Cell surface receptors in lymphoid cells: from cytochemistry to molecular biology and from a phenotype to a function.
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Animals↗
Biomedical subjects
N Jacobs
Publications and source records attributed to N Jacobs.
Graft-versus-host disease associated T helper cell responses specific for minor histocompatibility antigens are mainly restricted by HLA-DR molecules.
Graft-versus-host reactions are mediated by subpopulations of donor T cells and can be attributed to host specific minor histocompatibility (mH) antigens. We isolated strong anti-host mH antigen proliferative T cell lines, LG2, PN2, and LH3, from three patients suffering from acute graft-versus-host disease (GVHD). To study the role of the different major histocompatibility complex (MHC) molecules in the anti-host mH antigen specific proliferative response, the reactivities of the three T cell lines were analysed in primed lymphocyte test (PLT) assays against panels of stimulator cells obtained from unrelated blood donors. LG2 and LH3 stimulating determinants were commonly detected in the unrelated panel, whereas the PN2 T cell line recognized a rare specificity. The responses were associated with the presence of self HLA-DR molecules on the stimulator cells, although not all DR sharing stimulator cells were recognized. The proliferative responses of LG2, LH3 and PN2 cells could be blocked by monoclonal antibodies (MoAbs) against HLA-DR, but not by MoAbs against HLA-A/B/Cw, HLA-DQ or -DP. At the responder cell level, depletion of CD4 cells as well as blocking with CD4 specific MoAbs abrogated the specific responses of the three T cell lines. Our findings suggest that anti-host Th cell responses activated in the acute phase of GVHD are directed against both frequent and rare mH antigens, are mediated by CD4 + ve class II restricted Th cells, and use the HLA-DR molecule as a common restriction element for mH antigen presentation.
Acute Disease↗
Continuing experience with the fetal acoustic stimulation test.
Antepartum fetal heart rate testing remains a useful method with which to assess fetal well-being in high-risk pregnancies. Recently the adjunctive use of transabdominal acoustic stimulation was proven effective in reducing the number of nonreactive nonstress tests (NSTs) without changing the predictive reliability of the test. Our continuing experience with this method involved 1,503 women undergoing 3,935 tests. A reactive test occurred in 93%, and the fetal death rate was 1.3/1,000. In an attempt to evaluate the incidence of mortality in a large population, data from the current investigation were pooled with those from other reports from our institution. In our aggregate experience of 7,763 tests, fetal death occurred within seven days of a reactive test with an incidence of 1.9/1,000 in patients receiving acoustic stimulation. This finding contrasts favorably with a death rate of 1.6/1,000 in fetuses with spontaneous reactivity. Fetal acoustic stimulation testing seems to offer advantages over the more traditional NST, and the predictive values of normal tests seem to be equivalent.
Acoustic Stimulation↗
Antepartum fetal surveillance in the patient with decreased fetal movement.
Whenever a patient has the subjective perception of decreased fetal movement, prompt evaluation in the form of antepartum fetal surveillance has been undertaken. The purpose of this report is to describe our experience with 489 pregnant women who came between Jan. 1 and Dec. 31, 1985 to our Antepartum Fetal Surveillance Clinic with this complaint alone or in association with another indication for fetal surveillance. Overall, 838 nonstress tests were performed, and the results were reactive, 93.2%; nonreactive, 6.8%; and fetal heart rate decelerations, 6.1%. Comparison of the first nonstress test results between those with decreased fetal movement alone or in combination with another diagnosis demonstrated a similar incidence of nonreactivity and fetal heart rate decelerations. In those patients whose indication was decreased fetal movement alone, there was a 3.7 times greater likelihood of diminished amniotic fluid volume. When the last test within 7 days of delivery was analyzed, the decreased fetal movement alone group had a lower incidence of cesarean delivery, cesarean delivery for fetal distress, and Apgar scores less than 7 than patients with an additional indication for testing. In summary, decreased fetal movement continues to be an acceptable indication for fetal surveillance. Based on our retrospective experience, the most reasonable approach appears to be a combination of nonstress test and amniotic fluid volume assessment. Unless the patient has additional indications for fetal surveillance, the patient with decreased fetal movement with a reactive nonstress test and a normal amniotic fluid volume does not appear to warrant additional testing.
Amniotic Fluid↗
Nutritionally variant Streptococcus pyogenes from a periorbital abscess.
A nutritionally variant Streptococcus pyogenes strain was isolated from a periorbital abscess. The organism was identified with the use of three rapid biochemical test kits, and the group A antigen was detected by conventional serology as well as direct antigen detection tests.
Abscess↗
The four-quadrant assessment of amniotic fluid volume: an adjunct to antepartum fetal heart rate testing.
Amniotic fluid volume assessment using a semiquantitative four-quadrant technique, the amniotic fluid index, was evaluated in relationship to fetal heart rate (FHR) testing and perinatal morbidity in 330 high-risk pregnancies. An inverse relationship was found between the amniotic fluid index and nonreactive nonstress tests (NST), FHR decelerations, meconium staining, cesarean section for fetal distress, and low Apgar scores. More important, adverse perinatal outcome was significantly more frequent with diminished compared with normal amniotic fluid volume, even if the NST was reactive.
Amniotic Fluid↗
Normal human locomotion.
A study of normal locomotion requires an understanding of both the movements and the force actions involved. This is equally true in appreciating the problems of pathological gait. The gait cycle is described in terms of the significant events which occur during both the stance and swing phases. The basic principles underlying the analysis of force actions in walking are briefly described. A simple example of force actions in the elbow joint is considered and the analysis extrapolated to provide a general statement regarding locomotion. This relates to the muscle actions required to resist turning actions at joints due to the force effects in walking and the corresponding forces in the joints themselves. The conventional display of information relating to joing actions is considered and compared with the actual situation, "Stick diagrams" of motion in the sagittal plane are used to identify and discuss the actions at the joints of the leg in walking. Comparisons are made between this and pathological gait--in particular that of the above-knee amputee.
Amputees↗