Ultrastructure and phylogeny of the parasite Henneguya carolina sp. nov. (Myxozoa), from the marine fish Trachinotus carolinus in Brazil

Microscopic and molecular procedures are used to describe a new myxosporean species, Henneguya carolina sp. nov., found infecting the intestine of the marine teleost fish Trachinotus carolinus on the southern Atlantic coast of Brazil. Spherical to ellipsoid cysts, measuring up to ~750 µm, display synchronous development. Mature myxospores are ellipsoidal with a bifurcated caudal process. Myxospore body length, width, and thickness are 12.7 ± 0.8 (12.0-13.4) µm, 8.8 ± 0.6 (7.5-9.6) µm, and 5.8 ± 0.4 (5.0-6.4) µm, respectively; 2 equal caudal processes are 16.8 ± 1.1 (15.9-18.0) µm long, and the total myxospore length is 29.4 ± 0.8 (28.4-30.4) µm. Two pyriform polar capsules measure 5.0 ± 0.5 (4.6-5.6) × 2.4 ± 0.4 (1.9-2.9) µm, and each contains a polar filament forming 3 to 4 coils. Sporoplasm is binucleated and presents a spherical vacuole surrounded by numerous globular sporoplasmosomes. Molecular analysis of the small subunit rRNA gene by maximum parsimony, neighbor joining, and maximum likelihood reveals the parasite clustering together with other myxobolids that are histozoic in marine fish of the order Perciformes, thereby strengthening the contention that the host phylogenetic relationships and aquatic environment are the strongest evolutionary signal for myxosporeans of the family Myxobolidae.

Ultrastructure of novel thrombocytes in the dog snapper Lutjanus jocu

Myxosporean cysts containing spores of Henneguya sp. were observed in the gills of the dog snapper Lutjanus jocu. Adjacent to the cysts were capillaries, allowing observation of peripheral blood cells. Numerous white blood cells displaying uncommon cytoplasmic projections were observed amongst the erythrocytes. Their morphology allowed them to be identified as thrombocytes (TCs). Each TC displayed 18-26 cytoplasmic projections, most of which were in close proximity to erythrocytes. At their apical end, each cytoplasmic projection presented an ellipsoidal vacuole (c. 0·6 µm × 0·3 µm) from which a secretory tubule, 0·3-0·4 µm long and c. 120 nm in total diameter, extended towards the periphery of the TC plasmalemma and fused with the cellular membrane. From this opening, contents of vacuoles were apparently released into the lumen of the capillaries. Other vacuoles with similar features, and containing an electron-lucent matrix, were observed in the cytoplasm of the TC. This is the first description of fish TC with these ultrastructural features and organization, which suggest that they perform a secretory function.

Accessibility of blood affects the attractiveness of cattle to horn flies

The burden of infestation of the horn fly, Haematobia irritans (Linnaeus) (Diptera: Muscidae), differs among bovines within the same herd. We hypothesized that these differences might be related to the epidermal thickness of the cattle and the blood intake capacity of the fly. Results showed that dark animals carried more flies and had a thinner epidermis than light-coloured animals, which was consistent with the greater haemoglobin content found in flies caught on darker cattle. Similarly, epidermal thickness increased with body weight, whereas haemoglobin content decreased. Overall, we suggest that accessibility of blood is a factor that partially explains cattle attractiveness to flies.

Gall induction may benefit host plant: a case of a gall wasp and eucalyptus tree

Gall-inducing insects display intimate interactions with their host plants, usually described as parasitic relationships; the galls seem to favor the galler alone. We report on a case in which the presence of the galls induced by Leptocybe invasa Fisher & LaSalle (Hymenoptera; Eulophidae) benefit its host plant, the river red gum Eucalyptus camaldulensis Dehnh. Field observations showed that E. camaldulensis plants infected by this gall wasp were less susceptible to cold injury than neighboring conspecific plants without galls. In the laboratory, frost resistance was compared between galled and non-galled plants which were both divided into two subgroups: cold-acclimated plants and plants that were non-acclimated. Galled plants displayed higher frost resistance than the non-galled ones, and the differences were higher in non-acclimated plants compared with acclimated ones. Physiological changes in host plant were determined by chemical analyses of chlorophylls, proteins, soluble sugars and anthocyanin contents. The results showed higher values of all physiological parameters in the galled plants, supporting the hypothesis that the presence of the gall wasp induces physiological changes on the plant foliage, which may in turn increase plant defense mechanisms against cold. Therefore, the toll of galling by the herbivore may pay off by the host plant acquiring increased frost resistance. This work provides evidence for physiological changes induced by a herbivore which might have a positive indirect effect on the host plant, promoting frost resistance such as cold acclimation.

HIF-independent role of prolyl hydroxylases in the cellular response to amino acids

Hypoxia-inducible factor (HIF) prolyl hydroxylases (PHDs) are α-ketoglutarate (αKG)-dependent dioxygenases that function as cellular oxygen sensors. However, PHD activity also depends on factors other than oxygen, especially αKG, a key metabolic compound closely linked to amino-acid metabolism. We examined the connection between amino-acid availability and PHD activity. We found that amino-acid starvation leads to αKG depletion and to PHD inactivation but not to HIF stabilization. Furthermore, pharmacologic or genetic inhibition of PHDs induced autophagy and prevented mammalian target of rapamycin complex 1 (mTORC1) activation by amino acids in a HIF-independent manner. Therefore, PHDs sense not only oxygen but also respond to amino acids, constituting a broad intracellular nutrient-sensing network.

Morphological and molecular characterization of a new myxozoan species (Myxosporea) infecting the gall bladder of Raja clavata (Chondrichthyes), from the Portuguese Atlantic Coast

Microscopic and molecular procedures are used to describe a new myxosporean species, Chloromyxum clavatum n. sp., infecting the cartilaginous fish Raja clavata Linnaeus, 1758 (Chondrichthyes: Rajidae), collected from the northwest Atlantic coast of Portugal. Young plasmodia and mature spores were found floating free in the gall bladder of R. clavata . Spores were spherical to subspherical with a pointed anterior end, measuring14.4 ± 0.5 μm (n = 25) in length, 11.9 ± 0.5 μm (n = 25) in width, and 9.4 ± 0.5 μm (n = 15) in thickness. The spore's wall was composed of 2 equally sized valves, each displaying 6-8 elevated surface ridges and a bundle of several tapering caudal filaments attached to the basal portion. Spores contained 4 pyriform equally sized polar capsules (5.5 ± 0.4 μm × 2.9 ± 0.5 μm) (n = 25), each possessing an obliquely arranged isofilar polar filament coiled in 7-8 coils. Morphological data, host specificity, tissue tropism, and molecular analysis of the SSU rDNA gene identify this parasite as a new species of Chloromyxum. Neighbor-joining and maximum likelihood further reveal the parasite clustering with other species of Chloromyxum infecting the gall bladder of marine cartilaginous fish to form a clade positioned at the base of the freshwater clade, therefore constituting an exception to the major division of the class Myxosporea into the freshwater and marine clades, while supporting the existence of a correlation between tissue tropism and myxosporean phylogeny.

Agarose cell block technique as a complementary method in the diagnosis of fungal osteomyelitis in a dog

A 7-year-old Labrador Retriever female dog presenting left forelimb lameness for one day was admitted to the Veterinary Hospital (UNESP-Botucatu) for clinical evaluation. Several tests, including blood and image analysis, microbiological culture and cytology of lytic areas of affected bone were made in order to establish a diagnosis. Serum biochemical profile revealed increased levels of liver enzymes, plasma globulin, creatine kinase (CK) and calcium. Hemogram revealed anemia and leukocytosis; left humerus image analysis revealed an osteolytic lesion and cytology revealed a suppurative periostitis. Differential diagnosis was a nonspecific infectious inflammatory process or osteosarcoma. Since it was not possible to achieve a definitive diagnosis and there was a highly suspicious for an infectious agent, an agarose cell block of the bone marrow fine-needle aspiration was made. The cytological examination of cell block presented similar findings as described previously. However, additional stains including periodic acid-Schiff (PAS) were positive for fungal hyphae, which rendered a diagnosis of fungal osteomyelitis due to Aspergillus spp. This case report illustrates an uncommon cause of osteomyelitis for breed that was diagnosed by an underused method in veterinary medicine.

Circulating adipokine levels in Portuguese patients with psoriasis vulgaris according to body mass index, severity and therapy

BACKGROUND

Psoriasis vulgaris is associated with overweight/obesity and with increased C-reactive protein (CRP), tumour necrosis factor (TNF)-α, interleukin (IL)-6, leptin and resistin levels and decreased adiponectin levels.

OBJECTIVES

To understand the role/relationship of adipokines, as well as CRP, in a Portuguese psoriatic population, by assessing the relationship of their levels with psoriasis severity, defined by Psoriasis Area and Severity Index (PASI), with obesity, defined by body mass index (BMI), and psoriasis therapy.

METHODS

A cross-sectional (n=66) and longitudinal study (before and after 12 weeks of therapy; n=44) was performed; 10 patients started topical treatment, 17 narrow-band ultraviolet B (NBUVB) and 17 psolaren associated with UVA (PUVA).

RESULTS

Patients presented significantly higher BMI, leptin, resistin, TNF-α, IL-6 and CRP and significantly lower adiponectin values. CRP and IL-6 correlated with PASI. Adiponectin and leptin were more altered in patients with higher BMI. Concerning severity, CRP, resistin and adiponectin were more altered in the severer forms. After treatment, a significant reduction in PASI, CRP, resistin, TNF-α and IL-6, and a significant rise in adiponectin were observed. Nonetheless, CRP and adiponectin remained different from those of control. Concerning therapies, topical therapy was not associated with any significant change, except for TNF-α. After NBUVB, a significant reduction was observed in TNF-α and in CRP. For PUVA, we observed a significant reduction in TNF-α, IL-6 and CRP, and a significant increase in adiponectin.

CONCLUSION

In psoriatic patients, increased overweight/obesity was associated with raised leptin levels and decreased adiponectin levels. Leptin may contribute to enhance the inflammatory process in overweight/obese psoriatic patients. Resistin, IL-6, CRP and adiponectin levels appear to be dependent on psoriasis severity. CRP, together with IL-6, appears to be a useful marker of psoriasis severity. Both NBUVB and PUVA were effective; however, PUVA results seem to be more successful. Nonetheless, after NBUVB and PUVA, a low-grade inflammation still persists.

Interleukin (IL)-22, IL-17, IL-23, IL-8, vascular endothelial growth factor and tumour necrosis factor-α levels in patients with psoriasis before, during and after psoralen-ultraviolet A and narrowband ultraviolet B therapy

BACKGROUND

Several cross-sectional studies have shown that different cytokines and growth factors are enhanced in psoriasis.

OBJECTIVES

We aimed to understand the role/relation of interleukin (IL)-22, IL-17, IL-23, IL-8, vascular endothelial growth factor (VEGF) and tumour necrosis factor (TNF)-α in psoriasis vulgaris, addressing their levels and changes before, during and after psoralen-ultraviolet A (PUVA) and narrowband ultraviolet B (NB-UVB) treatment.

METHODS

A cross-sectional and a longitudinal study (n = 34) - before (T0) and at 3 (T3), 6 (T6) and 12 (T12) weeks of NB-UVB and PUVA therapy - were performed; 17 patients started NB-UVB and 17 PUVA, and IL-22, IL-17, IL-23, IL-8, TNF-α and VEGF levels were evaluated.

RESULTS

At T0, compared with controls (n = 20), all the parameters were significantly higher in patients, except for TNF-α. Both NB-UVB and PUVA treatment gave, at T3, a significant decrease in TNF-α and IL-23; IL-22 and IL-17 decreased significantly at T6; all parameters and Psoriasis Area and Severity Index decreased significantly at T12. However, in both groups, at T12, VEGF was still significantly higher than control.

CONCLUSIONS

Psoriasis seems to be a complex disease in which the cytokine network is disturbed, namely in levels of IL-22, IL-17, IL-23, IL-8, TNF-α and VEGF. NB-UVB and PUVA follow-up studies suggested that the reduction in the IL-23/Th17 axis might be important in the pathogenic mechanisms of psoriasis. Further follow-up studies of patients with psoriasis treated with these and other therapies could be very helpful for the understanding of the disturbance in the cytokine network in psoriasis and indirectly in its pathogenesis.

C-reactive protein and leucocyte activation in psoriasis vulgaris according to severity and therapy

BACKGROUND

Psoriasis vulgaris is a chronic recurrent inflammatory skin disease and psoriatic lesions have shown leucocyte infiltration.

OBJECTIVES

We aimed to study C-reactive protein (CRP) and leucocyte activation markers/inhibitors as potential monitors of psoriasis vulgaris.

METHODS

A cross-sectional (n = 73) and a longitudinal study (before, at 3, 6 and 12 weeks of therapy; n = 47) was performed; 10 patients started topical treatment, 17 narrow-band ultraviolet light B (NBUVB) and 20 psolaren associated to UVA (PUVA); psoriasis severity was defined by Psoriasis Area and Severity Index (PASI).

RESULTS

Compared with control (n = 38), we found higher CRP levels, total leukocyte/neutrophil count, elastase, lactoferrin and alpha1-antitrypsin. Increasing PASI was linked to increasing CRP and a trend to higher elastase and lactoferrin, suggesting that worsening enhances inflammatory response with neutrophil activation. CRP correlated with PASI, total leucocytes, neutrophils, elastase, lactoferrin and alpha1-antitrypsin. NBUVB and PUVA presented similar effects.

CONCLUSION

We propose CRP as a useful marker of psoriasis severity that could be used to monitor psoriasis and its treatment, and, together with PASI and elastase, could also be used as a global index of severity.

Cross-talk between inflammation,coagulation/fibrinolysis and vascular access in hemodialysis patients

This work aimed to study the association between fibrinolytic/endothelial cell function and inflammatory markers in chronic kidney disease (CKD) patients undergoing hemodialysis (HD) and recombinant human erythropoietin (rhEPO) therapies, and its relationship with the type of vascular access (VA) used for the HD procedure. As fibrinolytic/endothelial cell function markers we evaluated plasminogen activator inhibitor type-1 (PAI-1), tissue plasminogen activator (tPA) and D-dimers, and as inflammatory markers; C-reactive protein (CRP), soluble interleukin (IL)-2 receptor (s-IL2R), IL-6 and serum albumin levels. The study was performed in 50 CKD patients undergoing regular HD, 11 with a central venous dialysis catheter (CVC) and 39 with an arteriovenous fistula (AVF), and in 25 healthy controls. Compared to controls, CKD patients presented with significantly higher levels of CRP, s-IL2R, IL-6 and D-dimers, and significantly lower levels of PAI-1. The tPA/PAI-1 ratio was significantly higher in CKD patients. We also found statistical significant correlations in CKD patients between D-dimerslevels and inflammatory markers: CRP, albumin, s-IL2R and IL-6. When comparing the two groups of CKD patients, we found that those with a CVC presented statistically significant lower levels of hemoglobin concentration and albumin, and higher levels of CRP, IL-6, D-dimers and tPA. Our results showed an association between fibrinolytic/ endothelial cell function and increased inflammatory markers in CKD patients. The increased levels of Ddimer, tPA and inflammatory markers in CKD patients using a CVC, led us to propose a relationship between the type of VA chosen for HD, and the risk of thrombogenesis.