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The recent coronavirus disease 19 (COVID-19) crisis has resulted in an economic downturn and the implementation of policies such as social distancing and shelter-in-place.1 In light of these events, the US government has passed the Coronavirus Preparedness and Response Supplemental Appropriations Act. This act relaxed Health Insurance Portability and Accountability Act regulations and instituted new avenues of revenue for telehealth, including (1) real-time audio-video technology communication; (2) store-and-forward technology, which collects data to be later transmitted via virtual check-ins, email, or other digital applications; and (3) verbal/audio-only communication without images or prerecorded videos.2 Moreover, latest polls have found that around two-thirds of patients are willing to try telehealth because of the pandemic.3 These factors have allowed physicians to provide virtual care for patients who are receptive to such technology while adhering to newly instituted policies. The various treatment options for keratinocyte carcinomas (KCs)—surgery, radiation, lasers, curettage and electrodesiccation, photodynamic therapy, intralesional chemotherapy, and cryotherapy—require in-person office visits for implementation.4 Currently, effective treatment options for KCs that allow for entirely no in-person visits are unknown or limited. The combination of topical antitumor agents (imiquimod 5% cream [IMI], 5-fluorouracil 2% solution [5-FU], and tretinoin 0.1% cream [TRET]) with limited cryotherapy was found to be efficacious in the treatment of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC).5 With the recent institution of social distancing, we evaluated the use of store-and-forward technology with this combination (IMI/5-FU/TRET) for the treatment of KCs that required no in-office patient visits.

Background/purpose Platelet-rich fibrin (PRF) can be obtained by centrifuging fresh blood in the absence of anticoagulants. Varying the centrifugation speeds may produce tougher and richer concentrated growth factors (CGF). This study examines tensile strength, growth factor content, and the potential of CGF and PRF in promoting periodontal cell proliferation. Materials and methods Blood (40 mL/subject) was collected from 44 healthy subjects. PRF and CGF were prepared by centrifuging at 3000 rpm and switching speeds ranging within 3000 rpm, respectively. Fibrin strip was prepared and its tensile strength was measured. Transforming growth factor beta 1 (TGF-β1), platelet-derived growth factor BB (PDGF-BB), and epidermal growth factor (EGF) in the residual serum and fibrin clots were determined by enzyme-linked immunosorbent assay, and their effects on the proliferation of hFOB1.19 osteoblasts and human gingival fibroblasts were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Results Compared with PRF, tensile strength of CGF was significantly higher. Concentrations and amounts of PDGF-BB and EGF in CGF were significantly higher than those in PRF. Osteoblast number was significantly higher in the cultures with fetal bovine serum (FBS, 10%) and with PRF or CGF fibrin clots (5%, 10%, and 50%) compared to that without FBS. Moreover, osteoblast number in CGF, regardless of the preparation of 10% and 50%, was significantly greater than that in PRF. Similar findings were also observed for gingival fibroblasts among the various subjects. Conclusion Varying centrifugation speeds can modify the tensile strength and biological activities of platelet fibrin clots.

Introduction: Standard of care for squamous cell carcinoma (SCC) is usually surgical, with either excision or Mohs micrographic surgery. However, surgery may not be ideal for elderly patients with numerous lesions, who are poor surgical candidates or who refuse surgery. Topical 5-fluorouracil (5-FU) and imiquimod have been studied off-label as monotherapies in the treatment of SCC in situ with promising results. However, long-term tumor-free survival rates are still less than with surgical management. Methods: We report a case of biopsy-proven invasive SCC in an 86-year-old Caucasian male with history of multiple actinic keratoses and no previous skin cancers. The patient declined surgical treatment due to concerns about cosmetic outcomes. A combination of topical 5% imiquimod cream, 2% 5-FU solution, and 0.1% tretinoin cream was used five nights per week under occlusion for a treatment goal of 30 total applications. The patient was evaluated in clinic every 2 weeks during which the site was treated with cryotherapy. The patient reported burning pain associated with treatment and only completed 24 of the 30 applications. Results: Follow-up biopsy 15 months after completing topical treatment revealed dermal scar with no evidence of residual carcinoma. Conclusion: Topical combination therapy with imiquimod, 5-FU, and tretinoin with intermittent, brief cryotherapy effectively treated a small, invasive SCC in this select patient who deferred surgery. Prospective randomized-controlled clinical trials to assess the role of combination topical treatment for invasive SCCs are warranted. J Drugs Dermatol. 2020;19(2)202-204. doi:10.36849/JDD.2020.2228

Background Minimally invasive alternative approaches to treat non-melanoma skin cancers remain limited and unproven. Objective We aim to assess the efficacy of varying combinations of anti-tumor agentsmimiquimod 5% cream, 5-fluorouracil 2% solution, and tretinoin 0.1% creammwith brief cryotherapy in treating non-melanoma skin cancers. Methods This retrospective study included 690 cases of non-melanoma skin cancers in 480 patients who received a diagnosis of a basal cell carcinoma or squamous cell carcinoma during a ten-year period. During treatment period, patients applied 30 applications of one of three combinations (imiquimod/tretinoin, 5-fluorouracil/tretinoin, or imiquimod/5-fluorouracil/tretinoin) and had cryotherapy every 2 weeks. Each patient had a clinical examination at least three years post-treatment or documented treatment failure. Clearance was defined by a lack of persistence or recurrence for 3 years following the completion of treatment. The likelihood of lesion clearance was evaluated using multivariable logistic regression analysis. Results A total of 186 cases (97; basal cell carcinoma and 89; squamous cell carcinoma) in 133 patients [37% women and 63% men; median (interquartile range) age, 77 (69, 83) years] met the inclusion criteria. Multivariable logistic regression analysis adjusting for clinical and lesion variables demonstrated that, relative to the imiquimod/5-fluorouracil/tretinoin treatment approach, imiquimod/ tretinoin (odds ratio, 0.05; 95% confidence interval, 0.00-0.99) and 5-fluorouracil/tretinoin (0.02; 0.00n0.45) were associated with lower likelihoods of lesion clearance. Likewise, morpheaform basal cell carcinoma had a lower probability of clearance (0.05; 0.00n0.72). Conclusions The combination of imiquimod/5-fluorouracil/tretinoin with cryotherapy had high clearance rates and was the most effective treatment regimen. J Drugs Dermatol. 2021;20(3):260-267. doi:10.36849/JDD.5427.

The recent coronavirus disease 2019 (COVID-19) pandemic has created a quandary for the physician in terms of evaluating and treating cutaneous skin cancers, particularly melanomas. At the onset of the pandemic, many planned medical and surgical visits for skin cancers were postponed. Physicians and patients have had to balance the risk of exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with that of worsening morbidity and mortality due to delays in skin cancer treatments. We present a male patient who had two melanoma-in-situs (MISs) that were treated during the COVID-19 pandemic with a combination of topical imiquimod 5% cream, 5-fluorouracil 2% solution, and tretinoin 0.1% cream. The successful treatments occurred without in-person visits and with the aid of telemedicine. Although surgery is the standard for the treatment of melanoma in situ, this case demonstrates an effective viable treatment modality for MIS during a pandemic situation.

We discuss a simple beam interference approximation method for deriving the angular selectivity of diffraction in weakly modulated volume holographic gratings. The results obtained using the multiple beam interference model agree qualitatively with the results obtained from a physical optics treatment of the coupled-wave theory for volume holographic gratings.

We investigated angular directivity of a diffracted beam in a shift-invariant holographic correlator. We showed that the experimental results agree well with our theoretical model, while the prediction of coupled wave model is incorrect.

A holographic Stokesmeter (HSM) utilizes the inherent polarization sensitivity of volume gratings to determine all the Stokes parameters of input beams. A unique feature of the HSM is that it can be designed for spectral multiplexing at a high speed. Here, we report the demonstration of such a spectrally scanning HSM for two different wavelengths. Integration of such an HSM with a polarimetric imaging system will produce a device of potentially significant practical usage: a multi-spectral Stokes parameter camera (MSPC).

Mitochondrial Complex II (succinate:ubiquinone oxidoreductase) is purified in a partially inactivated state, which can be activated by removal of tightly bound oxaloacetate (E.B. Kearney, et al., Biochem. Biophys. Res. Commun. 49 1115–1121). We crystallized Complex II in the presence of oxaloacetate or with the endogenous inhibitor bound. The structure showed a ligand essentially identical to the “malate-like intermediate” found in Shewanella Flavocytochrome c crystallized with fumarate (P. Taylor, et al., Nat. Struct. Biol. 6 1108–1112) Crystallization of Complex II in the presence of excess fumarate also gave the malate-like intermediate or a mixture of that and fumarate at the active site. In order to more conveniently monitor the occupation state of the dicarboxylate site, we are developing a library of UV/Vis spectral effects induced by binding different ligands to the site. Treatment with fumarate results in rapid development of the fumarate difference spectrum and then a very slow conversion into a species spectrally similar to the OAA-liganded complex. Complex II is known to be capable of oxidizing malate to the enol form of oxaloacetate (Y.O. Belikova, et al., Biochim. Biophys. Acta 936 1–9). The observations above suggest it may also be capable of interconverting fumarate and malate. It may be useful for understanding the mechanism and regulation of the enzyme to identify the malate-like intermediate and its pathway of formation from oxaloacetate or fumarate.

A holographic Stokesmeter has the potential to be useful in high-speed polarization imaging applications. Highly polarization-sensitive gratings are an important component for this device. Using two sets of multiplexed gratings, we measured the Stokes parameters for three different polarization states of an input beam. These measured values compared well to values measured using the quarter-wave plate/linear polarizer method. This establishes the feasibility of such a Stokesmeter in its original configuration. We demonstrate further the basic mechanism behind a compact architecture for this device, requiring only a single substrate and a single imaging system, and describe a spectrally scanned polarimetric imaging system.

A holographic Stokesmeter has the potential to be useful in high-speed polarization imaging applications. Highly polarization-sensitive gratings are an important component in a robust holographic Stokesmeter. We demonstrate a set of individual holographic gratings in a thick substrate displaying a high contrast in diffraction efficiency as a function of the polarization of the read beam. We confirm that the observed dependence is consistent with the coupled-wave analysis of such gratings. In addition, we performed a numerical analysis of the noise tolerance of such a Stokesmeter, and suggest a heterodyne architecture to further enhance signal-to-noise ratio.

Background: Apligraf is a bioengineered skin product composed of neonatal fibroblasts and keratinocytes. The FDA has approved Apligraf for the treatment of chronic venous ulcers and diabetic ulcers. Objective: We review the development of bioengineered skin, examine the cellular activities of various growth factors that may facilitate wound healing, and discuss the results of clinical trials with a particular construct, Apligraf, as proof of principle. Conclusion: Bioengineered skin acts as a “smart” delivery system for growth factors and other stimulatory substances. Not only does it present a novel treatment for chronic and diabetic ulcers, but it could also be considered for application to other types of acute wounds.

We present a mathematical model of coherent and incoherent beam combination in a thick hologram. We also derive the formulae relating the read and write angles to the read and write wavelengths for the combiner. Furthermore, we present a new technique for determining the M#, and establish that the M# required for a coherent combiner is substantially less than that needed for an incoherent one.

We report three new structures of mitochondrial respiratory Complex II (succinate ubiquinone oxidoreductase, E.C. 1.3.5.1) at up to 2.1 A resolution, with various inhibitors. The structures define the conformation of the bound inhibitors and suggest the residues involved in substrate binding and catalysis at the dicarboxylate site. In particular they support the role of Arg(297) as a general base catalyst accepting a proton in the dehydrogenation of succinate. The dicarboxylate ligand in oxaloacetate-containing crystals appears to be the same as that reported for Shewanella flavocytochrome c treated with fumarate. The plant and fungal toxin 3-nitropropionic acid, an irreversible inactivator of succinate dehydrogenase, forms a covalent adduct with the side chain of Arg(297). The modification eliminates a trypsin cleavage site in the flavoprotein, and tandem mass spectroscopic analysis of the new fragment shows the mass of Arg(297) to be increased by 83 Da and to have the potential of losing 44 Da, consistent with decarboxylation, during fragmentation.

We show polarization-dependent band-gap in a photonic-crystal composed of six rows of 4mm diameter Pyrex rods on a 9mm square lattice using FDTD, and describe how such a structure can be used as a Stokesmeter.

A holographic Stokesmeter utilizes polarization sensitivity of volume gratings to determine the Stokes parameters of an input beam. We demonstrate a spectrally multiplexed holographic stokesmeter for two different wavelengths of 532nm and 780nm simultaneously

We have developed a dye-doped poly(methyl methacrylate) holographic recording material that can be formed into different, arbitrary geometries. We show experimental results for multiplexed image storage as well as for an ultra-narrow filter.

A holographic Stokesmeter utilizes the inherent polarization sensitivity of volume gratings to determine the Stokes parameters of the input beam. We describe experimental results from an imaging holographic Stokesmeter capable of spectrally scanned polarimetry.

We demonstrate an efficient coherent holographic beam combiner (CHBC) that uses angle multiplexing of gratings in a thick polymeric substrate. Our experimental results compare well with the theoretical model based on the coupled-wave theory of multiwave mixing in a passive medium. A CHBC of this type may prove useful in producing a high-power laser by combining amplified beams produced by splitting a master oscillator. Furthermore, the ability to angle multiplex a large number of beams enables a CHBC to be used in multiple-beam interferometry applications as a high-precision surface sensor.

A procedure is presented for preparation of diffraction-quality crystals of a vertebrate mitochondrial respiratory complex II. The crystals have the potential to diffract to at least 2.0 A with optimization of post-crystal-growth treatment and cryoprotection. This should allow determination of the structure of this important and medically relevant membrane-protein complex at near-atomic resolution and provide great detail of the mode of binding of substrates and inhibitors at the two substrate-binding sites.

We propose and demonstrate a simple technique for determining the M/# parameter of a holographic recording material. In this method, divergent object and reference beams are used to produce a spatially varying index modulation. One can analyze the resultant diffraction pattern to find M/# by using only a single grating; existing techniques require many gratings.

For practical pattern recognition and tracking systems, it is often useful to have a high-speed random access memory (RAM), which complements a holographic correlator. Recently, we have demonstrated a super-parallel holographic optical correlator, which uniquely identifies N images from a database using only 2 number of detector elements. In this paper, we show how this correlator architecture, operated in reverse, may be used to realize a super-parallel holographic random access memory. We present preliminary results establishing the feasibility of the super-parallel holographic random access memory, and show that essentially the same set of hardware can be operated either as the super-parallel holographic optical correlator or as a super-parallel holographic random access memory, with a minor reorientation of some of the elements in real time. This hybrid device thus eliminates the need for a separate random access memory for a holographic correlator based target recognition and tracking system.

Thick holographic gratings can be designed to have a strong polarization dependence of the diffraction efficiency. Such gratings can be used in a holographic Stokesmeter that can determine all four Stokes parameters in parallel. We demonstrate the theory of this holographic Stokesmeter and show preliminary results.

The same elements of the architecture for a super-parallel holographic correlator can be operated as a holographic random access memory. This shared architecture allows the correlation or memory readout to occur in parallel at all spatial locations and at all angles.

We describe a superparallel holographic optical correlator that performs two-dimensional spatial and angular multiplexing simultaneously. The key step in this architecture is the use of a holographic multiplexer to split a query image into many copies before it applies them to the holographic database. A holographic demultiplexer, in conjunction with an aperture, is used to identify the location and the angle of the brightest correlation peak. This architecture uses only O(square root of N) detector elements to search through N unsorted images in a single query. We demonstrate the basic features of this architecture, using three spatial locations with eight angle-multiplexed images in each location.

The extraordinary advances in the field of growth factors and signal transduction have created new and promising therapeutic interventions. We intend to explain the difficult nomenclatures associated with growth factors and their mechanisms of action.

Venous ulcers are a common cause of pain and suffering in the elderly US population. Up to 1 million individuals suffer from this disease, and the true costs in terms of medical care and quality of life are only beginning to be appreciated. Bioengineered skin constructs are being used increasingly to treat venous ulcers with some success and can be used if traditional first-line treatment methods fail.

We demonstrate a translation-invariant VanderLugt correlator VLC for a set of images stored via holographic angle multiplexing of volume gratings in a polymeric substrate. The images read out from the volume gratings are optically correlated in a translation-invariant manner with a dc-suppressed holographic filter. The quality and efficiency of this correlator are observed to be nearly as good as that of another VLC with images directly from a spatial light modulator used as inputs. This ex- periment is the first step toward realizing a novel optical image recogni- tion system capable of identifying a query image through an exhaustive search in a large database of filter images stored in an ultrahigh capacity superparallel holographic random access memory SPHRAM. In this system, the identification of the query image is to be performed with a translation invariant, real-time VLC or a joint transform correlator JTC.

For practical pattern recognition and tracking systems, it is often useful to have a high-speed random access memory (RAM) that complements a holographic correlator. Recently, we have demonstrated a super-parallel holographic correlator, which uniquely identifies N im- ages from a database using only O(AN) number of detector elements. We show how this correlator architecture, operated in reverse, may be used to realize a super-parallel holographic random access memory. We present preliminary results, establishing the feasibility of the superparal- lel holographic random access memory, and show that essentially the same set of hardware can be operated either as the super-parallel holo- graphic optical correlator or as a super-parallel holographic random ac- cess memory, with minor reorientation of some of the elements in real time. This hybrid device thus eliminates the need for a separate random access memory for a holographic correlator-based target recognition and tracking system. © 2004 Society of Photo-Optical Instrumentation Engineers.

the perpetuation of the disease by secreting the inflammatory cytokines IL-5 and IL-13.4 These help recruiting granulocytes that produce tissue-destroying enzymes. Our observation in cicatricial pemphigoid supports the notion raised recently by Joly et al5 in bullous pemphigoid that autoimmune bullous diseases affecting the basement membrane can be successfully treated with topically applied agents circumventing the severe side effects often occurring upon systemic immunosuppression in the affected elderly population. The predominant action of tacrolimus on T lymphocytes might explain its superior potency compared with topical steroids.

We propose an ultrafast holographic Stokesmeter using a volume holographic substrate with two sets of two orthogonal gratings to identify all four Stokes parameters of the input beam. We derive the Mueller matrix of the proposed architecture and determine the constraints necessary for reconstructing the complete Stokes vector. The speed of this device is determined primarily by the channel spectral bandwidth (typically 100 GHz), corresponding to a few picoseconds. This device could be useful in high-speed polarization imaging.