P1536Does free thyroxine (fT4) predict risk of atherosclerotic cardiovascular disease (ASCVD)?

Background

Thyroid hormones are associated with arrhythmic risk, but their relationship to ASCVD is unclear. The Rotterdam Study* reported associations of higher fT4 and lower thyroid stimulating hormone (TSH) levels with ASCVD, including within the euthyroid range. Free T3 (fT3) was not assessed.

Methods

We tested whether fT4, fT3, and TSH levels were associated with ASCVD in Intermountain Healthcare. All patients >18 y old with an fT4 level in the electronic medical record database were included. The hormone reference ranges were divided into quartiles (Q), and associations with prevalent and incident ASCVD were assessed by multivariable regression and trend tests.

Results

A total of 212,202 patients (age = 64.4±11.2 y; 66.6% women) were included and followed for 6.1±4.4 y. Of these, 8.3%, 86.6%, and 5.1% had fT4 levels below, within, and above the reference range. CAD was prevalent in 18.9% of fT4 Q1 patients. The adjusted odds ratio (OR) for coronary artery disease (CAD) increased through (Q4/Q1 OR=1.36) and beyond (High/Q1 OR=1.71) the normal range, p-trend<0.001 (Table). Smaller incremental risks were noted for fT3 (Q4/Q1 OR=1.13; High/Q1 OR=1.25). The frequencies of incident MI (Q1=2.5%) and stroke (Q1=5.4%) were low and did not show a concentration-related risk gradient. Incident all-cause death (Q1=24.3%) increased slightly for Q4 and high fT4 (OR=1.05, 1.06) but not fT3; death also increased with low fT4 (OR=1.28). TSH showed no consistent gradient within the normal range for prevalent or incident events; however, mortality increased with both high and low TSH.

Thyroid Hormone Levels and Prevalent CAD Prevalent CAD (adjusted OR) Low Normal Q1 Normal Q2 Normal Q3 Normal Q4 High fT4 (n=212,202) OR=1.08, p=0.02 OR=1.00 referent OR=1.11, p<0.001 OR=1.21, p<0.001 OR=1.36, p<0.001 OR=1.71, p<0.001 fT3 (n=30,200) OR=1.12, p<0.001 OR=1.00 referent OR=0.98, p=0.61 OR=1.02, p=0.53 OR=1.13, p<0.001 OR=1.25, p<0.001 TSH (n=183,227) OR=1.39, p<0.001 OR=1.00 referent OR=0.93, p=0.42 OR=0.88, p=0.15 OR=0.92, p=0.35 OR=1.73, p<0.001 Reference Q 1–4 are: fT4: 0.75–0.90; 0.91–1.01; 2.02–1.14; 1.15–1.50 ng/dL; TSH: 0.54–1.30; 1.31–2.04; 2.05–3.68; 3.69–6.80 uIU/mL; fT3: 2.40–2.60; 2.70–2.80; 2.90–3.10; 3.20–4.20 pg/dL.

Conclusions

Consistent with the Rotterdam Study, we found an increase in prevalent CAD with increasing fT4 levels within and beyond the normal range and, uniquely, a more modest relationship with fT3. We could not confirm a normal-range relationship between hormone levels and incident events or between TSH and prevalent disease. The relationship of fT4 levels to ASCVD is intriguing, is deserving of further study, and may have important implications for ASCVD prevention.

*A Bano, et-al. Circ Res 2017; 121:1397–1400

Quantitative fluorescence using 5-aminolevulinic acid-induced protoporphyrin IX biomarker as a surgical adjunct in low-grade glioma surgery

OBJECT

Previous studies in high-grade gliomas (HGGs) have indicated that protoporphyrin IX (PpIX) accumulates in higher concentrations in tumor tissue, and, when used to guide surgery, it has enabled improved resection leading to increased progression-free survival. Despite the benefits of complete resection and the advances in fluorescence-guided surgery, few studies have investigated the use of PpIX in low-grade gliomas (LGGs). Here, the authors describe their initial experience with 5-aminolevulinic acid (ALA)-induced PpIX fluorescence in a series of patients with LGG.

METHODS

Twelve patients with presumed LGGs underwent resection of their tumors after receiving 20 mg/kg of ALA approximately 3 hours prior to surgery under an institutional review board-approved protocol. Intraoperative assessments of the resulting PpIX emissions using both qualitative, visible fluorescence and quantitative measurements of PpIX concentration were obtained from tissue locations that were subsequently biopsied and evaluated histopathologically. Mixed models for random effects and receiver operating characteristic curve analysis for diagnostic performance were performed on the fluorescence data relative to the gold-standard histopathology.

RESULTS

Five of the 12 LGGs (1 ganglioglioma, 1 oligoastrocytoma, 1 pleomorphic xanthoastrocytoma, 1 oligodendroglioma, and 1 ependymoma) demonstrated at least 1 instance of visible fluorescence during surgery. Visible fluorescence evaluated on a specimen-by-specimen basis yielded a diagnostic accuracy of 38.0% (cutoff threshold: visible fluorescence score ≥ 1, area under the curve = 0.514). Quantitative fluorescence yielded a diagnostic accuracy of 67% (for a cutoff threshold of the concentration of PpIX [CPpIX] > 0.0056 μg/ml, area under the curve = 0.66). The authors found that 45% (9/20) of nonvisibly fluorescent tumor specimens, which would have otherwise gone undetected, accumulated diagnostically significant levels of CPpIX that were detected quantitatively.

CONCLUSIONS

The authors' initial experience with ALA-induced PpIX fluorescence in LGGs concurs with other literature reports that the resulting visual fluorescence has poor diagnostic accuracy. However, the authors also found that diagnostically significant levels of CPpIX do accumulate in LGGs, and the resulting fluorescence emissions are very often below the detection threshold of current visual fluorescence imaging methods. Indeed, at least in the authors' initial experience reported here, if quantitative detection methods are deployed, the diagnostic performance of ALA-induced PpIX fluorescence in LGGs approaches the accuracy associated with visual fluorescence in HGGs.

False-negative MRI biomarkers of tumour response to targeted cancer therapeutics

BACKGROUND

Non-invasive quantitative imaging biomarkers are essential for the evaluation of novel targeted therapeutics. Before deployment in clinical trials, such imaging biomarkers require qualification, typically through pre-clinical identification of imaging-pathology correlates.

METHODS

First, in investigating imaging biomarkers of invasion, the response of orthotopic murine PC3 prostate xenografts to the Src inhibitor saracatinib was assessed using susceptibility contrast MRI. Second, the longitudinal response of chemically induced rat mammary adenocarcinomas to the VEGFR2 inhibitor vandetanib was monitored by intrinsic susceptibility MRI, to identify the time window of transient vascular normalisation.

RESULTS

No significant differences in fractional blood volume (%), vessel calibre (μm), native T(1) (ms) or apparent water diffusion coefficient were determined, despite reduced expression of activated Fak and paxillin in the saracatinib cohort. Treatment with vandetanib elicited a 60% antitumour response (P<0.01), 80% inhibition in vessel density (P<0.05) and reduction in hypoxia (P<0.05). There was, however, no significant change in tumour baseline R(2)* (s(-1)) or carbogen-induced ΔR(2)* with treatment.

CONCLUSION

Reporting negative imaging biomarker responses is important, to avoid the risk of clinical trials using the same biomarkers being undertaken with a false expectation of success, and the abandonment of promising new therapeutics based on a false-negative imaging biomarker response being mistaken for a true-negative.

Src inhibitors in early breast cancer: a methodology, feasibility and variability study

Early clinical trials of anticancer agents may be enriched by robust biomarkers of activity. Surrogate measures used in trials of cytotoxic agents, such as tumor size regression, may not be informative when investigating targeted agents that act principally to inhibit invasion or proliferation. This study aimed to determine the validity of invasion-related biomarkers of activity for AZD0530, a potent Src inhibitor currently in clinical development. Focal adhesion kinase (FAK) and paxillin are downstream phosphorylation substrates of Src and mediate tumor cell adhesion and invasiveness. These were therefore selected as biologically relevant markers of Src inhibition. Early breast cancer was chosen as a model as multiple samples can be collected during standard treatment and there is an intervening period in which experimental intervention can be applied. Tumor tissue was collected from diagnostic core biopsies and subsequent surgical tumor excision samples in 29 women with early breast cancer attending a single center. Protein levels were assessed quantitatively by Luminex and qualitatively by immunohistochemistry. AZD0530 inhibited tumor growth in a manner independent of dose and inhibited phosphorylation of FAK and paxillin in a dose-dependent manner in a Calu-6 xenograft model. In the clinical study, agreement of within-visit and also of between-visit measurements was high and the estimated number of patients required to detect a drug effect would be low enough to allow use of these markers as endpoints in future dose selection studies.

Src kinase activity in early breast cancer (EBC): A quantitative luminometric and immunohistochemical (IHC) approach

13010

Background: Src kinase expression and activity is increased in many solid tumors including breast cancer, and Src kinase has a role in the regulation of cancer cell invasion. Thus, Src kinase is a potential therapeutic target. Targeting cancer cell invasion may be of particular value in early disease, although drug effects are unlikely to be measurable by conventional endpoints, for example tumor regression. This prospective study aimed to establish robust measures of Src activity in invasion-related pathways in tissue derived from EBC and to assess the variability between these measures, in order to establish a methodology for pharmacodynamic assessment of Src inhibition in clinical disease. Methods: Duplicate sets of core biopsies were taken from 30 patients, both at diagnosis and surgery. Biopsies were fixed immediately in either liquid nitrogen (luminometric analysis) or pre-cooled isopentane (IHC analysis). Formalin-fixed, paraffin-embedded tissue (FFPET) was also collected at the time of diagnosis. Levels of phospho-paxillin, phospho-focal adhesion kinase (FAK), total phosphotyrosine and total paxillin were measured in lysed tumor tissue using the Luminex system. Expression of activated Src, phospho-paxillin, phospho-FAK, total paxillin and total FAK was determined in sections of frozen tissue and FFPET, and assessed semi-quantitatively by visual examination. An analysis of variance (ANOVA) model was fitted to the Luminex data ( Table ). Results: All tumors expressed active Src, and there was a high level of expression, but low variability, of paxillin, FAK, phospho-paxillin and phospho-FAK. The subcellular localization of these markers could also be assessed in FFPET sections. Conclusion: The results indicate the feasibility of assessing the effect of a Src inhibitor on invasion-related endpoints in women awaiting surgery for EBC.

[Table: see text]

[Table: see text]

Umbilical Cord Stromal Cells (UCSC)

The identification of appropriate cell types is necessary to establish cell-based therapies in regenerative medicine. These cell types must (1) be available in an appropriate amount, (2) be easy to obtain, (3) be sufficiently expandable in vitro, and (4) fit to or at least be able to differentiate into the required cell type. Since the umbilical cord is available without any intervention and represents a notable amount of tissue, we consider it to be a promising source for isolating cells for cell-based therapies. This study demonstrates that umbilical cord stromal cells (UCSC), the connective tissue cells of the umbilical cord, can be isolated in sufficient quantities and be well expanded. UCSC feature phenotypic plasticity and thus are functionally similar to stem cells. UCSC can be differentiated into cells with osteoblastic properties (expression of alkaline phosphatase, formation of bone nodules). It is concluded that the umbilical cord should no longer be regarded as valueless tissue and be unthinkingly discarded. Instead, it should be considered a valuable resource for the isolation of potent cells for cell-based therapies, especially for treatment of bone defects.

Laparoscopic management of 641 adnexal tumors in Kiel, Germany

STUDY OBJECTIVE

To evaluate the effectiveness and safety of laparoscopic and laparotomic management of ovarian tumors.

DESIGN

Retrospective analysis (Canadian Task Force classification II-2).

SETTING

University-affiliated hospital.

PATIENTS

Six hundred forty-one women with benign and malignant ovarian tumors.

INTERVENTIONS

Laparoscopy and laparotomy.

MEASUREMENTS AND MAIN RESULTS

Between January 1997 and December 1998, 493 (76.9%) ovarian tumors were treated laparoscopically and 138 (21.5%) by laparotomy. Criteria for laparotomy were high suspicion of malignancy and tumors larger than 10 cm that were technically too difficult for the laparoscopic approach. The mean size of tumors treated laparoscopically was 4.5 cm (range 1.1-11 cm) and by laparotomy 8.2 cm (range 3-20 cm). Mean operating times were 75.7 minutes (range 30-200 min) and 126 minutes (range 30-235 min), respectively, and mean blood loss was 193 ml (range 50-1200 ml) and 431 ml (range 50-2500 ml), respectively. Twelve laparoscopies were converted to laparotomy, six because of technical reasons such as severe adhesions, bleeding, or tumor size, and six for intraoperative suspicion of malignancy. Of the latter, four (66.7%) turned out to be ovarian carcinoma and two (33.3%) borderline tumors. Histologic evaluation clearly revealed predominance of functional ovarian cysts, endometriomas, and dermoid cysts in the group treated by laparoscopy, whereas ovarian carcinomas, large endometriomas, and serous cysts prevailed in the laparotomy group.

CONCLUSION

With careful preoperative screening, the rate of laparoscopies for treatment of benign ovarian cysts can be increased. (J Am Assoc Gynecol Laparosc 8(1):74-82, 2001)

Informational needs of surgical patients following discharge

A decreased length of hospital stay for surgical patients dramatically reduces the time available for nurses to teach patients how to manage postdischarge self-care. Nurses need guidelines to prioritize teaching content. This study explored the perceptions of information needed by 45 patients who were recently discharged following short-term surgical procedures. Patients identified information related to activity, wound care, complications, and pain management as highly important. Patient reports of information given and satisfaction with information were also examined. These findings can contribute to the development of teaching programs for patients who are discharged following short-term surgical procedures.

Glucuronidation associated with intrinsic resistance to mycophenolic acid in human colorectal carcinoma cells

The in vivo efficacy of the antitumor, immunosuppressive antibiotic mycophenolic acid is known to be limited by its rapid conversion to the biologically inactive 7-0-glucuronide, catalyzed by UDP-glucuronosyl transferase activity, which is widely distributed among normal tissues, including intestinal epithelium. We have found that mycophenolic acid is also converted to its glucuronide by several lines of human colorectal carcinoma cells, including HT29, Lovo, and Colo-205. In contrast, malignant cell lines not of colorectal origin, including EMT6, HeLa, and SKOV3, showed no ability to metabolize mycophenolic acid. The 7-amino derivative of mycophenolic acid was not metabolized by HT29 cells. This compound was less potent than mycophenolic acid versus EMT6 and HeLa cells but showed inhibitory activity against HT29 cells comparable with the parent antibiotic. The rapid metabolism of mycophenolic acid by HT29 cells was associated with a markedly lower sensitivity to both the antiproliferative activity of the drug and to its ability to inhibit GTP synthesis, compared with cells lacking the capacity for significant glucuronidation. After an initial decline in cellular GTP in HT29 cells induced by mycophenolic acid, there was a progressive recovery in GTP over 48 h, accompanying the metabolism of the antibiotic. This recovery process was not observed in EMT6 cells. It is suggested that glucuronosyl transferase activity may occur widely in colorectal cancer cells and could contribute to resistance to drugs that are susceptible to inactivation by glucuronide conjugation.

Glucuronidation by human colorectal adenocarcinoma cells as a mechanism of resistance to mycophenolic acid

Mycophenolic acid (MPA), a potent and specific inhibitor of IMP dehydrogenase, exerts its anti-mitotic action by a rapid depletion of the cellular content of guanine nucleotides. Although MPA is a potent inhibitor of GTP synthesis in the HT29 line of human colorectal adenocarcinoma cells in short-term culture, its ability to depress the cloning efficiency of these cells was found to be markedly less than against the mouse mammary carcinoma line, EMT6. In vivo, MPA is efficiently converted to the biologically inactive O-glucuronide derivative thereby limiting its effectiveness as an anti-tumor agent. Investigation of the fate of MPA incubated with monolayer cultures of HT29 and EMT6 cells revealed that the compound is rapidly converted to the O-glucuronide derivative by HT29 cells, but not by EMT6 cells. Confirmation of the identity of the glucuronide formed by HT29 cells was obtained by its conversion to MPA after incubation with beta-glucuronidase and by comparison of the mass spectrum of its HPLC peak with that of synthetic MPA O-glucuronide. Cultures of two other lines of human colorectal adenocarcinoma cells, Colo-205 and LoVo, also depleted their culture media of MPA although we have not yet established whether these cells also synthesize the glucuronide. The intrinsic partial resistance of HT29 cells to MPA appears to be associated with the ability of these cells to convert MPA to the biologically inactive glucuronide. These results, in conjunction with other reports of the capacity of colorectal cancer cells for Phase I and II metabolism of xenobiotics, may have implications for the design of drugs intended for the treatment of colorectal cancer.

T-lymphoid extramedullary (lymphadenopathic) blast crisis in CML

T-cells are only rarely involved in chronic myeloid leukemia. We report an unusual case of T-lymphoid extramedullary (lymphadenopathic) blast crisis in a 66-year-old patient with Philadelphia positive chronic myeloid leukemia. The lymph node morphological picture resembled that of a peripheral T-cell lymphoma. Immunohistochemical stainings showed most lymph node blasts to have T-phenotype (positivity for CD-2, CD-3 and CD-5). Flow cytometric phenotyping confirmed T-phenotype, with positivity for CD-7, CD-38 and TdT. Cytogenetic analysis of lymph node cells revealed Philadelphia chromosome with an additional chromosomal abnormality (add(6p)). The BCR-gene rearrangement in the lymph node blasts was identical to that in the bone marrow. This case adds to the growing evidence that CML may be a disorder of the common stem cell from which T-, B- and myeloid progenitors originate.

Depressed phagocytosis in hemodialyzed patients: in vivo and in vitro mechanisms

Infection is a frequent complication and the major cause of death among end-stage renal patients. Polymorphonuclear phagocytes (PMNL) are important in host defense mainly because of bacterial destruction by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-related free radical production following phagocytosis. In this study, hexose monophosphate pathway glycolytic activity, delivering energy to NADPH oxidase, is evaluated in vivo and in vitro, in healthy controls and in dialyzed renal failure patients. Our results show a marked parallel and correlated inhibition in the response to three stimuli for phagocytic activity (Staphylococcus aureus, formyl-methionine-leucine-phenylalanine, phorbol myristic acid) in predialysis samples. These data point to a main suppression of metabolic pathways, possibly beyond protein kinase C. This response is further suppressed at the 15th minute of cuprophane dialysis, for all stimuli studied (-40 to -94%; p < 0.001) except PMA. PMNL response remains intact during dialysis with non-complement-activating dialyzers. In vitro experiments confirm decreased PMNL glycolytic activity after the suspension of cuprophane fragments in normal whole blood. We conclude that polymorphonuclear cell energy delivery to NADPH oxidase is impaired in patients with end-stage renal failure. The impaired response against various stimuli is different in predialysis blood samples compared to samples collected during cuprophane dialysis, and may be related to two different conditions. These events probably contribute to the acquired immune suppression of uremia and the high incidence of infection among dialysis patients.

Radiographic assessment of liver volume in dogs

In a group of 65 dogs, radiographic liver length, the length of the axis from the most cranial part of the diaphragm to the apex of the liver tip, was correlated significantly (P less than 0.000001) with real liver volume. Within this group, radiographic liver length, compared with the length of the eleventh thoracic vertebra, was correlated with liver volume per kilogram of body weight. In a group of 30 dogs, with histologically normal liver, this measurement was not affected by thoracic conformation. These findings suggest that radiographic liver length is a reliable measurement for estimating liver volume in dogs and that it is not influenced by thoracic conformation. For 60 of the 65 dogs, a method of assessment of liver volume was formulated that required 2 measurements to be made on the lateral abdominal radiograph and 1 to be made on the dog itself.

Chorioamnionitis: how useful is the determination of C-reactive protein?

This study was designed to derive the predictive value of C-reactive protein (CRP) in peripheral venous serum of patients admitted to hospital with suspected premature rupture of the membranes (PROM). CRP was assayed by each of 4 separate methods and the results have been compared for accuracy and practical value with respect to clinical outcome and the histopathology of the placenta. Of the 4 techniques used only the latex test had characteristics suitable for a diagnostic screen. While the results were only semiquantitative, when comparisons were made to other techniques no significant change in clinical diagnosis would have been made. The results have confirmed that chorioamnionitis and preterm labour are often associated, but in some instances the extent of inflammatory infiltration was greater than might have been expected from the short time interval between documented membrane rupture and delivery. Thus it may be speculated that some cases of PROM are secondary to, rather than causative of, infection. Finally it is suggested that a controlled therapeutic trial of active intervention in those cases of PROM with elevated CRP in the absence of other clinical parameters suggestive of intrauterine infection should be undertaken.