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Biomedical subjects

M Kamínek

Publications and source records attributed to M Kamínek.

At least 19 recordsLinked to original sources
PubMed2005

Purification and determination of plant hormones auxin and abscisic acid using solid phase extraction and two-dimensional high performance liquid chromatography.

A method for separation and purification of plant hormones auxin and abscisic acid based on mixed mode reversed-phase anion-exchange solid phase extraction and two-dimensional HPLC was developed. Two-dimensional HPLC in "heart cutting" mode was very efficient in the purification of these two hormones. Its purification power is high enough to allow reliable on-line quantification of both hormones even with non-selective detectors.

Abscisic Acid↗
PubMed2004

[Validity of bone scintigraphy for the diagnosis of periprosthetic complications in hydroxyapatite-coated total hip arthroplasty].

PURPOSE OF THE STUDY: To evaluate the efficacy and usefulness of 99Tc-MDP bone scans for the diagnosis of complications associated with hydroxyapatite- coated total hip prostheses. MATERIAL AND METHODS: 99Tc-MDP bone scans of 42 hips were taken before revision surgery in 41 patients with ABG 1 prostheses. Of these, 26 patients (27 hips) were included in our study on the basis of the following criteria: at least 23 months between the index surgery and scintigraphic examination and the availability of good quality bone scans. The average patients' age at the time of index and revision operations was 45.3 years (range, 32-57; SD, 6.02) and 50.2 years (36-61; SD, 6.01), respectively. The average time between the index surgery and bone scintigraphy was 50.3 months (23-84; SD, 15.9). Two experienced specialists in nuclear medicine, who were unaware of any clinical conclusions, participated in the study. RESULTS: Pre- and intra-operative findings showed aseptic loosening in three cups (3/27, 11 %) and one stem (1/27, 4 %). Four hips were suspected to have an infection on the basis of the positive results of intra-operative culture. In the diagnosis of aseptic loosening, sensitivity, specificity, accuracy, and positive and negative predictive values of bone scintigraphy were 100 %, 57 %, 62 %, 23 %, and 100 %, respectively, for the ABG I cup and 100 %, 52 %, 54 %, 8 %, and 100 %, respectively, for the ABG I stem. These characteristics were 67 %, 96 %, 93 %, 67 %, and 96 %, respectively, for the ABG I cup, when plain X-ray was used for evaluation of aseptic loosening. Specificity, accuracy and negative predictive value of plain X-ray for ABG I stem aseptic loosening were 100 %, 96 %, and 96 %. Bone scintigraphy gave one false positive result of sepsis; on the other hand, none of the four hips with positive intraoperative culture was diagnosed as septic. DISCUSSION: The fact that 99Tc-MDP bone scintigraphy as a method of diagnosing periprosthetic complications has a high sensitivity and a relatively low specificity has often been discussed in the literature. Currently, there are only a few studies on bone scintigraphy investigations of hydroxyapatite-coated prostheses. Some authors report that a slight increase in peri-prosthetic radionuclide activity may persist for up to 8 years which can explain the problematic accuracy of the technique. CONCLUSIONS: 99Tc-MDP bone scintigraphy is an intermediate useful tool for detecting complications of total hip arthroplasty with hydroxyapatite- coating. A negative bone scan almost always suggested the absence of aseptic loosening. However, the value of a positive result was regarded as controversial for the diagnosis of both aseptic and septic complications.

Adult↗
PubMed2001

[Prognostic significance of stress tomographic scintigraphy of myocardial perfusion in diabetic patients].

OBJECTIVE: To assess the prognostic value of SPECT in patients with diabetes (DM) and without DM. METHOD: A total of 366 patients (104 women, 262 men) were examined by T1 +/- 201 or Tc-99m-MIBI SPECT of the myocardium. DM was recorded in 149 patients, 217 patients did not suffer from DM. The SPECT findings were classified as normal and abnormal perfusion (fixed or reversible perfusion defect). A serious cardiac event was defined as sudden cardiac death or non-fatal myocardial infarction. Also angina pectoris requiring revascularization was recorded. RESULTS: During the average investigation period of 24 +/- 7 months we recorded in 147 patients with a normal load perfusion only one non-fatal myocardial infarction and the risk of a serious cardiac event was low: 0.3% per annum in the whole group. A significantly higher incidence of a severe cardiac event, 5.9% per year, was recorded in 219 patients with an abnormal finding on SPECT (10 deaths and 16 non-fatal myocardial infarctions, P < 0.01). On comparison of the frequency of serious cardiac events in groups of patients with and without DM no significant difference was found as regards normal load perfusion of the heart muscle (1.1% vs. 0%, P = NS) even in patients with an abnormal SPECT finding (5.8% vs. 6.1, P = NS). CONCLUSION: SPECT myocardial perfusion makes it possible to stratify the risk in patients with DM similarly as proved previously in non-selected groups. Similarly as in patients without DM normal perfusion in diabetic patients predicts a benign prognosis.

Coronary Circulation↗
PubMed2001

The accuracy of myocardial perfusion SPECT imaging in the evaluation of coronary artery disease in women and men.

BACKGROUND: The purpose of this study is to compare sensitivity, specificity and accuracy of myocardial perfusion SPECT for the detection of coronary artery disease (CAD) in women and men. MATERIAL AND METHODS: 588 patients (455 males and 133 females, 273 after a previous myocardial infarction) underwent stress myocardial perfusion SPECT. The accuracy of myocardial perfusion SPECT was proved by coronary angiography (stenosis > 50% was considered as a CAD). RESULTS: The sensitivity of SPECT was slightly higher, but statistically not significant, in men than in women (94% versus 91%, p > 0.05). The specificity was higher in women than in men (93% versus 82%), but this difference was not statistically significant either (p > 0.05). The accuracy of SPECT was the same for both sexes (92%). In angiographically verified group of patients the selection bias was obvious--patients with CAD dominated (74%) and the fraction of patients with CAD in men's group (83%) was significantly higher than in women's group (50%), p < 0.05. CONCLUSIONS: No significant difference was revealed in the accuracy of myocardial perfusion SPECT in men and women. Our results are in accordance with the prevailing opinion in literature that discovered differences in sensitivity, specificity and diagnostic accuracy are usually not statistically significant or that they can be explained by the selection bias of patients in angiographically verified groups (significantly higher fraction of patients with CAD in men's group).

Journal Article↗
PubMed2000

Prognostic value of myocardial perfusion tomographic imaging in patients after percutaneous transluminal coronary angioplasty.

PURPOSE: The authors assessed the prognostic value of stress myocardial perfusion tomographic imaging (SPECT) in patients with recurrent angina or inconclusive results of exercise electrocardiographic tests after successful percutaneous transluminal coronary angioplasty (PTCA). MATERIALS AND METHODS: After PTCA, 70 patients (54 men, 16 women; 41 after myocardial infarction; mean age, 56 +/- 9 years) underwent TI-201 or Tc-99m sestamibi SPECT studies. SPECT patterns were divided into normal (n = 25), fixed defects (n = 15), and reversible or combined fixed plus reversible defects (n = 30). A cardiac event was defined as either cardiac death, nonfatal myocardial infarction, or unstable angina requiring further revascularization. RESULTS: During an average follow-up of 25 +/- 10 months, two patients had severe outcomes (one cardiac death and one nonfatal myocardial infarction), and revascularization was required in 13 patients. In patients with normal SPECT or fixed defects, the annual event rate was low (1.2%), with only one revascularization. In patients with reversible or combined defects, the annual event rate was significantly greater (22.4%; chi square = 17.32, P = 0.00003). CONCLUSIONS: Normal perfusion or fixed defects predict a benign prognosis in patients after successful PTCA. The presence of stress-induced reversible defects appears to be the best predictor of future cardiac events.

Angina, Unstable↗
PubMed1999

[Myocardial perfusion tomography imaging in patients without prior myocardial infarction--comparison between 201Tl, 99mTc-tetrofosmin and dual-isotope protocol (rest 201Tl/stress 99mTc-tetrofosmin)].

The authors compared retrospectively the diagnostic accuracy of three protocols--201Tl stress-redistribution, 2-day 99mTc-tetrofosmin and the dual-isotope protocol (rest 201Tl/stress99m Tc-tetrofosmin)--for the detection of ischaemic heart disease (IHD) in a total of 115 patients without previous myocardial infarction (IM). 201Tl protocol (group A) was used to examine 43 patients, incl. 15 women, mean age 51 years (38-69 years). The 2-day 99m Tc-tetrofosmin protocol was used to examine 39 patients incl. 12 women, mean age 49 years (30-71 years). The dual-isotope protocol was used in 33 patients, incl. 8 women, mean age 52 years (31-69 years). In all patients coronarography was performed, stenosis of the artery >50% was considered significant for IHD. The sensitivity of the dual-isotope protocol was 95% and 96% resp. and 92% in the 2-day tetrofosmin and 201Tl protocol, (p>0.05). The specificity of the dual-isotope protocol was 82% and 89% resp. and 88% in the 201Tl and 2-day tetrofosmin protocol, (p >0.05). The diagnostic accuracy was 91% in the dualisotope and 201Tl protocol and 92% in the 2-day protocol (p>0.05). No significant difference was revealed in the sensitivity, specificity and diagnostic accuracy for the detection of IHD between different protocols in patients without previous IM.

Adult↗
PubMed1998

[Correlation of SPECT myocardial stress scintigraphy with coronary angiography].

The sensitivity and specificity of a myocardial perfusion single-photon emission tomography (SPECT) for the detection of the coronary artery disease (CAD) was investigated. As a gold standard the coronary angiography was used--the stenosis of the artery by 50% and more was considered as significant for CAD. After performing SPECT studies patients were examined by coronary angiography according to the attending physician's judgement. In the retrospectively created group of 123 subjects (94 males and 29 females, mean age 53 years, range 30-69 years) 55 patients underwent myocardial infarction (MI). The stress was performed using a bicycle ergometer or, in case of patient's inability, an intravenous dipyridamole infusion. Before december 1995 201T1 was used in all patients, after this date only in patients with prior MI with regard to the advantage of this radionuclide for the detection of the ischemic but viable myocardium. Other patients were administered 99mTc-tetrofosmin. In our group of patients we found the high sensitivity of myocardial SPECT of 94.5% 86 (from 91), specificity of 84.4% (27 from 32) corresponding to usually values and the high diagnostic accuracy of 91.9% (113 from 123). Specificity can be impaired by marked attentuation of gamma-rays by overlying soft-tissue structures such as the breast or diaphragm. The artificial imaging of the inferior wall due to the infradiaphragmatic structures represents the most serious problem-there were four false positive findings in our group; further ones in our 99mTc-tetrofosmin studies were avoided by the routine use of the prone position recommended in the literature. The validity of SPECT myocardial perfusion findings should be verified by coronary angiography; however, one must be aware of some questionable points inherent in this comparison.

Adult↗
PubMed1992

Immunodetection and Identification of N-(o-Hydroxybenzylamino)Purine as a Naturally Occurring Cytokinin in Populus x canadensis Moench cv Robusta Leaves.

A highly specific and sensitive enzyme-linked immunosorbent assay (ELISA) was developed for 9-beta-d-ribofuranosyl-N(6)-(o-hydroxybenzylamino)purine [(oOH)[9R]BAP] and structurally related cytokinins. As little as 3 femtomoles of the compound could be detected by this method. Cross-reactivity studies demonstrated the specificity of four polyclonal antibodies for (oOH)[9R] BAP and its free base in preference to a range of natural cytokinins and other purines. After evaluating the method by internal standardization employing [2-(3)H](oOH)[9R]BAP of high specific radioactivity as recovery marker by dilution analyses and by immunohistograms, it was possible to apply ELISA to quantify (oOH)[9R]BAP in plant extracts. In addition to (oOH)[9R]BAP, an unknown cytokinin reacting with the same antibody was detected in high performance liquid chromatography-fractionated extracts of mature Populus x canadensis Moench cv Robusta. The structure of the new compound was determined by gas chromatography-mass spectrometry and finally confirmed by synthesis as N(6)-(o-hydroxybenzylamino)purine.

Journal Article↗
PubMed1983

Quantitative determination of starch, amylose, and amylopectin in plant tissues using glass fiber paper.

Methods for accurate and rapid determination of starch, amylose, and amylopectin in plant tissues are described. They are based on simplified extraction of starch with 32% perchloric acid and selective retention of the starch-iodine complex on a glass fiber disk (Whatman GF/A). The starch on the disk is dissolved in 0.75 M sulfuric acid and estimated with phenol. For amylose and amylopectin determination the starch on the disk is dissolved in perchloric acid, precipitated with ethanol, and retained on a 10-cm glass fiber strip. Both polysaccharides are separated by a chromatographic procedure involving development of the strip in a mixture of ethanol and dimethyl sulfoxide and in dimethyl sulfoxide. The strip is washed in ethanol and stained with iodine or used for polysaccharide quantitation. As little as 5 micrograms of starch or its components present in different amounts of plant material can be estimated.

Amylopectin↗