Real-world evidence analysis of palbociclib prescribing patterns for patients with advanced/metastatic breast cancer treated in community oncology practice in the USA one year post approval.

BACKGROUND: Rapidly evolving understanding of cancer biology has presented novel opportunities to translate that understanding into clinically relevant therapy. Palbociclib, a novel, first-in-class cyclin-dependent kinase (CDK) 4/6 inhibitor was approved in the USA in February 2015 for the treatment of advanced/metastatic breast cancer. We examined real-world evidence in the first year post approval to understand the clinical and demographic characteristics of patients treated with palbociclib in community oncology practices and the dosing, treatment, and complete blood count (CBC) monitoring patterns. METHODS: This was a retrospective observational study of structured data from a US electronic medical record (EMR) database. Female patients receiving palbociclib after 31 January 2015 were followed through 31 March 2016. Our methodological rules were constructed to aggregate drugs received according to the order in which they are given, i.e., identify the line of therapy as first, second, or third line, etc., using treatment order and course description fields from the EMR. RESULTS: There were 763 patients initiating palbociclib who met the selection criteria. Of those, 612 (80.2%) received palbociclib concomitantly with letrozole. Mean follow up was 6.4 months and mean age at palbociclib initiation was 64 years. Of patients with a known starting dose (n = 417), 79.9% started on palbociclib 125 mg. Dose reductions were observed in 20.1% of patients. Percentages of patients according to line of therapy at initiation of palbociclib were first-line, 39.5%; second-line, 15.7%; third-line, 13.1%; and fourth-line therapy or later, 31.7%. On average, two CBC tests were conducted during the first cycle of palbociclib treatment. Overall, 74.6% of patients had a neutropenic event during follow up including 47.3% and 8.0% of patients with a grade 3 or 4 occurrence, respectively. CONCLUSIONS: Real-world palbociclib use one year post US approval demonstrates a more heterogeneous patient population than that studied in the clinical trials with more than half of the patients receiving palbociclib plus letrozole in later lines of therapy. CBC testing rates suggested good provider compliance with monitoring guidelines in the USA prescribing information. The occurrence of grade 3 and 4 neutropenia (based on laboratory results) was consistent with the rates of grade 3 and 4 neutropenia in two phase-III studies (PALOMA-2, 56% and 10%; PALOMA-3, 55% and 11%, respectively). Understanding palbociclib utilization in real-world patients and how drug dosing and monitoring are performed aids in the understanding of safe and effective use of the drug.

Thrombotic microangiopathies of pregnancy: Differential diagnosis.

Thrombotic microangiopathy (TMA) disorders are characterized by microangiopathic hemolytic anemia, thrombocytopenia and end-organ injury. In pregnancy and postpartum, TMA is most commonly encountered with HELLP (hemolysis, elevated liver enzymes, low platelet count syndrome) or preeclampsia with severe features, but rarely TMA is due to thrombotic thrombocytopenic purpura (TTP) or atypical hemolytic uremic syndrome (aHUS). Due to overlapping clinical and laboratory features, TTP and aHUS are often mistaken for preeclampsia or HELLP. Unfortunately, delays in appropriate diagnosis and treatment may be life-threatening. Our objective is to alert obstetrician-gynecologists, certified nurse midwives, family medicine providers, and subspecialty consultants, to the range of TMA disorders that may occur in and around pregnancy. To do this, we have provided a review of individual disorders that comprise the differential diagnosis of pregnancy TMA, and we have proposed a systematic approach to make an accurate diagnosis with readily available clinical and laboratory data. In complex or critical cases, we recommend a multidisciplinary team approach (e.g., Critical Care, Hematology, Maternal Fetal Medicine, Nephrology) to expedite diagnosis and treatment, which may be life-saving.

Eculizumab for the treatment of preeclampsia/HELLP syndrome.

Severe preeclampsia with hemolysis, elevated liver enzymes and low platelets (HELLP) syndrome is a leading cause of maternal and neonatal morbidity and mortality worldwide. Occurrence at an extremely premature gestational age is most challenging as there are dichotomous imperatives: delivery as definitive therapy for maternal health vs. prolongation of pregnancy to avoid prematurity and associated morbidities. We describe a patient presenting with severe preeclampsia/HELLP syndrome at 26 weeks gestation that was treated with Eculizumab, a targeted inhibitor of complement protein C5, which resulted in marked clinical improvement and complete normalization of lab parameters. Pregnancy was prolonged 17 days, likely resulting in a reduction of neonatal morbidity with its associated short and long-term health care costs. Successful use of Eculizumab in this case suggests that complement inhibition may be an effective treatment strategy for severe preeclampsia/HELLP syndrome.

Measurement of vacuum-assisted photoionization at 1 GeV for Au and Ag targets.

We report a measurement of photon impact ionization of K and L shell of Au and K shell of Ag targets in the 1-GeV energy range. We show that the cross section is dominated by a contribution from a new channel called vacuum-assisted photoionization. In this process the energy-momentum balance associated with the removal of the innershell electron is obtained by conversion of a high-energy photon into an electron-positron pair. This measurement is consistent with the theoretical prediction that vacuum-assisted photoionization is the most probable ionization mechanism at very high energies.

Early prenatal sonographic diagnosis of twin triploid gestation presenting with fetal hydrops and theca-lutein ovarian cysts.

The presence of theca-lutein ovarian cysts in the early second trimester of pregnancy is highly suspicious for a complete hydatidiform molar pregnancy but can be seen in association with a partial mole. Theca-lutein cysts may occur following hormonal stimulation for assisted reproductive techniques or in association with multiple gestations. Rare causes include immune and nonimmune fetal hydrops, maternal hypothyroidism, and triploid gestations. We report a case of a monochorionic twin gestation in which prenatal sonography demonstrated multiple anomalies and hydrops in each twin and bilateral theca-lutein ovarian cysts. Triploidy in both twins and a partial hydatidiform mole were confirmed at pathologic examination.

Cervical hydrosonography in pregnancy to assess cervical length by transabdominal ultrasound.

BACKGROUND: Some women's cervices cannot be evaluated because they are obscured by obesity or vertex-presenting fetuses. Measuring cervical length in these cases is difficult or impossible. TECHNIQUE: We hypothesized that the problem of obscured cervices on transabdominal ultrasound could be resolved by introducing sterile water into the vagina, creating a hydroacoustic window between the vaginal lumen and the cervix. Women with unmeasurable cervices on transabdominal ultrasound had repeat studies after introduction of 60 mL of sterile water into their vaginas, and cervical length measurements taken were compared with those made on transvaginal scans. EXPERIENCE: Six pregnant women were studied (four singleton, one twin, and one triplet pregnancy). In all cases, previously unidentifiable cervices were seen adequately. No complications were noted. Statistical analysis (kappa 0.66) suggested good correlation between transabdominal cervical hydrosonography and transvaginal measurements of cervical length. CONCLUSION: Introducing water into the vagina at transabdominal ultrasound can make an obscured cervix visible and measurable.

Using entropies of reaction to predict changes in protein stability: tyrosine-67-phenylalanine variants of rat cytochrome c and yeast Iso-1 cytochromes c.

Using the voltammetric method of square-wave voltammetry, a direct electrochemical examination was made of the wild type and Tyr67Phe mutant of both rat cytochrome c and yeast iso-1-cytochrome c. In addition to determining the equilibrium reduction potential (E0') for each cytochrome, the entropy of reaction, deltaS0'(Rxn)(deltaS0'(Rxn) = S0'(Red) - S0'(Ox)), for the reduction process was determined via the non-isothermal method. Having determined deltaS0'(Rxn) and E0', deltaH0' was calculated. For rat cytochrome c, it was found that deltaS0'(Rxn) = -43 J mol(-1) K(-1) for the wild type and -53 J mol(-1) K(-1) for the Tyr67Phe variant, with the deltaH0' for both the wild type and variant nearly identical, indicating that the changes in reduction potential and probably stability are due to changes in deltaS0'(Rxn). In contrast the measured deltaS0'(Rxn) for yeast iso-1-cytochrome c demonstrated significant changes in both entropic and enthalpic contributions in going from wild type to mutant cytochrome c. The entropy of reaction provides information regarding the relative degree of solvation, and very likely the degree of compactness, of the oxidized state versus the reduced state of the redox protein. A thermodynamic scheme and stability derivation are presented that show how the entropies of reaction of wild type versus variant cytochromes contribute to and predict changes in stability in going from oxidized to reduced protein. For yeast iso-1-cytochrome c, the thermodynamically predicted change in stability was very close to the experimentally observed value, based on previous differential scanning calorimetric stability measurements. While such data is not available for rat cytochrome c, consideration of the enormously increased local stability of the rat oxidized cytochrome c variant predicts that the reduced rat variant will be even more stable than the already stabilized oxidized variant.

Direct voltammetric observation of redox driven changes in axial coordination and intramolecular rearrangement of the phenylalanine-82-histidine variant of yeast iso-1-cytochrome c.

Direct square-wave and cyclic voltammetric electrochemical examination of the yeast iso-1-cytochrome c Phe82His/Cys102Ser variant revealed the intricacies of redox driven changes in axial coordination, concomitant with intramolecular rearrangement. Electrochemical methods are ideally suited for such a redox study, since they provide a direct and quantitative visualization of specific dynamic events. For the iso-1-cytochrome c Phe82His/Cys102Ser variant, square-wave voltammetry showed that the primary species in the reduced state is the Met80-Fe2+-His18 coordination form, while in the oxidized state the His82-Fe3+-His18 form predominates. The addition or removal of an electron to the appropriate form of this variant serves as a switch to a new molecular form of the cytochrome. Using the 2 x 2 electrochemical mechanism, simulations were done for the cyclic voltammetry experiments at different scan rates. These, in turn, provided relative rate constants for the intramolecular rearrangement/ligand exchange and the equilibrium redox potentials of the participating coordination forms: kb,AC = 17 s-1 for Met80-Fe3+-His18 --> His82-Fe3+-His18 and kf,BD > 10 s-1 for His82-Fe2+-His18 --> Met80-Fe2+-His18; E0' = 247 mV for Met80-Fe3+/2+-His18 couple, E0' = 47 mV for His82-Fe3+/2+-His18 couple, and E0' = 176 mV for the cross-reaction couple, His82-Fe3+-His18 + e- --> Met80-Fe2+-His18. Thermodynamic parameters, including the entropy of reaction, DeltaS0'Rxn, were determined for the net reduction/rearrangement reaction, His82-Fe3+-His18 + e- --> Met80-Fe2+-His18, and compared to those for wild-type cytochrome, Met80-Fe3+-His18 + e- --> Met80-Fe2+-His18. For the Phe82His variant mixed redox couple, DeltaS0'Rxn = -80 J/mol.K compared to DeltaS0'Rxn = -52 J/mol.K for the wild-type cyt c couple without rearrangement. Comparison of these entropies indicates that the oxidized His82-Fe3+-His18 form is highly disordered. It is proposed that this high level of disorder facilitates rapid rearrangement to Met80-Fe2+-His18 upon reduction.

Overall survival of the medical oncologist: a new outcome measurement in cancer medicine.

BACKGROUND: Changing patterns of patient referral, decreasing payments for service provision, confusing network participation and reimbursement, as well as challenges to autonomous clinical decision-making jeopardize the traditional role of the oncologist in delivering cancer care. The cancer patient also may be at risk with unproven cancer delivery systems that displace the oncologist as decision-maker and care provider. The authors have constructed a model that preserves the oncologist's clinical and financial autonomy while meeting marketplace demands for improved access, decreasing costs and preserved quality of care. METHODS: During a 4-year period, a group of private practice medical oncologists initiated a formal business plan to evaluate marketplace needs, then designed and implemented a novel cancer care delivery model. The model required reconfiguring the practice into an integrated Joint Commission on Accreditation of Healthcare Organizations-certified cancer service corporation, providing medical, radiation, and gynecologic oncology. Palliative care, pain management, psychologic, and nutritional services were instituted as well as the vertical integration of home health and hospice care. Clinical pathways and treatment protocols were designed to enhance patient care and facilitate cost-of-care projections in designated populations using a cancer incidence forecasting model. Outcomes analysis are performed as part of ongoing continuous quality improvement, which continues to change this health care delivery system. RESULTS: In the 3 years since implementation of the model, the practice has increased from 16 to 24 physicians, and the number of offices has increased from 12 to 17. Patient encounters, both new and established, have doubled. Cost of services, specifically hospitalization, have been reduced by 50%. Clinical research referrals have increased 300%. Physician compensation has improved >20%. CONCLUSIONS: The model created a low cost, high value provider not burdened by allocated overhead. Decentralized care enhanced community access, which improved patient compliance, enhanced patient satisfaction, decreased hospitalization, and thereby decreased cost. The horizontal structure permited the flexibility for varied purchaser products and politically sensitive physician and hospital provider panels. Consensus-based protocol and pathway determination achieved maximum physician participation, which preserved clinical and financial autonomy, decreased variance, and facilitated clinical research.

Synthetic mutants of Clostridium pasteurianum ferredoxin: open iron sites and testing carboxylate coordination.

The entire polypeptide chains for two new Clostridium pasteurianum ferredoxin (Fd) mutants were prepared with the following site-specific substitutions: Cys11Asp and Cys11 alpha-aminobutyric acid (Cys11 alpha-Aba), the latter being a non-naturally occurring amino acid. Standard t-Boc procedures were used for the synthesis and the peptides. The two apoproteins were reconstituted to the 2[4Fe-4S] holoprotein and their spectroscopic, redox and thermal properties were compared with those of native C.pasteurianum Fds. The fully reconstituted Cys11Asp and Cys11 alpha-Aba mutants were initially found to have both clusters intact, i.e. they were 2[4Fe-4S] ferredoxins. The unconventional ligands of Asp and alpha-Aba led to holo-Fds that were not very stable and easily released an iron to form the [3Fe-4S] cluster, presumably through oxidation. The Cys11 alpha-Aba mutant was somewhat more thermally stable than Cys11Asp. In contrast, while both mutants were less stable than the native protein upon exposure to oxygen, the Cys11 alpha-Aba mutant was less stable than Cys11Asp. The Cys11Gly mutant was also prepared, but all attempts, despite repeated and varied experimental conditions, at reconstitution to the Cys11Gly holo 2[4Fe-4S] Fd were unsuccessful, probably because a Gly-Gly sequence is known to break structure. This work, when compared with molecular biological site-specific mutagenesis, shows some of the advantages of chemical/in vitro reconstitution: certain mutants which cannot be detected as holoproteins by site-specific mutagenesis can be formed after all in vitro. Nonetheless, it seems apparent that altering any of the Cys coordination sites of the Fd clusters results in fundamentally more unstable ferredoxins.

Purification and properties of a low-redox-potential tetraheme cytochrome c3 from Shewanella putrefaciens.

Shewanella putrefaciens is a facultatively anaerobic bacterium in the gamma group of the proteobacteria, capable of utilizing a wide variety of anaerobic electron acceptors. An examination of its cytochrome content revealed the presence of a tetraheme, low-redox-potential (E'o = -233 mV), cytochrome c-type cytochrome with a molecular mass of 12,120 Da and a pI of 5.8. The electron spin resonance data indicate a bis-histidine coordination of heme groups. Reduction of ferric citrate was accompanied by oxidation of the cytochrome. The biochemical properties suggested that this protein was in the cytochrome c3 group, which is supported by N-terminal sequence data up to the first heme binding site.

Solution structure of the oxidized 2[4Fe-4S] ferredoxin from Clostridium pasteurianum.

Following the recently developed approach to the solution structure of paramagnetic high-potential iron-sulfur proteins, the three-dimensional structure in solution of the oxidized Clostridium pasteurianum ferredoxin has been solved by 1H-NMR. The X-ray structure is not available. The protein contains 55 amino acids and two [4Fe-4S] clusters. In the oxidized state, the clusters have S = 0 ground states, but are paramagnetic because of thermal population of excited states. Due to the somewhat small size of the protein and to the presence of two clusters, approximately 55% of the residues have at least one proton with a non-selective T1 smaller than 25 ms. The protein has thus been used as a test system to challenge the present paramagnetic NMR methodology both in achieving an extended assignment and in obtaining a suitable number of constraints. 79% of protein protons have been assigned. Analogy with other ferredoxins of known structure has been of help to speed up the final stages of the assignment, although we have shown that this independent information is not necessary. In addition to dipolar connectivities, partially detected through tailored experiments, 3JHN-H alpha, H-bond constraints and dihedral angle constraints on the Cys chi 2 angles have been generated by using a recently derived Karplus-type relationship for the hyperfine shifts of cysteine beta CH2 protons. In total, 456 constraints have been used in distance geometry calculations. The final quality of the structures is satisfactory, with root-mean-square deviation values of 66 pm and 108 pm for backbone and heavy atoms, respectively. The resulting structure is compared with that of Clostridium acidi urici ferredoxin [Duée, E. D., Fanchon, E., Vicat, J., Sieker, L. C., Meyer, J. & Moulis, J.-M. (1994) J. Mol. Biol. 243, 683-695]. The two proteins are very similar in the overall folding, secondary structure elements and side-chain orientations. The C alpha root-mean-square deviation values between the X-ray-determined C. acidi urici ferredoxin structure and the conformer with lowest energy of the C. pasteurianum ferredoxin family is 78 pm (residues 3-53). Discrepancies in residues 26-28 may arise from the disorder observed in the X-ray structure in that region.

Perceptions of ganja and cocaine in urban Jamaica.

This article, based on ethnographic research, discusses the dynamic relationship between ganja (marijuana) and cocaine in five areas within Montego Bay, an urban-tourist center in Jamaica, West Indies. The focus is on the contrasting and conflicting social perceptions related to the current role of each substance in the society, as well as the interrelationship between these two substances. Of particular interest in the analysis of use and distribution patterns of each substance is the seemingly conflicting moral versus economic dilemma surrounding the drug trade; perceptions related to the effects of these two substances on the body and mind; and perceptions related to the role these substances play in local crime and physical violence. Community-level social perceptions will be compared to official discourse and actions regarding demand reduction, prevention, and enforcement of "drug" laws.

Direct square-wave voltammetry of superoxidized [4Fe-4S]3+ aconitase and associated 3Fe/4Fe cluster interconversions.

We report a direct square-wave voltammetric study of the iron-sulfur enzyme, aconitase, at the pyrolytic graphite edge electrode. New and established redox driven reactions were observed and the equilibrium reduction potential for each couple was determined: E0'[3Fe-4S]1+/0 = -268 mV, E0'[4Fe-4S]2+/1+ = -450 mV, E0'[4Fe-4S]3+/2+ = +100 mV, E0'Linear Form = -281 mV, and putatively, E0'[3Fe-4S]0/2- congruent to -1000 mV, all versus normal hydrogen electrode. Most importantly we have directly observed the superoxidized [4Fe-4S]3+ form of aconitase (originally proposed by Emptage, M. H., Dreyer, J.-L., Kennedy, M. C., and Beinert, H. (1983) J. Biol. Chem. 258, 11106-11111) and directly followed its conversion to the [3Fe-4S]1+ form; this intermediate is required for the deactivation of aconitase. Without exogenous ferrous iron, [3Fe-4S]0 aconitase is apparently super-reduced at very negative potentials to the [3Fe-4S]2- form and the concomitant formation of [4Fe-4S]2+ aconitase was followed over time. It is the apparent decomposition of super-reduced [3Fe-4S]2- aconitase that provides the source of ferrous iron for the interconversion of [3Fe-4S]0 aconitase to the [4Fe-4S]2+ form. Voltammetry of free and substrate bound [4Fe-4S]2+ aconitase showed that the latter is less susceptible to oxidation but, surprisingly, has the same E0'[4Fe-4S]3+/2+.

Cytokine regulation of trophoblast steroidogenesis.

Activated monocytes and lymphocytes secrete cytokines that act as autocrine and paracrine mediators to promote and regulate local immune processes. These cell types are abundant at the maternal-fetal interface, and cytokines may play a role in pregnancy maintenance or failure. The purpose of this study was to determine the effects of selected monocyte- and lymphocyte-derived cytokines on trophoblast progesterone and estradiol production. JEG-3 choriocarcinoma cells were cultured in supplemented medium alone or in various concentrations of selected recombinant monocyte or lymphocyte cytokines. The cytokines were evaluated both individually and in combination. After 48 h of incubation, the culture supernatant was aspirated and stored at -20 C. Samples were then analyzed for steroid concentration by specific RIAs. Specific interleukin-1 (IL-1)-and tumor necrosis factor (TNF)-neutralizing antibodies were evaluated for their ability to abrogate the cytokine's observed stimulatory effect. To evaluate the physiological relevance of the progesterone-stimulating effect observed with monocyte-derived cytokines, JEG-3 cells were incubated with activated monocyte supernatant or directly cocultured with activated monocytes, and supernatants from these cultures were analyzed for progesterone levels. The monocyte cytokines [IL-1 alpha (5 U/mL), IL-1 beta (5 U/mL), and TNF alpha (1000 U/mL) significantly stimulated trophoblast progesterone production (nanograms per mL): JEG-3 control, 4.1 +/- 0.5; IL-1 alpha, 7.8 +/- 0.9; IL-1 beta, 8.8 +/- 0.5; and TNF alpha 7.2 +/- 0.8 (P < 0.05). Neither the monocyte nor the lymphocyte cytokines altered trophoblast estradiol production. Activated monocyte supernatant and direct JEG-3-monocyte cocultures also significantly stimulated trophoblast progesterone production in vitro. The stimulatory effect of the monocyte-derived cytokines was specific, as demonstrated by neutralization assay. The increased trophoblast progesterone production was not due to enhanced cellular proliferation, but to enhance cellular steroidogenesis, as measured by quantitative DNA analysis. The lymphocyte cytokines (IL-2, interferon-gamma, and granulocyte-macrophage colony-stimulating factor had no effect on trophoblast progesterone production. We conclude that monocyte IL-1 alpha, IL-1 beta, and TNF alpha may regulate trophoblast progesterone production through paracrine effects. Monocyte-trophoblast interactions may be significant in normal pregnancy as well as pregnancy disorders.

Immunomodulation of cellular cytotoxicity to herpes simplex virus infection in pregnancy by inhibition of eicosanoid metabolism.

In an effort to evaluate the relationships among pregnancy, cellular cytotoxicity and herpes simplex virus (HSV) infection, we conducted a series of experiments investigating: (1) the maternal cellular cytotoxic response to HSV infection as compared with non-pregnant hosts, (2) the influence of both cyclooxygenase and lipoxygenase products on cytotoxicity by selective inhibition of their metabolic pathways, and (3) the potential pregnancy-related differences in immune response to selective inhibition of eicosanoid metabolism. Indomethacin was used for cyclooxygenase blockade and nordihydroguaiaretic acid was used to evaluate lipoxygenase inhibition. In the non-infected animals no differences in cytotoxicity were observed between pregnant (1.5% +/- 0.7%) and non-pregnant (4.6% +/- 2.0%) groups. HSV infection increased cytotoxicity equally in both groups (pregnant: 10.6% +/- 2.0% vs. non-pregnant: 14.2% +/- 3.4%). Indomethacin did not significantly alter cytotoxicity in either the pregnant or the non-pregnant groups compared with controls (12.8% +/- 1.8% vs. 10.6% +/- 2.0% and 14.3% +/- 3.9% vs. 14.2% +/- 3.4%, respectively). In contrast, NDGA elicited a significant reduction in the cytotoxic response in both pregnant and non-pregnant hosts (6.2% +/- 1.1% vs. 10.6% +/- 2.0% and 5.7% +/- 1.1% vs. 14.2% +/- 3.4%, respectively). From our study we conclude that: (1) cytotoxicity is maintained at low levels in the absence of HSV infection, (2) HSV infection induces a significant augmentation in host cellular cytotoxicity, (3) pregnant and non-pregnant cytotoxic responses to HSV infection appear comparable, (4) indomethacin does not augment in vitro cytotoxicity to HSV infection and (5) NDGA suppresses cytotoxicity, providing evidence that lipoxygenase metabolites are essential to cytotoxic cell function.