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Biomedical subjects

G Németh

Publications and source records attributed to G Németh.

At least 91 records · Page 5Linked to original sources
PubMed1992

[External irradiation of differentiated thyroid cancer: 30 follow up].

UNLABELLED: Following surgery which left no macroscopic residue 114 patients with differentiated thyroid cancer (58 papillary, 56 follicular) were subgrouped on the basis of the dose of prophylactic postoperative external radiation applied: group I--an adequate dose of radiation (greater than or equal to 4500 cGy of telecobalt, greater than or equal to 4000 R of orthovolt therapy); group II--an inadequate dose of radiation (including non-irradiated patients). Local/regional relapse-free survival (LRRFS), distant metastatic relapse-free survival (DMRFS) and total cause-specific survival (TCSS) were calculated by means of life-table analysis for both histologic types separately. Results. 1. TCSS and LRRFS were significantly (p less than 0.001) better for group I in papillary cancer. No difference was found in DMRFS. 2. LRRFS was significantly (p less than 0.001) better for group I in follicular cancer. No differences were found in TCSS and DMRFS. CONCLUSIONS: 1. The prophylactic postoperative external irradiation is an effective method for survival prolongation in papillary cancer, the local/regional recurrences thereby being reduced. 2. External irradiation, in conjunction with radioiodine treatment, should be considered in the postoperative management of follicular cancer to diminish local/regional relapse.

Adenocarcinoma↗
PubMed1992

Age influences abnormalities in striatal dopamine metabolism during and after transient forebrain ischemia.

Age has been found to be a significant risk factor for brain ischemia and its mortality. After cerebral ischemia, the nigrostriatal dopaminergic system undergoes selective vulnerability with necrosis of striatal neurons. To study the effect of age and transient forebrain ischemia on striatal dopamine metabolism, investigations were performed in 1-year-old (adult) and 2-year-old (aged) male Wistar rats. A 15 min period of bilateral transient incomplete ischemia (ICI) was induced, and the concentrations of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), 3-methoxytyramine (3-MT), and homovanillic acid (HVA) were measured in the striatum by means of HPLC and electrochemical detection at the end of ischemia without reperfusion, and after 1 h, 24 h, 72 h, 144 h, and 288 h of postischemic cerebral reperfusion. In normal conditions, no 3-MT was detectable in either age group studied, and no other age-related changes could be found in DA or its metabolites. During ICI, an age-related difference became obvious in the 3-MT concentration, which was higher in aged animals. In this group, DOPAC dropped and DA turnover increased. After 1 h of postischemic reperfusion, the concentrations of DOPAC and HVA, as well as the turnover rate, had increased in both age groups, whereas an increase in the DA concentration became apparent in the adult animals only. The enhancement of the concentration of both DOPAC and HVA was more marked in adult animals than in aged ones. At 24 h of postischemic cerebral reperfusion, DA concentration was still elevated in both age groups, and HVA in the 1-year-old animals only. At 72 h of postischemic cerebral reperfusion, no differences were obvious between adult experimental animals and controls, whereas the elevated DA concentration persisted in aged animals, being higher than in the control group and in the 1-year-old rats. DA turnover was reduced. Longer periods of postischemic cerebral reperfusion were not found to be followed by any abnormalities compared with controls except for the DA concentration at 288 h (1-year-old group); nor were there any differences between the two age groups studied. The data obtained in this investigation clearly indicate age-related differences in the striatal dopaminergic neurotransmission after transient cerebral ischemia, in that in the aged brain reactions are markedly delayed after an injurious event such as ischemia.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1992

The effect of shoulder muscle training in patients with recurrent shoulder dislocations.

Thirty-three shoulders in 29 patients with recurrent shoulder dislocations, of both traumatic and nontraumatic type, have been studied. The patients suffered from muscle weakness, and had also a hypotrophy of the supra- and infraspinatus muscles. A special training program using an isokinetic pulley-weight apparatus, for muscle strength, coordination and endurance training of the rotator-cuff muscles and the deltoid were given all patients. Shoulder flexors, internal and external rotator muscles were trained three times a week, during a period of 8 weeks. At follow-up one year after completion of the specific training program all shoulders except five were improved. Five shoulders had remaining instability. Four of these patients had generalized joint laxity and a much decreased humeral head retroversion, and were later on stabilized with a rotational osteotomy of the proximal humerus. One of the shoulders with remaining instability was of traumatic type with normal skeletal anatomy. This patient was later on stabilized with a Putti-Platt procedure. We conclude that most of the patients were relieved from pain, and had decrease or cessation of their dislocations. Factors indicating a less good result of training were an abnormal skeletal anatomy, and/or a multidirectional type of instability.

Adult↗
PubMed1991

[Ovulation inhibition with RU 486].

Starting from the theory, that progesterone (P) may be one of the triggers of physiologic ovulation, P receptor blocking agent Mifepristone was administered to 7 regularly menstruating women, 2 days before the expected time of ovulation. Ovulation was monitored by ultrasound folliculometry and determination of serum estradiol (E2), P and luteinizing hormone (LH) levels. The luteal phase was checked by measuring urinary pregnandiol glucuronide excretion. Administration of the drug was properly timed in 5 cases, none of the existing follicles ruptured, one got luteinized and 4 had undergone atresia. According to these findings P seems to be a trigger of ovulatory events.

Contraceptives, Oral↗
PubMed1991

Changes in striatal dopamine neurohistochemistry and biochemistry after incomplete transient cerebral ischemia in the rat.

To evaluate the development of striatal ischemic cell damage in relation to alterations in dopamine (DA) transmission, one year old male Wistar rats underwent a 15 min incomplete cerebral ischemia (ICI) induced by occlusion of the common carotid arteries and by hypovolemic hypotension. The animals were divided into the following experimental groups: sham operated rats, rats with ICI without reperfusion, and rats with ICI followed by 60 min, 24 h, 72 h and 144 h of recirculation. The ischemia induced striatal lesions were investigated in serial coronal brain sections, stained with cresylviolet or immunostained for dopamine and cAMP regulated phosphoprotein (DARPP-32), for tyrosine hydroxylase (TH) and for glial fibrillary acidic protein (GFAP) immunoreactivities (IR). Measurements of striatal dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) levels were made on analogous experimental groups using HPLC methods. Signs of degeneration in small to medium sized neurons were already seen after 60 min of postischemic reperfusion together with slight decreases of DARPP-32 IR and increases of GFAP IR. The damage continued to increase up to 144 h, and after 24 h of recirculation there were clearly defined areas of reduced DARPP-32 IR, overlapping with increased TH IR and increased GFAP IR. The levels of DA, DOPAC and HVA increased sharply after 60 min (151%, 462% and 201%, respectively) remained high after 24 h and normalized after 72 h of recirculation. The DA metabolism was high after 60 min and had already normalized after 24 h of recirculation. The increased DA metabolism in striatal nerve terminals in response to ischemic injury may reflect an early degenerative change in the DA terminals. The long-lasting increase in TH IR may to some extent represent an adaptive change in response to the disappearance of DA receptor-containing nerve cells. Based on the present findings it is possible that an increased D1 transmission in neostriatum immediately following the ischemic injury may contribute to striatal nerve cell degeneration in which an enhancement of NMDA receptor transduction may be implicated.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1991

Three-dimensional photon radiotherapy planning for laryngeal and hypopharyngeal cancers. 1. Conventional rotational technique.

Three-dimensional dose distributions have been computed for the photon radiation therapy of laryngeal and hypopharyngeal cancers, using biaxial and eccentric rotatory techniques. Treatment plans obtained under various conditions of irradiation with a 15 MV linear accelarator (MEVATRON 77, Siemens) are analysed and compared. Dose delivery to the tumour and the degree of spinal cord protection are evaluated for both treatment techniques. The eccentric plan is somewhat superior to the biaxial one, suggesting a justifiable preference to use this method in the radiation treatment of these tumours. Simulations show that extreme care is needed in positioning the axis: an accuracy of +/- 3 mm is required in the sagittal plane.

Humans↗
PubMed1991

Three-dimensional photon radiotherapy planning for laryngeal and hypopharyngeal cancers. 2. Conformation treatment planning using a multileaf collimator.

Three-dimension dose distributions have been computed for 15 MV X-ray radiation therapy (MEVATRON 77, Siemens) of laryngeal and hypopharyngeal cancers using isocentric rotational technique with multileaf collimator. Using a new concave contour tracing algorithm, satisfactory dose delivery to the target volume and efficient protection of the normal tissues can be achieved.

Humans↗
PubMed1991

[Radiation moulage therapy of gingival tumors].

An irradiation treatment technique, long ago known yet seldom employed, is reported on. With a patient, because of an inoperable gingiva-tumor, after percutan irradiation for complementary purpose radium-moulage treatment was employed. Due to the irradiation treatment the patient became symptomless.

Aged↗
PubMed1991

Differences in shoulder muscle activity between patients with generalized joint laxity and normal controls.

The aim of the present study was to analyze shoulder muscle activity in patients with generalized joint laxity and shoulder instability and to compare it with muscle activity recorded in healthy subjects from an earlier study. Electromyographic (EMG) activity was recorded from eight shoulder muscles in six patients using surface and intramuscular fine-wire electrodes. Recordings were made from the subscapularis, supraspinatus, infraspinatus, pectoralis major (sternoclavicular part), the anterior, middle, and posterior parts of the deltoid, and the latissimus dorsi. The EMG signal was low-pass filtered, full-wave rectified, and time-average. Normalization of the EMG allowed interindividual and intraindividual comparisons. During abduction and flexion, muscle activity in the anterior and middle parts of the deltoid was significantly decreased in the patients, and during internal rotation activity in the subscapularis was increased. As in healthy subjects, patients showed simultaneous activity in both those muscles producing the movement and in the antagonistic muscles. The altered muscle activity observed in patients with generalized joint laxity provides (1) a basis for understanding the mechanism of their shoulder instability and (2) the rationale for a physical training program for these patients.

Adult↗
PubMed1990

[Subscapular liver hematoma and liver hemorrhage in neonatal age].

By analysing their newborn patients of 15 years the authors confirm the earlier observation, that the subcapsular haematoma is a common finding at postmortem examination of the newborns dying during neonatal period. The association of the pathological symptoms of hypoxic origin of the other organs observed at autopsy and the decreasing incidence of subcapsular haematoma as a results of obstetrical and neonatal intensive care make this disease of hypoxic origin probable. In spite of common subcapsular haematoma the haemorrhage of liver causing haemascos is relatively uncommon. In their five patients suffering from liver rupture they observed two types of this (immediate and delayed rupture of liver's capsule), which also differed from one another in their clinical picture. They are drawing attention to general use of ultrasound in diagnostics which means a new chance to diagnosis in alive of both types.

Hematoma↗
PubMed1990

Electromyogram (EMG) recordings from the subscapularis muscle: description of a technique.

Operative treatments for recurrent dislocation of the shoulder usually focus on the subscapularis muscle because it is supposed to contribute to the joint stability. It is of clinical interest to record the EMG from the subscapularis muscle in order to interpret its function. The purpose of the present study was to describe a safe and reliable route to reach the muscle, deeply located between the scapula and the thoracic cage, with fine-wire EMG electrodes. Twenty-four shoulders were investigated in 12 volunteers. A hypodermic needle containing bipolar fine-wire electrodes was inserted in the posterior axillary line with the subjects in the supine position, and the arm held in an abducted and externally rotated position. Three criteria confirmed the location of the electrodes: experience of periosteal pain when the needle reached the costal surface of the scapula, drawing-in of the wires 3-4 cm when the subject adducted his arm, thereby rotating his scapula downward, and raw EMG recorded during typical movements. Additionally, in four shoulders, the electrode location was checked with computed tomography. There were no complications from this technique, and the subjects felt no pain from the fine-wire electrodes during arm movements. We conclude that the described technique is a safe and reliable method of reaching the subscapularis muscle with EMG electrodes.

Adult↗
PubMed1990

Three-dimensional photon radiotherapy planning for laryngeal and hypopharyngeal tumours.

Three-dimensional absorbed dose distributions have been computed for high-energy photon radiation therapy of laryngeal and hypopharyngeal cancers, using a coaxial pair of opposing lateral beams in fixed positions. Treatment plans obtained under various conditions of irradiation are analyzed and compared for a cobalt-60 gamma unit (GAMMATRON S80, Siemens), photon beams from a 6 MV (CLINAC 1800, VARIAN), an 8 MV (SATURNE, CGR) and a 15 MV (MEVATRON 77, Siemens) linear accelerator. Using open fields a somewhat non-uniform and partly insufficient dose in target volume of interest is obtained with all treatment units if sufficient protection of the spinal cord is provided. The x-ray plans are somewhat superior to the cobalt-60 ones. Depending on the quantum energy and wedge isodose angle, wedging only slightly improves or sometimes moderately decreases the homogeneity of the dose in the target volume. According to these small and/or controversial effects of wedges their application seems unnecessary and/or non-convenient. Simulations show that extreme care is needed in positioning the isocentre: an accuracy of +/- 3 mm is required in the median sagittal plane.

Cobalt Radioisotopes↗
PubMed1990

Multi-modality in management of primary malignant non-Hodgkin lymphomas of the central nervous system.

A retrospective study of nine patients with primary malignant non-Hodgkin lymphomas of the central nervous system was carried out with emphasis on treatment results. Detailed investigations before or during the treatment excluded the presence of extraneural malignant lymphoma. The varying radicality of surgery was followed by radiotherapy, with different doses and techniques occasionally with adjuvant drug treatment. Two patients received chemotherapy. Surgical removal and subsequent radiotherapy as well as the histology were almost identical in patients with longer survival. It was tried to evaluate the prognostic influence of different factors on treatment and survival.

Adult↗
PubMed1990

Muscle activity and coordination in the normal shoulder. An electromyographic study.

Muscle activity and coordination in ten shoulders were studied in five healthy subjects using electromyography (EMG) recorded during standardized loaded movements, i.e., flexion, extension, abduction, external rotation, and internal rotation at 0 degrees, 45 degrees, and 90 degrees of abduction. Bipolar surface and intramuscular fine-wire electrodes were used, and the EMG signal was low-pass filtered, full-wave rectified, and time-averaged. Activity from the subscapularis, supraspinatus, infraspinatus, pectoralis major (sternoclavicular part), the anterior, middle, and posterior parts of the deltoid, and the latissimus dorsi was recorded in parallel. In order to allow a comparison of the activity in a subject's different muscles and the activity in specific muscles between different individuals, the EMG was normalized. Muscle activity occurred simultaneously in muscles producing the movement and in antagonistic muscles. Coordination due to muscle contractions plays a significant role in stabilizing the shoulder joint. The infraspinatus, subscapularis, and latissimus dorsi acted as stabilizers during flexion; the subscapularis acted as a stabilizer during external rotation and with the supraspinatus during extension.

Adult↗
PubMed1989

A new psychometric test of attention-related behavior in rats; its validity in the aging process.

The ability to distinguish relevance from irrelevance has been attributed to an attention-related mechanism and may be supposed to be disturbed in aging. The reaction to low electrical stimuli which causes neither pain nor escape behavior was investigated by means of a newly developed test in adult and aged rats. The animals' reaction was classified into two different responses depending on the intensity of the electrical stimuli. The first reaction related to sensitivity, the second reaction contained two components, an orienting response and a cognition-controlled type of discriminative behavior. There was no significant difference between the amperage values of the two reactions in adult rats. With respect to aged rats, the amperage values of both reactions are significantly increased as compared with the adult rats. The sensitivity reaction and the attention-related behaviors diverged considerably. These findings show very precisely that certain behavioral reactions may decline differently or even independently with age indicating different age-related changes in the underlying neuroanatomical systems of attention. The results demonstrate the sensitivity of the test used as a model for studying some types of attention-related mechanisms in the aging process. The use of a relatively simple test of animals' reactivity to sensory stimuli may reveal changes that are critical to understanding not only of the aging brain, but of different types of brain lesions and disorders, as well as of drug treatments.

Aging↗
PubMed1989

3D-location of the L5-S1 fulcrum in relation to the hip.

The purpose of the present study was to measure the three-dimensional distance between the hips and L5-S1 joint in vivo so that this data could then be used in computer programs predicting the load at the lumbosacral joint from posture and anthropometric data. Twenty-one subjects were investigated with computed tomography; consecutive transverse slices were taken from the low-back to proximal thigh, and three-dimensional coordinates were recorded. The distance between the hips and the L5-S1 joint was 122 mm, corresponding to 6.9% and 7.5% of body height for men and women, respectively (P less than 0.05).

Aged↗