The development of an ethanol model using social insects I: behavior studies of the honey bee (Apis mellifera L.).

BACKGROUND: The purpose of this experiment was to test the feasibility of creating an animal model of ethanol consumption using social insects. Honey bees were selected as the model social insect because much is known about their natural history, physiology, genetics, and behavior. They are also inexpensive to procure and maintain. Of special interest is their use of communication and social organization. METHODS: Using both between- and within-experiment designs, studies were conducted with harnessed foragers to determine whether honey bees would consume ethanol mixed with sucrose (and, in some cases, water). Shuttle-box and running-wheel studies were conducted to examine the effect of ethanol on locomotion. The effect of ethanol on stinging behavior in harnessed foragers was investigated. The effect of ethanol on Pavlovian conditioning of proboscis extension was also investigated. Finally, in a self-administration study, foraging honey bees were trained to fly to an artificial flower containing ethanol. RESULTS: (1) Harnessed honey bees readily consume 1%, 5%, 10%, and 20% ethanol solutions; (2) 95% ethanol will also be consumed as long as the antennae do not make contact with the solution; (3) with the exception of 95% ethanol, consumption as measured by contact time or amount consumed does not differ in animals that consume 1%, 5%, 10%, and 20% ethanol solutions; (4) exposure to a lesser (or greater) concentration of ethanol does not influence consumption of a greater (or lesser) concentration; (5) consumption of 10% and 20% ethanol solutions decreases locomotion when tested in both a shuttle-box and running-wheel situation; (6) consumption of 1%, 5%, 10%, and 20% ethanol does not influence stinging behavior in harnessed foragers; (7) ethanol solutions greater than 5% significantly impair Pavlovian conditioning of proboscis extension; and (8) free-flying honey bee foragers will readily drink from an artificial flower containing 5% ethanol. CONCLUSIONS: The experiments on consumption, locomotion, and learning suggest that exposure to ethanol influences behavior of honey bees similar to that observed in experiments with analogous vertebrates. The honey bee model presents unique research opportunities regarding the influence of ethanol in the areas of language, social interaction, development, and learning. Although the behavioral results are interesting, similarity between the physiologic effects of ethanol on honey bees and vertebrates has not yet been determined.

The role of three dimensional functional lung imaging in radiation treatment planning: the functional dose-volume histogram.

PURPOSE: During thoracic irradiation (XRT), treatment fields are usually designed to minimize the volume of nontumor-containing lung included. Generally, functional heterogeneities within the lung are not considered. The three dimensional (3D) functional information provided by single photon emission computed tomography (SPECT) lung perfusion scans might be useful in designing beams that minimize incidental irradiation of functioning lung tissue. We herein review the pretreatment SPECT scans in 86 patients (56 with lung cancer) to determine which are likely to benefit from this technology. METHODS AND MATERIALS: Prior to thoracic XRT, SPECT lung perfusion scans were obtained following the intravenous injection of approximately 4 mCi of 99mcTc-labeled macro-aggregated albumin. The presence of areas of decreased perfusion, their location relative to the tumor, and the potential clinical usefulness of their recognition, were scored. Patients were grouped and compared (two-tailed chi-square) based on clinical factors. Conventional dose-volume histograms (DVHs) (DVFHs) are calculated based on the dose distribution throughout the computed tomography (CT)-defined lung and SPECT-defined perfused lung, respectively. RESULTS: Among 56 lung cancer patients, decreases in perfusion were observed at the tumor, adjacent to the tumor, and separate from the tumor in 94%, 74%, and 42% of patients, respectively. Perfusion defects adjacent to the tumor were often large with centrally placed tumors. Hypoperfusion in regions separate from the tumor were statistically most common in patients with relatively poor pulmonary function and chronic obstructive pulmonary disease (COPD). Considering all SPECT defects adjacent to and separate from the tumor, corresponding CT abnormalities were seen in only approximately 50% and 20% of patients, respectively, and were generally not as impressive. Following XRT, hypoperfusion at and separate from the tumor persisted, while defects adjacent to the tumor improved in several patients. In four patients who achieved a complete response scored by CT with chemotherapy prior to XRT, persistent hypoperfusion was present at and adjacent to the tumor site in three. Among 30 patients with cancers not arising in the lung (14 breast, 12 lymphoma, 4 others), perfusion defects were seen in only 4 (2 adjacent and 2 apart). Recognition of decreases in perfusion mainly impacted on treatment planning for a few patients with poor pulmonary function and limited target volumes. DVFHs have been useful in beam selection for patients with marked perfusion heterogeneities. CONCLUSIONS: Lung perfusion scans provide functional information not provided by CT scans that can be useful in designing radiation treatment beams that minimize incidental irradiation of the function regions of the lung. This approach appears to be most helpful in patients with gross intrathoracic lung cancer, especially those with small targets and relatively poor pulmonary function. One limitation of this approach is that some of the defects adjacent to the tumor site reperfuse following treatment, indicating that these scans identify perfusion rather than potential perfusion. Three dimensional functional data can be used to generate DVFHs that may be more predictive of the physiological consequences of the radiation than conventional DVHs. Additional work is currently underway to test this hypothesis.

Acute superior vena cava syndrome after central venous catheter placement.

Most cases of superior vena cava (SVC) syndrome are secondary to malignant disease and subacute in their presentation. Acute cases of SVC syndrome have been described, with the majority of these being precipitated by thrombosis after central venous catheterization. The authors report a case of acute SVC syndrome after central venous catheter placement, which was not due to thrombosis, but rather caused by a catheter occluding a previously subclinical stenosis of the SVC. Resolution of the clinical SVC syndrome occurred after catheter withdrawal.

A phorbol ester tolerant (PET) variant of HL-60 promyelocytes.

The promyelocytic leukaemia cell line HL-60 differentiates to a macrophage-like cell when exposed to the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) and other agents which activate protein kinase C. To investigate this phenomenon we developed an HL-60 variant which does not differentiate when exposed to TPA. HL-60 cells were exposed to the mutagen ethyl methanesulphonate and were cloned in soft agar in the presence of a normally lethal concentration of TPA. One colony of cells that proliferated in TPA was obtained. The cells of this phorbol ester tolerant (PET) line have retained their resistance to TPA for several years without selective pressure. They are somewhat larger than their phorbol ester sensitive (S) parent, but they are otherwise morphologically similar. When PET-cells are exposed to TPA their growth is arrested for approximately 48 h. Thereafter, they resume their original rate of replication at all concentrations of TPA tested. S-cells undergo changes typical of HL-60 when exposed to TPA; they aggregate, stop growing, adhere to the flask and die. The PET-cells appeared to be as sensitive as S-cells to other agents which differentiate HL-60 such as retinoic acid, dimethysulphoxide, and 1,25-dihydroxyvitamin D3, as determined by rate of proliferation in culture, Wright's stain, nitroblue tetrazolium reduction, and induction of the ectoenzyme NAD-glycohydrolase. TPA-induced protein phosphorylation was studied using one- and two-dimensional polyacrylamide gel electrophoresis. Several proteins increased their incorporation of 32P when S- and PET-cells were exposed to TPA, the most prominent of which were the two previously described nuclear matrix proteins of 80 kd and 33 kd. There was no difference in the protein phosphorylation pattern in S- and PET-cells, nor in how this pattern changed on TPA exposure. Fluorescent activated cell sorting and karyotypic analysis revealed PET-cells to be a hypotetraploid variant of S-cells, with approximately 80 chromosomes, including a marker chromosome iso(1p) not found in the S-cells. Identification of the biochemical lesion responsible for this TPA resistance in PET cells will provide clues concerning the mechanism of this important pathway for the induction of cell differentiation.