The effect of 2 different premilking stimulation regimens, with and without a latency period, on teat tissue condition and milking performance in Holstein dairy cows.

The objectives of this study were to assess the effect of 2 different premilking stimulation regimens, with and without a latency period between tactile stimulation and the attachment of the milking unit, on the teat tissue condition and milking performance of dairy cows. In a randomized controlled crossover study, 145 Holstein cows milked 3 times daily were assigned to treatment (TRT) or control (CON) groups. Premilking udder preparation for the TRT group consisted of the application of a latency period resulting in a preparation lag time of 90 s. The only difference in the premilking udder preparation of the CON group was the absence of latency period; the milking unit was attached immediately after completion of the tactile stimulation. The average duration of total tactile stimulation in TRT and CON group was 8 ± 2 and 9 ± 2 s, respectively. The study lasted for 14 d and was split into 2 periods, each consisting of a 2-d adjustment period followed by 5 d of data collection. We assessed machine milking-induced short-term changes to the teat tissue by palpation and visual inspection postmilking. Electronic on-farm milk meters were used to assess milking characteristics (milk yield [kg/milking session], machine-on time [s], 2-min milk yield [kg], and duration of low milk flow rate [s]). Generalized linear mixed models were used to analyze the effect of treatment on the outcome variables. The odds of machine milking-induced short-term changes to the teat tissue were lower for cows that received a 90-s preparation lag time (TRT cows) compared with cows in the CON group (odds ratio [95% confidence interval; 95% CI] = 0.13 [0.08-0.20]). The least squares means (95% CI) values of cows in the TRT and CON groups were 15.4 (14.9-15.9) and 15.3 (14.8-15.8) kg, respectively, for milk yield, and 246 (239-253) and 253 (247-260) s for machine-on time. The 2-min milk yield was higher for the TRT compared with CON group cows at all the parity levels. The 2-min milk yields of animals in lactation 1, 2, and ≥3 were 5.7, 5.7, and 6.5 kg, respectively, in the TRT group and 4.6, 5.0, and 5.9 kg in the CON group. The TRT cows spent less time in low milk flow rate compared with CON cows at all parity levels. The durations of low milk flow rate of cows in lactation 1, 2, and ≥3 in the TRT group were 19, 17 and 13 s, respectively, and those in the CON group were 31, 22, and 15 s. In this study, cows that received a latency period, and thus were subjected to a 90-s preparation lag time had lower odds of exhibiting short-term changes to the teat tissue after machine milking, shorter machine-on time, higher 2-min milk yields, and lower durations of low milk flow rates. We conclude that consideration of latency period leading to a 90-s preparation lag time in the premilking stimulation regimen facilitated cows' milk-ejection reflex. This latency period can alleviate the adverse effects of vacuum-induced forces on teat tissue during machine milking, improve udder health, and promote animal well-being.

A randomized controlled trial to study the effects of an automated premilking stimulation system on milking performance, teat tissue condition, and udder health in Holstein dairy cows.

The objectives were to examine the effect of an automated premilking stimulation (APS) by means of a high pulsation frequency (300 cycles/min) without a reduction of the vacuum in the pulsation chamber or claw piece on (1) milking performance, (2) teat tissue condition, and (3) udder health in dairy cows. In a randomized controlled field study, Holstein cows (n = 427) from 1 commercial dairy farm with a milking schedule of 3 times per day were assigned to treatment and control groups over a 90-d period. Treatments consisted of a maximum of 80 s (APS80) or 99 s (APS99) of mechanical stimulation at a pulsation rate of 300 pulses per minute and a ratio of 25:75 (no reduction of the pulsation chamber or milking vacuum). Cows in the control group (CON) received traditional premilking stimulation by means of manual forestripping for 8 s. Milking characteristics were documented with on-farm milk meters. Short- and long-term changes in teat tissue condition induced by machine milking were assessed visually on a weekly basis. Composite milk samples were analyzed once per month to determine somatic cell count. Generalized linear mixed models were used to study the effect of the treatment on the outcome variables. We observed no meaningful differences in milk yield or milking unit-on time. Least squares means and their 95% confidence intervals (95% CI) for cows in the APS80, APS99, and CON groups were 13.5 (13.1-14.0), 13.2 (12.8-13.7), and 13.2 (12.8-13.7) kg for milk yield and 222 (213-231), 219 (210-228), and 223 (214-232) s for milking unit-on time, respectively. The effect of treatment on bimodality was modified by milk yield such that the odds of bimodality increased in the treatment groups with increasing milk yield. Compared with cows in the CON group, the odds ratios (95% CI) of bimodality were 1.08 (0.62-1.89) in the APS80 group and 0.89 (0.55-1.42) in the APS99 group at a milk yield of 11 kg and 2.0 (1.24-3.22) in the APS80 group and 2.08 (1.29-3.35) in the APS99 group at a milk yield of 16 kg. We observed differences in short- and long-term changes in teat tissue condition between the treatment and control groups. Compared with cows in the CON group, the odds (95% CI) of short-term changes were 1.87 (1.35-2.58) for the APS80 group and 1.49 (1.08-2.07) for the APS99 group, and the odds of long-term changes were 1.52 (1.24-1.85) for cows in the APS80 group and 1.59 (1.31-1.94) for cows in the APS99 group. The least squares means (95% CI) for somatic cell counts (log10-transformed) were 4.74 (4.68-4.81) for the APS80 group, 4.77 (4.71-4.83) for the APS99 group, and 4.79 (4.73-4.86) for the CON group. We conclude that the APS system tested here had no negative effects on milk yield or milking unit-on time. However, differences in bimodality and teat tissue condition suggest that the APS system did not provide sufficient stimulation to facilitate a gentle milk harvest and adversely affects teat tissue condition.

A randomized controlled trial assessing the effect of intermittent and abrupt cessation of milking to end lactation on the well-being and intramammary infection risk of dairy cows.

The objectives were to compare the effects of an intermittent milking schedule with a thrice daily milking schedule during the final week of lactation on the well-being, udder health, milk production, and risk of culling of dairy cows. We hypothesized that cows subjected to an intermittent milking schedule would experience less udder engorgement and pain, lower concentrations of fecal glucocorticoid metabolites (11,17-dioxoandrostanes; 11,17-DOA concentration) after dry-off, lower risk of an intramammary infection during the dry period, higher milk production and lower somatic cell count in the subsequent lactation, and lower culling risk compared with herd mates milked 3 times daily and dried off by abrupt cessation. In a randomized controlled field study, Holstein cows (n = 398) with a thrice daily milking schedule were assigned to treatment and control groups. The treatment consisted of an intermittent milking schedule for 7 d before dry-off (gradual cessation of milking, GRAD). Gradual-cessation cows were milked once daily until the day of dry-off, whereas cows in the control group (abrupt cessation of milking, APT) were milked 3 times daily until the day of dry-off. Udder firmness and pain responses of the udder 3 d after dry-off, as well as the percentage change in fecal 11,17-DOA concentration (3 d after dry-off compared with the dry-off day), were used to assess the well-being of the animals. Compared with cows in the GRAD group, the odds [95% confidence interval (CI)] of udder firmness were 1.55 (0.99-2.42) for cows in the APT group, and the odds of a pain response were 1.48 (0.89-2.44) for cows in the APT group. The least squares means (95% CI) of the percentage change in 11,17-DOA concentration were 129.3% (111.1-150.4) for the APT group and 113.6% (97.5-132.4) for the GRAD group. Quarter-level culture results from the periods before dry-off and after calving were compared, to assess the likelihoods of microbiological cure and new infection. Cows in the APT group had lower odds of a new intramammary infection in the dry period [odds ratio, 95% CI: 0.63 (0.37-1.05)], whereas we observed no meaningful differences in the microbiological cure likelihood among groups. The least squares means (95% CI) for somatic cell counts (log10-transformed) were 4.9 (4.8-5.0) in the APT group and 4.9 (4.8-5.0) in the GRAD group. The odds (95% CI) of clinical mastitis in the first 30 d postcalving were 1.32 (0.53-3.30) in the APT group compared with the GRAD group. We observed no meaningful differences in milk production at the first test date postcalving or the culling risk among groups. We conclude that the gradual-cessation protocol tested herein failed to significantly improve animal well-being, udder health, milk production, and survival in the tested study cohort. However, the observed differences in udder firmness, as well as the numerical differences in udder pain and the percentage change in fecal 11,17-DOA concentrations suggest that this line of research may be useful. Future research is needed to develop drying-off strategies that are appropriate for lowering milk production at the end of the lactation and improve animal well-being without compromising udder health.

The effect of 2 different premilking stimulation regimens, with and without manual forestripping, on teat tissue condition and milking performance in Holstein dairy cows milked 3 times daily.

The objectives were to study the effect of 2 different premilking stimulation regimens, with and without manual forestripping, on teat tissue condition and milking characteristics in dairy cows. In a randomized controlled crossover study, 130 Holstein cows milked 3 times daily were assigned to treatment and control groups. Premilking udder preparation for the treatment group consisted of: (1) predipping with 1% iodine, (2) sequential forestripping of 3 streams of milk per quarter, (3) wiping of teats, and (4) attachment of the milking unit. Premilking udder preparation for the control group was identical except that the forestripping step was omitted. The mean tactile stimulation durations were 16 s and 7 s for the treatment and control group, respectively. The time spent from first tactile stimulus (either forestripping or wiping of teats) to milking unit attachment was kept consistent at 90 s for both groups. The study lasted for 14 d with 2 periods, each consisting of a 2-d adjustment time followed by 5 d of data collection. Machine milking-induced short-term changes to the teat tissue were assessed by palpation and visually. The following milking characteristics were assessed with electronic on-farm milk meters: milk yield (MY), milking unit-on time (MUOT), 2-min MY (2MIN), and time spent in low milk flow rate (LMF). Generalized linear mixed models were used to describe the effect of treatment on the outcome variables. The odds of machine milking-induced short-term changes to the teat tissue were lower for cows that received forestripping compared with cows that were not forestripped (odds ratio = 0.31; 95% confidence interval = 0.22-0.42). Least squares means (95% confidence interval) for cows that were forestripped and animals that were not forestripped, respectively, were 12.7 (12.2-13.2) and 12.7 (12.2-13.2) kg for MY and 6.1 (5.8-6.4) and 5.6 (5.3-5.9) kg for 2MIN. There was an interaction between treatment and MY for LMF. Time spent in LMF for cows that were forestripped and received no forestripping, respectively, were 18 (17-20) and 24 (23-26) s for a MY level of 10 kg; and 13 (12-14) and 15 (14-16) s for a MY level of 15 kg. The effect of treatment on MUOT was modified by parity. Milking unit-on times for animals in first, second and third or greater lactation, respectively, were 230 (219-243), 249 (236-262), and 260 (249-272) s for cows that were forestripped, and 245 (232-258), 252 (239-266), and 268 (257-281) s for cows that received no forestripping. In this study, cows that were forestripped had shorter MUOT, higher 2MIN, lower LMF, and lower odds of exhibiting changes to the teat tissue after machine milking. We conclude that wiping of teats during premilking udder preparation alone and omitting forestripping of teats without compensating for the loss in stimulation time may not provide sufficient tactile stimulation to elicit the cows' maximum physiological milk-ejection capacity. This can aggravate the adverse effects of vacuum-induced forces on teat tissue during machine milking, diminish animal well-being, and possibly affect udder health.

Parathyroid hormone as a marker for metabolic bone disease of prematurity.

OBJECTIVE: To compare parathyroid hormone to alkaline phosphatase as a serologic marker for metabolic bone disease (MBD) in preterm infants. STUDY DESIGN: An 18-month prospective observational study in neonates with birth weight < 1250 g. Simultaneous serum parathyroid hormone (PTH), alkaline phosphatase (ALP), calcium (Ca) and phosphorus (P) were measured at scheduled intervals during hospitalization. At 6 weeks of age, MBD was evaluated using knee radiographs. Comparisons were analyzed using multivariate logistic regression, receiver operating characteristic (ROC) curves, χ² and Student t-test. RESULT: Fourty-nine infants were included in the study: 7 with severe and 42 with mild MBD. Using ROC curves, at 660 U l⁻¹ ALP had a sensitivity of 29% and specificity of 93% for severe MBD, while a cutoff point of 180 pg ml⁻¹ gave PTH a sensitivity of 71% and specificity of 88%. Infants with severe bone disease had a lower birth weight, 21-day serum P, an increased use of glucocorticoids and caffeine, and more likely to have major neonatal morbidities. CONCLUSION: PTH is an early marker with better sensitivity than ALP in screening for MBD. At 3 weeks chronologic age, a PTH level > 180 mg dl⁻¹ or a P level <4.6 pg ml⁻¹ yielded a sensitivity of 100% and specificity of 94% for severe MBD [corrected].

In-vitro evaluation of a polyurethane compliant-layer glenoid for use in shoulder arthroplasty.

A polyurethane glenoid component has been designed and manufactured as part of a total shoulder arthroplasty (TSA) system based on compliant-layer (CL) technology. Compared with conventional TSA designs, this biomimetic approach offers reduced friction and wear and potentially improved longevity. In-vitro evaluation of the glenoid system has included loosening and stability tests, and wear measurement using a specially constructed wear simulator. The results obtained support the hypothesis that a CL glenoid design may provide improved resistance to dynamic loosening and rim erosion, and demonstrate superior wear performance over a standard ultra-high molecular weight polyethylene design. This study not only confirms the feasibility of a CL glenoid component but also highlights the potential to increase implant longevity, thereby allowing earlier surgical intervention before poor glenoid bone stock and soft tissue compromise the outcome of TSA.

Automated in-vitro testing of orthopaedic implants: a case study in shoulder joint replacement.

This investigation presents the design and preliminary validation of a single station simulator with biaxial motion and loading designed to mimic the kinematics of the glenohumeral joint during arm abduction in the scapular plane. Although the design of the glenoid holder allows the glenoid component to translate in all three axes, it is primarily loaded axially, which brings it into contact with the oscillating humeral head, but is also loaded superiorly to simulate common subluxation of the humeral head. Simulating arm abduction in the scapular plane simplifies component alignment and removes the need for anterior-posterior loading, thereby creating a stable joint without the need to simulate capsular constraints. In this more physiologically accurate simulator design, the load and motion profiles influence the contact kinematics, but the wear path is ultimately determined by the conformity and constraint designed into the bearing couple. The wear data are determined and correlated with clinically retrieved glenoid components, as well as previously reported in-vitro studies, thus verifying use of the simulator in testing alternative materials and designs. The key design features, as well as the improvements proposed through this study, can be incorporated into the design of test fixtures for any other orthopaedic implant such as the hip, knee, spine, elbow, and finger.

Characterisation of Bionate polycarbonate polyurethanes for orthopaedic applications.

Two polycarbonate polyurethanes, Bionate 75D and Bionate 80A, have been characterized for application in biomimetic joint replacement systems. Procedures involved measurement of the effects of compounding and moulding on molecular weight, melt rheometry, and mechanical testing using conditioned and aged specimens. The effects of compounding with hydroxyapatite and carbon fibres were also evaluated. With Bionate 75D moulding reduces the molecular weight by 30%. Passing the material through a twin screw extruder without filler has similar molecular weight reduction effects to injection moulding. Inclusion of carbon fibre has little additional effect on molecular weight, although moulding of the fibre filled compound causes some further degradation, and Mw is almost halved compared with the original value. Inclusion of hydroxyapatite reduces Mw in a moulded component to less than a quarter of the original value and some form of chemical interaction between the polymer and filler is presumed. The apparent melt viscosity of the Bionate 75D was reduced by the addition of both carbon fibres and hydroxyapatite and this is thought to arise from reduction in molecular weight during the compounding process and the development of shear planes at the polymer-filler interface. The polymer glass transition temperatures are shifted to slightly higher values by the inclusion of filler. The tensile test results show the reinforcing effect of the carbon fibres, but poor wetting and pull out of the fibres was evident. Water absorption results suggest that the materials stabilise after 2 weeks, but the tensile results indicate that property change occurred between 1 month and 5 months of exposure. However the shape of the stress-strain curves is not altered, but with extended water exposure is translated to lower stress levels.

Improved growth and decreased morbidities in <1000 g neonates after early management changes.

OBJECTIVE: To test the hypothesis that three changes in the early management of extremely low birth weight (ELBW) neonates would decrease the incidence of extra-uterine growth restriction (EUGR) by 25%. The three early management practice changes (EMPC) included surfactant at delivery followed by immediate extubation to nasal continuous positive airway pressure (CPAP), decreased oxygen exposure and early parenteral amino acids. STUDY DESIGN: Historical cohort study of preterm infants

The role of occupational and environmental exposures in the aetiology of acquired severe aplastic anaemia: a case control investigation.

Aplastic anaemia is a rare but serious disorder with a high morbidity and mortality rate. The causes of aplastic anaemia are, for the most part, unknown. We report on the hypothesis that aplastic anaemia may be caused by occupational and/or environmental exposures to certain chemicals. The UK Aplastic Anaemia Study was an interview-based case-control study covering the whole of Great Britain. Those patients diagnosed between 1 July 1993 and 20 October 1997, aged < or =75 years and born and diagnosed in the UK were eligible for the study. Two hundred eligible cases of aplastic anaemia were compared with 387 age- and sex-matched controls. A number of occupational exposures showed increases in risk. In a multivariate model of these exposures the odds ratios (ORs) for solvents/degreasing agents, pesticides and radiation were >2 and statistically significant. Reported chemical treatment of houses within 5 years of diagnosis had a significantly raised risk for adults [OR = 2.51, 95% confidence interval (CI) 1.02-12.01], particularly for woodworm treatment (OR = 5.1, 95% CI 1.5-17.4). This study identified significant risks associated with self-reported exposure to solvents, radiation and pesticides in the workplace. Self-reported chemical treatment of houses was also associated with an increased risk of developing aplastic anaemia, in keeping with previous literature.

Abnormal cytogenetic clones in patients with aplastic anaemia: response to immunosuppressive therapy.

We report the response to immunosuppressive therapy with antithymocyte globulin (ATG) and cyclosporin or oxymetholone in 13 cases of aplastic anaemia (AA) with an abnormal cytogenetic clone detected at or sometime after diagnosis. Blood and bone marrow examination showed no distinctive morphological features of myelodysplasia (MDS) at diagnosis. Haematological response occurred promptly in eight cases; the remainder responded after additional immunosuppression with or without oxymetholone. Three patients had a late relapse of AA, treated successfully by allogeneic bone marrow transplantation in one; the others responded to oxymetholone. Transformation to MDS or acute leukaemia was not observed after a median follow-up of 4.1 years (range 1.2-11.2). In four patients the cytogenetic clone disappeared after treatment.

Acute and chronic increases in excitability in rat hippocampal slices after perinatal hypoxia In vivo.

We have previously shown that hypoxia induces both acute and chronic epileptogenic effects that are age dependent. Global hypoxia (3-4% O2) induces seizure activity in the developing brain [postnatal day (P)10-12] but not at younger or older ages. Adult rats with prior seizures induced by hypoxia at P10 show increased seizure susceptibility to chemical convulsants compared with controls. In the present study, we tested the hypothesis that acute and chronic epileptogenic effects of hypoxia are demonstrable in hippocampus both in vivo and in vitro. Depth electrode recordings confirmed the presence of ictal activity within hippocampus in P10 rats during global hypoxia. Hippocampal slices prepared from P10 pups killed at 10 min after recovery from hypoxia showed evidence of increased excitability. Extracellular field recordings revealed that the amplitude and duration of long-term potentiation (LTP) was increased significantly in area CA1 of hippocampal slices removed from hypoxic pups. In addition, extracellular recordings within areas CA1 and CA3 showed significantly longer afterdischarge durations in response to kindling stimuli in slices from hypoxic pups compared with controls. To evaluate whether there were also long-term changes in hippocampal excitability, hippocampal slices were prepared from adult rats that had underwent hypoxia at P10 and compared with slices from adult litter-mate controls. A Mg2+-free medium was superfused to induce epileptiform activity within the slices. Extracellular recordings from stratum pyramidale of area CA1 showed that Mg2+-free media induced significantly more frequent ictal discharges in slices from previously hypoxic rats compared with controls. These results provide evidence that the naturally occurring stimulus of hypoxia can result in both acute and chronic changes in the excitability of the CA1 neuronal network. These results parallel our previous in vivo studies demonstrating that global hypoxia acutely increases excitability in the immature brain and that hypoxia during the age window approximately P10 results in long-lasting increases in seizure susceptibility within hippocampus. Our results suggest that the age-dependent epileptogenic effects of hypoxia are in part mediated by a direct and permanent effect on neuronal excitability within hippocampal neuronal networks.

Case management: past, present, future--the drivers for change.

Case management has become a commonly used tool in the age of managed care. Case management is especially valuable when combined with demand management, disease management, and computerized information systems. This article presents a model that outlines each of these within the continuum of care.

Epidemiological typing of coagulase-negative staphylococci from nosocomial infections.

Biotyping, antibiograms, bacteriophage typing, plasmid profile analysis and SDS-PAGE protein profiles were used to determine the relatedness of 44 Staphylococcus epidermidis and four S. haemolyticus isolates from 14 patients. A selection of these were further characterised by ribotyping. Biotyping classified the isolates into three major groups but was considered a poor strain marker. Although antibiograms classified the S. epidermidis isolates into 20 groups, some changes in the susceptibility patterns of related isolates from a single patient were demonstrated. Bacteriophage typing was the least discriminatory of the methods used. SDS-PAGE gave highly related patterns for the majority of S. epidermidis isolates. Plasmid profile analysis and ribotyping, with a minimum of two restriction endonucleases, were the most discriminatory methods for typing S. epidermidis. Nonetheless, some isolates from the same patient - probably representing a single strain - varied in plasmid profile indicating plasmid instability. One of six related isolates from a single patient lacked two bands from the ribotyping pattern of the other isolates. Although no single method proved entirely satisfactory on all occasions, the combination of typing methods was sufficient to provide evidence of the relatedness of S. epidermidis isolates from individual patients.

Coordinating physical and behavioral healthcare services for Medicaid populations: issues and implications in integrated and carve-out systems.

A history of government-funded health and behavioral health services has resulted in separate and parallel systems of care for Medicaid beneficiaries. Accountability for coordination of medical and behavioral services has been poorly delineated, with adverse consequences for the medically indigent population. The author defines current opportunities and approaches for service coordination within the Medicaid arena.