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Biomedical subjects

L Jensen

Publications and source records attributed to L Jensen.

At least 109 records · Page 6Linked to original sources
PubMed1993

Short-term liquid marrow cultures are supported by a mixture of haematopoietic cytokines but do not purge for acute myeloid or lymphoid leukemic marrow cells.

Short-term liquid marrow culture (STLMC) is a potential source for autografting in leukemia. In a preclinical setting, including candidates for autologous marrow transplantation, we have studied STLMC supported by a selected mixture of clinical available recombinant human haematopoietic growth factors. STLMC of leukemic marrow cells were prospectively performed to evaluate the purging effect. Bone marrow cells cultured and supported by the selected mixture of rhIL-3/rhGM-CSF/rhEpo revealed an increased number of day 10-12 cultured cells, parallelled by an increased proliferation rate when compared to unstimulated cultures. The median number of myeloid progenitors recognized as day 7 and day 14 granulocyte-macrophage colony-forming units (day 7/14 GM-CFU) was significantly increased in the supported STLMC to 145/305 from 105/115 per ml culture (n = 7, p < 0.01). Further addition of rhKL did not enhance the numbers of day 7 or day 14 GM-CFUs per ml culture. In no instance was the number of clonogenic cells at the end of culture greater than the input day 0, except in cultures of purified CD34-positive marrow progenitors which resulted in an expansion of late myeloid progenitors. Cytokine-supported cultures of leukemic marrow cells from acute myeloid (n = 14) and lymphoblastic (n = 7) leukemia patients were established at the time of diagnosis. In the supported cultures, the cell number increased for myeloblast but was unchanged for lymphoblast leukemic marrow cells compared to non-supported cultures. Immunophenotypic and cytogenetic studies of selected leukemic cell samples identified unchanged myeloid or slightly reduced frequencies of lymphoblastic leukemic cells at the end of culture. This preclinical study supports the idea that the addition of a mixture of clinical available haemopoietic cytokines to STLMC increases the recovery of detectable myeloid progenitors which may enhance myeloid regeneration after autografting. No substantial selective loss of myeloid leukemic cells was found in the cytokine-supported short-term culture system.

Bone Marrow↗
PubMed1993

Rebox: an adjunct in physical medicine?

Electrical therapy is used extensively in the treatment of musculoskeletal diseases. The best known form is transcutaneous electrical nerve stimulation (TENS). Rebox is another apparatus for electrical therapy that operates on much lower currents than TENS (0 to 300 microA). The effect of Rebox was tested on chronic lateral epicondylitis in 16 patients in a controlled crossover study. We found a significant effect of Rebox compared to placebo in respect to all the subjective and the objective variables: grip-strength, pain at power-grip and lifting a weightload with pronated forearm, and daily impairment.

Adult↗
PubMed1992

A study of donor alloreactivity, which may predict acute graft-versus-host disease in HLA identical bone marrow transplantations for early leukaemia.

Recent studies performed in Seattle, USA have suggested that pretransplant assignment of high or low donor alloreactivity may predict acute graft-versus-host disease (aGvHD) after allogeneic HLA identical marrow transplantation for acute leukaemia. The effect of such pretransplant assignment was studied in a Scandinavian population of 114 consecutive transplantations for acute and chronic leukaemias in 1st remission (n = 74) or chronic phase (n = 40) performed between 1975 and 1989. The selected cut-off value for discriminating between donors of high and low responding capacity (DRC) was based on distribution plots of results from the pretransplant mixed lymphocyte culture (MLC) and chosen as the median value (80% normalized response). Then 57 donors were assigned with high DRC and 57 donors assigned with low DRC. Kaplan-Meier estimates of the probability of patients to develop Grade II or higher aGvHD in receipt of high or low responder donor transplants were compared by univariant analysis. The patients in first remission or chronic phase transplanted with bone marrow from donors assigned as high or low responders had a 36.1% and 10.6% risk for aGvHD, respectively, a difference found to be significant by log rank test (chi-squared = 10.1, d.f. = 1, P = 0.0015). Subsequent studies of the cellular and humoral requirements for this predictive response of donor cells, by blocking with cytokine specific antibodies, addition of excess of recombinant human cytokines and scanning of lymphocyte subsets during the response, showed that the response against pool cells mostly depended upon IL-2 responding cells with the phenotype CD3+, CD4+, CD8-, CD25+, CD16-. It is concluded that prospective studies of alloreactivity as a risk factor should be performed to confirm the above findings.

Bone Marrow Transplantation↗
PubMed1992

Increased yield of myeloid progenitor cells in bone marrow harvested for autologous transplantation by pretreatment with recombinant human granulocyte-colony stimulating factor.

Pretreatment with haemopoietic cytokines prior to marrow harvest may result in improved quality of bone marrow harvested for autologous bone marrow transplantation (BMT). Such improvements may reduce the risk for graft failure and decrease time to engraftment. Patients undergoing autologous BMT received recombinant human G-CSF (rhG-CSF) immediately prior to marrow harvest. rhG-CSF was administered as daily subcutaneous injections for 5 days at 5 micrograms/kg body weight. Comparison of bone marrow samples before and after rhG-CSF treatment showed an increased bone marrow cellularity and a ninefold increase in the number of marrow leucocytes per volume aspirated. The mean marrow myeloid:erythroid ratio increased from 2.6 to 4.0. The mean numbers of immature (CD38 positive) and proliferating (CD71 positive) myeloid cells increased significantly from 41.6 to 50.8% and from 17.0 to 34.8%, respectively. Other subsets studied, including CD34 positive stem cells, were unchanged. The relative numbers of day 7 and 14 granulocyte-macrophage colony-forming units (day 7/14 GM-CFU) were unchanged. Long-term marrow cultures revealed that the numbers of 'long-term culture initiating cells' were unchanged after rhG-CSF treatment in spite of the ninefold increase in cellularity. To date, five of the patients have been transplanted with autologous marrow harvested after rhG-CSF treatment. Time to trilineage engraftment was unchanged compared with historical controls. We conclude that pretreatment with rhG-CSF prior to marrow harvest may improve the graft by increasing the total number of myeloid lineage restricted progenitor cells, resulting in stable but not accelerated myeloid engraftment of autologous marrow.

Bone Marrow Transplantation↗
PubMed1992

Student evaluation of sex education programs advocating abstinence.

This research examined the attitudes of students who were enrolled in three different sex education programs that emphasize abstinence. Data were examined to determine whether secondary school students responded positively to the programs. The programs examined were Values and Choices, Teen Aid, and Sex Respect. Results of the study indicated that all three programs were rated positively, with female, younger (junior high school age), and virgin-naive students rating the programs more highly.

Adolescent↗
PubMed1991

Incontinence and rectal prolapse: a prospective manometric study.

A prospective, manometric study has been performed on 23 female patients with rectal prolapse and varying degrees of incontinence. Seven of the 14 incontinent patients regained continence after surgery, and a further two patients improved. Improvement in internal and external sphincter function follows correction of rectal prolapse. Preoperative resting anal pressure was significantly higher in continent patients than in incontinent patients (P less than 0.05), as was the maximum voluntary contraction pressure (P less than 0.027). Postoperatively there was a significant increase in the resting anal pressure (P less than 0.0001) and maximum voluntary contraction pressure (P less than 0.003) in the whole group. The preoperative resting anorectal angle was significantly more acute (P less than 0.028) in continent patients than in incontinent patients. There was no significant change in the resting anorectal angle following prolapse repair. Patients who remained incontinent had a significantly lower preoperative resting anal pressure (P less than 0.01) than patients who improved or regained continence. Similarly, maximum voluntary contraction pressure was lower preoperatively in these patients (P less than 0.02). Preoperative resting anal pressure below 10 mm Hg and maximum voluntary contraction pressure below 50 mm Hg are associated with persisting incontinence after surgery.

Adult↗
PubMed1991

Development of a self-theory and measurement scale.

In this study, we examined a theoretical model of self-development and a scale to measure 12 aspects of the self. The theory, called developmental self-theory, proposes a hierarchical arrangement of dimensions of the self. The 12 scales are collectively called the Omnibus Self-Test and measure Self-Esteem, Positive Self-Regard, Moral Self-Concept, Self-Confidence, Self-Reliance, Self-Control, Selfishness, Self-Disclosure, Self-as-Agent, Self-Critical, Self-Identity, and Self-Reflection. Preliminary data on the reliability and validity of the Omnibus Self-Test is reported along with intercorrelations among the scales.

Adult↗
PubMed1991

Secondary earner strategies and family poverty: immigrant-native differentials, 1960-1980.

"This article studies immigrant-native differentials in the ability of secondary earners (family earners other than the family head) to lift families out of poverty. Using both descriptive and multivariate techniques to analyze the 1960, 1970 and 1980 U.S. Census Public Use Samples, it compares immigrant and native families among four key race groups: white, black, Hispanic and Asian. It is shown that the ameliorative impact of secondary earners is greater for immigrant than native families; that this generalization holds for whites, blacks and Hispanics but not Asians; and that the immigrant advantage in ameliorative effects vis-a-vis natives declined noticeably over the 1960-1980 period for all but Asian families. The implications of these results for the overall trend in poverty among immigrants is discussed."

Black or African American↗
PubMed1990

Guidelines for the application of ARIMA models in time series.

Time series analysis has been suggested as a valuable approach to evaluating the effectiveness of nursing interventions. Time series analysis techniques provide the tools for analyzing unique behavioral fluctuations through time and a framework for predicting future changes in the individual. Because of its newness, time series modeling has not been used widely in nursing research, but it can provide information about processes in nursing practice. Despite the utility of the interrupted time series design, a number of problems frequently arise in view of the practical and inferential difficulties in conducting interrupted time series research. The inherent limitations of time series analysis procedures are discussed in application to research problems.

Humans↗
PubMed1990

Atrial natriuretic factor, cyclic 3',5'-guanosine monophosphate and prostaglandin E2 in liver cirrhosis: relation to blood volume and changes in blood volume after furosemide.

Plasma concentrations of atrial natriuretic factor (ANF) and cyclic 3',5'-guanosine monophosphate (cGMP) were measured in 11 cirrhotic patients with ascites, 11 cirrhotic patients without ascites and 15 control subjects. The following were determined in 15 of the cirrhotic patients and in all the control subjects: blood volume (BV) and furosemide-induced changes in BV, plasma values of ANF, cGMP, angiotensin II (AII), aldosterone (Aldo), arginine vasopressin (AVP) and urinary excretion rates of cGMP, prostaglandin E2 (PGE2), water and sodium. Basal plasma levels of ANF and cGMP were higher in patients with cirrhosis than in controls, but were the same in both groups of cirrhotics (ANF: cirrhosis with ascites 12.7, without ascites 13.4, and in controls 5.8 pmol l-1 (medians); cGMP: 7.7, 7.4 and 4.3 nmol l-1, respectively). BV was less reduced after furosemide in the cirrhotic patients (6.0%) than in the healthy subjects (10.1%), but basal BV did not differ. Urinary sodium excretion rates after furosemide were significantly lower in the cirrhotic patients than in the controls. PGE2 excretion rate increased after furosemide in the cirrhotic patients (0.29 to 0.66 pmol min-1; P less than 0.01) but not in the controls (0.31 to 0.38 pmol min-1). After furosemide ANF and cGMP decreased slightly in both groups whereas AII and Aldo increased; AVP increased in the controls, but not in the cirrhotic patients. In conclusion, plasma values of ANF and cGMP are increased in liver cirrhosis both with and without ascites. This and the elevated PGE2 excretion after furosemide may be compensatory phenomena in order to facilitate renal sodium excretion.

Adult↗
PubMed1990

Association of country, sex, social class, and life cycle to locus of control in western European countries.

Relatively few studies have focused on causal factors in the development of locus of control. Here nine western European countries are studied to assess the hypothesis that the society in which one lives is important in the scores on locus of control. The data indicate greater variation resulting from country of residence on locus of control than that from the variables of life cycle, sex, and social class. Findings regarding these latter variables are congruent with previous research. In addition, being single was related to having an external locus of control.

Adolescent↗
PubMed1989

Proliferative and synthetic response of bovine growth plate chondrocytes to various capacitively coupled electrical fields.

In vitro monolayer cultures of growth plate chondrocytes isolated from newborn calf costochondral junctions were subjected to capacitively coupled electrical fields for 48 h. In part A, the electrical signal was a 60-kHz sine wave applied at different voltages so as to produce electrical fields at the pericellular level of 7, 20, 50, and 126 mV/cm. Incorporations of [3H]thymidine and [35S]sulfate were assayed to determine the effect of the above fields on cells proliferation and matrix synthesis, respectively. Proliferation was increased by 47% in the 20 mV/cm field whereas the same field decreased [35S]sulfate incorporation by 21%. These changes were significant at p less than 0.05 in both instances. In part B, the 20 mV/cm field was applied in a pulsed fashion to produce daily duty cycles of 100, 25, 2, and 0.25%. Incorporation of [3H]thymidine, [35S]sulfate, and [14C]proline per DNA were assayed. Results indicated that the 100, 25, and 0.25% percent duty cycles showed significantly (p less than 0.01-0.05) increased proliferation, whereas the 0.25% signal (5 ms on/495 ms off for 6 h/day) significantly decreased [14C]proline incorporation. We conclude that the biologic response of cells in vitro is signal specific, and that the total amount of electrical energy required to stimulate the growth plate chondrocyte to increased proliferation is very small since the total time the 0.25% duty cycle signal was only 3.6 min of a 24-h period.

Animals↗