VRE acquisition in hospital and its association with hospital antimicrobial usage -a non-linear analysis of an extended time series

BACKGROUND

Vancomycin resistant enterococci (VRE) have become endemic pathogens in many Australian hospitals causing significant morbidity. There are few observational studies that have evaluated the effect of antibiotic usage on VRE acquisition. This study examined VRE acquisition and its association with antimicrobial use. The setting was a NSW tertiary hospital with 800 beds over a 63 month period up to March 2020, straddling piperacillin-tazobactam (PT) shortages that occurred from in September 2017.

METHODS

The primary outcome was monthly inpatient hospital onset Vancomycin-resistant Enterococci (VRE) acquisitions. Multivariate adaptive regression splines (MARS) were used to estimate hypothetical thresholds, where antimicrobial use above threshold is associated with increased incidence of hospital onset VRE acquisition. Specific antimicrobials and categorised usage (broad, less broad and narrow spectrum) were modelled.

RESULTS

There were 846 hospital onset VRE detections over the study period. Hospital onset vanB and vanA VRE acquisitions fell significantly by 64% and 36% respectively after the PT shortage. MARS modelling indicated that PT usage was the only antibiotic found to exhibit a meaningful threshold. PT usage greater than 17.4 defined daily doses/1000 occupied bed-days (95%C I: 13.4, 20.5) was associated with higher onset of hospital VRE.

CONCLUSIONS

This paper highlights the large, sustained impact that reduced broad spectrum antimicrobial use had on VRE acquisition and showed that PT use in particular was a major driver with a relatively low threshold. It raises the question as to whether hospitals should be determining local antimicrobial usage targets based on direct evidence from local data analysed with non-linear methods.

A study protocol for improving the delivery of acute kidney replacement therapy (KRT) to critically ill patients in Alberta – DIALYZING WISELY

Background

Acute kidney replacement therapy (KRT) is delivered to acutely ill patients to support organ function and life in the Intensive Care Unit (ICU). Implementing standardized acute KRT pathways can ensure its safe and effective management. At present, there is no standardized approach to the management of acute KRT in Alberta ICUs.

Methods

Dialyzing Wisely is a registry embedded, stepped-wedge, interrupted time-series evaluation of the implementation of a standardized, stakeholder-informed, and evidence-based acute KRT pathway into Alberta ICUs. The acute KRT pathway will consist of two distinct phases. First, we will implement routine monitoring of evidence-informed key performance indicators (KPIs) of acute KRT. Second, we will provide prescriber and program reports for acute KRT initiation patterns. After the implementation of both phases of the pathway, we will evaluate acute KRT performance quarterly and implement a customized suite of interventions aimed at improving performance. We will compare this with baseline and evaluate iterative post implementation effects of the care pathway.

Discussion

Dialyzing Wisely will implement, monitor, and report a suite of KPIs of acute KRT, coupled with a care pathway that will transform the quality of acute KRT across ICUs in Alberta. This program will provide a framework for scaling evidence-informed approaches to monitoring and management of acute KRT in other jurisdictions. We anticipate improvements in acute KRT performance, decreased healthcare system costs and improved patient quality of life by decreasing patient dependence on maintenance dialysis.

Trial registration

Clinicaltrials.gov, NCT05186636. Registered 11, January, 2022.

Improving the quality of the performance and delivery of continuous renal replacement therapy (CRRT) to critically ill patients across a healthcare system: QUALITY CRRT: a study protocol

INTRODUCTION

Continuous renal replacement therapy (CRRT) is a continuous form of dialysis used to support critically ill patients with acute kidney injury. The ideal delivery of CRRT requires ongoing monitoring and reporting to adjust practice and deliver optimal therapy. However, this practice occurs variably.

METHODS

QUALITY CRRT is a multicentre, prospective, stepped-wedged, interrupted time series (ITS) evaluation of the effectiveness, safety and cost of implementing a multifaceted CRRT quality assurance and improvement programme across an entire healthcare system. This study will focus on the standardisation of CRRT programmes with similar structure, process and outcome metrics by the reporting of CRRT key performance indicators (KPIs). The primary outcome will be the quarterly performance of CRRT KPIs. Secondary outcomes will include patient-centred outcomes and economic outcomes. Analysis will compare pre-implementation and post-implementation groups as well as for the performance of KPIs using an ITS methodology. The health economic evaluation will include a within-study analysis and a longer-term model-based analysis.

DISCUSSION

The effective delivery of CRRT to critically ill patients ideally requires a standardised approach of best practice assessment and ongoing audit and feedback of standardised performance measures. QUALITY CRRT will test the application of this strategy stakeholder engagement and stepped-wedged implementation across an entire healthcare system.

ETHICS AND DISSEMINATION

This study has received ethics approval. We will plan to publish the results in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04221932.

PROTOCOL VERSION

1.0 (15 June 2020).

Co-development of a transitions in care bundle for patient transitions from the intensive care unit: a mixed-methods analysis of a stakeholder consensus meeting

Background

Intensive care unit (ICU) patients undergoing transitions in care are at increased risk of adverse events and gaps in medical care. We evaluated existing patient- and family-centered transitions in care tools and identified facilitators, barriers, and implementation considerations for the application of a transitions in care bundle in critically ill adults (i.e., a collection of evidence-based patient- and family-centred tools to improve outcomes during and after transitions from the intensive care unit [ICU] to hospital ward or community).

Methods

We conducted a concurrent mixed methods (quan + QUAL) study, including stakeholders with experience in ICU transitions in care (i.e., patient/family partners, researchers, decision-makers, providers, and other knowledge-users). First, participants scored existing transitions in care tools using the modified Appraisal of Guidelines, Research and Evaluation (AGREE-II) framework. Transitions in care tools were discussed by stakeholders and either accepted, accepted with modifications, or rejected if consensus was achieved (≥70% agreement). We summarized quantitative results using frequencies and medians. Second, we conducted a qualitative analysis of participant discussions using grounded theory principles to elicit factors influencing AGREE-II scores, and to identify barriers, facilitators, and implementation considerations for the application of a transitions in care bundle.

Results

Twenty-nine stakeholders attended. Of 18 transitions in care tools evaluated, seven (39%) tools were accepted with modifications, one (6%) tool was rejected, and consensus was not reached for ten (55%) tools. Qualitative analysis found that participants’ AGREE-II rankings were influenced by: 1) language (e.g., inclusive, balance of jargon and lay language); 2) if the tool was comprehensive (i.e., could stand alone); 3) if the tool could be individualized for each patient; 4) impact to clinical workflow; and 5) how the tool was presented (e.g., brochure, video). Participants discussed implementation considerations for a patient- and family-centered transitions in care bundle: 1) delivery (e.g., tool format and timing); 2) continuity (e.g., follow-up after ICU discharge); and 3) continuous evaluation and improvement (e.g., frequency of tool use). Participants discussed existing facilitators (e.g., collaboration and co-design) and barriers (e.g., health system capacity) that would impact application of a transitions in care bundle.

Conclusions

Findings will inform future research to develop a transitions in care bundle for transitions from the ICU, co-designed with patients, families, providers, researchers, decision-makers, and knowledge-users.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-07392-2.

1040 Evaluation of The Use of Biopatch In Haemodialysis Lines: Are We Reducing the Risk of Infection?

Aim

Children who had the central venous lines inserted for prolonged vascular access usually experience the catheter-related blood stream infection (CRBSI). CRBSI is known to be associated with high morbidity which increases the cost of the healthcare and the chances of mortality. Clinical evidence suggests that the use of biopatch (chlorhexidine-impregnated dressing) is effective in reducing the rate of infection in central venous lines. The aim of our study was to evaluate whether the use of biopatch actually reduced the CRBSI in children who had had haemodialysis lines at our institution.

Method

Theatre logs and electronic records of 46 patients who had haemodialysis lines inserted between 2015-2019 were retrospectively reviewed. These patients were randomly selected.

Results

The total number of lines inserted in 46 patients were 104. The mean of line per patient was 2.2. Out of 104 lines, 22 lines (21%) had confirmed infection.

Conclusions

Infection of the central line is still a significant problem. Infections were more prevalent in cases which did not use biopatch according to the documentation. We believe the rate of infection can be reduced by encouraging the use of biopatch on regular basis for the haemodialysis lines and the proper documentation of its use in the operation notes.

Subpolar North Atlantic western boundary density anomalies and the Meridional Overturning Circulation

Changes in the Atlantic Meridional Overturning Circulation, which have the potential to drive societally-important climate impacts, have traditionally been linked to the strength of deep water formation in the subpolar North Atlantic. Yet there is neither clear observational evidence nor agreement among models about how changes in deep water formation influence overturning. Here, we use data from a trans-basin mooring array (OSNAP-Overturning in the Subpolar North Atlantic Program) to show that winter convection during 2014-2018 in the interior basin had minimal impact on density changes in the deep western boundary currents in the subpolar basins. Contrary to previous modeling studies, we find no discernable relationship between western boundary changes and subpolar overturning variability over the observational time scales. Our results require a reconsideration of the notion of deep western boundary changes representing overturning characteristics, with implications for constraining the source of overturning variability within and downstream of the subpolar region.

Does the source of referral affect outcomes for paediatric testicular torsion?

INTRODUCTION

This single centre study retrospectively analysed the intraoperative findings relative to source of referral for emergency scrotal explorations performed in a tertiary level paediatric surgery department.

METHODS

All patients who underwent emergency scrotal exploration under the care of paediatric surgeons in our unit between April 2008 and April 2016 were identified. Clinical data were obtained from contemporaneous records.

RESULTS

Over the 8-year study period, 662 boys underwent emergency scrotal exploration: 6 (1%) were internal referrals, 294 (44%) attended our emergency department (ED) directly, 271 (41%) were referred from primary care and 91 (14%) were transferred from other hospitals. Excluding procedures in neonates, testicular torsion was present in 100 cases (15%). Testicular detorsion with bilateral 3-point testicular fixation was performed in 66 (66%) and orchidectomy with contralateral fixation in 34 (34%) where the torted testis was non-viable intraoperatively. The orchidectomy rate in the presence of torsion was 23% in ED referrals (12/52), 43% in primary care referrals (12/28) and 50% for transfers (10/20). The difference in rates between ED referrals and patients transferred from other hospitals was significant (p=0.026). There was no significant difference in median age between any of the groups (p=0.10).

CONCLUSIONS

Boys undergoing emergency scrotal exploration had a higher orchidectomy rate when transferred from other hospitals to our unit. This difference was statistically significant when compared with boys presenting directly to our ED. This supports advice from The Royal College of Surgeons of England for undertaking paediatric scrotal explorations in the presenting hospital when safe to do so rather than delaying the care of these patients by transferring them to a tertiary paediatric surgical unit.

Synchronous laparoscopic-assisted percutaneous endoscopic gastrostomy and peritoneal dialysis catheter placement is a valid alternative to open surgery

OBJECTIVE

Gastrostomy feeding is frequently necessary in children receiving chronic peritoneal dialysis (PD). Synchronous laparoscopic-assisted placement of percutaneous endoscopic gastrostomy (PEG) and PD catheter has many potential advantages. This study investigates whether this technique is comparable to open placement.

METHODS

The notes of all patients over a 16-year time period were reviewed retrospectively. Peritonitis was defined as the presence of a white blood cell count > 100/mm(3) with at least 50% being polymorphonuclear leukocytes, and infection was defined as the presence of positive peritoneal cultures with peritonitis.

RESULTS

Ten patients received primary laparoscopic-assisted PEG and PD catheter insertion (LAP) and 23 patients open gastrostomy and PD catheter (OPEN). PD catheter survival was median 12 months in the LAP group and 17 months in the OPEN group. Peritonitis and infection rates per catheter-year were 0.89 and 0.7 LAP and 0.59 and 0.5 OPEN. The risk of peritonitis and infection was not related to method of placement.

CONCLUSIONS

There were no statistically significant differences in outcomes between the two groups. We conclude that laparoscopic-assisted synchronous PD and PEG catheter insertion is safe and effective.

46XY girls: the importance of careful newborn examination

STUDY OBJECTIVE

To understand the timing and factors affecting diagnosis of phenotypically female 46XY children.

DESIGN, SETTING, AND PARTICIPANTS

We studied all phenotypically female 46XY children who attended our multidisciplinary disorders of sexual differentiation (DSD) clinic in Nottingham England in a 3-year period since its inception. Case notes from a prospectively maintained database were reviewed and data were analyzed on the age at presentation, family history, findings on genital examination, and underlying endocrine abnormality.

RESULTS

Eleven children were studied, all of whom were being raised as girls. The median age of presentation was 18 months (range birth-15 years). Although the newborn examination detected the possibility of DSD in only 3 cases; 10 of 11 children had at least one significant abnormality in their external genitalia at presentation.

CONCLUSION

Careful neonatal genital examination can identify children with DSD. However, not all children with these conditions are identified early. Early diagnosis, when possible, is important, as it has the potential to make the management of this difficult condition more straightforward.

Mapeando a imaginação feminista: da redistribuição ao reconhecimento e à representação

Este artigo realiza uma reflexão sobre como reinventar o projeto feminista em um mundo que se globaliza, a partir de um balanço sobre as mudanças no feminismo no contexto das transformações no capitalismo pós-guerra e na geopolítica pós-comunista. O pós-11 de Setembro significou uma mudança drástica nas energias feministas, deslocando a ponta-de-lança da luta de gênero dos Estados Unidos para espaços transnacionais, como a "Europa". O que está por trás dessa mudança geográfica e quais são as suas implicações políticas para o futuro do projeto feminista são questões que a autora busca responder.

Is regional anaesthesia better than general anaesthesia for caesarean section?

The Royal College of Anaesthetists have set the standard that 85% of emergency caesarean sections should be carried out under regional anaesthesia. Reducing the frequency of caesarean sections carried out under general anaesthesia may serve to reduce maternal morbidity and mortality, which has been shown over recent years. A retrospective audit was carried out at a tertiary referral centre investigating the mode of anaesthesia and fetal outcome after emergency caesarean section. The proportion carried out under regional anaesthesia was less than recommended. Despite a longer time taken to induce anaesthesia there was no increase in adverse fetal outcome, supporting the use of regional anaesthesia wherever possible to keep maternal complications to a minimum.

Appendicular colic and the non-inflamed appendix: fact or fiction?

AIMS

Appendicoliths cause acute appendicitis and appendicular perforation. Do appendicoliths cause acute abdominal pain in the absence of acute appendicitis?

METHODS

A retrospective observational study was undertaken of histology reports of all appendicectomy specimens from children < 16 years of age between January 1995 and December 2001. Specimens were categorised as perforated or uncomplicated acute appendicitis, non-inflamed, and "incidental" (removed during abdominal surgery for other indications). The presence of an appendicolith was noted. Clinical details were supplemented by selected case note review. Specimens in which the diagnosis of appendicitis or the presence of an appendicolith were not clearly defined (n = 20) were reviewed by an experienced, independent pathologist.

RESULTS

601 consecutive appendicectomy reports were analysed. The mean age of the study population was 9 years (range 1 day - 15.9 years) and there were 357 boys. An appendicolith was identified in 31/118 (26%) cases of perforated appendicitis, 60/352 (17%) cases of uncomplicated appendicitis, 12/59 (20%) cases of non-inflamed appendices, and only 1/72 (1%) cases of incidental appendicectomies. All patients with an appendicolith in the non-inflamed appendix group had presented with acute abdominal pain mimicking acute appendicitis. The frequency of an appendicolith in perforated appendicitis was significantly greater than in uncomplicated acute appendicitis (chi (2) = 4.8, 1 df, p < 0.05). There was no significant difference in the frequency of an appendicolith between non-inflamed appendices and acute appendicitis (either perforated or intact). Appendicoliths were rarely found in incidental appendicectomies, but these patients were younger. The frequency of appendicoliths in non-inflamed appendices was much greater than that expected from published autopsy data.

CONCLUSION

Appendicoliths may cause acute abdominal pain that mimics acute appendicitis.

Handlebar hernia masquerading as an inguinal haematoma

We report a child who sustained a traumatic hernia of the lower abdominal wall after being thrown forward against the handlebar of his bicycle. This is a rare injury in children, and the clinical features mimic an inguinal haematoma. Suspicion should be raised by the immediate appearance of a mass above the inguinal canal following groin injury, particularly if the swelling then disappears with the patient supine.

Heteronuclear 2D-correlations in a uniformly [13C, 15N] labeled membrane-protein complex at ultra-high magnetic fields

One- and two-dimensional solid-state NMR experiments on a uniformly labeled intrinsic membrane-protein complex at ultra-high magnetic fields are presented. Two-dimensional backbone and side-chain correlations for a [U-13C, 15N] labeled version of the LH2 light-harvesting complex indicate significant resolution at low temperatures and under Magic Angle Spinning. Tentative assignments of some of the observed correlations are presented and attributed to the alpha-helical segments of the protein, mostly found in the membrane interior.

Oral probiotics can resolve urogenital infections

We report the first clinical evidence that probiotic lactobacilli can be delivered to the vagina following oral intake. In 10 women with a history of recurrent yeast vaginitis, bacterial vaginosis (BV) and urinary tract infections, strains Lactobacillus rhamnosus GR-1 and Lactobacillus fermentum RC-14 suspended in skim milk and given twice daily for 14 days, were recovered from the vagina and identified by morphology and molecular typing within 1 week of commencement of therapy. In six cases of asymptomatic BV or intermediate BV (based upon Nugent scoring) was resolved within 1 week of therapy.

Development of a homogeneous MAP kinase reporter gene screen for the identification of agonists and antagonists at the CXCR1 chemokine receptor

Agonist activity at G protein-coupled receptors (GPCRs) that regulate heterotrimeric G proteins of the Galpha(i/o) or Galpha(q) families has been shown to result in activation of the mitogen-activated protein (MAP) kinase cascade. To facilitate compound screening for these classes of GPCR, we have developed a reporter gene that detects the activation of the ternary complex transcription factor Sap1a following MAP kinase activation. In contrast to other reporter gene assays for Galpha(i/o)-coupled GPCRs, the MAP kinase reporter generates an increase in signal in the presence of agonist. The reporter gene has been transfected into Chinese hamster ovary cells to generate a "host" reporter gene-containing cell line. The Galpha(i)-coupled human CXCR1 chemokine receptor was subsequently transfected into this cell line in order to develop a 384-well format screen for both agonists and antagonists of this receptor. Agonists activated the reporter gene with the expected rank order of potency and with similar concentration dependence as seen with the regulation of other signal transduction cascades in mammalian cells: interleukin-8 (IL-8) (pEC(50) = 7.0 +/- 0.1) > GCP-2 (pEC(50) = 6.3 +/- 0.1) > NAP-2 (pEC(50) < 6). CXCR1-mediated activation of MAP kinase was inhibited by pertussis toxin and the MEK inhibitor PD98059, demonstrating that receptor activation of MAP kinase is due to pertussis toxin-sensitive Galpha(i/o)-family G proteins to cause the activation of MEK kinase. Using the 384-well format, assay performance was unaffected by solvent concentrations of 0.5% ethanol, 0.15% glycerol, or 1% DMSO. Signal crosstalk between adjacent wells was less than 1%. The assay exhibited a Z factor of 0.53 and a coefficient of variation of response to repeated application of IL-8 (100 nM) of 15.9%.

Age-based rationing in the allocation of health care

OBJECTIVES

This article seeks to review debates about age-based rationing in health care.

METHODS

The article identifies four different levels (or types) of decision-making in health resources allocation--societal, strategic, programmatic, and clinical--and assesses how the issues of rationing vary in relation to each level.

RESULTS

The article concludes that rationing is least defensible at the clinical level, where it is also most covert. The role of rationing at other levels is more defensible when based on grounds of cost-effectiveness rather than equity. The article emphasizes the importance of fairness in health allocation and suggests that efficiency criteria need to be considered in that context.

DISCUSSION

The article suggests that rationing is most problematic where it is least overt. This raises further questions about how rationing can be made more explicit at different levels of decision making.

An RMO in Sierra Leone

We enjoyed a very low level of DNBI during our deployment and no soldier had to be returned to the UK on medical grounds. None of the measures employed to reduce disease were complicated or new and most were merely common sense. The implementation does however require firm conviction by the chain of command. As in virtually all conflicts the greatest threat to a deployed force continues to be disease.

Pharmacological characterization of human recombinant melatonin mt(1) and MT(2) receptors

We have pharmacologically characterized recombinant human mt(1) and MT(2) receptors, stably expressed in Chinese hamster ovary cells (CHO-mt(1) and CHO-MT(2)), by measurement of [(3)H]-melatonin binding and forskolin-stimulated cyclic AMP (cAMP) production. [3H]-melatonin bound to mt(1) and MT(2) receptors with pK(D) values of 9.89 and 9.56 and B(max) values of 1.20 and 0.82 pmol mg(-1) protein, respectively. Whilst most melatonin receptor agonists had similar affinities for mt(1) and MT(2) receptors, a number of putative antagonists had substantially higher affinities for MT(2) receptors, including luzindole (11 fold), GR128107 (23 fold) and 4-P-PDOT (61 fold). In both CHO-mt(1) and CHO-MT(2) cells, melatonin inhibited forskolin-stimulated accumulation of cyclic AMP in a concentration-dependent manner (pIC(50) 9.53 and 9.74, respectively) causing 83 and 64% inhibition of cyclic AMP production at 100 nM, respectively. The potencies of a range of melatonin receptor agonists were determined. At MT(2) receptors, melatonin, 2-iodomelatonin and 6-chloromelatonin were essentially equipotent, whilst at the mt(1) receptor these agonists gave the rank order of potency of 2-iodomelatonin>melatonin>6-chloromelatonin. In both CHO-mt(1) and CHO-MT(2) cells, melatonin-induced inhibition of forskolin-stimulated cyclic AMP production was antagonized in a concentration-dependent manner by the melatonin receptor antagonist luzindole, with pA(2) values of 5.75 and 7.64, respectively. Melatonin-mediated responses were abolished by pre-treatment of cells with pertussis toxin, consistent with activation of G(i)/G(o) G-proteins. This is the first report of the use of [(3)H]-melatonin for the characterization of recombinant mt(1) and MT(2) receptors. Our results demonstrate that these receptor subtypes have distinct pharmacological profiles.

Growth response to rhIGF-I 80 microg/kg twice daily in children with growth hormone insensitivity syndrome: relationship to severity of clinical phenotype

BACKGROUND

rhIGF-I has been used effectively to promote growth in growth hormone insensitivity syndrome (GHIS) in doses ranging from 40 microg/kg twice daily to 150-200 microg/kg once daily. It appears that the dose of 80 microg/kg twice daily s.c. may induce an equivalent response to higher doses with less side-effects.

OBJECTIVE

To study the efficacy and safety of rhIGF-I, 80 microg/kg twice daily s.c., in children with GHIS and to analyse the relationship of growth response to severity of phenotype.

PATIENTS AND DESIGN

Eleven prepubertal children (3 females, 8 males) with GHIS; basal GH > 2.5 microg/l, IGF-I < 50 microg/l, IGFBP-3 < - 2SD; were treated with IGF-I 80 microg/kg twice daily in a multi-centre study. The baseline characteristics of these patients were as follows (mean +/- SD): age, 7.5 +/- 2.5 years (range, 2.5-11.7 years), bone age (Tanner-Whitehouse - 2 RUS), 5.2 +/- 2.4 years (range, 2.3-9.1 years), mean height SDS, - 5.6 +/- 1.6 (range, - 3.1 to - 8.1), height velocity (HV), 3.1 +/- 1.1 cm/year (range, 1.9-4.9 cm/year). Height, HV, weight, skinfold thickness, puberty stage and bone age were measured at baseline and 6 monthly for 2 years.

RESULTS

During the first 12 months of IGF-I therapy, the mean +/- SD HV was 7.7 +/- 1.6 cm/year (range, 6.1-11.2 cm/year), the mean +/- SD increase in HV was 4.7 +/- 2.1 cm/year (range, 1.7-8.8 cm/year) and the mean +/- SD progression of bone age was 1.9 +/- 1.0 years (range, 0.8-3.8 years). Pre-treatment height SDS at the start of IGF-I therapy correlated positively with pretreatment serum IGFBP-3 SDS levels (r = 0.85; P < 0.01). There was a significant inverse correlation between gain in height SDS and pre-treatment height SDS (r = - 0.76; P < 0.01). During the 2nd 12 months of therapy, mean HV was 7.0 +/- 3.4 cm/year (range 3.8-12.4) change in height SDS from 12 to 24 months was not significantly correlated with pre-treatment height SDS. Subscapular skinfold SDS decreased significantly (P < 0.05) during the study period, whereas there was no significant change in body mass index and triceps skinfold thickness SDS. Adverse events reported in the patient group included headache (2 patients), hypoglycaemia (2 patients), papilloedema (transient, 1 patient), lipohypertrophy (5 patients) and tonsillectomy/adenoidectomy (2 patients).

CONCLUSION

This study reveals that IGF-I treatment at a dose of 80 microg/kg twice daily is effective in patients with growth hormone insensitivity syndrome. During the first 12 months of therapy, there was a significant inverse relationship between growth response to IGF-I therapy and the severity of the phenotype of growth hormone insensitivity syndrome, as measured by height SDS, at the start of therapy. Patients with a more severe clinical phenotype of growth hormone insensitivity syndrome, who also had most severe IGFBP-3 deficiency, responded better than those who were more mildly affected. An analogous situation has been shown to be the case in GH-deficient patients treated with hGH.

Calcium sensing properties of the GABA(B) receptor

The GABA(B) receptor has been shown to consist of a heterodimer of two related 7-transmembrane receptors GABAB-R1 and GABA(B)-R2. These receptors share close homology to the Ca2+-sensing receptor and also to the metabotropic glutamate receptors, which have also been shown to respond to extracellular calcium. We show here that the GABA(B) receptor also has Ca2+ sensing properties. Ca2+ (0.001-1 mM) potentiated the GABA stimulation of [35S]GTPgammaS binding in membranes prepared from CHO cells stably expressing the GABA(B)-R1/R2 heterodimer. The GABA EC50 was reduced from 72 to 7.7 microM by addition of 1 mM Ca2+, with no change in the maximum response. A similar effect was observed in membranes from rat brain cortex. Ca2+ also potentiated GABA inhibition of forskolin-stimulated cAMP levels in the CHO cells and enhanced coupling to GIRK K+ channels in Xenopus oocytes. Other divalent cations were ineffective. The effects of Ca2+ were found to be agonist dependent with baclofen having a reduced sensitivity compared to GABA. Calcium appears to act allosterically to enhance GABA responses at the GABA(B) receptor, however, unlike the Ca2+-sensing receptor and some of the mGluR family, Ca2+ does not act as a ligand in its own right.

A bioluminescent assay for agonist activity at potentially any G-protein-coupled receptor

Transient expression of apoaequorin in Chinese hamster ovary (CHO) cells and reconstitution with the co-factor coelenterazine resulted in a large, concentration-dependent agonist-mediated luminescent response following cotransfection with the endothelin ETA, angiotensin ATII, thyrotropin-releasing hormone (TRH), and neurokinin NK1 receptors, all of which interact pre-dominantly with the G alpha q-like phosphoinositidase-linked G-proteins. A substantially greater luminescence was obtained with mitochondrially targeted apoaequorin compared to cytoplasmically expressed apoaequorin. To generate a system amenable for the study of agonist activity at virtually any G-protein-coupled receptor the alpha subunit of the receptor promiscuous G-protein G alpha 16 was either transiently or stably expressed in CHO cells together with apoaequorin. In cells expressing G alpha 16, but not in its absence, agonists at a series of receptors which normally interact with either G alpha s or G alpha i were now able to cause a luminescent response from mitochondrially targeted apoaequorin. In the case of the A1 adenosine receptor, this response was clearly a result of activation of G alpha 16 and not a consequence of the release of the G alpha i-associated beta/gamma complex, as the luminescent response was unaffected by pertussis toxin treatment of the cells, whereas agonist-mediated inhibition of adenylyl cyclase activity was attenuated. These studies describe the use of coexpressed apoaequorin as a reporter for G-protein-coupled receptor-mediated calcium signaling. Furthermore, coexpression of G alpha 16 and apoaequorin provides a basis for a generic mammalian cell microplate assay for the assessment of agonist action at virtually any G-protein-coupled receptor, including orphan receptors for which the physiological signal transduction mechanism may be unknown.

A quality assurance scheme for the Kleihauer test: the Scottish experience 1988-1996

This report describes the experience gained in the last 8 years of implementing and administering a Quality Assurance Scheme dedicated to improving the reliability of Kleihauer test results in Scotland. Initially the five transfusion centres in Scotland were the only participants, but since 1992 all 15 hospital laboratories in Scotland performing the Kleihauer test to ensure an adequate dose of anti-D is administered to Rh-negative women, at risk of developing allo anti-D, have joined this voluntary scheme. As a result of the standardization of technical methods, improvement in reporting of QA results has been observed since 1994.

In vivo expression of inducible nitric oxide synthase in experimentally induced neurologic diseases

The purpose of this study was to investigate the induction of inducible nitric oxide synthase (iNOS) mRNA in the brain tissue of rats and mice under the following experimental conditions: in rats infected with borna disease virus and rabies virus, in mice infected with herpes simplex virus, and in rats after the induction of experimental allergic encephalitis. The results showed that iNOS mRNA, normally nondetectable in the brain, was present in animals after viral infection or after induction of experimental allergic encephalitis. The induction of iNOS mRNA coincided with the severity of clinical signs and in some cases with the presence of inflammatory cells in the brain. The results indicate that nitric oxide produced by cells induced by iNOS may be the toxic factor accounting for cell damage and this may open the door to approaches to the study of the pathogenesis of neurological diseases.

MK: a pluripotential embryonic stem-cell-derived neuroregulatory factor

MK is a gene encoding a secreted heparin-binding polypeptide originally isolated by differential screening for genes induced by retinoic acid (RA) in HM-1 embryonal carcinoma cells. Here we report that MK is expressed at high levels in both embryonal carcinoma and pluripotential embryonic stem cells and their differentiated derivatives. MK expression in these cell types is unaffected by the presence or absence of RA. Recombinant MK protein (rMK) was produced by transient expression in COS cells and purified by heparin affinity chromatography. rMK is a weak mitogen for 10T1/2 fibroblast cells but inactive as a mitogen for Swiss 3T3 fibroblasts. rMK is a potent mitogen for neurectodermal precursor cell types generated by treatment of 1009 EC cells with RA but has no mitogenic or neurotrophic effects on more mature 1009-derived neuronal cell types. rMK is active as an in vitro neurotrophic factor for E12 chick sympathetic neurons and its activity is markedly potentiated by binding the factor to tissue-culture plastic in the presence of heparin. Stable 10T1/2 cells lines have been established which express MK. These cells do not exhibit any overt evidence of cell transformation but extracellular matrix preparations derived from these cells are a potent source of MK biological activity. It is concluded that MK is a multifunctional neuroregulatory molecule whose biological activity depends upon association with components of the extracellular matrix.

X chromosome inactivation in fibroblasts of mentally retarded female carriers of the fragile site Xq27.3: application of the probe M27 beta to evaluate X inactivation status

Over 30% of female carriers of the fragile X [fra(X)] syndrome are clinically affected. A nonrandom X chromosome inactivation in these cases could be a plausible explanation. A review of previous studies addressing this question showed inconclusive results; thus, we analysed the X inactivation pattern in fibroblasts of 4 unrelated, mentally retarded fra(X) carriers with a high expression of the fragile site Xq27.3. Using Southern analysis with a highly polymorphic probe M27 beta that recognizes methylation differences between the active and inactive X chromosome we found a 50/50 inactivation pattern in 2 cases and skewed patterns in the other 2. As biased patterns were also observed in control females we conclude that at present no evidence exists for a nonrandom X chromosome inactivation in the fra(X) syndrome in females.

The effectiveness of bacillus Calmette-Guérin (BCG) vaccination against tuberculosis. A case-control study in Treaty Indians, Alberta, Canada

Bacillus Calmette-Guérin (BCG) vaccination against tuberculosis has been used around the world for 60 years, yet its efficacy in large, controlled prospective studies is inconsistent. The factors influencing BCG protection include variation in immunogenic potential, background exposure to environmental mycobacteria, and differences in host response to vaccine. As a means of addressing regional differences in protection, case-control studies provide a relatively inexpensive, rapid means of assessing regional vaccine effects. Treaty Indian cases (n = 160) resident in Alberta, Canada, presenting during a 5-year period (1975-1979) were individually matched for age, sex, and Band with two nontuberculous controls. A 57 percent protection by BCG vaccination was demonstrated. These results support the usefulness of case-control studies and their importance in planning tuberculosis control programs.

Molecular characterization of human X/Y translocations suggests their aetiology through aberrant exchange between homologous sequences on Xp and Yq

Several DNA sequences from two homologous regions, localized on the distal part of the human X chromosome short arm and on the long arm of the Y chromosome, have been hybridized to DNAs from seven human-rodent hybrids containing human X; Y translocation chromosomes. Molecular characterization of the translocated chromosomes has revealed, in all but one case, transfer of the Y cluster of sequences and complete deletion of the corresponding X-chromosomal sequences. The possible role of X/Y homology in the aetiology of X; Y translocations is proposed.

Linkage studies do not confirm the cytogenetic location of incontinentia pigmenti on Xp11

Linkage studies have been performed in 5 incontinentia pigmenti (IP) families totaling 29 potentially informative meioses. Ten probes of the Xp arm were used, six of them were precisely localized on the X chromosome, using hamster X human somatic cell hybrids containing a broken X chromosome derived from an incontinentia pigmenti patient carrying an X;9 translocation [46,XX,t(X;9)(p11.21;q34)]. The following order for probes is proposed: pter - (DXS7, DXS146, DXS255) - IP1 - (DXS14, DXS90) - DXS106 - qter. The negative lod scores obtained exclude the possibility that in the families studied, the gene for IP is located in Xp11 or in the major part of the Xp arm.