Wind variability in a coastal area (Alfacs Bay, Ebro River delta)

Abstract. Wind spatial heterogeneity in a coastal area (Alfacs Bay, northwestern Mediterranean Sea) is described using a set of observations and modelling results. Observations in three meteorological stations (during 2012–2013) along the coastline reveal that wind from the N–NW (strongest winds in the region) appears to be affected by the local orography promoting high wind variability on relatively short spatial scales (of the order of few kilometres). On the other hand, sea breezes in late spring and summer also show noticeable differences in both spatial distribution and duration. The importance of wind models' spatial resolution is also assessed, revealing that high resolution (= 3 km) substantially improves the results in comparison to coarse resolution (9 km). The highest-resolution model tested (400 m) also presents noticeable improvements during some events, showing spatial variability not revealed by coarser models. All these models are used to describe and understand the spatial variability of the typical wind events in the region. The results presented in this contribution should be considered on hydrodynamic, ecological and risk management investigations in coastal areas with complex orography.

Subcutaneous nodules in Whipple's disease

BACKGROUND

Cutaneous findings other than hyperpigmentation are rare in Whipple's disease.

CASE REPORT

We present the case of a 59-year-old man previously diagnosed with Whipple's disease by duodenal biopsy, who developed red-brown, painful, subcutaneous nodules on the buttocks, thighs, arms and legs. Biopsy of these nodules showed a septal panniculitis and foamy macrophages containing PAS-positive, diastase resistant intracytoplasmic material, characteristic of Whipple's disease and similar to that observed in the duodenal biopsy. Ultrastructurally, this material in the histiocytes corresponded to degenerated bacilli.

CONCLUSIONS

This is the fourth documented case of subcutaneous involvement by Whipple's disease. One should consider the possibility of Whipple's disease in any patient who presents with symptoms compatible with that condition who demonstrates septal panniculitis with a large amount of foamy histiocytes.

Inflammatory neutrophils secrete annexin 1 during experimentally induced colitis in rats

Immunoblotting and immunohistochemical analysis were performed to identify the cells expressing and secreting annexin 1 during experimental rat colitis induced by trinitrobenzene sulfonic acid. Annexin 1 expression was increased during the inflammation. Likewise, annexin 1 secretion was induced in inflamed colons at one, three, six, and nine days after trinitrobenzene sulfonic acid treatment but was not detected in colons from controls and rats at 12 days. Immunohistochemistry showed that the rise in annexin 1 expression resulted from the infiltration of two types of leukocytes highly positive for annexin 1: neutrophils (the most abundant) and macrophages. At day 1 after treatment, neutrophils of the inflammatory site, in mucosa and submucosa, are the only cells expressing annexin 1. Immunoblotting showed that they secreted annexin 1 whereas neutrophils from blood or tunica muscularis did not. This indicates that, during this colitis, annexin 1 can be secreted by neutrophils located in the inflammatory site.

Role of kinin B1 and B2 receptors and mast cells in post intestinal infection-induced hypersensitivity to distension

Distension of the rat intestine causes a capsaicin-sensitive, pressure-dependent depressor response which is indicative of nociception. A hypersensitivity of jejunal distension which possibly involves tachykinin NK2 receptors and is restricted to areas with mast cell hyperplagia is observed in rats infected 30 days previously with Nippostrongylus brasiliensis. This study aimed to further investigate the role of mast cells, tachykinins and kinins in this intestinal hypersensitivity. The activity of a mast cell stabilizer (doxantrazole), kinin antagonists (des-Arg 10-[Leu9]-kallidin, B1, HOE 140, B2) and tachykinin antagonists (CP 99, 994, NK1, SR 142801, NK3) were tested against the distension-induced depressor responses in control and post-infected rats. The 30-day post-infection-induced hypersensitivity was significantly reduced by the mast cell stabilizer doxantrazole. The hypersensitivity had resolved in 90-day post-infected rats when mast cells levels had normalized. Des-Arg 10-[Leu9]-kallidin and HOE 140 did not inhibit the depressor responses in controls but produced a significant inhibition in 30-day post-infected rats. CP 99,994 inhibited the depressor responses in post-infected rats with an equal potency to that in control rats. SR 142801 was inactive in both groups. In conclusion, mast cells and kinin-mediated nociception appear to be involved in post-infection intestinal hypersensitivity whereas tachykinin NK1 and NK3 receptors do not.

Peroxisome proliferator-activated receptor alpha-isoform deficiency leads to progressive dyslipidemia with sexually dimorphic obesity and steatosis

The alpha-isoform of the peroxisome proliferator-activated receptor (PPARalpha) is a nuclear transcription factor activated by structurally diverse chemicals referred to as peroxisome proliferators. Activators can be endogenous molecules (fatty acids/steroids) or xenobiotics (fibrate lipid-lowering drugs). Upon pharmacological activation, PPARalpha modulates target genes encoding lipid metabolism enzymes, lipid transporters, or apolipoproteins, suggesting a role in lipid homeostasis. Transgenic mice deficient in PPARalpha were shown to lack hepatic peroxisomal proliferation and have an impaired expression and induction of several hepatic target genes. Young adult males show hypercholesterolemia but normal triglycerides. Using a long term experimental set up, we identified these mice as a model of monogenic, spontaneous, late onset obesity with stable caloric intake and a marked sexual dimorphism. Serum triglycerides, elevated in aged animals, are higher in females that develop a more pronounced obesity than males. The latter show a marked and original centrilobular-restricted steatosis and a delayed occurrence of obesity. Fat cells from their liver express substantial levels of PPARgamma2 transcripts when compared with lean cells. These studies demonstrate, in rodents, the involvement of PPARalpha nuclear receptor in lipid homeostasis, with a sexually dimorphic control of circulating lipids, fat storage, and obesity. Characterization of this pathological link may help to delineate new molecular targets for therapeutic intervention and could lead to new insights into the etiology and heritability of mammalian obesity.

Effects of nematode infection on sensitivity to intestinal distension: role of tachykinin NK2 receptors

Distension of the rat intestine causes a depressor response which is predictive of nociception. This study investigated the effects of previous infection with Nippostrongylus (N.) brasiliensis on the sensitivity to intestinal distension and the role of tachykinin NK2 receptors. The tachykinin NK2 receptor antagonist, SR48968 (S)-N-methyl-N[4-(4-acetylamino-4-phenylpiperidino)-2-(3,4-dichloropheny l)butyl]benzamide) inhibited the nociceptive response (ED50 = 0.7 mg/kg) in control rats. In post-N. brasiliensis-infected rats sensitivity to intestinal distension was increased which was accompanied by an increase in the apparent potency value of SR48968 (ED50 = 0.1 mg/kg). The hypersensitivity was limited to areas of hypermastocytosis. It is concluded that the post-inflammatory changes that occur in post-infected rats increase visceral sensitivity and the apparent potency of tachykinin NK2 receptor antagonists.

Expression and secretion of lipocortin 1 in gut inflammation are not regulated by pituitary-adrenal axis

Lipocortin 1 is considered a mediator of the anti-inflammatory actions of glucocorticoids. We have shown that this protein is overexpressed and secreted during an experimental colitis induced by intraluminal injection of trinitrobenzenesulfonic acid (TNBS) in rats. We studied here the in vivo regulation of lipocortin 1 expression and secretion in this model, either by glucocorticoids using adrenalectomized or dexamethasone-treated (3 mg/24 h) animals or by pituitary factors using hypophysectomized animals. Inflammation was evaluated by measuring myeloperoxidase activity and by histological scoring of the damage. Lipocortin 1 was detected by immunoblotting, and its secretion was studied by incubating colonic specimens in-culture medium. In the colon of TNBS-injected animals, cumulative histological damage scores were increased in adrenalectomized and decreased in dexamethasone-treated animals compared with control and hypophysectomized animals. The colons of all TNBS-injected animals (controls, adrenalectomized, dexamethasone treated, hypophysectomized) overexpressed and secreted lipocortin 1. In conclusion, the induction of lipocortin 1 overexpression and secretion during this colitis occurs independently of glucocorticoids or pituitary factors.

Epidemiology of an unusually prolonged outbreak of typhoid fever in Terrassa, Spain

An unusually prolonged outbreak of typhoid fever, from 1988 to 1994, in Terrassa (Barcelona, Spain), was caused by a casual food handler who was a carrier. The pattern of this outbreak suggested intermittent low-level exposure to Salmonella typhi. We found 70 patients with S. typhi infections, 52 of whom were available for study. Medical records were reviewed and patients were interviewed with use of a standard questionnaire. Phage typing and pulsed-field gel electrophoresis (PFGE) for strain subtyping were used to confirm the epidemiological data. The 27 outbreak strains shared the same phage type and the same PFGE pattern. Four sporadic strains shared the same phage type as the outbreak strain. PFGE was found to be useful for differentiating strains for epidemiological purposes.

Stress-induced enhancement of colitis in rats: CRF and arginine vasopressin are not involved

Because exacerbation of colitis seems to be associated with stress, we proposed evaluating the influence of stress and the involvement of corticotropin-releasing factor (CRF) and arginine vasopressin (AVP) on experimental colitis in rats. Partial restraint stress was applied during 4 consecutive days, before or after intracolonic 2,4,6-trinitrobenzenesulfonic acid (TNB) instillation (15 mg) in rats. Finally, two groups of rats were centrally injected with alpha-helical CRF-(9-41) (5 micrograms) or AVP antagonist (5 micrograms) before each session of stress. Stress was applied before or right after TNB enhanced colitis, with an increase in macroscopic and histological scores and myeloperoxidase activity, alpha-Helical CRF-(9-41) or AVP antagonist had no effect on TNB-induced colitis but enhanced the effects of stress on colitis. These results show that stress may exacerbate experimental colitis in rats and that CRF and AVP are not responsible for this effect.

Histochemical study of cutaneous mucins in hypothyroid dogs

A dermal mucinosis, visualized as dermal alcianophilic material, is occasionally present in canine hypothyroidism (myxedema). Various histochemical reactions (alcian blue/periodic acid-Schiff [PAS], alcian blue at pH 2.6, alcian blue at pH 1.0, critical electrolytical concentrations with and without dimethylsulfoxide, differential hydrolysis by hyaluronidases) were performed on skin biopsies from six dogs (four females and two males ranging from 8 to 13 years) affected by hypothyroidism, all of them presenting dermal mucinosis in hematoxylin and eosin-stained sections. In these dogs, the only polysaccharidic compound involved in the dermal mucinosis was hyaluronic acid. In this study, hyaluronic acid dermal deposits of hypothyroid dogs were significantly different from those of controls in subepidermal connective tissue and loose reticular connective tissue but not in periadnexal zones. We recommend the combined alcian blue/PAS reaction as a routine technique to assess dermal mucinosis in hypothyroid dogs.

Inverse regulation of alpha- and beta-adrenoceptors during trinitrobenzenesulfonic acid (TNB)-induced inflammation in guinea-pig small intestine

The hypothesis has been raised that intestinal motor disturbances induced by inflammation of the digestive tract may reflect alterations in intestinal cell-membrane receptors. This question has been addressed herein for adrenoceptors by performing [3H]prazosin, [3H]rauwolscine and [3H]DHA binding studies on guinea-pig jejunal smooth-muscle membrane preparations from both healthy controls and 3, 6, and 10 days after TNB-induced intestinal inflammation. Each of the adrenoceptor subtype-selective radioligands used bound selectively to a single saturable class of sites, with no significant (p < 0.05) variation of dissociation constant (KD) values along the inflammatory process. In contrast maximal binding capacities (Bmax) for the different radioligands varied moderately but significantly (p < 0.05 and p < 0.01) according to the time after TNB injection. The alpha-adrenoceptors were significantly upregulated, respectively from (mean +/- SE in fmoles/mg of proteins) 27 +/- 3.8 (controls) to 91 +/- 3.1 (day 10) for the alpha 1-subtype, and from 26 +/- 2.7 (controls) to 102 +/- 5.9 (day 10) for the alpha 2-subtype. In contrast beta-adrenoceptors were down-regulated from 384 +/- 34.6 (controls) to 158 +/- 17.2 (day 10). These findings highlighted an apparently inverse pathological regulation of intestinal alpha- and beta- adrenoceptor densities. They suggest that changes in intestinal adrenoceptors, probably resulting from functional denervation of the inflamed bowel tissue, may contribute to the altered intestinal motility observed in inflammatory bowel diseases.

Effect of low doses of a trichothecene mycotoxin (diacetoxyscirpenol) on rat gastric glycoproteins: a histochemical study

A histochemical study was carried out to evaluate the changes occurring in the glycoproteins of the stomach of the rat following short-term treatment with the trichothecene mycotoxin, diacetoxyscirpenol (DAS). Staining with alcian blue methods for detecting complex carbohydrates and with lectin conjugates (Con A, LTA, PNA, SBA and WGA) showed an increased alcianophilia at pH 2.6 and pH 1.0 for various parts of the fundic glands. With respect to lectin staining, DAS intoxication was characterized by enhanced labelling with LTA and SBA in the surface epithelium and in the foveolae, while WGA binding appeared in the lower mucous neck cells. These data suggest that the contents of the mucus-producing cells of the fundic glands of the rat stomach could be affected by low doses of diacetoxyscirpenol even following only 2 days of treatment.

[Heparin-induced skin necrosis, thrombocytopenia and pulmonary thromboembolism. Presentation of 2 cases]

Two patients with skin necrosis in the injection points after subcutaneous prophylactic porcine calcium heparin administration are reported. In addition, both patients had thrombopenia, deep venous thrombosis and pulmonary thromboembolism. The review of similar cases suggests that skin necrosis is another feature of the thrombopenia and multiple vascular thrombosis syndrome associated with heparin administration. Data from the literature suggest that there is a common immunologically-mediated pathogenetic mechanism responsible for these phenomena through the production of platelet aggregates and immune reaction in endothelial cells. Paradoxically, the continuation of therapy with intravenous sodium heparin was not followed in our patients by new complications despite the theoretical risk.

Effects of treatment with smectite on gastric and intestinal glycoproteins in the rat: a histochemical study

A histochemical study was carried out to evaluate the changes that occur in the glycoproteins of the rat digestive tract following short term treatment with a clay smectite. Staining with the usual methods for detecting complex carbohydrates and with lectin conjugates (Con A, LTA, PNA, SBA and WGA) showed that the stomach was the susceptible organ. Increased staining with LTA and SBA, together with a decrease in the abundance of sulphate groups in the upper mucous neck cells, was observed after the clay treatment. Such treatment induced only slight changes in jejunal and colonic glycoproteins while no modification was observed in the colon. These data suggest that the content of mucus-producing cells could be affected by smectite, even following short-term treatment.

Histochemical characterization of glycoproteins present in jejunal and colonic goblet cells of pigs on different diets. A biopsy study using chemical methods and peroxidase-labelled lectins

We examined the glycoprotein composition of intestinal goblet cells in jejunal and colonic biopsies obtained from pigs on different diets. Paraffin sections were stained both chemically and with the following horseradish-peroxidase conjugated lectins: Canavalia ensiformis (Con-A), Limulus polyphemus (LPA), Lotus tetragonolobus (LTA), Arachis hypogaea (PNA), Ricinus communis (RCA1), Glycine max (SBA) and Triticum vulgaris (WGA). Using chemical staining procedures, only small quantitative differences were noted between the two organs. With respect to lectin staining, the mucus of the jejunum was characterized by the absence of Con-A binding sites, and colonic mucus consistently exhibited an absence of SBA affinity. After dietary modifications, O-acetyl sialic acid reactivity was lowered in the jejunum but was enhanced in the colon. In the jejunum, the glycoproteins became neuraminidase susceptible, whereas the colon became characterized by the absence of neutral mucins. The affinity for the tested lectins after the different diets was variable, but the most striking effects were observed after the fibreless diet (milk alone). Our data suggest the existence of marked regional variations in goblet-cell mucus and indicate significant differences between the glycoprotein components of the jejunal and colonic mucosa. Furthermore, the biosynthesis of mucins in both regions was altered by even only short-term feeding modifications.

Intrinsic innervation of the ewe cervix and its variations during pregnancy

The course of the cholinergic and adrenergic nerve fibers in the cervix of the ewe was investigated in nonpregnant and pregnant animals using an acetylcholinesterase method and fluorescence histochemistry. Both technics in nonpregnant animals revealed a rich network of acetylcholinesterase and norepinephrine positive nerves around the blood vessels while the muscular innervation was moderately positive. Acetylcholinesterase fibers were also concentrated beneath the surface epithelium forming a plexus-like arrangement where isolated ganglion cells could be seen. At mid pregnancy cholinergic and adrenergic fibers decreased in density. The intensity of fluorescence was weaker and nerve fiber morphology was modified. We endeavoured to relate our findings to the problem of the neural control of contractions and the opening of the cervix of the ewe which is poorly supplied in nerve fibers, particularly at mid pregnancy.

Effects of low doses of ochratoxin A after intratesticular injection in the rat

The toxic effect of various doses of ochratoxin A on the rat testis was investigated after a single intratesticular injection. At time of sacrifice (day 10) degenerating changes occur in the testicular tissues: seminiferous tubules dilatation, cytolysis of the seminiferous epithelium, hyperplasia of the interstitial tissue, vascular thrombosis. The relations between the blood supply disturbances and the observed lesions are discussed.