Andrology: Analysis of sperm movement in relation to the oxidative stress created by leukocytes in washed sperm preparations and seminal plasma

The addition of luminol to unprocessed semen samples resultedin the generation of chemiluminescent signals, the intensityof which was highly correlated with the level of leukocyte contamination.Despite the spontaneous oxidant-generating capacity of seminalleukocytes, no correlations were observed between leukocytecontamination and the fertility status of the subjects or anyaspect of the semen profile, including the motility of the spermatozoaor their performance in a hyaluronate penetration assay. Luminol-dependentchemiluminescence and leukocyte contamination were also correlatedin washed sperm suspensions prepared either by repeated centrifugationor on discontinuous Percoll gradients. However, in such spermsuspensions, the spontaneous generation of oxidants by contaminatingleukocytes (>2x10⁴ leukocytes/ml) was invariably associatedwith a decreased capacity for movement. Moreover, causativeassociations between leukocyte contamination, reactive oxygenspecies generation, lipid peroxidation and impaired sperm motilitywere revealed by experiments involving the selective additionor removal of activated leukocytes. From these observationswe can conclude that low concentrations of leukocytes are acommon feature of the human ejaculate and can impair sperm function,particularly in the absence of seminal plasma. These findingshave implications for our understanding of the importance ofleukocytospermia in defining the fertility of human spermatozoain vivo and in vitro.     

The "motion-blind" patient: low-level spatial and temporal filters

The "motion-blind" patient previously described by Zihl et al. (1983) was investigated using standard psychophysical procedures with stimuli whose spatial and temporal properties could be separately manipulated. Detection experiments for sinewave grating stimuli of varying spatial and temporal frequency showed sensitivity in this patient to be only slightly impaired. Temporal integration for stimuli of varying spatiotemporal frequency exhibited the expected space-time covariation seen in normal vision. An examination of the suprathreshold discriminative capacity of this patient was undertaken for spatial frequency, contrast, and temporal frequency. Although all of these discriminative functions were impaired, those concerning temporal frequency or velocity were dramatically reduced. No similar loss was seen for spatial frequency discrimination for moving or temporally varying stimuli. No measurable temporal frequency discrimination was present above 6 Hz and no velocity discrimination above 6 degrees/sec. Experiments involving the direction discrimination of suprathreshold drifting gratings of arrays of random dots revealed an inability to perceive direction of movement above a velocity of about 6 degrees/sec. Contrast thresholds contingent on direction of motion of a drifting grating also showed a much greater deficit than simple detection. Apparent motion using 2-flash random dot kinematograms revealed that the residual motion vision of this patient corresponded to the "short-range" motion process of normal vision. This process originally defined by Braddick (1974) operates over restricted space and time intervals. Apparent motion could only be supported by a narrow range of intermediate spatial displacements. These results suggest that this patient does exhibit some residual motion perception, probably corresponding to a severely impaired "short-range" mechanism. The patient's relatively intact ability to perform simple types of discrimination but severe impairment of performance at making judgments relevant to the nature of motion of the same stimuli suggests that while the components necessary for the analysis of motion are intact their more global associations have been disrupted. This implicates an extrastriate locus of the brain damage. Alternative explanations for the nature of the deficit are discussed.     

The latency of the cat vestibulo-ocular reflex before and after short- and long-term adaptation

Latencies of normal and adapted feline vestibulo-ocular reflex (VOR) were studied in five cats by applying ± 20°/s horizontal head velocity steps (4000°/s₂ acceleration) and measuring the elicited horizontal or vertical reflex eye responses. Normal VOR latency was 13.0 ms ± 1.9 SD. Short-term adaptation was then accomplished by using 2 h of paired horizontal sinusoidal vestibular stimulation and phase-synchronized vertical optokinetic stimulation (cross-axis adaptation). For long-term adaptation, cats wore ×0.25 or ×2.2 magnifying lenses for 4 days. The cats were passively rotated for 2 h/day and allowed to walk freely in the laboratory or their cages for the remainder of the time. The latency of the early (primary) adaptive response was 15.2ms±5.2 SD for crossaxis adaptation and 12.5 ms±3.9 SD for lens adaptation. This short-latency response appeared within 30 min after beginning the adaptation procedure and diminished in magnitude overnight. A late (secondary) adaptive response with latency of 76.8 ms±7.0 SD for cross-axis adaptation and 68.1 ms±8.8 SD for lens adaptation appeared after approximately 2 h of adaptation. It had a more gradual increase in magnitude than the primary response and did not diminish in magnitude overnight. These data suggest that brainstem VOR pathways are a site of learning for adaptive VOR modification, since the primary latency is short and has a similar latency to that of the normal VOR.     

Changes in the heparin neutralising activity of platelet poor plasma after immunisation.

Acute myocardial disease, which may be associated with abnormal platelet activity, has been reported after routine immunisation. Thirty-two army apprentices undergoing immunisation were studied for changes in the heparin neutralising activity (HNA) of platelet poor plasma. HNA increased after immunisation. This increase in HNA may represent an increase in platelet activation but may also relate to changes in acute phase proteins. These changes were not observed in elderly subjects undergoing immunisation with influenza vaccine.     

Influence of preimmunization antibody levels on the specificity of the immune response to related polysaccharide antigens

We studied the influence of preimmunization antibody level on the immune response of adults to one of two structurally related yet immunologically distinct type-specific polysaccharides from Type III Group B streptococcus and Type 14 pneumonococcus. Four weeks after immunization with multivalent pneumococcal vaccine, 20 subjects with low levels of antibody to Type III Group B streptococcus antigen had no significant increase in antibody to this antigen (P greater than 0.05), but all volunteers with moderate to high preimmunization antibody levels who were immunized with Pneumovax had significant increases (P less than 0.01). However, the streptococcal antibody response to pneumococcal Type 14 antigen was weaker and briefer than that in 10 adults given Type III Group B streptococcus vaccine(P less than 0.05). Preimmunization antibody levels influenced the immune response to a structurally similar polysaccharide antigen, but specific Type III polysaccharide antigen appeared necessary to induce a primary antibody response in "nonimmune" adults. We conclude that immunization of mothers with pneumococcal vaccine is not likely to prevent neonatal Type III Group B streptococcal infection, despite immunologic similarities between the two organisms.     

Phenotypic characteristics, fatty acid composition, and isoprenoid quinone content of CDC group IIg bacteria.

Eleven strains of eugonic, nonoxidative, gram-negative rods isolated from clinical specimens formed a distinct group that was designated CDC group IIg. Five of the 11 isolates were from wounds. The phenotypic characteristics of CDC group IIg were most similar to those of Weeksella species, with the major difference being that CDC group IIg strains grew on MacConkey agar in 1 to 2 days, did not hydrolyze gelatin, and did not produce urease. All 11 strains of CDC group IIg possessed a distinct fatty acid profile that was characterized by large amounts (19 to 29%) of 18:1 omega 7c, 16:0, and 16:1 omega 7c, moderate amounts (6 to 10%) of 3-OH-14:0 and 14:0, and smaller amounts (1 to 2%) of 18:2, 18:0, and 3-OH-16:0. This fatty acid profile differs from those of Weeksella species by the absence of branched-chain fatty acids. CDC group IIg contains ubiquinone-8, as opposed to menaquinone-6 in Weeksella species. The isolates were susceptible to a variety of antimicrobial agents, including the aminoglycosides, tetracyclines, quinolones, sulfonamides, and polymyxin B.     

Calcium ionophore-induced acrosome reaction correlates with fertilization rates in vitro in patients with teratozoospermic semen

The aim of this study was to determine the relationship between calcium ionophore A23187-induced acrosome reaction (AR) and sperm fertilizing ability. Semen samples remaining after preparation for standard IVF were studied in 109 patients who had sperm concentrations > or =20 x 10(6)/ml. Ionophore-induced AR was performed on motile spermatozoa selected by centrifugation on a Percoll gradient. Semen analysis was performed using standard methods. Patients with higher (>50%, n = 76) fertilization rates had significantly higher ionophore-induced AR than patients with lower (<50%, n = 33) fertilization rates (49 +/- 14 versus 38 +/- 21%, P < 0.05). When the data from all patients were analysed by logistic regression, only the percentage sperm motility in insemination medium and ionophore-induced AR were significantly related to fertilization rates. Similar results were also obtained when the data from a subgroup of patients with poor (<15% normal) sperm morphology were analysed. However, when patients with normal sperm morphology > or =15% were analysed separately, only sperm count and the percentage of spermatozoa with progressive motility in semen were significantly related to fertilization rates. In conclusion, ionophore- induced AR was significantly related to fertilization rates in vitro mainly in patients with teratozoospermic semen. Tests for ionophore- induced AR may provide additional information about sperm fertilizing ability but may not indicate specific defects of the physiological AR.      

Precise spatiotemporal repeating patterns in monkey primary and supplementary motor areas occur at chance levels

Precise spatiotemporal patterns in neural discharge are a possible mechanism for information encoding in the brain. Previous studies have found that such patterns repeat and appear to relate to key behavioral events. Whether these patterns occur above chance levels remains controversial. To address this question, we have made simultaneous recordings from between two and nine neurons in the primary motor cortex and supplementary motor area of three monkeys while they performed a precision grip task. Out of a total of 67 neurons, 46 were antidromically identified as pyramidal tract neurons. Sections of recordings 60 s long were searched for patterns involving three or more spikes that repeated at least twice. The allowed jitter for pattern repetition was 3 ms, and the pattern length was limited to 192 ms. In all 11 recordings analyzed, large numbers of repeating patterns were found. To assess the expected chance level of patterns, "surrogate" datasets were generated. These had the same moment-by-moment modulation in firing rate as the experimental spike trains, and matched their interspike interval distribution, but did not preserve the precise timing of individual spikes. The number of repeating patterns in 10 randomly generated surrogates was used to form 99% confidence limits on the repeating pattern count expected by chance. There was close agreement between these confidence limits and the number of patterns seen in the experimental data. Analysis of high complexity patterns was carried out in four long recordings (mean duration 23.2 min, mean number of neurons simultaneously recorded 7.5). This analysis logged only patterns composed of a larger number (7-11) of spikes. The number of patterns seen in the surrogate datasets showed a small but significant excess over those seen in the original experimental data; this is discussed in the context of surrogate generation. The occurrence of repeating patterns in the experimental data were strongly associated with particular phases of the precision grip task; however, a similar task dependence was seen for the surrogate data. When a repeating pattern was used as a template to find inexact matches, in which up to half of the component spikes could be missing, similar numbers of matches were found in experimental and surrogate data, and the time of occurrence of such matches showed the same task dependence. We conclude that the existence of precise repeating patterns in our data are not due to cortical mechanisms that favor this form of coding, since as many, if not more, patterns are produced by spike trains constructed only to modulate their firing rate in the same way as the experimental data, and to match the interspike interval histograms. The task dependence of pattern occurrence is explicable as an artifact of the modulation of neural firing rate. The consequences for theories of temporal coding in the cortex are discussed.     

Do proficiency test results correlate with the work performance of screeners who screen Papanicolaou smears?

We rescreened Papanicolaou smear slides from 40,245 women, which had been examined by 81 cytology screeners, scored the screeners' work performance, and compared these scores with the results of the screeners' performance on glass slide and computer-based proficiency tests. All diagnoses (i.e., from the proficiency tests, the original slides, and the rescreened slides) were classified in the 4 diagnostic categories specified in the Clinical Laboratory Improvement Amendments. The rescreening scores were standardized to account for different distributions of abnormalities in the proficiency tests and rescreened slides. We compared a standardized score with the proficiency test scores. Of the cases, 91% were categorized as normal, benign, or reactive changes when rescreened, and 98% of these agreed with the original diagnosis. Sixteen percent of low-grade and 15% of high-grade intraepithelial lesions were classified as normal. The rank correlation between the rescreening scores and both proficiency tests was 0.24 using a scoring scheme for cytotechnologists. The correlation between the rescreening and proficiency testing scores indicates that performance on a 10-slide test gives some indication of the true performance of screeners. The computer-based test shows promise as an alternative to the glass slide test but needs further development and validation.     

Two new species of Eimeria Schneider 1875 (Apicomplexa: Eimeriidae) from the broad-toothed field mouse, Apodemus mystacinus Danford and Alston 1877 (Rodentia: Muridae) from Jordan

Coprological examination of 40 Apodemus mystacinus Danford and Alston 1877 from Jordan revealed oocysts of three species of genus Eimeria. Two species are described as new. Eimeria zuhairamri sp. n. has broadly ellipsoidal oocysts 29.6 (27.0–34.0)×23.3 (22.0–25.0) m with distinctly granulated wall and oocyst residuum. Endogenous development occurs in jejunum and ileum. Eimeria alorani sp. n. has oocysts 26.9 (23.0–29.0)×19.3 (18.0–22.0) m with smooth wall and absent residuum. Endogenous development is confined to the caecum. The third species, developing in jejunum, has oocysts morphologically indistinguishable from Eimeria uptoni. The identity of E. uptoni and the taxonomy of Eimeria of Apodemus are discussed.