The use of Faecal Microbiota Transplantation (FMT) in Europe: A Europe-wide survey

Background

Faecal microbiota transplantation (FMT) is an emerging treatment modality, but its current clinical use and organisation are unknown. We aimed to describe the clinical use, conduct, and potential for FMT in Europe.

Methods

We invited all hospital-based FMT centres within the European Council member states to answer a web-based questionnaire covering their clinical activities, organisation, and regulation of FMT in 2019. Responders were identified from trials registered at clinicaltrials.gov and from the United European Gastroenterology (UEG) working group for stool banking and FMT.

Findings

In 2019, 31 FMT centres from 17 countries reported a total of 1,874 (median 25, quartile 10-64) FMT procedures; 1,077 (57%) with Clostridioides difficile infection (CDI) as indication, 791 (42%) with experimental indications, and 6 (0•3%) unaccounted for. Adjusted to population size, 0•257 per 100,000 population received FMT for CDI and 0•189 per 100,000 population for experimental indications. With estimated 12,400 (6,100-28,500) annual cases of multiple, recurrent CDI and indication for FMT in Europe, the current European FMT activity covers approximately 10% of the patients with indication. The participating centres demonstrated high safety standards and adherence to international consensus guidelines. Formal or informal regulation from health authorities was present at 21 (68%) centres.

Interpretation

FMT is a widespread routine treatment for multiple, recurrent CDI and an experimental treatment. Embedded within hospital settings, FMT centres operate with high standards across Europe to provide safe FMT. A significant gap in FMT coverage suggests the need to raise clinical awareness and increase the FMT activity in Europe by at least 10-fold to meet the true, indicated need.

Funding

NordForsk under the Nordic Council and Innovation Fund Denmark (j.no. 8056-00006B).

Abstract S1-09: A comparison of the diagnostic performance of 2D synthetic mammography versus digital breast tomosynthesis in 2500 patients

Introduction: A synthetic 2D mammogram (C-view) can be created by combining the individual optimally enhanced 1mm slices of a digital breast tomosynthesis (DBT). Studies show that screening with 2D mammography and DBT increases the cancer detection rate by about 40% and reduces the recall rate by about 25% but it doubles the x-ray exposure to the patient and reading time for the radiologist compared to standard 2D screening. The use of a synthetic 2D instead of a standard 2D film may theoretically overcome these problems by avoiding a second exposure and presenting the detail normally available in DBT in one picture. The hypothesis we wished to test is, "if the synthetic 2D is normal/benign, is there any advantage in also viewing the DBTs?"

Method: We prospectively collected data on 2500 unselected cases presenting symptomatically or at follow up, all of whom underwent DBT on a Hologic® Dimensions machine. From the 3D data sets synthetic 2D mammograms were constructed (Hologic C-view). One breast radiologist with 13 years experience of interpreting mammograms and 5 years with DBTs was asked to review the 2D synthetic mammograms (CC and MLO) and report them before then reviewing the DBTs and issuing a final report. The mammograms were reported M1 to M5 using the standard BIRADs criteria. The BIRADs scores for each breast were recorded prospectively. Similarly the breast density as assessed by eye was recorded (fatty/average density/dense).

Results: 2500 patients were studied between October 2013 and October 2014. The average age of the women was 58.4 years (range 28-95). Of these some were under follow up after mastectomies so in total there were 4589 individual mammogram sets reported. Table 1 summarises the correlation between the synthetic 2D and DBT reports.

BIRADS Classification - Synthetic 2D v DBT Synthetic 2D   M1M2M3M4M5 M115874000 M2827051510DBTM32810140 M4015480 M5001396

The correlation is very close, but there were 11 patients in whom the synthetic 2D was reported normal or benign (M1 or M2) but the DBT was reported as M3. Of these 10 were benign on assessment and one malignant. There was one patient reported as M2 on synthetic 2D but M4 on DBT. Assessment confirmed malignancy. Sixteen cases reported as suspicious of malignancy (M3/4) by synthetic 2D were subsequently downgraded to benign after review of the DBT. We estimate that 2D mammography alone would have detected only 68 of the 94 detected by synthetic 2D.

Of the 4589 examinations, 1131 (25%) were assessed as fatty, 1851 (40%) as average density and 1607 (35%) as dense. One cancer was missed in an averagely dense and one in a dense breast.

Conclusion: In a symptomatic and follow up clinic, our study suggests that much radiologist's time and x-ray exposure to the patient could be saved by using synthetic 2D mammograms rather than using 2D/3D combinations. Only if the synthetic 2D is reported M3, 4 or 5 is it necessary to review the DBT. Whilst a similar trial is required to confirm these findings in a screening population, this trial suggests that synthetic 2D mammography could be cost effective compared to combination 2D/3D.

Citation Format: Holt SD, Sharaiha YM, Moalla A, Williams HR, Thomas D, Huws AM. A comparison of the diagnostic performance of 2D synthetic mammography versus digital breast tomosynthesis in 2500 patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr S1-09.

Abstract P1-02-02: A review of 66 consecutive patients investigated for mammographic abnormalities by digital tomosynthesis guided vacuum assisted breast biopsy

OBJECTIVE: Vacuum-assisted breast biopsy (VABB) has replaced surgical biopsy for the assessment of mammographic abnormalities that are not evident clinically and or on ultrasound examination. The aim of this study was to determine the indications for, and accuracy of, vacuum-assisted breast biopsy (VABB) performed using digital breast tomosynthesis (DBT) guidance. (Hologic® Dimensions, Affirm guidance and Eviva handsets).

MATERIALS AND METHODS:

Design: Retrospective medical record and histopathologic review.

Patients and method: We introduced DBT guided VABB in June 2014 having previously investigated such patients using the prone table technique. This is a review of the first 66 consecutive patients investigated using this technique up to April 2105.

The following information was reviewed: Indication for VABB, (mammographic classification M1-5, type of abnormality – calcifications/mass/distortion), complications of the procedure itself, (failure to complete, infection, haematoma), the result of the multidisciplinary team (MDT) review of imaging/pathologic correlation and the outcome for the patient.

RESULTS: In one case it proved impossible to locate the lesion and this patient has been excluded from further analysis. The mean age of the patients was 57 years (30-80years). VABB was proposed for patients with lesions initially reported as highly suspicious (M5) 4 patients (6%), suspicious (M4) in 18 patients (28%), intermediate (M3) in 37 patients (57%) or benign (M2) in 6 patients (9%). Mean size of the lesion was 13mm (range 3-100mm). Forty-four patients (68%) presented with micro calcifications, 14 (21%) with distortions in and 7 (11%) with masses.

There were no complications (infection or haematoma) that required further management following the procedure.

Review by the MDT agreed that all biopsies were adequate and removed representative tissue from the lesion (No B1s). Review showed that the histology was benign and consistent in 30 (46%) patients all of whom were discharged to routine screening. 19 (29%) cases were reported as B3 (ADH, flat atypia, LCIS or ALH) in whom all the calcifications had been removed in 13 (20%) and the patients discharged and 6 (9%) went to open biopsy for residual calcifications all of whom were benign on final analysis. There was one (1.5%) radial scar reported as B4 that went to open excision and proved benign. 15 (23%) proved malignant (B5a, B5b) and went on to definitive treatment (with one patient entered into the LORIS low risk DCIS trial).

The procedure is quicker, more accurate (related to the higher resolution and larger window of the receptor plate) and involves less radiation exposure (often involving only one DBT exposure) when compared to performing the same procedure on the Hologic Platinum prone table.

CONCLUSION: DBT-guided VABB is an accurate, convenient and safe procedure.

Citation Format: Munir A, Moalla A, Williams HR, Thomas D, Huws AM, Holt SD. A review of 66 consecutive patients investigated for mammographic abnormalities by digital tomosynthesis guided vacuum assisted breast biopsy. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-02-02.

All-sky LIGO search for periodic gravitational waves in the early fifth-science-run data

We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1100 Hz and with the frequency's time derivative in the range -5 x 10{-9}-0 Hz s{-1}. Data from the first eight months of the fifth LIGO science run (S5) have been used in this search, which is based on a semicoherent method (PowerFlux) of summing strain power. Observing no evidence of periodic gravitational radiation, we report 95% confidence-level upper limits on radiation emitted by any unknown isolated rotating neutron stars within the search range. Strain limits below 10{-24} are obtained over a 200-Hz band, and the sensitivity improvement over previous searches increases the spatial volume sampled by an average factor of about 100 over the entire search band. For a neutron star with nominal equatorial ellipticity of 10{-6}, the search is sensitive to distances as great as 500 pc.

All-sky LIGO search for periodic gravitational waves in the early fifth-science-run data

We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1100 Hz and with the frequency's time derivative in the range -5 x 10{-9}-0 Hz s{-1}. Data from the first eight months of the fifth LIGO science run (S5) have been used in this search, which is based on a semicoherent method (PowerFlux) of summing strain power. Observing no evidence of periodic gravitational radiation, we report 95% confidence-level upper limits on radiation emitted by any unknown isolated rotating neutron stars within the search range. Strain limits below 10{-24} are obtained over a 200-Hz band, and the sensitivity improvement over previous searches increases the spatial volume sampled by an average factor of about 100 over the entire search band. For a neutron star with nominal equatorial ellipticity of 10{-6}, the search is sensitive to distances as great as 500 pc.

All-sky LIGO search for periodic gravitational waves in the early fifth-science-run data

We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1100 Hz and with the frequency's time derivative in the range -5 x 10{-9}-0 Hz s{-1}. Data from the first eight months of the fifth LIGO science run (S5) have been used in this search, which is based on a semicoherent method (PowerFlux) of summing strain power. Observing no evidence of periodic gravitational radiation, we report 95% confidence-level upper limits on radiation emitted by any unknown isolated rotating neutron stars within the search range. Strain limits below 10{-24} are obtained over a 200-Hz band, and the sensitivity improvement over previous searches increases the spatial volume sampled by an average factor of about 100 over the entire search band. For a neutron star with nominal equatorial ellipticity of 10{-6}, the search is sensitive to distances as great as 500 pc.

All-sky LIGO search for periodic gravitational waves in the early fifth-science-run data

We report on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1100 Hz and with the frequency's time derivative in the range -5 x 10{-9}-0 Hz s{-1}. Data from the first eight months of the fifth LIGO science run (S5) have been used in this search, which is based on a semicoherent method (PowerFlux) of summing strain power. Observing no evidence of periodic gravitational radiation, we report 95% confidence-level upper limits on radiation emitted by any unknown isolated rotating neutron stars within the search range. Strain limits below 10{-24} are obtained over a 200-Hz band, and the sensitivity improvement over previous searches increases the spatial volume sampled by an average factor of about 100 over the entire search band. For a neutron star with nominal equatorial ellipticity of 10{-6}, the search is sensitive to distances as great as 500 pc.

Search for gravitational-wave bursts from soft gamma repeaters

We present a LIGO search for short-duration gravitational waves (GWs) associated with soft gamma ray repeater (SGR) bursts. This is the first search sensitive to neutron star f modes, usually considered the most efficient GW emitting modes. We find no evidence of GWs associated with any SGR burst in a sample consisting of the 27 Dec. 2004 giant flare from SGR 1806-20 and 190 lesser events from SGR 1806-20 and SGR 1900+14. The unprecedented sensitivity of the detectors allows us to set the most stringent limits on transient GW amplitudes published to date. We find upper limit estimates on the model-dependent isotropic GW emission energies (at a nominal distance of 10 kpc) between 3x10;{45} and 9x10;{52} erg depending on waveform type, detector antenna factors and noise characteristics at the time of the burst. These upper limits are within the theoretically predicted range of some SGR models.

Biomimetic reliability strategies for self-healing vascular networks in engineering materials

Self-healing via a vascular network is an active research topic, with several recent publications reporting the application and optimization of these systems. This work represents the first consideration of the probable failure modes of a self-healing system as a driver for network design. The critical failure modes of a proposed self-healing system based on a vascular network were identified via a failure modes, effects and criticality analysis and compared to those of the human circulatory system. A range of engineering and biomimetic design concepts to address these critical failure modes is suggested with minimum system mass the overall design driver for high-performance systems. Plant vasculature has been mimicked to propose a segregated network to address the risk of fluid leakage. This approach could allow a network to be segregated into six separate paths with a system mass penalty of only approximately 25%. Fluid flow interconnections that mimic the anastomoses of animal vasculatures can be used within a segregated network to balance the risk of failure by leakage and blockage. These biomimetic approaches define a design space that considers the existing published literature in the context of system reliability.

Self-healing polymer composites: mimicking nature to enhance performance

Autonomic self-healing materials, where initiation of repair is integral to the material, are being developed for engineering applications. This bio-inspired concept offers the designer an ability to incorporate secondary functional materials capable of counteracting service degradation whilst still achieving the primary, usually structural, requirement. Most materials in nature are themselves self-healing composite materials. This paper reviews the various self-healing technologies currently being developed for fibre reinforced polymeric composite materials, most of which are bioinspired, inspired by observation of nature. The most recent self-healing work has attempted to mimic natural healing through the study of mammalian blood clotting and the design of vascular networks found in biological systems. A perspective on current and future self-healing approaches using this biomimetic technique is offered. The intention is to stimulate debate outside the engineering community and reinforce the importance of a multidisciplinary approach in this exciting field.

CCR5, CXCR4, and CD4 are clustered and closely apposed on microvilli of human macrophages and T cells

The chemokine receptors CCR5 and CXCR4 act synergistically with CD4 in an ordered multistep mechanism to allow the binding and entry of human immunodeficiency virus type 1 (HIV-1). The efficiency of such a coordinated mechanism depends on the spatial distribution of the participating molecules on the cell surface. Immunoelectron microscopy was performed to address the subcellular localization of the chemokine receptors and CD4 at high resolution. Cells were fixed, cryoprocessed, and frozen; 80-nm cryosections were double labeled with combinations of CCR5, CXCR4, and CD4 antibodies and then stained with immunogold. Surprisingly, CCR5, CXCR4, and CD4 were found predominantly on microvilli and appeared to form homogeneous microclusters in all cell types examined, including macrophages and T cells. Further, while mixed microclusters were not observed, homogeneous microclusters of CD4 and the chemokine receptors were frequently separated by distances less than the diameter of an HIV-1 virion. Such distributions are likely to facilitate cooperative interactions with HIV-1 during virus adsorption to and penetration of human leukocytes and have significant implications for development of therapeutically useful inhibitors of the entry process. Although the mechanism underlying clustering is not understood, clusters were observed in small trans-Golgi vesicles, implying that they were organized shortly after synthesis and well before insertion into the cellular membrane. Chemokine receptors normally act as sensors, detecting concentration gradients of their ligands and thus providing directional information for cellular migration during both normal homeostasis and inflammatory responses. Localization of these sensors on the microvilli should enable more precise monitoring of their environment, improving efficiency of the chemotactic process. Moreover, since selectins, some integrins, and actin are also located on or in the microvillus, this organelle has many of the major elements required for chemotaxis.

Substituted 2-aminopyridines as inhibitors of nitric oxide synthases

A series of substituted 2-aminopyridines was prepared and evaluated as inhibitors of human nitric oxide synthases (NOS). 4,6-Disubstitution enhanced both potency and specificity for the inducible NOS with the most potent compound having an IC50 of 28 nM.

Complications of tibial shaft soccer fractures

A retrospective study of AO type 42 tibial diaphyseal fractures that presented to a teaching hospital over a 54 month period was made to identify the proportion sustained whilst playing soccer, determine their characteristics and report treatment and outcome. Sport accounts for 73/329 (22.1%) of these fractures and soccer 58/73 (79. 5%) of these. All patients were male with mean age of 24.3 years (range 8-48). Fifty-four fractures were closed and 93.1% (54/58) were situated in the middle third or at the junction of the middle and distal thirds of the diaphysis. Fifty-six (96.6%) had simple or wedge patterns and 45 (77.6%) were right sided. Forty-four (76.2%) were treated non-operatively in plaster, 12 (20.3%) by intramedullary nails and two (3.4%) with external fixators. Two patients were lost to follow-up and the remaining 56 fractures united at a mean of 6.5 months. There were 21 complications in 19/56 (33.9%) patients which included 8/56 (14.3%) delayed/non-unions requiring surgery. There was a significantly higher complication rate for operated fractures (p<0.005) but no significant link to AO fracture type. Thus we cannot assume that treatment of these common fractures is without risk, especially if they are treated operatively.

Castleman's disease of the erector spinae muscle

Castleman's disease, angio-follicular lymph node hyperplasia, is a relatively rare benign tumour. It typically arises in the mediastinum. We report a unique case arising in the erector spinae muscle. The case demonstrates the importance of radiological investigation and embolisation prior to obtaining a tissue diagnosis and subsequent surgical excision.

Out-patient follow-up after routine surgery: a questionnaire study

A questionnaire was sent to all consultant general surgeons and urologists in Wales to assess current practice in out-patient follow-up after surgery for nine commonly performed procedures. A further questionnaire was sent to a random sample of general practitioners in South Glamorgan to assess the possibility of GPs taking on responsibility for post-operative follow-up. This should, therefore, reduce the number of post-operative patients passing through the out-patient department. Of the 58 (77%) consultants who responded, the percentage who routinely followed up patients with at least one post-operative visit was calculated. Of the 33 (66%) GPs who responded the percentage who were prepared to take responsibility for post-operative follow-up was calculated for patients having the same operations. There was agreement and disagreement between consultants and GPs, but not distinct pattern emerged. A larger study must be performed before the out-patient department is rationalized using protocols based on this study.

Aggrecanase and metalloproteinase-specific aggrecan neo-epitopes are induced in the articular cartilage of mice with collagen II-induced arthritis

OBJECTIVE

To analyze the roles of two classes of proteinases, 'aggrecanase', and matrix metalloproteinases (MMPs), in chondrodestruction during murine collagen-induced arthritis (CIA).

METHODS

Generation of the 'aggrecanase' neo-epitope (NITEGE373), and the MMP neo-epitope (VDIPEN341) within aggrecan was studied by immunoperoxidase microscopy using specific anti-peptide antibodies in normal and stromelysin-1 (SLN-1) deficient knockout mice with CIA.

RESULTS

High levels of NITEGE373 and VDIPEN341 neo-epitopes were observed in foci within CIA paw articular cartilage exhibiting depletion of glycosaminoglycans, in advance of significant cartilage erosion. The highest concentrations of NITEGE373 and VDIPEN341 labeling were observed and often co-distributed in the chondrocyte pericellular matrix, suggesting that stimulated chondrocytes can synthesize and/or activate both enzymes. Other regions of the cartilage frequently exhibited either NITEGE373 or VDIPEN341 labeling, but not both neo-epitopes simultaneously, suggesting that 'aggrecanase' and MMP cleavages of aggrecan may be generated independently. No detectable differences were observed in expression or distribution of either neo-epitope in SLN-1 knockout versus wild-type mice. In addition, in vitro digestion of joint sections with SLN-1 did not alter the expression of cartilage NITEGE373, while markedly increasing VDIPEN341 labeling. Peripheral nerves and brains of naive mice also exhibited intense anti-NITEGE373 labeling.

CONCLUSIONS

These data indicate that NITEGE373 and VDIPEN341 aggrecan neo-epitopes are sensitive and specific markers of early joint pathology, and are consistent with the hypothesis that SLN-1 does not have 'aggrecanase' activity, and that 'aggrecanase' is distinct from the MMPs which cleave aggrecan at the MMP site.

Aggrecan degradation in human cartilage. Evidence for both matrix metalloproteinase and aggrecanase activity in normal, osteoarthritic, and rheumatoid joints

To examine the activity of matrix metalloproteinases (MMPs) and aggrecanase in control and diseased human articular cartilage, metabolic fragments of aggrecan were detected with monospecific antipeptide antibodies. The distribution and quantity of MMP-generated aggrecan G1 fragments terminating in VDIPEN341 were compared with the distribution of aggrecanase-generated G1 fragments terminating in NITEGE373. Both types of G1 fragments were isolated from osteoarthritic cartilage. The sizes were consistent with a single enzymatic cleavage in the interglobular domain region, with no further proteolytic processing of these fragments. Both neoepitopes were also detected by immunohistochemistry in articular cartilage from patients undergoing joint replacement for osteoarthritis (OA), rheumatoid arthritis (RA), and in cartilage from adults with no known joint disease. In control specimens, the staining intensity for both G1 fragments increased with age, with little staining in cartilage from 22-wk-old fetal samples. There was also an increase with age in the extracted amount of MMP-generated neoepitope in relation to both aggrecan and collagen content, confirming the immunohistochemical results. After the age of 20-30 yr this relationship remained at a steady state. The staining for the MMP-generated epitope was most marked in control cartilage exhibiting histological signs of damage, whereas intense staining for the aggrecanase-generated fragment was often noted in adult cartilage lacking overt histological damage. Intense staining for both neoepitopes appeared in the more severely fibrillated, superficial region of the tissue. Intense immunostaining for both VDIPEN- and NITEGE- neoepitopes was also detected in joint cartilage from patients with OA or RA. Cartilage in these specimens was significantly more degraded and high levels of staining for both epitopes was always seen in areas with extensive cartilage damage. The levels of extracted VDIPEN neoepitope relative to collagen or aggrecan in both OA and RA samples were similar to those seen in age-matched control specimens. Immunostaining for both types of aggrecan fragments was seen surrounding the cells but also further removed in the interterritorial matrix. In some regions of the tissue, both neoepitopes were found while in others only one was detected. Thus, generation and/or turnover of these specific catabolic aggrecan fragments is not necessarily coordinated. Our results are consistent with the presence in both normal and arthritic joint cartilage of proteolytic activity against aggrecan based on both classical MMPs and "aggrecanase."

An audit of trauma documentation

Research into aspects of the care of the injured depends on accurate and complete documentation. Inadequate records make audit almost impossible and are unacceptable medico-legally. An audit was made of the standard of trauma documentation in the Yorkshire region before the introduction of trauma charts in 1992. After it was established that a problem did exist, an audit was made of the standard of documentation before and after introduction of trauma charts in one city teaching hospital. Case notes were inspected for completeness of documentation of respiratory, circulatory and neurological status. Results from 1988-1989 showed that only 39.4 per cent of notes recorded the four parameters under investigation. In 1992-1994 the standard had improved. Without trauma charts documentation increased to 90 per cent, but with trauma charts in primary referrals the result improved to 97 per cent. Only 56 per cent of notes were complete for tertiary referrals when a trauma chart was not used. The standard of documentation in major injuries improved with the use of trauma charts. It is recommended that trauma charts are used routinely for all primary and tertiary referrals of injured patients. Tertiary referral patients should be reassessed fully after hospital transfer and a new trauma chart completed.

Audit of thromboembolic prophylaxis in hip and knee surgery

An audit of the departmental policy for thromboembolic prophylaxis was undertaken, examining the use of TED stockings, administration of subcutaneous low-dose heparin and inclusion into a multicentre pulmonary embolism prevention (PEP) trial for fractured neck of the femur. The results showed that despite an established unit policy, only 43% of patients undergoing primary hip replacement and 14% undergoing revision replacement received subcutaneous heparin. All patients undergoing primary and revision total knee replacement received subcutaneous heparin, but 75% of these patients received an incorrect dose. Use of TED stockings in patients who had sustained a fractured neck of the femur, ranged from 0% to 70% depending on the type of fixation. Use of subcutaneous heparin in these patients ranged between 0% and 20% and inclusion into the PEP trial from 0% to 20%. The results of this study were presented to the clinicians working in the orthopaedic department and 3 months later the audit cycle was completed by repeating the study. It was found there was a statistically significant improvement in the administration of subcutaneous heparin and in the wearing of TED stockings in the joint arthroplasty group as well as in the inclusion of hip fracture patients into the PEP trial. This study demonstrates that established protocols are of little value unless audited and that completion of the audit cycle is essential. It does not attempt to show that one prophylactic method is better than another.

Expression and immunoaffinity purification of human inducible nitric-oxide synthase. Inhibition studies with 2-amino-5,6-dihydro-4H-1,3-thiazine

Recombinant human inducible nitric-oxide synthase (rH-iNOS) was expressed in the baculovirus system and purified by a novel immunoaffinity column. rH-iNOS and its native counterpart from cytokine-stimulated primary hepatocytes exhibited similar molecular mass of 130 kDa on SDS-polyacrylamide gel electrophoresis, recognition by antipeptide antibodies, specific activities, and IC50 values for inhibitors. The active dimeric form exhibited a specific activity range of 114-260 nmol/min/mg at 37 degrees C and contained 1.15 +/- 0.04 mol of calmodulin/monomer. The enzyme exhibited a Soret lambdamax at 396 nm with a shoulder at 460 nm and contained 0. 28-0.64 mol of heme/monomer. Dithionite reduction under CO yielded an absorbance maximum at 446 nm, indicating a P450-type heme. Imidazole induced a type II difference spectrum, reversible by L-Arg. 2-Amino-5,6-dihydro-4H-1,3-thiazine (ADT) was competitive versus L-Arg (Ki = 22.6 +/- 1.9 nM), reversed the type II difference spectrum induced by imidazole (Kd = 17.7 nM), and altered the CO-ferrous absorbance of rH-iNOS. L-Arg did not perturb the CO-ferrous adduct directly, but it partially reversed the ADT-induced absorbance shift, indicating that both bind similarly to the protein but interact differently with the heme.

VDIPEN, a metalloproteinase-generated neoepitope, is induced and immunolocalized in articular cartilage during inflammatory arthritis

The destruction of articular cartilage in immune inflammatory arthritic disease involves the proteolytic degradation of its extracellular matrix. The role of activated matrix metalloproteinases (MMPs) in the chondrodestructive process was studied by identifying a selective cleavage product of aggrecan in murine arthritis models initiated by immunization with either type II collagen or proteoglycan. We conducted semiquantitative immunocytochemical studies of VDIPEN341 using a monospecific polyclonal antibody requiring the free COOH group of the COOH-terminal Asn for epitope detection. This antibody recognizes the aggrecan G1 domain fragment generated by MMP [i.e., stromelysin (SLN) or gelatinase A] cleavage of aggrecan between Asn341-Phe342 but does not recognize intact aggrecan. VDIPEN was undetectable in normal mouse cartilage but was observed in the articular cartilage (AC) of mice with collagen-induced arthritis 10 d after immunization, without histological damage and clinical symptoms. This aggrecan neoepitope was colocalized with high levels of glycosaminoglycans (GAGs) in pericellular matrices of AC chondrocytes but was not seen at the articular surface at this early time. Digestion of normal (VDIPEN negative) mouse paw cryosections with SLN also produced heavy pericellular VDIPEN labeling. Computer-based image analysis showed that the amount of VDIPEN expression increased dramatically by 20 d (70% of the SLN maximum) and was correlated with GAG depletion. Both infiltration of inflammatory cells into the synovial cavity and early AC erosion were also very prominent at this time. Analysis of adjacent sections showed that both induction of VDIPEN and GAG depletion were strikingly codistributed within sites of articular cartilage damage. Similar results occurred in proteoglycan-induced arthritis, a more progressive and chronic model of inflammatory arthritis. These studies demonstrate for the first time the MMP-dependent catabolism of aggrecan at sites of chondrodestruction during inflammatory arthritis.

Cell-mediated catabolism of aggrecan. Evidence that cleavage at the "aggrecanase" site (Glu373-Ala374) is a primary event in proteolysis of the interglobular domain

A rat chondrosarcoma cell line and primary bovine chondrocytes have been used to study cell-mediated aggrecan catabolism. Addition of 1 microM retinoic acid to chondrosarcoma cultures resulted in aggrecan proteolysis with the release of greater than 90% of the cell layer aggrecan into the medium within 4 days. NH2-terminal sequencing of chondroitin sulfate-substituted catabolic products gave a single major NH2-terminal sequence of ARGNVILTXK, initiating at Ala374. This showed that the proteinase, commonly referred to as "aggrecanase," which cleaves the Glu373-Ala374 bond of the interglobular domain of aggrecan (Sandy, J. D., Neame, P. J., Boynton, R. E., and Flannery, C. R. (1990) J. Biol. Chem. 266, 8683-8685), is active in this cell system. Aggrecan G1 domain, generated by cleavage of the interglobular domain, was also liberated during catabolism and this was characterized with three antipeptide antisera. Anti-CDAGWL was used as a general probe for G1 domain. Anti-FVDIPEN was used to specifically detect G1 domain with COOH terminus of Asn341, the form which is readily generated by cleavage of aggrecan by a wide range of matrix metalloproteinases. Anti-NITEGE antiserum was used to specifically detect G1 domain with COOH terminus of Gln373, the form which is the expected product of "aggrecanase"-mediated cleavage of aggrecan. Western blot analysis indicated that a single form of G1 domain of about 60 kDa was formed. G1 domain of this size reacted with both anti-CDAGWL and anti-NITEGE but not with anti-FVDIPEN. Similar experiments with primary bovine chondrocyte cultures, treated with either retinoic acid or interleukin 1, showed that two forms of catabolic G1 domain, of about 62 and 66 kDa, were formed. Both of these forms reacted on Western blots with anti-CDAGWL and also with anti-NITEGE. It is suggested that cell-mediated catabolism of the aggrecan interglobular domain in these culture systems, whether promoted by retinoic acid or interleukin 1, primarily involves cleavage of the Glu373-Ala374 bond by aggrecanase. The accumulation of G1 domain with a COOH-terminal of Glu373 shows that such aggrecanase-mediated cleavage can occur independent of the cleavage of the Asn341-Phe342 bond by matrix metalloproteinases.

Laparoscopic cholecystectomy: the first 155 patients

Laparoscopic cholecystectomy has been attempted in 155 patients. Eight patients required conversion to open cholecystectomy (5%): three owing to lack of clear anatomical detail, two procedures were abandoned because of instrument failure, two had a dilated common bile duct on cholangiography, and one owing to a very adherent mucocele of the gallbladder. Cholangiography was performed selectively; successfully completed in 45 (22% of all patients). Common bile duct stones were found in two patients. All patients were drained, with two bile leaks, one requiring a laparotomy. There was one ductal injury. Most patients (85%) were discharged within 48 h. This initial experience suggests laparoscopic cholecystectomy is the procedure of choice for most patients with symptomatic cholelithiasis.

Programmed electrical stimulation of the ventricle: an efficient, sensitive, and specific protocol

A relatively simple and efficient ventricular programmed electrical stimulation (PES) protocol was developed, capable of achieving high degrees of sensitivity and specificity. In a series of 481 subjects, 1, 2, and 3 extrastimuli (ES) were used successively during sinus rhythm and ventricular pacing at two drive cycle lengths, at one or more ventricular sites, together with rapid ventricular pacing, and other maneuvers such as isoproterenol infusion. Three ES were used immediately after two ES at each drive rate, rather than returning after completion of the protocol with two ES. Using the protocol, appropriate arrhythmias could be induced in 88% of all patients with ventricular fibrillation, 84% of all patients with sustained ventricular tachycardia (91% with underlying coronary disease), and 58% of patients with severe nonsustained ventricular tachycardia. There were significant differences in inducibility between patients whose ventricular arrhythmias were due to coronary artery disease and other causes. In contrast, sustained ventricular arrhythmias (all ventricular fibrillation) could be induced in only 5% of a control group of control patients, for a specificity of 95%. The protocol described is simpler and more efficient than those that use exhaustive testing of two ES before going to three ES. Three ES during sinus rhythm proved to be the most productive step, with a higher yield ratio (true: false-positives) than two ES or three ES during pacing, especially at faster rates. Greater efficiency is also achieved by leaving the timing of an extrastimulus just beyond its effective refractory period when an additional extrastimulus is to be added, compared to protocols in which the extrastimulus is moved later in the cycle and then decremented in tandem with the additional extrastimulus. Coupling intervals less than 200 msec produced some false-positives, but fewer overall than intervals greater than or equal to 200 msec, and with yield ratios comparable to other protocol steps. The protocol described meets NASPE standards for ventricular programmed stimulation protocols, and with its demonstrated specificity and relative simplicity and efficiency may be useful as a model for groups not yet committed to an alternative protocol.

Purification and characterization by fast-atom-bombardment mass spectrometry of the polymorphonuclear-leucocyte-elastase-generated A alpha (1-21) fragment of fibrinogen from human blood after incubation with calcium ionophore A23187

The stimulation of human blood with a Ca2+ ionophore, A23187, leads to activation of polymorphonuclear leucocytes (PMN) with release of small amounts of catalyticaly active elastase, as demonstrated by the formation of a characteristic product, the N-terminal A alpha (1-21) peptide of the Aa subunit of fibrinogen. The identity of the peptide was initially established by radioimmunoassay (r.i.a.) with an antibody raised to A alpha (1-21). We now provide independent confirmation of the formation of A alpha (1-21) by fast-atom-bombardment-m.s. analysis of the fractions separated chromatographically after spiking of plasma samples with peptide labelled with [2H8]Phe at position 8. Identity of the peptides was established on the basis of their chromatographic retention time and by the distinct peaks in the mass spectra of these fractions. The relative intensities of the molecular ions of natural and labelled peptides were measured. On the basis of a comparison of the peaks of similar intensities, the concentration of the natural peptide at the time of spiking was close (79%) to the amount obtained by r.i.a. An additional peptide, des-alanyl-A alpha (2-21), was also seen. The total amount of material measured by r.i.a. could be accounted for by the sum of these two provides. The addition of label and assay by m.s. has provided an independent physical-chemical method for identifying A alpha (1-21) as a characteristic product of PMN elastase release in whole blood, but which is absent in freshly drawn blood.

Direct current shock ablation: quantitative assessment of proarrhythmic effects

Catheter ablation using direct current (DC) shock has proved invaluable in the management of a variety of tachycardias. However, sporadic reports of fatal arrhythmias following ablation have raised the question of the proarrhythmic potential of DC shock ablation. The present study was undertaken in 45 patients to assess prospectively any proarrhythmia related to DC shock ablation, using matched pre- and postablation Holter monitors and programmed electrical stimulation (PES). Nineteen of these patients had Holter monitors for three successive postablation days to observe trends. There was unmatched data in 11 additional patients. All 56 patients provided prospective follow-up for clinical events. There was no immediate sustained VT/VF at the time of the ablation. Four patients had sustained VT in the first 72 hours after ablation; three episodes were similar to the preablation clinical arrhythmias; one patient had torsades de pointes interrupting bradycardia. Twelve patients met Holter, PES, or clinical criteria for proarrhythmia; none were treated on the basis of these findings. On Holter monitoring, there were significant increases in VPCs/hour and couplets/hour in patients undergoing atrial or atrioventricular junctional ablations; and an increase in couplets after accessory pathway ablations. Increases in these categories were not significant for VT patients; nor were increases in episodes of VT/hour or atrial arrhythmias significant in any group. Patients were followed for 44 +/- 33 months, with an actuarial survival of 95% at 1 year, 88% at 3 years, and 85% at 4 years. There were six deaths during follow-up. Two patients had sudden death: one at 2 months had early evidence of proarrhythmia; the other at 32 months may have represented later myocardia deterioration. One patient died of heart failure at 77 months; and there were three noncardiac deaths. DC shock ablation in humans is much less proarrhythmic than in dogs. The low incidence of clinical proarrhythmic events during prolonged follow-up after discharge resulted in low sensitivity, specificity, and positive predictive values for Holter and PES, although the negative predictive values of these tests were greater than 90%. Only one of 12 patients who met criteria for proarrhythmia in the days immediately following ablation had subsequent clinical events consistent with proarrhythmia. These results may be useful as standards for comparison with results of radiofrequency or other ablation modalities.

Structure of human neutrophil elastase in complex with a peptide chloromethyl ketone inhibitor at 1.84-A resolution

Human neutrophil elastase (HNE) has been implicated as a major contributor to tissue destruction in various disease states, including emphysema. The structure of HNE, at neutral pH, in complex with methoxysuccinyl-Ala-Ala-Pro-Ala chloromethyl ketone (MSACK), has been solved and refined to an R factor of 16.4% at 1.84-A resolution. Results are consistent with the currently accepted mechanism of peptide chloromethyl ketone inhibition of serine proteases, in that MSACK cross-links the catalytic residues His-57 and Ser-195. The structure of the HNE-MSACK complex is compared with that of porcine pancreatic elastase in complex with L-647,957, a beta-lactam inhibitor of both elastases. The distribution of positively charged residues on HNE is highly asymmetric and may play a role in its specific association with the underlying negatively charged proteoglycan matrix of the neutrophil granules in which the enzyme is stored.

Crystallization of human neutrophil elastase

Human neutrophil elastase was inactivated by methoxysuccinyl-L-Ala-L-Ala-L-Pro-L-Ala-chloromethane. The modified enzyme was crystallized from 40 mM ammonium phosphate, pH 7.0 in the hexagonal space group P6(3) with unit cell parameters a = 74.53 A, b = 74.53 A, c = 70.88 A, alpha = beta = 90 degrees, gamma = 120 degrees. These crystals were resistant to radiation damage and diffracted beyond 1.84-A resolution. The asymmetric unit contained one 25,000-dalton monomer of human neutrophil elastase. Crystals were also grown from the enzyme modified with the analogous iodinated inactivator, p-iodoanilinosuccinyl-L-Ala-L-Ala-L-Pro-L-Ala-chloromethane. These crystals proved to be isomorphous with those of methoxysuccinyl-L-Ala-L-Ala-L-Pro-L-Ala-chloromethane-modified human neutrophil elastase, and served as a single-site, heavy atom derivative for solving the tertiary structure of the enzyme.

Crystallographic study of a beta-lactam inhibitor complex with elastase at 1.84 A resolution

The continuing discovery and development of beta-lactams as antibiotics has had an unparalleled impact on the overall health and well-being of society. Recently, appropriately substituted cephalosporins were shown to be potent inhibitors of elastase, suggesting a novel therapeutic role for the beta-lactams in the control of emphysema and other degenerative diseases. We have now solved and partially refined at atomic resolution the structure of a complex of porcine pancreatic elastase with the time-dependent irreversible inhibitor 3-acetoxymethyl-7-alpha-chloro-3-cephem-4-carboxylate-1,1-dioxide tert-butyl ester (I), the most potent of the beta-lactam elastase inhibitors yet reported. (Porcine pancreatic elastase is a close relative of the desired drug target, human polymorphonuclear leukocyte elastase.) A mechanism of action is presented, based on the structure and on biochemical evidence (T.-Y.L. et al., in preparation), which clarifies the operational similarities and differences between beta-lactam elastase inhibitors and antibiotics. Features of the reaction include the expulsion of a leaving group at the cephalosporin 3' position and the formation of two covalent bonds with the active site of porcine pancreatic elastase at residues Ser 195 and His 57.

Pig pancreatic anhydro-elastase. Role of the serine-195 hydroxy group in the binding of inhibitors and substrate

The binding constants of a number of ligands were measured for pancreatic elastase (PE) and anhydro-elastase (AE) in order to assess the contribution of Ser-195 to substrate and inhibitor binding by PE. AE was purified by affinity chromatography on a column containing immobilized turkey ovomucoid inhibitor. The AE had 0.1 +/- 0.1% of the activity of the native enzyme and contained 0.8 +/- 0.06 residue of dehydroalanine per molecule. A difference electron-density map, derived from an X-ray crystallographic analysis of AE, showed that the modified residue was Ser-195. The complexing of 3-carboxypropionyl-Ala-Ala-Ala-p-nitroanilide (SAN) to the active site of AE was also demonstrated by X-ray-diffraction analysis of an AE crystal soaked overnight with substrate. The nitroanilide moiety was not observed in the difference map. AE was shown to bind turkey ovomucoid inhibitor with a dissociation constant (Kd) of 0.3 +/- 0.06 microM compared with 0.10 microM for PE. The Kd of the AE-SAN complex (0.2 mM) was comparable with the Michaelis constant for SAN with PE (1.0 mM). A number of inhibitors, such as elastatinal, which forms a hemiketal adduct with PE, while others such as the beta-lactams, which function as acylators of the active-site serine residue, bound AE with a lower affinity than to PE. The binding of a peptidylchloromethane (acetyl-Ala-Ala-Pro-Ala-CH2Cl) to AE occurs without evidence for alkylation of histidine. The binding constants for benzoisothiazolinone and 3,4-dichloroisocoumarin to PE differed from their binding constants to AE by less than a factor of 4.0-fold. The contribution of the hydroxy group of Ser-195 to the binding of these inhibitors to PE in their non-covalent complexes is relatively small, even though they inactivate PE by an acylation mechanism. These results suggest that the hydroxy group on Ser-195 in PE is of secondary importance in the energetics of ligand binding, in contrast with its essential role in the catalytic properties of the enzyme.

Human polymorphonuclear leukocyte collagenase and gelatinase. Comparison of certain enzymatic properties

Collagenase and gelatinase of human PMN leukocytes were separated by serial chromatography. The enzymes were shown to be similar in latency, activatability, chromatographic and electrophoretic behavior and the response to inhibitors. They recognize the same peptide linkage for cleavage, only each with a distinct difference in the effect caused by the secondary binding sites of the substrate molecules.

Inhibition of immune aggregate-induced activation of the first complement component by cationic polypeptides

A cationic amino acid copolymer (CP530) with a molar ratio of lysine, leucine, tryptophan and phenylalanine of 11:2:1:1 and a Mr of about 2300 was prepared and its inhibitory effects on the complement cascade was compared with those of polylysine with a Mr of about 3000. The effects by these two cationic peptides appeared to be at the early stage of complement activation. CP530 and polylysine inhibited the binding of C1q to insoluble IgG aggregates with a concentration required for 50% inhibition of 0.7 and 0.9 mM, respectively. Both compounds were also potent inhibitors of immune hemolysis (a concentration causing 50% inhibition, 0.5 and 3.5 microM respectively) as well as assembly of EAC cell intermediates required for formation of C3 and C5 convertases (a concentration of 50% inhibition of 1.0 microM for CP530 and 3.8 microM for polylysine). However, CP530 was shown to be distinctly more effective against the activation of C1r . Cls complex induced by insoluble IgG aggregate-bound C1q, requiring 0.15 mM for 50% inhibition compared to greater than 10 mM for polylysine. The 50% inhibition value for soluble IgG aggregate-induced activation of C1 in whole serum was 0.7 mM for CP530 and 5.0 mM for polylysine. The greater inhibition of C1 activation by CP530 than that exerted by polylysine could be attributable to the presence of non-lysyl residues which provide the structural basis for specificity and potency.

Effects of hyperglycemia, tolbutamide and glucagon on the pathways of glucose oxidation in the goosefish islet in vitro

The contribution of the pentose and Krebs cycles to glucose metabolism has been determined in the isolated goosefish islet, in vitro, using glucose-2-C-14. Hyperglycemia caused increased net glucose metabolism by both the pentose and Krebs cycles, while glucagon and tolbutamide had no significant effect on net glucose metabolism by either pathway. The rate of reduced pyridine nucleotide formation was calculated and was increased with hyperglycemia but not with tolbutamide or glucagon.

Studies on the existence of a pathway in liver and muscle for the conversion of glucose into glycogen without glucose 6-phosphate as an intermediate

Mixtures of (14)C-labelled glucose plus pyruvate were incubated either with rat diaphragm or slices of rat liver. Incorporation of glucose carbon into glycogen was compared with its incorporation into glucose 6-phosphate relative to the incorporation of pyruvate carbon into these metabolic products. There was no preferential incorporation of glucose carbon relative to pyruvate carbon into glycogen compared with glucose 6-phosphate in the liver slices, but there was in diaphragm. On the assumption that glucose 6-phosphate is a necessary intermediate in the conversion of pyruvate carbon into glycogen, this is evidence for the existence in muscle, but not in liver, of more than one pool of glucose 6-phosphate or of a pathway from glucose to glycogen without glucose 6-phosphate as an intermediate. Galactose carbon, relative to pyruvate carbon, was preferentially incorporated into liver glycogen, so that a substrate converted in liver into glycogen without glucose 6-phosphate as an intermediate could be detected by this approach.