Serum Lactate Clearance as a Predictive Biomarker for Optimal Graft Perfusion in Living Donor Liver Transplantation.

BACKGROUND: The optimal balance between the graft volume (GV) and portal venous flow (PVF) in living donor liver transplantation (LDLT) is unclear. As lactate is mainly metabolized in the liver, perioperative lactate levels are reportedly a useful biomarker for early graft dysfunction (EGD). The present study analyzed perioperative lactate levels according to the PVF. METHODS: The PVF/GV (mL/min per 100 g GV) of 97 recipients from 1996 to 2022 was retrospectively classified as low (LPVF; PVF/GV ≤ 100, N = 29), moderate (MPVF; PVF/GV 100-250, N = 40), or high (HPVF; PVF/GV > 250, N = 28). Lactate levels were obtained preoperatively (L0), immediately after graft reperfusion (L1), 4 h after reperfusion (L2), and on postoperative day 3 (L3). The lactate clearances were then calculated. RESULTS: The lower the PVF/GV ratio, the younger the age at LDLT and the higher the graft-to-recipient weight ratio. The median L2 and L3 in the HPVF group were significantly higher than those in the other groups (p = 0.019 and p = 0.003, respectively). The median ΔL1 in the HPVF group was lower than that in the LPVF and MPVF groups (0.23 vs. 0.50, p < 0.0001 and 0.23 vs. 0.41, p = 0.011, respectively). ΔL1 was negatively correlated with the PVF/GV. Although no patient had EGD, three patients with HPVF with low ΔL1 developed small-for-size syndrome. CONCLUSIONS: Graft hyperperfusion may delay the recovery of the graft function and result in poor lactate clearance. The combination of the PVF/GV and lactate clearance may be useful as a prognostic marker for optimal graft perfusion in LDLT. LEVEL OF EVIDENCE: IV.

A retrospective study investigating the risk of graft loss in living donor liver transplant cases where size mismatching is predicted from graft-to-recipient weight ratio.

BACKGROUND/PURPOSE: Living donor liver transplantation (LDLT) is vital for pediatric end-stage liver disease due to organ shortages. The graft-to-recipient weight ratio (GRWR) preoperatively measured predicts the outcomes of LDLT. We typically target between 0.8 and 3.0-4.0%, but the ideal GRWR remains controversial. We compared the outcomes of LDLT according to the GRWR to examine whether the criteria could be expanded while ensuring safety. METHODS: We retrospectively reviewed 99 patients who underwent LDLT in our department by dividing them into three groups according to their GRWR: Group S, with GRWR values lower than the normal range (GRWR < 0.8%); Group M, with GRWR values in the normal range (GRWR ≥ 0.8 to < 3.5%); and Group L, with GRWR values above the normal range (GRWR ≥ 3.5%). RESULTS: In Groups S and L, 46.2 and 44.4% of patients underwent splenectomy and delayed abdominal wall closure, respectively. After these intraoperative adjustments, there were no significant differences between the groups in 5-year patient survival, 5-year graft survival, or the occurrence of post-transplantation thrombosis. CONCLUSION: When the GRWR is beyond the normal threshold, the risk of complications associated with graft size might be reduced by adjustments to provide appropriate portal blood flow and by delayed abdominal wall closure.

Factors predicting the need for liver transplantation in biliary atresia patients after 18 years of age.

PURPOSE: We aimed to identify factors predicting the need for future liver transplantation (LT) at 18 years of age in patients with biliary atresia (BA). METHODS: BA patients with native liver survival at > 18 years of age were retrospectively reviewed. The clinical characteristics, outcomes, hepatobiliary function, and liver fibrosis markers of native liver survivors (NLS group) were compared with patients who subsequently underwent LT (LT group). RESULTS: The study population included 48 patients (NLS, n = 34; LT, n = 14). The male-to-female ratio, age at Kasai procedure, and type of BA in the two groups did not differ to a statistically significant extent. There was no significant difference in the MELD scores between the groups at 18 years of age. The aspartate aminotransferase-to-platelet ratio index (APRI), albumin-bilirubin (ALBI), and BA liver fibrosis (BALF) scores at 18 years of age were significantly higher in the LT group. The AUCs for APRI, ALBI, and BALF were 0.91, 0.79, and 0.85, respectively. CONCLUSION: Adult BA patients have limited options for LT owing to the lack of donor candidates and the low prevalence of deceased donors. The elucidation of prognostic factors for LT in adulthood is important. APRI was the most useful marker in this study.

Chronic intestinal pseudo-obstruction due to adult-onset acquired isolated hypoganglionosis with muscular atrophy in the small intestine: a case report and review of literature.

BACKGROUND: Chronic intestinal pseudo-obstruction (CIPO) is a rare intestinal disorder characterized by impaired propulsion of the digestive tract and associated with symptoms of intestinal obstruction, despite the absence of obstructive lesions. CIPO includes several diseases. However, definitive diagnosis of its etiology is difficult only with symptoms or imaging findings. CASE PRESENTATION: A 56-year-old man was referred to our hospital due to a 3-year history of continuous abdominal distention. Imaging, including computed tomography of the abdomen, and endoscopy revealed marked dilatation of the entire small intestine without any obstruction point. Therefore, he was diagnosed with CIPO. Since medical therapy didn't improve his symptoms, enterostomy and percutaneous endoscopic gastro-jejunostomy were performed. These procedures improved abdominal symptoms. However, he required home central venous nutrition due to dehydration. The pathological findings of full-thickness biopsies of the small intestine taken during surgery revealed decreased number and degeneration of ganglion cells in the normal plexus. These findings led to a final diagnosis of CIPO due to acquired isolated hypoganglionosis (AIHG). CONCLUSIONS: Here, we report the case of a patient with CIPO secondary to adult-onset AIHG of the small intestine. Since AIHG cannot be solely diagnosed using clinical findings, biopsy is important for its diagnosis.

The advantages of duct-to-duct biliary reconstruction in pediatric living donor liver transplantation.

BACKGROUND/PURPOSE: Whether Roux-en-Y hepatic jejunectomy (HJ) or duct-to-duct biliary reconstruction (DD) is more useful in pediatric living donor liver transplantation has not yet been fully investigated. Therefore, to assess the feasibility and safety of DD, we compared the surgical outcomes of DD to HJ. METHODS: We divided 45 patients, excluding those with biliary atresia, into the DD group (n = 20) and the HJ group (n = 25), according to the type of biliary reconstruction they received. RESULTS: The 5-year survival rates (DD vs. HJ = 79.7% vs. 83.6%, p = 0.70) and the incidence of biliary complications, including bile leakage and stricture (DD vs. HJ = 1 [5.0%] vs. 1 [4.0%], p = 0.87) were not significantly different between the groups. However, intestinal complications, including bowel perforation or ileus, were significantly common in the HJ group (9/25 [36.0%]) than in the DD group (1/20 [5.0%]; p = 0.01). The three patients in the HJ group with intestinal perforation all suffered perforation at the anastomosed site in the Roux-en-Y procedure. The subgroup analysis showed the non-inferiority of DD to HJ for biliary or intestinal complications in patients weighting < 10 kg. CONCLUSION: With a proper selection of cases, DD should be a safe method for biliary reconstruction in pediatric recipients with little risk of biliary complications equivalent to HJ and a reduced risk of intestinal complications.

Cutting-edge regenerative therapy for Hirschsprung disease and its allied disorders.

Hirschsprung disease (HSCR) and its associated disorders (AD-HSCR) often result in severe hypoperistalsis caused by enteric neuropathy, mesenchymopathy, and myopathy. Notably, HSCR involving the small intestine, isolated hypoganglionosis, chronic idiopathic intestinal pseudo-obstruction, and megacystis-microcolon-intestinal hypoperistalsis syndrome carry a poor prognosis. Ultimately, small-bowel transplantation (SBTx) is necessary for refractory cases, but it is highly invasive and outcomes are less than optimal, despite advances in surgical techniques and management. Thus, regenerative therapy has come to light as a potential form of treatment involving regeneration of the enteric nervous system, mesenchyme, and smooth muscle in affected areas. We review the cutting-edge regenerative therapeutic approaches for managing HSCR and AD-HSCR, including the use of enteric nervous system progenitor cells, embryonic stem cells, induced pluripotent stem cells, and mesenchymal stem cells as cell sources, the recipient intestine's microenvironment, and transplantation methods. Perspectives on the future of these treatments are also discussed.

The Factors Associated with the Selection of Early Excision Surgery for Congenital Biliary Dilatation with a Prenatal Diagnosis.

PURPOSE: The aim of this study was to clarify the appropriate management after birth for congenital biliary dilatation (CBD, choledochal cyst) patients with a prenatal diagnosis. METHOD: Thirteen patients with a prenatal diagnosis of CBD who underwent liver biopsy during excision surgery were divided into two groups and retrospectively analyzed: group A, with liver fibrosis above F1 and group B, without liver fibrosis. RESULTS: Excision surgery was performed earlier in group A (F1-F2), at a median of 106 days old (p = 0.04). There were significant differences between the two groups in the presence symptoms and sludge, the cyst size, and the level of serum bilirubin and gamma glutamyl transpeptidase (GGT) before excision surgery (p < 0.05). Especially, in group A, prolonged serum GGT elevation and larger cysts were consistently observed from birth. The cut-off values of predictions for the presence of liver fibrosis in serum GGT and cyst size were 319 U/l and 45 mm. No significant differences were observed in the postoperative liver function or complications during the follow-up period. CONCLUSION: In patients with prenatally diagnosed CBD, the postnatal serial changes of serum GGT values and cyst size, in addition to symptoms, could help to prevent progressive liver fibrosis. LEVEL OF EVIDENCE: Ⅲ. TYPE OF STUDY: Treatment Study.

Massive bleeding from a duodenal ulcer in a child with influenza infection: A case report of endoscopic findings.

Gastrointestinal bleeding or perforation following influenza infection is rare. We encountered a pediatric case of hemorrhagic duodenal ulcer following influenza A infection. The patient was a 1-year and 4-month-old boy who was diagnosed with influenza A infection and treated with laninamivir octanoate. After inhalation, he had diarrhea, poor appetite, and melena. The next day, he had hematochezia and developed hemorrhagic shock. Contrast-enhanced computed tomography showed extravasation in the descending part of the duodenum. Esophagogastroduodenoscopy revealed spurting bleeding from a Dieulafoy's lesion on the oral side of the major papilla, and he underwent hemostasis by clipping. From the bulb to the descending part of the duodenum, the mucosa appeared atrophic with spotty redness on the circular folds and multiple and irregularly shaped erosions. Almost all mucosal lesions had healed by the eighth day, and he was monitored as an outpatient for more than one year without re-bleeding. Intestinal ischemia, viral invasion, and drug reaction of laninamivir octanoate may be involved in duodenal mucosal injury. Acute duodenal ulcers may occur in children with influenza infection, especially young children.

Palisading-like arrangement of immature ganglion cell in myenteric ganglia is a unique pathological feature of immaturity of ganglia.

BACKGROUND: Immaturity of ganglia (IG), an allied disorder of Hirschsprung disease (AD-HSCR), develops as neonatal ileus, but the dysmotility spontaneously resolves after several months. The diagnosis of IG using HE staining is often difficult. We herein report a new pathological finding of IG called the 'palisading-like pattern', which may be helpful for improving the diagnostic accuracy. METHODS: Cases of IG that were managed over the past 28 years were retrospectively reviewed. We investigated the clinical course and pathological findings for Hematoxylin-Eosin (HE) staining. The conventional diagnostic criteria for IG were (1) a normal or slightly increased number of ganglion cells and (2) ganglion cells with small nuclei. RESULTS: Among the 155 cases, 28 were diagnosed with IG, and 10 were retrospectively confirmed by HE staining. A palisading-like pattern was confirmed at the time of the initial ileostomy (median age, 2.5 days), and the palisading-like pattern had completely disappeared by the time of stoma closure (median age, 215 days) in all 10 cases. A palisading-like pattern is not present in other diseases. CONCLUSIONS: Even if immunostaining data are not available for a further analysis, the detection of a palisading-like pattern on HE staining makes an accurate diagnosis possible. LEVEL OF EVIDENCE: LEVEL IV.

Ultrasound-guided double central venous access for azygos vein via the ninth and tenth intercostal veins.

Some patients with intestinal failure, who are dependent on total parenteral nutrition for long periods, suffer from a lack of suitable conventional venous access points, including axillary, external jugular, internal jugular, subclavian, saphenous, and the brachio-cephalic and femoral veins, due to their occlusion. Furthermore, extensive central venous stenosis and/or thrombosis of the superior and inferior vena cava may preclude further catheterization, so uncommon routes must be used, which can be challenging. In such patients, the azygos vein via the intercostal vein is a viable candidate. Thoracotomy-assisted, thoracoscopy-assisted, and cut-down procedures are currently suggested such access. We found that ultrasound-guided percutaneous puncture method was a safe and minimally invasive approach and successfully placed two central venous lines in preparation for small bowel transplantation via two different intercostal veins (ninth and tenth). Although the lung was actually located just below the target veins, an ultrasound provided augmented and clear vision, which contributed to the safe performance of the procedure without the need for invasive surgical intervention, such as thoracotomy, thoracoscopy, or rib resection using the cut-down technique. Furthermore, constant positive-pressure ventilation during vein puncture under general anesthesia also helps avoid venous collapse. Despite carrying a slight risk of light injury to the lung, artery, and nerve along with the vein compared to other procedures, we believe that ultrasound-guided puncture under general anesthesia is feasible as a minimally invasive method.

Biliary atresia in a preterm and extremely low birth weight infant: a case report and literature review.

BACKGROUND: Biliary atresia in very low birth weight (VLBW) and extremely low birth weight (ELBW) infants is rarely reported, and the optimal timing of Kasai portoenterostomy (KPE) in these cases remains unclear. CASE PRESENTATION: We report a case of biliary atresia in a preterm female infant of 24 weeks of gestation who weighed 824 g. She underwent exploratory laparotomy and intraoperative cholangiography at 58 days of age (weight, 1336 g). Despite the diagnosis of biliary atresia with a type I cyst, we could only perform gallbladder drainage at that time due to the unstable intraoperative condition. While we waited for her body weight to increase, KPE was performed at 122 days of age (corrected age: 16 days), when the patient weighed 2296 g. Although she initially became jaundice-free, her liver function deteriorated due to cholangitis, and she developed decompensated cholestatic liver cirrhosis. Living donor liver transplantation was successfully performed at 117 days after KPE, and the postoperative course was uneventful. The timing of KPE is difficult to determine and a review of the relevant literature revealed that a poor prognosis in VLBW and ELBW infants with BA. CONCLUSIONS: Early KPE and careful postoperative follow-up, including liver transplantation is important for the improvement of outcomes.

Evaluating quality indicators of tertiary care hospitals for trauma care in Japan.

OBJECTIVE: This study examined the associations between trauma mortality and quality of care indicators currently used in Japan. DESIGN: This is a retrospective two-level discrete-time survival analysis. Quality indicators were derived from the 2012-2013 annual hospital survey conducted by the Ministry of Health, Labour and Welfare. Trauma mortality data were derived from the Japan Trauma Data Bank for the period of April 2012 to March 2013. SETTING: Tertiary care centers designated as emergency and critical care centers (ECCCs) in Japan. PARTICIPANTS: The analysis included 12 378 patients aged ≥15 years with blunt trauma and an Injury Severity Score ≥9, registered to the data bank from 91 ECCCs. INTERVENTION: Quality of care indicators examined in the annual hospital survey. MAIN OUTCOME MEASURES: Deaths within 30 days. RESULTS: Of the 12 378 patients, 660 (5%) died within 30 days. Higher indicator score was significantly associated with lower mortality risk (hazard ratio [HR] for the second, third and fourth quartiles vs. lowest quartile 0.61, 0.55 and 0.52, respectively). Factors significantly associated with lower mortality risk were, higher patient volume (HR for the highest vs. lowest quartile, 0.74), director's qualification as specialist (HR 0.57) or consultant (HR 0.58), review of patient arrival process (HR 0.68), triage functions (HR 0.69), availability of psychiatrists (HR 0.75) and operating room being ready 24-h (HR 0.81). CONCLUSIONS: The study identified certain indicators associated with trauma patient mortality. Further refinement of indicators is required to specifically identify what needs changing.

Primary Triage in a Mass-casualty Event Possesses a Risk of Increasing Informational Confusion: A Simulation Study Using Shannon's Entropy.

UNLABELLED: Introduction Primary triage in a mass-casualty event setting using low-visibility tags may lead to informational confusion and difficulty in judging triage attribution of patients. In this simulation study, informational confusion during primary triage was investigated using a method described in a prior study that applied Shannon's Information Theory to triage. Hypothesis Primary triage using a low-visibility tag leads to a risk of informational confusion in prioritizing care, owing to the intermingling of pre- and post-triage patients. It is possible that Shannon's entropy evaluates the degree of informational confusion quantitatively and improves primary triage. METHODS: The Simple Triage and Rapid Treatment (START) triage method was employed. In Setting 1, entropy of a triage area with 32 patients was calculated for the following situations: Case 1 - all 32 patients in the triage area at commencement of triage; Case 2 - 16 randomly imported patients to join 16 post-triage patients; Case 3 - eight patients imported randomly and another eight grouped separately; Case 4 - 16 patients grouped separately; Case 5 - random placement of all 32 post-triage patients; Case 6 - isolation of eight patients of minor priority level; Case 7 - division of all patients into two groups of 16; and Case 8 - separation of all patients into four categories of eight each. In Setting 2, entropies in the triage area with 32 patients were calculated continuously with each increase of four post-triage patients in Systems A and B (System A - triage conducted in random manner; and System B - triage arranged into four categories). RESULTS: In Setting 1, entropies in Cases 1-8 were 2.00, 3.00, 2.69, 2.00, 2.00, 1.19, 1.00, and 0.00 bits/symbol, respectively. Entropy increased with random triage. In Setting 2, entropies of System A maintained values the same as, or higher than, those before initiation of triage: 2.00 bits/symbol throughout the triage. The graphic waveform showed a concave shape and took 3.00 bits/symbol as maximal value when the probability of each category was 1/8, whereas the values in System B showed a linear decrease from 2.00 to 0.00 bits/symbol. CONCLUSION: Informational confusion in a primary triage area measured using Shannon's entropy revealed that random triage using a low-visibility tag might increase the degree of confusion. Methods for reducing entropy, such as enhancement of triage colors, may contribute to minimizing informational confusion. Ajimi Y , Sasaki M , Uchida Y , Kaneko I , Nakahara S , Sakamoto T . Primary triage in a mass-casualty event possesses a risk of increasing informational confusion: a simulation study using Shannon's entropy. Prehosp Disaster Med. 2016;31(5):498-504.

Quantitative Evaluation for Uncertainty of Information About Patients' Injury Severity in a Hospital Disaster: A Simulation Study Using Shannon's Information Theory.

INTRODUCTION: Reducing uncertainty about information on injury severity or number of patients is an important concern in managing equipment and rescue personnel in a disaster setting. A simplified disaster model was designed using Shannon's Information Theory to study the uncertainty of information in a triage scenario. Hypothesis A disaster triage scene with a specific number of injured patients represents a source of information regarding the extent of patients' disability. It is possible to quantify uncertainty of information regarding patients' incapacity as entropy if the information source and information arising from the source in Information Theory can be adapted to the disaster situation and the information on patients' incapacity that arises. METHODS: Five different scenarios of a fire disaster in a hospital were modeled. Information on patients' extent of impairment was converted to numerical values in relation to available equipment and the number of rescue personnel. Victims were 10 hospitalized patients with conditions of unknown severity. Triage criteria were created arbitrarily and consisted of four categories from Level 1 (able to walk) to Level 4 (cardiac arrest). The five situations were as follows: (1) Case 1: no triage officer; (2) Case 2: one triage officer; (3) Case 3: one triage officer and a message that six patients could walk; (4) Case 4: one triage officer and a message that all patients could obey commands; and (5) Case 5: one triage officer and a message that all patients could walk. Entropy in all cases and the amount of information newly given in Cases 2 through 5 were calculated. RESULTS: Entropies in Cases 1 through 5 were 5.49, 2.00, 1.60, 1.00, and 0.00 bits/symbol, respectively. These values depict the uncertainty of probability of the triage categories arising in each situation. The amount of information for the triage was calculated as 3.49 bits (ie, 5.49 minus 2.00). In the same manner, the amount of information for the messages in Cases 3 through 5 was calculated as 0.4, 1.0, and 2.0 bits, respectively. These amounts of information indicate a reduction in uncertainty regarding the probability of the triage levels arising. CONCLUSION: It was possible to quantify uncertainty of information about the extent of disability in patients at a triage location and to evaluate reduction of the uncertainty by using entropy based on Shannon's Information Theory.

A pilot study of quantitative capillary refill time to identify high blood lactate levels in critically ill patients.

INTRODUCTION: We developed a new device to quantify capillary refill time (CRT) by applying the pulse oximeter principle, and evaluated the correlation between quantitative CRT (Q-CRT) and hypoperfusion status, as represented by blood lactate levels, in critically ill patients. METHODS: A pilot study was undertaken in the intensive care unit (ICU) in a tertiary emergency medical centre. While the pulse oxygen saturation sensor was placed on the finger of the patients, transmitted light intensity (TLI) was measured with a pulse oximeter (OLV-3100; Nihon Kohden, Tokyo, Japan) before and during compression of the finger. Q-CRT was defined as the interval from the release of compression to the time when TLI reached 90% of baseline. RESULTS: Q-CRT was analysed in a total of 57 waveforms among 23 patients and statistically correlated with lactate levels (Spearman's rank correlation coefficient, 0.681; p<0.001). The cut-off value of Q-CRT for predicting a lactate level of ≥2.0 mmol/L was 6.81 s (area under the curve (AUC) (95% CI 1.000 (1.000 to 1.000), p<0.001), and the value for predicting a lactate level of ≥4.0 mmol/L was 7.27 s (AUC=0.989 (95% CI 0.954 to 1.000), p<0.001). CONCLUSIONS: Q-CRT correlated with blood lactate levels in this pilot study. The most useful threshold for Q-CRT was ∼6-8 s. Further study is needed to investigate the potential role of this modality as a non-invasive predictor of hypoperfusion in the emergency department, ICU and operating room settings.

Bridging classification for injury diagnoses that can be converted to both the International Classification of Diseases and the Abbreviated Injury Scale.

BACKGROUND: The International Statistical Classification of Diseases and Related Health Problems (ICD) is currently undergoing a revision process to develop the Eleventh Revision (ICD-11), but substantial modification of chapter 19 has not been proposed despite its known problems in describing injury severity and multiple injuries. Many facilities treating trauma patients perform duplicate coding for trauma diagnoses using two different classification systems, the ICD for administrative purposes and the Abbreviated Injury Scale (AIS) for trauma registry, because unambiguous conversion of codes between the ICD and AIS is not always possible due to structural differences. AIM: We developed a new bridging classification system which can be unambiguously converted to both ICD and AIS. METHODS AND RESULTS: The bridging classification adopted multidimensional coding and addressed differences in granularity and classification boundaries by adopting the more detailed categorizations whenever the granularity and classification boundaries differed between the ICD and AIS. Then we showed that the bridging classification codes could unambiguously converted to both ICD and AIS. CONCLUSION: Once injuries are coded using the bridging classification, the ICD and AIS codes are readily available. Integrating the new bridging classification into the ICD-11, possibly as a clinical modification, would eliminate the necessity of complicated procedures for code conversion and duplicate coding, and benefit users by building on the strengths of both the ICD and AIS.

M-study from an urban trauma center in Tokyo.

BACKGROUND: The original Trauma and Injury Severity Score (TRISS) methodology from the Major Trauma Outcome Study (MTOS) is the most widely used outcome prediction model. The coefficients from the MTOS cohorts are still used in the Japan Trauma Data Bank for evaluating the quality of patient care. The purposes are to determine whether the database of this institution is well matched to the MTOS study and whether the original TRISS coefficients are accurate predictors of the patient outcome in Japan. METHODS: The M-statistic score was calculated based on the trauma registry data from 2000 to 2003 in Teikyo University. RESULTS: Eight hundred fifty-four cases were analyzed. The crude mortality rate was 10.5%. The mean Injury Severity Score was 15.8 ± 13.6. The mean Revised Trauma Score was 7.00 ± 1.4. The M-statistic score was 0.811. CONCLUSION: The trauma populations in this study differed significantly from the MTOS. The Modified TRISS coefficients should be adapted for outcome assessment based on the location of the injured population. This is the first report of an M-study from Japan to be published in the English literature.

TRPV2-immunoreactive intrinsic neurons in the rat intestine.

Transient receptor potential channel vanilloid subfamily 2 (TRPV2) was shown to receive noxious thermal stimuli (>52 degrees C), and to be expressed in fine myelinated afferent neurons. The mRNA and the immunoreactivity have also been detected in several peripheral tissues. We examined the expression of TRPV2 in the rat intestine. An analysis by transcriptase-polymerase chain reaction (RT-PCR) demonstrated TRPV2 gene expression in the intestine. Many TRPV2-positive neurons were observed in the myenteric plexus by immunohistochemistry. Some of these neurons were positive for calbindin D-28K (CaBP), which is present in intrinsic afferent neurons. TRPV2 immunoreactivity was also observed in nodose ganglion neurons (vagal afferents). These findings suggest that TRPV2 is expressed not only in sensory ganglion neurons, but also in enteric neurons, including primary afferent neurons.

Electroacupuncture induces the expression of Fos in rat dorsal horn via capsaicin-insensitive afferents.

Fos is expressed in rat dorsal horn neurons after electroacupuncture (E-acupuncture), but it is unclear which types of afferent fibers are involved in the expression. It is thought that the Fos expression is induced via Adelta afferents rather than C afferents, since the threshold of Adelta afferents to electrical stimulation is much lower than that of unmyelinated ones. Therefore, neonatally capsaicin treated rats lacking many C afferents were examined to clarify this. Fos expression in the dorsal horn after injection of formalin into the hindpaw was severely attenuated by neonatal capsaicin treatment. However, Fos expression after E-acupuncture to the pads of the hindpaw was unaffected by the same treatment. These results suggest that E-acupuncture induces the expression of Fos in the dorsal horn neurons via capsaicin-insensitive afferents, presumably Adelta afferents.