Circulating levels of free and total vascular endothelial growth factor (VEGF)-A, soluble VEGF receptors-1 and -2, and angiogenin during ovarian stimulation in non-human primates and women.

BACKGROUND: In a prospective study we measured circulating levels of vasoactive factors and their soluble receptors in women undergoing controlled ovarian stimulation (COS) for IVF who were at risk for ovarian hyperstimulation syndrome (OHSS), and compared them to those in a primate model, the rhesus monkey. METHODS: A total of 23 women were enrolled in the study and serum vascular endothelial growth factor (VEGF)-A (free and total), soluble (s)VEGF-R1 and -R2, and angiogenin levels were compared in pregnant and non-pregnant women, and in monkeys, during follicular stimulation, the luteal phase and early pregnancy. RESULTS: VEGF levels were similar during the period of follicular stimulation in pregnant and non-pregnant women, but a significant rise in both free and total VEGF occurred in pregnant women during the luteal phase (P < 0.05). The level of sVEGF-R1 (but not -R2) increased (P < 0.05) following implantation, and the rise in sVEGF-R1 corresponded to an abrupt fall in free (but not total) VEGF. In contrast, total VEGF levels remained similar to those observed on the day of hCG injection. Angiogenin levels tended to decline during follicular stimulation, then increased marginally during the luteal phase and were unchanged in early pregnancy. In contrast to women, free VEGF levels were non-detectable and total levels remained constant through the natural menstrual cycle and COS protocols in monkeys. CONCLUSIONS: The levels of circulating angiogenic factors and soluble receptors demonstrate significant changes during COS cycles and early pregnancy in women. Thus, the systemic effect of these agents is influenced by ligand-receptor protein-binding interactions, and these relationships may exhibit dynamic changes during COS cycles and early pregnancy, and could contribute to the development of OHSS.

Insulin-like growth factors-1 and -2, but not hypoxia, synergize with gonadotropin hormone to promote vascular endothelial growth factor-A secretion by monkey granulosa cells from preovulatory follicles.

The midcycle gonadotropin surge promotes vascular endothelial growth factor-A (VEGF-A) production by granulosa cells in the ovulatory follicle, but it is unclear whether primary regulators of VEGF secretion in other tissues, including hypoxia and growth factors, are also important in the ovary. To address these issues, granulosa cells were collected from rhesus monkeys during controlled ovarian stimulation either before (i.e., nonluteinized granulosa cells, NLGCs) or 27 hours after (i.e., luteinized granulosa cells, LGCs) administration of an ovulatory bolus of hCG, and cultured in fibronectin-coated wells containing a chemically defined media. When NLGCs were transferred to various O2 environments (20%, 5%, or 0% O2) or media containing 100 mM CoCl2, LH (100 ng/ml)-stimulated progesterone (P4) levels were markedly (P < 0.05) suppressed by 0% O2 or CoCl2. VEGF concentrations also declined (P < 0.05) in control, CoCl2, and CoCl2 + LH groups in 0% O2, although CoCl2 modestly increased (75% above control; P < 0.05) VEGF levels in 20% and 5% O2. When NLGCs were cultured in the presence of recombinant human insulin-like growth factor (IGF)-1, IGF-2, or insulin, there was a dose-dependent increase (P < 0.05) in VEGF levels on Day 1 of culture. Whereas optimal doses of IGF-1 or IGF-2 (50 ng/ml), hCG (100 ng/ml), and IGF plus hCG stimulated VEGF levels on Day 1, only the combination of IGF-1 or IGF-2 plus hCG increased VEGF above controls and sustained levels through Day 3 of culture. The synergistic effects of IGF and hCG were also evident in P4 levels, and were not due to changes in DNA content between treatment groups. LGCs produced much higher levels of P4 and VEGF, but the responses to different O2 concentrations and insulin-related factors were qualitatively similar to those of NLGCs. These results suggest that hypoxia is not a primary regulator of VEGF production in primate granulosa cells. However, IGFs may act in concert with the gonadotropin surge to promote VEGF secretion in the ovulatory, luteinizing follicle.

Intrauterine insemination-ready versus conventional semen cryopreservation for donor insemination: a comparison of retrospective results and a prospective, randomized trial.

OBJECTIVE: To compare fecundity rates following intrauterine insemination (IUI) with donor sperm frozen conventionally versus an IUI-ready preparation. DESIGN: Both retrospective results and a prospective, randomized study where recipients were assigned to one of two sperm cryopreservation methods in each cycle of intrauterine insemination are reported. SETTING: University-based infertility practice, affiliated private practices, and andrology laboratory. PATIENT(S): Women desiring therapeutic insemination in an effort to establish pregnancy. INTERVENTION(S): Intrauterine insemination with donor sperm frozen conventionally or by an IUI-ready protocol. MAIN OUTCOME MEASURE(S): Cycle fecundity in donor IUI recipients. RESULT(S): In a retrospective analysis involving 642 inseminations in 209 recipients, 79 pregnancies were recorded for an overall pregnancy rate of 12.3% per insemination (or cycle): 11.3% with IUI-ready sperm and 13.9% with conventionally preserved sperm. In a follow-up prospective, randomized study, the pregnancy rate for IUI-ready sperm preparations was 36% per cycle (14 of 39) whereas that for conventionally preserved sperm was 19.6% per cycle (9 of 46). Thirteen of the 23 pregnancies occurred in the first study cycle of insemination; only two pregnancies were observed in patients undergoing more than four cycles of insemination. CONCLUSION(S): Cycle fecundity for IUI-ready donor sperm is equivalent to conventional cryopreserved sperm based on both prospective and retrospective assessments.

Multiple gestations in assisted reproductive technology: can they be avoided with blastocyst transfers?

OBJECTIVE: Blastocysts are advanced-stage embryos with high implantation potential; theoretically, limited numbers of blastocysts can be used for embryo transfer to achieve good pregnancy rates with low multiple pregnancy rates. Clinical outcomes of a newly implemented blastocyst transfer program were evaluated. STUDY DESIGN: This study is a retrospective analysis of 553 blastocyst transfer cycles performed by a university-based in vitro fertilization program; risk factors associated with multiple gestations were analyzed. RESULTS: An average of 2.2 embryos were used for embryo transfer. The overall clinical pregnancy rate per embryo transfer was 45.1%; multiple gestation, twin, and triplet rates were 40.9%, 36.5%, and 4.3%, respectively. Multiple gestations increased significantly (1) when embryo transfer was done on day 5, (2) when > or =2 blastocysts were present on day 5, and (3) when maternal age was < or =30 years. CONCLUSION: In spite of a conservative approach to the number of blastocysts used for embryo transfer, the overall multiple pregnancy rate was high, and triplet pregnancies did occur.

Oocyte donor screening: the selection process and cost analysis.

OBJECTIVE: To evaluate the selection process and cost of screening oocyte donors. DESIGN: Retrospective analysis. SETTING: University-based IVF program. PATIENT(S): Potential oocyte donors. INTERVENTION(S): Outcomes of all inquiries by individuals responding to recruitment advertisements for oocyte donors over a 10-month period were assessed. Recruitment and screening costs to bring a single donor into the program were calculated. MAIN OUTCOME MEASURE(S): The attrition rate for each step of the oocyte donor screening process was determined. The costs assessed over the study period included the following: advertisement, administrative, professional, ultrasound, and blood screening. The total cost to bring a single donor into the program was calculated. RESULT(S): Advertisements led to 315 phone inquiries from potential oocyte donors. Of these, a total of 223 (71%) voluntarily withdrew from the screening process, 54 (17%) were screened out for medical or psychological reasons, and 38 (12%) entered the active donor pool. The total cost to bring a single donor into the program was approximately 1,869 dollars. CONCLUSION(S): There was significant attrition in the screening process for oocyte donation that needs to be taken into account in determining the costs of managing the program.

Using Bayes' rule to model multisensory enhancement in the superior colliculus.

The deep layers of the superior colliculus (SC) integrate multisensory inputs and initiate an orienting response toward the source of stimulation (target). Multisensory enhancement, which occurs in the deep SC, is the augmentation of a neural response to sensory input of one modality by input of another modality. Multisensory enhancement appears to underlie the behavioral observation that an animal is more likely to orient toward weak stimuli if a stimulus of one modality is paired with a stimulus of another modality. Yet not all deep SC neurons are multisensory. Those that are exhibit the property of inverse effectiveness: combinations of weaker unimodal responses produce larger amounts of enhancement. We show that these neurophysiological findings support the hypothesis that deep SC neurons use their sensory inputs to compute the probability that a target is present. We model multimodal sensory inputs to the deep SC as random variables and cast the computation function in terms of Bayes' rule. Our analysis suggests that multisensory deep SC neurons are those that combine unimodal inputs that would be more uncertain by themselves. It also suggests that inverse effectiveness results because the increase in target probability due to the integration of multisensory inputs is larger when the unimodal responses are weaker.

Development and integration of an extended embryo culture program.

OBJECTIVE: To study and evaluate a sequential, extended embryo culture system. DESIGN: Prospective study. SETTING: University-affiliated IVF clinic. PATIENT(S): All couples who were treated between October 1997 and July 1998. INTERVENTION(S): A standard human tubal fluid plus 10% serum substitute supplement (SSS) culture medium was used. The embryos were transferred to extended culture medium (S2 or G2) on day 3. MAIN OUTCOME MEASURE(S): Blastocyst formation and implantation and pregnancy rates. RESULT(S): Forty percent of the 20 donated cryopreserved embryos progressed to the blastocyst stage by day 6. Clinically, 7 (5.6%) of the 125 cycles did not result in a transfer. Blastocyst formation rates ranged from 33%-63% in the five study groups. Implantation rates ranged from 15%-52% and pregnancy rates ranged from 37%-75%. CONCLUSION(S): Extended culture to day 5 or 6 results in acceptable blastocyst formation rates, implantation rates, and pregnancy rates.

Isolated pleural effusion in severe ovarian hyperstimulation: A case report.

Assisted reproductive technology programs use controlled ovarian hyperstimulation to maximize pregnancy rates. Severe ovarian hyperstimulation syndrome is a well-known risk. Pleural effusion often accompanies severe ovarian hyperstimulation syndrome. We describe 2 cases of isolated hydrothorax without concomitant ascites and review the literature of this rare finding.

Initial experience with extended culture and blastocyst transfer of cryopreserved embryos.

OBJECTIVE: Our purpose was to evaluate the viability and transfer efficiency of cryopreserved embryos allowed to develop into blastocysts in extended culture for in vitro fertilization. STUDY DESIGN: The embryos for in vitro fertilization that had been cryopreserved at either 2 PN (pronuclear) or cleaving stage (day 1-3) were thawed and cultured for uterine transfer on day 5. Outcome for day 5 embryo transfer was prospectively compared with previous outcomes from embryos transferred on day 2 or 3. RESULTS: For embryos thawed and transferred on day 2 or 3 (n = 99), the pregnancy rate was 33%, the implantation rate per embryo transferred was 15.2%, and the rate of multiple gestations was 42.4% (14/33) with 35.7% of pregnancies having >/=3 gestational sacs. For extended culture embryos transferred on day 5 (n = 25), the pregnancy rate was 36%, the implantation rate per embryo transferred was 16.7%, and the rate of multiple gestations was 33.3% (3/9) with all of these being twins. For embryo transfers performed on day 5 in which only blastocysts were transferred (n = 9), the pregnancy rate was 66.7%, the implantation rate per blastocyst was 44.4% (greater than the rate for the day 2 or 3 embryos, P =.0043), and the rate of multiple gestations was 33.3% (2/6) with all of these being twins. In extended culture 29.8% of cryopreserved embryos progressed to the blastocyst stage. In this series 4 subjects (15.4%) did not have blastocysts by day 5. CONCLUSION: Acceptable pregnancy rates can be obtained from cryopreserved embryos cultured to the blastocyst stage with a significantly higher implantation rate. Transfer of embryos that have "self-selected" to blastocysts results in reduced risk of higher-order (>2) multiple gestations, because only 1 or 2 embryos are transferred.

Percutaneous absorption of progesterone in postmenopausal women treated with transdermal estrogen.

OBJECTIVE: The objective of this study was to evaluate the serum levels of progesterone resulting from the application of a progesterone cream to the skin. STUDY DESIGN: Six postmenopausal women were evaluated at a university clinic over a 4-week period. RESULTS: Transdermal estradiol 0.05 mg was applied 2 days before the first application of progesterone (30 mg/d) and was continued throughout the study. Patches were changed twice a week. Progesterone cream was applied once a day for 2 weeks. On day 15 and for the next 2 weeks, the progesterone cream was applied twice daily (60 mg/d). Serum 17beta-estradiol and progesterone were measured at 9 different times over a 24-hour period on day 1 and at weekly intervals for the 4-week duration of the study. Serum 17beta-estradiol concentrations varied among women, with mean concentrations of 40 to 64 pg/mL observed. Consistency in 17beta-estradiol concentrations was found within individual persons throughout the study. Serum progesterone concentrations also varied among women, with mean concentrations ranging from 1.6 to 3.3 ng/mL. After 2 weeks of percutaneous dosing, progesterone concentrations were sustained for at least 8 hours and were consistent within a given person. An appropriate increase in progesterone concentration occurred after 4 weeks compared with 2 weeks of application. Individually, a 0.53 correlation, significant at P <.0001, was seen between the absorption of 17beta-estradiol and progesterone. CONCLUSION: Significant increases in serum concentrations of progesterone were observed in all of the women studied. The percutaneous absorption of progesterone correlates strongly with the absorption of transdermal 17beta-estradiol. There is variance in absorption of progesterone just as with 17beta-estradiol, and the 2 measures are closely correlated. The percutaneous application of progesterone cream appears to be a safe and effective route of administration.

Fecundability trends among sperm donors as a measure of donor performance.

OBJECTIVE: To examine fecundability trends among sperm donors. DESIGN: Retrospective analysis. SETTING: University-based sperm bank and donor insemination program. PATIENT(S): Sperm donors and recipients. INTERVENTION(S): A group of recipients underwent IUI with cryopreserved donor sperm. Fecundability was calculated for 20 sperm donors over 800 insemination cycles. MAIN OUTCOME MEASURE(S): Average fecundability per donor was compared for the first 40 cycles of a donor's use and for those donors within a group of more fertile recipients. Sperm parameters, recipient ages, and number of unique recipients for each donor were analyzed. RESULT(S): Average donor fecundability is constant; however, individual donors demonstrated differences among their fecundabilities (overall mean, 0.09; range, 0.01-0.26). These differences persisted for donors among a group of more fertile recipients (overall mean, 0.12; range, 0.02-0.35). A donor's fecundability at 15 cycles is predictive of his future performance. CONCLUSION(S): Differences in fecundability exist among sperm donors which cannot be discerned through routine semen parameters. Sperm donor fecundability should be analyzed periodically, and directors of sperm banks should consider discontinuing use of a donor whose outcome is substandard.

Human chorionic gonadotropin production by the pituitary gland in a premenopausal woman.

OBJECTIVE: Our purpose was to investigate the source of human chorionic gonadotropin production in a nonpregnant, premenopausal woman. STUDY DESIGN: A case of human chorionic gonadotropin production by the pituitary gland in a premenopausal woman is described. RESULTS: Our results confirm that a biologically active human chorionic gonadotropin-like molecule was secreted in a nonpregnant woman. CONCLUSIONS: Our results indicate that the pituitary gland was the most likely source of human chorionic gonadotropin production.

Differential effects of subcutaneous estrogen and progesterone on low-density lipoprotein size and susceptibility to oxidation in postmenopausal rhesus monkeys.

OBJECTIVE: To study the differential effects of subcutaneous E2 alone or in combination with P on the susceptibility of low-density lipoprotein (LDL) cholesterol to oxidation in naturally postmenopausal diet-controlled rhesus monkeys. DESIGN: Prospective, longitudinal controlled study. SETTING: Oregon Health Sciences University, Portland, Oregon, and Oregon Regional Primate Research Center, Beaverton, Oregon. PATIENT(S): Five naturally postmenopausal rhesus monkeys. INTERVENTION(S): Estradiol was administered subcutaneously for the first 4 weeks, followed by E2 plus P for 4 weeks, followed by a third 4-week washout period. MAIN OUTCOME MEASURE(S): Changes in plasma lipoprotein levels and oxidation of LDL and serum concentrations of E2 and P. RESULT(S): Levels of LDL cholesterol fell after 4 weeks of treatment with E2, compared with baseline. The lag time to half maximal light absorbancy after 4 weeks of E2 treatment was significantly increased compared with baseline. The maximal absorbance values and the slope of the propagation phase after 4 weeks of treatment with E2 were decreased compared with baseline. After 4 weeks of combined E2 and P treatment, all values were comparable to baseline. CONCLUSION(S): These results suggest that subcutaneous E2 therapy appears to enhance LDL resistance to oxidation and that this effect is attenuated by the addition of the P.

Vascular endothelial growth factor levels in serum and follicular fluid of patients undergoing in vitro fertilization.

OBJECTIVE: To define the relationship between serum and follicular fluid (FF) levels of vascular endothelial growth factor (VEGF), E2, and P in patients undergoing IVF; to quantify the effects of hCG on serum levels of VEGF during early pregnancy, and to report serial measurements of serum and ascites fluid levels of VEGF in a patient with severe ovarian hyperstimulation syndrome (OHSS). DESIGN: Prospective observational study. SETTING: University IVF program. PATIENTS(S): Women undergoing conventional IVF, receiving donated oocytes or spontaneously conceiving. One patient hospitalized with severe OHSS. MAIN OUTCOME MEASURE(S): Concentrations of VEGF, E2, and P in serum, FF, or peritoneal fluid. RESULT(S): At the time of egg retrieval, FF VEGF concentrations were positively correlated with serum and FF P concentrations and with patient age. At 11 to 14 days after ET, pregnant recipients of autologous fresh embryos had higher serum VEGF levels than both nonpregnant recipients of autologous fresh embryos and pregnant recipients of donor eggs. Elevated serum VEGF levels in a patient with severe OHSS coincided with the clinical onset and recurrence of symptoms. CONCLUSION(S): In patients undergoing IVF, FF VEGF levels at the time of egg retrieval correlated with the degree of follicular luteinization. There is a significant ovarian contribution to circulating VEGF levels during early gestation. Elevated serum VEGF levels may be a factor in the etiology of OHSS symptoms.

Alteration of ascending thoracic aorta compliance after treatment with menotropin.

OBJECTIVE: Our purpose was to determine whether aortic size and compliance are altered by an exogenously induced rise in estrogen. STUDY DESIGN: Magnetic resonance imaging was used to determine the aortic cross-sectional area/aortic pressure relationship in nine premenopausal women before and after menotropin therapy. Simultaneous electrocardiograms, carotid pulse tracings, phonocardiograms, and brachial artery pressures were obtained before each magnetic resonance imaging acquisition. Ascending thoracic aorta cross-sectional area was obtained every 32 msec and aligned with brachial artery pressures extrapolated from the carotid pulse tracing, allowing construction of the ascending thoracic aorta cross-sectional area/aortic pressure relationships. Aortic cross-sectional area was normalized to body surface area, and the shifts in the position for the ascending thoracic aorta cross-sectional area/aortic pressure relationship were determined with use of analysis of covariance. RESULTS: Heart rate and aortic pressure were unchanged before and after menotropin treatment. Initial estradiol levels were < 20 pg/ml. After menotropin treatment (7.4 +/- 1.0 days) estradiol levels rose to 905 +/- 371 pg/ml (p < 0.0001). Ascending thoracic aorta cross-sectional area/body surface area was not significantly increased, adjusted y mean of 389 +/- 7 mm2/m2 before and 403 +/- 7 mm2/m2 after menotropin treatment (p < 0.24). The slope of the ascending aorta cross-sectional area/aortic pressure relationship, an index of aortic compliance, increased from 1.4 +/- 0.6 mm2/m2/mm Hg before to 1.7 +/- 0.6 mm2/m2/mm Hg after menotropin treatment (p < 0.001). CONCLUSION: In premenopausal women a short-term rise in estrogen induced by menotropin treatment is associated with an increase in aortic compliance. Aorta size is not significantly increased within this time frame.

Vascular endothelial growth factor production by human luteinized granulosa cells in vitro.

Vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) originating from the follicle or corpus luteum may be a physiological regulator of ovulation and neovascularization of luteinizing tissue, as well as a pathological factor in the development of ovarian hyperstimulation syndrome (OHSS). The objective of this study was to quantify VEGF production by human luteinized granulosa cells in vitro and to determine if gonadotrophin stimulates VEGF production directly and/or indirectly via enhanced synthesis of progesterone. In study 1, luteinized granulosa cells collected from women undergoing ovarian stimulation for in-vitro fertilization were cultured in the presence and absence of human chorionic gonadotrophin (HCG; 100 ng/ml) and/or low density lipoprotein (LDL; 100 microg protein/ml). In study 2, the progesterone synthesis inhibitor trilostane (250 ng/ml) and/or a progesterone receptor antagonist ZK137.316 (3.2 microM) were also added. Medium was harvested on days 1, 3, 5, 7 and 9 of culture and assayed for VEGF and progesterone. Results of study 1 were divided into two categories based on control concentrations of VEGF on day 1: 'low producers' (n = 6; <750 pg VEGF/ml) and 'high producers' (n = 5; >1000 pg VEGF/ml; P < 0.01). VEGF concentrations in cultures of both low and high producers increased (P < 0.01) from day 1 to maximal values on day 3, then steadily declined through to day 9. Chronic exposure to LDL or HCG increased (P < 0.05) VEGF concentrations in cultures of low producers by day 3 and day 5 respectively. In contrast, LDL did not alter VEGF concentrations in cultures of high producers and HCG did not increase VEGF concentrations until day 7. Nevertheless, acute exposure to HCG beginning on day 7 increased (P < 0.05) VEGF concentrations 3-fold in cultures of low or high producers. In study 2, trilostane treatment decreased (P < 0.05) progesterone concentrations by 91% on day 1 of culture but had no effect on VEGF concentrations on any day. ZK137.316 alone or with trilostane did not affect VEGF synthesis. These results suggest that VEGF production by luteinized granulosa cells is enhanced by gonadotrophin (HCG) independent of gonadotrophin-stimulated progesterone synthesis. These data are consistent with the hypothesis that the exacerbation of OHSS in early pregnancy is mediated by the CG stimulation of luteal VEGF production.

Connection matrix of the hippocampal formation: I. The dentate gyrus.

The hippocampal formation presents a special opportunity for realistic neural modeling since its structure, connectivity, and physiology are better understood than that of other cortical components. A review of the quantitative neuroanatomy of the rodent dentate gyrus (DG) is presented in the context of the development of a computational model of its connectivity. The DG is a three-layered folded sheet of neural tissue. This sheet is represented as a rectangle, having a surface area of 37 mm2 and a septotemporal length of 12 mm. Points, representing cell somata, are distributed in the model rectangle in a roughly uniform fashion. Synaptic connectivity is generated by assigning each presynaptic cell a spatial zone representing its axonal arbor. For each postsynaptic cell, a list of potential presynaptic cells is compiled, based on which arbor zones the given postsynaptic cell falls within. An appropriate number of presynaptic inputs are then selected at random. The principal cells of the DG, the granule cells, are represented in the model, as are non-principal cells, including basket cells, chandelier cells, mossy cells, and GABAergic peptidergic polymorphic (GPP) cells. The neurons of layer II of the entorhinal cortex are included also. The DG receives its main extrinsic input from these cells via the perforant path. The basket cells, chandelier cells, and GPP cells receive perforant path and granule cell input and exert both feedforward and feedback inhibition onto the granule cells. Mossy cells receive converging input from granule cells and send their output back primarily to distant septotemporal levels, where they contact both granule cells and non-principal cells. To permit numerical simulations, the model must be scaled down while preserving its anatomical structure. A variety of methods for doing this exist. Hippocampal allometry provides valuable clues in this regard.

Anatomic uterine defects.

Congenital or acquired uterine defects remain important considerations in the investigation of recurrent pregnancy loss. When repeated first or second trimester losses, preterm delivery, or abnormal fetal presentations are documented, the suspicion of a structural uterine abnormality should be high. The diagnosis of uterine defects is no longer elusive. The combination of radiologic imaging techniques, hysteroscopy, and laparoscopy enables an accurate diagnosis in nearly every case. The optimal treatment for uterine malformations is still a matter of considerable controversy. Therefore, when a uterine defect is diagnosed, tough clinical decisions must be made. When alternate causes of pregnancy loss are excluded, pregnancy potential will depend primarily on the specific type of uterine anomaly that is detected. It is important to recognize that not all uterine defects are amenable to therapy, but in carefully selected patients, reparative surgery may be rewarding.

A review of cytological specimens from horses with and without clinical signs of respiratory disease.

Thirty-six transtracheal washing (TTW) and 12 bronchoalveolar lavage (BAL) specimens collected in clinical practice from horses with and without respiratory disease were reviewed. Cytological features were considered in accordance with the presenting complaint, clinical signs, clinical diagnoses, microbiological, radiographic and/or endoscopic findings, therapy, and response to therapy. The trichrome-stained TTW and BAL specimens were useful in interpreting the results of concurrent microbiological cultures, and determining whether a condition was present based on occurrence of typical cytological features of patterns (e.g. probable allergy, chronic obstruction, uncomplicated exercise-induced pulmonary haemorrhage), determining pathological/anatomical diagnoses (e.g. bronchitis, bronchiolitis and/or alveolitis; presence of metaplasia or dysplasia) and possible aetiologies (e.g. allergy, bacterial infection). Review of these cases confirmed the practicality of using cytological specimens to evaluate the equine respiratory tract; there were few unsatisfactory specimens and no reported complications. The importance of cytological evaluation of the equine respiratory system was emphasised by the identification of 13 cases in which clinical signs were not apparent at physical examination. Sequential collections of cytological specimens from foals, young horses before and during early training, and mature horses in training may provide more information about the response of the equine lung to stresses associated with training and/or common environmental exposures.

Difficult embryo transfer managed with a coaxial catheter system.

Our objective was the design of a catheter system that could be used in cases of a failed trial transfer. The system uses semirigid and soft-tipped materials that should allow atraumatic and reliable endometrial placement of embryos in difficult cases.