Acquired radioresistance of human tumor cells by DNA-PK/AKT/GSK3beta-mediated cyclin D1 overexpression

Recurrence is frequently associated with the acquisition of radioresistance by tumors and resulting failures in radiotherapy. We report, in this study, that long-term fractionated radiation (FR) exposures conferred radioresistance to the human tumor cells, HepG2 and HeLa with cyclin D1 overexpression. A positive feedback loop was responsible for the cyclin D1 overexpression in which constitutively active AKT was involved. AKT is known to inactivate glycogen synthase kinase-3beta (GSK3beta), which is essential for the proteasomal degradation of cyclin D1. The resulting cyclin D1 overexpression led to the forced progression of S-phase with the induction of DNA double strand breaks. Cyclin D1-dependent DNA damage activated DNA-dependent protein kinase (DNA-PK), which in turn activated AKT and inactivated GSK3beta, thus completing a positive feedback loop of cyclin D1 overproduction. Cyclin D1 overexpression led to the activation of DNA damage response (DDR) consisted of ataxia telangiectasia mutated (ATM)- and Chk1-dependent DNA damage checkpoint and homologous recombination repair (HRR). Long-term FR cells repaired radiation-induced DNA damage faster than non-FR cells. Thus, acquired radioresistance of long-term FR cells was the result of alterations in DDR mediated by cyclin D1 overexpression. Inhibition of the AKT/GSK3beta/cyclin D1/Cdk4 pathway by the AKT inhibitor, Cdk4 inhibitor or cyclin D1 targeting small interfering RNA (siRNA) suppressed the radioresistance. Present observations give a mechanistic insight for acquired radioresistance of tumor cells by cyclin D1 overexpression, and provide novel therapeutic targets for recurrent radioresistant tumors.

Depression among caregivers of the frail elderly in Japan before and after the introduction of the Public Long-Term Care Insurance System

Cross sectional studies were conducted in five towns in Japan before and after the introduction of the Long-term Care Insurance System (LTCIS), in order to evaluate the factors relating to depression among family caregivers for the frail elderly. Depressive caregivers were more likely to consult with their doctors, to be in poor health, to care for demented elderly with behavioral disturbances than the non-depressive caregivers both before and after the LTCIS. Before LTCIS, depressive caregivers were more likely to attend to the elderly for more than 16 hours per day than their counterparts. After the LTCIS, depressive caregivers were more likely to be a spouse, to care for a frail elderly male, and less likely to be able to go out without accompanying the elderly than their counterparts. Even after the introduction of LTCIS, half of the caregivers were depressive. It is suggested that a government agency should be created to support not only the frail elderly but also their caregivers.

Measurements of short-lived cosmic-ray-produced radionuclides in rainwater

Cosmic-ray-produced (CP) nuclides with half-lives shorter than 21h were measured in rainwater by ultra-low-background gamma spectrometry at Ogoya Underground Laboratory. As levels of CP nuclides are extremely low and their half-lives are very short, quick sampling methods for a large volume of rainwater and rapid chemical separations by ion exchange method were developed. The nuclides measured were short-lived (24)Na, (28)Mg, (38)S, (38)Cl, (39)Cl, as well as nuclides with longer half-lives (7)Be and (22)Na. The number of atoms of CP nuclides in rainwater were evaluated to range from 30 to 1500L(-1) for (24)Na (n=16, mean; 520 [6.7mBqL(-1)]), 80 to 600L(-1) for (28)Mg (n=13, mean; 260 [2.4mBqL(-1)]), 400 to 1900L(-1) for (39)Cl (n=6, mean; 1200 [250mBqL(-1)]), 1x10(6) to 4x10(7)L(-1) for (7)Be (n=16, mean; 7x10(6) [1.05BqL(-1)]) and 2x10(3) to 1x10(5)L(-1) for (22)Na (n=9, mean; 2x10(4) [0.2mBqL(-1)]).

Association of laboratory data and death within one month in cats with chronic renal failure

OBJECTIVES

To retrospectively compare the data taken at the first visit of 34 cats with chronic renal failure surviving more than one month (surviving group) and 16 cats dying within one month (non-surviving group).

METHODS

Records were collected on cats with chronic renal failure presented to a private veterinary practice in Nagoya, Japan, from March 1996 to March 2005. All cats with chronic renal failure diagnosed on the basis of case histories, clinical signs (such as, lethargy, anorexia, loss of bodyweight and vomiting) and a high plasma creatinine (>180 micromol/l) were included in the study.

RESULTS

Plasma creatinine, urea nitrogen, inorganic phosphate, packed cell volume and urine protein/creatinine ratio were significantly different between cats of the surviving and non-surviving groups. In the surviving group, survival statuses were recorded, and laboratory data was obtained within one month before death in 13 cats. In the 13 cats, plasma creatinine, packed cell volume and urine protein/creatinine ratio showed significant differences between the data taken within one month before death and that taken at first visit, and only urine protein/creatinine ratio exhibited a consistent alteration (increase) in relation to first visit data.

CLINICAL SIGNIFICANCE

These results indicated that plasma creatinine, urea nitrogen, inorganic phosphate, packed cell volume and urine protein/creatinine ratio were associated with death within one month and urine protein/creatinine ratio was most likely to be associated with mortality in cats with chronic renal failure.

Cytochemical Localization of Glycoconjugates in the Secretory Epithelial Cells Lining the Prostate Gland of the Miniature Pig

The aim of the study was to emphasize several specific functional aspects of the mammalian prostate gland. In this connection, the subcellular localization and characterization of glycoconjugates in the secretory epithelial cells were examined that line the prostate gland of the miniature pig, using cytochemistry, including lectin-gold methods. The results verified a diversified pattern of glycoconjugates in the structures of the secretory cells. The secretory granules and the free surface coat of the plasma membrane contained several sugar moieties such as alpha-D-Man, alpha-D-Glc, alpha-L-Fuc, beta-D-Gal, GalNAc, GlcNAc and NeuAc (sialic acid), whereas the Golgi apparatus exhibited GlcNAc and sialic acid residues. In addition, the cisterns of the endoplasmic reticulum showed alpha-D-Man and alpha-D-Glc moieties. It seems likely that the secretory glycoconjugates demonstrated contribute to favourable conditions for fertilization.

Morphological, histochemical and immunohistochemical characterization of secretory production of the ciliary glands in the porcine eyelid

In addition to performing general histology and cytology of the ciliary glands of the miniature pig, we studied the localization of glycoconjugates and beta-defensins in these glands with the use of carbohydrate histochemical and immunohistochemical methods. The secretory cells of the glands were equipped with non-homogeneous secretory granules, a well-developed Golgi apparatus and rough endoplasmic reticulum. The secretory epithelium and luminal secretion of the glands contained large amounts of neutral and acidic glycoconjugates with various saccharide residues (alpha-L-Fuc, beta-D-Gal, alpha-D-GalNAc and sialic acid). The sebaceous glands and tarsal glands also exhibited positive reactions to most of the histochemical methods. Additionally, the antimicrobial peptide group of beta-defensins was demonstrated to be products of the ciliary glands, as well as the sebaceous glands and tarsal glands. The results obtained are discussed with regard to the specific function of the ciliary glandular secretions. These secretory products may be related to the moistening and general protection of the skin surface of the eyelid and ocular surface.

Neuroradiologic and clinicopathologic features of oculoleptomeningeal type amyloidosis

OBJECTIVE

To clarify the pathogenesis of leptomeningeal amyloidosis in familial amyloidotic polyneuropathy amyloidogenic transthyretin Y114C (FAP ATTR Y114C).

METHODS

The authors analyzed eight FAP ATTR Y114C patients. Six patients showed CNS symptoms associated with leptomeningeal amyloidosis. To examine the function of the blood-CSF barrier and blood-brain barrier (BBB), the authors performed CSF and MRI studies. The authors also performed a histopathologic study of autopsy specimens to examine the distribution of amyloid deposition in the CNS.

RESULTS

CSF study showed high total protein concentrations and increased albumin CSF/serum concentration quotients (Qalb; an indication of blood-CSF barrier function). MRI with gadolinium (Gd) revealed enhancement from brainstem to spinal cord. Serial brain MRI studies with FLAIR images after Gd administration showed Gd leakage into the subarachnoid space (two patients). These findings suggested the blood-CSF barrier and BBB dysfunctions. Constructive interference in steady state (CISS) three-dimensional Fourier transformation (CISS-3DFT) sequence analysis demonstrated amyloid-induced funiculus structures joining the spinal cord and dura mater (one patient). Histopathologic study revealed intense amyloid deposition in leptomeninges, vessel walls, and parenchyma in spinal cord and the brain. These distributions of amyloid deposition are unique compared to other TTR related leptomeningeal amyloidosis.

CONCLUSIONS

Patients with familial amyloidotic polyneuropathy amyloidogenic transthyretin Y114C had CNS disorders related to amyloid deposition in leptomeninges, vessel walls, and parenchyma in spinal cord and the brain. The pathogenesis of CNS disorders may reflect disruption of the blood-CSF barrier and blood-brain barrier by amyloid deposition.

Electronic structure of a polydiacetylene nanowire fabricated on highly ordered pyrolytic graphite

A molecular wire candidate, the polydiacetylene chain, fabricated in a substantial support layer of monomers self-assembled on a highly ordered pyrolytic graphite surface, was studied using scanning tunneling microscopy and spectroscopy. The density of states of individual polymers and constituent monomers were observed on the same surface, and then compared with the calculated results. The spectrum delineating the density of states of the polydiacetylene wire clearly reveals the theoretically predicted pi-band and band edge singularities of the one-dimensional polymer.

Correlation between facial morphology, mouth opening ability, and condylar movement during opening-closing jaw movements in female adults with normal occlusion

The aim of this study was to investigate the relationship between parameters of facial morphology, maximal voluntary mouth opening ability, and condylar movements in 21 adult females, aged between 20 and 24 years. The subjects had a normal occlusion without sign or symptoms of temporomandibular joint (TMJ) dysfunction. Mandibular movements were recorded using an opto-electric jaw movement recording system with six degrees of freedom under a series of maximal mouth opening-closing movements. Maximal jaw opening and coincident condylar movement were measured three-dimensionally. The mean values of the incisor and condylar path were 41.1 +/- 3.5 mm (range 35.6-50.9 mm) and 12.8 +/- 2.8 mm (range 8.1-19.2 mm), respectively. Although the positive correlation between maximal jaw opening and facial morphology was significant, none of the variables significantly differed between the value of the condylar path and facial morphology. The length of the path of maximum incisor movement and the condylar path during mandibular movement also did not correlate. Stepwise multiple regression analysis indicated a positive association between the maximal length of the incisor path and the cephalometric value of mandibular ramus inclination (R2 value was 0.369). The results of this study suggest that facial morphology size has a limited effect on maximal voluntary mandibular opening and condylar movements in normal adult female subjects.

(4E)-dehydrocitrals [(2E,4E)- and (2Z,4E )-3,7-dimethyl-2,4,6-octatrienals] from acarid mite Histiogaster sp. A096 (Acari: Acaridae)

A mixture of two monoterpenes was obtained as the opisthonotal gland secretion from unidentified Histiogaster sp. A096 (Acari: Acaridae), and their structures were elucidated to be (4E)-dehydrocitrals [(2E,4E)- and (2Z,4E)-3,7-dimethyl-2,4,6-octatrienals] by GC/MS, GC/FT-IR, UV and 1H-NMR spectra. Both isomers of (4E)-dehydrocitral prepared by syntheses in 4 steps from 3-methyl-2-butenal with 34.2% yields (based on the ylide) were separated by column chromatography into the (2E,4E)- and (2Z,4E)-3,7-dimethyl-2,4,6-octatrienal. Mass spectra together with GC retention times of the purified natural (4E)-dehydrocitrals were identical with those of synthetic (2E,4E)-3,7-dimethyl-2,4,6-octatrienal and (2Z,4E)-3,7-dimethyl-2,4,6-octatrienal. The geometry at the 2-C position of both synthetic (4E)-dehydrocitrals was confirmed by NOESY analyses. This is the first identification of (4E)-dehydrocitrals from the animal kingdom.

Structural elucidation and synthesis of 3-hydroxybenzene-1,2-dicarbaldehyde from astigmatid mites

The structure of a novel aromatic compound contained in the unidentified Rhizoglyhus mite (Acaridae: Astigmata) was elucidated, without its isolation, to be 3-hydroxybenzene-1,2-dicarbaldehyde (tentatively named gamma-acaridial) by a combination of GC/MS and GC/FT-IR together with knowledge of related mite compounds. The structure was confirmed by a 5-step synthesis, starting from methyl 3-hydroxybenzoate, in a 15% overall yield. The compound is widely distributed not only among Astigmata but also among Oribatida, although its biological function is obscure at present.

Effects of genotype matching of feline major histocompatibility complex (FLA) class II DRB on skin-allograft transplantation in cats

In order to confirm the effects of matching of expressed feline major histocompatibility complex (FLA) class II DRB genotype on transplantation immunity in cats, skin-allogeneic transplantation was carried out between cats, in which DRB genes expressed were genotyped by the RT-PCR-RFLP method using group-specific primers. Duration until grafts were rejected was 14.63 +/- 1.69 days (mean +/- standard deviation) in the pairs that had the same type of subgroups, 7.25 +/- 0.71 days in the pairs that had one different type of subgroup and 6.88 +/- 0.35 days in the pairs that had two different types of subgroups. The duration of graft survival in the pairs with the same type of subgroups was significantly longer (P<0.01) than those in the pairs with different types. Although FLA components involved in transplantation immunity should not only be DRB genes, it was suggested that the expressed FLA-DRB genotype might associate with feline transplantation immunity, and that typing and matching of expressed FLA-DRB genes might be one of the important factors in the control of feline transplantation immunity.

Burden among caregivers of frail elderly in Japan

The present study was conducted in order to investigate the factors related to the feelings of psychological stress, called heavy burden, in caregivers who took care of frail elderly in the eastern part of Fukuoka Prefecture, Kyushu, Japan. Fifty-eight caregivers answered a self-administered questionnaire, involving the Japanese version of the Zarit Caregiver Burden Interview (ZBI) and thus described their own caregiving situation. Compared to caregivers with a light burden, heavily burdened caregivers were less likely to have time to go out without patients, but were more likely to consult physicians. Heavily burdened caregivers spent a longer time on looking after the elderly as well as on physical caregiving, and also used more social services than lightly burdened caregivers. However, the physical disabilities of the patients did not differ between the two groups. Even after controlling for confounding factors, the time spent on looking after frail elderly was found to be a significant factor related to the caregivers' heavy burden (10-24 hrs vs. 0-9 hrs; odds ratio: 5.35, 95% confidence interval: 1.17-25.58). These findings suggest that looking after frail elderly for a long time seems to be an important factor related to caregivers' developing psychological feelings of heavy burden.