Use of MMTV-Neu/P53 KO Transgenic Mice To Screen for Potential Chemopreventive Agents

The MMTV-Neu transgenic model of mammary cancer was developed almost 20 years ago in which the mice develop Neu over-expressing ER- mammary cancers. Since human ER- Neu over-expressing mammary cancers often also have mutations in P53, a heterozygous KO of P53 was incorporated into the model. We used this model to examine a wide variety of potential chemopreventive agents. The agents were administered to virgin female MMTV-Neu/P53 KO mice beginning when they were 60 days of age. Initiation of treatment with the agents was later than that typically employed by other investigators (e.g., 35 days of age). Mice were monitored until 360 days of age. In agreement with Brown and colleagues (e.g., Cancer Research 62, 6376-6380, 2002), it was found that both RXR agonists (Targretin, UAB-30) and EGFR 1 and/or 2 inhibitors (Tarceva, Lapatinib) were highly effective in preventing the development of these cancers. We also observed that a wide variety of agents were ineffective; including Atorvastatin, rosiglitazone (a PPAR gamma agonist), SAHA (an HDAC inhibitor), and a soy isoflavones mixture. In separate studies, mice bearing small palpable mammary tumors were treated for five days with these various agents, and examined for alterations in potential biomarkers; including proliferation. As previously shown by our lab in an ER+ rat model of mammary cancer, effective agents (e.g., Iressa and Targretin) strongly inhibited cancer cell proliferation, whereas ineffective agents failed to significantly inhibit proliferation. Thus, such a short-term assay might be employed to predict potential chemopreventive compounds. Short-term treatment with the EGFR inhibitors also decreased levels of expression of phosphorylated EGFR and downstream proteins; e.g., AKT/ERK. Thus, this model is useful in identifying agents that will prevent the development of human breast cancers that over-express Neu. This is important since Neu over-expressing ER- cancers have a relatively poor prognosis, and Neu over-expressing ER+ tumors are relatively unresponsive to standard hormonal therapies (e.g., tamoxifen and aromatase inhibitors). Supported by NCI contract HHSN261200433001C.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1042.

A simple mathematical approach to deciding the dosage of vaccine against pandemic H1N1 influenza

Results from early clinical trials have shown that a single dose of pandemic H1N1 influenza vaccine may generate sufficient antibody response, but the relevance of this fact to public health decision making has yet to be clarified. The present study compares the risk of clinical attack (i.e. clinical attack rate) between one- and two-dose vaccination schemes. If the efficacies do not greatly vary between one- and two -dose schemes, one-dose vaccination may well be supported. Nevertheless, two-dose vaccination is shown to result in less morbidity if the vaccine efficacies are greatly diminished by reducing the dose. As long as the detailed efficacy estimates rest on theoretical assumptions, single-dose vaccination may only be sufficiently justified in a specific setting where the number of vaccines is extremely limited.

Tumour oxygenation is increased by hyperthermia at mild temperatures. 1996

The effects of hyperthermia on the oxygenation status in R3230 AC tumours of Fischer rats were measured using a polarographic oxygen electrode system. The median pO(2) in about 10 mm diameter tumours grown s.c. in the leg of rats was 3.7 +/- 0.3 mm Hg and it significantly increased upon heating at modest temperatures. For example, the tumour pO(2) measured within 10-15 min after heating for 30 min at 42.5 degrees C was about three-fold greater than that in the control tumours. About 62% of pO(2) values measured in control tumours were <5 mm Hg. After heating at 42.5 degrees C for 30 min, 37% of pO(2) values were <5 mm Hg. Such an increase in tumour oxygenation or reoxygenation of hypoxic cells appeared to result from an increase in tumour blood flow caused by the mild temperature hyperthermia. The presence of hypoxic cells in tumours is believed to be a major factor in limiting the effectiveness of radiotherapy, certain chemotherapy drugs and phototherapy. Hyperthermia at mild temperatures easily achievable with the use of presently available clinical hyperthermia devices may be an effective means to overcome the hypoxic protection in the treatment of human tumours.

Characteristic Genotypes of Vascular Endothelial Growth Factor are Susceptible to Ascites in Patients with Cirrhosis

This study was designed to investigate whether different vascular endothelial growth factor (VEGF) genotypes are associated with ascites formation in cirrhotic patients. Seventy cirrhotic patients were included in the study: 25 cirrhotic patients with ascites and 45 cirrhotic patients without ascites. Patient characteristics were investigated and compared between the two groups. With regard to VEGF genotype, 42 patients were C/C and 28 patients were T/T or C/T. The genotypes T/T or C/T were observed in 23 cases (51%) among the non-ascites group, but in only five cases (20%) among the ascites group. Serum levels of albumin and creatinine, and the VEGF genotypes were significantly different between the two groups. Multiple regression analysis showed that serum levels of creatinine and the VEGF genotypes were significantly correlated with ascites formation. Thus, it can be concluded that VEGF genotyping might be a valuable susceptibility marker for ascites formation in cirrhotic patients.

Comparative analysis of putative periodontopathic bacteria by multiplex polymerase chain reaction

BACKGROUND AND OBJECTIVE

The polymerase chain reaction (PCR) has been applied for the rapid and specific detection of periodontopathic bacteria in subgingival plaque and is potentially of clinical benefit in the diagnosis and treatment of periodontitis subjects. However, several technical points need to be modified before the conventional PCR detection system can be used by clinicians.

MATERIAL AND METHODS

To develop a PCR-based technique more applicable for clinical use than conventional PCR, we established a multiplex PCR for five putative periodontopathic (Treponema denticola, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia and Tannerella forsythia) and two nonperiodontopathic (Streptococcus sanguinis and Streptococcus salivarius) species of bacteria using whole-plaque suspension as templates, and detected bacteria in subgingival plaque taken from 85 subjects at the supportive periodontal therapy stage after active periodontal treatments.

RESULTS

Among putative periodontopathic bacteria, the detection frequency of T. denticola and P. gingivalis was elevated in parallel with higher probing pocket depth and clinical attachment loss, and had 4.2-14.1 times increasing odds of the clinical parameters tested. Detection of any of the five species of putative periodontopathic bacteria markedly increased the odds ratio of a higher probing pocket depth, clinical attachment loss and bleeding on probing.

CONCLUSION

The multiplex PCR system developed in this study enabled the detection of all the bacteria under investigation in one reaction tube in a less time- and labor-intensive manner than conventional PCR. These results support the potential clinical use of multiplex PCR for detecting periodontopathic bacteria and for evaluating therapeutic strategies and predicting the prognosis for each subject.

Oestrogen-dependent stimulation of luteinising hormone release by galanin-like peptide in female rats

Galanin-like peptide (GALP), a ligand for three types of galanin receptor, is reported to have a role in regulating luteinising hormone (LH) release in male rodents and primates, but its role in LH release in female rodents remains controversial. The present study was conducted to test whether GALP has a stimulatory role in regulating LH secretion in female rats. The effect of i.c.v. infusion of GALP (5 nmol) on pulsatile LH release was investigated in Wistar-Imamichi strain female rats, or lean and obese Zucker rats. In oestradiol-17beta (oestradiol)-primed ovariectomised (OVX) Wistar-Imamichi female rats, i.c.v. infusion of GALP caused a gradual increase in LH release for the first 1.5 h after the infusion followed by an increased LH pulse frequency during the next 1.5 h, resulting in a significant increase in the mean LH concentrations and baseline levels of LH pulses throughout the sampling period and in the frequency of LH pulses at the last half of the period compared to vehicle-treated controls. The stimulatory effect of GALP was oestrogen-dependent because the same GALP treatment did not affect LH release in OVX rats in the absence of oestradiol. In lean Zucker rats, LH pulses were found in oestradiol-primed OVX individuals and central GALP infusion increased mean LH concentrations in the last half of the period. By contrast, few LH pulses were found in oestradiol-primed OVX obese Zucker rats reportedly with lower hypothalamic GALP expression. Central GALP infusion caused an apparent but transient increase in LH release, resulting in the significant increase in all pulse parameters of LH pulses compared to vehicle-treated controls in the first half of the sampling period. These results suggest that hypothalamic GALP is likely involved in stimulating GnRH/LH release, and that the stimulatory effect of GALP on LH release is oestrogen-dependent in female rats.

Pseudospin soliton in the nu=1 bilayer quantum Hall state

We investigate a domain structure of pseudospins, a soliton lattice in the bilayer quantum Hall state at total Landau level filling factor nu = 1, in a tilted magnetic field, where the pseudospin represents the layer degree of freedom. An anomalous peak in the magnetoresistance Rxx appears at the transition point between the commensurate and incommensurate phases. The Rxx at the peak is highly anisotropic for the angle between the in-plain magnetic field B parallel and the current, and indicates a formation of the soliton lattice aligned parallel to B parallel. The temperature dependence of the Rxx peak reveals that the dissipation is caused by thermal fluctuations of pseudospin solitons. We also study a phase diagram of the bilayer nu = 1 system, and the effects of density imbalance between the two layers.

Inhibition of metastin (kisspeptin-54)-GPR54 signaling in the arcuate nucleus-median eminence region during lactation in rats

Follicular development and ovulation are suppressed during lactation in various mammalian species, mainly due to the suppression of pulsatile GnRH/LH secretion. Metastin (kisspeptin-54), a KiSS-1 gene product, is an endogenous ligand for GPR54, a G-protein-coupled receptor, and suggested to play a critical role in regulating the gonadal axis. The present study therefore aims to determine whether metastin (kisspeptin-54)-GPR54 signaling in discrete brain areas is inhibited by the suckling stimulus that causes suppression of LH secretion in lactating rats. Quantitative RT-PCR revealed that the KiSS-1 mRNA level was significantly lower in the arcuate nucleus (ARC)-median eminence region in lactating ovariectomized (OVX) and estrogen-treated OVX rats than in nonlactating controls. KiSS-1 mRNA in the anteroventral periventricular nucleus was kept at a low level in both lactating and nonlactating rats despite estrogen treatment. GPR54 mRNA levels were significantly lower in lactating than nonlactating rats in the anteroventral periventricular nucleus, but the levels in lactating mothers of the preoptic area and ARC-median eminence were comparable with nonlactating controls. Although KiSS-1 mRNA-expressing cells or metastin (kisspeptin-54) immunoreactivities were densely located in the ARC of nonlactating controls, few were found in the ARC of lactating OVX animals. Various doses of metastin (kisspeptin-54) (0.02, 0.2, and 2 nmol) injected into the third ventricle caused a significant increase in LH secretion in both lactating and nonlactating OVX rats, suggesting that lactating rats are responsive to metastin (kisspeptin-54) stimulus. Thus, the present study demonstrated that KiSS-1 mRNA/metastin (kisspeptin-54) expression is inhibited in the ARC by the suckling stimulus, suggesting that the inhibition is most probably involved in suppressing LH secretion in lactating rats.

Tissue Doppler-derived index of left ventricular filling pressure, E/E', predicts survival of patients with non-valvular atrial fibrillation

OBJECTIVES

To investigate whether the ratio of early transmitral flow velocity (E) to early diastolic mitral annular velocity (E') predict prognosis in patients with non-valvular atrial fibrillation.

METHODS

230 patients with non-valvular atrial fibrillation were enrolled and studied. According to E/E' value, patients were divided into groups with lower (group A with E/E' <or= 15) and higher (group B with E/E' > 15) E/E'.

RESULTS

During follow up (average 245 days), 21 (9.1%) deaths were documented. All cause death (15/90 (16.7%) v 6/140 (4.3%)), cardiac death (10 (11.1%) v 2 (1.4%)) and congestive heart failure (16 (17.8%) v 8 (5.7%)) were more common in group B than in group A (all p < 0.01). A Kaplan-Meier survival curve showed that the cumulative survival rate was significantly lower in group B than in group A (log rank p = 0.0013). By multivariate logistic regression analysis, E/E' (chi(2) = 4.47, odds ratio (OR) 1.05, 95% confidence interval (CI) 1.01 to 1.11, p = 0.03) and age (chi(2) = 6.45, OR 1.06, 95% CI 1.01 to 1.11, p = 0.02) were independent predictors of mortality.

CONCLUSION

The Doppler-derived index of left ventricular filling pressure, E/E', is a powerful predictor of the clinical outcome of patients with non-valvular atrial fibrillation.

Fusing EEG and fMRI based on a bottom-up model: inferring activation and effective connectivity in neural masses

The elucidation of the complex machinery used by the human brain to segregate and integrate information while performing high cognitive functions is a subject of imminent future consequences. The most significant contributions to date in this field, known as cognitive neuroscience, have been achieved by using innovative neuroimaging techniques, such as electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI), which measure variations in both the time and the space of some interpretable physical magnitudes. Extraordinary maps of cerebral activation involving function-restricted brain areas, as well as graphs of the functional connectivity between them, have been obtained from EEG and fMRI data by solving some spatio-temporal inverse problems, which constitutes a top-down approach. However, in many cases, a natural bridge between these maps/graphs and the causal physiological processes is lacking, leading to some misunderstandings in their interpretation. Recent advances in the comprehension of the underlying physiological mechanisms associated with different cerebral scales have provided researchers with an excellent scenario to develop sophisticated biophysical models that permit an integration of these neuroimage modalities, which must share a common aetiology. This paper proposes a bottom-up approach, involving physiological parameters in a specific mesoscopic dynamic equations system. Further observation equations encapsulating the relationship between the mesostates and the EEG/fMRI data are obtained on the basis of the physical foundations of these techniques. A methodology for the estimation of parameters from fused EEG/fMRI data is also presented. In this context, the concepts of activation and effective connectivity are carefully revised. This new approach permits us to examine and discuss some future prospects for the integration of multimodal neuroimages.

High ambient ammonia promotes growth in a ureogenic goby, Mugilogobius abei

Mugilogobius abei has the ability to produce large amounts of urea when exposed to high ambient ammonia. Despite this metabolically costly approach, and reports of growth inhibition effects of ammonia on fish, M. abei exposed to ammonia shows no adverse effects on growth. To investigate this observation the growth of M. abei was measured at room temperatures for 8 weeks at a constant ration level under solitary and grouped conditions, in 20% SW with or without (control) 2 mM NH(4)Cl. Furthermore, pituitary mRNA levels of growth hormone, oxygen consumption, incorporation of external (15)N-ammonia into amino acid and protein fractions as well as behavioral activities were also examined. The specific growth rates of ammonia-exposed fish under grouped condition over the 8 weeks were significantly higher than those of control, while those rates under solitary condition were not significantly different between the treatments. The pituitary of ammonia-exposed fish had higher growth hormone mRNA than in control fish. The use of (15)N isotope revealed that M. abei can actively use external ammonia as a supplementary nitrogen source. Oxygen consumption of ammonia-exposed fish was significantly lower than that of control fish. Locomotor activity and aggressive behavior under grouped condition were significantly reduced in ammonia-exposed fish as compared to those of control. These combined alterations in the ammonia-exposed fish may result in the higher growth rates.

Clinical significance of alendronate in postmenopausal type 2 diabetes mellitus

OBJECTIVES

To examine early changes in biochemical markers of bone turnover and bone mineral density (BMD) in a clinical trial of anti-resorptive agent alendronate versus alfacalcidol in postmenopausal women with type 2 diabetes mellitus.

METHODS

12 subjects (mean age; 73.1 +/- 6.3 yrs, duration of diabetes; 13.2 +/- 3.7 yrs) were administered alendronate sodium (5 mg/day) and 12 subjects (mean age; 70.7 +/- 7.8 yrs, duration of diabetes; 12.8 +/- 2.0 yrs) were administered alfacalcidol (0.5 microg/day) for 12 months. Urinary N-telopeptide cross-linked collagen type I (NTx), one of biochemical markers, and radial bone mineral density (BMD) were measured as a marker of bone turnover.

RESULTS

After 12 months, urinary NTx did not change in women with alfacalcidol treatment, however urinary NTx significantly decreased after alendronate treatment. The BMD significantly decreased by 3.33% (p<0.05) in women with alfacalcidol treatment, while the BMD did not decrease in women with alendronate treatment.

CONCLUSION

Alendronate that produces reduction in urinary NTx and inhibition of decrease in BMD may have a clinical significance to reduce the risk of bone fracture in postmenopausal type 2 diabetic women.

Hard-food mastication suppresses complete Freund's adjuvant-induced nociception

The effect of food hardness during mastication on nociceptive transmission in the spinal cord was studied by analyzing complete Freund's adjuvant (CFA) induced nocifensive behavior and Fos expression. The behavioral study showed that the shortening of the withdrawal latency following CFA injection into the hind paw was depressed after a change in the given food hardness from soft to hard. The depression of nocifensive behavior in the rats with hard food was reversed after i.v. injection of naloxone. Fos protein-like immunoreactive cells (Fos protein-LI cells) were expressed in the superficial and deep laminae of the L4-6 spinal dorsal horn after s.c. injection of CFA into the hind paw during soft food mastication. The number of Fos protein-LI cells was decreased in the rats with hard food mastication followed by soft food. This reduction of Fos protein-LI cells following change in food hardness was reversed after i.v. application of naloxone. Furthermore, the depression of Fos protein-LI cells following hard food intake was significantly inhibited after bilateral inferior alveolar nerve transection or bilateral ablation of the somatosensory cortex. These findings suggest that the change in food hardness during mastication might drive an opioid descending system through the trigeminal sensory pathway and somatosensory cortex resulting in an antinociceptive effect on chronic pain. However, IAN transection and cortical ablation did not induce 100% reversal of Fos expression, suggesting other than trigeminal sensory system may be involved in this phenomena, such as the pathway through the brainstem reticular formation.

A new model of experimental parotitis in rats and its implication for trigeminal nociception

A rat model of chronic parotitis was developed following a direct injection of Complete Freund's adjuvant (CFA) into the unilateral parotid gland via the parotid duct without skin incision. The nocifensive behavior, plasma extravasation in the parotid gland, and trigeminal Fos protein expression, a marker of neuronal activation, were analyzed in this model and compared to that of the saline-injected rats. A significant reduction of the escape threshold to mechanical stimulation of the lateral face on the ipsilateral side to the CFA injection was observed at 1-6 days after CFA injection as compared to that of the pre-CFA control ( P<0.01). The lateral face region contralateral to the CFA injection also showed mechanical hyperalgesia at 1-6 days after injection ( P<0.05). The plasma extravasation was significantly increased in the parotid gland ipsilateral to CFA injection as compared to that of the parotid gland with saline injection at 3 days after injection as shown by Evans' blue dye extravasation ( P<0.05). Bilateral expression of Fos protein-like immunoreactive cells was observed in the transition zone between the trigeminal spinal nucleus interpolaris (Vi) and caudalis (Vc) and paratrigeminal nucleus (Pa5). On the other hand, a significant unilateral expression of Fos protein-positive cells was observed on the ipsilateral side of the upper cervical (C2) dorsal horn ( P<0.05). This model of parotitis can be used to study trigeminal pain mechanisms associated with sialadenitis. A unique feature of this preparation is that the inflammation was limited to the parotid gland after intraductal injection of CFA, allowing analysis of peripheral input from a defined orofacial region. The model will be useful in developing new strategies to treat chronic orofacial pain.