Objective To explore experimental evidence for prevention and treatment of low temperature burns in clinical practice.Methods A rat model of low temperature burns was established by exposing abdominal skin to temperature of 42 ～ 70 ℃.Time needed to cause burns,severity of damage,pathological changes,relation between tissue damage and temperature and mortality of animal models were studied.Results We found that skin tissue was not different between the 42 ℃ rats and normal temperature rats.45.2％ rats died in 2-3 h after exposed to 45 ℃.All rats died in 45-60 min after exposed to 50 ℃.Death time was(42.43 ±2.15)min in rats directly exposed to 55 ℃,and(66.14 ±8.61)min in rats with protection,and the difference was significant(t =7.0697,P ＜ 0.01).Microscopy revealed that wide necrosis in rats skin,subcutaneous tissue and deep muscular layer.Conclusions Low temperature burns are caused by direct exposure to temperature of 45 ～ 70 ℃ while high temperature bums are caused by direct exposure to temperature of 70 ℃ and above.Severity of damage and mortality is related to temperature,exposure time and position.

OBJECTIVEMutation screening was performed to a Chinese family with hypokalaemic periodic paraiysis(HOKPP) for locating the corresponding mutations of gene and for specifying the clinical features associated with mutations.

METHODSThe cilnical features of patients from HOKPP family were summurized. Techniques of target exon PCR and direct sequencing were used to screen the mutation in CACNA1S and SCN4A genes in all numbers of the family.

RESULTSTwo patients of the family showed the typical features of HOKPP: the age of disease onset is during the childhood, acetazolamide is effective to patients treated. A heterozygous point mutation 3716 (G>A) causing R1239H was found in exon 30 of CACNA1S gene of the patients, but not found in normal members of the family.

CONCLUSIONThe mutant R1239H in CACNA1S gene exists in Chinese patients with familial hypokalaemic periodic paralysis.

Adolescent ; Adult ; Base Sequence ; Calcium Channels ; genetics ; China ; DNA Mutational Analysis ; Family Health ; Female ; Humans ; Hypokalemic Periodic Paralysis ; genetics ; Male ; Mutation ; Pedigree ; Polymerase Chain Reaction