Search

Insects are increasingly common in households, zoological collections, research, and food industries. Increased knowledge of insect health parameters is necessary to ensure proper welfare. The study goal was to develop a hemolymph collection technique and report hemolymph serum biochemical parameters for the thorny devil stick insect ( Eurycantha calcarata ). Clinically healthy adult stick insects (5 males and 14 females, 15.1-24.7 g) were enrolled. Four collection techniques were evaluated. Hemolymph collection was unsuccessful in males, but was successful in females by using a single technique. The insect was manually restrained in an elevated position and an 18-ga × 2.54-cm needle was used to puncture the membrane just caudal to the third pair of legs. With the puncture site directed ventrally, ≤1 ml of hemolymph was collected via gravity and allowed to visibly clot. The sample was then centrifuged, and the serum was separated. Serum samples were individually analyzed (Avian/Reptilian Profile Plus, VetScan VS2, Abaxis, Inc, Union City, CA 94587, USA). Fourteen samples (0.2-1.0 ml) were collected from 14 females. Median (minimum-maximum) parameters included the following: aspartate aminotransferase 12 (0-45) U/L, creatinine kinase 25 (0-76) U/L, uric acid 7.5 (3.1-13.7) mg/dl, glucose 12 (8-22) mg/dl, calcium 18.6 (17.2-19.4) mg/dl, phosphorus 15.0 ( n = 1) or >30.0 ( n = 13) mg/dL, total protein 2.7 (1.6-2.9) g/dL, albumin 0.9 (0.2-1.2) g/dL, globulin 1.7 (1.6-1.8) g/dL ( n = 6) or not quantified ( n = 8), potassium 10.6 (9.0-11.8) mmol/L, sodium < 100 mmol/L, and bile acids 0 lmol/L. This is the first report of biochemistry parameters in clinically healthy female stick insects. Larger sample sizes are needed to establish statistically valid reference ranges. Hemolymph collection techniques for male stick insects warrant further investigation.

The Galapagos sea lion (Zalophus wollebaeki), an endemic and endangered pinniped, faces an increasing threat due to infectious diseases related to domestic animals. Dirofilaria immitis, the parasite responsible for canine heartworm disease, is one such threat, as canine infections on the archipelago have been documented. We used a canine heartworm antigen test kit to analyze the blood from 25 juvenile Galapagos sea lions for D. immitis. Two (8%) sea lions tested positive for D. immitis antigen. Using morphologic and genetic assessments, we evaluated 20 filarial-like worms collected from within the heart of an adult male Galapagos sea lion during a previous routine postmortem examination. The intracardiac worms were morphologically consistent with adult D. immitis, and sequence analysis of targeted PCR amplicons confirmed their identity. This is the first report of D. immitis infection in Galapagos sea lions, which could become a major health problem for these pinnipeds. Further studies are necessary to confirm the level of threat from this parasite; however, widespread adoption of routine heartworm testing, prevention, and treatment in the canine population, and the control of mosquitos, could potentially reduce the disease impact on this endangered pinniped species., (© Wildlife Disease Association 2023.)

Introduction: Hand wounds account for 35 to 51% of hand traumas. Damage to underlying anatomical structures depends on the location of the wound. The objective of this study is to describe the topographic distribution of hand wounds allowing for subsequent evaluation of the link between affected surface area and underlying lesion., Methods: We retrospectively reviewed the medical records of 1058 patients with a total of 1319 wounds over a period of 2 years. Wound location was described according to the cutaneous projection of IFSSH zones for flexors and extensors. Any associated deep lesions were evaluated. Topographical distribution was modeled graphically using a heat-map. We compared the proportion of underlying lesions between each cutaneous zone. Sub-group analysis for lesions' rate regarding zone groups were performed., Results: 58.9% of wounds were located on the palmar surface and 41.1% on the dorsal surface. 71% of wounds affected only the digits. The index finger was the most affected. The most damaged region was zone 2 for palmar wounds and zone 3 for dorsal wounds. 45.5% of wounds resulted in injury to a significant underlying anatomical structure. This frequency was 36.4% and 58.5% for palmar and dorsal wounds respectively. More than 50% of wounds in palmar zone 5 and dorsal zones 1, 3, 5, 6 and 7 presented at least one lesion. A lesion of major structure was more frequently found in palmar zone 5 (p <0.001). Dorsally, no zone predominated. Subgroup analysis for dorsal wounds revealed that wounds overlying joints had more major lesions including more tendons injuries and more articular violations with zone 3 presenting a rate of 68%., Conclusion: We provided the first graphical representation for the topographical distribution of hand wounds. Dorsal wounds have a higher association with injury to underlying structures. These results generally support surgical exploration of all hand wounds regardless of their location., Level of Evidence: IV Study type: Epidemiological study., Competing Interests: Declaration of Competing Interests None., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The Galapagos sea lion ( Zalophus wollebaeki ) is an endemic pinniped to the Galapagos archipelago, and like most wild mammals, is at risk for anemia due to trauma, infectious disease, and poor nutrition. This study evaluated the health status of 26 juvenile Galapagos sea lions on the island of San Cristobal prior to evaluating 100 crossmatch combinations. On evaluation, all but one sea lion had no major systemic abnormalities. Of the 100 crossmatches performed, 23% had minor reactions. The most significant reaction was weak macroscopic agglutination found in 4% of samples. The small percentage of agglutination reactions suggests a small proportion of naturally occurring alloantibodies in this species and may be consistent with a low risk of acute immune-mediated hemolytic transfusion reaction., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Gregory, Parker, Deresienski, Alarcón-Ruales, Muñoz-Pérez, Torres, Gavilanes, Lewbart and Páez-Rosas.)

The thorny devil stick insect ( Eurycantha calcarata ) is a common invertebrate maintained under human care. Blood (hemolymph) transfusions are a widely used therapeutic tool in other species, but investigation in terrestrial arthropods remains scarce. Study objectives were development and evaluation of a serum transfusion process in the thorny devil stick insect. Twenty-five clinically healthy adult insects (9.9-23.0 g) were enrolled and baseline body weights were collected. Hemolymph collection was not successful in males, thus, all were recipient only ( n = 12, MR). Females were divided into donor ( n = 4, FD) or donor and recipient ( n = 9, FDR) groups. Females were manually restrained and up to 1 mL of hemolymph was collected from the abdominal segment caudal to the proximal hindlimb using an 18 g hypodermic needle and passive collection via gravity. Hemolymph was quantified, centrifuged, and the serum separated. Insects were then injected superficially at the lateral aspect of the abdomen with 0.01 mL/g FD serum (MR), lactated Ringer's solution (LRS) equal to collected hemolymph volume (FD), or a combination of FDR serum and LRS equal to collected hemolymph volume (FDR). Response to stimulation, surface temperature, and righting reflex and mortality were serially assessed for up to 24 h and 7 days, respectively, following injection. In FD, median (range) injected LRS dose was 0.04 (0.03-0.06) mL/g. In FDR, median (range) injected serum, LRS, and combined serum and LRS dose was 0.03 (0.02-0.04), 0.01 (0-0.04), and 0.04 (0.02-0.06) mL/g, respectively. A mild temperature increase (maximum +2.9°C) (MR n = 10, FD n = 3, FDR n = 8) and delayed righting reflex (MR n = 4, FD n = 3, FDR n = 7) occurred in a subset of insects following injection. Two deaths occurred at 2 min ( n = 1, FDR) and 96 h ( n = 1, FD) post-injection. This is the first report of serum transfusions in thorny devil stick insects, and while largely successful, minor to severe transfusion reactions may occur., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Gregory, Heniff, Gorges, Lathan, Lewbart and Balko.)

The Turtle Rescue Team (TRT) at North Carolina State University College of Veterinary Medicine currently sees over 500 chelonian cases a year. Each turtle receives a thorough physical examination as the main evaluation of its health because further diagnostics are cost prohibitive in a donation-based facility. Thus, there is a need to further understand how a few economical diagnostics can evaluate the prognosis of chelonians. The objectives were to evaluate lactate, PCV, total solids, glucose, temperature, and HR as prognostic indicators in multiple chelonian species and to determine how the change in lactate concentrations over a 24 h period affects prognosis. Eastern box turtles ( Terrapene carolina carolina ), yellow-bellied sliders ( Trachemys scripta scripta ), river cooters ( Pseudemys concinna ), painted turtles ( Chrysemys picta ), and common snapping turtles ( Chelydra serpentina ) were evaluated because of prevalence of presentation to the TRT, differences in habitat, and differences in physiology. Hyperlactatemia, an increased lactate over 24 h when the initial lactate concentration was greater than 5 mM/L, and anemia were determined to be significant prognostic indicators of mortality for all turtles, and hypoglycemia was a significant prognostic indicator of mortality for male turtles ( P < 0.05).

Ketorolac is a non-steroidal anti-inflammatory drug administered as an analgesic in humans. It has analgesic effects comparable to opioids but without adverse effects such as respiratory depression or restrictions because of controlled drug status. We designed this study to examine the potential of ketorolac as an analgesic for sea turtle rehabilitative medicine. Our objective was to determine the pharmacokinetics of a single 0.25 mg/kg intramuscular dose of ketorolac in a population of 16 captive-raised juvenile loggerhead sea turtles (Caretta caretta). A sparse sampling protocol was utilized, and blood samples were collected for 12 hours after administration of ketorolac. Samples were analyzed with high-pressure liquid chromatography (HPLC), and a nonlinear mixed effects model (NLME) was used to determine parameters for the population. With these methods, we identified a long elimination half-life (βT 1/2  = 11.867 hr) but a low maximum concentration (C MAX  = 0.508 µg/mL) and concentrations were below the level proposed to be therapeutic in humans (EC 50  = 0.1-0.3 μg/mL) for most of the collection period. We conclude that ketorolac may not be an appropriate long-term analgesic for use in loggerhead sea turtles at this dose; however, it may have some benefit as a short-term analgesic., (© 2021 John Wiley & Sons Ltd.)

Despite the frequency of mallet finger injuries, treatment options can often be costly, time-consuming, and ill-fitted. Three-dimensional (3D) printing allows for the production of highly customized and inexpensive splints, which suggests potential efficacy in the prescription of casts for musculoskeletal injuries. This study explores how the use of engineering concepts such as 3D printing and topology optimization (TO) can improve outcomes for patients. 3D printing enables the direct fabrication of the patient-specific complex shapes while utilizing finite element analysis and TO in the design of the splint allowed for the most efficient distribution of material to achieve mechanical requirements while reducing the amount of material used. The reduction in used material leads to significant improvements in weight reduction and heat dissipation, which would improve breathability and less sweating for the patient, greatly increasing comfort for the duration of their recovery., (Copyright: © 2020 Zolfagharian, et al.)

An os acromiale occurs when any of the primary ossification centres of the acromion fail to fuse with the basi-acromion. It is present in approximately 8% of individuals, and whilst the majority of these individuals are unaffected it can cause significant pain and disability. It can impact seemingly unrelated surgical intervention in the region such as subacromial decompression and reverse shoulder arthroplasty. A painful os acromiale can be both a diagnostic challenge, and difficult to manage. There remain a wide variety of surgical practices with variable outcomes achieved. We present an evidence-based discussion of the surgical techniques described to date in the literature, alongside a comprehensive review of the incidence and pathophysiology of os acromiale.This review was written after a comprehensive analysis of the literature to date relating to os acromiale. Particular focus was given to material examining surgical management techniques, and the condition's incidence across different population groups.Open reduction and internal fixation using cannulated screws, or tension band wiring have superior outcomes in the literature in the treatment of symptomatic os acromiale. There may be a biomechanical advantage of combining the two techniques. Preservation of large anterior deltoid attachment is necessary, with consideration being given to the local blood supply. There is likely no additional benefit from iliac crest vs local bone grafting. Research in this area remains of a low evidence level with small samples sizes. Appropriately powered clinical research of a higher-level evidence methodology is needed in order to differentiate further in the choice of surgical intervention. Cite this article: EFORT Open Rev 2019;4:525-532. DOI: 10.1302/2058-5241.4.180100., Competing Interests: ICMJE Conflict of interest statement: TMG reports consultancy to Evolutis and a patent planned, pending or issued for a shoulder apparatus system. PR and SAH declare no conflict of interest relevant to this work.

Background: Shoulder arthroplasty, in its different forms (hemiarthroplasty, total shoulder arthroplasty and reverse total shoulder arthroplasty) has transformed the clinical outcomes of shoulder disorders. Improvement of general clinical outcome is the result of stronger adequacy of the treatment to the diagnosis, enhanced surgical techniques, specific implanted materials, and more accurate follow up. Imaging is an important tool in each step of these processes., Method: This article is a review article declining recent imaging processes for shoulder arthroplasty., Results: Shoulder imaging is important for shoulder arthroplasty pre-operative planning but also for post-operative monitoring of the prosthesis and this article has a focus on the validity of plain radiographs for detecting radiolucent line and on new Computed Tomography scan method established to eliminate the prosthesis metallic artefacts that obscure the component fixation visualisation., Conclusion: Number of shoulder arthroplasties implanted have grown up rapidly for the past decade, leading to an increase in the number of complications. In parallel, new imaging system have been established to monitor these complications, especially component loosening.

Total shoulder arthroplasty (TSA) is an effective approach for the treatment of a variety of clinical conditions affecting the shoulder, including osteoarthritis, inflammatory arthritis and osteonecrosis, and the number of TSA implanted has grown exponentially over the past decade. This review gives an update of the major complications, mainly infections, instability and loosening, encountered after TSA, based on a corpus of recent publications and a dynamic approach: The review focuses on the causes of glenoid loosening, which account for 80% of the complication, and underlines the importance of glenoid positioning in the recovery of early shouder function and in the long term survival rate of TSA.

Background The risk of pharmacokinetic interaction is important in HIV-infected cancer patients receiving concomitantly highly active antiretroviral therapy (HAART) and anti-cancer systemic treatments. We aimed to evaluate the safety profile of raltegravir-based HAART in cancer patients receiving multi-kinase inhibitors (MKIs). Patients and Methods We conducted a retrospective medical record review of adult, HIV-infected cancer patients treated in our institutions from January 2010 to December 2015. Patients eligible for the present analysis were those receiving a raltegravir-based HAART at the time of the initiation of a MKI for the treatment of advanced solid tumors. Treatment-related toxicity, virological outcomes and pharmacokinetic profile of MKIs were examined. Results Twelve patients (7 males, median age 55 years) were identified. Seven had sarcoma/GIST, 3 had hepatocellular carcinoma, one had pancreatic neuroendocrine tumor, and one had NSCLC. Patients received the following MKIs: imatinib (n = 3), sorafenib (n = 3), pazopanib (n = 3), sunitinib (n = 2) and erlotinib (n = 1). The mean CD4+ count at baseline was 929 cells/mm 3 , and 860 cells/mm 3 after completion of MKI treatment. In all patients, HIV viral loads remained below the limit of detection (40 copies/ mm 3 ) during the whole MKI treatment. No virological failure occurred. No unexpected or serious adverse event related either to raltegravir-based HAART or to MKIs was observed. The trough plasma concentrations of MKIs were assessed in 8 patients, and were found normal in all but one case (not related to raltegravir-based HAART). Conclusions The present data represent the first documentation of the concomitant use of raltegravir-containing HAART and MKIs in HIV-infected adult patients with advanced non-AIDS defining malignancies, with a reassuring safety profile.

Background: On November 13th, 2015, terrorist bomb explosions and gunshots occurred in Paris, France, with 129 people immediately killed, and more than 300 being injured. This article describes the staff organization, surgical management, and patterns of injuries in casualties who were referred to the Teaching European Hospital Georges Pompidou., Methods: This study is a retrospective analysis of the pre-hospital response and the in-hospital response in our referral trauma center. Data for patient flow, resource use, patterns of injuries and outcomes were obtained by the review of electronic hospital records., Results: Forty-one patients were referred to our center, and 22 requiring surgery were hospitalized for>24h. From November 14th at 0:41 A.M. to November 15th at 1:10 A.M., 23 surgical interventions were performed on 22 casualties. Gunshot injuries and/or shrapnel wounds were found in 45%, fractures in 45%, head trauma in 4.5%, and abdominal injuries in 14%. Soft-tissue and musculoskeletal injuries predominated in 77% of cases, peripheral nerve injury was identified in 30%. The mortality rate was 0% at last follow up., Conclusion: Rapid staff and logistical response, immediate access to operating rooms, and multidisciplinary surgical care delivery led to excellent short-term outcomes, with no in-hospital death and only one patient being still hospitalized 45days after the initial event., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Purpose: To establish a new imaging technique using dynamic MRI three-dimensional (3D) volumetric acquisition in real-time, on six normal shoulders for the analysis of the 3D shoulder kinematics during continuous motion., Materials and Methods: At first, a standard static acquisition was performed. Then, fast images were obtained with a multi-slice 3D balanced gradient echo sequence to get a real time series during the initial phase of shoulder abduction. Subsequently, the images were reconstructed; registered and the translational patterns of the humeral head relative to the glenoid and the size of the subacromial space were calculated. Additionally, the intraobserver reproducibility was tested., Results: The maximal abduction was on average 43° (30° to 60°) and the mean width of the subacromial space was 7.7 mm (SD: ±1.2 mm). Difference between extreme values and average values was low, respectively 2.5 mm on X-axis, 2 mm on Y-axis, 1.4 mm for the width of the subacromial space and 1.2° for the measure of the glenohumeral abduction., Conclusion: This study reported a dynamic MRI protocol for the monitoring of shoulder 3D kinematics during continuous movement. The results suggest that there is no superior shift of the humeral head during the first phase of abduction., (Copyright © 2013 Wiley Periodicals, Inc.)

Background: The success of Total Shoulder Arthroplasty (TSA) is believed to depend on the restoration of the natural anatomy of the joint and a key development has been the introduction of modular humeral components to more accurately restore the patient's anatomy. However, there are no peer-reviewed studies that have reported the degree of glenoid component mal-position achieved in clinical practice and the clinical outcome of such mal-position. The main purpose of this study was to assess the accuracy of glenoid implant positioning during TSA and to relate it to the radiological (occurrence of radiolucent lines and osteolysis on CT) and clinical outcomes., Methods: 68 TSAs were assessed with a mean follow-up of 38+/-27 months. The clinical evaluation consisted of measuring the mobility as well as of the Constant Score. The radiological evaluation was performed on CT-scans in which metal artefacts had been eliminated. From the CT-scans radiolucent lines and osteolysis were assessed. The positions of the glenoid and humeral components were also measured from the CT scans., Results: Four position glenoid component parameters were calculated The posterior version (6°±12°; mean ± SD), the superior tilt (12°±17°), the rotation of the implant relative to the scapular plane (3°±14°) and the off-set distance of the centre of the glenoid implant from the scapular plane (6±4 mm). An inferiorly inclined implant was found to be associated with higher levels of radiolucent lines while retroversion and non-neutral rotation were associated with a reduced range of motion., Conclusion: this study demonstrates that glenoid implants of anatomic TSA are poorly positioned and that this malposition has a direct effect on the clinical and radiological outcome. Thus, further developments in glenoid implantation techniques are required to enable the surgeon to achieve a desired implant position and outcome.

Study Design: Spine Update on prognostic scoring systems for spinal metastases in the era of anti-vascular endothelial growth factor (VEGF) therapies., Objective: To review and discuss the strengths and weaknesses of available scoring systems since the introduction of molecular targeted anticancer agents., Summary of Background Data: Molecular targeted anticancer agents have dramatically improved survival of patients in various cancers, including renal cancer., Methods: Using prognostic scoring systems for spinal metastases and recent survival data of patients with cancers treated with anti-VEGF agents, a review was undertaken, evaluating the strengths and weaknesses of available prognostic scoring systems designed in the 1990s and early 2000s among patients treated with recent agents (available from 2005)., Results: All available prognostic scoring systems for spinal metastases include the primary tumor as a key variable. The estimation of life expectancy with these systems is inaccurate in view of recent survival data, as illustrated in renal cancer. The underestimation of life expectancy and subsequent inadequate treatment of spinal metastases may lead to dramatic alteration of the quality of life., Conclusion: The assessment of the available scores in recent cohorts of patients is mandatory to test their current validity and evidence the need for aggressive surgical management. New scoring systems taking into account the gain in survival induced by recent anticancer agents will likely be warranted in a close future.

Three- and four-part fractures of the proximal humerus are usually treated surgically. Open reduction with internal fixation (ORIF) is the method of choice in younger patients. Anatomic reduction of the tuberosities is crucial to ensure that, in the event of poorly tolerated avascular necrosis of the humeral head, hemiarthroplasty can be performed under optimal conditions. Suboptimal outcomes may occur after ORIF, as less-than-perfect reduction and fixation is poorly tolerated at the shoulder. Preoperative computed tomography must be performed routinely to analyse fragment displacement and comminution, classify the fracture, assess humeral head vitality, and evaluate the mechanical properties of the underlying bone. Fracture reduction relies on principles that are shared by the various available techniques. Reduction of each fragment should be assessed separately. Reduction of the humeral head to the shaft should be performed before reduction of the tuberosities. The fixation technique should ensure stability of the anatomic reduction, with secure fixation of the tuberosities and a minimal risk of material migration into the joint. Here, we provide a detailed discussion of the various techniques, with their advantages and drawbacks, to help surgeons select the method that is most appropriate to each individual patient., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

Background: Current techniques for measuring in vivo polyethylene wear suffer from a range of problems, resulting in an unacceptable lack of repeatability and/or insufficient accuracy when they are used to measure the low wear rates associated with new, highly crosslinked polyethylene. We describe an improved CT method for measurement of 3D femoral head penetration in PE acetabular cups that has sufficient accuracy and repeatability to allow assessment of the wear potential of modern implants., Method: The accuracy and repeatability of the CT-scan method was determined by blindly repeating measurements on a precisely calibrated 28-mm prosthetic head and by comparing them with direct metrological measurements on 10 acetabular specimens with in vitro wear from machining, and on 8 explanted acetabular specimens with in vivo wear., Results: The intra- and interobserver errors in femoral head diameter were 0.036 mm (SD 0.044) and 0.050 mm (SD 0.022), respectively. CT estimated femoral head penetration in both all-poly and metal-backed acetabular components with accuracy ranging from 0.009 to 0.245 mm (mean 0.080; SD 0.067)., Interpretation: We found that the CT method is rapid, is accurate, and has repeatability and ease of availability. Using a slice thickness of 0.0625 mm, this method can detect wear—and also the threshold for the wear rate that causes osteolysis—much earlier than previous methods.

Objective: To determine the comparative rate of resolution of a contusion resulting from mechanical trauma to skeletal muscle, as a function of one of four exercise regimens., Design: Randomized control trial. The four exercise regimens were: running with its onset immediately after injury, running with a 72 hr delay after injury, swimming with immediate onset, or swimming with a 72 hr delay. Control did not exercise., Setting: Small-animal laboratory., Participants: Male Sprague-Dawley rats., Intervention: A small animal traumatizing machine applied to the biceps femoris., Main Outcome Measures: The rate of contusion resolution was determined by a manual count of erythrocytes, leukocytes and collagen fibers in the contusion, and the data were analyzed using analysis of variance., Results: Exercise of any type produced a greater decline in erythrocyte count (28.2% after 32 days vs. control) than no exercise. Immediate onset of any of the exercise regimens after injury resulted in a greater decline in erythrocyte count (32.7% after 32 days vs. control) and in leukocyte count (17.3% after 32 days vs. control) than delayed onset. Running with either immediate or delayed onset of exercise after injury produced a greater decline in erythrocyte count (36.2% after 32 days vs. control) than swimming. Running with its onset immediately after injury produced the greatest overall rate of decrease in erythrocyte count (44.8% after 32 days vs. control), and the second greatest overall rate of decrease in leukocyte count (15.0% after 32 days vs. control)., Conclusions: Running with immediate onset is the regimen of choice. Any of the given exercises is preferable to no exercise, immediate onset of exercise is preferable to delayed onset, and running is preferable to swimming.

A case of the external derangement-type temporomandibular disorder (TMD), temporarily relieved following chiropractic sacro-occipital technique (SOT) treatment, including SOT category II blocking to reduce sacroiliac sprain, is presented. Symptom exacerbation midway through the course of treatment followed additional dental work; symptom remission followed additional SOT treatment. Freedom from symptoms is maintained with a 3-wk treatment interval. There appears to be a cause-effect relationship between external derangement-type TMD and sacroiliac sprain. Concurrent, coordinated chiropractic and dental treatments may improve the success rate of TMD resolution.

Demineralization of tooth mineral in the caries process was studied using a computer model that simulates a diffusion controlled dissolution process. The model consists of a two-compartment system. An acidic solution in the outer ("plaque") compartment was assumed to be large in volume so that its composition remained constant during the process. The solution in the inner ("lesion") compartment was in equilibrium with the tooth mineral, but its composition changed in response to diffusion of ions between the two solutions through an infinitely thin barrier. The permselectivity of the diffusion barrier to cations and anions can be modified as desired thus allowing the effects of membrane on the diffusion-dissolution process to be examined. Because the losses of calcium (Ca) and phosphate (P) from the "lesion" to the "plaque" generally does not occur at a molar ratio of 5/3, the Ca to P ratio of the dissolving mineral, the composition of the "lesion" fluid can change significantly from the starting composition, and this in turn modifies the Ca and P fluxes. A steady state condition is eventually reached under which the ratio of flux of Ca to that of P becomes 5/3. The results of the simulation show that for a given "plaque" pH, the rate of demineralization at steady state was the highest for cation and the lowest for anion permselective membranes. These results were in good agreement with those from an experimental study under comparable conditions.

The open-field behavior of of 30 laboratory albino rats was measured after selective unilateral sectioning of either the L2, L3, L4 or L5 spinal nerve root using a novel abdominal entry. Although treated subjects displayed observable motor dysfunction of the operated limb, no differences were found in open-field ambulation, rearing, defecation or urination based either on the level of the sectioned nerve root or on the day the behavior was measured, suggesting that there was an effect of the treatment not measurable by standard statistical procedures, quite possibly due to the small sample size.

A carbonate equilibration method was used to measure the buffer capacity of resting plaque fluid collected from single buccal or interproximal sites of upper and lower first molars or anterior teeth. The maximum buffer capacity was 26 m-equiv./l at pH 7.1. The buffer contribution from the measured concentrations of phosphate and carbonate was calculated for each sample. These values were compared with the buffering actually measured and with that expected from organic acids, proteins, and amino acids at average values, as taken from reports in the literature. Relative contributions of buffer species at the average pH of the samples (6.86) were: 35 per cent phosphate, 10 per cent carbonate, 10 per cent protein, 10 per cent organic acids, 2 per cent amino acids, 30 per cent unidentified. There were no significant differences in the buffer capacities of samples originating from sites that differ in their accessibility to saliva. Buffering in resting plaque fluid is more than twice that in saliva and did not show differences correlated with the intra-oral location of the samples.

Solubility of CaHPO 4 · 2H 2 O was determined in the quaternary system Ca(OH) 2 - H 3 PO 4 - NaCl - H 2 O at 25 °C in the pH range 4.39-6.38; ionic strengths of the saturated solutions varied from 0.00485 to 0.545, Satisfactory constancy in the solubility product, ( K sp = [ Ca 2 + ] ⋅ [ HPO 4 2 - ] ⋅ γ Ca 2 + ⋅ γ HPO 4 2 - = 2.49 ± 0.05 × 10 - 7   mol 2 × 1 - 2 ) was obtained when (i) the ion activity coefficients, γ i , were calculated with the Debye-Hückel equation, log   γ i = - A Z i 2 I / ( 1 + B α i I ) + 0.0626   I ; the value 0.0626 for the coefficient in the linear term was derived from the solubility data by utilizing a statistical procedure, and (ii) formation of an ion pair NaHPO 4 - was taken into account; a statistically derived value for the stability constant of this ion pair is 7.0 ± 2.4 1 × mol -1 . The ion pair NaHPO 4 - appears to have significant concentrations in physiological fluids.

In this study, the physicochemical factors responsible for caries-like lesion propagation were investigated by means of a micro-analytical system used to study the fluid within a lesion during a simulation of the decay process. Four 500-microns-thick serial sections prepared from a single human molar were mounted between glass plates with only the natural surface of the tooth exposed. Microwells were then drilled into sound and pre-existing carious regions of the section through one of the plates. These microwells were then filled with fluid under mineral oil, and after a week of equilibration, the natural surface of the section was exposed to a lesion-producing fluid. The concentrations of calcium, phosphate, and hydrogen ions of the fluid in the wells were then followed as a function of time as the lesion advanced. The results of this study, in which lactic acid was used to demineralize enamel, were consistent with those previously reported (Vogel et al., 1987a): The solution within the lesion remained saturated during the acid attack. Differences in initial mobilities of the calcium and phosphate and other ions, a result of the permselectivity of the enamel, increased the concentrations within the lesion and permanently changed the ratio of these ions in the lesion solution. Based on these results, we suggest that the ionic permselectivity of tooth enamel can have a profound effect on the transport of mineral from a caries lesion.

Solubility isotherms of beta-tricalcium phosphate, β -Ca(PO 4 ) 2 , prepared by heating mixtures of CaCO 3 and CaHPO 4 above 800 °C, were determined in the ternary system Ca(OH) 2 -H 3 PO 4 -H 2 O at 5, 15, 25, and 37 °C in the pH range 6.0-7.5 by equilibration with dilute H 3 PO 4 solutions. The results indicate that β -Ca 3 (PO 4 ) 2 has a negative thermal coefficient of solubility. The solubility product, K s , was determined as a function of temperature by a generalized least-squares procedure; the resulting equation is log K s = - 45723.26 / T + 287.4536 - 0.546763 T ; the values of K s and its dispersion at 25 and 37 °C are 1.20(0.056), and 0.283(0.011) × 10 -29 . Thermodynamic functions for the dissolution of the salt at the four experimental temperatures are reported. When treated as an adjustable constant, the Ca/P ratio in these β -Ca 3 (PO 4 ) 2 solutions was found to have the value 1.514(0.010), confirming that the stoichiometry of the high temperature form of this salt is correctly indicated by the above formula. The computed isotherms at 25 °C for several calcium phosphates are compared; it is shown that β -Ca 3 (PO 4 ) 2 is, next to Ca 5 (PO 4 ) 3 OH, the most stable at pH's above 6.36. The singular points of the β -Ca 3 (PO 4 ) 2 isotherm with those of CaHPO 4 · 2H 2 O and CaHPO 4 are at pH's 5.88 and 6.36, respectively.

Using a generalized least square procedure, a method is developed to estimate diffusion coefficients, D ij , from concentration measurements made in a set of experiments of varying duration but with the same initial conditions. The method requires neither approximations nor restrictions in the flow equations. The D ij and their errors are calculated simultaneously with the adjustment of the weighted observables - concentrations of the two solute components and time. A procedure is described to insure convergence in a given experimental set. The effect of the duration of the longest experiment, and errors in the observables on the estimated values of D ij and their errors, are investigated. Application of the method to available data yielded values for D ij in agreement with those previously calculated by more involved procedures.

Two portions of a synthetic hydroxyapatite (HA), Ca 5 OH(PO 4 ) 3 , fully characterized by x-ray, infrared, petrographic, and chemical analyses, were heated at 1,000 °C in air and steam atmospheres, respectively. Solubility isotherms for these two samples in the system Ca(OH) 2 -H 3 PO 4 -H 2 O were determined in the p H range 5 to 7 by equilibrating the solids with dilute H 3 PO 4 solutions. Both samples of HA dissolved stoichiometrically. The activity products ( Ca + + ) 5 ( OH - ) ( PO 4 ≡ ) 3 and their standard errors-obtained by a least squares adjustment of the measurements (Ca and P concentrations and p H of the saturated solutions) subject to the conditions of electroneutrality, constancy of the activity product, and stoichiometric dissolution - were 3.7 3 ± 0.5 × 10 -58 for the steam-heated HA and 2.5 1 ± 0.4 × 10 -55 for the air-heated HA. Allowance was made in the calculations for the presence of the ion pairs [CaHPO 4 ] 0 and [CaH 2 PO 4 ] + . The higher solubility product for the air-heated HA is ascribed either to a change in the heat of formation brought about by partial dehydration or to a state of fine subdivision resulting from a disproportionation reaction. The solubility product constants were used to calculate the points of intersection (i.e., singular points) of the two HA solubility isotherms with the isotherms of CaHPO 4 · 2H 2 O and CaHPO 4 ; it was found that the p H's of the singular points for the air-heated HA were a full unit higher than those of the steam-heated preparation. Conditions are described for the precipitation of HA crystals suitable for solubility measurements.

The solubility isotherm for CaHPO 4 · 2H 2 O (DCPD) in the three-component system Ca(OH) 2 - H 3 PO 4 - H 2 O was determined in the p H range 3.5 to 6.8 by leaching a thermostated column of DCPD with dilute phosphoric acid solutions. In confirmatory experiments, equilibrium was approached both from super- and under-saturation by shaking DCPD with appropriate solutions. The calculated ionic activity product (Ca ++ ) × ( HPO 4 = ), appeared to be a parabolic function of p H with a minimum near p H 5.0. The p H dependence of the ionic product could be accounted for by considering the ion pairs [CaHPO 4 ]° and [CaH 2 PO 4 ] + as semi-empirical parameters. Under the condition of saturation with respect to DCPD, the activity of the pair [CaHPO 4 ]° must be a constant. The activity of the species [CaH 2 PO 4 ] + was shown to vary directly with hydrogen ion activity. The activities of the two ion pairs were adjusted to give a set of p H-independent ionic activity products with a mean of 2.19±0.011 × 10 -7 . The stability constants for [CaHPO 4 ]° and [CaH 2 PO 4 ] + are 5.88±0.031 × 10 2 and 7.49 ±0.039, respectively. Experiments were conducted to study the hydrolysis of DCPD to more basic calcium phosphates and the kinetics of these transformations is discussed. The significance of the ion pairs in human serum is considered.

Solubility isotherms for CaHPO 4 · 2H 2 O, dicalcium phosphate dihydrate, DCPD, in the ternary system Ca(OH) 2 - H 3 PO 4 - H 2 O were determined at 5, 15, 25, and 37.5 °C in the pH range 3.5 - 7; the relative positions of the isotherms indicate that DCPD has a negative thermal coefficient of solubility. The solubility product, K s , of DCPD and the stability constants K x and K y for the ion pairs [ CaHPO 4 0 ] and [ CaH 2 PO 4 + ] , respectively, were obtained as functions of temperature by the use of a generalized least squares procedure subject to three condition functions - constancy of the solubility product, electrical neutrality in the solution, and congruent dissolution of the solid. The equations obtained are ln  K s = - 8403 .5 / T + 41 . 863 - 0 . 09678 T ​ln  K x = - 51090 / T - 341.14 + 0 . 5880 T ​ln  K y = - 19373 / T - 122.81 + 0 . 1994 T The existence of a maximum in K s in the neighborhood of 25 °C is plausible on the basis of available thermodynamic data for DCPD. Thermodynamic functions are reported for the solution of DCPD and for the association of the ion pairs.