Yvonne M. Mowery

Bariatric Surgery for Severely Obese Adolescents

A 1991 National Institutes of Health Consensus Conference concluded that severely obese adults could be eligible for bariatric surgery if they had a body mass index (BMI) ≥35 kg/m2 with or ≥40 kg/m2 without obesity comorbidity. It was thought at that time that there were inadequate data to support bariatric surgery in severely obese adolescents. An estimated 25% of children in the United States are obese, a number that has doubled over a 30-year period. Very little information has been published on the subject of obesity surgery in adolescents. Therefore we reviewed our 20-year database on bariatric surgery in adolescents. Severely obese adolescents, ranging from 12 to less than 18 years of age, were considered eligible for bariatric surgery according to the National Institutes of Health adult criteria. Gastroplasty was the procedure of choice in the initial 3 years of the study followed by gastric bypass, which was found to be significantly more effective for weight loss in adults. Distal gastric bypass (D-GBP) was used in extremely obese patients (BMI ≥60 kg/m2) before 1992 and long-limb gastric bypass (LL-GBP) was used for super-obese patients (BMI ≥50 kg/m2) after 1992. Laparoscopic gastric bypass was used after 2000. Thirty-three adolescents (27 white, 6 black; 19 females, 14 males) underwent the following bariatric operations between 1981 and June 2001: horizontal gastroplasty in one, vertical banded gastroplasty in two, standard gastric bypass in 17 (2 laparoscopic), LL-GBP in 10, and D-GBP in three. Mean BMI was 52 ±11 kg/m2 (range 38 to 91 kg/m2), and mean age was 16 ± 1 years (range 12.4 to 17.9 years). Preoperative comorbid conditions included the following: type II diabetes mellitus in two patients, hypertension in 11, pseudotumor cerebri in three, gastroesophageal reflux in five, sleep apnea in six, urinary incontinence in two, polycystic ovary syndrome in one, asthma in one, and degenerative joint disease in 11. There were no operative deaths or anastomotic leaks. Early complications included pulmonary embolism in one patient, major wound infection in one, minor wound infections in four, stomal stenoses (endoscopically dilated) in three, and marginal ulcers (medically treated) in four. Late complications included small bowel obstruction in one and incisional hernias in six patients. There were two late sudden deaths (2 years and 6 years postop-eratively), but these were unlikely to have been caused by the bariatric surgical procedure. Revision procedures included one D-GBP to gastric bypass for malnutrition and one gastric bypass to LL-GBP for inadequate weight loss. Regain of most or all of the lost weight was seen in five patients at 5 to 10 years after surgery; however, significant weight loss was maintained in the remaining patients for up to 14 years after surgery. Comorbid conditions resolved at 1 year with the exception of hypertension in two patients, gastroesophageal reflux in two, and degenerative joint disease in seven. Self-image was greatly enhanced; eight patients have married and have children, five patients have completed college, and one patient is currently in college. Severe obesity is increasing rapidly in adolescents and is associated with significant comorbidity and social stigmatization. Bariatric surgery in adolescents is safe and is associated with significant weight loss, correction of obesity comorbidity, and improved self-image and socialization. These data strongly support obesity surgery for those unfortunate individuals who may have difficulty obtaining insurance coverage based on the 1991 National Institutes of Health Consensus Conference statement.

Training the novice in laparoscopy: More challenge is better

Background: Virtual reality simulation is effective in training the novice to perform basic laparoscopic skills. Methods: Using the Minimally Invasive Surgery Training—Virtual Reality (MIST-VR) trainer, 27 honors high school students were tested at the easy level, prospectively randomized to eight training sessions at the easy (group A, n = 14) or medium (group B, n = 13) level, then retested at the easy level. Results: Both groups were statistically similar at baseline. All scores improved significantly (50.1% to 81.3%) over the period of training (p < 0.05). Although the group A scores were significantly better than the group B scores throughout training (p < 0.05), on final testing at the easy level, group B surpassed group A for all the tasks except TransferPlace (p = 0.054). Conclusions: Virtual simulation is an effective laparoscopic training method for the novice, providing significant improvement in skill levels over a relatively short period. More challenging training seems to predict greater improvement over time and better final skill levels.

Ligation of cancer cell surface GRP78 with antibodies directed against its COOH-terminal domain up-regulates p53 activity and promotes apoptosis

Binding of activated α2-macroglobulin to GRP78 on the surface of human prostate cancer cells promotes proliferation by activating signaling cascades. Autoantibodies directed against the activated α2-macroglobulin binding site in the NH2-terminal domain of GRP78 are receptor agonists, and their presence in the sera of cancer patients is a poor prognostic indicator. We now show that antibodies directed against the GRP78 COOH-terminal domain inhibit [3H]thymidine uptake and cellular proliferation while promoting apoptosis as measured by DNA fragmentation, Annexin V assay, and clonogenic assay. These antibodies are receptor antagonists blocking autophosphorylation and activation of GRP78. Using 1-LN and DU145 prostate cancer cell lines and A375 melanoma cells, which express GRP78 on their cell surface, we show that antibodies directed against the COOH-terminal domain of GRP78 up-regulate the tumor suppressor protein p53. By contrast, antibody directed against the NH2-terminal domain of GRP78 shows negligible effects on p53 expression. PC-3 prostate cancer cells, which do not express GRP78 on their cell surface, are refractory to the effects of anti-GRP78 antibodies directed against either the COOH- or NH2-terminal domains. However, overexpression of GRP78 in PC-3 cells causes translocation of GRP78 to the cell surface and promotes apoptosis when these cells are treated with antibody directed against its COOH-terminal domain. Silencing GRP78 or p53 expression by RNA interference significantly blocked the increase in p53 induced by antibodies. Antibodies directed against the COOH-terminal domain may play a therapeutic role in cancer patients whose tumors trigger the production of autoantibodies directed against the NH2-terminal domain of GRP78. [Mol Cancer Ther 2009;8(5):1350–62]

Angiostatin-like activity of a monoclonal antibody to the catalytic subunit of F1F0 ATP synthase

The antiangiogenic protein angiostatin inhibits ATP synthase on the endothelial cell surface, blocking cellular proliferation. To examine the specificity of this interaction, we generated monoclonal antibodies (mAb) directed against ATP synthase. mAb directed against the beta-catalytic subunit of ATP synthase (MAb3D5AB1) inhibits the activity of the F(1) domain of ATP synthase and recognizes the catalytic beta-subunit of ATP synthase. We located the antibody recognition site of MAb3D5AB1 in domains containing the active site of the beta-subunit. MAb3D5AB1 also binds to purified Escherichia coli F(1) with an affinity 25-fold higher than the affinity of angiostatin for this protein. MAb3D5AB1 inhibits the hydrolytic activity of F(1) ATP synthase at lower concentrations than angiostatin. Like angiostatin, MAb3D5AB1 inhibits ATP generation by ATP synthase on the endothelial cell surface in acidic conditions, the typical tumor microenvironment where cell surface ATP synthase exhibits greater activity. MAb3D5AB1 disrupts tube formation and decreases intracellular pH in endothelial cells exposed to low extracellular pH. Neither angiostatin nor MAb3D5AB1 showed an antiangiogenic effect in the corneal neovascularization assay; however, both were effective in the low-pH environment of the chicken chorioallantoic membrane assay. Thus, MAb3D5AB1 shows angiostatin-like properties superior to angiostatin and may be exploited in cancer chemotherapy.

Clinical aspects of monoclonal B-cell lymphocytosis.

BACKGROUND Monoclonal B-cell lymphocytosis (MBL) is an asymptomatic precursor condition for chronic lymphocytic leukemia (CLL). It is defined by the presence of small clones of aberrant B cells in the peripheral blood, with a total B-cell count below the threshold for diagnosis of CLL (<5.0x10(9) cells/L). METHODS The authors review current literature on the prevalence of MBL, and the clinical course of this CLL precursor condition, and recommended management for individuals with MBL. RESULTS MBL occurs in approximately 4% to 5% of healthy adults. While most cases of CLL are preceded by MBL, progression to leukemia requiring CLL treatment occurs in only 1% to 2% of individuals with MBL per year. The absolute B-cell count is most strongly associated with progression, and patients with low-count MBL identified in population screening studies rarely develop CLL. Studies are ongoing to better define the relationship between MBL and CLL and to identify prognostic indicators that predict which patients will progress to CLL. Given their elevated risk of developing malignancy, individuals with clinical MBL should be monitored at least annually for progressive lymphocytosis and signs or symptoms of CLL. CONCLUSIONS Many of the epidemiologic and genetic factors associated with MBL development and its progression to CLL have not yet been identified. However, ongoing studies by many research groups are aimed at answering these questions to facilitate management of individuals with this premalignant condition. In addition, active investigation of MBL will likely yield new insights into the biology of CLL, potentially identifying new therapeutic targets for this incurable disease.

Targeting cell surface F1F0 ATP synthase in cancer therapy

Commentary to: Effect of a novel inhibitory mAb antibody against β-subunit of F1F0 ATPase on HCC Jingbo Wang, Ying Han, Jie Liang, Xin Cheng , Li Yan, Yingmei Wang, Jingmei Liu, Guanhong Luo, Xiong Cheng, Lina Zhao, Xinmin Zhou, Kaichun Wu and Daiming Fan

Loss of cell surface TFII-I promotes apoptosis in prostate cancer cells stimulated with activated α2-macroglobulin

Receptor‐recognized forms of α2‐macroglobulin (α2M*) bind to cell surface‐associated GRP78 and initiate pro‐proliferative and anti‐apoptotic signaling. Ligation of GRP78 with α2M* also upregulates TFII‐I, which binds to the GRP78 promoter and enhances GRP78 synthesis. In addition to its transcriptional functions, cytosolic TFII‐I regulates agonist‐induced Ca2+ entry. In this study we show that down regulation of TFII‐I gene expression by RNAi profoundly impairs its cell surface expression and anti‐apoptotic signaling as measured by significant reduction of GRP78, Bcl‐2, and cyclin D1 in 1‐Ln and DU‐145 human prostate cancer cells stimulated with α2M*. In contrast, this treatment significantly increases levels of the pro‐apoptotic proteins p53, p27, Bax, and Bak and causes DNA fragmentation. Furthermore, down regulation of TFII‐I expression activates agonist‐induced Ca2+ entry. In plasma membrane lysates p‐PLCγ1, TRPC3, GRP78, MTJ1, and caveolin co‐immunoprecipitate with TFII‐I suggesting multimeric complexes of these proteins. Consistent with this hypothesis, down regulating TFII‐I, MTJ1, or GRP78 expression by RNAi greatly attenuates cell surface expression of TFII‐I. In conclusion, we demonstrate that not only does cell surface GRP78 regulate apoptosis, but it also regulates Ca2+ homeostasis by controlling cell surface localization of TFII‐I. J. Cell. Biochem. 112: 1685–1695, 2011.

Stall encodes an ADAMTS metalloprotease and interacts genetically with Delta in Drosophila ovarian follicle formation.

Ovarian follicle formation in Drosophila melanogaster requires stall (stl) gene function, both within and outside the ovary, for follicle individualization, stalk cell intercalation, and oocyte localization. We have identified the stl transcript as CG3622 and confirmed the presence of three alternatively spliced isoforms, contrary to current genome annotation. Here we show that the gene is expressed in both ovarian and brain tissues, which is consistent with previous evidence of an ovary nonautonomous function. On the basis of amino acid sequence, stl encodes a metalloprotease similar to the “a disintegrin and metalloprotease with thrombospondin” (ADAMTS) family. Although stl mutant ovaries fail to maintain the branched structure of the fusome and periodically show improperly localized oocytes, stl mutants do not alter oocyte determination. Within the ovary, stl is expressed in pupal basal stalks and in adult somatic cells of the posterior germarium and the follicular poles. Genetically, stl exhibits a strong mutant interaction with Delta (Dl), and Dl mutant ovaries show altered stl expression patterns. Additionally, a previously described genetic interactor, daughterless, also modulates stl expression in the somatic ovary and may do so directly in its capacity as a basic helix-loop-helix (bHLH) transcription factor. We propose a complex model of long-range extraovarian signaling through secretion or extracellular domain shedding, together with local intraovarian protein modification, to explain the dual sites of Stl metalloprotease function in oogenesis.

Neoadjuvant long-course chemoradiation remains strongly favored over short-course radiotherapy by radiation oncologists in the United States

Short‐course radiotherapy (SC‐RT) and long‐course chemoradiotherapy (LC‐CRT) are accepted neoadjuvant treatments of rectal cancer. In the current study, the authors surveyed US radiation oncologists to assess practice patterns and attitudes regarding SC‐RT and LC‐CRT for patients with rectal cancer.

Generation and comparison of CRISPR-Cas9 and Cre-mediated genetically engineered mouse models of sarcoma

Genetically engineered mouse models that employ site-specific recombinase technology are important tools for cancer research but can be costly and time-consuming. The CRISPR-Cas9 system has been adapted to generate autochthonous tumours in mice, but how these tumours compare to tumours generated by conventional recombinase technology remains to be fully explored. Here we use CRISPR-Cas9 to generate multiple subtypes of primary sarcomas efficiently in wild type and genetically engineered mice. These data demonstrate that CRISPR-Cas9 can be used to generate multiple subtypes of soft tissue sarcomas in mice. Primary sarcomas generated with CRISPR-Cas9 and Cre recombinase technology had similar histology, growth kinetics, copy number variation and mutational load as assessed by whole exome sequencing. These results show that sarcomas generated with CRISPR-Cas9 technology are similar to sarcomas generated with conventional modelling techniques and suggest that CRISPR-Cas9 can be used to more rapidly generate genotypically and phenotypically similar cancers.