[Nursing Digital Transformation: An Example of an Electronic Whiteboard in a Regional Hospital in Central Taiwan].

The electronic whiteboard system is an important part of smart medical care. This system has been digitized and upgraded gradually over time, and now functions as a dashboard, incorporating sound effects, touch control, image display, face recognition, and other functions that maximize usage efficiency. In hospitals, electronic whiteboards are specialized for dedicated use in one of two areas: nursing stations and wards. Those used in nursing stations may upload data into the medical information system based on departmental and institutional requirements. Systems are built to the specific needs of different clinical departments and thus differ widely in terms of settings and functionality. Therefore, hospitals should promote regular communication among doctors, nurses, and patients.

Metabolic activity of the left and right atria are differentially altered in patients with atrial fibrillation and LV dysfunction.

BACKGROUND: Alterations in atrial metabolism may play a role in the perpetuation of atrial fibrillation (AF). This study sought to compare 18F-fluorodeoxyglucose (FDG) uptake on PET, in patients with LV dysfunction versus those without AF. METHODS: Seventy-two patients who underwent myocardial viability assessment were evaluated. AF patients (36) had persistent or permanent AF based on history and ECG. Patients without AF (36) were matched to AF patients based on sex, diabetes, age, and LVEF. Maximum and mean FDG Standard Uptake Values (SUV) in the left atrial (LA) wall and right atrial (RA) wall were measured. Tissue-to-blood ratios (TBR) were calculated as atrial wall to blood-pool activity. Atrial volumes were measured by echocardiography. RESULTS: Maximum and mean FDG SUV and TBRs were significantly increased in the RA (but not the LA) of patients with AF compared to those without (P < 0.01). When accounting for changes in atrial volume, the presence of AF remained a significant predictor of higher RAMAX, but not RAMEAN FDG uptake. CONCLUSION: In patients with LV dysfunction from ischemic cardiomyopathy, LA and RA glucose metabolism are differentially altered in those with persistent atrial fibrillation. Further investigations should elucidate the temporal relationship between AF and glucose metabolic changes, as a potential target for therapy.

Kapitza-Dirac Blockade: A Universal Tool for the Deterministic Preparation of Non-Gaussian Oscillator States.

Harmonic oscillators count among the most fundamental quantum systems with important applications in molecular physics, nanoparticle trapping, and quantum information processing. Their equidistant energy level spacing is often a desired feature, but at the same time a challenge if the goal is to deterministically populate specific eigenstates. Here, we show how interference in the transition amplitudes in a bichromatic laser field can suppress the sequential climbing of harmonic oscillator states (Kapitza-Dirac blockade) and achieve selective excitation of energy eigenstates, cat states, and other non-Gaussian states. This technique can transform the harmonic oscillator into a coherent two-level system or be used to build a large-momentum-transfer beam splitter for matter waves. To illustrate the universality of the concept, we discuss feasible experiments that cover many orders of magnitude in mass, from single electrons over large molecules to dielectric nanoparticles.

Tokyo Guidelines 2018: initial management of acute biliary infection and flowchart for acute cholangitis.

The initial management of patients with suspected acute biliary infection starts with the measurement of vital signs to assess whether or not the situation is urgent. If the case is judged to be urgent, initial medical treatment should be started immediately including respiratory/circulatory management if required, without waiting for a definitive diagnosis. The patient's medical history is then taken; an abdominal examination is performed; blood tests, urinalysis, and diagnostic imaging are carried out; and a diagnosis is made using the diagnostic criteria for cholangitis/cholecystitis. Once the diagnosis has been confirmed, initial medical treatment should be started immediately, severity should be assessed according to the severity grading criteria for acute cholangitis/cholecystitis, and the patient's general status should be evaluated. For mild acute cholangitis, in most cases initial treatment including antibiotics is sufficient, and most patients do not require biliary drainage. However, biliary drainage should be considered if a patient does not respond to initial treatment. For moderate acute cholangitis, early endoscopic or percutaneous transhepatic biliary drainage is indicated. If the underlying etiology requires treatment, this should be provided after the patient's general condition has improved; endoscopic sphincterotomy and subsequent choledocholithotomy may be performed together with biliary drainage. For severe acute cholangitis, appropriate respiratory/circulatory management is required. Biliary drainage should be performed as soon as possible after the patient's general condition has been improved by initial treatment and respiratory/circulatory management. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Tokyo Guidelines 2018: management strategies for gallbladder drainage in patients with acute cholecystitis (with videos).

Since the publication of the Tokyo Guidelines in 2007 and their revision in 2013, appropriate management for acute cholecystitis has been more clearly established. Since the last revision, several manuscripts, especially for alternative endoscopic techniques, have been reported; therefore, additional evaluation and refinement of the 2013 Guidelines is required. We describe a standard drainage method for surgically high-risk patients with acute cholecystitis and the latest developed endoscopic gallbladder drainage techniques described in the updated Tokyo Guidelines 2018 (TG18). Our study confirmed that percutaneous transhepatic gallbladder drainage should be considered the first alternative to surgical intervention in surgically high-risk patients with acute cholecystitis. Also, endoscopic transpapillary gallbladder drainage or endoscopic ultrasound-guided gallbladder drainage can be considered in high-volume institutes by skilled endoscopists. In the endoscopic transpapillary approach, either endoscopic naso-gallbladder drainage or gallbladder stenting can be considered for gallbladder drainage. We also introduce special techniques and the latest outcomes of endoscopic ultrasound-guided gallbladder drainage studies. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Tokyo Guidelines 2018: surgical management of acute cholecystitis: safe steps in laparoscopic cholecystectomy for acute cholecystitis (with videos).

In some cases, laparoscopic cholecystectomy (LC) may be difficult to perform in patients with acute cholecystitis (AC) with severe inflammation and fibrosis. The Tokyo Guidelines 2018 (TG18) expand the indications for LC under difficult conditions for each level of severity of AC. As a result of expanding the indications for LC to treat AC, it is absolutely necessary to avoid any increase in bile duct injury (BDI), particularly vasculo-biliary injury (VBI), which is known to occur at a certain rate in LC. Since the Tokyo Guidelines 2013 (TG13), an attempt has been made to assess intraoperative findings as objective indicators of surgical difficulty; based on expert consensus on these difficulty indicators, bail-out procedures (including conversion to open cholecystectomy) have been indicated for cases in which LC for AC is difficult to perform. A bail-out procedure should be chosen if, when the Calot's triangle is appropriately retracted and used as a landmark, a critical view of safety (CVS) cannot be achieved because of the presence of nondissectable scarring or severe fibrosis. We propose standardized safe steps for LC to treat AC. To achieve a CVS, it is vital to dissect at a location above (on the ventral side of) the imaginary line connecting the base of the left medial section (Segment 4) and the roof of Rouvière's sulcus and to fulfill the three criteria of CVS before dividing any structures. Achieving a CVS prevents the misidentification of the cystic duct and the common bile duct, which are most commonly confused. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Tokyo Guidelines 2018: flowchart for the management of acute cholecystitis.

We propose a new flowchart for the treatment of acute cholecystitis (AC) in the Tokyo Guidelines 2018 (TG18). Grade III AC was not indicated for straightforward laparoscopic cholecystectomy (Lap-C). Following analysis of subsequent clinical investigations and drawing on Big Data in particular, TG18 proposes that some Grade III AC can be treated by Lap-C when performed at advanced centers with specialized surgeons experienced in this procedure and for patients that satisfy certain strict criteria. For Grade I, TG18 recommends early Lap-C if the patients meet the criteria of Charlson comorbidity index (CCI) ≤5 and American Society of Anesthesiologists physical status classification (ASA-PS) ≤2. For Grade II AC, if patients meet the criteria of CCI ≤5 and ASA-PS ≤2, TG18 recommends early Lap-C performed by experienced surgeons; and if not, after medical treatment and/or gallbladder drainage, Lap-C would be indicated. TG18 proposes that Lap-C is indicated in Grade III patients with strict criteria. These are that the patients have favorable organ system failure, and negative predictive factors, who meet the criteria of CCI ≤3 and ASA-PS ≤2 and who are being treated at an advanced center (where experienced surgeons practice). If the patient is not considered suitable for early surgery, TG18 recommends early/urgent biliary drainage followed by delayed Lap-C once the patient's overall condition has improved. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Tokyo Guidelines 2018: antimicrobial therapy for acute cholangitis and cholecystitis.

Antimicrobial therapy is a mainstay of the management for patients with acute cholangitis and/or cholecystitis. The Tokyo Guidelines 2018 (TG18) provides recommendations for the appropriate use of antimicrobials for community-acquired and healthcare-associated infections. The listed agents are for empirical therapy provided before the infecting isolates are identified. Antimicrobial agents are listed by class-definitions and TG18 severity grade I, II, and III subcategorized by clinical settings. In the era of emerging and increasing antimicrobial resistance, monitoring and updating local antibiograms is underscored. Prudent antimicrobial usage and early de-escalation or termination of antimicrobial therapy are now important parts of decision-making. What is new in TG18 is that the duration of antimicrobial therapy for both acute cholangitis and cholecystitis is systematically reviewed. Prophylactic antimicrobial usage for elective endoscopic retrograde cholangiopancreatography is no longer recommended and the section was deleted in TG18. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Tokyo Guidelines 2018: management bundles for acute cholangitis and cholecystitis.

Management bundles that define items or procedures strongly recommended in clinical practice have been used in many guidelines in recent years. Application of these bundles facilitates the adaptation of guidelines and helps improve the prognosis of target diseases. In Tokyo Guidelines 2013 (TG13), we proposed management bundles for acute cholangitis and cholecystitis. Here, in Tokyo Guidelines 2018 (TG18), we redefine the management bundles for acute cholangitis and cholecystitis. Critical parts of the bundles in TG18 include the diagnostic process, severity assessment, transfer of patients if necessary, and therapeutic approach at each time point. Observance of these items and procedures should improve the prognosis of acute cholangitis and cholecystitis. Studies are now needed to evaluate the dissemination of these TG18 bundles and their effectiveness. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Tokyo Guidelines 2018: diagnostic criteria and severity grading of acute cholangitis (with videos).

Although the diagnostic and severity grading criteria on the 2013 Tokyo Guidelines (TG13) are used worldwide as the primary standard for management of acute cholangitis (AC), they need to be validated through implementation and assessment in actual clinical practice. Here, we conduct a systematic review of the literature to validate the TG13 diagnostic and severity grading criteria for AC and propose TG18 criteria. While there is little evidence evaluating the TG13 criteria, they were validated through a large-scale case series study in Japan and Taiwan. Analyzing big data from this study confirmed that the diagnostic rate of AC based on the TG13 diagnostic criteria was higher than that based on the TG07 criteria, and that 30-day mortality in patients with a higher severity based on the TG13 severity grading criteria was significantly higher. Furthermore, a comparison of patients treated with early or urgent biliary drainage versus patients not treated this way showed no difference in 30-day mortality among patients with Grade I or Grade III AC, but significantly lower 30-day mortality in patients with Grade II AC who were treated with early or urgent biliary drainage. This suggests that the TG13 severity grading criteria can be used to identify Grade II patients whose prognoses may be improved through biliary drainage. The TG13 severity grading criteria may therefore be useful as an indicator for biliary drainage as well as a predictive factor when assessing the patient's prognosis. The TG13 diagnostic and severity grading criteria for AC can provide results quickly, are minimally invasive for the patients, and are inexpensive. We recommend that the TG13 criteria be adopted in the TG18 guidelines and used as standard practice in the clinical setting. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Tokyo Guidelines 2018: diagnostic criteria and severity grading of acute cholecystitis (with videos).

The Tokyo Guidelines 2013 (TG13) for acute cholangitis and cholecystitis were globally disseminated and various clinical studies about the management of acute cholecystitis were reported by many researchers and clinicians from all over the world. The 1st edition of the Tokyo Guidelines 2007 (TG07) was revised in 2013. According to that revision, the TG13 diagnostic criteria of acute cholecystitis provided better specificity and higher diagnostic accuracy. Thorough our literature search about diagnostic criteria for acute cholecystitis, new and strong evidence that had been released from 2013 to 2017 was not found with serious and important issues about using TG13 diagnostic criteria of acute cholecystitis. On the other hand, the TG13 severity grading for acute cholecystitis has been validated in numerous studies. As a result of these reviews, the TG13 severity grading for acute cholecystitis was significantly associated with parameters including 30-day overall mortality, length of hospital stay, conversion rates to open surgery, and medical costs. In terms of severity assessment, breakthrough and intensive literature for revising severity grading was not reported. Consequently, TG13 diagnostic criteria and severity grading were judged from numerous validation studies as useful indicators in clinical practice and adopted as TG18/TG13 diagnostic criteria and severity grading of acute cholecystitis without any modification. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47. Related clinical questions and references are also included.

Delphi consensus on bile duct injuries during laparoscopic cholecystectomy: an evolutionary cul-de-sac or the birth pangs of a new technical framework?

Bile duct injury (BDI) during laparoscopic cholecystectomy remains a serious iatrogenic surgical complication. BDI most often occurs as a result of misidentification of the anatomy; however, clinical evidence on its precise mechanism and surgeons' perceptions is scarce. Surgeons from Japan, Korea, Taiwan, and the USA, etc. (n = 614) participated in a questionnaire regarding their BDI experience and near-misses; and perceptions on landmarks, intraoperative findings, and surgical techniques. Respondents voted for a Delphi process and graded each item on a five-point scale. The consensus was built when ≥80% of overall responses were 4 or 5. Response rates for the first- and second-round Delphi were 60.6% and 74.9%, respectively. Misidentification of local anatomy accounted for 76.2% of BDI. Final consensus was reached on: (1) Effective retraction of the gallbladder, (2) Always obtaining critical view of safety, and (3) Avoiding excessive use of electrocautery/clipping as vital procedures; and (4) Calot's triangle area and (5) Critical view of safety as important landmarks. For (6) Impacted gallstone and (7) Severe fibrosis/scarring in Calot's triangle, bail-out procedures may be indicated. A consensus was reached among expert surgeons on relevant landmarks and intraoperative findings and appropriate surgical techniques to avoid BDI.

Correlation of Chitinase 3-Like 1 Single Nucleotide Polymorphisms with Hepatocellular Carcinoma in Taiwan.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer death in Taiwan. Multiple risk factors, such as chronic hepatitis B or C virus infection, carcinogen exposure, cirrhosis, and various single-nucleotide polymorphisms (SNPs), are considered to contribute to hepatocarcinogenesis. Chitinase-3-like protein 1 (CHI3L1), a biomarker implicated in inflammation and tissue remodeling, plays a promoting role in angiogenesis, antiapoptosis, and cell proliferation. This study investigated the role of CHI3L1 SNPs in HCC susceptibility and clinicopathology. Real-time polymerase chain reaction was used to analyze four SNPs of CHI3L1 in 343 patients with HCC and 686 cancer-free controls. We found associations with HCC susceptibility in CHI3L1 rs880633 polymorphism carriers with genotypes (TC+CC). We observed that HCC patients had lower frequencies of CHI3L1 rs6691378 polymorphisms with the variant genotype GA+AA than the wild-type carriers with distant metastasis and positive HBsAg did. In 200 HBsAg negative HCC patients, we observed that the CHI3L1 rs4950928 polymorphisms carriers with the variant genotype CG+GG had higher frequencies of vascular invasion. Finally, carriers of CHI3L1 rs6691378 and 10399805 polymorphisms with the variant genotypes GA+AA showed lower levels of alpha-fetoprotein in HCC laboratory status. In conclusion, our results indicate that patients with CHI3L1 rs880633 variant genotypes TC+CC are at a higher risk of HCC. CHI3L1 polymorphisms rs880633 or rs4950928 may be potential candidates for predicting poor HCC prognosis and clinical status.

An opportunity in difficulty: Japan-Korea-Taiwan expert Delphi consensus on surgical difficulty during laparoscopic cholecystectomy.

BACKGROUND: We previously identified 25 intraoperative findings during laparoscopic cholecystectomy (LC) as potential indicators of surgical difficulty per nominal group technique. This study aimed to build a consensus among expert LC surgeons on the impact of each item on surgical difficulty. METHODS: Surgeons from Japan, Korea, and Taiwan (n = 554) participated in a Delphi process and graded the 25 items on a seven-stage scale (range, 0-6). Consensus was defined as (1) the interquartile range (IQR) of overall responses ≤2 and (2) ≥66% of the responses concentrated within a median ± 1 after stratification by workplace and LC experience level. RESULTS: Response rates for the first and the second-round Delphi were 92.6% and 90.3%, respectively. Final consensus was reached for all the 25 items. 'Diffuse scarring in the Calot's triangle area' in the 'Factors related to inflammation of the gallbladder' category had the strongest impact on surgical difficulty (median, 5; IQR, 1). Surgeons agreed that the surgical difficulty increases as more fibrotic change and scarring develop. The median point for each item was set as the difficulty score. CONCLUSIONS: A Delphi consensus was reached among expert LC surgeons on the impact of intraoperative findings on surgical difficulty.

The "right" way is not always popular: comparison of surgeons' perceptions during laparoscopic cholecystectomy for acute cholecystitis among experts from Japan, Korea and Taiwan.

BACKGROUND: Generally, surgeons' perceptions of surgical safety are based on experience and institutional policy. Our recent pilot survey demonstrated that the acceptable duration of surgery and criteria for open conversion during laparoscopic cholecystectomy (LC) vary among workplaces. METHODS: A web-based survey was distributed to 554 expert LC surgeons in Japan, Korea, and Taiwan. The questionnaire covered LC experience, safety measures and recognition of landmarks, decision-making regarding conversion to open/partial cholecystectomy and the implications of this decision. Overall responses were compared among nations, and then stratified by LC experience level (lifetime cases 200-499, 500-999, and ≥1,000). RESULTS: The response rate was 92.6% (513/554); 67 surgeons with ≤199 LCs were excluded, and responses from 446 surgeons were analyzed. We observed significant differences among nations on almost all questions. Differences that remained after stratification by LC experience were on questions related to acceptable duration of surgery, adoption rates of intraoperative cholangiography, the "critical view of safety" technique, identification of Rouvière's sulcus, recognition of the SS-Inner layer theory, and intraoperative judgment to abandon conventional LC. CONCLUSIONS: Even among experts, surgeons' perceptions during LC are workplace-dependent. A novel grading system of surgical difficulty and standardized LC procedures are paramount to generate high-level evidence.

What are the appropriate indicators of surgical difficulty during laparoscopic cholecystectomy? Results from a Japan-Korea-Taiwan multinational survey.

BACKGROUND: Serious complications continue to occur in laparoscopic cholecystectomy (LC). The commonly used indicators of surgical difficulty such as the duration of surgery are insufficient because they are surgeon and institution dependent. We aimed to identify appropriate indicators of surgical difficulty during LC. METHODS: A total of 26 Japanese expert LC surgeons discussed using the nominal group technique (NGT) to generate a list of intraoperative findings that contribute to surgical difficulty. Thereafter, a survey was circulated to 61 experts in Japan, Korea, and Taiwan. The questionnaire addressed LC experience, surgical strategy, and perceptions of 30 intraoperative findings listed by the NGT. RESULTS: The response rate of the survey was 100%. There was a statistically significant difference among nations regarding the duration of surgery and adoption rate of safety measures and recognition of landmarks. The criteria for conversion to an open or subtotal cholecystectomy were at the discretion of each surgeon. In contrast, perceptions of the impact of 30 intraoperative findings on surgical difficulty (categorized by factors related to inflammation and additional findings of the gallbladder and other intra-abdominal factors) were consistent among surgeons. CONCLUSIONS: Intraoperative findings are objective and considered to be appropriate indicators of surgical difficulty during LC.

Efficacy and effectiveness of depot versus oral antipsychotics in schizophrenia: synthesizing results across different research designs.

OBJECTIVE: Nonadherence is a major challenge in schizophrenia treatment. While long-acting (depot) antipsychotic medications are often recommended to address adherence problems, evidence on the comparative effectiveness of depot versus oral antipsychotics is inconsistent. We hypothesize that this inconsistency could be due to systematic differences in study design. This review evaluates the effect of study design on the comparative effectiveness of antipsychotic formulations. The optimal use of different antipsychotic formulations in a general clinical setting depends on better understanding of the underlying reasons for differences in effectiveness across research designs. DATA SOURCES: A PubMed literature review targeted English-language studies (2000-2011) with information on relapse, hospitalization, or all-cause discontinuation for depot and oral antipsychotic treatment arms in schizophrenia. The time frame was chosen to reflect research focused on the newer generation of antipsychotic agents. The search required at least 1 term from each of the following categories: (1) schizophrenia; (2) inject, injection, injectable, injectables, injected, depot, long-acting; and (3) iloperidone, fluphenazine, haloperidol, paliperidone, risperidone, olanzapine, asenapine, flupentixol, flupenthixol, lurasidone, clopenthixol, fluspirilene, zuclopentixol, zuclopenthixol. STUDY SELECTION: Thirteen relevant studies were identified by 2 independent reviewers; these studies included information on 19 depot-oral comparisons. DATA EXTRACTION: Age- and gender-adjusted risk ratios (RRs) (depot/oral) were calculated for the identified endpoints and pooled by study design (randomized controlled trial [RCT], prospective observational, and retrospective observational). Meta-analysis with random effects was used to estimate the pooled RRs, by study design. Average conversion factors between study designs were calculated as the ratios of pooled RRs. RESULTS: Meta-analysis of adjusted endpoints showed no apparent benefit of depot over oral formulations in RCTs, with an RR of 0.89 (P = .416). In contrast, there was a significant advantage for depot formulations in other study designs (prospective RR = 0.62 [P < .001]; retrospective RR = 0.56 [P < .001]). These imply conversion factors of 1.43 and 1.59 between RCTs and prospective and retrospective designs, respectively. CONCLUSIONS: The comparative effectiveness of antipsychotic formulations is sensitive to research design. Depot formulations displayed significant advantages in nonrandomized observational studies, whereas in RCTs no difference was observed. The estimated conversion factors may facilitate comparison across studies.

New class of HIV-1 integrase (IN) inhibitors with a dual mode of action.

tert-Butoxy-(4-phenyl-quinolin-3-yl)-acetic acids (tBPQA) are a new class of HIV-1 integrase (IN) inhibitors that are structurally distinct from IN strand transfer inhibitors but analogous to LEDGINs. LEDGINs are a class of potent antiviral compounds that interacts with the lens epithelium-derived growth factor (LEDGF) binding pocket on IN and were identified through competition binding against LEDGF. LEDGF tethers IN to the host chromatin and enables targeted integration of viral DNA. The prevailing understanding of the antiviral mechanism of LEDGINs is that they inhibit LEDGF binding to IN, which prevents targeted integration of HIV-1. We showed that in addition to the properties already known for LEDGINs, the binding of tBPQAs to the IN dimer interface inhibits IN enzymatic activity in a LEDGF-independent manner. Using the analysis of two long terminal repeat junctions in HIV-infected cells, we showed that the inhibition by tBPQAs occurs at or prior to the viral DNA 3'-processing step. Biochemical studies revealed that this inhibition operates by compound-induced conformational changes in the IN dimer that prevent proper assembly of IN onto viral DNA. For the first time, tBPQAs were demonstrated to be allosteric inhibitors of HIV-1 IN displaying a dual mode of action: inhibition of IN-viral DNA assembly and inhibition of IN-LEDGF interaction.

p21-Activated kinases 1 and 3 control brain size through coordinating neuronal complexity and synaptic properties.

The molecular mechanisms that coordinate postnatal brain enlargement, synaptic properties, and cognition remain an enigma. Here, we demonstrate that neuronal complexity controlled by p21-activated kinases (PAKs) is a key determinant for postnatal brain enlargement and synaptic properties. We showed that double-knockout (DK) mice lacking both PAK1 and PAK3 were born healthy, with normal brain size and structure, but severely impaired in postnatal brain growth, resulting in a dramatic reduction in brain volume. Remarkably, the reduced brain size was accompanied by minimal changes in total cell count, due to a significant increase in cell density. However, the DK neurons have smaller soma, markedly simplified dendritic arbors/axons, and reduced synapse density. Surprisingly, the DK mice had elevated basal synaptic responses due to enhanced individual synaptic potency but were severely impaired in bidirectional synaptic plasticity. The actions of PAK1 and PAK3 are possibly mediated by cofilin-dependent actin regulation, because the activity of cofilin and the properties of actin filaments were altered in the DK mice. These results reveal an essential in vivo role of PAK1 and PAK3 in coordinating neuronal complexity and synaptic properties and highlight the critical importance of dendrite/axon growth in dictating postnatal brain growth and attainment of normal brain size and function.