Medullary-Sparing Antibiotic Cement Articulating Spacer Reduces the Rate of Mechanical Complications in Advanced Septic Hip Arthritis: A Retrospective Cohort Study

Antibiotic cement articulating spacers eradicate infection during a two-stage revision for advanced septic hip arthritis (ASHA); however, mechanical complications have been reported. We hypothesized that the rate of mechanical complications would be lower in medullary-sparing (MS) than in non-medullary-sparing (n-MS) articulating spacers. A retrospective study of ASHA using n-MS or MS spacers was conducted between 1999 and 2019. The rate of mechanical complications and reoperation and risk factors for mechanical complications were analyzed. The cohort included 71 n-MS and 36 MS spacers. All patients were followed up for 2 years. The rate of spacer dislocation was lower in MS (0%) than in n-MS spacers (14.1%; p = 0.014). The reoperation rate for mechanical complications was lower in MS (0%) than in n-MS spacers (12.7%; p = 0.019). The rate of a diaphyseal stem during reimplantation was lower in MS (0%) than in n-MS spacers (19.4%; p = 0.002). The identified risk factors for n-MS spacer dislocation were postoperative under-restored femoral head diameter ≥3 mm, femoral offset ≥3 mm, and surgical volume (≤6 resection arthroplasties per year). Both spacers controlled infection. However, MS spacers had a lower spacer dislocation and reoperation rate and avoided the diaphyseal stem during reimplantation. We recommend using MS spacers to restore native femoral head diameter and femoral offset when ASHA is treated by surgeons with lower surgical volumes.

The exosomal secretomes of mesenchymal stem cells extracted via 3D-printed lithium-doped calcium silicate scaffolds promote osteochondral regeneration

The development of surface modification techniques has brought about a major paradigm shift in the clinical applications of bone tissue regeneration. Biofabrication strategies enable the creation of scaffolds with specific microstructural environments and biological components. Lithium (Li) has been reported to exhibit anti-inflammatory, osteogenic, and chondrogenic properties by promoting several intracellular signaling pathways. Currently, research focuses on fabricating scaffolds with simultaneous dual bioactivities to enhance osteochondral regeneration. In this study, we modified the surface of calcium silicate (CS) scaffolds with Li using a simple immersion technique and evaluated their capabilities for bone regeneration. The results showed that Li ions could be easily coated onto the surfaces of CS scaffolds without affecting the microstructural properties of CS itself. Furthermore, the modifications did not affect the printing capabilities of the CS, and porous scaffolds could be fabricated via extrusion. Moreover, the presence of Li improved the surface roughness and hydrophilicity, thus leading to enhanced secretion of osteochondral-related regeneration factors, such as alkaline phosphatase (ALP), bone sialoprotein (BSP), and collagen II (Col II) proteins. Subsequent in vivo studies, including histological and micro-CT analyses, confirmed that the Li-modified CS scaffolds promoted osteochondral regeneration. The transcriptome analysis suggested that the enhanced osteochondrogenic capabilities of our scaffolds were influenced by paracrine exosomes. We hope this study will inspire further research on osteochondral regeneration.

3D-biofabricated chondrocyte-laden decellularized extracellular matrix-contained gelatin methacrylate auxetic scaffolds under cyclic tensile stimulation for cartilage regeneration

Three-dimensional (3D) hydrogel constructs can mimic features of the extracellular matrix (ECM) and have tailorable physicochemical properties to support and maintain the regeneration of articular cartilage. Various studies have shown that mechanical cues affect the cellular microenvironment and thereby influence cellular behavior. In this study, we fabricated an auxetic scaffold to investigate the effect of 3D tensile stimulation on chondrocyte behavior. Different concentrations of decellularized extracellular matrix (dECM) were mixed with fish gelatin methacrylate (FGelMa) and employed for the preparation of dECM/FGelMa auxetic bio-scaffolds using 3D biofabrication technology. We show that when human chondrocytes (HCs) were incorporated into these scaffolds, their proliferation and the expression of chondrogenesis-related markers increased with dECM content. The function of HC was influenced by cyclic tensile stimulation, as shown by increased production of the chondrogenesis-related markers, collagen II and glycosaminoglycans, with the involvement of the yes-associated protein 1 signaling pathway. The biofabricated auxetic scaffold represents an excellent platform for exploring interactions between cells and their mechanical microenvironment.

Trends and treatments of pelvic and acetabular fractures in Taiwan: facing an aging society

Pelvic-acetabular fractures lead to high mortality in elders and their association between different groups is not known. Our results indicate that older age with pelvic-acetabular fracture was significantly associated with mortality. This finding may help planning and allocating healthcare resources, risk stratification, and optimizing the treatment of pelvic fractures.

PURPOSE

Pelvic or acetabular fractures are among main outcomes of low-energy trauma such as falls, especially in older adults. They represent approximately 3-8% of all fractures and are associated with a high mortality rate ranging from 4 to 28%. This study is aimed at comparing the incidence and trends of hip fractures and pelvic-acetabular fractures in the Taiwanese general population, gender differences in adults aged over 65 years, and mortality risk between pelvic or acetabular fractures and hip fractures and surgery trends in patients with these fractures.

METHODS

A retrospective study was conducted extracting data from the National Health Insurance Research Database of patients diagnosed with hip fracture and pelvic acetabular fracture between 2000 and 2018.

RESULTS

Older age with pelvic-acetabular fracture was significantly associated with increased mortality. No significant differences were found in comorbidities between the two fracture groups. Results provide clear epidemiological evidence for trends in pelvic-acetabular fractures in Taiwan and demonstrate the need for better strategies to manage these fractures and comorbidities, particularly in older adults.

CONCLUSION

Findings of this study may aid in planning and allocating healthcare resources, risk stratification, and optimizing the treatment of pelvic fractures among older adults in Taiwan.

Clinical and Radiographic Outcomes of Inversed Restricted Kinematic Alignment Total Knee Arthroplasty by Asia Specific (Huang’s) Phenotypes, a Prospective Pilot Study

Inverse restricted kinematic alignment (irKA) was modified from restricted kinematic alignment for total knee arthroplasty (TKA). This prospective single-center study aimed to evaluate the outcomes of irKA-TKA on all knee subtypes classified by Asia specific (Huang’s) phenotypes. A total of 96 knees that underwent irKA-TKA at one hospital between January 2018 and June 2020 were included, with 15 knees classified in Type 1, nine in Type 2, 15 in Type 3, 47 in Type 4, and 10 in Type 5 by Huang’s phenotypes. Outcomes were knee alignment measures and patient-reported satisfaction evaluated by the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and traditional Chinese version of the Forgotten Joint Score-12 (FJS-12). Follow-up was one year. Type 4 knee was most significantly corrected in all angles by irKA-TKA, followed by Type 2 and 3 knees. Type 5 and 1 knee were only significantly corrected in some angles. The correlation between FJS-12 and WOMAC was good at 6 months (Pearson correlation coefficient (r) = 0.74) and moderate at 6 weeks, 3 months, and 12 months during follow-up (r = 0.37~0.47). FJS-12 and WOMAC displayed comparable hip–knee–ankle angle cut-off value (4.71° vs. 6.20°), sensitivity (70.49% vs. 67.19%), specificity (84.00% vs. 85.71%), and Youden index (54.49% vs. 52.90%) in prediction of good prognosis. In conclusion, irKA-TKA corrects knee alignment in all knee types with increasing satisfaction for one-year follow-up. Knees with presurgical varus deformity are most recommended for irKA-TKA. Both presurgical scores of the traditional Chinese version of FJS-12 and WOMAC predict the prognosis of irKA-TKA.

Clinical Outcomes of Single Versus Double Plating in Distal-Third Humeral Fractures Caused by Arm Wrestling: A Retrospective Analysis

Background and Objectives: Arm wrestling is a simple and popular activity among young people that causes distal-third humeral fractures. However, injury to the young population may cause economic loss; therefore, they need to return to work as soon as possible. Accordingly, we aimed to compare radiological and functional outcomes of distal-third humeral fractures caused by arm wrestling treated with double and single plating. Materials and Methods: Thirty-four patients with distal-third humeral fractures caused by arm wrestling were treated between January 2015 and January 2021. They were separated into double- and single-plating groups and treated using a triceps-sparing approach. Regular follow-up was performed to evaluate elbow functionality, range of motion, bone union, and complications; the American Shoulder and Elbow Surgeons score was used for functional assessment. Results: Patients treated with single plating exhibited union rate, union time, and elbow range of motion similar to those of patients treated with double plating; however, they exhibited better pain and functional outcomes (American Shoulder and Elbow Surgeons score) at 2 weeks, 1 month, and 3 months postoperatively (84.50 ± 5.01 vs. 61.70 ± 12.53 at 2 weeks, 96.20 ± 2.63 vs. 84.25 ± 14.56 at 1 month, and 100.00 vs. 94.76 ± 9.71 at 3 months, p < 0.05). The two groups exhibited no significant differences after 1 year (100.00 vs. 98.54 ± 3.99, p < 0.13). The overall complication rate was significantly higher in patients treated with double plating than in those treated with single plating (18.75% vs. 5.56%). Radial nerve palsy was observed in patients in both groups. Conclusions: In patients with distal-third humeral fractures caused by arm wrestling, single plating provides a union rate and elbow range of motion similar to those of double plating, with significantly fewer complications and lower surgical time and blood loss with improved early functional outcomes.

Three-Dimensional Printing and Fracture Mapping in Pelvic and Acetabular Fractures: A Systematic Review and Meta-Analysis

Three-dimensional printing and fracture mapping technology is gaining popularity for preoperative planning of fractures. The aim of this meta-analysis is to further understand for the effects of 3D printing and fracture mapping on intraoperative parameters, postoperative complications, and functional recovery on pelvic and acetabular fractures. The PubMed, Embase, Cochrane and Web of Science databases were systematically searched for articles according to established criteria. A total of 17 studies were included in this study, of which 3 were RCTs, with a total of 889 patients, including 458 patients treated by traditional open reduction and internal fixation methods and 431 patients treated using 3D printing strategies. It was revealed that three-dimensional printing and fracture mapping reduced intraoperative surgical duration (RoM 0.74; 95% CI; 0.66–0.83; I² = 93%), and blood loss (RoM 0.71; 95% CI; 0.63–0.81; I² = 71%). as compared to traditional surgical approaches. In addition, there was significantly lower exposure to intraoperative imaging (RoM 0.36; 95% CI; 0.17–0.76; I² = 99%), significantly lower postoperative complications (OR 0.42; 95% CI; 0.22–0.78; I² = 9%) and significantly higher excellent/good reduction (OR 1.53; 95% CI; 1.08–2.17; I² = 0%) in the three-dimensional printing and fracture mapping group. Further stratification results with only prospective studies showed similar trends. Three-dimensional printing and fracture mapping technology has potential in enhancing treatment of complex fractures by improving surgical related factors and functional outcomes and therefore could be considered as a viable tool for future clinical applications.

Posterior-Stabilized Antibiotic Cement Articulating Spacer With Endoskeleton-Reinforced Cam Reduces Rate of Post-Cam Mechanical Complications in Prosthetic Knee Infection: A Preliminary Study

BACKGROUND

Posterior-stabilized antibiotic cement articulating spacers (PS spacers) reduce spacer mechanical complications in prosthetic knee infections (PKIs); however, joint dislocation after femoral cam fracture has been reported. We hypothesized that the rate of post-cam mechanical complications is lower in PS spacers with an endoskeleton-reinforced cam.

METHOD

A retrospective study of PKIs using PS spacers with or without a Kirschner wire-reinforced cam (K-PS or nK-PS spacers, respectively) was conducted between 2015 and 2019. The rates of post-cam mechanical complications and reoperation, as well as risk factors for post or cam failure, were analyzed.

RESULTS

The cohort included 118 nK-PS and 49 K-PS spacers. All patients were followed up for 2 years. The rate of joint subluxation/dislocation after femoral cam fracture was lower in K-PS (0%) than in nK-PS spacers (17.8%; P = .002). The reoperation rate for spacer mechanical complications was lower in K-PS (0%) than in nK-PS spacers (11.9%; P = .008). The identified risk factors for femoral cam fractures were body mass index ≥25 kg/m², femoral spacer size ≤2, and surgical volume ≤12 resection arthroplasties per year.

CONCLUSION

This preliminary study highlights that K-PS spacers have a lower rate of post-cam mechanical complications than nK-PS spacers. We recommend the use of PS spacers with endoskeleton-reinforced cam when treating PKIs performed by surgeons with lower surgical volumes, especially in patients with higher body mass index and smaller femoral spacer sizes.

Arthroscopy-Assisted Reduction and Internal Fixation versus Open Reduction and Internal Fixation for Glenoid Fracture with Scapular Involvement: A Retrospective Cohort Study

Background: We investigated the superiority of arthroscopy-assisted reduction and internal fixation (ARIF) to open reduction and internal fixation (ORIF) for treating glenoid fracture with scapular involvement. Methods: We retrospectively enrolled patients with glenoid fracture who underwent ARIF or ORIF from 2010–2020. Radiographic outcomes were assessed, and clinical outcomes (active range of motion [ROM], visual analog scale [VAS], Constant, and Disabilities of the Arm, Shoulder and Hand [DASH]) were evaluated 12 months postoperatively. Results: Forty-four patients with Ideberg type II–VI glenoid fractures (ARIF: 20; ORIF: 24; follow-up 12–22 months) were included. Union was achieved in all patients. Active ROM values were comparable between the approaches. Constant and DASH scores were non-significantly better with ARIF (90.9 ± 9.2 vs. 86.6 ± 18.1 [p = 0.341] and 6.8 ± 9.4 vs. 9.3 ± 21.3 [p = 0.626], respectively). However, VAS scores were significantly lower with ARIF (1.5 ± 0.6 vs. 2.7 ± 1.4, p = 0.001). Associated intra-articular lesions (articular depressions [80%], superior labral anterior-posterior tear [20%], labral tears [30%]) were found in most ARIF cases and were repaired during ARIF. Conclusions: For glenoid fracture with scapular involvement, ARIF allows accurate diagnosis of fracture pattern and the management of associated intra-articular lesions, with better pain control outcomes than ORIF. Thus, arthroscopy-assistant surgery should be considered in patient with glenoid fracture.

Cruciate-Retaining vs Posterior-Stabilized Antibiotic Cement Articulating Spacers for Two-Stage Revision of Prosthetic Knee Infection: A Retrospective Cohort Study

BACKGROUND

Antibiotic cement articulating spacers are recommended during 2-stage revision for prosthetic knee infection because of increased range of motion (ROM) and improved function; however, spacer mechanical complications have been reported. We aimed to determine the association between different constraints of articulating spacers and the rate of complications and infection eradication, functional outcomes, and ROM.

METHODS

A retrospective study of prosthetic knee infection using cruciate-retaining (CR) or posterior-stabilized (PS) spacers was conducted between 2011 and 2018. The rate of spacer mechanical complications, infection eradication after reimplantation and reoperation, Hospital of Special Surgery (HSS) knee score, and ROM during the interim stage were analyzed. All patients were regularly followed up for 2 years.

RESULTS

One hundred forty-one patients were included, with 66 CR and 75 PS spacers. Overall mechanical complication rate was lower in PS (9.3%) than in CR spacers (45.5%) (P < .001), especially in joint dislocation (1.3% vs 30.3%, respectively, P < .001). Overall reoperation rate was lower in PS (16.0%) than in CR spacers (36.4%) (P < .001), especially for mechanical complications (1.3% vs 24.2%, respectively, P < .001). HSS knee score was higher in PS (72.3) than in CR spacers (63.8) (P < .001). ROM was greater in PS (90.3°) than in CR spacers (80.6°) (P = .005), especially at maximum flexion (102.4° vs 89.6°, respectively, P = .003). Infection eradication was comparable between the spacers.

CONCLUSION

Both spacers can control infection; however, PS spacers had a lower rate of mechanical complications and reoperation, better HSS knee scores, and greater ROM than CR spacers.

Digital Light Processing Bioprinted Human Chondrocyte-Laden Poly (γ-Glutamic Acid)/Hyaluronic Acid Bio-Ink towards Cartilage Tissue Engineering

Cartilage injury is the main cause of disability in the United States, and it has been projected that cartilage injury caused by osteoarthritis will affect 30% of the entire United States population by the year 2030. In this study, we modified hyaluronic acid (HA) with γ-poly(glutamic) acid (γ-PGA), both of which are common biomaterials used in cartilage engineering, in an attempt to evaluate them for their potential in promoting cartilage regeneration. As seen from the results, γ-PGA-GMA and HA, with glycidyl methacrylate (GMA) as the photo-crosslinker, could be successfully fabricated while retaining the structural characteristics of γ-PGA and HA. In addition, the storage moduli and loss moduli of the hydrogels were consistent throughout the curing durations. However, it was noted that the modification enhanced the mechanical properties, the swelling equilibrium rate, and cellular proliferation, and significantly improved secretion of cartilage regeneration-related proteins such as glycosaminoglycan (GAG) and type II collagen (Col II). The cartilage tissue proof with Alcian blue further demonstrated that the modification of γ-PGA with HA exhibited suitability for cartilage tissue regeneration and displayed potential for future cartilage tissue engineering applications. This study built on the previous works involving HA and further showed that there are unlimited ways to modify various biomaterials in order to further bring cartilage tissue engineering to the next level.

Isolated Middle-Third Clavicle Fracture Causing Horner's Syndrome: A Case Report and Literature Review

The pathophysiology of Horner's syndrome arises due to compression or destruction of the oculosympathetic nerve pathway. Traumatic Horner's syndrome may indicate lethal neurovascular injury, such as brain stem lesion, cervical spine injury, or carotid artery dissection. The middle-third is the most common type of clavicle fracture. However, the association of the isolated middle-third clavicle fracture and Horner's syndrome is rare. We report the case of a 47 year-old woman who presented to our emergency department with acute trauma. Severe tenderness and limited mobility were observed in her left shoulder. On radiographic examination, a middle-third clavicle fracture was diagnosed. Ptosis and myosis were also noticed on further examination, and she was subsequently diagnosed with Horner's syndrome. A survey of the brain, cervical spine, carotid artery, and lung revealed no pathological findings. Surgery for the clavicle fracture was performed 2 days after the accident. The patient recovered from Horner's syndrome gradually over the 2 months following the surgery, and the syndrome completely resolved by the third month. To the best of our knowledge, this is the first report of traumatic Horner's syndrome caused by an isolated middle-third clavicle fracture. The improved outcome may be attributed to the surgical intervention for middle-third clavicle fracture, which may help release ganglion or neuronal compression.

Preliminary clinical and radiographic outcomes of proximal humeral fractures: comparison of ALPS and PHILOS plating in Asian patients in Taiwan

Background

Up to 20% of proximal humeral fractures need to be treated operatively. However, numerus complications were reported by using fixed angled locking plates. The ALPS Proximal Humerus Plating System is a new design implant with novel design features.

The aim of this study was to compare the preliminary clinical outcomes and complications of proximal humeral fractures treated with either ALPS or the proximal humeral internal locking system (PHILOS) in Asian patients in Taiwan.

Methods

Between January 2016 and December 2018, 66 patients with displaced proximal humeral fractures were analyzed retrospectively, of whom 31 underwent ALPS implant treatment and 35 underwent PHILOS implant treatment. Intraoperative blood loss and operation time, postoperative Constant-Murley Shoulder Outcome (Constant-Murley) score, and complications variables were recorded for the comparison. All cases were regularly followed up for at least 1 year.

Results

The mean follow-up period was 400.8 days (range, 367–446 days). Union was achieved in 98.5% of patients (65/66). The ALPS group yielded similar radiologic and clinical outcomes to the PHILOS plating group for treating displaced proximal humeral fractures, including operation time, intraoperative blood loss, the Constant-Murley score, and varus malunion (P > 0.05, respectively). However, the incidence of total postoperative complications in the ALPS group was significantly lower than in the PHILOS group (P < 0.05). There was a trend of a lower complication rate of screws/pegs protrusion, avascular necrosis, subacromial impingement, postoperative infection, and reoperation in the ALPS group, although it was not statistically significant (P > 0.05, respectively).

Conclusion

The ALPS group yielded similar radiologic and clinical outcomes to the PHILOS plating group for displaced proximal humeral fractures, but the ALPS group had a significantly lower total rate of complications. Therefore, ALPS may be a better option for treating proximal humeral fractures. Further larger clinical studies are needed to confirm the findings presented here.

Trial registration

Retrospective study

Establishment of feline in-house reference intervals for hematologic and biochemical parameters and potential age-related differences

Reference intervals (RIs) are one of the essential elements in the procedure of disease diagnosis. This is especially true for feline species in which RI is less available than in canine species. RIs are affected by biological, geographical and instrumental factors, yet published RIs with incomplete background are popularly used. Inappropriate interpretations of RIs may affect classification of disease and subsequent treatment. In this study, we demonstrated the step-by-step establishment of feline RIs following the American Society for Veterinary Clinical Pathology (ASVCP) reference interval guideline. A total of 51 parameters were examined, including 20 hematology and 31 biochemistry parameters, and the results were compared to one local RI and two foreign RIs. Overall, about 29% (10/35) of tested parameters were different form local RIs and 60% (30/50) were different from the two foreign RIs, highlighting geographical variations. A higher upper reference limit (URL) in red blood cell count (RBC), hematocrit (Hct), Hemoglobin (Hgb), albumin, creatinine and lower URL in potassium and white blood cell count (WBC) were identified, which may impact the interpretation. In addition, statistical analysis of age and gender were factored separately and indicated that 10 parameters were significantly higher in the adult group. For the impact of gender, percentage of basophil and total iron-binding capacity (TIBC) were lower in female and male cats, respectively. In conclusion, we have demonstrated that it is desirable to establish in-house RIs or RIs of local sources. An age specific RI for the geriatric feline population is advisable for better diagnosis and monitoring the disease.

The novel application of cordycepin in maintaining stem cell pluripotency and increasing iPS cell generation efficiency

Maintaining the pluripotency of either embryonic stem (ES) cells or induced pluripotent stem (iPS) cells is a fundamental part of stem cell research. In this study, we reported that cordycepin promoted the expression of pluripotency markers in ES and iPS cells. ES cells treated with cordycepin demonstrated their potential for generating embryoid bodies and differentiating into all three germ layers. The expression levels of phospho-Jak2, phospho-Stat3, integrin αV, and integrin β5 were increased after cordycepin treatment. Furthermore, the protein expression levels of IL-6 family proteins (IL-6, IL-11, LIF, oncostatin M (OSM), ciliary neurotrophic factor (CNTF)), and epidermal growth factor (EGF) were also upregulated after cordycepin treatment, but were restored after co-treatment with a Jak2 inhibitor (AG490). The gene expression levels of Yamanaka factors were upregulated in mouse embryonic fibroblasts (MEFs) after cordycepin treatment. Moreover, the generation efficiencies of iPS cells were elevated after cordycepin treatment. We found that iPS cells generated after cordycepin treatment, not only expressed pluripotency markers, but also showed the ability of differentiating into neuron stem/progenitor cells. Taken together, we demonstrated that cordycepin maintained the pluripotency of stem cells via regulation of extracellular matrix (ECM) and Jak2/Stat3 signaling pathway and improved the generation efficiency of iPSCs.

Fractures as a suicidal behavior risk factor: A nationwide population-based cohort study

This study aimed to evaluate the association between fracture history and sequential risk of suicidal behavior.A total of 82,804 patients with fractures and 82,804 control subjects without fractures were matched. The influence of fractures on the risk of suicidal behavior-related hospital visit was analyzed using a Cox proportional hazards model.The overall adjusted hazard ratio (aHR) of suicidal behavior-related hospital visit was 2.21 in fracture cohort. The aHR declined from 2.90 at the 1-year follow-up to 2.00 after 5 years or more. In fracture patients, the risk of suicidal behavior-related hospital visit was higher at age <35 years, with comorbidities of stroke and sleep disorder. Patients with multiple fractures had a 1.69-fold risk.Fractures are an independent risk factor for suicidal behavior. Individuals aged younger than 35 years, with comorbidities of stroke and sleep disorder, and those who have suffered multiple fractures have elevated risk of suicidal behavior among subjects in the fracture group. Furthermore, this increased risk remained even after 5 years had passed since the fracture incident.

Increase of Meningitis Risk in Stroke Patients in Taiwan

Background and purpose

The blood–brain barrier (BBB) not only provides a physical obstruction but also recruits and activates neutrophils in cases of infection. Hemorrhagic or ischemic stroke reportedly induces the disruption of the BBB. However, few studies have reported a correlation between the incidence of meningitis in patients with a history of stroke. This study tested the hypothesis that patients with a history of stroke may be more vulnerable to meningitis.

Methods

Stroke and age-matched comparison (n = 29,436 and 87,951, respectively) cohorts were recruited from the Taiwan National Health Insurance database (2000–2011). Correlations between the two cohorts were evaluated by Cox proportional hazard regression model, Kaplan–Meier curve, and log-rank tests.

Results

The incidence of meningitis was higher in the stroke cohort compared to that in the comparison cohort [hazard ratio (HR), 2.89; 95% confidence interval (CI), 2.23–3.74, p < 0.001]. After adjusting for age, sex, and comorbidities, the estimated HR in the stroke cohort was 2.55-fold higher than that in the comparison cohort (CI, 1.94–3.37; p < 0.001). Notably, patients who had experienced hemorrhagic stroke had a higher incidence rate of meningitis than those with a history of ischemic stroke, except for patients older than 75 years (incidence rates in hemorrhagic/ischemic stroke patients, 3.14/1.48 in patients younger than 45 years, 1.52/0.41 in 45- to 64-year group, 1.15/0.90 in 65- to 74-year group, 0.74/0.93 in patients older than 75 years). Moreover, stroke patients who had undergone head surgery had the highest meningitis risk (adjusted HR, 8.66; 95% CI, 5.55–13.5; p < 0.001) followed by stroke patients who had not undergone head surgery (adjusted HR, 2.11; 95% CI, 1.57–2.82; p < 0.001).

Conclusion

Our results indicated that stroke patients have higher risks of meningitis. Compromised BBB integrity in stroke patients may lead to increased vulnerability to infectious pathogens. In summary, our study provided new evidence of the clinical relationship between stroke and meningitis, and our findings suggest the need for precautions to prevent meningitis in stroke patients.

Disorder-related risk factors for revision total hip arthroplasty after hip hemiarthroplasty in displaced femoral neck fracture patients: a nationwide population-based cohort study

Background

The choice of primary hip hemiarthroplasty or total hip arthroplasty for displaced femoral neck fracture is still controversial. Revision hip arthroplasty not only increases risk and cost but also could result in worse outcome. Determining the risk factors for revision can help inform medical decision-making and aid in risk stratification of publicly reported outcomes. Therefore, we conducted a nationwide population-based study to identify the disease-related risk factors and construct a risk score nomogram to predict revision surgery.

Methods

Records of all 68,030 femoral neck fracture patients receiving partial hemiarthroplasty (HA) in 2000–2010, with no total hip arthroplasty (THA) or revision HA history, were collected from the National Health Insurance Research Database. Cox proportional hazard regression was used to estimate the risk of revision hip replacement (RHA). The score of each risk factor was the quotient of the regression coefficient of the variable by the regression coefficient for a 10-year increase in age. The predictive accuracy was tested using the area under the receiver operating characteristic curve (AUROC).

Results

The revision risk for hemiarthroplasty increased in male, those with schizophrenia and end-stage renal disease patients had 1.58-, 1.88-, and 1.74-fold revision HA risk (95 % confidence interval (CI) = 1.40–1.78, 1.26–2.79, and 1.29–2.34, respectively). In a predictive model, the cumulative risk score ranged from 0 to 13 with a 5.08 to 91.82 % 10-year predicted RHA risk. The percentage of AUROC for 10-year RHA risk in nomogram was 61.9 (95 % CI = 60.0–63.4).

Conclusions

Males, schizophrenia and end-stage renal disease patients have higher risk of revision surgery after hemiarthroplasty for femoral neck fracture.

Distances between bony landmarks and adjacent nerves: anatomical factors that may influence retractor placement in total hip replacement surgery

Background

Retractor placement is a leading cause of intraoperative nerve injury during total hip replacement (THR) surgery. The sciatic nerve, femoral nerve, and superior gluteal nerve are most commonly affected. This study aimed to identify the distances from bony landmarks in the hip to the adjacent nerves on magnetic resonance imaging (MRI) and the associations between anatomical factors and these distances that would guide the placement of retractors during THR surgery, in order to minimize the risk of nerve injury.

Methods

We reviewed hip MRIs of 263 adults and recorded the distances from (1) the anterior acetabular rim to the femoral nerve; (2) the superior acetabular rim to the superior gluteal nerve; (3) the posterior acetabular rim to the sciatic nerve; and (4) the greater trochanter to the sciatic nerve. The effects of anatomical factors (i.e., gender, age, body height, body mass index (BMI), pelvic width, and acetabular version and morphology) on these distances were analyzed.

Results

Distances from bony landmarks to adjacent nerves (in cm) were 2.06 ± 0.44, 2.23 ± 0.28, 1.94 ± 0.81, and 4.83 ± 0.26 for the anterior acetabular rim, superior acetabular rim, posterior acetabular rim, and greater trochanter, respectively, and were shorter in women than in men (P < 0.001). Multivariate analysis identified body height as the most influential factor (P < 0.001). Linear regression demonstrated a strong positive linear correlation between body height and these distances (Pearson’s r = 0.808, 0.823, 0.818, and 0.792, respectively (P < 0.001)).

Conclusions

The distances from bony landmarks to adjacent nerves provide useful information for placing retractors without causing nerve injury during THR surgery. Shorter patients will have shorter distances from bony landmarks to adjacent nerves, prompting more careful placement of retractors.

Controllable disorder in a hybrid nanoelectronic system: realization of a superconducting diode

We have studied a hybrid nanoelectronic system which consists of an AlGaAs/GaAs two-dimensional electron gas (2DEG) in close proximity (~70 nm) to an Al superconducting nanofilm. By tuning the current through the Al film, we can change the conductance of the 2DEG and furthermore vary the effective disorder in the Al superconducting film in a controllable way. When a high current is injected into the film, screening which couples the Al film and the 2DEG results in a collapse of anti-symmetric behavior in the current-voltage characteristics, V(I) ~ -V(-I), which holds true in a conventional superconductor. Our results may open a new avenue of experimentally realizing a superconducting diode.

Discontinuation of alendronate and administration of bone-forming agents after surgical nailing may promote union of atypical femoral fractures in patients on long-term alendronate therapy

BACKGROUND

Long-term alendronate therapy may lead to atypical femoral fractures in a very few patients. However, the management protocol to optimize fracture healing remains undetermined. The purpose of this study was to describe the time to union of atypical femoral fractures after surgical nailing in patients on long-term alendronate therapy, with continuation of alendronate or discontinuation of alendronate, and administration of bone-forming agents.

FINDINGS

From January 2004 to December 2011, the records of patients at our institution on long-term alendronate therapy for more than 36 months and sustaining atypical femoral fractures that had undergone surgical nailing, with continuation of alendronate or discontinuation of alendronate and administration of bone-forming agents were reviewed.During the 8-year study period, we treated 10 atypical femoral fractures with surgical nailing in 7 consecutive osteopenic or osteoporotic patients on long-term alendronate therapy for more than 36 months. There were no post-operative complications or needs for revision surgery. All fractures achieved union during follow-up. Mean union time was 23.5 months (range, 18-31 months) for 6 fractures with continuation of alendronate after surgery, and 4.5 months (range, 4-5 months) for 4 fractures with discontinuation of alendronate and administration of bone-forming agents after surgery.

CONCLUSIONS

Discontinuation of alendronate and administration of bone-forming agents after surgical nailing may promote union of atypical femoral fractures in patients on long-term alendronate therapy.

Tuberculosis of the breast: 10 years' experience in one institution

SETTING

Breast tuberculosis (TB) is rare even in endemic areas. Its presentation is variable and non-specific, and its diagnosis is therefore usually delayed.

DESIGN

We recruited breast TB cases between 1998 and June 2009 at Kaohsiung Medical Center in southern Taiwan. We retrospectively reviewed the clinical features, diagnosis and management of breast TB.

RESULTS

A total of 26 patients with breast TB (25 females) were included in this study. The most common presentation was breast tumour, followed by breast abscess and painful sensation. Patients received partial mastectomy or incision and drainage. The pathological examination revealed granulomatous inflammation, acute and chronic inflammation or both. Polymerase chain reaction has very low sensitivity in diagnosing breast TB. The interval between initial presentation and definite treatment was an average of 54.5 days. All patients received anti-tuberculosis chemotherapy, with excellent response.

CONCLUSION

The presentation of breast TB is variable and diagnosis is usually delayed. The disease can be diagnosed through pathological tests and a high suspicion by experienced physicians. The definite treatment is adequate anti-tuberculosis chemotherapy after surgical excision or drainage.

Rapidly fatal bacteremic pneumonia caused by Klebsiella pneumoniae with K1 hypermucoviscosity phenotype in a previously healthy young man receiving levofloxacin treatment

Fatal bacteremic Klebsiella pneumoniae pneumonia is commonly encountered in alcoholic and diabetic patients. This report describes a previously healthy young man with rapidly fatal bacteremic pneumonia caused by K. pneumoniae serotype K1, complicated by septic shock and multiple organ dysfunction.

Serovar distribution and antimicrobial susceptibility of swine Salmonella isolates from clinically ill pigs in diagnostic submissions from Indiana in the United States

AIMS

To determine serovar distribution and levels of antimicrobial susceptibility of Salmonella isolated from clinically ill pigs in diagnostic submissions.

METHODS AND RESULTS

A total of 197 Salmonella isolates were obtained by the Indiana Animal Disease Diagnostic Laboratory from 2003 to 2005. Minimal inhibitory concentrations (MICs) were determined using the standard microbroth dilution method. The top four serovars identified were Salm. enterica serovar Typhimurium variant Copenhagen, Salm. Derby, Salm. Choleraesuis var. Kunzendorf and Salm. Typhimurium. All isolates were susceptible to the fluoroquinolones tested except that eight isolates were intermediate to difloxacin. The isolates showed a low prevalence of resistance to trimethoprim/sulphadiazine (Sxt), gentamicin (G), ceftiofur (Cf) and cephalothin (Cp) with low MIC(50) value of <or=0.5, 0.5, 1 and 4 microg ml(-1), respectively. They showed a high prevalence of resistance to tetracycline (T; 83.8%), and a moderate prevalence to ampicillin (55.8%), spectinomycin (42.6%), ticarcillin (41.6%) and florfenicol (41.1%). There were more isolates of Salm. Typhimurium, including var. Copenhagen and Salm. Agona, that possessed multiple antimicrobial resistance to amoxicillin/clavulanic acid, ampicillin, ceftiofur and cephalothin (AxApCfCp) than the other serovars.

CONCLUSIONS

The swine Salmonella isolates were susceptible to the fluoroquinolones, Sxt, G, Cf and Cp, but resistant to T.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings provided useful information regarding antimicrobial susceptibility and resistance in dealing with clinical salmonellosis in pig herds.

Metritis, valvular endocarditis, and septicemia by Actinobacillus equuli in a gilt in the United States

A 1-year-old pregnant Yorkshire gilt was found dead with no previous clinical signs. Gross findings included metritis, splenomegaly, and valvular endocarditis. Bacterial endocarditis (in the mitral and tricuspid valves) and metritis with dissemination to multiple organs was diagnosed by using histologic examination. Gram-negative coccobacillary organisms present in the valvular lesions were characterized as Actinobacillus equuli by using polymerase chain reaction examination on formalin-fixed, paraffin-embedded tissues (FFPE). A. equuli is rarely reported as a cause of septicemia in pigs in Europe. A. equuli in pigs in the United States has been reported only twice and not, to our knowledge, in the last 30 years. This is the first time that molecular techniques have been used to characterize this organism in FFPE porcine tissues.

Induction of acute lymphocytic leukemia differentiation by maintenance therapy

Despite extensive study in many malignancies, maintenance therapy has clinically benefited only two diseases: acute lymphocytic leukemia (ALL) and acute promyelocytic leukemia (APL). ALL maintenance therapy utilizes low-dose 6-mercaptopurine (6MP) and methotrexate (MTX), while maintenance in APL primarily consists of all-trans-retinoic acid (ATRA). 6MP and MTX as used in ALL are also now usually added to maintenance ATRA for APL, based on data suggesting an improved disease-free survival. Although the mechanism of action of MTX and 6MP as maintenance is unknown, low-dose cytotoxic agents are potent inducers of differentiation in vitro. Thus, we studied whether maintenance therapy in ALL, like ATRA in APL, may be inducing terminal differentiation of ALL progenitors. The APL cell line NB4, the ALL cell lines REH and RS4;11, and patients' ALL blasts were incubated with ATRA, 6MP, and MTX in vitro. All three drugs inhibited the clonogenic growth of the APL and ALL cell lines without inducing immediate apoptosis, but associated with induction of phenotypic differentiation. The three drugs similarly upregulated lymphoid antigen expression, while decreasing CD34 expression, on patients' ALL blasts. These data suggest that induction of leukemia progenitor differentiation plays an important role in the mechanism of action of maintenance therapy in ALL.

Infectious bursal disease virus recovery from Vero cells transfected with RNA transcripts is enhanced by expression of the structural proteins in trans

Positive sense RNA transcripts of infectious bursal disease (IBD) virus genome segments A and B have previously been shown to be infectious. In this study we demonstrate that recovery of IBD virus from the transfection of Vero cells with positive sense RNA transcripts of genome segments A and B was enhanced by expression of the viral structural proteins VP2 with VP3 or by expression of viral polyprotein VP243 from DNA plasmids in trans. Expression of individual viral proteins VP2, VP3, or VP4 alone from DNA plasmids did not enhance IBD virus recovery. Earliest virus recovery from transfection of positive sense RNA transcripts of genomic segments A and B was at 36 h and mean titers were 10(1.8) pfu/ml. IBD virus was recovered 6 hours after transfection in cells concurrently expressing either VP2 with VP3 or VP243 and mean titers were 10(8.5) pfu/ml or 10(9.2) pfu/ml, respectively. Likewise, expression of the viral polyprotein from DNA plasmid increased the permissiveness of Vero cells for infection with non-culture adapted IBD virus. The titer of recovered non-culture adapted virus from 10(3.3) pfu/ml to 10(10.3) pfu/ml with expression of the viral polyprotein. This report is the first to describe a reverse genetics model for IBD virus with high efficiency of virus recovery for non-culture adapted strains.

Mycobacterium avium subsp. paratuberculosis fibronectin attachment protein facilitates M-cell targeting and invasion through a fibronectin bridge with host integrins

Efficient attachment and ingestion of Mycobacterium avium subsp. paratuberculosis by cultured epithelial cells requires the expression of a fibronectin (FN) attachment protein homologue (FAP-P) which mediates FN binding by M. avium subsp. paratuberculosis. Invasion of Peyer's patches by M. avium subsp. paratuberculosis occurs through M cells, which, unlike other intestinal epithelial cells, express integrins on their luminal faces. We sought to determine if the interaction between FAP-P of M. avium subsp. paratuberculosis and soluble FN enabled targeting and invasion of M cells by M. avium subsp. paratuberculosis in vivo via these surface integrins. Wild-type and antisense FAP-P mutant M. avium subsp. paratuberculosis strains were injected alone or coinjected with blocking peptides or antibodies into murine gut loops, and immunofluorescence microscopy was performed to assess targeting and invasion of M cells by M. avium subsp. paratuberculosis. Nonopsonized M. avium subsp. paratuberculosis preferentially invaded M cells in murine gut loops. M-cell invasion was enhanced 2.6-fold when M. avium subsp. paratuberculosis was pretreated with FN. Invasion of M cells by the antisense FAP-P mutant of M. avium subsp. paratuberculosis was reduced by 77 to 90% relative to that observed for the control strains. Peptides corresponding to the RGD and synergy site integrin recognition regions of FN blocked M. avium subsp. paratuberculosis invasion of M cells by 75 and 45%, respectively, whereas the connecting segment 1 peptide was noninhibitory. Antibodies against the alpha5, alphaV, beta1, and beta3 integrin subunits inhibited M-cell invasion by 52 to 73%. The results indicate that targeting and invasion of M cells by M. avium subsp. paratuberculosis in vivo is mediated primarily by the formation of an FN bridge formed between FAP-P of M. avium subsp. paratuberculosis and integrins on M cells.

Infectious bursal disease virus polyprotein expression arrests growth and mitogenic stimulation of B lymphocytes

Infectious bursal disease virus (IBDV) causes lymphocytolysis and immunosuppression in infected poultry. The IBDV genome encodes a polyprotein VP243 that is post-translationally cleaved by the VP4 protease into the two structural proteins pVP2 and VP3. The objective of the present study was to determine if IBDV polyprotein induced suppression of bursal B lymphocyte growth and their capacity for proliferation. Bursal B cells were examined both for chickens infected with IBDV and for chickens orally inoculated with a DNA construct expressing IBDV VP243 polyprotein. Bursae were collected at 0, 12, 24 and 48 hours after inoculation. Proliferation of bursal B cells (purified AvBu1(+) cells) in response to concanavalin A mitogenic stimulation was significantly suppressed by infection at 1 day old with either the classical STC or variant E strains of IBDV. Oral administration of DNA constructs expressing the IBDV VP243 polyprotein from either the classical STC or variant E strains in the pCR3.1 vector resulted in persistent, moderate levels of construct in the bursa until at least 48 hours after inoculation. The VP243 DNA construct similarly induced suppression of proliferation for bursal lymphocytes independently of the virus infection. Expression of VP243 polyprotein in transiently transfected DT40 B lymphocyte culture also suppressed cell growth and proliferative responses to mitogen stimulation. Polyprotein expression did not affect cell viability and suppression of proliferation probably occurred by means of cell cycle arrest. The expression of the mature viral proteins VP2, VP4 or VP3 did not change the rate of cell proliferation or response of B cell cultures to mitogen. The results suggested that IBDV polyprotein is a mediator of immunosuppression.

Existence of gene 5 indicates close genomic relationship of Turkey coronavirus to infectious bronchitis virus

A segment of genomic RNA extending from the 3'-end of the membrane (M) protein gene to the 5'-end of the nucleocapsid (N) protein gene of Turkey coronavirus (TCV) was amplified by reverse transcription-polymerase chain reaction (RT-PCR). The primers were derived from the corresponding sequences of Infectious bronchitis virus (IBV). The PCR products were cloned and sequenced and their nucleic acid structure and similarity to the published sequences of IBV were analyzed. Gene 5 containing two overlapping open reading frames (ORFs), 5a and 5b, was localized between M and N genes of TCV. The overall nucleotide sequences of the amplified regions from TCV isolates shared 88.4% to 91.8% similarity to the corresponding region of IBV strains. The consensus transcription-associated sequence of IBV, CTTAACAA, was highly conserved in the TCV genome with regard to nucleotide sequence and location in terms of the initiation codons of the genes 5 and N. The similarities between the predicted amino acid sequences of ORFs 5a and 5b of TCV isolates and the homologous genes of IBV strains were 85.4% to 94.0%. The results indicate the existence of gene 5 in the genome of TCV and a close relatedness of the TCV gene 5 to the IBV gene 5 in location and nucleotide sequence.

Fibronectin attachment protein is necessary for efficient attachment and invasion of epithelial cells by Mycobacterium avium subsp. paratuberculosis

Attachment and ingestion of Mycobacterium avium subsp. paratuberculosis by two epithelial cell lines were enhanced by soluble fibronectin (FN). Peptide blocking of the FN attachment protein (FAP-P) inhibited the internalization of M. avium subsp. paratuberculosis. Disruption of FAP-P expression significantly reduced attachment and ingestion of M. avium subsp. paratuberculosis by T-24 and Caco-2 cells. The results indicate that the interaction between FN and FAP-P facilitates attachment and internalization of M. avium subsp. paratuberculosis by epithelial cells.

The effect of dietary carnitine on semen traits of white Leghorn roosters

Carnitine has antioxidant properties that protect sperm membranes against toxic reactive oxygen species. Carnitine also functions to reduce the availability of lipids for peroxidation by transporting fatty acids into the mitochondria for beta-oxidation to generate adenosine triphosphate (ATP) energy. Because the effects of this supplemental amino acid on the reproductive performance of the avian breeder male are unknown, the objective of the current study was to evaluate the antioxidant role of dietary L-carnitine on semen traits and testicular histology in Leghorn breeder roosters. Two experiments were conducted in which birds were fed a control diet or one supplemented with 500 mg of carnitine/kg of diet. For Experiment 1, dietary treatments were fed to older birds (n = 12 birds/treatment) when they were 58 to 62 wk of age. For Experiment 2, younger birds were fed dietary treatments between 32 to 37 wk of age (n = 14 experimental units/treatment with three roosters composing an experimental unit for a total of 84 roosters). Semen traits and lipid peroxidation of sperm, determined by measuring malonaldehyde, were examined weekly. Feeding dietary carnitine to young and aging White Leghorn roosters ad libitum for 5 wk not only improved sperm concentration during the last half of supplementation but also reduced sperm lipid peroxidation. Testicular tissue of birds fed dietary carnitine for 5 wk was preserved as indicated by a reduction in multinucleated giant cells. These results suggest that dietary carnitine has antioxidant properties that may preserve sperm membranes in roosters, thereby extending the life span of sperm.

Multiple colonic ulcers caused by Churg-Strauss syndrome in a 15-year-old girl

Churg-Strauss syndrome (CSS), or allergic granulomatous angiitis, is an uncommon vasculitic syndrome that is found mainly in middle-aged adults. We describe a 15-year-old girl with CSS, diagnosed by histological findings and characteristic clinical features. The patient experienced two episodes of catastrophic gastrointestinal vasculitis, resulting in resection of 150 cm of small intestine and right hemicolectomy. Colonoscopic examination showed multiple colonic ulcers with active bleeding. The clinical course of the patient was grave and refractory to the therapy of steroid and cytotoxic drugs. In the world literature only two patients with multiple colonic ulcers caused by CSS have been reported, and very rare cases of childhood-onset CSS have been published. We reviewed CSS in children and found that the prognosis was poorer than that in adults.

The effect of dietary ascorbic acid on semen traits and testis histology of male turkey breeders

A 9-mo field trial was conducted to evaluate the effects of dietary L-ascorbic acid (AA) on semen traits of 144 male turkey breeders. Dietary AA treatments were initiated when birds were 30 wk of age. Semen and blood collection began at 32 wk of age. Three treatments with four pens per treatment and 12 birds per pen were fed 0, 75, and 150 mg/kg AA during the first 4 mo of their reproductive cycle. Levels of AA were doubled in the supplemented diets to 150 and 300 mg/kg during Months 5 to 9. Semen traits and blood AA were unaffected by dietary AA. When birds were 65 wk of age, testes were removed from 12 birds per treatment for histological analysis. Multinucleated giant cells (MCG), indicative of degeneration, were observed in the testes of 7 of the 12 control birds but were absent from AA-supplemented birds (P < 0.02). The antioxidant properties of AA may delay formation of these degenerative cells. In conclusion, dietary AA levels employed in the current study did not affect semen traits or testis weight but were associated with reduced formation of MGC in the testes of 65 wk-old breeder toms.

Molecular identification and characterization of turkey IFN-gamma gene

The cDNAs of turkey and chicken interferon gamma (IFN-gamma) were cloned and the functional activity of turkey and chicken IFN-gamma was compared. The coding region of turkey IFN-gamma gene encodes a predicted mature protein of 145 amino acids with a molecular weight at 16.8 kDa. Compared with type I IFN, the IFN-gamma between turkey and chicken also had the same size and high degree of identity at the nucleotide (96.0%) and amino acid (96.4%) sequence. Turkey IFN-gamma was cross-reactive with chicken cells. Both turkey and chicken IFN-gamma could induce production of nitric oxide by turkey or chicken macrophages. Turkey IFN-gamma also had similar degree of sensitivity to heat and pH 2.0 as chicken IFN-gamma. The functional activity of both turkey and chicken IFN-gamma could be neutralized by a monoclonal antibody specific to chicken IFN-gamma to a similar extent. These results indicated that IFN-gamma protein was cross-reactive between turkey and chicken.

DNA-mediated vaccination against infectious bursal disease in chickens

The objective of the present study was to investigate the feasibility of a DNA vaccine to protect chickens against infectious bursal disease virus (IBDV) infection. A plasmid DNA carrying VP2, VP4, and VP3 genes of the standard challenge (STC) strain of IBDV was constructed and designated as pCR3.1-VP243-STC. One-day-old chickens were intramuscularly injected with the plasmid pCR3.1-VP243-STC once (group D1), twice (group D2), or three times (group D3) at weekly intervals. Chickens at 3 weeks old were orally inoculated with IBDV strain STC and observed for 10 days after challenge. Immunization twice (group D2) or three times (group D3) with the plasmid pCR3.1-VP243-STC conferred protection for 50-100 or 80-100% of chickens, respectively, as evidenced by the absence of clinical signs, mortality, and bursal atrophy. Although chickens vaccinated once (group D1) with the plasmid pCR3.1-VP243-STC did not have clinical signs, they exhibited varying degree of bursal atrophy after challenge. Enzyme-linked immunosorbent assay (ELISA) antibody titers in chickens protected by the plasmid pCR3.1-VP243-STC were significantly lower (P<0.05) than those not protected 10 days after challenge. IBDV antigen was not detected in the bursae of chickens that were protected by receiving the plasmid pCR3.1-VP243-STC twice or three times. The results indicate that the constructed plasmid pCR3.1-VP243-STC as a DNA vaccine provided efficacious protection for chickens against IBDV infection.

Identification of genes associated with natural competence in Helicobacter pylori by transposon shuttle random mutagenesis

To identify genes involved in DNA transformation, we generated 1500 insertion mutants of a Helicobacter pylori strain by transposon shuttle mutagenesis. All mutant strains were screened for their frequency of natural transformation. A total of 20 mutant strains were found to exhibit a significantly decreased transformation frequency. DNA sequencing revealed seven genetic loci, including the reported comB locus, HP0017 (a putative virB4 homologue) and five loci without database match (HP0015, HP1089, HP1326, HP1424, and HP1473) from the 20 mutants. Reknockout of HP1326 revealed no impairment in natural transformation, while the other 5 mutants showed the same defective in natural transformation. Mutation of HP0017 severely impaired natural transformation both chromosome and plasmid DNA. Slot blot analysis revealed that some noncompetent strains had decreased virB4 RNA expression levels compared with competent strains. Nineteen ORFs had decreased expression levels in virB4 knockout mutant by microarray. Therefore, our data indicate that HP0017 is a virB4 homologue and is essential in the natural competence of H. pylori. HP0015, HP1089, HP1424, and HP1473 genes could be also involved in natural transformation.

IRF-1-mediated CAS expression enhances interferon-gamma-induced apoptosis of HT-29 colon adenocarcinoma cells

The expression of CAS is reported to be upregulated in a variety of human tumor cells, and such expression correlates with the development of tumors. CAS also plays a role in apoptosis. We investigated whether CAS expression affects the susceptibility of tumor cells to IFN-gamma-induced apoptosis. Our data show that IFN-gamma treatment induces CAS expression in HT-29 tumor cells. IFN-gamma-induced gene expression is primarily mediated by the transcriptional factor, IRF-1. Our data show that IRF-1 mediates IFN-gamma-induced CAS expression. Transfection of HT-29 cells with CAS expression vector did not induce apoptosis of cells; nevertheless, CAS overexpression greatly enhanced IFN-gamma-induced apoptosis of cells. CPP32 is regarded as one of the central apoptosis executioner molecules. CAS overexpression enhances IFN-gamma-induced CPP32 expression. These results indicate that tumor cells highly expressing CAS may be more susceptible to apoptosis induced by reagents that are capable of inducing CAS expression. Thus, CAS may be a target for the elimination of tumors.

Humoral and cellular immune responses in turkey poults infected with turkey coronavirus

The objective of the present study was to elucidate the kinetics of humoral and cellular immune responses of turkey poults infected with turkey coronavirus (TCV). Turkey poults were orally inoculated with TCV at 10 d of age, and the immune responses were analyzed at 1, 3, 7, 14, 21, 28, 42, and 63 d postinfection (PI) in three different experiments. Total Ig to TCV was initially detected at 7 and 14 d PI in Experiments 1 and 3. In addition, Ig gradually increased from 7 to 21 d PI and remained at 80 immunofluroescent antibody assay (IFA) titers or more thereafter. Lymphocyte proliferation responses of spleen cells to concanavalin A were higher in TCV-infected turkeys than in noninfected control turkeys with significant differences (P < 0.05) being noted at 14 and 63 d PI in Experiment 2 and at 3 and 28 d PI in Experiment 3. Strong IFA staining response to TCV antigen was observed in intestines of turkeys at 1, 3, and 7 d PI, and the response declined from 14 to 28 d PI in Experiment 3. In Experiment 3, the IgG isotype antibody response to TCV was markedly increased after 21 d PI and remained high until 63 d PI. The IgM isotype antibody response to TCV was 1.40 and 0.91 at 7 and 14 d PI, respectively. The IgA isotype antibody response to TCV was very low as detected at 7 (0.13), 14 (0.20), and 21 (0.17) d PI. Turkeys infected with TCV had significantly higher (P < 0.05) antibody response to sheep erythrocytes than noninfected controls at 7 d PI. Virus-specific lymphocyte proliferation response of spleen cells was significantly stimulated (P < 0.05) at 63 d PI in Experiment 3. The proportion of the CD4+ subpopulation of T lymphocytes was significantly increased (P < 0.05) at 1, 7, and 21 d PI in Experiment 3. The results indicate that humoral and cellular immunities to TCV are elicited in turkeys following infection with TCV.

Antimicrobial coatings: a remedy for medical device-related infections

This article discusses the mechanisms involved in the different approaches to antimicrobial coatings and reports on a new application that seems to offer an antimicrobial surface that is effective for long-term medical implants and suitable for a variety of drugs.

Fibronectin attachment protein homologue mediates fibronectin binding by Mycobacterium avium subsp. paratuberculosis

Attachment of Mycobacterium avium subsp. paratuberculosis to host tissue and penetration of mucosal surfaces are pivotal events in the pathogenesis of Johne's disease. Fibronectin (FN) binding is required for attachment and internalization of several mycobacteria by epithelial cells in vitro. The objective of this study was to further characterize the FN binding activity of M. avium subsp. paratuberculosis. Although the bacteria bound FN poorly at pH above 7, brief acid pretreatment greatly enhanced FN binding within the pH range (3 to 10) studied. A 4.6-kbp fragment from an M. avium subsp. paratuberculosis genomic library was found to contain a 1,107-bp open reading frame that shows very high nucleotide sequence identity with that of the FN attachment protein (FAP) gene of M. avium subsp. avium. Pretreatment of FN with an FN-binding peptide from M. avium subsp. avium FAP abolished FN binding, indicating that M. avium subsp. paratuberculosis binds FN in a FAP-dependent manner. Pretreatment of M. avium subsp. paratuberculosis with anti-FAP immunoglobulin G did not abrogate FN binding; blocking occurred only when anti-FAP was added together with FN. FAP was detected by immunofluorescence only in lipid-extracted M. avium subsp. paratuberculosis. Western blotting and immunoelectron microscopy revealed that FAP is located near the interior of the cell envelope of M. avium subsp. paratuberculosis. The results indicate that a FAP homologue mediates the attachment of FN to M. avium subsp. paratuberculosis. Further, given the subcellular location of FAP, it is considered that this protein operates at the terminus of a coordinated FN binding system in the cell envelope of M. avium subsp. paratuberculosis.

Clonality analysis using X-chromosome inactivation patterns by HUMARA-PCR assay in female controls and patients with idiopathic thrombocytosis in Taiwan

OBJECTIVE

Analysis of X-chromosome inactivation patterns (XCIPs) is a useful tool in the diagnosis of clonal disorders. The human androgen receptor (HUMARA) locus is especially useful for clonality study. The present study was conducted 1) to determine the heterozygosity rate for HUMARA locus in Taiwanese women, 2) to determine the frequency of excessive skewing in different cell types, and 3) to determine the utility of XCIPs in the differential diagnosis of thrombocytosis.

PATIENTS AND METHODS

XCIPs by HUMARA-PCR assay were performed on purified granulocytes and T cells from 73 female patients presenting with idiopathic persistent thrombocytosis (IT), 10 patients with reactive thrombocytosis (RT), and 46 bone marrow samples from female controls. XCIPs of buccal mucosa cells were also compared with those of T cells in 57 patients with IT. The percentage of clonal granulocytes was calculated after correcting for the degree of Lyonization in T cells.

RESULTS

The heterozygosity rate for the HUMARA gene was 89.1% in Taiwanese females. The median age of informative IT patients and controls was 59 (18-92) and 58 (19-89), respectively. Excessive skewing (allele ratio <0.33) was more frequent in granulocytes than in T cells in both controls (12/43 vs 9/43, p = 0.080) and IT patients (56/64 vs 25/64, p < 0.001). XCIPs were the same for both buccal mucosa and T cells in 43 patients but were different in 14 patients. Of the 43 informative controls, 31 had a polyclonal pattern; an ambiguous pattern was found in nine; and the remaining three, aged 71, 73, and 80, respectively, had a clonal pattern. A clonal pattern was found in 42 IT patients, a polyclonal pattern in 12, and an ambiguous pattern in 10 of the 64 IT patients. The frequency of clonal, polyclonal, and ambiguous patterns in the 40 IT patients with age < or = 65 was 55.0%, 30.0%, and 15.0%, respectively. None of the IT patients aged >65 had a polyclonal disease. IT patients aged >65 had a significantly higher frequency of clonal pattern (p = 0.030) and a significantly lower frequency of polyclonal pattern (p = 0.002) than those with age <65. Of the eight heterozygous patients with RT, one aged 80 exhibited a clonal pattern, and the remaining seven had a polyclonal pattern.

CONCLUSIONS

The present study on Taiwanese females showed a heterozygosity rate of 89.1% for the HUMARA gene. Our results confirmed that IT is a heterogeneous disorder in terms of clonality. Twenty-three percent of IT patients exhibited a greater than 20% difference in allele expression for buccal mucosa and T cells. Presence of a clonal XCIP in young patients with IT can serve as a positive marker for the diagnosis of clonal thrombocytosis, and elderly patients with polyclonal XCIPs are unlikely to have essential thrombocythemia.

Nucleocapsid protein gene sequence analysis reveals close genomic relationship between turkey coronavirus and avian infectious bronchitis virus

Antibodies to infectious bronchitis virus (IBV) cross-react with turkey coronavirus (TCV) in immunofluorescence assay (IFA) indicating that IBV and TCV may share an amino acid sequence similarity. To determine its extent, the gene encoding the nucleocapsid (N) protein of TCV was amplified by reverse transcription-PCR (RT-PCR) from RNA purified from intestines of embryos of turkeys infected with various TCV isolates and from allantoic fluid of chicken embryos infected with IBV M41 strain, the obtained N genes were cloned, sequenced and compared with known sequences of N genes of five IBV strains. The primers for amplification were designed from the genome of IBV PCR products were obtained only from two of eight TCV isolates tested. It was found that the two TCV isolates were identical with five IBV strains by 90.1-94.1% at the N gene level. It was also observed that the N gene of eight TCV isolates originating from various regions of the USA could not be amplified by the primers designed from the N gene of bovine coronavirus (BCV).

Subtyping HIV-1 infections in Taiwan using peptide-enzyme immunoassay, reverse transcription-polymerase chain reaction, and sequencing

BACKGROUND AND PURPOSE

There are important questions about epidemiologic transmission patterns as well as the possibility that genetic and phenotypic differences in human immunodeficiency virus type 1 (HIV-1) affect transmissibility, infectivity, pathogenicity, and response to therapy and vaccines. To delinate the genetic heterogeneity of HIV-1 and the association of subtypes with risk factors and location of residence in Taiwan, subtypes of HIV-1 in Taiwanese patients were identified and a phylogenetic study was performed. In addition, the accuracy of peptide-enzyme immunoassay (EIA) using serum samples from Taiwanese patients infected with HIV-1 was investigated.

METHODS

Peptide-EIA was used to give a preliminary subtype of HIV-1-positive serum samples collected from different areas of Taiwan. Reverse transcription (RT)-polymerase chain reaction (PCR) and genetic sequencing were used to confirm the peptide-EIA results and to construct a phylogenetic tree.

RESULTS

Among the 149 serum samples, 98 were subtype B (66%), 38 subtype E (25%), two subtype Thai-B (1.3%), one subtype G (0.7%), and one subtype C (0.7%). Comparison of risk factors for HIV-1 infection and subtype revealed that most B subtype infections (59/98) occurred in homosexual or heterosexual patients, whereas 28 of 38 E subtype infections occurred in heterosexual patients. The B/E ratio was significantly different (p < 0.05) in Taipei than in other areas of Taiwan.

CONCLUSIONS

These results suggest that the predominant subtype of HIV-1 infection in Taiwan is B, followed by E, and that the distribution of HIV-1 subtypes in Taiwan is similar to that of Thailand, although the genetic sequences are distinct. Homosexuality, heterosexuality, bisexuality, and intravenous drug use behaviors affect the distribution of different subtypes of HIV-1 infection. Peptide-EIA in conjunction with RT-PCR and sequencing can provide accurate subtyping of HIV-1 infection.

Antimicrobial susceptibility of Mycoplasma hyorhinis

A broth microdilution technique was used to determine the antimicrobial susceptibility of 15 field isolates of Mycoplasma hyorhinis to 10 antimicrobial agents, representative of different classes, and contrasting newer agents to existing ones. For the macrolides, the MIC(90) for tylosin and tilmicosin was 1 and 4 microg/ml, respectively, but was > or = 16 microg/ml for erythromycin. Tetracycline, lincomycin and enrofloxacin each had an MIC(90) of 2 microg/ml. The mycoplasma had similar levels of susceptibility to the aminoglycoside and aminocyclictol classes exhibiting an MIC(90) of 4 microg/ml for gentamicin and 2 microg/ml for spectinomycin. The isolates exhibited high MICs to trimethoprim/sulfamethoxazole with an MIC(90) > or = 16/304 microg/ml. In summary, M. hyorhinis isolates from the US had low MICs against a variety of antimicrobials tested, with the exception of erythromycin and trimethoprim/sulfamethoxazole.

Multiple endocrine neoplasia in a dog

Multiple endocrine neoplasms, including an insulinoma, bilateral adrenocortical adenocarcinomas and an aortic paraganglioma, were diagnosed after euthanasia in a 12-year-old spayed female dog of mixed breed with a history of progressive anorexia, vomiting, diarrhoea, weight loss, polyuria and polydipsia, regenerative anaemia and hypoglycaemia. The clinical, gross pathological, microscopical, immunohistochemical and ultrastructural findings were consistent with the human syndrome of multiple endocrine neoplasia.

Immunoglobulin D multiple myeloma

BACKGROUND

Immunoglobulin D (IgD) multiple myeloma (MM) is rare, accounting for less than 2% of all patients with MM in Western countries. In Taiwan, the frequency and clinicopathologic features of IgD MM have not yet been reported.

METHODS

The clinicopathologic features and treatment outcome of patients with IgD MM diagnosed between January 1, 1982, and December 31, 1998, in Chang Gung Memorial Hospital were retrospectively reviewed. Nineteen patients with IgD MM were diagnosed. Of those patients, the medical records of 16 were available for review.

RESULTS

Most of the patients were male (11/16) with a median age of 59 years. The most common presenting features included bone pain (56%), gastrointestinal discomfort (38%), general malaise (38%), and body weight loss (25%). The majority of patients had cytopenia (88%), renal function impairment (75%), hypercalcemia (63%), hyperuricemia (69%), elevated beta 2-microglobulin levels (86%), and Bence Jones proteinuria (92%). Serum protein electrophoresis showed an M-peak in 9 cases (9/12), whereas immunoelectrophoresis or immunofixation identified an IgD monoclonal gammopathy in all 16 patients. All of the M-proteins were of a lambda-light chain type. The IgD level ranged between 584 and 129,000 IU/ml (normal, < 100 IU/ml). All the patients had stage III disease except one (stage I). Four patients were still alive at the time of this analysis. The median survival time was 12 months. Infection was the leading cause of death (50%).

CONCLUSION

The present series showed that IgD MM had aggressive clinical features, male predominance, a high frequency of renal function impairment, high incidence of M-protein undetected by serum protein electrophoresis, a predilection for lambda-light chains, and a short period of survival.

Detection of antibody to turkey coronavirus by antibody-capture enzyme-linked immunosorbent assay utilizing infectious bronchitis virus antigen

An antibody-capture enzyme-linked immunosorbent assay (ELISA) for detection of antibody to turkey coronavirus (TCV) utilizing infectious bronchitis virus (IBV) antigen was developed. Anti-TCV hyperimmune turkey serum and normal turkey serum were used as positive or negative control serum for optimization of the ELISA system. Goat anti-turkey immunoglobulin G (light plus heavy chains) conjugated with horseradish peroxidase was used as detector antibody. The performance of the ELISA system was evaluated with 45 normal turkey sera and 325 turkey sera from the field and the cutoff point was determined. Serum samples of turkeys experimentally infected with TCV collected sequentially from 1 to 63 days postinfection were applied to the established antibody-capture ELISA using IBV antigens. The optimum conditions for differentiation between anti-TCV hyperimmune serum and normal turkey serum were serum dilution at 1:40 and conjugate dilution at 1:1600. Of the 325 sera from the field, 175 were positive for TCV by immunofluorescent antibody (IFA) assay. The sensitivity and specificity of the ELISA relative to IFA test were 93.1% and 96.7%, respectively, based on the results of serum samples from the field turkey flocks using the optimum cutoff point of 0.18 as determined by the logistic regression method. The ELISA values of all 45 normal turkey sera were completely separated from that of IFA-positive sera. The ELISA results of serum samples collected from turkeys experimentally infected with TCV were comparable to that of the IFA assay. Reactivity of anti-rotavirus, anti-reovirus, anti-adenovirus, or anti-enterovirus antibodies with the IBV antigens coated in the commercially available ELISA plates coated with IBV antigens could be utilized for detection of antibodies to TCV in antibody-capture ELISA.

Association of a T29-->C polymorphism of the transforming growth factor-beta1 gene with genetic susceptibility to myocardial infarction in Japanese

BACKGROUND

Transforming growth factor-beta (TGF-beta) is an important regulator of vascular remodeling and is involved in the pathogenesis of atherosclerosis. A T-->C transition at nucleotide 29 of the TGF-beta1 gene results in a Leu-->Pro substitution at amino acid 10 of the signal peptide. We have now examined a possible association of TGF-beta1 genotype with myocardial infarction (MI) in a Japanese population.

METHODS AND RESULTS

TGF-beta1 genotype was determined in 315 Japanese patients (234 men and 81 women) with MI and 591 control subjects (289 men and 302 women). We found that age, body mass index, and incidence of habitual smoking, hypertension, diabetes mellitus, and hypercholesterolemia did not differ between the 2 groups for either men or women. Multivariable logistic regression analysis, however, demonstrated the frequency of the T allele to be significantly higher in male subjects with MI than in controls (TT + TC versus CC; P<0.0001, odds ratio 3.5, 95% CI 2.0 to 6.3). In contrast, the T allele was not associated with the prevalence of MI in women. In both male MI patients and controls, the serum concentration of TGF-beta1 was significantly higher in individuals with the CC genotype than in subjects with the TT or TC genotype.

CONCLUSIONS

Findings suggest that the T allele at nucleotide 29 in the TGF-beta1 gene is a risk factor for genetic susceptibility to MI, at least in middle-aged Japanese men.