This article reported two cases of congenital myotonic dystrophy. Case 1 was a premature infant born at 35 weeks of gestation, with severe asphyxia as the initial manifestation. After admission, the infant had limited spontaneous activity, low muscle tone, weak spontaneous respiration, inability to swallow independently, and bilateral talipes equinovarus. The initial diagnosis was neonatal hypoxic-ischemic encephalopathy. However, clinical observation suggested the possibility of other diseases and genetic testing indicated that the number of CTG trinucleotide repeats in the DMPK gene was>150 times, suggesting a high possibility that the child's mother was also affected, but remained undiagnosed due to lack of testing. Case 2 was a full-term infant born at 37 weeks and 1 day of gestation, who presented with asphyxia and dyspnea initially. It also presented with limited spontaneous activity, low muscle tone, weak respiration, and bilateral talipes equinovarus, which was highly similar to the clinical situation of Case 1. The genes of the child and his mother were tested, and the results showed that the number of CTG trinucleotide repeats in the DMPK gene was >150 times for both. Both children died within a few hours after being discharged from the hospital due to the family's decision to abandon treatment.

This article reported two cases of congenital myotonic dystrophy. Case 1 was a premature infant born at 35 weeks of gestation, with severe asphyxia as the initial manifestation. After admission, the infant had limited spontaneous activity, low muscle tone, weak spontaneous respiration, inability to swallow independently, and bilateral talipes equinovarus. The initial diagnosis was neonatal hypoxic-ischemic encephalopathy. However, clinical observation suggested the possibility of other diseases and genetic testing indicated that the number of CTG trinucleotide repeats in the DMPK gene was>150 times, suggesting a high possibility that the child's mother was also affected, but remained undiagnosed due to lack of testing. Case 2 was a full-term infant born at 37 weeks and 1 day of gestation, who presented with asphyxia and dyspnea initially. It also presented with limited spontaneous activity, low muscle tone, weak respiration, and bilateral talipes equinovarus, which was highly similar to the clinical situation of Case 1. The genes of the child and his mother were tested, and the results showed that the number of CTG trinucleotide repeats in the DMPK gene was >150 times for both. Both children died within a few hours after being discharged from the hospital due to the family's decision to abandon treatment.

An optimized two-dimensional polyacrylamide gel electrophoresis (2-DE) system for analyzing plant proteins was developed by evaluating different reagents and concentrations used in the sample extraction solutions and lysis buffers. Two main sample preparation methods, referred to as trichloroacetic acid (TCA)-acetone method and phenol extraction-ammonium acetate/methanol (phenol-NH4Ac/methanol) precipitation method, were compared. Four ecotypes of reed plants (Phragmites communis Trin.) from the desert region of north-western China were used as experimental materials: (1) swamp reed (SR) which grows in water about 1 m deep; (2) dune reed (DR) which grows on 5～10 m high sand dunes; (3) heavy salt meadow reed (HSMR) which grows on low-lying salt flats; and (4) light salt meadow reed (LSMR) which grows in the transition area between DR and HSMR growing areas. The optimized phenol-NH4Ac/methanol precipitation method consisted of extracting leaf proteins of different ecotypes of reed with water-saturated phenol and then precipitating with a 5-fold volume of 0.1 mol/L NH4Ac in methanol, followed by dissolving in the lysis buffer. The optimized protein lysis buffer consisted of 7 mol/L urea, 2 mol/L thiourea, 4% CHAPS, 2% Ampholine(pH 3.5～10∶pH 5～8 = 1∶4) and 65 mmol/L DTT. The prepared protein sample (80 ?g) was then separated by 2-DE gel and detected by silver staining method. This improved 2-DE system resulted in a 2-D protein profile of higher resolution and higher protein yields as analyzed by PDQuest software. Good results were also obtained when this 2-DE system was used in 2-D analysis of proteins from other plant materials, such as rice leaves, indicating that it is a suitable 2-DE system for analyzing leaf proteins of different plant species.