Aminoacid constitution of two gastrins isolated from Zollinger-Ellison tumour tissue

Two peptides which are potent stimulants of gastric acid secretion are isolated from Zollinger-Ellison tumour tissue. They have aminoacid constitutions identical with those of human gastrin types I and II as isolated from human antral mucosa, and they are present in similar proportions. Their electrophoretic and chromatographic behaviour corresponds to that of human gastrins. Evidence is presented in respect of the one isolated in greater amount that its aminoacid sequence is probably identical with that of human gastrin type I.     

Stereospecific monoclonal antibodies to nicotine and cotinine and their use in enzyme-linked immunosorbent assays

Stereospecific monoclonal antibodies (McAb) have been prepared against the tobacco alkaloid (S)-(-)-nicotine and its major metabolite (S)-(-)-cotinine. Nine anti-nicotine and 4 anti-cotinine hybridomas, selected by a screening procedure that utilized immunoprecipitation of the ³H-labeled natural isomers of nicotine or cotinine, were grown in the ascites fluid of pristane-primed syngeneic BALB/c mice. Antibodies in concentrations up to 7.5 mg/ml ascites and with binding affinities that generally exceeded 10⁸ M⁻¹ were obtained. Enzyme-linked immunosorbent assays (ELISAs) were developed in which nicotine or cotinine derivatives bound covalently to poly- -lysine werecoated onto wells of polyvinyl chloride microtiter plates. Coated wells were incubated sequentially with McAb in the presence or absence of inhibitor, rabbit anti-mouse immunoglobulin, then horseradish peroxidase-labeled protein A (HRP-SpA) before addition of substrate. The antibodies are highly specific and show minimal cross-reactivity with several nicotine metabolites and other structurally related compounds. In the respective assays, only 0.25 ng (S)-(-)-nicotine and 0.12 ng (S)-(-)-cotinine are required to give 50% inhibition of antibody binding, and as little as 0.05 ng nicotine and 0.02 ng cotinine give 15% inhibition. These assays are 5–10 times more sensitive than analogous ELISAs developed with rabbit antisera and HRP-SpA or conventional radioimmunoassays (RIAs) that utilize the rabbit antisera and ³H-labeled ligands. There was good correlation between the levels of nicotine (r = 0.967) found in saliva samples from smokers and non-smokers assayed by McAb-based ELISAs and conventional RIAs.     

Health-related quality of life in glomerular disease

1. Download high-res image (449KB)
2. Download full-size image

     

Cytodiagnosis of actinomycetoma

Mycetoma is a late clinical manifestation of a subcutaneous infection produced by bacteria (actinomycetoma) or fungi (eumycetoma). The distinction between eumycetoma and actinomycetoma in Fine Needle Aspiration Cytology (FNAC) is as accurate as histopathology. A 55 year old man presented with a slow growing swelling on the plantar aspect of the right foot which was present for the last 10 years. A clinical diagnosis of soft tissue tumor was made and FNAC was advised. Smears revealed mixed inflammatory infiltrate and foreign body type of giant cells along with clumps of fibrillar organisms. Gram stain done later demonstrated gram positive thin branching filaments. A diagnosis of actinomycetoma was rendered. Histopathology of the excised specimen confirmed the cytologic diagnosis of actinomycetoma. Mycetoma can be accurately diagnosed by FNAC, which is a simple, inexpensive technique for rapid diagnosis. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.     

Differential secretion of chicken growth hormone variants after growth hormone-releasing hormone stimulation in vitro

Variants of growth hormone (GH) are present in most vertebrates. Chicken GH (cGH) undergoes posttranslational modifications that contribute to its structural diversity. Although the 22-kDa form of GH is the most abundant, some other variants have discrete bioactivities that may not be shared by others. The proportion of cGH variants changes during ontogeny, suggesting that they are regulated differentially. The effect of growth hormone-releasing hormone (GHRH) on the release of cGH variants was studied in both pituitary gland and primary cell cultures, employing sodium dodecyl sulfate polyacrylamide gel electrophoresis, Western blotting, and densitometry. GHRH (2 nM, 2 h) stimulated the secretion of most of the size variants of cGH although the amplitude of increase was not equal for each one. A differential effect on the secretion of GH size variants, particularly on the 22- (monomer) and 26-kDa (putatively glycosylated) cGH isoforms was found in both systems. In the whole pituitary culture, the proportion of the 26-kDa immunoreactive cGH increased 35% while the 22 kDa decreased 31% after GHRH treatment in comparison with the controls. In the primary cell culture system, the proportion of the glycosylated variant increased 43% whereas the monomer and the dimer decreased 22.26 and 29%, respectively, after GHRH stimulation. Activators of intracellular signals such as 1 mM 8-bromo-cAMP and 1 μM phorbol myristate acetate had a similar effect to that obtained with GHRH. The data support the hypothesis that GH variants may be under differential control and that GHRH promotes the release of a glycosylated cGH variant that has an extended half-life in circulation.     

Media Exchange Method for Demonstrating Killing of L-Phase Variants in Solid Media by Normal Human Serum

Normal human serum has been shown to kill L-phase variants in a fluid system by the action of antibody plus complement. Previous studies, however, failed to demonstrate such killing in solid media. This failure probably resulted from inhibition of complement by medium components such as agar and NaCl. A method was developed which circumvents the problems of the anticomplementary properties of agar media and the requirement of some L-phase variants for concentrations of salt that inhibit complement. Using this method, we have demonstrated in solid media the killing by normal human serum of the L-phase variants of Staphylococcus aureus, Proteus mirabilis, Streptococcus pyogenes, S. faecalis, Pseudomonas aeruginosa, and Salmonella typhi. This method provides a relatively simple and graphic means for studying host humoral factors lethal for L-phase variants.     

Effect of 4-aminopyridine on cardiovascular functions in the dog

The drug 4-aminopyridine (4-AP) at a dose of 0.2 mg kg^-1 body weight intravenously is an effective antagonist of non-depolarizing neuromuscular blockade. We studied its cardiovascular effects in the canine heart using a right-heart bypass with extracorporeal circulation in seven dogs. This study demonstrates that 4-aminopyridine significantly augments arterial blood pressure, left ventricular dp/dt maximum, as well as left ventricular pressure at dp/dt mx. The highest values were obtained between two and 20 minutes after administration of 4-AP. Left ventricular end-diastolic pressure diminished slightly, but this was not statistically significant. Although the exact mechanism of action of 4-AP is not known, its positive inotropic effects may be of value in the reversal of non-depolarizing neuromuscular blockade in patients with impaired myocardial function of diverse aetiologies and it would be contraindicated in patients with arterial hypertension and/or coronary artery disease.     

The range and specificity of antinuclear antibodies in systematic lupus erythematosus

Antibodies to nine calf thymus nuclear antigens were sought by complement fixation methods in twenty-four sera from sixteen patients with systemic lupus erythematosus. These antigens included whole nuclei, native and heat denatured DNA, particulate and soluble nucleoprotein and Sm antigen. Soluble antigens were also tested by tanned red-cell agglutination tests. A wide variation in the presence and titres of antibodies to these various antigens was found in the sera studied even when from the same patient but at different times. To further test the range and specificity of antinuclear antibodies in SLE, nineteen ribonucleosides, nucleotides and monophosphoric dinucleotides were coupled to human serum albumin and used as antigens in precipitin studies. A wide variation of reactivity was also found in each serum. Exquisite specificity became apparent, capable of reacting with a nucleoside but not with the corresponding nucleotide or vice versa, with a dinucleotide but not with the nucleotides or nucleosides which it contained, with a given dinucleotide but not with the opposite sequence.

Antinuclear antibodies in systemic lupus are, therefore, markedly heterogeneous. Those to a `single' antigen such as DNA may be directed to antigenic sites which may variously be at the bases, single or in sequence, at the site of union of base and sugar–phosphate moiety, at the backbone of deoxyribophosphate or actually dependent on the secondary structure.

     

Aortic homograft for pulmonary artery augmentation in single lung transplantation

We present a case of unilateral lung transplantation in which a segment of the donor's descending aorta was used as a homograft for pulmonary artery augmentation in the donor lung. This technique can be used when the donor's lung artery has been cut at the base of the hilum during the harvesting procedure.