274 research outputs found
Capitale Naturale per i cittadini di oggi e le future generazioni
No full textIl paesaggio agricolo della pianura irrigua milanese ha subito un radicale cambiamento a causa della riduzione dei fondi agricoli, della crescita della città e dell’evoluzione delle tecniche agricole. La campagna ha subito una semplificazione e un impoverimento, con la perdita della diversità delle colture e della copertura vegetale. Questo ha portato alla perdita consistente del capitale naturale e delle funzioni ecosistemiche un tempo presenti. L’approccio del progetto Cascina Ca’ Granda prevede che l’agricoltura torni ad essere un’attività di cura del territorio: a questo scopo, occorre assumere un atteggiamento progettuale e di visione e rinunciare all’illusione di ritornare al passato o a conservare lo stato esistent
ANALYSIS OF MICRORNAS AND GENIC POLYMORPHISMS IN THE DIAGNOSIS OF NEOPLASTIC AND TRANSMISSIBLE DISEASES IN DOGS
No full textDuring my PhD, I mainly worked on two different fields of research:
1. Analysis of microRNAs in canine hematopoietic malignancies for diagnostic purposes. MicroRNAs (miRNAs) are a new class of small non-coding RNAs involved in the negative regulation of gene expression. In humans, it has been shown that miRNAs play a key role in the modulation of the innate immune response and in the regulation of normal and neoplastic hematopoiesis. The expression profile of these molecules varies in the different stages of differentiation of the hematopoietic system cellular components and any alteration of these processes is directly associated with dysregulation of one or more miRNAs. The frequency and nature of some of these tumors are similar in dogs and humans. In dog, the studies of hemato-oncology performed to date have shown that the currently used methodologies are not always able to obtain comprehensive information about the staging, grading, immunophenotyping and prognosis of the diseases. This makes miRNAs very attractive as new potential diagnostic and prognostic markers allowing better subclassification of these tumors in dogs. The purpose of the study undertaken in this project was to examine, using stem-loop TaqMan real time RT-PCR, the expression profile of a panel of miRNAs in some hematological malignancies of the dog, such as chronic lymphocytic leukemia (CLL), lymph node lymphoma and splenic lymphoma, in relation to their non cancer tissues. Panels of miRNAs, already known in humans because of their importance in hematopoietic malignancies, have been selected for investigation, according to the information available in the literature and databases, and to their level of conservation in the canine genome. As a preliminary step, for each studied canine neoplasia, an accurate validation of suitable candidate endogenous control (EC) genes for normalization of miRNA expression levels in normal and neoplastic lymphoid tissues was made. This was performed by means of real time RT-PCR followed by statistical analysis using the algorithms NormFinder and geNorm. In all studied lymphoid malignancies, and for each miRNA investigated, a relative quantification (by calculating the delta-delta Ct to the endogenous control gene selected) and an absolute quantification (interpolating its Ct value on standard curves obtained from serial dilutions of an equimolar pool of synthetic miRNAs) was performed after selecting the best housekeeping genes. The results of this study confirm that in dogs, as already shown in humans, there is differential expression of some miRNAs in various hematologic malignancies, suggesting the potential utility of miRNA monitoring as a new diagnostic strategy in canine hematopoietic malignancies. In particular, in lymph node lymphoma samples miR-181a was upregulated in canine T-cell lymphoma and miR-17-5p was upregulated in canine B-cell lymphoma. Moreover, the molar ratio between miR-181a and miR-17-5p clearly distinguished between T-cell and B-cell lymphoma samples. In CLL samples, the molar ratio miR-150/miR-125b was correlated with the immunophenotype. Finally, molar ratio miR-17-5p/miR-155 was correlated with grading in canine splenic lymphoma. Furthermore, in dogs is often difficult to obtain a sufficient number of fresh clinical samples to perform large diagnostic studies. From here the need arises to carry out studies of retrospective nature based on appropriately validated methods of analysis that make possible to analyze archival samples. Therefore, one of the goals of this study was to develop a methodology for extraction and analysis of miRNAs from smears of aspirated lymph node (for the study of lymph node lymphoma) and peripheral blood (for the study of CLL) and from tissue sections fixed in formalin and included in paraffin (for the study of splenic lymphoma). The results obtained during this study confirm the possibility to analyze miRNAs for retrospective studies starting from such archival samples, as the data obtained from these samples are comparable to those obtained from fresh samples.
2. High Resolution Melting Analysis (HRMA) of genic polymorphisms for diagnostic purposes. High Resolution Melting (HRM) analysis is a new, post-PCR analysis method used for identifying genetic variation in nucleic acid sequences. Simple and fast, this method is based on DNA melting (dissociation) curve techniques and is enabled by the recent availability of improved double-stranded DNA (dsDNA)–binding dyes along with next-generation real-time PCR instrumentation and analysis software. HRM analysis can discriminate DNA sequences based on their composition, length, GC content, or strand complementarity. Accordingly, HRMA allows the detection of multiple types of variations in DNA sequences such as single base changes, insertions, deletions and duplications. In this work this new methodology was utilized as a successful rapid diagnostic technique for the evaluation of the resistance to fluoroquinolones in Staphylococcus pseudintermedius isolates from canine clinical samples, and for the detection and discrimination of Dirofilaria immitis and Dirofilaria repens in canine peripheral blood
How long can stool samples be fixed for an accurate diagnosis of soil-transmitted helminth infection using mini-FLOTAC?
No full textKato-Katz is a widely used method for the diagnosis of soil-transmitted helminth infection. Fecal samples cannot be preserved, and hence, should be processed on the day of collection and examined under a microscope within 60 min of slide preparation. Mini-FLOTAC is a technique that allows examining fixed fecal samples. We assessed the performance of Mini-FLOTAC using formalin-fixed stool samples compared to Kato-Katz and determined the dynamics of prevalence and intensity estimates of soil-transmitted helminth infection over a 31-day time period.; The study was carried out in late 2013 on Pemba Island, Tanzania. Forty-one children were enrolled and stool samples were subjected on the day of collection to a single Kato-Katz thick smear and Mini-FLOTAC examination; 12 aliquots of stool were fixed in 5% formalin and subsequently examined by Mini-FLOTAC up to 31 days after collection.; The combined results from Kato-Katz and Mini-FLOTAC revealed that 100% of children were positive for Trichuris trichiura, 85% for Ascaris lumbricoides, and 54% for hookworm. Kato-Katz and Mini-FLOTAC techniques found similar prevalence estimates for A. lumbricoides (85% versus 76%), T. trichiura (98% versus 100%), and hookworm (42% versus 51%). The mean eggs per gram of stool (EPG) according to Kato-Katz and Mini-FLOTAC was 12,075 and 11,679 for A. lumbricoides, 1,074 and 1,592 for T. trichiura, and 255 and 220 for hookworm, respectively. The mean EPG from day 1 to 31 of fixation was stable for A. lumbricoides and T. trichiura, but gradually declined for hookworm, starting at day 15. The findings of our study suggest that for a qualitative diagnosis of soil-transmitted helminth infection, stool samples can be fixed in 5% formalin for at least 30 days. However, for an accurate quantitative diagnosis of hookworm, we suggest a limit of 15 days of preservation. Our results have direct implication for integrating soil-transmitted helminthiasis into transmission assessment surveys for lymphatic filariasis
Parasitic infections on the shore of Lake Victoria (East Africa) detected by Mini-FLOTAC and standard techniques.
No full textBACKGROUND:
Helminths and protozoa infections pose a great burden especially in developing countries, due to morbidity caused by both acute and chronic infection. The aim of our survey was to analyze the intestinal parasitic burden in communities from Mwanza region, Tanzania.
METHODS:
Subjects (n=251) from four villages on the South of Lake Victoria have been analyzed for intestinal parasites with direct smear (DS), formol-ether concentration method (FECM) and the newly developed Mini-FLOTAC technique; urinary schistosomiasis was also assessed in a subsample (n=151); symptoms were registered and correlation between clinic and infections was calculated by chi-squared test and logistical regression.
RESULTS:
Out of the subjects screened for intestinal and for urinary parasites, 87% (218/251) were found positive for any infection, 69% (174/251) carried a helminthic and 67% (167/251) a protozoan infection, almost half of them had a double or triple infection. The most common helminths were hookworms, followed by Schistosoma mansoni and Schistosoma haematobium. Among protozoa, the most common was Entamoeba coli followed by Entamoeba histolytica/dispar and Giardia intestinalis. Mini-FLOTAC detected a number of helminth infections (61.7%) higher than FECM (38.6%) and DS (17.9%). Some positive associations with abdominal symptoms were found and previous treatment was negatively correlated with infection.
CONCLUSION:
Despite the limited size of the examined population the current study indicates a high prevalence of intestinal parasitic infection in Bukumbi area, Tanzania, and Mini-FLOTAC showed to be a promising diagnostic tool for helminth infections. This high parasitic burden calls for starting a regular deworming programme and other preventive interventions in schools and in the community
"Freezing" parasites in pre-Himalayan region, Himachal Pradesh: Experience with mini-FLOTAC.
No full textBackground
Helminths and protozoa infections pose a great burden especially in developing, countries, due to morbidity caused both by acute and chronic infections. Data on distribution of intestinal parasitic infections among the native and expatriates populations in Himachal Pradesh are scarce. The aim of our survey was to analyze the intestinal parasitic burden in communities from Dharamsala, Kangra district, in clinical and public health settings. We also field-tested the mini- FLOTAC, an innovative diagnostic device.
Methods
Subjects referring to the Tibetan Delek Hospital for abdominal discomfort and all children of the Tibetan Primary School in Dharamsala were screened for intestinal parasitic infections with direct smear, formol-ether concentration (FEC) method and mini-FLOTAC, their clinical history was recorded, and correlations between clinical symptoms and infections analyzed.
Results
152 subjects were screened for intestinal parasites, of which 72 subjects in the outpatients department (OPD) (36 expatriates and 36 natives) and 80 in the school. 60% of schoolchildren and 57% of OPD patients were found positive for any infection, the most represented were protozoa infections (50%), whereas helminthic infections accounted only for 13% and 20% in OPD patients and schoolchildren, respectively. The most prevalent among helminths was Ascaris lumbricoides (11%). Giardia intestinalis was more present among schoolchildren than the OPD patients (20% vs 6%) and E. histolytica/dispar was more prevalent among the OPD patients (42%) than the school children (23%). Correlations were found between nausea and loose or watery stools and parasitic infections, particularly in expatriates, whereas schoolchildren, despite being as infected as adults, were completely asymptomatic. Mini-FLOTAC detected higher number of helminth infections whereas FEC method was more accurate for the diagnosis of protozoa.
Conclusions
This study presents an accurate snapshot of intestinal parasitic infections in Dharamsala, and their high prevalence calls for more awareness and control measures. Mini-FLOTAC is a promising and simple technique for the diagnosis of helminth infections
Ritmo idioventricolare ectopico persistente tipo ritardo di attivazione sinistra e conseguenti alterazioni della ripolarizzazione ventricolare in soggetti normali.
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