Specific valylation of turnip yellow mosaic virus RNA by wheat germ valyl-tRNA synthetase determined by three anticodon loop nucleotides

The valylation by wheat germ valyl-tRNA synthetase of anticodon loop mutants of turnip yellow mosaic virus RNA has been studied. RNA substrates 264 nucleotides long were made by T7 RNA polymerase from cDNA encompassing the 3' tRNA-like region of genomic RNA. Substitution singly, or in combination, of three nucleotides in the anticodon loop resulted in very poor valylation (Vmax/KM less than 10(-3) relative to wild type). These nucleotides thus represent the major valine identity determinants recognized by wheat germ valyl-tRNA synthetase; their relative contribution to valine identity, in descending order, was as follows: the middle nucleotide of the anticodon (A56 in TYMV RNA), the 3' anticodon nucleotide (C55), and the 3'-most anticodon loop nucleotide (C53). Substitutions in the wobble position (C57) had no significant effect on valylation kinetics, while substitutions of the discriminator base (A4) resulted in small decreases in Vmax/Km. Mutations in the major identity nucleotides resulted in large increases in KM, suggesting that wheat germ valyl-tRNA synthetase has a lowered affinity for variant substrates with low valine identity. Comparison with other studies using valyl-tRNA synthetases from Escherichia coli and yeast indicates that the anticodon has been phylogenetically conserved as the dominant valine identity region, while the identity contribution of the discriminator base has been less conserved. The mechanism by which anticodon mutations are discriminated also appears to vary, being affinity-based for the wheat germ enzyme, and kinetically-based for the yeast enzyme [Florentz et al. (1991) Eur. J. Biochem. 195, 229-234].

Second-site suppressor mutations assist in studying the function of the 3' noncoding region of turnip yellow mosaic virus RNA

The 3' noncoding region of turnip yellow mosaic virus RNA includes an 82-nucleotide-long tRNA-like structure domain and a short upstream region that includes a potential pseudoknot overlapping the coat protein termination codon. Genomic RNAs with point mutations in the 3' noncoding region that result in poor replication in protoplasts and no systemic symptoms in planta were inoculated onto Chinese cabbage plants in an effort to obtain second-site suppressor mutations. Putative second-site suppressor mutations were identified by RNase protection and sequencing and were then introduced into genomic cDNA clones to permit their characterization. A C-57----U mutation in the tRNA-like structure was a strong suppressor of the C-55----A mutation which prevented both systemic infection and in vitro valylation of the viral RNA. Both of these phenotypes were rescued in the double mutant. An A-107----C mutation was a strong second-site suppressor of the U-96----G mutation, permitting the double mutant to establish systemic infection. The C-107 and G-96 mutations are located on opposite strands of one helix of a potential pseudoknot, and the results support a functional role for the pseudoknot structure. A mutation near the 5' end of the genome (G + 92----A), at position -3 relative to the initiation codon of the essential open reading frame 206, was found to be a general potentiator of viral replication, probably as a result of enhanced expression of open reading frame 206. The A + 92 mutation enhanced the replication of mutant TYMC-G96 in protoplasts but was not a sufficiently potent suppressor to permit systemic spread of the A + 92/G-96 double mutant in plants.

Noma neonatorum: an unusual case of noma involving a full-term neonate

Noma neonatorum is a gangrenous process that occurs in the oral, nasal or anal area and occasionally the eyelids and scrotum of the newborn. The disease is caused by Pseudomonas aeruginosa and usually affects premature ill babies during the first few weeks of life. A full-term neonate with nasal and scrotal noma is uncommon and is therefore reported.

Deoxycytidine deaminase-resistant stereoisomer is the active form of (+/-)-2',3'-dideoxy-3'-thiacytidine in the inhibition of hepatitis B virus replication

2',3'-Dideoxy-3'-thiacytidine (+/-)-SddC) was found to have potent activity against human hepatitis B virus as well as human immunodeficiency viruses in culture. The (-)form ((-)-SddC) which is resistant to deoxycytidine deaminase was found to be the more active antiviral stereoisomer than the (+)-form ((+)-SddC). The (+)-SddC is susceptible to deamination by deoxycytidine deaminase and is 25- and 12-fold more toxic than (-)-SddC in CEM cells in terms of anti-cell growth and anti-mitochondrial DNA synthesis, respectively. Similar results were obtained using a mixture of their 5-fluoro analogs ((+/-)-FSddC). Unlike 2',3'-dideoxycytidine, which is a potent inhibitor of mitochondrial DNA synthesis and results in such delayed toxicity as peripheral neuropathy with long term usage, (-)-SddC does not affect mitochondrial DNA synthesis. The (-)form is phosphorylated to (-)-SddCMP and is subsequently converted to (-)-SddCDP and (-)-SddCTP. One additional major metabolite which has been tentatively assigned the name "(-)-SddCMP sialate" was also identified. No significant difference in terms of the profiles of the metabolites was found between 4 and 24 h. There is an appreciable amount of (-)-SddCTP detectable 24 h after removal of the drug. (-)-SddCTP was also found to be approximately 3-fold more potent than (+)-SddCTP in inhibiting human hepatitis B virus DNA polymerase. This is the first nucleoside analog with the unnatural sugar configuration demonstrated to have antiviral activity.

The hypoglossia-hypodactylia syndrome: report of two cases

Two cases of hypoglossia-hypodactylia syndrome are reported. This syndrome is characterized by reduction in the size of tongue, micrognathia and variable limb anomalies. In these present cases, both karyotypes revealed normal. The unrelated parents and siblings are normal. Drug exposure to the mother during pregnancy was negative. Since this syndrome is rare and no previous report in Taiwan. So we report these two cases and review the literature.

G syndrome: report of two cases

This report concerns two cases of G syndrome in male neonates with hypertelorism, hypospadias and hoarse/voiceless cry. Case 1 had a positive family history; all similarly affected relatives have apparent hypertelorism. Case 2 seemed to represent a new mutation, since the parents are apparently normal, and the family history was non-contributory. The clinical expression of Case 1 was relatively severe and needed further surgical management, such as imperforate anus, hypospadias, and vesicoureteral reflux. Case 2 had two manifestations not previously reported: hypoplasia of cerebellum and web neck.

Therapeutic embolization of post-cholecystectomy hepatic artery aneurysm

A "sandwich" technique employing steel coils and gelfoam embolization was applied in two cases of hepatic artery aneurysms. Immediate cessation of the bleeding was evident clinically and the post-embolization angiogram showed occlusion of the vascular lesion. Cholecystectomy is one of the most common abdominal operations and it is generally well tolerated, particularly in young and middle-aged patients. Morbidity rates of 5% to 32% and mortality rates of 0.4% to 2.5% have been reported, depending on such factors as age, underlying illness, etc. (1-4). The most frequent complications of cholecystectomy are wound infection, abscess, ductal injury or ligation, and bleeding. This paper describes two cases of hepatic pseudoaneurysm following iatrogenic damage during cholecystectomy which was treated with transarterial embolization.

Circumaortic left renal vein: report of a case

Circumaortic left renal vein is an uncommon anomaly which has not been previously reported in Taiwan. We describe a case of circumaortic left renal vein in a 15-year-old girl who presented with intermittent hematuria. Angiogram revealed double left renal veins in the form of a venous collar. Computed tomography depicted the preaortic and retroaortic left renal veins clearly. In a survey of hematuria, circumaortic renal vein should be taken into consideration in a differential diagnosis, and an appreciation of the specific radiologic findings can help to establish the diagnosis easily. In addition, preoperative recognition of this uncommon anomaly is of supreme importance in a retroperitoneal operation in order to avoid massive bleeding.

[Low social economic status family and child maltreatment]

The purpose of the present research was to develop child abuse potential inventories as a screening tool. The sample was 248 families who were all financially supported by Chinese Children's Fund. Kaohsiung Family Helper. One of the inventories selected, that was translated into Chinese by the expert committee, was the Child Abuse Potential Inventory developed by Milner. The internal consistency and test-retest reliabilities obtained by this research were as good as Milner's and basic interpretation of four factors was found to be was consistent with Milner's data. The other inventory developed by the expert committee was the Child Abuse Potential Interview used by social workers to interview caretakers. Having completed the questionnaire social workers rated 15 items, i.e. immaturity, lack of parenting skills, unrealistic expectancy, social isolation, unresolved affective needs, abused experiences, crisis, substance abuse etc. The coefficients of correlation between these two inventories were 0.20-0.37, respectively, which indicated that these inventories assessed abuse potential trait and uniqueness. Therefore, these inventories were considered both highly applicable.

Pseudoathetosis as a presenting symptom of spinal multiple sclerosis

We report on a 38-year-old female patient with acute proprioceptive sensory impairment and pseudoathetosis in the four limbs, particularly in the fingers of both hands. She had great difficulty in buttoning, unbuttoning, using chopsticks and writing, because she was no longer able to feel her fingers in space. There was a profound loss of position and vibration sensation in all limbs, especially in both hands. Pseudoathetoid movement, a rare presentation of multiple sclerosis, was observed in the outstretched hands and extended fingers. T1- and T2-weighted magnetic resonance imaging (MRI) of the spinal cord revealed an inactive intramedullary lesion in the C2-C5 segments. Gadolinium-enhanced MRI revealed an active lesion in the posterior columns of the cervical cord at the C3 vertebral level, which is very likely responsible for pseudoathetoid movement. Based on the disseminated lesions in the spinal cord verified by MRI the four neurologic manifestations, and the abnormal somatosensory-evoked potentials, we made a definitive diagnosis of multiple sclerosis of the spinal cord.

Inhibition of the replication of hepatitis B virus in vitro by 2',3'-dideoxy-3'-thiacytidine and related analogues

Several 2',3'-dideoxy-3'-thiapyrimidine nucleosides were studied for their ability to inhibit hepatitis B virus (HBV) DNA replication in a HBV-transfected cell line (2.2.15). 2',3'-Dideoxy-3'-thiacytidine (SddC) and 5-fluoro-2',3'-dideoxy-3'-thiacytidine(5-FSddC) were found to be the most potent anti-HBV compounds of those examined. Both compounds resulted in nearly complete cessation of viral DNA replication at 0.5 microM, as monitored by the absence of both intracellular episomal and secreted viral DNAs. The HBV-specific RNAs were not reduced at concentrations that completely blocked HBV DNA replication, suggesting that the inhibitory target is HBV DNA synthesis. The antiviral action of SddC and 5-FSddC was reversible. The concentration of SddC and 5-FSddC required to inhibit 50% of 4-day cell growth in culture was 37 microM and more than 200 microM, respectively. Unlike 2',3'-dideoxycytidine, these two compounds do not affect mitochondrial DNA synthesis in cells at concentrations lower than that required to inhibit cell growth. In view of the potent and selective antiviral activity, both SddC and 5-FSddC should be further evaluated for the treatment of human HBV infection.

Early onset parkinsonism in Chinese

We describe the clinical features of parkinsonism in 25 patients whose age of onset was under 40 years. Among them, 17 patients, whose age of onset was after their 21st birthday, were classified as young onset Parkinson's disease (YOPD), and the remaining 8 whose age of onset was before their 21st birthday were classified as juvenile parkinsonism (JP). Rigidity and akinesia were revealed in all 25 patients. Resting tremor was observed in only 5 patients; 3 in the YOPD group and 2 in the JP group. There were 8 of the 25 patients (32%) who experienced an aching sensation in the leg before or at the onset of the parkinsonian features. In 6 of these 8 cases, the sensory symptoms were on the same side where the clinical manifestations of parkinsonism later developed. In the JP group, 2 patients had right foot dystonia, which improved with levodopa. Diurnal fluctuations in parkinsonian symptoms were found in 9 of the 25 cases. The familial incidence of parkinsonism was higher in the JP group. The parkinsonian disabilities in all 25 cases responded dramatically to levodopa therapy. Unfortunately, 10 cases, 5 in the YOPD group and 5 in the JP group, developed dyskinesia. The longer they took levodopa, the greater the chance of developing dyskinesia. The cumulative percentage of dyskinesia was 100% in the YOPD group and 83% in the JP group by the seventh and fourth year of treatment, respectively. A positive correlation was found between the prevalence of dyskinesia and the duration of treatment in both groups.

Turnip yellow mosaic virus RNAs with anticodon loop substitutions that result in decreased valylation fail to replicate efficiently

Single and multiple nucleotide substitutions have been introduced into the anticodon loop of the tRNA-like structure of turnip yellow mosaic virus (TYMV) genomic RNA. We studied the effects of these mutations on in vitro valylation and on replication in Chinese cabbage protoplasts and plants. Only those mutants capable of efficient and complete valylation showed efficient replication in protoplasts and gave rise to systemic symptoms in whole plants. Mutants that accepted valine inefficiently (in some cases Vmax/Km values were less than 10(-3) relative to wild-type values) replicated to levels 200- to 500-fold below wild-type levels in protoplasts (estimated on the basis of coat protein and genomic RNA levels). These mutants could not support systemic spread in plants. In one plant inoculated with TYMC-A55 RNA, which replicates poorly in protoplasts, systemic symptoms developed after a delay. The reversion in replication was accompanied by improved valine acceptance and the appearance of a U57 second-site mutation. Our results indicate a correlation between valine acceptance activity and viral yield. Possible roles for valylation are discussed, and the results are compared with those of similar studies with brome mosaic virus which suggested that tyrosylation is not crucial for brome mosaic virus replication (T. W. Dreher, A. L. N. Rao, and T. C. Hall, J. Mol. Biol. 206:425-438, 1989).

Characterization of two monoclonal antibodies to Epstein-Barr virus diffuse early antigen which react to two different epitopes and have different biological function

Five monoclonal antibodies (mAbs) were identified using immunofluorescence that were specific for the Epstein-Barr virus (EBV) encoded 52/50 kDa early antigen (EA-D) protein complex. Evidence to suggest that these mAbs react with the same 52/50 kDa EA-D protein was obtained by Western blotting, immunoprecipitation and ELISA. Two of the mAbs, 90E2 and 214A9, neutralized EBV DNA polymerase activity. The 214A9 mAb also inhibited the activity of bacteriophage T4 DNA polymerase while the 90E2 mAb did not. These data suggest that the 90E2 and 214A9 mAbs recognize two different epitopes on the 52/50 kDa EA-D protein. The high frequency of recovery of hybridomas producing anti 52/50 kDa EA-D mAbs suggest that this protein may have an important role in EBV pathogenesis/replication.

Niemann-Pick disease type B with ocular involvement: report of a case

Niemann-Pick disease (NPD) type B was diagnosed clinically and enzymatically in a 5-year-old girl presenting with failure to thrive, hepatosplenomegaly, diffuse interstitial infiltration of both lungs on chest roentgenograms, cherry red spot, and foam cells in the bone marrow aspirate. Intelligence and neurological examination were normal, sphingomyelinase activity was severely deficient in cultured skin fibroblasts. We present the first case of NPD type B in Taiwan and relevant literatures were reviewed.

Heterotopic heart transplantation--a life-saving procedure with a size-mismatched donor

A 32-year-old B-type male weighing 60 kg suffered from end-stage dilated cardiomyopathy. Although aggressive medical treatment with dobutamine 21 micrograms/kg/min, dopamine 17 micrograms/kg/min, digoxin 0.25 mg i.v. once daily, furosemide 40 mg i.v. every 6 h, and bumetanide 0.5 mg i.v. every 6 h were given, he was finally ventilator dependent for the last 3 weeks until a B-type donor weighing 42.5 kg was found. Because of the 29.2% weight mismatch, a heterotopic heart transplantation was performed. Posterior plication mitral annuloplasty was also performed to correct the severe mitral regurgitation of the recipient heart. Postoperatively the patient remained respirator dependent for 17 days and was finally discharged in good condition on the 46th postoperative day.

A comparison of Epstein-Barr virus specific proteins expressed by three Epstein-Barr virus isolates using specific monoclonal antibodies

Monoclonal antibodies (MAbs) were prepared in mice inoculated with a nasopharyngeal carcinoma Epstein-Barr virus (NPC-EBV) producer lymphoblastoid cell line (NPC-LC). When the 214A9 MAb was used to study the expression of the 52/50-kD early antigen in NPC-LC, B95-8, and HR-1 cells, no difference was found. The same results were obtained with the 343D12 MAb which is to a 125-kD virus capsid antigen protein. However, the 244G11 MAb detected an EBV membrane antigen (MA) with a molecular weight of 220 kD in both B95-8 and HR-1 cells, but reacted with a 250-kD MA protein in the NPC-LC cells. Similar results were obtained with the 201D6 MAb which reacted with a MA polypeptide with a molecular weight of 220/200 kD in HR-1 and B95-8 cells and one of 250/200 kD in NPC-LC cells. The data suggest that there may be differences in at least two MA proteins synthesized by the NPC-EBV isolate as compared with the prototype HR-1 and B95-8 EBV isolates.

A monoclonal antibody that neutralizes Epstein-Barr virus, human cytomegalovirus, human herpesvirus 6, and bacteriophage T4 DNA polymerases

A monoclonal antibody (mAb) designated 55H3 was produced by using chemically induced Epstein-Barr virus genome-positive B95-8 cells. mAb 55H3, which reacted with an 85- to 80-kDa polypeptide, neutralized Epstein-Barr virus-encoded DNA polymerase activity in crude extracts of chemically induced M-ABA, HR-1, and B95-8 cells, as well as the partially purified Epstein-Barr virus DNA polymerase in a dose-dependent manner. The mAb also neutralized the virus-encoded DNA polymerase activity from cells infected with human cytomegalovirus, human herpesvirus 6, and the purified bacteriophage T4 DNA polymerases. However, mAb 55H3 did not neutralize the DNA polymerase activities encoded for by herpes simplex virus types 1 and 2, the reverse transcriptase of avian myeloblastosis virus, or Escherichia coli DNA polymerase 1 (Klenow fragment). These results suggest that mAb 55H3 recognizes an epitope common to some herpesviruses and T4 DNA polymerases and further supports the hypothesis that these organisms are evolutionarily related.

[A survey on weight and height of children (1 month-7 years) and plotting of growth curves (1 month-18 years) in Taiwan, 1987-1988]

From July 1987 to December 1988, 19,625 children in Taiwan were measured for their body weights and heights. They were 9,564 boys and 10,061 girls and were seen either in a well baby clinic of a large community hospital or in the local kindergartens. We divided these children into 64 groups according to their sex and ages. The mean values and standard deviation of body weight and height were tried to correlate with those from children of school age reported for 1987 by the Ministry of Education. Furthermore, body weight and height growth curves were drawn for these children, aged from 1 month to 18 years.

[Bacterial meningitis in neonates]

A retrospective study of the clinical features and management of 27 newborns with meningitis is presented. All were treated in the China Medical College Hospital between July 1981 and July 1988. Seven were premature and twenty were full term. There were 11 males and 16 females. Five infants had low birth weight (less than 2500 g) and 12 cases were diagnosed in the first week of life (early onset). E.coli was the predominant pathogen. The most common presenting manifestations were nonspecific in nature-fever, poor feeding, respiratory distress and poor activity, etc... Six patients died during the period of acute illness and the case fatality rate was 22.2%. Of the 21 patients who survived, six had sequelae (four hydrocephalus, one subdural effusion, one microcephaly), giving an over-all rate of 19 percent in the survivors. The presence of gram-negative bacterial infection and high protein content in CSF correlated significantly with the higher mortality rate.

Ruptured aneurysms of the sinus of Valsalva in Oriental patients

Between 1964 and 1987, a total of 57 cases of ruptured aneurysm of the sinus of Valsalva underwent surgical correction at the National Taiwan University Hospital. This represents 0.96% of all cardiac operations. The origin of ruptured aneurysm of the sinus of Valsalva was the right coronary sinus in 46, the noncoronary sinus in nine, and the left coronary sinus in two. The aneurysms ruptured into the right ventricle in 44, into the right atrium in 11, into the left ventricle in one, and into both the right ventricle and right atrium in one. Associated congenital cardiac anomalies included ventricular septal defect in 30 patients, aortic regurgitation in 20, and infundibular pulmonic stenosis and coarctation of the aorta in one each. Operative death occurred in two patients (3.5%) and one patient had a successful reoperation. The remainder did well following surgery. To compare the differences between Oriental and Western countries in ruptured aneurysm of the sinus of Valsalva, 361 cases (195 Oriental patients versus 166 Western) were collected from the literature. Analyses of these cases revealed that ruptured aneurysm of the sinus of Valsalva in Oriental patients compared with Western series is characterized by a higher incidence (5 times), more aneurysms originating from the right coronary sinus (87.9% versus 63.6%), more aneurysm rupturing into the right ventricle (84.2% versus 56.6%), a higher incidence of association with ventricular septal defect (mainly supracristal) (59.0% versus 34.6%), less incidence of association with other congenital cardiac abnormalities (4.1% versus 21.5%), very few instances of rupturing into cardiac chambers other than the right ventricle and right atrium, and less incidence of occurrence in the extremities of ages (the youngest was 7 years in Oriental patients versus 11 months in the Western series). In other words, ruptured aneurysm of the sinus of Valsalva in Oriental patients is more or less a simple and uniform disease entity in contrast to the more diverse and protean pathologic profiles encountered in Western series. However, both Oriental patient and Western patient series have similar incidences of combination with aortic regurgitation (24.6% versus 20.0%), with 40.4% of Oriental patients and 60.6% of Western patients presenting with intact ventricular septum. Therefore the pathogenetic mechanisms of ruptured aneurysm of the sinus of Valsalva may at the same time contribute to the development of aortic regurgitation.

Establishment and characterization of two epithelial tumor cell lines (HNE-1 and HONE-1) latently infected with Epstein-Barr virus and derived from nasopharyngeal carcinomas

Two epithelial tumor cell lines were established from biopsy specimens of 2 nasopharyngeal carcinomas (NPC) and designated HNE-1 and HONE-1. Uncloned HNE-1 cells were found to be Epstein-Barr virus (EBV) DNA-positive when examined by Southern blot analysis up to passage 35, after which the EBV genome could no longer be detected. A similar loss of EBV DNA took place in uncloned HONE-1 cells. However, HONE-1 clone 40 cells are still EBV DNA-positive up to passage 42 thus far and cell cultures contain 85-90% EBV nuclear antigen (EBNA)-positive cells. The HNE-1 cell line has been passaged more than 100 times and the uncloned HONE-1 cells more than 90 times. The tumorigenicity of the HNE-1 and HONE-1 cells was demonstrated by tumor induction in nude mice. Karyotypic analysis of the HNE-1 cells demonstrated an aneuploidy with a modal chromosomal number of 74 at passages 5 and 101 at passage 20; 18 marker chromosomes were identified. We have continued to map the EBV genome latently associated with the HNE-1 and HONE-1 cells using the Bam HI, EcoRI or Hind III restriction enzymes. Using EcoRI fragments A-K as probes, we found that HNE-1 EBV DNA is different from B95-8 and HR-1 EBV DNA in the EcoRI-C region. The Bam HI map for HONE-1 EBV DNA is very similar to the B95-8 map; it contains the Bam HI-Y fragment but without Bam HI B' and WI'. Differences were observed between HONE-1 EBV DNA and B95-8 DNA using the Hind III restriction enzyme. There was no evidence of spontaneous expression of the latent EBV genome in HNE-1 cells, and attempts to induce replication of the latent EBV genome and rescue infectious virus have failed, suggesting a tightly restricted virus genome.