Max L. Baker

Biological Effects of Diagnostic Ultrasound: A Review

Biological effects from experimental ultrasound studies, such as chromosome aberrations and retardation of growth, have been recorded but mostly at levels far in excess of diagnostic intensity. The data surveyed in this review suggest that there is apparently little or no danger associated with diagnostic ultrasound exposure at clinical levels.

Prevention of chronic radiation enteropathy by dietary glutamine

AbstractBackground: Nearly 50% of all cancer patients receive therapeutic radiation during the course of their disease. The risk of late complications is the main dose-limiting factor in the delivery of radiation therapy. The small intestine, the major site of chronic radiation enteropathy, is also the principal organ of glutamine consumption. We therefore hypothesized that the provision of supplemental glutamine may have a protective effect on the development of chronic radiation enteropathy. Methods: This study evaluated the effects of supplemental oral glutamine on the development of chronic radiation (XRT) enteropathy. After scrotalization of a loop of small intestine, rats were randomized to receive 1 g/kg/day glutamine (GLN) or glycine (GLY) by gavage. After 2 days of prefeeding, rats were randomized to 1 of 4 groups: GLN + XRT (n=10), GLY + XRT (n=10), GLN only (n=10), GLY only (n=10). Twenty Gy was delivered to the scrotalized bowel in the GLN + XRT and GLY + XRT groups via a collimated beam. Gavage was continued for 10 days. Animals were then pair-fed chow. Rats were killed at 2 months postirradiation. Chronic radiation injury was assessed microscopically. Results: Injury scores in GLN + XRT were similar to those of unirradiated bowel and significantly different from GLY + XRT (1.89 ± 0.48 in XRT + GLN vs. 6.42 ± 1.55 in the XRT + GLY,p<0.01). Elevated Injury Scores in the XRT + GLY group correlated with gross thickening and fibrosis, a 10-fold decrease in gut GLN extraction (1.40 ± 4.3% in GLY + XRT vs. 16.0 ± 5.1% in GLN + XRT,p<0.05), and a 30% decrease in glutathione content (2.46 ± 0.19 and GLY + XRT vs. 3.17 ± 0.17 GLN + XRT,p<0.05). Conclusions: Provision of GLN during abdominal/pelvic XRT may prevent XRT injury and decrease the long-term complications of radiation enteropathy.

Angioscopically monitored saphenous vein valvulotomy

Angioscopy was used during in situ saphenous vein bypass grafting in seven patients. We were able to visualize valve incision, immediately identify and correct incomplete valvulotomy, identify side branches as potential arteriovenous fistulas, and assess distal anastomotic integrity. We encountered no retained valve cusps after angioscopy, as verified by Doppler ultrasound and completion angiography. Angioscopy verified distal anastomotic integrity in all patients with distal vein grafts large enough to accept the angioscope. Angioscopy requires minimal time, is relatively easy to use, serves as an adjunct to Doppler ultrasound and completion angiography, and has future potential as a therapeutic tool.

Copper-, iron-, manganese- and zinc-3,5-diisopropylsalicylate complexes increase survival of gamma-irradiated mice

Eighty μmol/kg of copper(II)2(3,5-diisopropylsalicylate)4(H2O)2 [Cu(II)2(3,5-DIPS)4] given subcutaneously (sc) to female mice 24 h before lethal (LD10030) irradiation was found to allow 58% survival. Subsequent studies using LD5030 irradiations revealed that 80 or 92% survival was obtained in female or male mice, respectively, when 20 μmol/kg was given 3 h before irradiation; 88–92% survival was achieved in female mice treated with 2.5, 5, or 10 μmol/kg 3 h after irradiation; and 75 or 95% of the male mice survived when they had been given 50 μmol/kg orally 24 or 4 h, respectively, before irradiation. Using LD5030 irradiations it was also found that administration of 280 μmol of Fe(III)-(3,5-DIPS)3(H2O)/kg led to 84% survival in male mice; 80 μmol of Mn(II)-(3,5-DIPS)2(H2O)/kg allowed 96 or 100% survival in male or female mice, respectively; and 60 μmol Zn(II)-(3,5-DIPS)2/kg achieved 95% survival in male mice. In addition, all of these complexes were found to have anti-convulsant activities suggesting possible protection against radiation-induced seizures. It is concluded that these essential metalloelement complexes have radiation-protection and radiation-recovery activities and that their use represents a physiological approach to preventing or perhaps predominantly facilitating recovery from radiation injury.

Copper(II)(3,5‐Diisopropylsalicylate)2 Accelerates Recovery of B and T Cell Reactivity Following Irradiation

Copper(II)(3,5‐diisopropylsalicylate)2 (Cu‐DIPS), administered subcutaneously to mice at 80 mg/kg body weight, bad marked radioprotective activity. Given 3 h before exposure to 8.0 Gy (800 rad) irradiation. Cu‐DIPS increased the 42‐day survival from 40% to 86%. Seven days after exposure to 8.0 Gy, there were severe reductions in spleen weight (73%) and cellularity (98%) in both Cu‐DIPS‐and vehicle‐treated mice. Viable spleen cells collected 7 days after irradiation were totally unresponsive to mitogenic or antigenic stimulation regardless of Cu‐DIPS or vehicle treatment, suggesting that Cu‐DlPS did not prevent radiation‐induced damage to mature lymphocytes. At 14 days, when Cu‐DIPS‐treated mice started to show improved survival over vehicle‐treated mice, spleen weights and cellularity were 2.5‐ and 3.5‐fold higher, respectively, in Cu‐DIPS‐treated mice. Treatment with Cu‐DIPS not only enhanced splenic repopulation. but also accelerated the reappearance of both B and T cell reactivities. Spleen cell responsiveness to the B cell mitogen, lipopolysaccharide (LPS), and the T cell mttogen, concanavalin A (Con A), regenerated significantly faster in Cu‐DIPS‐treated mice. Cu‐DIPS also significantly accelerated the regeneration of T‐dependent antibody induction. Based on these assays of immunocompetence, Cu‐DIPS‐treated mice had, on average, a seven‐fold greater capacity to respond to immune stimulation than vehicle‐treated mice 24 days after irradiation.

Radiation Recovery Agents: Cu(II), Mn(II), Zn(II), OR Fe(III) 3,5-Diisopropylsalicylate Complexes Facilitate Recovery from Ionizing Radiation Induced Radical Mediated Tissue Damage

Pathological consequences of human exposure to increasing doses of ionizing radiation: Hematopoietic, Gastrointestinal, and Central Nervous System syndromes, are rather well understood.1 Bone marrow aplasia and loss of immunocompetency with low (2 to 10 Gray) doses of irradiation, gastrointestinal ulceration and systemic infection with higher radiation doses, and loss of brain function with still higher doses account for the diminishing duration of survival following exposure to increasing doses of ionizing radiation.

THE SENSITIVITY OF TRICHOMONAS VAGINALIS AND TRICHOMONAS GALLINAE TO ULTRAVIOLET RADIATION

Abstract The formation of colonies in solid medium was used as a criterion of viability to determine the effect of ultraviolet radiation on Trichomonas vaginalis. Both viability (colony) counts and total cell (hemocytometer) counts were used to estimate physiological ages of cell populations to be irradiated. Washed‐cell suspensions in 0.6% saline were exposed to far‐ (254 nm) and near‐UV (300–400 nm) radiation and dose‐response survival curves were constructed from colony counts. The effect of far‐UV was found to be independent of growth phase with the D0 for exponential, early stationary, and late stationary cells 2.6, 2.7, and 2.7 J/m2, respectively. Survival to near‐UV increased with the age of cells with the estimated D50 being 216 J/m2 for exponential cells, 1360 J/m2 for early stationary cells, and 4200 J/m2 for late stationary cells. Exponential cells of Trichomonas gallinae irradiated with near‐UV had a D50 of 340 J/m2. T. vaginalis is highly sensitive to far‐UV relative to protozoa. T. vaginalis and T. gallinae are highly sensitive to near‐UV relative to other microorganisms.

Fast neutron and x-ray induced single strand DNA breaks in cultured mammalian cells

The relative biologic effectiveness (RBE) of fast neutrons in the production of single strand DNA breaks is 1.6 as compared to that of 250 kVp x rays. Monolayers of L-929 cells were treated with dinitrophenol during irradiation to prevent the DNA strands from rejoining; the extent of DNA damage was measured by the alkaline sucrose sedimentation method. The RBE for DNA damage is essentially the same as the RBE measured by cell survival methods.

Bioavailable Copper Complexes Offer a Physiologic Approach To Treatment Of Chronic Diseases

Copper (II)2(3,5-Diisopropylsalicylate)4(H2O)2 has been found to have antiinflammatory, antiulcer, anticonvulsant, anticancer, anticarcinogenic, antimutagenic, and radiation recovery activities and it prevents reperfusion injury. To study pharmacokinetic parameters accounting for these pharmacological effects the double labeled 67Cu(II)2(carboxy-14C-3,5-diisopropylsalicylate)4 complex was synthesized and used to obtain these parameters. Treatment of mice with 1 mumol of this complex revealed that 67Cu was distributed to blood, liver, kidney, intestine, lung, thymus, femur, muscle, spleen, brain, urine, and feces within 0.5 hr and patterned changes in 67Cu content of these tissues and excreta were found throughout the 96 hr term of this study.

The effect of ionizing radiation on the viability of Trichomonas vaginalis

1. The effects of continuous gamma radiation on the viability of Trichomonas vaginalis (ATCC 30001) were assessed by a colony count technique. 2. A triphasic survival curve showed an initial shoulder (Dq) of 3 Gy followed by three linear curves with D0 values of 34, 300, and 90 Gy. 3. Sterilization of 10(6) cells/ml occurred from 1600 to 1800 Gy of radiation. 4. Population growth, subsequent to radiation exposure of 17-100 Gy, showed an increased lag time followed by a faster rate of growth, compared with unirradiated cells. 5. Trichomonas vaginalis is more sensitive to ionizing radiation than free-living protozoa and appears as radiosensitive as those parasitic protozoa examined in radioattenuation experiments.