Overexpression of secretory leukocyte peptidase inhibitor (SLPI) does not modulate experimental osteoarthritis but may be a biomarker for the disease.

OBJECTIVE: Osteoarthritic cartilage destruction can be regulated by the balance between proteases and anti-proteases. Here, we sought to identify novel cellular protease inhibitors associated with osteoarthritis (OA) pathogenesis. METHODS: Candidate molecules were screened from microarray data of chondrocytes treated with OA-associated catabolic factors. The functions of candidate molecules in OA pathogenesis were examined in primary-culture mouse articular chondrocytes and mouse models of OA, such as those stimulated by destabilization of the medial meniscus (DMM) or intra-articular (IA) injection of adenovirus expressing the candidate gene. The value of the selected candidate molecule as a biomarker of OA was examined by measuring its circulating levels in human and mouse blood. RESULTS: Bioinformatic analysis identified secretory leukocyte peptidase inhibitor (SLPI) as a highly upregulated cellular protease inhibitor in chondrocytes treated with pathogenic catabolic factors, including interleukin (IL)-1ß, hypoxia-inducible factor (HIF)-2α, and zinc importer ZIP8. The adenovirus-mediated overexpression of SLPI in joint tissues did not cause any OA-like change or modulate DMM- or HIF-2α-induced experimental OA in mice. SLPI also did not markedly modulate the expression of OA-associated catabolic or anabolic factors in chondrocytes. However, SLPI was specifically upregulated in OA cartilage, and the serum SLPI levels were significantly elevated in human OA patients and experimental OA mice, suggesting that SLPI may be a biomarker of OA. CONCLUSION: Although SLPI is upregulated in OA chondrocytes, it does not appear to per se modulate OA development in mice. However, it may be a potential biomarker of OA in humans and animal models.

Effects of ultrasonic instrumentation on enamel surfaces with various defects.

OBJECTIVE: The aim of this study was to analyse the enamel damage caused by ultrasonic scaling of teeth with various enamel conditions that are difficult to identify by visual inspection, such as enamel cracks, early caries and resin restorations. METHODS: In total, 120 tooth surfaces were divided into 4 experimental groups using a quantitative light-induced fluorescence-digital system: sound enamel group, enamel cracks group, early caries group and resin restoration group. A skilled dental hygienist performed ultrasonic scaling under a standardized set of conditions: a ≤ 15° angle between the scaler tip and tooth surface and 40-80 g of lateral pressure at the rate of 12 times/10 s. Following scaling, the depth of enamel damage was measured using a surface profilometer and observed using scanning electron microscopy (SEM). RESULTS: The damage depth was the greatest in the enamel cracks group (37.63 ± 34.42 µm), followed by the early caries group (26.81 ± 8.67 µm), resin restoration group (19.63 ± 6.73 µm) and the sound enamel group (17.00 ± 5.66 µm). The damage depth was significantly deeper in the enamel cracks and early caries groups than in the sound enamel group (P < .05). SEM clearly revealed enamel loss in the enamel cracks, early caries and resin restoration groups. CONCLUSIONS: The results of this study suggest that ultrasonic scaling can cause further damage to teeth with enamel cracks, early caries and resin restorations. Therefore, accurate identification of tooth conditions and calculus before the initiation of ultrasonic scaling is necessary to minimize damage.

Upregulation of Atrogin-1/FBXO32 is not necessary for cartilage destruction in mouse models of osteoarthritis.

OBJECTIVE: In a preliminary study, we found that recently identified catabolic regulators of osteoarthritis (OA), including hypoxia-inducible factor (HIF)-2α and members of the zinc-ZIP8-MTF1 axis, upregulate the E3 ubiquitin ligase, Atrogin-1 (encoded by Fbxo32), in chondrocytes. As the ubiquitination/proteasomal degradation pathways are tightly regulated to modulate the expression of catabolic factors in chondrocytes, we examined the in vivo functions of Atrogin-1 in mouse models of OA. METHODS: The mRNA and protein levels of Atrogin-1 and other regulators of OA were determined in primary cultured mouse chondrocytes, OA human cartilage, and OA cartilage from wild-type (WT) and Fbxo32-knockout (KO) mice subjected to destabilization of the medial meniscus or intra-articular (IA) injection of adenoviruses expressing HIF-2α (Ad-Epas1), ZIP8 (Ad-Zip8), or Atrogin-1 (Ad-Fbxo32). The effect of Atrogin-1 overexpression on the cartilage of WT mice was examined by IA injection of Ad-Fbxo32. RESULTS: Atrogin-1 mRNA levels in chondrocytes were markedly increased by treatment with interleukin-1ß, HIF-2α, and members of the zinc-ZIP8-MTF1 axis. Atrogin-1 protein levels were also increased in OA cartilage from humans and various mouse OA models. However, the forced overexpression of Atrogin-1 in chondrocytes did not modulate the expression of cartilage matrix molecules or matrix-degrading enzymes. Moreover, overexpression of Atrogin-1 in the mouse joint tissues failed to cause OA pathogenesis, and Fbxo32 knockout failed to affect post-traumatic OA cartilage destruction in mice. CONCLUSIONS: Although Atrogin-1 is upregulated in OA cartilage, overexpression of Atrogin-1 in the joint tissues or knockout of Fbxo32 does not affect OA cartilage destruction in mice.

Evaluation of the bristle end-rounding patterns of children's toothbrushes using scanning electron microscopy and stereomicroscopy.

OBJECTIVES: The aim of this study was to evaluate the proportions of end-rounded bristles via observations of the end patterns of various children's toothbrushes with scanning electron microscopy (SEM) and stereomicroscopy. METHODS: Ten different brands of children's toothbrushes were chosen, and tufts from each toothbrush were used. The prepared bristle specimens were observed on SEM and stereomicroscopic images and classified as acceptable (A1-A3) and non-acceptable (N1-N5) according to the modified classification. Then, the proportions of end-rounded bristles were calculated. RESULTS: Analyses of the 10 toothbrushes revealed that the proportions of acceptable end-rounded bristles ranged from 1.4% to 20.2% on SEM and from 0.0% to 18.0% on stereomicroscopic examinations. Additionally, some toothbrushes had labels that indicated bristle end-rounding, but the proportions of end-rounded bristles were low. CONCLUSIONS: The types and percentages of bristle ends of children's toothbrushes marketed in Korea were various, but the amount of acceptable end-rounded bristles was low. The result, that even toothbrushes labelled as end-rounded had potential to harm oral tissue, demonstrates that quality control for rounding bristle ends as well as the labelling for end-rounded bristles is needed.

Reciprocal regulation by hypoxia-inducible factor-2α and the NAMPT-NAD(+)-SIRT axis in articular chondrocytes is involved in osteoarthritis.

OBJECTIVE: Hypoxia-inducible factor-2α (HIF-2α) transcriptionally upregulates Nampt in articular chondrocytes. NAMPT, which exhibits nicotinamide phosphoribosyltransferase activity, in turn causes osteoarthritis (OA) in mice by stimulating the expression of matrix-degrading enzymes. Here, we sought to elucidate whether HIF-2α activates the NAMPT-NAD(+)-SIRT axis in chondrocytes and thereby contributes to the pathogenesis of OA. METHODS: Assays of NAD levels, SIRT activity, reporter gene activity, mRNA, and protein levels were conducted in primary cultured mouse articular chondrocytes. Experimental OA in mice was induced by intra-articular (IA) injection of adenovirus expressing HIF-2α (Ad-Epas1) or NAMPT (Ad-Nampt). The functions of SIRT in OA were examined by IA co-injection of SIRT inhibitors or adenovirus expressing individual SIRT isoforms or shRNA targeting specific SIRT isoforms. RESULTS: HIF-2α activated the NAMPT-NAD(+)-SIRT axis in chondrocytes by upregulating NAMPT, which stimulated NAD(+) synthesis and thereby activated SIRT family members. The activated NAMPT-SIRT pathway, in turn, promoted HIF-2α protein stability by negatively regulating its hydroxylation and 26S proteasome-mediated degradation, resulting in increased HIF-2α transcriptional activity. Among SIRT family members (SIRT1-7), SIRT2 and SIRT4 were positively associated with HIF-2α stability and transcriptional activity in chondrocytes. This reciprocal regulation was required for the expression of catabolic matrix metalloproteinases (MMP3, MMP12, and MMP13) and OA cartilage destruction caused by IA injection of Ad-Epas1 Ad-Nampt. CONCLUSION: The reciprocal regulation of HIF-2α and the NAMPT-NAD(+)-SIRT axis in articular chondrocytes is involved in OA cartilage destruction caused by HIF-2α or NAMPT.

Photobiomodulation of Gingival Cells Challenged with Viable Oral Microbes.

The oral cavity, a unique ecosystem harboring diverse microorganisms, maintains health through a balanced microflora. Disruption may lead to disease, emphasizing the protective role of gingival epithelial cells (GECs) in preventing harm from pathogenic oral microbes. Shifting GECs' response from proinflammatory to antimicrobial could be a novel strategy for periodontitis. Photobiomodulation therapy (PBMT), a nonpharmacologic host modulatory approach, is considered an alternative to drugs. While the host cell response induced by a single type of pathogen-associated molecular patterns (PAMPs) was widely studied, this model does not address the cellular response to intact microbes that exhibit multiple PAMPs that might modulate the response. Inspired by this, we developed an in vitro model that simulates direct interactions between host cells and intact pathogens and evaluated the effect of PBMT on the response of human gingival keratinocytes (HGKs) to challenge viable oral microbes at both the cellular and molecular levels. Our data demonstrated that LED pretreatment on microbially challenged HGKs with specific continuous wavelengths (red: 615 nm; near-infrared: 880 nm) induced the production of various antimicrobial peptides, enhanced cell viability and proliferation, promoted reactive oxygen species scavenging, and down-modulated proinflammatory activity. The data also suggest a potential explanation regarding the superior efficacy of near-infrared light treatment compared with red light in enhancing antimicrobial activity and reducing cellular inflammation of HGKs. Taken together, the findings suggest that PBMT enhances the overall barrier function of gingival epithelium while minimizing inflammation-mediated breakdown of the underlying structures.

Subjective Fatigue in Children With Unaided and Aided Unilateral Hearing Loss.

OBJECTIVES: Fatigue is frequently observed in children with chronic diseases and can affect the quality of life (QoL). However, research in children with unilateral hearing loss (UHL) is scarce. Subsequently, no studies investigated the effects of hearing aids on fatigue in children. This study investigates subjective fatigue and hearing-related QoL in children with UHL. Furthermore, it evaluates the influence of hearing aids, subject-specific factors, and respondent-type on subjective fatigue. STUDY DESIGN: A cross-sectional study was conducted from June 2020 until September 2020 at the department of otorhinolaryngology in a tertiary referral center. METHODS: The primary outcome was the difference in subjective fatigue and hearing-related QoL between children with unaided UHL, aided UHL, and normal hearing. Subjective fatigue and hearing-related QoL were measured using the Pediatric Quality of Life Inventory™ Multidimensional Fatigue Scale (PedsQL™-MFS) and Hearing Environments and Reflection on Quality of Life (HEAR-QL™) questionnaires. RESULTS: Along with 36 aided children with UHL, 34 unaided and 36 normal-hearing children were included. Child reports revealed significantly more cognitive fatigue in children with aided UHL than children with normal hearing (median difference 12.5, P = .013). Parents reported more fatigue in children with UHL compared to normal-hearing siblings. Especially children with aided UHL seemed at increased risk for fatigue. Children with UHL scored lower on hearing-related QoL than children with normal hearing. No apparent differences were found in fatigue and QoL between children with unaided and aided UHL. CONCLUSION: Children with unaided and even aided UHL seem to experience more subjective fatigue and lower hearing-related QoL than children with normal hearing. Prospective longitudinal studies are required to investigate the influence of hearing aids on fatigue and QoL in individual patients. LEVEL OF EVIDENCE: 3 Laryngoscope, 2021 Laryngoscope, 133:189-198, 2023.

Intervening in Symbiotic Cross-Kingdom Biofilm Interactions: a Binding Mechanism-Based Nonmicrobicidal Approach.

Early childhood caries is a severe oral disease that results in aggressive tooth decay. Particularly, a synergistic association between a fungus, Candida albicans, and a cariogenic bacterium, Streptococcus mutans, promotes the development of hard-to-remove and highly acidic biofilms, exacerbating the virulent damage. These interactions are largely mediated via glucosyltransferases (GtfB) binding to mannans on the cell wall of C. albicans Here, we present an enzymatic approach to target GtfB-mannan interactions in this cross-kingdom consortium using mannan-degrading exo- and endo-enzymes. These exo- and endo-enzymes are highly effective in reducing biofilm biomass without killing microorganisms, as well as alleviating the production of an acidic pH environment conducive to tooth decay. To corroborate these results, we present biophysical evidence using single-molecule atomic force microscopy, biofilm shearing, and enamel surface topography analyses. Data show a drastic decrease in binding forces of GtfB to C. albicans (∼15-fold reduction) following enzyme treatment. Furthermore, enzymatic activity disrupted biofilm mechanical stability and significantly reduced human tooth enamel demineralization without cytotoxic effects on gingival keratinocytes. Our results represent significant progress toward a novel nonbiocidal therapeutic intervention against pathogenic bacterial-fungal biofilms by targeting the interkingdom receptor-ligand binding interactions.IMPORTANCE Biofilm formation is a key virulence factor responsible for various infectious diseases. Particularly, interactions between a fungus, Candida albicans, and a bacterium, Streptococcus mutans, have been known to play important roles in the pathogenesis of dental caries. Although some antimicrobials have been applied to treat fungal-involved biofilm-associated diseases, these often lack targeting polymicrobial interactions. Furthermore, these may not be appropriate for preventive measures because these antimicrobials may disrupt ecological microbiota and/or induce the prevalence of drug resistance over time. By specifically targeting the interaction mechanism whereby mannoproteins on the C. albicans surface mediate the cross-kingdom interaction, we demonstrated that mannoprotein-degrading enzymes can effectively disrupt biofilm interactions without microbiocidal effects or causing cytotoxicity to human cells. This suggests a potential application as a targeted approach for intervening a pathogenic cross-kingdom biofilm associated with a costly and unresolved oral disease.

Application of fluoride iontophoresis to improve remineralization.

Iontophoresis is generally used to maximize the therapeutic action of drugs in medicine. This technique can be used to improve the remineralization effect of topical fluoride applications in dentistry. The aim of this study was to compare the remineralization effect of fluoride iontophoresis (FI) with the conventional fluoride application (CFA) method in vitro. Sixty bovine enamel specimens were divided into three groups: no fluoride treatment, CFA and FI. Fluoride was applied to the demineralized specimens for 4 min in each experimental group. The types of fluoride system used for application were 1.23% acidulated phosphate fluoride gel (12 300 p.p.m. F, pH 3.5) and 2% sodium fluoride solution (9050 p.p.m. F, pH 7) in the experimental groups. All the specimens were then placed in a remineralizing solution for 24 h. This cycle was repeated five times. An iontophoresis device (0.4 mA, 12 V) was used in the FI groups. The efficacy of this technique was evaluated by measuring changes in the surface microhardness and lesion depth of the specimens using confocal laser scanning microscope (CLSM). Data were analysed using anova and Tukey's post hoc test (P < 0.05). Although the FI groups showed higher DeltaVHN than the CFA groups, there were no significant differences between these fluoride application methods (P > 0.05). When the lesion depth was measured using CLSM imaging, there was also no significant difference between the FI and CFA groups (P > 0.05). In conclusion, FI was not significantly superior to CFA in terms of the remineralization effect.

Disruption of the myocardial extracellular matrix leads to cardiac dysfunction.

MMP activity with disruption of structural collagen has been implicated in the pathophysiology of dilated cardiomyopathy. To examine the role of this enzyme in cardiac function, a transgenic mouse was created that constitutively expressed human collagenase (MMP-1) in the heart. At 6 months of age, these animals demonstrated compensatory myocyte hypertrophy with an increase in the cardiac collagen concentration due to elevated transcription of type III collagen. Chronic myocardial expression of MMP-1 produced loss of cardiac interstitial collagen coincident with a marked deterioration of systolic and diastolic function at 12 months of age. This is the first animal model demonstrating that direct disruption of the extracellular matrix in the heart reproduces the changes observed in the progression of human heart failure.

Neutron radiation enhances cisplatin cytotoxicity independently of apoptosis in human head and neck carcinoma cells.

Recent advances in combined modality treatment of locally advanced head and neck cancer have improved local and regional disease control and survival with better functional outcome. However, the local and regional failure rate after radiation therapy is still high for tumors that respond poorly to cisplatin-based neoadjuvant chemotherapy. This clinical observation suggests a common biological mechanism for resistance to cisplatin and photon irradiation. In this report, we investigated the molecular basis underlying cisplatin resistance in head and neck squamous carcinoma (HNSCC) cells and asked if fast neutron radiation enhances cisplatin cytotoxicity in cisplatin-resistant cells. We found that cisplatin sensitivity correlates with caspase induction, a cysteine proteinase family known to initiate the apoptotic cell death pathway, suggesting that apoptosis may be a critical determinant for cisplatin cytotoxicity. Neutron radiation effectively enhanced cisplatin cytotoxicity in HNSCCs including cisplatin-resistant cells, whereas photon radiation had little effect on cisplatin cytotoxicity. Interestingly, neutron-enhanced cisplatin cytotoxicity was associated neither with apoptosis nor with cell cycle regulation, as determined by caspase activity assay, annexin V staining, and flow cytometric analysis. Taken together, the present study provides a molecular insight into cisplatin resistance and may also provide a basis for more effective multimodality protocols involving neutron radiation for patients with locally advanced head and neck cancer.

Platelet-derived growth factor (PDGF)-signaling mediates radiation-induced apoptosis in human prostate cancer cells with loss of p53 function.

Platelet-derived growth factor (PDGF) signals a diversity of cellular responses in vitro, including cell proliferation, survival, transformation, and chemotaxis. PDGF functions as a "competence factor" to induce a set of early response genes expressed in G1 including p21WAF1/CIP1, a functional mediator of the tumor suppressor gene p53 in G1/S checkpoint. For PDGF-stimulated cells to progress beyond G1 and transit the cell cycle completely, progression factors in serum such as insulin and IGF-1 are required. We have recently shown a novel role of PDGF in inducing apoptosis in growth-arrested murine fibroblasts. The PDGF-induced apoptosis is rescued by insulin, suggesting that G1/S checkpoint is a critical determinant for PDGF-induced apoptosis. Because recent studies suggest that radiation-induced signal transduction pathways interact with growth factor-mediated signaling pathways, we have investigated whether activation of the PDGF-signaling facilitates the radiation-induced apoptosis in the absence of functional p53. For this study we have used the 125-IL cell line, a mutant p53-containing, highly metastatic, and hormone-unresponsive human prostate carcinoma cell line. PDGF signaling is constitutively activated by transfection with a p28v-sis expression vector, which was previously shown to activate PDGF alpha- and beta- receptors. Although the basal level of p21WAF1/CIP1 expression and radiation-induced apoptosis were not detectable in control 125-IL cells as would be predicted in mutant p53-containing cells, activation of PDGF-signaling induced expression of p21WAF1/CIP1 and radiation-induced apoptosis. Our study suggests that the level of "competence" growth factors including PDGF may be one of the critical determinants for radiation-induced apoptosis, especially in cells with loss of p53 function at the site of radiotherapy in vivo.

Ion-beam-assisted deposition (IBAD) of hydroxyapatite coating layer on Ti-based metal substrate.

A hydroxyapatite layer was formed on the surface of a Ti-based alloy by ion-beam-assisted deposition. The deposition methodology comprised of an electron beam vaporizing a pure hydroxyapatite target, while an Ar ion beam was focused on the metal substrate to assist deposition. All deposited layers were amorphous, regardless of the current level of the ion beam. The bond strength between the layer and the substrate increased steadily with increasing current, while the dissolution rate in a physiological saline solution decreased remarkably. These improvements were attributed to an increase in the Ca/P ratio of the layer. Without ion beam assistance, the Ca/P ratio was much lower than the stoichiometric HAp (Ca/P = 1.67). With ion-beam assistance, the Ca/P ratio of the layer increased presumably due to the high sputtering rate of P compared to that of Ca from the layer being coated.

Ginsenoside RH-2 induces apoptotic cell death in rat C6 glioma via a reactive oxygen- and caspase-dependent but Bcl-X(L)-independent pathway.

We used the rat C6 gliomal cell line to investigate the potential role of ginsenoside Rh2 (G-Rh2) in brain tumor. G-Rh2 induced many apoptotic manifestations in C6 gliomal cells as evidenced by changes in cell morphology, generation of DNA fragmentation, activation of caspase and production of reactive oxygen species (ROS). As a result, cotreatment with antioxidants or a broad-spectrum caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone effectively attenuated G-Rh2-induced cell death. However, specific cleavage of poly(ADP-ribose)polymerase into 85 kDa protein was not detected as demonstrated in many other apoptotic paradigms. Expression levels of Bcl-2 and Bax remained unchanged following G-Rh2 treatment. Furthermore, G-Rh2-induced cell death in C6 gliomal cells overexpressing antiapoptotic protein, Bcl-X(L), was comparable to that in parental cells. Taken together, our data indicate that G-Rh2-induced cell death is mediated by the generated ROS and the activation of caspase pathway in a Bcl-X(L)-independent manner.

Effects of time of day on dressing behavior under the influence of ambient temperature fall from 30 degrees C to 15 degrees C.

The present paper is aimed at determining whether the dressing behavior for temperature regulation in cold is under the influences of circadian control. The half-naked subjects were instructed to dress in the garments they felt comfortable when the room temperature began to decrease from 30 degrees C to 15 degrees C in 1 h. To determine the effects of brain temperature fall on the dressing behavior, we used face cooling with cool air for 30 min before the room temperature began to decrease. We also studied the effects of wearing a hat on dressing behavior. Rectal temperature, tympanic temperature, skin temperature at seven sites, and thermal sensation were recorded. Major findings are summarized as follows: 1) the subjects dressed faster with thicker clothing in the morning than in the evening; 2) the subjects with face cooling dressed faster with thicker clothing than the subjects without face cooling; 3) the subjects without a hat dressed more rapidly with thicker, heavier clothing. These results were discussed in terms of load error between actual and set-point values in the core temperature.

Effects of the menstrual cycle on dressing behavior in the cold.

The purpose of the present study was to determine the effect of the menstrual cycle on dressing behavior in cold exposure. Rectal and skin temperatures, temperature sensation and metabolic rate were measured in seven women during the luteal (L) and the follicular (F) phases of the menstrual cycle, as was their dressing behavior in these two phases. The subjects were instructed to dress so as to feel comfortable when the ambient temperature was decreased from 30 degrees C to 15 degrees C (07:00-09:00). Most subjects dressed more quickly and with thicker clothing in the L phase. They felt cooler in the L phase during the last 30 min of the temperature fall. Rectal and skin temperatures showed significant differences between L and F phases and metabolic rate was significantly higher in the L phase. The results can be interpreted in terms of the establishment of a higher set-point in core temperature during the L phase.

Influence of different light intensities during the daytime on evening dressing behavior in the cold.

The primary purpose of this study was to determine the effect of bright light exposure during the daytime on dressing behavior in the cold. Seven female volunteers were exposed to bright light of 4,000 lx ("Bright") or dim light of 10 lx ("Dim") from 10 h to 18 h, complete darkness during the sleep period (22:30 h-06:00 h), and 10 lx for the rest of the time. The subjects were instructed to dress to remain comfortable when the ambient temperature was decreased from 30 degrees to 15 degrees C (20:30 h-22:30 h). Most subjects dressed more quickly and with thicker clothing in the Dim condition and felt cooler during the last 30 min of the temperature fall. The rectal temperature showed clear circadian rhythm both under Bright and Dim conditions, but it was significantly lower during sleep in the Bright condition. It is suggested that the set-point of core temperature is reduced at night during the Bright condition.

Effects of ion beam-assisted deposition of hydroxyapatite on the osseointegration of endosseous implants in rabbit tibiae.

The aim of this study was to evaluate the effects of coating implants with hydroxyapatite (HA) by an ion beam-assisted deposition (IBAD) method and to compare them with implants prepared with sand-blasted and machined surfaces. Examination of osteoblast cultures displayed no difference in the secretion of alkaline phosphatase (ALP) between the various surfaces, but the IBAD-HA specimen showed low ALP secretion (P < .05). Removal torque tests showed that implants coated with HA by the IBAD method had values similar to the implants with a sandblasted surface, but values for the machined-surface implants differed. Implants placed in a group of ovariectomized rabbits showed lower mechanical test values than implants placed in sham-operated rabbits (P < .05). Implants coated with HA by the IBAD method demonstrated the highest mean bone-to-metal contact ratio on all threads and on the 3 best consecutive threads, followed by the implants with a sandblasted surface and implants with a machined surface (P < .05). Hydroxyapatite-coated implants showed a slightly higher bone-to-implant contact ratio than sandblasted implants, but no statistically significant difference was seen between the 2 materials. The implants placed in ovariectomized rabbits showed lower amounts of bone-to-metal contact than the implants placed in sham-operated rabbits, but no statistically significant difference was seen between the 2 groups. Evaluation of bone volume on all threads and the 3 best consecutive threads showed no statistically significant difference among the different surface treatment groups, but lower bone volume was seen in the ovariectomized rabbits than in the sham-operated animals (P < .05).

In vitro differentiation of human liver-derived stem cells with mesenchymal characteristics into immature hepatocyte-like cells.

Liver transplantation is severely limited by donor shortage although it is the only effective treatment for end-stage liver disease. So the best alternative is hepatocyte transplantation. For obtaining human hepatocytes, some stem cells originating from extrahepatic or intraheptic tissues have been isolated and characterized. Previously we have reported that human liver-derived stem cells (HLSCs) could be isolated and expanded from donated livers unsuitable for transplantation; they expressed some markers of mesenchymal stem cells but neither hematopoietic nor oval cells. In this study, we isolated and expanded HLSCs with mesenchymal characteristics from another adult human liver. They showed mesenchymal morphology and grew well under serum condition similar to our previous reports. Also, they expressed some markers of mesenchymal stem cells, such as CD44, CD73, CD90, and CD105, through fluorescence-activated cell sorting analysis. When HLSCs were sequentially exposed to fibroblast growth factor-1 (FGF-1), FGF-4, and hepatocyte growth factor (HGF) followed by FGF-4, HGF, oncostatin M, and dexamethasone, they became round or polygonal, and expressed some hepatic markers such as albumin and α1-antitrypsin in the gene or protein level. Also, they showed urea synthesis activity 7 days after treatment of FGF-4, HGF, oncostatin M, and dexamethasone. These results provided that HLSCs would be a useful cell source in the field of regenerative medicine as well as liver cell biology.

RTOG 0518: randomized phase III trial to evaluate zoledronic acid for prevention of osteoporosis and associated fractures in prostate cancer patients.

BACKGROUND: RTOG 0518 evaluated the potential benefit of zoledronic acid therapy in preventing bone fractures for patients with high grade and/or locally advanced, non-metastatic prostate adenocarcinoma receiving luteinizing hormone-releasing hormone (LHRH) agonist and radiotherapy (RT). METHODS: Eligible patients with T-scores of the hip (<-1.0, but >-2.5 vs >-1.0) and negative bone scans were prospectively randomized to either zoledronic acid, 4 mg, concurrently with the start of RT and then every six months for a total of 6 infusions (Arm 1) or observation (Arm 2). Vitamin D and calcium supplements were given to all patients. Secondary objectives included quality of life (QOL) and bone mineral density (BMD) changes over a period of three years. RESULTS: Of 109 patients accrued before early closure, 96 were eligible. Median follow-up was 36.3 months for Arm 1 and 34.8 months for Arm 2. Only two patients experienced a bone fracture (one in each arm) resulting in no difference in freedom from any bone fracture (P=0.95), nor in QOL. BMD percent changes from baseline to 36 months were statistically improved with the use of zoledronic acid compared to observation for the lumbar spine (6% vs -5%, P<0.0001), left total hip (1% vs -8%, P=0.0002), and left femoral neck (3% vs -8%, P=0.0007). CONCLUSIONS: For patients with advanced, non-metastatic prostate cancer receiving LHRH agonist and RT, the use of zoledronic acid was associated with statistically improved BMD percent changes. The small number of accrued patients resulted in decreased statistical power to detect any differences in the incidence of bone fractures or QOL.