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Biomedical subjects

J M Jensen

Publications and source records attributed to J M Jensen.

72 records · Page 4Linked to original sources
PubMed1983

Increase of MLC sensitivity by elimination of a non-adherent responder cell subpopulation with anti-macrophage serum.

A specific rabbit anti-rat macrophage antiserum (SAM) was prepared with a cytotoxic reactivity pattern complementary to that of a specific anti-lymphocyte serum. This was used to characterise adherent and non-adherent spleen cell subpopulations in mixed lymphocyte cultures. Adherent SAM+ cells reacted as accessory cells whereas non-adherent SAM+ cells were suppressors. Selective elimination thus achieved resulted in a highly significant increase of MLC reactivity in certain strain combinations and in conversion from non-reactivity to reactivity in others.

Animals↗
PubMed1983

[Tissue activation by bremsstrahlung from medical accelerators].

If a continuous radiation with a maximum energy of more than 10.55 MeV is used in radiotherapy, there is an activation of tissue. A radiation exposure of the staff may be connected with this activity induced by the nuclear photon effect. The consequences for routine radiotherapy are demonstrated by the examples of a betatron 42 MeV and a linear accelerator Clinac 20.

Humans↗
PubMed1982

[New investigations about the activation of air by the 42-Mev continuous radiation of a betatron (author's transl)].

Measurements of the activity of urea are a simple and reproducible method to determine the activation of air produced by the continuous radiation of a medically used accelerator [3,4]. The authors studied the activity produced by photonuclear induction using a 42 MeV betatron under unfavorable irradiation conditions. The activity measured per individual irradiation is 1.56 x 10(5) Bq 13N and 4.93 x 10(5) Bq 15O. The limit values indicated in the Radioprotection Regulation are not reached if an intensive air exchange and a waiting-time between the end of the irradiation and the entering of the irradiation room is guaranteed.

Air↗
PubMed1982

[Measurement of the air activation caused by the use of medical accelerators].

The air is activated when a medical accelerator is operated in order to produce a continuous radiation the maximum energy of which is higher than 10.55 MeV. The induced activity can be measured by a simple method. The consequences regarding radiological protection and the organization of continuous radiation therapy with the examined accelerators (Clinac 20, Betatron 42 MeV) are discussed.

Activation Analysis↗
PubMed1981

Comparative pathology of the African form of malignant catarrhal fever in captive Indian gaur and domestic cattle.

The African strain of malignant catarrhal fever virus was isolated and identified in a herd of captive Indian gaur (Bos gaurus). Gross lesions included oral ulcerations, corneal opacity, and multifocal myocarditis. Microscopic lesions were characterized by lymphocytic vasculitis/perivasculitis in all tissues examined. Blood was serially passed from a gaur to a domestic heifer (Bos taurus), and then to a domestic calf. Clinical signs and gross and microscopic lesions similar to those of the gaur were seen in both inoculated animals.

Animals↗
PubMed1981

[Measurement and calculation of the air activation caused by 15 MeV continuous radiation emitted by a linear accelerator (author's transl)].

The rate of air activation caused by the 15 MeV continuous radiation of a "Clinac 20" can be concluded from activation measurements in urea tablets. In case of the most unfavourable irradiation conditions, a maximum field size of 35 X 35 cm2, and a distance focus-wall of 450 cm, an air activation of 6, 18 X 10(4) Bq per individual irradiation is calculated. The limit of activity concentration prescribed by the Strahlenschutzverordnung (radioprotection directive) is not reached if a sufficient change of air is guaranteed. This method of measuring the air activation is simple, not time-consuming and can be effected with a high degree of accuracy. Measurements and calculations are compared.

Air↗
PubMed1981

[Measurements of the surface dose for the irradiation of cultured cells with a Co-60 source (author's transl)].

In order to exactly determine the irradiation dose for cultured cells in culture containers (Petri dishes and others), it is necessary to have a detailed knowledge of the depth dose curve in water-equivalent layers near the surface. This curve was determined for Co-60 radiation by means of a window-less liquidity dosemeter. The dosemeter liquid was a solution of ammonium-iron (II) sulfate (solution of Fricke), the extinction of which was measured at 304 nm. Petri dishes were used instead of closed irradiation flasks. The distance QOA was 50 cm for all experiments, the field size was 10 X 10 cm. The depth dose maximum was found in a depth of 5,0 mm which corresponds to a mass of 0,50 g cm-2 relating to the surface. The surface dose was determined to be 39,2% and 106,6% of the maximum dose, respectively. This method can also be applied for closed culture containers (flasks).

Cells, Cultured↗
PubMed1979

Fatal Beauveria bassiana infection in a captive American alligator.

The entomopathogenic fungus, Beauveria bassiana, was isolated from pulmonary lesions of a dead American alligator (Alligator mississipiensis) at the Oklahoma City Zoo. Colonies of the fungus, which had sporulated in vivo, were found in the thoracic air spaces. Septate, branching hyphae and fungal spores were seen in stained histologic sections of pleura and lung. Dissemination to other viscera had not occurred. This case indicated that B bassiana, a rare vertebrate pathogen, may be a fatal mycotic agent in captive reptiles.

Alligators and Crocodiles↗
PubMed1979

Fatal mycotic pulmonary disease of captive American alligators.

Fatal pulmonary disease occurred in two captive American alligators. The entomopathogenic fungus, Beauveria bassiana, was isolated from pulmonary lesions in both alligators. An extended hibernation period because of a severe winter and a failure of the zoo heating system may have predisposed the alligators to infection.

Alligators and Crocodiles↗
PubMedDate not supplied

Assisting older adults with severe disabilities in expressing leisure preferences: a protocol for determining choice-making skills.

We evaluated a protocol involving two types of choice presentations for assessing leisure choice-making skills of seven older adults with severe disabilities. Initially when presented with pairs of objects representing choices, choice making was validated through demonstration of an object preference. A more complex choice-presentation format was then employed, involving pictures to represent choices. If the preference identified with objects was not demonstrated using pictures, a replication of the object format occurred to ensure changes in choice making using pictures was not due to a preference change. Five participants demonstrated choice-making skills using objects and two demonstrated choices using pictures. These results reflect the importance of assessing choice-making skills prior to presenting choice opportunities. Suggestions for future research focus on expanding the assessment protocol to include a wider array of choice-making skills and training staff to provide choices in a format commensurate with an individual's skill level.

Activities of Daily Living↗
PubMedDate not supplied

Supervisory training for teachers: multiple, long-term effects in an education program for adults with severe disabilities.

We evaluated a means of training special education teachers in supervisory strategies for improving specific teaching-related performances of their paraprofessional, teacher assistants. Using classroom-based instruction and on-the-job monitoring and feedback, seven teachers were trained to systematically observe the data collection and teaching performances of their assistants as well as to provide contingent feedback. The supervisory training for teachers, evaluated using a multiple-probe design across groups of assistants, was accompanied by improvements in data collection performances among seven of eight assistants. Improvement in other teaching skill applications also occurred. The improved performance among the assistants was maintained across a 17-month follow-up period. The supervisory training seemed to have multiple benefits in that the teachers' own teaching-related performances improved once teachers were trained to systematically observe and provide feedback to their assistants. The need for continued research is discussed to evaluate the benefits of supervisory training to improve and maintain other important areas of staff performance.

Adult↗
PubMedDate not supplied

The systolic hypertension in the elderly program. Implications for nursing practice and research.

The Systolic Hypertension in the Elderly Program (SHEP) encompasses two clinical trials--a pilot study and a full-scale trial--investigating the safety and efficacy of antihypertensive therapy for patients aged 60 years and over with isolated systolic hypertension (ISH), that is, systolic blood pressure (SBP) greater than or equal to 160 mmHg and diastolic blood pressure (DBP) less than 90 mmHg. An optimal result of the full-scale trial should lead to recommendations for prescription of effective therapy that preserves the quality of life while reducing the long-term risks of stroke, other cardiovascular disease, and death. This article briefly describes the design, protocol, and organization for the pilot and fullscale SHEP studies. In these trials the nurses help plan study protocol, coordinate patient recruitment, provide patient care, and maintain protocol compliance. In order to accomplish their role in data collection and reporting, they undergo comprehensive training and certification. Nurses utilize the multicenter clinical trial as an opportunity to participate in research, both independently and collaboratively. The specific roles of nurses within these trials, as well as features of these trials that relate to nursing practice and research, are discussed.

Aged↗