Characteristics of retained foreign bodies and near-miss events in the operating room: a ten-year experience at one institution.

PURPOSE: Retained foreign bodies (RFBs) are a major complication of surgical procedures. However, the efficacy of preventive measures is not well defined. This study investigates the characteristics of potential (near miss) and actual RFBs, and the contributions of routine practice for the prevention of RFB events. METHODS: We conducted a retrospective review of incident reports regarding near-miss and RFB events in patients who underwent surgery under general anesthesia in our institution between October 2008 and November 2018. RESULTS: Among 49,831 operations under general anesthesia, there were 106 (2.13/1000) near-miss events and 24 (0.48/1000) RFB events. Counting surgical materials and intraoperative X-rays detected the remaining items before completion of surgery in 59 (56%) and 15 (14%) cases, respectively. The operator or staff noticed the surgical materials in the remaining 32 (30%) near-miss events. RFBs included 4 sponges (17%), 4 instruments (17%), 4 needles (17%), and 12 miscellaneous items (50%). Of these, 12 (50%) RFBs were discovered on postoperative X-rays and 16 (67%) patients required operative removal. Four incidents (17%) with RFBs were attributable to ignoring count discrepancies during surgery. CONCLUSION: The actual incidence of RFB events is higher than previously reported. A standardized counting protocol, communication among staff, and intra- and postoperative X-rays may contribute to the prevention and detection of RFBs.

[Lymphocytic colitis caused by medicine ingredient modification].

A 49-year-old woman was referred to our hospital for further evaluation and treatment of diarrhea. Colonoscopic findings revealed indistinct vascular patterns and extensive edema in a colon segment, and white granular mucosa and crack-like appearance in the sigmoid colon and rectum. She was diagnosed with lymphocytic colitis (LC) based on lymphocytic infiltration into the epithelium on histopathological examination. Diarrhea symptoms resolved after long-term medication withdrawal. This medicine's composition was changed 4 years ago and this modification possibly triggered LC.

Characterization of Intra/Extracellular Water States Probed by Ultrabroadband Multiplex Coherent Anti-Stokes Raman Scattering (CARS) Spectroscopic Imaging.

Detailed knowledge of the water status in living organisms is crucial for understanding their physiology and pathophysiology. Here, we developed a technique to spectroscopically image water at high resolution using ultrabroadband multiplex coherent anti-Stokes Raman scattering (CARS) microscopy equipped with a supercontinuum light source. This system allows for the visualization of a wide spectrum of CARS signals from the fingerprint to the end of O-H stretching at a spectral resolution of ∼10 cm-1. Application of the system to living mammalian cells revealed a spectral red shift of the O-H stretching vibrational band inside compared to outside the cells, suggesting the existence of stronger hydrogen bonds inside the cells. Furthermore, potential changes in spectra were examined by adding mannitol to the extracellular solution, which increases the osmolality outside the cells and thereby induces dehydration of the cells. Under this treatment, the red shift of the O-H stretching band was further enhanced, revealing the effects of mannitol on water states inside the cells. The methodology developed here should serve as a powerful tool for the chemical imaging of water in living cells in various biological and medical contexts.

Functional structure and physiological functions of mammalian wild-type HSP60.

The Chaperonins comprise a family of molecular chaperones having a double-ring structure and similar sequence homology. These proteins play an essential role in biological reactions that mediate the folding of newly synthesized polypeptides and partially denatured proteins. In the prokaryotic group I chaperonins, structural and reaction cycle analyses of GroEL and its co-chaperone GroES have been performed in detail. While in eukaryotes, there have been limited reports analyzing the group I chaperonin HSP60 and its co-chaperone HSP10. In the present study, we purified the wild type HSP60 from porcine liver and investigated the interaction between HSP60 and HSP10, including conformation and physiological relationships. Based on the results of transmission electron microscopy, native PAGE, and gel filtration column chromatography, the wild type HSP60 displayed a heptameric single-ring structure in the absence of ATP. In contrast, HSP60 formed mainly a "football-type" complex with HSP10 in the presence of ATP and mediated the refolding of denatured substrate protein. The functional conformation cycle of the purified mammalian HSP60 is distinct from the cycle of the prokaryotic GroEL/GroES chaperonin.

[Analgesia with paravertebral block for postoperative pain after thoracic or thoracoabdominal aortic aneurysm repair].

Paraplegia is a serious complication after thoracoabdominal aortic aneurysm repair. Therefore, maintenance of spinal cord perfusion pressure, drainage of cerebrospinal fluid, and avoidance of opioids are important for prevention of paraplegia Management of acute post-thoracotomy pain is necessary not only to keep the patient comfortable but also to minimize postoperative complications. However, epidural analgesia, a common method of pain control, is hard to use because of existing postoperative coagulopathy and avoidance of spinal cord ischemia Although both paravertebral block and epidural analgesia provide comparable pain relief after thoracic surgery, paravertebral block has lesser detrimental effects on spinal cord perfusion and better preserves the possibility to monitor neurologic function than epidural analgesia. We report 7 cases in which paravertebral blockade was used for analgesia in patients who underwent thoracoabdominal aneurysm repair.

High-Dose Remifentanil Anesthesia With Minimal Sedation in Neonates: A Single-Center Retrospective Study.

Introduction Remifentanil is an opioid with rapid onset and elimination. Theoretically, reducing sedation using high-dose remifentanil may contribute to early emergence and prevention of postanesthetic complications related to residual anesthesia. However, there have been few reports of high-dose remifentanil anesthesia in neonatal surgery. This study aims to describe the techniques of high-dose remifentanil anesthesia in neonates and their safety outcomes. Methods This is a single-center, retrospective observational study from January 2016 to February 2022. Medical records from neonatal surgical procedures performed using high-dose remifentanil anesthesia were reviewed. "High dose" was defined as 0.5 mcg/kg/min or more. Patient profiles, anesthetic drugs used, and intra- and post-operative adverse events, including cardiopulmonary complications, were abstracted. Results There were 15 neonatal abdominal operations performed under high-dose (>0.5 mcg/kg/min) remifentanil anesthesia during the study period. The average remifentanil infusion rate was 1.9 (0.68-3.1) mcg/kg/min. Hypotension occurred in two patients (13%). Bradycardia was not observed in any patients. The mean time for tracheal extubation was 16 minutes. Five patients (33%) received naloxone administration before extubation, and two patients (13%) experienced hypoxemia immediately after extubation. No patient had cardiorespiratory complications after leaving the operating room. Conclusions High-dose remifentanil can be used without impairing hemodynamic stability in neonatal surgery, although there is concern about respiratory depression. Further research is needed on its potential impact on long-term outcomes.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) in the presence of associated severe traumatic brain injury: A propensity-score matched study.

BACKGROUND: Experimental work suggested that resuscitative Endovascular Balloon Occlusion of the aorta (REBOA) preserves cerebral circulation in animal models of traumatic brain injury. No clinical work has evaluated the role of REBOA in the presence of associated severe traumatic brain injury (TBI). We investigated the impacts of REBOA on neurological and survival outcomes. METHODS: Propensity-score matched study, using the American College of Surgeons Trauma Quality Improvement Program database. Patients with severe TBI patients (Abbreviated Injury Scale ≥3) receiving REBOA within 4 â€‹h from arrival were matched with similar patients not receiving REBOA. Neurological matching included head AIS, pupils, and midline shift. Clinical outcomes were compared between the two groups. RESULTS: 434 REBOA patients were matched with 859 patients without REBOA. Patients in the REBOA group had higher rates of in-hospital mortality (63.6 â€‹% vs 44.2 â€‹%, p â€‹< â€‹0.001), severe sepsis (4.4 â€‹% vs 2.2 â€‹%, p â€‹= â€‹0.029), acute kidney injury (10.1 â€‹% vs 6.6 â€‹%, p â€‹= â€‹0.029), and withdrawal of life support (25.4 â€‹% vs 19.6 â€‹%, p â€‹= â€‹0.020) despite of lower craniectomy/craniotomy rate (7.1 â€‹% vs 12.7 â€‹%, p â€‹< â€‹0.002). CONCLUSION: In patients with severe TBI, REBOA use is associated with an increased risk of in-hospital mortality, AKI, and infectious complications.

Recent Changes in the Management of High-Grade Blunt Pancreatic Injury in Children: A Nationwide Trend Analysis.

BACKGROUND: The optimal management of pediatric patients with high-grade blunt pancreatic injury (BPI) involving the main pancreatic duct remains controversial. This study aimed to assess the nationwide trends in the management of pediatric high-grade BPI at pediatric (PTC), mixed (MTC), and adult trauma centers (ATC). STUDY DESIGN: This is a retrospective observational study of the National Trauma Data Bank. We included pediatric patients (age 16 years or less) sustaining high-grade BPI (Abbreviated Injury Scale 3 or more) from 2011 to 2021. Patients who did not undergo pancreatic operation were categorized into the nonoperative management (NOM) group. Trauma centers were defined as PTC (level I/II pediatric only), MTC (level I/II adult and pediatric), and ATC (level I/II adult only). Primary outcome was the proportion of patients undergoing NOM, and secondary outcomes included the use of ERCP and in-hospital mortality. A Cochran-Armitage test was used to analyze the trend. RESULTS: A total of 811 patients were analyzed. The median age was 9 years (interquartile range 6 to 13), 64% were male patients, and the median injury severity score was 17 (interquartile range 10 to 25). During the study period, there was a significant upward linear trend in the use of NOM and ERCP among the overall cohort (range 48% to 66%; p trend = 0.033, range 6.1% to 19%; p trend = 0.030, respectively). The significant upward trend for NOM was maintained in the subgroup of patients at PTC and MTC (p trend = 0.037), whereas no significant trend was observed at ATC (p trend = 0.61). There was no significant trend in in-hospital mortality (p trend = 0.38). CONCLUSIONS: For the management of pediatric patients with high-grade BPI, this study found a significant trend toward increasing use of NOM and ERCP without mortality deterioration, especially at PTC and MTC.

Surgical trends and outcomes of open, laparoscopic, and robotic colostomy reversal for benign disease.

BACKGROUND: Despite the increasing use of minimally invasive surgeries, the outcome benefits of adopting minimally invasive surgery for colostomy reversal remain unclear. We aimed to analyze nationwide trends in the use of minimally invasive surgery for colostomy reversal and compare patient outcomes between different surgical approaches. METHODS: The National Inpatient Sample was queried for patients who underwent colostomy reversal for benign disease from 2015 to 2021. National trends in the use of minimally invasive surgery for colostomy reversal were analyzed by Cochran-Armitage tests. Multivariable linear and logistic regressions accounting for hospital sample weights were developed to examine the association between operative approach (open, laparoscopic, and robotic) and patient outcomes, including hospital complications, length of stay, and hospital charges. RESULTS: A total of 23,260 patients underwent colostomy reversal: 18,880 (81.2%) open, 3,245 (14.0%) laparoscopic, and 1,135 (4.9%) robotic surgery. From 2015 to 2021, the proportion of robotic approaches increased >5-fold (range 2.1-12.5%; Ptrend < .001), whereas the increase in laparoscopic approaches was not significant (range 11.5-16.2%; Ptrend = .34). Multivariable analysis showed that the laparoscopic approach was associated with a lower incidence of pulmonary complications (adjusted odds ratio, 0.49; 95% confidence interval, 0.28-0.87), surgical-site infection (odds ratio, 0.37; 95% CI, 0.19-0.72), peritonitis/abdominal abscess (odds ratio, 0.45; 95% confidence interval, 0.26-0.78), and paralytic ileus (odds ratio, 0.67; 95% confidence interval, 0.48-0.92). The robotic approach was associated with a lower incidence of paralytic ileus (odds ratio, 0.58; 95% confidence interval, 0.33-0.99). Laparoscopic and robotic approaches were associated with 22.9% and 29.9% shorter length of stay, respectively. The robotic approach was associated with 33.0% greater hospital charge. CONCLUSIONS: This study observed a significant trend toward the increased use of robotics in colostomy reversal and potential clinical benefits with minimally invasive surgery. Robotic colostomy reversal, along with laparoscopic approach, may provide better postoperative recovery compared with the open approach; however, the utility of robotic surgeries needs to be reevaluated in the future, given the limited clinical benefits despite greater hospital charges.

Clinical profile of patients with diabetic ketoacidosis and hyperglycemic hyperosmolar syndrome in Japan: a multicenter retrospective cohort study.

INTRODUCTION: Diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar syndrome (HHS) are life-threatening complications of diabetes mellitus. Their clinical profiles have not been fully investigated. METHODS: A multicenter retrospective cohort study was conducted in 21 acute care hospitals in Japan. Patients included were adults aged 18 or older who had been hospitalized from January 1, 2012, to December 31, 2016 due to DKA or HHS. The data were extracted from patient medical records. A four-group comparison (mild DKA, moderate DKA, severe DKA, and HHS) was performed to evaluate outcomes. RESULTS: A total of 771 patients including 545 patients with DKA and 226 patients with HHS were identified during the study period. The major precipitating factors of disease episodes were poor medication compliance, infectious diseases, and excessive drinking of sugar-sweetened beverages. The median hospital stay was 16 days [IQR 10-26 days]. The intensive care unit (ICU) admission rate was 44.4% (mean) and the rate at each hospital ranged from 0 to 100%. The in-hospital mortality rate was 2.8% in patients with DKA and 7.1% in the HHS group. No significant difference in mortality was seen among the three DKA groups. CONCLUSIONS: The mortality rate of patients with DKA in Japan is similar to other studies, while that of HHS was lower. The ICU admission rate varied among institutions. There was no significant association between the severity of DKA and mortality in the study population. TRIAL REGISTRATION: This study is registered in the UMIN clinical Trial Registration System (UMIN000025393, Registered 23th December 2016).

High versus low chloride load in adult hyperglycemic emergencies with acute kidney injury: a multicenter retrospective cohort study.

Hyperglycemic emergencies frequently lead to acute kidney injury (AKI) and require treatment with large amount of intravenous fluids. However, the effects of chloride loading on this population have not yet been investigated. We conducted a multicenter, retrospective, cohort study in 21 acute-care hospitals in Japan. The study included hospitalized adult patients with diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic syndrome (HHS) who had AKI upon arrival. The patients were classified into high and low chloride groups based on the amount of chloride administered within the first 48 h of their arrival. The primary outcome was recovery from AKI; secondary outcome was major adverse kidney events within 30 days (MAKE30), including mortality and prolonged renal failure. A total of 390 patients with AKI, including 268 (69%) with DKA and 122 (31%) with HHS, were included in the study. Using the criteria of Kidney Disease Improving Global Outcomes, the severity of AKI in the patients was Stage 1 (n = 159, 41%), Stage 2 (n = 121, 31%), and Stage 3 (n = 110, 28%). The analysis showed no significant difference between the two groups in recovery from AKI (adjusted hazard ratio, 0.96; 95% CI 0.72-1.28; P = 0.78) and in MAKE30 (adjusted odds ratio, 0.91; 95% CI 0.45-1.76; P = 0.80). Chloride loading with fluid administration had no significant impact on recovery from AKI in patients with hyperglycemic emergencies.Trial Registration This study was registered in the UMIN clinical trial registration system (UMIN000025393, registered December 23, 2016).

Epidemiology, microbiology, and diagnosis of infection in diabetic ketoacidosis and hyperosmolar hyperglycemic syndrome: A multicenter retrospective observational study.

AIMS: We investigated the characteristics of infection and the utility of inflammatory markers in diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic syndrome (HHS). METHODS: A multicenter, retrospective observational study in 21 acute-care hospitals was conducted in Japan. This study included adult hospitalized patients with DKA and HHS. We analyzed the diagnostic accuracy of markers including C-reactive protein (CRP) and procalcitonin (PCT) for bacteremia. Multiple regression models were created for estimating bacteremia risk factors. RESULTS: A total of 771 patients, including 545 patients with DKA and 226 patients with HHS, were analyzed. The mean age was 58.2 (SD, 19.3) years. Of these, 70 tested positive for blood culture. The mortality rates of those with and without bacteremia were 14 % and 3.3 % (P-value < 0.001). The area under the curve (AUC) of CRP and PCT for diagnosis of bacteremia was 0.85 (95 %CI, 0.81-0.89) and 0.76 (95 %CI, 0.60-0.92), respectively. Logistic regression models identified older age, altered level of consciousness, hypotension, and higher CRP as risk factors for bacteremia. CONCLUSIONS: The mortality rate was higher in patients with bacteremia than patients without it. CRP, rather than PCT, may be valid for diagnosing bacteremia in hyperglycemic emergencies. TRIAL REGISTRATION: This study is registered in the UMIN clinical trial registration system (UMIN000025393, Registered December 23, 2016).

Anesthetic management of a pediatric patient with Freeman-Sheldon syndrome undergoing atrial septal defect closure: a case report.

BACKGROUND: Freeman-Sheldon syndrome (FSS) is a rare disorder characterized by specific deformities of the extremities and face. There have been no reports of open-heart surgery in pediatric patients with FSS. CASE PRESENTATION: We present the case of an 8-year-old girl with FSS who underwent atrial septal defect closure. Tracheal intubation was uncomplicated, although the patient had microstomia. Inhalational anesthetics and dopamine antagonists were avoided intraoperatively and perioperatively. We chose dexmedetomidine as an adjuvant for postoperative pain management contributing to adequate analgesia and early extubation without causing respiratory depression. CONCLUSIONS: Anesthetic management of FSS requires consideration for airway management and prevention of malignant hyperthermia and respiratory complications. We successfully managed the case avoiding the use of malignant hyperthermia-triggering drugs.

A low peripheral perfusion index can accurately detect prolonged capillary refill time during general anesthesia: A prospective observational study.

Background: Capillary refill time (CRT) is the gold standard for evaluating peripheral organ perfusion; however, intraoperative CRT measurement is rarely used because it cannot be conducted continuously, and it is difficult to perform during general anesthesia. The peripheral perfusion index (PI) is another noninvasive method for evaluating peripheral perfusion. The PI can easily and continuously evaluate peripheral perfusion and could be an alternative to CRT for use during general anesthesia. This study aimed to determine the cutoff PI value for low peripheral perfusion status (prolonged CRT) by exploring the relationship between CRT and the PI during general anesthesia. Methods: We enrolled 127 surgical patients. CRT and the PI were measured in a hemodynamically stable state during general anesthesia. A CRT >3 s indicated a low perfusion status. Results: Prolonged CRT was observed in 27 patients. The median PI values in the non-prolonged and prolonged CRT groups were 5.0 (3.3-7.9) and 1.5 (1.2-1.9), respectively. There was a strong negative correlation between the PI and CRT (r = -0.706). The area under the receiver operating characteristic curve generated for the PI was 0.989 (95% confidence interval, 0.976-1.0). The cutoff PI value for detecting a prolonged CRT was 1.8. Conclusion: A PI <1.8 could accurately predict a low perfusion status during general anesthesia in the operating room. A PI <1.8 could be used to alert the possibility of a low perfusion status in the operating room. Trial Registration: University Hospital Medical Information Network (UMIN000043707; retrospectively registered on March 22, 2021, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno = R000049905).

Association between Plasma Ascorbic Acid Levels and Postoperative Delirium in Older Patients Undergoing Cardiovascular Surgery: A Prospective Observational Study.

BACKGROUND: The incidence of delirium is high in older patients undergoing cardiovascular surgery with cardiopulmonary bypass (CPB). Intraoperative tissue hypoperfusion and re-reperfusion injury, which generate reactive oxygen species (ROS), are suggested to induce delirium. Ascorbic acid is an excellent antioxidant and may reduce organ damage by inhibiting the production of ROS. This prospective observational study aimed to measure pre- and postoperative plasma ascorbic acid levels and examine their association with delirium. METHODS: Patients older than 70 years of age scheduled for elective cardiovascular surgery using CPB were enrolled. From September 2020 to December 2021, we enrolled 100 patients, and the data of 98 patients were analyzed. RESULTS: In total, 31 patients developed delirium, while 67 did not. Preoperative plasma ascorbic acid levels did not differ between the non-delirium and delirium groups (6.0 ± 2.2 vs. 5.5 ± 2.4 µg/mL, p = 0.3). Postoperative plasma ascorbic acid levels were significantly different between the groups (2.8 [2.3-3.5] vs. 2.3 [1.6-3.3] µg/mL, p = 0.037). CONCLUSIONS: In patients who undergo cardiovascular surgery with CPB, lower postoperative plasma ascorbic acid levels may be associated with the development of delirium.

Optimal target blood pressure in elderly with septic shock (OPTPRESS) trial: study protocol for a randomized controlled trial.

BACKGROUND: Hemodynamic stabilization is a core component in the resuscitation of septic shock. However, the optimal target blood pressure remains debatable. Previous randomized controlled trials suggested that uniformly adopting a target mean arterial pressure (MAP) higher than 65 mmHg for all adult septic shock patients would not be beneficial; however, it has also been proposed that higher target MAP may be beneficial for elderly patients, especially those with arteriosclerosis. METHODS: A multicenter, pragmatic single-blind randomized controlled trial will be conducted to compare target MAP of 80-85 mmHg (high-target) and 65-70 mmHg (control) in the resuscitation of septic shock patients admitted to 28 hospitals in Japan. Patients with septic shock aged ≥65 years are randomly assigned to the high-target or control groups. The target MAP shall be maintained for 72 h after randomization or until vasopressors are no longer needed to improve patients' condition. To minimize the adverse effects related to catecholamines, if norepinephrine dose of ≥ 0.1 µg/kg/min is needed to maintain the target MAP, vasopressin will be initiated. Other therapeutic approaches, including fluid administration, hydrocortisone use, and antibiotic choice, will be determined by the physician in charge based on the latest clinical guidelines. The primary outcome is all-cause mortality at 90 days after randomization. DISCUSSION: The result of this trial will provide great insight on the resuscitation strategy for septic shock in the era of global aged society. Also, it will provide the better understanding on the importance of individualized treatment strategy in hemodynamic management in critically ill patients. TRIAL REGISTRATION: UMIN Clinical Trials Registry; UMIN000041775. Registered 13 September 2020.

Anesthetic management of pulmonary artery replacement for idiopathic dilatation of the pulmonary artery with a Kommerell's diverticulum: a case report.

BACKGROUND: Idiopathic dilatation of the pulmonary artery (IDPA) is a rare condition in which the pulmonary artery dilates without an obvious cause. Pulmonary artery replacement is indicated in severe cases to prevent serious complications. CASE PRESENTATION: A 59-year-old man was diagnosed with an IDPA of 64 mm and Kommerell's diverticulum (aortic aneurysm located at the aberrant left subclavian artery). A computed tomography scan revealed slight compression of the aneurysm to the trachea, although not interfering with airway management. The surgical approach was a median sternotomy, and cardiopulmonary bypass was established through aortic and bicaval cannulations. The perioperative course was uneventful. CONCLUSIONS: To prevent injury to the dilated pulmonary artery, a strategy for cardiopulmonary bypass and a surgical approach should be discussed beforehand. As dilatation of the pulmonary artery is often complicated by anatomic abnormalities, preoperative evaluation should be aimed at appropriate assessments using imaging modalities.

Age Is Associated With the Efficacy of Anticoagulant Therapies Against Sepsis-Induced Disseminated Intravascular Coagulation.

Disseminated Intravascular Coagulation (DIC) commonly complicates sepsis and considerably worsens mortality. Recent studies suggested that anticoagulant therapies improved mortality only in specific sepsis populations, and key pathologies for selecting optimal targets needed to be identified. Anticoagulant activities were naturally altered with aging. This study aimed to evaluate age-related differences in efficacy of anticoagulant therapies in sepsis. This post hoc analysis of a nationwide multicenter cohort study was conducted in 42 intensive care units in Japan. Adult patients with septic DIC were divided into anticoagulant and control groups. Age-related changes in predicted mortality in both groups were compared using a logistic regression model including 2-way interaction terms. Patients were also stratified into 3 subsets based on age, and propensity score-adjusted Cox regression analyses were conducted to examine survival effect of anticoagulants in each subset. We included 1432 patients with septic DIC; 867 patients received anticoagulants and 565 received none. Age-related change in predicted mortality was significantly different between groups (P for interaction = 0.013), and the gap between groups was broad in the younger population. Similarly, in Cox regression analyses, anticoagulant therapies were associated with significantly lower mortality in the subsets of age ≤ 60 and 60-79 (hazard ratios = 0.461, 0.617, P = 0.007, 0.005, respectively), whereas there was no difference in survival between the groups in the subsets of age ≥ 80. The efficacy of anticoagulant therapies for septic DIC might be associated with patient age.

Triphenyl phosphate delayed pubertal timing and induced decline of ovarian reserve in mice as an estrogen receptor antagonist.

Although concerns have been raised about the adverse effects of triphenyl phosphate (TPhP) on female fertility, its risk to ovarian functioning remains unknown. In this study, female C57BL/6 mice at postnatal day 21 were exposed on a daily basis to TPhP dose of 2, 10, and 50 mg/kg for 40 days. A significant delay in pubertal timing was observed in the mice exposed to 50 mg/kg of TPhP. An estrogen-responsive reporter transgenic mice assay demonstrated that TPhP significantly downregulated the estrogen receptor (ER) signaling by 45.1% in the whole body in the 50 mg/kg group, and by 14.7-43.7% in the uterus for all exposure groups compared with the control. This strong antagonistic activity of TPhP toward ER explained the delay in pubertal timing. A significant reduction in the number of follicles in all stages was observed in mice after being exposed to TPhP for 40 days at concentrations of 10 and 50 mg/kg, resulting in a decline of the ovarian reserve. The elevation of the follicle-stimulating hormone concentration may have contributed to this phenomenon, as controlled by the antagonistic activity of TPhP toward ER in the brain. The toxic effects of TPhP on ovarian functioning highlight this chemical as a potential risk factor for female fertility.