European gay fathers via surrogacy: Parenting, social support, anti-gay microaggressions, and child behavior problems

The present study investigated child behavior problems, parenting styles, coparenting, and couple relationship satisfaction in 67 European gay father families via surrogacy and 67 European heterosexual parent families via unassisted conception, all with children aged 1.5-10 years (M = 3.57 years, SD = 2.09). The two family groups were matched for child age and gender. In the gay father group only, the associations between family anti-gay microaggressions, family/friend support, and other main variables also were explored. Children of gay fathers had fewer externalizing and internalizing problems compared to children of heterosexual parents. Also, gay fathers reported more effective parenting styles, greater coparenting quality, and higher couple relationship satisfaction compared to heterosexual parents. Overall, child externalizing problems (i.e., aggression, rule-breaking) and internalizing problems (i.e., anxiety, depression) were more strongly associated with being raised in a heterosexual parent family, more authoritarian parenting, and lower positive coparenting. Specific to the gay father sample, anti-gay microaggressions experienced by family members were associated with more child internalizing problems, lower positive coparenting, and lower social support from family and friends. These results refute concerns about possible detrimental effects on child development of surrogacy conception or of being raised by gay fathers. The results further suggest that family therapists treating child behavior problems should focus mainly on improving the coparenting relationship, reducing authoritarian/punitive parenting styles, and (for gay father families specifically) coping with anti-gay microaggressions and lack of social support outside the nuclear family.

Investigating lipid headgroup composition within epithelial membranes: a systematic review

Membrane lipid composition is often quoted within the literature, but with very little insight into how or why these compositions vary when compared to other biological membranes. One prominent area that lacks understanding in terms of rationale for lipid variability is the human gastro-intestinal tract (GIT). We have carried out a comprehensive systematic literature search to ascertain the key lipid components of epithelial membranes, with a particular focus on addressing the human GIT and to use compositional data to understand structural aspects of biological membranes. Both bacterial outer membranes and the human erythrocyte membrane were used as a comparison for the mammalian [epithelial] membranes and to understand variations in lipid presence. We show that phosphatidylcholine (PC) lipid types tend to dominate (33%) with phosphatidylethanolamines (PE) and cholesterol having very similar abundances (25 and 23% respectively). This systematic review presents a detailed insight into lipid headgroup composition and roles in various membrane types, with a summary of the distinction between the major lipid bilayer forming lipids and how peripheral lipids regulate charge and fluidity. The variety of lipids present in biological membranes is discussed and rationalised in terms function as well as cellular position.

Diagnosis and management of community-acquired pneumonia in children: South African Thoracic Society guidelines

BACKGROUND

Pneumonia remains a major cause of morbidity and mortality amongst South African children. More comprehensive immunisation regimens, strengthening of HIV programmes, improvement in socioeconomic conditions and new preventive strategies have impacted on the epidemiology of pneumonia. Furthermore, sensitive diagnostic tests and better sampling methods in young children improve aetiological diagnosis.

OBJECTIVES

To produce revised guidelines for pneumonia in South African children under 5 years of age.

METHODS

The Paediatric Assembly of the South African Thoracic Society and the National Institute for Communicable Diseases established seven expert subgroups to revise existing South African guidelines focusing on: (i) epidemiology; (ii) aetiology; (iii) diagnosis; (iv) antibiotic management and supportive therapy; (v) management in intensive care; (vi) prevention; and (vii) considerations in HIV-infected or HIVexposed, uninfected (HEU) children. Each subgroup reviewed the published evidence in their area; in the absence of evidence, expert opinion was accepted. Evidence was graded using the British Thoracic Society (BTS) grading system. Sections were synthesized into an overall guideline which underwent peer review and revision.

RECOMMENDATIONS

Recommendations include a diagnostic approach, investigations, management and preventive strategies. Specific recommendations for HIV infected and HEU children are provided.

VALIDATION

The guideline is based on available published evidence supplemented by the consensus opinion of SA paediatric experts. Recommendations are consistent with those in published international guidelines.

Chronic rhinitis in South Africa - more than just allergy!

Chronic rhinitis is a troublesome condition for sufferers. It is tempting to label all patients with chronic nasal symptoms as having allergic rhinitis (AR), but many such patients have other causes of chronic rhinitis that need a specific diagnosis and management strategy. Even when the patient fully fits the definition of AR, their condition will be best served by combining medication with ongoing patient education.

Attitudes towards same-sex parenting in Italy: the influence of traditional gender ideology

This study aimed to examine the role of gender ideology, religiosity and political conservatism on attitudes toward same-sex parenting in Italy at a time when same-sex parent families are undergoing attacks from ideological campaigns opposing non-traditional gender roles and families. We collected data from 4,187 heterosexual respondents about attitudes towards two-father and two-mother parenting, homonegativity, attitudes toward traditional masculinity and femininity, religious involvement and political conservatism. We conducted multiple group structural equation model analyses to test whether sex moderated any of the estimated associations among variables. Results showed that traditional beliefs about femininity were directly associated with negative attitudes towards two-mother and two-father parenting, while traditional beliefs about masculinity had a significant direct effect only on two-father parenting. Homonegativity partially mediated the association between religiosity, political conservatism and traditional beliefs about masculinity and femininity on negative attitudes toward both types of same-sex parenting. Gender differences were found for the indirect effects of political conservatism and religiosity on attitudes towards same-sex parenting. The theoretical contributions and implications of the findings are discussed.

Performance Comparison of Two Anaesthetic Facemasks

When considering anaesthetic masks, the quality of the mask-face seal is a key determinant of performance. This randomised crossover trial utilises expired oxygen concentration to compare the efficacy of two routinely used facemasks. Thirty subjects were randomised to breathe 100% oxygen via either a traditional reusable black rubber mask or the disposable Intersurgical Scented mask for three minutes. This was then repeated using the other mask. To compare the impact of mask design on the quality of the mask-face seal, it was necessary to minimise measures taken by the anaesthetist to correct for a poor seal. To achieve this, the anaesthetist was requested to hold the mask in a manner consistent with an airtight seal, but they were blinded to capnography and reservoir bag movement. Expired oxygen concentration was recorded at 15-second intervals. From the oxygen wash-in curves, the Intersurgical mask consistently outperformed the black rubber mask. At three minutes the Intersurgical mask performed better than the black rubber mask, with mean end-tidal oxygen concentrations of 86.9% vs. 81% respectively; P=0.008. These findings indicate that the soft cuff design of the intersurgical mask provided a better seal than the black rubber facemask.

Dynamical Effects in Resonant X-Ray Diffraction

Using resonant magnetic diffraction at the Ni L_{2,3} edge in a LaNiO_{3} superlattice, we show that dynamical effects beyond the standard kinematic approximation can drastically modify the resonant scattering cross section. In particular, the combination of extinction and refraction convert maxima to minima in the azimuthal-angle dependence of the diffracted intensity, which is commonly used to determine orbital and magnetic structures by resonant x-ray diffraction. We provide a comprehensive theoretical description of these effects by numerically solving Maxwell's equations in three dimensions. The understanding and description of dynamical diffraction enhances the capabilities of resonant x-ray scattering as a probe of electronic ordering phenomena in solids.

Marital status, social support, and depressive symptoms among lesbian and heterosexual women

The current study investigated social support and relationship status (single, dating-but-not-cohabiting, cohabiting, domestic partnership/civil union, married) as predictors of depressive symptoms among lesbian and heterosexual women. The study aimed to determine whether the documented higher rates of depressive symptoms among lesbians compared to heterosexual women could be accounted for by lesbians' reduced access to, or in many cases exclusion from, legalized relationship statuses. The effect of social support from family and social support from friends on depressive symptoms also was examined. Contrary to expectations, results indicated no difference in levels of depressive symptoms among lesbian compared to heterosexual women in this sample. However, regardless of sexual orientation, married women had lower levels of depressive symptoms than unmarried women. Thus, marriage seems to be associated with less depression in lesbian and heterosexual women alike. The interaction of social support and relationship status added to the prediction of depressive symptoms over and above the predictive power of either variable alone, although this effect was small and should be interpreted with caution.

Adjacent Fe-Vacancy Interactions as the Origin of Room Temperature Ferromagnetism in (In(1-x)Fe(x))2O3

Dilute magnetic semiconductors (DMSs) show great promise for applications in spin-based electronics, but in most cases continue to elude explanations of their magnetic behavior. Here, we combine quantitative x-ray spectroscopy and Anderson impurity model calculations to study ferromagnetic Fe-substituted In2O3 films, and we identify a subset of Fe atoms adjacent to oxygen vacancies in the crystal lattice which are responsible for the observed room temperature ferromagnetism. Using resonant inelastic x-ray scattering, we map out the near gap electronic structure and provide further support for this conclusion. Serving as a concrete verification of recent theoretical results and indirect experimental evidence, these results solidify the role of impurity-vacancy coupling in oxide-based DMSs.

Extreme mobility enhancement of two-dimensional electron gases at oxide interfaces by charge-transfer-induced modulation doping

Two-dimensional electron gases (2DEGs) formed at the interface of insulating complex oxides promise the development of all-oxide electronic devices. These 2DEGs involve many-body interactions that give rise to a variety of physical phenomena such as superconductivity, magnetism, tunable metal-insulator transitions and phase separation. Increasing the mobility of the 2DEG, however, remains a major challenge. Here, we show that the electron mobility is enhanced by more than two orders of magnitude by inserting a single-unit-cell insulating layer of polar La(1-x)Sr(x)MnO3 (x = 0, 1/8, and 1/3) at the interface between disordered LaAlO3 and crystalline SrTiO3 produced at room temperature. Resonant X-ray spectroscopy and transmission electron microscopy show that the manganite layer undergoes unambiguous electronic reconstruction, leading to modulation doping of such atomically engineered complex oxide heterointerfaces. At low temperatures, the modulation-doped 2DEG exhibits Shubnikov-de Haas oscillations and fingerprints of the quantum Hall effect, demonstrating unprecedented high mobility and low electron density.

Expression of soluble triggering receptor expressed on myeloid cells-1 in childhood CF and non-CF bronchiectasis

BACKGROUND

Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) is demonstrating promise as an inflammatory biomarker of acute infection in various pulmonary conditions; including community acquired pneumonia, ventilator associated pneumonia and non-tuberculous mycobacterial infection.

INTRODUCTION

The expression of sTREM-1 has been poorly studied in all forms of bronchiectasis, both in the context of cystic fibrosis (CF) and non-cystic fibrosis bronchiectasis.

METHOD

Induced sputum samples were collected for sTREM-1 determination in children with HIV-associated bronchiectasis and CF-bronchiectasis. The presence or absence of an exacerbation was noted at study entry. Lung function parameters (FEV1, FVC, FEV1 /FVC, FEF(25-75)) were measured using the Viasys SpiroPro Jaeger Spirometer (Hoechberg, Germany).

RESULT

A total of twenty-six children with HIV-associated bronchiectasis and seventeen with CF were included. With respect to sTREM-1, the levels were readily detected in both groups, but were significantly higher in children with HIV-associated bronchiectasis (1244.0 pg/ml (iqr 194.5; 3755.3 pg/ml) and 204.9  pg/ml (iqr 66.9; 653.6 pg/ml) P = 0.003. There was a positive correlation between sTREM-1 and IL-8 as well as sputum neutrophil elastase in the HIV-bronchiectasis group (r = 0.715 and r = 0.630), respectively both P < 0.005. sTREM-1 was not further increased in subjects presenting with an acute pulmonary exacerbation in the HIV-associated bronchiectasis and in CF participants (P = 0.971 and P = 0.481), respectively. In the CF group sTREM-1 strongly correlated with FVC% predicted and FEV1 % predicted (r = 0.950 and r = 0.954), both P < 0.005.

CONCLUSION

The pulmonary innate immune functions are over-active in HIV-associated bronchiectasis, with readily detected sTREM-1 values, which were higher than those in CF. sTREM-1 does not correlate with markers of HIV-disease activity but does correlate with markers of neutrophilic inflammation. In CF sTREM-1 has a negative correlation with pulmonary function parameters.

Electronic structure and spin trapping in LiMnAs and LiFeAs:Mn

The electronic structure of insulating antiferromagnetic LiMnAs is investigated using soft x-ray spectroscopy and compared to the electronic structure of metallic LiFeAs. Our calculations support the experimentally observed insulating antiferromagnetic order in LiMnAs. The x-ray absorption and resonant inelastic x-ray scattering spectra in LiFeAs and LiMnAs are adequately explained by the electronic structure alone, although it is possible that LiMnAs has significant electronic correlations driven by Hund's J coupling. Finally, we show evidence of a possible spin trap in Li(Fe0.95Mn0.05)As.

Measuring partial fluorescence yield using filtered detectors

Typically, X-ray absorption near-edge structure measurements aim to probe the linear attenuation coefficient. These measurements are often carried out using partial fluorescence yield techniques that rely on detectors having photon energy discrimination improving the sensitivity and the signal-to-background ratio of the measured spectra. However, measuring the partial fluorescence yield in the soft X-ray regime with reasonable efficiency requires solid-state detectors, which have limitations due to the inherent dead-time while measuring. Alternatively, many of the available detectors that are not energy dispersive do not suffer from photon count rate limitations. A filter placed in front of one of these detectors will make the energy-dependent efficiency non-linear, thereby changing the responsivity of the detector. It is shown that using an array of filtered X-ray detectors is a viable method for measuring soft X-ray partial fluorescence yield spectra without dead-time. The feasibility of this technique is further demonstrated using α-Fe2O3 as an example and it is shown that this detector technology could vastly improve the photon collection efficiency at synchrotrons and that these detectors will allow experiments to be completed with a much lower photon flux reducing X-ray-induced damage.

Effect of 3d doping on the electronic structure of BaFe2As2

The electronic structure of BaFe(2)As(2) doped with Co, Ni and Cu has been studied by a variety of experimental and theoretical methods, but a clear picture of the dopant 3d states has not yet emerged. Herein we provide experimental evidence of the distribution of Co, Ni and Cu 3d states in the valence band. We conclude that the Co and Ni 3d states provide additional free carriers to the Fermi level, while the Cu 3d states are found at the bottom of the valence band in a localized 3d(10) shell. These findings help shed light on why superconductivity can occur in BaFe(2)As(2) doped with Co and Ni but not Cu.

Structural ordering in a silica glass matrix under Mn ion implantation

Mn(+)-implanted, amorphous SiO(2) samples were synthesized using pulsed-ion implantation without thermal annealing. The crystal and electronic structures have been studied using x-ray diffraction and synchrotron-based soft x-ray absorption and emission spectroscopy at the Si and Mn L(2,3) edges. We find a combination of small MnO clusters and Si crystallites at shallow depths while tetrahedral Mn coordination is found deeper in the host target. Through a combination of techniques, we find that the implantation process simultaneously decreases the long-range order in the near-surface region and increases order deeper in the SiO(2) host. Our results suggest Mn substitution into Si sites at deep levels catalyzes the formation of α-quartz, providing insight into the complex interactions that determine the local structure around the impurities as well as the overall changes to the crystallinity of implanted SiO(2).

Costs of admission for paediatric pneumonia in a setting of human immunodeficiency virus infection

BACKGROUND

Pneumonia in South African children remains a major public health concern. The costs of hospital admission for pneumonia should be determined, especially where human immunodeficiency virus (HIV) infection is common.

OBJECTIVE

To determine the hospital costs of children (HIV-infected vs. non-HIV-infected) admitted for the management of pneumonia and compare them in the public and fee-for-service sectors.

METHODS

A retrospective review of paediatric admissions in 2007 was performed. Costs were determined for the public and fee-for-service sectors. Outcome measures included hospital mortality and comparative costs of admission.

RESULTS

There were 132 admissions in a public sector facility (67% HIV-infected), and 7882 in the fee-for-service sector (1.2% HIV-infected). Total mortality was respectively 25% in the public and 0.04% in the fee-for-service sectors. The mean cost for HIV-infected patients was respectively US$639.06 and US$10 540.04 in the public and fee-for-service sectors. For non-HIV-infected patients, the cost was respectively US$399.45 and US$3936.87. Length of stay for HIV-infected patients was longer by respectively 1.8 days and 5.7 days in the public sector among admissions to the ward and to the paediatric intensive care unit.

CONCLUSION

Admission for HIV-infected children with pneumonia costs significantly more in both sectors. Preventive strategies are needed.

HIV-related bronchiectasis in children: an emerging spectre in high tuberculosis burden areas

BACKGROUND

Human immunodeficiency virus (HIV) infected children have an eleven-fold risk of acute lower respiratory tract infection. This places HIV-infected children at risk of airway destruction and bronchiectasis.

OBJECTIVE

To study predisposing factors for the development of bronchiectasis in a developing world setting.

METHODS

Children with HIV-related bronchiectasis aged 6-14 years were enrolled. Data were collected on demographics, induced sputum for tuberculosis, respiratory viruses (respiratory syncytial virus), influenza A and B, parainfluenza 1-3, adenovirus and cytomegalovirus), bacteriology and cytokines. Spirometry was performed. Blood samples were obtained for HIV staging, immunoglobulins, immunoCAP®-specific immunoglobulin E (IgE) for common foods and aeroallergens and cytokines.

RESULTS

In all, 35 patients were enrolled in the study. Of 161 sputum samples, the predominant organisms cultured were Haemophilus influenzae and parainfluenzae (49%). The median forced expiratory volume in 1 second of all patients was 53%. Interleukin-8 was the predominant cytokine in sputum and serum. The median IgE level was 770 kU/l; however, this did not seem to be related to atopy; 36% were exposed to environmental tobacco smoke, with no correlation between exposure and CD4 count.

CONCLUSION

Children with HIV-related bronchiectasis are diagnosed after the age of 6 years and suffer significant morbidity. Immune stimulation mechanisms in these children are intact despite the level of immunosuppression.

Heterosexual, lesbian, and gay male relationships: a comparison of couples in 1975 and 2000

This study examined the differences among lesbians, gay men, and heterosexuals at two points in time (1975 and 2000) using responses of 6,864 participants from two archival data sets. Groups were compared on variables representing equality of behaviors between partners in seven realms: traditionally "feminine" housework, traditionally "masculine" housework, finances, support, communication, requesting/refusing sex, and decision-making. In addition, the current study compared monogamy agreements and monogamy behaviors reported by the two cohorts of couple types. Overall, the results indicate that on the equality variables, there have been many statistically significant behavioral shifts among the different sexual orientations across 25 years. In addition, all couple types reported substantially greater rates of monogamy in the year 2000 than in 1975. The present study has important clinical implications for therapists working with couples because it provides new baseline evidence regarding how couples now interact with one another (especially about monogamy) and how this has shifted over time. In addition, it elucidates the differences that still exist between different couple types, which could serve to inform couple therapists as they strive to become more culturally competent working with same-sex couples.

Guideline for the management of chronic asthma in children--2009 update

OBJECTIVE

To revise the guideline for the diagnosis and management of chronic asthma in children in view of the following considerations: the existing South African Childhood Asthma Working Group (SACAWG) guideline was produced 10 years ago; diagnosis of asthma in young children remains a challenge; evidence-based treatment is the new paradigm; new treatment approaches to achieving and maintaining control; therapeutic roles of several medications have evolved; more studies and data on treatment in young children; new medications and formulations; a change of emphasis in assessing asthma control to guide treatment changes. The main aim of the guideline is to promote a better standard of treatment based on understanding of the pathophysiology and pharmacotherapy of asthma, and encouraging uniformity in asthma management.

EVIDENCE

A detailed literature review by a working group of clinicians from relevant disciplines. The strategies recommended are classified according to the evidence category in Appendix B, and denoted as Evidence A, B, C and D.

RECOMMENDATIONS

These include an appropriate diagnostic approach, environmental control measures, treatment options, definition of asthma control, and strategies to achieve control.

ENDORSEMENT

The guideline document was endorsed by the South African Thoracic Society (SATS), the National Asthma Education Programme (NAEP), the South African Paediatric Association (SAPA) and the South African Academy of Family Practice.

Comparison of doctor and patient assessments of asthma control

INTRODUCTION

The objective of asthma management is to control the condition. However, world-wide surveys reveal that only 5% of asthmatics are well controlled. One reason for this phenomenon is the fact that patients and doctors consistently over-estimate control. This study compared patient and doctor assessment of asthma control.

METHODS

A random sample of asthmatics was identified by practitioners in South Africa. Patients completed an Asthma Control Test (ACT) and provided a list of medications currently being taken. The doctor also provided an assessment of control which was summarised into the categories - 'not controlled' and 'controlled' and listed all medications prescribed.

RESULTS

The mean ACT score was 12.8 where doctors assessed the patients as being 'not controlled' and 20.7 where doctors assessed the patients as being 'controlled'. Half of the patients classified themselves as being 'not controlled' (ACT score <20, category 1), while doctors classified only 33% of patients as being 'not controlled'. Although only 7% of patients disagreed with the doctor's classification of 'not controlled', 29% disagreed with the doctor's assessment of being 'controlled'. There was a significant difference in ACT score between the sexes (p < 0.0001). Most therapeutic interventions (with the exception of combination products [ICS + LABA]) performed poorly with regard to level of control.

CONCLUSION

This study suggests that asthma still appears to be relatively poorly controlled in South Africa, although levels of patient control appear to have improved compared to previous surveys, and confirms that physicians and patients differ in their assessments of asthma control.

Atopy in HIV-infected children in Pretoria

INTRODUCTION

The development or aggravation of a pre-existing atopic state in patients with human immunodeficiency virus (HIV) has not been thoroughly investigated in South Africa. HIV-infected adults have been shown to have a higher prevalence of atopy in some international studies, but this has not been documented in children.

METHODS

A prospective convenience sample of 50 children aged between 3 months and 12 years attending the Tshwane District Hospital Paediatric HIV Clinic in Pretoria was recruited. Their personal and family histories of atopy, World Health Organization (WHO) HIV clinical staging and Centers for Disease Control (CDC) immunological staging with CD4 counts were documented. An age- and sex-matched control group of 50 HIV-negative children was included. Skin prick tests (SPTs) to identify common aeroallergens were conducted on all patients.

RESULTS

One hundred children were enrolled, with 50 in each group. Ten per cent of the HIV-infected patients compared with 16% of controls had positive SPTs to aeroallergens. A higher percentage of the HIV-infected patients had chronic rhinitis and eczema (60% and 68%, respectively). There was no relationship between CD4 count and positive SPTs (p = 0.61), mean log CD4 count and presence of reported asthma (p = 0.71), and CD4 count and presence of reported dermatitis (p = 0.84). The CD4 count was not statistically different between children with and without a family history of atopy (p = 0.68).

CONCLUSION

It appears that the stage of HIV disease does not influence the development or expression of allergy. There is a high prevalence of dermatitis and chronic rhinitis in HIV-infected children, probably not atopic in origin.

Short-range ultrasonic communications in air using quadrature modulation

A study has been undertaken of ultrasonic communications methods in air, using a quadrature modulation method. Simulations were first performed to establish the likely performance of quadrature phase shift keying over the limited bandwidth available in an ultrasonic system. Quadrature phase shift keying modulation was then implemented within an experimental communication system, using capacitive ultrasonic sources and receivers. The results show that such a system is feasible in principle for communications over distances of several meters, using frequencies in the 200 to 400 kHz range.

A near-infrared (NIR) technique for imaging food materials

The results of imaging experiments in food materials are presented, using near-infrared wavelengths. The technique uses a modulated source and a lock-in amplifier detection circuit to give a high sensitivity to changes in through-transmission signal levels. This is shown to lead to a set of images, whereby the internal content of various foods can be imaged. Examples are presented of the detection of foreign bodies, both metallic and nonmetallic, to illustrate the imaging performance.

Guideline for the diagnosis, prevention and treatment of paediatric ventilator-associated pneumonia

OBJECTIVE

Ventilator-associated pneumonia (VAP) has been poorly studied in South Africa, but is likely to be a significant problem, with resulting increased morbidity and mortality in the paediatric intensive care unit population. This guideline is intended to review the evidence and recommendations for prevention and management of VAP in children and to provide, where possible, clear advice to aid the care of these children, to limit costly and unnecessary therapies and--importantly--limit inappropriate use of antimicrobial agents,

EVIDENCE

The Working Group was constituted. Literature on the aetiology, prevention and management of paediatric VAP is reviewed.

RECOMMENDATIONS

Evidence-based clinical practice guidelines are provided for VAP diagnosis and prevention in South Africa. In addition, the current status of antimicrobial use has been reviewed and clear recommendations are set out.

New insights on growth mechanisms of protein clusters at surfaces: an AFM and simulation study

Despite its relevance to a wide range of technological and fundamental areas, a quantitative understanding of protein surface clustering dynamics is often lacking. In inorganic crystal growth, surface clustering of adatoms is well described by diffusion-aggregation models. In such models, the statistical properties of the aggregate arrays often reveal the molecular scale aggregation processes. We investigate the potential of these theories to reveal hitherto hidden facets of protein clustering by carrying out concomitant observations of lysozyme adsorption onto mica surfaces, using atomic force microscopy, and Monte Carlo simulations of cluster nucleation and growth. We find that lysozyme clusters diffuse across the substrate at a rate that varies inversely with size. This result suggests which molecular scale mechanisms are responsible for the mobility of the proteins on the substrate. In addition the surface diffusion coefficient of the monomer can also be extracted from the comparison between experiments and simulations. While concentrating on a model system of lysozyme-on-mica, this 'proof of concept' study successfully demonstrates the potential of our approach to understand and influence more biomedically applicable protein-substrate couples.

Influenza guideline for South Africa--update 2008

OBJECTIVE

The South African Thoracic Society, in conjunction with interested stakeholders, published a Guideline for Influenza Management in Adults in 1999. This year the South African Thoracic Society (SATS) identified the need to revise that guideline for the following reasons: * To indicate the viral strains that are to be incorporated into the vaccine for the 2008 season * To add important new data regarding treatment of influenza * To add a section on influenza in children * To clarify issues in managing and preventing influenza in HIV-infected individuals.

INFLUENZA VIRUS

The influenza virus genus belongs to the family orthomyxoviridae. The haemagglutinin (HA) protein is the outermost protein, responsible for attachment to the host receptor, and is critical in determining the host's immune response to the virus. Changes in the antigenic epitopes of HA therefore allow the virus to escape the host's specific immune response. The genus is classified into three types, A, B and C, on the basis of the antigenic epitopes of the nucleoprotein (NP). Type A, which is widespread in nature in birds and mammals, is the most important type clinically and epidemiologically. It is further divided into subtypes on the basis of the antigenic epitopes of the HA and neuraminidase (NA) proteins. Each of the human subtypes H1N1, H2N2 and H3N2 are further subdivided into strains on the basis of more subtle antigenic properties of the HA protein.

INFLUENZA VACCINATION

Influenza vaccine is the mainstay of influenza prevention strategies. All persons who are at high risk of influenza and its complications because of underlying medical conditions or who are receiving regular medical care for conditions such as chronic pulmonary and cardiac disease, chronic renal diseases, neuromuscular diseases, diabetes mellitus and similar metabolic disorders, and individuals who are immunosuppressed (including HIV-infected persons with CD4 counts above 100 cells/microl and HIV-infected children with CD4 counts >15%), should be vaccinated. Vaccines should be given from at least 2 months prior to the onset of autumn (March in South Africa). The recommended vaccine formulation for 2008 is: * A/Solomon Islands/3/2006 (H1N1) (IVR-145) * A/Brisbane/10/2007 (H3N2) (IVR-147) * B/Florida/4/2006 or B/Brisbane/3/2007.

TREATMENT OF INFLUENZA

Influenza illness is characterised by the acute onset of systemic and respiratory signs occurring in autumn or winter. Recommendations for the Prevention and Control of Influenza have indicated that neither amantadine nor rimantadine should be used for the treatment or chemoprophylaxis of influenza A. NA inhibitors are an important adjunct to influenza vaccination, in both the prevention and treatment of influenza. Because of concerns about the possibility of the development of viral resistance with overuse of these agents, it is recommended that NA inhibitors in the treatment of influenza should be reserved for high-risk or sicker influenza patients.

Mechanisms and dynamics of protein clustering on a solid surface

A methodology for discovering the mechanisms and dynamics of protein clustering on solid surfaces is presented. In situ atomic force microscopy images are quantitatively compared to Monte Carlo simulations using cluster statistics to differentiate various models. We study lysozyme adsorption on mica as a model system and find that all surface-supported clusters are mobile, not just the monomers, with diffusion constant inversely related to cluster size. The surface monomer diffusion constant is measured to be D(1) approximately 9 x 10(-16) cm(2) s(-1), such a low value being difficult to measure using other techniques.

Comparison of the relative analgesic efficacies of epidural or intramuscular diamorphine following total knee arthroplasty

BACKGROUND AND OBJECTIVES

Debate has proliferated as to the true site of action of opioids when placed in the epidural space. The aim of this study was to compare the analgesic effects of a bolus of diamorphine given by the epidural or intramuscular route.

METHODS

Sixty patients having elective primary total knee replacements were recruited and randomized to receive epidural or intramuscular diamorphine. A lumbar epidural catheter was sited and 10 mL of bupivacaine 0.5% wt vol-1 was injected. Patients subsequently received diamorphine 5 mg into the epidural space or as an intramuscular injection. Patient-controlled analgesia with intravenous morphine was used for postoperative analgesia. The primary outcome measures included time to first patient-controlled analgesia use and total morphine consumption in 24 h. Secondary end-points considered possible treatment complications.

RESULTS

All primary end-points showed significant differences in favour of epidural diamorphine. Medians for times to first patient-controlled analgesia use and total 24 h morphine requirements were significantly different (P < 0.001) at 418 vs. 198 min and 11 vs. 39 mg, respectively. There were no significant differences in secondary end-points.

CONCLUSIONS

This study has shown the superior analgesic efficacy of epidural diamorphine when compared to intramuscular injection.