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Biomedical subjects

J Dvorák

Publications and source records attributed to J Dvorák.

At least 19 recordsLinked to original sources
PubMed1995

[Surgical therapy of carcinoma of the thyroid gland].

BACKGROUND: Thyroid carcinoma comprises tumours with a wide spectrum of aggressiveness. The method of first choice is surgery, however, views on its extent and technique are frequently controversial. The objective of the present work was to demonstrate and justify the procedure used at the author's department in treatment of this tumour. METHODS AND RESULTS: During 1988-1992 a total of 919 patients with thyroid disease were operated. The female:male ratio was 4.13:1; a benign finding was confirmed in 76.4% and a malignant one in 23.6%. The female:male ratio in patients with a malignant findings was 3.24:1. Most frequently a papillary carcinoma was confirmed--in 59.9%, followed by follicular carcinoma in 23.11%, medullary carcinoma in 7.0%, Hürtle's carcinoma in 4.25%, anaplastic carcinoma in 1.42% and epidermoid carcinoma in 0.47%. Metastases in the thyroid were present in 0.94% and a myeloma or sarcoma both in 0.47%. In retrosternal goitres papillary carcinoma was most frequent (19 patients) followed by follicular (7 patients). As to surgical operations, total thyroidectomy was performed in 47.6%, total lobectomy in 20.3%, subtotal thyroidectomy in 15.1% and subtotal lobectomy in 2.4% of the operated patients. A palliative resection was made in 11.8% and lymphadenectomy in 2.8% patients with a malignant finding on the thyroid gland. Permanent complications (paresis of the recurrent nerve, hypoparathyroidism) occurred in 0.95% of the patients, temporary complications (abscess in the scar, transient hypoparathyroidism, oedema of the vocal cords) in 8.66% of the operations. None of the patients died. CONCLUSIONS: Surgical results and experience of the clinic for nuclear medicine support a radical approach to all types of thyroid carcinoma in adults as well as in adolescents.

Female↗
PubMed1995

Normal motion of the lumbar spine as related to age and gender.

The CA-6000 Spine Motion Analyzer was used to measure the lumbar spine's range of motion (ROM). One hundred and four asymptomatic volunteers were examined to obtain normal values for flexion/extension, lateral bending, and axial rotation. A detailed error analysis was conducted to investigate the inter- and intraobserver reliability of the measurement equipment, the differences between passive and active examination, the effects of stretching exercises before examination, and the diurnal changes related to lumbar spine ROM. Subjects were divided into groups by age and gender. Values for each group were compared with respect to age and gender. The measurements were found to be consistent and repeatable. Stretching exercises were observed to increase ROM. Passive examination was recommended to achieve maximum ROM. ROM was observed to increase during the course of the day. A normative database was established showing significantly decreased motion as age increased, but no gender differences were discovered. The validity of the axial rotation values due to fixation difficulties is questioned.

Adult↗
PubMed1995

Ribosomal RNA multigene loci: nomads of the Triticeae genomes.

The nucleolus organizing regions (NORs) on the short arms of chromosomes 1A(m) and 5A(m) of diploid wheat, Triticum monococcum L., are at the most distal loci in the linkage maps of these two chromosome arms. This distal location differs from the interstitial location of the Nor loci on chromosome arms 1BS of tetraploid Triticum turgidum L. and hexaploid T. aestivum L., 5DS of T. aestivum and diploid Ae. tauschii Coss., and 5HS of barley. Moreover, the barley 5HS locus is at a different location than the 5DS locus. However, other markers, including the centromeres, are colinear. These findings showed that the major Nor loci have repeatedly changed position in the chromosome arms during the radiation of species in the tribe Triticeae without rearrangements of the linkage groups. It is suggested that Nor loci may change position via dispersion of minor loci, that are shown here to exist in the T. monococcum genome, magnification of gene copy numbers in these minor loci, and subsequent deletion of the original major loci. Implications of these findings for the use of rRNA nucleotide sequences in phylogenetic reconstructions are pointed out.

Chromosome Mapping↗
PubMed1995

[What does the radicality of thyroidectomy depend on?].

Reflections on the radicality of thyroidectomy are based on the persisting lack of uniformity as regards terminology, indications and techniques of thyroid surgery. The authors emphasize four basic factors involved in the solution of thyroid diseases: A. respecting the preoperative examination and recommendations of the endocrinologist, B. philosophy of the surgeon and his workplace, C. experience and skill of the surgeon, D. postoperative follow-up and treatment of patients. The necessity of multidisciplinary collaboration emphasized under A is followed under B by a detailed analysis of principles of the workplace as regards indications and technical and tactical aspects. In part C necessary theoretical and personal problems of the thyroid surgeon are summarized. Without careful postoperative check-up examinations and evaluation of the results of operations mentioned under D we cannot speak of radicality of thyroid surgery.

Humans↗
PubMed1994

The value of functional computed tomography in the evaluation of soft-tissue injury in the upper cervical spine.

A functional rotatory computed tomography (CT) study of 423 whiplash patients with cervical spine soft-tissue injury was undertaken to determine its diagnostic value. The results are correlated with previous CT studies on normal subjects, and an evaluation of paradox motion, in which the lower vertebra rotates more than the vertebra immediately superior to it, is given. Asymmetrical left/right rotation reached the pathological value in 36% of the patient population at the level of C0-1. Twice as many patients had hypermobile rotation to the left as compared with the right, perhaps indicating that the right alar ligament is more often damaged in injuries involving the whiplash mechanism. A higher percentage of pathological values for hypermobile rotation was found at the level of C0-1 than at C1-2. Patients exhibiting paradox rotation had a significantly higher amount of rotation to the contralateral side than did those who exhibited no paradox rotation. These findings validate the use of functional rotatory CT in the evaluation of soft-tissue damage of the upper cervical spine resulting from whiplash injury.

Adolescent↗
PubMed1994

[Surgical treatment of large goiters extending into the retrosternal space].

The authors describe the characteristics of primary and secondary goitres reaching as far as the retrosternal space. 154 operations of retrosternal goitres during a five-year period account for 16.7% of all operations of the thyroid gland. The great majority (97.4%) of operations was made from a cervical approach. The authors express also their opinion on sternotomies in these operations; the reasons comprise also extensive goitres which cannot be removed across the upper thoracic aperture where the orientation on the position of major blood vessels is poor, when local invasion of the tumour into the neighbouring tissues is suspected, in some reoperations or when it is necessary to explore the mediastinum to differentiate other lesions. The very rare thoracotomic approach is reserved for large retrosternal goitres located in the posterior mediastinum.

Female↗
PubMed1994

[Artephakic retinal detachment].

The authors investigated the incidence of retinal detachment from a total of 3,802 artephakic eyes in which between September 1988 and June 1993, an intraocular lens was implanted at the First Eye Clinic in Prague. Detachment of the retina occurred in 10 eyes, 9 patients (0.3%). Risk factors for detachment of the retina were loss of the vitreous body during extraction of the cataract, a previous injury, myopia and YAG capsulotomy. Cryosurgery was selected in 76.9%, pars plana vitrectomy with an internal tamponade using silicon oil in 15.4% of the eyes. The retina attached in 92.3%, the visual acuity improved, as compared with the condition before operation of the detached retina, in 58.4% of successfully operated patients. Extracapsular extraction of the lens with implantation of an intraocular lens significantly reduced the incidence of retinal detachment. The prognosis of artephakic retinal detachment is comparable with the prognosis of aphakic retinal detachment.

Cataract Extraction↗
PubMed1993

Duration of pain and muscular adaptations in patients with dysfunction of the cervical spine.

Biopsies of the sternocleidomastoid and omohyoid muscle were taken from 24 patients who underwent arthrodesis for cervical dysfunction of different etiologies. The two muscles, which are involved differently in movements of the head and cervical spine, were investigated histochemically. Muscle fibers were classified as type I, IIA, IIB, or IIC (transitional fibers) according to the pH lability of myofibrillar ATPase and calculated relative distribution. In both muscles, fiber transformations (as evidenced by an increase in the relative amount of type-IIC fibers) were regularly observed within the first 2 years after the onset of the symptoms. The occurrence of the transformation processes was independent of the patient's age and sex and was the same for the different etiologies. Since the overall fiber composition of the muscles remained essentially unchanged, the fiber transformations must occur alternatingly in both directions (from "slow" to "fast" and the reverse). Muscles of patients with a long case history showed no greater signs of fiber transformation. Therefore, fiber transformations in response to cervical dysfunction occur in the initial stage of the disease and involve different types of muscles. The muscles then return to a "stable" condition, independent of the continuation of the dysfunction and the chronic neck pain.

Adaptation, Physiological↗
PubMed1993

Clinical validation of functional flexion/extension radiographs of the cervical spine.

The aim of this study was to determine the clinical validity of functional flexion/extension radiographs of the cervical spine in a defined patient population. Sixty-four adults with functional disorders of the cervical spine underwent passive flexion/extension radiographic examinations. The radiographs were analyzed using a computer assisted method to calculate segmental motion parameters, such as rotations, translations, and centers of rotation. The patients were separated into three groups based on their specific functional disorders, and their motion parameters were compared with those of a healthy population. The three groups consisted of patients with degenerative changes, those with radicular syndrome, and those with whiplash trauma. Most of the patients displayed trends toward hypomobile segmental motion. This trend is displayed more substantially in the groups with degeneration and radicular syndrome. Hypomobility in segmental rotation was significant at C6-C7 for the degenerative and radicular groups. The trauma group showed trends toward hypermobility in the upper and middle cervical levels, and the locations of the centers of rotation were shifted in the anterior direction when compared with those of the healthy population.

Adult↗
PubMed1993

[A multidisciplinary approach in the treatment of endocrine orbitopathy].

Despite the knowledge of immunological mechanisms of Graves-Basedow's disease the pathogenesis of endocrine orbitopathy remains obscure. Apart from the most frequent association with GB disease it may occur also in patients with primary hypothyroidism, Hashimoto's thyroiditis or in rare instances in euthyroid patients not suffering from thyroid disease. Endocrine orbitopathy is a typical example of a disease with a multidisciplinary approach to its diagnosis and treatment. In the submitted paper the authors demonstrate the collaboration of four clinics of the Faculty Hospital when dealing with this problem. Complete or almost complete removal of the thyroid gland leads within 1-4 years to regression of the protrusion of the bulbus by 1 mm. In combination with decompression of the orbit by a modification of Ogura's and Walsh's method improvement of visual acuity by 50% was achieved and the mean value of the exophthalmus diminished by 3.5 mm.

Exophthalmos↗
PubMed1993

[External fixator of the cervical spine--a new diagnostic tool].

Soft tissue injuries of the neck may cause severe long-standing pain. The clinical findings are sparse and the identification of the painful segments with conventional diagnostic tools is often impossible. Temporary segmental external fixation for a soft tissue injury of the cervical spine was performed as a diagnostic procedure in 24 patients. The instrumentation was applied according to the established techniques of the insertion of facet screws in the cervical spine. The segments to be instrumented were evaluated by clinical and radiological findings, such as local pain and increased mobility in the functional X-rays. However, none of these findings were convincing enough to proceed directly to fusion for pain relief. Evaluation of external fixation consisted of alternatively fixing different instrumented segments and having the patients rate their pain on a visual analogue pain scale. External fixation of the suspected segments resulted in marked pain relief, which was recorded subjectively by the visual analogue pain scale in 68% of the patients. The pain relief (8.2 points preoperatively--2.6 points postoperatively on average) could be permanently established by successful fusion of these segments in 17 patients. Four of the patients indicated no relief of pain at the follow-up (12.9 months postoperatively). No fusion was performed in 3 patients in whom the diagnostic procedure with external fixation allowed no conclusion about the painful segment. As it is an invasive procedure, external fixation of the cervical spine should be reserved for cases, in which conventional methods have failed to established a clear diagnosis of segmental instability and conservative therapy could not relieve the symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[The significance of the ultrasound examination in surgery of the thyroid gland].

The authors emphasize the importance of ultrasonographic examination of the thyroid gland for the diagnosis of disease as well as for planning and implementation of the operation. They evaluate the importance of 154 sonographic examinations which were made during the last three years in 545 operations of the thyroid. For the surgeon anatomical parameters of the pathological tissue are important with special emphasis on the relation with surrounding tissues and affection of the lymphatic system. The examination is irreplaceable, in particular in reoperations of the thyroid gland and nodular syndrome.

Humans↗
PubMed1993

[The optimal diagnostic approach in myocardial infarct].

In the submitted review the authors discuss rational criteria for the diagnosis of myocardial infarction, indications for thrombolysis, coronarography and possibly PTCA, the method of indirect (non-invasive) assessment of an occluded coronary artery and the most frequent mistakes in the diagnosis of infarction. Essential examinations in the acute stage of myocardial infarction are: case-history, ECG, CK-MB (possibly echocardiography). For indication of thrombolysis of acute PTCA case-history and ECG (or echocardiography) are sufficient. Indications of early coronarography before discharge from hospital: postinfarction angina pectoris, malignant arrhythmia (except on the first day), haemodynamic instability, evidence of myocardial ischaemia (restricted symptoms) during a maximal load before discharge.

Humans↗
PubMed1992

Cognitive deficits in patients after soft tissue injury of the cervical spine.

Fifty-one patients suffering from soft tissue injury of the cervical spine underwent clinical and psychometric examination. Clinical interview evaluated subjective complaints and formal testing of self-estimated cognitive impairment, divided attention, and speed of information processing. Results indicated at least two different syndromes: 1) the "cervicoencephalic syndrome," characterized by headache, fatigue, dizziness, poor concentration, disturbed accommodation, and impaired adaptation to light intensity; and 2) the "lower cervical spine syndrome," which is accompanied by cervical and cervicobrachial pain. When comparing patients with either of these two syndromes, those suffering from cervicoencephalic syndrome had significantly poorer results when tested for divided attention. Speed of information processing was reduced to a comparable extent in both syndromes. These findings were not related to the length of the post-traumatic interval. Reduced processing of working memory is assumed, which may account for more global cognitive problems as well as secondary neurotic reaction.

Adult↗
PubMed1992

An analysis of errors in kinematic parameters associated with in vivo functional radiographs.

A pair of functional radiographs, taken at each end of the range of motion, are used to determine spinal motions. Graphic construction and computer-assisted methods are available for the radiographic analysis. The later provides many more motion parameters. A study of lumbar spine lateral radiographs was conducted to determine errors in the motion parameters due to spinal level, radiographic quality, and errors in the two digitizing instruments. Significant differences were found in the errors due to the two digitizers when the same radiographic pair was redigitized several times. There were only minimal differences, however, between the digitizers when the radiographic films were remarked and redigitized. The error ranges (2 x SD) for the motion parameters were 1) rotation = +/- 1.25 degrees; 2) translation of the inferior posterior vertebral body corner = +/- 0.86 degrees; and 3) coordinates for the center of rotation = +/- 4.3 mm. Both the spinal level and radiographic quality affected the magnitude of errors in all motion parameters.

Computer Graphics↗
PubMed1992

Neurophysiological evaluation of disorders and procedures affecting the spinal cord and the cauda equina.

Neurophysiological tests that asses afferent or efferent pathways of the spinal cord and of nerve roots are used for clinical diagnosis, intraoperative monitoring, and judgement of prognosis. Most tests can readily be performed in awake subjects, whereas many difficulties arise in anesthetized patients in whom neurophysiological testing is the only way of monitoring functional integrity of neural tissue. The research, therefore, that has been carried out in this field during the past year is of special interest.

Cauda Equina↗
PubMed1992

[Changes in hemostasis in persons exposed to a change in atmospheric pressure].

In eight healthy volunteers--four professional and four amateur divers--in a hyperbaric chamber simulated diving was implemented, corresponding to the most frequently encountered conditions of diving activities in Czechoslovakia. Throughout the trial indicators of haemostasis were investigated. Under the selected model conditions changes of the investigated parameters developed which can be considered indicators of a latent process of disseminated coagulation and the so-called syndrome of silent bubbles.

Adult↗