In order to study the altered molecular events during laryngeal carcinogenesis and elucidate the role of Haras oncogene amplification and mutation. we have examined their profile by polymerase chain reaction (PCR) and...In order to study the altered molecular events during laryngeal carcinogenesis and elucidate the role of Haras oncogene amplification and mutation. we have examined their profile by polymerase chain reaction (PCR) and selective oligonucleotide hybridization. We analyzed the mutational status of codon 12 of Haras in 22 laryngeal carcinomas and 10 normal tissues. and found that 7 of 22 laryngeal carcinomas contained a Ha-ras mutation at codon 12. The frequency of mutation was 32%. None of the normal tissues revealed mutation. Moreover. no amplification was found in cancers when compared to the normal. Ourfindings indicated that the activated Ha-ras gene existed in laryngeal carcinoma. and activation of the Haras gene by mutation at codon 12 might play a key role in laryngeal carcinogenesis.展开更多
BACKGROUND:Cerebral venous thrombosis(CVT) is a rare disease and it has different etiologies.Inherited or acquired prothrombotic state plays a key role in the development of CVT.METHODS:A 28-year-old man who presented...BACKGROUND:Cerebral venous thrombosis(CVT) is a rare disease and it has different etiologies.Inherited or acquired prothrombotic state plays a key role in the development of CVT.METHODS:A 28-year-old man who presented to our emergency department with persistent headache and accompanied by complaints of nausea and vomiting over a week.Neurologic examination revealed bilateral papilledema.Brain computed tomography showed a hyperdense area on the posterior part of the occipital lobe.Brain magnetic resonance imaging and magnetic resonance venography revealed thrombosis of CVT.Homozygous mutations were found for methylenetetrahydrofolate reductase(MTHFR).MTHFR CG677 T gene mutation and blood tests showed elevated homocysteine levels on the etiological screening.There was no other etiology for CVT.RESULTS:Headache and other complaints were improved after treatment of heparin,warfarin,and vitamin B12.No recurrence of symptoms was observed upon outpatient follow-up.CONCLUSION:Since CVT is an important cause of headache,we recommend etiology screening for patients who present with CVT for MTHFR gene mutations and family counseling should be provided.展开更多
Objective. To identify and evaluate mutations in the RPl gene among Chinese patients with retinitis pigmen-tosa (RP).Methods. Leukocyte DNA of 92 RP patients were collected in Hong Kong. Sequence changes of the entire...Objective. To identify and evaluate mutations in the RPl gene among Chinese patients with retinitis pigmen-tosa (RP).Methods. Leukocyte DNA of 92 RP patients were collected in Hong Kong. Sequence changes of the entire coding region of the RP1 gene were examined using PCR, conformation sensitive gel electrophoresis and DNA sequencing.Results. In total, 1 nonsense mutation and 1 nonsense variant as well as 10 missense alterations were identified in the RP1 gene, among which, Arg677Ter was found in 1 RP patient and another nonsense variant, Argl933Ter, was identified in 3 normal individuals and 1 patient with Stargardt' s disease, suggesting its nonpathogenicity. Arg677Ter is expected to lead to large disruptions of the encoded protein.Conclusions. The nonpathogenicity of Argl933Ter indicates that the C - terminal 224 residues of RPl protein may be not critical for RP1. The most C - terminal truncation previously reported was due to Tyr1053 (1 -bp del) and occurred in RP patients. Thus RP can be caused by reduction in the level of the region of RPl protein after codon 1052 but before 1933. To ascertain such a proposition, genotypes of more RP patients may reveal more RP causative mutations and more sequence alterations different than those of other ethnic groups.展开更多
Objective To study the clinical and genetic features of familiar amyloid polyneuropathy (FAP). Methods Three families of suspected FAP in China mainland and Macao were investigated on aspects of clinical manifestation...Objective To study the clinical and genetic features of familiar amyloid polyneuropathy (FAP). Methods Three families of suspected FAP in China mainland and Macao were investigated on aspects of clinical manifestations, histological features, and gene analysis. Results All the 3 families had the clinical features of sensory and motor polyneuropathies, and notable vegetative nerve involvements. Affected cases of one family had ultrasound proved cardiomyopathy. Histological studies showed amyloid deposition in all the biopsy tissues of the affected cases of the 3 families, and anti-transthyretin antisera staining was positive in 3 cases of one family. Gene analysis confirmed that mutation types were amyloidogenic transthyretin (ATTR) Val30Met, Phe33Val, and Gly67Glu in the 3 families respectively. The ATTR Gly67Glu family had a shorter survival time due to the heart involvement compared with the other 2 families. Conclusion FAP is an autosomal dominant inherited disease, with its clinical manifestations related to the type of genetic mutation.展开更多
Glycidyl methacrylate (GMA)is a recently recognized mutagen. In order to explore the mutagenicity and mechanism of GMA, plasmid PBR322 was used for in vitro binding, mutant screening, restriction enzyme mapping,and DN...Glycidyl methacrylate (GMA)is a recently recognized mutagen. In order to explore the mutagenicity and mechanism of GMA, plasmid PBR322 was used for in vitro binding, mutant screening, restriction enzyme mapping,and DNA sequencing. To explore the mechamism by which an initial premutational event is converted into a stable heritable mutation, pBR322 and GMA-bound pBR322 were transformed into E. coli HB101 , and the following results were obtained : 1) GMA-bound PBR322 induced phenotype changes in competent cells. Two stable and heritable mutants were isolated (Ap￣RTc￣S and Ap￣STc￣R). 2) When restriction enzyme mapping was used to analyze the mutant Ap￣RTc￣S , four of seven maps showed changes, but no large DNA insertion or deletion were observed.3) The frequency of deletion and insertion forms counted about 10%. Sequence specificity and hot spot regions were evident in the sequence analysis of mutated plasmid. The above results indicate that the premutagenic lesions of plasmid induced by GMA can be converted into point mutations in vivo.展开更多
Cardiomyopathies are diseases that primarily affect the myocardium, leading to serious cardiac dysfunction and heart failure. Out of the three major categories of cardiomyopathies （hypertrophic, dilated and restrict...Cardiomyopathies are diseases that primarily affect the myocardium, leading to serious cardiac dysfunction and heart failure. Out of the three major categories of cardiomyopathies （hypertrophic, dilated and restrictive）, restrictive cardiomyopathy （RCM） is less common and also the least studied. However, the prognosis for RCM is poor as some patients dying in their childhood. The molecular mechanisms behind the disease development and progression are not very clear and the treatment of RCM is very difficult and often ineffective. In this article, we reviewed the recent progress in RCM research from the clinical studies and the translational studies done on diseased transgenic animal models. This will help for a better understanding of the mechanisms underlying the etiology and development of RCM and for the design of better treatments for the disease.展开更多
Objective To investigate the clinical and genetic features of a Chinese family with yon Hippel- Lindau （VHL） disease revealed by bilateral pheochromocytoma. Methods The proband and other members in a Chinese family...Objective To investigate the clinical and genetic features of a Chinese family with yon Hippel- Lindau （VHL） disease revealed by bilateral pheochromocytoma. Methods The proband and other members in a Chinese family with familial pheochromocytoma were clinically evaluated and followed up. Genomic DNA extracted from the peripheral blood of 8 family members （including 3 patients） was amplified by polymerase chain reaction （PCR） and the PCR products were directly sequenced. Results The first presentation in the proband, his mother, and his sister was bilateral pheochromocytoma, and the missense mutation of 695G-A （Arg161Gln） in exon 3 of VHL gene was detected in the three patients. In the follow-up study, the proband and his mother were found to have other VHL tumors, induding retinal and cerebellar hemangioblastomas and pancreatic tumor. Neither clinical presentation of VHL disease nor gene mutation was found in other family members. Conclusion VHL disease should be suspected in some patients with familial pheochromocytoma, and VHL gene screening helps to achieve early diagnosis of the disease.展开更多
Objective To characterize early afterdepolarizations （EADs） caused triggered activity （TA） among calsequestrin-2 （CASQ2） knock-in （CASQ2 KI） mice and its relationship with aging. Methods Electrophysiological p...Objective To characterize early afterdepolarizations （EADs） caused triggered activity （TA） among calsequestrin-2 （CASQ2） knock-in （CASQ2 KI） mice and its relationship with aging. Methods Electrophysiological properties of ventricular myocytes from 3- month （mo, young）, 9-mo （adult-l） and 12-too （adult-2） in wild-type （WT） and CASQ2 KI mice were investigated with patch-clamp technique. Results The incidences of EADs and TA in CASQ2 KI cardiomyocytes increased with increasing age. In contrast, WT mice cardiomyocytes showed no significant change in matched-age groups. Compared with that in 3-mo CASQ2 KI mice, the 50% repolarization of action potential （APD50） showed prolongation in both 9-mo and 12-mo ones （9.2±0.9 ms of 9-mo and 10.3 ± 1.2 ms of 12- mo vs. 5.6± 0.3 ms of 3-mo）, while the 90 % repolarization of action potential （APD90） was similar among 3 age groups. Compared with 3-mo mice, the 9-mo and 12-mo CASQ2 KI mice showed markedly reduced transient outward potassium current （Ito） densities but increased L-type calcium current （ICa-L） densities. Conlcusion This study suggested that events of EADs and TA in CASQ2 KI mice increased with increasing age, It might be associated partly with the augment of cellular calcium concentration and the prolongation of APD50 induced by decrease of Ito and increase of ICa-L in adult CASQ2 KI mice展开更多
Coarctation of the aorta(CoA)refers to the congenital coarctation near the isthmus,ductus arteriosus or ligamentum arteriosus,with an incidence of 5%–10%in children with congenital heart defects.[1]It can be isolated...Coarctation of the aorta(CoA)refers to the congenital coarctation near the isthmus,ductus arteriosus or ligamentum arteriosus,with an incidence of 5%–10%in children with congenital heart defects.[1]It can be isolated or coexisted with ventricular septal defects,subaortic stenosis,patent ductus arteriosus,and mitral aortic valve.[2]CoA has a poor prognosis.Without intervention,the median age of death with aortic coarctation is 38 years[3]and 75%death of those patients is at the age of 46 years.[4]Causes of death included congestive heart failure(26%),aortic rupture(21%),bacterial endocarditis(18%),and intracranial hemorrhage(12%).[5]Therefore,early diagnosis and optimal treatment are the key to improve the prognosis of this disease.The aim of this report is underlining the importance of early and accurate diagnose of CoA as a cause of systemic hypertension in young patients and also emphasizing the genetic factors of CoA in twins.展开更多
Objective. In order to investigate 5,10-methylenetetrahydrofolate reductase (MTHFR)s polymorphic changes in psoriasis vulgaris. Methods.We detected mutation of site C677V of MTHFR in 39 psoriastics by PCR-RFLP. Result...Objective. In order to investigate 5,10-methylenetetrahydrofolate reductase (MTHFR)s polymorphic changes in psoriasis vulgaris. Methods.We detected mutation of site C677V of MTHFR in 39 psoriastics by PCR-RFLP. Results.Genotype frequencies of the psoriastics were C/C=20.15%,C/T=48.72% and T/T= 30.77%; the allelic frequencies were C=0.4487 and T=0.5513. Homozygous mutant (TT) of the psoriastics was significantly different from the normal control group by X2 test. Conclusion.C677V mutant of MTHFR might be related with psoriasis.展开更多
文摘In order to study the altered molecular events during laryngeal carcinogenesis and elucidate the role of Haras oncogene amplification and mutation. we have examined their profile by polymerase chain reaction (PCR) and selective oligonucleotide hybridization. We analyzed the mutational status of codon 12 of Haras in 22 laryngeal carcinomas and 10 normal tissues. and found that 7 of 22 laryngeal carcinomas contained a Ha-ras mutation at codon 12. The frequency of mutation was 32%. None of the normal tissues revealed mutation. Moreover. no amplification was found in cancers when compared to the normal. Ourfindings indicated that the activated Ha-ras gene existed in laryngeal carcinoma. and activation of the Haras gene by mutation at codon 12 might play a key role in laryngeal carcinogenesis.
文摘BACKGROUND:Cerebral venous thrombosis(CVT) is a rare disease and it has different etiologies.Inherited or acquired prothrombotic state plays a key role in the development of CVT.METHODS:A 28-year-old man who presented to our emergency department with persistent headache and accompanied by complaints of nausea and vomiting over a week.Neurologic examination revealed bilateral papilledema.Brain computed tomography showed a hyperdense area on the posterior part of the occipital lobe.Brain magnetic resonance imaging and magnetic resonance venography revealed thrombosis of CVT.Homozygous mutations were found for methylenetetrahydrofolate reductase(MTHFR).MTHFR CG677 T gene mutation and blood tests showed elevated homocysteine levels on the etiological screening.There was no other etiology for CVT.RESULTS:Headache and other complaints were improved after treatment of heparin,warfarin,and vitamin B12.No recurrence of symptoms was observed upon outpatient follow-up.CONCLUSION:Since CVT is an important cause of headache,we recommend etiology screening for patients who present with CVT for MTHFR gene mutations and family counseling should be provided.
文摘Objective. To identify and evaluate mutations in the RPl gene among Chinese patients with retinitis pigmen-tosa (RP).Methods. Leukocyte DNA of 92 RP patients were collected in Hong Kong. Sequence changes of the entire coding region of the RP1 gene were examined using PCR, conformation sensitive gel electrophoresis and DNA sequencing.Results. In total, 1 nonsense mutation and 1 nonsense variant as well as 10 missense alterations were identified in the RP1 gene, among which, Arg677Ter was found in 1 RP patient and another nonsense variant, Argl933Ter, was identified in 3 normal individuals and 1 patient with Stargardt' s disease, suggesting its nonpathogenicity. Arg677Ter is expected to lead to large disruptions of the encoded protein.Conclusions. The nonpathogenicity of Argl933Ter indicates that the C - terminal 224 residues of RPl protein may be not critical for RP1. The most C - terminal truncation previously reported was due to Tyr1053 (1 -bp del) and occurred in RP patients. Thus RP can be caused by reduction in the level of the region of RPl protein after codon 1052 but before 1933. To ascertain such a proposition, genotypes of more RP patients may reveal more RP causative mutations and more sequence alterations different than those of other ethnic groups.
文摘Objective To study the clinical and genetic features of familiar amyloid polyneuropathy (FAP). Methods Three families of suspected FAP in China mainland and Macao were investigated on aspects of clinical manifestations, histological features, and gene analysis. Results All the 3 families had the clinical features of sensory and motor polyneuropathies, and notable vegetative nerve involvements. Affected cases of one family had ultrasound proved cardiomyopathy. Histological studies showed amyloid deposition in all the biopsy tissues of the affected cases of the 3 families, and anti-transthyretin antisera staining was positive in 3 cases of one family. Gene analysis confirmed that mutation types were amyloidogenic transthyretin (ATTR) Val30Met, Phe33Val, and Gly67Glu in the 3 families respectively. The ATTR Gly67Glu family had a shorter survival time due to the heart involvement compared with the other 2 families. Conclusion FAP is an autosomal dominant inherited disease, with its clinical manifestations related to the type of genetic mutation.
文摘Glycidyl methacrylate (GMA)is a recently recognized mutagen. In order to explore the mutagenicity and mechanism of GMA, plasmid PBR322 was used for in vitro binding, mutant screening, restriction enzyme mapping,and DNA sequencing. To explore the mechamism by which an initial premutational event is converted into a stable heritable mutation, pBR322 and GMA-bound pBR322 were transformed into E. coli HB101 , and the following results were obtained : 1) GMA-bound PBR322 induced phenotype changes in competent cells. Two stable and heritable mutants were isolated (Ap￣RTc￣S and Ap￣STc￣R). 2) When restriction enzyme mapping was used to analyze the mutant Ap￣RTc￣S , four of seven maps showed changes, but no large DNA insertion or deletion were observed.3) The frequency of deletion and insertion forms counted about 10%. Sequence specificity and hot spot regions were evident in the sequence analysis of mutated plasmid. The above results indicate that the premutagenic lesions of plasmid induced by GMA can be converted into point mutations in vivo.
文摘Cardiomyopathies are diseases that primarily affect the myocardium, leading to serious cardiac dysfunction and heart failure. Out of the three major categories of cardiomyopathies （hypertrophic, dilated and restrictive）, restrictive cardiomyopathy （RCM） is less common and also the least studied. However, the prognosis for RCM is poor as some patients dying in their childhood. The molecular mechanisms behind the disease development and progression are not very clear and the treatment of RCM is very difficult and often ineffective. In this article, we reviewed the recent progress in RCM research from the clinical studies and the translational studies done on diseased transgenic animal models. This will help for a better understanding of the mechanisms underlying the etiology and development of RCM and for the design of better treatments for the disease.
基金Supported by the "tenth five-years " National Science and Technology Tackle Key Project (2004BA720A29)
文摘Objective To investigate the clinical and genetic features of a Chinese family with yon Hippel- Lindau （VHL） disease revealed by bilateral pheochromocytoma. Methods The proband and other members in a Chinese family with familial pheochromocytoma were clinically evaluated and followed up. Genomic DNA extracted from the peripheral blood of 8 family members （including 3 patients） was amplified by polymerase chain reaction （PCR） and the PCR products were directly sequenced. Results The first presentation in the proband, his mother, and his sister was bilateral pheochromocytoma, and the missense mutation of 695G-A （Arg161Gln） in exon 3 of VHL gene was detected in the three patients. In the follow-up study, the proband and his mother were found to have other VHL tumors, induding retinal and cerebellar hemangioblastomas and pancreatic tumor. Neither clinical presentation of VHL disease nor gene mutation was found in other family members. Conclusion VHL disease should be suspected in some patients with familial pheochromocytoma, and VHL gene screening helps to achieve early diagnosis of the disease.
文摘Objective To characterize early afterdepolarizations （EADs） caused triggered activity （TA） among calsequestrin-2 （CASQ2） knock-in （CASQ2 KI） mice and its relationship with aging. Methods Electrophysiological properties of ventricular myocytes from 3- month （mo, young）, 9-mo （adult-l） and 12-too （adult-2） in wild-type （WT） and CASQ2 KI mice were investigated with patch-clamp technique. Results The incidences of EADs and TA in CASQ2 KI cardiomyocytes increased with increasing age. In contrast, WT mice cardiomyocytes showed no significant change in matched-age groups. Compared with that in 3-mo CASQ2 KI mice, the 50% repolarization of action potential （APD50） showed prolongation in both 9-mo and 12-mo ones （9.2±0.9 ms of 9-mo and 10.3 ± 1.2 ms of 12- mo vs. 5.6± 0.3 ms of 3-mo）, while the 90 % repolarization of action potential （APD90） was similar among 3 age groups. Compared with 3-mo mice, the 9-mo and 12-mo CASQ2 KI mice showed markedly reduced transient outward potassium current （Ito） densities but increased L-type calcium current （ICa-L） densities. Conlcusion This study suggested that events of EADs and TA in CASQ2 KI mice increased with increasing age, It might be associated partly with the augment of cellular calcium concentration and the prolongation of APD50 induced by decrease of Ito and increase of ICa-L in adult CASQ2 KI mice
文摘Coarctation of the aorta(CoA)refers to the congenital coarctation near the isthmus,ductus arteriosus or ligamentum arteriosus,with an incidence of 5%–10%in children with congenital heart defects.[1]It can be isolated or coexisted with ventricular septal defects,subaortic stenosis,patent ductus arteriosus,and mitral aortic valve.[2]CoA has a poor prognosis.Without intervention,the median age of death with aortic coarctation is 38 years[3]and 75%death of those patients is at the age of 46 years.[4]Causes of death included congestive heart failure(26%),aortic rupture(21%),bacterial endocarditis(18%),and intracranial hemorrhage(12%).[5]Therefore,early diagnosis and optimal treatment are the key to improve the prognosis of this disease.The aim of this report is underlining the importance of early and accurate diagnose of CoA as a cause of systemic hypertension in young patients and also emphasizing the genetic factors of CoA in twins.
文摘Objective. In order to investigate 5,10-methylenetetrahydrofolate reductase (MTHFR)s polymorphic changes in psoriasis vulgaris. Methods.We detected mutation of site C677V of MTHFR in 39 psoriastics by PCR-RFLP. Results.Genotype frequencies of the psoriastics were C/C=20.15%,C/T=48.72% and T/T= 30.77%; the allelic frequencies were C=0.4487 and T=0.5513. Homozygous mutant (TT) of the psoriastics was significantly different from the normal control group by X2 test. Conclusion.C677V mutant of MTHFR might be related with psoriasis.
