1,2-Dihydro-2,2,4-trimethylquinoline (TMQ) was evaluated in a 2-year study in which groups of 60 male or female F344 rats received 0, 36 or 60 mg kg(-1) (0, 0.022, or 0.037 mg cm(-2)) and groups of 60 male or female B6C3F1 mice received 0, 3.6 or 10 mg kg(-1) (0, 0.00136, 0.00435 mg cm(-2)) in acetone by topical administration. Survival of all treated groups was comparable to survival of controls. Mean body weights of female rats were lower than those of controls throughout the study but mean body weights of male rats and male and female mice were comparable to the mean body weights of controls. No neoplasms of the skin were observed in any group of rats or mice. Acanthosis at the site of application was increased in male and female rats that received 60 or 100 mg kg(-1) and hyperkeratosis was increased in female rats that received 60 mg kg(-1). The incidences of renal tubule adenoma and renal tubule adenoma or carcinoma were increased significantly in the 60 and 100 mg kg(-1) groups of male rats. There were no neoplastic or non-neoplastic lesions in mice associated with exposure to 1,2-dihydro-2,2,4-trimethylquinoline. In a 1-year initiation-promotion study, groups of 30 female SENCAR mice received an initiating dose of 50 mg kg(-1) 1,2-dihydro-2,2,4-trimethylquinoline followed by promotion with 12-O-tetradecanoylphorbol-13-acetate (TPA), or an initiating dose of 7,12-dimethylbenzanthracene (DMBA) followed by promotion with 5, 10 or 25 mg kg(-1) 1,2-dihydro-2,2,4-trimethylquinoline. Other groups served as initiator control, promoter control, vehicle control and positive control (DMBA initiation, TPA promotion). In this system, 1,2-dihydro-2,2,4-trimethylquinoline-initiated skin was not promoted by TPA, and DMBA-initiated skin was not promoted by 1,2-dihydro-2,2,4-trimethylquinoline.

Adenoma↗

PubMedDate not supplied

Technique for increased granulocyte recovery from human whole blood by counterflow centrifugation elutriation I. In vitro analyses.

Human granulocytes were isolated from 120 ml of whole blood by a modified counterflow centrifugation-elutriation (CCE) technique. Overall recovery of isolated granulocytes averaged 2.82 +/- 0.25 x 10(8) cells or 77 per cent yield from whole blood with 96 per cent granulocyte purity and 4 per cent mononuclear leukocytes. The granulocyte fraction was assayed in vitro to determine chemotactic response, stimulated oxygen consumption in the presence of latex beads, bactericidal capacity, and enzyme activities. Cellular integrity was determined by scanning and transmission electron microscopy as well as by cell volume analysis. The data suggest that granulocytes isolated by CCE suffered no discernible loss of function or morphologic damage. The granulocytes are free of platelets and most mononuclear leukocytes and erythrocytes, and have not been exposed to sedimenting agents or surface adhesive agents such as dextran, nylon or glass wool.

Blood Bactericidal Activity↗

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Human granulocyte isolation by continuous flow centrifugation leukapheresis and counterflow centrifugation elutriation (CFCL/CCE).

Human granulocytes (PMNL) isolated by continuous flow centrifugation leukapheresis (CFCL) were further purified by counterflow centrifugation elutriation (CCE). Studies were conducted to determine the maximal granulocyte capacity of the 4.5-ml elutriation chamber and to determine the efficiency of granulocyte recovery from CFCL concentrates. The maximal capacity of the elutriation chamber was determined to be 1.30 x 10(9) granulocytes with a 98.8 percent granulocyte purity and a 51:1 PMNL/RBC ratio. The efficiency of recovery was 82.2 percent with a 95.1 percent granulocyte purity and a 68:1 PMNL/RBC ratio. The CCE flow system was designed to allow continuous elutriation runs without need of breakdown time between runs. In four to five hours, approximately 4 to 5 x 10(9) granulocytes can be isolated with purity in excess of 95 percent. In vitro analysis of the viability and function of CFCL/CCE-isolated granulocytes indicates that the morphologic integrity and physiologic function were not comprised as a result of the combined isolation procedure relative to granulocytes isolated by CCE from whole blood samples. Granulocytes were held at 4 to 6 C for 16 to 24 hours in granulocyte storage medium (GSM) plus 20 percent autologous plasma at concentrations of about 6 x 10(6) PMNL/ml prior to in vitro analysis.

Blood Bactericidal Activity↗

PubMedDate not supplied

Effect of plastic containers on liquid preservation of human granulocytes. I. With and without deoxyribonuclease and hydrocortisone.

We have characterized the effects of four types of plastic polymer containers--polyvinyl chloride (PL-146), bioriented-biaxial polyolefin, ethylene-vinyl acetate, and polypropylene--on the in vitro recovery, viability, membrane integrity, and phagocytosis of human granulocytes (PMNL). Cells were collected by continuous-flow centrifugation leukapheresis (CFCL), then further isolated by counterflow centrifugation-elutriation (CCE), and stored at 4 to 6 C for up to 14 days at concentration of 6 X 10(6) PMNL/ml in medium with or without hydrocortisone (HC) or deoxyribonuclease (DNAase). Regardless of the containers, there were no significant differences observed in the responses of PMNL within the first 48 hours of storage. However, PMNL stored in the polyvinyl chloride (PL-146) containers either with or without HC and DNAase maintained a significant higher viability and slower mean cell volume (MCV) expansion rate after 48 to 96 hours compared with that stored in other containers. The phagocytic response was comparable in surviving PMNL from all containers during the first seven days. Addition of HC and DNAase to the storage medium reduced the rate of PMNL volume expansion in all containers, improved the viability in all but the polypropylene containers, but had no effect on the phagocytic response. Since the results show a strong correlation between the rate of PMNL volume expansion during storage and subsequent loss of PMNL viability and function, the containers made with PL-146 polyvinyl chloride are superior to those made of bioriented-biaxial polyolefin, ethylene-vinyl acetate, or polypropylene.

Blood Preservation↗

PubMedDate not supplied

Survey on the current use of leukapheresis and the collection of granulocyte concentrates.

This study was designed to define leukapheresis practice. A voluntary questionnaire on leukapheresis was sent to 280 FDA-registered blood-collecting establishments performing leukapheresis. Of the facilities questioned, 67.9 percent responded. The survey results indicate that most facilities use intermittent-flow blood cell separators, while 22.6 percent use more than one separation method. Establishments routinely use 6% hydroxyethyl starch (HES 450/0.70) and the majority using trisodium citrate as the anticoagulant. Forty-eight percent use corticosteroids, primarily dexamethasone, to pretreat the donor. The frequency of donation was not specified by 25.3 percent of the report. Forty-two percent chose an individual donation frequency of two times per week. A limit on the total number of donations allowed per donor was not specified by 78.4 percent of the facilities. Community blood banks (including regional centers) performed 55.6 percent of all leukocyte concentrate collections. The donor reaction incidence was of 3.64 percent. Hospitals, of all types, performed 37.8 percent of the collections. The adverse reaction rate ranged from 2.84 to 9.72 percent. Adverse reactions occurred in donors 54.9 times per 1000 procedures. Ninety-four percent of reported reactions were mild, whereas moderate and severe reactions accounted for 5.9 and 0.4 percent, respectively. Granulocyte yields varied by the type procedure and the use of corticosteroids as well as among facilities. The majority (56.3%) held leukocytes at 22 to 25 degrees C prior to transfusion, while most of the remainder stored at 4 degrees C.

Adrenal Cortex Hormones↗

PubMedDate not supplied

The use of transgenic animals in cancer testing.

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Animals↗

PubMedDate not supplied

Phenolphthalein induces thymic lymphomas accompanied by loss of the p53 wild type allele in heterozygous p53-deficient (+/-) mice.

Epidemiology studies have indicated that many human cancers are influenced by environmental factors. Genetically altered mouse model systems offer us the opportunity to study the interaction of chemicals with genetic predisposition to cancer. Using the heterozygous p53-deficient (+/-) mouse, an animal model carrying one wild type p53 gene and one p53 null allele, we studied the effects of phenolphthalein on tumor induction and p53 gene alterations. Earlier studies showed that phenolphthalein caused carcinogenic effects in Fisher 344 rats and B6C3F1 mice after a 2-yr dosing period (Dunnick and Hailey, Cancer Res. 56: 4922-4926, 1996). The p53 (+/-) mice received phenolphthalein in the feed at concentrations of 200, 375, 750, 3,000, or 12,000 ppm (approximately 43, 84, 174, 689, or 2,375 mg/kg body weight/day or 129, 252, 522, 2,867, or 7,128 mg/m2 body surface area/day) for up to 6 mo. A target organ cancer site that accumulated p53 protein in the B6C3F1 mouse (i.e., thymic lymphoma) was also a target site for cancer in the p53 (+/-) mouse. In the p53 (+/-) mouse, treatment-related atypical hyperplasia and malignant lymphoma of thymic origin were seen in the control and dosed groups at a combined incidence of 0, 5, 5, 25, 100, and 95%, respectively. Twenty-one of the thymic lymphomas were examined for p53 gene changes, and all showed loss of the p53 wild type allele. Chemical-induced ovarian tumors in the B6C3F1 mouse showed no evidence for p53 protein accumulation and did not occur in the p53 (+/-) mouse. The p53-deficient (+/-) mouse model responded to phenolphthalein treatment with a carcinogenic response in the thymus after only 4 mo of dosing. This carcinogenic response took 2 yr to develop in the conventional B6C3F1 mouse bioassay. The p53-deficient (+/-) mouse is an important model for identifying a carcinogenic response after short-term (< 6 mo) exposures. Our studies show that exposure to phenolphthalein combined with a genetic predisposition to cancer can potentiate the carcinogenic process and cause p53 gene alterations, a gene alteration found in many human cancers.

Animals↗

PubMedDate not supplied

Tripropylene glycol diacrylate but not ethyl acrylate induces skin tumors in a twenty-week short-term tumorigenesis study in Tg.AC (v-Ha-ras) mice.

The toxicity of the esters of acrylic acid are poorly understood even though significant human exposure occurs. To conduct rapid comparative short-term bioassays, we used the Tg.AC (v-Ha-ras) transgenic mouse model to determine the toxicity and potential carcinogenicity of tripropylene glycol diacrylate (TPGDA) alone and in a reference formulated ultraviolet radiation curable lacquer (Lacquer A), which is used in the ultraviolet radiation curable surface coatings. For comparison, ethyl acrylate (EA) was used as a reference acrylate. Insertion of the zeta-globin promoted v-Ha-ras transgene into the FVB mouse genome (Tg.AC) introduced a defined genetic lesion, which is critical but insufficient by itself to induce benign or malignant tumors in the skin unless activated. Activation and expression of the transgenic ras oncoprotein in this mouse line induces a dose-related increase in papillomas (skin reporter phenotype) within weeks. Based on dose-related increases in skin hyperplasia following dermal exposure to EA, TPGDA, or Lacquer A (applied equimolar for TPGDA concentration), the dosing regimen was selected. Starting at 12 wk of age, the agents were administered topically (200 microliters of acetone vehicle) 3 times/wk for 20 wk to the shaved dorsal skin of female Tg.AC mice (n = 10/group). TPGDA and reference Lacquer A (equimolar for TPGDA) at 5 or 10 mumoles/mouse but not EA (60, 300, or 600 mumoles/mouse) or TPGDA or Lacquer A at 1 mumole/mouse induced a dose-related increase in papillomas between 6 and 12 wk of treatment that reached a maximum number of papillomas per mouse between 19 and 20 wk of treatment. These results indicate that TPGDA is significantly more potent than EA for inducing the skin reporter phenotype and may be predicted to be carcinogenic in long-term cancer bioassays at the site of contact.

Acrylates↗

PubMedDate not supplied

Transponder-induced sarcoma in the heterozygous p53+/- mouse.

Heterozygous p53+/- transgenic mice are being studied for utility as a short-term alternative model to the 2-yr rodent carcinogenicity bioassay. During a 26-wk study to assess the potential carcinogenicity of oxymetholone using p-cresidine as a positive control, glass/polypropylene microchips (radio transponder identification devices) were subcutaneously implanted into male and female p53+/- mice. During week 15, the first palpable mass was clinically observed at an implant site. This rapidly growing mass virtually quadrupled in size by week 25. Microscopic examination of all implant sites revealed that 18 of 177 animals had a subcutaneous histologically malignant sarcoma. The neoplasms were characterized as undifferentiated sarcomas unrelated to drug treatment, as indicated by the relatively even distribution among dose groups, including controls. An unusual preneoplastic mesenchymal change characterized by the term "mesenchymal dysplasia" was present in most groups and was considered to be a prodromal change to sarcoma development. The tumors were observed to arise from dysplastic mesenchymal tissue that developed within the tissue capsule surrounding the transponder. The preneoplastic changes, including mesenchymal dysplasia, appeared to arise at the transponder's plastic anchoring barb and then progressed as a neoplasm to eventually surround the entire microchip. Capsule membrane endothelialization, inflammation, mesenchymal basophilia and dysplasia, and sarcoma were considered unequivocal preneoplastic/neoplastic responses to the transponder and were not related to treatment with either oxymetholone or p-cresidine.

Anabolic Agents↗