Development of PK- and PBPK-based modeling tools for derivation of biomonitoring guidance values

There are numerous programs ongoing to analyze environmental exposure of humans to xenobiotic chemicals via biomonitoring measurements (e.g.: EU ESBIO, COPHES; US CDC NHANES; Canadian Health Measures Survey). The goal of these projects is to determine relative trends in exposure to chemicals, across time and subpopulations. Due to the lack of data, there is often little information correlating biomarker concentrations with exposure levels and durations. As a result, it can be difficult to utilize biomonitoring data to evaluate if exposures adhere to or exceed hazard/exposure criteria such as the Derived No-Effect Level values under the EU REACH program, or Reference Dose/Concentration values of the US EPA. A tiered approach of simple, arithmetic pharmacokinetic (PK) models, as well as more standardized mean-value, physiologically-based (PBPK) models, have therefore been developed to estimate exposures from biomonitoring results. Both model types utilize a user-friendly Excel spreadsheet interface. QSPR estimations of chemical-specific parameters have been included, as well as accommodation of variations in urine production. Validation of each model's structure by simulations of published datasets and the impact of assumptions of major model parameters will be presented.

The effects of metoprolol on hypoxia- and isoflurane-induced cardiac late-phase preconditioning

BACKGROUND

The detrimental effects of metoprolol on early-phase preconditioning (pc) have been proven. The late phase of pc is mediated via gene transcription and cyclooxygenase-2 (COX-2) was identified as one of the key mediators. The effect of metoprolol on this is yet unknown as is its effect on cellular energy metabolism and reactive oxygen species (ROS) creation.

METHODS

Cardiomyocytes from neonatal rats were cultured and randomly assigned to four pairs of treatment groups. In each pair, one group received metoprolol at a dose of 0.5 μg/ml medium. One pair served as a control; the others were subjected to 5 h of hypoxia 24 h after either hypoxia-induced, isoflurane-induced or no pc. Cell survival was measured with a redox indicator for cell metabolism. COX-2 transcription, ATP and ROS creation were measured.

RESULTS

Whereas both ischemic and isoflurane pc produced mild beneficial effects (48.8±6.0% and 48.2±7.8% of surviving cells, respectively) compared with unpreconditioned controls (35.9±7.9%, P<0.01 for both), adding metoprolol was detrimental for both kinds of pc (hypoxia: 31.5±3.5%; isoflurane: 25.7±3.8%, P<0.001) but not in the unpreconditioned group (39.4±4.9%). mRNA for COX-2 was up to 10-fold elevated in pc cells. This induction was suppressed by metoprolol. Hypoxic and isoflurane-induced pc showed significant differences in ATP balance and ROS generation.

CONCLUSION

Metoprolol abolishes the protection of both isoflurane- and hypoxia-induced late-phase pc in our model. This effect is accompanied by the blockade of COX-2 induction. The differences between hypoxic and isoflurane pc in ATP and ROS creation allow to presume distinct pathways on the mitochondrial level.

Nicotine dependence and depression among women smokers on methadone maintenance

OBJECTIVE

Tobacco use and depression are highly prevalent among methadone maintenance (MM) treatment programme participants. Our aim was to study the relationship between nicotine dependence, depression, and readiness to change smoking behaviour among women smokers in MM compared to women smokers attending a primary care clinic (Control group).

METHOD

We conducted a cross-sectional survey of 117 MM women smokers and 50 controls attending a family medicine clinic. All participants completed a computerized self-administered questionnaire, including demographic information, medical history, and drug and tobacco use history. Participants also completed the Fagerström Test for Nicotine Dependence (FTND), the Center for Epidemiologic Studies Depression Scale (CES-D), and the University of Rhode Island Change Assessment (URICA) instrument.

RESULTS

In this study 83% African American women had an average age of 43 years. Of the women smokers in the MM group, 95% were daily smokers compared to 46% in the Control group (P <0.05). The MM women smokers had CES-D scores of 22.5 compared to 14.7 in women of the Control group (P <0.0001). Women smokers in MM were significantly more likely to be depressed, more dependent on nicotine, and more ready to change their smoking behaviour.

CONCLUSIONS

Our data show a higher level of nicotine dependence and depression, and greater readiness to change among women smokers in methadone maintenance programmes compared to women smokers attending primary care clinics. Methadone treatment programmes present a need and an opportunity to assess and intervene in nicotine dependence and depression and in addressing and eliminating health disparities.

Ultrasensitive nanoparticle detection using a portable whispering gallery mode biosensor driven by a periodically poled lithium-niobate frequency doubled distributed feedback laser

We demonstrate a significant reduction in the limit of label-free detection of individual viral-sized nanoparticles in aqueous solution through the use of a frequency doubled telecom laser constructed from a distributed feedback-periodically poled lithium-niobate (DFB-PPLN) union. By driving a whispering gallery mode biosensor near a wavelength of 650 nm with this device we have detected real-time adsorption steps for particles 36 nm in radius with a signal to noise ratio of 8. The noise equivalent detection limit is ∼20 ag (17 nm radius). This new lower limit is attributed to the ultralow resonance wavelength noise [(Δλ(r))(rms)/λ(r)<10(-9)] associated with the use of the DFB-PPLN device.

Oestrogen regulates mitochondrial respiratory chain enzyme transcription in the mouse spinal cord

The regulation of mitochondrial energy metabolism is not only important for normal functioning of neurones, but also appears to be essential during acute damage and neurodegeneration in the central nervous system. This makes mitochondria an interesting regulatory target for therapeutic approaches. Oestrogen is well-recognised as a protective hormone in the central nervous system under pathological threats. In the present study, we analysed the influence of oestrogen on the expression of mitochondria-encoded genes and mitochondrial activity in spinal cord cells both in vitro and vivo. Hormone application increased the transcription of mitochondrial respiratory chain enzymes (MRCE). This effect was observed in cultured spinal cord neurones, where it was inhibited by a nuclear oestrogen receptor (ER) antagonist and mainly mediated by the activation of ERbeta. No effect of oestrogen was observed in cultured spinal cord astroglia. In addition, the mitochondrial transcription factor A and nuclear respiratory factor 1 were up-regulated by oestrogen in a similar way as MRCE in vitro, and ATP levels were elevated after the application of the specific ERbeta agonist 2,3-bis(4-hydroxyphenyl)-propionitrile in cultured spinal cord nerve cells. The exposure of young male mice to oestrogen yielded increased levels of MRCE transcripts in the spinal cord. These data clearly show that systemic application of oestrogen stimulates MRCE expression in the spinal cord and predominantly in neurones. Further studies are required to demonstrate the potency of oestrogen to counteract pathological damage by stabilising mitochondrial performance.

Whispering gallery mode bio-sensor for label-free detection of single molecules: thermo-optic vs. reactive mechanism

Thermo-optic and reactive mechanisms for label-free sensing of bio-particles are compared theoretically for Whispering Gallery Mode (WGM) resonators (sphere, toroid) formed from silica and stimulated into a first order equatorial mode. Although it has been expected that a thermo-optic mechanism should "greatly enhance" wavelength shift signals [A.M. Armani et al, Science 317, 783-787 (2007)] accompanying protein binding on a silica WGM cavity having high Q (10(8)), for a combination of wavelength (680 nm), drive power (1 mW), and cavity size (43 microm radius), our calculations find no such enhancement. The possible reasons for this disparity are discussed.

Mechanisms of nicotine-induced resistance to treatment with chemotherapy and radiotherapy

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Background: Nicotine (NIC), used for smoking cessation in cancer patients, is associated with increased tumor growth, angiogenesis, migration, invasion, growth factor production, and inhibition of apoptosis. The effects of NIC on the efficacy of radiotherapy (XRT) and/or chemotherapy (CT) have not been well characterized. Methods: A review of the literature produced a construct demonstrating that NIC generates more than 100 interactions with 40 proteins involved in tumor promotion and progression. From this construct, nicotinic acetylcholine receptors (nAChR), PI3K/Akt, and MAPK were identified as potential critical upstream targets modulating the effects of NIC. The effect of NIC on cell proliferation, cell survival, and protein activation was analyzed following CT, XRT, or chemoradiotherapy (CRT) in FaDu, A549, and H460 human cancer cell lines. Results: Proliferation measured with the WST-1 (tetrazolium) assay demonstrated that NIC increased proliferation following cisplatin, XRT, and cisplatin with XRT. NIC administration increased cell survival (colony survival) following XRT and following CT (cisplatin, doxorubicin, or etoposide) regimens in all cell lines. nAChR expression was verified in each cell line using Western blot. Non-specific inhibition of nAChR demonstrated no consistent effect on preventing NIC induced resistance to CT, XRT, or CRT; however, specific inhibition of the alpha-3- or alpha-7-nAChR had variable cell specific ability to prevent NIC induced resistance. Inhibition of MAPK activity (using PD98059) produced marked reduction in proliferation of all cell lines, but generally had no effect on NIC induced resistance. PI3K inhibition (using LY294002) generally increased sensitivity to cisplatin and XRT; however, some PI3K activity was required to achieve the full effect of cisplatin. NIC prevented LY294002 induced sensitization to chemotherapy with no effect on sensitization to XRT. Conclusions: Nicotine induces a broad spectrum of resistance to CT, XRT, and CRT and serves as an excellent model of treatment resistance. Mechanisms of NIC induced resistance to CT and XRT appear to diverge. These findings have significant clinical implications including smoking cessation, treatment efficacy, and outcomes research in cancer patients.

No significant financial relationships to disclose.

Whispering Gallery Mode Carousel--a photonic mechanism for enhanced nanoparticle detection in biosensing

Individual nanoparticles in aqueous solution are observed to be attracted to and orbit within the evanescent sensing ring of a Whispering Gallery Mode micro-sensor with only microwatts of driving power. This Carousel trap, caused by attractive optical gradient forces, interfacial interactions, and the circulating momentum flux, considerably enhances the rate of transport to the sensing region, thereby overcoming limitations posed by diffusion on such small area detectors. Resonance frequency fluctuations, caused by the radial Brownian motion of the nanoparticle, reveal the radial trapping potential and the nanoparticle size. Since the attractive forces draw particles to the highest evanescent intensity at the surface, binding steps are found to be uniform.

Homozygosity for DNASE2 single nucleotide polymorphisms in the 5′-regulatory region is associated with rheumatoid arthritis

Objectives:

To analyse the distribution of single nucleotide polymorphisms (SNPs) in the 5′-regulatory region of the DNASE2 gene, in patients with rheumatoid arthritis (RA) and healthy controls.

Methods:

A total of 906 patients with RA and 878 healthy controls were genotyped. All subjects were of German Caucasian origin. Genotyping was performed by real-time polymerase chain reaction technology, using a TaqMan 5′-allele discrimination assay.

Results:

In the initial analysis of unrelated case–control samples, three DNASE2 SNP alleles in the 5′-regulatory region were significantly more frequent in patients with RA than in healthy controls. The strongest association was found for the −1066G allele (33.5% vs 27.2%, p = 0.007, odds ratio (OR) = 1.34). Homozygosity for this allele (genotype GG) resulted in an additional increase in disease susceptibility (12.5% vs 6.2%, OR = 2.17). The association was replicated in a second case–control series of 483 patients with RA from two German multicentre studies and 474 controls. The association of DNASE2 −1066 GG homozygosity with RA was limited to rheumatoid factor-positive disease, but was not influenced by the presence of anti-cyclic citrullinated peptide or antinuclear antibodies. Similarly, the presence or absence of the HLA-DRB1 shared epitope or the RA-associated PTPN22 allele had no influence on this association.

Conclusions:

The association of SNPs in the 5′-regulatory region of the DNA degrading enzyme DNASE2 with RA implies a role for this enzyme in the pathogenesis of this autoimmune disease.

Oestrogen influences on mitochondrial gene expression and respiratory chain activity in cortical and mesencephalic astrocytes

The regulation of mitochondrial energy metabolism plays an essential role in the central nervous system (CNS). Abnormalities of the mitochondrial respiratory chain often accompany neurodegenerative diseases. This makes mitochondria a perfect target for strategies of cellular protection against toxic compounds and pathological conditions. Steroid hormones, such as oestrogen, are well-known to fulfil a protective role in the brain during ischaemic and degenerative processes. Because astrocytes function as the major energy supplier in the CNS, we have analysed oestrogen effects on the mitochondrial respiratory chain of this cell type. In our studies, we applied semi- and quantitative polymerase chain reaction analysis of gene expression and polarographic measurements of the respiratory chain activity of mitochondria. We observed that structural and functional properties were regulated dependent on the oestrogen exposure time and the brain region, but independent of the nuclear oestrogen receptors. We could demonstrate that long-term oestrogen exposure increases the subunit gene expression of respiratory chain complexes and the mitochondrial DNA content, thereby indicating an up-regulation of the amount of mitochondria per cell together with an increase of mitochondrial energy production. This could represent an important indirect mechanism by which long-term oestrogen exposure protects neurones from cell death under neurotoxic conditions. On the other hand, we observed short-term effects of oestrogen on the activity of mitochondrial, proton-pumping respiratory chain complexes. In astrocytes from the cortex, respiratory chain activity was decreased, whereas it was increased in astrocytes from the mesencephalon. An increased production of reactive oxygen species would be the consequence of an increased respiratory chain activity in mesencephalic astrocytes. This could explain the different efficiencies of oestrogen-mediated short-term protection in distinct brain regions, but also indicates the limitations for a therapeutic short-term application of oestrogen.

MicroParticle photophysics illuminates viral bio-sensing

The authors present an approach for specific and rapid unlabeled detection of a virus by using a microsphere-based whispering gallery mode sensor that transduces the interaction of a whole virus with an anchored antibody. They show theoretically that this sensor can detect a single virion below the mass of HIV. A micro-fluidic device is presented that enables the discrimination between viruses of similar size and shape.

Severe hypomyelination as the leading neuroradiological sign in a patient with fucosidosis

Fucosidosis is a rare autosomal recessive lysosomal storage disease, resulting from a deficiency of alpha- L-fucosidase. We report on the clinical and MRI findings of a girl with this disorder. Developmental delay became obvious at an age between 6 and 12 months. Cranial MRI at 16 months revealed severe global hypomyelination of both supra- and infratentorial white matter but no involvement of basal ganglia or thalamus. No clinical signs typical for fucosidosis were present at this time, and psychomotor development still progressed slowly. Since the age of 2 years, progressive neurological deterioration occurred. The diagnosis was established by severely decreased activity of alpha- L-fucosidase in plasma and leukocytes and confirmed by the detection of compound heterozygosity for two missense mutations of the FUCA1 gene. A follow-up imaging at the age of 4 years showed progression of neuroradiological abnormalities, particularly progressive involvement of basal ganglia and thalami. The course of this patient and her MRI findings enlarge the clinical and neuroradiological spectrum of fucosidosis.

Hirschsprung disease, associated syndromes and genetics: a review

Hirschsprung disease (HSCR, aganglionic megacolon) represents the main genetic cause of functional intestinal obstruction with an incidence of 1/5000 live births. This developmental disorder is a neurocristopathy and is characterised by the absence of the enteric ganglia along a variable length of the intestine. In the last decades, the development of surgical approaches has importantly decreased mortality and morbidity which allowed the emergence of familial cases. Isolated HSCR appears to be a non-Mendelian malformation with low, sex-dependent penetrance, and variable expression according to the length of the aganglionic segment. While all Mendelian modes of inheritance have been described in syndromic HSCR, isolated HSCR stands as a model for genetic disorders with complex patterns of inheritance. The tyrosine kinase receptor RET is the major gene with both rare coding sequence mutations and/or a frequent variant located in an enhancer element predisposing to the disease. Hitherto, 10 genes and five loci have been found to be involved in HSCR development.

[Efficacy, tolerance and acceptability of Incontex in spayed bitches with urinary incontinence]

A clinical study about efficacy and acceptance of Incontex in spayed bitches with urinary incontinence was performed. In a randomised, double-blinded study the efficacy and acceptance of Incontex (Dr. E. Gräub AG, Bern, Schweiz) in bitches with urethral sphincter incompetence due to spaying was evaluated under field conditions. The active ingredient of the Incontex Syrup is phenylpropanolamine (PPA), an alpha1-adrenergic agonist. The study was performed using 24 spayed, incontinent bitches. Over a first period of treatment of 30 days the bitches received either Incontex, at 1.5 mg/kg twice per day, or a placebo. In the second period of 30 days all 24 bitches were treated with Incontex at the recommended dose. Any changes in the incontinence compared with the situation before the study were evaluated.

RESULTS

Of 24 bitches 21 (88%) became continent and in 2 bitches (8%) urinary incontinence improved. In only 1 bitch (4%) the medication did have no effect. Five bitches (21%) showed side effects. The acceptance of Incontex was good.

CONCLUSION AND CLINICAL RELEVANCE

Incontex can be recommended as an efficient and well-tolerated medication for the treatment of bitches with urinary incontinence after spaying. The oral application of 1.5mg/kg BW phenylpropanolamine twice daily has been approved.

Human papillomavirus detection in self-collected vaginal specimens and matched clinician-collected cervical specimens

Human papillomavirus (HPV) detection is an integral part of cervical cancer screening, and a range of specimen collection procedures are being tested. Preliminary studies have found that the majority of women prefer self-collection of vaginal specimens instead of clinician-collected specimens of the cervix. The purposes of the current study were to explore the social and behavioral predictors of acceptance of self-collection of vaginal specimens among patients and to assess concordance in detection of HPV between clinician-collected cervical specimens and self-collected vaginal specimens. The study was conducted at a university family medicine clinic using a cross-sectional study design, and enrollment of women presenting for routine gynecological examination consecutively in a period of 1 year, self-administered questionnaires, collection of paired vaginal and cervical specimens for HPV DNA using Hybrid Capture 2, and cytologic analysis. Most women (79.8% [398/499]) agreed to collect vaginal specimens. In our study, 76.6% (216/282) African American women (AA), 88.1% (156/176) white non-Hispanic (WNH) women, and 63.4% (26/41) women of other races (P < 0.0001) agreed to self-collect vaginal specimens. HPV was detected in 16.0% (80/499) of clinician-collected cervical specimens and 26.1% (104/398) of self-collected vaginal specimens (P < 0.001). HPV detection was concordant in 13.4% (53/398) women in both cervical and vaginal specimens. Self-collection of vaginal specimens for HPV DNA detection is acceptable to most women presenting for routine gynecological examination. WNH women were more likely to obtain self-collected specimens than AA women. Vaginal specimens were more likely to be positive for HPV than were cervical specimens.

Comparative quantitative assessment of GnRH- and LH-receptor mRNA expression in the urinary tract of sexually intact and spayed female dogs

Ovariectomy interrupts the regulatory loop in the hypothalamus-pituitary-gonad axis, leading to a several-fold increase in gonadotropin levels. This rise in hormonal secretion may play a causal role in ovariectomy-related urinary incontinence. The purpose of this study was to examine the effect of ovariectomy in bitches on the expression of GnRH- and LH-receptors in the lower urinary tract, and assess the relationship between receptor expression and plasma gonadotropin concentrations. Plasma gonadotropins were measured in 37 client-owned bitches. Biopsies were harvested from the mid-ventral bladder wall in all dogs, and from nine further locations within the lower urinary tract in 17 of the 37 animals. Messenger RNA of the LH and GnRH receptors was quantified using RT-PCR with the TaqMan Universal PCR Master Mix. Gonadotropins were measured with a canine-specific FSH-immunoradiometric assay and LH-radioimmunoassay. The hierarchical mixed ANOVA model using MINITAB, Mann-Whitney U-test, unpaired means comparison and linear regressions using StatView were applied for statistical analyses. Messenger RNA for both receptors was detected in all biopsy samples. Age was negatively correlated to mRNA expression of the LH and the GnRH receptors. A relationship between the mRNA values and the plasma gonadotropin concentrations was not established. Evaluation of results within each of the biopsy locations revealed greater LH-receptor expression in the proximal second quarter of the urethra in spayed bitches than in intact bitches (P=0.0481). Increased mRNA expression of LH receptors in this location could possibly play a role in the decrease in closing pressure of the urethra following ovariectomy.

[Polysomnographic as a therapeutic aid in of psychogenic-functioning paraplegia]

The case of a patient with complete sensory and motor paraplegia for more than 1 year is presented. Leg movements were documented during sleep by video and electromyographic recording because a psychogenic cause of the symptoms was suspected. We showed the video to the patient, which illustrated that leg movements were possible. This resulted in fast and complete resolution of the neurologic symptoms. The patient has now been free of them for more than 3 years. This example suggests that the achievement of consciousness of normal motor function is a therapeutic approach for long-standing improvement of psychogenic paralysis.

Application of Intraoperative 3D Ultrasound During Navigated Tumor Resection

Intraoperative 3D ultrasound (3D-iUS) may enhance the quality of neuronavigation by adding information about brain shift and tumor remnants. The aim of our study was to prove the concept of 3D ultrasound on the basis of technical and human effects. A 3D-ultrasound navigation system consisting of a standard personal computer containing a video grabber card in combination with an optical tracking system (NDI Polaris) and a standard ultrasound device (Siemens Omnia) with a 7.5 MHz probe was used. 3D-iUS datasets were acquired after craniotomy, at different subsequent times of the procedure and overlaid with preoperative MRI. All patients underwent early postoperative 3D MRI including contrast agent within 24 hours after surgery. Acquisition of 3D iUS and the fusion with preoperative MRI was successful in 22/23 patients. The expenditure of time was at least 5 minutes for one intraoperative 3D US dataset. The technique was used three to seven times during surgery. The quality of the ultrasound images was superior in cases of metastasis, meningeoma and angioma over those in malignant glioma. Brain shifting ranged from 2-25 mm depending on localization and kind of tumor. A resection control was possible in 78%. All six neurosurgeons demonstrated a learning curve. The introduction of 3D ultrasound has increased the value of neuronavigation substantially, making it possible to update several times during surgery and minimize the problem of brain shift. Configuration of both the 3D iUS based on a standard ultrasound system and the MR navigation system is time- and especially cost-effective. Faster navigational datasets and more intuitive image-guided surgery enable novel and user-friendly display techniques.

A phase II study of intravenous (IV) milataxel (M) for the treatment of non-small cell lung cancer (NSCLC) refractory to platinum-based therapy

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Background: M (TL139, MAC-321) is a novel taxane that has shown activity when administered IV or orally in both taxane-resistant and susceptible nude mouse xenograft models. The current study is an open-label study in previously treated patients (pts) with locally advanced, metastatic, or recurrent NSCLC to determine response rate. Methods: Pts with cytologically or histologically confirmed NSCLC must have received 1 or 2 prior regimens including prior platinum, and may have received prior paclitaxel or docetaxel. Good performance status (ECOG 0 or 1), and adequate hematologic, hepatic and renal function were required. Pts with clinically active brain metastases were excluded. Pts were treated with M 35 mg/m2 as a 4 hr IV infusion every 3 weeks. The primary end point was objective response rate. Results: A total of 46 pts were treated: 21 (46%) female pts and 25 (54%) male pts. Mean age was 59 (range 41–85), ECOG was PS 0 in 13 (28%) pts, PS 1 in 31 (67%) pts and unknown in 2 (4%) pts. The number of prior chemotherapy regimens was > 1 in 21 (46%) pts. Twenty-five (54%) pts had one prior taxane and 7 (15%) pts had both paclitaxel and docetaxel previously. The median number of cycles was 3 (range 1–14). Nine (20%) pts required dose reduction. Five (11%) pts discontinued treatment due to adverse events. A total of 25 (54%) pts reported drug related grade 3 or 4 adverse events. Non-hematologic grade 3 or 4 drug-related events occurring in more than 1 pt included: neuropathy 4 (9%) pts, neutropenic fever 3 (7%) pts, arthralgia 2 (4%) pts. There was no treatment related mortality. Objective responses were confirmed in 4 (9%) pts (3 PR, 1 CR). Three pts with response (including pt with CR) had received prior docetaxel. PR duration was 175, 250, and 315 days. Pt with CR received 4 cycles of M and discontinued due to the CR. Pt remained in CR at day 504. Conclusions: Milataxel 35 mg/m2 as a 4 hr IV infusion every 3 weeks provided durable responses in heavily pretreated pts including pts who had previously received taxanes.

No significant financial relationships to disclose.

Antibodies against cyclic citrullinated peptide are associated with the DRB1 shared epitope and predict joint erosion in rheumatoid arthritis

OBJECTIVE

To evaluate antibodies against cyclic citrullinated peptide (anti-CCP antibodies) for their predictive value for severe joint destruction in rheumatoid arthritis (RA) and to examine their relationship to shared epitope (SE)-positive DRB1 alleles.

METHODS

Concentrations of anti-CCP antibodies were determined in sera from 126 patients with recent onset RA who had been followed prospectively for 6 yr. Progression of joint destruction was evaluated according to Larsen by scoring radiographs from the hand and feet taken at baseline and after 1, 2, 4 and 6 yr of observation. In addition to clinical parameters, the presence of SE-positive DRB1 alleles and of rheumatoid factor IgM and IgA was determined.

RESULTS

Anti-CCP antibodies were found more frequently and in higher concentrations in both DRB1*01-positive and in DRB1*04-positive SE-positive patients compared with SE-negative patients. Severe joint destruction as defined by a Larsen score in the upper third of the study population was predicted by positivity for anti-CCP antibodies, by the presence of SE-positive DRB1*04 alleles and by the presence of erosive disease at initial presentation. Multiple logistic regression analysis revealed that SE-positive DRB1*04 alleles and anti-CCP antibodies exerted a significant influence on the progression of joint destruction.

CONCLUSION

The association of anti-CCP antibodies with DRB1*01 and with SE-positive DRB1*04 alleles implies a functional role for the SE sequence motif. The determination of SE-positive DRB1*04 alleles and of anti-CCP antibody positivity facilitates the prediction of disease course and prognosis at the time of initial presentation.

Long-term Measurement of Gastric Motility using Passive Telemetry and Effect of Guar and Cellulose as Food Additives in Dogs

The suitability of passive telemetry for long-term measurements of gastric motility in two groups of dogs with different body weights, four Beagles and four Labrador Retrievers, was investigated. An intra-abdominal measuring device, with a pressure sensor and electrodes within the gastric wall, allowed the continuous recording of the intensity and frequency of contractions simultaneously with an electromyogram (EMG). In fasting dogs a typical inter-digestive motility cycle was reproducible. Within 15 min of feeding the integral of the pressure curve increased significantly, reaching its maximum 30-45 min post-prandially. The peak frequency also significantly increased immediately after feeding, reaching the maximum of 22 contractions per 5 min. The post-prandial motility patterns of the groups were significantly different. The pressure amplitudes of the Labradors were significantly higher and the peak frequencies significantly lower than the Beagles. The addition of guar to the food (2.5% or 5%) leads to a significant reduction of the intensity of the antral contractions, whereas the frequency was hardly affected. In comparison, the effect of cellulose, as a food additive (2.5% or 5%), was rather modest. The intensity of the post-prandial contractions, influenced by cellulose, was significantly increased in Beagles, but was decreased in Labradors. Passive telemetry has been proven to be a suitable method for the long-term investigation of the physiological gastric motility and the effect of food additives. The measuring device was still functional after removal 8 weeks later.

Effect of Anticholinergics (Atropine, Glycopyrrolate) and Prokinetics (Metoclopramide, Cisapride) on Gastric Motility in Beagles and Labrador Retrievers

The effect of atropine, glycopyrrolate, metoclopramide and cisapride on the antral motility was investigated in eight dogs (four Beagles and four Labradors) using passive telemetry. Both anticholinergics induced a pronounced and lasting reduction of the intensity and frequency of the contractions. A definite dose-related inhibition of the antral motility was seen in Beagles, similar for both active substances. Low doses of atropine (0.02 mg/kg BW i.m.) and glycopyrrolate (0.005 mg/kg BW i.m.) completely inhibited the gastric motility for at least 30 min, whereas higher doses (0.04 or 0.01 mg/kg BW) caused a cessation of activity for more than 3 h. In Labradors, the effects of both active substances were not so dose related and the effect of glycopyrrolate lasted at least 6 h, whereas the effect of atropine gradually decreased after 3 h. A distinct breed difference regarding the effect of the two prokinetics on the antral motility was also observed. In Beagles, the prokinetics, at a low dose (metoclopramide 0.3 mg/kg BW, cisapride 0.2 mg/kg BW), resulted in a significant increase in the amplitude integral. Higher doses (metoclopramide 0.6 mg/kg BW, cisapride 0.5 mg/kg BW) also increased the integrals of the pressure profiles, but significantly less than with the lower doses. In Labradors, both medications, mainly at higher doses, resulted in an increase of the contraction amplitudes. The low dose had no (cisapride) or only a transient effect (metoclopramide). The frequency of the antral contractions was not at all influenced by cisapride, and only in Beagles metoclopramide resulted in a dose-related increase. It is not clear if the different results in Labradors and Beagles are because of breed or body weight.