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Biomedical subjects

S S Chiou

Publications and source records attributed to S S Chiou.

At least 37 records · Page 2Linked to original sources

Rapid detection of -alpha 4.2 deletion of alpha-thalassemia-2 by polymerase chain reaction.

We sequenced part of the X boxes of alpha-thalassemia-1 of Southeast Asia type (- -SEA) with -alpha 4.2, -alpha 3.7, -alpha G-Taichung, and alpha CS alpha. We found the X box of -alpha 3.7 belonged to the X box of alpha 2 globin gene and the X box of alpha CS alpha contained X boxes of both alpha 1 and alpha 2 globin gene, whereas the X box of -alpha 4.2 and -alpha G-Taichung was a hybrid of X boxes of alpha 2 and alpha 1 globin gene. We also found there are two types of -alpha 4.2 deletion; type 1 is a common type of -alpha 4.2 deletion and type 2 is linkage to -alpha G-Taichung. We used a combination of two methods, the amplification refractory mutation system (ARMS) and the amplified created restriction sites (ACRS), to amplify the hybrids of X boxes specifically. The upstream primer for X box of alpha 2 globin gene was designed following the standard ARMS procedure to amplify the X segment of the alpha-globin gene. The downstream primer was designed according to the ACRS method to check the specificity of PCR products. Using this approach, we can diagnose the different types of -alpha 4.2 deletion. This kind of approach can also be used to amplify the specific region from the cluster of highly homologous genes.

Base Sequence↗

Molecular characterization of glucose-6-phosphate dehydrogenase deficiency in Chinese infants with or without severe neonatal hyperbilirubinaemia.

To characterize mutations in the glucose-6-phosphate dehydrogenase (G6PD) gene in Chinese infants, we studied 213 G6PD-deficient infants without blood exchange transfusion (BET) therapy, and 34 patients who required BET therapy for their severe hyperbilirubinaemia after birth. Nine different point mutations were characterized in all infants. Of these mutations, the G to T substitution at cDNA nucleotide (nt) 1376, which accounts for the mutations in 131 (53.0%) neonates, followed by G to A substitution at nt 1388 in 18 (10.5%) infants, A to G substitution at nt 493 in 17 (6.9%) infants, A to G substitution at nt 95 in 10 (4.1%) infants, C to T substitution at nt 1024 in six (2.4%) infants, and G to T substitution at nt 392 in three (1.2%) infants, G to A substitution at nt 487 in two (0.8%) infants, C to T substitution at nt 1360 in two (0.8%) infants and C to T substitution at nt 592 in two (0.8%) infants. Mutations in 48 (19.5%) G6PD-deficient infants were not characterized. Most (64.7%) mutations in the G6PD-deficient infants who required BET therapy after birth result from a G to T substitution at nt 1376. The enzyme activity of G6PD deficient infants who required BET therapy is significantly lower than for those who did not, even in a group with the same variant (as in 1376 mutation). Severe neonatal jaundice requiring BET therapy can take place with the majority of variants encountered in this area.

Base Sequence↗

Diagnosis of thalassaemia by non-isotope detection of alpha/beta and zeta/alpha mRNA ratios.

The alpha/beta and zeta/alpha messenger RNA (mRNA) ratios in the thalassaemia syndromes were investigated by polymerase chain reaction (PCR) with silver staining of the PCR products. In this study we used the PCR to amplify cDNA copies of circulating erythroid cell mRNA in order to measure the relative amounts of alpha-, beta- and zeta-globin contained within. Quantitation was performed by scanning the silver stain of specific globin cDNA bands. We found that there were significant differences of alpha/beta-mRNA and zeta/alpha-mRNA in patients with Hb H disease and alpha-thalassaemia-1 compared to normal subjects. There was a marked increase in the alpha/beta-mRNA ratio but not in the zeta/alpha-mRNA ratio in patients with beta-thalassaemia. In two beta-thalassaemia cases abnormal increases of zeta-globin bands were noted and they were confirmed through DNA analysis to be combined with alpha-thalassaemia-1. This method provides a simple, rapid and non-radioactive approach to detect thalassaemia syndromes, and can help to screen cases of beta-thalassaemia with alpha-thalassaemia-1.

Adult↗

Molecular basis of beta-thalassemia minor in Taiwan.

The mutations producing beta-thalassemia minor in 227 Taiwanese were studied using the method of naturally and amplified created restriction sites. beta-Thalassemia minor was caused by one beta-globin gene mutation in most of the cases (225/227); only a few cases were caused by two gene mutation (2/227). The most common type of mutation was frameshift codon 41/42 (-TCTT) (93/227), followed in descending order by the C-->T substitution at nucleotide 654 of IVS-2 (83/227), the nonsense mutation A--T at codon 17 (22/227), the A-->T mutation at position -28 of the promotor region (12/227), the frameshift codon 27/28 (+C) (6/227), the initial codon mutation (ATG-->AGG) (5/227), and one each of the codon 71/72 (+A), IVS-1 nt 1 (G-->T), IVS-1 3' end (TAG-->GAG), and nonsense codon 43. In the two cases of the two-gene mutation, one was the nt 654 mutation with Hb Kaohsiung and another one was frameshift codon 41/42 with Hb Meinung. The first four mutations accounted for more than 90% of the mutations. The C-->T substitution at the nt 654 of IVS-2 and initial codon mutation in our study had a higher incidence than in other Southeast Asia areas. Comparison of clinical data in different types of beta-thalassemia showed that there were higher MCV and MCH levels in beta (+)-thalassemia.

Adolescent↗

Sequential invasions of pancreatic pseudocysts in pancreatic tail, hepatic left lobe, caudate lobe, and spleen.

A 66-year-old male patient without a history of risk factors for pancreatitis suffered from pancreatitis and developed pseudocyst. During the course of treatment and follow-up, the pseudocyst was found to have migrated through the pancreatic tail, left hepatic lobe, caudate lobe, and spleen on abdominal sonography and computed tomography scan. Finally, emergent laparotomy was done for splenic abscess and removal of infected pseudocyst in the spleen and lesser sac of the abdomen. The patient made a full recovery after operation.

Aged↗

Molecular basis and haematological characterization of beta-thalassaemia major in Taiwan, with a mutation of IVS-1 3' end TAG-->GAG in a Chinese patient.

We studied 41 patients with beta-thalassaemia major and their parents by using a combination of polymerase chain reaction (PCR) amplification, slot-blot hybridization of allele-specific oligonucleotide (ASO), and direct genomic sequencing. Eight different point mutations were characterized. C to T substitution at nucleotide (nt) 654 of intervening sequences (IVS) 2, accounting for 46.3% of mutant beta-globin genes, is the most common mutation in Taiwan, followed by frameshift codons 41/42 with four nucleotides (TCTT) deletion for 31.7%, A to G substitution at position -28 of promotor area for 8.5%, A to T substitution at codon 17 for 6.1%, frameshift codons 27/28 (insertion of C) for 2.4%, G to T substitution at nucleotide 1 of IVS-1 for 2.4%, frameshift codons 71/72 (insertion of A) and IVS-1 3 end TAG-->GAG for 1.2%. The former four mutations showed no obvious difference between two major ethnic groups in Taiwan. As to mutations in each individual of beta-thalassaemia major, the incidence of compound heterozygotes of two different mutations is much higher than homozygotes of single mutation, 78.0% v 22.0%. Compound heterozygotes of C to T substitution at nt 654 of IVS-2 and frameshift codons 41/42 with four nucleotides deletion is the most common pattern of beta-thalassaemia mutations in each individual (41.5%). The results are somewhat different from other documented reports concerning the mutations of beta-thalassaemia in southern China. This is the first report of mutation of IVS-1 3' end TAG-->GAG which causes consensus change in Chinese people. Patients with heterozygotes of beta zero and -28 beta(+)-thalassaemia mutations would have a greater delay in initial transfusion in comparison to patients with homozygotes of both beta zero-thalassaemia mutation, but their initial clinical manifestation might be aggravated when combined with a glucose-6-phosphate dehydrogenase (G-6-PD) deficiency and an insult such as exposure to infection and certain drugs.

Adolescent↗

Molecular characterization of Hb H disease by polymerase chain reaction.

We utilized the PCR method to amplify the alpha-thalassemia-1 breakpoint area of the Southeast Asia type and several regions of the alpha-globin gene cluster to diagnose rightward deletion (-alpha 3.7), leftward deletion (-alpha 4.2) or nondeletion forms of the Hb H disease. For the nondeletion form, a natural restriction site of MseI was used to detect the Hb Constant Spring (Hb CS) or other termination codon mutations. Another naturally occurring restriction site of MspI was used to detect the Hb Quong-Sze. For the deletion form of the Hb H disease, the differences among nonhomologous I, II and III of the rightward or leftward deletion were used to distinguish the mutations. For further characterization of the subtype of -alpha 3.7 deletion, the same primers for detecting termination codon mutations were used to amplify part of the alpha-globin gene, then the PCR product was digested by the restriction enzyme ApaI. In the 57 cases which were studied, 19 were deletion forms while 38 were nondeletion forms. In the deletion form cases, 13 were rightward deletion (-alpha 3.7) and the other 6 were leftward deletion (-alpha 4.2). However, all of the nondeletion form cases were alpha-thalassemia-1 with Hb CS. After the subtyping of -alpha 3.7 deletion, 11 out of 13 were type I deletions and the other 2 were type II deletions.

Adolescent↗

Prenatal and molecular diagnosis of beta-thalassemia major in Taiwan by naturally and amplified created restriction sites.

To characterize mutations rapidly in 43 patients with beta-thalassemia major in Taiwan, we utilized a method of natural and amplified created restriction site (ACRS) analysis for detection of beta-globin gene mutation. After analysis, eight different point mutations were found among 86 known chromosomes. IVS-2 nt 654 (C-->T), accounting for 40 of the 86 mutations with mutant beta-globin genes, is the most common mutation, followed by frameshift codons 41/42 (-TCTT) in 28 mutations, -28 mutation (A-->G) in 7 mutations, nonsense codon 17 (A-->T) in 5 mutations, frameshift codons 27/28 (insertion of C) in 2 mutations, IVS-1 nt 1 (G-->T) in 2 mutations, frameshift codons 71/72 (insertion of A) in 1 mutation, and IVS-1 3' end TAG-->GAG in 1 mutation. The first four mutations account for 80 of all 86 mutations of beta-thalassemia major in Taiwan. Furthermore, the beta-globin gene mutation was identified successfully in one chorionic villi biopsy for prenatal diagnosis and in specimen of blood from one patient who had received bone marrow transplantation (BMT). Complete diagnosis is possible in all of the Chinese families with beta-thalassemia in Taiwan, and the first trimester prenatal diagnosis can be achieved simply by using only 13 oligonucleotide primers and 10 restriction endonucleases. This non-radioactive assay was shown to be a rapid, sensitive, precise and safe method in detecting the mutations of beta-thalassemia in Taiwan.

Adolescent↗

Rapid diagnosis of beta-thalassemia mutations in Chinese by naturally and amplified created restriction sites.

We developed a rapid and simple method to diagnose the molecular defects of beta-thalassemia in Chinese patients. This method involves the selective amplification of a DNA fragment from human beta globin gene with specific oligonucleotide primers, followed by digestion with restriction enzymes that recognize artificially created or naturally occurring restriction sites. To detect the 4-nucleotide deletion of codon 41-42, we introduced a single mismatch nucleotide into the 3' end of the upstream primer to create an artificial Taq I restriction site. With a similar approach, an artificial Rsa I site was generated to detect the nucleotide 654 mutation (C-->T) of IVS-2, and Alu I restriction site was created to detect the codon 17 mutation (A-->T), and EcoRI restriction site was created for the -28 mutation (A-->G), a Rsa I restriction site was created for the nucleotide 5 mutation (G-->C) of IVS-1, and a Spe I restriction site was created to distinguish the codon 71 (+T) and codon 71/72 (+A) mutations from a normal sequence. The other eight rare mutations that occur in the genes of the Chinese people naturally create or abolish restriction sites. Using this kind of approach, we are able to provide a simple, rapid, accurate, and nonradioactive method to detect the genetic defects of beta-thalassemia in the Chinese population. It should be used not only for routine screening but also for prenatal diagnosis.

Base Sequence↗

Molecular characterization of glucose-6-phosphate dehydrogenase (G6PD) deficiency by natural and amplification created restriction sites: five mutations account for most G6PD deficiency cases in Taiwan.

We have developed a rapid and simple method to diagnose the molecular defects of glucose-6-phosphate dehydrogenase (G6PD) deficiency in Chinese in Taiwan. This method involves the selective amplification of a DNA fragment from human G6PD gene with specific oligonucleotide primers followed by digestion with restriction enzymes that recognize artificially created or naturally occurring restriction sites. Ninety-four Chinese males with G6PD deficiency were studied. The results show that 50% (47 of 94) were G to T mutation at nucleotide (nt) 1376, 21.3% (20 of 94) were G to A mutation at nt 1388, 7.4% (7 of 94) were A to G mutation at nt 493, 7.4% (7 of 94) were A to G mutation at nt 95, 4.2% (4 of 94) were C to T mutation at nt 1024, 1.1% (1 of 94) was G to T mutation at nt 392, and 1.1% (1 of 94) was G to A mutation at nt 487. These results show that the former five mutations account for more than 90% of G6PD deficiency cases in Taiwan. Aside from showing that G to T change at nt 1376 is the most common mutation, our research indicates that nt 493 mutation is a frequent mutation among Chinese in Taiwan. We compared G6PD activity among different mutations, without discovering significant differences between them.

Base Sequence↗

Sonographic detection of stones in poorly opacified left intrahepatic ducts.

Intrahepatic duct (IHD) stone is a common disease in Taiwan. In some cases, left IHD stones cannot be demonstrated by endoscopic retrograde cholangiography (ERC) or even by percutaneous cholangiography (PTC). This study was designed to evaluate the efficacy of sonography in demonstrating left IHD stones in poorly opacified left IHD by either ERC or PTC. Of 109 patients with hyperechoic nodular lesions in either the dilated left IHD or atrophic left lobe of the liver, with or without acoustic shadows, 49 patients were excluded because they refused further study. Among the remainder (60 patients), 33 patients had good opacification of left IHD in ERC or PTC. Stones were seen in 31 patients, and tumor obstruction in 2 patients. Twenty-seven patients had complete or partial absence of the left IHD in cholangiograms. Stones were found at surgery in 23 patients and by CT scan in 3 patients. Mucin-producing cholangiocarcinoma was found in 1 patient. The positive predictive value of the demonstration of stones in left IHD by ultrasound was 95% (57/60). Only 15% of patients with atrophy of the left hepatic lobe and stones were demonstrated by sonogram in this series. We conclude that the detection of left IHD stones by ultrasound in patients with poor opacification of the left IHD in cholangiograms is reliable procedure.

Bile Ducts, Intrahepatic↗

The prognostic factors of severe amebic liver abscess: a retrospective study of 125 cases.

One hundred twenty-five cases of amebic liver abscess were diagnosed at Chang Gung Memorial Hospital in Taiwan from January 1981 to December 1989. An analysis of possible prognostic factors for severe amebic liver abscess was done retrospectively. The majority of the patients came from the southern part of Taiwan. Severe amebic liver abscess was defined as the rupture of an abscess that was resistant to 72 hr of medical treatment, or complicated by secondary bacterial infection. The results showed significant differences between patients with severe liver abscess and those with more moderate forms of amebic liver abscess in indices such as jaundice, hemoglobin and serum bilirubin levels, and dyspnea, as well as in pulmonary changes (right diaphragm elevation, right pleural effusion) seen on chest radiographs. Those patients with diabetes mellitus also had greater evidence of severe liver abscess. Moderate cases that were treated with amebicides showed excellent responses (no mortality). Severe cases required, in addition to amebicide therapy, either percutaneous or surgical drainage of pus, especially in those patients with ruptured abscesses. Those patients with abscesses that ruptured into the thoracic cavity were treated by either thoracostomy or needle aspiration, and all were cured. Three patients died of abscess rupture into the abdominal cavity, associated with secondary bacterial infection. The overall mortality rate was 2.4%. These symptoms and signs of severe liver abscess are indicators of the need for intensive treatment such as aspiration or surgical drainage.

Adult↗

Liver biochemical tests and dengue fever.

The impact of dengue on liver function was studied by biochemical tests on 125 male and 145 female patients diagnosed with this disease during an outbreak that extended from November 1987 to December 1988. Abnormal levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), bilirubin, alkaline phosphatase, and gamma-glutamyl transpeptidase (G-GT) were observed in 93.3%, 82.2%, 7.2%, 16.3% and 83.0% of the patients, respectively. The elevation of transaminases was mild to moderate in most cases, but was 10-fold greater than the normal upper limit for AST and ALT in 11.1% and 7.4% of the patients, respectively. Initially, the level of AST was greater than that of ALT, increasing to maximum levels nine days after the onset of symptoms, then decreasing to normal levels within two weeks. Results of the biochemical tests did not differ significantly between the cases with and without hepatitis B or hepatitis C virus infection, but significantly higher elevations of AST, ALT, and G-GT were observed in patients with episodes of bleeding. Liver biopsies of two patients showed features of lobular hepatitis. Of the five fatal cases, three died of hepatic failure. It is concluded that dengue fever may cause hepatic injury and transaminase elevation similar to that in patients with conventional viral hepatitis. In epidemic or endemic areas, dengue fever infection should be considered in the differential diagnosis of hepatitis.

Adolescent↗

Various sonographic patterns of smooth muscle tumors of the gastrointestinal tract: a comparison with computed tomography.

To evaluate the sonographic patterns of smooth muscle tumors of the gastrointestinal tract, we analyzed 25 patients with histologically confirmed smooth muscle tumors. Sonography revealed no abdominal mass in seven patients (sonogram-negative), and abdominal masses in 18 patients (sonogram-positive). The mean size of tumors in the sonogram-negative group (4.5 +/- 1.5 cm) was smaller than that in the sonogram-positive group (11.4 +/- 3.5 cm). We classified the various sonograms into three patterns. Comparing the sonograms with the computed tomographic pictures of each pattern, we theorized that the different patterns on sonograms may be caused by tumor necroses of different sizes with or without gas in the necrotic cavity. For the necrotic tumors, the size of the necrotic area did not correspond to the size of the tumor. However, the tumors with necroses were significantly larger than those without necroses. A central necrosis was found in cases exhibiting both leiomyosarcoma and leiomyoma. On comparing the sonogram-positive and sonogram-negative groups, we found that the size and location of a tumor may affect the detection rate of that tumor by sonography.

Adult↗

Modulation of the membrane surrounding particulate cement and polyethylene in the rabbit tibia.

Twenty-nine mature New Zealand white, female rabbits were divided into four groups. Using sterile technique, a 6 mm drill hole was made in the tibia 1 cm distal to the knee joint. The marrow was scooped out underneath the hole. The right tibia received Simplex particulate cement polymer (PMMA) (groups 1 and 2) or polyethylene particles (UHMWP) (groups 3 and 4). The left leg functioned as a prepared but non-implanted control. All animals were fed a standard diet; those in groups 1 and 3 received plain water, while groups 2 and 4 drank water in which sodium naproxen was dissolved (1.375 mg/ml). Animals were killed after 16 wk. The implant area was harvested and grown in tissue culture. The cumulative collection of tissue culture supernatants over 3 d was assayed for prostaglandin E2 (PGE2) via radioimmunoassay. PGE2 production was significantly higher in the membrane harvested from the right side containing particulate cement with no sodium naproxen (group 1) compared with controls (P less than 0.05). The ratio of PGE2 values for the right divided by the left side yielded higher values in group 1, compared with groups 2, 3 or 4 (P less than 0.01). Previous studies have suggested that particulate debris and PGE2 production are associated with arthroplasty loosening. This experiment has demonstrated that PGE2 production by the membrane surrounding particulate debris can be suppressed by the administration of oral sodium naproxen. Because non-steroidal anti-inflammatory drugs are known to inhibit prostaglandin synthesis in man, these agents may prove useful in retarding the bone loss associated with early prosthetic loosening.

Animals↗

Suppression of prostaglandin E2 synthesis in the membrane surrounding particulate polymethylmethacrylate in the rabbit tibia.

Fifteen mature, New Zealand, female rabbits were divided into two groups. Using sterile technique, a 6-mm drill hole was made in the tibia 1 cm distal to the knee joint bilaterally. The marrow was scooped out underneath the hole. The right tibia received Simplex particulate cement polymer and the left leg functioned as a prepared, but nonimplanted, control. All animals were fed a standard diet. Whereas the six animals in Group 1 received regular water, the nine animals in Group 2 drank water in which sodium naproxen was dissolved (1.375 mg per ml). The animals were killed after 16 weeks. The implant area was harvested under sterile conditions and maintained in tissue culture. The cumulative collection of tissue culture supernatants over a three-day period was assayed for Prostaglandin E2 (PGE2) via radioimmunoassay. Specimens from Group 1 produced an average of 106.0 +/- 10.9 ng PGE2 on the right side, and 35.3 +/- 6.0 ng PGE2 on the left side. Specimens from Group 2 produced an average of 31.1 +/- 6.1 ng PGE2 on the right experimental side and 26.0 +/- 5.1 ng PGE2 on the left control side. The ratio of PGE2 values for the right divided by the left side yielded higher values in Group 1, compared to Group 2. Cement polymer particles have been shown to produce a florid foreign body histologic reaction similar to that associated with prosthetic loosening in man. This experiment has demonstrated that the increased PGE2 production by the membrane surrounding particulate cement polymer can be suppressed by the administration of an oral cyclo-oxygenase inhibitor. PGE2 has been previously shown to induce bone resorption in vivo and in vitro. The use of nonsteroidal antiinflammatory drugs may be indicated in retarding the bone loss associated with early prosthetic loosening.

Animals↗