Characterization of binding sites for a GnRH-agonist (buserelin) in human breast cancer biopsies and their distribution in relation to tumor parameters

Summary Gonadotropin-releasing hormone analogs (GnRH-A) have been added to the armentarium in the therapy of hormone-dependent breast cancer in premenopausal women. The effect of chronic GnRH-A-treatment in premenopausal women is based on the suppression of the hypothalamus-pituitary-ovarian axis and the reduction of sex-steroid serum levels. In addition, a number of experimental and clinical data have been accumulated indicating a direct action of GnRH-A on breast cancer cells and tissue. In this study we analyzed 235 human breast cancer biopsies for specific GnRH-A-binding. We demonstrate high affinity GnRH-A binding sites in human breast cancer tissues. The evaluation of clinical data showed no correlation of the level of GnRH-A-binding with classical tumor parameters.     

Changes in bone in a model of spinal cord injury

Bone calcium, histomorphometry, and mechanical strength were evaluated in a model of spinal cord injury. Cortical bone area and rates of formation and apposition at the tibiofibular junction (TFJ) and midshaft of the humerus were measured at 35–42, 42–77, and 77–94 days after transection of the spinal cord. All comparisons were between the animals with a spinal lesion and control animals. A 0.34% difference in the length of the tibia of the two groups of animals was observed, the dry weight of the tibia was 28.4% less in rats with a lesion, and there was no significant difference in the amount of calcium per milligram of bone. At 35 days after surgery, the cortical area in the midshaft of the humerus was slightly less (11%) in rats with a lesion, but by 94 days there was no difference in cortical or medullary area. The final (day 94) cortical area at the TFJ in rats with a lesion was less than that in the controls. Bone formation at the TFJ was similar in both groups in the period of 35–42 days and was similar at 77–94 days in the animals with a lesion, and rates of formation and apposition were greater in the humerus of rats with a lesion; the rates did not differ significantly between groups at either site. At 94 days, trabecular bone area in the tibial metaphysis was 41% less in rats with a lesion. Mechanical parameters were significantly less in the femora, but not the humeri, of rats with a lesion.     

Confusion of identification of o,p′-Kelthane as heptachlor in orange rind extractives

Conclusions Both the glc and the tlc data prove that the unknown compound in the rind of Kelthane-treated oranges was not heptachlor. While the characterization is not absolutely conclusive, there can be no reasonable doubt that it iso,p′-Kelthane, known to be present in technical grade Kelthane. Other workers, using glc, reportedp,p′- ando,p′-Kelthane in the ratio of 100∶1 in 21 market fruit samples from different areas of Southern California. By analogy with DDT, if technical grade Kelthane is assumed to contain up to 20% of theo,p′-isomer this ratio found on fruits treated months previously means that on and in oranges theo,p′-isomer has much the longer half-life (RL₅₀) of the two isomers. On the other hand, approximately equal half-lives are indicated for the two isomers in soil. This brief study emphasizes the need for checking on gas chromatographic data by a more specific method and clearly demonstrates again that improper interpretation of data may be avoided by using at least two columns possessing different retention characteristics for the compounds of interest.     

Evaluation of a rubber-base impression material.

A laboratory experiment has been described that utilized materials found in most dental offices and that was designed to evaluate a distinctly different polysulfide impression material. In this experiment the largest duplicating errors were produced with use of the stock tray and single-mix technique recommended by the manufacturer. This study therefore supports the use of the custom tray and double-mix technique for dental duplication procedures utilizing Neo-Plex impression material. Further investigation is necessary before stock trays and single-mix techniques can be recommended for routine use in fixed prosthodontics.     

Worker environment research: Dioxathion (delnav®) residues on and in orange fruits and leaves,in dislodgable particulate matter,and in the soil beneath sprayed trees

Deposits and residues of dioxathion disappear at similar rates on and in the rind of oranges and the leaves of orange trees; dislodgable residues on the leaves dissipate at the same rate as the penetrated residues. This fact is important in evaluating the potential hazard to workers in treated groves because their exposure to pesticide residues is principally through the dislodgable residues. Samples of vapor and particulate matter taken during violent shaking of the trees show that the exposure of workers is almost entirely through contact with, and inhalation of, particulate matter, dermal contact probably being the more important. In one experiment, pickers were used in trees sprayed with dust containing no toxicant to determine the actual weights of dust that are inhaled (using Unico air samplers) and that accumulate on their bare arms (by washing at ten-minute intervals). The data show that several times as much dust is contacted dermally than is inhaled. Washing the entire trees with a dilute detergent solution removes a significant part of the dislodgable residue; as much as 30 percent is removed 46 days after spraying. The data presented in this paper provide a guide for toxicologists to permit the design of tests required to evaluate hazards workers encounter in pesticide-citrus groves.