Effects of cancer chemotherapeutic agents on endocrine organs and serum levels of estrogens, progesterone, prolactin, and luteinizing hormone.

The effects of the following cancer chemotherapeutic agents on serum hormonal levels, estrous cycles, and endocrine organs were studied in mature, normal Sprague-Dawley rats by radioimmunoassay, vaginal smear examination, and organ weight end point: estradiol mustard (NSC 112259), testosterone mustard (NSC 112260), phenoestrin (NSC 104469), methotrexate (NSC 740), 5-fluorouracil (NSC 19893), vinblastine (NSC 49842), vincristine (NSC 67574), nitrogen mustard (NSC 762), and 1,3-bis(2-chloroethyl)-1-nitrosourea (NSC 409962). Following 2 weeks of treatment, estradiol-17beta levels were markedly elevated by all compounds except testosterone mustard and nitrogen mustard, which caused a decrease. Estrone levels were elevated by methotrexate, 5-fluorouracil, vinblastine, vincristine, nitrogen mustard, and 1,3-bis(2-chloroethyl)-1-nitrosourea, but were lowered by estradiol mustard. Progesterone levels were elevated only by estradiol mustard and testosterone mustard and were not affected by other compounds. Prolactin surge during proestrus was suppressed by phenesterin and methotrexate. Luteinizing hormone levels were lowered by methotrexate and nitrogen mustard. Estrous cycles of rats treated with estradiol mustard were arrested at proestrus, and the uterine and pituitary weights of these rats markedly increased. Uterine weight loss was significant following treatment with testosterone mustard, 5-fluorouracil, and nitrogen mustard. Thyroid weight was reduced by all compounds except methotrexate and vinblastine. Significant increases in pituitary weights occurred following treatment with all compounds except 1,3-bis(2-chloroethyl)-1-nitrosourea. The effects on ovarian and adrenal weights were minimal although significant by some compounds. Thus, in addition to their direct antitumor effects, these agents also produced changes in endocrine system which may be synergistic or antagonistic to the chemotherapy of endocrine-responsive neoplasms.

Effect of androgens on maturation and metabolism of erythroid tissue.

Specific changes taking place in the erythroid tissue following depletion or replacement of androgens were studied in rats. The reduction of testosterone levels in blood of orchiectomized animals did occur in conjunction with a decline of erythrocyte glucose-6-phosphate (G6P) and lactate levels. No evidence of anemia was observed. The subcutaneous administration of testosterone propionate (16.0 mg/kg) to orchiectomized rats restored, within 12 hours, blood testosterone levels as well as erythrocyte G6P levels and lactate production. The in vitro incorporation of glucose-1-14C into rat erythrocytes incubated with testosterone was comparable to that of control cells. A radioautographic study of rat erythroid marrow pulsed with glucose-1-14C showed a lower labeling when testosterone propionate was administered. The authors conclude that testosterone does directly affect glucose metabolism of erythroid cells, via the pentose shunt pathway. The possible role of the androgen-dependent enhancement of erythroid glycolysis is discussed in relation to the function of testosterone receptocytes present in marrow cells and a 17beta-hydroxysteroid dehydrogenase present in erythrocytes.

Genotoxic potential of acephate technical: in vitro and in vivo effects.

The genotoxic potential of acephate technical (AT) in vitro and in vivo has been studied in bioassays detecting primary DNA damage, chromosomal alterations, and gene mutation. Results from in vitro assays have ranged from negative to weakly positive; AT is apparently a direct-acting agent in these tests. However, expressed in terms of molar potency, AT has generally been at least 100-1000 times less potent than known positive mutagens tested in vitro. Following in vivo exposure at maximum tolerated doses, AT did not induce chromosomal aberrations, sister chromatid exchange, or micronuclei in mouse bone marrow cells; a dominant lethal study in mice was also negative. In a supplemental study, no induced chromosomal aberrations or sister chromatid exchange could be detected in lymphocytes from a pair of cynomolgus monkeys following exposure to AT at a low dose level for 20 days. At dose levels limited by toxicity, no positive results were observed for induction of sex-linked, recessive lethality in D. melanogaster. Acephate technical (ORTHENE) appears to present little or no genetic hazard to in vivo mammalian systems.

Comparative usefulness of cytology and peroxidase activity in conjunction with carcinoembryonic antigen levels for the diagnosis of mammary cancer.

Diagnosis of cancer via measurement of carcinoembryonic antigen (CEA) levels has been unreliable in early neoplastic stages. In order to improve diagnostic reliability, other cytological parameters were examined with CEA. Fifty specimens of effusion fluid were obtained from 40 hospitalized patients and the levels of CEA determined by radioimmunoassay in conjunction with application of an immunoperoxidase procedure. Simultaneous morphologic assessment was performed without knowledge of the immunoassay findings. In 8 documented cases of mammary cancer, all effusion fluid specimens had CEA levels of 16-1074 ng/ml, 7 cases had morphologically positive cells, but only 3 had a peroxidase positive reaction. Except for one case of ovarian papillary adenocarcinoma, the remaining patients were cancer free, had CEA levels of less than 15 ng/ml and only 2 cases (including the ovarian tumor patient) gave positive peroxidase responses. The presence of mammary metastatic duct carcinoma correlated 88% with CEA measurements but peroxidase response was not diagnostically helpful.

Immune response of hospital workers to hepatitis B vaccine.

Hepatitis B vaccine (Heptavax-B vaccine, Merck Sharp and Dohme) was given by injection into the buttock of 109 healthy workers in a community hospital according to the schedule of the U.S.A. Centers for Disease Control. In only 26% of those between 41 and 65 years of age was antibody to hepatitis B surface antigen found after the full course of vaccination whereas 74% of those aged 18-40 years had detectable antibody. We did not find any significant difference between the responses of males and females in either age group. The unusually poor response may be related to injections being given into the buttock rather than the deltoid region of the arm. We, therefore, recommend that injections of hepatitis B vaccine should be given into the deltoid muscle and that vaccinees should be tested after vaccination for evidence of immunity.

Chlorthalidone pharmacodynamics in beagle dogs.

A pharmacodynamic approach was employed to examine the diuretic effect of chlorthalidone in beagle dogs and to identify parameters necessary for optimization of an oral dosage formulation of this drug. The extensive partitioning of chlorthalidone into erythrocytes was shown to be noninstantaneous, with an in vitro partitioning half-life of 18 min. In vivo studies using oral and intravenous solutions confirmed this finding. Additionally, the diuretic effect was demonstrated to be related to the drug concentration in the plasma fraction. These studies led to the development of a relevant pharmacokinetic model which highlighted the importance of the oral absorption rate on the diuretic efficacy of chlorthalidone. A novel, rapidly dissolving, stabilized, amorphous chlorthalidone tablet formulation was compared to various oral solution and tablet formulations. Pharmacokinetic analysis by classical compartmental models and by moment techniques demonstrated that the rapidly dissolving tablet formulation was bioequivalent to an oral solution of chlorthalidone. Preparations containing crystalline chlorthalidone are shown to be incompletely absorbed, and the rates of absorption favor partitioning into the erythrocyte fraction. It is projected from the pharmacodynamic model that the novel chlorthalidone preparation optimizes plasma levels necessary to invoke a diuretic response.

Long-term controlled delivery of levonorgestrel in rats by means of small biodegradable cylinders.

Hormone release rates from biodegradable cylindrical implants consisting of a physical matrix of [14C]levonorgestrel and copolymers of [3H]lactic and glycolic acids have been monitored in rats. Two copolymers were evaluated: one consisted of 90 parts L-lactide/10 parts glycolide (90L/10G) containing 33 or 50% hormone by weight, and the other of 50 parts DL-lactide/50 parts L-lactide (50DL/50L) containing 50% hormone. For each system, 4-6 rods (0.8 x 16 mm) providing 19 mg of steroid per rat were subcutaneously implanted into the scapular regions of 5 rats, and 14C and 3H in faeces and urine were determined weekly for 90-724 days. An initial burst of hormone release, peaking at approximately 90 microgram day-1, occurred in the first two weeks. This was followed by an approximately 10-30 microgram day-1 for the 90L/10G system containing 33% hormone, a more uniform rate of approximately 25 microgram day-1 for the 50DL/50L system and the highest rate of approximately 40 microgram day-1 for the 90L/10G system containing 50% hormone. 3H and 14C in residual implants of 90L/10G with 33% hormone removed from animals dying of natural causes during the test were assayed. For this system 3H activity decreased by over 50% within 250 days, compared with < 25% loss in 14C activity. The amounts of 3H and 14C released were similar over much of the subsequent test period. At the end of the test both polymer and drug were essentially depleted. All animals with the 50DL/50L system died late in the test period. Between days 609 and 724 from 13.7-27.2% initial 14C and from 10.0-22.1% initial 3H was measured in recovered rods. Microscopic inspection of recovered rods showed a loss of core material and tissue encapsulation. There were no signs of local tissue irritation or systemic toxicity.

Nontuberculous mycobacterial infection attributable to Mycobacterium intracellulare serotype 10 in two rhesus monkeys.

Infection with Mycobacterium intracellulare serotype 10 was diagnosed in 2 rhesus monkeys (Macaca mulatta) in a closed colony of 90 animals. The clinicopathologic presentation in 1 animal with advanced disease was characterized by a precipitous weight loss, therapeutically unresponsive diarrhea, anemia, weakness, prostration, refractory tuberculin tests (using mammalian old tuberculin and M bovis purified protein derivative tuberculin), and disseminated granulomas in the lungs, spleen, liver, kidneys, lymph nodes, salivary glands, and intestines. The lamina propria throughout the large and small intestines was infiltrated with mycobacteria-laden macrophages. Severe hypoproteinemia, hypoalbuminemia, hypoglobulinemia, mild hypocalcemia, and edema were compatible with a malabsorption-like syndrome. The 2nd animal was clinically normal, but a weak positive tuberculin reaction to M bovis purified protein derivative at 72 hours necessitated euthanasia. This animal's disease was characterized by microgranulomas in the lungs, bronchial lymph nodes, liver, and pancreas, without involvement of the gastrointestinal tract. There was no evidence of M intracellulare infection in the remaining 88 animals in the colony, as determined by mycobacterial cultures of tracheobronchial washings, additional tuberculin testing, thoracic radiography, and mycobacterial culture of the drinking water. Tuberculin testing and thoracic radiographs of personnel working with the nonhuman primates were also negative. These cases were considered to be important because both animals were infected with the same serotype and because there has been an increasing number of isolations of this organism in human infections throughout Massachusetts. Drug-sensitivity testing revealed the organism to be sensitive to cycloserine and resistant to isoniazid, rifampin, ethambutol, streptomycin, kanamycin, and pyrazinamide.

The concept of induction and elicitation as an immunotherapeutic approach.

The concept of "induction and elicitation," propounded by Stuart Mudd, circumvents the dangers of infecting the immunologically impaired individual without abrogating the effectiveness of the antigenic stimulus provided by an initial infection with living organisms. Mudd's concept utilizes the ubiquitous and naturally established delayed type hypersensitivity to Staphylococcus aureus as the primary induction step for the more effective use of bacterial fractions, such as staphylococcal phage lysate, a potent immunizing agent, commercially licensed and available, in the subsequent elicitation of a nonspecific, cell-mediated immune response. The results of an exploratory study in which induction and elicitation were applied as an immunotherapeutic modality, in combination with surgery, in a metastasizing animal tumor model (the F344 rat) are presented.

Influence of surgery, irradiation, chemotherapy, and immunotherapy on growth of a metastasizing rat mammary adenocarcinoma.

Based upon the hypothesis that a factor most pertinent to the absence of an effective immune response in cancer is the inadequacy of the antigenic stimulus provided by the neoplasm, either in terms of weak immunogenicity of the tumor antigen or of the necessary antigen mass available to the reticuloendothelial tissues at any one time for effective sensitization, the host immune response capabilities were stimulated within a time frame synchronous with a greater release of tumor antigens. In the treatment of a metastasizing, solid tumor model syngeneic with F344 rats, immunotherapy was most effectively applied in combinations with chemotherapy and/or localized radiotherapy, therapeutic modalities that induced a degree of oncolysis and tumor resorption. Surgery combined with chemotherapy permitted evaluation of therapeutic effects against metastases. The methanol-soluble fraction of Mycobacterium butyricum was used as the nonspecific immunologic adjuvant.