RESUMO
Volume analysis of purified human blood monocytes revealed distinct populations of large and small cells. Computer curve fitting suggested a third, intermediate-sized population. These monocytes were designated M1, M2, and M3 in order of increasing size, and their approximate volumes were 150, 250, and 480 micron3, respectively. The three subpopulations were present in all 30 normal individuals tested. Two new techniques were developed that separate monocytes into M1 + M2 and M3 fractions; one used preferential incorporation of carbonyl iron particles by M3 cells and the other used the selective aggregation of M3 cells by thrombin in the presence of platelets. The chemotactic response to zymosan-activated human serum by total monocytes, M1 + M2 monocytes, and M3 monocytes was determined by the agarose plate method. In all experiments M3 monocytes were 10-fold more responsive than M1 + M2 monocytes and were significantly more so than total monocytes. These findings suggest that M3 cells are the major subpopulation capable of directional migration. This investigation establishes the existence of volumetrically definable subpopulations of human monocytes that are functionally distinct.
Assuntos
Quimiotaxia de Leucócito , Monócitos/citologia , Separação Celular , Humanos , Monócitos/classificação , Monócitos/fisiologiaRESUMO
Suspensions of human lymphocytes and monocytes separated by the Ficoll-hypaque method from the peripheral blood show a Coulter volume distribution, measured with a multiparameter cell sorter, characterized by a minor peak at 500 mu3, containing 5-15% of the cells, and a major peak at 200 mu3. Using fluorescent latex particles we have found that the monocytes, the cells that ingest the latex particles, all lie in the 500 mu3 peak; conversely, all of the cells in the 500 mu3 peak are monocytes. When the cell suspensions are incubated, the monocytes increase both the average volume and in absolute numbers. The number of monocytes approximately doubles during 3 days of incubation, when it reaches its maximum value. At that time we have found that all of the monocytes lack receptors for sheep red blood cells and all possess receptors for human gamma-globulin. The increase in monocyte number appears, therefore, to arise from the enlargement of "monocyte presursors" that resemble lymphocytes in volume and resemble both the monocytes and the B lyphocytes with respect to surface sheep red blood cell and human gamma-globulin receptors.
Assuntos
Linfócitos/citologia , Monócitos/citologia , Animais , Autoanálise , DNA/análise , Eritrócitos/imunologia , Testes de Hemaglutinação , Látex , Linfócitos/imunologia , Microscopia/métodos , Microesferas , Monócitos/imunologia , Ovinos/imunologia , Coloração e RotulagemRESUMO
Volumetrically distinct subpopulations of peripheral blood monocytes, termed M1, M2, and M3, were identified in healthy normal adults and children. Because normal neonates have abnormal monocyte chemotaxis, it was determined whether monocyte subpopulations have different chemotactic capabilities and, if so, whether chemotactically active subpopulations were quantitatively deficient in neonates. Chemotaxis tests with zymosan-activated normal human serum as the chemoattractant and purified monocyte subpopulations revealed that large M3 monocytes were capable of significantly more directed migration than were small M1 and M2 monocytes. Volumetric analysis of monocytes from normal newborns rather than demonstrating an absence of M3 cells revealed that these cells were the predominant monocyte subpopulation. Therefore, we conclude that the impaired chemotactic ability of newborn monocytes is due to a functional rather than quantitative deficiency of M3 cells.
Assuntos
Quimiotaxia de Leucócito , Recém-Nascido , Monócitos/classificação , Adulto , Fatores Etários , Fatores Quimiotáticos/farmacologia , Criança , Pré-Escolar , Humanos , Contagem de Leucócitos , Monócitos/fisiologia , Zimosan/farmacologiaRESUMO
The presence of irregular incisal edges, a worn or abraded dentition, and imbalances in tooth morphology compromise a harmonious esthetic smile. A team approach is indicated after extensive orthodontic or prosthetic treatment to reach a final cosmetic result. Intentional changes in tooth form by recontouring provide an improved outcome. This article presents the components of a harmonious smile, evaluation, guidelines and a stepwise approach for the esthetic recontouring of anterior teeth. Two cases illustrate the effects that are achieved with this methodology.
Assuntos
Estética Dentária , Dente/anatomia & histologia , Adulto , Prótese Dentária , Humanos , Incisivo/patologia , Masculino , Ortodontia Corretiva , Planejamento de Assistência ao Paciente , Equipe de Assistência ao Paciente , Sorriso , Abrasão Dentária/terapia , Preparo do Dente , Resultado do TratamentoRESUMO
We examined the impact of maternal use of different household cooking fuels in India on low birth weight (LBW<2500g), and neonatal mortality (death within 28 days of birth). Using cross-sectional data from India's National Family Health Survey (NFHS-3), we separately analyzed the prevalence of these two outcomes in households utilizing three types of high-pollution fuels for cooking - biomass, coal, and kerosene - using low-pollution fuels (gas and biogas) as the comparison "control" group. Taking socioeconomic and child-specific factors into account, we employed logistic regression to examine the impact of fuel use on fetal and infant health. The results indicate that household use of high-pollution fuels is significantly associated with increased odds of LBW and neonatal death. Compared to households using cleaner fuels (in which the mean birth weight is 2901g), the primary use of coal, kerosene, and biomass fuels is associated with significant decreases in mean birth weight (of -110g for coal, -107g for kerosene, and -78g for biomass). Kerosene and biomass fuel use are also associated with increased risk of LBW (p<0.05). Results suggest that increased risk of neonatal death is strongly associated with household use of coal (OR 18.54; 95% CI: 6.31-54.45), and perhaps with kerosene (OR 2.30; 95% CI: 0.95-5.55). Biomass is associated with increased risk of neonatal death among infants born to women with no more than primary education (OR 7.56; 95% CI: 2.40-23.80). These results are consistent with a growing literature showing health impacts of household air pollution from these fuels.
Assuntos
Poluição do Ar em Ambientes Fechados/efeitos adversos , Culinária , Mortalidade Infantil , Recém-Nascido de Baixo Peso , Adulto , Biomassa , Carvão Mineral , Características da Família , Feminino , Habitação , Humanos , Índia/epidemiologia , Recém-Nascido , Querosene , Masculino , Razão de Chances , Adulto JovemAssuntos
Acidose/terapia , Bicarbonatos/uso terapêutico , Lactatos , Diálise Peritoneal , Soluções Tampão , HumanosRESUMO
We have studied the quasielastic 3He(e,e(')p)2H reaction in perpendicular coplanar kinematics, with the energy and the momentum transferred by the electron fixed at 840 MeV and 1502 MeV/c, respectively. The 3He(e,e(')p)2H cross section was measured for missing momenta up to 1000 MeV/c, while the A(TL) asymmetry was extracted for missing momenta up to 660 MeV/c. For missing momenta up to 150 MeV/c, the cross section is described by variational calculations using modern 3He wave functions. For missing momenta from 150 to 750 MeV/c, strong final-state interaction effects are observed. Near 1000 MeV/c, the experimental cross section is more than an order of magnitude larger than predicted by available theories. The A(TL) asymmetry displays characteristic features of broken factorization with a structure that is similar to that generated by available models.
RESUMO
Results of the Jefferson Lab Hall A quasielastic 3He(e,e'p)pn measurements are presented. These measurements were performed at fixed transferred momentum and energy, q=1502 MeV/c and omega=840 MeV, respectively, for missing momenta p(m) up to 1 GeV/c and missing energies in the continuum region, up to pion threshold; this kinematic coverage is much more extensive than that of any previous experiment. The cross section data are presented along with the effective momentum density distribution and compared to theoretical models.
RESUMO
Major changes in DNA distributions of two human neuroblastoma cell lines growing in vitro and in athymic nude mice occurred after treatment with cyclophosphamide. Pulse treatment of LA-N-1 cells in vitro with liver S-9-activated cyclophosphamide (10 micrograms/ml) caused approximately 50% cytotoxicity; flow microfluorometric analysis of surviving cells demonstrated an increased proportion of G2 + M cells and a decreased proportion of G1 cells, particularly at 48 hrs. Even though LA-N-1 tumors in nude mice did not regress after one dose of cyclophosphamide (250 mg/kg), the percent of G2 + M cells increased and the percent of G1 cells decreased 4-6 days after treatment; the percent of cells in S increased at 2 and again at 8 days. SK-N-MC cells were affected differently by cyclophosphamide. Pulse treatment of these cells in vitro with liver S-9-activated cyclophosphamide caused greater than 85% cytotoxicity and nearly complete elimination of cells in G2 + M at 24 and 48 hrs. Likewise, SK-N-MC tumors in nude mice regressed greater than 50% after cyclophosphamide, and the proportion of G2 + M cells decreased markedly 2-6 days after therapy. We conclude that cyclophosphamide can have different cytotoxic and cytokinetic effects on neuroblastomas. In addition, marked cytokinetic effects may occur even though changes in tumor size are minimal or not detectable.
Assuntos
Ciclofosfamida/farmacologia , DNA de Neoplasias/metabolismo , Neuroblastoma/metabolismo , Animais , Contagem de Células , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Interfase/efeitos dos fármacos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Fatores de TempoRESUMO
We report a virtual Compton scattering study of the proton at low c.m. energies. We have determined the structure functions P(LL)-P(TT)/epsilon and P(LT), and the electric and magnetic generalized polarizabilities (GPs) alpha(E)(Q2) and beta(M)(Q2) at momentum transfer Q(2)=0.92 and 1.76 GeV2. The electric GP shows a strong falloff with Q2, and its global behavior does not follow a simple dipole form. The magnetic GP shows a rise and then a falloff; this can be interpreted as the dominance of a long-distance diamagnetic pion cloud at low Q2, compensated at higher Q2 by a paramagnetic contribution from piN intermediate states.
RESUMO
We measured the cross section and response functions for the quasielastic 16O(e,e'p) reaction for missing energies 25< or =E(m)< or =120 MeV at missing momenta P(m)< or =340 MeV/c. For 25
RESUMO
We have measured the proton recoil polarization in the 4He(e-->,e(')p-->)4H reaction at Q(2)=0.5, 1.0, 1.6, and 2.6 (GeV/c)(2). The measured ratio of polarization transfer coefficients differs from a fully relativistic calculation, favoring the inclusion of a medium modification of the proton form factors predicted by a quark-meson coupling model. In addition, the measured induced polarizations agree reasonably well with the fully relativistic calculation indicating that the treatment of final-state interactions is under control.
RESUMO
The ratio of the electric and magnetic form factors of the proton G(E(p))/G(M(p)), which is an image of its charge and magnetization distributions, was measured at the Thomas Jefferson National Accelerator Facility (JLab) using the recoil polarization technique. The ratio of the form factors is directly proportional to the ratio of the transverse to longitudinal components of the polarization of the recoil proton in the elastic e(-->)p---> e(-->)p reaction. The new data presented span the range 3.5< Q(2)< 5.6 GeV(2) and are well described by a linear Q(2) fit. Also, the ratio sqrt[Q(2)] F(2(p))/F(1(p)) reaches a constant value above Q(2) = 2 GeV(2).