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1.
Epidemiol Infect ; 149: e53, 2021 02 22.
Article in English | MEDLINE | ID: mdl-33612125

ABSTRACT

Previous studies have reported the basic reproduction number (R0) of coronavirus disease from publicly reported data that lack information such as onset of symptoms, presence of importations or known super-spreading events. Using data from the Republic of Korea, we illustrated how estimates of R0 can be biased and provided improved estimates with more detailed data. We used COVID-19 contact trace system in Korea, which can provide symptom onset date and also serial intervals between contacted people. The total R0 was estimated as 2.10 (95% confidence interval (CI) 1.84-2.42). Also, early transmission of COVID-19 differed by regional or social behaviours of the population. Regions affected by a specific church cluster, which showed a rapid and silent transmission under non-official religious meetings, had a higher R0 of 2.40 (95% CI 2.08-2.77).


Subject(s)
Basic Reproduction Number , COVID-19/epidemiology , Epidemics , SARS-CoV-2/physiology , COVID-19/virology , Humans , Republic of Korea/epidemiology
2.
Br J Dermatol ; 177(4): 1086-1092, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28421601

ABSTRACT

BACKGROUND: The Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) and Cutaneous Assessment Tool-Binary Method (CAT-BM) have been shown to be reliable and valid outcome measures to assess cutaneous disease in adult dermatomyositis (DM) and juvenile DM (JDM), respectively. OBJECTIVES: This study compared the CDASI and CAT-BM for use by paediatric dermatologists, paediatric rheumatologists and paediatric neurologists in patients with JDM. METHODS: Five paediatric dermatologists, five paediatric rheumatologists and five paediatric neurologists each evaluated 14 patients with JDM using the CDASI, CAT-BM, and skin Physician Global Assessment (PGA) scales. Inter-rater reliability, intra-rater reliability, construct validity and completion time were compared. RESULTS: Inter-rater reliability for CDASI activity and damage scores was good to moderate for paediatric dermatologists and rheumatologists, but poor for paediatric neurologists. The inter-rater reliability for CAT-BM activity scores was moderate for paediatric dermatologists and rheumatologists, but poor for paediatric neurologists and poor across all specialties for damage scores. Intra-rater reliability for the CDASI and CAT-BM activity and damage scores was moderate to excellent for paediatric dermatologists, rheumatologists and neurologists. Strong associations were found between skin PGA activity and damage scores and CDASI or CAT-BM activity and damage scores, respectively (P < 0·002). The CDASI had a mean completion time of 5·4 min compared with that for the CAT-BM of 3·1 min. CONCLUSIONS: Our data confirm the reliability of the CDASI activity and damage scores and the CAT-BM activity scores when used by paediatric dermatologists and rheumatologists in assessing JDM. Significant variation existed in the paediatric neurologists' scores.


Subject(s)
Dermatomyositis/diagnosis , Severity of Illness Index , Child , Dermatologists , Female , Humans , Male , Neurologists , Observer Variation , Physical Examination/methods , Rheumatologists , Sensitivity and Specificity
3.
J Perinatol ; 36(12): 1092-1096, 2016 12.
Article in English | MEDLINE | ID: mdl-27583390

ABSTRACT

OBJECTIVE: This study aimed to examine changes in cytokines according to therapeutic hypothermia (TH) for newborn hypoxic ischemic encephalopathy (HIE). STUDY DESIGN: We studied 20 neonates who were admitted with a diagnosis of HIE in the neonatal intensive care unit. Cytokine concentration assay was carried out for neonates (n=12) who received TH and neonates (n=8) who were not treated with hypothermia by collecting blood sample at 12, 48 and 120 h after birth. RESULTS: At 48 h after birth, interleukin (IL)-6 in the normothermia group was higher than that in the hypothermia group (P=0.010). At 48 h after birth, IL-10 was higher in the hypothermia group than in the normothermia group (P=0.038). CONCLUSION: This study confirmed that TH performs a role in the prevention of inflammatory process by way of maintaining proinflammatory cytokine IL-6 at low levels and anti-inflammatory cytokines IL-10 at high levels.


Subject(s)
Hypothermia, Induced/methods , Hypoxia-Ischemia, Brain/therapy , Interleukin-10/blood , Interleukin-6/blood , Case-Control Studies , Electroencephalography , Enzyme-Linked Immunosorbent Assay , Gestational Age , Humans , Hypoxia-Ischemia, Brain/blood , Infant, Newborn , Retrospective Studies , Severity of Illness Index , Statistics, Nonparametric , Time Factors
4.
J Neurol Neurosurg Psychiatry ; 86(8): 873-8, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25430934

ABSTRACT

BACKGROUND: The international Inherited Neuropathy Consortium (INC) was created with the goal of obtaining much needed natural history data for patients with Charcot-Marie-Tooth (CMT) disease. We analysed clinical and genetic data from patients in the INC to determine the distribution of CMT subtypes and the clinical impairment associated with them. METHODS: We analysed data from 1652 patients evaluated at 13 INC centres. The distribution of CMT subtypes and pathogenic genetic mutations were determined. The disease burden of all the mutations was assessed by the CMT Neuropathy Score (CMTNS) and CMT Examination Score (CMTES). RESULTS: 997 of the 1652 patients (60.4%) received a genetic diagnosis. The most common CMT subtypes were CMT1A/PMP22 duplication, CMT1X/GJB1 mutation, CMT2A/MFN2 mutation, CMT1B/MPZ mutation, and hereditary neuropathy with liability to pressure palsy/PMP22 deletion. These five subtypes of CMT accounted for 89.2% of all genetically confirmed mutations. Mean CMTNS for some but not all subtypes were similar to those previously reported. CONCLUSIONS: Our findings confirm that large numbers of patients with a representative variety of CMT subtypes have been enrolled and that the frequency of achieving a molecular diagnosis and distribution of the CMT subtypes reflects those previously reported. Measures of severity are similar, though not identical, to results from smaller series. This study confirms that it is possible to assess patients in a uniform way between international centres, which is critical for the planned natural history study and future clinical trials. These data will provide a representative baseline for longitudinal studies of CMT. CLINICAL TRIAL REGISTRATION: ID number NCT01193075.


Subject(s)
Charcot-Marie-Tooth Disease/classification , Adaptor Proteins, Signal Transducing , Cell Cycle Proteins , Charcot-Marie-Tooth Disease/genetics , Charcot-Marie-Tooth Disease/pathology , Charcot-Marie-Tooth Disease/physiopathology , Connexins/genetics , Cost of Illness , Cross-Sectional Studies , Female , GTP Phosphohydrolases/genetics , Humans , Male , Mitochondrial Proteins/genetics , Mutation/genetics , Myelin P0 Protein/genetics , Myelin Proteins/genetics , Nuclear Proteins , Proteins/genetics , Gap Junction beta-1 Protein
5.
J Med Genet ; 47(9): 601-7, 2010 Sep.
Article in English | MEDLINE | ID: mdl-19939853

ABSTRACT

BACKGROUND: Genomic copy number variants have been shown to be responsible for multiple genetic diseases. Recently, a duplication in septin 9 (SEPT9) was shown to be causal for hereditary neuralgic amyotrophy (HNA), an episodic peripheral neuropathy with autosomal dominant inheritance. This duplication was identified in 12 pedigrees that all shared a common founder haplotype. METHODS AND RESULTS: Based on array comparative genomic hybridisation, we identified six additional heterogeneous tandem SEPT9 duplications in patients with HNA that did not possess the founder haplotype. Five of these novel duplications are intragenic and result in larger transcript and protein products, as demonstrated through reverse transcription-PCR and western blotting. One duplication spans the entire SEPT9 gene and does not generate aberrant transcripts and proteins. The breakpoints of all the duplications are unique and contain regions of microhomology ranging from 2 to 9 bp in size. The duplicated regions contain a conserved 645 bp exon within SEPT9 in which HNA-linked missense mutations have been previously identified, suggesting that the region encoded by this exon is important to the pathogenesis of HNA. CONCLUSIONS: Together with the previously identified founder duplication, a total of seven heterogeneous SEPT9 duplications have been identified in this study as a causative factor of HNA. These duplications account for one third of the patients in our cohort, suggesting that duplications of various sizes within the SEPT9 gene are a common cause of HNA.


Subject(s)
Brachial Plexus Neuritis/enzymology , Brachial Plexus Neuritis/genetics , Chromosome Duplication/genetics , Septins/genetics , Base Pairing/genetics , Base Sequence , DNA Mutational Analysis , Exons/genetics , Female , Humans , Male , Molecular Sequence Data , Pedigree , Recurrence
6.
Hong Kong Med J ; 15(4): 267-73, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19652233

ABSTRACT

OBJECTIVES: To evaluate the efficacy of a fixed dose of radioactive iodine (131-I) in the treatment of thyrotoxicosis, and to identify risk factors associated with treatment failure. DESIGN: Retrospective study. SETTING: Thyroid Clinic of a regional hospital in Hong Kong. PATIENTS: Patients receiving their first dose of radioactive iodine for the treatment of thyrotoxicosis during the inclusive period September 1999 to August 2004. MAIN OUTCOME MEASURES: Relapse rate and time to relapse. RESULTS: A total of 113 patients received a fixed dose of 5 mCi (185 MBq), 6 mCi (222 MBq), 8 mCi (296 MBq), and 10 mCi (370 MBq) 131-I in a proportion of 1:6:71:35. At 1 year, 42 (37%) of the patients had relapsed, of which 69% received a second 131-I dose. The median time to relapse after first receiving 131-I was 4 months. At 1 year, the remaining 71 (63%) of the patients were successfully treated; 46 (41%) were euthyroid, and 25 (22%) had became permanently hypothyroid. Basal free thyroxine level and goitre size were significantly associated with a relapse rate after a single dose of 131-I; larger goitres showed a trend towards high rates of relapse. Patients pretreated with propylthiouracil had a higher rate of relapse during the first year after radioactive iodine than those pretreated with carbimazole, but the difference was not significant when combined with other pretreatment variables. CONCLUSIONS: A single fixed dose of radioactive iodine is a simple, safe, and effective treatment for hyperthyroidism. High basal free thyroxine concentration and large goitre size are associated with higher chance of relapse. Higher radioiodine doses may be considered to improve the cure rate.


Subject(s)
Hyperthyroidism/radiotherapy , Iodine Radioisotopes/administration & dosage , Thyrotoxicosis/radiotherapy , Adult , Biomarkers/blood , Chi-Square Distribution , Female , Hong Kong , Humans , Logistic Models , Male , Retrospective Studies , Thyroid Hormones/blood , Treatment Outcome
7.
BMJ Case Rep ; 20092009.
Article in English | MEDLINE | ID: mdl-21686915

ABSTRACT

A 60-year-old man was referred as an emergency with a 3 month history of left sided abdominal pain and weight loss. He had no other medical problems and took no medications. An endoscopy was performed. This demonstrated a normal oesophagus and stomach and a fleshy mass in the first part of the duodenum with surrounding slough. As this was presumed to be malignant, biopsies were taken. Computed tomography (CT) scan of the abdomen was performed which showed a large, complex, loculated intra-abdominal collection containing air. Results from duodenal biology showed the presence of ulcer slough and liver tissue. The patient was diagnosed with a perforated duodenal ulcer, which had occurred some months previously, and which had eroded into the liver. He was observed and treated with intravenous antibiotics. The patient was discharged on day 14. Follow-up CT scan at 6 weeks showed complete resolution of the collection.

8.
Plant Cell Rep ; 24(6): 366-73, 2005 Aug.
Article in English | MEDLINE | ID: mdl-15789205

ABSTRACT

Drought treatment induces the accumulation of dcTLP, which is similar in structure to the thaumatin-like proteins (TLPs) found in the embryogenic calli, seedlings, and mature plants of carrot (Daucus carota). We isolated a full-length dcTLP cDNA clone from carrot and characterized the 5' upstream sequences. The coding region of dcTLP consisted of 645 nucleotides; the theoretical pI value was 4.9, and its molecular weight was approximately 22 kDa. The production of dcTLP transcripts in the seedlings increased dramatically with dehydration treatment but was not affected by abscisic acid (ABA), salicylic acid, or jasmonic acid. The expression patterns of dcTLP mRNA at different developmental stages and in response to a variety of signal molecules was analyzed using reverse transcriptase-PCR and promoter analysis with fused genes of 0.5-kb 5' upstream sequences in which beta-glucuronidase (GUS) reporter genes (gus) were established. The induction of dcTLP was found to be highly specific to drought stress in the embryogenic calli, seedlings, and mature plants. Our results suggest that this new isoform of TLP that has been isolated from carrot is a drought-specific, ABA-independent, non-organ-specific, and non-developmental-stage-specific protein.


Subject(s)
Daucus carota/genetics , Daucus carota/metabolism , Dehydration/metabolism , Plant Proteins/metabolism , Amino Acid Sequence/genetics , Arabidopsis Proteins/genetics , Base Sequence/genetics , DNA, Complementary/analysis , DNA, Complementary/genetics , Daucus carota/growth & development , Dehydration/genetics , Gene Expression Regulation, Plant/drug effects , Gene Expression Regulation, Plant/genetics , Genes, Reporter/genetics , Indoleacetic Acids/metabolism , Indoleacetic Acids/pharmacology , Molecular Sequence Data , Phylogeny , Plant Proteins/genetics , Plant Proteins/isolation & purification , Promoter Regions, Genetic/genetics , RNA, Messenger/drug effects , RNA, Messenger/metabolism , Seedlings/drug effects , Seedlings/genetics , Seedlings/metabolism , Sequence Homology, Amino Acid
9.
Cell Signal ; 12(9-10): 649-58, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11080617

ABSTRACT

Several studies have suggested that morphogenesis and patterning in hydra are regulated through pathways involving protein kinase C (PKC). Nevertheless, the complete signal system for regeneration in hydra is still not completely understood. Using inhibitors of different signalling pathways we are dissecting this system. We found that sphingosine (2 microM), staurosporine (0.1 microM), PP1/AGL1872 (1 microM) and H7 (25 microM) were able to inhibit head but not foot regeneration. The inhibition was reversible. When the inhibitor was replaced with hydra medium the animals continue their regeneration in a normal way. The exception was PP1/AGL1872, in this case the animals regenerated only one or two tentacles. These results imply that head and foot regeneration are independent processes and they are not directly related as has been proposed. Sphingosine and PP1/AGL1872 inhibit the transcription of ks1, an early regeneration gene, at 24 and 48 h of treatment. Sphingosine 2 microM arrested the cells on the G1 phase of the cell cycle, but 1 microM of PP1/AGL1872 did not. The regeneration was not affected if the animals were exposed to inhibitors of human growth factor receptors. We propose that head regeneration in hydra may be regulated at least by two pathways, one going through PKC and the other through Src. The first pathway could be related to cellular proliferation and the second one to cellular differentiation.


Subject(s)
Carrier Proteins/pharmacology , Hydra/physiology , Intracellular Signaling Peptides and Proteins , 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine/pharmacology , Animals , Benzoquinones , Cell Cycle/drug effects , Humans , Hydra/drug effects , Lactams, Macrocyclic , Protein Kinase C/antagonists & inhibitors , Quinones/pharmacology , Receptor Protein-Tyrosine Kinases/antagonists & inhibitors , Rifabutin/analogs & derivatives , Sphingosine/pharmacology , Staurosporine/pharmacology
10.
Development ; 127(5): 997-1005, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10662639

ABSTRACT

During the course of a systematic screening of peptide signaling molecules in Hydra a novel peptide, Hym-355 (FPQSFLPRG-NH(2)), was identified. A cDNA encoding the peptide was isolated and characterized. Using both in situ hybridization and immunohistochemistry, Hym-355 was shown to be expressed in neurons and hence is a neuropeptide. The peptide was shown to specifically enhance neuron differentiation throughout the animal by inducing interstitial cells to enter the neuron pathway. Further, co-treatment with a PW peptide, which inhibits neuron differentiation, nullified the effects of both peptides, suggesting that they act in an antagonistic manner. This effect is discussed in terms of a feedback mechanism for maintaining the steady state neuron population in Hydra.


Subject(s)
Hydra/physiology , Nervous System Physiological Phenomena , Neurons/cytology , Neuropeptides/physiology , Amino Acid Sequence , Animals , Base Sequence , Cell Differentiation , Hydra/cytology , Hydra/genetics , Mitotic Index , Molecular Sequence Data , Nervous System/cytology , Neurons/physiology , Neuropeptides/genetics , Protein Sorting Signals/chemistry
11.
Diabetes Technol Ther ; 1(1): 29-37, 1999.
Article in English | MEDLINE | ID: mdl-11475301

ABSTRACT

New and emerging capillary blood sampling technologies for self-monitoring of blood glucose (SMBG) are reviewed for their impact on factors pertaining to users such as pain, and from the standpoint of skin physiology and technical feasibility. Innovative blood sampling techniques based on lancets for skin penetration on nonfinger (alternate) sites such as the forearm seem to be virtually painless, convenient and cost effective as compared to other methods such as laser-based perforation of fingertips. Alternate site blood sampling with new lancet devices appears not only medically sound but also technically practical and user-friendly. It is anticipated that alternate site blood sampling techniques would improve compliance rate and, consequently, outcome of treatment for patients with diabetes.


Subject(s)
Blood Glucose Self-Monitoring/methods , Blood Glucose/analysis , Blood Specimen Collection/instrumentation , Blood Specimen Collection/methods , Capillaries , Diabetes Mellitus/blood , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 2/blood , Equipment Design , Fingers/blood supply , Humans , Pain , Patient Compliance
12.
FEBS Lett ; 439(1-2): 31-4, 1998 Nov 13.
Article in English | MEDLINE | ID: mdl-9849871

ABSTRACT

Hym-176 (APFIFPGPKVamide) is a novel myoactive neuropeptide which was identified in systematic screening of signaling peptides in Hydra magnipapillata. By using PCR and library screening, we cloned and sequenced a full length cDNA which encoded a preprohormone of Hym-176. In the preprohormone, a typical signal sequence, one copy of Hym-176 precursor peptide and one copy of precursor sequence of another novel peptide, Hym-357 (KPAFLFKGYKPamide), were detected. In situ hybridization analysis revealed a strong signal in peduncle neurons. Signals were also detected, though weaker, in neurons in the gastric region and around the mouth. No signals were detected in the two extremities of the body, tentacles and basal disk. The expression pattern is correlated with the distribution of Hym-176 and its myoactive function.


Subject(s)
Hydra/genetics , Neuropeptides/genetics , Amino Acid Sequence , Animals , Base Sequence , Cloning, Molecular , DNA, Complementary/analysis , Gene Expression , Hormones/genetics , Hormones/metabolism , Hydra/chemistry , Hydra/metabolism , In Situ Hybridization , Molecular Sequence Data , Neuropeptides/biosynthesis , Neuropeptides/chemistry , Protein Precursors/biosynthesis , Protein Precursors/chemistry , Protein Precursors/genetics
13.
FEMS Microbiol Lett ; 166(1): 9-13, 1998 Sep 01.
Article in English | MEDLINE | ID: mdl-9741079

ABSTRACT

Sisomicin binding sites are located in the cell wall. They are the carboxyl groups of peptidoglycans, which are major components of the cell wall. The carboxyl groups have negative charges which can bind the positively charged amino groups of sisomicin. When the negative charges of the carboxyl groups of the peptidoglycans are changed to neutral or positive charges, sisomicin does not bind to the cell wall. Magnesium ions bind to the cell wall in competition with sisomicin, and have a weak affinity for the cell wall binding sites compared with sisomicin. The binding molar ratio of sisomicin to magnesium ions was approximately 1 to 10.


Subject(s)
Anti-Bacterial Agents/metabolism , Micromonospora/metabolism , Sisomicin/metabolism , Anti-Bacterial Agents/chemistry , Binding Sites , Binding, Competitive , Cell Wall/chemistry , Cell Wall/metabolism , Electrochemistry , Hydrogen-Ion Concentration , Magnesium/metabolism , Sisomicin/chemistry
14.
Biochem Biophys Res Commun ; 248(3): 584-90, 1998 Jul 30.
Article in English | MEDLINE | ID: mdl-9703970

ABSTRACT

During the course of a systematic non-targeting screening of peptide signal molecules in Hydra, we identified a novel myoactive neuropeptide called Hym-176. The primary structure of Hym-176 was determined to be APFIFPGPKVamide. It specifically and reversibly induced contraction of the ectodermal muscle of the hydra body column in vivo. However, it had no effect on the ectodermal muscle of the tentacles. The structure-activity relationship analysis showed that the sequence of FIFPGPKVamide is a minimal requirement for the myoactivity. Removal of an amide group from the C-terminus completely abolished the activity. By using the antibody specific to Hym-176, the tissue localization of the peptide in hydra was determined immunohistochemically. The intense immunoreactivity was found in the peduncle nerve cells, indicating that Hym-176 is a neuropeptide.


Subject(s)
Hydra/physiology , Muscle Contraction/drug effects , Muscles/physiology , Neuropeptides/pharmacology , Amino Acid Sequence , Animals , Antibody Specificity , Cell Differentiation/drug effects , Cell Division/drug effects , Ectoderm/cytology , Ectoderm/drug effects , Ectoderm/physiology , Enzyme-Linked Immunosorbent Assay , Fluorescent Antibody Technique, Indirect , Hydra/drug effects , Muscle Contraction/physiology , Muscles/cytology , Muscles/drug effects , Neuropeptides/analysis , Neuropeptides/chemistry , Rabbits
15.
Alcohol Clin Exp Res ; 21(6): 953-6, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9309300

ABSTRACT

Mitochondrial aldehyde dehydrogenase (ALDH2) is mainly responsible for the oxidation of acetaldehyde generated during alcohol oxidation in vivo. Cytochrome P-4502E1 (CYP2E1), a liver microsomal enzyme, also metabolizes acetaldehyde and ethanol. Genetic polymorphism of ALDH2 and CYP2E1 was investigated among 481 Korean adults. A new restriction fragment-length polymorphism method was developed to determine the genotype of the ALDH2 alleles. This method proved to be simpler and faster than the hybridization method using allele-specific oligonucleotide probes and polymerase chain reaction-directed mutagenesis. The allele frequencies of ALDH2(1) and ALDH2(2) were 0.840 and 0.160, respectively. This allele frequency of ALDH2(2) is less than in Japanese people. Genetic polymorphism of CYP2E1 was investigated using polymerase chain reaction and restriction fragment-length polymorphism. The estimated allele frequencies for c1 and c2 were 0.808 and 0.192.


Subject(s)
Aldehyde Dehydrogenase/genetics , Cytochrome P-450 CYP2E1/genetics , Genotype , Mitochondria, Liver/enzymology , Polymorphism, Genetic/genetics , Adult , Aldehyde Dehydrogenase, Mitochondrial , Base Sequence/genetics , Ethanol/pharmacokinetics , Gene Frequency , Genetics, Population , Humans , Introns/genetics , Korea , Molecular Sequence Data , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length
16.
Neurology ; 49(2): 601-3, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9270606

ABSTRACT

Hereditary motor-sensory neuropathy type III (HMSN III) (Dejerine-Sottas disease) is a severe demyelinating neuropathy that is traditionally considered autosomal recessive. We report a father and daughter diagnosed with HMSN III by clinical, electrophysiologic, and pathologic criteria, thus showing that it may be transmitted in an autosomal dominant fashion in selected families.


Subject(s)
Genes, Dominant , Hereditary Sensory and Motor Neuropathy/genetics , Adolescent , Electrophysiology , Female , Hereditary Sensory and Motor Neuropathy/pathology , Hereditary Sensory and Motor Neuropathy/physiopathology , Humans , Male , Middle Aged , Pedigree
17.
Cancer Res ; 51(24): 6529-38, 1991 Dec 15.
Article in English | MEDLINE | ID: mdl-1742726

ABSTRACT

The bcl2 protooncogene was originally discovered because of its involvement in t(14;18) chromosomal translocations frequently found in non-Hodgkin's lymphomas. The expression of this gene is reported to be highly tissue specific, with bcl2 mRNAs being readily detectable only in hematolymphoid tissues and brain. To explore the possible involvement of bcl2 in neural tumors, we surveyed a variety of tumor cell lines for the presence of the p26-BCL2 protein by immunoprecipitation and immunoblotting methods. Very high levels of BCL2 protein were found in three of nine neuroblastoma (NB) cell lines examined; these levels of p26-BCL2 were comparable to lymphoma cell lines that contain a t(14;18). Despite the impressive relative amounts of BCL2 protein, however, no structural alterations or changes in the methylation status of bcl2 genes were detected in these NB cell lines by conventional Southern blotting. Of the other NB cell lines surveyed, three contained intermediate levels of BCL2 and another three cell lines had little or no detectable BCL2 protein, raising the possibility that determination of relative levels of BCL2 protein may help to segregate neuroblastomas into groups with different biological and clinical characteristics. BCL2 protein levels were not influenced by induction of neuronal differentiation with nerve growth factor in two of the two cell lines examined [SH-SY5Y (high BCL2); GICAN (low BCL2)] and did not correlate with N-MYC gene amplification or expression of nerve growth factor receptors. NB cell lines that contained little or no detectable BCL2 protein, however, tended to contain significant proportions of flat epithelioid cells, whereas bcl2-expressing cell lines were composed primarily of neuronal-like cells, suggesting that expression of this protooncogene correlates with the differentiation characteristics of these tumor cell lines. In addition to NBs, lower levels of BCL2 protein were also found in a variety of other neural crest-derived tumors and tumor cell lines, including some neuroepitheliomas, Ewing's sarcomas, neurofibromas, and melanomas. With regard to tumors of central nervous system origin, bcl2 expression was absent from most medulloblastomas but was detected at moderate to low levels in a retinoblastoma and some glioblastoma multiforme cell lines. Taken together, these findings imply that bcl2 protooncogene expression is differentially regulated within the various lineages of cells that give rise to the nervous system.


Subject(s)
Nervous System Neoplasms/genetics , Neuroblastoma/genetics , Proto-Oncogene Proteins/genetics , Proto-Oncogenes , Blotting, Southern , Blotting, Western , Cell Death , Gene Expression , Humans , Precipitin Tests , Proto-Oncogene Proteins/immunology , Proto-Oncogene Proteins c-bcl-2 , Tumor Cells, Cultured
18.
Cell Growth Differ ; 2(5): 235-43, 1991 May.
Article in English | MEDLINE | ID: mdl-1888699

ABSTRACT

The c-raf-1 protooncogene encodes a p72-74 serine/threonine-specific kinase that has been implicated in growth factor-mediated signal transduction and malignant transformation. Here, we compared the effects of Ha-c-ras and v-src oncogenes on the regulation of p72-74 RAF-1 kinase in NIH3T3 cells. In both serum-starved and platelet-derived growth factor-treated v-src-transformed cells, the RAF-1 kinase was constitutively activated, displaying characteristic retarded mobility in electrophoretic gels and elevated activity in in vitro kinase assays. In contrast, the RAF-1 protein from quiescent ras-transformed cells did not exhibit constitutively shifted gel mobility or elevated kinase activity but did respond normally with regard to platelet-derived growth factor- and phorbol myristate acetate-induced changes in p72-74 RAF-1 phosphorylation and kinase activity. 3T3 cells transformed by ras, however, contained elevated levels of p72-74 RAF-1 protein (as determined by immunoblotting), suggesting an indirect influence on this kinase. Quantitative differences in the levels and subcellular distribution of immunodetectable protein kinase C enzymes did not account for the differences between src- and ras-transformed 3T3 cells with regard to regulation of the RAF kinase. These findings in serum-deprived 3T3 cells demonstrate that expression of a ras oncogene can be insufficient for full activation of the p72-74 RAF-1 kinase, implying necessity for an additional growth factor-mediated stimulus.


Subject(s)
Proto-Oncogene Proteins/metabolism , Animals , Cell Line , Cell Membrane/enzymology , Cell Transformation, Neoplastic/metabolism , Genes, src , In Vitro Techniques , Mice , Molecular Weight , Oncogene Protein p21(ras)/physiology , Oncogene Protein pp60(v-src)/physiology , Phosphoproteins/metabolism , Phosphorylation , Platelet-Derived Growth Factor/pharmacology , Protein Kinase C/metabolism , Proto-Oncogene Proteins/chemistry , Proto-Oncogene Proteins c-raf , Tetradecanoylphorbol Acetate/pharmacology
19.
Oncogene ; 6(3): 455-60, 1991 Mar.
Article in English | MEDLINE | ID: mdl-2011401

ABSTRACT

The expression and function of several proto-oncogenes were examined in a human acute T cell leukemia line, JURKAT, during phorbol ester-induced terminal differentiation. Treating JURKAT cells with the phorbol ester tetradecanoyl phorbol acetate (TPA) inhibited their proliferation and induced expression of the gene for the interleukin 2 receptor alpha chain (IL2R-alpha), consistent with previous reports. In unstimulated proliferating JURKAT cells, high levels of C-MYC, N-RAS, and BCL2 mRNAs were found that diminished rapidly following TPA-induced cessation of growth. In contrast, accumulation of mRNAs for the C-FOS, C-JUN, and EGR-1 genes increased markedly in TPA-treated cells and preceded the induction of IL2R-alpha mRNA. Expression of C-MYB, C-RAF-1, C-LCK, C-FYN, and C-FGR proto-oncogenes was relatively unchanged. To explore directly the function of two of these protooncogenes in regulating the growth of JURKAT T cells, we stably transferred C-MYC and BCL2 expression plasmids into these cells. Despite sustained expression of C-MYC, BCL2, or the combination of these protooncogenes, TPA continued to inhibit JURKAT cell growth and to induce IL2R expression. Thus, although C-MYC and BCL2 proto-oncogene expression correlated with proliferation in TPA-treated JURKAT cells, continuous over-expression of even the combination of these oncogenes was insufficient for abrogating the effects of TPA in these leukemic T cells. Because human lymphoid malignancies frequently contain chromosomal translocations that deregulate the expression of C-MYC and BCL2, our findings could have relevance for attempts to induce terminal differentiation of leukemic cells by in vitro exposure of patients' bone marrow cells to phorbol esters.


Subject(s)
Gene Expression Regulation, Neoplastic/drug effects , Leukemia, T-Cell/genetics , Proto-Oncogene Proteins/genetics , Proto-Oncogenes , Tetradecanoylphorbol Acetate/pharmacology , Blotting, Northern , Humans , Leukemia, T-Cell/pathology , Nucleic Acid Hybridization , Plasmids , Proto-Oncogene Mas , RNA, Messenger/genetics , Receptors, Interleukin-2/genetics , Transfection , Tumor Cells, Cultured
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