Predictors and moderators of the response of adults with intellectual disabilities and depression to behavioural activation and guided self-help therapies

BACKGROUND

No previous studies have reported predictors and moderators of outcome of psychological therapies for depression experienced by adults with intellectual disabilities (IDs). We investigated baseline variables as outcome predictors and moderators based on a randomised controlled trial where behavioural activation was compared with guided self-help.

METHODS

This study was an exploratory secondary data analysis of data collected during a randomised clinical trial. Participants (n = 161) were randomised to behavioural activation or guided self-help and followed up for 12 months. Pre-treatment variables were included if they have previously been shown to be associated with an increased risk of having depression in adults with IDs or have been reported as a potential predictor or moderator of outcome of treatment for depression with psychological therapies. The primary outcome measure, the Glasgow Depression Scale for Adults with Learning Disabilities (GDS-LD), was used as the dependant variable in mixed effects regression analyses testing for predictors and moderators of outcome, with baseline GDS-LD, treatment group, study centre and antidepressant use as fixed effects, and therapist as a random effect.

RESULTS

Higher baseline anxiety (mean difference in outcome associated with a 1 point increase in anxiety 0.164, 95% confidence interval [CI] 0.031, 0.297; P = 0.016), lower performance intelligence quotient (IQ) (mean difference in outcome associated with a 1 point increase in IQ 0.145, 95% CI 0.009, 0.280; P = 0.037) and hearing impairment (mean difference 3.449, 95% CI 0.466, 6.432; P = 0.024) were predictors of poorer outcomes, whilst greater severity of depressive symptoms at baseline (mean difference in outcome associated with 1 point increase in depression -0.160, 95% CI -0.806, -0.414; P < 0.001), higher expectation of change (mean difference in outcome associated with a 1 point increase in expectation of change -1.013, 95% CI -1.711, -0.314; p 0.005) and greater percentage of therapy sessions attended (mean difference in outcome with 1 point increase in percentage of sessions attended -0.058, 95% CI -0.099, -0.016; P = 0.007) were predictors of more positive outcomes for treatment after adjusting for randomised group allocation. The final model included severity of depressive and anxiety symptoms, lower WASI performance IQ subscale, hearing impairment, higher expectation of change and percentage of therapy sessions attended and explained 35.3% of the variance in the total GDS-LD score at 12 months (R2  = 0.353, F4, 128  = 17.24, P < 0.001). There is no evidence that baseline variables had a moderating effect on outcome for treatment with behavioural activation or guided self-help.

CONCLUSIONS

Our results suggest that baseline variables may be useful predictors of outcomes of psychological therapies for adults with IDs. Further research is required to examine the value of these potential predictors. However, our findings suggest that therapists consider how baseline variables may enable them to tailor their therapeutic approach when using psychological therapies to treat depression experienced by adults with IDs.

Assessment of Anticoagulant Initiation in Patients With New-Onset Atrial Fibrillation During Emergency Department Visit-Point-by-Point Response

Patients with atrial fibrillation (AF) have an increased risk of stroke and systemic thromboembolism. Diagnosis of AF is commonly encountered in the emergency department (ED). The purpose of this study was to assess the number of patients with new-onset AF appropriately initiated on oral anticoagulation (AC) during their ED encounter. This retrospective analysis included patients discharged from the ED from July 2016 to July 2021 with a new diagnosis of AF. Patients were excluded if they were on AC before admission. The major endpoint was to identify the percentage of patients discharged from the ED without initiating AC. Minor endpoints included the average CHA2DS2-VASc scores and the reason for not initiating AC. A total of 380 patients were included in the final analysis. Of the 245 patients found to be indicated for AC, only 131 patients (53.5%) were initiated on AC and 114 patients (46.5%) were discharged without initiating AC. Almost half of the patients who presented to the ED with a new diagnosis of AF and indicated for AC were discharged without AC.

Evaluation of Patient Characteristics Linked to Major Bleeding Events in Patients Prescribed Direct Oral Anticoagulants

INTRODUCTION

Direct oral anticoagulants (DOACs) demonstrated similar efficacy and lower risk of intracranial hemorrhage than warfarin in patients with atrial fibrillation and venous thromboembolism. Given the lack of data identifying risk factors in patients who bled while on a DOAC, we sought to investigate these characteristics.

MATERIALS AND METHODS

This retrospective chart review was approved by the Mass General Brigham Institutional Review Board and assessed patients who experienced bleeding events while on DOAC therapy from 6/1/2015 to 7/1/2020. Patient characteristics were evaluated, including age, sex, body mass index (BMI), renal function, concomitant therapies, and baseline comorbidities.

RESULTS

Eighty-seven patients were included for analysis, with a median age of 75.8 years. Most patients were female (51.7%) and 24 (27.6%) had a BMI >30. At time-of-event, 21 patients (24.1%) had acute kidney injury. Thirty-three patients (37.9%) were on concomitant antiplatelet therapy (APT), with 31 (35.6%) on single APT and 2 on dual APT. Pertinent comorbidities included hypertension (74.7%), ischemic cerebrovascular accident (28.7%), thyroid abnormality (23.0%), active cancer (14.9%), and anemia (13.8%). Eleven patients (12.6%) had a prior bleeding event. Most patients were on apixaban (69.0%) for the indication of stroke prevention in nonvalvular atrial fibrillation/flutter (72.4%). FDA-approved dosing was used in most patients (92.0%), and all deviations reflected underdosing. Most bleeding events were defined as major (95.4%), occurred at a critical organ site (72.4%), and developed spontaneously (58.6%).

CONCLUSIONS

These data provide insight into characteristics of patients who experience bleeding events while on DOAC therapy. Understanding these potential risk factors may optimize the safe use of these agents.

Comparison of anticoagulated versus non-anticoagulated patients with intra-aortic balloon pumps

Background

There is limited guidance regarding the use of anticoagulation in patients on intra-aortic balloon pumps (IABP). The purpose of this study is to compare the safety outcomes in anticoagulated versus non-anticoagulated patients with an IABP.

Methods

This was a single center, retrospective chart review of patients admitted to the coronary care unit or cardiac surgery unit who received an IABP from May 2015 to July 2018. Patients who were anticoagulated with heparin while on an IABP were compared to those who were not anticoagulated. Major endpoints included a composite of thrombotic events and a composite of bleeding events. The major composite endpoint of thrombotic events included the incidence of ischemic stroke, any venous thromboembolism, device thrombosis, and limb ischemia. The major composite endpoint of bleeding events included major access site bleeding, minor access site bleeding, major non-access site bleeding, and minor non-access site bleeding. Minor endpoints included any major endpoint events occurring within 24 and 48 h of IABP insertion, hospital length of stay, intensive care unit length of stay, and in-hospital mortality.

Results

A total of 185 patients were evaluated for inclusion and 147 were included in the final analysis. There were 82 and 65 patients in the heparin and non-heparin groups, respectively. The composite endpoint of thrombotic events occurred in 7.3 and 7.7% in the heparin and non-heparin groups, respectively (p = 1). The composite bleeding endpoint occurred in 20.7 and 20.0% in the heparin and non-heparin groups, respectively (p = 0.91). There were no differences found in minor endpoints between groups.

Conclusion

There were no significant differences found in major endpoints of bleeding and thrombotic events in patients who received anticoagulation while on an IABP versus those who did not receive anticoagulation.

Feasibility of Virtual Optimization of Guideline Directed Medical Therapy in Hospitalized Patients with HFrEF During the Covid-19 Pandemic: The IMPLEMENT-HF Pilot Study

Introduction

Implementation of GDMT for HFrEF remains low. We assessed the feasibility of a virtual GDMT Team for optimization of GDMT during hospitalization for non-CV conditions.

Hypothesis

A GDMT Team will improve GDMT optimization compared with usual care.

Methods

Consecutive hospitalized patients with HFrEF≤40% were prospectively identified. Patients with critical illness, cardiology consult, de-novo HF, COVID-19 & SBP ≤90mmHg were excluded. February 3 to March 1, 2020 served as a pre-intervention period during which patients were screened, but did not receive GDMT Team interventions. From March 2 to June 21, 2020, a pharmacist-physician team provided up to 1 suggestion daily for GDMT optimization (evidence-based ß-blockers, ACEi/ARB/ARNI, & MRA) to treating teams based on an evidence-based algorithm.

The primary outcome of a composite GDMT optimization score, the net of positive therapeutic changes (+1 for new initiations/uptitrations) & negative therapeutic changes (-1 for discontinuations/downtitrations) during hospitalization, was compared between the pre- vs. post-intervention periods. Multivariable linear regression models were built adjusting associations for clinical factors. Safety outcomes requiring intervention or GDMT downtitration were identified.

Results

Of 187 encounters, 84 (45%) met eligibility criteria: 28 pre-intervention, 56 post-intervention. Mean age was 68±11 yrs, 70% men, and 61% White. Of 88 GDMT Team suggestions, 49 (56%) were followed by discharge. During the intervention, cumulative COVID-19 hospitalizations rose from 0 to 11085 in MA.

Mean GDMT optimization score was -0.14 (95% CI: -0.58 to +0.30) pre-intervention & +0.64 (95% CI: +0.35 to +0.93) post-intervention (P=0.004). In a model inclusive of demographics, comorbidities, vital signs, potassium levels, eGFR, & LVEF, the intervention was the only factor associated with higher GDMT optimization score (β coeff 0.89; P=0.008). Safety events included 1 instance each of AKI, hyperkalemia, bradycardia, & hypotension.

Conclusion

Admission for non-CV conditions is a feasible setting for GDMT optimization. A virtual GDMT Team was associated with improved GDMT; this implementation strategy warrants testing in a prospective RCT.

Assessment of Sotalol and Dofetilide Dosing at a Large Academic Medical Center

BACKGROUND

Patients initiated on sotalol and dofetilide require inpatient monitoring and dose adjustments due to risks of corrected QT (QTc) prolongation and Torsades de pointes (TdP). Patients may receive higher initial doses than recommended due to close monitoring by specialized practitioners. The objective of this study was to describe prescribing practices of sotalol and dofetilide and to compare safety outcomes between standard and nonstandard dosing strategies.

METHODS

This was a single-center retrospective analysis of adult inpatients who underwent sotalol or dofetilide initiation between June 1, 2015, and August 1, 2018. The end points of this study included the percentage of patients who received standard and nonstandard dosing, incidence of QTc prolongation (≥500 milliseconds or ≥15% from baseline), incidence of TdP, and dose reduction or medication discontinuation.

RESULTS

A total of 379 patients (195 sotalol and 184 dofetilide) were included in this analysis. There were 110 (56.4%) patients in the sotalol group and 111 (58.4%) patients in the dofetilide group that received nonstandard initial dosing. Nonstandard dosing was associated with a greater incidence of QTc prolongation compared to standard dosing (57.5% vs 43.0%, P = .005). Only one patient in the nonstandard dosing group experienced TdP. Patients initiated on nonstandard dosing required dose reduction or therapy discontinuation (37.6% vs 23.4%, P = .003) more frequently.

CONCLUSION

Higher than recommended initial doses of sotalol or dofetilide were associated with higher incidence of QTc prolongation and more frequent therapy modification.

Development of a stochastic agent-based model to evaluate surveillance strategies for detection of emergent porcine reproductive and respiratory syndrome strains

Background

The objective of the current study was to develop a stochastic agent-based model using empirical data from Ontario (Canada) swine sites in order to evaluate different surveillance strategies for detection of emerging porcine reproductive and respiratory syndrome virus (PRRSV) strains at the regional level. Four strategies were evaluated, including (i) random sampling of fixed numbers of swine sites monthly; (ii) risk-based sampling of fixed numbers, specifically of breeding sites (high-consequence sites); (iii) risk-based sampling of fixed numbers of low biosecurity sites (high-risk); and (iv) risk-based sampling of breeding sites that are characterized as low biosecurity sites (high-risk/high-consequence). The model simulated transmission of a hypothetical emerging PRRSV strain between swine sites through three important industry networks (production system, truck and feed networks) while considering sites’ underlying immunity due to past or recent exposure to heterologous PRRSV strains, as well as demographic, geographic and biosecurity-related PRRS risk factors. Outcomes of interest included surveillance system sensitivity and time to detection of the three first cases over a period of approximately three years.

Results

Surveillance system sensitivities were low and time to detection of three first cases was long across all examined scenarios.

Conclusion

Traditional modes of implementing high-risk and high-consequence risk-based surveillance based on site’s static characteristics do not appear to substantially improve surveillance system sensitivity. Novel strategies need to be developed and considered for rapid detection of this and other emerging swine infectious diseases. None of the four strategies compared herein appeared optimal for early detection of an emerging PPRSV strain at the regional level considering model assumptions, the underlying population of interest, and absence of other forms of surveillance.

Variations in all Cause and Cardiovascular Mortality by Country of Birth in Scotland, 1997-2003

Background and Aims

Country of birth provides a proxy for ethnic group for recent migrants. Major differences in mortality by country of birth have been demonstrated in England and Wales, but similar published data for Scotland are lacking. We aimed to examine variations in mortality by country of birth for Scottish residents.

Methods

We calculated standardised mortality ratios by country of birth for Scottish residents aged 25 years and over between January 1997 and March 2003.

Results and Conclusion

Comparisons with England and Wales showed high allcause, coronary heart disease (CHD) and stroke mortality among Scottish residents born in Scotland, Northern Ireland, the Republic of Ireland, India and Hong Kong. However, most country of birth groups had similar or lower mortality than the Scottish born. These are the first data on mortality by country of birth in Scotland and they demonstrate major variations. Comparisons within the Scottish population might be interpreted as reassuring, since they do not show the excesses in CHD mortality by country of birth reported in England and Wales. However, the use of England and Wales as a comparison group shows a substantial excess of CHD risk among South Asians in Scotland, comparable to that reported in England and Wales.

Breast Cancer in the Bahamas in 2009-2011

BACKGROUND

Breast cancer is the most common form of cancer affecting women in the Bahamas, which consists of many islands. This is the first attempt to identify which island has the highest occurrence of breast cancer.

OBJECTIVE

The aim of this study was to describe the sociodemographical and spatial features of breast cancer in the Bahamas in 2009-2011.

METHODS

A review of the medical records of all women with a confirmed diagnosis of breast cancer during the period January 1, 2009-December 31, 2011, was undertaken. Data were first obtained from the National Oncology Board of the Bahamas and validated by a review of the medical records. The patient address was geocoded and mapped using ArcGIS 10.0 Environmental Systems Research Institute (ESRI) to satellite images obtained from The Nature Conservancy in the Bahamas.

RESULTS

We recruited 270 patients who satisfied the entry criteria. The cumulative incidences of breast cancer for the years 2009-2011 were 51.4, 45.4, and 51.4, respectively. Breast cancer occurred most often in women of African origin with a mean age at diagnosis of 56.6 ± 13.8 years. Ductal carcinoma was the most common histological type observed with most cancers occurring in Grade II or higher and presenting as late stage (≥ Stage II). Surgery was the preferred method of treatment with modified radical mastectomy being the procedure of choice. Spatial distribution of cases across the Bahamas revealed one cluster, which is present on the island of New Providence. Further analysis of New Providence showed a consistently skewed kernel density in the central and eastern regions, compared with a scattered distribution in the southern and western regions.

CONCLUSION

The island of New Providence had the highest occurrence of breast cancer among all the islands of the Bahamas. The increasing incidence of breast cancer in young women is likely to impose a significant burden on the future of Bahamian health care.

Feasibility and acceptability of web-based enhanced relapse prevention for bipolar disorder (ERPonline): trial protocol

BACKGROUND

Relapse prevention interventions for Bipolar Disorder are effective but implementation in routine clinical services is poor. Web-based approaches offer a way to offer easily accessible access to evidence based interventions at low cost, and have been shown to be effective for other mood disorders.

METHODS/DESIGN

This protocol describes the development and feasibility testing of the ERPonline web-based intervention using a single blind randomised controlled trial. Data will include the extent to which the site was used, detailed feedback from users about their experiences of the site, reported benefits and costs to mental health and wellbeing of users, and costs and savings to health services. We will gain an estimate of the likely effect size of ERPonline on a range of important outcomes including mood, functioning, quality of life and recovery. We will explore potential mechanisms of change, giving us a greater understanding of the underlying processes of change, and consequently how the site could be made more effective. We will be able to determine rates of recruitment and retention, and identify what factors could improve these rates.

DISCUSSION

The findings will be used to improve the site in accordance with user needs, and inform the design of a large scale evaluation of the clinical and cost effectiveness of ERPonline. They will further contribute to the growing evidence base for web-based interventions designed to support people with mental health problems.

Bluetongue surveillance methods in the United States of America

Historical surveillance for bluetongue virus (BTV) exposure in the United States of America (USA) has relied on periodical serological surveillance using samples collected from cattle at slaughter. Most of this surveillance has been focused on the north-eastern portion of the USA due to the lack of competent vectors of BTV in this region. For most of the states tested in this region, the prevalence of seropositive animals has been less than 2%. Recently, a study was conducted in north-central USA using sentinel cattle herds. Results of serological testing showed an increasing gradient of exposure from north to south. In addition, detection of Culicoides sonorensis showed a similar gradient with detection in the northern areas being relatively rare. The results of these studies indicate that cattle herds in the northern and north-eastern areas of the USA are likely to be free of BTV.

Isolated lesser trochanter fractures in elderly--a case for prophylactic DHS fixation. A case series

Isolated lesser trochanter fractures are a rare presentation of hip fractures in the elderly. Classically, lesser trochanter fractures in adults are associated with tumours and result from little or no trauma. We present three elderly osteoporotic ladies who sustained isolated fractures of the lesser trochanter secondary to a definite history of trauma. Radiologically, none of them showed any evidence of pathological lesions or intertrochanteric fracture at presentation. Two patients subsequently developed displaced intertrochanteric fractures, which necessitated internal fixation. In the third patient, a dynamic hip screw (DHS) was inserted before mobilisation. Based on this experience, we recommend careful observation and follow-up of such cases and suggest that isolated lesser trochanteric fractures in the elderly osteoporotic population may be an indication for prophylactic DHS fixation.

Parents' consent to the post-mortem removal and retention of organs

Parents of children who died following complex heart surgery have recently discovered that organs were removed and retained in post-mortem investigations to which they consented. It has been established that many of these parents did not give informed consent to the retention of organs. The Bristol Royal Infirmary Inquiry which examined these practices drafted codes of practice to govern future post-mortem activities. It is argued that these codes of practice may be onerous to some parents, yet effectively disbar them from dissenting to their application whilst they might otherwise agree to the post-mortem removal and retention of organs for purposes of medical audit, research or training. This consequence arises from employing an over-rigorous concept of informed consent in the immediate circumstances of bereavement. That concept is discussed in detail. An alternative proposal is canvassed which improves on the status quo but does not impose a practice of consent which may be burdensome and distressing to many.

The value of the axial view in assessing calcaneal fractures

We studied the value of the axial view of the calcaneum in diagnosing fractures. Fifty sets calcaneal radiographs were studied by four senior trauma staff and four orthopeadic trainees on two occasions 2-3 weeks apart. On the first occasion only the lateral view was studied; on the second, both lateral and axial views were studied. The axial view did not improve the sensitivity or specificity of the lateral view alone. Senior staff were more accurate in assessing the radiographs. We suggest that the axial view should not be used routinely in assessing a patient with a possible calcaneal fracture.

Antitumor efficacy of a novel class of non-thiol-containing peptidomimetic inhibitors of farnesyltransferase and geranylgeranyltransferase I: combination therapy with the cytotoxic agents cisplatin, Taxol, and gemcitabine

Ras malignant transformation requires posttranslational modification by farnesyltransferase (FTase). Here we report on the design and antitumor activity, in monotherapy as well as in combination therapy with cytotoxic agents, of a novel class of non-thiol-containing peptidomimetic inhibitors of FTase and the closely related family member geranylgeranyltransferase I (GGTase I). The non-thiol-containing FTI-2148 is highly selective for FTase (IC50, 1.4 nM) over GGTase I (IC50, 1700 nM), whereas GGTI-2154 is highly selective for GGTase I (21 nM) over FTase (IC50, 5600 nM). In whole cells, the corresponding methylester prodrug FTI-2153 is >3000-fold more potent at inhibiting H-Ras (IC50, 10 nM) than Rap1A processing, whereas GGTI-2166 is over 100-fold more selective at inhibiting Rap1A (IC50, 300 nM) over H-Ras processing. Furthermore, FTI-2153 was highly effective at suppressing oncogenic H-Ras constitutive activation of mitogen-activated protein kinase and human tumor growth in soft agar. FTI-2148 suppressed the growth of the human lung adenocarcinoma A-549 cells in nude mice by 33, 67, and 91% in a dose-dependent manner. Combination therapy of FTI-2148 with either cisplatin, gemcitabine, or Taxol resulted in a greater antitumor efficacy than monotherapy. GGTI-2154 in similar antitumor efficacy experiments is less potent than FTI-2148 and inhibits tumor growth by 9, 27, and 46%. Combination therapy of GGTI-2154 with cisplatin, gemcitabine, or Taxol is also more effective. Finally, FTI-2148 and GGTI-2154 are 30- and 33-fold more selective and 30- and 16-fold more potent in whole cells than our previously reported thiol-containing FTI-276 and GGTI-297, respectively. Thus, our results demonstrate that this highly potent and selective novel class of non-thiol-containing peptidomimetics inhibits human tumor growth in whole animals and that combination therapy with cytotoxic agents is more beneficial than monotherapy.

Increased sialylation of oligosaccharides on IgG paraproteins--a potential new tumour marker in multiple myeloma

AIMS

To investigate whether changes in carbohydrate structure of IgG are related to malignancy and stage of disease in myeloma and monoclonal gammopathy of uncertain significance (MGUS).

METHODS

61 patients were studied at diagnosis: 14 with MGUS, nine with stage I multiple myeloma, 11 with stage II, 21 with stage III, and five with solitary plasmacytoma. IgG was extracted from serum by protein G affinity chromatography. Oligosaccharides were cleaved from the protein backbone enzymatically by N-glycosidase F. Oligosaccharide analysis was performed by high pressure anion exchange chromatography with pulsed electrochemical detection (HPAE-PED).

RESULTS

Up to 15 oligosaccharide peaks were identified in three major fractions: neutral, monosialylated, and disialylated. Patients with myeloma showed an increase in the proportion of sialylated oligosaccharides in comparison with patients with MGUS. The ratio of neutral to sialylated oligosaccharides (N:S) was reduced at all stages of myeloma compared with MGUS: MGUS, 11.35; myeloma stage I, 7.6 (p = 0.047); stage II, 5.20 (p = 0.035); stage III, 3.60 (p = 0.0002); plasmacytoma, 7.5 (p = 0.046). The N:S ratio was independent of paraprotein concentration (r = 0.05).

CONCLUSIONS

The ratio of neutral to sialylated oligosaccharides may act as a new marker of malignancy in IgG paraproteinaemia and warrants further investigation.

Seroprevalence of Babesia equi among horses in Israel using competitive inhibition ELISA and IFA assays

Sera from 361 horses were tested by indirect immunofluorescence antibody test (IFA) and by competitive inhibition ELISA (cELISA), to detect antibodies to Babesia equi. The concordance between the assays was 95.7%. Application of a cutoff based on a calculated percent inhibition of < 20% gave a total of 22 discrepant results, while only 8 sera negative by the cELISA were found positive by the IFA when a cutoff of > 20% inhibition was used. Approximately one-third of all the horses tested were found serologically positive to B. equi, with more horses testing positive from northern Israel. Among horses raised with access to pasture there was a significant difference in the percentage of seropositive reactors (76.6% in the north and 20.1% in the central region), compared with horses without access to pasture (14.3 and 10.3%, respectively). Nineteen percent of stallions were found to be positive, which was significantly less than the proportions of seropositive mares and geldings: 38 and 42%, respectively. No significant association was found between the mean age of horses and seroreactivity to B. equi.

Antibody against an Anaplasma marginale MSP5 epitope common to tick and erythrocyte stages identifies persistently infected cattle

A protein epitope of major surface protein 5 (MSP5), defined by monoclonal antibody (MAb) ANAF16C1, is conserved among Anaplasma species (E. S. Visser, T. C. McGuire, G. H. Palmer, W. C. Davis, V. Shkap, E. Pipano, and D. P. Knowles, Jr., Infect. Immun. 60:5139-5144, 1992) and is expressed in the salivary glands of infected ticks. A competitive inhibition ELISA (cELISA) for the detection of bovine anti-MSP5 antibodies was developed by using purified recombinant MSP5 fusion protein and MAb ANAF16C1. The specificity of the recombinant-MSP5 cELISA within North America was established by using 261 serum samples from cattle in the regions of Hawaii and Northern Ontario where anaplasmosis is not endemic and from cattle proven by splenectomy or subinoculation of whole blood into susceptible splenectomized recipients to be uninfected. The maximum percent inhibition by these sera was 18%. Sera known to be positive were obtained from 35 cattle either experimentally inoculated with infected erythrocytes or exposed to infected Dermacentor andersoni ticks. Thirty-four of the 35 serum samples inhibited MAb ANAF16C1 binding by > or = 25%. During acute infection, the MSP5 cELISA detected antibodies prior to or concomitantly with the appearance of rickettsiae in erythrocytes. Antibodies were detectable in sera from persistently infected cattle inoculated as long as 6 years previously.

Fragmentation of the ribosome to investigate RNA-ligand interactions

RNA molecules perform a variety of important and diverse functions and, therefore, an understanding of their structure and interaction with proteins and ligands is essential. Large RNA molecules (for example, the ribosomal RNAs) are complex and hence reports describing their fragmentation into functional subdomains has provided a means for their detailed analysis. We present here an in vivo approach to study RNA-ligand interactions. This is based on the concept that an RNA fragment could mimic a drug-binding site present on the intact molecule. Overexpression of the fragment would sequester the drug thereby permitting the continued functioning of the ribosome and, thus, ensuring cell viability. Accordingly, a fragment of 16S rRNA encompassing the spectinomycin-binding domain in helix 34 (nucleotides 1046-1065 and 1191-1211) was cloned and in vivo expression resulted in drug resistance. Furthermore, an RNA fragment lacking flanking sequences to helix 34 was also selected from among a pool of random rRNA fragments and shown to confer spectinomycin resistance. A similar in vitro approach is also described for the analysis of rRNA molecules that interact with the yeast elongation factor 3 (EF-3).

Occurrence of the regulatory nucleotides ppGpp and pppGpp following induction of the stringent response in staphylococci

The stringent response in Escherichia coli and many other organisms is regulated by the nucleotides ppGpp and pppGpp. We show here for the first time that at least six staphylococcal species also synthesize ppGpp and pppGpp upon induction of the stringent response by mupirocin. Spots corresponding to ppGpp and pppGpp on thin-layer chromatograms suggest that pppGpp is the principal regulatory nucleotide synthesized by staphylococci in response to mupirocin, rather than ppGpp as in E. coli.

Clinical risk management

Managing clinical risk involves all staff with clinical and managerial responsibilities. This article draws attention to some key steps in risk management and ways to deal with the problems when things do go wrong.

Rapid identification of metallo- and serine beta-lactamases

Simple methods to detect, identify, and differentiate metallo- and serine beta-lactamases were developed and used to differentiate enzymes produced by 17 clinical isolates of Xanthomonas maltophilia. All isolates exhibited beta-lactamase activity, and in 16 strains this was induced by imipenem. All but one isolate hydrolyzed imipenem (and meropenem), and in all cases this activity was inhibited by 1 mM EDTA. The metallo- and serine beta-lactamases in the cell extracts were distinguished on isoelectric focusing (IEF) gels by using the following procedures. (i) Cell lysates were preincubated with 83 mM EDTA prior to IEF and subsequent visualization with nitrocefin, and (ii) after IEF, the gels were overlaid with either 1 mM zinc sulfate or 100 microM BRL 42715 before staining with nitrocefin. Bands of beta-lactamase activity which were removed by BRL 42715 but unaffected by EDTA or zinc sulfate were categorized as serine beta-lactamases. Bands which were unaffected by BRL 42715 but inhibited by EDTA or enhanced by zinc sulfate were classified as metallo-beta-lactamases. By using this approach, seven metallo-beta-lactamases were differentiated with pI values of 4.8 (two strains), 5.5 (four strains), 5.7 (one strain), 6.0 (one strain), 6.4 (four strains), 6.6 (one strain), and 6.8 (three strains). The metallo-beta-lactamase band with a pI of 6.4 aligned with the recently characterized metallo-beta-lactamase from X. maltophilia 511. Heterogeneity was also observed for the serine beta-lactamases: 14 isolates elaborated serine beta-lactamase activity which focused with major bands with at least eight different pIs. The remaining three strains produced serine beta-lactamases which focused with five distinct bands with pIs of 6.4, 6.2, 5.7, 5.5, and 5.2. We conclude that X. maltophilia produces many types of metallo- and serine beta-lactamases distinguishable by these new methods and that the previously reported L-1 and L-2 enzymes are not solely representative of the beta-lactamases produced by this species.

Managing the new NHS: breathing new life into the NHS reforms

The essence of the NHS reforms is that they bring market forces to bear on organisations providing public services, while allowing those organisations more freedom to respond in ways that will improve the efficiency, effectiveness, and appropriateness of their services. The new structural changes to the NHS--a leaner management executive and fewer, slimmer regions--could be used either to strengthen these features of the reforms or frustrate them by allowing ministers and top management to intervene even more at local level and "overmanage" the market. To ensure that the aims of the reforms are not frustrated ministers and the management executive must restrict themselves to laying down clear strategies and then allow purchasers and providers to meet those strategies in their own ways. They also need to ensure that the whole NHS can learn and benefit from local experimentation and devise ways of managing the crises that will inevitably arise; otherwise they might be tempted to become involved in managing the market at too local a level, and the NHS will suffer the worst of both worlds: stifling bureaucracy at the top and parochial self interest locally.

Advice to a Moscow children's hospital

At the request of the largest children's hospital in Moscow, McKenzie and colleagues made recommendations for improving the service. Restrictions on visiting and fears of contracting illness from non-disposable needles have discouraged the local population from using the hospital. Consequently the hospital is underused and overstaffed. Serious shortages of drugs and surgical supplies compromise care. Fundamental changes are needed in nursing and postgraduate education. The authors encouraged their Russian colleagues to address the health care needs of their local population and to develop family centred care, and they offered training in London.

Amyotrophic lateral sclerosis and lymphoma: bone marrow examination and other diagnostic tests

In a prospective study of patients with different forms of motor neuron disease, we performed bone marrow biopsy to evaluate the possibility that the patient might have an otherwise asymptomatic lymphoma. By the time 37 patients had been studied, two patients had been found to have lymphoma, one with and one without paraproteinemia.

Molecular basis for membrane rigidity of hereditary ovalocytosis. A novel mechanism involving the cytoplasmic domain of band 3

Hereditary ovalocytic red cells are characterized by a marked increase in membrane rigidity and resistance to invasion by malarial parasites. The underlying molecular defect in ovalocytes remained a mystery until Liu and colleagues (N. Engl. J. Med. 1990. 323:1530-38) made the surprising observation that the ovalocytic phenotype was linked to a structural polymorphism in band 3, the anion transporter. We have now defined the mutation in band 3 gene and established the biophysical sequelae of this mutation. This mutation involves the deletion of amino-acids 400-408 in the boundary between the cytoplasmic and the first transmembrane domains of band 3. The biophysical consequences of this mutation are a marked decrease in lateral mobility of band 3 and an increase in membrane rigidity. Based on these findings, we propose the following model for increased membrane rigidity. The mutation induces a conformational change in the cytoplasmic domain of band 3, leading to its entanglement in the skeletal protein network. This entanglement inhibits the normal unwinding and stretching of the spectrin tetramers necessary for membrane extension, leading to increased rigidity. These findings imply that the cytoplasmic domain of an integral membrane protein can have profound effects on membrane material behavior.

Severity of arthritis is predicted by antibody response to gp135 in chronic infection with caprine arthritis-encephalitis virus

Antibody titers to caprine arthritis-encephalitis virus surface glycoprotein gp135 and core protein p28 in synovial fluid and serum from 35 goats infected for 3 years were compared with the histologic severity of arthritis in these animals. Anti-gp135 antibody titers in synovial fluid and serum directly reflect the severity of carpal arthritis in chronically infected goats.

Persistent infection of rabbits with bovine leukemia virus associated with development of immune dysfunction

Bovine leukemia virus (BLV) infection of rabbits provides a safe and relatively inexpensive in vivo mammalian system for the study of the mechanisms controlling expression of a unique group of lymphotropic retroviruses. This group of viruses, which includes C-type human T-lymphotropic virus types I and II and lentiviruslike human immunodeficiency virus type 1, possesses genes coding for "trans-activating" products. Rabbits experimentally inoculated with BLV became persistently infected, as demonstrated by a number of tests. All BLV-inoculated rabbits developed persistent serum antibody to BLV. Furthermore, all BLV-inoculated rabbits had peripheral blood mononuclear cells which, when stimulated, expressed the virus, as demonstrated by viral induction of syncytium formation in a BLV-susceptible fibroblast line. The presence of BLV in circulating cells was confirmed by using peripheral blood mononuclear cells from randomly selected BLV-inoculated rabbits, which showed the presence of viral reverse transcriptase activity, BLV transcriptional activity, or BLV proviral DNA. Additional tests showed that infected lymphocytes maintained in culture with recombinant human interleukin-2 formed multinucleated giant cells and produced virus when incubated in cytokine-containing medium. BLV-infected rabbits also showed alterations in several parameters associated with immunity, beginning 6 months after inoculation. Thirty-eight percent of infected rabbits developed abnormally low T-cell responses, as measured by phytolectin stimulation, and T-cell responses cycled between normal and abnormally low over a period of 20 to 24 months. Forty-four percent of rabbits infected for longer than 12 months suffered from recurrent conjunctivitis and rhinitis. By 24 months postinoculation, 28% of infected rabbits were dead or were killed because of poor clinical condition.

Using DRGs in developing referral policies for coronary care within a local health district

This paper presents the results of a study into some specific aspects of the management of coronary heart disease within one district health authority. In particular, it is concerned with the appropriate balance of inpatient coronary care between the district general hospital and community hospitals in the light of current and potential changes in the clinical management of coronary cases. The study is an example of a multidisciplinary approach to local health planning which is beginning to emerge within the Exeter Health District, the methodology of which may be applicable to client groups within the medical specialties other than coronary cases, such as strokes or respiratory disorders. It also illustrates the use of spatial analysis and diagnosis-related groups in local planning.

Detection of Anaplasma-marginale-infected tick vectors by using a cloned DNA probe

Anaplasmosis is the most widely distributed of several important tick-borne diseases that constrain cattle production throughout much of the world. Evaluation of the effectiveness of disease control strategies that integrate vaccination with tick control requires the ability to monitor tick and cattle infection rates. To detect Anaplasma marginale in ticks and bovine erythrocytes, a 2-kilobase DNA fragment from a cloned A. marginale gene coding for a surface protein having a Mr of 105,000 was prepared and evaluated as a probe. The probe was species specific and detected A. marginale DNA derived from infected bovine erythrocytes and adult Dermacentor ticks infected either as nymphs or adults. Tick infection was confirmed by microscopy and test feeding on a susceptible calf. The sensitivity of the probe is suitable for detecting infected ticks in experimental and field epizootiology studies.

In vivo responses to Mycobacterium leprae: antigen presentation, interleukin-2 production, and immune cell phenotypes in naturally occurring leprosy lesions

To investigate the immune defect in lepromatous leprosy we studied immune cell phenotypes, lymphocyte activation states, and interleukin-2 (IL-2) production in naturally occurring leprosy skin lesions. Mouse hybridoma monoclonal antibodies reacting with the IL-2 receptor (anti-Tac), unbound IL-2 (DMS-1), antigen-presenting Langerhans' cells (OKT6) and the OKT4-Leu3 and OKT8 T-lymphocyte subpopulations were used with indirect horseradish peroxidase and alkaline phosphatase techniques on frozen biopsy sections. The percentage of Tac+ lymphocytes and the number of OKT6+ cells in the epidermis and dermal granuloma were significantly correlated in naturally occurring lesions (correlation coefficient 0.79) and were higher in tuberculoid than in lepromatous lesions. Leu3 antigen was expressed by 70-90% of Tac+ cells in tuberculoid lesions. Although the percentage of cells producing IL-2 was low in lesions of both lepromatous and tuberculoid patients, it was about 15 times greater in tuberculoid than in lepromatous lesions (0.032 +/- 0.037 tuberculoid vs 0.0019 +/- 0.023 lepromatous). There was an association between the number of OKT6+ cells and the percentage of IL-2-producing cells, but the association was weaker than that of OKT6+ cells and the percentage of IL-2 receptor-bearing cells (r = 0.2), implying that IL-2 production is not an intervening variable in the latter association. The absolute number of OKT4-Leu3+ lymphocytes was significantly different in different clinical leprosy groups and was positively correlated with host resistance (mean OKT4-Leu3+ cells/mm2 in 6 micron sections; 1412 +/- 288 tuberculoid, 400 +/- 93 borderline lepromatous, 200 +/- 100 polar lepromatous; r = 0.95). Absolute numbers of OKT8+ cells/mm2 in lesions were not significantly different. We conclude that there is a relative paucity of OKT4-Leu3+ cells as well as IL-2-producing cells at the local level in lepromatous leprosy lesions. Possible functional relationships between these findings and the failure of macrophage activation and destruction of Mycobacterium leprae in lepromatous leprosy are discussed.

Monoclonal antibodies to E92, an endothelial cell surface antigen

Two hybridoma-derived monoclonal antibodies have been developed that react with an antigen of molecular weight 92,000 daltons on the surface of human endothelial cells. Cultured human umbilical vein endothelial cells were used for immunization, but the antigen is present on arterial, venous and capillary endothelium, as determined by biotin-avidin immunoperoxidase staining of tissue sections. With this technique, other cell types in the tissues which were examined were not reactive, except for scattered fibroblasts and histiomonocytic cells, trophoblastic cells of the placenta, and benign immature mesenchymal cells in a renal cystadenocarcinoma. By cytofluorography, the antibodies were found to be unreactive with granulocytes, T lymphocytes, B lymphocytes, and the majority of monocytes. Fibroblasts were reactive with the antibodies, but the fluorescence tracings indicated a lower density of antigen on these cells than on endothelial cells. Immunoreactivity of fibroblasts could be decreased by treatment of the cells with thrombin, trypsin, or neuraminidase, whereas these enzymes did not affect the immunoreactivity of endothelial cells. The reactive antigen (E92) does not appear to be any of several previously described endothelial cell proteins, because of its molecular weight and its absence on other cell types. The presence of E92 on trophoblastic cells of the placenta and immature mesenchymal cells, as well as fibroblasts and endothelial cells, may indicate that it is a primitive antigen of mesodermal tissue that is lost by most cell types during differentiation.