The clinical and neuroimaging studies in Holmes tremor.

AIM: Holmes tremor (HT) is a combination of rest, postural and action tremor. A parallel dysfunction of cerebello-thalamic and nigrostriatal pathways seems necessary to produce this kind of tremor. We present the clinical and neuroimaging study verifying that hypothesis. MATERIAL AND METHODS: A total of 10 patients: five male, five female, fulfilling consensus criteria were included. Demographic, clinical and neuroimaging data (MRI = 9; CT = 1, SPECT with the use of 123-I-FP CIT: DaTSCAN in six patients to assess the presynaptic dopaminergic nigrostriatal system involvement, indices of asymmetry for ligand uptake for each striatum were calculated) were analyzed. RESULTS: Hemorrhage was the most frequent etiology and thalamus - the most commonly involved structure. Contrary to the previous reports, the visual assessment did not reveal remarkable interhemispheric differences of DaTSCAN uptake. Quantitative measurements showed only minimal differences. CONCLUSIONS: It is open to debate whether nigrostriatal pathway damage is crucial for the phenomenology of HT. Alternative hypothesis is presented that HT represents the heterogeneous spectrum of tremors with similar phenomenology, but different pathophysiology.

Sentinel node biopsy in patients with breast cancer--evaluation of exposure to radiation of medical staff.

AIM: To measure the absorbed doses of radiation to hands of medical staff performing sentinel node biopsy in breast cancer patients. METHODS: The study was conducted in 2004, during sentinel node biopsies in 13 breast cancer patients (T1/T2N0). Sentinel nodes were identified with the use of combined radiotracer/blue dye technique (lymphoscintigraphy--99mTc on albumin carrier, surgery after 24 h; blue dye; intraoperative detection of gamma radiation). Highly sensitive thermoluminescent dosimeters (TLD) made of LiF were used to assess the absorbed doses of radiation during the procedure. During lymphoscintigraphy and during surgical procedure a total of 57 TLDs was placed on different parts of hands of medical staff. RESULTS: Maximal dose recorded during lymphoscintigraphy by TLDs placed on the hands of the physician injecting the radiotracer was 164 microSv. Mean recorded doses were higher for non-dominant hand, especially for distal parts of the index finger, third finger and thumb. During the surgical procedure, TLDs placed on the hands of medical staff recorded much lower doses of radiation than during lymphoscintigraphy. The highest dose was recorded by TLD placed on the pulp of the dominant hand index finger (22 microSv) of the operating surgeon. Mean doses recorded by TLDs placed on the hands of the operating surgeon ranged from 2 to 8 microSv. The absorbed dose of radiation to hands of the scrub nurse was similar to that absorbed to hands of the operating surgeon. CONCLUSION: The maximum recorded dose during sentinel node biopsy in this study was 2200 times smaller than current 1-year dose limit.

Sites of alkylation of poly(U) by agents of varying carcinogenicity and stability of products.

Several alkylating agents of widely varying reported carcinogenicity (dimethylsulfate, diethylsulfate, ethylmethanesulfonate, methylnitrosourea, ethylnitrosourea and ethylnitrosoguanidine) were reacted with poly(U) at pH values ranging from 4.5 to 7.5. All nucleophilic centers (internal phosphate groups, ribose hydroxyls, and O2, N-3 and O4 sites of the uracil base) were found reactive, though to different extents, at neutrality and in slightly acid solution. The distribution of products is a function of the alkylating agent and pH. The nitroso compounds are more reactive toward oxygens than are dialkylsulfates and alkylalkanesulfonates. The ratio of N : O alkyl products is strongly pH dependent, primarily due to the N-3 being most reactive at the higher pH values, while the diester is most reactive at the lower pH values. The extent of reaction of the O2, O4 or 2'-O or ribose is not greatly affected over the pH range tested. At pH 5.0 alkyl ribophosphotriesters mainly lose alchol to re-form a stable phosphodiester. With increasing OH- concentration, the favored reaction is chain scission at the 3'-O-P bond.

Quantitative bone scintigraphy in patients with hyperparathyroidism.

Laboratory tests, including the determination of parathormone in serum, and x-ray examinations are often of limited value in diagnosing hyperparathyroidism (HPT). In this study, bone scintigraphy was carried out in 15 patients with proven HPT (primary and secondary in patients with chronic renal disease) and 25 normal subjects, to evaluate quantitatively increased bone metabolism. The count density ratios bone to soft tissue (D/S-index) were calculated. In normal, this D/S index averaged 3.66 +/- 0.94 and was significantly (p less than 0.001) different to that of HPT-patients averaging 6.37 +/- 1.64. The quantitative evaluation shows a sensitivity of 73%, a specificity of 100% and an accuracy of 90% for detecting HPT (based on the sample values). Discriminant analysis can be applied to calculate the probability of the presence of HPT (primary and secondary) as a function of the measured D/S index.

Occlusive coronary thrombosis and oral anticoagulants.

The results of post-mortem examination in 173 patients followed over an average period of five and a half years after their initial myocardial infarction are described. These 173 patients were divided into four groups according to whether or not they had received an oral anticoagulant and if so how adequately. An index of coronary and myocardial lesions was established for each heart. Recent occlusive coronary and myocardial lesions was established for each heart. Recent occlusive coronary thromboses were four times less frequent in the group of patients who had received adequate anticoagulant therapy than in the other three groups of patients (p less than 0,001). There was no significant difference between the inadequately treated groups and the untreated group. The recurrences of myocardial infarction were associated in 90 per cent of the cases with a recent occlusive thrombosis in the corresponding coronary artery and were found four times less frequently in the group subjected to effective long-term anticoagulant therapy (p less than 0,001).

Endogenous and exogenous DNA lesions recognized by N-alkylpurine-DNA glycosylases.

The combined action of glycosylases and abasic site-specific endonucleases on damaged bases in DNA results in single strand breaks. In plasmid DNA, as a consequence, the covalently closed circular (ccc) form is converted to the open circular (oc) form, and this can be quantitated by agarose gel electrophoresis. We studied DNA lesions sensitive to E. coli 3-methyladenine-DNA glycosylase II (AlkA) and cloned human N-alkylpurine-DNA glycosylase (ANPG-40) which are known to excise alkylated bases and etheno adducts. pBR322 and pAlk10 plasmids not pretreated with mutagens were cleaved by both glycosylases in the presence of enzymes possessing endonucleolytic activity, which indicates that plasmids contain unknown, endogenously formed adducts. Plasmids pretreated with chloroacetaldehyde, a mutagen forming etheno adducts, exhibited enhanced sensitivity to both glycosylases. Adducts formed by acrolein and croton aldehyde were excised by AlkA, but not by ANPG-40, whereas malondialdehyde adducts were not excised by either glycosylase. Bulky p-benzochinone adducts were not excised by AlkA, however, the plasmid pretreated with this mutagen was incised by endonucleases, possibly without prior generation of an abasic site. These examples show that examination of conformational changes of plasmid DNA can be taken advantage of to study the specificity of N-alkylpurine-DNA-glycosylases.

Miscoding properties of isoguanine (2-oxoadenine) studied in an AMV reverse transcriptase in vitro system.

We have found that isoguanine (iG) can pair with thymine (iG.T) and the non-natural base, 5-methylisocytosine (iG.iCM) during template directed synthesis catalyzed by AMV reverse transcriptase. The ratio of these pairings is about 1:10, irrespectively which of the templates, poly(C,iG) or poly(I,iG) is used. This ratio corresponds to the ratio of 2-OH and 2-keto tautomers in monomer in aqueous solution and apparently it is not influenced by the template context. Our results indicate also that formation of the reverse transcriptase catalyzed base pairs between iG and A, G or C can occur only at a low frequency, comparable to the frequency, of mismatches of.(ABSTRACT TRUNCATED)

Template-directed base pairing of 2-chloro-2'-deoxyadenosine catalyzed by AMV reverse transcriptase.

2-Chloro-2'-deoxyadenine (2CldA) is used for treatment of several lymphoid malignancies. Since this drug is incorporated into DNA, we have undertaken studies on base pairing of 2-chloroadenine (2ClA). 2CldA phosphoramidite was synthesized and used for preparation of 25-mer templates with 2ClA located at site 21 from the 3'-end. Kinetic parameters (Km and Vmax) for the incorporation of deoxynucleoside-5'-triphosphates by AMV reverse transcriptase opposite the 2ClA template, as well as for the extension of 2ClA.T pair, were determined. The efficiency (Vmax/Km) of incorporation of dGTP, dCTP, and dATP opposite 2ClA is at least one order of magnitude lower than opposite unmodified A. The efficiency of incorporation of dTTP opposite 2ClA is about 30-fold lower than opposite A and extension of 2ClA.T pair is 3-fold lower than of A.T pair. From the analysis of the parameters of dTTP incorporation we conclude that formation of 2ClA.T pair is thermodynamically, but not kinetically controlled. The difference in binding energy (deltadeltaG) between 2ClA.T and A.T pairs in the environment of the polymerase active site is 2 kcal/mol. Our results indicate that the presence of 2ClA in DNA slows down replication, but does not lead to base-substitution mutations.

Analogues of formycins A and B: synthesis and some properties of methyl derivatives of 7-amino and 7-keto pyrazolo(4,3-d)pyrimidines.

Starting from the synthesis of 3-propyl-7-ketopyrazolo(4,3-d)pyrimidine (a formal analogue of formycin B), this was converted to the 7-thio derivative, which was aminated to give 3-propyl-7-aminopyrazolo(4,3-d(pyrimidine (a formal analogue of formycin A) and its methylamino derivatives. With the aid of different methylating agents, all four possible ring N-mono-methyl derivatives of the foregoing have been synthesized. Dimethyl derivatives were prepared on a small scale and identified by cross-methylation reactions, spectral properties and chromatographic behaviour. The basic physico-chemical properties of all the foregoing are described, including ultraviolet absorption spectra, spectrophotometrically determined pK values, and the 1H chemical shifts in aqueous medium and/or dimthjyl sulphoxide. The spectral properties of the various analogues indicate that the N6-methyl derivatives exist predominantly in the imino form, in contrast to the predominant amino form of the corresponding analogue from the adenine series, N1-methyladenine, but similar to the fixed imino form of N1-methyl-9-substituted adenines.

Activity of Escherichia coli DNA-glycosylases on DNA damaged by methylating and ethylating agents and influence of 3-substituted adenine derivatives.

Methylating and ethylating agents are used in the chemical industry and produced during tobacco smoking. They generate DNA base damage whose role in cancer induction has been documented. Alkylated bases are repaired by the base excision repair pathway. We have established the repair efficiency of methylated and ethylated bases by various Escherichia coli repair proteins, namely 3-methyladenine-DNA-glycosylase I (TagA protein), which excises 3-methyladenine and 3-methylguanine, 3-methyladenine-DNA-glycosylase II (AlkA protein), which has a broad substrate specificity including 3- and 7-alkylated purines and the formamidopyrimidine(Fapy)-DNA-glycosylase (Fpg protein) repairing imidazole ring-opened 7-methylguanine. The comparison of the Km values of these various enzymes showed that methylated bases were excised more efficiently than ethylated bases. Several 3-alkyladenine derivatives have been synthesized and examined for their ability to inhibit the activity of the various repair proteins. We have shown that 3-ethyl-, 3-propyl-, 3-butyl- and 3-benzyladenine were much more efficient inhibitors of TagA protein than 3-methyladenine. The inhibitory effect was increased with the increase of the size of alkyl-group and IC50 for 3-benzyladenine was 0.4 +/- 0.1 microM as compared to 1.5 +/- 0.3 mM for 3-methyladenine. These compounds inhibited neither the AlkA protein nor human 3-methyladenine-DNA-glycosylase (ANPG protein). Moreover, 3-hydroxyethyladenine did not affect the activity of any of these enzymes. Taken together, these results suggest that hydrophobic interactions are involved in the mechanism of inhibition and/or recognition and excision of alkylated purines by TagA protein.

[Coronary thrombosis and long term anticoagulant treatment. Results of 173 autopsies after myocardial infarction]. / Thromboses coronaires et traitement anticoagulant au long cours Résultats de 173 autopsies après infarctus du myocarde

Report of an anatomical-clinical study concerning 173 patients with an average follow-up period of 5 and 1/2 years after the onset of myocardial infarction. They were subdivided into four comparable groups differing only in the quality of the long-term antivitamin K treatment which was administered. A survey of the coronary artery and myocardial lesions was performed for every heart. Acute occlusive coronary artery thromboses were four times less frequent in the correctly treated group then in the other three groups (p less than 0.001). There was no significant difference between the insufficiently treated groups and the untreated group. Recurrent myocardial infarctions were accompanied in 90 per cent of cases by acute occlusive coronary artery thromboses and were four times less frequent when treatment was efficient (p less than 0.001). These results confirm the part played by coronary artery thrombosis in the aggravation of coronary atherosclerosis and justify the attempts at long-term prophylaxis. The provide the proof that antivitamin K administration, at efficient dosage, maintained for a long time, has a significant influence on the cause of death in these patients, by decreasing the number of coronary artery thrombosis. Long-term anticoagulant treatment, in spite of its haemorrhagic complications and limits, should not be given up until a new efficient treatment is available.

The effect of neighboring bases on miscoding properties of N2,3-ethenoguanine.

The miscoding potential of N2,3-ethenoguanine (epsilon G), one of the carcinogen vinyl chloride adducts to DNA bases, has been examined by copying of poly (A, epsilon G) templates with DNA-dependent RNA polymerase and reverse transcriptase. In contrast to the results previously obtained with poly (C, epsilon G) templates where epsilon G acts as G and A, in poly (A, epsilon G) templates epsilon G acts almost exclusively as A. These results suggest that mutagenic potential of epsilon G in vivo can depend on the nature of neighboring bases.

Pyrimidine homoribonucleosides: synthesis, solution conformation, and some biological properties.

Conversion of uridine and cytidine to their 5'-O-tosyl derivatives, followed by cyanation with tetraethylammonium cyanide, reduction and deamination, led to isolation of the hitherto unknown homouridine (1-(5'-deoxy-beta-D-allofuranosyl)uracil) and homocytidine (1-(5'-deoxy-beta-D-allofuranosyl)cytosine), analogues of uridine and cytidine in which the exocyclic 5'-CH2OH chain is extended by one carbon to CH2CH2OH. Homocytidine was also phosphorylated to its 6'-phosphate and 6'-pyrophosphate analogues. In addition, it was converted, via its 2,2'-anhydro derivative, to arahomocytidine, an analogue of the chemotherapeutically active araC. The structures of all the foregoing were established by various criteria, including 1H and 13C NMR spectroscopy, both of which were also applied to analyses of the solution conformations of the various compounds, particularly as regards the conformations of the exocyclic chains. The behaviour of the homo analogues was examined in several enzymatic systems. Homocytidine was a feeble substrate, without inhibitory properties, of E. coli cytidine deaminase. Homocytidine was an excellent substrate for wheat shoot nucleoside phosphotransferase; while homouridine was a good substrate for E. coli uridine phosphorylase. Although homoCMP was neither a substrate, nor an inhibitor, of snake venom 5'-nucleotidase, homoCDP was a potent inhibitor of this enzyme (Ki approximately 6 microM). HomoCDP was not a substrate for M. luteus polynucleotide phosphorylase. None of the compounds exhibited significant activity vs herpes simplex virus type 1, or cytotoxic activity in several mammalian cell lines.

[Diagnostic value of planar perfusion scintigraphy of the heart using Technetium Tc 99m with methoxy-isobutylisonitrile (MIBI)]. / Wartosc diagnostyczna planarnej scyntygrafii perfuzyjnej miesnia sercowego przy uzyciu wlasnego kompleksu radiotechnetu (99mTc) z metoksyizobutyloizonitrylem (MIBI).

99mTc-MIBI (2 methoxy -isobutylisonitrile) belongs to the new generation of radiopharmaceuticals used for studies of myocardial perfusion. Particularly convenient characteristics of the compound prompted numerous studies of its usefulness for scintigraphic diagnostics of coronary artery disease and myocardial heart infarct (detection, localization, size). In the present paper the diagnostic utility of planar heart scintigraphy with 99mTc MIBI is assessed, the compound had been prepared in the Department of Nuclear Medicine, Medical University of Lódz. The scope of the study included detection of stress induced ischaemia and of permanent perfusion defects, treated as post infarct scars in myocardium. The study was made on 109 patients (78 males, 31 females; age 32-68 years). The first group comprised 56 patients with suspected or diagnosed coronary artery disease, however, without history of previous heart infarct. Results of stress and rest scintigraphy were juxtaposed with those of coronarography, which served as a reference method. In 25 patients the latter revealed critical (greater than 70%) stricture of 1 or 2 coronary arteries. In 31 patients of this group the vessels were either of normal appearance or only marginally stricture. Sensitivity, specificity and accuracy of the scintigraphy in diagnosis of ischaemia due to critical narrowing of coronary arteries amounted to 80, 84 and 82 per cent, respectively. Localisation of perfusion defects was adequate in 20 out of 31 vessels (64 per cent). The second group of patients included 53 individuals with previous heart infarct (25 and 11 had a transmural and nontransmural infarct of the anterior wall, respectively; in 12 and 5 a transmural and nontransmural infarct of the inferior wall was diagnosed, accordingly).(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic efficacy of optimised evaluation of planar MIBI myocardium perfusion scintigraphy: a probabilistic approach.

BACKGROUND: The Bayesian (probabilistic) approach to the results of a diagnostic test appears to be more informative than an interpretation of results in binary terms (having disease or not). The aim of our study was the analysis of the effect of an optimised evaluation of myocardium perfusion scintigrams on the probability of CAD in individual patients. METHODS: 197 patients (132 males and 65 females) suspected of CAD, with no history of myocardial infarction were examined. Scintigraphic images were evaluated applying two methods of analysis: visual (semiquantitative) and quantitative, and the combination of both. The sensitivity and specificity of both methods (and their combination) in the detection of CAD were determined and optimal methods of scintigram evaluation, separately for males and females, were selected. All patients were subjected to coronary angiography. The pre-test probability of CAD was assessed according to Diamond and the post-test probability was evaluated in accordance with Bayes's theorem. Patients were divided, according to a pre-test probability of CAD, into 3 groups: with low, medium and high probability of the disease. The same subdivision was made in relation to post-test probability of CAD. The numbers of patients in respective subgroups, before and after the test, were compared. Moreover, in order to test the reliability of post-test probability, its values were compared with real percentages of CAD occurrence among the patients under study, as demonstrated by the angiography. RESULTS: The combination of visual and quantitative methods was accepted as the optimal method of male scintigram evaluation (with sensitivity and specificity equalling 95% and 82%, respectively) and a sole quantitative analysis as the optimal method of female scintigram evaluation (sensitivity and specificity amounted to 81% and 84%, respectively). In the subgroup of males the percentage of individuals with medium pre-test CAD probability equalled 52 and after the scintigraphic study it decreased to 21 (p < 0.0001). In the subgroup of females it changed from 60 to 43 (p = 0.05). The verification of the values of post-test probability revealed its high concordance with the real frequencies of CAD, with correlation coefficient being 0.98 and the regression line differing only slightly from the line of identity. CONCLUSIONS: The results confirm the high reliability of the values of post-scintigraphic probability of CAD obtained in this way, and support the Bayesian, probabilistic interpretation of the study outcome and its application in the diagnostic process.

Normative values of 99mTc-MIBI distribution in myocardium in males and females, as a basis for quantitative planar scintigraphic method for detection of coronary artery disease in patients of both sexes.

BACKGROUND: Radionuclide perfusion studies of myocardium are being performed using planar and tomographic (SPECT) procedures. The latter method enables better detection as well as assessment of localisation and severity of scintigraphically visualised perfusion defects. On the other hand, lower cost of planar procedures using 99mTc-MIBI as the tracer and their much wider availability in countries of Central and Eastern Europe could significantly increase the diagnostic potential of nuclear cardiology in this region. The aim of the study was an assessment of normal distribution of 99mTc-MIBI in the myocardium and generation of normative basis for quantitative planar scintigraphic procedure, aiming at detection of CAD in patients of both sexes. MATERIAL AND METHODS: The study was based on 250 patients. The reference (control) group consisted of 53 individuals (29 men, 24 women) with the low (< 10%) initial probability of CAD as estimated on basis of Diamond's tables. The second group included 197 patients (132 men, 65 women) with diagnosed CAD or with substantiated suspicion of its presence. In all patients of the latter group coronary angiography was performed and was used as the reference method for assessment of diagnostic efficacy of the scintigraphic procedure. RESULTS: The original own method of acquired data evaluation was based on creation of circumferential profiles of activity and on using the procedure of trend-fitting for obtaining average curves and their dispersion around the mean values. The mean profile curves were obtained for three projections (anterior, LAO 45 degrees and LAO 70 degrees ). These mean curves differed significantly between both sexes. In LAO 45 degrees projection the differences affected mostly the region of the septum and postero-lateral wall of the left ventricle (LV). In LAO 70 degrees projection differences were most pronounced in the antero-septal wall of the LV. CONCLUSION: Sensitivity, specificity and accuracy of CAD detection using the elaborated method, taking into account inter-sex differences, amounted to 86, 87 and 86% respectively in males, and correspondingly 81, 84 and 83% in females. The differences between corresponding indices for two sexes were statistically insignificant. For the whole group of patients the sensitivity, specificity and accuracy was 85, 86 and 85%, respectively.

99mTc-HEPIDA plasma clearance as a diagnostic tool. Total plasma v. specific hepatic clearance.

BACKGROUND: (99m)Tc-HEPIDA total plasma clearance has been used for assessment of hepatic parenchyma damage. However, the radiopharmaceutical used is being partly cleared from plasma also by the urinary tract. As the share of the latter route in total elimination of the compound is not well known, the aim of the study was to investigate the percentage of (99m)Tc-HEPIDA eliminated by the kidneys and by the liver. MATERIAL AND METHODS: To this aim total plasma clearance of the compound and urinary part were determined by the methods employed here in 117 patients and in 16 healthy volunteers. The pure hepatic clearance was calculated as the difference between total plasma and the urinary clearance of (99m)Tc-HEPIDA. RESULTS: The urinary clearance in patients amounted from 2.6 to 78% of total clearance; in the healthy volunteers the corresponding range was from 8.6 to 28%. Pronounced spread of the urinary clearance (coefficient of variation = 35%) and lack of correlation between the urinary and total clearance make it necessary to take account of urinary elimination in each patient in whom reasonably accurate assessment of hepatic clearance is required. CONCLUSION: Further studies on the diagnostic efficacy of pure hepatic clearance and its change with age in healthy patients appear necessary.