Patients with biallelic mutations in the chloride channel gene CLCNKB: long-term management and outcome

BACKGROUND: Little information on the management and long-term follow-up of patients with biallelic mutations in the chloride channel gene CLCNKB is available. METHODS: Long-term follow-up was evaluated from 5.0 to 24 years (median, 14 years) after diagnosis in 13 patients with homozygous (n = 10) or compound heterozygous (n = 3) mutations. RESULTS: Medical treatment at last follow-up control included supplementation with potassium in 12 patients and sodium in 2 patients and medical treatment with indomethacin in 9 patients. At the end of follow-up, body height was 2.0 standard deviation score or less in 6 patients; 2 of these patients had growth hormone deficiency. Body weight (chloride channel gene CLCNKB tend to present with pathological proteinuria and impaired kidney function after a median follow-up of 14 years, and growth retardation is common and sometimes related to growth hormone deficiency in these patients.

Novel chloride channel mutations leading to mild myotonia among Chinese

We describe two Chinese families with a mild form of the myotonia congenita due to novel chloride channel (ClCN1) mutations. In one case, heterozygous I553F and H555N mutations were found. The patient shared the I553F mutation with his healthy father, and his mother had a history of mild myotonia when she was younger. In another family, autosomal dominant myotonia congenita was due to a L844F change. The physiological effects of the mutations were examined by using the two-electrode voltage-clamp technique after expression of the channels in Xenopus oocytes. All mutations drastically shifted the voltage required for half-maximal activation, more under conditions mimicking the homozygous situation, than under conditions mimicking the heterozygous situation. The larger effect was seen in the compound heterozygous situation combining the I553F and the H555N mutations. Our data suggest that myotonia congenita caused by CLCN1 mutations in Chinese have similar variable features to those found in the West.

Electrolysis of Molten Mixtures of Galena and Lead Chloride.

Electrolysis of molten mixtures of lead chloride and galena was carried out under various conditions of temperature, time, composition, and current densities; without a diaphram, and with various diaphrams. Continuous runs, with necessary additions of lead sulfide and lead chloride to maintain a melt of the proper composition, were attempted on a small scale.

Electro-Deposition of Iron from a Chloride Bath

Iron was electro-deposited from a ferrous chloride bath. Studies were made of deposits formed when current density was varied, and fin­ally when both current density and temperature were changed. An attempt was made to lay the ground work for a long range study of the chloride bath, and to determine the most simple conditions possible for obtaining a smooth, even, and thick deposit.

Studies on the reduction of the nitro group in 3-aryl-2-methylene-4-nitro-alkanoates afforded by the Baylis-Hillman adducts: Synthesis of 4-aryl-3-methylene-2-pyrrolidinones and 3-(1-alkoxycarbonyl-vinyl)-1H-indole-2-carboxylates

The formation of substituted 2-pyrrolidinones and indoles by the reduction of the secondary nitro group in appropriate 3-aryl-2-methylene-4-nitroalkanoates afforded by Baylis-Hillman chemistry via different reducing agents is described. The 3-aryl-2-methylene-4-nitroalkanoate obtained from SN2 nucleophilic reaction between the acetate of Baylis-Hillman adducts and ethyl nitroacetate upon reduction with indium-HCl furnishes a mixture of cis and trans substituted phenyl-3-methylene-2-pyrrolidinones. In contrast, similar reductions of analogous substrates derived from nitroethane stereoselectively furnished only the trans substituted phenyl-3-methylene-2-pyrrolidinones. On the other hand the SnCl2.2H2O-promoted reductions of substrates derived from nitro ethylacetate give oxime derivatives while the ones obtained from nitroethane yield a mixture of cis and trans 4-aryl-3-methylene-2-pyrrolidinones. Alternatively, the SnCl2.2H2O-promoted reduction of substituted 2-nitrophenyl-2-methylene-alkanoate furnished from ethyl nitroacetate yields 3-(1-alkoxycarbonyl-vinyl)-1H-indole-2-carboxylate while indium-promoted reaction of this substrate leads to a complex mixture. Analogous reactions with SnCl2.2H2O of substituted 2-nitrophenyl-2-methylene-alkanoate obtained from nitroethane yield 4-alkyl-3-methylene-2-quinolones in moderate yields

An alternate approach to quinoline architecture via Baylis-Hillman chemistry: SnCl2-mediated tandem reaction toward synthesis of 4-(substituted vinyl)-quinolines

An alternate approach to densely substituted quinolines from the products of SN2 nucleophilic substitution reaction between the acetyl derivatives of the Baylis-Hillman adducts obtained from 2-nitrobenzaldehydes and the carbonyl group containing carbon nucleophiles is described. Treatment of these compounds with SnCl2, trigger a tandem reaction wherein reduction of the nitro group is followed by a remarkably regioselective intramolecular cyclization and subsequent dehydrogenation to afford 4-(substituted vinyl)-quinolines.

Effect of tin-chloride pretreatment on bond strength of two adhesive systems to dentin

OBJECTIVES: To determine the effect on resin composite-to-dentin bond strength of incorporation of an acidic tin-chloride pretreatment in two adhesive systems. MATERIALS AND METHODS: Human molars were ground to expose mid-coronal dentin. For microtensile bond strength (μTBS) testing, dentin was treated with Optibond FL or Clearfil SE according to one of six protocols (n = 22/group). Group 1: Phosphoric acid etching, Optibond FL Prime, Optibond FL Adhesive (manufacturer's instructions; control); Group 2: Tin-chloride pretreatment, Optibond FL Prime, Optibond FL Adhesive; Group 3: Phosphoric acid etching, tin-chloride pretreatment, Optibond FL Prime, Optibond FL Adhesive; Group 4: Clearfil SE Primer, Clearfil SE Bond (manufacturer's instructions; control); Group 5: Phosphoric acid etching, Clearfil SE Primer, Clearfil SE Bond; and Group 6: Tin-chloride pretreatment, Clearfil SE Primer, Clearfil SE Bond. The molars were then built up with resin composite (Clearfil Majesty Esthetic). After storage (1 week, 100  % humidity, 37 °C) the μTBS was measured and failure mode was determined. Additionally, pretreated dentin surfaces were evaluated using SEM and EDX. The μTBS results were analyzed statistically by a Welch Two Sample t-test and a Kruskal-Wallis test followed by exact Wilcoxon rank sum tests with Bonferroni-Holm adjustment for multiple testing (α = 0.05). RESULTS: When Optibond FL was used, partial or total replacement of phosphoric acid with tin-chloride decreased μTBS significantly. In contrast, when Clearfil SE was used, inclusion of a tin-chloride pretreatment in the adhesive procedure increased μTBS significantly. CONCLUSIONS: Tin-chloride pretreatment had a beneficial influence on the bond promoting capacity of the MDP-containing adhesive system Clearfil SE.

Influence of hemostatic agents upon the outcome of periapical surgery: dressings with anesthetic and vasoconstrictor or aluminum chloride

OBJECTIVE To evaluate the effects of different hemostatic agents upon the outcome of periapical surgery. DESIGN A retrospective study was made of patients subjected to periapical surgery between 2006-2009 with the ultrasound technique and using MTA as retrograde filler material. We included patients with a minimum follow-up of 12 months, divided into two groups according to the hemostatic agent used: A) dressings impregnated in anesthetic solution with adrenalin; or B) aluminum chloride paste (Expasyl). Radiological controls were made after 6 and 12 months, and on the last visit. The global evolution scale proposed by von Arx and Kurt (1999) was used to establish the outcome of periapical surgery. RESULTS A total of 96 patients (42 males and 54 females) with a mean age of 40.7 years were included. There were 50 patients in the aluminum chloride group and 46 patients in the anesthetic solution with vasoconstrictor group. No significant differences were observed between the two groups in terms of outcome after 12 months - the success rate being 58.6% and 61.7% in the anesthetic solution with vasoconstrictor and aluminum chloride groups, respectively (p > 0.05). CONCLUSION The outcome after 12 months of follow-up was better in the aluminum chloride group than in the anesthetic solution with vasoconstrictor group, though the difference was not significant.

Chloride channels in myotonia congenita assessed by velocity recovery cycles

Introduction: Myotonia congenita (MC) is caused by congenital defects in the muscle chloride channel CLC-1. This study used muscle velocity recovery cycles (MVRCs) to investigate how membrane function is affected. Methods: MVRCs and responses to repetitive stimulation were compared between 18 patients with genetically confirmed MC (13 recessive, 7 dominant) and 30 age-matched normal controls. Results: MC patients exhibited increased early supernormality, but treatment with sodium channel blockers prevented this. After multiple conditioning stimuli, late supernormality was enhanced in all MC patients, indicating delayed repolarization. These abnormalities were similar between the MC subtypes, but recessive patients showed a greater drop in amplitude during repetitive stimulation. Discussion: MVRCs indicate that chloride conductance only becomes important when muscle fibers are depolarized. The differential responses to repetitive stimulation suggest that in dominant MC the affected chloride channels are activated by strong depolarization, consistent with a positive shift of the CLC-1 activation curve. © 2013 Wiley Periodicals, Inc.

Analysis of polygonal cracking patterns in chloride-bearing terrains on Mars: Indicators of ancient playa settings

The ancient southern highlands on Mars (~3.5 Gyr old) contain > 600 regions that display spectral evidence in the infrared for the presence of chloride-bearing materials. Many of these locations were previously reported to display polygonal cracking patterns. We studied more than 80 of the chloride-bearing terrains using high-resolution (0.25-0.5 m/pixel) images, as well as near-infrared spectral data, to characterize the surface textures and the associated cracking patterns and mineralogies. Our study indicates that ~75% of the studied locations display polygonal cracks that resemble desiccation cracks, while some resemble salt expansion/thrust polygons. Furthermore, we detect, spectrally, the presence of smectites in association with ~30% of the studied fractured terrains. We note that smectites are a special class of swelling clay minerals that can induce formation of large desiccation cracks. As such, we suggest that the cracking patterns are indicative of the presence of smectite phyllosilicates even in the absence of spectral confirmation. Our results suggest that many chloride-bearing terrains have a lacustrine origin and a geologic setting similar to playas on Earth. Such locations would have contained ephemeral lakes that may have undergone repeated cycles of desiccation and recharging by a near-surface fluctuating water table in order to account for the salt-phyllosilicates associations. These results have notable implications for the ancient hydrology of Mars. We propose that the morphologies and sizes of the polygonal cracks can be used as paleoenvironmental, as well as lithological, indicators that could be helpful in planning future missions.