Flow cytometric determination of basophils in whole blood with n-propyl Astra Blue iodide

Within the past year, it has become apparent, in connection with its use on automatic flow cytometers, that the quality of commercially available Alcian Blue has significantly declined. A homologous series of alkylated (C1-C7) Astra Blue quaternary ammonium halides was prepared, characterized, and evaluated for the detection of basophils in whole blood. On the Technicon H6000 flow cytometer, the resolution of the basophil cluster from the main population of unstained white blood cells was found to depend on the chain length of the quaternizing alkyl group. Optimal basophil resolution was observed for the n-propyl derivative. Correlation of the new method vs Alcian Blue as the reference on the H6000 was expressed as follows: %Baso (Astra Blue) = 0.89% Baso (Alcian Blue) + 0.12% for 180 fresh whole blood samples. Within-run precision at a basophil differential count of 0.73% was characterized by SD = 0.11, identical to that obtained for Alcian Blue. Aqueous solutions of n-propyl Astra Blue iodide, in contrast to Alcian Blue, are thermally stable. Heating the reagent for 1 h at 100 degrees C did not alter solubility or cytochemical behavior. In contrast, parallel treatment of Alcian Blue yielded insoluble material by hydrolysis of the isothiouronium groups. The reagent for basophil detection comprises n-propyl Astra Blue iodide, lanthanum chloride, sodium chloride, Tween 20, and cetylpyridinium chloride. The Astra Blue derivatives were characterized by uv-vis, ir, percentage halide, paper chromatography, and 13C NMR.     

Fine Mapping the Spatial Distribution and Concentration of Unlabeled Drugs within Tissue Micro-Compartments Using Imaging Mass Spectrometry

Readouts that define the physiological distributions of drugs in tissues are an unmet challenge and at best imprecise, but are needed in order to understand both the pharmacokinetic and pharmacodynamic properties associated with efficacy. Here we demonstrate that it is feasible to follow the in vivo transport of unlabeled drugs within specific organ and tissue compartments on a platform that applies MALDI imaging mass spectrometry to tissue sections characterized with high definition histology. We have tracked and quantified the distribution of an inhaled reference compound, tiotropium, within the lungs of dosed rats, using systematic point by point MS and MS/MS sampling at 200 µm intervals. By comparing drug ion distribution patterns in adjacent tissue sections, we observed that within 15 min following exposure, tiotropium parent MS ions (mass-to-charge; m/z 392.1) and fragmented daughter MS/MS ions (m/z 170.1 and 152.1) were dispersed in a concentration gradient (80 fmol-5 pmol) away from the central airways into the lung parenchyma and pleura. These drug levels agreed well with amounts detected in lung compartments by chemical extraction. Moreover, the simultaneous global definition of molecular ion signatures localized within 2-D tissue space provides accurate assignment of ion identities within histological landmarks, providing context to dynamic biological processes occurring at sites of drug presence. Our results highlight an important emerging technology allowing specific high resolution identification of unlabeled drugs at sites of in vivo uptake and retention.     

Identification and design of a novel series of MGAT2 inhibitors

[Acyl CoA]monoacylglycerol acyltransferase 2 (MGAT2) is of interest as a target for therapeutic treatment of diabetes, obesity and other diseases which together constitute the metabolic syndrome. In this Letter we report our discovery and optimisation of a novel series of MGAT2 inhibitors. The development of the SAR of the series and a detailed discussion around some key parameters monitored and addressed during the lead generation phase will be given. The in vivo results from an oral lipid tolerance test (OLTT) using the MGAT2 inhibitor (S)-10, shows a significant reduction (68% inhibition relative to na?ve, p <0.01) in plasma triacylglycerol (TAG) concentration.     

Release of PYY from pig intestinal mucosa; luminal and neural regulation

The localization, molecular nature and secretion of Peptide YY (PYY), a putative gut hormone belonging to the Pancreatic Polypeptide family of peptides, was studied in pigs. Immunoreactive PYY was identified in a population of endocrine cells in the mucosal epithelium of the pig ileum. Release of PYY was observed in isolated perfused pig ileum in response to luminal stimulation with glucose and vascular administration of the neuropeptide gastrin-releasing peptide (GRP). Electrical stimulation of the vagus nerve supply to the distal small intestine in intact anaesthetized pigs resulted in release of PYY into the circulation. Stimulation of the splanchnic nerves did not affect the basal release of PYY. PYY-immunoreactivity extracted from ileal tissue or released to plasma or perfusate from the ileum was indistinguishable from synthetic porcine PYY by gel filtration and reverse phase HPLC. It is concluded that the secretion of PYY in the pig ileum may be regulated not only by nutritional luminal factors, but also by postsynaptic parasympathetic nerves.     

Distribution and molecular forms of peptides containing somatostatin immunodeterminants in extracts from the entire gastrointestinal tract of man and pig

Specimens from human porcine mucosal and muscular tissue from the entire gastrointestinal tract were extracted in acid ethanol, subjected to chromatography and analysed for somatostatin-like immunoreactivity by region-specific radioimmunoassays. The concentration of somatostatin-like immunoreactivity from man and pig ranged from 1.13 +/- 0.37 to 101.15 +/- 33.93 pmol/g wet weight, and from 7.64 to 159.48 +/- 23.79 pmol/g wet weight, respectively. In both species the highest concentrations were found in the jejunum. The immunoreactivity in intestinal mucosal extracts was distributed among four major peaks, two of which were identified by HPLC as somatostatin 1-28 and somatostatin 1-14, respectively. A peak of approx. 10 kDa was resolved by ion exchange plus HPLC into three components, two containing at least part of the somatostatin 1-14 sequence as well as (part of) the somatostatin 1-28(1-14) sequence (but differing in charge), the third containing only the 1-28(1-14) sequence. These peptides probably represent uncleaved and partially cleaved prosomatostatin. The fourth component to be identified by gel filtration was slightly larger than somatostatin 1-14. Extracts from the antrum, the pancreas and from muscular tissues contained almost exclusively somatostatin 1-14, and very little somatostatin 1-28, indicating that the somatostatin precursor is processed differently at these sites. Furthermore, extracts of porcine gastric antrum, analysed for somatostatin 1-28(1-14) immunoreactivity, showed two immunoreactive forms in the mucosa and three major forms in the muscular layers.     

Quantification of arabinogalactan-protein in plant extracts by single radial gel diffusion

The amount of arabinogalactan-protein in whole plant extracts can be quantified by single radial diffusion in agarose gels containing a dye known as the beta-glucosyl-Yariv reagent which specifically interacts with and precipitates arabinogalactan-proteins. The lower limit of quantification is 0.04 microgram of arabinogalactan-protein; gum arabic is used as a standard reference arabinogalactan-protein. In principle, this method can be adapted to measure levels of any dye-precipitating macromolecule; for example, acidic polysaccharides can be estimated by their binding to the cationic dye Alcian blue.     

A developmentally regulated hydroxyproline-rich glycoprotein from the cell walls of soybean seed coats

In soybean seeds the level of hydroxyproline is regulated in a developmental and tissue-specific manner. The seed coat contains approximately 77% of the total hydroxyproline in the seed at all stages of development. We determined the ratio of hydroxyproline to dry weight in a number of tissues within the seed; however, only the seed coat shows an increase in this ratio during development. Within the many cell layers of the seed coat, hydroxyproline is most abundant in the external layer. The hydroxyproline is present as an hydroxyproline-rich cell wall glycoprotein. The protein is rich in hydroxyproline (36%), lysine (11%), proline (10%), histidine (9%), tyrosine (9%), and serine (8%). The carbohydrate portion is 90 mole% arabinose and 10 mole% galactose. The arabinose residues are attached to hydroxyproline mostly in the form of trisaccharides. The apparent molecular weight of this glycoprotein is 100,000 daltons.     

Asthma mortality: comparison between New Zealand and England.

Causes for the high mortality from asthma in New Zealand were investigated by comparing deaths from asthma in caucasian subjects aged 15-64 in New Zealand with those from asthma in the same age group in two regions in England. There were no significant differences in the accuracy of death certification. The verified asthma mortality in New Zealand (4.2/100,000) was over twice that in England. Many characteristics of patients and management, including poor compliance with treatment and deficiencies in long term and emergency care, were qualitatively similar in the two countries. New Zealand had an apparently higher rate of non-preventable deaths from asthma, suggesting a greater severity of asthma in New Zealand. In both countries, however, most deaths were associated with poor assessment, underestimation of severity and inappropriate treatment (over-reliance on bronchodilators and underuse of systemic corticosteroids), and delays in obtaining help. A greater frequency of some of these deficiencies in management remains a possible additional explanation for part of the excess mortality in New Zealand.