The potato tuber content of microelements as affected by organic fertilisation and production system.

The objective of the work was to determine the effect of undersown catch crops, which were either autumn-incorporated or left on the soil surface as mulch for spring incorporation, on the microelement content in the tubers of potato cultivated in the integrated and organic production system. Field research was conducted at the Zawady Experimental Farm owned by Siedlce University of Natural Sciences and Humanities, Poland (52° 03' 39″ N, 22° 33' 80″ E). The following two factors were examined in the study: (i) organic fertilisation, control, farmyard manure, serradella, westerwolds ryegrass, serradella applied as mulch and westerwolds ryegrass applied as mulch and (ii) production system, organic and integrated. Microelements (B, Cu, Fe, Mn, Zn) were determined in potato tubers samples. The tubers of potato manured with autumn-incorporated serradella had the highest iron and zinc contents, whereas tubers following autumn-incorporated serradella and spring-incorporated serradella mulch had the highest boron content. Manuring with undersown catch crops and farmyard manure contributed to a decline in the potato tuber content of copper and manganese. Potato cultivated in the integrated production system contained more copper, manganese and zinc, whereas organic tubers had more iron and boron.

Linguistic measures of chemical diversity and the "keywords" of molecular collections.

Computerized linguistic analyses have proven of immense value in comparing and searching through large text collections ("corpora"), including those deposited on the Internet - indeed, it would nowadays be hard to imagine browsing the Web without, for instance, search algorithms extracting most appropriate keywords from documents. This paper describes how such corpus-linguistic concepts can be extended to chemistry based on characteristic "chemical words" that span more than traditional functional groups and, instead, look at common structural fragments molecules share. Using these words, it is possible to quantify the diversity of chemical collections/databases in new ways and to define molecular "keywords" by which such collections are best characterized and annotated.

Multiple brain metastases from malignant peripheral nerve sheath tumour (MPNST).

Malignant peripheral nerve sheath tumours (MPNSTs) are rare soft tissue neoplasms arising from elements of the nerve sheath that often occur in the context of neurofibromatosis (NF) type 1. Their poor prognosis results from high local recurrence rate and distant dissemination. Nevertheless, the brain metastases are exceptional. We are presenting an unusual case of intrathoracic MPNST in a 33-year-old man with a five-year clinical course characterised by multiple times local recurrences of primary tumour and multiple remote metastases into the brain structures, thyroid and suprarenal gland. Moreover, the cerebellar metastasis regrew in spite of its total excision. Histologically, brain metastatic tumours were composed of spindle cells closely arranged in interlacing and woven fascicles. This highly cellular nerve tissue exhibited an advanced nuclear hyperchromasia and a high mitotic activity. The tumour exhibited rich delicate reticulin network. The schwannian nature of brain metastases has been confirmed by immunohistochemical findings showing S-100 protein and GFAP expression and ultrastructural evidences of the pericellular basal lamina.

Haemangioblastoma of the posterior cranial fossa: clinico-neuropathological study.

Haemangioblastoma (HBs) may occur sporadically in the central nervous system, or in association with von Hippel-Lindau (VHL) disease. Haemangioblastoma of the central nervous system is often seen in the posterior cranial fossa. VHL is an autosomaly dominant disorder. In sporadic HBs tumours, VHL alleles are reported to be inactive in up to 50% of tumours. Five patients with tumours of the posterior cranial fossa were examined by scyntygrapghy, computed tomography or magnetic resonance imaging (MRI). Metastases were initially diagnosed by neuroimaging examinations in two patients, and HBs in the remaining cases. In four patients, tumours were removed neurosurgically. Two patients had evidence of VHL disease. All resected tumours and autopsy materials were studied histologically and immunohistologically. Most antibodies that were used showed positive immunoreactions with stromal, endothelial, and pericyte or macrophage cells in tumours diagnosed as haemangioblastoma. Preoperative diagnosis of haemangioblastoma is mostly precise with MRI or magnetic resonance angiograghy. The surgical treatment of HBs is only a part of the complex therapeutical process. Diagnosis based on the gene analysis can be very useful in early detection or protection against potential recurrence of this disease in patients and their families.