Biomedical subjects
Publications and source records attributed to B Prokes.
Epidermoid tumors originating from the brainstem are extremely rare. The authors report a patient with an intraaxial epidermoid tumor of the pons. The tumor involved most of the pons and had a small exophytic component.
Intraparenchymal location of a dermoid tumor is extremely rare, and there are only four reports in the literature. This article presents a patient with a dermoid tumor with trilobulated components; an extra-axial component in the basal frontal/ethmoidal region, and two intra-axial components located in each frontal lobe. In addition, two small fat-density lesions anterior to the component in the left frontal lobe were present, probably due to partial intraparenchymal rupture of the tumor. The pathogenesis of intra-axial locations is still controversial, and this article proposes that in at least some cases intraparenchymal rupture of dermoids can cause intra-axial dermoids.
Bisphosphonates inhibit osteoclastic bone destruction that may be stimulated by myeloma cells. By this way, bisphosphonates carry the potential to lower the number of new pathological fractures, of hypercalcaemic events, and of intensity of bone pain as was published earlier. Clodronate has been administered orally in most clinical studies so far despite of its poor bioavailability from the gastrointestinal tract. The aim of our study was to evaluate bone mineral density (BMD) changes in 34 newly diagnosed multiple myeloma patients regularly treated by 900 mg of clodronate in slow intravenous infusions on an outpatient basis in two-week intervals for at least 24 months. BMD was evaluated by CT scanning every six months. Initial values of trabecular BMD were only about 60 per cent of age- and sex-adjusted healthy population values. Clodronate therapy seemed to preserve BMD within the period of two or three years. This effect was seen not only in patients responding to chemotherapy but even in the small subgroup of patients with persisting active disease. We conclude that the long-term intravenous clodronate therapy may contribute to the preservation of BMD and thus calcium hydroxyapatite in bones in multiple myeloma patients concomitantly treated by chemotherapy. The administration of clodronate should start early in the course of disease, before BMD has been markedly reduced.
Gradient elution reversed-phase high-performance liquid chromatography (RP-HPLC) was used for the determination of compounds occurring during the production of biodiesel from rapeseed oil. Individual triacylglycerols (TGs), diacylglycerols, monoacylglycerols and methyl esters of oleic, linoleic and linolenic acids and free fatty acids were separated in 25 min using a combined linear gradient with aqueous-organic and non-aqueous mobile phase steps: 70% acetonitrile+30% water in 0 min, 100% acetonitrile in 10 min, 50% acetonitrile+50% 2-propanol-hexane (5:4, v/v) in 20 min and 5 min final hold-up. Another method with a non-aqueous linear mobile phase gradient [from 100% methanol to 50% methanol+50% 2-propanol-hexane (5:4, v/v) in 15 min] was used for fast monitoring of conversion of rapeseed oil triacylglycerols to fatty acid methyl esters and for quantitation of residual TGs in the final biodiesel product. Sensitivity and linearity of various detection modes (UV detection at 205 nm, evaporative light scattering detection and mass spectrometric detection) were compared. The individual sample compounds were identified using coupled HPLC-atmospheric pressure chemical ionization mass spectrometry in the positive-ion mode.
Previous studies have yielded conflicting data concerning the value of evoked potential parameters in the assessment of clinical relevance of cervical cord compression in clinically "silent" cases. The aim of this study was to assess the value of somatosensory (SEP) and motor evoked potentials (MEP) in the evaluation and prediction of the clinical course, by means of a 2-year follow-up prospective electrophysiological and clinical study performed in patients with clinically "silent" spondylotic cervical cord compression. Thirty patients with MR signs of spondylotic cervical cord compression but without clinical signs of myelopathy were evaluated clinically and using SEPs and MEPs during a 2-year period. The results of the study showed that SEPs and MEPs documented subclinical involvement of cervical cord in 50% of patients with clinically "silent" spondylotic cervical cord compression. During the 2-year period clinical signs of cervical myelopathy were observed in one-third of patients with entry EP abnormality in comparison with no patients with normal EP tests. Combined SEPs and MEPs proved to be a valuable tool in the assessment of the functional relevance of subclinical spondylotic cervical cord compression. Normal EP findings predict a favourable 2-year clinical outcome.
Biphosphonates are used for the treatment of hypercalcaemia as well as in normocalcaemic patients for the long-term inhibition of malignant osteolytic bone processes. In patients with multiple myelomas treated with biphosphonates in randomized studies a reduction of the number of new osteolytic foci was proved and improvement of the quality of life. The objective of the present study was to evaluate the effect of clodronat on the development of bone density in patients with multiple myeloma. In the study since 1993 27 patients were included. In August 1995 22 patients were evaluated who were treated for more than 12 months with clodronat (Bonefos Leiras). The patients were given clodronat in i.v. infusions (five infusions à 600 mg) in three-month intervals. After six-month intervals the amount of hydroxyapatite in the lumbar vertebrae was evaluated by CT densitometry. Statistical testing of trends of assessed bone density values revealed that not even after two years of the disease a statistically significant reduction of the bone density occurs. Treatment was very well tolerated, gastrointestinal problems were an exception. At the onset of the investigation three patients had symptoms of mild tetany, and a decline of the calcaemia below normal values was recorded. As soon as regular administration of calcium preparations was started during clodronat administration, the calcaemia did not decline below normal levels and enhanced neuromuscular irritability did not develop. Clodronat stabilizes the amount of bone mass, reduces pain and also improves the quality of the patients life. It should be included among standard treatment of patients with multiple myeloma.
The use of bisphosphonates in hypercalcemia is fully accepted, but the long term therapy with bisphosphonates is still controversial. The aim of our study was to evaluate the influence of clodronate on the bone density of myeloma patients. 20 patients were included in the study. A total dose of 3000 mg clodronate was administered in 4 to 6 hourly infusions of 600 mg a day, once in 3 months. The effect of clodronate on bone density was evaluated by CT-densitometry over a period of 6 months. At the beginning of May 1994, 15 patients had completed at least 2 estimations of bone density. The amount of hydroxyapatite had increased in 9 patients, remained unchanged in 1 of them, and decreased in 4 of them during the 6 months. The mean bone density before the administration of clodronate was -2.6 SD (standard deviation of European standard bone density for the respective age and sex). After 6 months of therapy, bone density had increased to -2.3 SD. The mean amount of hydroxyapatite in spongiosa rose from the mean value of 32.71 mg/ml before clodronate administration to 38.91 mg/ml after the 6-month treatment period. The mean increase in calciumhydroxyapatite in trabecular bone mass was 6.2 mg. Clodronate contributed to alleviating bone pain in the majority of patients, but this effect is difficult to evaluate because of other treatment modalities administered concomitantly. The tolerance of clodronate was very good. No impairments of renal function, nor other adverse effects were observed. Only in 2 patients the decrease in calcium concentration caused slight tetania.(ABSTRACT TRUNCATED AT 250 WORDS)
The indication of bisphosphonates in hypercalcemia is fully accepted, the long term therapy with bisphosphonates is still controversial. The aim of our study was to evaluate the influence of clodronate on the bone density of myeloma patients. Twenty patients were included in the study. Clodronate is administered in the total dose of 3,000 mg, which is delivered in 4-6 hour infusions, 600 mg/day, once in tree 3 months. The effect of clodronate on bone density is evaluated by CT-densitometry in a period of 6 months. At the beginning of May 1994, 15 patients had completed at least two estimations of bone density. The amount of hydroxyapatite in these six months increased in 9 patients, in one of them there was no change and in 4 of them decreasing bone density was detected. The mean bone density before the administration of clodronate was -2.6 SD (standard deviation of European standard of bone density for age and sex). After 6 months of therapy the bone density increased to -2.3 SD. The mean amount of hydroxyapatite in spongiosa was raised from the mean value 32.71 mg/ml before clodronate administration to 38.91 mg/ml after the 6 month treatment period. The mean increase in calciumhydroxyapatite in trabecular bone mass was 6.2 mg. Clodronate contributed to the amelioration of bone pain in the majority of patients, but this effect is difficult to evaluate because of other treatment modalities administered concomitantly. The tolerance of clodronate was good. No impairments of renal function or other adverse effects were observed. Only in 2 patients the decrease in calcium concentration caused slight tetania. Therefore close monitoring of the calcium level is recommended and in the case of its decrease below the physiological level peroral substitution of calcium was started.
The response of primary tumor to definitive radiation therapy and treatment related morbidity has been analysed in a group of 35 patients. All of them were treated with 20 MeV photon beam to a total dose of 67 to 71 Gy to the prostate. The effect of radiotherapy to a primary tumor were evaluated by means of repeated CT examination of the tumor volume. A statistically significant tumor regression was found to occur from the sixth month after finishing radiotherapy. The absolute majority of treatment complications was of the first grade. Neither moderate nor severe gastrointestinal or genitourinary complications were recorded. The follow-up data of our patients have confirmed that radiotherapy in localized prostatic carcinoma, when sophisticated techniques are employed, represents highly effective treatment modality which improved the quality of life in patients with prostate cancer.
The authors described and evaluated clinical and CT pictures of five children with persistence of hyperplastic primary vitreous body originating due to regression of embryonal hyaloid vascular system. It becomes clinically manifest especially in leucocoria, reduced globe of the eye, prolonged ciliary processi and the formation of fibrovascular changes behind the lens. CT picture is characterized by a) increased density of vitreous body, b) dense stripes going in retrolental direction and in the course of the Cloquet canal, c) microphthalmus, d) absence of calcifications and e) facultative changes on the lens and anterior chamber. These signs represent an important criterium for differentiating persistence of hyperplastic primary vitreous body from retinoblastoma.
The results of a randomized study on the regression rate of the cervix uteri tumour for a group of 56 patients, investigated during and after radiotherapy with 2 Gy dose of the 252Cf neutron component applied by means of intracavitary therapy at the beginning of the therapeutic cure are presented and compared with the conventional 226Ra therapy. It was found that the tumour regression curve after 252Cf irradiation is significantly steeper than the curve of the control group. The quantitative evaluation of the results regarding the time required for a 50% regression of the original tumour shows that a group of patients treated by 252Cf needs a 27 days' cure in comparison with 40 days' cure for patients treated only by gamma radiation. The regression rate of the irradiated tumours shows a difference of approximately 30% for the treatment using small doses of 252Cf.
A polarographic method was used to follow the changes in oxygenation of a tumour of uterus cervix after intracavital irradiation by 252Cf by a physical dose of 2 Gy, applied at the beginning of a therapeutic cycle of combined radiotherapy. The results reached are compared with the results of tumour oxygenation in the course of a conventional therapeutic procedure. It has become apparent that even after the irradiation of a tumour of uterus cervix by a small dose of gamma-neutron radiation with 252Cf there is, beginning with 2nd week of therapy, a significant reoxygenation of the tumour population. The changes of oxygenation after a conventional irradiation have been less marked and reached, in the 4th week of therapy, only marginally significant increase. Differences in reoxygenation of tumours of uterus cervix were confirmed by analysis of the oxygen test. The importance of tumour reoxygenation after the application of 252Cf source of radiation for facilitation of its regression in a combined treatment with Californium-252 and gamma irradiation is discussed.
The authors compared the results in the regression of uterus cervix tumour after intracavital therapy with gamma-neutron irradiation by 252cf and conventional sources of radiation gamma 226Ra in the course of a combined radiotherapy procedure. On the basis of a randomized study in 20 patients for a group it became obvious that due to the irradiation of the tumour in the initial phase of therapeutic cycle by physical dose 2 Gy of neutron component of 252Cf in the point A there was an increased regression of the tumour process causing in the 6th week since the beginning of the therapy a significant difference in the size of the tumours in both groups of patients. The time period required for 50% tumour reduction from the beginning of the therapy proved to be 23 days in patients treated with the 252Cf nuclide as compared with 48 days in the group of patients after conventional therapy.
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The authors describe an accident leading to penetration of the eye of an 11-year-old boy by an unusual foreign body, and the subsequent diagnosis and treatment. Persistent ocular irritation following a corneal perforation wound, in spite of appropriate treatment, led to the presence of an intraocular foreign body being suspected. The results of radiologic examination, including CT (Siemens Somatom 2), were negative. Only A-scan sonography (Kretztechnik 7002) called attention to the possibility of a foreign body in the vitreous behind the traumatic cataract. Extracapsular extraction was immediately followed by careful removal of very small foreign-body particles from the vitreous. Once the corneal sutures had been removed the irritation decreased. The scanning electron microscope (Cambridge) images of the largest particle showed the foreign bodies to be fragments of a moth (order Noctuideae).
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Explore the source record for details and available documents.
Explore the source record for details and available documents.