The effect of O-Carboxyphenyl-β-D-Gluco-pyranosiduronic acid upon the water dissolution of chemical compounds in urinary calculi

Thesis (M.A.)--Boston UniversityPrien and Walker^39 have treated chronic kidney stone formers with aspirin. They obtained clinical evidence showing no new stone growth and inhibition of the growth of existing stones. The rationale behind such therapy is that aspirin is excreted as a glucuronide conjugate in the urine, and the glucuronide increases dissolution of calcium phosphate stones. Previous laboratory studies^39,10 have shown glucuronides (a concentrate of mixed urinary glucuronides, or o-aminophenol glucuronide) to increase the dissolution of tricalcium phosphate. Tricalcium phosphate is neither a major nor even common component of urinary calculi. The purpose of this investigation is to demonstrate the effect of a glucuronide of salicylates on the dissolution of urinary calculi and their major component compounds. The diffuse pharmacological action of salicylates makes critical, in vitro experiments imperative. The ether glucuronide conjugate of salicylic acid, o-carboxyphenyl-β-D-glucopyranosiduronic acid (o-CPG), a known metabolic product of salicylates found in urine^40 and stones of known composition or synthetic components of stones should be used in these experiments. In the course of this investigation evidence of increased dissolution warranted further experimentation into the possible cause of such effects. Aspirin therapy as initiated by Prien and Walker derived from the qualitative experiments of Neuberg, Mandl and Grauer^33,29,30. In these experiments the authors attempted to either dissolve calcium salts or to inhibit their precipitation by addition of naturally occurring organic and inorganic acids. They showed that 1-menthol-Dglucuronic acid solubilizes both calcium carbonate and calcium phosphate salts, that it functions in this way much better than non conjugated glucuronic acid and that incubation of such a mixture with β-glucuronidase leads to precipitation of the salt. The work of Cessi^10 followed in which the solubilizing effect of a glucuronide was observed during the synthesis of the glucuronide by an in vitro biological system. p^32 in the supernatant fluid resulting from dissolution of a solid phase of tricalcium phosphate containing p^32 (placed in the flask with the liver slices) was measured by counting the activity. The increase of p^32 over a control flask was found to vary directly with the glucuronide concentration. Salicylates have been shown to be excreted as the phenolic glucuronide ^40,25,2. Smith^42 has shown that acetylsalicylic acid is probably hydrolyzed in plasma to form salicylic acid. An increase of urinary glucuronides could then be made to occur by the ingestion of various "glucurongenins" (Teague). Prien and Walker^39 have reported an increase of 200 - 400 per cent over the basal level of urinary glucuronides in man during a 2 gm dose of aspirin / day. Glucuronides are manufactured largely by the liver, kidney and mucosa of the alimentary tract^15,23,24. The biosynthesis requires a coenzyme, uridine diphosphate which is thought to react with glucose to produce uridine diphosphoglucose which then may be oxidized to uridine diphosphoglucuronic acid in the presence of DPN^+45. The uridine diphosphoglucuronic acid will then transfer the glucuronic acid to a proper acceptor such as a phenol. The role of ingested glucuronic acid in this metabolic scheme seems to be negligible. Only a small percentage is recovered in the urine^20. Douglas and King using labeled glucurone found the glucuronic acid in the urine to be labeled in such a way as to support the theory that the glucurone breaks to three-carbon fragments. These fragments probably form a six-carbon precursor of glucuronic acid. Urinary tract calculi have been shown by Prien^37 to contain calcium in 90 per cent of 1000 calculi studied. Thirty-three per cent were pure calcium oxalate, 3.4 per cent pure hydroxy apatite and 34 per cent were mixtures of calcium oxalate and hydroxy apatite. Hydroxy apatite is considered to be the main inorganic component of animal bone. The chemical structure of a unit cell is Ca10(PO4)6(OH)2^34,9,4. This crystal is the most common phosphate crystal found in urinary calculi. It is this component of urinary calculi with which this investigation is mainly concerned. EXPERIMENTAL The first series of experiments were designed to find the effect of o-CPG on the dissolution of a urinary tract stone composed chiefly of hydroxy apatite. The degree of dissolution was followed with phosphate determinations, using the colorometric procedure of Fiske and Subbarow.^21 Since uric acid, salicylic acid, salicyluric acid and o-CPG are all found in the urine in increased amounts following ingestion of salicylates, these compounds were examined for their dissolutive effect. The test flask contained 100 mg of a powdered urinary stone composed mainly of hydroxy apatite, and 0.1 mMoles of the test compound. The mixture was placed in a small dialysis bag along with 4-5 glass beads and 10 ml of buffer. This bag was placed in a 50 ml Erlenmeyer flask containing 30 ml of the buffer and a few glass beads. Several drops of toluene were added to prevent bacterial contamination. The buffer used was Michaelis universal veronal buffer, pH 7.8. This pH was chosen because Prien and Walker^39 had found it to be optimal for dissolution of calcium phosphate in their early experiments. The o-CPG was synthesized in this laboratory using the method of Lunsford and Murphey.^28 The flasks were placed in a shaking water bath at 38°C. and aliquots of the external phase in the flasks were analysed at 5 hours and 10 hours. Duplicate flasks were set up for each substance in question and for the control flask which contained hydroxy apatite only. At the end of 5 hours the o-CPG flask showed an increase in the phosphate concentration of 85 per cent over the control. The other substances showed little or no increase. After 10 hours the o-CPG showed an increase of 36 per cent over the control. We conclude that o-CPG increases the dissolution of urinary tract calculi composed mainly of hydroxy apatite. Furthermore, it is suggested from the decreasing per cent of increased dissolution over time that the o-CPG also hastens the equilibrium of dissolution. The experiment was repeated substituting synthetic hydroxy apatite, prepared in this laboratory, for the powdered stone. Estradiol glucuronide was examined as well as o-CPG. After 5.75 hours both glucuronides increased dissolution; the estradiol glucuronide increased the dissolution by 87 per cent and in this case the o-CPG produced a 555 per cent increase. It can be concluded that o-CPG increases dissolution of hydroxy apatite and that it works better on pure hydroxy apatite than on other forms of calcium and phosphate. Other investigators^39,10 have found an increase of about 40 per cent using calcium phosphate. The first possible explanation for these results, which occurred to us was that o-CPG was complexing calcium ion. In order to determine if complex formation with calcium were taking place, conductometric titrations were performed. The titration curves of sodium hydroxide and of calcium hydroxide with o-CPG, glucuronolactone and salicylic acid, were compared. If the sodium hydroxide titration fits well to the calcium hydroxide titration curve, one concludes that no highly conductive ions are produced and complex formation is absent. The results showed that there is a possibility that a slight amount of complex formation may have occurred with glucuronolactone but certainly not with salicylic acid or o-CPG. Further proof that no complexing of calcium was taking place was obtained by measuring conductivity of separate solutions of calcium lactate and o-CPG at different concentrations. They were then combined, each at one half their original concentration and the resultant conductivity compared with the theoretical conductivity which we calculated. Results show that the combined conductivity is about the same as the theoretical and therefore complex formation is absent. This type of experiment was repeated using calcium chloride instead of calcium lactate and the same results were obtained. The only conclusion we can draw is that o-CPG does not complex calcium. It was thought that perhaps o-CPG complexes calcium and phosphate together. To test this hypothesis another dissolution experiment was designed similar to the first ones reported. However, the o-CPG was incubated in one case with phosphate and in another case with barium and phosphate before being added to the synthetic hydroxy apatite. The only test flask which showed a significant difference from the controls was that one in which o-CPG was incubated first with barium and phosphate. Here, the dissolution effect of o-CPG was decreased by 30 per cent. We conclude that calcium and phosphate may be complexed together by o-CPG. In summary we may state that o-CPG increases the dissolution of urinary tract calculi containing hydroxy apatite; it increases the dissolution of synthetic hydroxy apatite; it does not form a complex with calcium but it may form a complex with calcium and phosphate. The results also suggest that it may increase the dissolution of hydroxy apatite by acting at the surface of the crystal. This question requires further investigation

The effect of O-Carboxyphenyl-β-D-Gluco-pyranosiduronic acid upon the water dissolution of chemical compounds in urinary calculi

Thesis (M.A.)--Boston UniversityPrien and Walker^39 have treated chronic kidney stone formers with aspirin. They obtained clinical evidence showing no new stone growth and inhibition of the growth of existing stones. The rationale behind such therapy is that aspirin is excreted as a glucuronide conjugate in the urine, and the glucuronide increases dissolution of calcium phosphate stones. Previous laboratory studies^39,10 have shown glucuronides (a concentrate of mixed urinary glucuronides, or o-aminophenol glucuronide) to increase the dissolution of tricalcium phosphate. Tricalcium phosphate is neither a major nor even common component of urinary calculi. The purpose of this investigation is to demonstrate the effect of a glucuronide of salicylates on the dissolution of urinary calculi and their major component compounds. The diffuse pharmacological action of salicylates makes critical, in vitro experiments imperative. The ether glucuronide conjugate of salicylic acid, o-carboxyphenyl-β-D-glucopyranosiduronic acid (o-CPG), a known metabolic product of salicylates found in urine^40 and stones of known composition or synthetic components of stones should be used in these experiments. In the course of this investigation evidence of increased dissolution warranted further experimentation into the possible cause of such effects. Aspirin therapy as initiated by Prien and Walker derived from the qualitative experiments of Neuberg, Mandl and Grauer^33,29,30. In these experiments the authors attempted to either dissolve calcium salts or to inhibit their precipitation by addition of naturally occurring organic and inorganic acids. They showed that 1-menthol-Dglucuronic acid solubilizes both calcium carbonate and calcium phosphate salts, that it functions in this way much better than non conjugated glucuronic acid and that incubation of such a mixture with β-glucuronidase leads to precipitation of the salt. The work of Cessi^10 followed in which the solubilizing effect of a glucuronide was observed during the synthesis of the glucuronide by an in vitro biological system. p^32 in the supernatant fluid resulting from dissolution of a solid phase of tricalcium phosphate containing p^32 (placed in the flask with the liver slices) was measured by counting the activity. The increase of p^32 over a control flask was found to vary directly with the glucuronide concentration. Salicylates have been shown to be excreted as the phenolic glucuronide ^40,25,2. Smith^42 has shown that acetylsalicylic acid is probably hydrolyzed in plasma to form salicylic acid. An increase of urinary glucuronides could then be made to occur by the ingestion of various "glucurongenins" (Teague). Prien and Walker^39 have reported an increase of 200 - 400 per cent over the basal level of urinary glucuronides in man during a 2 gm dose of aspirin / day. Glucuronides are manufactured largely by the liver, kidney and mucosa of the alimentary tract^15,23,24. The biosynthesis requires a coenzyme, uridine diphosphate which is thought to react with glucose to produce uridine diphosphoglucose which then may be oxidized to uridine diphosphoglucuronic acid in the presence of DPN^+45. The uridine diphosphoglucuronic acid will then transfer the glucuronic acid to a proper acceptor such as a phenol. The role of ingested glucuronic acid in this metabolic scheme seems to be negligible. Only a small percentage is recovered in the urine^20. Douglas and King using labeled glucurone found the glucuronic acid in the urine to be labeled in such a way as to support the theory that the glucurone breaks to three-carbon fragments. These fragments probably form a six-carbon precursor of glucuronic acid. Urinary tract calculi have been shown by Prien^37 to contain calcium in 90 per cent of 1000 calculi studied. Thirty-three per cent were pure calcium oxalate, 3.4 per cent pure hydroxy apatite and 34 per cent were mixtures of calcium oxalate and hydroxy apatite. Hydroxy apatite is considered to be the main inorganic component of animal bone. The chemical structure of a unit cell is Ca10(PO4)6(OH)2^34,9,4. This crystal is the most common phosphate crystal found in urinary calculi. It is this component of urinary calculi with which this investigation is mainly concerned. EXPERIMENTAL The first series of experiments were designed to find the effect of o-CPG on the dissolution of a urinary tract stone composed chiefly of hydroxy apatite. The degree of dissolution was followed with phosphate determinations, using the colorometric procedure of Fiske and Subbarow.^21 Since uric acid, salicylic acid, salicyluric acid and o-CPG are all found in the urine in increased amounts following ingestion of salicylates, these compounds were examined for their dissolutive effect. The test flask contained 100 mg of a powdered urinary stone composed mainly of hydroxy apatite, and 0.1 mMoles of the test compound. The mixture was placed in a small dialysis bag along with 4-5 glass beads and 10 ml of buffer. This bag was placed in a 50 ml Erlenmeyer flask containing 30 ml of the buffer and a few glass beads. Several drops of toluene were added to prevent bacterial contamination. The buffer used was Michaelis universal veronal buffer, pH 7.8. This pH was chosen because Prien and Walker^39 had found it to be optimal for dissolution of calcium phosphate in their early experiments. The o-CPG was synthesized in this laboratory using the method of Lunsford and Murphey.^28 The flasks were placed in a shaking water bath at 38°C. and aliquots of the external phase in the flasks were analysed at 5 hours and 10 hours. Duplicate flasks were set up for each substance in question and for the control flask which contained hydroxy apatite only. At the end of 5 hours the o-CPG flask showed an increase in the phosphate concentration of 85 per cent over the control. The other substances showed little or no increase. After 10 hours the o-CPG showed an increase of 36 per cent over the control. We conclude that o-CPG increases the dissolution of urinary tract calculi composed mainly of hydroxy apatite. Furthermore, it is suggested from the decreasing per cent of increased dissolution over time that the o-CPG also hastens the equilibrium of dissolution. The experiment was repeated substituting synthetic hydroxy apatite, prepared in this laboratory, for the powdered stone. Estradiol glucuronide was examined as well as o-CPG. After 5.75 hours both glucuronides increased dissolution; the estradiol glucuronide increased the dissolution by 87 per cent and in this case the o-CPG produced a 555 per cent increase. It can be concluded that o-CPG increases dissolution of hydroxy apatite and that it works better on pure hydroxy apatite than on other forms of calcium and phosphate. Other investigators^39,10 have found an increase of about 40 per cent using calcium phosphate. The first possible explanation for these results, which occurred to us was that o-CPG was complexing calcium ion. In order to determine if complex formation with calcium were taking place, conductometric titrations were performed. The titration curves of sodium hydroxide and of calcium hydroxide with o-CPG, glucuronolactone and salicylic acid, were compared. If the sodium hydroxide titration fits well to the calcium hydroxide titration curve, one concludes that no highly conductive ions are produced and complex formation is absent. The results showed that there is a possibility that a slight amount of complex formation may have occurred with glucuronolactone but certainly not with salicylic acid or o-CPG. Further proof that no complexing of calcium was taking place was obtained by measuring conductivity of separate solutions of calcium lactate and o-CPG at different concentrations. They were then combined, each at one half their original concentration and the resultant conductivity compared with the theoretical conductivity which we calculated. Results show that the combined conductivity is about the same as the theoretical and therefore complex formation is absent. This type of experiment was repeated using calcium chloride instead of calcium lactate and the same results were obtained. The only conclusion we can draw is that o-CPG does not complex calcium. It was thought that perhaps o-CPG complexes calcium and phosphate together. To test this hypothesis another dissolution experiment was designed similar to the first ones reported. However, the o-CPG was incubated in one case with phosphate and in another case with barium and phosphate before being added to the synthetic hydroxy apatite. The only test flask which showed a significant difference from the controls was that one in which o-CPG was incubated first with barium and phosphate. Here, the dissolution effect of o-CPG was decreased by 30 per cent. We conclude that calcium and phosphate may be complexed together by o-CPG. In summary we may state that o-CPG increases the dissolution of urinary tract calculi containing hydroxy apatite; it increases the dissolution of synthetic hydroxy apatite; it does not form a complex with calcium but it may form a complex with calcium and phosphate. The results also suggest that it may increase the dissolution of hydroxy apatite by acting at the surface of the crystal. This question requires further investigation

The ILR School at Fifty: Voices of the Faculty, Alumni & Friends (Full Text)

A collection of reflections on the first fifty years of the School of Industrial and Labor Relations at Cornell University. Compiled by Robert B. McKersie, J. Gormly Miller, Robert L. Aronson, and Robert R. Julian. Edited by Elaine Gruenfeld Goldberg. It was the hope of the compilers that the reflections contained in this book would both kindle memories of the school and stimulate interest on the part of future generations of ILRies who have not yet shared in its special history. Dedicated to the Memory of J. Gormly Miller, 1914-1995. Copyright 1996 by Cornell University. All rights reserved

Promoting Community and Population Health in Public Health and Medicine: A Stepwise Guide to Initiating and Conducting Community-engaged Research

Various methods, approaches, and strategies designed to understand and reduce health disparities, increase health equity, and promote community and population health have emerged within public health and medicine. One such approach is community-engaged research. While the literature describing the theory, principles, and rationale underlying community engagement is broad, few models or frameworks exist to guide its implementation. We abstracted, analyzed, and interpreted data from existing project documentation including proposal documents, project-specific logic models, research team and partnership meeting notes, and other materials from 24 funded community-engaged research projects conducted over the past 17 years. We developed a 15-step process designed to guide the community-engaged research process. The process includes steps such as: networking and partnership establishment and expansion; building and maintaining trust; identifying health priorities; conducting background research, prioritizing “what to take on”; building consensus, identifying research goals, and developing research questions; developing a conceptual model; formulating a study design; developing an analysis plan; implementing the study; collecting and analyzing data; reviewing and interpreting results; and disseminating and translating findings broadly through multiple channels. Here, we outline and describe each of these steps

Phase transitions in self-gravitating systems. Self-gravitating fermions and hard spheres models

We discuss the nature of phase transitions in self-gravitating systems both in the microcanonical and in the canonical ensemble. We avoid the divergence of the gravitational potential at short distances by considering the case of self-gravitating fermions and hard spheres models. Three kinds of phase transitions (of zeroth, first and second order) are evidenced. They separate a ``gaseous'' phase with a smoothly varying distribution of matter from a ``condensed'' phase with a core-halo structure. We propose a simple analytical model to describe these phase transitions. We determine the value of energy (in the microcanonical ensemble) and temperature (in the canonical ensemble) at the transition point and we study their dependance with the degeneracy parameter (for fermions) or with the size of the particles (for a hard spheres gas). Scaling laws are obtained analytically in the asymptotic limit of a small short distance cut-off. Our analytical model captures the essential physics of the problem and compares remarkably well with the full numerical solutions.Comment: Submitted to Phys. Rev. E. New material adde

Residential Proximity to Agricultural Pesticide Use and Incidence of Breast Cancer in California, 1988–1997

California is the largest agricultural state in the United States and home to some of the world’s highest breast cancer rates. The objective of our study was to evaluate whether California breast cancer rates were elevated in areas with recent high agricultural pesticide use. We identified population-based invasive breast cancer cases from the California Cancer Registry for 1988–1997. We used California’s pesticide use reporting data to select pesticides for analysis based on use volume, carcinogenic potential, and exposure potential. Using 1990 and 2000 U.S. Census data, we derived age- and race-specific population counts for the time period of interest. We used a geographic information system to aggregate cases, population counts, and pesticide use data for all block groups in the state. To evaluate whether breast cancer rates were related to recent agricultural pesticide use, we computed rate ratios and 95% confidence intervals using Poisson regression models, adjusting for age, race/ethnicity, and neighborhood socioeconomic status and urbanization. This ecologic (aggregative) analysis included 176,302 invasive breast cancer cases and 70,968,598 person-years of observation. The rate ratios did not significantly differ from 1 for any of the selected pesticide categories or individual agents. The results from this study provide no evidence that California women living in areas of recent, high agricultural pesticide use experience higher rates of breast cancer

Front propagation into unstable and metastable states in Smectic C* liquid crystals: linear and nonlinear marginal stability analysis

We discuss the front propagation in ferroelectric chiral smectics (SmC*) subjected to electric and magnetic fields applied parallel to smectic layers. The reversal of the electric field induces the motion of domain walls or fronts that propagate into either an unstable or a metastable state. In both regimes, the front velocity is calculated exactly. Depending on the field, the speed of a front propagating into the unstable state is given either by the so-called linear marginal stability velocity or by the nonlinear marginal stability expression. The cross-over between these two regimes can be tuned by a magnetic field. The influence of initial conditions on the velocity selection problem can also be studied in such experiments. SmC$^*$ therefore offers a unique opportunity to study different aspects of front propagation in an experimental system

Disambiguation of biomedical text using diverse sources of information

Background: Like text in other domains, biomedical documents contain a range of terms with more than one possible meaning. These ambiguities form a significant obstacle to the automatic processing of biomedical texts. Previous approaches to resolving this problem have made use of various sources of information including linguistic features of the context in which the ambiguous term is used and domain-specific resources, such as UMLS. Materials and methods: We compare various sources of information including ones which have been previously used and a novel one: MeSH terms. Evaluation is carried out using a standard test set (the NLM-WSD corpus). Results: The best performance is obtained using a combination of linguistic features and MeSH terms. Performance of our system exceeds previously published results for systems evaluated using the same data set. Conclusion: Disambiguation of biomedical terms benefits from the use of information from a variety of sources. In particular, MeSH terms have proved to be useful and should be used if available

No barrier to emergence of bathyal king crabs on the Antarctic shelf

Cold-water conditions have excluded durophagous (skeleton-breaking) predators from the Antarctic seafloor for millions of years. Rapidly warming seas off the western Antarctic Peninsula could now facilitate their return to the continental shelf, with profound consequences for the endemic fauna. Among the likely first arrivals are king crabs (Lithodidae), which were discovered recently on the adjacent continental slope. During the austral summer of 2010‒2011, we used underwater imagery to survey a slope-dwelling population of the lithodid Paralomis birsteini off Marguerite Bay, western Antarctic Peninsula for environmental or trophic impediments to shoreward expansion. The population density averaged ∼4.5 individuals × 1,000 m(−2) within a depth range of 1,100‒1,500 m (overall observed depth range 841–2,266 m). Images of juveniles, discarded molts, and precopulatory behavior, as well as gravid females in a trapping study, suggested a reproductively viable population on the slope. At the time of the survey, there was no thermal barrier to prevent the lithodids from expanding upward and emerging on the outer shelf (400- to 550-m depth); however, near-surface temperatures remained too cold for them to survive in inner-shelf and coastal environments (<200 m). Ambient salinity, composition of the substrate, and the depth distribution of potential predators likewise indicated no barriers to expansion of lithodids onto the outer shelf. Primary food resources for lithodids—echinoderms and mollusks—were abundant on the upper slope (550–800 m) and outer shelf. As sea temperatures continue to rise, lithodids will likely play an increasingly important role in the trophic structure of subtidal communities closer to shore

Polyantigenic Interferon-γ Responses Are Associated with Protection from TB among HIV-Infected Adults with Childhood BCG Immunization

Surrogate immunologic markers for natural and vaccine-mediated protection against tuberculosis (TB) have not been identified. HIV-infected adults with childhood BCG immunization entering the placebo arm of the DarDar TB vaccine trial in Dar es Salaam, Tanzania, were assessed for interferon gamma (IFN-γ) responses to three mycobacterial antigen preparations--secreted Mycobacterium tuberculosis antigens 85 (Ag85), early secretory antigenic target 6 (ESAT-6) and polyantigenic whole cell lysate (WCL). We investigated the association between the number of detectable IFN-γ responses at baseline and the subsequent risk of HIV-associated TB. During a median follow-up of 3.3 years, 92 (9.4%) of 979 placebo recipients developed TB. The incidence of TB was 14% in subjects with no detectable baseline IFN-γ responses vs. 8% in subjects with response to polyantigenic WCL (P = 0.028). Concomitant responses to secreted antigens were associated with further reduction in the incidence of HIV-associated TB. Overall the percentage of subjects with 0, 1, 2 and 3 baseline IFN-γ responses to mycobacterial preparations who developed HIV-associated TB was 14%, 8%, 7% and 4%, respectively (P = 0.004). In a multivariate Cox regression model, the hazard of developing HIV-associated TB was 46% lower with each increment in the number of detectable baseline IFN-γ responses (P<0.001). Among HIV-infected adults who received BCG in childhood and live in a TB-endemic country, polyantigenic IFN-γ responses are associated with decreased risk of subsequent HIV-associated TB. ClinicalTrials.gov NCT0052195