Complication rates after direct anterior vs posterior approach for hip hemiarthroplasty in elderly individuals with femoral neck fractures

BACKGROUND

Dislocation rates after hemiarthroplasty reportedly vary from 1% to 17%. This serious complication is associated with increased morbidity and mortality rates. Approaches to this surgery are still debated, with no consensus regarding the superiority of any single approach.

AIM

To compare early postoperative complications after implementing the direct anterior and posterior approaches (PL) for hip hemiarthroplasty after femoral neck fractures.

METHODS

This is a comparative, retrospective, single-center cohort study conducted at a university hospital. Between March 2008 and December 2018, 273 patients (a total of 280 hips) underwent bipolar hemiarthroplasties (n = 280) for displaced femoral neck fractures using either the PL (n = 171) or the minimally invasive direct anterior approach (DAA) (n = 109). The choice of approach was related to the surgeons' practices; the implant types were similar and unrelated to the approach. Dislocation rates and other complications were reviewed after a minimum follow-up of 6 mo.

RESULTS

Both treatment groups had similarly aged patients (mean age: 82 years), sex ratios, patient body mass indexes, and patient comorbidities. Surgical data (surgery delay time, operative time, and blood loss volume) did not differ significantly between the groups. The 30 d mortality rate was higher in the PL group (9.9%) than in the DAA group (3.7%), but the difference was not statistically significant (P = 0.052). Among the one-month survivors, a significantly higher rate of dislocation was observed in the PL group (14/154; 9.1%) than in the DAA group (0/105; 0%) (P = 0.002). Of the 14 patients with dislocation, 8 underwent revision surgery for recurrent instability (posterior group), and one of them had 2 additional procedures due to a deep infection. The rate of other complications (e.g., perioperative and early postoperative periprosthetic fractures and infection-related complications) did not differ significantly between the groups.

CONCLUSION

These findings suggest that the DAA to bipolar hemiarthroplasty for patients with femoral neck fractures is associated with a lower dislocation rate (< 1%) than the PL.

Acute total hip replacement by direct anterior approach combined with intrapelvic fixation for geriatric acetabular fracture of the anterior column

Management of anterior column acetabular fracture in the elderly is challenging. Open reduction and internal fixation do not allow early weight bearing and are associated with a high risk of failure compared to younger patients. Therefore, acute fixation and total hip arthroplasty may be an option. This technical note describes a combined procedure: anterior intrapelvic approach for fracture fixation and a direct anterior approach to the hip for THR. Fracture reduction and arthroplasty were achievable in all five patients. The mean operative time was 289min, and the mean blood loss was 2120mL. At short term, no complication was noticed. Combining these two "muscle-sparing" approaches could help manage anterior column fractures in elderly patients. Level of evidence: IV.

Treatment of Hip Microinstability with Arthroscopic Capsular Plication: A Retrospective Case Series

Purpose

Hip microinstability is defined as hip pain with a snapping and/or blocking sensation accompanied by fine anatomical anomalies. Arthroscopic capsular plication has been proposed as a treatment modality for patients without major anatomic anomalies and after failure of properly administered conservative treatment. The purpose of this study was to determine the efficacy of this procedure and to evaluate potential predictors of poor outcome.

Materials and Methods

A review of 26 capsular plications in 25 patients was conducted. The mean postoperative follow-up period for the remaining patients was 29 months. Analysis of data included demographic, radiological, and interventional data. Calculation of pre- and postoperative WOMAC (Western Ontario and McMaster Universities Osteoarthritis) index was performed. Pre- and postoperative sports activities and satisfaction were also documented. A P<0.05 was considered significant.

Results

No major complications were identified in this series. The mean pre- and postoperative WOMAC scores were 62.6 and 24.2, respectively. The WOMAC index showed statistically significant postoperative improvement (P=0.0009). The mean satisfaction rate was 7.7/10. Four patients with persistent pain underwent a periacetabular osteotomy. A lateral center edge angle ≤21° was detected in all hips at presentation. We were not able to demonstrate any difference in postoperative evolution with regard to the presence of hip dysplasia (P>0.05), probably because the sample size was too small.

Conclusion

Capsular plication can result in significant clinical and functional improvement in carefully selected cases of hip microinstability.

A low dislocation rate after revision total hip arthroplasty performed through the anterior approach

BACKGROUND

Dislocation is a major complication in revision total hip arthroplasties. This study aimed to evaluate the dislocation rate, complications, and functional scores of revision total hip arthroplasty performed through the direct anterior approach.

METHODS

Between January 2014 and March 2020, 84 patients undergoing revision total hip arthroplasty were retrospectively reviewed. All operations were performed through the direct anterior approach. At the final follow-up, incidences of dislocation, reoperation, acute deep infections, periprosthetic fractures and psoas impingement were assessed. The median postoperative Oxford Hip Score was also calculated.

RESULTS

At revision surgery, the mean age was 66 ± 12 years (range, 28-91). During an average follow-up of 4.2 ± 1.2 years, reoperation rate for major complications in the non-infected revisions was 15% (n = 11), including five acute deep infections (7%), four periprosthetic fractures (5%), one dislocation and one psoas impingement (1%). The median postoperative Oxford Hip Score was 39 (interquartile range = 14).

CONCLUSION

In our series, revision total hip arthroplasty through direct anterior approach was associated with a very low dislocation rate, acceptable complication rates and good functional results. Our results suggest that this procedure is safe and reliable.

TRIAL REGISTRATION

Ethical approval for this study was obtained, before enrollment of the first participant, by CUB Erasme's research ethics committee (P2020/323) and C.H.U Ambroise Paré's research ethics committee.

Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

2021 opinion from the CUROPF on THE efficacy and safety of mid-urethral slings used in women WITH urinary stress incontinence

OBJECTIVE

To determine the usefulness of mid-urethral slings (MUS) in the surgical management of women presenting with urinary stress incontinence (USI) METHOD: A consensus committee of multidisciplinary experts (CUROPF) was convened and focused on PICO questions concerning the efficacy and safety of MUS surgery compared to other procedures and concerning which approach (retropubic (RP) vs transobturator (TO)) should be proposed as a first-line MUS surgery for specific subpopulations (obese; intrinsic sphincteric deficiency (ISD); elderly) RESULTS: As compared to other procedures (urethral bulking agents, traditional slings and open colposuspension), the MUS procedure should be proposed as the first-line surgical therapy (strong agreement). MUS surgery can be associated with complications and proper pre-operative informed consent is mandatory (strong agreement). Mini-slings (SIS/SIMS) should only be proposed in clinical trials (strong agreement). Both RP and TO approaches may be proposed for the insertion of MUS (strong agreement). However, if the woman is willing to accept a moderate increase in per-operative risk, the RP approach should be preferred (strong agreement) since it is associated with higher very long-term cure rates and as it is possible to completely remove the sling surgically if a severe complication occurs. The RP approach should be used for the insertion of MUS in a woman presenting with ISD (strong agreement). Either the RP or TO approach should be used for the insertion of MUS in an obese woman presenting with USI (strong agreement). In very obese women (BMI ≥35-40kg/m²), weight loss should be preferred prior to MUS surgery and bariatric surgery should be discussed (strong agreement) CONCLUSION: The current Opinion provides an appropriate strategy for both the selection of patients and the best therapeutic approach in women presenting with USI.

[Complications of mid-urethral sling - A review from the Committee for Female Urology and Pelviperineology for the French Association of Urology]

INTRODUCTION

Placement of a mid-urethral sling is the gold standard in the surgical management of stress urinary incontinence in women in France. The cure rate of this material is no longer to be demonstrated, but the per- and post-operative complications are currently the subject of a growing controversy not only in Europe but also across the Channel and across the Atlantic, having led to the modification of operative indications. In France, recommendations are also evolving with a stricter framework for indications for surgery by multidisciplinary consultation meeting and an obligation for postoperative follow-up in the short and long term.

OBJECTIVES

In this context, CUROPF realized a review of the literature bringing together the available scientific evidence concerning the occurrence of per- and post-operative complications relating to the installation of mid urethral sling. The bibliographic search was carried out using the Medline database and 123 articles were selected.

RESULTS

Analysis of the data highlights various complications, depending on the implanted material, the patient and the indication for surgery. The retro-pubic mid urethral sling provides more bladder erosion during surgery (up to 14%), more suprapubic pain (up to 4%) and more acute urinary retention (up to 19,7%) and postoperative dysuria (up to 26%). The trans obturator mid-urethral sling is responsible for more vaginal erosion during the operation (up to 10,9%), more lower limb pain of neurological origin (up to 26,7%). The risk of developing over active bladder is similar in both procedures (up to 33%). But these risks of complications must be balanced by the strong impact of urinary incontinence surgery on the overall quality of life of these women.

CONCLUSION

Thus, surgical failure and long term complications exist but should not limit the surgical management of stress urinary incontinence with mid urethral tape. Women should be treated with individualized decision-making process and long-term follow -up is necessary.

Serious complications and recurrences after pelvic organ prolapse surgery for 2309 women in the VIGI-MESH registry

OBJECTIVE

To assess the incidence of serious complications and reoperations for recurrence after surgery for pelvic organ prolapse (POP) and compare the three most common types of repair.

DESIGN

Prospective cohort study using a registry.

SETTING

Nineteen French surgical centres.

POPULATION

A total of 2309 women participated between 2017 and 2019.

METHODS

A multivariate analysis including an inverse probability of treatment weighting approach was used to obtain three comparable groups.

MAIN OUTCOME MEASURES

Serious complications and subsequent reoperations for POP recurrence.

RESULTS

The median follow-up time was 17.6 months. Surgeries were native tissue vaginal repairs (n = 504), transvaginal mesh placements (n = 692) and laparoscopic sacropexies with mesh (n = 1113). Serious complications occurred among 52 women (2.3%), and reoperation for POP recurrence was required for 32 women (1.4%). At 1 year the cumulative weighted incidence of serious complications was 1.8% for native tissue vaginal repair, 3.9% for transvaginal mesh and 2.2% for sacropexy, and the rates for reoperation for recurrence of POP were 1.5, 0.7 and 1.1%, respectively. Compared with native tissue vaginal repair, the risk of serious complications was higher in the transvaginal mesh group (weighted hazard ratio, wHR 3.84, 95% CI 2.43-6.08) and the sacropexy group (wHR 2.48, 95% CI 1.45-4.23), whereas the risk of reoperation for prolapse recurrence was lower in both the transvaginal mesh (wHR 0.22, 95% CI 0.13-0.39) and sacropexy (wHR 0.29, 95% CI 0.18-0.47) groups.

CONCLUSIONS

Our results suggest that native tissue vaginal repairs have the lowest risk of serious complications but the highest risk of reoperation for recurrence. These results are useful for informing women and for shared decision making.

TWEETABLE ABSTRACT

Laparoscopic sacropexy had fewer serious complications than transvaginal mesh and fewer reoperations for recurrence than vaginal repair.

Evaluation of hip arthroscopy using a hip-specific distractor for the treatment of femoroacetabular impingement

Background and study aims

Hip arthroscopy using an orthopaedic traction table has been associated with traction-related neurovascular complications. Since the use of a hip-specific distractor for performing hip arthroscopy hasn’t been associated with those specific complications we hypothesized that a hip-specific distractor might facilitate the learning curve of hip arthroscopy for beginner surgeons.

Material and methods

We reviewed retrospectively the first 56 hip arthroscopies performed to treat femoro-acetabular impingement using a hip-specific distractor. We tried to analyse the learning curve of this procedure using operative time, peri- and postoperative complications, hospital stay and patient satisfaction. We also evaluated pre- and postoperative sports activities and tried to identify some factors as poor postoperative prognostic factors.

Results

Only 1 major complication occurred. No traction-related complications have been encountered. The curves analysing intervention time and postoperative satisfaction rate showed improvement after 30 cases performed. In all cases, we were able to perform the whole planned gesture without difficulties accessing the hip joint.

Conclusion

The hip-specific distractor is a safe and reproducible method in performing hip arthroscopy without any traction-related complications or time limits.

[Vaginal LASER therapy for genito-urinary disorders: A systematic review and statement from the Committee for Female Urology and Pelviperineology of the French Association of Urology]

INTRODUCTION

Vaginal LASER therapy is increasingly used in the field of urogynecology, but several points remain unclear. Our goal was to produce a systematic review of available evidence and provide a critical appraisal of available data.

METHODS

A systematic review until march 2020 was conducted using PubMed/MEDLINE, Cochrane and Embase databases. All studies about vaginal LASER use in the field of urogynecology were included.

RESULTS

Forty studies have been included (8 for genitourinary syndrome of menopause, 19 for stress urinary incontinence, 3 for overactive bladder, 7 for urogenital prolapse, 3 for other indications). Data were heterogeneous, and level of evidence was weak or very weak. Few studies were comparative, and only 3 were randomized). Mild improvement of symptoms and quality of life and limited satisfaction were seen for genitourinary syndrome, stress urinary incontinence, overactive bladder and prolapse. Few adverse events were reported. However, major methodological biases were noted regarding efficacy and safety evaluation. No long-term results were available.

CONCLUSIONS

While Vaginal LASER therapy seem to provide encouraging results, the level of evidence supporting its use was weak, especially regarding long-term outcomes. Studies of better quality are warranted before any recommendation can be made. Current use should be limited to clinical research.

Aseptic Loosening after Total Hip Arthroplasty in an Acromegalic Patient: A Case Report

Introduction:

Acromegaly is a rare disorder characterized by excess secretion of growth hormone and its principle mediator, insulin-like growth factor-1. Although acromegaly is frequently associated with osteoarthritis, the outcome of arthroplasty in this population is not documented.

Case Report:

We report here a case of aseptic loosening of an uncemented total hip arthroplasty acetabulum in an acromegalic patient that was revised with a cemented cup. It has been suggested that the incidence of this complication is increased in other pathology with a similarly high bone-turnover (e.g., Paget’s disease), but this complication has however not yet been reported in the setting of acromegaly.

Conclusion:

Although coincidence cannot be ruled out, multiple metabolic hypotheses could account for an altered osseointegration process in the presence of acromegaly, which could lead to a higher risk of loosening.

Surgical treatment for periacetabular metastatic lesions

INTRODUCTION

Periacetabular bone metastasis present with severe pain and functional loss leading to a poor quality of life. Surgical treatment remains challenging.

MATERIAL AND METHODS

We reviewed all cases operated at our institution. We analyzed pain scores and functional status as well as complications and their risk factors.

RESULTS

Thirty-five patients underwent curettage and cemented reconstruction. Mean surgical time was 168 min. Mean surgical blood losses were 3150 ml. Major complications were encountered in 23% and minor complications in 29% of cases. We found a significant pain relief (p < 0.0001) and improvement in functional status in the postoperative period (p < 0.0001). A Harrington grade 4 lesion was correlated with a higher complication rate (p-value = 0.002).

CONCLUSIONS

In this series we were able to show that surgical management is an effective option in the treatment of metastatic bone disease to the pelvis. However, this treatment is very complex and associated with very high complication rates. Therefore, adequate patient selection and preoperative management is advocated.

Intussusception in Children: A Clinical Review

Intussusception is the most common cause of small bowel obstruction in young infants. Therefore a high index of suspicion and thorough knowledge of this condition is of major importance to be able to diagnose and treat this potentially life threatening condition. In this review we describe epdidemiology, etiology and clinical symptoms of intussuception. Furthermore, we describe diagnostic modalties, especially ultrasonography as the primary choice for diagnosis. In addition, non-operative treatment with different types of enema reduction techniques, and operative treatment by laparotomy and laparoscopy, and outcomes have been reviewed.

Small solid renal masses: characterization by diffusion-weighted MRI at 3 T

AIM

To describe the appearance of small solid renal lesions (≤3 cm) on diffusion-weighted magnetic resonance imaging (MRI) and to determine whether ADC measurements may help to differentiate benign from malignant small solid renal masses.

METHODS AND MATERIALS

Thirty-five patients with 47 small renal masses (23 malignant, 24 benign) who underwent 3 T MRI of the kidney using diffusion-weighted sequences (b values of 0 and 1000 s/mm(2)) were retrospectively evaluated. Qualitative and quantitative analysis of diffusion-weighted images was performed.

RESULTS

Most lesions were hyperintense to kidney on high b-value diffusion-weighted images and hypointense on apparent diffusion coefficient (ADC) map. The mean ADC of the lesions was significantly lower than that of kidney (1.22 ± 0.3 versus 1.85 ± 0.12 mm(2)/s; p < 0.005). The mean ADC was significantly different between renal cell carcinomas (1.2 ± 0.01 mm(2)/s), metastases (1.25 ± 0.04 mm(2)/s), angiomyolipoma (1.07 ± 0.3 mm(2)/s) and oncocytomas (1.56 ± 0.08 mm(2)/s; p < 0.05). The mean ADC of clear cell renal cell carcinomas was significantly different from that of non-clear cell renal cell carcinomas (1.38 ± 0.34 versus 0.83 ± 0.34 mm(2)/s; p < 0.005). No significant difference was found between mean ADC of fat containing and minimal fat angiomyolipomas (1.06 ± 0.48 versus 1.11 ± 0.33 mm(2)/s).

CONCLUSION

Small solid renal masses are hyperintense on high b value and have different ADC values.

Australian study on public knowledge of human genetics and health

AIMS

This study was designed to obtain data on public understanding of genetic concepts in the adult population of Western Australia. It explored knowledge of genetic risk of disease, inheritance, biology, determinism, and factors that predict relatively higher genetic knowledge within the general population.

METHOD

A cross-sectional telephone survey of 1,009 respondents.

RESULTS

Most members of the Western Australian community are aware of basic genetic concepts and the link between genes, inheritance, and risk of disease. Significantly fewer understand the biological mechanisms underlying these concepts and there was some misconception around the meaning of 'increased genetic risk'. The odds of higher genetic knowledge (>19 out of 24 questions correct) were greater among those with 12 years or more education (OR = 3.0), those aged 18-44 years (OR = 2.3), women (OR = 2.0), those with annual household income of AUD 80,000 or more (OR = 1.8), and those who had talked with someone (OR = 1.7) or searched the internet (OR = 1.6) for information on genes and health.

CONCLUSIONS

This study provides evidence of an association between social location and public knowledge of human genetic concepts related to health and disease. This is consistent with previous findings and raises questions about the acquisition of textbook genetics knowledge within socio-cultural contexts. The impact of misconceptions about genetic concepts on the uptake of preventive health behaviors requires further investigation, as does the level of genetics knowledge that is required to empower informed participation in individual and societal decisions about genetics and health.

Should HIV discordant couples have access to assisted reproductive technologies?

In this paper we identify and evaluate arguments for and against offering assisted reproductive technologies (ART), specifically IVF, to HIV discordant couples (male partner HIV positive, female partner HIV negative). The idea of offering ART to HIV discordant couples generates concerns about safety and public health and raises questions such as: what is an acceptable level of risk to offspring and should couples who want this assistance be subject to selection criteria; should they undergo scrutiny about their suitability as parents when those who are able to conceive naturally face no such scrutiny and people with other illnesses are given access to ART? We conclude that offering ART to HIV discordant couples is likely to produce more benefit than harm and violates no ethical principles. Nevertheless, a decision to deny treatment need not constitute unjustified discrimination.

Amyotrophic lateral sclerosis: current understanding

Amyotrophic lateral sclerosis (ALS), or motor neuron disease (MND) as it is usually termed in the United Kingdom, is a fatal degenerative disease resulting in progressive weakness and wasting of voluntary muscles. The disease is caused by degeneration of upper motor neurons in the motor cortex and of lower motor neurons in the brainstem and spinal cord. This combined loss of function causes spastic paralysis, flaccid muscle weakness, wasting, and fasciculations. The disease process spares the sensory, autonomic, and oculomotor neurons. ALS is the most common of the MND syndromes in adults. Although the cause of ALS is unknown, there is evidence that the excitatory neurotransmitter glutamate plays an important role in neuronal cell death in the disease. Several risk factors, such as exposure to welding and soldering, inhalation of lead vapor, exposure to chemicals, and electrical trauma are postulated as contributing to the pathogenesis of ALS. About 90% of all ALS patients have the sporadic form. Approximately 20% of all familial ALS cases are associated with mutations of the copper/zinc superoxide dismutase-1 gene. What is not clear is what factors contribute to the causation of the more common sporadic cases. The drug riluzole has neuroprotective effects in ALS and is the only disease-specific treatment available to date. Riluzole has been approved by the National Institute for Clinical Excellence for use in the National Health Service of the United Kingdom. Other treatments are aimed at managing the devastating symptoms of ALS.

Genetic transformation of Trametes versicolor to phleomycin resistance with the dominant selectable marker shble

We have developed a stable, DNA-mediated transformation system for the white-rot basidiomycete Trametes versicolor based on the dominant selectable marker shble (phleomycin resistance). We employed a vector containing the selectable marker under control of expression sequences from the basidiomycete Schizophyllum commune and a polyethylene glycol/ CaCl2 protoplast-fusion technique to introduce the transforming DNA. This transformation system generated stable phleomycin-resistant transformants at a frequency of four to seven transformants/microg of transforming DNA.

Polyphasic microbial community analysis of petroleum hydrocarbon-contaminated soils from two northern Canadian communities

The cold-adapted bacterial communities in petroleum hydrocarbon-contaminated and non-impacted soils from two northern Canadian environments, Kuujjuaq, Que., and Alert, Nunavut, were analyzed using a polyphasic approach. Denaturing gradient gel electrophoresis (DGGE) separation of 16S rDNA PCR fragments from soil total community DNA revealed a high level of bacterial diversity, as estimated by the total number of bands visualized. Dendrogram analysis clustered the sample sites on the basis of geographical location. Comparison of the overall microbial molecular diversity suggested that in the Kuujjuaq sites, contamination negatively impacted diversity whereas in the Alert samples, diversity was maintained or increased as compared to uncontaminated controls. Extraction and sequencing analysis of selected 16S rDNA bands demonstrated a range of similarity of 86-100% to reference organisms, with 63.6% of the bands representing high G+C Gram-positive organisms in the order Actinomycetales and 36.4% in the class Proteobacteria. Community level physiological profiles generated using Biolog GN plates were analyzed by cluster analysis. Based on substrate oxidation rates, the samples clustered into groups similar to those of the DGGE dendrograms, i.e. separation based upon geographic origin. The coinciding results reached using culture-independent and -dependent analyses reinforces the conclusion that geographical origin of the samples, rather than petroleum contamination level, was more important in determining species diversity within these cold-adapted bacterial communities.

Preformed dimeric state of the sensor protein VirA is involved in plant--Agrobacterium signal transduction

Plant signal molecules such as acetosyringone and certain monosaccharides induce the expression of Agrobacterium tumefaciens virulence (vir) genes, which are required for the processing, transfer, and possibly integration of a piece of the bacterial plasmid DNA (T-DNA) into the plant genome. Two fo the vir genes, virA and virG, belonging to the bacterial two-component regulatory system family, control the induction of vir genes by plant signals. virA encodes a membrane-bound sensor kinase protein and virG encodes a cytoplasmic regulator protein. Although it is well established from in vitro studies that the signal transduction process involves VirA autophosphorylation and subsequent phosphate transfer to VirG, the structural state of the VirA protein involved in signal transduction is not understood. In this communication, we describe an in vivo crosslinking approach which provides physical evidence that VirA exists as a homodimer in its native configuration. The dimerization of VirA neither requires nor is stimulated by the plant signal molecule acetosyringone. We also present genetic data which support the hypothesis that VirA exists as a homodimer which is the functional state transducing the plant signal in an intersubunit mechanism. To our knowledge, this report provides the first evidence that a bacterial membrane-bound sensor kinase exists and functions as a homodimer in vivo.

Characterization of a tumor necrosis factor-alpha inhibitor activity in cancer patients

To evaluate the feasibility of tumor necrosis factor-alpha (TNF-alpha) treatment of lung cancer patients, we chose the malignant cells contained in their pleural effusions as a first convenient target. We found, however, that a TNF-alpha inhibitor (TNF-alpha I) activity was present in both patient sera and pleural fluids. We therefore compared the TNF-alpha I activity present in patients with benign or malignant pleural effusions using a bioassay of TNF-alpha inhibition and partially characterized it. A high TNF-alpha I activity characterizes cancer patients with sera levels twice as high as the control level measured for blood bank donors (2.54 +/- 1.28 versus 1.19 +/- 0.38) and with even higher levels in pleural fluids (3.75 +/- 1.83). In contrast, patients with benign pleural effusions present similar levels of TNF-alpha I activity, at about the control level, in both their sera and pleural fluids (1.37 +/- 0.98 versus 1.16 +/- 0.85). A high TNF-alpha I activity is consistently found in cancer patients but is only released in vitro by leukocytes. It is most likely related to recently purified TNF-alpha inhibitors that, as soluble shed fragments of TNF receptors, may function as traps for TNF molecules. This study suggests that tumors may evade TNF cytotoxic action by modulating systemic levels of TNF and implies a reassessment of TNF therapy in cancer patients.

Dexamethasone modulation of tumour necrosis factor-alpha (cachectin) release by activated normal human alveolar macrophages

Recurrent infections of the lower respiratory tract are a frequent and serious side-effect of chronic corticosteroid treatment. Since alveolar macrophages (AM) are currently thought to play a central role in the protection of the lower respiratory tract against infectious agents, it is likely that a steroid-induced deficiency of AM is involved in this process. In this respect, when activated, AM are major producers of tumour necrosis factor-alpha (TNF or cachectin), a versatile cytokine with several biological properties including antiviral and anti-infectious activities. A deficit of TNF production induced by corticosteroid may be one mechanism of the sensitivity to infections. Thus normal human AM obtained by bronchoalveolar lavage were pretreated with dexamethasone (DXM) before activation with lipopolysaccharides (LPS) and the amounts of TNF released in culture were quantified. Pretreatment with DXM resulted in a marked decrease of TNF release in a dose-dependent fashion. In contrast, when AM were activated with LPS before DXM treatment, TNF release by AM was suppressed in a more limited fashion. Thus DXM suppression of LPS-activated AM ability to release TNF may play a role in the susceptibility to infections of patients chronically treated with corticosteroids.

Dexamethasone modulation of tumour necrosis factor-alpha (cachectin) release by activated normal human alveolar macrophages

Recurrent infections of the lower respiratory tract are a frequent and serious side-effect of chronic corticosteroid treatment. Since alveolar macrophages (AM) are currently thought to play a central role in the protection of the lower respiratory tract against infectious agents, it is likely that a steroid-induced deficiency of AM is involved in this process. In this respect, when activated, AM are major producers of tumour necrosis factor-alpha (TNF or cachectin), a versatile cytokine with several biological properties including antiviral and anti-infectious activities. A deficit of TNF production induced by corticosteroid may be one mechanism of the sensitivity to infections. Thus normal human AM obtained by bronchoalveolar lavage were pretreated with dexamethasone (DXM) before activation with lipopolysaccharides (LPS) and the amounts of TNF released in culture were quantified. Pretreatment with DXM resulted in a marked decrease of TNF release in a dose-dependent fashion. In contrast, when AM were activated with LPS before DXM treatment, TNF release by AM was suppressed in a more limited fashion. Thus DXM suppression of LPS-activated AM ability to release TNF may play a role in the susceptibility to infections of patients chronically treated with corticosteroids.