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1.  Mutations in TJP2 cause progressive cholestatic liver disease 
Nature genetics  2014;46(4):326-328.
The elucidation of genetic causes of cholestasis has proved to be important in understanding the physiology and pathophysiology of the liver. Protein-truncating mutations in the tight junction protein 2 gene (TJP2) are shown to cause failure of protein localisation, with disruption of tight-junction structure leading to severe cholestatic liver disease. This contrasts with the embryonic-lethal knockout mouse, highlighting differences in redundancy in junctional complexes between organs and species.
PMCID: PMC4061468  PMID: 24614073
2.  Maternal cholestasis during pregnancy programs metabolic disease in offspring 
The Journal of Clinical Investigation  2013;123(7):3172-3181.
The intrauterine environment is a major contributor to increased rates of metabolic disease in adults. Intrahepatic cholestasis of pregnancy (ICP) is a liver disease of pregnancy that affects 0.5%–2% of pregnant women and is characterized by increased bile acid levels in the maternal serum. The influence of ICP on the metabolic health of offspring is unknown. We analyzed the Northern Finland birth cohort 1985–1986 database and found that 16-year-old children of mothers with ICP had altered lipid profiles. Males had increased BMI, and females exhibited increased waist and hip girth compared with the offspring of uncomplicated pregnancies. We further investigated the effect of maternal cholestasis on the metabolism of adult offspring in the mouse. Females from cholestatic mothers developed a severe obese, diabetic phenotype with hepatosteatosis following a Western diet, whereas matched mice not exposed to cholestasis in utero did not. Female littermates were susceptible to metabolic disease before dietary challenge. Human and mouse studies showed an accumulation of lipids in the fetoplacental unit and increased transplacental cholesterol transport in cholestatic pregnancy. We believe this is the first report showing that cholestatic pregnancy in the absence of altered maternal BMI or diabetes can program metabolic disease in the offspring.
PMCID: PMC3696570  PMID: 23934127
3.  Morphologic Findings in Progressive Familial Intrahepatic Cholestasis 2 (PFIC2): Correlation With Genetic and Immunohistochemical Studies 
Progressive familial intrahepatic cholestasis, type 2 (PFIC2), characterized by cholestasis in infancy that may progress to cirrhosis, is caused by mutation in ABCB11, which encodes bile salt export pump (BSEP). We correlated histopathologic, immunohistochemical, and ultrastructural features in PFIC2 with specific mutations and clinical course. Twelve patients with clinical PFIC2 and ABCB11 mutations were identified, and 22 liver biopsy and explant specimens were assessed. All had hepatocellular cholestasis; most had canalicular bile plugs. At least 1 specimen from every patient had centrizonal/sinusoidal fibrosis, often with periportal fibrosis. Neonatal hepatitis-like features (inflammation, giant cells, necrosis) varied. In 2 of the 5 patients with paired specimens obtained > 6 months apart, lobular and portal fibrosis worsened. Transmission electron microscopy (EM) in all 9 patients studied showed canalicular dilatation, microvilli loss, abnormal mitochondrial internal structure, and varying intra-canalicular accumulation of finely granular bile. Canalicular staining for BSEP was absent in 10 patients and present in 2 patients, 1 of whom had intermittent symptoms. ABCB11 sequencing of all patients identified 6 novel and 10 previously described mutations, with nonsense, missense, and/or noncoding mutations in the 10 patients without immunohistochemically demonstrable BSEP. Missense and/or noncoding mutations were identified in the 2 patients with demonstrable BSEP, whose clinical course was more indolent. Mutations ending ABCB11 transcription appear linked, through hepatocellular necrosis and fibrosis, to worse outcome. In conclusion, light microscopy and electron microscopy findings in clinical PFIC2 can support diagnosis, but are variable and nonspecific. Therefore, no correlation between specific mutations and histopathology is yet possible.
PMCID: PMC3416050  PMID: 21490445
PFIC2; progressive familial intrahepatic cholestasis; bile salt export pump; BSEP; ABCB11; neonatal hepatitis
4.  Complete OATP1B1 and OATP1B3 deficiency causes human Rotor syndrome by interrupting conjugated bilirubin reuptake into the liver 
Bilirubin, a breakdown product of heme, is normally glucuronidated and excreted by the liver into bile. Failure of this system can lead to a buildup of conjugated bilirubin in the blood, resulting in jaundice. The mechanistic basis of bilirubin excretion and hyperbilirubinemia syndromes is largely understood, but that of Rotor syndrome, an autosomal recessive disorder characterized by conjugated hyperbilirubinemia, coproporphyrinuria, and near-absent hepatic uptake of anionic diagnostics, has remained enigmatic. Here, we analyzed 8 Rotor-syndrome families and found that Rotor syndrome was linked to mutations predicted to cause complete and simultaneous deficiencies of the organic anion transporting polypeptides OATP1B1 and OATP1B3. These important detoxification-limiting proteins mediate uptake and clearance of countless drugs and drug conjugates across the sinusoidal hepatocyte membrane. OATP1B1 polymorphisms have previously been linked to drug hypersensitivities. Using mice deficient in Oatp1a/1b and in the multispecific sinusoidal export pump Abcc3, we found that Abcc3 secretes bilirubin conjugates into the blood, while Oatp1a/1b transporters mediate their hepatic reuptake. Transgenic expression of human OATP1B1 or OATP1B3 restored the function of this detoxification-enhancing liver-blood shuttle in Oatp1a/1b-deficient mice. Within liver lobules, this shuttle may allow flexible transfer of bilirubin conjugates (and probably also drug conjugates) formed in upstream hepatocytes to downstream hepatocytes, thereby preventing local saturation of further detoxification processes and hepatocyte toxic injury. Thus, disruption of hepatic reuptake of bilirubin glucuronide due to coexisting OATP1B1 and OATP1B3 deficiencies explains Rotor-type hyperbilirubinemia. Moreover, OATP1B1 and OATP1B3 null mutations may confer substantial drug toxicity risks.
PMCID: PMC3266790  PMID: 22232210
Gastroenterology  2010;138(7):2388-2398.e2.
Trichohepatoenteric syndrome (THES) is an autosomal recessive disorder characterised by life-threatening diarrhoea in infancy, immunodeficiency, liver disease, trichorrhexis nodosa, facial dysmorphism, hypopigmentation and cardiac defects. We attempted to characterise the phenotype and elucidate the molecular basis of THES.
Twelve patients with classical THES from 11 families had detailed phenotyping. Autozygosity mapping was undertaken in 8 patients from consanguineous families using 250k single nucleotide polymorphism (SNP) arrays and linked regions evaluated using microsatellite markers. Linkage was confirmed to one region from which candidate genes were analysed. The effect of mutations on protein production and/or localisation in hepatocytes and intestinal epithelial cells from affected patients was characterised by immunohistochemistry.
Previously unrecognised platelet abnormalities (reduced platelet α-granules, unusual stimulated alpha granule content release, abnormal lipid inclusions, abnormal platelet canalicular system and reduced number of microtubules) were identified. The THES locus was mapped to 5q14.3 – 5q21.2. Sequencing of candidate genes demonstrated mutations in TTC37, which encodes the uncharacterised tetratricopeptide repeat protein, thespin. Bioinformatic analysis suggested thespin to be involved in protein-protein interactions or chaperone. Preliminary studies of enterocyte brush-border ion transporter proteins (NHE2, NHE3, Aquaporin 7, Na/I symporter and H / K ATPase) showed reduced expression or mislocalisation in all THES patients with different profiles for each. In contrast the basolateral localisation of Na/K ATPase was not altered.
THES is caused by mutations in TTC37. TTC37 mutations have a multisystem effect which may be due to abnormal stability and / or intracellular localisation of TTC37 target proteins.
PMCID: PMC3166659  PMID: 20176027
phenotypic diarrhoea of infancy; platelet alpha granules; ion transporter proteins; thespin
6.  Differences in presentation and progression between severe FIC1 and BSEP deficiencies 
Journal of hepatology  2010;53(1):170-178.
Background & Aims
Progressive familial intrahepatic cholestasis (PFIC) with normal serum levels of gamma-glutamyltranspeptidase can result from mutations in ATP8B1 (encoding familial intrahepatic cholestasis 1 [FIC1]) or ABCB11 (encoding bile salt export pump [BSEP]). We evaluated clinical and laboratory features of disease in patients diagnosed with PFIC, who carried mutations in ATP8B1 (FIC1 deficiency) or ABCB11 (BSEP deficiency). Our goal was to identify features that distinguish presentation and course of these 2 disorders, thus facilitating diagnosis and elucidating the differing consequences of ATP8B1 and ABCB11 mutations.
A retrospective multi-center study was conducted, using questionnaires and chart review. Available clinical and biochemical data from 145 PFIC patients with mutations in either ATP8B1 (61 “FIC1 patients”) or ABCB11 (84 “BSEP patients”) were evaluated.
At presentation, serum aminotransferase and bile salt levels were higher in BSEP patients; serum alkaline phosphatase values were higher, and serum albumin values were lower, in FIC1 patients. Elevated white blood cell counts, and giant or multinucleate cells at liver biopsy, were more common in BSEP patients. BSEP patients more often had gallstones and portal hypertension. Diarrhea, pancreatic disease, rickets, pneumonia, abnormal sweat tests, hearing impairment, and poor growth were more common in FIC1 patients. Among BSEP patients, the course of disease was less rapidly progressive in patients bearing the D482G mutation.
Severe forms of FIC1 and BSEP deficiency differed. BSEP patients manifested more severe hepatobiliary disease, while FIC1 patients showed greater evidence of extrahepatic disease.
PMCID: PMC3042805  PMID: 20447715
cholestasis; genetics; transport protein; pediatrics; P-type ATPase; ATP binding cassette protein; ATP8B1; FIC1; ABCB11; BSEP
8.  Using a Shared Governance Structure to Evaluate the Implementation of a New Model of Care: The Shared Experience of a Performance Improvement Committee 
Sustaining change in the behaviors and habits of experienced practicing nurses can be frustrating and daunting, even when changes are based on evidence. Partnering with an active shared governance structure to communicate change and elicit feedback is an established method to foster partnership, equity, accountability and ownership. Few recent exemplars in the literature link shared governance, change management and evidence-based practice to transitions in care models. This article describes an innovative staff-driven approach used by nurses in a shared governance performance improvement committee to use evidence based practice in determining the best methods to evaluate the implementation of a new model of care.
PMCID: PMC4190061  PMID: 24061583
Gastroenterology  2013;144(5):945-e15.
The final step in bile acid synthesis involves conjugation with glycine and taurine, which promotes a high intraluminal micellar concentration to facilitate lipid absorption. We investigated the clinical, biochemical, molecular, and morphologic features of a genetic defect in bile acid conjugation in 10 pediatric patients with fat-soluble vitamin deficiency, some with growth failure or transient neonatal cholestatic hepatitis.
We identified the genetic defect that causes this disorder using mass spectrometry analysis of urine, bile, and serum samples, and sequence analysis of the genes encoding bile acid-CoA:amino acid N-acyltransferase (BAAT) and bile acid-Co A ligase (SLC27A5).
Levels of urinary bile acids were increased (432±248 μmol/L) and predominantly excreted in unconjugated forms (79.4%±3.9%), and as sulfates and glucuronides. Glycine or taurine conjugates were absent in the urine, bile and serum. Unconjugated bile acids accounted for 95.7%±5.8% of the bile acids in duodenal bile, with cholic acid accounting for 82.4%±5.5% of total. Duodenal bile acid concentrations were 12.1±5.9 mmol/L—a concentration too low for efficient lipid absorption. The biochemical profile was consistent with defective bile acid amidation. Molecular analysis of BAAT confirmed 4 different homozygous mutations in 8 patients tested.
Based on a study of 10 pediatric patients, genetic defects that disrupt bile acid amidation cause fat-soluble vitamin deficiency and growth failure, indicating the importance of bile acid conjugation in lipid absorption. Some patients developed liver disease with features of a cholangiopathy. These findings indicate that patients with idiopathic neonatal cholestasis or later onset of unexplained fat-soluble vitamin deficiency should be screened for defects in bile acid conjugation.
PMCID: PMC4175397  PMID: 23415802
Chronic Liver Disease; Hepatic; Inherited; Nutrient; Bile acid conjugation; Bile acid-CoA amino acid N-acyltransferase; BAAT; Glycine; Taurine; Mass Spectrometry; Cholestasis; Fat-soluble vitamin deficiency
10.  Role of stereotactic radiosurgery in patients with more than four brain metastases 
CNS oncology  2013;2(2):10.2217/cns.13.4.
For patients presenting with brain metastases, two methods of radiation treatment currently exist: stereotactic radiosurgery (SRS) and whole-brain radiation therapy (WBRT). SRS is a minimally invasive to noninvasive technique that delivers a high dose of ionizing radiation to a precisely defined focal target volume, whereas WBRT involves multiple smaller doses of radiation delivered to the whole brain. Evidence exists from randomized controlled trials for SRS in the treatment of patients with one to four brain metastases. Patients with more than four brain metastases generally receive WBRT, which can effectively treat undetected metastases and protect against intracranial relapse. However, WBRT has been associated with an increased potential for toxic neurocognitive side effects, including memory loss and early dementia, and does not provide 100% protection against relapse. For this reason, physicians at many medical centers are opting to use SRS as first-line treatment for patients with more than four brain metastases, despite evidence showing an increased rate of intracranial relapse compared with WBRT. In light of the evolving use of SRS, this review will examine the available reports on institutional trials and outcomes for patients with more than four brain metastases treated with SRS alone as first-line therapy.
PMCID: PMC3835313  PMID: 24273642
11.  CCBE1 Mutation in Two Siblings, One Manifesting Lymphedema-Cholestasis Syndrome, and the Other, Fetal Hydrops 
PLoS ONE  2013;8(9):e75770.
Lymphedema-cholestasis syndrome (LCS; Aagenaes syndrome) is a rare autosomal recessive disorder, characterized by 1) neonatal intrahepatic cholestasis, often lessening and becoming intermittent with age, and 2) severe chronic lymphedema, mainly lower limb. LCS was originally described in a Norwegian kindred in which a locus, LCS1, was mapped to a 6.6cM region on chromosome 15. Mutations in CCBE1 on chromosome 18 have been reported in some cases of lymphatic dysplasia, but not in LCS.
Consanguineous parents of Mexican ancestry had a child with LCS who did not exhibit extended homozygosity in the LCS1 region. A subsequent pregnancy was electively terminated due to fetal hydrops. We performed whole-genome single nucleotide polymorphism genotyping to identify regions of homozygosity in these siblings, and sequenced promising candidate genes.
Both siblings harbored a homozygous mutation in CCBE1, c.398 T>C, predicted to result in the missense change p.L133P. Regions containing known ‘cholestasis genes’ did not demonstrate homozygosity in the LCS patient.
Mutations in CCBE1 may yield a phenotype not only of lymphatic dysplasia, but also of LCS or fetal hydrops; however, the possibility that the sibling with LCS also carries a homozygous mutation in an unidentified gene influencing cholestasis cannot be excluded.
PMCID: PMC3784396  PMID: 24086631
12.  Primary Biliary Cirrhosis-Specific Antimitochondrial Antibodies in Neonatal Haemochromatosis 
Background and Aim. Neonatal hemochromatosis (NH) is characterised by severe liver injury and extrahepatic siderosis sparing the reticuloendothelial system. Its aetiology is obscure, although it has been proposed as an alloimmune disease, resulting from immunological reaction to self-antigens (alloantigens) which the body recognizes as foreign. We studied an infant with NH and his mother whose sera contained antimitochondrial antibody (AMA), the hallmark of primary biliary cirrhosis (PBC). Material and Methods. To investigate the origin of AMA in the infant, we studied isotype distributions in serum from the mother and infant. Serum samples were obtained at diagnosis of NH, after liver transplantation (LT; age 1 month), and over the ensuing 17 months. Results. At NH diagnosis, infant and maternal serum contained AMA of the IgG isotype, predominantly of the G3 and G1 subclasses. AMA strongly reacted against the pyruvate dehydrogenase complex E2 subunit (PDC-E2), the major PBC-specific AMA autoantigen. Anti-PDC-E2 responses in both infant and mother declined over time, being present 2 months after LT (mother and child) and absent 10 months later (mother) and 17 months later (child). Conclusion. The association of maternally transferred IgG1 and IgG3 subclass AMA with the appearance of liver damage in an infant with NH may suggest a causal link between antibody and liver damage.
PMCID: PMC3792542  PMID: 24171034
13.  Handheld Micromanipulator for Robot-Assisted Stapes Footplate Surgery 
Stapes footplate surgery is complex and delicate. This surgery is carried out in the middle ear to improve hearing. High accuracy is required to avoid critical tissues and structures near the surgical worksite. By suppressing the surgeon’s tremor during the operation, accuracy can be improved. In this paper, a fully handheld active micromanipulator known as Micron is evaluated for its feasibility for this delicate operation. An ergonomic handle, a custom tip, and a brace attachment were designed for stapes footplate surgery and tested in a fenestration task through a fixed speculum. Accuracy was measured during simulated surgery in two different scenarios: Micron off (unaided) and Micron on (aided), both with image guidance. Preliminary results show that Micron significantly reduces the mean position error and the mean duration of time spent in specified dangerous zones.
PMCID: PMC3561930  PMID: 23366167
14.  Is a Half-Truth a Whole Lie? 
Journal of Oncology Practice  2012;9(1):63-64.
PMCID: PMC3545666  PMID: 23633974
15.  The Effect of Tumor Subtype on Survival and the Graded Prognostic Assessment (GPA) for Patients with Breast Cancer and Brain Metastases 
The diagnosis-specific Graded Prognostic Assessment (GPA) was published to clarify prognosis for patients with brain metastases. This study refines the existing Breast-GPA by analyzing a larger cohort and tumor subtype.
A multi-institutional retrospective database of 400 breast cancer patients treated for newly-diagnosed brain metastases was generated. Prognostic factors significant for survival were analyzed by multivariate Cox regression (MCR) and recursive partitioning analysis (RPA). Factors were weighted by the magnitude of their regression coefficients to define the GPA index.
Significant prognostic factors by MCR and RPA were Karnofsky Performance Status (KPS), HER2, ER/PR status, and the interaction between ER/PR and HER2. RPA showed age was significant for patients with KPS 60–80. The median survival time (MST) overall was 13.8 months, and for GPA scores of 0–1.0, 1.5–2.0, 2.5–3.0 and 3.5–4.0 was 3.4 (n=23), 7.7 (n=104), 15.1 (n=140) and 25.3 (n=133) months, respectively (p < 0.0001). Among HER2-negative patients, being ER/PR-positive improved MST from 6.4 to 9.7 months whereas in HER2-positive patients, being ER/PR-positive improved MST from 17.9 to 20.7 months. The log-rank statistic (predictive power) was 110 for the Breast-GPA versus 55 for tumor subtype.
The Breast-GPA documents wide variation in prognosis and shows clear separation between subgroups of patients with breast cancer and brain metastases. This tool will aid clinical decision-making and stratification of clinical trials. These data confirm the effect of tumor subtype on survival and show the Breast-GPA offers significantly more predictive power than the tumor subtype alone.
PMCID: PMC3172400  PMID: 21497451
breast cancer; brain metastases; prognosis; radiation therapy; stereotactic radiosurgery; estrogen; progesterone; HER2; outcomes
16.  Mutation detection in cholestatic patients using microarray resequencing of ATP8B1 and ABCB11  
F1000Research  2013;2:32.
Background : Neonatal cholestasis is a common presentation of childhood liver diseases and can be a feature of various conditions including disorders of bile acid biogenesis and transport, various inborn errors of metabolism and perinatal infections. Some inherited metabolic diseases can be easily screened using biochemical assays, however many can only be accurately diagnosed by DNA sequencing. Fluorescent capillary Sanger sequencing (FS) is the gold standard method used by clinical laboratories for genetic diagnosis of many inherited conditions; however, it does have limitations. Recently microarray resequencing (MR) has been introduced into research and clinical practice as an alternative method for genetic diagnosis of heterogeneous conditions. In this report we compared the accuracy of mutation detection for MR with FS in a group of patients with ‘low-normal’ gamma glutamyl transpeptidase (gGT) cholestasis without known molecular diagnoses.
Methods : 29 patient DNA samples were tested for mutations in the ATP8B1 and ABCB11 genes using both FS and MR. Other known causes of “low gGT cholestasis” such as ARC syndrome and bile acid biosynthesis disorders were excluded.
Results : Mutations were identified in 13/29 samples. In 3/29 samples FS and MR gave discordant results: MR had a false positive rate of 3.4% and a false negative rate of 7%.
Conclusions : The major advantage of MR over FS is that multiple genes can be screened in one experiment, allowing rapid and cost-effective diagnoses.  However, we have demonstrated that MR technology is limited in sensitivity. We therefore recommend that MR be used as an initial evaluation, with FS deployed when genetic and clinical or histopathological findings are discordant.
PMCID: PMC3907151  PMID: 24627769
17.  Mutation detection in cholestatic patients using microarray resequencing of ATP8B1 and ABCB11  
F1000Research  2013;2:32.
Background : Neonatal cholestasis is a common presentation of childhood liver diseases and can be a feature of various conditions including disorders of bile acid biogenesis and transport, various inborn errors of metabolism and perinatal infections. Some inherited metabolic diseases can be easily screened using biochemical assays, however many can only be accurately diagnosed by DNA sequencing. Fluorescent capillary Sanger sequencing (FS) is the gold standard method used by clinical laboratories for genetic diagnosis of many inherited conditions; however, it does have limitations. Recently microarray resequencing (MR) has been introduced into research and clinical practice as an alternative method for genetic diagnosis of heterogeneous conditions. In this report we compared the accuracy of mutation detection for MR with FS in a group of patients with ‘low-normal’ gamma glutamyl transpeptidase (gGT) cholestasis without known molecular diagnoses.
Methods : 29 patient DNA samples were tested for mutations in the ATP8B1 and ABCB11 genes using both FS and MR. Other known causes of “low gGT cholestasis” such as ARC syndrome and bile acid biosynthesis disorders were excluded.
Results : Mutations were identified in 13/29 samples. In 3/29 samples FS and MR gave discordant results: MR had a false positive rate of 3.4% and a false negative rate of 7%.
Conclusions : The major advantage of MR over FS is that multiple genes can be screened in one experiment, allowing rapid and cost-effective diagnoses.  However, we have demonstrated that MR technology is limited in sensitivity. We therefore recommend that MR be used as an initial evaluation, with FS deployed when genetic and clinical or histopathological findings are discordant.
PMCID: PMC3907151  PMID: 24627769
18.  Summary Report on the Graded Prognostic Assessment: An Accurate and Facile Diagnosis-Specific Tool to Estimate Survival for Patients With Brain Metastases 
Journal of Clinical Oncology  2011;30(4):419-425.
Our group has previously published the Graded Prognostic Assessment (GPA), a prognostic index for patients with brain metastases. Updates have been published with refinements to create diagnosis-specific Graded Prognostic Assessment indices. The purpose of this report is to present the updated diagnosis-specific GPA indices in a single, unified, user-friendly report to allow ease of access and use by treating physicians.
A multi-institutional retrospective (1985 to 2007) database of 3,940 patients with newly diagnosed brain metastases underwent univariate and multivariate analyses of prognostic factors associated with outcomes by primary site and treatment. Significant prognostic factors were used to define the diagnosis-specific GPA prognostic indices. A GPA of 4.0 correlates with the best prognosis, whereas a GPA of 0.0 corresponds with the worst prognosis.
Significant prognostic factors varied by diagnosis. For lung cancer, prognostic factors were Karnofsky performance score, age, presence of extracranial metastases, and number of brain metastases, confirming the original Lung-GPA. For melanoma and renal cell cancer, prognostic factors were Karnofsky performance score and the number of brain metastases. For breast cancer, prognostic factors were tumor subtype, Karnofsky performance score, and age. For GI cancer, the only prognostic factor was the Karnofsky performance score. The median survival times by GPA score and diagnosis were determined.
Prognostic factors for patients with brain metastases vary by diagnosis, and for each diagnosis, a robust separation into different GPA scores was discerned, implying considerable heterogeneity in outcome, even within a single tumor type. In summary, these indices and related worksheet provide an accurate and facile diagnosis-specific tool to estimate survival, potentially select appropriate treatment, and stratify clinical trials for patients with brain metastases.
PMCID: PMC3269967  PMID: 22203767
19.  An Integrated Approach to Segmentation and Nonrigid Registration for Application in Image-Guided Pelvic Radiotherapy 
Medical image analysis  2011;15(5):772-785.
External beam radiotherapy (EBRT) has become the preferred options for non-surgical treatment of prostate cancer and cervix cancer. In order to deliver higher doses to cancerous regions within these pelvic structures (i.e. prostate or cervix) while maintaining or lowering the doses to surrounding non-cancerous regions, it is critical to account for setup variation, organ motion, anatomical changes due to treatment and intra-fraction motion. In previous work, manual segmentation of the soft tissues is performed and then images are registered based on the manual segmentation. In this paper, we present an integrated automatic approach to multiple organ segmentation and nonrigid constrained registration, which can achieve these two aims simultaneously. The segmentation and registration steps are both formulated using a Bayesian framework, and they constrain each other using an iterative conditional model strategy. We also propose a new strategy to assess cumulative actual dose for this novel integrated algorithm, in order to both determine whether the intended treatment is being delivered and, potentially, whether or not a plan should be adjusted for future treatment fractions. Quantitative results show that the automatic segmentation produced results that have an accuracy comparable to manual segmentation, while the registration part significantly outperforms both rigid and non-rigid registration. Clinical application and evaluation of dose delivery show the superiority of proposed method to the procedure currently used in clinical practice, i.e. manual segmentation followed by rigid registration.
PMCID: PMC3164526  PMID: 21646038
Image segmentation; Non-rigid registration; Image guided radiotherapy; Prostate cancer; Cervical cancer; Dose delivery
20.  Diagnosis in bile acid-CoA: Amino acid N-acyltransferase deficiency 
Cholate-CoA ligase (CCL) and bile acid-CoA: amino acid N-acyltransferase (BAAT) sequentially mediate bile-acid amidation. Defects can cause intrahepatic cholestasis. Distinction has required gene sequencing. We assessed potential clinical utility of immunostaining of liver for CCL and BAAT. Using commercially available antibodies against BAAT and CCL, we immunostained liver from an infant with jaundice, deficiency of amidated bile acids, and transcription-terminating mutation in BAAT. CCL was normally expressed. BAAT expression was not detected. Immunostaining may facilitate diagnosis in bile-acid amidation defects.
PMCID: PMC3391772  PMID: 22783059
Amidation; Bile acid-CoA; Amino acid N-acyltransferase; Cholate-CoA ligase; Cholestasis; Conjugation; Electrospray ionisation-mass spectroscopy; Immunohistochemistry; Liver; Neonatal hepatitis; SLC27A5; Transmission electron microscopy
21.  Melanoma Brain Metastases: Is it Time to Reassess the Bias? 
Current problems in cancer  2011;35(4):200-210.
Melanoma patients with brain metastases are typically excluded from clinical trials due to historically dismal survival (<4 months) and concerns about blood brain barrier drug penetration. The pleural cavity is another location with potential decreased drug penetrance, yet malignant effusion patients are not excluded. Here we discuss whether new technologies for local control of brain metastases have altered survival patterns. We also report our findings from a retrospective chart review of 251 metastatic melanoma patients diagnosed after 2005, and evaluate our findings in the context of eligibility for clinical trials with novel agents. We found that median survival of malignant effusion patients was significantly shorter than brain metastasis patients (two versus eight months, p < 0.0001). Only one pleural effusion patient lived >9 months, whereas 41 (39.4%) brain metastasis patients survived beyond this time. We conclude that with the advent of effective means for providing local control for brain metastases, survival of these patients has improved, and they often succumb to extra-cranial disease. Exclusion of melanoma brain metastasis patients from clinical research programs is no longer justified and alternative investigational approaches, possibly combining local and systemic therapies, are urgently needed for these individuals.
PMCID: PMC3173717  PMID: 21911183
melanoma; brain metastases; prognosis; clinical trial design
22.  Implications of Identifying Additional Cerebral Metastases during Gamma Knife Radiosurgery 
Introduction. Gamma Knife radiosurgery (GK-SRS) is commonly used to treat cerebral metastases. Although additional intracranial metastases are often found on the day of GK-SRS, the significance of finding them is unknown. Methods. A retrospective review of 133 patients undergoing GK-SRS for cerebral metastases was performed. The change in number of metastases detected between initial referral magnetic resonance imaging (MRI) and subsequent treatment MRI was quantified. Multivariate and Kaplan-Meier analyses were employed to examine the significance of identifying additional lesions. Results. Additional lesions were identified in 41% of patients. An increasing number of metastases on referral MRI (P = 0.001) and the presence of progressive systemic disease (P = 0.003) were predictive of identifying additional metastases. Median survival was 6.9 months for patients with additional metastases, compared to 12.1 months for patients without additional metastases (hazard ratio 1.56, P = 0.021). Conclusions. Identifying additional metastases on the day of GK-SRS may add important prognostic information.
PMCID: PMC3265271  PMID: 22312543
23.  Constrained non-rigid registration for use in image-guided adaptive radiotherapy 
Medical image analysis  2009;13(5):809-817.
A constrained non-rigid registration (CNRR) algorithm for use in prostate image-guided adaptive radiotherapy is presented in a coherent mathematical framework. The registration algorithm is based on a global rigid transformation combined with a series of local injective non-rigid multi-resolution cubic B-spline Free Form Deformation (FFD) transformations. The control points of the FFD are used to non-rigidly constrain the transformation to the prostate, rectum, and bladder. As well, the control points are used to rigidly constrain the transformation to the estimated position of the pelvis, left femur, and right femur. The algorithm was tested with both 3D conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT) dose plan data sets. The 3DCRT dose plan set consisted of 10 fan-beam CT (FBCT) treatment-day images acquired from four different patients. The IMRT dose plan set consisted of 32 cone-beam CT (CBCT) treatment-day images acquired from 4 different patients. The CNRR was tested with different combinations of anatomical constraints and each test significantly outperformed both rigid and non-rigid registration at aligning constrained bones and critical organs. The CNRR results were used to adapt the dose plans to account for patient positioning errors as well as inter-day bone motion and intrinsic organ deformation. Each adapted dose plan improved performance by lowering radiation distribution to the rectum and bladder while increasing or maintaining radiation distribution to the prostate.
PMCID: PMC2771756  PMID: 19682945
Non-rigid image registration; B-spline free form deformation; Rigid registration; Image-guided radiotherapy; Adaptive prostate radiotherapy
24.  Identification of Acidic Dileucine Signals in LRP9 that Interact with Both GGAs and AP-1/AP-2 
Traffic (Copenhagen, Denmark)  2008;9(9):1551-1562.
The GGA family of monomeric clathrin adaptors are known to bind to cargo molecules via short C-terminal peptide motifs conforming to the sequence DXXLL (X= any amino acid), while the heterotetrameric adaptors AP-1 and AP-2 utilize a similar but discrete sorting motif of the sequence [D,E]XXXL[L,I]. While it has been established that a single cargo molecule may contain either or both types of these acidic cluster-dileucine (AC-LL) sorting signals, there are no examples of cargo with overlapping GGA and AP-1/AP-2 binding motifs. Here we report that the cytosolic tail of LRP9 contains a bifunctional GGA and AP-1/AP-2 binding motif at its carboxy terminus (EDEPLL). We further demonstrate that the internal EDEVLL sequence of LRP9 also binds to GGAs in addition to AP-2. Either AC-LL motif of LRP9 is functional in endocytosis. These findings represent the first study characterizing the trafficking of LRP9 and also have implications for the identification of additional GGA cargo molecules.
PMCID: PMC2892795  PMID: 18627575
GGAs; AP-1; AP-2; dileucine motif; endocytosis; LRP9
25.  Psychopathology and treatment outcome of drug dependent women in a perinatal program 
Addictive behaviors  2004;29(4):731-741.
One hundred and five drug-dependent women in outpatient perinatal addiction treatment were classified by cluster analysis of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) profiles into high and low psychopathology (HP and LP) groups that differed on three validation measures. The HP group (n = 29, 27.6%) had elevations on MMPI-2 Scales F, 2, 4, 6, 7, and 8, while the LP group (n = 76, 72.4%) generated a normal range profile with elevations on Scales F and 4. Psychological outcomes differed by group. HP participants showed reduced alcohol, family, and psychiatric severity, and reduced depressive symptoms, while LP subjects showed reduced drug, self-debasing, and acting-out problems. Data suggest the need for lower intensity services for the majority of the perinatal drug dependent population with LP.
PMCID: PMC2868062  PMID: 15135555

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