Lead as surface bolus for high-energy photon and electron therapy.

Dose distributions were evaluated under thin sheet lead used as surface bolus for 4- and 10-MV photons and 6- and 9-MeV electrons using a parallel-plate ion chamber and film. A narrow, significantly low dose region (-17%) was noted for 4-MV photons, whereas a 6% increase in dose was present for 10-MV photons. The dose was elevated 15%-22% near the surface of electron fields with lead bolus, but depth dose relationships were similar to soft-tissue-equivalent (STE) bolus.

Detection of a subunit of cellular Pol II within highly purified preparations of RNA polymerase isolated from rabbit poxvirus virions.

A large (approximately 200 kd) subunit of cellular RNA polymerase II (Pol II) and a virus-encoded subunit of rabbit poxvirus (RPV) RNA polymerase (137 kd) react with common monoclonal antibodies. Hybridization studies with viral and cellular DNA clones confirm that the viral and cellular proteins are related. Following RPV infection, the Pol II subunit is translocated from the nucleus to the cytoplasmic virosomes, then packaged into mature virus, and is found associated with the viral RNA polymerase purified from virions.

Isolation and characterization of monoclonal antibodies directed against two subunits of rabbit poxvirus-associated, DNA-directed RNA polymerase.

A library of monoclonal antibodies directed against individual proteins of the rabbit poxvirus (RPV) virion within a complex immunogenic mixture has been generated through the use of in vivo and in vitro immunization regimens. The relative efficacies of the two procedures were compared. Based on immunoblot analysis, the in vitro immunization regimen led both to a wider variety of monoclonal antibodies to different proteins and to a larger number of antibodies directed against proteins of higher molecular weights.

Intracellular location of rabbit poxvirus nucleic acid within infected cells as determined by in situ hybridization.

The intracellular location of rabbit poxvirus DNA within cells during the course of infection has been determined by the hybridization in situ of labeled viral DNA probes to uninfected and infected cells under various conditions. Extensive control experiments were performed to demonstrate that DNA could be detected selectively and accurately within the cell. Our results suggest that rabbit poxvirus DNA is located only within the cytoplasm during the reproductive cycle, and we found no evidence that viral DNA enters the cell nucleus.

Tumor growth rate varies with age in lethargic mutant BALB/cGnDu mice.

BALB/cGnDu lethargic mutant mice suffer from an age-related temporary defect in their cell-mediated immune response which is "spontaneously" corrected in animals 7 weeks of age or older. Thus, mutants of different ages (3 to 4 weeks old and 7 to 9 weeks old) were used to compare tumor incidence, tumor growth rate, and host survival time of Harding-Passey (HP) melanoma, mKSA, and GI110(BK)B6D2Tu tumors. Normal littermates were used as controls.

Giant synovial cysts.

Giant synovial cysts (GSC) are large, well-defined cavities, containing synovial fluid and lined by a synovium-like membrane, which extend for a variable distance outside the joint cavity. We are reporting 15 cases of GSC of various joints. Rheumatoid arthritis is the most common disease process reported in association with GSC.

The inability of in vitro transforming SV40 subgenomes to cause tumors in vivo.

Linear or subgenomic SV40 DNAs were transfected into cells from a variety of species (including rodent, dog, muntjak, and monkey) and injected subcutaneously into neonate Syrian hamsters for tumorigenicity testing. The 'early-region' subgenomes were capable of transforming cells in vitro. Complete genomes or complementary subgenomes could transform nonpermissive and semipermissive cells, were infectious for permissive cells, and induced tumors from which infectious virus could be rescued.

A simple method for the preparation of extracts from animal cells which catalyze efficient in vitro protein synthesis.

A rapid, simple procedure is described for the preparation of cell-free extracts of both uninfected and virus-infected pig kidney and baby hamster kidney cells which are very active in the in vitro translation of not only endogenous mRNA, but also of exogenous mRNA added to extracts that had been depleted of endogenous mRNA by treatment with micrococcal nuclease. This procedure appears to be adaptable with only minor variations to many eukaryotic cell lines and should greatly facilitate in vitro molecular studies of protein synthesis and gene regulation at the level of translation.

A double-blind study of trimazosin and methyldopa in hypertensive patients receiving polythiazide.

Data are presented on 22 hypertensive patients in an 18-week, double-blind comparison of trimazosin and methyldopa during which treatment with polythiazide was continued. Maximum daily doses of trimazosin and methyldopa were 800 and 2000 mg, respectively. Eight of nine patients receiving trimazosin and 8 of 12 receiving methyldopa had excellent or good overall responses.

The white pock mutants of rabbit poxvirus: V. In vitro translation of early host range mutant mRNA.

The abortive infections of pig kidney (PK) cells by both RP mu hr23 and RP mu hr31, two early (DNA minus) white pock (mu) host range (hr) mutants of rabbit poxvirus (RPV), are characterized by the in vivo inhibition of both host and viral protein synthesis by 10 hr postinfection although viral RNA synthesis continues. Further analysis reveals that large quantities of functional viral mRNA can be isolated from PK cells abortively infected with RP mu hr23 and translated in vitro throughout the 10-hr period of infection, even though these mRNAs are almost totally inactive in vivo. The in vitro translation of accumulated mRNA isolated from PK cells abortively infected by RP mu hr31 shows a quite different pattern where the maximum amount of RNA translatable in vitro is found at 6 hr postinfection with lesser amounts at 10 hr postinfection.

A surface bolus material for high-energy photon and electron therapy.

The authors describe a useful bolus material for therapy with high-energy photons and electrons (greater than 1 MeV). Qualities evaluated included flexibility, transparency, tissue equivalence (re radiation interactions), stability at high doses, durability, lack of toxicity, ease in cleaning, low flammability, and cost. Using a parallel-plate ionization chamber and 60Co, 4-, and 10-MV photons as well as 6- and 18-MeV electrons, maximum deviation from water-equivalent values was approximately 2 mm for 6-MeV electrons.

A survey of intracellular Na+ and K+ of various normal, transformed, and tumor cells.

Intracellular concentrations of Na+ and K+ of various normal, transformed, and tumor cell cultures were analyzed by atomic absorption spectrophotometry. In all of the cultures analyzed there were markedly different concentrations in the transformed and tumor cells when compared to their normal counterparts. Although increased Na+ was often observed, there were no definitive correlations between absolute ion concentrations, or Na+:K+ ratios, and cell transformation.

Spherical aberration in on-axis and offset unstable confocal resonators.

An analysis of spherical aberration in on-axis and offset unstable laser resonators is presented. Closed-form analytic expressions of the associated Strehl ratio as a function of cavity dimensions and magnification are derived, and effects of simple phase corrections in the optical system are assumed.

Rescue of SV40 following transfection of TC7 cells with cellular DNAs containing complete and partial SV40 genomes.

Infectious SV40 virions could be rescued from permissive TC7 cells within one to three subcultures following cotransfection with two cellular DNAs, each containing a complementary portion of the SV40 genome. SV40 virions could also be rescued by transfection of TC7 cells with cellular DNAs from a variety of SV40 transformed cells containing complete genome equivalents but not from cells containing subgenomes alone or defective genomes. Infectious virus was not rescued if the transfecting DNA species was treated with DNAase or if the DEAE-dextran pretreatment of the recipient cells was omitted.

Susceptibility of BALB/cGnDu mice to transplantable tumors, in vitro transformed cells, BK and SV40 viruses, and chemical carcinogens.

Various oncogenic agents were employed in tumor susceptibility studies of an inbred subline of BALB/cGn mice, BALB/cGnDu, which carries a mutant gene that results in spontaneous thymic involution in homozygous recessive individuals. Of 18 transplantable tumors, 3 in vitro transformed cell lines, 2 oncogenic papovaviruses and 3 chemical carcinogens evaluated, only the Harding-Passey amelanotic melanoma produced tumors in 100% of the normal adult mice injected. The S180 pleomorphic sarcoma produced tumors in 56% of normal adult mice.

Biophysical Factors in Range-of-Motion Exercise.

In brief: Studies of the physical properties of connective tissue have helped determine improved techniques for therapeutic range-of-motion exercise. Laboratory studies indicate that the best way to permanently lengthen connective tissue structures without compromising their structural integrity is prolonged, low-intensity stretching at elevated tissue temperatures and cooling the tissue before releasing the tension. This article provides some practical therapeutic guidelines for physicians, trainers, and therapists who prescribe range-of-motion exercise for both rehabilitation and physical conditioning.

The mechanism of cytoplasmic orthopoxvirus DNA replication.

Orthopoxvirus DNA replication occurs in the cytoplasm of infected cells within discrete foci designated as virosomes. We show that newly synthesized rabbit poxvirus (RPV) virosomal DNA consists predominantly of concatamers wherein unit length molecules are joined by fusion of two left (LL) or right (RR) ends, resulting in genomes aligned in alternating head-to-head and tail-to tail mirror image arrays. These concatameric molecules serve as the substrates from which unit length DNA molecules are excised during morphogenesis.

Induced repair of genetic damage in Neurospora.

Repair of genetic damage in Neurospora has been studied using a procedure in which one strain is exposed to a potentially lethal dose of UV before being joined in a heterokaryon with an undamaged strain. We have monitored the ability of the second strain to rescue the first. The extent of rescue is greatly enhanced when the rescuing strain has itself received a small, nonlethal dose of UV, thus demonstrating an inducible repair system.

Quality assurance of electron-beam energy using an aluminum wedge.

An aluminum wedge was designed to facilitate evaluation of the constancy of high-energy electron teletherapy beams (6-18 MeV). Ready-packed film was exposed with the wedge on top, and optical density distribution was recorded with a scanning densitometer. Energy-dependent statistics were obtained using the practical-range extrapolation method.

The white pock (mu) mutants of rabbit poxvirus. III. Terminal DNA sequence duplication and transposition in rabbit poxvirus.

The restriction fragment patterns of the DNA of three white pock (mu) nonhost range mutants RPmu mutants) of rabbit poxvirus (RPV) show the presence of net insertions of DNA. Two of the mutants (RPmu21 and RPmu7) contain two molar quantities of 13 X 10(6) and 15 X 10(6) daltons, respectively, of the left-most viral DNA sequences. The extra copy of these sequences was inserted into the right-most region of the viral genome which in both cases had been modified by deletion of 10 X 10(6) daltons of the original extreme right-most DNA sequences.