Oestradiol measurement in women on oral hormone replacement therapy: the validity of commercial test kits

This study examined the attitudes toward breastfeeding of medical professionals working with pregnant or new mothers. Most advocated breastfeeding to mothers who had not made an infant feeding decision; fewer talked about breastfeeding during the first trimester; and many recommended that mothers supplement a breastfed infant with prepared commercial baby milk. All agreed that a mother's return to work led to early discontinuance of breastfeeding and that the family is a major influence on a mother's decision to breastfeed. To increase the prevalence of breastfeeding, the study group recommended prenatal education, participation in support groups, and promotion of breastfeeding through the media.     

Ultrafiltration and backfiltration during hemodialysis

Ultrafiltration is the pressure-driven process by which hemodialysis removes excess fluid from renal failure patients. Despite substantial improvements in hemodialysis technology, three significant problems related to ultrafiltration remain: ultrafiltration volume control, ultrafiltration rate control, and backfiltration. Ultrafiltration volume control is complicated by the effects of plasma protein adsorption, hematocrit, and coagulation parameters on membrane performance. Furthermore, previously developed equations relating the ultrafiltration rate and the transmembrane pressure are not applicable to high-flux dialyzers, high blood flow rates, and erythropoietin therapy. Regulation of the ultrafiltration rate to avoid hypotension, cramps and other intradialytic complications is complicated by inaccurate estimates of dry weight and patient-to-patient differences in vascular refilling rates. Continuous monitoring of circulating blood volume during hemodialysis may enable a better understanding of the role of blood volume in triggering intradialytic symptoms and allow determination of optimal ultrafiltration rate profiles for hemodialysis. Backfiltration can occur as a direct result of ultrafiltration control and results in transport of bacterial products from dialysate to blood. By examining these problems from an engineering perspective, the authors hope to clarify what can and cannot be prevented by understanding and manipulating the fluid dynamics of ultrafiltration.     

Double resonance probes for close frequencies

Halorhodopsin, isolated from Halobacterium salinarium cells incubated with tritiated palmitic acid, co-elutes with labeled palmitate in phenylsepharose CL-4B chromatography. Halorhodopsin-bound 3H-palmitate is not readily displaced by prolonged exposure to a large excess of detergents and by re-chromatography of radiolabeled halorhodopsin on phenylsepharose. On other hand, the association of labeled palmitate with purified halorhodopsin is not resistant to denaturation induced either by isopropanol/hexane or by SDS gel electrophoresis. We have tested the hypothesis that tightly associated palmitate is bound to halorhodopsin through a thioester bond, which is unstable in denaturing conditions. Using GC/MS, we have analysed the reaction products of native halorhodopsin with specific thioester reagents, thiols and NaBH4, which are inactive on free fatty acids. The results of this analytical approach indicate that there is no thioester bond between halorhodopsin and palmitic acid and that palmitic acid is associated with halorhodopsin as a free fatty acid.     

Design and construction of a realistic digital brain phantom

1. The effect of diltiazem on isolated sarcoplasmic reticulum (SR) from rabbit skeletal muscle was studied. To observe calcium movement into and out of the SR, a fluorescent chelate probe technique with chlortetracycline (CTC) as a reagent was employed. 2. Tris-ATP-induced calcium accumulation by the isolated SR was associated with a rise in the CTC fluorescence. The effect of ATP was dose dependent. 3. Diltiazem (6 x 10(-4)M, 2 x 10(-3)M) prevented ATP-induced calcium accumulation by the SR. 4. Addition of EGTA to the media chelates external calcium and caused calcium release that can be reversed by further addition of calcium chloride. Similarly diltiazem caused a rapid release of accumulated calcium from the SR, which is not reversed by the addition of calcium chloride. 5. It seems that the effect of diltiazem may be related to SR membrane-bound calcium being available for release.     

A new short practical quality of life questionnaire for use in head and neck oncology outpatient clinics

A new short questionnaire to assess the quality of life of head and neck patients has been designed at the University of Liverpool Head and Neck Oncology Department. The questionnaire is short, simple and can be easily completed by a patient whilst in the waiting room before consultation. It is filled in 6 months after completion of treatment and shows very good correlation with the standard long exhaustive questionnaires that are difficult to complete on every patient in a busy National Health Service clinic. The University of Liverpool questionnaire provides a simple score from 0%-100% which should prove valuable in the assessment of quality of care and help with decisions regarding treatment options in head and neck cancer patients.     

In vitro assembly of the mouse U14 snoRNP core complex and identification of a 65-kDa box C/D-binding protein

The eukaryotic nucleolus contains a diverse population of small nucleolar RNAs (snoRNAs) that have been categorized into two major families based on evolutionarily conserved sequence elements. U14 snoRNA is a member of the larger, box C/D snoRNA family and possesses nucleotide box C and D consensus sequences. In previous studies, we have defined a U14 box C/D core motif that is essential for intronic U14 snoRNA processing. These studies also revealed that nuclear proteins that recognize boxes C/D are required. We have now established an in vitro U14 snoRNP assembly system to characterize protein binding. Electrophoretic mobility-shift analysis demonstrated that all the sequences and structures of the box C/D core motif required for U14 processing are also necessary for protein binding and snoRNP assembly. These required elements include a base paired 5',3' terminal stem and the phylogenetically conserved nucleotides of boxes C and D. The ability of other box C/D snoRNAs to compete for protein binding demonstrated that the box C/D core motif-binding proteins are common to this family of snoRNAs. UV crosslinking of nuclear proteins bound to the U14 core motif identified a 65-kDa mouse snoRNP protein that requires boxes C and D for binding. Two additional core motif proteins of 55 and 50 kDa were also identified by biochemical fractionation of the in vitro-assembled U14 snoRNP complex. Thus, the U14 snoRNP core complex is a multiprotein particle whose assembly requires nucleotide boxes C and D.