PubMed Health⌕ Search

Biomedical subjects

G Németh

Publications and source records attributed to G Németh.

At least 109 records · Page 6Linked to original sources
PubMed1989

The axis of rotation of the ankle joint.

The axis of the talo-crural joint was analysed by roentgen stereophotogrammetry in eight healthy volunteers. Examinations were performed at 10 degrees increments of flexion and pronation/supination of the foot as well as medial and lateral rotation of the leg. Results indicate that the talo-crural joint axis changes continuously throughout the range of movement. In dorsiflexion it tended to be oblique downward and laterally. In rotation of the leg, the axis took varying inclinations between horizontal and vertical. All axes in each subject lay close to the midpoint of a line between the tips of the malleoli. Our study indicates that the talo-crural joint axis may alter considerably during the arc of motion and differ significantly between individuals. This prompts caution in the use of hinge axes in orthoses and prostheses for the ankle.

Adult↗
PubMed1989

[A new irradiation method for the protection of intact tissues of the oral cavity during radiotherapy of tumors in the mandibular region].

A new collimator system employable at ray treatment of mouth cavity tumors is reported on. A Multi- Collimator-Ring (MCR) ensures, in addition to a homogenius irradiation of the target volume, also the low ray load of the normal tissues around the tumor. At the ray treatment of tumors in the area of the low jaw bone the employment of the MCR....

Dose-Response Relationship, Radiation↗
PubMed1988

The vulnerability of gerbils to focal cerebral ischemia. Neurological signs and regional biochemical changes after ischemia and recirculation.

Gerbils of both sexes were used to study the effects of 30-min ischemia and subsequent recirculation for 4 and 8 days. The mortality rate was 9% during ischemia and 34% in the recirculation period. No close correlation was found between the extent of metabolic changes and the severity of clinical signs after ischemia. Gerbils exhibited severe clinical signs with metabolic patterns of severe hypoxic damage, but with only slight biochemical changes as well, stressing the necessity of detailed examination in regional metabolic studies. According to planimetrical evaluation the most sensitive indicator of ischemic damage was alteration in pH. Decrease in pH without changes in ATP and NADH was associated with severe clinical signs. Biochemical changes were demonstrated after recirculation in some gerbils having severe clinical signs at the end of the ischemic period. The changes in pH and potassium found 8 days after the ischemic insult stress that a 30-min focal ischemia might have long lasting, perhaps irreversible consequences.

Adenosine Triphosphate↗
PubMed1988

Akinetic mutism associated with bicingular lesions: clinicopathological and functional anatomical correlates.

The clinical symptoms and neuropathological findings of three patients suffering from akinetic mutism were summarized. The patients showed almost absolute mutism and immobility and were unable to communicate in any way. The neurological signs varied from case to case. The pathological features common to all of the cases were bilateral lesions of the rostral part of the anterior cingulate gyri which overlapped onto the neighboring supplementary motor area, while differing as regards other damage. With the help of more recent neurobiochemical findings we tried to analyze the pathomechanism of akinetic mutism on the basis of the structures damaged. There seems to be an anatomic correspondence between the mesolimbocortical dopaminergic system and the circumscribed bilateral lesions of the medial prefrontal cortex. The study suggests that damage of the mesolimbocortical dopaminergic terminal fields in the anteromedial frontal cortex is essential for this specific type of akinetic mutism.

Aged↗
PubMed1988

[Dermatofibrosarcoma protuberans. Results of radiosurgical therapy by photon and electron rays or fast neutrons].

The dermatofibrosarcoma protuberans, a rare entity of soft tissue sarcomas, is specified as a tumor of intermediate malignancy because of its marked tendency to form local recurrences. Regarding the prevention of local recurrences, the results of combined radiosurgical therapy (n = 13) could be improved in our patients by the application of fast neutrons (n = 6). Despite multiple previous operations for recurrences, a reliable prevention of local recurrences (average follow-up period 5.5 years) was achieved in all patients by neutron irradiation with focal doses of approximately 9 Gy. One patient with multiple macroscopic recurrences received two neutron series with 17 Gy. At seven years, she is still recurrence-free. We consider the postoperative irradiation of the dermatofibrosarcoma protuberans with fast neutrons following to primary tumor excision as method of choice for a reliable prophylaxis of local recurrences, because this method allows to dispense with major radical surgery.

Adult↗
PubMed1988

Thymocytotoxic antibodies in synovial fluid.

Synovial fluid (SF), obtained from patients with juvenile rheumatoid arthritis (JRA), osteochondritis, traumatic synovitis and septic arthritis were tested for the presence of thymocytotoxic activity. Such activity, directed against guinea pig thymocytes, was earlier demonstrated in human serum and shown to be mediated by IgM antibodies and a heat labile factor, most likely complement. The cytotoxic activity was demonstrated in all SFs tested, and was abolished by either one of the following procedures: depletion of IgM by use of anti-IgM-antibody coated protein A-Sepharose, or heating to 56 degrees C for 30 min. Activity was regained when samples inactivated by these two procedures were recombined. The cytotoxic SFs produced similar distortion of cell volume distribution of the target thymocytes as previously has been shown with human serum. The findings indicate that the two cytotoxic activities are identical. In most cases the IgM levels and the cytotoxic activity were lower in SF than in normal serum. Although the material does not permit correlation of cytotoxic activity with specific joint conditions, a high SF cytotoxicity was noted in two out of four patients with JRA. The demonstration of IgM-associated thymocytotoxic activity is of interest both in connection with earlier observations of various specific antibodies in SF and in connection with speculations regarding local immune regulatory activity in the joint.

Arthritis, Rheumatoid↗
PubMed1987

Three-dimensional dose distributions for radiotherapy of sinus maxillary tumours.

Three-dimensional dose distributions for the radiation therapy of sinus maxillary tumours have been calculated. Irradiation techniques with 8 MV X-rays and 15 MV X-rays from a linear accelerator (Siemens Mevatron 74 and Siemens Mevatron 77) and 60Co gamma-irradiation (Siemens Gammatron S80) are compared to each other. Using an anterior and a lateral field, the three-dimensional dose distribution of high energy photons shows that the radiation burden of the lens and the skin is significantly lower than with the use of 60Co irradiation. Sufficient dose coverage and sparing of the lens and the skin can be reached using the irradiation technique with 8 MV X-rays.

Cobalt Radioisotopes↗
PubMed1987

Radiation therapy of intrathoracic paraaortic lymph node metastases. Three-dimensional treatment planning.

The elaboration of a CT-based three-dimensional radiation therapy plan is described, which is applicable for any location and extension of intrathoracic paraaortic lymph node metastases. Calculations for high energy photon beams from a 15 MeV linear accelerator have been performed. The treatment plan enables a high radiation dose in the target volume and adequate sparing of the spinal cord.

Aorta↗
PubMed1987

Dose reconstruction of x-ray irradiation of the larynx.

The authors have determined the dose distribution in the neck for parallel opposed and three field orthovoltage X-ray irradiation techniques of the larynx. LiF:Mg, Ti rods and pellets combined with film densitometry were used. Absorbed dose measured in the region of vocal chords is about 20% lower than that assessed by assuming full backscatter (perpendicular incidence) and by using standard isodose tables.

Film Dosimetry↗
PubMed1987

Relative mechanical load on back and hip muscles in standing position when handling materials manually. A study of packing work.

Muscular load on the back and hip muscles was quantified and compared using a muscular strength utilization ratio (MUR). The MUR was obtained by dividing the total moment about the bilateral joint axis by the counteracting maximum muscular strength at the same joint angle. 72 different postures during simulated packing work were studied, with different combinations of box size, angle, edge height and weight. The MUR was calculated for a large, an average sized and a small man depending on whether they were all either strong, of average strength, or weak, thus giving nine MUR values for each posture. For a weak man, the MUR exceeded 100% in many postures. The largest box at a zero- or 30-degree angle to the horizontal with its upper edge 20 cm below elbow height gave the highest MUR, while the smallest box angled at 90 degrees with the upper edge 10 cm above elbow height gave the lowest. The presented concept of relating joint load to strength is proposed for use in preventive ergonomic counselling and in vocational rehabilitation.

Adult↗
PubMed1987

Effects of arm support or suspension on neck and shoulder muscle activity during sedentary work.

The aim of this study was to evaluate the effects on the levels on neck and shoulder muscular activity of ergonomic aids used to support or suspend the arm in different sitting postures, both with and without movement of the arm-hand. Ten skilled women workers performed a standardized simulated work cycle similar to assembling printed circuit boards, in different sitting postures with and without ergonomic aids. The elbow was supported by a loosely-mounted, padded plate. For suspension, a new device, the K-block, was used giving an adjustable, constant suspending force. Full-wave rectified, low-pass filtered, time-averaged and normalized EMG was used. Surface electrodes were applied over six neck and shoulder muscles. The results show that a reduction in the level of activity in neck and shoulder muscles can be obtained with either aid. The reduction, whether caused by suspension or support of the arm, was related to the sitting posture. Elbow support might be more efficient than arm suspension in a sitting posture with the whole spine flexed, while arm suspension might be more efficient when the trunk is inclined slightly backward. Elbow support and, particularly, arm suspension may thus be recommended as technical aids in sedentary assembly work for patients with easily elicited cervical spine and/or shoulder pain. It is also suggested that arm suspension may be used to improve ergonomic conditions at workplaces.

Adult↗
PubMed1986

Binding properties of beta-adrenergic receptors in early human fetal lung.

The characteristics of beta-adrenergic receptors in human fetal lung were examined using the beta-adrenoceptor antagonist 3H-dihydroalprenolol /DHA/. Steady-state binding was reached by 15 min at 25 degrees C, and the association and dissociation rate constants were 0.0422 nM-1 min-1 and 0.0874 min-1, respectively. From saturation experiments, Bmax of 82.0 +/- 38 fmol/mg protein and KD = 1.85 +/- 0.92 nM were calculated. Inhibition of 3H-DHA binding by beta-1 /metoprolol/ and beta-2 /zinterol, IPS-339, fenoterol/ selective drugs resulted in biphasic displacement curves with slope factors less than 1.0. Analysis of these curves revealed a beta-1: beta-2 ratio of 40:60 in human fetal lung. The presence of 3H-DHA binding sites in early human lung may have a developmental importance which is not yet understood.

Adrenergic beta-Agonists↗