Pathogen effects on milk yield and composition in chronic subclinical mastitis in dairy cows.

This study aimed to evaluate the effects of chronic subclinical mastitis (CSM) on milk production and component yields in dairy cows. A total of six herds located in the Midwest area of São Paulo State, Brazil were selected. Herds were visited once every 2 weeks to measure milk yield and to collect milk samples from lactating Holstein cows. Milk samples were collected at two stages (1 and 2), and each stage comprised three milk samplings. In stage 1, a total of 117 of 647 cows were diagnosed with CSM based on at least two of three repeated somatic cell counts (SCC) > 2000,000 cells/mL and positive bacterial milk culture results (BC). Cows with CSM were selected for the second stage. In stage 2, selected cows had quarter sampling aseptically collected for BC analyses prior to milking, and quarter milk yield was measured. Milk components (total protein, fat, lactose, and total solids) were measured using mid-infrared spectroscopy. Mammary quarters were considered healthy if all three repeated SCC results were ≤ 200,000 cells/mL and no bacterial growth was detected on BC. All quarters with positive bacterial growth were classified as having (non-chronic) subclinical mastitis when only one of three SCC results were > 200,000 cells/mL, and CSM when at least two of three SCC results were > 200,000 cells/mL. The effects of CSM by type of pathogen on milk and components yield were assessed using a linear mixed model. Mammary quarters with CSM caused by major pathogens had milk loss of 1.1 kg/quarter milking in comparison to healthy quarters. Milk losses were 0.8 and 1.3 kg/quarter milking when CSM was caused by Staphylococcus aureus or environmental streptococci, respectively. In addition, healthy quarters produced more milk components than quarters with CSM caused by major pathogens. Minor pathogens causing CSM (non-aureus staphylococci and Corynebacterium spp.) had no effect on milk yield. Quarters with CSM had lower milk and component yields when compared with healthy quarters. Milk losses varied according to the type of pathogen and were higher when associated with major pathogens such as S. aureus and environmental streptococci compared with healthy quarters.

Comparison of standard and on-plate extraction protocols for identification of mastitis-causing bacteria by MALDI-TOF MS.

The objective was to compare standard versus on-plate sample preparation protocols for identification of mastitis bacteria by MALDI-TOF MS. A total of 186 bacterial isolates from cows with subclinical mastitis were identified by MALDI-TOF MS after preparation using two extraction protocols. On-plate protocol was performed by applying the bacterial colony directly from the culture plate onto the plate spot. For the standard protocol, lysis of bacterial colonies using reagents was performed in a cryotube, and the resulting extract was applied onto the plate spot for analysis. The on-plate protocol showed a similar bacteria identification rate (91.4%, n = 170/186) in comparison to the standard (94.6%, n = 176/186). Identification was higher for both protocols when scores used for species-level identification (≥ 2.0) was reduced to genus-level (≥ 1.7); genus-level identification score rate increased from 94.6 to 100% when using the standard protocol, and from 91.4 to 94.6% when using the on-plate protocol. However, when compared standard (as gold standard) versus on-plate protocol, genus-level identification score rate ranged from 87.1 to 89.8%. Therefore, when the on-plate protocol fails to identify any specie, the standard extraction may be more suitable as a reference protocol for use. Strategy for increasing identification with the on-plate protocol may include upgrading the reference database library. Choice of protocol for preparation may be influenced by the bacterial type to be identified. Standard and on-plate extraction protocols of bacterial ribosomal proteins associated with MALDI-TOF MS might be alternatives to conventional microbiology methods for identification of subclinical mastitis pathogens.

Clinical guidelines on hyperlipidaemia: recent developments, future challenges and the need for an Australian review.

Large reductions in cardiovascular disease (CVD) mortality have been achieved over the last 50 years in developed countries. The health policies that have contributed so much to this success have largely been coordinated by means of expert guidelines for the management of the classic modifiable risk factors such as blood pressure, diabetes and blood lipids. National and international guidelines for lipid management have demonstrated a high degree of consistency between numerous sets of recommendations. It has been argued that some important components of the consensus that has been established over the past decade have been challenged by the latest guidelines of the American Heart Association - American College of Cardiologists (AHA-ACC). Clinicians can be reassured that continued reliance on extensive scientific evidence has reaffirmed the importance of lipid metabolism as a modifiable risk factor for atherosclerotic cardiovascular disease. On the other hand, the recent AHA-ACC guidelines suggest changes in the strategies by which metabolic risk factors may be modified. This small number of important changes should not be sensationalised because these differences usefully reflect the need for guidelines to evolve to accommodate different contexts and changing perspectives as well as emerging issues and new information for which clinical trial evidence is incomplete. This article will consider the recent policies and responses of national and supranational organisations on topics including components of CVD risk assessment, sources of CVD risk information and re-appraisal of lipid-lowering interventions. Timely review of Australian lipid management guidelines will require consideration of these issues because they are creating a new context within which new guidelines must evolve.

Travel and Health Research in Australia.

Travel and tourism is a major industry in Australia, employing 6.9% of the nation's workforce (535,600 persons) and generating AUS$46.9 billion in 1993-94.1 While economic and marketing analyses have traditionally dominated the field of tourism research in Australia, health and safety issues that impact on the business of tourism are now emerging.2 Travel medicine is still a small specialty area, though it has established a legitimate role within the tourism industry by providing services in prevention and treatment. To date, little attention has been given to empirical research, even though field studies are a critical component in the provision of accurate medical advice for patients. This paper reviews the Australian research that is available and identifies areas where further work should be conducted.

Rapid crystallization of chemically synthesized hammerhead RNAs using a double screening procedure.

To find conditions for obtaining diffraction-quality crystals of a hammerhead RNA rapidly and reproducibly, we employed a "double screening" procedure in which we screened six different RNA synthetic constructs against 48 crystallization conditions using a newly devised sparse matrix. We obtained crystals immediately and diffraction-quality crystals of the sixth RNA construct within six months of initiating the screening of additional RNA sequences. The best crystals diffract to 2.9 A resolution when flash-cooled at synchrotron X-ray sources. Solid-support chemical synthesis combined with sparse matrix screening should allow rapid production of diffraction-quality crystals of a variety of small RNAs, reducing the time commitment for initiating such crystallography projects from several years to several months. The synthetic approach also makes introduction of modified bases to prevent self-cleavage and to generate isomorphous heavy-atom derivative crystals a rapid and straightforward process.

How dangerous is that visit to the beach? A pilot study of beach injuries.

OBJECTIVE: To determine the profile of injuries sustained on a resort beach during the summer holiday period. DESIGN/SETTING: Information was gathered from patients presenting to the surf club, hospital, surgery and pharmacy with injuries sustained on or around Lorne beach, Victoria. RESULTS: 211 injuries were recorded; 37% were lacerations/cuts, 18% were rescues. Of the listed causes of injuries, 20% were from surfboards and 19% were from beach litter. CONCLUSIONS: An injury profile was developed. The patterns were used to prepare the recommendations for preventive measures.

Large benign virilizing adrenal adenoma.

The young woman described sought evaluation for infertility and was found to have virilization due to a large left adrenal tumor. Further endocrine studies confirmed a syndrome of pure virilization with normal glucocorticoid function. Resection of this apparently benign tumor resulted in regression of virilization, as well as pregnancy. Pure virilization is an unusual manifestation of benign adrenocortical tumors, and adrenal tumors of this size are most frequently malignant.

Double-blind study of guanabenz acetate in hypertensive patients.

Twenty-five patients with essential hypertension were given 50 mg of hydrochlorothiazide twice daily. Patients were randomly assigned to one of two treatment groups. The group given 6 mg of guanabenz twice daily as well as hydrochlorothiazide showed a significant decrease in systolic blood pressure in the supine, sitting, and standing positions at months 1, 2, and 3, while the diastolic blood pressure was significantly reduced in all three positions at months 1, 2, 3, and 4. In the group given placebo and hydrochlorothiazide, the mean systolic and diastolic blood pressures were significantly reduced in the standing and sitting positions at month 1 and in the standing, sitting, and supine positions at month 4. When mean systolic and diastolic blood pressures of the two groups were compared, the group treated with guanabenz and hydrochlorothiazide had significantly lower systolic and diastolic blood pressure readings in all three positions at month 2 and significantly lower standing diastolic blood pressure readings at month 3 than did the group treated with placebo and hydrochlorothiazide.