Ultrasound assessment of the infrapatellar fat pad can detect Hoffa-synovitis in patients following anterior cruciate ligament reconstruction: A pilot study.

Introduction: Osteoarthritis (OA) commonly occurs following anterior cruciate ligament reconstruction (ACLR), affecting over 50 % of patients within 10-15 years post-ACLR. The Hoffa-synovitis of the infrapatellar fat pad (IPFP) has been implicated as a major contributor to OA pathogenesis. While MRI is typically used to evaluate the IPFP, it is cost-prohibitive for routine screening. This study aimed to validate ultrasound as an alternative for detecting IPFP Hoffa-synovitis in participants post-ACLR. Methods: In this cross-sectional study, 15 participants (18-35 years, 1-5 years post-ACLR) underwent two imaging sessions separated by one week. First, a standardized bilateral anterior knee ultrasound assessment was used to examine IPFP echo-intensity. Second, MRI scans of both knees were graded by a board-certified musculoskeletal radiologist for Hoffa-synovitis according to the Anterior Cruciate Ligament Osteoarthritis Score grading system. IPFP echo-intensity were quantified on each ultrasound image, and a limb symmetry index (LSI) was calculated to assess between-limb differences. We used an independent t-test and Cohen's d effect sizes to compare IPFP echo-intensity LSI between people with and without MRI-confirmed Hoffa-synovitis. Results: Four of the 15 participants (27 %) exhibited MRI-confirmed Hoffa-synovitis. Significantly higher IPFP echo-intensity LSI values were found in participants with Hoffa-synovitis (32.1 ± 12.1 %) compared to those without (10.5 ± 10.4 %), confirming the ultrasound's ability to distinguish between the two groups (t = -3.44; p = 0.004; d = 2.01). Discussion: Ultrasound detects bilateral IPFP signal intensity alterations in participants post-ACLR with MRI-confirmed Hoffa-synovitis. This work should be seen as a proof-of-concept, and further validation in a larger, more diverse sample is essential for verifying these results.

Neumatocele traumático: una presentación inusual del trauma cerrado de tórax en paciente de 21 años / Traumatic pneumatocele: an unusual presentation of blunt chest trauma in a 21-year-old patient

El neumatocele traumático, o pseudoquiste pulmonar traumático, es una complicación infrecuente del trauma cerrado de tórax, caracterizada por lesiones cavitadas únicas o múltiples de paredes fibrosas bien delimitadas, sin revestimiento epitelial. Representa un reto diagnóstico ante la prevalencia de etiologías más frecuentes de cavitación pulmonar, presentación clínica inespecífica y el carácter subreportado de la patología. Se presenta el caso de un paciente de 21 años, con cuadro clínico de fiebre y dolor torácico posterior a traumatismo contuso por accidente en motocicleta, con identificación de una lesión cavitada rodeada de vidrio esmerilado, ubicada en lóbulo superior derecho en tomografía de tórax. Se ofreció tratamiento antibiótico ante la sospecha clínica de sobreinfección. Sin embargo, se atribuyó la alteración pseudoquística pulmonar al antecedente traumático. En ocasiones las cavitaciones pulmonares postrauma no son identificadas en la atención inicial, por ende, es fundamental la evaluación clínica e imagenológica subsecuente.

Traumatic pneumatocele, or traumatic pulmonary pseudocyst, is a rare complication of blunt chest trauma, characterized by multiple or unique cavitary lesions, with well-defined fibrous walls without epithelial lining. It represents a diagnostic challenge due to the higher prevalence of other etiologies of lung cavities, nonspecific clinical features and the under-reported nature of this pathology. We present the case of a 21-year-old male with fever and chest pain after a blunt chest trauma in a motorcycle accident, with identification of a cavity in the right upper lobe, surrounded by ground glass opacities. Antibiotic therapy was administered after clinical suspicion of superinfection, however, the cavitary lesion was attributed to the trauma. Occasionally, traumatic pulmonary pseudocysts are not identified during initial assessment, therefore, clinical and imagenologic follow-up is essential.

In transit metastases in children, adolescents and young adults with localized rhabdomyosarcoma of the distal extremities: Analysis of the EpSSG RMS 2005 study.

In-transit metastases (ITM) are defined as metastatic lymph nodes or deposits occurring between the primary tumor and proximal draining lymph node basin. In extremity rhabdomyosarcoma (RMS), they have rarely been reported. This study evaluates the frequency, staging and survival of patients with ITM in distal extremity RMS. METHODS: Patients with extremity RMS distal to the elbow or knee, enrolled in the EpSSG RMS 2005 trial between 2005 and 2016 were eligible for this study. RESULTS: One hundred and nine distal extremity RMS patients, with a median age of 6.2 years (range 0-21 years) were included. Thirty seven of 109 (34%) had lymph node metastases at diagnosis, 19 of them (51%) had ITM, especially in lower extremity RMS. 18F-FDG-PET/CT detected involved lymph nodes in 47% of patients. In patients not undergoing 18F-FDG-PET/CT lymph node involvement was detected in 22%. The 5-yr EFS of patients with ITM vs proximal lymph nodes vs combined proximal and ITM was 88.9% vs 21.4% vs 20%, respectively (p = 0.01) and 5-yr OS was 100% vs 25.2% vs 15%, respectively (p = 0.003). CONCLUSION: Our study showed that in-transit metastases constituted more than 50% of all lymph node metastases in distal extremity RMS. 18F-FDG-PET/CT improved nodal staging by detecting more regional and in-transit metastases. Popliteal and epitrochlear nodes should be considered as true (distal) regional nodes, instead of in-transit metastases. Biopsy of these nodes is recommended especially in distal extremity RMS of the lower limb. Patients with proximal (axillary or inguinal) lymph node involvement have a worse prognosis.

Nitrogen retention in hair sheep lambs with a gradient of Haemonchus contortus infection.

The impact of Haemonchus contortus infections on nitrogen retention (NR) of hair sheep lambs is unknown. This study estimated the feed intake, digestibility, NR, haematocrit (HT), and their relationship with the gradient of H. contortus infection in hair sheep lambs. Twenty-four hair sheep lambs, 3-4 months old, reared parasite-free were used (live weight (LW) 16.7 ± 1.7 kg). Six lambs were kept parasite-free, nine lambs received a dose of 300 H. contortus infective larvae (L3)/kg LW, and the remaining nine lambs received 500 H. contortus L3/kg LW. Infection doses ranged from 3870 to 9,500 L3. Lambs were individually fed for an average daily gain (ADG) of 100 g. On days 1 (P < 0.01) and 7 (P < 0.001) post-infection (PI), the L3 doses were positively associated with HT, possibly due to platelet recruitment. On week 1 PI, the infection (L3) reduced the crude protein (CP) intake (g/kg metabolic LW) (P < 0.05). A reduction of 1% HT corresponded to 1200 eggs per gram of faeces (EPG) for day 21 PI (P < 0.05), 2300 EPG for day 28 PI (P < 0.001), 2400 EPG for day 35 (P < 0.001), and 1300 EPG for day 41 PI (P < 0.001). However, the HT levels were never lower than 21 %. A lower CP digestibility was associated with EPG only on week 5 PI (P < 0.05). There was no significant association between EPG, Total egg in faeces, or worm burden (WB) with intake, dry matter digestibility (DMD), ADG or NR. The NR of lambs was positive along the different weeks of study irrespective of infection level. The WB was negatively associated only with HT on day 41 PI (P < 0.001), where a 1 % HT reduction was estimated for every 257 worms hosted. In conclusion, no relationship was found between H. contortus infection and DMD, ADG or NR in hair sheep lambs. The cost of H. contortus infection resulted only from the HT reduction and depended on the gradient and stage of the infection.

Epidemiology of tumors in dogs in the capital of the state of Mexico from 2002-2016 / Epidemiologia de tumores em cães da capital do Estado do México durante o período de 2002-2016

A retrospective and cross-sectional study of canine tumors was performed in the capital of State of Mexico from 2002-2016. Since then, 393 tumors were remitted. Descriptive epidemiology was made from all data: breed, age, sex, and tumor features. Then the risk association between cutaneous and non-cutaneous tumors with variables such as sex, breed, and age were analyzed through an exact Fisher test and Odds ratio. In addition, some characteristics of the canine population were studied under a survey. Of all tumors, skin tumors were the most frequent (59.0%). The group of tumors related to ultraviolet radiation was the most common (15.1%). The frequency of tumors in females was 53%, nevertheless, males had more risk to develop cutaneous tumors (OR=1.88, 1.24-2.84) (0.003). The Pure breeds were the most common (82.5%) and the most frequent age range was > 7 years (54.7%). The survey showed that males (53%) and the age range 1-7 years (62.1%) were the most frequent. Conclusions, age, breed, and sex were identified as the major risk factors for tumorigenesis. Likewise, skin tumors were associated with exposure to ultraviolet radiation, probably to the height of the locality (2667mamls).(AU)

Um estudo retrospectivo e transversal dos tumores caninos foi realizado na capital do Estado do México durante o período de 2002-2016. Desde esse período, 393 tumores foram remetidos. Epidemiologia descritiva foi feita com base em todos os dados: raça, idade, sexo e características do tumor. Em seguida, a associação de risco entre tumores cutâneos e não cutâneos com variáveis como sexo, raça e idade foi analisada por meio do teste exato de Fisher e odds ratio. Além disso, algumas características da população canina foram estudadas em uma pesquisa. De todos os tumores, os de pele foram os mais frequentes (59,0%). O grupo de tumores relacionados à radiação ultravioleta foi o mais comum (15,1%). A frequência de tumores no sexo feminino foi de 53%, no entanto os machos apresentaram maior risco de desenvolver tumores cutâneos (OR = 1,88; 1,24-2,84) (0,003). As raças puras foram as mais comuns (82,5%), e a faixa etária mais frequente foi >7 anos (54,7%). A pesquisa mostrou que os machos (53%) e a faixa etária de um a sete anos (62,1%) foram os mais frequentes. Conclusões: idade, raça e sexo foram identificados como os principais fatores de risco para a tumorigênese. Da mesma forma, os tumores cutâneos foram associados à exposição à radiação ultravioleta, provavelmente até a altura da localidade (2667m ANM).(AU)

Criollo goats limit their grass intake in the early morning suggesting a prophylactic self-medication behaviour in a heterogeneous vegetation.

The present study compared the feeding behaviour of goats in the early morning (EM = 7:00-8:30 a.m.) and late morning (LM = 9:30-11:00 a.m.) in response to their natural gastrointestinal nematode (GIN) infection status. Twelve female adult goats (37 ± 7.7 kg live weight (LW); 5 ± 1 years) with browsing experience in the tropical deciduous forest were divided into two groups (n = 6): INF group, with natural GIN infection, and non-infected (NI) group, dewormed with moxidectin (0.4 mg/kg LW subcutaneous). Feeding behaviour (dry matter intake (DMI)) of two resource types (grasses vs. shrubs + herbs) was estimated by direct observation for 4 weeks on two grazing moments (EM vs. LM). Environmental temperature and relative humidity at pasture level were measured twice weekly. The GIN egg counts and goats' LW were measured on days 0, 14 and 28. Temperature (mean ± standard deviation) at EM (26.2 ± 1.5 °C) was lower than at LM (38.7 ± 1 °C; P < 0.01). Humidity was higher on the EM (85.1 ± 2.6%) compared to LM (60.4 ± 5.6%; P < 0.01). Irrespective of the infection status, goats consumed similar amounts of grass and shrubs + herbs during EM (P > 0.05). On the other hand, the experimental groups consumed more grass than shrubs + herbs during LM (P < 0.05). The latter suggested prophylactic behaviours strategies to (a) avoid GIN infective larvae, (b) balance the protein:energy ratio of the diet and (c) avoid saturation of detoxification pathways for the secondary compounds consumed from shrubs + herbs. The constant consumption of shrubs + herbs during the study may have reduced the GIN egg count of the INF group.

First identification and characterization of Streptococcus iniae obtained from tilapia (Oreochromis aureus) farmed in Mexico.

This is the first study to isolate, identify and characterize Streptococcus iniae as the causative disease agent in two tilapia (Oreochromis aureus) populations. The populations were geographically isolated, of distinct origins, and did not share water sources. Affected fish showed various external (e.g., exophthalmia and cachexia, among others) and internal (e.g., granulomatous septicaemia and interstitial nephritis, among others) signs. All internal organ samples produced pure cultures, two of which (one from each farm, termed S-1 and S-2) were subjected to biochemical, PCR and 16S rRNA sequencing (99.5% similarity) analyses, confirming S. iniae identification. The two isolates presented genetic homogeneity regardless of technique (i.e., RAPD, REP-PCR and ERIC-PCR analyses). Pathogenic potentials were assessed through intraperitoneal injection challenges in rainbow trout (Oncorhynchus mykiss) and zebrafish (Danio rerio). Rainbow trout mortalities were respectively 40% and 70% at 104 and 106  CFU per fish with the S-1 isolate, while 100% mortality rates were recorded in zebrafish at 102 and 104  CFU per fish with the S-2 isolate. The obtained data clearly indicate a relationship between intensified aquaculture activities in Mexico and new disease appearances. Future studies should establish clinical significances for the tilapia industry.

Socioeconomic status as an independent risk factor for severe late bowel toxicity after primary radiotherapy for cervical cancer.

OBJECTIVE: To evaluate the frequency of and risk factors for severe late bowel toxicity after curative radiotherapy in women treated for locally advanced cervical cancer. METHODS: Included were 515 women treated for locally advanced cervical cancer with primary radiotherapy with curative intent from 1992 to 2013. Bowel toxicity was graded according to the Common Terminology Criteria for Adverse Events. Associations between risk factors and severe late bowel toxicity were assessed using Cox proportional hazards regression models. RESULTS: Median follow-up was 78months. Fifty-nine patients developed severe late bowel toxicity. The actuarial 3-year and 5-year severe late bowel toxicity rates were both 13%. In the multivariable analysis, factors significantly associated with severe late bowel toxicity were: smoking (HR 2.59 [1.48-4.55]), severe acute bowel toxicity (HR 2.46 [1.24-4.49]), previous major abdominal surgery (HR 2.35 [1.20-4.60]), hypertension (HR 2.33 [1.23-4.40]), parametrial boost (HR 2.18 [1.10-4.33]), low socioeconomic status (HR 2.05 [1.17-3.59]) and low BMI (HR 0.93 [0.88-0.99]). First symptoms of severe late bowel toxicity were reported after a median follow-up of 9months, but occurred up to 10years after end of treatment. Only one third of the patients with severe late bowel toxicity were referred to a gastroenterologist. CONCLUSIONS: Severe late bowel toxicity is a frequent complication of definitive radiotherapy for cervical cancer. Several independent risk factors were found which warrant further research. A standardized and structured approach in the early diagnostics and management of bowel toxicity is needed.

Postoperative single-dose interstitial high-dose-rate brachytherapy in therapy-resistant keloids.

PURPOSE: Patients with keloids complain of the cosmetic aspect, pain, and pruritus. Many different therapies are being used for keloids. The aim of this study was to evaluate the recurrence rate and outcome after resection followed by a single-dose brachytherapy. METHODS AND MATERIALS: Patients treated by resection of the keloid plus a single dose of 13 Gy high-dose-rate brachytherapy were evaluated at least 1 year after treatment. Clinical response and cosmesis were assessed by a plastic surgeon and by the patients using the Patient and Observer Scar Assessment Scale. RESULTS: Only 24 of the 61 invited patients responded to participate with the study; 29 keloids were evaluated. The recurrence rate was 24.1% after a median followup of 53 months (19-95 months). Patients scored on average 24.3 for their total Patient and Observer Scar Assessment Scale score (range 6-52), whereas the observer scored on average 14.6 (range 6-42). CONCLUSIONS: This treatment has a higher recurrence rate than that reported in most other studies. This may be explained by differences in recurrence definition, differences in followup time among studies, and selection bias because of not contributing to the study. The cosmetic outcome for evaluated patients is relatively good. This treatment policy has the advantage that patients are treated in a single day.

A study of acute and chronic tissue changes in surgical and traumatically-induced experimental models of knee joint injury using magnetic resonance imaging and micro-computed tomography.

OBJECTIVE: The objective of this study was to monitor the progression of joint damage in two animal models of knee joint trauma using two non-invasive, clinically available imaging modalities. METHODS: A 3-T clinical magnet and micro-computed tomography (µCT) was used to document changes immediately following injury (acute) and post-injury (chronic) at time points of 4, 8, or 12 weeks. Joint damage was recorded at dissection and compared to the chronic magnetic resonance imaging (MRI) record. Fifteen Flemish Giant rabbits were subjected to a single tibiofemoral compressive impact (ACLF), and 18 underwent a combination of anterior cruciate ligament (ACL) and meniscal transection (mACLT). RESULTS: All ACLF animals experienced ACL rupture, and 13 also experienced acute meniscal damage. All ACLF and mACLT animals showed meniscal and articular cartilage damages at dissection. Meniscal damage was documented as early as 4 weeks and worsened in 87% of the ACLF animals and 71% of the mACLT animals. Acute cartilage damage also developed further and increased in occurrence with time in both models. A progressive decrease in bone quantity and quality was documented in both models. The MRI data closely aligned with dissection notes suggesting this clinical tool may be a non-invasive method for documenting joint damage in lapine models of knee joint trauma. CONCLUSIONS: The study investigates the acute to chronic progression of meniscal and cartilage damage at various time points, and chronic changes to the underlying bone in two models of posttraumatic osteoarthritis (PTOA), and highlights the dependency of the model on the location, type, and progression of damage over time.

Endocrine disorders among long-term survivors of childhood head and neck rhabdomyosarcoma.

PURPOSE: Head and neck rhabdomyosarcoma (HNRMS) survivors are at increased risk of developing pituitary dysfunction as an adverse event of radiotherapy. Our aim was to investigate the frequency and risk factors for pituitary dysfunction in these survivors. Secondly, we aimed to compare the prevalence of pituitary dysfunction between survivors treated with external beam radiation therapy (EBRT) and survivors treated with the ablative surgery, moulage technique after loading brachytherapy, and surgical reconstruction (AMORE) procedure. METHODS: Eighty HNRMS survivors treated in London (EBRT based) and Amsterdam (AMORE based: AMORE if feasible, otherwise EBRT) in the period 1990-2010 and alive ≥ 2 years post-treatment were evaluated. Survivors were evaluated in multidisciplinary late-effects clinics, with measurement of linear growth, determination of thyroid function, and growth hormone parameters. Additional data, such as baseline characteristics, anthropometrics, pubertal stage, and the results of additional laboratory investigations, were retrieved from patient charts. RESULTS: Pituitary dysfunction was diagnosed in 24 in 80 (30%) survivors, after a median follow-up time of 11 years. Median time to develop pituitary dysfunction after HNRMS diagnosis was 3.0 years. Risk factors were EBRT-based therapy (odds ratio [OR] 2.06; 95% confidence interval [CI] 1.79-2.46), parameningeal tumour site (OR 1.83; 95% CI 1.60-2.17) and embryonal RMS histology (OR 1.49; 95% CI 1.19-1.90). CONCLUSIONS: Radiotherapy used for the treatment of HNRMS confers a significant risk of the development of pituitary dysfunction. AMORE-based treatment in children with HNRMS resulted in less pituitary dysfunction than treatment with conventional EBRT. Our findings underscore the importance of routine early endocrine follow-up in this specific population.

Hearing loss in survivors of childhood head and neck rhabdomyosarcoma: a long-term follow-up study.

OBJECTIVES: To determine the hearing status of survivors treated for head and neck rhabdomyosarcoma (HNRMS) at long-term follow-up. DESIGN: Cross-sectional long-term follow-up study. SETTING: Tertiary comprehensive cancer centre. PARTICIPANTS: Survivors treated for HNRMS during childhood in two concurrent cohorts; survivors in London had been treated with external beam radiotherapy (EBRT-based local therapy); survivors in Amsterdam were treated with AMORE (Ablative surgery, MOuld technique afterloading brachytherapy and surgical REconstruction) if feasible, otherwise EBRT (AMORE-based local therapy). MAIN OUTCOME MEASURES: We assessed hearing status of HNRMS survivors at long-term follow-up. Hearing thresholds were obtained by pure-tone audiometry. METHODS: We assessed the hearing thresholds, the number of patients with clinically relevant hearing loss and hearing impairment graded according to the Common Terminology Criteria for Adverse Events version 4.0 (CTCAEv4) and Boston criteria. Furthermore, we compared hearing loss between survivors treated with EBRT-based local therapy (London) and AMORE-based local therapy (Amsterdam). RESULTS: Seventy-three survivors were included (median follow-up 11 years). We found clinically relevant hearing loss at speech frequencies in 19% of survivors. Multivariable analysis showed that survivors treated with EBRT-based treatment and those with parameningeal tumours had significantly more hearing impairment, compared to survivors treated with AMORE-based treatment and non-parameningeal tumours. CONCLUSIONS: One in five survivors of HNRMS developed clinically relevant hearing loss. AMORE-based treatment resulted in less hearing loss compared to EBRT-based treatment. As hearing loss was highly prevalent and also occurred in survivors with orbital primaries, we recommend systematic audiological follow-up in all HNRMS survivors.

Estimating mineral changes in enamel formation by ashing/BSE and microCT.

Enamel formation produces the most highly mineralized tissue in the human body. The growth of enamel crystallites is assisted by enamel proteins and proteinases. As enamel formation progresses from secretory to maturation stages, the composition of the matrix with its mineral and non-mineral components dynamically changes in an inverse fashion. We hypothesized that appropriately calibrated micro-computed tomography (µCT) technology is suitable to estimate the mineral content (weight and/or density) and volume comparable in accuracy with that for directly weighed and sectioned enamel. Different sets of mouse mandibular incisors of C57BL/6 mice were used for dissections and µCT reconstructions. Calibration phantoms corresponding to the range of enamel mineral densities were used. Secretory-stage enamel contained little mineral and was consequently too poor in contrast for enamel volumes to be accurately estimated by µCT. Maturation-stage enamel, however, showed remarkable correspondence for total mineral content per volume where comparisons were possible between and among the different analytical techniques used. The main advantages of the µCT approach are that it is non-destructive, time-efficient, and can monitor changes in mineral content of the most mature enamel, which is too physically hard to dissect away from the tooth.

Type 2 diabetes is associated with vertebral fractures in a sample of clinic- and hospital-based Latinos.

Latinos are the fastest growing ethnic population in the United States and type 2 diabetes is a major health burden in this population, but little effort has been made to study the prevalence of diabetic vertebral fragility in Latinos. We performed a cross-sectional study to determine vertebral fracture prevalence in a hospital-based population of South Texas residents (N = 296). We defined fractures in X-rays as a >20% reduction in vertebral body height. Numerous variables were recorded, including age, body mass index, indicators of diabetes management and others. 71% of the sample (N = 296) was Latino. The prevalence of vertebral fracture was increased in diabetic subjects relative to non-diabetic subjects (diabetic 27.9%, non-diabetic 13.8%) and, regardless of sex and diabetics status, decreased in Latinos relative to non-Latinos (Latino 16.7%, non-Latino 26.4%). These data suggest that vertebral fractures may be a growing concern for diabetic Latinos as well as diabetics of any racial/ethnic background.

The T963C mutation of TP53 gene does not participate in the clonal origin of canine TVT.

In dogs, the canine transmissible venereal tumor (CTVT) is the only neoplasm which is not produced by neoplastic transformation of normal cells; the tumor is transmitted from the affected dog to healthy dogs by implantation of one or various clones of cancer cells. Thus, the CTVT of dogs analyzed in various countries reveals similar genetic characteristics and consequently CTVT is considered to have a clonal origin. The CTVTs obtained from dogs in Korea showed the T963C mutation on TP53 gene; this mutation was thought to be a molecular alteration which participates in the origin of the ancestral clone, CTVT. Nonetheless, this supposed mutation has not been identified in other studies which were carried out for the purpose of clarifying the clonal origin of CTVT. Thus we have considered it important to identify the role of the T963C mutation of the TP53 gene in the clonal origin of CTVT in dogs. Consequently the region which includes the mutation of the TP53 gene in twenty samples of CTVT obtained from various canine breeds was PCR amplified and afterwards its sequence of nucleotides was determined. We conclude that this mutation did not participate in the clonal origin of the tumor, but was acquired at a later stage.

Identification of a genetic variant of canine distemper virus from clinical cases in two vaccinated dogs in Mexico.

Canine distemper virus (CDV) is a highly contagious viral pathogen of worldwide distribution that can cause lethal disease in dogs and other mammals. Genetic diversity is found among reference strains and isolates of CDV, mainly in the haemagglutinin protein (H), fusion protein (F) and nucleoprotein (N), and this may be associated with the increasing incidence of distemper in dogs. CDV was identified by RT-PCR in serum samples taken from two clinically diseased, previously vaccinated Mexican dogs. Subsequently, in both samples, a fragment of the CDV N gene was sequenced revealing a 100% identity between nucleotide sequences. However, the sequence obtained was different to that found in virus strains used in vaccines and in isolates reported elsewhere, but was closely related to A75/17, 1127/Gi95, and 2495/Gi95 sequences from USA and Germany, and clustered with 1127/Gi95 and 2495/Gi95 strains. The results suggest that a novel CDV lineage may be present in Mexico.

Role of cell-matrix interactions in osteoclast differentiation.

Osteoclast and their mononuclear cell precursors are present within the bone microenvironment at sites of physiologic and pathologic bone resorption. Analysis of tissues from sites of bone resorption reveal that cells expressing the full morphological and functional properties of mature osteoclasts are restricted to the immediate bone surface. We hypothesize that in addition to cytokines, components of the bone matrix and specific cell surface receptors on osteoclasts and their precursors play an essential role in determining the genetic profile and functional properties of fully differentiated resorbing osteoclasts. We have employed expression profiling, with an in vitro model of matrix-dependent osteoclast differentiation, to identify the molecular pathways by which bone matrix-interactions induce terminal osteoclast differentiation and activation. In preliminary studies, we have identified unique genes and transcriptional pathways that are induced by interaction of osteoclast precursors with specific components of the mineralized bone matrix. The authenticity of the gene profiles, as markers of osteoclast differentiation and activation, have been provisionally validated using an in vivo animal bone implantation model and by examination of tissues from patients with specific forms of pathologic osteoclast-mediated bone resorption. The ultimate goal of our studies is to identify new molecular targets for inhibiting osteoclast-mediated bone loss in disorders of pathologic bone loss. The early work of Walker et al. (Walker 1972) in parabiotic animals, and the subsequent studies of Burger et al. (Burger, Van der Meer, van de Gevel, et al. 1982) using a co-culture model with fetal bone rudiments and bone marrow-derived cells, have helped to establish that osteoclasts are derived from macrophage precursors of colony forming unit-macrophage (CFU-M lineage). As such, they share a common hematopoietic origin with other CFU-M lineage cells, including tissue macrophages that populate the lung (alveolar macrophages), liver (Kupfer cells), synovium (synovial macrophages) and other organs. They also share a common lineage

Postcranial skeletal pneumaticity: a case study in the use of quantitative microCT to assess vertebral structure in birds.

Limb elements in birds have been characterized as exhibiting a reduction in trabecular bone, thinner cortices and decreased bending strength when pneumatized, yet it is unclear if these characteristics generalize to the axial skeleton. Thin section techniques, the traditional gold standard for bone structure studies, have most commonly been applied to the study of avian bone. This destructive technique, however, makes it subsequently impossible to use the same samples in experimental testing systems that allow researchers to correlate structure with the mechanical properties of the bone. Micro-computed tomography (microCT), a non-destructive X-ray imaging technique, can be used to assess the effect of pneumatization on vertebral cortical and trabecular bone through virtual extraction and structural quantification of each tissue type. We conducted a preliminary investigation of the application of microCT methods to the study of cortical and trabecular bone structure in a small sample of pneumatic and apneumatic thoracic vertebrae. The sample consisted of two similar-sized anatids, Aix sponsa (n = 7) and Oxyura jamaicensis (n = 5). Volumes of interest were created that contoured (outlined) the boundaries of the ventral cortical bone shell, the trabecular compartment and the whole centrum (cortical bone + trabecular bone), and allowed independent structural analysis of each volume of interest. Results indicated that bone volume fraction of the whole centrum was significantly higher in the apneumatic O. jamaicensis than in the pneumatized A. sponsa (A. sponsa = 36%, O. jamaicensis = 48%, P < 0.05). In contrast, trabecular bone volume fraction was similar between the two species. The ventral cortical bone shell was approximately 23% thinner (P < 0.05) in A. sponsa (0.133 mm) compared with apneumatic O. jamaicensis (0.172 mm). This case study demonstrates that microCT is a powerful non-destructive imaging technique that may be applied to the three-dimensional study of avian bone. The preliminary results suggest that pneumatic and apneumatic vertebrae of comparably sized avian species differ in relative bone volume, with the largest difference apparent at the level of the cortex, and not within trabecular bone. The presence of relatively thin cortices in pneumatic vertebrae is consistent with previous studies contrasting diaphyseal cortical bone between pneumatic and apneumatic long bones. Methodological issues related to this and any comparative microCT study of bone structure are discussed.

BMP-silk composite matrices heal critically sized femoral defects.

Clinical drawbacks of bone grafting prompt the search for alternative bone augmentation technologies such as use of growth and differentiation factors, gene therapy, and cell therapy. Osteopromotive matrices are frequently employed for the local delivery and controlled release of these augmentation agents. Some matrices also provide an osteoconductive scaffold to support new bone growth. In this study, silkworm-derived silk fibroin was evaluated as an osteoconductive matrix for healing critical sized mid-femoral segmental defects in nude rats. Four treatment groups were assessed over eight weeks: silk scaffolds (SS) with recombinant human BMP-2 (rhBMP-2) and human mesenchymal stem cells (HMSC) that had been pre-differentiated along an osteoblastic lineage ex vivo (Group I; pdHMSC/rhBMP-2/SS); SS with rhBMP-2 and undifferentiated HMSCs (Group II; udHMSC/rhBMP-2/SS); SS and rhBMP-2 alone (Group III; rhBMP-2/SS); and empty defects (Group IV). Bi-weekly radiographs revealed a progressive and similar increase in Group I-III mean defect mineralization through post-operative week (POW) 8. Radiographs, dual energy x-ray absorptiometry, and micro-computed tomography confirmed that Groups I-III exhibited similar substantial and significantly (p<0.05) greater defect mineralization at POW 8 than the unfilled Group IV defects which remained void of bone. No significant differences in Groups I-III defect healing at POW 8 were apparent using these same assays or mechanical testing. Histology at POW 8 revealed moderately good bridging of the parent diaphyseal cortices with woven and lamellar bone bridging islands of silk matrix in Groups I and III. Group II defects possessed comparatively less new bone which was most abundant adjacent to the parent bone margins. Elsewhere the silk matrix was more often enveloped by poorly differentiated loose fibrous connective tissue. Group IV defects showed minimal new bone formation. None of the treatment groups attained the mean mineralization or the mean biomechanical strength of identical defects implanted with SS and pdHMSCs alone in a previous study. However, addition of rhBMP-2 to SS prompted more bone than was previously generated using udHMSC/SS or SS alone. These data imply the clinical potential of silk scaffolds and rhBMP-2 as composite osteopromotive implants when used alone or with select stem cell populations. Additional studies in larger species are now warranted.