SAM Group Research Articles

Biomechanical comparisons of plate placement for medial tibial plateau fractures (Schatzker type IV): A biomechanical study using porcine tibias

IntroductionBiomechanical studies on medial tibial plateau fractures (MTPFs) (Schatzker classification type IV) are currently few, while studies using locking plates (LPs) placed on medial proximal tibias are unavailable. Hence, we compared the biomechanical properties of plate osteosynthesis at the medial and anteromedial placements using large- and small-fragment LPs in porcine bones. Materials and MethodsMTPFs were internally fixed using LPs on 40 porcine tibias. Specimens were equally divided into four groups: medial placement using a large-fragment LP (LPs for the medial (LM) group), anteromedial placement using a large-fragment LP (LAM group), medial placement using a small-fragment LP (SM group), and anteromedial placement using a small-fragment LP (SAM group). The translation patterns of the constructs in each group were examined by cycling loading test (displacement and translation along the mechanical axis at 10–100, 100–500, 500–1000, 1000–1500, and 1500–2000 cycles). Then, articular gaps and step-off changes after 2000 cycles were compared among the four groups. ResultsOne-way analysis of variance (ANOVA) revealed no significant differences in displacement and translation during cyclic loading. One-way ANOVA followed by post hoc analysis revealed that the anterior gap was lower in LPs for the medial (LM) than in SM (P = 0.029) and SAM (P = 0.0026). The central gap was also lower in LM than in SM (P = 0.042) and SAM (P < 0.001), and it was lower in LAM than in SAM (P = 0.047). Likewise, the posterior gap was lower in LM than in LAM (P = 0.025) and SAM (P < 0.001). Furthermore, the central step-off of SAM was higher than that of LM, LAM, and SM (P < 0.001, P = 0.0014, and P = 0.0077, respectively). The posterior step-off was lower in LM than in SAM and LAM (P = 0.037 and P < 0.001), and it was also lower in SM than in SAM (P = 0.0082). ConclusionMedial LP placement for MTPFs in porcine bones resulted in significantly lower posterior step-offs after cyclic loading than anteromedial placement, and large-fragment LPs for MTPFs caused significantly lower fracture gaps in the central articular after cyclic loading than small-fragment LPs.

Comparative Effectiveness of Ampicillin/Sulbactam versus Cefazolin as Targeted Therapy for Bacteremia Caused by Beta-Lactamase-Producing Methicillin-Sensitive Staphylococcus aureus: A Single-Center Retrospective Study.

Cefazolin (CFZ) is the first-line treatment for beta-lactamase-producing methicillin-sensitive Staphylococcus aureus (BP-MSSA) infection. In 2019, Japan experienced a CFZ shortage because of foreign object inclusion in a batch. Ampicillin/sulbactam (SAM) was preferred in many cases as definitive therapy for the treatment of BP-MSSA bacteremia to preserve broad-spectrum antibiotic stock. However, there are no previous studies reporting the clinical efficacy of SAM for BP-MSSA bacteremia. We aimed to compare the clinical efficacy and adverse effects of SAM versus CFZ in patients with BP-MSSA bacteremia. In total, 41 and 30 patients treated with SAM and CFZ, respectively, were identified. The baseline characteristics were similar in both groups. No significant differences were observed in length of hospital stay and all 30-day mortality between the two groups (p = 0.270 and 0.643, respectively). Moreover, no intergroup difference in 90-day mortality was found (hazard ratio 1.02, 95% confidential interval 0.227-4.53). Adverse effects, such as liver dysfunction, were less in the CFZ group than in the SAM group (p = 0.030). Therefore, in cases of poor CFZ supply or in patients allergic to CFZ and penicillinase-stable penicillins, SAM can be an effective therapeutic option for bacteremia due to BP-MSSA with attention of adverse effects, such as liver dysfunction.

Micro/nano-net guides M2-pattern macrophage cytoskeleton distribution via Src-ROCK signalling for enhanced angiogenesis.

Implant surface topography has been proven to determine the fate of adhered macrophage polarization, which is closely related to the cytoskeletal arrangement during adhesion. Our purpose was to establish a topography that is favourable to M2 macrophage switching by regulating macrophage cytoskeleton distribution. Two micro/nano-net structures with different pore sizes were generated by alkali bathing at medium (SAM) or high (SAH) temperature based on the micro-level surface. Their surface characteristics, in vitro macrophage polarization and impact on endothelial cells were analysed. The in vivo macrophage response and osseointegration were also tested. The results showed that the micro/nano-net has high hydrophilicity and moderate roughness. In the SAH and SAM groups, macrophages exhibited an elongated cytoskeleton with tiny protrusions and had a high M2/M1 polarization ratio with enhanced angiogenic ability, and in vivo studies also showed faster angiogenesis and bone formation in these groups. SAH showed even better results than SAM. For cytoskeleton related pathway explanation, ROCK expression was upregulated and Src expression was downregulated at the early or late adhesion stage in both the SAH and SAM groups. These results indicated that the micro/nano-net structure guides elongated macrophage adhesion states via Src-ROCK signalling and switches macrophages towards the M2 phenotype, which provides a cytoskeleton-oriented topography design for an ideal immune response.

Internal and marginal discrepancies associated with stereolithography (SLA) additively manufactured zirconia crowns

Statement of problemStereolithography (SLA) additive manufacturing (AM) technologies can be selected to fabricate zirconia crowns; however, the internal and marginal discrepancies associated with these new technologies remain unclear. PurposeThe purpose of this in vitro study was to measure and compare the marginal and internal discrepancies of milled and AM zirconia crowns by using the silicone replica technique. Material and methodsAn implant custom abutment was manufactured and scanned by using a laboratory scanner (CARES Software; Institut Straumann AG). An anatomic contour crown was digitally designed, and the standard tessellation language (STLC) file was obtained. The STLC file was splinted into 2 pieces, simulating the parts of the crown that would replace the enamel (STLG1 file) and dentin (STLG2 file) structures. Three groups were determined: anatomic contour zirconia milled (CNC group), AM anatomic contour zirconia (AM group), and AM splinted zirconia (SAM group). For the CNC group, the STLC file was used to manufacture milled (CARES zirconium-dioxide crown; Institut Straumann AG) zirconia specimens. For the AM group, the STLC file was used to additively fabricate (CERAMAKER 900; 3DCeram Co) the zirconia (3DMix ZrO2 paste; 3DCeram Co) specimens. For the SAM group, the STLG2 file was selected to AM (CERAMAKER 900; 3DCeram Co) the zirconia (3DMix ZrO2 paste; 3DCeram Co) specimens. Ten specimens per group were manufactured. The silicone replica technique was used to measure the marginal and internal discrepancies. The cement gap was measured on images captured by using a digital microscope at ×100 magnification. For the internal gap, 50 measurements were made for each specimen, and for the marginal gap, 25 measurements were made for each specimen. The normality test, Shapiro-Wilk test, was conducted. The results indicated that the distributions were not normal; therefore, nonparametric Kruskal-Wallis H and pairwise Mann-Whitney U-tests were used to analyze the data. The Spearman correlation coefficient was used to determine the correlation between marginal and internal discrepancies in all 3 groups. ResultsSignificant differences were found in marginal and internal discrepancies among the groups. The CNC group had the least marginal and internal discrepancies compared with the AM and SAM groups. The SAM group had significantly lower values for marginal and internal discrepancies than the AM group. The AM group showed the highest marginal and internal discrepancies. The CNC group had a weak correlation coefficient of 0.13 (P=.046), the AM group had a moderate correlation coefficient of 0.32 (P<.001), and the SAM group had a nonsignificant correlation coefficient of 0.12 (P=.051). ConclusionsCNC and SAM groups had clinically acceptable marginal and internal discrepancies, while the AM group had a clinically unacceptable marginal and internal crown discrepancies. Furthermore, a weak correlation was encountered between the marginal and internal discrepancies measured in all groups.

Early life trauma increases threat response of peri‐weaning rats, reduction of axo‐somatic synapses formed by parvalbumin cells and perineuronal net in the basolateral nucleus of amygdala

Early life trauma is a risk factor for life-long disorders related to emotional processing, but knowledge underlying its enduring effect is incomplete. This study was motivated by the hypothesis that early life trauma increases amygdala-dependent threat responses via reduction in inhibition by parvalbumin (PV) interneurons and perineuronal nets (PNN) supporting PV cells, thus increasing excitability of the basolateral amygdala (BLA). From postnatal day (PN) 8-12, rat pups of both sexes were reared under normal bedding or under insufficient nest-building materials to induce maternal-to-infant maltreatment trauma (Scarcity-Adversity Model, SAM). At weaning age of PN23, the SAM group exhibited increased threat responses to predator odor. The SAM-induced increase in threat response was recapitulated in normally reared PN22-23 rats that were unilaterally depleted of PNN in the BLA by the enzymes, chondroitinase-ABC plus hyaluronidase at PN19-20. Light and electron microscopic analysis of the BLA revealed that anterior-to-mid levels of SAM group's BLAs exhibited decreased PNN intensity and decreased axo-somatic synapses between PV-to-principal pyramidal-like neurons and PV-to-PV. PV and PNN densities (cells/mm2 ) in the BLA of both control (CON) and SAM groups were still low at PN12 and SAM delayed the ontogenetic rise of PV intensity and PNN density. Moreover, PV cell density in the anterior-to-mid BLA correlated negatively with threat response of CON animals, but not for SAM animals. Thus, reduction of PNN-supported, PV-mediated somatic inhibition of pyramidal cells provides a mechanistic support for the enduring effect of early life maltreatment manifested as increasing innate threat response at weaning.

Study of thyroid profile in malnourished children (6 months - 5 years) admitted in the nutritional rehabilitation centre and paediatric ward NSCB Medical College Jabalpur, India

Background: Globally, PEM continues to be a major health problem in developing countries and the most important risk factor for illnesses and death especially among young children. The research was conducted to study the effect of thyroid profile in malnourished children (6 month-5 years) admitted in tertiary care center in Central India.Methods: A cross sectional hospital based observational study was carried out in tertiary care hospital NSCB MCH Jabalpur. 80 malnourished children were included in the study. The cases were categorized into moderate and severe malnutrition as per WHO classification. Detailed clinical assessment of nutritional status followed by anthropometric measurement (weight for height) was recorded in predesigned proforma. Triiodothyronine (T3), Thyroxine (T4), thyroid stimulating hormone (TSH), serum total protein and serum albumin were estimated. The parameters were compared among SAM and MAM groups using appropriate tool.Results: Mean serum protein, serum albumin, T3, T4 were significantly low in SAM group, when compared to the MAM group (p &lt;0.001). while level of TSH was not found significant among SAM and MAM groups.Conclusions: Malnutrition is associated with decrease level of thyroid hormone levels and were positively correlated with serum total protein and albumin levels. The decrease level of thyroid hormone may have a contributory role in retarded growth and development.

Surgical stress response following hip arthroplasty regarding choice of anesthesia and postoperative analgesia

Background/Aim. Significant surgical stress response consisting of hormonal, metabolic and inflammatory changes can be initiated by the hip replacement surgery. Appropriate choice of anesthesia and postoperative analgesia should provide diminution of surgical stress response and may reduce number of perioperative complications. Surgical stress response after peripheral nerve blocks has not been studied extensively in patients who underwent hip replacement. The aim of the study was to investigate whether continuous lumbar plexus block can significantly reduce surgical stress response in comparison to other types of postoperative analgesia – continuous epidural analgesia and intravenous patient controlled analgesia (PCA) with morphine. Methods. Prospective study included 60 patients, scheduled for total hip arthroplasty. The patients were randomized into 4 groups: group CNB (central nerve block - epidural), group PNB (Peripheral nerve block - lumbar plexus block), SAM (Spinal anesthesia- PCA (anesthesia) morphine) and GAM (General anesthesia + PCA with Morphine). Serum levels of cortisol, thyroid hormones (T3, T4) and thyroid stimulating hormone (TSH), insulin, glucose and C-reactive protein (CRP) were measured in all groups – preoperatively, as well as 4 h, 12 h and 24 h after surgery. Results. The study showed that average serum cortisol levels were significantly lower 4 h after the operation in the groups where methods of regional anesthesia were performed intraoperatively (SAM, CNB, PNB); (F = 19.867; p < 0.01). Groups with postoperative continuous catheter analgesia (CNB, PNB) had significantly lower serum cortisol levels 12 h after the operation (F = 8.050; p < 0.01). The highest serum insulin levels were detected 4 h postoperatively in the CNB and PNB group, while the lowest were in the GAM group (F = 5.811; p < 0.05). Twelve hours after the operation, the lowest values of insulin were measured in the SAM group (F = 5.052; p < 0.05), while 24 h postoperatively, the lowest values were found in the SAM and GAM group (F = 6.394; p < 0.05). T3, T4 and TSH levels showed slight reduction in comparison to preoperative values without statistical significance. Blood glucose levels were significantly different among the groups 4 h after surgery with the highest values recorded in the GAM group and the lowest ones in the SAM group (F = 10.084; p < 0.01). On the other hand, 12 h after the operation significant rise in blood glucose levels was detected in the SAM group (F = 7.186; p < 0.01) Levels of CRP increased remarkably 12 h and 24 h after the surgery, but without significant difference among the groups. Conclusion. Administration of postoperative analgesia using continuous lumbar plexus block following hip arthroplasty reduces significantly stress response in comparison to postoperative PCA with morphine and has comparable effects on hormone release to epidural analgesia. Spinal anesthesia provides the best diminution of surgical stress response in the early postoperative period in comparison with other types of intraoperative analgesia.

Effect of Bilateral Oophorectomy and Natural Menopause on Bone Mineral Density

The objective of this study was to assess the effect of bilateral oophorectomy on bone mineral density in comparison with natural menopause. Bone mineral density (BMD) is measured with dual energy X-ray DXA of lumber spine and femoral neck in 133 women, aged ranged (45 -70 years). Two surgical groups consist of 100 women either after or before, surgical after menopause SAM women with mean age (66.55 ± 1.11 years), menopause duration mean (15.88 ± 1.19 years) and body mass index BMI mean (32.09 ± 1.37 Kg /m2). Women who underwent surgery before menopause SBM the mean age (57.18 ± 0.84 years), (13.31 ± 0.83 years) the mean of menopause duration and (32.26 ± 0.7 Kg /m2) the mean of body mass index BMI. The natural menopause NM include 33 women mean age (56.45 ± 0.93 years) with (6.24 ± 0.81 years) duration of menopause and (33.49 ± 1.08 Kg /m2) BMI. The mean of BMD and T-score in lumber spine L1-L4 in SAM group was (0.84 ± 0.03 gr/cm2 and -2.32 ± 0.25) respectively, in the SBM group (BMD = 0.82 ± 0.01 gr/cm2 and T-score -2.46 ± 0.12) comparing to natural menopause group NM (BMD = 1.16 ± 0.03 gr /cm2 and T-score 0.31 ± 0.23). The mean of BMD measured for femoral neck in SAM (0.72± 0.03 gr /cm2 and T-score = - 1.54 ± 0.2), in SBM (BMD = 0.81 ± 0.81 gr/cm2 and T-score = - 0.86 ± 0.12), in NM (BMD = 0.93 ± 0.03 gr/cm2 and T-score = 0.3 6 ± 0.03). Bilateral oophorectomy associated with decrease in BMD, in addition age and duration of menopause are important factors affected on BMD.

Significado psicológico del concepto investigación en investigadores

&lt;p align="justify"&gt;Esta investigación se planteó como objetivo establecer el significado psicológico de la “actividad de investigar”, para un grupo de profesionales de las Ciencias Sociales. Se usó la técnica de Redes Semánticas Naturales, versión definida por Valdez (2004), que hace énfasis en el análisis del significado psicológico construido a partir de las vivencias. El instrumento fue aplicado a 46 asistentes de un evento académico en el área de Ciencias Sociales, elegidos mediante un muestreo no probabilístico intencional. Los resultados muestran un total de 220 palabras diferentes asociadas al término &lt;em&gt;investigación&lt;/em&gt; (valor J). Los dos términos de mayor peso semántico fueron &lt;em&gt;indagación&lt;/em&gt; (106) y &lt;em&gt;búsqueda&lt;/em&gt; (101), en contraste con las palabras &lt;em&gt;análisis y disciplina&lt;/em&gt;, cuyo peso semántico fue 33. A través de una prueba de independencia entre las variables sociodemográficas y el grupo SAM, se evidenció que no existe relación significativa con el género y la edad.&lt;/p&gt;

Effect of space allowance during transport and fasting or non-fasting during lairage on welfare indicators in Merino lambs

A total of 72 male lambs of Merina breed were sampled in a 3×2 factorial design, testing three different space allowances treatment (SA) during transport [0.16 m2/animal (SAL; n=24); 0.20 m2/animal (SAM; n=24) and 0.30 m2/animal (SAH; n=24)] and two lairage treatments (TL) during 18 h previous slaughter [fasting (FAST; n=36) vs feeding (FEED; n=36)] on welfare physiological indicators. After transport, glucose and lactate dehydrogenase (LDH) were highest in SAM group and lowest in SAH one (p&lt;0.05). SAL showed intermediate values for both parameters. SA did not affect the rest of the blood parameters studied. TL-FAST treatment decreased glucose values (p&lt;0.001) while increased LDH (p&lt;0.001). Fasting caused an increase (p&lt;0.05) of Red Blood Cell Count values in SAM group. Feed deprivation did not affect cortisol or adrenaline values. Noradrenaline value was higher (p&lt;0.001) in TL-FAST groups than in TL-FEED. In conclusion, under the conditions of this study, a range of space allowance during transport between 0.16 and 0.30 m2/lamb could be recommended without showing major changes on welfare physiological indicators; and feeding could be more appropriate than fasting during lairage.

Does stakeholder engagement promote sustainable innovation orientation?

PurposeThe purpose of this paper is to focus on the contribution of stakeholder engagement to firms' innovation orientation within the context of sustainable development. It investigates whether engagement with different stakeholders promotes sustainable innovation.Design/methodology/approachThe empirical analysis is based on an international sample of 656 large companies, drawn from the annual assessment for the Dow Jones Sustainability Indexes. A logistic regression analysis was performed in order to test the hypothesized relationships between stakeholder interaction, knowledge management and sustainable innovation orientation.FindingsEmpirical results showed that knowledge sourced from engagement with internal and external stakeholders contributes to a firm's sustainable innovation orientation, but that this knowledge has to be managed by the firm internally in order to be converted into new ideas for innovation.Research limitations/implicationsSince the present study represents one of the first attempts to characterize stakeholder‐driven innovation in a quantitative way, there are some limitations related to the used database that should be addressed in future research.Practical implicationsThe results show the importance for companies of connecting the business functions of stakeholder engagement and innovation, and find flexible mechanisms to combine access and transformation of relevant stakeholder information.Originality/valueThe main contribution of the present research is to prove quantitatively that engagement with different stakeholders is a valid mechanism for promoting sustainable innovation within firms. This is done with a unique dataset, the SAM Group database. In addition, the present study will advance understanding on firm's sustainable innovation processes by framing this phenomenon as an organizational capability.

Corporate Social Responsibility: Is it Rewarded by the Corporate Bond Market? A Critical Note

The question of whether corporate social responsibility (CSR) has a positive impact on firm value has been almost exclusively analysed from the perspective of the stock market. We have therefore investigated the relationship between the valuation of Euro corporate bonds and the standards of CSR of mainly European companies for the first time in this article. Generally, the debt market exhibits a considerable weight for corporate finance, for which reason creditors should basically play a significant role in the transmission of CSR into the valuation of financial instruments. Given that socially responsible firms are often regarded as economically more successful and less risky, they should have lower risk premia. The results of the empirical analysis, however, reveal that based on an extensive data panel the risk premium for socially responsible firms – according to the classification by SAM Group – was ceterius paribus higher than for non-socially responsible companies. However, only one case of the models investigated was weakly significant. Thus, largely the relationship has to be classified as marginal; so CSR has apparently not yet been incorporated into the pricing of corporate bonds.

The SUS test: A method for the assessment of text-to-speech synthesis intelligibility using Semantically Unpredictable Sentences

This paper describes the experimental set-up used by the SAM (ESPRIT-BRA Project no. 2589: Multilingual Speech Input/Output: Assessment, Methodology and Standardisation) group for evaluating the intelligibility of text-to-speech systems at sentence level. The SUS test measures overall intelligibility of Semantically Unpredictable Sentences which can be automatically generated using five basic syntactic structures and a number of lexicons containing the most frequently occurring mini-syllabic words in each language. The sentence material has the advantage of not being fixed, as words can be extracted from the lexicons randomly to form a new set of sentences each time the test is run. Various text-to-speech systems in a number of languages have been evaluated using this test. Results have demonstrated that the SUS test is effective and that it allows for reliable comparison across synthesisers provided guidelines are followed carefully regarding the definition of the test material and actual running of the test. These recommendations are the result of experience gained during the SAM project and beyond. They are presented here so as to provide users with a standardized evaluation method which is flexible and easy to use and is applicable to a number of different languages.

Rat lung lavage surfactant enhances bacterial phagocytosis and intracellular killing by alveolar macrophages.

We have tested the effect of a preparation of rat lung lavage surfactant (SAM) on phagocytosis and intracellular killing of Staphylococcus aureus by rat alveolar macrophages (AMs). The SAM was isolated and purified by density gradient centrifugation. It was highly enriched in disaturated phosphatidylcholine, and invariably lowered the surface tension of a clean saline solution to less than 10 dynes/cm at 37 degrees C. We used a radiometric assay to measure phagocytosis as uptake by AMs of 14C phenylalanine labelled staphylococci, and intracellular killing as incorporation of 3H thymidine by viable staphylococci from the lysed AMs. When staphylococci were incubated with 100 to 300 micrograms of SAM, both phagocytosis and intracellular killing efficiency were enhanced. The mean numbers of intracellular staphylococci/AM were 24.3 +/- 3.8 and 18.3 +/- 3.0 in the SAM and control groups, respectively (p less than 0.001). The mean intracellular killing efficiency was 59.6 +/- 6.76% and 39.7 +/- 7.17% in the SAM and control groups, respectively (p less than 0.001). Previous studies have shown that unpurified rat lung lavage fluid enhances intracellular killing of staphylococci by AMs. Our results suggest that SAM may be the active principle in lung lavage fluid that enhances intracellular killing. In addition, in our test system, SAM enhanced staphylococcal phagocytosis by AMs.

PULMONARY AND CARDIOVASCULAR EFFECTS OF A TOTALLY SYNTHETIC, PROTEINFREE SURFACTANT IN PRETERM LAMBS

Tracheal instillation of surface active material improves lung expansion and survival. However, totally synthetic surface active materials have not been as effective as preparations derived from animal sources. We tested the effectiveness of a synthetic surfactant (DPPC, hexadecanol and tyloxapol) (EXO) in preterm lambs 131-133d gestation (term = 150d) delivered by C-section, paralyzed and mechanically-ventilated for 11 hr. 15 lambs received 5 ml/kg of EXO (75 mg lipid/kg) by tracheal instillation at delivery; 5 received 5 ml/kg of a surface active material prepared from adult sheep alveolar washes (SAM) (50 mg lipid/kg); 10 received nothing (Controls). PIP and FIO2 were adjusted to normalize PaCO2 and PaO2. The EXO group survived longer (12/15 alive at 11 hr) than the control animals (3/10 at 11 hr)(p<.05). In addition FRC, AaDO2, and PaO2 were higher and PaCO2 was lower in the EXO lambs versus the controls. There were no significant differences between the EXO and control animals in dynamic compliance, PIP, aortic or pulmonary blood pressure, cardiac output or amount of shunt through the ductus arteriosus. Although mean values for FRC, AaDO2 and PaO2 were higher in SAM-treated than in EXO-treated lambs, these differences never reached statistical significance (p>.08). Other measurements were similar in the EXO and SAM groups. EXO, a totally synthetic surfactant, produces significant improvement in survival and respiratory status in preterm lambs.

Systolic anterior motion of the mitral valve with and without asymmetric septal hypertrophy. Role of left ventricular posterior wall motion.

Abnormal systolic anterior (SAM) motion of the mitral valve without asymmetric hypertrophy of the interventricular septum was observed in 16 patients (group 1). 5 of the 16 patients had no other evidence of heart disease and the remaining 11 had a variety of cardiac disorders. Left ventricular dimensions, septal and posterior wall thickness, left ventricular ejection fraction, the mean velocity of circumferential fiber shortening, and the mean velocity of the posterior wall and septal contraction was measured by echocardiography in all patients in group 1. These measurements were compared with similar measurements in 14 patients with idiopathic hypertrophic subaortic stenosis (group 2) and in 11 normal subjects (group 3) to evaluate the role of the left ventricular contractility with particular reference to the left ventricular posterior wall motion in production of SAM. All patients with SAM (groups 1 and 2) showed significantly higher indexes of left ventricular contractility, particularly posterior wall velocity, and normalized mean posterior wall velocity, when compared to the normal subjects. The significantly higher posterior wall and the normalized mean posterior wall velocities in all patients with SAM suggest that the exaggerated systolic anterior motion of the left ventricular posterior wall plays an important role in production of SAM in the presence or absence of asymmetric septal hypertrophy.