Triple growth factor delivery promotes functional bone regeneration following composite musculoskeletal trauma

Successful bone healing in severe trauma depends on early revascularization to restore oxygen, nutrient, growth factor, and progenitor cell supply to the injury. Therapeutic angiogenesis strategies have therefore been investigated to promote revascularization following severe bone injuries; however, results have been inconsistent. This is the first study investigating the effects of dual angiogenic growth factors (VEGF and PDGF) with low-dose bone morphogenetic protein-2 (BMP-2; 2.5 µg) on bone healing in a clinically challenging composite bone-muscle injury model. Our hydrogel-based delivery systems demonstrated a more than 90% protein entrapment efficiency and a controlled simultaneous release of three growth factors over 28 days. Co-stimulation of microvascular fragment constructs with VEGF and PDGF promoted vascular network formation in vitro compared to VEGF or PDGF alone. In an in vivo model of segmental bone and volumetric muscle loss injury, combined VEGF (5 µg) and PDGF (7.5 µg or 15 µg) delivery with a low dose of BMP-2 significantly enhanced regeneration of vascularized bone compared to BMP-2 treatment alone. Notably, the regenerated bone mechanics reached ~60% of intact bone, a value that was previously only achieved by delivery of high-dose BMP-2 (10 µg) in this injury model. Overall, sustained delivery of VEGF, PDFG, and BMP-2 is a promising strategy to promote functional vascularized bone tissue regeneration following severe composite musculoskeletal injury. Although this study is conducted in a clinically relevant composite injury model in rats using a simultaneous release strategy, future studies are necessary to test the regenerative potential of spatiotemporally controlled delivery of triple growth factors on bone healing using large animal models. STATEMENT OF SIGNIFICANCE: Volumetric muscle loss combined with delayed union or non-union bone defect causes deleterious effects on bone regeneration even with the supplementation of bone morphogenetic protein-2 (BMP-2). In this study, the controlled delivery of dual angiogenic growth factors (vascular endothelial growth factor [VEGF] + Platelet-derived growth factor [PDGF]) increases vascular growth in vitro. Co-delivering VEGF+PDGF significantly increase the bone formation efficacy of low-dose BMP-2 and improves the mechanics of regenerated bone in a challenging composite bone-muscle injury model.

Particulated Juvenile Articular Cartilage Implantation in the Knee: A 3-Year EPIC-µCT and Histological Examination

OBJECTIVE

The goal of this report is to describe the outcome of sequential particulated cartilage allograft and autologous osteochondral transfer treatments for an osteochondral lesion of the medial femoral condyle.

METHODS

A 44-year-old woman was treated with a particulated juvenile articular cartilage allograft (DeNovo NT) for a chondral lesion of the knee. As a result of continued pain, she had 2 further surgeries, including an autologous osteochondral transfer system procedure and finally a unicondylar knee arthroplasty. At the final procedure, the areas of the allograft and autograft tissue were biopsied for histological evaluation. The quality of the residual cartilage tissue was assessed first by equilibrium partitioning of an ionic contrast agent via micro-computed tomography (EPIC-µCT), and then by hematoxylin and eosin, Safranin O staining, and polarized light microscopy.

RESULTS

Despite showing good healing at 7 months postsurgery by MRI, at 28 months post DeNovo NT tissue implantation the excised cartilage tissue was heterogeneous, with some regions of hyaline-like cartilage and some regions of fibrocartilage. The later mosaicplasty may have helped maintain hyaline-like cartilage of the DeNovo NT tissue in its vicinity.

CONCLUSION

This case report describes the cartilage repair tissue produced by DeNovo NT implantation and compares it with autologous osteochondral plug tissue.

Contrast-enhanced microCT (EPIC-μCT) ex vivo applied to the mouse and human jaw joint

OBJECTIVES

The temporomandibular joint (TMJ) is susceptive to the development of osteoarthritis (OA). More detailed knowledge of its development is essential to improve our insight into TMJ-OA. It is imperative to have a standardized reliable three-dimensional (3D) imaging method that allows for detailed assessment of both bone and cartilage in healthy and diseased joints. We aimed to determine the applicability of a contrast-enhanced microCT (µCT) technique for ex vivo research of mouse and human TMJs.

METHODS

Equilibrium partitioning of an ionic contrast agent via µCT (EPIC-µCT) was previously applied for cartilage assessment in the knee joint. The method was ex vivo, applied to the mouse TMJ and adapted for the human TMJ.

RESULTS

EPIC-µCT (30-min immersion time) was applied to mouse mandibular condyles, and 3D imaging revealed an average cartilage thickness of 110 ± 16 µm. These measurements via EPIC-µCT were similar to the histomorphometric measures (113 ± 19 µm). For human healthy OA-affected TMJ samples, the protocol was adjusted to an immersion time of 1 h. 3D imaging revealed a significant thicker cartilage layer in joints with early signs of OA compared with healthy joints (414.2 ± 122.6 and 239.7 ± 50.5 µm, respectively). A subsequent significant thinner layer was found in human joints with late signs of OA (197.4 ± 159.7 µm).

CONCLUSIONS

The EPIC-µCT technique is effective for the ex vivo assessment of 3D cartilage morphology in the mouse as well as human TMJ and allows bone-cartilage interaction research in TMJ-OA.

Effects of in vivo mechanical loading on large bone defect regeneration

Fracture healing is highly sensitive to mechanical conditions; however, the effects of mechanical loading on large bone defect regeneration have not been evaluated. In this study, we investigated the effects of functional loading on repair of critically sized segmental bone defects. About 6-mm defects were created in rat femora, and each defect received 5 µg recombinant human bone morphogenetic protein-2 (rhBMP-2), delivered in alginate hydrogel. Limbs were stabilized by either stiff fixation plates for the duration of the study or compliant plates that allowed transfer of compressive ambulatory loads beginning at week 4. Healing was assessed by digital radiography, microcomputed tomography, mechanical testing, histology, and finite element modeling. Loading significantly increased regenerate bone volume and average polar moment of inertia. The response to loading was location-dependent with the polar moment of inertia increased at the proximal end of the defect but not the distal end. As a result, torsional stiffness was 58% higher in the compliant plate group, but failure torque was not altered. In single samples assessed for histology from each group, a qualitatively greater amount of cartilage and a lesser degree of remodeling to lamellar bone occurred in the loaded group compared to the stiff plate group. Finally, principal strain histograms, calculated by FE modeling, revealed that the compliant plate samples had adapted to more efficiently distribute loads in the defects. Together, these data demonstrate that functional transfer of axial loads alters BMP-induced large bone defect repair by increasing the amount and distribution of bone formed within the defect.

Prednisolone treatment and restricted physical activity further compromise bone of mdx mice

OBJECTIVES

The purpose of this study was to determine the extent to which prednisolone treatment and restricted physical activity caused deleterious changes in inherently compromised mdx bone.

METHODS

Four week-old male mdx mice (n=36) were treated for 8-wk either with or without prednisolone (0.8-1.3 mg/kg/d) and were housed in traditional or small cages (restricted activity). Tibial bone strength, geometry, and intrinsic material properties were assessed at the mid-shaft by three-point bending and micro-computed tomography (μCT).

RESULTS

Three-point bending results showed that both prednisolone and restricted activity reduced bone strength (7%), however stiffness was only reduced in restricted-activity mice. μCT analyses showed that cortical bone area and cortical thickness were 13% smaller in restricted-activity mice, and may have accounted for their compromised bone strength. Intrinsic material properties, including volumetric bone mineral density (vBMD) and modulus of elasticity, were not impacted by either treatment, however, vBMD tended to be lower in restricted-activity mice (p=0.06).

CONCLUSIONS

These data show that prednisolone treatment and restricted physical activity independently accentuate reductions in the strength and geometry of mdx bone, but do not influence intrinsic material properties.

Injectable poly(lactic-co-glycolic) acid scaffolds with in situ pore formation for tissue engineering

Appropriate porosity is an important biomaterial design criterion for scaffolds used in tissue engineering applications as it can permit increased cell adhesion, migration, proliferation and extracellular matrix production within the scaffold at a tissue defect site. Tissue engineering scaffolds can either be injected in a minimally invasive manner or implanted through surgical procedures. Many injectable scaffolds are hydrogel-based; these materials often possess nanoscale porosity, which is suboptimal for cell migration and proliferation. Solid scaffolds with engineered micron-scale porosity are widely used, but these scaffolds are usually pre-formed and then must be implanted. Here we report on the development of a solid, injectable, biomaterial scaffold that solidifies in situ via phase inversion with microporous, interconnected architecture on the surface and within the bulk. This injectable system utilizes the biodegradable polymer poly(lactic-co-glycolic acid), a nontoxic FDA-approved solvent, and biocompatible porogens. Various scaffold formulations are examined in terms of morphology, porosity, degradation, elastic modulus, and ability to support cellular adhesion and growth. Furthermore, the ability to form a microporous architecture upon injection in vivo is verified. This technology is a promising noninvasive approach for in vivo formation of porous biodegradable scaffolds.

Quantitative assessment of articular cartilage morphology via EPIC-microCT

OBJECTIVE

The objective of the present study was to validate the ability of Equilibrium Partitioning of an Ionic Contrast agent via microcomputed tomography (EPIC-microCT) to nondestructively assess cartilage morphology in the rat model.

DESIGN

An appropriate contrast agent (Hexabrix) concentration and incubation time for equilibration were determined for reproducible segmentation of femoral articular cartilage from contrast-enhanced microCT scans. Reproducibility was evaluated by triplicate scans of six femora, and the measured articular cartilage thickness was independently compared to thickness determined from needle probe testing and histology. The validated technique was then applied to quantify age-related differences in articular cartilage morphology between 4, 8, and 16-week-old (n=5 each) male Wistar rats.

RESULTS

A 40% Hexabrix/60% phosphate buffered saline (PBS) solution with 30 min incubation was optimal for segmenting cartilage from the underlying bone tissue and other soft tissues in the rat model. High reproducibility was indicated by the low coefficient of variation (1.7-2.5%) in cartilage volume, thickness and surface area. EPIC-microCT evaluation of thickness showed a strong linear relationship and good agreement with both needle probing (r(2)=0.95, slope=0.81, P<0.01, mean difference 11+/-22 microm, n=43) and histology (r(2)=0.99, slope=0.97, P<0.01, mean difference 12+/-10 microm, n=30). Cartilage volume and thickness significantly decreased with age while surface area significantly increased.

CONCLUSION

EPIC-microCT imaging has the ability to nondestructively evaluate three-dimensional articular cartilage morphology with high precision and accuracy in a small animal model.

Computational simulations of the human magneto- and electroenterogram

Many functional pathologies of the small intestine are difficult to diagnose clinically without an invasive surgical intervention. Often such conditions are associated with a disruption of the normal electrical activity occurring within the musculature of the small intestine. The far field electrical signals on the torso surface arising from the electrical activity within the small intestine cannot be reliably measured. However, it has been shown that abnormal electrical activity in the small intestine can be distinguished by recording the magnetic fields of intestinal origin immediately outside the torso surface. We have developed an anatomically-based computational model to simulate slow wave propagation in the small intestine, the resulting cutaneous electrical field and the magnetic field outside the torso. Using both a one-dimensional and a three-dimensional model of the duodenum we investigate the degree of detail that is required to realistically simulate this far field activity. Our results indicate that some of the qualitative behavior in the far field activity can be replicated using a one-dimensional model, although there are clear situations where the greater level modeling detail is required.

The high value of high-resolution computed tomography in predicting the activity of pulmonary tuberculosis

SETTING

A 2500-bed medical centre in southern Taiwan.

OBJECTIVE

To study the clinical value of high-resolution computed tomography (HRCT) in predicting the activity of pulmonary tuberculosis (TB).

DESIGN

HRCTs were performed prospectively in 148 patients whose chest radiographs (CXRs) showed highly suspicious signs of pulmonary TB, predominantly upper lung field infiltration. The HRCT findings, interpreted independently by a pulmonologist and a radiologist, were used to predict the activity of pulmonary TB.

RESULTS

Pulmonologist-interpreted and radiologist-interpreted HRCTs showed high sensitivity (both 93%), specificity (83 vs. 88%), accuracy (86 vs. 90%), positive predictive values (76 vs. 83%) and negative predictive values (both 95%). Kappa statistic indicates good inter-reader agreement.

CONCLUSION

HRCT has a high value in predicting the activity of pulmonary TB. It is a useful tool in this regard when a patient with suspected pulmonary TB lacks microbiologic proof, when clinical condition makes invasive diagnosis impossible or when a patient has completed anti-tuberculosis treatment with no compatible unequivocal CXR.

Effects of intravenous caffeine administered to healthy males during sleep

Pharmacological challenge paradigms have been useful for elucidating the phenomenology and neurobiology of panic attacks. A drawback of the pharmacological challenge method is that individual differences in baseline arousal and outcome expectancy can lead to different subjective and physiological drug responses. One method for eliminating differences in baseline arousal and expectancy is to perform pharmacological challenges during non-rapid eye movement (non-REM) sleep. In the present study, fourteen healthy male volunteers received caffeine (5 mg/kg) and placebo (normal saline) during non-REM sleep on two successive nights, in a single-blind manner. Caffeine, compared to placebo, was associated with increased arousal, sleep disruption, and elevations in adrenocorticotropic hormone (ACTH) and cortisol. In one subject, caffeine infusion during sleep induced a panic attack. These findings indicate that caffeine leads to increased arousal and hypothalamic-pituitary-adrenal axis (HPA) axis activation in the absence of high baseline anxiety and expectancy bias. Further, they suggest that similar techniques can be employed in patient populations to elucidate the neurobiology of sleep panic attacks.

Endobronchial metastatic disease

BACKGROUND

Endobronchial metastasis (EM) is rare. Patients with EM are in advanced stages of disease and have poor prognoses. However, some patients have had long-term survival after aggressive treatment.

METHODS

We retrospectively reviewed the records of 9678 patients who had undergone bronchoscopic procedures. Forty patients were diagnosed as having EM.

RESULTS

The most common site of primary tumors was the head and neck [10 nasopharyngeal carcinomas (NPC), 2 buccal cancers, 2 glossal cancers, 2 laryngeal cancers]. Clinical manifestations included cough (50%), hemoptysis (20%), dyspnea (15%), and absence of respiratory symptoms (15%). The most common findings in chest roentgenograms (CXR) were single masses (40%). The median length of survival for all patients was 12 months (range, 6 to 18 months). The median length of survival in patients whose ages were over 70 years was 1 months and in patients less than 70 years old it was 12 months (range, 7 to 19 months) (p = 0.002). In patients whose EM extent was to the main bronchus, the median length of survival was 1 month (range, 1 to 3 months) and that in those whose EM did not extend to main bronchus was 12 months (range, 11 to 21 months) (p = 0.0004). In patients whose primary tumors were due to head and neck cancer other than NPC, the survival time was 1 month (range, 1 to 11 months), and in others it was 12 months (range, 7 to 19 months) (p = 0.0008).

CONCLUSION

Three factors contributed to a poor prognosis, including the patient's age being over 70 years, primary tumors due to head and neck cancer other than NPC, and extension of the endobronchial metastatic lesion to the main bronchus.

Effect of simulated birth trauma on the urinary continence mechanism in the rat

OBJECTIVES

To examine the effect of simulated birth injury in an animal model as part of a study on the pathogenesis of stress urinary incontinence (SUI) and the urinary continence mechanism.

METHODS

A balloon was inflated in the vaginas of rats for 4 hours to simulate prolonged labor. The effect on the continence mechanism was assessed by functional, anatomic, biochemical, and histologic examinations. The functional test consisted of placing chili powder or a clipped whisker into the rat's nostrils to induce sneezing. Anatomic measurement of the genital hiatus was performed with a caliper. Serum creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) were measured to examine the value of muscle injury in predicting incontinence. c-Fos immunostaining in the spinal cord was used as a marker of nerve injury. These data were then correlated with histopathologic examination of the urethra and pelvic floor tissues.

RESULTS

Four weeks after simulated birth injury, SUI was noted in 19 of 48 experimental rats. The genital hiatus was significantly wider in incontinent rats. The serum CPK and LDH levels were markedly elevated, but no difference was noted between the continent and incontinent rats. All experimental rats showed many c-Fos immunostaining neurons in the L6 to S1 spinal cord segments, but none was seen in control rats. Histologic study revealed a marked decrease of ganglion cells in the neural plexuses posterolateral to the vagina in experimental rats. After 4 weeks, muscle necrosis and degeneration, irregular shape and size of muscle fibers, and a change in the type I/II ratio were prominent features in the levator ani. In the urethra, we noted a significant decline in urethral wall musculature (both smooth and striated) in incontinent rats.

CONCLUSIONS

In this novel rat model, simulated birth injury resulted in SUI in a portion of the animals. Pathologic changes in the urethra, pelvic ganglia, and levator muscles seem to be the contributing factors to SUI.

Psychopathological dimensions in schizophrenia: a correlational approach to items of the SANS and SAPS

Seventy DSM-III schizophrenic patients were assessed for positive and negative symptoms using Andreasen's scales for the assessment of positive and negative symptoms (SANS and SAPS) on admission. The correlation structure of the items in the SANS and SAPS was explored in dimension and item levels by use of correlation plots through a distinct analytical method displaying the proximity matrix. The results revealed at least three major dimensions of symptoms delineated as Negative Symptoms, Disorganized Thoughts and Delusions and Hallucinations. The latter two dimensions were derived from the SAPS, while Negative Symptoms comprised most of the items in the SANS. Items in Disorganized Thoughts were more correlated to Negative Symptoms than to the other items in the SAPS. 'Loss of ego boundary' delusions and experience of auditory hallucinations appeared as two sub-clusters in the group of Delusions and Hallucinations. The relative independence of persecutory, grandiose, religious, somatic and reference delusions gives support to the concept that paranoid schizophrenia stands as a distinct clinical subtype of schizophrenia. The graphical method introduced here well expresses the information of correlation matrix and is useful for exploring inter-item or inter-cluster associations.

Bronchial foreign bodies in adults

Aspiration of foreign bodies into the bronchial tree is infrequently seen in adults. We reviewed 40 such cases during an 8-year period at Chang Gung Memorial Hospital, Kaohsiung. Only six patients had underlying conditions that contributed to the aspiration of foreign bodies. A positive history of aspiration was found in 18 patients (48%). Clinical manifestations were nonspecific. Chest roentgenograms were useful in 11 of the 40 patients. Bronchoscopic findings were classified into three groups: foreign bodies in the bronchial tree without granulation tissue, foreign bodies in the bronchial tree with marked granulation tissue and foreign bodies embedded in the granulation tissue. The diagnoses and removal of foreign bodies were successful in 37 patients (92%) using grasping forceps or biopsy forceps and in one patient using basket type grasping forceps. Complications of bronchoscopy were rare and not serious. The diagnosis of occult foreign bodies is often difficult and demands a high index of suspicion. Removal of endobronchial foreign bodies is usually possible with a flexible fiberoptic bronchoscope and has a high success rate.

Wegener's granulomatosis: a case report and literature review

Wegener's granulomatosis may present with a variety of findings and be difficult to diagnose. We report a case of 27-year-old man presenting with chronic cough and hemoptysis who was diagnosed by open lung biopsy to have Wegener's granulomatosis. Based on this case, we reviewed the clinical features, pathophysiology, diagnosis, treatment, and prognosis of Wegener's granulomatosis.

Pyopneumothorax associated with unsuspected endobronchial foreign body: a case report

Chronic foreign body aspiration may cause a variety of complications. Nonspecific clinical presentations and chest radiographic manifestations often result in misdiagnosis or delayed diagnosis. We report an unusual complication of chronic foreign body aspiration--pyopneumothorax--in a 52-year-old patient presenting with productive cough and intermittent fever for more than 3 months. Obstructive pneumonia was highly suspected from the computed tomographic scan of the chest. Flexible fiberoptic bronchoscopy demonstrated a fish bone in the bronchial tree. The bone was successfully removed by forceps. Thoracotomy was done later to ensue adequate drainage of the pyopneumothorax. We report this case for ongoing education to increase the index of suspicion.

Malignant fibrous histiocytoma of the trachea combined with thymic carcinoma--a case report

A 58-year-old woman was hospitalized in our hospital on July 9, 1988 with the chief complaint of progressive dyspnea for three months. She had been treated as bronchial asthma before she came to our hospital. During the hospitalization, bronchoscopic examination showed a lobulated mass arising from the left anterior lateral wall of the middle trachea. Chest CT scans showed two lesions: one was a nodular protruding mass in the middle trachea; the other was a soft tissue mass at the left thymic area. We performed a total resection of the tracheal tumor and partial resection of the mediastinal tumor. The pathological diagnosis was malignant fibrous histiocytoma of the trachea and squamous cell thymic carcinoma.

Intrathoracic meningocele in association with neurofibromatosis: report of a case

A case of intrathoracic meningocele associated with neurofibromatosis is reported. Computed tomography (CT) demonstrated that the paravertebral mass had a characteristic low attenuation coefficient compatible with liquid content. CT-myelography further confirmed the diagnosis. We recommend that though intrathoracic meningocele is rare, it should be kept in mind when making a differential diagnosis in cases where the patient has neurofibromatosis with a posterior mediastinal mass.

[Subcutaneous sarcoidosis--a case report]

A 35 year-old female patient suffered from several brownishred nodule-plaques over both legs and left knee for two months. General malaise and exertional dyspnea were also noted. Skin biopsy shows multiple epithelioid cell tubercles with asteroid body in multinucleated giant cell located in the deep dermis and subcutis. No fungus, mycobacterium or foreign body could be found by special stains. Chest X-ray reveals bilateral hilar lymphadenopathy. She had neither sensory impairment nor DM history. Based on the above findings, we believed that she is a victim of subcutaneous sarcoidosis.

Removable hub needle system for coaxial biopsy of small and difficult lesions

A 23-gauge needle with a removable hub for a modified coaxial biopsy technique is described. The needle is useful for biopsy of small (less than or equal to 2.5 cm) and difficult chest or abdominal lesions. After removal of the hub, coaxial insertion of an outer 19-gauge needle is performed. Biopsy specimens are obtained coaxially through the 19-gauge needle after the hubless needle is removed. This system permits precise biopsy of smaller lesions, when the tandem biopsy technique is not practical.

Percutaneous biopsy of difficult mediastinal, hilar, and pulmonary lesions by computed tomographic guidance and a modified coaxial technique

A technique for biopsy of small or inaccessible mediastinal, hilar, or pulmonary lesions with computed-tomographic (CT) guidance is described. A modified coaxial system was used in order to make multiple passes possible without multiple punctures. The size of the original puncture needle (23 gauge) provided the inherent safety associated with a fine needle. All repositioning was done using this needle and CT until the lesion was engaged. The hub of the needle was then cut, and a 19-gauge needle was inserted coaxially over the larger needle. After removal of the 23-gauge needle, multiple biopsy specimens were then obtained coaxially with a 22-gauge needle through the 19-gauge needle. One small pneumothorax and no bleeding occurred in 10 instances. Results suggest that the combined use of CT guidance and this modified coaxial system may offer an extra margin of safety for difficult cases.