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PubMed2003

Propofol inhibits volume-sensitive chloride channels in human coronary artery smooth muscle cells.

Volume-sensitive chloride channels (VSCC) play an important role in regulation of cell volume and electrical activity. Activation of vascular smooth muscle VSCC causes smooth muscle depolarization and contraction. We investigated the effects of propofol on VSCC in cultured human coronary artery smooth muscle cells by using the chloride-sensitive dye 6-methoxy-N-ethylquinolinium (MEQ). To activate VSCC, cells were superfused for 2 min with hypotonic gluconate solutions and then potassium thiocyanate solution. The percentage reduction in MEQ fluorescence during 60 s in the presence of potassium thiocyanate was measured and used as an index of VSCC activity. 5-Nitro-2-(3-phenylpropylamino) benzoic acid (NPPB), a well characterized chloride channel blocker, and propofol were dissolved in hypotonic gluconate solution to test their effect on VSCC activity. The reduction in fluorescence was inversely related to osmolality, indicating that activation of VSCC is osmolality dependent. Hypotonic gluconate solution (210 mOsm/kg H(2)O) reduced fluorescence by 38.9% +/- 2.6% of the baseline value. The reduction in fluorescence was dose-dependently inhibited by NPPB. Propofol at 0.3, 1, 3, 10, 30, and 100 micro g/mL significantly inhibited the reduction in fluorescence to 23.6% +/- 4.8%, 19.7% +/- 7.4%, 18.2% +/- 3.5%, 17.6% +/- 5.0%, 15.8% +/- 3.1%, and 10.3% +/- 3.9% of the baseline value, respectively. Our results indicate that propofol inhibits VSCC in a dose-dependent manner in human coronary artery smooth muscle cells.

Anesthetics, Intravenous↗
PubMed1991

Participation of monocarboxylic anion and bicarbonate exchange system for the transport of acetic acid and monocarboxylic acid drugs in the small intestinal brush-border membrane vesicles.

A participation of bicarbonate exchange system for the transport of acetic acid and the related monocarboxylic acid drugs in the intestinal brush-border membrane vesicles (BBMVs) was investigated. The uptake of [3H]acetic acid at 37 degrees C by BBMVs was markedly stimulated and showed a clear overshoot phenomenon in the presence of outward-directed bicarbonate gradient (pHin = 7.5, [KHCO3]in or [NaHCO3]in = 100 mM; pHout = 7.5, [K-gluconate]out or [Na-gluconate]out = 100 mM). This uptake process was saturable (Kt = 50.4 +/- 4.96 mM and Jmax = 11.6 +/- 0.61 nmol/mg protein/10 s) and was inhibited by DIDS (4,4-diisothiocyano-2,2'-disulfonic acid stilbene disodium salt) and furosemide, anion exchange inhibitors, and by many monocarboxylates. The initial uptake of [3H]acetic acid was competitively inhibited by salicylic acid, suggesting the common transport between acetic acid and salicylic acid. At lower extravesicular pHs and in the presence of outward-directed bicarbonate gradient (pHin = 7.5 [KHCO3]in = 100 mM; pHout = 6.0 or 5.0, [K-gluconate]out = 100 mM) where membrane potential was clamped to zero by K(+)-valinomycin, the uptake of [3H]acetic acid showed an overshoot phenomenon, whereas the uptake was significantly decreased in the presence of carbonyl cyanide p-trifluoromethoxyphenylhydrazone, a protonophore. It was concluded, therefore, that there are one or two mechanisms for the carrier-mediated transport of acetic acid and monocarboxylates related to bicarbonate exchange systems in rabbit intestinal BBMVs: 1) proton gradient independent and bicarbonate exchange system; 2) proton gradient dependent and bicarbonate exchange system.

Acetates↗
PubMed1988

[Effect of NH4+ on synaptosomal membrane potential in the rat brain].

The effect of NH4+ on synaptosomal membrane potential was examined using rat brains. The membrane potential was measured by the rhodamine 6G fluorescence method. Both NH4+ diffusion potential (NH4+-potential) and K+ diffusion potential (K+-potential) were observed in the synaptosomes. Upon replacement of medium Cl- with SCN-, both K+- and NH4+-potentials depolarized. On the other hand, replacement of medium Cl- with gluconate resulted in the hyperpolarization of K+-potential, but not of NH4+-potential. Ethacrynic acid (0.3 mM), a Cl- -ATPase inhibitor, depolarized both K+(Cl-)- and NH4+ (Cl-)-potentials. In the presence of ethacrynic acid, both of the potentials were further depolarized by replacement of medium Cl- with SCN-, but not with gluconate-. Picrotoxin (5 mM), a Cl- channel inhibitor, did not significantly affect either K+- or NH4+-potential. In the presence of picrotoxin, replacement of medium Cl- with SCN- depolarized both K+- and NH4+-potentials with or without ethacrynic acid. Gluconate depolarized the K+-potential with ethacrynic acid and the NH4+-potential with or without ethacrynic acid. These findings suggest that NH4+ forms a diffusion potential in nerve endings, and inhibits the anion-mediated hyperpolarization through mechanisms other than anion channels.

Ammonia↗
PubMed2000

In vitro dialyzability of zinc from different salts used in the supplementation of infant formulas.

Seven zinc salts--acetate, chloride, lactate, sulfate, citrate, gluconate, and oxide--were added to milk--and soy-based infant formulas to estimate possible differences in zinc availability depending on the type of salt used. For this purpose, an in vitro method that estimates the dialyzability of the element (i.e., the fraction available for absorption) was applied. Zinc dialyzability is always higher in milk-based products than in soy products, even when the total zinc contents are higher in the latter. The salts can be classified according to the zinc dialyzability in the two types of formulas as follows: oxide > gluconate = chloride = lactate > citrate = acetate > sulfate. Therefore, according to the dialysis percentage, oxide and gluconate are the compounds of choice for zinc supplementation of infant formulas.

Animals↗
PubMedDate not supplied

Modulation by monovalent anions of calcium and caffeine induced calcium release from heavy sarcoplasmic reticulum vesicles.

Both calcium and caffeine induced calcium release from actively loaded heavy sarcoplasmic reticulum vesicles were studied to analyze the dependence of both activities on the composition of the release medium with respect to monovalent anions. Calcium is unable to induce net calcium release while caffeine remains effective as releasing agent when the experimental media contain neither chloride nor nitrate ions. Caffeine induced calcium release is not suppressed by chelating residual medium calcium (approximately 0.5-1 microM) with 2 mM EGTA added 15 s prior to 10 mM caffeine. Calcium release from vesicles loaded in media containing 0.2 M gluconate as monovalent anion is induced when the medium is supplemented with chloride or nitrate. The release amplitude increases linearly when K-gluconate is replaced by KCl. At constant ionic strength the release amplitude becomes maximal at a chloride concentration of 0.2 M. The chloride effect completely disappears when 2 mM EGTA are added simultaneously. When chloride is replaced by nitrate, as releasing agent, maximal release is achieved already by addition of 0.1 M K-nitrate. The releasing effect of nitrate can only partially be suppressed by EGTA. The different effectiveness of gluconate, chloride and nitrate as calcium release supporting ions corresponds to their activating effect on the binding of ryanodine to the calcium release channel in the vesicular membranes.

Animals↗
PubMed1990

Irrigation with 0.06% chlorhexidine in naturally occurring gingivitis. II. 6 months microbiological observations.

In an examiner blind positive/negative controlled 6-month study, the efficacy of supragingival irrigation with 0.06% chlorhexidine gluconate on the marginal and subgingival microflora in naturally occurring gingivitis was evaluated. The 222 patients enrolled in the study were assigned to one of four groups: Group 1: Once daily irrigation with 300 ml water followed by irrigation with 200 ml 0.06% chlorhexidine gluconate (experimental); Group 2: Twice daily rinsing with 15 ml 0.12% chlorhexidine (positive control); Group 3: Once daily irrigation with 500 ml water (irrigation control) and Group 4: Sodium fluoride dentifrice for normal oral hygiene only (negative control). All groups received the same sodium fluoride dentifrice for tooth brushing. All patients received a supra- and subgingival oral prophylaxis after baseline examination and at the end of the investigation. Plaque samples were analyzed from 105 patients at baseline, 93 patients at 3 months and 88 patients at 6 months. The 6-months results demonstrated that, when compared with tooth brushing alone, adjunctive supragingival irrigation with 0.06% chlorhexidine gluconate was most effective by significantly reducing (P less than or equal to 0.008) both log10 CFU and % of Gram-negative anaerobic rods and black-pigmented Bacteroides. Chlorhexidine rinse also significantly (P less than or equal to 0.008) reduced log10 CFU of black-pigmented Bacteroides at 6 months. Both chlorhexidine regimens significantly (P less than or equal to 0.008) increased the % of Gram-positive facultative cocci compared to water irrigation at 3 months. Water irrigation had a limited effect on any of the assessed bacterial groups (log10 CFU and %).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1999

The utility of a growth factor: r-HuEPO as a treatment for preoperative autologous blood donation in gynecological tumor surgery.

The use of r-HuEPO and sodium ferrous gluconate has been shown to be a safe and effective treatment which can be used by transfusional centers and surgeons to avoid allogeneic blood transfusions and to schedule short-term selective surgery. In this study the authors submitted 20 patients scheduled to undergo surgery for gynecological tumors to a program of pre-operative autologous blood donation. All the patients received both r-HuEPO and sodium ferrous gluconate in the pre- and post-donation period. r-HuEPO was administered subcutaneously in a dose of 200 IU/kg thrice weekly during the week before and after autologous blood donation (400 ml). Sodium ferrous gluconate was administered intravenously shortly before the first and fourth administration of 125 mg of r-HuEPO. Surgery was scheduled to be performed 10-15 days after the last r-HuEPo administration, i.e. within 15-20 days from blood donation. All the patients were tested for the following blood chemistry parameters: hematocrit, hemoglobin, sideremia and ferritin at treatment start, prior to donation, at treatment end, prior to autologous blood infusion and on the third and seventh day after surgery. No patient receiving r-HuEPO required allogeneic blood transfusion as both the hematocrit and hemoglobin values remained normal. r-HuEPO was observed to be a safe and effective treatment to be used in autologous blood donation programs in all patients scheduled to undergo surgery. It limits the decrease of hematocrit values following autologous blood donation thus enabling all the patients who for a variety of reasons to refuse allogeneic blood infusion to predeposit autologus blood shortly before the date scheduled for surgery.

Adult↗
PubMedDate not supplied

A new protocol of iron therapy combined with epoetin alpha as a treatment for preoperative autologous blood donation in gynaecological tumor surgery.

The use of epoetin alpha and sodium ferrous gluconate has been shown to be a safe and effective treatment which can be used to avoid allogeneic blood transfusions and to plan short term elective surgery. In this study the authors submitted 20 patients, scheduled to undergo surgery for gynaecological tumors, to a program of pre-operative autologous blood donation. All the patients received both epoetin alpha and sodium ferrous gluconate in the pre- and post-donation period. Epoetin alpha was administered subcutaneously at a dose of 200 IU/kg thrice a week during the week before and after autologous blood donation (400 ml). Sodium ferrous gluconate was administered intravenously shortly before the first and fourth administration of 125 mg epoetin alpha, and shortly before the third and sixth administration of 62.5 mg epoetin alpha. Surgery was scheduled to be performed 10-15 days after the last epoetin alpha administration, i.e. within 15-20 days from blood donation. All the patients were tested for the following blood chemistry parameters: hematocrit, haemoglobin, sideraemia and ferritin at treatment start, before donation, at treatment end, before autologous blood infusion and on the third and seventh day after surgery. No patient receiving epoetin alpha required allogeneic blood transfusion, as both the hematocrit and haemoglobin values remained normal. Epoetin alpha was observed to be a safe and effective treatment to be used in autologous blood donation programs in all patients scheduled to undergo surgery. It limits the decrease of hematocrit values following autologous blood donation thus enabling all the patients, who for a variety of reasons refuse allogeneic blood infusion, to predeposit autologous blood shortly before the date scheduled for surgery.

Adult↗
PubMedDate not supplied

Some characteristics of primary hyperparathyroidism in Vietnamese immigrants living in Southern California.

OBJECTIVE: To characterize primary hyperparathyroidism (PHP) in Vietnamese immigrants living in southern California and to summarize the results of treatment. METHODS: We describe 11 patients (8 women and 3 men) with a mean age of 57.91 years who underwent follow-up from 1991 to 1995 after PHP was diagnosed. The patients had no specific complaints. Four patients had a history of kidney stones, and five had chronic hypertension. Only five patients had high levels of total serum calcium; the other six patients had normal or fluctuating levels of total serum calcium. All patients, however, had high levels of intact parathyroid hormone (PTH) and ionized calcium. Preoperatively, parathyroid imaging with technetium-99m sestamibi demonstrated persistently increased parathyroid gland uptake. RESULTS: In all nine patients who underwent surgical treatment, an adenoma was found in the parathyroid glands; two patients refused operative intervention. The mean serum phosphate was in the low-normal range and increased postoperatively (2.70 versus 3.52 mg/dL; P<0.001). The mean serum chloride level also decreased postoperatively (104.62 versus 100.78 mEq/L; P<0.001). The ratio of chloride/phosphate decreased significantly after adenoma removal (39.44 versus 29.21; P<0.001). Six patients received calcium gluconate either alone or in combination with vitamin D supplements for hypocalcemia postoperatively. The other three patients, however--who did not receive calcium supplements postoperatively--had persistently high levels of intact PTH but normal serum Ca++ levels and subsequently were treated effectively with calcium gluconate and vitamin D. CONCLUSION: The presence of hypercalcemia, especially Ca++, and an increased level of intact PTH establishes the diagnosis of PHP. After parathyroidectomy, the persistence of high levels of intact PTH in association with normal serum Ca++ suggested the presence of secondary hyperparathyroidism, which was treated effectively with calcium gluconate and vitamin D. These patients had the same clinical picture as other ethnic groups with PHP, but they needed either calcium alone or calcium and vitamin D supplements after parathyroidectomy because of their bone loss from prolonged PHP.

Journal Article↗
PubMed2005

Parenteral iron therapy: a single institution's experience over a 5-year period.

Many patients require parenteral iron therapy for optimal correction of anemia, including cancer patients who require erythropoietic drugs. Available parenteral iron therapy options include iron dextran, iron gluconate, and iron sucrose. The purpose of this study is to summarize our institution's experience with parenteral iron therapy over a 5-year period, with a focus on comparative safety profiles. All patients receiving parenteral iron therapy over this period were included in the analysis. Chi-squared test and Fisher's exact test were used to compare the adverse event rates of each product. A total of 121 patients received 444 infusions of parenteral iron over this period. Iron dextran was the most commonly used product (85 patients) and iron sucrose was the least used (2 patients). Iron gluconate was used by 34 patients. Overall adverse event rates per patient with iron dextran and iron gluconate were 16.5% and 5.8%, respectively (P = .024). Premedication with diphenhydramine and acetaminophen before infusions of iron dextran reduced adverse event rates per infusion from 12.3% to 4.4% (P = .054). Test doses of iron dextran were used 88% of the time for initial infusions of iron dextran. All adverse events for all parenteral iron products were mild or moderate. There were no serious adverse events and no anaphylaxis was observed. Our results suggest that, if test doses and premedications are used, iron dextran is an acceptable product to treat iron deficiency.

Acetaminophen↗
PubMed1964

THE RELATIONSHIP OF DOSAGE SCHEDULE TO THE BLOOD LEVEL OF QUINIDINE, USING ALL AVAILABLE QUINIDINE PREPARATIONS.

Blood quinidine levels obtained by single and multiple dosage schedules of all available quinidine preparations were ascertained. A maintenance blood level of 4 to 7 mg./l. of quinidine was considered a desirable range to prevent recurrence of auricular fibrillation in patients previously converted to sinus rhythm. Quinidine sulfate, quinidine gluconate, dihydroquinidine gluconate and quinidine polygalacturonate were given in dosage schedules of one tablet (equivalent to 200 mg. quinidine) every eight hours for four days, then two tablets every eight hours for three days. Blood quinidine levels were determined the same time each day. Schedules of two tablets of quinidine sulfate or quinidine gluconate every eight hours resulted in blood levels between 4 and 7 mg./l. Similar dosage schedules of the other preparations did not produce levels of this order, nor did quinidine polygalacturonate administered in a 12-hourly schedule. Serious respiratory arrest occurred in one case following quinidine sulfate. No other toxic reactions were noted in this study.

Atrial Fibrillation↗
PubMed2005

[Effects of L-threonate on bone resorption by osteoclasts in vitro].

OBJECTIVE: To clarify if calcium L-threonate and sodium L-threonate have inhibitory effects on the bone resorption of rabbit's osteoclasts in vitro. METHODS: This study contained a total of 16 culture groups, including one group as control and 5 groups treated by 5 drugs (calcium D-threonate, sodium L-threonate, alendronate, 17beta-estradiol and calcium gluconate) each at the final concentrations of 10(-9) mol/L, 10(-7) mol/L, 10(-5) mol/L respectively. After 7 days, eight bone slices of every group were stained with toluidine blue and the areas of resorptive pits were analyzed under light microscope; the concentrations of C-telopeptide of type I collagen (CTx or Crosslaps) in culture supernatants were measured by ELISA. RESULTS: (1) The resorption area and the CTx concentration of the Calcium L-threonate groups were reduced significantly as compared with those of control and of Calcium gluconate groups respectively. The resorption area and CTx level of the Sodium L-threonate groups were significantly reduced when compared with those of the control, but the effects of Calcium gluconate groups were not so. (2) The reduction in the resorption area and CTx concentration of Calcium L-threonate group was more than that of Sodium L-threonate group. (3) The reductive effect of the high concentration (10(-5)) group of Calcium L-threonate on the area and CTx level was corresponding to that of 17beta-estradiol at a concentration between 10(-7) and 10(-9). (4) The resorption area was related to the CTx concentration (r=0.876). (5) The CTX level was much more sensitive, precise and stable than the concentration. CONCLUSION: L-threonate, especially calcium L-threonate could inhibit the bone resorption of osteoclasts in vitro, and its effect might be related to the radical of L-threonic acid. The CTx concentration in culture supernatants might be an effective marker quantitatively reflecting the bone resorption by osteoclasts in vitro.

Alendronate↗
PubMed2003

[Fermentative production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) by recombinant Aeromonas hydrophila 4AK4 (pTG01)].

Copolyesters consisting of 3-hydroxybutyrate (3HB) and 3-hydroxyhexanoate (3HHx) (PHBHHx), a new type of biodegradable material, are receiving considerable attentions recently. The material properties are strongly related to the 3HHx fraction of PHBHHx. As the 3HHx fraction increase, crystallinity and melting point of PHBHHx decrease, flexibility and tractility increase. PHBHHx of different 3HHx fraction can meet different demands of commercial application and research. Aeromonas are the best studied PHBHHx-producing strains. Recent studies have been focused on optimizations of fermentative culture media and culture conditions for low-cost and efficient fermentative production. Aliphatic substrates such as long-chain fatty acid and soybean oil were used in the PHBHHx fermentation as the sole carbon source and energy source. Two-stage fermentation method was also developed for more efficient PHBHHx production. While studies on Aeromonas hydrophila revealed that the monomer composition of PHBHHx could not easily be regulated by fermentative process engineering methods such as changing substrates and fermentative conditions because precursors involved in the PHBHHx synthesis were all from the beta-oxidation pathway. In this study, phbA gene encoding beta-ketothiolase and phbB gene encoding acetoacetyl-CoA reductase were introduced into a PHBHHx-producing strain Aeromonas hydrophila 4AK4 so as to provide a new 3HB precursors synthesis way. phbA gene encodes beta-ketothiolase which can catalyze two acetyl-CoA to form acetoacetyl-CoA; phbB gene encodes acetoacetyl-CoA reductase catalyzing acetoacetly-CoA into 3HB-CoA which is the precursor of 3HB. The introduced novel 3-hydroxybutyrate precursor synthesis pathway allowed the recombinant strain to use unrelated carbon source such as gluconate to provide 3HB precursors for PHBHHx synthesis. Shake-flask experiments were carried out to produce PHBHHx of controllable monomer composition and fermentations in 5 L fermentor were also proceeded for confirmation of these result in large-scale culture. In flask culture, it was possible to reduce the 3HHx mol fraction in PHBHHx from 15 % in the wild type to 3% - 12% in the recombinant by simply changing the ratio of gluconate to lauric acid in the culture media. When lauric acid was used as the sole carbon source, 51.5 g/L Cell Dry Weight (CDW) containing 62 % PHBHHx with 9.7 % 3HHx mol fraction was obtained in 56 hours of fermentation in a 5 liter fermentor. When co-substrates of sodium gluconate and lauric acid (1:1) were used as carbon sources, 32.8 g/L CDW containing 52 % PHBHHx with 6.7% 3HHx mol fraction was obtained in 48 hours of fermentation. These results showed the possibility for fermentative production of PHBHHx with controllable monomer composition.

3-Hydroxybutyric Acid↗
PubMed2004

[Studies on synthesis of polyhydroxyalkanoate consisting of 3-hydroxyvalerate by Aeromonas hydrophila].

Polyhydroxyalkanoates (PHA) is a family of microbially synthesized polyesters consisting of various 3-hydroxyalkanoate monomers. Aeromonas hydrophila 4AK4 could be able to synthesize PHA copolymer consisting of 3-hydroxybutyrate (3-HB) and 3-hydroxyhexanoate (3-HHx). No data has been reported about the ability to synthesize the PHA with other monomers in A. hydrophila. In this study, propionic acid, valeric acid, heptanoic acid, nonanoic acid and undecanoic acid were used together with gluconate to find out whether A. hydrophila 4AK4 could synthesize the PHA consisting of odd carbon atom number monomers. The result showed that A. hydrophila 4AK4 could not growth when supplied with propionic acid, valeric acid, heptanoic acid and nonanoic acid and only undecanoic acid could be used to synthesize PHA. Wild type and recombinant A. hydrophila 4AK4 harboring phaA (beta-ketothiolase) and phaB (acetoacetyl-CoA reductase) were cultivated with undecanoic acid and glucose or undecanoic acid and gluconate served as carbon sources. PHA consisting of 3-HB and 3-hydroxyvalerate (3-HV) could be produced by both wild type and recombinant A. hydrophila 4AK4 and the latter could produce PHA with more 3-HB monomer. When the ratio of glucose or gluconate to undecanoic acid was 1:1, the cell dry weight (CDW) of A. hydrophila 4AK4 reached 1.14 g/L and PHA content was 60% of the CDW after cultivation for 24 h. When lauric acid and undecanoic acid were served as co-substrate, A. hydrophila 4AK4 could produce copolyester consisting of 3-HB, 3-HV and 3-HHx. Along with the increase of undecanoic acid proportion in the mixed carbon source, the 3-HV content of copolymer was increased while the 3-HB and 3-HHx content were decreased. In all cases, the CDW decreased along with the increase of undecanoic acid concentration, which indicated that undecanoic acid was not very good for A. hydrophila 4AK4 growth.

Aeromonas hydrophila↗
PubMed1990

Iron(III)-mediated photolysis of outer arm dynein ATPase from sea urchin sperm flagella.

Irradiation of outer arm dynein ATPase from sea urchin sperm tail flagella at 365-410 nm in the presence of Fe(III)-gluconate complex and ATP produces photolytic cleavage at two distinct sites on the beta heavy chain, located approximately 250 and approximately 230 kDa from its amino terminus. The former cut is close to or identical with the V1 site of the vanadate-mediated photocleavage (Gibbons, I.R., Lee-Eiford, A., Mocz, G., Phillipson, C. A., Tang, W.-J.Y., and Gibbons, B.H. (1987) J. Biol. Chem. 262, 2780-2786. The rate of photolysis shows a hyperbolic dependence on Fe(III)-gluconate concentration with half-maximal rate occurring at 23 microM at pH 6.3. In the presence of 0.1-0.5 mM Fe(III)-gluconate-ATP, approximately 58% of the beta chain becomes cleaved with a half-time of about 34 s; the remainder of the beta chain and almost all of the alpha chain are resistant to cleavage. This photolytic cleavage of the beta chain is accompanied by an approximately parallel loss of the dynein latent ATPase activity, whereas the Triton-activated ATPase is lost to a somewhat greater extent. Mg2+ concentrations above approximately 3 mM inhibit photolysis. Substitution of ADP for ATP changes the pattern of cleavage so that both the alpha and beta heavy chain undergo scission but at the 250-kDa site only. AMP, adenyl-5'-yl imidodiphosphate and Fe(II) do not support cleavage at either site. Trivalent rhodium-ATP complexes, as models of MgATP, can also catalyze photolysis of the beta chain at the 250-kDa site. These results suggest that photolysis results from the activation of an Fe(III)-ATP complex bound to the hydrolytic ATP binding site of the beta chain and that both Fe(III) cleavage sites are located close to the nucleotide binding site in the tertiary folding of the beta heavy chain. The cleavage reaction possibly involves initial photoreduction of Fe(III) bound at the Mg2+ binding site in the dynein.Fe.ATP complex, followed by covalent modification of an amino acid side chain that leads to eventual peptide scission.

Adenosine Triphosphatases↗
PubMed1988

Retinal toxicity of intravitreal ethyldeoxyuridine and zinc.

We investigated the toxicity of intravitreal zinc sulfate, zinc gluconate, and ethyldeoxyuridine (EDU) in albino rabbits. Various concentrations of EDU were added to the infusion solution during pars plana vitrectomy. Retinal changes were observed by light microscopy after intravitreal injections containing 20 micrograms of zinc gluconate, all concentrations of zinc sulfate, and 400 micrograms of EDU. No histologic or electroretinographic alterations occurred with doses of 15 micrograms or less of zinc gluconate or 200 micrograms or less of EDU. When added to the vitrectomy solution, concentrations of 20 micrograms/mL or less of EDU appeared nontoxic to the rabbit retina.

Animals↗
PubMed1988

[Antimicrobial activity of antiseptics].

In the study, the antimicrobial activities of 7.5% povidone-iodine, 4% chlorhexidine gluconate, 1.5% chlorhexidine gluconate, 1.5% chlorhexidine gluconate with cetrimide mixture, 10% benzalconium chloride, dust detergent and soap as well as changes in activity in due course of time have been investigated. It has been observed that the effect of germicides on Staphylococcus aureus, Pseudomonas aeruginosa, Enterobacter cloacae and Candida strains increased in time. Soap had no germicidal effect. The difference between the of antiseptics on the residuent flora of the hands immediately and those two hours later was found to be statistically insignificant.

Anti-Infective Agents, Local↗
PubMed1985

The isozymes of glucose-phosphate isomerase (GPI-A2 and GPI-B2) from the teleost fish Fundulus heteroclitus (L.).

The fish, Fundulus heteroclitus (L.), like most advanced teleosts, possesses duplicate loci for the glycolytic enzyme, glucose-phosphate isomerase (D-glucose-6-phosphate ketol-isomerase, EC 5.3.1.9). The locus for the GPI-A2 (where GPI represents glucose-phosphate isomerase) isozyme is preferentially expressed in anaerobic tissues such as white skeletal muscle, while GPI-B2 predominates in aerobic tissues like liver and red muscle. We questioned whether this tissue specificity would be reflected in unique structural and functional characteristics of the respective isozymes. Consequently, an analysis of the two isozymes was undertaken. The enzymes were purified by a combination of ion-exchange chromatography and isoelectric focusing. Each isozyme was characterized as to native and subunit molecular weight, isoelectric pH, and susceptibility to thermal denaturation. Both were dimeric enzymes, with native molecular masses of 110 kDa. The isoelectric pH values for GPI-A2 and GPI-B2 were 7.9 and 6.4, respectively. Differences were apparent in thermal stability, i.e. GPI-A2 was more stable than GPI-B2. Kinetic properties were investigated as a function of both pH and temperature. The Km values for fructose 6-phosphate (Fru-6-P) differed between the isozymes at low pH, but no significant differences were observed at higher pH. The inhibition constant (Ki) for 6-phosphogluconate (6-P-gluconate) was pH dependent. GPI-A2 was slightly more sensitive to 6-P-gluconate inhibition than GPI-B2 between pH 7.0 and 8.5. The Km for Fru-6-P was temperature dependent for the GPI-B2 isozyme, but relatively temperature independent for GPI-A2 between 10 and 35 degrees C. The Ki for 6-P-gluconate was temperature dependent for both isozymes. The Ki values for GPI-A2 were consistently lower than those for GPI-B2. Energies of activation differed between the two isozymes by 4.4 kcal with GPI-A2 having the lower value. While delta G values were identical for the isozymes, their delta H and delta S values differed significantly. The structural and kinetic differences that exist between the glucose-phosphate isomerase isozymes appear to be tailored to the unique metabolic demands of the tissues in which these Gpi loci are expressed.

Animals↗