RESUMO
⢠Premise of the study: Tropical regions have high species diversity, and polyploidization is a major mechanism of speciation in plants. However, few cases of natural polyploidy have been reported in tropical regions. Lippia alba, is a tropical, aromatic shrub with a wide distribution, extensive morphological plasticity, and several chemotypes. The species has long been recognized as a diploid with 2n = 30 chromosomes. Recently, two variations in chromosome number (2n = 60; 2n = 12-60) have been reported, suggesting the occurrence of polyploidy within the species.⢠Methods: Flow cytometry was used to investigate the genome size in 106 accessions from 14 Brazilian States. Conventional and molecular cytogenetic techniques and pollen viability analysis were employed to characterize each chromosome number observed.⢠Key results: The DNA 1C-value varied from 1.17 to 3.45 pg, showing a large variation in genome size. Five distinct chromosome numbers were observed (2n = 30, 38, 45, 60, 90); three are cytogenetically described here for the first time. The 5S rDNA signals varied proportionally according to each chromosome number, but 45S rDNA sites did not. High rates of meiotic irregularity were observed, mainly in cytotypes with higher chromosome numbers.⢠Conclusions: The data provide new support for the occurrence of a polyploid series in Lippia alba. We provide a hypothesis for how this complex may have arisen. Other cryptic polyploid complexes may remain undiscovered in tropical regions.
Assuntos
Lippia/genética , Poliploidia , Brasil , Cromossomos de PlantasRESUMO
OBJECTIVE: To verify whether headaches (HAs) are associated with temporomandibular disorders (TMD) in young Brazilian adolescents. METHODS: From a population sample, 3117 public school children (12 to 14 y) were randomly invited to participate in this study. TMD was assessed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I, in addition to questions #3, #4, and #14 of Axis II history questionnaire. HAs were investigated with question #18 of RDC/TMD Axis II. Chronic TMD pain was considered as pain that has persisted for 6 months or more, as proposed by the International Association for the Study of Pain. The statistical analysis consisted of χ tests, odds ratio (OR), and logistic regression models, adopting a significance level of 5%. RESULTS: The sample included 1307 individuals (a response rate of 41.93%), and 56.8% (n=742) were girls. Overall, 330 adolescents (25.2%) were diagnosed with painful TMD and 595 (45.5%) presented with HAs. Individuals presenting with HAs were more likely to present painful TMD (OR=4.94; 95% confidence interval [CI], 3.73-6.54, P<0.001), especially combined muscle and joint painful TMD (OR=7.58; 95% CI, 4.77-12.05, P<0.001). HAs also increased the risk to a higher magnitude for chronic TMD pain (OR=6.12; 95% CI, 4.27-8.78, P<0.0001). All estimated ORs remained essentially unchanged after adjusting for sex. DISCUSSION: HAs were a potential risk factor for TMD in adolescents, and the risk was particularly higher for painful and chronic TMD. When HAs are present in young adolescents, a complete examination is strongly recommended with regard to the presence of painful TMD, and vice versa.
Assuntos
Cefaleia/complicações , Transtornos da Articulação Temporomandibular/complicações , Adolescente , Brasil , Distribuição de Qui-Quadrado , Criança , Feminino , Humanos , Masculino , Inquéritos e QuestionáriosRESUMO
OBJECTIVES: Temporomandibular disorders (TMDs) are considered to be comorbid with headaches. Earlier population studies have suggested that TMD may also be a risk factor for migraine progression. If that is true, TMD should be associated with specific headache syndromes (eg, migraine and chronic migraine), but not with headaches overall. Accordingly, our aim was to explore the relationship between TMD subtypes and severity with primary headaches in a controlled clinical study. METHODS: The sample consisted of 300 individuals. TMDs were assessed using the Research Diagnostic Criteria for TMD, and primary headache was classified according to International Classification for Headache Disorders-2. Univariate and multivariate models assessed headache diagnoses and frequency as a function of the parameters of TMD. RESULTS: Relative to those without TMD, individuals with myofascial TMD were significantly more likely to have chronic daily headaches (CDHs) [relative risk (RR)=7.8; 95% confidence interval (CI), 3.1-19.6], migraine (RR=4.4; 95% CI, 1.7-11.7), and episodic tension-type headache (RR=4.4; 95% CI, 1.5-12.6). Grade of TMD pain was associated with increased odds of CDH (P<0.0001), migraine (P<0.0001), and episodic tension-type headache (P<0.05). TMD severity was also associated with headache frequency. In multivariate analyses, TMD was associated with migraine and CDH (P=0.001). Painful TMD (P=0.0034) and grade of TMD pain (P<0.001) were associated with headache frequency. DISCUSSION: TMD, TMD subtypes, and TMD severity are independently associated with specific headache syndromes and with headache frequency. This differential association suggests that the presence of central facilitation of nociceptive inputs may be of importance, as positive association was observed only when muscular TMD pain was involved.
Assuntos
Cefaleia/diagnóstico , Cefaleia/epidemiologia , Transtornos da Articulação Temporomandibular/diagnóstico , Transtornos da Articulação Temporomandibular/epidemiologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Medição da Dor , Fatores de Risco , Fatores Sexuais , Adulto JovemRESUMO
AIMS: To assess the prevalence of primary headaches (HA) in adults with temporomandibular disorders (TMD) who were assessed in a specialty orofacial pain clinic, as well as in controls without TMD. METHODS: The sample consisted of 158 individuals with TMD seen at a university-based specialty clinic, as well as 68 controls. The Research Diagnostic Criteria for TMD were used to diagnose the TMD patients. HAs were assessed using a structured interview and classified according to the Second Edition of the International Classification for Headache Disorders. Data were analyzed by chi-square tests with a significance level of 5% and odds ratio (OR) tests with a 95% confidence interval (CI). RESULTS: HAs occurred in 45.6% of the control group (30.9% had migraine and 14.7% had tension-type headache [TTH]) and in 85.5% of individuals with TMD. Among individuals with TMD, migraine was the most prevalent primary HA (55.3%), followed by TTH (30.2%); 14.5% had no HA. In contrast to controls, the odds ratio (OR) for HA in those with TMD was 7.05 (95% confidence interval [CI] = 3.65-13.61; P = .000), for migraine, the OR was 2.76 (95% CI = 1.50-5.06; P = .001), and for TTH, the OR was 2.51 (95% CI = 1.18-5.35; P = .014). Myofascial pain/arthralgia was the most common TMD diagnosis (53.2%). The presence of HA or specific HAs was not associated with the time since the onset of TMD (P = .714). However, migraine frequency was positively associated with TMD pain severity (P = .000). CONCLUSION: TMD was associated with increased primary HA prevalence rates. Migraine was the most common primary HA diagnosis in individuals with TMD.