Splenic lymphocytopoiesis and migration pattern of splenic lymphocytes.
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In normal young pigs splenic lymphocytes were selectively labelled by injecting tritiated cytidine into a splenic artery. 10 h later several lymphoid and non-lymphoid organs were investigated for spleen-derived lymphocytes by autoradiography. The relative and absolute organ distribution of the labelled cells was determined. Labelled lymphocytes appeared rapidly in the peripheral blood reaching a mean labelling index of 4.8%. More splenic lymphocytes were found in thymus dependent areas than in thymus independent areas of lymphoid organs. Nearly 40% of all emigrated lymphocytes homed to lymph nodes and only about 1% in the thymus. A surprisingly high number of splenic lymphocytes were located in the bone marrow and the lung.
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Interstitial cell migration was characterized in Hydra vulgaris (formerly H. attenuata) and the effects of axial position and tissue injury on migration were investigated. Migrating cells were labeled with the thymidine analog, bromodeoxyuridine, and grafted into unlabeled host polyps. Alternatively, cells were labeled directly in hosts with the fluorescent, carbocyanine dye, DiI. The results show that cell migration appeared constrained to proximal (toward the basal disk) or distal (toward the tentacles) movements, but were never lateral. Some cells moved bidirectionally. The fastest migrating cells moved an average of 28 microns/hr. Two to six percent of the gastric region interstitial cells migrated in 1 day and accumulated throughout the body column. In grafted polyps, an average of eight cells emigrated from midgastric regions every hour. Tissue injury had no observed effect on the amount of cell migration. Cells emigrating from midgastric regions showed a preference for distal accumulation, and this bias was enhanced when migrating cells originated from more distal positions in the polyp. Proximally derived tissue grafted to a more distal position also showed similar, preferential distal migration, indicating that interstitial cell migration patterns are dependent upon their position in the body column and not upon their origin. Migrating interstitial cells are slower moving and less numerous than migrating nematocytes in H. vulgaris, but since their migration patterns are similar, the migration of both cell types may be influenced by the same directional cues.
The kinetics of ameloblast cells in continuously growing guinea pig molars were studied using autoradiography. The results showed that there was no direct relationship between ameloblast migration rate and ameloblast production rate, which indicated that ameloblasts actively migrated coronally. It was found that ameloblast migration rate was maximal at the root apex, and then reduced to a minimum value as the ameloblasts left their proliferative compartment and migrated coronally. A multiple regression model was found to be the most suitable one to represent the ameloblast migration pattern.
In the present study, the role of the periosteum in mandibular growth was investigated. The orientation of the superficial bony spicules of rabbit mandibles was determined on dry skulls after perfusion of the animals with an India ink solution. The spicular orientation in the ramus area appeared to be toward the condyle, rostrally toward the incisors, and caudally toward the angular region. The behavior, during growth, of the periosteum in the caudal mandibular half was studied by implantation of metal periosteal and bone markers. A series of cephalograms revealed the migration pattern of the periosteal markers, and by that the migration pattern of the periosteum. It can be concluded that both the pattern of the superficial bony spicules and the periosteal migration pattern suggest a possible influence of the periosteum on mandibular growth.
The direct linkage of the B cell maturation process and infiltration of the thymus with mature B cells was studied in SJL mice. Phenotypically and functionally, B cells in the thymus of old SJL mice are mature B cells; IgM+, IgD+, Ly-1-, and evince a high proliferative response to lipopolysaccharide and a low one to dextran sulphate. Memory B cells can be found in the thymus of mice immunized with T-dependent or T-independent antigens. Chronic depletion and B cell maturation arrest induced by fractionated total lymphoid irradiation or by neonatal splenectomy eliminate B cells from the thymus and block their migration from the periphery to the thymus. When examined in adoptive transfer experiments, thymus B cells were found to possess a normal migration pattern and homing receptors; their migration pattern did not differ from that of lymph node or splenic B cells. It is evident, therefore, that the large number of normal functioning B cells in the thymus of SJL mice reflects a massive infiltration of the thymus by mature B cells from the periphery due to thymus dysfunction rather than to an abnormal in situ differentiation of intrathymic B cell precursors.
Characteristic roentgenographic patterns of femoral head migration occur in osteoarthritis of the hip. In a study of 100 patients superolateral migration was noted in 15, superomedial in 48, superior migration of intermediate type in 15, and medial displacement of the femoral head in 22. Correlation with pathologic specimens obtained following total hip replacements and comparison with patterns of femoral head migration in rheumatoid arthritis were accomplished. It would appear that anatomic features of the acetabulum are of prime importance in the determination of the type of femoral head displacement complicating osteoarthritis.
The specific aim of this study was to extend the analysis of retirement migration patterns to older Blacks. The 1980 Census public use sample A provided the data for this analysis. Because of their strong initial southern settlement and their labor force out-migration patterns in this century, many older Black migrants are "provincial return migrants" to the South, a migrant type that may decline among Blacks in the future. There is also a regional counterstream migration pattern among older Black migrants. Out-migrants in this stream from the South have elevated indicators of dependency. Suggestions are made for other related studies of Black retirement migration.
A total of 64 Escherichia coli strains of the O1 serogroup were tested for the migration pattern of their lipopolysaccharides (LPS) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. O1:K1 and O1:K51 strains of the OMP5 outer membrane protein pattern possessed LPS with a doublet pattern (O1A1) or the lowermost band of the O1A1 doublet (O1A2). O1:K1 strains of the OMP9 pattern possessed LPS referred to as O1A, which corresponded to the uppermost band of the O1A1 doublet pattern. A few O1:K? strains possessed LPS of different migration patterns (O1B and O1C). O1A and O1A1 LPS were indistinguishable by chemical techniques, and both reacted with each of 10 different monoclonal antibodies tested. However, O1A1 had an additional epitope within the additional band in each doublet, as demonstrated by adsorption experiments with hyperimmune rabbit sera followed by Western blotting. Furthermore, purified polysaccharide from O1A bacteria was incapable of inhibition in enzyme-linked immunosorbent assays performed with O1A1 LPS as antigen and adsorbed, specific anti-O1A1 antibodies, whereas O1A1 polysaccharide inhibited this reaction. O1B and O1C LPS differed in all respects tested, including chemical composition, from O1A and O1A1 LPS.
This paper reports results from a punctual epidemiological survey performed in San Juan, at Bermejo, a rural village located 100 km east from the provincial capital, in December 1987. The village had been rebuilt after almost complete destruction by an earthquake, in 1977. According to a census performed by local Primary Health Care Agents, there were 82 households, where 72 (88%) of them were inhabited, with a total human population of 198 people. Forty-eight from those inhabited dwellings (67%) were visited, and a general questionnaire was completed. Information gathered included, sex, age, working activity, number of people and domestic animals at the house, construction patterns of houses and outdoor premises, resting habits of animals, specially dogs, domestic use of insecticides and migration patterns of inhabitants. A timed collection of triatomines (man-hour method) was undertaken in 17 out of 48 of the visited households. Sampled triatomines were kept and classified by collection site, instar, and sex at the field. Species identification, microscopical examination of fecal contents to detect trypanosomes and blood-meals identification, were performed at the laboratory. Sixty-nine per cent (33/48) of the dwellings were "ranchos" with mud-brick ("adobe") and cane walls, roofs made of cane and mud dirt floors. The remainder were as follows: 11 (23%), partially improved houses and 4 (8%) had brick walls and were tiled or had zinc roofs. Data of migration patterns of local population were obtained in 31 (65%) out of 48 households. Seasonal movements within San Juan Province, mainly related to vintage were reported in 20/31 (65%) families.(ABSTRACT TRUNCATED AT 250 WORDS)