Dietary consistency and the midline sutures in growing pigs.

OBJECTIVES: The purpose of this study was to investigate the effects of reduced masticatory function on midline suture growth and morphology in growing pigs. SETTING AND SAMPLE POPULATION: The sample was 20 pigs separated into two dietary groups and raised at the Department of Anthropology, Harvard University. Midline suture specimens were analyzed at the Department of Orthodontics, University of Washington. MATERIALS AND METHODS: Ten farm pigs and 10 minipigs, all male, were randomly assigned to hard (n = 9) and soft-diet (n = 11) groups. Fluorochromic mineral labels were administered to document bone apposition, and the animals were killed after 12 weeks. Undecalcified sections of the interfrontal, interparietal, internasal, and intermaxillary sutures were evaluated for bone quantity and sutural thickness, interdigitation ratio and growth rate. RESULTS: Soft-diet pigs were characterized by a slower rate of weight gain and less bone than their hard-diet counterparts. Even after correction for weight gain, soft-diet pigs had reduced suture growth rate and thickness. However, no difference in interdigitation ratio was detected between dietary groups. CONCLUSIONS: Restriction to a soft diet reduces midline suture growth and bone apposition in the growing pig.

Functional imaging of mucociliary phenomena: high-speed digital reflection contrast microscopy.

We present a technique for the investigation of mucociliary phenomena on trachea explants under conditions resembling those in the respiratory tract. Using an enhanced reflection contrast, we detect simultaneously the wave-like modulation of the mucus surface by the underlying ciliary activity and the transport of particles embedded in the mucus layer. Digital recordings taken at a speed of 500 frames per second are analyzed by a set of refined data processing algorithms. The simultaneously extracted data include not only ciliary beat frequency and its surface distribution, but also space-time structure of the mucociliary wave field, wave velocity and mucus transport velocity. Furthermore, we propose the analysis of the space and time evolution of the phase of the mucociliary oscillations to be the most direct way to visualize the coordination of the cilia. In particular, this analysis indicates that the synchronization is restricted to patches with varying directions of wave propagation, but the transport direction is strongly correlated with the mean direction of waves. The capabilities of the technique and of the data-processing algorithms are documented by characteristic data obtained from mammalian and avine tracheae.

Comparison of antifungal susceptibilities to fluconazole and voriconazole of oral Candida glabrata isolates from head and neck radiation patients.

The antifungal susceptibilities of 79 oral Candida glabrata isolates to fluconazole and voriconazole were compared. The MICs at which 90% of the isolates tested were inhibited were 1 microg of voriconazole/ml and 32 microg of fluconazole/ml. Oral C. glabrata isolates for which the fluconazole MICs are elevated are commonly those for which the voriconazole MICs are elevated, but these increases may be transient for voriconazole, as they are for fluconazole.

Molecular analysis and nematode resistance association of a polymorphism at the 5' end of the sheep IgE gene.

Previous work using Southern analysis of genomic DNA detected a polymorphism at the 5' end of the sheep and cattle IgE gene. Identical length differences found between fragments following digestion with restriction enzymes indicated that the basis for the polymorphism was an insertion/deletion event. To characterise the polymorphism, the entire cattle and sheep Cvarepsilon genes were sequenced including 668bp of 5' untranslated DNA. Sequence comparison revealed a high degree of similarity between the ovine and bovine genes at both the nucleotide and amino acid level. A feature of the 5' untranslated DNA was the presence of an 87bp repeat starting at -365 upstream of the Cvarepsilon start site. PCR primers were designed to span most of the 5' untranslated sequence, including the repeat unit, and used to amplify genomic DNA from a panel of 40 sheep. Three alleles were found with frequencies of 0.7, 0.29, 0.01 which were identical to the Southern analysis results. Sequencing of the two commonest alleles revealed the basis for the polymorphism was a 36bp deletion from the 87bp repeat. Association studies in a sheep selection flock phenotypically assessed for parasite resistance found a highly significant association between one of the IgE alleles and resistance to the intestinal nematode parasite Trichostrongylus colubriformis (P=0.005). Attempts to confirm this finding in two other flocks using linkage analysis and genotype association failed to find any significant associations between the IgE polymorphism and resistance to either T. colubriformis or Haemonchus contortus.

Integrating clinical reasoning and evidence-based practice.

Evidence-based practice involves basing clinical decisions and practice on the best available evidence. What do nurses need to think about when seeking to pursue evidence-based practice? What challenges do practitioners face in blending clinical reasoning with evidence-based practice? In this article, the authors argue against basing clinical practice on narrow definitions of evidence, relying solely on experimental findings or, even more exclusively, on randomized controlled trials. Instead of defining best practice narrowly by the strength of the current empirical evidence used to guide clinical decisions, it should be defined broadly by what is the best information to use to make decisions for a given patient in a particular setting. Credible and accountable clinical decisions rely on a number of forms of knowledge and evidence. This evidence includes findings from across the range of research methods, including experimental, interpretive, and action research. In nursing, it also includes evidence that has arisen from the depth of practice knowledge of expert clinical nurses. Professionals, particularly advanced and expert clinicians such as critical care nurses, use clinical reasoning to guide their practice in the uncertainty of clinical practice contexts. This reasoning helps the nurse make judgments about the relevance of particular research and clinical evidence for a specific patient and setting.

A clinical evaluation of the effectiveness of including fluoride into an orthodontic bonding adhesive.

A clinical trial was undertaken to assess the value of incorporating fluoride released from a commercially available bonding adhesive (Rely-a-Bond) to determine the extent of any protection provided against enamel decalcification. Fifty patients undergoing fixed appliance therapy were included in the trial. Contralateral quadrants were used as controls where no fluoride was present in the adhesive. Enamel decalcification after treatment and bond failure rates during treatment were investigated. A total of 366 experimental and 371 control teeth were included in the study. The results showed that 50 per cent of patients and 13.5 per cent of teeth exhibited post-treatment decalcification. The addition of fluoride to the adhesive did not significantly reduce the incidence of enamel decalcification. Bond failure rates were satisfactory for both experimental and control teeth (all under 5 per cent).

Polymerase chain reaction amplification of two polymorphic simple repeat sequences within the von Willebrand factor gene: application to family studies in von Willebrand disease.

We have used the polymerase chain reaction to amplify two variable number of tandem repeats (VNTRs) within a region of repetitive DNA located in intron 40 of the von Willebrand factor (vWf) gene. Heterozygosity for VNTR I was observed in 30 out of 39 normal unrelated individuals tested (77%), and for VNTR II in 29 out of 44 (66%) similar individuals. Family studies were carried out on 11 kindreds with von Willebrand disease (vWD). Ten of these families were found to be informative for one or other of the VNTRs or for a combination of data from both VNTRs. This method can be used for antenatal diagnosis and for carrier diagnosis in recessive forms of vWD. It is also useful for tracking the gene associated with vWD in type I families where there may be one or more individuals with a phenotypically uncertain diagnosis.

A computerized database for haemophilia patient records.

A microcomputer database system for the storage, retrieval, and statistical analysis of data associated with the treatment of haemophilia and other defects of haemostasis is described. The hardware requirements are an IBM compatible PC with both hard and floppy disc drives and a suitable printer. The system was written using Smartware II, a powerful integrated software package which incorporates database, word processor, spreadsheet and communications functions. The programs were written with flexibility in mind and can be readily adapted to accommodate the work patterns of any haemophilia centre. This system has now been operational in the Regional Haemophilia Centre at the Manchester Royal Infirmary since January 1990. Its introduction has led to a marked improvement in the efficiency of patient data handling with significant savings in staff time.

Continuous assessment of performance in External Quality Assessment Schemes.

A simple, standardised procedure was used for processing data from External Quality Assessment Schemes and for producing performance charts. A graphic presentation of cumulative performance is generated for each test, using an integrated software package to display results in a standardised format. This permits interpretation of satisfactory and poor performances and facilitates identification of "outlying" results. Although most results are recorded as Deviation Indices, the system is flexible and can be used to present other performance variables, such as Percentage Deviations and relevant textual information relating to interpretative assessments. It is therefore readily adaptable for use by other pathology disciplines.

Clinical and laboratory evaluation of National Health Service factor VIII concentrate (8Y) for the treatment of von Willebrand's disease.

This study was carried out to assess the efficacy of NHS 8Y concentrate in the treatment of patients with von Willebrand's disease (vWD). Eight patients (two type I vWD, one type IIA vWD, two type IIB vWD, and three type III vWD) were treated on a total of 10 occasions with 8Y. Following each treatment episode there was a temporary correction of patients' bleeding time (BT) measurements. Other laboratory parameters--von Willebrand factor ristocetin cofactor activity (vWf:RiCo), vWf antigen (vWf:Ag) levels, and factor VIII coagulant activity (factor VIII:C)--were also corrected. Plasma vWf multimers temporarily reflected those present in the infused concentrate. An effective clinical response was observed in each case despite, as revealed by autoradiography and scanning densitometry of SDS-agarose electrophoresis gels, a reduction in the concentration of the largest vWf multimers in 8Y compared with normal plasma. Overall, the clinical effectiveness of 8Y in vWD was comparable to that seen with cryoprecipitate. We conclude that NHS 8Y concentrate may be used as an alternative to cryoprecipitate for the treatment of vWD.

Life cycle strategies in two Antarctic Collembola.

1. Populations of two coexisting Antarctic Collembola were studied in the field and under constant conditions in the laboratory to determine their life cycles and to compare their energy utilisation. 2. In the field Parisotoma octooculata completes three to four moults during summer, overwintering either in the egg stage or in the fourth or fifth instars. Maturity is reached in the second year, with synchronous oviposition and hatching. Cryptopygus antarcticus has many overlapping generations, maturity is achieved in the third year and oviposition and hatching take place throughout the year. 3. In the laboratory P. octooculata has a faster rate of growth than C. antarcticus under constant conditions of temperature and humidity. Analysis of gut contents showed that the two species overlapped in their food range; the faster growth of P. octooculata being achieved by a faster consumption rate, since the two species had similar assimilation and production efficiencies. 4. The slower growth rate of C. antarcticus may not result from limited food availability, but from a better life cycle strategy for unpredictable environmental conditions. P. octooculata, which shows features more characteristic of temperate Collembola, may be a more recent Antarctic colonist.

Plasma exchange and human factor VIII concentrate in managing haemophilia A with factor VIII inhibitors.

Plasma exchanges were combined with human factor VIII concentrate therapy in the treatment of major bleeding episodes in five patients with haemophilia A and factor VIII inhibitors. All patients had a good clinical response to combined treatment. Inhibitor levels showed satisfactory falls before rapid secondary increases of inhibitor levels took place. A sixth patient with von Willebrand's disease and a factor VIII clotting activity inhibitor was successfully prepared for operation using plasma exchange. Postoperative haemostasis and healing were normal. In two patients the plasma exchanges were relatively more effective than the administered human factor VIII in reducing the levels of factor VIII inhibitor. Combined plasma exchange and human factor VIII treatment may offer a rapidly effective means of reducing factor VIII inhibitor levels in this group of patients, together with significant saving of costs.