Ileal conduit to small intestine fistula following extensive abdominopelvic resection and radiation for metastatic colon cancer

A woman in her mid-60s presented with decreased output from urostomy, which was an opening from the neobladder (ileal conduit). Presentation was preceded by a 6-month history of alternating faecaluria and increased colostomy output. Laboratory studies were notable for normal anion gap metabolic acidosis. Creatinine level of the colostomy output was 17.7 mg/dL, a finding indicative of the presence of urine in the sample. CT enterography and X-ray loopogram confirmed neobladder to small intestine fistula.Neobladder creation is commonly performed in patients with bladder cancer requiring resection. Fistulas between the neobladder and intestine are observed in fewer than 2.7% of cases. The patient's history of extensive abdominopelvic resection, colostomy creation and radiation likely contributed to fistula development. We highlight the need for a high index of suspicion for a fistula in a patient with a neobladder experiencing recurrent urinary tract infections or a high colostomy output concurrently with low neobladder output.

Multiple Photodetachment of Carbon Anions via Single and Double Core-Hole Creation

We report on new measurements of m-fold photodetachment (m=2-5) of carbon anions via K-shell excitation and ionization. The experiments were carried out employing the photon-ion merged-beams technique at a synchrotron light source. While previous measurements were restricted to double detachment (m=2) and to just the lowest-energy K-shell resonance at about 282 eV, our absolute experimental m-fold detachment cross sections at photon energies of up to 1000 eV exhibit a wealth of new thresholds and resonances. We tentatively identify these features with the aid of detailed atomic-structure calculations. In particular, we find unambiguous evidence for fivefold detachment via double K-hole production.

EBIT Observation of Ar Dielectronic Recombination Lines near the Unknown Faint X-Ray Feature Found in the Stacked Spectrum of Galaxy Clusters

Motivated by possible atomic origins of the unidentified emission line detected at 3.55-3.57 keV in a stacked spectrum of galaxy clusters, an electron beam ion trap (EBIT) was used to investigate the resonant dielectronic recombination (DR) process in highly charged argon ions as a possible contributor to the emission feature. The He-like Ar DR-induced transition 1s22l-1s2l3l' was suggested to produce a 3.62 keV photon near the unidentified line at 3.57 keV and was the starting point of our investigation. The collisional-radiative model NOMAD was used to create synthetic spectra for comparison with both our EBIT measurements and with spectra produced with the AtomDB database/Astrophysical Plasma Emission Code (APEC) used in the Bulbul et al. work. Excellent agreement was found between the NOMAD and EBIT spectra, providing a high level of confidence in the atomic data used. Comparison of the NOMAD and APEC spectra revealed a number of missing features in the AtomDB database near the unidentified line. At an electron temperature of T e = 1.72 keV, the inclusion of the missing lines in AtomDB increases the total flux in the 3.5-3.66 keV energy band by a factor of 2. While important, this extra emission is not enough to explain the unidentified line found in the galaxy cluster spectra.

Near-K-Edge Double and Triple Detachment of the F^{-} Negative Ion: Observation of Direct Two-Electron Ejection by a Single Photon

Double and triple detachment of the F^{-}(1s^{2}2s^{2}2p^{6}) negative ion by a single photon have been investigated in the photon energy range 660 to 1000 eV. The experimental data provide unambiguous evidence for the dominant role of direct photodouble detachment with a subsequent single-Auger process in the reaction channel leading to F^{2+} product ions. Absolute cross sections were determined for the direct removal of a (1s+2p) pair of electrons from F^{-} by the absorption of a single photon.

Measuring the difference in nuclear charge radius of Xe isotopes by EUV spectroscopy of highly charged Na-like ions

The difference in the mean-square nuclear charge radius of xenon isotopes was measured utilizing a method based on extreme ultraviolet spectroscopy of highly charged Na-like ions. The isotope shift of the Na-like D1 (3s 2 S 1/2 - 3p 2 P 1/2) transition between the 124Xe and 136Xe isotopes was experimentally determined using the electron-beam ion-trap facility at the National Institute of Standards and Technology. The mass-shift and the field-shift coefficients were calculated with enhanced precision by the relativistic many-body perturbation theory and multiconfiguration Dirac-Hartree-Fock method. The mean-square nuclear charge radius difference was found to be δ〈r 2〉136,124 = 0.269(42) fm2. Our result has smaller uncertainty than previous experimental results and agrees with the literature values.

Observation of a four-electron Auger process in near-K-edge photoionization of singly charged carbon ions

Single, double, and triple ionization of C(1+) ions by single photons is investigated in the energy range of 286-326 eV, i.e., in the range from the lowest-energy K-vacancy resonances to well beyond the K-shell ionization threshold. Clear signatures of C(1+)(1s2s(2)2p(2) (2)D,(2)P) resonances are found in the triple-ionization channel. The only possible mechanism producing C(4+)(1s(2)) via these resonances is direct triple-Auger decay, i.e., a four-electron process with simultaneous emission of three electrons.

Hemodynamic changes in post-suspension rats during gradual hemorrhage

We examined the changes of hemodynamic parameters in nembutal-anesthetized rats during gradual hemorrhage (2 ml/100 g body weight during 30 min). In control rats blood pressure began to decline starting from 3rd min of bleeding and from 5th min it was accompanied by cardiac deceleration. Hindlimb vascular resistance was only slightly increased up to 15th min (by 20-30%) and then began to grow drastically. Less prominent changes of hemodynamics were observed in post-suspension rats. The results indicate that when activity of sympathetic nervous system is blunted with anesthetic post-suspension rats demonstrate higher hemodynamic stability during acute hemorrhage.

Long-term dynamics of blood pressure in intact and sympathectomized post-suspension rats

Low-frequency dynamics of mean arterial pressure (MAP) and pulse interval (PI) was studied in intact and sympathectomized rats after 2-week tail suspension. Correlation properties of long-term (f<0.8 Hz) MAP fluctuations were analyzed using R/S Hurst method. It was shown that time series of successive increments in MAP level display power-law fractal anticorrelations in wide range of time scales. After sympathectomy and/or suspension averaged Hurst exponents were more close to the value for uncorrelated random process (H=0.5), indicating deterioration of regulatory feedbacks. Besides, a decrease of coherence between MAP and PI in low-frequency range was observed after suspension in both intact and sympathectomized rats, indicating alteration of non-sympathetic cardiovascular control mechanisms.

Effect of tail suspension on haemodynamics in intact and sympathectomized rats

The effect of a 2-week tail suspension on mean arterial pressure (MAP) and pulse interval (PI) was studied in conscious chronically instrumented intact and sympathectomized rats. Sympathectomy was induced by 6-hydroxydopamine (100 mg x kg(-1), i.v.), injected 1 day before, and on days 5 and 10 of suspension. During suspension the intact rats had the same levels of MAP and PI as the intact controls. After release from suspension their MAP did not change: PI decreased (by 9%), but only for 1 h. Sympathectomy augmented the haemodynamic changes after release from suspension: tachycardia (10%) and hypotension (19%) were observed during the entire recording period (2 h). Therefore, in rats, post-suspension hypotension becomes apparent only after elimination of sympathetic influences. In spite of unaltered systemic parameters, intact post-suspension rats showed diminished responses to intravenous administration of tyramine (100 microg x kg(-1)) and phenylephrine (1-2 microg x kg(-1)). In addition, they showed augmented haemodynamic changes associated with natural behaviour. The increase of MAP and the decrease of PI on transition from rest to movement were more pronounced in the intact post-suspension rats than in the control rats (MAP 8.3% vs 4.5%, PI 15% vs 9%). In control rats the spectrum power density of low-frequency (0.0195-0.25 Hz) MAP fluctuations depended only weakly on behavioural activity, whereas in post-suspension intact rats it was profoundly augmented during movements (by 170%). Since the rapid adjustment of haemodynamics to behavioural activity is controlled by the sympathetic nervous system, the unbalanced condition of the cardiovascular system after suspension may reflect an altered sympathetic nerve control of the circulation.

The neurogenic constrictor response of isolated rat saphenous artery is reduced after 2-week tail suspension

Under real or simulated microgravity conditions the control of arterial vascular tone is greatly disturbed. The low arterial vessel reactivity to sympathetic influences may be the cause of an increase in flow in hind limb skeletal muscles in tail-suspended (TS) rats. Our previous experiments with constant pressure perfusion of rat hind limb demonstrated the reduced vasoconstrictor responses to sympathetic nerve stimulation in TS rats. Responses to exogenous noradrenaline depended on the perfusion conditions. It is known that the vessels of various branching orders noticeably differ in nerve density and in sensitivity to vasoconstrictor agonists. So under neurogenic or exogenous noradrenaline influences the vascular resistance may be increased at different levels of vascular bed, thus making the data analysis seriously complicated. This uncertainty may be overcome by investigation of a single vessel isolated from hind limb vascular bed. The saphenous artery, a resistance artery with dense innervation, is a very convenient object for this purpose. Thus, this study was aimed at comparing the effects of 2-week tail suspension upon the constrictor responses of isolated saphenous artery to neurogenic and exogenous noradrenaline stimuli in rats.

Selection of intact fine nerve strands using power spectrum of their electrical noise

Experiments on narcotized cats demonstrated a decrease in noise factor determined as the ratio of power spectrum maximum of electrical noise in a fine nerve strand to the corresponding value of the equivalent resistor in neurofilaments isolated from the sciatic nerve with blocked conduction in comparison with intact control. Noise factor can be used as a criterion for selection of intact fine nerve strands.

Regulation of hemodynamics in sympathectomized rats after adaptation to tail suspension

The organism adapts to actual or simulated microgravity by complex interactions of nervous, hormonal and local control mechanisms. Sympathetic nervous system is believed to play the leading role in this adaptation (Robertson et al. 1994). However, this conclusion seems to be rather deductive, as it has not been proved directly. Chronic sympathectomy provides a straightforward approach to this problem. We have studied the role of sympathetic nervous system in adaptation of cardiovascular system to simulated microgravity by tail suspension in intact and sympathectomized rats.

Dynamics of blood pressure and pulse interval duration in rats after 14 day suspension

At present, the pronounced changes in cardiovascular system observed in microgravity and on returning to 1 g are mostly attributed to the regulatory disturbances. The tail suspension model is used to simulate the effects of microgravity on muscle, bone and, on cardiovascular system of rats. Having in mind all limitations of this method, we decided to use it for analysis of the acute effects of cessation of tail suspension on regulation of cardiovascular system in rats.