Clinical, ultrasonographic and pathological findings in a bull with segmental aplasia of the mesonephric duct

On assessment for use in an AI stud, a 12-month-old bull was found to produce low volume ejaculates with 41% of the sperm having morphological abnormalities. No left epididymal tail was palpable and the head of the epididymis on the left was twice the size compared with the right. Ultrasound examination showed the left testis to contain a large central area of decreased echogenicity, which could be followed proximally to a 15-mm echolucent lesion at the site of the epididymal head. Postmortem examination revealed a 15-mm diameter cyst in the region of the left epididymal head, and absence of the body and tail of the epididymis. The mediastinum testis of the left testis was dilated, corresponding to the area of decreased echogenicity observed on ultrasonography. No left seminal vesicle was present and the ampulla was significantly smaller than the same structure on the right. Histological examination revealed incomplete or absent spermatogenesis involving the majority of seminiferous tubules in the left testis, and a small proportion of those of the right testis. The cystic structure at the site of the left epididymal head was lined by irregular, sometimes attenuated, epithelium and contained sparse spermatozoa. This case demonstrates the adverse impact, which segmental aplasia of the mesonephric duct had on the testicular and epididymal function of a bull, and highlights the importance of careful clinical assessment in its diagnosis.

Diamond at 800 GPa

A new compression technique, which enables the study of solids into the TPa regime, is described and used to ramp (or quasi-isentropically) compress diamond to a peak pressure of 1400 GPa. Diamond stress versus density data are reported to 800 GPa and suggest that the diamond phase is stable and has significant material strength up to at least this stress level. Data presented here are the highest ramp compression pressures by more than a factor of 5 and the highest-pressure solid equation-of-state data ever reported.

The effect of a chronic stressor, lameness, on detailed sexual behaviour and hormonal profiles in milk and plasma of dairy cattle

The objectives of the present study were to quantify the effects of a biological chronic stressor (lameness) on the duration and frequency of different oestrous behaviours in parallel with milk hormone profiles. Dairy cows 51.8 +/- 1.4 days postpartum (n = 59), including 18 non-lame control cows, were scored for lameness and closely observed for signs of oestrus having had their follicular phases synchronized by administration of gonadotrophin-releasing-hormone (GnRH) followed by prostaglandin F(2alpha) (PG) 7 days later. Lameness shortened the period when herd-mates attempted to mount the lame cows (1.83 +/- 0.69 h vs 5.20 +/- 1.53 h; p = 0.042) but did not affect the overall duration of total behaviours (lame 12.3 +/- 1.3 h vs non-lame 15.2 +/- 1.3 h). Lameness also lowered the intensity of oestrus [1417 +/- 206 points (n = 18) vs 2260 +/- 307 points (n = 15); p = 0.029]. Throughout the synchronized oestrous period, lame cows mounted the rear of herd-mates less frequently (p = 0.020) and tended to chin rest less (p = 0.075). Around the period of maximum oestrous intensity, lameness also diminished the proportion of cows mounting the rear of another cow and chin resting (p = 0.048, p = 0.037, respectively). Furthermore, lame cows had lower progesterone values during the 6 days before oestrous (p < or = 0.05). Fewer lame cows were observed in oestrus following PG (non-lame 83%, lame 53%; p = 0.030); however, if prior progesterone concentrations were elevated, lame cows were just as likely to be observed in oestrus. In conclusion, following endogenous progesterone exposure, lameness shortens the period when herd-mates attempt to mount lame cows but does not affect the incidence of oestrous. However, lame cows are mounted less frequently and express oestrus of lower intensity. This is associated with lower progesterone prior to oestrus but not with abnormal oestradiol or cortisol profiles in daily milk samples.

Mucin immunohistochemistry in the diagnosis and mapping of extramammary Paget's disease

Extramammary Paget's disease (EMPD) is a rare skin cancer of the genital region in which cancer cells with enlarged nuclei and pale cytoplasm are scattered singly in the affected epidermis. These cancer cells, called Paget cells, contain mucin, which is never found in normal epidermis. The oligosaccharide side chains of Paget cell mucin end with sialic acid. Sialic acid is easily detected by zirconyl haematoxylin or alcian blue. The other sugars in the oligosaccharide chains can be detected by the periodic acid-Shiff reaction. Rarely, the diagnosis of EMPD is complicated by the absence of mucin from the Paget cells. We have examined such an atypical case. The oligosaccharide side chains, including the sialic acids, are absent. In both this case and a typical case, the Paget cells contain epithelial membrane antigen mucin (MUC1) core protein and usually contain gastric surface-type mucin (MUC5AC) core protein, which can be stained by antibodies. Since neither core protein is found in normal epidermis, epithelial membrane antigen core protein may be the most reliable diagnostic marker for extramammary Paget's disease. In both the atypical case and the typical case of Paget's disease, some cells that look like keratinocytes contain mucin core proteins. These may be incipient Paget cells. We suggest that using th epithelial membrane antigen core protein as a marker for the true extent of extramammary Paget's disease could facilitate complete excision and reduce the rate of recurrence.

Ultrafast dynamic compression technique to study the kinetics of phase transformations in bismuth

Preheated Bi (296-532 K) was ramp compressed with 15-35 ns rise times to a peak stress of approximately 11 GPa to explore structural phase-transformation kinetics under dynamic loading conditions. At high strain rates, epsilon[over ]>5 x 10;{6} s;{-1}, deviation from equilibrium phase boundaries suggests that compression time scales are comparable to the new phase incubation period. The dependence of DeltaP/kT on epsilon[over ] is consistent with a thermally activated transformation.

Chronic stress, hormone profiles and estrus intensity in dairy cattle

The objectives of the present study were to determine if lameness, a model for a natural chronic stressor, affects hormone concentrations in milk prior to estrus and/or the subsequent expression of estrus in the postpartum period. Dairy cows>20 days postpartum were scored for lameness and observed for estrus intensity using a weighted scoring system (>100 points=estrus=Day 0). Increasing lameness score was not associated with daily profiles of milk progesterone (throughout Days -18 to 0), estradiol (Days -6 to 2) or cortisol (Days -18 to 2) around estrus, maximum estradiol values or estradiol concentrations on Day 0. However, post hoc pair wise comparisons revealed that prior to estrus, severely lame cows had lower maximum progesterone concentrations compared to nonlame cows (1.3+/-0.1, 1.2+/-0.2, 0.7+/-0.1 ng/ml milk; P=0.042). Furthermore, severely lame cows expressed behavioral estrus with lower intensity (284+/-128 points, n=9) compared to moderately lame (662+/-310 points, n=9) or nonlame animals (583+/-275 points, n=18; P=0.05 and P=0.02, respectively). Resting concentrations of cortisol (Days 20-80 postpartum) did not vary between days postpartum or lameness score. The incidence of behavioral estrus was not affected by increasing lameness score, as 54.2%, 56.2% and 50.0% periods with low progesterone were associated with spontaneous estrus expression, respectively. Concluding, in this biological model of chronic stress, lameness did not affect the incidence of behavioral estrus but did reduce estrus intensity once ovarian cyclicity had resumed after calving. This reduced intensity of estrus was associated with lower maximum progesterone values prior to estrus but not abnormal daily cortisol or estradiol values in milk.

?-Amino Butyric Acid Control of Arginine Vasopressin Release from the Ewe Hypothalamus In Vitro: Sensitivity to Oestradiol

The present study aims to ascertain the influence of gamma-amino butyric acid (GABA)(A or B) receptors on arginine vasopressin (AVP) release in vitro and determine whether E(2) modulates GABA-AVP interaction. Within 10 min of ewe killing, saggital midline hypothalamic slices (from the anterior preoptic area to the mediobasal hypothalamus along with the median eminence, 2-mm thick, two per ewe) were dissected, placed in oxygenated minimum essential media (MEM)-alpha at 4 degrees C and within 2 h were singly perifused at 37 degrees C with oxygenated MEM-alpha (pH 7.4; flow rate 0.15 ml/min), either with or without E(2) (24 pg/ml). After 4-h equilibration, 10-min fractions were collected for 4 h interposed with a 10-min exposure at 60 min to a specific GABA(A or B) receptor agonist or antagonist at various doses (0.1-10 mm). GABA(A) (muscimol; no E(2), n = 7 perifusion chambers, with E(2), n = 11) or GABA(B) (baclofen; no E(2), n = 8, with E(2), n = 15) agonists (10 mm) did not influence AVP concentrations. However, AVP release increased (p < 0.05) 20-30 min after exposure to 10 mm GABA(A or B) antagonists (bicuculline, no E(2), n = 7: from 4.6 +/- 0.7 to 33.0 +/- 0.4, with E(2), n = 17: from 11.9 +/- 1.4 to 32.8 +/- 6.0; CGP52432, with E(2), n = 14: from 14.0 +/- 2.6 to 28.8 +/- 3.9 pg/ml). At the end of the collection period, hypothalamic slices responded to KCl (100 mm) with AVP efflux (p < 0.05). GABA(B) but not GABA(A) antagonist-stimulated AVP release was enhanced in the presence of E(2). In summary, AVP release is under the inhibitory influence of GABA input with further potentiation by E(2) through GABA(B) receptors in vitro.

Neospora caninum in cattle: experimental infection with oocysts can result in exogenous transplacental infection, but not endogenous transplacental infection in the subsequent pregnancy

Whilst it is presumed that infection of pregnant cattle with Neospora caninum oocysts can provoke abortion and is the likely cause of epidemic abortion outbreaks, only two previous experiments have involved inoculation of pregnant cows with oocysts (and only one abortion was provoked in 22 pregnancies). Here, we describe the oral oocyst challenge of 18 cows synchronously bred and inoculated precisely at 70 (n=6), 120 (n=6) and 210 (n=6) days in pregnancy with a nominal dose of 40,000 oocysts. Only one abortion occurred (at the 120 days challenge) which could be definitively ascribed to N. caninum and no transplacental infection (TPI) was detected in any of the other 11 calves born in the 70 and 120 day challenge groups. In contrast, 4/5 live calves born to cattle challenged at 210 days were transplacentally infected. When cows which had transplacentally infected their calves in the first pregnancy were rebred, no TPI occurred. The results show that the timing of challenge influences clinical and parasitological outcomes and that cattle in late pregnancy are exquisitely sensitive to oocyst challenge leading to exogenous TPI and congenitally infected calves. However, cattle which were indisputably systemically infected in their first pregnancy did not induce endogenous TPI in their subsequent pregnancy. This confirms previous results with experimental tachyzoite challenge and suggests that post-natal infection does not lead to persisting infections which can recrudesce in pregnancy.

Peripheral immune responses in pregnant cattle following Neospora caninum infection

Experimental infection of cattle with Neospora caninum in early gestation causes foetal death, but the foetus survives infection in late gestation. An immunological mechanism of abortion has been suggested; therefore changes in the maternal immune response during pregnancy could account for these differences. We have investigated the peripheral immune responses of pregnant cattle following an intravenous inoculation with 10(7) N. caninum tachyzoites in early and late gestation. Percentages of CD2+ and CD4+ T-cells in peripheral blood mononuclear cells (PBMC) increased 1-2 weeks after infection in both early (day 70) and late (day 210) gestation, and percentages of CD8+ T-cells increased 1-2 weeks after infection at day 70. Interleukin-4 (IL-4) and interferon-gamma (IFN-gamma) mRNA expression in PBMC increased 1-2 weeks after infection at day 210 and IL-4 increased 1-2 weeks after infection at day 70. Immunomagnetic isolation of CD4+ cells from PBMC showed that they were a major source of IL-4 and IFN-gamma, and expression of both cytokines increased in CD4+ cells after infection in early and late gestation. These results suggest that CD4+ cells proliferate and express IL-4 and IFN-gamma in response to N. caninum irrespective of the stage of gestation when infection occurs.

Evidence for elevated nicotine-induced structural plasticity in nucleus accumbens of adolescent rats

Male Long-Evans rats were administered nicotine bitartrate or sodium tartrate either during adolescence (p29-43) or adulthood (p80-94). Route of administration was via subcutaneously implanted osmotic pump (initial dose 2.0 mg/kg/day, free base). Five weeks following nicotine administration, brains were processed for Golgi-Cox staining. Medium spiny neurons from nucleus accumbens (NAc) shell were digitally reconstructed for morphometric analysis. Total dendritic length and branch number were greater in medium spiny neurons from animals pretreated with nicotine during adolescence. A branch order analysis indicated that increased branch number was specific to higher order branches. Mean branch lengths did not differ with respect to treatment as a function of branch order. Thus, nicotine-induced increases in total dendritic length were a function of greater numbers of branches, not increased segment length. In contrast, adult nicotine exposure did not significantly alter total dendritic length or branch number of medium spiny neurons. Total dendritic length and branch number of a second morphological type, the large aspiny neuron, did not differ following either adolescent or adult pretreatment. The age-dependent alteration of accumbal structure was associated with qualitatively different behavioral responses to drug challenge. These data provide evidence that drug-induced structural plasticity in nucleus accumbens is considerably more pronounced during adolescence.

Efficacy of Germination Stimulants of Sclerotia of Sclerotium cepivorum for Management of White Rot of Garlic

The ability of soil-applied garlic powder and diallyl disulfide to stimulate germination of sclerotia of Sclerotium cepivorum, the cause of white rot of onion and garlic, was evaluated in four field trials. Because sclerotia germinate in response to exudation of specific volatile sulfides and thiols from allium roots, sulfides applied to the ground in the absence of an allium crop cause death of the sclerotia after they germinate and exhaust nutrient reserves. In this study, garlic powder and a synthetic garlic oil, diallyl disulfide, were incorporated into the soil in commercial fields naturally infested with S. cepivorum. Methyl bromide was included as a chemical control. Within 3 months after treatment, over 90% of the sclerotia died in the plots treated with the germinationstimulants, which was similar to the reduction of viable sclerotia achieved with an application of methyl bromide. The degree of sclerotial mortality in plots treated with garlic powder at 112 kg/ha or more was almost equal to that achieved by diallyl disulfide at 0.5 ml/m² or methyl bromide at 448 kg/ha. Despite the efficacy of the stimulants and methyl bromide to reduce populations of sclerotia, the pathogen caused substantial root rot and yield losses in subsequent garlic crops planted about a year after soil treatment. However, germination stimulants have utility because the reduction of the vast majority of sclerotia in a field reduces the risk of spread of the pathogen to neighboring fields.

Immunization of cattle with live tachyzoites of Neospora caninum confers protection against fetal death

Neospora caninum is an obligate intracellular protozoan parasite that causes abortion in cattle. It is normally found as a latent infection controlled by a T-helper-cell type 1 response involving CD4(+) cytotoxic T cells and gamma interferon. Cattle may be infected by two different routes: transplacentally as a result of activation of the latent infection in the mother causing congenital infection or abortion and by ingestion of oocysts, which, if it occurs during gestation, can also result in abortion. Here, for the first time, we establish proof that live vaccination protects against fetal death, whereas immunization using whole-tachyzoite lysate in different adjuvants fails to protect against fetal death. Strong antibody responses were induced in all the vaccinated groups, and the quality and magnitude of these responses were similar in the live- and the lysate-vaccinated groups. In contrast, only the group immunized with live tachyzoites had strong cellular and gamma interferon responses prior to challenge, and these responses correlated with protection against fetopathy. These results suggest that a cellular immune response may be important in the mechanisms involved in protection against N. caninum-associated abortions.

Oestradiol Stimulates the Release of AVP and GnRH from the Ewe Hypothalamus In Vitro

Oestradiol (E(2)) sensitizes the stress and reproductive axes in vivo. Our current aim is to investigate whether E(2) directly influences hypothalamic AVP and GnRH release in vitro. Within 10 min of ewe killing, saggital midline hypothalamic slices (from the anterior preoptic area to mediobasal hypothalamus, 2 mm thick, two per sheep) were dissected, placed in oxygenated MEM-alpha at 4 degrees C and within next 2 h were singly perifused at 37 degrees C with oxygenated MEM-alpha (pH 7.4; flow rate 150 microl/min) alone (vehicle; n = 15), with low (6 pg/ml; n = 14) or high E(2) (24 pg/ml; n = 13). After 5 h equilibration, 10 min fractions were collected for 3 h with exposure to 100 mm KCl for 10 min within the last hour. Concentrations of AVP and GnRH were measured by RIA. Baselines for AVP and GnRH were 7.0 +/- 1.1 and 17.4 +/- 0.8 pg/ml respectively. Basal values with low E(2) were similar to vehicle for AVP (7.5 +/- 1.2 pg/ml) and GnRH (17.5 +/- 1.1 pg/ml). However, high E(2) increased basal AVP (11.7 +/- 1.4 pg/ml; p < 0.05) and GnRH (23.7 +/- 1.4 pg/ml; p < 0.05). After KCl, AVP and GnRH respectively, increased (p < 0.05) to 25.6 +/- 7.5 and 38.2 +/- 5.6 (vehicle), 26.3 +/- 7.5 and 23.6 +/- 2.1 (low E(2)) and 24.1 +/- 5.4 and 41.3 +/- 6.6 pg/ml (high E(2)). After KCl, maximum values of AVP occurred at 20 and GnRH at 30 min. In conclusion, high E(2) concentration augments AVP and GnRH release by direct action on the ewe hypothalamus.

Multidimensional scaling of ferrous sulfate and basic tastes

The status of metallic sensations as a primary or basic taste category is controversial. Ferrous sulfate (FeSO4) has been suggested as a prototypical metallic chemosensory stimulus. At least part of the metallic sensation from FeSO4 arises from a metallic retronasal smell. The quality of this sensation was studied via multidimensional scaling (MDS) of taste similarities, with and without nasal closure to eliminate retronasal olfactory sensations. The metallic stimulus was embedded in a series containing classical "basic taste" stimuli, alum and monosodium glutamate. With olfaction available, the metallic stimulus plotted away from basic tastes and taste mixtures. Scaled ratings of sensory properties related to metallic taste (iron-nail, copper-penny-like, aftertaste) of FeSO4 decreased with nasal closure. Results are consistent with the idea that ferrous sulfate produces a distinctly different sensation from the traditional basic tastes, which includes both olfactory and oral sensations.

The usefulness of a single measurement of insulin-like growth factor-1 as a predictor of embryo yield and pregnancy rates in a bovine MOET program

The objective was to determine if a single measurement of plasma insulin-like growth factor-1 (IGF-1) could predict the number of viable embryos obtained from donors and the likelihood of pregnancy in recipients in multiple ovulation and embryo transfer (MOET) programs in cattle. The embryo yields from 101 embryo recoveries were examined in maiden Holstein heifers (n=75) and multiparous Holstein cows (lactating cows n=20, dry cows n=6). Donors were super stimulated with FSH and embryo recovery was done non-surgically 7 days after artificial insemination. Embryos were classified according to the IETS criteria. Pregnancy rates in 100 maiden Holstein heifer recipients were analysed. Recipients were on day 7+/-1 of the estrous cycle at transfer. Pregnancy diagnosis was carried out at day 30 (PD 30) and rechecked at day 60 (PD 60) after transfer. Blood samples from coccygeal vessels taken at the time of embryo recovery (donors) and transfer (recipients) were analysed for IGF-1, insulin, beta-hydroxybutyrate (beta-OHB), non-esterified fatty acids (NEFA), urea and cholesterol. There was a negative correlation between the number of viable embryos and insulin (r=-0.33, P=0.025) in donor heifers. In donor cows, the number of viable embryos was correlated with IGF-1 (r=0.43, P=0.028) and cholesterol (r=-0.43, P=0.027). In recipients, PD30 and PD 60 were not affected by any of the circulating parameters analysed. Insulin, IGF-1 and cholesterol only explained 8.9, 13.9 and 15.8% of the variation in the production of viable embryos, respectively. Several factors affect MOET programs and under the circumstances of the present study the usefulness of hormonal and metabolic profiles as predictors of the outcome of this biotechnology was limited.

Plasma conditions for improved energy coupling into the gain region of the Ni-like Pd transient collisional x-ray laser

We have directly probed the conditions in which the Ni-like Pd transient collisional x-ray laser is generated and propagates by measuring the near-field image and by utilizing picosecond resolution soft x-ray laser interferometry of the preformed Pd plasma gain medium. The electron density and gain region of the plasma have been determined experimentally and are found to be in good agreement with simulations. We observe a strong dependence of the laser pump-gain medium coupling on the laser pump parameters. The most efficient coupling occurs with the formation of lower density gradients in the preformed plasma and when the duration of the main heating pulse is comparable to the gain lifetime (approximately 10 ps for mid- Z Ni-like schemes). This increases the output intensity by more than an order of magnitude relative to the commonly utilized case where the same pumping energy is delivered within a shorter heating pulse duration (<3 ps) . In contrast, the higher intensity heating pulses are observed to be absorbed at higher electron densities and in regions where steep density gradients limit the effective length of the gain medium.

High-repetition-rate grazing-incidence pumped x-ray laser operating at 18.9 nm

We have demonstrated a 10 Hz Ni-like Mo x-ray laser operating at 18.9 nm with 150 mJ total pump energy by employing a novel pumping scheme. The grazing-incidence scheme is described, where a picosecond pulse is incident at a grazing angle to a Mo plasma column produced by a slab target irradiated by a 200 ps laser pulse. This scheme uses refraction of the short pulse at a predetermined electron density to increase absorption to pump a specific gain region. The higher coupling efficiency inherent to this scheme allows a reduction in the pump energy where 70 mJ long pulse energy and 80 mJ short pulse energy are sufficient to produce lasing at a 10 Hz repetition rate. Under these conditions and by optimizing the delay between the pulses, we achieve strong amplification and close to saturation for 4 mm long targets.

Observation of a multiply ionized plasma with index of refraction greater than one

We present clear experimental evidence showing that the contribution of bound electrons can dominate the index of refraction of laser-created plasmas at soft x-ray wavelengths. We report anomalous fringe shifts in soft x-ray laser interferograms of Al laser-created plasmas. The comparison of measured and simulated interferograms shows that this results from the dominant contribution of low charge ions to the index of refraction. This usually neglected bound electron contribution can affect the propagation of soft x-ray radiation in plasmas and the interferometric diagnostics of plasmas for many elements.

Heterogeneity in proliferative potential of ovine mesenchymal stem cell colonies

Bone marrow biopsies were taken from the iliac crest of 28 individual sheep from three different breeds, ranging in age from 4 months to 8 years and mesenchymal stem cells (MSCs) isolated using selection due to plastic adherence. Cells were cultured in medium that had been selected for its effect on observed MSC proliferation, until populations of greater than 50 million had been obtained from each biopsy. The identity of the isolated cell populations as progenitors of the mesenchymal lineage was verified by deriving both osteoblastic and chondrocytic phenotypes when cultured in osteogenic and chondrogenic medium supplements, respectively. The rate of cell proliferation for each marrow biopsy was measured at each passage and the number of initial stem cells in each sample estimated. There was no statistically significant correlation between the age of the sheep and MSC proliferative potential, or age and estimated initial MSC number. There was no apparent significant difference between proliferation rate and sheep breed and colonies established from frozen cells grew at similar rates to pre-frozen cells. Counter intuitively, there appeared to be a negatively correlated trend between proliferation rate and MSC concentration in the samples. It is concluded that no initial descriptive statistics of the marrow biopsies can assist in estimating the proliferative potential, and therefore the timing of future surgeries, of MSCs sampled for the purposes of tissue engineering.

Metabolic and histological analysis of mesenchymal stem cells grown in 3-D hyaluronan-based scaffolds

Sheep mesenchymal stem cells (MSCs) were isolated and expanded using the principle of plastic adherence. Their identity as progenitor cells was confirmed by induction along the osteoblastic lineage using osteogenic supplements and observation of calcific deposits by von Kossa staining. MSCs were seeded onto two types of hyaluronan-based cylindrical scaffolds in high concentrations and cultured for varying time points up to three weeks. Culture medium was supplied using the following conditions: statically, on a shaker, by stirring with a magnetic stirrer or by perfusion in a tubular flow circuit. Total cell metabolism was assessed by MTT assay and the quality of cell coverage and matrix formation observed by SEM and histological analysis of thin sections of the constructs. Perfusion culture was established as the most appropriate culturing conditions, with cell metabolism increasing by approximately 300% over three weeks. The coverage of the scaffold surface was very good and the deposition of collagenous matrix was superior in these conditions compared to the, static and other dynamic culture conditions.