Molecular diagnosis of Apert syndrome in Chinese patients

Apert syndrome is a clinically distinct condition characterized by craniosynostosis and severe syndactyly of the hands and the feet. Apert syndrome results from either of two specific nucleotide substitutions, both C-to-G transversions, in the fibroblast growth factor receptor 2 (FGFR2) gene. To determine if Chinese Apert syndrome patients carry the same mutations, fifteen unrelated Apert syndrome patients and a fetus from a mother with Apert syndrome were studied by the use of restriction analysis and direct sequencing. The results demonstrated that 13 had the Ser252Trp mutation and 2 had the Pro253Arg mutation. Prenatal diagnosis of the fetus was successfully made.

Molecular diagnosis of patients with beta-thalassemia major in central Taiwan by amplified created restriction site analysis

beta-Thalassemia, a hematologic disorder characterized by the deficiency or the absence of beta-globin production, is the most widespread inherited disorder in the world; it is also common in Taiwan. We studied 38 patients in central Taiwan with beta-thalassemia major, using amplified created restriction site analysis for detection. On analysis, six different point mutations were found among 76 chromosomes, of which 32 chromosomes (42.1%) had a C to T substitution at nucleotide 654, 30 (40%) had frameshift codons 41/42 with four nucleotides (TCTT) deletion, 7 (9.2%) had an A to T substitution at codon 17, 3 (3.9%) had frameshift codons 71/72 (insertion of A), 2 (2.6%) had an A to G substitution at position -28, and 2 (2.6%) had frame-shift codons 27/28 (insertion of C). The first two mutations accounted for 62 of the 76 beta-thalassemia mutations in this study. As to mutations in each individual with beta-thalassemia major, the incidence of compound heterozygotes of two different mutations was higher than that of homozygotes of a single mutation (60% vs 40%). Compound heterozygotes of C to T substitution at nucleotide 654 of IVS-2 and frameshift codons 41/42 with four-nucleotide deletion was the most common pattern of beta-thalassemia mutations in each individual (23.7%). Our results were unique compared with those from similar studies performed in southern China. Frequencies of beta-thalassemia mutations found in the current study were assessed and compared with frequencies found in previous studies conducted in northern and southern Taiwan.

Video-assisted endoscopic saphenous vein harvesting for coronary artery bypass grafting

Saphenous vein grafts for coronary artery bypass can be harvested by means of the traditional long incision method, the skin bridge method, or a newly developed endoscopic technique. We applied the endoscopic technique to reduce the length of leg incision and to decrease the frequency of complications. Between September and December 1996, 47 patients underwent coronary artery bypass grafts, 17 of whom volunteered to undergo saphenous vein harvest with the Endopath video-assisted endoscopic saphenous vein harvest (ESVH) system; the other 30 patients underwent the traditional long incision harvest procedure. A total of 22 saphenous veins were harvested from the 17 patients who underwent ESVH. The mean length of the leg wound was 5.8 +/- 1.3 cm and the mean length of the vein harvested was 32.9 +/- 3.4 cm (wound/vein length ratio 17.6%). The wound/vein length ratio of the 30 patients who underwent the traditional open harvest method was 91.5% (30.8 +/- 2.2 cm/34.1 +/- 3.0 cm). ESVH failed and was converted to the conventional method in two cases. The mean time required to harvest the saphenous vein was 72.7 +/- 20.8 minutes in the ESVH group and 45.8 +/- 12.5 minutes in the open surgery group. No wound complications were noted in the ESVH group, except for ecchymosis in three cases. Five patients in the open surgery group had wound discharge (17%). The length of hospital stay was shorter (10.5 +/- 2.6 days vs 15.8 +/- 4.2 days) and fewer analgesics were used in the ESVH group. The rate of cardiac complications was not different between the two groups. Examination of the vein graft under light microscopy also did not reveal any differences. We conclude that the endoscopic technique can provide adequate vein grafts for use in coronary artery bypass grafting and reduce the leg wound complication rate, hospital stay, and use of analgesics.

Opioid receptor independent effects of morphine on membrane currents in single cardiac myocytes

We have examined the effects of morphine, a mu-opioid receptor agonist, on various membrane ionic currents in rat ventricular and human atrial myocytes, using patch-clamp techniques in the whole-cell configuration. Morphine produced a concentration-dependent reduction in peak transient sodium current. When the sodium current (INa) was evoked at 5-s intervals the estimated IC50 for morphine was approximately 30 mumol litre-1. Morphine 10 mumol litre-1 inhibited INa with a 5-mV shift in the potential-dependent inactivation curve to negative potentials and retarded the INa recovery rate from the inactivated state. Use-dependent INa block was not observed when INa was elicited at frequencies varying from 0.2 to 20 Hz. Morphine did not significantly affect the inward calcium current (ICa), transient outward current (Ito) or the inwardly rectifying potassium current (IK1) at a concentration of 30 mumol litre-1. The inhibitory effect of morphine on INa could not be prevented or reversed by treatment with the opioid antagonist naloxone. Therefore, we suggest that morphine can directly inhibit the Na+ inward current and bind to inactivated Na+ channels.

Identification and characterization of the Escherichia coli-expressed RNA-dependent RNA polymerase of bamboo mosaic virus

Bamboo mosaic virus (BaMV), a member of the potexvirus group, infects primarily members of the Bambusoideae. The open reading frame 1 (ORF1) of BaMV encodes a 155-kDa polypeptide that was postulated to be involved in the replication and the formation of cap structure at the 5' end of the viral genome. To characterize the activities associated with the 155-kDa viral protein, it was expressed in Escherichia coli BL21(DE3) cells with thioredoxin, hexahistidine, and S. Tag fused consecutively at its amino terminus, and the fusion protein was purified by metal affinity chromatography. Several RNA fragments, prepared by in vitro transcription, were tested as substrates for the RNA-dependent RNA polymerase (RdRp) activity. Among them, the expressed fusion enzyme was able to generate a 32P-labeled RNA product when 3'-end RNA fragments of the positive strand or negative strand of BaMV were included in the assay mixture. Dot hybridization assay revealed that the reaction products are complementary to their RNA substrates. Taken together, the evidence suggests that the 155-kDa protein encoded by ORF1 of BaMV has an RdRp activity and should be involved in the replication of BaMV. Mutational analyses demonstrate the importance of the GDD motif in the polymerase activity, and deletion studies suggest that the polymerase activity resides in the carboxyl terminus of the 155-kDa viral protein.

Nasopharyngeal swab and PCR for the screening of nasopharyngeal carcinoma in the endemic area: a good supplement to the serologic screening

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a common head and neck cancer in Taiwan. Early detection is the best way to improve survival for this disease. A prospective study was designed to assess the feasibility of a new screening method for NPC by use of polymerase chain reaction (PCR) based on the close association of NPC and Epstein-Barr virus (EBV).

METHODS

One hundred thirty-three different tissues from nasopharynx, nose, and sinus were investigated by use of PCR to check for the presence of EBV genome. Subsequently, from April 1996 to March 1997, 55 patients were enrolled in a prospective screening study. All patients underwent nasopharyngeal swabs before biopsy. Polymerase chain reaction detection of EBV genome was conducted on swab samples. Anti-EBV viral capsid antigen (VCA) in IgA and IgG class were checked at the same visit.

RESULTS

The EBV genome was present in 91.4% (85/93) of NPC tissues and in 25.0% (10/40) of non-NPC tissues (p < .001, chi2 test). Of the 55 swabs, 49 (89.1%) specimens obtained enough cells for PCR examination. Thirty of these 49 patients were pathologically proved NPC. The presence of EBV were 86.7% (26/30) in NPC group and 42.1% (8/19) in non-NPC group. The sensitivity and specificity were 86.7% and 57.9%, respectively, which were similar to those of serologic method (87.5% and 43.5%) when the cut-off point was set at anti-VCA IgG > or = 160 and IgA > or = 10. Combining both methods elevates the specificity to 84.2%.

CONCLUSIONS

The sensitivity of this PCR screening method is similar to that of the serologic method. Combining both methods can greatly increase the specificity, indicating this new method is a good supplement to the serologic screening of this endemic disease.

Evolution of bamboo mosaic virus in a nonsystemic host results in mutations in the helicase-like domain that cause reduced RNA accumulation

A mutant population of bamboo mosaic potexvirus (BaMV) was isolated after serial passage using Chenopodium quinoa plants. While the wild type inoculum induced indistinct chlorotic lesions, the mutant produced obvious lesions on C. quinoa although RNA accumulation of the mutant in Nicotiana benthamiana protoplasts was significantly reduced compared to wild type. Mutations were identified in the helicase-like domain. One RT-PCR-generated cDNA clone (designated pL1-33) representing the helicase-like region showed four nucleotide mutations encoding three amino acid changes that were shown to result in dramatically decreased viral accumulation. Independent analyses of the effects of these substitutions showed that nucleotide changes at position 1722 resulting in a leucine to proline switch and position 2129 resulting in a histidine to tyrosine switch had the greatest effect on viral accumulation. Combination of these two mutations resulted in a undetectable viral accumulation. We have identified that amino acids within the helicase domain but outside the universally conserved helicase-like motifs that play an important role in viral amplification.

Harlequin ichthyosis: report of one case

Harlequin ichthyosis, or harlequin fetus, is a relatively rare, severe form of congenital ichthyosis. Although the clinical features have been well described, very little is known about the pathogenesis, clinical course, appropriate treatment and prognosis of harlequin ichthyosis because most of these babies with harlequin ichthyosis die within a few weeks of life. We herein report a case of harlequin ichthyosis, which we believe is the first such case in Taiwan.

Association of increased QT dispersion with coronary atherosclerosis in patients with aortic stenosis

To evaluate correlates between electrocardiographic QT dispersion and coronary atherosclerosis in patients with aortic stenosis before aortic valve replacement, 39 consecutive patients >40 years old with symptomatic aortic stenosis and coronary diameter narrowing > or =50% measured by digital angiographic study were included. An additional matched group with insignificant coronary lesions (<50%) consisted of 39 patients for comparisons. Matching by age, sex heart rate and incidence of chest pain resulted in two comparable groups with identical baseline characteristics. Preoperative transthoracic echocardiography and electrocardiograms were performed in all subjects. QT dispersion was defined as the difference between maximal and minimal QT interval measurements occurring among any of the 12 leads on a standard electrocardiogram. No subject had fewer than nine measurable leads. There were no significant differences of risk factors of coronary artery disease between the two groups. From a conditional multivariate logistic regression analysis, independent predictors of development of coronary artery disease in aortic stenosis were only QTc dispersion (odds ratio= 1.255, P=0.01). A wide QTc dispersion > or =70 ins) correlated with the presence of angiographically significant coronary artery disease with a sensitivity and specificity of 72% and 79%. The positive accuracy of having significant coronary artery disease in the presence of QTc dispersion > or =70 ms was 78%. The negative predictive value was 74%. In conclusion, electrocardiographic QTc dispersion may provide important clinical information. A wide QTc dispersion in patients with aortic stenosis is associated with a high incidence of coronary artery disease. These findings warrant further investigation in a large trial.

Primary hyperparathyroidism in pregnancy--report of 3 cases

Three cases of primary hyperparathyroidism in pregnancy are described. Patient 1 developed left thigh pain and lower abdominal pain at 34 weeks' gestation. Patient 2 had right flank pain and lower abdominal pain at 32 weeks' gestation. Both patients accepted medical therapy initially, which resulted in poor control of hypercalcemia. Patient 1 delayed her parathyroidectomy until the postpartum period; she had maternal hypercalcemia and neonatal hypocalcemia. Patient 2 accepted parathyroidectomy at 32 weeks' gestation with an uneventful outcome for both mother and baby. Patient 3 was asymptomatic; her hyperparathyroidism was diagnosed postpartum after neonatal hypocalcemia and agreed to parathyroidectomy. All 3 patients had a parathyroid adenoma.

Electrophysiological mechanisms for the antiarrhythmic activities of naloxone on cardiac tissues

It has been reported that naloxone, an opioid antagonist, has antiarrhythmic activity in vivo. In Langendorff perfused rat hearts, we found that ischemia-reperfusion-induced ventricular tachyarrhythmia reverted to normal sinus rhythm after the treatment with naloxone (3 approximately 10 microM). The method of voltage and current clamp were used to study the underlying mechanism of its antiarrhythmic activity on isolated cardiac myocytes. In isolated rat ventricular and in guinea-pig and human atrial myocytes, naloxone prolonged the action potential duration reversibly. In rat ventricular myocytes, naloxone (1 approximately 30 microM) inhibited sodium current (I(Na)), transient outward potassium current (I(to)), and calcium current (I(Ca)). On the contrary, the addition of naloxone significantly increased inward rectifier potassium current (I(K1)). For the effect on I(Na), naloxone did not shift the inactivation curve of I(Na) but retarded the I(Na) recovery rate from inactivation state. Naloxone suppressed I(to) with a significant left-shift of the inactivation curve, however, the time course of I(to) recovery from inactivation was not affected. In guinea pig atrial myocytes, naloxone (10 microM) decreased the delayed rectifier K+ current (IK). These results show that naloxone exert various extent of inhibition on I(Na), I(to), IK and I(Ca). The prolongation of cardiac action potential is related to the inhibition of I(to) and IK. The antiarrhythmic activity of naloxone is more closely related to the inhibition of Na+ and K+ currents rather than the blockade of myocardial opioid receptors.

Prenatal sonographic diagnosis of Cantrell's pentalogy with cystic hygroma in the first trimester

We report 2 cases of Cantrell's pentalogy with cystic hygroma diagnosed in the first trimester of pregnancy. Both fetuses had ectopia cordis, omphalocele, a sternal defect, and cystic hygroma detected by sonography. Cystic hygroma may be another characteristic of Cantrell's pentalogy in the first trimester.

Sister chromatid exchange in Chinese newborn infants treated with phototherapy for more than five days

The frequency of sister chromatid exchange (SCE) was determined in newborn infants given phototherapy for more than five days, then determined again one year later. There were 8 healthy newborn infants and 15 icterus infants; 8 of these were treated with phototherapy for more than 5 days and the other 7 were not. In the follow-up study, 6 treated infants were evaluated. The results revealed that there was an increase in mean SCE frequency of peripheral lymphocytes after phototherapy, which reversed itself one year after treatment discontinuation. Prolonged continuous phototherapy may be responsible for the increase observed in SCEs in Chinese newborn.

Effect of erythromycin on feeding intolerance in very low birth weight infants: a preliminary observation

To investigate the effect of erythromycin on feeding intolerance in very low birth weight infants, from February 1997 to December 1997 twenty infants weighing less than 1500 g, with prolonged intolerance of enteral feeding, were enrolled in this study. The protocol for erythromycin treatment was: a loading dose of 30 mg/kg/day, divided into three portions given every eight hours intravenously for 1 hour over a three day period; then a maintenance dose of 3-5 mg/kg intravenously for one hour once a day was given until full feeding was well established. The assessment of erythromycin effect was the daily net orogastric balance (volume of orogastric tube feeding minus volume of orogastric aspirates). The mean gestational age was 27.1 +/- 2.0 weeks (mean +/- SD) and the mean birth weight was 1025 +/- 196 g. The mean age when erythromycin started was 19.5 +/- 14 days; the mean days after the initiation of erythromycin when orogastric tube feeding could be started and full feeding established were 2.4 +/- 1.1 days and 15.1 +/- 2.2 days, respectively. At the beginning of erythromycin treatment, the net balance of tube aspirates was -4.8 +/- 4.1 ml. The net balance rose significantly to 30.6 +/- 15.3 ml, 92.6 +/- 25.4 ml and 125.3 +/- 18.1 ml at 7, 14 and 21 days after erythromycin treatment, respectively. In conclusion, erythromycin treatment is a safe method to improve intolerance of enteral feeding in very low birth weight infants. It is suggested that the effect of erythromycin on gastrointestinal motility in these infants should be further investigated in the context of a randomized, controlled trial before widespread clinical implementation of this treatment.

Increased ventricular repolarization inhomogeneity during postural changes in patients with syndrome X

The interlead variation in QT interval (QT dispersion) can be used to assess regional inhomogeneity of ventricular repolarization under a variety of conditions, including stress. Patients with syndrome X may have increased sympathetic activity that could change QT interval regionally and give rise to an increase in QT dispersion under exercise testing. To test the hypothesis, 26 consecutive patients with syndrome X (group 1) were studied. Two additional groups matched in terms of age, sex, and left ventricular mass index consisting of 26 nonconsecutive patients with coronary artery disease (group 2) and 20 normal subjects (group 3) were studied for comparison. Standing induced a significantly higher increase of heart rate in group 1 than in groups 2 and 3 (7.5+/-6.0 vs 4.0+/-6.3 and 1.1+/-3.6 beats/min; p = 0.05 and 0.003, respectively). There were significant differences in QT dispersion between groups 1 and 2 on upright standing (48+/-12 vs 34+/-14 ms, p = 0.0003), but not at baseline (33+/-14 vs 38+/-11 ms, p = NS) or at peak exercise (38+/-9 vs 38+/-9 ms, p = NS). Results did not change when QTc dispersion was substituted for QT dispersion. From a conditional multivariate logistic regression analysis, the only independent predictor of occurrence of syndrome X on upright standing was QTc dispersion (odds ratio = 1.255, p = 0.01). Electrocardiographic QTc dispersion provides important clinical information. Patients with syndrome X had a higher increase of heart rate and QTc dispersion in response to standing from the supine position compared with patients with coronary artery disease and normal subjects.

Successful prenatal digoxin therapy for Ebstein's anomaly with hydrops fetalis. A case report

BACKGROUND

Ebstein anomaly is a rare tricuspid valve anomaly. Some fetuses with Ebstein's anomaly have concurrent severe cardiac function impairment, which results in hydrops fetalis. Most of these fetuses are inevitably terminally ill. No reports have demonstrated the potential prenatal therapy for fetuses under such conditions.

CASE

Ebstein's anomaly and hydrops fetalis were detected at 28 weeks' gestation. Tricuspid regurgitation with congestive heart failure was observed. From 28 to 34 weeks' gestation, intrauterine therapy with digoxin, 0.75 mg/d, was administered. The fetal hydrops status improved gradually, while the tricuspid valve regurgitation persisted. At 36 weeks' gestation the fetus was delivered normally. During the neonatal phase, digoxin was continued and gradually tapered off. The tricuspid valve regurgitation and cardiomegaly gradually improved.

CONCLUSION

The favorable outcome in this case supports the positive effect of prenatal digoxin therapy for Ebstein's anomaly with hydrops fetalis. In such conditions, upon the appearance of hydrops and congestive cardiac failure, immediate digoxin therapy may be useful. This successful trial encouraged us to manage such fetuses more aggressively.

Emotional symptoms are secondary to the voice disorder in patients with spasmodic dysphonia

The aims of this study were to evaluate the emotional status and life quality of the patients with spasmodic dysphonia (SD) before and after botulinum toxin treatment, and to ascertain whether SD is a somatoform disorder. Ten patients with spasmodic dysphonia were injected unilaterally into the vocal cord with botulinum toxin. Before botulinum toxin treatment, two clinician's rating scales--Hamilton Depression Rating Scale (HDRS) and Hamilton Anxiety Rating Scale (HARS), and three self-rating psychometrics--Zung's Self-Rating Depression Scale (SDS), Life Quality Scale (GHQ/QL-12), and Symptom Distress Checklist (SCL-90) were applied. Self-rating scales were also administered in 20 matched normal controls. The patients were reevaluated 1 month after botulinum toxin treatment. The Clinical Global Impression Scale (CGI) was also rated by the patients themselves and a speech pathologist. The mean scores of SD patients were significantly higher than that of controls in SDS, and subscales of somatization, obsessive-compulsive symptoms, depression, anxiety, and psychoticism in SCL-90. The mean score of GHQ/QL-12 was significantly higher in the control group. The scores of HDRS, SDS, GHQ/QL-12 and subscales of somatization, depression, and anxiety in SCL-90 showed significant improvement after botulinum treatment. In CGI, seven patients were rated as improved by patients themselves and the speech pathologist. The patients with SD had more anxiety, depression and somatization symptoms, and poor life quality than normal controls. Their emotional status and life quality improved after botulinum toxin treatment. The results suggest that the emotional symptoms of patients with SD are mainly secondary to voice disorder.

Prenatal diagnosis of Apert syndrome

Apert syndrome (AS) is clinically characterized by typical facial features and symmetrical syndactyly of the digits. AS is inherited as an autosomal dominant trait. Recently, a fibroblast growth factor receptors 2 (FGFR2) mutation, either C934G or C937G, was identified in exon IIIa. Our report documents an affected mother and son in whom one of the two mutations in AS had occurred sporadically in the mother. The diagnosed of AS was based on associated abnormal physical features and on molecular genetic analysis. A C-to-G transversion at position 937 of the cDNA resulting in a proline-to-arginine substitution at codon 259 was found in the mother. In her second pregnancy, prenatal diagnosis by both restriction analysis and direct sequencing was undertaken and this showed that the female fetus had not inherited the mutation.

Detection of transcripts initiated from two viral promoters (Cp and Wp) in Epstein-Barr virus-infected nasopharyngeal carcinoma cells and biopsies

Different activation of Epstein-Barr virus (EBV) promoters results in distinct expression patterns of EBV nuclear antigens (EBNAs) and may further decide the role of EBV in the cellular pathogenesis. In EBV-associated nasopharyngeal carcinoma (NPC) biopsies, it has generally been believed that Q promoter (Qp)-initiated EBNA1 is the only EBNA gene to be expressed and that the other two viral promoters, Cp and Wp, which can lead to expression of EBNA1-6, are inactive. However, the failure to demonstrate the activities of Cp and Wp may have been due to the limited sensitivities of detection approaches used. In the present article, the EBV promoter usage and gene expression were re-examined in both EBV-infected NPC cells in vitro and NPC biopsies in vivo. An NPC cell line susceptible to EBV infection in vitro was established by transfection with a plasmid expressing a well-known EBV receptor, CR2. The presence of viral DNA and EBNA proteins was demonstrated in these EBV-infected cells using PCR and anticomplement immunofluorescence assay, respectively. As has been identified in NPC biopsies, viral transcripts of Qp-initiated EBNA1, latent membrane protein (LMP)1, LMP2A, LMP2B, and BamHI A genes, as well as the EBV-encoded small RNA (EBER)1 were detected in these in vitro-infected cells using reverse-transcription-PCR. Notably, viral transcripts initiated from Cp or Wp were also found in the infected cells. Furthermore, Cp- or Wp-initiated transcripts and EBNA2 mRNA were detected in some NPC biopsies. Taking advantage of this sensitive detection approach, our observation that Cp and Wp may be active in NPC cells raises the possibility that EBNA2 to 6, in addition to EBNA1, may play roles in the pathogenesis of NPC.

Late development of renal arteriovenous fistula following gunshot trauma--a case report

A 43-year-old man presenting with symptoms of congestive heart failure, cardiomegaly, and impaired left ventricular (LV) function was diagnosed as having a huge left renal arteriovenous (AV) fistula. The AV fistula might be attributed to a gunshot wound suffered during his military service twenty years ago. Percutaneous transcatheter arterial embolization utilizing multiple spring coils in conjunction with cyanoacrylic glue successfully occluded the fistula, with subsequent improvement of LV function and reduction of LV size on his serial echocardiographic follow-up.

Myelination arrest demonstrated using magnetic resonance imaging in a child with type I GM1 gangliosidosis

An 18-month-old girl was diagnosed as having GM1 gangliosidosis, on the basis of the clinical symptoms of muscle stiffness, developmental retardation, hepatosplenomegaly, and kyphoscoliosis and a laboratory study that revealed a deficiency in the lysosomal degradative enzyme beta-galactosidase. Magnetic resonance T1-weighted images showed persistent hyperintensity in the bilateral thalami, brainstem, and deep cerebellum at 14 and 18 months of age, indicating arrest of the myelination process in these areas, and that the arrest had occurred at the newborn stage. There was no myelination in the basal ganglia and diffuse leukomalacia developed in the cerebral hemispheres. Only supportive treatment was given; the patient died at 2 years of age. Myelination arrest at the newborn stage associated with progressive leukomalacia is a possible characteristic of GM1 gangliosidosis.