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By comparison of the cesium-137 and potassium contents in the components of smoked and nonsmoked cigarettes of the same kind, the transfer rate in the mainstream smoke and in the sidestream smoke was found, to be appreciably smaller than 1%.
42 to 75 pCi cesium-137 and 702 to 903 pCi strontium-90 per kg were found in samples of tobacco of German origin and from commercial cigarette. The presence of these radionuclides in tobacco is attributed to the fallout from nuclear explosions. Taking into consideration mean transfer rates of the radionuclides in the main stream smoke condensate and average consumption of cigarettes, whole body radiation doses for inhalation have been calculated to be in the range 10(-3) to 10(-4) mrem/year and per person. This means, they are in the same order of magnitude as radiation doses by inhalation of ambient air. They are smaller by a factor of 10(-4) than the radiation exposure due to ingestion of these radionuclides from the total diet.
As part of a study on the ingestion and organ content of some trace elements of importance in radiological protection, additional work has been undertaken to acquire improved reference values for cesium, iodine, strontium, thorium, and uranium in four selected reference materials provided by the US National Institute of Standards and Technology. The materials are SRM-1548 Total Diet, SRM-1548a Typical Diet, SRM-1486 Bone Meal, and RM-8414 Bovine Muscle. A coordinated study was undertaken with the help of seven selected laboratories in five countries. Instrumental and radiochemical neutron activation analysis and inductively coupled plasma-mass spectrometry were the analytical main techniques used.
The interaction between cesium chloride CsCl and calcium chloride CaCl2 was observed in bone marrow chromosomes of mice. The two salts were administered orally to laboratory bred Swiss albino mice in vivo singly or one followed by the other, or both simultaneously. CsCl induced chromosomal aberrations in frequencies directly proportional to the dose administered. The frequency of aberrations was reduced significantly when the two chemicals were administered simultaneously or when CaCl2 was given 2 h before CsCl. Thus, CaCl2 is able to protect against the cytotoxicity of CsCl.
The two most frequently performed diagnostic X-ray examinations are those of the extremities and of the chest. Thus, dose reduction in the field of conventional skeletal and chest radiography is an important issue and there is a need to reduce man-made ionizing radiation. The large-area flat-panel detector based on amorphous silicon and thallium-doped cesium iodide provides a significant reduction of radiation dose in skeletal and chest radiography compared with traditional imaging systems. This article describes the technical background and basic image quality parameters of this 43 x 43-cm digital system, and summarizes the available literature (years 2000-2003) concerning dose reduction in experimental and clinical studies. Due to its high detective quantum efficiency and dynamic range compared with traditional screen-film systems, a dose reduction of up to 50% is possible without loss of image quality.
The purpose of the study was to evaluate observer performance in the detection of pneumothorax with cesium iodide and amorphous silicon flat-panel detector radiography (CsI/a-Si FDR) presented as 1K and 3K soft-copy images. Forty patients with and 40 patients without pneumothorax diagnosed on previous and subsequent digital storage phosphor radiography (SPR, gold standard) had follow-up chest radiographs with CsI/a-Si FDR. Four observers confirmed or excluded the diagnosis of pneumothorax according to a five-point scale first on the 1K soft-copy image and then with help of 3K zoom function (1K monitor). Receiver operating characteristic (ROC) analysis was performed for each modality (1K and 3K). The area under the curve (AUC) values for each observer were 0.7815, 0.7779, 0.7946 and 0.7066 with 1K-matrix soft copies and 0.8123, 0.7997, 0.8078 and 0.7522 with 3K zoom. Overall detection of pneumothorax was better with 3K zoom. Differences between the two display methods were not statistically significant in 3 of 4 observers (p-values between 0.13 and 0.44; observer 4: p = 0.02). The detection of pneumothorax with 3K zoom is better than with 1K soft copy but not at a statistically significant level. Differences between both display methods may be subtle. Still, our results indicate that 3K zoom should be employed in clinical practice.
Magnesium chloride has been shown to terminate torsades de pointes in some patients with the acquired long QT syndrome. The mechanism for this effect is unknown. Recently early afterdepolarizations (EADs) and triggered activity (TA) have been proposed as causes of torsades de pointes. The purpose of the present study was to examine whether magnesium suppressed EADs that were initiated in vitro by different agents and if so its mechanism of action. TA arising from EADs was induced by quinidine (1 to 4 mumol/L, n = 5) at high temperature (38.5 to 40 degrees C), cesium chloride (5 to 12 mmol/L, n = 6), and 4-aminopyridine (1.5 to 5 mmol/L, n = 7) in canine cardiac Purkinje fibers superfused with modified Tyrode's solution (KCI = 2.7 mmol/L). MgCl2 (2 to 7 mmol/L) reversibly abolished TA and suppressed EADs. Tetrodotoxin (TTX; 1 to 5 mumol/L) also abolished TA elicited by 4-aminopyridine (n = 6). We then examined the effects of MgCl2, TTX, and verapamil on depolarization-induced automaticity by means of a single sucrose gap technique to gain insight into the mechanism of action of magnesium. MgCl2 (5 mmol/L) abolished automaticity arising from membrane potentials more negative than -70 mV and prolonged the spontaneous cycle length at less negative membrane potentials. The effects of TTX (1 to 5 mumol/L) resembled those of MgCl2. Verapamil (1 mumol/L) prolonged the cycle length of the initial automatic response at high levels of membrane potential and progressively reduced the amplitude of the subsequent automatic potentials. It abolished automaticity arising from less negative membrane potentials.(ABSTRACT TRUNCATED AT 250 WORDS)
The effects of OPC-88117, a new investigational antiarrhythmic drug, on early and delayed afterdepolarizations (EAD and DAD, respectively) were assessed in vitro in canine Purkinje fibers and in vivo in the canine right ventricle. OPC-88117 had similar electrophysiologic properties to class I antiarrhythmic agents in that it decreased Vmax. OPC-88117 decreased the amplitude and prolonged the coupling interval of DAD induced by acetylstrophanthidin. Likewise, OPC-88117 suppressed EAD induced in vitro by 4-aminopyridine. In vivo, cesium-induced EAD, ventricular arrhythmia, and atrioventricular block were suppressed by OPC-88117. In summary, OPC-88117 suppressed DAD and EAD in vitro and inhibited EAD and triggered activity in the in situ canine heart.
A procedure for the simultaneous banding of cellular DNA, RNA, and protein by centrifugation in cesium trifluoroacetate (CsTFA) gradients is described. Starting with homogenates of Day 11 rat embryos, this procedure was used to separate total DNA, RNA, and protein. Under the conditions used DNA banded at a peak density of 1.63 g/ml, RNA at a peak density of 1.83 g/ml, and protein at a peak density of 1.40 g/ml. Nucleic acids isolated from CsTFA gradients were judged to be protein free. RNA isolated by this method is apparently free of DNA contamination; however, DNA isolated by this method does contain some RNA (less than 5% contamination).
100 human pineal bodies (56 male and 44 females) were analyzed by means of instrumental neutron activation analysis for trace concentrations of cobalt, iron, rubidium, selenium, zinc, antimony and cesium. The results indicated that the measured element concentrations are not related to body-surface, age and fresh weight. Moreover, the mean absolute cobalt value from 97 pineal bodies is increased by a factor of 1.43 over the mean absolute concentration value of 257 other areas of the brain. The mean zinc content is found to be 3.7 fold higher than the mean zinc value from 269 other samples of brain. The iron values from various brain areas do not differ from those of the pineal body. Compared to other brain regions pineal selenium is increased and rubidium is decreased. Correlating the different element concentrations to each other, a positive correlation is found for selenium and ribidium, a negative correlation for cobalt and zinc. The present data suggest that the measured trace elements are somehow related to specific roles in the physiology and biochemistry of the pineal body. This is supported by the constancy of element concentration over a wide range of increasing fresh weights of the organ. It is considered that zinc, cobalt and iron are involved as constituents of enzymes in the metabolism of amino acids, peptides and proteins of the pineal body. Moreover the conspicuous high zinc content of this organ may be related to a so far undetected neurotransmitter.
From September 1972 to September 1987, thirty-six patients with stage II carcinoma of the endometrium were treated with external-beam radiotherapy to the pelvis, a single intracavitary application of cesium-137, and extrafascial hysterectomy with adnexectomy. Patients were followed for a median of 54.4 months. Overall 2- and 5-year actuarial survival rates were 83 and 58%, respectively. Survival was analyzed in terms of the independent variables surgical stage, presence of a gross cervical lesion, and residual disease within the myometrium or cervix. Factors contributing to patients survival were analyzed by the log-rank method. The 12 patients with a gross cervical lesion had an adverse prognosis, as compared to those without such a lesion (P less than 0.05). Seven of the twelve patients (58%) with a cervical lesion at clinical staging demonstrated persistent or recurrent disease. The presence of extrauterine disease at surgery was a major prognostic factor in patient survival (P less than 0.01). All six patients with extrauterine disease expired 2.3 to 53.0 months after hysterectomy. Two patients with persistence of disease expired 2.3 and 7.5 months after hysterectomy. Eleven patients developed recurrent disease 2.1 to 56.5 months after hysterectomy. All presented with distant metastases. Four of the thirteen patients with persistent or recurrent disease had no residual tumor within the myometrium.
The effect of cesium therapy on various cancers is reported. A total of 50 patients were treated over a 3 year period with CsCl. The majority of the patients have been unresponsive to previous maximal modalities of cancer treatment and were considered terminal cases. The Cs-treatment consisted of CsCl in addition to some vitamins, minerals, chelating agents and salts of selenium, potassium and magnesium. In addition, a special diet was also instituted. There was an impressive 50% recovery of various cancers, i.e., cancer of unknown primary, breast, colon, prostate, pancrease, lung, liver, lymphoma, ewing sarcoma of the pelvis and adeno-cancer of the gallbladder, by the Cs-therapy employed. There was a 26% and 24% death within the initial 2 weeks and 12 months of treatment, respectively. A consistent finding in these patients was the disappearance of pain within the initial 3 days of Cs-treatment. The small number of autopsies made showed the absence of cancer cells in most cases and the clinical impression indicates a remarkably successful outcome of treatment.
Predetermined amounts of cesium chloride or carbonate, zinc gluconate and vitamin A were used together to alter growth of colon carcinoma (C38) implants in BDF1 mice. Data show that the use of these compounds in a treatment protocol is responsible for repression of tumor growth.
Proteoglycans were extracted from 14-day chick embryo brains, which had been labelled in vitro with [35S]sulfate or 3H-labelled amino acids. 4.0 M guanidinium chloride (containing proteinase inhibitors) extracted 94% of the 35S-labelled glycoconjugates. Following cesium chloride equilibrium centrifugation, the proteoglycans in each fraction were characterized by chromatography on Sepharose CL-2B. The most dense fraction (D1), which contained no detectable non-proteoglycan proteins, contained a large, aggregating chondroitin sulfate proteoglycan in addition to small chondroitin sulfate and heparan sulfate proteoglycans. The less dense fractions (D2-D6) contained both small chondroitin sulfate and heparan sulfate proteoglycans. Removal of hyaluronate from the D1 sample by digestion with Streptomyces hyaluronidase in the presence of proteinase inhibitors showed that aggregation of the large chondroitin sulfate proteoglycan is hyaluronate-dependent. Aggregation was restored by re-addition of hyaluronate. Reduction and alkylation, which blocked aggregation of a cartilage A1 proteoglycan, did not interfere with aggregation of the large brain proteoglycan.
One hundred thirty previously untreated patients with invasive squamous cell carcinoma of the oral tongue received interstitial radiotherapy with curative intent using cesium needles. Ninety-nine patients were treated with interstitial radiotherapy alone and 31 patients received interstitial radiotherapy combined with external beam irradiation. The recurrence-free rates in the primary lesions were 94.4% (17/18) in T1, 91.2% (52/57) in T2, and 70.9% (22/31) in T3 lesions. The local recurrence-free rates with single-plane and two-plane implantation were good: 89.7% (70/78) and 85.7% (12/14), respectively. The rate of 64.2% (9/14) for volume implantation was significantly poorer (p < 0.05). It is evident that tumor volume is an important factor in the control of cancer following interstitial therapy. The overall incidence of ulceration of the tongue and mandibular complication was 20% (26/130) and 13% (17/130), respectively. Using both interstitial and external radiotherapy, the incidence was 22.5%, compared with 10.1% using interstitial radiotherapy alone. The mandibular complication incidence of 8.9% with single-plane implants was much lower than 20.8% for two-plane and 23.5% for volume implants. Interstitial radiotherapy is most suitable in T1 and T2 cases in which single-plane implantation is possible; for these patients interstitial radiotherapy, which has the advantage of preserving the structure and function of the tongue, should continue to be used in the future in spite of the progress in reconstructive surgery.
The antagonistic effect of chlorophyllin was tested in reducing the clastogenic action of cesium chloride (CsCl) in vivo on mice bone marrow cells. CsCl induced chromosomal aberration in frequencies directly proportional to the dose administered. Chlorophyllin, when given alone, was not clastogenic even at a concentration of 1.5 mg/kg body wt. of the animal. Simultaneous administration of chlorophyllin and CsCl reduced chromosomal aberrations significantly at 24 h. Exposure to the same dose of chlorophyllin 2 h before exposure to CsCl also decreased clastogenic effects but to a lesser extent. These findings are of importance in view of the uptake of radioactive Cs by green plants after nuclear fallout.
A rapid and efficient procedure for purifying bacteriophage lambda DNA is described. This small-scale purification involves isolation of bacteriophage particles on cesium chloride gradients. Using an Airfuge ultracentrifuge, the centrifugation step can be readily achieved in 90 minutes. The method allows a 1-day purification of up to 12 independent lambda DNA (20-40 micrograms each). The recovered DNA, essentially devoid of RNA and DNA contaminants, is efficiently cut by restriction endonucleases and can serve as starting material for the ligation of DNA fragments in other cloning vehicles.
Isotopic ratio measurements of 135Cs to 137Cs were performed using both resonance ionization mass spectrometry (RIMS) and thermal ionization mass spectrometry (TIMS) to determine the chronological age of nuclear fuel burn-up samples. Initial measurements on a lake sediment sample are being performed at NIST for determination of cesium content in the sample. Atomization behavior of the graphite furnace source, the overall efficiency and selectivity were measured for different sample preparations. Single-resonance excitation 6s 2S1/2 (F=4) --> 6p 2P3/2 (F' = 5) with an extended cavity diode laser followed by photoionization with the 488nm line of an argon ion laser yielded optical selectivity for 135Cs and 137Cs of more than two orders of magnitude against stable 133Cs and overall selectivity of 10(8). An overall efficiency of 5 x 10(-7) was measured for standard 133Cs solutions and for the nuclear fuel burn-up samples.