How can dementia and disability be prevented in older adults: where are we today and where are we going?

Ageing of the population, together with population growth, has brought along an ample increase in the number of older individuals living with dementia and disabilities. Dementia is the main cause of disability in old age, and promoting healthy brain ageing is considered as a key element in diminishing the burden of age-related disabilities. The World Health Organization recently launched the first risk reduction guidelines for cognitive impairment and dementia. According to recent estimates, approximately 40% of dementia cases worldwide could be attributable to 12 modifiable risk factors: low education; midlife hypertension and obesity; diabetes, smoking, excessive alcohol use, physical inactivity, depression, low social contact, hearing loss, traumatic brain injury and air pollution indicating clear prevention potential. Dementia and physical disability are closely linked with shared risk factors and possible shared underlying mechanisms supporting the possibility of integrated preventive interventions. FINGER trial was the first large randomized controlled trial indicating that multidomain lifestyle-based intervention can prevent cognitive and functional decline amongst at-risk older adults from the general population. Within the World-Wide FINGERS network, the multidomain FINGER concept is now tested and adapted worldwide proving evidence and tools for effective and easily implementable preventive strategies. Close collaboration between researchers, policymakers and healthcare practitioners, involvement of older adults and utilization of new technologies to support self-management is needed to facilitate the implementation of the research findings. In this scoping review, we present the current scientific evidence in the field of dementia and disability prevention and discuss future directions in the field.

Self-rated physical fitness and estimated maximal oxygen uptake in relation to all-cause and cause-specific mortality

This study investigated the longitudinal associations of self-rated physical fitness and estimated maximal oxygen uptake (VO2max) with all-cause and cause-specific mortality. A total of 59 741 participants in the Finnish National FINRISK Study Cohort had data on self-rated physical fitness and covariates. A subsample of 4823 participants had estimated VO2max data. Follow-up ranged from 3 to 38 years. Associations of self-rated physical fitness and VO2max with mortality were analyzed using multivariate Cox proportional hazard models. The study showed that poor self-rated physical fitness was related to all-cause mortality (hazard ratio [HR] 1.9; 95% confidence interval [CI] 1.8-2.0) and mortality due to cardiovascular (HR 2.0, 95% CI 1.9-2.2), cerebrovascular (HR 1.9, 95% CI 1.6-2.2) and respiratory diseases (HR 2.1, 95% CI 1.9-2.4), trauma (HR 1.7, 95% CI 1.3-2.0), infections (HR 1.8, 95% CI 1.3-2.7), dementia (HR 1.9, 95% CI 1.6-2.3), and cancer (HR 1.7, 95% CI 1.5-1.9). Coexisting higher age, physical inactivity, male gender, and severe chronic conditions further increased the risk. In men, higher VO2max was associated with a lower risk of lung cancer mortality (HR 0.8, 95% CI 0.7-0.96). Based on the results, self-rated physical fitness reflects a combination of unfavorable biological and lifestyle-related factors, which increase mortality risk. A simple question about perceived physical fitness may reveal at-risk individuals who would benefit from more intensive treatment of chronic conditions and other interventions aiming to promote better fitness and well-being.

Association between mid- to late life physical fitness and dementia: evidence from the CAIDE study

OBJECTIVES

This study investigated the association between perceived physical fitness at midlife, changes in perceived fitness during the three decades from mid- to late life and dementia risk.

DESIGN

Prospective cohort study.

SETTING

Cardiovascular risk factors, ageing and incidence of dementia (CAIDE) study.

SUBJECTS

Subjects were selected from four independent, random samples of population-based cardiovascular surveys and were first examined in 1972, 1977, 1982 or 1987, when they were on average 50 years old. The CAIDE target population included 3559 individuals. A random sample of 2000 individuals still alive in 1997 was drawn for re-examinations (performed in 1998 and 2005-2008) that consisted of cognitive assessments, with 1511 subjects participating in at least one re-examination. Dementia diagnoses were also confirmed from national registers for the entire target population.

MAIN OUTCOME MEASURE

All-cause dementia.

RESULTS

Poor physical fitness at midlife was associated with increased dementia risk in the entire target population [hazard ratio (HR), 1.5; 95% confidence interval (CI), 1.1-2.0]. In participants, odds ratio (OR) was 2.0 (95% CI, 0.9-4.0). This association was significant in apolipoprotein E ε4 allele (APOEε4) noncarriers (OR, 4.3; 95% CI, 1.4-13.3), men (HR, 1.8; 95% CI, 1.1-3.0) and people with chronic conditions (HR, 2.9; 95% CI, 1.3-6.6). A decline in fitness after midlife was also associated with dementia (OR, 3.0; 95% CI, 1.7-5.1), which was significant amongst both men and women and more pronounced in APOEε4 carriers (OR, 4.4; 95% CI, 2.1-9.1).

CONCLUSIONS

Perceived poor physical fitness reflects a combination of biological and lifestyle-related factors that can increase dementia risk. A simple question about perceived physical fitness may reveal at-risk individuals who could benefit from preventive interventions.

Radiation dose estimation in computed tomography examinations using NRPB-SR250 software in aretrospective analysis of a patient population

Computed tomography (CT) imaging contributes to a major part of medical radiation exposure. With regard to patients safety, frequent CT examinations (CTEs) performed on the same patient are of particular concern. Tools for tracking the individual patient radiation exposure history and cumulative dose assessment may become important. Here, the applicability of the NRPB-SR250 software was assessed in a retrospective analysis of radiation doses from CTE made consecutively in male patients. Most of the examinations focused on the abdomen or the whole body. The mean number of CTs per patient was 6.8. Significant cumulative effective doses were observed: 76 (66 %) patients received an effective dose higher than 50 mSv, while the maximum was ∼280 mSv. A more than 3-fold effective dose difference was observed between scanners, depending on the scanning protocols. The NRPB-SR250 software proved to be a robust tool for the assessment of organ doses and the effective radiation dose from CT, while challenges were encountered in finding the precise imaging data in retrospective protocols.

Osteodistraction of a previously irradiated mandible with or without adjunctive hyperbaric oxygenation: an experimental study in rabbits

The purpose of this study was to analyse the effects of irradiation and hyperbaric oxygenation (HBO) on mandibular osteodistraction (OD). Eighteen rabbits were divided into three groups: 1. Irradiation (R), 2. Irradiation+HBO (R-HO), and 3. Control group (C). Animals of groups R and R-HO received in the mandible irradiation 22.4 Gy in four 5.6 Gy fractions (equivalent to 50 Gy/25 fractions). In addition, group R-HO was given HBO at 2.5 ATA for 90 min per day 18 times preoperatively. Unilateral osteotomy was made 1 month after completion of radiotherapy. After a 1 week latency period bone distraction was started at rate of 1 mm per day, continued for 2 weeks, and left to consolidate for 4 weeks. Amount of new bone was measured histomorphometrically from midsagittal sections. Area of new bone was equal in all groups. Bone was more mature and bone spicules better organized in group C than in groups R and R-HO. Cartilaginous cells were found in distracted bone in all groups but larger chondroid islands were evident only in group R. It seems that despite delayed bone formation, OD can be performed after radiotherapy. HBO had a beneficial effect on bone quality of a previously irradiated mandible.

Disturbances in craniofacial morphology in children treated for solid tumors

Because of increased survival rates in childhood cancer, special interest has been focused on the side-effects of the therapy and the quality of life in long-term survivors. Our aim was to investigate craniofacial growth in children who had received different kinds of antineoplastic therapies for solid tumors. A total of 40 children treated in the Turku University Central Hospital were examined and divided into three different groups. Group 1 comprised 18 children treated for intracranial tumors with cranial irradiation (CRI) and chemotherapy (CT) including alkylating agents. Seven children out of 18 in this group received growth hormone (GH) therapy. In Group 2, 11 children with extracranial solid tumors also received multiagent CT including alkylating agents, but no CRI. Group 3 consisted of 11 children treated for Wilm's tumor with CT, which did not include alkylating agents or CRI. A total of 19 linear and four angular variables from the lateral cephalograms of the subjects were measured. Most deviations in craniofacial structures were found in children treated with combined CRI and multiagent CT. All disturbances were seen in the vertical measurements which were reduced when compared to the matched controls. It seems reasonable to assume that impaired growth following combined radio- and chemotherapy, as well as GH treatment, particularly affects cartilage-mediated growth. However, the deviations seen in the present study were fairly minor and did not usually require clinical consideration.

Radiotherapy treatment planning and long-term follow-up with [(11)C]methionine PET in patients with low-grade astrocytoma

PURPOSE

To evaluate the feasibility of [(11)C]-methionine positron emission tomography (MET PET) in radiotherapy (RT) treatment planning and long-term follow-up in patients with low-grade glioma.

PATIENTS

Thirteen patients with low-grade astrocytoma and 1 with anaplastic astrocytoma underwent sequential MET PET and magnetic resonance imaging (MRI) before and 3, 6, 12, and 21-39 months after RT, respectively. Ten patients were studied after initial debulking surgery or biopsy and 4 in the recurrence phase.

METHODS

A total of 58 PET scans were performed. After transmission scanning, a median dose of 425 MBq of MET was injected intravenously and emission data was acquired 20 min after injection for 20 min. The uptake of MET in tumor area was measured as standardized uptake value (SUV) and tumor-to-contralateral brain SUV ratios were generated to assess irradiation effects on tumor metabolism. Functional imaging with PET was compared with concurrent MRI in designing the RT planning volumes and in assessment of response to RT during a median follow-up time of 33 months.

RESULTS

In 12 patients (86%), tumor area was clearly discernible in the baseline PET study. In the remaining 2 patients with a suspected residual tumor in MRI, PET showed only a diffuse uptake of MET interpreted as negative in the original tumor area. In the dose planning of RT, MET PET was helpful in outlining the gross tumor volume in 3 of 11 cases (27%), whereas PET findings either coincided with MRI (46%) or were less distinctive (27%) in other cases. In quantitative evaluation, patients with a low tumor SUV initially had significantly better prognosis than those with a high SUV. Tumor-to-contralateral brain uptake ratios of MET discriminated well patients remaining clinically stable from those who have since relapsed or died of disease.

CONCLUSION

Quantitative MET PET has prognostic value at the time of initial treatment planning of low-grade glioma. Some patients may benefit of RT volume definition with MET PET, which seems to disclose residual tumor better than MRI in selected cases. Stable or decreasing uptake of MET in tumor area after RT during follow-up seems to be a favorable sign.

Adhesion of inactivated probiotic strains to intestinal mucus

It has been suggested that probiotics should be viable in order to elicit beneficial health effects. Inactivation of probiotics has been suggested to interfere with the binding to the mucosa and thereby with the immune modulating activity of probiotics. The effect of different inactivation methods on the mucus adhesion of nine probiotic strains was studied. Inactivation by heat or gamma-irradiation generally decreased the adhesive abilities. However, heat treatment increased the adhesion of Propionibacterium freudenreichii and gamma-irradiation enhanced the adhesion of Lactobacillus casei Shirota. Inactivation by u.v. was not observed to modulate the adhesion of the tested strains and it was concluded to be the most appropriate method for studying non-viable probiotics and preparing control products.

The effect of irradiation on mitotic and apoptotic frequency in head and neck cancer cell lines, the correlation to p53 mutations and clonogenic survival

It was our intention to enlighten the controversy between the mainstream of studies and our previous results showing a correlation between the intrinsic radiosensitivity and the p53 allele status of 20 human head and neck squamous cell carcinoma (HNSCC) cell lines. In our study cell lines carrying a wild-type (WT) p53 allele were significantly more radioresistant than cell lines which lacked a WT gene. We observed nine HNSCC cell lines with known intrinsic radiosensitivity and p53 allele status with time-lapse video microscopy after irradiation with 2 and 3 Gy. We studied the mitotic and apoptotic frequencies and scored the apoptoses as to whether they occurred morphologically in mitosis or in interphase. Irradiation with 2 or 3 Gy did not induce apoptosis in the cell lines studied. As expected the mitotic frequency was reduced by the irradiation. This was statistically significant in the cell lines which were radiosensitive when measured with a clonogenic assay. p53 allele status did not have an independent effect on the cell lines, except that the irradiation favoured the apoptosis in mitosis in the cell lines with WT p53 and the apoptosis in the interphase in the cell lines with a mutated or non-functional p53 gene. We conclude that although the apoptosis is not induced by irradiation with 2 Gy or 3 Gy, the p53 suppressor gene seems to influence the process of apoptosis after irradiation in the cell lines studied.

Genome size variation in Hordeum spontaneum populations

Populations of wild barley, Hordeum spontaneum (C. Koch), originating from 10 ecologically and geographically different sites in Israel, were assessed for genome size. Measurements were obtained by flow cytometry using propidium iodide staining. Genome sizes ranged from 9.35 to 9.81 pg. Variance analysis indicated a significant difference between populations. Genome sizes were positively correlated with mean January temperature. Our results corroborate previous findings of intraspecific variation in genome size from different plant species. The positive correlations between climate and genome size suggest that the latter is adaptive and determined by natural selection.

Carboplatin-paclitaxel- and carboplatin-docetaxel-induced cytotoxic effect in epithelial ovarian carcinoma in vitro

BACKGROUND

The combination of paclitaxel and cisplatin is standard for patients with newly diagnosed epithelial ovarian carcinoma. The role of another taxane, docetaxel, currently is being studied. Due to its milder nonhematologic toxicity carboplatin increasingly is being substituted for cisplatin in taxane-based combinations. The purpose of this study was to compare the combination of carboplatin-paclitaxel with carboplatin-docetaxel in ovarian carcinoma in vitro, and to assess the type of interaction, if any.

METHODS

Sensitivity to carboplatin and the concomitant use of a taxane and carboplatin was studied in 4 ovarian carcinoma cell lines using the 96-well plate clonogenic assay. Chemosensitivity was expressed as the IC50 value (i.e., the drug concentration causing 50% inhibition of clonogenic survival). IC50 values were obtained from dose-response curves after fitting the data to the linear quadratic equation. Synergism was studied by the area under the survival curve ratios (AUC ratios), obtained by numeric integration. The AUC ratio and the surviving fraction (SF) value after the administration of taxane alone were compared using the Student t test for paired data.

RESULTS

The IC50 values for carboplatin were between 0.5-1.6 microgram/mL; there was only a 3.2-fold difference between individual cell lines. Carboplatin administered concomitantly with a taxane had either an additive or supra-additive growth inhibitory effect on all four ovarian carcinoma cell lines. A supra-additive effect occurred after simultaneous exposure of the cells to carboplatin at all tested paclitaxel concentrations in three of four cell lines (UT-OC-3, UT-OC-5, and SK-OV-3). The carboplatin-docetaxel combination had a supra-additive effect at the two highest docetaxel concentrations in two cell lines (UT-OC-4 and UT-OC-5) and at the highest docetaxel concentration in the other two cell lines (UT-OC-3 and SK-OV-3).

CONCLUSIONS

Carboplatin has a synergistic effect when used with paclitaxel or docetaxel. A supra-additive effect is achieved with a wider range of paclitaxel concentrations than docetaxel concentrations.

Effects of paclitaxel with or without cremophor EL on cellular clonogenic survival and apoptosis

Paclitaxel is currently formulated in a vehicle of 50% ethanol and 50% polyethoxylated surfactant cremophor EL. Cremophor EL has been reported to reverse P-glycoprotein-mediated multidrug resistance (MDR) at doses which are clinically achievable. It has also been reported to have a cytotoxic effect per se. In this study we used two different methods to evaluate the survival of cells exposed to paclitaxel with or without cremophor EL and the vehicle alone. Two laryngeal SCC cell lines (UT-SCC-19A and UT-SCC-29) and two ovarian adenocarcinoma cell lines (UT-OC-3 and UT-OC-5) established in our laboratory were investigated. Northern hybridisation was used to study the mdr-1 mRNA expression of the cell lines. With sensitive Northern analyses, these four lines yielded mdr-1 mRNA signals of the expected 4.5 kb size and of variable intensity, generally at higher levels than those in the positive control cell line KB. The 96-well plate clonogenic assay was used to obtain the fraction survival data and apoptosis was recorded by time-lapse video microscopy. Both methods indicate that cremophor EL alone has no effect on cellular survival. Consequently, paclitaxel without cremophor EL is as active as paclitaxel with cremophor EL in vitro.

Characterization of prethymic progenitors within the chicken embryo

The thymic primordium in both birds and mammals is first colonized by cells emerging from the intra-embryonic mesenchyme but the nature of these precursors is poorly understood. We demonstrate here an early embryonic day 7 prethymic population with T lymphoid potential. Our work is a phenotypic analysis of, to date, the earliest embryonic prethymic progenitors arising in the avian para-aortic area during ontogeny. The phenotype of these cells, expressing the cell surface molecules alpha2beta1 integrin, c-kit, thrombomucin/MEP21, HEMCAM and chL12, reflects functional properties required for cell adhesion, migration and growth factor responsiveness. Importantly, the presence of these antigens was found to correlate with the recolonization of the recipient thymus following intrathymic cell transfers. These intra-embryonic cells were also found to express the Ikaros transcription factor, the molecular function of which is considered to be prerequisite for embryonic lymphoid development.

Additive and supra-additive cytotoxicity of cisplatin-taxane combinations in ovarian carcinoma cell lines

The purpose of this study was to compare the growth-inhibitory effect of cisplatin-paclitaxel with that obtained with a cisplatin-docetaxel combination and to assess the type of interaction. Concomitant use of taxanes and cisplatin was studied in seven human ovarian carcinoma cell lines, using the 96-well plate clonogenic assay. Chemosensitivity was expressed in terms of IC50 values, the drug concentration causing 50% inhibition of clonogenic survival. The type of interaction was studied using the area under the survival curve ratios (AUC ratios) obtained by numerical integration. Comparison of the AUC ratio and the surviving fraction (SF) value after taxane alone was made using Student's t-test. The influence of the drug concentration was tested by one-way analysis of variance (Anova). A supra-additive or additive effect was seen when seven ovarian carcinoma cell lines were exposed to paclitaxel or docetaxel concomitantly with cisplatin. A supra-additive effect was found in four cell lines (UT-OC-3, UT-OC-4, UT-OC-5 and SK-OV-3) after simultaneous use of cisplatin with all docetaxel concentrations tested, and in two cell lines (UT-OC-4 and SK-OV-3) when cisplatin was used concomitantly with paclitaxel. A more pronounced supra-additive effect was seen with the combination of cisplatin and docetaxel. The degree of supra-additivity was dose dependent, with increasing synergy after a higher taxane dose. The data obtained in this study suggest that a supra-additive or additive effect can be achieved in ovarian carcinoma with the concomitant use of cisplatin and a taxane.

Radiosensitivity of dermal and tumor fibroblasts derived from the same patient

The in vitro radiosensitivity of dermal fibroblasts has been found to vary between individuals, and a number of studies have also shown that this parameter correlates with radiation-induced late injuries in clinical radiotherapy. In addition, certain genetic disorders are known to effect radiosensitivity, e.g. normal tissues of patients homozygous or heterozygous for the ataxia teleangiectasia gene show unusual sensitivity to radiation both in vivo and in vitro. Thus, it has been assumed that there is a genetically determined component resulting in a certain intrinsic cellular radiation response in an individual. To study this possible relationship between different cells of a specific patient, we established eight pairs of dermal and tumor fibroblast cultures. The donor patients had either adenocarcinoma of the uterus or squamous cell carcinoma (SCC) of the head and neck. The radiosensitivity of these strains was determined by a 96-well plate clonogenic assay, previously used by us for radiosensitivity testing of cancer cells. From a paired comparison, the values for the cell fraction surviving 2.0 Gy (SF2), of both fibroblast strains, were found to be on the same level in five out of eight cases. In patient 6, the SF2 of tumor fibroblasts was significantly higher than that of dermal fibroblasts (P=0.0014). In two additional cases the tendency was the same, but not statistically significant. As groups, the two types of fibroblasts did not differ from each other, mean SF2 values of 0.24+/-0.07 and 0.21+/-0.05, respectively. The SF2 of tumor fibroblasts from SCC patients proved to be significantly higher than that of the adenocarcinoma patients (P=0.030). These preliminary results indicate that the in vitro radiosensitivity of tumor fibroblasts correlates with normal cell sensitivity in many cases, but not in all. The radiosensitivity of tumor fibroblasts also seems to follow the level of in vitro radiosensitivity determined for the corresponding histological type of tumor cells. Further studies are needed to determine more closely the relationship between the radiosensitivities of tumor cells and tumor fibroblasts, thus evaluating the possibility of testing radiosensitivity from tumor fibroblasts in order to estimate tumor response.

Taxane sensitivity of ovarian carcinoma in vitro

Paclitaxel, the first clinically available taxane, has proven to be effective in the treatment of ovarian carcinoma. Docetaxel is the second taxoid derivative which has also shown activity in ovarian carcinoma. These two compounds have clear differences in pharmacokinetics and side-effects. In the present study we have tested the cytotoxic effect of docetaxel in seven ovarian carcinoma cell lines using the 96-well plate clonogenic assay. These results have been compared with data obtained from our recent study on cisplatin and paclitaxel sensitivities of the same cell lines. Chemosensitivity has been expressed as IC50 value, the drug concentration causing 50% inhibition of clonogenic survival. The IC50 values for docetaxel were 0.23-2.30 nM showing a 10-fold difference between individual cell lines. On a molar basis, docetaxel was 1.2 to 2.6 times more active than paclitaxel in six out of seven cell lines. This may be explained by differences in the mechanism of action or by differences in other pharmacological properties.

Vulvar squamous cell carcinoma cell lines are sensitive to paclitaxel in vitro

In the current study, paclitaxel sensitivity of eight vulvar squamous cell carcinoma (SCC) cell lines was tested using a 96-well plate clonogenic assay. The chemosensitivity was expressed as IC50 corresponding to the drug concentration causing 50% inhibition in clonogenic survival. IC50 values were obtained from dose-response curves after fitting the data to the linear quadratic equation. The paclitaxel sensitivity of the eight vulvar SCC cell lines expressed as IC50 varied from 0.6 to 2.9 nM. The observed differences between the individual cell lines were surprisingly small, only 4.8-fold at the most. Paclitaxel sensitivity of vulvar SCC cell lines is of the same magnitude as the paclitaxel sensitivity of endometrial and ovarian carcinoma cell lines tested in our preliminary experiments with the same assay. We have previously studied the intrinsic radiosensitivity of these vulvar SCC cell lines. No correlation could be found between radiosensitivity and paclitaxel sensitivity. These results indicate that vulvar SCC is consistently sensitive to paclitaxel in vitro. The role of chemotherapy in the treatment of vulvar carcinoma has not been clarified yet. The efficacy of paclitaxel should be tested further in clinical trials.

Paclitaxel and cisplatin sensitivity of ovarian carcinoma cell lines tested with the 96-well plate clonogenic assay

Platinum based chemotherapy is the cornerstone of treatment in advanced ovarian carcinoma. Paclitaxel, an unique antimicrotubule agent has shown significant clinical activity in cisplatin-resistant tumours, indicating a lack of cross-resistance. To compare the in vitro sensitivity of ovarian carcinoma to cisplatin and paclitaxel, we tested 7 ovarian carcinoma cell lines with the 96-well plate clonogenic assay. Chemosensitivity was expressed as the IC50 value i.e. the drug concentration causing 50% inhibition of clonogenic survival. IC50 values were obtained from dose-response curves after fitting the data to the linear quadratic equation. The IC50 values for paclitacel were 0.4-3.4 nM, showing an 8.5-fold difference between various cell lines. The IC50 values for cisplatin were 0.1-0.45 ug ml-1 showing only a 4.5-fold difference. This variance is clearly smaller than the 25-fold difference observed with the same method in endometrial carcinoma cell lines (Rantanen et al, Br J Cancer 69: 482-86, 1994). In accordance with clinical findings, no cross-resistance or correlation between sensitivity to paclitaxel and cisplatin could be demonstrated.

Stage-specific apoptosis in the rat seminiferous epithelium: quantification of irradiation effects

The effects of 3 Gy local X-irradiation on the adult rat testis were studied together with exact determination of the radiation dose distribution in the testis. Seminiferous tubule segments were isolated 8-66 hours postirradiation (p.i.), squashed between a microscope slide and a coverslip, and the exact stage of the seminiferous epithelial cycle was identified under a phase-contrast microscope. The squash preparations were subjected to in situ end labeling (ISEL) for visualization and quantification of apoptotic cells. In controls, the highest numbers of apoptotic cells were scored in stages XII-XIV and I. In situ end-label staining of cells was observed in A3-A4 spermatogonia, spermatocytes at zygotene, pachytene, and meiotic division phases, as well as in early spermatids. In irradiated testes, from 8 hours p.i. and onward, intermediate- and B-type spermatogonia were sensitive at stages II-VI. At 42 hours, in stage I, elevated numbers of degenerating spermatocytes were seen. Most of them had not undergone meiotic divisions at stage XIV and showed an apoptotic type of degeneration at stage I. At the time of irradiation, the cells were in stage XIII, suggesting that diakinetic spermatocytes are particularly sensitive to irradiation. Also, preleptotene-zygotene spermatocytes in stages VII-XII were sensitive to irradiation. Apoptotic-type of cell degeneration was confirmed by living cell squash preparations, electron microscopy, and DNA electrophoresis. In conclusion, irradiation may provide a useful model system for studying apoptosis, and its control in spermatogonia and meiotically dividing cells.

In vitro concurrent paclitaxel and radiation of four vulvar squamous cell carcinoma cell lines

BACKGROUND

The antitubule agent paclitaxel causes a cell cycle blockage in the most radiosensitive part of the cell cycle, the G2/M phase. The possible radiosensitizing effect of paclitaxel was tested in four vulvar (UM-SCV-1A, UM-SCV-1B, UM-SCV-2, and UM-SCV-4) squamous cell carcinoma (SCC) cell lines.

METHODS

A 96-well plate clonogenic assay was performed with paclitaxel and radiation, both separately and concomitantly. Survival data were fitted to the linear quadratic model. The area under the curve, equivalent to the mean inactivation dose (D), was obtained by numerical integration. The effect of paclitaxel on radiosensitivity was measured as the AUC ratio (paclitaxel plus radiation: radiation alone). This ratio was compared with the surviving fraction (SFP) after paclitaxel alone.

RESULTS

Paclitaxel concentrations of 0.4 to 2.0 nanomolar (nM) caused 1 to 70% inhibition of clonogenic survival. The AUC values of the cell lines were 1.9 to 2.9 gray. A full additive effect was observed when paclitaxel and radiation were administered concurrently; however, a supra-additive effect never occurred. The type of paclitaxel radiation interaction was not affected by the concentration of the drug nor did the type of interaction vary between cell lines studied.

CONCLUSIONS

Paclitaxel and radiation used concomitantly produced a clear additive effect at all concentrations and in all vulvar carcinoma cell lines tested. Although no supra-additive effect was observed, the additive effect already in nM concentrations could be beneficial in clinical use and, therefore, requires further investigation.

Endometrial cancer cell lines are sensitive to paclitaxel

We have previously reported a 24 fold difference in the cisplatin sensitivity and a 12 fold difference in carboplatin sensitivity of endometrial carcinoma cell lines. In this study as evaluate paclitaxel sensitivity of the same cell lines. We tested nine endometrial cancer cell lines with the 96-well plate clonogenic assay using limiting dilution. The chemosensitivity was expressed as IC50 value, the drug concentration causing 50% inhibition of clonogenic survival. IC50 values were obtained from dose-response curves after fitting the data to the linear quadratic equation. The IC50 values for paclitaxel were 0.49 - 2.3 nM showing only a 4.7 fold difference between various cell lines. No correlation could be demonstrated between in vitro paclitaxel and platinum analog sensitivities of endometrial adenocarcinoma cell lines. The variance in paclitaxel sensitivity of different cell lines was little. Our results suggest that endometrial adenocarcinoma cell lines tested with the same methods. The clinical efficacy of paclitaxel in the treatment of endometrial cancer should further be evaluated in clinical trials.

Comparison of cellular radiosensitivity between different localizations of head and neck squamous-cell carcinoma

The prognosis of carcinomas arising from various sites in the head and neck varies even when the stage of the disease is taken into consideration, e.g. laryngeal carcinoma has a more favourable prognosis compared to oral-cavity malignancies. The purpose of this study was to evaluate intrinsic cellular radiosensitivity as one possible explanation for the observed differences in the survival rates of different anatomical groups. The radiation survival curves were determined for well characterized cell lines derived from laryngeal carcinoma (n = 14), pharyngeal carcinoma (n = 6), carcinoma of the oral cavity (n = 14) and the skin of the face (n = 3). The intrinsic radiosensitivity was expressed as area under the survival curve (AUC) values, and this cellular parameter was compared with clinical data and survival of the patients. The intrinsic radiosensitivity in the whole group varied between 1.0 Gy and 2.8 Gy with an average of 1.9 Gy. The mean AUC values for the laryngeal cell lines were 2.0 Gy +/- 0.2, for the oral cavity 1.8 +/- 0.3 Gy, for the pharynx 1.8 +/- 0.2 Gy and for cutaneous carcinoma 2.1 +/- 0.1 Gy. There was a slight difference between the groups of glottic and supraglottic cell lines (mean 1.8 +/- 0.2 Gy and 2.1 +/- 0.3 Gy, respectively), which is consistent with the differences in clinical curability of these cancers. Otherwise, the differences in cellular radiosensitivity of the carcinoma groups studied did not reach statistical significance. These results indicate that the intrinsic radiosensitivity of squamous-cell carcinoma (SCC) of the larynx does not significantly differ from that of SCC of other sites of the head and neck. Variations in the intrinsic radiosensitivity do not as such seem to explain the observed differences in radiocurability of SCC variously localized in the head and neck.

Low-dose and conventional-dose high resolution CT of pulmonary changes in breast cancer patients treated by tangential field radiotherapy

Twenty-seven consecutive breast cancer patients receiving tangential field radiation therapy were followed by high resolution CT (HRCT) in order to compare the accuracy of reduced-dose HRCT and conventional-dose HRCT in the evaluation of subtle pulmonary changes. Thin section 1-mm HRCT images were obtained at identical levels at 120 kVp, with 320 mAs, 200 mAs, 160 mAs, 120 mAs and 60 mAs settings. HRCT was performed during the planning of radiotherapy and 4, 8 and 24 weeks after the completion of radiotherapy. Radiation was administered according to an individual CT-based plan by tangential fields with 4 or 6 MV photons to the whole breast given with 5 fractions of 1.9 Gy weekly to a total dose of 50 Gy. The tumor bed was boosted by electrons to 60 Gy. Pathological changes were detected in 21 examinations of 10 patients: 9 patients out of 27 (33%) showed radiation induced changes; 1 patient developed metastases within the irradiated volume. Septal thickening appeared in 5 patients at 4 weeks and in another 5 patients at 8 weeks. Parenchymal consolidation was detected in 1 patient at 4 weeks and in 5 patients at 8 weeks. HRCT using 160 mAs yield good quality images of subtle radiation induced injuries. The diagnostic validity of HRCT using lower than 160 mAs depends on the detail analyzed.

The intrinsic radiosensitivity and sublethal damage repair capacity of five cervical carcinoma cell lines tested with the 96-well-plate assay

We have tested the intrinsic radiosensitivity and capacity for sublethal damage repair (SLDR) in split-dose experiments with the 96-well plate clonogenic assay. Four out of five cell lines were squamous-cell carcinoma (SCC) lines (CaSki, ME-180, HX151c, HX156c) and one cell line was established from glassy-cell carcinoma (UM-GCC-1). Comparison of radiosensitivities was by with D value, the mean inactivation dose. D for these cell lines varied from 1.7 Gy to 2.5 Gy. As a group, cervical carcinoma cell lines were more radioresistant than endometrial adenocarcinoma cell lines tested with the same assay, but more radiosensitive than vulvar SCC lines. Three cell lines showed clear SLDR, but two cell lines were unable to carry out this function. Furthermore, cell lines capable of SLDR also showed significant increase in survival when D values were compared after the radiation dose was split into three instead of two fractions. These results indicate the importance of adding another radiobiological parameter to the intrinsic radiosensitivity when predictive tests are planned.

Squamous cell carcinoma is highly sensitive to taxol, a possible new radiation sensitizer

We studied the sensitivity of seven cell lines established from laryngeal carcinoma to the cytotoxic drug paclitaxel (Taxol) in vitro. In all four cell lines tested for growth inhibition, paclitaxel reduced growth at low concentrations, and in two cell lines growth was completely inhibited at a paclitaxel concentration of only 1 x 10(-8) M. Flow cytometric data showed a G2/M block in all seven cell lines after exposure to paclitaxel for 24 h at a concentration of 1 x 10(-8) M. This concentration is about one-one hundredth fold smaller than those measured in serum after a single intravenous dose of about 200 mg/m2. The high in vitro sensitivity of laryngeal cancer cell lines to paclitaxel,and the G2/M block suggest that the drug may potentially be used in conjunction with radiotherapy.

Simultaneous cisplatin and radiation in endometrial adenocarcinoma cell lines

The effects of concomitantly administered cisplatin and radiation were evaluated in four recently established endometrial adenocarcinoma cell lines. We used the 96-well clonogenic assay to obtain survival data which were fitted to the linear quadratic model. The area under the survival curve (AUC) was obtained by numerical integration. It turned out that there was only a systematic additive cytotoxic effect and no supra-additive, true radiosensitising effect could be found. The results were not affected by the cisplatin dose used, the intrinsic radiosensitivity of the cell lines or the sensitivity of the cells to cisplatin.

Characterization and radiosensitivity of UT-EC-2A and UT-EC-2B, two new highly radiosensitive endometrial cancer cell lines derived from a primary and metastatic tumor of the same patient

UT-EC-2A was established from a patient with moderately differentiated Stage III endometrial adenocarcinoma with squamous metaplasia. UT-EC-2B was established from the same patient 17 months later from a metastasis in the left supraclavicular fossa. The origin of these cell lines was confirmed by DNA identity testing. Nude mice tumors produced by UT-EC-2A and UT-EC-2B cells recapitulated the histology of the original human tumors. Flow cytometric DNA contents of both primary and metastatic human tumors as well as corresponding nude mice tumors were diploid. The S-phase fractions of both cell lines were > or = 30%. The UT-EC-2A cell line was cytogenetically normal. The UT-EC-2B cell line had quite simple karyotype at low passage with an extra i(18p) and a deletion 21q, but at higher passages an additional three-way translocation 5;14;19 was observed. Radiosensitivity of the cell lines was tested with the 96-well plate clonogenic assay. The areas under the survival curves corresponding to the mean inactivation doses of UT-EC-2A and UT-EC-2B were 0.65 +/- 0.10 and 0.60 +/- 0.06 Gy, respectively. Measured survival at 2.0 Gy (SF2) was 0.042 for UT-EC-2A, 0.044 for UT-EC-2B, and 0.2 for skin fibroblasts. These cell lines are among the most radiosensitive human cancer cell lines described in the literature. Studying the characteristics of primary and metastatic cells derived from the same patient provides an opportunity to evaluate tumor progression.

Dosimetry of irradiation models. The 96-well clonogenic assay for testing radiosensitivity of cell lines

Radiation experiments with cells in single cell suspension in test tubes and on 96-well plates were carried out and compared. The cells originated from cell lines established from carcinomas of the floor of the mouth and from endometrial carcinoma. Two irradiation models were constructed. Both models allowed the absorbed doses to the cells to be administered with a high accuracy in both experimental settings (better than 5.0%). These irradiation models were compared on cancer cell lines with dissimilar inherent radiation sensitivity and histologic type (UM-SCC-1 resistant, UM-SCC-14A sensitive, and UT-EC-2B highly sensitive); various radiation doses were used. The fractions of surviving cells as a function of radiation dose were compared: there was no significant difference between cells irradiated in test tubes and cells irradiated in 96-well plates. Thus, if the absorbed doses in cells suspended in a tube and in a plate were the same, the survival was similar regardless of the type of irradiation model.

Samarium-153-EDTMP in bone metastases

Thirty-five patients with painful bone metastases arising from a variety of tumor types underwent a clinical trial in which 153Sm-EDTMP was injected as a single intravenous dose. The injection ranged in amount from 330 MBq to 1110 MBq of 153Sm-EDTMP. Pain relief usually occurred within one week after administration. The duration of pain relief lasted from 2 to 17 weeks. A detectable degree of pain palliation was experienced by 80% of the treated patients; 54% reported substantial or complete pain relief. Due to the small number of patients, no clear-cut dose-related response was detectable. Moderate myelosuppression was observed in one patient (WHO grade III). The metastatic lesion-to-normal bone ratios remained constant (varying from 1.5 to 4.8) for at least 5 days post-injection. 153Sm cleared very rapidly from the blood. Less than 1% of the injected dose remained in circulation at 4 hours post-injection. No local accumulation of the tracer could be detected outside the skeleton. Urinary excretion was quite complete at 6 hours post-injection. The biodistributions of 153Sm-EDTMP and 99mTc-DPD are very similar in metastatic and normal bone; thus, bone scanning can be used for patient selection and followup. According to our results, it seems that higher doses of 153Sm-EDTMP can be given safely and without any irreversible myelosuppression.

Sublethal damage repair after fractionated irradiation in endometrial cancer cell lines tested with the 96-well plate clonogenic assay

Two long-established and seven newly established endometrial adenocarcinoma cell lines were tested for their capacity to repair sublethal damage after fractionated irradiation. Cell survival was determined with the 96-well plate clonogenic assay based on limiting dilutions. Total radiation doses of 0.75 Gy, 1.25 Gy, 2.50 Gy, 5.00 Gy and 7.50 Gy were used either as a single dose or divided into two or three equal fractions with a 24 h interval. Survival data were fitted to the linear quadratic model, and the area under the survival curve (AUC), equivalent to the mean inactivation dose, was obtained with numerical integration. The amount of sublethal damage repair (SLDR) was expressed as an area-under-the-curve (AUC) ratio comparing survivals from fractionated-dose with those from single-dose experiments. SLDR capacity of the cell lines expressed as an AUC ratio varied between 1.00 and 1.59, and the mean was 1.17. Two highly radiosensitive cell lines were found to be SLDR-deficient, but most of the cell lines studied had some SLDR capacity. We have earlier shown that endometrial cancer cell lines as a group are more radiosensitive than squamous-cell carcinoma (SCC) lines. Data obtained in this study suggest that the capacity for SLDR in these cell lines is rather limited compared with the majority of SCC lines tested. This finding underlines further the high radioresponsiveness of endometrial cancer.

Comparative evaluation of cisplatin and carboplatin sensitivity in endometrial adenocarcinoma cell lines

Platinum analogues are frequently used in the treatment of advanced or recurrent endometrial cancer. To study the sensitivity of endometrial cancer to cisplatin and carboplatin, we tested two long-established (RL95-2, KLE) and six new cell lines (UM-EC-1, UM-EC-2, UM-EC-3, UT-EC-2A, UT-EC-2B, UT-EC-3) using the 96-well-plate clonogenic assay. This assay has proven to be suitable for testing chemosensitivity of both adenocarcinoma and squamous cell carcinoma. The chemosensitivity was expressed as an IC50 value, the drug concentration causing 50% inhibition of clonogenic survival. IC50 values were obtained from dose-response curves after fitting the data by the linear quadratic equation, F = exp[-(alpha D + beta D2)]. The IC50 values of the two platinum derivatives varied considerably. The values for cisplatin varied between 0.022 microgram ml-1 and 0.56 microgram ml-1 and the corresponding values for carboplatin were 0.096-1.20 microgram ml-1. The range of the ratios between carboplatin IC50 and cisplatin IC50, from 1.5:1 to 4.4:1, was rather narrow. However, no constant ratio between carboplatin IC50 and cisplatin IC50 could be detected. The equivalent doses with regard to efficacy of these two platinum analogues remain to be determined.

Intercomparison of radiotherapy treatment planning systems for external photon and electron beam dose calculations

Dose distributions calculated by six different treatment planning systems (TPSs), used by the hospitals in Finland or in Russia, were compared with measured dose distributions. Five typical cases of irradiation were selected: regular fields, oblique incidence, irregular field, wedge field and inhomogeneity in a water equivalent phantom. The beam data for each TPS where those pertaining to the beam where the comparative relative measurements were performed. The results indicate that the dose distributions produced by different TPSs can differ from each other as well as from the measured dose distributions up to a level which is not acceptable in terms of the ICRU recommendations. Greatest differences seem to be related to the omission or undue consideration of the scatter components of the beam.

Comparison of effects of 0.5 and 3.0 Gy X-irradiation on lipid peroxidation and antioxidant enzyme function in rat testis and liver

The prooxidant effect of X-irradiation on rat testis and liver tissue was studied with doses of 0.5 and 3.0 Gy; the latter dose kills the proliferating spermatogonia and causes a maturation-depletion process in the germ cells. The level of lipid peroxidation, measured by the formation of diene conjugates and thiobarbituric acid-reactive substances (TBARS) and the activities of the antioxidant enzymes were determined 0.5 hours, 1 day, 7 days, and 31 days after the exposure. In the liver, increased levels of diene conjugation (+36%, P < 0.05) in the group of 3.0 Gy at 0.5 hours indicated increased lipid peroxidation. At the same time, TBARS were increased (+25%, P < 0.05) in the group of 0.5 Gy, but not in the 3.0-Gy group. In the testis, diene conjugation was not determined at 0.5 hours postirradiation, and at day 1 it was at the control level. The level of TBARS in the testis was below control (-11%, P < 0.01) in the 3.0-Gy group at day 1. At day 31 after 3.0 Gy in the testis, an increase in the amount of conjugated dienes (+24%, P < 0.01) was observed in parallel with a decreased level of TBARS (-15%, P < 0.01). The activity of superoxide dismutase (SOD) was decreased in the testis at 0.5 hours postirradiation (-28%, P < 0.05, and -29%, P < 0.05, in the groups of 0.5 and 3.0 Gy), whereafter it returned to normal by day 7. In the liver, such inactivation of SOD was not observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Carboplatin-radiation interaction in squamous cell carcinoma cell lines

Chemoradiotherapy has been considered one of the most promising improvements in the treatment of advanced head and neck cancer. This article describes in vitro chemosensitivity to carboplatin in five squamous cell carcinoma cell lines established from head and neck cancers and in one vulvar squamous cell carcinoma cell line. Sensitivity to carboplatin was found to vary markedly when using the 96-well plate clonogenic assay and continuous drug exposure. The difference in carboplatin response between the most sensitive and the most resistant cell lines was fourfold. No cross-resistance was observed between inherent radiosensitivity and chemosensitivity. Effects of concomitant use of carboplatin and radiation were further investigated in the two cell lines that were found to be most sensitive to carboplatin. The drug was administered 1 hour before acute radiation doses, and an additive effect was observed in both cell lines.

Sublethal damage repair in squamous cell carcinoma cell lines

Squamous cell carcinoma (SCC) cell lines recently established from head and neck tumors were studied for their capability of repairing sublethal radiation induced damage (SLDR). Total doses of 1.25, 2.50, 5.00, and 7.50 Gy were used either as a single dose or split in two equal fractions with a 24 h interval. Cell survival was determined using a 96-well plate clonogenic assay based on limiting dilution. Survival data was fitted by linear quadratic model, and the area under the survival curve (AUC) was obtained with numerical integration. The amount of SLDR was expressed as AUC-ratio comparing survivals from split dose vs single dose experiments. SLDR capacity was observed to vary markedly between individual cell lines (AUC-ratios 1.0-1.5). The relatively radiation-sensitive cell lines had a tendency toward higher SLDR proficiency (correlation coefficient 0.85). The differences in repair capacity could not be explained by the differences in doubling times of the cell lines. The inverse relationship between SLDR capacity and inherent radiosensitivity could explain the poor radiocurability of the sensitive donor tumors. Two of the most resistant cell lines were found SLDR deficient. This is a novel finding, since SLDR has been previously reported in all studied cells.

Radiation sensitivity of endometrial carcinoma in vitro

The role of radiation therapy is essential in the treatment of endometrial carcinoma. The present knowledge of the radiation sensitivity of endometrial carcinoma is mostly empirical and based on clinical trials. To study the inherent radiation sensitivity of endometrial carcinoma, we tested two long-established cell lines (RL95-2, KLE) and four new, low-passage cell lines (UM-EC-1, UM-EC-2, UM-EC-3, UT-EC-1) by using a 96-well plate clonogenic assay. This method has proved to be suitable for clonogenic studies of both squamous cell carcinomas (SCC) and adenocarcinomas in our recent works. Plating efficiencies of the cell lines tested varied from 0.005 to 0.45. Cells were irradiated in suspension with a 4-MeV linear accelerator at a dose rate of 2.0 Gy/min. Survival data were fitted by the linear quadratic function F = exp (-(alpha D + beta D2)). Radiation sensitivity was expressed as the area under the curve (AUC), equivalent to the mean inactivation dose. UM-EC-1 and UT-EC-1 were the most radiation-resistant cell lines tested (AUC greater than 1.6 Gy), while UM-EC-3 was the most sensitive (AUC = 1.0 Gy). The difference in radiation sensitivity between these cell lines was statistically significant (P less than 0.001). As a group, endometrial carcinoma cell lines were clearly more radiosensitive than most SCC lines of head and neck and vulva earlier tested by us. However, our results showed also great variance in the inherent radiation sensitivity between individual cell lines derived from endometrial carcinomas.

Effects of radiation fractionation on four squamous cell carcinoma lines with dissimilar inherent radiation sensitivity

The effect of radiation fractionation was investigated using a new 96-well-plate clonogenic assay in four squamous cell carcinoma lines. Earlier experiments had shown that two of the cell lines (UT-SCC-1A and UM-SCC-14A) were inherently relatively sensitive to irradiation, and two (UM-SCC-1 and UM-SCV-1A) relatively resistant. All of the four carcinomas from which the cell lines were established had poor clinical outcome. The radiation doses were given as a single exposure, or split into two or three equal fractions with a 24-h interval. The two inherently sensitive cell lines showed enhanced survival after radiation fractionation as compared with a single dose, whereas the resistant cell lines did not. The result suggests that both the inherent resistance of cancer cells to irradiation and the repair of sublethal radiation damage may lead to treatment failure, and that shortening of the total irradiation time may overcome cancer cell recovery between fractions in some, but not in all carcinomas.

DNA-flow cytometry of defined stages of rat seminiferous epithelium: effects of 3 Gy of high-energy X-irradiation

Testes of adult Sprague-Dawley rats were irradiated locally by 3 Gy of 4 MeV X-rays produced by a linear accelerator. This type and dose of radiation gives an even distribution through the testis and selectively kills the proliferating spermatogonia. The seminiferous tubular cells were quantified by DNA flow cytometry at defined stages of the epithelial cycle at 7, 17, 22, 38, 52, and 80 days after irradiation. The flow cytometric technique was modified by using frozen instead of fresh samples. Freezing did not alter cell numbers when compared with fresh samples. At 7 days post-irradiation no significant changes were observed in any cell population by DNA flow cytometry, whereas histological analysis revealed a reduction in intermediate and type B spermatogonia. At 17 and 22 days post-irradiation, the number of cells at meiotic prophase (4C) was decreased, particularly in stages II-V of the cycle. In stages VII-VIII, cell numbers were 40 and 31%, and in stages IX-XIII, 24 and 43% of that in non-irradiated controls at 17 and 22 days, respectively. At 38 days after irradiation, both 4C and 1C (haploid) cells were decreased in number. The 4C cells were reduced to 24, 17, and 13% of that in non-irradiated controls in stages II-V, VII-VIII, and IX-XIII of the cycle, respectively. The corresponding numbers of 1C cells were 5, 17, and 4%. At 52 days after irradiation, 1C cells had declined to 38 and 19% of control values in stages II-V and IX-XIII, respectively. In stages II-V, 1C' cells (haploid cells with condensed nuclei) declined to 28% of controls at 52 days. The present data provide a quantitative basis for the use of X-ray-irradiated rat testes as a model system in experiments pursuing interactions between Sertoli cells and spermatogenic cells.

Radiation response of vulvar squamous cell carcinoma (UM-SCV-1A, UM-SCV-1B, UM-SCV-2, and A-431) cells in vitro

Standard therapy for squamous cell carcinoma (SCC) of the vulva consists of radical surgery and inguinal node dissection. Radiation therapy has been used for preoperative treatment in advanced cases to reduce the size of the tumor, and also as the only treatment in inoperable or recurrent disease. To study the inherent radiation sensitivity of vulvar carcinoma, we tested three new vulvar carcinoma cell lines and the long-established cell line A-431 by using a 96-well plate clonogenic assay, earlier shown by us to be suitable for survival studies of SCC. SCC and adenocarcinoma cell lines derived from other sites were used as a reference. Cells were irradiated with a 4-MeV linear accelerator at a dose rate of 2.0 Gy/min. The vulvar cell lines were found to be highly resistant to radiation with the average mean inactivation dose of 3.44 +/- 0.34 Gy as calculated from the area under the curve. The results were consistent in repeated experiments and for all cell lines. The average value for area under the curve was 1.79 +/- 0.30 for the other SCC lines tested. The values for area under the curve differed significantly (P less than 0.0001) between the vulvar lines and reference SCC lines. These results indicate that vulvar SCC cells in vitro express exceptional inherent radioresistance, and thus development of other forms of additional treatment would be more advantageous in advanced cases.

Imaging of rats with mammary cancer with two 2-deoxy-2-[18F]fluoro-D-hexoses

Rats with mammary cancer were imaged by scintigraphy: 10 rats with 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) and 10 rats with [18F]F-D-galactose. The uptake of both tracers was similar in the tumors--the tumor-to-normal tissue ratio was 2.7 +/- 1.1 for [18F]FDG and 2.3 +/- 0.9 for [18F]FDGal at 120 min after injection. In addition to the tumors [18F]FDG accumulated in the brain, bladder and heart, [18F]FDGal in the brain, bladder and liver. [18F]FDGal may be useful for tumor imaging in man; further studies should be addressed to elucidate the mechanism of [18F]FDGal uptake into tumors.

Allogeneic bone marrow transplantation in multiple myeloma: a report of four cases

Allogeneic bone marrow transplantation offers a new and promising form for treatment of multiple myeloma incurable with chemotherapy. We present four cases of advanced multiple myeloma given bone marrow transplantation from HLA-identical and MLC-negative sibling donors. One patient had a recurrent plasmacytoma 8 months later and one died 12 days after the transplantation whereas the other two are in good clinical remission 15 and 19 months post-transplantation.

Preliminary biodistribution studies with a hybrid positron scanner

The hybrid positron scanner is a scanning device for imaging with short-lived positron-emitting radioisotopes. It is especially suitable for total body scanning studies. The scanner consists of two moveable parallel detectors, which are NaI(Tl)-crystals 40 cm long and 5 cm in diameter with a photomultiplier at each end. One detector is above and the other below the patient. The coordinate in the direction perpendicular to the crystal axis is determined from mechanical movement of the detectors. The coordinate along the crystal axis is determined from the signals of the photomultipliers. The specifications of the hybrid positron scanner are presented. Biodistribution studies in rabbits on the accumulation of 18F in the skeleton and on the 13NH3 distribution in various organs are described. The regional pharmacokinetics of 11C-ethanol in man after peroral administration of the tracer is presented.