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At least 1,099 records · Page 61Linked to original sources
PubMed1977

Potassium hydroxide solution 10% for the fast hydrolysis of esters for analysis.

The applicability of a five-minute hydrolysis method with 10% potassium hydroxide in an alcohol-water (80-20) mixture was investigated for the quantitative determination of certain esters (aspirin, benzocaine, benzyl benzoate, methyl paraben, phenyl salicylate, procaine hydrochloride, propyl paraben, salicylanilide and 0-salicylsalicylic acid) and salicylamide. The results indicate that the method is satisfactory for all but methyl paraben and propyl paraben.

Benzocaine↗
PubMedDate not supplied

Success of electrofulguration pulpotomies covered by zinc oxide and eugenol or calcium hydroxide: a clinical study.

Electrofulguration pulpotomies were completed on 47 primary molars in 38 patients, aged 3 years 1 month to 8 years 1 month. Following electrofulguration, teeth were assigned randomly to one of two groups. In group 1, a zinc oxide and eugenol (ZOE) base was placed over the pulpal stumps and, in group 2, a calcium hydroxide (Ca(OH)2) base was placed. Teeth were evaluated clinically and radiographically after 1, 3, and 6 months by two independent examiners. After 6 months, the clinical success of the ZOE and Ca(OH)2 groups was 77.39 and 81.0%, respectively. Radiographically, after 6 months, the ZOE group had a success rate of 54.6% and the Ca(OH)2 group, 57.3%. There were no statistical differences between the two groups, either clinically or radiographically.

Calcium Hydroxide↗
PubMed1995

Calcium hydroxide as an interim treatment dressing.

A case involving the demineralization of osseous matrix surrounding an intact, necrotic lateral incisor undergoing orthodontic therapy is presented. The treatment involved calcium hydroxide as an interim treatment dressing in conjunction with endodontic therapy. Mechanisms involved in repair are discussed.

Adolescent↗
PubMed1997

Adsorption to aluminum hydroxide promotes the activity of IL-12 as an adjuvant for antibody as well as type 1 cytokine responses to HIV-1 gp120.

A series of protocols were tested to examine the adjuvant effects of IL-12 on humoral and type 1 cytokine responses elicited in mice by recombinant gp120 envelope protein from HIV-1. This Ag fails to induce detectable Ab responses when administered s.c. alone, but stimulates low Ab levels when combined with aluminum hydroxide (alum). Moreover, when i.p. injected rIL-12 was included in the immunization, no increase in Ab production was observed. Importantly, optimal gp120 Ab responses were achieved by immunizing mice s.c. with gp120 and rIL-12 simultaneously coadsorbed to alum. These animals displayed a highly polarized, type 1 cytokine profile, with the emergence of anti-gp120 Ig belonging to the IgG2 and IgG3 isotypes. In addition, a major increase occurred in Ab of the IgG1 subclass. The superior adjuvant activity of alum-adsorbed IL-12 compared with that of the free cytokine correlated with the prolonged detection of IFN-gamma in the sera of animals immunized using the former procedure. In related experiments, in vitro neutralization of IL-12 was shown to inhibit IFN-gamma production by spleen cells from mice immunized with gp120 plus alum, but not by splenocytes from mice primed in the presence of IL-12, suggesting that the latter protocol induces a stable type 1 phenotype. These studies demonstrate that presentation of IL-12 on alum enhances its immunomodulatory effects and establish a protocol for the use of the cytokine as an adjuvant for simultaneously promoting both humoral Ab and type 1 cytokine responses.

AIDS Vaccines↗
PubMed1997

Chemical analysis of the formation of calcium carbonate and its influence on calcium hydroxide pastes in connective tissue of the dog--Part II.

The objective of this research was to chemically analyze calcium hydroxide pastes added to three hydrosoluble vehicles having different acid-base characteristics by implanting polyethylene tubes in subcutaneous connective tissue in dogs, evaluating the formation of calcium carbonate over a period of 7, 30, 45, and 60 days. The three vehicles were saline, anesthetic, and polyethylene glycol 400. Determination of the formation of calcium carbonate was evaluated by volumetry of neutralization using hydrochloric acid for titration.

Animals↗
PubMed1998

[Growth and metabolism of calcium in rats chronically poisoned with aluminium hydroxide].

The effects of aluminum on growth have been studied in rats chronically poisoned with aluminum hydroxide (80 mg/kg b.w.-i.p.-three times a week, during 6 months) and in control rats, between 3 and 26 weeks of age. The growth data was evaluated according to Parks 'theory of feeding an growth. At the end of the poisoning period, the calcium metabolism was studied through a balance of calcium and the determination of bone Ca++ accretion and resorption rates with the aid of 45Ca++. The parathyroid glands function was studied using an indirect method. Treated rats showed a significant decrease in asymptotic weights and in the initial efficiency of food conversion into biomass regarding controls. No differences were observed in food intake between both group. Aluminum affected neither the peak growth rate nor the time necessary to attain maturity. The calcium balance in treated rats was significantly less than in the control group. This was accompanied by a significant increase in the calcium excreted by faces, caused perhaps by a less intestinal absorption. An important amount of aluminum on the surface of the trabecular bone and a reduction in the skeletal Ca++ mass, was observed in all treated rats. Nevertheless there are no differences in the latter when expressed for 100 g of body weight. The rate of skeletal Ca++ accretion was found to be significantly decreased in treated group with respect to controls, without any changes in the bone Ca resorption rate. The reduction in bone turnover revealed by the decrease of Vo+/Vo- was accompanied by less recovery velocity of calcemia in the aluminum treated group, being indirectly related to the parathyroid gland response to calcium depletion. In the model that we studied the decreased bone turnover could have been caused by deposits of aluminum in bone; however there could exist associated factors such as dysfunction in the secretion of PTH, or less affinity between its receptors at the bone level.

Aluminum Hydroxide↗
PubMed1998

Early diagnosis of mycotic keratitis: predictive value of potassium hydroxide preparation.

Potassium hydroxide (KOH) preparation is an underutilized modality in the diagnosis of mycotic keratitis. We have earlier shown its utility in the diagnosis of Nocardia and Acanthamoeba keratitis. The aim of this study was (i) to evaluate the sensitivity, specificity and predictive value of KOH preparation, and (ii) to compare its efficacy with other methods of corneal scraping examination, for the diagnosis of mycotic keratitis. The study was conducted in two phases. In phase I, randomized corneal scrapings were examined by KOH, Gram's stain, and lactophenol cotton blue (LPCB) in 91 infectious keratitis subjects. In phase II, 53 corneal scrapings were stained with KOH and calcofluor white (CFW), and viewed with bright field (KOH) and fluorescence (CFW) microscopy. The KOH and CFW readings were recorded by an observer masked to the clinical findings and culture results. Nineteen scrapings were examined by two masked observers. In 22 culture positive fungal keratitis patients in phase I, the sensitivity of KOH, Gram's stain, and LPCB methods was 100%, 86.4%, and 77.3%, respectively. In phase II, the specificities of KOH and CFW were identical (83.8%), while the sensitivities were 81.2% and 93.7%, respectively (p = 0.59), in 16 culture positive mycotic keratitis patients. There was no significant difference between the negative and positive predictive values of KOH and CFW. Furthermore, no significant interobserver variability was found in the specificity and sensitivity. The KOH method compares well with other microscopy methods in the diagnosis of keratomycosis and has a definite place in the armamentarium of diagnostic techniques.

Benzenesulfonates↗
PubMed2001

Kinetic and spectroscopic study of 1O2 generation from H2O2 catalyzed by LDH-MoO4(2-) (LDH=layered double hydroxide).

Layered double hydroxides (LDHs), exchanged with molybdate, decompose H2O2 to form one molecule of singlet-state dioxygen (1O2) from two molecules of H2O2. The dependence of the kinetics of H2O2 decomposition on Mo and H2O2 concentrations and on temperature has been related to structural characteristics of the material (X-ray diffraction (XRD), scanning electron microscopy (SEM), IR spectroscopy, N2 adsorption, thermogravimetry) and to molybdate speciation as revealed by in-situ studies in the presence of peroxide (FT Raman, diffuse reflectance UV/visible spectroscopy). The H2O2 decomposition rate is linearly correlated with the amount of LDH-exchanged molybdate, except when a considerable fraction of the molybdate occupies less accessible interlayer positions. A maximum in the H2O2 decomposition rate as the H2O2 concentration is increased is due to the successive formation of mono-, di-, tri-, and tetraperoxomolybdates. This behavior was modeled successfully by using the equilibrium constants for formation of the Mo-peroxo complexes, and the rate constants for decay of the peroxomolybdates with 1O2 liberation. Time-resolved diffuse reflectance and Raman observations of the various MoO4(2-)-peroxide adducts are in line with the proposed kinetic scheme. Of all the Mo-peroxo species on the LDH, the triperoxomolybdate has the highest rate for decay to 1O2. Comparison with the kinetics of dissolved molybdate shows that the monomolecular decay of all peroxomolybdate species proceeds much faster at the LDH surface than in solution. Consequently, maximal rates per Mo atom are at least twice as high for the heterogeneous LDH catalyst as for the homogeneous systems.

Journal Article↗
PubMedDate not supplied

Experimental radiation synovectomy by 165Dy ferric hydroxide macroaggregate.

The short half-life beta emitter 165Dy coprecipitated as a macroaggregate with ferric hydroxide (FHMA) has been shown to destroy knee synovium in the antigen-induced arthritic rabbit. Using 153Gd as a gamma tracer for leakage studies revealed that the leakage of this system from rabbit knee joints never exceeded 1.2% over 24 hours. This is such less than the leakage rates reported from any human studies or our rabbit studies using 198Au.

Animals↗
PubMed1988

Repeat radiation synovectomy with dysprosium 165-ferric hydroxide macroaggregates in rheumatoid knees unresponsive to initial injection.

Because of failure to fully respond to an initial intraarticular injection of dysprosium 165-ferric hydroxide macroaggregates, 17 patients with seropositive rheumatoid arthritis underwent repeat radiation synovectomy using this agent. Of the 13 patients who were evaluated 1 year later, 54% (7 knees) had good results, 31% (4 knees) had fair results, and 15% (2 knees) had poor results. The initial lack of significant benefit from radiation synovectomy did not appear to preclude a favorable response to a second injection.

Adult↗
PubMed1978

The on column methylation of clonidine and p-hydroxyclonidine with trimethylanilinium hydroxide.

The structures of the methylated clonidine derivatives formed by on column methylation with trimethylanilinium hydroxide are revised. The almost exclusive formation of derivatives of phenylimino-N,N-dimethylimidazolidine structure is explained in terms of a fast kinetically controlled reaction of substrate anions. The reliability of a stable isotope dilution assay for clonidine is discussed in view of these results.

Aniline Compounds↗
PubMed1987

Inhibition of beta-adrenergic stimulated calcium pump of rat cardiac sarcoplasmic reticulum by tricyclohexyltin hydroxide.

The effects of tricyclohexyltin hydroxide (Plictran), an organotin acaricide, on 45Ca2+ uptake and Ca2+ ATPase were studied in vitro and in vivo in rat heart ventricular membrane vesicles, primarily sarcoplasmic reticulum. There was a concentration dependent inhibition of both 45Ca2+ uptake and Ca2+ ATPase in vivo as well as in vitro. Isoproterenol, a beta-adrenergic agonist, stimulated 45Ca2+ uptake and Ca2+ ATPase of sarcoplasmic reticulum and this was also inhibited by Plictran. Since cardiac relaxation is mediated by beta-adrenergic stimulation via Ca+ uptake by sarcoplasmic reticulum, the inhibition of calcium pump activity by Plictran may result in alterations in cardiac Ca2+ fluxes leading to cardiac dysfunction.

Animals↗
PubMed2006

Lithium hydroxide phase transition under high pressure: an ab initio molecular dynamics study.

The high-pressure phase transition in the deuterated lithium hydroxide crystalline state has been studied by Car-Parrinello molecular dynamics simulations, in the constant-pressure, constant-temperature ensemble. The recently developed metadynamics approach has been applied to encourage the system to transform into different phases in an affordable simulation time. A previously not completely characterized high-pressure phase has been obtained. The structural and spectroscopic properties have been studied and compared with the neutron scattering, infrared and Raman measurements. It has been found that the calculated structure differs slightly from the experimental hypothesis, and that the presence of strong hydrogen bonds is the source of the red shift and of the characteristic features of the OD-stretching bands in both IR and Raman spectra.

Journal Article↗
PubMed1986

Tricyclohexyltin hydroxide effects on cationic and substrate activation kinetics of beta-adrenergic-stimulated cardiac Ca2+-ATPase.

Previous studies from this laboratory have indicated that tricyclohexyltin hydroxide (Plictran) is a potent inhibitor of both basal- and isoproterenol-stimulated cardiac sarcoplasmic reticulum (SR) Ca2+-ATPase, with an estimated IC-50 of 2.5 X 10(-8) M. The present studies were initiated to evaluate the mechanism of inhibition of Ca2+-ATPase by Plictran. Data on substrate and cationic activation kinetics of Ca2+-ATPase indicated alteration of Vmax and Km by Plictran (1 and 5 X 10(-8) M), suggesting a mixed type of inhibition. The beta-adrenergic agonist isoproterenol increased Vmax of both ATP- and Ca2+-dependent enzyme activities. However, the Km of enzyme was decreased only for Ca2+. Plictran inhibited isoproterenol-stimulated Ca2+-ATPase activity by altering both Vmax and Km of ATP as well as Ca2+-dependent enzyme activities, suggesting that after binding to a single independent site, Plictran inhibits enzyme catalysis by decreasing the affinity of enzyme for ATP as well as for Ca2+. Preincubation of enzyme with 15 microM cAMP or the addition of 2mM ATP to the reaction mixture resulted in slight activation of Plictran-inhibited enzyme. Pretreatment of SR with 5 X 10(-7) M propranolol and 5 X 10(-8) M Plictran resulted in inhibition of basal activity in addition to the loss of stimulated activity. Preincubation of heart SR preparation with 5 X 10(-5) M coenzyme A in combination with 5 X 10(-8) M Plictran partly restored the beta-adrenergic stimulation. These results suggest that some critical sites common to both basal- and beta-adrenergic-stimulated Ca2+-ATPase are sensitive to binding by Plictran, and the resultant conformational change may lead to inhibition of beta-adrenergic stimulation.

Adenosine Triphosphate↗
PubMed1977

Colloidal iron hydroxide-binding to the surfaces of chick embryo fibroblasts transformed by wild-type and a temperature-sensitive mutant of Rous sarcoma virus.

The densities of colloidal iron hydroxide (CIH) particles binding to the surfaces of chick embryo fibroblasts were determined before and after transformation with wild type Rous sarcoma virus and a temperature sensitive (ts) mutant of this virus. On the basis of in vitro behavior, cells transformed by the ts virus manifest a malignant phenotype at 36 degrees C (permissive temperature) and appear normal at 41 degrees C (non-permissive temperature). At the permissive temperatures there is a significant increase in CIH particle-binding to spaces of cell surface between microvilli on the wild type and ts transformed cells. At the non-permissive temperature this significant increase in binding is only observed on the wild type transformant, while the density found on the ts transformant is not significantly different from the untransformed state. Therefore, in vitro characteristics of normalcy and malignancy are reflected in changes in the CIH binding properties of the cell surface spaces between microvilli. The CIH densities observed on the microvilli are significantly different from the density on the spaces between them for each of the classes of cells studied at either temperature. The microvilli are found to bind a lower density of particles in five of the six cases. No correlations between microvilli particle density and transformation to in vitro malignant characteristics were observed.

Animals↗
PubMed2007

Static SIMS studies of the oxides and hydroxides of aluminium.

The degree of hydroxylation or hydration of aluminium surfaces has been examined by static secondary ion mass spectroscopy (SSIMS). The SSIMS spectra of a series of aluminium oxide, oxyhydroxide and hydroxide surfaces have been obtained using instruments in three configurations. Similarities were observed in both negative and positive secondary ions spectra. Even though a direct comparison of the relative intensities cannot be made from one instrument to the other, a similar ranking of the various aluminium hydroxylation states was observed. Several ranking methods are discussed, as well as the similarities and differences observed while using the three instruments. Similar secondary ions were detected whatever the degree of hydroxylation of the aluminium oxide. This argues in favour of the formation of fragments by the combination of individually sputtered atoms or clusters to form the more stable secondaries, rather than the kick-off of 'structure-related' clusters originating directly from the upper surface layer.

Journal Article↗
PubMed1989

Treatment of antigen-induced arthritis in rabbits with dysprosium-165-ferric hydroxide macroaggregates.

Dysprosium-165-ferric hydroxide macroaggregates (165Dy-FHMA) was used as an agent of radiation synovectomy in an antigen-induced arthritis model in New Zealand white rabbits. Animals were killed up to 6 months after treatment. 165Dy-FHMA was found to have a potent but temporary antiinflammatory effect on synovium for up to 3 months after treatment. Treated knees also showed significant preservation of articular cartilage architecture and proteoglycan content compared with untreated controls, but only during the first 3 months after treatment. In animals killed 3 and 6 months after treatment there were only minimal differences between the treated and untreated knees, indicating that the antiinflammatory effects on synovial tissue and articular cartilage preservation were not sustained.

Animals↗