120 research outputs found
The usage of pelvimetry to predict dystocia in cattle
Pelvimetry is the measurement of the dimensions of the pelvis, measured internally or externally, and is typically conducted with the aid of a pelvimeter. Intrapelvic dimensions, namely the intrapelvic height and width, are used to calculate pelvic are a which has a moderate to high degree of heritability. Pelvic area measurements are associated with calving difficulty and have been used by producers to select for heifers to be included in their breeding herd
Electrocardiographic findings in 130 hospitalized neonatal calves with diarrhea and associated potassium balance disorders
Background: Hyperkalemia in neonatal diarrheic calves can potentially result in serious cardiac conduction abnormalities and arrhythmias. Objective: To document electrocardiographic (ECG) findings and the sequence of ECG changes that are associated with increasing plasma potassium concentrations (cK(+)) in a large population of neonatal diarrheic calves. Animals: One hundred and thirty neonatal diarrheic calves (age 21 days). Methods: Prospective observational study involving calves admitted to a veterinary teaching hospital. Results: Hyperkalemic calves (cK(+): 5.8-10.2, blood pH: 6.55-7.47) had significantly (P6.5 mmol/L, S wave amplitude voltage decreased when cK(+) >7.4 mmol/L, QRS duration increased when cK(+) >7.8 mmol/L, J point amplitude increased when cK(+) >7.9 mmol/L, and ST segment angle increased when cK(+) >9.1 mmol/L. P wave amplitude was characterized by a second common break point at cK(+)=8.2 mmol/L, above which value the amplitude was 0. Conclusions and Clinical Importance: Hyperkalemia in neonatal diarrheic calves is associated with serious cardiac conduction abnormalities. In addition to increased S and T wave amplitude voltages, alterations of P and Ta wave amplitudes are early signs of hyperkalemia, which is consistent with the known sensitivity of atrial myocytes to increased cK(+)
Clinical utility of calf front hoof circumference and maternal intrapelvic area in predicting dystocia in 103 late gestation Holstein-Friesian heifers and cows
The objective of this study was to determine the clinical utility of measuring calf front hoof circumference, maternal intrapelvic area, and selected morphometric values in predicting dystocia in dairy cattle. An observational study using a convenience sample of 103 late-gestation Holstein-Friesian heifers and cows was performed. Intrapelvic height and width of the dam were measured using a pelvimeter, and the intrapelvic area was calculated. Calf front hoof circumference and birth weight were also measured. Data were analyzed using Spearman's correlation coefficient (rs), Mann–Whitney U test, and binary or ordered logistic regression; P 0.068 cm/cm2). Determining the ratio of calf front hoof circumference to maternal intrapelvic area has clinical utility in predicting the calving difficulty score in Holstein-Friesian cattle
Clinical signs and outcomes of beef cattle undergoing cesarean section because of dystocia
OBJECTIVE: To characterize signalment, clinical signs, reproductive history, surgical management, and outcomes of beef cattle undergoing cesarean section because of dystocia at a veterinary teaching hospital. Design: Retrospective case series with nested cohort study. Animals: 173 beef cattle admitted to a veterinary teaching hospital from 2001 through 2010 that underwent cesarean section because of dystocia. Procedures: Medical records were reviewed and information collected on cattle signalment; reproductive history; cause of dystocia; anesthetic protocol; surgical management; number, sex, and body weight of calves delivered (alive or dead); perioperative treatment; duration of hospitalization; and discharge status. A questionnaire regarding postoperative fertility was mailed to all owners, and owners who did not respond were contacted via telephone. Results: Overall mortality rate for calves was high, with 37.6% (62/165) of calves delivered dead or dying ≤ 24 hours after cesarean section. Mortality rate was higher for female versus male calves and for calves from dams with signs of labor for ≥ 3 hours versus < 3 hours before hospital admission. Overall mortality rate for dams was low, with only 10 of 161 (6.2%) dams failing to survive for ≥ 21 days after hospital discharge. Postoperative fertility rate was acceptable, with 75% (44/59) of dams that were rebred after cesarean section giving birth to ≥ 1 live calf. Conclusions and Clinical Relevance: Cesarean section was a clinically useful method for resolving dystocia in beef cattle, providing a high dam survival rate and an acceptable postoperative fertility rate. Beef cattle producers should seek veterinary assistance whenever clinical signs of dystocia are noticed, preferably within 6 hours after onset of parturition
Clinical utility of plasma fructosamine concentration as a hypoglycemic biomarker during early lactation in dairy cattle
Background: Plasma fructosamine concentration ([FRA]) is a widely used long term hyperglycemic biomarker in humans and dogs, but its clinical usefulness as a hypoglycemic biomarker in dairy cattle is uncertain. Objectives: To evaluate the relationship between plasma [FRA] and glucose concentration ([gluc]) as well as indices of energy balance during early lactation in dairy cattle, and to characterize the influence of plasma total protein concentration ([TP]) and albumin concentration ([albumin]) on [FRA]. Animals: Convenience sample comprising 103 periparturient Holstein-Friesian cattle. Methods: Plasma [gluc], [TP], [albumin], and other clinicopathologic indices of energy status were determined periodically from Day 4 postpartum. Body condition score (BCS) was assessed, and backfat thickness (BFT) and longissimus dorsi muscle thickness (LDT) were measured ultrasonographically. Plasma [FRA] was measured at approximately 28 days postpartum. Associations between plasma [FRA] and study variables were evaluated using Spearman's rho and stepwise forward linear regression. statistical significance was declared at P < 0.05. Results: A positive association was detected between plasma [FRA] and mean plasma [gluc] from Days 4-28 postpartum (rs = +0.36, P < 0.001), and between plasma [FRA] and LDT (rs = +0.28, P = 0.007), BCS (rs = +0.23, P = 0.029), and BFT (rs = +0.21, P = 0.043). Multivariable regression identified a positive association between plasma [FRA] and mean plasma [gluc] and [albumin] from Days 4-28 postpartum. Correcting plasma [FRA] for [albumin] improved the association (rs = +0.46, P < 0.001) between plasma [FRA] and mean plasma [gluc]. Conclusions and clinical importance: Plasma [FRA] does not provide a clinically useful method for quantifying the magnitude of hypoglycemia or negative energy balance in dairy cows during early lactation
Changes in skeletal muscle thickness and echogenicity and plasma creatinine concentration as indicators of protein and intramuscular fat mobilization in periparturient dairy cows
High-producing dairy cows experience a state of negative energy balance in the periparturient period that is partially addressed by increasing the rate of fat and protein mobilization. Previous studies have focused on the rate of fat mobilization, and consequently the rate of protein mobilization has not been well characterized. The objective of this study was therefore to determine the change in indicators of muscle mass during early lactation using ultrasonographic measurement of muscle thickness and changes in plasma creatinine concentration. The maximum thickness of the gluteus medius and longissimus dorsi muscles of 106 Holstein cows (34 primiparous, 72 multiparous) was determined ultrasonographically on d −3, 0, 3, 7, 14, 21, and 28 relative to the day of parturition. Plasma creatinine concentration was measured periodically during the same period. Mixed models analysis and Passing-Bablok regression were used to analyze the data. Gluteus medius thickness, longissimus dorsi loin thickness (LDLT), and longissimus dorsi thoracic thickness (LDTT) were decreased at 28 d postpartum compared with d 3 antepartum. Plasma creatinine concentration was weakly associated with gluteus medius thickness, LDLT, and LDTT (Spearman's rho = 0.31, 0.39, and 0.32, respectively). Plasma creatinine concentration in primiparous and multiparous cows at 28 d postpartum decreased by 0.24 and 0.30 mg/dL, respectively, compared with values 3 d antepartum. We concluded that ultrasonographic measurement of LDLT and LDTT and change in plasma creatinine concentration may provide practical methods for monitoring the rate of protein mobilization in periparturient dairy cows. Ultrasonographic examination of LDLT and LDTT therefore complements ultrasonographic measurement of backfat thickness and may be useful in the evaluation of energy reserve mobilization in periparturient dairy cows
Synthetic strategies for preparing BEDT-TTF derivatives functionalised with metal ion binding groups
The syntheses of BEDT-TTF (ET) derivatives with potential metal ion binding pyridyl, bipyridyl and terpyridyl groups are achieved either by stepwise construction of the organosulfur core or via reactions of hydroxymethyl-ET for which a cheap and efficient four step route is reported. The tosylate of hydroxymethyl-ET, reported for the first time, undergoes nucleophilic substitutions with pyridyl, bipyridyl- and terpyridyl-thiolates to give new donors. The X-ray crystal structures of two substituted ET derivatives show considerable deviation of the organosulfur donor system from planarity by bending about the short molecular axis of the ET group
Asymmetric triplex metallohelices with high and selective activity against cancer cells
Small cationic amphiphilic α-helical peptides are emerging as agents for the treatment of cancer and infection, but they are costly and display unfavourable pharmacokinetics. Helical coordination complexes may offer a three-dimensional scaffold for the synthesis of mimetic architectures. However, the high symmetry and modest functionality of current systems offer little scope to tailor the structure to interact with specific biomolecular targets, or to create libraries for phenotypic screens. Here, we report the highly stereoselective asymmetric self-assembly of very stable, functionalized metallohelices. Their anti-parallel head-to-head-to-tail ‘triplex’ strand arrangement creates an amphipathic functional topology akin to that of the active sub-units of, for example, host-defence peptides and p53. The metallohelices display high, structure-dependent toxicity to the human colon carcinoma cell-line HCT116 p53++, causing dramatic changes in the cell cycle without DNA damage. They have lower toxicity to human breast adenocarcinoma cells (MDA-MB-468) and, most remarkably, they show no significant toxicity to the bacteria methicillin-resistant Staphylococcus aureus and Escherichia coli.
At a glanc
Cubic Interactions in PP-Wave Light Cone String Field Theory
We use the supergravity modes to clarify the role of the prefactor in the
light-cone superstring field theory on PP-wave background. We verify some of
the proposals of the recent paper hep-th/0205089 and give further evidence for
the correspondence between N=4 SYM gauge theory and string theory on PP-wave.
We also consider energy-preserving processes and find that they give vanishing
cubic interaction Hamiltonian matrix.Comment: 16+1 pages, no figures, LaTeX (v3: references, minor changes and a
clarification about Neumann matrices added; to appear in Physical Review D
Chiral Heterocyclic Ligands. XI. Self-assembly and X-Ray Crystal Structures of Chiral Silver Coordination Polymers of (S)-(-)-Nicotine
Three chiral coordination polymers have been prepared by reaction of (S)-(-)-nicotine with silver(I) salts. X-Ray crystal structure determinations revealed that these all contain polymer chains in which the nicotine molecule acts as a bridging ligand between four-coordinate silver atoms. In one
case additional bridging by nitrate anions leads to a three-dimensional network structure
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