The Lysosomal Calcium Channel TRPML1 Maintains Mitochondrial Fitness in NK Cells through Interorganelle Cross-Talk

Cytotoxic lymphocytes eliminate cancer cells through the release of lytic granules, a specialized form of secretory lysosomes. This compartment is part of the pleomorphic endolysosomal system and is distinguished by its highly dynamic Ca2+ signaling machinery. Several transient receptor potential (TRP) calcium channels play essential roles in endolysosomal Ca2+ signaling and ensure the proper function of these organelles. In this study, we examined the role of TRPML1 (TRP cation channel, mucolipin subfamily, member 1) in regulating the homeostasis of secretory lysosomes and their cross-talk with mitochondria in human NK cells. We found that genetic deletion of TRPML1, which localizes to lysosomes in NK cells, led to mitochondrial fragmentation with evidence of collapsed mitochondrial cristae. Consequently, TRPML1-/- NK92 (NK92ML1-/-) displayed loss of mitochondrial membrane potential, increased reactive oxygen species stress, reduced ATP production, and compromised respiratory capacity. Using sensitive organelle-specific probes, we observed that mitochondria in NK92ML1-/- cells exhibited evidence of Ca2+ overload. Moreover, pharmacological activation of the TRPML1 channel in primary NK cells resulted in upregulation of LC3-II, whereas genetic deletion impeded autophagic flux and increased accumulation of dysfunctional mitochondria. Thus, TRPML1 impacts autophagy and clearance of damaged mitochondria. Taken together, these results suggest that an intimate interorganelle communication in NK cells is orchestrated by the lysosomal Ca2+ channel TRPML1.

Allelic variation of KIR and HLA tunes the cytolytic payload and determines functional hierarchy of NK cell repertoires

The functionality of natural killer (NK) cells is tuned during education and is associated with remodeling of the lysosomal compartment. We hypothesized that genetic variation in killer cell immunoglobulin-like receptor (KIR) and HLA, which is known to influence the functional strength of NK cells, fine-tunes the payload of effector molecules stored in secretory lysosomes. To address this possibility, we performed a high-resolution analysis of KIR and HLA class I genes in 365 blood donors and linked genotypes to granzyme B loading and functional phenotypes. We found that granzyme B levels varied across individuals but were stable over time in each individual and genetically determined by allelic variation in HLA class I genes. A broad mapping of surface receptors and lysosomal effector molecules revealed that DNAM-1 and granzyme B levels served as robust metric of the functional state in NK cells. Variation in granzyme B levels at rest was tightly linked to the lytic hit and downstream killing of major histocompatibility complex-deficient target cells. Together, these data provide insights into how variation in genetically hardwired receptor pairs tunes the releasable granzyme B pool in NK cells, resulting in predictable hierarchies in global NK cell function.

TRP Channels as Interior Designers: Remodeling the Endolysosomal Compartment in Natural Killer Cells

Cytotoxic lymphocytes, including natural killer (NK) cells and T cells are distinguished by their ability to eliminate target cells through release of secretory lysosomes. Conventional lysosomes and secretory lysosomes are part of the pleomorphic endolysosomal system and characterized by its highly dynamic nature. Several calcium-permeable TRP calcium channels play an essential role in endolysosomal calcium signaling to ensure proper function of these organelles. In NK cells, the expression of self MHC-specific inhibitory receptors dynamically tunes their secretory potential in a non-transcriptional, calcium-dependent manner. New insights suggest that TRPML1-mediated lysosomal calcium fluxes are tightly interconnected to NK cell functionality through modulation of granzyme B and perforin content of the secretory lysosome. Lysosomal TRP channels show a subset-specific expression pattern during NK differentiation, which is paralleled with gradually increased loading of effector molecules in secretory lysosomes. Methodological advances, including organellar patch-clamping, specific pharmacological modulators, and genetically-encoded calcium indicators open up new possibilities to investigate how TRP channels influence communication between intracellular organelles in immune cells. This review discusses our current understanding of lysosome biogenesis in NK cells with an emphasis on the TRP mucolipin family and the implications for NK cell functionality and cancer immunotherapy.

Remodeling of secretory lysosomes during education tunes functional potential in NK cells

Inhibitory signaling during natural killer (NK) cell education translates into increased responsiveness to activation; however, the intracellular mechanism for functional tuning by inhibitory receptors remains unclear. Secretory lysosomes are part of the acidic lysosomal compartment that mediates intracellular signalling in several cell types. Here we show that educated NK cells expressing self-MHC specific inhibitory killer cell immunoglobulin-like receptors (KIR) accumulate granzyme B in dense-core secretory lysosomes that converge close to the centrosome. This discrete morphological phenotype is independent of transcriptional programs that regulate effector function, metabolism and lysosomal biogenesis. Meanwhile, interference of signaling from acidic Ca²⁺ stores in primary NK cells reduces target-specific Ca²⁺-flux, degranulation and cytokine production. Furthermore, inhibition of PI(3,5)P₂ synthesis, or genetic silencing of the PI(3,5)P₂-regulated lysosomal Ca²⁺-channel TRPML1, leads to increased granzyme B and enhanced functional potential, thereby mimicking the educated state. These results indicate an intrinsic role for lysosomal remodeling in NK cell education.

Induction of the BIM Short Splice Variant Sensitizes Proliferating NK Cells to IL-15 Withdrawal

Adoptive transfer of allogeneic NK cells holds great promise for cancer immunotherapy. There is a variety of protocols to expand NK cells in vitro, most of which are based on stimulation with cytokines alone or in combination with feeder cells. Although IL-15 is essential for NK cell homeostasis in vivo, it is commonly used at supraphysiological levels to induce NK cell proliferation in vitro. As a result, adoptive transfer of such IL-15-addicted NK cells is associated with cellular stress because of sudden cytokine withdrawal. In this article, we describe a dose-dependent addiction to IL-15 during in vitro expansion of human NK cells, leading to caspase-3 activation and profound cell death upon IL-15 withdrawal. NK cell addiction to IL-15 was tightly linked to the BCL-2/BIM ratio, which rapidly dropped during IL-15 withdrawal. Furthermore, we observed a proliferation-dependent induction of BIM short, a highly proapoptotic splice variant of BIM in IL-15-activated NK cells. These findings shed new light on the molecular mechanisms involved in NK cell apoptosis following cytokine withdrawal and may guide future NK cell priming strategies in a cell therapy setting.

The 7th French Airborne Forward Surgical Team experience of surgical support to the population of a low-income country: a prospective study on 341 patients with short-term follow-up

BACKGROUND

The 7th Airborne Forward Surgical Team (FST) has deployed to Chad in 2015 and 2016, in support of French military forces. Humanitarian surgical care is known to represent a significant part of the surgical activity in such missions, but to date limited data have been published on the subject.

METHODS

All surgical patients from a civilian host population treated by the FST during these missions have been prospectively included. Indications, operative outcomes and postoperative outcomes were evaluated.

RESULTS

During this period, the FST operated on 358 patients. Humanitarian surgical care represented 95% of the activity. Most patients (92.7%) were operated for elective surgery. Emergencies and infectious diseases represented, respectively, 7.3% and 9.1% of cases. The mean length of stay (LOS) was three days (2-4), and the median follow-up was 30 days (22-34). Mortality rate was 0.6% and morbidity was 5.6%. Parietal surgery had no significant complication and had shorter LOS (p<0.001). Emergent surgeries were more complicated (p<0.01) and required more reoperations (p<0.05). Surgical infectious cases had longer LOS (p<0.01).

CONCLUSIONS

Humanitarian surgical care can be provided without compromising the primary mission of the medical forces. Close surveillance and follow-up allowed favourable outcomes with low morbidity and mortality rates. Humanitarian care is responsible for a considerable portion of the workload in such deployed surgical teams. Accounting for humanitarian care is essential in the planning and training for such future medical operations.

Investigating the influence of intraindividual changes in perceived stress symptoms on injury risk in soccer

Research has shown that high levels of stress and stress responsivity can increase the risk of injuries. However, most of the research that has supported this notion has focused on between-person relationships, ignoring the relationships at the within-person level. As a result, the objective of this study was to investigate if within-person changes in perceived stress symptoms over a 1-month time period could predict injury rates during the subsequent 3 months. A prospective design with two measurement points (Time 1-at the beginning of the season and Time 2-1 month into the season) was utilized. A total of 121 competitive soccer players (85 males and 36 females; M_age  = 18.39, SD = 3.08) from Sweden and the United States completed the Kessler Psychological Distress Scale (KPDS) and a demographic sheet at Time 1. The KPDS was also completed at Time 2, and all acute injuries that occurred during the subsequent 3-month period were recorded. A Bayesian latent change scores model was used to determine whether within-person changes in stress symptoms could predict the risk of injury. Results revealed that there was a credible positive effect of changes in stress symptoms on injury rates, indicating that an increase in reported stress symptoms was related to an increased risk for injury. This finding highlights the importance of creating caring and supportive sporting environments and relationships and teaching stress management techniques, especially during the earlier portion of competitive seasons, to possibly reduce the occurrence of injuries.

CD56bright NK cells exhibit potent antitumor responses following IL-15 priming

NK cells, lymphocytes of the innate immune system, are important for defense against infectious pathogens and cancer. Classically, the CD56dim NK cell subset is thought to mediate antitumor responses, whereas the CD56bright subset is involved in immunomodulation. Here, we challenge this paradigm by demonstrating that brief priming with IL-15 markedly enhanced the antitumor response of CD56bright NK cells. Priming improved multiple CD56bright cell functions: degranulation, cytotoxicity, and cytokine production. Primed CD56bright cells from leukemia patients demonstrated enhanced responses to autologous blasts in vitro, and primed CD56bright cells controlled leukemia cells in vivo in a murine xenograft model. Primed CD56bright cells from multiple myeloma (MM) patients displayed superior responses to autologous myeloma targets, and furthermore, CD56bright NK cells from MM patients primed with the IL-15 receptor agonist ALT-803 in vivo displayed enhanced ex vivo functional responses to MM targets. Effector mechanisms contributing to IL-15-based priming included improved cytotoxic protein expression, target cell conjugation, and LFA-1-, CD2-, and NKG2D-dependent activation of NK cells. Finally, IL-15 robustly stimulated the PI3K/Akt/mTOR and MEK/ERK pathways in CD56bright compared with CD56dim NK cells, and blockade of these pathways attenuated antitumor responses. These findings identify CD56bright NK cells as potent antitumor effectors that warrant further investigation as a cancer immunotherapy.

Medical management of patients with peripheral arterial disease

Peripheral arterial disease (PAD) is one of the most frequent manifestations of atherosclerosis and is associated with atherosclerosis in the coronary and carotid arteries, leading to a highly increased incidence of cardiovascular events. Major risk factors of PAD are similar to those that lead to atherosclerosis in other vascular beds. However, there are differences in the power of individual risk factors in the different vascular territories. Cigarette smoking and diabetes mellitus represent the greatest risks of PAD. For prevention of the progression of PAD and accompanying cardiovascular events similar preventative measures are used as in coronary artery disease (CAD). However, recent data indicate that there are some differences in the efficacy of drugs used in the prevention of atherothrombotic events in PAD. Antiplatelet treatment is indicated in virtually all patients with PAD. In spite of the absence of hard evidence- based data on the long term efficacy of aspirin, it is still considered as a first line treatment and clopidogrel as an effective alternative. The new antiplatelet drugs ticagrelol and prasugrel also represent promising options for treatment of PAD. Statin therapy is indicated to achieve the target low density lipoprotein cholesterol level of ≤2.5 mmol/L (100 mg/dL) and there is emerging evidence that lower levels are more effective. Statins may also improve walking capacity. Antihypertensive treatment is indicated to achieve the goal blood pressure (<140/90 mmHg). All classes of antihypertensive drugs including beta-blockers are acceptable for treatment of hypertension in patients with PAD. Diabetic patients with PAD should reduce their glycosylated haemoglobin to ≤7%. As PAD patients represent the group with the highest risk of atherothrombotic events, these patients need the most intensive treatment and elimination of risk factors of atherosclerosis. These measures should be as comprehensive as those in patients with established coronary and cerebrovascular disease.

Results of the randomized, placebo-controlled clopidogrel and acetylsalicylic acid in bypass surgery for peripheral arterial disease (CASPAR) trial

OBJECTIVE

Dual antiplatelet therapy with clopidogrel plus acetylsalicylic acid (ASA) is superior to ASA alone in patients with acute coronary syndromes and in those undergoing percutaneous coronary intervention. We sought to determine whether clopidogrel plus ASA conferred benefit on limb outcomes over ASA alone in patients undergoing below-knee bypass grafting.

METHODS

Patients undergoing unilateral, below-knee bypass graft for atherosclerotic peripheral arterial disease (PAD) were enrolled 2 to 4 days after surgery and were randomly assigned to clopidogrel 75 mg/day plus ASA 75 to 100 mg/day or placebo plus ASA 75 to 100 mg/day for 6 to 24 months. The primary efficacy endpoint was a composite of index-graft occlusion or revascularization, above-ankle amputation of the affected limb, or death. The primary safety endpoint was severe bleeding (Global Utilization of Streptokinase and Tissue plasminogen activator for Occluded coronary arteries [GUSTO] classification).

RESULTS

In the overall population, the primary endpoint occurred in 149 of 425 patients in the clopidogrel group vs 151 of 426 patients in the placebo (plus ASA) group (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.78-1.23). In a prespecified subgroup analysis, the primary endpoint was significantly reduced by clopidogrel in prosthetic graft patients (HR, 0.65; 95% CI, 0.45-0.95; P = .025) but not in venous graft patients (HR, 1.25; 95% CI, 0.94-1.67, not significant [NS]). A significant statistical interaction between treatment effect and graft type was observed (P(interaction) = .008). Although total bleeds were more frequent with clopidogrel, there was no significant difference between the rates of severe bleeding in the clopidogrel and placebo (plus ASA) groups (2.1% vs 1.2%).

CONCLUSION

The combination of clopidogrel plus ASA did not improve limb or systemic outcomes in the overall population of PAD patients requiring below-knee bypass grafting. Subgroup analysis suggests that clopidogrel plus ASA confers benefit in patients receiving prosthetic grafts without significantly increasing major bleeding risk.

Anterior cervical fusion with a bio-resorbable composite cage (beta TCP-PLLA): clinical and radiological results from a prospective study on 20 patients

A resorbable composite material (40% PLLA and 60% beta TCP) with a high breaking strength and capacity to withstand plastic and elastic strain has been developed for cervical interbody fusion. This is a prospective study to evaluate clinical and radiological results of 20 patients implanted with 27 cages (mean follow-up, 27 months). Clinical (neck disability index, VAS, neurological evaluation) and radiological (anteroposterior, lateral, bending X-rays) data were assessed before and after surgery. At the end of the study, CT scan was performed to evaluate fusion, resorption of the cage and density of the new tissue substituting the cage. The mean patient age was 50.3 years (range, 18-79 years). The average improvement was 55% for neck pain, 83% for arm pain and 65% for NDI, with 85% good or excellent results at final outcomes. Radiologically, lordosis was significantly improved (mean gain of 5.4 degrees and 3.7 degrees for overall and segmental lordosis, respectively). This correction was conserved in 95% of cases. Fusion was obtained in 96% (CT evaluation). Resorption was started in all cases and completed in an average of 36 months after surgery. The mean density of tissue substituting the cage was 659 UH with a range, of 455-911 UH (compatible with bone nature). Over time, the amount of bony tissue increased and the graft remodelled with an increase in density value. This demonstrates a biological activity and changing bone mineral content of this tissue. The new composite cage under investigation provides long-term fusion without loss of correction or inflammatory reaction. The ceramic block guarantees the maintenance of the disc height and its slow resorption allows long-term fusion and stability with good and reliable clinical and radiological outcomes.

Sentinel lymph nodes in endometrial cancer: is hysteroscopic injection valid?

We aimed to describe hysteroscopic peritumoral tracer injection for detecting sentinel lymph nodes (SLNs) in patients with endometrial cancer and to evaluate tolerance of the procedure, detection rate and location of SLNs. Five patients with early endometrial cancer underwent hysteroscopic radiotracer injection followed by lymphoscintigraphy, then by surgery with hysteroscopic peritumoral blue dye injection, and radioactivity measurement using an endoscopic handheld gamma probe. SLNs and other nodes were sent separately to the pathology laboratory. SLNs were evaluated by hematoxylin-eosin-saffron staining and, when negative, by immunohistochemistry. Tolerance of the injection by the patients was poor (mean visual analog scale score, 8/10). SLNs were detected in only two patients (external iliac and common iliac+paraaortic, respectively). Detection rates were 1/5 by radiotracer, 1/5 by dye, and 2/5 by the combined method. One SLN was involved in a patient whose other nodes were negative. In three patients no SLNs were found by radiotracer or blue dye. Of the 83 non sentinel nodes removed from these patients, none was involved. Hysteroscopic peritumoral injection may be more difficult than cervical injection and, in our experience, carries a lower SLN detection rate.

Population based epidemiology of ankle sprains attending accident and emergency units in the West Midlands of England, and a survey of UK practice for severe ankle sprains

OBJECTIVES

To estimate the incidence of ankle sprains and severe ankle sprains attending accident and emergency (A&E) units; to describe current practice for severe ankle sprains in A&E units in the United Kingdom.

METHODS

Crude age and sex specific incidence rates were calculated for four health districts from cases ascertained from data on seven A&E clinical information systems. Case records of patients with ankle sprains at an A&E unit in another health district were audited and the proportion of severe ankle sprains calculated. UK A&E units were surveyed about their usual treatment of patients with severe ankle sprains.

RESULTS

The estimate of the crude incidence rate of ankle sprains was a minimum of 52.7 per 10 000, rising to 60.9 (95% CI 59.4 to 62.4) when figures were adjusted for the proportion of patients without a diagnostic code (13.7%). There were important age-sex differences with unadjusted rates observed from 127.8 per 10 000 (CI 115.5 to 140.0) in girls aged 10-14 years to 8.2 (CI 4.2 to 12.3) in men aged 70-74 years. As 14% of ankle sprains attending A&E were classed as severe, this would equate to 42 000 severe ankle sprains per year in the UK. In the UK wide survey, there was a response rate of 79% (211 of 266). Among the responders, Tubigrip was used routinely in 55%, below knee casts in 3%, and braces in 2%. Boots were not used routinely in any unit.

CONCLUSION

While there is considerable variation in severe ankle sprain management in UK A&E units, most are treated with the minimal mechanical support of Tubigrip.

A new cacao linkage map based on codominant markers: development and integration of 201 new microsatellite markers

A linkage map of cacao based on codominant markers has been constructed by integrating 201 new simple sequence repeats (SSR) developed in this study with a number of isoenzymes, restriction fragment length polymorphisms (RFLP), microsatellite markers and resistance and defence gene analogs (Rgenes-RFLP) previously mapped in cacao. A genomic library enriched for (GA)(n) and (CA)(n) was constructed, and 201 new microsatellite loci were mapped on 135 individuals from the same mapping population used to establish the first reference maps. This progeny resulted from a cross between two heterozygous cacao clones: an Upper-Amazon Forastero (UPA 402) and a Trinitario (UF 676). The new map contains 465 markers (268 SSRs, 176 RFLPs, five isoenzymes and 16 Rgenes-RFLP) arranged in ten linkage groups corresponding to the haploid chromosome number of cacao. Its length is 782.8 cM, with an average interval distance between markers of 1.7 cM. The new microsatellite markers were distributed throughout all linkage groups of the map, but their distribution was not random. The length of the map established with only SSRs was 769.6 cM, representing 94.8% of the total map. The current level of genome coverage is approximately one microsatellite every 3 cM. This new reference map provides a set of useful markers that is transferable across different mapping populations and will allow the identification and comparison of the most important regions involved in the variation of the traits of interest and the development of marker-assisted selection strategies.

Mapping QTL for yield components, vigor, and resistance to Phytophthora palmivora in Theobroma cacao L

Quantitative trait loci (QTL) mapping for agronomic traits was carried out in cocoa (Theobroma cacao L.). Regions of the genome involved in yield, vigor, and resistance to Phytophthora palmivora were identified. Three heterozygous clones, one upper Amazon Forastero (IMC78) and two Trinitario (DR1 and S52), were crossed with the same male parent, a lower Amazon Forastero (Catongo), known to be highly homozygous. Observations were made on progeny over nine consecutive years. One to three QTL related to yield were detected in each of the three populations, located on chromosomes 1, 2, 4, 5, 9, and 10. They explained between 8.1 and 19.3% of the phenotypic variation and showed various levels of repeatability. In IMC78, the QTL detected on chromosome 5 was the most repeatable over years. The QTL for the average individual pod weight on chromosome 4 was the most significant with an LOD of 17.3 and an R2 of 43.7. QTL related to these traits were identified in the same region of the genome in clones of different genetic groups. This suggests that molecular markers can be used to improve cocoa varieties.

Mapping quantitative trait loci for bean traits and ovule number in Theobroma cacao L

Quantitative trait loci (QTL) mapping for bean traits and the number of ovules per ovary was carried out in cocoa (Theobroma cacao L.) using three test-cross progenies derived from crosses between a lower Amazon Forastero male parent (Catongo) and three female parents: one upper Amazon Forastero (IMC78) and two Trinitario (DR1 and S52). RFLP (restriction fragment length polymorphism), microsatellite, and AFLP (amplified fragment lengthpolymorphism) markers were used for mapping. Between one and six QTL for bean traits (length, weight, and shape index) and one and four QTL for the number of ovules per ovary were detected using composite interval mapping (CIM). Individual QTL explained between 5 and 24% of the phenotypic variation. QTL clusters were identified on several chromosomes, but particularly on chromosome 4. QTL related to bean traits were detected in the same region in both Trinitario parents and in a close region in the upper Amazon Forastero parent. In reference to a previous diversity study where alleles specific to Criollo and Forastero genotypes were identified, it was possible to speculate on the putative origin (Criollo or Forastero) of favorable QTL alleles segregating in both Trinitario studied.

Mapping QTL for yield components, vigor, and resistance to Phytophthora palmivora in Theobroma cacao L

Quantitative trait loci (QTL) mapping for agronomic traits was carried out in cocoa (Theobroma cacao L.). Regions of the genome involved in yield, vigor, and resistance to Phytophthora palmivora were identified. Three heterozygous clones, one upper Amazon Forastero (IMC78) and two Trinitario (DR1 and S52), were crossed with the same male parent, a lower Amazon Forastero (Catongo), known to be highly homozygous. Observations were made on progeny over nine consecutive years. One to three QTL related to yield were detected in each of the three populations, located on chromosomes 1, 2, 4, 5, 9, and 10. They explained between 8.1 and 19.3% of the phenotypic variation and showed various levels of repeatability. In IMC78, the QTL detected on chromosome 5 was the most repeatable over years. The QTL for the average individual pod weight on chromosome 4 was the most significant with an LOD of 17.3 and an R2 of 43.7. QTL related to these traits were identified in the same region of the genome in clones of different genetic groups. This suggests that molecular markers can be used to improve cocoa varieties.

Mapping quantitative trait loci for bean traits and ovule number in Theobroma cacao L

Quantitative trait loci (QTL) mapping for bean traits and the number of ovules per ovary was carried out in cocoa (Theobroma cacao L.) using three test-cross progenies derived from crosses between a lower Amazon Forastero male parent (Catongo) and three female parents: one upper Amazon Forastero (IMC78) and two Trinitario (DR1 and S52). RFLP (restriction fragment length polymorphism), microsatellite, and AFLP (amplified fragment lengthpolymorphism) markers were used for mapping. Between one and six QTL for bean traits (length, weight, and shape index) and one and four QTL for the number of ovules per ovary were detected using composite interval mapping (CIM). Individual QTL explained between 5 and 24% of the phenotypic variation. QTL clusters were identified on several chromosomes, but particularly on chromosome 4. QTL related to bean traits were detected in the same region in both Trinitario parents and in a close region in the upper Amazon Forastero parent. In reference to a previous diversity study where alleles specific to Criollo and Forastero genotypes were identified, it was possible to speculate on the putative origin (Criollo or Forastero) of favorable QTL alleles segregating in both Trinitario studied.

[Tibial valgus osteotomy using a tricalcium phosphate medial wedge: a minimally invasive technique]

PURPOSE OF THE STUDY

We present a minimally invasive technique for tibial valgus osteotomy using a medial wedge composed of tricalcium phosphate.

MATERIAL AND METHODS

The bone substitute is composed of slowly resorbable tricalcium phosphate material shaped to the desired form and having mechanical properties allowing stable osteotomy via a short incision and staple fixation. Intraoperative fluoroscopy enables a reliable and reproducible technique. A lateral fixation staple is required because there is a risk the lateral hinge could break. This technique was used for 58 knees in 55 patients (mean age 47 years). According to the Ahlback classification of femorotibial degeneration, there were 43 grade I knees, 12 grade II, and 3 grade III.

RESULTS

The implant was well tolerated in all cases. Bone healing was achieved in most cases without loss of the osteotomy angle. Complications were: rupture of the lateral hinge in four cases leading to nonunion in one, one low-grade infection. Implant resorption at mid term was significant: among the 22 patients with a follow-up of more than 5 years, the implant was barely visible in 18.

DISCUSSION

This technique provides an easy way to achieve tibial valgus osteotomy without compromising future intervention. The technique can be considered to be minimally invasive because of the size of the incision, the minimal fixation required, and the bone sparing effect of the bone substitute.

Extensive deep vein thrombosis in a young woman. Case report

We report a case of a young lady with an extensive deep vein thrombosis (DVT) diagnosed by CT scan and duplex ultrasound examination. Contributory factors were relative immobilisation, oral contraception and hyperhomocysteinemia after methionine loading. No other thrombophilic factors could be found. The three main causes of hyperhomocysteinemia are genetic defects, nutritional deficiencies and insufficient elimination. In our case a genetic defect for one of the key enzymes of homocysteine metabolism, may be the underlying cause. Besides stopping oral contraceptive drugs, anticoagulation and supplementation with pyridoxine and folate was started. Family screening was carried out and revealed other members with hyperhomocysteinemia. Whether therapy with pyridoxine and folate can substantially reduce the recurrence of venous thromboembolic disease remains to be established.

Prevalence of potential candidates for biventricular pacing among patients with known coronary artery disease: a prospective registry from a single center

New forms of ventricular pacing are increasingly studied as an option in the management of patients with heart failure. Coronary artery disease (CAD) is the most frequent cause of heart failure, and patients with complete left or right bundle branch block (LBBB and RBBB) and a reduced left ventricular ejection fraction (LVEF) are the best candidates for this new therapy. However, the prevalence of this clinical presentation is uncertain. During a 1-year period, 433 patients with documented CAD (mean age 64 +/- 10 years, 79% men) who were referred for myocardial perfusion imaging were prospectively studied. All patients underwent a 2-day stress-rest gated 99mTc-Tetrofosmin SPECT study with evaluation of resting LV enddiastolic (LVEDV) and endsystolic (LVESV) volumes and LVEF. The resting ECG was examined in all patients for the presence of complete LBBB or RBBB. Of the 433 patients with CAD 36 patients (8.3%) had LBBB (n = 14) or RBBB (n = 22) and a QRS width > 120 ms. These 36 patients were in general older and more frequently had diabetes and atrial fibrillation. Patients with LBBB or RBBB had a significantly lower LVEF (41 +/- 16% vs 48 +/- 14%, P < 0.01) and significantly higher LV volumes compared to patients without LBBB or RBBB (177 +/- 79 mL vs 131 +/- 53 mL, P < 0.001 for LVEDV and 116 +/- 76 mL vs 73 +/- 49 mL, P < 0.001 for LVESV). In total, 112/433 (26%) had an LVEF < or = 40%; 16 had also a LBBB or RBBB (3.7% of the whole population, 14% of the patients with a LVEF < or = 40%). Within the group of patients with a LVEF > or = 40%, patients with BBB had comparable LVEF (26 +/- 9% vs 30 +/- 8%, P = NS) but significantly higher LVEDV and LVESV (230 +/- 70 mL vs 190 +/- 64 mL, P < 0.05 for LVEDV and 170 +/- 65 mL vs 135 +/- 56 mL, P < 0.05 for LVESV). In this prospective registry 3.7% of all patients with known CAD had LBBB or RBBB in combination with a LVEF < or = 40%. This represented 14% of all patients with a LVEF > or = 40%. These limited numbers should be kept in mind when considering biventricular pacing as a new therapeutic options in patients with heart failure.

Response to antihypertensive therapy in older patients with sustained and nonsustained systolic hypertension. Systolic Hypertension in Europe (Syst-Eur) Trial Investigators

BACKGROUND

The goal of the present study was to assess the effect of antihypertensive therapy on clinic (CBP) and ambulatory (ABP) blood pressures, on ECG voltages, and on the incidence of stroke and cardiovascular events in older patients with sustained and nonsustained systolic hypertension.

METHODS AND RESULTS

Patients who were >/=60 years old, with systolic CBP of 160 to 219 mm Hg and diastolic CBP of <95 mm Hg, were randomized into the double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) Trial. Treatment consisted of nitrendipine, with the possible addition of enalapril, hydrochlorothiazide, or both. Patients enrolled in the Ambulatory Blood Pressure Monitoring Side Project were classified according to daytime systolic ABP into 1 of 3 subgroups: nonsustained hypertension (<140 mm Hg), mild sustained hypertension (140 to 159 mm Hg), and moderate sustained hypertension (>/=160 mm Hg). At baseline, patients with nonsustained hypertension had smaller ECG voltages (P<0.001) and, during follow-up, a lower incidence of stroke (P<0.05) and of cardiovascular complications (P=0.01) than other groups. Active treatment reduced ABP and CBP in patients with sustained hypertension but only CBP in patients with nonsustained hypertension (P<0.001). The influence of active treatment on ECG voltages (P<0.05) and on the incidence of stroke (P<0.05) and cardiovascular events (P=0.06) was more favorable than that of placebo only in patients with moderate sustained hypertension.

CONCLUSIONS

Patients with sustained hypertension had higher ECG voltages and rates of cardiovascular complications than did patients with nonsustained hypertension. The favorable effects of active treatment on these outcomes were only statistically significant in patients with moderate sustained hypertension.

The efficacy of Farabloc, an electromagnetic shield, in attenuating delayed-onset muscle soreness

OBJECTIVE

To assess the hypothesis that Farabloc, a fabric with electromagnetic shielding properties, would attenuate the symptoms, signs, and muscular strength deficit secondary to delayed-onset muscle soreness (DOMS) induced by two exposures to eccentric exercise in humans.

DESIGN

Randomized, single-blind, placebo-controlled, crossover trial with two testing stages of 5 days duration separated by a washout period of more than 8 weeks.

SETTING

University-based sports medicine center.

PARTICIPANTS

Twenty volunteers equally representing untrained male and female subjects.

INTERVENTIONS

20 sets of 10 repetitions of single-leg eccentric knee extensions for 37 minutes with the Biodex dynamometer set at 30 degrees per second were performed on the first day of stage one and stage two to induce DOMS in the quadriceps muscle. Double layers of fabric, either Farabloc or placebo, were wrapped around the thigh of each participant during each stage for 5 days.

MAIN OUTCOME MEASURES

Perception of muscle pain, as measured by a visual analog scale (VAS), and strength, as measured by knee extensor torque (EST) with the Biodex dynamometer, were evaluated at 0, 24, 48, 72, and 96 hours. Serum inflammatory markers of muscle damage, including malondialdehyde. creatine phosphokinase, myoglobin, leukocytes, and neutrophils, were assayed at 0, 2, 6, 24, and 48 hours.

RESULTS

Repeated-measures analysis of variance was carried out for each of the seven variables to assess differences for fabric, order of treatment, time, and all combinations. Results of VAS and EST and levels of malondialdehyde, creatine phosphokinase, myoglobin, leukocytes, and neutrophils all showed a highly significant effect of Farabloc compared with placebo. This analysis shows that the order of Farabloc or placebo fabric use in stage I and 2 produces different results. This may be caused by a learning effect, but did not alter the overall influence of Farabloc.

CONCLUSION

The data indicate that double layers of Farabloc fabric wrapped around the thigh reduces pain and strength loss and serum levels of malondialdehyde, creatine phosphokinase, myoglobin, leukocytes, and neutrophils when untrained human subjects are exposed to eccentric exercise to produce DOMS in the quadriceps. Farabloc shields high-frequency electromagnetic fields, although the results do not indicate how these changes are mediated. Further research is needed to determine the mechanism.

Blood Pressure Monitoring. Task force III: Target-organ damage, morbidity and mortality

OBJECTIVE

To reach a consensus on ambulatory blood pressure (ABP) as a predictor of target-organ damage (TOD), morbidity and mortality.

METHOD

The members of task force III wrote this article in preparation for the Seventh International Consensus Conference (23-25 September 1999). This article was amended after the meeting to reflect the consensus reached at the conference.

POINTS OF CONSENSUS

In most studies, TOD in essential hypertension was more closely associated with ABP than it was with clinic blood pressure, the mean weighted correlation coefficients for the relationship of left ventricular mass with blood pressure being 0.50/0.44 (24h systolic/diastolic blood pressure) and 0.35/0.32 (clinic systolic/diastolic blood pressure), respectively. The above correlation coefficients vary among studies, possibly because of different standardizations of clinic blood pressure measurements and ways of selecting subjects, among other reasons. The closeness of the association between clinic blood pressure and left ventricular mass increases with the numbers of clinic measurements of blood pressure and visits to a clinic. Thus, the variance of left ventricular mass explained by ABP in addition to that explained by clinic blood pressure diminishes with the number of clinic blood pressure readings. The proportion of variability of left ventricular mass that is directly accounted for by the day-night difference in blood pressure is 15% at the most. Thus, the advantage of ABP over clinic blood pressure appears to be, at least in part, a result of the greater number of measurements over the 24h. It might also depend, however, on the information offered by ambulatory blood pressure monitoring (ABPM) on daily-life variations in blood pressure. TOD appears to be more closely associated with ABP than it is with clinic blood pressure for the subjects with reproducible ABP tracings, but not for those with poorly reproducible tracings. The probability of developing sustained clinic hypertension at follow-up seems to be better predicted by clinic blood pressure on several occasions over a 6-month period than it is by ABP at baseline, although, when also ABPM is repeatedly performed at follow-up, its ability to predict clinical outcomes of hypertensive patients remains superior to that of repeated clinic blood pressure measurements. ABPM of the elderly appears feasible and is tolerated well. A blunted day-night fall in blood pressure ('non-dipping') seems to be harmful, while evidence regarding the potentially harmful effect of extreme dipping is still limited. Authors of the Syst-Eur study recently demonstrated the prognostic value of ambulatory systolic blood pressure and in particular, of night-time blood pressure, in assessing old subjects with isolated systolic hypertension. The assessment of variability of blood pressure has been shown to provide a further prediction of cardiovascular risk and the potentially prognostic value of beat-to-beat variability assessed non-invasively (using a Finapres or Portapres device)needs further study. In the published event-based studies, the prognostic value of ABP recorded during a single session was superior to that of clinic blood pressure. Since the authors of published event-based prognostic studies compared ABP with only a few clinic measurements of blood pressure, it is not known how many visits or measurements of blood pressure (and at what cost) would equate to a single session of ABPM in terms of prediction of cardiovascular events. ABPM might allow one to identify a subset with 'normal' ABP (white-coat or isolated clinic hypertension). Daytime ABP levels <135 mmHg systolic and 85 mmHg diastolic can be defined as normal and values <130/80 mmHg could be defined as optimal. Cardiovascular risk for subjects with normal ABP seems to be lower than that for those with abnormally high ABP. Long-term observational and intervention studies concerning subjects with white-coat hypertension are needed. (ABST

Predicting cardiovascular risk using conventional vs ambulatory blood pressure in older patients with systolic hypertension. Systolic Hypertension in Europe Trial Investigators

CONTEXT

The clinical use of ambulatory blood pressure (BP) monitoring requires further validation in prospective outcome studies.

OBJECTIVE

To compare the prognostic significance of conventional and ambulatory BP measurement in older patients with isolated systolic hypertension.

DESIGN

Substudy to the double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) Trial, started in October 1988 with follow up to February 1999. The conventional BP at randomization was the mean of 6 readings (2 measurements in the sitting position at 3 visits 1 month apart). The baseline ambulatory BP was recorded with a noninvasive intermittent technique.

SETTING

Family practices and outpatient clinics at primary and secondary referral hospitals.

PARTICIPANTS

A total of 808 older (aged > or =60 years) patients whose untreated BP level on conventional measurement at baseline was 160 to 219 mm Hg systolic and less than 95 mm Hg diastolic.

INTERVENTIONS

For the overall study, patients were randomized to nitrendipine (n = 415; 10-40 mg/d) with the possible addition of enalapril (5-20 mg/d) and/or hydrochlorothiazide (12.5-25.0 mg/d) or to matching placebos (n = 393).

MAIN OUTCOME MEASURES

Total and cardiovascular mortality, all cardiovascular end points, fatal and nonfatal stroke, and fatal and nonfatal cardiac end points.

RESULTS

After adjusting for sex, age, previous cardiovascular complications, smoking, and residence in western Europe, a 10-mm Hg higher conventional systolic BP at randomization was not associated with a worse prognosis, whereas in the placebo group, a 10-mm Hg higher 24-hour BP was associated with an increased relative hazard rate (HR) of most outcome measures (eg, HR, 1.23 [95% confidence interval [CI], 1.00-1.50] for total mortality and 1.34 [95% CI, 1.03-1.75] for cardiovascular mortality). In the placebo group, the nighttime systolic BP (12 AM-6 AM) more accurately predicted end points than the daytime level. Cardiovascular risk increased with a higher night-to-day ratio of systolic BP independent of the 24-hour BP (10% increase in night-to-day ratio; HR for all cardiovascular end points, 1.41; 95% CI, 1.03-1.94). At randomization, the cardiovascular risk conferred by a conventional systolic BP of 160 mm Hg was similar to that associated with a 24-hour daytime or nighttime systolic BP of 142 mm Hg (95% CI, 128-156 mm Hg), 145 mm Hg (95% CI, 126-164 mm Hg) or 132 mm Hg (95% CI, 120-145 mm Hg), respectively. In the active treatment group, systolic BP at randomization did not significantly predict cardiovascular risk, regardless of the technique of BP measurement.

CONCLUSIONS

In untreated older patients with isolated systolic hypertension, ambulatory systolic BP was a significant predictor of cardiovascular risk over and above conventional BP.

Haptoglobin polymorphism and peripheral arterial occlusive disease

Haptoglobin (Hp) 2-2 phenotype is a genetic risk factor in coronary atherosclerosis. In this study, haptoglobin phenotypes were determined in 141 patients with peripheral arterial occlusive disease (PAOD) and compared to a reference population (n = 1000). The relative Hp1 allele frequency was decreased among PAOD patients (0.294 vs. 0.403 for the reference population, P < 0.01) due to an overrepresentation of the Hp 2-2 phenotype (50%, odds ratio 1.82 (95% C.I. 1.28-2.60), P < 0.001). This finding was even more pronounced in non-diabetic and in non-smoking PAOD patients (Hp1 allele frequencies: 0.265 and 0.228, respectively). Serum lipids, inflammatory parameters, and blood pressure levels were comparable among the Hp phenotypes, but serum levels of the antioxidant vitamin C were lower in Hp 2-2 patients than in patients with another phenotype (P < 0.05). In PAOD patients with severe atherosclerotic lesions, maximal walking distance of patients carrying a Hp 2-2 phenotype (225-525 m) exceeded that of other Hp phenotypes (50-242 m) (interquartile ranges) (P < 0.05). The findings demonstrate that, despite an increased risk for developing PAOD, the Hp 2-2 phenotype is associated with a longer maximal walking distance which might be attributed to the earlier reported in vitro angiogenic properties of the Hp 2-2 molecule.

Prolonged antihypertensive effect of amlodipine: a prospective double-blind randomized study

Amlodipine is a calcium antagonist with a long elimination half-life (35 to 50 h) allowing a once daily dosing in the treatment of hypertension. This randomized, double-blind study was performed to assess the residual antihypertensive effect of amlodipine 5 mg O.D. 3 days after discontinuing therapy in previously well-controlled mild to moderate hypertensive patients. Blood pressure (BP) was evaluated by conventional (OBP) and by ambulatory blood pressure monitoring (ABPM). Amlodipine 5 mg OD administered during a 6-week period, significantly reduced both OBP and ABPM mean values (p < 0.05), whereas no change in heart rate was observed. At the end of the active treatment period, adequately controlled patients were randomized either to amlodipine 5 mg OD (group A) or amlodipine for 12 days followed by a 3-day period on placebo. After this double-blind treatment phase, group P exhibited no significant increase in BP (assessed by OBP or ABPM) when compared to group A. In conclusion, the duration of action of amlodipine extends largely beyond the 24-h span, and when patients omit their treatment for 3 days BP does not significantly increase.

Popliteal artery entrapment syndrome

Popliteal artery entrapment syndrome (PAES) is a rare cause of exercise-induced leg pain. Entrapment occurs because of an abnormal relationship between the popliteal artery and the surrounding myofascial structures in the popliteal fossa. Arterial insufficiency in the affected limb arises with entrapment of the artery, commonly giving leg symptoms with exertion. The true incidence of PAES in the general population is not known. The aetiology of PAES has an embryological basis related to the development of the popliteal artery and the surrounding musculature. Many different classification schemes have been developed to differentiate the various types of abnormal anatomy that are associated with the syndrome. Repeated popliteal artery compression causes trauma to the arterial wall, leading to premature localised atherosclerosis. The pathology of PAES is believed to be progressive, with arterial thrombosis occurring in some individuals as a natural progression of the disease process. Acute ischaemia can occur if there is an occlusion of the artery or thrombosis within an aneurysm. Clinically, up to 85% of individuals diagnosed with the syndrome are males. The mean age of individuals in a large series was 28 years. The condition can be found bilaterally in 25% of cases. Most individuals present with exercise-induced leg pain, the remainder presenting with acute or chronic ischaemia. The condition can result in significant functional loss for active individuals. Surgery has been advocated to prevent the progression of the disease that is believed to be the natural history of untreated PAES. However, the little research that has been done to determine the prognosis for individuals who have undergone surgery has focused on the patency rate of the arteries after surgery and the presence or absence of complications. Research needs to be done to look at the natural history of untreated PAES and the functional status of athletes after undergoing PAES surgery.

Chronic venous disorders of the leg: epidemiology, outcomes, diagnosis and management. Summary of an evidence-based report of the VEINES task force. Venous Insufficiency Epidemiologic and Economic Studies

BACKGROUND

To critically review the classification, epidemiology, outcomes, diagnosis and treatment of chronic venous disorders of the leg (CVDL), to issue evidence-based recommendations, and to identify areas requiring further research.

METHODS

Articles identified by an extensive literature search were scored by members of an international task force. Only those articles with a moderate or strong rating for internal validity were retained.

RESULTS

A scoring system weighing CVDL severity according to the probability of ulcer occurrence is proposed. Epidemiological data on the frequency of CVDL and its risk factors are reviewed. The following items are evaluated: costs associated with treatment; clinical outcomes related to CVDL and its treatment; available generic and disease-specific measures of quality of life; diagnostic procedures used to detect venous reflux; and efficacy of available treatments.

CONCLUSIONS

CVDL is an important public health problem, based on its prevalence, cost and impact on quality of life. High-priority areas for research on CVDL are identified.

The Selvester 32-point QRS score for evaluation of myocardial infarct size after primary coronary angioplasty

In patients treated successfully with primary angioplasty for a first myocardial infarction, the Selvester 32-point score correlates well with infarct size measured with quantitative thallium-201 perfusion imaging. Therefore, it is a useful parameter for infarct sizing, particularly in patients with anterior infarction or reduced ejection fraction at discharge.

Ambulatory blood pressure monitoring and postprandial hypotension in elderly patients with isolated systolic hypertension. Systolic Hypertension in Europe (SYST-EUR) Trial Investigators

The present analysis was undertaken to evaluate postprandial (PP) changes in blood pressure (BP) assessed with ambulatory BP monitoring (ABPM) in elderly subjects with isolated systolic hypertension (ISH) on conventional measurement. A total of 530 patients (335 women and 195 men, aged 60-100 years, median 70 years) who performed an ABPM during the placebo run-in period of the Syst-Eur trial were included into the analysis. The PP changes in BP and heart rate (HR) were calculated by subtracting the mean systolic BP (SBP), diastolic BP (DBP) and HR in the 2 h preceding the main meal from the corresponding means covering the 2 h after the meal. The reproducibility of the postprandial fall in BP and heart rate (PPH) was assessed by contrasting the first and second ABPM in a subgroup of 147 patients who performed two ABPM's during the placebo run-in period. The mean SBP and DBP decreased and reached the nadir 2 h after the main meal while HR did not change. When PPH was assessed by comparing BP in the 2 h before and after the meal, both SBP and DBP decreased significantly (respectively -6.6 mm Hg, -5.4 mm Hg; P < 0.001). In 67.6% of all patients a decrease in SBP was observed and in 24.1% it exceeded 16 mm Hg. The corresponding values for DBP were 71.3% and 24.5% (DBP decreased more than 12 mm Hg). A greater fall in DBP was associated with a greater decrease in HR (r = 0.20, P < 0.001), while changes in SBP and HR were not interrelated. Regression analysis did not identify any significant covariate of PPH. Group means of PPH could be reproduced without significant changes in their values, but the within-subject reproducibility of the PP changes was low. There were no differences in PPH according to the place of residence of the patients. In conclusion, the descriptive analysis of the meal-induced changes in ABPM in elderly subjects with ISH showed that in every day circumstances most of them experience falls in both SBP and DBP within 2 h after the meal.