Polymorphism of vitamin D3 receptor and its relation to mineral bone density in perimenopausal women

Postmenopausal osteoporosis is the most common metabolic bone disease with important genetic factors. We evaluated the frequency of polymorphism 283G/A of the vitamin D3 VDR gene receptor. The study included 800 women at the postmenopausal (505) and reproductive (295) age. Statistically significant changes, depending on the genotype, were shown.

INTRODUCTION

Postmenopausal osteoporosis is the most common metabolic bone disease of strong genetic origin with population variability determined by the interaction of genetic and environmental factors. Recognition of different genetic variants underlying development of osteoporosis would make it possible to administer individual symptomatic treatment as well as early prophylactics of osteoporosis.

METHODS

The aim of the study was to evaluate the frequency of polymorphism 283G/A of the vitamin D3 VDR gene receptor and assessment of its relations with the clinical parameters of osseous turnover and degree of postmenopausal osteoporosis. The study included 800 women at the postmenopausal (505) and reproductive (295) age throughout the Wielkopolska region in Poland. The postmenopausal group included women with osteoporosis and osteopenia and the healthy ones. Women at the reproductive age were healthy. Frequency of the tested gene polymorphism was evaluated in the group where bone mineral density (BMD) was marked and in the control group.

RESULTS

The obtained test results pointed to correlation of polymorphism VDR 283G/A with the BMD scores for the lumbar vertebrae in women with osteopenia and osteoporosis, therefore the ones at risk of fractures. Vitamin D receptor (VDR) polymorphism correlated with reduced BMD values.

CONCLUSIONS

Polymorphism 283G/A of the vitamin D3 receptor gene has been proved to be the genetic factor of postmenopausal osteoporosis. The polymorphism mentioned above has been proved to be a factor of mineral bone density changes of women.

Placental vascular endothelial growth factor expression in pregnancies complicated by type 1 diabetes

Type 1 diabetes mellitus (T1DM) is still associated with increased risk of severe maternal and foetal complications but their pathomechanism remains unclear.

OBJECTIVES

we investigated the possible role of placental vascular endothelial growth factor (VEGF) and VEGF single nucleotide polymorphisms (SNP) in foetal development in T1DM pregnancies. Sixty seven pregnant women with T1DM and singleton pregnancy were enrolled into the study. Results demonstrated higher expression of placental VEGF in women who delivered neonates with birth weight (NBW)>4000g. No such correlation was found in the overall T1DM group and in women who delivered appropriate for gestational age (AGA) and small for gestational age (SGA) newborns. We also demonstrated a significant correlation between 3(rd) trimester mean blood glucose, HbA1C and placental VEGF. No such correlation was found for the 1(st) and 2(nd) trimesters. Top placental VEGF expression and placental mass were found in women who delivered large for gestational age (LGA) newborns. We also found a statistically significant difference in homozygous and heterozygous frequency variants of VEGF SNPs in study groups. We conclude that the increased placental VEGF together with impaired metabolic control may have a role in stimulating foetal overgrowth in T1DM pregnancy.

Placental leptin and its receptor genes expression in pregnancies complicated by type 1 diabetes

Type 1 diabetes mellitus (T1DM) is still associated with increased risk for severe maternal and fetal complications but their pathomechanism remains unclear. We investigated into possible role of placental leptin (LEP) and its receptor gene (LEPR) in T1DM pregnancies. Fourty nine pregnant women with T1DM and singleton pregnancy were enrolled into the study. Control group consisted of 15 healthy pregnant women in uncomplicated, singleton gestation. We observed higher expression of LEP and LEPR in T1DM placentas in comparison to healthy subjects. We also noticed greater expression of LEP and LEPR in T1DM pregnancies with large for gestational age (LGA) and appropriate for gestational age (AGA) fetuses in comparison to small for gestational age (SGA) diabetic fetuses and controls. We found a significant positive correlation between placental LEP and LEPR expression and neonatal birthweight in overweight T1DM subjects. No such a correlation was found in T1DM subjects with normal weight and controls. We conclude that increased placental LEP and LEPR expression may have a role in stimulating fetal overgrowth in T1DM pregnancy.

The effect of standardized Echinacea purpurea extract on rat cytochrome P450 expression level

It is claimed that application of botanical supplements or herbal medicinal products with synthetic drugs that are cytochrome P450 enzymes substrates may induce significant herb-drug interactions and may alter pharmacotherapy. Echinacea preparations are one of the best selling products in the Europe and their medicinal use is still increasing but data about interactions of Echinacea extract with CYP enzymes are limited. In this study, we have investigated potential influence of standardized Echinacea purpurea extract containing 3.7% polyphenolic compounds on the mRNA expression level of major CYP450 enzymes using animal model. Total RNA was isolated from the rat liver tissue according to the manufacturer's protocol. Complementary DNA was synthesized from a mature mRNA template using reverse transcription. The level of mRNA expression in liver was analyzed by real-time quantitative PCR using specific target primers for CYP450 genes. In this study, it was demonstrated a significant increase of rat CYP2D1 and CYP1A1 expression level by 40% (p = 0.007) and 80% (p = 0.01), respectively. A weak inductory effect of the extract was observed for CYP1A2 by 16% (p > 0.05) compared with the control group. The levels of rat CYP3A1 and CYP3A2 mRNA were reduced by 41% (p < 0.05) and 25% (p = 0.001), respectively. A weak inhibitory effect was observed for CYP2D2 by 15% (p = 0.008) and CYP2C6 by 18% (p = 0.004) after long application of the Echinacea ethanolic extract. CYP2D2 and CYP2C6 activities were also inhibited by extract but in a lesser degree than CYP3A1 activity. Moreover, very little or no inhibition was noted for CYP2E1 both after 3 and 10 days of treatment. Our in vivo data indicate that the Echinacea ethanolic extract can potently inhibit the expression of CYP3A1/2 and can also induce of CYP1A1, CYP2D1. These findings suggest that Echinacea extract may influence the P450-mediated metabolism of different drugs and may initiate chemical carcinogenesis by activation of some compounds to their carcinogenic metabolites.

The significance of C3435T point mutation of the MDR1 gene in endometrial cancer

The P-glycoprotein (P-gp) plays an important role in carcinogen distribution and is connected with cell differentiation and apoptotic processes leading to carcinogenesis. Interindividual differences in P-gp activity could modulate susceptibility to cancer development. The MDR1 gene, coding for P-gp, is highly polymorphic and some mutations modulate P-gp activity. Recently, association between the MDR1 C3435T polymorphism and the cancer susceptibility was shown. We have hypothesized that MDR1 polymorphism could influence endometrial cancer susceptibility. We have matched 198 women with endometrial cancer and 198 controls. An additional group of 488 healthy volunteers was investigated. The MDR1 C3435T polymorphism was tested by LightCycler assay. The distribution of MDR1 3435 genotypes was significantly different between cases and controls (P = 0.006). Genotypes containing at least one 3435T allele were statistically significant more frequent in the endometrial cancer group (86.8% vs 75.2%, OR 2.18, P = 0.004). Our observation suggests that MDR1 C3435T polymorphism is correlated with endometrial cancer susceptibility.

Short and long-term physiological responses of male and female rats to two dietary levels of pre-gelatinized maca (lepidium peruvianum chacon)

OBJECTIVE

The aim of this study is to identify physiological responses of male and female rats to either a short- or long-term administration of two doses of Maca (Lepidium peruvianum) and observe relationships which may exist between groups of hormones and effects mediated by them.

DESIGN

The effect of pre-gelatinized (extruded) organic Maca powder (Maca-GO) was studied on Sprague-Dowley male and female rats (1:1 ratio) receiving two dietary levels of Maca-GO (0.75 g/kg and 7.5 g/kg body weight) and assessed against control during 28 and 90 day laboratory trials on 30 and 60 rats respectively. Blood morphology, biochemistry (hormones, lipids and minerals) and histology of internal organs were determined. Homogenates of skeletal muscles and bones of rats were also analyzed.

RESULTS

Maca-GO has low toxicity (LD=7.5 g/kg) and appears to be safe for short-term and extended use as dietary supplement or as a component of functional dietary and therapeutic preparations. There were different responses of male and female rats to different levels of Maca-GO administered during a short- and a longer-term periodl. When administered at higher dose for extended period of time (90 days), Maca-GO acted as a toner of hormonal processes in adult female rats at increased progesterone and a steady estradiol level, without affecting levels of blood FSH, LH and TSH.

CONCLUSIONS

Obtained results justify further clinical research on use of Maca-GO in sportsmen, physically-active people of both sexes and peri-menopausal women to clarify mechanisms underlaying physiological mode of action of Maca-GO validaet in clinical study on humans. Substantial decrease in blood cortisol levels in a short- and longer-term trial and simultaneous tendency to lower blood ACTH, may indicate antidepressive effect of Maca-GO, which together with reduction in body weight, lowering triglycerides in blood plasma and increasing calcium and phosphorus deposition in bone and muscle tissues is worthy consideration in potential application to women at both, pre- and postmenopausal stage.

Glucose evaluation trial for remission (GETREM) in type 1 diabetes: a European multicentre study

OBJECTIVE

Strict metabolic control during the 1st year of type 1 diabetes is thought to be a key factor for achieving clinical remission. The aims of this study were two-fold: (i) to evaluate the frequency and duration of spontaneous remission (defined according to the parameters issued by the International Diabetic Immunotherapy Group (IDIG)) in a European population of consecutive recent onset type 1 diabetes patients (aged 5-35 years), followed-up for a period of 36 months with a common protocol of intensive insulin therapy and without adjunct immune-intervention; and (ii) to identify the predictive factors for clinical remission.

RESEARCH DESIGN AND METHOD

A total of 189 consecutive patients with newly diagnosed type 1 diabetes according to ADA criteria were recruited in participating centres (Belgium, Czech Republic, Estonia, France, Germany, Hungary, Italy, Poland, Romania, Sweden and Turkey) and followed-up for a period of up to 36 months. In all patients, intensive insulin therapy was implemented consisting of three or four injections of regular insulin daily with NPH insulin at bedtime. Adjustment of insulin dose was made according to a common protocol. Various clinical characteristics (age, gender, severity of presentation, etc.), history (presence of diabetic siblings in the family, etc.) and integrated parameters of metabolic control (HbA(1c), blood glucose, the total insulin dose at hospital discharge adjusted for body weight) were collected.

RESULTS

Twenty-two patients (11.6%) experienced remission. The median duration of remission was 9.6 months and the range was 31 months. There was a wide variation among centres. Logistic regression analysis focused on the centre as the main variable in achieving remission.

CONCLUSION

Remission was shown to be very heterogeneous between centres depending on 'other factors' such as patient care and family awareness of the disease rather than on 'measurable factors' such as sex, age, HbA(1c) and severity of presentation at diagnosis. Using intensive insulin therapy and optimisation of metabolic control, remission occurred in nearly one out of eight patients.

Quantitative determination of MDR1 mRNA expression in peripheral blood lymphocytes: a possible role of genetic polymorphisms in the MDR1 gene

BACKGROUND

P-glycoprotein is a transmembrane efflux pump that extrudes a wide variety of drugs, thereby reducing their intracellular access. In humans, P-glycoprotein is encoded by the MDR1 gene. Recently, several single nucleotide polymorphisms in the MDR1 gene were identified. Moreover, it was postulated that, in addition to the full-length P-glycoprotein, a 'mini' P-glycoprotein was also present in lymphocytes.

MATERIALS AND METHODS

We investigated the effect of the genetic polymorphisms G2677T and C3435T in the MDR1 gene on MDR1 mRNA expression in FACS-sorted peripheral blood CD4+, CD8+, CD19+, and CD56+ cells. MDR1 mRNA expression was determined in 45 healthy individuals using a real-time quantitative RT-PCR.

RESULTS

We detected the highest expression of MDR1 mRNA in CD56+ cells, followed by CD8+ > CD4+ > CD19+ cells. However, genetic polymorphisms of the MDR1 gene failed to affect (P > 0.05) MDR1 mRNA levels in the peripheral blood lymphocytes. Furthermore, the transcript levels for the MDR1 N-terminal half were almost two-fold lower than that of the MDR1 C-terminal half in all cell populations investigated (P < 0.0001).

CONCLUSIONS

An almost two-fold difference in MDR1 C- and N-terminal half expressions supports the presence of mini-P-glycoprotein, an alternatively spliced form of the full-length molecule, in peripheral blood lymphocytes.

Reduced procedural risk for coronary catheter interventions in carriers of the coagulation factor VII-Gln353 gene

OBJECTIVES

We have focused on the role of coagulation factor VII (FVII) Arg353Gln polymorphism as a risk predictor of complications following percutaneous transluminal coronary angioplasty (PTCA), directional coronary atherectomy (DCA), and stenting.

BACKGROUND

The FVII Arg353Gln mutation decreases FVII activity, and presence of the Gln353 allele could be protective against thrombus formation during catheter interventions.

METHODS

A total of 666 consecutive patients with coronary artery disease who had undergone PTCA (n = 280), DCA (n = 104), or stenting (n = 282) were followed up for a 30-day composite end point, which included need for target vessel revascularization, myocardial infarction, and death. The Arg353Gln polymorphism of FVII was determined by PCR/RFLP assay.

RESULTS

Carriers of the Gln353 allele had significantly lower levels of total FVII activity (FVIIc, -20.7%, p < 0.001) and of activated circulating FVII (FVIIa, -32.7%, p = 0.03) compared with Arg353/Arg353. The composite end point occurred in 43 patients: 4 were heterozygous Arg353/Gln353, and 39 were homozygous Arg353/Arg353. The incidence of the composite end point was 2.5% in carriers of the Gln353 allele and 7.7% in Arg353/Arg353 homozygotes (p = 0.013). This corresponds to a 72% risk reduction in carriers of the Gln353 allele (relative risk: 0.28; 95% confidence interval: 0.09-0.81; p = 0.02).

CONCLUSIONS

The Gln353 allele of FVII is associated with substantial risk reduction in adverse events that complicate coronary catheter interventions. With the perspective of active site-blocked activated FVII (FVIIai) as conjunctive medication, the results suggest that the FVII genotype should be taken into due consideration in assessment of FVIIai medication and of its dosage.

[Gestational hypertension (GH) and a1166c polymorphism of angiotensin II type 1 receptor]

INTRODUCTION

Recent studies have suggested an association between genetic background of renin-angiotensin system (RAS) and the pathogenesis of pregnancy induced hypertension (PIH). However, the role of the gene coding for angiotensin II receptor (AT1) polymorphism in PIH is not fully understood, thus the aim of the present study was to determine the frequency of A1166C mutation in women with gestational hypertension (GH) and to establish the role of this polymorphism on the susceptibility to the PIH development.

PATIENTS & METHODS

We have analysed 88 women with PIH and 113 healthy pregnant women as a controls. Genomic DNA was extracted from leucocytes using polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP).

RESULTS

We have detected overrepresentation of mutated homozygous genotypes in the PIH group (11.4% in the PIH versus 2.7% in the controls). Homozygous wild-type genotypes were underrepresented in the PIH group (48.9% in PIH and 56.6% in controls). The frequency of heterozygotes was similar in both groups. Statistically significant overrepresentation of allele with mutation in the PIH group (31.3% in the women with PIH, and 23.0% in the controls) (O.R. = 1.5, p = 0.04) was observed.

CONCLUSION

We suggest that presence of A1166C mutation is a risk factor for the development of PIH.

A1166C polymorphism of the angiotensin II type 1 receptor gene and risk of adverse events after coronary catheter interventions

BACKGROUND

Contradictory reports exist concerning the role of the angiotensin II type 1 receptor A1166C polymorphism as a coronary risk factor. Moreover, it is unknown whether the A1166C polymorphism is associated with thrombotic complications after coronary catheter interventions.

METHODS

We investigated the role of the A1166C polymorphism as a risk factor in 1000 patients with coronary artery disease (CAD) and in 1000 age- and sex-matched controls. A total of 649 patients receiving interventions (270 coronary angioplasty, 102 atherectomy, and 277 stenting) were investigated for a 30-day composite end point including target vessel revascularization, myocardial infarction, or death.

RESULTS

The composite end point was reached by 42 patients (6.5%) without evidence that the C allele was associated with excess procedural risk (odds ratio 0.93; 95% confidence interval 0.79-1.75; P =.82). Further analyses by device failed to show linkage with adverse events complicating coronary angioplasty, atherectomy, and stenting. Moreover, in the entire CAD group (n = 1000), the polymorphism even showed a trend to underrepresentation (odds ratio 0.83; 95% confidence interval 0.69-1. 004, P =.054).

CONCLUSIONS

These results indicate that the A1166C polymorphism neither represents a risk factor for adverse events complicating coronary interventions nor seems to have significant impact on further long-term processes such as development and severity of CAD.

Mutations in the human paraoxonase 1 gene: frequencies, allelic linkages, and association with coronary artery disease

Oxidative damage is a major cause of atherosclerosis. Since human paraoxonase has been postulated as a factor which plays a role in protection from low density lipoprotein oxidation, recent studies have dealt with the impact of hereditary PON1 gene polymorphisms as risk factors for coronary artery disease (CAD). The results from these studies are conflicting. In a case-control study, 1000 Caucasian patients with angiographically confirmed CAD were recruited and matched by age and gender to 1000 control individuals. PON1 mutations in codons 55 and 192 were evaluated by polymerase chain reaction-restriction fragment length polymorphism and allocated to defined haplotypes *1 (55L/192Q), *2 (55L/192R), and *3 (55M/192Q). Frequency of PON1 genotypes without any mutation (PON1*1/*1, wild-type) in CAD cases was 16.9% versus 17.1% in control individuals. PON1*2/*2 showed a frequency of 6.6% versus 7.3% (P = 0.68 compared to wild-type), and PON1*3/3 occurred in 11.8% in CAD cases versus 10.3% among control individuals (P = 0.40). There was also no difference in the distribution of carriers heterozygous for *2 or *3 among cases and control individuals. A haplotype containing both mutations 55M and 192R was not observed. None of the investigated genotypes demonstrated association with early manifestation, severity of disease, acute coronary syndromes, or myocardial infarction. Logistic regression analysis with adjustment for age, gender, diabetes, hypertension, hypercholesterolemia and smoking revealed no evidence of increased coronary risk associated with PON1 genotypes. These results suggest that PON1 polymorphisms are not major genetic determinants of CAD.

Paraoxonase 1 mutations in a Turkish population

Human serum paraoxonase 1 (PON1) catalyzes the hydrolysis of certain organophosphate pesticides and nerve gases and so may alter significantly an individual's susceptibility to the toxicity of these chemicals. Moreover, PON1 hydrolyzes lipid peroxides complexed to low density lipoproteins (LDL) and therefore it was suggested that PON1 may be one of the genes that is involved in the pathogenesis of cardiovascular diseases. Its activity shows interindividual and interethnic variability. At least two mutation sites, namely Gln192Arg (Q/R) and Leu55Met (L/M) were reported responsible for the variations in enzyme activity. The aim of the present study was to determine the frequency of these mutations in Turks and compare the results with other European and Oriental populations. A total of 381 unrelated Turkish individuals were genotyped for Gln192Arg and Leu55Met polymorphisms by PCR-RFLP using AlwI and NlaIII, respectively. Genotype distribution was QQ = 0.49, QR = 0.40, RR = 0.11, and LL = 0.52, LM = 0.39, MM = 0.09. Thus frequencies of high activity alleles R (Arg) and L (Leu) were found as 0.31 and 0.72, respectively. The frequency of these alleles was slightly higher in Turkish subjects than other Caucasian populations but much lower compared to Oriental populations.

A1/A2 polymorphism of glycoprotein IIIa and association with excess procedural risk for coronary catheter interventions: a case-controlled study

BACKGROUND

A five-fold increase in risk of stent thrombosis in carriers of A1/A2 (Leu33Pro) polymorphism of glycoprotein Illa has been described. Whether this increased procedural risk applies to other coronary interventions is unknown. We investigated the role of A1/A2 polymorphism as a putative risk factor.

METHODS

We genotyped 1000 consecutive patients with angiographically confirmed coronary-artery disease and 1000 controls matched for age and sex. 653 of the 1000 patients received interventions (271 coronary angioplasty, 102 directional coronary atherectomy, and 280 stenting) and were assessed for a 30-day composite endpoint of need for target-vessel revascularisation, myocardial infarction, and death.

FINDINGS

The composite endpoint occurred in 41 (6.3%) patients. There was no evidence that the A2 allele was associated with excess procedural risk (relative risk 1.36 [95% CI 0.70-2.70], p=0.37). Nor, in subgroup analyses, did A2 predict events that complicated coronary angioplasty (1.17 [0.40-2.70]), directional coronary atherectomy (1.50 [0.30-8.70]), or stenting (1.45 [0.60-3.50]). Neither heterozygotes (A1/A2) nor homozygotes (A2/A2) were over-represented in any subgroup, including those with acute coronary syndromes, early disease manifestation (age <40 years), and histories of myocardial infarction.

INTERPRETATION

A1/A2 polymorphism is not a major risk factor for 30-day adverse events that complicate coronary angioplasty, directional coronary atherectomy, or stenting. Furthermore, A1/A2 polymorphism has no apparent impact on more chronic processes such as atherogenesis of the coronary arteries.

High frequency of CYP1A1 mutations in a Turkish population

The frequency distribution of four cytochrome P4501A1 (CYP1A1) gene mutations was investigated in 271 Turks from southeast Anatolia by polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) assay. Allelic linkage of those mutations was proven by peptide nucleic acid-mediated PCR clamping. Mutation ml (T6235C) forming an MspI restriction site in the 3'-flanking region occurred with 18.1% frequency (95% confidence interval 14.9-21.6%), m2 (A4889G) leading to an Ile/Val exchange in exon 7 had a frequency of 8.9% (6.6-11.6%), and m4 (C4887A; Thr/Asn-exchange also in exon 7) occurred with 5.7% (3.9-8.0%). T5639C (m3) in the 3'-flanking region was not detected. m2 was exclusively found linked with ml forming allele CYP1A1*2B. The frequency of this allele supposedly at-risk for lung cancer was significantly higher than in Middle European populations, but lower than in the Far East.

Arylamine N-acetyltransferase (NAT2) genotypes in a Turkish population

A group of 303 unrelated Turkish subjects from south-east Anatolia was genotyped for seven NAT2 mutations by polymerase chain reaction-restriction fragment length polymorphism. Genotypes associated with slow acetylation were identified in 57.4% (95%-confidence limits, 51.6%-63.1%). Allele frequencies were NAT2*4 (wild type, 23.1%), *5A (1.3%), *5B (35.6%), *5C (4.8%), *6A (30.5%), *7B (4.5%), and *12A (0.2%). A mutation G191A was not detected. Ambiguous mutation linkages were checked by molecular genetic linkage analysis and DNA sequencing. NAT2-alleles in Turks are similarly distributed as in Middle European ethnicities.

CYP1A1 mutations 4887A, 4889G, 5639C and 6235C in the Polish population and their allelic linkage, determined by peptide nucleic acid-mediated PCR clamping

Mutations in the CYP1A1 gene were investigated in 324 Polish children and adolescents using PCR/RFLP. Mutation T6235C (m1) occurred in 6.6% of alleles (95& confidence limits 4.8%-8.8%); A4889G (m2), 2.2% (1.2%-3.6%); and C4887A (m4), 2.0% (1.1%-3.4%). T5639C (m3) was not detected. Wild-type allele CYP1A1*1 was found in 91.4% (88.9%-93.4%). In all cases of theoretically possible mutation linkages, the novel method of allele specific polymerase chain reaction-clamping mediated by peptide nucleic acids was applied to define allelic allocation. All 14 individuals with an m2 mutation also had m1 on the same allele (CYP1A1*2B). Allele CYP1A1*2A, carrying only m1, appeared in 4.5% (3.0%-6.4%). In the single case of m1/m4, these mutations were placed on distinct alleles. CYP1A1 mutations in the Polish sample tended to be less frequent than in other Caucasian groups.

Homozygous rapid arylamine N-acetyltransferase (NAT2) genotype as a susceptibility factor for lung cancer

The polymorphic arylamine N-acetyltransferase (NAT2) is supposed to be a susceptibility factor for certain malignancies. A phenotyping study in 389 lung cancer patients revealed a similar distribution of rapid and slow acetylators by the caffeine test to that in 657 reference subjects (odds ratio, 1.05; 95% confidence limits, 0.81, 1.36; not significant). A separate group of 155 lung cancer patients was studied by genotyping NAT2 and was compared with a matched reference group of 310 unrelated patients and with 278 healthy volunteers. The NAT2 genotype was characterized by PCR-RFLP at nucleotide positions 191, 282, 341, 481, 590, 803, and 857. For evaluation of nucleotide 341, a 3'-mismatch primer was used. Homozygous wild-type genotypes NAT2*4/*4 were confirmed by DNA sequencing. Genotypes for rapid acetylation amounted to 43.9% among lung cancer and 41.6% among reference patients (odds ratio, 1.10 95% confidence limits, 0.73, 1.65; not significant). Discrimination into homozygous and heterozygous carriers of allele NAT2*4 revealed a distinct over-representation of NAT2*4/*4 genotypes amid lung cancer patients (odds ratio, 2.36; 95% confidence limits, 1.05, 5.32; P = 0.018). Logistic regression analysis considering sex, age, and smoking provided an odds ratio of 3.04 (95% confidence limits, 1.37, 6.75; P = 0.003). Hence, carriers of the NAT2*4/*4 genotype, with its especially high acetylation capacity, are at significantly increased risk to lung cancer.

Determination and allelic allocation of seven nucleotide transitions within the arylamine N-acetyltransferase gene in the Polish population

The frequency of various genotypes of arylamine N-acetyltransferase (NAT2) was investigated in 248 Polish unrelated children. Allele-specific polymerase chain reaction (PCR) was applied for mutation at 341 nucleotide (nt) of NAT2 coding sequence and PCR/restriction fragment length polymorphism for the other mutations. Genotypes coded for slow acetylation in 62.9% (56.6% to 68.9%). The frequency of specific NAT2 alleles was *4 (wild-type), 22.0%; *5A (341C, 481T), 5.2%; *5B (341C, 481T, 803G), 33.1%; *5C (341C, 803G), 6.0%; *6A (282T, 590A), 30.0%; *7B (282T, 857A), 3.4%; and *12A (803G), 0.2%. No mutations were found at 191, 434, and 845 nt. By a molecular-genetic procedure, genotypes *4/*6A were confirmed not to mask *6B/*13 (590A/282T). *6B and *13 were absent in a composite sample representative of 826 alleles (95% confidence limits, 0% to 0.45%). Five cases of genotype-phenotype discrepancy were sequenced and their mutation allocation confirmed; 21 further genotypes were confirmed by sequencing. This first evaluation of NAT2 genes among a Slavic population should provide a basis for clinical and epidemiologic investigations of NAT2 in the Polish population.

The acetylation and oxidation phenotypes in insulin-dependent diabetes mellitus

Polymorphism of the acetylation and oxidation phenotypes in patients with IDDM was evaluated. A greater statistically significant number of fast acetylators in IDDM was found.

Polymorphic arylamine N-acetyltransferase (NAT2) genes in children with insulin-dependent diabetes mellitus

Polymorphic liver arylamine N-acetyltransferase (NAT2; EC 2.3.1.5) has been suggested as a susceptibility factor for both insulin-dependent diabetes mellitus (IDDM) and non-insulin-dependent diabetes mellitus. Previous studies reported an overrepresentation of phenotypically fast acetylators among patients with diabetes. With use of an allele-specific nested polymerase reaction, the NAT2 genotypes were determined in 165 clinically well-controlled patients with IDDM and 107 reference children aged from 3 to 18 years. Wild-type and mutated alleles (mutation 1 diagnosed by presence of cytosine at position 341 instead of thymine; M2 by adenine at 590 instead of guanine, M3 by adenine at 857 instead of guanine) were distributed equally in both groups. Genotypes coding fast acetylation (homozygous wild-type and heterozygous wild-type with one of the mutations) were detected in 40.6% and 36.6% of children with IDDM and reference children, respectively (odds ratio, 1.19; 95% confidence limits, 0.70 to 2.04). In 66 children with IDDM and 54 reference children the NAT2 genotype was checked by conventional sulfamethazine (sulfadimidine) phenotyping. There were only five discrepant cases, indicating that NAT2 genotyping enables correct prediction of NAT2 phenotype in about 95% of tested individuals. The fast acetylator genotype could not be established as a host factor for IDDM susceptibility in children.

Blood levels of alloxan in children with insulin-dependent diabetes mellitus

Alloxan is a well-known and universally used agent for evoking experimental diabetes through its toxic effect on the B cells of the Langerhans islets. In our study, blood levels of alloxan in children with insulin-dependent diabetes mellitus were investigated. The observations were made in 68 children aged 6-15 years and in a control group of 44 healthy children in the same age range. Alloxan levels were estimated spectrophotometrically. The mean level of alloxan in blood from children with insulin-dependent diabetes mellitus was 8.76 +/- 9.64 micrograms/ml and in blood from healthy children was 1.53 +/- 1.10 micrograms/ml. The difference was statistically significant (P < 0.05). The metabolism of alloxan leads to the production of free superoxide radicals which, as is well known, injure cells and cause conditions conducive to the occurrence of diseases from autoimmunity. The results obtained suggest therefore that higher levels of alloxan in diabetic children are of significance in the onset of insulin-dependent diabetes mellitus.

Endogenous drug-like factors in a Polish population

In two hundred and twenty-five healthy volunteers not receiving any treatment the occurrence of drug-like factors in blood serum was studied. The examinations were carried out with the use of the fluorescence-polarization-immunoassay (FPIA)-TDx Abbott. The presence of endogenous phenytoin-like, theophylline-like and cyclosporin-like factors has been demonstrated.