Flow targeted 3D steady-state free-precession coronary MR angiography: comparison of three different imaging approaches.

PURPOSE: To compare 3 different flow targeted magnetization preparation strategies for coronary MR angiography (cMRA), which allow selective visualization of the vessel lumen. MATERIAL AND METHODS: The right coronary artery of 10 healthy subjects was investigated on a 1.5 Tesla MR system (Gyroscan ACS-NT, Philips Healthcare, Best, NL). A navigator-gated and ECG-triggered 3D radial steady-state free-precession (SSFP) cMRA sequence with 3 different magnetization preparation schemes was performed referred to as projection SSFP (selective labeling of the aorta, subtraction of 2 data sets), LoReIn SSFP (double-inversion preparation, selective labeling of the aorta, 1 data set), and inflow SSFP (inversion preparation, selective labeling of the coronary artery, 1 data set). Signal-to-noise ratio (SNR) of the coronary artery and aorta, contrast-to-noise ratio (CNR) between the coronary artery and epicardial fat, vessel length and vessel sharpness were analyzed. RESULTS: All cMRA sequences were successfully obtained in all subjects. Both projection SSFP and LoReIn SSFP allowed for selective visualization of the coronary arteries with excellent background suppression. Scan time was doubled in projection SSFP because of the need for subtraction of 2 data sets. In inflow SSFP, background suppression was limited to the tissue included in the inversion volume. Projection SSFP (SNR(coro): 25.6 +/- 12.1; SNR(ao): 26.1 +/- 16.8; CNR(coro-fat): 22.0 +/- 11.7) and inflow SSFP (SNR(coro): 27.9 +/- 5.4; SNR(ao): 37.4 +/- 9.2; CNR(coro-fat): 24.9 +/- 4.8) yielded significantly increased SNR and CNR compared with LoReIn SSFP (SNR(coro): 12.3 +/- 5.4; SNR(ao): 11.8 +/- 5.8; CNR(coro-fat): 9.8 +/- 5.5; P < 0.05 for both). Longest visible vessel length was found with projection SSFP (79.5 mm +/- 18.9; P < 0.05 vs. LoReIn) whereas vessel sharpness was best in inflow SSFP (68.2% +/- 4.5%; P < 0.05 vs. LoReIn). Consistently good image quality was achieved using inflow SSFP likely because of the simple planning procedure and short scanning time. CONCLUSION: Three flow targeted cMRA approaches are presented, which provide selective visualization of the coronary vessel lumen and in addition blood flow information without the need of contrast agent administration. Inflow SSFP yielded highest SNR, CNR and vessel sharpness and may prove useful as a fast and efficient approach for assessing proximal and mid vessel coronary blood flow, whereas requiring less planning skills than projection SSFP or LoReIn SSFP.

Comparison of human and rhesus macaque T-cell responses elicited by boosting with NYVAC encoding human immunodeficiency virus type 1 clade C immunogens.

Rhesus macaques (Macaca mulatta) have played a valuable role in the development of human immunodeficiency virus (HIV) vaccine candidates prior to human clinical trials. However, changes and/or improvements in immunogen quality in the good manufacturing practice (GMP) process or changes in adjuvants, schedule, route, dose, or readouts have compromised the direct comparison of T-cell responses between species. Here we report a comparative study in which T-cell responses from humans and macaques to HIV type 1 antigens (Gag, Pol, Nef, and Env) were induced by the same vaccine batches prepared under GMP and administered according to the same schedules in the absence and presence of priming. Priming with DNA (humans and macaques) or alphavirus (macaques) and boosting with NYVAC induced robust and broad antigen-specific responses, with highly similar Env-specific gamma interferon (IFN-gamma) enzyme-linked immunospot assay responses in rhesus monkeys and human volunteers. Persistent cytokine responses of antigen-specific CD4(+) and CD8(+) T cells of the central memory as well as the effector memory phenotype, capable of simultaneously eliciting multiple cytokines (IFN-gamma, interleukin 2, and tumor necrosis factor alpha), were induced. Responses were highly similar in humans and primates, confirming earlier data indicating that priming is essential for inducing robust NYVAC-boosted IFN-gamma T-cell responses. While significant similarities were observed in Env-specific responses in both species, differences were also observed with respect to responses to other HIV antigens. Future studies with other vaccines using identical lots, immunization schedules, and readouts will establish a broader data set of species similarities and differences with which increased confidence in predicting human responses may be achieved.

Alcohol may not cause partner violence but it seems to make it worse: a cross national comparison of the relationship between alcohol and severity of partner violence.

This study assesses whether severity of physical partner aggression is associated with alcohol consumption at the time of the incident, and whether the relationship between drinking and aggression severity is the same for men and women and across different countries. National or large regional general population surveys were conducted in 13 countries as part of the GENACIS collaboration. Respondents described the most physically aggressive act done to them by a partner in the past 2 years, rated the severity of aggression on a scale of 1 to 10, and reported whether either partner had been drinking when the incident occurred. Severity ratings were significantly higher for incidents in which one or both partners had been drinking compared to incidents in which neither partner had been drinking. The relationship did not differ significantly for men and women or by country. We conclude that alcohol consumption may serve to potentiate violence when it occurs, and this pattern holds across a diverse set of cultures. Further research is needed that focuses explicitly on the nature of alcohol's contribution to intimate partner aggression. Prevention needs to address the possibility of enhanced dangers of intimate partner violence when the partners have been drinking and eliminate any systemic factors that permit alcohol to be used as an excuse. Clinical services for perpetrators and victims of partner violence need to address the role of drinking practices, including the dynamics and process of aggressive incidents that occur when one or both partners have been drinking.

mtDNA comparison of the Alpine chromosomal races and species of the Sorex araneus group: preliminary results

279 paires de bases du gène du Cytochrome b ont été séquencés pour 16 individus appartenant aux différentes formes chromosomiques de S. araneaus des Alpes occidentales, à S. coronatus et à S. granarius, laquelle a conservé un caryotype primitif. Trois clones principaux ont été identifiés: CC correspond à S. coronatus, CV caractérise la rae chromosomique Valais de S. araneaus, à l'exception des individus capturés aux Houches près de Chamonix, et CA est commun à tous les autres A. araneaus analysés. S. granarius ne montre que de très faibles différences avec le groupe CA, ce qui est en contradiction avec les données de la caryologie. Le fait que le clone CA soit caractéristique d'individus de la race Valais aux Houches, alors qu'une correspondance claire entre race chromosomique et clone de mtDNA est relevée dans les zones de contact entre la race Vaud (clone CA) et la race Valais (clone CB), suggère que les contact entre la race Vaud (clone CA et la race Valais (clone CB); suggère que les chromosomes Valais ont pénétré les populations Acrocentriques par introgression, tandis qu'au Haslital, la race Valais a progressé en repoussant la race Vaud sans qu'il y ait eu échange génétique

Comparison of the site distribution of melanoma in New Zealand and Canada

A comparison of the site distribution of cutaneous malignant melanoma in New Zealand and Canada was performed. This series deals with 41,331 incident cases registered between 1968 and 1990 and is the largest to date to evaluate the influence of age and gender on the site distribution of melanoma. Site-specific, age-standardized rates per unit surface area and relative tumour density were assessed by gender and country and differences compared with statistical techniques adapted to this context. The age-standardized rates for all sites were higher in New Zealand than in Canada, the ratio being 3.2 for men and 3.8 for women. Occurrence of melanoma was denser for chronically than intermittently exposed sites in both New Zealand and Canada. The highest incidence rate per unit area was for the ears in men which was more than 5 times the rate for the entire body in each country. For each gender, melanomas were relatively commoner on the trunk and the face in Canada, and on the lower limbs in New Zealand. The variations in the site distribution were similar in each country and consistent with the effect of differential patterns of sun exposure between genders. Our results show that the levels of risk of melanoma between phenotypically comparable populations exposed to different amount of UV radiation vary in a site-specific manner, especially for intermittently exposed sites. This suggests that both environmental conditions and lifestyle factors influence the site distribution of melanoma in these two populations.

Comparison of transhiatal laparoscopy versus blind closed-chest cervicotomy and laparotomy for esophagectomy in children.

BACKGROUND: Esophageal replacement for caustic stenosis in children poses a challenging surgical problem. Blind removal of the injured esophagus without thoracotomy through a left cervical and transhiatal approach followed by an orthotopic esophageal replacement using either the colon or the stomach is a difficult procedure and can be dangerous in children. We performed our first total laparoscopic transhiatal esophagectomy in February 2007. We aim to compare this new technique to the previously applied method of blind closed-chest esophagectomy through a cervicotomy and laparotomy. METHODS: We analyzed the surgery and follow-up of 40 children operated upon for extensive irreversible caustic burns of the esophagus. The first 20 esophageal replacements were performed following a blind dissection of the mediastinum through a cervical incision and a laparotomy for esophagectomy (Group I). The last 20 esophageal replacements were performed after laparoscopic transhiatal dissection in the mediastinum and cervicotomy in the neck for esophagectomy (Group II). All operations were performed under the supervision of the same senior surgeon. RESULTS: Average age at the time of surgery was the same in both groups. Total esophagectomy was achieved in 45.0% of cases in Group I versus in 90.0% of cases in Group II. Colon was used in 80.0% of cases in Group I and in 90.0% in Group II. The mean duration of surgery was one hour longer in the laparoscopy group. One vascular injury was reported in the blind laparotomy group. Pneumothorax was more frequent in Group II without significant consequences besides drainage. Average time of extubation was about the same in both groups (1.8days). CONCLUSION: Laparoscopic transhiatal esophagectomy for caustic burns before esophageal replacement in children is safe and effective. It could avoid vascular and bronchial mediastinal injuries as the dissection is performed under direct visual control. The routine use of laparoscopic assistance by a senior surgeon improves the safety of esophageal dissection and reduces life-threatening complications.

Acid inhibition on the first day of dosing : comparison of four proton pump inhibitors

RESUME Introduction: Les inhibiteurs de la pompe à protons sont actuellement considérés comme les médicaments de choix pour le traitement des affections peptiques comme l'ulcère gastroduodénal et l'oesophagite de reflux. La rapidité, ainsi que le degré d'inhibition de la sécrétion gastrique acide sont importants pour le contrôle optimal des symptômes ainsi que pour le traitement de ces affections. But : Le but principal de cette étude a été de comparer, chez les sujets asymptomatiques non infectés par H. pylori, par pH-métrie intragastrique de 24 heures, la rapidité et la durée de l'action antisécrétoire de doses uniques de rabéprazole 20 mg, d'oméprazole capsule 20 mg, d'oméprazole en comprimé MUPS (« Multiple Unit Pellet System ») 20 mg, de pantoprazole 40 mg et de lansoprazole 30 mg, respectivement. Matériel et méthodes : Cette étude, effectuée en double aveugle et randomisée, a été conduite de manière croisée chez 18 sujets H. pylori-négatifs. Une pH-métrie de 24 heures a été effectuée le jour de l'administration du médicament (dose unique de rabéprazole 20 mg, de lansoprazole 30mg, de pantoprazole 40 mg, d'oméprazole capsule 20 mg, d'oméprazole MUPS comprimé 20mg, ou de placebo). Résultats : Le pH intragastrique médian (3.4 vs. 2.9, 2.2, 1.9 et 1.8, respectivement; p≤ 0.03) et le temps avec un pH supérieur à 4 pendant les 24 heures suivant la prise du médicament (8.0 heures vs. 7.4, 4.9, 2.9, et 3.0, respectivement; p≤ 0.003) ont été statistiquement plus élevés avec le rabéprazole qu'avec le lansoprazole, le pantoprazole, l'oméprazole capsule, l'oméprazole comprimé MUPS, ou le placebo. Les valeurs du pH pendant les périodes diurnes et nocturnes étaient plus hautes avec le rabeprazole et le lansoprazole qu'avec le pantoprazole, l'oméprazole capsule, et l'oméprazole comprimé MUPS (p≤0.04). Conclusion : Le rabéprazole s'est montré le plus efficace de tous les inhibiteurs de pompe à protons étudiés durant le premier jour de l'administration du médicament. SUMMARY Background: Rapid and consistent acid suppression on the first day of dosing may be important in treating acid-related disorders. Aim: To compare the antisecretory activity and onset of action of single doses of rabeprazole, lansoprazole, pantoprazole, omeprazole capsule, omeprazole multiple unit pellet system (MUPS) tablet and placebo in healthy Helicobacter pylori-negative subjects. Methods: This cross-over, double-blind, randomized study was performed in 18 H. pylori-negative subjects. Twenty-four-hour intragastric pH monitoring was performed on the day of treatment (once-daily dose of rabeprazole 20 mg, lansoprazole 30 mg, pantoprazole 40 mg, omeprazole capsule 20 mg, omeprazole MUPS tablet 20 mg or placebo). Results: The intragastric pH (3.4) and time at pH > 4 during the 24 h post-dose (8.0 h) were significantly greater with rabeprazole than with lansoprazole, pantoprazole, omeprazole capsule, omeprazole MUPS tablet or placebo (P ≤ 0.04 for rabeprazole vs. the others). Daytime and night-time pH values were higher with rabeprazole and lansoprazole than with pantoprazole, omeprazole capsule and omeprazole MUPS tablet (P ≤ 0.04). Conclusion: Rabeprazole was the most potent acid inhibitor of all the proton pump inhibitors tested during the first day of dosing.

Comparison of the single-use Ambu(®) aScope? 2 vs the conventional fibrescope for tracheal intubation in patients with cervical spine immobilisation by a semirigid collar*.

Fibreoptic intubation remains a key technique for the management of difficult intubation. We randomly compared the second generation single-use Ambu(®) aScope? 2 videoscope with a standard re-usable flexible intubating fibrescope in 50 tracheal intubations in patients with a difficult airway simulated by a semirigid collar. All patients' tracheas were intubated successfully with the aScope 2 or the re-usable fibrescope. The median (IQR [range]) time to intubate was significantly longer with the aScope 2 70 (55-97 [41?-226]) s vs 50 (40-59 [27-175]) s, p = 0.0003) due to an increased time to see the carina. Quality of vision was significantly lower with the aScope 2 (excellent 24 (48%) vs 49 (98%), p = 0.0001; good 22 (44%) vs 1 (2%), p = 0.0001; poor 4 (8%) vs 0, p = 0.12) but with no difference in the subjective ease to intubate (easy score of 31 (62%) vs 38 (76%), p = 0.19; intermediate 12 (24%) vs 7 (14%), p = 0.31; difficult 7 (14%) vs 5 (5%), p = 0.76). The longer times to intubate and the poorer scores for quality of vision do not support the use of the single-use aScope 2 videoscope as an alternative to the re-usable fibrescope.

Comparison of fat suppression strategies in 3D spiral coronary magnetic resonance angiography.

PURPOSE: In the present study, the impact of the two different fat suppression techniques was investigated for free breathing 3D spiral coronary magnetic resonance angiography (MRA). As the coronary arteries are embedded in epicardial fat and are adjacent to myocardial tissue, magnetization preparation such as T(2)-preparation and fat suppression is essential for coronary discrimination. MATERIALS AND METHODS: Fat-signal suppression in three-dimensional (3D) thin- slab coronary MRA based on a spiral k-space data acquisition can either be achieved by signal pre-saturation using a spectrally selective inversion recovery pre-pulse or by spectral-spatial excitation. In the present study, the performance of the two different approaches was studied in healthy subjects. RESULTS: No significant objective or subjective difference was found between the two fat suppression approaches. CONCLUSION: Spectral pre-saturation seems preferred for coronary MRA applications due to the ease of implementation and the shorter cardiac acquisition window.

First imaging results of an intraindividual comparison of (11)C-acetate and (18)F-fluorocholine PET/CT in patients with prostate cancer at early biochemical first or second relapse after prostatectomy or radiotherapy.

PURPOSE: (18)F-Fluorocholine (FCH) and (11)C-acetate (ACE) PET are widely used for detection of recurrent prostate cancer (PC). We present the first results of a comparative, prospective PET/CT study of both tracers evaluated in the same patients presenting with recurrence and low PSA to compare the diagnostic information provided by the two tracers. METHODS: The study group comprised 23 patients studied for a rising PSA level after radical prostatectomy (RP, 7 patients, PSA ≤ 3 ng/ml), curative radiotherapy (RT, 7 patients, PSA ≤ 5 ng/ml) or RP and salvage RT (9 patients, PSA ≤ 5 ng/ml). Both FCH and ACE PET/CT scans were performed in a random sequence a median of 4 days (range 0 to 11 days) apart. FCH PET/CT was started at injection (307 ± 16 MBq) with a 10-min dynamic acquisition of the prostate bed, followed by a whole-body PET scan and late (45 min) imaging of the pelvis. ACE PET/CT was performed as a double whole-body PET scan starting 5 and 22 min after injection (994 ± 72 MBq), and a late view (45 min) of the prostate bed. PET/CT scans were blindly reviewed by two independent pairs of two experienced nuclear medicine physicians, discordant subgroup results being discussed to reach a consensus for positive, negative end equivocal results. RESULTS: PET results were concordant in 88 out of 92 local, regional and distant findings (Cohen's kappa 0.929). In particular, results were concordant in all patients concerning local status, bone metastases and distant findings. Lymph-node results were concordant in 19 patients and different in 4 patients. On a per-patient basis results were concordant in 22 of 23 patients (14 positive, 5 negative and 3 equivocal). In only one patient was ACE PET/CT positive for nodal metastases while FCH PET/CT was overall negative; interestingly, the ACE-positive and FCH-negative lymph nodes became positive in a second FCH PET/CT scan performed a few months later. CONCLUSION: Overall, ACE and FCH PET/CT showed excellent concordance, on both a per-lesion and a per-patient basis, suggesting that both tracers perform equally for recurrent prostate cancer staging.

Comparison of a multiplexed bead-based assay with an immunofluorescence and an enzyme-immuno assay for the assessment of Epstein-Barr virus serologic status.

We have compared a multiplexed bead-based assay (BBA) with an enzyme immunoassay (EIA) and immunofluorescence assay (IFA) for the assessment of the Epstein-Barr virus (EBV) serostatus. Three hundred and ninety-three sera, classified according to IFA results as seronegative (n=100), acute infection (n=100), past infection (n=100) and indeterminate (n=93), were tested by BBA and EIA. Overall, the three methods gave similar results with a relatively high (75.2%) concordance with the consensus interpretation of the serostatus. The most significant discordances were: (i) 58 samples had uninterpretable results for BBA, in majority due to the detection of non-antigen specific antibody binding by control beads. (ii) almost half the samples positive for anti-Epstein-Barr nuclear antigen (EBNA) IgG by BBA or EIA were negative by IFA. Among the latter, only a minority had a history of immunocompromise or treatment, or detectable anti-early antigen antibody. This discrepancy probably reflects a poor sensitivity of IFA for anti-EBNA IgG detection. EIA and BBA had a similar performance and had substantial practical advantages over IFA with respect to testing for EBV serostatus.

Comparison of foetal US and MRI in the characterisation of congenital lung anomalies.

OBJECTIVES: To compare the accuracy of prenatal ultrasonography (US) to magnetic resonance imaging (MRI) in the characterisation of congenital lung anomalies, and to assess their agreement with final diagnosis. To evaluate the influence of additional MRI information on therapeutic management. METHODS: 26 prenatal congenital lung anomalies detected consecutively between 2006 and 2012 were retrospectively evaluated. Lesions were initially observed at prenatal US and further investigated with MRI. Prenatal US and MRI imaging findings, and suggested diagnosis were compared with the final diagnosis, obtained from autopsies (4), pathological evaluation following surgical resection (15) and postnatal imaging studies (7). RESULTS: Postnatal diagnoses included 7 congenital pulmonary airway malformations, 8 complex lesions, 7 overinflations, 1 sequestration, 1 bronchogenic cyst, 1 blastoma and 1 bilateral lymphangioma. Suggested prenatal US and MRI diagnosis was correct in 34.6% and 46.2% of patients, respectively, mainly isolated lung lesions with typical imaging findings. Nonspecific imaging findings at US and MRI studies were observed in 38.4% of cases. In 42% of the operated anomalies, pathological dissection revealed the presence of complex anomalies. MRI changed the US diagnosis, but not the further management in 9.7% of the lesions. CONCLUSIONS: Prenatal US and MRI showed a high accuracy in the diagnosis of isolated congenital lung lesions with typical imaging findings. However, overall characterisation rates were low, because of both a high percentage of complex lesions and of lesions with nonspecific imaging findings. MRI was better than US in characterising complex lesions, but its additional information did not influence therapy decisions.

Computed tomography of the cervical spine: comparison of image quality between a standard-dose and a low-dose protocol using filtered back-projection and iterative reconstruction.

OBJECTIVE: To compare image quality of a standard-dose (SD) and a low-dose (LD) cervical spine CT protocol using filtered back-projection (FBP) and iterative reconstruction (IR). MATERIALS AND METHODS: Forty patients investigated by cervical spine CT were prospectively randomised into two groups: SD (120 kVp, 275 mAs) and LD (120 kVp, 150 mAs), both applying automatic tube current modulation. Data were reconstructed using both FBP and sinogram-affirmed IR. Image noise, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios were measured. Two radiologists independently and blindly assessed the following anatomical structures at C3-C4 and C6-C7 levels, using a four-point scale: intervertebral disc, content of neural foramina and dural sac, ligaments, soft tissues and vertebrae. They subsequently rated overall image quality using a ten-point scale. RESULTS: For both protocols and at each disc level, IR significantly decreased image noise and increased SNR and CNR, compared with FBP. SNR and CNR were statistically equivalent in LD-IR and SD-FBP protocols. Regardless of the dose and disc level, the qualitative scores with IR compared with FBP, and with LD-IR compared with SD-FBP, were significantly higher or not statistically different for intervertebral discs, neural foramina and ligaments, while significantly lower or not statistically different for soft tissues and vertebrae. The overall image quality scores were significantly higher with IR compared with FBP, and with LD-IR compared with SD-FBP. CONCLUSION: LD-IR cervical spine CT provides better image quality for intervertebral discs, neural foramina and ligaments, and worse image quality for soft tissues and vertebrae, compared with SD-FBP, while reducing radiation dose by approximately 40 %.

Comparison of the power spectral changes of the voluntary surface electromyogram and M wave during intermittent maximal voluntary contractions.

INTRODUCTION: To compare the power spectral changes of the voluntary surface electromyogram (sEMG) and of the compound action potential (M wave) in the vastus medialis and vastus lateralis muscles during fatiguing contractions. METHODS: Interference sEMG and force were recorded during 48 intermittent 3-s isometric maximal voluntary contractions (MVC) from 13 young, healthy subjects. M waves and twitches were evoked using supramaximal femoral nerve stimulation between the successive MVCs. Mean frequency (F mean), and median frequency were calculated from the sEMG and M waves. Muscle fiber conduction velocity (MFCV) was computed by cross-correlation. RESULTS: The power spectral shift to lower frequencies was significantly greater for the voluntary sEMG than for the M waves (P < 0.05). Over the fatiguing protocol, the overall average decrease in MFCV (~25 %) was comparable to that of sEMG F mean (~22 %), but significantly greater than that of M-wave F mean (~9 %) (P < 0.001). The mean decline in MFCV was highly correlated with the mean decreases in both sEMG and M-wave F mean. CONCLUSIONS: The present findings indicated that, as fatigue progressed, central mechanisms could enhance the relative weight of the low-frequency components of the voluntary sEMG power spectrum, and/or the end-of-fiber (non-propagating) components could reduce the sensitivity of the M-wave spectrum to changes in conduction velocity.

In vitro activity of gallium maltolate against Staphylococci in logarithmic, stationary, and biofilm growth phases: comparison of conventional and calorimetric susceptibility testing methods.

Ga(3+) is a semimetal element that competes for the iron-binding sites of transporters and enzymes. We investigated the activity of gallium maltolate (GaM), an organic gallium salt with high solubility, against laboratory and clinical strains of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), methicillin-susceptible Staphylococcus epidermidis (MSSE), and methicillin-resistant S. epidermidis (MRSE) in logarithmic or stationary phase and in biofilms. The MICs of GaM were higher for S. aureus (375 to 2000 microg/ml) than S. epidermidis (94 to 200 microg/ml). Minimal biofilm inhibitory concentrations were 3,000 to >or=6,000 microg/ml (S. aureus) and 94 to 3,000 microg/ml (S. epidermidis). In time-kill studies, GaM exhibited a slow and dose-dependent killing, with maximal action at 24 h against S. aureus of 1.9 log(10) CFU/ml (MSSA) and 3.3 log(10) CFU/ml (MRSA) at 3x MIC and 2.9 log(10) CFU/ml (MSSE) and 4.0 log(10) CFU/ml (MRSE) against S. epidermidis at 10x MIC. In calorimetric studies, growth-related heat production was inhibited by GaM at subinhibitory concentrations; and the minimal heat inhibition concentrations were 188 to 4,500 microg/ml (MSSA), 94 to 1,500 microg/ml (MRSA), and 94 to 375 microg/ml (MSSE and MRSE), which correlated well with the MICs. Thus, calorimetry was a fast, accurate, and simple method useful for investigation of antimicrobial activity at subinhibitory concentrations. In conclusion, GaM exhibited activity against staphylococci in different growth phases, including in stationary phase and biofilms, but high concentrations were required. These data support the potential topical use of GaM, including its use for the treatment of wound infections, MRSA decolonization, and coating of implants.