Acute phase proteins in bovine milk in an experimental model of Staphylococcus aureus subclinical mastitis

The objectives were to establish the origin of 2 acute phase proteins in milk during subclinical bovine mastitis and to characterize the relationship between those proteins in milk and blood. Haptoglobin (Hp) and mammary-associated serum amyloid A (M-SAA3) appear in milk during mastitis, whereas Hp and serum amyloid A increase in serum during mastitis. The concentrations of these proteins were determined in an experimental model using a field strain of Staphylococcus aureus to induce subclinical mastitis in dairy cows. The expression of mRNA coding for these proteins was assessed and the presence of M-SAA3 in mammary tissues was determined using immunocytochemistry. Increases of M-SAA3 and Hp in milk occurred within 12 h of Staphylococcus aureus infusion, with peak concentrations occurring 3 d after infusion of the bacteria. The increase of acute phase proteins in milk (15 h) preceded the increase in serum concentrations of both proteins (24 h). Expression of mRNA for M-SAA3 and Hp increased in both mammary and hepatic tissues 48 h after infusion of the mammary glands. In mammary tissue, the increase of M-SAA3 mRNA was greater than the increase in Hp mRNA expression, whereas in hepatic tissue, the increase in M-SAA3 mRNA was less than that for Hp mRNA. Immunocytochemistry demonstrated that M-SAA3 protein was present within secretory epithelial cells at significantly higher levels in infected mammary glands than in control tissues. These proteins, which have host defense and antibacterial activities, may play a significant role in the early response to invasion of mammary tissues by pathogenic bacteria.     

Do Grain Boundaries Affect Microwave Dielectric Loss in Oxides?

Reducing loss in microwave dielectrics is critical to improving performance in wireless communications systems. Grain boundaries in polycrystalline microwave dielectric ceramics have long been suspected of increasing dielectric loss. They are often cited as the main contributor to the observed difference in dielectric losses between single crystals and polycrystalline ceramics. The exact configuration of grain boundaries is problematic to quantify in practice and their influence on the dielectric loss difficult to distinguish from other defects such as porosity, oxygen vacancies, impurities, and dislocations. Here we measure the sensitivity of a single grain boundary in a magnesium oxide bi-crystal to the polarization of an applied microwave field as a function of temperature.     

Comparative measurements of HV impulses to evaluate different setsof response parameters

Results are reported of comparative measurements made in 14 HV (high-voltage) laboratories in ten different countries. The theory of the proposed methods of characterizing the dynamic behavior is given, and the parameters to be used are discussed. Comparative measurements made using 95 systems based on 53 dividers are analyzed. This analysis shows that many of the system now in use, even though they fulfil the basic response requirements of the standards, do not meet the accuracy requirements. Because no transfer measurements were made between laboratories, there is no way to detect similar errors in both the system under test and the reference system. Hence, the situation may be worse than reported. This has led to the recommendation that comparative measurements should be the main route for quantifying industrial impulse measuring systems     

Qualifying an impulse digitizer for measurements in HV impulsetests

A standard is being prepared for digital recorders for measurements in HV (high-voltage) impulse tests. How the main tests described in the proposed standard can be applied toward qualifying an impulse digitizer for HV impulse measurements is discussed. Experimental results from the application of these techniques to different digitizers are presented. A major problem in using digital recorders in HV laboratories is electromagnetic interference. Previous low-frequency measurements have indicated that high frequencies can be a problem. Some measurements at high frequencies are reported. The consequences of these measurements for electromagnetic compatibility are discussed     

Gallium restorative materials

A case of renal cell carcinoma that was discovered in a patient with typical acute pyelonephritis is reported. A 62-year-old woman admitted with fever and right flank pain, was diagnosed as having acute pyelonephritis. Intravenous urography showed a compressed renal pelvis and mild dilated calyces, suggesting the existence of a tumor. Computed tomography revealed a parapelvic tumor 6 cm in diameter and a small low-density area separated from the tumor in the renal parenchyma. Selective renal arteriography revealed a typical renal cell carcinoma lesion. The patient underwent right radical nephrectomy, and her postoperative course was uneventful. She has remained free of disease for 7 months.     

The turbulent diffusion of drag-reducing polymer solutions from a point source in flow through a pipe

Solutions containing salt(NaCI) were injected into water flow through a fine tube at the centre of a pipe. Tests were made to ensure that the flow was turbulent and well developed at the injection point; and that neither the injection process nor the injector caused any appreciable flow disturbance. Radial concentration profiles were measured at various downstream distances by withdrawing samples from the flow and measuring their electrical conductivity. A comparison was made between water, and aqueous solutions of polyethyleneoxide and polyacrylamide. Results for the eddy diffusivity in water agreed with those from previous investigations. Turbulent diffusivities were found to be greatly reduced in the polymer solutions (even after allowance had been made for the reduced wall shear stress) compared to the values for water alone. There were detailed differences in the effects of the two different kinds of polymer and these were attributed to their different viscoelasdc properties in the concentration ranges studied.     

Do we all face the same risk when bathing in the estuary?

With the development of coastal areas, microbial water quality is an emerging public health issue though few studies have focused on risks according to age. A survey was undertaken of faecal contamination in relation to recreational activities in the Peel Harvey estuarine system, Western Australia. Levels of exposure to contaminated water were estimated though social surveys. Follow-up was also conducted to estimate the incidence of disease associated with bathing in the estuary. Pathogen levels exceeded the guideline values recommended by the World Health Organisation (WHO) at most locations throughout the year. The social survey provided information about exposure of the population in age groups. Only 31% of the recreational users belonged to the healthy adult group upon which the WHO quantitative microbial risk assessment model is based. A correlation was established between microbial water quality and incidence of respiratory diseases for children as well as for adults. Exposure to recreational water increased the incidence of respiratory illnesses for the whole population almost by a factor 2. Behaviours which resulted in increased exposures were associated with increased incidence of illnesses were observed, particularly among children aged 11-15 yr, who exhibited the highest odd ratio (OR 4.23 [2.44-6.01], CI 95%, p=0.05). There is a need for combining epidemiology studies with risk assessment processes and complementing them with social surveys for understanding the risk of recreational activities to public health.     

Associations with home hemodialysis modality failure and mortality

Background: Limited data exist on risk factors for home hemodialysis (HH) failure and mortality. We sought to determine whether age, helper status, or ethnicity was associated with home dialysis failure or mortality. Methods: We conducted a retrospective cohort study of all prevalent and incident patients from a regional dialysis unit who initiated HH training from December 2000 to September 2002. Baseline demographics, program entry and exit dates, and mortality were ascertained. Characteristics of those more likely to remain in the program were assessed using logistic regression; survival was determined using Cox proportional hazards models. Results: Of the 1117 patients enrolled for dialysis, 116 patients were trained in the HH program (6.8%). Of those, 45.7% remained in the program, 10.3% received a transplant, 10.3% returned to in‐center dialysis, 1.7% were lost to follow‐up, and 31.7% expired. Compared to patients who returned to center or received a transplant, patients who remained on HH were more likely to be older, to have been on dialysis longer, and to have diabetes as their primary renal disease. Ethnicity, sex, or type of helper did not affect home program status. Among those who remained in the HH program, those with hypertension or other renal diseases had better survival than those with diabetes, as did those who had related helpers compared to those with unrelated helpers. Conclusions: Older and younger ages, but not ethnicity, helper status, or sex, were associated with home dialysis failure. Diabetes remained an independent risk factor for increased mortality. HH remains a viable option for many patients.