Supporting older nurses and midwives in the Australian healthcare workplace-A qualitative descriptive study

AIM

To explore support strategies for older nurses and midwives in Australian healthcare workplaces.

DESIGN

A qualitative descriptive study.

METHOD

Participants were 50 older nurses and midwives and 20 healthcare managers recruited from a broad range of Australian healthcare settings. Data were collected using semi-structured interviews from November 2018 to April 2021. The interviews were recorded, transcribed and thematically analysed.

RESULTS

The limited number of identified sedentary roles and inequitable distribution of workload responsibilities were identified as constraints that impact the provision of workplace support for older nurses and midwives in healthcare settings. Three major themes were identified: Workplace support, Personal support and Doing more. A small number of participants reported support was available at work, but most said there was not. Of the reported strategies some were offered exclusively to a cohort that met an age criterion, while others were open to all staff regardless of age. Personal support strategies were employed outside of the workplace while others used strategies during working hours. Doing more related to suggestions about how organizations could do more to support older nurses and midwives at work.

CONCLUSION

Support mechanisms like adjustments in workload, employment fraction, practice location, upskilling and wellness programs in workplaces are limited. To facilitate retention and support older nurses and midwives in the workforce, health workplaces should consider implementing support mechanisms that can be tailored to the individual needs of the nurse or midwife over the life course of their career.

IMPACT

The findings of this study highlight the lack of support for many older nurses and midwives in Australian healthcare workplaces, emphasizing the need for further research into innovative practices on how to better support healthcare staff as they age.

REPORTING METHOD

This study adhered to the COREQ reporting method.

PATIENT OR PUBLIC CONTRIBUTION

No patient or public contribution.

Managers' perception of older nurses and midwives and their contribution to the workplace-A qualitative descriptive study

AIMS AND OBJECTIVES

The aim of this study was to explore healthcare managers' perceptions about older nurses' and midwives' and their contribution to the workplace.

DESIGN

A qualitative descriptive methodology.

METHOD

Twenty healthcare managers working in Australia participated in semi-structured interviews. Data were collected between April 2019 and April 2021. Interviews were recorded, transcribed and then analysed using thematic analysis.

RESULTS

All healthcare managers said older nurses and midwives contributed to the workplace through their experience and knowledge. Managers viewed them as a different type of worker and while there were some positive aspects to this, it was mostly negative. Although managers identified a broad age range for the older nurses or midwives, there was a common perception that if they were no longer able to perform their duties, they should leave the workforce.

CONCLUSION

Healthcare managers' perceptions towards older nurses and midwives are mostly negative, and their understanding of older workers' contribution is contradictory and poor. These negative views co-exist with the lack of agreement on who is the older worker, which explain the reluctance of healthcare organizations to invest in their older workforce. Future research is needed to better understand the unique contribution of older nurses and midwives in healthcare and how they can be supported at work.

IMPACT

The global ageing population will result in a rise in complex age-related health issues and will require an experienced and knowledgeable workforce. Given the greater experience of older nurses and midwives they are an important part of the health workforce. Yet managers' perception of the contribution by older nurses and midwives were often negative. The findings of this study highlight the need for organizational change so that the contribution of older nurses and midwives is recognized and supported by managers.

Being an older nurse or midwife in the healthcare workplace- A qualitative descriptive study

AIM

To explore the experiences of being an older nurse or midwife employed in the healthcare workplace.

DESIGN

A qualitative descriptive study.

METHOD

Semi-structured interviews were conducted with nurses and midwives who self-identified as older workers. All Australian states were represented and given recruitment was undertaken nationally, most interviews were conducted via telephone. Data were collected between November 2018 and October 2019. Audio recordings were transcribed verbatim and then thematically analysed.

RESULTS

A total of 50 nurses and midwives were recruited, aged between 46 and 74 years. Three themes were identified. Ageing body: Being an older worker meant increased fatigue and physical changes affecting their ability to function at full capacity. Youth focus: For many, being an older worker was about being viewed as a poor-quality worker, with limited access to education and promotional opportunities because of their age. Wise worker: For a small number of older nurses and midwives, it was about being valued and respected for their knowledge, experience and skills.

CONCLUSION

Participants self-identifying as older nurses or midwives represented a wide age range. Spanning across the age spectrum, many experienced fatigue, physical changes or loss of value to the workplace which often impacted on their working lives. The findings contributed to an understanding about what it is to be an older nurse or midwife in terms of how their contribution is regarded and valued by others in the workplace.

IMPACT

This study highlighted there is a need for support of older nurses and midwives in managing age-related fatigue and physical changes. It also suggests consideration of a wise-worker model as a means to recognize the important contribution that older workers can offer.

Osseous impingement occurs early in flexion in cam-type femoroacetabular impingement

Aims

The aim of this study was to examine the real time in vivo kinematics of the hip in patients with cam-type femoroacetabular impingement (FAI).

Patients and Methods

A total of 50 patients (83 hips) underwent 4D dynamic CT scanning of the hip, producing real time osseous models of the pelvis and femur being moved through flexion, adduction, and internal rotation. The location and size of the cam deformity and its relationship to the angle of flexion of the hip and pelvic tilt, and the position of impingement were recorded.

Results

In these patients with cam-type FAI, there was significant correlation between the alpha angle and flexion to the point of impingement (mean 41.36°; 14.32° to 57.95°) (R = -0.5815 and p = < 0.001). Patients with a large cam deformity (alpha angle > 78°) had significantly less flexion to the point of impingement (mean 36.30°; 14.32° to 55.18°) than patients with a small cam deformity (alpha angle 60° to 78°) (mean 45.34°; 27.25° to 57.95°) (p = < 0.001).

Conclusion

This study has shown that cam-type impingement can occur early in flexion (40°), particularly in patients with large anterior deformities. These patients risk chondrolabral damage during routine activities such as walking, and going up stairs. These findings offer important insights into the cause of the symptoms, the mechanisms of screening and the forms of treatment available for these patients. Cite this article: Bone Joint J 2017;99-B(4 Supple B):41–8.

Creating a Common Data Model for Comparative Effectiveness with the Observational Medical Outcomes Partnership

BACKGROUND

Adoption of a common data model across health systems is a key infrastructure requirement to allow large scale distributed comparative effectiveness analyses. There are a growing number of common data models (CDM), such as Mini-Sentinel, and the Observational Medical Outcomes Partnership (OMOP) CDMs.

OBJECTIVES

In this case study, we describe the challenges and opportunities of a study specific use of the OMOP CDM by two health systems and describe three comparative effectiveness use cases developed from the CDM.

METHODS

The project transformed two health system databases (using crosswalks provided) into the OMOP CDM. Cohorts were developed from the transformed CDMs for three comparative effectiveness use case examples. Administrative/billing, demographic, order history, medication, and laboratory were included in the CDM transformation and cohort development rules.

RESULTS

Record counts per person month are presented for the eligible cohorts, highlighting differences between the civilian and federal datasets, e.g. the federal data set had more outpatient visits per person month (6.44 vs. 2.05 per person month). The count of medications per person month reflected the fact that one system's medications were extracted from orders while the other system had pharmacy fills and medication administration records. The federal system also had a higher prevalence of the conditions in all three use cases. Both systems required manual coding of some types of data to convert to the CDM.

CONCLUSIONS

The data transformation to the CDM was time consuming and resources required were substantial, beyond requirements for collecting native source data. The need to manually code subsets of data limited the conversion. However, once the native data was converted to the CDM, both systems were then able to use the same queries to identify cohorts. Thus, the CDM minimized the effort to develop cohorts and analyze the results across the sites.

Modifying Threadline Dynamics in the High-speed Melt Spinning Process

Polyethylene terephthalate (PET) was spun into fibers in the speed range of 3000 to 5000 m/min. Threadline dynamics was modified by altering the threadline temperature profile. This was achieved using a combination of on-line zone cooling and heating(OLZCH). Experimental results showed that the structure development in the threadline was significantly influenced by the OLZCH conditions. The orientation, crystallinity and crystal dimensions of the resulting fibers were greatly increased by the introduction of OLZCH in the take-up speed range of 3000 to 5000 m/min. Various characterization techniques confirmed that the fiber structure was obviously changed with OLZCH. The fiber tensile properties were noticeably improved via this approach. It is concluded that the fiber structure development may be dominantly enhanced by modifying the threadline dynamics in the high speed melt spinning process.

Functional evaluation of TNFAIP3 (A20) in rheumatoid arthritis

OBJECTIVES

To determine the protein expression of TNFAIP3 in synovium and to show the capability of 6q23 intergenic SNPs, associated with rheumatoid arthritis (RA) susceptibility, to influence TNFAIP3 gene transcription.

METHODS

Immunohistochemistry for TNFAIP3, NF-kB p65 and phosphorylated NF-kB p65 protein expression was performed in 6 RA knee joint synovium samples compared to 9 osteoarthritis (OA) samples. Luciferase reporter gene assays were used to examine the regulatory ability of RA associated SNP variants on TNFAIP3 promoter activity. Sense and antisense constructs were prepared for rs6920220 alleles, together with each of the 4 SNPs in r2=1 with it (rs6933404, rs2327832, rs6927172 and rs17264332), coupled to the TNFAIP3 promoter. Transient transfections were performed in a human T lymphoblastoid (CEMC7A) cell line. Bioinformatic software was utilised to prioritise SNPs for further investigation. Electrophoretic mobility shift assays (EMSA), using CEMC7A nuclear extracts, were conducted for the rs6927172 SNP alleles.

RESULTS

TNFAIP3 protein expression was seen in the synovium samples and differential TNFAIP3 protein expression between RA vs. OA synoviocytes observed. Within RA synoviocytes TNFAIP3 expression is predominately cytoplasmic, whereas in OA its expression is strongly nuclear and cytoplasmic. For 3 of the 5 SNPs investigated (rs6920220, rs6933404, rs6927172) evidence of repressor activity of TNFAIP3 transcription was seen and EMSA data showed evidence of differential transcription factor binding to rs6927172 alleles.

CONCLUSIONS

This is the first observation of TNFAIP3 protein expression in RA and OA synovium. In vitro analysis of 6q23 intergenic SNPs supports the possibility of the functional regulation of TNFAIP3.

Studies on the Control of Cylindrocladium buxicola Using Fungicides and Host Resistance

Cylindrocladium buxicola is a fungal pathogen that causes a severe leaf and twig blight on Buxus spp. Laboratory experiments were carried out to study the in vitro effect of 13 fungicides on mycelial growth and conidia germination of the fungus. Based on the values of the effective concentration at which mycelial growth was inhibited by 50%, the fungicide Stroby (kresoxim-methyl) and the combined fungicides Opponent (epoxiconazole + kresoxim-methyl + pyraclostrobin), Opera (epoxiconazole + pyraclostrobin), and Signum (boscalid + pyraclostrobin) were the most effective at inhibiting mycelial growth and conidia germination. Pathogenicity assays showed that the host range of the fungus was not limited to the genus Buxus because Sarcococca sp. also was susceptible. None of the 10 boxwood species and cultivars tested were immune to the disease, although Buxus balearica as well as Sarcococca sp. showed significantly lower levels of infection as measured by the expression of leaf symptoms and the number of conidia produced on host tissue, the latter probably contributing to the apparent resistance of these species in the field. Microscopic observation showed that disease development was very rapid and aggressive on B. sempervirens 'Suffruticosa' where it was able to survive at least 5 years on decomposing fallen leaves.

Chromium, cobalt and titanium metallosis involving a Nottingham shoulder replacement

Metallosis after shoulder replacement has not previously been described in the literature. We report a patient who developed extensive metallosis after implantation of an uncemented Nottingham shoulder replacement. He underwent a revision procedure. Examination of the retrieved prosthesis showed that the titanium porous coating was separating from the humeral stem and becoming embedded in the ultra-high-molecular-weight polyethylene glenoid component, resulting in abrasive wear of the humeral component. There was metallosis despite exchange of the modular humeral head. Both components had to be exchanged to resolve the problem.

Acquisition of biologically relevant gene expression data by Affymetrix microarray analysis of archival formalin-fixed paraffin-embedded tumours

Robust protocols for microarray gene expression profiling of archival formalin-fixed paraffin-embedded tissue (FFPET) are needed to facilitate research when availability of fresh-frozen tissue is limited. Recent reports attest to the feasibility of this approach, but the clinical value of these data is poorly understood. We employed state-of-the-art RNA extraction and Affymetrix microarray technology to examine 34 archival FFPET primary extremity soft tissue sarcomas. Nineteen arrays met stringent QC criteria and were used to model prognostic signatures for metastatic recurrence. Arrays from two paired frozen and FFPET samples were compared: although FFPET sensitivity was low ( approximately 50%), high specificity (95%) and positive predictive value (92%) suggest that transcript detection is reliable. Good agreement between arrays and real time (RT)-PCR was confirmed, especially for abundant transcripts, and RT-PCR validated the regulation pattern for 19 of 24 candidate genes (overall R(2)=0.4662). RT-PCR and immunohistochemistry on independent cases validated prognostic significance for several genes including RECQL4, FRRS1, CFH and MET - whose combined expression carried greater prognostic value than tumour grade - and cmet and TRKB proteins. These molecules warrant further evaluation in larger series. Reliable clinically relevant data can be obtained from archival FFPET, but protocol amendments are needed to improve the sensitivity and broad application of this approach.

Morphological and glycosylation changes associated with the endometrium and ectopic lesions in a baboon model of endometriosis

BACKGROUND

Endometriosis is one of the most common causes of infertility and pelvic pain. A baboon model has recently been developed whereby the intrapelvic injection of menstrual endometrium results in the induction of endometriotic lesions. We have used this model to investigate changes in ultrastructure and glycosylation of endometria from normal and diseased baboons.

METHODS

Endometriosis was induced in eight female baboons; endometrial tissue and endometriotic lesions were removed on days 9-11 post ovulation between 3 and 16 months of disease and compared with endometrium from 17 control animals, using electron microscopy and lectin histochemistry.

RESULTS

Ultrastructurally, diseased endometrial glands showed abnormalities in secretory vacuoles and an intracellular accumulation of glycogen; in later stages of the disease, glands resembled those of the late secretory phase endometrium. The abnormalities were mirrored by changes in glycan expression. In early disease, there was an increased binding of lectin from Dolichos biflorus agglutinin (DBA) to fucosylated N-acetylglucosamine residues, whereas in later stages, this binding generally decreased in association with the appearance of a late secretory phenotype.

CONCLUSIONS

Endometriosis is accompanied by progressive changes in the gland architecture and biochemistry resulting in dyssynchrony within the window of uterine receptivity, which may result in the reduced fertility associated with this disease.

The effects of lanthanum carbonate and calcium carbonate on bone abnormalities in patients with end-stage renal disease

BACKGROUND

Renal osteodystrophy is a common complication of end-stage renal disease (ESRD) and is a major cause of morbidity in patients with ESRD. High serum levels of phosphorus, calcium and parathyroid hormone are associated with the development of this disease. The effects on bone of treatment with lanthanum carbonate, a new phosphate binder, and calcium carbonate were assessed in patients with ESRD.

METHODS

This was an open-label, multicenter, parallel-group study. Patients were recruited within 12 weeks of commencing dialysis. Following screening, phosphate binder administration was stopped, tetracycline labeling administered and a transiliac bone biopsy taken. After randomization to lanthanum carbonate or calcium carbonate, patients were titrated to an optimum dose for 8 weeks and maintained at this dose for 44 weeks. The bone was then labeled and a second biopsy taken. Biopsy samples were analyzed histomorphometrically.

RESULTS

Paired bone biopsies from 33 lanthanum carbonate- and 30 calcium carbonate-treated patients were suitable for analysis. None of the patients on either treatment developed osteomalacia. Assessment of activation frequency changes showed that 41% of biopsies from lanthanum carbonate-treated patients moved towards normal (observed values at the follow-up biopsy were closer to expected values than were the baseline values, so patients were considered to be improved) compared with 23% of calcium carbonate-treated patients (p = 0.15).

CONCLUSIONS

This study indicates that there was no evidence of aluminum-like toxicity with lanthanum carbonate after 1 year of treatment in ESRD patients commencing dialysis, and there appeared to be a beneficial effect on bone-cell function and activity compared with calcium carbonate.

Skeletal bone morphology is resistant to the high amplitude seasonal leptin cycle in the Siberian hamster

Recent studies have suggested that the adipocyte-derived hormone, leptin, plays a role in the regulation of metabolism. Here, we tested this hypothesis in the seasonally breeding Siberian hamster, as this species exhibits profound seasonal changes in adiposity and circulating leptin concentrations driven by the annual photoperiodic cycle. Male hamsters were kept in either long (LD) or short (SD) photoperiods. Following exposure to short photoperiods for 8 weeks animals exhibited a significant weight-loss and a 16-fold reduction of serum leptin concentrations. At Week 9, animals in both photoperiods were infused with leptin or PBS via osmotic mini-pump for 14 days. Chronic leptin infusion mimicked LD-like concentrations in SD-housed animals and caused a further decline in body weight and adipose tissue. In LD-housed animals, leptin infusion resulted in a significant elevation of serum concentrations above natural LD-like levels, but had no discernable effect on body weight or overall adiposity. Both bending and compression characteristics and histomorphometric measurements of trabecular bone mass were unaltered by leptin treatment or photoperiod. Our data therefore show that despite a high natural amplitude cycle of leptin, this hormone has no apparent role in the regulation of bone metabolism, and therefore do not support recent propositions that this hormone is an important component in the metabolism of bone tissue.

Diabetes in rat pregnancy alters renal calcium and magnesium reabsorption and bone formation in adult offspring

AIMS/HYPOTHESIS

We tested the hypothesis that diabetes in pregnancy can result in the in-utero reprogramming of renal calcium and magnesium handling and of bone formation in the offspring, which persists into adulthood.

METHODS

Male offspring of streptozotocin-treated diabetic rats (OD rats) and of control non-diabetic animals (OC rats) were investigated as neonates and at 8, 12 and 16 weeks of age.

RESULTS

Compared with OC rats, urinary calcium and magnesium output was significantly reduced in OD rats at every age studied; Na+ and K+ outputs were unaffected. The renal expression of proteins involved in the tubular reabsorption of calcium (calcium ATPase, calbindin-D28k and epithelial calcium channel) was increased in OD animals compared with that in OC animals. Additionally, we observed that adult OD rats had lower trabecular and higher cortical femoral bone volumes, explained by deposition of bone on the endosteal surface.

CONCLUSIONS/INTERPRETATION

These data show that diabetes in pregnancy has profound effects on male offspring in terms of renal tubular calcium and magnesium reabsorption and the normal pattern of bone formation. These effects persist into adulthood. Such long-lasting effects of diabetes on kidney and the skeleton were not suspected and could have important implications for the health of children born to diabetic women.

Adipocytic proportion of bone marrow is inversely related to bone formation in osteoporosis

AIMS

Preliminary studies have suggested that there is an increase in adipocytic tissue in osteoporotic (OP) bone, supporting in vitro evidence for a switch in differentiation of stromal cells from the osteoblastic to the adipocytic lineage. To investigate this the variation of the ratio of adipose tissue to haemopoietic/stromal tissue in OP bone was measured.

METHODS

The ratio of adipocytic to haemopoietic/stromal tissue (A/H) was measured by semi-automated image analysis in iliac crest biopsies from 127 patients with osteoporosis (84 female patients, 48 male patients; mean age, 55 years; range, 5-80). Fourteen patients with normal histomorphometric data (nine women; five men; mean age, 48 years; range 21-70) acted as controls.

RESULTS

The ratio of A/H was higher in OP bone than in the normal controls (OP mean 43.06% v normal mean 22.4%; p < 0.001). Multiple regression analysis showed that 98.5% of the variability in the A/H ratio was the result of age and several measures of bone formation, including cancellous wall thickness, osteoid volume, cancellous thickness, cortical wall thickness, cancellous apposition rate, and bone formation rate, together with cancellous separation (each significant at p < 0.001). Those with the greatest effect on the A/H ratio (in decreasing order) were cancellous apposition rate, osteoid volume, and age.

CONCLUSIONS

Cancellous apposition rate, osteoid volume, and age were associated with the increase in the proportion of adipose tissue present in OP bone. Of these, cancellous apposition rate reflects osteoblast activity, indicating that the increase in the volume of adipose tissue in osteoporosis is associated with reduced bone formation, supporting the postulated switch in differentiation of stromal cells from the osteoblastic to the adipocytic pathway in osteoporosis.

A novel cell culture model of chondrocyte differentiation during mammalian endochondral ossification

Endochondral ossification (EO) occurs in the growth plate where chondrocytes pass through discrete stages of proliferation, maturation, hypertrophy, and calcification. We have developed and characterized a novel bovine cell culture model of EO that mirrors these events and will facilitate in vitro studies on factors controlling chondrocyte differentiation. Chondrocytes derived from the epiphyses of long bones of fetal calves were treated with 5-azacytidine (aza-C) for 48 h. Cultures were maintained subsequently without aza-C and harvested at selected time points for analyses of growth and differentiation status. A chondrocytic phenotype associated with an extensive extracellular matrix rich in proteoglycans and collagen types II and VI was observed in aza-C-treated and -untreated cultures. aza-C-treated cultures were characterized by studying the expression of several markers of chondrocyte differentiation. Parathyroid hormone-related protein (PTHrP) and its receptor, both markers of maturation, were expressed at days 5-9. Type X collagen, which is restricted to the stage of hypertrophy, was expressed from day 11 onward. Hypertrophy was confirmed by a 14-fold increase in cell size by day 15 and an increased synthesis of alkaline phosphatase during the hypertrophic period (days 14-28). The addition of PTHrP to aza-C-treated cultures at day 14 led to the down-regulation of type X collagen by 6-fold, showing type X collagen expression is under the control of PTHrP as in vivo. These findings show that aza-C can induce fetal bovine epiphyseal chondrocytes to differentiate in culture in a manner consistent with that which occurs during the EO process in vivo.

Fluorescent location of malignant cells in fine needle aspirates

Malignant cells in fine needle aspirates possess a cell surface protease which can be targeted with fluorescent affinity probes. Cells with active GB exhibit cell surface fluorescence when stained with such affinity probes. The nuclei of all cells on the slides can be counterstained with a nuclear fluorescent stain. Malignant cells are then located by their cell surface fluorescence and their diagnosis confirmed by examining their fluorescent nuclei. Normal cells and benign cells exhibit no cell surface fluorescence and can be ignored. This technique can be used to rapidly select cells of cytological interest in FNA samples obtained routinely and might be adapted for automated screening of FNA.

The PDZ-interacting domain of cystic fibrosis transmembrane conductance regulator is required for functional expression in the apical plasma membrane

Polarization of cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-activated chloride channel to the apical plasma membrane in epithelial cells is critical for vectorial chloride transport. Previously, we reported that the C terminus of CFTR constitutes a PDZ-interacting domain that is required for CFTR polarization to the apical plasma membrane and interaction with the PDZ domain-containing protein EBP50 (NHERF). PDZ-interacting domains are typically composed of the C-terminal three to five amino acids, which in CFTR are QDTRL. Our goal was to identify the key amino acid(s) in the PDZ-interacting domain of CFTR with regard to its apical polarization, interaction with EBP50, and ability to mediate transepithelial chloride secretion. Point substitution of the C-terminal leucine (Leu at position 0) with alanine abrogated apical polarization of CFTR, interaction between CFTR and EBP50, efficient expression of CFTR in the apical membrane, and chloride secretion. Point substitution of the threonine (Thr at position -2) with alanine or valine had no effect on the apical polarization of CFTR, but reduced interaction between CFTR and EBP50, efficient expression of CFTR in the apical membrane as well as chloride secretion. By contrast, individual point substitution of the other C-terminal amino acids (Gln at position -4, Asp at position -3 and Arg at position -1) with alanine had no effect on measured parameters. We conclude that the PDZ-interacting domain, in particular the leucine (position 0) and threonine (position -2) residues, are required for the efficient, polarized expression of CFTR in the apical plasma membrane, interaction of CFTR with EBP50, and for the ability of CFTR to mediate chloride secretion. Mutations that delete the C terminus of CFTR may cause cystic fibrosis because CFTR is not polarized, complexed with EBP50, or efficiently expressed in the apical membrane of epithelial cells.

Placenta growth factor (PlGF) induces vascular endothelial growth factor (VEGF) secretion from mononuclear cells and is co-expressed with VEGF in synovial fluid

The aims of this study were (i) to determine whether PlGF, VEGF and PlGF/VEGF heterodimers are detected in synovial fluid (SF) and plasma samples from patients with a range of arthropathies; (ii) to describe whether any correlation exists between SF PlGF, VEGF and PlGF/VEGF heterodimer levels and the total and differential SF leucocyte counts; and (iii) to investigate the regulation of peripheral blood mononuclear cell (PBMC) VEGF secretion by stimuli relevant to inflammatory joints. PlGF, VEGF and PlGF/VEGF heterodimer levels were measured in the SF and plasma of patients with a range of arthropathies and normal controls by ELISA. Western blotting for PlGF was performed on SF from three patients with rheumatoid arthritis (RA) and primary inflammatory arthropathies. VEGF was quantified in cell culture supernatants after stimulation with lipopolysaccharide (LPS), PlGF or cobalt ions of PBMC isolated from RA patients and controls. PlGF and VEGF were detected in all SF samples. PlGF/VEGF heterodimers were detected in 10.2% of SF samples, most frequently in RA samples. Western blotting confirmed the presence of PlGF in RA SF. PlGF was detected in 52% of RA and 31% of control plasma samples, and VEGF was detected in 38% of RA and 38% of control plasma samples. PlGF/VEGF heterodimers were detected in 21% of RA samples and none of the control samples. In primary inflammatory arthropathy patients, SF PlGF and VEGF levels correlated significantly with the SF total leucocyte count and the neutrophil count. PlGF was the most potent inducer of PBMC VEGF production in both RA and control subjects. This is the first report of the detection of PlGF and PlGF/VEGF heterodimers in the SF of patients with inflammatory arthropathies, and we have shown for the first time that PlGF up-regulates PBMC VEGF production. PlGF may therefore play a key role in the production of VEGF in the inflammatory joint.

A simple, inexpensive method for teaching how membrane potentials are generated

We have developed a simple laboratory exercise that uses an inexpensive dialysis membrane (molecular weight cutoff = 100) to illustrate the generation of membrane potentials (Vm) across plasma membranes of animal cells. A piece of membrane approximately 2.0 cm2 is mounted in an Ussing-like chamber. One chamber half is designated cytosol and the other half external. Chamber sidedness helps students relate their findings to those of real cells. As in real cells, outward directed K+ concentration gradients [high cytosolic K+ concentration ([K+]c) and low extracellular K+ concentration] generate cytosol electrically negative Vm with a slope of approximately -45 mV/decade change in [K+]c. The polarity of Vm reflects the outward flow of potassium ions because flow of the larger counterion, H2PO4-, is restricted to the pores in the membrane. A slope less than Nernstian (<59 mV/decade) suggests that the membrane is slightly permeable to H2PO4-. Importantly, this facilitates teaching the use of the Nernst equation to quantify the relationship between ion concentration ratios across membranes and magnitude of Vm. For example, students use their data and calculate a permeability ratio PK/PH2PO4 that corresponds to a slope of approximately 24% less than Nernstian. This calculation shows that Nernstian slopes are achieved only when permeability to the counterion is zero. Finally, students use the concept of membrane capacitance to calculate the number of ions that cross the membrane. They learn where these ions are located and why the bulk solutions conform to the principle of electroneutrality.

A PDZ-interacting domain in CFTR is an apical membrane polarization signal

Polarization of the cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-activated chloride channel, to the apical plasma membrane of epithelial cells is critical for vectorial transport of chloride in a variety of epithelia, including the airway, pancreas, intestine, and kidney. However, the motifs that localize CFTR to the apical membrane are unknown. We report that the last 3 amino acids in the COOH-terminus of CFTR (T-R-L) comprise a PDZ-interacting domain that is required for the polarization of CFTR to the apical plasma membrane in human airway and kidney epithelial cells. In addition, the CFTR mutant, S1455X, which lacks the 26 COOH-terminal amino acids, including the PDZ-interacting domain, is mispolarized to the lateral membrane. We also demonstrate that CFTR binds to ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50), an apical membrane PDZ domain-containing protein. We propose that COOH-terminal deletions of CFTR, which represent about 10% of CFTR mutations, result in defective vectorial chloride transport, partly by altering the polarized distribution of CFTR in epithelial cells. Moreover, our data demonstrate that PDZ-interacting domains and PDZ domain-containing proteins play a key role in the apical polarization of ion channels in epithelial cells.

Evidence for the induction of a tumour associated cell surface protease on cytologically normal epithelial cells present in the sputum of patients possessing lung tumours

Sputum obtained from healthy subjects and patients with known lung tumours has been challenged with fluorescent probes for the presence of an active cell surface protease. The mature epithelial cells from healthy patients' sputum lacked ability to bind these fluorescent probes whilst the majority of mature epithelial cells in the tumour patients' sputum bound these probes and consequently fluoresced. This demonstrable difference in the cell surface chemistry of mature epithelial cells was linked to the presence of lung tumour cells, which also possessed this cell surface protease. The mechanism of this induced cell surface enzyme appearance is not understood.

Differential patterns of altered bone formation in different bone compartments in established osteoporosis

AIM

To investigate the level of bone formation in the different bone compartments in cases of established osteoporosis, as previous work has concentrated on trabecular bone alone.

METHODS

Bone formation rates were measured histomorphometrically, in the periosteal (P), cortical (C), subcortical (SC), and trabecular (T) compartments in iliac crest biopsies from 159 patients with established osteoporosis. The values were standardised using age and sex matched control data and patterns of differential change determined by analysis of parametric status (increased, normal, reduced).

RESULTS

Mean bone formation was reduced in all four compartments. This was more marked (4.4/4.1 standard deviations below the mean in C/T, v 2.3/0.9 in P/SC) and more frequent (reduced in 81.5%/78.3% in T/C, v 43.3%/44% in P/SC) in the trabecular and cortical compartments than in the periosteal or subcortical bone. Parametric status was equal in trabecular and cortical bone in 85.4% of cases, and in periosteal and subcortical bone in 65.7%, but in all four compartments in only 35.1%, indicating differential alteration of bone formation in the two sets of compartments (T/C v P/SC).

CONCLUSIONS

Altered trabecular bone formation is important in osteoporosis, but there are differential patterns of alteration in the other three compartments, emphasising the presence of different microenvironments in bone; thus the effect on the cortical compartment was similar to that on the trabecular, while the subcortical and periosteal compartments also showed linkage. The linkage between the two pairs was divergent, indicating different control of bone formation, with resultant different patterns of perturbation in osteoporosis.

Luminal L-alanine stimulates exocytosis at the K+-conductive apical membrane of Aplysia enterocytes

In Aplysia intestine, stimulation of Na+ absorption with luminal alanine increases apical membrane K+ conductance (GK,a), which presumably regulates enterocyte volume during stimulated Na+ absorption. However, the mechanism responsible for the sustained increase in plasma membrane K+ conductance is not known for any nutrient-absorbing epithelium. In the present study, we have begun to test the hypothesis that the alanine-induced increase in GK,a in Aplysia enterocytes results from exocytic insertion of K+ channels into the apical membrane. We used the fluid-phase marker horseradish peroxidase to assess the effect of alanine on apical membrane exocytosis and conventional microelectrode techniques to assess the effect of alanine on fractional capacitance of the apical membrane (fCa). Luminal alanine significantly increased apical membrane exocytosis from 1.04 +/- 0.30 to 1.39 +/- 0.38 ng. min-1. cm-2. To measure fCa, we modeled the Aplysia enterocyte as a double resistance-capacitance (RC) electric circuit arranged in series. Several criteria were tested to confirm application of the model to the enterocytes, and all satisfied the model. When added to the luminal surface, alanine significantly increased fCa from 0.27 +/- 0. 02 to 0.33 +/- 0.04 (n = 10) after 4 min. There are two possible explanations for our findings: 1) the increase in exocytosis, which adds membrane to the apical plasma membrane, prevents plasma membrane fracture, and 2) the increase in exocytosis delivers K+ channels to the apical membrane by exocytic insertion. After the alanine-induced depolarization of apical membrane potential (Va), there is a strong correlation (r = 0.96) between repolarization of Va, which reflects the increase in GK,a, and increase in fCa. This correlation supports the exocytic insertion hypothesis for activation of GK,a.

The bcl-2 knockout mouse exhibits marked changes in osteoblast phenotype and collagen deposition in bone as well as a mild growth plate phenotype

Histological examination of long bones from 1-day-old bcl-2 knockout and age-matched control mice revealed no obvious differences in length of bone, growth plate architecture or stage of endochondral ossification. In 35-day-old bcl-2 knockout mice that are growth retarded or 'dwarfed'. the proliferative zone of the growth plate appeared slightly thinner and the secondary centres of ossification less well developed than their age-matched wild-type controls. The most marked histological effects of bcl-2 ablation were on osteoblasts and bone. 35-day-old knockout mouse bones exhibited far greater numbers of osteoblasts than controls and the osteoblasts had a cuboidal phenotype in comparison with the normal flattened cell appearance. In addition, the collagen deposited by the osteoblasts in the bcl-2 knockout mouse bone was disorganized in comparison with control tissue and had a pseudo-woven appearance. The results suggest an important role for Bcl-2 in controlling osteoblast phenotype and bone deposition in vivo.

Blood vessel density in canine osteosarcoma

Canine osteosarcoma is a prevalent bone neoplasm which has similarities to the human disease. We used a retrospective study to investigate the possibility that tumor vascularity may provide useful prognostic information, indicative of the role of this parameter in progression of this cancer. We quantified microvessel density in 52 histological specimens of primary tumor, immunostained for von Willebrand's Factor to identify vascular endothelium. For the 20 cases not euthanized at presentation or lost to follow-up, we found significantly higher tumor microvascular densities in animals presenting with detectable pulmonary metastases (5 of 20), and significantly lower densities in animals without metastatic disease at presentation, but later surviving to develop pulmonary metastases (7 of 20; P < 0.05). Animals with no evidence of pulmonary metastases at time of death (8 of 20) had intermediate vascular densities in their tumors. The results of this preliminary study suggest that vascularity of the primary tumor may be an indication of tumor progression. Future studies with a larger number of cases should establish whether vascular density can be a useful prognostic parameter for canine osteosarcoma.

Isolated plantar fracture-dislocation of the middle cuneiform

A previously unreported case of plantar dislocation of the medial cuneiform is described. The significance of this injury does not lie in its rarity, but in the amount of force required to cause such an injury. This large force may cause bony disruption, along with significant soft-tissue injury, and even compartment syndrome. Analysis of the preoperative evaluation, including the importance of a computed axial tomographicscan, operative intervention, and postoperative care are discussed.

The nurse's role in treating fertility problems

This article is the fifth part of our series on aspects of fertility. The role of nursing in this specialty is described alongside the training and education needed to develop this role.

Educating nurses--the assisted conception nursing care course of the RCN Institute

The Assisted Conception Nursing Care course of the Royal College of Nursing Institute is approaching its 5 yearly review. This professionally and academically validated course was designed in collaboration with the Fertility Nurses Group to meet the needs of those in specialist practice who are taking an increasingly significant role in the care of those needing support and treatment for fertility problems. The 6 month part-time course addresses areas as diverse as physiology and pharmacology, behavioural sciences and ethical, legal and cultural issues. There is also an emphasis on research awareness and the analysis of nursing and social policy. The course draws nurses from a wide area within the UK who particularly value the opportunity to share ideas and construct ongoing networks.

Differential patterns of osteoblast dysfunction in trabecular bone in patients with established osteoporosis

AIMS

To analyse osteoblast function in 153 cases of established osteoporosis as previous work has indicated that osteoporosis is a heterogeneous condition characterised by different patterns of osteoclast and osteoblast dysfunction.

METHODS

Histomorphometric data from 153 cases with established osteoporosis was used to analyse osteoblast function, using the following parameters: osteoblast number was assessed using the ratio of osteoblast surface to bone surface (ObS:BS); the percentage of active osteoblasts was assessed by using mineralising surface as a proportion of osteoid surface (sLS + dLS/OS); and the efficiency of active osteoblasts was assessed using the ratio of double to total labelled surface (dLS:tLS). The values of each parameter were standardised using age and sex matched control data and a three dimensional matrix was used to identify groups of patients with similar patterns of altered function.

RESULTS

The largest group (60 cases) showed a reduction in all three parameters, while a small group (9 cases) had normal osteoblast function. However, one group showed reduction in osteoblast number only (23 cases), while another group showed a normal number of osteoblasts but both reduced percentage and efficiency of activity (14 cases). The results also suggest that efficiency of activity falls first and that this eventually leads to exit from the active pool.

CONCLUSIONS

These results demonstrate the presence of heterogeneity of osteoblast dysfunction in osteoporosis, indicating that the disease is caused by interference at a variety of target sites along the pathway of osteoblast proliferation, differentiation, and activation. Greater understanding of this pathway and of the variety of alterations in the pathway that can occur in osteoporosis may allow more focused therapy for different patient groups identified on the basis of histomorphometric analysis.

Overuse foot and ankle injuries in ballet

Incorrect techniques repeated daily by a dancer can lead to overuse injuries. This article discusses the causes and treatment of foot and ankle injuries in the ballet dancer. The author also addresses skin lesions that are common in dancers who wear pointe shoes.

Quantification of vitamin D receptor mRNA in tissue sections demonstrates the relative limitations of in situ-reverse transcriptase-polymerase chain reaction

In situ-reverse transcriptase-polymerase chain reaction (IS-RT-PCR) is a recently described technique that is used to localize low levels of mRNA within cells and tissue sections. One of the major criticisms levelled at this technique is that positive results may be meaningless, as amplification is required to demonstrate the transcripts of interest. The use of IS-RT-PCR to demonstrate mRNA for receptors for 1,25-dihydroxyvitamin D3 (VDR) in sections of human kidney and bone has previously been described. To ascertain whether the levels of VDR mRNA detected following IS-RT-PCR were transcriptionally significant, computerized image analysis was used to determine the mean silver grain density in human kidney and bone cells following conventional in situ hybridization and after various cycles of IS-RT-PCR. Only a few cycles of PCR were needed to produce an optimum signal, but amplification of signal following IS-RT-PCR was found to be relatively inefficient. Following the optimum number of cycles of IS-RT-PCR in kidney sections, there was a less than four-fold increase in signal. Similarly, in bone, the optimum signal detected was only approximately five times greater than that found with conventional in situ hybridization. These results clearly demonstrate that the increase in signal following IS-RT-PCR follows a more linear pattern and is relatively inefficient, compared with the usual exponential increase with conventional solution phase RT-PCR.

On the stability of a tumour cell surface protease after exposure to 6N HCl

Well defined acinar tumour cells in frozen sections were exposed to 6NHCl for 5 h at room temperature. A technique was designed to monitor the activity of the enzyme, guanidinobenzoatase (GB), on these tumour cells; this involved cross-linking the enzyme to the cell surface and challenging the active centre with known fluorescent probes which only bind to the functional enzyme. It was demonstrated that the enzymic activity can be regained by appropriate folding of the protein.

Mycobacterium xenopi--an unusual presentation as tenosynovitis of the wrist in an immunocompetent patient

Mycobacterium xenopi is an atypical acid-fast bacillus which may colonize tap water supplies. It typically causes pulmonary infection, particularly in patients with pre-existing lung damage, and non-pulmonary involvement is rare. We describe the first reported case of tenosynovitis due to this organism in an immunocompetent male patient.

Histomorphometric classification of postmenopausal osteoporosis: implications for the management of osteoporosis

AIMS

To define and group static and dynamic iliac crest histomorphometric parameters in women with established osteoporosis.

METHODS

Iliac crest biopsy specimens from 146 white women were sectioned undecalcified and examined using image analysis.

RESULTS

Five distinct groups were defined on the basis of histomorphometric changes in cell function: group 1, decreased osteoblastic and osteoclastic activity; group 2, decreased osteoblastic and increased osteoclastic activity; group 3, increased osteoblastic and osteoclastic activity; group 4, no bone surface cell activity; and group 5, apparently normal osteoblastic and osteoclastic activity.

CONCLUSIONS

Five distinct subgroups of patients with postmenopausal osteoporosis can be defined based on changes in bone cell function. Defining cellular dysfunction in this way may be important for tailoring treatment regimens to the needs of individual patients.