Biomedical subjects

Gen Murakami

Publications and source records attributed to Gen Murakami.

At least 37 records · Page 2Linked to original sources

PubMed2006

Distal fibular length needed for ankle stability.

BACKGROUND: The fibula is commonly used for bone grafts. Previous clinical and biomechanical studies have suggested that the length of the residual portion of the distal part of the fibula has an important effect on the long-term stability of the ankle joint. However, we cannot find clear-cut guidelines for the amount of bone that can be harvested safely. METHODS: Using six normal fresh-frozen cadaver legs, motions of the tibia, talus and calcaneus were measured. The fibula was cut sequentially 3 cm from the proximal tip of the fibula and distally 10 cm, 6 cm, and 4 cm from the distal tip of the lateral malleolus. The angular motion of each bone was measured while a medial and lateral traction force of 19.6 N was applied to the proximal tibia. Angles of the tibia, talus, and calcaneus were measured. RESULTS: Sequential resection of the fibula increased the inversion angles of the ankle joint. The proximal 3-cm cut increased the inversion angle from 42.1 +/- 6.2 degrees to 49.6 +/- 3.6 degrees, and the distal 4-cm cut increased the angle from 57.6 +/- 6.6 degrees to 67.4 +/- 5.9 degrees. The rotational angles were almost constant with sequential resections of the fibula; however, the distal 4-cm cut increased the rotational angle from 11.3 +/- 25.1 degrees to 78.7 +/- 37.5 degrees. CONCLUSIONS: The whole fibula including the head is essential for the stability of the ankle joint complex, and the distal fibula is responsible for stabilizing the ankle mortise during external rotation and inversion. We recommend fixation of the syndesmosis or bracing to prevent ankle joint instability with rotation of the talus in the mortise, especially when the distal fibula is shortened 6 cm or more.

Aged↗

PubMed2006

Capillary electrophoretic determination of self-dimerization constants of aromatic carboxylate and sulfonate ions.

Self-dimerizations of twenty three aromatic carboxylate and sulfonate ions from their electrophoretic mobilities in aqueous solution were estimated by capillary zone electrophoresis (CZE). The magnitudes of the self-dimerizations ascribed to pi-pi interactions of these aromatic anions were determined by CZE as dimerization constants (KD). Although the largest KD value of 1.2 dm3 mol(-1) for 9-anthracenecarboxylate ion (9-AC) in these aromatic anions was found, almost all of the KD values were zero, or near to zero. It was found that the pi-pi interactions of the aromatic anions were relatively small at zero ionic strength, in which the contribution of an ionic association between the cation and aromatic anions could be excluded from the KD values, since the contribution of the electric repulsion between the aromatic anions on the KD values was large. The relatively large KD value of 9-AC caused that it electro-migrates as its planar shape, and has an anthracene ring of a largely hydrophobic aromatic ring.

Journal Article↗

PubMed2006

D2-40 positive lymphatic endothelial cell density is much higher in and along the mammary glandular tissues than in subcutaneous tissue: case report of a 20-year-old donated female cadaver.

Sappey's demonstration of the breast lymphatic vessels, showing the presence of a subareolar lymphatic plexus and few thick vessels originating from the breast itself, is famous. However, with the exception of such studies performed by injection methods, to the best of our knowledge there has been no demonstration of the entire distribution of the breast lymphatic vessels. D2-40 immunohistochemistry of semiserial sections (at 0.1-mm intervals) taken from the healthy breast of a 20-year-old female cadaver revealed that the lymphatic endothelial density was much higher in and along the mammary glandular tissues than in the overlying subcutaneous and deep fascial tissues. Thus, the extent of the subareolar lymphatic plexus is likely to have been overestimated by the injection method. Instead, networks of lymphatic vessels around the mammary glands were evident in the physiological state.

Adult↗

PubMed2006

[Chemical content analysis of specimens of human head temporal portion commercially distributed for otological surgery lessons].

Specimens of the human head temporal portion are provided in the United States and distributed commercially for lessons in otological surgery via the internet. Many otologists have obtained and used these specimens in Japan. According to our chemical content analysis, these specimens were found to contain harmful substances as well as large molecule aldehydes and fatty acid methylesters, which are not or only rarely included in the human cadaveric specimens prepared in Japan. We discuss the suggested treatment of these imported specimens, how trial preparation of specimens are much better than the imported items, and the background of the rapid and wide distribution of the imported items in Japan.

Alcohols↗

PubMed2005

Estrogen induces rapid decrease in dendritic thorns of CA3 pyramidal neurons in adult male rat hippocampus.

Modulation of hippocampal synaptic plasticity by estrogen has been attracting much attention. Thorns of thorny excrescences of CA3 hippocampal neurons are post-synaptic regions whose presynaptic partners are mossy fiber terminals. Here we demonstrated the rapid effect of estradiol on the density of thorns of thorny excrescences, by imaging Lucifer Yellow-injected CA3 neurons in adult male rat hippocampal slices. The application of 1nM estradiol induced rapid decrease in the density of thorns on pyramidal neurons within 2h. The estradiol-mediated decrease in the density of thorns was blocked by CNQX (AMPA receptor antagonist) and PD98059 (MAP kinase inhibitor), but not by MK-801 (NMDA receptor antagonist). ERalpha agonist PPT induced the same suppressive effect as that induced by estradiol on the density of thorns, but ERbeta agonist DPN did not affect the density of thorns. Note that a 1nM estradiol treatment did not affect the density of spines in the stratum radiatum and stratum oriens. A search for synaptic ERalpha was performed using purified RC-19 antibody. The localization of ERalpha (67kDa) in the CA3 mossy fiber terminals and thorns was demonstrated using immunogold electron microscopy. These results imply that estradiol drives the signaling pathway including ERalpha and MAP kinase.

Aging↗

PubMed2005

Rapid spinogenesis of pyramidal neurons induced by activation of glucocorticoid receptors in adult male rat hippocampus.

Modulation of hippocampal synaptic plasticity by glucocorticoids has been attracting much attention, due to its importance in stress responses. Dendritic spines are essential for memory storage processes. Here, we investigated the effect of dexamethasone (DEX), a specific agonist of glucocorticoid receptor (GR), on density and morphology of dendritic spines in adult male rat hippocampus by imaging of Lucifer Yellow-injected spines in slices. The application of 100 nM DEX (stressful high concentration) induced rapid modulation of the density and morphology of dendritic spines in CA1 pyramidal neurons within 1h. The total spine density increased from 0.88 spines/microm (control) to 1.36 spines/microm (DEX-treated). DEX significantly increased the density of thin and mushroom type spines, however only a slight increase was observed for stubby and filopodium type spines. Because the presence of 10 microM cycloheximide, an inhibitor of protein synthesis, did not suppress the DEX effect, these responses are probably non-genomic. Western immunoblot analysis demonstrated the localization of classical type GR in Triton-insoluble synaptosomal fractions (enriched in postsynaptic membranes) from hippocampal slices, suggesting a possible action site of DEX at spines.

Animals↗

PubMed2005

Interindividual variation in distribution of extramural ganglion cells in the male pelvis: a semi-quantitative and immunohistochemical study concerning nerve-sparing pelvic surgery.

OBJECTIVE: We examined distribution and numbers of extramural ganglion cells in the male pelvis, classifying them as sympathetic or parasympathetic. METHODS: Specimens were obtained from 14 formalin-fixed donated male cadavers. Semiserial sections were processed for histologic examination, and for immunohistochemistry using anti-tyrosine hydroxylase (TH) or anti-peptide histidine isoleucine (PHI). RESULTS: Like those along the sacral sympathetic trunk, most other pelvic ganglion cells were located in and along nerve components. Yet the ganglion cell clusters attached to pelvic viscera accounted for 22% to 38% of ganglion cells. These were seen at the dorsal aspect of the bladder, the bladder/prostate junction, the dorsal aspect of the seminal vesicle, and along the prostate, but not along the extrapelvic pudendal nerve, cavernous tissues including the penile hilum, the rhabdosphincter, retropubic fat or recto-urethral muscle. Two fold interindividual variation was seen for total ganglion cell number (3044 to 6522) in the pelvis. TH-positive and PHI-positive cells intermingled at various ratio in every ganglion cell cluster. Sympathetic TH-positive proportions tended to be site-specific. CONCLUSIONS: Pelvic autonomic cells exist not only in nerve components but also along viscera. Even nerve-sparing radical prostatectomy can compromise visceral ganglia. Simple classification of pelvic nerve components as sympathetic or parasympathetic would seem misleading given coexistence of both cell types in a ganglion.

Aged↗

PubMed2005

Heterogeneity of subvesical ducts or the ducts of Luschka: a study using drip-infusion cholangiography-computed tomography in patients and cadaver specimens.

The objective of this study was to examine the heterogeneity of the subvesical duct or the ducts of Luschka as well as the reliability of drip-infusion cholangiography with computed tomography (DIC-CT) for their identification. DIC-CT was used in 277 consecutive patients (135 men, 142 women) and for the dissection and histologic study of 10 cadaver livers. We found 32 subvesical ducts in 28 (10.1%) of 277 patients. Irrespective of whether the terminals were extra- or intraparenchymal, the subvesical ducts often (17/32 ducts, 15/28 patients) drained into a subsegmental duct of S5 or S4. Notably, some displayed an "intermediate" course along the gallbladder fossa with an intraparenchymal origin and terminated at S5. Such ducts tended to be seen in the elderly. Another 15 ducts drained into a thick, centrally located duct, such as the right sectorial or hepatic duct. The anatomic study demonstrated that the subvesical duct likely included the cystic vein-concomitant duct. A major type of subvesical duct, characterized by an intermediate course along its bed, appeared to result from degenerative exposure of a peripheral duct with aging. The subvesical duct draining into the thick duct included both a "daughter branch," such as seen in the lung, and the so-called anomaly. Such ducts can be demonstrated with DIC-CT, but the incidence might be limited. However, the cystic vein/concomitant duct was difficult to identify radiologically. Consequently, although presurgical radiology is useful for avoiding bile leakage after laparoscopic cholecystectomy, surgeons should be aware of its limitations.

Adolescent↗

PubMed2005

Topographical histology of the posterolateral corner of the knee, with special reference to laminar configurations around the popliteus tendon: a study of elderly Japanese and late-stage fetuses.

We investigated the histology of laminar configurations at the posterolateral corners of 40 knees (18 late-stage fetuses, 22 elderly persons). In the fetuses, the deeply located popliteal fascia and the superficially located inferior geniculate vascular sheath were evident in a space between the popliteus tendon (PT) and the biceps femoris and gastrocnemius. Along, and deep to, the popliteal fascia, the popliteus muscle parenchyma developed into both the PT and another dense connective tissue mass. The PT attached to the fibula (i.e., the fetal popliteofibular ligament) and to the base of the lateral meniscus (i.e., the fetal popliteomeniscal fasciculus). This laminar configuration was essentially maintained in the elderly. The fetal dense connective tissue of the popliteus origin seemed to correspond to the adult arcuate ligament. However, because a connective tissue complex (including the PT and the arcuate and popliteofibular ligaments) was often well developed, the complex involved the inferior geniculate vascular sheath and popliteal fascia. A spectrum of variations was found in how thickly the complex developed. Thus, clear separation of the PT from the surrounding tissues often became difficult. Notably, the connective tissue complex could be peeled in different manners, depending on the site and the individual. Therefore, macroscopic variation in the posterolateral corner, including the apparent absence of some ligaments, seemed to be related to the thickness and number of layers developed by the connective tissue complex, possibly due to an adaptation to the individual's mechanical environment during growth and aging.

Aged↗

PubMed2005

Discrepancies between classic anatomy and modern gynecologic surgery on pelvic connective tissue structure: harmonization of those concepts by collaborative cadaver dissection.

OBJECTIVE: The purpose of this study was to solve a disagreement regarding the anatomy of the pelvic connective tissue in 19th and 20th century, and to establish new surgical anatomy. STUDY DESIGN: The study involved the dissection 26 female cadavers. The ligamentous structure of the pelvis was examined by developing the paravesical and pararectal spaces, using our standard procedure of radical hysterectomy. RESULTS: The lateral ligamentous structure of the pelvis was a plate complex, which consisted of the vesicohypogastric fascia, the transverse cervical ligament, and lateral ligament of the rectum. The 3-dimensional relationship of this complex and the pelvic organs was sagittaly perpendicular. The pelvic connective tissue was classified into 2 systems, musculofascial and mesentery-like structures. CONCLUSION: The authors examined the discrepancies in 19th century anatomy for the pelvic connective tissue that is widely accepted in today's medical field, therewith proposing a new surgical anatomy for this structure.

Aged↗

PubMed2005

Variation in course of cavernous nerve with special reference to details of topographic relationships near prostatic apex: histologic study using male cadavers.

OBJECTIVES: To study interindividual variation in the cavernous nerve course near the rhabdosphincter and the apex of the prostate as a basis for refining nerve-sparing radical prostatectomy. The varying anatomy of the cavernous nerve might account for the disparate potency rates after nerve-sparing radical prostatectomy. METHODS: We examined serial histologic sections from 20 male pelves (7 frontal, 8 sagittal, and 5 axial sections) and performed 5 fresh cadaver dissections. RESULTS: In the fresh dissections, the macroscopically identified neurovascular bundle consistently showed an almost straight proximal-to-distal course along the urethra. However, on histologic analysis, the types of the nerve course were classified as frontal (2 of 7 specimens), sagittal (3 of 8), and axial (2 of 5). In the frontal and sagittal courses, the nerves passed through the connective tissue of a narrow potential space between the rhabdosphincter and the levator ani. In the specimens showing an axial course, the nerves were spatially distinct from the prostate, coursing ventromedially in the pararectal space. Thus, the nerves could display a long, tortuous course, passing through the rectourethral muscle at its thickest portion. In addition, a nerve component supplying the area of the rhabdosphincter seemed to accompany the cavernous nerve. CONCLUSIONS: The neurovascular bundle, previously defined in terms of surgery, is likely to differ from the actual course of the cavernous nerve when this is axial, passing through the pararectal space and rectourethral muscle. To avoid cavernous nerve injury, the rectourethral muscle must be managed carefully in both the retropubic and the perineal approaches.

Aged↗

PubMed2005

Anatomy and histology of Virchow's node.

A regional lymphatic system is composed of the first, second, third and even fourth or much more intercalated nodes along the lymptatic route from the periphery to the venous angle or the thoracic duct. The third or fourth node is usually termed the last-intercalated node or end node along the route. Similarly, one of the supraclavicular nodes is known to correspond to the end node along the thoracic duct. It is generally called 'Virchow's node', in which the famous 'Virchow's metastasis' of advanced gastric cancer occurs. The histology of this node has not been investigated, although region-specific differences in histology are evident in human lymph nodes. We found macroscopically the end node in five of 30 donated cadavers. Serial sections were prepared for these five nodes and sections stained with hematoxylin and eosin. Histological investigation revealed that, on the inferior or distal side of the end node, the thoracic duct divided into three to 10 collateral ducts and these ducts surrounded the node. The node communicated with the thoracic duct and its collaterals at multiple sites in two to three hilus-like portions, as well as along the subcapsular sinus. Thus, the end node was aligned parallel to the thoracic duct. Moreover, the superficial and deep cortex areas of the end node were fragmented to make an island-like arrangement, which may cause the short-cut intranodal shunt. Consequenly, the filtration function of most of Virchow's node seemed to be quite limited.

Cadaver↗

PubMed2005

A novel technique for approaching the endopelvic fascia in retropubic radical prostatectomy, based on an anatomical study of fixed and fresh cadavers.

OBJECTIVE: To present the anatomical basis and details of a technique for an approach to the endopelvic fascia devised to preserve urinary continence. PATIENTS, MATERIALS AND METHODS: For cross-sectional macroscopic observation, seven formalin-fixed specimens of the male pelvic contents including the pelvic wall were serially sectioned at a 5-mm thickness. Semi-serial sections from eight other specimens were examined histologically. Eight fresh cadavers were dissected to mimic the various steps in a retropubic radical prostatectomy. After approaching the endopelvic fascia in an anatomically determined manner to reach the paraprostatic space, the pubic bone was removed and nerves near the rhabdosphincter dissected. To assess the clinical implication of this approach, we examined the time to achieve continence in 23 consecutive patients who had a radical retropubic prostatectomy using the new technique. RESULTS: Sectional macroscopic observation depicted the fascia of the levator ani as a definite structure adherent to but not fused with the lateral pelvic fascia. The thin fascia overlying the levator ani fascia and lateral pelvic fascia represented the true endopelvic fascia. Microscopically, the lower part of the fascia of the levator ani was rich in smooth muscle, which interdigitated with the framework of the rhabdosphincter. In fresh cadavers, the levator ani muscle was removed laterally still covered by its fascia, without visualizing the muscle fibres. Small branches from the pudendal nerve entered the rhabdosphincter. The mean (sd, range) distance from the lowest point of the endopelvic fascia to the point where the sphincteric branch entered the rhabdosphincter was 5.5 (1.8, 3-8) mm. The continence rate at 1, 3, 6 and 9 months after surgery using the new technique was 44%, 83%, 96% and 100%, respectively. CONCLUSIONS: Preserving the fascia of the levator ani helps to protect the levator ani muscle, rhabdosphincter and pudendal nerve branches to the rhabdosphincter. In retropubic radical prostatectomy, this anatomical approach to the endopelvic fascia should preserve or allow the earlier recovery of urinary continence.

Aged↗

PubMed2005

Strain on the ulnar nerve at the elbow and wrist during throwing motion.

BACKGROUND: It is well known that cubital tunnel syndrome frequently occurs in throwing athletes. The cause of cubital tunnel syndrome is considered to be mechanical stimuli on the ulnar nerve in the cubital tunnel. The hypothesis of the present cadaveric study was that the ulnar nerve is subjected to longitudinal strain in the cubital tunnel during the throwing motion. METHODS: Four phases of throwing (stance, wind-up, middle cock-up, and early acceleration) were passively simulated in seven fresh-frozen transthoracic cadaveric specimens that were fixed in an upright position to allow free arm movement. In each throwing phase, the elbow was sequentially flexed from 45 degrees to 90 degrees to 120 degrees to maximum flexion. The longitudinal movement of and strain on the ulnar nerve were measured with use of a caliper and a strain gauge at the proximal aspects of both the cubital tunnel and the canal of Guyon. RESULTS: The movement of the ulnar nerve at the proximal aspect of the cubital tunnel was significantly increased during all throwing phases with increased elbow flexion (p < 0.05). An average maximum movement of 12.4 +/- 2.4 mm was recorded during the wind-up phase with maximum elbow flexion. The movement at the proximal aspect of the canal of Guyon was approximately two-thirds of that at the proximal aspect of the cubital tunnel. The strain on the ulnar nerve at the proximal aspect of the cubital tunnel was significantly increased with elbow flexion in the stance, wind-up, and middle cock-up phases (p < 0.05). An average maximum strain of 13.1% +/- 6.1% was recorded during the early acceleration phase with maximum elbow flexion. The strain at the proximal aspect of the canal of Guyon was approximately half of that at the proximal aspect of the cubital tunnel. CONCLUSIONS: In the present study, the maximum strain on the ulnar nerve during the acceleration phase was found to be close to the elastic and circulatory limits of the nerve.

Aged↗

PubMed2005

[Researches of clinical anatomy performed by experienced surgeons and physicians coming from outside of the university].

These 5 years, twenty experienced surgeons and physicians have come from outside of the university and performed researches of clinical anatomy in my laboratory. This report shows the specific research preparation, actual research life and related problems. I hope it will provide a new, fruiteful collaboration between the present author and other members of JAA.

Anatomy↗

PubMed2004

Are difficulties during transbronchial lung biopsy/brushing through a fiberoptic bronchoscope based on the bronchial anatomy?

Some of the difficulties encountered during transbronchial lung biopsy through a flexible bronchofiberscope are due to anatomical reasons, namely the branching angles of some subsegmental bronchi from their mother bronchi are large, and differences in branching angles during respiration may also be large. This makes insertion of forceps difficult. We have sometimes experienced difficulties reaching the target lesion during a transbronchial approach. Which subsegmental bronchi make transbronchial lung biopsy/brushing difficult, and are such difficulties due to anatomical reasons? To answer these questions, we firstly surveyed 10 bronchologists regarding which five subsegmental bronchi they considered to be the most difficult for transbronchial biopsy/brushing. We then measured the branching angles of subsegmental bronchi in 106 cadaver lungs. Finally, in six volunteers, we also measured differences in branching angles of the subsegmental bronchi between the point of forced inspiration and the point of forced expiration on CT images. According to the survey, left B(1+2)c was considered to be the most difficult for insertion by nine doctors, followed by bilateral B6a by seven, right B1a by five, left B3a by five and left B(1+2)a by four. The results of our dissections showed that a branching angle of over 60 masculine was present in more than 10% of specimens in B3a, B6a and B6c in the right lung and in B(1+2)c, B3a, B6a and B6c in the left lung. In addition, three-dimensional reconstructed images revealed that the angles of some subsegmental bronchi changed during respiration. Inter-individual variations were present in most subsegmental bronchi. The direction of movement of each subsegmental bronchus during respiration varied. In addition, maximum degrees of difference in angles between volunteers were sometimes as much as 80 degrees . In conclusion, branching angles of subsegmental bronchi from their mother bronchi are large in B3a, B6a and B6c in the right lung and in B(1+2)c, B3a, B6a and B6c in the left lung. Most of these correspond to those which many bronchologists felt to be difficult for insertion. In addition, changes in the angles of subsegmental bronchi during respiration are likely to partially account for difficulties encountered during transbronchial approaches.

Aged↗

PubMed2004

Spiegel's lobe bile ducts often drain into the right hepatic duct or its branches: study using drip-infusion cholangiography-computed tomography in 179 consecutive patients.

Using drip-infusion cholangiography-computed tomography (DIC-CT), we successfully identified the bile ducts draining the caudate lobe in 138 of 179 consecutive patients with extrahepatic cholelithiasis (179 ducts from Spiegel's lobe and 154 from the paracaval portion; 1-5 ducts per patient). The dorsal subsegmental duct of S8 (B8c) was often identified and could be discriminated from the paracaval caudate ducts, thus acting as a landmark for the right margin of the caudate lobe. Notably, in more than one-third of the 138 patients, at least one of the Spiegel's lobe ducts drained into the right hepatic duct or its branches (30.2% of the 179 ducts overall; all ducts joined branches of the right lobe in 25 patients). Similarly, 34.4% of the 154 paracaval caudate lobe ducts drained into the left hepatic duct or its branches. These "anatomical left/right dissociations" between the drainage territory and route were much more frequent than previously reported. Our results confirm the effectiveness of DIC-CT as a classical, noninvasive method for presurgical evaluation of the biliary system, but they also suggest that anatomical partial resection of the dorsal liver in patients with hilar cholangioma is often impossible because of contralateral biliary drainage.

Adolescent↗

PubMed2004

Lack of the complete circular rhabdosphincter and a distinct circular smooth muscle layer around the proximal urethra in elderly Japanese women: an anatomical study.

Histological observations of semiserial sections obtained from the cadavers of 30 elderly Japanese women (aged 61-93 years) found that the urethral rhabdosphincter (URS) usually occurred as a ventrally localized structure instead of exhibiting the normal completely circular configuration. The superoinferior length, thickness and muscle fiber density of the URS area showed significant interindividual variation. A thick fascicle, extending posterolaterally from the URS and radiating to the lateral vaginal wall and other perineal tissues, was usually observed. A circular smooth muscle layer, which immediately surrounded the longitudinal smooth muscle layer, was consistently present in the proximal urethral but not in the bladder neck. These findings suggest that voluntary sphincteric action is weak or incomplete in elderly Japanese women. We therefore hypothesize that upward retraction of the midurethra by the URS, compression of the distal urethra by its posterolateral extensions, and tonus provided by the outer circular smooth muscle layer all contribute to maintaining continence in these women.

Aged↗