A Toll-like receptor-1 variant and its characteristic cellular phenotype is associated with severe malaria in Papua New Guinean children.

Genetic factors are likely to contribute to low severe malaria case fatality rates in Melanesian populations, but association studies can be underpowered and may not provide plausible mechanistic explanations if significant associations are detected. In preparation for a genome-wide association study, 29 candidate single-nucleotide polymorphisms (SNPs) with minor allele frequencies >5% were examined in a case-control study of 504 Papua New Guinean children with severe malaria. In parallel, an immunological substudy was performed on convalescent peripheral blood mononuclear cells (PBMCs) from cases and controls. Following stimulation with a Toll-like receptor (TLR) 1/2 agonist, effector cytokines and chemokines were assayed. The only significant genetic association observed involved a nonsynonymous SNP (TLR1rs4833095) in the TLR1 gene. A recessive (TT) genotype was associated with reduced odds of severe malaria of 0.52 (95% confidence interval (0.29-0.90), P=0.006). Concentrations of pro-inflammatory cytokines interleukin-1ß and tumour necrosis factor α were significantly higher in severe malaria cases compared with healthy controls, but lower in children with the protective recessive (TT) genotype. A genetic variant in TLR1 may contribute to the low severe malaria case fatality rates in this region through a reduced pro-inflammatory cellular phenotype.

CORB is the best pneumonia severity score for elderly hospitalised patients with suspected pneumonia.

Pneumonia severity scoring systems have been developed to identify patients at highest mortality risk, and are used in guidelines to limit use of broad-spectrum antibiotics to patients with severe community-acquired pneumonia. A retrospective audit of hospitalised general internal medicine patients with pneumonia was performed to assess the diagnostic performance of various pneumonia severity scores in an elderly general internal medicine population.

Diagnosis of tuberculous lymphadenitis using fine needle aspiration biopsy.

BACKGROUND: Tuberculous lymphadenitis is the commonest form of extrapulmonary tuberculosis. However, the optimal approach to diagnosis, employing biopsy by either fine needle aspiration (FNA) or surgical excision, remains uncertain. AIMS: To evaluate the diagnostic value of biopsy using each of the component diagnostic modalities of FNA (microscopy, cytology and culture), and compare these with excision biopsy in the diagnosis of tuberculous lymphadenitis in a predominantly migrant population in Melbourne. METHODS: A retrospective examination of tuberculous lymphadenitis cases presenting to Western Health over 12 years was conducted. Using a reference method of positive culture of Mycobacterium tuberculosis, the diagnostic sensitivities of each modality employed in FNA were determined. RESULTS: Forty-two subjects having FNA and 30 having excision biopsy as the initial investigation were compared. Among specimens obtained by FNA, sensitivity of microscopy was 18% (95% confidence interval (CI): 5­40%) and sensitivity of cytology was 38% (95% CI: 20­59%). For specimens obtained by excision biopsies, sensitivities for microscopy and histology were 17% (95% CI: 2­32%) and 96% (95% CI: 88­100%) respectively. Sensitivity of culture performed on FNA specimens was 86% (95% CI: 65­97%). CONCLUSIONS: Given the relatively high sensitivity of mycobacterial cultures from FNA, this study supports its routine use as the initial investigation in most patients with suspected tuberculous lymphadenitis. Microscopy and cytology add relatively little to the clinical utility of FNA

Asymptomatic bacteriuria as a predictor of subsequent hospitalisation with urinary tract infection in diabetic adults: The Fremantle Diabetes Study.

AIMS/HYPOTHESIS: We examined the prognosis of well-characterised community-based diabetic patients with asymptomatic bacteriuria (ASB). METHODS: We studied 496 adults with type 1 or 2 diabetes participating in a prospective observational study. In addition to detailed clinical and laboratory data, a single mid-stream urine sample was taken for aerobic culture and antibiotic-sensitivity testing. ASB was defined as >/=10(5) colony-forming units/ml of one or two organisms without symptoms of urinary infection. Patients were followed for 2.9+/-0.6 years for hospital admission for/with urosepsis or death. RESULTS: Thirty-six patients (7.3%) had ASB, comprising 33 females (14.4% of all females) and three males (1.1% of all males). Only female sex predicted ASB amongst a range of variables including indices of metabolic control. Twenty-nine patients (5.8%) were subsequently hospitalised with urosepsis. Of these, urosepsis was the principal diagnosis in 12 (41%). In a Cox proportional hazards model, ASB was associated with an increased risk of hospitalisation for urosepsis as principal diagnosis (hazard ratio [95% CI] 4.4 [1.2-16.5]; p=0.004). ASB did not predict the combined endpoint of hospitalisation with urosepsis as principal or secondary diagnosis (2.3 [0.8-6.7]; p=0.12), or of non-urinary sepsis as principal (n=12) or principal/secondary (n=28) diagnosis (p>0.3). CONCLUSIONS/INTERPRETATION: ASB identifies diabetic patients who are at significantly increased risk of subsequent urosepsis requiring hospitalisation. Further large-scale studies are needed to establish the cost-effectiveness of screening for, and pre-emptive treatment of ASB, especially in females.

Seroprevalence of varicella zoster virus, parvovirus B19 and Toxoplasma gondii in a Melbourne obstetric population: implications for management.

At an antenatal clinic at a Melbourne obstetric hospital, 308 women were questioned about a known past history of infection with varicella zoster virus (VZV), human parvovirus B19 and Toxoplasma gondii. Immunoglobulin G (IgG) concentrations were determined for the 3 infectious agents and a recalled history of infection was compared with the presence of specific antibody. Exactly 66% of women recalled being infected with chickenpox (VZV) and 94% showed serological evidence of past exposure. Although 64% of women had parvovirus specific IgG, only one gave a definite history of past parvovirus infection. None of the 23% of women with evidence of previous exposure to Toxoplasma gondii recalled a past infection. The proportion of antenatal women at risk in this study was used to estimate the potential burden of disease from congenital infections in Australia and to examine implications for management of pregnancies complicated by these 3 infections.

Influence of dietary electrolyte balance, source of added potassium and anticoccidial agents on the performance of male broilers.

1. The performance of 1680 male broiler chickens was measured from one to 42 d of age. They were given diets with three (125, 165 and 205 mEq/kg) electrolyte balances (sodium + potassium - chloride), two sources of added potassium (carbonate or sulphate) and two anticoccidial agents (90 mg/kg of either monensin or lasalocid). 2. The dietary treatments had no significant effects on the growth performance of broiler chickens in the starter phase. 3. In the finisher phase, the chickens given the diets containing lasalocid utilised food less efficiently that those given the diets containing monensin. 4. There were significant interactions between dietary electrolyte balance and source of added potassium on body weight gains and food:gain ratios in the finisher phase. In diets with an electrolyte balance of 205 mEq/kg, the inclusion of potassium sulphate instead of potassium carbonate increased body weight gains by 3.4% and reduced food:gain ratios by 4.6%. 5. The body weight gains of chickens given the finisher diets containing lasalocid and added potassium carbonate were reduced by 2.6% compared to those of chickens given the diets containing monensin or added potassium sulphate. 6. The litter moisture content was higher in pens with chickens on the diets with an electrolyte balance of 205 mEq/kg than on the diets with either 125 or 165 mEq/kg. Both lasalocid and potassium sulphate tended to increase the litter moisture content. 7. It may be concluded that the inclusion of 90 mg/kg of either monensin or lasalocid in broiler diets does not alter the balance of electrolytes required for optimum growth performance of broiler chickens.

Effect of dietary phosphorus concentration and electrolyte balance on the growth performance of broiler chickens.

The performance of 1680 male and female broiler chickens given diets with either a low (4.7-4.3 g/kg) or high (8.9-8.2 g/kg) content of inorganic phosphorus and four (150, 200, 250 and 300 mEq/kg) electrolyte balances (Na+K-Cl) was measured from 1-d-old to 49 d of age. Diets with the higher concentration of inorganic phosphorus reduced body weight gains in the starter (P less than 0.01) and finisher (P less than 0.05) phases but the efficiency of food utilisation was reduced only in the starter phase (P less than 0.05). The reduction in body weight gain was greater in males than in females. The growth depression caused by the higher concentration of inorganic phosphorus in the finisher diets was partially alleviated by increasing the electrolyte balance to either 250 or 300 mEq/kg diet. The higher concentration of inorganic phosphorus significantly reduced the dressing percentage and increased the abdominal fat pad weight and litter moisture content. Electrolyte balance had no significant effects on efficiency of food utilisation, abdominal fat pad weights or litter moisture content. Neither the dietary concentration of phosphorus nor the electrolyte balance had a significant effect on mortality or ash content of the tibia.

The effects of dietary minerals and electrolytes on the growth and physiology of the young chick.

The effects of the mineral elements, calcium and available phosphorus (aP), and the electrolytes, sodium, potassium and chloride in the diet on the growth and physiology of male broiler-type chickens were investigated. The concepts of total dietary cation-anion and electrolyte (Na + K - Cl, meq/kg) balance were compared for their ability to describe observed growth and various parameters to 42 d of age. There were 12 dietary treatments; each was given to four replicates of 32 birds housed in a deep-litter, environmentally controlled shed. Diets were nutritionally adequate and were based on practical ingredients. Total cation-anion balance was varied from 327 to 700 meq/kg and electrolyte balance, from -29 to 553 meq/kg. Results showed that total dietary cation-anion balance did not describe the growth of chickens as well as electrolyte balance. Low (less than 180 meq/kg) or high (greater than 300 meq/kg) electrolyte balance in a diet led to depressed liveweight at 42 d of age. There was an optimum electrolyte balance from 250 to 300 meq/kg. The extent of liveweight depression from feeding diets with an electrolyte balance greater than 300 meq/kg depended on the type of cation added to the diet (Na or K): the range of the Na:K ratio for optimum growth was 0.5-1.8. Acid-base balance was influenced mainly by a diet with a low electrolyte balance (-29 meq/kg). Plasma ion levels (Ca, inorganic P, Mg, Na, K, Cl) were unaffected by dietary treatment, except that high dietary calcium reduced plasma inorganic P levels. Increasing calcium from 1.30 to 1.74% reduced liveweight at 42 d of age by 5%, but subsequent increases up to 2.30% Ca had relatively minor effects. Liveweight tended to be lower for birds fed a diet containing 1.30% Ca and 0.81% aP compared to 0.45% aP with 1.30% Ca. Total cation-anion balance cannot be used in preference to dietary electrolyte balance to describe growth of broiler chickens. However, even though there was a good relationship between growth and dietary electrolyte balance, there were specific cation effects (Na and K) independent of electrolyte balance.

Absence of a role for selenium deficiency in the runting syndrome of broiler chickens in Australia.

The role of selenium deficiency in the etiology of the runting-stunting syndrome (RSS) of broiler chickens in Australia was investigated. Commercial broiler chickens maintained on selenium-deficient developed signs consistent with selenium deficiency of exudative diathesis and markedly reduced plasma glutathione peroxidase activity, but they did not develop pancreatic atrophy and fibrosis or elevated plasma amylase activity, which are the other lesions associated with RSS. Supplementation of the diets of birds from a RSS-susceptible flock with a mixture of selenium, vitamin E, cysteine, and sulfate had no effect on the incidence of runting in the treated birds. In field outbreaks of RSS there were no observable differences between affected and unaffected birds in the concentration of selenium in tissue samples. Furthermore, evidence is presented which suggests that in cases of RSS, pancreatic atrophy and elevations in plasma amylase precede reductions in plasma glutathione peroxidase activity.

Choice feeding of the replacement pullet on whole grains and subsequent performance on laying diets.

From 8 to 20 weeks of age crossbred pullets were offered a protein concentrate plus either wheat, millet or paddy rice as crushed or whole grain. These pullets were then fed on three laying diets which differed in either methionine content or bulk density. In the growing period pullets given whole grains were heavier, and ate more protein-concentrate and hard grit than those given crushed grains. In the laying period they matured earlier, laid more eggs and utilised food more efficiently than the others. Pullets fed on wheat consumed more hard grit and utilised food more efficiently than those given millet or paddy rice. Pullets fed on millet had a higher linoleic acid content in their livers and laid larger eggs than those reared on wheat. Pullets reared on paddy rice matured later and laid heavier eggs than those reared on wheat. Methionine content and bulk density of the laying diets had no effect on egg production.

Effect of nutrition in the rearing and laying phases on mortality and egg composition of crossbred layers.

Crossbred pullets reared on a low plane of nutrition had a lower mortality rate due to Marek's disease and lymphoid leucosis in the laying phase and had smaller livers with less fat than those reared on a high plane of nutrition. On the other hand, the addition of 0.06% methionine to the laying diet increased the incidence of deaths due to Marek's disease and lymphoid leucosis. The spleen weight of birds fed the diet supplemented with methionine was greater than that of those fed the unsupplemented diet. The source of cereals in the laying diet had no effect on mortality, but birds fed diets with barley had larger livers and spleens. The gizzards and intestinal tracts of the birds fed the diet with oats were larger than that of birds fed diets based on barley. The inclusion of 2.5% rapeseed oil in the laying diet resulted in haemorrhage of ovarian follicles and reduced the proportion of yolk in the egg.