Characterization of prolyl iminopeptidase-deficient Neisseria gonorrhoeae

Prolyl iminopeptidase (PIP) is an enzyme produced by Neisseria gonorrhoeae, the detection of which is incorporated into several commercial test panels. In this report we describe two distinct mutations in the pip gene which account for the loss of PIP activity.

Endovascular embolization of a traumatic arteriovenous fistula of the superficial temporal artery

Arteriovenous fistula of the superficial temporal artery is a rare condition most commonly caused by trauma. Traditional surgical treatment has been superseded by endovascular embolization. We present the case of a 40 year-old man with a traumatic arteriovenous fistula of the superficial temporal artery who was treated by endovascular embolization. The advantages of this approach are discussed, along with a brief history of the condition.

Determination of the Electron-Antineutrino Angular Correlation Coefficient a0 in Unpolarized Neutron β-Decay

The coefficient a 0 has been derived from a measurement of the integral spectrum of recoil protons stored in a quasi-Penning trap with inhomogeneous magnetic field and adiabatic focusing onto an electro-static mirror of potential variable in 10 V steps between 0 V and 850 V. Correction for incomplete transfer of energy from transverse to longitudinal degrees of freedom, and the violation of the adiabatic conditions on reflection at the mirror, is carried out by alternately measuring the spectrum at trapping times of 1 ms and 2 ms. The results a 0 = -0.1054 ± 0.0055 and |λ | = 1.271 ± 0.018 are comparable in precision with existing measurements of a 0.

Proposed Measurement of the Beta-Neutrino Correlation in Neutron Decay

Currently, the beta-neutrino asymmetry has the largest uncertainty (4 %) of the neutron decay angular correlations. Without requiring polarimetry this decay parameter can be used to measure λ (ga/gv ), test Cabibbo-Kobayashi-Maskawa (CKM) unitarity limit scalar and tensor currents, and search for Charged Vector Current (CVC) violation. We propose to measure the beta-neutrino asymmetry coeffcient, a, using time-of-flight for the recoil protons. We hope to achieve a systematic uncertainty of σa / a ≈ 1.0 %. After tests at Indiana University's Low Energy Neutron Source (LENS), the apparatus will be moved to the National Institute of Standards and Technology (NIST) where the measurement can achieve a statistical uncertainty of 1 % to 2 % in about 200 beam days.

Search for Radiative β-Decay of the Free Neutron

Results of the first experiment to search for the radiative decay mode of the free neutron are reported. The γ-spectrum was studied in the energy region from 35 keV to 100 keV in six Cs(Tl) scintillators, each set at an angle of 35° to, and shielded from, a central plastic scintillator electron detector. Triple coincidences were recorded with recoil protons detected in a micro-channel plate. A limit for the branching ratio BR < 6.9 × 10(-3) (90 % confidence level) was obtained, which is greater that the theoretical prediction by not more than a few tenths of a percent.

Detecting the Radiative Decay Mode of the Neutron

Beta decay of the neutron into a proton, electron, and electron antineutrino is occasionally accompanied by the emission of a photon. Despite decades of detailed experimental studies of neutron beta-decay, this rare branch of a fundamental weak decay has never been observed. An experiment to study the radiative beta-decay of the neutron is currently being developed for the NG-6 fundamental physics endstation at the National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR). The experiment will make use of the existing apparatus for the NIST proton-trap lifetime experiment, which can provide substantial background reduction by providing an electron-proton coincidence trigger. Tests and design of a detector for gamma-rays in the 10 keV to 200 keV range are under development. The need for a large solid-angle gamma-ray detector that can operate in a strong magnetic field and at low temperature has led us to consider scintillating crystals in conjunction with avalanche photodiodes. The motivation and experimental technique will be discussed.

Thoracofemoral bypass using spliced femoral vein with removal of an infected axillobifemoral bypass graft

A 63-year-old male underwent emergency repair of a ruptured juxtarenal aortic aneurysm via a transabdominal approach using an aorto-bi-iliac Dacron graft. This became infected. A right axillobifemoral bypass was placed and the infected graft was removed with oversewing of the aorta. The patient was re-admitted 8 months later with an infected axillobifemoral prosthesis. We harvested both femoral veins (FV) and spliced them to perform a left thoracobifemoral bypass with simultaneous explantation of the infected graft. The patient remains well with a patent graft 20 months post-operatively.

52 NUCLEAR REMODELING AFTER SOMATIC CELL NUCLEAR TRANSFER (SCNT) IN THE RHESUS MONKEY

Successful reprogramming of somatic cell nuclei after nuclear transfer requires active remodeling by factors present in the nonactivated cytoplast. High levels of maturation promoting factor (MPF) activity are associated with this remodeling process which includes nuclear envelope breakdown (NEBD), premature chromosome condensation (PCC), and spindle formation. MPF degradation, caused by fertilization or artificial activation, is in turn required for pronuclear formation and subsequent embryonic cleavage, and involves cyclin B catalyzed proteolysis by the proteasome system. In the rhesus monkey, SCNT results in the production of cleaving embryos, but development arrests at the morula stage presumably because of abnormal or incomplete reprogramming. We undertook this pilot study to examine the timing and extent of nuclear remodeling events (NEBD, PCC) in monkey SCNT embryos. The proteasome inhibitor MG-132 was employed to avoid or delay premature MPF degradation (Zhou et al. 2003 Science 302, 1179). Monkey fetal fibroblasts employed as nuclear donor cells were fused with nonactivated cytoplasts and incubated in the presence (n = 20) or absence (control; n = 35) of MG-132. Embryos were fixed and co-labeled with DAPI (DNA) and monoclonal antibody against lamin A/C (nuclear envelope). In monkey germinal vesicle-stage oocytes (n = 5) and zygotes (n = 6), a lamin A/C signal was detected at the nuclear periphery while matured MI (n = 6) and MII (n = 12) oocytes were negative for lamin A/C staining, consistent with the absence of a nuclear membrane. Donor fetal fibroblasts arrested at the G1 stage of the cell cycle exhibited a lamin A/C signal. Minimal or no changes were observed in donor nuclei within 1 h after fusion. The majority of control SCNT embryos sampled 4 h after fusion exhibited only slight chromatin condensation; however, they failed to form metaphase chromosomes. Positive lamin A/C staining indicated the presence of intact nuclear membranes. Following activation these SCNT embryos cleaved, but arrested at the 8–16 cell stage. In initial experimentation we determined the minimal efficient concentration of MG-132 to be 5 μM, that is capable of inhibiting first polar body extrusion during the MI–MII transition. Subsequent in vitro development to the blastocyst stage (53%) of fertilized oocytes treated with 5 μM MG-132 for up to 4 h was similar to that of nontreated controls. Incubation of SCNT embryos (n = 20) for 4 h with MG-132 resulted in robust chromosome condensation, spindle formation, and weak or partial lamin A/C signal. Our observations suggest that incomplete nuclear remodeling events in monkey SCNT embryos may be due to premature MPF inactivation perhaps caused by the fusion pulse. Future studies will address the developmental potential of monkey SCNT embryos exposed to MG-132. This work was supported by NIH grant NS04330, Core Grant RR00163 and a product donation from Ares Advanced Technology, Inc.

Bacterial pathogens in rural water supplies in Southern Alberta, Canada

Raw river and irrigation water in the Oldman River Basin in southern Alberta was tested for the presence of two bacterial pathogens, Escherichia coli O157:H7 and Salmonella spp., over the last 2 yr (2000-2001). The number of E. coli O157:H7 and Salmonella spp. isolated from raw water peaked during the summer months. While E. coli O157:H7 was only isolated from 11/802 (1.35%) of raw water samples over the entire sampling season in 2000 and from 16/806 (2.05%) of the samples in 2001, the pathogen was isolated one or more times from 10/35 (28.55%) sampling sites in 2000 and from 13/40 (32.55%) sampling sites in 2001. Salmonella was isolated from 44/802 (5.55%) of raw water samples in 2000 and from 122/822 (14.95%) of the samples in 2001; the pathogen was isolated one or more times from 25/35 (71.45%) sampling sites in 2000 and from 29/40 (72.55%) sampling sites in 2001. Certain sites had multiple pathogen isolations in the same year and from year to year. Salmonella Rublislaw was the most common Salmonella serovar isolated in both years, accounting for 52.45% of isolates.

A generalized extension to the Hounsell–Wilkinson head scatter model

Hounsell and Wilkinson (1997 Phys. Med. Biol. 42 1737-49) have demonstrated that the concept of a scatter-plane source can accurately describe head scatter in irregularly shaped fields produced by the MLC of an Elekta linear accelerator. In these linacs, the solid jaw is below the MLC set and plays no part on defining the view of the main source of head scatter, the flattening filter. A more complicated situation arises for linear accelerator head designs which incorporate a solid upper jaw pair with the MLC jaws further from the source. Application of the Hounsell and Wilkinson technique to these accelerator designs does not achieve the accuracy in the Elekta application. We present a generalized extension to Hounsell and Wilkinson's model and present results for typical treatment field shapes on a Siemens Primus linear accelerator.

Folic acid knowledge and use among relatives in Irish families with neural tube defects: an intervention study

BACKGROUND

Relatives in families where a child has a neural tube defect (NTD) may be at higher risk of having an affected child. Little is known of their level of knowledge and use of folic acid.

AIM

To carry out an intervention study intended to increase knowledge and use of folic acid among relatives.

METHODS

One hundred aunts and female first cousins (relatives of the proband) were interviewed by telephone before and after receiving an information pack.

RESULTS

At baseline, although knowledge of the benefits of folic acid was high (73%), use of folic acid was low (8.8%). After the intervention, knowledge increased and use went up to 19% (p < 0.05).

CONCLUSIONS

This study suggests that relatives in Irish NTD families have a high level of information about folic acid benefits. This awareness may not translate into action since the intervention produced only a modest increase in folic acid use overall. Future studies focussing on women who are planning a pregnancy may show larger benefits from intervention.

Delirium

Delirium is a common cause of mortality and morbidity in older people in hospital, and indicates severe illness in younger patients. Identification of risk factors, education of professional carers, and a systematic approach to management can improve the outcome of the syndrome. Physicians should be aware that delirium sufferers often have an awareness of their experience, which may be belied by their varying grasp of reality.

Response to imatinib in patients who relapse after allogeneic stem cell transplantation for chronic myeloid leukemia

We studied 128 patients with chronic myeloid leukemia (CML) relapsing after allogeneic stem cell transplantation (SCT). Disease at the time of treatment with Imatinib was in chronic phase (CP) in 51 patients, accelerated phase (AP) in 31 and blastic crisis (BC) in 46. Of the 51 patients in CP, 14 were in cytogenetic and two in molecular relapses. The median interval between relapse and Imatinib therapy was 5 months (0-65). A total of 50 patients had failed treatment with donor lymphocyte infusions prior to Imatinib. The overall hemato-logical response rate was 84% (98% for patients relapsing in CP). The complete cytogenetic response (CCR) was 58% for patients in CP, 48% for AP and 22% for patients in BC. Complete molecular responses were obtained in 25 patients (26%), of whom 21 were in CP or AP. With a median follow-up of 9 months, the estimated 2-year survival for CP, AP and BC patients was 100, 86 and 12%, respectively. Out of 79 evaluable patients, 45 (57%) achieved full donor and 11 (14%) mixed chimerism after Imatinib. We conclude that Imatinib has significant activity against CML in relapse after allogeneic SCT. Durable cytogenetic and molecular remissions are obtainable in patients in CP.

Prevalence of Escherichia coli O157:H7 and Salmonella spp. in surface waters of southern Alberta and its relation to manure sources

The Oldman River watershed in southern Alberta, Canada, is an extensively irrigated region in which intensive agricultural practices have flourished. Concern over water quality in the basin has been expressed because of high levels of enteric disease indigenous to the region. To address these concerns, we conducted a 2-year study to estimate the prevalence of Escherichia coli O157:H7 and Salmonella spp. in surface water within the basin. This study is the first of its kind to identify E. coli O157:H7 repeatedly in surface water collected from a Canadian watershed. Prevalence of E. coli O157:H7 and Salmonella spp. in water samples was 0.9% (n = 1,483) and 6.2% (n = 1,429), respectively. While data examined at a regional level show a relationship between high livestock density and high pathogen levels in southern Alberta, statistical analysis of point source data indicates that predicted manure output from bovine, swine, and poultry feeding operations was not directly associated with either Salmonella spp. or E. coli O157:H7 prevalence. However, geography and weather variables, which are likely to influence bacterial runoff, were not considered in this model. We also postulate that variations in time, amount, and frequency of manure application onto agricultural lands may have influenced levels of surface-water contamination with these bacterial pathogens.

Outcome of 112 consecutive patients with an abdominal aortic aneurysm greater than 5·5 cm turned down for elective repair at a university hospital

Background

The UK Small Aneurysm study has demonstrated the low risk of rupture in aneurysms less than 5·5 cm in diameter. However, the natural history of aneurysms greater than 5·5 cm remains unresolved. Questions of equipoise probably preclude another trial in patients with an AAA over 5·5 cm. In this centre, the authors prospectively maintain records of all patients refused elective aneurysm surgery. This study aimed to document the outcome of all patients referred with an AAA greater than 5·5 cm in diameter, and to determine the cause of death and risk of rupture in all patients.

Methods

Details of all patients presenting with an AAA from 1989 to 1999 were recorded and demographic details on all patients with an AAA greater than 5·5 cm were collected. The endpoint was 1 May 1999. Copies of death certificates for deceased patients were obtained from the Office of National Statistics, local in-hospital patient records and general practitioner records. Results of post-mortem examinations were also retrieved. Aneurysms were stratified according to size at presentation (5·5–5·9, 6·0–7·0, more than 7·0 cm) and reasons for non-intervention were documented.

Results

Some 112 patients were turned down over 10 years (11·4 per year). The mean(s.d.) age of this patient group was 77·7(7·7) years; there were 74 men and 38 women. Crude mortality data are shown in the Fig. below (Kaplan–Meier curve). At the end of the study period, 87 patients (76 per cent) were dead, 26 (30 per cent) from a ruptured AAA. Mean survival times were: 23 months (5·5–5·9 cm), 20 months (6·0–7·0 cm) and 15 months (greater than 7·0 cm).

Conclusion

While recognizing the problems with death certification, rupture still seems to be a significant cause of death in patients with untreated AAAs greater than 5·5 cm. While little difference is observed in 5·5–7·0-cm range, patients with an AAA greater than 7·0 cm seem to have a much poorer prognosis.

Allogeneic stem-cell transplantation for lymphoproliferative disorders using BEAM-CAMPATH (+/- fludarabine) conditioning combined with post-transplant donor-lymphocyte infusion

BACKGROUND

We report our updated experience of allogeneic transplantation in lympho-proliferative disorders using a reduced-intensity conditioning regimen combining BEAM (plus fludarabine in three cases) with pre-transplant CAMPATH. Post-transplant donor lymphocytes have been infused for persisting disease or relapse, and both chimerism and minimal residual disease have been monitored utilizing molecular techniques.

METHODS

Thirty patients with median age 47.6 years underwent allogeneic transplantation for relapsed or high-risk lymphoproliferative disease using HLA-identical (sibling n = 25, unrelated n = 2) or one antigen mismatched sibling donors (n = 3). Twenty-one had NHL, three had HD and six had CLL/PLL. Stem-cell source was PBSC (n = 24), BM (n = 5) or both (n = 1) with a median CD34 dose of 4.5 x 10(6)/kg. GvHD prophylaxis was with CYA and MTX.

RESULTS

Engraftment was prompt in the majority of patients, with a median of 15 days to both ANC > 0.5 and platelets > 20. There have been three transplant-related deaths secondary to viral pneumonitis or bacterial pneumonia. Seven patients developed Grade I-II acute GvHD post-transplant. Of 28 evaluable patients, 18 achieved a CR at assessment 2-3 months post-transplant and a further patient converted from PR to CR following DLI, to give an overall CR rate of 68%. Three patients had early progressive disease and six have relapsed from CR or progressed from PR (two of whom have achieved CR following DLI therapy). Overall survival is 67% and event-free survival 48% at 3 years. With a median follow-up of 1.3 years 57% of patients are currently alive and lymphoma-free. A molecular remission has been achieved in nine of 12 informative patients.

DISCUSSION

These encouraging results show that this reduced-intensity conditioning regimen is effective, with a low-toxicity profile compared with conventional TBI-based conditioning, and certainly merits further evaluation in this setting.