Exercise plasma boosts memory and dampens brain inflammation via clusterin

Physical exercise is generally beneficial to all aspects of human and animal health, slowing cognitive ageing and neurodegeneration¹. The cognitive benefits of physical exercise are tied to an increased plasticity and reduced inflammation within the hippocampus^2-4, yet little is known about the factors and mechanisms that mediate these effects. Here we show that 'runner plasma', collected from voluntarily running mice and infused into sedentary mice, reduces baseline neuroinflammatory gene expression and experimentally induced brain inflammation. Plasma proteomic analysis revealed a concerted increase in complement cascade inhibitors including clusterin (CLU). Intravenously injected CLU binds to brain endothelial cells and reduces neuroinflammatory gene expression in a mouse model of acute brain inflammation and a mouse model of Alzheimer's disease. Patients with cognitive impairment who participated in structured exercise for 6 months had higher plasma levels of CLU. These findings demonstrate the existence of anti-inflammatory exercise factors that are transferrable, target the cerebrovasculature and benefit the brain, and are present in humans who engage in exercise.

Use of single-cell imaging techniques to assess the regulation of cAMP dynamics

cAMP is a ubiquitous intracellular signalling molecule that can regulate a wide array of cellular processes. The diversity of action of this second messenger owes much to the localized generation, action and hydrolysis of cAMP within discrete subcellular regions. Further signalling specificity can be achieved by the ability of cells to modulate the frequency or incidence of such cAMP signals. Here, we discuss the use of two cAMP biosensors that measure real-time cAMP changes in the single cell, to address the mechanisms underlying the generation of dynamic cAMP signals. The first method monitors sub-plasmalemmal cAMP changes using mutant cyclic nucleotide-gated channels and identifies an AKAP (A-kinase-anchoring protein)-protein kinase A-PDE4 (phosphodiesterase-4) signalling complex that is central to the generation of dynamic cAMP transients in this region of the cell. The second study uses a fluorescence resonance energy transfer-based cAMP probe, based on Epac1 (exchange protein directly activated by cAMP 1), to examine interplay between Ca(2+) and cAMP signals. This study demonstrates real-time oscillations in cAMP driven by a Ca(2+)-stimulated AC (adenylate cyclase) (AC8) and subsequent PDE4 activity. These studies, using two very different single-cell cAMP probes, broaden our understanding of the specific spatiotemporal characteristics of agonist-evoked cAMP signals in a model cell system.

A CNS-managed diabetes foot-care clinic: a descriptive survey of characteristics and foot-care behaviors of the patient population

Lower extremity lesions are the primary cause of hospitalization for people with diabetes, resulting in enormous personal and financial costs. This study used a survey designed to describe the characteristics and foot-care behaviors of people with diabetes who attended a clinical nurse specialist managed foot-care clinic. Forty-eight patients who received care at the participating foot-care clinic completed a 21-item multiple-choice questionnaire designed to determine the presence of foot pathology and foot-care behaviors. Most of the patients were between 65 and 74 years of age, had concurrent illnesses, and had four or more primary care visits per year. Although 69% had existing foot pathology, only 44% reported inspecting their feet daily and only 54% reported that their primary care provider examined their feet on each visit. Twenty-five percent reported going barefoot sometimes and eight percent would either treat a foot lesion themselves or wait for it to get better.

The effects of intracellular pH changes on resting cytosolic calcium in voltage-clamped snail neurones

We have investigated the effects of changing intracellular pH on intracellular free calcium concentration ([Ca2+]i) in voltage-clamped neurones of the snail Helix aspersa. Intracellular pH (pHi) was measured using the fluorescent dye 8-hydroxypyrene-1,3,6-trisulphonic acid (HPTS) and changed using weak acids and weak bases. Changes in [Ca2+]i were recorded using either fura-2 or calcium-sensitive microelectrodes. Acidification of the neurones with 5 mM or 20 mM propionate (approximately 0.2 or 0.3 pH units acidification, respectively) caused a small reduction in resting [Ca2+]i of 5 +/- 2 nM (n = 4) and 7 +/- 16 nM (n = 4), respectively. The removal of the 20 mM propionate after approximately 40 min superfusion resulted in an alkalinization of approximately 0.35 pH units and an accompanying rise in resting [Ca2+]i of 31 +/- 9 nM (n = 4, P < 0.05). The removal of 5 mM propionate did not significantly affect [Ca2+]i. Alkalinizations of approximately 0.2-0.4 pH units of Helix neurones induced by superfusion with 3 mM concentrations of the weak bases trimethylamine (TMA), ammonium chloride (NH4Cl) and procaine were accompanied by significant (P < 0.05) increases in resting [Ca2+]i of 42 +/- 4 nM (n = 26), 30 +/- 7 nM (n = 5) and 36 +/- 4 nM (n = 3), respectively. The effect of TMA (0.5-6 mM) on [Ca2+]i was dose dependent with an increase in [Ca2+]i during pHi increases of less than 0.1 pH units (0.5 mM TMA). Superfusion of neurones with zero calcium (1 mM EGTA) Ringer solution inhibited depolarization-induced calcium increases but not the calcium increase produced by the first exposure to TMA (3 mM). In the prolonged absence of extracellular calcium (approximately 50 min) TMA-induced calcium rises were decreased by 64 +/- 10% compared to those seen in the presence of external calcium (P < 0.05). The calcium rise induced by TMA (3 mM) was reduced by 60 +/- 5% following a 10 min period of superfusion with caffeine (10 mM) to deplete the endoplasmic reticulum (ER) stores of calcium (P < 0.05). Cyclopiazonic acid (10-30 microM CPA), an inhibitor of the ER calcium pump, inhibited the calcium rise produced by TMA (3 mM) and NH4Cl (3 mM) by 61 +/- 4% compared to controls (P < 0.05). These data are consistent with physiological intracellular alkaline shifts stimulating release of calcium, or inhibiting re-uptake of calcium by an intracellular store. The calcium increase was much reduced following application of caffeine, treatment with CPA or prolonged removal of external calcium. Hence the ER was likely to be the source of mobilized calcium.

Type C botulism in dairy cattle from feed contaminated with a dead cat

Four hundred twenty-seven of 441 adult Holstein dairy cattle from a 1,200-cow dairy died over a 1-week period during early spring 1998. Affected animals were from 4 late lactation pens, one of which included the bull string. Signs included weakness, recumbency, watery diarrhea, and death. Eighty animals from the 4 pens were dead approximately 8 hours after the first ill cows were noted. Affected cows would collapse on stimulation and extend all 4 limbs with moderate rigidity. Several lacked lingual tonus and had abdominal breathing patterns. The animals had been fed a load of total mixed ration that included a rotten bale of oat hay containing a dead cat. No common toxicants were identified, and pathologic examination revealed no consistent lesions. Testing of tissue from the cat carcass found in the feed sample using mouse protection bioassay identified the presence of type C botulinum toxin. Samples of feed, tissue from affected animals, cat tissue from feed, milk, and serum were also tested using an enzyme-linked immunosorbent assay (ELISA) specific for type C botulinum. Two samples of rumen contents were tested and found to be positive for botulism by ELISA, and 1 of 3 liver samples had a weak positive finding. No botulinum toxin was found in milk or sera using the ELISA.

A role for Na+/H+ exchange in pH regulation in Helix neurones

We have used the pH-sensitive fluorescent dye 8-hydroxypyrene-1,3,6-trisulphonic acid (HPTS) to reexamine the mechanisms that extrude acid from voltage-clamped Helix aspersa neurones. Intracellular acid loads were imposed by three different methods: application of weak acid, depolarization and removal of extracellular sodium. In nominally CO2/HCO3-free Ringer the rate of recovery from acid loads was significantly slowed by the potent Na+/H+ exchange inhibitor 5-[N-ethyl-N-isopropyl]-amiloride (EIPA, 50 microM). Following depolarization-induced acidifications the rate of intracellular pH (pHi) recovery was significantly reduced from 0.41 +/- 0.13 pH units.h-1 in controls to 0.12 +/- 0.09 pH units.h-1 after treatment with EIPA at pHi approximately equal to 7.3 (n = 7). The amiloride analogue also reduced the rate of acid loading seen during extracellular sodium removal both in the presence and absence of the Na(+)-dependent Cl-/HCO3- exchange inhibitor 4-acetamido-4'-isothiocyanato-stilbene-2,2'-disulphonic acid (SITS, 50 microM). This is consistent with EIPA inhibiting reverse-mode Na+/H+ exchange. In 2.5% CO2/20 mM HCO3-buffered Ringer pHi recovery was significantly inhibited by SITS, but unaffected by EIPA. Our results indicate that there are two separate Na(+)-dependent mechanisms involved in the maintenance of pHi in Helix neurones: Na(+)-dependent Cl-/HCO3- exchange and Na+/H+ exchange. Acid extrusion from Helix neurones is predominantly dependent upon the activity of Na(+)-dependent Cl-/HCO3- exchange with a lesser role for Na+/H+ exchange. This adds further weight to the belief that the Na+/H+ exchanger is ubiquitous.

Inositol-1,4,5-trisphosphate and inositol-1,3,4,5-tetrakisphosphate are second messenger targets for cardioactive neuropeptides encoded on the FMRFamide gene

This paper examines the importance of the calcium-mobilizing inositol phosphate pathway in mediating the effects of FMRFamide and its gene-related neuropeptides on the myogenic heart beat of the pond snail Lymnaea stagnalis. These peptides are encoded on a single exon of the FMRFamide gene and mediate diverse physiological effects in the isolated heart. The rate of production of inositol-1,4, 5-trisphosphate [Ins(1,4,5)P(3)] and inositol-1,3,4, 5-tetrakisphosphate [Ins(1,3,4,5)P(4)], measured using an HPLC method, were both significantly elevated in a concentration-dependent manner by FMRFamide (and were also elevated by FLRFamide). The threshold for increasing inositol phosphate production was low (100 pmol l(−1)) with a peak response occurring at 1 micromol l(−1) FMRFamide. The shape of the dose-response curve for FMRFamide-induced elevation of heart-beat frequency, obtained in pharmacological experiments on the isolated whole heart, was similar to that for stimulation of inositol phosphate levels in homogenized heart tissue. FMRFamide and Ins(1,4,5)P(3) produced similar effects on the rate of heart beat in permeabilized whole hearts. In addition, the phospholipase C inhibitor, neomycin (2.5 mmol l(−)(1)), blocked the stimulatory effects of FMRFamide on Ins(1, 4,5)P(3) production in heart homogenate, and attenuated the excitatory effects of this neuropeptide in the isolated heart. The ‘isoleucine’ pentapeptides, EFLRIamide and pQFYRIamide, also encoded by the FMRFamide gene, produced no significant effects on inositol phosphate production when applied alone or in combination with FMRFamide. These results suggested that FMRFamide (and FLRFamide), but not EFLRIamide and pQFYRIamide, mediated their main effects on heart beat via the inositol phosphate pathway. The fifth peptide, SEQPDVDDYLRDVVLQSEEPLY (‘SEEPLY’) had no effect when applied alone but appeared to modulate the effects of FMRFamide by delaying the time-to-peak of the Ins(1,4,5)P(3) response from 5 s to 20 s by an unknown mechanism.

Cyclic AMP is involved in cardioregulation by multiple neuropeptides encoded on the FMRFamide gene

We have used a combination of biochemical and pharmacological techniques to investigate the role of the cyclic nucleotides, 3′, 5′-cyclic adenosine monophosphate (cyclic AMP) and 3′,5′-cyclic guanosine monophosphate (cyclic GMP), in mediating the cardioregulatory effects of FMRFamide and other neuropeptides encoded on exon II of the FMRFamide gene of Lymnaea stagnalis. The ‘isoleucine’ peptides (EFLRIamide and pQFYRIamide) produced complex biphasic effects on the frequency, force of contraction and tonus of the isolated heart of L. stagnalis, which were dependent on adenylate cyclase (AC) activity of the heart tissue. At a control rate of cyclic AMP production of less than or equal to 10 pmoles min(−)(1)mg(−)(1) protein, the ‘isoleucine’ peptides produced a significant increase in AC activity in heart membrane preparations. This suggested that the enhanced AC activity is responsible for the stimulatory effects of the ‘isoleucine’ peptides on frequency and force of contraction of heart beat. This excitation sometimes followed an initial ‘inhibitory phase’ where the frequency of beat, force of contraction and tonus of the heart were reduced by the ‘isoleucine’ peptides. Hearts that showed the inhibitory phase of the ‘isoleucine’ response, but characteristically lacked the delayed excitatory phase, were found to have high levels of membrane AC activity (breve)10 pmoles min(−)(1)mg(−)(1) protein in controls. Application of the ‘isoleucine’ peptides to membrane homogenate preparation from these hearts failed to increase AC activity. The addition of FMRFamide produced significant increases in the rate of cyclic AMP production in the heart membrane preparations, which could account, at least in part, for the cardioexcitatory effects of this peptide in the isolated whole heart. A membrane-permeable cyclic AMP analogue (8-bromo-cyclic AMP) and an AC activator (forskolin) were also cardioexcitatory. The peptide SEEPLY had no effects on the beat properties of the isolated heart and did not alter AC activity. The activity of the membrane-bound (particulate) guanylate cyclase (GC) was not significantly affected by any of the peptides.

Comparison of simultaneous pH measurements made with 8-hydroxypyrene-1,3,6-trisulphonic acid (HPTS) and pH-sensitive microelectrodes in snail neurones

We have evaluated the pyrene-based ratiometric fluorescent dye, 8-hydroxypyrene-1,3,6-trisulphonic acid (HPTS), by using it in conjunction with glass pH-sensitive microelectrodes to measure intracellular pH (pHi) in voltage-clamped snail neurones. Intracellular acidification with propionic acid, and alkalinization following the activation of H+ channels allowed the calibration of the dye to be compared with that of the pH microelectrode over the pH range 6.50-7.50. HPTS calibrated in vitro and glass pH-sensitive microelectrodes produced similar absolute resting pHi values, 7. 16+/-0.05 (n=10) and 7.17+/-0.06 (n=9) respectively in nominally CO2/HCO3--free saline. At both extremes of the pH range there were small discrepancies. At acidic pHi, 6.87+/-0.09 (n=5), the intracellular HPTS measurement differed by -0.08+/-0.03 pH units from the pH-sensitive microelectrode measurement. At alkaline pHi, 7. 32+/-0.10 (n=5), HPTS measurements produced pH values that differed by +0.07+/-0.04 pH units from those of the pH-sensitive microelectrode. Some of the discrepancy could be accounted for by the slow response of the recessed-tip pH-sensitive microelectrode (time constant 77+/-15 s, n=3). Further experiments showed that HPTS, used at an intracellular concentration of 200 microM to 2 mM, did not block activity-dependent pHi changes. The intracellular HPTS concentration was calculated by measurement of intracellular chloride during a series of HPTS-KCl injections. Comparison of HPTS with 2',7'-bis(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF), at the same concentration, showed that HPTS produces a larger change in ratio over the pH range 6.00-8.00.

A survey for Salmonella by drag swabbing manure piles in California egg ranches

A cross-sectional study was conducted between August 1995 and November 1996. Sixty California egg-producing ranches were chosen at random; 39 ranches agreed to participate in the study. The surface of the manure pile in one house on each ranch was sampled by drag swabbing. The drag swabs were tested for Salmonella using a most probable number procedure that had a detection level of one to five Salmonella per drag swab. In 12 ranches (32.4%), the drag swabs were negative for Salmonella; the remaining had Salmonella counts in the range of 1 to over 1700 per swab. Twenty-two different serotypes were found. Salmonella heidelberg and Salmonella cerro represented the majority of the typed isolates. Salmonella enteritidis (SE) was found on only one ranch. This study found SE to be rare in California egg ranches, which implies that these ranches are not a major source of S. enteritidis.

A simple, efficient method for the separation of humic substances and DNA from environmental samples

Three different gels (Sepharose 4B, Sephadex G-200, and Sephadex G-50) were evaluated as a means of removing humic contaminants from DNA extracts of environmental samples. Sepharose 4B gave superior separation of DNA from humics, and DNA purified in this way showed consistently greater amplification than DNA purified by the other materials.

Animal exposure risks. Implications for occupational health nurses

1. Diseases transmitted from animals to humans, referred to as zoonoses, pose risks for persons occupationally exposed to animals. 2. Occupational health nurses should be proactive in identifying potential occupational health risks and educating employees to protect themselves from animal exposure risks. 3. Exposure history should include exposure to birds and animals during occupational and recreational activities. 4. Primary prevention is critical, as immunizations and treatments are limited and include many associated risks.

The depletion of substance P by diclofenac in the mouse

Diclofenac in hyaluronan is analgesic and angiostatic. The depletion of substance P may be a common mechanism. Mice received diclofenac, diclofenac in hyaluronan, or saline i.v. for 5 days and snout substance P assessed: saline 2.80 +/- 0.23; 0.5 mg/kg diclofenac 2.03 +/- 0.20 (P < 0.05); diclofenac in hyaluronan 1.88 +/- 0.21 (P < 0.02); capsaicin 1.45 +/- 0.26 fmol/mg tissue (P < 0.005). Substance P recovered by 5 days (diclofenac in hyaluronan, capsaicin) and 24 h (diclofenac). Diclofenac may deplete substance P in analgesia, and hyaluronan prolong the depletion.

Prevalence of Salmonella in municipal sewage treatment plant effluents in southern California

Effluents from 12 sewage treatment plants in southern California were examined for Salmonella using a Moore swab technique. Eight of the 12 plants were positive for Salmonella when sampled at the chlorination/dechlorination site (inside the plant). Effluents from 11 of 12 sewage treatment plants were positive for Salmonella when samples were analyzed downstream of the chlorination/dechlorination site, before effluents merge with the receiving stream (outside the plant). Two of the three control sites, an urban runoff, a raw potable water reservoir, and two other sites were also positive for Salmonella. A total of 683 Salmonella isolations were represented by 11 serogroups and 54 serotypes from 26 of 32 sampling sites. Effluents from three treatment plants and one control site (raw potable water resevior) yielded Salmonella enteritidis phage type 4, in addition to other serotypes.

Sewage effluent: likely source of Salmonella enteritidis, phage type 4 infection in a commercial chicken layer flock in southern California

Following the diagnosis of Salmonella enteritidis, phage type 4, infection in a commercial layer flock in southern California, effluent from a nearby sewer treatment plant was investigated as a potential source of infection. Between July 1994 and March 1995, 68 Salmonella isolations, comprising 27 serotypes, were made from the inflow (raw sewage) and effluent (treated sewage). Thirty-nine of 68 (57%) isolations yielded six serotypes, which consisted of S. enteritidis 12% (8/68), S. cerro 10% (7/68), S. typhimurium 7.4% (5/68), S. tennessee 7.4% (5/68), S. give 7.4% (5/68), S. mbandaka 7.4% (5/68), and S. panama 6% (4/68). The remaining 43% (29/68) isolations were represented by 21 serotypes. Seventeen S. enteritidis isolates originating from the effluent (creek water), resident feral animals (rodents, stray cats, skunks), and chickens (organs, eggs) of the affected flock were subjected to plasmid profile and restriction endonuclease analysis. Twelve of the 17 isolates had identical plasmid profile and restriction digestion patterns. Two of 17 isolates showed similar patterns but both differed from the rest; and 1 of 17 did not yield plasmids. Two other isolates were found to be different from each other and from the rest of the group.

Salmonella enteritidis, phase type 4 infection in a commercial layer flock in southern California: bacteriologic and epidemiologic findings

Salmonella enteritidis, phage type 4 (SE PT4), was isolated from five of six 27-wk-old layer chickens submitted for necropsy from a flock of 43,000. Bacteriologic and epidemiologic investigations on the ranch revealed that five of the eight flocks (n = 176,000) were infected. The prevalence of SE PT4 in randomly selected healthy birds ranged from 1.7% (in caged birds) to 50% (in free-range birds) and prevalence in culled birds (kept on dirt floor houses) ranged from 14% to 42%. The estimated overall prevalence of group D Salmonella in eggs contaminated with group D Salmonella was 2.28 per 10,000. The estimated prevalence of group D Salmonella in eggs from caged birds in three infected houses ranged from 1.5 to 4.1 per 10,000, whereas in two houses of free-range birds, prevalence was 14.9 to 19.1 per 10,000. Three of the eight flocks on the ranch remained negative for Salmonella between May 1994 and December 1995 or until removed from the ranch. Salmonella enteritidis PT4 was also isolated from 12.5% (6 of 48) of mice; 57% (four of seven) of cats; and two of two skunks tested. Environmental drag swabs and well water samples yielded multiple serotypes of Salmonella (23/180 and 5/14, respectively) but not S. enteritidis.

Complement C1qB and C4 mRNAs responses to lesioning in rat brain

These data show the presence of mRNAs for two complement components (C) in the adult rat brain and describe their responses to experimental lesions. Cortical deafferentation caused elevations in striatal C1qB and C4 mRNAs that coincided temporally and overlapped anatomically with the course of degeneration of corticostriatal afferent fibers. By in situ hybridization, C1qB mRNA in the lesioned striatum was colocalized to cells immunoreactive for CR3, a complement receptor found on microglia-macrophages. The mRNA for SGP-2, a putative C inhibitor in rat, showed parallel changes. Similarly, in hippocampus and other brain regions, kainic acid lesions increased C1qB mRNA. The data suggest that microglia-macrophages and possibly other cells in rat brain rapidly up-regulate C-mRNAs in response to deafferentation and local neuron injury. These experimental responses provide models to analyze changes in C components during Alzheimer's disease and other chronic neurodegenerative conditions.

Effects of follicle-stimulating hormone on inhibin release by different testicular compartments in the adult ram

The aim of this study was to determine the bidirectional release of immunoreactive inhibin-alpha (irINH-alpha) by different testicular compartments in the adult ram and to assess the effects of FSH on the distribution of inhibin in the testis. Immunoreactive INH-alpha was measured by RIA in fluid samples collected concurrently from the three testicular compartments--the seminiferous tubules, the interstitium, and the vascular system--through catheters inserted surgically into the rete testis, testicular lymphatic duct system, and spermatic veins, respectively. Overall, the concentration of irINH-alpha in rete testis fluid was 25 times the level in testicular lymph and over 500 times the concentration in peripheral blood. The pattern of irINH-alpha concentration in rete testis fluid was inversely related to that in testicular lymph, but i.v. administration of FSH had a decoupling effect on this relationship by depressing inhibin concentration in testicular lymph without affecting inhibin levels in rete testis fluid. Nevertheless, increased flow of testicular lymph more than compensated for the transient fall in irINH-alpha concentration so that, overall, the total output of inhibin via the testicular lymphatic duct system (and the vascular system) increased significantly. No persistent or significant changes were observed in the flow rate of rete testis fluid or concentration of irINH-alpha in the fluid after administration of FSH. The time frame for the response of the testis to FSH is indicative of the involvement of a mediator. Electrophoretic analysis of serially collected testicular lymph samples consistently revealed an FSH-induced release of a series of proteins in the M(r) range of 30,000-32,000.(ABSTRACT TRUNCATED AT 250 WORDS)

New areas for therapeutic intervention in the treatment of rheumatic disease

Anti-rheumatic therapy has been targeted against the symptoms arising from chronic inflammation of the joint. This has resulted in the extensive use of non-steroidal anti-inflammatory drugs. It is now becoming apparent that these agents have no beneficial effect on disease progression. This mini review concentrates on the formation and maintenance of pannus, the granulomatous tissue responsible for cartilage and bone erosion. This reveals a number of possible therapeutic targets. Protease inhibitors could be used to interfere with the degradatory processes. The diverse functions of endothelial cells suggest oedema formation, cell accumulation and supply of nutrients to the granulomatous tissue could all be targeted by appropriate therapy. Alternatively the immune processes that control pannus formation and state of activation could be regulated by interfering with antigen presentation and the cytokine network.

Diphenylene iodonium, an inhibitor of free radical formation, inhibits platelet aggregation

Diphenylene iodonium is an inhibitor of the enzyme NADPH-oxidase and prevents the generation of oxygen-derived free radicals in neutrophils (Cross and Jones, 1986). Here we show that diphenylene iodonium (0.25-2 microM) inhibited, according to the dose, thrombin-induced platelet-aggregation in human washed platelets and ADP-induced platelet aggregation in platelet-rich plasma. At the concentrations which inhibited platelet aggregation diphenylene iodonium did not alter platelet concentrations of cAMP or cGMP but enhanced the anti-platelet activity of iloprost, sodium nitroprusside or cultured endothelial cells. These findings highlight the importance of free radicals as platelet pro-aggregatory agents.

Crystal-induced inflammation, enzyme release and the effects of drugs in the rat pleural space

The pleural space of the rat has been used to study the acute inflammatory response to crystals of monosodium urate monohydrate, calcium pyrophosphate dihydrate and hydroxyapatite. Each crystal caused a brisk inflammatory response accompanied by crystal phagocytosis and release of lysosomal enzymes. These responses were modified by the anti-inflammatory drugs indomethacin, dexamethasone, colchicine and cyclophosphamide. The results of these experiments suggesting that the resting cell population of the pleural space contributed to the response, and that lysosomal enzyme release may play only a minor role in the mediation of increased vascular permeability.

Comparison of several activated partial thromboplastin time methods

Activated partial thromboplastin times (APTT's) performed with a semi-automated electrical-conductivity type of clot timer on plasmas from patients with hepatic disease and intravascular coagulation, and on warfarin or heparin therapy, were significantly lower than when done on the same plasmas with either a manual optical method or an automated optical-endpoint instrument. Results of APTT's done on normal plasmas by the three methods were not significantly different. Substitution of different activator-phospholipid reagents resulted in some variability in results, but these differences were less than those between the different done with both the electrical clot timer and the automated optical instrument on prepared plasmas containing 5.0 or 1.0% of factor II, V, VIII, IX, OR X revealed shorter times with the electrical clot timer only in the case of factor II- and factor V-deficient plasmas. APTT's done on normal plasmas to which 0.1 or 0.3 units per ml. of heparin had been added vitro also were shorter with the electrical clot itmer than the automatic optical instrument. Prothrombin times done on normal and abnormal control plasmas and on a series of plasmas from patients on warfarin therapy showed no significant difference between the two methods.