Controlling Morphology and Functions of Cardiac Organoids by Two-Dimensional Geometrical Templates

Traditionally, tissue-specific organoids are generated as 3D aggregates of stem cells embedded in Matrigel or hydrogels, and the aggregates eventually end up a spherical shape and suspended in the matrix. Lack of geometrical control of organoid formation makes these spherical organoids limited for modeling the tissues with complex shapes. To address this challenge, we developed a new method to generate 3D spatial-organized cardiac organoids from 2D micropatterned human induced pluripotent stem cell (hiPSC) colonies, instead of directly from 3D stem cell aggregates. This new approach opens the possibility to create cardiac organoids that are templated by 2D non-spherical geometries, which potentially provides us a deeper understanding of biophysical controls on developmental organogenesis. Here, we designed 2D geometrical templates with quadrilateral shapes and pentagram shapes that had same total area but different geometrical shapes. Using this templated substrate, we grew cardiac organoids from hiPSCs and collected a series of parameters to characterize morphological and functional properties of the cardiac organoids. In quadrilateral templates, we found that increasing the aspect ratio impaired cardiac tissue 3D self-assembly, but the elongated geometry improved the cardiac contractile functions. However, in pentagram templates, cardiac organoid structure and function were optimized with a specific geometry of an ideal star shape. This study will shed a light on "organogenesis-by-design" by increasing the intricacy of starting templates from external geometrical cues to improve the organoid morphogenesis and functionality.

Integrating nonlinear analysis and machine learning for human induced pluripotent stem cell-based drug cardiotoxicity testing

Utilizing recent advances in human induced pluripotent stem cell (hiPSC) technology, nonlinear analysis and machine learning we can create novel tools to evaluate drug-induced cardiotoxicity on human cardiomyocytes. With cardiovascular disease remaining the leading cause of death globally it has become imperative to create effective and modern tools to test the efficacy and toxicity of drugs to combat heart disease. The calcium transient signals recorded from hiPSC-derived cardiomyocytes (hiPSC-CMs) are highly complex and dynamic with great degrees of response characteristics to various drug treatments. However, traditional linear methods often fail to capture the subtle variation in these signals generated by hiPSC-CMs. In this work, we integrated nonlinear analysis, dimensionality reduction techniques and machine learning algorithms for better classifying the contractile signals from hiPSC-CMs in response to different drug exposure. By utilizing extracted parameters from a commercially available high-throughput testing platform, we were able to distinguish the groups with drug treatment from baseline controls, determine the drug exposure relative to IC50 values, and classify the drugs by its unique cardiac responses. By incorporating nonlinear parameters computed by phase space reconstruction, we were able to improve our machine learning algorithm's ability to predict cardiotoxic levels and drug classifications. We also visualized the effects of drug treatment and dosages with dimensionality reduction techniques, t-distributed stochastic neighbor embedding (t-SNE). We have shown that integration of nonlinear analysis and artificial intelligence has proven to be a powerful tool for analyzing cardiotoxicity and classifying toxic compounds through their mechanistic action.

Biomaterial-guided stem cell organoid engineering for modeling development and diseases

Organoids are miniature models of organs to recapitulate spatiotemporal cellular organization and tissue functionality. The production of organoids has revolutionized the field of developmental biology, providing the possibility to study and guide human development and diseases in a dish. More recently, novel biomaterial-based culture systems demonstrated the feasibility and versatility to engineer and produce the organoids in a consistent and reproducible manner. By engineering proper tissue microenvironment, functional organoids have been able to exhibit spatial-distinct tissue patterning and morphogenesis. This review focuses on enabling technologies in the field of organoid engineering, including the control of biochemical and biophysical cues via hydrogels, as well as size and geometry control via microwell and microfabrication techniques. In addition, this review discusses the enhancement of organoid systems for therapeutic applications using biofabrication and organoid-on-chip platforms, which facilitate the assembly of complex organoid systems for in vitro modeling of development and diseases. STATEMENT OF SIGNIFICANCE: Stem cell organoids have revolutionized the fields of developmental biology and tissue engineering, providing the opportunity to study human organ development and disease progression in vitro. Various works have demonstrated that organoids can be generated using a wide variety of engineering tools, materials, and systems. Specific culture microenvironment is tailored to support the formation, function, and physiology of the organ of interest. This review highlights the importance of cellular microenvironment in organoid culture, the versatility of organoid engineering techniques, and future perspectives to build better organoid systems.

Engineering spatial-organized cardiac organoids for developmental toxicity testing

Emerging technologies in stem cell engineering have produced sophisticated organoid platforms by controlling stem cell fate via biomaterial instructive cues. By micropatterning and differentiating human induced pluripotent stem cells (hiPSCs), we have engineered spatially organized cardiac organoids with contracting cardiomyocytes in the center surrounded by stromal cells distributed along the pattern perimeter. We investigated how geometric confinement directed the structural morphology and contractile functions of the cardiac organoids and tailored the pattern geometry to optimize organoid production. Using modern data-mining techniques, we found that pattern sizes significantly affected contraction functions, particularly in the parameters related to contraction duration and diastolic functions. We applied cardiac organoids generated from 600 μm diameter circles as a developmental toxicity screening assay and quantified the embryotoxic potential of nine pharmaceutical compounds. These cardiac organoids have potential use as an in vitro platform for studying organoid structure-function relationships, developmental processes, and drug-induced cardiac developmental toxicity.

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Micropattern-based geometric confinement directs cardiac organoid development

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Cardiac organoid structure-function relationships are guided by organoid size

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Cardiac organoids can be used as an in vitro embryotoxicity assessment tool

Maladaptive Contractility of 3D Human Cardiac Microtissues to Mechanical Nonuniformity

Cardiac tissues are able to adjust their contractile behavior to adapt to the local mechanical environment. Nonuniformity of the native tissue mechanical properties contributes to the development of heart dysfunctions, yet the current in vitro cardiac tissue models often fail to recapitulate the mechanical nonuniformity. To address this issue, a 3D cardiac microtissue model is developed with engineered mechanical nonuniformity, enabled by 3D-printed hybrid matrices composed of fibers with different diameters. When escalating the complexity of tissue mechanical environments, cardiac microtissues start to develop maladaptive hypercontractile phenotypes, demonstrated in both contractile motion analysis and force-power analysis. This novel hybrid system could potentially facilitate the establishment of "pathologically-inspired" cardiac microtissue models for deeper understanding of heart pathology due to nonuniformity of the tissue mechanical environment.

An inverse free electron laser acceleration-driven Compton scattering X-ray source

The generation of X-rays and γ-rays based on synchrotron radiation from free electrons, emitted in magnet arrays such as undulators, forms the basis of much of modern X-ray science. This approach has the drawback of requiring very high energy, up to the multi-GeV-scale, electron beams, to obtain the required photon energy. Due to the limit in accelerating gradients in conventional particle accelerators, reaching high energy typically demands use of instruments exceeding 100’s of meters in length. Compact, less costly, monochromatic X-ray sources based on very high field acceleration and very short period undulators, however, may enable diverse, paradigm-changing X-ray applications ranging from novel X-ray therapy techniques to active interrogation of sensitive materials, by making them accessible in energy reach, cost and size. Such compactness and enhanced energy reach may be obtained by an all-optical approach, which employs a laser-driven high gradient accelerator based on inverse free electron laser (IFEL), followed by a collision point for inverse Compton scattering (ICS), a scheme where a laser is used to provide undulator fields. We present an experimental proof-of-principle of this approach, where a TW-class CO₂ laser pulse is split in two, with half used to accelerate a high quality electron beam up to 84 MeV through the IFEL interaction, and the other half acts as an electromagnetic undulator to generate up to 13 keV X-rays via ICS. These results demonstrate the feasibility of this scheme, which can be joined with other techniques such as laser recirculation to yield very compact photon sources, with both high peak and average brilliance, and with energies extending from the keV to MeV scale. Further, use of the IFEL acceleration with the ICS interaction produces a train of high intensity X-ray pulses, thus enabling a unique tool synchronized with a laser pulse for ultra-fast strobe, pump-probe experimental scenarios.

Quantitatively characterizing drug-induced arrhythmic contractile motions of human stem cell-derived cardiomyocytes

Quantification of abnormal contractile motions of cardiac tissue has been a noteworthy challenge and significant limitation in assessing and classifying the drug-induced arrhythmias (i.e., Torsades de pointes). To overcome these challenges, researchers have taken advantage of computational image processing tools to measure contractile motion from cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs). However, the amplitude and frequency analysis of contractile motion waveforms does not produce sufficient information to objectively classify the degree of variations between two or more sets of cardiac contractile motions. In this paper, we generated contractile motion data from beating hiPSC-CMs using motion tracking software based on optical flow analysis, and then implemented a computational algorithm, phase space reconstruction (PSR), to derive parameters (embedding, regularity, and fractal dimensions) to further characterize the dynamic nature of the cardiac contractile motions. Application of drugs known to cause cardiac arrhythmia induced significant changes to these resultant dimensional parameters calculated from PSR analysis. Integrating this new computational algorithm with the existing analytical toolbox of cardiac contractile motions will allow us to expand current assessments of cardiac tissue physiology into an automated, high-throughput, and quantifiable manner which will allow more objective assessments of drug-induced proarrhythmias.

Generation of spatial-patterned early-developing cardiac organoids using human pluripotent stem cells

The creation of human induced pluripotent stem cells (hiPSCs) has provided an unprecedented opportunity to study tissue morphogenesis and organ development through 'organogenesis-in-a-dish'. Current approaches to cardiac organoid engineering rely on either direct cardiac differentiation from embryoid bodies (EBs) or generation of aligned cardiac tissues from predifferentiated cardiomyocytes from monolayer hiPSCs. To experimentally model early cardiac organogenesis in vitro, our protocol combines biomaterials-based cell patterning with stem cell organoid engineering. 3D cardiac microchambers are created from 2D hiPSC colonies; these microchambers approximate an early-development heart with distinct spatial organization and self-assembly. With proper training in photolithography microfabrication, maintenance of human pluripotent stem cells, and cardiac differentiation, a graduate student with guidance will likely be able to carry out this experimental protocol, which requires ∼3 weeks. We envisage that this in vitro model of human early heart development could serve as an embryotoxicity screening assay in drug discovery, regulation, and prescription for healthy fetal development. We anticipate that, when applied to hiPSC lines derived from patients with inherited diseases, this protocol can be used to study the disease mechanisms of cardiac malformations at an early stage of embryogenesis.

Planar-dielectric-wakefield accelerator structure using Bragg-reflector boundaries

We report experimental measurements of narrow-band, single-mode excitation, and drive beam energy modulation, in a dielectric wakefield accelerating structure with planar geometry and Bragg-reflector boundaries. A short, relativistic electron beam (∼1  ps) with moderate charge (∼100  pC) is used to drive the wakefields in the structure. The fundamental mode of the structure is reinforced by constructive interference in the alternating dielectric layers at the boundary, and is characterized by the spectral analysis of the emitted coherent Cherenkov radiation signal. Data analysis shows a narrow-band peak at 210 GHz corresponding to the fundamental mode of the structure. Simulations in both 2D and 3D provide insight into the propagating fields and reproduction of the electron beams dynamics observables and emitted radiation characteristics.

Falls in people with MS--an individual data meta-analysis from studies from Australia, Sweden, United Kingdom and the United States

Background:

Falls are common in people with multiple sclerosis (PwMS). Previous studies have generally included small samples and had varied methods.

Objectives:

The objectives of this paper are to compile fall rates across a broad range of ages and disease severity and to definitively assess the extent to which MS-associated and demographic factors influence fall rates.

Methods:

Individual data from studies in four countries that prospectively measured falls for three months were analyzed. We determined fall rates, prevalence of fallers (≥1 falls) and frequent fallers (≥2 falls), location and timing of falls, and fall-related demographic factors.

Results:

A total of 537 participants reported 1721 falls: 56% were fallers and 37% frequent fallers. Most falls occurred indoors (65%) between 6 a.m. and 6 p.m. (75%). Primary progressive MS was associated with significantly increased odds of being a faller (odds ratio (OR) 2.02; CI 1.08–3.78). Fall risk peaked at EDSS levels of 4.0 and 6.0 with significant ORs between 5.30 (2.23–12.64) and 5.10 (2.08–12.47). The fall rate was lower in women than men (relative risk (RR) 0.80; CI 0.67–0.94) and decreased with increasing age (RR 0.97 for each year, CI 0.95–0.98).

Conclusion:

PwMS are at high risk of falls and there are important associations between falls and MS-associated disability, gender and age.

Human colonic intraepithelial lymphocytes regulate the cytokines produced by lamina propria mononuclear cells

Using an in vitro autologous human system, the immunomodulatory function of colonic intraepithelial lymphocytes (IEL) on cytokine production by lamina propria mononuclear cells (LPMNC) has been investigated. In contrast to LPMNC, colonic IEL produced only low amounts of IL-10, interferon-gamma and interleukin-2. However, co-culture experiments (IEL + LPMNC) have shown that IEL can enhance the PHA-induced synthesis of IL-2 and interferon-gamma, but not IL-10 by LPMNC. Using a transwell filter culture system apparatus, this effect was shown not to require a cell-to-cell interaction. Thus, IEL in vitro may modulate the cytokine synthesis of LPMNC, through the production of soluble factors. This may prove highly relevant in the in vivo immune activation of the gastrointestinal mucosa.

Passive mechanical properties of gastrocnemius in people with multiple sclerosis

BACKGROUND

There is evidence to suggest that contractile properties of muscles in people with multiple sclerosis change as a consequence of demyelination in central nervous system. However, passive properties of muscles in people with multiple sclerosis have not been previously investigated. The purpose of this study was to characterise passive mechanical properties of gastrocnemius in people with multiple sclerosis and to compare these properties with those of gastrocnemius in neurologically normal people.

METHODS

Ten people with multiple sclerosis having signs and symptoms of weakness in the legs (Disease step 1-3) and 10 age- and sex-matched healthy people participated in the study. Ultrasound images of muscle fascicles of medial gastrocnemius as well as passive ankle torque and ankle angle data were obtained simultaneously as the ankle was rotated through its full range with the knee in a range of positions. Analysis of ultrasound images and passive ankle torque-angle relations allowed us to derive the slack lengths and maximal strains of whole muscle-tendon units, muscle fascicles and tendons. Paired-samples t-tests were used to compare these variables in the two groups.

RESULT

There was no difference between subjects with multiple sclerosis and healthy controls in the mean slack lengths and mean maximal strains of the whole muscle-tendon units or of their fascicles or tendons.

INTERPRETATIONS

These data suggests that typically, in people with multiple sclerosis who have impaired lower limbs but are still ambulatory, the passive mechanical properties of the gastrocnemius muscles are normal.

Upper limits on a stochastic background of gravitational waves

The Laser Interferometer Gravitational-Wave Observatory has performed a third science run with much improved sensitivities of all three interferometers. We present an analysis of approximately 200 hours of data acquired during this run, used to search for a stochastic background of gravitational radiation. We place upper bounds on the energy density stored as gravitational radiation for three different spectral power laws. For the flat spectrum, our limit of omega0 < 8.4 x 10(-4) in the 69-156 Hz band is approximately 10(5) times lower than the previous result in this frequency range.

Limits on gravitational-wave emission from selected pulsars using LIGO data

We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10(-24). These strain limits translate into limits on the equatorial ellipticities of the pulsars, which are smaller than 10(-5) for the four closest pulsars.

Rémifentanil-midazolam versus sufentanil-midazolam pour la sédation prolongée en réanimation

OBJECTIVE

Remifentanil has a unique metabolic pathway that holds potential benefits for long-term sedation. We compared remifentanil-midazolam to sufentanil-midazolam in 41 critically ill adults requiring mechanical ventilation.

STUDY DESIGN

Randomized double-blind trial.

PATIENTS AND METHODS

Infusion rates were titrated every 4 hours to achieve the desired Ramsay score. Five fold increases in dose requirement was considered as the development of tolerance. Drugs requirement, development of tolerance and weaning time of ventilation were compared.

RESULTS

The study was stopped after an interim analysis. The remifentanil and sufentanil groups were comparable regarding IGS II: 56+/-22 vs 64+/-26, mean+/-SD, ICU length of stay: 26 (8-45) vs 19 (11-34) days, and sedation duration: 6 (4-19) vs 6 (3-16)days, median [interquartile range, IQR]). There was a shorter weaning time in the remifentanil group as compared to sufentanil group: 22 h (12-53) vs 96 (47-142) h, median [IQR], p=0.04). The daily opioid infusion rate needed to be decreased over time only in sufentanil group, p < 0.001. Tolerance occurred in 6 (30%; CI(95), 10 to 40%) remifentanil and no sufentanil patients (P=0.02).

CONCLUSION

Sufentanil infusion needed to be reduced over time and prolonged the weaning time when compared to remifentanil.

Focal bowel wall changes detected with colour Doppler ultrasound: diagnostic value in acute non-diverticular diseases of the colon

We performed a study to determine if colour Doppler findings may help to identify the cause of wall thickening in acute non-diverticular diseases of the colon. The study group included 66 patients admitted to the emergency department with a final diagnosis of infectious colitis (n=23), inflammatory colitis (n=10), ischaemic colitis (n=23) and malignant tumours (n=10). The following ultrasound features were assessed: maximal wall thickness, wall stratification, arterial flow in the colonic wall and arteriolar resistive index. Higher values of wall thickness were observed in malignant tumour (18.2+/-6.2 mm, p<0.001). Moderately thickened wall (6.6+/-1.3 mm, p< or =0.06), preserved stratification (90% versus 46% in the remainder of the study population) and lower resistive index (0.51+/-0.10, p< or =0.05) were significantly related to inflammatory colitis. Absence of arterial flow was more frequently observed in ischaemia (43% versus 12% in the remainder of the study population). In conclusion, despite some overlap, both ultrasound and colour Doppler features are helpful in the differential diagnosis of colonic thickening related to non-diverticular colonic lesions.

Prognosis and outcome of 26 patients with systemic necrotizing vasculitis admitted to the intensive care unit

OBJECTIVES

To investigate presenting features, prognostic factors and outcomes of patients with systemic necrotizing vasculitis (SNV) admitted to the intensive care unit (ICU).

METHODS

We retrospectively reviewed the medical records of all 210 SNV patients followed in our university hospital and admitted to the ICU between 1982 and 2001, with respect to clinical features, ICU disease severity scores (APACHE II and SAPS II), the Birmingham vasculitis activity score (BVAS), the five-factors score (FFS) and outcomes.

RESULTS

Twenty-six patients (16 men, 10 women) with a mean age of 46.3+/-16.5 yr were included. The reasons for ICU admission were: active SNV, 20 (77%); infection, 3 (12%); others, 3 (12%). SNV was diagnosed in 11 (42%) patients in the ICU. The mean APACHE II and SAPS II scores were significantly higher for patients who died in the ICU (P = 0.01 and P = 0.01 respectively). After a mean follow-up of 31.4+/-29.2 months, the overall mortality rate was 39% (10 patients). Among patients admitted to the ICU with active SNV, BVAS calculated at ICU admission was significantly higher for non-survivors at the end of follow-up (26.9+/-13.0 vs 14.7+/-4.6, P = 0.02).

CONCLUSION

The main reason for admitting SNV patients to the ICU was active vasculitis, which was often the first manifestation of SNV and led to its diagnosis. ICU disease severity scores at admission were associated with mortality in the ICU but did not predict long-term outcome, unlike BVAS, which accurately predicted long-term outcome but not ICU prognosis for patients admitted to the ICU with active SNV.

Lithium inhibits cell cycle progression and induces stabilization of p53 in bovine aortic endothelial cells

Lithium affects development of various organisms and cell fate through the inhibition of glycogen synthase kinase-3 beta and induction of the Wnt/beta-catenin signaling pathway. In this study, we investigated the effects of lithium on primary bovine aortic endothelial cells (BAEC). Lithium treatment of BAEC induced beta-catenin stabilization but failed to activate the transcriptional activity of the beta-catenin/T-cell factor complex. Lithium caused a sustained G(2)/M cell cycle arrest without affecting cell viability. Reversibility of this cell cycle arrest occurred up to 3 days after treatment but was reduced thereafter. Lithium-treated BAEC exhibited a senescent-like morphology with an increase in cells positive for the senescence-associated-beta-galactosidase activity. Lithium also increased the expression of p21(Cip), a cyclin-dependent kinase inhibitor, both at the protein and RNA levels. No change in p21(Cip) mRNA stability was observed, whereas the transcriptional activity of a p21(Cip) promoter-luciferase construct containing p53 binding sites was increased after lithium treatment. Furthermore, lithium caused increased transcription of a reporter gene under the control of a promoter containing the p53 consensus binding sites both in transiently transfected BAEC and in a stably transfected fibroblast cell line. Lithium caused accumulation of p53 protein in BAEC without affecting p53 mRNA levels. Finally, up-regulation of p21(Cip) in response to lithium did not occur in mouse embryonic fibroblasts that were null for p53 alleles, confirming the dependence on a p53 pathway for this lithium effect. These findings demonstrate for the first time that lithium induces also stabilization of the tumor suppressor p53 and reveal a new mechanism that may contribute to the neuroprotective effects of lithium.

Development of a national injury prevention/safe community programme in Vietnam

The aim of this study is to describe the initiation of a national programme on injury prevention/safe community (IP/SC). Market economy, Doi Moi, was introduced in Vietnam in 1986, and since then the injury pattern has been reported to have changed. The number of traffic injury deaths has increased three-fold from 1980 to 1996 and traffic injuries more than four-fold. Injuries are now the leading cause of mortality in hospitals. There are difficulties in obtaining a comprehensive picture of the injury pattern from official statistics and, in conjunction with the work initiated by the Ministry of Health, a number of local reporting systems have already been developed. Remarkable results have been achieved within the IP/SC in a very short time, based on 20 years of experience. An organizational construction system has been built from province to local community areas. Management is based on administrative and legislative documents. IP/SC implementation is considered the duty of the whole community, local authorities and people committees, and should be incorporated into local action plans. The programme is a significant contribution towards creating a safe environment in which everybody may live and work, allowing the stability for society to develop. Implementation of the programme in schools is a special characteristic. The programme will be developed in 800 schools with a large number of pupils (25% of the population). This model for safer schools is considerably concerned and is a good experience to disseminate. The recommendations are that more pilot models of IP/SC should be conducted in other localities and that the programme should be expanded to a national scale. Furthermore, co-operation between sectors and mass organizations should be encouraged and professional skills of key SC members at all levels should be raised.

Prognosis of ischemic colitis: comparison of color doppler sonography with early clinical and laboratory findings

OBJECTIVE

The objective of this study was to compare the value of color Doppler sonography with early clinical and laboratory findings in determining the prognosis of patients with ischemic colitis.

SUBJECTS AND METHODS

We reviewed the early clinical, laboratory, and color Doppler sonographic data of 24 patients with ischemic colitis. The patients were divided into two groups on the basis of their outcome. The first group comprised the patients with transient ischemia who recovered uneventfully, and the second group included the patients who needed surgery because of symptomatic transmural colic gangrene or colic stricture. Clinical data and laboratory values were compared with color Doppler sonographic findings including colic wall thickness, presence of stratification, and arterial flow in the bowel wall.

RESULTS

At univariate analysis, increased age (p = 0.007), leukocyte count (p = 0.030), lactate dehydrogenase level (p = 0.030), blood lactate level (p = 0.041), and absence of vascular flow in the colic wall (p<0.001) were significantly related to complicated ischemic colitis. At multivariate analysis, absence of arterial flow was the only significant predictor of complicated ischemic colitis (p = 0.002), with a sensitivity of 82%, a specificity of 92%, a positive predictive value of 90%, and a negative predictive value of 86%.

CONCLUSION

Absence of arterial flow in the wall of the ischemic colon on initial color Doppler sonography is suggestive of an unfavorable outcome and is more closely associated with outcome than early clinical and laboratory findings.

Effects of progestins and relaxin on glycodelin gene expression in human endometrial cells

OBJECTIVE

Glycodelin is an endometrial protein proposed to play an important role in embryonic implantation. We examined the effects of progestins and relaxin on glycodelin transcription, synthesis, and secretion.

STUDY DESIGN

Northern blotting, metabolic labeling, and fluorography were used to assess glycodelin messenger ribonucleic acid and protein synthesis in endometrial tissue and cells. Luciferase reporter constructs transfected into endometrial adenocarcinoma cells (Ishikawa cells) were used to determine whether progestins or relaxin could activate the glycodelin gene promoter.

RESULTS

Progestins but not relaxin stimulated glycodelin secretion in primary epithelial cell cultures. A 452-base pair fragment of the glycodelin gene promoter was activated 4.3 +/- 0.7 times normal by 10-nmol/L promegestone; however, addition of relaxin to the same construct repressed progestin-stimulate promoter activation by >30%.

CONCLUSION

Glycodelin transcription, synthesis, and secretion by endometrial epithelial cells were stimulated by progestins. However, relaxin failed to stimulate production of this immunomodulatory protein and, in fact, repressed progestin-stimulated activation of the glycodelin gene promoter.

Endoscopic treatment of the carpal tunnel syndrome: review of the recent literature

The carpal tunnel syndrome is a common pathology, recognized since one and half century. Its surgical treatment, median nerve neurolysis, has only been popularized 30 years ago. Despite improvement of the surgical technique, two main problems remain unsolved: lack of grip strength and "pillar" pain, which can last several weeks after surgery. Endoscopy, in a same way as knee meniscectomy or cholecystectomy, has contributed to minimize drawbacks of conventional surgery. Ten years of experience have improved the material and the technique, the most recent series reporting very low complication rates. In experimented hands, and with correct indications, endoscopic treatment of carpal tunnel syndrome offers a clinical benefit for the patient and an economical one for the Society.

Disposable versus reusable biopsy forceps: a prospective cost evaluation

BACKGROUND

There is growing advocacy for the use of disposable medical accessories to reduce the risks of infection transmission. Their purchase costs can, however, be considered as prohibitive in an endoscopy unit operating under a cost-containment program. We therefore compared the costs of reusable and disposable biopsy forceps.

METHODS

From October 1995 to September 1997, biopsies were obtained in 7740 sessions. The evaluation of costs included purchase prices, repairs, cleaning (chemicals, equipment, technician time) and autoclaving costs in a centralized sterilization unit. For comparison, the lowest purchase price for disposable biopsy forceps was $26.90 in 1997.

RESULTS

A mean of 12 new reusable forceps were purchased every year for a total purchase price of $5460. A total of 315 biopsy sessions were performed per forceps (mean time life of 3 years per forceps, including 3 repairs). Yearly repair cost was $3308, equipment $1002, chemicals $3250, central sterilization $8333, and technician salary $4373. Total cost was $25,726 and cost per biopsy session was $6.65.

CONCLUSIONS

Total purchase and reprocessing costs for reusable biopsy forceps were 25% of those of disposable devices. The use of disposable biopsy forceps would have led to a yearly extra cost of $78,377 in the operation of our endoscopy unit.

Lymphocytic colitis: a distinct clinical entity? A clinicopathological confrontation of lymphocytic and collagenous colitis

BACKGROUND AND AIMS

It is not known whether lymphocytic colitis and collagenous colitis represent different clinical entities or constitute part of a spectrum of disease.

METHODS

Detailed clinical features and histological findings were compared in a large series of patients with confirmed lymphocytic and collagenous colitis.

RESULTS

Histological diagnosis was confirmed in 96 patients with collagenous colitis and 80 with lymphocytic colitis. Twenty eight per cent of patients with collagenous colitis and 26% of patients with lymphocytic colitis had overlapping but less pronounced histological features. Both groups were equal in terms of age, use of aspirin and non-steroidal anti-inflammatory drugs, associated autoimmune conditions, arthritis, diarrhoea, and abdominal pain. The male:female ratio was 27:73 for collagenous colitis and 45:55 for lymphocytic colitis (p=0.013). Twenty five per cent of patients with collagenous colitis compared with 14% of patients with lymphocytic colitis were active smokers; only 8.3% of patients with collagenous colitis had stopped smoking compared with 23% of patients with lymphocytic colitis (p=0.013). Drug induced disease was suspected for ticlopidine (two collagenous colitis, four lymphocytic colitis) and flutamide (four lymphocytic colitis). Mean duration of symptoms before diagnosis was two months for lymphocytic colitis and four months for collagenous colitis. Overall prognosis was generally mild; 84% of patients with lymphocytic colitis and 74% of patients with collagenous colitis reported resolution or significant improvement (p=0.033).

CONCLUSIONS

Collagenous and lymphocytic colitis are similar but not identical. Patients with lymphocytic colitis present somewhat earlier and are less likely to be active smokers. Symptoms are milder and more likely to disappear in lymphocytic colitis. Ticlopidine and flutamide should be added to the list of drugs inducing colitis.

Haemodynamic measurements (continuous cardiac output and systemic vascular resistance) in critically ill patients: transoesophageal Doppler versus continuous thermodilution

Ten critically ill patients underwent this prospective study to assess the reliability of the continuous thermodilution versus transoesophageal Doppler techniques in the determination of continuous cardiac output (CO) and systemic vascular resistance (SVR). A total of 145 pairs of CO and SVR measurements were obtained by both a pulmonary artery catheter with a heated filament and a transoesophageal Doppler apparatus (ODM II). Total CO ranged from 2.4 and 13 l.min-1; the bias of all measurements was 0.01 +/- 0.48 l.min-1, and the 95% confidence limits (mean difference +/- 2 SD) were 0.97/0.96 l.min-1. Total SVR ranged from 309 and 2643 dyn.s.cm-5; the bias of all measurements was 18 +/- 127 dyn.s.cm-5, and the 95%, confidence limits were 272/236 dyn.s.cm-5. Transoesophageal Doppler accurately measures continuous CO and SVR in critically ill patients. It should be viewed as complementary to pulmonary catheterization.

Familial adenomatous polyposis associated with multiple adrenal adenomas in a patient with a rare 3' APC mutation

Familial adenomatous polyposis (FAP) is characterised by hundreds of colorectal adenomas. Endocrine neoplasms have occasionally been reported, as have gastric polyps, which are usually hamartomatous in the fundus of the stomach and adenomatous in the antrum. A 57 year old man with colorectal, gastric, and periampullary adenomatous polyposis, in association with three bilateral adrenocortical adenomas, is presented. Mutation screening showed a 5960delA germline mutation in the adenomatous polyposis coli (APC) gene predicted to lead to a premature stop codon. This mutation was found in three of the four children of the patient. Western blot analysis of a lymphoblastoid cell line derived from the patient failed to detect any truncated APC polypeptide. This rare 3' mutation is responsible for an unusually complex and late onset phenotype of FAP.

Is early enteral nutrition in acute pancreatitis dangerous? About 20 patients fed by an endoscopically placed nasogastrojejunal tube

Bowel rest during treatment of acute pancreatitis deprives the gut of nutrients and affects its structure and function. Enteral feeding is usually performed late in the course of acute pancreatitis and therefore cannot prevent intestinal barrier dysfunction and possible bacterial translocation. To assess the effect of early enteral nutrition we performed a prospective study on 21 patients (11 males/10 females) presenting with severe acute pancreatitis (13 biliary, 6 alcoholic, and 2 miscellaneous). Severity was established by a mean Ranson score of 3.57. All but one patient could be fed through a double-lumen nasogastrojejunal tube within 60 h after admission. No significant complication of the technique was observed. We conclude that early jejunal feeding can be used safely in severe acute pancreatitis. Further comparative studies are necessary to demonstrate any superiority to total parenteral nutrition.

The "hands-off" catheter and the prevention of systemic infections associated with pulmonary artery catheter: a prospective study

The Arrow "Hands-Off" thermodilution catheter (AHO) is completely shielded during balloon testing, preparation, and insertion. To assess the value of the AHO in the prevention of systemic infections associated with pulmonary artery catheterization (SIAPAC), we conducted a randomized prospective study over an 18-mo period. The patients were randomly assigned to two groups, of which one received the thermodilution catheter routinely used in our department and the other, the AHO catheter. The diagnosis of SIAPAC was based on recovery of the same organism from the thermodilution catheter (TC) and blood samples, absence of any other infectious focus, and improvement or resolution of clinical evidence of infection after removal of the TC. A total of 166 TCs were randomized in 150 patients. The two groups (mean +/- SD) were comparable in terms of age, SAPS on admission (15.6 +/- 5.2 versus 15.2 +/- 6.2), SAPS on the day of catheter insertion (17.6 +/- 4.8 versus 17.3 +/- 5.8), duration of catheter insertion (22.8 +/- 11.3 versus 25.3 +/- 19.5 min), insertion site, hemodynamic status, duration of use of the TC (3.6 +/- 1.3 versus 3.5 +/- 1.5 d), and outcome. A total of eight cases of SIAPAC were diagnosed in the standard TC group, versus none in the AHO group (p < 0.002). No cases of SIAPAC occurred in those patients who had their TC for less than four days. This study demonstrates the value of the AHO for preventing systemic infections associated with prolonged pulmonary artery catheterization.

[Initial evaluation of thoracic injuries. Comparison of pulmonary radiography and x-ray computed tomography]

OBJECTIVES

To investigate the contribution of computed tomography scan (CTS) to the initial évaluation of chest trauma.

PATIENTS AND METHODS

We carried out a two-year prospective study in all the chest trauma patients admitted to ICU. They underwent both Chest X-ray (CXR) and CTS within 24 jours of admission. CXR and CTS images were read by achieving a consensus between two radiologists who were unaware of the results of the other investigation. Then we compared these findings with the treatment received by the patients in the ICU.

RESULTS

From July 1, 1991 through July 1, 1993, 56 patients were included (21 with conventional CTS and 35 with helicoidal CTS). CTS demonstrated a significant number of pleural (p < 0.001), parenchymatous (p < 0.001), and mediastinal (p < 0.01) lesions that escaped detection on CXR (CTS+/CXR- lesions). Thoracic drainage was done in 16 patients because of abnormalities CTS+/CXR- (p < 0.01); six patients with CTS+/CXR- pulmonary contusions received Pressure Positive Ventilation (p < 0.01); and four CTS+/CXR- lesions were treated surgically (p < 0.05).

CONCLUSION

CTS adds significantly to the evaluation of chest trauma by allowing prompt, accurate assessment of lesions. In this study, over 50% of these lesions required specific treatment during the ICU stay.

Idiopathic non-familial rectal and colonic varices requiring sigmoidorectal resection and coloanal anastomosis

A 32-year-old male patient presenting with huge varices involving the sigmoid colon and the entire rectum down to the dentate line is described. There was no familial history of gastrointestinal bleeding. No particular aetiology was identified. Marked anaemia due to recurrent bleeding required resection of the sigmoid colon and rectum. Restoration of the intestinal continuity was performed by a coloanal anastomosis. The patient did well and bleeding has not recurred. To our knowledge, no similar case of such varices requiring extensive rectal surgery to control bleeding has been described in the literature.