Engineering functional skin constructs: A quantitative comparison of three-dimensional bioprinting with traditional methods.

Tissue engineering has been successful in reproducing human skin equivalents while incorporating new approaches such as three-dimensional (3D) bioprinting. The latter method offers a plethora of advantages including increased production scale, ability to incorporate multiple cell types and printing on demand. However, the quality of printed skin equivalents compared to those developed manually has never been assessed. To leverage the benefits of this method, it is imperative that 3D-printed skin should be structurally and functionally similar to real human skin. Here, we developed four bilayered human skin epidermal-dermal equivalents: non-printed dermis and epidermis (NN), printed dermis and epidermis (PP), printed epidermis and non-printed dermis (PN), and non-printed epidermis and printed dermis (NP). The effects of printing induced shear stress [0.025 kPa (epidermis); 0.049 kPa (dermis)] were characterized both at the cellular and at the tissue level. At cellular level, no statistically significant differences in keratinocyte colony-forming efficiency (CFE) (p = 0.1641) were observed. In the case of fibroblasts, no significant differences in the cell alignment index (p < 0.1717) and their ability to contract collagen gel (p = 0.851) were detected. At the tissue levels, all the four skin equivalents were characterized using histological and immunohistochemical analysis with no significant differences found in either epidermal basal cell count, thickness of viable epidermis, and relative intensity of filaggrin and claudin-1. Our results demonstrated that 3D printing can achieve the same high-quality skin constructs as have been developed traditionally, thus opening new avenues for numerous high-throughput industrial and clinical applications.

Voruciclib, a Potent CDK4/6 Inhibitor, Antagonizes ABCB1 and ABCG2-Mediated Multi-Drug Resistance in Cancer Cells.

BACKGROUND/AIMS: The overexpression of ATP-Binding Cassette (ABC) transporters has known to be one of the major obstacles impeding the success of chemotherapy in drug resistant cancers. In this study, we evaluated voruciclib, a CDK 4/6 inhibitor, for its chemo-sensitizing activity in ABCB1- and ABCG2- overexpressing cells. METHODS: Cytotoxicity and reversal effect of voruciclib was determined by MTT assay. The intracellular accumulation and efflux of ABCB1 and ABCG2 substrates were measured by scintillation counter. The effects on expression and intracellular localization of ABCB1 and ABCG2 proteins were determined by Western blotting and immunofluorescence, respectively. Vanadate-sensitive ATPase assay was done to determine the effect of voruciclib on the ATPase activity of ABCB1 and ABCG2. Flow cytometric analysis was done to determine the effect of voruciclib on apoptosis of ABCB1 and ABCG2-overexpressing cells and docking analysis was done to determine the interaction of voruciclib with ABCB1 and ACBG2 protein. RESULTS: Voruciclib significantly potentiated the effect of paclitaxel and doxorubicin in ABCB1-overexpressing cells, as well as mitoxantrone and SN-38 in ABCG2-overexpressing cells. Voruciclib moderately sensitized ABCC10- overexpressing cells to paclitaxel, whereas it did not alter the cytotoxicity of substrates of ABCC1. Furthermore, voruciclib increased the intracellular accumulation and decreased the efflux of substrate anti-cancer drugs from ABCB1- or ABCG2-overexpressing cells. However, voruciclib did not alter the expression or the sub-cellular localization of ABCB1 or ABCG2. Voruciclib stimulated the ATPase activity of both ABCB1 and ABCG2 in a concentration-dependent manner. Lastly, voruciclib exhibited a drug-induced apoptotic effect in ABCB1- or ABCG2- overexpressing cells. CONCLUSION: Voruciclib is currently a phase I clinical trial drug. Our findings strongly support its potential use in combination with conventional anti-cancer drugs for cancer chemotherapy.

Short- and long-term readmission rates after infrainguinal bypass in a safety net hospital are higher than expected.

OBJECTIVE: Readmission rates are expected to have an increasing effect on both the hospital bottom line and physician reimbursements. Safety net hospitals may be most vulnerable. We examined readmissions at 30 days, 90 days, and 1 year in a large safety net hospital to determine the magnitude and effect of short- and long-term readmission rates after lower extremity infrainguinal bypass in this setting. METHODS: All nonemergent extremity infrainguinal bypass performed at a large safety net hospital between 2008 and 2016 were identified. Patient demographic, social, clinical, and procedural details were extracted from the electronic medical record. An analysis of patients readmitted at 30 days, 90 days, and 1 year was completed to determine the details of the readmission. RESULTS: A total of 350 patients undergoing extremity infrainguinal bypass were identified. The most frequent indication was tissue loss (57%), followed by claudication (25.6%), and rest pain (17.4%). Patient insurance carriers included Medicare (61.7%), Medicaid (25.4%), and private (13%). The distal target was the popliteal and tibial artery in 52.6% and 47.4% cases, respectively. The majority of bypasses used autologous vein (73.1%). In-hospital complications included pulmonary complications (4.3%), urinary tract infection (3.1%), acute renal failure (2%), graft occlusion (2%), myocardial infarction (1.7%), bleeding (1.4%), surgical wound complications (1.1%), and stroke (0.9%). The 30-day readmission rate was 30% with the most common reasons for readmission being surgical wound complications, nonsurgical foot/leg wounds, nonextremity infectious causes, cardiac ischemia, and congestive heart failure. The 90-day readmission rate was 49.4% and the most common reasons for readmission from 31 to 90 days were nonsurgical foot/leg wounds, graft complications, surgical wound complications, cardiac ischemia, and contralateral leg morbidity. The readmission rate within 1 year was 72.2%. Readmission causes from 91 days to 1 year included graft complications, contralateral leg morbidity, nonextremity infectious, nonsurgical foot/leg wounds, cardiac ischemia, and congestive heart failure. A tibial bypass target was associated with 30-day (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.06-2.69; P = .029) and 90-day (OR, 1.77; 95% CI, 1.14-2.74, P = .011) readmission. Nonprivate insurance (OR, 2.31; 95% CI, 1.17-4.57, P = .016), and critical limb ischemia (OR, 1.77; 95% CI, 1.14-2.74; P = .035) were associated with 1-year readmission. CONCLUSIONS: Short- and long-term readmission rates in a safety net setting are high. The 30-day rates in this study are higher than historically reported. This data sets baseline rates for 90-day and 1-year readmission for future analyses. Although the majority of short-term readmissions are related to the index procedure, long-term readmission rates are more frequently related to systemic comorbidities. Targeted patient interventions aimed at preventing the most common reasons for readmission may improve readmission rates, particularly among patients with nonprivate insurance. However, other risk factors, such as tibial target, may not be modifiable and a higher readmission rate may need to be accepted in this population.

The effect of ambulatory status on outcomes of percutaneous vascular interventions and lower extremity bypass for critical limb ischemia in the Vascular Quality Initiative.

OBJECTIVE: Ambulatory status has been shown to be an important predictor of postoperative morbidity and mortality for a variety of surgical procedures. We sought to assess contemporary practice patterns in treating critical limb ischemia (CLI) and outcomes based on ambulatory status. METHODS: The Vascular Quality Initiative (2010-2015) was queried for patients undergoing percutaneous vascular interventions (PVIs) or lower extremity bypass (LEB) for CLI. Ambulatory status was classified as ambulatory, ambulatory with assistance, and nonambulatory (composite of wheelchair bound and bedridden). Perioperative and postoperative outcomes were recorded. Multivariable analyses were performed to identify the effect of ambulatory status. RESULTS: There were 11,522 ambulatory (PVI, 63%; LEB, 37%), 4443 ambulatory with assistance (PVI, 67%; LEB, 33%), and 1732 nonambulatory (PVI, 77%; LEB, 23%) patients with CLI treated (P < .01 across ambulatory status groups). Perioperative mortality for PVI and LEB for ambulatory, ambulatory with assistance, and nonambulatory status was 1.5% and 1.7%, 3.0% and 3.1%, and 4.7% and 4.9%, respectively (P < .01 across ambulatory status groups). Worsening ambulatory status was associated with higher perioperative complications with PVI and LEB. Multivariable analysis showed that worsening ambulatory status predicted higher postprocedural mortality, amputation or death, and major adverse limb events or death. CONCLUSIONS: In the Vascular Quality Initiative, as ambulatory status declines, perioperative morbidity and mortality increase. Impaired ambulatory patients are more likely to receive PVI than LEB for the treatment of CLI, although even among nonambulatory patients, there are still a significant number who receive LEB.

Cytotoxic and acute toxicity studies of isoniazid derivatives.

Cancer is ultimately the result of cells that hysterically grow and do not die. Cells can experience uncontrolled growth if there are mutations to DNA, and therefore, alterations to the genes involved in cell division. Cancer occurs when a cell's gene mutations make the cell unable to correct DNA damage and is unable to destroy itself. There are over 100 different types of cancer each classified by the type of initially affected cell. Isoniazid, a well-known antitubercular agent has been reported to exhibit some cytotoxic activity. This finding prompt us to carry out this study where isoniazid and its sixteen derivatives were studied for any possible cytotoxic activity against Human astrocytoma SNB-19 cells, human Dukes' type C colorectal adenocarcinoma HCT-15 cells, human Dukes' type D colorectal adenocarcinoma COLO-205 cells, and human prostate adenocarcinoma (grade IV) PC-3 cells. Among the test compounds, SN-07 (a phenacyl derivative with para phenyl substitution) demonstrated slight cytotoxic effects on two types of human colorectal adenocarcinoma cells HCT-15 and COLO-205. Moreover, the acute toxicity of the compounds was also estimated in which some compounds were evaluated with more LD50 values than isoniazid.

Association between Psoriasis and MTHFR polymorphisms: a systematic review and meta-analysis.

Methylenetetrahydrofolate reductase (MTHFR) is key to the metabolism of folic acid, with loss of function mutations resulting in elevated homocysteine levels, a known risk factor for cardiovascular disease. Psoriasis patients may demonstrate hyperhomocysteinemia. To assess for the association between psoriasis and MTHFR C677T and A1298C polymorphisms. A systematic literature search was conducted in MEDLINE, Embase, Cochrane CENTRAL, and Web of Science. Case reports, case-control, cohort, and cross-sectional studies with full-text availability in English were considered. Meta-analysis was conducted with pooled ORs calculated via the random effects model (I2 > 50%). Of 917 records identified, 10 studies were selected for review of 1965 psoriasis patients and 2030 controls. Meta-analysis demonstrated that for MTHFR C677T, there were positive associations between psoriasis and the allele contrast model (C vs T, pooled OR = 1.69, 95% CI = 1.10-2.59), the additive model (CC vs TT, pooled OR = 2.44, 95% CI = 1.06-5.60), the dominant model (CC vs CT + TT, pooled OR = 1.77, 95% CI = 1.06-2.98), and the recessive model (CC + CT vs TT, pooled OR = 2.08, 95% CI = 1.05-4.13). For MTHFR A1298C, there were positive associations between psoriasis and the allele contrast model (A vs C, pooled OR = 3.57, 95% CI = 1.19-10.68), the dominant model (AA vs AC + CC, pooled OR = 4.44, 95% CI = 1.12-17.66), and the overdominant model (AC vs AA + CC, pooled OR = 0.26, 95% CI = 0.07-0.91). There may be a link between the C677T and A1298C polymorphisms with psoriasis diagnosis.

Skin substitutes for the management of mohs micrographic surgery wounds: a systematic review.

The data on skin substitute usage for managing Mohs micrographic surgery (MMS) wounds remain limited. This systematic review aimed to provide an overview of skin substitutes employed for MMS reconstruction, summarize clinical characteristics of patients undergoing skin substitute-based repair after MMS, and identify advantages and limitations of skin substitute implementation. A systematic review of Ovid MEDLINE, EMBASE, Cochrane Library, and Web of Science databases, from inception to April 7, 2021, identified all cases of MMS defects repaired using skin substitutes. A total of 687 patients were included. The mean patient age was 70 years (range: 6-98 years). Commonly used skin substitutes were porcine collagen (n = 397), bovine collagen (n = 78), Integra (n = 53), Hyalofill (n = 43), amnion/chorion-derived grafts (n = 40), and allogeneic epidermal-dermal composite grafts (n = 35). Common factors influencing skin substitute selection were cost, healing efficacy, cosmetic outcome, patient comfort, and ease of use. Some articles did not specify patient and wound characteristics. Skin substitute usage in MMS reconstruction is not well-guided. Blinded randomized control trials comparing the efficacy of skin substitutes and traditional repair methods are imperative for establishing evidence-based guidelines on skin substitute usage following MMS.

Autologous Skin Grafts, versus Tissue-engineered Skin Constructs: A Systematic Review and Meta-analysis.

For over 100 years, autologous skin grafts have remained the gold standard for the reconstruction of wounds but are limited in availability. Acellular tissue-engineered skin constructs (acellular TCs) and cellular tissue-engineered skin constructs (cellular TCs) may address these limitations. This systematic review and meta-analysis compare outcomes between them. Methods: A systematic review was conducted using PRISMA guidelines, querying MEDLINE, Embase, Web of Science, and Cochrane to assess graft incorporation, failure, and wound healing. Case reports/series, reviews, in vitro/in vivo work, non-English articles or articles without full text were excluded. Results: Sixty-six articles encompassing 4076 patients were included. No significant differences were found between graft failure rates (P = 0.07) and mean difference of percent reepithelialization (p = 0.92) when split-thickness skin grafts were applied alone versus co-grafted with acellular TCs. Similar mean Vancouver Scar Scale was found for these two groups (p = 0.09). Twenty-one studies used at least one cellular TC. Weighted averages from pooled results did not reveal statistically significant differences in mean reepithelialization or failure rates for epidermal cellular TCs compared with split-thickness skin grafts (p = 0.55). Conclusions: This systematic review is the first to illustrate comparable functional and wound healing outcomes between split-thickness skin grafts alone and those co-grafted with acellular TCs. The use of cellular TCs seems promising from preliminary findings. However, these results are limited in clinical applicability due to the heterogeneity of study data, and further level 1 evidence is required to determine the safety and efficacy of these constructs.

Trends in Gender Representation and Post-residency In-State Retention at Both an Academic Medical Center and in the United States.

This study examines gender representation and in-state retention rates of practicing residency graduates from Pennsylvania State University (PSU), as well as at the national level. PSU and national data were collected from a PSU handbook and the Association of American Medical Colleges (AAMC), respectively. There were significant differences between male and female representation both at PSU and at the national level. Furthermore, there was a significant difference between male and female retention rates nationally. This study demonstrates a true gender discrepancy for graduates from PSU and at the national level. Moving forward, investigating potential causes of this discrepancy may help minimize gender differences.

Residency Specialty and National Resident Matching Program Outcomes as Predictors of Academic vs Non-Academic Position as an Attending Physician.

PURPOSE: Previous studies have shown that research can be used as a predictive factor for an academic career for physicians in the fields of radiation oncology, orthopedic surgery, and diagnostic radiology. We seek to determine if this factor is predictive for all medical specialties based on an analysis of public data on physicians who have trained at Hershey Medical Center (HMC) and public National Resident Matching Program (NRMP) charting outcomes. METHODS: We determined the location and job title of all graduates of HMC residency training programs through a combination of publicly available information on HMC's website and other institutions' websites. We separated these into academic and non-academic positions and performed Chi-square analysis to determine if the number of research experiences was predictive of an academic career. RESULTS: Participating in the residency specialties of general surgery, pathology, internal medicine, and neurological surgery are statistically significant predictors of an academic career upon graduation. The average number of research experiences obtained by matched U.S. medical students is not a statistically significant predictor of an academic career upon graduation. CONCLUSION: In contrast to previously published studies, a higher number of research experiences in medical school is not a significant predictor of an academic career for attending physicians who graduated residency at HMC.

Establishment and Characterization of a Topotecan Resistant Non-small Cell Lung Cancer NCI-H460/TPT10 Cell Line.

While topotecan (TPT) is a first- and second-line chemotherapeutic drug in treating lung cancer, the development of drug resistance in tumors still reserves as a major obstacle to chemotherapeutic success. Therefore, a better understanding of the mechanisms of topotecan resistance is critical. In this study, the first topotecan-resistant human non-small cell lung cancer (NSCLC) cell line, termed NCI-H460/TPT10, was established from the parental NCI-H460 cell line. NCI-H460/TPT10 cells exhibited a 394.7-fold resistance to TPT, and cross-resistance to SN-38, mitoxantrone, and doxorubicin, compared to parental NCI-H460 cells. Overexpression of ABCG2 localized on the cell membrane, but not ABCB1 or ABCC1, was found in NCI-H460/TPT10 cells, indicating that ABCG2 was likely to be involved in topotecan-resistance. This was confirmed by the abolishment of drug resistance in NCI-H460/TPT10 cells after ABCG2 knockout. Moreover, the involvement of functional ABCG2 as a drug efflux pump conferring multidrug resistance (MDR) was indicated by low intracellular accumulation of TPT in NCI-H460/TPT10 cells, and the reversal effects by ABCG2 inhibitor Ko143. The NCI-H460/TPT10 cell line and its parental cell line can be useful for drug screening and developing targeted strategies to overcome ABCG2-mediated MDR in NSCLC.

Infrainguinal open reconstruction: a review of surgical considerations and expected outcomes.

Infrainguinal arterial occlusive disease can lead to potentially disabling and limb-threatening conditions. Revascularization may be indicated for claudication, rest pain, or tissue loss. Although endovascular interventions are becoming more prevalent, open surgeries such as endarterectomy and bypass are still needed and performed regularly. Open reconstruction has been associated with postoperative morbidity, both at the local and at the systemic levels. Local complications include surgical site infections (SSIs 0-5.3%), graft failure (12-60%), and amputation (5.7-27%), and more systemic issues include cardiac (2.6-18.4%), respiratory (2.5%), renal (4%), neurovascular (1.5%), and thromboembolic (0.2-1%) complications. While such outcomes present an additional challenge to the postoperative management of surgical patients, it may be possible to minimize their occurrence through careful risk stratification and preoperative assessment. Therefore, individualized selection of candidates for open repair requires weighing the need for intervention against the likelihood of adverse outcomes based on preoperative risk factors. This review provides an overview of open reconstruction, focusing on identifying the clinical indications for surgery and perioperative morbidity and mortality.

Staged anticonvulsant screening for chronic epilepsy.

OBJECTIVE: Current anticonvulsant screening programs are based on seizures evoked in normal animals. One-third of epileptic patients do not respond to the anticonvulsants discovered with these models. We evaluated a tiered program based on chronic epilepsy and spontaneous seizures, with compounds advancing from high-throughput in vitro models to low-throughput in vivo models. METHODS: Epileptogenesis in organotypic hippocampal slice cultures was quantified by lactate production and lactate dehydrogenase release into culture media as rapid assays for seizure-like activity and cell death, respectively. Compounds that reduced these biochemical measures were retested with in vitro electrophysiological confirmation (i.e., second stage). The third stage involved crossover testing in the kainate model of chronic epilepsy, with blinded analysis of spontaneous seizures after continuous electrographic recordings. RESULTS: We screened 407 compound-concentration combinations. The cyclooxygenase inhibitor, celecoxib, had no effect on seizures evoked in normal brain tissue but demonstrated robust antiseizure activity in all tested models of chronic epilepsy. INTERPRETATION: The use of organotypic hippocampal cultures, where epileptogenesis occurs on a compressed time scale, and where seizure-like activity and seizure-induced cell death can be easily quantified with biomarker assays, allowed us to circumvent the throughput limitations of in vivo chronic epilepsy models. Ability to rapidly screen compounds in a chronic model of epilepsy allowed us to find an anticonvulsant that would be missed by screening in acute models.

Infantile fibrosarcoma of the hand associated with coagulopathy.

BACKGROUND: Large congenital neoplasms of the extremities may be associated with coagulopathies and significant hemorrhage in the neonatal period. At times, the differences between coagulation derangements can be very subtle, leading to errors in diagnosis. Infants with vascular lesions and coagulopathies are often found to have the Kasabach-Merritt phenomenon, which is a platelet-trapping coagulopathy. However, other neoplasms or vascular malformations can be accompanied by disseminated intravascular coagulation. It is important to obtain accurate diagnoses of the neoplasm and the coagulopathy because the treatments of similar-appearing tumors and coagulopathies can be markedly different. METHODS: The authors report the case of a newborn with a congenital tumor of the left hand that was accompanied by a coagulopathy that caused significant bleeding. RESULTS: A presumption was made by the neonatal critical care physicians and hematologists that the infant had a kaposiform hemangioendothelioma along with the Kasabach-Merritt phenomenon. However, steroid treatment did not reduce the size of the mass or correct the coagulopathy. Only after obtaining consultation with a hand surgeon and a tissue diagnosis was it learned that the patient had an infantile fibrosarcoma that was accompanied by disseminated intravascular coagulation. Limb-sparing resection of the lesion along with chemotherapy markedly improved the patient's condition. CONCLUSIONS: Large congenital neoplasms presenting with attendant bleeding diatheses must be rapidly and accurately diagnosed with both a biopsy-proven tissue diagnosis and a hematologic characterization of the nature of the coagulopathy. The differential diagnosis of a vascular-appearing mass in the extremity can be subtle, and presumptive diagnosis, as occurred in this case, can lead to incorrect or delayed treatment. Specifically, kaposiform hemangioendothelioma must be differentiated from infantile fibrosarcoma. The principles of infantile fibrosarcoma treatment are limb-sparing resection and chemotherapy.