Rumen pH and fermentation characteristics in dairy cows supplemented with Megasphaera elsdenii NCIMB 41125 in early lactation.

This study investigated the effect of using the lactate-utilizing bacterium Megasphaera elsdenii NCIMB 41125 as a probiotic supplement on rumen fermentation and pH in dairy cows in the immediate postcalving period. Fourteen multiparous rumen-fistulated Holstein cows, blocked according to 305-d milk yield in the previous lactation, were used in a randomized complete block design. From d 1 to 28 postcalving, cows were fed ad libitum a total mixed ration with a forage to concentrate ratio of 392:608 and a starch concentration of 299g/kg of dry matter. Treatments consisting of a minimum of 10(10) cfu of Megasphaera elsdenii NCIMB 41125 or autoclaved M. elsdenii (placebo) were administered via the rumen cannula on d 3 and 12 of lactation (n=7 per treatment). Mid-rumen pH was measured every 15min, and eating and ruminating behaviors were recorded for 24h on d 2, 4, 6, 8, 11, 13, 15, 17, 22, and 28. Rumen fluid for volatile fatty acid and lactic acid analysis was collected at 11 time points on each of d 2, 4, 6, 13, and 15. Yields of milk and milk protein and lactose were similar, but milk fat concentration tended to be higher in cows that received the placebo. Time spent eating and ruminating and dry matter intake were similar across treatments. Ruminal lactic acid concentrations were highly variable between animals, and no cases of clinical acidosis were observed. Both treatment groups had rumen pH <5.6 for more than 3h/d (a commonly used threshold to define subacute ruminal acidosis), but the length of time with rumen pH <5.6 was markedly reduced in the days immediately after dosing and fluctuated much less from day to day in cows that received M. elsdenii compared with those that received the placebo. Ruminal total volatile fatty acid concentrations were similar across treatments, but the acetate:propionate ratio tended to be smaller in cows that received M. elsdenii. Despite the lack of a measurable treatment effect on ruminal lactic acid concentration, supplementation of early lactation dairy cows with lactate-utilizing M. elsdenii altered the rumen fermentation patterns in favor of propionate, with potential benefits for energy balance and animal productivity.

Effect of synchronization of energy and nitrogen supply on ruminal characteristics and microbial growth.

The effect of energy and N synchronization in the rumen on microbial growth was investigated. The same daily amount of readily available energy and N sources (19 g of ruminally degradable N/kg of fermentable OM) was supplied intraruminally to sheep, according to different patterns, namely both energy and N as 12-hourly pulse-doses (fast synchronized supply), energy as 12-hourly pulse-doses and N as a continuous infusion (unsynchronized supply), energy as a continuous infusion and N as 12-hourly pulse doses (unsynchronized supply), and both energy and N as continuous infusions (slow synchronized supply). The study was done near maintenance (Exp. 1) and at a higher level of nutrition (Exp. 2). The degree of energy and N synchronization affected neither microbial flow nor efficiency of growth (P > .2 for energy x N interaction). Continuous infusion of energy resulted in a 17% (P < .05) and 14% (P = .18) higher efficiency of microbial growth than did pulse dosing in Exp. 1 and 2, respectively. This coincided with lower (P < .01) ruminal pH and higher (P < .05) ruminal lactic acid concentration for energy pulse-dose treatments. The results suggest that merely improving the degree of synchronization between energy and N release rates in the rumen does not increase microbial yield. Dietary manipulation, rather, should be aimed at first obtaining the most even ruminal energy supply pattern, and then at providing the appropriate amount of ruminally available N. Thereafter some further advantage may be gained in also ensuring a more even N supply pattern, particularly avoiding too rapid a ruminal N release.

Urinary tract infection.

Between three per cent and five per cent of all girls and one per cent to two per cent of all boys will experience a urinary tract infection (UTI) before reaching puberty. While most of these children do not suffer permanent renal damage, a systematic approach to the management of UTI allows the detection of the minority who are at risk.

Obligation of clinicians to treat unwilling children and young people: an ethical discussion.

The refusal of a child or young person to comply with a clinician's recommendations for treatment creates a challenging ethical problem. We describe an approach that seeks to balance the clinician's duty of care to their patient with the need to respect and indeed foster the developing sense of autonomy in young people. Central to this approach is a theory in which the standard of competence required of a patient is flexible and commensurate with the level of medical risk inherent in the decision. High-risk situations require an exacting standard for the determination of competence whereas a lower standard may be accepted where risk is relatively minor. The argument also allows that levels of competence may fluctuate as a result of illness itself and be influenced by social and cultural factors to which a child is perhaps particularly prone. The obligations of treating clinicians in these circumstances are complex but we believe that a moral framework can be offered that clinicians will find useful in the treatment of unwilling children.

Continuous veno-venous hemodiafiltration using bicarbonate dialysate.

We report our experience with 11 children treated by continuous veno-venous hemodiafiltration. The median age was 5.0 years (range 3 days to 14 years). Access was via dual-lumen subclavian or femoral vein catheters. Hemofilters were chosen on the basis of patient size and dialysis requirements. Bicarbonate-buffered dialysis solution was prepared shortly before use by supplementation of a specially prepared base solution with commercially available electrolyte solutions. The mean ultrafiltration rate was 37.4 +/- 27 ml/kg body weight per hour. Urea and creatinine clearances were 15.1 +/- 6.4 ml/kg body weight per min and 16.4 +/- 8.4 ml/kg body weight per min, respectively. Metabolic acidosis was readily controlled in all patients. Of the 11 patients, 7 ultimately recovered normal renal function.

Increased incidence of renal transplant arterial stenosis in children.

We have found an increase from 10% to 16.4% in the incidence of clinically significant transplant arterial stenosis since the introduction of cyclosporin immunosuppression. During the same period there has been a coincidental increase in the use of donor kidneys harvested from children less than 6 years of age. In patients treated with cyclosporin these stenoses of the donor artery are not related to the surgical anastomosis, and have only rarely been associated with clinical or histological evidence of rejection, whereas those patients who have developed transplant arterial stenosis whilst receiving azathioprine have had a higher incidence of rejection. Regardless of immunosuppressive regimes, the use of small donor kidneys appears to be the most significant association with transplant arterial stenosis in our experience, and this finding has major implications for cadaveric renal transplantation in children.

Haemolytic-uraemic syndrome outbreak caused by Escherichia coli O111:H-: clinical outcomes.

In South Australia in 1995, we treated 20 children with haemolytic-uraemic syndrome associated with Escherichia coli O111:H-. The source of the outbreak was contaminated locally produced semi-dry fermented sausage (mettwurst). One child died of multiple haemorrhagic cerebral infarcts. Eighteen children required renal dialysis (for a median of 14 days); 12 months after discharge five still had significant impairment of renal function. Other major complications included colonic necrosis (3), cerebral haemorrhage/infarction (3), convulsions (4), and glucose intolerance (2). Although E. coli O111:H- has been associated with sporadic cases of haemolytic-uraemic syndrome, this was the first large outbreak reported in Australia.

Renal tract abnormalities detected in Australian preschool children.

OBJECTIVE: To quantify the incidence of abnormalities in urinalysis and blood pressure from preschool children and their predictive value in detecting renal disease within an Australian community. METHODOLOGY: Urine samples, blood pressure and height measurements and parental reports of significant medical problems were collected from a total of 9355 South Australian preschool children. Seven hundred and forty-three children with abnormal results were investigated in a nephrology outpatient clinic. A control group of 357 children with no detectable abnormality were also recalled, examined and, where appropriate, investigated. RESULTS: Nine thousand, three hundred and fifty-five children were tested. Of these, 0.81% were shown to have a clinically significant renal tract abnormality. The findings included children with urinary tract infections, vesico-ureteric reflux, glomerular disease, renal calculi, essential hypertension and a renal neoplasm. While dipstick-based methods were the most specific indicators of renal tract abnormalities, measurement of blood pressure and urinary beta2-microglobulin were also important in detecting abnormalities. Screening for glycosuria did not result in the detection of significant undiagnosed abnormalities. In the control group with no abnormality detected at testing, there was one case each of aortic coarctation, polycystic kidney disease and vesico-ureteric reflux diagnosed. CONCLUSION: Undiagnosed renal tract abnormalities are present in many Australian preschool children. Most are detectable by a thorough history, examination and urinalysis.

Surgical complications of the haemolytic uraemic syndrome.

During the first outbreak of haemolytic uraemic syndrome (HUS) to be reported in Australia, 22 children were admitted to the Women's and Children's Hospital, Adelaide. The outbreak was caused by an entero-haemorrhagic Escherichia coli strain (EHEC) of serotype 011:H-, a strain rarely implicated as a cause for HUS. In all 22 patients, the onset of HUS was preceded by a gastrointestinal (GI) prodrome. All patients had diarrhoea. In 17 (73%), the diarrhoea became bloody; in 20 (86%) there was vomiting; in 15 (65%) there was abdominal pain; and in 12 (50%) all three symptoms were present. Abdominal symptoms continued to complicate the course of 4 patients. Two of these underwent exploratory laparotomy, both had gangrenous colon excised, and both survived. The 2 remaining patients were successfully treated non-operatively. One further patient underwent appendicectomy before the diagnosis of HUS was made. There was 1 death during this epidemic. In patients with HUS and GI involvement, optimal surgical management requires careful consideration of the indications for, and the timing of, surgical intervention.

Evaluation of long-term aggressive dietary management of chronic renal failure in children.

Ten children with chronic renal failure (CRF) were managed for 3 years using a strict low-protein and low-phosphorus diet supplemented by a mixture of the keto and amino forms of the essential amino acids and histidine (phase II). All of these children were previously managed for at least 2 years with a less rigorous diet of limited protein intake with no specific reduction of phosphorus (phase I). Energy, vitamin D, bicarbonate, phosphate binders and vitamin and mineral mixtures were added as required during both dietary phases. Data on dietary intake showed a significant fall in protein and phosphorus intake and a rise in calcium intake during phase II compared with phase I. Plasma calcium increased and phosphate fell, with an associated fall in intact parathyroid hormone levels. There was a marked improvement in urea creatinine ratios, which suggested an improved anabolic state. Cholesterol and triglyceride levels were improved. Height and weight velocity were increased, becoming significant after 3 years of phase II. Renal function deteriorated at a slower rate than predicted. The diet was well tolerated by the children, with fitness and school performance showing improvement. We conclude that long-term strict dietary management of children with CRF is feasible. Our data suggest an overall improvement in general health and an apparent reduction in the rate of deterioration of renal function.

Accelerated growth in short children with chronic renal failure treated with both strict dietary therapy and recombinant growth hormone.

In a 12-month study, nine boys, aged 4.8-15.6 years, with bone ages 4.6-13 years, with moderate to severe chronic renal failure and resultant growth failure were treated with daily recombinant human growth hormone (rhGH), in conjunction with a strict low-protein/low-phosphate diet supplemented with keto and amino forms of the essential amino acids, histidine and additional energy. Improved growth had previously been observed with this dietary management over that obtained with conventional treatment for chronic renal failure. Each child had been on this diet for at least 2 years before rhGH was commenced. Mean height velocity increased from 4.6 +/- 1.3 to 9.0 +/- 1.3 cm/year (P < 0.001) in the pre-pubertal group, and in the pubertal group from 5.4 +/- 1.4 to 10.4 +/- 1.8 cm/year (P < 0.01). The mean height velocity standard deviation scores (SDSs) increased from -1.2 +/- 0.6 to +2.3 +/- 0.9 (P < 0.001) in the pre-pubertal group and from -0.4 +/- 0.6 to +1.9 +/- 1.1 (P < 0.01) in the pubertal group. Mean height SDS for chronological age increased from -2.2 +/- 0.7 to -1.5 +/- 0.5 (P < 0.01) in the pre-pubertal group and from -1.9 +/- 0.7 to -1.3 +/- 0.9 in the pubertal group (P < 0.02). There was no significant deterioration in renal function or renal bone disease, and bone age did not advance more than chronological age over the 12-month period.

Plasminogen activator inhibitor type-1 and interleukin-6 in haemolytic uraemic syndrome.

OBJECTIVE: Because haemolytic uraemic syndrome (HUS) is an important cause of renal dysfunction in children, the availability of prognostic markers of disease severity could assist in identifying those at risk of developing long-term sequelae. The aim of this study was to test the hypothesis that plasma levels of plasminogen activator inhibitor type-1 (PAI-1) and interleukin-6 (IL-6) in children at the time of diagnosis of HUS would predict renal function outcome in terms of glomerular filtration rate (GFR). METHODOLOGY: Fourteen children suffering from diarrhoeal HUS were studied. Plasma samples were assayed for PAI-1 and IL-6, and GFR was measured at intervals after discharge from hospital. Twelve months following their recovery from HUS, the children were allocated to one of two outcome groups depending on whether GFR was above (Good Outcome, n = 9), or below (Poor Outcome, n = 5) 80 mL/min per 1.73 m2. RESULTS: Elevated concentrations of PAI-1 were found in 4 of 5 Poor Outcome and 4 of 9 Good Outcome children. At the same time, increased concentrations of IL-6 were observed in 3 of 5 Poor Outcome and 3 of 9 Good Outcome children. Renal function continued to be compromised in four Poor Outcome children 36 months after diagnosis. CONCLUSIONS: Our data show that PAI-1 and IL-6 are elevated in the plasma of some children at the time of diagnosis of HUS, but that neither is a definitive prognostic marker of poor outcome 3 years later.