Molecular characterization and phylogenetic analysis of Marek's disease virus in chickens from Ogun State, Nigeria.

Marek's disease (MD) is caused by oncogenic MD virus serotype 1 (MDV1) and is characterized by lymphoproliferative lesions resulting in high morbidity and mortality in chickens. Despite being ubiquitous on poultry farms, there is a dearth of information on its molecular characteristics in Nigeria. This study aimed at characterizing three virulence genes (Meq, pp38, and vIL-8) of MDV1 from chickens in Ogun state, Nigeria. Blood, feather quill, and tumour samples of chickens from different commercial poultry farms in Ogun State were pooled, spotted on 107 FTA cards, and screened for MDV1 by polymerase chain reaction (PCR). Phylogenetic analysis was carried out to compare Nigerian MDV1 Meq, pp38, and vIL-8 genes sequences with the published references. Thirteen samples were MDV1-positive and the Meq, as well as pp38, and vIL-8 genes from the different samples were 100% identical. The Meq genes contained 339 amino acids (aa) with three PPPP motifs in the transactivation domain and two interruptions of the PPPP motifs due to proline-to-arginine substitutions at positions 176 and 217 resulting in a 20.88% proline composition. Phylogenetic analysis revealed that the Meq gene clustered with strains from Egypt and very virulent ATE2539 strain from Hungary. Mutations were observed in the pp38 protein (at positions 107 and 109) and vIL-8 protein (at positions 4 and 31). Based on the molecular analysis of the three genes, the results indicate the presence of MDV1 with virulence signatures; therefore, further studies on in vivo pathotyping of Nigerian MDV1 from all states should be performed.RESEARCH HIGHLIGHTS Meq, pp38 and vIL-8 genes were 100% identical between Nigerian MDV strains.Proline content in Nigerian meq gene was 20.88% with two PPPP motifs interruptions.Meq, pp38 and vIL-8 genes of Nigerian MDV were similar to Egyptian and Indian strains.

Paediatric Trauma Presentations in a Teaching Hospital in Lagos, Nigeria: Epidemiology and Predictor of Mortality.

INTRODUCTION: Paediatric trauma remains a major health challenge worldwide. It remains a major reason for hospitalization among children and adolescents around the world, with resultant death or disability. This study was aimed to determine the epidemiology, pattern and outcomes of paediatric injuries presenting at a teaching hospital in Lagos, South-west Nigeria. PATIENTS AND METHODS: This was a prospective observational hospital based study conducted on all paediatric trauma patients below 18 years, who presented at the accident and emergency room of the Lagos University Teaching Hospital (LUTH) over a period of thirteen months. Data analysis was done with Stata v13 (StataCorp. Texas. USA). RESULTS: A total of 154 patients sustained 250 documented injuries. The mean age was 6.8 ± 4.6 years. Male to female ratio was 1.5:1. Children aged 8 years were mostly affected. There was significant statistical association between age of child at injury and the place of injury. (p = 0.021) Most injuries (51.3%) occurred at home followed by the road. Falls accounted for 72 cases (46.8%). Traumatic brain injury was the most common injury sustained. Injuries at home peaked at 5pm and extended to 7pm while injuries from road traffic accidents peaked at two periods; between 7am and 8am and 4pm. Paediatric trauma score predicted death accurately. The crude mortality rate was 5.8%. CONCLUSION: Paediatric trauma scourge is still a health concern. School age children are mostly affected by trauma. Falls were the most common cause of trauma in children and most falls occurred in the home environment. Injuries from road traffic accidents accounted for majority of deaths. The paediatric trauma score predicts mortality in injured children and should be routinely used.

INTRODUCTION: Les traumatismes pédiatriques demeurent un problème de santé majeur dans le monde entier. Il demeure une raison majeure d'hospitalisation chez les d'hospitalisation chez les enfants et les adolescents du monde entier, avec des décès ou un handicap résultant . Cette étude avait pour but de déterminer l'épidémiologie, et les résultats des blessures pédiatriques présentées dans un hôpital universitaire de Lagos, dans le sud-ouest du Nigeria. PATIENTS ET MÉTHODES: Il s'agit d'une étude prospective d'observation menée dans un hôpital sur tous les cas de blessures pédiatriques traumatisés de moins de 18 ans, qui se sont présentés au service des accidents et des urgences du accident et des urgences du Lagos University Teaching Hospital (LUTH) sur une période de treize mois. L'analyse des données a été réalisée avec Stata v13 (StataCorp. Texas. USA). RÉSULTATS: Au total, 154 patients ont subi 250 blessures documentées. L'âge moyen était de 6,8 ± 4,6 ans. Le rapport hommes/ femmes était de 1,5:1. Les enfants âgés de 8 ans étaient les plus touchés. Il existe une association statistique significative entre l'âge de l'enfant au moment de la blessure et le lieu de la blessure. (p = 0,021) La plupart des blessures (51,3 %) sont survenues à la maison, suivies par la route. Les chutes ont représenté 72 cas (46,8 %). Les traumatismes cérébraux est la blessure la plus fréquente. Les blessures à domicile ont atteint un pic à 17 heures et se prolongeant jusqu'à 19 heures, tandis que les blessures dues à des accidents de la route ont atteint un pic à deux périodes : entre 6h et 7h59 et à 16h. Le score de traumatisme pédiatrique permettait de prédire le décès avec précision. Le taux de mortalité brut était de 5,8 %. CONCLUSION: Le fléau des traumatismes pédiatriques reste un problème de santé. Les enfants d'âge scolaire sont les plus touchés par les traumatismes. Les chutes étaient la cause la plus cause la plus fréquente de traumatisme chez les enfants et la plupart des chutes se sont produites dans le environnement. Les blessures dues aux accidents de la route représentent la majorité des décès. Le score de traumatisme pédiatrique permet de prédire la mortalité chez les enfants blessés et devrait être utilisé de manière systématique. Mots clés: Traumatisme, Pédiatrie, Blessures, causes, mortalité, Enfance, Nigeria.

Hypertension and its Clinical Correlates in a Rural Community in South Western Nigeria.

BACKGROUND: Hypertension is the commonest cardiovascular risk factor globally and is a cause of untold morbidity and mortality. However, its clinical correlates at the community level have not been well elucidated. METHODS: History taking, anthropometric measurements, electrocardiograms and laboratory investigations were done for all the study subjects. Ethical approval was obtained from the institution's ethical body. Analysis was done using SPSS version 20. Two hundred people were recruited for the study. The prevalence of hypertension in the community was 58.5% with 31(15.5%) being newly diagnosed. The Body Mass Index [BMI] (28.2±6vs 25.6±5.3; P=0.003),Waist-Hip ratio (0.9±0.08 vs 0.86±0.06; p= 0.001), total cholesterol (5.675±1.8 vs 4.6±1.7, P=0.000), triglycerides (1.19±0.85 vs 0.91±0.59; p=0.019), LDL cholesterol (3.38±1.6 vs 2.66±1.5; p=0.002), heart rate (82.4±15.8 vs 76.8±11.2; p=0.018) QRS duration (84.8±13.4 vs 80.5±11.2; p=0.040), and QTc (0.423±0.041 vs 0.402±0.035; p=0.001) were higher in those with hypertension. NYHA functional class was worse in hypertensives (p=0.041). Prevalence of left ventricular hypertrophy (LVH) in hypertensives ranged from 2.6 to 48.2%, depending on the criteria used. Systolic blood pressure, pulse pressures, HDL levels and hip circumferences were higher in those with electrocardiographic LVH. Systolic blood pressure (OR:1.045, P=0.006; CI: 1.013-1.079) and a normal BMI (OR: 0.159, p= 0.004; CI: 0.045-0.559) were the independent predictors of LVH in this study. CONCLUSION: The prevalence of hypertension is rising, even in rural populations, with accompanying LVH, higher QTc and florid cardiovascular risk factors. It is therefore imperative to tighten the reins of control of blood pressure and other cardiovascular risk factors before the cardiovascular morbidity and mortality explode in the rural communities.

CONTEXTE: L'hypertension est le facteur de risque cardiovasculaire le plus courant dans le monde et est une cause de morbidité et de mortalité indicibles. Cependant, ses corrélats cliniques au niveau communautaire n'ont pas été bien élucidés. MÉTHODES: Des antécédents, des mesures anthropométriques, des électrocardiogrammes et des examens de laboratoire ont été effectués pour tous les sujets de l'étude. L'approbation éthique a été obtenue de l'organe déontologique de l'institution. L'analyse a été effectuée à l'aide de la version 20 de SPSS. Deux cents personnes ont été recrutées pour l'étude. La prévalence de l'hypertension dans la communauté était de 58,5%, 31 (15,5%) nouvellement diagnostiqués. L'indice de masse corporelle [IMC] (28,2 ± 6 vs 25,6 ± 5,3; P = 0,003), le rapport taille-hanches (0,9 ± 0,08 vs 0,86 ± 0,06; p = 0,001), le cholestérol total (5,675 ± 1,8 vs 4,6 ± 1,7, P = 0,000), triglycérides (1,19 ± 0,85 vs 0,91 ± 0,59; p = 0,019), cholestérol LDL (3,38 ± 1,6 vs 2,66 ± 1,5; p = 0,002), fréquence cardiaque (82,4 ± 15,8 vs 76,8 ± 11,2; p = 0,018) Durée du QRS (84,8 ± 13,4 vs 80,5 ± 11,2; p = 0,040) et l'intervalle QTc (0,423 ± 0,041 vs 0,402 ± 0,035; p = 0,001) étaient plus élevés chez les personnes souffrant d'hypertension. La classe fonctionnelle NYHA était pire chez les hypertendus (p = 0,041). La prévalence de l'hypertrophie ventriculaire gauche (LVH) chez les hypertendus variait de 2,6 à 48,2%, selon la critères utilisés. La pression artérielle systolique, les pressions de pouls, les taux de HDL et la circonférence de la hanche étaient plus élevés chez les personnes atteintes de LVH électrocardiographique. La pression artérielle systolique (OR: 1,045, P = 0,006; IC: 1,013­1,079) et un IMC normal (OR: 0,159, p = 0,004; IC: 0,045­0,559) étaient les prédicteurs indépendants de l'HGV dans cette étude. CONCLUSION: La prévalence de l'hypertension est en hausse, même dans les populations rurales, accompagnée de LVH, d'un QTc plus élevé et de facteurs de risque cardiovasculaires florissants. Il est donc impératif de resserrer les rênes du contrôle de la pression artérielle et des autres facteurs de risque cardiovasculaire avant que la morbidité et la mortalité cardiovasculaires n'explosent dans les communautés rurales. Mots clés: Hypertension, hypertrophie ventriculaire gauche, indice de masse corporelle, HDL.

Risk of Obstructive Sleep Apnoea among Adults in a Rural Community in Southwest Nigeria.

BACKGROUND: Obstructive sleep apnoea (OSA) is a common medical condition which has long been recognized as a major contributor to morbidity and mortality in developed countries but that remains underdiagnosed, particularly in rural communities. This study aimed to assess the prevalence of adults who have a high risk of obstructive sleep apnoea in a sample of adults living in Ejigbo, a rural community in south western Nigeria. METHODS: This was a community-based cross-sectional descriptive study done to assess the prevalence of high risk of obstructive sleep apnoea in adult residents of the community using the STOP-BANG questionnaire. Data collected include socio-demographic characteristics, anthropometric measurements and blood pressure. A blood sample was also taken for lipid profile. Factors associated with a high risk of obstructive sleep apnoea were identified. RESULTS: The study involved 257 participants out of which 88 (34.2%) had a high risk of OSA. Risk of obstructive sleep apnoea was significantly associated with male sex (p<0.001), age (p<0.001), body mass index (BMI) (p=0.001), neck circumference (p<0.001), cigarette smoking (p=0.039) and low density lipoprotein (p=0.043). CONCLUSION: Obstructive sleep apnoea is relatively common in the study area. This calls for urgent preventive measures to stem the tide and mitigate the associated morbidity and mortality.

Comparing Asthma Control Test with Global Initiative for Asthma Defined Control in Nigerian Adult Asthmatics: A Prospective Cross-sectional study.

BACKGROUND: Assessment of control is central to asthma management. The Asthma Control Test (ACT) and Global Initiative for Asthma (GINA) defined control are commonly used measures of asthma control. This study examined the agreement between the ACT and GINA defined control and determined the best cut-off point of ACT to predict GINA level of control. METHODS: It was a cross-sectional study of 82 consecutive [72% females, age 44 (IQR) 29-60 years] asthmatic patients in a tertiary teaching hospital. We compared ACT with GINA defined control using Cohen's kappa and receiver operating characteristics curve was computed to determine sensitivity and specificity. RESULTS: There was fair to moderate level of agreement between ACT and GINA defined control (kappa 0.34 to 0.46). To detect GINA-defined controlled asthma, the ACT cut-off point of =20 had a sensitivity of 81%, specificity of 74%, a positive predictive value of 52% and negative predictive value of 92%, with an area under the receiver operating characteristics curve(AUC) value of 0.82 [95% confidence interval (CI): 0.72-0.90]. ACT scores of = 19 predicted GINA-defined uncontrolled asthma with sensitivity of 87%, specificity of 51%, positive predictive value of 41%, negative predictive value of 91% with AUC values of 0.75 (95% CI: 0.75-0.84). CONCLUSION: In Nigerian asthmatics, ACT scores of =20 and =19 are useful for identifying patients with controlled and uncontrolled asthma respectively, as defined by GINA 2014 criteria. However, the former is more predictive than the latter.

Effect of dietary supplementation with clay-based binders on biochemical and histopathological changes in organs of turkey fed with aflatoxin-contaminated diets.

This study was carried out to investigate the effect of dietary supplementation with molecular or nano-clay binders on biochemical and histopathological examination of organs of turkeys fed diets contaminated with aflatoxin B1. Two hundred and sixteen unsexed 1-day-old British United Turkeys were randomly allotted to nine diets in a 3 × 3 factorial arrangement of diets supplemented with no toxin binder, molecular toxin binder (MTB) and nano-clay toxin binder, each contaminated with 0, 60 and 110 ppb aflatoxin B1 respectively. There were three replicates per treatment with eight turkeys per replicate. Biochemical analyses, organ weights and histopathological changes of some organs were examined at the end of the study which lasted for 84 days. Turkeys fed diets supplemented with molecular and nano-binders showed higher (p < 0.001) total serum protein, reduced (p < 0.001) serum uric acid and GGT concentration values when compared with those fed aflatoxin-contaminated diets supplemented with no binder. Turkeys fed aflatoxin-contaminated diets supplemented with no binder had increased (p < 0.001) AST and ALT concentration when compared with other treatments. The heaviest (p < 0.001) liver and intestinal weight was noticed with turkeys fed diets supplemented with no binder and contaminated with 110 ppb aflatoxin B1 . Pathologically, there was no visible morphological alteration noticed in all turkeys fed uncontaminated diets and nano-clay-supplemented group. Hepatic paleness, hepatomegaly and yellowish discolouration of the liver were observed with turkeys fed diets containing no binder but contaminated with 60 and 110 ppb aflatoxin B1. Intestinal histopathological changes such as goblet cell hyperplasia, villous atrophy and diffuse lymphocytic enteritis were more prominent in turkeys fed diets containing no toxin binder and MTB. In conclusion, there were improved biochemical parameters and reduced deleterious effects of aflatoxin B1 in turkeys fed diet supplemented with clay binders. However, the improvement was more conspicuous in the nano-clay-supplemented group than molecular clay group.

FLUORIDE CONTENT OF COMMERCIALLY PACKAGED SACHET WATER IN IBARAPA LAND, SOUTHWEST, NIGERIA.

Background: Fluoride concentration (F conc) in water is a major determinant for the occurrence of dental caries and dental fluorosis. In most homes of rural communities, especially in developing countries, there is a major reliance on sachet water as an alternate low-cost drinking water. This study aims to determine the fluoride concentrations of common commercially packaged sachet water in Ibarapa land, Southwestern, Nigeria. Methods: An observational study was conducted using convenience sampling of all commercially packaged sachet water for drinking in Ibarapa land, Southwestern, Nigeria. Thirteen samples of sachet water were obtained from Ayete (2), Igboora (6) and Lanlate (5). F conc of the sachet water was determined in triplicate using the Fluoride Ion-Selective Electrode by direct analysis. Temperature and pH of water were also measured. Results were analysed using SPSS version 23. Results: The F conc, temperature and pH range were 0.03 mgF/l - 2 mgF/l, 26.4°C - 27.2°C and 6.90 - 8.19 respectively. The minimum F conc in all samples was 0.03ppm at pH 6.90 while maximum was 2ppm at pH 7.78. F conc in 2 (15.4%), 8 (61.5%) and 3 (23.1%) water samples were 0.5-0.6 mgF/l, <0.5 mgF/ l and >0.6 mgF/l respectively. No sachet water had fluoride levels printed on their labels. Conclusion: F conc of the sachet water varied, with the majority of samples having low concentrations. Attention needs to be paid to both low levels and high levels of fluoride in drinking water to ensure safety and protective benefit.

Chemical composition and in sacco degradability of four varieties of cassava leaves grown in Southwestern Nigeria in the rumen of sheep.

The nutritive value of leaves of four varieties of cassava (MS 6, TMS 30555, Idileruwa and TMS 30572) were studied through analysis of their chemical components and degradability of their dry matter (DM) and crude protein (CP) in the rumen of sheep. Results of the chemical analyses showed that the leaves of the four varieties contained different proportions of organic matter which was significantly (P < 0.05) highest in TMS 30572 with value of 935 g/kg DM, while CP (gram per kilogramme DM) was significantly highest in TMS 30555 (240), followed by MS 6 (235), TMS 30572 (208) and least in Idileruwa (177). Mean metabolisable energy (megajoules per kilogramme DM) was significantly (P < 0.05) highest in TMS 30572 (8.2) and similar with Idileruwa (8.0) but different from TMS 30555 and MS 6, respectively (7.8 and 7.6). The mineral contents (gram per kilogramme DM) showed that leaves of MS 6 and Idileruwa had the highest concentrations of K (2.86) and a significantly lowest value (1.83) in TMS 30555. Also, the highest concentration of Ca and Fe (6.81 and 6.23) was recorded in MS 6. The highest Ca:P of 3.20 was obtained in TMS 30555. DM degradation characteristics and effective degradability varied significantly (P < 0.05) and were consistently highest in TMS 30572. The washing loss (a) ranged from 15.9% in MS 6 to 21.3% in TMS 30572. TMS 30572 tended to have higher (P = 0.546) insoluble but fermentable fraction (b) than all other varieties. Moreover, the potential degradability (a + b) tended to be higher (P = 0.041) in TMS 30572 (69.5%) followed by TMS 30555 (67.1%) and the lowest was in Idileruwa (42.7%). The highest effective degradability was recorded in TMS 30572 (63.9%) and the lowest in Idileruwa (40.7%). The degradation rate constants (c) of Idileruwa was significantly higher (P = 0.001) than those of MS6, TMS 30555 and TMS 30572. The results generally indicated that the leaves could be ranked for their potential feeding value as TMS 30572 (71.5%) > MS6 (65.8%) > Idileruwa (63.0%) > TMS 30555 (50.4%). It is therefore concluded from this study that leaves of TMS 30572 and MS 6 have good potential as feed resources for ruminant animals and could be used in ruminant feeding as protein source ingredient.

Seroprevalence of leptospirosis in domesticated Asian elephants (Elephas maximus) in north and west Thailand in 2004.

Serum samples from Asian elephants (Elephas maximus) in the Kanchanaburi, Chiang Mai and Lampang provinces of Thailand were tested using the microscopic agglutination test against 22 serovars of Leptospira interrogans. A titre of more than 1:100 was used as evidence of infection. In northern Thailand, the seroprevalence was 58 per cent and the prevalent serovars were Leptospira interrogans serovar Sejroe, Leptospira interrogans serovar Tarassovi, Leptospira interrogans serovar Ranarum and Leptospira interrogans serovar Shermani. In western Thailand, the seroprevalence was 57 per cent and the prevalent serovars were L Tarassovi, L Sejroe, L Ranarum, Leptospira interrogans serovar Bataviae and L Shermani. These results were similar to studies in domestic livestock and stray dogs in the Bangkok district. Among the elephants from Kanchanaburi there were significant associations between seropositivity and between the camp and between the prevalent serovars and the camp.

Risk factors associated with mental illness in Oyo State, Nigeria: a community based study.

BACKGROUND: The main objective of this study was to determine the prevalence and factors associated with mental illness in Oyo State at community level using the general health questionnaire as a screening tool. METHOD: This cross-sectional, community- based survey was carried out among adults in three randomly selected LGAs using multi-stage sampling technique. RESULTS: A total of 1105 respondents were assessed in all. The overall prevalence of psychiatric morbidity in Oyo state Nigeria was found to be 21.9%, (18.4% in the urban areas and 28.4% in the rural areas, p = 0.005). Young age < or = 19 yrs (X2 = 20.41, p = 0.00013), Unemployment (X2 = 11.86 p = 0.0005), living condition below average (X2 = 12.21, p = 0.00047), physical health (X2 = 6.07, p = 0.014), and large family size (X2 = 14.09 p = 0.00017) were associated with increase risk for psychiatric morbidity. Following logistic regression analysis, Unemployment (C.I = 1.18-3.70, OR -2.1) and living conditions perceived to be above average (C.I = 1.99-5.50, OR-3.3) were significant predictors of mental illness while family size less than 6 (C.I = 0.86-0.97, OR-0.91) was protective. CONCLUSION: The teenagers and the rural populations are in greater need of mental health promotional services. Family planning should be made freely available in order to reduce the family size and hence incidence of mental illness in the African population.

The ultrastructure of the peri-articular osteophytes - an evaluation by scanning electron microscopy.

OBJECTIVE: Osteophytes are intra-articular osteochondral tissues, which are usually found at the margins of degenerating synovial joints. The aetiology or pathogenesis of this tissue has been a subject of protracted debate. The aim of this study was to offer a possible aetiology and or pathogenesis of this expendable yet important osteochondral tissue using the scanning electron microscopy to evaluate the structure of the cartilage mantle of osteophytes and the relationship of this mantle with that of the adjoining normal articular cartilage. METHODS: Sections of periarticular osteophytes and osteophyte-normal articular cartilage composite tissues were obtained during total knee replacement for osteoarthritis (OA). These sections were routinely processed and examined using the scanning electron microscope with emphasis on the osteophytic cartilage mantle and the merger of the osteophyte and the adjoining normal articular cartilage. RESULTS: The cartilage mantle of osteophytes was found to be thinner but continuous with that of the adjoining normal articular cartilage. However, a longitudinal bar of acellular tissue was found to separate the subchondral bones of both tissues. The cellular (chondrocyte) arrangement in the osteophytic cartilage was similar to that of the adjoining normal articular cartilage. In addition, in the superficial layer, there was looping of collagen fibres between the normal articular cartilage mantle and that of the osteophytic tissues. CONCLUSION: The continuity between the cartilage mantle of osteophytes and the adjoining normal articular cartilage may suggest that in the formation of osteophytes, the chondrocytes from the adjoining normal articular cartilage greatly influence the mesenchymal tissue precursor of osteophyte to differentiate along a chondrocytic pathway initially. With subsequent vascular invasion probably from the periosteum, the neocartilage develops a bony core with a completely separate blood supply from that of the adjoining subchondral bone.

Sociodemographic characteristics of anaemic gravidae at booking: a preliminary study at Llesha, Western Nigeria.

BACKGROUND: Anaemia in pregnancy is a significant cause of direct and indirect morbidity and mortality to both the pregnant mother and her fetus. The prevalence however remains undetermined in many parts of Africa. The study aims at determining the prevalence of anaemia and sociodemographic characteristics of anaemic pregnant women in a Nigerian tertiary obstetric care centre. METHODS: A cross-sectional study involving all pregnant women that registered for ante-natal care between 1st January 2001 and 30th of June 2001 in Wesley Guild Hospital Unit of Obafemi Awolowo University Teaching Hospitals Complex, Ile-lfe. RESULTS: Prevalence of anaemia among the pregnant women during the period of study was 62.2%. Two percent of the women had severe anaemia. Parity and gestational age at booking significantly influenced the prevalence of anaemia. CONCLUSION: Prevalence of anaemia among pregnant women in developing world is still unacceptably high, and it calls for improvement in standard of living for our pregnant women.

Investigation of the torque-tension characteristics of a flanged external fixator pin.

The torque-tension characteristics of standard, conical and flanged external fixator pins and a cortical screw were compared using a commercially available testing apparatus. The flanged pin and the screw were similar in behaviour, and converted torque into tension more efficiently than conical and standard external fixator pins.

Pin-hole shear stresses generated by conical and standard external fixation pins.

Pin-hole shear stresses generated by tapered (conical) and untapered (standard) external fixator pins were compared using a photoelastic technique. The results show that shear stresses progressively increase as a conical pin is inserted but remain the same for the standard pin irrespective of the depth of insertion.

Bending stiffness of conical and standard external fixator pins.

The bending stiffnesses of a conical and a standard external fixator pin have been compared. The pins were inserted into pilot holes in a piece of teak hardwood and loads of different magnitudes were applied at a fixed moment arm. Force-deflection curves were obtained for each pin, and stiffness (newtons per metre) and percentage stiffness reduction were calculated for each pilot hole size. The results show that deflection increased (i.e. stiffness decreased) with increasing force or diameter of pilot hole. This loss of stiffness was linear for the standard pin but was bimodal for the conical pin.

Comparison of the stresses generated at the pin-bone interface by standard and conical external fixator pins.

The stresses generated at the pin-bone interface by external fixator pins have been compared using finite element analysis. The results show that higher stresses are generated by conical pins compared with standard pins of the same diameter. This raises the possibility that the rate of pin loosening may be higher for conical pins.

External fixation of upper limb fractures: the effect of pin offset on fixator stability.

A Shearer fracture fixator was applied to a hardwood model using various pin configurations and load-displacement curves were obtained from compressive and bending loads. The results show that offsetting the pins by 60 degrees increases rigidity by a factor of 4-5.

Localisation of bone-forming cells during fracture healing by osteocalcin immunocytochemistry: an experimental study of the rabbit tibia.

An immunocytochemical method was used to localise osteocalcin-producing cells during fracture healing in a rabbit model. In preliminary studies, tibial growth plates from young rabbits were used as a source of new bone formation, in order to determine the optimal tissue preparatory techniques. In the present study, a tibial shaft fracture was created in adult rabbits to study closed fracture healing. An indirect peroxidase method was used to stain paraffin-embedded tissue sections for osteocalcin. Osteocalcin-producing cells were positively identified at the periosteal and endosteal surfaces near the fracture site. Osteocalcin staining was not demonstrated in the surrounding soft tissues. At the interface between newly formed bone trabeculae and the cartilage layer within the callus, chondrocytic cells consistently showed localisation of osteocalcin. Within cartilaginous areas of the callus, some chondrocytes showed positive staining for osteocalcin. These cells were often seen in the proximity of blood vessels. The findings suggest that during fracture healing, under certain conditions, chondrocytes are capable of producing osteocalcin and thus could be considered capable of possible transformation into osteoblasts.

The value of shoulder distension arthrography with intraarticular injection of steroid and local anaesthetic: a follow-up study.

A series of 51 patients, seen in Leicester, with "frozen shoulder", and referred for arthrographic examination, were assessed both before and after distension arthrography, using air and a low-osmolar contrast media combined with a steroid and local anaesthetic injection. 38 attended for further assessment at up to 6 months later. 16 patients were found to have a rotator cuff tear. There was no significant change in the mean range of active movement in the patients with rotator cuff tears, but symptomatic improvement ensued in 44% of cases. In those found to have no rotator cuff tear, and external rotation of less than 35 degrees, a significant improvement in range of movement was seen. While those with less limitation of external rotation showed no change in their range of movement, they did experience symptomatic improvement in 73% of cases. We conclude that shoulder distension arthrography, with steroid and local anaesthetic injection, may be of symptomatic benefit in patients with frozen shoulder and without a rotator cuff tear, while only those with external rotation of less than 35 degrees are likely to improve their range of motion.