Intramammary infusion of insulin or long R3 insulin-like growth factor-I did not increase milk protein yield in dairy cows

Two experiments investigated the regulation of milk protein synthesis in well-fed cows (n = 4) using 1) a hyperinsulinemic-euglycemic clamp and 2) intramammary infusion of insulin or long R3 insulin-like growth factor-I plus supplementary amino acids. In experiment 1, insulin was infused at 1.0 microg x kg BW(-1) x h(-1) to increase circulating levels fourfold, and euglycemia was maintained by infusion of glucose. An insulin clamp increased the yields of casein and whey protein both with and without supplementary amino acids. Plasma concentrations of insulin-like growth factor-I were increased and insulin-like growth factor binding protein-2 decreased during insulin clamp, while both insulin and insulin-like growth factor-I in milk were elevated by this treatment. Milk concentrations of insulin peaked on day 4, but insulin-like growth factor-I concentrations in milk peaked on day 1 of the insulin clamp. In experiment 2, intramammary infusion of insulin had no effects on any measured variables, while yields of milk, protein, and fat were slightly lower following long R3 insulin-like growth factor-I treatment. This could be associated with an increase in somatic cell count, which occurred following long R3 insulin-like growth factor-I treatment. Results from experiment 1 suggest insulin and insulin-like growth factor-I are likely candidates responsible for the increased milk protein yields during the insulin clamp. However, in experiment 2 neither hormone enhanced milk protein yield when administered using an intramammary technique.     

Effect of pH on survival, thermotolerance, and verotoxin production of Escherichia coli O157:H7 during simulated fermentation and storage

Heat treatment is increasingly being introduced to fermented meat processing, since the acid tolerance properties of Escherichia coli O157:H7 can permit this organism to survive traditional processing procedures. This study investigated the effect of growth pH and fermentation on the thermotolerance at 55 degrees C of E. coli O157:H7 in a model fermented meat system. E. coli O157:H7 (strain 380-94) was grown at pH 5.6 or 7.4 (18 h at 37 degrees C), fermented to pH 4.8 or 4.4 in brain heart infusion broth, and stored for 96 h. Cells grown at pH 5.6 had higher D values at 55 degrees C (D55 degrees C) than cells grown at pH 7.4 (P < 0.001). Cells fermented to pH 4.8 had higher D55 degrees C than those fermented to pH 4.4 (P < 0.001). Cells fermented to pH 4.8 demonstrated an increase in D55 degrees C during storage (P < 0.001), whereas cells fermented to pH 4.4 showed a decrease in D55 degrees C during the same period (P < 0.001). The effect of growth pH on verotoxin production by E. coli O157:H7 was assessed using the verotoxin assay. Cells grown at pH 5.6 had lower verotoxin production then cells grown at pH 7.4. This effect was not sustained over storage. These results indicate that a lower growth pH can confer cross-protection against heat. This has implications for the production of acidic foods, such as fermented meat, during which a heating step may be used to improve product safety.     

Using statistical process control charts for the continual improvement of asthma care

BACKGROUND: Home monitoring of lung function using simple, inexpensive tools to measure peak expiratory flow rate (PEFR) has been possible since the 1970s. Yet although current national and international guidelines recommend monitoring of PEFRs via traditional run charts, their use by both patients and physicians remains low. The role of statistical process control (SPC) theory and charts in the serial monitoring of lung function at home were explored and applied to the direct care of patients with asthma. The method represents an integration of collective professional and improvement knowledge with the related disciplines of continual improvement, SPC, system thinking/system dynamics, paradigms, and the learning community/organization. CASE STUDIES: Use of PEFR control charts for four patients cared for at the Asthma-Allergy Clinic and Research Center (Shreveport, La) is described. The key to good asthma control is the ability to optimize lung function by reducing the variation between serial lung function measurements and thereby generate a safe range of function. Knowledge of the type of variation (special cause or common cause) in the system helps in focusing clinical decision making. Case 4, an 11-year-old boy, for example, shows how control charts were used to learn the effects of a new inhaled corticosteroid. Comparison of the last 14 days of baseline and the last 14 days of open label use of the inhaled corticosteroid showed an obvious improvement in actual PEFR values--which a run chart or comparison of means would have easily demonstrated. The control chart showed that this child's care process at baseline was functionally at risk for severe asthma (46% personal best) and that the effect of the new medication not only elevated the mean function but shifted the range of function from 46%-72% personal best to 78%-102% personal best. At this new range of function the patient's system of care was not capable of delivering values that are at risk for severe asthma. Unless the range of function the change in care is capable of producing is specifically quantitated, misinterpretation of improvement data can occur. DISCUSSION: Developing the concept of the PEFR control chart involved examining and challenging traditional mental models for monitoring PEFR at home in the care of asthma, acquiring a better understanding of the workings of dynamic systems and with system thinking, and sharing what was learned with patients and seeking their input. CONCLUSIONS: The PEFR control chart employs an interesting statistical platform that enables the integration of knowledge of serial measurements and knowledge of the variation between those measurements into a tool with which to better assess the asthma care process being followed. This tool provides clinical insights, practical knowledge, and opportunities unavailable to patients and physicians via traditional PEFR charting.     

Prototypes of facial attributes developed through image averaging techniques

Image capture and quantification has proven useful in a variety of scientific applications, for example, biology, medicine, geology, meteorology and forensics. The objective of this research was to utilize this technology to quantify clinical- and consumer-perceivable changes in facial attributes. A panel of expert assessors was trained, and, in a large consumer study, consumer facial attributes were identified and grading scales for each attribute were established. These experts then rated over 240 subjects on a total of 19 different facial attributes. Based on methodology developed by Perrett et al., facial averages or prototypes were computed from panelists rated high or low for each attribute. Prototypes were developed in a 3 step process: 1) selection of 224 predefined feature points; 2) calculation of average face shape; and 3) 'morphing' individual faces into that shape and blending the images together. Naive assessors could readily appreciate the differences in facial appearance of the prototypes. In addition, expert graders were able to identify the general class of attribute affected. This method provides a powerful tool for assessing the effects of skin care technologies.     

PCR-based 16S ribosomal DNA detection technique for Clostridium estertheticum causing spoilage in vacuum-packed chill-stored beef

Chill stored vacuum-packaged meat is sometimes spoiled by psychrotrophic or psychrophilic clostridia. Clostridium estertheticum was first isolated from vacuum-packed beef from southern Africa, but has recently been found in beef originating from northern Europe. This organism is difficult to isolate using conventional methods, and two PCR-based methods have been devised for use in measures to control the bacterium in the abattoir and to study its ecology. In the first method, primers were designed having a high annealing temperature of 65 degrees C to increase specificity, producing a PCR product of 567 bp from the 16S rDNA. Two species of Enterobacteriaceae found in meat cross-reacted in this test, and so it was necessary to use a second step, digesting the PCR product with two restriction enzymes. Subsequently a further set of primers was designed, producing a PCR product of 641 bp, and using an annealing temperature of 60 degrees C. The second procedure was more specific and did not require subsequent restriction analysis of the PCR product. The two sets of primers appeared to have similar sensitivity, detecting 10-100 cells of C. estertheticum in broth, meat or meat purge (drip). A semiquantitative method is described for estimating numbers of the target bacterium.     

Noise analysis of a combined optical coherence tomograph and a confocal scanning ophthalmoscope

A fiberized optical coherence tomographic (OCT) system is modified to produce a confocal image similar to that produced by a scanning laser ophthalmoscope. Two possible configurations are presented, one that can deliver either an OCT or a confocal image and another that is capable of producing both the OCT and the confocal images simultaneously. Using the later configuration, we demonstrate such images from the retina in the living eye. The penalty in terms of performance reduction introduced into the optical coherence tomograph when integrated with a confocal receiver and the signal-to-noise ratio analysis for the different confocal receiver configurations are presented.     

Evidence that lamprey GnRH-III does not release FSH selectively in cattle

Experiments were performed to test the hypothesis that lamprey GnRH-III (lGnRH-III) selectively releases FSH. Primary cultures of bovine adenohypophyseal cells were treated with mammalian GnRH (mGnRH) and lGnRH-III (10(-9), 10(-8), 10(-7) and 10(-6) M) or control media in Experiment 1. All doses of mGnRH and the two highest doses of lGnRH-III stimulated (P < 0.001) a non-selective release of LH and FSH. In Experiments 2-4, Latin Square designs were utilized in vivo to examine whether physiological and hormonal milieu regulate putative selective effects of lGnRH-III. In Experiments 2 and 3, ovariectomized cows with basal levels of estradiol only (Experiment 2) or in combination with luteal phase levels of progester-one (Experiment 3) were injected with mGnRH and lGnRH-III (0.055, 0.11, 0.165 and 1.1 microg/kg body weight (BW) and saline. All doses of mGnRH released (P < 0.001) LH and FSH, but only the highest dose of lGnRH-III stimulated (P < 0.001) a non-selective release of both LH and FSH (Experiment 3). For Experiments 4A and 4B, intact, mid-luteal phase cows were injected with mGnRH and lGnRH-III (1.1 microg/kg BW; Experiment 4A), lGnRH-III (1.1 and 4.4 microg/kg BW; Experiment 4B) and saline. As before, mGnRH released (P < 0.001) both LH and FSH at all doses. In contrast, lGnRH-III at the highest dose released (P < 0.001) LH but not FSH. These findings suggest that lGnRH-III may act as a weak competitor for the mGnRH receptor and do not support the hypothesis that it selectively releases FSH in cattle.