90 research outputs found

    T-cell responses to human papillomavirus type 16 among women with different grades of cervical neoplasia

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    Infection with high-risk genital human papillomavirus (HPV) types is a major risk factor for the development of cervical intraepithelial neoplasia (CIN) and invasive cervical carcinoma. The design of effective immunotherapies requires a greater understanding of how HPV-specific T-cell responses are involved in disease clearance and/or progression. Here, we have investigated T-cell responses to five HPV16 proteins (E6, E7, E4, L1 and L2) in women with CIN or cervical carcinoma directly ex vivo. T-cell responses were observed in the majority (78%) of samples. The frequency of CD4+ responders was far lower among those with progressive disease, indicating that the CD4+ T-cell response might be important in HPV clearance. CD8+ reactivity to E6 peptides was dominant across all disease grades, inferring that E6-specific CD8+ T cells are not vitally involved in disease clearance. T-cell responses were demonstrated in the majority (80%) of cervical cancer patients, but are obviously ineffective. Our study reveals significant differences in HPV16 immunity during progressive CIN. We conclude that the HPV-specific CD4+ T-cell response should be an important consideration in immunotherapy design, which should aim to target preinvasive disease

    Organ preservation surgery for laryngeal cancer

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    The principles of management of the laryngeal cancer have evolved over the recent past with emphasis on organ preservation. These developments have paralleled technological advancements as well as refinement in the surgical technique. The surgeons are able to maintain physiological functions of larynx namely speech, respiration and swallowing without compromising the loco-regional control of cancer in comparison to the more radical treatment modalities. A large number of organ preservation surgeries are available to the surgeon; however, careful assessment of the stage of the cancer and selection of the patient is paramount to a successful outcome. A comprehensive review of various organ preservation techniques in vogue for the management of laryngeal cancer is presented

    Evaluation of 'see-see and treat' strategy and role of HIV on cervical cancer prevention in Uganda

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    <p>Abstract</p> <p>Background</p> <p>There is scant information on whether Human Immunodeficiency Virus (HIV) seropositivity has an influence on the outcome of treatment of precancerous cervical lesions using cryotherapy. We studied the prevalence of cervical abnormalities detectable by visual inspection and cervical lesions diagnosed by colposcopy according to HIV serostatus and described the outcomes of cryotherapy treatment.</p> <p>Methods</p> <p>Trained nurses examined women not previously screened for cervical cancer using visual inspection with acetic acid (VIA) and Lugol's iodine (VILI) in two family planning/post natal clinics in Kampala, Uganda, from February 2007 to August 2008. Women with abnormal visual inspection findings were referred for colposcopic evaluation and HIV testing. Women with precancerous cervical lesions detected at colposcopy were treated mainly by cryotherapy, and were evaluated for treatment outcome after 3 months by a second colposcopy.</p> <p>Results</p> <p>Of the 5 105 women screened, 834 presented a positive screening test and were referred for colposcopy. Of these 625 (75%) returned for the colposcopic evaluation and were tested for HIV. For the 608 (97.5%) women in the age range 20-60 years, colposcopy revealed 169 women with cervical lesions: 128 had inflammation, 19 had low grade squamous intraepithelial lesion (LGSIL), 13 had high grade squamous intraepithelial lesion (HGSIL), 9 had invasive cervical cancer and 2 had inconclusive findings. Detection rates per 1 000 women screened were higher among the older women (41-60 years) compared to women aged 20-40 years. They were accordingly 55% and 20% for inflammation, 10% and 2% for LGSIL, 5% and 2% for HGSIL, 6% and 1% for invasive cervical cancer.</p> <p>Of the 608 women, 103 (16%) were HIV positive. HIV positivity was associated with higher likelihood of inflammation (RR = 1.7; 95% CI: 1.2-2.4).</p> <p>Conclusions</p> <p>Detection rates were higher among older women 41-60 years. Visual inspection of the cervix uteri with acetic acid (VIA) and Lugol's iodine (VILI) used as a sole method for cervical cancer screening would entail significant false positive results. HIV seropositivity was associated with a higher prevalence of inflammatory cervical lesions. In view of the small numbers and the relatively short follow up time of 3 months, we could not make an emphatic conclusion about the effect of HIV serostatus on cryotherapy treatment outcome.</p

    Interaction between polymorphisms of the Human Leukocyte Antigen and HPV-16 Variants on the risk of invasive cervical cancer

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    <p>Abstract</p> <p>Background</p> <p>Persistent infection with oncogenic types of human papillomavirus (HPV) is the major risk factor for invasive cervical cancer (ICC), and non-European variants of HPV-16 are associated with an increased risk of persistence and ICC. HLA class II polymorphisms are also associated with genetic susceptibility to ICC. Our aim is to verify if these associations are influenced by HPV-16 variability.</p> <p>Methods</p> <p>We characterized HPV-16 variants by PCR in 107 ICC cases, which were typed for <it>HLA-DQA1</it>, <it>DRB1 </it>and <it>DQB1 </it>genes and compared to 257 controls. We measured the magnitude of associations by logistic regression analysis.</p> <p>Results</p> <p>European (E), Asian-American (AA) and African (Af) variants were identified. Here we show that inverse association between <it>DQB1*05 </it>(adjusted odds ratio [OR] = 0.66; 95% confidence interval [CI]: 0.39–1.12]) and HPV-16 positive ICC in our previous report was mostly attributable to AA variant carriers (OR = 0.27; 95%CI: 0.10–0.75). We observed similar proportions of <it>HLA DRB1*1302 </it>carriers in E-P positive cases and controls, but interestingly, this allele was not found in AA cases (p = 0.03, Fisher exact test). A positive association with <it>DRB1*15 </it>was observed in both groups of women harboring either E (OR = 2.99; 95% CI: 1.13–7.86) or AA variants (OR = 2.34; 95% CI: 1.00–5.46). There was an inverse association between <it>DRB1*04 </it>and ICC among women with HPV-16 carrying the 350T [83L] single nucleotide polymorphism in the <it>E6 </it>gene (OR = 0.27; 95% CI: 0.08–0.96). An inverse association between <it>DQB1*05 </it>and cases carrying 350G (83V) variants was also found (OR = 0.37; 95% CI: 0.15–0.89).</p> <p>Conclusion</p> <p>Our results suggest that the association between HLA polymorphism and risk of ICC might be influenced by the distribution of HPV-16 variants.</p

    Tetrabenzoporphyrin and -mono-, - Cis -di- and tetrabenzotriazaporphyrin derivatives: Electrochemical and spectroscopic implications of meso CH Group replacement with nitrogen

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    Nonperipherally hexyl-substituted metal-free tetrabenzoporphyrin (2H-TBP, 1a) tetrabenzomonoazaporphyrin (2H-TBMAP, 2a), tetrabenzo-cis-diazaporphyrin (2H-TBDAP, 3a), tetrabenzotriazaporphyrin (2H-TBTAP, 4a), and phthalocyanine (2H-Pc, 5a), as well as their copper complexes (1b-5b), were synthesized. As the number of meso nitrogen atoms increases from zero to four, Îmax of the Q-band absorption peak becomes red-shifted by almost 100 nm, and extinction coefficients increased at least threefold. Simultaneously the blue-shifted Soret (UV) band substantially decreased in intensity. These changes were related to the relative electron-density of each macrocycle expressed as the group electronegativity sum of all meso N and CH atom groups, ñχR. X-ray photoelectron spectroscopy differentiated between the three different types of macrocyclic nitrogen atoms (the Ninner, (NH)inner, and Nmeso) in the metal-free complexes. Binding energies of the Nmeso and Ninner,Cu atoms in copper chelates could not be resolved. Copper insertion lowered especially the cathodic redox potentials, while all four observed redox processes occurred at larger potentials as the number of meso nitrogens increased. Computational chemical methods using density functional theory confirmed 1b to exhibit a Cu(II) reduction prior to ring-based reductions, while for 2b, Cu(II) reduction is the first reductive step only if the nonperipheral substituents are hydrogen. When they are methyl groups, it is the second reduction process; when they are ethyl, propyl, or hexyl, it becomes the third reductive process. Spectro-electrochemical measurements showed redox processes were associated with a substantial change in intensity of at least two main absorbances (the Q and Soret bands) in the UV spectra of these compounds

    ICAR: endoscopic skull‐base surgery

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    Immunoregulatory dysfunctions in type I diabetes: Natural and antibody-dependent cellular cytotoxic activities

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    Peripheral blood lymphocytes from 13 patients with established insulin-dependent diabetes mellitus (IDDM) and 2 prediabetic patients were examined for natural killer (NK) and antibody-dependent cellular cytotoxic activities (ADCC), lectin-dependent cellular cytotoxicity (LDCC), interferon- and interleukin-2-induced cytotoxicity, and concanavalin A-induced suppressor-cell activities in comparison with age-matched normal controls. IDDM patients demonstrated normal levels of NK and ADCC activities against K562 and antibody-coated SB target cells, respectively, compared to controls. IDDM patients showed normal levels of LDCC activity. Notable deviations from control values were, however, observed with diabetic lymphocytes in the following systems. Interferon-and interleukin-2-induced NK activities were significantly higher with IDDM lymphocytes than with control cells. IDDM lymphocytes precultured with concanavalin A demonstrated lower NK and ADCC activities than control cells and manifested decreased suppressor effects on the NK activity of normal allogeneic lymphocytes. Lymphocytes from one of two prediabetic patients showed increased NK, ADCC, and LDCC activities in comparison to controls. The increased interferon- and interleukin-2-induced enhancement of NK activity and reduced suppressor activity of lymphocytes from IDDM patients may be involved in the pathogenesis of the disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44848/1/10875_2004_Article_BF00915375.pd
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