Central Adrenal Insufficiency and Diabetes Insipidus Misdiagnosed as Severe Depression

A 68 year-old Japanese man, who had been suffering from immobilization and disuse syndrome, was admitted to our hospital for evaluation of polyuria with polyposia, hyponatremia and low blood pressure. His plasma osmolality was greater than that of his urine. His endocrinological examination revealed low levels of plasma adrenocorticotropic hormone (ACTH) and cortisol, and a normal response of ACTH to the corticotrophin-releasing hormone (CRH) challenge. Plasma ACTH did not increase with insulin loading. A low plasma vasopressin (AVP) level and no response of AVP to a 5% saline administration were observed. We diagnosed central adrenal insufficiency with central diabetes insipidus. Six months after starting administration of hydrocortisone and 1-deamino-8D-arginine vasopressin, his psychological symptoms had improved, and 1.5 years after starting treatment, he was able to walk. In conclusion, it is not particularly rare for adrenal insufficiency to be misdiagnosed as depression. However, a correct early diagnosis is necessary, because, if adrenal insufficiency is not definitively diagnosed, the patient’s quality of life diminishes markedly

Effect of Miglitol, an α-Glucosidase Inhibitor, on Postprandial Glucose and Lipid Metabolism in Patients with Type 2 Diabetes

Objective: The effects of miglitol on postprandial glucose and lipid metabolism were investigated in patients with type 2 diabetes mellitus (T2DM) treated with diet alone. Subjects and Methods: A meal tolerance test (MTT) was performed in 26 diabetic patients before and 2 weeks after 150 mg/day miglitol treatment, with the second MTT performed in patients after they had taken a dose of 50 mg miglitol. Results: Miglitol treatment decreased postprandial blood glucose and serum insulin levels 30 and 60 min after meal loading, but there was no change in blood glucose levels at 120 min. In addition, there were no significant decreases in the area under the curve (AUC) of blood glucose and serum insulin levels. However, the AUC of postprandial serum triglycerides and incremental triglycerides decreased significantly, as did the AUC of postprandial incremental remnant-like particle cholesterol. There were no significant changes in total cholesterol, high-density lipoprotein-cholesterol and low-density lipoprotein-cholesterol. Conclusions: Miglitol treatment improves postprandial hyperlipidemia, as well as postprandial hyperglycemia, in patients with T2DM. In T2DM patients treated with α-glucosidase inhibitors alone, measuring blood glucose levels 120 min after a meal may not be the best way to monitor postprandial glucose metabolism

Thermal Hall Effects of Spins and Phonons in Kagome Antiferromagnet Cd-Kapellasite

We have investigated the thermal-transport properties of the kagome antiferromagnet Cd-kapellasite (Cd-K). We find that a field suppression effect on the longitudinal thermal conductivity k_xx sets in below ~25 K, suggesting a large spin contribution k_xx^sp in k_xx. We also find clear thermal Hall signals in the spin liquid phase in all Cd-K samples. The magnitude of the thermal Hall conductivity k_xy shows a significant dependence on the sample's scattering time. On the other hand, the temperature dependence of k_xy is similar in all Cd-K samples; k_xy shows a peak at almost the same temperature of the peak of the phonon thermal conductivity k_xy^ph which is estimated by k_xx at 15 T. These results indicate the presence of a dominant phonon thermal Hall k_xy^ph at 15 T. In addition to k_xy^ph, we find that the field dependence of k_xy at low fields turns out to be non-linear at low temperatures, concomitantly with the appearance of the field suppression of k_xx, indicating the presence of a spin thermal Hall k_xy^sp at low fields. Remarkably, by assembling the k_xx dependene of k_xy^sp data of other kagome antiferromagnets, we find that, whereas k_xy^sp stays a constant in the low-k_xx region, k_xy^sp starts to increase as k_xx does in the high-k_xx region. This k_xx dependence of k_xy^sp indicates the presence of both intrinsic and extrinsic mechanisms in the spin thermal Hall effect in kagome antiferromagnets. Furthermore, both k_xy^ph and k_xy^sp disappear in the antiferromagnetic ordered phase at low fields, showing that phonons alone do not exhibit the thermal Hall effect. A high field above ~7 T induces k_xy^ph, concomitantly with a field-induced increase of k_xx and the specific heat, suggesting a coupling of the phonons to the field-induced spin excitations as the origin of k_xy^ph.Comment: 33 pages, 16 figures; analyses and figures for the heat capacity and the spin thermal Hall effect were adde

Thyroid storm associated with Graves' disease covered by diabetic ketoacidosis: A case report

<p>Abstract</p> <p>Background</p> <p>Thyroid storm is a condition in which multiple organ dysfunction results from failure of the compensatory mechanisms of the body owing to excessive thyroid hormone activity induced by some factors in patients with thyrotoxicosis. While diabetic ketoacidosis (DKA) is an important trigger for thyroid storm, simultaneous development of DKA and thyroid storm is rare.</p> <p>Case presentation</p> <p>A 59-year-old woman with no history of either diabetes mellitus or thyroid disease presented to our hospital because of developing nausea, vomiting and diarrhea for 2 days. Physical examination showed mild disturbance of consciousness, fever, and tachycardia. There were no other signs of thyrotoxicosis. Laboratory studies revealed elevation of random blood glucose and glycosylated hemoglobin, strongly positive of urine acetone, and metabolic acidosis. Since DKA was diagnosed, we initiated the patient on treatment with administration of insulin and adequate fluid replacement. Although the hyperglycemia and acidosis were immediately relieved, the disturbance of consciousness and tachycardia remained persistent. Levels of FT3 and FT4 were extremely high and TSH was below the detectable limit. TRAb was positive. The thyroid storm score of Burch & Wartofsky was 75/140, and the thyroid storm diagnostic criteria of the Japan Thyroid Association were satisfied. Oral administration of thiamazole, potassium iodide and propranolol resulted in immediate relief of the tachycardia.</p> <p>Discussion</p> <p>We encountered a case of thyroid storm associated with Graves' disease covered by DKA. Thyroid storm and DKA are both potentially fatal, and the prognosis varies depending on whether or not these conditions are detected and treated sufficiently early. The thyroid storm diagnostic criteria prepared in 2008 by the Japan Thyroid Association are very simple as compared to the Burch & Wartofsky scoring system for thyroid storm. The Japanese criteria may be useful in the diagnosis of this condition since they enable clinicians to identify a broad range of cases with thyroid storm. When dealing with cases of DKA or thyroid storm, it seems essential to bear in mind the possibility of the coexistence of these two diseases.</p

Superconductivity of the Sr2Ca12Cu24O41Sr_2 Ca_{12} Cu_{24} O_{41} spin ladder system: Are the superconducting pairing and the spin-gap formation of the same origin?

Pressure-induced superconductivity in a spin-ladder cuprate Sr$_2$Ca$_{12}$Cu$_{24}$O$_{41}$ has not been studied on a microscopic level so far although the superconductivity was already discovered in 1996. We have improved high-pressure technique with using a large high-quality crystal, and succeeded in studying the superconductivity using $^{63}$Cu nuclear magnetic resonance (NMR). We found that anomalous metallic state reflecting the spin-ladder structure is realized and the superconductivity possesses a s-wavelike character in the meaning that a finite gap exists in the quasi-particle excitation: At pressure of 3.5GPa we observed two excitation modes in the normal state from the relaxation rate $T_1^{-1}$. One gives rise to an activation-type component in $T_1^{-1}$, and the other $T$-linear component linking directly with the superconductivity. This gapless mode likely arises from free motion of holon-spinon bound states appearing by hole doping, and the pairing of them likely causes the superconductivity.Comment: to be published in Phys. Rev. Let

Outburst of LS V+44 17 Observed by MAXI and RXTE, and Discovery of a Dip Structure in the Pulse Profile

We report on the first observation of an X-ray outburst of a Be/X-ray binary pulsar LS V +44 17/RX J0440.9+4431, and the discovery of an absorption dip structure in the pulse profile. An outburst of this source was discovered by MAXI GSC in 2010 April. It was the first detection of the transient activity of LS V +44 17 since the source was identified as a Be/X-ray binary in 1997. From the data of the follow-up RXTE observation near the peak of the outburst, we found a narrow dip structure in its pulse profile which was clearer in the lower energy bands. The pulse-phase-averaged energy spectra in the 3$-$100 keV band can be fitted with a continuum model containing a power-law function with an exponential cutoff and a blackbody component, which are modified at low energy by an absorption component. A weak iron K$\alpha$ emission line is also detected in the spectra. From the pulse-phase-resolved spectroscopy we found that the absorption column density at the dip phase was much higher than those in the other phases. The dip was not seen in the subsequent RXTE observations at lower flux levels. These results suggest that the dip in the pulse profile originates from the eclipse of the radiation from the neutron star by the accretion column.Comment: 18 pages, 7 figures, accepted for publication in PAS

MAXI GSC observations of a spectral state transition in the black hole candidate XTE J1752-223

We present the first results on the black hole candidate XTE J1752-223 from the Gas Slit Camera (GSC) on-board the Monitor of All-sky X-ray Image (MAXI) on the International Space Station. Including the onset of the outburst reported by the Proportional Counter Array on-board the Rossi X-ray Timing Explorer on 2009 October 23, the MAXI/GSC has been monitoring this source approximately 10 times per day with a high sensitivity in the 2-20 keV band. XTE J1752-223 was initially in the low/hard state during the first 3 months. An anti-correlated behavior between the 2-4 keV and 4-20 keV bands were observed around January 20, 2010, indicating that the source exhibited the spectral transition to the high/soft state. A transient radio jet may have been ejected when the source was in the intermediate state where the spectrum was roughly explained by a power-law with a photon index of 2.5-3.0. The unusually long period in the initial low/hard state implies a slow variation in the mass accretion rate, and the dramatic soft X-ray increase may be explained by a sudden appearance of the accretion disk component with a relatively low innermost temperature (0.4-0.7 keV). Such a low temperature might suggest that the maximum accretion rate was just above the critical gas evaporation rate required for the state transition.Comment: Publication of Astronomical Society of Japan Vol.62, No.5 (2010) [in print

The MAXI Mission on the ISS: Science and Instruments for Monitoring All Sky X-Ray Images

The MAXI (Monitor of All-sky X-ray Image) mission is the first astronomical payload to be installed on the Japanese Experiment Module-Exposed Facility (JEM-EF) on the ISS. It is scheduled for launch in the middle of 2009 to monitor all-sky X-ray objects on every ISS orbit. MAXI will be more powerful than any previous X-ray All Sky Monitor (ASM) payloads, being able to monitor hundreds of AGN. MAXI will provide all sky images of X-ray sources of about 20 mCrab in the energy band of 2-30 keV from observation on one ISS orbit (90 min), about 4.5 mCrab for one day, and about 1 mCrab for one month. A final detectability of MAXI could be 0.2 mCrab for 2 year observations.Comment: 12 pages, 11 figures, accepted for publication in Publications of the Astronomical Society of Japa

Long-term Monitoring of the Black Hole Binary GX 339-4 in the High/Soft State during the 2010 Outburst with MAXI/GSC

We present the results of monitoring the Galactic black hole candidate GX 339-4 with the Monitor of All-sky X-ray Image (MAXI) / Gas Slit Camera (GSC) in the high/soft state during the outburst in 2010. All the spectra throughout the 8-month period are well reproduced with a model consisting of multi-color disk (MCD) emission and its Comptonization component, whose fraction is <= 25% in the total flux. In spite of the flux variability over a factor of 3, the innermost disk radius is constant at R_in = 61 +/- 2 km for the inclination angle of i = 46 deg and the distance of d=8 kpc. This R_in value is consistent with those of the past measurements with Tenma in the high/soft state. Assuming that the disk extends to the innermost stable circular orbit of a non-spinning black hole, we estimate the black hole mass to be M = 6.8 +/- 0.2 M_sun for i = 46 deg and d = 8 kpc, which is consistent with that estimated from the Suzaku observation of the previous low/hard state. Further combined with the mass function, we obtain the mass constraint of 4.3 M_sun < M < 13.3 M_sun for the allowed range of d = 6-15 kpc and i < 60 deg. We also discuss the spin parameter of the black hole in GX 339-4 by applying relativistic accretion disk models to the Swift/XRT data.Comment: 9 pages, 8 figures, accepted for publication in PASJ (Suzaku+MAXI special issue

Bright X-ray flares from the BL Lac object Mrk 421, detected with MAXI in 2010 January and February

Strong X-ray flares from the blazar Mrk 421 were detected in 2010 January and February through the 7 month monitoring with the MAXI GSC. The maximum 2 -- 10 keV flux in the January and February flares was measured as 120 +- 10 mCrab and 164 +- 17 mCrab respectively; the latter is the highest among those reported from the object. A comparison of the MAXI and Swift BAT data suggests a convex X-ray spectrum with an approximated photon index of about 2. This spectrum is consistent with a picture that MAXI is observing near the synchrotron peak frequency. The source exhibited a spectral variation during these flares, slightly different from those in the previous observations, in which the positive correlation between the flux and hardness was widely reported. By equating the halving decay timescale in the January flare, $t_{\rm d} \sim 2.5 \times 10^{4}$ s, to the synchrotron cooling time, the magnetic field was evaluated as B = 0.045 G $(\delta/10)^{-1/3}$, where $\delta$ is the jet beaming factor. Assuming that the light crossing time of the emission region is shorter than the doubling rise time, $t_{\rm r} \lesssim 2 \times 10^{4}$ s, the region size was roughly estimated as $R < 6 \times 10^{15}$ cm $(\delta/10)$. These are consistent with the values previously reported. For the February flare, the rise time, $t_{\rm r} < 1.3 \times 10^{5}$ s, gives a loose upper limit on the size as $R < 4 \times 10^{16}$ cm $(\delta/10)$, although the longer decay time $t_{\rm d} \sim 1.4 \times 10^{5}$ s, indicates B = 0.015 G $(\delta/10)^{-1/3}$, which is weaker than the previous results. This could be reconciled by invoking a scenario that this flare is a superposition of unresolved events with a shorter timescale.Comment: 14 pages, 4 figures, accepted for PASJ (Vol. 62 No. 6