Changes in fermentation and animal performance during recovery from classical diet-induced milk fat depression using corn with differing rates of starch degradability

Diet-induced milk fat depression (MFD) is a multifactorial disorder that can be triggered by a variety of conditions. Feeding high amounts of starch and unsaturated fatty acids has been shown to reduce milk fat yield and composition, as well as alter ruminal biohydrogenation patterns. However, little is known about how starch degradability in the rumen influences recovery from diet-induced MFD and if production of milk fat-inhibiting isomers will persist following an episode of MFD. The objective of this study was to evaluate production performance and ruminal fermentation in cows recovering from MFD when corn with a low or high starch degradability is fed. Six ruminally fistulated Holstein cows were used in a crossover design with 2 periods. During each period, MFD was induced for 10 d by feeding a diet with low fiber, high starch, and high unsaturated fatty acid. The polyunsaturated fatty acid concentration of the diet during the induction phase was modified primarily through inclusion of soybean oil. Following induction, cows were switched to either a high degradable starch recovery diet (HDS) or a low degradable starch recovery diet (LDS) for 18 d. The 7-h starch degradability was 66.5% for LDS and 87.8% for HDS. Milk was collected every 3 d for component and fatty acid analysis. On d 0, 4, 7, 10, 16, 22, and 28 of each period, ruminal pH and rumen fluid were collected every 2 h. Milk fat yield and composition was reduced during MFD induction and progressively increased by day in both HDS and LDS during recovery. Dry matter intake was similar among treatments and increased steadily over time during recovery. Preformed fatty acids were greater for HDS-fed animals, and de novo fatty acid in milk fat was greater for LDS-fed animals. Milk trans-10 C18:1 tended to be greater for HDS, and trans-10,cis-12 conjugated linoleic acid was significantly greater for HDS. cis-9,trans-11 conjugated linoleic acid was not affected by starch degradability during recovery. Total volatile fatty acids, butyrate, and valerate tended to differ or differed with recovery treatment, but ruminal pH and ammonia concentration were unaffected. The HDS diet responded similarly to the LDS diet during recovery with regard to milk fat percentage, but milk and fat yield tended to consistently be lower in HDS. When considering approaches to ameliorate diet-induced MFD, the degradability of the starch within rations should be evaluated. Although animal performance was similar, some trans fatty acid isomers were persistent in the milk through the recovery phase with HDS-fed animals, suggesting that milk fat synthesis might be potentially inhibited and biohydrogenation pathways modified in the rumen following an episode of MFD.

The primary sequence of cytochrome P450tyr, the multifunctional N-hydroxylase catalyzing the conversion of L-tyrosine to p-hydroxyphenylacetaldehyde oxime in the biosynthesis of the cyanogenic glucoside dhurrin in Sorghum bicolor (L.) Moench

The heme thiolate protein cytochrome P450tyr is a multifunctional N-hydroxylase converting L-tyrosine to p-hydroxyphenylacetaldehyde oxime in the biosynthesis of the cyanogenic glucoside dhurrin in Sorghum bicolor (Sibbesen et al. (1995) J. Biol. Chem. 270, 3506-3511). Using a polyclonal antibody toward cytochrome P450tyr and oligonucleotide probes designed on the basis of amino acid sequences of tryptic fragments, a full-length cDNA clone encoding cytochrome P450tyr has been isolated and sequenced. The open reading frame encodes a protein with a molecular mass of 61,887 Da. A comparison with the amino acid sequencing data demonstrates that the protein is not subjected to posttranslational modification at the N- and C-terminal ends except for the removal of the N-terminal methionine residue. Highest positional identity (30.8%) is found to the 3',5'-flavonoid hydroxylase of petunia (CYP75A1) and to a cytochrome P450 sequence from avocado of unknown function (CYP71A1). Consequently, cytochrome P450tyr is assigned as the first member of a new cytochrome P450 family denoted CYP79. The N-terminal region of cytochrome P450tyr contains the four domains characteristic for cytochrome P450 enzymes of the endoplasmic reticulum (ER) in animals. The amino acid sequence before the proline-rich domain is longer in cytochrome P450tyr and in four cytochrome P450s presently available from other monocotyledoneous plants compared to the sequences from dicotyledoneous plants but is concluded to contain a single transmembrane helix with the N-terminal located in the lumen of the ER and the bulk of the protein protruding into the cytoplasm. The heme-binding cysteine residue of cytochrome P450tyr is recognizable at position 493 but this region deviates from the consensus sequence by having an unusual alanine residue at position 495. The central region of helix I contains three residues, Ala-352, Asn-355, and Pro-356, deviating from the consensus sequence. CYP56 is the only other known cytochrome P450 using tyrosine as substrate and contains the same Asn-Pro substitution in the consensus sequence of helix I indicating the importance of these residues in defining substrate specificity. The conserved threonine residue which normally helps to form the oxygen binding pocket is absent. The cytochrome P450tyr sequence represents the first amino acid sequence of a functionally characterized cytochrome P450 enzyme from a monocotyledoneous plant and the first sequence of a membrane-bound N-hydroxylase with high substrate specificity. Multifunctional N-hydroxylases of the cytochrome P450 type have not been previously demonstrated to catalyze biosynthetic pathways in living organisms.

Heterotopic ossification in children with burns: two case reports

Heterotopic ossification is the formation of ectopic bone in soft tissue, and has been reported as a rare complication in pediatric burn patients. At our hospital, two 86% body surface area burn patients developed heterotopic ossification in the shoulder, elbows, distal femur, proximal tibia, fibula, and ribs approximately four months after the burn injury. These two rare and unusual cases are presented documenting the clinical involvement, radiological studies, laboratory data, as well as treatment of their heterotopic ossification. Discussion will focus on the incidence, diagnosis, pathophysiology, and treatment of heterotopic ossification in burn patients and how this information relates to the specific diagnosis and management of the complication of heterotopic ossification in the burn child.

Upper extremity strength and function in children with spinal muscular atrophy type II

Upper extremity strength and function in a sample of ten children with spinal atrophy type II was determined using manual muscle testing, a sphygmomanometer, and a pinchometer. Functional abilities were recorded on self-report forms. Overall strength in this sample was determined to be 35% to 40% of normal. Repeated-measures analysis of covariance revealed no change with time in proximal or distal strength. Six children were capable of at least 1/2 pound of force in pinch or gross grasp vs four children with zero force in one of these measures. Ability to produce a measurable force in pinch or gross grasp was found to be associated with independence in mobility, hand function, and ADL by Fisher exact test (p = .02). These data document the weak, but stable, muscle force present in these children and relate the strength of function.

Flexibility and Strength Measures in Children Participating in a Cardiac Rehabilitation Exercise Program

In brief: The purpose of this study was to evaluate the effects of a structured rehabilitation program on the strength and flexibility of children with surgically corrected congenital heart disease. Twelve children (eight boys, four girls) participated in one-hour exercise classes, two times per week for 12 weeks. Results showed minimal changes in upper extremity strength, but lower extremity strength improved 10% and 5% on the right and left sides, respectively. Flexibility improved about 25% in the lower extremities. Improvement was also noted in neck flexion, hip and oblique rotation, hamstring and low back stretch, and heel cord stretch. These findings indicate that this type of program can improve strength and flexibility in children who have undergone complex heart surgery and may help them achieve a more normal life-style.

Vocal cord paralysis in children studied by monopolar electromyography

Twelve children with symptoms of vocal cord paralysis were studied by monopolar needle electromyography. Recordings were used to verify complete or partial paralysis as well as to evaluate the etiology of the problem, paralytic or mechanical. These results then were useful in patient management. The monopolar electromyographic technique is of value in evaluating and treating vocal cord problems.

Severe multicore disease associated with reaction to anesthesia

Multicore disease is a nonprogressive myopathy. To our knowledge, in all previous cases, the clinical course has been benign with no deaths attributed to it. We describe a patient who presented as a floppy baby and remained weaker throughout his life than any other patients previously described. Biopsy findings were characteristic of multicore disease. However, at age 21/2 years, our patient developed congestive heart failure that was easily controlled with digitalis and diuretics. Shortly after cardiac catheterization, the patient developed a high, unexplained fever and died 26 hours later despite aggressive attempts at resuscitation. Therefore, patients with multicores in skeletal muscle may have severe weakness and may also have a predisposition to complications subsequent to anesthesia.

Neonatal spinal cord injury

In this review of the prognosis of patients having neonatal spinal cord injury, findings in 3 patients and 11 case histories from the literature are evaluated as to obstetric complications, clinical and pathologic examinations, and follow-up data from 2 to 12 years, or until death of the child. Eight of the 14 patients died: 4 at less than 3 months of age, 3 between 3 months and 1 year of age, and 1 at 3 1/2 years of age. Six children survived for more than 2 years for follow-up examination. Survival is dependent on the level of the lesion, with cervical lesions being almost incompatible with life. The quality of survival for those with levels of C8-T1 and below depends on the child's multiple medical complications.