An overview of reviews and synthesis across 440 studies examines the importance of hospital readmission predictors across various patient populations

OBJECTIVES

The scientific literature contains an abundance of prediction models for hospital readmissions. However, no review has yet synthesized their predictors across various patient populations. Therefore, our aim was to examine predictors of hospital readmissions across 13 patient populations.

STUDY DESIGN AND SETTING

An overview of systematic reviews was combined with a meta-analytical approach. Two thousand five hundred four different predictors were categorized using common ontologies to pool and examine their odds ratios and frequencies of use in prediction models across and within different patient populations.

RESULTS

Twenty-eight systematic reviews with 440 primary studies were included. Numerous predictors related to prior use of healthcare services (odds ratio; 95% confidence interval: 1.64; 1.42-1.89), diagnoses (1.41; 1.31-1.51), health status (1.35; 1.20-1.52), medications (1.28; 1.13-1.44), administrative information about the index hospitalization (1.23; 1.14-1.33), clinical procedures (1.20; 1.07-1.35), laboratory results (1.18; 1.11-1.25), demographic information (1.10; 1.06-1.14), and socioeconomic status (1.07; 1.02-1.11) were analyzed. Diagnoses were frequently used (in 37.38%) and displayed large effect sizes across all populations. Prior use of healthcare services showed the largest effect sizes but were seldomly used (in 2.57%), whereas demographic information (in 13.18%) was frequently used but displayed small effect sizes.

CONCLUSION

Diagnoses and patients' prior use of healthcare services showed large effects both across and within different populations. These results can serve as a foundation for future prediction modeling.

Essential steps in the development, implementation, evaluation and quality assurance of the written part of the Swiss federal licensing examination for human medicine

PURPOSE

This report describes the essential steps in the development, implementation, evaluation and quality assurance of the written part of the Swiss Federal Licensing Examination for Human Medicine (FLE) and the insights gained since its introduction in 2011.

METHODS

Based on existing scientific evidence, international expertise, and experience gained from previous examinations, the FLE is developed by experts from all five medical faculties in Switzerland with the support of the Institute for Medical Education and is held simultaneously at five locations. The exam organisers document and review every examination held and continuously optimise the processes; they have summarised the results in this report.

RESULTS

The essential steps comprise the development, revision and translation of questions; construction of the exam and production of materials; candidate preparation; implementation and analysis. The quality assurance measures consist of guideline coherence in the development of the questions and implementation of the exam, revision processes, construction of the exam based on the national blueprint, multiphase review of the translations and exam material, and statistical analysis of the exam and the comments from candidates. The intensive collaboration, especially on the part of representatives from all the participating faculties and a central coordination unit, which provides methodological support throughout and oversees the analysis of the exam, has proven successful. Successfully completed examinations and reliable results in the eleven examinations so far implemented represent the outcomes of the quality assurance measures. Significant insights in recent years are the importance of appreciating the work of those involved and the central organisation of exam development, thus ensuring the long-term success of the process.

CONCLUSION

Common guidelines and workshops, quality assurance measures accompanied by the continuous improvement of all processes, and appreciation of everyone involved, are essential to carrying out such an examination at a high-quality level in the long term.

Iron supplementation in Switzerland - A bi-national, descriptive and observational study

BACKGROUND

Iron deficiency is the most common nutritional disorder in the world, and it is the only common nutrient deficiency in industrialised nations. It is thought to be the most common cause of anaemia. Use of iron supplementation in Switzerland has not been previously quantified in detail.

OBJECTIVES

We quantified use of iron supplementation from Swiss data and compared it with data from the UK. We assessed the frequency of serum ferritin and haemoglobin tests prior to newly started iron therapy to see whether use was based on documented low iron levels or blood parameters, especially in the case of parenteral iron supplementation.

METHODS

We conducted a retrospective descriptive study of prescription iron supplementation use, and compared use of oral or parenteral iron drugs between Switzerland (CH) and the UK. We retrieved Swiss data from the Swiss Health Insurance Helsana Group, and UK data were from the Clinical Practice Research Datalink (CPRD). The study period was 2012 to 2014.

RESULTS

The 3-year prevalence of iron supplementation was 9.4% in Switzerland and 4.4% in the UK. Iron use increased slightly between 2012 and 2014 in both countries (CH +0.3%, UK +0.2%). Recorded parenteral iron administration was roughly a thousand times higher in Switzerland (1.9%) than in the UK in 2014. In Switzerland, iron supplements were mostly given to patients aged 20 to 49 years or older than of 80 years. In the UK, iron supplementation was less frequent in younger people, but more prevalent in the elderly. Prior to a first iron prescription, ferritin tests were done more frequently in Switzerland (oral 67.2%, parenteral 86.6%) than in the UK (oral 43.3%, parenteral 65.5%). Haemoglobin was measured before a new parenteral iron therapy rarely in Switzerland (oral 14.9%, parenteral 11.7%), but frequently in the UK (oral 77.4%, parenteral 85.6%).

CONCLUSIONS

Iron supplementation is more common in Switzerland than in the UK, particularly parenteral iron supplementation. Haemoglobin measurements prior to a new parenteral iron therapy are relatively infrequent in Switzerland despite the required documentation of haemoglobin prior to therapy.

Tapering for marathon and cardiac autonomic function

The purpose of this study was to investigate changes in post-exercise heart rate recovery (HRR) and heart rate variability (HRV) during an overload-tapering paradigm in marathon runners and examine their relationship with running performance. 9 male runners followed a training program composed of 3 weeks of overload followed by 3 weeks of tapering (-33 ± 7%). Before and after overload and during tapering they performed an exhaustive running test (T(lim)). At the end of this test, HRR variables (e.g. HRR during the first 60 s; HRR(60 s)) and vagal-related HRV indices (e.g. RMSSD(5-10 min)) were examined. T(lim) did not change during the overload training phase (603 ± 105 vs. 614 ± 132 s; P = 0.992), but increased (727 ± 185 s; P = 0.035) during the second week of tapering. Compared with overload, RMSSD(5-10 min) (7.6 ± 3.3 vs. 8.6 ± 2.9 ms; P = 0.045) was reduced after the 2(nd) week of tapering. During tapering, the improvements in T(lim) were negatively correlated with the change in HRR(60 s) (r = -0.84; P = 0.005) but not RMSSD(5-10 min) (r = -0.21; P = 0.59). A slower HRR during marathon tapering may be indicative of improved performance. In contrast, the monitoring of changes in HRV as measured in the present study (i.e. after exercise on a single day), may have little or no additive value.

[Practical aspects of medication safety]

The incidence of adverse drug events (ADE) in hospitalized patients and ambulatory care is high. Next to human suffering they cause considerable additional cost and a prolonged length of stay. The reduction of ADE incidence is badly needed. Measures to reach this goal next to teaching are electronic prescribing tools with decision support, clinical pharmacists on ward rounds, therapeutic drug monitoring, smart infusion pumps and identification tools such as bar-coding and radio-frequency identification for patients, drugs and health professionals. Importantly, while integrating these technical tools, workflows of health professionals have to be considered and should be combined with a scientific analysis to uphold and ameliorate patient safety.

Risk of falls and major bleeds in patients on oral anticoagulation therapy

BACKGROUND

The risk of falls is the most commonly cited reason for not providing oral anticoagulation, although the risk of bleeding associated with falls on oral anticoagulants is still debated. We aimed to evaluate whether patients on oral anticoagulation with high falls risk have an increased risk of major bleeding.

METHODS

We prospectively studied consecutive adult medical patients who were discharged on oral anticoagulants. The outcome was the time to a first major bleed within a 12-month follow-up period adjusted for age, sex, alcohol abuse, number of drugs, concomitant treatment with antiplatelet agents, and history of stroke or transient ischemic attack.

RESULTS

Among the 515 enrolled patients, 35 patients had a first major bleed during follow-up (incidence rate: 7.5 per 100 patient-years). Overall, 308 patients (59.8%) were at high risk of falls, and these patients had a nonsignificantly higher crude incidence rate of major bleeding than patients at low risk of falls (8.0 vs 6.8 per 100 patient-years, P=.64). In multivariate analysis, a high falls risk was not statistically significantly associated with the risk of a major bleed (hazard ratio 1.09; 95% confidence interval, 0.54-2.21). Overall, only 3 major bleeds occurred directly after a fall (incidence rate: 0.6 per 100 patient-years).

CONCLUSIONS

In this prospective cohort, patients on oral anticoagulants at high risk of falls did not have a significantly increased risk of major bleeds. These findings suggest that being at risk of falls is not a valid reason to avoid oral anticoagulants in medical patients.

A single-dose, placebo- and moxifloxacin-controlled 3-period study of the effects of temsirolimus on cardiac repolarization in healthy subjects

2551

Background: Temsirolimus (CCI-779) is a novel selective inhibitor of the mammalian target of rapamycin (mTOR) approved by the US FDA for the treatment of patients with advanced renal cell carcinoma. This study was designed to assess the effect of a single dose of 25 mg IV temsirolimus on the corrected QT interval (QTc) in healthy subjects. Methods: Fifty-eight (58) healthy subjects were enrolled in this 3-period crossover study. In periods 1 and 2, subjects were administered IV placebo either alone or with open-label oral moxifloxacin. In period 3, subjects were administered 25 mg IV temsirolimus. Serial ECGs were digitally captured in triplicate and manually over read by a central vendor. The primary statistical objective was to estimate the effect of temsirolimus compared with placebo on change from time-matched baseline QTc at the end of infusion (0.5 hour time point). Secondary endpoints and objectives included estimates of effect at 12 additional time points, population PKPD analyses, and categorical summaries of interval data. Assay sensitivity was evaluated by the effect of moxifloxacin on change from time-matched baseline QTc as compared with placebo. Results: Temsirolimus had no effect on the QTc interval in the primary analysis. At 11 of 12 secondary time points, the upper bound for the temsirolimus QTc 90% CIs for the time-matched change from baseline difference from placebo was less than 10 msec without evidence of QTc trends or relationship to temsirolimus or sirolimus whole blood concentrations. Mean concentrations were comparable to those observed in patients with renal cell carcinoma following administration of 25 mg IV temsirolimus. Moxifloxacin produced a statistically significant increase in the QTc interval as compared with placebo. No relevant PKPD relationship was seen using linear or Emax models. No subject in this study had a QTc interval exceeding 450 msec and no subjects had a change from baseline >30 msec. Conclusions: We conclude that therapeutic exposures of temsirolimus are not associated with changes in QTc interval that reach the level of regulatory significance, according to ICH E14 guidance. The findings are consistent with the lack of QTc interval prolongation observed in studies of cancer patients.

[Table: see text]

Outcomes of early switching from intravenous to oral antibiotics on medical wards

Objectives

To evaluate outcomes following implementation of a checklist with criteria for switching from intravenous (iv) to oral antibiotics on unselected patients on two general medical wards.

Methods

During a 12 month intervention study, a printed checklist of criteria for switching on the third day of iv treatment was placed in the medical charts. The decision to switch was left to the discretion of the attending physician. Outcome parameters of a 4 month control phase before intervention were compared with the equivalent 4 month period during the intervention phase to control for seasonal confounding (before–after study; April to July of 2006 and 2007, respectively): 250 episodes (215 patients) during the intervention period were compared with the control group of 176 episodes (162 patients). The main outcome measure was the duration of iv therapy. Additionally, safety, adherence to the checklist, reasons against switching patients and antibiotic cost were analysed during the whole year of the intervention (n = 698 episodes).

Results

In 38% (246/646) of episodes of continued iv antibiotic therapy, patients met all criteria for switching to oral antibiotics on the third day, and 151/246 (61.4%) were switched. The number of days of iv antibiotic treatment were reduced by 19% (95% confidence interval 9%–29%, P = 0.001; 6.0–5.0 days in median) with no increase in complications. The main reasons against switching were persisting fever (41%, n = 187) and absence of clinical improvement (41%, n = 185).

Conclusions

On general medical wards, a checklist with bedside criteria for switching to oral antibiotics can shorten the duration of iv therapy without any negative effect on treatment outcome. The criteria were successfully applied to all patients on the wards, independently of the indication (empirical or directed treatment), the type of (presumed) infection, the underlying disease or the group of antibiotics being used.

Differential effects of ketoconazole on exposure to temsirolimus following intravenous infusion of temsirolimus

Intravenous (i.v.) temsirolimus, a novel inhibitor of mammalian target of rapamycin, is approved for the treatment of advanced renal cell carcinoma and is being studied in patients with mantle cell lymphoma. Because temsirolimus and its primary metabolite, sirolimus, are metabolised by the cytochrome P450 3A4 pathway (CYP3A4), the potential exists for pharmacokinetic (PK) drug interactions with the numerous agents that modulate CYP3A4 isozyme activity. We investigated the effects of ketoconazole, a potent CYP3A4 inhibitor, on the PK profile of i.v. temsirolimus in healthy adults. Coadministration of 400 mg oral ketoconazole with 5 mg i.v. temsirolimus had no significant effect on temsirolimus maximum concentration (C_max) or area under the concentration curve (AUC). However, mean AUC increased 3.1-fold and AUC_sum (sum of temsirolimus plus sirolimus AUCs) increased 2.3-fold compared with temsirolimus alone. A single 5-mg dose of temsirolimus with ketoconazole was well tolerated, and there were no unexpected safety results. Therefore, in cancer patients receiving 25 mg i.v. temsirolimus, concomitant treatment with agents that have strong CYP3A4 inhibition potential should be avoided. If a concomitant strong CYP3A4 inhibitor is necessary, a temsirolimus dose reduction to 12.5 mg weekly should be considered.

Atypisches Erythema induratum Bazin bei tuberkulöser Osteomyelitis

Diagnosis of all types of cutaneous tuberculosis is challenging because the clinical picture of these diseases is highly variable. We describe the case of a 79-year old woman with an atypical presentation of Erythema induratum Bazin (EIB) on the chest and left arm in association with a tuberculous osteomyelitis of the left olecranon. Surprisingly, M. tuberculosis grew also from biopsies of the EIB-lesions. This contradicts the conventional view that considers EIB (a tuberculid) to be caused by a hypersensitivity reaction to mycobacteria. The presented case supports the hypothesis that EIB may also be caused by hematogenous or lymphatic spread of viable M. tuberculosis.

Echocardiographic quantification of atherosclerosis leads to cost-effective treatment with statins

OBJECTIVE

Use of statins in prevention of atherosclerosis is effective but expensive. Patient selection gains wider public attention as medication costs in the US and Europe augment by 8% to 10% per year. We examined different clinical risk stratification strategies, particularly focusing on echocardiographic atherosclerosis quantification, for their impact on event reduction and cost-effectiveness in statin treatment.

METHODS AND RESULTS

In a prospective, consecutive cohort of 336 patients referred to non-invasive cardiac examination, risk stratification was done by various combinations of risk factors and noninvasive atherosclerosis quantification. Atherosclerotic burden was determined through measuring "aortic elastance" by transthoracic echocardiogram, a validated non-invasive method. Cardiovascular events were recorded at a mean follow-up of one year. Echocardiographically determined atherosclerosis severity and event history, especially in combination, yielded the best selection strategies for statin treatment over a broad range of predetermined funding or required event reductions, surpassing conventional cardiovascular risk factors. From 26.8 statin-preventable events/1000 patients/year (assuming all patients treated), the best selection strategies could avoid: 24 with 66% of the cost for statin treatment (atherosclerosis and age criteria), 20.1 with <50% of the budget, 12.2 with <30% of the budget or 9.6 with <15% of the budget (using combinations of atherosclerosis and prior events), while conventional strategies without echo quantification of atherosclerosis were inferior.

CONCLUSION

Non-invasive echocardiographic quantification of atherosclerosis improves efficiency and cost-effectiveness in statin treatment.

Echocardiographic quantification of atherosclerosis leads to cost-effective treatment with statins

OBJECTIVE

Use of statins in prevention of atherosclerosis is effective but expensive. Patient selection gains wider public attention as medication costs in the US and Europe augment by 8% to 10% per year. We examined different clinical risk stratification strategies, particularly focusing on echocardiographic atherosclerosis quantification, for their impact on event reduction and cost-effectiveness in statin treatment.

METHODS AND RESULTS

In a prospective, consecutive cohort of 336 patients referred to non-invasive cardiac examination, risk stratification was done by various combinations of risk factors and noninvasive atherosclerosis quantification. Atherosclerotic burden was determined through measuring "aortic elastance" by transthoracic echocardiogram, a validated non-invasive method. Cardiovascular events were recorded at a mean follow-up of one year. Echocardiographically determined atherosclerosis severity and event history, especially in combination, yielded the best selection strategies for statin treatment over a broad range of predetermined funding or required event reductions, surpassing conventional cardiovascular risk factors. From 26.8 statin-preventable events/1000 patients/year (assuming all patients treated), the best selection strategies could avoid: 24 with 66% of the cost for statin treatment (atherosclerosis and age criteria), 20.1 with <50% of the budget, 12.2 with <30% of the budget or 9.6 with <15% of the budget (using combinations of atherosclerosis and prior events), while conventional strategies without echo quantification of atherosclerosis were inferior.

CONCLUSION

Non-invasive echocardiographic quantification of atherosclerosis improves efficiency and cost-effectiveness in statin treatment.

[Wound botulism after drug injection]

CLINICAL PRESENTATION

A 32-year old male drug user presented with diplopia, ataxia and general weakness. The patient had abscesses on arms and legs at injection sites, bilateral ptosis, a bifacial weakness, nasal speech, severely reduced ability to raise his arms and a positive Trendelelenburg sign with normal motor neuron reflexes and normal sensation.

CLINICAL AND LABORATORY TESTS

The haematological values indicated a hypochromic, microcytic anaemia (12,1 mg/dl), a slight leuko (10,8 G/L) - and thrombocytosis (582G/l) with elevated erythrocyte sedimentation rate (74 mm/h), and a reduced prothrombin time (67%). The HIV test was negative. The MRI scan of the brain and the bacterial, serological and cytological results of a lumbar puncture were normal. In the bloodculture no bacterial growth and no botulinum toxin was found. In a culture of the wound material grew coagulase-negative staphylococcus and Clostridium perfringens, diagnosed with PCR. The serum anti-acethylcholine antibodies were negative. The motor-nerve conduction test with repetitive stimulation of the ulnari nerve with a 3 Hz trigger showed no change in the amplitude, while a 20 Hz trigger showed an increment up to 160 %.

DIAGNOSIS, TREATMENT AND RESPONSE TO THERAPY

Another possible diagnosis was excluded through MRI, CSF and serum examination. The typical presentation of a rapidly progressive descending paralysis without loss of sensation and the typical motor-nerve conduction disorder of a presynaptic block established the diagnosis of wound botulism. This was treated immediately by surgical removal of wound debris, antitoxin- and penicillin therapy. After 28 days the patient left the hospital with slight residual problems. He had been admitted to the intensive care unit for a short period only and intubation was not necessary at any time.

CONCLUSION

After exclusion of any other possible diagnosis, it is possible to establish an early diagnosis of injection related wound botulism by its typical symptoms and signs. These are presented as wound abcesses at intramuscular drug injection sites together with rapidly progressive descending paralysis with preserved sensation. Treatment consists of surgical excision of wound debris combined with antitoxin and penicillin administration in order to prevent a possible build-up of residues. Early diagnosis and associated therapy overcome the necessity of intubation and prolonged intensive care.

A year's review of bacterial pneumonia at the central hospital of Lucerne, Switzerland

Community acquired pneumonia (CAP) remains an important cause of substantial morbidity and mortality in inhospital patients. We conducted a retrospective study of all patients hospitalised at our hospital with the diagnosis of bacterial pneumonia according to ICD-10 within one year. Of 360 identified charts, 335 met the requirements and were reviewed regarding risk factors, diagnosis, treatment, and overall mortality. The typical patient hospitalised with pneumonia was elderly (mean 68 years), male (60%), and suffered from comorbidities or predisposing factors (96.4%). A total of 72.8% of pneumonias were localized in the inferior lobes, and 21.1% had bilateral infiltrates. Etiologic agents were searched for in 297/335 patients (87.5%) and were found positive in 33.4%: of 169 blood cultures 9.5% were positive, of 150 sputum cultures taken 46.6% were positive, of 17 serologies taken 58.8% were positive, and of 9 pleural effusions analysed 22.2% were positive. Encapsulated bacteria were the most common found bacterial etiologies, namely Streptococcus pneumoniae (S. pneumoniae) in 30.9% of patients with known bacterial etiology, Haemophilus in 24.7%, and Klebsiella in 12.4%. Methicillin-resistant S. aureus was not found. The three most commonly used antibiotics were amoxicillin/clavulanic acid used in 77.3% of patients, clarithromycin (41.2%), and ceftriaxone (16.6%). Mean duration of treatment was 12.1 days. 245/335 (73.1%) patients had a favourable outcome, 16.7% (56/335) of patients had a protracted illness with delayed resolution (i.e. prolonged hospital stay, need for intensive care, intubation or several of these complications). Overall mortality in our unit was 8.6%.

A year's review of bacterial pneumonia at the central hospital of Lucerne, Switzerland

Community acquired pneumonia (CAP) remains an important cause of substantial morbidity and mortality in inhospital patients. We conducted a retrospective study of all patients hospitalised at our hospital with the diagnosis of bacterial pneumonia according to ICD-10 within one year. Of 360 identified charts, 335 met the requirements and were reviewed regarding risk factors, diagnosis, treatment, and overall mortality. The typical patient hospitalised with pneumonia was elderly (mean 68 years), male (60%), and suffered from comorbidities or predisposing factors (96.4%). A total of 72.8% of pneumonias were localized in the inferior lobes, and 21.1% had bilateral infiltrates. Etiologic agents were searched for in 297/335 patients (87.5%) and were found positive in 33.4%: of 169 blood cultures 9.5% were positive, of 150 sputum cultures taken 46.6% were positive, of 17 serologies taken 58.8% were positive, and of 9 pleural effusions analysed 22.2% were positive. Encapsulated bacteria were the most common found bacterial etiologies, namely Streptococcus pneumoniae (S. pneumoniae) in 30.9% of patients with known bacterial etiology, Haemophilus in 24.7%, and Klebsiella in 12.4%. Methicillin-resistant S. aureus was not found. The three most commonly used antibiotics were amoxicillin/clavulanic acid used in 77.3% of patients, clarithromycin (41.2%), and ceftriaxone (16.6%). Mean duration of treatment was 12.1 days. 245/335 (73.1%) patients had a favourable outcome, 16.7% (56/335) of patients had a protracted illness with delayed resolution (i.e. prolonged hospital stay, need for intensive care, intubation or several of these complications). Overall mortality in our unit was 8.6%.

Independent formation of DnaseI hypersensitive sites in the murine beta-globin locus control region

Mammalian beta-globin loci are composed of multiple orthologous genes whose expression is erythroid specific and developmentally regulated. The expression of these genes both from the endogenous locus and from transgenes is strongly influenced by a linked 15-kilobase region of clustered DNaseI hypersensitive sites (HSs) known as the locus control region (LCR). The LCR encompasses 5 major HSs, each of which is highly homologous among humans, mice, and other mammals. To analyze the function of individual HSs in the endogenous murine beta-globin LCR, we have used homologous recombination in embryonic stem cells to produce 5 mouse lines, each of which is deficient for 1 of these major HSs. In this report, we demonstrate that deletion of the conserved region of 5'HS 1, 2, 3, 4, or 5/6 abolishes HS formation at the deletion site but has no influence on the formation of the remaining HSs in the LCR. Therefore, in the endogenous murine locus, there is no dominant or initiating site whose formation must precede the formation of the other HSs. This is consistent with the idea that HSs form autonomously. We discuss the implications of these findings for current models of beta-globin regulation.

Treatment for human immunodeficiency virus with indinavir may cause relevant urological side-effects, effectively treatable by rehydration

OBJECTIVE

To explore the occurrence of, and diagnostic and therapeutic procedures for urological side-effects (e.g. micro- and macrohaematuria, and kidney stone formation) in individuals treated with indinavir for the human immunodeficiency virus (HIV).

PATIENTS AND METHODS

The study comprised a retrospective follow-up of 74 individuals infected with HIV-1 and who were treated with indinavir orally at a daily dose of 2.4 g. Data were collected at the outpatient department of our institution between March 1996 and November 1997.

RESULTS

Of the 74 individuals treated with indinavir, 15 (20%) had indinavir-related urological side-effects (19 episodes), most commonly dull flank pain and dysuria. Microhaematuria occurred in 16 of the 19 episodes. Four patients showed urinary tract distension ultrasonographically as a possible indirect sign of urolithiasis and one patient passed a kidney stone. In four patients treatment had to be stopped permanently, but in the remaining 11 patients treatment was continued. Some patients required dose reduction and/or interruption of treatment; only conservative therapeutic measures were required, consisting of rehydration (fluid intake >1.5 L/day) and analgesics.

CONCLUSIONS

Urological side-effects of indinavir may be apparent in 20% of patients so treated; some (5%) may require permanent withdrawal. In addition to a history and clinical examination, urine analysis and ultrasonography were the only diagnostic procedures required. Therapy is mainly conservative, using rehydration, analgesics and a brief discontinuation of therapy, according to the severity of the symptoms.

[Pruritus in liver disease: case report with discussion]

In this article a young woman presenting with generalized pruritus and elevated liver enzymes is described. The broad differential diagnosis is discussed. We observed the appearance of antimitochondrial antibodies (AMA) and the diagnosis of early primary biliary cirrhosis (PBC) could be established and documented histologically. The case report concludes with the discussion of the therapeutical possibilities for PBC.

[Anti-retroviral therapy and antiepileptics. Case report and discussion]

Therapy of HIV infection is changing rapidly as new drugs are introduced. Many patients with HIV infection require anticonvulsants for therapy or prophylaxis of seizures. Antiretroviral drugs, above all protease inhibitors, and anticonvulsants may cause interactions since they are metabolised through common hepatic pathways and may substantially modulate the activity of numerous cytochrome P450 isoenzymes. We describe known interactions between anticonvulsants and antiretroviral drugs and advise on possible combinations.

Reduced beta-globin gene expression in adult mice containing deletions of locus control region 5' HS-2 or 5' HS-3

To gain insights into the functions of individual DNA'se hypersensitive sites within the beta globin locus control region (LCR), we deleted the endogenous 5' HS-2 and HS-3 regions from the mouse germline using homologous recombination techniques. We demonstrated that the deletion of either murine 5' HS-2 or 5' HS-3 reduced the expression of the embryonic epsilon y and beta h1 globin genes minimally in yolk sac-derived erythrocytes, but that both knockouts reduced the output of the adult beta (beta-Major + beta-Minor) globin genes by approximately 30% in adult erythrocytes. When the selectable marker PGK-Neo cassette was retained within either the HS-2 or HS-3 region, a much more severe reduction in globin gene expression was observed at all developmental stages. PGK-Neo was shown to be expressed in an erythroid-specific fashion when it was retained in the HS-3 position. These results show that neither 5' HS-2 nor HS-3 is required for the activity of embryonic globin genes, nor are these sites required for correct developmental switching. However, each site is required for approximately 30% of the total LCR activity associated with adult beta-globin gene expression in adult red blood cells. Each site therefore contains some non-redundant information that contributes to adult globin gene function.

tbx6, a Brachyury-related gene expressed by ventral mesendodermal precursors in the zebrafish embryo

Classical embryology experiments have indicated the existence of dorsal-type and ventral-type mesoderms that arise as a consequence of mesoderm induction during vertebrate development. Here we report that the zebrafish tbx6 gene, a member of the Brachyury-related T-box family of genes, is exclusively expressed by ventral mesendoderm. Three observations link the expression of tbx6 to ventral mesoderm specification. First, the gene is initially expressed at the onset of gastrulation within a ventrolateral subpopulation of cells that express the pan-mesodermal gene, no tail (Brachyury). Second, the mesoderm-inducing factors activin and bFGF activate tbx6 expression in animal caps. Third, dorsalization of the mesendodermal precursor population following exposure of embryos to lithium ions causes down-regulation of tbx6 transcription. tbx6 is expressed transiently in the involuting derivatives of the ventral mesendoderm, which give rise to nonaxial mesodermal tissues; its expression is extinguished as tissue differentiation progresses. Transcription of tbx6 commences about an hour after initiation of expression of the pan-mesendodermal gene no tail and the organizer gene goosecoid. The dependence of tbx6 expression on no tail activity was examined in no tail mutant embryos. The activation of tbx6 transcription in ventral mesoderm does not depend on no tail gene activity. However, no tail appears to contribute to the maintenance of normal levels of tbx6 transcription and may be required for tbx6 transcription in the developing tail.

The zebrafish gene cloche acts upstream of a flk-1 homologue to regulate endothelial cell differentiation

The zebrafish cloche mutation affects both the endothelial and hematopoietic lineages at a very early stage (Stainier, D. Y. R., Weinstein, B. M., Detrich, H. W., Zon, L. I. and Fishman, M. C. (1995). Development 121, 3141–3150). The most striking vascular phenotype is the absence of endocardial cells from the heart. Microscopic examination of mutant embryos reveals the presence of endothelial-like cells in the lower trunk and tail regions while head vessels appear to be missing, indicating a molecular diversification of the endothelial lineage. Cell transplantation experiments show that cloche acts cell-autonomously within the endothelial lineage. To analyze further the role of cloche in regulating endothelial cell differentiation, we have examined the expression of flk-1 and tie, two receptor tyrosine kinase genes expressed early and sequentially in the endothelial lineage. In wild-type fish, flk-1-positive cells are found throughout the embryo and differentiate to form the nascent vasculature. In cloche mutants, flk-1-positive cells are found only in the lower trunk and tail regions, and this expression is delayed as compared to wild-type. Unlike the flk-1-positive cells in wild-type embryos, those in cloche mutants do not go on to express tie, suggesting that their differentiation is halted at an early stage. We also find that the cloche mutation is not linked to flk-1. These data indicate that cloche affects the differentiation of all endothelial cells and that it acts at a very early stage, either by directly regulating flk-1 expression or by controlling the differentiation of cells that normally develop to express flk-1. cloche mutants also have a blood deficit and their hematopoietic tissues show no expression of the hematopoietic transcription factor genes GATA-1 or GATA-2 at early stages. Because the appearance of distinct levels of flk-1 expression is delayed in cloche mutants, we examined GATA-1 expression at late embryonic stages and found some blood cell differentiation that appears to be limited to the region lined by the flk-1-expressing cells. The spatial restriction of blood in the ventroposterior-most region of cloche mutant embryos may be indicative of a ventral source of signal(s) controlling hematopoietic differentiation. In addition, the restricted colocalization of blood and endothelium in cloche mutants suggests that important interactions occur between these two lineages during normal development.

Plasma cholesteryl ester-triglyceride transfer protein. The catalytic domain is a low molecular weight proteolipid

The lipid transfer protein complex (LTC) isolated from human plasma by immunoaffinity chromatography transfers cholesteryl esters (CE), triglycerides, and phosphatidylcholine (PC) between lipoproteins in vitro. The molecular weight of this lipid transfer catalyst in sodium dodecyl sulfate-polyacrylamide gels was 65,000. When resolved on a gel filtration column by high performance liquid chromatography (HPLC), LTC was composed of fractions of high (greater than 150,000) to low (18,000) molecular weight, although sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of each fraction revealed bands at Mr 65,000 (major) and 52,000 (minor). The CE and triglyceride transfer activity of the low Mr HPLC fraction (1049 nmol of triglyceride/mg/h and 244 nmol of CE/mg/h) was significantly greater than that of the high Mr HPLC fraction (15-27 nmol of triglyceride/mg/h and 20-30 nmol of CE/mg/h). The PC transfer activity of the HPLC fractions was not determined. LTC proteins were separated by dialysis in acidified chloroform:methanol solution into dialysand and dialysate proteins. The dialysate contained a low Mr proteolipid, designated the catalytic domain Cd, which catalyzed CE and triglyceride transfer at equivalent rates (11.0 versus 9.5 mumol/mg/h, respectively). PC transfer activity was approximately 10% of these levels (1.5 mumol/mg/h). The dialysand consisted of a protein, designated the transfer protein TP, which facilitated CE (3.4 mumol/mg/h) preferentially over triglyceride and PC (1.0 mumol/mg/h) transfer, and a catalytically inactive protein, designated the heparin-binding domain Hd. We propose a model of the LTC protein (based on catalytic activities, monoclonal antibody reactivities, and heparin-binding capacities of the isolated proteins) in which both Hd (approximately 13 kDa) and Cd (approximately 3 kDa) originate from a single lipid transfer protein, TP.