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Biomedical subjects

J Koller

Publications and source records attributed to J Koller.

At least 37 records · Page 2Linked to original sources
PubMed2000

Whole-body scintigraphy in melanoma patients: comparison of 99Tcm-tetrofosmin and 201Tl.

The aim of this study was to determine the diagnostic value of 99Tcm-tetrofosmin whole-body imaging in comparison to 201Tl scintigraphy in patients with metastatic melanoma. In 27 patients with known or suspected melanoma metastases we performed 201Tl scintigraphy and 99Tcm-tetrofosmin scintigraphy using a 1-day protocol. In five patients with known locoregional metastasis the in vivo uptake kinetics of both radiotracers were compared. The final diagnosis was confirmed by surgical histology in 39 lesions (group I) and computed tomography (CT) and clinical course in 14 lesions (group II). In group I, containing mainly locoregional metastases, 201Tl scintigraphy correctly identified 36 of 39 metastases and 99Tcm-tetrofosmin 35 of 39 resulting in a sensitivity of 92% and 90% respectively. The T/B ratios of 201Tl (1.4-4.0, mean 2.15) were statistically significantly higher in comparison to tetrofosmin (1.3-3.0, mean 1.88). However, both radiotracers showed similar uptake and washout kinetics with a maximum of tracer uptake between 1 and 5 min p.i. In group II, containing mainly cerebral and pulmonary metastases, both methods correctly identified six of 14 metastases resulting in a sensitivity of only 43%. We conclude that the uptake of 99Tcm-tetrofosmin and 201Tl in melanoma metastases is very similar. The T/B ratios with 99Tcm-tetrofosmin are significantly lower than with 201Tl. In locoregional melanoma metastases the sensitivity of tetrofosmin scintigraphy is identical with 201Tl imaging and amounts to 90%. In cerebral and lung metastases the sensitivity of both methods is limited when using whole-body scintigraphy.

Adult↗
PubMed2000

[Detection of melanoma metastases with Tc-99m-tetrofosmin].

AIM: The aim of this study was to evaluate Tc-99m-tetrofosmin whole-body imaging in the detection of metastases in patients with malignant melanoma. METHODS: In 30 patients with suspected melanoma metastases we performed whole body imaging. After administration of about 600 MBq Tc-99m-tetrofosmin dynamic images up to 10 min were performed in 7 patients (1 image per 10 sec) to evaluate the optimal tracer uptake in the metastases. In all patients whole-body images were performed 5-10 min p.i. using an acquisition time of 5 min per image. The final diagnosis was confirmed by surgical histology in 30 lesions, by computertomography and clinical course in the remaining lesions. RESULTS: Out of 64 melanoma metastases 49 were detected using Tc-99m-tetrofosmin scintigraphy (49 rp., 15 fn.). The overall sensitivity for the detection of malignant lesions was 77%. Referring only to the lymph node metastases, the sensitivity was 87% (26 rp.; 4 fn.). The maximal tracer uptake was reached 1 min after injection, with a slow decrease in the following 10 minutes. The size of the lesions ranged between 0.5 and 7.0 cm and the T/B ratios between 1.3 and 3.0 (mean 1.88). CONCLUSIONS: Tc-99m-tetrofosmin whole body imaging is a simple and side-effectless method for the detection of melanoma metastases especially of lymph node metastases. The results are comparable to Tc-99m-sestamibi and Tl-201 scintigraphy.

Adult↗
PubMed2000

Resorption and calcification of chemically modified collagen/hyaluronan hybrid membranes.

The objectives of this study were to characterize collagen/hyaluronan hybrid membrane before and after different chemical crosslinking, as well as to investigate the impact of the treatment method on resorption and calcification processes by in vivo tests. The kinetics study of resorption of collagen/hyaluronan membranes showed that after 28 days the membranes were completely resorbed. The modification of the membranes with glutaraldehyde comparing to the similar modification of pericardial tissue conducts higher calcification. Treatment with hexamethylene diisocyanate together with poly(oxyethylene) improved mechanical properties but the resorption process was similar. Additional treatments with diphenylphosphorylazide and 1-ethyl-3-(3-dimethylamino-propyl) carbodiimide (EDAC) resulted in prolongation of the resorption time. Calcification was suppressed in case of treatment with EDAC.

Administration, Cutaneous↗
PubMed1999

[Use of membranes based on collagen as tissue substitutes].

Collagen, as biocompatible and bioactive non-specific polymer, occupies prominent position in the field of tissue engineering. The advanced biomaterials prefer collagen as a matrix for biodegradable implants as are biosynthetic skin substitutes, tendon and ligament substitutes, but also cartilage. Many studies notice the application of chemically modified collagen membranes for hernia and anastomoses reparations, vascular prosthetic materials, or for collagen tubes used in regeneration of peripheral nerves. Besides of defining main problems of tissue engineering, the paper analyses the developmental tendency of these biomaterials in the world, and compares it with the situation in Slovak Republic.

Biocompatible Materials↗
PubMed1999

Changing pattern of infection in the Bratislava Burn Center.

Infection still remains one of the major problems in burn treatment. The authors investigated the occurrence of burn wound pathogens in burn wound biopsies and/or semiquantitative wound surface off-prints. As the results have shown, trends of a decreased contribution of "classical pathogens", like Staphylococcus aureus and Pseudomonas aeruginosa, to burn wound infections were observed. The role of "other pathogens", like Enterobacter, Acinetobacter, etc., which were quite rare in the past, is on the opposite, increasing. One of the explanations can be the increasing rate of early surgical treatment methods of deep burns. The results were in accordance with similar studies from other burn centres.

Acinetobacter Infections↗
PubMed1998

Detection of melanoma metastases with thallium-201 scintigraphy.

UNLABELLED: Thallium-201 accumulates well in various malignant tumors. The aim of this study was to evaluate the potential of 201Tl imaging in patients with metastatic melanoma. METHODS: Fifty patients with suspected melanoma metastases were studied after intravenous injection of a mean tracer activity of 100 MBq 201Tl-chloride. We took sequence images up to 5 min (15 sec/image) and immediate whole-body images with a double-headed camera and a high-resolution collimator. RESULTS: Of 36 patients with metastatic melanoma confirmed by histopathology, metastases were detected in 28 patients using 201Tl imaging. The tumor-to-background ratio ranged from 2.0 to 4.5 (mean 3.2). There were 8 patients with false-negative findings (sensitivity = 78%). Five false-negative findings were lymph nodes greater than 1.5 cm with tumor-to-background ratios lower than 1.5. Only a few cutaneous metastases smaller than 1 cm could be detected. There was one false-positive finding of an inflamed lymph node. The optimum time for imaging was 2-5 min postinjection. CONCLUSION: These data suggest that 201Tl imaging is an accurate method for the detection of melanoma metastases. The short waiting period after injection, the lack of side effects and the sensitivity of about 80% may qualify this method as a routine investigation in patients with high-risk melanoma.

Adult↗
PubMed1998

Our experience with the use of cerium sulphadiazine in the treatment of extensive burns.

The development of the burn disease with infection as the most important complication represents still a major problem in burn patients. With the introduction of the method of early surgical excision of the Af1p4r with immediate grafting in major burns, improved survival has been achieved, particularly in children. However, especially in adults, early massive excisions did not prove to be of much benefit for survival. In these cases, more-or-less sequential staged excisional procedures have been introduced by many renown burn surgeons. In 1976 Monafo et al. presented the cerium nitrate-silver sulphadiazine cream (CSD) combination for topical therapy. The addition of 2.2% of the rare earth metal cerium salt to silversulphadiazine causes the formation of a relatively hard, yellow, leather-like eschar with excellent resistance to infection and good long-term adherence to the burn wound. This allows the surgeon to perform late tangential excision and immediate autografting thus decreasing the open wound size and the rate of severe infections originating in the burn wound itself. We report our experience with the treatment of 20 patients with deep burns exceeding 20% of the BSA with cerium nitrate-silver sulphadiazine cream compared with a similar group of burn patients treated by silver sulphadiazine cream alone. CSD proved to be safe and effective in the treatment of deep and extensive burns. Its advantages include easy and painless application and removal, turning the necrotic skin to yellow, and a leathery crust with good resistance to infection, thus enabling later, or staged, sequential excisions in cases where early massive excisions are not possible.

Adult↗
PubMed1998

The use of growth hormone in the treatment of extensive burns: a case report.

Growth hormone is an anabolic hormone that causes increased cell growth, positive nitrogen and calcium balance, lipolysis, hyperglycemia, and promotes protein synthesis. Its beneficial effect in burn treatment was proven particularly in children, by Herndon's group. The authors report The case of a 12-year-old boy with an electrical arc burn of 81% of the BSA, 60% of the BSA being full thickness loss. Recombinant human growth hormone (Norditropin, Novo Nordisk) was administered at daily doses of 0.52 i.u./kg starting on day 19 post-burn for 15 consecutive days. The treatment was well tolerated except for mild insulinoresistance, which could be easily corrected by slightly increasing the insulin added to glucose solutions. After 56 days of intensive care treatment and several excision and grafting procedures, the majority of burns were healed.

Body Surface Area↗
PubMed1997

The effect of the method of repeated readings on the reading rate and word recognition accuracy of deaf adolescents.

This study examined the effects of the method of repeated readings (RR), a well-accepted remedial reading technique for improving the reading rate of hearing children, with deaf adolescents. Forty-two students from a midwestern residential school for the deaf were randomly assigned into treatment and control groups. The groups were equivalent with respect to age, level of hearing loss, reading achievement, and mental ability. All subjects read material previously determined to be at their instructional levels. Members of the treatment group were videotaped during the initial reading of an assigned passage, allowed to practice over three 15-minute sessions, then videotaped again during a final reading of the assigned passage. The control group differed only in that it practiced reading material other than the assigned passage. Reading rates and word recognition accuracy were recorded for the initial and final reading of each of five passages. Results indicated that the treatment subjects demonstrated significant improvement between pre- and posttesting regarding reading rate and two measures of word recognition accuracy. The performance of subjects engaged in nonrepetitive reading demonstrated minimal improvement. We discuss applicability of this procedure with a deaf population and implications for future research and practice.

Journal Article↗
PubMed1997

Fluid resuscitation in thermally injured pediatric patients.

More than two-thirds of critical burns in special burn units are children. The burned child continues to represent a special challenge, since resuscitation therapy must be more precise than that for an adult with a similar burn. Children have a limited physiologic reserve and the pediatric fluid replacement therapy is based on the principle of separate calculation of physiological and pathological losses. We have reviewed the most widely accepted pediatric isotonic fluid protocols. All these protocols calculate for replacement of pathological losses with a need of 2 ml/kg/% BSAB (body surface area burn) or 4 ml/kg/% BSAB. We choosed the formulas of two Shriner's Burns Institutes--the Cincinnati and the Galveston Unit as representatives, and calculated the fluid therapy for model burn children weights of 10 kg, 30 kg with 20, 40, 60, 80% BSAB. The results of calculations where compared with physiologic parameters of children. In conclusions we could show, that the 4 ml/kg/% BSAB formulas do replace all theoretically predicted pathophysiologic losses due to burns. However, the 2 ml/kg/% BSAB formulas are more practical as a guideline for resuscitation of pediatric patients because of greater therapeutical range and better clinical response of children threatened by burn shock. It is important to remember that all formulas are only guides to fluid therapy, they should be modified according to individual needs and clinical status of the patient. Only successful restoring and maintaining perfusion pressures leads to optimal oxygenation of injured and noninjured tissues, which promotes spontaneous healing, prevents wound conversion, minimise bacterial colonisation, and prepares the injured areas for early grafting.

Age of Onset↗
PubMed1997

[Selective regional lymphadenectomy in malignant melanoma using a gamma probe].

The accurate excision of the first tumour draining lymph node (sentinel lymph node SLN) can prevent extended surgery intervention in many patients with malignant melanoma. The aim of our study was to test the practicability of the SLN dissection using a gamma probe. In a total of 52 patients, mostly with high-risk melanoma, a selective lymph node dissection was performed. We injected intracutuneously about 50 MBq Tc-99m colloid around the tumour or scar followed by dynamic and late static imaging. The site of SLN was localized with a gamma probe and marked on the skin. This was followed by the dissection of the SLN using the gamma probe. In 51 of 52 patients the SLN could be found intraoperatively using the gamma probe. The SLN contained microscopic metastases in 13 patients (24%). The rate of positive SLN was 40% in patients with high-risk melanoma (Breslow thickness more than 1.5 mm). In case of positive SLN a second surgical intervention with radical lymph node dissection was followed. We conclude that dynamic lymphscintigraphy and the selective lymph node dissection using the gamma probe is a simple and minimally invasive method which can improve the survival probability in patients with micrometastases.

Humans↗
PubMed1996

Three-dimensional echocardiography using a transoesophageal imaging probe. Potentials and technical considerations.

Appreciation of three-dimensional relationships could be useful in cardiac diagnosis, decision making and planning of surgery. However, current ultrasound techniques provide only two-dimensional views. A recently developed echocardiographic computerized tomography unit allows reconstruction of three-dimensional images from a series of transoesophageal slices. To evaluate the potentials and limitations of this technique we performed echo computer tomographic examinations in 104 patients with a total number of 227 scans. All but two patients tolerated the procedure well and no serious complications were encountered. Indications for echo computer tomography included coronary artery disease, valvular heart disease, atrial masses, myocardial infarction, mitral and aortic valve replacement, aortic aneurysm and congenital defects. Most of the anatomical structures could be visualized with the best results obtained for the left atrium, the left ventricular outflow tract and the aortic and mitral valve apparatus. However, a variety of technical factors must be considered to achieve optimal results and to avoid misinterpretation. In 86% of patients the underlying pathology could be visualised by echo-computed tomography, particularly congenital defects such as those of the atrial or ventricular septa, but mitral valve pathologies provided the best results. In these cases three-dimensional imaging led to a better perception and understanding of structural relationships. In conclusion, despite current limitations in data acquisition, processing and computing power, echo computer tomography has the potential to provide relevant information in selected clinical settings.

Aortic Valve↗