RESUMO
STUDY QUESTION: Does the prewash total motile sperm count (TMSC) have a better predictive value for spontaneous ongoing pregnancy (SOP) than the World Health Organization (WHO) classification system? SUMMARY ANSWER: The prewash TMSC shows a better correlation with the spontaneous ongoing pregnancy rate (SOPR) than the WHO 2010 classification system. WHAT IS KNOWN ALREADY: According to the WHO classification system, an abnormal semen analysis can be diagnosed as oligozoospermia, astenozoospermia, teratozoospermia or combinations of these and azoospermia. This classification is based on the fifth percentile cut-off values of a cohort of 1953 men with proven fertility. Although this classification suggests accuracy, the relevance for the prognosis of an infertile couple and the choice of treatment is questionable. The TMSC is obtained by multiplying the sample volume by the density and the percentage of A and B motility spermatozoa. STUDY DESIGN, SIZE, DURATION: We analyzed data from a longitudinal cohort study among unselected infertile couples who were referred to three Dutch hospitals between January 2002 and December 2006. Of the total cohort of 2476 infertile couples, only the couples with either male infertility as a single diagnosis or unexplained infertility were included (n = 1177) with a follow-up period of 3 years. PARTICIPANTS/MATERIALS, SETTING, METHODS: In all couples a semen analysis was performed. Based on the best semen analysis if more tests were performed, couples were grouped according to the WHO classification system and the TMSC range, as described in the Dutch national guidelines for male infertility. The primary outcome measure was the SOPR, which occurred before, during or after treatments, including expectant management, intrauterine insemination, in vitro fertilization or intracytoplasmic sperm injection. After adjustment for the confounding factors (female and male age, duration and type of infertility and result of the postcoital test) the odd ratios (ORs) for risk of SOP for each WHO and TMSC group were calculated. The couples with unexplained infertility were used as reference. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 514 couples did and 663 couples did not achieve a SOP. All WHO groups have a lower SOPR compared with the unexplained group (ORs varying from 0.136 to 0.397). Comparing the couples within the abnormal WHO groups, there are no significant differences in SOPR, except when oligoasthenoteratozoospermia is compared with asthenozoospermia [OR 0.501 (95% CI 0.311-0.809)] and teratozoospermia [OR 0.499 (95% CI: 0.252-0.988)], and oligoasthenozoospermia is compared with asthenozoospermia [OR 0.572 (95% CI: 0.373-0.877)]. All TMSC groups have a significantly lower SOPR compared with the unexplained group (ORs varying from 0.171 to 0.461). Couples with a TMSC of <1 × 10(6) and 1-5 × 10(6) have significantly lower SOPR compared with couples with a TMSC of 5-10 × 10(6) [respectively, OR 0.371 (95% CI: 0.215-0.64) and OR 0.505 (95% CI: 0.307-0.832)]. LIMITATIONS, REASON FOR CAUTION: To include all SOPs during the follow-up period of 3 years, couples were not censured at the start of treatment. WIDER IMPLICATIONS OF THE FINDINGS: Roughly, three prognostic groups can be discerned: couples with a TMSC <5, couples with a TMSC between 5 and 20 and couples with a TMSC of more than 20 × 10(6) spermatozoa. We suggest using TMSC as the method of choice to express severity of male infertility. STUDY FUNDING/COMPETING INTERESTS: None.
Assuntos
Infertilidade Masculina/classificação , Infertilidade Masculina/diagnóstico , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Adulto , Feminino , Humanos , Estudos Longitudinais , Masculino , Prognóstico , Reprodutibilidade dos Testes , Análise do Sêmen , Índice de Gravidade de Doença , Espermatozoides , Organização Mundial da SaúdeRESUMO
The decline of physical activity is considered to play an important role in the deterioration of health predictors, such as overweight, and the associated increase of cardiovascular and all-cause mortality. Therefore, most interventional strategies aim for increasing physical activity. Instead of physical activity, some studies use physical fitness as a key variable. Though physical fitness is influenced by genetic factors, physical fitness has to be developed by physical activity. As recent reports demonstrate the prospective associations between physical fitness and health and mortality, these associations are not reported for physical activity. Due to the fact that physical fitness-in contrast to physical activity-is evaluated with standardized laboratory measurements, it appears advisable to assess physical fitness for prospective health perspectives. Although physical fitness is determined by genetics, physical activity is the primary modifiable determinant for increasing physical fitness and should be aimed for to improve physical fitness in interventional strategies.
Assuntos
Nível de Saúde , Modelos Biológicos , Atividade Motora/fisiologia , Esforço Físico/fisiologia , Aptidão Física/fisiologia , HumanosRESUMO
BACKGROUND: Unexplained infertility is one of the most common diagnoses in fertility care. The aim of this study was to evaluate the outcome of current fertility management in unexplained infertility. METHODS: In an observational, longitudinal, multicentre cohort study, 437 couples were diagnosed with unexplained infertility and were available for analysis. They were treated according to their prognosis using standing national treatment protocols: (i) expectant management-IUI-IVF (main treatment route), (ii) IUI-IVF and (iii) directly IVF. Primary outcome measures were: ongoing pregnancy rate, patient flow over the strategies, numbers of protocol violation and drop out rates. A secondary outcome measure was the prediction of ongoing pregnancy and mode of conception. RESULTS: Of all couples 81.5% (356/437) achieved an ongoing pregnancy and 73.9% (263/356) of the pregnancies were conceived spontaneously. There were 408 couples (93.4%) in strategy-1, 21 (5.0%) in strategy-2 and 8 (1.8%) in strategy-3. In total, 33 (7.6%) couples entered the wrong strategy. There were 104 couples (23.8%) who discontinued fertility treatment prematurely: 26 on doctor's advice (with 4 still becoming pregnant) and 78 on their own initiative (with 33 still achieving a pregnancy). Predictors for overall pregnancy chance and mode of conception were duration of infertility, female age and obstetrical history. CONCLUSIONS: Overall success rate in couples with unexplained infertility is high. Most pregnancies are conceived spontaneously. We recommend that if the pregnancy prognosis is good, expectant management should be suggested. The prognosis criteria for treatment with IUI or IVF needs to be investigated in randomized controlled trials.
Assuntos
Infertilidade/terapia , Taxa de Gravidez , Adulto , Feminino , Fertilização in vitro , Humanos , Estudos Longitudinais , Masculino , Países Baixos , Gravidez , PrognósticoRESUMO
In this longitudinal multicentre cohort study, the overall ongoing pregnancy rate after current evidence-based management in male subfertility was studied. All subfertile couples who visited the fertility clinic for the first time between 2002 and 2006, and had male subfertility as a single diagnosis (n = 762 of 2476 couples), were included in this study. Couples were grouped by the severity of male factor. Group I (n = 541) had a total motile sperm count (TMSC) 1-20 × 10(6). Group II (n = 161) had a TMSC <1 × 10(6). Group III (n = 60) had azoospermia. The overall ongoing pregnancy rate was 65.5% (500/762). The overall ongoing pregnancy rates in group I (69.3%) and group II (61.5%) were comparable (p = 0.06). However, group I and group II conceived significantly more frequently than group III (43.3%) (group I vs. group III p < 0.001 and group II vs. group III p = 0.02, respectively). Moreover, the spontaneous ongoing pregnancy rate in group I was 35.3%, in group II 22.4% and in group III, 1.7% (group I vs. group II p = 0.002; group I vs. group III p < 0.001; group II vs. group III p < 0.001). Thus, despite a significant difference in spontaneous ongoing pregnancy rates, except for azoospermia, the overall ongoing pregnancy rates, regardless of the severity of the male factor, were comparable. Couples with poorer sperm parameters, however, have to undergo more invasive treatment to reach the same goal.
Assuntos
Infertilidade Masculina/patologia , Feminino , Humanos , Masculino , Gravidez , Taxa de Gravidez , Índice de Gravidade de DoençaRESUMO
This longitudinal multicentre cohort study aimed to identify the role of the conception mode in infertile couples with an early pregnancy loss (EPL). All couples referred to the fertility clinic for the first time in the period 2002-2006 because of infertility were followed up to their first clinical pregnancy (n=1809). EPL was the outcome of 286 (15.8%) pregnancies. EPL rates for the different conception modes were as follows: spontaneous 14.5% (125/864), ovulation induction 15.8% (42/266), intrauterine insemination 25.0% (5/20), intrauterine insemination combined with ovarian stimulation 18.2% (37/203), IVF 16.3% (31/190), intracytoplasmic sperm injection (ICSI) 14.9% (30/202) and frozen embryo transfer (FET) 26.2% (16/61). After adjusting for female age, male age, hospital, obstetric history, female smoking habit, male alcohol use, menstrual cycle type and infertility diagnosis, the EPL rate after FET was significantly increased (odds ratio 2.2, 95% CI 1.14-4.19) compared with spontaneous conception. Embryo quality was comparable in fresh and frozen embryos. Other fertility treatments showed no increased miscarriage rate. Therefore, it is concluded that even after adjustment for confounding factors conception through FET remained an independent risk factor for EPL. Other modes of conception were not related with EPL.
Assuntos
Aborto Espontâneo/epidemiologia , Técnicas de Reprodução Assistida/efeitos adversos , Aborto Espontâneo/etiologia , Adulto , Feminino , Humanos , Estudos Longitudinais , Masculino , Países Baixos , Gravidez , Fatores de RiscoRESUMO
BACKGROUND: Although in vitro fertilization (IVF) was introduced more than 30 years ago, its exact role in the spectrum of fertility treatments has never been studied in an unselected population. The aim of this study was to visualize the contribution of IVF to the ongoing pregnancy rates in a cohort of newly referred subfertile couples. MATERIALS: All new subfertile couples (n = 1391) that were referred to our fertility clinic by their general practitioner between January 2002 and December 2006 were included. Fertility care was provided according to the national Dutch fertility guidelines. Data on diagnosis, treatment, mode of conception and pregnancy outcome were documented. If follow-up data were missing, couples were contacted. Cumulative pregnancy curves were constructed for the whole cohort and per diagnostic group. RESULTS: As per December 2008 the overall ongoing pregnancy rate was 72.0% (n = 1001). Almost half of the pregnancies were conceived spontaneously (45.6%), 19.2% after ovulation induction (OI), 14.0% after intrauterine insemination (IUI) and 21.2% after IVF. A quarter (n = 349) of couples received IVF treatment, which was successful in 60% of cases. IVF had the largest contribution to ongoing pregnancies in patients with 'tubal factor', 'endometriosis' and 'male factor' (45, 45 and 37%, respectively) while in couples with 'unexplained subfertility' and 'ovulation disorders' the contribution to ongoing pregnancies of IVF was limited (13 and 4.5%, respectively). CONCLUSIONS: In a cohort of subfertile couples, most pregnancies were conceived spontaneously. The contribution of IVF to ongoing pregnancy rates was comparable to those of OI and IUI. Compared with the pre-IVF era, couples with 'endometriosis', 'tubal factor' and 'male subfertility' have benefited most from its introduction.
Assuntos
Fertilização in vitro , Infertilidade/terapia , Taxa de Gravidez , Adulto , Estudos de Coortes , Feminino , Humanos , Infertilidade/epidemiologia , Masculino , GravidezRESUMO
BACKGROUND: A substantial number of subfertile couples discontinues fertility care before achieving pregnancy. Most studies on dropouts are related to IVF. The aim here is to examine dropout rates at all stages of fertility care. METHODS: We analysed a consecutive cohort of 1391 couples, referred to our secondary care hospital between January 2002 and December 2006. Discontinuation rates were studied at six stages. Stage I: immediately after first visit, Stage II: during diagnostic workup, Stage III: after finishing diagnostic workup but before treatment, Stage IV: during or after non-IVF treatment, Stage V: during IVF, Stage VI: after at least 3 cycles of IVF. Reasons to discontinue and spontaneous pregnancy rates after discontinuation were secondary outcomes. RESULTS: In our cohort 319 couples dropped out of fertility care, 76.8%, [95% confidence interval (CI): 72.2-81.4] on their own initiative and 23.2% (95% CI: 18.6-27.8) on doctor's advice. Percentage (95% CI) of couples discontinuing per stage were: Stage I 6.0% (3.4-8.6), Stage II 3.4% (1.5-5.5), Stage III 35.7% (30.5-41.0), Stage IV 23.5% (18.9-28.2), Stage V 17.9% (13.7-22.1) and Stage VI 13.5% (9.7-17.2). Main reasons for dropout (%, 95% CI) were 'emotional distress' (22.3%, 17.7-26.8), 'poor prognosis' (18.8%, 14.5-23.1) and 'reject treatment' (17.2%, 13.1-21.4). The spontaneous ongoing pregnancy rate after discontinuation was 10% (6.7-13.3). CONCLUSION: About half of the couples stopped before any fertility treatment was started and one-third stopped after at least one IVF cycle. The main reasons for withdrawal were emotional distress and poor prognosis. This insight may help to improve quality of patient care by making care more responsive to the needs and expectations of subfertile couples.
Assuntos
Fertilização in vitro/estatística & dados numéricos , Infertilidade/terapia , Serviços de Saúde Reprodutiva/estatística & dados numéricos , Adulto , Estudos de Coortes , Feminino , Fertilização in vitro/psicologia , Humanos , Infertilidade/diagnóstico , Infertilidade/psicologia , Estudos Longitudinais , Masculino , Pacientes Desistentes do Tratamento/psicologia , Pacientes Desistentes do Tratamento/estatística & dados numéricos , Prognóstico , Estresse Psicológico/prevenção & controle , Recusa do Paciente ao Tratamento/estatística & dados numéricosRESUMO
Previous studies suggest beneficial effects of aerobic exercise on executive functions, which are a core deficit in ADHD. The aim of the present fMRI study was to investigate acute effects of aerobic exercise on inhibitory control and related brain activation in adult patients with ADHD. 23 patients and 23 matched healthy controls performed on a Go/No-go task in an MRI scanner, following both, an exercise condition involving 30 min of cycling at moderate intensity, and a control condition. ADHD patients compared to healthy controls showed increased brain activation during successful inhibition in the exercise compared to the control condition in parietal, temporal, and occipital regions. Exercise did not improve behavioral performance in either group, but in ADHD patients, exercise-related increases in brain activation and behavioral task performance (i.e., correct inhibition rate) negatively correlated with correct inhibition rate in the control condition. Thus, patients with worse inhibition performance showed stronger exercise-related enhancements, indicating that the lack of improvements on the behavioral level for the whole patient group could be due to ceiling effects. Our findings might be an important step in understanding the neural basis of exercise effects and could, in the long term, help in developing alternative treatment approaches for ADHD.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Encéfalo , Exercício Físico , Inibição Psicológica , Imageamento por Ressonância Magnética , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico por imagem , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Transtorno do Deficit de Atenção com Hiperatividade/terapia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Feminino , Humanos , MasculinoRESUMO
BACKGROUND: The aim of the present study was to objectively assess the physical activity levels of patients after tumor prosthesis implantation with two objective measurement devices. METHODS: The DynaPort ADL monitor permitted up to 24 hr monitoring of lower-extremity physical activities in daily life with respect to posture and locomotion. The step activity monitor (SAM) was worn for a whole week to collect the daily number of gait cycles. The devices were worn during the waking hours by 22 patients with knee prostheses after wide tumor resection. RESULTS: In the MSTS and TESS scores the patients achieved over 80% of the maximum score indicating a good clinical outcome. The most prominent activity was sitting which accounted for 54 +/- 18% of the recorded time, followed by standing (27 +/- 16%), locomotion (10 +/- 6%), and lying (8 +/- 6%). During locomotion, the average walking activity accumulated to 4,786 +/- 1,770 step cycles per day (range 2,045-8,135) corresponding to a yearly 1.75 million steps. There was no significant correlation between clinical scores and step count measures. CONCLUSIONS: Even though this activity level was lower than for a group of healthy adults it was comparable to the activity level for other patients, for example, with hip arthroplasty as reported in the literature.
Assuntos
Neoplasias Ósseas/cirurgia , Prótese do Joelho , Salvamento de Membro , Atividade Motora , Atividades Cotidianas , Adolescente , Adulto , Idoso , Feminino , Fêmur/cirurgia , Humanos , Locomoção , Masculino , Pessoa de Meia-Idade , Monitorização Ambulatorial , Tíbia/cirurgiaRESUMO
Systemic administration of the cytokine, TGF beta 1, profoundly antagonized the development of polyarthritis in susceptible rats. TGF beta 1 administration (1 or 5 micrograms/animal), initiated one day before an arthritogenic dose of streptococcal cell wall (SCW) fragments, virtually eliminated the joint swelling and distortion typically observed during both the acute phase (articular index, AI = 2.5 vs. 11; P less than 0.025) and the chronic phase (AI = 0 vs. 12.5) of the disease. Moreover, TGF beta 1 suppressed the evolution of arthritis even when administration was begun after the acute phase of the disease. Histopathological examination of the joint revealed the systemic TGF beta 1 treatment greatly reduced inflammatory cell infiltration, pannus formation, and joint erosion. Consistent with the inhibition of inflammatory cell recruitment into the synovium, TGF beta 1 reversed the leukocytosis associated with the chronic phase of the arthritis. Control animals subjected to the same TGF beta 1 dosing regimen displayed no discernable immunosuppressive or toxic effects even after 4 wk of treatment. These observations not only provide insight into the immunoregulatory effects of TGF beta, but also implicate this cytokine as a potentially important therapeutic agent.
Assuntos
Artrite/prevenção & controle , Fator de Crescimento Transformador beta/uso terapêutico , Doença Aguda , Animais , Artrite/tratamento farmacológico , Artrite/patologia , Parede Celular/imunologia , Doença Crônica , Contagem de Leucócitos/efeitos dos fármacos , Ratos , Ratos Endogâmicos Lew , Streptococcus/imunologia , Fator de Crescimento Transformador beta/efeitos adversosRESUMO
Recent evidence indicates that astrocytes have a wide range of functions, usually attributed to cells of the immune system, which are critical for maintaining a balanced homeostatic environment in the central nervous system (CNS). Moreover, these cells are known to participate in inflammatory events within the CNS by secreting cytokines such as transforming growth factor-beta (TGF-beta). In this study we have investigated the ability of TGF-beta to influence astrocyte functions. TGF-beta 1 mRNA is constitutively expressed by astrocytes in vitro, and when cultures are stimulated with exogenous TGF-beta 1 an increase in the expression of this mRNA can be shown, suggesting both autocrine and paracrine regulation. In in vitro assays, TGF-beta 1 is chemotactic for astrocytes in a dose-dependent fashion and inhibits astrocyte proliferation. These results indicating signal transduction by TGF-beta 1-prompted studies to explore receptor-ligand interactions on isolated astrocyte populations. In a receptor binding assay, we demonstrate that astrocytes appear to express three distinct TGF-beta receptor subtypes with nearly 10,000 receptors per cell. Thus, TGF-beta may play an important role in regulating astrocyte functions pivotal to the evolution of intracerebral immune responses including recruitment and activation of glial cells at local inflammatory sites within the CNS.
Assuntos
Astrócitos/fisiologia , Fator de Crescimento Transformador beta/fisiologia , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Fatores Quimiotáticos/fisiologia , Interleucina-1/farmacologia , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/farmacologiaRESUMO
Tissue injury elicits an inflammatory response, one element of which is the activation of the local macrophage population. Macrophages are recognized as the source of multiple growth-regulating proteins, and are thus thought to play an important role in wound healing. Injury to the lung by exposure to oxidant gases, particulates, chemicals or drugs is often followed by replication of the cells of the alveoli. The growth-regulating proteins released by alveolar macrophages (AM) may be one mechanism which controls the proliferation of these cells. This article describes the AM growth factors, the cell types which they affect, and the injuries known to cause their release. In view of the multiplicity and overlapping functions of the macrophage growth factors, potential mechanisms which might regulate the growth response of the surrounding cells are also considered.
Assuntos
Substâncias de Crescimento/fisiologia , Lesão Pulmonar , Macrófagos/fisiologia , Alvéolos Pulmonares/fisiologia , Substâncias de Crescimento/biossíntese , Humanos , Pulmão/metabolismoRESUMO
The inhibition of light emitted by the bioluminescent bacterium, Vibrio fischeri, is the basis for several toxicity bioassays. The inhibitory effects of 81 chemicals, after 5 min contact time, were studied at eight concentrations using reagents from three commercial assay systems (ToxAlert 10, Microtox and LUMIStox). Solubility in water was the limiting factor in determining the selection of chemicals for study. The effective nominal concentrations (EC) resulting in 20, 50 and 80% inhibition were determined using Ln dose/Ln gamma plots and the results obtained for each system were compared by linear regression. The chemical concentrations producing 10-90% inhibition extended over 9 orders of magnitude and ranged from a minimum of 0.001 ppm to a maximum of 1,000,000 ppm. The toxicity of many chemicals was apparently related to their pH in solution and at high chemical concentrations, to osmotic imbalance. The fact that the same operator tested the same solutions simultaneously on three different systems reduced sources of error and variability and improved the consistency and reliability of the results. Only five compounds gave EC 50s that varied more than three-fold between assays. These data provide comparisons of toxicity that have not been previously available and demonstrate that, when used under standardised conditions, these bioluminescence-based toxicity assays produce very similar results.
Assuntos
Compostos Orgânicos/toxicidade , Photobacterium/metabolismo , Testes de Toxicidade , Vibrio/metabolismo , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio , Modelos Lineares , Medições Luminescentes , Padrões de Referência , Sensibilidade e Especificidade , SolubilidadeRESUMO
Cytoplasmic retinoic acid binding protein (cRABP) is present in human fetal pancreas and becomes nondetectable in the normal adult pancreas. The binding protein for retinoic acid becomes apparent again in pancreatic cancer. Similar fluctuations in the content of cRABP occur in the hamster. The binding protein is undetectable in the normal adult hamster pancreas, while it was detected in several transplantable adenocarcinomas in the Syrian golden hamster.
Assuntos
Adenocarcinoma/análise , Proteínas de Transporte/análise , Neoplasias Pancreáticas/análise , Adenocarcinoma/patologia , Envelhecimento , Animais , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Cricetinae , Feminino , Feto , Humanos , Mesocricetus , Pâncreas/análise , Neoplasias Pancreáticas/patologia , Gravidez , Receptores do Ácido RetinoicoRESUMO
Recently we reported that feline and canine dental calculus fluoresced pink to red under long wavelength ultraviolet light due to the presence of porphyrin. Here we report the observation of such fluorescence in 30 of 30 cats, 30 of 30 dogs, and 8 of 13 supragingival samples and 5 of 5 subgingival samples of humans. The fluorescence spectra of the calculus dissolved in 9 M HCl show that it is due to three distinct metal-free porphyrins. Similar fluorescence is obtained from bacterial cultures grown from calculus deposits of cats and dogs and bacteria grown on blood agar containing hemin and vitamin K1. The results of the bacterial culture study suggest that the metal-free porphyrin is produced by bacteria in the mouth. The clinical observation of fluorescence can be used for diagnosis.
Assuntos
Doenças do Gato/microbiologia , Cálculos Dentários/veterinária , Doenças do Cão/microbiologia , Animais , Bactérias Anaeróbias/isolamento & purificação , Doenças do Gato/metabolismo , Gatos , Cálculos Dentários/química , Cálculos Dentários/microbiologia , Doenças do Cão/metabolismo , Cães , Fluorescência , Humanos , Porfirinas/análise , Espectrometria de Fluorescência/veterináriaRESUMO
The application of scanning transmission electron microscopy (STEM) to crystalline defect analysis has been extended to dislocations. The present contribution highlights the use of STEM on two oppositely signed sets of near-screw dislocations in hcp α-Ti with 6wt% Al in solid solution. In addition to common systematic row diffraction conditions, other configurations such as zone axis and 3g imaging are explored, and appear to be very useful not only for defect analysis, but for general defect observation. It is demonstrated that conventional TEM rules for diffraction contrast such as g·b and g·R are applicable in STEM. Experimental and computational micrographs of dislocations imaged in the aforementioned modes are presented.
Assuntos
Processamento de Imagem Assistida por Computador/métodos , Microscopia Eletrônica de Transmissão e Varredura/métodos , Simulação por Computador , Microscopia Eletrônica de Transmissão e Varredura/instrumentaçãoRESUMO
The type II pneumocyte plays a principle role in the maintenance and repair of the pulmonary alveolar epithelium by increasing its rate of proliferation under conditions of epithelial damage. This investigation examined the role of the alveolar macrophage in the control of type II cell division through its ability to produce specific growth factors when activated in vitro. Type II cells were isolated from adult male rabbits and cultured in the presence of media and matrix that support cell proliferation. Proliferation was assessed by cell counting and pulsing with [3H]thymidine, followed by measurements of labeling index and TCA-insoluble radioactivity. Alveolar macrophages were cultured in serum-free media in the presence of a particulate stimulus. Conditioned media was diluted and added to type II cell cultures. Conditioned media from stimulated macrophage cultures was found to double basal type II cell proliferation, whereas media from unstimulated macrophage cultures had no effect. Macrophage production of type II cell growth-promoting activity was dependent on the concentration of the stimulus and the length of the incubation. Investigation into the identity of the growth-regulating protein established that it is heat labile, insensitive to reduction and acidic conditions, and sensitive to trypsin digestion. Its molecular weight appears to be greater than or equal to 25 kD. Addition of several characterized growth factors to type II cell cultures demonstrated that other known growth-promoting products of macrophages do not act as type II cell growth factors. The evidence presented suggests that in vitro activated alveolar macrophages produce a type II cell growth factor that may play a critical role in mediating repair of the alveolar epithelium.
Assuntos
Substâncias de Crescimento/metabolismo , Pulmão/citologia , Macrófagos/metabolismo , Alvéolos Pulmonares/imunologia , Animais , Divisão Celular , Células Cultivadas , Fenômenos Químicos , Química , Células Epiteliais , Pulmão/crescimento & desenvolvimento , Ativação de Macrófagos , Macrófagos/imunologia , Masculino , Peso Molecular , Coelhos , Ultrafiltração , Zimosan/farmacologiaRESUMO
Protein synthesis by isolated rabbit type II pneumocytes was evaluated by incorporation of labeled amino acids, gel electrophoresis, and fluorography. Type II alveolar epithelial cells preferentially synthesize a small number of proteins immediately following isolation and simultaneously exhibit a depression of all other protein synthesis. Examination of the time course of the appearance and decline of these proteins showed them to be actively synthesized during the first 14 h after isolation. Decline in their production was accompanied by a gradual enhancement in the synthesis of other proteins. Actin synthesis was not measurable 1 h after isolation, but increased to 9% of total label incorporated by 14 h. This recovery was independent of attachment to an extracellular matrix. Treatment with actinomycin D immediately following cell isolation abolished the synthesis of these proteins, suggesting a requirement for active mRNA production. A subset of these proteins are induced by heat treatment of cultured type II cells. The half-life, intracellular localization, isoelectric points, apparent molecular weights, and heat inducibility of this group of proteins are similar to stress proteins found in other mammalian systems. These stress proteins are unique in that their synthesis is induced by the cell isolation process. Possible mechanisms by which cell isolation may induce the stress response are discussed.
Assuntos
Separação Celular , Pulmão/metabolismo , Estresse Fisiológico/metabolismo , Animais , Fenômenos Químicos , Química , Eletroforese/métodos , Proteínas de Choque Térmico/biossíntese , Proteínas de Choque Térmico/isolamento & purificação , Pulmão/patologia , Masculino , Coelhos , Estresse Fisiológico/patologiaRESUMO
Bacterial cell wall-induced arthritis in experimental animals is dependent on mononuclear cell infiltration and accumulation. These mononuclear cells secrete cytokines which promote synovial hyperplasia and erosive destruction of bone and cartilage. Whereas local administration of cytokines may exacerbate these events, systemic administration of TGF-beta or gamma IFN effectively suppresses both the acute and chronic phases of the disease.