Receptor-mediated inhibition of small bowel migrating complex by GLP-1 analog ROSE-010 delivered via pulmonary and systemic routes in the conscious rat

BACKGROUND

ROSE-010, a Glucagon-Like Peptide-1 (GLP-1) analog, reduces gastrointestinal motility and relieves acute pain in patients with irritable bowel syndrome (IBS). The rat small bowel migrating myoelectric complex (MMC) is a reliable model of pharmacological effects on gastrointestinal motility. Accordingly, we investigated whether ROSE-010 works through GLP-1 receptors in gut musculature and its effectiveness when administered by pulmonary inhalation.

MATERIALS AND METHODS

Rats were implanted with bipolar electrodes at 5, 15 and 25 cm distal to pylorus and myoelectric activity was recorded. First, intravenous or subcutaneous injections of ROSE-010 or GLP-1 (1, 10, 100 μg/kg) with or without the GLP-1 receptor blocker exendin(9-39)amide (300 μg/kg·h), were studied. Second, ROSE-010 (100, 200 μg/kg) Technosphere® powder was studied by inhalation.

RESULTS

The baseline MMC cycle length was 17.5±0.8 min. GLP-1 and ROSE-010, administered intravenously or subcutaneously, significantly inhibited myoelectric activity and prolonged MMC cycling; 100 μg/kg completely inhibited spiking activity for 49.1±4.2 and 73.3±7.7 min, while the MMC cycle length increased to 131.1±11.4 and 149.3±15.5 min, respectively. Effects of both drugs were inhibited by exendin(9-39)amide. Insufflation of ROSE-010 (100, 200 μg/kg) powder formulation totally inhibited myoelectric spiking for 52.6±5.8 and 70.1±5.4 min, and increased MMC cycle length to 102.6±18.3 and 105.9±9.5 min, respectively.

CONCLUSIONS

Pulmonary delivery of ROSE-010 inhibits gut motility through the GLP-1R similar to natural GLP-1. ROSE-010 causes receptor-mediated inhibition of MMC comparable to that of intravenous or subcutaneous administration. This suggests that ROSE-010 administered as a Technosphere® inhalation powder has potential in IBS pain management and treatment.

Highly sensitive nonradioactive single-strand conformational polymorphism. Detection of Ki-ras mutations

Mutation detection by single-strand conformational polymorphism (SSCP) analysis is more difficult when the variant is limited to a small proportion of target sequences in a sample. Use of SYBR-Green II, a sensitive, nonradioactive, minimally hazardous nucleic acid stain, permits detection of Ki-ras mutants present as less than 0.5% of the target sequences. The polymerase chain reaction (PCR) primers we have selected produce an amplicon that distinguishes all clinically observed variants in Ki-ras codons 12 and 13 from the wild type. We compared mutant discrimination and SYBR-Green II detection sensitivity in three formats: (a) standard MDE gel SSCP, (b) rapid minigel MDE using an internal gel temperature controller, and (c) rapid resolution in chilled 15% (37.5:1) acrylamide minigels. All these gels are easily evaluated by standard ultraviolet transillumination and digital image analysis. This ssDNA staining method is rapid, highly reproducible, and minimally hazardous, and minigels use 25% the reagents of most other systems. Our improvements are relevant for the detection of mutations in pathologic samples with minimal targets, such as fine-needle aspirates, and body fluids in which mutated alleles of a gene may be present at low levels but carry a high level of diagnostic or prognostic importance.

Combined modality (ABVD plus radiotherapy) versus radiotherapy in the management of early stage (IIA) Hodgkin's disease with mediastinal involvement

The aim of this study was to establish whether combined modality treatment (ABVD plus radiotherapy) can reduce the risk of relapse in Hodgkin's disease patients with mediastinal involvement, as compared to radiotherapy alone. The results obtained suggest that one course of ABVD before irradiation can reduce the incidence of relapse. These findings, however, should be considered preliminary and need to be confirmed in larger studies.

Hemolytic anemia and thrombocytopenia induced by cyanidanol

Five patients who received cyanidanol for 4-36 months are presented. Three developed both hemolytic anemia and thrombocytopenia, while 2 had only thrombocytopenia. After suspending the drug the hematological values returned to normal in all of the patients. Drug-dependent platelet antibodies were detected in 4 of the 5 patients and cyanidanol-dependent red blood cell antibodies were present in 3. There are various mechanisms involved in the cyanidanol-induced immune cytopenias and, as in the present study, were sometimes simultaneously observed in the same patient.

A second example of hemolysis due to IgA autoantibody with anti-e specificity

A case of warm autoimmune hemolytic anemia due to IgA antibody is described. The patient had clinical and hematologic signs of hyperhemolysis, but all specific tests were negative. The direct antiglobulin test was positive only when it was performed with anti-IgA monospecific antiserum. The autoantibody eluted from the patient's red cells showed anti-e specificity. The sensitivity of broad-spectrum antiglobulin serum and the possible hemolytic mechanisms of IgA-coated red cells are discussed.