First Report of Root Rot of Pedunculate Oak and Other Forest Tree Species Caused by Phytophthora plurivora in the Czech Republic.

From 2006 to 2008, several similar Phytophthora isolates were obtained from roots of mature Quercus robur and other tree species (Acer platanoides, Fraxinus excelsior, Q. rubra, and Tilia cordata) in forests and parks in several areas in the Czech Republic. The trees were characterized by chlorotic and reduced foliage, crown dieback, and reduced root hairs. Several isolates of Phytophthora were obtained from necrotic roots of these trees and identified as Phytophthora plurivora Jung & Burgess (1). Isolated colonies grown on V8A medium were radiate to slightly chrysanthemum shaped with limited aerial mycelium in the center. Optimum growth was at 25°C, minimum at 5°C and maximum at 32°C. Radial growth of colonies averaged 6.4 mm/day at 20°C. The isolates were homothallic and produced abundant smooth-walled, spherical oogonia (23.3 to 29.1 µm in diameter), oospores were nearly plerotic or plerotic (21.8 to 26.9 µm in diameter), and the oospore wall was 1.2 to 1.4 µm thick. Antheridia were usually paragynous and measured 8.4 to 12 × 6.5 to 8 µm, but amphigynous antheridia were occasionally observed. Noncaducous, semipapillate sporangia formed on simple or sympodial sporangiophores, were obpyriform, ovoid, ellipsoid or irregular in shape, and occasionally distorted with more than one apex. Sporangia dimensions were 33 to 65 × 24 to 33 µm; L/B ratio 1.2 to 1.6 (-2.1). Comparison of DNA sequences of internal transcribed spacer (ITS) regions of isolates (representative strain GenBank Accession No. FJ952382) confirmed the 100% identity of P. plurivora (1). The soil infestation test was conducted using a P. plurivora isolate acquired from roots of Q. robur and 20 3-year-old plants of Q. robur. Sterilized millet seeds colonized by pathogen with the method as described (2) were used as inoculation medium and added into sterilized peat substrate at the rate of 0.5% (vol/vol). The plants were cultivated in 5.8-liter pots in a greenhouse (20°C, 16-h/8-h photoperiod). After 4 months, the roots of all plants were washed, dried, and weighed. The root biomass of 20 infected plants was significantly reduced by approximately 25% on average compared with the control 20 plants (P < 0.05, t-test, Statistica 7.1). The pathogen was consistently reisolated from the roots of infected plants but not from control plants. Stem inoculation tests were conducted with 20 replicates in each group of 2-year-old plants of oak, maple, ash, and lime and isolates acquired from the hosts. On each seedling, a 5-mm-diameter bark plug was removed 5 cm above the collar. The inoculum (5-mm-diameter V8A agar plug with actively growing mycelium) was applied to the exposed substrate. The wounds were sealed with Parafilm. Stem necrosis developed in all cases after 1 to 2 weeks, whereas control plants remained healthy. The pathogen was successfully reisolated from necrotic stem tissues. To our knowledge, this is the first report of P. plurivora causing root rot on oak, maple, ash, and lime in the Czech Republic. On the basis of the host range and distribution of P. plurivora in the Czech Republic, it can be assumed that, as elsewhere in Europe (1), this pathogen is widespread and is a common cause of decline of many tree species. References: (1) T. Jung and T. I. Burgess. Persoonia 22:95, 2009. (2) C. Robin et al. Plant Pathol. 50:708, 2001.

First Report of Phoma exigua var. populi Causing Canker of Twigs and Shoots of Poplar in the Czech Republic.

During 2007 and the spring of 2008, a disease of poplars (Populus spp.) resembling the Dothichiza canker was found in plantations of fast-growing trees in central Bohemia and in southern Moravia where it was more abundant. The yellowish brown-to-brown, round or elongated cankers occurred on damaged shoots and twigs. Tissues directly under the bark were discolored and turned black. As the cankers enlarged, infected shoots and twigs died after several months. Small, black, gregarious pycnidia were observed under the bark or in lenticels after several weeks. The disease occurred on Populus nigra, P. × euroamericana cvs. Regenerata, Robusta, Brabantica, Spreewald, CZ-425/58, Blanc du Poitou, and Flaschlanden, and other Populus spp. Isolates of a species of Phoma were acquired by culturing damaged tissues on agar plates containing 3% oatmeal agar (OA) and 2% malt agar. Initial identification of the isolates was done by cultural and morphological characteristics (1). Colonies were floccose, aerial mycelium was olivaceous gray to gray, reverse olivaceous gray sometimes with darker tones at the margins or in the colony center, and NaOH reaction was negative. The growth rate was 42 to 56 in diameter after 7 days at 20°C on OA (optimum temperature for growth was 22°C with a minimum of 1°C and a maximum of 28 to 29°C). Pycnidia in culture scattered, were globose or subglobose, obviously with one nonpapillate ostiolum, olivaceous black or black, 120 to 370 µm in diameter, and conidial exudate was whitish. Phialides were globose to ampulliform and 3 to 7 × 3 to 6 µm. Conidia were hyaline, ellipsoidal, often guttulate, 3.1 to 7.8 × 1.9 to 3.1 µm, and L/B ratio 1.4:3.1. Septate conidia occurred only on natural substrate up to 10.6 × 3.9 µm. Morphological and cultural characteristics resembled those of P. exiqua var. populi Gruyter & P. Scheer (1). The internal transcribed spacer (ITS) sequence (GenBank Accession No EU562206) for the representative isolate (CCF No 3759) confirmed 100% identity to P. exigua. Pathogenicity was confirmed with 1-year-old P. nigra plants during a 2-month greenhouse experiment at 15 to 20°C. Fifteen replicate plants were wounded (5-mm diameter), inoculated with 5-mm OA plugs from actively growing colonies (isolate CCF No 3759), and sealed by Parafilming. An additional 15 control plants following wounding were inoculated with a sterile agar plug. After 3 to 4 weeks, yellowish or brownish necrotic lesions ranging from 1 to 1.5 cm long developed on all inoculated plants. The pathogen was successfully reisolated from lesions and the control plants were asymptomatic. P. exigua var. populi is considered an opportunistic poplar and willow pathogen (2) that becomes more important in winter (1). The pathogen potentially invades host tissues damaged by frost, sun scald, or weakened by excessive transpiration during sunny winter days. To our knowledge, this is the first record of the pathogen on poplars in the Czech Republic, which may have an economic impact on short-rotation coppice plantations. References: (1) J. de Gruyter and P. Scheer. J. Phytopathol. 146:411, 1998. (2) H. A. van der Aa et al. Persoonia 17:435, 2000.

Double germline mutations in the RET Proto-oncogene in MEN 2A and MEN 2B kindreds.

Medullary thyroid carcinoma (MTC) is a rare form of thyroid cancer representing about 10% of all thyroid malignancies. It occurs mostly as a sporadic tumor or in association with autosomal dominant inherited cancer syndromes--multiple endocrine neoplasia (MEN) types 2A and 2B and familial MTC. Germline mutations in exons 8, 10, 11, 13, 14, 15 and 16 of the RET proto-oncogene are found in most of the familial cases. There are only a few published data reporting multiple germline mutations in the RET proto-oncogene. We have detected double germline mutations in 2 different exons on the same RET allele in two MEN 2 families. In the MEN 2A family, double germline mutation in exons 10 (Cys620Phe) and 13 (Tyr791Phe) was detected. In the MEN 2B family, beside the classical germline mutation in exon 16 (Met918Thr) a second germline mutation in exon 13 (Tyr791Phe) was found. This study revealed that MEN 2 syndromes can also be caused by double germline mutations in the RET proto-oncogene and these families can be added to small worldwide cohort of families with multiple germline mutations.

[Hormonal therapy of osteoporosis in women after ovariectomy]. / Hormonální lécba osteoporózy u zen po ovarektomii.

In 25 women with ovariectomy made before the menopause and in a control group of 11 women after the menopause the authors examined laboratory values of the calcium phosphate metabolism and bone density. They repeated the examinations 6 and 12 months after treatment with a combined sequence oestrogen and gestagen preparation--Presomen 0.6 comb. of KaliChemie (Solvay), FRG. After one year of treatment the calcium and phosphate blood levels did not change substantially nor the alkaline phosphatase activity or its bone isoenzyme (although an insignificant increase occurred after six months). On the other hand, the originally elevated calciuria suggesting enhanced resorption of bone mineral, declined in the group of ovariectomized women on average by 3.02 mmol/d, i.e. the women lost by 120 mg less Ca, and the density increased by 6.80%! In a group of postmenopausal women the calciuria declined on average by 2.80 mmol (urinary Ca losses were by 113 mg lower) and the density increased by 4.18%. The results of this investigation support unequivocally not only the benefit but also the necessity of combined hormonal treatment after ovariectomy made before the menopause and provide also evidence of its importance in the prevention of osteoporosis in postmenopausal women.

The rational use of 201Tl scintigraphy in the evaluation of differentiated thyroid cancer.

Fifteen patients with differentiated thyroid cancer were examined following 131I thyroid ablation, of these seven were examined after radio-iodine therapy to disseminated neck cancer. They had no further radio-iodine uptake and were evaluated using a 201Tl scan. In thirteen patients there was a good correlation between the results and the clinical diagnosis, showing no uptake in seven subjects with negative clinical findings, and positive delineation of tumour tissue in the neck region in six patients. The remaining two patients with lymph node metastases after previous radio-iodine irradiation showed marked clinical regression of the metastases with absent uptake of both 131I and 201Tl, probably due to radiation-induced changes. The comparison of thallium scans with plasma thyroglobulin levels showed certain differences (high plasma thyroglobulin without any proof of remaining thyroid tissue in one patient and normal/low plasma thyroglobulin in the presence of a tumour in two patients) but both measurements could give additional information. It is believed that while in the differential diagnosis of a thyroid nodule no important information could be expected of scanning (compared with the high value of aspiration biopsy), the evaluation of patients without 131I uptake by 201Tl scans could provide important information for further therapy.