Nocturnal polyuria is the excretion at night of an excessive volume of urine. A major problem following renal transplantation is an abnormal diurnal rhythmicity in urine output. The purpose of this study was to elucidate the prevalence of nocturnal polyuria among renal transplant recipients in the early period after transplantation as well as at least 1 year after transplantation. We aimed to explore possible pathophysiological mechanisms behind nocturnal polyuria in this group of patients, focusing on the impact of blood pressure and medication.
Seventeen recently transplanted patients 17 late transplant recipients, and 17 healthy controls were included in the study. Voiding habits were assessed by completion of a frequency-volume chart recording all fluid intakes and voiding. A concomitant 24-hour blood pressure profile was obtained in all.
Renal transplant recipients had a high prevalence of nocturnal polyuria (74%) and a disturbed blood pressure profile with a lack of appropriate nocturnal dipping (P
Susceptibility to experimental autoimmune myasthenia gravis (EAMG) was found to decrease with aging in both Lewis and Brown Norway (BN) rats. In this study, the difference in susceptibility between young and aged Lewis and BN rats was used to analyze factors determining the clinical severity of EAMG. The incidence and severity of muscular weakness did not correlate with acetylcholine receptor (AChR) loss nor with the ability of antibodies to interfere with AChR function. Aged rats showed significantly lower anti-rat AChR antibody titers than young rats and developed less severe or no clinical signs of disease. In individual young or aged rats, however, no significant correlation was found between the clinical signs of disease and anti-rat AChR titer. Neuromuscular transmission was found to change with aging as measured by single-fiber electromyography (SFEMG). In aged BN rats, increased jitter and blockings were found even before EAMG induction. Despite this disturbed neuromuscular transmission, these aged BN rats were clinically resistant against induction of EAMG. The results of this study indicate that the age-related susceptibility to EAMG is influenced by factors determined by the immune attack as well as mechanisms at the level of the neuromuscular junction.
The influence of two food types, Boreogadus saida (Bs) and crustaceans (Cr), on the osmolality, ion concentrations, antifreeze activity and antifreeze glycoprotein (AFGP) distribution in the gastrointestinal fluids of the Arctic gadoid Arctogadus glacialis was determined. The gastrointestinal fluids were hyperosmotic to serum but no significant differences in osmolality were found between the two food types. The food type significantly affected the antifreeze activity of the mid-gut fluids. The hysteresis freezing points, -3.27+/-0.30 degrees C and -2.44+/-0.11 degrees C for B. saida and crustaceans, respectively, were significantly lower than that of serum (-1.99+/-0.07 degrees C). Furthermore, an exceptionally large thermal hysteresis ranging from 1.47+/-0.19 degrees C to 2.04+/-0.30 degrees C was observed in the intestinal fluids of fish feeding on B. saida. Native gel electrophoresis revealed that the gastrointestinal fluids contained AFGPs in all the different size groups. However, differences in band intensities for the two food types suggest that the ingested food has an influence on the concentration of the different AFGP-sizes in these fluids. A decrease in band intensities combined with a drop in thermal hysteresis from mid-gut to hind-gut fluid suggests that absorption of AFGP or possibly degradation occur during digestion.
IGF-I has an almost 50% amino acid sequence homology with insulin and elicits nearly the same hypoglycemic response. Studies showed that low and high IGF-I levels are related to impaired glucose tolerance and to a higher risk of type 2 diabetes. The aim of the current study was to evaluate the association between IGF-I level and insulin resistance in a Danish general population.
Included were 3,354 adults, aged 19-72 years, from the cross-sectional Health2006 study. The homeostasis model assessment of insulin resistance (HOMA-IR) was used as the index to estimate insulin resistance. Serum IGF-I levels were determined by an immunoassay and grouped into quintiles (Q1-Q5). Linear or multinomial logistic regression analyses were performed.
In the study population, 520 subjects (15.5%) had increased HOMA-IR values above 2.5. After adjustment for age, sex, physical activity, and waist-to-height ratio, a U-shaped association between IGF-I and HOMA-IR was found. Low IGF-I (Q1: odds ratio [OR] 1.65 [95% CI 1.16-2.34], P
ATP receptor mediated Ca2+ signaling was recorded from Bergmann glial cells in cerebellar slices obtained from mice of different ages (postnatal days 6 to 45). To measure the cytoplasmic concentration of Ca2+ ([Ca2+]in), either individual cells were loaded with the Ca(2+)-sensitive probes using the whole cell patch clamp technique or slices were incubated with the dye and the microfluorimetric system was focused on individual cells. Signals were recorded either with single-detector microfluorimetry of the dye fura-2 or by confocal laser scanning microfluorimetry (fluo-3-based recordings). Extracellular application of 100 microns ATP caused a transient elevation of [Ca2+]in, which amplitude was significantly higher in Bergmann glial cell processes as compared with their soma. The rank order of potency for the purinoreceptor agonists was: ADP > or = ATP > UTP >> AMP = adenosine = alpha, beta-methylene-ATP. ATP-triggered Ca2+ transients were reversibly inhibited by the P2 purinoreceptor agonist suramin (100 microM). The involvement of P2 metabotropic receptors is inferred by the observation that ATP mediated cytoplasmic Ca2+ transients were not associated with a measurable change in membrane conductance. The [Ca2+]in increase was due to release from inositol-1,4,5-trisphosphate (InsP3)-sensitive intracellular stores since responses were still observed in Ca(2+)-free extracellular solutions and were irreversibly blocked by the inhibitor of the sarco(endo)plasmic reticulum Ca2+ ATPase, thapsigargin, and by the competitive inhibitor of the InsP3-gated intracellular Ca2+ channels heparin. Intracellular dialysis altered the refilling process of the InsP3-sensitive stores, suggesting that cytoplasmic factors control ATP mediated Ca2+ signalling.
Apparent quantum yields of carbon monoxide (CO) photoproduction (AQY(CO)) for permafrost-derived soil dissolved organic matter (SDOM) from the Yukon River Basin and Alaska coast were determined to examine the dependences of AQY(CO) on temperature, ionic strength, pH, and SDOM concentration. SDOM from different locations and soil depths all exhibited similar AQY(CO) spectra irrespective of soil age. AQY(CO) increased by 68% for a 20 °C warming, decreased by 25% from ionic strength 0 to 0.7 mol L(-1), and dropped by 25-38% from pH 4 to 8. These effects combined together could reduce AQY(CO) by up to 72% when SDOM transits from terrestrial environemnts to open-ocean conditions during summer in the Arctic. A Michaelis-Menten kinetics characterized the influence of SDOM dilution on AQY(CO) with a very low substrate half-saturation concentration. Generalized global-scale relationships between AQY(CO) and salinity and absorbance demostrate that the CO-based photoreactivity of ancient permaforst SDOM is comparable to that of modern riverine DOM and that the effects of the physicochemical variables revealed here alone could account for the seaward decline of AQY(CO) observed in diverse estuarine and coastal water bodies.
The aim of this study was to monitor the metabolism and blood flow in the interstitium of the skeletal muscle during cardiac surgery with cardiopulmonary bypass (CPB) and in the early postoperative period by means of microdialysis and to compare metabolic changes during CPB at normothermia (NT) and hypothermia (HT). Surgical revascularization using CPB was performed in 50 patients, 25 patients (group HT) were operated using hypothermic CPB, 25 (group NT) using normothermic CPB. Interstitial microdialysis was performed by two CMA 60 probes (CMA Microdialysis AB, Solna, Sweden) inserted into the patient's deltoid muscle. Constituents analysed in the obtained dialysates, collected at intervals, were glucose, urea, glycerol and lactate. Tissue blood flow was monitored by dynamic microdialysis with gentamicin as a marker. In both groups, NT versus HT, similar dynamics of concentrations were found. Low initial concentrations were followed by gradual increases during CPB and in the following phase of the operation. Concentrations were higher in the NT group. Immediately after the operation, the decrease in values continued, with a gradual increase in the succeeding postoperative period in both groups. Similar dynamic changes in the lactate concentration were found in both groups. The gentamicin concentrations were lower in the NT group (versus the HT group). The results showed dynamic changes in the interstitial concentrations of glucose, urea, glycerol and lactate, which depend on the phase of the surgery in the CPB and early postoperative phase in the both groups of patients. Higher tissue perfusion of the skeletal muscle was noted in those patients operated on in normothermia. The dynamics of the concentration changes of these substances in the interstitium of the skeletal muscle has been proven to be caused by both the metabolic activity of the tissue and by the blood flow through the interstitium of the muscle.
Plasma concentrations of cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo) B, and lipoprotein(a) (Lp[a]) in 46 persons heterozygous for the apo B-3500 mutation causing familial defective apo B-100 (FDB) were compared with those in 57 non-FDB relatives. FDB patients had 50% to 70% higher mean concentrations of cholesterol, LDL cholesterol, and apo B than non-FDB relatives (P 50 years old had atherosclerotic disease. In contrast, all 18 non-FDB relatives > 50 years old were apparently healthy. A total of 8 FDB patients with atherosclerotic disease had 36% higher cholesterol concentrations, 28% higher apo B concentrations, 50% higher triglyceride concentrations, and 120% higher Lp(a) concentrations than FDB patients without clinical atherosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)
In this study, ageotropum pea mutant was used to determine the threshold time for perception of an osmotic stimulation in the root cap and the time requirement for transduction and transmission of the hydrotropic signal from the root cap to the elongation region. The threshold time for the perception of an osmotic stimulation was compared to current estimates of threshold times for graviperception in roots. The time required for transduction and transmission in the hydrotropic response of ageotropum was compared to the time requirement in the gravity response of Alaska pea roots. We determined that threshold time for perception of an osmotic stimulation in the root cap is very rapid, occurring in less than 2 min following the application of sorbitol to the root cap. Furthermore, a single 5 min exposure of sorbitol to the root cap fully induced a hydrotropic response. We also found that transduction and transmission of an osmotic stimulus requires 90-120 min for movement from the root cap to more basal tissues involved in differential growth leading to root curvature. The very rapid threshold time for perception of root hydrotropism is similar to those times reported for root gravitropism. However, the time required for the transduction and transmission of an osmotic stimulation from the root cap is significantly longer than the time required in gravitropism. These results suggest that there must exist some differences between root hydrotropism and gravitropism in either the rate or mechanisms of transduction and transmission of the tropistic signal from the root cap.
Iopentol is a new nonionic, water-soluble ratio 3.0 roentgen contrast medium (CM) for vascular use. The aim is to present the vascular clinical trial program for iopentol and to report the findings from the clinical phases I and II. The clinical program started with an intravenous (IV) safety and pharmacokinetic phase I trial (24 volunteers) and continued with six open, noncomparative phase II trials (61 patients) for studying cardiovascular and arterial tolerance (two trials in cardioangiography), venous tolerance (two trials in IV computed tomography [CT] enhancement), and cerebral and arterial tolerance (2 trials in cerebral arteriography). One volunteer in the phase I trial was excluded because of a vasovagal reaction following saline injection, and four patients were protocol deviators in cardioangiography. Mainly renal glomerular filtration of unmetabolized iopentol, close to 100% recovered after 24 hours in the urine, was found in the phase I study. No unexpected or severe contrast-induced reactions were encountered in phases I and II. Good diagnostic efficiency was obtained in phase II. As also expected, iopentol seemed to be well-tolerated. However, its relative efficiency and tolerance profile can only be documented from the ongoing comparative phase III trials.