High-intensity interval training improves insulin sensitivity in older individuals.

AIM: Metabolic health may deteriorate with age as a result of altered body composition and decreased physical activity. Endurance exercise is known to counter these changes delaying or even preventing onset of metabolic diseases. High-intensity interval training (HIIT) is a time efficient alternative to regular endurance exercise, and the aim of this study was to investigate the metabolic benefit of HIIT in older subjects. METHODS: Twenty-two sedentary male (n = 11) and female (n = 11) subjects aged 63 ± 1 years performed HIIT training three times/week for 6 weeks on a bicycle ergometer. Each HIIT session consisted of five 1-minute intervals interspersed with 1½-minute rest. Prior to the first and after the last HIIT session whole-body insulin sensitivity, measured by a hyperinsulinaemic-euglycaemic clamp, plasma lipid levels, HbA1c, glycaemic parameters, body composition and maximal oxygen uptake were assessed. Muscle biopsies were obtained wherefrom content of glycogen and proteins involved in muscle glucose handling were determined. RESULTS: Insulin sensitivity (P = .011) and maximal oxygen uptake increased (P < .05) in both genders, while plasma cholesterol (P < .05), low-density lipoprotein (P < .05), visceral fat mass (P < .05) and per cent body fat (P < .05) decreased after 6 weeks of HIIT. HbA1c decreased only in males (P = .001). Muscle glycogen content increased in both genders (P = .001) and in line GLUT4 (P < .05), glycogen synthase (P = .001) and hexokinase II (P < .05) content all increased. CONCLUSION: Six weeks of HIIT significantly improves metabolic health in older males and females by reducing age-related risk factors for cardiometabolic disease.

Strategies for evaluating the sanitary quality of composting.

AIMS: To evaluate different strategies for description of the sanitary quality of industrial-scale composting. METHODS AND RESULTS: The investigation included microbiological analyses of waste at different stages during the process (spot test analysis), as well as physical and chemical parameters. The elimination of indicator organisms was also investigated by means of direct process evaluation, based on inoculation of the waste. At the four investigated facilities, the sanitary process was very efficient when evaluated by the direct process evaluation, indicated by an efficient elimination of Escherichia coli and Enterococcus faecalis inoculated into the waste. The sanitization was poor when evaluated by spot test analysis at the two windrow facilities, while good agreement was found at the two in-vessel facilities. CONCLUSIONS: The direct process evaluation is a valuable tool for identifying parameters for process optimization in different zones and for measuring elimination patterns of pathogens not normally present in the waste, but it is unreliable for evaluating the overall sanitary process. SIGNIFICANCE AND IMPACT OF THE STUDY: The spot test analysis is an accurate method for the analysis of the sanitary process. In addition, it is simple and inexpensive to perform, which makes it very cost-effective for supervision of the sanitary quality of industrial-scale composting.

Effects of diabetes on calcium uptake by rat brush border membrane vesicles.

1. We investigated the mechanism of decreased transmucosal calcium transport in the gut of the diabetic rat by comparing calcium uptake by brush border membrane vesicles from control and streptozotocin diabetic rats at 5 days. Brush border calcium uptake consists of saturable and non-saturable components. Saturable uptake is mediated by a specific mobile carrier mechanism and is defined by Vmax (saturable uptake of calcium at infinite medium calcium concentration) and KT (calcium concentration at Vmax/2). Non-saturable uptake is defined by kD (rate constant for non-saturable uptake per unit calcium concentration), and comprises both diffusive and surface binding components of calcium uptake. 2. We found both saturable and non-saturable calcium uptake to be decreased (P < 0.05) in diabetes. Comparing control and diabetic, Vmax was 247 compared to 152 (data are pmol/mg protein per 3 s); kD was 285 compared to 172 (data are pmol/mg protein per 3 s at 1 mmol/L calcium); and KT (mmol/L) did not differ between groups, 0.070 compared to 0.057. 3. The decreased Vmax in the setting of unchanged KT in vesicles from diabetics is consistent with decreased calcium transporter specific activity, rather than with altered transporter function. 4. Since (i) Vmax is decreased by vitamin D deficiency in the normal rat, and (ii) circulating 1 alpha, 25-dihydroxycholecalciferol is decreased in the diabetic rat, decreased Vmax in the diabetic may be related to the low 1 alpha,25-dihydroxycholecalciferol.(ABSTRACT TRUNCATED AT 250 WORDS)

Surface charge, fluidity, and calcium uptake by rat intestinal brush-border vesicles.

Biological membrane outer surfaces are negatively charged and interact with positively charged calcium ion during calcium uptake. Positively charged polycations such as polyarginine bind to membranes with high affinity, displacing bound calcium from the membrane. We tested the effect of polyarginine on uptake of calcium by brush-border membrane vesicles and examined the responses in terms of membrane fluidity by electron paramagnetic resonance (EPR). Polyarginine inhibited the saturable component of calcium uptake by a mechanism combining inhibition characteristics of strontium (competitive) and magnesium (non-competitive). Unlike the inhibition of non-saturable calcium uptake by strontium and magnesium, polyarginine increased kD, the rate constant for non-saturable calcium uptake, by a concentration dependent mechanism. These effects of polyarginine on calcium uptake were associated with decreased membrane fluidity at the uptake temperature. These findings are consistent with a role for surface negative charge in determining both saturable and non-saturable calcium uptake. Increased membrane fluidity is associated with decreased saturable and increased non-saturable calcium uptake. Although increased fluidity might be involved in the increased kD for non-saturable uptake, the concentration-specific stimulating effect of polyarginine suggests a gating mechanism.

Vitamin D and enterocyte brush border membrane calcium transport and fluidity in the rat.

Prior studies of vitamin D repletion showed a threefold increase in the maximum rate (Vmax) for calcium uptake by brush border membrane vesicles, but did not differentiate saturable and nonsaturable uptake components. We studied the calcium uptake and fluidity response of intestinal brush border vesicles to vitamin D by treatment with 1 alpha,25-dihydroxy-24,24-difluorocholecalciferol (24,24-F-1,25-(OH)2D3). Treatment responses were measured by effects on (1) saturable and nonsaturable initial uptake rates of calcium by rat proximal small intestinal brush border membrane vesicles; (2) transmucosal calcium transport by everted duodenal sac; and (3) fluorescence anisotropy. Treatment of vitamin D-depleted weanlings increased the Vmax by 50% (P < .05) in vesicles from the proximal 12 cm of small intestine from rats injected with disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP), but there was no response in rats not injected with EHDP or in vesicles from the proximal 30 cm of small intestine. Vitamin D-depleted weanlings were D-deficient based on serum 25-hydroxycalciferol(25-OH-D) concentration, but to produce 1 alpha,25-dihydroxycalciferol [1,25-(OH)2D] depletion, EHDP injection was required. Treatment of vitamin D-replete adult rats caused a 20% (P < .05) increase in Vmax. Treatment did not affect the calcium concentration at half-Vmax (KT), the rate constant for nonsaturable uptake (KD), or vesicle fluidity measured as fluorescence anisotropy. Contrasting with these minimal effects of treatment on brush border Vmax, treatment increased transmucosal calcium transport by everted duodenal sac almost threefold in vitamin D-depleted weanlings administered EHDP. Thus, vitamin D actions on enterocyte calcium transport (1) at the brush border increase saturable but not nonsaturable uptake, and (2) produce the major transport response distal to the brush border. Despite previously described changes in membrane lipid, brush border fluidity is unaffected by vitamin D treatment.

Brush border calcium uptake in short-bowel syndrome in rats.

Resection of distal small intestine causes calcium malabsorption in humans and in a rat model of 50% distal resection. We tested the hypothesis that this calcium malabsorption is caused in the rat model by a brush border defect. We compared brush border membrane vesicles from the proximal small intestine of control (transection and anastomosis at mid-small intestine) with distally resected rats. Mucosal protein was 25% greater in the resected group and the vesicles were enriched 37-fold in sucrase activity when compared with homogenate. Kinetic constants Vmax (maximal initial rate of saturable calcium uptake at infinite concentration), kT (calcium concentration for saturable calcium uptake rate at half Vmax), and KD (rate constant for nonsaturable calcium uptake per unit concentration) were slightly but not significantly greater in the resected as compared with the transected group, ruling out the brush border as the cause for decreased transmucosal calcium transport.

Chlorhexidine for prevention of neonatal colonization with group B streptococci. V. Chlorhexidine concentrations in blood following vaginal washing during delivery.

Chlorhexidine 2 g/l was applied to the vagina of 96 women during delivery, whereas 28 served as controls. Both groups were given a shower using a chlorhexidine soap, and outer washing of the outer anogenital tract was also performed in all patients using chlorhexidine 2 g/l. Using a gas chromatographic method with a detection limit of 10 ng chlorhexidine per ml blood, 10-83 ng/ml was demonstrated in 34 (35%) of the study group patients, whereas the remaining study group patients and controls showed no detectable chlorhexidine. Performing the washing a second time after 6 hours in 14 patients and a third time in 3 patients after a further 6 hours did not result in increased serum levels. It was concluded that small amounts of chlorhexidine are absorbed through the vaginal mucosa and that chlorhexidine is not accumulated in the blood on repeated usage with 6 hour intervals during delivery.

Reduced rate of postoperative infections in emergency cesarean section after two doses of cefuroxim perioperatively. A placebo-controlled study.

The rate of postoperative infections after cesarean section was studied in a prospective double-blind randomized study to compare cefuroxim with a placebo. Intravenous bolus injections were given at the beginning of, and 12h after the operation. Eighty patients received cefuroxim and 80 received placebo. Endometritis or wound infection, or both, was diagnosed in 2/80 (2.5%) patients receiving cefuroxim and in 23/80 (29%) patients receiving placebo. No side effects were demonstrated or reported by the patients. Thus, two bolus injections of 1.5 g of cefuroxim given perioperatively significantly reduced postoperative infectious morbidity after emergency cesarean section.

Early-onset neonatal group B streptococcal septicaemia in siblings.

At each of two consecutive deliveries, a woman gave birth to a baby that developed early-onset group B streptococcal (GBS) septicaemia. A low titre of serum antibodies to the type of the infecting GBS and persistence of the organism in the mother were demonstrated. This case confirms that mothers of GBS infected infants are at high risk of their future babies being similarly infected.

Evaluation of a new commercial kit (UROBACT) for detection of bacteriuria.

A new commercially available method (UROBACT, AB Dermaci, Sweden) for detection of bacteriuria was compared to a conventional semiquantitative bacteriological method. The kit consisted of two tubes, which were inoculated with urine in two different dilutions. Positive tests were recorded as a colour change from red to yellow in both tubes, and the test was considered negative if one or both tubes remained red. When studying 556 urine samples, the test detected 153 of 163 samples with greater than or equal to 10(5) colony forming units (CFU) of bacteria per ml, i.e. the sensitivity was 93.9%. Among the samples containing less than 10(5) CFU/ml, 347 of 357 were recorded as negative, giving a specificity of 97.2%. Although relatively few urine samples containing Staphylococcus saprophyticus and Pseudomonas pyoceanea were tested the results indicated that the method was less reliable for these species. However, compared to dip-slides, which also give poor results with S. saprophyticus, the new test has several advantages, including a more simple interpretation, i.e. a distinct colour change.

Chlorhexidine for prevention of neonatal colonization with group B streptococci. IV. Depressed puerperal carriage following vaginal washing with chlorhexidine during labour.

The effect of vaginal washing with chlorhexidine acetate, 2 g/l at delivery, on the colonization of the urogenital tract with group B streptococci (GBS) 4 days later was investigated. Patients who were culture-positive for GBS in urethra and/or cervix in pregnancy weeks 32 and 36 as well as at delivery were included in a prospective study. The washing procedure was performed in 31 parturients, and 10 (32%) were culture-negative at day 4 after delivery. In contrast, only 7/47 (15%) non-washed controls were negative at day 4 (p = 0.044). The results demonstrate a prolonged suppressive effect of vaginal washing with chlorhexidine on the recovery of GBS from the urogenital tract in this highly selected patient group.

Effect of a strict preoperative hygienic routine on the rate of infections following cesarean section.

The frequency of postoperative infections after cesarean section was studied during two periods. In the first period no strict preoperative hygienic routines were applied; 321 patients were delivered by cesarean section during this period. In the next period strict hygienic routines were introduced; this period included 337 patients. The infection rate was significantly reduced during the second period from 20% to 16%. This reduction was found among the elective operations, and among parturients who had been treated in the hospital for more than 24 h prior to delivery. The frequency of endometritis decreased significantly from the first to the second period, whereas no difference was found concerning wound infections. Significantly fewer patients contracted septicemia during the second period. Since all septicemia cases occurred in endometritis patients the results might indicate that not only the number of patients contracting infection but also the severity of the infections was reduced. No reduction of infections was found after emergency operations. Antibiotic prophylaxis might therefore be of value in this group of patients.

IgG subclasses and antibodies to group B streptococci, pneumococci, and tetanus toxoid in preterm neonates after intravenous infusion of immunoglobulin to the mothers.

High doses of intravenous immunoglobulin were given to seven pregnant women between the 27th and 36th wk of gestation who were at risk for preterm delivery. Determinations of IgG subclasses and of antibodies against group B streptococcal serotypes, pneumococcal polysaccharides, and tetanus toxoid were done in maternal serum before and after intravenous IgG infusion and after delivery in cord serum. Substantial transplacental passage of the infused material could be observed in five cases where delivery occurred at the 34th wk or later. After the 36th wk of gestation, IgG subclass and antibody concentrations in cord serum were increased up to the levels in the maternal serum.

Blocking of antibody complement-dependent effector functions by streptococcal IgG Fc-receptor and staphylococcal protein A.

Using haemolysis in gel, two bacterial IgG-binding substances, an Fc-receptor isolated from group A streptococci type M15, and protein A from Staphylococcus aureus, were shown to inhibit complement-mediated lysis of sheep erythrocytes sensitized with rabbit IgG. When the crude alkaline extracts of ten types of group A streptococci were tested to see whether streptococcal components other than Fc-binding material might affect lysis, the degree of inhibition was found to be correlated with Fc-binding activity. In no case was the lysis of IgM-coated cells inhibited. Opsonophagocytosis experiments showed that both purified streptococcal Fc-receptor and protein A impaired antibody complement-dependent killing by human polymorphonuclear leukocytes of each of two strains of group B streptococci (lacking IgG Fc-receptors). Furthermore, the impairment was ascribable to interference with the fixation of complement to the antibodies, as demonstrated in pre-opsonization experiments with one of the strains. Our results suggest that blocking of the binding of complement to IgG is an important virulence mechanism in Fc-receptor-bearing streptococci and staphylococci.

Opsonization of group B streptococci in properdin deficient serum.

Phagocytic killing of group B streptococci serotypes Ia, Ib, IIR- (R protein negative), IIR+ (R protein positive), IIIR- and IIIR+ by human granulocytes was studied after opsonization in properdin deficient serum, pooled normal human serum and in selected sera with high or low concentrations of antibody to group B streptococci. All serotypes were killed by granulocytes after opsonization in normal serum, but serotype IIIR- was comparatively resistant. Properdin deficient serum showed no opsonic activity for type IIIR-. A reduced opsonic capacity of properdin deficient serum for serotypes Ib and IIR+ was demonstrated, whereas the other serotypes were efficiently opsonized. The reduced or absent opsonic activity of properdin deficient serum could be restored by addition of purified properdin. Antibody levels did not appear to be limiting in the assay system. Blocking of C1 activation with MgEGTA in normal serum delayed, but did not abolish opsonization of the various group B streptococcal serotypes, while the opsonic activity in chelated properdin deficient serum was markedly reduced. Taken together, the findings suggest that an intact classical pathway is crucial in group B streptococcal opsonization. However, efficient opsonization of some strains apparently requires that C3 activation on the bacterial surface is amplified through recruitment of the alternative pathway.