Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 362
Filter
1.
Front Chem ; 10: 976635, 2022.
Article in English | MEDLINE | ID: mdl-36092655

ABSTRACT

Flerovium (Fl, element 114) is the heaviest element chemically studied so far. To date, its interaction with gold was investigated in two gas-solid chromatography experiments, which reported two different types of interaction, however, each based on the level of a few registered atoms only. Whereas noble-gas-like properties were suggested from the first experiment, the second one pointed at a volatile-metal-like character. Here, we present further experimental data on adsorption studies of Fl on silicon oxide and gold surfaces, accounting for the inhomogeneous nature of the surface, as it was used in the experiment and analyzed as part of the reported studies. We confirm that Fl is highly volatile and the least reactive member of group 14. Our experimental observations suggest that Fl exhibits lower reactivity towards Au than the volatile metal Hg, but higher reactivity than the noble gas Rn.

2.
Clin Exp Dermatol ; 46(7): 1255-1261, 2021 Oct.
Article in English | MEDLINE | ID: mdl-33899950

ABSTRACT

BACKGROUND: Keloid lesions are characterized by mesenchymal cell proliferation and excessive extracellular matrix deposition. Previous microarray analyses have been performed to investigate the mechanism of keloid development. However, the molecular pathology that contributes to keloid development remains obscure. AIM: To explore the underlying essential molecules of keloids using microarrays. METHODS: We performed microarray analyses of keloid and nonlesional skin tissues both in vivo and in vitro. Gene expression levels were compared between tissues and cells. Quantitative reverse transcription (qRT)-PCR and immunohistochemical staining were used to determine the expression levels of molecules of interest in keloid tissues. RESULTS: Several common molecules were upregulated in both keloid tissues and keloid-lesional fibroblasts. PTPRD and NTM were upregulated both in vivo and in vitro. The genes MDFI and ITGA4 were located at the centre of the gene coexpression network analysis using keloid tissues. qRT-PCR revealed significant expression levels of PTPRD and MDFI in keloid tissues. Immunopathological staining revealed that MDFI-positive cells, which have fibroblast characteristics, were located in the keloid-associated lymphoid tissue (KALT) portion of the keloid tissue. CONCLUSION: Our gene expression profiles of keloids could distinguish the difference between lesional tissue and cultured lesional fibroblasts, and MDFI was found to be commonly expressed in both tissues and cells. Thus, MDFI-positive cells, which were located in the KALT, may play an important role in keloid pathogenesis and thus might be useful for in vitro keloid studies.


Subject(s)
Gene Expression Profiling , Gene Expression , Keloid/genetics , Myogenic Regulatory Factors/genetics , Diagnosis, Differential , Fibroblasts/metabolism , Humans , Immunohistochemistry , Keloid/metabolism , Microarray Analysis , Myogenic Regulatory Factors/metabolism , RNA/analysis , RNA, Messenger/metabolism , Up-Regulation
3.
Appl Radiat Isot ; 164: 109106, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32819495

ABSTRACT

Boron Neutron Capture Therapy (BNCT) is a radiotherapy for the treatment of intractable cancer. In BNCT precise determination of 10B concentration in whole blood sample before neutron irradiation of the patient, as well as accurate neutron dosimetry, is crucial for control of the neutron irradiation time. For this purpose ICP-AES and neutron induced prompt γ-ray analysis are generally used. In Ibaraki Neutron Medical Research Center (iNMRC), an intense proton beam will be accelerated up to 8 MeV, which can also be used for Charged Particle Activation Analysis (CPAA). Thus, in this study, we apply the CPAA utilizing the proton beam to non-destructive and accurate determination of 10B concentration in whole blood sample. A CPAA experiment is performed by utilizing an 8 MeV proton beam from the tandem accelerator of Nuclear Science Research Institute in Japan Atomic Energy Agency. The 478 keV γ-ray of 7Be produced by the 10B(p, α)7Be reaction is used to quantify the 10B in human blood. The 478 keV γ-ray intensity is normalized by the intensities of the 847 keV and 1238 keV γ-rays of 56Co originating from Fe in blood. The normalization methods were found to be linear in the range of 3.27 µg 10B/g to 322 µg 10B/g with correlation coefficients of better than 0.9999.


Subject(s)
Boron/blood , Boron/standards , Boron Neutron Capture Therapy/methods , Calibration , Gamma Rays , Humans , Mass Spectrometry/methods , Radiometry/methods , Radiotherapy Dosage , Reference Standards , Reproducibility of Results , Uncertainty
4.
Phys Med ; 73: 65-72, 2020 May.
Article in English | MEDLINE | ID: mdl-32330813

ABSTRACT

PURPOSE: A reliable model to simulate nuclear interactions is fundamental for Ion-therapy. We already showed how BLOB ("Boltzmann-Langevin One Body"), a model developed to simulate heavy ion interactions up to few hundreds of MeV/u, could simulate also 12C reactions in the same energy domain. However, its computation time is too long for any medical application. For this reason we present the possibility of emulating it with a Deep Learning algorithm. METHODS: The BLOB final state is a Probability Density Function (PDF) of finding a nucleon in a position of the phase space. We discretised this PDF and trained a Variational Auto-Encoder (VAE) to reproduce such a discrete PDF. As a proof of concept, we developed and trained a VAE to emulate BLOB in simulating the interactions of 12C with 12C at 62 MeV/u. To have more control on the generation, we forced the VAE latent space to be organised with respect to the impact parameter (b) training a classifier of b jointly with the VAE. RESULTS: The distributions obtained from the VAE are similar to the input ones and the computation time needed to use the VAE as a generator is negligible. CONCLUSIONS: We show that it is possible to use a Deep Learning approach to emulate a model developed to simulate nuclear reactions in the energy range of interest for Ion-therapy. We foresee the implementation of the generation part in C++ and to interface it with the most used Monte Carlo toolkit: Geant4.


Subject(s)
Deep Learning , Radiobiology , Monte Carlo Method
5.
Phys Med ; 67: 116-122, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31706147

ABSTRACT

PURPOSE: Monte Carlo (MC) simulations are widely used for medical applications and nuclear reaction models are fundamental for the simulation of the particle interactions with patients in ion therapy. Therefore, it is of utmost importance to have reliable models in MC simulations for such interactions. Geant4 is one of the most used toolkits for MC simulation. However, its models showed severe limitations in reproducing the yields measured in the interaction of ion beams below 100 MeV/u with thin targets. For this reason, we interfaced two models, SMF ("Stochastic Mean Field") and BLOB ("Boltzmann-Langevin One Body"), dedicated to simulate such reactions, with Geant4. METHODS: Both SMF and BLOB are semi-classical, one-body approaches to solve the Boltzmann-Langevin equation. They include an identical treatment of the mean-field propagation, on the basis of the same effective interaction, but they differ in the way fluctuations are included. Furthermore, we tested a correction to the excitation energy calculated for the light fragments emerging from the simulations and a simple coalescence model. RESULTS: While both SMF and BLOB have been developed to simulate heavy ion interactions, they show very good results in reproducing the experimental yields of light fragments, up to alpha particles, obtained in the interaction of 12C with a thin carbon target at 62 MeV/u. CONCLUSIONS: BLOB in particular gives promising results and this stresses the importance of integrating it into the Geant4 toolkit.


Subject(s)
Monte Carlo Method , Radiotherapy , Stochastic Processes
6.
Mol Psychiatry ; 22(5): 733-744, 2017 05.
Article in English | MEDLINE | ID: mdl-27595593

ABSTRACT

A long-standing paradigm posits that hypothalamic corticotropin-releasing hormone (CRH) regulates neuroendocrine functions such as adrenal glucocorticoid release, whereas extra-hypothalamic CRH has a key role in stressor-triggered behaviors. Here we report that hypothalamus-specific Crh knockout mice (Sim1CrhKO mice, created by crossing Crhflox with Sim1Cre mice) have absent Crh mRNA and peptide mainly in the paraventricular nucleus of the hypothalamus (PVH) but preserved Crh expression in other brain regions including amygdala and cerebral cortex. As expected, Sim1CrhKO mice exhibit adrenal atrophy as well as decreased basal, diurnal and stressor-stimulated plasma corticosterone secretion and basal plasma adrenocorticotropic hormone, but surprisingly, have a profound anxiolytic phenotype when evaluated using multiple stressors including open-field, elevated plus maze, holeboard, light-dark box and novel object recognition task. Restoring plasma corticosterone did not reverse the anxiolytic phenotype of Sim1CrhKO mice. Crh-Cre driver mice revealed that PVHCrh fibers project abundantly to cingulate cortex and the nucleus accumbens shell, and moderately to medial amygdala, locus coeruleus and solitary tract, consistent with the existence of PVHCrh-dependent behavioral pathways. Although previous, nonselective attenuation of CRH production or action, genetically in mice and pharmacologically in humans, respectively, has not produced the anticipated anxiolytic effects, our data show that targeted interference specifically with hypothalamic Crh expression results in anxiolysis. Our data identify neurons that express both Sim1 and Crh as a cellular entry point into the study of CRH-mediated, anxiety-like behaviors and their therapeutic attenuation.


Subject(s)
Anxiety/metabolism , Corticotropin-Releasing Hormone/deficiency , Hypothalamus/metabolism , Adrenocorticotropic Hormone/metabolism , Amygdala/metabolism , Animals , Corticosterone/blood , Corticotropin-Releasing Hormone/isolation & purification , Corticotropin-Releasing Hormone/metabolism , Female , Glucocorticoids/metabolism , Hypothalamo-Hypophyseal System/metabolism , Mice , Mice, Inbred ICR , Mice, Mutant Strains , Neurons/metabolism , Pituitary Hormone-Releasing Hormones/metabolism , Pituitary-Adrenal System/metabolism , RNA, Messenger/metabolism , Receptors, Corticotropin-Releasing Hormone/genetics , Receptors, Corticotropin-Releasing Hormone/metabolism , Receptors, Glucocorticoid/metabolism
7.
Phys Rev Lett ; 116(7): 071301, 2016 Feb 19.
Article in English | MEDLINE | ID: mdl-26943526

ABSTRACT

The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting massive particles (WIMPs). Results are presented from the second CDMSlite run with an exposure of 70 kg day, which reached an energy threshold for electron recoils as low as 56 eV. A fiducialization cut reduces backgrounds below those previously reported by CDMSlite. New parameter space for the WIMP-nucleon spin-independent cross section is excluded for WIMP masses between 1.6 and 5.5 GeV/c^{2}.

8.
Nature ; 520(7546): 209-11, 2015 Apr 09.
Article in English | MEDLINE | ID: mdl-25855457

ABSTRACT

The chemical properties of an element are primarily governed by the configuration of electrons in the valence shell. Relativistic effects influence the electronic structure of heavy elements in the sixth row of the periodic table, and these effects increase dramatically in the seventh row--including the actinides--even affecting ground-state configurations. Atomic s and p1/2 orbitals are stabilized by relativistic effects, whereas p3/2, d and f orbitals are destabilized, so that ground-state configurations of heavy elements may differ from those of lighter elements in the same group. The first ionization potential (IP1) is a measure of the energy required to remove one valence electron from a neutral atom, and is an atomic property that reflects the outermost electronic configuration. Precise and accurate experimental determination of IP1 gives information on the binding energy of valence electrons, and also, therefore, on the degree of relativistic stabilization. However, such measurements are hampered by the difficulty in obtaining the heaviest elements on scales of more than one atom at a time. Here we report that the experimentally obtained IP1 of the heaviest actinide, lawrencium (Lr, atomic number 103), is 4.96(+0.08)(-0.07) electronvolts. The IP1 of Lr was measured with (256)Lr (half-life 27 seconds) using an efficient surface ion-source and a radioisotope detection system coupled to a mass separator. The measured IP1 is in excellent agreement with the value of 4.963(15) electronvolts predicted here by state-of-the-art relativistic calculations. The present work provides a reliable benchmark for theoretical calculations and also opens the way for IP1 measurements of superheavy elements (that is, transactinides) on an atom-at-a-time scale.

9.
Dis Esophagus ; 28(2): 188-95, 2015.
Article in English | MEDLINE | ID: mdl-24147998

ABSTRACT

To pursue an urgently needed treatment target for esophageal cancer (EC), we investigated the function of the recently discovered melanoma-associated antigen (MAGE)-D4 in squamous cell EC. MAGE-D4 messenger RNA (mRNA) expression was analyzed in nine EC cell lines using quantitative reverse transcription polymerase chain reaction. In 65 surgical specimens of squamous cell EC with no prior neoadjuvant therapy, MAGE-D4 mRNA expression in EC tissues and corresponding normal tissues was analyzed and compared, and evaluated in terms of clinicopathological factors. In representative cases, MAGE-D4 protein distribution was analyzed immunohistochemically. The heterogeneity of MAGE-D4 mRNA expression was confirmed in EC cell lines by quantitative reverse transcription polymerase chain reaction. In surgical specimens, MAGE-D4 mRNA expression was significantly higher in EC tissues than in corresponding normal tissues (P < 0.001). Patients with the highest MAGE-D4 mRNA expression in EC tissues (top quartile, n = 17) had significantly shorter overall survival than patients with low expression (2-year survival: 44% and 73%, respectively, P = 0.006). Univariate analysis identified age (≥65 years), lymphatic involvement, and high MAGE-D4 mRNA expression as significant prognostic factors; high MAGE-D4 mRNA expression was also an independent prognostic factor in multivariable analysis (hazard ratio: 2.194; P = 0.039) and was significantly associated with Brinkman index (P = 0.008) and preoperative carcinoembryonic antigen level (P = 0.002). Immunohistochemical MAGE-D4b expression was consistent with MAGE-D4 mRNA profiling. Our results suggest that MAGE-D4 overexpression influences tumor progression, and MADE-D4 can be a prognostic marker and a potential molecular target in squamous cell EC.


Subject(s)
Antigens, Neoplasm/metabolism , Biomarkers, Tumor/metabolism , Carcinoma, Squamous Cell/metabolism , Esophageal Neoplasms/metabolism , RNA, Messenger/metabolism , Aged , Aged, 80 and over , Antigens, Neoplasm/genetics , Biomarkers, Tumor/genetics , Carcinoma, Squamous Cell/genetics , Cell Line, Tumor , Disease Progression , Esophageal Neoplasms/genetics , Esophageal Squamous Cell Carcinoma , Female , Humans , Male , Middle Aged , Prognosis
10.
Int J Oral Maxillofac Surg ; 44(3): 349-55, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25468631

ABSTRACT

We investigated changes in the sensitivity of cutaneous points and the oral mucosa after sagittal split ramus osteotomy (SSRO) and assessed the differences between SSRO and intraoral vertical ramus osteotomy (IVRO). The subjects included in this study were 46 patients with mandibular prognathism who underwent IVRO (88 rami) and 30 patients who underwent SSRO (59 rami). An objective evaluation of the neurosensory status of each patient was completed preoperatively and at 1, 4, 8, 12, and 24 weeks postoperatively. Other variables studied for each patient included sex, age, magnitude of mandibular setback, and amount of blood loss during surgery. We found that a neurosensory recovery occurred earlier in the oral mucosa than at cutaneous points. The number of oral mucosa points showing reduced neurosensory function and neurosensory disturbance after SSRO was significantly higher than after IVRO at 1, 4, and 8 weeks (P<0.05). The nerve recovery observed after SSRO was delayed for a longer period than that noted in our previous study of IVRO. In conclusion, we found changes in sensitivity at cutaneous points and the oral mucosa after SSRO and assessed the differences between SSRO and IVRO.


Subject(s)
Mouth Mucosa/innervation , Osteotomy, Sagittal Split Ramus , Osteotomy/methods , Postoperative Complications/epidemiology , Prognathism/surgery , Sensation Disorders/epidemiology , Adolescent , Adult , Female , Humans , Male , Middle Aged
11.
Science ; 345(6203): 1491-3, 2014 Sep 19.
Article in English | MEDLINE | ID: mdl-25237098

ABSTRACT

Experimental investigations of transactinoide elements provide benchmark results for chemical theory and probe the predictive power of trends in the periodic table. So far, in gas-phase chemical reactions, simple inorganic compounds with the transactinoide in its highest oxidation state have been synthesized. Single-atom production rates, short half-lives, and harsh experimental conditions limited the number of experimentally accessible compounds. We applied a gas-phase carbonylation technique previously tested on short-lived molybdenum (Mo) and tungsten (W) isotopes to the preparation of a carbonyl complex of seaborgium, the 106th element. The volatile seaborgium complex showed the same volatility and reactivity with a silicon dioxide surface as those of the hexacarbonyl complexes of the lighter homologs Mo and W. Comparison of the product's adsorption enthalpy with theoretical predictions and data for the lighter congeners supported a Sg(CO)6 formulation.

12.
Phys Rev Lett ; 112(24): 241302, 2014 Jun 20.
Article in English | MEDLINE | ID: mdl-24996080

ABSTRACT

We report a first search for weakly interacting massive particles (WIMPs) using the background rejection capabilities of SuperCDMS. An exposure of 577 kg days was analyzed for WIMPs with mass <30 GeV/c(2), with the signal region blinded. Eleven events were observed after unblinding. We set an upper limit on the spin-independent WIMP-nucleon cross section of 1.2×10(-42) cm(2) at 8 GeV/c(2). This result is in tension with WIMP interpretations of recent experiments and probes new parameter space for WIMP-nucleon scattering for WIMP masses <6 GeV/c(2).

13.
Phys Rev Lett ; 112(17): 172501, 2014 May 02.
Article in English | MEDLINE | ID: mdl-24836239

ABSTRACT

The superheavy element with atomic number Z=117 was produced as an evaporation residue in the (48)Ca+(249)Bk fusion reaction at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. The radioactive decay of evaporation residues and their α-decay products was studied using a detection setup that allowed measuring decays of single atomic nuclei with half-lives between sub-µs and a few days. Two decay chains comprising seven α decays and a spontaneous fission each were identified and are assigned to the isotope (294)117 and its decay products. A hitherto unknown α-decay branch in (270)Db (Z = 105) was observed, which populated the new isotope (266)Lr (Z = 103). The identification of the long-lived (T(1/2) = 1.0(-0.4)(+1.9) h) α-emitter (270)Db marks an important step towards the observation of even more long-lived nuclei of superheavy elements located on an "island of stability."

14.
Phys Rev Lett ; 112(4): 041302, 2014 Jan 31.
Article in English | MEDLINE | ID: mdl-24580434

ABSTRACT

SuperCDMS is an experiment designed to directly detect weakly interacting massive particles (WIMPs), a favored candidate for dark matter ubiquitous in the Universe. In this Letter, we present WIMP-search results using a calorimetric technique we call CDMSlite, which relies on voltage-assisted Luke-Neganov amplification of the ionization energy deposited by particle interactions. The data were collected with a single 0.6 kg germanium detector running for ten live days at the Soudan Underground Laboratory. A low energy threshold of 170 eVee (electron equivalent) was obtained, which allows us to constrain new WIMP-nucleon spin-independent parameter space for WIMP masses below 6 GeV/c2.

15.
Phys Rev Lett ; 113(26): 262505, 2014 Dec 31.
Article in English | MEDLINE | ID: mdl-25615317

ABSTRACT

We report on the first measurement of the fission barrier height in a heavy shell-stabilized nucleus. The fission barrier height of 254No is measured to be Bf=6.0±0.5 MeV at spin 15ℏ and, by extrapolation, Bf=6.6±0.9 MeV at spin 0ℏ. This information is deduced from the measured distribution of entry points in the excitation energy versus spin plane. The same measurement is performed for 220Th and only a lower limit of the fission barrier height can be determined: Bf(I)>8 MeV. Comparisons with theoretical fission barriers test theories that predict properties of superheavy elements.

16.
Phys Rev Lett ; 109(1): 012501, 2012 Jul 06.
Article in English | MEDLINE | ID: mdl-23031099

ABSTRACT

The rotational band structure of the Z=104 nucleus (256)Rf has been observed up to a tentative spin of 20ℏ using state-of-the-art γ-ray spectroscopic techniques. This represents the first such measurement in a superheavy nucleus whose stability is entirely derived from the shell-correction energy. The observed rotational properties are compared to those of neighboring nuclei and it is shown that the kinematic and dynamic moments of inertia are sensitive to the underlying single-particle shell structure and the specific location of high-j orbitals. The moments of inertia therefore provide a sensitive test of shell structure and pairing in superheavy nuclei which is essential to ensure the validity of contemporary nuclear models in this mass region. The data obtained show that there is no deformed shell gap at Z=104, which is predicted in a number of current self-consistent mean-field models.

17.
Neuropeptides ; 41(6): 389-97, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17988732

ABSTRACT

Several experiments have revealed an Endogenous Opioid System (EOS)-circadian rhythm. The brain-borne hormone, melatonin (MEL) has been shown to regulate the organism photoperiodic activity and may be implicated in the EOS-circadian rhythm. To explore this hypothesis, we studied the effect of functional pinealectomy on the EOS-circadian rhythm by measuring the immunoreactive content of Met-Enkephalin, Leu-Enkephalin and Synenkephalin in both hypothalamus and hippocampus of the rat brain, using standard radioimmunoassay procedures. Experimental animals exposed to white fluorescent light (WFL) for 15days (<50lux), displayed a disruption of the EOS-circadian rhythm, showing that absence of MEL induced a significant decrease of tissue content of enkephalin peptides at 01:00h during the dark-phase of the 24-h circadian rhythm, when compared to control rats. Functional pinealectomized rats exposed to 4 or 6h period of darkness (used to revert the effects induced by the absence of melatonin) significantly increased the tissue content of ME-IR and LE-IR, when compared to both controls and non-exposed WFL-treated rats. In addition, subcutaneous administration of exogenous melatonin (10, 100, 150, 300, 600microg/kg), in WFL-treated animals produced significant dose-dependent increases of ME-IR in both brain regions tested. Finally, luzindole (melatonin receptor antagonist) administration, was not able to prevent the enkephalin tissue increase, induced with the MEL administration (150microg/kg). This data suggest that MEL not only regulates the EOS-circadian rhythm, but also appears to modulate their synthesis in the rat brain from their respective neurons.


Subject(s)
Brain Chemistry , Circadian Rhythm , Melatonin/physiology , Opioid Peptides/metabolism , Animals , Dose-Response Relationship, Drug , Hippocampus/chemistry , Hypothalamus/chemistry , Light , Melatonin/administration & dosage , Rats
18.
J Neuroendocrinol ; 19(11): 901-6, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17927668

ABSTRACT

An elevation of plasma vasopressin levels has been frequently observed in Meniere's disease patients. However, little is known regarding the mechanism behind this elevation. The plasma vasopressin levels and plasma osmolality were therefore determined in 18 diagnosed Meniere's disease patients and 20 patients with other types of vertigo, who required admission for severe vertigo attacks. All participants were given questionnaires regarding their clinical and psychological status, including their stress levels and depression status, to evaluate environmental stress events. The plasma vasopressin levels of Meniere's disease patients in the acute phase (4.1 +/- 1.37 pg/ml) were significantly higher compared with with those of other vertigo patients in the acute phase (2.1 +/- 0.41 pg/ml) (P < 0.01). The average plasma osmolality of the Meniere's disease group was higher than that of the other vertigo patients group (P < 0.05). No significant difference in reported stress levels, depression status and prevalence of primary headache between the groups was observed. The plasma vasopressin showed no significant correlation with the patients' clinical data (occurrence of emesis or nausea, prevalence of primary headache, depression status and stress). No correlation between the plasma vasopressin and the plasma osmolarity was observed in the Meniere's disease group. These results suggest that the elevation of plasma vasopressin in the acute phase of Meniere's disease is therefore related to the pathogenesis of Meniere's attacks, and the results obtained may provide helpful information for distinguishing between Meniere's disease and other various inner ear diseases.


Subject(s)
Arginine Vasopressin/blood , Meniere Disease/blood , Adult , Aged , Aged, 80 and over , Depression , Female , Humans , Male , Meniere Disease/physiopathology , Middle Aged , Osmolar Concentration , Plasma/chemistry , Quality of Life , Retrospective Studies , Statistics as Topic , Surveys and Questionnaires , Vertigo/blood
19.
J Endocrinol Invest ; 30(6): 513-6, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17646727

ABSTRACT

Magnesium (Mg) deficiency sometimes causes hypocalcemia with impaired PTH secretion although the precise mechanism remains unclear. We examined the PTH secretion in response to physiological hypocalcemic stimuli in a patient with hypomagnesemic hypocalcemia. We adopted sodium bicarbonate infusion test, which we recently developed, to evaluate the PTH response to acute decrease in plasma ionized Ca. The results showed that, before Mg replacement and when the patient was mildly hypocalcemic, absolutely no PTH release to hypocalcemic stimuli was observed. In contrast, the plasma Ca was promptly normalized following the start of Mg replacement, and brisk PTH response to hypocalcemic stimuli was obtained during the same test carried out a week after the Mg replacement. The data in this case thus suggest that: a) the acute regulation of PTH release by plasma ionized Ca is lost in the patient with hypomagnesemic hypocalcemia, and b) Mg deficiency itself is likely to be a primary cause of this disorder because the hormone response was clearly restored after shortterm Mg replacement alone.


Subject(s)
Hypocalcemia/metabolism , Magnesium Deficiency/metabolism , Parathyroid Hormone/metabolism , Adolescent , Adult , Calcium/blood , Dietary Supplements , Eating , Female , Humans , Magnesium/administration & dosage , Magnesium/metabolism , Sodium Bicarbonate/administration & dosage
20.
Kidney Int ; 69(6): 996-1004, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16528249

ABSTRACT

A single intravenous injection of anti-Thy-1 monoclonal antibody (mAb) 1-22-3 is known to cause reversible mesangial proliferative glomerulonephritis. However, mAb 1-22-3 injection followed by unilateral nephrectomy leads to progressive glomerulosclerosis and tubulointerstitial change with an irreversible course. To identify genes that play an important role in the irreversible progression of renal injury, we used microarray technology to identify differences in gene expression between these models. Rats were intravenously injected with mAb 1-22-3 1 week after unilateral nephrectomy (irreversible model) or a sham operation (reversible model), and rats were killed on days 4, 7, 14, 42, and 56 after the injection. complementary DNA probes prepared from kidney messenger RNAs were hybridized with oligonucleotide microarrays containing 4854 rat genes. The microarray identified 189 differentially expressed genes, having at least a two-fold difference in expression level between the two models, and they were classified into five clusters. One of the clusters consisted of genes whose expression was markedly upregulated in the irreversible model. This cluster included the genes encoding osteopontin, kidney injury molecule-1, and thymosin beta10. Increased expression of thymosin beta10 was localized mainly in macrophages in the fibrotic interstitium, and upregulation of thymosin beta10 expression was also observed in a unilateral ureteral obstruction model. The microarray analysis yielded information on the molecular mechanisms responsible for the difference in disease progression between the reversible and irreversible model of anti-Thy-1 nephritis. Thymosin beta10 may play an important role in the progression of kidney disease.


Subject(s)
Disease Models, Animal , Multigene Family/genetics , Nephritis/genetics , Nephritis/immunology , Oligonucleotide Array Sequence Analysis , Animals , Cell Adhesion Molecules/analysis , Cell Adhesion Molecules/genetics , Disease Progression , Female , Gene Expression Profiling , Gene Expression Regulation , Immunohistochemistry , Isoantibodies , Kidney/chemistry , Macrophages/chemistry , Membrane Proteins/analysis , Membrane Proteins/genetics , Nephritis/chemically induced , Osteopontin , RNA, Messenger/analysis , RNA, Messenger/genetics , Rats , Rats, Wistar , Reverse Transcriptase Polymerase Chain Reaction , Sialoglycoproteins/analysis , Sialoglycoproteins/genetics , Thymosin/analysis , Thymosin/genetics , Thymosin/physiology
SELECTION OF CITATIONS
SEARCH DETAIL
...