Cilostazol improves the prognosis after hepatectomy in rats with sinusoidal obstruction syndrome.

BACKGROUND AND AIM: Safe radical hepatectomy is important for patients with colorectal liver metastases complicated by sinusoidal obstruction syndrome (SOS) after oxaliplatin-based chemotherapy. This study aimed to investigate the impact of preoperative administration of cilostazol (CZ), an oral selective phosphodiesterase III inhibitor, on hepatectomy in rat SOS model. MATERIAL AND METHODS: Rats were divided into NL (normal liver), SOS (monocrotaline [MCT]-treated), and SOS + CZ (MCT + CZ-treated) groups. MCT or CZ was administered orally, and a 30% partial hepatectomy was performed 48 h after MCT administration. Postoperative survival rates were evaluated (n = 9, for each). Other rats were sacrificed on postoperative days (POD) 1 and 3 and evaluated histologically, immunohistochemically, biochemically, and using transmission electron microscopy (TEM), focusing particularly on SOS findings, liver damage, and liver sinusoidal endothelial cell (LSEC) injury. RESULTS: The cumulative 10-day postoperative survival rate was significantly higher in the SOS + CZ group than in the SOS group (88.9% vs 33.3%, P = 0.001). Total SOS scores were significantly lower in the SOS + CZ group than in the SOS group on both POD 1 and 3. Serum biochemistry and immunohistochemistry showed that CZ reduced liver damage after hepatectomy. TEM revealed that LSECs were significantly preserved morphologically in the SOS + CZ group than in the SOS group on POD 1 (86.1 ± 8.2% vs 63.8 ± 9.3%, P = 0.003). CONCLUSION: Preoperative CZ administration reduced liver injury by protecting LSECs and improved the prognosis after hepatectomy in rats with SOS.

Combined Experiments with in Vivo Fiber Photometry and Behavior Tests Can Facilitate the Measurement of Neuronal Activity in the Primary Somatosensory Cortex and Hyperalgesia in an Inflammatory Pain Mice Model.

The pain matrix, which includes several brain regions that respond to pain sensation, contribute to the development of chronic pain. Thus, it is essential to understand the mechanism of causing chronic pain in the pain matrix such as anterior cingulate (ACC), or primary somatosensory (S1) cortex. Recently, combined experiment with the behavior tests and in vivo calcium imaging using fiber photometry revealed the interaction between the neuronal function in deep brain regions of the pain matrix including ACC and the phenotype of chronic pain. However, it remains unclear whether this combined experiment can identify the interaction between neuronal activity in S1, which receive pain sensation, and pain behaviors such as hyperalgesia or allodynia. In this study, to examine whether the interaction between change of neuronal activity in S1 and hyperalgesia in hind paw before and after causing inflammatory pain was detected from same animal, the combined experiment of in vivo fiber photometry system and von Frey hairs test was applied. This combined experiment detected that amplitude of calcium responses in S1 neurons increased and the mechanical threshold of hind paw decreased from same animals which have an inflammatory pain. Moreover, we found that the values between amplitude of calcium responses and mechanical thresholds were shifted to negative correlation after causing inflammatory pain. Thus, the combined experiment with fiber photometry and the behavior tests has a possibility that can simultaneously consider the interaction between neuronal activity in pain matrix and pain induced behaviors and the effects of analgesics or pain treatments.

Differences in the microstructural and mechanical qualities of semitendinosus tendon grafts between skeletally immature and mature patients in anterior cruciate ligament reconstruction.

BACKGROUND: This study aimed to investigate the microstructural and mechanical properties of semitendinosus tendon graft tissues during anterior cruciate ligament reconstruction and the clinical outcomes in skeletally immature and mature patients. METHODS: Twenty-two patients who underwent primary anterior cruciate ligament reconstruction using a hamstring tendon graft were analyzed and divided into skeletally immature (n = 7) and mature groups (n = 15) based on magnetic resonance imaging findings of the epiphyseal plate of the distal femur. Tissue samples were collected from the mid-portion of the semitendinosus tendon. The collagen fibril diameter, maximum stress, and strain at maximum stress point in the semitendinosus tendon tissues were calculated for comparison of the microstructural and mechanical properties between the two groups. Postoperative outcomes were also assessed between the two groups. RESULTS: The mean and 60th and 80th percentiles of fibril diameters in the skeletally immature group were significantly smaller than those in the mature group (65.9 ± 13.0, 73.5 ± 19.3, and 91.3 ± 27.4 nm in the skeletally immature group; and 90.3 ± 14.7, 94.0 ± 18.4, and 125.3 ± 19.9 nm in the skeletally immature group; p = 0.001, 0.024, and 0.004, respectively). Additionally, the strain at maximum stress was higher in the skeletally immature group (237.2 ± 102.4% vs. 121.5 ± 51.9%, p = 0.024). However, there was no difference in maximum stress between the skeletally immature and mature groups (19.9 ± 14.3 MPa vs. 24.5 ± 23.4 MPa, p = 0.578). Strain was negatively correlated with the mean fibril diameter and the 60th and 80th percentiles of fibril diameters, whereas stress was positively correlated with the mean fibril diameter. The skeletally immature group had a higher pivot shift test-positive rate than the mature group at the last follow-up (p = 0.023). CONCLUSION: Semitendinosus tendon graft tissues differed microstructurally and mechanically between skeletally immature and mature patients. LEVEL OF EVIDENCE: Level Ⅳ.

Hedgehog signaling plays a crucial role in hyperalgesia associated with neuropathic pain in mice.

Neuropathic pain is a debilitating chronic syndrome of the nervous system caused by nerve injury. In Drosophila, the Hedgehog (Hh) signaling pathway is related to increased pain sensitivity (hyperalgesia) but does not affect the baseline nociceptive threshold. In general, the contribution of the Hh signaling pathway to neuropathic pain in vertebrates is a highly debated issue. Alternatively, we investigated the potential role of Hh signaling in mechanical allodynia using a mouse model of neuropathic pain. Seven days after spinal nerve-transection (SNT) surgery, microglial activation increased in the ipsilateral spinal dorsal horn compared with that in the sham group; however, 21 days after surgery, microglial activation decreased. Contrastingly, astrocyte activation in the spinal cord did not differ between the groups. On day 21 of postsurgery, the SNT group showed marked upregulation of sonic hedgehog expression in peripheral glial cells but not in dorsal root ganglion (DRG) neurons. Intrathecal administration of the Hh signaling inhibitor vismodegib attenuated the mechanical allodynia observed on day 21 postsurgery. Conversely, intrathecal treatment with the Hh signaling activator smoothened agonist in naive mice induced mechanical allodynia, which was abolished by the ATP transporter inhibitor clodronate. Moreover, inhibition of Hh signaling by pretreatment with vismodegib significantly reduced ATP secretion and the frequency/number of spontaneous elevations of intracellular calcium ion levels in cultured DRG cells. Thus, the Hh signaling pathway appears to modulate the neural activity of DRG neurons via ATP release, and it plays an important role in sustaining mechanical allodynia and hypersensitivity in a mouse model of neuropathic pain.

A Fiber Dissection Study of the Anterior Commissure: Correlations with Diffusion Spectrum Imaging Tractography and Clinical Relevance in Gliomas.

The anterior commissure, which connects bilateral temporal lobes and olfactive areas, remains elusive in many aspects of its structure and functional role. To comparatively describe anatomical details of the anterior commissure using cadaveric fiber dissection (FD) and diffusion spectrum imaging (DSI) thus refining our knowledge of the tract and exploring its clinical relevance in glioma migration. Twelve normal postmortem hemispheres were treated with Klingler's method and subjected to FD with medial, inferior, and lateral approaches. The FD findings were correlated with DSI tractography results. To illustrate the clinical relevance, two patients with recurrent temporal high-grade glioma are described. Our FD and DSI tractography of the anterior commissure disclosed a new anatomical paradigm. The FD confirmed that the anterior limb (absent sometimes and variable) and the lateral/temporal extension include the rostral portion and caudal portion, respectively, of the anterior commissure fibers. The shape of the lateral/temporal extension predominantly resembles an 'H'. The DSI tractography findings corresponded to these FD results. According to the FD, the Virchow-Robin space is continuous with the subarachnoid space and very close to the anterior commissure. The two clinical cases presented severe disturbances of consciousness and behavior despite good local tumor control. Subsequent magnetic resonance images showed new lesions infiltrating the contralateral temporal lobes. FD combined with DSI provided anatomical details facilitating a better understanding of the anterior commissure. Glioma migration routes to the contralateral temporal lobe included the anterior commissure, Virchow-Robin space, and subarachnoid space and were clinically relevant.

Differences in cellular and microstructural properties of the semitendinosus muscle tendon between young and adult patients.

BACKGROUND: Poor outcomes associated with anterior cruciate ligament reconstruction in paediatric patients are a major concern. The tendon structure and its cellular characteristics are key factors that affect the mechanical properties of tendons. This study aimed to evaluate the effects of growth on the cellular and microstructural properties of the tendon of the semitendinosus muscle in humans. METHODS: Semitendinosus muscle tendon samples from 76 patients who underwent ligament reconstruction were examined and divided into three groups: immature (10.8 ± 2.7 years old), young (16.5 ± 1.8 years old), and adult (35.2 ± 8.6 years old), based on age and the state of the epiphyseal plate in the distal femur. The number of tendon cells per unit area was assessed, and the major-to-minor-length ratio of the tendon cell nuclei was calculated to evaluate the shape of the nuclei using haematoxylin and eosin staining. The collagen fibril diameter and distribution were determined using electron microscopy. RESULTS: The major-to-minor-length ratio of the tendon cell nuclei significantly increased with age (p-value; immature vs. young: 0.018, young vs adult: 0.001, immature vs adult: 0.001). The shape of the tendon cell nuclei was rounder in the immature group and more elongated in the adult group. A significant decrease in the number of tendon cells was observed with age (immature: 565 ± 134/mm2, young: 356 ± 105/mm2, adult: 272 ± 81/mm2; p-value: immature vs young: 0.001, young vs adult: 0.012, immature vs adult: 0.001). The mean fibril diameter in the immature group was significantly smaller (p-value: immature vs young: 0.018, young vs adult: 0.001, immature vs adult: 0.001). The distribution of the collagen fibrils changed from right skewed in the immature group to flat in the adult group. CONCLUSIONS: The characteristics of the tendon cells and the microstructure of collagen in muscle tendons significantly changed with age.

Comparison of each bundle of the spring ligament complex between the standing and supine positions: A multiposture magnetic resonance imaging study.

BACKGROUND: The spring ligament complex (SLC) supports the medial longitudinal arch of the foot, particularly in standing. We evaluated posture-related changes in the thickness and length of the three SLC bundles and their histology. METHODS: The thickness and length of the supramedial calcaneonavicular ligament (smCNL), medioplantar oblique calcaneonavicular ligament (mpoCNL), and inferoplantar calcaneonavicular ligament (iplCNL) were measured in the supine and standing positions, using a multiposture magnetic resonance imaging system, in 72 healthy adult feet. Histological examination was performed for 10 feet from five cadavers. RESULTS: The smCNL thickness decreased and its length increased from the supine to the standing position (P < 0.001); no other posture-related effects were noted. Histologically, smCNL fibers overlapped along multiple directions while mpoCNL and iplCNL, fibers were oriented horizontally along the longitudinal axis and vertically along the short axis, respectively. CONCLUSION: The complex, multidirectional, orientation of the smCNL allows an adaptive response to changes in loading.

Pyramid-Shape Crossings and Intercrossing Fibers Are Key Elements for Construction of the Neural Network in the Superficial White Matter of the Human Cerebrum.

Structural analysis of the superficial white matter is prerequisite for the understanding of highly integrated functions of the human cerebral cortex. However, the principal components, U-fibers, have been regarded as simple wires to connect adjacent gyri (inter-gyral U-fibers) but have never been thought as indispensable elements of anatomical structures to construct the cortical network. Here, we reported such novel structures made of U-fibers. Seven human cerebral hemispheres were treated with Klingler's method and subjected to fiber dissection (FD). Additionally, tractography using diffusion spectrum imaging (DSI) was performed. Our FD and DSI tractography succeeded disclosing a new type of U-fibers that was hidden in and ran along the white matter ridge of a gyral convolution (intra-gyral U-fibers). They were distinct from inter-gyral U-fibers which paved sulcal floors. Both intra- and inter-gyral U-fibers converged from various directions into junctional areas of white matter ridges, organizing novel anatomical structures, "pyramid-shape crossings". U-fibers to form pyramid-shape crossings also render routes for communication between crossings. There were 97 (mean, range 73-148) pyramid-shape crossings per lateral cortical surface. They are key structures to construct the neural network for intricate communications throughout the entire cerebrum. They can be new anatomical landmarks, too, for the segmentation of the cerebral cortex.

Responsiveness of lumbosacral superficial dorsal horn neurons during the voiding reflex and functional loss of spinal urethral-responsive neurons in streptozotocin-induced diabetic rats.

AIMS: Sensory information from the lower urinary tract (LUT) is conveyed to the spinal cord to trigger and co-ordinate micturition. However, it is not fully understood how spinal dorsal horn neurons are excited during the voiding reflex. In this study, we developed an in vivo technique allowing recording of superficial dorsal horn (SDH) neurons concurrent with intravesical pressure (IVP) during the micturition cycle in both normal and diabetic rats. METHODS: Lumbosacral dorsal horn neuronal activity and IVP were recorded from urethane-anesthetized naive and streptozotocin (STZ)-induced diabetic rats. Saline was continuously perfused into the urinary bladder through a cannula to induce micturition. RESULTS: We classified SDH neurons into bladder- and urethral-responsive neurons, based on their responsiveness during the voiding reflex. Bladder-responsive SDH neurons responded to the rapid increase in IVP at the start of voiding. In contrast, urethral-responsive SDH neuronal firing increased at the peak IVP and their firing lasted during the voiding phase (the high-frequency oscillations). Urethral-responsive SDH neurons were more sensitive to capsaicin, received C afferent fiber inputs, and were rarely detected in STZ-diabetes rats. Administration of a cyclohexenoic long-chain fatty alcohol (TAC-302), which is reported to promote neurite outgrowth of peripheral nerves in STZ-diabetic rats, prevented the functional loss of spinal urethral response. CONCLUSIONS: Sensory information from the bladder and urethra is conveyed separately to different groups of SDH neurons. Functional loss of spinal urethral sensory information through unmyelinated C afferent fibers may contribute to diabetic bladder dysfunction.

The role of peripheral corticotropin-releasing factor signaling in a rat model of stress-induced gastric hyperalgesia.

BACKGROUND: Functional dyspepsia (FD) is a common gastrointestinal disorder associated with persistent or recurrent upper gastrointestinal tract symptoms such as pain without any obvious pathological changes. Psychological and psychiatric factors might have a pathogenic role in FD. Changes in the sensation of stomach pain were determined after application of stress to adult rats. The involvement of corticotropin-releasing factor (CRF), Type 2 CRF receptor (CRF2) and inflammatory cytokine interleukin-6 (IL-6) was also investigated in the gastric hyperalgesia observed in this model. RESULTS: Repeated water avoidance stress (WA-S) produced gastric hyperalgesia, with no obvious lesions in the gastric mucosa. Gastric hyperalgesia was inhibited by CRF and CRF2 antagonists, suggesting their involvement in gastric hyperalgesia observed after application of stress. Gastric hyperalgesia was inhibited by IL-6 neutralizing antibody. Immunofluorescence staining demonstrated CRF, CRF2, urocortin (Ucn)1, and Ucn2-positive cells in the gastric mucosa. CRF2-positive cells increased after WA-S, compared to sham stress. CRF2 and Ucn2 were expressed in the mast cells in the gastric mucosa. CONCLUSIONS: CRF2 plays an important role in gastric hyperalgesia produced by stress. CRF2 signaling may be a useful therapeutic target for functional dyspepsia.

CCR2 upregulation in DRG neurons plays a crucial role in gastric hyperalgesia associated with diabetic gastropathy.

Background Diabetic gastropathy is a complex neuromuscular dysfunction of the stomach that commonly occurs in diabetes mellitus. Diabetic patients often present with upper gastrointestinal symptoms, such as epigastric discomfort or pain. The aim of this study was to assess gastric sensation in streptozocin-induced diabetes mellitus (DM) rats and to determine the contribution of C-C motif chemokine receptor 2 (CCR2) signaling to gastric hyperalgesia. Results DM rats showed signs of neuropathy (cutaneous mechanical hyperalgesia) from two weeks after streptozocin administration until the end of the experiment. Accelerated solid gastric emptying was observed at two weeks after streptozocin administration compared to the controls. Intense gastric hyperalgesia also developed in DM rats at two weeks after streptozocin administration, which was significantly reduced after intrathecal administration of the CCR2 antagonist INCB3344. Immunochemical analysis indicated that CCR2 expression was substantially upregulated in small and medium-sized dorsal root ganglia neurons of DM rats, although the protein level of monocyte chemoattractant protein-1, the preferred ligand for CCR2, was not significantly different between the control and DM groups. Conclusions These data suggest that CCR2 activation in nociceptive dorsal root ganglia neurons plays a role in the pathogenesis of gastric hyperalgesia associated with diabetic gastropathy and that CCR2 antagonist may be a promising treatment for therapeutic intervention.

CD38 positively regulates postnatal development of astrocytes cell-autonomously and oligodendrocytes non-cell-autonomously.

Glial development is critical for the function of the central nervous system. CD38 is a multifunctional molecule with ADP-ribosyl cyclase activity. While critical roles of CD38 in the adult brain such as oxytocin release and social behavior have been reported, those in the developing brain remain largely unknown. Here we demonstrate that deletion of Cd38 leads to impaired development of astrocytes and oligodendrocytes in mice. CD38 is highly expressed in the developing brains between postnatal day 14 (P14) and day 28 (P28). In situ hybridization and FACS analysis revealed that CD38 is expressed predominantly in astrocytes in these periods. Analyses of the cortex of Cd38 knockout (Cd38-/- ) mice revealed delayed development of astrocytes and subsequently delayed differentiation of oligodendrocytes (OLs) at postnatal stages. In vitro experiments using primary OL cultures, mixed glial cultures, and astrocytic conditioned medium showed that astrocytic CD38 regulates the development of astrocytes in a cell-autonomous manner and the differentiation of OLs in a non-cell-autonomous manner. Further experiments revealed that connexin43 (Cx43) in astrocytes plays a promotive role for CD38-mediated OL differentiation. Finally, increased levels of NAD+ , caused by CD38 deficiency, are likely to be responsible for the suppression of astrocytic Cx43 expression and OL differentiation. Our data indicate that CD38 is a positive regulator of astrocyte and OL development.

Atrophy of submandibular gland by the duct ligation and a blockade of SP receptor in rats.

To clarify the mechanisms underlying the submandibular gland atrophies associated with ptyalolithiasis, morphological changes were examined in the rat submandibular gland following either surgical intervention of the duct or functional blockade at substance P receptors (SPRs). Progressive acinar atrophy was observed after duct ligation or avulsion of periductal tissues. This suggested that damage to periductal tissue involving nerve fibers might contribute to ligation-associated acinar atrophy. Immunohistochemically labeled-substance P positive nerve fibers (SPFs) coursed in parallel with the main duct and were distributed around the interlobular, striated, granular and intercalated duct, and glandular acini. Strong SPR immunoreactivity was observed in the duct. Injection into the submandibular gland of a SPR antagonist induced marked acinar atrophy. The results revealed that disturbance of SPFs and SPRs might be involved in the atrophy of the submandibular gland associated with ptyalolithiasis.

Involvement of glial activation in trigeminal ganglion in a rat model of lower gingival cancer pain.

Glial cells were investigated to elucidate their involvement in mechanisms underlying oral cancer pain. Squamous cell carcinoma (SCC-158) was inoculated into the lower gingiva of male Fisher rats. Pharmacological and immunohistochemical studies were performed to examine the roles played by TRPV1 and TRPV2 expressed in neurons and satellite glia in trigeminal ganglia (TG), and microglia and astrocytes in trigeminal spinal nucleus caudalis. Inoculation of SCC-158 into the lower gingiva induced marked mechanical allodynia in the whisker-pad skin area on days 16 through 28, and in the submandibular skin area on days 10 through 20. Cutaneous allodynia was diminished by systemic morphine administration. The number of TRPV1 and TRPV2-positive neurons in trigeminal ganglia increased in the medium and large cell groups on day 14 after tumor inoculation. The number of satellite glial cells encircling the medium and large trigeminal ganglion neurons increased on day 28 after tumor inoculation. In this gingival cancer pain model, microglia and astrocytes in trigeminal spinal nucleus caudalis were not activated, although they were reported to be activated in neuropathic and inflammatory pain models. These results suggest that TRPV1 and TRPV2 upregulation in trigeminal ganglion neurons may play an important role in inducing the mechanical allodynia observed in experimental models of oral squamous cell carcinoma. In addition, activation of satellite cells seems to be involved in the maintenance of mechanical allodynia, which could be the potential therapeutic target for oral cancer pain.

Distinct subdivisions of subcortical U-fiber regions in the gyrencephalic ferret brain.

The human cerebrum contains a large amount of cortico-cortical association fibers. Among them, U-fibers are short-range association fibers located in white matter immediately deep to gray matter. Although U-fibers are thought to be crucial for higher cognitive functions, the organization within U-fiber regions are still unclear. Here we investigated the properties of U-fiber regions in the ferret cerebrum using neurochemical, neuronal tracing, immunohistochemical and electron microscopic techniques. We found that U-fiber regions can be subdivided into two regions, which we named outer and inner U-fiber regions. We further uncovered that outer U-fiber regions have smaller-diameter axons with thinner myelin compared with inner U-fiber regions. These findings may indicate functional complexity within U-fiber regions in the cerebrum.

Multiple factors contribute to flight behaviors during fear conditioning.

Shifting defensive mode from one to another by the imminence of threat is crucial for survival. The transition of defensive mode from freezing to flight is observed during the modified fear conditioning, however, the flight during fear conditioning is not well characterized. To characterize the flight behaviors during the fear conditioning, we conducted experiments in male mice focusing on the influence of the context, the intensity of the unconditioned stimulus and conditioned stimulus (CS), the schedule of conditioning, and the state of the subject. Flight behaviors triggered by salient CS showed characteristics of fear-potentiated defensive behaviors depending on the conditioned context, while repetitive conditioning enhanced the expression of the flight and developed an association between the CS and the flight. The salient auditory stimulus was the primary factor to trigger flight behaviors. Also, the spaced conditioning increased the expression of flight behaviors. Taken together, the flight behavior during fear conditioning is not a simple conditioned response nor simple fear-potentiated behavior, but a complicated mixture of multiple components of defensive behaviors. The transition of defensive mode could be induced by the integration of multiple innate and learned components of fear or anxiety.

Pain-related neuronal ensembles in the primary somatosensory cortex contribute to hyperalgesia and anxiety.

The mechanism by which acute pain or itch information at the periphery is processed in the primary somatosensory cortex (S1) remains unclear. To elucidate this, we used a viral-mediated targeted-recombination-in-active population system to target S1 neuronal ensembles that are active during pain or itch sensations. We induced the expression of excitatory or inhibitory designer receptors exclusively activated by designer drugs in pain- or itch-related S1 neurons. We identified neuronal populations in mice that regulate the sensory components of pain and itch in the S1 hind paw region. Notably, the neuronal circuit between pain-related S1 neurons and the parafascicular nucleus contributed to hyperalgesia and anxiety-like behavior. We propose that S1 plays an essential role in sensory and affective responses to noxious stimuli, such as pain.

Growth-related changes in the ultrastructure of the quadriceps tendon.

BACKGROUND: The purpose of this study was to investigate the effect of growth on the ultrastructural characteristics of the quadriceps tendon (QT). METHODS: Eighteen included patients were classified into three groups based on age and epiphyseal plate condition: the 'immature group' consisted of patients with open epiphyseal plates (11.5 ± 1.6 years old; mean ± standard deviation), the 'young group' consisted of patients aged <20 years with closed epiphyseal plates (15.8 ± 1.0 years), and the 'adult group' consisted of all patients aged >20 years (29.8 ± 11.3 years) irrespective of epiphyseal plate condition. Tendon tissue samples were used for ultrastructural analysis by transmission electron microscopy. Minimum collagen fibril diameters were measured from the cross sections of collagen fibril images using Image J software. The average number of collagen fibers per sample was 797 ± 109, and the average collagen fibril diameter of each sample was compared using one-way analysis of variance. RESULTS: The mean collagen fibril diameter was 89.7 ± 14.4 nm in the immature group, 94.8 ± 16.4 nm in the young group, and 107.2 ± 12.1 nm in the adult group, with significant differences between the immature and adult groups, and between the young and adult groups (P = 0.001 and P = 0.021, respectively); however, no significant differences were observed between the immature and young adult groups (P = 0.49). CONCLUSIONS: The collagen fibril diameter of the QT was found to have increased with growth. The study provided insights into graft selection.

Vitreous preservation of articular cartilage from cryoinjury in rabbits.

Frozen osteoarticular grafts treated with liquid nitrogen are utilized for joint reconstruction after tumor resection, but the joints may subsequently develop osteoarthritic changes. To preserve articular cartilage from cryoinjury, we modified a vitrification method utilized for embryo cryopreservation and demonstrated in vitro that our vitrification protocol was effective for protecting cartilage from cryoinjury. In this study, we investigated in vivo whether this vitrification method could protect against osteoarthritic changes in articular cartilage. Osteochondral plugs were obtained from the distal femur of rabbits. These grafts were divided into 3 groups: Fresh group (F-group), non-vitrification group (N-group), and vitrification group (V-group). After treatment, the plugs were re-implanted as autografts. Histological findings, chondrocyte viability, and ultrastructural examinations were examined 6, 12, and 24weeks after implantation. Histological findings of chondrocytes for the V-group showed no significant difference from those of the F-group at any time point except at 24weeks postimplantation at the non-weight bearing site (p<0.05). Viability of chondrocyte showed no significant difference from those of the F-group except at 12weeks postimplantation at the bearing site (p<0.05). In contrast, viable cells disappeared from the N-group and histology and viability significantly differed between the N-group and the V-group. Transmission electron microscopy demonstrated preservation of chondrocyte structure in the V-group and the F-group, but chondrocytes of the N-group were abnormally electron dense. Our vitrification method was effective in protecting chondrocytes from cryoinjury that might lead to cartilage degeneration. Reconstructing joints with osteoarticular grafts containing living cartilage may help to avert osteoarthritic changes. Our vitrification method could prove useful for reconstruction with frozen tumor-containing autografts and for long-term storage of living cartilage for allografts.

The three most common variations of the left renal vein: a review and meta-analysis.

The authors describe three anatomic variations, circumaortic, retroaortic left renal vein, and retropelvic tributary of the renal vein, in Japanese cadavers. The incidences and the clinical significances of these variations are discussed with a detailed review of the literature. The median incidences of circumaortic left renal vein (CLRV) were 7.0% in cadavers examined and 1.8% in clinical subjects examined. The detection of CLRV in CT/MDCT or angiography was relatively difficult compared with that by cadaver dissection. The median incidences of retroaortic left renal vein (RLRV) were 1.7% in cadavers examined and 2.2% in clinical subjects examined. The detection of RLRV was lower in operations, and relatively easy by ultrasonography. The incidence of retropelvic tributary of the renal vein ranged from 30.0 to 46.4%, which is very frequent. Moreover, the incidences of communicating veins between the left renal vein and retroperitoneal veins ranged from 30.0 to 84.2% in cadaver dissections and from 34.0 to 75.8% in clinical reports.