Plant invasion and fragmentation indirectly and contrastingly affect native plants and grassland arthropods

Plant invasion and habitat fragmentation have a detrimental effect on biodiversity in nearly all types of ecosystems. We compared the direct and indirect effects of the invasion of the common milkweed (Asclepias syriaca) on biodiversity patterns in different-sized Hungarian forest-steppe fragments. We assessed vegetation structure, measured temperature and soil moisture, and studied organisms with different ecological roles in invaded and non-invaded sites of fragments: plants, bees, butterflies, flower-visiting wasps, flies, true bugs, and spiders. Temperature and soil moisture were lower in invaded than in non-invaded area. Milkweed had a positive effect on plant species richness and flower abundance. In contrast, we mainly found indirect effects of invasion on arthropods through alteration of physical habitat characteristics and food resources. Pollinators were positively affected by native flowers, thus, milkweed indirectly supported pollinators. Similarly, we found higher species richness of herbivores in invaded sites than control sites, as species richness of true bugs also increased with increasing plant species richness. Predators were positively affected by complex vegetation structure, higher soil moisture and lower temperature. Furthermore, increasing fragment size had a strong negative effect on spider species richness of non-invaded sites, but no effect in invaded sites. Especially, grassland specialist spiders were more sensitive to fragment size than generalists, whereas generalist spider species rather profited from invasion. Although milkweed invades natural areas, we did not identify strong negative effects of its presence on the diversity of the grassland biota. However, the supportive effect of milkweed on a few generalist species homogenises the communities. The rate of invasion might increase with increasing fragmentation, therefore we recommend eliminating invasive plants from small habitat fragments to preserve the native biota. Focusing also on generalist species and revealing the indirect effects of invasions are essential for understanding the invasion mechanisms and would support restoration efforts.

Brenneria bubanii sp. nov., isolated from decaying plant tissues

Gram-negative, motile, rod-shaped bacterial strains (designated 4F2^T and Kf) were isolated from decaying tissues of various deciduous tree species. Phylogenetic analyses based on their 16S rRNA gene sequences showed that the novel isolates belong to the genus Brenneria and showed highest (98.3 %) sequence similarity to Brenneria goodwinii. Isolate 4F2^T formed a separate branch on the phylogenetic tree based on concatenated sequences of four housekeeping genes or whole genome sequences, clearly separate from Brenneria goodwinii, suggesting that novel isolates should belong to a novel species. Orthologous average nucleotide identity scores and in silico DNA-DNA hybridization values between isolate 4F2^T and type strains of other species in the genus Brenneria were less than 85 and 30 %, respectively, significantly lower than the species boundary cut-off values (95 and 70 %). A negative reaction for β-galactosidase, the ability to use dextrin and maltose as carbon sources, and an inability to use lactose are the main phenotypic characteristics that can be used to differentiate the novel isolates from B. goodwinii. Based on phenotypic and genotypic characteristics, isolates 4F2^T and Kf belong to a novel species of the genus Brenneria, for which the name Brenneria bubanii sp. nov. is proposed. The type strain is 4F2^T (=NCAIM B 02661^T=LMG 32183^T).

First Report of Colletotrichum godetiae Causing Anthracnose and Twig Blight on Persian Walnut in Hungary

Persian walnut (Juglans regia L.) fruit with preharvest anthracnose symptoms, necrotic fruit stalks, and twigs with necrotic buds, and peaks were collected in a Hungarian orchard next to Nágocs, in September 2018. Disease incidence was approximately 15% on a Hungarian bred walnut cultivar 'Milotai 10'. Similar symptoms were found on Persian walnut in other locations (eg. Milota, Érd, Sarród, and Kocs). Acervuli were observed on necrotic lesions on fruit, and twigs with pale orange conidial masses. Conidia were hyaline, unicellular, and fusiform. Morphometric measurements of conidia showed mean length ± SD × width ± SD = 15.9 ± 1.7 × 4.5 ± 0.4 μm, length/width ratio 1:0.3 (n=100). The fungus was isolated from conidial masses on potato dextrose agar (PDA) medium amended with Chlorampenicol (25 mg/L). A total of 12 isolates were obtained as pure cultures by single-spore isolations and incubated at 23°C in dark for 10 days. The colonies were white to gray or grayish-orange on the upper side and with black spots on the reverse side. The isolates showed morphological characteristics of Colletotrichum acutatum in sensu lato (Jayawardena et al. 2016). Molecular analyses were conducted to identify the exact species. Internal transcribed spacer (ITS) region, actin (ACT), and calmodulin (CAL) partial genes were amplified by ITS1F/ITS4R, ACT512F/ACT783R and CAL1/CAL2 primers (White at al. 1990, Carbone and Kohn 1999, O'Donnell et al. 2000). The sequences of ITS region (GenBank Accession Nos: MK367398-99, MK367401-02) showed 100% identity with C. godetiae sequence. Based on ACT gene (GenBank Accession Nos: MK415991-92, MK415994-95) were 100% identity with the deposited C. godetiae type strains from walnut. The obtained sequences of CAL gene (GenBank Accession Nos: MK415998-99, MK416001-02) were same and showed 100% with other C. godetiae sequences from other host plants. The fungus was identified as Colletotrichum godetiae Neerg. Pathogenicity tests were accomplished in the field and under laboratory conditions (25°C on thermostat) on 10 green 'Milotai 10' walnut fruit, and 10 walnut twigs each. Tests were conducted on living trees, collected fruit, and two-year-old twigs by inserting mycelial agar plugs (5 mm in diameter) onto wounded pericarp tissues, which were then wrapped with wet cotton and parafilm. Wounded tissues on 5 fruit and 5 two-year-old twigs were treated with non-colonized PDA plugs as noninoculated controls. After 14 d necrotic lesions 9 to 17 mm in diameter developed on fruit on living trees. Lengths of 12 to 17 mm and width of 7 to 12 mm necrosis was measured on phloem of walnut twigs, and almost two times larger in cambium. No necrosis developed around control wounds. Koch's postulates were fulfilled with the reisolation of the pathogen from symptomatic tissues, isolates were identical morphologically and by sequence analysis of ITS region, ACT, and CAL partial genes to the original isolates. Damm et al. (2012) described two C. godetiae strains associated with walnut, one isolated in Austria and another one of unknown origin. An epidemic event of walnut anthracnose caused by Colletotrichum species mainly C. godetiae was reported in France (Da Lio et al. 2018). The pathogen was isolated from nuts, buds, insects, and stems. To our knowledge, this is the first report of anthracnose of walnut fruit caused by C. godetiae in Hungary. Anthracnose caused by C. godetiae, and previously reported C. fioriniae (Varjas et al. 2019) is becoming an increasing preharvest problem on Persian walnut in Hungary.

Effects of laser treatment on the expression of cytosolic proteins in the synovium of patients with osteoarthritis

BACKGROUND AND OBJECTIVE

Low level laser therapy (LLLT) has been developed for non-invasive treatment of joint diseases. We have previously shown that LLLT influenced synovial protein expression in rheumatoid arthritis (RA). The aim of this study was to assess the effects of laser irradiation on osteoarthritic (OA) synovial protein expression.

STUDY DESIGN/MATERIALS AND METHODS

The synovial membrane samples removed from the knees of 6 OA patients were irradiated ex vivo using near infrared diode laser (807-811 nm; 25 J/cm(2) ). An untreated sample taken from the same patient served as control. Synovial protein separation and identification were performed by two-dimensional differential gel electrophoresis and mass spectrometry, respectively.

RESULTS

Eleven proteins showing altered expression due to laser irradiation were identified. There were three patients whose tissue samples demonstrated a significant increase (P < 0.05) in mitochondrial heat shock 60 kD protein 1 variant 1. The expression of the other proteins (calpain small subunit 1, tubulin alpha-1C and beta 2, vimentin variant 3, annexin A1, annexin A5, cofilin 1, transgelin, and collagen type VI alpha 2 chain precursor) significantly decreased (P < 0.05) compared to the control samples.

CONCLUSIONS

A single diode laser irradiation of the synovial samples of patients with osteoarthritis can statistically significantly alter the expression of some proteins in vitro. These findings provide some more evidence for biological efficacy of LLLT treatment, used for osteoarthritis.

Lonsdalea quercina subsp. populi subsp. nov., isolated from bark canker of poplar trees

Seven Gram-negative bacterial strains were isolated from oozing bark canker of poplar (Populus × euramericana) trees in Hungary. They showed high (>98.3%) 16S rRNA gene sequence similarity to Lonsdalea quercina; however, they differed from this species in several phenotypic characteristics. Multilocus sequence analysis based on three housekeeping genes (gyrB, atpD and infB) revealed, and DNA-DNA hybridization analysis confirmed, that this group of bacterial strains forms a distinct lineage within the species Lonsdalea quercina. A detailed study of phenotypic and physiological characteristics confirmed the separation of isolates from poplars from other subspecies of L. quercina; therefore, a novel subspecies, Lonsdalea quercina subsp. populi, type strain NY060(T) (=DSM 25466(T)=NCAIM B 02483(T)), is proposed.

The recently identified hexosaminidase D enzyme substantially contributes to the elevated hexosaminidase activity in rheumatoid arthritis

Since the 1970s, numerous reports have described elevated hexosaminidase activities in rheumatoid arthritis. However, due to the overlapping substrate specificities of different hexosaminidases, identification of the exact enzyme(s) responsible for the elevated activity remains incomplete. In this work we tested if the recently described enzyme, hexosaminidase D was expressed in human arthritic joints, and could contribute to the elevated hexosaminidase activity in rheumatoid arthritis. Thermostable β-d-N-acetyl-galactosaminidase (hexosaminidase D) activities were determined in synovial fluid samples, synovial membranes, synovial fibroblast cell strains and synovial fibroblast-derived extracellular vesicles of patients with rheumatoid arthritis and osteoarthritis using chromogenic substrates. Expression of the HEXDC gene was detected both in steady state and in TGF-β treated synovial fibroblasts by real time PCR. Strikingly, hexosaminidase D accounted for approximately 50% of the total β-N-acetyl-galactosaminidase activity in synovial membranes and synovial fibroblasts, and it was responsible for the vast majority of the β-d-N-acetyl-galactosaminidase activity in synovial fluid samples. TGF-β downregulated the expression of hexosaminidase D in synovial fibroblasts dose-dependently. Of note, significant activity of hexosaminidase D was also found in association with extracellular vesicles released by synovial fibroblasts. This first study that describes the expression and disease relevance of the HEXDC gene in humans demonstrates the expression of this novel enzyme within the joints, and suggests that its activity may significantly contribute to the overall local exoglycosidase activity.

Electron Microscopic Characteristics of β2-Microglobulin Amyloid Deposits in Long-Term Haemodialysis

The electron microscopic features of beta2-microglobulin amyloid, deposited in the synovial membrane, are presented and discussed. The patient, a 69-year-old woman underwent chronic hemodialysis for 3 years. Because of constant pain and destructive arthropathy, endoprosthesis of the hip joints were implanted. Extra- and intracellular filamentous-fibrillar amyloid deposits have been demonstrated in ultrathin sections. The extracellular amyloid deposits showed a loose, filamentous or fibrillar structure at the periphery and a dense central core. The loose, filamentous structure may represent an early stage of fresh, newly deposited beta2-microglobulin amyloid, while the condensed and fragmented amyloid filaments may be an advanced "mature" stage of amyloid deposition.

Gene expression and activity of cartilage degrading glycosidases in human rheumatoid arthritis and osteoarthritis synovial fibroblasts

INTRODUCTION

Similar to matrix metalloproteinases, glycosidases also play a major role in cartilage degradation. Carbohydrate cleavage products, generated by these latter enzymes, are released from degrading cartilage during arthritis. Some of the cleavage products (such as hyaluronate oligosaccharides) have been shown to bind to Toll-like receptors and provide endogenous danger signals, while others (like N-acetyl glucosamine) are reported to have chondroprotective functions. In the current study for the first time we systematically investigated the expression of glycosidases within the joints.

METHODS

Expressions of beta-D-hexosaminidase, beta-D-glucuronidase, hyaluronidase, sperm adhesion molecule 1 and klotho genes were measured in synovial fibroblasts and synovial membrane samples of patients with rheumatoid arthritis and osteoarthritis by real-time PCR. beta-D-Glucuronidase, beta-D-glucosaminidase and beta-D-galactosaminidase activities were characterized using chromogenic or fluorogenic substrates. Synovial fibroblast-derived microvesicles were also tested for glycosidase activity.

RESULTS

According to our data, beta-D-hexosaminidase, beta-D-glucuronidase, hyaluronidase, and klotho are expressed in the synovial membrane. Hexosaminidase is the major glycosidase expressed within the joints, and it is primarily produced by synovial fibroblasts. HexA subunit gene, one of the two genes encoding for the alpha or the beta chains of hexosaminidase, was characterized by the strongest gene expression. It was followed by the expression of HexB subunit gene and the beta-D-glucuronidase gene, while the expression of hyaluronidase-1 gene and the klotho gene was rather low in both synovial fibroblasts and synovial membrane samples. Tumor growth factor-beta1 profoundly downregulated glycosidase expression in both rheumatoid arthritis and osteoarthritis derived synovial fibroblasts. In addition, expression of cartilage-degrading glycosidases was moderately downregulated by proinflammatory cytokines including TNFalpha, IL-1beta and IL-17.

CONCLUSIONS

According to our present data, glycosidases expressed by synovial membranes and synovial fibroblasts are under negative regulation by some locally expressed cytokines both in rheumatoid arthritis and osteoarthritis. This does not exclude the possibility that these enzymes may contribute significantly to cartilage degradation in both joint diseases if acting in collaboration with the differentially upregulated proteases to deplete cartilage in glycosaminoglycans.

Synovial fluid exoglycosidases are predictors of rheumatoid arthritis and are effective in cartilage glycosaminoglycan depletion

OBJECTIVE

To analyze enzymes involved in joint damage by simultaneous investigation of glycosidases and matrix metalloproteinases (MMPs) in patients with various joint diseases.

METHODS

Activities of glycosidases (beta-D-glucuronidase, beta-D-N-acetyl-glucosaminidase, beta-D-N-acetyl-galactosaminidase, beta-D-galactosidase, and alpha-D-mannosidase) were tested at an acidic pH as well as at the original pH of the synovial fluid (SF) samples in parallel with activities of MMP-1 and MMP-9.

RESULTS

Patients with rheumatoid arthritis (RA) were characterized by significantly elevated activities of beta-D-glucuronidase and beta-D-N-acetyl-glucosaminidase in SF compared with patients with osteoarthritis, seronegative spondylarthritis, or acute sports injury. To select the best predictor for distinguishing among patient groups, a stepwise logistic regression analysis was performed; the strongest association was found to be between RA and beta-D-glucuronidase/beta-D-N-acetyl-glucosaminidase activities (measured at the pH of the SF). Further, a significant correlation was observed between the activity of SF beta-D-N-acetyl-glucosaminidase and the level of rheumatoid factor. In vitro digestion of human hyaline cartilage samples revealed that the dominant glycosidases, alone or in combination with MMPs, proved to be effective in depleting glycosaminoglycans (GAGs) from cartilage.

CONCLUSION

These results suggest that exoglycosidases, which are present in the SF of RA patients, may contribute to the depletion of GAGs from cartilage and thereby facilitate the invasion of synovial cells and their attachment to cartilage in RA.

[The role of gastrointestinal ulcer in the differential diagnosis of low back pain]

The authors call on attention for the differential diagnostical problems of low back pain and the importance of the Head zones by describing one case. A patient was admitted to hospital with severe symptoms of low back pain. In her previous medical history there were musculo-skeletal problems for many years in addition to continuous medical investigation and treatment for low back pain for three months. Careful examination revealed a five-centimetre large gastric ulcer in the background of her symptoms.

[Osteoblastoma in the iliac crest]

An 18 year old male patient is reported with a five year history of mild pain in his right hip. Radiological investigation showed a typical feature for osteoblastoma of iliac bone, with two niduses. En bloc excision was performed. The histological examination's result was also osteoblastoma.

Dissimilar biosynthesis of interleukin-6 by different areas of synovial membrane of patients with rheumatoid arthritis and osteoarthritis

In this study the IL-6 production was studied by synovial cells isolated from patients with either rheumatoid arthritis (RA) or osteoarthritis (OA). The kinetics of spontaneous IL-6 production differs in both groups. Furthermore, the induction of IL-6 by bacterial lipopolysaccharide (LPS) in synovial cell cultures of RA is much more rapid than in those of OA patients. On the other hand, more PGE2 was detected in culture supernatants from synovial adherent cells of OA than in those of RA patients. We also compared the IL-6 production and the amount of IL-6 mRNA in fragments derived from the areas of synovial tissue showing macroscopic signs of intensive inflammation (area A), with those from relatively intact (area B) synovial sites. In synovial fragments, but not in isolated adherent cells at area A the in vitro IL-6 production starts earlier in RA than in OA. In the area A, significantly more CD14+, CD43+ and HLA-DR+ cells were detected than in the other compartment less involved in local inflammatory events.

[First experiences with neodymium-YAG laser treatment of tracheal and bronchial diseases]

The authors describe their first three years experiences with the Neodymium-Yag Laser in tracheobronchial diseases. The treatments were performed with the MEDI-YAG equipment constructed in Hungary. According to the indication, local and/or general anaesthesia and generally the rigid bronchoscope was used. 38 tracheal, 34 main bronchial, 5 lobar and 2 distal alterations were treated. In case of tracheobronchial malignancy 3 complete and 20 partial recoveries were registered out of 45 patients; among benign tumours 7 complete and 4 partial recoveries out of 14 patients. In tracheal stenosis cases 12 complete and 4 partial recoveries came out of 18 patients. It can be stated that the Yag Laser treatment completes the bronchologist's instrumentation. The treatment may be curative in tracheal stenosis and benign tumours and palliative in malignancy by setting free the tracheobronchial system for ventilation. It may also prepare the patient for surgery and complete the complex treatment.

Unequal expression of complement C4A and C4B genes in rheumatoid synovial cells, human monocytoid and hepatoma-derived cell lines

C4A and C4B are closely related homologous complement proteins encoded in the class III region of major histocompatibility complex (MHC). The regulation of their expression is under genetic and hormonal control. In this study we investigated the synovial fluid plasma ratio of C4A and C4B of rheumatoid (RA) and osteoarthritis (OA) patients, and a predominance of the C4B gene expression by the synovial macrophages of RA patients was demonstrated. To clarify the tissue specificity of the expression of C4A and C4B genes, human monocytoid cell line U937 and hepatoma-derived HepG2 cells were studied. The gene expression of C4A and C4B were markedly different in these cells since a relative predominance of C4B mRNA in U937 cells and excess of that of C4A in HepG2 cells were detected. Recombinant interferon-gamma (IFN-gamma) up-regulated the expression of C4A gene in both cells, but had apparently no effect on the C4B gene. Our results demonstrate dissimilar expression patterns for the two human C4 genes, suggesting different tissue specific regulation of human C4A and C4B.