Sex estimation using diagonal diameter measurements of molar teeth in African American populations.

Teeth are often recovered in forensic cases due to their postmortem longevity. The goal of the present research was to investigate the degree of sexual dimorphism in the permanent molars of African Americans using crown and cervical diagonal diameters. Discriminant functions developed from a modern Greek population were tested for accuracy of sex estimation in an African American population.

The International Standard for Netilmicin.

An International Standard for Netilmicin has been established on the basis of a collaborative assay. There were five participating laboratories in five countries. The activity of the contents of each ampoule of the International Standard for Netilmicin is defined as 4810 IU of netilmicin.

The International Standard for Endotoxin: evaluation in an international collaborative study.

An ampouled preparation of bacterial endotoxin, coded 84/650, was evaluated in 35 laboratories in 12 countries for its suitability to serve as the International Standard for Endotoxin. The ampouled preparation was calibrated in terms of the USA National Standard, EC5, in Limulus Amoebocyte Lysate gelation, turbidimetric and chromogenic tests and in rabbit pyrogen tests. On the basis of the results reported here, with the agreement of the participants in the study, and with the authorization of the Expert Committee on Biological Standardization of the World Health Organization, the preparation coded 84/650 was established in 1986 as the International Standard for Endotoxin for Limulus Gelation Tests with an assigned unitage of 14,000 IU of endotoxin per ampoule.

The International Standard for sisomicin.

An International Standard for Sisomicin has been established on the basis of a collaborative assay. There were seven participating laboratories in seven countries. The activity of the contents of each ampoule of the International Standard of Sisomicin is defined as 35,200 International Units of Sisomicin.

The International Standard for Kanamycin.

The International Reference Preparation of Kanamycin has been replaced by the International Standard for Kanamycin. The potency of the standard is based upon a collaborative study in ten laboratories in ten countries. Each ampoule of the International Standard of Kanamycin is defined as containing the activity of 10345 International Units of Kanamycin.

British standard for human serum vitamin B12.

Seven laboratories took part in a collaborative study of an ampouled preparation of normal serum labelled 81/563. Each laboratory calibrated the preparation in terms of pure cyanocobalamin by use of Euglena assay. The inclusion of pernicious anaemia serum in the study and additional tests for safety and stability indicated that 81/563 would be a suitable standard for diagnostic testing.

The International Standard for Amikacin.

An International Standard for Amikacin has been established on the basis of a collaborative assay. Seven laboratories, in seven countries, took part. Each ampoule of the International Standard of Amikacin is defined as containing the activity of 50 600 International Units of Amikacin.

International collaborative study for the establishment of the second International Reference Preparation of plasmin.

An international collaborative study involving seven laboratories was undertaken to assess the suitability of a freeze-dried preparation of human plasmin to replace the current International Reference Preparation (IRP) for plasmin. Chromogenic and fibrinolytic assays were used by all participating laboratories to assess the potencies of the Proposed International Reference Preparation (PIRP) and two other freeze-dried plasmins, one of human and one of porcine origin. The data suggest that the PIRP is a more suitable standard for plasmin than the IRP in that the former binds to fibrin whereas only 50% of the latter binds.

Stability of the 4th International Standard for Insulin.

The stability of the (W.H.O.

The international standard for rolitetracycline.

An International Standard for Rolitetracycline has been established and the international unit of this antibiotic defined as the activity contained in 0.001004 mg of the international standard. The definition of the international unit was based on the results of a collaborative assay in which 8 laboratories in 6 different countries participated; a total of 133 assays were performed.

The second international reference preparation of procaine benzylpenicillin in oil with aluminium monostearate.

The second International Reference Preparation of Procaine Benzylpenicillin in Oil with Aluminium Monostearate was established in replacement of the first international reference preparation. The blood-level duration test (WHO Requirements for Biological Substances, No. 9), used to evaluate batches of manufactured material in relation to this reference preparation, was revised to relate to the new reference preparation.

The second international standard for chlortetracycline.

As supplies of the International Standard for Chlortetracycline were practically exhausted, it was replaced. The potency of the second international standard was defined on the basis of an international collaborative assay comprising 157 individual assays performed in 9 laboratories in 6 countries. The mean potencies obtained in the participating laboratories, although they varied by only 7%, were heterogeneous.

The second international reference preparation of erythropoietin, human, urinary, for bioassay.

A collaborative study of the second international Reference Preparation of Erythropoietin, Human, Urinary, for Bioassay was carried out in 10 laboratories. Combined potency estimates obtained by comparison with the International Reference Preparation, indicate that ampoules of the second Preparation contain 10.0 IU (weighted mean potency) or, taking the unweighted mean potency, 9.

Evaluation of the blood level duration properties of procaine benzylpenicillin in oil with aluminium monostearate (PAM).

The study of procaine benzylpenicillin in oil with aluminium monostearate (PAM) described in this paper was undertaken to devise laboratory assay methods, based on animal tests, to evaluate those properties of PAM responsible for the persistence of penicillin in the circulation, as a preferable substitute for the existing test in man. Comparative studies of a number of batches of PAM in man proved, with statistical certainty, that the duration of the blood level of penicillin which they produced varied from batch to batch. The chemical and physical properties of the batches gave inadequate characterization and were of no value in assessing material for clinical use.

The international standard for oleandomycin.

At the request of the WHO Expert Committee on Biological Standardization a batch of oleandomycin was submitted to an international collaborative study in six laboratories situated in four countries. In this study the material was assayed by plate diffusion methods, which varied in details of technique and design, against the US Food and Drug Administration's reference preparation for oleandomycin. On the basis of the results obtained the material has been established as the International Standard for Oleandomycin and the International Unit of Oleandomycin is defined as the activity in 0.

THE SECOND INTERNATIONAL STANDARD FOR PROLACTIN.

In 1953 the WHO Expert Committee on Biological Standardization asked the National Institute for Medical Research, London, to collect and study suitable material to replace the First International Standard for Prolactin, stocks of which were running low. This paper reports the nature and handling of the proposed replacement material, its potency as determined by comparison with the First International Standard by international collaborative assay, and its establishment as the Second International Standard for Prolactin, with a defined potency of 22 International Units per mg. The International Unit of Prolactin is defined as the activity contained in 0.