Phase I-II study of vorinostat plus paclitaxel and bevacizumab in metastatic breast cancer: evidence for vorinostat-induced tubulin acetylation and Hsp90 inhibition in vivo

In preclinical models, the histone deacetylase inhibitor vorinostat sensitizes breast cancer cells to tubulin-polymerizing agents and to anti-vascular endothelial growth factor-directed therapies. We sought to determine the safety and efficacy of vorinostat plus paclitaxel and bevacizumab as first-line therapy in metastatic breast cancer (MBC), and the biological effects of vorinostat in vivo. For this purpose of this study, 54 patients with measurable disease and no prior chemotherapy for MBC received vorinostat (200 or 300 mg PO BID) on days 1-3, 8-10, and 15-17, plus paclitaxel (90 mg/m(2)) on days 2, 9, 16, and bevacizumab (10 mg/kg) on days 2 and 16 every 28 days. The primary objective of the phase I study was to determine the recommended phase II dose (RPTD) of vorinostat, and for the phase II to detect an improvement of response rate from 40 to 60% (alpha = 0.10, beta = 0.10). No dose limiting toxicities were observed, and the RPTD of vorinostat was 300 mg BID. For the primary efficacy analysis in 44 patients at the RPTD, we observed 24 objective responses (55%, 95% confidence intervals (C.I) 39%, 70%). The adverse event profile was consistent with paclitaxel-bevacizumab, with the exception of increased diarrhea with the addition of vorinostat. Analysis of serial tumor biopsies in seven patients showed increased acetylation of Hsp90 and α-tubulin following vorinostat. Vorinostat induces histone and alpha tubulin acetylation and functional inhibition of Hsp90 in breast cancer in vivo and can be safely combined with paclitaxel and bevacizumab.

VL, Martinelli GP, Ogorodnikov D, Yakushin SB, Cohen B. Fos expression in neurons of the rat vestibulo-autonomic pathway activated by sinusoidal galvanic vestibular stimulation

The vestibular system sends projections to brainstem autonomic nuclei that modulate heart rate and blood pressure in response to changes in head and body position with regard to gravity. Consistent with this, binaural sinusoidally modulated galvanic vestibular stimulation (sGVS) in humans causes vasoconstriction in the legs, while low frequency (0.02-0.04 Hz) sGVS causes a rapid drop in heart rate and blood pressure in anesthetized rats. We have hypothesized that these responses occur through activation of vestibulo-sympathetic pathways. In the present study, c-Fos protein expression was examined in neurons of the vestibular nuclei and rostral ventrolateral medullary region (RVLM) that were activated by low frequency sGVS. We found c-Fos-labeled neurons in the spinal, medial, and superior vestibular nuclei (SpVN, MVN, and SVN, respectively) and the parasolitary nucleus. The highest density of c-Fos-positive vestibular nuclear neurons was observed in MVN, where immunolabeled cells were present throughout the rostro-caudal extent of the nucleus. c-Fos expression was concentrated in the parvocellular region and largely absent from magnocellular MVN. c-Fos-labeled cells were scattered throughout caudal SpVN, and the immunostained neurons in SVN were restricted to a discrete wedge-shaped area immediately lateral to the IVth ventricle. Immunofluorescence localization of c-Fos and glutamate revealed that approximately one third of the c-Fos-labeled vestibular neurons showed intense glutamate-like immunofluorescence, far in excess of the stain reflecting the metabolic pool of cytoplasmic glutamate. In the RVLM, which receives a direct projection from the vestibular nuclei and sends efferents to preganglionic sympathetic neurons in the spinal cord, we observed an approximately threefold increase in c-Fos labeling in the sGVS-activated rats. We conclude that localization of c-Fos protein following sGVS is a reliable marker for sGVS-activated neurons of the vestibulo-sympathetic pathway.

Orientation adaptation of eye movement-related vestibular neurons due to prolonged head tilt

Sixteen neurons, including vestibular-only (VO), eye-head velocity (EHV), and position-vestibular-pause (PVP) neurons sensitive to head tilt were recorded in the rostromedial and in superior vestibular nuclei. Projection of the otolith polarization vector to the horizontal plane (response vector orientation [RVO]) was determined before and after prolonged head orientation in side-down position. The RVO of VO neurons shifted toward alignment with the axis of gravity when the head was in the position of adaptation. PVP neurons had similar changes in RVO. There were also changes in RVO in some EHV neurons, but generally in directions not related to gravity. Modeling studies have suggested that the tendency to align RVOs with gravity leads to tuning of gravity-dependent angular vestibular ocular reflex (aVOR) gain changes to the position of adaptation. Thus, coding of orientation in PVP neurons would contribute significantly to the gravity-dependent adaptation of the aVOR.

Motion sickness on tilting trains

Trains that tilt on curves can go faster, but passengers complain of motion sickness. We studied the control signals and tilts to determine why this occurs and how to maintain speed while eliminating motion sickness. Accelerometers and gyros monitored train and passenger yaw and roll, and a survey evaluated motion sickness. The experimental train had 3 control configurations: an untilted mode, a reactive mode that detected curves from sensors on the front wheel set, and a predictive mode that determined curves from the train's position on the tracks. No motion sickness was induced in the untilted mode, but the train ran 21% slower than when it tilted 8° in either the reactive or predictive modes (113 vs. 137 km/h). Roll velocities rose and fell faster in the predictive than the reactive mode when entering and leaving turns (0.4 vs. 0.8 s for a 4°/s roll tilt, P<0.001). Concurrently, motion sickness was greater (P<0.001) in the reactive mode. We conclude that the slower rise in roll velocity during yaw rotations on entering and leaving curves had induced the motion sickness. Adequate synchronization of roll tilt with yaw velocity on curves will reduce motion sickness and improve passenger comfort on tilting trains.

Paternal germ cell mosaicism in autosomal dominant pachyonychia congenita

BACKGROUND

Pachyonychia congenita (PC) is a genodermatosis caused by mutations in 1 of 4 known keratin genes, including KRT6A, KRT6B, KRT16, or KRT17. The most common mode of inheritance is autosomal dominant. Families with an affected parent are routinely counseled about the 50% transmission risk to each offspring. In some cases, families with a rare disorder like PC can initially present with an affected child while both parents are unaffected. This is usually the result of a spontaneous in utero mutation, and the risk of subsequent offspring being affected with the same condition is negligible (but may be increased above the general population's risk, although the exact risk is not currently known for PC).

OBSERVATIONS

We discuss a case of 2 affected children born to unaffected parents. We performed mutational analyses of all 4 individuals in the family on DNA extracted from lymphocytes. Owing to the unusual presentation of 2 affected siblings, we also extracted DNA from the father's sperm cells for keratin gene mutational analysis. We describe the first case, to our knowledge, of germ cell mosaicism in PC.

CONCLUSION

Counseling of unaffected parents with a first child diagnosed as having PC should entail a discussion of the possibility of germ cell mosaicism contributing to an increased risk of having subsequent affected children.

Urinary Met level as a novel biomarker for urothelial carcinoma of the bladder

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Background: To determine whether urinary soluble Met (sMet) can differentiate between benign conditions and bladder cancer (CaB), and in cases of bladder cancer, between different stages of transitional cell carcinoma (TCC).

Methods: Urinary samples from patients with (Total: 63, pTa: 12, pTis: 22, pT1: 13, ≥ pT2: 16) and without (Total: 27) CaB from three different institutions were prospectively collected prior to cystosopy, TURBT or cystectomy. sMet levels were determined by electrochemiluminescence immunoassay and normalized to urinary creatinine values. Normalized sMet values were compared to final pathologic stage. AUC values were obtained comparing patients with and without TCC.

Results: Urinary sMet levels accurately differentiated between patients with and without CaB (AUC: 78%, sensitivity, specificity and negative predictive value were: 68%, 78% and 95%, respectively), patients with no CaB and those with lamina propria invasion (AUC: 79%, sensitivity, specificity and negative predictive value were: 65%, 81% and 95%, respectively) and patients with no CaB and those with muscle invasive CaB (AUC: 85%, sensitivity, specificity and negative predictive value were: 75%, 83% and 97%, respectively).

Conclusions: Urinary sMet levels accurately distinguish patients with CaB from those without, and between patients with different CaB stages. These results suggest that urinary sMet may have utility as a bladder cancer marker for screening, treatment follow-up and clinical trial design.

No significant financial relationships to disclose.

Oral propranolol therapy for infantile hemangiomas beyond the proliferation phase: a multicenter retrospective study

Pharmacological therapies for infantile hemangiomas were considered effective only during the proliferative phases. Recently reported beneficial effects of propranolol may extend beyond the proliferative phase of infantile hemangiomas. The purpose of the study was to assess the effect of oral propranolol therapy for infantile hemangiomas beyond the proliferative phase of these lesions. Members of the Society for Pediatric Dermatology were invited to participate in a multicenter retrospective study. Only children with infantile hemangiomas with documented cessation of lesions' growth or those older than 12 months of age were eligible for the study. Clinical and demographic information and digital photographs before, at the start, and following the treatment were collected. Scaled panels of photographs were distributed among preselected experienced pediatric dermatologists. Visual analog scale was used to assess photographs for each case. Paired t-test was used for statistical analyses. Data on 49 eligible patients from eight pediatric dermatology centers was collected. Seven cases were excluded because of insufficient photographic documentation. The age of the patients at the start of propranolol therapy ranged 7 to 120 months (mean 28 mos, median 22 mos). The duration of propranolol therapy ranged 1 to 8 months (mean 3.6 mos). The mean visual analog scale score before the treatment was 6.8 ± 2.15, and mean reduction in the visual analog scale score at the assessment was 2.6 ± 1.74 (p < 0.001). The rate of visual analog scale reduction was 0.4 per month before the start of the therapy, while this rate was accelerated to 0.9 per months following the therapy (p < 0.001). No significant side effects were reported. We conclude that propranolol is effective in infantile hemangiomas, including post-proliferative phase, and should be considered as the first-line therapy in that setting.

Spatial orientation of the angular vestibulo-ocular reflex (aVOR) after semicircular canal plugging and canal nerve section

We investigated spatial responses of the aVOR to small and large accelerations in six canal-plugged and lateral canal nerve-sectioned monkeys. The aim was to determine whether there was spatial adaptation after partial and complete loss of all inputs in a canal plane. Impulses of torques generated head thrusts of ≈ 3,000°/s². Smaller accelerations of ≈ 300°/s² initiated the steps of velocity (60°/s). Animals were rotated about a spatial vertical axis while upright (0°) or statically tilted fore-aft up to ± 90°. Temporal aVOR yaw and roll gains were computed at every head orientation and were fit with a sinusoid to obtain the spatial gains and phases. Spatial gains peaked at ≈ 0° for yaw and ≈ 90° for roll in normal animals. After bilateral lateral canal nerve section, the spatial yaw and roll gains peaked when animals were tilted back ≈ 50°, to bring the intact vertical canals in the plane of rotation. Yaw and roll gains were identical in the lateral canal nerve-sectioned monkeys tested with both low- and high-acceleration stimuli. The responses were close to normal for high-acceleration thrusts in canal-plugged animals, but were significantly reduced when these animals were given step stimuli. Thus, high accelerations adequately activated the plugged canals, whereas yaw and roll spatial aVOR gains were produced only by the intact vertical canals after total loss of lateral canal input. We conclude that there is no spatial adaptation of the aVOR even after complete loss of specific semicircular canal input.

Prolonged reduction of motion sickness sensitivity by visual-vestibular interaction

The angular vestibulo-ocular reflex (aVOR) and optokinetic nystagmus (OKN) were elicited simultaneously at low frequencies to study effects of habituation of the velocity storage time constant in the vestibular system on motion sickness. Twenty-nine subjects, eleven of whom were susceptible to motion sickness from common transportation, were habituated by sinusoidal rotation at 0.017 Hz at peak velocities from 5 to 20°/s, while they watched a full-field OKN stimulus. The OKN stripes rotated in the same direction and at the same frequency as the subjects, but at a higher velocity. This produced an OKN opposite in direction to the aVOR response. Motion sickness sensitivity was evaluated with off-vertical axis rotation (OVAR) and by the response to transportation before and after 5 days of visual-vestibular habituation. Habituation did not induce motion sickness or change the aVOR gains, but it shortened the vestibular time constants in all subjects. This greatly reduced motion sickness produced by OVAR and sensitivity to common transport in the motion susceptible subjects, which persisted for up to 18 weeks. Two motion susceptible subjects who only had aVOR/OKN habituation without being tested with OVAR also became asymptomatic. Normal subjects who were not habituated had no reduction in either their aVOR time constants or motion sickness sensitivity. The opposing aVOR/OKN stimulation, which has not been studied before, was well tolerated, and for the first time was an effective technique for rapid and prolonged habituation of motion sickness without exposure to drugs or other nauseating habituation stimuli.

Complementary gain modifications of the cervico-ocular (COR) and angular vestibulo-ocular (aVOR) reflexes after canal plugging

To determine whether the COR compensates for the loss of aVOR gain, independent of species, we studied cynomolgus and rhesus monkeys in which all six semicircular canals were plugged. Gains and phases of the aVOR and COR were determined at frequencies ranging from 0.02 to 6 Hz and fit with model-based transfer functions. Following canal plugging in a rhesus monkey, the acute stage aVOR gain was small and there were absent responses to thrusts of yaw rotation. In the chronic state, aVOR behavior was characterized by a cupula/endolymph time constant of ≈ 0.07 s, responding only to high frequencies of head rotation. COR gains were ≈ 0 before surgery but increased to ≈ 0.15 at low frequencies just after surgery; the COR gains increased to ≈ 0.4 over the next 12 weeks. Nine weeks after surgery, the summated aVOR + COR responses compensated for head velocity in space in the 0.5-3 Hz frequency range. The gains and phases continued to improve until the 35th week, where the combined aVOR + COR stabilized with gains of ≈ 0.5-0.6 and the phases were compensatory over all frequencies. Two cynomolgus monkeys operated 3-12 years earlier had similar frequency characteristics of the aVOR and COR. The combined aVOR + COR gains were ≈ 0.4-0.8 with compensatory phases. To achieve gains close to 1.0, other mechanisms may contribute to gaze compensation, especially with the head free. Thus, while there are individual variations in the time of adaptation of the gain and phase parameters, the essential functional organization of the adaption to vestibular lesions is uniform across these species.

Abstract P4-06-12: The Urokinase-Type Plasminogen Activator Is a Direct JAG1- Mediated Notch Target in Breast Cancer

Aberrant activation of the Notch signaling system and over-expression of the Notch ligand JAG1 are associated with poor outcome in breast cancer. The plasminogen activator system, which includes urokinase-type plasminogen activator (uPA), has been validated as a marker of recurrence, high metastasis risk and death in breast malignancy. By using microarray profiling of breast cancer cell lines that had undergone siRNA-mediated abrogation of Notch signaling we uncovered a link between activated Notch and uPA expression. An association between elevated expression of the Notch ligand JAG1, uPA and the basal breast cancer subtype was confirmed in breast cancer cell lines. The association between JAG1 and uPA expression persisted in a survey of primary carcinomas of the breast. We found that Notch knockdown reduced transcription of uPA and phenocopied uPA knockdown in breast cancer cells. Through mutational analysis we identified a CBF-1 binding site in the uPA promoter that is required for direct transcriptional regulation by Notch. These data suggest that JAG1-induced Notch activation results in breast cancer progression through up-regulation of the plasminogen activator system and directly links these two poor prognosis pathways.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-06-12.

Sturge-Weber syndrome: ear, nose, and throat issues and neurologic status

The pathophysiology of Sturge-Weber syndrome is poorly understood, and ear, nose, and throat involvement is possible. These issues can result in frequent illnesses or airway obstruction, affecting patients' neurologic status. Patients with definite brain involvement who reported potential ear, nose, and throat issues on intake questionnaires underwent retrospective reviews of their medical records. We examined the relationships between these issues, secondary surgical interventions, and patients' neurologic status. The most common complaints involved the sinuses and frequent ear infections. Six patients underwent placement of ear tubes, leading to improvements in migraines and stroke-like episodes in one patient, and improved seizure control in four others. Obstructive sleep apnea was confirmed in three patients who underwent sleep studies. Tonsil or adenoid removal occurred in another three patients. Surgery resulted in marked improvements regarding excessive drooling, daytime sleepiness, and breathing problems. These findings suggest that ear, nose, and throat problems occur frequently in patients with Sturge-Weber Syndrome, and when repeated ear infections are associated with uncontrolled seizures, early placement of ear tubes may be beneficial. Furthermore, patients with facial tissue hypertrophy may be at risk for obstructive sleep apnea, and should be appropriately evaluated.

INTRACELLULAR OXIDATION-REDUCTION STUDIES : I. REDUCTION POTENTIALS OF AMOEBA DUBIA BY MICRO INJECTION OF INDICATORS

Twenty-five oxidation-reduction indicators were injected in oxidized or reduced form into Amoeba dubia and Amœba proteus under controlled conditions of oxygen access. (1) Under anaerobiosis the ameba was able to reduce completely all the reversible oxidation-reduction indicators down to and including indigo disulfonate. (2) Under anaerobiosis the ameba was unable to reoxidize six of the most easily oxidizable indicators. (3) Under aerobiosis the ameba was able to reduce completely all the indicators down to and including 1-naphthol-2-sulfonate indo-2, 6-dichlorophenol. Toluylene blue, methylene blue and indigo tetrasulfonate were sometimes completely and sometimes only partly reduced, depending on the quantity of indicator injected and the duration of observation. (4) The time of reduction varied approximately with the size of the injection. Reduction was more rapid under anaerobiosis than under aerobiosis, more rapid in active than in sluggish cells and was retarded by toxic compounds. (5) Sulfonated compounds were somewhat toxic, as a rule. In interpreting reduction phenomena of micro injection, it is necessary to take into consideration the intensity, capacity and rate factors. It then becomes apparent that the ameba has a high reducing potential lying on the rH scale below the zone of indigo disulfonate. The reducing capacity of the ameba seems to be relatively great in the region of the simple indophenols and of a progressively diminishing magnitude as the zone of the indigos is approached. Material of high reduction potential appears to be generated within the ameba at a measurable rate. These phenomena, observed in the interior of the cell with the aid of indicators, parallel very closely those found in reduction electrode studies on bacterial cultures.

Critical Care staffs' attitudes, confidence levels and educational needs correlate with countries' donation rates: data from the Donor Action database

To investigate on the impact of Critical Care (CC) staffs' attitudes to donation, their acceptance of the brain death (BD) concept, their confidence with donation-related tasks and educational needs on national donation rates. Donor Action (DA) Hospital Attitude Survey (HAS) data were collected from 19 537 CC staff in 11 countries, including personal attitudes to donation, self-reported knowledge, involvement and comfort levels with donation-related tasks and educational requirements. Countries' donation performance was expressed as Procurement Efficiency Index (PEI) (organs procured and transplanted/deaths from eligible causes). National PEI rates correlated well with CC staffs' average support to donation (R = 0.700, P = 0.014), acceptance of the BD concept (R = 0.742, P = 0.007), confidence levels (R = 0.796, P = 0.002) and average educational requirements with donation-related tasks (R = -0.661, P = 0.025). Nurses reported significantly lower positive attitudes (P < 0.0001), acceptance of the BD concept (P < 0.0001), comfort levels (P < 0.0001) and requested more education (P = 0.0025) than medical staff members. DA's HAS is a powerful, standardized tool to assess CC staffs' attitudes and donation-related skills in different environments. Measures to improve countries' donation performance should focus on guidance and education of CC staff so as to ensure that all practitioners have sufficient knowledge and feel comfortable with donation-related issues.