Sire breed effect on beef longissimus mineral concentrations and their relationships with carcass and palatability traits

The objective of this study was to evaluate sire breed effect on mineral concentration in beef longissimus thoracis (LT) and investigate the correlations between beef mineral concentrations and carcass and palatability traits. Steer progeny (N=246) from the Germplasm Evaluation project-Cycle VIII were used in this study. In addition to carcass traits, LT was evaluated for mineral concentrations, Warner-Bratzler shear force, and palatability traits. A mixed linear model estimated breed effects on mineral concentrations. No significant sire breed (P≥0.43) or dam breed (P≥0.20) effects were identified for mineral concentrations. Pearson correlation coefficients were calculated among mineral concentrations, carcass, and sensory traits. Zinc concentration was positively correlated (P≤0.05) with total iron (r=0.14), heme iron (r=0.13), and magnesium (r=0.19). Significant (P<0.05) correlations were identified between non-heme or heme iron and most traits in this study. Magnesium concentration was correlated with all carcass and palatability traits.

Polymorphisms in calpastatin and mu-calpain genes are associated with beef iron content

The objective of this study was to assess the association of markers in the calpastatin and mu-calpain loci with iron in beef cattle muscle. The population consisted of 259 cross-bred steers from Beefmaster, Brangus, Bonsmara, Romosinuano, Hereford and Angus sires. Total iron and heme iron concentrations were measured. Markers in the calpastatin (referred to as CAST) and mu-calpain (referred to as CAPN4751) genes were used to assess their association with iron levels. The mean and standard error for iron and heme iron content in the population was 35.6 ± 1.3 μg and 27.1 ± 1.4 μg respectively. Significant associations (P < 0.01) of markers were observed for both iron and heme iron content. For CAST, animals with the CC genotype had higher levels of iron and heme iron in longissimus dorsi muscle. For CAPN4751, individuals with the TT genotype had higher concentrations of iron and heme iron than did animals with the CC and CT genotypes. Genotypes known to be associated with tougher meat were associated with higher levels of iron concentration.

The high-energy light action controlling plant responses and development

Evidence is advanced for a network of three photoreactions and five dark reactions in control of plant growth and development by phytochrome.

Evaluation of fixed sources of variation and estimation of genetic parameters for incidence of bovine respiratory disease in preweaned calves and feedlot cattle

The primary objective of this study was to estimate variance components and heritability of bovine respiratory disease (BRD) incidence in beef calves before weaning and during the finishing phase. The second objective was to investigate the impact of BRD incidence and treatment frequency on performance and carcass traits. Bovine respiratory disease is the biggest and most costly health challenge facing the cattle industry. The 2 populations used consisted of 1,519 preweaned calves and 3,277 head of feedlot cattle. The incidence rate of BRD in preweaned calves was 11.39%, and among treated cattle, 82.1% were treated once, 13.9% were treated twice, and 4.0% were treated 3 times or more. The incidence of BRD (P = 0.35) and the number of treatments (P = 0.77) had no significant effect on weaning BW. Heritability estimates of the entire preweaned population for BRD resistance and number of treatments were 0.11 +/- 0.06 and 0.08 +/- 0.05, respectively. The genetic correlation estimates for BRD incidence with weaning BW and birth BW were low (-0.02 +/- 0.32 and 0.07 +/- 0.27, respectively). The same estimate for the number of BRD treatments with weaning BW and birth BW was 0.25 +/- 0.35 and 0.30 +/- 0.27, respectively. The observed BRD incidence rate for feedlot cattle was observed at 9.43%. Incidence of BRD significantly (P < 0.01) decreased overall and acclimation ADG by 0.06 +/- 0.01 kg/d and 0.28 +/- 0.03 kg/d, respectively. Carcass traits were also significantly (P < 0.05) affected by BRD incidence; untreated cattle had a 9.1 +/- 1.7-kg heavier HCW. Results were similar in the analysis of treatment frequency. The heritability estimate of BRD incidence and the number of treatments were 0.07 +/- 0.04 and 0.02 +/- 0.03, respectively. Estimates of genetic correlations of BRD incidence with production traits were -0.63 +/- 0.22 for acclimation ADG, -0.04 +/- 0.23 for on-test ADG, -0.31 +/- 0.21 for overall ADG, -0.39 +/- 0.21 for final BW, -0.22 +/- 0.22 for HCW, -0.03 +/- 0.22 for LM area, 0.24 +/- 0.25 for fat, and -0.43 +/- 0.20 for marbling score. Similar results for the number of treatments and production traits were -1.00 +/- 0.68 for acclimation ADG, -0.04 +/- 0.39 for on-test ADG, -0.47 +/- 0.41 for overall ADG, -0.66 +/- 0.40 for final BW, -0.58 +/- 0.45 for HCW, -0.12 +/- 0.38 for LM area, 0.42 +/- 0.50 for fat, and -0.32 +/- 0.37 for marbling score. Because of the high economic cost associated with BRD incidence, even these modest estimates for heritability of BRD resistance should be considered for incorporation into beef cattle breeding programs.

An evaluation of bovine respiratory disease complex in feedlot cattle: Impact on performance and carcass traits using treatment records and lung lesion scores

The objective of this study was to investigate the effects of bovine respiratory disease (BRD) complex on economically important production traits with the use of health records in combination with lung lesion scores obtained at slaughter. Records from 5,976 animals were used in this study from cattle that were managed in Midwestern feedlots. Average daily gain for 3 different feeding periods (acclimation, on-test, and overall test) along with final BW were evaluated as performance measures. Hot carcass weight, LM area, subcutaneous fat cover, and marbling score were collected at slaughter. All calves were monitored by experienced feedlot personnel and treated according to the specific health protocol of each feedlot. Incidence of BRD was observed at a rate of 8.17%, and lung lesions at slaughter were present in 61.9% of cattle from a subpopulation (n = 1,665). From this group of cattle, the overall incidence of BRD, which was defined as cattle that had lung lesions, that were treated for BRD in the feedlot, or both, was 64.4%. Incidence of BRD in the feedlot decreased ADG during both the acclimation period (0.37 +/- 0.03 kg) and the overall test period (0.07 +/- 0.01 kg). Incidence of BRD also had significant effects on HCW and marbling score with reduction of 8.16 +/- 1.38 kg and 0.13 +/- 0.04, respectively, in treated cattle. The adverse effects on production traits tended to increase as the number of treatments increased. Potential decrease in performance and carcass merit observed in this study were associated with a decline of $23.23, $30.15, and $54.01 in carcass value when comparing cattle never treated with cattle treated once, twice, or 3 or more times, respectively. The presence of lung lesions did not have a significant effect on any of the traits; however, there was an association between the presence of active bronchial lymph nodes and less productivity of feedlot cattle.

Comparison of a bioassay and a liquid chromatography-fluorescence-mass spectrometry(n) method for the detection of incurred enrofloxacin residues in chicken tissues

Regulatory monitoring for most antibiotic residues in edible poultry tissues is often accomplished with accurate, although expensive and technically demanding, chemical analytical techniques. The purpose of this study is to determine if a simple, inexpensive bioassay could detect fluoroquinolone (FQ) residues in chicken muscle above the FDA established tolerance (300 ppb) comparable to a liquid chromatography-fluorescencemass spectrometry(n) method. To produce incurred enrofloxacin (ENRO) tissues (where ENRO is incorporated into complex tissue matrices) for the method comparison, 40-d-old broilers (mixed sex) were orally dosed through drinking water for 3 d at the FDA-approved dose of ENRO (50 ppm). At the end of each day of the 3-d dosing period and for 3 d postdosing, birds were sacrificed and breast and thigh muscle collected and analyzed. Both methods were able to detect ENRO at and below the tolerance level in the muscle, with limits of detection of 26 ppb (bioassay), 0.1 ppb for ENRO, and 0.5 ppb for the ENRO metabolite, ciprofloxacin (liquid chromatography-fluorescence-mass spectrometry(n)). All samples that had violative levels of antibiotic were detected by the bioassay. These results support the use of this bioassay as a screening method for examining large numbers of samples for regulatory monitoring. Positive samples should then be examined by a more extensive method, such as liquid chromatography-fluorescence-mass spectrometry(n), to provide confirmation of the analyte.

Targeted disruption of the type 2 selenodeiodinase gene (DIO2) results in a phenotype of pituitary resistance to T4

The type 2 deiodinase (D2), a selenoenzyme that catalyzes the conversion of T4 to T3 via 5'-deiodination, is expressed in the pituitary, brain, brown adipose tissue (BAT), and the reproductive tract. To examine the physiological role of this enzyme, a mouse strain lacking D2 activity was developed using homologous recombination. The targeting vector contained the Neo gene in place of a 2.6-kb segment of the Dio2 gene. This segment comprises 72% of the coding region and includes the TGA codon that codes for the selenocysteine located at the active site of the enzyme. Mice homologous for the targeted deletion [D2 knockout (D2KO)] had no gross phenotypic abnormalities, and development and reproductive function appeared normal, except for mild growth retardation (9%) in males. No D2 activity was observed in any tissue in D2KO mice under basal conditions, or under those that normally induce this enzyme such as cold-exposure (BAT) or hypothyroidism (brain, BAT, and pituitary gland). Furthermore, no D2 activity was present in cultured astrocytes, nor could it be induced by treatment of the cells with forskolin. Although D2 mRNA transcripts were detected in BAT RNA obtained from cold-exposed wild-type (WT) mice, none was detected in BAT RNA from comparably-treated D2KO mice. Levels of D1 in the liver, thyroid, and pituitary were the same in WT and D2KO animals, whereas D3 activity in D2KO cerebrum was twice that in WT cerebrum. Serum T3 levels were comparable in adult WT and D2KO mice. However, serum T4 and TSH levels were both elevated significantly (40% and 100%, respectively) in the D2KO mice, suggesting that the pituitary gland of the D2KO mouse is resistant to the feedback effect of plasma T4. This view was substantiated by the finding that serum TSH levels in hypothyroid WT mice were suppressed by administration of either T4 or T3, but only T3 was effective in the D2KO mouse. The data also suggest that the clearance of T4 from plasma was reduced in the D2KO mouse. In summary, targeted inactivation of the selenodeiodinase Dio2 gene results in the complete loss of D2 activity in all tissues examined. The increased serum levels of T4 and TSH observed in D2KO animals demonstrate that the D2 is of critical importance in the feedback regulation of TSH secretion.

Rating specific chiropractic technique procedures for common low back conditions

OBJECTIVE

To rate specific chiropractic technique procedures used in the treatment of common low back conditions.

DESIGN AND METHODS

A panel of chiropractors rated specific chiropractic technique procedures for their effectiveness in the treatment of common low back conditions, based on the quality of supporting evidence after systematic literature reviews and expert clinical opinion. Statements related to the rating process and clinical practice were then developed through a facilitated nominal consensus process.

RESULTS

For most low back conditions presented in this study, the three procedures rated most effective were high-velocity, low- amplitude (HVLA) with no drop table (side posture), distraction technique, and HVLA prone with drop table assist. The three rated least effective were upper cervical technique, non-thrust reflex/low force, and lower extremity adjusting. The four conditions rated most amenable to chiropractic treatment were noncomplicated low back pain, sacroiliac joint dysfunction, posterior joint/subluxation, and low back pain with buttock or leg pain.

CONCLUSIONS

The ratings for the effectiveness of chiropractic technique procedures for the treatment of common low back conditions are not equal. Those procedures rated highest are supported by the highest quality of literature. Much more evidence is necessary for chiropractors to understand which procedures maximally benefit patients for which conditions.

Multiresidue analysis of fluoroquinolone antibiotics in chicken tissue using automated microdialysis-liquid chromatography

An efficient procedure for the simultaneous extraction and analysis of six fluoroquinolone (FQ) antibiotics is developed using an automated microdialysis-liquid chromatographic (LC) system. In this method, samples extracted from chicken liver and muscle are further purified by microdialysis, separated on an LC column, and the FQs detected by their fluorescence. Recoveries from fortified chicken liver and muscle samples are at least 70% with limits of quantitation (microg/kg) for the FQs in liver (and muscle) as follows: 0.3 (0.4) for danofloxacin, 0.8 (0.2) for desethylene ciprofloxacin, 2 (1) for norfloxacin, 2 (0.8) for enrofloxacin, 3 (1) for ciprofloxacin, and 5 (2) for sarafloxacin. Enrofloxacin and ciprofloxacin are determined in enrofloxacin-incurred chicken liver and muscle samples using this method.

Chiropractic technique procedures for specific low back conditions: characterizing the literature

BACKGROUND

Many original clinical trials and several review papers have come to the conclusion that manipulation is safe and effective for the treatment of low back pain. However, it is necessary to determine which specific types of manipulation and nonmanipulative types of chiropractic adjustive care are most effective for particular types of low back pain across both tissue-specific and functional classifications.

OBJECTIVE

To characterize the quantity and quality of literature gathered for an Expert Panel that was convened to rate various specific chiropractic adjustive procedures for the treatment of common types of low back pain, drawing on the clinical expertise of the panel members and the relevant literature.

STUDY DESIGN

Systematic review of treatment-specific, condition-specific trials, studies, and case reports of chiropractic care for low back pain.

METHODS

Computerized searching and hand searching were used to identify references in the medical and chiropractic literature pertaining to the chiropractic treatment of low back pain in which both the condition and specific treatment procedures were adequately described. This literature was then categorized according to a variety of characteristics and used by a panel to evaluate the specific procedures.

RESULTS

The 3 most studied adjustive procedures are side-posture high-velocity, low-amplitude; distraction (mostly flexion distraction); and mobilization, respectively. The clinical condition most commonly addressed by the included studies is low back pain. The procedure with the widest base of evidence support is side posture manipulation for low back pain.

Multiresidue determination of fluoroquinolones in eggs

A multiresidue method was developed for the determination of fluoroquinolones in eggs. Extraction of eggs with ammoniacal acetonitrile was followed by liquid-liquid defatting, solvent evaporation, and redissolution in a small volume of buffer. The fluoroquinolones were further purified by on-line microdialysis, concentrated on a trace enrichment column, and separated by reversed-phase liquid chromatography with fluorescence detection. Norfloxacin (NOR), ciprofloxacin (CIP), and sarafloxacin (SAR) were extracted from fortified eggs over a range of 2-200 microg/kg, with recoveries of 65.7-78.9%, 65.6-77.1%, and 67.6-110%, respectively. Enrofloxacin (ENRO) was extracted over a range of 1-100 microg/kg, with recoveries of 71.5-86.7%, whereas desethylene ciprofloxacin (DCIP) and danofloxacin (DANO) were extracted over a range of 0.2-20 microg/kg, with recoveries of 68.7-90.7% and 76.0-93.8%, respectively. The limits of quantitation for the 6 fluoroquinolones were as follows: DCIP and DANO, 0.3 microg/kg; ENRO, 1 microg/kg; NOR and CIP, 2 microg/kg; and SAR, 3 microg/kg. Both SAR and ENRO incurred eggs were also successfully analyzed using this method.

Simulation studies: a new method of prospective technology assessment and design

In order to examine the social conditions and effects of a broad usage of telecooperation technology in the future, such as the development of design proposals, PROVET (Projektgruppe Verfassungsverträgliche Technikgestaltung) developed the method of simulation studies. The paper describes the problem of prospective technology design for telecooperation, a method to handle it, the simulation studies and the methological background. It demonstrates three simulation studies, in administration of justice, about office dossiers and for a reachability management. It presents results, particularly about the psychological effects of the digital signature as a technical-organizational measure to guarantee obligations between the cooperation partners. The conclusion discusses this research approach in relation to others.

Cloning of a 5.8 kb cDNA for a mouse type 2 deiodinase

From studies with their cDNAs, the types 1 and 3 deiodinases (D1 and D3) have been shown unequivocally to be selenoproteins. Studies with recently cloned cDNAs for the mammalian type 2 deiodinase (D2) indicate that they also code for selenoproteins. However, these D2 cDNAs are not full length and they do not contain an essential selenocysteine insertion sequence (SECIS) in their 3'UTR; a heterologous SECIS had to be ligated to the coding region before expression of the D2 could be achieved. Thus their role as cDNAs for the native D2 is open to question. We now report the cloning of a 5.8 kb cDNA for the mouse D2. This cDNA contains a SECIS in its 3'UTR located more than 4.5 kb from the coding region. When the mRNA transcribed in vitro from this cDNA is injected into X. laevis oocytes, a deiodinase with characteristics of D2 is expressed.

Isolation and characterization of the mouse gene for the type 3 iodothyronine deiodinase

The type 3 iodothyronine deiodinase (D3) is a selenoenzyme that inactivates thyroid hormones by removing a iodine from the 5-position of the tyrosyl ring. D3 is highly expressed in many tissues during the early stages of development, and its activity is regulated by selected growth factors and various hormones. To gain further insights into the structure, functional role, and regulation of this enzyme, we screened a mouse liver genomic library with a rat D3 complementary DNA probe and isolated a 12-kb clone coding for the Dio3. Restriction analysis followed by Southern blotting and nucleotide sequencing demonstrated that the Dio3 contains a single exon, 1853 bp in length, that encodes the entire length of the messenger RNA expressed in murine placenta and neonatal skin. Primer extension experiments identified two potential transcriptional start sites located 77 and 60 nt upstream of the ATG translational start codon. The region immediately 5' to the start sites contains consensus TATA, CAAT, and GC elements. Furthermore, a 526-nucleotide genomic fragment from this region was demonstrated to efficiently drive a luciferase reporter construct when transfected into COS-7, XTC-2, or XL-2 cells or into primary cultures of rat preadipocytes derived from neonatal brown fat. In conclusion, D3 transcripts in the placenta and skin are encoded by the Dio3 gene from a single exon whose expression is regulated by an upstream region that contains several consensus promoter elements. Further characterization of this gene will provide new insights into the factors regulating the unique pattern of D3 expression during development.

The type 2 and type 3 iodothyronine deiodinases play important roles in coordinating development in Rana catesbeiana tadpoles

In developing Rana catesbeiana tadpoles, the timing of the thyroid hormone (TH)-dependent metamorphic responses varies markedly among tissues. Yet at any one time these tissues are exposed to the same plasma concentration of TH, suggesting that TH action is regulated in part at the level of the peripheral tissues. A major factor in TH action is the intracellular level of the active TH, T3. This level is dependent not only on the plasma concentration of TH (mostly T4) but also on the intracellular activities of the type 2 5'-deiodinase (D2) and the type 3 5-deiodinase (D3), which are responsible, respectively, for generating and degrading T3. (D1 is not present in this species.) To determine whether differential expression of D2 and D3 among tissues could be a significant factor in the coordination of metamorphic events, the ontogenic profiles of the two enzyme activities and corresponding messenger RNA levels in most tissues of R. catesbeiana tadpoles have been documented. The profiles of D2 expression in tail, hindlimb, forelimb, intestine, skin, and eye differed markedly at both activity and messenger RNA levels, but it was notable that expression was invariably highest in a given tissue at the time of its major metamorphic change. D2 expression was very low in brain and heart and did not vary during development. D2 was not expressed in liver, kidney, or red blood cells. With the exception of red blood cells, D3 expression was detected in all tissues studied. Furthermore, it was evident that in tissues that expressed both deiodinase genes, the two expression profiles were comparable, indicating a potential for tight control of intracellular T3 levels. Direct evidence of the importance of the intracellular conversion of T4 to T3 for TH-dependent metamorphic events was obtained in tadpoles in which endogenous TH synthesis was blocked with methimazole, and the activities of D2 and D3 were inhibited by iopanoic acid. This treatment inhibited metamorphosis. The inhibition could be overcome by the concomitant administration of replacement levels of T3, but not T4. These results strongly support the view that coordinated development in amphibia depends in part on the tissue-specific expression patterns of the D2 and D3 genes, which ensure that the requisite level of intracellular T3 is attained in a given tissue, regardless of the current level of circulating TH, at the appropriate stage of metamorphosis.

Cloning of a cDNA for the type II iodothyronine deiodinase

Three types of iodothyronine deiodinase have been identified in vertebrate tissues. cDNAs for the types I and III have been cloned and shown to contain an inframe TGA that codes for selenocysteine at the active site of the enzyme. We now report the cloning of a cDNA for a type II deiodinase using a reverse transcription/polymerase chain reaction strategy and RNA obtained from Rana catesbeiana tissues. This cDNA (RC5'DII) manifests limited but significant homology with other deiodinase cDNAs and contains a conserved in-frame TGA codon. Injection of capped in vitro synthesized transcripts of the cDNA into Xenopus laevis oocytes results in the induction of deiodinase activity with characteristics typical of a type II deiodinase. The levels of RC5'DII transcripts in R. catesbeiana tadpole tail and liver mRNA at stages XII and XXIII correspond well with that of type II deiodinase activity but not that of the type III activity in these tissues. These findings indicate that the amphibian type II 5'-deiodinase is a structurally unique member of the family of selenocysteine-containing deiodinases.

The type III 5-deiodinase in Rana catesbeiana tadpoles is encoded by a thyroid hormone-responsive gene

We have recently reported that the Xenopus laevis complementary DNA (cDNA), XL-15, encodes a selenoprotein that is a 5-deiodinase (5D). XL-15 represents a gene that is up-regulated by thyroid hormone in this species. We now report the isolation from a Rana catesbeiana (RC) cDNA library of a cDNA for the RC 5D (RC5D). RC5D a 1534-base pair cDNA that exhibits 78% identity to XL-15 in the coding region, including the TGA codon, which in XL-15 encodes selenocysteine, and a putative selenocysteine insertion sequence (SECIS) located in the 3'-untranslated region. Transcripts of RC5D, synthesized in vitro, induce 5D activity after their injection into Xenopus laevis oocytes. RC5D hybridizes to a 2.2-kilobase messenger RNA (mRNA) species in RC tissues. The expression of RC5D was studied in 10 tissues from untreated and T3-treated premetamorphic tadpoles. RC5D mRNA transcripts and 5D activity were detected in most tissues examined, and the levels of both were greatly increased in T3-stimulated tadpoles. Furthermore, the levels of RC5D mRNA transcripts correlated closely with 5D, but not with 5'-deiodinase (5'D), activity. 5'D was not enhanced by a 4-day exposure of the tadpoles to T3. The up-regulation of RC5D gene expression by T3 was demonstrable in tadpoles by stage V, but was found to be transient. The levels of RC5D transcripts and 5D activity were highest after 2-3 days and 5 days of T3 exposure, respectively, but had fallen by 10 days to levels comparable to those in unexposed tadpoles. It is concluded that RC5D encodes a selenoprotein that is a 5D, and it represents a gene that is up-regulated by T3. On the basis of the findings presented herein, it is suggested that the 5D system plays a major role in regulating intracellular T3 levels in developing tadpoles.

Cloning and expression of a cDNA for a mammalian type III iodothyronine deiodinase

The type III iodothyronine deiodinase metabolizes the active thyroid hormones thyroxine and 3,5,3'-triiodothyronine to inactive compounds. Recently, we have characterized a Xenopus laevis cDNA (XL-15) that encodes a selenoprotein with type III deiodinase activity (St. Germain, D.L., Schwartzman, R., Croteau, W., Kanamori, A., Wang, Z., Brown, D.D., and Galton, V.A. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 7767-7771). Using the XL-15 as a probe, we screened a rat neonatal skin cDNA library. Among the clones isolated was one (rNS43-1) which contained a 2.1-kilobase pair cDNA insert that manifested significant homology to both the XL-15 and the G21 rat type I deiodinase cDNAs, including the presence of an in-frame TGA codon. Expression studies demonstrated that the rNS43-1 cDNA encodes a protein with 5-, but not 5'-, deiodinase activity that is resistant to inhibition by propylthiouracil and aurothioglucose. Northern analysis demonstrated a pattern of tissue expression in the rat consistent with that of the type III deiodinase and site directed mutagenesis confirmed that the TGA triplet codes for selenocysteine. We conclude that the rNS43-1 cDNA encodes the rat type III deiodinase and that the types I and III deiodinases present in amphibians and mammals constitute a family of conserved selenoproteins important in the metabolism of thyroid hormones.

Tender points/fibromyalgia vs. trigger points/myofascial pain syndrome: a need for clarity in terminology and differential diagnosis

OBJECTIVE

This study reviews the clinical distinctions between fibromyalgia (FM) and myofascial pain syndrome (MPS), which represent two separate and distinct soft-tissue syndromes. The major aim of this article is to clarify the terminology associated with these syndromes and clearly define the parameters of differential diagnosis and treatment.

DATA SOURCES

Pertinent articles in the chiropractic and medical literature are reviewed with an emphasis on the literature published from 1985-1994.

STUDY SELECTION

Studies were selected that emphasized differential diagnosis of FM and MPS, as well as individual articles on either FM or MPS.

DATA SYNTHESIS

The literature on fibromyalgia and myofascial pain syndromes has grown considerably since 1985. It is now clear that there are several important differences between FM and MPS. The most important criteria for differential diagnosis are the presence of tender points (TePs) and widespread, nonspecific, soft tissue pain in FM, compared with regional and characteristic referred pain patterns with discrete muscular trigger points (TrPs) and taut bands of skeletal muscle in MPS. The etiology of TePs is still unknown and it is uncertain which specific soft tissues are tender in FM patients. Myofascial TrPs are found within a taut band of skeletal muscle and have a characteristic "nodular" texture upon palpation. TrPs are thought to develop after trauma, overuse or prolonged spasm of muscles. Local treatment applied to TePs is ineffective, yet specific treatment of TrPs is often dramatically effective.

CONCLUSION

FM and MPS are two different clinical conditions that require different treatment plans. FM is a systemic disease process, apparently caused by dysfunction of the limbic system and/or neuroendocrine axis. It often requires a multidisciplinary treatment approach including psychotherapy, low dose antidepressant medication and a moderate exercise program. MPS is a condition that arises from the referred pain and muscle dysfunction caused by TrPs, which often respond to manual treatment methods such as ischemic compression and various specific stretching techniques. Both of these conditions are seen routinely in chiropractic offices; therefore, it is important for field practitioners to understand these distinctions.

Effect of glucocorticoids on thyroid hormone action in cultured red blood cells from Rana catesbeiana tadpoles

Metamorphosis in anuran amphibia requires thyroid hormone (TH) and can be induced prematurely by the administration of TH. There is also evidence that the developmental effects of TH in these forms are modified by other hormones. For example, PRL has been shown to retard and corticosterone (B) to accelerate some, but not all, components of TH-induced metamorphosis. Red blood cells (RBCs) of Rana catesbeiana tadpoles exhibit a 4- to 5-fold increase in thyroid hormone receptor (TR) number (sites per nucleus) in vivo during either spontaneous or TH-induced metamorphosis. In the present study this TH-induced effect on RBC TR number was examined in an in vitro culture system. RBC TR number was increased by T3 in vitro; the maximum effect (2-fold increase) was obtained after exposure to 0.3 nM T3 for 60 h. This T3-induced increase in TR number was completely abolished in the presence of either 34 nM B or 10 nM dexamethasone, whereas basal TR number was unaffected. The effect appears to be a specific effect of glucocorticoid (GC), because it was not mimicked by the sex steroid, testosterone, and it was not obtained when RU-486, a glucocorticoid antagonist, was included with B in the medium. Other experiments demonstrated that the T3-induced increase in RBC TR was associated with an increase in the TR alpha messenger RNA level. This increase in TR alpha messenger RNA was reduced, but not eliminated, in the presence of concentrations of GC that abolished the TH-induced increase in TR, suggesting that the effects of GC occur in part at a pretranslational level. Using a GC binding assay, tadpole RBCs were found to contain approximately 10(4) GC receptors/cell. These findings indicate that B may be a physiological modulator of TH action in tadpole RBCs. This inhibitory effect of GC contrasts with previous reports that GC accelerates some of the morphological effects of TH in developing tadpoles, indicating that the nature of this modulating effect on TH action is tissue specific.

Cloning of a thyroid hormone-responsive Rana catesbeiana c-erbA-beta gene

Two types of thyroid hormone receptor (c-erbA) gene have been identified in mammals and in lower species including chickens and the amphibian Xenopus laevis. The two genes are located on different chromosomes and have been named TR alpha and TR beta. We have described previously the cloning of a TR alpha cDNA from Rana catesbeiana (RC) tissues (RC15) and we now report the cloning of a TR beta cDNA from this species. The cloning strategy employed utilized the polymerase chain reaction (PCR), with primers based on the sequences of the X. laevis TR beta cDNA (XenTR beta) and an RCTR beta genomic clone, which, by analogy with XenTR beta, contains some of the 3' end of the open reading frame together with 3'-untranslated sequences. At the nucleotide and amino acid levels, respectively, the cloned RCTR beta cDNA is 90% and 98% homologous with XenTR beta, and 72% and 76% homologous with RC15. Following in vitro transcription and translation, the cDNA was shown to encode a 48 kilodalton protein which binds 3,5,3'-triiodothyronine (T3) with high affinity (mean Kd: 0.032 nM). Samples of total or poly(A) +RNA from tadpoles at different stages of metamorphosis and from adult frogs were analyzed for the presence of TR beta-specific transcripts by slot blot analysis using as probe a 258 bp section of the RCTR beta cDNA. This section of the cDNA does not hybridize to the corresponding section of RC15. In confirmation of previous findings, beta-specific transcripts were not detected in RNA from tadpole red blood cells (RBCs) and none was found in RBCs from adult frogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Rana catesbeiana tadpole red blood cells express an alpha, but not a beta, c-erbA gene

Thyroid hormone (TH) receptor number in red blood cells (RBCs) from Rana catesbeiana (RC) tadpoles increases 4-fold during both spontaneous and TH-induced metamorphosis, an effect that we have previously shown to be preceded by an increase in the level of c-erbA-related mRNA. The goals of the present study were to obtain an RC c-erbA alpha cDNA that contains the entire open reading frame for a putative TH receptor protein, to determine if this protein has characteristics typical of a TH receptor, and to assess its contribution to the developmentally related increase in TH receptor number. To accomplish this, the missing 5'-sequence of a previously isolated partial RC c-erbA alpha cDNA (RC12) was synthesized by polymerase chain reaction (PCR) and spliced to RC12 to yield a 1490-basepair cDNA (RC15) that contained the entire coding sequence of the receptor protein. Transcription of RC15 followed by translation of its mRNA in a rabbit reticulolysate system yielded a 50-kilodalton protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The protein binds T3 with high affinity (Kd, approximately 0.1 nM), and its affinity for T3 is at least 5 times that for T4. The results of cotransfection studies indicate that RC15 can function as a TH receptor; when COS cells were cotransfected with a construct consisting of RC15 cloned in the expression vector CMV4 and TK28 mult, a construct containing rat GH gene TH response element sequences up-stream of a chloramphenicol acetyltransferase reporter gene, chloramphenicol acetyltransferase activity is expressed in the presence, but not in the absence, of T3. To determine whether RBCs contain any c-erbA beta mRNA transcripts that might contribute to the developmentally related increase in the transcripts detected using RC c-erbA alpha cDNAs, alpha- and beta-specific cDNAs were synthesized by PCR and used as probes in a variety of hybridization assays. In all experiments using conditions in which c-erbA beta transcripts were detectable in other tissues, there was no evidence that tadpole RBCs contained such species. Lack of any beta-specific transcripts was confirmed by PCR, using as template cDNA prepared by reverse transcription of RC RBC RNA. It was also noted that the RBC at metamorphic climax is the tissue with the highest content of alpha-specific c-erbA transcripts. It is concluded that the c-erbA alpha gene encodes a TH receptor, and that only the alpha-gene is expressed in tadpole RBCs and subject to regulation during development and by TH.

Polypeptide toxins from the venoms of Old World and New World scorpions preferentially block different potassium channels

Venoms from five Old World and two New World scorpions were tested for their ability to block various K+ channels in rat brain synaptosomes. A 86Rb efflux kinetic assay was used to identify three types of K+ channels, Ca(2+)-independent, voltage-gated, inactivating (A-type) and noninactivating (delayed rectifier) K+ channels and Ca(2+)-activated K+ channels [J. Physiol. (Lond.) 361:419-440, 441-457 (1985)]. The venoms from the Old World scorpions all blocked the A-type K+ channel but not the delayed rectifier K+ channel; only venom from the Israeli scorpion, Leiurus quinqestriatus hebraeus (Lqh), blocked the Ca(2+)-activated K+ channel. In contrast, venoms from the two New World scorpions selectively blocked the delayed rectifier K+ channel. Water-soluble components from Lqh venom from the Brazillian scorpion, Tityus serrulatus (Ts), were separated by ion exchange high performance liquid chromatography (HPLC). Seven components that blocked synaptosome K+ channels were isolated from Lqh venom by ion exchange HPLC. All seven components blocked the A-type K+ channel; the five most potent toxins had IC50 values of 18-40 nM. Two of the components from Lqh venom (one identified as charybdotoxin and the other denoted as Lqk4) also blocked a Ca(2+)-activated K+ channel (IC50 = 15 and 60 nM for charybdotoxin and Lqk4, respectively). Five K+ channel-blocking components were isolated from the Ts venom; all five blocked the delayed rectifier channel selectively, and the two most potent components had IC50 values of 8 and 30 nM. Several of the more potent Lqh and Ts toxins were purified to near-homogeneity by reverse phase HPLC. These toxins should be useful as ligands for K+ channel purification, for elucidation of K+ channel structure, and for studies of K+ channel function.

The role of thyroid hormone in the regulation of hepatic carbamyl phosphate synthetase activity in Rana catesbeiana

Both spontaneous and thyroid hormone (TH)-induced metamorphosis of Rana catesbeiana are accompanied by a marked increase in the activity of the urea cycle enzyme carbamyl phosphate synthetase (CPS). The increase induced by exogenous TH is de novo synthesis of enzyme and appears to be secondary to an increase in the CPS mRNA level resulting from the elevated plasma TH. Since endogenous TH levels rise sharply during spontaneous metamorphosis, a similar sequence of events would be anticipated. However, after midclimax, CPS activity continues to increase, while plasma TH levels steadily decline, suggesting that other factors are involved. To obtain insight into this problem, the changes in CPS mRNA level during spontaneous development were determined using a mammalian CPS cDNA probe and correlated with changes in CPS activity and plasma T3 concentration. CPS mRNA level and CPS activity were barely detectable until midprometamorphosis, but both increased rapidly during the latter half of this phase. CPS activity continued to rise, reaching a maximum in the adult frog. The CPS mRNA level, however, was highest during the first half of climax, but declined after midclimax and was relatively low in the adult frog. Studies were also performed in which the rise and fall in the plasma T3 concentration typical of metamorphic climax were induced by exposure of premetamorphic tadpoles to T3, followed by its withdrawal. Both CPS activity and CPS mRNA level were induced by T3, but when plasma T3 levels fell after removal of the exogenous T3, CPS mRNA level, but not CPS activity, also decreased. Additional studies indicated that the TH-induced increase in CPS mRNA was evident within 24 h, could be prevented by simultaneous injection of actinomycin-D, and could not be induced in tadpoles undergoing climax; in this phase the T3 receptors are fully occupied with endogenous TH. When premetamorphic tadpoles were immersed in T3-containing water (0-500 nM) for 6 days, CPS mRNA, CPS activity, and plasma T3 concentration increased in parallel, reaching a maximum at 50 nM. At 50 nM T3, the plasma T3 level was sufficient to saturate the receptors, and no additional increase in CPS mRNA level or CPS activity was obtained at higher concentrations of T3. These studies indicate that the CPS mRNA level during spontaneous development correlates with the plasma T3 concentration and suggest that it is a function of T3 receptor occupancy. The data are also consistent with an effect of TH on transcription of the CPS gene and with a relatively long half-life of its protein product, the CPS enzyme.

Regulation of c-erbA-alpha messenger RNA species in tadpole erythrocytes by thyroid hormone

Putative thyroid hormone (TH) nuclear receptors have been detected in several tissues of Rana catesbeiana tadpoles. T3 receptor number (sites per nucleus) in red blood cells (RBCs) and tail increases substantially just before metamorphic climax or in response to exogenous TH; in contrast, receptor number in liver remains relatively constant. TH receptors in mammals and birds are thought to be encoded by a c-erbA gene. In the present study, two c-erbA cDNAs, one prepared from Xenopus laevis oocytes (XenTR alpha 1) and one prepared from Rana catesbeiana tail (RC12), were used to examine the c-erbA-related mRNA species in Rana catesbeiana tissues and determine their role in the TH induction of tadpole RBC receptor number. XenTR alpha 1 encodes a protein with T3-binding properties typical of TH receptors. RC12 is almost 99% homologous with XenTR alpha 1 at the amino acid level and contains all of the putative T3-binding region and most of the DNA-binding region. Using either cDNA as a probe, it was found that two major species of c-erbA-related mRNA species (2.6 and 4.0 kilobases) were clearly evident in tadpole RBCs, tail, and liver. A third, more diffuse band (approximately 5.0 kilobases) was observed in RBC and tail. In RBCs, but not in liver, the combined level of c-erbA-related mRNA species was increased during spontaneous metamorphosis or after administration of TH. Furthermore, the TH-induced increase in both c-erbA-related mRNA species and receptor number in RBCs was prevented if actinomycin-D was administered with TH.(ABSTRACT TRUNCATED AT 250 WORDS)

Charybdotoxin blocks both Ca-activated K channels and Ca-independent voltage-gated K channels in rat brain synaptosomes

Charybdotoxin (ChTX), a 4.3 kDa polypeptide toxin from the venom of the scorpion Leiurus quinquestriatus, blocks both a Ca-activated K channel (IC50 approximately 15 nM) and a Ca-independent voltage-gated K channel (IC50 approximately 40 nM) in rat brain synaptosomes. These results indicate that in this preparation ChTX is not specific for the Ca-activated K channel and suggest that there may be structural homology among the toxin-binding sites on various types of K channels.

A comparison of aggressive and withdrawn children's self-esteem, optimism and pessimism, and causal attributions for success and failure

Aggressive children, withdrawn children, combined aggressive and withdrawn children, and children displaying neither aggressive nor withdrawn behavior were compared on three self-appraisal measures: (a) self-esteem, (b) attributions to ability and lack of ability following success and failure, and (c) optimism and pessimism about one's long-term personal future. From an initial sample of 583 elementary school children, independent and extreme groups were identified by combined ratings of teachers and classmates. Solely aggressive children had higher self-esteem than either solely withdrawn children or children who were both aggressive and withdrawn. The control group of children who were neither aggressive nor withdrawn had the highest self-esteem of all. The control group also attributed success to ability more than the two groups of children with high withdrawal scores but did not differ from the solely aggressive children. There were no significant differences among the groups in attributions to lack of ability following failure or in optimism or pessimism.

Atracurium, vecuronium, and intraocular pressure in humans

We studied 60 nonophthalmologic patients, allocated to six treatment groups, to assess the effects of atracurium and vecuronium on intraocular pressure (IOP). All patients had IOP measured while awake, using pneumotonometry. In group 1, anesthesia was induced with thiopental, 5 mg/kg, and maintained with N2O, 70% in O2, using controlled mask ventilation, for 5 min. These patients then received atracurium, 0.5 mg/kg. After 5 additional minutes of ventilation, the trachea was intubated. From 1 min after thiopental administration until 1 min after intubation, IOP was recorded every minute. Patients in groups 2, 3, and 4 were treated identically to those in group 1, except the muscle relaxant given was atracurium, 1.0 mg/kg, vecuronium, 0.1 mg/kg, or vecuronium, 0.2 mg/kg, respectively. Patients in groups 5 and 6 underwent rapid sequence induction with thiopental, 5 mg/kg, and atracurium, 1.0 mg/kg, or vecuronium, 0.2 mg/kg, respectively. IOP was measured 1 min later, followed by intubation and IOP measurements for the next 3 min. Intraocular pressure decreased significantly in groups 1, 2, 4, and 6 after thiopental and remained stable in all groups during ventilation with N2O. Neither atracurium nor vecuronium affected IOP, nor was there any correlation between IOP and degree of neuromuscular blockade. However, IOP increased significantly after intubation in all six groups. We conclude that atracurium or vecuronium alone has no adverse effects on IOP.

Bladder cancer: results of radiation therapy in 384 patients

Between 1957 and 1972, 384 patients with bladder cancers were treated initially with megavoltage radiation therapy. Actuarial five-year survival ranged from 35 to 42% for Stages A and B1 tumors, and was 35, 22 and 7%, respectively, for Stages B2, C and D carcinomas. Approximately 30-40% of deeply invasive tumors confined to the bladder can be controlled with radiation therapy alone, directed solely to the bladder itself.

Contributions of photosynthesis and phytochrome to the formation of anthocyanin in turnip seedlings

Turnip seedlings (Brassica rapa L.) irradiated for 24 hours with radiation at 720 nanometers synthesize chlorophyll a and anthocyanin. Antimycin A and 2,4-dinitrophenol, which are known to reduce cyclic photophosphorylation, also reduce anthocyanin synthesis. Noncyclic photophosphorylation is inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea and o-phenanthroline. These compounds promote cyclic photophosphorylation and anthocyanin synthesis. On the basis of these findings it is suggested that the photomorphogenic response of anthocyanin synthesis in turnip seedlings arises in part through photosynthetic activity.Phytochrome involvement in turnip seedling photomorphogenesis is evidenced by the photoreversibility of anthocyanin synthesis in response to 5-minute irradiations with red or far red light. The inhibition of anthocyanin synthesis by 2,4-dinitrophenol does not arise from a destruction of phytochrome photoreversibility.It is suggested that plant photomorphogenic responses to prolonged far red irradiations arise through the photochemical activation of at least two pigment systems; namely, the photosynthetic pigments and phytochrome.

Optical activity of biological membranes: scattering effects and protein conformation

THE FOLLOWING QUESTION HAS RECENTLY ARISEN IN THE LITERATURE CONCERNING THE INTERPRETATION OF THE OPTICAL ACTIVITY OF BIOLOGICAL MEMBRANES: do the characteristic spectral distortions observed for diverse membrane systems reflect some common and unique aspect of membrane architecture or are they the result of scattering effects owing to the particulate nature of membranous systems? We have confirmed the latter interpretation on the basis of the following experimental observations: (a) red blood cell membranes give a normal circular dichroism spectrum when scattering is reduced and (b) nonaggregated, nonmembranous helical proteins give distorted membranelike spectra when scattering is introduced. An improved estimate of secondary structure on the basis of undistorted spectra results in about 50 per cent alpha-helix for red blood cell membrane protein. In addition we conclude that the distortions in optical activity spectra offer no evidence in support of various proposed membrane models.

Nucleic acid metabolism during cytokinin induced cellular differentiation

Edstrom's microphoresis technique has been employed to determine the quantitative alterations in nucleic acid content and base composition of individual cells associated with the initiation of bud primordia in Funaria hygrometrica. The filamentous protonema of this moss initiates bud cells which through repeated divisions form the leafy gametophores. The cytokinin, 6-furfurylaminopurine (kinetin), was used to induce the differentiation of bud cells from protonematal cells. The total RNA content of kinetin-induced bud cells (22.0 mumug/cell) was nearly 15 times that of protonematal cells (1.6 mumug/cell). The same dramatic increase in total RNA was apparent in bud cells which developed spontaneously in older cultures. As would be predicted, the adenine (A) to guanine (G) ratio for DNA from bud and protonematal cells was identical (0.7). The A:G ratio for RNA from bud cells (1.0) was much lower than that from protonematal cells (1.7). Thus, kinetin-induced differentiation in this system involves a dramatic increase in total RNA, the base composition of which approaches that of DNA. The base composition (A:G ratio) of DNA remains constant.

Photocontrol of Mimosa pudica L. leaf movement

1. Mimosa pudica L. pinnae close in darkness when phytochrome is predominantly in the far-red-absorbing form (Pfr) and remain open when Pfr is low [6]. The leaflets remain open, however, in normal light periods irrespective of the form of phytochrome. Pinnae, after closing in darkness, regularly reopen in light. 2. An action spectrum for the opening response shows maxima for effectiveness near 710 and 480 nm. This action spectrum is similar to that for a high-energy response affecting morphogenesis in many plants. 3. Dropping of the petiole of M. pudica can be photostimulated by irradiation of the primary pulvinus after holding the plants in darkness [4]. 4. The photostimulation of the primary pulvinus is effective only at wavelengths less than 520 nm. Wave bands in the region of 400 to 470 nm are about equally effective. 5. These photoresponses of M. pudica are related to current discussion about the nature of the high-energy and phytochrome photomorphogenic reactions.