AIM OF THE STUDY: The extent of degenerative changes in the lumbar spine as seen on conventional radiographs is interpreted on the basis of visualized osseus structures and indirect signs such as diminution of disc height. In order to analyze the accuracy of these interpretations we compared and correlated different stages of degeneration in conventional radiographs with cuts of large-specimen cryomicrotome sections (LSCS), offering a direct macroscopic vision of the degenerative anatomic features. METHOD: A total of 50 human cadaver lumbar spines with 251 spine segments (Th 12 - S1) was investigated by plain radiograms and LSCS. The degenerative changes were differentiated into 5 stages for both diagnostic measures. Criteria for radiological degeneration were: diminution of disc space, presence of osteophytes and sclerosis of the endplates. Degenerative changes as seen by LSCS were evaluated by the following features: cracks in the endplate, bleeding into the intervertebral disc, alignment of the annulus fibrosus fibres and osseous alterations in the spine segment. RESULTS: Complete matches of the evaluated radiological and macroscopic stages of degeneration were observed in 206 cases. A difference of 1 degree on the degeneration scale was registered in 42 segments, whereas a difference of 2 degrees was seen in 3 cases. The correlation coefficient between the degeneration stages of the two diagnostic measures scored rho = 0.883. CONCLUSION: The comparison of the different degrees of degeneration in the lumbar spine as evaluated by both plain radiographs and LSCS revealed a good correlation.

Adolescent↗

PubMedDate not supplied

OPS imaging of human microcirculation: a short technical report.

Despite the pivotal role of microcirculation in numerous diseases, techniques for the direct assessment of human microcirculation are limited. A new approach based on orthogonal polarization spectral (OPS) imaging (Cytoscan microscope) allows noninvasive observation of human microcirculation in all accessible tissue surfaces. Limitations remain: application of pressure with the instrument affects blood flow, lateral movement of tissue precludes continuous investigation of a given microvascular region, and blood flow velocities above 1 mm/s cannot be measured. We addressed these problems by (a) constructing an attachment to the probe, preventing direct contact of the instrument with the observed tissue area and allowing fixation of the tissue, and (b) implementing a double-flash spatial correlation technique extending the measuring range for blood flow velocities up to approximately 40 mm/s. The modified approach was tested in vitro and in vivo. Velocity readings correlated well with velocities of an external standard (r(2) = 0.99, range 1.9-33.8 mm/s). Pulsatile flow patterns synchronous with heart rate with maximal velocities of about 10 mm/s could be detected in arterioles of the human sublingual mucosa. The modified instrument may prove useful to investigate the microcirculation in the context of research, diagnosis and therapy control.

Adult↗

PubMedDate not supplied

[An approximation method for the computation of the dependence of the conductivity index on capillary blood-flow (author's transl)].

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Body Temperature Regulation↗

PubMedDate not supplied

Use of vascular and non-vascular models for the assessment of temperature distribution during induced hyperthermia.

We developed a three-dimensional thermal model in which convective heat transfer in a human extremity is explicitly quantified by taking into account the physical details of the vascular system. The spatial pattern in the arterial, venous and tissue temperature is computed during hyperthermia treatment. As such a complex vascular model is not generally applicable, a comparative study of the results of simpler, substitutional, non-vascular concepts applied to hyperthermia was carried out. It turned out that classical bioheat approaches may lead to wrong conclusions. Satisfactory results are to be expected from an approach suggested by Wissler/Baish and Charny/Levin, and by a far simpler efficiency function (EF) concept, developed by us, that can be used as easily as the simple classical Pennes approach while avoiding its deficiencies. The EF model is used to predict whether the temperature of the entire volume of vascularized muscle tissue will be raised to a therapeutic level. With the help of the vascular model, local thermal non-uniformities near individual blood vessels are analysed. Underheating in small volumes of tissue near the vessel walls is detected. This might explain tumour regrowth following local hyperthermia treatment in the tissue adjacent to blood vessels.

Blood Vessels↗

PubMedDate not supplied

Surgical treatment of parathyroid carcinoma (Review).

Cancer of the parathyroid gland is rare and most patients suffer from hyperparathyroidism (HPT). Therefore it is often difficult to distinguish between benign HPT and malignant disorders. Prognosis as well as therapeutic approaches are still limited. Surgical treatment should be considered the therapy of choice for primary and recurrent manifestation of parathyroid carcinoma. The initial operation includes en-bloc resection of the tumor and the ipsilateral thyroid lobe. Surgery may cure some patients, but is often only palliative and aims to control hypercalcemia. In some patients hypercalcemia may be refractory to repeated surgery and medical treatment can provide short- or middle-term effects.

Humans↗

PubMedDate not supplied

Scenes from St. Francis.

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Burnout, Professional↗

PubMedDate not supplied

Post-exposure use of human diploid cell culture rabies vaccine.

880 individuals, 120 of which were exposed to rabid animals, were immunized pre- or post-exposure with 2 different BPL-inactivated and concentrated rabies vaccines prepared in HDC strains WI-38 and MRC-5. The vaccines were well tolerated and no major side effects were observed after primary immunization with 3-10 doses or 1 booster vaccination. The dynamics of neutralizing, antibody formation and persistence of antibodies in 4 different groups of vaccinees are described. The groups were vaccinated pre-exposure (I) on days 0, 28 and 56; (II) on days 0, 7 and 14; (III) on days 0, 3, 7 and 21; and (IV) post-exposure on days 0, 3, 7, 14, 30 and 90. High antibody levels--persisting for at least 30 months--were obtained in all patients. The CFT, using a concentrated and purified virion antigen, was highly specific for rabies virus antibody demonstration. Since in some 50 patients under severe risk, after having been bitten and/or scratched by proven rabid animals, not a single breakthough of immunity was observed during an observation time between 1/2 and 3 years, the protective effect of the HDCS-rabies vaccines seems to be excellent. With regard to their high immunogenicity and extremely low reactogenicity, the new HDCS-vaccines can be recommended for prophylactic and post-exposure immunization of man without any reserve. Data on simultaneous application of homologous anti-rabies gammaglobulin from man (20 I.E./kg body-weight) and HDCS-vaccines are also presented and discussed.

Adolescent↗