OBJECTIVES: Neurotensin (NT), of which functions are evoked by its interaction with neurotensin receptors (NTR), coexists with mesolimbic dopamine and regulates endogenous dopamine release. Recent studies have shown that NT with NTR exerts neuroleptic-like activity within the central nervous system and may play an important role in the pathogenesis and in the treatment of schizophrenia. We have examined the genetic association between schizophrenia and tetranucleotide repeat polymorphism in the 3'-flanking region of the NTR gene to investigate the possible contribution of the NTR gene to the schizophrenia susceptibility. METHODS: Among 23 alleles identified, the subjects were 120 patients (male 91, female 29) with schizophrenia and 106 normal healthy controls (male 84, female 22). They were unrelated native Korean. PANSS was used to determine positive or negative subgroup in the schizophrenic patients.Using polymerase chain reaction and polyacrylamide gel electrophoresis, tetranucleotide repeat polymorphism (CCTT and CTTT) in the 3'-flanking region of NTR gene was observed. For a comparison of NTR gene's allelic frequencies between patients with schizophrenia and normal healthy controls, chi-square test and Bonferroni's correction was performed. RESULTS: The frequency of A10 allele (base pair size=399) was significantly higher in normal healthy controls than schizophrenia (x2=16.4902, df=1, p<.000). In the comparison between schizophrenic patients with negative symptoms and normal controls, the frequency of A10 allele was significantly higher in normal healthy control subjects than patients with schizophrenia (x2=21.33, df=1, p<0.001). In the case of male, the frequency of A10 allele of schizophrenia was significantly higher than normal controls (x2=13.71, df=1, p<0.001). CONCLUSIONS: NTR gene was negatively associated with schizophrenia. NTR gene's tetranucleotide repeat polymorphism may provide some protective function against schizophrenia.
Alleles ; Central Nervous System ; Dopamine ; Electrophoresis, Polyacrylamide Gel ; Female ; Humans ; Male ; Microsatellite Repeats ; Neurotensin* ; Polymerase Chain Reaction ; Receptors, Neurotensin* ; Schizophrenia*

On reoperations for tissue valve failure from December 1981 to December 1989, we had diagnosed 71 cases as primary tissue failure. In those cases we found out risk factors of accelerated primary tissue failure and increased thrombogenecity. We reviewed also long-term follow-ups of 542 patients after tissue valve replacement from 1978 to 1982, and durability of tissue valve was evaluated with the freedom rate from primary tissue failure. The results were as follows. 1) Eight patients had undergone reoperation by Dec. 1989 ; 71 cases(80.7%) for primary tissue failure, 11 cases(12.5%) for prosthetic valve endocarditis, 4 cases(4.5%) for thromboembolism, and 2 cases(2.3%) for paravalvular leakage. primary tissue failure was the main cause(80.7%) of tissue valve failure. 2) Primary tissue failure occurred at a mean postoperative interval of 89.7 months(range : 19.9-143.2 months). 3)In children under the age of 18, mean implantation time was 62 months, and in adults mean implantation time was 96 months. In the child group primary tissue failure occurred earlier than in the adult group by 34 months(p<0.01) 4) Actuarial freedom from primary tissue failure was 97.6%+/-0.6% at 5 years and 84.4%+/-2.2% at 10 years. 5) The types and locations of prosthetic tissue valves resulted in no significant difference in durability. 6) Primary tissue failure was mainly caused by calcification of the cusps(76%) 7) In atrial fibrillation the incidence of atrial thrombi was 31.3% and left atrial thrombi was the most common finding(60%) In conclusion, 1) Durability of tissue valve for 10 years is acceptable, but the limited durability of tissue may be a major concern after 10 years. 2) In children under the age of 18, tissue valve should be avoided due to accelerated tissue failure. 3) Atrial fibrillation clearly increases the risk of thromboembolism and anticoagulation is considered to be required in patients with atrial fibrillation.
Adult ; Atrial Fibrillation ; Child ; Endocarditis ; Follow-Up Studies ; Freedom ; Humans ; Incidence ; Reoperation ; Risk Factors ; Thromboembolism

An association study with Korean schizophrenic patients(N=75) and normal controls(N=87) was performed to find the relationship between D9S158 polymorphism and schizophrenia using polymerase chain reaction. Eight different alleles of a dinucleotide polymorphism on D9S158 locus were observed in both group. When we compared the frequencies of alleles between schizophrenics and normal controls, there was no significant difference between two groups. To increase homogeneity of schizophrenic group, we divided schizophrenic group by clinical phenotypes such as family history, negative and positive symptoms(PANSS), soft neurologic signs(NES-K) and DSM-lV diagnostic subtypes. Then we compared the frequencies of alleles among subgroups of clinical phenotypes, and there were no significant differences between subgroups(p>.05). Although our findings fail to provide an evidence of association between schizophrenia and D9S158 locus, further investigation of other loci that are linked to NMDA receptor gene may be needed in genetically homogeneous subgroups of schizophrenia.
Alleles ; Chromosomes, Human, Pair 9 ; Humans ; N-Methylaspartate* ; Phenotype ; Polymerase Chain Reaction ; Schizophrenia