Blood cell-mediated cytotoxic activity in the solitary ascidian Ciona intestinalis.
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Animals↗
Biomedical subjects
V J Smith
Publications and source records attributed to V J Smith.
In vitro spontaneous cytotoxic activity against mammalian target cells by the hemocytes of the solitary ascidian, Ciona intestinalis.
Blood cell-mediated cytotoxic activity against mammalian target cells by the hemocytes of the solitary ascidian Ciona intestinalis was investigated in vitro by fluorochromasia. Salt-conditioned target cells were labeled with carboxyfluorescein diacetate and challenged with mixed and separated hemocytes. The assay provided optimal conditions for the functioning of the effector hemocytes while maintaining low background leakage from the target cells. Comparison of different hemocyte populations, separated by density gradient centrifugation, revealed that only cell bands containing the phagocytic and nonphagocytic amoebocytes exhibited cytotoxicity. Experiments to characterize cytolysis demonstrated that activity increased with the effector to target cell ratio, occurred within 15 min, and was maximal at an incubation temperature of 20 degrees C. Both human (K562) and mouse [YAC-1, P815, WEHI (3B) and L929] target cell lines were killed by the ascidian effector hemocytes. This paper demonstrates a population of nonspecific cytotoxic effector cells in the blood of C. intestinalis that are able to spontaneously kill a range of mammalian targets in vitro.
Animals↗
Radiation disease of the urinary tract: histological features of 18 cases.
AIMS: To study the spectrum of histological changes in the urinary tract caused by pelvic irradiation. METHODS: Biopsy specimens of ureter and bladder and cystectomy specimens from 18 patients who had received pelvic irradiation were studied and the histological features were arbitrarily grouped into early and late changes. RESULTS: A wide range of histological changes were noted of which submucosal inflammation, fibrosis, and epithelial damage were the commonest. Other less common features were interstitial haemorrhage, ureteritis and cystitis cystica, squamous metaplasia of vaginal type and perineural inflammation. CONCLUSIONS: Although epithelial changes were most prominent in early cases and stromal changes in the late cases, there was a continuing spectrum of epithelial damage which persisted many years after initial radiation. Similarly, submucosal fibrosis was equally prominent in early and late phases.
Adult↗
Benign cystic peritoneal mesothelioma.
The well defined but rare entity of benign cystic mesothelioma is reported. The aetiology of this neoplasm remains obscure. The presenting features make a precise preoperative diagnosis difficult; information provided by computed tomography and cytology may help. A firm diagnosis can only come from electron microscopic or immunohistochemical examination of the tumour. Diagnostic accuracy and diligent follow up are essential because, although the tumour is considered benign, it does tend towards local recurrence.
Cysts↗
Differential haemotoxic effect of PCB congeners in the common shrimp, Crangon crangon.
1. Specimens of the common shrimp, Crangon crangon, were exposed to sub-acute logarithmically separated concentrations (ranging from 0.05 microgram to 500 micrograms l-1) of two structurally dissimilar PCB congeners (PCB 15 and PCB 77) for five days in vitro. 2. Mortality, recoverable haemolymph volume, haemocyte count, plasma protein and haemolymph osmolarity were determined for test animals together with levels of haemolymph cell prophenoloxidase, an indicator of immune potential. 3. Sub-acute concentrations of PCB 15, but not PCB 77, produced significant decreases in haemocyte count and phenoloxidase activity with a marked increase in recoverable haemolymph volume. 4. No effect was observed on haemolymph osmolarity or plasma protein levels with either PCB 77 or PCB 15.
Animals↗
A comparison of phenoloxidase activity in the blood of marine invertebrates.
A range of marine invertebrates were screened for prophenoloxidase (a marker protein of the prophenoloxidase activating system) in the coelomic fluid or hemolymph. The crustaceans and the ascidian, Ciona intestinalis, displayed strongest activity, with low levels found in the starfish, Asterias rubens, the sea urchin, D. antillarum, and the brachiopod, Liothyrella uva. The enzyme appeared to be absent from the isopod, Glyptonotus antarcticus. Further analyses of the blood cells of selected species revealed that prophenoloxidase tends to reside in the granular-type cells or their equivalent, and in the crustaceans and C. intestinalis is activated by lipopolysaccharides. In arthropods, prophenoloxidase is known to represent the terminal component of a complex cascade of enzymes that functions in non-self-recognition and host defence. The present study establishes that the enzyme is present in the blood cells of most, but not all, crustaceans and occurs in certain other invertebrate species, notably the urochordate, C. intestinalis.
Animals↗
Nodular regenerative hyperplasia of the liver in a non-treated patient with mesangiocapillary glomerulonephritis.
The recognition of nodular regenerative hyperplasia of the liver in patients with renal transplant is well-known. This report, we believe, is the first well-documented case of nodular regenerative hyperplasia in a patient with chronic renal disease and who had not been transplanted.
Glomerulonephritis, Membranoproliferative↗
Induction of degranulation and lysis of haemocytes in the freshwater crayfish, Astacus astacus by components of the prophenoloxidase activating system in vitro.
To study the role of the prophenoloxidase activating system, an enzyme cascade located in the haemocytes of crustaceans, in the cellular defences of the freshwater crayfish, Astacus astacus in vitro, monolayer cultures of mixed or separated haemocyte populations, isolated by density gradient centrifugation, were challenged with the bacterium, Moraxella sp. pre-coated with phenoloxidase and the other attaching proteins in crayfish haemocyte lysate (HLS), or in the case of controls, with saline or Moraxella sp. pre-incubated in saline alone. Examination of the coverslips 1 h after inoculation revealed that, in the mixed haemocyte cultures, most of the cells had undergone profound degranulation and lysis following exposure to the HLS-coated bacteria. Cell lysis was also evident in the experimental semigranular cell monolayers, but not in the controls, although in those controls treated with the saline-incubated bacteria, the semigranular haemocytes had undergone degranulation without lysis. In contrast, the granular cells appeared to be unaffected by the saline-incubated Moraxella sp., and with the HLS-coated bacteria displayed only marked degranulation. Greater numbers of bacteria were always associated with the cells or cell remnants in the experimental cultures compared to the controls. We suggest that the attaching proteins of the prophenoloxidase cascade are strong nonself signals for the haemocytes, causing them to degranulate and release previously cell-bound recognition factors into the haemolymph, where they are free to trigger activation of adjacent haemocytes.
Animals↗
Separation of the haemocyte populations of Carcinus maenas and other marine decapods, and prophenoloxidase distribution.
Three morphologically distinct populations of haemocytes; the granular, semigranular and hyaline cells; were isolated from the haemolymph of Carcinus maenas and other decapod crustaceans by density gradient centrifugation. Cell lysis and coagulation during separation were prevented, without significant loss of cell viability, by the use of citrate/EDTA buffer at low pH as an anticoagulant. Biochemical analyses of the haemocyte fractions revealed that prophenoloxidase is present in the granular and semigranular cells, but not the hyaline cells, and, thus, is a useful marker for cell purity in the hyaline haemocyte populations. A method for rapidly detecting prophenoloxidase contamination of the hyaline cells using L-dopa and trypsin in drop assay is described.
Animals↗
Coumarin antibiotic binding to human albumin.
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Binding Sites↗
Correlation of hydrophobicity with protein binding for clorobiocin analogs.
A new method of equilibrium dialysis was used to measure the binding of analogs of clorobiocin (18631 R.P.) to human serum albumin. Binding constants and numbers of binding sites on human serum albumin were calculated from the binding data and were used to calculate the percentage of compounds free in equilibrium with 4% albumin. Partition coefficients between n-octanol and phosphate buffer (0.05 M, pH 7.4) also were measured. A positive linear correlation (r = 0.918, s = 0.240, and n = 10) was obtained between log (bound/free compound) and log partition coefficient.
Chemical Phenomena↗
Blood plasma binding of acebutolol and diacetolol in man.
1 Acebutolol or diacetolol were added to fresh human plasma in varying concentrations and their extent of binding at 25 degrees C measureed by an equilibrium dialysis technique. 2 The extent of binding for both compounds was shown to be very low, being 11-19% for acebutolol and 6-9% for diacetolol. 3 Partition coefficients were measured in an n- octanol/phosphate buffer (0.05M, pH 7.4) solvent system. For a cebutolol, P = 0.62 and for diacetol, P = 0.08. 4 The very low plasma binding is in accord with the hydrophilic partition coefficients of these compounds.
Acebutolol↗
In vitro phenoloxidase activity in the blood of Ciona intestinalis and other ascidians.
The presence and activation of phenoloxidase in the blood of Ciona intestinalis and other ascidians was investigated in vitro. In C. intestinalis, phenoloxidase was found to exist in the cells as a proenzyme and to be activated by proteases. The microbial carbohydrates, LPS or laminarin, also enhanced enzyme activity but a similar effect was not achieved with other sugars. Calcium was not essential for enzyme activity and no enzyme suppression was seen at high calcium concentrations. Prophenoloxidase activation by LPS was further found to be dose related and inhibited by PTU and tropolone. Since benzamidine and STI reduced phenoloxidase activity in cell lysate supernatants, activation may involve other factors, possibly a serine protease. Lastly, as phenoloxidase activity was detected in the blood cells (usually the morula cells) of eight other ascidian species, it appears that it is widely distributed in the blood of this group of invertebrates.
Animals↗
In vitro superoxide production by hyaline cells of the shore crab Carcinus maenas (L.).
This study examines the phagocytic hyaline cells of the shore crab, Carcinus maenas, for a respiratory burst in vitro. Following stimulation of the cells with phorbol myristate acetate (PMA), ferricytochrome c was reduced at 550 nm. Addition of superoxide dismutase (SOD) to the reaction mixture decreased this reduction, confirming that superoxide ions are produced by the stimulated hemocytes. Phytohemagglutinin, con A, and LPS were also shown to stimulate the cells although laminarin failed to elicit a burst. This is the first demonstration of a respiratory burst for crustacean hemocytes.
Animals↗
Proliferation of undifferentiated blood cells from the solitary ascidian, Ciona intestinalis in vitro.
The proliferative responses of the cytotoxic blood cell population of the solitary ascidian, Ciona intestinalis, were investigated by autoradiography and tritiated thymidine (3H-TdR) incorporation following treatment with mitogens or co-culture with allogeneic cells in vitro. A small number of mitotic figures were seen in untreated circulating blood cells and pulse labelling with 3H-TdR showed that only the undifferentiated "lymphocyte-like" cells within the enriched cytotoxic cell population undergo spontaneous cell division and DNA synthesis in the circulation. Treatment of the cells, cultured for 4 days, with concanavalin A (con A), phytohaemagglutinin-B (PHA-B) or lipopolysaccharide (LPS) produced significantly increased 3H-TdR incorporation, although there were differences in the sensitivity of the cells to mitogen concentration. Significantly enhanced proliferation was also observed following incubation with mitomycin C-treated cells from allogeneic individuals. These results show that the cytotoxic blood cell population of C. intestinalis is capable of mitogen-induced proliferation as well as mixed lymphocyte-type responses and therefore shares some proliferative characteristics with vertebrate lymphocytes.
Animals↗
Monitor-based software application programs meet the need for fast, accurate information at the bedside.
This article describes how the availability of applications programs on bedside and central station monitors increases nursing efficiency, enhances patient safety, and reduces hospital costs. Included are descriptions of some specific applications programs that comprise the Space-Labs Clinical Library: continuing education credit programs, drug therapy programs and a pacemaker information retrieval database. The benefits of these monitor-based programs--for both nurses and hospitals--are described.
Drug Therapy↗
Determination of aspartame in beverages using an alcohol oxidase enzyme electrode.
A new method for the determination of the artificial sweetener aspartame is described. alpha-Chymotrypsin is used to cleave the methyl ester group of aspartame, producing methanol hydrolytically. The methanol is detected using an electrode which is constructed by physically trapping yeast alcohol oxidase enzyme at the tip of a dissolved oxygen electrode. The decrease in oxygen concentration, which occurs as methanol is enzymatically oxidized to formaldehyde, is measured amperometrically. Aspartame levels in diet soft drinks as determined by the proposed method and by liquid chromatography are in excellent agreement. The relative standard deviation of the measurements is 0.83%. The methanol present in diet cola as a result of aspartame degradation can also be measured by using the electrode without alpha-chymotrypsin.
Alcohol Oxidoreductases↗