A direct plasma testosterone radioimmunoassay

Résumé On a développé und méthode simple pour déteminer sans chromatographie en colonne le testostérone du plasma. La purification a été faite par préextraction avec l'hexane. Un antisérum contre le testostérone a été produit chez des lapins inoculés avec des conjugués de testostérone-3-oxine et d'albumine de sérum bovin.     

Vitamin A antibodies: Application to radioimmunoassay

Summary A radioimmunoassay for serum vitamin A is described which can detect as little as 1 ng of retinol. The statistical characteristics of this assay are presented and its use in a nutritional experiment is discussed.This work was supported by United States Public Health Service grant 2 RO1 AM19716.     

A technical improvement in the radioimmunoassay of cyclic-AMP.

An improvement in the technique for the radioimmunoassay of cyclic-AMP, wherein ammonium sulfate precipitation is replaced with zirconyl phosphate gel, is presented. This substitution produces a more stable pellet than that obtained with ammonium sulfate. This greatly reduces a potential source of error due to pellet instability.     

A radioimmunoassay of vasopressin. A note on pituitary vasopressin content in brattleboro rats

Zusammenfassung Die Empfindlichkeit und Zuverlässigkeit eines neu entwickelten Radioimmunotests für Vasopressin wurde durch Messungen des Vasopressinspiegels im Hypophysenhinterlappen von homozygoten und heterozygoten Ratten für angeborenen Diabetes insipidus geprüft und eine gute Korrelation zwischen dem biologisch und radioimmunologisch gemessenen Vasopressingehalt der Hypophyse nachgewiesen.     

Phenobarbital specific antisera and radioimmunoassay

Résumé On a développé un anticorps d'une grande affinité et spécifité envers le phénobarbital en inoculant des lapins avec une solution de barbiturateprotéide, synthétisée d'acide barbiturique de 5-phényl-5-(4-aminobutyl) et d'albumine de sérum bovin par du carbodiimide. Usant de cet anticorps comme radioimmunoeassai, on peut mesurer jusqu'à 1 picomole de phénobarbital par ml de fluides biologique sans que d'autres barbiturates y opposent une réaction significative.

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We express our appreciation to the Lilly Research Laboratories for the donation of amobarbital and secobarbital.     

A radioimmunoassay for deoxycorticosterone in human peripheral plasma using sephadex LH-20 chromatography

Resumen Se reporta un nuevo método para medir desoxicorticosterona en plasma, usando cromatografía de columna LH-20 y radioinmunoensayo. Las cantidades de plasma necesarios para dicho ensayo son mínimas (2 ml) comparadas con otros métodos en la literatura, es un método practico, sensillo y rápido. Resultados así obtenidos han sido comparados con otros métodos, dichos resultados son más precisos y sensitivos para medir valores de desoxicorticosterona en plasma humano.     

Simplification of the ecdysteroid radioimmunoassay by the use of protein A fromStaphylococcus aureus

Summary Three methods of separating antibody-bound ligand from free ligand were compared for an ecdysteroid radioimmunoassay. Ecdysteroid antibody concentration and ligand specific radioactivity were adjusted to measure 2 ranges of ecdysone concentrations (0.01–2.0 ng and 0.25–32.0 ng). In comparison with the tradiotional separating agent, ammonium sulfate, neither protein A nor polyethylene glycol altered sensitivity or specificity of the radioimmunoassays. The protein A immunoglobulin precipitation method is quick and simple, making it a preferred alternative protocol for terminating ecdysteroid radioimmunoassays.Supported by grants AM-30118 from the National Institutes of Health and PCM-8116931 from the National Science Foundation.     

Presence of digoxin detectable by radioimmunoassay inTetrahymena

Summary Digoxin was demonstrated inTetrahymena pyriformis by radioimmunoassay, at a concentration of 4.3 ng/100,000 cells. Pretreatment of the cells with digoxin or ouabain did not significantly alter the digoxin concentration of the progeny generations.     

Stereoselectivity of a radioimmunoassay for the insecticide S-bioallethrin

Summary The stereoselectivity of a radioimmunoassay (RIA) system using an S-bioallethrin specific antiserum was studied by observing the abilities of the 8 allethrin isomers and other selected compounds to compete with a radiolabelled S-bioallethrin tyramine derivative for antibody binding sites. The results demonstrate the feasibility of RIA as a rapid, sensitive and stereoselective residue technique for compounds difficult to analyze by classical methods.This work was supported in part by grant No. 5-R01-ES01260-02 from the National Institutes of Health.     

Stereoselectivity of a radioimmunoassay for the insecticide S-bioallethrin

The stereoselectivity of a radioimmunoassay (RIA) system using an S-bioallethrin specific antiserum was studied by observing the abilities of the 8 allethrin isomers and other selected compounds to compete with a radiolabelled S-bioallethrin tyramine derivative for antibody binding sites. The results demonstrate the feasibility of RIA as a rapid, sensitive and steroselective residue technique for compounds difficult to analyze by classical methods.     

9,10-Dihydroergotamine: Production of antibodies and radioimmunoassay

Summary Antibodies against 9,10-dihydroergotamine (DHE) were produced by immunizing rabbits with a conjugate of 6-nor-6-carboxymethyl-9,10-dihydroergotamine and bovine serum albumin. A highly specific and sensitive radioimmunoassay for DHE has been developed.We are greatly indebted to Dr.T. Fehr for the synthesis of 6-nor-6-carboxymethyl-9,10-dihydroergotamine, and to Dr.E. Schreier for providing us with 9,10-dihydroergotamine-[13-³H]-base of high specific activity.     

A spectrophotometric method for the direct recording of dioldehydrase activity

Zusammenfassung Es wird eine raschere und empfindlichere Methode zur Bestimmung der Aktivität von Dioldehydrase beschrieben.     

A new direct method for the assay of human renin

Résumé Nous avons instituté une nouvelle méthode directe pour l'estimation du rénin par l'immunoélectrophorèse. Les résultats préliminaires obtenus par cette méthode indiquent que des changements importants peuvent se faire dans l'activité enzymatique du rénin dans le cas de patients ayant de l'hypertension rénale.

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We are indebted to Dr.C. Robinson of the Division of Biological Standards Medical Research Council, Mill Hill, for samples of purified human renin, and to Prof.J. R. Hobbs of the Department of Chemical Pathology, Westminster Hospital Medical School, for his support of this work.     

Bioavailability of progesterone enhanced by intranasal spraying

Summary The bioavailability of progesterone (P) in terms of area under time-concentration curve and maximal concentration in the serum and cerebrospinal fluid was studied in adult ovariectomized rhesus monkeys following the administration of P as a nasal spray, i.v. or i.m. injections, nasal or eye drops. The bioavailability of P in both the body fluids was found to be considerably higher following its being sprayed intranasally.This work was supported by the World Health Organization, Geneva.     

A densitometric adapter for direct plotting of electrophoretic curve from paper strips

Zusammenfassung Der Verfasser beschreibt eine Apparatur zur objektiven Auswertung der Papierelektrophoretogramme. Er benützt ein Coleman-Spektrophotometer und einen besonders entwickelten Adapter.