Phenotypically complex living materials containing engineered cyanobacteria.

The field of engineered living materials lies at the intersection of materials science and synthetic biology with the aim of developing materials that can sense and respond to the environment. In this study, we use 3D printing to fabricate a cyanobacterial biocomposite material capable of producing multiple functional outputs in response to an external chemical stimulus and demonstrate the advantages of utilizing additive manufacturing techniques in controlling the shape of the fabricated photosynthetic material. As an initial proof-of-concept, a synthetic riboswitch is used to regulate the expression of a yellow fluorescent protein reporter in Synechococcus elongatus PCC 7942 within a hydrogel matrix. Subsequently, a strain of S. elongatus is engineered to produce an oxidative laccase enzyme; when printed within a hydrogel matrix the responsive biomaterial can decolorize a common textile dye pollutant, indigo carmine, potentially serving as a tool in environmental bioremediation. Finally, cells are engineered for inducible cell death to eliminate their presence once their activity is no longer required, which is an important function for biocontainment and minimizing environmental impact. By integrating genetically engineered stimuli-responsive cyanobacteria in volumetric 3D-printed designs, we demonstrate programmable photosynthetic biocomposite materials capable of producing functional outputs including, but not limited to, bioremediation.

An unexpected role for leucyl aminopeptidase in UV tolerance revealed by a genome-wide fitness assessment in a model cyanobacterium.

UV radiation (UVR) has significant physiological effects on organisms living at or near the Earth's surface, yet the full suite of genes required for fitness of a photosynthetic organism in a UVR-rich environment remains unknown. This study reports a genome-wide fitness assessment of the genes that affect UVR tolerance under environmentally relevant UVR dosages in the model cyanobacterium Synechococcus elongatus PCC 7942. Our results highlight the importance of specific genes that encode proteins involved in DNA repair, glutathione synthesis, and the assembly and maintenance of photosystem II, as well as genes that encode hypothetical proteins and others without an obvious connection to canonical methods of UVR tolerance. Disruption of a gene that encodes a leucyl aminopeptidase (LAP) conferred the greatest UVR-specific decrease in fitness. Enzymatic assays demonstrated a strong pH-dependent affinity of the LAP for the dipeptide cysteinyl-glycine, suggesting an involvement in glutathione catabolism as a function of night-time cytosolic pH level. A low differential expression of the LAP gene under acute UVR exposure suggests that its relative importance would be overlooked in transcript-dependent screens. Subsequent experiments revealed a similar UVR-sensitivity phenotype in LAP knockouts of other organisms, indicating conservation of the functional role of LAPs in UVR tolerance.

Battlefield Triage and Resource Allocation during a Pandemic: Learning from the Past and Adapting for the Future.

The principle of medical triage, where patients are sorted into categories to guide the order in which they receive treatment, dates back to Baron Dominique Jean Larrey, the surgeon general of Napolean's armies. The concept evolved with military conflicts throughout the 19th century, was subsequently adapted to situations off the battlefield, and is now widely practiced where resources are limited.2 Military medical providers are taught triage principles early in their careers and its use is routinely integrated into military training scenarios and operational planning.

Treatment of Post-Inflammatory Hyperpigmentation in Patients With Darker Skin Types Using a Low Energy 1,927 nm Non-Ablative Fractional Laser: A Retrospective Photographic Review Analysis.

BACKGROUND AND OBJECTIVES: Post inflammatory hyperpigmentation (PIH) can be difficult to treat especially in patients with darker skin types as darker skin carries increased epidermal melanin content. Various treatments available to improve the appearance of PIH may incite further pigmentation thus making treatment extremely difficult and frustrating. The purpose of this study was to perform a retrospective chart and photographic review to evaluate the efficacy and safety profile of a low energy low density non-ablative fractional1927 nm wavelength laser treatment for PIH in patients with Fitzpatrick skin types IV-VI. STUDY DESIGN: A retrospective evaluation of 61 patients with PIH treated with a 1927 nm laser was conducted at a single center. Inclusion criteria required at least 2 treatment sessions so that before and after treatment photographs would be available for comparison and study purposes. Two blinded physician-evaluators using a visual analog scale for percentage of pigmentary clearance in standard photographs assessed treatment efficacy. RESULTS: The mean percent improvement after treatment, evaluated by two dermatologists was 43.24%. The correlation between raters was statistically significant (Pearson's correlation coefficienct of r = 0.59, p < 0.0001). No side effects were observed in the patients treated with the 1927 nm laser. CONCLUSION: The low energy low density non-ablative fractional 1927 nm wavelength laser is a safe and effective modality for improving post inflammatory hyperpigmentation in patients with darker skin types. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Successful and safe use of Q-switched lasers in the treatment of nevus of Ota in children with phototypes IV-VI.

OBJECTIVE: Nevus of Ota represents congenital dermal melanocytosis in a trigeminal distribution, most commonly occurring in Asian individuals and other individuals with skin of color. Evidence suggests early treatment is beneficial. Multiple reports have shown efficacy and safety of Q-switched laser treatment in adults. There is little data on children and in non-Asian skin types. This series was done to demonstrate safe and effective use of Q-switched laser therapy in children of multiple skin types. STUDY DESIGN: Retrospective case series. METHODS: This was a chart review of patients under 18 years old who presented to our practice from 2002 to 2015 with a clinical diagnosis of nevus of Ota who were treated with Q-switched lasers (694 and 1,064 nm). Patients were treated without the use of general anesthesia or sedation, and corneal shields were used in appropriate cases. Percentage of improvement as well as side effects were rated by five physicians independently. Improvement, when present, was rated in quartiles (1-25%, 26-50%, 51-75%, and 76-100% improvement). RESULTS: Twenty-four children were included. The average age at the start of treatment was 3.9 years old (range of 3 months to 12.4 years), and patients had Fitzpatrick skin types IV through VI. The mean number of treatments was 9.3. Assessment revealed excellent response (76-100% improvement) in 70% of patients and good to excellent response (51-100% improvement) in 86%. Two patients (8%) had post-inflammatory hyperpigmentation, one of whom also had focal hypopigmentation. CONCLUSION: Treatment of nevus of Ota with Q-switched lasers in children with skin of color, without general anesthesia or sedation, is safe and effective. Early intervention should be encouraged for better efficacy and to prevent psychosocial distress in later childhood and adulthood. Lasers Surg. Med. 50:56-60, 2018. © 2017 Wiley Periodicals, Inc.

Controls on the distribution of fluorescent dissolved organic matter during an under-ice algal bloom in the western Arctic Ocean.

In this study we used fluorescence excitation and emission matrix spectroscopy, hydrographic data, and a self-organizing map (SOM) analysis to assess the spatial distribution of labile and refractory fluorescent dissolved organic matter (FDOM) for the Chukchi and Beaufort Seas at the time of a massive under-ice phytoplankton bloom during early summer 2011. Biogeochemical properties were assessed through decomposition of water property classes and sample classification that employed a SOM neural network-based analysis which classified 10 clusters from 269 samples and 17 variables. The terrestrial, humic-like component FDOM (ArC1, 4.98 ± 1.54 Quinine Sulfate Units (QSU)) and protein-like component FDOM (ArC3, 1.63 ± 0.88 QSU) were found to have elevated fluorescence in the Lower Polar Mixed Layer (LPML) (salinity ~29.56 ± 0.76). In the LPML water mass, the observed contribution of meteoric water fraction was 17%, relative to a 12% contribution from the sea ice melt fraction. The labile ArC3-protein-like component (2.01 ± 1.92 QSU) was also observed to be elevated in the Pacific Winter Waters mass, where the under-ice algal bloom was observed (~40-50 m). We interpreted these relationships to indicate that the accumulation and variable distribution of the protein-like component on the shelf could be influenced directly by sea ice melt, transport, and mixing processes and indirectly by the in situ algal bloom and microbial activity. ArC5, corresponding to what is commonly considered marine humic FDOM, indicated a bimodal distribution with high values in both the freshest and saltiest waters. The association of ArC5 with deep, dense salty water is consistent with this component as refractory humic-like FDOM, whereas our evidence of a terrestrial origin challenges this classic paradigm for this component.

The Photodynamic Therapy Experience of a High Volume Laser and Dermatologic Surgery Center.

BACKGROUND: Photodynamic therapy (PDT) is an FDA approved treatment for actinic keratoses (AK's) although multiple off-label indi- cations are reported. Despite frequent use for AK's, no clear consensus exists regarding protocols for overall treatment parameters. METHODS: Retrospective chart review of 1,491 subjects who underwent PDT between 2007 and 2011 at a high volume laser surgery center. Demographic information, clinical history, treatment data, and subsequent diagnosis of skin cancers were recorded. An ex- ploratory subgroup analysis was performed for patients treated for AK and/or squamous cell carcinoma (SCC) that developed SCC or remained SCC-free one year after treatment. RESULTS: The most common indications for PDT were actinic keratoses (n=1404, 94.9%) then NMSC (n=45, 3.0%) The most common treatment site was the head and neck (n=1274, 86.1%). Blue light activation (405-420nm) was used more frequently than red light and visible light. (73.8% vs. 22.8% vs. 6.8%). The most commonly used photosensitizer was aminolevulinic acid (ALA) (98.6%, n=1456). Topical application (97.7% n=1437) of photosensitizer was used more frequently than intralesional administration (2.0%, n=29). 580 patients met subgroup analysis criteria. 66 developed SCC at treatment site (11%). Factors associated with developing SCC were older age, SCC history, Fitzpatrick skin-type 1, and sixty-minute or less incubation times (P less than 0.05 for all factors). The SCC subgroup had a unique distribution of treatment sites (P less than.001). No statistically significant differences were observed for gender or wavelength. CONCLUSION: There are differences in protocols based on indication and location of lesion. Blue light is preferable for superFIcial lesions and red light for deeper lesions. Intralesional delivery is used more commonly for NMSC. Extremities require longer incubation times. PDT may be more effective with younger patients and longer than sixty-minute incubation times. PDT chemoprevention is independent of light source used. J Drugs Dermatol. 2016;15(11):1420-1426..

An evaluation of the patient population for aesthetic treatments targeting abdominal subcutaneous adipose tissue.

A large and growing population of patients currently seeks minimally invasive therapeutic options for the aesthetic treatment of localized, central abdominal subcutaneous adipose tissue (SAT). We sought to evaluate the ideal population for aesthetic treatment of central abdominal SAT, highlight the existing disparities between SAT in obese (body mass index [BMI] ≥ 30; BMI) and nonobese (BMI < 30) patients, and review the available FDA-cleared, minimally invasive treatment options for central abdominal adiposity. The cosmetic issue of localized, central (periumbilical) abdominal adiposity in nonobese individuals is quite distinct from abdominal bulging secondary to obesity. Given the recognized clinical and physiologic differences between obese and nonobese counterparts, the exclusion of obese patients from clinical study by currently available FDA-cleared devices targeting abdominal fat, and the status of obesity as a chronic, systemic disease requiring medical, surgical, and/or lifestyle-altering therapies, minimally invasive therapeutic options for aesthetic reductions in central abdominal SAT must be limited to the nonobese population.

Retrospective study of the treatment of infantile hemangiomas using a combination of propranolol and pulsed dye laser.

BACKGROUND: Infantile hemangioma (IH) clearance may be slow or incomplete in response to pulsed dye laser (PDL) or propranolol alone. OBJECTIVES: To evaluate whether IH treated with PDL and propranolol displayed more rapid and complete clearance than IH treated with propranolol alone. MATERIALS AND METHODS: Retrospective review of facial-segmental IH treated with propranolol and PDL and controls treated with propranolol was conducted. Blinded physicians used patient photographs to select clearance level and the earliest date of near-complete clearance. Days of propranolol, PDL sessions, and propranolol dose, each until date of near-complete clearance; total days of propranolol; and total propranolol dose were recorded. RESULTS: Infantile hemangiomas treated concurrently with propranolol and PDL achieved complete clearance (6/12) more often than IH treated with propranolol followed by PDL (2/5) or IH treated with propranolol alone (1/8; difference in clearance scores p = .01) and achieved near-complete clearance after fewer days of propranolol (mean 92 days for concurrent propranolol and PDL vs 288 days for propranolol; p < .001). Cumulative propranolol dose until near-complete clearance was lowest in the concurrent propranolol and PDL group (149.16 vs. 401.25 mg/kg for propranolol; p < .001). CONCLUSION: Facial-segmental IH treated with propranolol and PDL displayed morerapid and complete clearance and required a lower cumulative propranolol dose to achieve near-complete clearance.

Treatment of port-wine stains with a short pulse width 532-nm Nd:YAG laser.

BACKGROUND AND OBJECTIVE: Pulsed dye laser treatment often results in port-wine stain (PWS) improvement; however, results vary. A frequency-doubled neodymium-doped yttrium aluminum garnet (Nd:YAG) laser that allows for shorter pulse widths along with large spot sizes and high fluences has been developed for the treatment of cutaneous vascular lesions. STUDY DESIGN: A prospective, controlled study was performed in 5 adults with PWS using a frequency-doubled Nd:YAG laser (Excel V; Cutera Inc, Brisbane, CA) in 4 quadrants, using spot sizes of 6 to 10 mm, fluences of 4.8 to 9 J/cm2, and pulse durations of 3 to 6 ms. An adjacent control area was not treated. Each was assessed immediately posttreatment for purpura and edema and at 1 month for PWS color, size, texture, and thickness. Skin biopsies obtained immediately after and at 1 month posttreatment were evaluated. RESULTS: All treatment quadrants displayed purpura. At 1-month follow-up, all treatment quadrants showed at least 1 grade of color improvement, from a minimum of 1% to 25% to a maximum of 51% to 75% improvement (12/20 quadrants with 1%-25% improvement, 3/20 with 26%-50%, 5/20 with 51%-75%, and 0/20 with 76%-100%). Histologic evaluation of treatment quadrants revealed vascular changes ranging 0.35 to 4 mm in depth. Immediately posttreatment, thrombi and extravasated red blood cells were observed in treatment quadrants. Histology at 1 month revealed decreased number and diameter of vessels in treatment quadrants (superficial vessels decreased by mean 1.1 vessels per section [13%], and diameter by 3.0 µm [47%], midlevel vessels decreased in number by 2.3 [20%], diameter by 2.42 µm [25%], and deep vessels decreased in number by 1.5 [83%], and diameter by 7.44 µm [88%]). CONCLUSIONS: A single treatment with a short pulse width, frequency-doubled Nd:YAG laser resulted in safe and effective improvement of PWS, with up to 75% improvement in color observed at 1 month. Histologic evaluation demonstrated vascular injury at depths of 0.35 to 4 mm with a reduction in vessel number and size at multiple dermal levels.

1927-nm fractional resurfacing of facial actinic keratoses: a promising new therapeutic option.

BACKGROUND: Actinic keratoses (AK) are precancerous epidermal proliferations commonly present on chronically sun-damaged skin. These lesions are among the most often treated dermatologic conditions. OBJECTIVE: We sought to investigate the 6-month safety, tolerance, and efficacy of nonablative 1927-nm fractional resurfacing of facial AK. METHODS: This was a prospective clinical trial of 24 individuals with facial photodamage and AK receiving up to 4 treatments with the fractionated 1927-nm nonablative thulium laser. RESULTS: At 6 months, an 86.6% reduction in absolute number of lesions was noted by independent physician assessment. In addition, at this same time point, patients reported marked or noticeable improvement in overall photodamage. LIMITATIONS: This prospective study does not provide safety, tolerance, and efficacy data beyond 6 months of follow-up, nor does it identify the precise mechanism of action involved in AK clearance after 1927-nm resurfacing. CONCLUSION: The clinical and histologic findings, as well as the reported patient satisfaction and safety, suggest that the treatment of AK and photodamage with a fractionated 1927-nm nonablative thulium laser is a promising new therapeutic option.

Topical perfluorodecalin resolves immediate whitening reactions and allows rapid effective multiple pass treatment of tattoos.

BACKGROUND AND OBJECTIVE: Laser tattoo removal using multiple passes per session, with each pass delivered after spontaneous resolution of whitening, improves tattoo fading in a 60-minute treatment time. Our objective was to evaluate the safety and efficacy of topical perfluorodecalin (PFD) in facilitating rapid effective multiple-pass tattoo removal. STUDY DESIGN: In a randomized, controlled study using Q-switched ruby or Nd:YAG laser, 22 previously treated tattoos were treated with 3 passes using PFD to resolve whitening after each pass ("R0 method"). In previously untreated symmetric tattoos, seven were treated over half of the tattoo with the R20 method, and the opposite half with 4 passes using PFD (R0 method); two were treated over half with a single pass and the opposite half with 4 passes using PFD (R0 method); and six treated over half with a single pass followed by PFD and the opposite half with a single pass alone. Blinded dermatologists rated tattoo fading at 1-3 months. Optical coherence tomography (OCT) imaging of whitening was performed in two tattoos. RESULTS: Topical PFD clinically resolved immediate whitening reactions within a mean 5 seconds (range 3-10 seconds). Tattoos treated with the R0 method demonstrated excellent fading in an average total treatment time of 5 minutes. Tattoo areas treated with the R0 method demonstrated equal fading compared to the R20 method, and improved fading compared to a single pass method. OCT imaging of whitening demonstrated epidermal and dermal hyper-reflective "bubbles" that dissipated until absent at 9-10 minutes after PFD application, and at 20 minutes without intervention. CONCLUSIONS: Multiple-pass tattoo removal using PFD to deliver rapid sequential passes (R0 method) appears equally effective as the R20 method, in a total treatment time averaging 5 minutes, and more effective than single pass treatment. OCT-visualized whitening-associated "bubbles," upon treatment with PFD, resolve twice as rapidly as spontaneous resolution.

Ablative fractional resurfacing for involuted hemangioma residuum.

BACKGROUND Given the natural tendency for 15% to 40% of infantile hemangiomas to spontaneously involute over time, much debate surrounds the issue of treatment. Until recently, effective therapies to improve the appearance of residual textural skin changes in these patients were lacking. We suggest the use of ablative fractional resurfacing for the treatment of textural skin changes resulting from involuted hemangiomas. OBSERVATIONS All patients treated with an ablative fractional carbon dioxide laser experienced considerable flattening of the fibrofatty residual tissue, with at least 50% to 75% improvement in color, texture, and overall appearance. CONCLUSION While additional future studies are needed, we believe that ablative fractional resurfacing should be considered for the treatment of textural skin changes associated with involuted infantile hemangiomas.

Successful and rapid treatment of blue and green tattoo pigment with a novel picosecond laser.

BACKGROUND: While the understanding and technology of laser tattoo removal has advanced much over the last 5 decades, treatments and results remain far from perfect. With currently available devices, treatment courses are often painful and prolonged with mixed results. We describe the successful and rapid treatment of 12 tattoos containing blue and/or green pigment with a novel, picosecond, 755-nm alexandrite laser. OBSERVATIONS: All previously untreated multicolored tattoos as well as tattoos recalcitrant to treatment demonstrated at least 75% clearance of blue and green pigment after 1 or 2 treatments with a novel, picosecond, 755-nm alexandrite laser. More than two-thirds of these tattoos approached closer to 100% clearance. CONCLUSIONS: While additional future studies are needed, we believe that this new technology is more effective in targeting blue and green pigment, resulting in expedited clearance with less collateral injury to surrounding tissue.

Quantitation of the results of abdominal liposuction.

BACKGROUND: There are few objective techniques to accurately measure the outcome of liposuction. Consequently, there is also a paucity of data quantifying the results of this procedure. OBJECTIVES: The authors compare changes in abdominal volume and circumference with several objective measurement techniques in a relatively homogeneous group of individuals undergoing liposuction in a single, defined abdominal region. METHODS: This clinical study enrolled 23 patients with a body mass index (BMI) <25 kg/m(2) who had a localized anterior abdominal contour defect. Patients underwent standard suction-assisted tumescent liposuction. Changes in abdominal volume and circumference in the operative area (60 mm above to 80 mm below the umbilicus) preoperatively and 10 weeks postoperatively were assessed using a 3-dimensional (3D) digital photographic system and a standardized constant-tension manual tape measure procedure. RESULTS: The majority of the patients in this study were Caucasian women with a mean age of 42 years, a mean weight of 65.8 kg, and a mean BMI of 23.8 kg/m(2). In the study population, mean abdominal volume and umbilical circumference were reduced by 231.0 mL (~30% of subcutaneous fat) and 1.7 cm, respectively, at 10 weeks postoperatively as determined by 3D digital imaging. Fat volume in the surgical aspirate (mean = -183.3 mL) was a poor predictor of individual outcome, as assessed 10 weeks postoperatively by both the 3D digital imaging and multilevel constant-tension tape measure assessment tools. CONCLUSIONS: Both 3D digital photographic imaging and a standardized manual tape measurement procedure proved to be reliable tools for objectively assessing changes in abdominal circumference and volume produced by standard liposuction of a single, defined abdominal region.

Calcium hydroxylapatite nodule resolution after fractional carbon dioxide laser therapy.

BACKGROUND: Injection of calcium hydroxylapatite filler may result in nodule formation owing to superficial placement of the filler. Calcium hydroxylapatite nodules are difficult to reverse. Previously reported therapeutic options are limited and include intralesional triamcinolone, massage, needling, and excision, each with inconsistent results or potential for scarring. OBSERVATION: We have observed complete resolution of calcium hydroxylapatite nodules after a single treatment with fractional carbon dioxide laser. CONCLUSIONS: A single session of fractional carbon dioxide laser treatment may resolve selected cases of calcium hydroxylapatite nodules. The mechanism of action may involve conversion of the product into tricalcium phosphates which dissolve readily. This novel therapeutic technique may enhance treatment options for a difficult clinical problem.

Investigation into optimal treatment intervals of facial port-wine stains using the pulsed dye laser.

BACKGROUND: Port-wine stains (PWS) affect 0.3% to 0.5% of newborns and pulsed dye laser (PDL) remains the treatment of choice. Optimal treatment intervals have not been established. OBJECTIVE: We sought to validate the optimal treatment intervals for the management of facial PWS with PDL. METHODS: In all, 24 infants with facial PWS who received at least 5 treatments with the PDL at 2-, 3-, and 4-week intervals at a private laser and skin surgery center from 2009 to 2010 were identified by a retrospective chart review. Safety and efficacy were compared by blinded investigators. RESULTS: Side effects were equivalent in all interval groups and included only expected short-term erythema, edema, purpura, and mild postinflammatory hyperpigmentation. No patient developed hypopigmentation, scarring, or infection. All interval groups showed 50% to 100% clearance of their PWS after 5 treatments. Complete or near-complete clearance was seen in 6 of 8 (75%) and 7 of 8 (87.5%) patients in the 2- and 3-week interval groups, respectively, as compared with 3 of 8 (37.5%) patients in the 4-week interval group. LIMITATIONS: This was a retrospective chart review from a single institution. Long-term side effects and recurrence rates were not assessed. CONCLUSION: We conclude that PDL treatments at 2-, 3-, and 4-week intervals are effective for the management of facial PWS in infants with minimal short-term side effects. Shorter treatment intervals may allow for relatively more rapid and more effective treatment.

Reduction of thickened flap using fractional carbon dioxide laser.

BACKGROUND AND OBJECTIVE: The paramedian forehead flap is an excellent choice when repairing a large nasal defect. However, even when carefully thinned, the flap may develop a bulky appearance, an ill-fitting contour, or trap door deformity. When on the face, these suboptimal results can be quite distressing. Surgical and non-surgical options for improvement exist. Surgical options include additional debulking and reorientation of the flap. Non-surgical options include intralesional corticosteroids or 5-flourouracil, dermabrasion, and ablative and non-ablative laser resurfacing. Each option has limited benefit as well potential side effects. STUDY DESIGN/MATERIALS AND METHODS: Case report. RESULTS: In this report, we present dramatic improvement of a thickened paramedian forehead flap using the Fraxel Re:pair, a fractional carbon dioxide (CO(2) ) laser (Solta Medical, Inc. Hayward, CA). CONCLUSION: To our knowledge, this is the first case in the literature demonstrating successful reduction of a bulky flap using a fractional ablative laser.