Plasma cortisol concentrations after CIDR insertion in beef cows.

The objective of this study was to show plasma cortisol concentration after treatment with controlled internal drug release (CIDR) in non-suckling beef cows. On day 9 after oestrus, two cows were inserted with CIDR into the vagina for 24 h and the other two cows were treated as a control group. Four days later, the two control cows were treated with CIDR and the other two CIDR-treated cows were used as controls. Cortisol concentrations were determined by ELISA in plasma samples collected before, during and after insertion of CIDR. There was a significant increase in plasma cortisol concentrations (p<0.01) after insertion of CIDR. Mean (± SEM) plasma cortisol concentrations increased from 1.3 ± 0.4 to a peak of 8.8 ± 1.1 ng/ml at 5 h and then decreased to basal concentrations at 7 h after insertion of the device. In conclusion, the insertion of intra-vaginal device causes an increase in plasma cortisol concentrations in beef cows, although the pathophysiological significance of the elevation of cortisol is not known.

Adrenocortical response in cows after intramuscular injection of long-acting adrenocorticotropic hormone (tetracosactide acetate zinc suspension).

The objectives of this study were first to show adrenocortical response to a long-acting adrenocorticotropic hormone preparation (tetracosactide acetate zinc suspension) (ACTH-Z) and its effect on adrenocortical function in beef cows (Experiment 1) and second to apply the ACTH-Z challenge in dairy cows based on cortisol concentrations in milk collected at routine milking (Experiment 2). In Experiment 1, four beef cows in luteal phase were challenged with ACTH-Z, and plasma cortisol concentrations were determined for 48 h after the injection at 30-min to 2-h intervals. A rapid ACTH test was conducted 3 days before and 2 h after the completion of ACTH-Z injection for 48 h to investigate the effect on adrenocortical function. Plasma cortisol concentrations increased significantly 30 min after ACTH-Z injection (p < 0.001), and the high cortisol levels were maintained for approximately 10 h after the injection. In Experiment 2, eight dairy cows were subjected to ACTH-Z challenge 1-2 weeks and 4-5 weeks post-partum. Blood and milk samples were taken at morning and afternoon milking. All the cows showed a significant increase in cortisol concentrations in plasma as well as in skim milk 8 h after ACTH-Z injection 1-2 weeks and 4-5 weeks post-partum (p < 0.001). There was a significant correlation between plasma and skim milk cortisol concentrations 8 h after ACTH-Z challenge (r = 0.74, p < 0.001). The results obtained in this study suggest that elevated levels of plasma cortisol are maintained for approximately 10 h after ACTH-Z treatment without adverse effect on adrenocortical function and a long-acting ACTH-Z challenge based on cortisol concentrations in milk, which were collected at the morning and the afternoon milking, can be a useful tool to monitor adrenocortical function in cows.

Comparison in effect of Heatsynch with heat detection aids and CIDR-Heatsynch in dairy heifers.

The objective of the present study was to determine whether oestrous detection with the help of oestrous detection aids during the Heatsynch without timed AI protocol is equally effective with the progesterone-combined protocol in dairy heifers. A total of 148 heifers were randomly assigned to one of the two groups. A group of heifers treated with Heatsynch with heat detection aids (n = 72) received GnRH on day 0, prostaglandin F(2alpha) (PGF(2alpha)) on day 7 and oestradiol benzoate (EB) on day 8, while in controlled internal drug release (CIDR)-Heatsynch group (n = 76), CIDR was included during a period from GnRH to PGF(2alpha). Heifers were checked for oestrus twice daily, i.e. from 09:00 to 10:00 hours and from 15:00 to 16:00 hours starting on day 2 for Heatsynch group and on day 8 in CIDR-Heatsynch group, and continued up to day 12. KAMAR heat mount detector (KAMAR Inc., Steamboat Springs, CO, USA) and ALL-WEATHER PAINTSTIK (LA-CO Industries Inc., Elk Grove Village, IL, USA) were used as heat detection aids. AI was conducted within 1 h after confirming oestrus in 72 heifers, while 19 animals were transferred with embryo 7 days after oestrus according to the request of the owners. Premature oestrus before PGF(2alpha) injection occurred in 18% of Heatsynch group. Of 13 heifers which showed premature oestrus, six were inseminated and two of them conceived. Oestrus detection rate within 12 days after initiation of the protocols did not differ between the two groups (94% vs 95%). There was no difference in the conception rate after first AI (including heifers that were inseminated before PGF(2alpha) injection) and embryo transfer between Heatsynch with heat detection aids and CIDR-Heatsynch groups (36% vs 44% and 70% vs 56%). It is concluded that the use of heat detection aids to monitor the occurrence of premature oestrus prior to PGF(2alpha) injection in Heatsynch protocol in dairy heifers was equally effective to the inclusion of CIDR.

Plasma progesterone profile in ovariectomized beef cows after intra-vaginal insertion of new, once-used or twice-used CIDR.

Objective of this study was to show plasma progesterone concentrations in ovariectomized beef cows after treatment with new, once-used and twice-used controlled internal drug-releasing devices (CIDRs). Four ovariectomized beef cows were used for the experiment. Plasma concentrations of progesterone were quantified using a validated ELISA. The CIDR was inserted into vagina of cows by using a standard CIDR applicator and then removed 7 days after insertion. One week later, once-used CIDR was inserted and removed on day 7. Twice-used CIDR was, then inserted at an interval of 7 days. Mean plasma concentrations of progesterone 24 h after new CIDR insertion was 4.0 +/- 0.1 ng/ml, which thereafter decreased gradually to 1.4 +/- 0.1 ng/ml at day 7. In cows treated with once-used CIDR or twice-used CIDR, mean plasma progesterone concentrations at day 1 were 2.4 +/- 0.2 or 1.8 +/- 0.2 ng/ml and 1.0 +/- 0 or 0.9 +/- 0.1 ng/ml at day 7 respectively. The results suggest that once-used CIDR may be still effective to produce luteal phase progesterone concentrations in plasma in non-suckling beef cows.

Moisture-dependent crystallization of amorphous lamotrigine mesylate.

A commercially available computer-controlled vacuum moisture balance was used for determining moisture sorption isotherms of freeze-dried and spray-dried lamotrigine mesylate drug substance and freeze dried drug product containing mannitol. The presence or absence of desorption hysteresis and the characteristics of the weight-versus-time profile as a sample was exposed to a defined relative humidity ramp were sensitive indicators of moisture-induced crystallization. Combination of the moisture sorption data with polarized light microscopy, differential scanning calorimetry, and X-ray powder diffraction provided qualitative verification of the crystallization with < 50 mg of sample. The normalized water loss during crystallization was used to detect as little as 2% amorphous content in physical mixtures of amorphous and crystalline lamotrigine mesylate. Moisture sorption, water plasticization, and crystallization properties of amorphous forms prepared by spray drying and freeze drying were nearly identical. Cofreeze-drying lamotrigine mesylate with D-mannitol resulted in a mixture of amorphous lamotrigine mesylate with properties similar to those of spray-dried or freeze-dried materials and crystalline D-mannitol. The amount of water needed for crystallization over a time scale observable in the moisture balance was considerably more than the amount needed to lower the glass transition temperature of the sample to the operating temperature of the instrument. This result illustrated the importance of time scale effects in determining critical moisture levels for crystallization from the amorphous state.

Crystal structure prediction for eniluracil.

State-of-the-art molecular modeling tools were used to predict the crystal structure of eniluracil, a compound for which it has not been possible to grow a single crystal. Two methods were used, one that incorporates molecular structure and powder X-ray diffraction data and another that employs molecular structure and lattice energy calculations into the search algorithm. Two structures were identified, one with P2(1)/c and the other with P2(1) symmetry, both of which are consistent with the infrared and Raman spectra. A detailed analysis of the simulated and experimental powder X-ray diffraction patterns indicates that the P2(1)/c structure is the best representation of the crystal structure.

Contractile properties of slow and fast muscle following tourniquet ischemia.

Tourniquet application is commonly used during surgery on an extremity to create a bloodless field. Investigations have focused on the ultrastructural, histochemical, and biochemical effects of tourniquet ischemia on muscle. Few studies, however, have examined the influence of tourniquet ischemia on the contractile properties of muscle. The purpose of this study was not only to examine this latter consideration, but also to determine whether slow and fast muscles exhibit a differential response. In adult male guinea pigs, the plantaris and soleus muscles of control (N = 5) and experimental legs (N = 5) were tested for time-peak-tension (TPT), one-half relaxation time (1/2RT), maximal twitch tension (Pt), and maximal tetanic tension (Po). The experimental leg was subjected to a 2 hour tourniquet which was placed around the thigh. Muscles of this leg were tested following a 2 hour recovery period. In three of the five animals, no response could be elicited from either the plantaris or soleus muscles of the experimental leg. In those instances where the experimental muscles were capable of generating force, the plantaris was clearly more effected. While tension production in the soleus was reduced by approximately 55%, the plantaris exhibited approximately a 90% decrease in tension output. Furthermore, both TPT and 1/2RT demonstrated consistent changes. These results indicate that the contractile properties of both the soleus and plantaris are dramatically effected by a 2 hour tourniquet. They further suggest that there may be a differential response based upon fiber type.

Spontaneous recovery or persistence of postpartum endometritis and risk factors for its persistence in Holstein cows.

It has been stated that postpartum endometritis in dairy cows has a tendency to cure without intervention. The objectives of this field study, therefore, were to determine the proportions of cows with spontaneous clinical recovery or persistence of postpartum endometritis and to determine some risk factors for its persistency in dairy cows (Bos taurus). Holstein-Friesian cows (n=441 lactations) from seven dairy herds were examined monthly by vaginoscopy and transrectal palpation. A cow was considered to have "postpartum endometritis" if it had pus in the cervico-vaginal discharge at the first postpartum examination during Days 15 to 60 (Day 0=day of calving); this was classified as mild, mucopurulent, or purulent endometritis, or endometritis with fluid in uterus. Furthermore, a cow with evidence of endometritis at least once during Days 61 to 150 was considered to have "persistence (or recurrence) of endometritis." A total of 104 (23.6%) lactations had postpartum endometritis, of which 25.3% had persistence or recurrence of clinical endometritis. Cows with persistence or recurrence of endometritis became pregnant at a slower rate (hazard ratio [HR]=0.28; P<0.001) than those with no endometritis until Day 150. Calving in summer (odds ratio [OR]=7.00; P=0.04), early postpartum complications (OR=6.58; P=0.05), moderate (OR=4.03; P=0.08) and severe (OR=30.99; P=004) degrees of urovagina, and mucopurulent (OR=9.54; P=0.02) and purulent (OR=5.70; P=0.04) endometritis were risk factors for the persistence or recurrence of endometritis. Furthermore, 10.6% of cows that had not shown signs of postpartum endometritis had a new diagnosis of endometritis during Days 61 to 150. Some risk factors for the new diagnosis of endometritis beyond Day 60 were early postpartum complications (OR=2.82; P=0.03) and moderate (OR=5.00; P=0.001) or severe (OR=12.63; P<0.001) degrees of urovagina. In conclusion, approximately one quarter of cows with postpartum endometritis had persistence of endometritis until or beyond the breeding period. Risk factors for the persistence of clinical endometritis were summer calving, early postpartum complications, clinically relevant urovagina, and clinically relevant endometritis within 2 mo postpartum.