima. Iz dobijenih rezultata za pH krvi se može zaključiti da su krave tokom leta bile u respiratornoj alkalozi 30. dana u jutarnjim i popodnevnim, a 60. i 90. dana laktacije u popodnevnim satima, kao i 90. dana laktacije posle podne tokom prolećnog perioda ispitivanja. Tokom leta nije bilo statistički značajne razlike između pH vrednosti određene u jutarnjim i popodnevnim satima 30. dana laktacije, dok je 60. i 90. dana laktacije popodnevna vrednost za pH bila značajno veća u odnosu na jutarnju. Nije bilo značajnih razlika između prosečnih vrednosti glikemija tokom prolećnog perioda ispitivanja. Tokom leta prosečne popodnevne vrednosti glikemija 60. i 90. dana laktacije bile su značajno niže u odnosu na jutarnje. Glikemije izmerene 90. dana bile su statistički značajno niže od glikemija 30. i 60. dana laktacije, kako jutarnje tako i poslepodnevne. Glikemija je 90

The objective of this work was to examine the effect of heat stress on glucose and pH values in blood of high-yielding dairy cows in the early stage of lactation, as well as to determine whether the changes in these parameters are interdependent under such conditions. An experiment was performed on high-yielding dairy cows during the summer and the spring periods. Forty cows were selected, twenty each for the two periods under investigation. In the course of the experiment, the temperature humidity index (THI) was determined for the entire period of investigations, and then also the average daily THI, nightmorning THI (average value of hourly THI measured from 22h on the previous day until 10h of the current day), as well as the day-night THI (average value of hourly THI measured during the period from 10h to 22h of the current day). The pH and glucose concentration were determined in blood samples taken in the morning and afternoon of days 30, 60, and 90 of lactation during the spring and summer periods of the investigations. Based on the results for the THI, it was established that the animals were not exposed to the effect of extreme heat stress during the spring period of investigations, while they were periodically exposed to moderate but also extreme heat stress during the summer, in particular in the afternoon hours. It can be concluded from the results obtained for the blood pH that the cows were in respiratory alkalosis during the summer in the morning and afternoon hours on day 30, in the afternoon hours of days 60 and 90 of lactation, as well as in the afternoon on day 90 of lactation during the spring period of investigations. During the summer period, there were no statistically significant differences between the pH value determined in the morning and afternoon hours on day 30 of lactation, while the pH value was significantly higher in the afternoon hours than in the morning hours on days 60 and 90 of lactation. There were no significant differences b, Cilj ovog istraživanja je bio da se ispita uticaj toplotnog stresa na vrednosti glikemije i pH krvi kod visokomlečnih krava u ranoj fazi laktacije, kao i da se utvrdi da li su promene ovih parametara u takvim uslovima međusobno zavisne. Ogled je izveden na visokomlečnim kravama tokom leta i proleća. Odabrano je četrdeset krava, po dvadeset za oba perioda ispitivanja. Tokom ogleda računati su satni toplotni indeksi (THI) za ceo period ispitivanja, a zatim i prosečan dnevni THI, noćnojutarnji THI (prosečna vrednost satnih THI izmerenih u periodu od 22h prethodnog dana do 10h ujutro tekućeg dana), kao i dnevnovečernji THI (prosečna vrednost satnih THI izmerenih u periodu od 10 h do 22 h tekućeg dana). U uzorcima krvi uzetim ujutru i posle podne 30, 60. i 90. dana laktacije tokom prolećnog i letnjeg perioda ispitivanja određivan je pH i koncentracija glukoze. Na osnovu rezultata za THI utvrđeno je da životinje u prolećnom periodu ispitivanja nisu bile izložene delovanju izrazitog toplotnog stresa, dok su tokom leta bile periodič no izložene umerenom, ali i izrazitom toplotnom stresu, posebno u poslepodnevnim satima. Iz dobijenih rezultata za pH krvi se može zaključiti da su krave tokom leta bile u respiratornoj alkalozi 30. dana u jutarnjim i popodnevnim, a 60. i 90. dana laktacije u popodnevnim satima, kao i 90. dana laktacije posle podne tokom prolećnog perioda ispitivanja. Tokom leta nije bilo statistički značajne razlike između pH vrednosti određene u jutarnjim i popodnevnim satima 30. dana laktacije, dok je 60. i 90. dana laktacije popodnevna vrednost za pH bila značajno veća u odnosu na jutarnju. Nije bilo značajnih razlika između prosečnih vrednosti glikemija tokom prolećnog perioda ispitivanja. Tokom leta prosečne popodnevne vrednosti glikemija 60. i 90. dana laktacije bile su značajno niže u odnosu na jutarnje. Glikemije izmerene 90. dana bile su statistički značajno niže od glikemija 30. i 60. dana laktacije, kako jutarnje tako i poslepodnevne. Glikemija je 90

The objective of this work was to examine the effect of heat stress on glucose and pH values in blood of high-yielding dairy cows in the early stage of lactation, as well as to determine whether the changes in these parameters are interdependent under such conditions. An experiment was performed on high-yielding dairy cows during the summer and the spring periods. Forty cows were selected, twenty each for the two periods under investigation. In the course of the experiment, the temperature humidity index (THI) was determined for the entire period of investigations, and then also the average daily THI, nightmorning THI (average value of hourly THI measured from 22h on the previous day until 10h of the current day), as well as the day-night THI (average value of hourly THI measured during the period from 10h to 22h of the current day). The pH and glucose concentration were determined in blood samples taken in the morning and afternoon of days 30, 60, and 90 of lactation during the spring and summer periods of the investigations. Based on the results for the THI, it was established that the animals were not exposed to the effect of extreme heat stress during the spring period of investigations, while they were periodically exposed to moderate but also extreme heat stress during the summer, in particular in the afternoon hours. It can be concluded from the results obtained for the blood pH that the cows were in respiratory alkalosis during the summer in the morning and afternoon hours on day 30, in the afternoon hours of days 60 and 90 of lactation, as well as in the afternoon on day 90 of lactation during the spring period of investigations. During the summer period, there were no statistically significant differences between the pH value determined in the morning and afternoon hours on day 30 of lactation, while the pH value was significantly higher in the afternoon hours than in the morning hours on days 60 and 90 of lactation. There were no significant differences b, Cilj ovog istraživanja je bio da se ispita uticaj toplotnog stresa na vrednosti glikemije i pH krvi kod visokomlečnih krava u ranoj fazi laktacije, kao i da se utvrdi da li su promene ovih parametara u takvim uslovima međusobno zavisne. Ogled je izveden na visokomlečnim kravama tokom leta i proleća. Odabrano je četrdeset krava, po dvadeset za oba perioda ispitivanja. Tokom ogleda računati su satni toplotni indeksi (THI) za ceo period ispitivanja, a zatim i prosečan dnevni THI, noćnojutarnji THI (prosečna vrednost satnih THI izmerenih u periodu od 22h prethodnog dana do 10h ujutro tekućeg dana), kao i dnevnovečernji THI (prosečna vrednost satnih THI izmerenih u periodu od 10 h do 22 h tekućeg dana). U uzorcima krvi uzetim ujutru i posle podne 30, 60. i 90. dana laktacije tokom prolećnog i letnjeg perioda ispitivanja određivan je pH i koncentracija glukoze. Na osnovu rezultata za THI utvrđeno je da životinje u prolećnom periodu ispitivanja nisu bile izložene delovanju izrazitog toplotnog stresa, dok su tokom leta bile periodič no izložene umerenom, ali i izrazitom toplotnom stresu, posebno u poslepodnevnim satima. Iz dobijenih rezultata za pH krvi se može zaključiti da su krave tokom leta bile u respiratornoj alkalozi 30. dana u jutarnjim i popodnevnim, a 60. i 90. dana laktacije u popodnevnim satima, kao i 90. dana laktacije posle podne tokom prolećnog perioda ispitivanja. Tokom leta nije bilo statistički značajne razlike između pH vrednosti određene u jutarnjim i popodnevnim satima 30. dana laktacije, dok je 60. i 90. dana laktacije popodnevna vrednost za pH bila značajno veća u odnosu na jutarnju. Nije bilo značajnih razlika između prosečnih vrednosti glikemija tokom prolećnog perioda ispitivanja. Tokom leta prosečne popodnevne vrednosti glikemija 60. i 90. dana laktacije bile su značajno niže u odnosu na jutarnje. Glikemije izmerene 90. dana bile su statistički značajno niže od glikemija 30. i 60. dana laktacije, kako jutarnje tako i poslepodnevne. Glikemija je 90

To the Editor: We thank Drs. Kemp et al. (3) for the opportunity to once again comment on the biochemistry of metabolic acidosis. However, we remain convinced that this continued interchange is not sufficiently based on science to contribute to an increased understanding of the biochemistry of metabolic acidosis. In addition, we are concerned that the letter by Kemp et al. (3) may further confuse the purpose and accomplishments of our original manuscript (5)...

The purpose of this study was to profile the effect of active versus passive recovery on acid-base kinetics during multiple bouts of intense exercise. Ten males completed two exercise trials. The trials consisted of three exercise bouts to exhaustion with either a 12 min active (20% workload max) or passive recovery between bouts. Blood pH was lower in the passive (p) recovery compared to active (a) throughout the second and third recovery periods [second recovery: 7.18 ± 0.08 to 7.24 < 0.05; third recovery: 7.17 ± 0.08 to 7.22 ± 0.09 (p), 7.23 ± 0.08 to 7.32 ± 0.08 (a), P < 0.05]. Exercise performance times did not differ between recovery conditions (P = 0.28). No difference was found between conditions for recovery kinetics (slope and half-time to recovery). Subsequent performance during multiple bouts of intense exercise to exhaustion may not be infl uenced by blood acidosis or mode of recovery.

The suprachiasmatic nuclei (SCN) of the hypothalamus are the site of the main circadian clock in mammals. Synchronization of the SCN to light is achieved by direct retinal inputs. The present study performed in rats transferred to constant darkness shows that blood glucose, pH and PCO2 display significant diurnal changes when measurements were made during the subjective day, the early subjective night or the late subjective night. The effects of a 30-min light exposure (100 lx) on these metabolic parameters at each of these circadian times were assessed. Regardless of the circadian time, light induced an increase in blood glucose, but did not affect plasma pH and PCO2. This study suggests that blood glucose, PCO2 and acid-base state are under circadian control, most likely mediated by the SCN, while the hyperglycemic response to light seems not to be gated by a circadian clock and may thus involve retinal inputs to non-SCN retino-recipient areas., Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S., SCOPUS: ar.j, info:eu-repo/semantics/published

The aims of this thesis were to: 1) develop a new method for the determination of interstitial pH at rest and during exercise in vivo, 2) systematically explore the effects of different ingestion regimes of 300 mg.kg-1 sodium citrate on blood and urine pH at rest, and 3) to combine the new interstitial pH technique with the findings of the second investigation in an attempt to provide a greater understanding of H+ movement between the extracellular compartments. The purpose of the first study was to develop a method for the continuous measurement of interstitial pH in vastus lateralis was successfully developed using microdialysis and 2,7-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF). To avoid the presence of an artificial alkalosis during exercise, it was necessary to add 25 mM HCO3- to the perfusate. The outlet of the probe was cut less than 10 mm from the skin and connected to a stainless steel tube completing the circuit to a microflow-through cuvette (8 fÝl) within a fluorescence spectrophotometer. This prevented the loss of carbon dioxide from the dialysate and any subsequent pH artefact. Interstitial pH was collected from six subjects before, during and after five minutes of knee-extensor exercise at three intensities 30, 50, and 70 W. Mean,,bSEM interstitial pH at rest was 7.38,,b0.02. Exercise reduced interstitial pH in an almost linear fashion. The nadir value for interstitial pH at 30, 50 and 70 W exercise was 7.27, 7.16 and 7.04, respectively. The lowest pH was obtained 1 min after exercise, irrespective of workload, after which the interstitial pH recovered in a nearly exponential manner. The mean half time of interstitial recovery was 5.2 min. The changes in interstitial pH exceeded the changes in venous blood pH. This study demonstrated that interstitial pH can be measured using microdialysis and that it is continuously decreased during muscle activity. The purpose of the second study was to establish an optimal ingestion regime for the in

[No abstract available]

There is evidence that differences in either maternal blood pH or dietary mineral content can result in alterations in secondary sex ratio in mammals. Altering the proportions of certain dietary minerals is known to influence blood pH, offering a possible explanation for this effect of diet on secondary sex ratio. The present study was performed to investigate whether altering blood pH by manipulating the dietary cation–anion difference (DCAD) would alter secondary sex ratio. The DCAD is calculated (in mEq per 100 g dry matter) as the difference between metabolically strong cations (Na+K) and metabolically strong anions (Cl+S) in the diet. Three hundred female mice were randomly allocated to either a low or high DCAD ration for 3 weeks before coitus. Urine pH was monitored before beginning the experiment, as well as before and after the breeding period, as a proxy for blood pH. Mice on the low DCAD diet had a lower urine pH (mean (±s.d.) 6.0±0.1) than mice on the high DCAD diet (8.2±0.6), but DCAD did not affect the percentage of mice that became pregnant, the number of offspring per pregnant mouse or the sex ratio of the neonate group. These results suggest that blood pH alone does not alter sex ratio and that an altered systemic pH is not the reason for reported mineral-related variations in sex ratio.