Zona opening with 308 nm XeCl excimer laser improves fertilization by spermatozoa from long-term vasectomized mice

Spermatozoa from long-term vasectomized mice have greatly reducedfertilizing ability in vivo and in vitro, which makes this auseful animal model for male factor infertility. The purposeof this study was to evaluate the 308 nm XeCl excimer laserfor opening the zona pellucida to enhance the fertilizationrate with spermatozoa from vasectomized males. Inseminatingzona-intact (control) oocytes with 5 x 10⁶ spermatozoa/ml resultedin only 6% fertilization and 33.3% development to the blastocyststage; zona-opened oocytes showed significant improvement with31.5% fertilization, 90% cleavage to the 2-cell stage, and 72.2%blastocyst formation. Out of the 130 oocytes in the experimentalgroup, zona ablation was performed successfully on 127 and onlythree were damaged. These results suggest that laser micromanipulationfor assisted fertilization potentially offers a simplified andprecise method for mechanical zona cutting.     

Infertility: Human decidua-associated protein hDP200 in menstrual fluid: comparison between fertile women and women after failed in-vitro fertilization/embryo transfer treatment

The concentration of human decidua-associated protein (hDP)200 was measured in 238 menstrual fluid samples obtained fromnormal fertile women and in 26 menstrual fluid samples obtainedfrom infertile women who failed to conceive and menstruatedfollowing in-vitro fertilization (IVF)/embryo transfer treatment.A significant association was observed between the concentrationof hDP200 and the age of the women. A maximal concentrationof hDP200 was observed in women aged 28–30 years, withsignificantly lower concentrations in those aged 18–20and 39–41 years. The presence of an intra-uterine devicehad no effect on menstrual fluid hDP200 concentrations. A significantlylower mean concentration of hDP200 (82 U/ml) was measured inmenstrual fluid samples obtained from failed IVF/embryo transferpatients as compared with that in menstrual fluid samples fromnormal fertile women (191 U/ml). These findings support theconcept that adequate endometrial function, as evaluated bymenstrual fluid concentration of hDP200, is important for thesuccess of the fertility process.     

Measurement of corneal endothelial impedance with non-invasive external electrodes--a theoretical study

The corneal endothelial cell layer function is critical for the maintenance of hydration and transparency of the cornea. Recent advances in corneal lamellar transplantation point to the need for reliable, non-invasive and rapid endothelial function assessment. Findings using an invasive electrode in an experimental animal model have suggested an association between bioimpedance parameters and endothelial cell function. Currently, however there is no clinical device that allows for non-invasive measurements of endothelial layer electrical impedance. This report is a finite element simulation study that models the human eye. It evaluates the feasibility of using external non-invasive electrodes to detect changes in endothelial layer electrical properties as a function of electrode location and measurement frequencies. The findings show that the ratio between the potential recorded at low and high frequencies is sensitive to changes in endothelial resistivity as well as endothelial capacitance. Moreover, the optimal electrode configuration yielding the highest sensitivity is one where the current injecting electrodes are oppose to each other and the voltage recording electrodes are adjacent to the current injecting electrodes. This first-order theoretical study suggests that a non-invasive device which measures electrical properties of the endothelial layer from the exterior of the eye could be developed. Clearly further animal and human studies are required to develop a reliable clinical tool.     

Restoration of retinal morphology and residual scarring after photocoagulation

Purpose: To study healing of retinal laser lesions in patients undergoing PRP using SD‐OCT. Methods: Moderate, light and barely visible retinal burns were produced in patients with proliferative diabetic retinopathy scheduled for PRP using 100‐, 20‐ and 10‐ms pulses of 532‐nm laser, with retinal spot sizes of 100, 200 and 400 μm. Lesions were measured with OCT at 1 hr, 1 week, 1, 2, 4, 6, 9 and 12 months. OCT imaging was correlated with histology in a separate study in rabbits. Results: Lesions produced by the standard 100‐ms exposures exhibited steady scarring, with the damage zone stabilized after 2 months. For 400‐ and 200‐μm spots and 100‐ms pulses, the residual scar area at 12 months was approximately 50% of the initial lesion size for moderate, light and barely visible burns. In contrast, lesions produced by shorter exposures demonstrated enhanced restoration of the photoreceptor layer, especially in smaller burns. With 20‐ms pulses, the damage zone decreased to 32%, 24% and 20% for moderate, light and barely visible burns of 400 μm, respectively, and down to 12% for barely visible burns of 200 μm. In the 100‐μm spots, the residual scar area of the moderate 100‐ms burns was 41% of the initial lesion, while barely visible 10‐ms burns contracted to 6% of the initial size. Histological observations in rabbits were useful for proper interpretation of the damage zone boundaries in OCT. Conclusions: Traditional photocoagulation parameters (400 μm, 100 ms and moderate burn) result in a stable scar similar in size to the beam diameter. Restoration of the damaged photoreceptor layer in lighter lesions produced by shorter pulses should allow reducing the common side‐effects of photocoagulation such as scotomata and scarring.     

The clinical significance of isolation of two different organisms from the urine of patients with an indwelling catheter

Background

We evaluated the clinical significance of urine cultures from patients with an indwelling urinary catheter (UC) from which 2 different pathogens were isolated.

Methods

Urine cultures from patients with a UC from which 2 different organisms were isolated were randomly divided into a control group (culture results were reported as usual) and a study group (culture results were reported as “mixed growth”). Endpoints included change in antibiotic treatment, use of broad spectrum agents, time for clinical improvement, and duration of admission.

Results

A total of 81 cultures met the inclusion criteria. Antibiotic treatment was changed after 72–96 h in 19 (48%) study patients and in 25 (61%) controls (NS). There was no difference regarding narrowing or broadening of antibiotic spectrum, and duration of hospitalization was similar. In each group, 15 (36%) patients died.

Conclusion

Our findings imply that laboratory work-up of 2 pathogens from patients with an indwelling catheter may be discarded.     

Safety and Immunogenicity of Multimeric-001—a Novel Universal Influenza Vaccine

Objective

A new vaccine, Multimeric-001, containing conserved linear epitopes from the HA, NP, and M1 proteins of influenza type A and type B strains was designed to protect against seasonal and pandemic influenza virus strains, regardless of mutations. We assessed its safety and tolerability and characterized humoral and cellular immune responses elicited by its administration.

Methods

Sixty healthy volunteers received either 250 or 500 μg injections, with or without adjuvant (Montanide ISA 51VG), or matching placebo. Two intramuscular injections were administered, 21 days apart.

Results

Treatment was well tolerated and no significant adverse events were noted. Forty-two days after first injection, there was a 50-fold and 37-fold increase in IgG titers against Multimeric-001 protein, following the adjuvanted 500 and 250 μg doses, respectively. Sera from immunized subjects lysed MDCK cells infected with strains of influenza representing the major strains that infect humans: H1N1, H3N2, and influenza B. Proliferation of peripheral blood mononuclear cells as well as increase in IL-2 and IFN-gamma secretion occurred following incubation with the vaccine.

Conclusion

This vaccine model differs fundamentally from the current influenza virus vaccines, as it does not contain the variable regions of the virus hemagglutinin and hence does not induce hemagglutination inhibition antibodies that serve as surrogate markers for protection. In order to demonstrate the potential efficacy of the Multimeric-001, an alternative assay was employed, in which the lysis of MDCK cells infected with different virus strains was shown, with the involvement of the complement mechanism. The humoral and cellular responses suggest a cross-immunity of the vaccine toward influenza virus strains regardless of mutations. These results corroborate the protective effect of the vaccine, previously shown in animals. Larger-scale studies are under way to further substantiate the safety and efficacy of the vaccine candidate.     

From the Cover: Bats adjust their mouth gape to zoom their biosonar field of view

Active sensing, where sensory acquisition is actively modulated, is an inherent component of almost all sensory systems. Echolocating bats are a prime example of active sensing. They can rapidly adjust many of their biosonar parameters to optimize sensory acquisition. They dynamically adjust pulse design, pulse duration, and pulse rate within dozens of milliseconds according to the sensory information that is required for the task that they are performing. The least studied and least understood degree of freedom in echolocation is emission beamforming—the ability to change the shape of the sonar sound beam in a functional way. Such an ability could have a great impact on the bat’s control over its sensory perception. On the one hand, the bat could direct more energy into a narrow sector to zoom its biosonar field of view, and on the other hand, it could widen the beam to increase the space that it senses. We show that freely behaving bats constantly control their biosonar field of view in natural situations by rapidly adjusting their emitter aperture—the mouth gape. The bats dramatically narrowed the beam when entering a confined space, and they dramatically widened it within dozens of milliseconds when flying toward open space. Hence, mouth-emitting bats dynamically adjust their mouth gape to optimize the area that they sense with their echolocation system.The ability to actively adjust sensory acquisition is a key feature of almost all sensory systems. A capability to selectively control the sensory “field of view” could have a major impact on sensory perception. It would allow an animal to adjust the amount of acquired information in a task-dependent manner, zooming in on an object of interest and zooming out when a wider sector should be sensed. Many animals can shift their sensory attention (e.g., by changing gaze) or their focal plane (e.g., human vision), but there are no animals that are known to constantly adjust their sensory field of view under natural conditions. Echolocating bats perceive their environment acoustically by emitting ultrasonic pulses and analyzing the received echoes (1). The volume of space that is covered by the sound pulse and therefore, sensed by the bat depends on the emitted beamform—the spatial shape of the emission (2–9). Bats could potentially benefit greatly if they could change the form of their emitted beam in a functional manner, a property usually referred to in engineering as beamforming (10).Jakobsen and coworkers (11) recently summarized some of the reasons why a bat might narrow its biosonar beam. These reasons include (i) focusing sound into a narrower sector to improve the localization of objects, (ii) eliminating undesired echoes from the back or the sides of the bat, and (iii) increasing the sensing range by directing more energy forward. All of these come with a cost of reducing the volume of space that is scanned by the bat. It is, therefore, reasonable to expect that a bat would widen its beam under certain conditions, such as when scanning its surroundings during orientation or navigation.Most echolocating bats emit sound through the mouth (12). The biosonar beam of these bats can be modeled using the “piston model,” which represents a piston-shaped emitter in an infinite baffle (13). According to the piston model (and other emission models as well), a bat can adjust its beam by altering one of two parameters. First, it can change the spectral content of the sound pulse. Increasing the frequency would result in a narrower beam. Several bats that use frequency-modulated pulses seem to use this strategy at the terminal part of an attack on prey (3). Second, the bat can potentially change the aperture of its emitter. By opening its mouth wider, it can narrow the beam and vice versa. However, there is currently no direct evidence that bats change the emitter aperture for beamforming in this way.We studied beamforming in mouth-emitting Bodenheimer''s pipistrelle bats (Hypsugo bodenheimeri) under natural field conditions as well as in a controlled experimental setup. We started by recording and photographing bats as they came to drink at a small desert pond using an array of 12 ultrasonic microphones and a multiflash photography setup. Drinking on the wing requires fine maneuvering skills, which could benefit from active sensory adjustments (14, 15). When descending toward the pond and then ascending from it, the bats had to enter a confined space and then leave it, rapidly changing the degree of clutter around them—the density of nearby objects creating undesired echoes. To deal with these sensory challenges, we predicted that bats will alter their beamform while descending into the confined space or later, ascending out of it using one (or both) of the two mechanisms mentioned above. We used the audio recordings to reconstruct the bats’ emitted beams, and we measured their corresponding mouth gape in the images so that we could assess if and how bats control the beamform. To validate that our results were not a consequence of the drinking per se, we performed a second controlled experiment in which bats flew through a narrow (0.5 × 0.5-m² cross-section) 1.5-m-long tunnel and emerged from it into an open space environment (with less background echoes). We photographed the bats in flight to analyze their mouth gape and simultaneously recorded their echolocation pulses.We found that bats actively adjusted their beam by changing their mouth gape (i.e., the size of the emitter). Bats widened their mouth when entering a more confined cluttered environment, thus dramatically narrowing their beam width, and they narrowed the gape when flying toward the open, thus dramatically widening their beam. Bats that flew through a confined tunnel exhibited the same behavior—widening their mouth gape inside the tunnel and narrowing it when emerging into open space. We argue that this behavior aimed to functionally control the volume of the environment sensed by the bat to improve sensing—decreasing the scanned volume when entering a confined space and increasing it when flying into open space.