Vaginal temperature of lactating cows during heat waves or normal summer day and effect of additional daily cooling treatments as heat load mitigation strategy.

The vaginal temperature (VT) of lactating Holstein cows was monitored in not heat wave (NHW) and in heat wave (HW) summer days. Temperature humidity index (THI) was monitored and assigned to four classes of heat load (HL): THI < 68 null; 68 < THI < 74 low; 74 < THI < 80 moderate; and THI > 80 high.Five daily treatments consisting of continuous forced ventilation and sprayed water (1' on follow by 5' off) were assumed as control cooling protocol (CC) and compared with two experimental cooling protocols (EC) applied in the feed bunk and based on the CC plus two additional cooling treatments which lasted a total of 90' (EC90) or 150' (EC150) in the day.Sixty lactating cows were enrolled in two summer trials carried out in NHW or HW. In each trial, 10 cows were cooled by CC, 10 by EC90 and 10 by EC150. Twenty additional cows were monitored in a fall trail to have reference value of THI and VT under thermoneutral conditions (TN). Each trial lasted 72 h, and measurements of VT were carried out by intra-vaginal data loggers.The 33% of observed THI was within the high class of HL during HW, whereas THI never exceeded the upper threshold of moderate or low class of HL in NHW and TN, respectively.Multiparous and high yielding cows were more sensitive to HL, and the increased daily cooling treatments reduced heat load during hot conditions. However, during heat waves a certain degree of hyperthermia occurred even with intensive cooling management based on seven daily treatments.

Clinical impact of high platelet reactivity in patients with atrial fibrillation and concomitant percutaneous coronary intervention on dual or triple antithrombotic therapy.

High platelet reactivity (HPR) on clopidogrel is an established thrombotic risk factor after percutaneous coronary intervention (PCI). The introduction of more potent antiplatelet drugs has partially surpassed this issue. However, in the setting of concomitant atrial fibrillation (AF) and PCI clopidogrel is still the most adopted P2Y12 inhibitor. In the present study all consecutive patients with history of AF discharged from our cardiology ward with dual (DAT) or triple (TAT) antithrombotic therapy after a PCI from April 2018 to March 2021 were enrolled in an observational registry. For all subjects, blood serum samples were collected and tested for platelet reactivity by arachidonic acid and ADP (VerifyNow system) and genotyping of the CYP2C19*2 loss-of-function polymorphism. We recorded at 3 and 12-months follow-up: (1) major adverse cardiac and cerebrovascular events (MACCE), (2) major hemorrhagic or clinically relevant non-major bleeding and (3) all-cause mortality. A total of 147 patients were included (91, 62% on TAT). In 93.4% of patients, clopidogrel was chosen as P2Y12 inhibitor. P2Y12 dependent HPR resulted an independent predictor of MACCE both at 3 and 12 months (HR 2.93, 95% C.I. 1.03 to 7.56, p = 0.027 and HR 1.67, 95% C.I. 1.20 to 2.34, p = 0.003, respectively). At 3-months follow-up the presence of CYP2C19*2 polymorphism was independently associated with MACCE (HR 5.21, 95% C.I. 1.03 to 26.28, p = 0.045). In conclusion, in a real-world unselected population on TAT or DAT, the entity of platelet inhibition on P2Y12 inhibitor is a potent predictor of thrombotic risk, suggesting the clinical utility of this laboratory evaluation for a tailored antithrombotic therapy in this high-risk clinical scenario. The present analysis was performed in patients with AF undergoing PCI on dual or triple antithrombotic therapy. At 1 year follow-up MACCE incidence was consistent, and it was not different in different antithrombotic pattern groups. P2Y12 dependent HPR was a potent independent predictor of MACCE both at 3- and 12-months follow-up. In the first 3 months after stenting the carriage of CYP2C19*2 allele was similarly associated with MACCE. Abbreviation: DAT, dual antithrombotic therapy; HPR, high platelet reactivity; MACCE, major adverse cardiac and cerebrovascular events; PRU, P2Y12 reactive unit; TAT, triple antithrombotic therapy. Created with BioRender.com.

Energy transfer upon collision of selectively excited CO2 molecules: State-to-state cross sections and probabilities for modeling of atmospheres and gaseous flows.

Carbon dioxide molecules can store and release tens of kcal/mol upon collisions, and such an energy transfer strongly influences the energy disposal and the chemical processes in gases under the extreme conditions typical of plasmas and hypersonic flows. Moreover, the energy transfer involving CO2 characterizes the global dynamics of the Earth-atmosphere system and the energy balance of other planetary atmospheres. Contemporary developments in kinetic modeling of gaseous mixtures are connected to progress in the description of the energy transfer, and, in particular, the attempts to include non-equilibrium effects require to consider state-specific energy exchanges. A systematic study of the state-to-state vibrational energy transfer in CO2 + CO2 collisions is the focus of the present work, aided by a theoretical and computational tool based on quasiclassical trajectory simulations and an accurate full-dimension model of the intermolecular interactions. In this model, the accuracy of the description of the intermolecular forces (that determine the probability of energy transfer in molecular collisions) is enhanced by explicit account of the specific effects of the distortion of the CO2 structure due to vibrations. Results show that these effects are important for the energy transfer probabilities. Moreover, the role of rotational and vibrational degrees of freedom is found to be dominant in the energy exchange, while the average contribution of translations, under the temperature and energy conditions considered, is negligible. Remarkable is the fact that the intramolecular energy transfer only involves stretching and bending, unless one of the colliding molecules has an initial symmetric stretching quantum number greater than a threshold value estimated to be equal to 7.

Juvenile paradental cyst: presentation of a rare case involving second molar.

The aim of this article was to describe a rare case of paradental cyst of the permanent mandibular second molar. A 14-year-old girl was referred to Oral Surgery Department, Dental Clinic, IRCSS Fondazione Ca' Granda, University of Milan, Italy, for the evaluation of the deep probing located on the buccal aspect of her erupted mandibular left second molar. Clinical signs of inflammation were absent and the mucosa around the second molar appeared clinically normal. Pulp tests for the second molar were positive. The evaluation of the panoramic radiograph did not revealed radiolucency. The Cone-beam tomography showed a well-defined semilunar-shaped radiolucency demarcated by a fine radiopaque line. The cyst was enucleated. The histopathologic analisys revealed the presence of hyperplastic, non-keratinized squamous epithelium with heavy, dense inflammatory cell infiltrate in the epitelium and connective tissue wall. This analysis associated with macroscopic, clinical and radiografic examination confirmed the diagnosis of paradental cyst. A clinic-pathologic correlation, incorporating the surgical, radiographic and histologic findings, is required to obtain the final diagnosis of paradental cyst. Today, the treatment of choice is simple enucleation and thorough curettage of the cyst without extraction of the involved tooth, but if CT demonstrates erosions in the buccal or lingual cortices, marsupialization should be the treatment of choice.

Needs and challenges of daily life for people with Down syndrome residing in the city of Rome, Italy.

BACKGROUND: Population-based surveys on the quality of life of people with Down syndrome (DS) are difficult to perform because of ethical and legal policies regarding privacy and confidential information, but they are essential for service planning. Little is known about the sample size and variability of quality of life of people with DS living in the city of Rome, which has a population of 2.7 million inhabitants. The aim of the present study is to explore the needs and challenges in health, social integration and daily life, of people with DS living in Rome. METHODOLOGY: A cross-sectional, census-based survey was conducted in 2006. All family doctors (3016 in total) of the National Health Service were involved by the Statistical Bureau of the Municipality of Rome. As per the census, every resident citizen is registered with a family doctor and every person with disabilities is coded. Associations for Down Syndrome encouraged their members to participate in the research. Questionnaires were completed by families of people with DS, in accordance with privacy laws. FINDINGS: An initial survey, conducted via a letter and a telephone contact with family doctors, identified 884 people with DS residing in the city of Rome. Data on the medical and social conditions of 518 people with DS, ranging in age from 0 to 64 years, were collected. Some 88% of these were living with their original family; 82.1% had one or more siblings, and 19.5% had lost one or both parents. A full 100% of children with DS were enrolled in the public school system. This ensures that they are fully occupied and entirely integrated in society. After secondary school there is a lack of opportunities. Thus, only 10% of adults were working with a regular contract. A mere 42.2% of people with DS aged 25-30 were involved in some form of regular activity (although not always on a daily basis). After the age of 30, the percentage of people demonstrating decline in function increased sharply, while disability-related support decreased. In other words, as people with DS age, daily life evolves increasingly around the home, with only occasional outdoor activities. CONCLUSION: The health, employment and social needs of the majority of people with DS in the city of Rome are not being met. The findings of this study underscore the urgent need for more comprehensive inclusion in society of adults with DS and for the provision of support services to create an enabling environment for inclusion. Because of the variability of performance among individuals with DS, there is a need to create more case-specific options in terms of work, living arrangements, social networking and medical services. Schooling and social inclusion in childhood alone do not guarantee a satisfactory quality of life in adulthood. It is argued herewith that policy of inclusion and support should extend over the entire lifetime of people with DS.

Functional infrared imaging of paroxysmal ischemic events in patients with Raynaud's phenomenon.

The use of thermal infrared (IR) imaging together with the study of the thermal recovery from a controlled cold challenge has been proposed in the diagnosis and follow-up of therapeutic response of Raynaud's Phenomenon (RP) and Systemic Sclerosis (SSc). The controlled cold challenge test usually performed during IR investigations may induce a RP in patients with the latter condition. In our Institution we routinely perform capillaroscopy and thermal IR to follow-up SSc patients. In this paper, we describe the thermal recovery patterns shown by two SSc patients (a 40 year-old male with diffuse variant of SSc and a 71 year-old female with a limited variant of SSc) who presented ischemic and paroxysmal RP attack while recovering from the routine controlled cold challenge test. During RP attack, the cutaneous temperature of some fingers continued to decrease for some minutes even after the cessation of the cold stress. To the best of our knowledge, to date, no literature report has documented the thermal behaviour of SSc patients' fingers which occasionally present ischemic and paroxysmal response. Triggering of ischemic RP attack appears to not rely only on morphological and structural finger impairment, but also upon other aspects, like the emotional attitude of the subject and the possible discomfort experienced with the proceeding of the functional cold stress test.

Paradental cyst of the first molar: a report of two cases.

OBJECTIVE: The paradental cyst is an uncommon lesion associated with the permanent mandibular first or second molar in children just prior to tooth eruption. The purpose of this article is to present two cases of paradental cyst affecting the buccal aspect of permanent mandibular first molar of both young patients. We also discuss diagnosis, treatment and radiographic findings of the cases. PATIENTS AND METHODS: In both cases was made only the enucleation of cyst without extraction of the adjacent tooth. Lesional samples were sent for histopathologic analysis. RESULTS: The histopathologic analysis of both cases, revealed a lining of hyperplastic, nonkeratinized squamous epithelium with heavy, dense inflammatory cell infiltrate in the epithelium and connective tissue wall. The histopathology associated with macroscopic and radiographic examination permitted the definitive diagnosis of a paradental cyst on the mandibular left first molar. A follow-up of 1 year was carried out in both cases and no recurrences was noted; in the first case was observed the correct eruption of the mandibular permanent left first molar. CONCLUSIONS: A clinicopathologic correlation, incorporating the surgical, radiographic, and histological finding, is required to obtain the final diagnosis of paradental cyst. Today, the treatment of choice is simple enucleation and thorough curettage of the cyst without extraction of the involved tooth.

Multidisciplinary approach to obesity.

UNLABELLED: Obesity, associated with morbidity and mortality, is a complex disorder, characterised by an increase in fat mass (FM). Most authors agree in considering essential an integrated treatment made up of nutritional intervention, physical reconditioning programme and cognitive-behavioural psychotherapy. However, the feasibility is problematic and data in literature confirming the validity of this approach are poor. AIM: To verify the efficacy of a multidimensional approach (Nutritional Psycho-Physical Reconditioning - NPPR) in obesity treatment. METHODS: All patients admitted from June 2002 to June 2004 (464 subjects) ranged from 18 to 65 years old, with a body mass index (BMI) >30 kg/m2 were included in the programme. After the nutritional status evaluation a standard dietetic treatment (group N) or an integrated and multidisciplinary obesity treatment (group NPPR) was proposed. RESULTS: In group NPPR treatment duration was significantly higher (142.6+/-26 vs 48.6+/-55 days - p=0.000), while the drop-out amount was definitely lower (5.5 vs 54.4%; p=0.000). Weight loss compared to the initial weight and the difference between initial and final FM resulted significantly higher in group NNPR. Subjects in NPPR obtained a higher increase in the distance covered in a 6-minute walk test (59.9+/-19 vs 40.5+/-17 m; p=0.04) and in muscular strength. State and trait anxiety, mood and quality of life scores improved in NPPR subjects while remained substantially stable in group N. CONCLUSIONS: An integrated approach to obesity is the way to be pursued in order to obtain important and at least short-term results.

Chromosome inter- and intrachanges detected by arm-specific DNA probes in the progeny of human lymphocytes exposed to energetic heavy ions.

We measured residual cytogenetic damage in the progeny of human peripheral blood lymphocytes exposed to 1 GeV/ nucleon iron ions or gamma rays. Arm-specific DNA probes for chromosome 1 were used to detect aberrations as a function of dose in cells harvested 144 h after exposure. In addition, arm-specific mFISH was applied to samples exposed to a single dose of 2 Gy. These methods allowed the detection of interarm intrachanges (pericentric inversions) in addition to interchanges. The ratio of these types of aberrations (F ratio) has been proposed as a fingerprint of exposure to densely ionizing radiation. The fractions of aberrant cells in the progeny of cells exposed to iron ions were similar to those in the population exposed to gamma rays, possibly because many rearrangements induced by heavy ions ultimately lead to cell death. Simple inter- and intrachanges were also similar, but more complex rearrangements were found in cells that survived after exposure to iron ions. We did not find a significant difference in the ratio of simple interchanges to simple intrachanges for the two radiation types. However, iron ions induced a much higher frequency of events involving both inter- and intrachanges. We conclude that these complex rearrangements represent a hallmark of exposure to heavy ions and may be responsible of the decrease of the F ratio with increasing LET reported in the literature in some in vitro and in vivo experiments.

Effects of modulated microwave radiation at cellular telephone frequency (1.95 GHz) on X-ray-induced chromosome aberrations in human lymphocytes in vitro.

The case for a DNA-damaging action produced by radiofrequency (RF) signals remains controversial despite extensive research. With the advent of the Universal Mobile Telecommunication System (UMTS) the number of RF-radiation-exposed individuals is likely to escalate. Since the epigenetic effects of RF radiation are poorly understood and since the potential modifications of repair efficiency after exposure to known cytotoxic agents such as ionizing radiation have been investigated infrequently thus far, we studied the influence of UMTS exposure on the yield of chromosome aberrations induced by X rays. Human peripheral blood lymphocytes were exposed in vitro to a UMTS signal (frequency carrier of 1.95 GHz) for 24 h at 0.5 and 2.0 W/kg specific absorption rate (SAR) using a previously characterized waveguide system. The frequency of chromosome aberrations was measured on metaphase spreads from cells given 4 Gy of X rays immediately before RF radiation or sham exposures by fluorescence in situ hybridization. Unirradiated controls were RF-radiation- or sham-exposed. No significant variations due to the UMTS exposure were found in the fraction of aberrant cells. However, the frequency of exchanges per cell was affected by the SAR, showing a small but statistically significant increase of 0.11 exchange per cell compared to 0 W/kg SAR. We conclude that, although the 1.95 GHz signal (UMTS modulated) does not exacerbate the yield of aberrant cells caused by ionizing radiation, the overall burden of X-ray-induced chromosomal damage per cell in first-mitosis lymphocytes may be enhanced at 2.0 W/kg SAR. Hence the SAR may either influence the repair of X-ray-induced DNA breaks or alter the cell death pathways of the damage response.

Accelerator-based tests of radiation shielding properties of materials used in human space infrastructures.

Shielding is the only practical countermeasure for the exposure to cosmic radiation during space travel. It is well known that light, hydrogenated materials, such as water and polyethylene, provide the best shielding against space radiation. Kevlar and Nextel are two materials of great interest for spacecraft shielding because of their known ability to protect human space infrastructures from meteoroids and debris. We measured the response to simulated heavy-ion cosmic radiation of these shielding materials and compared it to polyethylene, Lucite (PMMA), and aluminum. As proxy to galactic nuclei we used 1 GeV n iron or titanium ions. Both physics and biology tests were performed. The results show that Kevlar, which is rich in carbon atoms (about 50% in number), is an excellent space radiation shielding material. Physics tests show that its effectiveness is close (80-90%) to that of polyethylene, and biology data suggest that it can reduce the chromosomal damage more efficiently than PMMA. Nextel is less efficient as a radiation shield, and the expected reduction on dose is roughly half that provided by the same mass of polyethylene. Both Kevlar and Nextel are more effective than aluminum in the attenuation of heavy-ion dose.

The efficacy of a porcine collagen matrix in keratinized tissue augmentation: a 5-year follow-up study.

BACKGROUND: When keratinized tissue width around dental implants is poorly represented, the clinician could resort to autogenous soft tissue grafting. Autogenous soft tissue grafting procedures are usually associated with a certain degree of morbidity. Collagen matrices could be used as an alternative to reduce morbidity and intra-operatory times. The aim of this study was to assess the efficacy of a xenogeneic collagen matrix as a substitute for soft tissue grafting around dental implants. METHODS: Fifteen consecutive patients underwent a vestibuloplasty and keratinized tissue reconstruction around dental implants, both in the mandible and the maxilla, with a porcine collagen matrix. The so obtained keratinized tissues were measured and evaluated after 6 months and 1, 4, and 5 years. RESULTS: The average gain of keratinized tissue was 5.7 mm. After 6 months, it was observed a resorption of 37%, after 1 year 48%, and after 5 years 59%. The mean gain of keratinized tissue after 5 years was 2.4 mm. Hemostatic effect and post-operative pain were evaluated too. All subjects referred minimal pain with no bleeding. No adverse reaction nor infection was noted. CONCLUSIONS: The present study showed the efficacy of a porcine collagen matrix in keratinized tissue augmentation. The possibility to use a soft tissue substitute is a great achievement as morbidity decreases and bigger areas can be treated in a single surgery.

Clinical features and outcomes of hepatocellular carcinoma in Caucasian cirrhotic patients on long-term analogue therapy for hepatitis B.

BACKGROUND: Long-term oral nucleos(t)ide analogue (NUC) therapy in hepatitis B virus (HBV)-related compensated cirrhotics prevents clinical decompensation but not hepatocellular carcinoma (HCC) development. AIMS: To define the clinical features and outcomes of HCC in long-term NUC-treated HBV patients. METHODS: All HCCs developing between 2005 and 2016 in NUC-treated HBV patients under surveillance were studied, excluding those that occurred within the first 6 months of therapy. Clinical features of HCC, alpha faetoprotein (AFP) patterns and patients' outcome were studied. RESULTS: Seventy-six HCC patients were included. Median age was 67 (40-83) years, 84% males, 96% Caucasian, 95% HBeAg-negative, 96% with undetectable HBV DNA, 83% with normal ALT levels, and 92% with compensated cirrhosis. Median serum AFP levels were 4 (1-3615) ng/mL (>7 ng/mL in 36%). HCC was monofocal in 78%, had a median diameter of 20 (6-57) mm and was in its early stage in 92% which allowed potentially curative treatments in 78% (39% ablation, 28% surgical resection, 11% liver transplantation). Overall, a complete response was obtained in 61 (80%) patients: in 40 after a first-line treatment, in 3 after the second-line treatment, in 2 after the third-line treatment, while 16 underwent liver transplantation (8 as second line). During 45 (7-144) months after HCC diagnosis, 19 patients died, 84% from HCC progression. The median time to recurrence was 20.2 (3-53) months, and the cumulative 5-year liver-related survival was 74%. CONCLUSIONS: HCCs developing in patients under long-term NUC treatment were single, small tumours, amenable to curative therapies able to confer excellent 5-year survival rates.

High concentrations of catecholamines in human hypothalamic-hypophysial blood.

While the hypothalamic-hypophysial portal system has been extensively studied in laboratory animals, equivalent studies have not been performed in humans. Here, we present an experimental procedure for collecting suprapituitary blood in man. To solve the question on the origin of such blood we investigated specific markers of hypothalamic secretory activity: the catecholamines (CAs). We found (a) norepinephrine (NE), dopamine (DA), and epinephrine (E) concentrations from approximately 1.5 to 2.5, 3.5 to 4.5, and 6- to 10-fold higher, respectively, in suprapituitary than peripheral blood, (b) different NE/DA and NE/E ratios in favor of DA and E in suprapituitary blood, and (c), a complete (100%) group separation (suprapituitary vs. peripheral) when discriminant analysis included only DA and E. These data indicate that suprapituitary blood composition is different from that of the peripheral blood, and is particularly rich in CAs and claimed differences between DA and E release on one hand and NE release on the other in suprapituitary blood also are observed. We advance the hypothesis of a hypothalamic source of such amines draining via median eminence into portal vasculature, and name this blood "hypothalamic-hypophysial blood." Besides serving as "classical" neurotransmitters, CAs may also have a direct neurohormonal role in the regulation of the human hypothalamic-hypophysial function.

Review article: the potential of interferon and nucleos(t)ide analogue combination therapy in chronic hepatitis B infection.

BACKGROUND: A short-term course of pegylated-interferon (Peg-IFN), or a long-term treatment with a third generation nucleot(s)ide analogue (NUC), of chronic hepatitis B (CHB) infection achieves viral suppression and may prevent disease progression. Owing to different mechanisms of action of the two regimens, a Peg-IFN and NUC combination treatment may be an attractive approach to enhance the off-treatment rates of virological and serological response. AIM: To review the literature on combinations of Peg-IFN plus NUC, including the simultaneous initiation of Peg-IFN and NUC in naïve patients; an 'add-on' combination, where Peg-IFN is started at variable times after the beginning of NUC; or a 'switch-to' strategy usually from NUC to Peg-IFN. METHODS: We performed a PubMed literature search using the following terms individually or in combination: NUC, hepatitis B virus, chronic hepatitis, interferon, pegylated-interferon, nucleos(t)ide analogues, entecavir, tenofovir. English-language articles published up to December 2015, as well as conference proceedings from international meetings were reviewed. References from selected papers were reviewed and used if relevant. RESULTS: While combination and NUC pre-treatment failed to increase HBsAg clearance rates, more promising results were achieved in patients under long-term effective NUC therapy. CONCLUSION: While Peg-IFN and nucleos(t)ide analogue combination therapy should not be recommended currently, the addition of or the switch to Peg-IFN in nucleos(t)ide analogue-treated patients with chronic hepatitis B infection may be useful option.

Members of the Amy-2 alpha-amylase gene family of mouse strain CE/J contain duplicated 5' termini.

Several members of the Amy-2 alpha-amylase multigene family from the CE/J strain of mouse have been cloned in cosmid vectors. Structural analysis of these recombinants reveals that the cloned Amy-2 copies contain tandem 5' termini. The duplicated 5'-terminal elements, which lie upstream from the Amy-2 cap site, are separated from their Amy-2 homologues by about 8000 bases. The orientation of these 5' orphons is the same as that of Amy-2. Gene titration and cloning experiments suggest that at least four of the approximately 15 Amy-2 copies present in the CE/J genome contain 5' orphon elements. The extent of sequence homology between 5' orphons and their gene homologues has been determined by DNA sequence analysis. All the orphons are identical and contain the entire 185 base-pairs of the first exon, 49 base-pairs of the first intron and more than 400 base-pairs of the Amy-2 5' flanking region. Intron and flanking-region sequences of the orphons differ by about 20% from their Amy-2 counterparts, and the exon by about 8%. The TATA box and the cap site are conserved, while the ATG translation initiation signal is mutated to ATA in the orphon. No transcription initiation has been detected at the orphon cap site using run-off transcription in isolated pancreatic nuclei in vitro.

Cytogenetic effects of high-energy iron ions: dependence on shielding thickness and material.

We report results for chromosomal aberrations in human peripheral blood lymphocytes after they were exposed to high-energy iron ions with or without shielding at the HIMAC, AGS and NSRL accelerators. Isolated lymphocytes were exposed to iron ions with energies between 200 and 5000 MeV/nucleon in the 0.1-1-Gy dose range. Shielding materials consisted of polyethylene, lucite (PMMA), carbon, aluminum and lead, with mass thickness ranging from 2 to 30 g/cm2. After exposure, lymphocytes were stimulated to grow in vitro, and chromosomes were prematurely condensed using a phosphatase inhibitor (calyculin A). Aberrations were scored using FISH painting. The yield of total interchromosomal exchanges (including dicentrics, translocations and complex rearrangements) increased linearly with dose or fluence in the range studied. Shielding decreased the effectiveness per unit dose of iron ions. The highest RBE value was measured with the 1 GeV/nucleon iron-ion beam at NSRL. However, the RBE for the induction of aberrations apparently is not well correlated with the mean LET. When shielding thickness was increased, the frequency of aberrations per particle incident on the shield increased for the 500 MeV/nucleon ions and decreased for the 1 GeV/nucleon ions. Maximum variation at equal mass thickness was obtained with light materials (polyethylene, carbon or PMMA). Variations in the yield of chromosomal aberrations per iron particle incident on the shield follow variations in the dose per incident particle behind the shield but can be modified by the different RBE of the mixed radiation field produced by nuclear fragmentation. The results suggest that shielding design models should be benchmarked using both physics and biological data.

Modelled microgravity does not modify the yield of chromosome aberrations induced by high-energy protons in human lymphocytes.

The aim was to evaluate the effect of modelled microgravity on radiation-induced chromosome aberrations (CAs). G0 peripheral blood lymphocytes were exposed to 60 MeV protons or 250 kVp X-rays in the dose range 0-6 Gy, and allowed to repair DNA damage for 24 h under either normal gravity or microgravity modelled by the NASA-designed rotating-wall bioreactor. Cells were then stimulated to proliferate by phytohaemagglutinin (PHA) under normal gravity conditions and prematurely condensed chromosomes were harvested after 48 h. CAs were scored in chromosomes 1 and 2 by fluorescence in-situ hybridization. Proliferation gravisensitivity was examined by cell growth curves and by morphological evaluation of mitogen-induced activation. Cell replication rounds were monitored by bromodeoxyuridine labelling. Modelled microgravity markedly reduced PHA-mediated lymphocyte blastogenesis and cell growth. However, no significant differences between normal gravity and modelled microgravity were found in the dose-response curves for the induction of aberrant cells or total interchromosomal exchange frequency. Rotating-wall bioreactor-based microgravity reproduced space-related alterations of mitogen stimulation in human lymphocytes but did not affect the yield of CAs induced by low-linear energy transfer radiation.

Fragmentation studies of relativistic iron ions using plastic nuclear track detectors.

We measured fluence and fragmentation of high-energy (1 or 5 A GeV) 56Fe ions accelerated at the Alternating Gradient Synchrotron or at the NASA Space Radiation Laboratory (Brookhaven National Laboratory, NY, USA) using solid-state CR-39 nuclear track detectors. Different targets (polyethylene, PMMA, C, Al, Pb) were used to produce a large spectrum of charged fragments. CR-39 plastics were exposed both in front and behind the shielding block (thickness ranging from 5 to 30 g/cm2) at a normal incidence and low fluence. The radiation dose deposited by surviving Fe ions and charged fragments was measured behind the shield using an ionization chamber. The distribution of the measured track size was exploited to distinguish the primary 56Fe ions tracks from the lighter fragments. Measurements of projectile's fluence in front of the shield were used to determine the dose per incident particle behind the block. Simultaneous measurements of primary 56Fe ion tracks in front and behind the shield were used to evaluate the fraction of surviving iron projectiles and the total charge-changing fragmentation cross-section. These physical measurements will be used to characterize the beam used in parallel biological experiments.

Long-term survival rate of implants placed in conjunction with 246 sinus floor elevation procedures: results of a 15-year retrospective study.

OBJECTIVES: The aim of the present long-term study was to retrospectively evaluate the survival rate of implants placed in regenerated maxillary sinuses and to assess the influence of hypothetical predictors of implant failure. METHODS: A database including 218 patients who received dental implants after sinus lift procedures was analyzed. The following variables were systematically included and evaluated: type of graft material used, number of surgeries performed, and use of membranes to cover the lateral antrostomy and/or to repair accidental Schneiderian membrane perforations. The Kaplan-Meier estimator was used for comparisons among the groups. RESULTS: A total of 589 dental implants were positioned in 246 grafted sinuses and were in function for 3-186 months. The Kaplan-Meier cumulative survival rate was 98.3% after 15.5 years of follow-up. All implant losses occurred within 52 months (4.3 years) after augmentation. According to the log-rank test, no statistically significant difference was shown between each patient/implant variable (p>0.05). CONCLUSIONS: Despite the limitations inherent in this type of study, no statistically significant differences between the groups could be found. Intraoperative Schneiderian membrane perforations did not affect the outcome of the implants positioned. CLINICAL SIGNIFICANCE: The present long-term study is intended as a reference for clinicians approaching sinus floor elevation surgery in order to provide them with relevant operative findings. Since all the drawbacks occurred within the first 5 years, medium-term follow-up studies could be suitable for further retrospective evaluations.