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2.
Public Health ; 166: 121-127, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30476780

ABSTRACT

OBJECTIVES: The objectives of this study are to (1) explore physical and verbal abuse experience, perpetrators of abuse and abuse reporting behaviours of Filipino foreign domestic helpers in Hong Kong and (2) examine associations between their abuse experience and depression level. STUDY DESIGN: A cross-sectional survey METHODS: We purposively sampled participants at the Statue Square of Hong Kong on three Sunday afternoons between June and August 2017. Using a self-administered questionnaire, measures include sociodemographic and housing environment variables, physical and verbal abuse experience and depression level measured using the Depression Subscale of Depression Anxiety Stress Scale 21 (DASS-21-D). Multiple linear regression was performed to identify factors associated with the DASS-21-D score. RESULTS: The response rate was 86.1% and 105 participants completed the questionnaire. Overall, 20.5% and 34.4% had experienced physical and verbal abuse, respectively, in the past 12 months. Majority of perpetrators were female employers and children. Meanwhile, 16.7% of the abuse victims did not report their cases. Among those who reported, only a few (19.4%) reported their cases to formal organizations (agency and police). Factors significantly associated with the DASS-21-D score include physical abuse (unstandardized beta coefficient [B] = 1.68, 95% confidence interval [95% CI] = 0.12-3.34), verbal abuse (B = 1.58, 95% CI = 0.16-3.00), non-disclosure of physical abuse experience (B = 5.68, 95% CI = 0.18-11.18) and living space satisfaction (B = -1.50, 95% CI = -2.12 to -0.88). CONCLUSIONS: Physical and verbal abuse among foreign domestic workers in Hong Kong were underreported to formal organizations and were associated with depression. Legislative enforcement of a comprehensive abuse reporting mechanism and mental health service should be considered.


Subject(s)
Caregivers/psychology , Depression/epidemiology , Emigrants and Immigrants/psychology , Physical Abuse/psychology , Verbal Behavior , Adult , Caregivers/statistics & numerical data , Cross-Sectional Studies , Emigrants and Immigrants/statistics & numerical data , Female , Hong Kong/epidemiology , Humans , Male , Philippines/ethnology , Physical Abuse/statistics & numerical data , Surveys and Questionnaires , Young Adult
4.
Public Health ; 158: 64-65, 2018 05.
Article in English | MEDLINE | ID: mdl-29709249
5.
Epidemiol Infect ; 140(10): 1904-19, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22142566

ABSTRACT

With economic development, non-communicable diseases replace infectious diseases as the leading cause of death; how such transition occurs for infectious diseases with long latency has rarely been considered. We took advantage of a Chinese population with rapid economic development in the mid-20th century to study changing patterns of infection-related cancers. We used sex-specific Poisson regression to estimate age, period and cohort effects on adult deaths 1976-2005 from eight infection-related cancers in Hong Kong. Cervical, head and neck, and oesophageal cancers, associated with sexually transmitted infections, decreased for the first birth cohorts with sexual debut in a more developed environment. Leukaemia and non-Hodgkin's lymphoma, associated with vertically transmitted infections, decreased for the first cohorts born into a more developed environment. Birth cohort patterns were unclear for nasopharyngeal, stomach and liver cancers. Mortality rates for cancers related to early infections may depend on population history, with delayed reductions for some infection-related cancers.


Subject(s)
Economic Development/trends , Neoplasms/epidemiology , Sexually Transmitted Diseases/complications , Adult , Aged , Aged, 80 and over , Asian People , Female , Hong Kong/epidemiology , Humans , Male , Middle Aged
6.
Res Rep Health Eff Inst ; (154): 377-418, 2010 Nov.
Article in English | MEDLINE | ID: mdl-21446215

ABSTRACT

BACKGROUND: In recent years, Asia has experienced rapid economic growth and a deteriorating environment caused by the increasing use of fossil fuels. Although the deleterious effects of air pollution from fossil-fuel combustion have been demonstrated in many Western nations, few comparable studies have been conducted in Asia. Time-series studies of daily mortality in Asian cities can contribute important new information to the existing body of knowledge about air pollution and health. Not only can these studies verify important health effects of air pollution in local regions in Asia, they can also help determine the relevance of existing air pollution studies to mortality and morbidity for policymaking and environmental controls. In addition, the studies can help identify factors that might modify associations between air pollution and health effects in various populations and environmental conditions. Collaborative multicity studies in Asia-especially when designed, conducted, and analyzed using a common protocol-will provide more robust air pollution effect estimates for the region as well as relevant, supportable estimates of local adverse health effects needed by environmental and public-health policymakers. SPECIFIC OBJECTIVES: The Public Health and Air Pollution in Asia (PAPA*) project, sponsored by the Health Effects Institute, consisted of four studies designed to assess the effects of air pollution on mortality in four large Asian cities, namely Bangkok, in Thailand, and Hong Kong, Shanghai, and Wuhan, in China. In the PAPA project, a Common Protocol was developed based on methods developed and tested in NMMAPS, APHEA, and time-series studies in the literature to help ensure that the four studies could be compared with each other and with previous studies by following an established protocol. The Common Protocol (found at the end of this volume) is a set of prescriptive instructions developed for the studies and used by the investigators in each city. It is flexible enough to allow for adjustments in methods to optimize the fit of health-effects models to each city's data set. It provides the basis for generating reproducible results in each city and for meta-estimates from combined data. By establishing a common methodology, factors that might influence the differences in results from previous studies can more easily be explored. Administrative support was provided to ensure that the highest quality data were used in the analysis. It is anticipated that the PAPA results will contribute to the international scientific discussion of how to conduct and interpret time-series studies of air pollution and will stimulate the development of high-quality routine systems for recording daily deaths and hospital admissions for time-series analysis. METHODS: Mortality data were retrieved from routine databases with underlying causes of death coded using the World Health Organization (WHO) International Classification of Diseases, 9th revision or 10th revision (ICD-9, ICD-10). Air quality measurements included nitrogen dioxide (NO2), sulfur dioxide (SO2), particulate matter with aerodynamic diameter < or = 10 microm (PM10), and ozone (O3) and were obtained from several fixed-site air monitoring stations that were located throughout the metropolitan areas of the four cities and that met the standards of procedures for quality assurance and quality control carried out by local government units in each city. Using the Common Protocol, an optimized core model was established for each city to assess the effects of each of the four air pollutants on daily mortality using generalized linear modeling with adjustments for time trend, seasonality, and other time-varying covariates by means of a natural-spline smoothing function. The models were adjusted to suit local situations by correcting for influenza activity, autocorrelation, and special weather conditions. Researchers in Hong Kong, for example, used influenza activity based on frequency of respiratory mortality; researchers in Hong Kong and Shanghai used autoregressive terms for daily outcomes at lag days; and researchers in Wuhan used additional smoothing for periods with extreme weather conditions. RESULTS AND DISCUSSION: For mortality due to all natural (nonaccidental) causes at all ages, the effects of air pollutants per 10-microg/m3 increase in concentration was found to be higher in Bangkok than in the three Chinese cities, with the exception of the effect of NO2 in Wuhan. The magnitude of the effects for cardiovascular and respiratory mortality were generally higher than for all natural mortality at all ages. In addition, the effects associated with PM10 and O3 in all natural, cardiovascular; and respiratory mortality were found to be higher in Bangkok than in the three Chinese cities. The explanation for these three findings might be related to consistently higher daily mean temperatures in Bangkok, variations in average time spent outdoors by the susceptible populations, and the fact that less air conditioning is available and used in Bangkok than in the other cities. However, when pollutant concentrations were incorporated into the excess risk estimates through the use of interquartile range (IQR), the excess risk was more comparable across the four cities. We found that the increases in effects among older age groups were greater in Bangkok than in the other three cities. After excluding data on extremely high concentrations of PM10 in Bangkok, the effect estimate associated with PM10 concentrations decreased in Bangkok (suggesting a convex relationship between risk and PM10, where risk levels off at high concentrations) instead of increasing, as it did in the other cities. This leveling off of effect estimates at high concentrations might be related to differences in vulnerability and exposure of the population to air pollution as well as to the sources of the air pollutant. IMPLICATIONS OF THE STUDY: The PAPA project is the first coordinated Asian multicity air pollution study ever published; this signifies the beginning of an era of cooperation and collaboration in Asia, with the development of a common protocol for coordination, data management, and analysis. The results of the study demonstrated that air pollution in Asia is a significant public health burden, especially given the high concentrations of pollutants and high-density populations in major cities. When compared with the effect estimates reported in the research literature of North America and Western Europe, the study's effect estimates for PM10 were generally similar and the effect estimates for gaseous pollutants were relatively higher. In Bangkok, however, a tropical city where total exposures to outdoor pollution might be higher than in most other cities, the observed effects were greater than those reported in the previous (i.e., Western) studies. In general, the results suggested that, even though social and environmental conditions across Asia might vary, it is still generally appropriate to apply to Asia the effect estimates for other health outcomes from previous studies in the West. The results also strongly support the adoption of the global air quality guidelines recently announced by WHO.


Subject(s)
Air Pollutants/toxicity , Air Pollution/adverse effects , Cardiovascular Diseases/mortality , Public Health , Respiratory Tract Diseases/mortality , Aged , Asia/epidemiology , Cardiovascular Diseases/chemically induced , Female , Humans , Male , Middle Aged , Nitrogen Dioxide/analysis , Nitrogen Dioxide/toxicity , Ozone/analysis , Ozone/toxicity , Particulate Matter/analysis , Particulate Matter/toxicity , Respiratory Tract Diseases/chemically induced , Sulfur Dioxide/analysis , Sulfur Dioxide/toxicity , Time Factors
7.
Neurosurgery ; 47(4): 827-32; discussion 832-3, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11014421

ABSTRACT

OBJECTIVE: In a patient older than 70 years, the decision to treat an intracranial aneurysm remains difficult whether it is ruptured or unruptured. We sought to review our institutional risks of treatment of such lesions in the context of the risks of rupture and its associated morbidity and mortality in this age group. METHODS: One hundred twenty-nine consecutive patients aged 70 years or older, who were treated at a single institution for an intracranial aneurysm, were retrospectively reviewed. Forty patients were treated for unruptured aneurysms, and 89 patients presented after subarachnoid hemorrhage. Seven additional patients in this age group who had solely intracavernous lesions, as well as one patient with a dolichoectatic fusiform basilar lesion, were excluded. Management outcomes were assessed using a modification of the Glasgow Outcome Scale, and additional physical and functional disability was assessed using the Barthel index and the Reintegration to Normal Living index. RESULTS: Six-month outcomes for the unruptured group were: excellent, 70%; good, 15%; fair, 5%; poor, 7.5%; and death (2.5%). Outcomes for all patients with ruptured lesions (including those not offered aggressive therapy) were: excellent, 34%; good, 9%; fair, 5.6%; poor, 3.4%; and death, 45%. Long-term follow-up was performed by questionnaire to assess physical and functional disability. Although physical disability (Barthel index) was similar among survivors, the Reintegration to Normal Living index, a global assessment of function, was significantly higher in patients with unruptured aneurysms (84.8 versus 70.1; P = 0.05), which highlights the disabling effects of hemorrhage. CONCLUSION: On the basis of an individual treatment center's management risks, annual aneurysmal rupture rates can be estimated that justify treatment in this difficult patient population. Despite recent controversy regarding aneurysmal hemorrhage rates, we think that symptomatic unruptured aneurysms should be treated and good results can be achieved, even in older patients.


Subject(s)
Aneurysm, Ruptured/therapy , Intracranial Aneurysm/therapy , Activities of Daily Living , Aged , Aged, 80 and over , Aneurysm, Ruptured/mortality , Aneurysm, Ruptured/physiopathology , Disability Evaluation , Female , Glasgow Coma Scale , Humans , Intracranial Aneurysm/mortality , Intracranial Aneurysm/physiopathology , Male , Retrospective Studies , Treatment Outcome
8.
J Virol ; 73(9): 7556-64, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10438845

ABSTRACT

Deletion of the gamma34.5 gene coding for virulence markedly reduces cytotoxicity mediated by herpes simplex virus type 1 (HSV-1) (J. M. Markert et al., Neurosurgery 32:597-603, 1993; N. S. Markovitz et al. , J. Virol. 71:5560-5569, 1997). To target lytic virulence to tumors, we have created a novel HSV-1 mutant, designated Myb34.5. This viral mutant is characterized by a deletion of the gene for infected cell polypeptide 6 (ICP6; also known as UL39 or ribonucleotide reductase) and of the two endogenous copies of the gamma34.5 gene (RL1) and by reintroduction of one copy of gamma34.5 under control of the E2F-responsive, cellular B-myb promoter. On direct intracerebral inoculation in BALB/c mice, the 50% lethal dose (LD(50)) for Myb34.5 was 2.7 x 10(7) PFU while that for HSVs with mutations in the gamma34.5 gene could not be technically achieved with available viral stocks and it was estimated as >1 x 10(7) PFU. The LD(50) for an HSV with a single defect in ICP6 function was 1.3 x 10(6) PFU. Conversely, Myb34.5's oncolytic efficacy against a variety of human glioma cells in culture and in vivo was enhanced compared to that of HSVs with gamma34.5 mutations, and in fact, it was comparable to that of the wild-type F strain and of viral mutants that possess a wild-type gamma34.5 gene. The characteristic shutoff of host protein synthesis, occurring after infection of human SK-N-SH neuroblastoma cells by gamma34.5 mutant viruses (J. Chou and B. Roizman, Proc. Natl. Acad. Sci. USA 89:3266-3270, 1992), was not present after infection with Myb34.5. There was an increase of almost 3 logarithmic units in the production of progeny virus in arrested fibroblasts compared to that in cycling fibroblasts infected with Myb34.5. These results suggest that transcriptional regulation of gamma34.5 by cell cycle-regulated promoters can be used to target HSV-1 virulence toward tumors while maintaining the desirable neuroattenuated phenotype of a gamma34.5 mutant.


Subject(s)
Antineoplastic Agents , Cell Cycle Proteins , DNA-Binding Proteins/genetics , Genes, Viral , Herpesvirus 1, Human/pathogenicity , Neurotoxins , Promoter Regions, Genetic , Trans-Activators/genetics , Viral Proteins/genetics , Viral Proteins/physiology , Animals , Cell Cycle , Chlorocebus aethiops , Gene Expression Regulation, Viral , Genetic Engineering , Glioma , Gliosarcoma , Herpesvirus 1, Human/genetics , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Neurons/cytology , Neurons/virology , Neurotoxins/genetics , Rats , Tumor Cells, Cultured , Vero Cells , Virulence
9.
Surg Oncol Clin N Am ; 7(3): 589-602, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9624219

ABSTRACT

Primary central nervous system tumors, consisting mainly of malignant gliomas, represent a unique system for the study of gene transfer techniques. Exogenous transgenes have been delivered using retroviral, adenoviral, and herpes simplex virus vectors. A number of strategies have been developed, including: (1) delivery of prodrug activating genes, (2) replacement of tumor suppressor genes, (3) cytokine-mediated enhancement of antitumor immune responses, and (4) antisense cDNA delivery to block the action of growth factors, cell cycle proteins, and drug resistance mechanisms. Efforts to disrupt the blood brain barrier may facilitate tumor gene delivery.


Subject(s)
Central Nervous System Neoplasms/therapy , Genetic Therapy , Central Nervous System Neoplasms/genetics , Cytokines , Genes, Tumor Suppressor , Humans
10.
Nat Biotechnol ; 16(5): 444-8, 1998 May.
Article in English | MEDLINE | ID: mdl-9592392

ABSTRACT

Herpes simplex viruses type 1 (HSV-1) with an inactivated viral ribonucleotide reductase (Hsrr, ICP6) were designed to target tumor cells with upregulated mammalian ribonucleotide reductase (mRR), an enzyme whose expression is regulated by the p16/pRB tumor suppressor pathway. A recombinant HSV-1 was generated by knock-out of Hsrr and insertion of the rat CYP2B1 transgene responsible for the bioactivation of the prodrugs, cyclophosphamide and ifosfamide. The mutant virus replicated selectively in rat and human tumor cells that express mRR. Addition of cyclophosphamide potentiated oncolytic effects against cultured tumor cells and subcutaneous tumor xenografts established in athymic mice.


Subject(s)
Antineoplastic Agents, Alkylating/pharmacology , Cyclophosphamide/pharmacology , Cytochrome P-450 CYP2B1/genetics , Gene Expression Regulation, Enzymologic/genetics , Herpesvirus 1, Human/genetics , Prodrugs/pharmacology , Animals , DNA, Viral/chemistry , Herpesvirus 1, Human/enzymology , Humans , Ifosfamide/pharmacology , Mice , Mice, Nude , Mutation , Rats , Recombinant Proteins/genetics , Ribonucleotide Reductases/chemistry , Ribonucleotide Reductases/genetics , Tumor Cells, Cultured , Up-Regulation/genetics , Virus Replication/drug effects , Virus Replication/genetics
11.
J Neuropathol Exp Neurol ; 52(1): 31-8, 1993 Jan.
Article in English | MEDLINE | ID: mdl-8381161

ABSTRACT

The p53 gene is a tumor suppressor gene involved in many common malignancies, including astrocytomas. Genetic analysis of the p53 gene and immunohistochemistry of the p53 protein have each been used to screen astrocytomas. To compare these methods, we performed immunohistochemistry with the monoclonal antibody PAb 1801 and single-strand conformational polymorphism (SSCP) with sequence analysis on 34 astrocytic tumors (WHO grades II, III and IV). Seven cases had detectable p53 protein and gene mutations, while twelve cases had neither detectable protein nor gene mutations. Four tumors had frameshift mutations in the p53 gene that were not revealed by immunohistochemistry. One tumor had a genetic polymorphism and no detectable p53 protein. Ten tumors had p53 protein accumulation but no mutations by SSCP; these cases may represent p53 mutations outside of the conserved exons or elevated levels of wild-type p53 protein. Thus, some p53 mutations are missed with PAb 1801 immunohistochemistry alone. p53 immunohistochemistry, however, may reveal p53 accumulation independent of mutations in the conserved portions of the gene. Finally, we suggest that glioblastomas with p53 mutations in the conserved region of the gene may be a subset that are more common in women and in younger patients.


Subject(s)
Astrocytoma/genetics , Brain Neoplasms/genetics , Glioblastoma/genetics , Mutation , Tumor Suppressor Protein p53/genetics , Adolescent , Adult , Aged , Amino Acid Sequence , Astrocytoma/chemistry , Astrocytoma/pathology , Brain Neoplasms/chemistry , Brain Neoplasms/pathology , Child , Codon , Exons , Female , Glioblastoma/chemistry , Glioblastoma/pathology , Humans , Immunohistochemistry , Male , Middle Aged , Molecular Sequence Data , Polymorphism, Genetic , Protein Conformation , Tumor Suppressor Protein p53/analysis
12.
Nucleic Acids Res ; 20(15): 4083-7, 1992 Aug 11.
Article in English | MEDLINE | ID: mdl-1508692

ABSTRACT

Mutations in the p53 gene are the most common genetic alterations observed in many inherited and sporadic forms of human cancer. Recent studies indicate that wild-type p53 may be involved in the regulation of gene expression. In the present report we examined the effect of p53 on the human c-fos promoter. Using a transient co-transfection assay we show that wild-type human p53, but not a transforming mutant of p53, negatively regulates the activity of the c-fos promoter in a dose-dependent manner. Promoter deletion analysis maps a sequence conferring p53 repression to the basal promoter region between nucleotides -53 and +42 relative to the cap site. In contrast, p53 strongly stimulates transcription when a sequence previously reported to bind p53 (TGCCT repeat) was inserted in front of the HSV-TK promoter driving CAT. These findings raise the question as to whether p53 may mediate its inhibitory effect on c-fos gene expression by interfering, directly or indirectly, with components of the basal transcriptional machinery.


Subject(s)
Down-Regulation/genetics , Genes, fos/genetics , Promoter Regions, Genetic/genetics , Proto-Oncogene Proteins c-fos/genetics , Tumor Suppressor Protein p53/genetics , Base Sequence , Genes, p53 , Molecular Sequence Data , Plasmids/genetics , Recombinant Fusion Proteins/genetics , Thymidine Kinase/genetics , Tumor Cells, Cultured
13.
J Neurosurg ; 77(2): 295-301, 1992 Aug.
Article in English | MEDLINE | ID: mdl-1320666

ABSTRACT

Although the loss of tumor suppressor genes and the activation of oncogenes have been established as two of the fundamental mechanisms of tumorigenesis in human cancer, little is known about the possible interactions between these two mechanisms. Loss of genetic material on chromosome 10 and amplification of the epidermal growth factor receptor (EGFR) gene are the most frequently reported genetic abnormalities in glioblastoma multiforme. In order to examine a possible correlation between these two genetic aberrations, the authors studied 106 gliomas (58 glioblastomas, 14 anaplastic astrocytomas, five astrocytomas, nine pilocytic astrocytomas, seven mixed gliomas, six oligodendrogliomas, two ependymomas, one subependymoma, one subependymal giant-cell astrocytoma, and three gangliogliomas) with Southern blot analysis for loss of heterozygosity on both arms of chromosome 10 and for amplification of the EGFR gene. Both the loss of genetic material on chromosome 10 and EGFR gene amplification were restricted to the glioblastomas. Of the 58 glioblastoma patients, 72% showed loss of chromosome 10 and 38% showed EGFR gene amplification. The remaining 28% had neither loss of chromosome 10 nor EGFR gene amplification. Without exception, the glioblastomas that exhibited EGFR gene amplification had also lost genetic material on chromosome 10 (p less than 0.001). This invariable association suggests a relationship between the two genetic events. Moreover, the presence of 15 cases of glioblastoma with loss of chromosome 10 but without EGFR gene amplification may further imply that the loss of a tumor suppressor gene (or genes) on chromosome 10 precedes EGFR gene amplification in glioblastoma tumorigenesis.


Subject(s)
Brain Neoplasms/genetics , Chromosomes, Human, Pair 10 , ErbB Receptors/genetics , Gene Amplification , Glioblastoma/genetics , Biomarkers, Tumor/genetics , DNA, Neoplasm/genetics , Genes, Tumor Suppressor , Humans
15.
Cancer Res ; 52(10): 2987-90, 1992 May 15.
Article in English | MEDLINE | ID: mdl-1349850

ABSTRACT

Loss of genetic material on the short arm of chromosome 17 is observed in approximately 40% of human astrocytomas (WHO grades II and III) and in approximately 30% of cases of glioblastoma multiforme (WHO grade IV). Previous studies of glioblastoma multiforme have shown that the p53 gene, located on the short arm of chromosome 17, is frequently mutated in these glioblastomas. To explore whether lower-grade astrocytomas are also associated with corresponding mutations of the p53 gene, we have investigated a series of 22 human astrocytomas of WHO grades II and III both for loss of heterozygosity on chromosome 17p and for p53 mutations. Mutations in the conserved regions of the p53 gene were identified by single strand conformation polymorphism analysis of exons 5, 6, 7, and 8 and were verified by direct DNA sequencing of the polymerase chain reaction products. p53 mutations were observed in 3 of 8 grade II astrocytomas and 4 of 14 grade II astrocytomas. In all 22 tumors, allelic loss of the short arm of chromosome 17 was investigated by restriction fragment length polymorphism analysis. One-half of the grade II astrocytomas (4 of 8) and grade III astrocytomas (7 of 14) exhibited allelic loss on chromosome 17p. Mutations in the p53 gene were exclusively observed in tumors with allelic loss on 17p. Our results show that p53 mutations are not restricted to glioblastoma multiforme and may be important in the tumorigenesis of lower-grade astrocytomas and that p53 mutations in lower-grade astrocytomas are associated with loss of chromosome 17p. These findings are consistent with a recessive mechanism of action of p53 in WHO grade II and III astrocytoma tumorigenesis.


Subject(s)
Alleles , Astrocytoma/genetics , Chromosome Deletion , Chromosomes, Human, Pair 17/physiology , Genes, p53/genetics , Astrocytoma/pathology , Base Sequence , Blotting, Southern , DNA, Single-Stranded/genetics , Exons/genetics , Heterozygote , Humans , Molecular Sequence Data , Mutation , Nucleic Acid Conformation , Polymorphism, Genetic , Polymorphism, Restriction Fragment Length
17.
Proc Natl Acad Sci U S A ; 87(14): 5435-9, 1990 Jul.
Article in English | MEDLINE | ID: mdl-2142531

ABSTRACT

von Recklinghausen neurofibromatosis (NF1) is a common hereditary disorder characterized by neural crest-derived tumors, particularly benign neurofibromas whose malignant transformation to neurofibrosarcomas can be fatal. The NF1 gene has been mapped to a small region of chromosome 17q, but neither the nature of the primary defect nor the mechanisms involved in tumor progression are understood. We have tested whether NF1 might be caused by the inactivation of a tumor suppressor gene on 17q, analogous to that on chromosome 22 in NF2, by searching for deletions of chromosome 17 in NF1-derived tumor specimens. Both neurofibrosarcomas from patients with "atypical" NF and 5 of 6 neurofibrosarcomas from NF1 patients displayed loss of alleles for polymorphic DNA markers on chromosome 17. However, the common region of deletion was on 17p and did not include the NF1 region of 17q. Since no loss of markers on chromosome 17 was observed in any of 30 benign tumors from NF1 patients, the 17p deletions seen in neurofibrosarcomas are probably associated with tumor progression and/or malignancy. This region contains a candidate gene for tumor progression, p53, which has recently been implicated in the progression of a broad array of human cancers. In a preliminary search for p53 aberrations by direct sequencing of polymerase chain reaction-amplified DNA from 7 neurofibrosarcomas, 2 tumors that contained point mutations in exon 4 of the p53 gene were found, suggesting a role for this gene in at least some neurofibrosarcomas. Thus the formation of malignant neurofibrosarcomas may result from several independent genetic events including mutation of the NF1 gene, whose mechanism of tumorigenesis remains uncertain, and subsequent loss of a "tumor suppressor" gene on 17p, most likely p53.


Subject(s)
Chromosome Deletion , Chromosomes, Human, Pair 17 , Mutation , Neoplasm Proteins/genetics , Neurofibroma/genetics , Neurofibromatosis 1/genetics , Oncogene Proteins/genetics , Phosphoproteins/genetics , Base Sequence , Chromosome Mapping , DNA, Neoplasm/genetics , DNA, Neoplasm/isolation & purification , Genetic Carrier Screening , Genetic Markers/analysis , Humans , Molecular Sequence Data , Oligonucleotide Probes , Polymerase Chain Reaction , Suppression, Genetic , Tumor Suppressor Protein p53
18.
Proc Natl Acad Sci U S A ; 86(18): 7186-90, 1989 Sep.
Article in English | MEDLINE | ID: mdl-2571151

ABSTRACT

Astrocytomas, including glioblastoma multiforme, represent the most frequent and deadly primary neoplasms of the human nervous system. Despite a number of previous cytogenetic and oncogene studies primarily focusing on malignant astrocytomas, the primary mechanism of tumor initiation has remained obscure. The loss or inactivation of "tumor suppressor" genes are thought to play a fundamental role in the development of many human cancers. Thus, we have analyzed astrocytomas of various histological malignancy grades with polymorphic DNA markers to search for specific chromosomal deletions potentially pointing to loci containing tumor suppressor genes. Loss of constitutional heterozygosity indicating chromosomal loss or deletions was most frequently seen for markers on the short arm of chromosome 17 in 50% of the informative tumors (5 of 10 informative cases) and, to a lesser extent, for markers on chromosomes 1 and 10. Deletions on chromosome 17p were seen in both low-grade and high-grade malignant astrocytomas, suggesting that this chromosome may contain a tumor suppressor gene associated with the early events in tumorigenesis. The common region of deletions on the short arm of chromosome 17 is, therefore, clearly distinct from the gene causing von Recklinghausen neurofibromatosis (NF1), a tumor syndrome associated with glial tumors that maps to the long arm of chromosome 17. The search for progressively smaller deletions on chromosome 17p in astrocytomas may be the way to clone and characterize this locus, thus leading to insights into normal and abnormal growth and differentiation of glial cells.


Subject(s)
Astrocytoma/genetics , Chromosomes, Human, Pair 17 , Astrocytoma/pathology , Chromosome Mapping , DNA, Neoplasm/isolation & purification , Genetic Carrier Screening , Humans , Leukocytes/cytology , Polymorphism, Restriction Fragment Length
19.
Neurosci Lett ; 83(1-2): 13-9, 1987 Dec 16.
Article in English | MEDLINE | ID: mdl-2831475

ABSTRACT

Combined retrograde transport and immunocytochemical methods were used to determine whether neurons in the Edinger-Westphal complex (EW) that project to the spinal cord also demonstrate corticotropin-releasing factor-like immunoreactivity (CRF-LI). Large injections of horseradish peroxidase (HRP) into cervical spinal cord retrogradely labeled cells throughout the extent of the EW complex. Most retrogradely labeled EW neurons also exhibited CRF-LI, evidence that EW is the origin of a direct CRF-containing pathway which links the rostral mesencephalon with spinal cord.


Subject(s)
Corticotropin-Releasing Hormone/metabolism , Oculomotor Nerve/physiology , Spinal Cord/physiology , Synaptic Transmission , Animals , Cats , Horseradish Peroxidase , Immunohistochemistry , Neurons/metabolism , Oculomotor Nerve/cytology , Oculomotor Nerve/metabolism
20.
Brain Res ; 403(1): 172-6, 1987 Feb 10.
Article in English | MEDLINE | ID: mdl-3548886

ABSTRACT

Electrical stimulation of the midbrain periaqueductal gray region (PAG) suppresses the tooth pulp-evoked jaw-opening reflex (TP-JOR). In the present study the pathways that mediate this suppression were investigated by placing brainstem lesions in lightly anesthetized cats. Parasagittal lesions that interrupted the afferent and efferent connections of the medullary and pontine raphe nuclei attenuated (but did not abolish) suppression of the TP-JOR evoked by PAG stimulation. This result provides further evidence that medial brainstem structures partially mediate the effects of PAG stimulation in the trigeminal system.


Subject(s)
Brain Stem/physiology , Jaw/physiology , Neural Inhibition , Periaqueductal Gray/physiology , Reflex/physiology , Animals , Cats , Electric Stimulation , Neural Pathways/physiology , Stereotaxic Techniques
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