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1.
Epidemiol Infect ; 145(5): 848-856, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28065170

RESUMO

Whole apples have not been previously implicated in outbreaks of foodborne bacterial illness. We investigated a nationwide listeriosis outbreak associated with caramel apples. We defined an outbreak-associated case as an infection with one or both of two outbreak strains of Listeria monocytogenes highly related by whole-genome multilocus sequence typing (wgMLST) from 1 October 2014 to 1 February 2015. Single-interviewer open-ended interviews identified the source. Outbreak-associated cases were compared with non-outbreak-associated cases and traceback and environmental investigations were performed. We identified 35 outbreak-associated cases in 12 states; 34 (97%) were hospitalized and seven (20%) died. Outbreak-associated ill persons were more likely to have eaten commercially produced, prepackaged caramel apples (odds ratio 326·7, 95% confidence interval 32·2-3314). Environmental samples from the grower's packing facility and distribution-chain whole apples yielded isolates highly related to outbreak isolates by wgMLST. This outbreak highlights the importance of minimizing produce contamination with L. monocytogenes. Investigators should perform single-interviewer open-ended interviews when a food is not readily identified.


Assuntos
Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Listeria monocytogenes/isolamento & purificação , Listeriose/epidemiologia , Malus/microbiologia , Doces/microbiologia , Carboidratos , Doenças Transmitidas por Alimentos/microbiologia , Genótipo , Entrevistas como Assunto , Listeria monocytogenes/classificação , Listeria monocytogenes/genética , Listeriose/microbiologia , Tipagem de Sequências Multilocus , Análise de Sobrevida , Estados Unidos/epidemiologia
2.
Epidemiol Infect ; 143(16): 3451-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25865140

RESUMO

The 2013 multistate outbreaks contributed to the largest annual number of reported US cases of cyclosporiasis since 1997. In this paper we focus on investigations in Texas. We defined an outbreak-associated case as laboratory-confirmed cyclosporiasis in a person with illness onset between 1 June and 31 August 2013, with no history of international travel in the previous 14 days. Epidemiological, environmental, and traceback investigations were conducted. Of the 631 cases reported in the multistate outbreaks, Texas reported the greatest number of cases, 270 (43%). More than 70 clusters were identified in Texas, four of which were further investigated. One restaurant-associated cluster of 25 case-patients was selected for a case-control study. Consumption of cilantro was most strongly associated with illness on meal date-matched analysis (matched odds ratio 19·8, 95% confidence interval 4·0-∞). All case-patients in the other three clusters investigated also ate cilantro. Traceback investigations converged on three suppliers in Puebla, Mexico. Cilantro was the vehicle of infection in the four clusters investigated; the temporal association of these clusters with the large overall increase in cyclosporiasis cases in Texas suggests cilantro was the vehicle of infection for many other cases. However, the paucity of epidemiological and traceback information does not allow for a conclusive determination; moreover, molecular epidemiological tools for cyclosporiasis that could provide more definitive linkage between case clusters are needed.


Assuntos
Coriandrum/parasitologia , Cyclospora/isolamento & purificação , Ciclosporíase/epidemiologia , Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Criança , Pré-Escolar , Análise por Conglomerados , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Texas/epidemiologia , Adulto Jovem
3.
Cancer Invest ; 29(1): 68-72, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20873993

RESUMO

Laboratory data suggest an association between statins and risk of brain metastasis (BM) in patients diagnosed with lung cancer. Our retrospective cohort included 252 patients diagnosed with lung cancer and 55 (22%) patients subsequently developed BM. The risk of BM was significantly higher in younger patients (p < .0007). The multivariable Cox model did not show a significant association between statin use and BM from lung cancer (Hazard-Ratio (HR) = 1.20, 95% confidence interval (CI): 0.68-2.13). Future studies should focus on late stage NSCLC and examine the incidence of BM among statin users at the time of death.


Assuntos
Neoplasias Encefálicas/secundário , Carcinoma Pulmonar de Células não Pequenas/secundário , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Neoplasias Pulmonares/patologia , Carcinoma de Pequenas Células do Pulmão/secundário , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Distribuição de Qui-Quadrado , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Masculino , Pessoa de Meia-Idade , North Dakota , Prognóstico , Modelos de Riscos Proporcionais , Sistema de Registros , Estudos Retrospectivos , Medição de Risco , Fatores de Risco
4.
Gynecol Obstet Fertil Senol ; 48(2): 174-180, 2020 02.
Artigo em Francês | MEDLINE | ID: mdl-31634590

RESUMO

OBJECTIVES: Increased nuchal translucency and cystic hygroma have a neonatal prognosis, when the karyotype is normal, which depends on the findings during the medical follow-up. Array comparative genomic hybridization (aCGH) has been systematically included in this follow-up by prenatal diagnosis teams. There are no guidelines and little information on the advantages of carrying out this test systematically. The aim of our study is to evaluate the contribution of the aCGH in the medical follow-up. METHODS: Fifty-one patients were included during 18 months and followed till the end of their pregnancy in prenatal diagnosis centers in Brest and Amiens. Inclusion criterion was a nuchal translucency above 3,5mm on the first trimester ultrasound. A fetal DNA ChromoQuant and aCGH analysis on chorionic villi sampling, and an ultrasound at 18 weeks of gestation were performed during the follow-up. RESULTS: The aCGH was decisive in only 2 cases. The ultrasound at 18 weeks gestation seemed to be more sensible in the detection of an abnormality. When the aCGH relieved an abnormality, the ultrasound permitted already to detect the presence of a deformity. In 10 cases, the aCGH could not be interpreted on the chorionic villi sampling. In 9 cases, an amniocentesis was performed in order to obtain this result. CONCLUSION: Given the results of this study, the aCGH was rarely determinant or decisive on the realization of a therapeutic abortion. These elements make us reflect on the necessity of maintaining this test before 14 weeks of gestation or propose it as a second-line test after the ultrasound shows signs at 18weeks of gestation.


Assuntos
Hibridização Genômica Comparativa/métodos , Medição da Translucência Nucal , Diagnóstico Pré-Natal/métodos , Aborto Terapêutico , Amniocentese , Amostra da Vilosidade Coriônica , Feminino , Testes Genéticos , Idade Gestacional , Humanos , Recém-Nascido , Cariótipo , Análise de Sequência com Séries de Oligonucleotídeos , Gravidez , Primeiro Trimestre da Gravidez , Prognóstico , Ultrassonografia Pré-Natal
5.
J Vet Intern Med ; 23(6): 1315-8, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19709355

RESUMO

BACKGROUND: The range of American canine hepatozoonosis (ACH) is expanding from the southern USA northward. Transmission of Hepatozoon americanum occurs by ingestion of infected Gulf Coast ticks, Amblyomma maculatum. The source of the protozoan for the tick remains undetermined; infected dogs are unusual hosts for the tick. OBJECTIVE: Compare possible sources of infection by field investigations of 2 multiple-dog outbreaks of ACH. ANIMALS: Twenty-eight privately owned dogs (Canis familiaris), 1 coyote (Canis latrans), 31 wild-trapped cotton rats (Sigmodon hispidus), 24 wild-trapped field mice (Peromyscus leucopus), and 9 wild-caught rabbits (Sylvilagus spp.) from sites in eastern Oklahoma were monitored for hepatozoonosis. Six laboratory-raised cotton rats (S. hispidus), 6 Sprague-Dawley rats (Rattus norvegicus), 6 C57BL/6J-Lystbg-J/J mice (Mus musculus), 6 outbred white mice (M. musculus), 6 New Zealand white rabbits (Oryctolagus cuniculus), and 2 dogs were acquired through commercial vendors for experimental transmission trials of H. americanum. METHODS: Four of 15 dogs in a rural neighborhood and 5/12 hunting Beagles were confirmed to be infected by blood smear examination, muscle biopsy, and polymerase chain reaction assay of the 18S rRNA gene of Hepatozoon species. Histories and tick host preferences led to field collections of common prey of canids and experimental transmission trials of H. americanum to selected prey (M. musculus, S. hispidus, R. norvegicus, and O. cuniculus). RESULTS: Dogs with ready access to prey (4/15 dogs) or that were fed prey retrieved from hunts (5/12 hunting Beagles) became infected, providing evidence that predation is an important epidemiologic component of ACH infection. Experimental transmission studies identified a quiescent, infectious stage (cystozoite) of the parasite that provides an alternate mode of transmission to canids through predation, demonstrating that cotton rats, mice, and rabbits but not brown rats may act as paratenic hosts of H. americanum. CONCLUSIONS AND CLINICAL IMPORTANCE: Predation of prey harboring infected A. maculatum or containing cystozoites of H. americanum in their tissues provide 2 modes of transmission of ACH to dogs, putting unconfined dogs at increased risk of infection in endemic areas.


Assuntos
Coccidiose/veterinária , Surtos de Doenças/veterinária , Doenças do Cão/parasitologia , Animais , Coccídios , Coccidiose/epidemiologia , Coccidiose/transmissão , Doenças do Cão/epidemiologia , Doenças do Cão/transmissão , Cães , Camundongos , Comportamento Predatório , Coelhos , Doenças Transmitidas por Carrapatos/veterinária , Estados Unidos
6.
Trop Anim Health Prod ; 41(7): 1393-407, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19283504

RESUMO

The search for alternatives to in-feed antibiotics in animal nutrition has highlighted the role dietary modulation can play in improving gut health. Current antibiotic replacement strategies have involved the use of microbes beneficial to health (probiotics) or fermentable carbohydrates (prebiotics) or both (synbiotics). The present review recognises the contribution of fermented feeds and fermentable carbohydrates in improving the gut environment in non-ruminants. It proposes the screening of probiotic bacteria for the production of fermented feeds and supplementation of these feeds with fermentable carbohydrates prior to feeding animals. It is suggested that the term 'fermbiotics' should be used to describe this intervention strategy.


Assuntos
Ração Animal , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Metabolismo dos Carboidratos , Fermentação , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/microbiologia , Animais , Galinhas , Humanos , Sus scrofa
7.
J Reprod Med ; 53(3): 166-70, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18441719

RESUMO

OBJECTIVE: To search for a possible correlation between incidence of postpartum depression (PPD) and any of the following factors recorded in patient charts at the routine, 4-week postnatal visit: age, breast-feeding status, smoker/nonsmoker, marital status, preexisting depression and type of delivery. STUDY DESIGN: Data were obtained from 588 obstetric charts for women who gave birth between June 1, 2003, and June 1, 2004, at 3 university clinics in Tulsa, Oklahoma. RESULTS: Prior history of depression and smoking cigarettes were significant risk factors for an Edinburgh Postnatal Depression Scale score of 13 or higher, indicating probable PPD. CONCLUSION: Our data and previous findings warrant continued investigation in a larger study to clearly delineate these and other possible risk factors for PPD and to facilitate prophylactic patient education and intervention strategies.


Assuntos
Depressão Pós-Parto/psicologia , Complicações na Gravidez/psicologia , Fumar/efeitos adversos , Adulto , Fatores Etários , Aleitamento Materno , Depressão , Depressão Pós-Parto/epidemiologia , Depressão Pós-Parto/etiologia , Feminino , Humanos , Programas de Rastreamento , Gravidez , Complicações na Gravidez/epidemiologia , Complicações na Gravidez/etiologia , Escalas de Graduação Psiquiátrica , Estudos Retrospectivos , Fatores de Risco , Fumar/epidemiologia
8.
Nucleic Acids Res ; 33(Database issue): D471-5, 2005 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-15608240

RESUMO

The Mouse Genome Database (MGD) forms the core of the Mouse Genome Informatics (MGI) system (http://www.informatics.jax.org), a model organism database resource for the laboratory mouse. MGD provides essential integration of experimental knowledge for the mouse system with information annotated from both literature and online sources. MGD curates and presents consensus and experimental data representations of genotype (sequence) through phenotype information, including highly detailed reports about genes and gene products. Primary foci of integration are through representations of relationships among genes, sequences and phenotypes. MGD collaborates with other bioinformatics groups to curate a definitive set of information about the laboratory mouse and to build and implement the data and semantic standards that are essential for comparative genome analysis. Recent improvements in MGD discussed here include the enhancement of phenotype resources, the re-development of the International Mouse Strain Resource, IMSR, the update of mammalian orthology datasets and the electronic publication of classic books in mouse genetics.


Assuntos
Bases de Dados Genéticas , Genômica , Camundongos/genética , Animais , Genes , Genoma , Genótipo , Internet , Camundongos Mutantes , Fenótipo , Integração de Sistemas , Interface Usuário-Computador
9.
Pharmacotherapy ; 26(5): 689-93, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16715609

RESUMO

Amniotic fluid embolus, also known as anaphylactoid syndrome of pregnancy is a rare complication of pregnancy. When it occurs, the maternal mortality rate may be as high as 86%, and in survivors, the morbidity rate may be just as high. Hallmark clinical features include maternal cardiovascular collapse with disseminated intravascular coagulation, and fetal distress. Management centers on strategies to improve oxygenation, support circulation, and correct the coagulopathy. We report the case of a patient who developed amniotic fluid embolus and was effectively managed with aprotinin to control the coagulopathy associated with this devastating complication of pregnancy.


Assuntos
Aprotinina/uso terapêutico , Transtornos da Coagulação Sanguínea/tratamento farmacológico , Transtornos da Coagulação Sanguínea/etiologia , Embolia Amniótica/fisiopatologia , Hemostáticos/uso terapêutico , Adulto , Contagem de Células Sanguíneas , Testes de Coagulação Sanguínea , Soluções Cristaloides , Feminino , Humanos , Soluções Isotônicas/uso terapêutico , Substitutos do Plasma/uso terapêutico , Gravidez , Útero/fisiopatologia
10.
Nucleic Acids Res ; 32(Database issue): D476-81, 2004 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-14681461

RESUMO

The Mouse Genome Database (MGD) is one component of the Mouse Genome Informatics (MGI) system (http://www.informatics.jax.org), a community database resource for the laboratory mouse. MGD strives to provide a comprehensive knowledgebase about the mouse with experiments and data annotated from both literature and online sources. MGD curates and presents consensus and experimental data representations of genetic, genotype (sequence) and phenotype information including highly detailed reports about genes and gene products. Primary foci of integration are through representations of relationships between genes, sequences and phenotypes. MGD collaborates with other bioinformatics groups to curate a definitive set of information about the laboratory mouse and to build and implement the data and semantic standards that are essential for comparative genome analysis. Recent developments in MGD discussed here include an extensive integration of the mouse sequence data and substantial revisions in the presentation, query and visualization of sequence data.


Assuntos
Biologia Computacional , Bases de Dados Genéticas , Genoma , Camundongos/genética , Animais , Genômica , Armazenamento e Recuperação da Informação , Internet , Biologia Molecular , Fenótipo , Terminologia como Assunto
11.
J Am Osteopath Assoc ; 106(4): 193-8, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16627773

RESUMO

OBJECTIVE: To describe possible correlations between incidence of postpartum depression and the following patient characteristics: age, breastfeeding status, tobacco use, marital status, history of depression, and method of delivery. STUDY DESIGN: Data gathered at routine 4-week postnatal visits were obtained from the patient records of 209 women who gave birth between June 1, 2001, and June 1, 2003, at three university medical clinics in Tulsa, Okla. Inclusion criteria required that the records of potential study subjects contain data on the characteristics noted as well as patient-completed Edinburgh Postnatal Depression Scale forms. RESULTS: Formula feeding in place of breastfeeding, a history of depression, and cigarette smoking were all significant risk factors for an Edinburgh Postnatal Depression Scale score of 13 or higher, indicating probable postpartum depression. CONCLUSION: The authors' findings corroborate the results of previous investigators. To facilitate prophylactic patient education and intervention strategies, a larger study is recommended to determine risk factors for postpartum depression.


Assuntos
Depressão Pós-Parto/etiologia , Adulto , Aleitamento Materno , Feminino , Humanos , Lactente , Fórmulas Infantis , Oklahoma , Estudos Retrospectivos , Fatores de Risco , Fumar/efeitos adversos
13.
J Food Prot ; 79(5): 806-9, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27296429

RESUMO

We report on a case of listeriosis in a patient who probably consumed a prepackaged romaine lettuce-containing product recalled for Listeria monocytogenes contamination. Although definitive epidemiological information demonstrating exposure to the specific recalled product was lacking, the patient reported consumption of a prepackaged romaine lettuce-containing product of either the recalled brand or a different brand. A multinational investigation found that patient and food isolates from the recalled product were indistinguishable by pulsed-field gel electrophoresis and were highly related by whole genome sequencing, differing by four alleles by whole genome multilocus sequence typing and by five high-quality single nucleotide polymorphisms, suggesting a common source. To our knowledge, this is the first time prepackaged lettuce has been identified as a likely source for listeriosis. This investigation highlights the power of whole genome sequencing, as well as the continued need for timely and thorough epidemiological exposure data to identify sources of foodborne infections.


Assuntos
Doenças Transmitidas por Alimentos , Lactuca , Eletroforese em Gel de Campo Pulsado , Microbiologia de Alimentos , Humanos , Listeria monocytogenes/genética , Listeriose
14.
Br Dent J ; 220(7): 335-40, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27056513

RESUMO

The Cochrane Review on water fluoridation for the prevention of dental caries was published in 2015 and attracted considerable interest and comment, especially in countries with extensive water fluoridation programmes. The Review had two objectives: (i) to evaluate the effects of water fluoridation (artificial or natural) on the prevention of dental caries, and (ii) to evaluate the effects of water fluoridation (artificial or natural) on dental fluorosis. The authors concluded, inter alia, that there was very little contemporary evidence, meeting the Review's inclusion criteria, that evaluated the effectiveness of water fluoridation for the prevention of dental caries. The purpose of this critique is to examine the conduct of the above Review, and to put it into context in the wider body of evidence regarding the effectiveness of water fluoridation. While the overall conclusion that water fluoridation is effective in caries prevention agrees with previous reviews, many important public health questions could not be answered by the Review because of the restrictive criteria used to judge adequacy of study design and risk of bias. The potential benefits of using wider criteria in order to achieve a fuller understanding of the effectiveness of water fluoridation are discussed.


Assuntos
Cárie Dentária/prevenção & controle , Fluoretação , Fluorose Dentária/etiologia , Humanos , Avaliação de Programas e Projetos de Saúde , Garantia da Qualidade dos Cuidados de Saúde
15.
J Hosp Infect ; 60(4): 329-32, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15939506

RESUMO

The objective of this retrospective study was to compare the prevalence of community-associated methicillin-resistant Staphylococcus aureus (CAMRSA) and healthcare-associated MRSA (HAMRSA) using healthcare risk factor exposure criteria with that obtained using Centers for Disease Control and Prevention (CDC) criteria. Cases were defined as CAMRSA or HAMRSA based on the general CDC guidelines for nosocomial infections, and then re-assessed with healthcare risk factor exposure criteria using a medical chart review. One hundred MRSA cases occurred at a mid-Western veterans affairs medical centre from November 2001 to November 2003. The proportion of these cases classified as CAMRSA differed dramatically when classified by healthcare risk factor exposure criteria (5%) compared with CDC nosocomial infection criteria (49%). Estimating the role of healthcare-related exposures and developing strategies to control MRSA can be markedly affected by the criteria used to determine CAMRSA and HAMRSA.


Assuntos
Infecções Comunitárias Adquiridas/epidemiologia , Infecção Hospitalar/epidemiologia , Resistência a Meticilina , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/efeitos dos fármacos , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/microbiologia , Hospitais de Veteranos/estatística & dados numéricos , Humanos , Prevalência , Estudos Retrospectivos , Infecções Estafilocócicas/microbiologia , Estados Unidos/epidemiologia
16.
J Affect Disord ; 86(2-3): 295-7, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15935250

RESUMO

BACKGROUND: The purpose of this study was to search for correlations of scores on the visual analog scales (VAS) taken during the third week postpartum with scores on the Edinburgh Postnatal Depression Scale (EPDS) taken on approximately day 28 postpartum. METHODS: Thirty-four women filled out six visual analog scales on postpartum days 15-21 and took the EPDS at their 4-week postpartum visit to the clinic. Results were analyzed by simple linear regression and multiple backward stepwise regression. RESULTS: Responses to all six statements of the VAS correlated significantly with 4-week EPDS scores. Approximately 54% of the variability of 4-week EPDS scores can be predicted by the variability in VAS question 6. LIMITATIONS: Relatively small sample size is a moderately limiting factor of this study. CONCLUSION: Mood in the third week postpartum was predictive of EPDS score on postpartum day 28. Mood lability during the third week postpartum was a better predictor of EPDS score on day 28 than the other five measures, including feelings of sadness or anxiety. The EPDS may have potential use with an acceptable degree of accuracy earlier than the standard 4 weeks postpartum.


Assuntos
Depressão Pós-Parto/diagnóstico , Inventário de Personalidade/estatística & dados numéricos , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Adulto , Depressão Pós-Parto/psicologia , Feminino , Humanos , Modelos Lineares , Programas de Rastreamento/métodos , Programas de Rastreamento/estatística & dados numéricos , Período Pós-Parto/psicologia , Psicometria , Fatores de Risco , Inquéritos e Questionários , Fatores de Tempo
17.
J Comp Neurol ; 202(2): 255-63, 1981 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-6271851

RESUMO

Using Golgi preparations from adult cat and monkey the present study describes the general arborization pattern of primary afferent collaterals to the marginal layer (lamina I) of the dorsal horn. The dorsal root origin of the golgi-impregnated afferents was verified in the cat by matching the structural properties of these fibers with horseradish peroxidase (HRP)-stained primary afferents which were filled with HRP via anterograde transport through dorsal rootlets. The marginal afferents, in both the cat and the monkey, are relatively fine-caliber fibers which emanate from the dorsolateral fasciculus of Lissauer. Superficially they form a transverse plexus of fibers which runs across the surface of the dorsal horn and is especially dense in the lateral portion of the dorsal aspect of the marginal layer where lamina I is thickest. In deeper regions of the marginal layer, marginal afferents are longitudinally oriented and have collaterals within the outer zone of lamina II. In both superficial and deep regions of the marginal layer the afferents run parallel with large numbers of marginal cell dendrites. Most marginal afferents give rise to collaterals with widely spaced, round to oval "boutons en passant" and "boutons terminaux" which are 1.5-2.0 micrometers in diameter. Structural correlation with previous physiological and anatomical studies suggest that most of these fibers are finely myelinated, A-delta, high-threshold mechanoreceptive fibers.


Assuntos
Gatos/anatomia & histologia , Região Lombossacral , Macaca mulatta/anatomia & histologia , Macaca/anatomia & histologia , Neurônios Aferentes/citologia , Medula Espinal/citologia , Animais , Dendritos/ultraestrutura , Complexo de Golgi/ultraestrutura , Peroxidase do Rábano Silvestre , Neurônios Aferentes/fisiologia , Transmissão Sináptica
18.
J Comp Neurol ; 388(4): 550-64, 1997 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-9388015

RESUMO

The total neuron population of the superficial dorsal horn (SDH), i.e., laminae I and II, was quantitated in Nissl preparations of spinal segment L1 in the rat. Subpopulations of the SDH, defined by axon projection, were quantitated following strategic intraspinal injections of dual retrograde tracers (Fluoro-Gold and true blue). These methods were used in conjunction with [3H]thymidine (delivered in utero) autoradiography for neurogenic pattern analysis. Following stereological correction, each dorsal horn in spinal segment L1 contained 11 neurons in lamina I and 42.6 neurons in lamina II per 10-microm transverse section. Neurons with long projections, i.e., neurons with projections rostral to spinal segment T5, were only slightly more numerous in lamina I than in lamina II. These neurons made up 34% of the total neuron population in lamina I and 7.0% in lamina II. Most of these neurons did not demonstrate descending connections, and many (presumed supraspinal projection neurons) did not demonstrate short, ascending, intersegmental connections. Neurons with short propriospinal projections, i.e., neurons with connections caudal to spinal segment T5, made up approximately half of the total neuron population in both lamina I and lamina II: 55% and 52%, respectively. Of these, 79% had both short ascending and descending projections; the remaining 21% had only descending projections. Neurons that were not labeled with retrograde tracers (presumed local circuit cells) represented 11% of the neurons in lamina I and 41% in lamina II. Neurogenesis in the SDH proceeded along an axon-length gradient, whereby neurons with the longest axons completed neurogenesis first, and those with the shortest completed neurogenesis last. The generation of both propriospinal and supraspinal projection neurons began on embryonic day 13 (E13). Nearly equal numbers of neurons in this group were generated in laminae I and II through E14. On E15, neuron production slowed in lamina I and accelerated in lamina II as local circuit neurons and the remaining propriospinal neurons were generated. Neuron production ceased simultaneously in both lamina I and lamina II on E16.


Assuntos
Axônios/fisiologia , Neurônios/fisiologia , Medula Espinal/fisiologia , Animais , Autorradiografia , Contagem de Células , Desenvolvimento Embrionário e Fetal , Feminino , Região Lombossacral , Masculino , Neurônios/ultraestrutura , Ratos , Ratos Wistar , Medula Espinal/citologia , Medula Espinal/embriologia
19.
J Comp Neurol ; 388(4): 565-74, 1997 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-9388016

RESUMO

Dual retrograde axonal tracers, Fluoro-Gold (FG) and true blue (TB), were used in conjunction with [3H]thymidine autoradiography to determine the number and neurogenic pattern of neurons with supraspinal projections in the superficial dorsal horn (SDH), i.e., laminae I and II, in spinal segment L1 of the rat. FG was injected into rostral brain centers (dorsal thalamus and midbrain), and TB was injected into the caudal brainstem (medulla) in young adult rats previously administered [3H]thymidine in utero. Following stereological correction, each dorsal horn had an average of 1.22 neurons in lamina I and 0.24 neurons in lamina II that had supraspinal projections per 10-microm transverse section. In the SDH, 52% of the neurons with supraspinal projections were found to project to rostral brain centers alone, 3.0% only to the caudal brainstem, and 45% to both areas. There was no significant difference in the percentage distribution of each of the three groups of neurons between lamina I and lamina II. Cell counts in the present study, in conjunction with previous observations in the literature, suggest that the majority of supraspinal projection neurons in the SDH fall into two groups: 1) spinomesencephalic neurons with collaterals to the medulla and 2) spinothalamic neurons with collaterals to the midbrain. The neurogenesis of supraspinal projection neurons in the SDH proceeded along an axon-length gradient, whereby neurons with the longest axons, those with projections to rostral brain centers, completed neurogenesis prior to neurons with shorter axons, those with projections only to the caudal brainstem. The generation of all SDH neurons with supraspinal projections was completed on embryonic day 14 (E14), 2 days prior to the completion of neurogenesis for SDH neurons with intraspinal projections.


Assuntos
Mapeamento Encefálico , Bulbo/fisiologia , Mesencéfalo/fisiologia , Neurônios/fisiologia , Medula Espinal/fisiologia , Tálamo/fisiologia , Animais , Autorradiografia , Contagem de Células , Desenvolvimento Embrionário e Fetal/fisiologia , Região Lombossacral , Vias Neurais/fisiologia , Ratos , Medula Espinal/citologia , Medula Espinal/embriologia
20.
J Comp Neurol ; 180(1): 17-41, 1978 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-418084

RESUMO

Two types of neurons, projection and intrinsic, previously identified in Golgi preparations of the adult monkey (Macaca mulatta) basilar pontine gray (Cooper and Fox, '76) were observed electronmicroscopically in Macaca mulatta and the squirrel monkey Saimiri sciureus. The cell body of the projection neuron measures up to 37 micrometer and its cytoplasm is rich in organelles. The Goli apparatus, ribosomes, and mitochondria are disposed around the nucleus, while rough endoplasmic reticulum though abundant is usually confined to one half of the cell body. The cell body of the intrinsic neuron measures less than 20 micrometer and its cytoplasm displays prominent ribosomes, but a paucity of other organelles. Five types of synaptic profiles have been identified in the neuropil of the basilar pons; one measures up to 5 micrometer and the rest 2 micrometer or less. They are: (1) a large profile (MSV) containing medium size vesicles (500A) and a central core of mitochondria and neurofilaments; (2) a profile (SSV) containing small round vesicles (250-500 A) which is the most abundant and ubiquitous; (3) a profile (F) containing flattened or pleomorphic vesicles; (4) a profile (LSV) containing large oval egg shaped vesicles (750 A); and (5) a pale profile (PP) that contains oval and occasionally pleomorphic vesicles. MSV, SSV, and LSV terminals form asymmetrical contacts and F terminals form symmetrical contacts with both dendritic and vesicle-containing, pale profiles. The vesicle-containing, pale profile is both pre- and post-synaptic and participates in serial synapses. Following unilateral cortical ablations both dark and filamentous degeneration were observed in the ipsilateral basilar pontine gray.


Assuntos
Neurônios/ultraestrutura , Ponte/ultraestrutura , Sinapses/ultraestrutura , Animais , Complexo de Golgi/ultraestrutura , Haplorrinos , Macaca mulatta , Degeneração Neural , Saimiri , Vesículas Sinápticas/ultraestrutura
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