Glucocorticoids inhibit proliferation, cyclin D1 expression, and retinoblastoma protein phosphorylation, but not activity of the extracellular-regulated kinases in human cultured airway smooth muscle

We have previously shown that glucocorticoids inhibit mitogen-stimulated proliferation of human cultured airway smooth muscle (ASM) cells. The present study analyzed the effect of glucocorticoids on key regulatory pathways leading to passage of cells through the restriction point of the cell cycle, including those mediated by extracellular-regulated kinases (ERK) 1 and 2; the ERK upstream regulator MAPK kinase (MEK1); cyclin D1 levels; and levels and phosphorylation of retinoblastoma protein (pRb). Fluticasone propionate, a new inhaled glucocorticoid, was at least 10-fold more potent than dexamethasone in inhibiting thrombin-stimulated DNA synthesis and increases in cell number. Thrombin-stimulated increases in the levels and hyperphosphorylation of pRb were inhibited by glucocorticoids, which also reduced thrombin-stimulated cyclin D1 protein and messenger RNA (mRNA) levels. PD98059 (10 microM), an inhibitor of MEK1 activation, markedly attenuated thrombin stimulation of ERK activity and phosphorylation, DNA synthesis, and cyclin D1 levels. However, glucocorticoids had no effect on ERK activity or phosphorylation at 5 min, 2 h, or 12 h after addition of thrombin. In conclusion, glucocorticoid-induced reduction of cyclin D1 mRNA and protein levels, and of pRb phosphorylation, is sufficient to account for inhibition of ASM proliferation. Furthermore, these inhibitory effects of glucocorticoids on cyclin D1 and pRb occur on a component of the mitogen signaling cascade that is either downstream of or parallel to the ERK pathway.

The effect of glucocorticoids on proliferation of human cultured airway smooth muscle

1. Airway smooth muscle proliferation is a significant component of the airway wall remodelling that occurs in asthma. In this study, the effects of glucocorticoids on mitogenic responses of human airway smooth muscle have been examined. 2. Pretreatment of smooth muscle cells with dexamethasone (100 nM, 60 min) inhibited thrombin-induced increases in [3H]-thymidine incorporation (DNA synthesis) and cell number. 3. Inhibition of thrombin-induced [3H]-thymidine incorporation was also observed with hydrocortisone (0.01-1 microM) and methylprednisolone (0.001-0.1 microM) pretreatment. In contrast, pretreatment with either testosterone (0.001-1 microM) progesterone (0.001-1 microM), 17 beta-oestradiol (0.001-1 microM), or aldosterone (0.001-1 microM) had no effect on the response to thrombin. 4. Responses to a range of mitogens including thrombin (0.01-. 10 u ml-1), epidermal growth factor (EGF, 3-3000 pM), basic fibroblast growth factor (bFGF, 0.3-300 pM) and foetal calf serum (FCS, 0.1-10% v/v) were inhibited by dexamethasone (100 nM) pretreatment. However, the magnitude of the inhibitory effect was dependent on the mitogen, with EGF being the least, and thrombin being the most sensitive to the inhibitory effect. 5. The potency of hydrocortisone as an inhibitor of [3H]-thymidine incorporation was reduced when FCS (10% v/v, which caused a 40 fold increase in [3H]-thymidine incorporation) was used as the mitogen in place of thrombin (0.3 u ml-1, which caused a 10 fold increase in [3H]-thymidine incorporation). 6. The effect of post-treatment with dexamethasone (100 nM) indicated that addition of the glucocorticoid up to 17-19 h after thrombin (0.3 u ml-1) produced similar degrees of inhibition to those obtained when it was added as a pretreatment. Dexamethasone no longer produced an inhibitory effect if added 21 h or more after the addition of thrombin. 7. These results suggest that glucocorticoids regulate airway smooth muscle proliferation initiated by a range of stimuli. This effect may be of importance in the therapeutic actions of these compounds in asthma, particularly when they are used for prolonged periods of time.

Occurrence of filamentous fungi and yeasts in three different drinking water sources

In order to determine the occurrence of fungi in different drinking water sources and capture variability in terms of matrix composition and seasonal effects, surface water, spring water, and groundwater samples were collected in numerous sampling events. The occurrence and significance of fungi detected in the different water sources are reported and discussed in terms of colony-forming units per millilitre and by the identification of the most frequently detected isolates, at the species level, based on morphology and other phenotypic characters. All the samples were also analyzed in terms of total coliforms and Escherichia coli that are widely monitored bacteria considered as microbiology indicators of water quality. All the groundwater samples showed significantly lower levels of total coliforms, E. coli, and fungi compared to the surface and spring water samples. No significant correlations were found between the levels of fungi detected in all the matrices and the physico-chemical parameters and bacteria regularly monitored by drinking water utilities. Fifty-two fungi isolates were identified in this study, most of which have never been described to occur in water sources. The results obtained show that fungi occur widely in drinking water sources and that further studies should be conducted to address their biodegradation potential as well as if the drinking water treatment processes currently used are effective in removing these organisms and the potential secondary metabolites produced.

Apoptotic mimicry: phosphatidylserine liposomes reduce inflammation through activation of peroxisome proliferator-activated receptors (PPARs) in vivo

BACKGROUND AND PURPOSE

Recently, there has been much attention paid to understanding the molecular mechanisms underlying apoptosis and the functional consequences of apoptotic body clearance by phagocytes. In an attempt to investigate this latter aspect, the present study evaluated the anti-inflammatory effects of in vivo administration of phosphatidylserine (PS) liposomes, a well-characterised membrane component expressed during apoptosis. The participation of peroxisome proliferator-activated receptors (PPARs) in PS-mediated effects was also investigated.

EXPERIMENTAL APPROACH

The anti-inflammatory effect of PS liposomes on the delayed phase of carrageenan mouse paw oedema was studied. PS liposomes were injected at different doses and times, after carrageenan. Hind paws were collected for evaluation of interleukin-1beta (IL-1beta) levels, myeloperoxidase (MPO) and N-acetyl-glucosaminidase (NAG) activities and Evans blue dye leakage. Participation of PPAR pathways was explored by using PPAR antagonists (BADGE and GW9662).

KEY RESULTS

Administration of PS, but not phosphatidylcholine (PC), liposomes (20-200 mg kg(-1), i.p., 8 h after carrageenan) reduced the paw oedema in a dose-dependent manner. PS liposomes were effective even when administered 24 and 48 h after carrageenan, a time at which indomethacin (1 mg kg(-1), i.p.) had no significant effects. Carrageenan-induced Evans blue leakage and IL-1beta production was decreased in PS-treated paws. The PPAR antagonists (BADGE and GW9662) partially prevented the anti-inflammatory effects of PS administration.

CONCLUSIONS AND IMPLICATIONS

PS liposomes have anti-inflammatory effects in vivo that are at least partly dependent on PPAR activation. Therapeutic strategies mimicking apoptosis may be useful for the treatment of inflammatory disorders.

Assessment of the presence and dynamics of fungi in drinking water sources using cultural and molecular methods

A comparison of different isolation techniques and culture media for detection of filamentous fungi and yeasts in the aquatic environment revealed that the use of membrane filtration with the media dichloran rose bengal chloramphenicol (DRBC) optimized fungi detection in terms of abundance and variety in three untreated water sources with very different characteristics (surface water, spring water, and groundwater). The diversity of the fungi population captured by direct DNA extraction of fungi collected by membrane filtration was compared with the isolates obtained after selective growth using different culture media through amplification of the internal transcribed spacer gene and denaturing gradient gel electrophoresis (DGGE). The Czapek-Dox agar, Sabouraud dextrose agar, and DRBC media showed closer similarities to those obtained by the uncultured biomass for the different water sources. Based on these data and the best enumeration results, DRBC is recommended for the assessment of fungi in water sources using culture-based methods. DGGE was also used to monitor temporal variations in the fungal population structure and showed that each water matrix possessed a distinct population profile as well as that changes in the fungal community can be expected in the different matrices throughout the year.

Evaluation of micronuclei frequency in the cultured peripheral blood lymphocytes of cancer patients before and after radiation treatment

The frequency of micronucleated binucleate lymphocyte (MNBNC) was determined in the peripheral blood lymphocytes of patients suffering from various types of cancer before the onset of radiation treatment, middle (mid-) of the treatment and after completion of the treatment (post-treatment). The frequency of micronuclei increased significantly in the pretreatment sample of cancer patients when compared with the normal untreated healthy volunteers. During the middle of the radiotherapy an approximate two or > two-fold increase was observed in the micronuclei frequency in most of the patients when compared with the concurrent pretreatment samples. Immediately after the completion of treatment, the frequency of micronuclei further increased, and this increase was significantly higher than that of pretreatment and mid-treatment samples. Out of 27 patients analyzed, only nine patients did not have any history of smoking, tobacco chewing or alcohol consumption, while the remaining 18 patients had a history of either smoking, tobacco chewing or alcohol consumption or combination of two or all habits at the time of blood collection.

Repair of unilateral cleft lip: a comparison of five techniques

Repair of unilateral cleft lip is a challenging procedure with no single technique satisfactory for all types of unilateral cleft deformity. This study compares retrospectively five techniques of unilateral cleft lip repair in 72 children (45 boys, 27 girls). Twenty-two children had a Millard rotation-advancement repair, 5 children had a Davies Z-plasty, 22 had a modified Z-plasty, 10 had a Tennison-Randall triangular flap repair, and 13 had a Nakajima-Yoshimura straight-line repair. Assessment was performed clinically by a plastic surgeon not involved in the original surgery. Repairs were assessed objectively by measurement of the vertical length of both the repaired and normal sides of the lip with calipers. Subjective criteria used to evaluate the repair were the symmetry of Cupid's bow, the quality of scar, the alignment of white roll, the evenness of the vermilion, and the lip pout. The mean follow-up period was 5.4 years (range, 9 months-29 years). Sixty-five of the 72 repairs measured (90%) were within two standard deviations (SDs) of normal and thus were considered to be of "acceptable" length. Seven repairs were unacceptably short (>2 SDs) on measurement, six of which included a rotation-advancement repair for a complete cleft lip. Subjective results paralleled the objective results. The outcome following repair of unilateral cleft lip was similar for all five surgical methods assessed except for complete cleft lips repaired by the rotation-advancement technique, which tended to result in an unacceptably short lip as measured on the repaired side.

The Effect of Perioperative Ibuprofen Use on Tooth Sensitivity Caused by In-Office Bleaching

Objective:

This study determined the effect of the administration of perioperative ibuprofen 400 mg on tooth sensitivity caused by in-office bleaching.

Methods:

A triple-blind, parallel-design, randomized clinical trial was conducted on 30 adults who received placebo or ibuprofen before and after bleaching. The drugs were administered three times per day for 48 hours; the first dose was given one hour prior to the bleaching treatment. Two bleaching sessions with 35% hydrogen peroxide gel were performed with a one-week interval. Tooth sensitivity was recorded on two scales: visual analogue and five-point verbal rating scale up to 48 hours after bleaching. The shade evaluation was performed with a visual shade guide and spectrophotometer, before and 30 days after bleaching. The absolute risk of tooth sensitivity and its intensity were evaluated by Fisher exact and Mann-Whitney tests, respectively. The shade changes were evaluated by Student's t-test.

Results:

Both groups showed similar absolute risk of tooth sensitivity (p>0.05). Lower tooth sensitivity was observed in the experimental group only up to one hour postbleaching (p=0.04). Similar tooth sensitivity was observed in the other periods of time.

Conclusion:

The perioperative use of the anti-inflammatory ibuprofen was not able to avoid tooth sensitivity but reduced its intensity up to one hour after bleaching.

Simultaneous determination of lidocaine, prilocaine and the prilocaine metabolite o-toluidine in plasma by high-performance liquid chromatography

An HPLC assay is described for the measurement of prilocaine and lidocaine (components of the local anesthetic cream EMLA) as well as the prilocaine metabolite, o-toluidine, in plasma. The method uses UV detection, is simple, sensitive and most important, only a single 200-microliters plasma sample is needed for simultaneous analysis of prilocaine, lidocaine and o-toluidine with a detection limit of 4 ng/ml. The plasma, together with the internal standard (bupivacaine) is extracted with diethyl ether under alkaline conditions, followed by the extraction of the analytes from the organic phase into dilute sulphuric acid. An aliquot of the acid extract is injected onto the HPLC system and the effluent is monitored by a UV detector.

Amifostine protects normal tissues from paclitaxel toxicity while cytotoxicity against tumour cells is maintained

The objectives of this study were to evaluate the protective effects of amifostine against paclitaxel-induced toxicity to normal and malignant human tissues. Haematopoietic progenitor colony assays were used to establish the number of CFU-GEMM and BFU-E colonies after incubation with WR-1065 alone, Amifostine alone, paclitaxel (2.5 or 5 microM) +/- WR-1065 or amifostine. MTT and alkaline elution assays evaluated the in vitro growth inhibitory and DNA damaging effects, respectively, of paclitaxel with or without amifostine against normal human fibroblasts and human non-small cell lung cancer (NSCLC) cells. This combination was also evaluated in vivo using severe combined immune deficient (scid) mouse models of early (non-palpable tumours) and advanced (palpable tumours) human ovarian cancer. Human 2780 ovarian cancer cells were inoculated subcutaneously while paclitaxel and amifostine were administered intraperitoneally. A brief exposure (15 min) to amifostine not only protected human haematopoietic progenitor colonies from paclitaxel toxicity, but stimulated the growth of CFU-GEMM and BFU-E beyond control values. Amifostine protected normal human lung fibroblasts from paclitaxel-induced cytotoxicity and DNA single-strand breaks. However, paclitaxel cytotoxicity and DNA single-strand breaks were actually enhanced by pretreatment with amifostine in the NSCLC model. Importantly, amifostine did not interfere with paclitaxel antitumour activity even with prolonged exposure (24.5 h) of the lung cancer cells to high concentrations (1.2 mM) in vitro or following five repetitive high doses (200 mg/kg) given to scid mice with human ovarian cancer xenografts. Indeed, under certain circumstances, amifostine resulted in sensitisation of tumour cells to paclitaxel. Our results confirm previous reports of the ability of amifostine to protect normal tissues from the toxic effects of chemotherapy drugs and now extend these observations to paclitaxel.

Administration of Ascorbic Acid to Prevent Bleaching-induced Tooth Sensitivity: A Randomized Triple-blind Clinical Trial

This study evaluated the effect of ascorbic acid, 500 mg every eight hours, on bleaching-induced tooth sensitivity. A triple-blind, parallel design, and placebo-controlled randomized clinical trial was conducted on 39 adults. The pills (placebo or ascorbic acid) were administered three times per day for 48 hours; the first dose was given one hour prior to each bleaching session. Two bleaching sessions with 35% hydrogen peroxide gel were performed with a one-week interval. Tooth sensitivity was recorded up to 48 hours after bleaching. The color evaluation was performed before and 30 days after bleaching. The absolute risk and intensity of tooth sensitivity were evaluated by Fisher exact and Mann-Whitney U-tests, respectively. Color changes were evaluated by unpaired t-test (α=0.05). There were no significant differences in the absolute risk and intensity of tooth sensitivity and color change between the groups. Both groups showed a similar risk of tooth sensitivity (p>0.05). The perioperative use of an antioxidant, such as ascorbic acid (500 mg, three times daily) perorally, was not able to prevent bleaching-induced tooth sensitivity or reduce its intensity.

Percutaneous and limited open reduction of intra-articular distal radial fractures

Fluoroscopy monitors intra-articular distal radial fracture reduction and stabilisation. The reduction is guided by traction, ligamentotaxis and manipulation, and when necessary, completed by minimally invasive percutaneous or limited open instrumentation. Kirschner wires effectively splint the reduction until fracture callus is visualised on X-ray. An occasional mini plate is required to buttress a displaced volar medial lunate facet (die punch) fragment into position. First, major metaphyseal articular fragments are approximated to restore the articular surface. Smaller fragments follow their larger counterparts into position or may be ignored (the "Rule of the Majority" or "Vassal Rule"). The repaired metaphysis is then aligned with and stabilised to the diaphysis. Cancellous bone may be inserted through small targeted incisions when defects and areas of comminution are present. The wrist is splinted in a functional (slightly extended) position for three to four weeks in uncomplicated cases. Digital elevation and rehabilitation are emphasised during the early stages of fracture healing. After callus appears on X-ray, progressive wrist rehabilitation is initiated and the patients are weaned from their splints. Minimally invasive surgical intervention, good pain control and early rehabilitation maximise functional recovery and minimise morbidity, medical costs and lost work time.

Evaluating the impact of sprouting conditions on the glucosinolate content of Brassica oleracea sprouts

The glucosinolates content of brassica plants is a distinctive characteristic, representing a healthy advantage as many of these compounds are associated to antioxidant and anti-carcinogenic properties. Brassica sprouts are still an underutilized source of these bioactive compounds. In this work, four varieties of brassica sprouts (red cabbage, broccoli, Galega kale and Penca cabbage), including two local varieties from the North of Portugal, were grown to evaluate the glucosinolate profile and myrosinase activity during the sprouting. Also the influence of light/darkness exposure during sprouting on the glucosinolate content was assessed. Glucosinolate content and myrosinase activity of the sprouts was evaluated by HPLC methods. All sprouts revealed a higher content of aliphatic glucosinolates than of indole glucosinolates, contrary to the profile described for most of brassica mature plants. Galega kale sprouts had the highest glucosinolate content, mainly sinigrin and glucoiberin, which are recognized for their beneficial health effects. Penca cabbage sprouts were particularly richer in glucoraphanin, who was also one of the major compounds in broccoli sprouts. Red cabbage showed a higher content of progoitrin. Regarding myrosinase activity, Galega kale sprouts showed the highest values, revealing that the use of light/dark cycles and a sprouting phase of 7-9 days could be beneficial to preserve the glucosinolate content of this variety.

PPARγ expression is increased in systemic lupus erythematosus patients and represses CD40/CD40L signaling pathway

Systemic lupus erythematosus (SLE) is a heterogeneous disease involving several immune cell types and pro-inflammatory signals, including the one triggered by binding of CD40L to the receptor CD40. Peroxisome-proliferator activated receptor gamma (PPARγ) is a transcription factor with anti-inflammatory properties. Here we investigated whether CD40 and PPARγ could exert opposite effects in the immune response and the possible implications for SLE. Increased PPARγ mRNA levels were detected by real-time PCR in patients with active SLE, compared to patients with inactive SLE PPARγ/GAPDH mRNA = 2.21 ± 0.49 vs. 0.57 ± 0.14, respectively (p < 0.05) or patients with infectious diseases and healthy subjects (p < 0.05). This finding was independent of the corticosteroid therapy. We further explored these observations in human THP1 and in SLE patient-derived macrophages, where activation of CD40 by CD40L promoted augmented PPARγ gene transcription compared to non-stimulated cells (PPARγ/GAPDH mRNA = 1.14 ± 0.38 vs. 0.14 ± 0.01, respectively; p < 0.05). This phenomenon occurred specifically upon CD40 activation, since lipopolysaccharide treatment did not induce a similar response. In addition, increased activity of PPARγ was also detected after CD40 activation, since higher PPARγ-dependent transcription of CD36 transcription was observed. Furthermore, CD40L-stimulated transcription of CD80 gene was elevated in cells treated with PPARγ-specific small interfering RNA (small interfering RNA, siRNA) compared to cells treated with CD40L alone (CD80/GAPDH mRNA = 0.11 ± 0.04 vs. 0.05 ± 0.02, respectively; p < 0.05), suggesting a regulatory role for PPARγ on the CD40/CD40L pathway. Altogether, our findings outline a novel mechanism through which PPARγ regulates the inflammatory signal initiated by activation of CD40, with important implications for the understanding of immunological mechanisms underlying SLE and the development of new treatment strategies.

Tolfenamic acid decreases migraine recurrence when used with sumatriptan

Although sumatriptan is an effective drug for the treatment of acute migraine attacks, recurrence has been cited as an important limitation for its use. Tolfenamic acid is also effective in the acute treatment of migraine attacks. We studied the recurrence rate of migraine attacks with the use of sumatriptan plus tolfenamic acid among patients who presented frequent recurrence with sumatriptan. Fifty migraineurs were retrospectively studied, all having treated at least 10 attacks with 100 mg P.O.; sumatriptan was effective in at least eight of them. The patients also presented recurrence in less than 24 h in at least five of the treated attacks. We then used sumatriptan 100 mg plus tolfenamic acid 200 mg P.O. during the first 60 min of the attack; 240 attacks were treated and there was recurrence in 57 (23.8%). With sumatriptan alone, 5 out of 8 attacks (62.5%) presented recurrence. We therefore conclude that the combination sumatritpan plus tolfenamic acid is effective in reducing the recurrence rate from 5 of 8 (62.5%) to 1.19 of 5 (23.8%). Further prospective studies with a double-blind design and a higher number of treated attacks are necessary to confirm these initial observations.

Early potassium channel blockade improves sepsis-induced organ damage and cardiovascular dysfunction

BACKGROUND AND PURPOSE

There is increasing evidence that potassium channels are involved in the cardiovascular dysfunction of sepsis. This evidence was obtained after the systemic inflammation, cardiovascular dysfunction and organ damage had developed. Here we have studied the consequences of early interference with potassium channels on development of sepsis.

EXPERIMENTAL APPROACH

Sepsis was induced by caecal ligation and puncture (CLP) or sham surgery in Wistar rats. Four hours after surgery, animals received tetraethylammonium (TEA; a non-selective potassium channel blocker) or glibenclamide (a selective ATP-sensitive potassium channel blocker). Twenty-four hours after surgery, inflammatory, biochemical, haemodynamic parameters and survival were evaluated.

KEY RESULTS

Sepsis significantly increased plasma NO(x) levels, expression of inducible nitric oxide synthase (NOS-2) protein in lung and thigh skeletal muscle, lung myeloperoxidase, urea, creatinine and lactate levels, TNF-α and IL-1β, hypotension and hyporesponsiveness to phenylephrine and hyperglycemia followed by hypoglycemia. TEA injected 4 h after surgery attenuated the increased NOS-2 expression, reduced plasma NO(x) , lung myeloperoxidase activity, levels of TNF-α and IL-1β, urea, creatinine and lactate levels, prevented development of hypotension and hyporesponsiveness to phenylephrine, the alterations in plasma glucose and reduced late mortality by 50%. Glibenclamide did not improve any of the measured parameters and increased mortality rate, probably due to worsening the hypoglycemic phase of sepsis.

CONCLUSIONS AND IMPLICATIONS

Early blockade of TEA-sensitive (but not the ATP-sensitive subtype) potassium channels reduced organ damage and mortality in experimental sepsis. This beneficial effect seems to be, at least in part, due to reduction in NOS-2 expression.

Neuroanatomy and behavior in mice with a haploinsufficiency of AT-rich interactive domain 1B (ARID1B) throughout development

BACKGROUND

One of the causal mechanisms underlying neurodevelopmental disorders (NDDs) is chromatin modification and the genes that regulate chromatin. AT-rich interactive domain 1B (ARID1B), a chromatin modifier, has been linked to autism spectrum disorder and to affect rare and inherited genetic variation in a broad set of NDDs.

METHODS

A novel preclinical mouse model of Arid1b deficiency was created and validated to characterize and define neuroanatomical, behavioral and transcriptional phenotypes. Neuroanatomy was assessed ex vivo in adult animals and in vivo longitudinally from birth to adulthood. Behavioral testing was also performed throughout development and tested all aspects of motor, learning, sociability, repetitive behaviors, seizure susceptibility, and general milestones delays.

RESULTS

We validated decreased Arid1b mRNA and protein in Arid1b+/- mice, with signatures of increased axonal and synaptic gene expression, decreased transcriptional regulator and RNA processing expression in adult Arid1b+/- cerebellum. During neonatal development, Arid1b+/- mice exhibited robust impairments in ultrasonic vocalizations (USVs) and metrics of developmental growth. In addition, a striking sex effect was observed neuroanatomically throughout development. Behaviorally, as adults, Arid1b+/- mice showed low motor skills in open field exploration and normal three-chambered approach. Arid1b+/- mice had learning and memory deficits in novel object recognition but not in visual discrimination and reversal touchscreen tasks. Social interactions in the male-female social dyad with USVs revealed social deficits on some but not all parameters. No repetitive behaviors were observed. Brains of adult Arid1b+/- mice had a smaller cerebellum and a larger hippocampus and corpus callosum. The corpus callosum increase seen here contrasts previous reports which highlight losses in corpus callosum volume in mice and humans.

LIMITATIONS

The behavior and neuroimaging analyses were done on separate cohorts of mice, which did not allow a direct correlation between the imaging and behavioral findings, and the transcriptomic analysis was exploratory, with no validation of altered expression beyond Arid1b.

CONCLUSIONS

This study represents a full validation and investigation of a novel model of Arid1b+/- haploinsufficiency throughout development and highlights the importance of examining both sexes throughout development in NDDs.

Kallikrein-kinin system activation by Lonomia obliqua caterpillar bristles: involvement in edema and hypotension responses to envenomation

Lonomia obliqua envenomation induces an intense burning sensation at the site of contact and severe hemorrhage followed by edema and hypotension, and after few days death can occur usually due to acute renal failure. In order to understand more about the envenomation syndrome, the present study investigates the role played by kallikrein-kinin system (KKS) in edematogenic and hypotensive responses to the envenomation by L. obliqua. The incubation of L. obliqua caterpillar bristles extract (LOCBE) with plasma results in kallikrein activation, measured by cromogenic assay using the kallikrein synthetic substrate S-2302 (H-D-Pro-Phe-Arg-pNA). It was also showed that LOCBE was able to release kinins from low-molecular weight kininogen (LMWK). Moreover, it was demonstrated that previous administration of a kallikrein inhibitor (aprotinin) or bradykinin B2 receptor antagonist (HOE-140) significantly reduces the edema and hypotension in response to LOCBE, using mouse paw edema bioassay and mean arterial blood pressure analysis, respectively. The results demonstrate a direct involvement of the KKS in the edema formation and in the fall of arterial pressure that occur in the L. obliqua envenomation syndrome.

Nitric oxide-induced inhibition of mouse paw edema: involvement of soluble guanylate cyclase and potassium channels

OBJECTIVE AND DESIGN

To investigate the effect of nitric oxide (NO) donors on inflammatory mouse paw edema (MPE).

MATERIALS AND METHODS

Mice previously treated with sodium nitroprusside (SNP; 1.5, 5 and 10 micromol/kg) or S-nitroso-N-acetyl-DL-penicillamine (SNAP; 7, 14 and 28 micromol/kg) were injected with inflammatory mediators in the paw. Paw edema, myeloperoxidase activity and vascular dye leakage were measured.

RESULTS

Pre-treatment with SNP and SNAP (4 h or 12 h) reduced (approximately 50%) MPE induced by carrageenan, dextran sulfate, bradykinin and histamine but not by serotonin. Pre-treatment with SNP also inhibited carrageenan-induced increases in myeloperoxidase activity and vascular dye leakage. Methylene blue blocked the SNP-induced reduction in MPE when injected 30 min before or 2 h after SNP, but not 4 or 6 h after the NO donor. Tetraethylammonium blocked the SNP-induced reduction in MPE if injected 30 min before or 2, 4 or 6 h after SNP.

CONCLUSIONS

NO donors have a long-lasting anti-inflammatory effect in MPE, which involves guanylate cyclase and tetraethylammonium-sensitive potassium channels.

Urinary iron excretion depends on the mode of administration of the oral iron chelator 1,2-dimethyl-3-hydroxypyrid-4-one in patients with homozygous beta-thalassemia

OBJECTIVE

To examine the effect of frequency of oral administration of 1,2-dimethyl-3-hydroxypyrid-4-one (L1) on urinary iron excretion.

HYPOTHESIS

Sustained serum concentrations of L1 will cause more iron chelation than the same daily dose given in larger but less frequent amounts.

PATIENTS AND METHODS

Ten patients with thalassemia with a mean age of 20.9 +/- 4.7 years (range, 13 to 27 years), who were receiving regular treatment with 75 to 100 mg/kg/day oral L1, received 75 mg/kg/day L1 orally in equally divided doses: every 6 hours for 3 days and every 12 hours for 3 days. The two study periods occurred 1 month apart immediately after the monthly blood transfusions. Urine was collected for two consecutive 24-hour periods during each of the different schedules. Serial blood samples were collected from six patients over a 6-hour period and analyzed for total L1 and the L1 glucuronide metabolite concentrations.

RESULTS

The patient's mean hemoglobin levels (138.8 +/- 12.5 and 139.0 +/- 11.6 gm/L) and ferritin levels (2856.4 +/- 2207.8 and 2890.0 +/- 2264.4 micrograms/L) were similar during the every-6-hour and every-12-hour L1 administrations, respectively. There was significantly more urinary iron excretion when L1 was administered every 6 hours (0.59 +/- 0.29 mg/kg/day) versus every 12 hours (0.40 +/- 0.26 mg/kg/day; p = 0.0129). Calculated 24-hour area under the plasma concentration-time curve of L1 was similar during the every-6-hour (7023.9 +/- 2637.8 mg.min/L) and every-12-hour (7050.1 +/- 1668.8 mg.min/L) experiments.

CONCLUSIONS

These data suggest that the sustained presence of L1 in the blood results in greater chelation of iron than that observed with larger, less frequent doses.

Acute bacterial meningitis in the intensive care unit and risk factors for adverse clinical outcomes: retrospective study

BACKGROUND

Bacterial meningitis constitutes a medical emergency. Its burden has driven from childhood to the elderly and the immunocompromised population. However, the admission of patients with bacterial meningitis to the intensive care unit (ICU) has been sparsely approached, as have the prognostic factors associated with an adverse clinical outcome.

METHODS

We performed a retrospective analysis during a 7-year period of patients older than 18 years admitted to 2 polyvalent ICUs. Clinical, demographic, and outcome data were collected to evaluate its clinical impact on the outcome of patients with acute bacterial meningitis.

RESULTS

We identified 65 patients with the diagnosis of acute bacterial meningitis (mean Acute Physiology and Chronic Health Evaluation II, 23; hospital mortality, 40%). Upon clinical presentation, their most frequent signs were fever (84%), seizures (21.5%), and a low Glasgow Coma Scale (GCS) score (GCS<8; 58.4%). Fifty-five patients (85%) required organ support. A definite microbiological diagnosis was achieved in 45 patients. An adverse clinical outcome was noted in 46 patients (71%). These patients were older (P=.005), had higher Physiology and Chronic Health Evaluation II score (P=.022), and had lower GCS (P=.022). In the multivariate analysis, older age (per year; adjusted odds ratio [aOR], 1.059) was associated with an adverse outcome, whereas a higher GCS (per point; aOR, 0.826) and presence of fever upon admission (aOR, 0.142) increase the chance of a good recovery.

CONCLUSIONS

Patients with acute bacterial meningitis admitted to ICU had substantial morbidity and mortality. Those with low GCS or absence of fever have a particularly high risk of an adverse outcome.

The impact of glycemic variability on length of stay and mortality in diabetic patients admitted with community-acquired pneumonia or chronic obstructive pulmonary disease

AIM

To investigate the influence of glycemic variability (GV) on length of stay and in-hospital mortality in non-critical diabetic patients.

METHODS

A observation retrospective study was performed. Diabetic patients admitted between January and June 2016 with the diagnosis of community-acquire pneumonia (CAP) and/or acute exacerbation of chronic obstructive pulmonary disease (COPD) were enrolled and glycemic control (persistent hyperglycemia, hypoglycemia, mean glucose level (MGL) and respective standard deviation (SD) and coefficient of variation (CV)) were evaluated. Primary outcomes were length of stay and in-hospital mortality.

RESULTS

Data from 242 patients were analyzed. Fifty-eight percent of the patients were male, with a median age of 77 years (min-max, 29-98). Patients had on average 2.1 glucose readings-day and the MGL was 193.3 mg/dl (min-max, 84.3-436.6). Hypoglycemia was documented in 13.4% of the patients and 55.4% had persistent hyperglycemia. The median length of hospital stay was 10 days (min-max, 1-66) and in-hospital mortality was 7.4%. We found a significant higher in-hospital mortality in older patients, with history of cancer and with nosocomial infections. We did not find any correlation between MGL, SD, CV, hypoglycemia or persist hyperglycemia and in-hospital mortality. A longer length of stay was observed in patients with heavy alcohol consumption and nosocomial infections. The length of stay was negatively correlated with the mean glucose level (r²-0.147; p < 0.05) and positively correlated with the coefficient of variation (p 0.162; p < 0.05).

CONCLUSION

This study confirmed the negative impact of the glycemic variability in the outcomes of diabetic patients admitted with CAP or acute exacerbation of COPD.