National health insurance impact on malnutrition in under-five years old children in Indonesia

Background

The premium-based National Health Insurance Program under Jaminan Kesehatan Nasional (JKN), has been launched in 2014, although it lacks evaluation of the benefits, particularly on clinical outcomes-based. This study aimed to assess the impact of JKN possession on nutrition status among under-five years old children.

Methods

A Cross-Sectional Study was conducted during January-September 2019 in Balikpapan, Indonesia to assess the impact of JKN in the nutrition status of this specific group. Primary data (socio-demographic, feeding pattern, basic knowledge of nutrition and Health Insurance ownership) has retrieved through validated questionnaires from the parents and/or the guardian, followed by anthropometry measurement (Weight per Age Z-Score) to determine the nutrition status. Bivariate analysis was conducted to identify the confounder. Binary Logistic Regression was performed to determine the impact of JKN health insurance on the nutrition status among the target population

Results

As 62 from 312 (19.87%) children fall <-2 Z-Score (Underweight) whereas 5 children were overweight (>2 Zscore) and 2 children were obese (>3 Z Score). Only 77 (24.68%) children have JKN. The education of both parents was associated with nutrition status but no difference in knowledge regarding nutrition and identifying nutritional disease. Various feeding patterns (Breastfeeding status, vitamin A status, and snack intake) were not potential confounders. Adjusted by birth weight and history of disease within 6 months, child who possess Health Insurance (JKN) tend to have a normal weight child up to 1.998 times (AOR = 1.998, 95% CI 1.056-3.780 p = 0.033) compared to underweight, but no significant finding was found between Health Insurance and children with normal and overweight/obese children, adjusted by birthweight (AOR = 3.091, 95% CI 0.639-14.692 p = 0.161)

Conclusions

This study illustrated the significant benefit of JKN to prevent undernourished event but not overnutrition.

Key messages

National Health Insurance Coverage provides benefit on malnutrition prevention in under-five years old children. Children covered with National Health Insurance will unlikely get undernourished but no significant finding in overnourished prevention.

48 hours public response to Corona epidemic status in Indonesia. Perceived risk and panic buying

Background

President of Indonesia, Joko Widodo has announced two confirmed CoVid-19 cases who live in Depok, West Java, on Monday, March 2nd, 2020. A rapid assessment of public response toward the new status was conducted, focusing on perceived risk and panic buying.

Methodology

A cross-sectional survey was conducted within 48 hours after the announcement through an online questionnaire. A demographic data including, sex, age, education, occupation (medical vs nonmedical), income, health insurance, island domicile (Java vs non-Java), mobility, history of contact with a foreigner, and history of overseas travel within a month. Knowledge regarding Covid 19 was determined by the average score of 38 5-Likert scale questions (5 indicates better knowledge). Perceived risk was measured with a 10-scale question, and panic buying was assessed through an average score of 6 5-Likert scale questions (5 indicates panic buying). Mann-Whitney and Linear regression were performed to identify the associated factors.

Results

As a total of 214 respondents, panic buying was lower (2.28 ± 0.79 on a 5-scale) except for perceived risk (5.91 ± 2.13 on a 10-scale). No difference between medical and nonmedical staff in panic buying (p = 0.619) and perceived risk (p = 0.477) and the domicile of respondents (Java VS nonjava) in panic buying (p = 0.810) and perceived risk (p = 0.101). Younger age, working in a medical field and living in Java are associated with higher perceived risk in the linear model whereas panic buying is solely affected by knowledge (β -1.459. p < 0.001). The respondents agreed that scarcity of single-use components (mean 4.32 out of 5) such as masker and goods inflation particularly groceries (mean 4.31 out of 5) will appear soon

Conclusions

It is important to disseminate the correct information to the public to reduce panic buying. Collaborative action between the government and medical staff should be done particularly in Java as the first locus of CoVid 19 in Indonesia.

Key messages

Knowledge regarding corona virus affects the Panic Buying. An intervention to disseminate the correct information should be done.

To reduce the perceived risk, a rigorous action should be done in Java and a collaborative work between the government and medical staffs should be established.

Artificial Intelligence in Drug-Resistant Tuberculosis Diagnosis. Systematic Review & Meta Analysis

Background

Artificial Intelligence (AI) models possess potential screening or diagnosing Drug-Resistant Tuberculosis. This meta-analysis aimed to elaborate on the performance of AI models in predicting drug-resistant TB compared to the gold standard.

Methods

A systematic search of full-paper articles from Pubmed/MEDLINE and SCOPUS published between January 2005 and April 2020 was conducted. Studies involving whole-genome sequencing or human subject data that used drug-susceptibility test results as a reference standard were retrieved. Hierarchical summary receiver-operating characteristic (HSROC) and bivariate model were performed to calculate pooled sensitivity and specificity. Heterogeneity and publication bias were also assessed.

Results

25 Models form four genome-based studies, four radiology-based studies, and two clinical and demographic-based studies were included. The radiology-based models, mainly built with the Convolutional Neural Network (CNN), possessed pooled sensitivity of 58% (95%CI 50%-65%), and a pooled specificity of 75% (95% CI 47%-91%) for detecting MDR-TB. Genome-based models outperformed other models despite developed with simpler classifiers (CART/GBT/LR). The genome-based studies reached pooled sensitivity of 92% (95%CI 90-93%), pooled specificity of 98 (95% CI 96%-98%) in predicting isoniazid resistance. For predicting rifampicin resistance, the pooled sensitivity and specificity were 93% (95%CI 90%-94%) and 98% (95% CI 96%-98%) respectively. The Artificial Neural Network (ANN) demonstrated superiority rather than the Classification and Regression Tree (CART), and logistic regression (LR) on the clinical and demographic model in predicting drug-resistant TB.

Conclusions

Simple classifier performs better in genomic data whereas the CNN model works best in high-dimensional data, such as radiology images. The ANN model indicates a preferred model for data obtained from clinical and demographic parameters. (PROSPERO number CRD42020167439)

Key messages

Artificial Intelligence model through machine learning and deep learning possess a good diagnostic performance for drug-resistant tuberculosis. Artificial Neural Network model outperforms other technique. The model built from genomic data shows the best performance, followed by model from patient-based data and radiology/imaging data.

Requirements analysis and preliminary design of a robotic assistant for reconstructive microsurgery

Microanastomosis is a microsurgical gesture that involves suturing two very small blood vessels together. This gesture is used in many operations such as avulsed member auto-grafting, pediatric surgery, reconstructive surgery - including breast reconstruction by free flap. When vessels have diameters smaller than one millimeter, hand tremors make movements difficult to control. This paper introduces our preliminary steps towards robotic assistance for helping surgeons to perform microanastomosis in optimal conditions, in order to increase gesture quality and reliability even on smaller diameters. A general needs assessment and an experimental motion analysis were performed to define the requirements of the robot. Geometric parameters of the kinematic structure were then optimized to fulfill specific objectives. A prototype of the robot is currently being designed and built in order to providing a sufficient increase in accuracy without prolonging the duration of the procedure.

Detailed molecular characterisation of acute myeloid leukaemia with a normal karyotype using targeted DNA capture

Advances in sequencing technologies are giving unprecedented insights into the spectrum of somatic mutations underlying acute myeloid leukaemia with a normal karyotype (AML-NK). It is clear that the prognosis of individual patients is strongly influenced by the combination of mutations in their leukaemia and that many leukaemias are composed of multiple subclones, with differential susceptibilities to treatment. Here, we describe a method, employing targeted capture coupled with next-generation sequencing and tailored bioinformatic analysis, for the simultaneous study of 24 genes recurrently mutated in AML-NK. Mutational analysis was performed using open source software and an in-house script (Mutation Identification and Analysis Software), which identified dominant clone mutations with 100% specificity. In each of seven cases of AML-NK studied, we identified and verified mutations in 2-4 genes in the main leukaemic clone. Additionally, high sequencing depth enabled us to identify putative subclonal mutations and detect leukaemia-specific mutations in DNA from remission marrow. Finally, we used normalised read depths to detect copy number changes and identified and subsequently verified a tandem duplication of exons 2-9 of MLL and at least one deletion involving PTEN. This methodology reliably detects sequence and copy number mutations, and can thus greatly facilitate the classification, clinical research, diagnosis and management of AML-NK.

Cytotoxicity screening of surfactant-based shampoos using a multiwell fluorescence scanner: Correlation with Draize eye scores

The irritancy potential of seven shampoos was evaluated by a rapid cytotoxicity assay in cultured human keratinocytes and rat hepatocytes. Loss of cell viability was estimated from increases in propidium iodide fluorescence measured using a multiwell fluorescence scanner. The concentration of shampoo causing a 50% loss of cell viability after 15 min of incubation (V(50)) was determined by probit analysis. Log V(50) measured in human keratinocytes showed a strong negative correlation (r = -0.95; P <0.001) with Draize eye scores in rabbits. Log V(50) measured in rat hepatocytes did not show a statistically significant correlation with Draize eye scores. The results indicate that cytotoxicity screening of human keratinocytes using propidium iodide and a multiwell fluorescence scanner is highly predictive of Draize eye scores for surfactant-containing shampoos.

Host S-nitrosylation inhibits clostridial small molecule-activated glucosylating toxins

The global prevalence of severe Clostridium difficile infection highlights the profound clinical significance of clostridial glucosylating toxins. Virulence is dependent on the autoactivation of a toxin cysteine protease, which is promoted by the allosteric cofactor inositol hexakisphosphate (InsP(6)). Host mechanisms that protect against such exotoxins are poorly understood. It is increasingly appreciated that the pleiotropic functions attributed to nitric oxide (NO), including host immunity, are in large part mediated by S-nitrosylation of proteins. Here we show that C. difficile toxins are S-nitrosylated by the infected host and that S-nitrosylation attenuates virulence by inhibiting toxin self-cleavage and cell entry. Notably, InsP(6)- and inositol pyrophosphate (InsP(7))-induced conformational changes in the toxin enabled host S-nitrosothiols to transnitrosylate the toxin catalytic cysteine, which forms part of a structurally conserved nitrosylation motif. Moreover, treatment with exogenous InsP(6) enhanced the therapeutic actions of oral S-nitrosothiols in mouse models of C. difficile infection. Allostery in bacterial proteins has thus been successfully exploited in the evolutionary development of nitrosothiol-based innate immunity and may provide an avenue to new therapeutic approaches.

ACRIN 6664: Patient acceptance and preferance of CT colonography compared to optical colonoscopy for colon cancer screening

4034

Background: Colorectal cancer screening must be repeated on a regular basis. Understanding patient perceptions and willingness to be rescreened will help to determine future compliance rates. The purpose of this study was to compare National CT Colonography Trial (NCTCT) screening participant experiences with CT colonography (CTC) and optical colonoscopy (OC), willingness to return for each procedure, and procedure preference. Methods: NCTCT participants underwent a single bowel preparation (BP). Participants were scheduled to receive CTC, followed by sedation and OC. Participants were asked to complete a questionnaire two weeks post-exam on physical discomfort and embarrassment during BP, CTC and OC and willingness to repeat CTC and OC (with or without BP) at different time intervals. McNemar's Test and logistic regression were used for statistical analysis. Results: 2310 of 2600 patients (89%) responded (1224 women, 1086 men). Mean age was 58.39 years (range 50–86). The participant population was 85% Caucasian, 11% African American and 4% other. Severe discomfort was reported by 7.1% participants with BP, 6.3% with CTC, and 2.2% with OC. Severe embarrassment was reported by 1.6% participants with BP, 1.3% with CTC, and 0.7% with OC. Forty-six percent of participants preferred CTC, 27.4% reported no preference, and 24.9% preferred OC (p<0.001). Repeat screening with CTC is currently recommended every 5 years and with OC every 10 years. 80.5% of the participants were willing to be screened again with CTC in 5 years and 97.5 % were willing to be screened again with OC in 10 years (p<0.001). If the screening interval for CTC were extended to ten years, 93.7% of participants were willing to return for screening (p<0.001). If BP were unnecessary, 91.0% were willing to be rescreened with CTC in 5 years and 97.5% were willing to be rescreened with OC in 10 years (p<0.001). Conclusions: NCTCT participants preferred CTC to OC, but their willingness to undergo repeat CTC was limited by the shorter interval between screenings currently recommended for CTC as opposed to OC. Improvements in technology that would eliminate the need for bowel preparation or extend the recommended screening interval would likely improve adherence to recommended repeat screening.

[Table: see text]

Is Speed of Onset of Anti-anxiety Efficacy with Pregabalin Influenced by Starting Dose?

Objective:

There appears to be no dose-response effect for pregabalin at doses of 300-600 mg, and a modest dose-response effect in the range of 150-300 mg. The goal of the current investigation was to determine the effect of the starting dose on the speed of onset of anxiolytic efficacy.

Methods:

Data were analyzed from 7 trials of outpatients with DSM-IV GAD and a HAM-A total score ≥18. Starting doses of pregabalin ranged from 100 mg (N=301) or 150 mg (N=104), to 200 mg (N=167) and 300 mg (N=388). Assessment of early improvement included the HAM-A total score and CGI-Severity and Improvement scores.

Results:

The mean Week 1 HAM-A change score was similar for a starting dose of 200 mg/d with no titration (-8.24) when compared to patients who started on 200 mg/d and then titrated up to 400 mg/d on Day 4 (-8.64). The mean Week 1 HAM-A change score was somewhat higher for patients started on 300 mg/d, and then titrated to 450 mg/d on Day 4/5 (-8.84) when compared to patients started on a lower (100/150 mg/d) dose and titrated on Day 5 to 400/450 mg/d (-7.32). Starting on a dose of 300 mg/d with no titration resulted in an intermediate Week 1 change score (-7.87). The interaction of starting dose and titration schedule with baseline anxiety severity will be summarized in detail.

Conclusion:

The initial dose of pregabalin appears to have only a weak effect on the speed of onset of anxiolytic improvement.

Absorption and emission maxima for common fluorophores

This unit lists absorption and emission maximum wavelengths for common fluorophores used in cell biology. This information can be used in designing experiments and selecting appropriate filters for use with the fluorophores.

Quantitative imaging of protein-protein interactions by multiphoton fluorescence lifetime imaging microscopy using a streak camera

Fluorescence lifetime imaging microscopy (FLIM) using multiphoton excitation techniques is now finding an important place in quantitative imaging of protein-protein interactions and intracellular physiology. Recent developments in multiphoton FLIM methods are reviewed and a novel multiphoton FLIM system using a streak camera is described. An example of a typical application of the system is provided in which the fluorescence resonance energy transfer between a donor-acceptor pair of fluorescent proteins within a cellular specimen is measured.

Telementoring and teleproctoring

Telemedicine has previously been defined as "live two-way interactive video communication between a physician and a patient and/or another physician, where all participants are able to see and hear one another much like a face to face encounter." This concept has gained recent notoriety because of the great advances in telecommunications and the potential future increased cost-effectiveness associated with its utilization. We have developed a telementoring deployment protocol that can be effectively used to introduce a student to telementoring processes. The strict protocol uses military commands to facilitate smooth information transfer. The use of a concept called tactical information deployment provides the surgeon with rapid access to reference information in the operating suite. Multimedia interactive CD-ROMs, with digitized movie clips, illustrations, sound bits, and the latest academic review of the literature arm the surgeon with a database that establishes an unprecedented clinical adaptive capability (CAC). The availability of this information is invaluable to surgeons in their initial advanced laparoscopic procedural efforts. Telementoring simulator opportunities are included to acclimate the participant to the process. If the process seems comprehensive, it is meant to be. This is a high-risk situation, and a patient's welfare is on the line. If this concept is to reach its maximal healthcare delivery potential, responsible and academically credible training programs should be established with directional guidelines.

An overview of videostreaming on the Internet and its application to surgical education

The Information Age has endowed mankind with a wealth of new technologies. Applications of these technologies are being developed to facilitate content exchange between individuals and institutions. Internet streaming is an exciting new technology that allows multimedia content to be stored and sent over the Internet, and medical educators are challenged to harness the potential of streaming for educational enhancement. This article helps to define streaming, examining its potential for surgical education.

Measurement of mitochondrial pH in situ

In this article, we describe the advantages and disadvantages of procedures for monitoring mitochondrial pH in situ using optical microscopic techniques. The first method employs the combination of the fluorescent pH-sensitive indicator carboxy-SNARF and laser scanning confocal microscopy. Manipulation of the loading and post-loading conditions enables relatively specific accumulation of carboxy-SNARF into mitochondria. With the use of a mitochondrial-specific marker, mitochondrial pH can be accurately monitored. More recently, mitochondrial-targeted, pH-sensitive probes have been used to monitor mitochondrial pH. In particular, mitochondrial targeting of the yellow fluorescent protein (YFP) mutant of green fluorescent protein (GFP) combines the advantages of specific mitochondrial localization, high-fluorophore quantum yield, and extinction coefficient with an appropriate pKa for measuring mitochondrial pH. The use of dual-excitation ratiometry with mitochondrially targeted YFP increases the dynamic range of mitochondrial pH measurements and corrects for differences in the amount of expression of mitochondrially targeted YFP at the level of individual mitochondria.

Patterns of resource allocation are reliable among younger and older readers

Younger and older adults read short expository passages across 2 times of measurement for subsequent comprehension or recall. Regression analysis was used to decompose word-by-word reading times into resources allocated to word- and textbase-level processes. Readers were more sensitive to these demands when reading for recall than when reading for comprehension. Patterns of resource allocation showed good test-retest reliabilities and were predictive of memory performance. Within age group, resource allocation parameters were not systematically correlated with other individual-difference measures, suggesting that strategies of on-line resource allocation may be a unique source of individual differences in determining comprehension of and memory for text. Age differences in allocation patterns appeared to reflect general slowing among the older adults. Because older adults showed equivalent memory performance to that of younger readers, the reading time data may represent the on-line resource allocation needed for comparable outcomes among older and younger readers.

Right ventricular response to high-dose almitrine infusion in patients with severe hypoxemia related to acute respiratory distress syndrome

OBJECTIVE

To evaluate the effects of high-dose almitrine infusion on gas exchange and right ventricular function in patients with severe hypoxemia related to acute respiratory distress syndrome (ARDS).

DESIGN

Prospective study.

SETTING

Medicosurgical intensive care department (ten beds).

PATIENTS

Nine patients with ARDS and severe hypoxemia (PaO2/FIO2 ratio, <150 torr [20 kPa]).

INTERVENTION

High-dose almitrine infusion (16 microg/kg/min for 30 mins).

MEASUREMENTS AND MAIN RESULTS

Gas exchange and hemodynamic parameters were recorded before and after almitrine infusion. Right ventricular function was evaluated by using a fast response thermistor pulmonary artery catheter that allowed measurement of right ventricular ejection fraction and calculation of right ventricular end-diastolic and end-systolic volumes. Almitrine did not significantly alter arterial oxygenation and intrapulmonary shunt. Almitrine increased mean pulmonary arterial pressure (MPAP) from 31 +/- 4 to 33 +/- 4 mm Hg (p < .05), pulmonary vascular resistance index from 353 +/- 63 to 397 +/- 100 dyne x sec/ cm5 x m2 (p < .05), and right ventricular end-systolic volume index from 71 +/- 22 to 77 +/- 21 mL/m2 (p < .05); almitrine decreased right ventricular ejection fraction from 36% +/- 7% to 34% +/- 8% (p < .05). Stroke volume index and cardiac index did not change. The almitrine-induced changes in right ventricular ejection fraction were closely correlated with the baseline MPAP (r2 = .71, p < .01).

CONCLUSION

In patients with severe hypoxemia related to ARDS, high-dose almitrine infusion did not improve arterial oxygenation and impaired the loading conditions of the right ventricle. The decrease in right ventricular ejection fraction induced by almitrine was correlated with the baseline MPAP. Thus, high-dose almitrine infusion may be harmful in ARDS patients with severe hypoxemia and pulmonary hypertension.

Confocal microscopy of the mitochondrial permeability transition in necrotic and apoptotic cell death

Opening of a high-conductance pore in the mitochondrial inner membrane induces onset of the mitochondrial permeability transition (mPT). Cyclosporin A and trifluoperazine inhibit this pore and block necrotic cell death in oxidative stress, Ca2+ ionophore toxicity, Reye-related drug toxicity, pH-dependent ischaemia/reperfusion injury and other models of cell injury. Confocal fluorescence microscopy directly visualizes the increased mitochondrial membrane permeability of the mPT from the movement of calcein from the cytosol into the matrix space. Pyridine nucleotide oxidation, increased mitochondrial Ca2+ and mitochondrial generation of reactive oxygen species (ROS) all contribute to the onset of the mPT in situ. Confocal microscopy also shows directly that the mPT is a critical link in apoptotic signalling by tumour necrosis factor-alpha at a point downstream of caspase 8 and upstream of caspase 3. Cyclosporin A blocks this mPT, preventing release of pro-apoptotic cytochrome c from mitochondria and subsequent apoptotic cell killing. Progression to necrosis or apoptosis after the mPT depends on the availability of ATP, which blocks necrosis but promotes the apoptotic programme. Given the pathophysiological importance of the mPT, development of agents to modulate the mPT represents an important new goal for pharmaceutical drug discovery.

Human papillomavirus type 16 E6 and HPV-16 E6/E7 sensitize human keratinocytes to apoptosis induced by chemotherapeutic agents: roles of p53 and caspase activation

We and others have previously reported that human papillomavirus (HPV)-16 E6 protein expression sensitizes certain cell types to apoptosis. To confirm that this sensitization occurred in HPV's natural host cells, and to explore the mechanism(s) of sensitization, we infected human keratinocytes (HKCs) with retroviruses containing HPV-6 E6, HPV-16 E6, HPV-16 E7, or HPV-16 E6/E7. Apoptosis was monitored by DNA fragmentation gel analysis and direct observation of nuclei in cells stained with DAPI. Exposure of HKCs to etoposide, cisplatin, mitomycin C (MMC), atractyloside, and sodium butyrate, resulted in a time and dose-dependent induction of apoptosis. Expression of HPV-16 E6 and HPV-16 E6/E7, but not HPV-6 E6 or HPV-16 E7, enhanced the sensitivity of HKCs to cisplatin-, etoposide- and MMC-, but not atractyloside- or sodium butyrate-induced apoptosis. Expression of both HPV-16 E6 and HPV-16 E6/E7 decreased, but did not abolish, p53 protein levels relative to normal HKCs, and resulted in cytoplasmic localization of wt p53. P53 induction occurred in HPV-16 E6 and HPV-16 E6/E7 expressing cells after exposure to cisplatin or MMC, though never to levels found in normal untreated HKCs. P21 levels were decreased in HPV-16 E6 and HPV-16 E6/E7 expressing HKCs, and no induction of p21 was seen in these cells following exposure to cisplatin or MMC. Caspase-3 activity was found to be elevated in HPV-16 E6-expressing HKCs following exposure to cisplatin and MMC as documented by fluorometric and Western Blot analysis. Expression of wt CrmA or treatment of HPV-16 E6 expressing HKCs with the caspase-3 inhibitor DEVD.fmk prevented HPV-16 E6-induced sensitization in HKCs. These results suggest that HPV-16 E6 and HPV-16 E6/E7 expression sensitizes HKCs to apoptosis caused by cisplatin, etoposide and MMC, but not atractyloside or sodium butyrate. The data also suggest that wt p53 and caspase-3 activity are required for HPV-16 E6 and HPV-16 E6/E7-induced sensitization of HKCs to DNA damaging agents.

Feasibility of mitral flow assessment by echo-contrast ultrasound, part I: determination of the properties of echo-contrast agents

Data on the ultrasonic properties of commercially available contrast agents are limited by being instrument-dependent, especially with regard to their backscattering properties. The present work describes methods of measurements that provide instrument-independent estimations of a contrast agent's attenuation coefficient and integrated backscatter index and provide them as functions of its concentration. The two studied commercially available contrast agents were Albunex and Levovist SHU 508-A, both representative of agents in common use for echocardiography. The attenuation coefficients and integrated backscatter indices of both agents were found to be a linear function of their concentrations. Proportionality coefficients +/- their standard deviations are provided. Actually, square root values of the averaged backscatter indices normalized with respect to the rms of the reference signal were determined. The coefficients of proportionality were found to be: C(A) = 3.11+/-0.1813 dB/mm; C(L) = 0.07+/-0.005 dB/mm for attenuation coefficients of the Albunex and Levovist contrast agents, respectively, and the corresponding values for backscattering were: D(A) = 0.07+/-0.0054; D(L) = 0.02+/-0.0012. Being apparatus-independent, the findings of the study are important prerequisites for the use of these echo-contrast agents as an indicator in research for a quantitative assessment of blood flow.

Feasibility of mitral flow assessment by echo-contrast ultrasound, part II: experimental study on a mechanical model of the left heart

The feasibility of assessing mitral flow by means of ultrasonic monitoring of backscattered power from an echo-contrast agent in the left atrium and left ventricle was studied. A mechanical model of the left heart was built in which two thin rubber balloons connected to each other in a feedback loop via two artificial heart valves mimicked the left atrium and left ventricle. The model was driven by compressed air. Its input and output flows were measured as the functions of a pacing rate, driving pressure and artificially introduced mitral regurgitation. These were compared with the corresponding data derived from the ultrasonic measurements that are based on the correlation between echo-contrast agent concentration in the volume of interest and the flow through it. Algorithms for quantitative estimations of forward stroke volume (cardiac output) and mitral regurgitation are given. This study shows, for the first time, both analytically and experimentally, that the pulsating modulation of contrast agent concentration vs. time curves in the ventricle and atrium volumes is closely related to the pulsating nature of the flow in the system. It also shows that the amplitude of the atrium concentration modulation is directly proportional to the maximum value of the incoming (to atrium) flow.

Multicenter prospective study of ventilator-associated pneumonia during acute respiratory distress syndrome. Incidence, prognosis, and risk factors. ARDS Study Group

We investigated the incidence, risk factors for, and outcome of ventilator-associated pneumonia (VAP) in patients with acute respiratory distress syndrome (ARDS). We compared 134 patients with ARDS with 744 patients without ARDS on mechanical ventilation. Fiberoptic bronchoscopic examination and quantitative bacterial cultures (protected brush or catheter sampling [threshold: 10(3) cfu/ml], or bronchoalveolar lavage [threshold: 10(4) cfu/ml]) were used to diagnose pneumonia. VAP occurred in 49 patients (36.5%). The incidence of pneumonia was 23% (173 of 744 patients) among patients without ARDS (p < 0.002). Nonfermenting gram-negative rods caused significantly more pneumonia in ARDS patients. Mortality rates were identical in ARDS patients with (28 of 49 patients, 57%) and without (50 of 85 patients, 59%) pulmonary infection (p = 0.8). VAP resulted in a considerable increase in attributable time on mechanical ventilation of both the overall population of ARDS patients and of survivors. Both the use of sucralfate (adjusted odds ratio [OR]: 4. 42; 95% confidence interval [CI]: 2.01 to 9.7, p = 0.0002) and the duration of exposure to sucralfate (adjusted OR: 1.206; 95% CI: 1. 095 to 1.328, p = 0.0002) were associated with an increased risk of VAP during ARDS. VAP considerably prolongs the time on mechanical ventilation without affecting survival. Patients given sucralfate may be at greater risk of developing pulmonary infection during ARDS.

Effectiveness of a CD-ROM multimedia tutorial in transferring cognitive knowledge essential for laparoscopic skill training

BACKGROUND

Computer-assisted instruction (CAI) can benefit surgical education by improving efficiency, effectiveness, standardization, and access. This study compares knowledge gains for laparoscopic skill acquisition following a standardized tutorial delivered via CD-ROM versus live instructor.

METHODS

A standardized tutorial was written and subsequently converted to multimedia CD-ROM format by its author (JR). During a laparoscopic development course, experienced US-trained surgeons (n = 52) participated in the tutorial delivered live by the author. The CD-ROM tutorial replaced the instructor for the following groups: (1) experienced US-trained surgeons (n = 27); (2) US-trained surgical residents (n = 59); and (3) Greek surgeons (n = 63). A 51-item knowledge test was administered before and after tutorial instruction.

RESULTS

The mean increase in scores between pretest and posttest was significant (P <0.01) and of similar magnitude in each group, with nonsignificant posttest mean differences among US-trained groups.

CONCLUSIONS

The CD-ROM tutorial effectively transfers cognitive information necessary for skill development. Distance learning modes of this tutorial program may be feasible.

Mitochondrial dysfunction in the pathogenesis of necrotic and apoptotic cell death

Mitochondria are frequently the target of injury after stresses leading to necrotic and apoptotic cell death. Inhibition of oxidative phosphorylation progresses to uncoupling when opening of a high conductance permeability transition (PT) pore in the mitochondrial inner membrane abruptly increases the permeability of the mitochondrial inner membrane to solutes of molecular mass up to 1500 Da. Cyclosporin A (CsA) blocks this mitochondrial permeability transition (MPT) and prevents necrotic cell death from oxidative stress, Ca2+ ionophore toxicity, Reye-related drug toxicity, pH-dependent ischemia/reperfusion injury, and other models of cell injury. Confocal fluorescence microscopy directly visualizes onset of the MPT from the movement of green-fluorescing calcein into mitochondria and the simultaneous release from mitochondria of red-fluorescing tetramethylrhodamine methylester, a membrane potential-indicating fluorophore. In oxidative stress to hepatocytes induced by tert-butylhydroperoxide, NAD(P)H oxidation, increased mitochondrial Ca2+, and mitochondrial generation of reactive oxygen species precede and contribute to onset of the MPT. Confocal microscopy also shows directly that the MPT is a critical event in apoptosis of hepatocytes induced by tumor necrosis factor-alpha. Progression to necrotic and apoptotic cell killing depends, at least in part, on the effect the MPT has on cellular ATP levels. If ATP levels fall profoundly, necrotic killing ensues. If ATP levels are at least partially maintained, apoptosis follows the MPT. Cellular features of both apoptosis and necrosis frequently occur together after death signals and toxic stresses. A new term, necrapoptosis, describes such death processes that begin with a common stress or death signal, progress by shared pathways, but culminate in either cell lysis (necrosis) or programmed cellular resorption (apoptosis) depending on modifying factors such as ATP.

Localization of Rat Liver Group IIA Phospholipase A(2) in Secretory Pathways: Green Fluorescent Protein Approach

Rat liver group IIA phospholipase A(2) (PLA(2), Enzyme Commission Number [E.C.] 3.1.1.4) was initially isolated from mitochondria. Since then it has been thought that it resides in mitochondria and that mitochondria are its main subcellular target. We cloned the cDNA sequence of rat group IIA PLA(2) and fused its presequence (signal peptide) to enhanced green fluorescent protein (EGFP). In baby hamster kidney (BHK) cells transiently and stably expressing the fusion protein, the fluorescence does not localize in mitochondria, but rather in the secretory pathway. These results suggest that the plasma membrane, and not mitochondria, is the primary target of rat group IIA PLA(2).

Differential sensitivity of mouse neural crest cells to ethanol-induced toxicity

Neural crest cells (NCCs) have been identified as an important target population relative to ethanol-induced teratogenicity in both mouse and avian models. Additionally, whole embryo culture mouse models have shown strain-related differences in sensitivity to ethanol-induced damage following acute exposure during early NCC development. That differential sensitivity of NCCs may contribute to these strain differences has been unexplored. For this purpose, cultured NCCs from an inbred mouse strain (C57BL/6J; C57) that is more sensitive to ethanol-induced teratogenicity than an outbred strain (ICR) were compared. This study showed that the incidence of cell death was significantly higher for the C57 NCCs than those from the ICR strain at all ethanol concentrations tested, and as early as 12 hours after initial exposure to 100 mM ethanol. The lateral mobility of the membrane lipids was faster and the membrane GM1 content was lower in C57 cells than ICR cells both under control conditions and at all doses and times tested. Ethanol exposure resulted in significant increases in the membrane lipid lateral mobility, and decreases in the membrane GM1 content that occurred in a dose and time-dependent manner in the NCCs from both strains. A significant correlation was found between the GM1 content and lateral mobility of the membrane lipids, the lateral mobility of membrane lipids and cell viability, as well as the GM1 content and cell viability in the NCCs from both strains. These results suggest that different strain sensitivities to ethanol-induced teratogencity may lie, at least in part, in the interstrain differential response of the NCC population and that the vulnerability of the NCCs to ethanol-induced death may be related to their endogenous membrane GM1 content.

Measurement of intracellular calcium

To a certain extent, all cellular, physiological, and pathological phenomena that occur in cells are accompanied by ionic changes. The development of techniques allowing the measurement of such ion activities has contributed substantially to our understanding of normal and abnormal cellular function. Digital video microscopy, confocal laser scanning microscopy, and more recently multiphoton microscopy have allowed the precise spatial analysis of intracellular ion activity at the subcellular level in addition to measurement of its concentration. It is well known that Ca2+ regulates numerous physiological cellular phenomena as a second messenger as well as triggering pathological events such as cell injury and death. A number of methods have been developed to measure intracellular Ca2+. In this review, we summarize the advantages and pitfalls of a variety of Ca2+ indicators used in both optical and nonoptical techniques employed for measuring intracellular Ca2+ concentration.

Secretory group IIA phospholipase A(2) generates anti-apoptotic survival signals in kidney fibroblasts

Mammalian group IIA phospholipase A(2) (PLA(2)) is believed to play important roles in inflammation, cell injury, and tumor resistance. However, the cellular site of action has not been clearly defined as it has long been recognized that group IIA PLA(2) is both a secretory and mitochondrial protein. The purpose of this study was to determine the subcellular target of the group IIA PLA(2) and its role in apoptosis stimulated by growth factor withdrawal. Cloning of the rat liver group IIA PLA(2) demonstrated a typical secretory signal and no alternative splicing of the primary transcript. When a sequence including the signal peptide and first 8 residues in the mature enzyme or the entire PLA(2) (including the signal peptide) was fused to enhanced green fluorescent protein, the fusion protein was directed to the secretory pathway rather than mitochondria in baby hamster kidney (BHK) cells. To examine the role of group IIA PLA(2) in cell injury, wild type (wt) rat group IIA PLA(2) and a mutant group IIA PLA(2) containing a His-47 --> Gln mutation (at the catalytic center) were transfected into BHK cells and cells stably expressing these constructs were isolated. After deprivation of growth factors, both normal BHK cells and BHK cells expressing mutant PLA(2) underwent massive apoptosis, while BHK cells expressing wt PLA(2) showed considerable resistance to growth factor withdrawal-induced apoptosis. The secretory PLA(2) inhibitors 12-epi-scalaradial and aristolochic acid abrogated resistance to apoptosis in the wt PLA(2) expressing cells. These two inhibitors did not induce cell death in the presence of fetal bovine serum, suggesting that they induce cell death by blocking PLA(2) generated survival signals. This study demonstrates that group IIA PLA(2) generates anti-apoptotic survival signals in BHK cells targeting the secretory pathway, and suggests that high levels of group IIA PLA(2) accumulated at inflammatory sites may not only regulate inflammation, but also may protect cells from unnecessary death induced by pro-inflammatory agents.

Mitochondrial dysfunction in the pathogenesis of necrotic and apoptotic cell death

Mitochondria are frequently the target of injury after stresses leading to necrotic and apoptotic cell death. Inhibition of oxidative phosphorylation progresses to uncoupling when opening of a high conductance permeability transition (PT) pore in the mitochondrial inner membrane abruptly increases the permeability of the mitochondrial inner membrane to solutes of molecular mass up to 1500 Da. Cyclosporin A (CsA) blocks this mitochondrial permeability transition (MPT) and prevents necrotic cell death from oxidative stress, Ca2+ ionophore toxicity, Reye-related drug toxicity, pH-dependent ischemia/reperfusion injury, and other models of cell injury. Confocal fluorescence microscopy directly visualizes onset of the MPT from the movement of green-fluorescing calcein into mitochondria and the simultaneous release from mitochondria of red-fluorescing tetramethylrhodamine methylester, a membrane potential-indicating fluorophore. In oxidative stress to hepatocytes induced by tert-butylhydroperoxide, NAD(P)H oxidation, increased mitochondrial Ca2+, and mitochondrial generation of reactive oxygen species precede and contribute to onset of the MPT. Confocal microscopy also shows directly that the MPT is a critical event in apoptosis of hepatocytes induced by tumor necrosis factor-alpha. Progression to necrotic and apoptotic cell killing depends, at least in part, on the effect the MPT has on cellular ATP levels. If ATP levels fall profoundly, necrotic killing ensues. If ATP levels are at least partially maintained, apoptosis follows the MPT. Cellular features of both apoptosis and necrosis frequently occur together after death signals and toxic stresses. A new term, necrapoptosis, describes such death processes that begin with a common stress or death signal, progress by shared pathways, but culminate in either cell lysis (necrosis) or programmed cellular resorption (apoptosis) depending on modifying factors such as ATP.

[Underestimation of medical activity measured by daily activity scores]

OBJECTIVES

To assess the effectiveness of a scoring system (omega) for medical activity.

METHODS

In 100 consecutive patients (phase A), the omega scores were calculated by the physician in charge and controlled by an independent physician. In 100 additional patients, the omega scores were controlled again while using corrective measures (phase B).

RESULTS

Phase A: at least one item was forgotten in 54% of the stays. The amount of medical activity lost (MAL) was 14 +/- 13%. Phase B: there was no significant reduction in the number of stays with forgotten items (45%, p = 0.41 vs phase A) and the MAL was 17 +/- 16% (p = 0.19 vs 6 +/- 10 days, p = 0.002) and high omega II score (items recorded every time they are performed) (0.8 +/- 1.3 vs 0.4 +/- 0.7, p = 0.01) were associated with forgetting items. The MAL was negatively correlated with the length of stay (r = -0.69, p < 0.001) and omega score (r = -0.40, p = 0.001).

CONCLUSION

In routine practice, scoring systems may underestimate medical activity.

Novel mutant green fluorescent protein protease substrates reveal the activation of specific caspases during apoptosis

BACKGROUND

The caspase-mediated proteolysis of many cellular proteins is a critical event during programmed cell death or apoptosis. It is important to determine which caspases are activated in mammalian cells, and where and when activation occurs, upon receipt of specific death stimuli. Such information would be useful in the design of strategies to regulate the activation of caspases during apoptosis.

RESULTS

We developed two novel fluorescent substrates that were specifically cleaved by caspase-1 or caspase-3. For in vitro studies, four-amino-acid recognition sequences, YVAD for caspase-1 and DEVD for caspase-3, were introduced between blue fluorescent protein (BFP) and green fluorescent protein (GFP), expressed in bacteria and purified. For in vivo studies, YVAD and DEVD were introduced between cyan fluorescent protein and yellow fluorescent protein, and expression was monitored in live mammalian cells. The proximity between fluorophores was determined using fluorescence resonance energy transfer. Purified substrates were cleaved following exposure to purified caspase-1 and caspase-3. In Cos-7 cells, caspase-1 and caspase-3 substrates were cleaved upon induction of apoptosis with staurosporine, a protein-kinase inhibitor, whereas caspase-3 but not caspase-1 substrate was cleaved upon treatment of cells with the DNA-damaging agent mitomycin c.

CONCLUSIONS

These substrates allow the spatial activation of specific members of the caspase family to be deciphered during the initiation and execution phase of programmed cell death, and allow activation of specific caspases to be monitored both in vivo and in vitro. This technology is also likely to be useful for high-throughput screening of reagents that modulate caspase activity.

Generation of enhancer trap lines in Arabidopsis and characterization of expression patterns in the inflorescence

Eleven thousand, three hundred and seventy enhancer/promoter trap lines in Arabidopsis were generated via T-DNA transformation utilizing the binary vector pD991 that contains a minimal promoter fused to the uidA reporter gene. Overall 31% of the lines generated exhibit a staining pattern in the inflorescence. Flanking DNA has been cloned from 15 lines exhibiting inflorescence staining patterns by either thermal asymmetric interlaced PCR (TAIL-PCR), inverse PCR (IPCR), or partial library construction. Seeds from these lines are available from the ABRC and NASC Arabidopsis stock centers and DNA pools are available from the ABRC.

The mitochondrial permeability transition mediates both necrotic and apoptotic death of hepatocytes exposed to Br-A23187

A23187 and related Ca2+ ionophores are widely used to study Ca2+-dependent cell injury. Here, using laser scanning confocal microscopy and parameter-indicating fluorophores, we investigated the role of the mitochondrial permeability transition (MPT) in Br-A23187 toxicity to cultured rat hepatocytes. After 10 microM Br-A23187, over 60% of hepatocytes lost viability within 1 h. This necrotic cell killing was preceded by increased mitochondrial free Ca2+, mitochondrial depolarization, and onset of the MPT. Cyclosporin A (CsA), a blocker of the permeability transition pore, prevented the MPT and cell killing but had no effect on increased mitochondrial free Ca2+ and depolarization after Br-A23187. To determine whether Br-A23187-induced cell killing was linked to loss of cellular ATP supply, hepatocytes were incubated with fructose and oligomycin, a source of glycolytic ATP and an inhibitor of the uncoupler-stimulated mitochondrial ATPase, respectively. Fructose plus oligomycin prevented cell killing after Br-A23187 but not the MPT. When fructose plus oligomycin prevented necrotic cell killing, apoptosis developed after 10 h. When cells were treated additionally with CsA, these apoptotic changes were prevented. In conclusion, the MPT mediates Br-A23187 cytotoxicity. Acutely, the MPT causes mitochondrial uncoupling and profound ATP depletion, which leads to necrotic cell death. However, when glycolytic ATP generation is available, the MPT induces apoptosis. CsA blocks the MPT and prevents both necrotic and apoptotic cell killing after Br-A23187.