Millimeter wave silicon micromachined waveguide probe as an aid for skin diagnosis--results of measurements on phantom material with varied water content

BACKGROUND

More than 2 million cases of skin cancer are diagnosed annually in the United States, which makes it the most common form of cancer in that country. Early detection of cancer usually results in less extensive treatment and better outcome for the patient. Millimeter wave silicon micromachined waveguide probe is foreseen as an aid for skin diagnosis, which is currently based on visual inspection followed by biopsy, in cases where the macroscopical picture raises suspicion of malignancy.

AIMS

Demonstration of the discrimination potential of tissues of different water content using a novel micromachined silicon waveguide probe. Secondarily, the silicon probe miniaturization till an inspection area of 600 × 200 μm2, representing a drastic reduction by 96.3% of the probing area, in comparison with a conventional WR-10 waveguide. The high planar resolution is required for histology and early-state skin-cancer detection.

MATERIAL AND METHODS

To evaluate the probe three phantoms with different water contents, i.e. 50%, 75% and 95%, mimicking dielectric properties of human skin were characterized in the frequency range of 95-105 GHz. The complex permittivity values of the skin are obtained from the variation in frequency and amplitude of the reflection coefficient (S11), measured with a Vector Network Analyzer (VNA), by comparison with finite elements simulations of the measurement set-up, using the commercially available software, HFSS. The expected frequency variation is calculated with HFSS and is based on extrapolated complex permittivities, using one relaxation Debye model from permittivity measurements obtained using the Agilent probe.

RESULTS

Millimeter wave reflection measurements were performed using the probe in the frequency range of 95-105 GHz with three phantoms materials and air. Intermediate measurement results are in good agreement with HFSS simulations, based on the extrapolated complex permittivity. The resonance frequency lowers, from the idle situation when it is probing air, respectively by 0.7, 1.2 and 4.26 GHz when a phantom material of 50%, 75% and 95% water content is measured.

DISCUSSION

The results of the measurements in our laboratory set-up with three different phantoms indicate that the probe may be able to discriminate between normal and pathological skin tissue, improving the spatial resolution in histology and on skin measurements, due to the highly reduced area of probing.

CONCLUSION

The probe has the potential to discriminate between normal and pathological skin tissue. Further, improved information, compared to the optical histological inspection can be obtained, i.e. the complex permittivity characterization is obtained with a high resolution, due to the highly reduced measurement area of the probe tip.

A randomised study of intranasal dexmedetomidine and oral ketamine for premedication in children

We studied the effects of intranasal dexmedetomidine combined with oral ketamine for premedication in children. One hundred and sixty children aged between 2 and 6 years were randomly allocated to one of four groups: 1 μg.kg(-1) intranasal dexmedetomidine with 3 mg.kg(-1) oral ketamine (Group 1); 1 μg.kg(-1) intranasal dexmedetomidine with 5 mg.kg(-1) oral ketamine (Group 2); 2 μg.kg(-1) intranasal dexmedetomidine with 3 mg.kg(-1) oral ketamine (Group 3); and 2 μg.kg(-1) intranasal dexmedetomidine with 5 mg.kg(-1) oral ketamine (Group 4). Sedation levels 10, 20 and 30 min after premedication were evaluated using a 5-point sedation scale. A 4-point emotional state score was used to evaluate patients when they were separated from their parents and their response to intravenous cannulation or facemask application. Approximately 90% of patients readily accepted premedication and onset times of acceptable sedation were similar in all four groups. Patients in Group 4 were significantly more sedated than those in Group 1 after 30 min (p = 0.036). A significantly higher proportion of patients in Group 3 (84%) and Group 4 (87%) accepted intravenous cannulation compared with those in Group 1 (40%) and Group 2 (54%) (p = 0.001). We conclude that the administration of 2 μg.kg(-1) intranasal dexmedetomidine and 3 mg.kg(-1) oral ketamine was the optimal combination, with children being easily separated from their parent, accepting intravenous cannulation and without causing excessive side-effects or postoperative complications.

A synthetic oxygen carrier in fibrin matrices promotes sciatic nerve regeneration in rats

Tissue-engineering nerve conduits have been studied for a long time in bridging large nerve defects. However, the low oxygen availability within the nerve conduits, which results in death of migratory Schwann cells (SC) or loss of the newly formed tissue's function, is still an obstacle for axonal regeneration. Thus, it was hypothesized that an oxygen-enriched conduit would enhance axonal regeneration and functional recovery in vivo. To address this issue, perfluorotributylamine (PFTBA) enriched fibrin hydrogel was prepared and injected into collagen-chitosan conduits. The conduit containing PFTBA-enriched fibrin hydrogel was then used to bridge a 12-mm sciatic nerve defect in rats. The control rats were bridged with collagen-chitosan conduits filled with fibrin matrices without PFTBA. It was found that axonal regeneration and functional recovery in the combined PFTBA group were significantly higher than those in the control group without PFTBA. Further investigations showed that the mRNA and protein levels of S-100, brain-derived neurotrophic factor and nerve growth factor were enhanced by PFTBA at 1 and 3weeks after surgery. However, the mRNA and protein levels of vascular endothelial growth factor were in a similar range between the combined PFTBA group and the control group without PFTBA. In addition, immunohistochemical results showed that the morphological appearances of regenerated nerve and survival of SC were enhanced by PFTBA at 4 and 12weeks after surgery. In conclusion, PFTBA-enriched nerve conduit is capable of enhancing axonal regeneration, which provides a new avenue for achieving better functional recovery in the treatment of nerve defect.

Remote ischemic preconditioning improves spatial learning and memory ability after focal cerebral ischemia-reperfusion in rats

OBJECTIVE

Using a rodent model of middle cerebral artery occlusion (MCAO), we investigated the effect of remote ischemic preconditioning (RIPC) on spatial learning and memory ability after focal cerebral ischemia-reperfusion (I/R).

METHOD

Thirty-six male Sprague-Dawley rats were randomly allocated into 3 groups (n=12, each): sham group, rats were subjected to sham operations without MCAO and RIPC; I/R group, rats were subjected to 1h of MCAO followed by 3 days of reperfusion; I/R+RIPC group, rats were subjected to RIPC and 1h MCAO followed by 3 days of reperfusion. The spatial learning and memory ability of the rats was measured by the Morris water maze task.The activity of cholineacetyltransferase (ChAT) in the hippocampus CA1 region was observed by an immunohistochemistry method.

RESULTS

In the Morris water maze task, MCAO elicited a significant decrease of the ability of spatial learning and memory in contrast to the sham group. Meanwhile, RIPC induced a significantly shorter prolongation of the escape latency (p<0.05); greater number passing through the platform (p<0.05) and less time for exploring the target quadrant (p<0.05) as compared with values for the I/R group. Furthermore, the number of ChAT positive cells in the CA1 region in the I/R+RIPC group was strikingly more than those of the I/R group (p<0.05).

CONCLUSIONS

RIPC could improve the ability of spatial learning and memory after focal cerebral ischemia-reperfusion probably due to its protection of the cholinergic neurons in the hippocampal CA1 region.

Histological improvement of long-term antiviral therapy in chronic hepatitis B patients with persistently normal alanine aminotransferase levels

The aim of this study was to evaluate the histological outcomes of chronic hepatitis B (CHB) patients with persistently normal alanine aminotransferase (ALT) levels after long-term antiviral therapy. Paired liver biopsies before and after lamivudine (LAM) treatment in CHB patients with normal and elevated ALT levels were compared. Histological response was defined as a 1-point decrease according to the Scheuer scoring system, without worsening of fibrosis between pretreatment and posttreatment biopsies. Among the 48 patients who underwent paired liver biopsies, 17 had persistently normal baseline ALT level and 31 had elevated ALT level. The median age of the patients was 44 years and 72.9% of the patients were male. The median duration of antiviral treatment was 44.5 months (range 14-104). Long-term follow-up of liver biopsies revealed that 82.4% of patients in the normal ALT group and 61.3% in the elevated ALT group had a baseline fibrosis score of 4, which was reduced to 17.6% and 38.7% after long-term therapy, respectively, indicating reversal of cirrhosis in a large proportion of both groups, especially in patients with normal baseline ALT levels. Long-term antiviral treatment could achieve significant histological improvement in CHB patients with fibrosis or cirrhosis, regardless of ALT level.

Imiquimod 5% cream versus timolol 0.5% ophthalmic solution for treating superficial proliferating infantile haemangiomas: a retrospective study

BACKGROUND

Infantile haemangiomas (IHs) are the most common vascular tumours of infancy. Topical therapies are a possible treatment for superficial IHs.

AIM

To determine the efficacy and safety of topical therapy in the treatment of superficial proliferating IHs.

METHODS

The medical records of all the patients with proliferating superficial IHs were reviewed. All lesions had been treated either with imiquimod 5% cream or timolol 0.5% ophthalmic solution. Lesions were classified into pairs, with one of each treatment in each pair, matched by anatomical location, colour and size. A visual analogue scale (VAS) and the Haemangioma Activity Score (HAS) were used to evaluate the efficacy of the two drugs. The paired Student t-test was used to test for differences in recovery with these two treatments.

RESULTS

In total, 51 patients treated with timolol and 94 treated with imiquimod met the inclusion criteria, and 20 lesions treated with timolol were successfully matched to a lesion treated with imiquimod. The paired t-test indicated that there was no significant difference in either VAS score (P = 0.11) or HAS (P = 0.49). For the imiquimod-treated patients, crusting was the most common reaction (65.0%, 13/20). This did not cause any superficial scarring or skin pigmentation in the matched pairs; however, superficial scars (14.9%, 14/94) and skin pigmentation disorders (28.7%, 27/94) were reported for some of the unmatched cases. There were no adverse events (AEs) during the treatment with timolol.

CONCLUSIONS

Both imiquimod 5% cream or timolol 0.5% ophthalmic solution showed equivalent clinical efficacy after 4 months of treatment. Timolol appeared to have fewer AEs than imiquimod in the management of superficial IHs. Larger, prospective controlled trials with long-term treatment are needed to confirm these results.

Quantitative assessment of brain microvascular and tissue oxygenation during cardiac arrest and resuscitation in pigs

Cardiac arrest is associated with a very high rate of mortality, in part due to inadequate tissue perfusion during attempts at resuscitation. Parameters such as mean arterial pressure and end-tidal carbon dioxide may not accurately reflect adequacy of tissue perfusion during cardiac resuscitation. We hypothesised that quantitative measurements of tissue oxygen tension would more accurately reflect adequacy of tissue perfusion during experimental cardiac arrest. Using oxygen-dependent quenching of phosphorescence, we made measurements of oxygen in the microcirculation and in the interstitial space of the brain and muscle in a porcine model of ventricular fibrillation and cardiopulmonary resuscitation. Measurements were performed at baseline, during untreated ventricular fibrillation, during resuscitation and after return of spontaneous circulation. After achieving stable baseline brain tissue oxygen tension, as measured using an Oxyphor G4-based phosphorescent microsensor, ventricular fibrillation resulted in an immediate reduction in all measured parameters. During cardiopulmonary resuscitation, brain oxygen tension remained unchanged. After the return of spontaneous circulation, all measured parameters including brain oxygen tension recovered to baseline levels. Muscle tissue oxygen tension followed a similar trend as the brain, but with slower response times. We conclude that measurements of brain tissue oxygen tension, which more accurately reflect adequacy of tissue perfusion during cardiac arrest and resuscitation, may contribute to the development of new strategies to optimise perfusion during cardiac resuscitation and improve patient outcomes after cardiac arrest.

A functional variant in IL12B promoter modulates its expression and associates with increased risk of allergic asthma

The interleukin-12B (IL12B) gene encodes the p40 chain of IL-12, a pro-inflammatory cytokine that antagonizes Th2 phenotype and, hence, may have a critical role in the pathogenesis of allergic asthma. In this report, we describe the identification of a novel IL12B promoter polymorphism (T-to-A exchange) at position -536. The IL12B -536AA genotype was significantly associated with asthma in the Chinese populations (P=0.011, odds ratio=2.227). The risk-associated A allele was linked to reduced expression of IL12B mRNA levels and IL12B production in asthmatic patients. Luciferase reporter assay provided evidence that risk-associated A allele reduced the promoter activity of IL12B gene compared with those of the promoter containing the protective T allele. We further observed that decreasing binding effects between the risk alleles A of IL12B and CCAAT/enhancer binding protein alpha (C/EBPα) through A allele sequence mediated streptavidin-conjugated agarose pulldown and biotin-labelled A allele mediated electrophoretic mobility shift assay. We also observed additive effects of the risk alleles of IL12B and decreased mRNA levels of C/EBPα in asthmatic patients. Therefore, we postulated that the presence of -536A allele in IL12B promoter could predispose to the development of allergic asthma.

The p53-Bak apoptotic signaling axis plays an essential role in regulating differentiation of the ocular lens

The tumor suppressor p53 is a master regulator of apoptosis and also plays a key role in cell cycle checking. In our previous studies, we demonstrated that p53 directly regulates Bak in mouse JB6 cells (Qin et al. 2008. Cancer Research. 68(11):4150) and that p53-Bak signaling axis plays an important role in mediating EGCG-induced apoptosis. Here, we demonstrate that the same p53-Bak apoptotic signaling axis executes an essential role in regulating lens cell differentiation. First, during mouse lens development, p53 is expressed and differentially phosphorylated at different residues. Associated with p53 expression, Bak is also significantly expressed during mouse lens development. Second, human p53 directly regulates Bak promoter and Bak expression in p53 knockout mice (p53-/-) was significantly downregulated. Third, during in vitro bFGF-induced lens cell differentiation, knockdown of p53 or Bak leads to significant inhibition of lens cell differentiation. Fourth, besides the major distribution of Bak in cytoplasm, it is also localized in the nucleus in normal lens or bFGF-induced differentiating lens cells. Finally, p53 and Bak are co-localized in both cytoplasm and nucleus, and their interaction regulates the stability of p53. Together, these results demonstrate for the first time that the p53-Bak apoptotic signaling axis plays an essential role in regulating lens differentiation.

The PP2A-Aβ gene is regulated by multiple transcriptional factors including Ets-1, SP1/SP3, and RXRα/β

Protein phosphatase-2A (PP-2A) is a major serine/threonine phosphatase abundantly expressed in eukaryotes. PP-2A is a heterotrimer that contains a 65 kD scaffold A subunit, a 36 kD catalytic C subunit, and a regulatory B subunit of variable isoforms ranging from 54-130 kDs. The scaffold subunits, PP2A-Aα/β, act as platforms for both the C and B subunits to bind, and thus are key structural components for PP-2A activity. Mutations in both genes encoding PP2A-Aα and PP2A-Aβ lead to carcinogenesis and likely other human diseases. Our previous work showed that the gene coding for PP2A-Aα is positively regulated by multiple transcription factors including Ets-1, CREB, and AP-2α but negatively regulated by SP-1/SP-3. In the present study, we have functionally dissected the promoter of the mouse PP2A-Aβ gene. Our results demonstrate that three major cis-elements, including the binding sites for Ets-1, SP1/SP3, and RXRα/β, are present in the proximal promoter of the mouse PP2A-Aβ gene. Gel mobility shifting assays reveal that Ets-1, SP1/SP3, and RXRα/β all bind to PP2A-Aβ gene promoter. In vitro mutagenesis and reporter gene activity assays demonstrate that while Ets-1 displays negative regulation, SP1/SP3 and RXRα/β positively regulate the promoter of the PP2A-Aβ gene. Co-expression of the cDNAs encoding Ets-1, SP1/SP3, or RXRα/β and the luciferase reporter gene driven by PP2A-Aβ promoter further confirm their control over the PP2A-Aβ promoter. Finally, ChIP assays demonstrate that Ets-1, SP1/SP3, and RXRα/β can all bind to the PP2A-Aβ gene promoter. Together, our results reveal that multiple transcription factors regulate the PP2A-Aβ gene. Moreover, our results provide important information explaining why PP2A-Aα and PP2A-Aβ display distinct expression levels.

Blind source separation in characterizing ECG pre-shock waveforms during Ventricular Fibrillation

Ventricular Fibrillation (VF) is a cardiac arrhythmia for which the only available treatment option is defibrillation by electrical shock. Existing literature indicates that VF could be the manifestation of different sources controlling the heart with different degrees of organization. In this work we test the hypothesis that the pre-shock waveforms of successful and unsuccessful shock outcomes could be related to the number of independent sources present in these waveforms. The proposed method uses Blind Source Separation (BSS) to extract independent components in frequency direction from a pig database consisting of 20 pre-shock waveforms. The slope of the energy capture curve was used as an indicator to demonstrate the number of independent sources required to model the pre-shock waveforms. The results were also quantified by performing a linear discriminant analysis based classification achieving an overall classification accuracy of 75%. The results indicate that successful cases can be modeled with less number of independent sources compared to unsuccessful cases.

Abstract P6-11-01: Intermittent High Dose Proton Pump Inhibitor Improves Progression Free Survival as Compared to Standard Chemotherapy in the First Line Treatment of Patients with Metastatic Breast Cancer

Purpose: High dose proton pump inhibitor (PPI) has proved to be potentially effective when combined with chemotherapy in preclinical data. This study (NCT01069081) was designed to investigate whether the efficacy of chemotherapy could be improved with the addition of proton pump inhibitor (PPI) in patients with metastatic breast cancer.

Patients and Methods: Females elder than 18 years old with histologically confirmed metastatic breast cancer were eligible for participation. Patients enrolled were randomly assigned to three arms: Arm A, docetaxol 75 mg/m2 on d4, followed by cisplatin 75 mg/m2 on d4, repeated every 21 days until maxinum 6 cycles or presence of disease progression or intolerable toxicity; Arm B, the same chemotherapy plus esomeprazole 80 mg p.o. bid three days on and the subsequent four days off, beginning on d1 repeated weekly up to disease progression, intolerable toxicity, patient's withdrawal, or a maximum of 66 weeks; Arm C, the same as Arm B with the only difference being dose of esomeprazole at 100 mg p.o. bid. The primary endpoint was progression free survival (PFS), and the secondary endpoints were time to progression (TTP), objective response rate (ORR), safety profile, and overall survival (OS).

Results: From Aug. 2009 to Dec. 2011, 100 women signed informed consent form (ICF) and 94 patients have undergone at least one injection of chemotherapy. Three patients had severe hypersensitivity reactions, two occurring after the first injection of docetaxol and one in the second cycle. After a median follow up of 17 months, 68 (72.3%) patients got disease progression and 23 (24.5%) patients died. Median PFS for the whole group (n = 94), arm A (n = 33), arm B (n = 30), arm C (n = 31) were 8.9, 7.5, 10.9, and 9.5 months, respectively (p = 0.082). A significant difference was observed between patients who had taken PPI and who not with median PFS of 9.5 and 7.5 months, respectively (p = 0.030). Among 17 patients with triple negative breast cancer, this difference was bigger with median PFS of 9.5 and 3.3 months, respectively (p = 0.014). The overall response rates for the whole group, arm A, arm B, arm C were 58.5%, 51.5%, 63.3%, 61.3%, respectively.

Conclusion: This trial is the first randomized study to demonstrate antitumor effects of intermittent high dose PPI in patients with metastatic breast cancer. Docetaxel and cisplatin doublet is comparable to the other first-line chemotherapeutical regimens and the addition of proton pump inhibitor to the doublet improves efficacy with no adding toxicity, especially in patients with triple negative breast cancer.

Key Words Proton Pump Inhibitor (PPI), Triple Negative Breast Cancer (TNBC), Phase II Study, Metastatic Breast Cancer, Chemotherapy

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-11-01.