Infection rates in surgical neonates and infants receiving parenteral nutrition: a five-year prospective study

We performed a prospective, observational, cohort study on 208 surgical neonates and infants between 1992 and 1997. Surveillance cultures of the oropharynx and rectum were obtained at the start of parenteral nutrition and thereafter twice weekly. Blood cultures were taken on clinical indication only. Microbial translocation was diagnosed when the micro-organisms in the blood were not distinguishable from those carried in the oropharynx and/or rectum. Liver function was monitored weekly and when septicaemia was suspected. The incidence of septicaemia was 15%. The predominant micro-organisms (86%) were the low-level pathogens, coagulase-negative staphylococci and enterococci. Potential pathogens, including aerobic Gram-negative bacilli, were responsible for the remainder. Microbial translocation was responsible for 84% of septicaemic episodes in 76% of patients. The potential pathogens caused septicaemia significantly later than coagulase-negative staphylococci, at a time when liver function was significantly more impaired. In neonates and infants receiving parenteral nutrition, septicaemia is mainly a gut-derived phenomenon and requires novel strategies for prevention.

Reliability of measurement of angular movements of the pelvis and lumbar spine during treadmill walking

BACKGROUND AND PURPOSE

Angular movements of the pelvis and lumbar spine are thought to play an important role in walking. However, little is known about the amount of unpredictable variability in measurement of these movements during human walking. The aim of the present study was to determine the retest reliability of measuring the angular movements of the pelvis and lumbar spine during unimpaired familiarized treadmill walking.

METHOD

Retest reliability for 26 subjects without pathology was determined over a one-week interval. Subjects walked on a treadmill at self-selected or a slower speed while measurements of the three-dimensional angular movements were taken with a computer-based video analysis system.

RESULTS

The frontal plane movements of pelvic list and lumbar lateral flexion (relative to the pelvis) could be measured with high retest reliability at both self-selected and slow walking speeds (intraclass coefficient (ICC) (2, 1) > or = 0.81). In contrast, transverse and sagittal plane movements demonstrated moderate reliability at both speeds (0.37 < or = ICC (2, 1) < or = 0.76). Averaging the measurement over six strides resulted in increased observed reliability (self-selected walking speed summary Pearson's r = 0.71, slow walking speed summary Pearson's r = 0.79) compared to taking the measurement based on a single stride (self-selected walking speed summary Pearson's r = 0.63, slow walking speed summary Pearson's r = 0.67). Unlike pelvic and lumbar movements (relative to the pelvis), the measurement of lumbar movements (relative to the global reference frame) appeared to depend on whether subjects were walking at self-selected or slow speeds.

CONCLUSIONS

Measurement of pelvic list and lumbar lateral flexion (relative to the pelvis) could be applied with confidence to hypothesis testing about individuals or groups. Movements in the transverse and sagittal planes are unlikely to be appropriate in hypothesis testing about individuals and hence clinical practice, but may still have experimental applications in hypothesis testing about groups.

Characterization of the similarity of chemical compounds using electrospray ionization mass spectrometry and multivariate exploratory techniques

The applicability and usefulness of electrospray mass spectrometry to the analysis of a small data set of 52 synthetic substances to probe their molecular similarity/diversity has been demonstrated. The first stage was the reduction of the data by Principal Component Analysis (PCA), to visualize the structure of the data. Sequential Projection Pursuit (SPP) was applied to detect outlying objects. Hierarchical cluster analysis was employed to produce a dendrogram, using group-average linkage clustering. Finally, the cluster results of spectral data were compared with that of structural fingerprints and an expert's classification by using the similarity measure of Wallace.

Elective groin irradiation is not indicated for patients with adenocarcinoma of the rectum extending to the anal canal

PURPOSE

To evaluate the inguinal nodal failure rate in patients with locally advanced rectal cancer with anal canal involvement (ACI) treated with pelvic chemoradiation without elective inguinal irradiation.

METHODS AND MATERIALS

From 1990 and 1998, 536 patients received preoperative or postoperative chemoradiation for rectal cancer with curative intent; 186 patients had ACI (<4 cm from the anal verge on rigid proctoscopy). Two patients had positive inguinal nodes at presentation. Chemoradiation was delivered preoperatively (45 Gy in 25 fraction) or postoperatively (53 Gy in 29 fractions) with concurrent continuous infusion of 5-fluorouracil (300 mg/m2/d). The inguinal region was specifically irradiated in only 2 patients who had documented inguinal nodal disease.

RESULTS

The median follow-up was 50 months. Only 6 of 184 ACI patients who had clinically negative inguinal nodes at presentation developed inguinal nodal recurrence (5-year actuarial rate 4%); 4 of the 6 cases were isolated. Two patients underwent successful salvage. Only 1 died of uncontrolled groin disease. Local control was achieved in both patients with inguinal nodal disease at presentation, but both died of metastatic disease. Only 3 patients with tumors >4 cm from the verge developed inguinal recurrence (5-year actuarial rate <1%).

CONCLUSIONS

Inguinal nodal failure in rectal cancer patients with ACI treated with neoadjuvant or adjuvant chemoradiation is not high enough to justify routine elective groin irradiation.

Elective groin irradiation is not indicated for patients with adenocarcinoma of the rectum extending to the anal canal

PURPOSE

To evaluate the inguinal nodal failure rate in patients with locally advanced rectal cancer with anal canal involvement (ACI) treated with pelvic chemoradiation without elective inguinal irradiation.

METHODS AND MATERIALS

From 1990 and 1998, 536 patients received preoperative or postoperative chemoradiation for rectal cancer with curative intent; 186 patients had ACI (<4 cm from the anal verge on rigid proctoscopy). Two patients had positive inguinal nodes at presentation. Chemoradiation was delivered preoperatively (45 Gy in 25 fraction) or postoperatively (53 Gy in 29 fractions) with concurrent continuous infusion of 5-fluorouracil (300 mg/m2/d). The inguinal region was specifically irradiated in only 2 patients who had documented inguinal nodal disease.

RESULTS

The median follow-up was 50 months. Only 6 of 184 ACI patients who had clinically negative inguinal nodes at presentation developed inguinal nodal recurrence (5-year actuarial rate 4%); 4 of the 6 cases were isolated. Two patients underwent successful salvage. Only 1 died of uncontrolled groin disease. Local control was achieved in both patients with inguinal nodal disease at presentation, but both died of metastatic disease. Only 3 patients with tumors >4 cm from the verge developed inguinal recurrence (5-year actuarial rate <1%).

CONCLUSIONS

Inguinal nodal failure in rectal cancer patients with ACI treated with neoadjuvant or adjuvant chemoradiation is not high enough to justify routine elective groin irradiation.

Mutations of the secondary cell wall

It has not been possible to isolate a number of crucial enzymes involved in plant cell wall synthesis. Recent progress in identifying some of these steps has been overcome by the isolation of mutants defective in various aspects of cell wall synthesis and the use of these mutants to identify the corresponding genes. Secondary cell walls offer numerous advantages for genetic analysis of plant cell walls. It is possible to recover very severe mutants since the plants remain viable. In addition, although variation in secondary cell wall composition occurs between different species and between different cell types, the composition of the walls is relatively simple compared to primary cell walls. Despite these advantages, relatively few secondary cell wall mutations have been described to date. The only secondary cell wall mutations characterised to date, in which the basis of the abnormality is known, have defects in either the control of secondary cell wall deposition or secondary cell wall cellulose or lignin biosynthesis. These mutants have, however, provided essential information on secondary cell wall biosynthesis.

IL-7 differentially regulates cell cycle progression and HIV-1-based vector infection in neonatal and adult CD4+ T cells

Differences in the immunological reactivity of umbilical cord (UC) and adult peripheral blood (APB) T cells are poorly understood. Here, we show that IL-7, a cytokine involved in lymphoid homeostasis, has distinct regulatory effects on APB and UC lymphocytes. Neither naive nor memory APB CD4(+) cells proliferated in response to IL-7, whereas naive UC CD4(+) lymphocytes underwent multiple divisions. Nevertheless, both naive and memory IL-7-treated APB T cells progressed into the G(1b) phase of the cell cycle, albeit at higher levels in the latter subset. The IL-7-treated memory CD4(+) lymphocyte population was significantly more susceptible to infection with an HIV-1-derived vector than dividing CD4(+) UC lymphocytes. However, activation through the T cell receptor rendered UC lymphocytes fully susceptible to HIV-1-based vector infection. These data unveil differences between UC and APB CD4(+) T cells with regard to IL-7-mediated cell cycle progression and HIV-1-based vector infectivity. This evidence indicates that IL-7 differentially regulates lymphoid homeostasis in adults and neonates.

Total dose and frequency of administration critically affect success of nasal mucosal tolerance induction

AIMS

Nasal tolerance induction with autoantigens can effectively protect against a variety of experimental models of autoimmune disease. The aims of this study were to characterise the dosage and kinetics of inhibition of experimental autoimmune uveoretinitis (EAU) via intranasal administration of the uveitogenic antigen interphotoreceptor retinal binding protein (IRBP) in the murine model of IRBP induced EAU.

METHODS

B10RIII mice were tolerised by intranasal administration of IRBP either with a long term multiple low dose or a short term/high dosing regimen before subcutaneous immunisation with IRBP in complete Freund's adjuvant (CFA). On day 15 post-immunisation, mice were killed and eyes were removed for histological examination and quantification of inflammatory cell infiltration and degree of target organ (rod outer segment, ROS) destruction.

RESULTS

Nasal administration of multiple low doses of IRBP (1 microg or 3 microg IRBP per mouse per day for 10 days) significantly protected mice from IRBP induced EAU. Short term/high dose regimens were only effective when given either as a single or, at most, as two consecutive doses (40 microg per dose). Multiple doses in the range of 45-120 microg over 3 days afforded no protection.

CONCLUSIONS

These results indicate that both dose and frequency of intranasal antigen administration are pivotal to tolerance induction and subsequent suppression of T cell mediated autoimmune disease.

Ex vivo adenovirus mediated gene transfection of human conjunctival epithelium

AIM

To investigate the efficacy of "ex vivo" adenoviral vector mediated gene transfection of human conjunctival epithelial cell as a possible route for gene therapy for the distribution of anti-inflammatory agents for the potential treatment of immune mediated ocular inflammatory disorders.

METHODS

Human conjunctival cells (HCs) were cultured with various concentrations of recombinant adenoviral vectors carrying a reporter gene LacZ, GFP, or an immunomodulating cytokine vIL-10. vIL-10 in culture supernatant was detected by sandwich ELISA and biological activity was assessed by suppression of ConA stimulated splenocyte proliferation. X-gal and GFP expression was assessed by histochemistry.

RESULTS

The extent of adenoviral vector mediated transfer of both reporter genes and vIL-10 was dose dependent. LacZ expression could be detected for at least 50 day after infection with multiple of infection (MOI) 200. Following AdCMVvIL-10 transduction, vIL-10 protein expression occurred between 4-6 days post-transduction, and was maintained at a detectable level for at least 1 month. Secreted vIL-10 showed biological activity, significantly inhibiting Con A induced splenocyte proliferation. Additionally, transfection of HCs with two Adv vectors, one carrying LacZ and the other carrying GFP, resulted in co-expression within a single cell.

CONCLUSION

These results confirm previous successful adenoviral vector mediated gene transfer to HCs and further show that expression can be maintained. Furthermore the data show HCs can secrete biologically active vIL-10 that could be developed as a strategy to suppress immune mediated disorders. The successful co-transduction of HCs as described for other tissues, opens avenues to develop a multiple target gene therapy locally.

Lentivirus-mediated gene transfer in primary T cells is enhanced by a central DNA flap

Retroviral vectors have become the primary tool for gene delivery into hematopoietic cells, including T lymphocytes. Lentiviral vectors offer an advantage over Moloney murine leukemia virus (MuLV) vectors because of their ability to translocate across an intact nuclear membrane and integrate into the genome of nonproliferating cells. We have recently demonstrated that a central strand displacement event, controlled by the central polypurine tract (cPPT) and the central termination sequence (CTS), results in the formation of a central DNA flap which acts as a cis-determinant of HIV-1 genome nuclear import. Here, we show that insertion of this DNA determinant in a classical lentiviral vector resulted in a significantly higher level of transduction in activated T cells (51 +/- 12.7% versus 15 +/- 1.4%). CD4(+) and CD8(+) T cells were transduced at equivalent levels. Importantly, freshly isolated T cells stimulated only during the 12-h transduction period could be efficiently transduced with this new flap-containing lentiviral vector, but not with the parental lentiviral vector nor an MuLV vector. Transgene expression in the flap-containing lentiviral vector, under the control of either an internal cytomegalovirus or the elongation factor-1 alpha (EF1 alpha) promoter, was significant and expression remained elevated in resting T cells. Thus, this system allows stable expression of transgenes in T lymphocytes following a short ex vivo transduction protocol.

Evaluation of the effect of intravenous l-carnitine on quality of life in chronic hemodialysis patients

AIM

The aim of this study was to determine the effect of l-carnitine on quality of life (QOL) in chronic hemodialysis patients.

PATIENTS AND METHODS

This trial used a randomized, prospective, placebo-controlled, double-blind, crossover design. Inclusion criteria were patients who were older than 18 years, had been on dialysis for a minimum of one year, and had at least two of the following symptoms: intradialytic hypotension, muscle cramping, lack of energy, muscle weakness or myopathy, cardiomyopathy, or lack of responsiveness to erythropoietin (EPO). Patients were excluded if they were mentally incompetent to complete a QOL questionnaire. Sixteen patients were randomized to receive either l-carnitine (20 mg/kg) or placebo (normal saline) after each dialysis session for 12 weeks, followed by a 6-week washout, then the crossover therapy for 12 weeks. The Kidney Dialysis Questionnaire was the assessment tool used to evaluate QOL.

RESULTS

There was no significant effect of l-carnitine on QOL irrespective of treatment order. There were also no differences found in any of the secondary outcomes including incidence of muscle cramping, intradialytic hypotension, EPO requirements or hemoglobin. Adverse effects consisted of gastrointestinal symptoms, with a similar incidence between l-carnitine and placebo.

CONCLUSION

L-carnitine did not have a benefit on QOL in our patient population.

Insulin-like growth factor induces the survival and proliferation of myeloma cells through an interleukin-6-independent transduction pathway

Multiple myeloma (MM) is a B-cell neoplasia that is associated with an increased level of bone resorption. One important mediator of bone remodelling, insulin-like growth factor (IGF-I), has been shown to stimulate the proliferation of human myeloma cells. However, the mechanisms of action of IGF-I in these cells have not been determined. Using interleukin (IL)-6-dependent myeloma cell lines, we show IGF-I to be as potent a survival and proliferation factor as IL-6. We demonstrated that IGF-I functions independently of the IL-6 transducer gp130 and that these two cytokines have additive effects. Moreover, inhibition of the IGF-I pathway did not modulate the proliferative effect of IL-6. Accordingly, we found that IL-6 and IGF-I activated distinct downstream signalling molecules: IL-6 activated STAT3 phosphorylation, whereas IGF-I treatment resulted in the phosphorylation of IRS-1. Interestingly, these signalling pathways appear to converge as both cytokines activated the ras/MAPK pathway. Thus, IGF-I acts as a potent survival and proliferation factor for myeloma cells by stimulating an IL-6-independent signalling cascade. These data, together with the finding that, in vivo, IGF-I is normally expressed in close proximity to myeloma cells within the bone matrix, strongly suggest a role for this cytokine in the pathophysiology of multiple myeloma.

Highly efficient gene transfer in naive human T cells with a murine leukemia virus-based vector

Retroviral vectors based on the Moloney murine leukemia virus (MuLV) have become the primary tool for gene delivery into hematopoietic cells, but clinical trials have been hampered by low transduction efficiencies. Recently, we and others have shown that gene transfer of MuLV-based vectors into T cells can be significantly augmented using a fibronectin-facilitated protocol. Nevertheless, the relative abilities of naive (CD45RA(+)) and memory (CD45RO(+)) lymphocyte subsets to be transduced has not been assessed. Although naive T cells demonstrate a restricted cytokine profile following antigen stimulation and a decreased susceptibility to infection with human immunodeficiency virus, it was not clear whether they could be efficiently infected with a MuLV vector. This study describes conditions that permitted gene transfer of an enhanced green fluorescent protein-expressing retroviral vector in more than 50% of naive umbilical cord (UC) blood and peripheral blood (PB) T cells following CD3/CD28 ligation. Moreover, treatment of naive T cells with interleukin-7 resulted in the maintenance of a CD45RA phenotype and gene transfer levels approached 20%. Finally, it was determined that parameters for optimal transduction of CD45RA(+) T cells isolated from PB and UC blood differed: transduction of the UC cells was significantly increased by the presence of autologous mononuclear cells (24.5% versus 56.5%). Because naive T cells harbor a receptor repertoire that allows them to respond to novel antigens, the development of protocols targeting their transduction is crucial for gene therapy applications. This approach will also allow the functions of exogenous genes to be evaluated in primary nontransformed naive T cells.

IFN-gamma and LPS-mediated IL-10-dependent suppression of retinal microglial activation

PURPOSE

Human retinal microglia (MG) express constitutively major histocompatability complex (MHC) class II molecules and have thus been highlighted as potential immunocompetent antigen-presenting cells (APCs). This study was undertaken to characterize microglial expression of coaccessory molecules and the functional changes in antigen expression, cytokine production, migration, and phagocytosis after proinflammatory stimulation.

METHODS

Fresh donor retinal MG were obtained and isolated using a percoll density gradient technique. Phenotypic characteristics used for isolating rodent microglia were applied and modified. Coaccessory molecule expression and intracellular cytokine production were assessed using three-color flow cytometric analysis in both freshly isolated and interferon (IFN)gamma-lipopolysaccharide (LPS)-stimulated MG. Using five-millimeter retinal explants in culture, microglial migratory behavior, changes in cell surface antigen expression and phagocytic activity were documented.

RESULTS

MG could be clearly defined by the flow cytometric phenotype CD45low CD11b+ MHC class II+ CD86low CD40low. Freshly isolated MG showed mannose receptor-mediated uptake of dextran-FITC. MG migrated from explants, were adherent, and upregulated MHC class II expression. After IFNgamma-LPS stimulation of single-cell suspension of MG isolates, MHC class II expression was reduced, with an increase occurring in MG intracellular interleukin (IL)-10 and IL-10 production. Microglial migration from explants was reduced after IFNgamma-LPS stimulation.

CONCLUSIONS

These results highlight both phenotypic and behavioral characteristics that support an antigen-processing and -presenting capability of freshly isolated MG. However, proinflammatory stimulation with IFNgamma-LPS induces an IL-10-mediated downregulation of cell surface antigen expression and loss of migratory and phagocytic activity. Therefore, although equipped to act as APCs, MG are able to rapidly modulate their own function and behavior and as a result may have the potential to limit inflammation.

Retrovirus-mediated transduction of primary ZAP-70-deficient human T cells results in the selective growth advantage of gene-corrected cells: implications for gene therapy

Humans lacking the ZAP-70 protein tyrosine kinase present with an absence of CD8+ T cells and defective CD4+ T cells in the periphery. This severe combined immunodeficiency is fatal unless treated by allogeneic bone marrow transplantation. However, in the absence of suitable marrow donors, the development of alternative forms of therapy is desirable. Because lymphocytes are long-lived, it is possible that introduction of the wild-type ZAP-70 gene into CD4+ ZAP-70-deficient T cells will restore their immune function in vivo. Initial investigations evaluating the feasibility of gene therapy for ZAP-70 deficiency were performed using HTL V-I-transformed lymphocytes. Although transformation was useful in circumventing problems associated with the maintenance of ZAP-70-deficient T cells and low gene transfer levels, the presence of HTL V-I precluded any biological studies. Here, we investigated a retrovirus-mediated approach for the correction of primary T cells derived from two ZAP-70-deficient patients. Upon introduction of the wild-type ZAP-70 gene, TCR-induced MAPK activation, IL-2 secretion and proliferation were restored to approximately normal levels. Importantly, this gain-of-function was associated with a selective growth advantage of gene-corrected cells, thereby indicating the feasibility of a gene therapy-based strategy.

Maternal serum total activin A and follistatin in pregnancy and parturition

OBJECTIVE

To examine changes in maternal serum levels of activin A and follistatin during pregnancy and labour.

DESIGN

In three cross sectional and three longitudinal studies venous blood was collected from women during pregnancy, spontaneous labour, labour induction and prior to elective caesarean section for the measurement of activin A and follistatin.

SETTING

Monash Medical Centre, Clayton, Victoria, Australia.

POPULATION

One hundred and twenty-three women participated in a cross sectional study in pregnancy, 18 women in two longitudinal pregnancy studies, 36 women in a cross sectional labour study, nine women in a longitudinal study of labour induction. Ten women undergoing elective caesarean section were also studied.

METHODS

Activin A and follistatin were measured using two sensitive and specific enzyme-linked immunosorbent assays.

RESULTS

In the cross sectional study of pregnancy, mean (SEM) maternal serum activin A and follistatin levels increased towards term (2.4 ng/mL (0.3) and 1.8 ng/mL (0.3) in first trimester to 18.9 ng/mL (3.8) and 5.3 ng/mL (0.9) at term, respectively), but the longitudinal study revealed that levels plateau in the last three weeks of pregnancy (16.0 ng/mL (2.6) and 6.2 ng/mL (1.4) at 37 weeks and 16.6 ng/mL (3.5) and 6.2 ng/mL (0.5) before labour for activin A and follistatin, respectively). There was no difference in levels of activin A and follistatin between women delivered by caesarean section and labouring women at term (14.9 ng/mL (2.8) vs 11.0 ng/mL (0.93) and 5.95 ng/mL (0.67) vs 5.71 ng/mL (0.63), respectively) and levels of both proteins did not alter throughout spontaneous or induced labour.

CONCLUSIONS

We believe that these data argue against activin A playing an acute role in the initiation or regulation of human parturition.

Alternative antigen receptor (TCR) signaling in T cells derived from ZAP-70-deficient patients expressing high levels of Syk

ZAP-70-deficient patients present with nonfunctional CD4+ T cells in the periphery. We find that a subset of primary ZAP-70-deficient T cells, expressing high levels of the related protein-tyrosine kinase Syk, can proliferate in vitro. These cells (denoted herein as Syk(hi)/ZAP-70(-) T cells) provide a unique model in which the contribution of Syk to TCR-mediated responses can be explored in a nontransformed background. Importantly, CD3-induced responses, such as tyrosine phosphorylation of cellular substrates (LAT, SLP76, and PLC-gamma1), as well as calcium mobilization, which are defective in T cells expressing neither ZAP-70 nor Syk, are observed in Syk(hi)/ZAP-70(-) T cells. However, Syk(hi)/ZAP-70(-) T cells differ from control T cells with respect to the T cell antigen receptor (TCR)-mediated activation of the MAPK cascades: extracellular signal-regulated kinase activity and recruitment of the JNK and p38 stress-related MAPK pathways are diminished. This distinct phenotype of Syk(hi)/ZAP-70(-) T cells is associated with a profound decrease in CD3-mediated interleukin 2 secretion and proliferation relative to control T cells. Thus, ZAP-70 and Syk appear to play distinct roles in transducing a TCR-mediated signal.

Knee joint kinematics from familiarised treadmill walking can be generalised to overground walking in young unimpaired subjects

We studied the familiarisation time required for reliable sagittal-plane knee kinematics and temporal-distance gait measurements to be obtained from treadmill walking. We also studied whether knee kinematics and temporal-distance gait measurements obtained from familiarised treadmill walking can be generalised to overground walking. Sixteen subjects without pathology walked on a level overground walkway and on a treadmill. A motion measurement system was used to measure sagittal plane knee movements and temporal-distance gait parameters during overground and treadmill walking. Highly reliable knee kinematics and temporal-distance gait measurements [intraclass correlation coefficient (ICC)(2,1)>/=0.93] were found after 6 min of treadmill walking. These measurements, obtained after 6 min of treadmill walking, were highly correlated with and not significantly different to those of overground walking. Reliable measurements that can be generalised to overground walking, can be obtained from the treadmill within a familiarisation time of 6 min.

A comparison of the effects of olanzapine, haloperidol and placebo on cognitive and psychomotor functions in healthy elderly volunteers

The cognitive and psychomotor effects of olanzapine (3 mg) were compared with haloperidol (3 mg) and placebo in a double-blind, cross-over study. Fourteen healthy elderly volunteers (>65 years) were randomized to receive once daily medication for 4 days with a 16-day interval between treatment periods. Assessments of attention, memory and motor control were made prior to dosing on each day, at 2, 4, 6 and 8 h after dosing on days 1 and 4, and at 24 and 48 h following the last dose. On day 1, detectable impairment was observed at all time points in both groups. On day 4, haloperidol treated subjects showed increased impairment compared with day 1 and this was sustained throughout the 48 h of testing. Olanzapine treated subjects showed reduced day 4 deficit (compared with day 1), with no significant difference from placebo beyond 6 h post dose. These results suggest that both haloperidol and olanzapine have a measurable initial effect on cognitive and psychomotor function in elderly volunteers. However, acute effects associated with olanzapine decrease with repeated dosing and show substantial adaptation within 4 days. In contrast, effects seen with haloperidol are sustained and increase with repeated dosing over the same period.