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Biomedical subjects

I Karner

Publications and source records attributed to I Karner.

At least 19 recordsLinked to original sources
PubMed2005

Bone mineral density changes and bone turnover in thyroid carcinoma patients treated with supraphysiologic doses of thyroxine.

The aim of this one-year prospective study was to determine whether longterm thyroxine treatment is a risk factor for elevated bone turnover, loss of bone mass and subsequent development of osteoporosis. Premenopausal women (N = 19), and men (N = 9) suffering from differentiated thyroid gland carcinoma in the mean age of 39.0 +/- 8.0 years and 41.8 +/- 10.0 years were investigated. All of them had undergone a total thyroidectomy and subsequent thyroxine therapy. The duration of the TSH-suppressive therapy prior to the the beginning of our study was 9.4 +/- 6.4 years in the female and 8.1 +/- 6.0 years in the male group. The prospective observation was performed by dual X-ray absorptiometry (DXA) at the spine and the femoral neck and by single-photon absorptiometry (SPA) at the distal radius. Laboratory testings included thyroid hormones T3, T4 and TSH, serum calcium, phosphate and PTH, and urinary calcium and phosphate from spontaneous and 24-hour urine samples. Markers of bone formation (osteocalcin, alkaline phosphatase and PICP) and resorption (Ca/Cr and ICTP) were determined. Statistically significant loss of bone mass was observed only on the distal radius in males (p<0.05). At the lumbar spine and femoral neck, only a minor bone loss was registered in a small number of patients. Almost 50 % of the females showed values above the reference range. In more than 30 % of the females, and smaller number of male patients, ICTP values ranged above the reference range, corresponding to elevated bone turnover. These two variables exhibited a slight correlation with bone density at the measured skeletal areas, mostly considering the male group. The results are a proof that accelerated bone turnover and subsequent bone loss occurs during TSH-suppressive thyroxine therapy. In future prospective studies a prolonged time of observation will be necessary, as well as to increase the number of studied patients, in order to better assess the relative risk of osteoporosis in patients undergoing TSH-suppressive treatment more precisely.

Absorptiometry, Photon↗
PubMed2005

Induction of apoptosis of human tumor cells by a 4,9-diazapyrenium derivative and its affects on topoisomerase-II action.

BACKGROUND: 5,10-Diphenyl-4,9-dimethyl-4,9-diazapyrenium hydrogensulfate (FDAP) is a newly synthesized DNA intercalator with strong antiproliferative activity against various human tumor cells. In this study, FDAP's potential to induce apoptosis in human pancreatic (MIAPaCa-2) and colon (Caco-2) carcinoma cells and its effects on topoisomerase-II activity were investigated. METHODS: Cytotoxicity was analyzed using the MTT assay. Antiproliferative activity was measured using a radioactive precursor incorporation assay. DNA fragmentation was analyzed by agarose gel electrophoresis. Apoptosis was detected using annexin-V fluorescein. To screen the topoisomerase-II-targeted effects of FDAP, cell-free assays were used. RESULTS: FDAP at concentrations of 10 and 1 microM caused a strong cytotoxic effect on MIAPaCa-2 cells, but only a slight effect on WI38 cell viability. Inhibition of the DNA, RNA and protein synthesis of the treated tumor cells was dependent on cell type. The DNA of the treated MIAPaCa-2 cells was fragmented. Phosphatidylserine externalization was detected in both tumor cell lines investigated. FDAP caused generation of DNA strand breaks due to interaction with human topoisomerase-IIalpha. CONCLUSION: 1 microM FDAP caused apoptotic cell death of treated tumor cells. FDAP stimulated topoisomerase-II-mediated DNA cleavage and could be considered a topoisomerase-II poison.

Apoptosis↗
PubMed2003

Croatia has reached iodine sufficiency.

This study was performed in 2002, 6 yr after the introduction of a new regulation on salt iodination with 25 mg KI/kg of salt. The aim of the study was to evaluate whether further significant positive results of improved iodine intake could be observed among schoolchildren in Croatia. A total of 927 schoolchildren of both sexes, aged 6-12 yr, were included in the study. In Croatia, with a population of 4,437,460 the research was implemented in four major geographical regions: the Northwestern, Slavonia, Northern Adriatic and Dalmatian regions. Investigations included randomly selected pupils from regional centers and neighboring smaller towns or villages. The results have revealed that thyroid volumes were within the normal range according to the provisional WHO/ICCIDD reference values for sonographic thyroid volume in iodine-replete school-age children, updated in 2001. A significant improvement in medians of urinary iodine excretion was detected in 2002: from 9 microg/dl in 1991 to 14.6 microg/dl in Zagreb, from 4.3 microg/dl in 1995 to 13.1 microg/dl in Split, from 9.4 microg/dl in 1997 to 14.2 microg/dl in Rijeka and from 13.4 microg/dl in 1997 to 14.7 microg/dl in Osijek. An overall median of 14.0 microg/dl of urinary iodine excretion was detected in Croatian schoolchildren. The control of salt at different levels, from production to consumption, including salt produced in all three Croatian salt plants and imported salt, revealed that Croatian salt is adequately iodized. From severe iodine deficiency before the 1950s, through mild-to-moderate iodine deficiency in the 1990s, Croatia has now reached iodine sufficiency.

Chemical Industry↗
PubMed2003

Anaesthetic implications of anticancer chemotherapy.

In anaesthetic practice we deal with cancer patients who are scheduled for operations on tumours or other manifestations of malignant disease. Those patients are often debilitated and have significant weight loss accompanied with hypoproteinaemia, anaemia and coagulation disorders. Oncological patients usually present to the anaesthetist before tumour disease surgery, but they are also candidates for elective operations (e.g. hernia repair) and urgent/emergency surgery (e.g. trauma, fractures and ileus). Chemotherapeutic agents given to these patients are potentially noxious, can affect the conduct of anaesthesia and, furthermore, may aggravate the patient's condition. In this review the most commonly used cytostatic drug regimens and their common side-effects are listed. Some preclinical studies on anaesthetic and cytostatic drug metabolism and interactions are emphasized, as well as clinically relevant perioperative alterations that may affect anaesthetic management in cancer patients. An anaesthetist may have to modify a routine anaesthetic regimen in cancer patients especially if anticancer chemotherapeutics were given. Clinically silent toxic drug effects may become apparent during operation, trauma or in the early postoperative course in such patients. Altered reactions to commonly used anaesthetics in patients receiving chemotherapeutics and an impaired stress reaction may occur in such patients. Special attention must be drawn to protection against opportunistic infections.

Anesthesia↗
PubMed2002

Ultrasound measurement in defining the regional distribution of subcutaneous fat tissue.

The aim of this research is to determine the significance of ultrasound diagnostics in measuring the thickness of subcutaneous fat tissue as well as to point out sex and age differences in regional distribution of subcutaneous fat tissue. The research included 37 men and 33 women with different body mass indexes. Ultrasound measuring of subcutaneous fat tissue was conducted on 16 measuring points. The thickness of subcutaneous fat tissue measured by ultrasound and estimated proportion of fat tissue obtained by comparative methods coincided mostly on the back side of the upper arm, lower abdominal region in interspinal line and the front side of the forearm. Analysis of the subcutaneous fat tissue distribution indicates that there is more equal accumulation of fat tissue in women than in men. BMI limit value for obesity is not the same for men and women because the point at which abdominal region becomes the main storage of subcutaneous fat in body depends on sex. That BMI value represents the physiological beginning of obesity since it marks the change in distribution pattern of subcutaneous fat tissue in different body regions.

Adipose Tissue↗
PubMed2001

Bone loss in premenopausal women on long-term suppressive therapy with thyroid hormone.

BACKGROUND: The effects on bone metabolism of long-term treatment with thyroid hormone given at suppressive doses have been debated. OBJECTIVE: To determine whether long-term thyroxine therapy in the premenopausal period is a risk factor for the development of secondary osteoporosis and whether women receiving this therapy have increased bone loss during the premenopausal period. PATIENTS AND METHODS: The study enrolled a select group of 19 premenopausal women of mean ages 39 +/- 8 years suffering from differentiated thyroid gland carcinoma. All subjects had undergone total thyroidectomy and subsequently initiated thyroxine suppressive therapy. At the beginning of our study, the women had been on suppressive therapy for 9.4 +/- 6.4 years. Laboratory results were performed to exclud other possible factors for secondary osteoporosis. This prospective study of bone mineral density (BMD) was conducted over a 4-year period on all subjects using the method of dual photon x-ray absorptiometry (DXA) of the spine and the femoral neck and also by the method of single-photon absorptiometry (SPA) of the distal radius. RESULTS: At the beginning of this study, 2 subjects had osteopenia in the spine and 2 had osteopenia in the femoral neck; they had been on suppressive thyroxine therapy for 10 years. Osteopenia in the distal radius was found in 4 subjects. Overall, 8 of the 19 women had osteopenia at the beginning of the study. One year later, after the second BMD measurement, no statistically significant loss of bone mass occurred in any region of the skeleton in any of the patients. However, a review of the individual scores revealed osteopenia in 6 patients at the distal radius; bone loss also occurred at the spine and the femoral neck in several women, but not to the extent that would establish osteopenia. After the 4 years, BMD measurements indicated significant bone loss. CONCLUSION: Our results suggest that women who begin long-term ( ~ 10 years) thyroxine therapy in the premenopausal period can develop osteopenia by the beginning of menopause.

Adult↗
PubMed1999

Insulin-like growth factor family in malignant haemangiopericytomas: the expression and role of insulin-like growth factor I receptor.

Haemangiopericytoma is a rare soft tissue tumour originating from the contractile pericapillary cells. Relatively little is known about its molecular pathogenesis. To address this issue, the insulin-like growth factor family (IGFs) was analysed in 19 tumours collected from a human tumour bank network. Seven of the tumours were associated with severe hypoglycaemia. Of these, six were retroperitoneal and one was located in the leg. 3 out of the 19 tumours (15.8 per cent) were positive for insulin-like growth factor I (IGF I) mRNA and 11 were positive for IGF II mRNA (57.9 per cent). Almost 90 per cent of haemangiopericytomas expressed IGF I receptor (IGF IR) mRNA (17 out of 19), five (26.3 per cent) expressed IGF binding protein 1 (IGF BP1), three (15.8 per cent) expressed IGF BP2, and four (21 per cent) exhibited IGF BP3 mRNA. All of the 14 haemangiopericytomas examined with regard to specific receptor binding were IGF IR positive, ranging from 1.2 to 16.2 per cent. Binding was much higher in IGF I/IGF IR positive tumours (15.3+/-0. 7) than in IGF I negative/IGF IR positive tumours (5.1+/-3.3). The potential role of IGF IR as a growth promoting factor in malignant haemangiopericytoma was studied using antisense oligonucleotides and monoclonal antibody alphaIR3 that specifically inhibit IGF IR synthesis or activity. 10 microM IGF IR antisense oligonucleotides significantly inhibited the growth of haemangiopericytoma cells in culture, by around 50 per cent; monoclonal antibody against IGF IR (alphaIR3) also significantly inhibited proliferation. The data suggest that IGF IR may play an important role in the genesis and progression of malignant haemangiopericytomas.

Adult↗
PubMed1998

Tick-borne encephalitis in eastern Croatia.

92 patients treated for tick-borne encephalitis (TBE) in the Department for Infectious Diseases, University Hospital Osijek, over a 22-year period (1973-1995) were analysed. The patients were mostly forestry workers. The appearance of the disease followed the biological activity of the tick, with the largest number of affected individuals recorded between April and August. TBE in eastern Croatia is a relatively frequent infectious disease, appearing almost every year. In a smaller number (9.8%) of cases the clinical picture was aseptic meningitis, while in the majority of patients (90.2%) it presented as an acute meningoencephalomyelitic form. The course was relatively severe in the majority of the patients analysed, with disturbances of consciousness (32.6%) and transitory neurological signs (61.9%). Three patients died (3.3%) in the early phase of the disease. A monophasic course dominated. The clinical and epidemiological data were compared with the cases described in other parts of Croatia and regional differences were seen in the severity of illness. These variations could be due to the previously hypothesized different virus subtypes, or to some other unknown factors.

Adolescent↗
PubMed1998

Omeprazole, azithromycin and amoxicillin or amoxicillin plus clavulanic acid in eradication of Helicobacter pylori in duodenal ulcer disease.

Treatment with omeprazole (OME), azithromycin (AZI) and amoxicillin (AMO) resulted in encouraging Helicobacter pylori cure rates in pilot and control studies. The aim of this study was to establish whether OME + AZI in combination with either AMO or ACA (amoxicillin plus clavulanic acid) are effective in curing H. pylori infection. A hundred patients with active duodenal ulcer and H. pylori infection were treated with OME (day 1-10: 2 x 40 mg/day, day 11-24: 40 mg/day, day 25-42: 20 mg/day) plus AZI 500 mg/day for the first 6 days. Patients were randomly assigned to either AMO 2 x 1000 mg/day (group A, n = 50) or ACA 2 x 1250 mg/day (group B, n = 50) during the first 10 days of treatment. H. pylori status was determined by urease test and histology before and 6 weeks after completion of therapy. Ninety-five patients completed the study. H. pylori infection was eradicated in 85.4% (41/48) patients from group A (intention-to-treat (ITT) analysis: 82%) versus 91.5% (43/47) patients from group B (ITT) analysis: 86%) (NS). All ulcer had healed after 42 days of omeprazole treatment. Side effects, usually minor, were recorded in 12.5% (group A) and 14.9% (group B) of patients (NS). Therapy had to be discontinued in two patients (one in group A and one group B) only. Ten-days treatment with OME and AZI (for the first 6 days) with AMO or ACA are simple and highly effective regimens to cure H. pylori infection in patients with duodenal ulcer disease.

Adult↗
PubMed1997

Lansoprazole versus omeprazole in the treatment of reflux esophagitis.

To evaluate the therapeutic potential of the newly developed proton pump inhibitor lansoprazole in patients with reflux esophagitis (grade I and II according to Savary Müller criteria), the authors performed a single blind, randomized clinical trial comparing 20 mg omeprazole and 30 mg lansoprazole, involving 60 patients at two clinical hospitals. The treatment period was or 8 weeks, and main efficacy variables were healing of endoscopic changes and relief of reflux symptoms. No significant difference in terms of healing and relief of reflux symptoms was found either after 4 or after 8 weeks of treatment. In conclusion, 30 mg lansoprazole daily was found to be safe and effective therapy comparable to omeprazole in the short-term treatment for reflux esophagitis (grade I and II).

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1997

[Omeprazole and azithromycin with and without metronidazole in the eradication of Helicobacter pylori in duodenal ulcer disease].

This prospective, single blind, randomized study was designed to compare the efficacy and tolerance of two therapeutic schedules for eradication of H. pylori in patients with duodenal ulcer. Patients were randomized into two groups. Group 1 (n = 25) was treated with omeprazole 20 mg each morning for 28 days, azithromycin 500 mg/day for 5 days and metronidazole 3 x 500 mg/day for 5 days. Group 2 (n = 25) was treated with omeprazole 20 mg/day for 28 days and azithromycin 500 mg/day for 5 days. H. pylori status was determined by rapid urease test and histology before and 1, 6 and 12 months after the therapy. After 4 weeks of treatment ulcers healed in 96% (24/25) of patients in the first group and in 92% (23/25) of patients in the second group. One and 12 months after the treatment, eradication of Helicobacter pylori was achieved in 72% (18/25) of patients in the first group and in 64% (16/25) of patients in the second group. In 12 months after the treatment ulcer recurred in 43.7% (7/16) of patients in whom H. pylori was not eradicated and in 2.9% (1/34) of patients with eradicated H. pylori. The side effects were minor and/or transitory and did not require discontinuation of the treatment.

Adult↗
PubMed1996

Current status of endemic goiter in Croatia: the results of a nationwide study (1995).

In the beginning of the nineties, 40 years after introduction of iodine prophylaxis in Croatia, on a basis of a frequent reports coming from general practitioners about the presence of a rather high prevalence of goiter among schoolchildren, a nationwide study was initiated with the aim to determine the real prevalence of goiter in the country. A total of 2856 schoolchildren of both sexes, aged 7-15 years, were included into the study. Investigations were designed in a way to cover most of geographical regions in Croatia and subjects were randomly selected. The prevalence of goiter in schoolchildren was assessed by palpation and in part by ultrasonography of the neck. At the same time urinary iodine excretion was measured and iodine content in salt samples was determined. The results have revealed the persistence of mild endemic goiter in inland parts of Croatia with the prevalence of 6-29% in the age group 7-11 years and those of 10-43% among the age group 12-15 years. The overall goiter prevalence in schoolchildren in Croatia fluctuates from 8% to 35%. Such prevalence, most probably due to less than optimum iodine intake, is unlikely to change until iodine content of the salt is increased from its present level of 10 mg of Kl per kg of salt.

Adolescent↗
PubMed1996

Cor triatriatum dextrum--an unusual variant of triatrial heart.

The present report describes a rare case of triatrial heart, cor triatriatum dextrum in a 31-year-old woman in whom the anomaly was incidentally detected by radionuclide angiocardiography. Subsequent assessment with two-dimensional echocardiography and right heart catheterization confirmed the presence of a membrane subdividing the right atrium into two distinct chambers. To the best of our knowledge, this is the only case in which this cardiac anomaly was demonstrated by radionuclide technique.

Adult↗
PubMed1995

Haemodynamic changes and exercise tolerance in dialysis patients treated with erythropoietin.

The aim of our study was to evaluate cardiovascular function at rest and during exercise in dialysis patients before and after treatment with Epo and to examine the changes in left ventricular mass as the consequence of treatment for anaemia. We applied echocardiography and radionuclide ventriculography at rest and after exercise in our research. Following treatment with Epo there was a decrease in the initially high cardiac output (CO) and cardiac index (CI) from 7.5 to 6.31/min and from 4.3 to 3.61/min/m2 respectively. No changes were noted in mean diastolic (DPB) and mean blood pressure (MBP), as well as the initially increased peripheral resistance index (TPRi) of 2582.3 +/- 2097.3 dyn-s-cm-5.m2. Nevertheless, end-diastolic (EDV) and end-systolic (ESV) volume were significantly decreased (P < 0.05), but the ejection fraction (EF) remained unchanged (73.9%). The decrease in the mean values for left ventricular mass (LVM) was significant only within the subgroup of dialysed patients who initially had larger left ventricular mass (P < 0.01). The functional capacity of the CV system measured during exercise increased from four metabolic equivalents (METs) to 6 METs (P < 0.01). A significant increase in blood volume was also observed following treatment of anaemia. The haemodynamic consequences of Epo therapy for the treatment of anaemia were quite positive. However, we would like to point out certain concerns regarding the dialysed patients with initially lower values for left ventricular mass and cardiac output, since the patients within this group developed left ventricular hypertrophy and an increase in cardiac output.

Adult↗
PubMed1991

Crystal growth of calcium oxalate in urine of stone-formers and normal controls.

In this study, the relative crystal growth rate (Vcr) of calcium oxalate (Caox) and a number of other parameters were determined in 17-h daily (d) and 7-h nocturnal fractions (n) of whole urine from 20 recurrent Caox stone formers (SF) and 29 age-matched male normal controls (NC). Vcr, which was determined by the gel crystallization method (GCM), showed the largest difference between SF and NC among all parameters under investigation. Mean values (+/- SD) obtained for Vcr were: 0.73 +/- 0.58 (SF-d)/0.21 +/- 0.22 (NC-d; P less than 0.001) and 0.63+/- 0.58 (SF-n)/0.24 +/- 0.25 (NC-n; P less than 0.01). Significantly higher concentrations of Ca and lower concentrations of thermodynamic and kinetic effectors of Caox crystal growth were responsible for the higher crystal growth rates observed in SF as compared with NC, i.e., they should be partially causative in Caox urolithiasis. However, other properties of urine or the urinary tract (potentially, crystal agglomeration and adhesion) must be accounted for in the genesis of Caox stones.

Adult↗