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Altered immunity and metabolic profiles have been compared between bipolar depression (BD) and major depressive disorder (MDD). This study aimed at developing a composite predictor of appetite hormones and proinflammatory cytokines to differentiate BD from MDD.
Methods
This cross-sectional study enrolled patients with BD and those with MDD aged 20 to 59 years and displaying depressive episodes. Clinical characteristics (age, sex, body mass index, and depression severity), cytokines (C-reactive protein, interleukin [IL]-2, IL-6, tumor necrosis factor [TNF]-α, P-selectin, and monocyte chemoattractant protein), and appetite hormones (leptin, adiponectin, ghrelin, and insulin) were assessed as potential predictors using a classification and regression tree (CRT) model for differentiating BD from MDD.
Results
The predicted probability of a composite predictor of ghrelin and TNF-α was significantly greater (for BD: area under curve = 0.877; for MDD: area under curve = 0.914) than that of any one marker (all P > .05) to distinguish BD from MDD. The most powerful predictors for diagnosing BD were high ghrelin and TNF-α levels, whereas those for MDD were low ghrelin and TNF-α levels.
Conclusion
A composite predictor of ghrelin and TNF-α driven by CRT could assist in the differential diagnosis of BD from MDD with high specificity. Further clinical studies are warranted to validate our results and to explore underlying mechanisms.
To determine the impact of palliative care (PC) on end-of-life (EoL) care and the place of death (PoD) in children, adolescents, and young adults with life-limiting conditions.
Method
Eight online databases (PubMed, Medline, EMBASE, Cochrane Library, CINAHL, Airiti, GARUDA Garba Rujukan Digital, and OpenGrey) from 2010 to February 5, 2020 were searched for studies investigating EoL care and the PoD for pediatric patients receiving and not receiving PC.
Results
Of the 6,468 citations identified, 14 cohort studies and one case series were included. An evidence base of mainly adequate- and strong-quality studies shows that inpatient hospital PC, either with or without the provision of home and community PC, was found to be associated with a decrease in intensive care use and high-intensity EoL care. Conflicting evidence was found for the association between PC and hospital admissions, length of stay in hospital, resuscitation at the time of death, and the proportion of hospital and home deaths.
Significance of results
Current evidence suggests that specialist, multidisciplinary involvement, and continuity of PC are required to reduce the intensity of EoL care. Careful attention should be paid to the need for a longer length of stay in a medical setting late in life, and earlier EoL care discussion should take place with patients/caregivers, especially in regard to attempting resuscitation in toddlers, adolescents, and the young adult population. A lack of robust evidence has identified a gap in rigorous multisite prospective studies utilizing data collection.
Studies have suggested an association between metabolic and cerebrocardiovascular diseases and major depressive disorder (MDD). However, the risk of metabolic and cerebrocardiovascular diseases in the unaffected siblings of patients with MDD remains uncertain. Using the Taiwan National Health Insurance Research Database, 22,438 unaffected siblings of patients with MDD and 89,752 age-/sex-matched controls were selected and followed up from 1996 to the end of 2011. Individuals who developed metabolic and cerebrocardiovascular diseases during the follow-up period were identified. Compared with the controls, the unaffected siblings of patients with MDD had a higher prevalence of metabolic diseases, such as hypertension (5.0% vs. 4.5%, p = 0.007), dyslipidemia (5.6% vs. 4.8%, p < 0.001), and obesity (1.7% vs. 1.5%, p = 0.028), and cerebrocardiovascular diseases, such as ischemic stroke (0.6% vs. 0.4%, p < 0.005) and ischemic heart disease (2.1% vs. 1.7%, p < 0.001). Logistic regression analyses revealed that the unaffected siblings of patients with MDD were more likely to develop hypertension, dyslipidemia, ischemic stroke, and ischemic heart diseases during the follow-up period than the controls. Our study revealed a familial coaggregation between MDD and metabolic and cerebrocardiovascular diseases. Additional studies are required to investigate the shared pathophysiology of MDD and metabolic and cerebrocardiovascular diseases.
Family coaggregation of attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), bipolar disorder (BD), major depressive disorder (MDD) and schizophrenia have been presented in previous studies. The shared genetic and environmental factors among psychiatric disorders remain elusive.
Methods
This nationwide population-based study examined familial coaggregation of major psychiatric disorders in first-degree relatives (FDRs) of individuals with ASD. Taiwan's National Health Insurance Research Database was used to identify 26 667 individuals with ASD and 67 998 FDRs of individuals with ASD. The cohort was matched in 1:4 ratio to 271 992 controls. The relative risks (RRs) and 95% confidence intervals (CI) of ADHD, ASD, BD, MDD and schizophrenia were assessed among FDRs of individuals with ASD and ASD with intellectual disability (ASD-ID).
Results
FDRs of individuals with ASD have higher RRs of major psychiatric disorders compared with controls: ASD 17.46 (CI 15.50–19.67), ADHD 3.94 (CI 3.72–4.17), schizophrenia 3.05 (CI 2.74–3.40), BD 2.22 (CI 1.98–2.48) and MDD 1.88 (CI 1.76–2.00). Higher RRs of schizophrenia (4.47, CI 3.95–5.06) and ASD (18.54, CI 16.18–21.23) were observed in FDRs of individuals with both ASD-ID, compared with ASD only.
Conclusions
The risk for major psychiatric disorders was consistently elevated across all types of FDRs of individuals with ASD. FDRs of individuals with ASD-ID are at further higher risk for ASD and schizophrenia. Our results provide leads for future investigation of shared etiologic pathways of ASD, ID and major psychiatric disorders and highlight the importance of mental health care delivered to at-risk families for early diagnoses and interventions.
Studies have suggested the detrimental effects of obesity and systemic inflammation on the cognitive function of patients with bipolar or major depressive disorder. However, the complex associations between affective disorder, obesity, systemic inflammation, and cognitive dysfunction remain unclear.
Methods.
Overall, 110 patients with affective disorder (59 with bipolar I disorder and 51 with major depressive disorder) who scored ≥61 on the Global Assessment of Functioning and 51 age- and sex-matched controls were enrolled. Body mass index ≥25 kg/m2 was defined as obesity or overweight. Levels of proinflammatory cytokines—including interleukin-6, tumor necrosis factor (TNF)-α, and C-reactive protein (CRP)—were measured, and cognitive function was assessed using various methods, including the Wisconsin Card Sorting Test (WCST) and go/no-go task.
Results.
Patients with bipolar I disorder or major depressive disorder were more likely to be obese or overweight, had higher CRP and TNF-α levels, and had greater executive dysfunction in the WCST than the controls. TNF-α level (P < .05) but not affective disorder diagnosis or obesity/overweight was significantly associated with cognitive function deficits, although obesity/overweight and diagnosis were significantly associated with increased TNF-α level.
Conclusions.
Our findings may indicate that proinflammatory cytokines, but not obesity or overweight, have crucial effects on cognitive function in patients with bipolar I disorder or major depressive disorder, although proinflammatory cytokines and obesity or overweight were found to be strongly associated. The complex relationships between affective disorder diagnosis, proinflammatory cytokine levels, obesity or overweight, and cognitive function require further investigation.
Whether the first-degree relatives (FDRs) of patients with obsessive-compulsive disorder (OCD) have an increased risk of the major psychiatric disorders, namely schizophrenia, bipolar disorder, OCD, major depressive disorder (MDD), autism spectrum disorder (ASD), and attention deficit hyperactivity disorder (ADHD), remains unclear.
Methods
Using the Taiwan National Health Insurance Research Database with the whole population sample size (n = 23 258 175), 89 500 FDRs, including parents, offspring, siblings, and twins, of patients with OCD were identified in our study. The relative risks (RRs) of major psychiatric disorders were assessed among FDRs of patients with OCD.
Results
FDRs of patients with OCD had higher RRs of major psychiatric disorders, namely OCD (RR 8.11, 95% confidence interval (CI) 7.68–8.57), bipolar disorder (RR 2.85, 95% CI 2.68–3.04), MDD (RR 2.67, 95% CI 2.58–2.76), ASD (RR 2.38, 95% CI 2.10–2.71), ADHD (RR 2.19, 95% CI 2.07–2.32), and schizophrenia (RR 1.97, 95% CI 1.86–2.09), compared with the total population. Different familial kinships of FDRs, such as parents, offspring, siblings, and twins consistently had increased risks for these disorders. In addition, a dose-dependent relationship was found between the numbers of OCD probands and the risk of each major psychiatric disorder.
Conclusions
The FDRs, including parents, offspring, siblings, and twins, of patients with OCD have a higher risk of OCD, schizophrenia, bipolar disorder, MDD, ADHD, and ASD. The familial co-aggregation of OCD with OCD and other major psychiatric disorders was existent in a dose-dependent manner. Given the increased risks of psychiatric disorders, medical practitioners should closely monitor the mental health of the FDRs of patients with OCD.
Research suggests an association between metabolic disorders, such as type 2 diabetes mellitus (T2DM), and schizophrenia. However, the risk of metabolic disorders in the unaffected siblings of patients with schizophrenia remains unclear.
Methods
Using the Taiwan National Health Insurance Research Database, 3135 unaffected siblings of schizophrenia probands and 12,540 age-/sex-matched control subjects were included and followed up to the end of 2011. Individuals who developed metabolic disorders during the follow-up period were identified.
Results
The unaffected siblings of schizophrenia probands had a higher prevalence of T2DM (3.4% vs. 2.6%, p = 0.010) than the controls. Logistic regression analyses with the adjustment of demographic data revealed that the unaffected siblings of patients with schizophrenia were more likely to develop T2DM (odds ratio [OR]: 1.39, 95% confidence interval [CI]: 1.10–1.75) later in life compared with the control group. Moreover, only female siblings of schizophrenia probands had an increased risk of hypertension (OR: 1.47, 95% CI: 1.07–2.01) during the follow-up compared with the controls.
Discussion
The unaffected siblings, especially sisters, of schizophrenia probands had a higher prevalence of T2DM and hypertension compared with the controls. Our study revealed a familial link between schizophrenia and T2DM in a large sample. Additional studies are required to investigate the shared pathophysiology of schizophrenia and T2DM.
Bipolar disorder is a highly heritable mental illness that transmits intergeneratively. Previous studies supported that first-degree relatives (FDRs), such as parents, offspring, and siblings, of patients with bipolar disorder, had a higher risk of bipolar disorder. However, whether FDRs of bipolar patients have an increased risk of schizophrenia, major depressive disorder (MDD), autism spectrum disorder (ASD), and attention deficit hyperactivity disorder (ADHD) remains unclear.
Methods
Among the entire population in Taiwan, 87 639 patients with bipolar disorder and 188 290 FDRs of patients with bipolar disorder were identified in our study. The relative risks (RRs) of major psychiatric disorders were assessed among FDRs of patients with bipolar disorder.
Results
FDRs of patients with bipolar disorder were more likely to have a higher risk of major psychiatric disorders, including bipolar disorder (RR 6.12, 95% confidence interval (CI) 5.95–6.30), MDD (RR 2.89, 95% CI 2.82–2.96), schizophrenia (RR 2.64, 95% CI 2.55–2.73), ADHD (RR 2.21, 95% CI 2.13–2.30), and ASD (RR 2.10, 95% CI 1.92–2.29), than the total population did. These increased risks for major psychiatric disorders were consistent across different familial kinships, such as parents, offspring, siblings, and twins. A dose-dependent relationship was also found between risk of each major psychiatric disorder and numbers of bipolar patients.
Conclusions
Our study was the first study to support the familial coaggregation of bipolar disorder with other major psychiatric disorders, including schizophrenia, MDD, ADHD, and ASD, in a Taiwanese (non-Caucasian) population. Given the elevated risks of major psychiatric disorders, the public health government should pay more attention to the mental health of FDRs of patients with bipolar disorder.
Attention-deficit hyperactivity disorder (ADHD) increases the risk of suicidal behaviours through psychiatric comorbidities; however, a significant direct association has not been observed between ADHD and suicide attempts.
Aims
To evaluate the risk of suicide attempt in adolescents and young adults with ADHD.
Method
Using a nationwide, population-based insurance claims database, this longitudinal cohort study enrolled 20 574 adolescents and young adults with ADHD and 61 722 age- and gender-matched controls between 2001 and 2009. Any suicide attempt was identified from enrolment to 31 December 2011. The association between ADHD medications and the likelihood of suicide attempt was assessed.
Results
ADHD was an independent risk factor for any suicide attempt (hazard ratio = 3.84, 95% CI = 3.19–4.62) and repeated suicide attempts (hazard ratio = 6.52, 95% CI = 4.46–9.53). Subgroup analyses of men, women, adolescents and young adults demonstrated the same trend. Methylphenidate or atomoxetine treatment did not increase the risk of suicide attempt or repeated suicide attempts. Long-term methylphenidate treatment was associated with a significantly decreased risk of repeated suicide attempts in men (hazard ratio = 0.46, 95% CI = 0.22–0.97).
Conclusion
ADHD was a risk factor for suicide attempt and a stronger predictor of repeated suicide attempts, independent of comorbidities. Further investigation is warranted to explore the mechanism underlying the association between ADHD and suicidal behaviours.
A novel radio frequency identification tag antenna is composed of a resonant open-slot exciter and a dipole-type ground radiator. For a conjugate match to the Alien Higgs-4 chip impedance of 8−j149 Ω at 925 MHz, a quarter wavelength open-slot resonator embedded at the center of the dipole-type ground plane (130 × 18 mm2) was investigated and fabricated. Simple size adjustments and various loaded inductor of the open-slot resonator allow for easy control of the tag antenna resistance and inductive reactance, from which the chip impedance requirement can be easily obtained. The read range of the prototype antenna attached on a foam in the free space can reach more than 9 m, which has been tested for a radio frequency identification reader with 4.0-W of effective isotropic radiated power. Measurement data are in good agreement with simulation results.
This study modified the surfaces of three kinds of TiNi-based shape memory alloys (SMAs) by dry electrical discharge machining (EDM) in nitrogen (N2) and acetylene (C2H2) gas mixture. The effects of composition of the dielectric medium and work-piece on the machining performance and surface characteristics were investigated. Increasing the ratio of acetylene gas in gas mixture was beneficial for improving the material removal rate (MRR). However, adding a large amount of acetylene gas resulted in unstable discharge. A recast layer, comprising nitrides and carbides, which well adhered on the EDMed surface exhibited high hardness. Among Ti50Ni50, Ti50Ni49.5Cr0.5, and Ti40.5Ni49.5Zr10 SMA as a work-piece, Ti40.5Ni49.5Zr10 SMA has the lowest MRR owing to it possessed the highest melting temperature and thermal conductivity. The recast layer on Ti40.5Ni49.5Zr10 SMA, comprising zirconium nitride, exhibited the highest hardness and adhesion among all the SMAs. However, the high-hardness recast layer deteriorated the shape recovery of the SMA.
Previous evidence has shown positive associations between post-traumatic
stress disorder (PTSD) and hypertension, dyslipidaemia and diabetes
mellitus, which are all risk factors for stroke, but the role of PTSD in
the subsequent development of stroke is still unknown.
Aims
To investigate the temporal association between PTSD and the development
of stroke.
Method
Identified from the Taiwan National Health Insurance Research Database,
5217 individuals aged 18 years, with PTSD but with no history of stroke,
and 20 868 age- and gender-matched controls were enrolled between 2002
and 2009, and followed up until the end of 2011 to identify the
development of stroke.
Results
Individuals with PTSD had an increased risk of developing any stroke
(hazard ratio (HR) 3.37, 95% CI 2.44–4.67) and ischaemic stroke (HR =
3.47, 95% CI 2.23–5.39) after adjusting for demographic data and medical
comorbidities. Sensitivity tests showed consistent findings (any stroke
HR = 3.02, 95% CI 2.13–4.28; ischaemic stroke HR = 2.89, 95% CI
1.79–4.66) after excluding the first year of observation.
Conclusions
Individuals with PTSD have an increased risk of developing any stroke and
ischaemic stroke. Further studies are required to investigate the
underlying mechanisms.
Cancer is a serious public health problem worldwide, and its relationship
with affective disorders is not clear.
Aims
To investigate alcohol- and tobacco-related cancer risk among patients
with affective disorders in a large Taiwanese cohort.
Method
Records of newly admitted patients with affective disorders from January
1997 through December 2002 were retrieved from the Psychiatric Inpatient
Medical Claims database in Taiwan. Cancers were stratified by site and
grouped into tobacco- or alcohol-related cancers. Standardised incidence
ratios (SIRs) were calculated to compare the risk of cancer between those
with affective disorders and the general population.
Results
Some 10 207 patients with bipolar disorder and 9826 with major depression
were included. The risk of cancer was higher in patients with major
depression (SIR = 2.01, 95% CI 1.85–2.19) than in those with bipolar
disorder (SIR 1.39, 95% CI 1.26–1.53). The elevated cancer risk among
individuals ever admitted to hospital for affective disorders was more
pronounced in tobacco- and/or alcohol-related cancers.
Conclusions
Elevated cancer risk was found in patients who had received in-patient
care for affective disorders. They require holistic approaches to
lifestyle behaviours and associated cancer risks.
Findings on the association between the risk for developing bipolar disorder and the functions of the serotonin transporter-linked polymorphic region gene (5-HTTLPR) and dopamine D2 receptor gene (DRD2) variants are contradictory. One explanation for this is that a gender difference may exist for genetic contributions. We compared the gender-related main effects and the gene-to-gene interaction between serotonin transporter gene(SLC6A4) and DRD2 in adult male and female patients with bipolar I (BP-I) and bipolar II (BP-II) disorder. Patients with BP-I (n = 400) and BP-II (n = 493), and healthy controls (n = 442) were recruited from Taiwan's Han Chinese population. The genotypes of the 5-HTTLPR and DRD2 Taq-IA polymorphisms were determined using polymerase chain reaction−restriction fragment length polymorphism analysis. Logistic regression analysis showed a significant gender-specific association of the DRD2 A1/A1 and the 5-HTTLPR S/S, S/LG, and LG/LG (S+) (p = 0.01) genotypes in men with BP-I (p = 0.002 and 0.01, respectively) and BP-II (p = 0.001 and 0.007, respectively), but not in women. A significant interaction for the DRD2 A1/A1 and 5-HTTLPR S+ polymorphisms was also found only in men with BP-I and BP-II (p = 0.003 and 0.001, respectively). We provide preliminary evidence for a gender-specific effect of the SLC6A4 and DRD2 gene variants for the risk of BP-I and of BP-II. We also found gender-specific interaction between 5-HTTLPR and DRD2 Taq-IA polymorphisms in patients with bipolar disorder.
This study investigated the microstructure and machining characteristics of a Zr38.5Ti16.5Cu15.25Ni9.75Be20 bulk metallic glass (Zr-BMG) alloy machined using electro-discharge machining (EDM). After EDM, the hardening effect near the outer surface of the electro-discharge machined (EDMed) Zr-BMG alloy originated from the surface carbides of the recast layer, ZrC and TiC. The thickness of the recast layer, crater size, and the surface roughness increased with greater pulse energy. Furthermore, the EDM can generate a porous recast layer and convert the Zr-BMG alloy surface into a carbide surface, which is a potential method to fabricate biomaterials. Experimental results also show that the material removal rate of this alloy in the EDM process was significantly related to the pulse current IP and pulse duration τP. Many electro-discharge craters and recast materials were observed on the surface of the EDMed Zr-BMG alloy. The surface roughness of the EDMed Zr-BMG alloy was found to obey the empirical equation of Ra = β(IP × τP)α.
Memantine is a non-competitive N-methyl-d-asparate (NMDA) receptor antagonist with a mood-stabilizing effect. We investigated whether using valproic acid (VPA) plus add-on memantine to treat bipolar II disorder (BP-II) is more effective than using VPA alone (VPA + Pbo). We also evaluated, in BP-II patients, the association between the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism with treatment response to VPA + add-on memantine and to VPA + Pbo. In this randomized, double-blind, controlled 12 wk study, BP-II patients undergoing regular VPA treatments were randomly assigned to a group: VPA + Memantine (5 mg/day) (n = 115) or VPA + Pbo (n = 117). The Hamilton Depression Rating Scale (HDRS) and Young Mania Rating Scale (YMRS) were used to evaluate clinical response during week 0, 1, 2, 4, 8 and 12. The genotypes of the BDNF Val66Met polymorphisms were determined using polymerase chain reactions plus restriction fragment length polymorphism analysis. To adjust within-subject dependence over repeated assessments, multiple linear regression with generalized estimating equation methods was used to analyze the effects of the BDNF Val66Met polymorphism on the clinical performance of memantine. Both groups showed significantly decreased YMRS and HDRS scores after 12 wk of treatment; the differences between groups were non-significant. When stratified by the BDNF Val66Met genotypes, significantly greater decreases in HDRS scores were found in the VPA + memantine group in patients with the Val Met genotype (p = 0.004). We conclude that the BDNF Val66Met polymorphism influenced responses to add-on memantine by decreasing depressive symptoms in patients with BP-II.
Numerical simulations and laboratory experiments were jointly conducted to investigate a bathtub vortex under the influence of a protruding cylinder in a rotating tank. In the set-up, a central drain hole is placed at the bottom of the tank and a top-down cylinder is suspended from the rigid top lid, with fluid supplied from the sidewall for mass conservation. The cylinder is protruded to produce the Taylor column effect. The flow pattern depends on the Rossby number (
$\mathit{Ro}= U/ fR$
), the Ekman number (
$\mathit{Ek}= \nu / f{R}^{2} )$
and the height ratio,
$h/ H$
, where
$R$
is the radius of the cylinder,
$f$
is the Coriolis parameter,
$\nu $
is the kinematic viscosity of the fluid,
$h$
is the vertical length of the cylinder and
$H$
is the height of the tank. It is found appropriate to choose
$U$
to be the average inflow velocity of fluid entering the column beneath the cylinder. Steady-state solutions obtained by numerically solving the Navier–Stokes equations in the rotating frame are shown to have a good agreement with flow visualizations and particle tracking velocimetry (PTV) measurements. It is known that at
$\mathit{Ro}\sim 1{0}^{- 2} $
, the central downward flow surrounded by the neighbouring Ekman pumping forms a classic one-celled bathtub vortex structure when there is no protruding cylinder (
$h/ H= 0$
). The influence of a suspended cylinder (
$h/ H\not = 0$
) leads to several findings. The bathtub vortex exhibits an interesting two-celled structure with an inner Ekman pumping (EP) and an outer up-drafting motion, termed Taylor upwelling (TU). The two regions of up-drafting motion are separated by a notable finite-thickness structure, identified as a (thin-walled) Taylor column. The thickness
${ \delta }_{T}^{\ast } $
of the Taylor column is found to be well correlated to the height ratio and the Ekman number by
${\delta }_{T} = { \delta }_{T}^{\ast } / R= {(1- h/ H)}^{- 0. 32} {\mathit{Ek}}^{0. 095} $
. The Taylor column presents a barrier to the fluid flow such that the fluid from the inlet may only flow into the inner region through the narrow gaps, one above the Taylor column and one beneath it (conveniently called Ekman gaps). As a result, five types of routes along which the fluid may flow to and exit at the drain hole could be identified for the multi-celled vortex structure. Moreover, the flow rates associated with the five routes were calculated and compared to help understand the relative importance of the component flow structures. The weaker influence of the Taylor column effect on the bathtub vortex at
$\mathit{Ro}\sim 1$
or even higher
$\mathit{Ro}\sim 1{0}^{2} $
is also discussed.
The surface morphologies of AlGaN/AlN/GaN HEMT structures were examined by using the atomic force microscopy (AFM).These HEMT structures have been grown by metalorganic chemical vapor deposition (MOCVD) onto the sapphire (0001) substrates where the thicknesses of AlN interlayers were varied from 0 to 5 nm. After the growth of GaN buffer layer, the AlN intermediate and AlGaN top layers were subsequently deposited at 1130°C in an trimethylaluminum (TMAl) and ammonia (NH3) atmosphere. The surface of AlGaN layers shows the thick- and fine-thread patterns.
It was found that the root-mean-square (RMS) roughness of the samples with 0, 0.5, 2.5 and 5nm AlN interlayer thickness are 0.503, 0.534, 0.534 and 0.601nm, respectively. Although the cracks and rougher surfaces show that the qualities of AlGaN barrier layers have slightly degraded in the samples with thicker AlN layer. These phenomena could be attributed to the lattice mismatch and the growth temperature. In addition, the room-temperature two-dimensional electron gas (2DEG) mobility and density analysis were performed on the AlGaN surfaces and the measured results were discussed in detail.
Modulation of the cellular response by the administration of probiotic bacteria may be an effective strategy for preventing or inhibiting tumour growth. We orally pre-inoculated mice with probiotics Lactobacillus acidophilus NCFM (La) for 14 d. Subcutaneous dorsal-flank tumours and segmental orthotopic colon cancers were implanted into mice using CT-26 murine colon adenocarcinoma cells. On day 28 after tumour initiation, the lamina propria of the colon, mesenteric lymph nodes (MLN) and spleen were harvested and purified for flow cytometry and mRNA analyses. We demonstrated that La pre-inoculation reduced tumour volume growth by 50·3 %, compared with untreated mice at 28 d after tumour implants (2465·5 (sem 1290·4) v. 4950·9 (sem 1689·3) mm3, P < 0·001). Inoculation with La reduced the severity of colonic carcinogenesis caused by CT-26 cells, such as level of colonic involvement and structural abnormality of epithelial/crypt damage. Moreover, La enhanced apoptosis of CT-26 cells both in dorsal-flank tumour and segmental orthotopic colon cancer, and the mean counts of apoptotic body were higher in mice pre-inoculated with La (P < 0·05) compared with untreated mice. La pre-inoculation down-regulated the CXCR4 mRNA expressions in the colon, MLN and extra-intestinal tissue, compared with untreated mice (P < 0·05). In addition, La pre-inoculation reduced the mean fluorescence index of MHC class I (H-2Dd, -Kd and -Ld) in flow cytometry analysis. Taken together, these findings suggest that probiotics La may play a role in attenuating tumour growth during CT-26 cell carcinogenesis. The down-regulated expression of CXCR4 mRNA and MHC class I, as well as increasing apoptosis in tumour tissue, indicated that La may be associated with modulating the cellular response triggered by colon carcinogenesis.