Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at sqrt[s]=510 GeV in p[over →]+p[over →] Collisions

We present measurements of the cross section and double-helicity asymmetry A_{LL} of direct-photon production in p[over →]+p[over →] collisions at sqrt[s]=510  GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at sqrt[s]=510  GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range 0.02<x<0.08, with direct sensitivity to the sign of the gluon contribution.

Probing Gluon Spin-Momentum Correlations in Transversely Polarized Protons through Midrapidity Isolated Direct Photons in p^{↑}+p Collisions at sqrt[s]=200 GeV

Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct photons in p^{↑}+p collisions at sqrt[s]=200  GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a 50-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.

Nuclear Dependence of the Transverse Single-Spin Asymmetry in the Production of Charged Hadrons at Forward Rapidity in Polarized p+p, p+Al, and p+Au Collisions at sqrt[s_{NN}]=200 GeV

We report on the nuclear dependence of transverse single-spin asymmetries (TSSAs) in the production of positively charged hadrons in polarized p^{↑}+p, p^{↑}+Al, and p^{↑}+Au collisions at sqrt[s_{NN}]=200  GeV. The measurements have been performed at forward rapidity (1.4<η<2.4) over the range of transverse momentum (1.8<p_{T}<7.0  GeV/c) and Feynman x (0.1<x_{F}<0.2). We observed positive asymmetries for positively charged hadrons in p^{↑}+p collisions, and significantly reduced asymmetries in p^{↑}+A collisions. These results reveal a nuclear dependence of TSSAs for charged-hadron production in a regime where perturbative techniques are applicable. These results provide new opportunities to use p^{↑}+A collisions as a tool to investigate the rich phenomena behind TSSAs in hadronic collisions and to use TSSAs as a new handle in studying small-system collisions.

Pseudorapidity Dependence of Particle Production and Elliptic Flow in Asymmetric Nuclear Collisions of p+Al, p+Au, d+Au, and ^{3}He+Au at sqrt[s_{NN}]=200 GeV

Asymmetric nuclear collisions of p+Al, p+Au, d+Au, and ^{3}He+Au at sqrt[s_{NN}]=200  GeV provide an excellent laboratory for understanding particle production, as well as exploring interactions among these particles after their initial creation in the collision. We present measurements of charged hadron production dN_{ch}/dη in all such collision systems over a broad pseudorapidity range and as a function of collision multiplicity. A simple wounded quark model is remarkably successful at describing the full data set. We also measure the elliptic flow v_{2} over a similarly broad pseudorapidity range. These measurements provide key constraints on models of particle emission and their translation into flow.

Measurements of Multiparticle Correlations in d+Au Collisions at 200, 62.4, 39, and 19.6 GeV and p+Au Collisions at 200 GeV and Implications for Collective Behavior

Recently, multiparticle-correlation measurements of relativistic p/d/^{3}He+Au, p+Pb, and even p+p collisions show surprising collective signatures. Here, we present beam-energy-scan measurements of two-, four-, and six-particle angular correlations in d+Au collisions at sqrt[s_{NN}]=200, 62.4, 39, and 19.6 GeV. We also present measurements of two- and four-particle angular correlations in p+Au collisions at sqrt[s_{NN}]=200  GeV. We find the four-particle cumulant to be real valued for d+Au collisions at all four energies. We also find that the four-particle cumulant in p+Au has the opposite sign as that in d+Au. Further, we find that the six-particle cumulant agrees with the four-particle cumulant in d+Au collisions at 200 GeV, indicating that nonflow effects are subdominant. These observations provide strong evidence that the correlations originate from the initial geometric configuration, which is then translated into the momentum distribution for all particles, commonly referred to as collectivity.

Nuclear Dependence of the Transverse-Single-Spin Asymmetry for Forward Neutron Production in Polarized p+A Collisions at sqrt[s_{NN}]=200 GeV

During 2015, the Relativistic Heavy Ion Collider (RHIC) provided collisions of transversely polarized protons with Au and Al nuclei for the first time, enabling the exploration of transverse-single-spin asymmetries with heavy nuclei. Large single-spin asymmetries in very forward neutron production have been previously observed in transversely polarized p+p collisions at RHIC, and the existing theoretical framework that was successful in describing the single-spin asymmetry in p+p collisions predicts only a moderate atomic-mass-number (A) dependence. In contrast, the asymmetries observed at RHIC in p+A collisions showed a surprisingly strong A dependence in inclusive forward neutron production. The observed asymmetry in p+Al collisions is much smaller, while the asymmetry in p+Au collisions is a factor of 3 larger in absolute value and of opposite sign. The interplay of different neutron production mechanisms is discussed as a possible explanation of the observed A dependence.

Centrality-Dependent Modification of Jet-Production Rates in Deuteron-Gold Collisions at √[s(NN)]=200 GeV

Jet production rates are measured in p+p and d+Au collisions at sqrt[s_{NN}]=200  GeV recorded in 2008 with the PHENIX detector at the Relativistic Heavy Ion Collider. Jets are reconstructed using the R=0.3 anti-k_{t} algorithm from energy deposits in the electromagnetic calorimeter and charged tracks in multiwire proportional chambers, and the jet transverse momentum (p_{T}) spectra are corrected for the detector response. Spectra are reported for jets with 12<p_{T}<50  GeV/c, within a pseudorapidity acceptance of |η|<0.3. The nuclear-modification factor (R_{dAu}) values for 0%-100% d+Au events are found to be consistent with unity, constraining the role of initial state effects on jet production. However, the centrality-selected R_{dAu} values and central-to-peripheral ratios (R_{CP}) show large, p_{T}-dependent deviations from unity, challenging the conventional models that relate hard-process rates and soft-particle production in collisions involving nuclei.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV

We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

Nuclear chemistry. Synthesis and detection of a seaborgium carbonyl complex

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.

Minimally invasive removal of a recurrent lumbar herniated nucleus pulposus by the small incised microendoscopic discectomy interlaminar approach

In this report, we introduce two cases of recurrent herniated nucleus pulposus (HNP) at L5-S1 that were successfully removed using the small incised microendoscopic discectomy (sMED) technique, proposed by Dezawa and Sairyo in 2011. sMED was performed via the interlaminar approach with a percutaneous endoscope. The patients had previously underdone microendoscopic discectomy for HNP. For the recurrent HNP, the sMED interlaminar approach was selected because the HNP occurred at the level of L5-S1; the percutaneous endoscopic transforaminal approach was not possible for anatomical reasons. To perform sMED via the interlaminar approach, we employed new, specially made devices to enable us to use this technique. In conclusion, sMED is the most minimally invasive approach available for HNP, and its limitations have been gradually eliminated with the introduction specially made devices. In the near future, percutaneous endoscopic surgery could be the gold standard for minimally invasive disc surgery.

1,25-Dihydroxyvitamin D(3) prevents the conversion of adipose tissue into fibrous tissue in skin exposed to chronic UV irradiation

The hormonally active form of vitamin D (1,25(OH)2D3) is known to be a physiological regulator of the proliferation and differentiation of skin cells including keratinocytes, fibroblasts, and adipocytes. In the present study, the efficacy of 1,25(OH)2D3 on the conversion of adipose tissue to fibrous tissue in photodamaged skin was investigated in a murine animal model. Groups of hairless mice were exposed to solar-simulating UV irradiation (lambdamax, 352 nm; UV distribution: 300-310 nm, 0.9%; 310-320 nm, 2.0%; 320-420 nm, 97.1%) for 20 weeks at a dose of 10.8 J/cm2 five times weekly on weekdays. At the end of 20 weeks irradiation, wrinkling in the dorsal skin was induced. The histological and biochemical studies indicated that UV irradiation caused a disappearance of adipocytes and concomitant accumulation of the extracellular matrix components (fibrosis), including collagen, hyaluronan, and chondroitin/dermatan, which are synthesized by fibroblasts. Application of 1,25(OH)2D3 on the dorsal skin prior to UV irradiation dramatically prevented both the disappearance of adipocytes and the accumulation of extracellular matrix components in the lower dermis, resulting in antiwrinkling. These findings indicate that 1,25(OH)2D3 prevents the UV-induced abnormal differentiation and proliferation of adipocytes and fibroblasts, which arise from a common progenitor, mesenchymal cells.

Prevention of the photodamage in the hairless mouse dorsal skin by kojic acid as an iron chelator

Kojic acid, a fungal metabolic product, has been used as a skin-depigmenting agent in skin care products marketed in Japan. Iron in the skin is known to be involved in wrinkling as a result of chronic photodamage. Kojic acid was expected to have anti-wrinkling activity, since it possesses iron-chelating activity. We now evaluated the anti-wrinkling activity of kojic acid by using hairless mice exposed to chronic solar-simulating ultraviolet (UV) irradiation as model animal. At the end of a 20-week irradiation period, topical application of kojic acid before UV irradiation was observed to dramatically prevent: (1) the wrinkling, (2) hyperplasia of the epidermis, (3) fibrosis of the lower dermis, and (4) the increase of extracellular matrix components in the upper dermis. These findings indicate that kojic acid is a typical agent preventing wrinkling of the skin due to chronic photodamage.

The cytochrome P450ALK multigene family of an n-alkane-assimilating yeast, Yarrowia lipolytica: cloning and characterization of genes coding for new CYP52 family members

Genes encoding cytochromes P450 of the CYP52 family in the n-alkane-assimilating yeast Yarrowia lipolytica have been cloned and analyzed. Degenerate PCR primers which were designed for the conserved amino acid sequences of cytochromes P450ALK of Candida species were used for amplification and isolation of genes encoding P450ALK from a genomic DNA library of Y. lipolytica CX161-1B. Seven new genes (YlALK2-YlALK8) were isolated. Five of the seven YlALK genes were induced by n-alkane under the culture conditions used in this study, whereas their expression was strictly repressed by glycerol but not by glucose, similar to the case of YlALK1, reported previously. Disruption of YlALK2, YlALK3, YlALK4 or YlALK6 did not change the growth of Y. lipolytica on medium containing n-alkanes of various chain lengths. A mutant with disruptions in both YlALK1 and YlALK2 did not grow well on n-hexadecane, whereas one with disruptions in both YlALK1 and YlALK3, which has the same phenotype as the YlALK1 singly disrupted mutant, grew well on n-hexadecane. These results suggest that the presence of multiple P450ALK species is a rather common phenomenon among the n-alkane-assimilating yeasts and that in the n-alkane assimilation of Y. lipolytica, YlALK1 functions to assimilate n-decane and longer molecules, whereas YlALK2 is involved in the assimilation of molecules longer than n-dodecane; other YlALKs are not significantly involved in the assimilation of C10-C16 n-alkanes.

Endoscopic resection for submucosally invasive colorectal cancer: is it feasible?

BACKGROUND

Recent advances in colonoscopy have resulted in an increasing number of endoscopic resections of colorectal neoplasms. However, endoscopic resection of submucosal invasive cancer remains a controversial issue.

METHODS

The subjects for this study were the surgically treated patients with submucosal invasive colorectal cancer. These patients were classified into two groups: those with versus those without preoperative endoscopic resection. Clinicopathologic features and prognosis were compared and analyzed.

RESULTS

Fifty patients underwent surgery for submucosally invasive colorectal cancer. Numbers of patients with and without preoperative endoscopic resection were 22 and 28, respectively. In 36.4% of the patients, endoscopic resections were incomplete. Two patients in whom the preoperative endoscopic resections had revealed a positive cancer margin, had nodal metastasis. One of these patients also developed hepatic metastasis. Endoscopic findings such as diameter and shape were not indicative of either lymphatic or vascular invasion. There were no morbidities or mortalities associated with endoscopic resection or surgery.

CONCLUSIONS

Preoperative endoscopic resection for colorectal submucosal cancer is feasible, provided the resection is complete. The indications for surgical treatment should be determined after pathologic examination.

Appendico-ileo-vesical fistula

Appendico-vesical fistula is a rare condition. In total, 109 cases, most secondary to appendicitis, have been reported in the English-language literature. We report the first case, to our knowledge, of appendico-ileo-vesical fistula secondary to appendiceal diverticulitis. An enterovesical fistula was diagnosed by urine culture, cystoscopy, and computed tomography. The locations of enteric opening sites were demonstrated by barium enema and colonoscopy. Ileocecal resection and fistulectomy with primary reconstruction were performed. We believe that accurate pre- and intra-operative diagnosis is essential for cure. This case demonstrates the importance of barium enema and colonoscopic examinations in the diagnosis and treatment of complicated enterovesical fistula.

Reactive lymphoid hyperplasia of the liver characterized by an angiofollicular pattern mimicking Castleman's disease

A case of reactive lymphoid hyperplasia of the liver exhibiting a characteristic angiofollicular pattern is reported. A hepatic nodular lesion was discovered by abdominal echography during clinical follow-up of abnormal liver function tests. It was diagnosed as hepatocellular carcinoma because of its hypervascularity when observed by angiography, and surgically resected. Grossly, the lesion was well-demarcated and measured 2 cm in diameter. Microscopically, the nodule was composed of lymph follicles with germinal centers, and the hyalinized inter-follicular space contained abundant hyalinized vasculature and plasma cells. The surrounding liver tissue exhibited chronic inflammation with some peculiar angiofollicular structures mimicking Castleman's disease. An immunohistochemical study revealed that the angiofollicular structure had the same characteristics as a lymph follicle with a germinal center, and that the plasma cells proliferating in the inter-follicular space had polyclonal immunophenotypes. These histological and immunohistochemical findings indicated that the angiofollicular structure observed was a kind of reactive lymph follicle, and that this hepatic lesion was reactive lymphoid hyperplasia rather than Castleman's disease or an inflammatory pseudotumor.

[Home days ratio in patients treated with long-term oxygen therapy]

The home days ratio (days at home/observation period) is an important index for evaluating the efficacy of therapy for chronic disease. To compute the home days ratio in patients treated with long-term oxygen therapy, we retrospectively studied the records of 72 consecutive patients with chronic respiratory failure who received long-term oxygen therapy from the Department of Pulmonary Medicine, Ogaki Municipal Hospital. These patients were representative of those treated with long-term oxygen therapy in terms of age, cause of hypoxemia, blood gas values, and pulmonary function. The home days ratio gradually decreased; it was 92.7 +/- 15.2% during the first year, 87.5 +/- 24.0% during the second year, and 78.5 +/- 39.7% during the third year. The home days ratios in survivors (n = 39) were greater than in non-survivors (n = 33). For the first year: 96.7 +/- 7.5% vs. 85.8 +/- 21.9%, p = 0.034; for the second year: 99.0 +/- 2.6% vs. 71.4 +/- 31.0%, p = 0.004; for the third year: 96.0 +/- 9.0% vs. 48.4 +/- 53.1%, p = 0.081, for survivors and non-survivors, respectively. These data suggest that non-survivors can be distinguished from survivors soon after the start of oxygen therapy.

Effects of roxithromycin on proliferation of peripheral blood mononuclear cells and production of lipopolysaccharide-induced cytokines

Roxithromycin (RXM), a new macrolide antibiotic, has a 14-member macrocycline ring structure which is similar to that of erythromycin. We investigated the effects of RXM on the proliferation of peripheral blood mononuclear cells (PBMCs) and the production of interleukin 1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF-alpha) by PBMCs stimulated with lipopolysaccharide (LPS). At concentrations greater than 25.0 micrograms/ml, RXM suppressed the proliferation of PBMCs stimulated with phytohemagglutinin, probably due to cytotoxicity. When the PBMCs were incubated with RXM for 7 d, the number of adherent cells (monocyte/macrophages) increased. Incubation with RXM at a concentration of 25.0 micrograms/ml induced the greatest increase (p < 0.05). IL-1 beta and TNF-alpha were present 3 h after LPS-stimulation, and IL-1 beta production reached a peak at 12 h and TNF-alpha production at between 6 and 12 h, and then their production declined. RXM (25 micrograms/ml) suppressed the production of IL-1 beta and TNF-alpha slightly during the entire course of the incubation. This suppression was dose-dependent. Anti-human granulocyte-macrophage colony-stimulating factor and anti-human macrophage colony stimulating factor antibodies had no effect on the RXM-induced proliferation of adherent cells. Suppression of the production of IL-1 beta and TNF-alpha by RXM suggested that this drug might have anti-inflammatory and immunosuppressive effects.

Effects of a new nitro compound on the systemic circulatory system in dogs

The present study was undertaken to evaluate the effects of a newly synthesized nitro compound (E-4701) on the systemic circulatory system with special reference to venous return and vascular compliance. Dogs were anesthetized with sodium pentobarbital. After opening the chest, cannulae were inserted into the superior and inferior vena cavae and into the right atrial appendage. The venous flow from the caval veins was redirected to a blood reservoir with an outlet at a constant height. The blood was pumped into the right atrium at a constant flow rate. E-4701 had a hypotensive effect, and also caused a decrease in reservoir blood volume; i.e., a decrease in venous return. Venous return via the superior vena cava was increased, whereas return via the inferior vena cava was decreased. Similar effects on the systemic circulatory system were observed with nitroprusside. The lowest dose of nitroprusside that caused a significant reduction in blood pressure was the same dose as that which caused a decrease in reservoir blood volume. However, a low dose of E-4701 caused a significant reduction in reservoir blood volume without affecting the systemic blood pressure. Arterial and venous compliances were increased by both E-4701 and nitroprusside. Nitroglycerin and isosorbide dinitrate increased venous compliance, but did not affect arterial compliance. The results suggest that E-4701 caused an almost equipotent reduction in blood pressure and venous return by dilating the arterial and venous vascular beds. The capacitance vessels may be more sensitive to E-4701 than the resistance vessels.

Capsaicin-sensitive nerves exert an inhibitory effect on the development of fibrin-induced pulmonary edema in rats

This study was undertaken to evaluate the role of vagal nerves in the development of neurogenic pulmonary edema. We injected fibrinogen and thrombin into the cisterna magna of rats, a model of neurogenic pulmonary edema. When the vagal nerves were left intact, pulmonary edema occurred (fibrin-induced pulmonary edema) at a rate of 33%. Vagotomy at the midcervical portion increased the incidence of pulmonary edema to a rate of 100%, whereas pretreatment with atropine did not affect the incidence. These results suggested that vagal afferent nerves or nonadrenergic-noncholinergic efferent nerves played an important role in inhibiting the development of fibrin-induced pulmonary edema. Furthermore, in vagotomized and vagal nerve-intact rats pretreated with capsaicin, the incidence of pulmonary edema was 100%. Pretreatment with a substance P antagonist, [D-Pro2, D-Trp7,9]-SP, also increased the incidence to 100% in the vagal nerve-intact rats. On the other hand, intravenous administration of some neuropeptides that may be released from the capsaicin-sensitive nerves (e.g., substance P or calcitonin gene-related peptide) inhibited the development of pulmonary edema in vagotomized rats. We concluded that the vagal capsaicin-sensitive nerves exerted an inhibitory effect on the development of fibrin-induced pulmonary edema.

5-Hydroxytryptamine receptor subtypes participating in pulmonary edema in dogs

The present study was undertaken to evaluate the effects of 5-hydroxytryptamine on pulmonary vascular resistances and vascular permeability with respect to the 5-hydroxytryptamine receptor subtypes. Left lower lobe of lungs isolated from the dog was perfused with constant heights of arterial and venous blood reservoirs and was maintained at zone III condition (pulmonary venous pressure greater than airway pressure). Drugs were administered into blood reservoir (1 l of total blood volume). Infusion of 5-hydroxytryptamine (100 micrograms/min) increased the pulmonary pre- and post-capillary resistances, but did not change the filtration coefficient. In the presence of ketanserin (10 mg), the infusion of 5-hydroxytryptamine caused an increase in filtration coefficient that was prevented by methysergide (30 mg). ICS 205-930 (10 mg) did not prevent such an increase in filtration coefficient. Infusion of 5-carboxamidotryptamine (100 micrograms/min) increased the filtration coefficient as well as both pre- and post-capillary resistances. These results suggested that the 5-HT1-like receptor mediates the increase in pulmonary vascular permeability.

S1-receptor participation in serotonin-induced pulmonary edema in the dog

A canine lung-perfusion preparation was used to evaluate the role of serotonin receptor subtype in the development of serotonin-induced pulmonary edema. Ketanserin, an S2-receptor antagonist, blocked an increase in pulmonary arterial pressure caused by serotonin, but not the development of pulmonary edema. Methysergide, an S1- and S2-receptor antagonist, prevented the increase in pulmonary arterial pressure and edema formation caused by serotonin. These results suggest that the S1-receptor may participate in the development of pulmonary edema.

C4 nephritic factor in a patient with chronic glomerulonephritis

C4 nephritic factor (C4NeF) was found in the serum of a patient with chronic glomerulonephritis, whose C3 level was quite low (less than 1% of normal). C4NeF prevented the intrinsic decay of C4b2a enzyme and prolonged the half life of the C4b2a from several minutes to more than 1 h in the solid and fluid phase. The C4NeF activity was associated with a protein fraction immunochemically identified as the IgG3 subclass and it bound specifically to the EAC142 cells. In addition, the patient's serum contained C3-cleaving activity, probably C4b2a, C4NeF complex, which may have lowered the level of C3 in the patient's serum. Spontaneously, the titer of C4NeF decreased, while the level of C3 increased.

[An improved mouse metabolism cage and its performance tests (author's transl)]

An improved mouse metabolism cage, remodeled after the conventional makeshift type to permit accurate measurement of urine volume, avoiding or minimizing fecal contamination of urinary constituents and undue stress on the animal under test, is described. The structure of the cage is illustrated in detail in Figures 1 and 2. The principal points of modification include: 1) a semi-level top surface of the glass globe separator to accommodate the mouse in a less stressful posture of reduced instability; 2) a steeper gradient of the lateral spherical surface of the glass globe separator avoid contamination of urine by feces, drinking water leaks and debris of diet, along with a shortened urine collecting tail (27 mm) and a receptacle for water leaks; and 3) an insulator installed at the bottom to prevent escape of the animal. Performance tests of the cage demonstrated accurate measurements of urine output and water intake and assays of urinary constituents, with complete prevention against escape of mice.