Popliteal lymph node dissection for metastatic squamous cell carcinoma: a case report of an uncommon procedure for an uncommon presentation

Lymph node metastasis from cutaneous squamous cell carcinoma is uncommon. The popliteal fossa is rarely involved with metastasis. Popliteal lymph node dissection is uncommonly performed and not frequently discussed in the literature. We present a case of squamous cell carcinoma of the heel with popliteal and inguinal metastasis. This is followed by a description of the relevant anatomy of the popliteal fossa and the technique of popliteal lymphadenectomy

Elicitation of Neutralizing Antibodies Directed against CD4-Induced Epitope(s) Using a CD4 Mimetic Cross-Linked to a HIV-1 Envelope Glycoprotein

The identification of HIV-1 envelope glycoprotein (Env) structures that can generate broadly neutralizing antibodies (BNAbs) is pivotal to the development of a successful vaccine against HIV-1 aimed at eliciting effective humoral immune responses. To that end, the production of novel Env structure(s) that might induce BNAbs by presentation of conserved epitopes, which are otherwise occluded, is critical. Here, we focus on a structure that stabilizes Env in a conformation representative of its primary (CD4) receptor-bound state, thereby exposing highly conserved “CD4 induced” (CD4i) epitope(s) known to be important for co-receptor binding and subsequent virus infection. A CD4-mimetic miniprotein, miniCD4 (M64U1-SH), was produced and covalently complexed to recombinant, trimeric gp140 envelope glycoprotein (gp140) using site-specific disulfide linkages. The resulting gp140-miniCD4 (gp140-S-S-M64U1) complex was recognized by CD4i antibodies and the HIV-1 co-receptor, CCR5. The gp140-miniCD4 complex elicited the highest titers of CD4i binding antibodies as well as enhanced neutralizing antibodies against Tier 1 viruses as compared to gp140 protein alone following immunization of rabbits. Neutralization against HIV-27312/V434M and additional serum mapping confirm the specific elicitation of antibodies directed to the CD4i epitope(s). These results demonstrate the utility of structure-based approach in improving immunogenic response against specific region, such as the CD4i epitope(s) here, and its potential role in vaccine application

Cutaneous lesions of the external ear

Skin diseases on the external aspect of the ear are seen in a variety of medical disciplines. Dermatologists, othorhinolaryngologists, general practitioners, general and plastic surgeons are regularly consulted regarding cutaneous lesions on the ear

Comparative evaluation of trimeric envelope glycoproteins derived from subtype C and B HIV-1 R5 isolates.

We previously reported that an envelope (Env) glycoprotein immunogen (o-gp140DeltaV2SF162) containing a partial deletion in the second variable loop (V2) derived from the R5-tropic HIV-1 isolate SF162 partially protected vaccinated rhesus macaques against pathogenic SHIV(SF162P4) virus. Extending our studies to subtype C isolate TV1, we have purified o-gp140DeltaV2TV1 (subtype C DeltaV2 trimer) to homogeneity, performed glycosylation analysis, and determined its ability to bind CD4, as well as a panel of well-characterized neutralizing monoclonal antibodies (mAb). In general, critical epitopes are preserved on the subtype C DeltaV2 trimer; however, we did not observe significant binding for the b12 mAb. The molecular mass of subtype C DeltaV2 trimer was found to be 450 kDa, and the hydrodynamic radius was found to be 10.87 nm. Our data suggest that subtype C DeltaV2 trimer binds to CD4 with an affinity comparable to o-gp140DeltaV2SF162 (subtype B DeltaV2 trimer). Using isothermal titration calorimetric (ITC) analysis, we demonstrated that all three CD4 binding sites (CD4-BS) in both subtype C and B trimers are exposed and accessible. However, compared to subtype B trimer, the three CD4-BS in subtype C trimer have different affinities for CD4, suggesting a cooperativity of CD4 binding in subtype C trimer but not in subtype B trimer. Negative staining electron microscopy of the subtype C DeltaV2 trimer has demonstrated that it is in fact a trimer. These results highlight the importance of studying subtype C Env, and also of developing appropriate subtype C-specific reagents that may be used for better immunological characterization of subtype C Env for developing an AIDS vaccine

Head and Neck Cutaneous Squamous Cell Carcinoma Requiring Parotidectomy

Objective Evaluate characteristics and risk factors for patients with advanced cutaneous squamous cell carcinoma (cSCC). Study Design Retrospective case series. Setting Tertiary care center. Patients and Methods Chart review of patients with cSCC undergoing a parotidectomy (2003-2012). Results Of 218 patients identified, 49% presented with a new primary lesion (n = 107) and 51% with a recurrence (n = 111). Parotid lymph nodes were positive in 52% of patients; 81% had a concurrent neck dissection, and 28% had cervical lymph node metastases. In 18% of patients, both parotid and cervical nodes were positive, while 44% were both parotid and cervical node negative; 33% had positive parotid and negative cervical nodes, and only 5% had negative parotid and positive cervical nodes. The overall 2- and 5-year survival rates were 0.71 and 0.58. Overall 5-year survival was lower for patients presenting with recurrent (0.49) versus new primary disease (0.69; P = .04). In addition, decreased overall 5-year survival rates were associated with cervical lymph node involvement (0.47 vs. 0.62; P = .01). There was no difference in overall survival when stratified by parotid lymph node involvement (P = .85), margin status (P = .67), perineural invasion (P = .42), facial nerve sacrifice (P = .92), or type of parotid operation performed (P = .51). Conclusions In this study, cervical, but not parotid, lymph node involvement was associated with poor outcomes in patients with advanced cSCC requiring a parotidectomy. In patients without evidence of cervical or parotid lymph node involvement, a neck dissection may be spared, given there is a 5% chance of occult disease