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1.
BMJ Open ; 13(11): e068333, 2023 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-38035743

RESUMO

OBJECTIVES: In the context of the COVID-19 pandemic, general practitioners (GPs) continue to face unprecedented challenges that affect their mental health. However, few studies have assessed the mental health status of GPs. This study aimed to provide preliminary understanding of stress, job burn-out and well-being levels among GPs to train and manage them during public health emergencies. DESIGN: We conducted a cross-sectional online self-report survey. SETTING: The survey was conducted in Chongqing, China from July to August 2022. PARTICIPANTS: Data were collected from 2145 GPs, with an effective response rate of 91.0%. PRIMARY AND SECONDARY OUTCOME MEASURES: The main evaluation indicators were stress (Cohen's Perceived Stress Scale), job burn-out (Maslach Burnout Inventory-Human Services Survey Scale) and well-being (WHO-5 Well-Being Index). Multiple linear regression analysis was used to compare the effect of different demographic characteristics on the impact of stress, job burn-out and decreased well-being. RESULTS: Stress, job burn-out and decreased well-being were common among GPs. In this study, 59.7% experienced job burn-out, 76.1% experienced high levels of stress and 52.0% may have experienced depression. The main factors that influenced stress, burn-out and well-being were differences in age, working hours per week, title, part-time management work, work-life balance, sleep disorders, whether GPs received adequate recognition by patients and the work team and mental toughness (p<0.05). CONCLUSION: This survey is the first to investigate stress, job burn-out and well-being levels among local GPs in China during the COVID-19 pandemic. Curbing stress and job burn-out levels and ensuring well-being among GPs could be achieved by reducing paperwork, management work and working hours; promoting life and work balance; and increasing resilience among GPs. The findings provide a basis for policy-makers to formulate strategies for developing general practice.


Assuntos
Esgotamento Profissional , COVID-19 , Clínicos Gerais , Humanos , Saúde Mental , Clínicos Gerais/psicologia , Estudos Transversais , Pandemias , COVID-19/epidemiologia , Esgotamento Profissional/epidemiologia , Esgotamento Profissional/psicologia , Inquéritos e Questionários , Satisfação no Emprego , China/epidemiologia
2.
PLoS One ; 18(10): e0287462, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37812597

RESUMO

General practitioners are crucial in the primary healthcare system as well as for epidemic prevention and control. However, few researchers have examined their professional identity. This study investigated the current status of the professional identity of general practitioners in Chongqing, China and explored the effects of psychological capital and patient's contempt on their professional identity. From December 2021 to January 2022, randomized cluster sampling was used to conduct a cross-sectional online self-assessment questionnaire survey among general practitioners in Chongqing. In total, 2,180 general practitioners working for more than one year were selected. General practitioners' sense of professional identity, mental health, and sense of patients' disrespect were measured using the Professional Identity Scale, Psychological Capital Questionnaire, and Patient's Contempt Questionnaire. Sociodemographic characteristics were also collected. A multiple linear regression model was used to analyze the association between professional identity, psychological capital, and patient's contempt. The average score for professional identity among general practitioners was 53.59 (SD = 6.42). The scores for self-efficacy, hope, resilience, and optimism (subscales of psychological capital) were 26.87 (SD = 5.70), 26.47 (SD = 5.74), 26.97 (SD = 5.55), and 26.86 (SD = 5.59), respectively. The score for perceived contempt was 34.19 (SD = 7.59). An average monthly income greater than CNY 8,000 (ß = 1.018, p < 0.001), work tenure of more than 15 years (ß = 0.440, p = 0.001), hope (ß = 0.249, p < 0.001) and a higher optimism score (ß = 0.333, p < 0.001) were positively correlated with professional identity. Having a bachelor's degree and above (ß = -0.720, p = 0.014), an administrative role (ß = -1.456, p < 0.001), self-efficacy (ß = -0.122, p < 0.001), and higher patient's contempt (ß = -0.103, p < 0.001) were negatively associated with professional identity. General practitioners in Chongqing demonstrated high professional identity and a strong psychological status during the COVID-19 pandemic. Psychological capital and patient's contempt were associated with professional identity. To improve general practitioners' professional identity, stakeholders should promote practitioners' mental health and physician-patient relationships in China.


Assuntos
COVID-19 , Asco , Clínicos Gerais , Humanos , Estudos Transversais , Pandemias , COVID-19/epidemiologia , China/epidemiologia , Inquéritos e Questionários
3.
Biochim Biophys Acta Mol Basis Dis ; 1868(11): 166508, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-35905940

RESUMO

Sarcopenia and obese sarcopenia are increasingly prevalent chronic diseases with multifactorial pathogenesis, and no approved therapeutic drug to date. In the established sarcopenic mice models, muscle weakness, ectopic lipid deposition, and inflammatory responses in both serum and gastrocnemius muscle were observed, which were even deteriorated in obese sarcopenic models. With metformin intervention for 5 months, metformin exhibited benefits and restoring effects on gastrocnemius muscle of sarcopenic mice, but less effective on that of obese sarcopenic mice, as reflected in the increased percentage of muscle mass and enlarged fiber cross-sectional area, enhanced grip strength and exercise capacities, as well as the ameliorated ectopic lipid deposition and partially restored level of TNF-α, IL-1ß, IL-6, MCP-1 and IL-1α, which may be via the activation of phospho-AMPKα (Thr172). The significant up-regulated mRNA and protein level of lipolysis related proteins like hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) may contribute to the ameliorated ectopic lipid deposition with metformin intervention. The uptake of free fatty acid may be also inhibited in obese sarcopenic mice with metformin administration, as reflected in down-regulated mRNA and protein level of fatty acid transporter CD36. Furthermore, NF-κB signaling pathway was involved in the anti-inflammatory effect of metformin. These findings suggest that metformin treatment may be conducive to the prevention of age-related sarcopenia by regulating lipid metabolism in skeletal muscle, i.e. enhanced lipolysis and attenuated hyper-inflammatory responses, which may be AMPK-dependent processes. Moreover, high-fat diet would aggravate the damage to ageing in skeletal muscles and reduced their reactivity to metformin.


Assuntos
Metformina , Sarcopenia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Anti-Inflamatórios , Ácidos Graxos não Esterificados/metabolismo , Interleucina-6/metabolismo , Lipase/metabolismo , Metformina/farmacologia , Metformina/uso terapêutico , Camundongos , Camundongos Obesos , Músculo Esquelético/metabolismo , NF-kappa B/metabolismo , Obesidade/complicações , Obesidade/tratamento farmacológico , Obesidade/metabolismo , RNA Mensageiro/metabolismo , Sarcopenia/tratamento farmacológico , Sarcopenia/etiologia , Esterol Esterase , Fator de Necrose Tumoral alfa/metabolismo
4.
Mitochondrial DNA B Resour ; 6(3): 826-827, 2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33763592

RESUMO

The complete chloroplast genome of Akebia longeracemosa, a monoecious woody vine endemic to China, was determined. The total genome size is 158,020 bp, containing a large single copy region of 86,659 bp, a small single copy region of 19,059 bp, and a pair of inverted repeats of 26,151 bp. The chloroplast genome encodes 113 unique genes, including 79 protein-coding genes, 30 tRNA genes and 4 rRNA genes. Among them, fifteen genes have one intron each, and three genes contain two introns. The overall GC content is 38.7%, while the corresponding values of LSC, SSC, and IR regions are 37.1, 33.6, and 43.1%, respectively. Phylogenetic analysis showed that A. longeracemosa was closely related to A. trifoliata.

5.
Medicine (Baltimore) ; 97(20): e10742, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29768348

RESUMO

BACKGROUND: Enteral nutrition via gastric tube insertion is a routine clinical practice for critically ill patients, although complications due to blind manipulation are occasionally reported. METHODS: An 8.4Fr deflection flexible ureteroscope was delivered into a 15Fr conventional gastric tube to create a gastric visual guidance system. Twenty inexperienced physicians were randomly assigned to perform 5 repeated orogastric tube placements in a manikin using both the conventional method and the deflection visual gastric tube, for a total of 10 procedures per physician. Placement time, procedure-related complications, and participants' experience with both methods were recorded. RESULTS: Under real-time guidance, the visual gastric tube successfully reached the stomach. The procedure provided additional information on the anatomy of the esophagus and stomach. Placement time was significantly less in the visual group than in the conventional group (39.39 ±â€Š2.11 seconds vs 49.82 ±â€Š3.11 seconds; P < .001). Procedure-related complications were not observed in the visual group; however, the gastric tube was misplaced into the airway in 19 out of 100 cases (19%) in the conventional group. Furthermore, 17 out of 20 participants (85%) preferred the visual gastric tube guide over the standard method. CONCLUSIONS: Results of this manikin model demonstrate that it is feasible to use the deflection flexible visual gastric tube to create a route for enteral nutrition and that such a procedure decreases placement time and procedure-related complications compared to the conventional procedure. These findings may point to a new strategy for gastric tube insertion in the future.


Assuntos
Estado Terminal/terapia , Nutrição Enteral , Intubação Gastrointestinal , Estudos Cross-Over , Nutrição Enteral/instrumentação , Nutrição Enteral/métodos , Estudos de Viabilidade , Humanos , Intubação Gastrointestinal/efeitos adversos , Intubação Gastrointestinal/instrumentação , Intubação Gastrointestinal/métodos , Manequins , Avaliação de Resultados em Cuidados de Saúde
6.
Eur J Med Res ; 22(1): 48, 2017 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-29162156

RESUMO

OBJECTIVE: This study aimed to investigate the therapeutic effects of 5-fluorouracil (5-FU)-loaded nanobubbles irradiated with low-intensity, low-frequency ultrasound in nude mice with hepatocellular carcinoma (HCC). METHODS: A transplanted tumor model of HCC in nude mice was established in 40 mice, which were then randomly divided equally into four groups: group A (saline), group B (5-FU-loaded nanobubbles), group C (5-FU-loaded nanobubbles with non-low-frequency ultrasound), and group D (5-FU-loaded nanobubbles with low-frequency ultrasound). The tumor size in each mouse was observed via ultrasound before and after the treatments. Inhibition of the tumor growth in each group was compared, and survival curves were generated. Tumor tissues were removed to determine the apoptotic index using the TUNEL method and quantitative analysis. Tumor tissues with CD34-positive microvessels were observed by immunohistochemistry, and the tumor microvessel densities were calculated. RESULTS: The growth rate of the tumor volumes in group D was significantly slower than that in the other groups, while the tumor inhibition rates and apoptotic index in group D were significantly higher than those of the other groups. The number of microvessels staining positive for CD34 was decreased in group D. Therefore, group D presented the most significant inhibitory effects. CONCLUSIONS: Therefore, 5-FU-loaded nanobubbles subjected to irradiation with low-frequency ultrasound could further improve drug targeting and effectively inhibit the growth of transplanted tumors, which is expected to become an ideal drug carrier and targeted drug delivery system for the treatment of HCC in the future.


Assuntos
Antineoplásicos/administração & dosagem , Carcinoma Hepatocelular/tratamento farmacológico , Fluoruracila/administração & dosagem , Neoplasias Hepáticas/tratamento farmacológico , Animais , Feminino , Células Hep G2 , Humanos , Masculino , Camundongos , Camundongos Nus , Microbolhas , Nanotecnologia/métodos , Ondas Ultrassônicas , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Gastroenterol Res Pract ; 2016: 7532172, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27994620

RESUMO

Background. Conventional nasogastric tube placement is an essential clinical procedure; however, complications may arise from blind manipulation. We tested the feasibility and efficiency of a visual nasogastric tube insertion system (VNGS) using a manikin. Methods. A microimaging fiber (0.8 mm) was integrated into the nasogastric tube to create the VNGS. Twenty inexperienced physicians were enrolled and assigned to the visual or conventional group. Each physician performed 10 repeated nasogastric tube insertions with visual guidance or the conventional method; another 20 inexperienced medical students received nasogastric tube insertion training using visual guidance or the conventional method. Results. The nasogastric tube successfully reached the stomach and the narrow anatomic structures were visualized with the VNGS. Time required for insertion was significantly shorter in the visual group compared to the conventional group (22.56 ± 3.08 versus 37.30 ± 4.12 seconds, P < 0.001). Tube misplacement was observed in 19/100 cases (19%) in the conventional group; no misplacement was observed in the visual group. Less mucosal damage was noted in the visual group (3.43 ± 1.63 versus 9.86 ± 2.31 cm2). Medical students performed better NGT insertions (shorter insertion time and less procedure-related complications) after undergoing the visual guidance training. Conclusions. The VNGS may provide a new technique for nasogastric tube insertion applicable to clinical use or simulation training.

9.
Am J Emerg Med ; 32(11): 1391-4, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25224024

RESUMO

BACKGROUND: Conventional needle cricothyroidotomy uses blind manipulation. We investigated the feasibility and efficiency of a new visually guided needle cricothyroidotomy technique. METHODS: A 0.9-mm microimaging fiber was delivered into a 14G needle to develop a visual puncture system. 10 inexperienced physicians were randomly assigned to perform 10 repeated needle cricothyroidotomy in each group with both conventional method and visual puncture in a manikin. Tracheal lumen puncture time and number of procedure-related complications were recorded. RESULTS: Under visual guidance, the needle successfully reached the tracheal lumen. The anatomy of the upper and lower airways was acquired by further advancing the microimaging fiber into the tracheal lumen of the visual group. The tracheal lumen puncture time was significantly less in the visual group than in the conventional group (3.85 ± 1.54 vs. 9.84 ± 1.08 seconds, P < .001). Damage to the posterior tracheal wall was not observed in the visual group; however, 21% of manikins in the conventional group had procedure-related complications. CONCLUSIONS: Our results demonstrate that visual needle cricothyroidotomy is feasible, and may lead to a decrease in procedure time and procedure-related complications compared to the conventional procedure. In addition, this strategy may also provide useful information for diagnostic purposes; therefore, visual needle cricothyroidotomy may be a new strategy for the management of difficult airways in future care.


Assuntos
Manuseio das Vias Aéreas/métodos , Cartilagem Cricoide/cirurgia , Manequins , Agulhas , Cirurgia Vídeoassistida/métodos , Competência Clínica , Estudos de Viabilidade , Humanos , Punções
10.
PLoS One ; 9(1): e84829, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24416294

RESUMO

PURPOSE: To assess the feasibility and safety of imaging canine peripheral airways (<1 mm) with an experimental micro-imaging fiber optic bronchoscope. METHODS: Twenty healthy dogs were scoped with a micro-imaging fiber optic bronchoscope (0.8 mm outer diameter). Images at various levels of the bronchioles, mucosal color, and tracheal secretions were recorded. The apparatus was stopped once it was difficult to insert. CT imaging was performed simultaneously to monitor progression. The safety of the device was evaluated by monitoring heart rate (HR), respiratory rate (RR), mean artery pressure (MAP), peripheral oxygen saturation (SpO2) and arterial blood gases (partial pressure of arterial carbon-dioxide, PaCO2, partial pressure of arterial oxygen, PaO2, and blood pH). RESULTS: (1) According to the CT scan, the micro-imaging fiber was able to access the peripheral airways (<1 mm) in canines. (2) There was no significant change in the values of HR, MAP, pH and PaCO2 during the procedure (P>0.05). Comparing pre-manipulation and post-manipulation values, SpO2 (F = 13.06, P<0.05) and PaO2 (F = 3.01, P = 0.01) were decreased, whereas RR (F = 3.85, P<0.05) was elevated during the manipulation. (3) Self-limited bleeding was observed in one dog; severe bleeding or other complications did not occur. CONCLUSION: Although the new apparatus had little effect on SpO2, PaO2 and RR, it can probe into small peripheral airways (<1 mm), which may provide a new platform for the early diagnosis of bronchiolar diseases.


Assuntos
Broncoscopia/instrumentação , Tecnologia de Fibra Óptica , Sistema Respiratório/diagnóstico por imagem , Segurança , Microtomografia por Raio-X/efeitos adversos , Microtomografia por Raio-X/instrumentação , Animais , Cães , Estudos de Viabilidade , Feminino , Masculino
11.
Int J Clin Exp Med ; 7(12): 4819-27, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25663978

RESUMO

OBJECTIVE: This study is to test the effectiveness of fiber-optic-guided endotracheal suction catheter (visual sputum suctioning system or VSSS) in dog models. METHODS: Dog sputum models were established by administering dimethoate emulsifiable. Twenty-seven intubated dogs were equally randomized into three groups of conventional suctioning (CS) group, VSSS with no supplemental oxygen (VSSS) group and VSSS with 100% oxygen (VSSS/O2) group. The suctioning efficiency, vital signs and tracheal wall injury were assessed. RESULTS: The VSSS/O2 (8.6 ± 0.7g) and VSSS groups (8.5 ± 0.9 g) collected significantly more sputum than the CS group (5.9 ± 0.8 g) (P < 0.05 for VSSS/O2 group versus CS group; P < 0.05 for VSSS group versus CS group). Immediately after suctioning, the arterial partial pressure of oxygen (PaO2 ) of VSSS/O2 group was significantly higher than that of the VSSS group or the CS group (both P < 0.05), and 5 min after suction the PaO2 , the mean arterial pressure (MAP) and heart rate (HR) in all groups returned to the baseline (p = 0.54, P = 0.67, P = 0.11, respectively). Moreover, in the VSSS/O2 and VSSS groups all the three variables were higher than the CS group at 5 min after suctioning (P < 0.01, P = 0.03; P = 0.02, P < 0.01; P = 0.02, P = 0.01 respectively). CONCLUSIONS: Visual sputum suctioning system collected more sputum and caused less tracheal mucosa damage than conventional suctioning.

12.
Respir Care ; 58(10): 1637-42, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23533294

RESUMO

BACKGROUND: Conventional sputum suctioning is a routine clinical practice, but complications may arise from the blind manipulation of the catheter. Recently, a visual sputum suctioning system (VSSS) was developed, and we tested this new system in a laboratory setting. METHODS: We used coagulant concentrations of 1.5% and 3.0% to simulate mucus and sputum. Conventional single-lumen and triple-lumen catheters were inserted separately into a beaker for sputum suctioning (15 s, 200 mm Hg). A micro-imaging fiber was integrated into the triple-lumen catheter to create the VSSS. The single-lumen catheter and the VSSS were inserted separately into the mouth cavity, the nasal cavity, the tracheostomy tube, and the endotracheal tube of a human analog model for further comparisons. RESULTS: As the suction channel of the triple-lumen catheter was reduced by 46.8%, the amount of simulant it suctioned was significantly less than that suctioned by the single-lumen catheter. However, under real-time guidance, the VSSS suctioned more simulant than the conventional single-lumen catheter in the human analog model. CONCLUSION: Sputum suctioning with the VSSS was feasible. Because of its real-time imaging guidance, the efficiency of the VSSS procedure was greater than that of the conventional single-lumen catheter. Therefore, this system may provide a new platform for sputum suctioning.


Assuntos
Catéteres , Escarro/química , Sucção/instrumentação , Desenho de Equipamento , Estudos de Viabilidade , Humanos , Intubação Intratraqueal
13.
Intern Med ; 52(4): 463-5, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23411702

RESUMO

An 87-year-old man with a diagnosis of constrictive pericarditis suffered from cough syncope up to 10 times per day on most days during his three-day stay at our hospital. After undergoing a series of treatments (diuretics, codeine and intravenous ceftizoxime), the patient still had a mild cough, although he did not experience any further syncopal episodes associated with coughing. Two months later, the syncopal episodes associated with coughing returned, but at a lower rate.


Assuntos
Tosse/etiologia , Pericardite Constritiva/complicações , Síncope/etiologia , Idoso de 80 Anos ou mais , Humanos , Masculino
14.
Zhonghua Nan Ke Xue ; 17(7): 596-600, 2011 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-21823340

RESUMO

OBJECTIVE: To analyze the relation between recurrent miscarriage and routine semen parameters. METHODS: We compared the semen parameters of normal healthy men with those of the spouses of recurrent miscarriage women through 1: 1 age-matched case-control study. RESULTS: Compared with the healthy controls, the men of the case group showed a significantly lower mean semen volume ([1.95 +/- 1.11] ml vs [2.74 +/- 1.43] ml), sperm concentration ([48.68 +/- 20.07] x 10(6)/ml vs [59.26 +/- 25.35] x 10(6)/ml), percentage of grade b sperm ([12.07 +/- 3.34] % vs [16.18 +/- 6.74] %), fruit-sugar content ([1.73 +/- 0.64] g/L vs [2.21 +/- 0.75] g/L), acrosomal enzyme activity ([84.34 +/- 26.69] U/mg prot vs [94.20 +/- 26.35] U/mg prot), alpha-glucuronidase (alpha-GLU) content ([36.28 +/- 15.98] U/ml vs [44.45 +/- 12. 54] U/ml), and acid phosphatase (ACP) content ([68.55 +/- 35.45] U/ml vs [84.78 +/- 51. 10] U/ml) (P < 0.05), but remarkably higher percentages of head teratospermia ([47.36 +/- 4.59] % vs [46.50 +/- 6.32] %) and tail teratospermia ([7.56 +/- 2.27] % vs [7.28 +/- 3.10] %), and elastase content ([885.64 +/- 1 272.30] ng/ml vs [661.08 +/- 764.64] ng/ml) (P < 0.05). Based on the results of discriminant analysis, the semen volume, percentages of grade b sperm and combined teratospermia, and contents of fruit-sugar, alpha-GLU and ACP could be used to evaluate the semen and sperm quality of the spouses of recurrent miscarriage women. CONCLUSION: Routine semen and sperm tests might help evaluate the seminal factors of recurrent miscarriage, but they lack specificity and need comprehensive analysis. Poorer semen quality is associated with higher incidence of recurrent miscarriage.


Assuntos
Aborto Habitual/etiologia , Sêmen , Espermatozoides , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Gravidez , Contagem de Espermatozoides , Motilidade dos Espermatozoides
15.
Int J Urol ; 17(2): 182-6, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20088876

RESUMO

OBJECTIVES: To investigate afferent pathway dysfunction in children with primary nocturnal enuresis by measuring pudendal somatosensory evoked potential and tibial somatosensory evoked potential. METHODS: Subjects with primary nocturnal enuresis, 36 boys and 18 girls, aged from 5 to 16 years, were enrolled in this study: 24 subjects had complicated primary enuresis (CPE) and 30 subjects had monosymptomatic primary enuresis (MPE). There were no differences in bodyweight or gender between the MPE and CPE groups (P > 0.05). All of the children underwent physical examination, urine analysis, urinary ultrasound and spinal magnetic resonance imaging. Only subjects without urological and neurological abnormalities (with the exception of spina bifida occulta, which was found in some of the patients) were included in this neurophysiological study. RESULTS: There were 20 children who were positively recorded with pudendal somatosensory evoked potential in the CPE group, and all of the children in the MPE group were positively recorded (P < 0.05). Positive records of tibial somatosensory evoked potential were successfully achieved in both groups. Furthermore, the pudendal and tibial conductive velocity were slower as compared to the normal range, especially in children in the CPE group (P < 0.001). CONCLUSIONS: Afferent pathway function may be impaired by some factors, which should be considered by both clinicians and parents.


Assuntos
Vias Aferentes/fisiopatologia , Potenciais Somatossensoriais Evocados , Enurese Noturna/fisiopatologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino
16.
J Integr Plant Biol ; 50(3): 360-7, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18713369

RESUMO

The complete process of meiosis was investigated in Pinus wallichiana, P. strobus and their artificial hybrid (F1) using microsporocytes. It is revealed that there were slightly lower chiasma frequency, lower ring bivalent frequency, lower meiotic index and distinctly higher frequency of aberrance (chromosomal bridges, fragments or micronuclei) in pollen mother cells (PMCs) of the hybrid (F1) than those of the parental species, which showed a certain degree of differentiation between homologous chromosomes of the two parents. However, relatively higher frequency of ring bivalents and higher meiotic index in all the three entities indicate the great stability of genomes of parental species, and the differentiation of genomes between the two parents must have been slight. Total nineteen signal loci of 18S rDNA were observed in nine bivalents of the hybrid (F1), among which one bivalent bears two loci, while the others have only one. It is suggested that distinct differentiation at genetic level existed in homologous chromosomes of the two parental species, whereas only slight differentiation at karyotypic and genomic levels take place between the parent species.


Assuntos
Cromossomos de Plantas/metabolismo , DNA Ribossômico/metabolismo , Hibridização Genética , Hibridização in Situ Fluorescente , Meiose , Pinus/citologia , Pólen/citologia , Anáfase , Cruzamentos Genéticos , Metáfase , Pinus/metabolismo , Pólen/metabolismo , Prófase , Telófase
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