Are there associations between hip geometry and bone quality? An analysis on 3074 adults from a general population.

INTRODUCTION: Patients with reduced bone mineral density and altered hip geometry are susceptible for hip pathologies. Knowledge on associations between bone properties and hip geometric parameters might facilitate identification of patients at risk for hip pathologies. The aim of the present study was to identify associations of bone properties assessed by quantitative ultrasound (QUS) at the heel and hip geometric parameters like center-edge angle (CE), neck-shaft angle (NSA) and alpha angle. MATERIALS AND METHODS: Hip geometric parameters (CE, NSA and alpha angle) of 3074 participants from the population-based Study of Health in Pomerania were assessed on magnetic resonance imaging. QUS was performed on both calcanei providing broadband ultrasound attenuation (BUA), speed of sound (SOS) and stiffness-index. Based on the stiffness-index the individual osteoporotic fracture risk (low, moderate or high) was determined. Associations between QUS-based and hip geometric parameters were calculated in linear regression models adjusted for age, sex, body height and weight. Interactions of QUS markers with age and sex on hip geometric parameters were tested. RESULTS: Significant inverse associations between BUA (ß = - 0.068), SOS (ß = - 0.024) as well as stiffness-index (ß = - 0.056) and CE were present, while fracture risk was positively associated with CE (ß for high = 1.28 and moderate = 2.54 vs. low fracture risk). Interactions between BUA and sex as well as between SOS and age were detected in the models for CE. Furthermore, there was an inverse relation between fracture risk and NSA that was restricted to the moderate risk (ß for moderate vs. low fracture risk = - 0.60). There were no significant associations between QUS parameters and alpha angle. CONCLUSIONS: In the general population, several associations between QUS-based bone properties or fracture risk and hip geometry are present. Less dysplastic hips had a lower stiffness-index and a higher fracture risk, whereas more valgus hips had a lower fracture risk.

Reference values and influencing factors of the glenohumeral subluxation index: a study on 3004 participants.

BACKGROUND: The primary objective of this study was to examine the glenohumeral subluxation index (GHSI) in a large general population cohort and to define reference values. Glenohumeral subluxation is important in the development and prediction of pathological states of the shoulder joint and in total shoulder arthroplasty. Therefore, another objective was to examine the influence of age, sex, body mass index, and body height and weight on GHSI. METHODS: GHSI according to Walch was measured on bilateral magnetic resonance imaging of 3004 participants of the Study of Health in Pomerania (SHIP, aged 21-90 years). SHIP drew a sample of the adult general population of Pomerania (Northeastern Germany). Reference values for GHSI were assessed by quantile regression models. Associations of sex, age, and anthropometric markers with the GHSI were calculated by linear regression models. RESULTS: A reference range between 42% and 55% for men with a mean of 49% ± 4% was defined, while the upper reference limit for women was 1% higher (mean, 50% ± 4%). Age was inversely associated with the GHSI in males (P < 0.001), while no significant association in females was observed (P = .625). Body weight and body mass index were positively associated (P < .001) without effect modification by sex. Heavy mechanical oscillations on the upper extremity showed no significant association with GHSI (P = .268). CONCLUSION: The reference values for GHSI were expanded to a range of 42%-57% on magnetic resonance imaging. Several associations between GHSI and anthropometric properties are present. According to these associations, adjusted formulas are provided to enable individual, patient-specific diagnostics and therapy. Nevertheless, the clinical picture cannot be neglected.

Single and multi-pulse based X-ray photon correlation spectroscopy.

The ability of pulsed nature of synchrotron radiation opens up the possibility of studying microsecond dynamics in complex materials via speckle-based techniques. Here, we present the study of measuring the dynamics of a colloidal system by combining single and multiple X-ray pulses of a storage ring. In addition, we apply speckle correlation techniques at various pulse patterns to collect correlation functions from nanoseconds to milliseconds. The obtained sample dynamics from all correlation techniques at different pulse patterns are in very good agreement with the expected dynamics of Brownian motions of silica nanoparticles in water. Our study will pave the way for future pulsed X-ray investigations at various synchrotron X-ray sources using individual X-ray pulse patterns.

Os acromiale: prevalence and associated patient-related factors-a population-based study of three thousand and fifty participants.

PURPOSE: The presence of os acromiale is of clinical relevance before performing shoulder surgery but ethnic differences and little information regarding associated factors seem to be present. Population-based studies to clarify these topics are essential so the purpose of this study was to assess the prevalence, anatomy, and associations of os acromiale in a general adult population. METHODS: Both shoulders of 3050 participants from the population-based Study of Health in Pomerania (SHIP) were assessed on magnetic resonance imaging (MRI). Associations with the os acromiale were calculated for sex, age, body height, body weight, and heavy mechanical oscillations on the upper extremity. RESULTS: In total, 1.9% (58/3050) had an os acromiale, while 21 were unilateral left, 23 were unilateral right, and 14 were bilateral. Sixty-eight meso-acromions, three pre-acromions, and one meta-acromion were detected. Os acromiale were more frequent in men (right side: p = 0.037, left side: p = 0.005). Overall, no differences in sides (p = 0.808), to participants' age (right: p = 0.993, left: p = 0.499), body height (right side: p = 0.241, left side: p = 0.154), and the exposure to heavy mechanical oscillations on the upper extremity (right: p = 0.054, left: p = 0.117) were detected. CONCLUSION: Our results support the genetic theory for the aetiology of the os acromiale due to the lower prevalence of the os acromiale in north-eastern Germany compared to the worldwide prevalence (1.9 to 7%) and the lacking association to lifestyle, age, gender, or sides. Additionally, it is important to be aware of possible os acromiale before surgery.

Increase in Bone Mass Before Onset of Type 1 Diabetes Mellitus in Rats.

BACKGROUND/AIM: The typical insulin deficiency in type 1 diabetes mellitus has general effects on metabolism and also affects bone quality. MATERIALS AND METHODS: Two diabetic rat lines (BB/OK; BB.6KWR) and two non-diabetic rat strains (KWR and BB.14+18KWR), as control group, were included in the study. Bone mineral density, bone mineral content and body structure measurements were performed. The measurements took place before the onset of diabetes mellitus Results: A comparison of the groups showed increased bone density values of the diabetic rats in relation to the control groups. A new finding of increased bone density in the diabetic rats occurs. CONCLUSION: Diabetic rats showed no osteoporotic bone metabolism before the onset of clinically relevant type 1 diabetes mellitus, but rather increased bone metabolic activity.

Cold atmospheric plasma inhibits the growth of osteosarcoma cells by inducing apoptosis, independent of the device used.

Osteosarcoma (OS) is the most common tumor of the musculoskeletal system. Recently, cold atmospheric plasma (CAP) has been regarded as a promising anti-oncogenic therapy. Previous experimental studies have demonstrated that CAP treatment results in significant growth inhibition of human sarcoma and is able to induce apoptosis. However, due to device-specific parameters, there is a large variability in the antitumor effects of different CAP sources. In the present study, the cellular effects of CAP treatment from two different CAP devices were investigated and their pro-apoptotic efficacy was characterized. The OS cell lines, U2-OS and MNNG/HOS, were treated with two CAP devices, kINPen MED and MiniJet-R. Control groups were treated with argon. The anti-proliferative effect of each treatment was demonstrated using cell counting and the activation of apoptotic mechanisms was determined using Comet, TUNEL and Caspase-3/Caspase-7 assays. The results revealed that treatment of both OS cell lines with the two CAP sources resulted in significant inhibition of cell growth. Subsequently, the activation of Caspases and the induction of apoptotic DNA fragmentation was demonstrated. The biological effects of each CAP source did not differ significantly. The treatment of OS cells with CAP lead to an induction of apoptosis and a reduction of cell growth. Therefore, the biological effects of CAP appear to be general as the two devices of different design produced highly comparable cell responses. Therefore, the type of device used does not seem to affect the efficacy of CAP-based antitumor therapy.

The neck-shaft angle: an update on reference values and associated factors.

Background and purpose - The neck-shaft angle (NSA) is valuable for diagnostics and therapy of the hip, but current reference values derive mostly from studies on anatomic specimens, small cohorts, or are hospital-based. Moreover, associated factors such as age, sex, or anthropometric data have rarely been considered. Therefore, we determined associated factors for NSA and reassessed the historical reference values in a general adult population.Methods - NSAs on both sides of 3,226 volunteers from the population-based Study of Health in Pomerania (SHIP) were measured with MRI. SHIP drew a representative sample of the population of Pomerania (northeastern Germany). NSAs were compared with sex, age, and anthropometric data by bivariable linear regression models. Reference values were assessed by quantile regressions for 2.5th and 97.5th percentiles.Results - The mean NSA was 127° (SD 7), while men had a lower NSA than women (95% confidence interval [CI] 0.4°-1.4°). The reference range was 114°-140°. Age was inversely associated with NSA (CI -0.2 to -0.1). Body height was positively associated with the NSA, while BMI and waist circumference showed a negative association. There was no association between body weight and NSA.Interpretation - The historical lower limit of 120° might be too high, so the radiological prevalence of hip pathology might have been overestimated. The previously reported influence of age, sex, and body height on the NSA has been confirmed.

Biallelic inherited SCN8A variants, a rare cause of SCN8A-related developmental and epileptic encephalopathy.

OBJECTIVE: Monoallelic de novo gain-of-function variants in the voltage-gated sodium channel SCN8A are one of the recurrent causes of severe developmental and epileptic encephalopathy (DEE). In addition, a small number of de novo or inherited monoallelic loss-of-function variants have been found in patients with intellectual disability, autism spectrum disorder, or movement disorders. Inherited monoallelic variants causing either gain or loss-of-function are also associated with less severe conditions such as benign familial infantile seizures and isolated movement disorders. In all three categories, the affected individuals are heterozygous for a SCN8A variant in combination with a wild-type allele. In the present study, we describe two unusual families with severely affected individuals who inherited biallelic variants of SCN8A. METHODS: We identified two families with biallelic SCN8A variants by diagnostic gene panel sequencing. Functional analysis of the variants was performed using voltage clamp recordings from transfected ND7/23 cells. RESULTS: We identified three probands from two unrelated families with DEE due to biallelic SCN8A variants. Each parent of an affected individual carried a single heterozygous SCN8A variant and exhibited mild cognitive impairment without seizures. In both families, functional analysis demonstrated segregation of one allele with complete loss-of-function, and one allele with altered biophysical properties consistent with partial loss-of-function. SIGNIFICANCE: These studies demonstrate that SCN8A DEE may, in rare cases, result from inheritance of two variants, both of which exhibit reduced channel activity. In these families, heterozygosity for the dominant variants results in less severe disease than biallelic inheritance of two variant alleles. The clinical consequences of variants with partial and complete loss of SCN8A function are variable and likely to be influenced by genetic background.

Prevalence of benign osseous lesions of the spine and association with spinal pain in the general population in whole body MRI.

BACKGROUND: Benign osseous lesions of the spine are common but precise population prevalence estimates are lacking. Our study aimed to provide the first population-based prevalence estimates and examine association with back and neck pain. MATERIALS AND METHODS: We used data from the population-based Study of Health in Pomerania (SHIP). Whole-body MRI examinations (1.5 Tesla: T1, T2, and TIRM weightings) were available from 3,259 participants. Readings of the spinal MRI images were conducted according to a standardized protocol by a single reader (JS). The intra-rater reliability was greater than Kappa values of 0.98. Pain measures included the seven-day prevalence of spine pain and neck pain, and average spine pain intensity due to spine pain during the past three months. RESULTS: We found 1,200 (36.8%) participants with at least one osseous lesion (2,080 lesions in total). Osseous lesions were less common in men than in women (35.5% vs 38.9%; P = .06). The prevalence of osseous lesions was highest at L2 in both sexes. The prevalence of osseous lesions increased with age. Up to eight osseous lesions were observed in a single subject. Hemangioma (28%), and lipoma (13%) occurred most often. Sclerosis (1.7%), aneurysmal bone cysts (0.7%), and blastoma (0.3%) were rare. Different osseous lesions occurred more often in combination with each other. The association with back or neck pain was mostly negligible. CONCLUSION: Osseous lesions are common in the general population but of no clinical relevance for spinal pain. The prevalence of osseous lesions varied strongly across different regions of the spine and was also associated with age and gender. Our population-based data offer new insights and assist in judging the relevance of osseous lesions observed on MRIs of patients.

What Are the Reference Values and Associated Factors for Center-edge Angle and Alpha Angle? A Population-based Study.

BACKGROUND: The available evidence regarding normal ranges for the center-edge angle and the alpha angle derives from a few small studies, and associated factors such as sex and anthropometric factors have not been well evaluated. Knowing more about normal values for these parameters is critical, because this can inform decisions about when to perform elective hip preservation surgery. Population-level studies would provide considerable clarity on these issues, but to our knowledge, no such studies are available. QUESTIONS/PURPOSES: The purposes of this study were (1) to use MRI in patients of a population-based study to establish normal values for the alpha and center-edge angles in the normal adult hip; and (2) to determine whether age, sex, or anthropometric variables were associated with differences in these values. METHODS: We used MRI images (1.5 T) of 3226 participants of the Study of Health in Pomerania (SHIP). SHIP is a population-based study that started with 4308 participants in 1997. Participants were recruited randomly from official inhabitant data files as a stratified cluster sample of the population from a defined region in northeastern Germany. To ensure a representative epidemiologic cohort, stratification variables were sex, age, and city of residence. Between 2008 and 2012, 1094 of these participants underwent whole-body MRI with pelvic sequences in the second followup. In parallel, the next cohort, SHIP-Trend, started with the same protocol in which 2132 participants underwent MRI examination. Reference values were calculated by quantile regressions for the 2.5 and 97.5 percentiles. Associations with the demographic features sex, age, weight, height, body mass index (BMI), and waist circumference were analyzed by bivariate linear regression models. RESULTS: The mean center-edge angle was 31° (± 7°) with a corresponding calculated normal range of 17° to 45°. The mean alpha angle was 55° (± 8°) with a corresponding calculated normal range between 39° and 71°. Men (30° ± 7°) had a lower center-edge angle than women (32° ± 8°) (p < 0.001, ß = 1.4°; 95% confidence interval [CI], 0.9°-1.9°) and a higher alpha angle (57° ± 8° versus 52° ± 7°, p < 0.001, ß = 5.7°; 95% CI, 5.2°-6.3°). Moreover, a higher center-edge angle for the left side was found (33° ± 8° versus 30° ± 8°, p < 0.001, ß =3.2°; 95% CI, 3.0°-3.4°). In addition to sex, we found that age, height, waist circumference, and BMI affected both center-edge angle and alpha angle. Weight was associated with the alpha angle as well. Because of these associations, age- and sex-adjusted reference values with belonging formulas were calculated. CONCLUSIONS: The range of normal center-edge and alpha angles is quite wide. Therefore, only markedly abnormal angles may be associated with pathology. Moreover, center-edge angle and alpha angle are associated with age, sex, and anthropometric factors, which have to be taken into account for better interpretation. CLINICAL RELEVANCE: The association of abnormal radiographic values with true clinical hip pathology is tenuous at best. Assuming that a patient with an abnormal radiograph requires treatment is unwise. The clinical picture has to be substantial for therapeutic decisions.

Current management of open fractures: results from an online survey.

BACKGROUND: Open fractures are orthopaedic emergencies that carry a high risk for infection, non-union and soft tissue complications. Evidence-based treatment is impeded by the lack of high-quality evidence-based studies. The aim of this investigation was to elucidate the current practice of open fracture management in Germany and to determine major differences in treatment. METHODS: Surgeons were asked to complete an online questionnaire consisting of 45 items developed by an expert consensus. The first part covered questions on general principles of open fracture management. The second part included questions on soft tissue management, the preferred method of initial surgical stabilisation, microbiological testing, employment of pulsatile lavage and local antibiotics, antibiotic regimen, second-look operations, and blood testing. RESULTS: Of 653 respondents, 364 (65 %) completed the first part and 314 (48 %) completed the second part of the online survey. 55 % answered that a standard operating procedure for the diagnosis and treatment of patients with open fractures exists in their hospital. Only 25 % leave pre-hospitalisation applied dressings intact until arrival of the patient in the operating room, and 40 % make this decision depending on information provided by pre-hospitalisation emergency personnel. 84 % participants exclude the use of antibiotic-coated implants in the treatment of open fractures. The favoured stabilisation method in Gustilo type I fractures is definitive internal osteosynthesis and primary wound closure for 61 % of respondents. In Gustilo type II (74 %) and type III fractures (93 %), temporary external fixation is preferred. High-pressure pulsatile lavage is used by 22 % responding surgeons in Gustilo type I fractures, 53 % for type II fractures and 67 % for type III fractures. CONCLUSIONS: Open fracture management differs considerably among surgeons in Germany. Further studies are needed to deliver high-quality evidence concerning primary fracture stabilisation, soft tissue management and second-look operations. Existing evidence-based recommendations for general treatment, antibiotic prophylaxis and soft tissue management should be followed more strictly in clinical practice.

Needle decompression of tension pneumothorax: Population-based epidemiologic approach to adequate needle length in healthy volunteers in Northeast Germany.

BACKGROUND: Tension pneumothorax is one of the leading causes of preventable death in both military and civilian trauma patients. Needle decompression is recommended in trauma guidelines as an emergency procedure to relieve increased intrapleural pressure. The main reason for decompression failure is reported to be insufficient needle length in proportion to the chest wall thickness (CWT). So far, population-based epidemiologic data on CWT are missing. Therefore, it was the aim of this work to investigate the CWT in the second intercostal space, midclavicular line, based on magnetic resonance imaging data of a large population-based sample. The second aim of this study was to explore the potential risk of iatrogenic lesions caused by the proximity of the intended puncture track to the internal mammary artery. METHODS: A total of 2,574 healthy volunteers (mean [SD] age, 53.3 [13.9] years; range, 21-89 years) from the population-based cohort Study of Health in Pomerania (SHIP) were enrolled. CWT and the distance from the intended puncture track to the internal mammary artery were investigated with the chest sequences of a standardized 1.5-T whole-body magnetic resonance imaging. RESULTS: For all 5,148 measured sites in 2,574 volunteers, the mean (SD) CWT was 5.1 (1.4) cm. The mean body mass index was determined to be 27.7 kg/m. The CWT correlated significantly with body weight and body mass index. The internal mammary artery was located medial to the intended puncture site in all participants; the mean (SD) distance was 5.7 (0.7) cm on the right and 5.5 (0.7) cm on the left side. CONCLUSION: Based on the population-based epidemiologic data presented in this study, the use of a needle of 7 cm in length is recommended to decompress a tension pneumothorax in the second intercostal space in the midclavicular line, which might successfully decompress more than 90% of the participants in this study. When using this anterior approach at the anatomically correct puncture site, safety margin to the internal mammary artery is sufficient so that the risk of iatrogenic lesion of the internal mammary artery should be minimal. LEVEL OF EVIDENCE: Therapeutic/care management study, level IV.

Increased intraoperative epidural pressure in lumbar spinal stenosis patients with a positive nerve root sedimentation sign.

PURPOSE: The sedimentation sign (SedSign) has been shown to discriminate well between selected patients with and without lumbar spinal stenosis (LSS). The purpose of this study was to compare the pressure values associated with LSS versus non-LSS and discuss whether a positive SedSign may be related to increased epidural pressure at the level of the stenosis. METHODS: We measured the intraoperative epidural pressure in five patients without LSS and a negative SedSign, and in five patients with LSS and a positive SedSign using a Codman(™) catheter in prone position under radioscopy. RESULTS: Patients with a negative SedSign had a median epidural pressure of 9 mmHg independent of the measurement location. Breath and pulse-synchronous waves accounted for 1-3 mmHg. In patients with monosegmental LSS and a positive SedSign, the epidural pressure above and below the stenosis was similar (median 8-9 mmHg). At the level of the stenosis the median epidural pressure was 22 mmHg. A breath and pulse-synchronous wave was present cranial to the stenosis, but absent below. These findings were independent of the cross-sectional area of the spinal canal at the level of the stenosis. CONCLUSIONS: Patients with LSS have an increased epidural pressure at the level of the stenosis and altered pressure wave characteristics below. We argue that the absence of sedimentation of lumbar nerve roots to the dorsal part of the dural sac in supine position may be due to tethering of affected nerve roots at the level of the stenosis.

Vagal sensory evoked potentials disappear under the neuromuscular block - an experimental study.

BACKGROUND: Transcutaneous vagal nerve stimulation is a promising treatment modality in patients suffering mood disorders and chronic pain, however, the mechanisms are still to be elucidated. A recently developed technique of EEG responses to electrical stimulation of the inner side of the tragus suggests that these responses are far field potentials, generated in the vagal system - Vagal Sensory Evoked Potentials (VSEP). OBJECTIVE: To reproduce the VSEP technique free from myogenic artifacts. METHODS: Fourteen ASA I-II patients scheduled for elective surgery in standardized Total Intravenous Anesthesia (TIVA) were enrolled. Transcutaneous electrical stimulation was applied to the inner side of the right tragus. Averaged EEG responses were recorded from the electrode positions C4-F4 and T4-O2 before and after induction of TIVA, during the maximal effect of the non-depolarizing muscle relaxing agent, cis-atracurium (C-AR) and after recovery from C-AR under TIVA. RESULTS: Typical response curves with P1, N1 and P2 peaks could be reproduced in all patients before and after anesthesia induction. The response curves disappeared during the C-AR action and re-appeared after recovery from C-AR under TIVA. CONCLUSION: The disappearance of the scalp responses to electrical tragus stimulation under the neuromuscular block suggests a muscular origin of these potentials.

Light rhythm and diet differently influence facets of the metabolic syndrome in WOKW rats.

It has previously been shown that high-calorie diet alters the function of the mammalian circadian clock and that obesity has an influence on circadian organization of hormone secretion. That prompted us to test whether inbred Wistar Ottawa Karlsburg W (RT1(u)) (WOKW) rats developing facets of the metabolic syndrome show changes in their metabolic profiles under different feeding conditions (high-fat, high-sugar versus control diet) and under two different 12 h:12 h light-dark (LD) cycles. At the age of four weeks, these rats were divided into four groups. Groups 1 and 2 were kept under initial LD cycle (lights on at 05:00 h). Group 1 was fed with a normal rat diet while group 2 received a high-fat, high-sugar diet from 10 up to the age of 21 weeks. Groups 3 and 4 were kept under a shifted LD cycle (lights on at 11:00 h). Group 3 was given a normal diet while group 4 received a high-fat, high-sugar diet from an age like groups 1 and 2. Several metabolic traits were studied during the observation period of 21 weeks. The blood samples were obtained 2 h before lights off. Body weight gain (P < 0.001), leptin (P < 0.001), triglycerides (P < 0.001) and cholesterol (P < 0.05) were significantly reduced in group 4 versus group 2, but comparable between control groups (1 versus 3). The insulin concentrations were reduced in groups 3 and 4 versus groups 1 and 2 without effect of diet. In conclusion, the results provide evidence that light conditions influence diet induced changes in phenotypic traits like body weight gain, lipids as well as hormone levels (insulin and leptin) in WOKW rats.

Nail projectiles propelled by a mason's lacing cord: an experimental approach.

The recent clinical observation of two unintentional penetrating ocular and cerebral injuries due to 90-mm construction nails gave occasion to an experimental study to check the alleged trauma mechanism for plausibility. Both casualties reported that they had attached a mason's lacing cord to the masonry using a nail as anchoring when suddenly the nail was yanked from its moorings and propelled like a missile by the overstretched lacing cord. As to the best of the authors' knowledge, this mechanism of injury has not yet been reported in any of the literature; it was the aim to find an experimental approach to review the plausibility of the alleged sequence of events leading to the accidents. The tensile strength at break and strain at break of different mason's lacing cords (diameter of 1 and 2 mm) were measured according to DIN EN ISO 2062 by using a tensile testing machine. Based on the maximum spring energy of the lacing cords, which was determined 174.9 J for the 1-mm cord (length 10 m) and 747.4 J for the 2-mm cord (length 10 m), the maximum possible velocity of the nails as projectiles was calculated to be 243.5 m/s for the 1-mm cord and 503.4 m/s for the 2-mm cord. The critical elongation a cord of a certain length has to be stretched to deliver enough kinetic energy to a 90-mm nail to surpass the threshold velocity for skin penetration, which was investigated by Sellier (1977) to be approximately 18 m/s, was also calculated. To conclude, the energy delivered by the cords is high enough to surpass the rather low threshold velocity of nails. The details of how these accidents occurred, which seemed questionable at first, can be reasonably explained by trauma biomechanics.

Gene expression profile in bone of diabetes-prone BB/OK rats fed a high-fat diet.

A high-fat diet (HFD) has been recognized as a risk factor for diseases such as dyslipidemia, atherosclerosis, obesity, and osteoporosis. However, studies analyzing gene expression after HFD in bone are rare. That prompted us to analyze the expression of selected genes in bone of 4-week-old diabetes-prone B(io)B(reeding) rats. Two breeding pairs were fed a HFD (+10 % tallow) or were fed a normal diet (ND; Ssniff R-Z) before mating and afterward during pregnancy. After the birth of progeny, parents continued to be given HFD or ND until the progeny was weaned (3 weeks). Thereafter, offspring were weaned and were fed the same food as their parents up to an age of 4 weeks. Body weight was measured at an age of 4 weeks, and subsequently 13 HFD rats and 13 ND rats were killed and the tibial bone was harvested to analyze the expression of 53 genes in bone. All rats fed HFD were significantly heavier than rats fed ND after 3 and 4 weeks. The diet also influenced the expression of genes in bone. There were significant differences in 20 out of 53 genes studied between rats fed HFD compared with rats fed ND. Four out of 20 had a lower and 17 out of 20 genes a higher expression in HFD rats, but differences in gene expression showed obvious differences between males and females. There were only two genes that were similarly different between males and females: Bmp4 and Atf4. Two genes, Foxg1 and Npy, were inversely expressed in males and females. It seems that the gene expression is differently regulated by diet during pregnancy and later in life between males and females. Nevertheless, it cannot be excluded that HFD also acts as an epigenetic factor in the development of offspring in utero.

Histomorphometric and radiographical changes after lumbar implantation of the PEEK nonfusion interspinous device in the BB.4S rat model.

STUDY DESIGN: An experimental animal study. OBJECTIVE: To investigate histomorphometric and radiographical changes in the BB.4S rat model after PEEK (polyetheretherketone) nonfusion interspinous device implantation. SUMMARY OF BACKGROUND DATA: Clinical effectiveness of the PEEK nonfusion spine implant Wallis (Abbott, Bordeaux, France; now Zimmer, Warsaw, IN) is well documented. However, there is a lack of evidence on the long-term effects of this implant on bone, in particular its influence on structural changes of bone elements of the lumbar spine. METHODS: Twenty-four male BB.4S rats aged 11 weeks underwent surgery for implantation of a PEEK nonfusion interspinous device or for a sham procedure in 3 groups of 8 animals each: (1) implantation at level L4-L5; (2) implantation at level L5-L6; and (3) sham surgery. Eleven weeks postoperatively osteolyses at the implant-bone interface were measured via radiograph, bone mineral density of vertebral bodies was analyzed using osteodensitometry, and bone mineral content as well as resorption of the spinous processes were examined by histomorphometry. RESULTS.: Resorption of the spinous processes at the site of the interspinous implant was found in all treated segments. There was no significant difference in either bone density of vertebral bodies or histomorphometric structure of the spinous processes between adjacent vertebral bodies, between treated and untreated segments and between groups. CONCLUSION: These findings indicate that resorption of spinous processes because of a result of implant loosening, inhibit the targeted load redistribution through the PEEK nonfusion interspinous device in the lumbar spinal segment of the rat. This leads to reduced long-term stability of the implant in the animal model. These results suggest that PEEK nonfusion interspinous devices like the Wallis implants may have time-limited effects and should only be used for specified indications.

Phenotypic and gene expression differences between DA, BN and WOKW rats.

BACKGROUND: Because inbred rat strains are widely used as laboratory models, knowledge of phenotypic and genetic variations between strains will be useful to obtain insight into the relationship between different strains. METHODS AND RESULTS: We studied phenotypic traits: of each strain--BN/K, DA/K and WOKW--10 male rats were studied for body weight and serum constituents at an age of 10 and 30 weeks. In addition, a total of 95 rats were studied for life expectancy. At an age of 30 weeks, these male rats were killed by an overdose of anesthetic (Sevofluran, Abbott), and the subcutaneous and visceral adipose tissue as well as bone tissue were removed to study the expression of 20 genes. There were significant differences in body weight, serum lipids and leptin at an age of 30 weeks between strains. Regarding life expectancy, BN rats lived longest (1072±228d). The highest gene expression was found in bone of BN rats. In adipose tissues, Nfkb1 is only expressed in subcutaneous adipocytes, and 5 genes, Col2a1, Mmp9, Tnfa, Ins1 and Cyp24a1, are not expressed in adipocytes. The ranking BN = DA>WOKW was observed in only one gene in subcutaneous (Fto) and visceral adipocytes (Col6a1). There were no significant differences in gene expression of one gene in subcutaneous adipocytes and of 3 genes in visceral adipocytes. Comparing the gene expression in visceral and subcutaneous adipocytes, only one gene showed a comparable behavior (Bmp1). CONCLUSION: From these results, it can be concluded that obvious phenotypic differences are caused by genetic differences between three rat strains, BN, DA and WOKW, as supported by gene expression studies in bone and adipose tissues. Especially BN rats can be used to study the genetic basis of long life.