Technical note: An evaluation of technology-recorded rumination and feeding behaviors in dairy heifers.

Precision dairy monitoring technologies have become increasingly popular for recording rumination and feeding behaviors in dairy cattle. The objective of this study was to validate the rumination and feeding time functions of the CowManager SensOor (Agis, Harmelen, the Netherlands) against visual observation in dairy heifers. The study took place over a 44-d period beginning June 1, 2016. Holstein heifers equipped with CowManager SensOor tags attached according to manufacturer specifications (n = 49) were split into 2 groups based on age, diet, and housing type. Group 1 heifers (n = 24) were calves (mean ± SD) 2.0 ± 2.7 mo in age, fed hay and calf starter, and housed on a straw-bedded pack. Group 2 heifers (n = 25) were 17.0 ± 1.3 mo in age, fed a TMR, confirmed pregnant, and housed in freestalls. Visual observation shifts occurred at 1500, 1700, 1900, and 2100 h. Each heifer was observed for 2 hour-long periods, with both observation periods occurring on the same day. Visual observations were collected using a synchronized watch, and "start" and "stop" times were recorded for each rumination and feeding event. For correlations, data from CowManager SensOor tags and observations were averaged, so a single 1-h observation was provided per animal, reducing the potential for confounding repeated measures being collected for each animal. Concordance correlations (CCC; epiR package; R Foundation for Statistical Computing, Vienna, Austria) and Pearson correlations (r; CORR procedure; SAS Institute Inc., Cary, NC) were used to calculate association between visual observations and technology-recorded behaviors. Visually observed rumination time was correlated with the CowManager SensOor (r = 0.63, CCC = 0.55). Visually observed feeding time was also correlated with the CowManager SensOor (r = 0.88, CCC = 0.72). The difference between technology-recorded data and visual observation was treated as the dependent variable in a mixed linear model (MIXED procedure of SAS). Time of day, age in months, and group were treated as fixed effects. Individual heifers were treated as random and repeated effects. The effects of time of day, age, and group on rumination and feeding times were not significant. The CowManager SensOor was more effective at recording feeding behavior than rumination behavior in dairy heifers. The CowManager SensOor can be used to provide relatively accurate measures of feeding time in heifers, but its rumination time function should be used with caution.

Oral hygiene, prevalence of gingivitis, and associated risk factors among pregnant women in Sarlahi District, Nepal.

BACKGROUND: The oral health status of pregnant women in low-resource communities such as Nepal has not been well characterized. This sub-population is also of specific interest given associations between poor oral health and adverse pregnancy outcomes previously documented in other settings. We explored relationships between gingivitis and risk factors among pregnant women in rural Nepal. METHODS: The design was a community-based, cross-sectional study in a sub-area of Sarlahi District, Nepal. Pregnant women < 26 weeks gestation underwent clinical periodontal exams conducted by community-based oral health workers. Exams included a full mouth assessment measuring bleeding on probing (BOP), probing depth (PD) (six sites per tooth), and gingival recession, the distance from the cemento-enamel junction to the free gingival margin (two direct sites per tooth). Data on participant risk factors were collected through household surveys, including demographic characteristics, oral health behaviors, care seeking, and health attitudes. Multivariable logistic regression modeling was used to assess relationships between gingivitis and risk factors. RESULTS: We enrolled 1452 participants, of which 40% (n = 582) had signs of clinical gingivitis and 60% (n = 870) clinical health. Average participant age was 23. Most participants (88%) had never received oral health care. Participants averaged 10% of sites with BOP with most (79%) having ≥1 site with BOP. Nine percent of participants had ≥1 site with PD ≥4 mm, although very few participants (0.7%) had sites with PD ≥5 mm. Few participants (13%) had any recession (≥1 mm). In the final adjusted model, odds of gingivitis increased by 3% for each year of age (aOR 1.03, 95% CI 1.00, 1.06) and were higher for women of short maternal stature (< 150 cm) (aOR 1.43, 95% CI: 1.14, 1.79) and among women reporting cost to be a barrier to seeking dental care (aOR 2.13, 95% CI: 1.09, 4.15). CONCLUSIONS: Gingivitis was common and associated with age, maternal stature, self-reported high cost of dental care, and other risk factors among pregnant women in rural Nepal. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01177111 (Nepal Oil Massage Study) and NCT02788786 (Pilot Trial).

Use of indirect calorimetry to evaluate utilization of energy in lactating Jersey dairy cattle consuming common coproducts.

The use of coproducts as an alternative feed source is a common practice when formulating dairy rations. A study using 12 multiparous (79 ± 16 d in milk; mean ± standard deviation) lactating Jersey cows was conducted over 5 mo to evaluate the effects of dried distillers grains with solubles (DDGS) or canola meal on milk and gas production. A replicated 4 × 4 Latin square design was used to compare 4 dietary treatments. Treatments comprised a control (CON) containing no coproducts, a treatment diet containing 10% (dry matter basis) low-fat DDGS (LFDG), a treatment diet containing 10% high-fat DDGS (HFDG), and a 10% canola meal (CM) treatment. The crude fat content of the LFDG, HFDG, and CM treatments was 6.05 ± 0.379, 10.0 ± 0.134, and 3.46 ± 0.085%, respectively. Coproducts were included in partial replacement for corn and soybean meal. Indirect headbox-style calorimeters were used to estimate heat production. Dry matter intake and milk yield were similar between all treatments, averaging 17.4 ± 0.56 kg/d and 24.0 ± 0.80 kg, respectively. Milk urea N was affected by treatment and was highest in CON (20.6 mg/dL; 18.0, 19.9, and 18.1 ± 0.62 mg/dL in LFDG, CM, and HFDG, respectively). Heat production per unit of metabolic body weight tended to be affected by treatment and was lowest for CON, and diets containing coproducts were not different (192, 200, 215, and 204 ± 5.91 kcal/kg of metabolic body weight for CON, LFDG, CM, and HFDG, respectively). The concentration of metabolizable energy was affected by dietary treatment; specifically, HFDG did not differ from CON but was greater than LFDG and CM (2.58, 2.46, 2.29, and 2.27 ± 0.09 Mcal/kg for HFDG, CON, LFDG, and CM, respectively). The concentration of net energy balance (milk plus tissue) tended to be affected by dietary treatment; HFDG did not differ from either CON or LFDG, but it was higher than CM (1.38, 1.36, 1.14, and 1.06 ± 0.11 Mcal/kg for HFDG, CON, LFDG, and CM, respectively). Results of this study indicate that milk production and dry matter intake were not affected by feeding common coproducts and that differences may result in whole-animal energy use; fat content of DDGS is a major factor affecting this.

Oral health knowledge, behavior, and care seeking among pregnant and recently-delivered women in rural Nepal: a qualitative study.

BACKGROUND: Oral health behavior and attitudes of pregnant women in low-income countries are rarely examined, yet should be considered when designing preventative or therapeutic studies to reduce burden of oral diseases. We aimed to understand dental care-seeking behavior, as well as oral health knowledge and attitudes of oral health among pregnant women in rural Nepal. METHODS: Semi-structured in-depth interviews (n = 16) and focus group discussions (3 groups, n = 23) were conducted among pregnant and recently-delivered women in Sarlahi, Nepal. Transcripts were translated from the local language to English then analyzed using a hybrid approach to thematic coding with Atlas.ti version 7. RESULTS: Women felt confident describing the signs and symptoms of tooth decay and gum disease, but were not knowledgeable about where to receive care for tooth and/or gum pain and relied heavily on the knowledge of their community. Some women used a toothbrush and toothpaste at least once a day to clean their teeth, but many reported the traditional use of a branch of a local shrub or tree as their teeth cleaning instrument. Women suggested a willingness to consider using an oral rinse throughout pregnancy, perceiving that it might have a positive impact on infant health. CONCLUSIONS: Future studies should focus on providing adequate and sustainable resources for pregnant women in Nepal and other low income settings to engage in good oral health behaviors (possibly supported through community-based workers), to maintain dental hygiene, and to access qualified dentists as a means of improving their oral health. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01177111 (Nepal Oil Massage Study) and NCT02788786 (Pilot Trial).

The Important Role and Implications of Citrate in the Composition, Structure, and Function of Oral/Periodontal/Craniofacial Tissues.

High citrate concentration is a major component in the structure of craniofacial bone, teeth and periodontal tissues of humans and other osteovertebrates. It is now established that citrate incorporation into the apatite/collagen complex of bone is essential for the manifestation of the important biomechanical properties of bone; such as stability, strength, and resistance to fracture. The osteoblasts are specialized citrate-producing cells that provide the citrate incorporated in bone during osteogenic stem cell differentiation for production of new bone; "citration" that occurs in concert with mineralization. Dentin and cementum contain high citrate levels; as contrasted with low citrate in enamel. There exists no information regarding the status and source of incorporated citrate in dentin or in cementum. These are important issues relating to oral, periodontal, craniofacial structures. For example, repair of defects should include new tissue that exhibits the composition, structure, and biomechanical properties of the "normal" tissue; which cannot be achieved in the absence of citrate incorporation in the new tissues. Unfortunately, the presence and role of citrate in these tissues have been largely ignored and unrecognized over the past about 40 years by the dental and medical community. The intent of this review is to re-establish the interest and research regarding the important citrate relationships and issues; with focus on related interests in dentistry.

Developing a New Generation of Antimicrobial and Bioactive Dental Resins.

Dental caries is prevalent, and secondary caries causes restoration failures. This article reviews recent studies on developing a new generation of bioactive resins with anticaries properties. Extensive effects were made to develop new antimicrobial composites, bonding agents, and other resins containing quaternary ammonium methacrylates to suppress plaque buildup and bacterial acid production. The effects of alkyl chain length and charge density and the antimicrobial mechanisms for chlorhexidine, nano-silver, quaternary ammonium methacrylates, and protein-repellent agents were discussed. Synergistic effects of contact-killing and protein-repellent properties were shown to yield the greatest biofilm-inhibition effects. The combination of antimicrobial, protein-repellent, and calcium phosphate nanoparticle remineralization was suggested to provide maximal anticaries effects. In addition, for use orally, cytotoxicity and biocompatibility were important considerations for the new bioactive materials. Furthermore, rather than kill all bacteria, it would be more desirable to modulate the oral biofilm compositions via bioactive resins to suppress cariogenic/pathogenic species and promote benign species. For widespread clinical use of the new antimicrobial and therapeutic materials, whether they would induce bacterial drug resistance needs to be determined, which requires further study. Nonetheless, the new generation of bioactive anticaries resins with therapeutic and biofilm acid-inhibiting properties has the potential to substantially benefit oral health.

Apical periodontitis and incident cardiovascular events in the Baltimore Longitudinal Study of Ageing.

AIM: To evaluate whether the presence of apical periodontitis (AP), root canal treatment (RCT) and endodontic burden (EB) - as the sum of AP and RCT sites - were associated with long-term risk of incident cardiovascular events (CVE), including cardiovascular-related mortality, using data on participants in the Baltimore Longitudinal Study of Ageing (BLSA). METHODOLOGY: This retrospective cohort included 278 dentate participants in the BLSA with complete medical and dental examinations. Periodontal disease (PD) and missing teeth were recorded. The total number of AP and RCT sites was determined from panoramic radiographs. EB was calculated as the sum of AP and RCT sites. Oral inflammatory burden (OIB) was calculated combining PD and EB. The main outcome was incident CVE including angina, myocardial infarction and cardiovascular-related death. Participants were monitored for up to 44 years (mean = 17.4± 11.1 years) following dental examination. Relative risks (RRs) were calculated through Poisson regression models, estimating the relationship between AP, RCT, EB, PD, OIB and incident CVE. RESULTS: Mean age at baseline was 55.0 ±16.8 years and 51.4% were men. Sixty-two participants (22.3%) developed CVE. Bivariate analysis showed that PD, EB, number of teeth and OIB were associated with incident CVE. Multivariate models, adjusted for socio-demographic and medical variables, showed that age ≥60 years (RR = 3.07, 95% CI =1.68-5.62), hypertension (RR = 2.0, 95% CI = 1.16-3.46) and EB ≥3 (RR = 1.77, 95% CI = 1.04-3.02) were independently associated with incident CVE. The association between OIB and incident CVE was reduced to nonsignificance after adjustments (RR = 1.97, 95% CI = 0.83-4.70). CONCLUSIONS: EB in midlife was an independent predictor of CVE amongst community-dwelling participants in the BLSA. Prospective studies are required to evaluate cardiovascular risk reduction with the treatment of AP.

Impact of NADiA ProsVue PSA slope on secondary treatment decisions after radical prostatectomy.

BACKGROUND: Selecting appropriate candidates for postprostatectomy radiotherapy is challenging, because adverse pathological features cannot accurately predict clinical recurrence. Biomarkers that identify residual disease activity may assist clinicians when counseling patients on the risks, benefits and costs of secondary treatment. NADiA ProsVue PSA slope results ≤2.0 pg ml(-1) month(-1) are predictive of a reduced risk of clinical recurrence; however, its clinical utility has not yet been studied. METHODS: We prospectively enrolled men treated by radical prostatectomy in a multicenter, institutional review board-approved clinical trial. At postsurgical follow-up, investigators (N=17) stratified men into low-, intermediate- or high-risk groups for prostate cancer recurrence based on clinicopathological findings and other factors. Investigators documented their initial treatment plan for each subject and serially collected three serum samples for ProsVue testing. After the ProsVue result was reported, investigators recorded whether or not the initial treatment plan was changed. The proportion of cases referred for secondary treatment before and after ProsVue was reported, and the significance of the difference determined. RESULTS: Complete assessments were reported for 225 men, 128 (56.9%) of whom were stratified into intermediate- and high-risk groups. Investigators reported that they would have referred 41/128 (32.0%) at-risk men for secondary treatment. However, after results were known, they referred only 15/128 (11.7%) men. The difference in proportions (-20.3%, 95% confidence interval (CI) -29.9 to -10.3%) is significant (P<0.0001). Odds of a referral was significantly reduced after results were reported (odds ratio 0.28, 95% CI 0.15-0.54, P<0.0001). CONCLUSIONS: Knowledge of a ProsVue result had significant impact on the final treatment plan. A ProsVue result ⩽2.0 pg ml(-1) month(-1) significantly reduced the proportion of men at risk of recurrence who otherwise would have been referred for secondary treatment.

Differential gender effects of a reduced-calorie diet on systemic inflammatory and immune parameters in nonhuman primates.

BACKGROUND AND OBJECTIVE: Dietary manipulation, including caloric restriction, has been shown to impact host response capabilities significantly, particularly in association with aging. This investigation compared systemic inflammatory and immune-response molecules in rhesus monkeys (Macaca mulatta). MATERIAL AND METHODS: Monkeys on continuous long-term calorie-restricted diets and a matched group of animals on a control ad libitum diet, were examined for systemic response profiles including the effects of both gender and aging. RESULTS: The results demonstrated that haptoglobin and alpha1-antiglycoprotein levels were elevated in the serum of male monkeys. Serum IgG responses to Campylobacter rectus, Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were significantly elevated in female monkeys. While only the antibody to Fusobacterium nucleatum was significantly affected by the calorie-restricted diet in female monkeys, antibody levels to Prevotella intermedia, C. rectus and Treponema denticola demonstrated a similar trend. CONCLUSION: In this investigation, only certain serum antibody levels were influenced by the age of male animals, which was seemingly related to increasing clinical disease in this gender. More generally, analytes were modulated by gender and/or diet in this oral model system of mucosal microbial challenge.

Trends in embryo transfer practices and multiple gestation for IVF procedures in the USA, 1996-2002.

BACKGROUND: Increasing use of IVF in the USA has been a major contributor to the rising national multiple birth rate. Many have advocated that reducing the number of embryos transferred is essential for addressing the IVF-associated multiple birth problem. METHODS: A population-based sample of 506 072 IVF transfers performed in the USA in 1996-2002 was used to investigate trends in embryo transfer practices and to determine whether any changes in practice patterns have impacted the multiple gestation risk associated with IVF. RESULTS: The proportion of procedures in which >or=3 embryos were transferred declined significantly for most patient groups between 1996 and 2002. However, declines for some groups were not sizeable (from 79 to 73% and from 76 to 71% for fresh, non-donor procedures among women aged 38-40 and 41-42 years respectively) and transferring >or=3 embryos remained the norm for all groups. As of 2002, single embryo transfer had not increased for most groups and remained uncommon. Some declines in overall multiple gestation rates were observed, although multiple gestation risk associated with 2 embryos transferred increased significantly for all groups. CONCLUSIONS: Despite changes in embryo transfer practices, multiple gestation risk remains high, in part due to increased multiple gestation rates associated with the transfer of two embryos.

Multiple-birth risk associated with IVF and extended embryo culture: USA, 2001.

BACKGROUND: Multiple births are associated with serious adverse infant and maternal outcomes. The objective of this study was to assess the multiple-birth risk (MBR) associated with IVF and determine whether the risk is impacted by stage of embryo development at transfer. METHODS: A population-based sample of 50 819 IVF transfers utilizing day 3 or day 5 embryos performed in the USA in 2001 on women aged 20-40 years was used to assess MBR and live-birth rate (LBR), stratified by patient age, supernumerary embryo availability, and number of embryos transferred. RESULTS: Although significantly more day 5 than day 3 transfers used < or =2 embryos (69.2 versus 27.7%), the former were not associated with decreased MBR. MBR was high when >1 embryo was transferred, irrespective of embryo development stage. LBR were generally maximized with 2 embryos transferred, and for some (day 5 transfers, patients aged 35-37 years) with one embryo. Electing to transfer a single day 5 embryo appeared efficacious for some patients: women aged 20-37 years with supernumerary embryos cryopreserved had LBR of 31.6-39.5%. CONCLUSIONS: MBR is high when > or =2 embryos are transferred. Single embryo transfer is the only way to prevent many multiple births and associated adverse health outcomes.

15-PGJ2, but not thiazolidinediones, inhibits cell growth, induces apoptosis, and causes downregulation of Stat3 in human oral SCCa cells.

Activation of peroxisome proliferator-activated receptor gamma (PPARgamma) has been linked to induction of differentiation, cell growth inhibition and apoptosis in several types of human cancer. However, the possible effects of PPARgamma agonists on human oral squamous cell carcinoma have not yet been reported. In this study, treatment with 15-deoxy-Delta(12,14)-PGJ(2) (15-PGJ(2)), a natural PPARgamma ligand, induced a significant reduction of oral squamous cell carcinoma cell growth, which was mainly attributed to upregulation of apoptosis. Interestingly, rosiglitazone and ciglitazone, two members of the thiazolidinedione family of PPARgamma activators, did not exert a growth inhibitory effect. Given the critical role that the oncogene signal transducer and activator of transcription 3 (Stat3) plays in head and neck carcinogenesis, its potential regulation by PPARgamma ligands was also examined. Treatment of oral squamous cell carcinoma cells with 15-PGJ(2) induced an initial reduction and eventual elimination of both phosphorylated and unphosphorylated Stat3 protein levels. In contrast, other PPARgamma did not induce similar effects. Our results provide the first evidence of significant antineoplastic effects of 15-PGJ(2) on human oral squamous cell carcinoma cells, which may be related to downmodulation of Stat3 and are at least partly mediated through PPARgamma-independent events.

Testosterone stimulates proliferation and inhibits interleukin-6 production of normal and hereditary gingival fibromatosis fibroblasts.

Hereditary gingival fibromatosis (HGF) is a rare oral condition characterized by a slow and progressive enlargement of the gingiva, involving both the maxilla and mandible. In vitro, HGF fibroblasts demonstrate a proliferative index significantly higher than fibroblasts from normal gingiva (NG). The objective of this study was to determine the effect of dihydrotestosterone on the proliferation of gingival fibroblasts derived from patients with HGF (n = 4) and from four healthy individuals. Additionally, we analyzed the effect of dihydrotestosterone on interleukin-6 (IL-6) production and determined the expression levels of androgen receptors in NG and HGF fibroblasts. Gingival fibroblasts from NG and HGF were incubated with increasing concentrations of dihydrotestosterone with or without androgen blockers, and cultured for 24 h, and the proliferation index was determined by automated cell counter. IL-6 production, in this system, was quantified using a "capture" enzyme-linked immunosorbent assay (ELISA). Semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to measure the mRNA expression of androgen receptors. The results indicated that dihydrotestosterone simultaneously downregulates the production of IL-6 and upregulates the cell proliferation. Finasteride and cyprosterone acetate, two anti-androgens, partially reversed these effects. Androgen receptor mRNA expression was identified in both NG and HGF fibroblasts; however, the levels in NG were higher than those observed in HGF. These results show that testosterone coordinates the proliferation and production of IL-6 of normal and HGF fibroblasts.

Hybridization cross-reactivity within homologous gene families on glass cDNA microarrays.

Glass cDNA microarrays can be used to profile the expression of thousands of gene targets in a single experiment. However, the potential for hybridization cross-reactivity needs to be considered when interpreting the results. Here, we describe hybridization experiments with a model array representing four distinct functional classes (families): chemokines, cytochrome P-450 isozymes, G proteins, and proteases. The cDNA clones selected for this array exhibited pairwise sequence identities ranging from 55% to 100%, as determined by a homology scoring algorithm (LALIGN). Targets for microarraying were amplified by PCR and spotted in 4-fold replication for signal averaging. One designated target from each family was further amplified by PCR to incorporate a T7 promoter sequence for the production of synthetic RNA transcripts. These transcripts were used to generate fluorescent hybridization probes by reverse transcription at varying input concentrations. As expected, hybridization signals were highest at the matching target elements. Targets containing less than 80% sequence identity relative to the hybridization probe sequences showed cross-reactivities ranging from 0.6% to 12%. Targets containing greater than 80% identity showed higher cross-reactivities (26%-57%). These cross-reactive signals were analyzed for statistical correlation with the length of sequence overlap, percent sequence identity, and homology score determined by LALIGN. Overall, percent sequence identity was the best predictor of hybridization cross-reactivity. These results provide useful guidelines for interpreting glass cDNA microarray data.

Risk of multiple birth associated with in vitro fertilization using donor eggs.

Multiple birth, which is associated with adverse fetal, infant, and maternal outcomes, is increasingly related to the use of in vitro fertilization (IVF). Among women undergoing IVF who use their own eggs, greater maternal age is associated with decreased risk of multiple birth; using donor eggs from younger women may negate this age effect. Data from 6,936 IVF procedures performed in the United States in 1996-1997 on women aged 35-54 years who used donor eggs were analyzed to assess the effect of maternal age, number of embryos transferred, and cryopreservation of extra, nontransferred embryos (an indicator of higher embryo quality) on risk of multiple birth. Greater maternal age did not decrease multiple-birth risk. Rates of multiple birth were related to number of embryos transferred and whether extra embryos had been cryopreserved, and they were high compared with those of IVF patients the same age who had used their own eggs. Among women who had extra embryos cryopreserved, transferring more than two embryos increased multiple-birth risk, with no corresponding increase in the chance for a livebirth. These results highlight the need to consider the age of the donor and embryo quality when making embryo transfer decisions involving use of donor eggs.

DNA exhibits multi-stranded binding recognition on glass microarrays.

In the course of exploring the hybridization properties of glass DNA microarrays, multi-stranded DNA structures were observed that could not be accounted for by classical Watson-Crick base pairing. Non-denatured double-stranded DNA array elements were shown to hybridize to single-stranded (ss)DNA probes. Similarly, ssDNA array elements were shown to bind duplex DNA probes. This led to a series of experiments demonstrating the formation of multi-stranded DNA structures on the surface of microarrays. These structures were observed with a number of heterogeneous sequences, including both purine and pyrimidine bases, with shared sequence identity between the ssDNA and one of the duplex strands. Furthermore, we observed a strong binding preference near the ends of duplexes containing a 3'-homologous strand. We suggest that such binding interactions on cationic solid surfaces could serve as a model for a number of biological processes mediated through multi-stranded DNA.

Guided bone regeneration for dehiscence and fenestration defects on implants using an absorbable polymer barrier.

BACKGROUND: Guided bone regeneration (GBR) using a non-absorbable barrier has provided clinicians the ability to place implants in sites compromised by insufficient bone, including immediate extraction sites. Recent evidence suggests that successful GBR outcomes may be possible using bioabsorbable polymer barriers. METHODS: This report presents a case series of 9 patients with 8 fenestration and 3 dehiscence defects on implants consecutively treated with GBR. A bioabsorbable polymer barrier of poly(DL-lactide) was used in conjunction with a composite graft of freeze-dried bone allograft (FDBA)/demineralized freeze-dried bone allograft (DFDBA) mixed in a ratio of 1:1. Second-stage surgeries were performed at 4 to 8.5 months (5. 7 months average) post-placement. Biopsy material from 2 sites was obtained while exposing the implant for healing abutment connection. RESULTS: Ten of the 11 defects (90.9%) achieved complete coverage of the osseous defects. Histologic evaluations revealed the formation of viable bone, frequently in close amalgamation with residual graft particles. CONCLUSION: These case reports suggest that a poly(DL-lactide) polymer can be used as a physical barrier with a composite bone replacement graft to achieve successful GBR results of dehiscence/fenestration defects when placing implants.

Alveolar ridge and sinus augmentation utilizing platelet-rich plasma in combination with freeze-dried bone allograft: case series.

BACKGROUND: Alveolar bone regeneration is frequently necessary prior to placement of implants. Efforts to improve wound healing have focused on factors that may enhance bone formation following guided bone regeneration (GBR) techniques alone or in combination with bone replacement graft materials. Recent reports suggest that platelet-rich plasma (PRP), presumably high in levels of peptide growth factors, may enhance the formation of new bone when used in combination with autogenous graft material. METHODS: In this report, the clinical and radiographic results are presented on 15 consecutively treated patients using autologous PRP in combination with freeze-dried bone allograft (FDBA) for sinus elevation and/or ridge augmentation. FDBA and PRP (0.5 g/2cc PRP) were mixed and placed as a composite graft material. A gel formed by mixing autologous thrombin-rich plasma with PRP (1:4 ratio) was used to cover the graft material. Core biopsies of grafted areas were obtained in several patients as part of implant site preparation and were evaluated histologically to determine site maturation. RESULTS: Of 36 implant fixtures, 32 (89%) were considered clinically successful demonstrating complete bone coverage of the implant, no mobility, and a normal radiographic appearance at the time of re-entry and 12 months post-implant exposure. Four implants were removed due to mobility at the time of surgical exposure. Histologic evaluation of biopsy specimens revealed numerous areas of osteoid and bone formation around FDBA particles, with no evidence of inflammatory cell infiltrate. CONCLUSIONS: These clinical and histological findings suggest that ridge augmentation and sinus grafting with FDBA in combination with PRP provide a viable therapeutic alternative for implant placements. Future studies are necessary to determine whether PRP enhances new bone formation or maturation with bone replacement allografts.

Antitumor and antimetastatic activity of ribozymes targeting the messenger RNA of vascular endothelial growth factor receptors.

Chemically stabilized hammerhead ribozymes are nuclease-resistant, RNA-based oligonucleotides that selectively bind and cleave specific target RNAs. Due to their potential for specifically inhibiting gene expression, ribozymes are being investigated for therapeutic applications as well as for the elucidation of gene function. In particular, we have investigated ribozymes that target the mRNA of the vascular endothelial growth factor (VEGF) receptors because VEGF signaling is an important mediator of tumor angiogenesis and metastasis. Here we report pharmacodynamic studies testing anti-Flt-1 (VEGFR-1) and anti-KDR (VEGFR-2) ribozymes in animal models of solid tumor growth and metastasis. Ribozymes targeting either Flt-1 or KDR significantly inhibited primary tumor growth in a highly metastatic variant of Lewis lung carcinoma. However, only treatment with the anti-Flt-1 ribozyme resulted in a statistically significant and dose-dependent inhibition of lung metastasis in this model. The anti-Flt-1 ribozyme was then tested in a xenograft model of human metastatic colorectal cancer in which significant inhibition of liver metastasis was observed. Taken together, these data represent the first demonstration that synthetic ribozymes targeting VEGF receptor mRNA reduced the growth and metastasis of solid tumors in vivo.