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Biomedical subjects

P Carlson

Publications and source records attributed to P Carlson.

At least 19 recordsLinked to original sources
PubMed2005

All-ceramic fixed partial dentures designed according to the DC-Zirkon technique. A 2-year clinical study.

The aim of the study was to investigate whether the properties of a pre-sintered, hot isostatic post-compacted (HIP) ZrO2 are adequate for use in three-five-unit fixed partial dentures (FPDs) and to evaluate the clinical results. Twenty three-five-unit FPDs were fabricated for 18 patients on a total of 56 abutments. They were all made on abutments cut with a shoulder preparation and cemented with a zinc phosphate cement. They were clinically followed for 24 months. After 24 months all FPDs were still in use without any fractures or clinical wear but in three cases (15%) minor chip-of fractures were observed. Marginal integrity was rated excellent at 45 abutments and acceptable at 11. Within the limitations of this 2-year clinical follow-up study, FPDs made of pre-sintered HIP ZrO2 core material veneered with a compatible ceramic is an acceptable alternative in the fabrication of FPDs with the extensions investigated in this study. Special attention, however, must be paid to designing the core for an occlusal shape that provides sufficient support for the veneer.

Adult↗
PubMed2004

The ALTEA/ALTEINO projects: studying functional effects of microgravity and cosmic radiation.

The ALTEA project investigates the risks of functional brain damage induced by particle radiation in space. A modular facility (the ALTEA facility) is being implemented and will be operated in the International Space Station (ISS) to record electrophysiological and behavioral descriptors of brain function and to monitor their time dynamics and correlation with particles and space environment. The focus of the program will be on abnormal visual perceptions (often reported as "light flashes" by astronauts) and the impact on retinal and brain visual structures of particle in microgravity conditions. The facility will be made available to the international scientific community for human neurophysiological, electrophysiological and psychophysics experiments, studies on particle fluxes, and dosimetry. A precursor of ALTEA (the 'Alteino' project) helps set the experimental baseline for the ALTEA experiments, while providing novel information on the radiation environment onboard the ISS and on the brain electrophysiology of the astronauts during orbital flights. Alteino was flown to the ISS on the Soyuz TM34 as part of mission Marco Polo. Controlled ground experiments using mice and accelerator beams complete the experimental strategy of ALTEA. We present here the status of progress of the ALTEA project and preliminary results of the Alteino study on brain dynamics, particle fluxes and abnormal visual perceptions.

Brain↗
PubMed2003

Study of the radiation environment on MIR space station with SILEYE-2 experiment.

In this work we present preliminary results of nuclear composition measurements on board space station MIR obtained with SILEYE-2 particle telescope. SILEYE-2 was placed on MIR in 1997 and has been working since then. It consists of an array of 6 active silicon strip detectors which allow nuclear and energetic identification of cosmic rays in the energy range between approximately 30 and 200 MeV/n. The device is attached to an helmet and connected to an eye mask which shields the cosmonaut eyes from light and allow studies of the Light Flashes (LF) phenomenon. In addition to the study of the causes of LF, the device is used to perform real time long term radiation environment monitoring inside the MIR, performing measurements in solar quiet and active days.

Cosmic Radiation↗
PubMed2003

ALTEA: anomalous long term effects in astronauts. A probe on the influence of cosmic radiation and microgravity on the central nervous system during long flights.

The ALTEA project participates to the quest for increasing the safety of manned space flights. It addresses the problems related to possible functional damage to neural cells and circuits due to particle radiation in space environment. Specifically it aims at studying the functionality of the astronauts' Central Nervous Systems (CNS) during long space flights and relating it to the peculiar environments in space, with a particular focus on the particle flux impinging in the head. The project is a large international and multidisciplinary collaboration. Competences in particle physics, neurophysiology, psychophysiology, electronics, space environment, data analyses will work together to construct the fully integrated vision electrophysiology and particle analyser system which is the core device of the project: an helmet-shaped multi-sensor device that will measure concurrently the dynamics of the functional status of the visual system and passage of each particle through the brain within a pre-determined energy window. ALTEA is scheduled to fly in the International Space Station in late 2002. One part of the multi-sensor device, one of the advanced silicon telescopes, will be launched in the ISS in early 2002 and serve as test for the final device and as discriminating dosimeter for the particle fluences within the ISS.

Adaptation, Physiological↗
PubMed2002

Eye light flashes on the Mir space station.

The phenomenon of light flashes (LF) in eyes for people in space has been investigated onboard Mir. Data on particles hitting the eye have been collected with the SilEye detectors, and correlated with human observations. It is found that a nucleus in the radiation environment of Mir has roughly a 1% probability to cause an LF, whereas the proton probability is almost three orders of magnitude less. As a function of LET, the LF probability increases above 10 keV/micrometer, reaching about 5% at around 50 keV/micrometer.

Aerospace Medicine↗
PubMed2001

p27-p16 fusion gene inhibits angioplasty-induced neointimal hyperplasia and coronary artery occlusion.

Inhibition of proliferative neointima formed by vascular smooth muscle cells is a potential target in preventing angioplasty-induced restenosis. We have created a potent antiproliferative by fusing the active regions of the p27 and p16 cell cycle inhibitors. Intravascular delivery of a replication-deficient adenoviral vector (AV) encoding this p27-p16 fusion protein, named W9, inhibited balloon injury-induced neointimal hyperplasia in rabbit carotid arteries. In a therapeutically more relevant model, AV-W9 was delivered to balloon-injured porcine coronary arteries in vivo using an infusion catheter. Of the three coronary arteries, two were injured with a 15-mm balloon catheter and either were left untreated or were treated with 10(12) viral particles of either AV-W9 or a control null virus. AV-W9 treatment significantly inhibited neointimal hyperplasia in this porcine arterial balloon injury model compared with untreated or control virus-treated vessels. The average intimal area of the AV-W9-treated group 10 days after balloon injury and treatment was 0.42+/-0.36 mm(2), whereas the AV-null group demonstrated an intimal area of 0.70+/-0.52 mm(2). At day 10 the average intimal thickness of the AV-W9-treated vessels was 9.1 microm (n=5, x 20 magnification) compared with 21.2 microm (n=5, x 20 magnification) in control virus-treated vessels. This trend was also observed at 28 days after balloon injury and gene transfer during which AV-W9-treated vessels demonstrated an average intimal thickness of 4.7 microm (n=8, x 20 magnification) compared with 13.3 microm (n=3, x 20 magnification) in control virus-treated vessels and 7.3 microm (n=5, x 20 magnification) in the sham-treated vessels. The AV-W9 treatment was safe and well tolerated. These data suggest that AV-W9 gene therapy may be useful in preventing angioplasty-induced intimal hyperplasia in the coronary artery.

Adenoviridae↗
PubMed2001

The community integration measure: development and preliminary validation.

OBJECTIVE: To present a new measure of community integration, the Community Integration Measure (CIM), and to offer preliminary information about its psychometric properties. DESIGN: Validation study. SETTING: Community. PARTICIPANTS: Ninety-two participants placed in 3 subgroups (brain injury survivors, n = 41; significant others, n = 36; college students, n = 15). MAIN OUTCOME MEASURES: The distributional properties, factor structure, internal consistency reliability, content validity, discriminant validity, concurrent validity, and construct validity of the CIM. RESULTS: All items correlated positively with each other and with the total score. Principal components factor analysis confirmed a 1-factor structure, which explained 44.1% of the variance. Internal consistency reliability, using Cronbach's alpha, was.87. Content validity was assured by the development procedure, correspondence with the theoretical model, and direct use of consumer language. Discriminant validity was supported by the CIM's ability to differentiate between subsamples. Criterion validity was supported by using correlations with the Community Integration Questionnaire. Construct validity was supported by correlations with the Interpersonal Support Evaluation List. CONCLUSION: The CIM offers a brief, easily administered measure of community integration that conforms to an empirically derived theoretical model and is psychometrically sound.

Activities of Daily Living↗
PubMed2001

Risk behaviours and self rated health in Russia 1998.

OBJECTIVES: As self rated health and mortality represent different dimensions of public health and as risk behaviours have been closely related to mortality, we wanted to examine whether (poor) self rated health on the one hand and risk behaviours on the other can be attributed to different causes. METHODS: The Taganrog household survey (1998) was conducted in the form of face to face interviews and included 1009 people and their families. To estimate health differences and differences in risk behaviours between groups, logistic regressions were performed. RESULTS: In Taganrog between 1993/94 and 1998, changes in self rated health seem to have been much more dramatic than changes in smoking and different in direction from changes in heavy alcohol consumption. Moreover, self rated "poor" health was especially common among those whose economic situation was worse in 1998 than 10 years before. However, having a poorer economy during the period 1988-1998, does not seem to have affected drinking or smoking habits significantly. CONCLUSIONS: Self rated health seems to be closely related to three indicators of economic circumstances. Risk behaviours are probably important for the poor state of public health in Russia, but may be less sensitive to the economic aspects of the transition than is self rated health.

Adult↗
PubMed2001

Defining community integration of persons with brain injuries as acculturation: a Canadian perspective.

In this study, the AIMS, a measure of community integration developed from acculturation theory, was used to explore the various ways that people with brain injuries, a smaller cultural or minority group, are involved with the larger cultural group and to evaluate rehabilitation outcome (i.e., reintegration into the community). Specifically, the AIMS assesses whether the needs of individuals with brain injuries in a number of areas are identified and supported in a way that supports community participation. In addition, the opinions of persons with a brain injury regarding their level of community integration were compared to the opinions of individuals who knew them well. The results of this study indicate that while a large proportion of the participants with brain injuries were integrated in traditional areas of service delivery such as medical services, housing and social activity, their disability-related needs were not being identified and supported adequately in the areas of spirituality and productive activity.

Acculturation↗
PubMed2001

The ALTEA facility on the International Space Station.

The ALTEA project studies the problems related to possible functional damage to the Central Nervous System (CNS) due to particle radiation in space environment. The project is a large international and multi-disciplinary collaboration. The ALTEA instrumentation is an helmet-shaped multi-sensor device that will measure concurrently the dynamics of the functional status of the visual system and the passage of each particle through the brain within a pre-determined energy window. ALTEA is scheduled to fly in the International Space Station in February 2003. One part of the multi-sensor device, one of the advanced silicon telescopes, will be launched in the ISS in early 2002 and serve as test for the final device and as discriminating dosimeter for the particle fluences within the ISS.

Aerospace Medicine↗
PubMed2000

First Mass-resolved Measurement of High-Energy Cosmic-Ray Antiprotons.

We report new results for the cosmic-ray antiproton-to-proton ratio from 3 to 50 GeV at the top of the atmosphere. These results represent the first measurements, on an event-by-event basis, of mass-resolved antiprotons above 18 GeV. The results were obtained with the NMSU-WIZARD/CAPRICE98 balloon-borne magnet spectrometer equipped with a gas-RICH (Ring-Imaging Cerenkov) counter and a silicon-tungsten imaging calorimeter. The RICH detector was the first ever flown that is capable of identifying charge-one particles at energies above 5 GeV. The spectrometer was flown on 1998 May 28-29 from Fort Sumner, New Mexico. The measured p&d1;/p ratio is in agreement with a pure secondary interstellar production.

Journal Article↗
PubMed2000

Study of cosmic rays and light flashes on board Space Station MIR: the SilEye experiment.

The SilEye experiment aims to study the cause and processes related to the anomalous Light Flashes (LF) perceived by astronauts in orbit and their relation with Cosmic Rays. These observations will be also useful in the study of the long duration manned space flight environment. Two PC-driven silicon detector telescopes have been built and placed aboard Space Station MIR. SilEye-1 was launched in 1995 and provided particles track and LF information; the data gathered indicate a linear dependence of FLF(Hz) ( 4 2) 10(3) 5.3 1.7 10(4) Fpart(Hz) if South Atlantic Anomaly fluxes are not included. Even though higher statistic is required, this is an indication that heavy ion interactions with the eye are the main LF cause. To improve quality and quantity of measurements, a second apparatus, SilEye-2, was placed on MIR in 1997, and started work from August 1998. This instrument provides energetic information, which allows nuclear identification in selected energy ranges; we present preliminary measurements of the radiation field inside MIR performed with SilEye-2 detector in June 1998.

Cosmic Radiation↗
PubMed2000

Educational differences in self-rated health during the Russian transition. Evidence from Taganrog 1993-1994.

In the beginning of 1992, in order to do away with the ruins of the old communist system once and for all, radical economic reforms--'shock therapy'--were introduced in Russia. However, there are winners and losers in the Russian transition from communism to market economy and democracy. The aim of the study is to investigate whether there are educational differences in self-rated health among the citizens of Taganrog in 1993-94. If there are indeed differences, the second aim is to investigate whether they can be explained by variations in specific social, economic and psychological circumstances, which are known to be affected by the present social and economic transformation in Russia. The analysed survey was carried out in a middle-sized Russian city, Taganrog, in late 1993 and early 1994. It was conducted by means of face-to-face interviews, with a sampling frame consisting of dwellings selected from an official register and stratified by type and size. The analysed sample consists of 2372 respondents, aged 25-54 years, in 1414 households. Data were analysed in logistic regressions with self-rated health as a dichotomised outcome variable. The results show that those with less than compulsory education reported poor health twice as often as the highest-educated group. Material prosperity and relations within the family were important for self-rated health and explained to a certain degree the educational health differences. Lower educational groups now live under conditions often characterised by economic hardship, family conflicts, etc., and consequently also poor health.

Adaptation, Psychological↗
PubMed2000

Melioidosis presenting as urinary tract infection in a previously healthy tourist.

Melioidosis is a tropical disease caused by Burkholderia pseudomallei, which is common in southeast Asia and Australia, but which is rarely diagnosed in Scandinavia. An increasing number of cases are being reported among tourists to infected areas. We report the first Finnish case of melioidosis, which presented as urinary tract infection in a previously healthy male tourist.

Anti-Infective Agents, Urinary↗