Bacteriology of butter IV. Bacteriological studies on surface taint butter

1. The surface taint butter examined often contained large numbers of bacteria, as determined by the plate method, and with some of the samples the counts were very high; with a few samples the counts were comparatively low. The counts were higher on the surface portion of a sample than on the interior portion in all but 1 of 20 comparisons. 2. The surface taint butter examined usually contained large numbers of yeasts, with the surface portion of a sample commonly containing a larger number than the interior portion; the butter showed some mold counts that were high and a few that were surprisingly high, the counts on the surface portion generally being higher than on the interior portion. 3. The general types of bacteria found in surface taint butter by picking colonies into litmus milk from beef infusion agar plates were essentially the same as those found in any lot of butter containing considerable numbers of organisms. 4. Surface taint could not be produced in butter by inoculating a normal product, either salted or unsalted, with surface taint butter but could be developed by inoculating the defective butter into pasteurized cream and churning the cream; from 2 to 4 days were required for the surface taint to develop at 15.6°C. (60°F.) and from 7 to 10 days at 5°C. (41°F.). 5. Surface taint sometimes developed in commercial butter held at temperatures very favorable for bacterial growth; in most cases the butter that developed surface taint was unsalted or had a low salt content. 6. Excessive numbers of organisms were found when either experimental or commercial surface taint butter was examined microscopically. 7. The organisms which predominated on beef infusion agar plates poured with surface taint butter did not produce surface taint when inoculated into pasteurized cream and the cream churned. 8. An organism capable of producing surface taint when inoculated into pasteurized cream and the cream churned was first isolated from a sample of Canadian butter by plating on beef infusion agar and picking colonies into litmus milk; at the time of the appearance of surface taint in experimental butter the numbers of organisms per milliliter, as determined by the plate method, were comparatively small. The organism was believed to be an undescribed species and was tentatively designated Achromobacter putrefaciens. 9. By the use of an enrichment method consisting of inoculating butter into litmus milk, holding this at 5°C. (41°F.) and then plating on beef infusion agar and picking colonies into litmus milk, A. putrefaciens was secured from five additional samples of surface taint butter, three from Canada and two from the United States. From a considerable number of surface taint samples A. putrefaciens could not be secured. 10. Organisms, other than A. putrefaciens, which would produce surface taint were isolated from a number of samples of surface taint butter. These organisms were always found in small numbers. 11. Organisms which would produce surface taint were isolated from a total of 17 samples of commercial surface taint butter, 6 from Canada and 11 from the United States. 12. Organisms capable of producing surface taint could not be isolated from a considerable number of samples of surface taint butter, although with some of the samples the defect could be carried through a series of experimental churnings by using defective butter to inoculate the cream. 13. The organisms which would produce surface taint were greatly restrained by the use of medium salt percentages or butter culture in the making of butter. A. putrefaciens failed to grow in skimmilk acidified with lactic acid to 0.30 or 0.31 percent but did develop when the milk was acidified to 0.27, 0.28 or 0.29 percent. 14. In the trials carried out with Ps. fluorescens by inoculating pasteurized cream and churning the cream, rancidity regularly developed. 15. There appeared to be rather distinct variations in the samples of butter sent to the laboratory as examples of surface taint

The incidence of breast cancer in the General Practice Research Database compared with national cancer registration data

Breast cancer incidence rates in the UK from 1990 to 1996 among women aged 35–69 estimated from the General Practice Research Database (GPRD) were closely similar to those reported by the Office for National Statistics from cancer registration data (ONS). The GPRD is a valuable and up-to-date resource for further study of the incidence of breast cancer in the UK as well as changes in cancer treatment and their relation to survival trends. © 2000 Cancer Research Campaign http://www.bjcancer.co

Application of Newtonian physics to predict the speed of a gravity racer

Gravity racing can be studied using numerical solutions to the equations of motion derived from Newton’s second law. This allows students to explore the physics of gravity racing and to understand how design and course selection influences vehicle speed. Using Euler’s method, we have developed a spreadsheet application that can be used to predict the speed of a gravity powered vehicle. The application includes the effects of air and rolling resistance. Examples of the use of the application for designing a gravity racer are presented and discussed. Predicted speeds are compared to the results of an official world record attempt

Thyrotropin-releasing hormone (TRH) promotes wound re-epithelialisation in frog and human skin

There remains a critical need for new therapeutics that promote wound healing in patients suffering from chronic skin wounds. This is, in part, due to a shortage of simple, physiologically and clinically relevant test systems for investigating candidate agents. The skin of amphibians possesses a remarkable regenerative capacity, which remains insufficiently explored for clinical purposes. Combining comparative biology with a translational medicine approach, we report the development and application of a simple ex vivo frog (Xenopus tropicalis) skin organ culture system that permits exploration of the effects of amphibian skin-derived agents on re-epithelialisation in both frog and human skin. Using this amphibian model, we identify thyrotropin-releasing hormone (TRH) as a novel stimulant of epidermal regeneration. Moving to a complementary human ex vivo wounded skin assay, we demonstrate that the effects of TRH are conserved across the amphibian-mammalian divide: TRH stimulates wound closure and formation of neo-epidermis in organ-cultured human skin, accompanied by increased keratinocyte proliferation and wound healing-associated differentiation (cytokeratin 6 expression). Thus, TRH represents a novel, clinically relevant neuroendocrine wound repair promoter that deserves further exploration. These complementary frog and human skin ex vivo assays encourage a comparative biology approach in future wound healing research so as to facilitate the rapid identification and preclinical testing of novel, evolutionarily conserved, and clinically relevant wound healing promoters

Three dimensional ink-jet printing of biomaterials using ionic liquids and co-solvents

1-Ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]) and 1-butyl-3-methylimidazolium acetate ([C4C1Im][OAc]) have been used as solvents for the dissolution and ink-jet printing of cellulose from 1.0 to 4.8 wt%, mixed with the co-solvents 1-butanol and DMSO. 1-Butanol and DMSO were used as rheological modifiers to ensure consistent printing, with DMSO in the range of 41–47 wt% producing samples within the printable range of a DIMATIX print-head used (printability parameter < 10) at 55 °C, whilst maintaining cellulose solubility. Regeneration of cellulose from printed samples using water was demonstrated, with the resulting structural changes to the cellulose sample assessed by scanning electron microscopy (SEM) and white light interferometry (WLI). These results indicate the potential of biorenewable materials to be used in the 3D additive manufacture process to generate single-component and composite materials

Are coronary event rates declining slower in women than in men – evidence from two population-based myocardial infarction registers in Finland?

<p>Abstract</p> <p>Background</p> <p>Studies have suggested that the prevention and treatment of coronary heart disease may not have been as effective in women as in men. Therefore, we aimed to examine whether the incidence, attack rate and mortality of myocardial infarction (MI) events have declined less in women than in men.</p> <p>Methods</p> <p>Two large population-based MI registers, the FINAMI register and the Finnish Cardiovascular Disease Register (CVDR) were used for comparing the event rates among men and women aged ≥35 years in two time periods, 1994–1996 and 2000–2002.</p> <p>Results</p> <p>In the FINAMI register a total of 5,252 events were recorded in men and 4,898 in women. Corresponding numbers in the CVDR were 78,709 and 70,464. Both FINAMI and CVDR data suggested smaller declines in incidence and attack rate of MI events in women than in men. In CVDR data the decline in mortality was also smaller in women than in men, while in FINAMI data this difference did not reach statistical significance. In the large CVDR data set, negative binomial regression models revealed smaller declines in incidence (p = 0.006), attack rate (p = 0.008) and mortality (p = 0.04) in women than in men aged <55 years. In persons ≥55 years no difference was observed between women and men.</p> <p>Conclusion</p> <p>The incidence and attack rate of MI events have declined less in women aged <55 than in men of similar age. In older persons no significant differences were observed. Further studies are warranted to find out the reasons why the development has been less favourable for young women than for men.</p

Supramolecular approach to new inkjet printing inks

Electronically complementary, low molecular weight polymers that self-assemble through tunable π−π stacking interactions to form extended supramolecular polymer networks have been developed for inkjet printing applications and successfully deposited using three different printing techniques. Sequential overprinting of the complementary components results in supramolecular network formation through complexation of π-electron rich pyrenyl or perylenyl chain-ends in one component with π-electron deficient naphthalene diimide residues in a chain-folding polyimide. The complementary π−π stacked polymer blends generate strongly colored materials as a result of charge-transfer absorption bands in the visible spectrum, potentially negating the need for pigments or dyes in the ink formulation. Indeed, the final color of the deposited material can be tailored by varying the end-groups of the π-electron rich polymer component. Piezoelectric printing techniques were employed in a proof of concept study to allow characterization of the materials deposited, and a thermal inkjet printer adapted with imaging software enabled in situ analysis of the ink drops as they formed and of their physical properties. Finally, continuous inkjet printing allowed greater volumes of material to be deposited, on a variety of different substrate surfaces, and demonstrated the utility and versatility of this novel type of ink for industrial applications

Osteoprotegerin: A Novel Secreted Protein Involved in the Regulation of Bone Density

AbstractA novel secreted glycoprotein that regulates bone resorption has been identified. The protein, termed Osteoprotegerin (OPG), is a novel member of the TNF receptor superfamily. In vivo, hepatic expression of OPG in transgenic mice results in a profound yet nonlethal osteopetrosis, coincident with a decrease in later stages of osteoclast differentiation. These same effects are observed upon administration of recombinant OPG into normal mice. In vitro, osteoclast differentiation from precursor cells is blocked in a dose-dependent manner by recombinant OPG. Furthermore, OPG blocks ovariectomy-associated bone loss in rats. These data show that OPG can act as a soluble factor in the regulation of bone mass and imply a utility for OPG in the treatment of osteoporosis associated with increased osteoclast activity