Merocyanine 540 mediated photolysis of normal bone marrow, committed hemopoietic progenitors and neoplastic cells. implications for bone marrow purging

The effect of merocyanine 540 (Mc 540) mediated photoirradiation on both neoplastic and normal hemopoietic progenitor cells was studied. Bone marrow (BM) cells from children with acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML) at initial diagnosis, ALL in remission, neuroblastoma and normal children as well as cells of Reh-6 and HL-60 cell lines were incubated with Mc 540 in the presence of human albumin (HA) and exposed to different argon laser 514 nm doses. Cell survival was estimated using Trypan Blue supravital stain following a 24-h incubation and leukemic cell lines were studied in continuous cell cultures of 4 weeks duration. Our results showed that HA protects normal BM cells from Mc 540 mediated phototoxicity. A 99.9999% inhibition of Reh-6 and HL-60 was noted at irradiation doses where the corresponding mean survival of normal BM cells was 77.4 +/- 12 and 70.3 +/- 10%, respectively. BM leukemic cells from children with ALL and AML were also very sensitive to Mc 540 photoirradiation in contrast to neuroblastoma cells where only a three-fold reduction was observed. Finally, the survival of normal BM progenitors was 38% for colony forming unit erythroid CFU-E, 37% for burst forming unit erythroid BFU-E, 55% for CFU-GM and 29% for CFU-GEMM. In conclusion it seems that Mc 540 mediated photoirradiation in neoplastic cells exerts selective cytotoxicity and can be used in ex vivo purging of malignant cells in BM.

Laser-induced fluorescence detection of malignancies in the female genital tract via their natural emission and hypocrellin (HA) probing

A laser-induced fluorescence-guided biopsy system has been developed for the screening and early detection of malignancies in the female inner/outer genital tract. Fluorescence spectra were recorded during exposure of normal and malignant tissue to He-Cd laser (442 nm) radiation. A characteristic increase in the fluorescence signal at 600 nm for malignant tissue was observed after treatment of the samples with hypocrellin (HA). This, combined with the spectral distribution of tissue natural fluorescence, allowed for the development of simple algorithms, based on the intensity difference. A subsequent index of discrimination between normal and various malignant tissues has been calculated. These results suggest that monitoring of this index during colposcopy could enhance selective detection of the malignant tissue, reducing the risk of leaving pathologic tissue untreated during standard exploratory surgical procedures.

Alteration in gene expression of branched-chain keto acid dehydrogenase kinase but not in gene expression of its substrate in the liver of clofibrate-treated rats

We previously showed that the oxidation of branched-chain amino acids is increased in rats treated with clofibrate [Paul and Adibi (1980) J. Clin. Invest. 65, 1285-1293]. Two subsequent studies have reported contradictory results regarding the effect of clofibrate treatment on gene expression of branched-chain keto acid dehydrogenase (BCKDH) in rat liver. Furthermore, there has been no previous study of the effect of clofibrate treatment on gene expression of BCKDH kinase, which regulates the activity of BCKDH by phosphorylation. The purpose of the present study was to investigate the above issues. Clofibrate treatment for 2 weeks resulted in (a) a 3-fold increase in the flux through BCKDH in mitochondria isolated from rat liver, and (b) a modest but significant increase in the activity of BCKDH. However, clofibrate treatment had no significant effect on the mass of E1 alpha, E1 beta, and E2 subunits of BCKDH or the abundance of mRNAs encoding these subunits. On the other hand, clofibrate treatment significantly reduced the activity, the protein mass and the mRNA levels of BCKDH kinase in the liver. In contrast to the results obtained in liver, clofibrate treatment had no significant effect on any of these parameters of BCKDH kinase in the skeletal muscle. In conclusion, our results show that clofibrate treatment increases the activity of BCKDH in the liver and the mechanism of this effect is the inhibition of gene expression of the BCKDH kinase.

Effect of diffraction on early-arriving photons during femtosecond laser transillumination of highly scattering media of biological significance

Early-arriving photons of 100-fs laser pulses transmitted through highly scattering media have been detected by a streak camera. Because of their partial spatial coherence, they are affected by diffraction from small hidden discontinuities. The experimental data of the patterns are analyzed with Fresnel diffraction theory and then corrected accordingly. Submillimeter hidden objects were scanned and imaged. Diffraction correction resulted in a significantly improved contrast in the hidden object's image.

Regulation of gene expression of branched-chain keto acid dehydrogenase complex in primary cultured hepatocytes by dexamethasone and a cAMP analog

The present study demonstrates that dexamethasone and 8-(4-chlorophenylthio)adenosine 3',5'-monophosphate (CPT-cAMP), a cAMP analog, increase the substrate flux through branched-chain keto acid dehydrogenase (BCKDH) in primary rat hepatocytes cultured in defined medium. Maximum response (2.7-fold increase in flux) was observed when hepatocytes were cultured with 1 microM dexamethasone plus 50 microM CPT-cAMP for 24 h. This increase in the flux rate was accompanied by significant increases in both the basal and total activities of BCKDH (2.2- and 2.0-fold, respectively), without any significant change in the activity state of this enzyme. The increase in BCKDH activity was the result of increased protein mass of E1 alpha (3.2-fold), E1 beta (2.9-fold), and E2 (1.6-fold) subunits of BCKDH, indicating that E2 is the limiting subunit for the expression of BCKDH. The relative abundance of mRNAs encoding the E1 alpha, E1 beta, and E2 subunits of BCKDH increased by 7.4-, 21.7-, and 4.8-fold, respectively. We conclude that increased flux through BCKDH in hepatocytes cultured with dexamethasone and CPT-cAMP is due to increased expression of BCKDH subunit genes. However, nonstoichiometric expression of individual subunits and the corresponding mRNAs suggests regulation of BCKDH also at translational and post-translational steps.

The study of health effects of vinyl chloride air pollution on population

A series of indicators, including serum lysozyme activity, G-banding chromosome aberration (G-banding CA) analysis, sister chromatid exchanges (SCEs), chromosome aberration (CA), T-lymphocyte transformation rate (TcTR), gamma-GT, GPT and AKP, were employed in the present survey among occupationally vinyl chloride (VC) exposed workers and inhabitants living in VC polluted area in a polyvinyl chloride (PVC) factory. The results showed that the serum lysozyme (S-LZM) activities in Group 3 (adult inhabitants exposed to 0.20 mg/m3 VC for at least 8 years), Group 2 (workers exposed to 4.1 mg/m3 for at least 7 years occupationally), Group 1 (workers exposed to 25.7 mg/m3 for at least 2 years) were significantly higher than control. G-banding CA analysis showed that the total chromosome breakage rates in both Groups 1 and 2 were higher, but no difference existed between Group 3 and control. Only Group 1 was observed having higher SCEs, CA level and lower TcTR than control. AKP levels in Groups 1 and 2 were higher than control, but no gamm-GT and GPT differences were found among groups. The study also suggests that G-banding CA analysis is more sensitive than CA and SCEs.

Laser-induced fluorescence detection of cardiovascular atherosclerotic deposits via their natural emission and hypocrellin (HA) probing

In order to develop a reliable laser-induced-fluorescence-guided angioplasty system, fluorescence spectra were recorded during exposure of normal and atherosclerotic cadaveric aortic tissue to He-Cd laser radiation (442 nm). A characteristic increase in the fluorescence signal at 600 nm for atheromatous tissue was observed after treatment of the samples with hypocrellin (HA). This, combined with the spectral distribution of tissue natural fluorescence, allowed the development of simple algorithms, based on the intensity difference and the full width at half-maximum (FWHM), and a subsequent index of discrimination between normal and various atheromatous tissues. Our results suggest that monitoring of this index through the catheter could enhance selective ablation, reducing the risk of normal vessel perforation.

Time-gated fluorescence spectroscopy of the tumor localizing fraction of HpD in the presence of cationic surfactant

Time-gated fluorescence spectroscopy was performed on the tumor localizing fraction (TLF) of HpD in buffer at different concentrations of cationic surfactant. This technique obtains emission spectra with programmable delay relative to the excitation pulse. According to the measured fluorescence decay-time constants (approximately 0.7, approximately 3 and approximately 15 ns) three gates were considered, delayed by 0, 5 and 18 ns, respectively, to evaluate the contribution of the emitting molecular species to the spectra. Simultaneous to these measurements, fluorescence decay waveforms and time-integrated spectra were also detected. In buffer and in detergent micelles the fluorescence spectra are given by the superposition of the emission of the different molecular species present in the solution, and no appreciable interaction among the chromophores is observed. On the contrary, in the pre-micellar range of the surfactant, evidence for the existence of an energy transfer mechanism was found. This effect seems to be related to the configurational state of the TLF polymeric chains and depends on the relative TLF/surfactant concentration.

Relationship between acupuncture-induced immunity and the regulation of central neurotransmitter system in rabbits--II. Effect of the endogenous opioid peptides on the regulation of acupuncture-induced immune reaction

By injecting Naloxone, the T-lymphocyte transformation was reduced markedly. When the Naloxone plus electro-acupuncture were used together, it was not reduced but was still lower than it was when only electro-acupuncture was used. This explained why Naloxone could reverse the function by which electro-acupuncture promoted the T-lymphocyte transformation, and the endogenous opioid in the brain promoted the immune reaction. Through promoting the release of the endogenous opioid in the brain, electro-acupuncture raised the T-lymphocyte transformation function. Using electro-acupuncture when naloxone antagonized morphine, the T-lymphocyte transformation function was still promoted markedly. The mechanism could be that electro-acupuncture excited the function of the endogenous opioid system in the brain. In acupuncture immune reaction, the relationship between the endogenous opioid and catecholaminergic systems was explored.