Maintenance treatment with cetuximab in a series of patients treated with standard chemotherapy and cetuximab in metastatic colorectal cancer

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Background: New strategies are needed to improve outcomes and reduced toxicities of currently treatments for patients with advanced colorectal cancer. Nowadays maintaining treatment until disease progression is the standard option for these patients. Cetuximab is a recombinant humanized monoclonal antibody that neutralizes epidermal growth factor receptor and it has shown benefit not only in combination with standard chemotherapy in first- and second-line treatment or as a single agent in progression to standard chemotherapy in KRAS wild-type metastatic colorectal cancer (mCRC).

Methods: This data describes patients who received standard chemotherapy with cetuximab every two weeks. For patients with response or stable disease, cetuximab was continued until disease progression or unacceptable toxicity.

Results: Twelve patients are reported, nine were male (75%). The median age was 62 years (range, 46 to 78 years). All patients had stage IV, and liver was the most common location (75%). The majority of patients (75%) received FOLFOX VI as a first-line treatment in combination with cetuximab; only two patients were treated with FOLFIRI. Cetuximab was maintained after the first line of treatment in the 75% of patients. The median of cycles of chemotherapy and cetuximab was 12. Best response achieved in this setting was complete response (58.3%, 7/12). Median of monotherapy with cetuximab treatment was 7.5 cycles (range 3 to 12). At the moment of this analysis seven of twelve patients continued with the maintenance. In the rest of patients the treatment was followed until progression (33%, 3/12). No grade 3-4 toxicities were seen during maintenance cetuximab. The most common adverse effect during maintenance was cutaneous toxicity but the majority of patients had minor toxicity (50% grade 1).

Conclusions: Cetuximab has significant antitumor activity not only as a single agent or in combination with standard chemotherapy but may also when it is used as maintenance therapy after a complete or partial response to first or second line based chemotherapy in mCRC. Maintenance cetuximab is feasible, safe, and worthy of future study in advanced colorectal cancer.

No significant financial relationships to disclose.

An experimental approach to language training in second language acquisition: Focus on negation

The effect of negation training in a second language on the expression of negation in the native language was investigated. Four-year-old children from bilingual (Spanish/English) homes who showed no expressive or receptive ability in Spanish negation and were either proficient or nonproficient in English negation received Spanish negation training. Children who were proficient in English negation maintained correct responses in English and showed increased correct responses in Spanish following simultaneous training in both languages or in Spanish alone. Children who were nonproficient in English negation demonstrated a decrease in correct English responses following training in Spanish alone; however, children who received training in English and Spanish simultaneously showed increases in correct responses in both languages. These findings suggest that language training programs with children learning a second language should consider the relationship of the two language training conditions (simultaneous vs. independent) with the child's level of native language proficiency.

Presence and expression of the mating type locus in Paracoccidioides brasiliensis isolates

Paracoccidioides brasiliensis has been classified in the phylum Ascomycota, order Onygenales, family Ajellomycetaceae, even in the absence of a known sexual cycle or mating system. The objective of this work was to determine the presence of the mating type locus in 71 P. brasiliensis isolates from various sources. A PCR assay using specific primers for the MAT 1 gene was developed and applied for the detection of such genes. Two heterothallic groups (MAT1-1 or MAT1-2) were recognized and, in some isolates, gene expression was confirmed indicating the existence of a basal gene expression. The distribution of two mating type loci in the studied population suggested that sexual reproduction might occur in P. brasiliensis. This finding points towards the possibility of applying a more precise definition of the concept of biological species to P. brasiliensis. Further studies should be conducted to confirm the sexual capacity of this fungus and its implications among phylogenetic species and geographical distribution.

Epidemiological and transmissibility analysis of influenza A(H1N1)v in a southern hemisphere setting: Peru

We present a preliminary analysis of 1,771 confirmed cases of influenza A(H1N1)v reported in Peru by 17 July including the frequency of the clinical characteristics, the spatial and age distribution of the cases and the estimate of the transmission potential. Age-specific frequency of cases was highest among school age children and young adults, with the lowest frequency of cases among seniors, a pattern that is consistent with reports from other countries. Estimates of the reproduction number lie in the range of 1.2 to 1.7, which is broadly consistent with previous estimates for this pandemic in other regions. Validation of these estimates will be possible as additional data become available.

Epidemiological and transmissibility analysis of influenza A(H1N1)v in a southern hemisphere setting: Peru

We present a preliminary analysis of 1,771 confirmed cases of influenza A(H1N1)v reported in Peru by 17 July including the frequency of the clinical characteristics, the spatial and age distribution of the cases and the estimate of the transmission potential. Age-specific frequency of cases was highest among school age children and young adults, with the lowest frequency of cases among seniors, a pattern that is consistent with reports from other countries. Estimates of the reproduction number lie in the range of 1.2 to 1.7, which is broadly consistent with previous estimates for this pandemic in other regions. Validation of these estimates will be possible as additional data become available.

Benefits of continuous subcutaneous insulin infusion in type 1 diabetes previously treated with multiple daily injections with once-daily glargine and pre-meal analogues

BACKGROUND/AIMS

There is insufficient information about the use of continuous subcutaneous insulin infusion (CSII) versus multiple daily injections (MDI) using long-acting insulin analogs in relation to possible metabolic consequences and, as well, on the grade of patient satisfaction. The aim of the study was to evaluate the usefulness of CSII treatment in patients with type 1 diabetes in achieving glycemic objectives using continuous glucose monitoring system (CGMS) and in improving patient's satisfaction with treatment.

METHODS

We have studied 45 type 1 diabetic patients treated with MDI with once-daily glargine and pre-meal rapid-acting insulin analogues, and 20 patients who commenced CSII because they had not achieved a good glycemic control.

RESULTS

With CSII, there were significant reductions in insulin requirements (0.75+/-0.21 vs. 0.64+/-0.21 UI/kg/day; p=0.001), HbA (1c) (7.99+/-0.76 vs. 7.19+/-0.51%; p=0.001) and hypoglycemic episodes (4.60+/-1.82 vs. 3.05+/-1.88 events/patient/week; p=0.031) and improved patient satisfaction with treatment. CSII reduced hyperglycemic episodes in 04:00-08 h period (131.65+/-113.49 vs. 69.70+/-101.52 min; p=0.049), 24 h period area-under-the-curve (AUC) (4521.60+/-3689.23 vs. 3000.36+/-493.96 mmol/L x min; p=0.025) and AUC before dinner (217.36+/-181.46 vs. 136.22+/-202.88 mmol/L x min; p=0.048).

CONCLUSIONS

In selected patients with poor metabolic control with once-daily glargine and pre-meal rapid-acting insulin analogues, CSII is a good alternative since it reduces hypoglycemic episodes and insulin requirement and improves glycemic control and patient's satisfaction.

Observation of the suppression of the flux of cosmic rays above 4 x 10 (19) eV

The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.

Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.

Glutamate and aspartate levels in the nucleus accumbens during cocaine self-administration and extinction: a time course microdialysis study

RATIONALE

Accumbal excitatory amino acid (EAA) transmission has been implicated in cocaine addiction. However, the time course effects of extinction of cocaine self-administration on EAAs are unknown.

OBJECTIVES

The objective of this study was to define the time course of cocaine self-administration and extinction effects on glutamate and aspartate levels in the nucleus accumbens.

MATERIALS AND METHODS

Rats were trained to self-administer cocaine for 20 days, and the levels of extracellular glutamate and aspartate were measured by in vivo microdialysis both during cocaine self-administration and after a priming cocaine injection at different time points after extinction (1, 5, or 10 days). A food-reinforced control group was also included in this study. Furthermore, the effect of acute i.v. cocaine administration (0, 1, 2, or 4 mg/kg) on glutamate and aspartate levels was also evaluated.

RESULTS

At any of the dose tested, acute i.v. cocaine did not affect the levels of glutamate or aspartate in the Nacc. In contrast, glutamate levels were reduced in animals trained to self-administer cocaine, although they augmented substantially during a subsequent session of cocaine self-administration, and similar changes were not observed in food-reinforced controls. After 1 or 5, but not after 10 days of extinction, the glutamate levels were also reduced, and the ability of i.v. cocaine priming injections to increase glutamate levels followed a similar time course. These effects were specific, as aspartate levels were not affected by any administration protocol.

CONCLUSIONS

These data suggest that glutamatergic transmission could be involved in the maintenance of cocaine self-administration and in the early phases of abstinence.

Genome size and ploidy of Paracoccidioides brasiliensis reveals a haploid DNA content: Flow cytometry and GP43 sequence analysis

The aim of this study was to evaluate genome size and ploidy of the dimorphic pathogenic fungus Paracoccidioides brasiliensis. The cell cycle analysis of 10 P. brasiliensis isolates by flow cytometry (FCM) revealed a genome size ranging from 26.3+/-0.1Mb (26.9+/-0.1fg) to 35.5+/-0.2Mb (36.3+/-0.2fg) per uninucleated yeast cell. The DNA content of conidia from P. brasiliensis ATCC 60855-30.2+/-0.8Mb (30.9+/-0.8fg) -showed no significant differences with the yeast form, possibly excluding the occurrence of ploidy shift during morphogenesis. The ploidy of several P. brasiliensis isolates was assessed by comparing genome sizing by FCM with the previously described average haploid size obtained from electrophoretic karyotyping. The analysis of intra-individual variability of a highly polymorphic P. brasiliensis gene, GP43, indicated that only one allele seems to be present. Overall, the results showed that all analysed isolates presented a haploid, or at least aneuploid, DNA content and no association was detected between genome size/ploidy and the clinical-epidemiological features of the studied isolates. This work provides new knowledge on P. brasiliensis genetics/genomics, important for future research in basic cellular/molecular mechanisms and for the development/design of molecular techniques in this fungus.

The effects of morphine self-administration on cortical pyramidal cell structure in addiction-prone lewis rats

The consumption of drugs of abuse provokes sensitization, the development of tolerance, dependency, and eventually addiction. It is thought that these events are partially a consequence of drug-induced alterations in the organization of neuronal circuits in specific areas of the brain. In the present study, we have used intracellular injections of lucifer yellow to examine the alterations that may occur in cortical pyramidal neurons of addiction-prone Lewis rats following 15 days of self-administration of morphine. Specifically, the effects of morphine on the structure, size and branching complexity of the basal dendrites, and spine density were determined in the basal dendritic arbors of layer III pyramidal neurons in both the prelimbic and motor cortex. We found that following morphine self-administration, there was a reduction in the size and branching complexity of the dendritic arbors of pyramidal cells in the motor cortex. In contrast, prelimbic pyramidal neurons from these morphine-treated animals had larger and longer basal dendritic arbors. Furthermore, the spine density on pyramidal neurons was higher in both cortical regions of morphine self-administered rats. These results suggest that at least part of the behavioral changes produced by repeated opiate administration may be attributed to alterations in pyramidal cell structure.

Low-Temperature Rotational Relaxation of CO in Self-Collisions and in Collisions with Ne and He

The low-temperature rotational relaxation of CO in self-collisions and in collisions with the rare-gas atoms Ne and He has been investigated in supersonic expansions with a combination of resonance-enhanced multiphoton ionization (REMPI) spectroscopy and time-of-flight techniques. For the REMPI detection of CO, a novel 2 + 1' scheme has been employed through the A(1)Pi state of CO. From the measured data, average cross sections for rotational relaxation have been derived as a function of temperature in the range 5-100 K. For CO-Ne and CO-He, the relaxation cross sections grow, respectively, from values of approximately 20 and 7 A(2) at 100 K to values of approximately 65-70 and approximately 20 A(2) in the 5-20 K temperature range. The cross section for the relaxation of CO-CO grows from a value close to 40 A(2) at 100 K to a maximum of 60 A(2) at 20 K and then decreases again to 40 A(2) at 5 K. These results are qualitatively similar to those obtained previously with the same technique for N(2)-N(2), N(2)-Ne, and N(2)-He collisions, although in the low-temperature range (T < 20 K) the CO relaxation cross sections are significantly larger than those for N(2). Some discrepancies have been found between the present relaxation cross sections for CO-CO and CO-He and the values derived from electron-induced fluorescence experiments.

Multiple pulmonary neoplasia positive for thyroglobulin

We present, for the first time, a case of carcinoid metastatic pulmonary tumor positive for thyroglobulin. A 73-yr-old woman diagnosed with metastases of probable thyroid carcinoma, manifested by a mediastinic mass and multiple pulmonary nodules positive for radioiodine (I131). Histological analysis showed typical findings of carcinoid tumor with positive immunohistochemistry for neuron-specific enolase, synaptophysin and thyroglobulin, and negative for chromogranin and calcitonin. We underline the exceptional finding of positive reaction for thyroglobulin, and discuss difficulties in differential diagnosis between metastatic differentiated thyroid and carcinoid neoplasms.

Observation of a narrow charm-strange meson D(+)(sJ)(2632)-->D(+)(s)eta and D(0)K(+)

We report the first observation of a charm-strange meson D(+)(sJ)(2632) at a mass of 2632.5+/-1.7 MeV/c(2) in data from SELEX, the charm hadro-production experiment E781 at Fermilab. This state is seen in two decay modes, D(+)(s)eta and D0K+. In the D(+)(s)eta decay mode we observe a peak with 101 events over a combinatoric background of 54.9 events at a mass of 2635.4+/-3.3 MeV/c(2). There is a corresponding peak of 21 events over a background of 6.9 at 2631.5+/-2.0 MeV/c(2) in the decay mode D0K+. The decay width of this state is <17 MeV/c(2) at 90% confidence level. The relative branching ratio Gamma(D0K+)/Gamma(D(+)(s)eta) is 0.14+/-0.06. The mechanism that keeps this state narrow is unclear. Its decay pattern is also unusual, being dominated by the D(+)(s)eta decay mode.

Photodissociation and multiphoton dissociative ionization processes in CH3S2CH3 at 193 nm studied using velocity-map imaging

Dissociation and ionization processes in dimethyl disulfide, CH(3)S(2)CH(3), induced by one- or two-photon absorption of 193 nm light, have been studied using velocity-map ion imaging. The analysis of the ion images of the CH(3)S(2) (+), CH(3)S(+), S(2) (+), and S(+) fragments has allowed the characterization of the scattering dynamics of some of the main photolysis and dissociative-ionization processes. In particular, the experiments corroborate the formation of electronically excited SCH(3)((2)A(1)) products in the 193 nm photodissociation of dimethyl disulfide seen in earlier studies, and show that laser ionization provides a very sensitive method for their detection. The data have also allowed determination of the recoil energy and angular distributions of the CH(3)S(2) (+) and CH(3)S(+) products of the two-photon dissociative-ionization of the CH(3)S(2)CH(3) molecule. The measured distributions for these products are consistent with the formation of a transient parent ion which dissociates after a substantial intramolecular rearrangement, possibly yielding the most stable isomeric forms of the fragments, namely CH(2)S(2)H(+) and CH(2)SH(+).