Direct imaging of two-state dynamics on the amorphous silicon surface

Amorphous silicon is an important material, amidst a debate whether or not it is a glass. We produce amorphous Si surfaces by ion bombardment and vapor growth, and image discrete Si clusters which hop by two-state dynamics at 295 K. Independent of surface preparation, these clusters have an average diameter of ∼5 atoms. Given prior results for metallic glasses, we suggest that this cluster size is a universal feature. The hopping activation free energy of 0.93±0.15  eV is rather small, in agreement with a previously untested surface glass model. Hydrogenation quenches the two-state dynamics, apparently by increasing surface crystallinity.

Skin histopathology, including a significant itch response, associated chemically-induced contact hypersensitivity reactions in the mouse are, in part, a consequence of skin infiltrating eosinophils (163.16)

Atopic dermatitis and allergic contact dermatitis are two of the most common skin diseases. In both diseases, eosinophils have been suggested as potential contributors of the pathologies linked with these skin conditions. Our goal was to establish a causative relationship between the inflammatory response of chemically induced contact hypersensitivity and eosinophil-mediated activities. Wild type and eosinophil-less PHIL mice were sensitized and challenged with 2,4-dinitrochlorobenzene (DNFB) or alternatively trimellitic anhydride (TMA). Time lapsed videography was used to capture the number of itching events associated with treatment. Immunohistochemistry for eosinophils and nerves was performed to correlate the effect of dermatitis on innervation and eosinophil accumulation in these mice. Our studies showed that in both the DNFB and TMA models a robust eosinophil infiltrate occurred that was accompanied by copious levels of eosinophil degranulation. More importantly, these studies demonstrated that metrics of inflammation (e.g., induced ear swelling (i.e., thickness)) was reduced in PHIL mice relative to wild type. Our observations were also directly correlative with a loss of nerve growth and branching in PHIL mice. These data implicate eosinophils as contributors to the pathologies linked with chemically-induced contact hypersensitivity, including the induced itch responses associated with these models.

Solving the low dimensional Smoluchowski equation with a singular value basis set

Reaction kinetics on free energy surfaces with small activation barriers can be computed directly with the Smoluchowski equation. The procedure is computationally expensive even in a few dimensions. We present a propagation method that considerably reduces computational time for a particular class of problems: when the free energy surface suddenly switches by a small amount, and the probability distribution relaxes to a new equilibrium value. This case describes relaxation experiments. To achieve efficient solution, we expand the density matrix in a basis set obtained by singular value decomposition of equilibrium density matrices. Grid size during propagation is reduced from (100-1000)(N) to (2-4)(N) in N dimensions. Although the scaling with N is not improved, the smaller basis set nonetheless yields a significant speed up for low-dimensional calculations. To demonstrate the practicality of our method, we couple Smoluchowsi dynamics with a genetic algorithm to search for free energy surfaces compatible with the multiprobe thermodynamics and temperature jump experiment reported for the protein alpha(3)D.

Direct imaging of room temperature optical absorption with subnanometer spatial resolution

Optical absorption can detect individual molecules and nanostructures even in dissipative or strongly quenching environments where fluorescence signals are weak. Here we image optical absorption of individual carbon nanotubes with subnanometer resolution. We show that we can discriminate adjacent nanotubes on a length scale far below the diffraction limit. Then we compare optical absorption imaging of a defect in a single carbon nanotube (CNT) with conventional scanning tunneling microscopy (STM) and conventional current-voltage scan (I-V) bandgap profiles. We directly visualize the penetration depth σ' = 0.9 ± 0.3 nm of the CNT exciton state into the smaller bandgap region of the defect and derive a size σ = 1.8 ± 0.6 nm for the exciton state. Optical absorption provides a spectroscopic map of molecules simultaneously with conventional STM.

Expedited partner therapy for Chlamydia trachomatis at the community pharmacy

OBJECTIVE

Expedited partner treatment (EPT) for uncomplicated Chlamydia trachomatis at the pharmacy is an alternative approach to partner notification that has not yet been evaluated within the UK. The aim of this study was to evaluate EPT for partners using pharmacies in Lothian.

DESIGN

A pilot study over 18 months.

SETTING

Selected healthcare settings and community pharmacies in Lothian, Scotland, UK.

POPULATION

Sexual partners of index cases with uncomplicated C. trachomatis.

METHODS

Index cases with uncomplicated C. trachomatis were given a pharmacy voucher to pass onto sexual partners. Partners could redeem vouchers for free treatment (azithromycin) at one of 90 pharmacies in the area.

MAIN OUTCOME MEASURES

The main outcome measure was the proportion of vouchers redeemed. Secondary outcomes included patient satisfaction, as determined at a telephone follow-up of a subgroup of female index cases from one study site, 1 month later.

RESULTS

In total 577 vouchers were issued to chlamydia-positive index patients of mean age 22.9 years (range 15-47 years). A total of 231 vouchers were redeemed (40%), at a median of 2 days after issue. Only 4% of partners attended a clinic for treatment. Most index patients surveyed reported that partners were satisfied with this method of treatment (48 out of 55; 87%).

CONCLUSIONS

Expedited partner treatment for uncomplicated chlamydia at a pharmacy is a popular choice, and increases options on where, when and how partners are treated.

The Freeman femoral component with hydroxyapatite coating and retention of the neck: an update with a minimum follow-up of 17 years

The outcome at ten years of 100 Freeman hip stems (Finsbury Orthopaedics, Leatherhead, United Kingdom) retaining the neck with a proximal hydroxyapatite coating in a series of 52 men (six bilateral) and 40 women (two bilateral), has been described previously. None required revision for aseptic loosening. We have extended the follow-up to 20 years with a minimum of 17 years. The mean age of the patients at total hip replacement was 58.9 years (19 to 84). Six patients were lost to follow-up, but were included up to their last clinical review. A total of 22 patients (22 hips) had died, all from causes unrelated to their surgery. There have been 43 re-operations for failure of the acetabular component. However, in 38 of these the stem was not revised since it remained stable and there was no associated osteolysis. Two of the revisions were for damage to the trunnion after fracture of a modular ceramic head, and in another two, removal of the femoral component was because of the preference of the surgeon. In all cases the femoral component was well fixed, but could be extracted at the time of acetabular revision. In one case both components were revised for deep infection. There has been one case of aseptic loosening of the stem which occurred at 14 years. This stem had migrated distally by 7.6 mm in ten years and 8.4 mm at the time of revision at which stage it was found to be rotationally loose. With hindsight this component had been undersized at implantation. The survivorship for the stem at 17 years with aseptic loosening as the endpoint was 98.6% (95% confidence interval 95.9 to 100) when 62 hips were at risk. All remaining stems had a satisfactory clinical and radiological outcome. The Freeman proximally hydroxyapatite-coated femoral component is therefore a dependable implant and its continued use can be recommended.

A natural missing link between activated and downhill protein folding scenarios

We propose protein PTB1 : 4W as a good candidate for engineering into a downhill folder. PTB1 : 4W has a probe-dependent thermal unfolding curve and sub-millisecond T-jump relaxation kinetics on more than one time scale. Its refolding rate in denaturant is a non-linear function of denaturant concentration (curved chevron plot). Yet at high denaturant concentration its unfolding is probe-independent, and the folding kinetics can be fitted to a single exponential decay. The domain appears to fold via a mechanism between downhill folding and activated folding over several small barriers, and when denaturant is added, one of these barriers greatly increases and simplifies the observed folding to apparent two-state kinetics. We predict the simplest free energy function consistent with the thermal denaturation and kinetics experiments by using the singular value Smoluchowski dynamics (SVSD) model. PTB1 : 4W is a natural 'missing link' between downhill and activated folding. We suggest mutations that could move the protein into the downhill folding limit.

Severe tibial bone loss in revision total knee replacement managed with structural femoral head allograft: a prospective case series from the Royal London Hospital

Large tibial bone defects may cause problems at the time of revision total knee replacement. We report on 15 patients (15 knees) followed at a mean of 5.4 years (33-115 months) who underwent revision total knee replacement for severe tibial bone loss using shaped femoral head allograft and Freeman-Samuelson revision components (Zimmer, Winterthur, Switzerland). The mean American Knee Society Score pre-operatively was 22.7 points (0-45) increasing to a mean of 77.2 points (15-95) after operation. The survivorship for the series at 6 years was seven out of nine knees. One patient required an above knee amputation at 3.5 years, whilst another underwent a second revision TKR procedure at 3.4 years. Thirteen knees did not require further surgery and showed a mean time for allograft incorporation of 1.9 years (12-36 months) with no component migration. Severe tibial bone loss at the time of revision TKR surgery is a difficult problem to treat. Our case series demonstrates that when shaped femoral heads are used as structural allograft along with long stemmed components a successful result can be achieved.

The Medial Rotation total knee replacement: a clinical and radiological review at a mean follow-up of six years

We describe the survivorship of the Medial Rotation total knee replacement (TKR) at ten years in 228 cemented primary replacements implanted between October 1994 and October 2006, with their clinical and radiological outcome. This implant has a highly congruent medial compartment, with the femoral component represented by a portion of a sphere which articulates with a matched concave surface on the medial side of the tibial insert. There were 78 men (17 bilateral TKRs) and 111 women (22 bilateral TKRs) with a mean age of 67.9 years (28 to 90). All the patients were assessed clinically and radiologically using the American Knee Society scoring systems. The mean follow-up was for six years (1 to 13) with only two patients lost to follow-up and 34 dying during the period of study, one of whom had required revision for infection. There were 11 revisions performed in total, three for aseptic loosening, six for infection, one for a periprosthetic fracture and one for a painful but well-fixed replacement performed at another centre. With revision for any cause as the endpoint, the survival at ten years was 94.5% (95% CI 85.1 to 100), and with aseptic loosening as the endpoint 98.4% (95% CI 93 to 100). The mean American Knee Society score improved from 47.6 (0 to 88) to 72.2 (26 to 100) and for function from 45.1 (0 to 100) to 93.1 (45 to 100). Radiological review failed to detect migration in any of the surviving knees. The clinical and radiological results of the Medial Rotation TKR are satisfactory at ten years. The increased congruence of the medial compartment has not led to an increased rate of loosening and continued use can be supported.

Preferred strategies of men and women for managing chlamydial infection

OBJECTIVES

To determine men and women's preferred strategies for managing chlamydial infection: partner notification (patient referral), postal testing kit (PTK) or patient-delivered partner medication (PDPM).

DESIGN

Interviewer-conducted questionnaires (women) and anonymous, self-administered questionnaires (men).

POPULATION

Women infected with chlamydia who were participating in a randomised study assigning partners to patient referral, PTK or PDPM. Men attending genitourinary medicine, family planning and fracture clinics in Edinburgh.

METHODS

Men and women were asked their preferred strategy for testing/treating sexual partners (patient referral, PTK or PDPM) if they or their partner had a positive chlamydia test. Women were also asked the reasons for their choice and whether partners were satisfied with the intervention received.

MAIN OUTCOME MEASURES

Reported preferences of men and women for testing/treating partners.

RESULTS

Response rates were 97 and 81% for the women's questionnaires at study entry and 6 months, respectively, and 81% for the men's questionnaires. Of 174 women responding, 67% preferred PDPM for partners and 57% would prefer PDPM for themselves. The main reasons were that PDPM allows simpler, more convenient and faster treatment. Women reported that 65% of partners were satisfied with whichever intervention they received. Of 293 men responding, 70% would choose patient referral for partners and 53% would prefer patient referral for themselves. Men previously tested for chlamydia were significantly more likely to choose PDPM (n = 22) than those never tested (n = 7); P < 0.001. Only 3% of women and 9% of men preferred PTKs for partners.

CONCLUSION

The results suggest that women prefer PDPM and men, at least hypothetically, prefer patient referral. PTK appears unpopular with both sexes.

Influences of reduced expression of maternal bone morphogenetic protein 2 on mouse embryonic development

Bone morphogenetic protein 2 (BMP2) was originally found by its osteoinductive ability, and recent genetic analyses have revealed that it plays critical roles during early embryogenesis, cardiogenesis, decidualization as well as skeletogenesis. In the course of evaluation of the conditional allele for Bmp2, we found that the presence of a neo cassette, a selection marker needed for gene targeting events in embryonic stem cells, in the 3' untranslated region of exon 3 of Bmp2, reduced the expression levels of Bmp2 both in embryonic and maternal mouse tissues. Some of the embryos that were genotyped as transheterozygous for the floxed allele with the neo cassette over the conventional null allele (fn/-) showed a lethal phenotype including defects in cephalic neural tube closure and ventral abdominal wall closure. The number of embryos exhibiting these abnormalities was increased when, due to different genotypes, expression levels of Bmp2 in maternal tissues were lower. These results suggest that the expression levels of Bmp2 in both embryonic and maternal tissues influence the normal neural tube closure and body wall closure with different thresholds.

The early radiological follow-up of a medial rotational design of total knee arthroplasty

The objective of this study was to investigate the hypothesis that the increased constraint of a medial rotational knee promotes earlier loosening of the prosthesis. All patients with a Freeman-Samuelson 1000 knee arthroplasty (medial pivot design), (group 1), or a Freeman-Samuelson Modular knee arthroplasty, (group 2), with a minimum follow-up of 2 years (mean follow-up 4 years) were identified from our unit's arthroplasty database, and matched as closely as possible for age, length of follow-up and pre-operative diagnosis. Standardised anteroposterior and lateral radiographs were analysed for component migration and radiolucent lines as recommended by the Knee Society. There were 48 knees in each group. There were no failures in group 2. There was one failure requiring revision of the tibial component in group 1. There was no significant difference in overall radiolucent line scores between the two groups (p=0.66, at 5 years). Progressive radiolucent lines were detected in similar numbers of patients in both groups (FS1000 8/48, FSM 7/48, p=0.84). Our early radiological survey suggests that the increased constraint of the medial pivot knee prosthesis does not result in an increased incidence of radiographic loosening.

A qualitative study of overdose responses among Chicago IDUs

Background

Opioid overdose is a leading cause of death among injection drug users. Over half of injection drug users report at least one nonfatal overdose during their lifetime. Death from opioid overdose rarely occurs instantaneously, but rather over the course of one to three hours, allowing ample time for providing life-saving measures. In response to the prevalence of overdoses in the U.S., there are a growing number of overdose prevention and naloxone distribution programs targeting the injection drug using community.

Methods

We explored injection drug users' experiences with opioid overdose response, examining differences between overdose responses in which naloxone was and was not used. The current study is based upon qualitative interviews (N = 31) with clients of the Chicago Recovery Alliance needle exchange program who had witnessed an overdose in the past six months. The interviews explored participants' drug use history, personal overdose experiences, and details concerning their last witnessed overdose. Verbatim transcripts were coded and analyzed thematically to address major study questions.

Results

Participants were 81% were male, their median age was 38. They reported having injected a median of 10 years and having witnessed a median of six overdoses in their lifetime. All described overdoses were recognized and responded to quickly. None of the overdoses resulted in a fatality and naloxone was successfully administered in 58% of the last witnessed overdoses. Administering naloxone for the first time was characterized by trepidation, but this feeling dissipated as the naloxone quickly took effect. Emergency medical personnel were called in 10 of the 31 described overdoses, including four in which participants administered naloxone. The overwhelming majority of experiences with police and paramedics were positive

Conclusion

Overall, our small study found that the overdose prevention efforts build on extensive knowledge possessed by IDUs. Teaching IDUs how to use naloxone is an effective risk reduction strategy.

Influence of 4- and 6-color flow cytometers and acquisition/analysis softwares on the determination of lymphocyte subsets in HIV infection

BACKGROUND AND OBJECTIVES

Lymphocyte immunophenotyping provides valuable information for the diagnosis and monitoring of patients with cellular immunodeficiencies, such as HIV/AIDS. In this study, we have assessed the influence of 4-color and 6-color flow cytometers, and respective analytical softwares on the enumeration of lymphocytes in HIV infected individuals.

METHODS

The expression of various cell surface markers on lymphocytes was measured from the EDTA blood of 66 HIV infected patients on the FACSCalibur (4-color) and FACSCanto (6-color) flow cytometers. Percentage of lymphocytes expressing a particular cell surface marker was analyzed on FACSCalibur using the Cell Quest Pro software (v 5.2), while the analysis on FACSCanto was done using FACSCanto (v 1.0.3) and FACSDiva (v 4.1) softwares respectively.

RESULTS

The data shows significantly higher mean CD3 T-cell counts on FACSCalibur, Cell Quest Pro (1,864 +/- 1,044 cells/microl) as compared to FACSCanto (1,840 +/- 1,040 cells/microl) (P < 0.05). The CD4 T-cell counts were also higher on FACSCalibur, Cell Quest Pro (885 +/- 770 cells/microl), and FACSDiva (892 +/- 773 cells/microl) versus FACSCanto (867 +/- 767 cells/microl) (P < 0.05). FACSCalibur, Cell Quest Pro, and FACSDiva showed similar values except for CD8 T-lymphocytes where FACSDiva had significantly lower values (P < 0.05). The B-cell counts were unaffected when either of the instruments or softwares were used, while the natural killer (NK) cells (CD16 + 56 positive cells) showed similar trend like CD3 and CD4 counts with significant differences in the mean cell counts between FACSCalibur, Cell Quest Pro (240 +/- 165 cells/microl), and FACSDiva (238 +/- 163 cells/microl) versus FACSCanto with higher NK cell counts (260 +/- 176 cells/microl).

CONCLUSIONS

The enumeration of lymphocyte subsets was comparable between FACSCalibur, Cell Quest Pro, and FACSDiva, based analysis and it was significantly different than FACSCanto software based analysis. Our observations suggest that FACSDiva software should be preferred over the FACSCanto software for immunophenotyping on FACSCanto flow cytometer and the laboratories should report the instrument and software used for the specimen analysis while reporting immunophenotyping results.

Willingness of gynaecologists, doctors in family planning, GPs, practice nurses and pharmacists to adopt novel interventions for treating sexual partners of women with chlamydia

OBJECTIVE

To determine willingness of health professionals to adopt new interventions for treating sexual partners of women with chlamydia.

DESIGN

Anonymous, self-administered questionnaires of doctors, practice nurses and community pharmacists regarding novel testing/treatment options for partners of women with chlamydia.

SETTING

Local (Scotland) and national (UK) clinical meetings in reproductive health, and community pharmacy (Lothian).

POPULATION

Doctors (general practice, gynaecology, family planning) and practice nurses who were delegates at selected meetings in reproductive health and community pharmacists attending pharmacy meetings.

METHODS

Doctors and nurses were invited to complete a questionnaire indicating their preferred strategy for testing/treating sexual partners of women with chlamydia if given choice of partner notification, postal testing kit (PTK), patient delivered partner medication (PDPM) with azithromycin or combined PDPM and PTK. Community pharmacists were invited to complete a questionnaire regarding their willingness to introduce chlamydia testing and treatment services.

MAIN OUTCOME MEASURES

Reported preferences of doctors and nurses for partner testing/treatment strategies and willingness of pharmacists to offer new services.

RESULTS

Questionnaires were completed by 211 doctors, 73 practice nurses and 50 pharmacists. The most popular choice of doctors (30%) and nurses (23%) was a combination of PDPM with PTK, with partner notification the least popular (8 and 3%, respectively). One in four doctors had previously used PDPM for treating partners. Most pharmacists were willing to supply free PTKs (98%), offer testing (75%) and treatment services (100%) and give women PDPM for partners (80%).

CONCLUSION

Relevant health professionals, who are increasingly involved in managing chlamydia, are largely in favour of introducing new strategies for treating sexual partners.

BMP type I receptor ALK2 is essential for proper patterning at late gastrulation during mouse embryogenesis

Bone morphogenetic proteins (BMPs) have multiple functions during vertebrate development. Previously, it was shown that BMP type I receptor ALK2 (also known as ACVRI, ActRI, or ActRIA) was important for normal mouse gastrulation by deleting exon 4 or exon 5 of Alk2. Recently, flanking exon 7 by loxP sites generated a conditional allele for Alk2. To assess whether the deletion of exon 7 causes functional null of ALK2, and does not produce a dominant negative form or a partially functional form of ALK2, we performed a comparative analysis between Alk2 homozygous mutant embryos with an exon 5 deletion (Alk2(Delta5/Delta5)) and embryos with an exon 7 deletion (Alk2(Delta7/Delta7)). Both Alk2(Delta5/Delta5) and Alk2(Delta7/Delta7) mutants showed identical morphological gastrulation defects. Histological examinations and molecular marker analyses revealed identical abnormal gastrulation phenotypes in Alk2(Delta5/Delta5) and Alk2(Delta7/Delta7) mutants. Although Fgf8 was expressed in the primitive streak of Alk2(Delta5/Delta5) and Alk2(Delta7/Delta7) mutants, Brachyury, Wnt3a, and Tbx6 were dramatically downregulated in Alk2(Delta5/Delta5) and Alk2(Delta7/Delta7) mutants. These results indicate that deletion of exon 7 for Alk2 leads to a functionally null mutation in vivo, and Alk2 is crucial for sustaining the proper gastrulation events in early mouse embryogenesis.

The shortcomings of computer-aided measurement of migration for the prediction of failure of three forms of acetabular fixation by survival analysis and migration study to ten years

We studied, to ten years, migration by vertical displacement and angular change using a digitizer and standard radiographs and survival of three methods of acetabular fixation in primary hip replacement. Two implants were uncemented metal-backed components, one version of which was hydroxyapatite-coated. Both types had 28 mm polyethylene inserts. The third type was a cemented all-polyethylene cup with a 28 mm internal diameter. All cups articulated with a Freeman neck-retaining stem. The purpose was to see if the early migration data predicted the long-term outcome and could be used to forecast implants that would fail for the purpose of pre-market assessment. No statistical differences were found between the groups in the parameters studied. At the threshold accuracies of our migration measurements (three millimetres and three degrees) at three years, we could not identify components that would subsequently fail. However, migration less than these threshold values and the absence of radiolucent lines were strongly associated with implant survival at ten years. Our system was insufficiently accurate for pre-market surveillance.;

An evaluation of contaminated estuarine sites using sediment quality guidelines and ecological assessment methodologies

Toxic contaminants may enter estuarine ecosystems through a variety of pathways. When sediment contaminant levels become sufficiently high, they may impact resident biota. One approach to predict sediment-associated toxicity in estuarine ecosystems involves the use of sediment quality guidelines (ERMs, ERLs) and site-specific contaminant chemistry while a second approach utilizes site-specific ecological sampling to assess impacts at the population or community level. The goal of this study was to utilize an integrated approach including chemical contaminant analysis, sediment quality guidelines and grass shrimp population monitoring to evaluate the impact of contaminants from industrial sources. Three impacted sites and one reference site were selected for study. Grass shrimp populations were sampled using a push-netting approach. Sediment samples were collected at each site and analyzed for metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and pesticides. Contaminant levels were then compared to sediment quality guidelines. In general, grass shrimp population densities at the sites decreased as the ERM quotients increased. Grass shrimp densities were significantly reduced at the impacted site that had an ERM exceedance for chromium and the highest Mean ERM quotient. Regression analysis indicated that sediment chromium concentrations were negatively correlated with grass shrimp density. Grass shrimp size was reduced at two sites with intermediate levels of contamination. These findings support the use of both sediment quality guidelines and site-specific population monitoring to evaluate the impacts of sediment-associated contaminants in estuarine systems.

Nephrogenic systemic fibrosis among liver transplant recipients: a single institution experience and topic update

Nephrogenic systemic fibrosis (NSF) is a recently characterized systemic fibrosing disorder developing in the setting of renal insufficiency. NSF's rapidly progressive nature resulting in disability within weeks of onset makes early diagnosis important. Two reports of NSF after liver transplantation are known of. We present three cases of NSF developing within a few months after liver transplantation and review the current literature. Loss of regulatory control of the circulating fibrocyte, its aberrant recruitment, in a milieu of renal failure and a recent vascular procedure appear important in its development. Known current therapies lack consistent efficacy. Only an improvement in renal function has the greatest likelihood of NSF's resolution. Delayed recognition may pose a significant barrier to functional recovery in the ubiquitously deconditioned liver transplant patient. Early recognition and implementation of aggressive physical therapy appear to have the greatest impact on halting its progression.

Generation of a mouse with conditionally activated signaling through the BMP receptor, ALK2

BMP signaling plays pleiotropic roles in various tissues. Transgenic mouse lines that overexpress BMP signaling in a tissue-specific manner would be beneficial; however, production of each tissue-specific transgenic mouse line is labor-intensive. Here, using a Cre-loxP system, we generated a conditionally overexpressing mouse line for BMP signaling through the type I receptor ALK2 (alternatively known as AVCRI, ActRI, or ActRIA). By mating this line with Cre-expression mouse lines, Cre-mediated recombination removes an intervening floxed lacZ expression cassette and thereby permits the expression of a constitutively active form of Alk2 (caAlk2) driven by a ubiquitous promoter, CAG. Tissue specificity of Cre recombination was monitored by a bicistronically expressed EGFP following Alk2 cDNA. Increased BMP signaling was confirmed by ectopic phosphorylation of SMAD1/5/8 in the areas where Cre recombination had occurred. The conditional overexpression system described here provides versatility in investigating gene functions in a tissue-specific manner without having to generate independent tissue-specific transgenic lines.

The dental emergency responder: Expanding the scope of dental practice

BACKGROUND

Natural disasters, the potential for terrorism and weapons-of-mass-destruction events occurring within the continental United States necessitate that all licensed health care providers understand the National Incident Management System and be able to contribute to inoculation, mass casualty assistance and triage care of the populace.

CONCLUSIONS

Health care and political leaders constantly revise "all hazard" response plans, using the available health care assets that local, state and federal agencies bring to emergency events. Illinois Public Act 49-409 modifies the scope of dental practice within Illinois to allow for a dental emergency responder (DER).

PRACTICE IMPLICATIONS

The DER is a dentist or dental hygienist "acting within the bounds of his or her license when providing care during a declared local, state or national emergency."

The effect of a neck-retaining femoral implant on leg-length inequality following total hip arthroplasty

The aim of this study was to assess whether a femoral component which retained the neck reduced the incidence of leg-length inequality following total hip arthroplasty. A retrospective review was undertaken of 130 consecutive primary total hip arthroplasties performed between April 1996 and April 2004 using such an implant. There were 102 suitable patients for the study. Standardised pre- and post-operative pelvic radiographs were measured by an independent investigator to the nearest millimetre.

The leg-length inequality was reduced from a mean pre-operative value of −0.71 cm to a mean of 0.11 cm post-operatively. Of the 102 patients 24 (23.5%) had an equal leg-length post-operatively, and 95 (93.1%) had a leg-length inequality between −1 cm and 1 cm.

A rapid method for identifying high-risk patients consenting for HIV testing: introducing The Edinburgh Risk Assessment Table for HIV testing

Lack of time for conducting standard HIV pre-test counselling has been reported as a barrier to HIV testing. Use of a risk assessment table will identify high-risk patients to whom pre-test counselling may be limited. The aim of this study is to investigate the performance of a Risk Assessment Table for HIV testing designed in the Department of Genitourinary (GU) Medicine, Edinburgh. A prospective study was carried out on patients attending the Department of GU Medicine, Edinburgh between June 30th 2002 and July 1st 2003, who consented to HIV testing. Patients with any risk factor had standard pre-and post-test counselling. Those without any risk factor were tested and provided with leaflets on HIV testing.A total of 3337 patients were tested in the study period and 727 (22%) had risk factor for HIV infection. Twenty-nine patients (0.9%) were HIV-infected. The Risk Assessment Table failed to identify two infected patients. Routine use of the Risk Assessment Table saves time of the medical staff by only providing pre-test counselling to high-risk patients.

Impact of annual legume 'break' crops on the yield and quality of canola in comparison with the impact on yield of wheat

This study investigated the yield, oil and protein content of canola in response to alternative single-season legume crops, and compared the yield response with that of wheat. Two field trials were conducted in consecutive years at Wagga Wagga on the South West Slopes of New South Wales. The soil type was Red Kandasol. The legume treatments were field pea and vetch managed for silage production, vetch managed for green manure, a mixture of aerial seeding clovers (Berseem, Arrowleaf, Persian: 6 : 3 : 3) managed for silage, hay or green manure, and field pea and narrow-leaf lupin managed for grain. There was one wheat treatment managed for grain. In terms of growing season rainfall, the rainfall-use efficiency of canola was low and similar to that achieved on farms (5.1 kg/ha.mm rainfall). Yields of canola were less than potential water-limited yields and the canola equivalent wheat yields were less than comparative wheat yields. The constraint(s) on canola yield meant that nitrogen-limited yield potential was not reached, and in contrast to wheat in adjacent plots, there was no relationship between canola seed yield and soil mineral nitrogen available during seedling establishment of canola. However, relative to other legume treatments, antecedent crops of the clover mix depressed yield and total oil content, particularly in one year. It was concluded that under field conditions that constrained canola productivity to that similar to on-farm productivity, wheat may make more efficient use of legume nitrogen than canola. Were canola to be used as the response crop, antecedent legumes of vetch or pea, rather than aerial seeding clover, would give higher potential yield and total oil content of the canola.

Failure of a "screw-in" acetabular component: ten-year results, survivorship analysis, and the prediction of failure

The Rotalok screw-in threaded acetabular component was prospectively reviewed with 10-year clinical and radiological follow-up for 60 patients. Nine patients died and 5 were lost to follow-up. Clinically, 28 patients were pain-free, 13 had mild pain, and 3 had moderate pain. Thirteen patients underwent revision for loosening and 3 required revision but were unfit. Superior migration, angular migration, and zone lucency were measured radiologically. Cumulative survival was 70.75% with revision surgery as the end point and 60% with combined clinical failure and revision as the end point. Angular migration of 3 degrees or more was a significant predictor of clinical failure and revision (P < .0001), with 5 degrees being very highly predictive with a sensitivity of 0.72 and a specificity of 1.00. Revision was associated with younger patients (P = .03) and autograft use without screw stabilization (P = .024). The high failure rate of the Rotalok necessitates careful clinical and radiological follow-up, with asymptomatic radiological angular migration often the first predictor of failure.

Quality assessment of South African herbal medicines by means of HPLC fingerprinting

An estimated 70% of South Africans regularly use traditional plant medicines. Incorporation of these medicines within the formal health care system, which is the stated intention of the Health Ministry, requires the establishment of standards for quality control. Except in the case of a handful of South African plant species, such standards are lacking. Of central importance with respect to quality control is correct identification of the species concerned, whether in the fresh, dried or powdered state. In cases where botanical identification is impossible, high performance liquid chromatography (HPLC) with diode array detection (DAD), offers an alternative qualitative profile and is being increasingly used for the authentication of crude drugs or their extracts. As a contribution to establishing quality standards for South African plant species used as traditional medicines, HPLC-DAD "fingerprints" of 60 commonly-used species have been generated in our laboratory. One of these species is presented here, together with UV spectra of individual components represented by major peaks in the HPLC profiles.

The significance of surface changes on retrieved femoral components after total knee replacement

We investigated the changes in surface roughness of retrieved femoral components in 18 men and four women at revision knee surgery. The mean age at revision was 68.4 years and the mean period of implantation was for 55.6 months. Eighteen implants were retrieved for aseptic loosening and four for infection. The surface changes in the articulating areas were inspected visually and the roughness (Ra) analysed with a profilometer. Parallel scratching and burnishing were the two main forms of damage. The mean Ra measurements in the articulating areas showed no statistically significant difference when compared with those in a control area on either side of the patellar groove at the apex of the femoral flange. This suggests that it is not essential to revise a well-fixed and correctly aligned femoral component where the polished surface has become burnished or bears fine parallel scratches, if the revision is conducted solely for failure of the tibial component.

The use of tranexamic acid to reduce blood loss during total hip arthroplasty: an observational study

INTRODUCTION

To test the hypothesis that the fall in haemoglobin following total hip arthroplasty is reduced by tranexamic acid administration.

PATIENTS AND METHODS

A cohort of 64 patients were studied, 32 received tranexamic acid 20 mg/kg on induction. Surgery was performed by the senior author in a standardised fashion. Haemoglobin levels were measured 2 weeks pre- and 3 days postoperatively. Any complications were noted. The study group was matched using the bone and joint research database for age, sex, procedure, disease and pre-operative haemoglobin level.

RESULTS

In the group receiving no tranexamic acid, the mean fall in haemoglobin was 3.8 g/dl (CI of mean 3.4-4.3) and in the group treated with tranexamic acid 2.8 g/dl (CI of mean 2.5-3.2) P < 0.05. Complications included one non-fatal pulmonary embolus in the tranexamic acid group.

CONCLUSIONS

The administration of 20 mg/kg of tranexamic acid on induction of surgery is an effective method of reducing the haemoglobin fall following hip arthroplasty.

Isolation and Characterization of the ALP1 Protease from Aspergillus fumigatus and Its Protein Inhibitor from Physarium polycephalum

It is known that Aspergillus fumigatus secretes a serine protease ALP1 of the subtilisin family in the presence of extracellular protein substrates. We found conditions of A. fumigatus culturing that provide a high ALP1 activity inside cells without induction by extracellular proteins. The identity of the properties of the secreted and intracellular enzymes was shown. A thermostable protein inhibitor of the ALP1 protease was isolated from the plasmodium of the myxomycete Physarum polycephalum. Its molecular mass is 32-33 kDa. The inhibitor inhibits the ALP1 protease activity with IC50 of 0.14 microM. This protein was also shown to be a less efficient inhibitor of the activity of HIV-1 protease (IC50 2.5 microM). The English version of the paper: Russian Journal of Bioorganic Chemistry, 2005, vol. 31, no. 3; see also http://www.maik.ru.

Hip resurfacing following previous proximal femoral osteotomy

Until recently, the options for patients with a degenerative hip and a previous femoral osteotomy included arthrodesis, total hip arthroplasty with osteotomy or CADCAM total hip arthroplasty. Technological improvements have allowed the reintroduction of hip resurfacing. We report the results of hip resurfacing in four patients with previous valgus or extension proximal femoral osteotomies. Patients were assessed for pre and post-operative pain, walking distance and range of movement. All patients had an abnormal angulation, of the femoral neck, of 30 degrees or more in either coronal or sagittal plane. They are within the severe group of disordered proximal femoral anatomy according to Harris et al. The mean age at operation was 32 years (range 30 - 34). The mean follow-up was 3 years (range 1 - 8). Postoperatively no patient required analgesia and all patients had a minimum uninterrupted walking ability of 30 or more minutes with the exception of the patient who had undergone previous leg lengthening. We recommend this comparatively straightforward operation compared to current alternatives. (Hip International 2005; 15: 119-22).

Trachipleistophora hominis infection in the myocardium and skeletal muscle of a patient with AIDS

OBJECTIVES

To review the literature relevant to microsporidial infection of muscle and to describe a case of human microsporidial infection involving both skeletal and cardiac muscle.

METHODS

Samples from an AIDS patient with myositis have been examined by light and electron microscopy.

RESULTS

We describe the findings at autopsy of a 47 year old Australian male with late stage AIDS, who had skeletal and cardiac muscle involvement with the microsporidian Trachipleistophora hominis. This is the third definitively identified case of human T. hominis infection and the first to describe infection of the myocardium.

CONCLUSIONS

Microsporidial infection of muscle is rare in humans, but more work is needed to elucidate both the organisms and routes of transmission of this group of parasitic protozoa.

A survey of the perspectives of specialist palliative care providers in the UK of inpatient respite

One of the major reasons for admission of patients to hospital in late stage disease is the inability of carers to continue to provide care at home. Specialist palliative care services have typically admitted patients for acute symptom control, terminal care and respite care to benefit them and their carers. This paper reports the results of a cross-sectional survey of inpatient respite care provision provided by specialist palliative care services and hospices in the UK. A structured questionnaire was mailed to 242 clinical services managers listed in the Hospice Information Directory in 2003. A 69% response rate was achieved. The questionnaire explored the nature of respite services, their purpose, organization, delivery and examined definitions used. The analysis indicated that 80% of the sample provided inpatient respite care. Most inpatient respite admissions were planned, of fixed duration (7-14 days) and were intended to benefit patients and carers. There was some evidence that respite provision was regarded as a lower priority than admissions for symptom control and terminal care, and that patients' needs were prioritized over those of carers. Only 10% of services conducted regular, routine audit, with very few seeking the views of service users. Findings suggest that carers' needs and wishes are not prioritized by specialist palliative care services offering inpatient respite, which may mean that they find it difficult to maintain their caregiving roles over longer disease trajectories or in the face of overwhelming demands.

Acute exacerbation of chronic bronchitis: a primary care consensus guideline

OBJECTIVE

To develop consensus on appropriate treatment for acute exacerbation of chronic bronchitis (AECB). CHARACTERISTICS AND ETIOLOGY: Patients with chronic bronchitis have an irreversible reduction in maximal airflow velocity and a productive cough on most days of the month for 3 months over 2 consecutive years. An AECB is characterized by a period of unstable lung function with worsening airflow and other symptoms. Most (80%) cases of AECB are due to infection, with half due to aerobic bacteria. The remaining 20% are due to noninfectious causes such as environmental factors or medication nonadherence.

MANAGEMENT

Supportive care should be provided to all patients, which might include removal of irritants, use of a bronchodilator, oxygen, hydration, use of a systemic corticosteroid, and chest physical therapy. Antibacterial treatment should be reserved for patients with at least 1 key symptom (ie, increased dyspnea, sputum production, sputum purulence) and 1 risk factor (ie, age > or = 65 years, forced expiratory volume in 1 second < 50% of the predicted value, > or = 4 AECBs in 12 months, 1 or more comorbidities). A newer macrolide, extended-spectrum cephalosporin, or doxycycline is appropriate for an exacerbation of moderate severity, and high-dose amoxicillin/clavulanate or a respiratory fluoroquinolone should be used for a severe exacerbation. There has been increasing antibacterial resistance by the 3 most prevalent pathogens (Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis).

CONCLUSION

Although all AECB patients should receive supportive care, only patients with at least 1 key symptom and 1 risk factor should receive antibiotic therapy.

Cryptococcal meningitis in two apparently immunocompetent Maltese patients

Two cases of cryptococcal meningitis occurring in immunocompetent men are described. The first case involves a farmer in whom cryptococcal meningitis was rapidly diagnosed using direct microscopy, latex antigen tests and culture of cerebrospinal fluid (CSF). In the second case, initial mycological tests on CSF (direct microscopy and culture) were repetitively negative and latex antigen tests gave unconvincing results. The patient was started on triple antituberculosis therapy, on which he improved immediately; therapy was continued for 1 year with the patient remaining well. However, within 1 week of stopping therapy, he had to be readmitted with neurological signs and symptoms. Culture of CSF this time yielded Cryptococcus neoformans and the antigen test was consistently positive. These are the first reported cases of cryptococcal meningitis in immunocompetent patients in Malta.