Sex Differences in the Relationship between Excessive Alcohol Consumption and Metabolic Abnormalities: A Community-Based Study in Taiwan.

Excessive alcohol consumption, as part of an unhealthy lifestyle, can contribute to metabolic abnormalities. This study investigated the sex differences in the relationship between excessive drinking and the risk of metabolic abnormalities. This community-based study included 3387 participants (age range: 30-103 years, mean age ± SD: 57 ± 13.5 years, 38.2% males) from the northeastern region of Taiwan. All participants completed a demographic survey and were subjected to blood tests. The risks of excessive drinking were evaluated using the Alcohol Use Disorder Identification Test (AUDIT). The results showed that males were at higher risks of obesity, hypertension, and hypertriglyceridemia, but at a lower risk of abdominal obesity than females. Males with hazardous drinking were at greater risks of hypertension, hyperglycemia, low serum levels of high-density lipoprotein cholesterol, and hypertriglyceridemia compared to those with no drinking. Females with hazardous drinking were at a greater risk of hypertension than those with no drinking. There was no interaction effect of sex and excessive drinking on the risks of metabolic abnormalities after controlling for demographics and lifestyle-related habits. Future studies are warranted to explore the sex-specific risk factors for metabolic abnormalities and to elucidate the mechanism underlying this association between alcohol consumption and metabolic abnormalities.

Vancomycin-Associated Acute Kidney Injury: A Narrative Review from Pathophysiology to Clinical Application.

Vancomycin is the most frequently used antibiotic, accounting for up to 35% of hospitalized patients with infection, because of its optimal bactericidal effectiveness and relatively low price. Vancomycin-associated AKI (VA-AKI) is a clinically relevant but not yet clearly understood entity in critically ill patients. The current review comprehensively summarizes the pathophysiological mechanisms of, biomarkers for, preventive strategies for, and some crucial issues with VA-AKI. The pathological manifestations of VA-AKI include acute tubular necrosis, acute tubulointerstitial nephritis (ATIN), and intratubular crystal obstruction. The proposed pathological mechanisms of VA-AKI include oxidative stress and allergic reactions induced by vancomycin and vancomycin-associated tubular casts. Concomitant administration with other nephrotoxic antibiotics, such as piperacillin-tazobactam, high vancomycin doses, and intermittent infusion strategies compared to the continuous infusion are associated with a higher risk of VA-AKI. Several biomarkers could be applied to predict and diagnose VA-AKI. To date, no promising therapy is available. Oral steroids could be considered for patients with ATIN, whereas hemodialysis might be applied to remove vancomycin from the patient. In the future, disclosing more promising biomarkers that could precisely identify populations susceptible to VA-AKI and detect VA-AKI occurrence early on, and developing pharmacological agents that could prevent or treat VA-AKI, are the keys to improve the prognoses of patients with severe infection who probably need vancomycin therapy.

Positive Effects of Laser Acupuncture in Methamphetamine Users Undergoing Group Cognitive Behavioral Therapy: A Pilot Study.

BACKGROUND: Methamphetamine (MA) addiction has become a crucial public health concern because of its adverse consequences to individuals and the society. OBJECTIVE: To investigate the clinical efficacy of laser acupuncture combined with group cognitive behavioral therapy for MA addiction treatment. MATERIALS AND METHODS: MA users who participated in group cognitive behavioral therapy and met the inclusion criteria were referred from psychiatrists to participate. The participants received laser acupuncture treatment once a week for 2 months (total eight treatments) on selected acupoints (PC6, HT7, LI4, ST36, SP6, and LR3). Laboratory assessment included urinalysis for MA and liver function tests aspartate aminotransferase, alanine aminotransferase, and γ-glutamyltransferase (AST, ALT, and γ-GT), whereas the objective assessment included visual analog scale (VAS) for MA craving and refusal and Pittsburgh sleep quality index (PSQI), Beck Anxiety Inventory (BAI), and Beck Depression Inventory (BDI) questionnaires. All data were collected before and at 1 and 2 months after treatment. Cognitive behavioral therapy completion rate and rate of relapse to MA use were also determined. RESULT: Fifteen participants were enrolled, of whom seven completed the trial. Urinalysis for MA revealed a decrease in drug use from 57.1% to 28.6%. Compared with those before treatment, PSQI scores were significantly lower at 1 and 2 months after treatment (-3.73 and -4.10, respectively; both p < 0.001), and so were BDI scores (-5.64 and -8.17, respectively; p=0.01 and 0.001, respectively). However, no significant difference was observed in the liver function test, VAS of craving and refusal, and BAI results. A slight improvement in the motivation for drug abstinence and anxiety was observed during the treatment course. Participants reported no adverse events. CONCLUSION: Laser acupuncture combined with group cognitive behavioral therapy may improve sleep quality, alleviate depression, and reduce MA use. Additional large-scale studies confirming the effectiveness of this modality are warranted.

Acoustic preadaptation to transmit vocal individuality of savanna nightjars in noisy urban environments.

As urbanization has expanded dramatically, the impacts of urban noise on wildlife have drawn increasing attention. However, previous studies have focused primarily on diurnal songbirds and much less on nocturnal nonpasserines such as nightjars. The savanna nightjar has recently successfully colonized urban areas in Taiwan. Using 1925 calls recorded from 67 individuals, we first investigated the individual differences of the acoustic structures; and, for those acoustic variables with significant individual differences, we examined the correlation between the acoustic structures and the ambient noise levels. We then compared the transmission efficacy of vocal individuality among three sets of acoustic variables: all acoustic variables, noise-related variables, and noise-unrelated variables. Using seven artificial frequency-shifted calls to represent seven different individuals in playback-recording experiments, we also investigated the transmission efficacy of vocal individuality and variable accuracy in three different urban noise levels (high, medium, low). We found that all 30 acoustic variables derived from the acoustic structures demonstrated significant individual differences, and 14 frequency-based variables were negatively correlated with ambient noise levels. Although transmission efficacy was significantly affected by urban noise, individuality information was still transmitted with high accuracy. Furthermore, the noise-unrelated structures (which included the maximum frequency, the maximum amplitude frequency, and the mean frequency of the call) had a significantly higher transmission efficacy of vocal individuality than the noise-related variables (which included the minimum frequency, the frequency at the start and the end of the call) in both field observation and playback-recording experiments. We conclude that these noise-unrelated acoustic features may be one of the key preadaptations for this nocturnal nonpasserine to thrive so successfully in its newly adopted urban environment.

Optimization of extracorporeal membrane oxygenation therapy using near-infrared spectroscopy to assess changes in peripheral circulation: A pilot study.

Near-infrared spectroscopy (NIRS) has been proposed as a noninvasive modality for detecting complications in patients undergoing extracorporeal membrane oxygenation (ECMO), and it can simultaneously reveal the global circulatory status of these patients. We optimized ECMO therapy on the basis of real-time peripheral NIRS probing. Three patients underwent venoarterial (VA) ECMO and one patient underwent venovenous (VV) ECMO. All patients received peripheral ECMO cannulation with routine distal perfusion catheter placement. We designed an experimental protocol to adjust ECMO blood flow over 1 hour. Hemodynamic responses were measured using NIRS devices attached to the calf at approximately 60% of the distance from the ankle to the knee. HbO2 levels change substantially with adjustments in ECMO flow, and they are more sensitive than HHb levels and the tissue saturation index (TSI) are. NIRS for optimizing ECMO therapy may be reliable for monitoring global circulatory status.

Biomechanical effects of screw orientation and plate profile on tibial condylar valgus osteotomy - Finite-element analysis.

Tibial condylar valgus osteotomy (TCVO) is a type of open wedge high tibial osteotomy for correcting intra-articular deformities of medial knee osteoarthritis. However, there are no implant design and related biomechanical investigations specifically for TCVO. This study aims to investigate the effects of the proximal screw direction and plate profile on the biomechanical behaviors of the TCVO construct. Based on computed tomography images, the tibia model with TCVO was simulated. Four variations (straight and contoured plate profile × convergent and divergent proximal screw direction) with two loading conditions (compressive loads and torsional load) were compared by finite-element method. Fracture risk and construct stability were chosen as the comparison indices. For both loading conditions, the fracture risk of screw, plate and bone was the lowest in straight plate with divergent screw direction (SD), while contoured plate with convergent screw direction (CC) was the highest. Similar results were found in construct stability, SD allowed the smallest micromotions of the L-shaped opening gap, but CC allowed the highest. Divergent screw direction can decrease fracture risk of all components and provide better construct stability, while contoured plate profile seems like to have converse effects. If stability is the major concern, straight plate with divergent screw is recommended for patients with heavy load demands. Contoured plate may be suitable for skinny patients that can reduce the soft tissue irritation.

BMP controls dorsoventral and neural patterning in indirect-developing hemichordates providing insight into a possible origin of chordates.

A defining feature of chordates is the unique presence of a dorsal hollow neural tube that forms by internalization of the ectodermal neural plate specified via inhibition of BMP signaling during gastrulation. While BMP controls dorsoventral (DV) patterning across diverse bilaterians, the BMP-active side is ventral in chordates and dorsal in many other bilaterians. How this phylum-specific DV inversion occurs and whether it is coupled to the emergence of the dorsal neural plate are unknown. Here we explore these questions by investigating an indirect-developing enteropneust from the hemichordate phylum, which together with echinoderms form a sister group of the chordates. We found that in the hemichordate larva, BMP signaling is required for DV patterning and is sufficient to repress neurogenesis. We also found that transient overactivation of BMP signaling during gastrulation concomitantly blocked mouth formation and centralized the nervous system to the ventral ectoderm in both hemichordate and sea urchin larvae. Moreover, this mouthless, neurogenic ventral ectoderm displayed a medial-to-lateral organization similar to that of the chordate neural plate. Thus, indirect-developing deuterostomes use BMP signaling in DV and neural patterning, and an elevated BMP level during gastrulation drives pronounced morphological changes reminiscent of a DV inversion. These findings provide a mechanistic basis to support the hypothesis that an inverse chordate body plan emerged from an indirect-developing ancestor by tinkering with BMP signaling.

Increased Risk of Ulcerative Colitis in Patients with Periodontal Disease: A Nationwide Population-Based Cohort Study.

Both periodontal disease (PD) and inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are important diseases of the alimentary tract. Microbiome and immune-mediated inflammatory processes play important roles in these diseases. An association between PD and IBD may exist. This study investigated the risk of IBD in patients with PD. This study used data from the National Health Insurance Research Database of Taiwan from 1996 to 2013. A total of 27,041 patients with PD were enrolled as a study group, and 108,149 patients without PD were selected as the control group after matching by gender, age, insured region, urbanization, and income with a 1:4 ratio. Cox proportional hazards regression was used to calculate the risk of IBD. Of the 135,190 participants enrolled in this study, 5392 (4%) with newly diagnosed IBD were identified. The overall incidence of subsequent IBD was similar in both groups (3.8% vs. 4%, adjusted hazard ratio (aHR) = 1.01, 95% confidence interval (CI): 0.94⁻1.08). However, an increased risk of UC in the PD group was found after adjusting confounding factors (aHR: 1.56, 95% CI: 1.13⁻2.15; p < 0.05). This study demonstrated that patients with PD had approximately one-half higher risk of subsequent UC. Further studies are warranted to elucidate the relationship between PD and UC.

Could schizoaffective disorder, schizophrenia and bipolar I disorder be distinguishable using cognitive profiles?

This study seeks to determine whether the cognition profiles of patients with schizoaffective disorder (SAD), schizophrenia and bipolar I disorder (BD) are distinguishable. A total of 227 participants, comprising 88 healthy control subjects, 50 patients with SAD, 48 patients with schizophrenia and 41 patients with BD, were recruited. The participants' cognitive functions were evaluated using the Brief Assessment of Cognition in Schizophrenia (BACS). A discriminant functions analysis (DFA) was conducted to determine whether using cognitive performance can be used to distinguish these participant groups. Relative to healthy control subjects, patients with SAD, schizophrenia and BD exhibited significant deficits in all cognitive domains (verbal memory, working memory, motor speed, verbal fluency, attention and processing speed, executive function and a composite BACS score). Among the three patient groups, the schizophrenia group exhibited particularly impaired motor speed, and the BD group performed best in attention, processing speed, executive function and the composite BACS score. The classification accuracy rates of patients with SAD, schizophrenia and BD in the DFA model were 38%, 47.9% and 46.3%, respectively. These findings suggest that the impairments of some cognitive domains were less severe in patients with BD than in patients with schizophrenia or SAD.

Cognitive profile of ketamine-dependent patients compared with methamphetamine-dependent patients and healthy controls.

BACKGROUND: Ketamine has emerged as a major substance of abuse worldwide and has been listed with methamphetamine (METH) as two of the most widely available illicit substances in Taiwan. Only a few studies have examined the long-term consequences of chronic and heavy ketamine abuse. We compared the cognitive function of ketamine-dependent patients with that of METH-dependent patients and healthy controls. METHODS: We recruited 165 participants (58 ketamine-dependent and 49 METH-dependent patients who sought treatment and 58 healthy controls) and evaluated them by using a cognitive test battery, the Brief Assessment of Cognition in Schizophrenia, with scores being estimated in reference to normative data in general population. RESULTS: The ketamine-dependent patients had significantly poorer performance than did the controls in many cognitive tests, including verbal memory, motor speed, verbal fluency, and attention and processing speed, and the battery as a whole. METH-dependent patients exhibited poorer function in motor speed, verbal fluency, and attention and processing speed. The ketamine group performed poorer than did METH group in the domains of verbal memory, working memory, and attention and processing speed and the composite battery scores. A previous experience of ketamine-induced psychotomimetic symptoms, using higher doses of ketamine, and longer abstinence appeared to be associated with performance in some tests; however, the significance disappeared after multiple comparison correction. CONCLUSIONS: The ketamine-dependent patients had impaired cognitive function, and METH-dependent patients exhibited intermediate performance between ketamine-dependent patients and healthy controls. Given the growing population of ketamine abusers, public education on the cognitive consequences should be provided.

BanI polymorphism of cytosolic phospholipase A2 gene and somatic symptoms in medication-free acute depressed patients.

Somatic symptoms are commonly seen in patients with major depressive disorder (MDD) and might be associated with inflammatory activation. Cytosolic phospholipase A2 (cPLA2) and cyclo-oxygenase-2 (COX-2) are the key enzymes in the metabolism of polyunsaturated fatty acids (PUFAs), which in turn may play an important role in inflammation and somatic symptoms in depression. This study investigated the effects of BanI polymorphism of cPLA2 gene and COX-2 rs4648308 genotypes on somatic symptoms and inflammatory marker in patients with MDD. Eighty-two patients with MDD were assessed for their psychopathology including psychiatric and somatic symptoms, BanI polymorphism of cPLA2 and COX-2 rs4648308 genotypes and CRP levels. The results revealed that MDD patients with the cPLA2 BanI GG genotypes had higher somatic symptoms and higher levels of C-reactive protein (CRP), while no differences were found among the COX-2 rs4648308 genotypes. Inflammatory process, such as arachidonic acid cascade pathway, might help explain the effect of cPLA2 BanI polymorphism on the somatic symptoms, and may be a potential target for future investigation on treatment for MDD with somatic symptoms. However, the interpretation of the findings in this study is limited since we analyzed the data from a subset data from a larger study.

The Chinese Version of the Brief Assessment of Cognition in Schizophrenia: Data of a Large-Scale Mandarin-Speaking Population.

OBJECTIVE: The Brief Assessment of Cognition in Schizophrenia (BACS) is a cognitive assessment tool used to measure the broad aspects of cognition that are most frequently impaired in patients with schizophrenia. This study aims to develop the normative data of the Chinese version of the BACS among the Mandarin-speaking population. METHOD: This cross-sectional study included 382 healthy participants (age range: 19-79 years; mean age: 48.0 ± 16.7 years, 47.6% men) in Taiwan, who were evaluated with the BACS. Means and standard deviations of subtests and composite scores were arranged by age group and gender. The Z-scores calculated based on the U.S. norms were compared to our scores based on the norms established in this study. RESULTS: The raw scores of all the BACS tests (verbal memory, digit sequencing, token motor test, verbal fluency, symbol coding, and Tower of London) were negatively correlated with participants' age. Women were superior to men in verbal memory, but inferior to them in executive function. Furthermore, applying the U.S. norms of the BACS to determine the performance of the Chinese BACS results in bias with regard to verbal memory, token motor test, verbal fluency, symbol coding, Tower of London and composite score. CONCLUSIONS: These findings demonstrate that directly applying western cognitive norms to a Mandarin-speaking population can cause biased interpretations. The results of this study can be an important reference for clinical settings and research related to cognitive assessments in Mandarin-speaking Chinese populations.

Validation of the Chinese version of Brief Assessment of Cognition in Schizophrenia.

OBJECTIVE: A test battery that measures cognitive function impairment in patients with schizophrenia, the Brief Assessment of Cognition in Schizophrenia (BACS), has been translated into various languages and validated. This study aimed to test the reliability and validity of the Chinese version of the BACS in a Chinese-speaking population. METHODS: All participants in this study (66 patients with schizophrenia [mean age: 41.2 years, 57.6% male] and 66 age- and sex-matched healthy controls) were from Taiwan and assessed using the BACS and the University of California, San Diego (UCSD) Performance-Based Skills Assessment, Brief Version (UPSA-B). Thirty-eight of the 66 patients with schizophrenia received a reassessment using the BACS. RESULTS: The BACS had good test-retest reliability, and all BACS subtests had statistically insignificant practice effects. Principal components analysis demonstrated that a one-factor solution best fits our dataset (60.9% of the variance). In both patients and controls, the BACS composite scores were positively correlated with all BACS subscales (P<0.001) and UPSA-B scales (P<0.001). Furthermore, all BACS subtests (verbal memory, working memory, motor speed, verbal fluency, attention and processing speed, and executive function) significantly differentiated patients with schizophrenia from healthy controls (P<0.001), and the BACS composite score had the best discriminative validity (P<0.001). CONCLUSION: The Chinese version of the BACS exhibits satisfactory psychometric properties, including high test-retest reliability, high internal consistency, acceptable concurrent validity, and good discriminant validity. We suggest that the BACS is a reliable and practical tool for assessing cognitive function in patients with schizophrenia.

Differences in Clinical Features of Methamphetamine Users with Persistent Psychosis and Patients with Schizophrenia.

BACKGROUND: Methamphetamine exerts neurotoxic effects and elicits psychotic symptoms. This study attempted to compare clinical differences between methamphetamine users with persistent psychosis (MAP) and patients with schizophrenia. In addition, we examined the discrimination validity by using symptom clusters to differentiate between MAP and schizophrenia. METHODS: We enrolled 53 MAP patients and 53 patients with schizophrenia. The psychopathology of participants was assessed using the Chinese version of the Diagnostic Interview for Genetic Studies and the 18-item Brief Psychiatric Rating Scale. Logistic regression was used to examine the predicted probability scores of different symptom combinations on discriminating between MAP and schizophrenia. The receiver operating characteristic (ROC) analyses and area under the curve (AUC) were further applied to examine the discrimination validity of the predicted probability scores on differentiating between MAP and schizophrenia. RESULTS: We found that MAP and schizophrenia demonstrated similar patterns of delusions. Compared to patients with schizophrenia, MAP experienced significantly higher proportions of visual hallucinations and of somatic or tactile hallucinations. However, MAP exhibited significantly lower severity in conceptual disorganization, mannerism/posturing, blunted affect, emotional withdrawal, and motor retardation compared to patients with schizophrenia. The ROC analysis showed that a predicted probability score combining the aforementioned 7 items of symptoms could significantly differentiate between MAP and schizophrenia (AUC = 0.77). CONCLUSION: Findings in the current study suggest that nuanced differences might exist in the clinical presentation of secondary psychosis (MAP) and primary psychosis (schizophrenia). Combining the symptoms as a whole may help with differential diagnosis for MAP and schizophrenia.

Regulatory circuit rewiring and functional divergence of the duplicate admp genes in dorsoventral axial patterning.

The spatially opposed expression of Antidorsalizing morphogenetic protein (Admp) and BMP signals controls dorsoventral (DV) polarity across Bilateria and hence represents an ancient regulatory circuit. Here, we show that in addition to the conserved admp1 that constitutes the ancient circuit, a second admp gene (admp2) is present in Ambulacraria (Echinodermata+Hemichordata) and two marine worms belonging to Xenoturbellida and Acoelomorpha. The phylogenetic distribution implies that the two admp genes were duplicated in the Bilaterian common ancestor and admp2 was subsequently lost in chordates and protostomes. We show that the ambulacrarian admp1 and admp2 are under opposite transcriptional control by BMP signals and knockdown of Admps in sea urchins impaired their DV polarity. Over-expression of either Admps reinforced BMP signaling but resulted in different phenotypes in the sea urchin embryo. Our study provides an excellent example of signaling circuit rewiring and protein functional changes after gene duplications.

Neurocognitive Profiles of Methamphetamine Users: Comparison of Those With or Without Concomitant Ketamine Use.

OBJECTIVE: Methamphetamine (MAMP) and ketamine are neurotoxic drugs whose chronic use has been linked with a cognitive decline in some users. This paper aims to assess the possible effect of concomitant ketamine use on the neurocognitive performance of MAMP users. METHODS: This study divides 42 MAMP users into MAMP users who use ketamine (MAMP+K, n = 16) and MAMP users who do not use ketamine (MAMP-K, n = 26). The performance of these two groups was compared using the Brief Assessment of Cognition in Schizophrenia (BACS), Conners' Continuous Performance Tests (CPT), the Wisconsin Card Sorting Test (WCST), the Iowa Gambling Task (IGT), and the Barratt Impulsiveness Scale (BIS). RESULTS: In comparison to the MAMP-K group, the MAMP+K group showed worse performances in verbal fluency, executive function and composite score in BACS; worse performances in total errors, perseverative errors, nonperseverative errors and conceptual level response in WCST; and greater levels of total scores and novelty-seeking in BIS. Neither the attention function evaluated with CPT nor the decision-making behavior evaluated with IGT was associated with previous ketamine use. CONCLUSION: This study detected worse executive function and higher impulsivity level among MAMP users with additional ketamine use versus their counterparts without ketamine use. Further studies with a longitudinal design and a large sample size are necessary to clarify the connection between cognitive deficits and concomitant use of MAMP and ketamine.

Hemichordate genomes and deuterostome origins.

Acorn worms, also known as enteropneust (literally, 'gut-breathing') hemichordates, are marine invertebrates that share features with echinoderms and chordates. Together, these three phyla comprise the deuterostomes. Here we report the draft genome sequences of two acorn worms, Saccoglossus kowalevskii and Ptychodera flava. By comparing them with diverse bilaterian genomes, we identify shared traits that were probably inherited from the last common deuterostome ancestor, and then explore evolutionary trajectories leading from this ancestor to hemichordates, echinoderms and chordates. The hemichordate genomes exhibit extensive conserved synteny with amphioxus and other bilaterians, and deeply conserved non-coding sequences that are candidates for conserved gene-regulatory elements. Notably, hemichordates possess a deuterostome-specific genomic cluster of four ordered transcription factor genes, the expression of which is associated with the development of pharyngeal 'gill' slits, the foremost morphological innovation of early deuterostomes, and is probably central to their filter-feeding lifestyle. Comparative analysis reveals numerous deuterostome-specific gene novelties, including genes found in deuterostomes and marine microbes, but not other animals. The putative functions of these genes can be linked to physiological, metabolic and developmental specializations of the filter-feeding ancestor.

Predictors of Relapse and Dropout During a 12-Week Relapse Prevention Program for Methamphetamine Users.

In this research, the possible neuropsychological predictors of relapse and dropout of group cognitive behavioral therapy (CBT) for methamphetamine (MA) users were explored. Participants were 42 MA users sentenced by the judicial system to take part in an out-patient relapse prevention program for MA abuse and dependence that employs a CBT model once a week over the course of 12 weeks. Baseline neuropsychological functions were evaluated with the Conners' Continuous Performance Test, Wisconsin Card Sorting Test, Iowa Gambling Task, and Barratt Impulsiveness Scale. All participants had to submit to urine drug tests every week. Of the 42 participants, 69.0% had a MA positive urine screening result at least once throughout the program (relapse), while 40.5% dropped out of the treatment program prior to its completion. Short duration of MA abstinence at baseline and poor attention predicted relapse. Predictors of dropout included being unmarried and having risky decision making. Findings may be helpful for clinicians, who can screen for the aforementioned risk factors and provide strategies for high-risk patients to help prevent relapse and dropout among MA users in treatment programs.

Evolution of extreme stomach pH in bilateria inferred from gastric alkalization mechanisms in basal deuterostomes.

The stomachs of most vertebrates operate at an acidic pH of 2 generated by the gastric H(+)/K(+)-ATPase located in parietal cells. The acidic pH in stomachs of vertebrates is believed to aid digestion and to protect against environmental pathogens. Little attention has been placed on whether acidic gastric pH regulation is a vertebrate character or a deuterostome ancestral trait. Here, we report alkaline conditions up to pH 10.5 in the larval digestive systems of ambulacraria (echinoderm + hemichordate), the closest relative of the chordate. Microelectrode measurements in combination with specific inhibitors for acid-base transporters and ion pumps demonstrated that the gastric alkalization machinery in sea urchin larvae is mainly based on direct H(+) secretion from the stomach lumen and involves a conserved set of ion pumps and transporters. Hemichordate larvae additionally utilized HCO3(-) transport pathways to generate even more alkaline digestive conditions. Molecular analyses in combination with acidification experiments supported these findings and identified genes coding for ion pumps energizing gastric alkalization. Given that insect larval guts were also reported to be alkaline, our discovery raises the hypothesis that the bilaterian ancestor utilized alkaline digestive system while the vertebrate lineage has evolved a strategy to strongly acidify their stomachs.