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Galacto-oligosaccharides (GOS) are non-digestible oligosaccharides characterized by a mix of structures that vary in their degree of polymerization (DP) and glycosidic linkage between the galactose moieties or between galactose and glucose. They have enjoyed extensive scientific scrutiny, and their health-promoting effects are supported by a large number of scientific and clinical studies. A variety of GOS-associated health-promoting effects have been reported, such as growth promotion of beneficial bacteria, in particular bifidobacteria and lactobacilli, inhibition of pathogen adhesion and improvement of gut barrier function. GOS have attracted significant interest from food industries for their versatility as a bioactive ingredient and in particular as a functional component of infant formulations. These oligosaccharides are produced in a kinetically-controlled reaction involving lactose transgalactosylation, being catalyzed by particular β-galactosidases of bacterial or fungal origin. Despite the well-established technology applied for GOS production, this process may still meet with technological challenges when employed at an industrial scale. The current review will cover relevant scientific literature on the beneficial physiological properties of GOS as a prebiotic for the infant gut microbiota, details of GOS structures, the associated reaction mechanism of β-galactosidase, and its (large-scale) production.

Epidural anesthesia has been considered the gold standard for perioperative analgesia, but the implementation of enhanced recovery after surgery (ERAS) protocols and a shift from open to laparoscopic surgery have diminished the advantage of epidural anesthesia. The authors summarize data from two newer meta-analyses and discuss the consequences for the role of epidural anesthesia (EA) in the perioperative setting. These meta-analyses enabled to distinguish between pre- and post-ERAS outcomes. Endpoints related to open and laparoscopic abdominal surgery were retrieved. General data, also applicable on abdominal surgery, were included. Data on other types of surgery were ignored. Two meta-analyses met the subject and inclusion criteria of the search. They demonstrate no difference between epidural analgesia and the control for most investigated endpoints. Analgesia employing epidural techniques is often not clinically superior to its alternatives; is associated with a small but relevant number of serious complications; and has a relatively high failure rate. Data show that the distinction between pre-ERAS and ERAS is essential for understanding the role of EA in intestinal surgery. Since ERAS was introduced, the advantages of epidural anesthesia vanished while the incidence of serious neurological complications is higher than previously thought. The authors conclude that epidural anesthesia in abdominal surgery has become less preferred and is limited to patients and types of surgery known to be accompanied with difficult pain management. This requires the use of other methods for analgesia, such as intravenous ketamine, peripheral nerve blocks, continuous wound infiltration, intrathecal morphine, and intravenous, and non-invasive PCA.

A 35-year old dockworker sustained a pelvic injury when he was caught by a large loading clamshell grab. Primary survey revealed an open book pelvic fracture with soft tissue defects of the left thigh and groin. CT scanning of the thorax and abdomen did not reveal significant additional injuries. Partly due to patient’s haemodynamical instability, osteosynthesis of the pelvic fracture was performed immediately after resuscitation, whereby the severely contaminated wound of the thigh was debrided and irrigated. The following days, progressive facial subcutaneous emphysema developed, but patient remained clinically stable. Several specialists were consulted, but did not find a cause. At day 7, a second surgery was planned to treat a pelvic surgical wound infection. Unexpectedly, we found faecal contamination in the pelvic surgical wound. The consulted gastro/intestinal-surgeon performed a laparoscopic colostomy for a rectal laceration. Awareness for bowel injuries with open pelvic fracture should be high, also when subcutaneous emphysema is found remotely.

This systematic review summarizes the research of previous studies that used resistance training in the post-treatment phase of cancer patients with a focus on methodological quality, training methods and physical outcome measures. We found twenty-four studies (10 RCTs, 4 controlled clinical trials and 10 uncontrolled trials) that met all inclusion criteria. The studies were of moderate methodological quality. The majority of studies involved breast cancer patients (54%), followed by prostate cancer patients (13%). Most studies used a combination of resistance and aerobic training, which was mostly supervised. Resistance training involved large muscle groups, with 1-3 sets of 8-12 repetitions. The duration of the resistance training programs varied from 3-24 weeks, with a training frequency of 1-5 sessions per week. The training intensity ranged from 25% to 85% of the one-repetition maximum. Overall, positive training effects were observed for cardiopulmonary and muscle function, with significant increases in peak oxygen uptake (range: 6-39%), and in the one-repetition maximum (range: 11-110%). In general, there were no effects of training on body composition, endocrine and immune function, and haematological variables. No adverse effects of the resistance training were reported. Based upon these results, we recommend to incorporate resistance training in cancer rehabilitation programmes.

Upon hydrolysis with chymotrypsin, soy glycinin has a strong tendency to aggregate. The regions of glycinin from which the aggregating peptides originate were identified by accumulative-quantitative peptide mapping. To this end, the aggregating peptides were further hydrolyzed with trypsin to obtain peptides of which the sequence can be identified using RP-HPLC-MS/MS. This resulted in a hydrolysate in which 90% of the proteinaceous material was dissolved. The soluble fraction was analyzed using the method of accumulative-quantitative peptide mapping: fractionation using ion exchange chromatography, followed by identification of peptides by RP-HPLC-MS/MS, quantification based on the absorbance at 214 nm, and finally peptide mapping. For the peptide mapping the proportions in which each of the five glycinin subunits are present, as determined by Edman degradation, were taken into account. The results showed that mainly the basic polypeptide and a part of the acidic polypeptide, close to the location of the disulfide bridge between the basic and acidic polypeptides, are present in the aggregating peptide fraction. On the basis of the results obtained, an aggregation mechanism was proposed. The hydrophilic acidic polypeptides shield the hydrophobic basic polypeptides, and the former are preferentially degraded upon hydrolysis. This results in a net increase in hydrophobicity of the remaining material, which mainly consists of the basic polypeptide fragments. This increase in hydrophobicity is proposed to be the driving force in the aggregation of chymotrypsin-derived peptides of glycinin.

Cardiac remodelling is commonly defined as a physiological or pathological state that may occur after conditions such as myocardial infarction, pressure overload, idiopathic dilated cardiomyopathy or volume overload. When training excessively, the heart develops several myocardial adaptations causing a physiological state of cardiac remodelling. These morphological changes depend on the kind of training and are clinically characterised by modifications in cardiac size and shape due to increased load. Several studies have investigated morphological differences in the athlete's heart between athletes performing strength training and athletes performing endurance training. Endurance training is associated with an increased cardiac output and volume load on the left and right ventricles, causing the endurance-trained heart to generate a mild to moderate dilatation of the left ventricle combined with a mild to moderate increase in left ventricular wall thickness. Strength training is characterised by an elevation of both systolic and diastolic blood pressure. This pressure overload causes an increase in left ventricular wall thickness. This may or may not be accompanied by a slight raise in the left ventricular volume. However, the development of an endurancetrained heart and a strength-trained heart should not be considered an absolute concept. Both forms of training cause specific morphological changes in the heart, dependent on the type of sport. (Neth Heart J 2008;16:129-33.). AD - Department of Cardiology, Maastricht University Hospital, Maastricht, the Netherlands.

OBJECTIVE: To assess possible ergogenic properties of corticosteroid administration. DESIGN: A balanced, double blind, placebo-controlled design was used. PARTICIPANTS: Twenty-eight well-trained cyclists and rowers. INTERVENTION: Four weeks daily inhalation of 800 microg budesonide or placebo. Main outcome measurements: The subjects performed three incremental cycle ergometer tests until exhaustion, before and after two and four weeks of placebo or budesonide administration, to measure maximal power output (Wmax). Once a week they filled in a profile of mood state (POMS) questionnaire. RESULTS: There was no significant difference in Wmax between the placebo (376+/-25 watt) and the corticosteroid group (375+/-36 watt) during the pre-intervention test, and there were no significant changes in either group after two and four weeks of intervention. No effect of the intervention on mood state was found. CONCLUSION: Four weeks of corticosteroid or placebo inhalation in healthy, well-trained athletes did not affect maximal power output or mood state. Hence no ergogenic properties of four weeks corticosteroid administration could be demonstrated, which corroborates previous studies with short-term corticosteroid administration.

Soy-derived proteins (soy protein isolate, glycinin, and ß-conglycinin) and bovine whey-derived proteins (whey protein isolate, ¿-lactalbumin, ß-lactoglobulin) were hydrolyzed using subtilisin Carlsberg, chymotrypsin, trypsin, bromelain, and papain. The (in)solubility of the hydrolysates obtained was studied as a function of pH. At neutral pH, all soy-derived protein hydrolysates, particularly those from glycinin, obtained by hydrolysis with subtilisin Carlsberg, chymotrypsin, bromelain, and papain showed a stronger aggregation compared to the non-hydrolyzed ones. This increase in aggregation was not observed upon hydrolysis by trypsin. None of the whey-derived protein hydrolysates exhibited an increase in aggregation at neutral pH. The high abundance of theoretical cleavage sites in the hydrophobic regions of glycinin probably explains the stronger exposure of hydrophobic groups than for the other proteins, which is suggested to be the driving force in the aggregate formation. Keywords: Aggregation; Peptides; Soy protein; Whey protein

Background: Creatine supplementation is popular among tennis players but it is not clear whether it actually enhances tennis performance. Objectives: To examine the effects of creatine supplementation on tennis specific performance indices. Methods: In a randomised, double blind design, 36 competitive male tennis players (24 creatine, mean (SD) age, 22.5 (4.9) years; 12 placebo, 22.8 (4.8) years) were tested at baseline, after six days of creatine loading, and after a maintenance phase of four weeks (14 creatine, 10 placebo). Serving velocity (10 serves), forehand and backhand velocity (three series of 5×8 strokes), arm and leg strength (bench press and leg press), and intermittent running speed (three series of five 20 metre sprints) were measured. Results: Compared with placebo, neither six days nor five weeks of creatine supplementation had a significant effect on serving velocity (creatine: +2 km/h; placebo: +2 km/h, p = 0.90); forehand velocity (creatine: +4 km/h; placebo: +4 km/h, p = 0.80), or backhand velocity (creatine: +3 km/h; placebo: +1 km/h, p = 0.38). There was also no significant effect of creatine supplementation on repetitive sprint power after 5, 10, and 20 metres, (creatine 20 m: −0.03 m/s; placebo 20 m: +0.01 m/s, p = 0.18), or in the strength of the upper and lower extremities. Conclusions: Creatine supplementation is not effective in improving selected factors of tennis specific performance and should not be recommended to tennis players.

Effect of testosterone and endurance training on glycogen metabolism in skeletal muscle of chronic hyperglycaemic female rats.van Breda E, Keizer H, Kuipers H, Kranenburg G.Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, Maastricht, The Netherlands. vanbreda@bw.unimaas.nlOBJECTIVES: To investigate in glycolytic and oxidative muscles of trained (nine weeks) and untrained hyperglycaemic female rats the effect of hyperandrogenicity and/or endurance training on energy metabolic properties. METHODS: Glycogen content and activity of muscle enzymes with regulatory functions in glycogen synthesis were examined. RESULTS: Testosterone treatment increased glycogen content of extensor digitorum longus (EDL) and soleus muscles of hyperglycaemic sedentary (18% and 84% respectively) and hyperglycaemic trained (7% and 16% respectively) rats. In both types of muscle of the hyperglycaemic testosterone treated exercised subgroup, less depletion of glycogen was found than in the untreated group (38% and 87% for EDL and soleus respectively). CONCLUSIONS: The mechanisms by which training and/or hyperandrogenism alone or in combination elicits their specific effects are complex. Differences in sex, surgery, levels of hormones administered, and exercise model used may be the main reasons for the observed discrepancies. Conclusions from the results: (a) hyperandrogenism is not a primary cause of the development of insulin resistance; (b) glycogen content of slow and fast twitch muscle is increased by training through increased glycogen synthase activity. The most plausible explanation for differences between different muscle fibre types is the different levels of expression of androgen receptors in these fibres. Hyperandrogenicity therefore acts on energy metabolic variables of hyperglycaemic animals by different mechanisms in glycolytic and oxidative muscle fibres

Department of Psychiatry and Neuropsychology and Academic Anxiety Center, Maastricht University, Maastricht, The Netherlands. OBJECTIVE: To test the possible antipanic effects of acute exercise in healthy volunteers exposed to an inhalation of 35% CO2 challenge. METHOD: Twenty healthy subjects in a randomized separate group design, performed exercise in a bicycle ergometer reaching >6 mm of blood lactate and a control condition of minimal activity in the same fashion with no lactate elevation. Immediately afterwards an inhalation of a vital capacity using a mixture of 35% CO2/65% O2 through a mask was given on both conditions. RESULTS: Subjects under the exercise condition reported less panic symptoms than controls after a CO2 challenge on the diagnostic statistical manual-IV (DSM-IV) Panic Symptom List but no difference on the Visual Analogue Anxiety Scale. CONCLUSION: Subjects under the exertion condition had lactate levels comparable with those of lactate infusions but an inhibitory rather than accumulative effect was seen when combined with a CO2 challenge.

Objectives—(a) To investigate the effects of reduced training on physical condition and performance in well trained cyclists; (b) to study whether an intermittent exercise programme would maintain physiological training adaptations more effectively than a continuous exercise programme during a period of reduced training.Methods—Twelve male cyclists participated in a 21 day training programme and were divided into two training groups. One group (age 25.3 (7) years; weight 73.3 (5.7) kg; Vo2max58.6 (4.5) ml/kg/min; means (SD)) underwent a continuous endurance exercise training programme (CT) whereas the second group (age 22.8 (3.5) years; weight 74.1 (7.0) kg; Vo2max59.7 (6.7) ml/kg/min) followed an intermittent endurance exercise training programme (IT). During this reduced training period, both groups trained for two hours a day, three days a week.Results—Neither group showed changes in maximal workload (Wmax) (4.6 (0.5)v4.8 (0.5) W/kg and 4.6 (0.5)v4.7 (0.6) W/kg for the CT and IT group respectively) and Vo2max(58.6 (4.5)v60.1 (5.8) ml/kg/min and 59.7 (6.7)v58.8 (7.5) ml/kg/min for the CT and IT group respectively). During the submaximal steady state exercise test, substrate use and heart rate remained unchanged after reduced training.Conclusions—These results indicate that well trained cyclists who reduce training intensity and volume for 21 days can maintain physiological adaptations, as measured during submaximal and maximal exercise. An intermittent training regimen has no advantage over a continuous training regimen during a detraining period.

A new method was developed to identify regions in proteins from which peptides are derived with specific functional properties. This method is applicable for systems in which peptides of a hydrolyzed protein possess specific functional properties, but are too large to be sequenced directly and/or the peptide mixture is too complex to purify and characterize each peptide individually. In the present work, aggregating peptides obtained by proteolytic hydrolysis of soy glycinin were used as a case study. The aggregating peptides are isolated and subsequently further degraded with trypsin to result in peptides with a mass

The aggregation behavior as a function of pH was studied for hydrolysates obtained by hydrolysis of soy protein isolate (SPI) and glycinin- and ß-conglycinin-rich protein fractions with subtilisin Carlsberg. The substrates were hydrolyzed up to degrees of hydrolysis (DH) of 2.2% and 6.5%. Compared with nonhydrolyzed SPI, a decrease in solubility was observed for the hydrolysates of SPI [0.8% (w/v) protein, I¿=¿0.03 M] around neutral pH. At pH 8.0, glycinin hydrolysates had a much lower solubility (~43% and 60%, respectively, for DH 2.2% and 6.5%) than SPI and ß-conglycinin-derived hydrolysates, which were almost completely soluble. Peptides that aggregated were all larger than 5 kDa, and as estimated by size-exclusion chromatography their composition was almost independent of the aggregation pH. The solubility of hydrolysates of SPIs with a varying glycinin and ß-conglycinin composition showed that glycinin-derived peptides are the driving force for the lower solubility of SPI hydrolysates. The solubility of SPI hydrolysates at pH 8.0 was shown not to be the sum of that of glycinin and ß-conglycinin hydrolysates. Assuming that the separate hydrolysis of glycinin and ß-conglycinin did not differ from that in the mixture (SPI), this indicates that ß-conglycinin-derived peptides have the ability to inhibit glycinin-derived peptide aggregation.

OBJECTIVES: To identify educational needs of elite sportspeople with respect to the doping laws. METHODS: A questionnaire survey of 196 Olympic level sportspeople from the fields of athletics, cycling, rowing, and sailing. The questionnaire addressed the date and source of the last doping educational update, the usefulness of current resources, sources of help, and possible ways of improving the system. The questionnaire also sought to estimate the use of nutritional supplements in these sports. RESULTS: Seventy four (38%) athletes responded to the questionnaire. Over 90% of responders had received a doping educational update in the last six months, and most agreed with the statement "I have received the information I need to avoid getting into trouble with the doping laws". Despite this, more than half of responders agreed with the statements "I should receive reminders more often" and "The authorities should do more to educate sportspeople". In addition, there were four people who admitted taking a banned substance by accident. Forty one (55%) reported taking supplements. The team doctor was the most popular source if information on a substance or product was required, with 62% and 66% of subjects stating that they would contact their team doctor when based in the United Kingdom and abroad respectively. The UK Sports website was often suggested in relation to ways of improving knowledge. CONCLUSIONS: There is a need to alter the educational process, particularly with respect to contingency planning for minor illness. The use of internet based resources for up to date information about banned substances needs to be promoted, and access to the internet improved. The educational needs of team doctors with respect to the doping laws need to be assessed.

Objectives:To investigate the effects of two different regimens of androgenic-anabolic steroid (AAS) administration on serum lipid and lipoproteins, and recovery of these variables after drug cessation, as indicators of the risk for cardiovascular disease in healthy male strength athletes.Methods:In a non-blinded study (study 1) serum lipoproteins and lipids were assessed in 19 subjects who self administered AASs for eight or 14 weeks, and in 16 non-using volunteers. In a randomised double blind, placebo controlled design, the effects of intramuscular administration of nandrolone decanoate (200 mg/week) for eight weeks on the same variables in 16 bodybuilders were studied (study 2). Fasting serum concentrations of total cholesterol, triglycerides, HDL-cholesterol (HDL-C), HDL2-cholesterol (HDL2-C), HDL3-cholesterol (HDL3-C), apolipoprotein A1 (Apo-A1), apolipoprotein B (Apo-B), and lipoprotein (a) (Lp(a)) were determined.Results:In study 1 AAS administration led to decreases in serum concentrations of HDL-C (from 1.08 (0.30) to 0.43 (0.22) mmol/l), HDL2-C (from 0.21 (0.18) to 0.05 (0.03) mmol/l), HDL3-C (from 0.87 (0.24) to 0.40 (0.20) mmol/l, and Apo-A1 (from 1.41 (0.27) to 0.71 (0.34) g/l), whereas Apo-B increased from 0.96 (0.13) to 1.32 (0.28) g/l. Serum Lp(a) declined from 189 (315) to 32 (63) U/l. Total cholesterol and triglycerides did not change significantly. Alterations after eight and 14 weeks of AAS administration were comparable. No changes occurred in the controls. Six weeks after AAS cessation, serum HDL-C, HDL2-C, Apo-A1, Apo-B, and Lp(a) had still not returned to baseline concentrations. Administration of AAS for 14 weeks was associated with slower recovery to pretreatment concentrations than administration for eight weeks. In study 2, nandrolone decanoate did not influence serum triglycerides, total cholesterol, HDL-C, HDL2-C, HDL3-C, Apo-A1, and Apo-B concentrations after four and eight weeks of intervention, nor six weeks after withdrawal. However, Lp(a) concentrations decreased significantly from 103 (68) to 65 (44) U/l in the nandrolone decanoate group, and in the placebo group a smaller reduction from 245 (245) to 201 (194) U/l was observed. Six weeks after the intervention period, Lp(a) concentrations had returned to baseline values in both groups.Conclusions:Self administration of several AASs simultaneously for eight or 14 weeks produces comparable profound unfavourable effects on lipids and lipoproteins, leading to an increased atherogenic lipid profile, despite a beneficial effect on Lp(a) concentration. The changes persist after AAS withdrawal, and normalisation depends on the duration of the drug abuse. Eight weeks of administration of nandrolone decanoate does not affect lipid and lipoprotein concentrations, although it may selectively reduce Lp(a) concentrations. The effect of this on atherogenesis remains to be established.

BACKGROUND: Studies relating certain chemokine and chemokine receptor gene alleles with the outcome of HIV-1 infection have yielded inconsistent results. OBJECTIVE: To examine postulated associations of genetic alleles with HIV-1 disease progression. DESIGN: Meta-analysis of individual-patient data. SETTING: 19 prospective cohort studies and case-control studies from the United States, Europe, and Australia. PATIENTS: Patients with HIV-1 infection who were of European or African descent. MEASUREMENTS: Time to AIDS, death, and death after AIDS and HIV-1 RNA level at study entry or soon after seroconversion. Data were combined with fixed-effects and random-effects models. RESULTS: Both the CCR5-Delta32 and CCR2-64I alleles were associated with a decreased risk for progression to AIDS (relative hazard among seroconverters, 0.74 and 0.76, respectively; P = 0.01 for both), a decreased risk for death (relative hazard among seroconverters, 0.64 and 0.74; P < 0.05 for both), and lower HIV-1 RNA levels after seroconversion (difference, -0.18 log(10) copies/mL and -0.14 log(10) copies/mL; P < 0.05 for both). Having the CCR5-Delta32 or CCR2-64I allele had no clear protective effect on the risk for death after development of AIDS. The results were consistent between seroconverters and seroprevalent patients. In contrast, SDF-1 3'A homozygotes showed no decreased risk for AIDS (relative hazard for seroconverters and seroprevalent patients, 0.99 and 1.03, respectively), death (relative hazard, 0.97 and 1.00), or death after development of AIDS (relative hazard, 0.81 and 0.97; P > 0.5 for all). CONCLUSIONS: The CCR5-Delta32 and CCR2-64I alleles had a strong protective effect on progression of HIV-1 infection, but SDF-1 3'A homozygosity carried no such protection. Ann Intern Med

As the exercise intensity is often expressed as percentage of either maximal workload (%Wmax), percentage of maximal heart rate (%HRmax), or as percentage of maximal oxygen uptake, the relationship between %Wmax, %VO2max, and %HRmax was determined in 53 male cyclists. All subjects performed an incremental maximal cycle ergometer test. In all athletes examined, a linear relation between power output, oxygen uptake and heart rate was observed. The relationships between %Wmax and %VO2max as well as between %Wmax and %HRmax were linear (r = 0.98 and r = 0.97; p < 0.001). It is concluded that studies which are different in expression of exercise intensity (%Wmax or %VO2max) can be compared and that the relation between %Wmax and %HRmax needs to be determined individually when an appropriate individualized training intensity based on heart rate is required.

Bei 16 Patienten betrug die im Bioassay gemessene Imipenemkonzentration im organischen Knochen 45 Minuten nach einer 15minutigen Kurzinfusion von 1 g Imipenem/Cilastation (geometrischer Mittelwert ± Standardabweichung aus n=13) 4,3 ± 2,06 mg/kg und nach 88 Minuten 2,8 ± 1,86 mg/kg (n=26). Imipenem last sich in den anorganischen Hydroxylapatit imbutieren, verliert jedoch dabei seine antibakterielle Aktivitat. Im Serum betrug die mittlere Spitzenkonzentration bei 12 Paienten (mittleres Alter 77 Jahre) mit normaler Nieren- und Leberfunktion 15 Minuten nach Infusionsbeginn 93,1 mg/l Imipenem. Die Serumhalbwertszeit t (1/2beta) lag im Schnitt bei 1,32 Stunden, die totale Clearance betrug 108,6 l/Std. und das Verteilungsvolumen in der Beta-Phase V (beta) 12,4 l.

The prevalence and incidence of cytomegalovirus (CMV) infections were studied in a group of homosexual men. Of the 710 participants, 501 (70.6%) had complement fixing antibodies to CMV on entry to the study. During the follow up (maximum 23 months) 69 CMV infections were found: 50 primary infections among the 209 seronegative men (attack rate 27.3%), and 19 recurrent infections among the 501 seropositive men (attack rate 6.2%). The prevalence of antibody to CMV was correlated with four characteristics of the participants' lifestyles: duration of homosexual activity, number of different sexual partners, history of syphilis, and anal sexual contact. Among the seronegative men, the incidence of primary infection with CMV correlated with a history of syphilis and anal sexual contact. We conclude that infections with CMV are highly prevalent among homosexual men, and that anal sexual contact plays an important part in the transmission of this virus.

In pycnometer determinations of the pore volume of 2-5-mm air-dry aggregates from various soils of 1.5-2.5 and 2.6-3.5% organic-matter levels and various clay contents, the use of kerosene (S. & F. XVII [1897]) gave as good values as, and was more convenient than, the use of sand or mercury (the latter giving low porosities). The pore-space percentage of aggregates could be calculated from the water content at pF 2, when no air voids in the small aggregates are likely to occur and water between the aggregates is of no importance. Dry aggregates were only slightly denser in cores of light soils than under field conditions, and swelling was small; dry aggregates were very dense in heavy soils in which moisture content and density of aggregates appeared so closely related that it was difficult to distinguish between the effect of either on the strength of aggregates. Swelling properties and aggregate size are likely to be important factors in the structure of heavy soils. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Highlights • Active site characteristics of the β-galactosidase enzyme of Bacillus circulans ATCC 31382. • Residues essential for catalysis were identified by structure-based alignments. • Mutational analysis identified two catalytic glutamate amino acid residues., The Bacillus circulans ATCC 31382 β-galactosidase (BgaD) is a retaining-type glycosidase of glycoside hydrolase family 2 (GH2). Its commercial enzyme preparation, Biolacta N5, is used for commercial-scale production of galacto-oligosaccharides (GOS). The BgaD active site and catalytic amino acid residues have not been studied. Using bioinformatic routines we identified two putative catalytic glutamates and two highly conserved active site histidines. The site-directed mutants E447N, E532Q, and H345F, H379F had lost (almost) all catalytic activity. This confirmed their essential role in catalysis, as general acid/base catalyst (E447) and nucleophile (E532), and as transition state stabilizers (H345, H379), respectively.

In a study of 689 male homosexuals 290 (42%) were found to have antibodies to hepatitis A virus. The 399 men who did not have antibodies were followed up for up to 690 days, and 35 cases of hepatitis A were detected. The attack rate at the end of the study was 14%. The incidence climbed steadily, indicating that the cases of hepatitis A did not occur in clusters. Statistical analysis showed that the prevalence of antibodies to hepatitis A virus was significantly correlated with the duration of homosexual activity (p less than 0.006), and this was independent of age. The incidence of hepatitis A was found to be correlated with the number of different sexual partners in the preceding six months. It is concluded that hepatitis A is a sexually transmitted disease among homosexual men in countries with a low rate of exposure to hepatitis A during childhood.

The mechanical properties of remoulded samples of eight soils from the IJsselmeer polders were investigated. The Atterberg (Plastic and Liquid) Limits were positively correlated with the soil clay content, but were not significantly correlated with the organic matter content. Artificial aggregates of the remoulded soil age-hardened when moist. The tensile strength of artificial aggregates was positively correlated with the soil clay content and negatively correlated with the porosity. Friability of the dried, remoulded soil was much lower than that of natural, undisturbed soil. Factors affecting the rates of wetting and drying of aggregates in the laboratory were examined in detail. Wetting resulted in mellowing (or softening) of artificial aggregates. Mellowing was investigated as a function of the potential of the source of water causing the wetting. Multiple wetting and drying cycles may result in increased mellowing or in no mellowing depending on the water potential. New terminology is introduced to facilitate discussion of these phenomena. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Strenuous exercise activates the hypothalamic-pituitary-adrenal (HPA) axis. Several reports showed that physical training is associated with a decreased efficiency of the feedback control of HPA axis. The aims of the present study were: 1) to evaluate the differences in the mechanical, hormonal, and lactate responses to a high-intensity isokinetic exercise among different groups of competitive athletes (CA, no.=20) of power and endurance disciplines and sedentary controls (SED, no.=10); 2) to determine the effects of the training status on the HPA axis responsiveness following exercise, as indirectly evaluated by the rates of ACTH, cortisol, and DHEA recovery after exercise. CA and SED fulfilled eight sets of twenty concentric contractions of the knee extensors at 180 degrees/sec angular velocity throughout a constant range of motion (100 degrees). There was a rest period of 30 sec between each set and a 3-min rest period between the two legs. Before, immediately after the isokinetic exercise and at different times in the subsequent 120 min of recovery, blood and saliva were sampled to determine plasma ACTH, salivary cortisol, serum DHEA, and serum lactate concentrations. CA showed a higher cortisol response to exercise than SED, whereas no differences were found in the responses of ACTH, DHEA and lactate. In the athlete group the exercise-induced increases of ACTH, cortisol, and lactate were higher in power athletes with respect to endurance athletes. No differences were observed between athletes and SED in the rates of hormonal recovery after exercise: this finding does not support the concept that a reduced feedback control of HPA axis can represent a feature of trained individuals.