Radiation safety issues with high activities of liquid I-125: techniques and experience.

The handling of a liquid radioactive source is a procedure that is uncommon for the average clinical medical physicist. A newly approved treatment device utilizes high activities of liquid I-125 solution as the source of radiation. The radiation safety issues and our experience utilizing high activity liquid I-125 sources are presented. To date we have treated 22 patients with infused activities ranging up to 26.8 GBq (724 mCi). The careful manipulation of such solutions is important to maintain a safe environment for the patients and the involved medical staff.

Blockade of nuclear factor-kappaB signaling inhibits angiogenesis and tumorigenicity of human ovarian cancer cells by suppressing expression of vascular endothelial growth factor and interleukin 8.

We determined whether blockade of nuclear factor (NF)-kappaB/relA activity in human ovarian cancer cells can suppress angiogenesis and growth in an orthotopic nude mouse model. The human ovarian cancer cells SKOV3ip.1 and HEY-A8 were transfected with a mutated IkappaBalpha (IkappaBalphaM), ie., resistant to phosphorylation and degradation, and hence blocks NF-kappaB activity. NF-kappaB signaling blockade significantly inhibited in vitro and in vivo expression of two major proangiogenic molecules, vascular endothelial growth factor and interleukin 8, in cultured cells and in cells implanted into the peritoneal cavity of nude mice. The decreased expression of vascular endothelial growth factor and interleukin 8 directly correlated with decreased tumorigenicity, decreased vascularization of lesions, decreased formation of malignant ascites, and prolonged survival of mice. These findings suggest that inhibition of NF-kappaB/relA activity in ovarian cancer cells can suppress angiogenesis and progressive growth.

Level of interleukin-8 expression by metastatic human melanoma cells directly correlates with constitutive NF-kappaB activity.

The purpose of this study was to determine whether constitutive NF-kappaB activity regulates the expression level of interleukin-8 (IL-8) in metastatic human melanoma cells. Cultures of metastatic human A375 melanoma cells expressed higher levels of IL-8 mRNA and protein than nonmetastatic A375 human melanoma cells. No discernible differences in IL-8 half-life were found between metastatic and nonmetastatic cells, but cells that overexpressed IL-8 had a higher transcription rate and increased IL-8 promoter activity. Analysis of the IL-8 promoter using deletion mutants revealed that the region within -133 was essential for constitutive IL-8 promoter activity and that mutation of NF-kappaB binding sites eliminated the constitutive IL-8 promoter activity. The activation of constitutive IL-8 transcription directly correlated with the level of constitutive NF-kappaB activity. Transfection of melanoma cells with a dominant-negative mutant IkappaBalpha expression vector (pLXSN-IkappaBalphaM) significantly decreased the level of constitutive NF-kappaB activity and expression of IL-8, demonstrating that constitutive NF-kappaB/relA activities contribute to overexpression of IL-8 in highly metastatic human melanoma cells.

Immunogenicity and efficacy of Russian live attenuated and US inactivated influenza vaccines used alone and in combination in nursing home residents.

The immunogenicity and efficacy of Russian live attenuated and US inactivated trivalent influenza vaccines administered alone or in three different combinations were evaluated in a randomized, placebo-controlled, double-blinded study of 614 elderly or chronically ill nursing home residents in St. Petersburg, Russia during the 1996-97 influenza season. Postvaccination serum antibody responses were more frequent among individuals administered the combination vaccines than among those vaccinated with live or inactivated vaccine alone. Only individuals who received live vaccine, alone or in combination with inactivated vaccine, achieved significant postvaccination increases in virus-specific nasal IgA. Efficacy in preventing laboratory-confirmed influenza in vaccinated versus nonvaccinated individuals was 67% (95%CI, 36-81%) for recipients of a combination of the vaccines compared with 51% (95%CI, -17-79%) for recipients of live vaccine alone and 50% (95%CI, -26-80%) for recipients of inactivated vaccine alone. These results suggest that administration of a combination of influenza vaccines may provide a strategy for improved influenza vaccination of elderly people.

Nuclear factor-kappaB activity correlates with growth, angiogenesis, and metastasis of human melanoma cells in nude mice.

The purpose of this study was to determine the role of nuclear factor (NF)-kappaB/relA activity in the induction of angiogenesis and production of metastasis by human melanoma cells. Highly metastatic melanoma variant cells expressed high levels of constitutive NF-kappaB activity. Transfection of highly metastatic human melanoma variant cells with a dominant-negative mutant inhibitor of nuclear factor-kappaB alpha (Ikappabeta alpha) expression vector (Ikappabeta alphaM) decreased the level of constitutive NF-kappaB activity, inhibited s.c. tumor growth, and prevented lung metastasis in nude mice. Furthermore, the slow-growing s.c. tumors formed by the IkappaB alphaM-transfected cells exhibited a decrease in microvessel density (angiogenesis), which correlated with a decrease in the level of interleukin-8 expression. Collectively, these results demonstrate that NF-kappaB/reLA activity significantly contributes to tumorigenicity, angiogenesis, and metastasis of human melanoma cells implanted in nude mice.

Postimplant analysis of transperineal interstitial permanent prostate brachytherapy: evidence for a learning curve in the first year at a single institution.

PURPOSE: The utilization of transperineal interstitial permanent prostate brachytherapy (TIPPB) is increasing in the United States. Quality assessment of TIPPB is in its infancy, and to date, dosimetric analyses have only been reported from centers with a large experience in prostate brachytherapy. The purpose of this report is to critically analyze the dosimetric coverage achieved following TIPPB in the first 63 cases performed by a multidisciplinary group of investigators with no prior experience with TIPPB. METHODS AND MATERIALS: The information in this report concerns the first 63 men treated with TIPPB alone at our institution between September 1997 and September 1998. All men were treated similarly, adapting the methods described by Blasko and Grimm. All men were treated with 125I. The prescription dose was 144 Gy according to the TG43 formalism. TIPPB was performed jointly by a radiation oncologist and a urologist. One month following TIPPB, all men underwent a computed tomography (CT) scan of the pelvis according to a protocol using 3-mm abutting slices. CT images were transferred by a local area network to a commercially available treatment planning system and dose-volume histograms were calculated with 0.5-mm pixel spacing. A variety of dosimetric endpoints were examined. A single measure of dose homogeneity, the dose-homogeneity index (DHI), is defined as the volume within the prostate that receives 100-150% of the prescription dose (144-216 Gy) divided by the volume within the prostate that receives 100% of the prescription dose (144 Gy). Three measures of target (prostate) dosimetric coverage are provided. C100 is defined as the percentage of the prostate volume defined on postimplant CT that receives at least 100% of the prescription dose. C90 and C80 are similar but represent the percentage of the prostate volume that receive 90% and 80% of the prescription dose, respectively. Statistical analyses were performed using commercially available computer software. To investigate any changes with time the first 30 cases (group 1) are compared to cases 31-63 (group 2). All p-values are two-sided. RESULTS: The mean C100, C90, and C80 for all 63 patients were 80.7% (SD 10.1), 85.1% (SD 10.2), and 89.3% (SD 9.5). The quantifiers of implant adequacy were all improved in the most recent 33 patients compared to the first 30 patients, (group 1: C100, 75.8% [SD 12.2], C90 79.9% [SD 11.4], C80 84.3% [SD 11.1]; group 2: C100, 85.2 [SD 7.0], C90 89.9% [SD 5.8], C80 93.8% [SD 4.2]; p<0.001). The mean DHI was 0.538 SD (0.124). A multivariate model incorporating a number of variables (ultrasound volume, CT volume, total activity, activity/ seed, implant number) with C100 as the dependent variable found that the implant number was the only statistically significant predictor of C100 (p = 0.0001). Using C90 and C80 as the dependent variable produced similar results (C90, p = 0.0001; C80, p = 0.0001). CONCLUSION: In this single institution experience with the first 63 men receiving TIPPB by a multidisciplinary group of investigators, there is evidence for a learning curve. All quantifiers of implant adequacy improved as clinicians gained experience. In the most recent group of patients, quantifiers of implant adequacy are similar to those reported from other groups with significantly more experience with TIPPB.

Early quality of life assessment in men treated with permanent source interstitial brachytherapy for clinically localized prostate cancer.

PURPOSE: We prospectively assessed quality of life changes with time using validated instruments in men with clinically localized prostate cancer treated with permanent source interstitial brachytherapy. MATERIALS AND METHODS: A total of 46 men consecutively treated with permanent source interstitial brachytherapy between September 1997 and June 1998 completed quality of life (Functional Assessment of Cancer Therapy-Prostate [FACT-P]) and urinary symptom (International Prostate Symptom Score [I-PSS]) questionnaires before (T0), and 1 (T1) and 3 (T3) months after treatment. All participants were treated with 125iodine alone. Repeated measures analyses of variance were conducted on all quality of life and urinary outcome measures for 44 patients with data at all 3 time points. RESULTS: Median patient age was 68 years (range 51 to 80). All men had clinical T1c to T2b prostate cancer, Gleason score was 6 or less in 36 (78%) and median pretreatment prostate specific antigen was 7 ng./ml. (range 1.1 to 20.6). Mean score (and standard deviation) at T0, T1 and T3 for each questionnaire was FACT-P 138.9 (14.4), 128.6 (19.4) and 136.7 (17.4), TO versus T1 p = 0.0005 and T0 versus T3 p = 0.6612, and I-PSS 8.3 (5.4), 19.7 (9.0) and 15.7 (7.2), T0 versus T1 p = 0.0001 and T0 versus T3 p = 0.0001. For the global test across time statistically significant differences were observed for the cumulative scores of FACT-P, I-PSS, physical well-being and prostate cancer subscales of the FACT-P and the Trial Outcome Index. By 3 months all quality of life measures had returned to baseline. Urinary symptoms as measured by I-PSS persisted for at least 3 months. CONCLUSIONS: Clinically meaningful decreases in quality of life, as measured by the FACT-P instrument, were evident within weeks after permanent source interstitial brachytherapy. However, by 3 months FACT-P scores returned to near baseline levels. A validated instrument designed to measure urinary symptoms (I-PSS) demonstrated that moderate to severe urinary symptoms persisted for at least 3 months following permanent source interstitial brachytherapy. An instrument specifically designed to measure urinary symptoms can provide additional clinical information when combined with FACT-P.

Renal type I inositol 1,4,5-trisphosphate receptor is reduced in streptozotocin-induced diabetic rats and mice.

The mechanisms underlying glomerular hypertrophy and hyperfiltration in diabetes remain unclear. We have previously demonstrated that the cytokine transforming growth factor-beta1 (TGF-beta1) is increased in early diabetic kidney disease and TGF-beta1 inhibits the expression of the inositol 1,4,5-trisphosphate (IP3)-gated calcium channel, the type I IP3 receptor (IP3R), in mesangial cells. To test the hypothesis that reduced type I IP3R may be important in diabetic kidney disease, we evaluated type I IP3R expression in the kidney of streptozotocin-induced diabetic rats and mice. Two-week-old diabetic rats have decreased renal type I IP3R protein and mRNA levels. Immunostaining of normal rat kidney demonstrated presence of type I IP3R in glomerular and vascular smooth muscle cells, whereas diabetic rats had reduced staining in both compartments. Reduction of type I IP3R also occurred in parallel with renal hypertrophy, increased creatinine clearance, and increased renal TGF-beta1 expression in the diabetic rats. Two-week-old diabetic mice also had reduced renal type I IP3R protein and mRNA expression in association with renal hypertrophy and increased TGF-beta1 mRNA expression. These findings demonstrate that there is reduced type I IP3R in glomerular and vascular smooth muscle cells in the diabetic kidney, which may contribute to the altered renal vasoregulation and renal hypertrophy of diabetes.

Cell density-dependent regulation of mdr-1 gene expression in murine colon cancer cells.

We studied the regulation of mdr-1 and P-glycoprotein in sparse and confluent cultures of murine CT-26 colon carcinoma cells. The expression level of mdr-1 mRNA transcripts (analyzed by Northern blot and in situ hybridization) and P-glycoprotein (analyzed by flow cytometry) inversely correlated with cell density. The modulation of mdr gene expression in sparse and confluent cells was not related to cell division, nutrient depletion, inhibition of protein synthesis, gap junction status, extracellular ATP, or the presence of various extracellular matrixes, but may be related to cell-density and cell-contact mediated changes in phosphatase activity. The confluence-mediated downmodulation of mdr-1 increased the chemosensitivity of the cells to several anticancer drugs commonly associated with an in vitro MDR phenotype by increasing the intracellular accumulation of the drugs. These data may explain some of the discrepancies in results obtained when analyzing mdr gene expression in tumors growing in vivo or in vitro, and why mdi expression in tumors is localized to the periphery of the lesions.

Dose-response curves for Fricke-infused agarose gels as obtained by nuclear magnetic resonance.

The radiation-response characteristics of agarose gels prepared with Fricke dosemeter solution have been studied. The response mechanism is an increase in the NMR longitudinal relaxation rate of protons caused by ferric ions. It has been observed that: (i) oxygen saturation assures consistent and maximum sensitivity; (ii) agarose concentrations in the range 1.0-2.0% have no effect upon sensitivity; (iii) the initial G value is 150 Fe3+/100 eV for gels containing 0.5 mM Fe2+ ions; (iv) increasing NMR frequencies only causes a moderate increase in sensitivity; (v) the gel dosemeters are dose rate independent in the range 4.7-24.2 Gy min-1; (vi) sensitivity is pH dependent, being zero at pH 7; (vii) freshly prepared gels are slightly more sensitive than those more than 24 h old; and (ix) the diffusion coefficient for ferric ions in a 1.0% agarose gel containing 0.0125 M H2SO4 is 1.83 x 10(-2) cm2 h-1, and this will require consideration for the NMR imaging of dose distributions.

Effect of albumin and free calcium concentrations on calcium binding in vitro.

In vivo equilibrium dialysis studies were performed to define further the characteristics of calcium binding to bovine albumin. The concentration range for albumin (1 to 9 g/dl) as well as ultrafilterable calcium (0.5 to 2.5 mM) studied encompassed those that might be ordinarily encountered in most clinical situations. Major differences in the regressions of total calcium on ultrafilterable calcium occurred at albumin concentrations of 1, 2, and 9 g/dl but only small differences at albumin concentrations between 3, 5 and 7 g/dl. When albumin concentration was kept constant, the amount of calcium bound to albumin varied directly with ultrafilterable calcium. At any constant ultrafilterable calcium concentration albumin bound calcium varied inversely with the albumin concentrations when albumin was greater than 3 g/dl. Analysis of the data to determine association constants and molar calcium to albumin binding ratios showed that both parameters were dependent on the absolute albumin concentrations. Our results indicate that calcium binding to albumin is a complex process characterised by multiple binding sites whose affinity and binding capacity are variable. These properties suggest that correction of total serum calcium using clinical formulations with fixed calcium to albumin binding ratios may be inappropriate, particularly in hypoalbuminaemic states.

Effect of erythrocytes and globulin on renal functions of the isolated rat kidney.

We assessed the effects in isolated perfused rat kidneys of adding globulin or erythrocytes to Krebs-Henseleit bicarbonate perfusate with albumin as its principal source of colloid osmotic pressure during 3 h of perfusion. Colloid osmotic pressure varied between 11 and 58 mmHg. Bovine or human immunoglobulin substituted in part for albumin produced vasodilation, whereas rat erythrocytes added to albumin at a 5% hematocrit caused vasoconstriction. Inclusion of both globulin and erythrocytes in the perfusate was associated with an intermediate response. Kidneys perfused with albumin alone showed progressive decline in GFR, increasing vascular resistance, and increasing proteinuria correlating with kidney weight gain during perfusion. Onset of GFR and resistance changes were delayed and their magnitude decreased by increasing oncotic pressure. Estimated glomerular filtrate protein concentration of albumin-perfused kidneys progressively increased from 20 to 150 mg/dl. The presence of erythrocytes or globulin in the perfusate prevented the increase in vascular resistance and reduced the degree of decrease in GFR seen with albumin alone in the perfusate and reduced the time-dependent increase in proteinuria by 80%. The effects of globulin and erythrocytes on proteinuria were additive. The prevention of changes in hemodynamics, glomerular filtration, macromolecular clearance, subcapsular fluid accumulation, and organ weight gain for up to 5 h of perfusion by adding erythrocytes and globulins to the albumin perfusate suggest that these agents may be necessary for preventing interstitial edema and for maintaining renal function in vitro.

Extracellular fluid of the kidney preserved by the Collins technique.

Hilar drainage fluid of dog kidneys was analyzed as an approximation to renal extracellular fluid after preservation by flushing with chilled high K-low Na solution (Collins C4) followed by ice-cold storage for 24 and 48 hr in a bath of flushing medium. Compared with the medium, Na and Cl were increased to 30 mM/liter and K decreased slightly to 93 mM/liter. Glucose decreased, whereas lactate, lactic dehydrogenase, and creatine phosphokinase increased by significant amounts in both the drainage fluid and bath. The inulin space of the undrained kidney average 37% of wet weight. Calculated intracellular Na and Cl concentrations averaged 50 and 37 mM/kg cell water while K remained within normal limits. A significant fraction of red blood cells retained during initial flushing entered the effluent during storage. Bath and effluent composition of a human cadaver kidney approximated those of a dog.

The nature of the phosphorus linkage in component I, a phosphoprotein isolated from the blood serum of DES-treated cockerels.

The nature of the phosphorus linkage in electrophoretic component I of the blood serum of DES-treated cockerels was investigated by enzymatic and partial acid and alkali dephosphorylation. The C-P bond was excluded because this bond is stable to 6 N HCl at 110 degrees C. for 20 hours, and all the phosphorus was released under these conditions. No phosphorus was released when diesterase, pyrophosphatase and 0.25 N HCl were employed, and this excludes the diester, pyrophosphate and N-P bonds. The presence of the O-P bond was supported by the release of phosphate by the phosphatases and 0.25 N NaOH. The hydrolysate produced upon hydrolysis with pronase and papain contained phosphoserine. No phosphothreonine was present.

Studies on variants of Bacillus stearothermophilus strain NCA 1518.

The heat resistance, fermentation reactions, nutritional requirements, and phage sensitivity of 18 selected morphological variants of Bacillus stearothermophilus NCA 1518 were studied. It was found that when smooth variants mutated to rough colonial morphology, there was no concurrent change in fermentation reactions, nutritional requirements, or heat resistance. The smooth variant, and the rough mutants derived directly from it, presented a uniform pattern of biochemical capabilities which differed from the pattern presented by the rough variants isolated from the same stock culture. This led to the conclusion that the smooth and rough types previously observed in stocks of B. stearothermophilus NCA 1518 either were carried in the stock since the original isolation or represent a very profound and uncommon mutation, or that one of the variants has been introduced into the stock culture from an extraneous source sometime in the past.