Identification of new regulatory sequences far upstream of the mouse monocyte chemoattractant protein-1 gene

We systematically searched for sequences influencing the expression of the mouse monocyte chemoattractant protein-1 (MCP-1) gene (Scya2) by mapping DNase I hypersensitive sites (HS) in the chromatin of mesangial cells in a 40-kb interval around the gene. We found nine HS located between -24 kb and +12.7 kb. Three HS coincided with previously known regulatory sequences (HS-2.4, HS-1.0, and HS-0.2). We tested two of the previously unknown HS located far upstream of Scya2 (HS-19.4 and HS-16.3) in transfection experiments using luciferase reporter constructs and mouse mesangial cells as recipients. In transient transfections, both HS had a moderate effect on basal promoter activity as well as promoter activity stimulated by tumor necrosis factor-alpha. In stable transfection experiments, we found much higher activity. A DNA fragment containing HS-19.4 and HS-16.3 caused a considerable increase in the number of stably integrated luciferase copies. We determined the nucleotide sequence of the 5' flanking region to -28.6 kb. Computer-assisted sequence analysis did not yield evidence of an additional gene. These HS are located within the 5' flanking region of a gene cluster consisting of Scya2 (MCP-1), Scya7 (MCP-3), Scya11 (eotaxin), Scya12 (MCP-5), and Scya8 (MCP-2). This report represents the first comprehensive chromatin analysis of the mouse MCP-1 locus leading to the identification of a complex regulatory region located far upstream of Scya2.

Thymic epithelial tumors can develop along two different pathogenetic pathways

To investigate genetic abnormalities associated with the development of thymic epithelial tumors, we performed microsatellite analysis of 26 thymomas belonging to three different World Health Organization types (A, B3, and C) using 48 repeats. The most frequent aberration seen was loss of heterozygosity (LOH) in the region 6q23.3-25.3 detected in 11 tumors (45.8% of informative cases). Further consistent LOHs were detected in regions 3p22-24.2, 3p14.2 (FHIT gene locus), 5q21 (APC), 6p21, 6q21-22.1, 7p21-22, 8q11.21-23, 13q14 (RB), and 17p13.1 (p53). Microsatellite instability was extremely rare, occurring in one type B3 thymoma only, although, at 12.5% of the analyzed loci. Comparing the allelotypes of the analyzed thymomas, we were able to identify two pathogenetic pathways these tumors develop along, characterized by the 6q23.3-25.3 and 5q21 LOHs, respectively. The APC aberration on 5q21 showed significant associations with LOH in the 3p22-24.2, 13q14, and 17p13.1 regions. Interestingly, type A thymomas presented with consistent LOH in the region 6q23.3-25.5 only, they did not reveal any aberrations in the APC, RB, and p53 gene loci or regions 3p22-24.2 and 8q11.21-23. The absence of these aberrations might be the reason for the well-known benign behavior of type A thymomas as compared to types B3 and C tumors.

Inhibition of granulocyte-macrophage colony-stimulating factor receptor function by a splice variant of the common beta-receptor subunit

The receptors for human granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and IL-5 are composed of a ligand-specific alpha-chain (eg, alpha-GM-CSF receptor [alpha-GMR]) and a common beta-subunit (beta-GMR). Ligand binding is believed to induce assembly or conformational changes in preformed complexes containing more than one alpha- and beta-subunit in the activated receptor complex. To analyze the function of a splice variant of beta-GMR with a truncation in the intracellular domain (beta-GMR(IT)), BaF-3 cells expressing human alpha-GMR plus beta-GMR were transfected with beta-GMR(IT). In these cells, coexpression of beta-GMR(IT) inhibits GM-CSF-mediated survival and proliferation in a GM-CSF concentration-dependent manner. To analyze the effect of cytoplasmic assembly of truncated and full-length intracellular beta-GMR sequences, beta-GMR and beta-GMR(IT) were coexpressed with different chimeric alpha/beta-GMR constructs. Whereas both beta-GMR and beta-GMR(IT) generate high-affinity GMR complexes in the presence of alpha/beta-GMR, beta-GMR(IT) inhibits while beta-GMR supports proliferation and cell survival mediated by alpha/beta-GMR. Correspondingly, beta-GMR, but not beta-GMR(IT), generates functional GMR complexes when coexpressed with a defective alpha/beta-GMR construct. These data indicate that beta-GMR(IT) can inhibit survival and mitogenic signaling of the wild-type GMR and demonstrate that recruitment of alternatively spliced receptor subunits may regulate the function of heteromeric cytokine receptors.

Effects of angiotensin II and the AT(1) receptor antagonist losartan on the renal excretion of urodilatin

BACKGROUND

The precise mechanisms regulating the natriuretic peptide urodilatin (ANP-95-126) remain to be defined. Renal excretion of urodilatin (U(URO)V) has been shown to be modified by variations in plasma sodium and renal perfusion pressure. This suggests a relationship between urodilatin and the renin-angiotensin system.

METHODS

We investigated the effects of angiotensin II (AII, 0.1 nmol/l) and the AT(1) receptor antagonist losartan (LS, 1 micromol/l) on U(URO)V and renal function in isolated rat kidneys perfused for 180 min in a closed circuit system. A further series employing a vasoconstricting concentration of endothelin-1 (ET-1, 0.01 nmol/l) was performed to explore the effects of vasoconstriction and glomerular filtration rate (GFR) on U(URO)V.

RESULTS

Urine flow (UV) and urinary sodium excretion (U(Na)V) decreased and renal vascular resistance (RVR) increased after treatment with AII (n = 5) in comparison with a control group (n = 6; p < 0.05). Treatment with LS (n = 5) and AII+LS (n = 5) had no significant effect on these parameters. GFR decreased after AII (p < 0.05) and was not significantly altered by other interventions. U(URO)V decreased after AII (p < 0.05) and was comparable to the control group after LS and AII+LS. ET-1 (n = 5) induced a significant increase in RVR and decreased UV and U(Na)V (p < 0.05). Point-to-point analysis revealed that the ET-1-induced vasoconstriction and the subsequent decrease in GFR had no effect on U(URO)V.

CONCLUSIONS

This suggests that vasoconstrictory concentrations of AII decrease U(URO)V in the isolated perfused rat kidney. The lack of effect of ET-1 on U(URO)V suggests that the AII-induced alterations in urodilatin excretion cannot be explained by vasoconstriction per se.

Relationship between peripheral intravenous catheter Dwell time and the development of phlebitis and infiltration

The purpose of this study was to evaluate whether lengthening the dwell time of peripheral i.v. catheters from 72 hours to 144 hours resulted in increased rates of phlebitis and/or infiltration. The study was conducted in medical/surgical units at a 110-bed teaching hospital with an i.v. team. Kaplan-Meier estimates of the success and failure and conditional failure probabilities were calculated for phlebitis and infiltration scores. Log rank tests were used to test for an association between the covariates and the time until failure. Drug irritation was the most significant predictor of phlebitis and infiltration rates in this study. The total difference in the estimated failure rates for the catheter lasting 6 days versus a new catheter inserted for another 3 days is 1.3%. Because the conditional failure probability estimates for days 4, 5, and 6 are slightly higher than for days 1, 2, and 3, consideration may be given to extending the dwell time of a peripheral i.v. catheter beyond 72 hours under certain circumstances.

Phenotype of five patients with Greig syndrome and microdeletion of 7p13

Here we describe five patients with Greig cephalopolysyndactyly syndrome (GCPS), including one pair of monozygotic twin boys with a de novo microdeletion involving the chromosomal band 7p13, where various clinical manifestations, in addition to GCPS, were recognized. Besides the twin pair, all patients are unrelated. Since there is a considerable lack of well-defined clinical delineation of the few patients with microdeletions involving 7p13 with GCPS described so far, we focus on the symptoms that are not typically related to GCPS, such as moderate psychomotor retardation, seizures, muscle fiber anomalies, cardiac anomalies, hyperglycemia, and hirsutism. Our observations suggest that in all cases of atypical GCPS, the presence of a cytogenetically detectable microdeletion or a submicroscopic deletion of 7p13 should be suspected.

Fibroblast-mediated delivery of growth factor complementary DNA into mouse joints induces chondrogenesis but avoids the disadvantages of direct viral gene transfer

OBJECTIVE

To assess the advantages and disadvantages of a direct adenoviral and a cell-mediated approach to the induction of cartilage formation in joints by transfer of growth factor genes.

METHODS

Adenoviral vectors carrying insulin-like growth factor 1 (IGF-1) or bone morphogenetic protein 2 (BMP-2) complementary DNA were constructed and applied to primary human and murine chondrocytes or fibroblasts. Transgene expression was quantified by enzyme-linked immunosorbent assay. Direct injection of these vectors or AdLacZ, a reporter gene vector, into mouse knee joints was compared with the transplantation of syngeneic fibroblasts (infected ex vivo with the same vectors) with respect to virus spread, immune response, and cartilage formation by use of histologic, immunohistochemical, and molecular analyses.

RESULTS

AdIGF-1 and AdBMP-2 efficiently infected all cell types tested. Human cells secreted biologically relevant levels of protein over a period of at least 28 days. Direct transfer of AdLacZ into mouse knee joints resulted in positively stained synovial tissues, whereas AdLacZ-infected fibroblasts settled on the surface of the synovial membranes. Inadvertent spread of vector DNA into the liver, lung, and spleen was identified by nested polymerase chain reaction in all mice that had received the vector directly; this rarely occurred following fibroblast-mediated gene transfer. Direct injection of AdBMP-2 induced the synthesis of new cartilage in periarticular mesenchyme, accompanied by extensive osteophyte formation. When AdBMP-2 was administered by injecting ex vivo-infected fibroblasts, cartilage formation was observed only in regions near the injected cells. AdIGF-1 treatment did not lead to morphologic changes. Importantly, fibroblast-mediated gene transfer avoided the strong immune response to adenovirus that was elicited following direct application of the vector.

CONCLUSION

Our results indicate that cell-mediated gene transfer provides sufficient BMP-2 levels in the joint to induce cartilage formation while avoiding inadvertent vector spread and immune reactions.

[Medical exercise therapy--indications, tips on individualized prescription]

Medical training therapy (MTT) belongs to the active methods which can be used by physiotherapists under medical prescription. This dynamic method was originally developed by O. Holten in Norway but it has become extremely popular in patients and did also convince a large number of therapists; as a consequence of its success, its prescription increased progressively and actually replaced larger parts of the passive methods used before. The aims of MTT is to work in a pain free environment and increase both muscle resistance, strength and joint mobility as well. The technique does not have any absolute contraindication, but it has to be individually adapted to each single patient. A true advantage of MTT is certainly that the active training sessions can be done in small well controlled groups of patients. As it does also apply for other types of currently used physical therapies, there are only restricted evidence-based proofs of efficacy and therefore scientifically sound studies are still needed in this field.

Chronic myeloid leukemia with a rare variant Philadelphia translocation: t(9;10;22)(q34;q22;q11)

We report a 59-year-old, male, chronic myeloid leukemia patient with a rare variant Philadelphia (Ph) translocation t(9;10;22)(q34;q22;q11). Fluorescence in situ hybridization with whole chromosome paints was used to confirm the cytogenetic findings. With a BCR/ABL-specific probe, the known rearrangement on the derivative chromosome 22 was found. The prognostic implications as well as the relevance of the additional breakpoint region 10q22 are discussed.

Candidate region for Gilles de la Tourette syndrome at 7q31

Gilles de la Tourette Syndrome (GTS) is a complex neuropsychiatric disorder characterized by motor and vocal tics. The cause of this syndrome is unknown, although based on family studies there is evidence of a strong genetic component. We report on a 13-year-old boy with GTS, minor physical anomalies, and a de novo partial duplication of chromosome 7q [dup(7)(q22.1-q31.1)]. The distal breakpoint in our patient is similar to the breakpoint of an apparently balanced familial translocation t(7;18) segregating with GTS. Together, these cases provide evidence that a gene located in the breakpoint region at 7q31 can be involved in the formation of GTS.

Aromatic quinolinecarboxamides as selective, orally active antibody production inhibitors for prevention of acute xenograft rejection

The prevention of xenograft rejection is substantially dependent on inhibiting antibodies (Ab) produced by B-cells independently of T-cell signals (TI-1). Due to their ubiquitous biochemical mechanisms of action, the immunosuppressants currently employed not only fail to discriminate between B- and T-cells but also have a narrow therapeutic window and, thus, their prolonged use in complex immunosuppressive regimens is problematic. By capitalizing on the target enzyme-bound (DHODH) structure 1b of one of these compounds, leflunomide, and modulating part of its multiple mechanisms of action to gain selectivity, the quinoline-8-carboxamide 3 was designed as a potentially weak enzyme inhibitor but effective immunosuppressant. Compound 3 fulfilled the mechanistic criteria set and had 10-fold B-cell over T-cell selectivity. Its pyridyl analogue 4 was found to be a highly potent and selective B-cell immunosuppressant with a 75-fold selectivity for B- over T-cells (as judged by the MLR data) and no general cytotoxicity at concentrations up to 160-fold higher than those required to inhibit B-cells. In the mouse, 4 effectively blocked TI-1 Ab production and suppressed Ab-mediated xenograft rejection in a xenotransplantation model under a once-daily dosing regimen, with efficacy down to 0.3 mg/kg/day po. These are the first data demonstrating the feasibility of the development of drugs specific for impeding Ab production.

Pbx4, a new Pbx family member on mouse chromosome 8, is expressed during spermatogenesis

Members of the Pbx family are involved in a diverse range of developmental processes including axial patterning and organogenesis. Pbx functions are in part mediated by the interaction of Pbx proteins with members of the Hox and Meis/Prep families. We have identified a fourth mammalian Pbx family member. Pbx4 in the mouse and PBX4 in humans are located on chromosome 8 and chromosome 19, respectively. Pbx4 expression is confined to the testis, especially to spermatocytes in the pachytene stage of the first meiotic prophase.

Histone acetylation and chromatin remodeling

Chromatin represents a repressive barrier to the process of transcription. This molecular obstacle is a highly dynamic structure, able to compact the DNA of the entire genome into the confines of a nucleus, and yet it allows access to the genetic information held within. The acetylation of histones has emerged as a regulatory mechanism capable of modulating the properties of chromatin and thus the competence of the DNA template for transcriptional activation. The role of acetylation in chromatin remodeling is therefore of paramount importance to our understanding of gene regulation in vivo.

Molecular cytogenetics and phenotype characterization of a de novo pure partial trisomy 10(q24.33-qter)

The molecular-cytogenetic characterization of a de novo pure partial trisomy 10(q24.33-qter) is described. This report provides information about the postnatal phenotype. The clinical findings observed in this case support the conclusion that the more severe disease related genes are located between 10q24.1 and q24.33.

Disruption of a novel gene (IMMP2L) by a breakpoint in 7q31 associated with Tourette syndrome

Gilles de la Tourette syndrome (GTS) is a complex neuropsychiatric disorder characterized by multiple motor and phonic tics. We identified a male patient with GTS and other anomalies. It was determined that he carried a de novo duplication of the long arm of chromosome 7 [46,XY,dup(7)(q22.1-q31.1)]. Further molecular analysis revealed that the duplication was inverted. The distal chromosomal breakpoint occurred between the two genetic markers D7S515 and D7S522, which define a region previously shown to be disrupted in a familiar case of GTS. Yeast and bacterial artificial chromosome clones spanning the breakpoints were identified by means of FISH analysis. To further characterize the distal breakpoint for a role in GTS, we performed Southern blot hybridization analysis and identified a 6.5-kb SacI junction fragment in the patient's genomic DNA. The DNA sequence of this fragment revealed two different breaks in 7q31 within a region of approximately 500 kb. IMMP2L, a novel gene coding for the apparent human homologue of the yeast mitochondrial inner membrane peptidase subunit 2, was found to be disrupted by both the breakpoint in the duplicated fragment and the insertion site in 7q31. The cDNA of the human IMMP2L gene was cloned, and analysis of the complete 1,522-bp transcript revealed that it encompassed six exons spanning 860 kb. The possible role of IMMP2L and several other candidate genes within the region of chromosomal rearrangement, including NRCAM, Leu-Rch Rep, and Reelin, is discussed. The 7q31 breakpoint interval has also been implicated in other neuropsychiatric diseases that demonstrate some clinical overlap with GTS, including autism and speech-language disorder.

Maternal methylation imprints on human chromosome 15 are established during or after fertilization

Prader-Willi syndrome (PWS) is a neurogenetic disorder that results from the lack of transcripts expressed from the paternal copy of the imprinted chromosomal region 15q11-q13 (refs. 1,2). In some patients, this is associated with a deletion of the SNURF-SNRPN exon 1 region inherited from the paternal grandmother and the presence of a maternal imprint on the paternal chromosome. Assuming that imprints are reset in the germ line, we and others have suggested that this region constitutes part of the 15q imprinting center (IC) and is important for the maternal to paternal imprint switch in the male germ line. Here we report that sperm DNA from two males with an IC deletion had a normal paternal methylation pattern along 15q11-q13. Similar findings were made in a mouse model. Our results indicate that the incorrect maternal methylation imprint in IC deletion patients is established de novo after fertilization. Moreover, we found that CpG-rich regions in SNURF-SNRPN and NDN, which in somatic tissues are methylated on the maternal allele, are hypomethylated in unfertilized human oocytes. Our results indicate that the normal maternal methylation imprints in 15q11-q13 also are established during or after fertilization.

Posttransplant diabetes mellitus in pediatric thoracic organ recipients receiving tacrolimus-based immunosuppression

BACKGROUND

Posttransplantation diabetes mellitus (PTDM) is a well-known complication of tacrolimus-based immunosuppression in both adult and pediatric solid organ recipients. The "natural history" of diabetes in the pediatric thoracic transplant population has not yet been described.

METHODS

We identified all pediatric thoracic transplant patients receiving tacrolimus-based immunosuppression who developed PTDM. Medical records were reviewed, with a particular focus on the clinical course of PTDM and its relationship to drug weaning.

RESULTS

Diabetes developed in 24 of 143 (17%) 30-day survivors of heart (12/96, 13%) and heart-lung/lung (12/ 47, 26%) transplantation. In 17 (71%) patients, the immunosuppressive regimen at the onset of PTDM also included maintenance corticosteroids. Seventeen patients demonstrated glucose intolerance before the onset of diabetes. Nine patients (38%) developed diabetes during pulsed corticosteroid therapy. Median time of onset after transplantation was 9.0 months. All patients required s.c. insulin for glucose control. The median follow-up from transplant was 49.9 months. There was a significant decrease in mean tacrolimus dosage (P<0.01), tacrolimus level (P<0.04), and steroid dosage (P<0.02) from onset of PTDM to most recent follow-up. Despite this significant reduction in immunosuppression, only 3/24 (13%) patients were successfully weaned off insulin.

CONCLUSIONS

Diabetes mellitus is a common complication in pediatric thoracic transplant patients receiving tacrolimus-based immunosuppression. Insulin dependence in our population rarely resolved, even after lowering tacrolimus and steroid doses. Discontinuation of steroids did not guarantee resolution of diabetes.

DNA condensation in two dimensions

We have found that divalent electrolyte counterions common in biological cells (Ca(2+), Mg(2+), and Mn(2+) ) can condense anionic DNA molecules confined to two-dimensional cationic surfaces. DNA-condensing agents in vivo include cationic histones and polyamines spermidine and spermine with sufficiently high valence (Z) 3 or larger. In vitro studies show that electrostatic forces between DNA chains in bulk aqueous solution containing divalent counterions remain purely repulsive, and DNA condensation requires counterion valence Z >/= 3. In striking contrast to bulk behavior, synchrotron x-ray diffraction and optical absorption experiments show that above a critical divalent counterion concentration the electrostatic forces between DNA chains adsorbed on surfaces of cationic membranes reverse from repulsive to attractive and lead to a chain collapse transition into a condensed phase of DNA tethered by divalent counterions. This demonstrates the importance of spatial dimensionality to intermolecular interactions where nonspecific counterion-induced electrostatic attractions between the like-charged polyelectrolytes overwhelm the electrostatic repulsions on a surface for Z = 2. This new phase, with a one-dimensional counterion liquid trapped between DNA chains at a density of 0.63 counterions per DNA bp, represents the most compact state of DNA on a surface in vitro and suggests applications in high-density storage of genetic information and organo-metallic materials processing.

Coexpression of alpha and beta subunits of prolyl 4-hydroxylase stabilizes the triple helix of recombinant human type X collagen

We have reported previously on the expression of recombinant human type X collagen (hrColX) in HEK 293 and HT 1080 cells by using the eukaryotic expression vector pCMVsis (in which CMV stands for cytomegalovirus). Several stably transfected clones secreted full-length triple-helical hrColX molecules in large amounts, but the secreted collagen was underhydroxylated, with a hydroxyproline-to-proline ratio of 0.25 and a melting temperature (T(m)) of 31 degrees C. By comparison, native chicken type X procollagen has a T(m) of 46 degrees C. To stabilize the triple helix of hrColX, an hrColX-expressing clone (A6/16) was co-transfected with both alpha and beta subunits of human prolyl 4-hydroxylase. Clones were selected that secreted proalpha1(X) collagen chains with an apparent molecular mass of 75 kDa and an increased hydroxyproline-to-proline ratio of close to 0.5. As a result of enhanced prolyl hydroxylation, the T(m) of the hrColX was increased to 41 degrees C as measured by CD analysis at various temperatures. The CD spectra indicated a minimum ellipticity at 198 nm and a peak at 225 nm at 20 degrees C, confirming the presence of a triple helix. The same T(m) of 41 degrees C was measured for the triple-helical core fragments of hrColX of 60-65 kDa that were retained after brief digestion with chymotrypsin/trypsin at increasing temperatures. This shows that the human cell line HEK-293 is suitable for the simultaneous expression of three genes and the stable production of substantial amounts of recombinant, fully hydroxylated type X collagen over several years.

Expectations and quality of life of cancer patients undergoing radiotherapy

Expectations, real or false, affect the way patients respond to their illnesses. We assessed therapy-related expectations in relation to global quality of life in 55 cancer patients before and after radiotherapy. Factor analysis indicated that therapy-related expectations come into three broad categories--pain/emotional control, healing and tumour/symptom control. 35 patients expected 'healing' even though curative treatment was intended in only 19 and all patients had been fully informed. The expectation of healing was associated with high quality of life, and the same was true of perception of healing after radiotherapy. In the group as a whole, quality of life was little altered by radiotherapy, but it became substantially worse in those patients who had expected healing but perceived that this had failed, even though physician-assessed Karnofsky status did not change. These findings indicate that the expectation of healing, in cancer patients, is a component of a good global quality of life, whereas more limited expectations (pain control, tumour control) relate to lower quality of life. Patients' expectations deserve further study as a novel approach to improving care.

Phenotype-genotype correlations in a CMT2B family with refined 3q13-q22 locus

OBJECTIVE

To perform genotype-phenotype correlation and genetic linkage analysis in a family with axonal Charcot-Marie-Tooth (CMT) syndrome and ulcero-mutilating features.

BACKGROUND

CMT2B is a rare disorder belonging to the group of axonal CMT syndromes that is clinically characterized by marked distal muscle weakness and wasting as well as a high frequency of foot ulcers, infections, and amputations. So far only two families with this disorder have been described in which molecular genetic studies have shown evidence of autosomal dominant inheritance with linkage to chromosome 3q13-q22.

METHODS

The authors report a large Austrian family presenting with the typical clinical features of CMT2B. Detailed clinical and electrophysiologic data were obtained in 15 at-risk individuals and DNA samples from 19 family members were collected for genetic linkage studies.

RESULTS

Eight family members were definitely affected upon clinical and electrophysiologic examination and the majority revealed pronounced distal muscle wasting and weakness as well as prominent sensory abnormalities, which were frequently complicated by infections and amputations. Electrophysiologic studies showed normal or slightly to moderately slowed motor nerve conduction velocities, markedly reduced compound motor action potential amplitudes with chronodispersion, and absent or reduced amplitudes of sensory nerve action potentials. The molecular genetic study demonstrates linkage to chromosome 3q13-q22. Haplotype analysis in affected individuals indicates that the CMT2B locus is located between the flanking markers D3S1589 and D3S1549, representing a region of 10 cM.

CONCLUSIONS

This family is the third CMT2B family reported so far and confirms the existence of the CMT2B locus on chromosome 3q13-q22, which is responsible for a clinically and electrophysiologically homogeneous disorder with prominent distal muscle weakness and wasting, and ulcero-mutilating features. Marked sensory disturbances and the high frequency of foot ulcers, infections, and amputations in our patients seem to be typical for CMT2B. Recombination events in affected individuals reduce the CMT2B candidate gene interval considerably from 25 to 10 cM.