Zearalenone and its metabolites: Effect on human health, metabolism and neutralisation methods.

Mycotoxins are natural compounds produced as secondary metabolites by mold fungi belonging mainly to the Fusarium family, commonly found on plants such as corn or small grains in the temperate climate zone. One of these mycotoxins is zearalenone, which is classified as a xenoestrogen, an exogenous compound which resembles the structure of naturally occurring estrogens with its chemical structure. This property of zearalenone determines its ability to bind to estrogen receptors of cell and its bioaccumulation. This leads to disorders of the hormonal balance of the body, which in consequence may lead to numerous diseases of reproductive system such as prostate, ovarian, cervical or breast cancers. High risk posed by long-term exposure to contaminated food forces the modern science to develop and implement effective methods of zearalenone neutralisation. This work is a review of current state of knowledge on toxic effects of zearalenone, its metabolism in biological systems and proposed methods of its neutralisation.

Leucoreduction helps to preserve activity of antioxidant barrier enzymes in stored red blood cell concentrates.

BACKGROUND: Oxidoreductive imbalance is a major cause of excessive haemolysis in in vitro conditions. Leucocytes and blood platelets present in red blood cell concentrates (RBCs) are one of the sources of free radicals, which have a significant effect on the status of stored erythrocytes. The study objective was to assess the effect of leucoreduction on the intensity of lipid peroxidation and the activity of antioxidant barrier enzymes in RBC. STUDY DESIGN AND METHODS: Red blood cell concentrates units obtained from 10 whole-blood units were split into two equal units, one of which was leucoreduced on the day of donation. Both units were stored for 35 days. The following markers of oxidoreductive balance were measured on day 0 (donation day) and on storage days 7, 14, 21 and 35: concentration of malondialdehyde (MDA) and activities of antioxidant barrier components, that is superoxide dismutase, glutathione peroxidase and glutathione reductase. RESULTS: Lipid peroxidation in leucodepleted units (LRBC) was slower than that in non-leucodepleted ones. The analysis of LRBC revealed statistically significant decrease in concentrations of MDA. The activities of superoxide dismutase, glutathione peroxidase and glutathione reductase were higher throughout the storage period as compared to non-leucoreduced RBC. Statistically significant differences between RBC and LRBC units were noted throughout the storage in the activity of lactate dehydrogenase, and concentrations of K(+) ions and free haemoglobin. CONCLUSIONS: Leucoreduction of RBC before storage helps to preserve the activity of antioxidant barrier enzymes in stored RBCs and significantly improves the quality of stored red blood cell components.

Optimisation of illumination for photodynamic therapy with mTHPC on normal colon and a transplantable tumour in rats.

Recent reports suggest that the effect of photodynamic therapy (PDT) can be enhanced by fractionating the light dose or reducing the light fluence rate. We assessed these options on two tissues in rats (normal colon and a transplanted fibrosarcoma) using the photosensitiser meta-tetrahydroxyphenylchlorin (mTHPC). Animals were sensitised with 0.3 mg/kg mTHPC, 3 days prior to illumination with red light (652 nm) using a single fibre touching the target tissue and killed 1-3 days later for quantitative measurement of the extent of PDT necrosis. Results were similar for both tissues, although the differences between illumination regimens were less marked in tumour tissue. Using continuous illumination and a fixed low energy in colon, the extent of necrosis was up to almost three times larger with 5 mW than with 100 mW, although the maximum attainable necrosis was independent of power. The long treatment time using 5 mW could be halved without loss of effect by increasing the power during treatment. Dividing the light into two equal fractions at 100 mW increased the lesion size by up to 20% in colon (independent of the timing of the dark interval), but by only 10% in tumour and had no effect at 20 mW. Previous studies using 5-aminolaevulinic acid (ALA) showed a much larger effect of fractionation that was critically dependent on the timing of the dark interval. We postulate that enhancement of PDT by fractionation is due to improved oxygen supply to the treated area which may be due to reversal of temporary vascular occlusion (more likely with ALA) or less rapid photochemical consumption of oxygen (more likely with mTHPC). At lower fluence rates, the oxygen consumption rate is not fast enough to be improved by fractionation. We conclude that fractionated or low power light delivery can enhance PDT with mTHPC. Although the effects are not large, this may be of value for interstitial treatment of solid tumours when multiple sites are treated simultaneously.

Photodynamic therapy for cancer of the pancreas.

BACKGROUND: Few pancreatic cancers are suitable for surgery and few respond to chemoradiation. Photodynamic therapy produces local necrosis of tissue with light after prior administration of a photosensitising agent, and in experimental studies can be tolerated by the pancreas and surrounding normal tissue. AIMS: To undertake a phase I study of photodynamic therapy for cancer of the pancreas. PATIENTS: Sixteen patients with inoperable adenocarcinomas (2.5-6 cm in diameter) localised to the region of the head of the pancreas were studied. All presented with obstructive jaundice which was relieved by biliary stenting prior to further treatment. METHODS: Patients were photosensitised with 0.15 mg/kg meso-tetrahydroxyphenyl chlorin intravenously. Three days later, light was delivered to the cancer percutaneously using fibres positioned under computerised tomographic guidance. Three had subsequent chemotherapy. RESULTS: All patients had substantial tumour necrosis on scans after treatment. Fourteen of 16 left hospital within 10 days. Eleven had a Karnofsky performance status of 100 prior to treatment. In 10 it returned to 100 at one month. Two patients with tumour involving the gastroduodenal artery had significant gastrointestinal bleeds (controlled without surgery). Three patients developed duodenal obstruction during follow up that may have been related to treatment. There was no treatment related mortality. The median survival time after photodynamic therapy was 9.5 months (range 4-30). Seven of 16 patients (44%) were alive one year after photodynamic therapy. CONCLUSIONS: Photodynamic therapy can produce necrosis in pancreatic cancers with an acceptable morbidity although care is required for tumours invading the duodenal wall or involving the gastroduodenal artery. Further studies are indicated to assess its influence on the course of the disease, alone or in combination with chemoradiation.

[Rubral tremor of Holmes, rare case of pathological tremor: case report]. / Drzenie czerwienne (Holmesa)--rzadko spotykana postac drzenia patologicznego (opis przypadku).

The authors present a very rare case of Holmes tremor (previously known as rubral or midbrain tremor). In all described till now cases the tremor was due to a known and revealed in laboratory or neuroimaging cause. We present an unusual case of a 42-year old woman with unilateral tremor of right extremities (mostly proximal part of upper extremity) which started abruptly 3 years ago. She had no suffer any serious disease before the onset of symptoms and her family history was also negative. The tremor was present at rest but accelerated during specific postures and active movements. The laboratory tests including: copper and ceruloplasmin concentrations, blood analysis for acanthocytes, evoked potentials, EEG, CT, MRI, MRA and SPECT did not reveal any significant changes. Treatment attempts with neuroleptics, clonazepam, L-dopa, valproic acid, biperiden were almost completely ineffective except local injections of botulinum toxin (Botox, Allergan, 150 U) into the muscles of right arm girdle which moderately alleviated tremor. We did not find any underlying pathology as a cause of tremor, clinically the same as symptomatic cases described in literature. We suggest the possibility of idiopathic origin of tremor in our case, although a very small size of lesion (f.i. ischaemic) could be undetectable in the described tests.

New photosensitizers for photodynamic therapy in gastroenterology.

Most applications of photodynamic therapy (PDT) in gastroenterology to date have used porfimer sodium as the photosensitizing agent. For destroying small lesions in the wall of the gastrointestinal tract in inoperable patients, it has proved to be most effective, but attempts to achieve circumferential mucosal ablation, as in the treatment of Barrett's esophagus, have led to a high incidence of strictures, and all patients have cutaneous photosensitivity, which can last up to three months. Two new photosensitizers are of particular interest to gastroenterologists. PDT with metatetrahydroxyphenyl chlorin produces a similar biological effect as PDT with porfimer sodium, but the light doses required are much smaller, and cutaneous photosensitivity lasts only two to three weeks. Further, it can be used with percutaneous light delivery to destroy localized pancreatic cancers. The photosensitizing agent 5-amino levulinic acid, converted in vivo into the photoactive derivative protoporphyrin IX, sensitizes the mucosa much more than the underlying layers. This makes it feasible to destroy areas of abnormal mucosa without damaging the underlying muscle and is, therefore, better for treating Barrett's esophagus. Detailed clinical studies are required to establish the real role of PDT with the use of these and other new photosensitizers.

[Primitive neuroectodermal tumor of rare localization in two members of one family]. / Przypadek PNET o rzadkiej lokalizacji u dwóch czlonków jednej rodziny.

A 26-year-old man with primitive neuroectodermal tumour (PNET) is reported. The tumour originated from the cervical spinal cord and was resected partially. Few months later dissemination of the tumour to the meninges occurred. Familial history revealed that the first daughter of the patient had died in age of 14 months three years earlier of a tumour of the right cerebral hemisphere, also diagnosed as PNET.

Chelating 2-mercaptobenzothiazole loaded resin. Application to the separation of inorganic and alkylmercury species for their atomic absorption spectrometry determination in natural waters.

A new 2-mercaptobenzothiazole loaded Bio-Beads SM-7 resin has been prepared and its analytical properties were established. The sorbent was applied to the separation and preconcentration of inorganic and alkylmercury from natural waters. Optimum conditions of separation as pH, flow rate on column, volume of samples and desorbing agent were established. The cold vapour atomic absorption method determination of both forms of mercury after their successive reduction by tin(II) was used. The low limit of determination for this method was established as 10 ng l(-1) for 1.0 l water sample. Accuracy and precision of the method was estimated by using test water standards and samples of natural water spiked with known amounts of mercury species.

[Alloimmune neonatal thrombocytopenia caused by serologic incompatibility of HPA-1a platelet antigen--case report]. / Alloimmunologiczna maloplytkowosc noworodka wywolana konfliktem serologicznym w zakresie antygenu plytkowego HPA-1 a--opis przypadku.

A case of newborn of the 7th pregnancy; 3rd delivery with NAIT is presented. We focus on the necessity of performing serological diagnostics of platelet antigens and antibodies if in the former neonate the thrombocytopenia of unknown etiology was observed or previous pregnancies resulted in natural abortion of unknown origin.