A Drug Screen using Human iPSC-Derived Hepatocyte-like Cells Reveals Cardiac Glycosides as a Potential Treatment for Hypercholesterolemia.

Efforts to identify pharmaceuticals to treat heritable metabolic liver diseases have been hampered by the lack of models. However, cells with hepatocyte characteristics can be produced from induced pluripotent stem cells (iPSCs). Here, we have used hepatocyte-like cells generated from homozygous familial hypercholesterolemia (hoFH) iPSCs to identify drugs that can potentially be repurposed to lower serum LDL-C. We found that cardiac glycosides reduce the production of apolipoprotein B (apoB) from human hepatocytes in culture and the serum of avatar mice harboring humanized livers. The drugs act by increasing the turnover of apoB protein. Analyses of patient medical records revealed that the treatment of patients with cardiac glycosides reduced serum LDL-C levels. These studies highlight the effectiveness of using iPSCs to screen for potential treatments for inborn errors of hepatic metabolism and suggest that cardiac glycosides could provide an approach for reducing hepatocyte production of apoB and treating hypercholesterolemia.

Clinical, functional, and radiographic outcomes following total knee arthroplasty with patient-specific instrumentation, computer-assisted surgery, and manual instrumentation: a short-term follow-up study.

PURPOSE: The purpose of this study was to evaluate clinical, functional, and radiographic outcomes following total knee arthroplasty (TKA) performed with patient-specific instrumentation (PSI), computer-assisted surgery (CAS), and manual instruments at short-term follow-up. METHODS: 122 TKAs were performed by a single surgeon: 42 with PSI, 38 with CAS, and 40 with manual instrumentation. Preoperative, 1-month, and 6-month clinical and functional outcomes were measured using the Knee Society scoring system (knee score, function score, range of motion, and pain score). Improvements in clinical and functional outcomes from the preoperative to postoperative period were analyzed. Preoperative and postoperative radiographs were measured to evaluate limb and component alignment. RESULTS: Preoperative, 1-month postoperative, and 6-month postoperative knee scores, function scores, range of motion, and pain scores were highest in the PSI group compared to CAS and manual instrumentation. At 6-month follow-up, PSI TKA was associated with a statistically significant improvement in functional score when compared to manual TKA. Otherwise, there were no statistically significant differences in improvements among PSI, CAS, and manual TKA groups. CONCLUSION: The higher preoperative scores in the PSI group limits the ability to draw definitive conclusions from the raw postoperative scores, but analyzing the changes in scores revealed that PSI was associated with a statistically significant improvement in Knee Society Functional score at 6-month post-TKA as compared to CAS or manual TKA. This may be attributable to improvements in component rotation and positioning, improved component size accuracy, or other factors that are not discernible on plain radiograph.

Computer-assisted versus manual TKA: no difference in clinical or functional outcomes at 5-year follow-up.

The purpose of this study was to determine whether differences in clinical, functional, or radiographic outcomes existed at 5-year follow-up between patients who underwent computer-assisted or manual total knee arthroplasty (TKA). Seventy-eight consecutive TKAs were performed by a single surgeon who had extensive experience performing computer-assisted and manual TKA. The manual group (n=40) and computer-assisted group (n=38) were similar with regard to age, sex, diagnosis, body mass index, surgical technique, implants, perioperative management, Knee Society scores, and anteroposterior mechanical axis. Sixty-three (manual group, n=34; computer-assisted group, n=29) patients were available for final follow-up. At 5-year follow-up, no statistically significant differences were found in Knee Society knee score (P=.289), function score (P=.272), range of motion (P=.284), pain score (P=.432), or UCLA activity score (P=.109) between the 2 groups. Postoperative radiographs showed a significant difference in the mechanical axis (P=.004) between the 2 groups; however, both groups achieved a neutral mechanical axis of ±3° (computer-assisted group mean, 2.0°; manual group mean, -0.24°).When TKA was performed by an experienced surgeon, no significant difference was identified at 5-year follow-up between patients who underwent computer-assisted vs manual TKA.

Component sizing in total knee arthroplasty: patient-specific guides vs. computer-assisted navigation.

INTRODUCTION: Patient-specific guides (PSG) and computer-assisted navigation (CAN) are technologies that have been developed to improve the accuracy and reproducibility of total knee arthroplasty (TKA). The purpose of this study is to compare the methodology by which a PSG system and an intraoperative navigation system (CAN) perform an anatomical registration and correctly predict femoral component size in TKA. METHODS: One hundred and eleven PSG TKA were performed, 30 of which were concurrently evaluated with CAN. PSG-predicted and CAN-predicted femoral component size were compared with the actual component selection. The process by which PSG and CAN determines component sizing was evaluated. RESULTS: The PSG system was both more accurate and more precise than the CAN navigation system in predicting femoral component size in TKA. CONCLUSION: In this study, the surgeon's final component selection was more likely to be in accordance with the PSG rather than the CAN sizing algorithm. This study suggests that intraoperative surface registration may not be as accurate as preoperative three-dimensional magnetic resonance imaging reconstructions for establishing optimal femoral component sizing.

Wound complications in joint arthroplasty: comparing traditional and modern methods of skin closure.

Various methods of skin closure exist in joint replacement surgery. Although subcuticular skin closure techniques offer an aesthetic advantage over conventional skin stapling, no measurable differences have been reported. Furthermore, newer barbed sutures, such as the V-Loc absorbable suture (Covidien, Mansfield, Massachusetts), theoretically distribute tension evenly through the wound and help decrease knot-related complications. The purpose of this study was to evaluate whether wound complication rates were (1) lower in V-Loc closure cases as theoretically suggested, (2) lower for subcuticular closure vs staples, and (3) significantly different for knee and hip joint reconstruction.A retrospective chart review was conducted of 278 consecutive cases of primary joint reconstruction performed by a single surgeon (L.P.). The study group comprised 106 men and 161 women. Average patient age at surgery was 63 years (range, 18-92 years), and average body mass index of the cohort was 33.7 kg/m(2) (range, 25-51 kg/m(2)). Skin was closed via staple gun or subcuticular stitch (3-0 Biosyn [Covidien] vs V-Loc). Seven (3.9%) wound complications occurred in 181 cases closed with staples. Four (7.8%) wound complications occurred in 51 cases closed via subcuticular Biosyn suture. Six (13.0%) wound complications occurred in 46 cases closed with V-Loc suture. The staple group had a lower rate of complications when compared with the suture group as a whole (P=.033) and when compared specifically with the V-Loc suture group (P=.017).

Thyroid hormone replacement in women of reproductive age: is surgeon knowledge related to operative volume?

BACKGROUND: It is not known if surgeons who place women of reproductive age on thyroid hormone replacement (levothyroxine, LT4) routinely inform them of the increased LT4 demands with future pregnancy. In addition, it is not clear whether reading the 2007 Endocrine Society's "Guidelines on the Management of Thyroid Dysfunction during Pregnancy and Postpartum" influences the role of the surgeon in patient education. The objective of this study was to identify the role of the surgeon in patient education at the time of initiation of LT4 therapy. METHODS: A two-sided one-page survey was distributed to the 260 surgeons attending the 2009 American Association of Endocrine Surgeons' meeting. Of those distributed, 109 (42%) surgeons returned the survey. RESULTS: Although only 26/109 (23%) read the 2007 Endocrine Society's "Guidelines on the Management of Thyroid Dysfunction during Pregnancy and Postpartum," reading the guidelines was associated with a significantly greater likelihood of informing patients of higher LT4 requirements with pregnancy (p < 0.0001). Eighty-five percent of those who read the guidelines "often" or "always" informed patients of higher LT4 requirements with future pregnancy, whereas only 44% of those who did not read the guidelines provided the same level of education. After controlling for surgeon sex, academic versus private practice, years in practice, and number of surgeries performed in 2008, the only independent predictor of patient education was reading the guidelines (p = 0.006). On multivariable analysis, surgeon volume was associated with reading the guidelines (p = 0.006). The mean number of thyroid surgeries performed by those who read the guidelines versus those who did not was 164.46 +/- 16.98 versus 115.01 +/- 8.27 (p = 0.005). CONCLUSION: Surgeons who read the Endocrine Society's "Guidelines on the Management of Thyroid Dysfunction during Pregnancy and Postpartum" were significantly more likely to inform patients of the need for higher LT4 doses with pregnancy. Thyroid surgery volume was associated with guideline awareness.

Sodium butyrate activates Notch1 signaling, reduces tumor markers, and induces cell cycle arrest and apoptosis in pheochromocytoma.

BACKGROUND: Pheochromocytoma is a neuroendocrine (NE) tumor of the adrenal medulla for which surgical resection is the only therapy. However, 10-46% of tumors are metastatic or have malignant features, and are often inoperable. Our lab has demonstrated the importance of the Notch1 signaling pathway in NE neoplasia, indicating that this pathway could be a target for emergent treatments in pheochromocytoma. It has recently become clear that histone deacetylase (HDAC) inhibitors influence Notch1 signaling. We hypothesized that the HDAC inhibitor Sodium Butyrate (NaB) might activate Notch1 in pheochromocytoma resulting in altered tumor cell proliferation. METHODS: Pheochromocytoma (PC-12) cells were treated with increasing concentrations of NaB. MTT cellular proliferation assay was used to determine the effect of NaB on PC-12 cell growth. Expression of Notch1, NE markers, and cell cycle proteins was studied using Western analysis. RESULTS: Untreated PC-12 cells lack Notch1 activity. Treatment with NaB led to a dose-dependent induction of Notch1 signaling, reduction of NE markers ASCL1 and CgA, and a significant reduction in cellular proliferation. Levels of expression of cyclin D1, p21, cleaved PARP, and cleaved caspase 3 proteins indicated the presence of cell cycle arrest and apoptosis following NaB treatment. CONCLUSION: NaB activated Notch1 signaling, inhibited cellular proliferation, reduced NE markers, and induced cell cycle arrest and apoptosis in pheochromocytoma cells. This data indicates that activation of Notch1 signaling is a promising potential therapy or palliative measure for pheochromocytoma that warrants further investigation.

Papillary thyroid microcarcinomas: big decisions for a small tumor.

BACKGROUND: The clinical significance of papillary thyroid microcarcinoma (PTMC) is debated, and therefore the rise in incidence of PTMC creates management dilemmas. The following study evaluates factors influencing decisions to treat. MATERIALS AND METHODS: Between 1994 and 2007, 1361 patients underwent thyroid surgery at a single institution. Of these patients, 107 were diagnosed with PTMC. The type of surgical intervention, likelihood of referral to an endocrinologist, use of radioactive iodine, and administration of suppressive doses of levothyroxine (LT4) were analyzed in relation to patient and tumor characteristics. RESULTS: Multifocality and larger size were predictive of which patients underwent total thyroidectomy on multivariable logistic regression (P=.004 and P=.001, respectively). Larger mean tumor size, 0.62+/-0.004 versus 0.34+/-0.006 cm, was independently associated with increased likelihood of endocrine referral (P=.029). Multifocality, diagnosis via FNA preoperatively, larger mean size of PTMC, and endocrine referral were independently associated with increased likelihood of receiving radioactive iodine (RAI). On multivariable analysis, only total thyroidectomy and endocrine referral were independently associated with treatment with suppressive doses of LT4 (P=.001 and .001, respectively). In the 47 patients with unifocal PTMC<0.8 cm diameter, the mean size of tumor focus was larger in the subgroup undergoing total thyroidectomy (P=.004). Surprisingly, in these very low risk PTMC patients, the likelihood of RAI for remnant ablation was independently associated with younger patient age (P=.029). In the subgroup with unifocal<0.8 cm disease, the mean age of patients receiving RAI was 34+/-3.3 years versus 48+/-2.3 years in those not receiving RAI (P=.003). CONCLUSIONS: The decision tree in the management of PTMC is beginning at the time of surgery, and referral to endocrinology is associated with a more aggressive course. Younger age is predictive of RAI administration in the lowest-risk PTMC patients.

Valproic acid activates Notch1 signaling and induces apoptosis in medullary thyroid cancer cells.

OBJECTIVE: To examine the effects of valproic acid (VPA) on Notch1 expression and cancer cell proliferation in medullary thyroid cancer (MTC) cells. BACKGROUND: Other than surgery, there are no effective treatments for MTC, a neuroendocrine malignancy that frequently metastasizes. We have previously shown that over-expression of Notch1 in MTC cells inhibits cell growth and hormone production. VPA, a drug long used for the treatment of epilepsy, has recently been identified as a potential Notch1 activator. We hypothesized that VPA might activate Notch1 signaling in MTC cells, with antiproliferative effects. METHODS: Human MTC cells were treated with VPA (0-5 mM) and Western blotting was performed to measure levels of Notch1 pathway proteins and neuroendocrine tumor markers. After confirming that VPA is a Notch1 activator in MTC cells, we performed cell proliferation assay. Finally, to determine the mechanism of growth inhibition, we measured protein levels of various markers of apoptosis. RESULTS: Notch1 was absent in MTC cells at baseline. VPA treatment resulted in an increase in both full-length and active Notch1 protein. Notch1 activation with VPA suppressed 2 neuroendocrine tumor markers, ASCL1 and chromogranin A. Importantly, VPA inhibited the growth of MTC cells in a dose-dependent manner. Immunoblot analysis demonstrated caspase activation and poly(ADP-ribose) polymerase cleavage, indicating the induction of apoptosis. CONCLUSIONS: VPA activates Notch1 signaling in MTC cells and inhibits their growth by inducing apoptosis. As the safety of VPA in human beings is well established, a clinical trial using this drug to treat patients with advanced MTC could be initiated in the near future.

Suberoyl bishydroxamic acid inhibits cellular proliferation by inducing cell cycle arrest in carcinoid cancer cells.

Carcinoid cancers arise from the neuroendocrine cell system of the gastrointestinal tract, lungs, and other organs. Hepatic metastases are common, and patients often suffer from endocrinopathies secondary to tumor secretion of various hormones and peptides. As complete surgical resection is often not possible because of widespread disease, new therapeutic and palliative treatments are needed. In this study, we characterized the effects of suberoyl bishydroxamic acid (SBHA), a histone deacetylase inhibitor, on the growth and neuroendocrine phenotype of carcinoid cancer cells. SBHA treatment of human gastrointestinal and pulmonary carcinoid cancer cells resulted in a dose-dependent inhibition of cell proliferation. Western blot analysis showed a decrease in cyclin D1 and an increase in p21 and p27, indicating that the mechanism of this growth inhibition is cell cycle arrest. Furthermore, SBHA treatment suppressed two neuroendocrine tumor markers, chromogranin A and achaete-scute complex-like 1. These changes in the growth and neuroendocrine phenotype of carcinoid cells were associated with activation of the Notch1 signaling cascade. We conclude that SBHA shows promise as a potential anticancer agent for the treatment of patients with advanced carcinoid tumor disease.