Microtubules under mechanical pressure can breach dense actin networks

The crosstalk between the actin network and microtubules is essential for cell polarity. It orchestrates microtubule organization within the cell, driven by the asymmetry of actin architecture along the cell periphery. The physical intertwining of these networks regulates spatial organization and force distribution in the microtubule network. Although their biochemical interactions are becoming clearer, the mechanical aspects remain less understood. To explore this mechanical interplay, we developed an in vitro reconstitution assay to investigate how dynamic microtubules interact with various actin filament structures. Our findings revealed that microtubules can align and move along linear actin filament bundles through polymerization force. However, they are unable to pass through when encountering dense branched actin meshworks, similar to those present in the lamellipodium along the periphery of the cell. Interestingly, immobilizing microtubules through crosslinking with actin or other means allow the buildup of pressure, enabling them to breach these dense actin barriers. This mechanism offers insights into microtubule progression towards the cell periphery, with them overcoming obstacles within the denser parts of the actin network and ultimately contributing to cell polarity establishment.

Microtubules self-repair in living cells

Microtubule self-repair has been studied both in vitro and in vivo as an underlying mechanism of microtubule stability. The turnover of tubulin dimers along the microtubule has challenged the pre-existing dogma that only growing ends are dynamic. However, although there is clear evidence of tubulin incorporation into the shaft of polymerized microtubules in vitro, the possibility of such events occurring in living cells remains uncertain. In this study, we investigated this possibility by microinjecting purified tubulin dimers labeled with a red fluorophore into the cytoplasm of cells expressing GFP-tubulin. We observed the appearance of red dots along the pre-existing green microtubule within minutes. We found that the fluorescence intensities of these red dots were inversely correlated with the green signal, suggesting that the red dimers were incorporated into the microtubules and replaced the pre-existing green dimers. Lateral distance from the microtubule center was similar to that in incorporation sites and in growing ends. The saturation of the size and spatial frequency of incorporations as a function of injected tubulin concentration and post-injection delay suggested that the injected dimers incorporated into a finite number of damaged sites. By our low estimate, within a few minutes of the injections, free dimers incorporated into major repair sites every 70 μm of microtubules. Finally, we mapped the location of these sites in micropatterned cells and found that they were more concentrated in regions where the actin filament network was less dense and where microtubules exhibited greater lateral fluctuations.

Hematopoietic progenitors polarize in contact with bone marrow stromal cells in response to SDF1

The fate of hematopoietic stem and progenitor cells (HSPCs) is regulated by their interaction with stromal cells in the bone marrow. However, the cellular mechanisms regulating HSPC interaction with these cells and their potential impact on HSPC polarity are still poorly understood. Here we evaluated the impact of cell–cell contacts with osteoblasts or endothelial cells on the polarity of HSPC. We found that an HSPC can form a discrete contact site that leads to the extensive polarization of its cytoskeleton architecture. Notably, the centrosome was located in proximity to the contact site. The capacity of HSPCs to polarize in contact with stromal cells of the bone marrow appeared to be specific, as it was not observed in primary lymphoid or myeloid cells or in HSPCs in contact with skin fibroblasts. The receptors ICAM, VCAM, and SDF1 were identified in the polarizing contact. Only SDF1 was independently capable of inducing the polarization of the centrosome–microtubule network.

Unilateral open extravesical ureteral reimplanation with contralateral dextronomer/hyaluronic acid injection performed as an outpatient therapy

INTRODUCTION

Historically, patients with unilateral high-grade vesicoureteral reflux (VUR) and contralateral low-grade or resolved VUR have been treated with bilateral intravesical ureteral reimplantation, which requires postoperative admission. If the high-grade VUR side is treated alone, then the contralateral side is at risk of developing recurrent or worsening VUR. Bilateral subureteric injection of dextronomer/hyaluronic acid (DHA) is another option that can be performed as an outpatient therapy, but a single injection is less effective for high-grade VUR.

OBJECTIVE

The safety and efficacy of an outpatient combination of open extravesical ureteral reimplantation (EVUR) and contralateral DHA injection were investigated.

STUDY DESIGN

A retrospective review of children who had concomitant EVUR and subureteric injection of DHA between January 2005 and December 2015 was performed. Exclusion criteria were diagnosis other than VUR, repeat procedures, and patients with no follow-up. Patient characteristics, postsurgical complications, and follow-up imaging were evaluated. Febrile urinary tract infection (fUTI) was defined as ≥50,000 Colony Forming Units (CFU) of an organism from clean-catch or catheterized urine and temperature ≥ 101.5 F. Clinical success is defined as no fUTI for 1 year after the initial operation. Univariate analyses were used to identify risk factors for treatment failure.

RESULTS

A total of 117 patients met inclusion criteria. Mean age at surgery was 6.0 years, and 85% were female. The mean pre-operative grade of VUR was 3.3 on the EVUR side and 0.6 on the contralateral side (42% resolved before treatment). Median follow-up was 12.2 months (interquartile range, 3.1-25.4). Sixteen patients (14%) had documented fUTI within 1 year, with a clinical success rate of 86%. Of these, five had a postoperative imaging showing resolution of VUR, increasing overall success to 91%. Postoperative fUTI was more common in patients with pre-operative bowel and bladder dysfunction (BBD) (P = 0.003), but this was not associated with a higher reoperation rate (P = 0.168). There were 11 total complications, with three grade 3 complications.

DISCUSSION

This study is the first to report safety and outcomes of EVUR and contralateral DHA injection for patients with high-grade VUR with contralateral low-grade or resolved VUR. It was shown that it is an effective and safe treatment that can be performed as an outpatient therapy. Limitations to this study include the retrospective design and the clinical definition of success that is used in a cohort of patients from across the mountain west region without routine postoperative voiding cystourethrogram.

CONCLUSION

Extravesical ureteral reimplantation and contralateral DHA injection can safely be performed as an outpatient therapy and are effective in the treatment of higher grade VUR with contralateral low-grade or resolved VUR. Treatment failure is more likely in patients with BBD.

Abstract P3-08-03: Defects in BRCA1 Contribute to Global Differential Allele-Specific Expression

Differential allele-specific expression (DASE) has been shown to contribute to phenotypic variability in humans and more recently to the pathogenesis of cancer. DASE is associated with X-chromosome inactivation and genomic imprinting and is relatively common among non-imprinted autosomal genes. The DASE phenotype can also be transmitted by Mendelian inheritance. We have previously reported that nonsense-mediated mRNA decay (NMD) of mutant BRCA1 as well as other epigenetic mechanisms can lead to DASE of BRCA1 and enhanced susceptibility to breast cancer. BRCA1 has been implicated in many cellular processes including DNA repair, cell-cycle-checkpoint control, protein ubiquitination, and chromatin remodeling. Importantly, cells carrying a deleterious BRCA1 mutation exhibit increased genome instability, therefore, we hypothesize that defects in BRCA1 lead not only to DASE of itself, but increase genome-wide DASE and thus contribute to increased breast cancer susceptibility. To test this hypothesis, we employed a genome-wide ASE assay (Illumina Human Omni1-Quad BeadChip) using primary mammary epithelial cells [3 BRCA1 wild-type vs. 3 BRCA1 mutant carrying (2800delAA, 4154delA and R1751X)]. As shown in Table 1, cells carrying a BRCA1 mutation had significantly more DASE events as compared to wild-type cell (P<10-7). In addition, we identified 351 genes demonstrating DASE that were unique to the BRCA1 mutant cells. The cellular functions of these genes are wideranging, including DNA repair, cell cycle control, lipid metabolism and protein degradation. In summary, this study provides the first evidence that mutant BRCA1 can lead to global DASE, which in turn may contribute to the development of breast cancer in mutation carriers. This work was supported in part by the Eileen Stein-Jacoby Fund and a grant from the Congressionally Directed Medical Research Programs, Department of Defense, W81XWH-08-1-0361 (XC).

Table 1. BRCA1 mutations increase the global DASE in PMECs

t; A DASE event is defined as that the Log-ratio of allele-specific expression level of one gene is more than 1 or less than -1, i.e. the expression level from one allele is at least 50% less than the level of another allele

Rapid prototyping raw models on the basis of high resolution computed tomography lung data for respiratory flow dynamics

RATIONALE AND OBJECTIVES

Three-dimensional image reconstruction by volume rendering and rapid prototyping has made it possible to visualize anatomic structures in three dimensions for interventional planning and academic research.

METHODS

Volumetric chest computed tomography was performed on a healthy volunteer. Computed tomographic images of the larger bronchial branches were segmented by an extended three-dimensional region-growing algorithm, converted into a stereolithography file, and used for computer-aided design on a laser sintering machine. The injection of gases for respiratory flow modeling and measurements using magnetic resonance imaging were done on a hollow cast.

RESULTS

Manufacturing the rapid prototype took about 40 minutes and included the airway tree from trackea to segmental bronchi (fifth generation). The branching of the airways are clearly visible in the (3)He images, and the radial imaging has the potential to elucidate the airway dimensions.

CONCLUSION

The results for flow patterns in the human bronchial tree using the rapid-prototype model with hyperpolarized helium-3 magnetic resonance imaging show the value of this model for flow phantom studies.

Lactobacillus Septic Arthritis

Lactobacillus is a Gram positive bacteria found in the mouth, gastrointestinal and female genital tract. Serious infections due to Lactobacillus are becoming increasingly common. We present a 49-year-old diabetic patient with Lactobacillus septic arthritis. To our knowledge, this is the first reported case. Usually, Lactobacillus is implicated with bacteremia, endocarditis and more rarely pneumonia, meningitis and endovascular infection, and half of the cases are reported in immunocompromised patients. As in our patient, diabetes mellitus is a comorbid condition which has been clearly noted. Our finding suggests that further studies are necessary to establish the significance of Lactobacillus as an etiologic agent of septic arthritis.

La séquestration splénique aiguë : une complication rare et grave des syndromes drépanocytaires majeurs de l'adulte. À propos d'un cas

INTRODUCTION

Acute splenic sequestration, a well-recognized complication of sickle cell syndromes, is characterized by a sudden decrease in haemoglobin concentration and marked painless splenomegaly. We report a case illustrating the outcome and the treatment options of this complication.

CASE REPORT

A 45-year old homozygous woman developed acute splenic sequestration with severe anemia. Red blood cells transfusion led to transient improvement but a relapse-required splenectomy. Long-term outcome was favorable.

CONCLUSION

Acute splenic sequestration is a severe complication mainly observed in children. Despite the severity of this complication, prompt diagnosis and appropriate therapy, and particularly red blood cells transfusions, led to a complete recovery. Splenectomy is required in the more severe form of the disease.

[Recurrent Kikuchi's disease in a patient with discoid lupus]

INTRODUCTION

Histiocytic necrotizing lymphadenitis, also called Kikuchi-Fujimoto's disease (KD), usually occurs in young women and is characterized by localized lymphadenitis (mostly cervical) usually associated with fever. Diagnosis relies on histopathological and immunohistochemical analysis of involved lymph node. KD is considered to be the clinical expression of an inadequate immunological reaction, resulting in a self-limited hyperstimulation of the lymphoid tissue, trigerred by an antigenic infectious stimulation. The clinical course is usually benign with a spontaneous remission of symptoms. Recurrence is very rarely observed. KD may be associated with systemic lupus erythematosus, whereas the association with chronic discoid lupus has only been rarely reported.

EXEGESIS

We report a case of KD recurrence, 9 years after the initial diagnosis, in a young eurasian woman, with a chronic discoid lupus erythematosus.

CONCLUSION

KD is a benign disease with a spontaneously good outcome. Recurrence may rarely occur many years after the initial diagnosis but needs a new histopathological confirmation. Systemic or even cutaneous lupus erythematosus may be associated with KD. Although unfrequent, this association suggests that both diseases could share a common pathogenesis.

[Cerebral-vein thrombosis: retrospective study of twenty seven cases]

PURPOSE

Among the locations of venous thrombosis, even if rare, cerebral-vein thrombosis is a severe event with a high mortality rate. No aetiology is found in 20 to 30% of the cases. In recent years, inherited coagulation disorders have been described, as risk factors for venous thrombosis. We report the results of a retrospective study of 27 patients who suffered cerebral-vein thrombosis, in which coagulation abnormalities have been searched for.

METHOD

The patients were referred to the haemostasis laboratory of the Henri Mondor hospital between august 1982 and June 1988, after a cerebral-vein thrombosis. The predisposing factors, personal and family history of thromboembolism, clinical presentation, thrombosis location, evolution under treatment and long-term outcome, have been noted. Deficiencies in antithrombine, protein C, protein S, the Factor V Leiden and the G20210A prothrombin-gene mutation, the presence of lupus anticoagulant, of anticardiolipin antibodies as well as a hyperhomocysteinaemia have been searched, either at the initial presentation, or a posteriori.

RESULTS

Fourty-one percent of patients had a coagulation abnormality. The prevalence of the different abnormalities was: inherited deficiency in AT 7.4%, in PC 8%, in PS 12.5%, factor V Leiden mutation 12%, G20210A prothrombin-gene mutation 12%. Two patients had combined defects: AT and PC deficiency in one, F V Leiden and F II G20210A mutations in one. e of the patient had lupus anticoagulant. Three patients had a significant rate of anticardiolipin antibodies. Five patients out of eight displayed a moderate hyperhomocysteinaemia. Nothing (past history, age, predisposing factors) distinguished those patients bearing a coagulation disorder from the others. The venous thromboembolic relapse rate of 15 % (4/27 patients). Three of them had an inherited thrombophilic abnormality.

CONCLUSION

We recommend an investigation of the haemostasis after every cerebral venous thrombosis.

[Characteristics of autoimmune hemolytic anemia in adults: retrospective analysis of 83 cases]

PURPOSE

To describe the main characteristics and outcome of adult's acquired immune hemolytic anemias (AIHA). To analyse the relevance of the complementary tests performed for the search of an underlying disease.

METHODS

Retrospective (1980-2000) monocentric study.

INCLUSION CRITERIA

age above 16, AIHA defined by an hemoglobin level below 12 g/dl in men and 11 g/dl in women, with hemolysis and/or a positive direct Coombs test and/or the presence of cold agglutinins (threshold 1/500) and/or in the absence of any other cause.

RESULTS

Eighty three patients included (56 women and 27 men), with a mean age of 56 years (+/- 22) at AIHA onset including: 72 patients (87%) with warm antibody AIHA and 11 (13%) with cold agglutinin disease. The mean follow-up was 48 months (median 22 months). Among the 72 patients with warm antibody AIHA, the specificity of autoantibodies was: IgG + complement (43%), IgG (32%) or complement alone (25%); cold agglutinins (titre from 1/60 to 1/512) were detected in 15 (20%) of the patients. Antinuclear antibodies were detected (threshold: 1/80) in 33% of the cases. Hypogammaglobulinemia on serum protein electrophoresis (SPE) was significantively associated with the presence of an underlying non-Hogkin lymphoma (NHL). The CT-scan of the the chest and abdomen which was performed in 50% of the patients, showed abnormalities other than a spleen enlargement in 25% of the cases. The medullar biopsy (MB) was abnormal in 7 of 26 cases (27%) but lead by itself to the diagnosis of NHL in a single case. Thrirty seven (51%) of warm antibody AIHA cases were finally considered to be "secondary" to an underlying disease namely: NHLs (n = 14), Hogkin's disease (n = 1) connective tissue disease (CTD) (n = 14), drug-induced AIHA (n = 3), miscellaneous (n = 5). In 6 out of 14 cases (43%) of NHL's associated AIHA, the onset of AIHA precedes the NHL from 22 to 66 months. The response rates to different therapeutic regimens did not significatively differ when "secondary" and "idiopathic" AIHA were compared. Overall, 13 patients (15.6%) died mainly from infectious complications (n = 5) or an underlying NHL (n = 5).

CONCLUSIONS

In more than half of the cases AIHA are associated with an underlying disease and AIHA may precede the onset of a NHL for a long period. In the absence of a clinically apparent underlying disorder, testing for the presence of antinuclear antibodies, a SPE and a CT-scan must be systematic. Conversely, if no abnormalities are found, the relevance of a systematic MB at AIHA onset seems very low.

[Sickle cell disease in adults: which emergency care by the internists?]

INTRODUCTION

Sickle cell disease is an inherited disease characterized by the presence of an abnormal haemoglobin. It is the most prevalent genetic disease at birth in the Ile-de-France area. Internists are involved in the management of acute complications, particularly acute vaso-occlusive crisis.

CURRENT KNOWLEDGE AND KEY POINTS

Sickle cell disease can be complicated by acute vaso-occlusive crisis, chronic visceral involvement related to the ischaemic process, and infectious complications. In adults, acute vaso-occlusive crisis is the major clinical problem prompting admission to the hospital and the main cause of death. It mainly manifests by osteoarticular pain but other clinical complications can be observed such as acute chest syndrome, priapism, ischaemic or haemorrhagic stroke, abdominal pain and acute multivisceral failure. The treatment of acute vaso-occlusive crisis is symptomatic. Simple transfusion or partial exchange transfusion is required in the more severe form of vaso-occlusive crisis.

FUTURE PROSPECTS AND PROJECTS

The management of adult patients with sickle cell disease must be based on a multidisciplinary approach. At the present time, more than 50% of patients survive beyond the fifth decade. This better and longer life in developed countries has resulted from basic investigations and symptomatic treatments.

Urinary tract infection in adults: research priorities and strategies

Waning interest in urinary tract infection (UTI) research has limited clinical advances during the past two decades. Although care has improved for some specific UTI syndromes, there is limited evidence for most of the decisions made each day in the management of these infections. Additional clinical research is necessary to improve UTI prevention and care strategies.

[Hemolytic anemia disclosing Wilson's disease. Report of 2 cases]

INTRODUCTION

The liver and central nervous system are the usual targets of Wilson's disease, an inherited disorder of copper metabolism. Severe hemolytic anemia is an unusual complication of Wilson's disease.

EXEGESIS

We report two cases of Wilson's disease revealed by acute intravascular hemolytic anemia associated with liver failure. Blood smear analysis showed stippled red cells in one case; hemolytic anemia improved within a few weeks in both patients but progressive liver failure required transplantation in the other. Hemolysis probably results from the toxic effect of free serum copper on erythrocyte membrane.

CONCLUSION

Diagnosis of Wilson's disease must be considered in case of acute hemolytic anemia associated with liver failure in young adults.

The ratio of campesterol to sitosterol that modulates growth in Arabidopsis is controlled by STEROL METHYLTRANSFERASE 2;1

The Arabidopsis genome contains three distinct genes encoding sterol-C24-methyltransferases (SMTs) involved in sterol biosynthesis. The expression of one of them, STEROL METHYLTRANSFERASE 2;1, was modulated in 35S:SMT2;1 Arabidopsis in order to study its physiological function. Plants overexpressing the transgene accumulate sitosterol, a 24-ethylsterol which is thought to be the typical plant membrane reinforcer, at the expense of campesterol. These plants displayed a reduced stature and growth that could be restored by brassinosteroid treatment. Plants showing co-suppression of SMT2;1 were characterized by a predominant 24-methylsterol biosynthetic pathway leading to a high campesterol content and a depletion in sitosterol. Pleiotropic effects on development such as reduced growth, increased branching, and low fertility of high-campesterol plants were not modified by exogenous brassinosteroids, indicating specific sterol requirements to promote normal development. Thus SMT2;1 has a crucial role in balancing the ratio of campesterol to sitosterol in order to fit both growth requirements and membrane integrity.

Glycosides and phenylpropanoid glycerol in vitis vinifera cv. Gewurztraminer wine

Eight glycosides and a phenylpropanoid glycerol were isolated from Vitis vinifera cv. Gewurztraminer wine, and their structures were elucidated by MS and NMR spectroscopies. cis-1-(5-Ethenyl-5-methyltetrahydrofuran-2-yl)-1-methylethyl O-beta-D-apiofuranosyl-(1-->6)-O-beta-D-glucopyranoside, (E)-3,6, 9-trihydroxymegastigm-7-ene 9-O-beta-D-glucopyranoside, 2-phenylethyl O-beta-D-apiofuranosyl-(1-->6)-O-beta-D-glucopyranoside, and 2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]propane-1,3-diol are reported for the first time as wine components.

Breast tumor contamination of peripheral blood stem cell harvests: increased sensitivity of detection using immunomagnetic enrichment

Contaminating tumor cells in peripheral blood stem cell (PBSC) grafts infused for hematopoietic rescue after high-dose chemotherapy could potentially contribute to relapse in BrCa patients. To date the prevalence of PBSC contamination in BrCa patients, as determined by standard immuno-cytochemistry (ICC) assays, has generally been found to be relatively low. However, assay sensitivity may have an important impact on the ability to detect contamination. In this investigation a novel and highly sensitive BrCa cell assay using immunomagnetic enrichment with a panel of antiBrCa monoclonal antibodies (MAbs) and detection by ICC has been characterized. The immunomagnetic enrichment with ICC detection (IE-ICC) assay was directly compared with standard ICC in ability to detect BrCa contamination of PBSC specimens from patients with high-risk stage II/III and metastatic disease. The sensitivity of the IE-ICC assay was approximately 50-fold greater than that of standard ICC. As determined by standard ICC assay, BrCa cells were present in 1/14 patients (7%) and 2/26 (8%) specimens. In contrast, with IE-ICC assay the proportions of positive findings in patients (12/14, 86%) and specimens (19/26, 73%) were significantly higher (p = 0.001 and p < 0.0005, respectively). These preliminary findings suggest that the prevalence of PBSC contamination may be substantially higher than previously appreciated. Consequently, measures to reduce tumor contamination in the graft may have the potential to improve patient outcomes. Higher sensitivity assays such as the IE-ICC assay may play an important role in assessing the risks associated with tumor contamination and the effectiveness of tumor-purging approaches such as positive selection of CD34+ cells and in monitoring patient response to therapy.

Unusual case of diagnosis of pigeon breeder's hypersensitivity pneumonitis with ventilation-perfusion lung scan

The authors describe a patient thought to have pulmonary embolism. Results of a perfusion scan were normal, but Tc-99m DTPA aerosol ventilation lung scan showed, in successive views, decreased activity of the deposited aerosol. The lung Tc-99m DTPA clearance was measured and was markedly increased. This suggested possible hypersensitivity pneumonitis, which was later confirmed as pigeon breeder's disease. The decreased activity observed on the DTPA ventilation scan must be directed toward increased lung clearance and its measurement.

Plant sterol-C24-methyl transferases: different profiles of tobacco transformed with SMT1 or SMT2

Higher plant cells contain a mixture of 24-desmethyl, 24-methyl(ene), and 24-ethyl(idene) sterols in given proportions according to species but also to cell type. As a first step to investigate the function of such sterol compositions in the physiology of a plant, we have illustrated in the present work the coexistence of two distinct (S)-adenosyl-L-methionine sterol-C24-methyltransferases (SMT) in transgenic Nicotiana tabacum L. Indeed, modulation of the expression of the tobacco gene SMT1-1, which encodes a cycloartenol-C24-methyltransferase, results in variations of the proportion of cycloartenol and a concomitant effect on the proportion of 24-ethyl sterols. Overexpression in tobacco of the Arabidopsis thaliana (L.) Heynh. gene SMT2-1 which encodes a 24-methylene lophenol-C24(1)-methyltransferase, results in a dramatic modification of the ratio of 24-methyl cholesterol to sitosterol associated with a reduced growth, a topic discussed in the present work.

Intravenous immunoglobulin for adults with autoimmune thrombocytopenic purpura: results of a randomized trial comparing 0.5 and 1 g/kg b.w

Since the first reports demonstrating the ability of a total dose of 2 g/kg body weight (b.w.) of intravenous immunoglobulin (IVIg) to increase the platelet count in patients with autoimmune thrombocytopenic purpura (AITP), the optimal dose has remained controversial. We report the results of a randomized study which compared two low doses of IVIg (0.5 g/kg b.w., group A, n = 19, and 1 g/kg b.w., group B, n = 18) in 37 adults with AITP and platelet count <50 x 109/l, in preparation for surgery or in a situation with a risk of bleeding. On day 4 the proportion of responses, defined by a platelet count > 80 x 109/l and at least twice the initial platelet count, was significantly higher in the group receiving 1 g/kg b.w. (12/18 in group B versus 4/19 in group A, P = 0.005). All but one of the day 4 responders had already responded on day 3. The daily changes in the platelet count from the beginning of IVIg treatment were larger in group B, with a significant difference relative to group A on day 3 (92 x 109/l in group B versus 50 x 109/l in group A, P = 0.03) and on day 4 (106 x 109/l in group B versus 55 x 109/l in group A, P = 0.03). Patients who had not responded by day 4 subsequently received 1.5 g IVIg/kg b.w. (group A) or 1 g IVIg/kg b.w. (group B). A response was observed in 11/13 initial non-responders in group A, and in 2/6 initial non-responders in group B. Finally, on day 8, the proportion of responders was 78% (29/37) in the entire group and was similar in the two subgroups. In conclusion, (1) initial treatment with 1 g/kg b.w. of IVIg appeared to be more effective than 0.5 g/kg b.w. in adults with AITP; (2) infusion of a low dose of IVIg did not jeopardize the efficacy of IVIg reinfusion; (3) some adults who did not respond to 1 g IVIg/kg b.w. responded to a higher dose.

Costs and benefits of measures to prevent needlestick injuries in a university hospital

OBJECTIVE

To document the costs and the benefits (both in terms of costs averted and of injuries averted) of education sessions and replacement of phlebotomy devices to ensure that needle recapping did not take place.

DESIGN

The percentage of recapped needles and the rate of needlestick injuries were evaluated in 1990 and 1997, from a survey of transparent rigid containers in the wards and at the bedside and from a prospective register of all injuries in the workplace. Costs were computed from the viewpoint of the hospital. Positive costs were those of education and purchase of safer phlebotomy devices; negative costs were the prophylactic treatments and follow-up averted by the reduction in injuries.

SETTING

A 1,050-bed tertiary-care university hospital in the Paris region.

RESULTS

Between the two periods, the proportion of needles seen in the containers that had been recapped was reduced from 10% to 2%. In 1990, 127 needlestick (12.7/100,000 needles) and 52 recapping injuries were reported versus 62 (6.4/100,000 needles) and 22 in 1996 and 1997. When the rates were related to the actual number of patients, the reduction was 76 injuries per year. The total cost of information and preventive measures was $325,927 per year. The cost-effectiveness was $4,000 per injury prevented.

CONCLUSION

Although preventive measures taken to ensure reduction of needlestick injuries appear to have been effective (75% reduction in recapping and 50% reduction in injuries), the cost of the safety program was high.

The response to high-dose intravenous immunoglobulin or steroids is not predictive of outcome after splenectomy in adults with autoimmune thrombocytopenic purpura

The response to high-dose intravenous immunoglobulin (IVIg) was recently reported to be predictive of outcome after splenectomy in patients with autoimmune thrombocytopenic purpura (AITP). We analysed the records of 75 adults with chronic AITP who received IVIg and subsequently underwent splenectomy. There was no significant difference in the response rate to splenectomy according to whether or not patients had responded to IVIg (81% v 67%, P = 0.36). Age, the time from diagnosis to splenectomy, and the response to steroids were also not significantly associated with outcome after splenectomy. These results indicate that the response to IVIg or steroids is not predictive of the efficacy of splenectomy.

Prostatitis unplugged? Prostatic massage revisited

Repetitive prostatic massage is not a new tool in the urologists' armatarium. Once the most popular therapeutic maneuver used to treat prostatitis, it was abandoned as primary therapy almost 3 decades ago. Based on experience reported outside North America and anecdotal experiences of some patients and their physicians, it may be making a comeback. Unfortunately, there are almost no prospective data that would substantiate a claim as to its effectiveness. This article discusses the historic aspects of prostatic massage, suggests possible mechanisms of action, and describes the opinions of North American urologists who are associated with academic clinical research centers and are universally acknowledged as experts in the diagnosis and treatment of prostatitis. At this time, the science of prostatic massage must rely on anecdotal experiences, small, uncontrolled studies, and perhaps somewhat biased opinions of the major thought leaders in the field of chronic prostatitis/chronic pelvic pain syndrome.

Zidovudine-induced mitochondrial disorder with massive liver steatosis, myopathy, lactic acidosis, and mitochondrial DNA depletion

Zidovudine is known to be responsible for a mitochondrial myopathy with ragged-red fibres and mitochondrial DNA depletion in muscle. Lactic acidosis alone or associated with hepatic abnormalities has also been reported. A single report mentioned the concomitant occurrence of muscular and hepatic disturbances and lactic acidosis in a patient receiving zidovudine, but muscle and liver tissues were not studied. A 57-year-old man with AIDS, who had been treated with zidovudine for 3 years, developed fatigue and weight loss. Serum creatine kinase and hepatic enzyme levels were high. Lactic acidosis was present. Liver biopsy showed diffuse macrovacuolar and microvacuolar steatosis. After withdrawal of zidovudine, creatine kinase, aspartate aminotransferase, and alanine aminotransferase levels normalised within 5 days, and lactacidaemia decreased. Acidosis persisted. The patient became confused and febrile and died 8 days after detection of high blood lactic acid. A muscle sample obtained at autopsy showed mitochondrial abnormalities with ragged-red fibres and lipid droplet accumulation. Southern blot analysis showed depletion of mitochondrial DNA, affecting skeletal muscle and liver tissue. No depletion was found in myocardium and kidney. This case emphasises that zidovudine treatment can induce mitochondrial multisystem disease, as revealed in our case by myopathy, liver steatosis and lactic acidosis.

[Hemolysis and schizocytosis, malabsorption and the "folate trap": unusual semiological peculiarities associated with vitamin B12 deficiency]

INTRODUCTION

Hemolysis and red cell fragmentation accompanying vitamin B12 deficiency may misdirect the diagnosis. Signs of malabsorption and abnormalities related to folic acid metabolism characterized by discrepancies between folic acid normal serum levels and erythrocytic folic acid levels may also exist.

EXEGESIS

We report the occurrence of hemolysis and red cell fragmentation mimicking microangiopathic hemolytic anemia, malabsorption and folic acid deficiency in the course of vitamin B12 deficiency. Appropriate replacement therapy corrected all abnormalities.

CONCLUSION

An association between hemolysis, malabsorption and folic acid deficiency should lead physicians to search for signs of vitamin B12 deficiency.

Pulmonary embolism; lung scanning interpretation: about words

OBJECTIVE

To assess clinicians' agreement on how they interpret lung scan reports with regard to the diagnosis of pulmonary embolism.

DESIGN

In this prospective study, nuclear medicine physicians provided two types of reports for each lung scan: a routine descriptive report and a short form with a standardized conclusion on the likelihood of pulmonary embolism: "high probability," "no conclusion," and "diagnosis excluded." Three independent blinded senior clinicians reviewed all routine reports and chose one of the following conclusions: "high probability," "no conclusion," or "diagnosis excluded."

SETTING

An acute care teaching hospital near Paris.

SUBJECTS

Eighty-two lung scans were studied.

MAIN OUTCOME MEASUREMENTS

Inter-clinician agreement and agreement between clinicians' conclusions and the nuclear medicine physicians' standardized reports were analyzed using the kappa index.

RESULTS

The distribution of the clinicians' conclusions from routine reports strongly differed (p < 0.001). Agreement among the three clinicians was observed in 40.2% of the routine reports, and the inter-clinician agreement was poor to moderate (kappa range, 0.28 to 0.52). A complete agreement among the three clinicians and the nuclear medicine physicians' standardized conclusions was observed for 32.9% of the reports. The agreement between each clinician and the standardized conclusions was also poor to moderate (kappa range, 0.32 to 0.55).

CONCLUSION

Reading the same routine reports, clinicians reached different conclusions. Furthermore these differed greatly from the nuclear medicine physicians' standardized conclusions. These results support the notion that physicians should be given standardized reports.

Acquired hemophilia due to factor VIII inhibitors in 34 patients

BACKGROUND

Acquired hemophilia is a rare disease caused by the development of auto-antibodies against factor VIII.

SUBJECTS AND METHODS

We studied the characteristics and outcomes of 34 patients (19 women and 15 men) with acquired hemophilia from 1980 to 1997.

RESULTS

The mean age of the patients was 61 years (range, 22-93 years). An underlying disease was observed in 18 (53%) patients: 5 patients had cancer, 4 an autoimmune disorder, 2 a dermatologic disorder, 3 asthma, 3 were postpartum, and 1 had an adverse reaction to ampicillin. Factor VIII level was <5% in 30 (90%) patients; factor VIII antibodies were elevated (>10 Bethesda units) in 23 (69%) patients. Bleeding requiring transfusions was reported in 25 (75%) patients. Human factor VIII was given to 14 patients and porcine factor VIII to 5. Six patients received prothrombin complex concentrates and one desmopressin. Several immunosuppressive treatments were used, mainly corticosteroids, cyclophosphamide, and intravenous immunoglobulin. Bleeding stopped in all but one patient within 2 weeks. Most patients achieved complete remission, although two relapses were observed subsequently.

CONCLUSION

This large study helps to clarify the presentation and clinical course of acquired hemophilia. Prospective studies are needed to determine the efficacy of treatment.

Neutrophil precursor generation: effects of culture conditions

The influence of feeding schedules on the expansion and differentiation of enriched PB CD34+ cells (84.9+/-14.7% purity) was studied after 12-13 days of serum-free liquid culture. CD34+ cell cultures were initiated (n=6) on day 0 (2 x 10(5) cells) in X-VIVO 10 medium containing 1% human albumin (HA) and 100 ng/ml each of rIL-3, rIL-6, rSCF, and rG-CSF. The cultures were supplemented on days 3, 6, and 9 as follows: condition 1, unfed (static culture); condition 2, 100 ng/ml rG-CSF; condition 3, split 1:2 medium + 100 ng/ml each rIL-3, rIL-6, rSCF, and rG-CSF; condition 4, split 1:2 medium + 100 ng/ml rG-CSF. The proliferative capacities (fold increase) of condition 2 (49.1+/-21.3), condition 3 (75.6+/-33.4), and condition 4 (63.1+/-23.8) cultures were significantly higher (p < 0.05) than that of the condition 1 unfed (35.5+/-14.0) cultures. Flow cytometric analysis (CD15-FITC/CD11b-PE) showed that the highest CD15+ cell purity (neutrophil precursors) was found in the condition 3 (1.18 x 10(7)+/-4.29 x 10(6)) cultures, followed by condition 4 (9.84 x 10(6)+/-3.57 x 10(6)), condition 2 (7.54 x 10(6)+/-2.06 x 10(6)), and condition 1 (4.78 x 10(6)+/-9.80 x 10(5)), respectively. The average cloning efficiency of the day 0 enriched CD34+ cells, 15.1%+/-10.3%, decreased to less than 0.2% in all of the day 12-13 cultures. These data suggest that feeding CD34+ cell cultures with rG-CSF alone, medium + rG-CSF, or medium + rIL3, rIL-6, rSCF, and rG-CSF enhances CD15+ neutrophil precursor (promyelocytes, myelocytes, metamyelocytes) production in vitro.