301
|
Abstract
To study porphyrin biosynthesis in normal human keratinocytes and A431 cells derived from human epidermoid carcinoma, cultured cells were incubated with delta-aminolevulinic acid (ALA), the precursor of porphyrin synthesis, and accumulation of porphyrins was measured spectrofluorometrically. Both human keratinocytes and A431 cells accumulated porphyrins in a time-dependent and a dose-dependent fashion. Protoporphyrin was the predominant porphyrin accumulated by both cell types. Porphyrin accumulation was enhanced by Ca Mg ethylenediaminetetraacetic acid, a ferrochelatase inhibitor, and the enhancement was reversed by the addition of iron, suggesting the utilization of iron by ferrochelatase. The effect of light on porphyrin accumulation was evaluated by exposing the ALA-loaded A431 cells to ultraviolet-A (UVA) and blue light radiation, followed by continued incubation with ALA for 2-48 h. There was an enhancement of porphyrin accumulation 2-48 h after the radiation as compared with nonirradiated controls. Consistent with this finding, ferrochelatase activity decreased in these cells at 24 h and 48 h. These data demonstrate that human keratinocytes and A431 cells are capable of porphyrin biosynthesis, and that exposure of porphyrin-containing A431 cells to light, which includes the Soret band spectrum, decreases the ferrochelatase activity, which is responsible, at least in part, for the further increase in porphyrin level.
Collapse
Affiliation(s)
- D He
- Dermatology Service, Department of Veterans Affairs Medical Center, New York, NY 10010
| | | | | |
Collapse
|
302
|
Abstract
Incubation of murine epidermal cells with delta-aminolevulinic acid (ALA) resulted in a dose- and time-dependent accumulation of porphyrins, predominantly of protoporphyrin. Porphyrin accumulation decreased in the presence of iron, and the iron-mediated decrease was partially reversed by CaMg EDTA (1.25-10.0 mM), suggesting that there is functionally active ferrochelatase in these cells. This study suggests that these cells may be a useful model for the study of cutaneous porphyrin metabolism involving ferrochelatase activity.
Collapse
Affiliation(s)
- D He
- Dermatology Service, Department of Veterans Affairs Medical Center, New York, NY 10010
| | | | | | | |
Collapse
|
303
|
Abstract
We have used an anhepatic dog model to demonstrate the efficacy of a bioartificial liver assist device. Six dogs underwent total hepatectomy. Three received only medical care (controls) while the remainder were connected to an extracorporeal liver assist device (ELAD). The control dogs failed to regain consciousness after anesthesia although all lived 4-5 h postoperatively. Plasma ammonia concentration increased by an average of 250 mumol/L between the end of surgery and the demise of the animals. The treated dogs lived 3-12.5 h, and 2 of them required repeated doses of thiamylal sodium to maintain sedation. Plasma ammonia concentration was unchanged after connection to the ELAD except in the longest survivor, whose ammonia began to rise after 8 h on the ELAD. The short survival in the other 2 treated dogs was the result of uncontrolled intraabdominal bleeding. This device is capable of replacing the metabolic function of the liver, and might provide hepatic support in patients awaiting transplantation or in fulminant hepatic failure.
Collapse
Affiliation(s)
- J H Kelly
- Department of Pathology, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | | | | | | | | | |
Collapse
|
304
|
Wang X, Xie W, Long Q, He D, Lin G, Pang Y, Pu Z. Stimulation of thymidine kinase activity in baculovirus infected cells is not due to a virus-coded enzyme. Arch Virol 1992; 127:315-9. [PMID: 1333755 DOI: 10.1007/bf01309593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A polyhedrin-positive recombinant autographa californica nuclear polyhedrosis virus (AcNPV) carrying a herpes simplex virus thymidine kinase gene under the control of the SynXIV promoter, a fusion of synthetic and linker-modified polyhedrin promoters, has been constructed. When this recombinant baculovirus was used to infect a variant of Spodoptera frugiperda cells deficient in thymidine kinase (TK-), a high level of TK activity was detected. These results, in conjunction with the demonstration that AcNPV could replicate in TK- S. frugiperda cells and no TK activity was found throughout infection, imply that the wild type virus-stimulated TK activity observed in S. frugiperda (TK+) cells is not contributed by a virus-coded enzyme.
Collapse
Affiliation(s)
- X Wang
- Institute of Entomology, Zhongshan University, Guangzhou, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
305
|
Abstract
This study investigated the effect of radiation on clinical and histologic changes, and on cutaneous eicosanoid metabolism, in Skh:HR-1 hairless albino mice rendered protoporphyric by the administration of collidine. At 0.1-18 h after exposure to 12 kJ/m2 of 396-406 nm irradiation, thicknesses of back skin and ears were measured, and histologic changes were evaluated by using hematoxylin and eosin (H-E) and Giemsa's stains. Activities of eicosanoid-metabolizing enzymes in epidermal and dermal homogenates were assessed by incubating the tissue homogenates with 3H-AA, followed by quantitation of the eicosanoids generated by radio-TLC. In irradiated protoporphyric mice, an increase of back-skin thickness was noted at 0.1 h, reaching a peak at 18 h, whereas maximal increase in ear thickness was observed at 12 h. Histologic changes included dermal edema, increased mast cell degranulation, and mononuclear cells in the dermis. In these irradiated protoporphyric animals, generations of 6 keto-PGF1a, PGF2a, PGE2, PGD2, and HETE by epidermal eicosanoid-metabolizing enzymes were markedly suppressed at all the timepoints studied. Dermal eicosanoid-metabolizing enzymes of irradiated protoporphyric mice generated increased amounts of PGE2 and HETE at 18 h, probably reflecting the presence of dermal cellular infiltrates. The suppression of the activities of epidermal eicosanoid-metabolizing enzymes was prevented by intraperitoneal injection of WR-2721, a sulfhydryl group generator, prior to irradiation, suggesting that the suppression was secondary to photo-oxidative damage of the enzymes during the in vivo phototoxic response. These results suggest that the effect of protoporphyrin and radiation on cutaneous eicosanoid metabolism in this animal model in vivo is that of a down regulation of the activities of epidermal eicosanoid-metabolizing enzymes.
Collapse
Affiliation(s)
- D He
- Department of Veterans Affairs Medical Center, New York, NY 10010
| | | |
Collapse
|
306
|
Abstract
To evaluate further the interactions of C5a and mast cells in cutaneous inflammation, the ability of human native C5a (nC5a) (10 to 500 ng/ml) and human recombinant C5a (rC5a) (10 ng/ml to 100 ng/ml) to induce histamine release from purified BALB/c cutaneous mast cells (CMC) and peritoneal mast cells (PMC) was analyzed. It was found that nC5a induced histamine release from CMC but not from PMC, with a maximal net release at 250 ng/ml nC5a (22.8 +/- 2.6%). Kinetic experiments demonstrated that nC5a-induced maximal net histamine release occurred 5 min after the presentation of this stimulus (25.8 +/- 6.0%). Using rC5a and CMC, dose-response studies indicated a maximal net release of 7.0 +/- 1.7% at rC5a of 10 ng/ml, and kinetic studies showed a maximal net release at 5 min of incubation (12.9 +/- 1.6%). Release induced by rC5a was calcium-dependent, and peaked at 30 degrees C. These results indicate that functional heterogeneity exists between the CMC and the PMC of BALB/c mice, that C5a is a relevant stimulus for characterization of this heterogeneity, and that CMC from these animals can serve as a convenient in vitro model for the study of human C5a-mast cell interactions. In vivo, injections of nC5a (25-100 ng) and rC5a (25-100 ng) into the skin of BALB/c mice induced an increase in cutaneous vasopermeability, as assessed by the extravasation of intravenously injected 125I-bovine serum albumin. nC5a induced a dose-dependent increase in vasopermeability, whereas alterations induced by rC5a plateaued at 50 ng. The C5a-induced vasopermeability was markedly enhanced in animals that had been previously treated with an inhibitor of serum carboxypeptidase, which converts C5a to the less potent derivative, C5a des Arg. These findings suggest that carboxypeptidase plays an important role in vivo in the modulation of C5a-induced cutaneous inflammation in murine skin.
Collapse
Affiliation(s)
- H W Lim
- Dermatology Service, Department of Veterans Affairs Medical Center, New York, NY 10010
| | | | | | | | | |
Collapse
|
307
|
Spektor DM, Thurston GD, Mao J, He D, Hayes C, Lippmann M. Effects of single- and multiday ozone exposures on respiratory function in active normal children. Environ Res 1991; 55:107-22. [PMID: 1868814 DOI: 10.1016/s0013-9351(05)80167-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Ventilatory function was measured twice daily on 46 healthy children aged 8-14 years on at least 7 days for each child during a 4-week period at a northwestern New Jersey residential summer camp in 1988. The highest 1-hr O3 concentration was 150 ppb, while the highest 12-hr H+ concentration (as H2SO4) was 18.6 micrograms/m3. The highest temperature-humidity index was 81 degrees F. The regressions of FVC, FEV1, FEF25-75, and PEFR on O3 in the hour preceding the afternoon function measurements yielded slopes essentially the same as those measured on other children at the same camp in 1984. Regressions of the changes in function between the late morning and late afternoon function measurements on average O3 concentration between them produced significant, but somewhat smaller effects, while regressions of morning function on O3 during the previous day indicated small but still significant effects. There were no significant correlations with other measured environmental variables including H+. Based on the results of this study and similar previous studies, we conclude that O3 exposures in ambient air produce greater lung function deficits in active young people in natural settings then does pure O3 in controlled chamber exposure studies because of: (1) longer exposures; (2) potentiation by other factors in the ambient exposures; (3) the persistence of effects from prior day's exposures; and (4) the persistence of a transient response associated with the daily peak of exposure. It follows that projections of likely effects in the real world from controlled chamber exposure studies should either have a large margin of safety, or the judgment of the extent of effects likely to occur among populations should be based directly on the effects observed in field studies.
Collapse
Affiliation(s)
- D M Spektor
- Institute of Environmental Medicine, New York University Medical Center, Tuxedo 10987
| | | | | | | | | | | |
Collapse
|
308
|
He D. Small cities and towns in Liaoning Province: their development and classification. Chin J Popul Sci 1991; 3:137-43. [PMID: 12317651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
|
309
|
Abstract
To investigate the functional heterogeneity of mouse mast cells, we extracted and purified cutaneous and peritoneal mast cells from 10- to 18-week-old BALB/c mice and compared their responses to secretagogues. Cutaneous mast cells (CMC) were extracted from mouse ears after digestion with hyaluronidase and collagenase in MEM containing 25% fetal calf serum and purified on a discontinuous Percoll gradient. The histamine content of cells obtained from the 30/40% interface was 1.0 +/- 0.1 pg/cell (mean +/- SE), with a mast-cell purity of 68.6 +/- 4.4% and a viability of greater than 93%. Peritoneal mast cells (PMC) were obtained by lavage with modified Tyrode's buffer followed by purification on 22.5% and 3-9% metrizamide gradients. The histamine content of cells was 12.2 +/- 0.8 pg/cell, with a mast-cell purity of 95.9 +/- 0.6% and a viability of greater than 95%. Histamine release induced by A23187 from CMC peaked at 3.0 microM A23187 (19.1 +/- 4.2%), at 3.0 min (22.3 +/- 2.3%), and at 30 degrees C (17.6 +/- 2.6%). In contrast, histamine release from PMC peaked at 8.0 microM of A23187 (49.4 +/- 12.1%) and at 15.0 min (48.5 +/- 12.2%). Release of histamine from PMC was observed at all the temperatures tested from 22 to 45 degrees C. Histamine release from CMC and PMC induced by A23187 was calcium dependent. Histamine release induced by compound 48/80 from CMC peaked at 0.5 micrograms/ml of compound 48/80 (23.0 +/- 7.4%) and at 5.0 min incubation (16.3 +/- 2.0%), whereas release from PMC peaked at 10.0 micrograms/ml (31.9 +/- 2.6%); release from PMC was similar at all the time points examined (1-15 min). Histamine release induced by substance P (SP) from both CMC and PMC peaked at 5.0 microM (18.8 +/- 6.6% and 12.6 +/- 3.7%, respectively); however, the maximal release from CMC occurred at 3.0 min (18.2 +/- 3.2%) and from PMC at 30.0 min (11.4 +/- 2.0%). SP-induced histamine release from CMC was calcium dependent, whereas release from PMC was only partially inhibited by EDTA. This study demonstrated that functional heterogeneity exists between these two populations of mast cells.
Collapse
Affiliation(s)
- D He
- Dermatology Service, New York Veterans Administration Medical Center, New York 10010
| | | | | | | |
Collapse
|
310
|
Lu SJ, He D, Huang HL, Huang XY. [Enhancing effect of danggui injection on immunologic function]. Zhongguo Zhong Yao Za Zhi 1989; 14:685-7, 704. [PMID: 2695109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Experiments have shown that Danggui injection enhances phagocytic function of macrophage in normal mice, and antagonizes the immunosuppressive activity of macrophage by cytoxan. The injection may increase the function of B cells and the activity of serum lysozyme, thus increasing the function of humoral immunity and nonspecific immunity.
Collapse
|
311
|
Trybula Z, Schmidt VH, Drumheller JE, He D, Li Z. Dielectric measurements of the proton-glass state in Rb0.65(NH4)0.35H2AsO4. Phys Rev B Condens Matter 1989; 40:5289-5291. [PMID: 9992554 DOI: 10.1103/physrevb.40.5289] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
312
|
He D, Soter NA, Lim HW. The late phase of hematoporphyrin derivative-induced phototoxicity in mice: release of histamine and histologic changes. Photochem Photobiol 1989; 50:91-5. [PMID: 2474837 DOI: 10.1111/j.1751-1097.1989.tb04133.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This study was designed to directly examine the role of mast cells and the histologic changes in the late phase (4-48 h) of hematoporphyrin derivative-induced phototoxicity. BALB/c mice were rendered phototoxic by intraperitoneal injection of HpD, followed by exposure to 1.59 kJ/m2 of 396-406 nm radiation. Immediately before radiation, and at 4, 8, 12, 18, 24 and 48 h after radiation, the ear thickness, serum histamine levels and histologic changes of ears were examined. A maximal net increase in ear thickness of 33.5 +/- 0.3 X 10(-2) mm (mean +/- SE) was noted at 12 h, associated with a maximal net increase of serum histamine (43.3 +/- 11.6 ng/ml, mean +/- SE), and a maximal mast cell degranulation. Other histologic changes consisted of mild epidermal spongiosis at 18-24 h, and a predominant neutrophilic infiltrate, which peaked at 24 h (211.6 +/- 0.4 cells/mm2). No significant alteration was observed in control mice. These data indicated that mast cells participate in the late phase of HpD-induced phototoxicity in mice.
Collapse
|
313
|
Sarachik MP, Roy A, Turner M, Levy M, He D, Isaacs LL, Bhatt RN. Scaling behavior of the magnetization of insulating Si:P. Phys Rev B Condens Matter 1986; 34:387-390. [PMID: 9939273 DOI: 10.1103/physrevb.34.387] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
|
314
|
He D. [Testing of lung function during exercise in healthy adults]. Zhonghua Jie He He Hu Xi Xi Ji Bing Za Zhi 1984; 7:162-5, 192. [PMID: 6518931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|