Biomedical subjects
Publications and source records attributed to J F Kennedy.
This article challenges nurses to examine their practice and procedure when establishing enteral feeding. The author suggests that discontinuation for 'complications' such as diarrhoea may not be appropriate, and recommends that nurses take more responsibility for patient nutrition.
Developments in the solubilization of complexes between the cationic polymer, poly(hexamethylenebiguanidinium chloride) (PHMBH+Cl-) and acidic polysaccharides are reported. It was discovered that the anionic detergent sodium dodecyl sulphate (SDS) is an excellent solubilizer for these complexes, enabling several multi-component systems to be studied. SDS itself was shown to interact with PHMBH+Cl- to form a highly viscous solution. Maximum viscosity was obtained with a SDS:PHMBH+Cl- molar ratio of 15.6. SDS:PHMBH+Cl- at this ratio served as a good solubilizer for the acidic polysaccharides (sodium alginate, sodium carboxymethyl cellulose, and xanthan), forming highly viscous fluids. The effect of temperature on the viscosity of these solutions was also examined.
This paper describes the key strategic challenges facing a purchaser of health care services in central Scotland. The paper describes a number of key issues including influencing the health of the local population, the financial constraints, the development of alliances and the involvement of service users in planning. It highlights the importance of organizational development and the management of the external environment. Long-term challenges associated with the purchase of health care are suggested and the paper concludes that achieving health status targets and the desires of the local population could well conflict. It suggests that health boards/authorities will need to enhance their planning and developmental work for the future.
Porous ceramic supports have been developed and utilized for the immobilization of yeast cells to produce ethanol by the fermentation of glucose. The relationship between the porous structure of the ceramic support and the quantity of yeast cells immobilized and the production of ethanol by the fermentation have been investigated. A comparison of the properties of the ceramic supports with those of a calcium alginate gel indicated that the ceramics are the better of the two types of material and have potential for industrial application.
Glycoproteins, as a class of biomolecules, present a number of differences in structure and function from non-glycosylated proteins. This makes their purification and characterisation a potentially daunting prospect. This article provides a brief summary of the occurrence, structure and composition of glycoproteins and the main areas where these factors may complicate the purification and characterisation process. There follows a review of the range of techniques available, an insight into the choices of ways forward in considering glycoprotein purification and characterisation. Appropriate prominence is given to lectins; their application to the purification, identification and characterisation of glycoproteins, and the major contribution they have made to the study of this class of biomolecules.
High-alkaline protease (HAP) has been entrapped in Manugel DMB (an alginate gel) and assayed with two sizes and types of substrates: neutral protein casein and synthetic chromogenic tripeptide substrate, Z-Gly-Pro-Cit-PNA. Increasing the concentration of calcium chloride used for capsule formation decreased the measured enzyme activity with both substrates. Capsules were found to be stable in water for long periods of time, but they dissolved in both phosphate and carbonate-bicarbonate buffers. The pH vs activity profiles of encapsulated enzyme showed pH optima between 10 and 11 with both substrates. The calcium alginate matrix surrounding the enzyme was quite effective in stabilizing the enzyme at 20-25 degrees C and even more so at 4 degrees C. Enzyme stability at 50 degrees C was quite impressive, some enzyme activity being evident even after remaining for 1 wk at this temperature in water. Increasing concentrations of sodium dodecyl sulfate (SDS) were also found to inhibit the protease progressively, whereas a polyhexamethylene biguanidium chloride (PHMBH+Cl-) and SDS:PHMBH+Cl- combination showed the opposite effect. Optical microscopy, especially polarized light microscopy, provided a sensitive physical means of ascertaining some of the structural properties (sphericity, disorganization or organization, distinct layer enveloping the capsules, intensity of the maltese cross) of the capsules with and without enzyme before and after different chemical treatments and the presence or absence of the substrate.
This article reviews the strategies and successes of modifying enzymes by means of biophysicochemical transformations. By judicious choice of methods, it has been possible to modify enzymes through physical interactions, chemical reactions and/or mutagenesis to alter a very wide range of properties ranging from stability and solubility on the one hand to catalytic activity and selectivity on the other.
The rate of degradation of L-ascorbic acid in solution has been investigated under varying conditions, such as temperature, level of dissolved oxygen, pH, amino acids, sugars and processing conditions. Changes in pH between pH 1.5 and 7.0 accelerate L-ascorbic acid degradation. The most important factor that determines its stability is storage temperature, on which the rate of degradation of L-ascorbic acid is directly dependent. Similarly, the deleterious effect of variables such as oxygen and pH are influenced by temperature. Therefore, low temperature storage is imperative in order to regard L-ascorbic acid delay. A definite role of amino acids in L-ascorbic acid degradation has not been identified.
Explore the source record for details and available documents.
The DNA sequence coding for the merozoite protein gp195 was inserted into the vaccinia virus expression plasmid pvHAX31. This recombinant plasmid was used to integrate the gp195 DNA into the vaccinia virus genome by homologous recombination. The resulting chimeric virus was tested for gp195 expression in CV-1 cells by Western blotting. The virus that gave positive results was then grown on a large scale and used to infect rabbits. The animal antibody response towards gp195 was analysed in detail. The possibility of using gp195 as a component in a multivalent malaria vaccine is discussed.
Methods for the covalent immobilization of alpha-amylase and glucoamylase on to epoxide-, isocyanate-, acid chloride-, and carboxylic acid-activated plastic supports have been optimized. The effects of the following parameters have been examined: coupling time, pH, and temperature; availability of the free essential reacting groups on the supports; porosity of the supports; and enzyme loading. Properties of the immobilized enzymes, such as coupled activity and operational stability were assessed.
By a simple oversight, an immobilisation membrane was inserted into the holding apparatus without removal of the transit packing foam. This foam was ultimately proved to be as effective an immobilisation agent as the real membrane.
Explore the source record for details and available documents.
This review includes current information on biodegradation processes of pollutants, digestor biocenosis and bioadditives, sludge production, measurement of pollution, and advances regarding biotechnological treatment of a series of specific industrial effluents.
The covalent immobilization of alpha-amylase on new isocyanate, acid chloride and carboxylic acid--activated plastic supports shows the viability of such supports for immobilizing enzymes, especially those reacting with 1,6-diaminohexane and glutaraldehyde for producing side arms. The operational stability of immobilized alpha-amylase could be extended by crosslinking the enzyme or by extending the support's side arm (substrate concentration has no effect). Inactive immobilized alpha-amylase were unfolded and then refolded at elevated temperature, these supports were found to be essential in increasing the stability of the enzyme during refolding. The pH curves for the immobilized enzyme were in general found not to be shifted from the soluble enzyme's pH optimum, although one isocyanate plastic support derivative shifted the pH activity profile of alpha-amylase to a higher range by 1.5 pH units, probably due to reaction between the enzyme and the free anhydride groups existing on the support's surface. In all cases, the immobilized enzyme's temperature activity profiles were shifted to a lower temperature range when compared to the soluble enzyme. The immobilized alpha-amylase Michaelis constants increased and the the maximum rates and specific activities decreased when compared to the soluble enzyme kinetic parameters.
OBJECTIVE: Our objective was to evaluate the effect of controlled ovarian hyperstimulation on pregnancy rates after intrauterine insemination of washed husband's sperm. STUDY DESIGN: In a private practice setting at the Infertility, Gynecology, and Obstetrics Medical Group in San Diego, 79 treatment programs included intrauterine insemination during natural cycles, 195 included clomiphene stimulation, and 53 had human menopausal gonadotropin stimulation. Pregnancy rates and monthly fecundabilities were calculated by life-table analysis and compared by the Z test. RESULTS: By life-table analysis the cumulative probability of pregnancy after intrauterine insemination with no ovulation induction is 21.0% after six cycles with a monthly fecundability of 3.4%. With clomiphene the pregnancy rate is 32.7% with a monthly fecundability of 6.1%, and with human menopausal gonadotropin the pregnancy rate is 60.7% with a monthly fecundability of 13.0%. The human menopausal gonadotropin group had a significantly higher pregnancy rate and monthly fecundability as compared with the other two groups. There were no differences between the no-stimulation and the clomiphene groups. CONCLUSIONS: Human menopausal gonadotropin stimulation results in a significantly higher pregnancy rate and monthly fecundability after intrauterine insemination as compared with no stimulation or clomiphene use.
Explore the source record for details and available documents.
An HPLC method using a reversed-phase macroreticular PLRP-S column and phosphate buffer as eluent is described for the analysis of L-ascorbic acid degradation products, 5-hydroxymethyl furfuraldehyde and furfuraldehyde, in processed fruit juices. Measurement of the levels of 5-HMF and furfuraldehyde in citrus juices against time showed the presence of 5-HMF (0.45 mg l-1) even at zero time. An assessment on the effect of the additives on the formation of 5-HMF of reconstituted single-strength orange juice showed virtually the same results for all the samples stored at 4 degrees C and 20 degrees C, irrespective of the additive. For citrus juice samples which had been subjected to accelerated degradation, those that showed the highest decomposition of L-ascorbic acid, produced the highest level of 5-HMF. The presence of furfuraldehyde in any of the samples was not detected, probably due to the fact that furfuraldehyde was formed in such small amounts which are below the minimum detectability limit of the method (0.050 mg l-1).