Medicines postpartum in Sweden and coverage in Janusmed Breastfeeding.

PURPOSE: The purpose of this article is (1) to investigate which medicines are prescribed and dispensed to women the first 6 months postpartum, (2) to identify medicines dispensed postpartum but not recommended during breastfeeding, and (3) to find medicines commonly dispensed postpartum, but not currently included in Janusmed Breastfeeding. METHODS: In this register-based cohort study covering births between January 2017 and August 2019, the Swedish Medical Birth Register (MBR), the Prescribed Drug Register, and Janusmed Breastfeeding were linked to identify medicines dispensed to women during the first 6 months postpartum, and how they are covered and classified in Janusmed Breastfeeding. RESULTS: During the first 6 months postpartum, 66% of women purchased at least one prescription medicine from the pharmacy. The most common medicines were contraceptive agents, analgesics, antibiotics, and glucocorticoids. A third of the 30 most commonly dispensed medicines have no information available about the safety of use in breastfeeding. The most dispensed medicines, where the database advises against use in breastfeeding, included several antitussive agents, a local anaesthetic, and several gestagens. The most commonly dispensed medicines not covered by the Janusmed Breastfeeding were medicines for dry eyes, for assisted reproduction, and HIV. CONCLUSION: Prescribed medicines compatible with breastfeeding are more common during the first 6 months postpartum than medicines not compatible with breastfeeding, but medicines which lack evidence for safety in breastfeeding are still commonly used.

Diagnostics of primary immunodeficiency diseases: a sequencing capture approach.

Primary Immunodeficiencies (PID) are genetically inherited disorders characterized by defects of the immune system, leading to increased susceptibility to infection. Due to the variety of clinical symptoms and the complexity of current diagnostic procedures, accurate diagnosis of PID is often difficult in daily clinical practice. Thanks to the advent of "next generation" sequencing technologies and target enrichment methods, the development of multiplex diagnostic assays is now possible. In this study, we applied a selector-based target enrichment assay to detect disease-causing mutations in 179 known PID genes. The usefulness of this assay for molecular diagnosis of PID was investigated by sequencing DNA from 33 patients, 18 of which had at least one known causal mutation at the onset of the experiment. We were able to identify the disease causing mutations in 60% of the investigated patients, indicating that the majority of PID cases could be resolved using a targeted sequencing approach. Causal mutations identified in the unknown patient samples were located in STAT3, IGLL1, RNF168 and PGM3. Based on our results, we propose a stepwise approach for PID diagnostics, involving targeted resequencing, followed by whole transcriptome and/or whole genome sequencing if causative variants are not found in the targeted exons.

The prognostic value and therapeutic target role of stathmin-1 in urinary bladder cancer.

BACKGROUND: The oncoprotein-18/stathmin 1 (STMN1), involved in cell progression and migration, is associated with clinical outcome in breast cancer. Here we aim to investigate its clinical significance in urinary bladder cancer and its possibilities as a therapeutic target. METHODS: Immunohistochemical analyses of STMN1 protein expression were performed in three patient cohorts: cohort I (n=115 Ta, n=115 T1, n=112 T2-4 stages), cohort II, based on randomised controlled trials (n=239 T1-T4), and cohort III of primary tumour/matched metastasis (n=90 T1-T4). The effects of STMN1 on cell proliferation and migration were evaluated in the urinary bladder cancer cell line, T24, by inhibiting STMN1-cellular expression using siRNA. RESULTS: In cohort I, high STMN1 expression correlated to shorter disease-specific survival hazard ratio (HR)=2.04 (95% confidence interval (CI) 1.13-3.68; P=0.02), elevated p53- (P<0.001) and Ki67-protein levels (P<0.001). The survival result was validated in cohort II: HR=1.76 (95% CI 1.04-2.99; P=0.03). In the metastatic bladder cancer material, 70% of the patients were STMN1-positive in both the primary tumour and matched metastases. In vitro, the growth and migration of the T24 cells were significantly reduced (P<0.01, P<0.0001, respectively), when transfecting the cells with STMN1-siRNA. CONCLUSIONS: STMN1 protein expression has prognostic significance but is primarily a potential treatment target in urinary bladder cancer.

Hypomorphic homozygous mutations in phosphoglucomutase 3 (PGM3) impair immunity and increase serum IgE levels.

BACKGROUND: Recurrent bacterial and fungal infections, eczema, and increased serum IgE levels characterize patients with the hyper-IgE syndrome (HIES). Known genetic causes for HIES are mutations in signal transducer and activator of transcription 3 (STAT3) and dedicator of cytokinesis 8 (DOCK8), which are involved in signal transduction pathways. However, glycosylation defects have not been described in patients with HIES. One crucial enzyme in the glycosylation pathway is phosphoglucomutase 3 (PGM3), which catalyzes a key step in the synthesis of uridine diphosphate N-acetylglucosamine, which is required for the biosynthesis of N-glycans. OBJECTIVE: We sought to elucidate the genetic cause in patients with HIES who do not carry mutations in STAT3 or DOCK8. METHODS: After establishing a linkage interval by means of SNPchip genotyping and homozygosity mapping in 2 families with HIES from Tunisia, mutational analysis was performed with selector-based, high-throughput sequencing. Protein expression was analyzed by means of Western blotting, and glycosylation was profiled by using mass spectrometry. RESULTS: Mutational analysis of candidate genes in an 11.9-Mb linkage region on chromosome 6 shared by 2 multiplex families identified 2 homozygous mutations in PGM3 that segregated with disease status and followed recessive inheritance. The mutations predict amino acid changes in PGM3 (p.Glu340del and p.Leu83Ser). A third homozygous mutation (p.Asp502Tyr) and the p.Leu83Ser variant were identified in 2 other affected families, respectively. These hypomorphic mutations have an effect on the biosynthetic reactions involving uridine diphosphate N-acetylglucosamine. Glycomic analysis revealed an aberrant glycosylation pattern in leukocytes demonstrated by a reduced level of tri-antennary and tetra-antennary N-glycans. T-cell proliferation and differentiation were impaired in patients. Most patients had developmental delay, and many had psychomotor retardation. CONCLUSION: Impairment of PGM3 function leads to a novel primary (inborn) error of development and immunity because biallelic hypomorphic mutations are associated with impaired glycosylation and a hyper-IgE-like phenotype.

The Human Protein Atlas as a proteomic resource for biomarker discovery.

The analysis of tissue-specific expression at both the gene and protein levels is vital for understanding human biology and disease. Antibody-based proteomics provides a strategy for the systematic generation of antibodies against all human proteins to combine with protein profiling in tissues and cells using tissue microarrays, immunohistochemistry and immunofluorescence. The Human Protein Atlas project was launched in 2003 with the aim of creating a map of protein expression patterns in normal cells, tissues and cancer. At present, 11,200 unique proteins corresponding to over 50% of all human protein-encoding genes have been analysed. All protein expression data, including underlying high-resolution images, are published on the free and publically available Human Protein Atlas portal (http://www.proteinatlas.org). This database provides an important source of information for numerous biomedical research projects, including biomarker discovery efforts. Moreover, the global analysis of how our genome is expressed at the protein level has provided basic knowledge on the ubiquitous expression of a large proportion of our proteins and revealed the paucity of cell- and tissue-type-specific proteins.

Correlation between LRIG1 and LRIG2 expressions and expression of 11 tumor markers, with special reference to tumor suppressors, in CIN and normal cervical epithelium.

OBJECTIVE: Novel biological markers LRIG1 and LRIG2 have been associated with favorable as well as poor prognosis, respectively, in different cancer types, including cervical cancer. The aim of this study was to investigate possible interactions between these proteins and other tumor markers, and as diagnostic adjuncts in CIN. METHODS: Cervical biopsies from 171 women, with normal epithelium, and low-grade and high-grade CIN were stained for LRIG1 and LRIG2, and 11 additional tumor markers. The tumor markers were chosen to be relevant in cervical neoplasms. Staining was evaluated semiquantitatively. RESULTS: Expression of LRIG1 and LRIG2 was found to correlate with increasing CIN grade, as well as with expression of tumor suppressor FHIT, independent of histological grade. In addition, tumor promoter LRIG2 expression correlated negatively with expression of tumor suppressor retinoblastoma protein and positively with IL-10. The latter correlation did not however remain after adjustment for CIN grade. p53 and p16 expressions correlated positively with LRIG1 expression in univariate analyses, but significance did not hold after adjustment for CIN grade. CONCLUSION: LRIG1 and LRIG2 expressions were seen in precancerous cervical epithelium and found to increase with increasing grade. There was an association between expression of these glycoproteins and FHIT tumor suppressor protein, independently of histological grade.

Compensatory signals associated with the activation of human GC 5' splice sites.

GC 5' splice sites (5'ss) are present in ∼1% of human introns, but factors promoting their efficient selection are poorly understood. Here, we describe a case of X-linked agammaglobulinemia resulting from a GC 5'ss activated by a mutation in BTK intron 3. This GC 5'ss was intrinsically weak, yet it was selected in >90% primary transcripts in the presence of a strong and intact natural GT counterpart. We show that efficient selection of this GC 5'ss required a high density of GAA/CAA-containing splicing enhancers in the exonized segment and was promoted by SR proteins 9G8, Tra2ß and SC35. The GC 5'ss was efficiently inhibited by splice-switching oligonucleotides targeting either the GC 5'ss itself or the enhancer. Comprehensive analysis of natural GC-AG introns and previously reported pathogenic GC 5'ss showed that their efficient activation was facilitated by higher densities of splicing enhancers and lower densities of silencers than their GT 5'ss equivalents. Removal of the GC-AG introns was promoted to a minor extent by the splice-site strength of adjacent exons and inhibited by flanking Alu repeats, with the first downstream Alus located on average at a longer distance from the GC 5'ss than other transposable elements. These results provide new insights into the splicing code that governs selection of noncanonical splice sites.

Sox5 can suppress platelet-derived growth factor B-induced glioma development in Ink4a-deficient mice through induction of acute cellular senescence.

SOX5 is a member of the high-mobility group superfamily of architectural non-histone proteins involved in gene regulation and maintenance of chromatin structure in a wide variety of developmental processes. Sox5 was identified as a brain tumor locus in a retroviral insertional mutagenesis screen of platelet-derived growth factor B (PDGFB)-induced mouse gliomas. Here we have investigated the role of Sox5 in PDGFB-induced gliomagenesis in mice. We show that Sox5 can suppress PDGFB-induced glioma development predominantly upon Ink4a-loss. In human glioma cell lines and tissues, we found very low levels of SOX5 compared with normal brain. Overexpression of Sox5 in human glioma cells led to a reduction in clone formation and inhibition of proliferation. Combined expression of Sox5 and PDGFB in primary brain cell cultures caused decreased proliferation and an increased number of senescent cells in the Ink4a-/- cells only. Protein analyses showed a reduction in the amount and activation of Akt and increased levels of p27(Kip1) upon Sox5 expression that was dominant to PDGFB signaling and specific to Ink4a-/- cells. Upon inhibition of p27(Kip1), the effects of Sox5 on proliferation and senescence could be reversed. Our data suggest a novel pathway, where Sox5 may suppress the oncogenic effects of PDGFB signaling during glioma development by regulating p27(Kip1) in a p19(Arf)-dependent manner, leading to acute cellular senescence.

The subcellular Sox11 distribution pattern identifies subsets of mantle cell lymphoma: correlation to overall survival.

Gene expression analysis demonstrated high expression of the neuronal transcription factor SOX11 in mantle cell lymphoma (MCL). In contrast to follicular lymphoma, small lymphocytic lymphoma and reactive lymphoid tissue, most MCLs tested (48/53 patients) expressed sox11 protein in the nucleus. Therefore nuclear sox11 expression represents a new tumour marker for a subset of MCL. However, 5/53 MCL cases expressed sox11 only in the cytoplasm; these MCL patients had a shorter survival compared to MCL with nuclear sox11 expression. These results suggest sox11 expression as a new diagnostic marker in MCL that could be related to the clinical and biological behaviour of MCL.

Expression profiling of microdissected cell populations selected from basal cells in normal epidermis and basal cell carcinoma.

BACKGROUND: Basal cell carcinomas (BCCs) are prevalent tumours with uniform histology that develop without any known precursor lesion. Alterations in the sonic hedgehog-patched1 signalling pathway are accepted as necessary events for tumorigenesis, and mutations in the patched1 gene are frequently present in tumours. OBJECTIVES: To analyse transcript profiles in BCC. METHODS: We used laser-assisted microdissection to isolate and collect cell populations defined under the microscope. Peripheral cells from nests of BCC were selected to represent tumour cells, and normal keratinocytes from epidermis basal layer were used as control. Extracted RNA was amplified and hybridized on to a cDNA microarray. Results Our results show that BCC cells express a transcript signature that is significantly different from that of normal keratinocytes, and over 350 genes with various functions were identified as differentially expressed. The compiled data suggest an upregulation of the Wnt signalling pathway as a major event in BCC cells. Furthermore, tumour cells appear to have an increased sensitivity to oxygen radicals and dysregulated genes involved in antigen presentation. RESULTS: were validated at both the transcriptional level using real-time polymerase chain reaction and at the protein level using immunohistochemistry. CONCLUSIONS: We show that microdissection in combination with robust strategies for RNA extraction, amplification and cDNA microarray analysis allow for reliable transcript profiling and that antibody-based proteomics provides an advantageous strategy for the analysis of corresponding differentially expressed proteins. We found that expression patterns were significantly altered in BCC cells compared with basal keratinocytes and that the Wnt signalling pathway was upregulated in tumour cells.

Contiguous X-chromosome deletion syndrome encompassing the BTK, TIMM8A, TAF7L, and DRP2 genes.

X-linked agammaglobulinemia (XLA) is characterized by low levels of B-lymphocytes with early-onset, recurrent, microbial infections occasionally causing neurological symptoms. We observed an atypical clinical course of XLA, complicated since early childhood with neurological impairment, progressive sensorineural deafness, and dystonia in six boys of four unrelated families. The neurologic symptoms suggested the diagnosis of Mohr-Tranebjaerg syndrome, caused by mutations in the TIMM8A gene, previously known as DDP1, and located centromerically of BTK. Deafness dystonia peptide (DDP1) participates in neurological development and is a part of the mitochondrial protein import pathway. Mutation analysis of the BTK gene revealed gross deletions of different lengths in all patients, in one case extending approximately 196 kb, including the genes TIMM8A, TAF7L, and DRP2. The most prominent clinical findings of this contiguous deletion syndrome are the combination of immunodeficiency and sensorineural deafness, which were present in all affected boys. The severity of symptoms, however, did not correlate with the extent of the deletion.

Studies of the separation and characterisation of mixtures of starch and cellulose derivatives by use of chromatography and mass spectrometry.

In this work a method was developed for characterisation of commercially available polymers consisting of mixtures of substituted cellulose and starch. Selective hydrolysis with specific enzymes was used to achieve separation of the two polymers in the mixture. Enzymes hydrolysing (1-->4)-alpha-D and (1-->6)-alpha-D-glycosidic bonds were used for the starch part and enzymes hydrolysing (1-->4)-beta-D-glycosidic bonds for the cellulose part. The hydrolysed fraction was separated from the unhydrolysed fraction and characterised by use of size-exclusion chromatography (SEC), to confirm that enzyme hydrolysis of the different polymers had occurred. High-performance anion-exchange chromatography (HPAEC) was performed to determine the amount of unmodified glucose units (UGU) in the fractions. Electrospray ionisation mass spectrometry (ESIMS) was used for determination of the substituents. All products were converted to monomers by acid hydrolysis to simplify mass spectral identification of the substituents. The monomers were further subjected to acetylation with acetic acid anhydride to facilitate identification of the substituents. By combining the results from the different analytical techniques a picture of the samples was obtained.

PTCH codon 1315 polymorphism and risk for nonmelanoma skin cancer.

BACKGROUND: The PTCH tumour suppressor gene is involved in the development of nearly all basal cell carcinomas (BCCs) of the skin and a fraction of squamous cell carcinomas (SCCs). A nonconservative Pro/Leu nucleotide polymorphism within PTCH exon 23 at codon 1315 was recently reported to be potentially important for the development of breast epithelial cell cancers. Objectives Accordingly, the status of PTCH codon 1315 was analysed for a possible association with the development of nonmelanoma skin cancers (NMSCs) in a pilot study. Because skin cancer risk is affected by specific population-dependent phenotypes such as skin and hair colour, codon 1315 was also analysed for normal allele frequency variation in human populations having differing extents of eumelanin vs. phaeomelanin. METHODS: The single nucleotide polymorphism in codon 1315 of the human PTCH gene was analysed in genomic DNA from six different populations comprising 472 blood samples and from 170 patients in four different categories with NMSC. Polymerase chain reaction and pyrosequencing were used to determine the allele frequencies. Allelic loss was furthermore determined in tumours following microdissection. RESULTS: The Pro/Pro genotype frequency ranged from 30% to 65% between populations, with a significant trend for a reduced frequency of the Pro/Pro genotype in populations having lighter pigmentation (P = 0.020). Pro/Pro frequency showed an increasing trend with increasing tumour case severity (P = 0.027). In 260 samples from 180 Swedish patients with NMSC and a control group of 96 healthy ethnically matched volunteers, no statistically significant pairwise differences between groups were detected in the PTCH codon 1315 allelic distribution, neither was a difference seen for multiple or early onset cases of BCC in the Swedish population. In Swedish patients with single tumours, allelic loss (loss of heterozygosity) was observed in 20 of 30 (67%) patients with BCC and four of 22 (18%) patients with SCC, with no preference in the allele lost. In contrast, the Pro/Pro genotype was frequent in seven U.S. patients having multiple independent BCCs. One of these patients was heterozygous, enabling allelic loss studies. Of 20 independent tumours, 11 had lost an allele; 10 of the 11 had lost Leu, suggesting nonrandom loss that favoured retention of Pro (P = 0.0059). CONCLUSIONS: Our results indicate an association between the eumelanin-to-phaeomelanin shift and a shift from the Pro/Pro genotype to Leu-containing genotypes. Failure to lose Pro during the shift to phaeomelanin may be associated with an increased population risk for BCC and increased individual risk for multiple BCC. During development of a tumour, the effect of Pro may be magnified by loss of the Leu allele.

High level of cannabinoid receptor 1, absence of regulator of G protein signalling 13 and differential expression of Cyclin D1 in mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a moderately aggressive B-cell lymphoma that responds poorly to currently used therapeutic protocols. In order to identify tumour characteristics that improve the understanding of biology of MCL, analysis of oligonucleotide microarrays were used to define specific gene expression profiles. Biopsy samples of MCL cases were compared to reactive lymphoid tissue. Among genes differentially expressed in MCL were genes that are involved in the regulation of proliferation, cell signalling, adhesion and homing. Furthermore, some genes with previously unknown function, such as C11orf32, C2orf10, TBC1D9 and ABCA6 were found to be differentially expressed in MCL compared to reactive lymphoid tissue. Of special interest was the high expression of the cannabinoid receptor 1 (CB1) gene in all MCL cases analysed. These results were further confirmed at the cellular and protein level by immunocytochemical staining and immunoblotting of MCL cells. Furthermore, there was a reduced expression of a regulator of G protein signalling, RGS13 in all MCLs, with a complete absence in the majority of cases while present in control lymphoid tissue. These results were further confirmed by PCR. Sequencing of the RGS13 gene revealed changes suggesting polymorphisms, indicating that downregulation of the expression of RGS13 is not related to mutations, but may serve as a new specific marker for MCL. Moreover, comparison between individual cases of MCL, revealed that the CCND1 gene appears to be differently expressed in MCL cases with high vs low proliferative activity.

Mosaic pattern of maternal and paternal keratinocyte clones in normal human epidermis revealed by analysis of X-chromosome inactivation.

During early development of the female embryo, one X-chromosome is randomly inactivated in each cell. As a result of growth, migration, and differentiation, the adult female becomes a mosaic of cells with either the paternal or the maternal X-chromosome inactivated. It is not known what structure the X-chromosome inactivation pattern has in skin of normal individuals. We investigated normal skin from four healthy females, heterozygous for the HUMARA microsatellite on the X-chromosome. Following careful microdissection, DNA from adjacent epidermal samples consisting of approximately 35 basal keratinocytes was digested with the methylation-sensitive enzyme HpaII. The inactivated X-chromosome remained intact due to extensive methylation. The enzyme-digested DNA was amplified using polymerase chain reaction and fragments were analyzed for size. Through examination of adjacent samples and consecutive sections, we found normal human skin to be composed of a fine mosaic of tiles with either maternal or paternal X-chromosome inactivated. The sizes of these tiles were between 20 and 350 basal cells. The method described has the potential to resolve the clonal status in normal as well as pathologic conditions.

Analysis of intratumoral heterogeneity of chromosome 3p deletions and genetic evidence of polyclonal origin of cervical squamous carcinoma.

Investigation on intratumoral genetic heterogeneity provides an important insight into the roles of genetic alterations in human carcinogenesis and clues to clonal origin of tumors. Intratumoral heterogeneity of genetic changes of cervical cancer has not been described so far. In this study, we analyzed the intratumoral heterogeneity of chromosome 3p deletions and X-chromosome inactivation patterns in multiple microdissected samples from each individual cervical cancer, attempting to understand the roles of 3p deletions in development of cervical cancer and its clonal origin. Totally, 120 normal and lesional samples from 14 cases of fresh cervicalcancers were analyzed. Frequency and patterns of allelic losses of 3p were assessed by polymerase chain reaction (PCR) amplification of 12 microsatellite markers flanking the frequently deleted regions of 3p, followed by Genescan analysis in an ABI 377 DNA sequencer. Loss of heterozygosity was recorded as heterogeneous pattern (LOH present in parts of samples or LOH involving different alleles among different samples) and homogeneous pattern (LOH involving identical alleles in all samples from the tumor). Allelic loss affecting at least one marker was detected in 8 of 14 cases (57%). Allelic losses, both homogeneous and heterogeneous, were frequently detected at FHIT gene region (D3S1300, 40% and 60%; D3S4103, 27.3% and 54.6%), 3p21.3-21.2 (D3S1478, 27.3% and 45.5%), and 3p24.2-22 (D3S1283, 30% and 50%). Seven of eight LOH-positive tumors exhibited homogeneous allelic loss involving at least one of these three 3p loci. Allelic losses were present in the CIN lesions synchronous with invasive lesions positive for LOH. Our findings suggest essential roles of genes on these 3p loci, particularly the FHIT gene in participating in clonal selection and early development of cervical cancer. Most interestingly, with the combination of LOH analysis and X-chromosome inactivation analysis, we provided the first clear genetic evidence of polyclonal origin of cervical invasive cancer in two of eight cases. This finding strongly suggests the importance of field defect (possible human papilloma virus) in cervical carcinogenesis.

Cryopreservation of viable human glioblastoma xenografts.

Human tumour xenografts maintained in nude mice are a valuable research tool. The passaging and maintenance of human tumour xenografts in immune-deficient animals are expensive and labour-intensive. This study presents a protocol that permits long-term cryopreservation of viable glioblastoma xenograft tissue pieces in liquid nitrogen. Twenty different human glioblastoma xenografts that have been successfully transplanted and repeatedly passaged in nude mice were cryopreserved to validate the method. Different passages were cryopreserved for up to 40 months. On retransplantation of the tumours, all cases except one grew successfully. In order to ensure that the individual tumours did grow (not induced mouse tumours) restriction fragment length polymorphism analysis with variable number of tandem repeats (VNTR) probes was carried out. The method permits the long-term storage of viable, retransplantable glioblastoma xenografts. It minimizes animal use for the maintenance of xenografts and permits cryo-back-up of valuable tumours, thus markedly reducing the cost and increasing the accessibility of human tumour xenografts as a research tool in biology and genetics.

Acquired rearrangement of an amplified epidermal growth factor receptor (EGFR) gene in a human glioblastoma xenograft.

Amplification of the epidermal growth factor receptor (EGFR) occurs in about 40% of human glioblastomas. In half of these cases, rearrangements of the amplified gene result in aberrant transcripts and proteins. The most frequent rearrangement affects the external domain of the receptor and results in nonbinding of ligand and constitutive activity. Less frequent rearrangements involve changes resulting in the loss of cytoplasmic amino acid sequences necessary for downregulation of the receptor following ligand binding. Here we report the development and selection for a rearranged amplified EGF receptor, which lacks cytoplasmic amino acid sequences in a human glioblastoma xenograft. An identical aberration has previously been reported in glioblastoma tissue. The patient tumor material, as well as the first passages of the xenograft showed amplification of the EGFR gene, but no evidence of gene rearrangement or an aberrant transcript. Interphase FISH data show the amplified gene on double minutes. Between passages 3 and 16, the growth rate of the xenograft almost doubled, the rearranged amplicon became dominant, as did the aberrant transcript, indicating selection under these conditions.

Cardiovascular safety of MnDPDP and MnCl2.

PURPOSE: To investigate the apparent discrepancy between expected basic physiological responses at the cellular level and the in vivo behaviour of both MnDPDP and MnCl2 administered i.v. prompted parallel investigations of these substances. MATERIAL AND METHODS: Studies were performed in isolated perfused rat hearts, isolated bovine mesenteric arteries, conscious dogs, and dogs with acute ischaemic heart failure. RESULTS: These studies confirmed that Mn+2 at high concentrations acted as a calcium antagonist inducing negative inotropy. Mn+2 at low concentrations was an effective superoxide scavenger, conserving nitric oxide and facilitating vasodilation. Mn+2 maintained or elevated heart rate (HR) and blood pressure (BP), and did not worsen existing cardiac failure. MnDPDP was about 10 times less potent than MnCl2 in eliciting these cardiovascular responses. CONCLUSION: The ex vivo properties of Mn+2, inducing vasodilation and negative inotropy, are counter-balanced in vivo through the action of 2 mechanisms: extensive plasma protein binding reducing active M+2, and the release of catecholamines which maintain or even raise HR and BP. Taken together with pharmacokinetic factors, including maximal plasma concentrations in humans given the recommended 5 mumol/kg dose, it is concluded that MnDPDP in normal clinical use represents no safety risk to the cardiovascular system.

Mangafodipir (MnDPDP)-and MnCl2-induced endothelium-dependent relaxation in bovine mesenteric arteries.

Mn++ complexed to DPDP (N,N'-dipyridoxylethylenediamine-N,N'-diacetate-5,5'-bis(phosphate) generic name: mangafodipir), abbreviated MnDPDP, acts as an effective contrast enhancing agent for liver MRI. In clinical trials, a commonly reported side effect after i.v. administration of MnDPDP was facial flushing, most probably due to peripheral vasodilation. The present study was conducted to address possible mechanisms to explain the flushing effect. Nitric oxide is known to be stabilized in the presence of both uncomplexed and complexed Mn++ and this stabilization is probably due to the superoxide-scavenging properties of Mn++. The present study has demonstrated that both MnDPDP and MnCl2 relax phenylephrine precontracted bovine mesenteric artery strips in concentration-dependent manner. It was also found that a concentration of 10 microM MnDPDP, MnEDTA or MnCl2 gave approximately the same relaxation response as 0.1 microM acetylcholine. DPDP and EDTA had no appreciable intrinsic relaxation potential Mn(++)-induced relaxation was abolished when the endothelial layer was removed from the arteries. In addition, the Mn(++)-induced relaxation was attenuated by the nitric oxide synthase inhibitor N-nitro-arginine and the putative superoxide anion generator 6-anilino-5,8-quinolinedione, but not by the cyclooxygenase inhibitor indomethacin. Both N-nitro-arginine and 6-anilino-5,8-quinolinedione were found to induce an endothelium-dependent constriction of the bovine mesenteric artery strips. An approximately 2-fold increase in the intracellular concentration of cyclic GMP was detected after the addition of 10 microM MnDPDP or 0.1 microM acetylcholine. The increase in cyclic GMP coincided with the onset of relaxation and was effectively abolished by pretreatment with N-nitro-arginine.(ABSTRACT TRUNCATED AT 250 WORDS)