Effects of spray-dried animal plasma in calf milk replacer on health and growth of dairy calves.

Male Holstein calves (n = 120) purchased from local dairy farms were fed one of three calf milk replacers for 42 d. Experimental milk replacers were formulated to contain whey protein concentrate (WPC) as the primary protein source or WPC plus 5% spray-dried bovine plasma (SDBP) or spray-dried porcine plasma (SDPP). The SDPP was heated to remove heat-insoluble materials and provide products with similar IgG content. Calves were also fed commercial calf starter and water for ad libitum consumption. Intake, change in body weight (BW), feed efficiency, morbidity and mortality were determined. Mortality was 10, 3, and 2 in calves fed WPC, SDBP, and SDPP treatments, respectively. Morbidity, measured as the number of days that calves had diarrhea was reduced by 30% when SDBP or SDPP were fed. Calves had diarrhea for 6.9, 3.9, and 4.7 d during the 42-d study when fed commercial calf milk replacer containing WPC, SDBP, and SDPP, respectively. Fecal scores tended to be reduced and feed efficiency tended to be improved when SDBP or SDPP were fed. Mean intakes of total dry matter during the 42-d study were greater when calves were fed SDBP or SDPP and were 661, 710, and 684 g/d for calves fed WPC, SDBP, and SDPP, respectively. Mean BW gains from d0 to 42 were 231,261, and 218 g/d, respectively. Calves fed SDPP tended to have lower BW gain during the first 28 d of the study. However, difference in daily BW gain from d 1 to 28 was only 39 g/d. Inclusion of SDBP or SDPP in milk replacer reduced morbidity and mortality of milk-fed dairy calves.

Absorption of protein and IgG in calves fed a colostrum supplement or replacer.

Newborn Holstein bull calves (n = 32) were assigned to receive a colostrum supplement (CS) containing defibrinated bovine plasma or a colostrum replacer (CR) containing an immunoglobulin concentrate obtained by concentrating the immunoglobulin (Ig)G fraction of bovine plasma. The CS and CR contained 11.1 and 21.2% of dry matter as IgG, respectively. Each animal was fed two 454-g feedings at 1 and 8 h of age. The two feedings of CS and CR provided 95 and 187 g of IgG, respectively. Mean plasma IgG at 24 h of age was 8.0 and 13.6 g/L in calves fed CS and CR, respectively, indicating acceptable absorption of Ig from both sources. Mean apparent efficiency of IgG absorption in calves fed CS and CR were 33 and 30%, respectively, and did not differ between treatments. Mean plasma total protein at 24 h in calves fed CS and CR were 4.99 and 4.98 g/dl and did not differ between treatments. Increased plasma protein concentration from 0 to 24 h (4.5 g/L) was lower than the mean increase in plasma IgG concentration during the same period (10.3 g/L), indicating altered protein profile in the blood during the first 24 h of life. Correlation between plasma IgG and total protein at 24 h of age was significant within treatment, but the relationship between IgG and protein in plasma at 24 h varied between treatments. Predicted plasma total protein concentrations at 10 g of IgG/L of plasma at 24 h were 5.4 and 4.2 g/dl, in calves fed CS and CR, respectively. Prediction of plasma IgG concentration using total plasma protein may be inappropriate when calves are fed CS or CR.

Detection of encephalitis viruses in mosquitoes (Diptera: Culicidae) and avian tissues.

ABSTRACT Diagnostic assays for the detection of St. Louis encephalitis (SLE) and western equine encephalomyelitis (WEE) viruses in mosquito pools and avian tissues were compared for sensitivity, accuracy and specificity. The in situ enzyme immunoassay (EIA), plaque assay on Vero cells, passage in Aedes albopictus Skuse C6/36 and C7/10 cells, antigen capture enzyme immunoassay (AC-EIA), and single and multiplex reverse transcription-polymerase chain reactions (RT-PCR) were evaluated using pools of 50 mosquitoes containing 1-2 experimentally infected individuals. RT-PCR was the most sensitive assay, with a detection limit of <0.1 plaque forming unit. AC-EIA was the fastest and most economical procedure, but was the least sensitive, detecting only 38% of positive pools. The in situ EIA included initial virus amplification on Vero cells, thereby improving assay sensitivity to detect 68% of positive pools. Passage in C6/36 and/or C7/10 cell culture revealed the presence of infectious virus in samples positive by RT-PCR, but initially negative by plaque assay on Vero cell culture, indicating that detection was related to assay sensitivity and not to the absence of intact infectious virus. Combining WEE and SLE RT-PCR assays into a multiplex assay reduced sensitivity, but stilldetected viral RNA at titers below plaque assay sensitivity. Plaque assay on Vero cells, mosquito cell passage, and several RT-PCR procedures were evaluated for their ability to detect WEE and SLE in white-crowned sparrow tissues during acute and chronic stages of infection. All assays detected virus during acute infection at times of high viremia; however, only RT-PCR assays were positive by day 7 when virus was not detected in sera. RT-PCR detected SLE RNA in spleen tissue from one bird 51 d after infection. Assay sensitivity also was compared using extracts of homogenized bird organs spiked with known titers of WEE and SLE. Trizol RNA extraction followed by Qiagen one-step RT-PCR was the most sensitive method, but occasionally resulted in the presence of secondary bands confounding interpretation and requiring confirmatory assays. A balanced surveillance program should combine systems that allow the detection of new agents and the sensitive monitoring of endemic agents to provide an early warning of pending health risks.

Anesthesia for selected procedures.

This article reviews selected procedures for which a particularly close working relationship between the surgeon and the anesthesiologist is essential for patient safety. Anesthetic considerations for upper and lower gastrointestinal endoscopies, bronchoscopy for aspirated foreign bodies, resection of mediastinal masses, thoracotomies for procedures requiring one-lung anesthesia, and surgery for burn patients are reviewed.

Anesthesia outside the operating room.

Many new diagnostic and surgical procedures rely on immobile equipment such as computed tomography or magnetic resonance scanners, biplanar fluoroscopes, or radiotherapy units. To facilitate these procedures in infants and children, anesthesiologists must provide services in a variety of unique environments. This article reviews the anesthetic equipment and techniques that have been adapted to provide anesthesia for children outside the operating room.

Intramedullary secretory gangliocytoma.

An 8-year-old boy developed severe systemic hypertension during resection of an intramedullary tumor. The histological, ultrastructural and immunocytochemical characteristics of the tumor are those of a gangliocytoma. Based on the demonstration of tyrosine hydroxylase in neuronal tumor cells, it is postulated that catecholamine secretion was responsible for the systemic hypertension.

Dopamine reverses cardiovascular depression of toxic doses of pentobarbitone in dogs.

Pentobarbitone, 20 mg X kg-1 IV followed by infusion of 25 mg X kg-1 X hr-1, produced a progressive decrease in mean arterial pressure in dogs from 113 +/- 17 mmHg (SD) after one hour of infusion to 82 +/- 21 mmHg after 3.5 hours and to 49 +/- 22 mmHg after 5.5 hours. EEG silence occurred at 3.6 +/- 0.6 hours. In dogs similarly treated with pentobarbitone, a two hour infusion of dopamine 5 micrograms X kg-1 X min-1 beginning at the time of EEG silence prevented the further decrease in pressure and restored pressure to 87 +/- 18 mmHg. The mechanism for this effect of dopamine was an increase in cardiac output as systemic vascular resistance was unaffected by dopamine. The cardiac output increase was mainly the result of an increase in stroke volume as heart rate increased only slightly. Since reduced stroke volume was the main reason why pentobarbitone lowered blood pressure, the effect of dopamine on stroke volume and thus on blood pressure makes it an appropriate antagonist to the cardiovascular effects of toxic doses of pentobarbitone.

Effect of age on epinephrine-induced arrhythmias during halothane anaesthesia in pigs.

The effect of age on the arrhythmogenicity of epinephrine during halothane anaesthesia was studied in pigs of two different age groups. At a stable alveolar concentration of 0.84 volumes per cent halothane, ventricular arrhythmias could not be elicited in one- to three-day-old pigs by a 100 micrograms X kg-1 infusion of epinephrine. PVCs were produced in 50- to 55-day-old pigs at a mean epinephrine dose of 9.55 micrograms X kg-1. Heart rate, systolic blood pressure, and rate-pressure product were significantly higher before and during the epinephrine infusion in the 50- to 55-day-old pigs. It is concluded that there is an age dependent effect upon epinephrine induced arrhythmias during halothane anaesthesia in pigs.

Comparison of cardiovascular effects of thiopental and pentobarbital at equivalent levels of CNS depression.

Thiopental and pentobarbital have been used in high doses to protect the brain from injury following hypoxia or to reduce intracranial pressure. This study was performed to determine whether these barbiturates differ in cardiovascular effects when present in plasma concentrations that produce equivalent CNS effects. The effects of thiopental and pentobarbital on heart rate, stroke volume/kg, cardiac output/kg, systemic vascular resistance, mean arterial pressure, and central venous pressure were statistically indistinguishable at plasma concentrations of each barbiturate ranging from 50% to 100% of their concentration producing EEG silence. Three of the seven dogs given thiopental developed ventricular bigeminy at plasma concentrations ranging from 45% to 65% of their concentration producing EEG silence. Lidocaine (1.4-2.0 mg/kg intravenously) reversed the bigeminy to sinus rhythm. When given more than the amount needed to produce a flat EEG, five of the seven dogs given thiopental died, but all dogs given pentobarbital survived. Pentobarbital may be a better choice than thiopental when large doses are indicated.

Anaesthetic implications of neonatal necrotizing enterocolitis.

A retrospective analysis of infants with necrotizing enterocolitis was done to evaluate the effects of preoperative abnormalities upon anaesthesia and mortality. Mortality was significantly increased in infants weighing less than 1500 grams (p less than .001). Sixty-nine per cent of the infants had hyaline membrane disease and 35 per cent had platelet counts less than 50 X 10(9) cells/litre (50,000/mm3). Perioperative problems include peritonitis, sepsis, hypovolaemia, acidosis, and prematurity. Other ramifications of prematurity and anaesthesia are discussed.