Opioid analgesia in necrotizing pancreatitis: Incidence and timing of a hidden crisis.

BACKGROUND: Rates of opioid usage during necrotizing pancreatitis (NP) disease course are unknown. We hypothesized that a significant number of NP patients were prescribed opioid analgesics chronically. METHODS: Single institution IRB-approved retrospective study of 230 NP patients treated between 2015 and 2019. RESULTS: Data were available for 198/230 (86%) patients. 166/198 (84%) were discharged from their index hospitalization with a prescription for an opioid. At the first clinic visit following hospitalization, 110/182 (60%) were using opioids. Six months after disease onset, 72/163 (44%) continued to require opioids. At disease resolution, 38/144 (26%) patients remained on opioid medications. The rate of active opioid prescriptions at six months after disease onset declined throughout the period studied from 68% in 2015 to 39% in 2019. CONCLUSIONS: Opioid prescriptions are common in NP. Despite decline over time, 1 in 4 patients remain on opioids at disease resolution. These data identify an opportunity to adjust analgesic prescription practice in NP patients.

Evaluating adaptive co-management as conservation conflict resolution: Learning from seals and salmon.

By linking iterative learning and knowledge generation with power-sharing, adaptive co-management (ACM) provides a potential solution to resolving complex social-ecological problems. In this paper we evaluate ACM as a mechanism for resolving conservation conflict using a case study in Scotland, where seal and salmon fishery stakeholders have opposing and entrenched objectives. ACM emerged in 2002, successfully resolving this long-standing conflict. Applying evaluation approaches from the literature, in 2011 we interviewed stakeholders to characterise the evolution of ACM, and factors associated with its success over 10 years. In common with other ACM cases, triggers for the process were shifts in slow variables controlling the system (seal and salmon abundance, public perceptions of seal shooting), and exogenous shocks (changes in legal mandates, a seal disease outbreak). Also typical of ACM, three phases of evolution were evident: emerging local leadership preparing the system for change, a policy window of opportunity, and stakeholder partnerships building the resilience of the system. Parameters maintaining ACM were legal mechanisms and structures, legal power held by government, and the willingness of all stakeholders to reach a compromise and experiment with an alternative governance approach. Results highlighted the critical role of government power and support in resolving conservation conflict, which may constrain the extent of local stakeholder-driven ACM. The evaluation also demonstrated how, following perceived success, the trajectory of ACM has shifted to a 'stakeholder apathy' phase, with declining leadership, knowledge exchange, stakeholder engagement, and system resilience. We discuss remedial actions required to revive the process, and the importance of long term government resourcing and alternative financing schemes for successful conflict resolution. Based on the results we present a generic indicator framework and participatory method for the longitudinal evaluation of ACM applied to conservation conflict resolution.

Comparison of double locking plate constructs with single non-locking plate constructs in single cycle to failure in bending and torsion.

OBJECTIVE: To evaluate the biomechanical properties of single 3.5 mm broad dynamic compression plate (DCP) and double 3.5 mm String-of-Pearls (SOP) plate constructs in single-cycle bending and torsion. We hypothesized that the double SOP construct would outperform the broad DCP in both bending and torsional testing. METHODS: Broad DCP plates and double 3.5 mm SOP plates were secured to a previously validated bone model in an effort to simulate bridging osteosynthesis. Constructs were tested in both four-point bending and torsional testing. RESULTS: The double SOP constructs had significantly greater bending stiffness, bending strength, bending structural stiffness, and torsional stiffness when compared to the broad DCP constructs. The single broad DCP constructs had significantly higher yield torque and yield angles during torsional testing. CLINICAL RELEVANCE: Although the in vitro mechanical performance of the double SOP construct was significantly greater than the single broad DCP constructs under bending loads, the actual differences were small. Various patient, fracture, and implant factors must be considered when choosing an appropriate implant for fracture fixation.

The effects of a novel lateral extracapsular suture system on the kinematics of the cranial cruciate deficient canine stifle.

OBJECTIVE: To evaluate the relative position of the femur and tibia in cranial cruciate ligament-intact stifles, cranial cruciate ligament-deficient stifles, and cruciate-deficient stifles following lateral extracapsular suture system (LESS) stabilization under load at specific joint angles. STUDY DESIGN: In vitro biomechanical study. METHODS: Twenty pelvic limbs from 11 dogs were used to evaluate the relative position of the femur and tibia between three stifle conditions (cranial cruciate ligament-intact, cranial cruciate ligament-deficient, and LESS-stabilized) at a load of 30% of body weight and stifle angles of 125°, 135°, and 145° using electromagnetic tracking sensors. RESULTS: Cranial cruciate ligament-deficient stifles had significantly greater (p <0.0001) cranial displacement and internal rotation of the tibia relative to the femur than cranial cruciate ligament-intact or LESS stifles at all stifle angles. Cranial displacement of the tibia relative to the femur for cranial cruciate ligament-intact and LESS stifles were not significantly different from one another at a stifle angle of 125°, but were significantly different at stifle angles of 135° (p = 0.0182) and 145° (p = 0.0012). There was no significant difference in internal rotation of the tibia relative to the femur between the cranial cruciate ligament-intact and LESS stifles at any of the stifle angles. CLINICAL SIGNIFICANCE: The LESS procedure effectively decreased cranial tibial displacement and eliminated internal rotation of the tibia relative to the femur in the cranial cruciate ligament-deficient stifles at stifle angles of 125°, 135°, and 145° in vitro.

A Value Chain Analysis of ghost nets in the Arafura Sea: identifying trans-boundary stakeholders, intervention points and livelihood trade-offs.

Lost or discarded fishing nets are a significant component of marine debris which has trans-boundary impacts in large marine ecosystems. Such 'ghost nets' cause the by-catch of marine fauna and require retrieval from coastlines where they wash up. Identifying the causes of discarded nets and feasible intervention points requires analysis of a complex value chain and the stakeholders within it, yet no studies have attempted this. In this paper we combine Value Chain Analysis, commonly applied to understand value-adding for a commodity, with elements of Life Cycle Assessment and social network analysis to examine the drivers, stakeholders, economic, environmental and social costs and benefits in the life of a trawl net. We use the Arafura Sea as a case study, which is shared by Indonesia, Papua New Guinea and Australia, and is the focus of a Trans-boundary Diagnostic Assessment (TDA) within the Arafura-Timor Seas Ecosystem Action program (ATSEA). We follow a trawl net through four sub-systems: manufacture of webbing in South Korea, fishing and loss by an Indonesian vessel, retrieval as ghost net on the northern Australian coastline by Indigenous rangers, and disposal or re-cycling as 'GhostNet Art' by Indigenous artists. Primary stakeholders along the value chain incur economic and social benefits, and economic and environmental costs. There is an anomaly in the chain between Indonesian fishermen and Indigenous rangers, artists and communities due to the lack of market linkages between these primary stakeholders. The first 'nexus of influence' where reductions in net losses and environmental costs can be achieved is through interactions between GhostNets Australia, the World Wide Fund for Nature and the Australian Government, which can influence Indonesian fishery management institutions and fishing crews. The second nexus is via the international art market which by publicising GhostNet Art can raise awareness amongst fish consumers about the impacts of ghost nets, and hence influence Indonesian fishing companies. GhostNets Australia is a key bridging organisation in the network, linking stakeholders across scales and sub-systems. Feasible preventative interventions are discussed to rectify the anomaly in the value chain. The importance of GhostNets Australia and ATSEA in the evolving adaptive co-management and trans-boundary governance of fisheries is highlighted. However, the prevention of ghost nets will result in trade-offs in benefits for the livelihoods of primary stakeholders. The utility of the method for analysing marine debris in TDAs, and ATSEA in particular, is discussed.

Effect of tibial insertion site for lateral suture stabilization on the kinematics of the cranial cruciate ligament deficient-stifle during early, middle and late stance: an in vitro study.

OBJECTIVE: To evaluate the effect of two tibial attachment sites for lateral suture stabilization (LSS) on the three-dimensional femorotibial translational and rotational movements of the cranial cruciate ligament- deficient canine stifle during the early, middle and late stance phases. STUDY DESIGN: In vitro biomechanical study: 32 hindlimbs from 16 canine cadavers. METHODS: Limbs were mounted in a testing jig and an electromagnetic tracking system was used to determine the three-dimensional femorotibial translational and rotational movements under 33% of body weight load during early, middle and late stance in the following sequence: cranial cruciate ligament-intact, cranial cruciate ligament-deficient and LSS with the distal anchor through the tibial tuberosity (LSSTT) or through the cranial eminence of the extensor groove (LSSEG). The proximal anchor point was the lateral femorofabellar ligament. RESULTS: Post-LSS stifle three-dimensional femorotibial translational and rotational movements were more comparable to normal than post-transection movements for both techniques. Both LSS techniques restored femorotibial movements in cranial cruciate ligament-deficient stifles to varying amounts but neither technique successfully restored normal three-dimensional femorotibial movements. The LSSEG improved femorotibial movements of the cranial cruciate ligament-deficient stifle in the medial-lateral direction and axial rotation but performed poorly in restoring femorotibial movements in the cranial-caudal direction as compared to the LSSTT. CLINICAL SIGNIFICANCE: Both the LSSTT and LSSEG techniques failed to completely restore normal three-dimensional femorotibial translational and rotational movements in cranial cruciate ligament-deficient stifles in vitro.

The effect of tibial tuberosity advancement and meniscal release on kinematics of the cranial cruciate ligament-deficient stifle during early, middle, and late stance.

OBJECTIVES: To evaluate the effect of tibial tuberosity advancement (TTA) and meniscal release on cranial-caudal and axial rotational displacement during early, middle and late stance phases in the canine cranial cruciate ligament- (CCL) deficient stifle. STUDY DESIGN: In vitro biomechanical study. METHODS: Eighteen pelvic limbs were evaluated for the effects of TTA on cranial-caudal displacement and axial rotation under a load equivalent to 30% bodyweight, and under the following treatment conditions: normal (intact CCL), CCL deficient, TTA-treated (CCL deficient + TTA), and meniscal release (TTA treated + meniscal release). The limbs were evaluated in the early, middle, and late stance phases using electromagnetic tracking sensors to determine cranial tibial displacement and tibial rotation relative to the femur. RESULTS: Transection of the CCL resulted in significant cranial tibial displacement during early, middle, and late stance (p < 0.0001) and significant internal rotation during early (p = 0.049) and middle stance (p = 0.0006). Performance of TTA successfully eliminated cranial tibial displacement in early, middle, and late stance (p <0.0001); however, the TTA was unsuccessful in normalizing axial rotation in middle stance (p = 0.030). Meniscal release had no effect on cranial-caudal or rotational displacement when performed in conjunction with the TTA. CLINICAL SIGNIFICANCE: Tibial tuberosity advancement effectively eliminates cranial tibial displacement during early, middle and late stance; however, TTA failed to provide rotational stability in mid-stance.

Measurements of the equilibrium size of supersaturated aqueous sodium chloride droplets at low relative humidity using aerosol optical tweezers and an electrodynamic balance.

An approach for examining the hygroscopicity of single aerosol particles over a broad range in relative humidity (RH) using aerosol optical tweezers is presented and compared with measurements made using an electrodynamic balance. In particular, benchmark measurements on aqueous sodium chloride aerosol are presented over the RH range 45-75% (293 K), a RH range that had not previously been explored with aerosol optical tweezers. Measurements of the variation in equilibrium wet droplet size with RH are made using cavity-enhanced Raman scattering, with an accuracy of 1 nm in the determination of the wet particle radius. The full range of optical tweezers experimental measurements (including previous dual trapping comparative studies approaching a saturation relative humidity of 100%) are compared with determinations using other experimental techniques and with a range of model treatments. An assessment of the models and all experimental data for estimating the equilibrium size of a sodium chloride droplet suggests that the size can be predicted with an accuracy of better than 0.1% over the RH range 48-100%. Discrepancies between different measurements lead to an increase in uncertainty above 1% below an RH of 48% as efflorescence is approached. The optical tweezers' measurements of equilibrium size consistently agree with model predictions to within an error of 1% (<50 nm for the size range explored here) and mostly with an error of less than +/-0.1%. These data demonstrate the highly accurate nature of measurements of thermodynamic equilibrium size by aerosol optical tweezers and suggest that this approach may be used to investigate the competition between thermodynamic and kinetic factors in governing aerosol particle size over the full RH range.

Effect of healthcare on mortality: trends in avoidable mortality in Australia and comparisons with Western Europe.

OBJECTIVES: Using the concept of avoidable mortality, international studies suggest that healthcare has been effective in reducing mortality. This paper provides an analysis of avoidable mortality in Australia and compares trends with those of Western Europe. METHODS: Using unit-record mortality data, we calculated avoidable mortality rates in Australia for 1968-2001. We partitioned avoidable causes into three categories: those amenable to medical care; those mainly responsive to health policy; and ischaemic heart disease. We used Poisson regression to model the trends. We compared trends with those of nine European countries using published data. RESULTS: Total avoidable death rates fell by 68% in females and 72% in males. The corresponding non-avoidable death rates fell by 35 and 33%. The annual declines in avoidable mortality rates were: 3.47% [95% confidence intervals (CI) 3.44-3.50%] in males and 3.89% (95% CI 3.86-3.91%) in females. For non-avoidable mortality rates, the annual declines were 1.09% (95% CI 1.05-1.13%) and 0.95% (95% CI 0.92-0.98%), respectively. In females, declines in death rates from causes amenable to medical care contributed 54% to the decline in avoidable mortality rates, ischaemic heart disease contributed 45%, and causes responsive to health policy intervention contributed 1%. In males, the corresponding contributions were 32, 57 and 11%. These rates, and the declines between 1980 and 1998, were comparable with selected European countries, with Australia's ranking improving over the period. CONCLUSION: Trends in avoidable mortality in Australia suggest that the Australian healthcare system has been effective in improving population health. Australia's experience compares favourably with that of Europe.

Should programmes for community-level meningococcal vaccination be considered in Australia? An economic evaluation.

BACKGROUND: Disease due to serogroup C Neisseria meningitidis is life-threatening and potentially preventable by vaccination. In 1999, the UK instigated mass vaccination after a sustained increase in serogroup C meningococcal disease. In the same year, Victoria, Australia experienced a similar change in disease epidemiology. It is timely to undertake an economic evaluation of options for community vaccination in Australia based on local data. METHODS: Cost-effectiveness and cost-benefit analyses of three options for use of polysaccharide vaccine were undertaken for a hypothetical population aged 15--19 years. Baseline analyses assumed 5 years' duration of vaccine protection following a single year of programme implementation. Sensitivity analyses of key variables were performed, including vaccine coverage and effectiveness, case fatality rate and the discount rate. Outcomes included the number of people vaccinated, cases averted, life-years saved and disability-adjusted life-years (DALY) averted. Cost-benefit analysis used lost earnings avoided as a measure of vaccination benefit. RESULTS: Vaccination of people aged 15--19 years in a defined population with a high rate of disease was the most cost-effective option. Compared with no vaccination and assuming 5 years' duration of protection and exclusion of direct cost savings, this resulted in a discounted cost per life-year saved of $23,623, a cost per DALY avoided of $21,097 and benefits exceeding costs in discounted terms. The 'break-even' incidence rate for this option with exclusion of direct cost savings was 14.0/100,000. CONCLUSIONS: Community use of polysaccharide vaccination may be cost effective in Australia under certain conditions. Economic evidence favours use of vaccination in well-defined populations with a high rate of disease. Policy decision-making also requires consideration of non-economic factors, including feasibility of implementation and risk perception by the community.

Meningococcal vaccination for adolescents? An economic evaluation in Victoria.

OBJECTIVE: To undertake an economic evaluation of the options for vaccination of adolescents using meningococcal polysaccharide vaccine based on Victorian data. METHODOLOGY: Cost-effectiveness and cost-benefit analyses of three options for vaccination were undertaken for hypothetical populations aged 15-19 years. Baseline analyses assumed a single year of programme implementation and vaccine protection of 5 years. Sensitivity analyses of key variables were performed. Outcomes included the number of people vaccinated, cases averted, life years saved and disability adjusted life years (DALY) averted. Lost earnings avoided were included as a measure of vaccination benefit in cost-benefit analyses. RESULTS: Vaccination of people in Years 10-12 (secondary school) and first year university within a defined population with a high rate of disease was the most cost-effective option. Excluding direct cost savings and compared with no vaccination, this resulted in a discounted cost per DALY avoided of $17646 and benefits exceeding costs in discounted terms. The 'break-even' incidence rate for this option in the cost-benefit analysis was 11.9/100000. CONCLUSIONS: Economic evidence favours the use of vaccination within well-defined populations with a high rate of disease.

Deficiency of Src homology 2-containing phosphatase 1 results in abnormalities in murine neutrophil function: studies in motheaten mice.

Neutrophils, an essential component of the innate immune system, are regulated in part by signaling pathways involving protein tyrosine phosphorylation. While protein tyrosine kinase functions in regulating neutrophil behavior have been extensively investigated, little is known about the role for specific protein tyrosine phosphatases (PTP) in modulating neutrophil signaling cascades. A key role for Src homology 2 domain-containing phosphatase 1 (SHP-1), a PTP, in neutrophil physiology is, however, implied by the overexpansion and inappropriate activation of granulocyte populations in SHP-1-deficient motheaten (me/me) and motheaten viable (me(v)/me(v)) mice. To directly investigate the importance of SHP-1 to phagocytic cell function, bone marrow neutrophils were isolated from both me/me and me(v)/me(v) mice and examined with respect to their responses to various stimuli. The results of these studies revealed that both quiescent and activated neutrophils from motheaten mice manifested enhanced tyrosine phosphorylation of cellular proteins in the 60- to 80-kDa range relative to that detected in wild-type congenic control neutrophils. MOTHEATEN: neutrophils also demonstrated increased oxidant production, surface expression of CD18, and adhesion to protein-coated plastic. Chemotaxis, however, was severely diminished in the SHP-deficient neutrophils relative to control neutrophils, which was possibly attributable to a combination of defective deadhesion and altered actin assembly. Taken together, these results indicate a significant role for SHP-1 in modulating the tyrosine phosphorylation-dependent signaling pathways that regulate neutrophil microbicidal functions.

Demography and dog-human relationships of the dog population in Zimbabwean communal lands.

Dogs are Zimbabwe's primary vector for rabies, and the majority live in communal lands (traditional agropastoralist rural areas). In 1994, a household questionnaire survey was conducted to provide baseline data on the demography and dog-human relationships of the dogs in the communal lands. The survey showed that all the dogs were owned, and there was no evidence of a feral population. They were unrestricted and semi-dependent on people. The numbers of dogs per capita varied little in each communal land, resulting in higher dog densities in communal lands with higher human densities, and indicating that people were not intolerant of dogs at higher densities. The population turnover was rapid: the life expectancy of the dogs was 1.1 years, the mean age 2.0 years, and 71.8 per cent died in their first year. The population was heavily skewed towards juveniles, with 40.8 per cent aged less than 12 months. Despite the high juvenile mortality, the population was growing by 6.52 per cent per annum. It was estimated that in 1994 there were 1.36 million dogs in communal lands.

Phagosomal maturation, acidification, and inhibition of bacterial growth in nonphagocytic cells transfected with FcgammaRIIA receptors.

Phagocytosis and killing of microbial pathogens by professional phagocytes is an essential component of the innate immune response. Recently, heterologous transfection of individual receptors into nonmyeloid cells has been used successfully to elucidate the early steps that signal phagosome formation. It is unclear, however, whether the vacuoles formed by such transfected cells are bona fide phagosomes, capable of fusion with endomembranes, of luminal acidification, and of controlling the growth of microorganisms. The aim of the current study was to determine whether COS-1 and Chinese hamster ovary cells, rendered phagocytic by expression of human FcgammaRIIA receptors, express the cellular machinery required to support phagosomal maturation. Immunolocalization studies demonstrated that early endosomes, as well as late endosomes and/or lysosomes, fuse sequentially with phagosomes in the transfectants. Microfluorescence ratio imaging of particles labeled with pH-sensitive dyes revealed that maturation of the phagosome was accompanied by luminal acidification. The drop in pH, which attained levels comparable to those reported in professional phagocytes, was prevented by inhibitors of vacuolar-type H(+)-ATPases. Optimal phagosomal acidification required elevation of cytosolic [Ca(2+)], suggesting that it results from fusion of endomembranes bearing proton pumps. Moreover, the transfected cells effectively internalized live bacteria. Opsonization was essential for bacterial internalization, implying that it occurred by FcgammaRIIA-mediated phagocytosis, as opposed to invasion. Uptake into phagolysosomes was associated with inhibition of bacterial growth, due at least in part to the low intraphagosomal pH. These studies indicate that the biochemical events that follow receptor-mediated particle internalization in cells transfected with FcgammaRIIA receptors closely resemble the process of phagosomal maturation in neutrophils and macrophages. FcgammaRIIA-transfected cells can, therefore, be used as a model for the study of additional aspects of phagocyte biology.

The short-term financial costs of abnormal Pap smears to women and government in Australia.

Using data collected from a private Canberra colposcopy service, we examined the direct costs, to women and government, of the gynaecological care of women with cervical cytological abnormalities and determine the potential savings of implementing the Commonwealth recommendations for the clinical care of women with screen-detected abnormalities. We performed a case note audit of 502 women who first attended a gynaecologist because of an abnormal Pap smear between 1 January 1989 and 30 April 1990. The smear resulting in their referral--their presenting smear--was categorised as No CIN (showing no evidence of cervical intraepithelial neoplasia), CIN 1, CIN 2 and CIN 3. The average costs to government (p for trend < 0.001) and women (p for trend = 0.006) increase as the presenting smear increases in severity; the median costs to government (p for trend < 0.001) and women (p for trend < 0.001) also rose with increasing cytological severity. Treatment of CIN 1 and No CIN accounted for half the costs incurred by government and women. Although costs increase with increasing severity of cytological abnormality, adherence to new Australian guidelines for the gynaecological care of women with screen-detected cervical abnormalities could result in substantial short-term savings to government and women.

Importance of MEK in neutrophil microbicidal responsiveness.

Exposure of neutrophils to inflammatory stimuli such as the chemoattractant FMLP leads to activation of responses including cell motility, the oxidative burst, and secretion of proteolytic enzymes. A signaling cascade involving sequential activation of Raf-1, mitogen-activated protein kinase (MEK), and extracellular signal regulated kinase (ERK) is also rapidly activated after agonist exposure. The temporal relationship between these events suggests that the kinases may be involved in triggering the effector functions, but direct evidence of a causal relationship is lacking. To assess the role of the MEK/ERK pathway in the activation of neutrophil responses, we studied the effects of PD098059, a potent and selective inhibitor of MEK. Preincubation of human neutrophils with 50 microM PD098059 almost completely (>90%) inhibited the FMLP-induced activation of MEK-1 and MEK-2, the isoforms expressed by neutrophils. This dose of PD098059 virtually abrogated chemoattractant-induced tyrosine phosphorylation and activation of ERK-1 and ERK-2, implying that MEKs are the predominant upstream activators of these mitogen-activated protein kinases. Pretreatment of neutrophils with the MEK antagonist inhibited the oxidative burst substantially and phagocytosis only moderately. In addition, PD098059 antagonized the delay of apoptosis induced by exposure to granulocyte-macrophage CSF. However, the effects of PD098059 were selective, as it failed to inhibit other responses, including chemoattractant-induced exocytosis of primary and secondary granules, polymerization of F-actin, chemotaxis, or activation of phospholipase A2. We conclude that MEK and ERK contribute to the activation of the oxidative burst and phagocytosis, and participate in cytokine regulation of apoptosis.

Volumetric changes following barrier regeneration procedures for the surgical management of grade II molar furcation defects in baboons: II. Bone, cementum, epithelium, and connective tissue.

In Part I, a computer imaging technique was used to measure the volumetric fill that occurred in surgically created grade II molar furcation defects after they had been treated using the principles of guided tissue regeneration. In Part II, the volumetric fill for each of the specific tissues comprising the defect fill (epithelium, connective tissue, bone, and cementum) was compared. The histologic material consisted of defects treated using one of three types of surgical treatment as well as untreated control sites. All volumetric measurements were expressed as a percentage of the original surgically created defect size, with 100% indicating complete healing of the defect. The results indicate that none of the defects achieved complete healing. Teeth receiving flap debridement had the most overall defect fill (79.50% comprised of 17.13% bone, 35.81% connective tissue, 37.35% epithelium, and 9.71% cementum). Teeth that received a biodegradable barrier showed a mean overall defect fill of 74.98% (7.41% bone, 47.13% connective tissue, 36.20% epithelium, and 9.26% cementum. Sites treated with an exclusion barrier showed 70.75% overall fill (9.63% bone, 40.89% connective tissue, 39.00% epithelium, and 10.48% cementum). The untreated control teeth showed a mean overall fill of 78.70% (5.56% bone, 59.11% connective tissue, 31.06% epithelium, and 4.27% cementum). No significant differences were found among teeth within the same animal and between treatment and controls. The following conclusions were drawn: (1) connective tissue comprised nearly one half of the total fill of the surgically created defects; (2) the percentage of new bone growth was significantly lower than anticipated; and (3) no significant differences were found among the treatment modalities and the untreated control sites for each of the specific tissue types.

Volumetric changes following barrier regeneration procedures for the surgical management of grade II molar furcation defects in baboons: I. Overall defect fill.

A computer imaging technique has been advocated for measuring the volumetric fill in furcation defects. Histologic material for this investigation was obtained from an animal study using five adult baboons (Papio anubis). The photographed histology was converted into digitized electronic information, and a computer calculated the overall volume of defect fill for the treated and the untreated control sites. All volumetric measurements were expressed as a percentage of the original surgically created defect size, with 100% indicating complete healing of the defect. The results indicate that none of the defects achieved complete healing. Teeth that had received flap debridement had the most overall defect fill (79.50%). Teeth that received a biodegradable barrier (Epi-Guide) showed a mean overall defect fill of 74.98%, while sites treated with an exclusion barrier (Gore-Tex) showed 70.75% overall fill. The untreated control teeth showed a mean overall fill of 78.70%. A variety of statistical tests revealed no significant differences among teeth within the same animal and between treatments and controls. The following conclusions were drawn: (1) digital imaging technology is a useful research tool for determining the volume of defect fill in surgically created grade II molar periodontal furcation defects in the baboon model; and (2) no significant differences were found among the treatment modalities and the untreated control sites.