Selective vitamin D receptor modulators and their effects on colorectal tumor growth

The active form of vitamin D, 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)], is an endocrine hormone whose classic role is the maintenance of calcium homeostasis. It is well documented that 1,25(OH)(2)D(3) also has anti-tumor effects on a number of cancers and cancer cell lines including breast, colorectal, gastric, liver, ovarian, prostate, and non-melanoma skin cancers. Included in the anti-tumor activities of 1,25(OH)(2)D(3) are its ability to cause antiproliferation, prodifferentation and decrease angiogenesis. Furthermore, through regulation of the plaminogen activator (PA) system and a class of proteolytic enzymes called matrix metalloproteinases (MMPs), 1,25(OH)(2)D(3) reduces the invasive spread of tumor cells. Because of the calcemic limitations of using 1,25(OH)(2)D(3) as a therapy, we have tested the effects of a novel Gemini vitamin D analogue, Deuterated Gemini (DG), on mouse colorectal cancer. We demonstrated that DG is more potent in reducing tumor volume and mass, compared to control and 1,25(OH)(2)D(3). DG significantly prevented (100% reduction, p<0.05) the invasive spread of colorectal tumor cells into the surrounding muscle, and had no effect on serum calcium levels. Thus, DG acts as a selective vitamin D receptor modulator (SVDRM) by enhancing select anti-tumor characteristic 1,25(OH)(2)D(3) activities, without inducing hypercalcemia. Thus, DG shows promise in the development of colorectal cancer therapies.

Electron-ion-coincidence spectra of K-shell excited Ne, Ar, and Kr clusters

Electron-ion-coincidence spectra were recorded for K-shell excited krypton, argon, and neon clusters covering the size range from 1 atom to about 3000 atoms by utilizing hard x-ray undulator beamlines. Multiply charged ions Rz+(z>or=2) and singly charged ions Rn+(n>or=1) are observed as cluster fragments, and their relative abundance exhibits a characteristic dependence on the average cluster size N. It is expected from these results that the charges generated on the cluster surface are strongly localized while those in the cluster core are more delocalized. The estimated charge separation distance increases with N, and it is longer for lighter elements.

Coulomb explosion of K-shell ionized krypton clusters studied by multiple-ion coincidence momentum imaging

The Coulomb explosion of K-shell ionized krypton clusters with an average size N of 160 has been studied by electron-multiple-ion-coincidence measurements in which the time-of-flight (TOF) of ions was measured by using a position sensitive detector. The authors have sorted the TOF spectra by the number of coincidence ion signals, Ncoin, and found that singly charged fragment ions such as Kr+, Kr2+, and Kr3+ are dominant for Ncoin>or=2, and that multiply charged ions are detected mainly for Ncoin=1. The Ncoin dependence of the peak widths in the TOF spectra reveals that the average momentum of the Kr+ ions increases with Ncoin, while those of Kr2+ and Kr3+ decrease. These results have been more directly confirmed by the momentum imaging measurements. The authors propose that the heavier ions are produced in the central part of clusters where the Coulomb interactions from the surrounding ions are more effectively canceled out due to the higher symmetry.

G-protein beta-3 subunit C825T polymorphism, sodium and arterial blood pressure: a community-based study of Japanese men and women

Epidemiological evidence on gene-environment effects of the G-protein beta-3 subunit C825T polymorphisms and sodium on blood pressure in the free-living general population is limited. We examined the associations between the C825T polymorphism and blood pressure levels, stratified by the sodium variables estimated by 24-h urinary sodium excretion and a dietary questionnaire, among 1,471 men and women aged 30-74 from a community in Japan. Our a priori hypothesis was that individuals with the 825T allele have elevated blood pressure among subjects with a high sodium intake. Among the whole group, the systolic blood pressure level was +2.2 mmHg (p = 0.10) higher in TT than CC genotype individuals after adjustment for sex, age, antihypertensive medication use, body mass index, and alcohol consumption. This difference was more evident among individuals with low sodium excretion (+4.5 mmHg, p = 0.01), low present sodium intake (+3.2 mmHg, p = 0.11), and low past sodium intake (+4.8 mmHg, p = 0.02). No associations were observed among those with high sodium variables. Our results indicate that the G-protein beta-3 subunit C825T polymorphism is associated with higher systolic blood pressure levels in a large free-living Japanese population, and more specifically in women with a low sodium intake. This finding helps to explain part of the discrepancy between the previously reported genetic association among different ethnic groups.

Critical point dewetting observed in the liquid Se-Tl system on a quartz substrate

We have studied the wetting phenomena of the liquid Se-Tl system on a quartz substrate by photography and ellipsometry, and found that a thin layer of the Se-rich liquid phase intrudes between the Tl-rich liquid phase and the quartz substrate in the temperature region far below the critical temperature. Surprisingly, neither the Se-rich nor the Tl-rich wetting film is formed near the critical temperature, indicating the critical point dewetting. In addition, we found that the temperature difference between the surface and the bulk liquid induces the transition between the wetting and non-wetting states. In order to interpret the observation, we constructed a model grand potential, incorporating the long-range interaction, the temperature difference and gravity. From this analysis, it is suggested that the combination of the long-range force and gravity plays an important role in overcoming the critical point wetting phenomena.

Colon cancer and solar ultraviolet B radiation and prevention and treatment of colon cancer in mice with vitamin D and its Gemini analogs

It has been recognized that people who live at higher latitudes and who are vitamin D deficient are at higher risk of dying from many common cancers including colon cancer. To evaluate the role of vitamin D deficiency on colon tumor growth, Balb/c adult male mice were fed either a vitamin D sufficient or vitamin D deficient diet for 10 weeks. Mice were arranged into groups of six and each animal received subcutaneously 10(4) MC-26 cells in the posterior trunk. The tumor size was recorded daily. By day 9 there was a significant difference in tumor volume between the vitamin D sufficient and vitamin D deficient mice. By day 18 the vitamin D deficient animals had a tumor size that was 56% larger compared to the animals that were vitamin D sufficient. To determine whether treatment with active vitamin D analogs could further decrease colon tumor growth in a vitamin D sufficient state, groups of mice were treated with the novel 19-nor-Gemini compounds. The mice were fed a low calcium diet. Twenty-four hours after tumor implantation, the mice received, three times weekly, one of the vitamin D analogs or the vehicle. The group that received Gemini 1,25-dihydroxy-21(3-hydroxy-3-trifluoromethyl-4-trifluoro-butynyl)-19-nor-20S-cholecalciferol (3) showed a dose-dependent decrease in tumor volume. On day 19, at the dose level of 0.02microg molar equivalents (E), the tumor volume was reduced by 41% when compared to the control group. At the same time point, the hexadeuterated analog 1,25-dihydroxy-21(3-hydroxy-3-trifluoromethyl-4-trifluoro-butynyl)-26,27-hexadeutero-19-nor-20S-cholecalciferol (4), administered at the 10-fold lower dose of 0.002microgE, showed a 52% reduction in tumor volume (p<0.05), compared to the control group. Animals that received 1,25(OH)(2)D(3) at 0.002 and 0.02microg showed a trend in tumor volume reduction at the highest dose but the changes were not statistically significant. An evaluation of serum calcium concentrations revealed that the calcium levels were normal in all groups, except the group receiving 0.02microgE of 4. The results from these studies demonstrate that vitamin D deficiency may accelerate colon cancer growth and that novel Gemini analogs of 1,25(OH)(2)D(3) may be an effective new approach for colon cancer treatment.

Clinical significance of cytogenetics and interphase fluorescence in situ hybridization analysis in newly diagnosed multiple myeloma in Taiwan

BACKGROUND

The incidence of multiple myeloma (MM) is lower in Asia than in Western countries. However, it is not known whether cytogenetic abnormalities (CA) characteristic of MM in Asia differ from those documented in the West.

PATIENTS AND METHODS

We analyzed CA by conventional cytogenetics (CG) and/or fluorescence in situ hybridization (FISH), assessed their clinical significance in 150 Chinese MM patients and compared our data with that derived from Western countries.

RESULTS

CA were detected by CG (CG_CA) in 44 (29.3%) of the 150 patients and by FISH (FISH_CA) in 59 (67%) of the 88 patients studied. Presence of either CG_CA or FISH_CA was associated with a poor prognosis. Patients with CG_CA and hyperdiploid chromosomes, always associated with several trisomies, had a longer survival (median 25 months versus 12 months; P=0.025) in comparison with those with non-hyperdiploid chromosomes, usually associated with a monosomy 13/partial deletion of 13q (Delta13) and a rearrangement of 14q32. A novel recurrent CG_CA, add(19)(p13), was found in four patients: all males with immunoglobulin G/lambda isotypes, extramedullary myeloma at diagnosis and a poor prognosis. Three groups of patients with significantly different survival, CG_Delta13, FISH_Delta13 but without CG_Delta13, and neither CG_Delta13 nor FISH_Delta13 (median 9 versus 15 versus 32 months; P=0.013) were identified.

CONCLUSIONS

We conclude that MM CA in our patients are similar to those noted in Western countries, and that combined CG and FISH analysis can predict prognosis. The clinical significance of add(19)(p13) needs to be further investigated.

Non-steroidal anti-inflammatory drugs and colorectal cancer prevention

Colorectal cancer is the second leading cause of cancer deaths in the United States. Currently, the most effective strategy available for colon cancer prevention is endoscopic screening, with polypectomy or surgical resection for advanced lesions. This intervention carries with it many concerns regarding cost, patient acceptance, and the growing burden of surveillance colonoscopies for patients with polyps. Further improvements in the understanding of the multistep model of colorectal carcinogenesis will probably lead to the development of other primary and secondary prevention strategies. Data obtained from animal and epidemiological studies and most recently from randomised, placebo controlled trials, suggest that non-steroidal anti-inflammatory drugs may prove effective chemopreventive agents in different groups of people, from patients with familial adenomatous polyposis to those with sporadic adenomas.

Paclitaxel, carboplatin, and concomitant radiotherapy for resected patients with high risk head and neck cancer

Many resected patients with locally advanced head and neck cancer are found on pathological assessment to have high-risk features for recurrence. We thus performed a feasibility trial of post-operative radiotherapy with paclitaxel and carboplatin in high-risk carcinoma of the head and neck. All patients were planned for 6 cycles of weekly paclitaxel (40 mg/m2) and carboplatin (AUC=1) and concomitant radiotherapy, 60 Gy in 6 weeks. The most common side effect was grade 3 and 4 mucositis in 5/6 patients and g-tube placement in 4/6 patients. Five out of 6 patients remain alive without evidence of disease at a mean time of 19 months since completion of therapy. Our pilot study treated 6 postoperative patients. Since 4 of 6 enrolled patients were unable to complete the treatment as prescribed, we conclude that this regimen is not feasible. With an 83% grade 3 or 4 mucositis rate and 67% of patients enrolled requiring feeding tube placement, this regimen is not tolerable.

Induction of galanin receptor-1 (GalR1) expression in external granule cell layer of post-natal mouse cerebellum

Galanin is a modulator of fast transmission in adult brain and recent evidence suggests that it also acts as a trophic factor during neurogenesis and neural injury and repair. Previous studies in our laboratory have identified galanin mRNA in Purkinje cells of adult and developing rat (but not adult mouse) cerebellum; and galanin-binding sites in adult mouse (but not rat) cerebellum. The post-natal development of the cerebellum provides a unique and convenient model for the investigation of developmental processes and to learn more about putative cerebellar galanin systems, the current study examined the presence and distribution of galanin-like-immunoreactivity (- LI), [(125)I]-galanin binding sites and galanin receptor-1 (GalR1) mRNA in post-natal mouse cerebellum. Using autoradiography and in situ hybridization, [(125)I]-galanin binding sites and GalR1 mRNA were first detected on post-natal day 10 (P10) in the external germinal layer of all lobes and high levels were maintained until P14. Quantitative real-time PCR assays detected GalR1 mRNA in whole cerebellum across the post-natal period, with a strong induction and peak of expression at P10. Assessment of galanin levels in whole cerebellum by radioimmunoassay revealed relatively similar concentrations from P5 to P20 and in adult mice (80-170 pg/mg protein), with a significantly higher concentration (250 pg/mg, p < 0.01) detected at P3. These concentrations were some four- to six-fold lower than those in adult forebrain samples. Using immunohistochemistry, galanin-like-immuno-reactivity was observed in prominent fibrous elements within the white matter tracts of the cerebellum at P3-5 and in more punctate elements in the internal granule cell layer and associated with the Purkinje cell layer at P12 and P20. Increased levels of GalR1 mRNA and galanin binding (attributed to GalR1) in the external granule cell layer at P10-12/(14) coincide with granule cell migration from the external to the inner granule cell layer and together with demonstrated effects of other neuropeptide-receptor systems suggest a role for GalR1 signalling in regulating this or related developmental processes.

Chromosomal abnormalities of 200 Chinese patients with non-Hodgkin's lymphoma in Taiwan: with special reference to T-cell lymphoma

BACKGROUND

The distribution of the histopathological subtypes of non-Hodgkin's lymphoma (NHL) is different among various geographical areas. However, there are few reports concerning cytogenetic findings of NHL, especially T-cell lymphoma, in Asian people.

PATIENTS AND METHODS

We analyzed the chromosomal abnormalities of 200 adult patients with NHL in Taiwan and correlated the non-random aberrations with the histological subtypes.

RESULTS

One hundred and thirty-eight patients (69%) had B-cell lymphoma. The incidence of the t(14;18) in total lymphoma was lower in Taiwan (12%) than in the West (20-30%), but its incidence in follicular lymphoma was comparable between the two areas (17 of 28 patients, 61% versus approximately 50-60%). Sixty-two patients (31%) had T-cell lymphoma, including 11 angiocentric T/natural killer (NK)-cell lymphoma and only two angioimmunoblastic T-cell lymphoma (AILD). The recurrent chromosomal abnormalities in T-cell lymphoma comprised 6q deletion (30%), 11q deletion (20%), 17p deletion (16%), -17 (16%), -Y (14%) and + 8 (11%). Angiocentric T/NK-cell lymphoma had a significantly higher frequency of 1q duplication (P=0.001), 6p duplication (P <0.001) and 11q deletion (P=0.011) than other T-cell lymphoma. The incidences of +3 and +5, two common abnormalities in AILD, were quite low in T-cell lymphoma in Taiwan (4% and 2%, respectively), compared with those in the West (16-32% and approximately 15%, respectively). The 11q deletion, not a common aberration in T-cell lymphoma in western countries, occurred quite frequently in Taiwan.

CONCLUSIONS

The chromosomal aberrations of NHL are quite different among various geographical areas, which may reflect the differences in the distribution of the histological subtypes of lymphoma among various areas.

Evaluation of a high-volume portable bioaerosol sampler in laboratory and field environments

This study investigated the physical and biological performances of a portable centrifugal sampler for viable bioaerosols, RCS High Flow. The performance of the test sampler in the laboratory and field environments was compared with that of a reference sampler, BioSampler. The laboratory experiments with non-biological particles of KCl, oleic acid, and polystyrene latex showed that the test sampler's collection efficiency is about 22% for 0.5-microm particles, 48% for 1.0-microm particles, and approximately 100% for particles of 2.5 microm and larger. These tests indicated that the sampler's cut-off size (d50) was 1.1 microm. The test sampler's physical performance when collecting the spores and vegetative cells of Bacillus subtilis var. niger (BG) was similar to that when collecting non-biological particles of the same size. In the laboratory tests, the RCS High Flow sampler was found to enumerate approximately 40% of BG spores and cells relative to the reference sampler, BioSampler. A similar ratio was found during testing in an indoor environment. This ratio decreased to below 10% when testing was performed in an outdoor environment. We hypothesize that the test sampler's underperformance compared with the BioSampler could be caused by the damage to sensitive microorganisms during the collection process, test sampler's sensitivity to wind direction and speed as well as break-up of particle aggregates during the impingement process in BioSampler, which resulted in more colony-forming units (CFUs) being counted by the reference sampler than by the test sampler. Overall, when the RCS High Plus is used to sample culturable airborne microorganisms, the results obtained may have to be adjusted to avoid potential underestimation of microorganism concentration in the air.

PRACTICAL IMPLICATIONS

The laboratory testing of the RCS High Flow bioaerosol sampler showed that the sampler collects 1 microm particles and larger with an efficiency of 50% and higher; the efficiency reaches approximately 100% for particles of 2.5 microm and larger. When considering this result, most of the airborne fungal spores would be collected with an efficiency between 50 and 100%. The field testing, however, indicated that the RCS High Flow sampler recovered from 41 to 71% of microorganisms collected relative to the reference sampler, Biosampler, and this ratio dropped to below 5% during outdoor testing. Thus, while the RCS High Flow sampler offers certain advantages over other samplers for viable bioaerosols--it is lightweight, battery operated, and collects viable microorganisms at a high flow rate directly on agar media, the results obtained may have to be adjusted to avoid potential underestimation of microorganism concentration in the air, especially if sampling is performed outdoors.

Distribution and acute stressor-induced activation of corticotrophin-releasing hormone neurones in the central nervous system of Xenopus laevis

In mammals, corticotrophin-releasing hormone (CRH) and related peptides are known to play essential roles in the regulation of neuroendocrine, autonomic and behavioural responses to physical and emotional stress. In nonmammalian species, CRH-like peptides are hypothesized to play similar neuroendocrine and neurocrine roles. However, there is relatively little detailed information on the distribution of CRH neurones in the central nervous system (CNS) of nonmammalian vertebrates, and there are currently no comparative data on stress-induced changes in CRH neuronal physiology. We used a specific, affinity-purified antibody raised against synthetic Xenopus laevis CRH to map the distribution of CRH in the CNS of juvenile South African clawed frogs. We then analysed stress-induced changes in CRH immunoreactivity (CRH-ir) throughout the CNS. We found that CRH-positive cell bodies and fibres are widely distributed throughout the brain and rostral spinal cord of juvenile X. laevis. Strong CRH-immunoreactivity (ir) was found in cell bodies and fibres in the anterior preoptic area (POA, an area homologous to the mammalian paraventricular nucleus) and the external zone of the median eminence. Specific CRH-ir cell bodies and fibres were also identified in the septum, pallium and striatum in the telencephalon; the amygdala, bed nucleus of the stria terminalis and various hypothalamic and thalamic nuclei in the diencephalon; the tectum, torus semicircularis and tegmental nuclei of the mesencephalon; the cerebellum and locus coeruleus in the rhombencephalon; and the ventral horn of the rostral spinal cord. To determine if exposure to an acute physical stressor alters CRH neuronal physiology, we exposed juvenile frogs to shaking/handling and conducted morphometric analysis. Plasma corticosterone was significantly elevated by 30 min after exposure to the stressor and continued to increase up to 6 h. Morphometric analysis of CRH-ir after 4 h of stress showed a significant increase in CRH-ir in parvocellular neurones of the anterior preoptic area, the medial amygdala and the bed nucleus of the stria terminalis, but not in other brain regions. The stress-induced increase in CRH-ir in the POA was associated with increased Fos-like immunoreactivity (Fos-LI), and confocal microscopy showed that CRH-ir colocalized with Fos-LI in a subset of Fos-LI-positive neurones. Our results support the view that the basic pattern of CNS CRH expression arose early in vertebrate evolution and lend further support to earlier studies suggesting that amphibians may be a transitional species for descending CRH-ergic pathways. Furthermore, CRH neurones in the frog brain exhibit changes in response to a physical stressor that parallel those seen in mammals, and thus are likely to play an active role in mediating neuroendocrine, behavioural and autonomic stress responses.

The effects of hypothyroidism on nerve growth factor and norepinephrine concentrations in weight-bearing and non-weight-bearing bones of rats

Thyroid hormones affect bone remodelling directly via receptors in osteoblasts. Previously, however, we have shown that the euthyroid and hyperthyroid states significantly influence the concentrations of both nerve growth factor (NGF) and norepinephrine (NE) in particular bones. Both NGF and NE directly affect bone metabolism and therefore it is possible that thyroid hormone action on bone may also be indirect via its actions on these two neural-related substances. In light of previous studies, the current experiments aimed to investigate whether hypothyroidism also influenced NGF and NE concentrations in weight-bearing and non-weight-bearing rat bones. Hypothyroidism was induced by oral ingestion of propylthiouricil (PTU; 3.8+/-0.2 mg/kg/day) for 21 days. Histological examination on distal femurs and microparticle enzyme immunoassayed plasma concentrations of T3 and T4 verified the hypothyroid status in treated rats. NGF concentrations were assayed via enzyme-linked immunosorbent assay (ELISA) and NE concentrations were measured via high performance liquid chromatography (HPLC) with electrochemical detection (ECD). NGF concentrations: Femoral NGF concentrations were 207% higher in hypothyroid rats (674.9+/-88.3 ng/g) than in euthyroid rats (326.7+/-63.6 ng/g; p < 0.05). Rib NGF concentrations in hypothyroid rats (3125.1+/-450.2 ng/g) were increased by 342% compared to euthyroid ribs (914.5+/-128.6 ng/g; p < 0.01). Rib NGF concentrations in hypothyroid rats were 463% higher than in femurs of hypothyroid rats (p < 0.001). NE concentrations: In hypothyroid rats, NE concentrations were reduced by approximately 50% in both ribs (38.9 ng/g) and calvaria (41.5 ng/g) compared to euthyroid rats (74.7 ng/g and 87.4 ng/g respectively; p < 0.05 for both). These findings on hypothyroid rats may be taken in conjunction with our companion work on hyperthyroid rats (Yao et al., 2002, JMNI 2:327-334) and put in context with other reports, to indicate that (i) there are several sources of NGF in bone, some of which are stimulated by hypothyroidism and others by hyperthyroidism and (ii) the concentrations of both NGF and NE in bone are sensitive to weight-bearing and thyroid hormone status.