Biofilm deficiency in polysaccharide intercellular adhesin-negative variants of staphylococcus epidermidis selected by subminimal inhibitory concentrations of gentamicin

Staphylococcus epidermidis is a cause of orthopedic device-related infection, and to treat such infection, biofilms should be controlled. Polysaccharide intercellular adhesin (PIA) is associated with the biofilm-forming ability of staphylococcal strains. PIA in biofilm-positive staphylococcal strains can be detected by the Congo red agar (CRA) method. In this study, we used the CRA method to examine the effects of subminimal inhibitory concentrations (sub-MICs) of 11 antibacterial agents on PIA production by S. epidermidis. We found that the PIA-negative variants were selected only by sub- MICs of gentamicin (GM). This PIA-negative phenotype was maintained over several generations in the absence of GM. Such selection occurred in six of eight clinical isolates, as well as in the biofilm-positive control strain. No such selection occurred with aminoglycoside antibiotics except for GM. Most of the PIA-negative variants that were selected by GM showed a markedly lower biofilm-forming ability on stainless steel washers than their untreated parent strains. In conclusion, variants with lower biofilmforming ability may be selected by a sub-MIC of GM. Investigation of the reason why variants with reduced biofilm-forming ability can be selected in the presence of sub-MICs of GM may contribute to strategies against biofilm-related infections

A case of retroesophageal right subclavian artery, with special reference to the second intercostal artery, retroesophageal right vertebral artery, and thoracic duct

We report a case of retroesophageal right subclavian artery identified in a 59-year-old Japanese female during routine dissection in Nagasaki University School of Medicine. This kind of variation is relatively rare; however, reports of such cases have accumulated. We paid attention to the intersegmental arteries and above all, the second intercostal artery. On the other hand, there have been reports of a retroesophageal right vertebral artery, although such cases are extremely rare. It is considered that both retroesophageal arteries are formed by similar mechanisms. In other words, the distal part of the right dorsal aorta remained in such cases. However, in the case of a retroesophageal right vertebral artery, there might be the possibility of intercostal arteries developing into the vertebral artery, and we discuss such points here

Double-Sided Superior Vena Cava: Developmental Considerations Associated with the Thymic Veins

The superior vena cava is usually located only on the right side, but persistence of the left superior vena cavais observed in about 0.3 to 0.5 % of adults. A routine dissection of the cadaver of a 91-year-old Japanese female, whose cause of death was sepsis due to cholecystitis, was performed at Nagasaki University and revealed a double-sided superior vena cava. On the right side, the superior vena cava opened to the right atrium, while on the left, it opened into the extended coronary sinus. Veins in the left head, neck and upper limb regions joined to form the persistent left superior vena cava, with eventual drainage into the expanded coronary vein. An anastomosing branchoccurred between each superior vena cava, and two thymic veins opened to the anastomosing branch. The azygos vein in the azygos venous system opened into the right superior vena cava, whereas a hemi-azygos vein opened into the azygos vein. The accessory hemi-azygos vein also opened into the azygos vein and opened cranially into the left superior vena cava. The left supreme intercostal vein also opened into the left superior vena cava. Several studies have reported a persistent left superior vena cava and the various considerations for its occurrence. Here, we propose a new hypothesis for the embryonic development of the persistent left superior vena cava with the thymic vein. This hypothesis essentially states that the left brachiocephalic vein fails to mature due to inadequate venous return from the thymic vein during the embryonic period, and the left superior vena cava then remains to maintain venous return from the left head, neck and upper limb. We also discuss the clinical significance of the persistent left superior vena cava

An Ancient Skeleton with Multiple Osteoblastic Bone Lesions Containing a Scapular Sunburst Appearance from a 5th?6th Century Grave Excavated in Oita, Japan

A human skeleton of a middle-aged adult male was found in a 5th-6th century Kinoue-Kodo stone coffin excavated from the southwest marginal region of the Oita plains, northeast Kyushu, Japan. The skeleton was buried respectfully in the ancient tomb, and red pigment was applied to his face after death. We report herein findings from computed tomography imaging of the skeleton and discuss the multiple osteoblastic lesions identified in the humerus, scapula, clavicle, vertebra, pelvic bones, and skull of this individual. These lesions comprised cortical bone thickening with periosteal reaction localized to the surface and osteosclerotic changes mainly observed in the trabecular structure of cancellous bone. In particular, a typical sunburst pattern was also noted on the left scapula as another characteristic lesion found in this case. By differential diagnosis, the disease suffered by this individual was most likely to be metastatic bone tumors, especially of prostate cancer. This person may have survived until many bone metastases had developed throughout his whole body

Measurement of femoral axial offset

Purpose to examine the accuracy and reproducibility of the femoral axial offset measured from the retrocondylar plane by computed tomography (CT). Bone specimens of the femur of 15 males and 15 females were analyzed. CT imaging was performed and data of the coordinates were collected (center of femoral head, center of an ellipse around greater trochanter, center of an ellipse around the base of femoral neck, posterior edge of great trochanter, and both posterior condyles). The angle between the line connecting center of the femoral head and center of an ellipse around greater trochanter and the line connecting both posterior condyles was set as anteversion 1. The angle between the line connecting the center of femoral head and center of an ellipse around base of the femoral neck and the line connecting both posterior condyles was set as anteversion 2. The femoral axial offset was measured from the retrocondylar plane. Measurements were performed three times on the same subject, and intrarater reliability (ICC) was determined. In addition, interrater reliability (ICC) was determined by comparing data from three raters. The mean value for anteversion 1 was 20.1° for males and 22.7° for females. The values for anteversion 2 were 16.0° and 19.9° for males and females, respectively. Offset was 34.0 and 33.4 mm in males and females, respectively. Intrarater ICC and interrater ICC exceeded 0.81 for both methods, suggesting that the method of measurement was reliable. Accuracy and reproducibility of the measurement of femoral axial offset from the retrocondylar plane were high

Periarticular Osteophytes as an Appendicular Joint Stress Marker (JSM): Analysis in a Contemporary Japanese Skeletal Collection

Objective: The aim of this study was to investigate the possibility that periarticular osteophytes plays a role as a appendicular joint stress marker (JSM) which reflects the biomechanical stresses on individuals and populations. Methods: A total of 366 contemporary Japanese skeletons (231 males, 135 females) were examined closely to evaluate the periarticular osteophytes of six major joints, the shoulder, elbow, wrist, hip, knee, and ankle and osteophyte scores (OS) were determined using an original grading system. These scores were aggregated and analyzed statistically from some viewpoints. Results: All of the OS for the respective joints were correlated logarithmically with the age-at-death of the individuals. For 70 individuals, in whom both sides of all six joints were evaluated without missing values, the age-standardized OS were calculated. A right side dominancy was recognized in the joints of the upper extremities, shoulder and wrist joints, and the bilateral correlations were large in the three joints on the lower extremity. For the shoulder joint and the hip joint, it was inferred by some distinctions that systemic factors were relatively large. All of these six joints could be assorted by the extent of systemic and local factors on osteophytes formation. Moreover, when the age-standardized OS of all the joints was summed up, some individuals had significantly high total scores, and others had significantly low total scores; namely, all of the individuals varied greatly in their systemic predisposition for osteophytes formation. Conclusions: This study demonstrated the significance of periarticular osteophytes; the evaluating system for OS could be used to detect differences among joints and individuals. Periarticular osteophytes could be applied as an appendicular joint stress marker (JSM); by applying OS evaluating system for skeletal populations, intra-skeletal and inter-skeletal variations in biomechanical stresses throughout the lives could be clarified

Significant Asymmetry of the Bilateral Upper Extremities of a Skeleton Excavated from the Mashiki-Azamabaru Site, Okinawa Island, Japan

The human skeleton of a young adult male with marked asymmetry of the bilateral upper extremities was excavated from the Mashiki-Azamabaru site (3000–2000 BCE) on the main island of Okinawa in the southwestern archipelago of Japan. The skeleton was buried alone in a corner of the cemetery. In this study, morphological and radiographic observations were made on this skeleton, and the pathogenesis of the bone growth disorder observed in the left upper limb was discussed. The maximum diameter of the midshaft of the humerus was 13.8 mm on the left and 21.2 mm on the right. The long bones comprising the left upper extremity lost the structure of the muscle attachments except for the deltoid tubercle of the humerus. The bone morphology of the right upper extremity and the bilateral lower extremities was maintained and was close to the mean value of females from the Ohtomo site in northwestern Kyushu, Japan, during the Yayoi period. It is assumed that the anomalous bone morphology confined to the left upper extremity was secondary to the prolonged loss of function of the muscles attached to left extremity bones. In this case, birth palsy, brachial plexus injury in childhood, and acute grey matter myelitis were diagnosed. It was suggested that this person had survived into young adulthood with severe paralysis of the left upper extremity due to injury or disease at an early age

Characterization of Individuals with Sacroiliac Joint Bridging in a Skeletal Population: Analysis of Degenerative Changes in Spinal Vertebrae

Theaimof this study was to characterize the individualswith sacroiliac joint bridging (SIB) by analyzing the degenerative changes intheirwhole vertebral column and comparing themwith the controls.Atotal of 291modern Japanesemale skeletons,with an averageage at death of 60.8 years, were examined macroscopically. They were divided into two groups: individuals with SIB and thosewithout bridging (Non-SIB).The degenerative changes in their whole vertebral column were evaluated, and marginal osteophytescores (MOS) of the vertebral bodies and degenerative joint scores in zygapophyseal jointswere calculated. SIBwas recognized in 30individuals froma total of 291 males (10.3%).The average of age at death in SIB group was significantly higher than that in Non-SIBgroup. The values ofMOS in the thoracic spines, particularly in the anterior part of the vertebral bodies, were consecutively higherin SIB group than in Non-SIB group. Incidence of fused vertebral bodies intervertebral levels was obviously higher in SIB groupthan in Non-SIB group. SIB and marginal osteophyte formation in vertebral bodies could coexist in a skeletal population of men.Some systemic factors might act on these degenerative changes simultaneously both in sacroiliac joint and in vertebral column