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Biomedical subjects

L Lu

Publications and source records attributed to L Lu.

At least 613 records · Page 34Linked to original sources
PubMed1983

Cardiac hemochromatosis: beneficial effects of iron removal therapy. An echocardiographic study.

The echocardiographic (echo) features of idiopathic hemochromatosis (IH) were studied in 22 patients. Results were compared with a control group of 22 patients without heart disease. Statistically significant increases in left ventricular (LV) mass, end-diastolic and end-systolic diameters of the left ventricle and in left atrial dimension were observed in patients with IH; significant changes of systolic function indexes (decrease in fractional shortening and ejection fraction and increase in distance of the E point to the septum) were seen as well. These echo abnormalities were mainly seen in patients with abnormal electrocardiograms. In 11 patients with IH, iron removal therapy was carried out by means of periodic phlebotomies. In patients with impaired LV function at the beginning of therapy, comparison between measurements of the initial echo and posttreatment echo showed significant improvement in LV diameters, fractional shortening, ejection fraction, distance from the E point to the septum, LV mass and left atrial dimension.

Adult↗
PubMed1983

The primary hamster kidney cell rabies vaccine: adaptation of viral strain, production of vaccine, and pre- and postexposure treatment.

The hamster kidney cell rabies vaccine was investigated as a substitute for classical nervous tissue rabies vaccine. The Beijing strain of fixed rabies virus was adapted to primary hamster kidney cells (PHKCs), and four types of rabies vaccine (plain, adjuvant, concentrated, and concentrated adjuvant vaccines) were developed for human use. The potencies of the vaccines met the requirements of the World Health Organization, and these vaccines elicited rather satisfactory antibody responses in volunteers. The postexposure use of vaccine was evaluated in 301 individuals, 97 of whom had been bitten by proven rabid animals. None of the individuals contracted rabies during the observation period. After several years of field trials with both pre- and postexposure vaccines, the evidence indicates that the PHKC rabies vaccines are effective and safe for human use.

Animals↗
PubMed1983

Association of cell cycle expression of Ia-like antigenic determinations on normal human multipotential (CFU-GEMM) and erythroid (BFU-E) progenitor cells with regulation in vitro by acidic isoferritins.

An association has been established between human Ia-like antigenic determinants, expression during DNA synthesis on multipotential (CFU-GEMM) and erythroid (BFU-E) progenitor cells, and the regulatory action of acidic isoferritins in vitro. Treatment of human bone marrow cells with monoclonal anti-Ia (NE1-011) plus complement inhibited colony formation of CFU-GEMM) and BFU-E by 50%-70%. Reduction of colonies was similar whether bone marrow cells were exposed to anti-Ia plus complement, high specific tritiated thymidine (3HTdr), or acidic isoferritins. No further decrease was apparent with 3HTdr or acidic isoferritins after Ia-antigen+ CFU-GEMM or BFU-E were removed, or with anti-Ia plus complement or acidic isoferritins after S-phase CFU-GEMM or BFU-E were removed. Anti-Ia, in the absence of complement, had no effect on colony formation but blocked the inhibition of CFU-GEMM and BFU-E by acidic isoferritins. Demonstration of Ia-antigens on BFU-E and inhibition of BFU-E by acidic isoferritins appeared to require the presence of phytohemmagglutinin leukocyte conditioned medium (PHA-LCM) in the culture medium during the 14-day incubation period. these results implicate Ia-antigen+ cells, acidic isoferritins, and PHA-LCM in the regulation of multipotential and erythroid progenitor cells in vitro.

Antibodies, Monoclonal↗
PubMed1983

Comparative analysis of the influences of human gamma, alpha and beta interferons on human multipotential (CFU-GEMM), erythroid (BFU-E) and granulocyte-macrophage (CFU-GM) progenitor cells.

Preparations of human interferon (HuIFN) immune (gamma) (2 X 10(7) units/mg protein), HuIFN leukocyte (alpha) (1.4 X 10(8) units/mg protein) and HuIFN fibroblasts (beta) (10(6) U/mg protein) were assessed for their influence on colony formation of human hematopoietic progenitor cells: colony forming unit-granulocyte, erythroid, macrophage, megakaryocyte (CFU-GEMM), burst forming unit-erythroid (BFU-E), day 7 colony forming unit granulocyte-macrophage (CFU-GM) and day 14 CFU-GM. Colony formation by CFU-GEMM and BFU-E was suppressed equally by the three preparations of HuIFN, but colony formation by CFU-GM was suppressed differentially. CFU-GM were, on the whole, more responsive to HuIFN gamma than HuIFN alpha, and HuIFN beta was least effective. HuIFN alpha, but not HuIFN gamma or HuIFN beta, suppressed colony formation from CFU-GM without also suppressing the total number of colonies plus clusters. This was due to an increase in the numbers of clusters formed in the presence of HuIFN alpha. The suppressive influence on colonies from CFU-GM by the preparations of HuIFN and the enhancement of clusters by HuIFN alpha was apparently equal for colonies and clusters of neutrophils, eosinophils, macrophages and neutrophils plus macrophages. The suppressive effects of HuIFN gamma were inactivated by a monoclonal antibody to HuIFN gamma and the suppressive and enhancing effects of HuIFN alpha were inactivated with a heteroantiserum to HuIFN alpha. Depletion of monocytes, T lymphocytes and B lymphocytes from the target bone marrow cells had no influence on the effects of the preparations of HuIFN. These results demonstrate that the effects of HuIFN gamma and HuIFN alpha are due to the HuIFN themselves and that these actions on the hematopoietic progenitor cells are probably not mediated through monocytes and/or lymphocytes.

Antibodies, Monoclonal↗
PubMed1983

Transferrin, derived from an OKT8-positive subpopulation of T lymphocytes, suppresses the production of granulocyte-macrophage colony-stimulatory factors from mitogen-activated T lymphocytes.

Purified human transferrin, when saturated with iron or zinc, decreased the production of granulocyte-macrophage colony-stimulating factors (GM-CSF) by human T lymphocytes that had been stimulated by phytohemagglutin or concanavalin-A. The iron-saturated transferrin was more active than the zinc-saturated transferrin. This effect was not seen for copper-saturated transferrin or for apotransferrin, and the inhibitory effect was seen whether production of GM-CSF occurred in the absence or presence of serum. If the lymphocytes were pretreated with monoclonal antibody against transferrin receptors, no suppressive effect with transferrin was seen. Transferrin did not have a direct effect on the granulocyte-macrophage colony or cluster-forming cells (CFU-GM) or on preformed GM-CSF. Transferrin-inhibitory activity was produced and released only from a subpopulation of T lymphocytes that had the OKT8+ antigenic phenotype. Release of this activity from OKT8+ lymphocytes, into culture medium at 37 degrees C, was first detected after 6-17 hr, but the capacity of the GM-CSF-producing lymphocytes to respond to transferrin-inhibitory activity was apparent only within the first 3 hr of placing the lymphocytes at 37 degrees C. These studies demonstrate feedback interactions confined to cells of the T-lymphocyte lineage that may be of relevance to the regulation of myelopoiesis.

Antibodies, Monoclonal↗
PubMed1983

The selective enhancing influence of hemin and products of human erythrocytes on colony formation by human multipotential (CFUGEMM) and erythroid (BFUE) progenitor cells in vitro.

The influence of erythrocytes, extracts of erythrocytes and hemin was assessed on colony formation in vitro by human bone marrow multipotential (CFUGEMM), erythroid (BFUE) and granulocyte-macrophage (CFUGM) progenitor cells. Colony formation by CFUGEMM and BFUE present in the low density (less than 1.077 g/cm3) fraction of bone marrow cells was enhanced in the presence of high density (greater than 1.077 g/cm3) bone marrow cells. Erythrocytes, but not leukocytes, present in the high density fraction of cells were responsible for this enhancing effect on colony formation. Extracts of erythrocytes or hemin substituted for the enhancing activity of the intact erythrocytes. This enhancing activity was not apparent on colony formation by bone marrow CFUGM. These results demonstrate a selective enhancing influence on colonies derived from CFUGEMM and BFUE. Erythrocyte products allow the detection of such colonies and may play a role in the growth stimulation of CFUGEMM and BFUE.

Bone Marrow Cells↗
PubMed1982

Acute myeloid leukemia as the first hematologic manifestation of Fanconi anemia.

A six-year-old girl with Fanconi anemia (FA) developed acute myeloid leukemia (AML) as the first hematologic manifestation of the syndrome. She remains in remission 18 mo after diagnosis although her management is complicated by unusual sensitivity to chemotherapeutic agents. Marrow cells studied prior to initiation of leukemia therapy showed increased chromosome breakage and an abnormal clone in which a number 7 and a number 8 chromosome were replaced by two marker chromosomes. During the present remission her cultured lymphocytes, bone marrow cells, and fibroblasts showed increased "spontaneous" chromosome breakage as well as enhanced sensitivity to the clastogenic effect of the difunctional alkylating agent diepoxybutane (DEB), features characteristic of FA. Eight months into remission 50% of her marrow cells comprised an abnormal clone, which was monosomic for the number 7 chromosome but had both copies of number 8; in addition a variable number of unique marker chromosomes were present in clonal as well as nonclonal cells. This same marrow sample, upon culture, showed an abnormal growth pattern of CFU-GM, absence of detectable CFU-GEMM and BFUe, non-responsiveness of CFU-GM to inhibition by acidic isoferritins, increased bone marrow acidic isoferritin inhibitory activity, and absence of detectable bone marrow cell-derived GM-CSF. The implications of these findings to leukemogenesis in FA are discussed.

Anemia, Aplastic↗
PubMed1982

Monocyte-macrophage-derived acidic isoferritins: normal feedback regulators of granulocyte-macrophage progenitor cells in vitro.

The recent identification of a leukemia-associated inhibitory activity (LIA) against granulocyte-macrophage progenitor cells (CFU-GM) as acidic isoferritins has now led to detection of this activity in normal bone marrow and blood cells. Detection of this activity depends on stimulation of CFU-GM by granulocyte-macrophage colony stimulatory factors (GM-CSF), and some conditioned media (CM) sources of GM-CSF (human placental and monocyte, mouse macrophage and WEHI-3) contained low levels of acidic isoferritin that lowered colony formation. Inactivation or removal of this activity increased the stimulatory capacity of the CM. CM depleted of acidic isoferritins or CM originally devoid of this activity (human GCT, 5637, Mo, lymphocytes: mouse L cells or pokeweed-mitogen-stimulated spleen cells) increased the sensitivity of the assay to detect acidic isoferritin inhibitory activity. This activity was selectively contained and released from normal monocytes and macrophages. Restriction of this activity to mononuclear phagocytes was substantiated, as only continuous cell lines of monocytes and macrophages or lines capable of induction to this lineage contained and released acidic isoferritin inhibitory activity. The cells of origin and target cells of action suggest that acidic isoferritin-inhibitory activity can be considered as a negative feedback regulator, at least in vitro.

Animals↗
PubMed1981

Detection of luxol-fast-blue positive cells in human promyelocytic leukemia cell line HL-60.

Differentiation of HL-60 cells toward the eosinophilic series has not been reported previously. Eosinophil granule specific staining with Luxol-fast-blue was used to determine if HL-60 cells could differentiate into the eosinophilic lineage. The specificity of the Luxol-fast-blue stain for cells of the eosinophilic series was substantiated by comparison of the staining of cells from a patient with an eosinophilic syndrome by Wright-Giemsa and Luxol-fast-blue. Luxol-fast-blue positivity was most notable in cells found in colonies formed from HL-60 clonogenic cells in semisolid agar medium. Colony and cluster formation was spontaneous but in the presence of medium conditioned by either human placental cells or the human monocyte-like cell line, GCT, Luxol-fast-blue positive colonies and clusters were detected at a higher frequency.

Cell Line↗
PubMed1980

Familial lymphoid interstitial pneumonia: a long-term follow-up.

We describe two brothers who developed chronic pulmonary disease in early childhood. Lung biopsies were diagnostic of lymphoid interstitial pneumonia (LIP). Familial LIP has not been previously reported, and the natural history is unknown. The elder brother experienced progressive respiratory disability and died 10 years after the onset of symptoms. The younger brother age 13, has been observed for 11 years and despite progression of pathological changes revealed in his second lung biopsy, he has had few symptoms and leads an active life. Current pulmonary function tests reveal decreased lung volumes, increased maximal expiratory flow rates and decreased lung compliance. Arterial PO2 is 75 mm Hg at rest and falls to 56 mm Hg with exercise. These findings, consistent with restrictive lung disease, contrast with the obstructive ventilatory pattern seen in some adult patients.

Child, Preschool↗
PubMedDate not supplied

Production of human B and T cell growth factors is enhanced by thymic hormones.

The thymic preparations thymosin fraction 5 (TF5) and synthetic thymosin alpha 1 (T alpha 1) were examined for their ability to enhance growth factor production by human peripheral blood mononuclear cells (PBMC). The results showed that both TF5 and T alpha 1 were capable of enhancing the production of a B cell growth factor (BCGF-12kD) and T cell growth factor (TCGF; IL-2). Enhancement by T alpha 1 could be obtained at 100-200-fold lower concentrations than that seen with TF5. In contrast, no enhancement of growth factor production was obtained with control preparations of non-thymic tissue extracts at any concentrations used. It was observed that stimulation of BCGF-12kD and IL-2 was most significantly obtained when the PBMC were activated with lectin. Furthermore, no direct effect of thymic hormones on test B and T cells was observed. These observations provide the first direct evidence that production of B cell growth factors can be enhanced by thymic hormones. In addition, these studies suggest that thymic hormones may regulate B cell responses by acting on mature activated T lymphocytes.

B-Lymphocytes↗