Citations

Cultivation of primary hepatocytes as spheroids creates an efficient three-dimensional model system for hepatic studies in vitro and as a cell source for a spheroid reservoir bioartificial liver. The mechanism of spheroid formation is poorly understood, as is an explanation for why normal, anchorage-dependent hepatocytes remain viable and do not undergo detachment-induced apoptosis, known as anoikis, when placed in suspension spheroid culture. The purpose of this study was to investigate the role of E-cadherin, a calcium-dependent cell adhesion molecule, in the formation and maintenance of hepatocyte spheroids. Hepatocyte spheroids were formed by a novel rocker technique and cultured in suspension for up to 24 h. The dependence of spheroid formation on E-cadherin and calcium was established using an E-cadherin blocking antibody and a calcium chelator. We found that inhibiting E-cadherin prevented cell–cell attachment and spheroid formation, and, surprisingly, E-cadherin inhibition led to hepatocyte death through a caspase-independent mechanism. In conclusion, E-cadherin is required for hepatocyte spheroid formation and may be responsible for protecting hepatocytes from a novel form of caspase-independent cell death.

Background: Laparoscopic ventral hernia repair (LVHR) has gained wide acceptance by both surgeons and patients, but hernias that approach a bony prominence are more complex due to the difficulty of proper fixation. This study was conducted to evaluate the use of bone anchor mesh fixation for complex LVHR. Methods: A prospective study of patients having complex LVHR with bone anchors was conducted using patients from 2 academic institutions between July 2003 and December 2007. Patient demographic data, characteristics of the hernia, operative details, and postoperative outcomes were recorded. Results: A total of 30 patients who had LVHR using bone anchors were evaluated (20 women, 10 men; mean age 60.9 years, range 41-83 years). In all, 17 suprapubic and 13 lateral hernias were included, requiring a mean of 2.8 and 3.2 bone anchors, respectively. The average hernia defect was 263 cm 2 (range 35-690 cm 2 ), and the average mesh size was 663 cm 2 (range 255-1360 cm 2 ). Mean operative time was 218 minutes (range 98-420 minutes), with an estimated blood loss of 46 mL (range 10-100 mL). The average length of stay was 5.2 days (range 1-26 days). Seven patients (23.3%) developed postoperative complications, and 1 patient in this study died (mortality 3.3%). During follow-up of 13.2 months (range 1-26 months), 2 patients (6.7%) developed a recurrent hernia. Conclusions: Bone anchors can be used successfully in the laparoscopic repair of complex ventral hernias, particularly with suprapubic and lateral hernias that approach a bony prominence. The complication rate is acceptable, with a short hospital stay and low recurrence rate.

Purpose Early clinical studies with gefitinib showed promising efficacy and mild toxicity in patients with advanced non–small-cell lung cancer (NSCLC). Thus, gefitinib was an ideal agent to evaluate in a maintenance setting in stage III disease. Patients and Methods Untreated patients with stage III NSCLC, a performance score of 0 to 1, and adequate organ function were eligible. All patients received cisplatin 50 mg/m 2 on days 1 and 8 plus etoposide 50 mg/m 2 on days 1 to 5, every 28 days for two cycles with concurrent thoracic radiation (1.8- to 2-Gy fractions per day; total dose, 61 Gy) followed by three cycles of docetaxel 75 mg/m 2 . Patients whose disease did not progress were randomly assigned to gefitinib 250 mg/d or placebo until disease progression, intolerable toxicity, or the end of 5 years. The planned sample size was 672 patients to confer power of 0.89 to detect a 33% increase over the expected median survival time of 21 months (one-sided P = .025, log-rank test). Random assignment was stratified by stage, histology, and measurable versus nonmeasurable disease. Results Enrollment began in July 2001. An unplanned interim analysis conducted in April 2005 rejected the alternative hypothesis of improved survival at the P = .0015 level for 243 randomly assigned patients. The study closed, and preliminary results were reported. Now, with a median follow-up time of 27 months, median survival time was 23 months for gefitinib (n = 118) and 35 months for placebo (n = 125; two-sided P = .013). The toxic death rate was 2% with gefitinib compared with 0% for placebo. Conclusion In this unselected population, gefitinib did not improve survival. Decreased survival was a result of tumor progression and not gefitinib toxicity.

Phenylethanolamine N-methyltransferase (PNMT) catalyzes the synthesis of epinephrine from norepinephrine. We previously identified and functionally characterized common sequence variation in the PNMT gene. In the present study, we set out to determine whether common PNMT genetic polymorphisms might be associated with individual variation in circulating epinephrine levels during exercise in 74 Caucasian American subjects. Circulating epinephrine levels were measured in each subject at baseline and during two different levels of exercise, ∼40% and ∼75% of peak workload. The PNMT gene was resequenced with DNA from each study subject. Eight novel PNMT polymorphisms were identified, including a C319T (Arg107Cys) nonsynonymous single nucleotide polymorphism (SNP) and I1G(280)A, a SNP located in the first intron of the gene. The I1G(280)A SNP was significantly associated with decreased exercise-induced circulating epinephrine levels and with a decreased epinephrine-to-norepinephrine ratio. The Cys107 recombinant allozyme displayed significantly lower levels of both PNMT activity and immunoreactive protein than the wild-type allozyme after transfection into COS-1 cells, but it did not appear to be associated with level of epinephrine in these subjects. Electrophoretic mobility shift and reporter gene assays performed with the I1G(280)A SNP indicated that this polymorphism could bind nuclear proteins and might modulate gene transcription. Our studies suggest that functionally significant variant sequence in the human PNMT gene might contribute to individual variation in levels of circulating epinephrine during exercise.

Purpose To update the recommendations for the use of bisphosphonates in the prevention and treatment of bone disease in multiple myeloma. The Update Committee expanded the guideline to include a discussion of osteonecrosis of the jaw (ONJ). Methods For the 2007 update, an Update Committee composed of members from the full panel completed a review and analysis of data published since 2002. Searches of Medline and the Cochrane Collaboration Library databases were performed. Recommendations For multiple myeloma patients who have, on plain radiograph(s) or imaging studies, lytic destruction of bone or spine compression fracture from osteopenia, intravenous pamidronate 90 mg delivered over at least 2 hours or zoledronic acid 4 mg delivered over at least 15 minutes every 3 to 4 weeks is recommended. Clodronate is an alternative bisphosphonate approved worldwide, except in the United States, for oral or intravenous administration. New dosing guidelines for patients with pre-existing renal impairment were added to the zoledronic acid package insert. Although no similar dosing guidelines are available for pamidronate, the Update Committee recommends that clinicians consider reducing the initial pamidronate dose in patients with pre-existing renal impairment. Zoledronic acid has not been studied in patients with severe renal impairment and is not recommended in this setting. The Update Committee suggests that bisphosphonate treatment continue for a period of 2 years. At 2 years, physicians should seriously consider discontinuing bisphosphonates in patients with responsive or stable disease, but further use is at the discretion of the treating physician. The Update Committee also discusses measures regarding ONJ.

Adoptive T cell therapy, involving the ex vivo selection and expansion of antigen-specific T cell clones, provides a means of augmenting antigen-specific immunity without the in vivo constraints that can accompany vaccine-based strategies. A phase I study was performed to evaluate the safety, in vivo persistence, and efficacy of adoptively transferred CD8 + T cell clones targeting the tumor-associated antigens, MART1/MelanA and gp100 for the treatment of patients with metastatic melanoma. Four infusions of autologous T cell clones were administered, the first without IL-2 and subsequent infusions with low-dose IL-2 (at 0.25, 0.50, and 1.0 × 10 6 units/m 2 twice daily for the second, third, and fourth infusions, respectively). Forty-three infusions of MART1/MelanA-specific or gp100-specific CD8 + T cell clones were administered to 10 patients. No serious toxicity was observed. We demonstrate that the adoptively transferred T cell clones persist in vivo in response to low-dose IL-2, preferentially localize to tumor sites and mediate an antigen-specific immune response characterized by the elimination of antigen-positive tumor cells, regression of individual metastases, and minor, mixed or stable responses in 8 of 10 patients with refractory, metastatic disease for up to 21 mo.

Current strategies for the immunotherapy of melanoma include augmentation of the immune response to tumor antigens represented by melanosomal proteins such as tyrosinase, gp100, and MART-1. The possibility that intentional targeting of tumor antigens representing normal proteins can result in autoimmune toxicity has been postulated but never demonstrated previously in humans. In this study, we describe a patient with metastatic melanoma who developed inflammatory lesions circumscribing pigmented areas of skin after an infusion of MART-1–specific CD8+ T cell clones. Analysis of the infiltrating lymphocytes in skin and tumor biopsies using T cell–specific peptide–major histocompatibility complex tetramers demonstrated a localized predominance of MART-1–specific CD8+ T cells (>28% of all CD8 T cells) that was identical to the infused clones (as confirmed by sequencing of the complementarity-determining region 3). In contrast to skin biopsies obtained from the patient before T cell infusion, postinfusion biopsies demonstrated loss of MART-1 expression, evidence of melanocyte damage, and the complete absence of melanocytes in affected regions of the skin. This study provides, for the first time, direct evidence in humans that antigen-specific immunotherapy can target not only antigen-positive tumor cells in vivo but also normal tissues expressing the shared tumor antigen.