Application of Methods for a Morphological Analysis of the Femoral Diaphysis Based on Clinical CT Images to Prehistoric Human Bone: Comparison of Modern Japanese and Jomon Populations from Hegi Cave, Oita, Japan.

A morphological analysis of ancient human bones is essential for understanding life history, medical history, and genetic characteristics. In addition to external measurements, a three-dimensional structural analysis using CT will provide more detailed information. The present study examined adult male human skeletons excavated from Hegi cave, Nakatsu city, Oita Prefecture. CT images were taken from the femurs of adult males (Initial/Early Jomon Period (n = 10) and Late Jomon Period (n = 5)). Cross-sectional images of the diaphysis from below the lesser trochanter to above the adductor tubercle were obtained using the method established by Imamura et al. (2019) and Imamura et al. (2021). Using Excel formulas and macros, the area of cortical bone, thickness, and degree of curvature were quantitatively analyzed. The results were compared with data on modern Japanese. The maximum thickness of cortical bone in the diaphysis and the degree of the anterior curvature were significantly greater in Late Jomon humans than in the other groups. In contrast to modern humans, the majority of Jomon femurs showed the S-shaped curvature with the medial side at the top position and the lateral side at the lower position. The present results demonstrate that Late Jomon humans had a wider range of activity than the other groups and also provide insights into diseases in the hip and knee joints of Jomon humans.

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.

Ancient Jomon genome sequence analysis sheds light on migration patterns of early East Asian populations.

Anatomically modern humans reached East Asia more than 40,000 years ago. However, key questions still remain unanswered with regard to the route(s) and the number of wave(s) in the dispersal into East Eurasia. Ancient genomes at the edge of the region may elucidate a more detailed picture of the peopling of East Eurasia. Here, we analyze the whole-genome sequence of a 2,500-year-old individual (IK002) from the main-island of Japan that is  characterized with a typical Jomon culture. The phylogenetic analyses support multiple waves of migration, with IK002 forming a basal lineage to the East and Northeast Asian genomes examined, likely representing some of the earliest-wave migrants who went north from Southeast Asia to East Asia. Furthermore, IK002 shows strong genetic affinity with the indigenous Taiwan aborigines, which may support a coastal route of the Jomon-ancestry migration. This study highlights the power of ancient genomics to provide new insights into the complex history of human migration into East Eurasia.

A health crisis during the Japanese Medieval Period: A new paleodemographic perspective.

OBJECTIVE: To test the hypothesis that the "Little Ice Age" (LIA) (in Japan, ˜1440 - 1730 CE) co-occurred with unique age-at-death patterns. MATERIALS: 810 adult human skeletons from the early Medieval Period (EMP) of Japan, which are contemporaneous with the Medieval Warm Period (10th - mid 13th century AD), and the late Medieval Period (LMP) and Edo Period, which are contemporary with the LIA. METHODS: Age at death and sex was determined for each skeleton and demographic profiles of the Yayoi Period (5th century BC - 3rd century AD), EMP, LMP, and Edo site samples were compared. Paleopathological data from previously published reports were evaluated. RESULTS: The EMP had the highest mortality among young adults. Longevity increased in the samples (LMP and Edo) contemporaneous with the LIA. CONCLUSIONS: EMP early age-at-death was the result of poor community health, violent death, and frequent large-scale natural catastrophes. The LMP and Edo Period samples have an older age-at-death pattern and higher frequency of stress markers, argued to be a consequence of a colder climate. SIGNIFICANCE: This study is the first to synthesize paleodemographic and paleopathological data on a large scale to assess the possible effects of the Little Ice Age in Japan. LIMITATIONS: Varying skeletal preservation and focus on adult skeletons reduces the ability to evaluate health throughout the life span. SUGGESTIONS FOR FURTHER RESEARCH: Analysis of nonadult remains and multiple health indicators will likely shed more light on the effects of the Little Ice Age in Japan.

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.

A case of anomalous horizontal fissure and hypoplastic middle lobe of the right lung / Un caso de fisura horizontal anómala y lóbulo medio hipoplásico del pulmón derecho

During dissection practice for medical students at Nagasaki University, a horizontal fissure and hypoplastic middle lobe were encountered in the right lung of an 81-year-old Japanese female. In a normal right lung, the horizontal fissure is situated anterior to the oblique fissure. On the contrary, in the present case, the horizontal fissure was situated posterior to the oblique fissure. We identified a small, additional lobe on the medial surface of this lung. It was situated in the medial part of the oblique fissure, and was determined to be a small hypoplastic middle lobe. As a result of the hypoplasia of the middle lobe, the original horizontal fissure may have disappeared from the anterior surface. The horizontal fissure, in this case, may be a compensatory additional fissure that developed within the inferior lobe. This horizontal fissure was incomplete, both in length and depth. The left lung was normal. This case might be very rare; however, it may aid in the understanding of normal lung development. Therefore, we report this case, including its bronchial branching and vascular distribution.

Durante la práctica de disección para estudiantes de medicina en la Universidad de Nagasaki, se encontró una fisura horizontal y un lóbulo medio hipoplásico en el pulmón derecho de una mujer japonesa de 81 años de edad. En un pulmón derecho normal, la fisura horizontal está situada anterior a la fisura oblicua. Por el contrario, en el presente caso, la fisura horizontal estaba situada posterior a la fisura oblicua. Se identificó un pequeño lóbulo adicional en la superficie medial de este pulmón. Estaba situado en la parte medial de la fisura oblicua, y se determinó que era un pequeño lóbulo medio hipoplásico. Como resultado de la hipoplasia del lóbulo medio, la fisura horizontal original puede haber desaparecido de la superficie anterior. La fisura horizontal, en este caso, puede ser una fisura adicional compensatoria que se desarrolla dentro del lóbulo inferior. Esta fisura horizontal era incompleta, tanto en longitud como en profundidad. El pulmón izquierdo era normal. Este caso podría ser muy raro; Sin embargo, puede ayudar en la comprensión del desarrollo pulmonar normal. Por lo tanto, informamos este variación, incluyendo su ramificación bronquial y la distribución vascular.

Degenerative changes of the sacroiliac auricular joint surface-validation of influential factors.

The purpose of this study was to clarify the relevance of degenerative changes in the sacroiliac joint (SIJ) and the joints in the lower limb and lumbar spine using age estimation methods. We also examined the shape of the auricular surface to determine the effect of degenerative changes on each joint. A total of 200 iliac auricular surfaces from 100 Japanese male skeletons were examined macroscopically in accordance with conventional methods of age estimation. From the obtained estimated age, we calculated the deflection values, which represented the degree of degenerative changes of the joints. For comparison, we used osteophyte score data of the hip, knee, and zygapophyseal joints in lumbar spines from previous studies which had used the same bone specimens. As a quantitative indicator of auricular surface morphology, we defined the constriction ratio (CR) of the auricular surface and compared the CR values obtained with various measured values. Degenerative changes in the SIJ were positively correlated with those in both the hip joint and zygapophyseal joint, but a correlation with knee joints was found only on the left side. In skeletons from individuals aged ≥60 years as time of death, the CR was significantly different between the group with high scores and those with low scores in both the hip and sacroiliac joints. It has been suggested that degenerative changes in SIJs interact with those in the hip joint and zygapophyseal joint. In addition, the shape of the auricular surface may also be a relevant factor for degenerative changes in these joints.

Characterization of individuals with sacroiliac joint bridging in a skeletal population: analysis of degenerative changes in spinal vertebrae.

The aim of this study was to characterize the individuals with sacroiliac joint bridging (SIB) by analyzing the degenerative changes in their whole vertebral column and comparing them with the controls. A total of 291 modern Japanese male skeletons, with an average age at death of 60.8 years, were examined macroscopically. They were divided into two groups: individuals with SIB and those without bridging (Non-SIB). The degenerative changes in their whole vertebral column were evaluated, and marginal osteophyte scores (MOS) of the vertebral bodies and degenerative joint scores in zygapophyseal joints were calculated. SIB was recognized in 30 individuals from a total of 291 males (10.3%). The average of age at death in SIB group was significantly higher than that in Non-SIB group. The values of MOS in the thoracic spines, particularly in the anterior part of the vertebral bodies, were consecutively higher in SIB group than in Non-SIB group. Incidence of fused vertebral bodies intervertebral levels was obviously higher in SIB group than 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.

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.

Relation between bilateral differences in internal jugular vein caliber and flow patterns of dural venous sinuses.

We measured the calibers of the left and right internal jugular veins (IJV) and sizes of the left and right transverse sinuses (TS) in 91 cadavers, compared them between the left and right sides, and also evaluated the drainage patterns of the superior sagittal sinus (SSS) and straight sinus (=rectal sinus, RS) in the torcular Herophili. In addition, the running type of groove for the SSS was investigated. The results were as follows: (1) The right IJV was larger in 81.3 %, while the left IJV was larger in only 11.0 %. (2) The drainage pattern of the SSS was the right type in 73.6 %, intermediate type in 14.3 %, and left type in 12.1 %. (3) The drainage pattern of the RS was the right type in 27.5 %, intermediate type in 25.3 %, and left type in 47.3 %. (4) The running type of groove for the SSS was mostly consistent with the drainage pattern of this sinus. (5) Concerning the relationships among these findings including the size of the TS, the drainage pattern of the SSS was mostly consistent with the side showing a larger TS as well as the side showing a larger IJV. These results suggest that the pattern of drainage of the SSS into the left and right TS affects the size of the TS and the running type of groove for the SSS, and is also closely involved in the caliber of the IJV. A discussion of the embryological, genetic, and clinical implications of these results is presented.

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.

The nerves to the plantaris muscle and a bipennate part of the soleus muscle.

We performed nerve fiber analysis of the nerve to the plantaris muscle in ten cases. Macroscopically, the nerve to the plantaris muscle has a tendency to branch off from the tibial nerve itself independent of the nerves to the gastrocnemius and soleus muscles (the triceps surae muscle). After removing the epineurium of the tibial nerve, it was revealed that, in all ten cases, the nerve to the plantaris muscle formed a common funicular trunk with the nerve to a bipennate part of the soleus. This trunk is akin to the nerves to the deep muscles of the calf. In addition, in five of the ten cases, the nerve to the plantaris muscle had another component, which arose from the branch to the popliteus muscle. By removing the perineurium of the nerves concerned, it became clear that the elements of the nerve to the plantaris muscle, and of the nerve to the bipennate part of the soleus, had an intimate relation (inseparable). On the other hand, the elements of the nerve to the plantaris muscle and those to the popliteus were separable and they showed different routes proximally. Based on the present findings derived from nerve fiber analysis, we postulate that the plantaris muscle and bipennate part of the soleus muscle were probably derived from the deep muscle anlage of the calf in spite of their topographical closeness to the superficial muscles of the calf.

Geographic variation in body form of prehistoric Jomon males in the Japanese archipelago: its ecogeographic implications.

Diversity of human body size and shape is often biogeographically interpreted in association with climatic conditions. According to Bergmann's and Allen's rules, populations in regions with a cold climate are expected to display an overall larger body and smaller/shorter extremities than those in warm/hot environments. In the present study, the skeletal limb size and proportions of prehistoric Jomon hunter-gatherers, who extensively inhabited subarctic to subtropical areas in the ancient Japanese archipelago, were examined to evaluate whether or not the inter-regional differences follow such ecogeographic patterns. Results showed that the Jomon intralimb proportions including relative distal limb lengths did not differ significantly among five regions from northern Hokkaido to the southern Okinawa Islands. This suggests a limited co-variability of the intralimb proportions with climate, particularly within genealogically close populations. In contrast, femoral head breadth (associated with body mass) and skeletal limb lengths were found to be significantly and positively correlated with latitude, suggesting a north-south geographical cline in the body size. This gradient therefore comprehensively conforms to Bergmann's rule, and may stem from multiple potential factors such as phylogenetic constraints, microevolutionary adaptation to climatic/geographic conditions during the Jomon period, and nutritional and physiological response during ontogeny. Specifically, the remarkably small-bodied Jomon in the Okinawa Islands can also be explained as an adjustment to subtropical and insular environments. Thus, the findings obtained in this study indicate that Jomon people, while maintaining fundamental intralimb proportions, displayed body size variation in concert with ambient surroundings.

Anatomical study of partial anomalous pulmonary venous return with special references to the bronchial vein: supplementary report.

After the authors' previous report an additional case of partial anomalous pulmonary venous return was encountered during dissection practice for medical students. In an 87-year-old Japanese male cadaver, the anomalous vein from the right upper lobe drained into the superior vena cava at a point just below the entrance of the azygos vein. This case is similar to the first case in the authors' previous report, but the anomalous vein was recognized before dissection of the lung began. Therefore, findings were more precisely observed. The anomalous pulmonary vein was 16 mm in diameter and had three branches, which drained the regions of the apex, the anterior segment and a part of the posterior segment of the right upper lobe. The other veins from the right lung gathered into two pulmonary veins, measuring 21 mm and 18 mm in diameter, respectively, and returned to the left atrium as usual. It is noteworthy that the anomalous vein received the bronchial vein from the right upper lobe bronchus. The azygos vein also received the bronchial veins from the lower part of the trachea and from the right middle and lower lobe bronchi. The theory that the bronchial vein plays an important role in the occurrence of the anomalous pulmonary drainage is further supported by this finding.

The inferior supernumerary renal arteries: a classification into three types.

Among cases that had multiple renal arteries on one side, an inferior supernumerary renal artery was found in 24/270 cases (ca. 9%) on the right and in 19/270 cases (ca. 7%) on the left, together with the usual renal artery. We have noticed that there are correlations between their levels of origin from the aorta and their positional relation to the ureter and the inferior vena cava (IVC). An inferior supernumerary renal artery (InfRA) of lower origin passes in front of the IVC and behind the ureter. An InfRA of middle origin passes in front of both the IVC and the ureter. An InfRA of upper origin passes behind the IVC and in front of the ureter or renal pelvis. In addition there was a tendency for the lower origin type to have an ureteric branch, while the middle and upper origin types had a gonadal branch. These findings suggest that different derivations lead to the inferior supernumerary renal arteries.

Consideration of the potential courses of the common iliac artery.

We encountered a rare case of the left common iliac artery in a 92-year-old Japanese female cadaver during dissection practice for medical students. The artery entered into the small pelvis without branching to the external iliac artery. There, it went down slightly medially and then turned laterally and passed behind the first sacral nerve. The artery ran anterolaterally further and returned to the greater pelvis and became the external iliac artery, which continued to the femoral artery as usual. During the course in the small pelvis, the artery branched to give rise to each branch of the internal iliac artery. We speculate that in the present case, a communication between the median sacral artery and the superior gluteal artery, passing behind the first sacral nerve, enlarged and compensated the usual common iliac artery.

New method for estimation of adult skeletal age at death from the morphology of the auricular surface of the ilium.

A new method for estimating skeletal age at death from the morphology of the auricular surface of the ilium is presented. It uses a multiple regression analysis with dummy variables, and is based on the examination of 700 modern Japanese skeletal remains with age records. The observer using this method needs only to check for the presence or absence of nine (for a male) or seven (for a female) features on the auricular surface and to select the parameter estimates of each feature, calculated by multiple regression analysis with dummy variables. The observer can obtain an estimated age from the sum of parameter estimates. It is shown that a fine granular texture of the auricular surface is typical of younger individuals, whereas a heavily porous texture is characteristic of older individuals, and that both of these features are very useful for estimating age. Our method is shown here to be more accurate than other methods, especially in the older age ranges. Since the auricular surface allows more expedient observations than other parts of the skeleton, this new method can be expected to improve the overall accuracy of estimating skeletal age at death.

An anatomical study of the partial anomalous pulmonary venous return with special references to the bronchial vein.

Two examples of partial anomalous drainage of the pulmonary vein were detected at dissection. The first case was found in a 70-year-old female Japanese. An aberrant vein, approximately 6 mm in diameter, that derived from the upper lobe of the right lung was observed to drain into the superior vena cava at a point just below the entrance of the azygos vein. The other veins from the right lung gathered into two pulmonary veins and returned into the left atrium as usual. In the second case, which was found in an 80-year-old female Japanese, a connecting vein, approximately 8 mm in diameter, was found between the left superior pulmonary vein and the left brachiocephalic vein. In this case, although the direction of the blood flow within the connecting vein was not certain, it is probable that the blood passed from the pulmonary vein into the brachiocephalic vein, judging from the increase in the width of the latter vein. No other anomalies were found in the cardiovascular systems. At the occurrence of the anomalous drainage of the pulmonary veins in both cases, we suspected the role of the bronchial vein to be a communicating and boundary vein between the pulmonary and systemic circulations. The developmental background of these anomalies is also considered.

An anomalous muscle in the superficial region of the popliteal fossa, with special reference to its innervation and derivation.

An anomalous muscle was found in the superficial region of the right popliteal fossa in a 90-year-old Japanese female cadaver during dissection practice for medical students. The muscle ran transversely between the medial head of the gastrocnemius muscle and the tendon of the biceps femoris muscle, covering the nerves, vessels and muscle in the popliteal fossa. The muscle received its nerve supply from the common peroneal nerve. Based on the result of nerve fiber analysis, we speculated that the anomalous muscle might be close to the short head of the biceps femoris muscle in its derivation.