Insulin dependant diabetes mellitus: implications for male reproductive function

BACKGROUND

Diabetes mellitus (DM) is increasing in men of reproductive age. Despite this, the prevalence of diabetes in men attending fertility clinics is largely unknown. Furthermore, studies examining the effects of DM on sperm fertility potential have been limited to conventional semen analysis.

METHODS

Conventional semen analysis (semen volume, sperm count, motility and morphology) was performed for 27 diabetic (mean age 34+/-2 years) and 29 non-diabetic subjects (control group, men undergoing routine infertility investigations, mean age 33+/-1 years). Nuclear DNA (nDNA) fragmentation was assessed using the alkaline Comet assay and mitochondrial DNA (mtDNA) deletions by Long-PCR.

RESULTS

Other than a small, but significant, reduction in semen volume in diabetic men (2.6 versus 3.3 ml; P<0.05), conventional semen parameters did not differ significantly from control subjects. Diabetic subjects had significantly higher mean nDNA fragmentation (53 versus 32%; P<0.0001) and median number of mtDNA deletions (4 versus 3; P<0.05) compared with control subjects.

CONCLUSIONS

Diabetes is associated with increased sperm nuclear and mtDNA damage that may impair the reproductive capability of these men.

The effects of cryopreservation on sperm morphology, motility and mitochondrial function

BACKGROUND

The effects of cryoinjury were determined simultaneously on the mitochondrial function, motility, morphology and viability of ejaculated human sperm.

METHOD

Rhodamine 123 (R123) uptake (% of sperm) and stain intensity were used to determine sperm mitochondrial activity before and after cryopreservation from the semen of 50 men attending for infertility investigation. Morphology was assessed using Tygerberg's strict criteria and viability was assessed by eosin Y. Sperm motility was measured using computer-assisted semen analysis (CASA).

RESULTS

Freeze-thawing caused a 37% (P = 0.001) reduction in normal morphological forms of sperm. All CASA sperm motility parameters except amplitude of lateral head displacement were similarly reduced. R123 uptake and intensity within sperm mitochondria decreased by 36 and 47% respectively (both P = 0.001). In addition, there was a similar significant decrease (31%, P = 0.001) in the viability of the sperm.

CONCLUSIONS

Sperm morphology, motility, mitochondrial activities and viability are equally susceptible to cryopreservation-induced damage. R123 intensity is a novel and robust indicator of mitochondrial function before and after such trauma.

Vascular endothelial growth factor as capillary permeability agent in ovarian hyperstimulation syndrome

We investigated the role of vascular endothelial growth factor (VEGF) in ovarian hyperstimulation syndrome (OHSS). Two similar peaks of permeability activity were seen in OHSS ascites and liver ascites spiked with recombinant human VEGF (rhVEGF); no activity was seen in control liver ascites. Incubation with rhVEGF antiserum decreased activity in the two OHSS peaks by 79% and 65% and the two spiked liver peaks by 49% and 50%. Control serum produced 24% and 27%, and 17% and 0% reductions, respectively. This is evidence that the major capillary permeability agent in OHSS ascites fluid is VEGF.

An ergonomic analysis of the fulcrum effect in the acquisition of endoscopic skills

BACKGROUND

The loss of three-dimensional visual depth cues has been thought to be the main hindrance to the acquisition of endoscopic skills. However, the "fulcrum effect" of the abdominal wall on the manipulation of instruments has not to our knowledge been previously investigated.

METHODS

Subjects with no experience in endoscopy were required to make multiple defined incisions under laparoscopic laboratory conditions, within ten two-minute periods in the first study and 50 in the second. Eleven subjects operated under normal imaging conditions and 11 with the y-axis inverted.

RESULTS

Subjects who operated with the image inverted made significantly more incisions and significantly more correct incisions than those working under normal conditions. This effect persisted over 50 trials.

CONCLUSIONS

The fulcrum effect has a major detrimental influence on acquisition of endoscopic skills. Further work is required to investigate the role of image inversion in clinical endoscopic training.

Assessment of DNA integrity and morphology of ejaculated spermatozoa from fertile and infertile men before and after cryopreservation

Cryopreservation of human spermatozoa is extensively used in artificial insemination and IVF programmes. Despite various advances in cryopreservation methodology, the recovery rate of functional post-thaw spermatozoa remains mediocre, with sperm motility being significantly decreased after freezing. This aim of this study was to investigate the effects of cryopreservation on both DNA integrity and morphology of spermatozoa from fertile and infertile men. Semen samples were obtained from 17 fertile and 40 infertile men. All samples were prepared by discontinuous Percoll density centrifugation (95.0:47.5). Samples were divided into aliquots to allow direct comparison of fresh and frozen spermatozoa from the same ejaculate. Aliquots for cryopreservation were mixed with a commercial cryoprotectant and frozen by static phase vapour cooling before plunging into liquid nitrogen. Thawing was carried out slowly at room temperature. Sperm DNA integrity was determined using a modified alkaline single cell gel electrophoresis (comet) assay and sperm morphology analysed using the Tygerberg criteria. DNA of semen and prepared spermatozoa from fertile men was found to be unaffected by cryopreservation. In marked contrast, spermatozoa from infertile men were significantly damaged by freeze-thawing. Cryopreservation had a detrimental effect on morphology of semen and prepared samples from fertile and infertile men.

Objective psychomotor skills assessment of experienced, junior, and novice laparoscopists with virtual reality

Objective assessment of psychomotor skills in surgery is now a priority; however, this assessment is difficult to achieve because of measurement difficulties associated with the reliability and validity of assessing surgical skills in vivo and in the laboratory. In this study virtual reality (VR) was used to overcome these problems in the objective psychomotor assessment of senior, junior, and novice laparoscopists. Twelve experienced laparoscopic surgeons (performed >50 Minimal Access Surgery (MAS) procedures), 12 inexperienced laparoscopic surgeons (<10 MAS procedures), and 12 laparoscopic novices (no MAS procedures) participated in the study. Each subject completed all six tasks of the Minimally Invasive Surgical Trainer; Virtual Reality (MIST VR). In comparison to the other groups, experienced laparoscopic surgeons performed the tasks significantly (p < 0.01) faster, had a lower error rate, were more economic in their movement of surgical instruments and in the use of diathermy. As a group they also showed greater consistency in their performance. MIST VR distinguished between the three groups of laparoscopists. VR provides a useful objective assessment tool for evaluating psychomotor skills for laparoscopic surgery.

Virtual reality training in laparoscopic surgery: a preliminary assessment of minimally invasive surgical trainer virtual reality (MIST VR)

BACKGROUND

The "fulcrum effect" of the body wall on surgical instrument manipulation is a major hurdle for novice endoscopic surgeons. Virtual reality training has not previously been evaluated as a means to overcome this problem.

MATERIALS AND METHODS

16 participants with no experience of endoscopy were required to make multiple defined incisions under laparoscopic laboratory conditions within 2-minute periods. Half of the subjects were randomized to receive initial training on the Minimally Invasive Surgical Trainer, Virtual Reality (MIST VR) computer programme.

RESULTS

Participants with MIST VR training made significantly more correct incisions (P = 0.0001) than the control group on test trial 1, and even after extended practice by both groups (P = 0.0001). They were also significantly more likely to actively use both hands to perform the endoscopic evaluation task (P = 0.01).

CONCLUSIONS

Virtual reality training represents a potential, viable solution for junior endoscopists, for overcoming the "fulcrum effect", in a replicable, safe learning environment which allows objective and reliable quantification of skill levels by trainers.

Differences in nuclear DNA fragmentation and mitochondrial integrity of semen and prepared human spermatozoa

Sperm DNA integrity is essential for accurate transmission of genetic material to offspring. Fragmentation of genomic DNA is an initial hallmark of apoptosis (programmed cell death). The aim of this study was to determine sperm nuclear DNA integrity and mitochondrial function, to quantify possible apoptosis and to investigate any relationship between these parameters. Semen samples (n = 25) were prepared by discontinuous Percoll density centrifugation (95.0:47.5). DNA integrity was determined using a modified alkaline single cell gel electrophoresis (Comet) assay. DNA fragmentation, possibly indicative of apoptosis, was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL). Mitochondrial transmembrane potential was determined using the mitochondrial probe 5,5',6,6'-tetrachloro-1,1', 3,3'-tetraethylbenzimidazolyl carbocyanine iodide (JC-1). The DNA integrity of prepared spermatozoa was significantly greater than that of semen (P < 0.005). Further, the percentage of spermatozoa with fragmented DNA and the degree of fragmentation within these cells in prepared spermatozoa is significantly less than in semen (P < 0.005). There is a significant correlation between DNA damage quantified using the Comet assay and DNA fragmentation determined using TUNEL (R = 0.562, P < 0.01). The percentage of spermatozoa with dysfunctional, possibly apoptotic, mitochondria was significantly lower in prepared spermatozoa than in neat semen samples (P < 0.001). There was a negative correlation between the percentage of spermatozoa with dysfunctional mitochondria and the percentage of progressively motile spermatozoa (R = -0.67, P < 0.01).

Soluble vascular endothelial growth factor receptor-1 (sFlt-1) is increased throughout gestation in patients who have preeclampsia develop

OBJECTIVE

This study was undertaken to analyze prospectively circulating vascular endothelial growth factor (VEGF) and its soluble receptor, (s) Flt-1, throughout normotensive and preeclamptic pregnancies and to assess the importance of these proteins in the development of preeclampsia.

STUDY DESIGN

In this longitudinal cohort study, serum samples were collected from recruited subjects throughout pregnancy at 12, 20, 30, and 37 weeks and in the 24 hours before and after delivery. Subjects were divided retrospectively into normotensive and preeclamptic groups. Circulating VEGF and sFlt-1 concentrations were analyzed by radioimmunoassay and enzyme-linked immunosorbent assay, respectively.

RESULTS

Circulating sFlt-1 and VEGF significantly increased as gestation progressed and both were further elevated in preeclampsia compared with normotensive pregnancy. Soluble Flt-1 concentrations were elevated early in gestation and were significantly increased at 30 weeks' gestation in those who subsequently developed preeclampsia.

CONCLUSION

These results indicate a definite association between elevated sFlt-1 concentrations and the onset of preeclampsia suggesting that sFlt-1 is linked with disease pathogenesis.

Cryopreservation of human semen and prepared sperm: effects on motility parameters and DNA integrity

OBJECTIVE

To investigate effects of cryopreservation on sperm motility and DNA integrity.

DESIGN

Pre-cryopreservation and post-cryopreservation analysis of motility and DNA integrity of semen and prepared sperm samples.

SETTING

A hospital andrology laboratory.

PATIENT(S)

Forty men attending the Regional Fertility Centre, Belfast, Northern Ireland.

INTERVENTION(S)

Each sample was divided, and an aliquot was frozen unprepared. Remaining aliquots were prepared by Percoll density centrifugation (95.0:47.5) or direct swim-up procedure and divided into aliquots to allow direct comparison of fresh and frozen semen and prepared sperm (frozen with or without the addition of seminal plasma) from the same ejaculate. Samples were frozen by static-phase vapor cooling and being plunged into liquid nitrogen. Thawing was carried out at room temperature.

MAIN OUTCOME MEASURE(S)

Sperm DNA integrity was determined using a modified alkaline single cell gel electrophoresis (comet) assay, and motility was determined using computer-assisted semen analysis.

RESULT(S)

Sperm frozen unprepared in seminal fluid appeared more resistant to freezing damage than frozen prepared sperm. Further improvements can be achieved by selecting out the subpopulation of sperm with best motility and DNA integrity and freezing these sperm in seminal plasma, making this the optimal procedure.

CONCLUSION(S)

Freezing sperm in seminal plasma improves postthaw motility and DNA integrity.

The effect of ascorbate and alpha-tocopherol supplementation in vitro on DNA integrity and hydrogen peroxide-induced DNA damage in human spermatozoa

The aim of this study was to determine the effects of supplementation with ascorbate and alpha-tocopherol, both singly and in combination, during sperm preparation on subsequent sperm DNA integrity, induced DNA damage and reactive oxygen species (ROS) generation. Semen samples with normozoospermic and asthenozoospermic profiles (n = 15 for each control and antioxidant group) were prepared by Percoll density centrifugation (95.0-47.5%) where the medium had been supplemented with these antioxidants to a number of different concentrations, all within physiological levels. Controls were included which had no ascorbate or alpha-tocopherol added. DNA damage was induced using hydrogen peroxide (H(2)O(2)) and DNA integrity was determined using a modified alkaline single cell gel electrophoresis (Comet) assay, while ROS generation was measured using chemiluminescence. Addition of ascorbate to sperm preparation medium did not affect baseline DNA integrity but did provide sperm with complete protection against H(2)O(2)-induced DNA damage. Generation of H(2)O(2)-induced ROS was also significantly reduced after treatment with ascorbate, although baseline levels were unaffected by this antioxidant. Supplementation of sperm preparation medium with alpha-tocopherol did not influence baseline DNA integrity but provided sperm with dose-dependent protection against H(2)O(2)-induced DNA damage. Generation of H(2)O(2)-induced ROS was significantly reduced after treatment with alpha-tocopherol, although baseline ROS levels were unaffected by this antioxidant. Addition of both ascorbate and alpha-tocopherol in combination to sperm preparation medium actually induced DNA damage and intensified the damage induced by H(2)O(2), however, H(2)O(2)-induced ROS production was significantly reduced in a dose-dependent manner by supplementation with both vitamins.

Glutathione and hypotaurine in vitro: effects on human sperm motility, DNA integrity and production of reactive oxygen species

Sperm DNA integrity is of paramount importance for the accurate conveyance of genetic material. DNA damage may be a major contributory factor in male infertility as DNA from sperm of infertile men has been found to be more susceptible to induced DNA damage in vitro than DNA from fertile men. Reactive oxygen species (ROS) are a significant source of DNA damage and human sperm are extremely sensitive to ROS attack due to their high content of polyunsaturated fatty acids and lack of capacity for DNA repair. Seminal plasma, which contains a wealth of antioxidants, provides sperm with crucial protection against oxidative insult. However, during preparation for use in assisted conception techniques, sperm are separated from seminal plasma and deprived of that essential protection. The aim of this study was to determine the effects of supplementation with glutathione and hypotaurine during sperm preparation on subsequent sperm motility, DNA integrity, induced DNA damage and ROS generation. Semen samples (n = 45) were divided into aliquots and prepared by Percoll density centrifugation (95.0-47.5%) using medium which had been supplemented with these antioxidants to a number of different concentrations all within physiological levels. Control aliquots were included which had no glutathione or hypotaurine added. Sperm motility was determined using computer-assisted semen analysis. DNA damage was induced using H(2)O(2) and DNA integrity was determined using a modified alkaline single cell gel electrophoresis (Comet) assay, while ROS generation was measured using chemiluminescence. Addition of glutathione and hypotaurine, either singly or in combination, to sperm preparation medium had no significant effect on sperm progressive motility or baseline DNA integrity. Despite this, sperm were still afforded significant protection against H(2)O(2)-induced damage and ROS generation.

Antioxidant supplementation in vitro does not improve human sperm motility

OBJECTIVE

To determine the effects of supplementation of preparation media with ascorbate and alpha-tocopherol on subsequent sperm motility and reactive oxygen species production.

DESIGN

Prospective study to analyze postpreparation human sperm motility parameters and reactive oxygen species production following antioxidant supplementation.

SETTING

Andrology Laboratory, Royal Maternity Hospital, Belfast, Northern Ireland.

PATIENT(S)

Sixty patients attending the Andrology Laboratory for semen analysis.

INTERVENTION(S)

Normozoospermic and asthenozoospermic semen samples (n = 10 for each control and antioxidant group) were prepared by Percoll density centrifugation (95%-47.5%) in media supplemented with ascorbate or alpha-tocopherol to different concentrations within physiologic levels. Controls were included that were not exposed to antioxidant.

MAIN OUTCOME MEASURE(S)

Sperm motility parameters were assessed using computer-assisted semen analysis. The generation of reactive oxygen species was determined using luminol-dependent chemiluminescence.

RESULT(S)

The production of reactive oxygen species by sperm was reduced by supplementation in vitro with ascorbate and alpha-tocopherol. However, progressive motility, average path velocity, curvilinear velocity, straight-line velocity, and linearity were decreased significantly, with the greatest inhibition observed with the highest concentrations of antioxidants.

CONCLUSION(S)

Supplementation of preparation media with ascorbate and alpha-tocopherol, either singly or in combination, is not beneficial to sperm motility.

Serum levels of vascular endothelial growth factor in preeclamptic and normotensive pregnancy

The purpose of these studies was first to determine if vascular endothelial growth factor (VEGF), a vascular permeability agent, is increased in the serum of women with preclinical and clinical preclampsia (PE), and second to determine how these levels change after delivery. Twenty preeclamptic and 25 normotensive women at term consented to have blood taken pre- and post-delivery. Ten preeclamptic, 10 gestational hypertensive, and 28 normotensive women had blood collected respectively at 12, 20, and 30 weeks gestation and predelivery. Serum was extracted from all samples, and VEGF concentrations were determined by radioimmunoassay. Predelivery, the median serum VEGF concentration in the preeclamptic group was 51.7 ng/mL, and in the control group the concentration was 13.9 ng/mL (P<0.0001). Serum VEGF concentrations fell within 24 hours of delivery in both groups, which resulted in median values of 3.8 ng/mL and 3.2 ng/mL respectively (P<0.3). At 12 and 20 weeks, there was no significant difference between the serum VEGF concentrations in the 3 groups (P<0.3, 0.052 respectively). At 30 weeks, prior to the onset of clinical PE, the serum VEGF levels in the eventual preeclamptic group were elevated significantly compared with the gestational hypertensive and normotensive groups (P<0.001). Predelivery serum VEGF concentrations were significantly elevated in the preeclamptic group and were similar to those in the first study (P<0.0001). These findings suggest that VEGF may be important in the pathophysiology of PE and has the potential to act as a preclinical marker for the condition.

Distribution of the receptor for advanced glycation end products in the human male reproductive tract: prevalence in men with diabetes mellitus

BACKGROUND

Diabetics have a significantly higher percentage of sperm with nuclear DNA (nDNA) fragmentation and increased levels of advanced glycation end products (AGEs), in their testis, epididymis and sperm. As the receptor for AGEs (RAGE) is important to oxidative stress and cell dysfunction, we hypothesise, that it may be involved in sperm nDNA damage.

METHODS

Immunohistochemistry was performed to determine the presence of RAGE in the human testis and epididymis. A comparison of the receptor's incidence and localization on sperm from 10 diabetic and 11 non-diabetic men was conducted by blind semi-quantitative assessment of the immunostaining. Enzyme-linked immunosorbent assay analysis ascertained RAGE levels in seminal plasma and sperm from 21 diabetic and 31 non-diabetic subjects. Dual labelling immunolocalization was employed to evaluate RAGE's precise location on the sperm head.

RESULTS

RAGE was found throughout the testis, caput epididymis, particularly the principle cells apical region, and on sperm acrosomes. The number of sperm displaying RAGE and the overall protein amount found in sperm and seminal plasma were significantly higher in samples from diabetic men (P < 0.01, P < 0.0001 and P < 0.0001, respectively).

CONCLUSIONS

The presence of RAGE implies that it may play a central role in sperm nDNA damage particularly in diabetic men where the levels are elevated.

Virtual reality training leads to faster adaptation to the novel psychomotor restrictions encountered by laparoscopic surgeons

BACKGROUND

The fulcrum effect of the body wall on instrument handling poses a major obstacle to the mastery of instrument coordination for junior laparoscopic surgeons. This study evaluated three types of laparoscopic simulator training to assess their ability to promote the user's adaptation to the fulcrum effect.

METHODS

Thirty-two participants with no previous experience in laparoscopic surgery were randomly assigned to one of four groups representing different training conditions. One group was assigned to use a virtual reality simulator (MIST VR); two others were given a laparoscopic Z or U maze-tracking task. The control group received no training. Subjects were asked to perform a 2-min laparoscopic cutting task under normal laparoscopic imaging conditions first before and then after training.

RESULTS

In the test trial, subjects who trained on MIST VR made significantly more correct incisions (p < 0.0001) and fewer incorrect incisions (p < 0.0001).

CONCLUSION

Training on a virtual reality simulator such as MIST VR helps laparoscopic novices adapt to the fulcrum effect faster.

A comparison of DNA damage in testicular and proximal epididymal spermatozoa in obstructive azoospermia

Testicular and epididymal spermatozoa are used routinely for intracytoplasmic sperm injection (ICSI) to treat men with obstructive azoospermia. Little is known of the effects of obstruction and stasis on the DNA of these spermatozoa, particularly in the epididymis where spermatozoa have been retained for long periods. Surgical epididymal aspiration for ICSI could provide spermatozoa that are senescent or dying. Using the Comet assay, the percentage of undamaged DNA of testicular spermatozoa from 20 men with obstructive azoospermia was significantly better (83.0 +/- 1. 2%) than from proximal epididymal spermatozoa (75.4 +/- 2.3%; P < 0. 05). There was no difference between the percentage of undamaged DNA of testicular spermatozoa from 39 men with obstructive azoospermia (84.0 +/- 0.9) or from 10 fertile men at vasectomy (86.8 +/- 1.8) or from ejaculated spermatozoa from five of the controls (78.9 +/- 3.9; P > 0.05). In nine subjects, a second biopsy was carried out 6 months later. There was no significant difference in undamaged DNA on these two occasions (83.5 +/- 5.6 and 84.1 +/- 4.2; P > 0.05). This confirms the reproducibility of the Comet assay for non-ejaculated spermatozoa. Our data suggest that testicular sperm DNA appears to be significantly less damaged than epididymal sperm DNA, and so testicular spermatozoa should be used in preference for ICSI to treat men with obstructive azoospermia.

Effects of delta-9-tetrahydrocannabinol, the primary psychoactive cannabinoid in marijuana, on human sperm function in vitro

OBJECTIVE

To investigate effects of delta-9-tetrahydrocannabinol (THC) on human sperm function in vitro.

DESIGN

Laboratory analysis of sperm motility after exposure to THC using computer-assisted semen analysis and acrosome reaction by fluoroscein isothiocyanate-labeled peanut agglutinin staining.

SETTING

An assisted reproductive technology unit.

PATIENT(S)

Seventy-eight male patients.

INTERVENTION(S)

Sperm were divided into 90% (the best fertilizing potential used in assisted conception) and 45% (the poorer subpopulation) fractions by density centrifugation and incubated with THC at concentrations equivalent to therapeutic (0.032 microM) and recreational (0.32 and 4.8 microM) plasma levels at 37 degrees C for 3 h.

MAIN OUTCOME MEASURE(S)

Sperm motility and spontaneous and induced acrosome reactions.

RESULT(S)

Percentage progressive motility was decreased dose dependently in the 90% fraction (by 2%-21%; P<.05; P<.001). The 45% fraction showed a greater decrease in percentage progressive motility (by 28% at 0.032 microM; 56% at 4.8 microM; P=.004 and P=.01 res). Straight line velocity and the average path velocity also were reduced (by 10%, in the 90% LAYER) in both fractions. Spontaneous acrosome reactions were reduced in the 90% (17% at 0.032 microM, 35% at 4.8 microM P=.004 and P<.001 resp) and more markedly in the 45% fractions (17%-35%; P<.001). When the acrosome reaction was artificially induced (90% fraction) by A23187, THC (4.8 microM) resulted in a 57% inhibition (P<.001).

CONCLUSION(S)

The use of THC as a recreational drug may adversely affect male fertility.

Experienced laparoscopic surgeons are automated to the "fulcrum effect": an ergonomic demonstration

BACKGROUND AND STUDY AIMS

The inversion of the normal laparoscopic image around the Y-axis has been shown to facilitate the rate of learning of a laparoscopic task in novice subjects. The aim of this study was to investigate the effect of Y-axis image inversion on the performance of experienced laparoscopic surgeons; this had not been previously investigated.

METHODS

A total of 16 experienced surgeons,who had already carried out more than 50 operative laparoscopic procedures, and 16 novice participants, who had carried out no procedures, were required to make multiple defined incisions under laparoscopic laboratory conditions within ten 1-minute periods. Participants were randomly allocated to perform the task under either normal or Y-axis inverted imaging conditions (eight experienced surgeons and eight novices in each condition).

RESULTS

Y-axis inversion had a significant detrimental effect on the performance of the surgeons, whilst facilitating the performance of novices. The surgeons however, adapted to the inverted condition rapidly, showing a significant improvement in performance over the ten trials.

CONCLUSIONS

The Y-axis-inverted image has a detrimental effect on the performance of experienced surgeons, indicating that they have automated to the "fulcrum effect" of the abdominal wall on instrument manipulation. Y-axis-image inversion was found to facilitate significant learning trends, regardless of the participants' level of experience.

A comparison between randomly alternating imaging, normal laparoscopic imaging, and virtual reality training in laparoscopic psychomotor skill acquisition

OBJECTIVES

To evaluate virtual reality as a laparoscopic training device in helping surgeons to automate to the "fulcrum effect" by comparing it to time-matched training programs using randomly alternating images (ie, y-axis inverted and normal laparoscopic) and normal laparoscopic viewing conditions.

METHODS

Twenty-four participants (16 females and 8 males), were randomly assigned to minimally invasive surgery virtual reality (MIST VR), randomly alternating (between y-axis inverted and normal laparoscopic images), and normal laparoscopic imaging condition. Participants were requested to perform a 2-minute laparoscopic cutting task before and after training.

RESULTS

In the test trial participants who trained on the MIST VR performed significantly better than those in the normal laparoscopic and randomly alternating imaging conditions.

CONCLUSION

The results show that virtual reality training may provide faster skill acquisition with particular reference to automation of the fulcrum effect. MIST VR provides a new way of training laparoscopic psychomotor surgical skills.

Effects of short and long incubations on DNA fragmentation of testicular sperm

DNA fragmentation in testicular sperm from men with obstructive azoospermia is increased by 4-hour and 24-hour incubations and after cryopreservation with the effect is intensified by post-thaw incubation. Testicular sperm for use in intracytoplasmic sperm injection (ICSI) should be injected without delay.

Pathologic features of uterine leiomyomas following uterine artery embolization

Bilateral uterine artery embolization has recently been employed as an alternative to operational treatment of uterine leiomyomas. The pathologic features induced by uterine artery embolization have not been previously described in detail. Usually patients experience symptomatic improvement with a reduction in size of the leiomyomas. This report describes the pathologic features in a series of 10 uterine leiomyomas where tissue was available for histologic examination following uterine artery embolization. Characteristic histologic features within the leiomyomas included massive necrosis, sometimes with dystrophic calcification, vascular thrombosis, and intravascular foreign material that elicited a histiocytic and foreign-body giant cell reaction. In some cases, intravascular foreign material was present elsewhere in the myometrium, the cervix, or paraovarian region. In occasional cases, there were foci of myometrial necrosis and microabscess formation beyond the confines of the leiomyomas. Foci of extrauterine inflammation were also occasionally identified. Histopathologists should be aware of these findings because the use of uterine artery embolization will possibly become more widespread in the future.

Mitochondrial DNA deletions and nuclear DNA fragmentation in testicular and epididymal human sperm

BACKGROUND

There are still concerns about the safety of intracytoplasmic sperm injection (ICSI) due to its brief clinical record and lack of animal testing. Testicular and epididymal sperm are now used routinely for ICSI in patients with obstructive azoospermia. The use of such immature sperm compounds fears, since little is known of their mitochondrial and nuclear DNA quality.

METHODS

A modified long polymerase chain reaction (LPCR) was employed to study mitochondrial DNA (mtDNA) and a modified alkaline Comet assay to determine nuclear DNA (nDNA) fragmentation in testicular and epididymal sperm from men with obstructive azoospermia (n = 25) attending the Regional Fertility Centre.

RESULTS

Testicular sperm displayed significantly more wild-type mtDNA (45% of patients) than epididymal sperm (16% of patients). They also had a lower incidence of multiple deletions and smaller mtDNA fragments. Epididymal sperm harboured more large-scale deletions (P < 0.05). There was a strong correlation between nuclear DNA fragmentation, the number of mtDNA deletions (r = 0.48, r = 0.50, P < 0.001) and their size (r = 0.58, r = 0.60, P < 0.001) in both epididymal and testicular sperm.

CONCLUSION

This study suggests that mtDNA and nDNA of testicular sperm have fewer mutations and fragmentation than epididymal sperm and should be used in preference for ICSI in clinical treatment.