Prospective investigation of amino acid transport and PSMA-targeted positron emission tomography for metastatic lobular breast carcinoma.

PURPOSE: To explore the feasibility of imaging amino-acid transport and PSMA molecular pathways in the detection of metastatic breast invasive lobular carcinoma (ILC) and if there is superior detection compared to standard-of-care imaging [computed tomography (CT)/bone scan, or 18F-FDG positron-emission-tomography (PET)-CT]. METHODS: 20 women with de-novo or suspected metastatic ILC underwent two PET-CT scans with 18F-fluciclovine and 68Ga-PSMA-11 on separate days. Uptake per patient and in 3 regions per patient - ipsilateral axillary lymph node (LN), extra-axillary LN (ipsilateral supraclavicular or internal mammary), or distant sites of disease - was compared to standard-of-care imaging (CT/bone scan in 13 patients and 18F-FDG PET-CT in 7 patients). Results were correlated to a composite standard of truth. Confirmed detection rate (cDR) was compared using McNemar's test. Mean SUVmax of 18F-fluciclovine and 68Ga-PSMA-11 in the most avid lesion for each true positive metastatic region and intact primary lesion were compared by t-test. RESULTS: The cDR for standard-of-care imaging was 5/20 patients in 5/60 regions. 68Ga-PSMA-11 PET-CT detected metastasis in 7/20 patients in 7/60 regions. 18F-fluciclovine PET-CT detected metastasis in 9/20 patients in 12/60 regions. The cDR for 18F-fluciclovine PET-CT was significantly higher versus standard-of-care imaging on the patient and combined region levels, while there were no significant differences between 68Ga-PSMA-11 and standard-of care imaging. 18F-fluciclovine cDR was also significantly higher than 68Ga-PSMA-11 on the combined region level. Mean SUVmax for true positive metastatic and primary lesions with 18F-fluciclovine (n = 18) was significantly greater than for 68Ga-PSMA-11 (n = 11) [5.5 ± 1.8 versus 3.5 ± 2.7 respectively, p = 0.021]. CONCLUSION: In this exploratory trial, 18F-fluciclovine PET-CT has a significantly higher cDR for ILC metastases compared to standard-of-care imaging and to 68Ga-PSMA-11. Mean SUVmax for true positive malignancy was significantly higher with 18F-fluciclovine than for 68Ga-PSMA-11. Exploratory data from this trial suggests that molecular imaging of amino acid metabolism in patients with ILC deserves further study. CLINICAL TRIAL REGISTRATION: Early phase (I-II) clinical trial (NCT04750473) funded by the National Institutes of Health (R21CA256280).

A Discordant Pattern of Uptake on 68 Ga-PSMA PET/CT Versus 18 F-Fluciclovine PET/CT in Radiation-Induced Hepatitis : Implications for Early Postradiotherapy Imaging-Based Response Assessment.

ABSTRACT: A 62-year-old woman with right-sided invasive lobular breast carcinoma completed external beam radiotherapy 6 weeks before undergoing a 68 Ga-PSMA PET/CT and 18 F-fluciclovine PET/CT scan as part of an ongoing clinical trial (NCT04750473) assessing the performance of these molecular imaging modalities in invasive lobular breast carcinoma. The 68 Ga-PSMA PET/CT demonstrated a band-like area of increased radiotracer uptake in the dome of the right lobe of the liver anteriorly, whereas 18 F-fluciclovine PET/CT done a day later revealed photopenia in the corresponding area of the liver. The external beam radiotherapy plan confirmed that the radiotherapy field overlaid the region of the hepatic discordant radiotracer uptake on the PET/CT scans.

A Tale of 3 Tracers: Contrasting Uptake Patterns of 18F-Fluciclovine, 68Ga-PSMA, and 18F-FDG in the Uterus and Adnexa.

ABSTRACT: A 41-year-old woman with invasive lobular carcinoma of the breast underwent sequential 68Ga-PSMA-11 PET/CT and 18F-fluciclovine PET/CT as part of an ongoing clinical trial (NCT04750473). 68Ga-PSMA PET/CT showed increased radiotracer uptake in the uterine endometrium and left adnexa. 18F-fluciclovine PET/CT showed increased radiotracer uptake in a leiomyomatous uterus. A clinical 18F-FDG PET/CT demonstrated radiotracer uptake in the endometrium and a circumferential area of uptake in the left adnexa, a pattern more similar to the 68Ga-PSMA uptake pattern. This case highlights the discordance in the uptake pattern of 2 radiotracers approved for prostate cancer imaging but increasingly used in non-prostate malignancies imaging.

Minimally Invasive Intact Excision of High-Risk Breast Lesions and Small Breast Cancers: The Intact Percutaneous Excision (IPEX) Registry.

BACKGROUND: Aiming to minimize overtreatment of high-risk breast lesions (HRLs), including atypical ductal hyperplasia, and small breast cancers, including ductal carcinoma in situ (DCIS), we investigated a minimally invasive (MI) approach to definitive diagnosis and management of these conditions. METHODS: In the prospective Intact Percutaneous Excision registry study, women aged 31-86 years had removal of small invasive cancers, DCIS, or HRLs using image-guided 12-20 mm radiofrequency basket capture (MI excision). Second-pass 20 mm basket capture obtained shaved margins in cancer patients. Standard imaging (specimen, breast) and histologic criteria were applied. Patient data were registered in an Institutional Review Board approved, Health Insurance Portability and Accountability Act-compliant registry. RESULTS: Of 282 registered patients, 124 had DCIS (n = 52) or invasive cancer (n = 72) and 160 had HRLs. Among cancer patients, 101 (81%) had clear histologic margins [average lesion size was 11 mm for both invasive cancers (4-20 mm) and DCIS (1.5-20 mm)]; 29 patients had re-excision (six despite clear margins). Among 160 HRLs, two were upgraded to DCIS and had MI excision. Two other HRL patients had subsequent standard surgical excision (no cancer found). CONCLUSION: For diminutive HRLs, DCIS, and invasive cancers, MI excision can achieve the same procedure goals as standard surgical excision. Because MI excision removes less tissue with small incisions, it may reduce the discomfort and expense associated with standard treatment.

Evaluation of percutaneous vacuum assisted intact specimen breast biopsy device for ultrasound visualized breast lesions: Upstage rates and long term follow-up for high risk lesions and DCIS.

OBJECTIVE: Percutaneous core biopsy of ultrasound visualized breast lesions is standard for diagnosis. Large gauge vacuum-assisted core needles have improved accuracy; but a significant underestimation of malignancy remains. The IntactR device was assessed for upstaging and subsequent malignancy at the biopsy site. METHODS: 469 consecutive ultrasound visualized breast lesions, < 2.0 cm in size, BIRADS 4 or 5, biopsied with IntactR Breast Lesion Excision System, between July 2007 and August 2014, were reviewed. All non-concordant lesions (0.8%), DCIS (1.7%) and invasive cancers (9.8%) were surgically excised. Excision was recommended for all high risk lesions (13.0%). The upstage rate to DCIS or invasive cancer was determined. All patients were followed for a median of 66 months (24-96 months) with serial imaging and exams to determine the incidence of re-biopsy, or malignancy at the original biopsy site. RESULTS: 23 of 61 high risk lesions (37.5%) were not excised, but observed for a median of 66 months. None required re-biopsy. One atypical lesion was upstaged to DCIS on excision. No patient was diagnosed with malignancy at or near the original biopsy site during follow-up. Overall upstage rate was 1.2%. CONCLUSIONS: Percutaneous biopsy of ultrasound visualized lesions was performed accurately using IntactR. Upstaging was much lower with IntactR than with large-gauge core needles. High risk lesions, diagnosed with IntactR, have a very low upstage rate at surgical excision. It may be possible to observe these lesions without surgery when they present as ultrasound findings and undergo IntactR biopsy.

A HCO(3)(-)-dependent mechanism involving soluble adenylyl cyclase for the activation of Ca²âº currents in locus coeruleus neurons.

Hypercapnic acidosis activates Ca²âº channels and increases intracellular Ca²âº levels in neurons of the locus coeruleus, a known chemosensitive region involved in respiratory control. We have also shown that large conductance Ca²âº-activated K⁺ channels, in conjunction with this pathway, limits the hypercapnic-induced increase in firing rate in locus coeruleus neurons. Here, we present evidence that the Ca²âº current is activated by a HCO(3)(-)-sensitive pathway. The increase in HCO(3)(-) associated with hypercapnia activates HCO(3)(-)-sensitive adenylyl cyclase (soluble adenylyl cyclase). This results in an increase in cyclic adenosine monophosphate levels and activation of Ca²âº channels via cyclic adenosine monophosphate-activated protein kinase A. We also show the presence of soluble adenylyl cyclase in the cytoplasm of locus coeruleus neurons, and that the cyclic adenosine monophosphate analogue db-cyclic adenosine monophosphate increases Ca²âºi. Disrupting this pathway by decreasing HCO(3)(-) levels during acidification or inhibiting either soluble adenylyl cyclase or protein kinase A, but not transmembrane adenylyl cyclase, can increase the magnitude of the firing rate response to hypercapnia in locus coeruleus neurons from older neonates to the same extent as inhibition of K⁺ channels. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.

An educational innovation to foster evidence-informed practice.

This article describes an innovation in baccalaureate nursing education that is intended to assist in the preparation of nursing students for careers in which evidence-informed practice is an imperative. The innovation involves the combination of central aspects of the internationally recognized Registered Nurses' Association of Ontario Best Practice Guidelines Program with existing curricular goals and themes in a baccalaureate nursing program at a small university in southern Ontario in Canada.

Jadomycins are cytotoxic to ABCB1-, ABCC1-, and ABCG2-overexpressing MCF7 breast cancer cells.

Multidrug resistance remains a major obstacle in the effective treatment of metastatic breast cancer. One mechanism by which multidrug resistance is conferred is the decreased intracellular drug accumulation due to the upregulation of the ATP-binding cassette (ABC) transporters. We have previously demonstrated that jadomycins, polyketide-derived natural products produced by Streptomyces venezuelae ISP5230, inhibit the growth of the human breast ductal carcinoma cell lines T47D and MDA-MB-435. To expand our understanding of jadomycin pharmacology, the goal of the present study was to determine whether the function of ABC efflux transporters affects the anticancer activity of jadomycins to MCF7 breast cancer cells. Seven jadomycin analogs (DNV, B, L, SPhG, F, S, and T) effectively reduced the viability of MCF7 control and ABCB1-, ABCC1-, or ABCG2-overexpressing drug-resistant MCF7 breast cancer cells as measured by methyltetrazolium cell viability assays and lactate dehydrogenase cytotoxicity assays. The inhibition of ABCB1, ABCC1, or ABCG2 with verapamil, MK-571, or Ko-143, respectively, did not augment the cytotoxicity of jadomycins DNV, B, L, SPhG, F, S, or T in drug-resistant MCF7 cells. Furthermore, jadomycins B, L, SPhG, F, S, and T did not increase the intracellular accumulation of ABCB1, ABCC1, or ABCG2 fluorescent substrates in HEK-293 cells stably transfected with ABCB1, ABCC1, or ABCG2. We conclude that jadomycins B, L, SPhG, F, S, and T are effective agents in the eradication of MCF7 breast cancer cells grown in culture, and that their cytotoxicities are minimally affected by ABCB1, ABCC1, and ABCG2 efflux transporter function.

Copper-mediated nuclease activity of jadomycin B.

The natural product jadomycin B, isolated from Streptomyces venezeulae ISP5230, has been found to cleave DNA in the presence of Cu(II) ions without the requirement for an external reducing agent. The efficiency of DNA cleavage was probed using supercoiled plasmid DNA in buffered solution as a model environment. EC50 and t(½) values for cleavage were 1.7 µM and 0.75 h, respectively, and varied ± 5% with the particular batch of plasmid and jadomycin employed. While UV-vis spectroscopy indicates that the cleavage event does not involve direct binding of jadomycin B to DNA, a stoichiometric Cu(II) preference for optimum cleavage suggests a weak binding interaction between jadomycin B and Cu(II) in the presence of DNA. The Cu(II)-mediated cleavage is greatly enhanced by UV light, which implicates the jadomycin B radical cation and Cu(I) as potential intermediates in DNA cleavage. Evidence in favor of this hypothesis was derived from a mechanistic assay which showed reduced cleavage as a function of added catalase and EDTA, scavengers of H2O2 and Cu(II), respectively. Thus, jadomycin B may serve as a source of electrons for Cu(II) reduction, producing Cu(I) which reacts with H2O2 to form hydroxyl radicals that cause DNA strand scission. In addition, scavengers of hydroxyl radicals and superoxide also display inhibitory effects, underscoring the ability of jadomycin B to produce a powerful arsenal of deleterious oxygen species when copper is present.

A low-dose ipsilateral lung restriction improves 3-d conformal planning for partial breast radiation therapy.

In trials of 3D conformal external beam partial breast radiotherapy (PBRT), the dosimetrist must balance the priorities of achieving high conformity to the target versus minimizing low-dose exposure to the normal structures. This study highlights the caveat that in the absence of a low-dose lung restriction, the use of relatively en-face fields may meet trial-defined requirements but expose the ipsilateral lung to unnecessary low-dose radiation. Adding a low-dose restriction that ≤ 20% of the ipsilateral lung should receive 10% of the prescribed dose resulted in successful plans in 88% of cases. This low-dose lung limit should be used in PBRT planning.

Diverse DNA-cleaving capacities of the jadomycins through precursor-directed biosynthesis.

Gel mobility assays were used to establish that some members of the jadomycin family of natural products act as DNA cleaving agents. Moreover, it was found that subtle structural changes generated through the use of precursor-directed biosynthesis lead to marked effects on the DNA-damaging properties of these glycosylated polyketide-derived natural products.

Antimicrobial activities of jadomycin B and structurally related analogues.

Natural products are leads for new antibiotics as a result of their structural complexity and diversity. We have isolated a series of structurally related polyketide-derived natural products from Streptomyces venezuelae ISP5230. The most active of these jadomycin analogues showed good activity against a variety of staphylococci, including methicillin-resistant Staphylococcus aureus.

Stereochemical integrity of oxazolone ring-containing jadomycins.

The jadomycins are a series of natural products produced by Streptomyces venzuelae ISP5230 in response to ethanol shock. A unique structural feature of these angucyclines is the oxazolone ring, the formation of which is catalyzed by condensation of a biosynthetic aldehyde intermediate and an amino acid. The feeding of enantiomeric forms of alpha-amino acids indicates that the amino acid is incorporated by S. venezuelae ISP5230 without isomerization at the alpha-carbon. The characterization of the first two six-membered E-ring-containing jadomycins is reported. These precursor-directed biosynthesis studies indicate flexibility in the acceptor substrate specificity of the glycosyltransferase, JadS. Analysis of cytotoxicity data against two human breast cancer cell lines indicates that the nature of the substitution at the alpha-carbon, rather than the stereochemistry, influences biological activity.

Substrate flexibility of a 2,6-dideoxyglycosyltransferase.

We report the first 2,6-dideoxysugar-O-glycosyltransferase with substrate flexibility at the 2 position, confirm the function of a putative NDP-hexose 2,3-dehydratase in the jadomycin B biosynthetic gene cluster and deduce the substrate flexibility of downstream enzymes in l-digitoxose assembly, enabling reprogramming of biosynthetic gene clusters to modify sugar substituents.

Culture conditions improving the production of jadomycin B.

The jadomycins are a unique family of benzoxazolophenanthridine antibiotics produced by Streptomyces venezuelae ISP5230 following heat or ethanol shock or phage infection. We have modified the culture conditions by altering the carbon source, buffer, inoculum size, and timing of ethanol shock, thereby reducing growing times and improving jadomycin B production. Our optimized conditions use glucose as the carbon source, MOPS as buffer, low concentrations of phosphate, a defined inoculum concentration and an immediate ethanol shock to induce jadomycin B production; results that contrast previous studies. The altered media will facilitate the isolation of related jadomycin B congeners.

Ring-opening dynamics of jadomycin A and B and dalomycin T.

[structure: see text] A novel oxazolone ring-opening and interconversion process between the two jadomycin diastereomeric forms has been characterized by NMR spectroscopy. An analogue, dalomycin T, has been isolated for the first time and does not undergo interconversion.

Novel and expanded jadomycins incorporating non-proteogenic amino acids.

Jadomycin B is a secondary metabolite produced, in response to stress, by Streptomyces venezuelae ISP5230 grown in nutrient-deprived media. We present definitive electrospray ionization mass spectrometry data identifying a series of novel jadomycins with non-proteogenic amino acids incorporated into the oxazolone ring of the secondary metabolite, and strengthening evidence for the existence of an aldimine intermediate in the biosynthetic pathway. We also demonstrate that the size of the oxazolone ring can be expanded by incorporating beta-amino acids.

Modifying the two-stage cleft palate surgical correction.

OBJECTIVE: This paper reports the experience with a two-stage approach to surgical correction of the complete cleft palate, wherein timing of the second stage is dependent on the judgment of the speech pathologist and the orthodontist together with the surgeon. PATIENTS: Of a total of 35 patients having complete unilateral clefts a sample of 22 were available for postsurgical assessment. The first-stage repair of the palate was carried out at an average age of 10.7 months (range 6 to 17 months), and the second-stage repair of the residual cleft was completed at an average age of 32.7 months (range 26 to 34 months). INTERVENTIONS: The first-stage repair of the soft palate defect involved mobilizing two short posteriorly based flaps, which extend onto the posterior quarter of the hard palate thus including up to 1 cm of mucoperiosteum. Careful freeing of the muscle is followed by an intravelar veloplasty. The later closure of the residual cleft involved turnover hinge flaps and small mucoperiosteal flaps. RESULTS: Eighty-seven percent of the sample had good to excellent speech as assessed by the Great Ormond Street screening method. Only two patients showed evidence of recessive maxillae with Class III malocclusions. CONCLUSIONS: A two-stage surgical closure of the palate using this procedure would appear to confer several valuable advantages to the patient. These include favorable outcomes for speech in the large majority of cases and minimal adverse effects on the growth of the midface region.