A novel approach to cancer screening using the nematode Caenorhabditis elegans-based detection assays.

BACKGROUND: Early diagnosis of cancer is essential for its effective treatment. Currently, established screening tests are cancer-specific and require screening for each type of cancer separately. The primary objective of cancer research is to develop methods that can detect multiple types of tumors from a single body fluid sample. Multicancer early detection tests aim to detect fragments of circulating tumor DNA, cell-free DNA, circulating microRNAs, or proteins released by cancer cells in the patient's body fluids. However, these tests are not suitable for routine cancer prevention due to their high cost. Therefore, in recent years, cancer screening tests have been developed to detect volatile organic compounds in urine using living organisms, such as nematodes, Caenorhabditis elegans. Measuring only 1 mm in length, C. elegans has the potential to offer a new, efficient, cost-effective, quick, and painless method to detect the presence of tumor. PURPOSE: The purpose of this review is to present an overview of the literature on the development and validation of C. elegans-based cancer detection methods. The potential benefits of these assays are significant, as they could become a valuable tool for the early identification and diagnosis of cancer, even though this research is still in its initial stages of development.

The prevalence of methicillin-resistant Staphylococcus aureus among nursing home residents for the elderly in Slovakia.

The objective of our study was to examine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) among residents of nursing homes for the elderly of selected institutions in two Slovak regions compared to non-institutionalized volunteers of the same age, as well as young volunteers (20-24 years old). Nasal swabs from all participants (n = 424) were processed using standard methods for the isolation and identification of S. aureus and MRSA. Statistically significant differences were found between nursing home residents and young volunteers (12% vs. 1.5%; OR 8.85; 95% CI 2.087-37.706; p = 0.0007), as well as between non-institutionalized seniors and young volunteers (11% vs. 1.5%; OR 8; 95% CI 1.888-33.901; p = 0.005) in the prevalence of MRSA. Our results suggest that nursing home residency and older age could be a risk factor for the occurrence of high-risk MRSA strains.

Applications of a powerful model organism Caenorhabditis elegans to study the neurotoxicity induced by heavy metals and pesticides.

The expansion of industry and the use of pesticides in agriculture represent one of the major causes of environmental contamination. Unfortunately, individuals and animals are exposed to these foreign and often toxic substances on a daily basis. Therefore, it is crucial to monitor the impact of such chemicals on human health. Several in vitro studies have addressed this issue, but it is difficult to explore the impact of these compounds on living organisms. A nematode Caenorhabditis elegans has become a useful alternative to animal models mainly because of its transparent body, fast growth, short life cycle, and easy cultivation. Furthermore, at the molecular level, there are significant similarities between humans and C. elegans. These unique features make it an excellent model to complement mammalian models in toxicology research. Heavy metals and pesticides, which are considered environmental contaminants, are known to have affected the locomotion, feeding behavior, brood size, growth, life span, and cell death of C. elegans. Today, there are increasing numbers of research articles dedicated to this topic, of which we summarized the most recent findings dedicated to the effect of heavy metals, heavy metal mixtures, and pesticides on the well-characterized nervous system of this nematode.

Urinary Schistosomosis in Patients of Rural Medical Health Centers in Kwale County, Kenya.

Urinary schistosomosis is a serious public health problem prevalent in low-income rural regions of sub-Saharan Africa, including coastal part of Kenya. Praziquantel administration to school-aged children is the prevailing tool of schistosomosis control in these regions. The aim of our study was to find out if this control strategy can lead to interruption of parasite trasmission and disease elimination. During February and March 2018, the occurrence of urinary schistosomosis in volunteers of primary health care facilities in Kwale County, Kenya was examined and the occurrence of infected intermediate hosts Bulinus globosus in local water resources was monitored. Participants completed a questionnaire concerning source of water for household purposes, type of housing and health status and were asked to provide urine samples. Diagnosis of urinary schistosomosis was established by detection of Schistosoma haematobium eggs in urine specimens microscopically, using filtration method. Infected B. globosus snails were detected using cercaria shedding tests. From the hemolymph of snails, prepatent period of infection was identified by polymerase chain reaction (PCR). The presence of urinary schistosomosis was detected in 15.07 % (69 out of 451) of study participants. Cercaria shedding test was positive in 2 particular sites of river Pengo and Tsanganyiko. Genetic material (haemolymph) of 68 B. globosus snails tested by DraI PCR revealed 7 Schistosoma spp. positive samples. Six of seven DraI positive snails were infected by S. haematobium, as it was detected by Sh110/SmS1 PCR. The study revealed, that the disease was still present in the region studied and the transmission was not interrupted. The rate of infection was significantly influenced by the water supplies used for household purposes and the type of housing.

Lactate dehydrogenase activity in human placenta following exposure to environmental pollutants.

The impact of environmental pollution at the place of residence of pregnant women and of their smoking habits on the cellular energy metabolism of placental tissue was investigated. Samples of full-term placentas were randomly collected from two environmentally different regions of Slovakia (Bratislava, Stará Lubovna) and the activity of lactate dehydrogenase (LDH) was measured. Our results showed enhanced LDH activity in the placenta that was dependent on both the type of environmental pollutants at the place of residence and the smoking habits during pregnancy. The enhanced LDH activity may reflect hypoxic conditions due to the accumulation of heavy metals and toxic compounds of tobacco smoke in the placental tissue. A high content of heavy metal particles, found in placental samples from Stará Lubovna in our previous studies, might contribute to the increased LDH activity in placentas from this region. We hypothesize that fine metal particles deposited in the placental tissue might be phagocytozed by the syncytiotrophoblast, thus contributing to the decreased oxygen level in placental tissue.

Impact of acute and subchronic asbestos exposure on some parameters of antioxidant defense system and lung tissue injury.

Asbestos fibers have been used in industry for decades. Deleterious effect of asbestos on the lungs has been documented. However, the mechanism of asbestos related diseases has not been fully explained yet. Numerous papers suggest there is a role of reactive oxygen intermediates (ROI) in asbestos-induced lung disease development. The excess ROI produced can be removed from the lungs by enzymatic and nonenzymatic antioxidants. The aim of our study was to compare the levels of antioxidants (ascorbic acid, retinol, alpha-tocopherol, glutathionperoxidase) as well as some markers of lung injury (lipid peroxides, total amount of protein, alkaline phosphatase) in asbestos treated Wistar-rats both 24 hr and 3 months after exposure to those in the controls, and to find out if the changes in antioxidant levels could affect impairment of the lungs. Decreased levels of antioxidants and increased values of lung tissue injury parameters in exposed groups suggest involvement of ROI in the mechanism of asbestos lung disease development, resulting in lung tissue injury, both 24 hr and 3 months after exposure.

Some bronchoalveolar lavage parameters and leukocyte cytokine release in response to intratracheal instillation of short and long asbestos and wollastonite fibres in rats.

We investigated the differences between the lavage parameters -- including tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) release by lavage leukocytes -- in control rats and in animals intratracheally instilled with short and long amosite and wollastonite fibres. These cytokines can play an important role in lung disease development after long-term exposure to some fibrous dusts. Short and long amosite and wollastonite fibres were intratracheally instilled in rats (1 mg/week) for ten weeks while saline was given to controls. To compare the harmful effects of these fibres, the number of leukocytes/ml of bronchoalveolar lavage (BAL), the number of alveolar macrophages (AM) per ml of BAL, AM:granulocyte (GR) ratios in lavage fluid, phagocytic activity and viability of AM, lactate dehydrogenase (LDH), acid phosphatase (AcP), and TNF-alpha and IFN-gamma release by lavage leukocytes were investigated 3 months after the first intratracheal instillation. Compared with the controls, amosite short fibres significantly decreased the numbers of AM/ml BAL, and increased their phagocytic activity and AcP release. Long amosite fibres significantly decreased the numbers of AM/ml BAL, increased the number of granulocytes depressed the phagocytic activity and viability of AM, and significantly decreased the levels of TNF-alpha and IFN-gamma in supernatants of cultured leukocytes. While wollastonite short and long fibre instillation did not significantly influence the parameters studied (except for a significantly increased number of leukocytes/ml BAL in wollastonite long fibres), amosite short and long fibres caused marked differences in these parameters, the long fibres being more effective.

The changes of some immunological parameters in subjects exposed to asbestos in dependence on age, duration of exposure, radiological findings and smoking habits.

We followed the changes in some parameters in men exposed to asbestos (to chrysotile and in part to crocidolite). The studied group consisted of exposed workers and retired workers who had been exposed to asbestos in the past. The results were compared with those in the control group of unexposed adults and analysed according to age, duration of exposure, smoking habits and radiological findings. Investigated were: the levels of immunoglobulins IgA, IgG, IgM, complement components C3, C4, alpha-1-antitrypsin and transferrin (humoral immunity) as well as the phagocytic activity of the leukocytes in peripheral blood (natural immunity). The comparison of the results with those in the control group showed that asbestos exposure stimulated markedly IgG and C4 production and to a lesser extent also IgA, IgM, C3 and transferrin production and it suppressed natural immunity. Comparison of the results of the same age categories--control (40.8), with the subgroup of active workers (44.4), showed significantly increased levels of IgA, IgG, IgM, C4 and decreased values of natural immunity in asbestos exposed group. Comparison of different age categories (pensioners--63.2: workers--44.4) showed, that from five parameters in which statistically significant differences were found, four had decreased values in pensioners. Radiological findings suggested, that changes in immunological parameters probably preceded pathologic processes. There were statistically significant differences in the levels of IgM in smokers compared with nonsmokers in the subgroup of workers exposed to asbestos and in the levels of IgG and C4 in the group of workers + pensioners together. It follows from the present study that asbestos exposure modulates the immune response and leads to significant changes of humoral and natural immunity.