Development of a mapping function ("crosswalk") for the conversion of scores between the Oswestry Disability Index (ODI) and the Core Outcome Measures Index (COMI)

INTRODUCTION

The Oswestry Disability Index (ODI) and the Core Outcome Measures Index (COMI) are two commonly used self-rating outcome instruments in patients with lumbar spinal disorders. No formal crosswalk between them exists that would otherwise allow the scores of one to be interpreted in terms of the other. We aimed to create such a mapping function.

METHODS

We performed a secondary analysis of ODI and COMI data previously collected from 3324 patients (57 ± 17y; 60.3% female) at baseline and 1y after surgical or conservative treatment. Correlations between scores and Cohen's kappa for agreement (κ) regarding achievement of the minimal clinically important change (MCIC) score on each instrument (ODI, 12.8 points; COMI, 2.2 points) were calculated, and regression models were built. The latter were tested for accuracy in an independent set of registry data from 634 patients (60 ± 15y; 56.8% female).

RESULTS

All pairs of measures were significantly positively correlated (baseline, 0.73; 1y follow-up (FU), 0.84; change-scores, 0.73). MCIC for COMI was achieved in 53.9% patients and for ODI, in 52.4%, with 78% agreement on an individual basis (κ = 0.56). Standard errors for the regression slopes and intercepts were low, indicating excellent prediction at the group level, but root mean square residuals (reflecting individual error) were relatively high. ODI was predicted as COMI × 7.13-4.20 (at baseline), COMI × 6.34 + 2.67 (at FU) and COMI × 5.18 + 1.92 (for change-score); COMI was predicted as ODI × 0.075 + 3.64 (baseline), ODI × 0.113 + 0.96 (FU), and ODI × 0.102 + 1.10 (change-score). ICCs were 0.63-0.87 for derived versus actual scores.

CONCLUSION

Predictions at the group level were very good and met standards justifying the pooling of data. However, we caution against using individual values for treatment decisions, e.g. attempting to monitor patients over time, first with one instrument and then with the other, due to the lower statistical precision at the individual level. The ability to convert scores via the developed mapping function should open up more centres/registries for collaboration and facilitate the combining of data in meta-analyses.

Outcomes of a metal-on-metal total hip replacement system

INTRODUCTION

High short-term failure rates have been reported for a variety of metal-on-metal (MoM) total hip replacements (THRs) owing to adverse reactions to metal debris (ARMD). This has led to the withdrawal of certain poorly performing THRs. This study analysed the outcomes of a MoM THR system.

METHODS

Between 2004 and 2010, 578 uncemented MoM THRs (511 patients, mean age: 60.0 years) were implanted at one specialist centre. The THR system used consisted of the Corail(®) stem, Pinnacle(®) cup, Ultamet(®) liner and Articul/eze(®) femoral head (all DePuy, Leeds, UK). All patients were recalled for clinical review with imaging performed as necessary.

RESULTS

The mean follow-up duration was 5.0 years (range: 1.0-9.1 years). Overall, 39 hips (6.7%) in 38 patients (all 36 mm femoral head size) underwent revision at a mean time of 3.5 years (range: 0.01-8.3 years) from the index THR with 30 revisions (77%) performed in women. The cumulative eight-year survival rate for all THRs was 88.9% (95% confidence interval [CI]: 78.5-93.4%), with no difference (p=0.053) between male (95.2%, 95% CI: 84.2-98.7%) and female patients (85.3%, 95% CI: 70.2-92.1%) at eight years. Seventeen revisions (44%) were performed for ARMD. There was no significant difference in absolute postoperative Oxford hip scores between men and women (p=0.608). The mean acetabular inclination in unrevised THRs was 44.0°. Forty-seven non-revised THRs (8.7%) had blood metal ion concentrations above recommended thresholds (seven had periprosthetic effusions).

CONCLUSIONS

Although this MoM THR system has not failed as dramatically as other similar designs, we recommend against continued use and advise regular clinical surveillance to identify ARMD early.

The role of ultrasound in the assessment of post-operative complications following hip arthroplasty

Hip arthroplasty is one of the most commonly performed orthopedic procedures. Clinicians can be faced with the diagnostic dilemma of the patient presenting with a painful hip following arthroplasty and satisfactory post-operative radiographs. Identifying the cause of symptoms can be challenging and ultrasound is increasingly being utilized in the evaluation of potential soft tissue complications following hip surgery. In this article, we describe the common surgical approaches used during hip arthroplasty as this can influence the nature and location of subsequent complications. A review of the literature is presented along with the imaging appearances frequently encountered when imaging this patient population.

One- or two-stage bilateral metal-on-metal hip resurfacing arthroplasty

Patients considered suitable for total hip resurfacing arthroplasty often have bilateral disease. The peri-operative complications, transfusion requirements, hospital stay, outcome and costs in patients undergoing one-stage bilateral total hip resurfacing were compared with a group of patients undergoing a two-stage procedure. A total of 92 patients were included in the study, of which 37 (40%) had a one-stage and 55 (60%) had a two-stage resurfacing. There were no significant differences in age, gender, or American Society of Anaesthesiologists grade between the groups (p = 0.31, p = 0.23, p = 0.13, respectively). There were three systemic complications in the one-stage group (8.1%) and one in the two-stage group (1.8% of patients; 0.9% of procedures). There was no significant difference in the complication rate (p = 0.72) or the transfusion requirements (p = 0.32) between the two groups. The one-stage group had a reduced total hospital stay of five days (95% confidence interval 4.0 to 6.9; p < 0.001), reduced length of time to completion of all surgery of five months (95% confidence interval 2.6 to 8.3; p < 0.001), and the reduced cost was 35% less than that of a two-stage procedure. However, the total anaesthetic time was significantly longer for the one-stage group (p < 0.001; 95% confidence interval 31 to 52). This study demonstrates that consideration should be given to one-stage surgery for patients with bilateral symptomatic disease suitable for metal-on-metal hip resurfacing. A one-stage procedure appears to have benefits for both the patient and the hospital without additional complications.

Cervical intervertebral disc injury during simulated frontal impact

Cervical disc injury due to frontal impact has been observed in both clinical and biomechanical investigations; however, there is a lack of data that elucidate the mechanisms of disc injury during these collisions. The goals of the current study were to determine the peak dynamic disc annular tissue strain and disc shear strain during simulated frontal impact of the whole human cervical spine model with muscle force replication at 4 g, 6 g, 8 g and 10 g horizontal accelerations of the T1 vertebra. These data were compared with those obtained during physiological loading, and with previously reported rear impact data. Peak disc shear strain and peak annular tissue strain during frontal impact exceeded (p<0.05) corresponding physiological limits at the C2-C3 intervertebral level, beginning at 4 g and 6 g, respectively. These subsequently spread throughout the entire cervical spine at 10 g, with the exception of C4-C5. The C5-C6 intervertebral level was at high risk for injury during both frontal and rear impacts, while during frontal impact, in addition to C5-C6, subfailure injuries were likely at superior intervertebral levels, including C2-C3. The disc injuries occurred at lower impact accelerations during rear impact as compared with frontal impact. The subfailure injuries of the cervical intervertebral disc that occur during frontal impact may lead to the chronic symptoms reported by patients, such as head and neck pain.

Injury of the anterior longitudinal ligament during whiplash simulation

Anterior longitudinal ligament (ALL) injuries following whiplash have been documented both in vivo and in vitro; however, ALL strains during the whiplash trauma remain unknown. A new in vitro whiplash model and a bench-top trauma sled were used in an incremental trauma protocol to simulate whiplash at 3.5, 5, 6.5 and 8 g accelerations, and peak ALL strains were determined for each trauma. Following the final trauma, the ALLs were inspected and classified as uninjured, partially injured or completely injured. Peak strain, peak intervertebral extension and increases in flexibility parameters were compared among the three injury classification groups. Peak ALL strains were largest in the lower cervical spine, and increased with impact acceleration, reaching a maximum of 29.3% at C6-C7 at 8 g. Significant increases ( P<0.05) over the physiological strain limits first occurred at C4-C5 during the 3.5 g trauma and spread to lower intervertebral levels as impact severity increased. The complete ligament injuries were associated with greater increases in ALL strain, intervertebral extension, and flexibility parameters than were observed at uninjured intervertebral levels ( P<0.05).

Evaluation of structured and quantitative training methods for teaching intracorporeal knot tying

BACKGROUND

We evaluated the effectiveness of five training methods-four structured and one unstructured-for teaching intracorporeal knot tying.

METHODS

Forty-three graduate students without prior laparoscopic experience were randomly assigned to one of five training groups, and their performance in 10 intracorporeal knot tying trials was evaluated, using time to complete a knot as the outcome measure.

RESULTS

The average knot tying times for the four structured groups were significantly faster than the unstructured group (p < 0.0001). Among the four structured groups, the minimally invasive surgical trainer-virtually reality (MIST-VR) and the box trainer drills showed the most rapid improvements. The MIST-VR improved average suturing time from trial one to trial two (P = 0.05), the box trainer drills group improved from trial one to trial four (P = 0.01), and the other two groups showed slower improvements. Statistically significant correlations were observed between scores on MIST-VR tasks and average knottying times (R > 0.7, p < 0.05).

CONCLUSION

Structured training can be useful for the development of laparoscopic skills. MIST-VR is a valuable part of this training, particularly in the objective evaluation of performance.

Scavenger receptors in innate immunity

Scavenger receptors are cell-surface proteins expressed by mammalian monocytes and macrophages and by invertebrate hemocytes, among other cell types. They exhibit distinctive ligand-binding properties, recognizing a wide range of ligands that include microbial surface constituents and intact microbes. The ligand-binding properties and expression patterns of these receptors suggest that they may function in one or more host-defense-related processes. Significant advances in scavenger receptor biology have recently been reported, including the identification of several new scavenger receptor genes.

Control of the dehydration process in production of intermediate-moisture meat products: a review

IM meat products are produced by lowering the aw to 0.90 to 0.60. Such products are stable at ambient temperature and humidity and are produced in nearly every country in the world, especially in developing areas where refrigeration is limited or unavailable. Traditionally IM meats use low cost sources of energy for drying, such as sun drying, addition of salt, or fermentation. Products produced by different processes are of interest since they do not require refrigeration during distribution and storage. Many different IM meat products can be produced by utilizing modern processing equipment and methods. Production can be achieved in a relatively short period of time and their advantages during marketing and distribution can be utilized. Nevertheless, a better understanding of the principles involved in heat transfer and efficiency of production are still needed to increase efficiency of processing. A basic understanding of the influence of water vapor pressure and sorption phenomena on water activity can materially improve the efficiency of drying of IM meats. Predrying treatments, such as fermentation and humidity control, can also be taken advantage of during the dehydration process. Such information can lead to process optimization and reduction of energy costs during production of IM meats. The development of sound science-based methods to assure the production of high-quality and nutritious IM meats is needed. Finally, such products also must be free of pathogenic microorganisms to assure their success in production and marketing.

Polynucleotide binding to macrophage scavenger receptors depends on the formation of base-quartet-stabilized four-stranded helices

Macrophage scavenger receptors exhibit unusually broad, but circumscribed, polyanionic ligand-binding specificity. For example, the polyribonucleotides poly(I) and poly(G) are ligands but poly(A) and poly(C) are not. To further investigate the molecular basis of this polynucleotide-binding specificity, we tested the capacity of various oligodeoxyribonucleic acids to inhibit the scavenger receptor-mediated degradation of 125I-labeled acetylated low density lipoprotein by Chinese hamster ovary cells expressing the type I bovine scavenger receptor. A series of short oligodeoxyriboguanines (dGn, where 5 < or = n < or = 37) were effective inhibitors. The dG6, dG12, and dA5G37 members of this series were shown by circular dichroism and UV spectroscopy to be assembled into four-stranded helices stabilized by G-quartets. [32P]dA5G37 bound directly to scavenger receptors. Partial or complete denaturation of the quadruplex structures of these oligonucleotides by boiling destroyed their inhibitory activity. Receptor activity was also inhibited by d(T4G4)4, a telomere-like oligonucleotide which forms an intramolecular quadruplex. In addition, conversion of the four-stranded potassium salt of poly(I) to the single-stranded lithium salt dramatically reduced its inhibitory activity. Addition of KCl to the Li+ salt resulted in the reformation of poly(I)'s quadruplex structure and restoration of its inhibitory activity. A variety of single-stranded and double-stranded oligo- and polydeoxyribonucleotides (e.g. dA37, HaeIII restriction fragments of phi X174) exhibited very little or no inhibitory activity. Thus, a base-quartet-stabilized four-stranded helix appears to be a necessary structural determinant for polynucleotide binding to and inhibition of scavenger receptors. This conformational requirement accounts for the previously unexplained polyribonucleotide-binding specificity of scavenger receptors. The spatial distribution of the negatively charged phosphates in polynucleotide quadruplexes may form a charged surface which is complementary to the positively charged surface of the collagenous ligand-binding domain of the scavenger receptor.

Diseases and disorders of muscle

Muscle may suffer from a number of diseases or disorders, some being fatal to humans and animals. Their management or treatment depends on correct diagnosis. Although no single method may be used to identify all diseases, recognition depends on the following diagnostic procedures: (1) history and clinical examination, (2) blood biochemistry, (3) electromyography, (4) muscle biopsy, (5) nuclear magnetic resonance, (6) measurement of muscle cross-sectional area, (7) tests of muscle function, (8) provocation tests, and (9) studies on protein turnover. One or all of these procedures may prove helpful in diagnosis, but even then identification of the disorder may not be possible. Nevertheless, each of these procedures can provide useful information. Among the most common diseases in muscle are the muscular dystrophies, in which the newly identified muscle protein dystrophin is either absent or present at less than normal amounts in both Duchenne and Becker's muscular dystrophy. Although the identification of dystrophin represents a major breakthrough, treatment has not progressed to the experimental stage. Other major diseases of muscle include the inflammatory myopathies and neuropathies. Atrophy and hypertrophy of muscle and the relationship of aging, exercise, and fatigue all add to our understanding of the behavior of normal and abnormal muscle. Some other interesting related diseases and disorders of muscle include myasthenia gravis, muscular dysgenesis, and myclonus. Disorders of energy metabolism include those caused by abnormal glycolysis (Von Gierke's, Pompe's, Cori-Forbes, Andersen's, McArdle's, Hers', and Tauri's diseases) and by the acquired diseases of glycolysis (disorders of mitochondrial oxidation). Still other diseases associated with abnormal energy metabolism include lipid-related disorders (carnitine and carnitine palmitoyl-transferase deficiencies) and myotonic syndromes (myotonia congenita, paramyotonia congenita, hypokalemic and hyperkalemic periodic paralysis, and malignant hyperexia). Diseases of the connective tissues discussed include those of nutritional origin (scurvy, lathyrism, starvation, and protein deficiency), the genetic diseases (dermatosparaxis, Ehlers-Danlos syndrome, osteogenesis imperfecta, Marfan syndrome, homocystinuria, alcaptonuria, epidermolysis bullosa, rheumatoid arthritis in humans, polyarthritis in swine, Aleutian disease of mink, and the several types of systemic lupus erythematosus) and the acquired diseases of connective tissues (abnormal calcification, systemic sclerosis, interstitial lung disease, hepatic fibrosis, and carcinomas of the connective tissues). Several of the diseases of connective tissues may prove to be useful models for determining the relationship of collagen to meat tenderness and its other physical properties. Several other promising models for studying the nutrition-related disorders and the quality-related characteristics of meat are also reviewed.

Mechanism(s) involved in meat mutagen formation and inhibition

The Maillard reaction, which involves Amadori rearrangement as a key step, also results in sugar fragmentation and free radical formation. The imidazoquinoline meat mutagens (2-amino-3-methylimidazo[4,5-f]-quinoline, or IQ, and 2-amino-3,4-dimethylimidazo[4,5-f]quinoline, or MeIQ) are formed from a reaction mixture containing alkylpyridine free radicals and creatinine. The imidazoquinoxaline meat mutagens (2-amino-3,4-dimethylimidazo[4,5-f]-quinoxaline, or MeIQx, and 2-amino-3,4,8-trimethylimidazo[4,5-f]-quinoxaline, or 4,8-DiMeIQx) may be produced by reacting a mixture containing dialkylpyrazine free radicals and creatinine. Two different pathways for free radical formation are proposed. One involves bimolecular ring formation from the enaminol form of the glycoaldehyde alkylimine and is followed by oxidative formation of the free radical. The other pathway involves formation of N,N1-dialkylpyrazinium ions from glyoxal monoalkylimine followed by reduction to produce the free radicals. The respective intermediates (glycoaldehyde alkylimine and glyoxal monoalkylamine) are formed by reacting glycoaldehyde and glyoxal with amino compounds. The glycoaldehyde system reacts faster and produces more free radicals than the glyoxal system. The reactions help to explain the formation of imidazoquinoxaline meat mutagens and their predominance in fried fish and why these mutagens are present in larger quantities in fried ground beef than the imidazoquinoline-type meat mutagens. These two pathways may not be the only mechanisms involved in formation of meat mutagens, but other free radical reactions may also contribute to meat mutagenicity and are mentioned briefly.(ABSTRACT TRUNCATED AT 250 WORDS)

Muscle growth and exercise

This paper first reviews muscle growth and then considers the influence of exercise in growth. Knowledge about how muscle cells grow and some factors that may influence the growth pattern are discussed first since these effects must be considered before the influence of exercise becomes clear. Growth of muscle can occur in three ways: (1) by an increase in muscle cell numbers, (2) by an increase in muscle fiber diameter, and (3) by an increase in fiber length. All three of these mechanisms are involved in muscle growth. However, growth in cell numbers is limited to the prenatal and immediately postnatal period, with the animals and man being born with or soon reaching their full complement of muscle cells. Thus, growth occurs by either hypertrophy of the existing muscle fibers by adding additional myofibrils to increase the muscle mass or by adding new sarcomeres to the ends of the existing muscle fibers to increase their length. Both of these mechanisms occur during the growth process. Growth in the girth of the muscle fibers appears to take place by splitting of the myofibrils. This may be stimulated by development of stress creating an unequal pressure with splitting at the Z-band and development of additional SR and T-tubule systems. This adds to the diameter or girth of myofibers without any hyperplasia. The growth in length occurs at either end of the fibers and results in addition of new sarcomeres. In both cases, new myofibrillar protein must be synthesized and deposited in the muscle cells. It is suggested that adaptation by adding or removing sarcomeres is physiologically determined by the degree of force a muscle can generate that is in turn dependent on the degree of overlap of the thick and thin filaments. Thus, the amount of tension would control the number of in-series sarcomeres in a single muscle fiber. Nutrition is also known to play an important role in muscle and was discussed from the standpoint of the effects of nutritional adequacy and restriction. Although a nutritionally balanced and calorically adequate diet is required to achieve optimum muscle growth, it may be less efficient in terms of protein deposition than a moderately restricted diet. Muscle and bone deposition, however, can be limited on severely restricting the dietary intake. Although fat deposition is the first tissue to suffer on a severely restricted diet, muscle and bone follow next with the nervous system, brain and eyes being the last systems to be affected.(ABSTRACT TRUNCATED AT 400 WORDS)

The handwriting of children with spina bifida

As part of the Greater London Council (GLC) Spina Bifida Survey the handwriting of 131 11-year-olds with spina bifida and 56 controls was examined. The children copied the sentence "The dog sits in his box" in the course of an extensive battery of intelligence and attainment tests. Writing speed formed one scoring dimension and nine further categories were devised in collaboration with a handwriting consultant. All but one of these ten dimensions consistently discriminated between the spina bifida children and the controls, and between the spina bifida children divided according to such variables as IQ, school type, degree of disability, reading scores and presence or absence of a valve. In every case the differences were in the predicted direction, with the handwriting scores of the brighter, less damaged children, and those attending ordinary schools being higher. These findings are consistent with those obtained by other researchers and reflect an educational disadvantage in that the children with spina bifida had handwriting which was slow, with the letters being poorly formed and the words poorly spaced.

Contribution of wood smoke to in vivo formation of N-nitrosothiazolidine-4-carboxylic acid: initial studies

The effect of administering liquid smoke or smoked food products to rats on in vivo formation of N-nitrosamino acids was investigated. Rats treated by gavage with either cysteine, formaldehyde or nitrite excreted urine containing no detectable levels of N-nitrosothiazolidine-4-carboxylic acid (NTCA). All three precursor compounds were required for NTCA formation. Two liquid smokes, when administered to rats in combination with cysteine and nitrite also produced measurable quantities of NTCA. Ascorbate inhibited in vivo formation of NTCA by approximately 90% when given to rats simultaneously with cysteine, formaldehyde, and nitrite. alpha-Tocopherol was much less effective than ascorbate in blocking NTCA formation. When smoked bacon, smoked Swiss cheese, and chicken barbecued with a sauce containing smoke flavouring were fed to rats along with nitrate, NTCA was again detected in the urine.

Steroid hormone pathways in the pig, with special emphasis on boar odor: a review

Although castration of male pigs grown for meat production has long been a commercial practice in order to eliminate an undesirable odor emanating from the meat upon heating, intact males (boars) grow faster, utilize feed more efficiently and produce leaner carcasses. This review outlines the biochemical pathways of steroid hormone formation in the pig, placing special emphasis on the C19-delta 16-steroids, which have been shown to produce the "urine- or perspiration-like" odor of boar meat. Analytical methods currently available for quantitation of the C19-delta 16-steroids are also reviewed, including gas chromatography-mass spectrometry, radioimmunoassays and enzyme-linked-immuno-absorbent-assays (ELISA). Finally, methods for preventing boar odor are discussed, such as environmental methods of rearing boars, genetic selection against boar odor and autoimmunization against C19-delta 16-steroids. Autoimmunization techniques appear to offer the most promise for inhibiting production of the compounds responsible for boar odor in male pigs raised for meat production, while still maintaining the advantages of improved efficiency and greater leanness.

Aflatoxin carryover and clearance from tissues of laying hens

A feeding trial was conducted to determine the levels of aflatoxins deposited in the tissues of hens fed a diet contaminated with 3310 micrograms AFB1/kg and 1680 micrograms AFB2/kg for 4 wk. At the end of aflatoxin feeding, the livers were pale, enlarged and haemorrhagic and the ovaries were significantly smaller than those from control hens and contained only small ova. Only a small fraction of the aflatoxins consumed was deposited in the tissues, either as the original compounds or as their metabolites, which were widely distributed in all tissues. The highest levels of aflatoxins were detected in the gizzard, kidneys and liver, with average total concentrations of less than 3 micrograms/kg. The lowest residue levels were detected in the breast, blood serum and leg, with breast muscle having a total concentration of less than 0.1 microgram/kg. Two days after removal of the contaminated feed, aflatoxin residues in all tissues had decreased markedly, with no aflatoxins being detected in the heart or spleen. No aflatoxin residues were detected in the breast, leg, gizzard and ovaries of hens killed 8 days after withdrawal, or in the kidneys and blood at 16 days. However, one of seven hens had measurable amounts of AFB2 in the liver 32 days after withdrawal. Although few residues were detected in most tissues after 8 days on the aflatoxin-free diet, variation existed between tissues and between individual hens in the amount of time required to achieve tissue clearance.

Aflatoxin deposition and clearance in the eggs of laying hens

Hens fed a diet containing 3310 micrograms of AFB1 and 1680 micrograms of AFB2 per kg feed for 28 days showed a significant decrease in egg production and egg weights by wk 3 and 4 of feeding, respectively. Transfer of aflatoxins to the eggs occurred rapidly, reaching maximum levels after 4-5 days, and remained relatively constant throughout aflatoxin feeding. The mean values for combined residue levels in eggs were less than 0.5 microgram/kg. Levels of AFB2, AFM1 and AFM2 were similar in yolk and albumen while levels of B1 and B2a were higher in the yolk. Upon removal of the aflatoxin-containing diet, residues in eggs decreased rapidly. Clearance of aflatoxin residues from the albumen occurred faster than from the yolk. Thus, no residues were detected in the albumen and in the yolk after 5 and 7 days of withdrawal, respectively. No aflatoxin residues could be recovered from whole eggs after feeding the aflatoxin-free diet for 4 days.

Broiler aflatoxicosis with recovery after replacement of the contaminated diet

Broiler chickens were fed a diet containing 2057 and 1323 micrograms/kg feed of aflatoxins B1 and B2, respectively, for 35 d. Effects of aflatoxins on growth, food consumption, efficiency of food utilisation and manifestations of aflatoxicosis were compared with control birds at the end of the feeding trial and at 1, 2, 4, 8 and 16 d after replacing the contaminated feed. No difference in food consumption was observed between the controls and the aflatoxin-fed chickens, but efficiency of food utilisation was decreased from 2.2 for the controls to 2.4 g food/g gain for the group fed aflatoxins. Aflatoxins caused depressed growth and enlargement of the kidney, liver, heart and gall bladder. Haemorrhagic spots were present on the surface of the muscles and some of the livers. Most livers from aflatoxin-fed birds were pale and infiltrated with lipid. After withdrawal of the food containing aflatoxins, all apparent gross lesions of aflatoxicosis disappeared, with no evidence of any lesions 8 d after removal of the contaminated diet.

Tissue deposition and clearance of aflatoxins from broiler chickens fed a contaminated diet

A study was conducted to determine aflatoxin levels in the tissues of broiler chickens that had been fed a diet containing 2057 micrograms aflatoxin B1 and 1323 micrograms aflatoxin B2/kg for 35 days. Results showed that aflatoxins were deposited in all tissues. The highest levels of aflatoxins were present in the gizzards, livers and kidneys. There was evidence that the high levels of aflatoxins B1 and B2 in the gizzards might have been caused by contamination by the gizzard contents during the slaughtering process. After feeding the aflatoxin-contaminated diet for 35 days, mean values for the combined aflatoxins were less than 3 micrograms/kg of tissue. Four days after withdrawal of the aflatoxin-contaminated ration, there were no detectable amounts of aflatoxins in any of the tissues. The results indicate that broiler chickens rapidly clear aflatoxins from their tissues once they are transferred to an aflatoxin-free diet.

Salt-its use in animal products- a human health dilemma

High Na intake has been identified as one possible contributor to development of hypertension that occurs in 10 to 20% of the United States population. Per capita intake of salt, which is the major source of Na in the diet, is estimated to average 10 to 12 g/d. Discretionary use accounts for about 3 to 4 g, with an equal amount naturally present in unprocessed foods and 4 to 6 g being added during processing. Theories concerning the possible role of salt in development of hypertension are reviewed. As a result of the possible relationship of salt intake to hypertension, the Food and Nutrition Board has recommended that salt consumption be reduced to 3 to 8 g.capita-1.d-1. This would require a reduction in the amount of salt added by discretionary use and (or) during processing. The amount of salt found in various raw and processed animal products is presented and the role and importance of salt in these products are examined. Consideration is then given to methods that may be adopted to reduce Na consumption and the potential influence of these methods upon various animal products.

Educational attainments of spina bifida children attending ordinary or special schools

Children with spina bifida who attend special schools are usually found to be retarded in their school attainment compared with those who attend ordinary schools. This finding has, however, often been confounded by the fact that the special school children tend to have lower IQs. In this study two groups of children were identified from those in the Greater London Council (GLC) Spina Bifida Survey, one attending ordinary and the other special schools. There were 11 pairs of boys and 11 of girls, each pair being closely matched for IQ. Examination of their scores on attainment tests showed that while results of reading tests did not differ significantly between the two types of schools, children of both sexes at special schools were behind their ordinary school counterparts in number work. These results were supported by similar findings, using analysis of co-variance, on the larger group of children in the GLC survey. The effect of other factors such as physical handicap, presence of a valve, and time spent in hospital, were explored, and possible explanations for the findings are discussed.

Effects of ad libitum, maintenance and sub-maintenance feeding and of compensatory growth on some biochemical properties of muscle from weanling rabbits

Weanling male rabbits were fed either: 1) a complete diet ad libitum (control); 2) a maintenance diet; or 3) a sub-maintenance diet. After 20 days, half of each group was slaughtered and the remainder was placed on treatment 1 until they achieved the same body weights as the controls (about 30 more days), when they were also killed. Body organs, including livers, hearts, lungs and kidneys, were significantly reduced in weight by nutritional stress. Maintenance and sub-maintenance feeding resulted in creases in ultimate muscle pH, water content and alkali-soluble and -insoluble stromal proteins. The intracellular proteins, especially the myofibrillar fraction, decreased markedly, depending on the degree of nutritional stress. Swelling of the stromal proteins was less for the underfed rabbits, indicating that nutritional stress increased the number of acid-stable corss-linkages. Calcium-induced contraction was not effected by any of the nutritional treatments. Blood enzymes were not affected by nutritional stress from the standpoint of their multiple molecular forms, mobility or band profiles. All differences in muscle characteristics disappeared during compensatory growth except for the increased amount of alkali-insoluble stroma protein. The concepts of labile, mobilizable and fixed body proteins are discussed.

Role of Nitrite in Cured Meat Flavor: A Review

Little is known about the mechanism of the reactions leading to formation of cured meat flavor or of the identity of volatile and non-volatile substances responsible for it. This review of the contribution of nitrite to cured meat flavor in products such as ham, bacon and frankfurters includes sensory analyses and studies of the chemical components contributing to cured meat flavor. The antioxidant properties of nitrite in retarding development of warmed-over flavor in cured meats are also discussed.

Improved resolution of myofibrillar proteins with sodium dodecyl sulfate-polyacrylamide gel electrophoresis

Standard experimental procedures for continuous polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate were modified to give more effective separation and improved resolution of myofibrillar proteins. The system utilizes a running gel consisting of 10% acrylamide with 0.1% bisacrylamide crosslinker (100:1) incorporating 400 mM Tris/glycine (pH 8.80), 0.1 mM ethylenediaminetetraacetate, 5% glycerol and 0.1% sodium dodecyl sulfate. Electrophoresis was performed at 1 mA per gel with corresponding running times of 4-6 h. The myosin heavy chain enters and migrates as a narrow symmetrical band while the smaller regulatory proteins of the myofibril are resolved. The utility of the procedure in relation to the study of protein structure is detailed.

Some factors that may alter consumption of animal products. A review

Trends in consumption of animal products are discussed, including reasons for changes. Although consumption of some products has increased--notably that of broilers and beef--for other products, it has declined, i.e., total dairy products and eggs. Evidence shows that consumers desire a lower fat content in both meat and dairy products, although, in the case of meat, minimal levels are necessary for palatability. Overall, it is suggested that consumers are concerned with nutritional quality and are influenced by health-related concerns. The use of vegetable proteins as extenders and substitutes for animal proteins is reviewed, with the conclusion that they will continue to influence consumption of animal products.

Isolation of an extracellular neutral proteinase from Pseudomonas fragi

A single proteolytic enzyme (EC 3.4.4.-) was isolated from culture supernatants of Pseudomonas fragi with 20% yielded and 60-fold purification by means of stepwise DEAE-Sephadex batch adsorption, ammonium sulfate precipitation, gel filtration and DEAE-cellulose chromatography. The enzyme was Zn-2+ activated and Ca-2+ stabilized, had optimum activity at pH 6.5--8.0 and 40 degrees C. The molecular weight range was 40 000--50 000 as determined by dodecylsulfate gel electrophoresis, gel filtration and Zn assay. This proteinase has properties similar to other extracellular bacterial neutral proteinases.

Helminths of wolves, Canis lupus L., in the Yukon and Northwest Territories

Wolves from the Yukon and Northwest Territories harbored the following gastrointestinal helminths: Alaria americana (10 of 171), A. arisaemoides (2/171), Diphyllobothrium sp, (1/171). Mesocestoidcs kirbyi (3/171), Taenia hydatigena (54/111), T. krabbei (63/111), T. pisiformis (2/111), T. serialis (41/111), Echinococcus granulosus (24/171), Toxascaris leonina (83/171). Uncinaria stenocephala (11/171), Spirocerca arctica (1/171), and S. lupi (1/171). Larval Trichinella spiralis occurred in 72 of 153 diaphragms. A. arisaemoides, M. kirbyi, and S. arctica were found for the first time in Canis lupus, while S. lupi, S. arctica, and the prevalence of T. spiralis in wolves are reported for the first time in Canada.

Proteolytic enzyme preparation from Pseudomonas fragi: its action on pig muscle

An extracellular preparation from Pseudomonas fragi with proteolytic enzyme activity was isolated, and its action on meat proteins and meat protein ultrastructure was studied. First, a suitable growth medium for proteolytic enzyme production was determined, and a method for partial purification of the proteolytically active fraction was developed. The enzyme preparation displayed optimal proteolytic activity at neutral pH and 35 C. Proteolytic activity was irreversibly lost by mild heat treatment. The enzyme preparation was tested for its ability to hydrolyze isolated pig muscle proteins. Myofibrillar protein was rapidly degraded, G-actin and myosin were broken down at a slower rate, and the sarcoplasmic proteins were least susceptible to hydrolysis. Electron micrographs of pork muscle showed that the proteolytic enzyme preparation caused a complete loss of dense material from the Z line. Similarities are discussed between the action of P. fragi extracellular proteolytic enzyme(s) on meat and normal bacterial spoilage of meat.

Blood chemistry of the brown bear (Ursus arctos) from southwestern Yukon Territory, Canada

Blood samples from 22 brown bears (Ursus arctos) were assayed for calcium, phosphorus, glucose, urea, creatinine, uric acid, cholesterol, total protein, albumin, total bilirubin, alkaline phosphatase, lactic dehydrogenase, glutamic–oxaloacetic acid transaminase, sodium, potassium, and chloride.Statistically significant seasonal changes in brown bears included a spring-to-summer decrease of calcium, urea, creatinine, and uric acid and concurrent increases of glucose and potassium. These changes may be related to renal function and seasonal variations in the bear's diet. The only sexual difference was the higher uric acid levels in male brown bears than in females.The blood chemistry of four black bears (Ursus americanus) was similar to that of brown bears except for slightly higher levels of phosphorus, creatinine, uric acid, glutamic–oxaloacetic acid transaminase, sodium, and chloride. Our limited sample of black bears did not allow an investigation of seasonal changes.