Low-radiation environment affects the development of protection mechanisms in V79 cells.

Very little is known about the influence of environmental radiation on living matter. In principle, important information can be acquired by analysing possible differences between parallel biological systems, one in a reference-radiation environment (RRE) and the other in a low-radiation environment (LRE). We took advantage of the unique opportunity represented by the cell culture facilities at the Gran Sasso National Laboratories of the Istituto Nazionale di Fisica Nucleare, where environment dose rate reduction factors in the underground (LRE), with respect to the external laboratory (RRE), are as follows: 10(3) for neutrons, 10(7) for directly ionizing cosmic rays and 10 for total γ-rays. Chinese hamster V79 cells were cultured for 10 months in both RRE and LRE. At the end of this period, all the cultures were kept in RRE for another 6 months. Changes in the activities of antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPX) and spontaneous mutation frequency at the hypoxanthine-guanine phosphoribosyl transferase (hprt) locus were investigated. The results obtained suggest that environmental radiation might act as a trigger of defence mechanisms in V79 cells, specifically those in reference conditions, showing a higher degree of defence against endogenous damage as compared to cells grown in a very low-radiation environment. Our findings corroborate the hypothesis that environmental radiation contributes to the development of defence mechanisms in today living organisms/systems.

The Cosmic Silence experiment: on the putative adaptive role of environmental ionizing radiation.

Previously we reported that yeast and Chinese hamster V79 cells cultured under reduced levels of background environmental ionizing radiation show enhanced susceptibility to damage caused by acute doses of genotoxic agents. Reduction of environmental radiation dose rate was achieved by setting up an underground laboratory at Laboratori Nazionali del Gran Sasso, central Italy. We now report on the extension of our studies to a human cell line. Human lymphoblastoid TK6 cells were maintained under identical in vitro culture conditions for six continuous months, at different environmental ionizing radiation levels. Compared to "reference" environmental radiation conditions, we found that cells cultured in the underground laboratories were more sensitive to acute exposures to radiation, as measured both at the level of DNA damage and oxidative metabolism. Our results are compatible with the hypothesis that ultra-low dose rate ionizing radiation, i.e. environmental radiation, may act as a conditioning agent in the radiation-induced adaptive response.

Role of SPECT/CT in the preoperative assessment of hyperparathyroid patients.

PURPOSE: Our purpose was to assess the clinical value and additional benefit of fusion single-photon computed tomography (SPECT) and computed tomography (CT) images in locating the parathyroids in a selected group of patients affected by primary (PHP) and secondary hyperparathyroidism (SHP). MATERIALS AND METHODS: Sixteen patients (11 women and five men; age range 35-80 years) with severe hyperparathyroidism (HP) (ten PHP, six SHP) were studied by ultrasound (US), and, after i.v. injection of 370 MBq of 99mTc-sestamibi, by planar parathyroid scintigraphy, SPECT and SPECT/CT using a dual-detector scintillation camera GE Infinia Hawkeye. All patients underwent parathyroidectomy. RESULTS: US findings were inconclusive in 12/16 patients affected by multinodular goitre, and two probable eutopic parathyroid glands were identified. "Double phase" parathyroid scintigraphy identified 14 probable parathyroid glands, SPECT 23 (14 ectopic and nine eutopic) and SPECT/CT confirmed all 23 probable parathyroid lesions, offering more precise localisation and an evident improvement in diagnostic accuracy. Sixteen of these foci of increased uptake were hyperplastic parathyroid glands, six were adenomas, one was a parathyroid carcinoma and one was a thyroid follicular carcinoma. Surgical detection of the 23 sestamibi-positive lesions was correctly matched with 100% of SPECT/CT images and 61% of SPECT data alone. Hybrid imaging thus provided additional data in 39% of lesions, and in three patients with retrotracheal glands, it modified the surgical approach. CONCLUSIONS: We believe 99mTc-sestamibi SPECT/CT to be a more reliable presurgical method to study a patient subgroup affected by PHP or SHP in whom conventional US and other scintigraphic methods have failed for intrinsic reasons due to the concomitant presence of multinodular goitre or ectopic parathyroid gland. The additional practical benefit derived from this methodology was evident. In fact, anatomical information provided by CT enables precise localisation of the functional abnormalities highlighted by SPECT, and both are essential to a correct surgical approach.

Frontal cortical perfusion abnormalities related to gluten intake and associated autoimmune disease in adult coeliac disease: 99mTc-ECD brain SPECT study.

OBJECTIVE: Since brain perfusion abnormalities have been described by single-photon emission computed tomography in some autoimmune diseases, the aim of the present study was to evaluate the incidence of perfusion abnormalities by brain single-photon emission computed tomography in a group of coeliac disease patients, and to investigate whether gluten intake and associated autoimmune diseases may be considered risk factors in causing cerebral impairment. METHODS: Thirty-four adult coeliac patients (16 on a gluten-free diet and 18 on a gluten-containing diet, 18 (53%) with autoimmune diseases) underwent 99mTc-ethyl cysteinate dimer brain single-photon emission computed tomography and qualitative evaluation of brain perfusion was performed together with a semiquantitative estimation using the asymmetry index. Ten subjects on our database, matched for sex, age and ethnic group, who were proved normal by histology ofjejunal mucosa (four males and six females; median age 39 years, range 27-55 years), were included as control group. RESULTS: Twenty-four out of 34 patients (71%) showed brain single-photon emission computed tomography abnormalities confirmed by abnormal regional asymmetry index (>5%; range 5.8-18.5%). Topographic comparison of the brain areas showed that the more significant abnormalities were localised in frontal regions, and were significantly different from controls only in coeliac disease patients on unrestricted diet. The prevalence of single-photon emission computed tomography abnormalities was similar in coeliac disease patients with (74%) and without (69%) associated autoimmune disease. CONCLUSIONS: Abnormalities of brain perfusion seem common in coeliac disease. This phenomenon is similar to that previously described in other autoimmune diseases, but does not appear to be related to associated autoimmunity and, at least in the frontal region, may be improved by a gluten-free diet.

Brain perfusion abnormalities in patients with euthyroid autoimmune thyroiditis.

PURPOSE: Brain perfusion abnormalities have recently been demonstrated by single-photon emission computed tomography (SPECT) in rare cases of severe Hashimoto's thyroiditis (HT) encephalopathy; moreover, some degree of subtle central nervous system (CNS) involvement has been hypothesised in HT, but no direct evidence has been provided so far. The aim of this study was to assess cortical brain perfusion in patients with euthyroid HT without any clinical evidence of CNS involvement by means of 99mTc-ECD brain SPECT. Sixteen adult patients with HT entered this study following informed consent. METHODS: The diagnosis was based on the coexistence of high titres of anti-thyroid auto-antibodies and diffuse hypoechogenicity of the thyroid on ultrasound in association with normal circulating thyroid hormone and TSH concentrations. Nine consecutive adult patients with non-toxic nodular goitre (NTNG) and ten healthy subjects matched for age and sex were included as control groups. All patients underwent 99mTc-ECD brain SPECT. Image assessment was both qualitative and semiquantitative. Semiquantitative analysis was performed by generation of four regions of interest (ROI) for each cerebral hemisphere--frontal, temporal, parietal and occipital--and one for each cerebellar hemisphere in order to evaluate cortical perfusion asymmetry. The Asymmetry Index (AI) was calculated to provide a measurement of both magnitude and direction of perfusion asymmetry. RESULTS: As assessed by visual examination, 99mTc-ECD cerebral distribution was irregular and patchy in HT patients, hypoperfusion being more frequently found in frontal lobes. AI revealed abnormalities in 12/16 HT patients, in three of the nine NTNG patients and in none of the normal controls. A significant difference in the mean AI was found between patients with HT and both patients with NTNG (p<0.003) and normal controls (p<0.001), when only frontal lobes were considered. CONCLUSION: These results show the high prevalence of brain perfusion abnormalities in euthyroid HT. These abnormalities are similar to those observed in cases of severe Hashimoto's encephalopathy and may suggest a higher than expected involvement of CNS in thyroid autoimmune disease.

Influence of a low background radiation environment on biochemical and biological responses in V79 cells.

We present the results of an experiment aimed at comparing the effects of different background radiation environments on metabolism and responses to gamma-rays and cycloheximide of cultured mammalian cells. Chinese hamster V79 cells were maintained in exponential growth in parallel for up to 9 months at the Istituto Superiore di Sanità (ISS) and at the INFN-Gran Sasso underground Laboratory (LNGS) where exposure due to gamma-rays and to radon was reduced by factors of about 70 and 25, respectively. After 9 months the cells grown at the LNGS (cumulative gamma dose about 30 microGy, average radon concentration around 5 Bq/m(3)), compared to the cells grown at the ISS (cumulative gamma-ray dose about 2 mGy, average radon concentration around 120 Bq/m(3)), exhibited i). a significant increase of the cell density at confluence, ii). a significantly higher capacity to scavenge organic and inorganic hydroperoxides but a reduced scavenging capacity towards superoxide anions and iii). an increase in both the basal hprt mutation frequency and sensitivity to the mutagenic effect of gamma-rays. The cells grown at the LNGS also showed a greater apoptotic sensitivity starting at the third month of culture, that was no longer detected after 9 months. Overall, these data suggest a role of background ionizing radiation in determining an adaptive response, although they cannot be considered conclusive.

Comparison of MRI, EEG, EPs and ECD-SPECT in Wilson's disease.

OBJECTIVES: The purpose of this study is to evaluate the efficiency of a few methodologies in detecting anatomo-functional brain abnormalities in patients with Wilson's disease. MATERIALS AND METHODS: Twenty-three patients with Wilson's disease underwent almost simultaneously brain magnetic resonance imaging (MRI), computerized electroencephalography (EEG), multimodal evoked potentials (EPs) and ECD single photon computerized tomography (SPECT) evaluation. The clinical picture was of the neurologic type in 8 patients and of the hepatic type in 15. RESULTS: MRI was abnormal in 7 patients with neurological manifestations. The EPs proved pathologic in 7 neurologically symptomatic patients and in 4 cases with hepatic form. These results agree with those reported in other case studies. The EEG records were abnormal only in 3 cases. Nevertheless, the most interesting finding of this study is the particular frequency (86%) of diffuse or focal decrease of ECD uptake shown by brain SPECT. CONCLUSION: We highlight the use of this interesting procedure in the therapeutic monitoring of this disease.

Central nervous system involvement in systemic lupus erythematosus: cerebral imaging and serological profile in patients with and without overt neuropsychiatric manifestations.

The aim of this study was to evaluate morphological and functional abnormalities by cerebral imaging in a series of systemic lupus erythematosus (SLE) patients with and without overt central nervous system (CNS) manifestations, and to detect possible relationships with clinical parameters and a large panel of autoantibodies, including those reactive against neurotypic and gliotypic antigens. 68 patients with SLE were investigated in a cross-sectional study which included clinical evaluation of symptoms, cerebral magnetic resonance imaging (MRI) and brain single photon emission tomography (SPECT) analysis, electroencephalography (EEG), and serological tests for antibodies directed against nuclear, cytoplasmic neuronal and glial cell-related antigens. The results of this study showed: (1) a significant positive association of (a) anti-glial fibrillary acidic protein (GFAP) serum antibodies with neuropsychiatric (NP) manifestations and (b) anti-serin proteinase 3 (anti-PR3/c-ANCA) serum antibodies with pathological cerebral SPECT; (2) the presence of significantly higher values of (a) SLICC organ damage index in patients with abnormal MRI and (b) SLAM activity index in patients with abnormal SPECT; and (3) the association of (a) abnormal MRI with nonactive NP manifestations and (b) combined abnormality of brain SPECT and MRI with the occurrence of overall overt NP manifestations and with those of the organic/major type. Neuropsychiatric manifestations, namely those of the organic/major type, appeared to be significantly associated to the presence of a serum antibody against GFAP, a gliotypic antigen. There was also evidence of an association between SPECT abnormality and the presence of anti-PR3 (c-ANCA). Furthermore, brain imaging by MRI and SPECT applied to SLE patients appears to express CNS involvement significantly related to specific categories of NP manifestations. The abnormalities detected by the two tests seem to be preferentially associated with different activity phases of the NP disorder or of the lupus disease.

Increased pulmonary epithelial permeability in systemic sclerosis is associated with enhanced cutaneous nerve growth factor expression.

Background: Nerve growth factor (NGF), a neurotrophic factor that indirectly induces fibroblast proliferation and collagen production, has been found to be increased in the affected dermis of patients with systemic sclerosis (SSc). To investigate the possibility of a relationship between cutaneous NGF production and pulmonary damage in SSc, we studied seven non-smoking scleroderma patients. Methods: Abnormalities in lung structure were assessed by radiological lung examination, and pulmonary epithelial permeability (PEP) was determined by ventilation lung scintigraphy. All patients underwent skin punch biopsy with NGF immunohistological staining. Results: A statistically significant correlation was found between the PEP values and the cutaneous NGF staining scores, which were markedly increased in all of the patients examined, irrespective of the age, disease duration, or radiologically defined lung abnormalities. Conclusion: These results support the hypothesis that functional and anatomical changes in SSc target organs may be determined by a local tissue hyperproduction of NGF.

Double phase parathyroid technetium-99m-MIBI scintigraphy to identify functional autonomy in secondary hyperparathyroidism.

UNLABELLED: Double-phase 99mTc-methoxyisobutylisonitrile (MIBI) parathyroid scintigraphy has been proposed to detect hyperplastic parathyroid tissue, but the clinical usefulness of this technique in secondary hyperparathyroidism is still debated. METHODS: Technetium-99m-MIBI parathyroid scintigraphy associated with parathyroid echography and [99mTc]pertechnetate thyroid scans were performed on 38 patients with chronic renal failure (CRF) and secondary hyperparathyroidism. In all patients, serum calcium, phosphorus, FT3, FT4, TSH, calcitonin and intact PTH (iPTH) were determined. Nine patients eventually underwent neck exploration and 28 parathyroid glands were removed. RESULTS: Thyroid diseases were excluded in all patients. Echography revealed parathyroid enlargement in 22/38 (58%) patients, while MIBI scintigraphy was positive in 28/38 (74%), including 5 ectopic glands. Mean serum iPTH concentration was significantly higher in MIBI-positive glands compared to MIBI-negative glands, but several discrepancies were observed in single patients. A significant positive correlation between serum iPTH and gland size was observed when MIBI-positive, but not MIBI-negative, parathyroids were considered. A paradoxical positive correlation between serum calcium and iPTH concentrations was found in MIBI-positive patients. CONCLUSION: Double-phase 99mTc-MIBI scintigraphy is positive in the majority of patients with uremic hyperparathyroidism. Comparison of scintigraphic data with morphological and functional data strongly suggests that 99mTc-MIBI scans do not reveal simple parathyroid enlargement but rather, identify the presence of hyperfunctioning (autonomous) parathyroid tissue suggestive of tertiary hyperparathyroidism.

Low environmental radiation background impairs biological defence of the yeast Saccharomyces cerevisiae to chemical radiomimetic agents.

Background radiation is likely to constitute one of the factors involved in biological evolution since radiations are able to affect biological processes. Therefore, it is possible to hypothesize that organisms are adapted to environmental background radiation and that this adaptation could increase their ability to respond to the harmful effects of ionizing radiations. In fact, adaptive responses to alkylating agents and to low doses of ionizing radiation have been found in many organisms. In order to test for effects of adaptation, cell susceptibility to treatments with high doses of radiomimetic chemical agents has been studied by growing them in a reduced environmental radiation background. The experiment has been performed by culturing yeast cells (Saccharomyces cerevisiae D7) in parallel in a standard background environment and in the underground Gran Sasso National Laboratory, with reduced environmental background radiation. After a conditioning period, yeast cells were exposed to recombinogenic doses of methyl methanesulfonate. The yeast cells grown in the Gran Sasso Laboratory showed a higher frequency of radiomimetic induced recombination as compared to those grown in the standard environment. This suggests that environmental radiation may act as a conditioning agent.

Tracheo-bronchial mucociliary clearance in patients with primary and secondary Sjögren's syndrome.

We determined the tracheo-bronchial mucociliary clearance (MCC) in order to evaluate a possible impairment of this function in patients affected by Sjögren's syndrome (SS) with or without overt clinical symptoms of xerotrachea. The MCC was expressed as flow rate (mm/min) and studied in 22 non-smoking SS patients (10 pSS and 12 sSS) and in 8 control subjects by specifically adapted ventilation lung scintigraphy (VLS). The MCC in the control group was 5.9 +/- 1.1 mm/min. No values were produced for MCC in 16 SS patients (8 pSS and 8 sSS) in the time interval considered and were reduced in the remaining 6 SS patients (3.3 +/- 1.2 mm/min). In all nine cases with clinical evidence of xerotrachea no values for MCC were obtained. A significant correlation was found between the MCC values and the rate of stimulated salivary excretion determined by dynamic scialoscintigraphy in the same patients (p < 0.001). These preliminary data show that the majority of SS patients studied presented with MCC impairment, always found when clinical symptoms of xerotrachea were present.

[Diagnosis of hepatic hemangioma with simplified double 99mTc labelling]. / La diagnosi di emangioma epatico mediante doppia marcatura semplificata con 99mTc.

The authors report on their experience with liver hemangioma (LH) diagnosis by means of a simplified method--that is, the simultaneous, in vivo, double labelling of liver reticuloendothelial system (RES) and of red blood cells (RBC) by 99mTc. Twenty-eight patients with US diagnosis of suspected LH and 15 controls were examined after sequential iv injection of SnCl2, of 99mTc-mucolloid albumin and, after liver scintigraphy, of 99mTc-pertechnetate to conclude in vivo RBC labelling. All patients underwent CT and, if necessary, CT-guided biopsy. Focal colloid defects filled after RBC labelling were shown in 20/22 patients with unquestionable LH. No colloid defects were shown in 6/28 cases (expansive process). 15/15 controls showed unchanged non-filling defects after double labelling. Finally, the authors point out that, in the diagnosis of LH, sequential double labelling of liver RES and RBC appears to be a quicker scintigraphic technique than conventional ones. Moreover, this technique has the same high specificity and sensitivity as more time-consuming ones.

Simultaneous 99mTc double labelling of the hepatic reticuloendothelial system and of the red blood cells: a simplified method for the detection of liver hemangiomas.

Sonographic images of liver hemangioma are not specific. Causal detection imposes further investigations (angiography, CT, NMR) which are not always practicable. 99mTc-red blood cells study after 99mTc colloid liver scintigraphy has been already proposed. Ten patients with hepatic hemangiomas were evaluated by simplified, simultaneous in vivo double labelling of the reticuloendothelial system and red blood cells by means of successive i.v. injections of SnCl2, 99mTc colloid albumin and 99mTc-pertechnetate. Focal colloid defects filled with the labelled RBC were revealed in 9/10 liver hemangiomas. Angioscintigraphy showed decreased perfusion and RBC scintigraphy an increased blood volume in the focal colloid defects due to the hemangiomas.

[Gastric transit of a radiolabelled liquid meal in a group of patients with insulin-dependent diabetes mellitus]. / Studio del transito gastrico di un pasto liquido radiomarcato in un gruppo di pazienti affetti da diabete mellito insulino-dipendente.

The functional alterations in the digestive tract observable during diabetes mellitus are frequent albeit often asymptomatic. They affect several different districts and are still not clearly defined aetiopathogenetically. It was therefore decided to evaluate the gastric transit times of a balanced liquid meal labelled with 99-Tc-colloidal sulphide in a group of patients suffering from insulin-dependent diabetes and in a group of 10 controls. The anatomical integrity of the oesophago-gastro-duodenal tract has been evaluated by endoscopy and histology. Transit times (T/2) proved significantly increased in diabetics (92.38 +/- 33.397 minutes) compared to the controls (48.63 +/- 16.423 minutes), p 0.001. No correlation was observed between gastric transit times, duration of the diabetic disease, degree of glyco-metabolic compensation and presence of autonomous neuropathy.

Long-term follow-up of technetium articular index in rheumatoid arthritis patients during oral chrysotherapy: evidence of paradoxical behaviour.

The Technetium Articular Index (TcAI) is regarded as a parameter of local inflammation in rheumatoid arthritis (RA). We studied TcAI behaviour during 1-year chrysotherapy in a group of fifteen RA patients. In non-responders TcAI showed a gradual decrease up to the 6th month and a return to baseline values within the second semester of the follow-up; conversely, in response patients TcAI remained unchanged during the entire period of the study, thus showing a paradoxical behaviour probably depending on the recovery of normal physical ability and articular activity.