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Biomedical subjects

R Jacobson

Publications and source records attributed to R Jacobson.

At least 37 records · Page 2Linked to original sources
PubMed1984

Evidence for a stem cell common to hematopoiesis and its in vitro microenvironment: studies of patients with clonal hematopoietic neoplasia.

The origin and nature of cells forming the in vitro microenvironment in long-term cultures of human marrow were studied in five patients with clonal myeloproliferative disorders who were heterozygous for glucose-6-phosphatase dehydrogenase (G6PD). The results showed that cells in the adherent stromal layer forming the in vitro microenvironment were derived from the same clonal progenitors involved by the neoplasm in the four patients whose diseases originated in multipotent stem cells. In contrast, stromal cells were derived from normal progenitors in a patient with acute non-lymphocytic leukemia whose clone showed differentiative expression confined to cells in the granulocytic lineage. Mixing experiments demonstrated that the G6PD type displayed by the adherent marrow stromal cells was not obscured by contaminating non-adherent hematopoietic cells or marrow fibroblasts. The data suggest the existence of a pluripotent cell in normal hematopoiesis that gives rise to hematopoietic cells and to their micro-environment.

Adult↗
PubMed1984

Interdental thickness discrimination in myofascial pain dysfunction subjects.

Interdental thickness discrimination (ITD) was evaluated on twenty-eight normal subjects and twenty subjects with myofascial pain dysfunction (MPD). This evaluation was performed before and after a submaximal isometric clenching task sustained to pain tolerance. The results of the study demonstrate a significant difference in ITD ability at several test points between the normal and MPD subjects. The experimental variable of sustained submaximal clenching did not significantly alter the ITD ability of either subject group.

Adult↗
PubMed1984

The effect of sustained submaximal clenching on maximum bite force in myofascial pain dysfunction patients.

The effect of a sustained (30% maximum) isometric clenching task on the maximum voluntary bite force level was evaluated on normal jaw function subjects as well as on abnormal jaw function subjects (MPD patients). The results indicate that the MPD subjects had a lower maximum voluntary bite force level and a shorter endurance time when compared to normal subjects. Neither the control subjects nor the MPD subjects demonstrated a change in their brief MVBF after a 'fatigue inducing' task. These results suggest a lack of contractile element failure in the jaw closing muscles following sustained submaximal isometric clenching on a force transducer.

Adult↗
PubMed1984

Interleukin 1 production by peripheral blood mononuclear cells from leprosy patients.

Quantitation of interleukin 1 production by adherent mononuclear cells from peripheral blood was performed in patients with tuberculoid and lepromatous forms of leprosy. Cells from patients with tuberculoid leprosy either secreted interleukin 1 spontaneously or produced amounts within the normal range in response to lipopolysaccharide stimulation. Conversely, stimulated cells from lepromatous patients failed to produce interleukin 1 in 5 of 13 (38.5%) cases.

Adult↗
PubMed1984

Evidence for a multistep pathogenesis of a myelodysplastic syndrome.

Somatic cell genetic approaches utilizing the cellular mosaicism present in women heterozygous for glucose-6-phosphate dehydrogenase (G6PD) have provided information relevant to the pathogenesis of some neoplastic disorders. With these techniques, we studied a 61-year-old woman with a myelodysplastic syndrome. GdB/GdA heterozygosity was demonstrated in skin and cultured T lymphocytes, which exhibited both A and B type G6PD. In contrast, erythrocytes, platelets, granulocytes, and marrow nucleated cells displayed almost exclusively G6PD type B. In addition, 21 of 24 Epstein-Barr virus-transformed B lymphoblastoid lines that expressed a single immunoglobulin light chain showed only type B G6PD, suggesting that the stem cells involved by this disease were clonal and could differentiate to B lymphocytes as well as to mature granulocytes, erythrocytes , and platelets. Cultured skin fibroblasts and phytohemagglutinin-stimulated lymphocytes were karyotypically normal, but two independent abnormalities were found in marrow--47,XX, +8 and 46,XX,del(11)(q23). None of 14 type B G6PD lymphoblastoid lines analyzed in detail contained these karyotypic abnormalities, which strongly suggests that a visible chromosomal alteration is not the sole step in the development of this disease. We hypothesize that at least two events are involved in the pathogenesis of this patient's myelodysplasia: one causing proliferation of a clone of genetically unstable pluripotent stem cells and another inducing chromosomal abnormalities in its descendants.

Bone Marrow Cells↗
PubMed1979

A study of the relationship between family interaction and individual symptomology over time.

The study was designed to answer two questions: (a) Can a relationship over time between family interaction and individual symptomatology be demonstrated? (B) Can it be shown that changes in interaction have more influence on changes in the symptom than vice versa. Five interaction dimensions were taped in weekly, three-quarter hour sessions over 20 weeks in five families, each consisting of a mother-father-child triad who met certain criteria and had an encopretic child. The interaction dimension scores were abstracted weekly from these sessions by content analyses relying on various scales. The derived ratio scores were then related to the number of days the child soiled himself in the week preceding and following the interaction measurement. The relationship was assessed by Pearson correlation coefficients and step-wise multiple regression analyses adjusted to account for the possible inflationary effects of taking measures from the same subjects more than once. The results of the analyses answered both questions posed by the study in the affirmative, thus supporting the rationale underlying family therapy.

Family↗
PubMed1978

Histiocytosis and a leukaemoid response. A case report.

A patient with all the clinical signs of Letterer-Siwe disease is reported. The patient was unusual in that he had a severe leukaemoid reaction. To our knowledge, only 2 similar patients with reticulo-endotheliosis, histiocytic skin infiltration and leukaemoid reaction have been reported. It is possible that the disorder may represent a variant of the histiocytic proliferative disorders, characterized by both histiocytic and myeloid hyperplasia, and is thus similar to myelomonocytic leukaemia. However, it differs from the latter condition in that there is proliferation of monocytes and granulocytes in soft tissues rather than in the blood.

Blood Cell Count↗
PubMed1978

Hb Potomac (101 Glu replaced by Asp): speculations on placental oxygen transport in carriers of high-affinity hemoglobins.

Blood from a woman with unexplained erythrocytosis had increased oxygen affinity, but no abnormality could be detected by electrophoresis or chromatography of her hemolysate. Separation of the tryptic peptides of her beta chains disclosed two half-sized peaks in the regions of beta T-11. The faster of these was abnormal, with the structure beta 101 Glu replaced by Asp. The new hemoglobin was called "Potomac." Three of the proband's four surviving siblings and both of her children were carriers. Differences in the ratio of carrier: normal children born to male of female carriers of 23 other high-affinity hemoglobins were not significant. The high proportion of carriers in this kindred was probably due to chance alone, and not because high maternal oxygen affinity interfered with oxygen transport to fetuses with normal hemoglobin.

Adult↗
PubMed1976

Chronic myeloid leukaemia in South African blacks.

A study on 25 South African Black patients with chronic myelogenous leukaemia (CML), who were followed for 3 1/2 years, is reported. The Ph chromosome was found in 19 of 20 patients studied. Males predominated in a ratio of 2,5:1. Several unusual clinical features were encountered: significant lymphadenopathy, congestive cardiac failure and skin lesions. Patients with lymphadenopathy responded to busulphan therapy no differently from patients without lymphadenopathy. Nine patients had congestive cardiac failure, and in 7 of these a cause could not be found. Three untreated patients became pregnant, indicating that CML per se does not cause infertility. The haematological measurements were similar to those of previous reports; however, the marked splenomegaly suggests that South African Black patients present themselves for treatment rather late in the disease. The median survival time of 34 months is similar to that of previous reports of larger series from other parts of the world.

Adult↗
PubMed1976

In vitro reversal of cellular unresponsiveness induced by levamisole.

Mononuclear cells from twenty-one patients with depressed cellular reactivity were assessed for the ability to produce leucocyte inhibitory factor (LIF) and to transform after PHA stimulation, in the presence or absence of levamisole. Cells from nineteen patients failed to produce significant lymphokines when stimulated with PHA alone, but after a prior 1-hr levamisole pulse normal amounts of LIF were produced. Unstimulated mononuclear cell supernatants from six patients showed LIF-like activity, which could be abolished or decreased in five of the six when the cells were initially treated with levamisole. Mononuclear cells from seven of twelve patients which failed to incorporate [3H]thymidine after PHA activation, showed an increased response after a 1-hr levamisole pulse. Unstimulated mononuclear supernatants from six patients inhibited the lymphoproliferative response of normal cells to PHA. After treatment with levamisole, however, the suppressive effect of these supernatants was decreased or abolished. In vitro levamisole treatment, therefore, not only restores cellular responsiveness in anergic patients but also restricts the uncontrolled release of inhibitory factors.

Cells, Cultured↗