Propensity matched analysis examining the effect of passive reversal of direct oral anticoagulants on blood loss and the need for transfusions among traumatic geriatric hip fractures

BACKGROUND

Reversal of direct oral anticoagulants (DOACs) is currently recommended prior to emergent surgery, such as surgical intervention for traumatic geriatric hip fractures. However, reversal methods are expensive and timely, often delaying surgical intervention, which is a predictor of outcomes. The study objective was to examine the effect of DOAC reversal on blood loss and transfusions among geriatric patients with hip fractures.

METHODS

This retrospective propensity-matched study across six level I trauma centers included geriatric patients on DOACs with isolated fragility hip fractures requiring surgical intervention (2014-2017). Outcomes included: intraoperative blood loss, intraoperative pRBCs, and hospital length of stay (HLOS).

RESULTS

After matching there were 62 patients (31 reversed, 31 not reversed), 29 patients were not matched. The only reversal method utilized was passive reversal (waiting ≥ 24 hours for elimination). Passively reversed patients had a longer time to surgery (mean, 43 vs. 18 hours, p < 0.01). Most patients (92%) had blood loss (90% passively reversed, 94% not reversed); the median volume of blood loss was 100 mL for both those groups, p = 0.97. Thirteen percent had pRBCs transfused (13% passively reversed and 13% not reversed); the median volume of pRBCs transfused was 525 mL for those passively reversed and 314 mL for those not reversed, p = 0.52. The mean HLOS was significantly longer for those passively reversed (7 vs. 5 days, p = 0.001).

CONCLUSIONS

Passive DOAC reversal for geriatric patients with isolated hip fracture requiring surgery may be contributing to delayed surgery and an increased HLOS without having a significant effect on blood loss or transfusions. These data suggest that passive DOAC reversal may not be necessary prior to surgical repair of isolated hip fracture.

Development of a prediction model to determine responders to conservative treatment in people with symptomatic hand osteoarthritis: A secondary analysis of a single-centre, randomised feasibility trial

BACKGROUND

Conservative treatments are beneficial for people with hand osteoarthritis (OA).

OBJECTIVE

It was the purpose of this study to develop and internally validate both a basic model and a more complex model that could predict responders to conservative treatments in people with hand OA.

DESIGN

This was a secondary analysis of a single-centre, randomised feasibility study.

METHODS

Fifty-nine participants (34 responders) with hand osteoarthritis were recruited from the general population. Participants were randomised to receive either advice alone, or advice in combination with blood flow restriction training (BFRT), or traditional high intensity training (HIT). Participants underwent supervised hand exercises three times per week for six weeks. The OMERACT-OARSI criteria were utilised to determine responders vs non responders to treatment at the end of six weeks. A basic logistic regression model (treatment type, expectations, adherence) and a more complex logistic regression model (basic model variables plus pain catastrophising and neuropathic pain features) were created. Discrimination ability, and calibration were assessed. Internal model validation through bootstrapping (200 repetitions) was utilised to calculate the prediction model optimism.

RESULTS

The results showed that the basic model presented with acceptable discrimination (optimism corrected c-statistic: 0.72, 95% CI 0.71-0.73) and calibration (slope = 1.41; intercept = 0.68). The more complex model had better discrimination but poorer calibration.

CONCLUSION

A prediction tool was created to provide an individualised estimate of treatment response in people with hand OA. Future studies will need to validate this model in other groups of patients.

TRIAL REGISTRATION

https://www.anzctr.org.au/- ACTRN12617001270303.

Neglect-like symptoms and their relationships with other clinical features in people with hand osteoarthritis: An exploratory study

BACKGROUND

Symptomatic hand osteoarthritis (OA) is a debilitating condition. Body schema impairments such as neglect-like symptoms have been previously reported in people with symptomatic hand OA, however, little is known about their clinical importance, or relationships with other clinical features.

OBJECTIVES

The aim of this cross-sectional study was to assess the prevalence of neglect-like symptoms in painful hand OA and their association with measures of depression, pain catastrophising, sleep quality, function, pain interference and pain duration whilst controlling for important covariates.

DESIGN

Secondary analysis of cross-sectional study.

METHODS

Logistic regression with age, sex, and worst pain intensity as covariates were utilised to assess differences between participants with and without neglect-like symptoms.

RESULTS

A total of 121 participants were recruited. Sixty-one percent of participants presented with neglect-like symptoms. Participants with longer pain duration had greater odds of presenting with neglect-like symptoms (OR: 1.10 95%CI: 1.01 to 1.19; p = 0.012). No difference was observed for depression, pain catastrophising, sleep quality, function, or pain interference.

CONCLUSIONS

A large proportion of participants with symptomatic hand OA reported neglect-like symptoms, the presence of which was associated with longer pain duration.

Six weeks of resistance training (plus advice) vs advice only in hand osteoarthritis: A single-blind, randomised, controlled feasibility trial

BACKGROUND

People with hand osteoarthritis (OA) may benefit from resistance training interventions. To date the feasibility of a such interventions for symptomatic hand OA, as per international guidelines, is unknown.

OBJECTIVE

Determine the feasibility of a clinical trial comparing resistance training to an advice only control group in people with symptomatic hand OA.

DESIGN

Single-blind, randomised, controlled feasibility study.

METHODS

The American College of Rheumatology criteria for hand OA were utilised for inclusion. Participants were randomly allocated (1:1:1) to advice and blood flow restriction training (BFRT), advice and traditional high intensity training (HIT), or advice only (control). Participants receiving BFRT and HIT underwent supervised hand exercises three times a week for six weeks. Feasibility measures included recruitment rate, adherence, exercise induced pain, training acceptability, pain flares, and adverse events. Number of treatment responders, pain, grip strength, and hand function were also recorded.

RESULTS

In total, 191 participants were screened, 59 (31%) were included. Retention rate was 89% for BFRT and 79% for HIT. Exercise did not worsen pain following training sessions, and training acceptability was equal between groups. Pain flares occurred in 1.6% (BFRT) and 4% (HIT) out of all the training sessions. There was one adverse event in the HIT group, with the participants withdrawing from the study due to pain. The number of treatment responders, and improvements in pain, were greater with BFRT and HIT. Grip and function did not improve.

CONCLUSION

A clinical trial comparing resistance training to advice for people with symptomatic hand OA is feasible.

Partial warfarin reversal prior to hip fracture surgical intervention in geriatric trauma patients effects on blood loss and transfusions

BACKGROUND

Warfarin reversal is typically sought prior to surgery for geriatric hip fractures; however, patients often proceed to surgery with partial warfarin reversal. The effect of partial reversal (defined as having an international normalized ratio [INR] > 1.5) remains unclear.

METHODS

This was a retrospective cohort study. Geriatric patients (≥65 y/o) admitted to six level I trauma centers from 01/2014-01/2018 with isolated hip fractures requiring surgery who were taking warfarin pre-injury were included. Warfarin reversal methods included: vitamin K, factor VIIa, (a)PCC, fresh frozen plasma (FFP), and the "wait and watch" method. An INR of ≤ 1.5 defined complete reversal. The primary outcome was the volume of blood loss during surgery; other outcomes included packed red blood cell (pRBC) and FFP transfusions, and time to surgery.

RESULTS

There were 135 patients, 44% partially reversed and 56% completely reversed. The median volume of blood loss was 100 mL for both those completely and partially reversed, p = 0.72. There was no difference in the proportion of patients with blood loss by study arm, 95% vs. 95%, p > 0.99. Twenty-five percent of those completely reversed and 39% of those partially reversed had pRBCs transfused, p = 0.08. Of those completely reversed 5% received an FFP transfusion compared to 14% of those partially reversed, p = 0.09. There were no statistically significant differences observed for the volume of pRBC or FFP transfused, or for time to surgery.

CONCLUSIONS

Partial reversal may be safe for blood loss and blood product transfusions for geriatric patients with isolated hip fractures. Complete warfarin reversal may not be necessary prior to hip fracture surgery, especially for mildly elevated INRs.

Is anticoagulation reversal necessary prior to surgical treatment of geriatric hip fractures?

OBJECTIVE

Hip fracture surgery in geriatric patients on anticoagulants may increase the risk for blood loss. Anticoagulation reversal may lower these risks; however, data on blood loss and transfusions are limited. The study purpose was to compare outcomes between hip fracture patients 1) not on anticoagulants 2) whose anticoagulants were reversed, and 3) whose anticoagulants were not reversed.

METHODS

This four-year retrospective cohort study at six Level 1 Trauma Centers enrolled geriatric patients (≥65) with isolated hip fractures. The primary outcome was total hospital blood loss (ml). Secondary outcomes: hospital length of stay (HLOS) and volume of packed red blood cells (pRBC) transfusions (ml). Statistical analyses included: Fisher's, chi-squared, Kruskal-Wallis, linear mixed-effect and logistic regression. Bonferroni adjusted alpha = 0.025.

RESULTS

Of the 459 patients, 189 (41%) were not on anticoagulants, 186 (41%) were reversed, and 84 (18%) were not reversed. The LS mean (SE) blood loss was 134 ml (12) for not reversed patients and 159 (17) for reversed patients; no significant difference compared to those not on anticoagulants [138 (12)], p-diff = 0.14 and 0.83, respectively. The LS mean (SE) HLOS was significantly longer for the reversed patients, 7.7 (0.4) days, when compared to those not on anticoagulants, 6.8 (0.4), p = 0.02, and when compared to those not reversed, 6.3 (0.6), p = 0.01. There was no significant difference in pRBC transfusions.

CONCLUSION

Not reversing anticoagulants for geriatric hip fractures was not associated with increased volume of blood loss or transfusions when compared to those reversed. Delayed surgery for anticoagulant reversal may be unnecessary and contributing to an increased HLOS.

Clinically relevant redifferentiation of fibroblast-like chondrocytes into functional chondrocytes by the low molecular weight fraction of human serum albumin

OBJECTIVES

Traumatic joint injury induces chondrocyte dysfunction and progressive breakdown of articular cartilage, leading to post-traumatic osteoarthritis (PTOA). In this condition, dysfunctional fibroblast-like chondrocytes (FLCs) no longer express proteins required for cartilage maintenance, such as SOX9 and collagen-type II (COL2). Interleukin-6 (IL-6) has been demonstrated to downregulate expression of these two critical proteins in chondrocytes, and increased IL-6 levels have been measured in patients with PTOA. The <5kDa fraction of human serum albumin (LMWF5A) has been suggested to modulate this pathway, as decreased levels of IL-6 are secreted by immunostimulated LMWF5A-treated macrophages. Our objective was to determine whether LMWF5A induces an in vitro model of FLCs to redifferentiate into functional chondrocytes.

METHODS

SOX9 and COL2 were monitored via western blot, and COL2 was detected with immunofluorescence. Aggrecan and IL-6 were quantified by ELISA. Glycosaminoglycan (GAG) levels were quantified with alcian blue.

RESULTS

We found that LMWF5A significantly increases the principal cartilage transcription factor SOX9 and the SOX9 target protein COL2 in monolayer-cultured FLCs. Multiple LMWF5A treatments of 3-D pellet FLC cultures over 2wks resulted in a significant decrease in IL-6 and significant increases in the major players of articular cartilage mechanics, aggrecan and highly-sulfated GAGs.

CONCLUSIONS

These data support the hypothesis and clinical outcomes of two phase III clinical trials that LMWF5A-treatment induces chondrogenesis and supports functional cartilage. We propose that LMWF5A could maintain articular cartilage integrity in all joints following traumatic injury.

Mass Effect and Atrophy after Stroke

Cerebral edema, resolution of edema, and subsequent development of cerebral atrophy were studied prospectively in 83 patients with ischemic stroke with CT 3 days, 2 weeks, and 6 months post-stroke. Nineteen patients had large (diameter > 3 cm), 25 medium sized (diameter ≥ 1.5 ≤ 3 cm), and 15 lacunar infarcts (diameter < 1.5 cm). In 24 patients no infarcts were seen. Changes of Evans' ratio (ER), septum-caudate distance (S/C), and width of widest cortical sulci (SuW) were taken as markers of mass effect/atrophy. These parameters were within normal limits in most cases. However, when all CT scans performed in each patient were compared, changes of ER, S/C, and SuW became apparent as evidence of mass effect and subsequent atrophy development. Mass effect occurred in 81 percent and atrophy in 58 percent of patients with large infarcts. In patients with medium sized infarcts, mass effect occurred in 38 percent and atrophy in 45 percent.

From adverse drug event detection to prevention. A novel clinical decision support framework for medication safety

BACKGROUND

Errors related to medication seriously affect patient safety and the quality of healthcare. It has been widely argued that various types of such errors may be prevented by introducing Clinical Decision Support Systems (CDSSs) at the point of care.

OBJECTIVES

Although significant research has been conducted in the field, still medication safety is a crucial issue, while few research outcomes are mature enough to be considered for use in actual clinical settings. In this paper, we present a clinical decision support framework targeting medication safety with major focus on adverse drug event (ADE) prevention.

METHODS

The novelty of the framework lies in its design that approaches the problem holistically, i.e., starting from knowledge discovery to provide reliable numbers about ADEs per hospital or medical unit to describe their consequences and probable causes, and next employing the acquired knowledge for decision support services development and deployment. Major design features of the framework's services are: a) their adaptation to the context of care (i.e. patient characteristics, place of care, and significance of ADEs), and b) their straightforward integration in the healthcare information technologies (IT) infrastructure thanks to the adoption of a service-oriented architecture (SOA) and relevant standards.

RESULTS

Our results illustrate the successful interoperability of the framework with two commercially available IT products, i.e., a Computerized Physician Order Entry (CPOE) and an Electronic Health Record (EHR) system, respectively, along with a Web prototype that is independent of existing healthcare IT products. The conducted clinical validation with domain experts and test cases illustrates that the impact of the framework is expected to be major, with respect to patient safety, and towards introducing the CDSS functionality in practical use.

CONCLUSIONS

This study illustrates an important potential for the applicability of the presented framework in delivering contextualized decision support services at the point of care and for making a substantial contribution towards ADE prevention. Nonetheless, further research is required in order to quantitatively and thoroughly assess its impact in medication safety.

Practical clinical value of the C-peptide response to glucagon stimulation in the choice of treatment in diabetes mellitus

In order to discriminate between insulin-dependent and non-insulin-dependent patients, serum C-peptide concentration was determined using antiserum M1230 in the fasting state and 6 min after an i.v. injection of 1 mg glucagon in 215 patients treated with insulin and 53 treated with diet and oral antidiabetics. A patient was considered well controlled without insulin when fasting blood glucose was below 8 mmol/l and when glucosuria was absent. After re-evaluation of therapy in hospital it was found that the majority of patients with a post-stimulatory serum C-peptide concentration above 0.60 pmol/ml appeared to have non-insulin-dependent diabetes mellitus. When fasting C-peptide was used, a great overlap was found between the two treatment groups. During evaluation of therapy in hospital, 6 previously insulin-treated patients could be well treated with diet and tablets and 6 diet- and tablet-treated patients required insulin. The glucagon test seems to be of value in the outpatient clinic to discriminate non-insulin-dependent from insulin-dependent patients.

The role of stretching in tendon injuries

The function of tendons can be classified into two categories: tensile force transmission, and storage and release of elastic energy during locomotion. The action of tendons in storing and releasing energy is mainly seen in sports activities with stretch-shortening cycles (SSCs). The more intense the SSC movements are (jumping-like activities), the more frequently tendon problems are observed. High SSC movements impose high loads on tendons. Consequently, tendons that frequently deal with high SSC motion require a high energy-absorbing capacity to store and release this large amount of elastic energy. As the elasticity of tendon structures is a leading factor in the amount of stored energy, prevention and rehabilitation programmes for tendon injuries should focus on increasing this tendon elasticity in athletes performing high SSC movements. Recently, it has been shown that ballistic stretching can significantly increase tendon elasticity. These findings have important clinical implications for treatment and prevention of tendon injuries.

The value of the ankle-brachial index for diagnosing arterial injury after knee dislocation: a prospective study

BACKGROUND

The risk of arterial injury with knee dislocation is well known. The most effective method for rapidly and accurately diagnosing arterial injury in this setting remains a topic of debate. Both physical examination and arteriography have been advocated, although each of these methods has its critics. The authors propose that the ankle-brachial index (ABI) can accurately predict whether patients with knee dislocations have sustained vascular injury.

METHODS

A prospective study enrolled 38 patients with knee dislocation to evaluate for potential arterial injury using clinical pulse examination and ABI. Patients with an ABI lower than 0.90 underwent arteriography. Those with an ABI of 0.90 or higher were immobilized and admitted for serial examination and delayed arterial duplex evaluation.

RESULTS

Of the 38 patients, 11 (29%) had an ABI lower than 0.90. All 11 had arterial injury requiring surgical treatment. The remaining 27 patients had an ABI of 0.90 or higher. None had vascular injury detectable by serial clinical examination or duplex ultrasonography. The sensitivity, specificity, and positive predictive value of an ABI lower than 0.90 were 100%. The negative predictive value of an ABI that reached 0.90 or higher was 100%.

CONCLUSIONS

The ABI is a rapid, reliable, noninvasive tool for diagnosing vascular injury associated with knee dislocation. Routine arteriography for all patients with knee dislocation is not supported.

User requirements specifications: a hierarchical structure covering strategical, tactical and operational requirements

The present study is a long-term review and follow-up on conclusions and recommendations on the role and contents of a User Requirements Specification Document (URD) from a previous in-depth case study. The follow-up comprises a succession of investigations and two case studies to explore the role and contents of a URD within systems development and assessment, thereby gradually extending and refining the original recommendations. Finally, the recommended three-layered structure and approach for a URD were applied in full scale within a real-life project, in which the URD serves as the basis for a Call for Tender. The preparation was entirely user-driven with the aid of a consultant for four man months. The present paper outlines the essence of the approach and the outcome of applying the recommended structure, with numerous examples of the implications.

User requirements in a system development & evaluation context

The case study presented investigates how the interaction between users and developers changed when introducing a three level User Requirements Specification with a coarse granularity of the lowest (operational) requirements.

Cutaneous metal sensitivity in patients with orthopaedic injuries

BACKGROUND

Manufactures of orthopaedic fracture implants have turned to titanium in a pure form and an alloy during the past ten to fifteen years. Although primarily because of the biomechanical properties of this metal, concern for allergy to nickel and chromium ions in stainless steel was a factor in these decisions.

OBJECTIVES

To document the incidence of baseline sensitivity to metal ions and the incidence of conversion to sensitivity to one of three ions in stainless steel in a population of trauma patients at a Level I trauma center.

DESIGN

Prospective, consecutive patient series.

SETTING

Level I trauma center.

PATIENTS

Patients eighteen years of age and older with no history of metallic implants were recruited for this study between October 1995 and July 1997. Four hundred ninety-three patients had a Finn chamber device with chromium, nickel, and cobalt ions, which were read using a photographic scale on day three. Two hundred forty-two of these patients had placement of a second patch, at a mean interval of 187 days (range 45 to 589 days).

INTERVENTION

Internal fixation of fracture or osteotomy with metal implant. MAIN OUTCOME MANAGEMENT: Cutaneous reactivity to metal ions.

RESULTS

Prevalence of sensitivity to chromium was 0.2 percent, to nickel 1.3 percent, and to cobalt 1.8 percent. Rates for conversion from a negative to positive status were 2.7 percent for chromium, 3.8 percent for nickel, and 3.8 percent for cobalt. Rates for desensitization (i.e., converting from a positive to negative status) were 2.1 percent for nickel and 3.8 percent for cobalt.

CONCLUSION

The prevalence of sensitivity to nickel, cobalt, and chromium is apparently low. Similarly, internal fixation devices composed of stainless steel appear to result in an equal incidence of conversion to metal ionic sensitivity and desensitization to metal ions. It is conceivable that cutaneous sensitivity is not representative of deep immune response.

Screening for preclinical type 1 diabetes in a discrete population with an apparent increased disease incidence

Environmental agents are proposed to play a role in triggering or exacerbating pancreatic islet autoimmunity in people genetically predisposed to type 1 diabetes. However, with few exceptions, these agents remain enigmatic. Clues to environmental agents may be found by investigating population/geographic clusters or 'hotspots' of high disease incidence. We were alerted to a small community where the incidence of type 1 diabetes appeared to be five-fold higher than expected. Because type 1 diabetes is now recognized to have a subclinical phase during which anti-islet antibodies can be detected, we aimed to identify and characterize a reservoir of children with subclinical disease in this community. Venous blood samples were collected from 1906/2347 (81%) local school children during one week. Islet cell antibodies (ICAs) were detected in 122 (6.4%) children, 18 (0.9%) being high titer (> or = 20 Juvenile Diabetes Foundation units (JDFu)). On retest, 15 months later, the majority of low titer ICAs were undetectable, whereas high-titer ICAs persisted. The latter were found in two distinct age-related, ethnically similar groups. The younger group, aged 6-9 yr, had antibodies to insulin (IAAs), glutamic acid decarboxylase (GAD) and tyrosine phosphatase IA2 in addition to ICA, human leukocyte antigen (HLA) genes associated with susceptibility to type 1 diabetes, and lower first-phase insulin responses (FPIRs) to intravenous glucose. The older group, aged 13-16 yr, the age cohort of the index clinical cases, had few antibodies other than ICA, non-susceptibility HLA genes and normal FPIRs. During follow-up, three children, all from the younger group with multiple antibodies and FPIRs less than the first percentile, developed diabetes 4, 6 and 7 yr after screening. The finding of two age groups of subclinical disease suggests that if environmental agents triggered islet autoimmunity they did not act constantly on the community. Furthermore, the absence of multiple autoantibodies and/or HLA susceptibility genes in the older group, the source of index clinical cases, implies they are a residual subgroup with slow or absent progressive beta-cell destruction. This study illustrates that the natural history of type 1 diabetes may be elucidated by analyzing age-related subclinical disease in the general population.

Research needs and priorities in health informatics

A Delphi study was accomplished on the topic "what is needed to implement the information society within healthcare? and which research topics should be given higher priority than other topics to achieve the desired evolution?", involving 29 international experts. The study comprised of four phases, (I) a brainstorming phase based on a open question; (II) an evaluation phase for mutual commenting; (III) a feedback phase allowing corrections/extensions; and (IV) a phase collecting the ratings of individual issues within a questionnaire synthesised from the previous phases. A total of 110 research items and 58 supplementary barriers were raised, divided into 14 topics grouped according to homogeneity. The emphasised research topics are business process re-engineering, the electronic patient record and connected inter-operating systems, (support for) evidence-based medicine and clinical guidelines, and education. Issues inherent to the healthcare domain often are the kernel of the research recommended. Similarly, methods and 'people'-issues are strongly emphasised among the research issues in general and among those for which the experts' joint opinion was rated as statistically significant. In contrast, only a minority of the research issues emphasised was related to technical issues.

Research needs and priorities in health informatics--early results of a Delphi study

A four-phased Delphi study has been performed on the topic of "research needs and priorities to implement the Information Society within Healthcare". This contribution presents the outcome of the first three phases. The biggest surprises are that 'Telemedicine' is relatively lower ranked than expected, and that 'Business Process Re-engineering' is the highest ranking topic, as judged from the number of issues and barriers raised by the expert panel.

Landing in netball: effects of taping and bracing the ankle

OBJECTIVES

To investigate the effect of bracing and taping on selected electromyographic, kinematic, and kinetic variables when landing from a jump.

METHODS

Fifteen netball players performed a jump, so as to land on their dominant limb on a force plate. Electromyographic activity was recorded from the gastrocnemius, tibialis anterior, and peroneus longus muscles. Subjects were also filmed and measures of rearfoot motion were derived.

RESULTS

Significantly less electromyographic activity (p<0.007) was observed from the gastrocnemius and peroneus longus muscle groups when subjects were braced. No other significant electromyographical findings were observed. Peak vertical ground reaction force and time to peak for vertical ground reaction force were not affected by bracing and taping, nor were the rearfoot and Achilles tendon angles at foot strike.

CONCLUSIONS

The effect of bracing and taping on the selected biomechanics variables associated with landing was specifically limited to a reduction in muscle action, particularly for the braced condition. Netball players can be confident that the biomechanics of their landing patterns will not be altered whether they choose to wear a brace or tape their ankle joints.

Computer-aided test selection and result validation-opportunities and pitfalls

Dynamic test scheduling is concerned with pre-analytical preprocessing of the individual samples within a clinical laboratory production by means of decision algorithms. The purpose of such scheduling is to provide maximal information with minimal data production (to avoid data pollution and/or to increase cost-efficiency). Our experience shows that there is a practical limit to the extent of exploitation of the principle of dynamic test scheduling, unless it is automated in one way or the other. This paper analyses some issues of concern related to the profession of clinical biochemistry, when implementing such dynamic test scheduling within a Laboratory Information System (and/or an advanced analytical workstation). The challenge is related to 1) generation of appropriately validated decision models, and 2) mastering consequences of analytical imprecision and bias.

The Melbourne Pre-Diabetes Study: prediction of type 1 diabetes mellitus using antibody and metabolic testing

OBJECTIVES

To determine the utility of various autoantibodies in predicting progression to clinical diabetes in first-degree relatives of patients with type 1 diabetes mellitus.

PARTICIPANTS

3315 first-degree relatives of patients with type 1 diabetes (1161 parents, 1206 siblings and 948 offspring) recruited through diabetes clinics, private endocrinologists, Diabetes Australia and the Juvenile Diabetes Foundation.

MAIN OUTCOME MEASURES

Prevalence of islet cell antibodies (ICA) levels > or = 20 JDFu, insulin autoantibodies (IAA) levels > 100 nU/mL, and antibodies to glutamic acid decarboxylase (GADAb) and tyrosine phosphatase IA2 (IA2Ab); change in beta cell function over time; and development of clinical diabetes.

RESULTS

2.6% of relatives had elevated ICA levels, 1.3% had elevated IAA levels and 0.3% had both. High ICA levels were significantly more frequent in siblings than in offspring or parents, and were more frequent in relatives younger than 20 years. GADAb were detected in 68% and IA2Ab in 57% of relatives with elevated ICA and/or IAA levels. Diabetes developed in 33 relatives (25 siblings, 2 offspring and 6 parents). Before diagnosis of clinical diabetes, high ICA levels were detected in 18 (58%), high IAA levels in 7 (23%), both in 5 (15%), and either in 19 (61%); GADAb were detected in 26 (84%), IA2Ab in 13 (42%), both in 11 (35%), and either in 28 (90%). First phase insulin release (FPIR) less than 50 mU/L was very strongly associated with progression to diabetes. In relatives with FPIR initially greater than 50 mU/L who eventually developed diabetes, there was a gradual and continuous reduction in FPIR over time before diagnosis.

CONCLUSIONS

Type 1 diabetes can be diagnosed in the preclinical stage. The recently described antibodies to glutamic acid decarboxylase and tyrosine phosphatase IA2 appear superior to ICA as screening tools for the preclinical diagnosis of type 1 diabetes.

Diurnal rhythms of pro-inflammatory cytokines: regulation by plasma cortisol and therapeutic implications

Clinical features of certain immuno-inflammatory disorders such as rheumatoid arthritis and asthma exhibit diurnal fluctuation, which could be related to diurnal rhythmicity of pro-inflammatory cytokine production. To investigate the latter, the authors performed measurements of lipopolysaccharide (LPS)-stimulated whole blood, interferon gamma (IFN-gamma), tumour necrosis factor alpha (TNF-alpha), interleukin 1 (IL-1) and IL-12 production in 13 healthy volunteers over 24 h. These cytokines exhibited distinct diurnal rhythms that peaked in the early morning and were inversely related to the rhythm of plasma cortisol. Elevation of plasma cortisol within the physiological range by administration of cortisone acetate, 25 mg at 21.00, markedly suppressed IFN-gamma, TNF-alpha, IL-1 and IL-12 production, but not the later early morning rise of endogenous plasma cortisol. Suppression of cytokine production was temporally dissociated from changes in numbers of circulating mononuclear cells. Regulation of pro-inflammatory cytokine production by plasma cortisol has potential therapeutic implications. In contrast to standard schedules, a small, late evening, dose of glucocorticoid to suppress the diurnal increase in pro-inflammatory cytokine production could alleviate early morning inflammatory symptoms and minimize side-effects.

Incidence of sporting injury in New Zealand youths aged 6-15 years

OBJECTIVE

To document the incidence of injury in 6-15 year olds playing rugby union, rugby league, and netball, and to identify the common mechanisms, sites, severity, and time of injury.

METHODS

Cross sectional data were collected by trained observers who watched 258 games of rugby union, netball, and rugby league over a four week period. The condition of the injured participants was monitored until recovery.

RESULTS

In total, 5174 players were observed and an injury rate of 18 per 1000 player hours was calculated. Of all observed injuries, 29% required some form of medical treatment. A significant difference (p<0.05) in the distribution of injury over the four quarters of the games was recorded, most occurring in the first three quarters. In total, 81% of the injuries were classified as contact injuries, and these mainly occurred through direct contact with the opposition. Of all observed injuries, 27% were recurrent.

CONCLUSIONS

The incidence of injury in rugby union, netball, and rugby league is low for children aged between 6 and 15 years relative to adult rates.

Lymphocytopenia in a hospital population--what does it signify?

BACKGROUND

Lymphocytopenia is a common finding in hospital patients especially since the advent of automated differential leukocyte counters. The causes and significance of lymphocytopenia are generally poorly understood. There has been no large-scale study of its significance for 25 years. The HIV epidemic, and the recently described idiopathic CD4+ T-lymphocytopenia have raised interest in this finding.

AIMS

To describe the spectrum of lymphocytopenia in an adult teaching hospital and investigate its clinical significance.

METHODS

Using the available computer facilities, patients with significant lymphocytopenia (< 0.6 x 10(9)/L) were identified over a 102 day period and diagnoses, operations and medication lists obtained. Where necessary, patient histories were examined to supplement the above information. If feasible, previous and subsequent lymphocyte counts were checked to establish if the lymphocytopenia were temporary or longstanding.

RESULTS

One thousand and forty-two patients were identified, with a mean age of 59.6 years, of whom 563 were male, and 757 were inpatients. Thirty-six patients were pancytopenic. We checked previous and subsequent counts for 698 patients and found 45 patients who were consistently lymphocytopenic, some for more than ten years. Thirty-four patients with previously normal counts remained lymphocytopenic throughout follow up, while 457 had at least one subsequent lymphocyte count > 1 x 10(9)/L. We found only one patient who was suspected of having idiopathic CD4+ T-lymphocytopenia. Patients fell into several categories (with some overlap): bacterial/fungal sepsis (250), post-operative (228), corticosteroid therapy (definite 159, suspected 53, inhaled steroids alone 14), malignancy (174 definite, six probable), cytotoxic therapy and/or radiotherapy (90), trauma or haemorrhage (86), transplants (73-38 renal and 35 bone marrow), 'viral infections' (26) and HIV infection (13). Thirty-four patients died within the study period.

CONCLUSIONS

Lymphocytopenia in hospital patients is most frequently reversible, and due to acute illness, notably sepsis and trauma (including surgery). Malignancy, with or without chemotherapy, and steroid use are also common causes, but HIV infection is a relatively uncommon cause in our hospital.

User requirements on the future laboratory information systems

Today numerous information technology solutions exist for the clinical laboratory which operate either as stand-alone functionalities or with ad hoc integration solutions. The OpenLabs (A2028) AIM Project puts emphasis on the design and specification of a framework for the interoperability of existing systems and new advanced services, and consequently concentrates on the issue of integration. The purpose of the OpenLabs open architecture is to serve as a functional solution to this integration. A basic principle for this open architecture is that each of the advanced services shall be able to function individually or in any combination with an existing Laboratory Information System (LIS), and that it shall enable new modular functionalities to be incorporated in a 'plug-and-play' fashion. The synthesis of the main user needs and requirements implies that the future IT solutions: (a) must be highly flexible and maximally customizable--by the users themselves; (b) are based on the concept of open systems, both technically and functionally, which enables modular functionalities from different vendors to co-operate forming a global LIS functionality; (c) are future viable and able to incorporate already installed IT functionalities; (d) support management of failure prevention, of repair, of success, and of change. The establishment of an open architecture implies that a market will develop for modular, scaleable, and cost-effective LIS features without today's dependence on individual manufacturers and hardware/software platforms.

Time course of platelet alpha granule release in acute myocardial infarction treated with streptokinase

OBJECTIVE

To determine the time course of platelet alpha granule release in patients with acute myocardial infarction treated with streptokinase.

DESIGN

A prospective study.

SETTING

Coronary care unit.

PATIENTS

Nine with myocardial infarction treated with both streptokinase and aspirin, and nine with acute chest pain but without myocardial infarction, who were treated with aspirin only.

METHODS

All patients received 250 mg aspirin on admission and 150 mg once daily thereafter. All patients who fulfilled the indications for streptokinase received 1.5 megaunits, in a single infusion. After the initial medication, serial measurements of plasma beta thromboglobulin and plasma platelet factor 4 were performed at fixed intervals after the onset of chest pain. The primary endpoint sought was the peak value of beta thromboglobulin and platelet factor 4 in each individual.

RESULTS

The median peak plasma beta thromboglobulin in the infarction group was substantially higher than in those without infarction, at 37 (range 12 to 210) v 15 (9 to 36) mg/litre, P < 0.01. The corresponding values for plasma platelet factor 4 were 4.6 (2.4 to 60.0) v 2.2 (< 2 to 8.5) mg/litre, P < 0.01. Increased values were seen only within the first 12 h after onset of chest pain, and after 12 h there was no difference between the patients with myocardial infarction and those without. Aspirin treatment did not abolish alpha granule release.

CONCLUSIONS

In patients with acute myocardial infarction treated with streptokinase the content of the alpha granules is released within the first 12 h after the onset of chest pain. Aspirin apparently does not abolish this release.

Within-centre evaluation of hypercalcaemia discriminant functions 5 years after their development

Diagnostic hypercalcaemia discriminant functions, discriminating between clinically significant and non-significant hypercalcaemia, were tested 5 years after their development in order to evaluate the impact of time on their diagnostic capacity. Two populations, consisting of 257 and 129 patients with hypercalcaemia, were consecutively recorded, during six and three months respectively, 5 years apart under similar circumstances. The prevalence of hypercalcaemia was comparable in both populations, being 2.57 and 2.38% respectively (non-significant) (NS). The female/male ratio was 1.9 and 1.7 (NS). The discriminant functions correctly classified 81 and 80% of the women, respectively (NS) and respectively 75% and 64% of the men (NS) in the first and second recorded populations.

User-requirements driven learning

This paper describes an approach for deriving classification knowledge from databases, taking into account user preferences. These preferences especially concern the trade-off between different kinds of costs and performance indicators of the classification scheme to be developed. We analyze what knowledge, provided by the user, can be used at various stages of the machine learning process to influences the development of the classifier. We restrict ourselves in this paper mainly to the generation of classification trees.

Similar peptides from two beta cell autoantigens, proinsulin and glutamic acid decarboxylase, stimulate T cells of individuals at risk for insulin-dependent diabetes

BACKGROUND

Insulin (1) and glutamic acid decarboxylase (GAD) (2) are both autoantigens in insulin-dependent diabetes mellitus (IDDM), but no molecular mechanism has been proposed for their association. We have identified a 13 amino acid peptide of proinsulin (amino acids 24-36) that bears marked similarity to a peptide of GAD65 (amino acids 506-518) (G. Rudy, unpublished). In order to test the hypothesis that this region of similarity is implicated in the pathogenesis of IDDM, we assayed T cell reactivity to these two peptides in subjects at risk for IDDM.

MATERIALS AND METHODS

Subjects at risk for IDDM were islet cell antibody (ICA)-positive, first degree relatives of people with insulin-dependent diabetes. Peripheral blood mononuclear cells from 10 pairs of at-risk and HLA-DR matched control subjects were tested in an in vitro proliferation assay.

RESULTS

Reactivity to both proinsulin and GAD peptides was significantly greater among at-risk subjects than controls (proinsulin; p < 0.008; GAD; p < 0.018). In contrast to reactivity to the GAD peptide, reactivity to the proinsulin peptide was almost entirely confined to the at-risk subjects.

CONCLUSIONS

This is the first demonstration of T cell reactivity to a proinsulin-specific peptide. In addition, it is the first example of reactivity to a minimal peptide region shared between two human autoimmune disease-associated self antigens. Mimicry between these similar peptides may provide a molecular basis for the conjoint autoantigenicity of proinsulin and GAD in IDDM.