Electrochemotherapy in veterinary oncology

Electropermeabilization is a method that uses electric field pulses to induce an electrically mediated reorganization of the plasma membrane of cells. Electrochemotherapy combines local or systemic administration of chemotherapeutic drugs such as bleomycin or cisplatin that have poor membrane permeability with electropermeabilization by direct application of electric pulses to the tumors. Preclinical studies have demonstrated excellent antitumor effectiveness of electrochemotherapy on different animal models and various tumor types, minimal toxicity, and safety of the procedure. Based on results of preclinical studies, clinical studies were conducted in human patients, which demonstrated pronounced antitumor effectiveness of electrochemotherapy with 80-85% objective responses of the treated cutaneous and SC tumors. Clinical studies in veterinary oncology have demonstrated that electrochemotherapy is very effective in the treatment of cutaneous and SC tumors of different histologic types in cats, dogs, and horses. The results of these studies have also demonstrated approximately 80% long-lasting objective responses of tumors treated by electrochemotherapy. Primary tumors of different histologic types were treated. Electrochemotherapy in veterinary oncology has future promise to be highly effective, and could be used to treat primary or recurrent solitary or multiple cutaneous and SC tumors of different histology or as an adjuvant treatment to surgery.     

Some aspects of clinical pharmacokinetics in veterinary medicine. I

This series of two review articles deals with general aspects of the mechanisms which govern absorption and distribution of drugs within the body, and the kinetics of drug metabolism and excretion. Emphasis is given to the verification of pharmacokinetic principles in domestic animals, and the clinical applications which proceed therefrom. In the first part, the concept of the two compartment and three compartment models for drug disposition are introduced and developed to demonstrate the mathematical models which may be derived to describe the kinetics of drug distribution and elimination. In the second part bioavailability and drug dosage will be considered.     

Cancer antigen 15/3: possible diagnostic use in veterinary clinical oncology. Preliminary study

The cancer antigen 15/3 is a mucin that is associated with the cell membrane, encoded by the MUC1 gene, and recognized by the monoclonal-clone DF3 antibody. The latter antigen was discovered to be specific for both the identification of human mammary neoplasia and during patient follow-up evaluations. The aim of this study is to report and compare the results of the application of direct chemiluminescence in canine blood sera and the kit utilized in human medicine for the determination of Ca 15/3 to verify the diagnostic efficiency of the kit in cases presenting mammary tumors. Specifically, CA 15/3 has proven to be measurable in all samples assayed to distinguish clinically healthy subjects from those with mammary neoplasia.

     

Some aspects of the teratogenicity of veterinary drugs

The possible teratogenic effect of drugs used in veterinary medicine is important for two main reasons: safety for the target animals and residue risks for the consumers of animal products.The general laws of chemical teratogenesis are: specific sensitivity, smallness of the teratogenic dose, existence of a sensitive period, and single dose effect. They are illustrated by different examples in domestic animals. In most cases (retinol, griseofulvin), the teratogenic doses are obviously higher than the therapeutic ones; on the contrary, in some circumstances (parbendazole, cambendazole), the safety margin is relativley low and requires strict observance of the recommended dosage.It is pointed out that metabolism is a determining factor of teratogenesis and is related to drug residue toxicity. Yet, it is experimentally possible to distinguish inactive metabolites and teratogenic metabolites that may be present in meat and milk. Consequently, a more appropriate evaluation of risks is possible, compared to the classical method that uses total radioactivity levels. These nitions are illustrated by numerous examples of anthelmintics.     

World veterinary manpower: comparative aspects.

The number of veterinarians in relation to livestock units, human population, milk and meat production and gross national product for 93 countries is presented. The structure of veterinary manpower is discussed and information on veterinary involvement with companion animals and public health is given. For 23 countries representing all the continents, the number of livestock units, human population and gross national product per veterinary school are presented.     

Clinical indications and applications of radiotherapy and hyperthermia in veterinary oncology

The response of dogs and cats with neoplasia to radiation therapy has improved significantly during the past 10 years. This has largely been due to more aggressive radiation therapy treatment schedules, more accurate planning, and refinement of clinical indications. Sufficient numbers of dogs and cats irradiated with curative intent have not been accumulated to yet define the full impact of more aggressive therapy. However, many tumors will likely remain resistant to irradiation because of concomitant normal tissue injury that must be minimized. Systematic investigation of combination therapy (surgery, radiation, chemotherapy, and hyperthermia) should succeed in reducing local tissue side effects and increased local tumor control. A comprehensive approach to tumor management begins with decisions thoughtful of optimal treatment for suspected malignant tumors even at the time of initial examination and client counseling. An incisional biopsy provides essential information to determine the therapeutic course and should be considered prior to initial excision. More aggressive treatment, of even small tumors, early in the clinical course will lead to prolonged tumor control. Radiation therapy should be considered fundamental in the comprehensive treatment plan of many solid tumors.