Optical characterization of high performance mirrors based on cavity ringdown time measurements with 6 degrees of freedom mirror positioning

An instrument capable of measuring optical losses, transmission, and the radius of curvature of high reflectivity mirrors is presented. The measurement setup consists of two remote controlled hexapod systems with 6 degrees of freedom placed inside a vacuum enclosure. Mirror loss measurements are performed via the cavity ring-down time method using a linear resonant two-mirror Fabry-Perot cavity configuration. The use of high-precision positioning systems enables cavity loss mapping by transversely scanning the position of the cavity end mirror. Mirror surfaces of up to 30 mm in diameter can be scanned, and the cavity length can be tuned by 120 mm.

Frequency-Dependent Squeezed Vacuum Source for the Advanced Virgo Gravitational-Wave Detector

In this Letter, we present the design and performance of the frequency-dependent squeezed vacuum source that will be used for the broadband quantum noise reduction of the Advanced Virgo Plus gravitational-wave detector in the upcoming observation run. The frequency-dependent squeezed field is generated by a phase rotation of a frequency-independent squeezed state through a 285 m long, high-finesse, near-detuned optical resonator. With about 8.5 dB of generated squeezing, up to 5.6 dB of quantum noise suppression has been measured at high frequency while close to the filter cavity resonance frequency, the intracavity losses limit this value to about 2 dB. Frequency-dependent squeezing is produced with a rotation frequency stability of about 6 Hz rms, which is maintained over the long term. The achieved results fulfill the frequency dependent squeezed vacuum source requirements for Advanced Virgo Plus. With the current squeezing source, considering also the estimated squeezing degradation induced by the interferometer, we expect a reduction of the quantum shot noise and radiation pressure noise of up to 4.5 dB and 2 dB, respectively.

Enhanced dispatch and rendezvous doubles the catchment area and number of patients treated on a mobile stroke unit

INTRODUCTION

Mobile Stroke Units (MSUs) deliver acute stroke treatment on-scene in coordination with Emergency Medical Services (EMS). One criticism of the MSU approach is the limited range of a single MSU. The Houston MSU is evaluating MSU implementation, and we developed a rendezvous approach as an innovative solution to expand the range and number of patients treated.

METHODS

In addition to direct 911 dispatch of our MSU to the scene within our 7-mile catchment area, we empowered more distant EMS units to activate the MSU. We also monitored EMS radio communications to identify possible patients. For these distant patients, the MSU met the EMS unit en route to the stroke center and treated the patient at that intermediate location. The distribution of the distance from MSU base station to site of stroke and time from 911 alert to tissue plasminogen activator (tPA) bolus were compared between patients treated on-scene and by rendezvous using Wilcoxon rank sum test.

RESULTS

Over 4 years, 338 acute ischemic stroke patients were treated with tPA on our MSU. Of these, 169 (50%) were treated on-scene after MSU dispatch at a median of 6.4 miles (IQR 6.4 miles) from MSU base station. 169 (50%) were treated by 'rendezvous' pathway with assessment and treatment of stroke a median of 12.4 miles from base (IQR 5.5 miles) (p< 0.0001). Time (min) from MSU alert to tPA bolus did not differ: 36.0 ± 10.0 for on-scene vs 37.0 ± 10.0 with rendezvous (p=0.65). 13% of patients alerted via direct 911 dispatch were treated vs 44% of rendezvous patients.

CONCLUSION

Adding a rendezvous approach to an MSU dispatch pathway doubles the range of operations and the number of patients treated by an MSU in an urban area, without incurring delay.

Abstract 99: Mobile Stroke Unit CTA and Direct Notification of Interventional Team Shortens Door-to-Puncture Time by One Hour

Introduction: Endovascular thrombectomy (ET) is an effective but time sensitive treatment of acute ischemic stroke. Time from Emergency Department (ED) arrival to start of ET (door-to-puncture time, DTPT) is a modifiable metric. One of the most time consuming steps in prolonging DTPT is identification of large vessel occlusion (LVO) by CT angiography (CTA). BEST-MSU is a prospective multicenter comparative effectiveness study of tPA-eligible patients managed on a mobile stroke unit (MSU) vs Emergency Medical Services (Standard Management, SM). After discovering that DTPT was greater than 60 minutes in both groups at three BEST-MSU centers in 2018, we began to routinely obtain CTA on the MSU and directly alert the ET team at receiving hospitals if a LVO was identified. We hypothesized this would shorten DTPT by over 30 minutes.

Methods: In this single center experience, we compared the median (interquartile range, IQR) DTPT and MSU on-scene time for MSU patients having on-board CTA and then ET from 9/2018 to 7/2019 to corresponding MSU ET patients (excluding any that had on-board CTA) from 8/2014 to 8/2018. All CTAs were completed after tPA bolus and during tPA infusion on a Ceretom 8 slice scanner with OptiStat hand injector. All imaging occurred on-scene with the MSU stationary. Consent was obtained for all patients and strict radiation safety guidelines followed.

Results: 13 consecutive patients having CTA on-board the MSU and then ET were compared to 84 patients in the pre-on-board CTA group. Baseline characteristics including median NIHSS score (20 in both groups) and frequency of tPA (85% on-board CTA vs 89% pre-on-board CTA) were comparable. Median DTPT was 60 minutes shorter with on-board CTA and direct notification of the interventional team from the MSU; 34 minutes (IQR 30-57) vs 94.5 minutes (IQR 69.75-117.25) (p < 0.001). Despite the additional time to obtain the CTA on the MSU, on-scene time was only slightly prolonged and did not offset the reduction in DTPT (on-board CTA 30 minutes (IQR 28-33) vs pre-on-board CTA 27 minutes (IQR 23-31) (p = 0.01).

Conclusion: Pre-hospital identification and notification of LVO by a MSU allows a one hour reduction of DTPT, and can be utilized to establish a direct to angiosuite protocol.

Abstract 32: “Rendezvous System” for Broadening a Mobile Stroke Unit Catchment Area

Purpose: Mobile Stroke Units (MSU) deliver acute stroke treatment on-scene in coordination with Emergency Medical Services (EMS) prior to transport to a stroke center. One criticism is the limited range of a single MSU. The Houston MSU is the only one in the U.S. using a rendezvous system with EMS to expand its range.

Methods: In addition to direct 911 dispatch of our MSU directly to the scene for tPA eligible patients within our “catchment” area (8 miles), we asked more distant EMS units to notify the MSU and also monitored EMS radio communication to identify eligible patients. For these “distant” patients, the MSU meets the EMS unit enroute to the stroke center and treats the patient at that intermediate location (usually a parking lot). The distribution of the distance from MSU base station to site of stroke and time from alert to tPA bolus were compared between patients treated on scene and by rendezvous using Wilcoxon rank sum test.

Results: From August 18, 2014 to July 20, 2018, 290 acute ischemic stroke patients were treated with tPA on our MSU. Of these, 140 (48.3%) were treated on scene by direct 911 dispatch, with a median of 7 miles (IQR 5 miles) from MSU base station. 150 (51.7%) patients were treated by rendezvous. They had their strokes a median of 13 miles from base (IQR 6 miles) (p<0.0001). Time (min) from 911 alert to tPA bolus was 37.6±9.7 with on-scene, and 37.7±12.7 with rendezvous (p=0.89).

Conclusion: A “rendezvous system” significantly expands the range of operations for a MSU in an urban area, doubling the number of patients treated, without incurring delay. This approach might be even more useful in rural areas.

LOX-1 activation by oxLDL triggers an epithelial mesenchymal transition and promotes tumorigenic potential in prostate cancer cells

Obesity is related to an increased risk of developing prostate cancer with high malignancy stages or metastasis. Recent results demonstrated that LOX-1, a receptor associated with obesity and atherosclerosis, is overexpressed in advanced and metastatic prostate cancer. Furthermore, high levels of oxLDL, the main ligand for LOX-1, have been found in patients with advanced prostate cancer. However, the role of LOX-1 in prostate cancer has not been unraveled completely yet. Here, we show that LOX-1 is overexpressed in prostate cancer cells and its activation by oxLDL promotes an epithelial to mesenchymal transition, through of lowered expression of epithelial markers (E-cadherin and plakoglobin) and an increased expression of mesenchymal markers (vimentin, N-cadherin, snail, slug, MMP-2 and MMP-9). Consequently, LOX-1 activation by oxLDL promotes actin cytoskeleton restructuration and MMP-2 and MMP-9 activity inducing prostate cancer cell invasion and migration. Additionally, LOX-1 increased the tumorigenic potential of prostate cancer cells and its expression was necessary for tumor growth in nude mice. In conclusion, our results suggest that oxLDL/LOX-1 could be ones of mechanisms that explain why obese patients with prostate cancer have an accelerated tumor progression and a greater probability of developing metastasis.

Comparative genomics to bridge Vicia faba with model and closely-related legume species: stability of QTLs for flowering and yield-related traits

This study presents the development of an enhanced map in faba bean. The map contains 258 loci, mostly gene-based markers, organized in 16 linkage groups that expand 1,875 cM, with an average inter-marker distance of 7.26 cM. The combination of EST-derived markers with a number of markers physically located or previously ascribed to chromosomes by trisomic segregation, allowed the allocation of eight linkage groups (229 markers), to specific chromosomes. Moreover, this approach provided anchor points to establish a global homology among the faba bean chromosomes and those of closely-related legumes species. The map was used to identify and validate, for the first time, QTLs controlling five flowering and reproductive traits: days to flowering, flowering length, pod length, number of seeds per pod and number of ovules per pod. Twelve QTLs stable in the 2 years of evaluation were identified in chromosomes II, V and VI. Comparative mapping suggested the conservation of one of the faba bean genomic regions controlling the character days to flowering in other five legume species (Medicago, Lotus, pea, lupine, chickpea). Additional syntenic co-localizations of QTLs controlling pod length and number of seeds per pod between faba bean and Lotus japonicus are likely. The new genetic map opens the way for further translational studies between faba bean and related legume species, and provides an efficient tool for breeding applications such as QTL analysis and marker-assisted selection.

Combining fluorescent in situ hybridization data with ISS staging improves risk assessment in myeloma: an International Myeloma Working Group collaborative project

The combination of serum β2-microglobulin and albumin levels has been shown to be highly prognostic in myeloma as the International Staging System (ISS). The aim of this study was to assess the independent contributions of ISS stage and cytogenetic abnormalities in predicting outcomes. A retrospective analysis of international studies looking at both ISS and cytogenetic abnormalities was performed in order to assess the potential role of combining ISS stage and cytogenetics to predict survival. This international effort used the International Myeloma Working Group database of 12 137 patients treated worldwide for myeloma at diagnosis, of whom 2309 had cytogenetic studies and 5387 had analyses by fluorescent in situ hybridization (iFISH). Comprehensive analyses used 2642 patients with sufficient iFISH data available. Using the comprehensive iFISH data, combining both t(4;14) and deletion (17p), along with ISS stage, significantly improved the prognostic assessment in terms of progression-free survival and overall survival. The additional impact of patient age and use of high-dose therapy was also demonstrated. In conclusion, the combination of iFISH data with ISS staging significantly improves risk assessment in myeloma.

International Myeloma Working Group molecular classification of multiple myeloma: spotlight review

Myeloma is a malignant proliferation of monoclonal plasma cells. Although morphologically similar, several subtypes of the disease have been identified at the genetic and molecular level. These genetic subtypes are associated with unique clinicopathological features and dissimilar outcome. At the top hierarchical level, myeloma can be divided into hyperdiploid and non-hyperdiploid subtypes. The latter is mainly composed of cases harboring IgH translocations, generally associated with more aggressive clinical features and shorter survival. The three main IgH translocations in myeloma are the t(11;14)(q13;q32), t(4;14)(p16;q32) and t(14;16)(q32;q23). Trisomies and a more indolent form of the disease characterize hyperdiploid myeloma. A number of genetic progression factors have been identified including deletions of chromosomes 13 and 17 and abnormalities of chromosome 1 (1p deletion and 1q amplification). Other key drivers of cell survival and proliferation have also been identified such as nuclear factor- B-activating mutations and other deregulation factors for the cyclin-dependent pathways regulators. Further understanding of the biological subtypes of the disease has come from the application of novel techniques such as gene expression profiling and array-based comparative genomic hybridization. The combination of data arising from these studies and that previously elucidated through other mechanisms allows for most myeloma cases to be classified under one of several genetic subtypes. This paper proposes a framework for the classification of myeloma subtypes and provides recommendations for genetic testing. This group proposes that genetic testing needs to be incorporated into daily clinical practice and also as an essential component of all ongoing and future clinical trials.

CAPs markers to assist selection for low vicine and convicine contents in faba bean (Vicia faba L.)

The antinutritional factors (ANFs) present in Vicia spp. seeds are a major constraint to the wider utilization of these crops as grain legumes. In the case of faba bean (Vicia faba L.), a breeding priority is the absence vicine and convicine (v-c); responsible for favism in humans and for the reduced animal performance or low egg production in laying hens. The discovery of a spontaneous mutant allele named vc-, which induces a 10-20 fold reduction of v-c contents, may facilitate the process. However, the high cost and difficulty of the chemical detection of v-c seriously restricts the advances in breeding-selection. To identify random amplified polymorphic DNA (RAPD) markers linked to this gene, we have analysed an F(2 )population derived from a cross between a line with high v-c content (Vf6) and the vc- genotype (line 1268). Quantification of v-c was done by spectrophotometry on the parents and the F(2 )population (n = 136). By using bulked segregant analysis (BSA), two RAPD markers linked in coupling and repulsion phase to the allele vc- were identified and further converted into sequence characterized amplified regions (SCARs). Amplification of SCARS was more consistent, although the initial polymorphism between pools was lost. To recover the polymorphisms several approaches were explored. Restriction digestion with HhaI (for SCAR SCH01(620)) and RsaI (for SCAR SCAB12(850)) revealed clear differences between the parental lines. The simultaneous use of the two cleavage amplified polymorphism (CAP) markers will allow the correct fingerprinting of faba bean plants and can be efficiently used in breeding selection to track the introgression of the vc- allele to develop cultivars with low v-c content and improved nutritional value.

Patterns of BCR/ABL gene rearrangements by interphase fluorescence in situ hybridization (FISH) in BCR/ABL+ leukemias: incidence and underlying genetic abnormalities

Interphase fluorescence in situ hybridization (iFISH) is increasingly used for the identification of BCR/ABL gene rearrangements in chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL). In the present study, we have explored the incidence of both typical and atypical iFISH patterns of BCR/ABL gene rearrangements in a series of 168 consecutive BCR/ABL+ patients--135 CML, 31 precursor B-ALL and two acute myeloblastic leukemia (AML) cases--and established their underlying genetic alterations through further molecular and chromosome analyses. Two different FISH probes (Vysis Inc., Downers Grove, IL, USA) were used: the LSI BCR/ABL dual color extra signal (ES) and the dual color dual fusion BCR/ABL probe (D-FISH). Our results show that most BCR/ABL+ patients (83%, including 88% of all CML, 61% of ALL and one of two AML) displayed typical iFISH patterns of either Major (M) BCR/ABL (87% of CML, 13% of ALL and one of the two AML) or minor (m) BCR/ABL gene rearrangements (1% of all CML and 48% of ALL cases) with the two probes. Further molecular and cytogenetic studies confirmed the presence of such typical rearrangements in all except one of these ALL cases who had coexistence of an MBCR/ABL and an mBCR/ABL gene rearrangement together with monosomy 9. In the remaining 29 cases (17%), up to five different atypical iFISH patterns were detected with the ES probe. Atypical iFISH patterns were most frequently due to additional numerical changes--most often supernumerary Philadelphia (Ph) chromosome (7%) but also gain or loss of chromosome 9 (1%) or 22 (1%). Deletion of 9q sequences proximal to the breakpoint were also frequently observed with the ES probe (8%). Application of the D-FISH probe showed that in most of these latter cases (5%) deletion of 22q sequences distal to the breakpoint also occurred. The remaining cases with atypical iFISH had cryptic insertion of BCR in 9q34 (1%). Exact interpretation of each iFISH pattern was supported by FISH on metaphases and molecular determination of the BCR breakpoint. In summary, our results indicate that despite the high incidence of typical iFISH patterns of BCR/ABL gene rearrangements, atypical patterns are also found in BCR/ABL+ acute leukemias; the precise definition of the alteration present in individual cases is dependent on metaphase studies and molecular definition of the breakpoint.

Fraud. What is the evidence?

The home health industry complains that Medicare fraud and abuse initiatives and legislation, namely, Operation Restore Trust (ORT), the Health Insurance Portability and Accountability Act (HIPAA) of 1996, and the Balanced Budget Act (BBA) of 1997 developed when home health care was vulnerable to reimbursement reductions from Medicaid and commercial insurers, particularly Health Maintenance Organizations. Additionally, it contends that the Health Care Financing Administration (HCFA) founded these initiatives on controversial government studies showing high rates of home health fraud and abuse and inappropriate assumptions that rising costs were indicative of fraudulent activities (Sarraille & William, 1998). We summarize reasons why the home health industry became a focus for enhanced Medicare fraud and abuse reduction efforts by HCFA and provide evidence supporting enforcement actions by HCFA's partners.

A new morphologic classification system for acute promyelocytic leukemia distinguishes cases with underlying PLZF/RARA gene rearrangements

Acute promyelocytic leukemia (APL) is typified by the t(15;17) translocation, which leads to the formation of the PML/RARA fusion gene and predicts a beneficial response to retinoids. However, approximately 10% of all APL cases lack the classic t(15;17). This group includes (1) cases with cryptic PML/RARA gene rearrangements and t(5;17) that leads to the NPM/RARA fusion gene, which are retinoid-responsive, and (2) cases with t(11;17)(q23;q21) that are associated with the PLZF/RARA fusion gene, which are retinoid-resistant. A key issue is how to rapidly distinguish subtypes of APL that demand distinct treatment approaches. To address this issue, a European workshop was held in Monza, Italy, during June 1997, and a morphologic, immunophenotypic, cytogenetic, and molecular review was undertaken in 60 cases of APL lacking t(15;17). This process led to the development of a novel morphologic classification system that takes into account the major nuclear and cytoplasmic features of APL. There were no major differences observed in morphology or immunophenotype between cases with the classic t(15;17) and those with the cryptic PML/RARA gene rearrangements. Auer rods were absent in the t(5;17) case expressing NPM/RARA. Interestingly, this classification system distinguished 9 cases with t(11;17)(q23;q21) and, in addition, successfully identified 2 cases lacking t(11;17), which were subsequently shown to have underlying PLZF/RARA fusions. The PLZF/RARA cases were characterized by a predominance of blasts with regular nuclei, an increased number of Pelger-like cells, and by expression of CD56 in 4 of 6 cases tested. Use of this classification system, combined with an analysis for CD56 expression, should allow early recognition of APL cases requiring tailored molecular investigations. (Blood. 2000;96:1287-1296)

Hematopoietic damage prior to PBSCT and its influence on hematopoietic recovery

BACKGROUND AND OBJECTIVE

Patients with malignancies receive chemotherapy to induce tumor remission which could damage hematopoiesis and adversely influence hematopoietic reconstitution after transplantation. In the present study we used a long-term culture (LTBMC) system and clonogenic assays to evaluate the marrow damage in patients selected to receive peripheral blood stem cell transplantation (PBSCT).

DESIGN AND METHODS

Thirty-five patients - 20 with breast cancer (BC), 9 with non-Hodgkin's lymphoma (NHL) and 6 with Hodgkin's disease (HD) - were included. Bone marrow aspiration was performed one day prior to the initiation of the conditioning therapy. CFU-GM were cultured in methylcellulose with PHA-LCM. Delta assays of plastic adherent progenitor cells (PD) were performed according to Gordon's method. LTBMC were established for 5 weeks.

RESULTS

There were fewer CFU-GM from all patient groups than from normal BM (p<0.05). In contrast, the number of immature progenitor cells (PD) was not decreased. The total number of CFU-GM produced by LTBMC patients was significantly reduced (p<0.05). The adherent layer from patients was often qualitatively different. In order to know whether the hematopoietic damage could affect hematopoietic reconstitution, we correlated culture data with time taken to reach peripheral cell counts. A negative correlation (r= - 0.71) was found between percentage of stromal layer and time taken to reach 20x10(9) platelets/L (tplat= 20x3-0.08% stromal layer).

INTERPRETATION AND CONCLUSIONS

We can conclude that prior to PBSCT, hematopoietic function is impaired at both the level of committed progenitor cells and that of BM stroma. This damage could influence platelet recovery.

Haematopoietic damage persists 1 year after autologous peripheral blood stem cell transplantation

In the present study we have used cell culture assays in order to assess the damage in the haematopoietic system 1 year after peripheral blood stem cell transplantation (PBSCT), and to establish at what level, haematopoietic progenitor cells (HPC) or stroma, this damage occurs. Thirty-one patients, nine breast cancer (BC), 17 non-Hodgkin lymphoma (NHL) and five Hodgkin disease (HD), who had received autologous PBSCT were included. Forty-eight normal subjects who had given informed consent were used as controls. Results were also compared with a matched group of patients (25 cases) prior to PBSCT. Progenitor cells were analysed using CFU-GM and plastic adherent delta (Pdelta) assays. Long-term bone marrow cultures (LTBMC) in one and two stages were established. One year after transplant both the number of committed progenitor cells and the CFU-GM production in LTBMC were significantly reduced in the three groups of patients when compared with controls (P < 0.05 or P < 0.01). Two-stage LTBMC experiments showed that the impairment in CFU-GM production was due to damage in both patients' stroma and haematopoietic progenitor cells (HPC). All patients, except those with HD, showed a decreased stromal layer confluence (P < 0.05), with significant differences in cell composition as compared to normal bone marrow (P = 0.001). When all these variables were compared with pretransplant results, we observed that stroma formation was significantly lower after PBSCT (P < 0.05), while the number of progenitor cells analysed by the Pdelta assay was significantly increased (P < 0.05). We can conclude that even 1 year after PBSCT, both the committed HPC and BM stroma remain damaged.

Correlation of rhodamine 123 efflux by neoplastic plasma cells with clinical and biological characteristics of multiple myeloma

Although a variable proportion of multiple myeloma patients can achieve response with conventional chemotherapy, residual tumor cells, which are refractory, finally reemerge leading to disease progression. The expression of the multidrug resistance protein (MDR1) has been one of the most extensively explored mechanisms of drug resistance and has been related to a poor response to chemotherapy in several human tumors. Nevertheless, a careful analysis of the literature on MDR1 expression in multiple myeloma (MM) shows the existence of disturbing discrepancies as regards both the incidence of MDR1 over-expression and its clinical value. A prerequisite for the assessment of MDR1 in tumor cells should be the identification of the neoplastic cells present in the sample. This is particularly important in MM, where the percentage of tumor cells in bone marrow (BM) is relatively low. In the present study we have analyzed the functional expression of MDR1 in BM plasma cells (PC), from a group of 40 untreated MM patients. For that purpose, the rhodamine 123 efflux assay was used in combination with specific staining for plasma cells (CD38 strong+). The mean fluorescence channel (MFC) of rhodamine 123 in myelomatous PC from MM patients was 311 and 110 after incubating cells with this fluorochrome for 15 and 60 min, respectively. The median percentage of rhodamine 123 elimination by BM PC was of 61% (range: 0.29 to 88%). Upon analyzing the relationship between the ability of myelomatous PC to eliminate rhodamine 123 and other clinical and biological disease characteristics we found that, within the group of patients displaying high MDR1 expression (>61% rhodamine efflux), there was a higher incidence of cases with bone disease (P = 0.014) and advanced clinical stages (P = 0.031), greater calcium (P = 0.007) and creatinine serum levels (P = 0.061), and lower levels of albumin in serum (P = 0.015). All these parameters are usually associated with a poor prognosis. When we analyzed the possible relationship between the ability of BM PC to eliminate rhodamine 123 and the presence of numerical chromosome abnormalities we observed that a low MDR1 expression was related to a higher incidence of trisomies of chromosomes 6 and 17, although these differences did not reach statistical significance (P = 0.06). In spite of these associations, from the prognostic point of view, MDR1 expression did not correlate with other relevant prognostic factors, response to treatment (P = 0.38) or overall survival (P = 0.12).

Neurological complications after autologous stem cell transplantation

INTRODUCTION

Autologous bone marrow (BMT) or peripheral blood stem cell transplantation (PBSCT) are increasingly used to treat hematological malignancies and solid tumors. The reported incidence of neurological complications varies greatly among the different centers, ranging from 11 to 39%.

PATIENTS AND METHODS

In order to gain insight into the real incidence of early neurological complications (first 6 weeks) after autologous transplantation, we analyzed a series of 254 patients who underwent BMT/PBSCT for hematological malignancies (212 cases) or solid tumors (42 cases).

RESULTS

Seven patients died during the early posttransplant period (incidence: 2.4%), and one of these deaths was related to a neurological complication. Eight patients developed neurologic complications (incidence: 2.8%). None of the patients developed cerebral hemorrhage during the early posttransplant period, despite a rather restrictive platelet transfusion support. Two out of 13 patients diagnosed AML and 3 out of 36 patients diagnosed Hodgkin's disease developed early neurological complications.

DISCUSSION AND CONCLUSIONS

The neurological morbidity related to autologous transplantation was very low in our series of patients as compared to that reported in previous studies. This difference could be explained, at least in part, by a more restrictive definition of early neurologic complications.

Transposon mutants of Staphylococcus epidermidis deficient in elaboration of capsular polysaccharide/adhesin and slime are avirulent in a rabbit model of endocarditis

Virulence comparisons were made in a rabbit model of endocarditis between wild-type and transposon mutants of Staphylococcus epidermidis deficient in elaboration of the capsular polysaccharide/adhesin (PS/A) and slime. The parental phenotype grew from 36 (61%) of 59 cultures of blood. The PS/A-negative phenotype grew in 1 (1%) of 98 cultures of blood (P < .001). No animals infected with PS/A-negative strains developed endocarditis compared with 75% of rabbits infected with PS/A-positive strains. PS/A-producing strains survived better than did PS/A-deficient strains in intact, absorbed rabbit or human serum plus human leukocytes. There was also greater deposition of C3 onto the PS/A-deficient strains than with the PS/A-producing isogenic strains. PS/A functions as an antiphagocytic bacterial capsule preventing C3 deposition and phagocytosis; loss of this structure increases the strain's susceptibility to opsonic killing and decreases its virulence.

Isolation and characterization of transposon mutants of Staphylococcus epidermidis deficient in capsular polysaccharide/adhesin and slime

We used transposon (Tn) mutagenesis to study the role of capsular polysaccharide/adhesin (PS/A) and slime in adherence of Staphylococcus epidermidis to catheters. pLTV1, containing Tn917-LTV1, was transformed into S. epidermidis M187 by protoplast fusion with S. aureus RN4220(pLTV1), creating M187(pLTV1). Tn mutants were isolated following growth at 42 degrees C; mutants deficient in PS/A and slime production were selected. PS/A- and slime-deficient Tn mutants had a 10-fold decrease in vitro in the initial phase of adherence to catheters, comparable to levels of strains that do not produce PS/A. Introduction of Tn917-LTV1-interrupted DNA from PS/A-deficient mutant M187sn3 into the parental strain via transformation of protoplasts yielded recipients with inserts identical to those of the Tn mutant that were PS/A and slime deficient. Chromosomal DNA flanking the Tn in mutant M187sn3 was cloned into Escherichia coli. The cloned DNA was found to hybridize to approximately 5-kb EcoRI fragments from the parental strain and from control Tn mutants that express parental levels of PS/A and to either approximately 9- or approximately 14-kb EcoRI fragments from other highly adherent, PS/A-producing strains. Mapping studies demonstrated that in the eight PS/A-deficient mutants that have been isolated, the Tn insertions all occur within a region of approximately 11.6 kb that is defined by three EcoRI sites. These results support previous findings indicating that in S. epidermidis PS/A is involved with in vitro adherence to plastic biomaterials and elaboration of PS/A is closely associated with slime production.

Haematology and erythrocyte metabolism in man at high altitude: an Aymara-Quechua comparison

In the course of haematological and biological investigations among Aymara and Quechua populations in Bolivia, an anthropological study of the erythrocytary respiratory function was carried out on the two groups at two altitudes: 3,600 m and 450 m. A difference in the intensity of the biological variations of the two populations is observed at high altitude. In the Quechuas, as in any lowland native, the adaptative phenomena are totally and quickly reversible. In the Aymaras, we detected the existence of more marked haematological and biochemical characters: moderate polycythemia, hyperhaemoglobinemia, microcytosis, metabolical hyperactivity with accumulation of 2-3 di-phosphoglycerate and ATP, and methaemoglobinemia with a drop in the activity of the methaemoglobin reductases. The Aymaras preserve some of those characters (methaemoglobinemia excepted) when they settle in lowlands.

The problem of cardiac valve prostheses, anticoagulants, and pregnancy

To assess the maternal and fetal risks in patients with cardiac valve prostheses, a series of 223 pregnancies in 156 women was studied. In 68 pregnancies (group I) treatment with antiplatelet agents was substituted for that with coumarinics from the first trimester on. Group II (128 pregnancies) received coumarinics through the thirty-eighth week of gestation. Three patients in group I died as a result of thrombosis of their caged-ball valves. The incidence of cerebral embolism was 25.0% in group I and 2.3% in group II patients, while that of spontaneous abortion was 10.3% and 28.1%, respectively. Coumarin embryopathy was found in 7.9% of group II infants. Fetal death did not occur in the 12 cases in which subcutaneous heparin was substituted for the coumarin derivative in the first trimester and the last 2 weeks of pregnancy (group III), but maternal cerebral embolism developed in 8.3% of the patients. Finally, uneventful pregnancies and deliveries were observed in 12 of 15 mothers (group IV) with biological prostheses who received no anticoagulants. It is concluded that (1) women with cardiac valve prostheses should be counseled against becoming pregnant, (2) antiplatelet agents do not provide protection against thromboembolism in these patients, (3) because of the high incidence of fetal death and birth defects use of coumarinics is contraindicated in the first trimester and the last weeks of pregnancy, (4) the substitution of heparin at these times may decrease the incidence of these complications, and (5) bioprostheses are indicated in women who wish to bear children.

Human red cell glycolysis in high altitude chronic hypoxia

We have found that glycolysis in human red blood cells under the hypoxic conditions found at high altitudes is connected with changes in enzyme activities and levels of various metabolic intermediates. The sensitivity of the four kinases to hypoxia results in 1) glycolytic hyperactivity leading to a higher intracellular energy state, and 2) accumulation of 2-3 DPG, whose role in the adaptation of red blood cell respiration to high altitude has been shown by previous research. PEP, 3PG , and G6P appear to be the main regulating intermediates in glycolysis in this system. The reason for the very large increase in G1- 6DP is still not clear.

Methaemoglobin and erythrocyte reducing systems in high-altitude natives

The stress of chronic hypobaric hypoxia present at high altitudes induces a series of adaptive changes in the intermediate metabolism in erythrocytes of high-altitude natives. Aymaras of the high Andean Plateau are shown to have within erythrocytes: (a) increased activity of NADH2 (GAPDH) generating stages, (b) decreased activity of NADH2 (LDH) consuming steps, (c) significantly increased methaemoglobin content, and (d) a large increase in the level of reduced glutathione. These alterations occur also in persons of the same ethnic group residing at low altitude. There is, however, only a moderate elevation of classic haematological parameters (erythrocyte count, haemoglobin and haematocrit) in highland natives. The functional implications of these metabolite changes are discussed with respect to regulation of erythrocyte metabolism.