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Silen, W., T. E. Machen, and J. G. Forte, "Acid-base balance in amphibian gastric mucosa.", The American journal of physiology, vol. 229, issue 3, pp. 721-30, 1975 Sep. Abstract

It has been established that H+ secretion can be maintained in frog stomach in the absence of exogenous CO2 by using a nutrient bathing fluid containing 25 mM H2PO4 (pH approximately equal to 4.5) or by lowering the pH of a nonbuffered nutrient solution to about 3.0-3.6. Exogenous CO2 in the presence of these nutrient solutions uniformly caused a marked decrease in H+ secretion, PD, adn short-circuit current (Isc) and an increase in transmucosal resistance (R). Elevation of nutrient [k+] to 83 mM reduced R significantly but transiently without change in H+ when nutrient pH less than 5.0, whereas R returned to base line and H+ increased when nutrient pH greater than 5.0. Acidification of the nutrient medium in the presence of exogenous CO2 results in inhibition of the secretory pump, probably by decreasing intracellular pH, and also interferes with conductance at the nutrient membrane. Removal of exogenous CO2 from standard bicarbonate nutrient solution reduced by 50% the H+, PD, and Isc without change in R; K+-free nutrient solutions reverse these changes in Isc and PD but not in H+. The dropping PD and rising R induced by K+-free nutrient solutions in 5% CO2 - 95% O2 are returned toward normal by 100% O2. Our findings support an important role for exogenous CO2 in maintaining normal acid-base balance in frog mucosa by acting as an acidifying agent.

Elkhadem, A., S. Mickan, and D. Richards, "Adverse events of surgical extrusion in treatment for crown-root and cervical root fractures: a systematic review of case series/reports.", Dental traumatology : official publication of International Association for Dental Traumatology, vol. 30, issue 1, pp. 1-14, 2014 Feb. Abstract

BACKGROUND: Crown-root and cervical root fractures constitute a restorative challenge due to sub-gingival position of the fracture margin. Surgical tooth extrusion is one of the treatment options. There is uncertainty regarding the prognosis of such treatment modality.

OBJECTIVE: To assess adverse events of surgical tooth extrusion in the treatment for crown-root and cervical root fractures in permanent teeth.

METHODS: PubMed, Embase, and Google Scholar were searched through 15th of June 2012. Search was limited to English and Arabic languages. Reference list of relevant studies were hand-searched. Grey literature was searched using Open Grey. Two review authors independently extracted data, while only one assessed trial quality using 8-point methodological index for non-randomized studies (MINORS) scale. A sensitivity analysis was performed to exclude studies with suspected patients' duplicates.

RESULTS: Eleven case reports and eight case series involving 226 patients with 243 teeth were identified. No randomized controlled trials were found. The mean quality score for all case series was 9 suggesting a fair quality, while that of all case reports was 5 suggesting poor quality. Non-progressive root resorption is the most common finding following surgical extrusion with an event rate of 30% (95% CI 24.6-36.7%). This is followed by low event rates of tooth loss (5%), slight mobility (4.6%), marginal bone loss (3.7%), and progressive root resorption (3.3%). No ankylosis occurred to any extruded tooth, while severe tooth mobility showed negligible overall event rate of 0.4%.

CONCLUSION: The available evidence suggests that surgical tooth extrusion is a valid technique in management of crown-root and cervical root fracture of permanent teeth. Minimal adverse events and good prognosis are expected. Further, surgical extrusion can be considered as a treatment option in teeth suffering sub-gingival decay.

Hendrickson, W. A., and K. B. Ward, "Atomic models for the polypeptide backbones of myohemerythrin and hemerythrin.", Biochemical and biophysical research communications, vol. 66, issue 4, pp. 1349-56, 1975 Oct 27. Abstract
Jallon, J. M., Y. Risler, and M. Iwatsubo, "Beef liver L-Glutamate dehydrogenase mechanism: presteady state study of the catalytic reduction of 2.oxoglutarate by NADPH.", Biochemical and biophysical research communications, vol. 67, issue 4, pp. 1527-36, 1975 Dec 15. Abstract
Jolly, R. D., K. G. Thompson, and B. G. Winchester, "Bovine mannosidosis--a model lysosomal storage disease.", Birth defects original article series, vol. 11, issue 6, pp. 273-8, 1975. Abstract
Moroi, K., and T. Sato, "Comparison between procaine and isocarboxazid metabolism in vitro by a liver microsomal amidase-esterase.", Biochemical pharmacology, vol. 24, issue 16, pp. 1517-21, 1975 Aug 15. Abstract
Wiesmann, U. N., S. DiDonato, and N. N. Herschkowitz, "Effect of chloroquine on cultured fibroblasts: release of lysosomal hydrolases and inhibition of their uptake.", Biochemical and biophysical research communications, vol. 66, issue 4, pp. 1338-43, 1975 Oct 27. Abstract
Poole-Wilson, P. A., and G. A. Langer, "Effect of pH on ionic exchange and function in rat and rabbit myocardium.", The American journal of physiology, vol. 229, issue 3, pp. 570-81, 1975 Sep. Abstract

The effects of pH variation on ionic exchange and mechanical function were studied in the arterially perfused rat and rabbit septa. The pH and PCO2 of the control perfusate were 7.40 and 39 mmHg, respectively. In the rabbit septum a metabolic acidosis (pH equals 6.82, PCO2 equals 39 mmHg) caused a loss of 16% of control tension in 12 min. Na+ and K+ exchange were unaltered. A comparable respiratory acidosis (pH equals 6.81, PCO2 equals 159 mmHg) caused a 51% loss of tension in 2 min. Na+ exchange was unaltered but K+ efflux fell from 8.9 +/- 0.6 (mean +/- SE) to 4.9 +/- 0.3 mmol/kg dry wt per min (P less than 0.001, n equals 10). A net gain of K+ of 16.9 +/- 1.7 (n equals 14) mmol/kg dry wt occurred and was attributable to a delayed fall in K+ influx relative to efflux over 15 min. The net gain could not be mimicked by epinephrine administration or blocked by propranolol and was absent in the beating rat septum and the quiescent rabbit septum. These results suggest that the net uptake of K+, which appears to be dependent on a period of depolarization, and the changes of contractility are controlled by the H+ ion concentration at a cellular site whose exchange with the extracellular space is characterized by a considerable restriction of diffusion. Changes of contractility are not related to the net uptake of K+.

Elkhadem, A., and P. Nagi, "Effectiveness of MTA pulpotomy in primary molars: a critical assessment of relevant studies.", Evidence-based dentistry, vol. 14, issue 2, pp. 46, 2013. Abstract


STUDY SELECTION: Studies that evaluated the efficacy of MTA as a pulpotomy medicament in primary teeth were included, abstracts, observational studies and case reports were excluded. Only English language studies were considered.

DATA EXTRACTION AND SYNTHESIS: Studies were assessed and graded by two reviewers using a weighted criteria based system and a qualitative summary of the evidence provided.

RESULTS: Twenty-two studies were included, 17 studies compared MTA with formocresol, four studies compared MTA with calcium hydroxide, ferric sulphate, Portland cement, calcium-enriched mixture cement (CEM) and one study compared white MTA with grey MTA.

CONCLUSIONS: Based on the assessment criteria employed, there was no evidence that MTA was better than present materials and techniques as a pulpotomy medicament.

Fahnestock, S. R., "Evidence of the involvement of a 50S ribosomal protein in several active sites.", Biochemistry, vol. 14, issue 24, pp. 5321-7, 1975 Dec 2. Abstract

The functional role of the Bacillus stearothermophilus 50S ribosomal protein B-L3 (probably homologous to the Escherichia coli protein L2) was examined by chemical modification. The complex [B-L3-23S RNA] was photooxidized in the presence of rose bengal and the modified protein incorporated by reconstitution into 50S ribosomal subunits containing all other unmodified components. Particles containing photooxidized B-L3 are defective in several functional assays, including (1) poly(U)-directed poly(Phe) synthesis, (2) peptidyltransferase activity, (3) ability to associate with a [30S-poly(U)-Phe-tRNA] complex, and (4) binding of elongation factor G and GTP. The rates of loss of the partial functional activities during photooxidation of B-L3 indicate that at least two independent inactivating events are occurring, a faster one, involving oxidation of one or more histidine residues, affecting peptidyltransferase and subunit association activities and a slower one affecting EF-G binding. Therefore the protein B-L3 has one or more histidine residues which are essential for peptidyltransferase and subunit association, and another residue which is essential for EF-G-GTP binding. B-L3 may be the ribosomal peptidyltransferase protein, or a part of the active site, and may contribute functional groups to the other active sites as well.

Elkhadem, A., and S. Wanees, "Fluoride releasing sealants may possess minimal cariostatic effect on adjacent surfaces.", Evidence-based dentistry, vol. 16, issue 1, pp. 12, 2015 Mar. Abstract

DESIGN: Randomised controlled trial.

INTERVENTION: Children with at least two sound permanent first molars and the presence of at least one sound distal surface of adjacent second primary molar were eligible. Children were randomised into three groups. In group one first permanent molars were sealed with a high-viscosity glass ionomer cement (GIC group; n = 926), group two received a resin-based fluoride containing sealant (RBF group; n = 923) and group three a resin-based sealant without fluoride (RB group; n = 927). Two examiners blind to group allocation conducted examinations at 30 months. Sealant retention and caries at D1-D3 levels was assessed. Bitewing radiographs were taken.

OUTCOME MEASURE: Caries prevalence and incidence rate ratios were calculated.

RESULTS: Two thousand seven hundred and seventy-six children were enrolled; the number of dropouts were similar in each group (GIC group; n = 75), (RBF group; n = 67), (RB group; n = 77). The prevalence of affected surfaces was significantly lower in the GIC (p = .03) and FRB groups (p = .04). Fewer new caries developed on the distal surfaces of the second primary molars in the GIC group than in the other two groups. Incidence rate ratios (IRRs) were: 0.70 (95% CI: 0.50, 0.68; p < .01) for GIC vs. RB; 0.89 (95% CI: 0.89, 1.28; p = .10) for GIC vs. FRB and 0.79 (95% CI: 0.53, 1.04; p = .005) for FRB vs RB. Partial sealant loss was higher in the GIC group (76 molars; 2.95%), compared with FRB (52 molars; 1.41%), RB group (50 molars;1.35%).

CONCLUSIONS: Fluoride-releasing sealants (high-viscosity GIC and fluoride RB) were demonstrated to provide protection against caries on the distal surface of second primary molars. This preventive strategy might contribute to maintaining the integrity of the mesial surfaces of the first permanent molars.

Makar, A. B., K. E. McMartin, M. Palese, and T. R. Tephly, "Formate assay in body fluids: application in methanol poisoning.", Biochemical medicine, vol. 13, issue 2, pp. 117-26, 1975 Jun. Abstract
Buchet, R., L. Beauvais, and C. Sandorfy, "Hydrogen bond equilibrium constants of some unusual nucleotide base pairs.", Journal of biomolecular structure & dynamics, vol. 2, issue 1, pp. 221-32, 1984 Aug. Abstract

Approximate hydrogen bond association constants were determined for base pairs formed by an adenine derivative and a number of unusual pyrimidine bases. A series is found in which the H-bond strength in the base-pairs varies. In certain cases the H-bond equilibrium constant is larger than in the adenine-thymine pair. Inosine derivatives seem to have a non-negligible chance of replacing guanosine in the guanosine-cytosine pair. Infrared, near-infrared (overtone) and NMR spectra were used to determine the equilibrium constants.

Akamatsu, N., H. Nakajima, M. Ono, and Y. Miura, "Increase in acetyl CoA synthetase activity after phenobarbital treatment.", Biochemical pharmacology, vol. 24, issue 18, pp. 1725-7, 1975 Sep 15. Abstract
Turner, A. J., and P. E. Hick, "Inhibition of aldehyde reductase by acidic metabolites of the biogenic amines.", Biochemical pharmacology, vol. 24, issue 18, pp. 1731-3, 1975 Sep 15. Abstract
Howell, R. M., and S. L. Deacon, "The interaction of clotting factor X with adsorbents containing bivalent cations.", Biochemical Society transactions, vol. 4, issue 4, pp. 718-20, 1976. Abstract
Goss, D. J., L. J. Parkhurst, and H. Görisch, "Kinetic light scattering studies on the dissociation of hemoglobin from Lumbricus terrestris.", Biochemistry, vol. 14, issue 25, pp. 5461-4, 1975 Dec 16. Abstract

The kinetics of the pH-induced dissociation of the 3 X 10(6) mol wt hemoglobin from Lumbricus terrestris (the earthworm) have been studied in a light-scattering stopped-flow apparatus. The ligand dependent dissociation data were fit well by a simple sequential model. The data for CO and oxyhemoglobin are consistent with Hb12 leads to 2Hb6 leads to 12Hb. Methemoglobin at pH 7 appears to be hexameric and the dissociation is consistent with the model: Hb6 leads to 6Hb. In a sequential decay scheme for which light-scattering changes are monitored, the relative amounts of rapid and slow phase are determined by the rate constants as well as the molecular weights of intermediate species. Assignment of the hexameric intermediate is supported by an investigation of the sensitivity of the theoretical kinetic curves to the molecular weights of the intermediates. This assignment is further supported by the following: (1) the same model will fit the data for oxy- and CO-hemoglobin at all three temperatures (a 24-29-fold variation in rate constants), (2) evidence from electron microscopy shows hexameric forms, and (3) methemoglobin is apparently stable as a hexamer at pH 7. When CO replaces O2 as the ligand, the dissociation rate increases by a factor of four. The met is about 20 times faster than the initial oxyhemoglobin dissociation rate, but perhaps more relevant for comparing dissociation of the hexamer, the met rate was respectively 100 times and 500 times faster than that for the assumed hexameric forms of CO- and oxy-hemoglobin. The activation energies for the dodecamer to hexamer dissociation and for the dissociation of the hexamer to smaller forms were about 30 kcal/mol for oxy-, CO-, and methemoglobin.

Elkhadem, A., "Large overjet may double the risk of dental trauma.", Evidence-based dentistry, vol. 16, issue 2, pp. 56, 2015 Jun. Abstract

DATA SOURCES: Medline/PubMed, SCOPUS and Google Scholar.

DATA EXTRACTION AND SYNTHESIS: Studies were split according to the type of teeth and the overjet threshold used, thus obtaining three subsets; primary teeth - overjet threshold 3-4 mm; permanent teeth - overjet threshold 3-4 mm and permanent teeth - overjet threshold 6 ± 1 mm. Pooled odds ratios for TDI were estimated for each dataset.

RESULTS: Fifty-four studies were included involving patients from five continents. The adjusted pooled odds ratios were 2.31 (95%CI; 1.01-5.27) for primary teeth with 3-4 mm overjet; 2.01 (95%CI; 1.39-2.91) for permanent teeth with 3-4 mm overjet and 2.24 (95%CI; 1.56-3.21) for permanent teeth with 6 ± 1 mm overjet.

CONCLUSIONS: The present meta-analysis of observational studies showed that large overjet may double or even triple the risk for TDI to anterior primary and permanent teeth and that, at global level, large overjet is partly responsible for 100-300 million TDIs.

Elkhadem, A., and S. Wanees, "Limited evidence suggests standard fluoride toothpaste reduces caries potential in preschool children.", Evidence-based dentistry, vol. 15, issue 1, pp. 5, 2014 Mar. Abstract

DATA SOURCES: CENTRAL, Medline, Embase, Web of Science, LILACS and BBO databases, the Brazilian database of thesis and dissertations (Banco de Teses CAPES), a Brazilian register of ethically approved projects involving human beings (SISNEP) and two registers of ongoing trials (Current Controlled Trials and Reference lists were also scanned for relevant papers. Study authors were contacted for additional information.

STUDY SELECTION: Individual or cluster-randomised or quasi-randomised controlled trials conducted in children under seven were included.

DATA EXTRACTION AND SYNTHESIS: Study selection and data abstraction were conducted by two reviewers independently. Risk of bias assessment was undertaken using the Cochrane Collaboration tool. Meta-analyses of prevented fractions (PF) were performed to assess the effect of fluoride toothpaste on the dmft and dmfs. Meta-analyses were also performed to obtain a pooled relative risk (RR) to assess the effect of fluoride toothpastes on the proportion of children developing caries.

RESULTS: Eight studies were included. When standard F toothpastes were compared to placebo or no intervention, significant caries reduction at surface (PF = 31%; 95% CI 18-43; 2644 participants in five studies), tooth (PF = 16%; 95% CI 8-25; 2555 participants in one study) and individual (RR = 0.86; 95% CI 0.81-0.93; 2806 participants in two studies) level were observed. Low F toothpastes were effective only at surface level (PF = 40%; 95% CI 5-75; 561 participants in two studies).

CONCLUSIONS: Standard F toothpastes are effective in reducing dental caries in the primary teeth of preschool children and thus their use should be recommended to this age group.

Mier, P. D., and J. J. van den Hurk, "Lysosomal hydrolases of the epidermis. I. Glycosidases.", The British journal of dermatology, vol. 93, issue 1, pp. 1-10, 1975 Jul. Abstract

Seven distinct glycosidases (EC 3.2) have been characterized in guinea-pig epidermis. Their properties indicate them to be of lysosomal origin. The 'profile' of the epidermal glycosidases is significantly different from that reported for whole skin, the activities of beta-galactosidase and beta-acetylglucosaminidase being very high and those of the remaining enzymes relatively low in epidermis.

Bhagwat, V. M., and B. V. Ramachandran, "Malathion A and B esterases of mouse liver-I.", Biochemical pharmacology, vol. 24, issue 18, pp. 1713-7, 1975 Sep 15. Abstract
Anderson, T. R., and T. A. Slotkin, "Maturation of the adrenal medulla--IV. Effects of morphine.", Biochemical pharmacology, vol. 24, issue 16, pp. 1469-74, 1975 Aug 15. Abstract
Asakura, T., K. Adachi, M. Shapiro, S. Friedman, and E. Schwartz, "Mechanical precipitation of hemoglobin köln.", Biochimica et biophysica acta, vol. 412, issue 2, pp. 197-201, 1975 Dec 15. Abstract

Hb Köln (beta 98 Val leads to Met) was found to precipitate rapidly during mechanical shaking. The rate of precipitation of Hb Köln is 5-6 times faster than that of Hb S. The kinetics of precipitation of the patient's hemolysate, which is a mixture of Hb Köln and Hb A, showed a biphasic curve indicating that Hb Köln precipitates independently from Hb A. The instability of Hb Köln may be attributed to the conformational change in the vicinity of heme. The mechanical shaking may be used as a new method for detection and quantitation of hemoglobin Köln and other unstable hemoglobins.

Smith, R. J., and R. G. Bryant, "Metal substitutions incarbonic anhydrase: a halide ion probe study.", Biochemical and biophysical research communications, vol. 66, issue 4, pp. 1281-6, 1975 Oct 27. Abstract