A Novel Mobile Platform Enhances Motivation and Satisfaction of Academic Teachers

With rising numbers of students, shorter hospital stays and increasing workload of academic teachers, teaching time have become a scarce resource. Thus, optimal preparation by teachers is key for good clinical teaching. Though a lot of teaching duties are performed by residents in Germany, they are not likely to have been educated in didactic techniques. We developed and evaluated a mobile teaching application using the “Learning Toolbox (LTB)” platform (Raycom BV, Utrecht, Netherlands) that was offered to academic teachers for preparation and support during curricular courses at our medical school. Courses were part of the curricula in Anaesthesiology, Emergency Medicine, and Orthopaedic and Trauma Surgery, and course length could vary up to 40 h per week. Information provided by the novel platform included logistic information, learning objectives, and curricula for the individual courses. A basic tutorial on didactic techniques, suggestions for providing feedback and for enhancing students’ participation was also part of the platform.

After one semester, interviews with teachers indicated an increase in overall satisfaction. Residents appreciated didactic aids and content provided for preparation, leading to higher motivation and self-confidence. The more experienced teachers were particularly satisfied with easy access to scheduling, teaching assignments and daily planning. The app increased teachers’ satisfaction with their performance and enabled better integration of teaching in the daily schedule.

Variation in the TEK gene is not associated with asthma but with allergic conjunctivitis

The Tie2 receptor is an important player in angiogenesis. The Tie2 mRNA and protein are abundantly expressed in the lungs and the associated pathway also has an important role in the development and function of the eye. Tie2 is encoded by the TEK gene in humans. Recently, variations in the TEK gene have been found associated with asthma. The objective of the present study was to investigate whether variations in the TEK gene influenced the susceptibility to pediatric asthma and/or associated phenotypes like GINA status, viral- or exercise-induced asthma, allergic asthma, indoor, outdoor, inhalative allergies, IgE and eosonophil levels, allergic rhinitis and allergic conjunctivitis. Three single nucleotide polymorphisms (SNPs, rs3780315, rs581724 and rs7876024) in the TEK gene were genotyped in 1189 unrelated individuals, out of which 435 were asthmatic children and 754 healthy controls. Different types of asthma, allergies and co-morbidities were defined in 320 patients. Among the fully phenotyped 320 asthmatic patients 178 (55.6%) also had allergic rhinitis and 100 (31.3%) had conjunctivitis. Among the rhinitis patients 98 (55.1%) also had conjunctivitis. Two patients had conjunctivitis without rhinitis. The genotyped SNPs showed no association with asthma. However, SNP rs581724 was significantly associated with allergic conjunctivitis in a recessive way (p=0.007; OR=2.3 (1.3-4.4)) within the asthmatic population. The risk remained significant when the whole population (asthmatics and healthy controls) was included in the calculation (p = 0.003; OR = 2.1 (1.3-3.6)). The minor allele of the rs581724 SNP which is associated with the increased risk to conjunctivitis is also associated with reduced Tie2 expression. There was a significant association between SNP rs581724 and the occurrence of allergic conjunctivitis in asthmatic children. If additional studies can confirm the role of the Tie2 pathway in allergic conjunctivitis, it can be a potential novel therapeutic target in the disease.

In interaction with gender a common CYP3A4 polymorphism may influence the survival rate of chemotherapy for childhood acute lymphoblastic leukemia

CYP3A4 has an important role in the metabolisms of many drugs used in acute lymphoblastic leukemia (ALL) therapy; still, there are practically no publications about the role of CYP3A4 polymorphisms in ALL pharmacogenomics. We genotyped eight common single-nucleotide polymorphisms (SNPs) in the CYP3A4 and CYP3A5 genes in 511 children with ALL and investigated whether they influenced the survival of the patients. We involved additional 127 SNPs in 34 candidate genes and searched for interactions with respect to the survival rates. Significant association between the survival rates and the common rs2246709 SNP in the CYP3A4 gene was observed. The gender of the patients and the rs1076991 in the MTHFD1 gene strongly influenced this effect. We calculated new risk assessments involving the gender-rs2246709 interaction and showed that they significantly outperformed the earlier risk-group assessments at every time point. If this finding is confirmed in other populations, it can have a considerable prognostic significance.

Co-morbid mental health conditions in cancer patients at working age--prevalence, risk profiles, and care uptake

OBJECTIVE

This study examined the prevalence of mental health conditions in cancer patients, the role of socioeconomic position in relation to that, and the use of professional mental health care.

METHODS

Prospective cohort with measurements at the beginning of inpatient treatment (baseline) and 3, 9, and 15 months after baseline using structured clinical interviews based on DSM-IV, questionnaires, and medical records.

RESULTS

At baseline, 149 out of 502 cancer patients (30%) were diagnosed with a mental health condition. Prevalence was associated with unemployment (odds ratio [OR] 2.0), fatigue (OR 1.9), and pain (OR 1.7). Of those with mental health conditions, 9% saw a psychotherapist within 3 months of the diagnosis, 19% after 9 months, and 11% after 15 months. Mental health care use was higher in patients with children ≤18 years (OR 3.3) and somatic co-morbidity (OR 2.6). There was no evidence for an effect of sex on the use of mental health care.

CONCLUSION

Few cancer patients with psychiatric disorders receive professional mental health care early enough. If patients are unemployed or if they suffer from fatigue or pain, special attention should be paid because the risk of having a mental health condition is increased in these patients.

Asthma from a pharmacogenomic point of view

Pharmacogenomics, a fascinating, emerging area of biomedical research is strongly influenced by growing availability of genomic databases, high-throughput genomic technologies, bioinformatic tools and artificial computational modelling approaches. One main area of pharmacogenomics is the discovery of new drugs and drug targets with molecular genetic, genomic or even bioinformatic methods; the other is the study of how genomic differences influence the variability in patients' responses to drugs. From a genetic point of view, asthma is multifactorial, which means that the susceptibility to the disease is determined by interactions between multiple genes, and involves important non-genetic factors such as the environment for their expression. In this review, we summarize collective evidence from linkage and association studies that have consistently reported suggestive linkage or association of asthma or its associated phenotypes to polymorphic markers and single nucleotide polymorphisms in selected chromosomes. Genes that have been found implicated in the disease are potential new drug targets and several pharmacological investigations are underway to utilize these new discoveries. Next, we will focus on the inter-individual variability in anti-asthmatic drug responses and review the recent results in this topic.

Histidine decarboxylase deficiency in gene knockout mice elevates male sex steroid production

Histamine is synthesized in cells by histidine decarboxylase (HDC). HDC-deficient knockout (KO) mice lack functional HDC and histamine in the tissues. In the present study we used this in vivo model for studying the role of HDC deficiency in the regulation of male steroid hormone metabolism. In agreement with earlier studies showing the lack of effects of central histamine on the basal secretion of gonadotrope hormones, we found no difference with in situ hybridization in the expression of GnRH in the hypothalamus of wild type and KO mice. The tissue concentrations of testosterone and several androgenic steroids were significantly elevated in the testes but not in the adrenal glands of HDC-KO mice. In contrast, serum estradiol levels failed to show a significant difference between the two groups. The weight of the testes was significantly smaller in both 7-day-old and adult KO mice. The ultrastructure of the adult testis indicated elevated steroid synthesis with more tightly coiled membranous whorls in Leydig cells. The present results suggest that changes in reproductive functions and sex steroid secretion in male HDC-KO mice are not due to altered hypothalamic GnRH expression but are probably related to definite modifications during fetal development of KO mice reinforced later by the lack of the effect of peripheral histamine. This may provide in vivo evidence that peripheral histamine is an important regulatory factor of male gonadal development during embryogenesis and of sex steroid metabolism later in adulthood.

No association between asthma or allergy and the CCR5Delta 32 mutation

AIMS

To investigate whether the presence of the CCR5Delta32 allele was associated with atopy or asthma.

METHODS

A total of 118 children with asthma, 145 children with non-asthmatic, but allergic phenotype, and 303 children without allergic or asthmatic disorders were studied.

RESULTS

There were no significant differences in the frequency of CCR5Delta32, or in the distributions of genotypes between the groups. The relative eosinophil blood count was slightly lower in patients with heterozygous genotype, than in patients with wild type genotype.

CONCLUSION

No association was found between the susceptibility of allergy or asthma and the functional deficient CCR5Delta32 allele.

Increased frequency of the C3*F allele and the Leiden mutation of coagulation factor V in patients with severe coronary heart disease who survived myocardial infarction

The aim of the present study was to compare the frequencies of the F allele of C3 complement component and the Leiden mutation of coagulation factor V in patients with severe coronary heart disease (CHD) who survived myocardial infarction (MI; group A), and those who had no MI in their case history (group B). We have determined the C3 allele frequencies by electrophoresis, and Leiden mutation by PCR in 338 patients with severe CHD and in 490 and 523 healthy controls, respectively. The C3*F allele frequency was significantly (p = 0.006) higher in group A (0.213) that in group B (0.132). A significant (p = 0.045) difference was found between < or = 60-year group A (0.077) and group B (0.029) patients in the frequency of Leiden mutation. These findings indicate that the C3*F allele and the Leiden mutation may be associated with an increased risk of developing myocardial infarction in CHD patients.

Lack of association between atopic eczema/dermatitis syndrome and polymorphisms in the promoter region of RANTES and regulatory region of MCP-1

BACKGROUND

Chemokines play an important role in the pathophysiology of atopic eczema/dermatitis syndrome (AEDS) and allergy. Recently polymorphisms in the promoter region of RANTES (regulated on activation normal T cell expressed and secreted) and in the gene regulatory region of MCP-1 (monocyte chemoattractant protein-1) have been found, which increase the expression of these chemokines. The - 403A allele of the RANTES promoter region was found associated with AEDS in German children. We investigated whether the presence of these polymorphisms was associated with AEDS or allergy in Hungarian children.

METHODS

One hundred and twenty-eight children with AEDS, 102 allergic children without AEDS and 303 children of comparable ages without allergic disorders were screened for genotype with a PCR-based assay.

RESULTS

There were no significant differences in the frequency of these polymorphisms, or in the distribution of genotypes between the groups. The total IgE concentration, the white blood cell count and the blood eosinophil cell count did not differ between the genotypes.

CONCLUSION

In this cohort of Hungarian children there was no association between - 28G, and - 403A alleles in the RANTES promoter, - 2518G polymorphism in the distal regulatory region of the MCP-1 and AEDS, or allergy.

Hepatic regeneration induces transient acute phase reaction: systemic elevation of acute phase reactants and soluble cytokine receptors

The growth factors present during liver regeneration partially overlap with the regulators of the hepatic acute phase response. We analysed the acute phase reaction and changes in soluble cytokine receptors after partial hepatectomy, when tissue injury inducing acute phase reaction and major reduction of liver mass occur simultaneously. Three acute phase proteins and mRNAs were determined by ELISA and northern blot hybridisation in rats. Serum levels of IL-6 and three soluble cytokine receptors (sTNF-alpha R I and II, sIL-6R) were detected by ELIBA or dot-blot assay. Time-course profiles of fibrinogen, alpha(2)-macroglobulin and haptoglobin proteins and mRNA are presented. Elevation of IL-6, soluble TNF-alpha receptors and soluble IL-6 receptor levels were also detected. The time-course of changes in haptoglobin concentration and elevation of soluble cytokine receptors is described by this in vivo experimental system. The results show good correlation with (post)transcriptional activation of immediate and delayed early gene products. These data suggest the involvement of both acute phase proteins and soluble cytokine receptors in the regulation of liver regeneration.

gp130-specific antisense oligonucleotides inhibit IL-6 signal inducing junB mRNA transcription in the human hepatoma cell line, HepG2

The biosynthesis of interleukin-6 receptor (IL-6R) and gp130 in vitro was blocked using specific antisense oligonucleotides (ASO) in HepG2 liver cells and the efficacy of various ASOs was tested on the generation of IL-6-induced junB mRNA. We used three ASOs specific for the IL-6 receptor, three specific for gp130 and a control (nonsense) oligonucleotide specific for epsilon-chain of IgE (not expressing in HepG2 cells). Our data indicate that a gp130-specific ASO, g2, was the most effective blocker of IL-6-induced junB mRNA, whilst the IL-6 receptor ASOs alone were ineffective. The mechanism of gene inactivation by ASO treatment was partially elucidated by demonstration of the loss of gp130 mRNA from cells treated with ASOs showing functional efficacy. Our data may help to design antisense oligonucleotides that are effective in therapy (e.g. as anti-inflammatory agents) in the future.

Polymorphism in the gene regulatory region of MCP-1 is associated with asthma susceptibility and severity

BACKGROUND

Chemokines play an important role in the pathophysiology of asthma and allergy. Recently, polymorphisms in the gene regulatory region of monocyte chemoattractant protein 1 (MCP-1) and in the promoter region of RANTES have been found; these polymorphisms increase the expression of the chemokines.

OBJECTIVE

We investigated whether the presence of the polymorphisms was associated with atopy or asthma and whether these alleles influenced the severity of asthma in affected individuals.

METHODS

Three groups of subjects-160 children with asthma (disease severity being classified according to the Global Initiative for Asthma guidelines, modified for children), 151 children with nonasthmatic but allergic phenotype, and 303 children without allergic or asthmatic disorders-were screened with a PCR-based assay for genotyping.

RESULTS

The frequency of the -2518G polymorphism in the gene regulatory region of MCP-1 was significantly higher in asthmatic children than in controls (P <.001; odds ratio [OR] = 2.0 [1.4-2.6]) and nonasthmatic atopic children (P <.001; OR = 2.0 [1.4-2.9]). The MCP-1 G/G genotype correlated with asthma severity. In asthmatic children, the MCP-1 -2518G allele was also associated with an increased blood eosinophil level. The promoter polymorphisms in the RANTES gene did not have a detectable effect on the susceptibility to asthma or allergy or on the blood eosinophil count.

CONCLUSION

In this cohort of children, there are associations between carrying G at -2518 of the MCP-1 gene regulatory region and the presence of asthma as well as between asthma severity and homozygosity for the G allele. In asthmatic children, the MCP-1 -2518G polymorphism correlated with increased eosinophil levels. This variant of MCP-1 might belong to the predictor gene set for asthma.

Involvement of polymorphisms in the chemokine system in the susceptibility for coronary artery disease (CAD). Coincidence of elevated Lp(a) and MCP-1 -2518 G/G genotype in CAD patients

The central role of chemokines in the pathogenesis of atherosclerosis has been made clear. Recently polymorphisms in the gene regulatory region of MCP-1 and in the promoter region of RANTES have been found, which increase the expression of these chemokines. We investigated the role of these polymorphisms together with the chemokine SDF-1-801A and the chemokine receptors CCR2-64I and CCR5Delta32 mutations in 318 patients with coronary artery disease (CAD) referred to coronary bypass surgery, comparing them with 320 healthy controls. The prevalence of the MCP-1 -2518 G/G homozygotes was significantly higher among CAD patients than among controls (P<0.005; OR=2.2 (95% CI 1.25-3.92). The Lp(a) levels of CAD patients with G/G genotype were significantly higher than those in patients with G/A or A/A genotypes. No CAD patients homozygous for the CCR5Delta32 and CCR2-64I mutations have been found. The genotype distributions of the two alleles deviated from the Hardy Weinberg equilibrium in patients, indicating that the numbers of homozygotes were significantly lower than expected. The MCP-1 -2518G variant in homozygous form appears as a genetic risk factor for severe CAD. This genotype is associated with elevated Lp(a) levels in patients. Individuals homozygous for CCR2-64I or CCR5Delta32 mutations are at reduced risk for severe CAD.

The association of serum lipoprotein(a) levels, apolipoprotein(a) size and (TTTTA)(n) polymorphism with coronary heart disease

BACKGROUND

The association between lipoprotein(a) levels, apolipoprotein(a) size and the (TTTTA)(n) polymorphism which is located in the 5' non-coding region of the apo(a) gene was studied in 263 patients with severe coronary heart disease and 97 healthy subjects.

METHODS

Lp(a) levels were measured by ELISA, apo(a) isoform size was determined by SDS-agarose gel electrophoresis, and analysis of the (TTTTA)(n) was carried out by PCR. For statistical calculation, both groups were divided into low (at least one apo(a) isoform with < or = 22 Kringle IV) and high (both isoforms with >22 KIV) apo(a) isoform sizes, and into low number (<10 in both alleles) and high number of (> or =10 at least one allele) TTTTA repeats.

RESULTS

Lp(a) levels were higher (P=0.007), apo(a) isoforms size < or =22 KIV and TTTTA repeats > or = 10 were more frequent (P=0.007 and 0.01) in cases than in controls. Lp(a) levels were found to be increased with low apo(a) weight in both groups (both P<0.0001). In multivariate logistic regression analysis, only the Lp(a) levels (P=0.005) and (TTTTA)(n) polymorphism (P=0.002) were found to be significantly associated with CHD.

CONCLUSION

Nevertheless, these results indicate that in CHD patients the (TTTTA)(n) polymorphism has an effect on Lp(a) levels which is independent of the apo(a) size.

Frequency of the R3500Q mutation of the apolipoprotein B-100 gene in a sample screened clinically for familial hypercholesterolemia in Hungary

Familial hypercholesterolemia (FH) and familial defective apolipoprotein B-100 (FDB) cause early onset of coronary heart diseases (CHD). According to the recommendations of the international MEDPED program, we tried to find FH cases. We analyzed 73 FH probands and their 304 first-degree relatives. A total of 39 probands were found from the 21000 subjects screened (1:538) from family doctors' registers recording all citizens, while the remaining 34 were derived from screened patients from lipid clinics. In our FH probands, four cases of FDB (R3500Q mutation) were diagnosed with allele-specific PCR, and the mutation was also detectable in five cases out of seven living family members. In the remaining 69 FH families, 156 people were diagnosed clinically with FH, and 31.8% of the males (against 13% of the not clinically diagnosed FH males, P<0.01), and 32.4% of the females (against 13.5% of the not clinically diagnosed FH females, P<0.01) suffered from early onset CHD. The plasma total cholesterol level of the FDB patients, especially in the younger patients, was very close to normal values. Therefore, the FDB patients seem to be under-represented in this type of survey. Because FDB is one of the independent causes of early onset CHD, the R3500Q mutation should be considered in families with a high frequency of cardiovascular diseases.

Histidine decarboxylase expression in human melanoma

Histamine has been implicated as one of the mediators involved in regulation of proliferation in both normal and neoplastic tissues. Histidine decarboxylase, the only enzyme that catalyzes the formation of histamine from L-histidine, is an essential regulator of histamine levels. In this study, we investigated the gene and protein expression of histidine decarboxylase in melanoma. Reverse transcriptase polymerase chain reaction and in situ hybridization studies of WM-35, WM-983/B, HT-168, and M1 human melanoma cell lines both resulted in positive signals for histidine decarboxylase messenger RNA. A polyclonal chicken antibody was developed against human histidine decarboxylase and protein expression was confirmed by western blot analysis of the cell lysates, revealing a predominant immunoreactive band at approximately 54 kDa corresponding to monomeric histidine decarboxylase. Protein expression of histidine decarboxylase was also shown by flow cytometric analysis and strong punctate cytoplasmic staining of melanoma cell lines. Moreover, both primary and metastatic human melanoma tissues were brightly stained for histidine decarboxylase. When compared with the very weak or no reactions on cultivated human melanocytes both western blot and immunohistochemical studies showed much stronger histidine decarboxylase expression in melanoma cells. These findings suggest that expression of histidine decarboxylase is elevated in human melanoma.

Both interferon (IFN)alpha and IFNgamma inhibit histidine decarboxylase expression in the HT168 human melanoma cell line

OBJECTIVE

Histamine plays an important role in a series of processes including inflammation, allergy, gastric acid secretion, neurotransmission, embryogenesis and in various tumours. Histidine decarboxylase (HDC), the enzyme solely responsible for generation of histamine is expressed in many cells including regenerating and tumour cells. HDC expression is regulated by multiple tissue factors, e.g. various cytokines and growth hormones. In this study the effect of interferon alpha and interferon gamma on the expression of HDC and on cell proliferation in vitro on melanoma cell line.

METHODS

We used recombinant human interferon alpha, interferon gamma and human melanoma cell line HT168.

RESULTS

Our data show that both IFNalpha and IFNgamma decreased the HDC mRNA and protein expression, though with dissimilar kinetics. IFNgamma strongly suppresses the proliferation at 72 h, while IFNalpha has a more moderate effect.

CONCLUSIONS

Since previously the inhibitory effect of histamine on gene expression of interferon gamma was detected, a reciprocal inhibition between histamine and IFNgamma is proposed.

C112R, W323S, N317K mutations in the vasopressin V2 receptor gene in patients with nephrogenic diabetes insipidus. Mutations in brief no. 165. Online

Nephrogenic diabetes insipidus (NDI) is a rare, mostly X-linked recessive disorder characterized by renal tubular resistance to the antidiuretic effect of arginine vasopressin. The gene responsible for the X-linked NDI, the G-protein-coupled vasopressin V2 receptor, has been localized on the Xq28 region. In this study we present three NDI families from Hungary with three different missense mutations in the vasopressin V2 receptor gene. After the mutations in the affected probands in each family had been characterized, other family members were screened by restriction enzyme analysis. The N317K and W323S mutations have not been detected previously. The C112R is an already known mutation. The N317K was a de novo mutation in the patient. The C112R and the W323S were found in the mothers of the patients as carriers and in all other patients, but not in the unaffected members of the families. Segregation of the mutations was consistent with the clinically observed symptoms as well as their severity. As conclusion, these findings further evidence that X-linked NDI results from defects in the V2 receptor gene.

Interleukin-6-induced production of type II acute phase proteins and expression of junB gene are downregulated by human recombinant growth hormone in vitro

Growth hormone (GH), given therapeutically in many human diseases, is able to modulate the maturation and function of many cells of immune system. The present study demonstrates the effect of human recombinant GH on the production of acute phase proteins (APP) as well as on the gene expression of junB proto-oncogene on human hepatoma cell line, HepG2. When applied alone GH resulted in an increase in the transcription of junB proto-oncogene within 30 min. The production of alpha2-macroglobulin, haptoglobin and fibrinogen was also enhanced by rhGH treatment. However, both IL-6-stimulated junB gene expression (junB mRNA) and biosynthesis of type II APP (alpha2-macroglobulin, fibrinogen, haptoglobin) were strongly inhibited by the GH. The results indicate that GH has a modulatory role in regulating inflammation both in the absence and presence of IL-6. These findings call for further in vivo studies to determine the potential anti-inflammatory actions of GH therapy.

Influence of apolipoprotein E genotypes on serum lipid parameters in a biracial sample of children

The goals of this study were to compare the allelic distribution of the apolipoprotein E(apoE) gene in Hungarian and Hungarian Gypsy children and to examine the impact of apoE polymorphism on quantitative levels of lipids in the two racial groups. Our data yielded calculated allele frequencies of 6.4% and 8.9% for apoE2; 83.8% and 73.8% for apoE3; and 9.8% and 17.3% for apoE4 in Hungarian and in Gypsy children, respectively. The frequency of the apoE4 allele was significantly higher (P<0.05) in Gypsy children than in Hungarians. The effect of apoE genotypes on serum lipid parameters differed considerably in the two racial groups. In the Gypsy group the lowest total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C) and triglyceride levels were in the E3/E3 group and these values differed significantly (P<0.0001 for TC and LDL-C and P<0.01 for triglyceride) from the values in the E2/E3 and E3/E4 groups. There were no significant differences in TC, LDL-C and triglyceride levels between E2/E3 and E3/E4 groups. The high-density lipoprotein-cholesterol (HDL-C) levels did not differ significantly among the genotype groups. In Hungarian children, the apoE2/3 group displayed lower, the E3/4 group higher, values of TC and LDL-C than in the E3/3 group, but the differences were not significant (P>0.05). HDL-C and triglyceride values did not differ among the genotype groups.

CONCLUSION

Our results demonstrate that the apolipoprotein E allele frequencies differ between Hungarian and Gypsy children and suggest that these alleles influence the serum lipid levels, but other genetic and environmental factors can considerably change this effect.

Soluble interleukin-6 receptor (sIL-6R) makes IL-6R negative T cell line respond to IL-6; it inhibits TNF production

The receptor for interleukin-6 (IL-6) consists of two subunits: a ligand specific IL-6Ralpha and gp130 that is responsible for signal-transduction. A soluble form of the ligand specific chain was described that when complexed to IL-6 is capable of binding to the membrane-bound gp130 subunit and thus can elicit signal-transduction. This soluble receptor can act on cells that express only the gp130 but not the ligand-specific subunit of the IL-6R. This phenomenon, called trans-signaling, introduced a novel aspect of cytokine action. In this study we examined the response of Jurkat cells, that are known not to express IL-6Ralpha, to IL-6, the soluble IL-6 receptor (sIL-6R) and a covalent complex of IL-6 and sIL-6R termed Hyper-IL-6. We studied the expression of tumour necrosis factor (TNF) and interferon-gamma (IFN-gamma). The complex of IL-6+sIL-6R and Hyper-IL-6 inhibited significantly the production of TNF in a gp130-dependent manner, whereas no differences in IFN-gamma expression were found. IL-6 and sIL-6R alone were not effective. Because we did not detect major differences in the TNF mRNA levels upon treatments, we conclude that the inhibition of TNF production should occur at the post-transcriptional level. These results provide another example of trans-signaling and underline the physiological importance of sIL-6R, and in the case of Hyper-IL-6 its possible therapeutic application can also be considered.

Exon-intron organization of the human gp130 gene

The exon-intron organization and sequences of the exon-intron boundaries of the human gp130 transmembrane receptor gene have been determined using genomic DNAs as samples. The gp130 gene comprises 17 exons and 16 introns. The positions of the exon-intron boundaries show good correlation to the functional/homology regions of gp130. Exons 3-17 code for the gp130 protein, and each subdomain of the receptor is encoded by a set of exons. The coding potential of exons and the intron phasing of the human gp130 gene conform to the patterns observed previously for other cytokine receptor genes. This supports the notions that the gp130 gene evolved from the same ancestral gene that gave rise to other members of the cytokine receptor family.

Biosynthesis of interleukin-6, an autocrine growth factor for melanoma, is regulated by melanoma-derived histamine

Interleukin-6 is an autocrine growth factor in advanced stage melanoma and biosynthesis of IL-6 is increased by histamine in various cell lines. In our study we analysed the direct relation of histamine and IL-6 synthesis in human melanoma cell lines. All melanoma cells contained IL-6 mRNA, but only metastatic melanoma cells secreted the IL-6 protein. The H1 histamine receptor antagonist triprolidine decreased gene expression and biosynthesis of IL-6, while other histamine receptor antagonists had no effect. These data indicate that endogenous histamine has a definite role in the regulation of local IL-6, suggesting that histamine and IL-6 could be part of autocrine growth regulation of the tumor.

H1 histamine receptor antagonist inhibits constitutive growth of Jurkat T cells and antigen-specific proliferation of ovalbumin-specific murine T cells

Histamine is produced from histidine by histidine decarboxylase (HDC) in many cells including normal and malignant lymphocytes. We examined the expression of HDC and the effect of histamine receptor antagonists on the proliferation of a human T cell line, Jurkat and on antigen-driven proliferation of lymphocytes from ovalbumin-immunized mice. Our results demonstrate that HDC is inducible in Jurkat cells by anti-CD3. The H1 receptor antagonist triprolidine dose dependently inhibits proliferation of both Jurkat cells and ovalbumin-stimulated murine lymphocytes, while the H2 antagonist ranitidine was ineffective. Alpha-fluoro-methyl-histidine blocking HDC activity did not inhibit the T cell proliferation, suggesting an existing pool of histamine in T cells.

Analysis of the genetic variability of the 1st (CCC/ACC, P52T) and the 10th exons (bp 1012-1704) of the TSH receptor gene in Graves' disease

We determined the genetic variability of the 1st (CCC/ACC, P52T polymorphic variant) and 10th exons (bp 1012-1704) of the TSH receptor (TSHR) gene in Graves' disease. A total of 101 Graves' patients and 163 control subjects were screened. The A253 mutant allele was carried by nine patients with Graves' disease (8.91%) and 13 control subjects (7.98%) in heterozygous genotype. No significant difference in the frequency of the mutant allele was found between Graves' patients and control subjects. These results provide evidence that the A253 polymorphism has no genetic relevance in Graves' disease. Moreover, the DNA nucleotide sequence of 693 bp of the 10th exon (bp 1012-1704) of the TSHR gene was determined in 15 Graves' patients. Six patients were homozygous for the wild-type allele and nine were heterozygous for the mutant allele at the 253rd nucleotide of the first exon. No polymorphism was found in the DNA sequences obtained from leukocytes of Graves' patients, similarly to the sequences obtained from the nine control subjects. None of the nine patients carrying the A253 polymorphism in the 1st exon of the TSHR had polymorphism in the examined part of the 10th exon, including two additional patients whose thyroid tissue was directly analysed. In all likelihood, the polymorphisms of the examined regions of either the 1st or the 10th exon of the THSR gene do not contribute to the genetic susceptibility to Graves' disease.

Angiotensin II type 1 receptor gene polymorphism and mitral valve prolapse syndrome

BACKGROUND

Mitral valve prolapse syndrome (MVPS), a term applied to patients who have a variety of symptoms, has been associated with autonomic or neuroendocrine dysfunction. Recent evidence suggests that effects of angiotensin II mediated by the angiotensin II type 1 (AT(1)) receptor are involved in modulation of cardiovascular autonomic control in human beings. Association of a genetic polymorphism (A-C(1166)) of the AT(1) gene with abnormal vasomotion and low blood pressure related to autonomic control has been reported recently. Because the role of this genetic variant in MVPS has not been studied, we performed a case-control study of the A-C(1166) variant in a group of 76 white subjects with MVPS.

METHODS AND RESULTS

All patients were genotyped by use of a mismatch polymerase chain reaction/Afl II restriction fragment length polymorphism analysis. Frequency of the C(1166) allele was 0.4 in patients with MVPS and 0.26 in control patients. The difference in genotype (chi square = 6.5; P <.05) and allele (chi square = 5.9; P =.02) frequencies between the groups was significant. The odds ratio in favor of carrying the C allele was 4 times greater for patients with MVP than for control patients (95% confidence interval 1.4 to 12.1).

CONCLUSIONS

The current results indicate that the A-C(1166) polymorphism of the angiotensin II type 1 receptor gene is associated with MVPS in the white population.

Keratin 9 mutations in the coil 1A region in epidermolytic palmoplantar keratoderma

The palmoplantar keratodermas (PPK) are a heterogeneous group of conditions, most frequently inherited in autosomal dominant fashion. A few are well-documented autosomal recessive disorders; other are acquired in association with certain metabolic disorders and malignancies. Recently different point mutations of the keratin 9 (K9) gene have been identified in unrelated families with epidermolytic palmoplantar keratoderma (EPPK). We investigated two unrelated Hungarian families with EPPK. In one, a mutation consisting of a G-->A transversion at nucleotide position 551, which changes codon arginine to glutamine at codon 162 (R162Q), was found. In the other, we observed a novel mutation at nucleotide position 571, which changes codon 169 lysine (AAG) into the amber stop codon (TAG) (K169X). Each found mutation is present in the highly conserved coil 1A region of the rod domain. In the case of a stop codon type of mutation, it is questionable whether it really results in a clinical phenotype, but segregation analysis revealed cosegregation of the PPK phenotype with the mutant allele.

Histamine and histamine-receptor antagonists modify gene expression and biosynthesis of interferon gamma in peripheral human blood mononuclear cells and in CD19-depleted cell subsets

The effect of histamine and histamine antagonists was examined on gene expression and biosynthesis of bacterial endotoxin (LPS) induced interferon gamma (IFNgamma) both in human peripheral mononuclear cells (PMBC) and in T-cell enriched fractions. We found, that histamine inhibited the LPS induced transcription of IFNgamma gene and biosynthesis of IFNgamma protein in PMBC and also in CD19-depleted cell populations. The inhibitory effect of histamine could be reversed by the H2 histamine receptor (HR2) antagonists cimetidine and ranitidine both in PMBC and in CD19-depleted cells, but not with triprolidine, an H1 receptor antagonist, suggesting that the inhibition of IFNgamma production is mediated through H2 receptors in these cell populations. In contrast to the inhibitory effect of histamine, cimetidine alone (in the absence of exogenous histamine) strongly stimulated both the IFNgamma mRNA and protein production, whereas this effect was hardly seen by and other H2 receptor blocker, ranitidine. This superinduction of IFNgamma gene by cimetidine disappeared if the CD19+ cells are removed from PMBC. These results suggest, that inhibition of IFNgamma gene expression by histamine is a direct effect of histamine on H2 receptor of T lymphocytes; however, the superinduction of IFNgamma by cimetidine requires the presence of other (probably primarily B) cell subsets.

Elevated hepatic glucocorticoid receptor expression during liver regeneration in rats

In rats within the first week of partial hepatectomy reconstruction of the normal histological structure of the liver already starts. To approach the possible role of endogenous glucocorticoids in the process of regeneration we measured the changes in the expression of steroid glucocorticoid receptor gene after various regeneration intervals. After partial hepatectomy, between 0.5 168 hours from the surgery, the gene expression (mRNA) of glucocorticoid receptor was determined by reverse transcription followed by PCR and normalized to that of glycerolphoshate dehydrogenase. Two peaks of glucocorticoid receptor mRNA were detected first, between 3 and 6 hours (first peak) and a second between 24 and 36 hours. Immunoreactive glucocorticoid receptor was detected by immunohistochemistry using monoclonal anti-glucocorticoid receptor. Three days after the surgery immunohistochemical studies showed substantially more immunoreactive GcR protein in the regenerated liver than in the controls. These semiquantitative data provide evidence suggesting elevation of glucocorticoid receptor expression during regeneration of liver at mRNA and protein levels.

Chemokine receptor CCR2 and CCR5 polymorphisms in children with insulin-dependent diabetes mellitus

Studies have shown the important roles of several regulatory and proinflammatory cytokines in insulin-dependent diabetes mellitus (IDDM). CC-chemokine receptors CCR2 and CCR5 bind chemokines that are involved in the trafficking of leukocytes in both basal and inflammatory states. A common 32-bp deletion mutation in the CCR5 gene (CCR5delta32) and a G-to-A nucleotide substitution in the CCR2 at position 190 (CCR2-64I) have recently been described. In the present study, we have determined the frequency of the CCR5delta32 and CCR2-64I alleles in children with IDDM [n = 115; age 1-14 (9.3+/-4.3) y] and in nondiabetic subjects [n = 280; age 1-14 (8.5+/-4.5) y]. The CCR5delta32 allele frequencies were 0.117 in children with IDDM and 0.111 in nondiabetic subjects, indicating that the deletion allele has no association with IDDM. The CCR2-64I allele frequency in children with IDDM was 0.226, which differed significantly from the allele frequency in controls (0.114, p = 0.001). The role of this mutation in IDDM cannot be explained yet, but, because CCR2 mediates the chemotaxis of CD4+ and CD8+ T cells to areas of inflammation and because these cells play important roles in insulitis, a mutation in the CCR2 gene may contribute to the susceptibility to the disease. Alternatively, the 64I allele could be a marker of a linked mutation through linkage disequilibrium. According to these results, the CCR2 gene may be a new candidate for the susceptibility locus of IDDM. However, because no IDDM locus has been identified near 3p21 until now, further investigations are needed to confirm this statement.

Generation of 'truncated' interleukin-6 receptor (IL-6R) mRNA by alternative splicing; a possible source of soluble IL-6R

Receptors for interleukin-6 (IL-6) occur in body fluids in soluble form, as well. This is an approx. 50 kDa protein with the ability to bind IL-6. The soluble IL-6 receptor (sIL-6R)/IL-6 complex can attach to membrane anchored gp130, a molecule associated with the signal transduction induced by IL-6 and by other related cytokines. Earlier we described the appearance of sIL-6R in various body fluids of autoimmune patients. In this study using reverse transcriptase polymerase chain reaction (RT-PCR) we isolated and characterised a truncated form of amplified cDNA reverse-transcribed from IL-6 receptor mRNA both from human hepatoma cell line HepG2 and mononuclear cells from inflammatory bowel disease (IBD) patients. Using digestion by Pvu II restriction endonuclease and direct nucleotide sequencing we conclude that alternative splicing is likely involved in generation of sIL-6R. Our further experiments suggest that IL-6 and recombinant sIL-6R themselves do not influence the alternative splicing of IL-6 receptor gene.

The histidine decarboxylase (HDC) gene of Tetrahymena pyriformis is similar to the mammalian one. A study of HDC expression

RNA was isolated from Tetrahymena pyriformis GL and using human histidine decarboxylase (HDC) gene primers, the RT-PCR product was sequenced. A fraction containing 207 base pairs was compared to the published sequences of prokaryotic and mammalian (rat, mouse and human) HDC cDNA (exons). The HDC-cDNA fraction of Tetrahymena was similar to the mammalian cDNA-s and it was completely different from the prokaryotic HDC-gene. The results indicate the presence of a mammalian-like HDC-gene already in a unicellular eukaryote organism and demonstrates also that the divergence of the prokaryotic-eukaryotic common gene took place already at this low evolutionary level.

Increased interleukin-6 levels, interleukin-6 receptor and gp130 expression in peripheral lymphocytes of patients with inflammatory bowel disease

Interleukin-6 is one of the most well-characterized cytokines with pleiotropic properties. Besides its B-lymphocyte activation role in hematopoiesis, interleukin-6 plays a central role in regulation of systemic inflammation. Interleukin-6 binds to receptors on target cells (such as hepatocytes and lymphocytes), consisting of an 80 kDa binding chain and gp130, a polypeptide responsible for signal transduction. In addition to the detection of elevated amounts of interleukin-6 in the blood, gene expression (mRNA) of subunits of the interleukin-6 receptor complex have also been studied by examining the reverse transcriptase polymerase chain reaction on peripheral lymphocytes from patients with characteristic radiological symptoms suffering from Crohn's disease. Our data show significantly elevated gene expression both of the 80 kDa interleukin-6 binding chain and gp130. These results suggest that enhancement of the expression of the constituents of interleukin-6 and the interleukin-6 receptor system plays a relevant role in systemic inflammation in inflammatory bowel disease.

Growth hormone receptor gene expression on human lymphocytic and monocytic cell lines

The potential effect of growth hormone (GH) in tumorigenesis, particularly in acute leukemia is controversial. Human growth hormone has the ability to influence certain immune functions; the majority of immune cells express growth hormone receptor (GHR) on plasma membranes. We determined GHR gene expression on different human lymphocyte (JURKAT, CESS) and monocyte (U937, THP1) cell lines by reverse transcriptase polymerase chain reaction analysis of GHR mRNA after stimulating the cells with phytohaemagglutinin or phorbolester, human growth hormone and with a combination of these. The receptor gene expression showed differences; in the U937 and CESS cell lines only the stimulants were able to induce GHR mRNA expression; in the case of JURKAT cells even the hormone alone had the ability to express its own receptor gene. Both the increased TNF-alpha production of U937 (but not that of THP1 cells), and the decreased proliferation of JURKAT cells in response to GH stimuli also prove the presence of biologically active GHR on the cell surface. Our data suggest asymmetric interaction between GH or phorbolester-induced signal pathways in U937 cells sharply depending on the temporal sequence of treatments. THP1 monocytes showed no gene expression in response to any of the stimulants. The phenomenon that certain human lymphoid and monocytoid cell lines at different levels of cell differentiation are able to express the GH receptor gene could have importance in the rhGH therapy.

[The in vitro effect of recombinant human growth hormone on lymphocyte and granulocyte function in healthy and uremic children]

The aim of the study was to establish the effect of GH on immune functions in 22 healthy and in 11 uremic children, in vitro. Oxydative burst of granulocyte in the presence of GH measured by chemiluminescence and lymphoblast proliferation to GH and lectin stimuli were studied. Gene expression of GH receptor was analyzed with reverse transcriptase polymerase chain reaction (RT-PCR) method. The metabolic burst of granulocytes individually differed, specially in the chronic renal failure (CRF) group (60%) showed rather dose and time-dependent increase, the GH had only a priming effect. In 59% of the healthy children the GH stimulated the lympho-proliferative response itself or interaction with the lectin (ANOVA-test) and increased the spontaneous lymphoproliferation in 45% of the uremic patients. The GH receptor mRNA expression differed in the childrens lymphocytes, showing no correlation with the effect of GH on lymphoproliferation. The GH has a cytokine-like role in the regulation of the human immune system, and the GH treatment in uremic children is rather stimulating on immune functions.

In vitro effect of human recombinant growth hormone on lymphocyte and granulocyte function of healthy and uremic children

The recombinant human growth hormone (rhGH), currently used in supraphysiological doses to promote growth acceleration in chronic renal failure children (CRF), also has the ability to influence their impaired immune functions. The effect of human growth hormone on the lymphoproliferative response in vitro was analyzed in the peripheral blood lymphocytes of 25 healthy and 11 uremic children. In 72% of the uremic cases and in 60% of the healthy individual children the hormone increased the lymphoproliferation alone, and/or when used in combination with phytohaemagglutinine. The range of the effective hormone concentrations differed individually. Using semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) a great variation in the gene expression of growth hormone- (GH)-receptor in peripheral lymphocytes was detected. The respiratory burst activity of peripheral polymorphonuclear leukocytes (PMN) in vitro, in response to GH alone and when combined with suboptimal dose of phorbolester (PMA), was assessed by measuring luminol enhanced chemiluminescence in ten uremic and 18 healthy children. In six out of the ten of the CRF patients and in eight out of 18 of the healthy children the GH enhanced the oxidative burst activity of granulocytes provoked by a suboptimal dose of PMA. However, the effective doses (10, 50 and 300 ng/ml) and incubation times (0, 45 and 90 min) showed individual variations. Our data suggest that rhGH treatment in uremic children could be advantageous considering this population's enhanced susceptibility to bacterial, viral and fungal infections.

Soluble interleukin 6 (IL-6) receptor influences the expression of the protooncogene junB and the production of fibrinogen in the HepG2 human hepatoma cell line and primary rat hepatocytes

Interleukin 6 (IL-6) belongs to a family of cytokines using receptors sharing a common signal-transducing chain, gp130 and containing a specific ligand-binding chain (IL-6R alpha). It was shown that both the membrane-bound and the soluble form (sIL-6R) of this ligand specific receptor chain occurs naturally. The soluble form of IL-6 receptor was found to be able to associate with the membrane-bound gp130 and to generate active IL-6 receptor complex capable of inducing signal transduction. This study on a human hepatoma cell line and primary rat hepatocytes examined how the effectiveness of IL-6 is modified by the presence of soluble IL-6 receptor and whether the sIL-6R in the absence of IL-6 acts on hepatocytes. The authors studied the gene expression of junB, a member of the Jun family of transcription factors, and the production of fibrinogen in response to IL-6 and sIL-6R. The data show that in hepatic cells, endogeneously expressing IL-6R, the IL-6 induced junB and fibrinogen expression is inhibited by the presence of sIL-6R. In addition we found that sIL-6R alone (in the absence of IL-6) induced junB mRNA expression, but had no effect on fibrinogen production.

Histidine decarboxylase in peripheral lymphocytes of healthy individuals and chronic lymphoid leukemia patients

Histidine decarboxylase (HDC), the only enzyme capable of synthetizing histamine, has been found in many proliferating cells and tissues suggesting a role of histamine in cellular proliferation. In this study expression of HDC and the significance of histamine in the proliferation of peripheral lymphocytes of five healthy persons and six patients with chronic lymphoid leukemia (CLL) was examined. Expression of HDC mRNA and the protein was proved by reverse transcriptase polymerase chain reaction and by immunoblot, respectively. The role of histamine was studied in proliferation assays in the presence of irreversible inhibitor of the HDC (alpha-fluoromethylhistidine--aFMH) and also by competing for the intracellular binding sites of histamine using N,N-diethyl-2, 4-phenylmethyl-phenoxy-ethanamine-HCl (DPPE). By inhibiting the HDC enzyme activity by FMH and blocking the intracellular action of histamine by DPPE, a significant decrease in cell proliferation was observed in mitogen stimulated lymphocytes of healthy donors. In CLL patients the proliferation of leukemic lymphocytes was significantly inhibited by blocking the binding of histamine to intracellular binding sites by DPPE but not by FMH inhibiting only the de novo histamine formation. The observations suggest that HDC has functional relevance in lymphocytes, since mitogen induced lymphocyte proliferation of healthy donors is mainly enhanced by de novo synthesis and subsequent action of intracellular histamine. Alternatively, in constitutively proliferating chronic lymphoid leukemia cells we suggest that the preformed pool but not the de novo synthesized intracellular histamine interferes with cellular proliferation.