Translational repression of E2F1 mRNA in carcinoma in situ and normal testis correlates with expression of the miR-17-92 cluster.
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Animals↗
Biomedical subjects
M A Hansen
Publications and source records attributed to M A Hansen.
Identification of genes differentially expressed in testes containing carcinoma in situ.
Virtually all testicular germ cell tumours originate from a common precursor, the carcinoma in situ (CIS) cell. The precise nature of the molecular mechanisms leading to CIS remains largely unknown. We performed the first systematic analysis of gene expression in testis with CIS compared to normal testis by the differential display (DDRT-PCR) method, with subsequent analysis by RT-PCR and in situ hybridization (ISH). In tissue containing CIS we identified overexpression of 28 mRNA, some previously reported in CIS and a number of genes not previously described in germ cell neoplasia, including the novel expressed sequence tag (EST) OIC1 (Overexpressed In CIS). The genes could be grouped functionally into genes involved in cell growth, proliferation, differentiation, immunological response, and genes with unknown biological function. Examples of overexpressed genes are SFRP1 that is involved in Wnt signalling and IGFBP6, which is of importance for fetal growth and inhibits cell growth through insulin-like growth factor-II. ISH analysis showed that both mRNA were localized to CIS cells. The results of our search for differentially expressed genes in CIS demonstrated a number of genes linked to testicular development (e.g. DCN, IGFBP6, SFRP1, SALL1), supporting our hypothesis that the origin of CIS is probably associated with disturbances of the fetal development of the testis.
Adolescent↗
In-situ bypass surgery on arteriographically invisible vessels detected by Doppler-ultrasound for limb salvage.
AIM: The aim of this paper was to evaluate our primary experience with bypass surgery on arteries only visible on Doppler-ultrasound in patients suffering from critical lower limb ischemia. METHODS: During a study period of 10 months, Doppler-ultrasound routinely supplemented digital subtraction arteriography (DSA) whenever it failed to reveal patent runoff vessels suitable for in-situ saphenous vein bypass surgery. If an arteriographically invisible runoff artery was detected on Doppler-ultrasound and the patient was eligible for surgery, a bypass procedure was performed. All patients were facing a lower limb amputation due to critical limb ischemia (tissue loss, SVS/ISCV-category 5). Postoperatively the patients were followed according to a standard graft surveillance program, including clinical examination, ankle pressure measurements and a color Doppler-ultrasound at discharge and after 1, 6 and 12 months. RESULTS: Fifty-one in-situ saphenous vein bypasses were performed, 5 (10%) on arteriographically occult runoff vessels detected only on Doppler-ultrasound. After a 12-month follow-up, 3 bypasses were still patent and only one patient had an amputation. One bypass occluded after 6 months but the patient stayed asymptomatic. CONCLUSIONS: Doppler-ultrasound permits in-situ by-pass surgery on arteriographically invisible vessels reducing the proportion of inoperable patients by 10%.
Adult↗
Ultrasound contrast-agent improves imaging of lower limb occlusive disease.
OBJECTIVES: to evaluate if ultrasound contrast-agent infusion could improve duplex-ultrasound imaging of peripheral arterial disease (PAD) and increase the agreement with digital subtraction arteriography (DSA). DESIGN: prospective and consecutive study. MATERIAL: of 60 consecutive PAD patients, 15 were found to have an inconclusive duplex-ultrasound scan of the trifurcation and were included in the study. All 15 patients (53% male) were scheduled for DSA, all being candidates for vascular surgery due to claudication (n = 3, 20%), rest pain (n = 5, 33%) and tissue loss (n = 7, 47%). METHODS: on the day before DSA, a duplex-ultrasound scan of the trifurcation was performed. If the duplex-ultrasound scan was found inconclusive, it was repeated during continuous ultrasound contrast-agent infusion. DSA was performed unaware of the duplex-ultrasound results and served as the gold standard. RESULTS: after contrast-agent administration, the number of inconclusively diagnosed segments was significantly reduced by 26 (70%), from 37 to 11(p < 0.001). In 19 segments (73%) contrast-agent infusion changed the diagnosis in accordance with the DSA (p < 0.05). Values of sensitivity and positive predictive value were improved from 0.20 (0.04-0.62) to 0.47 (0.26-0.69) and 0.50 (0.10-0.91) to 0.80 (0.49-0.93), respectively. Specificity and negative predictive value were unchanged. Agreement between duplex-ultrasound and DSA were improved from poor (kappa = 0.18 (95% CI: 0-0.82)) to moderate (kappa = 0.45 (0.17-0.74)) (p = 0.44). CONCLUSION: ultrasound contrast-agents improve the diagnostic ability of duplex-ultrasound when scanning difficult arterial segments in patients suffering from PAD.
Adult↗
Germ cell differentiation-dependent and stage-specific expression of LANCL1 in rodent testis.
LANCL1 (LanC-like protein 1) is related to the bacterial LanC (lanthionine synthetase C) family, which is involved in the biosynthesis of antimicrobial peptides. Highest expression levels of LANCL1 are found in testes and brain, two organs that exist behind blood-tissue barriers. In the mouse, the establishment of an impermeable blood-testis barrier occurs between day 10-16 post natal (pn). Differential display analysis showed that the expression level of LANCL1 mRNA in mouse testes was very low until day 16 pn, but increased gradually from day 16 pn to reach a maximum on days 22-24 pn followed by a slight reduction from day 26 pn to adult animals. Thus, the expression of LANCL1 mRNA is initiated following the establishment of the blood-testis barrier. In situ hybridisation revealed that LANCL1 mRNA was induced in diplotene spermatocytes, which appear for the first time in mouse testes between days 18 and 20 pn, verifying the expression profile determined by differential display. LANCL1 mRNA level remained high in the meiotic division phase and in early round spermatids, but was down regulated in elongating spermatids and it was undetectable in step 9 elongating spermatids in stage IX (as defined by Russel et al., 1990). The steady decrease in expression level from round spermatids in stage I to elongating spermatids in stage IX suggested that LANCL1 mRNA was not transcribed in spermatids. LANCL1 expression in rat testes was initiated already in pachytene spermatocytes in stage IX, but otherwise similar to mouse.
Animals↗
Posttranscriptional modifications in the A-loop of 23S rRNAs from selected archaea and eubacteria.
Posttranscriptional modifications were mapped in helices 90-92 of 23S rRNA from the following phylogenetically diverse organisms: Haloarcula marismortui, Sulfolobus acidocaldarius, Bacillus subtilis, and Bacillus stearothermophilus. Helix 92 is a component of the ribosomal A-site, which contacts the aminoacyl-tRNA during protein synthesis, implying that posttranscriptional modifications in helices 90-92 may be important for ribosome function. RNA fragments were isolated from 23S rRNA by site-directed RNase H digestion. A novel method of mapping modifications by analysis of short, nucleotide-specific, RNase digestion fragments with Matrix Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS) was utilized. The MALDI-MS data were complemented by two primer extension techniques using reverse transcriptase. One technique utilizes decreasing concentrations of deoxynucleotide triphosphates to map 2'-O-ribose methylations. In the other, the rRNA is chemically modified, followed by mild alkaline hydrolysis to map pseudouridines (psis). A total of 10 posttranscriptionally methylated nucleotides and 6 psis were detected in the five organisms. Eight of the methylated nucleotides and one psi have not been reported previously. The distribution of modified nucleotides and their locations on the surface of the ribosomal peptidyl transferase cleft suggests functional importance.
Bacillus subtilis↗
Severe vaginal bleeding treated with a stent graft.
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Acute Disease↗
Ultrasound imaging of infrainguinal arterial disease has a high interobserver agreement.
OBJECTIVES: to evaluate and compare the operator dependency of duplex ultrasound and digital subtraction arteriography (DSA) in patients suffering from chronic lower limb ischaemia. DESIGN: prospective and blinded validation study. MATERIAL: twenty-six consecutive patients (13 male and 13 females) with severe claudication (n=6, 23%), rest pain (n=7, 27%) or tissue loss (n=13, 50%). METHODS: two physicians independently performed a duplex scan of the lower limb from groin to foot (15 segments). Segments were classified as insignificantly (<50% stenosis) or significantly (>50% stenosis or occlusion) diseased. DSA was performed within 24h of the duplex scanning and was independently reported by two radiologists in the same manner. Interobserver agreement was assessed for both diagnostic methods. After 10 months the arteriograms were reassessed and the intraobserver agreement calculated. RESULTS: for the limb as a whole the interobserver agreement was good and similar for both duplex and DSA, with kappa-values of 0.79 (95%-CI: 0.72-0.86) and 0.80 (0.74-0.87). In the femoral, crural and pedal segments the interobserver agreement was similar for both methods. The intraobserver agreement between the two DSA readings was 0.84 (0.79-0.90). CONCLUSION: ultrasound is comparable to arteriography when visualising arterial occlusive disease in patients with chronic lower limb ischaemia.
Adult↗
Common carotid artery pseudoaneurysm treated with a stent-graft.
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Adult↗
Pre- and postsynaptic actions of ATP on neurotransmission in rat submandibular ganglia.
The pre- and postsynaptic actions of exogenously applied ATP were investigated in intact and dissociated parasympathetic neurones of rat submandibular ganglia. Nerve-evoked excitatory postsynaptic potentials (EPSPs) were not inhibited by the purinergic receptor antagonists, suramin and pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), or the desensitising agonist, alpha,beta-methylene ATP. In contrast, EPSPs were abolished by the nicotinic acetylcholine receptor antagonists, hexamethonium and mecamylamine. Focal application of ATP (100 microM) had no effect on membrane potential of the postsynaptic neurone or on the amplitude of spontaneous EPSPs. Taken together, these results suggest the absence of functional purinergic (P2) receptors on the postganglionic neurone in situ. In contrast, focally applied ATP (100 microM) reversibly inhibited nerve-evoked EPSPs. Similarly, bath application of the non-hydrolysable analogue of ATP, ATP gamma S, reversibly depressed EPSPs amplitude. The inhibitory effects of ATP and ATP gamma S on nerve-evoked transmitter release were antagonised by bath application of either PPADS or suramin, suggesting ATP activates a presynaptic P2 purinoceptor to inhibit acetylcholine release from preganglionic nerves in the submandibular ganglia. In acutely dissociated postganglionic neurones from rat submandibular ganglia, focal application of ATP (100 microM) evoked an inward current and subsequent excitatory response and action potential firing, which was reversibly inhibited by PPADS (10 microM). The expression of P2X purinoceptors in wholemount and dissociated submandibular ganglion neurones was examined using polyclonal antibodies raised against the extracellular domain of six P2X purinoceptor subtypes (P2X(1-6)). In intact wholemount preparations, only the P2X(5) purinoceptor subtype was found to be expressed in the submandibular ganglion neurones and no P2X immunoreactivity was detected in the nerve fibres innervating the ganglion. Surprisingly, in dissociated submandibular ganglion neurones, high levels of P2X(2) and P2X(4) purinoceptors immunoreactivity were found on the cell surface. This increase in expression of P2X(2) and P2X(4) purinoceptors in dissociated submandibular neurones could explain the increased responsiveness of the neurones to exogenous ATP. We conclude that disruption of ganglionic transmission in vivo by either nerve damage or synaptic blockade may up-regulate P2X expression or availability and alter neuronal excitability.
Acetylcholine↗
Validity evidence for using a general critical thinking test to measure nursing students' critical thinking.
This study examined validity evidence for using a general test of critical-thinking skills and dispositions to measure nursing students' critical-thinking abilities. Content evidence indicated strong support for the theoretical framework underlying the test but less support for the way in which the critical-thinking constructs were specifically measured. Scores related to critical-thinking skills demonstrated significant but low correlations with grade point averages, were moderately correlated with SAT scores, and were uncorrelated with scores related to critical-thinking dispositions. The evidence suggests that nursing programs may need to reconsider how critical thinking should be measured and evaluated.
Adult↗
Staging uterine cervical carcinoma with low-field MR imaging.
PURPOSE: To assess the validity of low-field MR in staging cervical cancer compared to clinical staging. MATERIAL AND METHODS: A total of 95 women entered the study over a 3-year period. MR examinations with a 0.1 T resistive magnet using a body coil and clinical staging according to the FIGO recommendations (1988) were performed within 2 weeks from clinical diagnosis. T1- and T2-weighted sequences were obtained in transversal and sagittal acquisitions, and an additional T1 before and after contrast (randomisation to 0.1 or 0.3 mmol/kg b.w. gadodiamide). Treatment decisions on surgery or radiation therapy were made solely on the clinical staging. RESULTS: Sixty-one patients were found to be eligible for surgery. In 5 women, the pathological results revealed a more advanced stage of the disease than assessed by clinical staging. MR correctly staged 4 of the 5 but otherwise tended to overstate the disease. Contrast enhancement significantly reduced this trend (p<0.05) regardless of the contrast medium dose used. Divided into two groups, an operable (less than stage 2b) and an inoperable group (more than stage 2a), the clinical staging correctly classified 57 patients (accuracy 92%) compared to 52 patients with MR using contrast enhancement (accuracy 84%). The specificity was no higher than 31%, whereas the reproducibility of the MR assessment was fairly good with kappa values around 0.65 for both intra- and inter-observer variations. CONCLUSION: In the present set-up, clinical assessment was superior to low-field MR in staging cervical cancer. When using contrast enhancement, the staging accuracies of low-field MR were comparable to the ones reported for techniques with higher tesla values, whereas the specificity and reproducibility errors were lower. The method, therefore, needs to be optimised.
Adenocarcinoma↗
Distribution of purinergic P2X receptors in the rat heart.
The distribution of P2X purinergic receptor subtypes has been determined in relation to nerve varicosities in the rat heart with immunohistochemistry. Large clusters (about 1 microm diameter) of co-localised and sometimes co-extensive P2X1 and P2X3 receptors were found at sites of tyrosine hydroxylase (TH) positive axon varicosities in the atrium and the ventricle. Varicosities that were labelled with antibodies to the synaptic vesicle epitope SV2 were frequently labelled also with antibodies to P2X3, P2X5 and P2X6 but not always with antibodies to P2X1. Especially prominent were large numbers of small clusters (about 400 nm diameter) of co-localised P2X2 and P2X5 receptors on the sarcolemma unrelated to nerves at all. During development the 1 day-old heart possessed an abundance of co-localised P2X2 and P2X5 small receptor clusters on the sarcolemma. These observations are discussed in relation to the role of purinergic receptors in the mammalian heart.
Adenosine Triphosphate↗
P2X (purinergic) receptor distributions in rat blood vessels.
The distribution of purinergic (P2X1 and P2X2) receptors on smooth muscle cells in relation to autonomic nerve varicosities in rat blood vessels has been determined using immunofluorescence and confocal microscopy. P2X1 and P2X2 receptors were visualised using rabbit polyclonal antibodies against the extracellular domain of the receptors and varicosities visualised using a mouse monoclonal antibody against the ubiquitous synaptic vesicle proteoglycan SV2. Two size classes of P2X1 receptor clusters were observed on the smooth muscle cells of mesenteric, renal, and pulmonary arteries as well as in the aorta and in veins: a large approximately elliptical cluster 1.32+/-0.21 microm long and 0.96+/-0.10 microm in diameter; and a smaller spherical cluster with a diameter of 0.32+/-0.05 microm. The latter occurred throughout the media of arteries of all sizes, whereas the former were restricted to the adventitial surface of the media and to endothelial cells, except for the pulmonary artery, in which large receptor clusters were found throughout the media of the vessel. At the adventitial surface, the large clusters are in general located beneath SV2 labelled varicosities. None of the small clusters was associated with varicosities. Three-dimensional reconstruction of the P2X and SV2 labelling at individual varicosities showed that the varicosities were immediately apposed to the P2X receptor clusters. P2X2 receptors were located on nerves and on endothelial cells. They were also found in low density on the smooth muscle cells in the media. These observations are discussed in relation to the mechanism of purinergic transmission to the smooth muscle cells of blood vessels.
Animals↗
Identification and localisation of ATP P2X receptors in rat midbrain.
P2X receptors that are gated by extracellular ATP are among the few known examples of ligand-gated cation-selective channels. There have been seven cloned proteins identified to date as members of the P2X receptor family in a wide range of tissues from the peripheral and central nervous systems and from many species. To determine the distribution of the P2X subtypes in the rat midbrain, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE)/Western blotting was combined with immunolocalisation using confocal microscopy. Subtypes P2X1-6 were detected in the periaqueductal gray area and the ependymal layer bordering the ventricle with a widespread distribution.
Animals↗
Analysis of novel P2X subunit-specific antibodies in rat cardiac and smooth muscle.
P2X receptors are cation-selective channels gated by extracellular adenosine triphosphate (ATP). There are relatively few known types of ligand-gated receptors. In vertebrates they include acetylcholine (Ach), 5-hydroxytryptamine (5-HT), gamma-aminobutyric acid (GABA), glycine, and glutamate as well as ATP. Ach, 5-HT, GABA and glycine ligand-gated receptors are related in evolutionary terms, while glutamate and ATP receptors form separate groups. There have been seven cloned proteins identified to date as members of the P2X receptor family in a wide range of cells and species. We have carried out hydropathy investigations and sequence comparisons of each of the seven subunits in order to examine the putative transmembrane and cysteine-rich extracellular domains. Probable locations of disulphide bridges are consistent with there being two separate extracellular folding domains. Assessment of the putative surface-accessible regions was used to select small localised amino acid segments in nonglycosylated regions for raising antibodies against each of the P2X receptor subunits. To test the specificity of these novel P2X receptor antibodies and their presence in cardiac and smooth muscle, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE)/Western blotting was undertaken in homogenised rat heart, bladder, kidney, and vas deferens.
Amino Acid Sequence↗
The association between low bone mass at the menopause and cardiovascular mortality.
BACKGROUND: Low bone mineral density in late postmenopausal women has been associated with increased nontrauma mortality. We investigated whether bone mass in women soon after menopause was also associated with the risk of mortality in later life. METHODS: Between 1977 and 1988, two samples of healthy women were enrolled; one group soon after the menopause (age 50 +/- 2 years [mean +/- SD], n = 309) and another later after menopause (age 70 +/- 2 years, n = 754). The baseline visit included a medical examination and a measurement of bone mineral content in the distal forearm. In 1994, vital status was checked. All causes of death were registered, excluding those that were due to trauma or suicide. Multivariate relative risks (RR) and 95% confidence intervals (CI) were determined. RESULTS: In the early postmenopausal group, each decrease of one SD (0.4 g/cm) in bone mineral content was associated with a 43% increase in mortality (RR = 1.4; 95% CI 1.0 to 2.0; P < 0.05). When only cardiovascular death was considered, the relative risk of dying within 17 years of the menopause was increased 2.3-fold (95% CI 1.0 to 5.3; P < 0.05). Correspondingly, a 70-year-old woman with a bone mineral content 1 SD below the mean for her age had a 1.8-fold increased risk of dying from cardiovascular disease (95% CI 1.0 to 3.2; P = 0.06). Expressed as quartiles, women with bone mass in the lowest quartile had twice the risk of cardiovascular death compared with those in the highest quartile. A prevalent vertebral compression fracture in the late postmenopausal group was independently associated with cardiovascular death (RR = 2.0; 95% CI 1.4 to 3.3; P = 0.004). CONCLUSION: Low bone mineral content at the menopause is a risk factor for increased mortality in later life, especially from cardiovascular disease.
Bone Density↗
Development of P2X receptor clusters on smooth muscle cells in relation to nerve varicosities in the rat urinary bladder.
Postnatal development of the distribution of different isoforms of purinergic (P2X) receptors on smooth muscle cells in relation to the development of the innervation of the cells by nerve varicosities in the rat urinary bladder has been determined with immunofluorescence and confocal microscopy. Antibodies against the extracellular domains of the P2X(1) to P2X(6) receptors were used to detect the receptors in the bladder. Several other antibodies were used to identify sympathetic varicosities and Schwann cells. At one day postnatal (D1) there were few strings of varicosities denoting isolated axons, with most axons confined to large nerve trunks. Small size clusters of P2X(1) to P2X(6) receptor subtypes (about 0.4 microm diameter) were observed in the muscle which were independent of each other, and sometimes juxtaposed to the rare isolated varicosity strings. At D4 large numbers of strings of varicosities could be discerned throughout the detrusor. Most of these clouds of small P2X(1) to P2X(6) receptor clusters in their immediate vicinity. Some of these were colocalised with the varicosities, which were of parasympathetic origin as they failed to counter-stain with antibodies to tyrosine hydroxylase. Up to D14 there was a gradual coalescence of many of the isolated P2X(1-6) small receptor clusters so that they became colocalized, often at varicosities. Most of the varicosities in isolated strings possessed receptor clusters at this time. By D21 it was rare to find varicosity strings in the detrusor that were not either in close juxtaposition with P2X small receptor clusters or possessing such clusters in colocalization. However, large numbers of small P2X receptor clusters, many of which consisted of a mixture of isoforms, could be found spatially unrelated to nerve varicosities throughout the detrusor muscle. In the adult, single axons were either coextensive with one or more isoforms of P2X receptor clusters or these were immediately juxtaposed to the axons so that is was rare to find a varicosity that did not possess a receptor cluster. However, different combinations of colocalized P2X receptor isoforms could still be discerned in small clusters unrelated to varicosities. These observations are discussed in relation to the mechanism of formation of the receptor clusters and their migration beneath parasympathetic varicosities during development.
Animals↗