Deep brain stimulation can suppress pathological synchronisation in parkinsonian patients

BACKGROUND

Although deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a highly effective therapeutic intervention in severe Parkinson's disease, its mechanism of action remains unclear. One possibility is that DBS suppresses local pathologically synchronised oscillatory activity.

METHODS

To explore this, the authors recorded from DBS electrodes implanted in the STN of 16 patients with Parkinson's disease during simultaneous stimulation (pulse width 60 μs; frequency 130 Hz) of the same target using a specially designed amplifier. The authors analysed data from 25 sides.

RESULTS

The authors found that DBS progressively suppressed peaks in local field potential activity at frequencies between 11 and 30 Hz as voltage was increased beyond a stimulation threshold of 1.5 V. Median peak power had fallen to 54% of baseline values by a stimulation intensity of 3.0 V.

CONCLUSION

The findings suggest that DBS can suppress pathological 11-30 Hz activity in the vicinity of stimulation in patients with Parkinson's disease. This suppression occurs at stimulation voltages that are clinically effective.

Trust and psychosis services: Bridging the gap between managing risk and meeting need

Introduction

Research suggests that trust is vital for quality healthcare and effective outcomes. Trust becomes necessary in conditions of vulnerability and uncertainty. These conditions may be especially relevant to the experience and treatment of mental illness - not least psychosis. There currently exists a paucity of research into trust and mental health services.

Aims and objectives

To develop an understanding of trust as it relates to psychosis services and their users. To identify practical contexts where trust may be particularly relevant and where research may inform policy, service organization and individual practice.

Method

Semi-structured interviews were carried out with 21 stakeholders - service-users, professionals, managers, carers - across 3 different types of service working with people experiencing psychosis: early intervention; assertive outreach; and a more standard community mental health team.

Findings

Trust appears to be salient and yet problematic for mental health services, not least in terms of approachability, disclosure and cooperation with treatment programmes. Organizing services around understandings of trust, rather than risk, may be more effective both at meeting need and managing risk.

Conclusions

Through an improved understanding of trust and its effect on the engagement of service-users, there are clear potential benefits for mental health services through an enhanced ability to facilitate access and develop effective cooperation towards healthcare outcomes.

Germline mutations in CDH1 are infrequent in women with early-onset or familial lobular breast cancers

BACKGROUND

Germline mutations in CDH1 are associated with hereditary diffuse gastric cancer; lobular breast cancer also occurs excessively in families with such condition.

METHOD

To determine if CDH1 is a susceptibility gene for lobular breast cancer in women without a family history of diffuse gastric cancer, germline DNA was analysed for the presence of CDH1 mutations in 318 women with lobular breast cancer who were diagnosed before the age of 45 years or had a family history of breast cancer and were not known, or known not, to be carriers of germline mutations in BRCA1 or BRCA2. Cases were ascertained through breast cancer registries and high-risk cancer genetic clinics (Breast Cancer Family Registry, the kConFab and a consortium of breast cancer genetics clinics in the United States and Spain). Additionally, Multiplex Ligation-dependent Probe Amplification was performed for 134 cases to detect large deletions.

RESULTS

No truncating mutations and no large deletions were detected. Six non-synonymous variants were found in seven families. Four (4/318 or 1.3%) are considered to be potentially pathogenic through in vitro and in silico analysis.

CONCLUSION

Potentially pathogenic germline CDH1 mutations in women with early-onset or familial lobular breast cancer are at most infrequent.

Abstract P3-10-23: Caveolin 1 and Patient Outcomes in Breast Cancer

Introduction: Caveolin 1 (Cav1) protein is a structural component of caveolae in cell membranes and is also present in the cell cytoplasm, nucleus and extracellular milieu. It regulates multiple cellular processes and has been reported to both positively and negatively effect tumour progression. In normal and malignant breast tissue Cav1 is immunohistochemically expressed in myoepithelial and stromal cells but rarely in luminal epithelial or breast cancer cells. Recent reports have correlated Cav1 expression in the stromal tumour microenvironment with lower tumor stage, grade and improved prognosis. This suggests a separate role for Cav 1 in influencing tumour behaviour by regulating the tumour microenvironment. Our aim was to further investigate the role of Cav1 in breast cancer by for the first time analysing its expression by reverse phase protein array(RPPA). Methods: We examined expression levels of Cav1 in 52 breast cancer cell lines and a large human early breast cancer cohort(n=712) with cancer cells composing 70% of the macrodissected breast cancer specimens used. Data was recorded when available for each case on standard clinical, pathological and survival endpoints. We examined the effect of Cav1 expression on tumour biology and patient survival. Results: High levels of Cav1 expression in breast cancer cell lines was strongly correlated with a TN phenotype (P<0.001). Cav 1 expression was more strongly associated with the stromal subtype rather than basal subtype of TN cell lines (p=0.02).

In contrast, in human tumour tissue high levels of Cav1 correlated with the hormone receptor positive(ER) phenotype. There was also an association between Cav 1 expression and lower grade (P<0.001), lower T stage (P<0.001) and lower N stage (P<0.001).

Cav 1 was significantly associated with improved relapse-free (RFS) and overall survival (OS) in the human cohort. On multivariate(MV) analysis Cav1 was associated with OS(HR 0.91/95% CI 0.82-1/p=0.05) but not RFS. In the subset of ER patients who only received adjuvant tamoxifen (n=199) Cav1 was also significantly associated with improved RFS and OS. MV analysis again showed this correlation to remain for OS (HR 0.81/95% CI 0.65-1/p=0.05) but not for RFS. In the TN subset (n=161) Cav1 expression did not have any survival impact. Discussion: Our results show different expression patterns of Cav1 in vitro and in vivo. TN tumors are thought to originate from the myoepithelial or stromal component of breast tissue which may explain the high levels of Cav1 in this subgroup of breast cancer cell lines. On the other hand, human tumour tissue showed an association between high Cav1 levels and ER tumours. Analysis of these macrodissected samples likely included stromal tissue surrounding the epithelial tumour cells which may explain this discrepancy.

Our data also show a correlation between high in vivo levels of Cav1 and less aggressive tumours with improved prognosis. On MV analysis Cav1 was an independent predictor of outcome in the whole cohort and in the ER subset treated with adjuvant tamoxifen only. Expression of stromal Cav1 measured by RPPA may again partly explain these findings. Further analysis with fully microdissected human breast tissue and immunohistochemical analysis of both stromal and cancer cell Cav1 expression is planned.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-10-23.

Inhibition of sphingosine 1-phosphate lyase for the treatment of rheumatoid arthritis: discovery of (E)-1-(4-((1R,2S,3R)-1,2,3,4-tetrahydroxybutyl)-1H-imidazol-2-yl)ethanone oxime (LX2931) and (1R,2S,3R)-1-(2-(isoxazol-3-yl)-1H-imidazol-4-yl)butane-1,2,3,4-tetraol (LX2932)

Sphingosine 1-phosphate lyase (S1PL) has been characterized as a novel target for the treatment of autoimmune disorders using genetic and pharmacological methods. Medicinal chemistry efforts targeting S1PL by direct in vivo evaluation of synthetic analogues of 2-acetyl-4(5)-(1(R),2(S),3(R),4-tetrahydroxybutyl)-imidazole (THI, 1) led to the discovery of 2 (LX2931) and 4 (LX2932). The immunological phenotypes observed in S1PL deficient mice were recapitulated by oral administration of 2 or 4. Oral dosing of 2 or 4 yielded a dose-dependent decrease in circulating lymphocyte numbers in multiple species and showed a therapeutic effect in rodent models of rheumatoid arthritis (RA). Phase I clinical trials indicated that 2, the first clinically studied inhibitor of S1PL, produced a dose-dependent and reversible reduction of circulating lymphocytes and was well tolerated at dose levels of up to 180 mg daily. Phase II evaluation of 2 in patients with active rheumatoid arthritis is currently underway.

Knowledge, awareness and compliance with universal precautions among health care workers at the University Hospital of the West Indies, Jamaica

BACKGROUND

Universal precautions are not well understood or implemented by health care practitioners, though crucial in the prevention and transmission of blood-borne pathogens like HIV.

OBJECTIVE

To assess knowledge, awareness and compliance of universal precautions among health care workers at the University Hospital of the West Indies, Jamaica.

METHODS

A cross-sectional survey was conducted in September and October 2007. A 28-item self-administered questionnaire was provided to 200 health care workers including medical doctors, medical technologists, nurses and porters to assess their knowledge, awareness and practice towards universal precautions.

RESULTS

Almost two-thirds (64.0%) of the respondents were very knowledgeable of universal precautions with significantly more females (75.4%) than males (42.9%) (p<0.0001). More nurses (90.0%), medical doctors (88.0%) and medical technologists (70%) were very knowledgeable of universal precautions (p<0.0001). More respondents (92.9%) who were employed in the health sector for 16 years and over reported high levels of awareness of universal precautions than those who were employed for less than five years (p<0.0001). 28.6% of males and only 6.2% of females reported that they do not use protective gear. More nurses reported frequent use of protective equipment followed by medical technologists and medical doctors (p<0.0001).

CONCLUSION

There was adequate knowledge and a fair level of awareness among medical doctors, medical technologists, and nurses towards universal precautions.

Effective management of accelerated phase myelofibrosis with low-dose splenic radiotherapy

The main cause of hepatosplenomegaly in primary (PMF), post polycythemia vera (post-PV MF), and post essential thrombocythemia (post-ET MF) myelofibrosis (MF) is extramedullary hematopoiesis (EMH). Drug-refractory symptomatic splenomegaly in MF is usually managed by splenectomy or involved-field radiotherapy. The latter is most effective in the treatment of MF-associated bone pain and pulmonary hypertension.Our previous experience with hepatosplenic radiotherapy in MF showed efficacy in the majority of treated patients but its utility was limited by the transient nature of its benefit and the occurrence of treatment-related pancytopenia. In an effort to address these issues,we have adopted an induction-maintenance treatment strategy that utilizes lower radiation doses-induction with 100 cGy total in four daily doses of 25 cGy and maintenance with either the same or lower intensity regimen. Herein, we report our most recent experience using this treatment plan in two cases, who in addition to their expected response from the standpoint of splenomegaly, also unexpectedly showed a marked response of their underlying accelerated phase disease,including clearance of circulating blasts and basophilia.

High frequencies of leukemia stem cells in poor-outcome childhood precursor-B acute lymphoblastic leukemias

In order to develop a xenograft model to determine the efficacy of new therapies against primary human precursor-B acute lymphoblastic leukemia (ALL) stem cells (LSCs), we used the highly immunodeficient non-obese diabetic (NOD).Cg-Prkdc(scid)IL2rg(tmlWjl)/SzJ (NOD-severe combined immune deficient (scid) IL2rg(-/-)) mouse strain. Intravenous transplantation of 2 of 2 ALL cell lines and 9 of 14 primary ALL cases generated leukemia-like proliferations in recipient mice by 1-7 months after transplant. Leukemias were retransplantable, and the immunophenotypes, gene rearrangements and expression profiles were identical or similar to those of the original primary samples. NOD-scid mice transplanted with the same primary samples developed similar leukemias with only a slightly longer latency than did NOD-scid-IL2Rg(-/-) mice. In this highly sensitive NOD-scid-IL2Rg(-/-)-based assay, 1-100 unsorted primary human ALL cells from five of five tested patients, four of whom eventually experienced leukemia relapse, generated leukemias in recipient mice. This very high frequency of LSCs suggests that a hierarchical LSC model is not valuable for poor-outcome ALL.

An historical perspective on efforts to treat transmissible spongiform encephalopathy

Efforts to treat transmissible spongiform encephalopathy (TSE) date back to the middle of the 20(th) century. Early studies were colored by the belief that TSE was caused by a 'slow' or 'unconventional' virus, and a variety of anti-infective agents, together with scores of drugs drawn at random from other categories, predictably failed to provide any benefit, apart from polyanionic compounds and polyene antibiotics that prolonged the incubation period of disease in experimental animals. With the discovery in the 1980's that TSE apparently results from the malformation of a normal host protein, attempts at treatment could at last be rationally focused, and can be broadly categorized as genetic, immunologic, and pharmacologic. Genetic 'neutralization' of the pathogen has shown excellent results in experimental animals but is unlikely to be useful until the same kind of engineering can be effectively applied to humans. Immunologic methods to accomplish the same result have also shown some success in animals, but forays into the pharmacologic realm have been generally disappointing. Most reported 'successes' have been limited to prolonged incubation periods, and even then only when the treatment was begun at or near the time of infection, which is not known in sporadic or familial human disease. However, a few methods using the more rigorous model of treatment nearer the onset of symptomatic disease have begun to yield promising results that, if coupled with a practical screening test for pre-clinical infection, would be the optimal strategy for prevention or cure.

A Single Nucleotide Polymorphism in Steroid Receptor Coactivator-1 Diminishes the Coactivation of ERα

Estrogen signaling is critical in the progression of a large fraction of breast cancers as well as in the maintenance of bone mineral density. Generally speaking, Tamoxifen, a selective estrogen receptor modulator (SERM), blocks estrogen signaling in the breast by acting as an antagonist at the same time as promoting estrogen signaling in the bone by acting as an agonist. This tissue specific action characteristic of SERMs is thought to be maintained by the balance of levels and/or activities of estrogen receptor (ER) coregulators. Because of this critical role, single nucleotide polymorphisms (SNPs) in ER coregulators could have a dramatic effect on tamoxifen action.Previous studies have implicated steroid receptor coactivator-1 (SRC-1) as a critical coregulator for the mixed antagonist-agonist specificity of tamoxifen. By using an ERE-Tk-Luciferase transient transfection assay, we have shown that a SNP causing the amino acid change P1272S in SRC-1 dramatically reduces its ability to coactivate ERα.To assess the impact of this SNP on tamoxifen action in breast cancer we decided to genotype the SRC-1 P1272S SNP in a breast tumor DNA bank. This bank was generated from archived tumors from individuals either exclusively receiving adjuvant tamoxifen or not receiving any adjuvant therapy following surgical resection. Currently, the bank is composed of 1000 samples divided equally among the two groups. Genotyping for the SRC-1 P1272S SNP is currently underway.Since SRC-1 has also been shown to be important in proper maintenance of bone mineral density (BMD) and in the agonist action of tamoxifen in certain tissues, we also assessed the impact of the P1272S SNP in bone following tamoxifen therapy. We genotyped breast cancer patients exclusively receiving tamoxifen therapy (i.e. no chemotherapy, no radiation) who had lumbar (n=113) and/or hip (n=108) BMD scans before and after 12 months of tamoxifen therapy. We observed a significant association between the SNP and bone loss; women harboring the P1272S SNP lost 6.4% of their lumbar BMD, while women with the WT version lost only 1.3% of their lumbar BMD.These findings illustrate the critical role of SRC-1 in tamoxifen action in bone, and potentially other hormone responsive tissues. Studies are ongoing to decipher the mechanism for decreased coactivation activity of the SNP, and also to extend the clinical association studies.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 66.

PRSS23 Is an Estrogen Induced, AP-1-Dependent Gene in MCF-7 Breast Cancer Cells

Background: Breast cancer is the second leading cause of cancer related deaths among women in the United States. While estrogens have been documented to play a role in the etiology and progression of breast cancer through a “classical” pathway by binding to the estrogen receptor which in turn binds at estrogen response elements (EREs) within gene promoters, the mechanisms by which estrogens stimulate breast cancer growth are poorly understood. Estrogens have also been shown to stimulate transcription by interacting with other transcription factors such as AP-1, SP-1 or NFκB through a “non-classical” pathway. We have shown previously that estrogen can stimulate breast cancer cell growth by activating gene expression independently of ERα binding directly to the DNA. We also previously used microarray analysis to identify a set of genes that are induced by estrogen and that are dependent on AP-1 for their induction. One of these ER and AP-1-dependent genes is PRSS23. We hypothesized that many growth regulatory estrogen-induced genes are induced through these non-classical pathways via crosstalk with the AP-1 transcription factor. To test this hypothesis, we investigated the role of AP-1 in the up-regulation of one estrogen responsive gene, PRSS23.Methods: qPCR was used to establish the estrogen and AP-1 responsiveness of PRSS23 following treatment of MCF7 cells with 1nM estradiol (E2) and 100nM TPA respectively. Antibodies specific to ERα (Santa Cruz), cJun/AP-1 (Oncogene), cFos (Santa Cruz), and pan-Fos (Santa Cruz), with rabbit IgG (Santa Cruz) as a control, were used in chromatin immunoprecipitation (ChIP) assays to identify the transcription factors recruited to the PRSS23 promoter after estrogen stimulation. siRNA knockdown studies were used to assess the requirement of specific transcription factors for estrogen-induction of PRSS23.Results: qPCR analysis confirmed that PRSS23 mRNA levels are induced following both E2 and TPA stimulation. These studies also demonstrated that the induction of PRSS23 by estrogen mRNA is reduced by expression of a dominant-negative form of cJun (TAM67), showing that estrogen induction of PRSS23 is AP-1-dependent. siRNA experiments identified that members of both ERα and AP-1 (cFos and Jun) are required for estrogen induction of PRSS23 mRNA expression. ChIP assays demonstrated that estrogen induces ERα recruitment to an upstream enhancer region. We are now investigating the location of recruitment of the AP-1 transcription factors to the PRSS23 promoter after estrogen stimulation.Conclusion: Our results demonstrate that PRSS23 is a “non-classical”, estrogen-induced gene that requires ERα and AP-1 family members for its induction by estrogen. The mechanism by which ER and these AP-1 proteins cooperate to induce the expression of this gene is now being investigated. Data generated from this study may yield a new therapeutic target that could have a broad application to the diagnosis and treatment of breast cancer. Support: NCI R01 CA123246 (PHB), NIH/NCI T32 CA909221 (JAM)

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1131.

Identification of Critical Transducers of Rexiniod-Mediated Growth Suppression in Normal Breast Cells

Background: Targeted agents against the estrogen receptor are effective in treating and preventing many breast cancers, but these agents are not effective for the treatment or prevention of estrogen receptor-negative (ER-neg) breast cancer. Our laboratory has demonstrated that rexinoids are capable of preventing ER-neg breast cancer in transgenic mice; however, this treatment is not 100% effective. Therefore, it is imperative to delineate the mechanism by which rexiniods prevent breast cancer to develop more effective prevention strategies. We hypothesized that rexinoids are specifically able to prevent breast cancer by suppressing growth though interactions with key nuclear hormone receptors. To test this hypothesis we conducted high-throughput screens to determine which nuclear hormone receptors are critical to transduce the growth suppressive effects of rexinoids.Methods: We used quantitative RT-PCR to determine the quantity of mRNA transcripts for all 48 nuclear hormone receptors in human mammary epithelial cells (HMECs). To identify nuclear hormone receptors that when knocked-down reverse the effects of rexiniod treatment, a final concentration of 30nM of pools of three independent siRNAs specific to each nuclear hormone receptor was used. High-throughput microscopy of the siRNA-treated HMECs stained with DAPI (1μg/mL) and EdU (10mM) was used to analyze growth. If a receptor's corresponding siRNA reversed the growth inhibitory effects of rexinoids 75% or greater, it was considered for further investigation. Receptors that did not reverse the effect of rexiniods or enhanced growth suppression when knocked-down were identified, but were not studied further in this analysis. Co-immunoprecipitation (coIP) and GST pull-down assays are being conducted to investigate whether the identified nuclear hormone receptors form a complex with, or bind to, RXR proteins.Results: qRT-PCR analysis confirmed that many of known RXR-binding nuclear hormone receptors are expressed in HMECs. High-throughput screens indicate that knockdown of most receptors alone (including COUP TF1, EAR1 and ERRβ) affect growth of HMECs but do not reverse the effects of rexinoid treatment. Loss of ERRα and AR induced growth, but rexiniod treatment suppressed growth to a greater extent than controls. Receptors that appeared to reverse the growth suppressive effect of rexiniods include GCNF1, THRα, PNR and PPARγ. Loss of PPARγ alone stimulated growth, but reversed effects of rexiniod-induced growth suppression. Currently, we are further investigating these receptors in HMECs and other cell types.Conclusions: These experiments have identified nuclear hormone receptors that are critical for the growth suppressive effects of rexiniods in normal human breast cells. Identification of such receptors provides possible targets for preventative therapy used alone, or in combination with rexinoids, to increase the efficacy of rexinoids for more effective prevention of estrogen receptor-negative breast cancer. Support: NCI R01 CA78480 (PHB, IPU) and NIH/NCI T32 CA90221 (JMR)

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3134.

Collaborative annotation of genes and proteins between UniProtKB/Swiss-Prot and dictyBase

UniProtKB/Swiss-Prot, a curated protein database, and dictyBase, the Model Organism Database for Dictyostelium discoideum, have established a collaboration to improve data sharing. One of the major steps in this effort was the ‘Dicty annotation marathon’, a week-long exercise with 30 annotators aimed at achieving a major increase in the number of D. discoideum proteins represented in UniProtKB/Swiss-Prot. The marathon led to the annotation of over 1000 D. discoideum proteins in UniProtKB/Swiss-Prot. Concomitantly, there were a large number of updates in dictyBase concerning gene symbols, protein names and gene models. This exercise demonstrates how UniProtKB/Swiss-Prot can work in very close cooperation with model organism databases and how the annotation of proteins can be accelerated through those collaborations.

NCCTG phase I trial of temsirolimus (CCI-779) and temozolomide (TMZ) in combination with radiation therapy (RT) in newly diagnosed glioblastoma multiforme (GBM) patients

2019

Background: The mammalian target of rapamycin (mTOR) functions within the PI3K/Akt signaling pathway as a critical modulator of cell survival. We previously demonstrated significant synergy of the mTOR inhibitor sirolimus with RT in glioma xenografts. Methods: The standard cohorts of 3 design was applied with dose escalation of weekly IV CCI-779 in combination with standard TMZ/RT. CCI-779 was given during both RT (60 Gy)/TMZ (75 mg/m2 daily) and adjuvant TMZ (200 mg/m2 daily x 5 every 28 days). Results: A total of 17 patients were enrolled. CCI-779 therapy during RT/TMZ was well tolerated at dose level 0 (25 mg CCI-779, n = 3) and dose level 1 (50 mg CCI-779, n = 6) with 1 of 9 patients experiencing a DLT (Gr 3 fatigue). Dose level 2 (75 mg CCI-779) exceeded the maximally tolerated dose with two of six patients with DLT (<75% CCI-779 delivered; Gr 4 dyspnea). Despite reasonable tolerance during RT/TMZ, the overall regimen was associated with a high rate of infection associated with lymphopenia. After a patient died from PCP on cycle 2 of adjuvant TMZ/CCI-779, antibiotic prophylaxis was mandated. Two other patients died of gram-negative sepsis despite prophylaxis: one after their first dose of CCI-779 and one during cycle 4 of adjuvant therapy. In contrast to our 18% grade 5 infection rate, only 4% grade 3 (no grade 4/5) infections were observed in 26 other CTEP-sponsored clinical trials involving 1,006 patients treated with CCI-779. Results from translational studies evaluating the effects of treatment on immune function will be presented. Further infections were avoided on this trial after CCI-779 therapy was limited to RT/TMZ. Conclusions: Although CCI-779 in combination with RT/TMZ was well-tolerated, adjuvant therapy with TMZ/CCI-779 was associated with an increased risk of opportunistic infections.

[Table: see text]

LX1032: A potential new therapy for carcinoid syndrome (CS)

e14555

Background: Patients with metastatic CS experience a variety of symptoms due to increased serotonin (5-HT) produced by metastatic GI tumor cells. The enzyme tryptophan hydroxylase (TPH) catalyzes the rate-limiting step in the synthesis of 5-HT. Reducing 5-HT synthesis by TPH inhibition represents a new mechanism for potentially managing symptoms associated with CS. LX1032 is a novel, orally bioavailable TPH inhibitor designed to afford systemic exposure without affecting 5-HT synthesis in the CNS. Preclinical studies of LX1032 in multiple species confirmed systemic inhibition of 5-HT synthesis without changes in brain 5-HT levels. Methods: Single (n=47 subjects) and multiple (n=40 subjects) ascending dose studies with LX1032 were completed in normal volunteers; 24-hr urinary 5-HIAA and blood 5-HT were measured as biomarkers of 5-HT metabolism. Results: LX1032 produced a significant dose-dependent reduction in urinary 5-HIAA and blood 5-HT levels, with maximal reductions observed at doses at or above 500 mg, once daily, in the 14 day multiple ascending dose (MAD) study; the mean change from baseline in blood 5-HT was -30% for the 1500 mg (500 mg TID) dose group. Single doses up to 500 mg were well tolerated with no evidence of dose limiting toxicity or tolerability; GI related adverse events (nausea, emesis, and diarrhea) started to emerge at the 1,000 mg dose level and became dose-limiting at the 1,500 mg single dose level. Multiple doses were well tolerated at all dose levels up to 1.500 mg (500 mg TID). Adverse events (AEs) were mild to moderate and no serious AEs occurred; a dose-dependent, mild increase in hepatic transaminase levels was observed in the MAD study. Conclusions: Inhibiting TPH, and thereby reducing peripheral 5-HT production, represents a potential new approach for managing symptoms in CS patients. LX1032 is a novel, orally bioavailable TPH inhibitor that significantly reduced 5-HT production at well tolerated dose levels. The favorable safety profile and observed decrease in urinary 5-HIAA and blood 5-HT levels indicate that LX1032 could be used to lower 5-HT as a potential new approach for managing hyperserotoninemia-related complications of CS, and support studies of the compound in CS patients.

[Table: see text]

The analyses of antigen and DNA polymorphism within the bovine major histocompatibility complex: 1. The class I antigens

Serology, isoelectric focusing (IEF) of expressed antigens, and restriction fragment length polymorphisms (RFLP) were compared for the identification of BoLA class I haplotypes. Expressed antigens identified as bands by IEF correlated well with serological definition confirming and extending our earlier findings (Joosten et al. 1988). Comparison of serology and isoelectric focusing bands with restriction fragments was more complicated; fragments were found which correlated both with broadly reacting and antigen specific sera. We also found correlation of fragments with two or more sera which showed no cross-reactivity. Fragments unique to particular haplotypes were also observed. Serology remains the simplest method of typing BoLA class I antigens. Isoelectric focusing generally agrees with serological definition of antigens and detects antigens not yet defined by serology. It may also be useful in defining the products of other expressed BoLA class I loci. In order to identify RFLPs which could be used for typing, comparison with serology or IEF is essential. Haplotype specific RFLPs could be useful in identifying genes linked to the MHC.