Structural and functional integrity of spermatozoa is compromised as a consequence of acute uropathogenic E. coli-associated epididymitis.

Uropathogenic Escherichia coli (UPEC)-associated epididymitis is commonly diagnosed in outpatient settings. Although the infection can be successfully cleared using antimicrobial medications, 40% of patients unexplainably show persistent impaired semen parameters even after treatment. Our aim was to investigate whether pathogenic UPEC and its associated virulence factor hemolysin (hlyA) perturb the structural and functional integrity of both the epididymis and sperm, actions that may be responsible for the observed impairment and possibly a reduction of fertilization capabilities. Semen collected from patients diagnosed with E. coli-only related epididymitis showed that sperm counts were low 14 days postantimicrobial treatment regardless of hlyA status. At Day 84 following treatment, hlyA production correlated with approximately 4-fold lower sperm concentrations than in men with hlyA-negative strains. In vivo experiments with the hlyA-producing UPEC CFT073 strain in a murine epididymitis model showed that just 3 days postinfection, structural damage to the epididymis (epithelial damage, leukocyte infiltration, and edema formation) was present. This was more severe in UPEC CFT073 compared to nonpathogenic E. coli (NPEC 470) infection. Moreover, pathogenic UPEC strains prematurely activated the acrosome in vivo and in vitro. Raman microspectroscopy revealed that UPEC CFT073 undermined sperm integrity by inducing nuclear DNA damage. Consistent with these observations, the in vitro fertilization capability of hlyA-treated mouse sperm was completely abolished, although sperm were motile. These findings provide new insights into understanding the possible processes underlying clinical manifestations of acute epididymitis.

Oxidative DNA damage in human sperm can be detected by Raman microspectroscopy.

OBJECTIVE: To determine whether Raman microspectroscopy can identify different levels of oxidative sperm nDNA damage and to corroborate the findings using an established method and an alternative but complementary spectroscopic technique. DESIGN: Three-way comparison of Raman profiles, Fourier transform infrared spectroscopy (FTIR) spectra, and flow-cytometric assessments of sperm nDNA damage. SETTING: University-based research laboratory. PATIENT(S): Thirty-eight men attending the infertility clinic at the Centre of Reproductive Medicine and Andrology. INTERVENTION(S): Induction of oxidative damage by Fenton's reaction on semen samples. MAIN OUTCOME MEASURE(S): Raman profiles, FTIR spectra, and flow-cytometric analysis of DNA fragmentation. RESULT(S): Raman and FTIR spectra contained distinctive differences between untreated and fragmented nDNA sperm that were indicative of oxidative attack. The changes in Raman profiles were similar to those previously seen and corresponded to the DNA backbone. The peak attributions were corroborated by the FTIR spectra. Principal component analysis of the entire Raman spectra distinguished samples with varying degrees of damage. After determination of a cutoff value (0.63), estimation of the percentage of sperm with nDNA damage using the intensity ratio of Raman peaks (1,050/1,095 cm(-1)) correlated linearly to the flow-cytometric assessment. CONCLUSION(S): Raman microspectroscopy still requires further validation but may potentially provide a means of assessing the nDNA status of a living sperm.

List mode-driven cardiac and respiratory gating in PET.

UNLABELLED: Gating methods acquiring biosignals (such as electrocardiography [ECG] and respiration) during PET enable one to reduce motion effects that potentially lead to image blurring and artifacts. This study evaluated different cardiac and respiratory gating methods: one based on ECG signals for cardiac gating and video signals for respiratory gating; 2 others based on measured inherent list mode events. METHODS: Twenty-nine patients with coronary artery disease underwent a 20-min ECG-gated single-bed list mode PET scan of the heart. Of these, 17 were monitored by a video camera registering a marker on the patient's abdomen, thus capturing the respiratory motion for PET gating (video method). Additionally, respiratory and cardiac gating information was deduced without auxiliary measurements by dividing the list mode stream in 50-ms frames and then either determining the number of coincidences (sensitivity method) or computing the axial center of mass and SD of the measured counting rates in the same frames (center-of-mass method). The gated datasets (respiratory and cardiac gating) were reconstructed without attenuation correction. Measured wall thicknesses, maximum displacement of the left ventricular wall, and ejection fraction served as measures of the exactness of gating. RESULTS: All methods successfully captured respiratory motion and significantly decreased motion-induced blurring in the gated images. The center-of-mass method resulted in significantly larger left ventricular wall displacements than did the sensitivity method (P < 0.02); other differences were nonsignificant. List mode-based cardiac gating was found to work well for patients with high (18)F-FDG uptake when the center-of-mass method was used, leading to an ejection fraction correlation coefficient of r = 0.95 as compared with ECG-based gating. However, the sensitivity method did not always result in valid cardiac gating information, even in patients with high (18)F-FDG uptake. CONCLUSION: Our study demonstrated that valid gating signals during PET scans cannot be obtained only by tracking the external motion or applying an ECG but also by simply analyzing the PET list mode stream on a frame-by-frame basis.

Motion correction in respiratory gated cardiac PET/CT using multi-scale optical flow.

Respiratory motion is a source of degradation in positron emission tomography. As the patients cannot hold breath during the PET acquisition, spatial blurring and motion artifacts are unavoidable which may lead to wrong quantification of the data. A solution based on respiratory-gating and optical flow based correction of the PET data is proposed. This includes deformation of the CT data for accurate attenuation and listmode based reconstruction. All methods are applied to real patient data and are evaluated with respect to three criteria.

Three-dimensional architecture of the left ventricular myocardium.

Concepts for ventricular function tend to assume that the majority of the myocardial cells are aligned with their long axes parallel to the epicardial ventricular surface. We aimed to validate the existence of aggregates of myocardial cells orientated with their long axis intruding obliquely between the ventricular epicardial and endocardial surfaces and to quantitate their amount and angulation. To compensate for the changing angle of the long axis of the myocytes relative to the equatorial plane of the ventricles with varying depths within the ventricular walls, the so-called helical angle, we used pairs of cylindrical knives of different diameters to punch semicircular slices from the left ventricular wall of pigs, the slices extending from the epicardium to the endocardium. The slices were pinned flat, fixed in formaldehyde, embedded in paraffin, sectioned, stained with azan or hematoxilin and eosin, and analyzed by a new semiautomatic procedure. We made use of new techniques in informatics to determine the number and angulation of the aggregates of myocardial cells cut in their long axis. The alignment of the myocytes cut longitudinally varied markedly between the epicardium and the endocardium. Populations of myocytes, arranged in strands, diverge by varying angles from the epicardial surface. When paired knives of decreasing diameter were used to cut the slices, the inclination of the diagonal created by the arrays increases, while the lengths of the array of cells cut axially decreases. The visualization of the size, shape, and alignment of the myocytic arrays at any side of the ventricular wall is determined by the radius of the knives used, the range of helical angles subtended by the alignment of the myocytes throughout the thickness of the wall, and their angulation relative to the epicardial surface. Far from the majority of the ventricular myocytes being aligned at angles more or less tangential to the epicardial lining, we found that three-fifths of the myocardial cells had their long axes diverging at angles between 7.5 and 37.5 degrees from an alignment parallel to the epicardium. This arrangement, with the individual myocytes supported by connective tissue, might control the cyclic rearrangement of the myocardial fibers. This could serve as an important control of both ventricular mural thickening and intracavitary shape.

The relationship between structure and function: why does reshaping the left ventricle surgically not always result in functional improvement?

Surgical strategies recently introduced to improve ventricular function have been based on the concepts of reduction of ventricular diameter, synchronization of myocardial activity, passive support of diastolic ventricular shape, and active support of systolic ventricular constriction. They have depended on several established theoretical assumptions, not all of which are totally valid. Clinical results have proved markedly variable. This is especially true for procedures designed to reduce the radius of the left ventricle. Some have reported up to 80% mortality, whereas others achieve results comparable with those for heart transplantation. Because of this, the method runs the risk to be rejected, or else, its more widespread application will be postponed until essential details concerning the basic concepts have been elucidated. It is these details which we discuss in this review.