In order to study the heterogeneity of the metastatic and tumorigenic behaviors of malignant neoplasms, we have iso lated a series of cloned cell lines from a primary nickel-induced rat rhabdomyosarcoma. The growth characteristics in vitro and in vivo and metastatic capacity following s.c. or i.v. injection of cells were compared to those of the parental cell line. Differ ences between the clon...

Identifying the “right” dose is one of the most critical and difficult steps in the clinical development process of any medicinal drug. Its importance cannot be understated: selecting too high a dose can result in unacceptable toxicity and associated safety problems, while choosing too low a dose leads to smaller chances of showing sufficient efficacy in confirmatory trials, thus reducing the c...

Minimum alveolar concentration (MAC), served as the vital concept for standard measure of potency for inhaled volatile anesthetic agents, has been employed in anesthetic practice for more than 50 years. A re-consideration in the connotation and influence factors on MAC is introduced in this article. MAC actually indicates “median effective dose (ED50) for immobility”, but it is at least not com...

After the Chernobyl accident of 26 April, 1986, population dose assessment favours the view that the radiation risk of population effected by the early fallout would be different from that in regions contaminated later. Taking into account the short half-time of the most important radioactive iodine isotopes, thyroid disorders would be expected mainly to follow the early fallout distribution. A...

Inhalation of indoor radon has been recognized as one of the health hazards. In the present work a set of indoor radon measurements was carried out, in different Egyptian houses in Alexandria city, built of the same type of building materials, using time–integrated passive radon dosimeters containing LR-115 Type II solid state nuclear track detector. Measurements were carried out from October 2...

Radiotherapy is the most common treatment of cancer. It is also practised in combination with chemotherapy or immunotherapy. Although many cases are successfully treated, failures in local control do occur and even a modest improvement in the relative radiosensitivity of tumour cells would result in a substantial therapeutic gain. In addition, the presently practised fractionated dose schedule ...

In this paper, we consider identifying the minimum effective dose (MED) in a dose–response study when survival data are subject to random right-censorship, where the MED is defined to be the smallest dose level under study that has survival advantage over the zero-dose control. To this end, we suggest single-step-down testing procedures based on three different types of weighted logrank statist...

For many years antipneumococcal serum was administered in relatively small doses at intervals of 8 hours and injections were continued until the fever subsided (1). Such a slow method of giving antiserum necessitated a prolonged period of treatment and patients often succumbed to the pneumonia before they had been given adequate quantities of antibody. The importance of administering large dose...

The best conditions for synthesis of starch hydroxypropyl sulphate as per the dry method were firstly established. This was done through a thorough investigation into factors affecting the synthesis including concentrations of both the NaOH catalyst and the 2-hydroxy-3-chloropropyl sulphate along with duration and temperature of the reaction. The resultant newly synthesized 2-hydroxy-3-chloropr...