Biomedical subjects

L Tana

Publications and source records attributed to L Tana.

8 recordsLinked to original sources

PubMed2006

Introducing Vi polysaccharide typhoid fever vaccine to primary school children in North Jakarta, Indonesia, via an existent school-based vaccination platform.

OBJECTIVES: To report results on coverage, safety and logistics of a large-scale, school-based Vi polysaccharide immunization campaign in North Jakarta. METHODS: Of 443 primary schools in North Jakarta, Indonesia, 18 public schools were randomly selected for this study. Exclusion criteria were fever 37.5 degrees C or higher at the time of vaccination or a known history of hypersensitivity to any vaccine. Adverse events were monitored and recorded for 1 month after immunization. Because this was a pilot programme, resource use was tracked in detail. RESULTS: During the February 2004 vaccination campaign, 4828 students were immunized (91% of the target population); another 394 students (7%) were vaccinated during mop-up programmes. Informed consent was obtained for 98% of the target population. In all, 34 adverse events were reported, corresponding to seven events per 1000 doses injected; none was serious. The manufacturer recommended cold chain was maintained throughout the programme. CONCLUSIONS: This demonstration project in two sub-districts of North Jakarta shows that a large-scale, school-based typhoid fever Vi polysaccharide vaccination campaign is logistically feasible, safe and minimally disruptive to regular school activities, when used in the context of an existing successful immunization platform. The project had high parental acceptance. Nonetheless, policy-relevant questions still need to be answered before implementing a widespread Vi polysaccharide vaccine programme in Indonesia.

Antigens, Bacterial↗

PubMed1998

In vivo neutron dosimetry during high-energy Bremsstrahlung radiotherapy.

PURPOSE: A new technique is presented for in vivo measurements of the dose equivalent from photoneutrons produced by high-energy radiotherapy accelerators. METHODS AND MATERIALS: The dosimeters used for this purpose are vials of superheated halocarbon droplets suspended in a tissue-equivalent gel. Neutron interactions nucleate the formation of bubbles, which can be recorded through the volume of gel they displace from the detector vials into graduated pipettes. These detectors offer inherent photon discrimination, dose-equivalent response to neutrons, passive operation, and small sensitive size. An in vivo vaginal probe was fabricated containing one of these neutron detector vials and a photon-sensitive diode. Measurements were carried out in patients undergoing high-energy x-ray radiotherapy and were also repeated in-phantom, under similar irradiation geometries. RESULTS AND CONCLUSION: Neutron doses of 0.02 Sv were measured in correspondence to the cervix, 50 cm from the photon beam axis, following a complete treatment course of 46.5 Gy with an upper mantle field of 18-MV x-rays. This fraction of dose from neutrons is measured reliably within an intense photon background, making the technique a valid solution to challenging dosimetry problems such as the determination of fetal exposure in radiotherapy. These measurements can be easily carried out with tissue-equivalent phantoms, as our results indicate an excellent correlation between in vivo and in-phantom dosimetry.

Aged↗

PubMed1998

In-phantom dosimetry and spectrometry of photoneutrons from an 18 MV linear accelerator.

A combination of three superheated drop detectors with different neutron energy responses was developed to evaluate dose-equivalent and energy distributions of photoneutrons in a phantom irradiated by radiotherapy high-energy x-ray beams. One of the three detectors measures the total neutron dose equivalent and the other two measure the contributions from fast neutrons above 1 and 5.5 MeV, respectively. In order to test the new method, the neutron field produced by the 10 cm X 10 cm x-ray beam of an 18 MV radiotherapy accelerator was studied. Measurements were performed inside a tissue-equivalent liquid phantom, at depths of 1, 5, 10 and 15 cm and at lateral distances of 0, 10, and 20 cm from the central axis. These data were used to calculate the average integral dose to the radiotherapy patient from direct neutrons as well as from neutrons transmitted through the accelerator head. The characteristics of the dosimeters were confirmed by results in excellent agreement with those of prior studies. Track etch detectors were also used and provided an independent verification of the validity of this new technique. Within the primary beam, we measured a neutron entrance dose equivalent of 4.5 mSv per Gy of photons. It was observed that fast neutrons above 1 MeV deliver most of the total neutron dose along the beam axis. Their relative contribution increases with depth, from about 60% at the entrance to over 90% at a depth of 10 cm. Thus, the average energy increases with depth in the phantom as neutron spectra harden.

Biophysical Phenomena↗

PubMed1995

Risk of thyroid nodules in subjects occupationally exposed to radiation: a cross sectional study.

OBJECTIVES: To examine, by ultrasonography the prevalence of thyroid nodules in a cross sectional study of male medical workers occupationally exposed to chi radiation at the Pisa hospital, in comparison with controls matched for age and sex. METHODS: 50 male medical workers exposed to radiation were randomly matched for age (+/- 2 years) with 100 male workers not occupationally exposed to ionising radiation who lived in a slightly iodine deficient area of Tuscany (Lunigiana) (control group 1), and with 100 male workers not exposed to radiation who lived in the same area (Pisa) (control group 2). RESULTS: Of the occupationally exposed subjects, thyroid nodules were detected in 19/50 (38.0%). Among controls, thyroid nodules were detected in 19/100 subjects of control group 1 and in 13/100 of control group 2. Comparison of exposed and control groups, stratified into 30-39, 40-49, and 50-59 year old age subgroups, showed a higher significant relative risk for thyroid nodules in the exposed subjects. CONCLUSION: The results suggest that occupational exposure to radiation may be a risk factor for thyroid nodules.

Adult↗

PubMed1995

[Lithium therapy and drinking water].

ain causes of failure and giving up in psychotropic lithiotherapics because of instable lithiemy to the same patient or functional acute renal insufficiency, are principaly mistaken diets, those mistaken concerning the amount, the quality and the way of taking drinking water and other beverages. Lithium salt, taken either in two times, morning and evening, or in one, must be absorbed at the end of a solid meal with at least 25 cl. of water. The patient must absorb at least 1.5 l. of water per day, and up to 3 l. in case of physical efforts or heat. The pH of this water and it ionic compound should be stable, as close as possible to the plasma's, without additives that could change its taste. This includes cooking water and infusions. Physicopharmacological explanations.

Drinking Behavior↗

PubMed1994

[Computer-assisted combined management of physical radiation protection and quality control of X-ray diagnostic equipment].

A software for the computer-assisted management of radiation protection and quality control of radiodiagnostic equipment is described. The code was written in DB3-plus language. In addition to some independent archives on X-ray diagnostic systems identification, it includes technical and radiation protection checks, environmental dosimetry in the controlled areas and on workers. The data can be searched through a key field and periodical radiation protection reports and action reports can be printed. The software programs can also perform some "intelligent" operations such as the calculation of controlled areas range and the classification of X-ray diagnostic systems and workers. This is done by retrieving the information from the archives. The software can be updated, revised and modified very easily, due to the non-connection of the archives. It is also very simple to connect DB3-plus archives with many other software packages to process and elaborate data. This software is the core of an integrated system we are developing to store and process data from diagnostic X-ray systems control meters and from our TLD personal dosimetry equipment.

Computer Systems↗

PubMed1990

[A decade's experience with electron radiotherapy].

The experience related to 1170 patients treated with electron beam between 1979-1988 at Radiation Therapy Department in Pisa is reported. Beam dosimetry and dose distribution in tissue, patients contour and other parameters have been analysed as main important factors to optimise this technique. Electron beam therapy offers important contributions to the management of peculiar types of cancer because of the radiotherapy treatments optimisation and the reduced normal tissue reactions.

Breast Neoplasms↗

PubMedDate not supplied

Is occupationally induced exposure to radiation a risk factor of thyroid nodule formation?

The prevalence of thyroid nodules was studied with ultrasonography in a group of male hospital workers (n = 44) who had been exposed occupationally to x-rays. This group was compared with a group of nonexposed workers (n = 88) who were age- and sex-matched with the exposed workers. Thyroid nodules were detected in 18 (41%) of the exposed workers, compared with 11 (13%) of the nonexposed controls. Both groups were subdivided with respect to age (i.e., 30-39 y, 40-49 y, 50-59 y), and there was a higher and significant relative risk for thyroid nodule formation in the exposed group. We also divided the groups into subgroups according to levels of exposure (i.e., nonexposed, exposed for < 20 y, and exposed for > 20 y), and a significant result was obtained with the linear-trend chi-square test. The preliminary results of our study suggest that occupationally induced exposure to radiation may be a risk factor for thyroid nodule formation.

Adult↗