Development of an improved production method, determination of protein composition, and potency characterization of Mycobacterium avium subsp. paratuberculosis purified protein derivative

Purified protein derivatives (PPDs) previously prepared by two different methods from the cultured filtrate of Mycobacterium avium subsp. paratuberculosis (MAP) ATCC strain 19698 were further characterized and compared. The traditional production method, which incorporates autoclaving prior to filtration of the culture media, was compared to a modified method that removed autoclaving during the process. PPD preparations were characterized utilizing mass spectrometry and compared for skin test responses using the guinea pig potency test. Mass spectrometry identified 131 MAP proteins among the three PPD preparations, ten of which present in all preparations. Guinea pig potency testing between PPD preparations resulted in significant difference between production lots. The overall potency of each tested lot was acceptable based upon the measured reactivity. Selected proteins identified by mass spectrometry were recombinantly expressed and purified from E. coli and evaluated by the guinea pig potency test. Seven recombinant proteins showed greater erythema as compared to the reference PPD lot 9801 in paired guinea pigs and were able to stimulate interferon gamma production from Johne’s positive animals. These results suggest that autoclaving culture suspensions is not a necessary step in PPD production and specific proteins could supplant the PPD antigen for intradermal skin testing procedures and for use as in-vitro assay reagents

Survival of Brucella abortus RB51 lyophilized and liquid vaccine at different storage conditions

http://www.worldcat.org/oclc/3970802

The New Zealand Strong Motion Earthquake Recorder Network

The network of strong-motion earthquake recorders, maintained throughout New Zealand by the Engineering Seismology Section of the Department of Scientific and Industrial Research, is described. The instruments are either deployed as ground instruments to measure potential earthquake attack on structures, or in structures, e.g. buildings, dams and industrial installations, to record structural response. Details are given of installation of instruments , maintenance, laboratory work, record retrieval and digitisation, costs and staffing for the network. Future developments mooted include an improved digitising system, the introduction of an improved version of the existing mechanical-optical instrument in 1979, and, in the long term, the introduction of an entirely new digital recorder, having an electrical output from its accelerometers, which will make possible the transmission of data by telephone or radio link

Laboratory Growth, Reproduction and Life Span of the Pacific Pygmy Octopus, Octopus digueti

Octopus digueti Perrier and Rochebrune, 1894 was reared through its life cycle at 25°C in a closed seawater system using artificial sea water. Two field-collected females produced 231 hatchlings: 193 hatchlings were groupcultured while 24 were isolated at hatching and grown individually to allow precise analyses of growth in length and weight over the life cycle. All octopuses were fed primarily live shrimps. Maturing adults fed at a rate of 4.7% of body weight per day and had a gross growth efficiency of 48%. Growth in weight was exponential for the first 72 days and described best by the equation: WW(g) = .0405e•0646t. The mean growth rate over this period was 6.4% increase in body weight per day (%/d), with no significant difference between male and female growth. From 72 to 143 days, growth was logarithmic and described best by the equation: WW(g) = (6.78 x 1O- 6) t3 .13. Females grew slightly faster than males over this growth phase. During the exponential growth phase, mantle length increased at a mean rate of 2.1% per day, declining to 1.1% per day over the logarithmic phase. No attempt was made to describe mathematically the period of declining growth rate beyond day 143. The primary causes of early mortality in group culture were escapes and cannibalism. Survival was good despite high culture density: 73% survival to date of first egg laying (day 111). Survival was better among the isolated growth-study octopuses: 88% to the date of first egg laying (day 130). Mean life span was 199 days in group-reared octopuses and 221 days in the growth-study octopuses. There was no significant difference between male and female life span. Progeny of the group culture were reared at similar stocking densities and fed predominantly fresh dead shrimp and crab meat. This diet resulted in cannibalism, with only 6% survival to first egg laying on day 128. Fecundity in this group was lower. Octopus digueti is a good candidate for laboratory culture and biological experimentation because of its small size, rapid growth, short life span, and good survival in group culture

Design and Implementation of a Fluid-Mechanical Dynamic Afterload for Use in an Isolated Heart Apparatus

An isolated heart attached to a fluid-mechanical impedance (afterload) provides a method for study of myocardial processes and pressure and flow mechanics within the heart. Afterloads currently available allow various impedance parameter settings, but they are not automatically or dynamically controlled. A dynamically controlled afterload was constructed and its suitability tested for implementation with an isolated heart apparatus. Initial work was in development of a cardiovascular model to reveal trends for aortic pressure changes with afterload parameter adjustments. The LabVIEWTM model enables simulations with open-loop windkessel-type impedances and simulations with a closed-loop circulatory model. Cataloged trends were used to guide the dynamic afterload controls, and the open-loop impedances provided methods for modeling the fluid-mechanical system. Following this work, a systems analysis tool was developed in LabVIEWTM and Matlab to enable characterization of the fluid-mechanical afterload. The program contains time-domain and spectral analyses that incorporate equal variance algorithms for the correlation analyses and averaging methods for noise reduction in the spectral analyses for stationary signals. Auto- and cross-spectral analyses were used to generate system impedance spectra from dynamic afterload simulations. The culmination of this project was construction of a fluid-mechanical dynamic afterload. The dynamic nature of the afterload involves controlled, automatic adjustment of mechanical resistance, compliance and volume elements. These adjustments in afterload cause input pulsatile pressure to match the mean and range of a reference pressure. Simulations were performed with a pulsatile pressure pump for ten reference pressures with physiologically realistic mean and range values. The dynamic afterload constrained input pressures to within plus or minus 5% of the reference values and typically settled to the targeted values in 45 - 50 cycles. Impedance spectra from the simulations provided consistent and physiologically realistic estimates of afterload parameters fitted to a four-element windkessel-type impedance. Effects of changing impedance on the mean, range and stroke volume followed anticipated trends. These tests demonstrate that the dynamic afterload exhibits the qualities necessary for implementation with an isolated heart apparatus. Furthermore, this system will enable studies both of transient behavior in the isolated heart with changing afterload and of controlled pressure characteristics from a changing input pressure source