Luminol-amplified chemiluminescence activity in human monocytes: A comparison with the activity induced in granulocytes

The characteristics of the luminol-amplified chemiluminescence (CL) induced in mononuclear phagocytes interacting with PMA, FMLP or ionomycin were determined. Azide reduced the CL activity by more than 80%, while superoxide dismutase and catalase had minor effect on the monocyte CL response. The sensitivity of the monocyte CL response, to the addition of extra peroxidase differed depending on the stimulus used. Furthermore, no direct correlation was obtained between the CL response and superoxide anion or hydrogen peroxide production. In comparison with the response in granulocytes, minor quantitative differences were observed. The mechanism for the light-generating reaction, seems to be the same in both cell types.     

Metabolic activity in the saccus vasculosus of the rainbow trout,salmo gairdneri (richardson)

Summary Labelling experiments to test mucopolysaccharide synthesis in the saccus vasculosus of the rainbow trout gave negative results and provoked analysis of succinic dehydrogenase activity in the coronet cells. Such activity was almost absent in the fresh-water living rainbow trout but was intense in sea water adapted individuals as well as in a sea water teleost, the flounder. Conversely, in sea water adapted rainbow trout which had been transferred back to fresh-water, activity had again decreased. In the sea water adapted rainbow trout high succinic dehydrogenase activity was paralleled by strongly positive staining with alcian blue, indicating the presence of mucopolysaccharides. The latter fishes also showed incorporation of N-acetyl-³H-glucosamine. Our findings indicate a role for saccus vasculosus in adaptation for osmoregulation in sea water and favour the hypothesis of a secretory function for the coronet cells.This work has been supported by grants from the Royal Physiographical Society of Lund and the Faculty of Natural Sciences at the University of Lund. We are greatly indebted to Mrs. Lena Eriksson, Mrs. Kristine Fogelström and Mrs. Lena Svenre for excellent technical assistance.     

Nuclear maturation of follicle-enclosed rat oocytes during inhibition of steriodogenesis

This study examined the possible role of steriods in meiotic maturation of preovulatory oocytes. Follicles were isolated from PMSG-treated immature rats and incubated with or withour LH in the presence of one of four inhibitors of steroidogenesis. The inhibitors employed had different sites of attack in the steriodogenic pathway and were aminoglutethimide, cyanoketone, SU 10603 (17β-hydroxylase inhibitor), and 4-OH-androstenedione (aromatase inhibitor). As predicted, the inhibitors drastically altered the pattern of steroid production. None of the inhibitors, however, changed the proportion of oocytes resuming or completing meiosis in response to LH, and there was also no effect of the inhibitors on the oocytes in the absence of LH. It was concluded that steriods are not required for preovulatory nuclear maturation of oocytes in the rat.     

Implantable self‐aligning fiber‐optic optomechanical devices for in vivo intraocular pressure‐sensing in artificial cornea

Artificial cornea is an effective treatment of corneal blindness. Yet, intraocular pressure (IOP) measurements for glaucoma monitoring remain an urgent unmet need. Here, we present the integration of a fiber‐optic Fabry‐Perot pressure sensor with an FDA‐approved keratoprosthesis for real‐time IOP measurements using a novel strategy based on optical‐path self‐alignment with micromagnets. Additionally, an alternative noncontact sensor‐interrogation approach is demonstrated using a bench‐top optical coherence tomography system. We show stable pressure readings with low baseline drift (<2.8 mm Hg) for >4.5 years in vitro and efficacy in IOP interrogation in vivo using fiber‐optic self‐alignment, with good initial agreement with the actual IOP. Subsequently, IOP drift in vivo was due to retroprosthetic membrane (RPM) formation on the sensor secondary to surgical inflammation (more severe in the current pro‐fibrotic rabbit model). This study paves the way for clinical adaptation of optical pressure sensors with ocular implants, highlighting the importance of controlling RPM in clinical adaptation.     

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Analysis of luminol-dependent chemiluminescence from granule depleted neutrophil cytoplasts reveals two different light-emitting mechanisms

When neutrophil cytoplasts (granule-free vesicles of cytoplasm enclosed by plasmalemma) were exposed to the chemotactic peptide formylmethionyl-leucyl-phenylalanine, no luminol-dependent chemiluminescence was detected, despite a pronounced production of superoxide anions and hydrogen peroxide. Addition of purified myeloperoxidase (MPO) or human serum albumin (HSA) to the cytoplasts before the stimulus resulted in a chemiluminescence response. In contrast to the bimodal response obtained from normal PMNL, only a single peak of chemiluminescence was obtained from the cytoplasts responding to the peptide. The time-course of the response obtained in the presence of albumin was more prolonged than the response obtained in the presence of MPO. Furthermore, the involvement of different oxidative metabolites in the MPO and the HSA systems, respectively, was demonstrated by the accumulated chemiluminescence effect obtained when MPO, but not HSA, was introduced in the measuring system after FMLP addition. From these results it can be concluded that there are at least two different light-generating mechanisms in FMLP-induced luminol-dependent chemiluminescence of neutrophil cytoplasts. One of these is dependent on myeloperoxidase and possibly related to the myeloperoxidase-hydrogen peroxide reaction, whereas the other one is hydrogen peroxide independent.