152 research outputs found
Gastrin and cholecystokinin peptide-based radiopharmaceuticals: an in vivo and in vitro comparison
The development of suitable radioligands for targeting CCK-2 receptor expressing tumors, such as medullary thyroid carcinoma, is of great clinical interest. In the search for the best CCK-2R binding peptides, we have synthesized, evaluated and compared the CCK8 peptide (Asp-Tyr-Met-Gly-Trp-Met-Asp-PheNH(2) ) and two gastrin analogs commonly referred to as MG0 (DGlu-Glu(5)-Ala-Tyr-Gly-Trp-Met-Asp-PheNH(2) ) and MG11 (DGlu(1)-Ala-Tyr-Gly-Trp-Met-Asp-PheNH(2) ). The N-terminal portion of the three peptide sequences was derivatized by introducing the DTPAGlu or DOTA chelators to allow radiolobeling with (111) In(III) and (68) Ga(III), respectively. Saturation binding and cellular internalization experiments were performed on A431 cells overexpressing CCK2R (A431-CCK2R). All compounds showed Kd values in the nM range and were internalized with similar rates in CCK2 receptor overexpressing cells. Biodistribution experiments showed higher specific uptake of both MG0-based compounds compared to conjugates containing the CCK8 and MG11 peptide sequences. The higher retention levels of MG0-based peptides were associated with markedly elevated and undesired kidney uptake compared to the other compounds. Current indications suggest that the 5 Glu N-terminal residues while improving peptide stability and receptor-mediated tumor uptake cause unacceptably high kidney retention. Although displaying lower absolute tumor uptake values, the DOTA-coupled CCK8 peptide provided the best tumor to kidney uptake ratio and appears more suitable as lead compound for improvement of radiopharmaceutical properties
The [Tc(N)(PNP)]2+ metal fragment labeled cholecystokinin-8 (CCK8) peptide for CCK-2 receptors imaging: in vitroand in vivo studies
The radiolabeling of the natural octapeptide CCK8, derivatized with a cysteine residue (Cys-Gly-CCK8), by using the metal fragment [99mTc(N)(PNP3)]2+ (PNP3 = N,N-bis(dimethoxypropylphosphinoethyl)methoxyethylamine) is reported. The [99mTc(N)(NS-Cys-Gly-CCK8)(PNP3)]+ complex was obtained according to two methods (one-step or two-step procedure) that gave the desired compound in high yield. The complex is stable in aqueous solution and in phosphate buffer. In vitro challenge experiments with an excess of cysteine and glutathione indicate that no transchelation reactions occur, confirming the high thermodynamic stability and kinetic inertness of this compound. Stability studies carried out in human and mouse serum, as well as in mouse liver homogenates, show that the radiolabeled compound remains intact for prolonged incubation at 37 degrees C. Binding properties give Kd (19.0 +/- 4.6 nmol/l) and Bmax (approximately 10(6) sites/cell) values in A431 cells overexpressing the CCK2-R. In vivo evaluation of the compound shows rapid and specific targeting to CCK2-R, a fourfold higher accumulation compared to nonreceptor expressing tumors
Transoral robotic surgery in head and neck district: A retrospective study on 67 patients treated in a single center
Background: The anatomical complexity of the oropharynx and the difficulty in reaching its distal portion have always conditioned the surgical accessibility. Robotic surgery represents an excellent alternative in the treatment of cervico-facial oncological diseases. Methods: This series comprises all patients managed for head and neck cancer by Trans Oral Robotic Surgery TORS. The staging assessment, including neck ultrasound and total body PET/CT scan, was performed in each patient according to the TNM classification. All charts were recorded with the following data: name and surname, age, gender, date of surgery intra or post-operative hemorragia, tumor site, histology, TNM stage, robot set-up time, tumor resection time, whether or not tracheotomy was performed, whether or not neck dissection was performed, insertion of a nasogastric tube or gastrostomy, time to resumption of oral feeding, surgical margins, mean length of hospital stay, adjuvant treatment and follow-up. Results: From February 2013 to February 2018, TORS was performed in 67 consecutive patients affected by head and neck tumours. We divided, our sample, in 3 subsites: supraglottic larynx, parapharyngeal space and oropharynx. Pathology reports confimed malignancy in 44 cases: 8 cases lymphomas, 36 cases of Squamous cell carcinoma (SCC), 5 cases of benign salivary glands tumors and 18 miscellaneous cases. Neck dissection was performed in 12 cases. Tracheotomy was perfomed in 3/67 cases for respiratory failures. A nasogastric tube was inserted at the end of the surgical procedure in 21 patients. The mean length of hospital stay was 10 days. Major complications included post-operative bleeding in 3 patients, 1 exitus for massive bleeding 20 days post-surgery and 1 respiratory failure treated with tracheotomy and monitoring in the Intensive Care Unit (ICU) for 3 days. Conclusions: Robotic surgery has been considered a valid alternative to traditional open treatment in many specializations with the advantages of an endoscopic procedure, with the same oncological and functional results and with fewer complications. The advantages of this type of surgical technique have been discussed, it is mandatory to focus on the indications and contraindications
Molecular and phylogenetic analysis of HIV-1 variants circulating in Italy
<p>Abstract</p> <p>Objective</p> <p>The continuous identification of HIV-1 non-B subtypes and recombinant forms in Italy indicates the need of constant molecular epidemiology survey of genetic forms circulating and transmitted in the resident population.</p> <p>Methods</p> <p>The distribution of HIV-1 subtypes has been evaluated in 25 seropositive individuals residing in Italy, most of whom were infected through a sexual route during the 1995–2005 period. Each sample has been characterized by detailed molecular and phylogenetic analyses.</p> <p>Results</p> <p>18 of the 25 samples were positive at HIV-1 PCR amplification. Three samples showed a nucleotide divergence compatible with a non-B subtype classification. The phylogenetic analysis, performed on both HIV-1 <it>env </it>and <it>gag </it>regions, confirms the molecular sub-typing prediction, given that 1 sample falls into the C subtype and 2 into the G subtype. The B subtype isolates show high levels of <it>intra</it>-subtype nucleotide divergence, compatible with a long-lasting epidemic and a progressive HIV-1 molecular diversification.</p> <p>Conclusion</p> <p>The Italian HIV-1 epidemic is still mostly attributable to the B subtype, regardless the transmission route, which shows an increasing nucleotide heterogeneity. Heterosexual transmission and the interracial blending, however, are slowly introducing novel HIV-1 subtypes. Therefore, a molecular monitoring is needed to follow the constant evolution of the HIV-1 epidemic.</p
AIDS-Kaposi Sarcoma and Classic Kaposi Sarcoma: are different ultrasound patterns related to different variants?
<p>Abstract</p> <p>Background</p> <p>Kaposi Sarcoma (KS) is a malignancy of endothelial skin cells with multifocal localization on the skin, lymph nodes and visceral organs. Although all clinical variants are associated with HHV-8 infection, specific differences in the clinical onset and in the natural history of AIDS-KS and Classic-KS have been described. The present randomised prospective-observational study aimed to investigate whether the ultrasound pattern and color Doppler flow imaging of vascularisation of skin lesions of patients with Classic KS (CKS) or AIDS-KS could provide useful information to the evaluation of clinical activity of the disease.</p> <p>Methods</p> <p>Cutaneous lesions of 24 patients with histologically confirmed KS were investigated using very high frequency ultrasound probes; 16 patients had CKS and 8 had AIDS-KS. HHV-8 infection was confirmed in all patients by investigating the specific humoral response to viral antigens. Immunological and virological parameters were also assessed to monitor HIV or HHV-8 viral infection. For each patient, a target skin lesion was selected on the basis of size (diameter from 0.4 to 2 cm). Each lesion was analyzed in terms of size, depth and color Doppler pattern.</p> <p>Results</p> <p>The B-mode ultrasound patterns of skin lesions did not differ when comparing CKS patients to AIDS-KS patients, whereas the color Doppler signal, which is associated with vascular activity, was detected in the KS lesions of 6/8 AIDS-KS patients (75.0%) and in 2/16 CKS (16,7%); the latter two patients showed a clinically progressive and extensive disease stage (IV B).</p> <p>Conclusions</p> <p>Our preliminary results suggest that small cutaneous KS lesions - in both CKS and AIDS-KS patients- display similar B-mode ultrasound patterns ( hypoechoic, well defined, superficial lesions). However, the color Doppler signal, which is associated with endothelial activity and angiogenesis, which play a substantial role in KS progression, could constitute a useful tool for evaluating disease activity.</p
Pediatric Intensive Care Unit admission criteria for haemato-oncological patients: a basis for clinical guidelines implementation
Recent advances in supportive care and progress in the development and use of chemotherapy have considerably improved the prognosis of many children with malignancy, thus the need for intensive care admission and management is increasing, reaching about 40% of patients throughout the disease course. Cancer remains a major death cause in children, though outcomes have considerably improved over the past decades. Prediction of outcome for children with cancer in Pediatric Intensive Care Unit (PICU) obviously requires clinical guidelines, and these are not well defined, as well as admission criteria. Major determinants of negative outcomes remain severe sepsis/septic shock association and respiratory failure, deserving specific approach in children with cancer, particularly those receiving a bone marrow transplantation. A nationwide consensus should be achieved among pediatric intensivists and oncologists regarding the threshold clinical conditions requiring Intensive Care Unit (ICU) admission as well as specific critical care protocols. As demonstrated for the critically ill non-oncologic child, it appears unreasonable that pediatric patients with malignancy can be admitted to an adult Intensive Care Unit ICU. On a national basis a pool of refecence institutions should be identified and early referral to an oncologic PICU is warranted
The impact of antiretroviral therapy on HPV and cervical intraepithelial neoplasia: current evidence and directions for future research
Increasing numbers of human immunodeficiency virus (HIV)-infected women are now accessing life-prolonging highly active antiretroviral therapy (HAART) in developing countries. There is a need for better understanding of interactions of human papillomavirus (HPV) and HIV, especially in the context of increasing life expectancy due to HAART. The data regarding the impact of HAART on reducing the incidence and progression and facilitating the regression of HPV infection and cervical abnormalities is largely inconsistent. Published studies differ in their study designs (prospective or retrospective cohorts or record linkage studies), screening and diagnostic protocols, duration and type of HAART use, recruitment and referral strategies, and definitions of screening test and disease positivity. Due to the ethical and resource limitations in conducting randomized trials of the impact of HAART on incidence of HPV, CIN, and cervical cancer among HIV-infected women, it is important to consider innovative study designs, including quasi-experimental trials and operations research in sentinel populations to answer the critical research questions in this area
Immune signatures in human PBMCs of idiotypic vaccine for HCV-related lymphoproliferative disorders
Hepatitis C virus (HCV) is one of the major risk factors for chronic hepatitis, which may progress to cirrhosis and hepatocellular carcinoma, as well as for type II mixed cryoglobulinemia (MC), which may further evolve into an overt B-cell non-Hodgkin's lymphoma (NHL)
Prevalence of human papillomavirus infection in women in Benin, West Africa
<p>Abstract</p> <p>Background</p> <p>Cervical cancer ranks as the first most frequent cancer among women in Benin. The major cause of cervical cancer now recognized is persistent infection of Human Papillomavirus (HPV). In Benin there is a lack of screening programs for prevention of cervical cancer and little information exists regarding HPV genotype distribution.</p> <p>Methods</p> <p>Cervical cells from 725 women were examined for the presence of viral DNA by means of a polymerase chain reaction (PCR) multiplex-based assay with the amplification of a fragment of L1 region and of E6/E7 region of the HPV genome, and of abnormal cytology by Papanicolaou method. The association between HPV status and Pap test reports was evaluated. Socio-demographic and reproductive characteristics were also related.</p> <p>Results</p> <p>A total of 18 different HPV types were identified, with a prevalence of 33.2% overall, and 52% and 26.7% among women with and without cervical lesions, respectively. Multiple HPV infections were observed in 40.2% of HPV-infected women. In the HPV-testing group, the odds ratio for the detection of abnormal cytology was 2.98 (95% CI, 1.83-4.84) for HPV positive in comparison to HPV negative women. High risk types were involved in 88% of infections, most notably HPV-59, HPV-35, HPV-16, HPV-18, HPV-58 and HPV-45. In multiple infections of women with cytological abnormalities HPV-45 predominated.</p> <p>Conclusions</p> <p>This study provides the first estimates of the prevalence of HPV and type-specific distribution among women from Benin and demonstrates that the epidemiology of HPV infection in Benin is different from that of other world regions. Specific area vaccinations may be needed to prevent cervical cancer and the other HPV-related diseases.</p
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