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R W Hardy

Publications and source records attributed to R W Hardy.

At least 37 records · Page 2Linked to original sources
PubMed1997

Regulation of osteoclastic bone resorption by glucose.

Osteoclasts degrade bone by pumping molar quantities of HCl to dissolve the calcium salts of bone, an energy intensive process evidently supported by abundant mitochondria. This is the first study to directly examine the ability of various metabolites to serve as potential energy sources for osteoclastic bone resorption. Glucose, and to a lesser extent lactate, supported osteoclastic bone degradation. However, fatty acids (palmitate, myristate and stearate), essential amino acids plus 20 mM alanine, or ketone bodies (acetoacetate, beta-hydroxybutyrate and alpha-ketoglutarate) did not support bone degradation. Resorption declined to 10-30% of glucose controls when fatty acids or ketoacids were substituted for glucose. Resorption was glucose concentration dependent, with maximal activity at approximately 7 mM (K(M) approximately 3 mM). Glucose transport was linear for approximately 15 minutes, specific for D-glucose, and inhibited by cytochalasin B. Osteoclasts cultured on bone transported glucose at almost twice the rate of those off bone (Vmax 23 versus 13 nmols/mg/min, respectively) and medium acid accumulation paralleled glucose uptake, while the K(M) was unchanged. We conclude that glucose is the principal energy source required for bone degradation. Further, characteristics of glucose transport are consistent with the hypothesis that fluctuations in serum glucose concentration are an important component in regulation of osteoclastic bone degradation.

Alanine↗
PubMed1997

Fatty acids and breast cancer cell proliferation.

We and others have shown that fatty acids are important regulators of breast cancer cell proliferation. In particular individual fatty acids specifically alter EGF-induced cell proliferation in very different ways. This regulation is mediated by an EGFR/G-protein signaling pathway. Understanding the molecular mechanisms of how this signaling pathway functions and how fatty acids regulate it will provide important information on the cellular and molecular basis for the association of dietary fat and cancer. Furthermore these in vitro studies may explain data previously obtained from in vivo animal studies and identify "good" as well as "bad" fatty acids with respect to the development of cancer.

Animals↗
PubMed1997

InsP3 receptor is essential for growth and differentiation but not for vision in Drosophila.

Phospholipase C (PLC) is the focal point for two major signal transduction pathways: one initiated by G protein-coupled receptors and the other by tyrosine kinase receptors. Active PLC hydrolyzes phosphatidylinositol bisphosphate (PIP2) into the two second messengers inositol 1,4,5-trisphosphate (InsP3) and diacyl glycerol (DAG). DAG activates protein kinase C, and InsP3 mobilizes calcium from intracellular stores via the InsP3 receptor. Changes in [Ca2+]i regulate the function of a wide range of target proteins, including ion channels, kinases, phosphatases, proteases, and transcription factors (Berridge, 1993). In the mouse, there are three InsP3R genes, and type 1 InsP3R mutants display ataxia and epileptic seizures (Matsumoto et al., 1996). In Drosophila, only one InsP3 receptor (InsP3R) gene is known, and it is expressed ubiquitously throughout development (Hasan and Rosbash, 1992; Yoshikawa et al., 1992; Raghu and Hasan, 1995). Here, we characterize Drosophila InsP3R mutants and demonstrate that the InsP3R is essential for embryonic and larval development. Interestingly, maternal InsP3R mRNA is sufficient for progression through the embryonic stages, but larval organs show asynchronous and defective cell divisions, and imaginal discs arrest early and fail to differentiate. We also generated adult mosaic animals and demonstrate that phototransduction, a model PLC pathway thought to require InsP3R, does not require InsP3R for signaling.

Animals↗
PubMed1997

Fatty acid-induced insulin resistance in adipocytes.

Elevated serum-free fatty acid (FFA) levels induce insulin resistance in whole animals and humans. To understand the direct mechanism by which FFAs impact insulin-responsive tissue, we have used our previously developed in vitro model of long-chain saturated fatty acids (LCSFA)-induced insulin resistance in adipocytes. In addition to explanted rat adipocytes, we now demonstrate that overnight exposure of 3T3-L1 adipocytes to 1 mM individually of the LCSFA palmitate, myristate, and stearate, leads to an approximately 50% inhibition of insulin-induced glucose transport. Insulin resistance can be accomplished at 0.3 mM palmitate, which is within the range ofpalmitate found in diabetic and obese individuals. This inhibition was noted within 4 h of exposure to FFA, which is comparable to in vivo lipid infusion studies. Initial LCSFA-induced resistance is specific to glucose transport and does not affect insulin stimulation of glucose incorporation into glycogen. In 3T3-L1 adipocytes overexpressing the EGF receptor, LCSFA exposure also specifically inhibited EGF-induced GLUT4-mediated glucose transport, but not EGF-induced glycogen synthesis. We find that LCSFA treatment did not impair insulin stimulation of GLUT4 translocation or exofacial presentation on the cell surface as determined by trypsin accessibility. Our results suggest that the initial direct effect of elevated LCSFA is to impair activation of GLUT4 transporter activity and that this effect is specific for glucose transport.

Adipocytes↗
PubMed1997

A role for phospholipase C activity in GLUT4-mediated glucose transport.

Overexpression of surrogate receptors [epidermal growth factor (EGF) receptor (EGFR) and platelet-derived growth factor receptor] in adipocytes has demonstrated that multiple signaling pathways may lead to GLUT4-mediated glucose uptake. These implicated pathways function independently of IRS-1 phosphorylation and PI3-kinase activation. In addition, we previously demonstrated that EGFR tyrosyl autophosphorylation is required to stimulate GLUT4-mediated glucose transport in 3T3-L1 adipocytes. This observation suggests that signaling molecules that are dependent on EGFR autophosphorylation, such as phospholipase C (PLC), may lie in the signaling pathway to glucose transport. As PLC has been implicated in glucose transport by several clinical and basic mechanistic studies, we investigated whether EGFR signaling may promote glucose transport via modulation of PLC activity. Activation of EGFR overexpressing 3T3-L1 adipocytes leads to a 3.4 +/- 1.2-fold stimulation of PLC activity over basal levels vs. only 1.06 +/- 0.01-fold stimulation by insulin. Pharmacological inhibition of PLC by 50 microM U73122 reduced phosphoinositide accumulation by 79.2 +/- 16.9% and resulted in a concomitant 56.0 +/- 12.7% decrease in EGF-induced glucose transport. This inhibition of glucose transport by U73122 was specific, because the inactive congener, U73343, failed to block EGF-induced glucose transport. Despite the low levels of insulin-induced PLC activity, insulin-stimulated glucose transport activity was similarly inhibited by U73122 (55.9 +/- 13.1% inhibition). Inhibition of PLC activation did not impair either EGF- or insulin-induced activation of glycogen synthase or incorporation of glucose into lipid, supporting the hypothesis that both EGF- and insulin-induced glucose disposal can be independent of GLUT4-mediated glucose transport. The diminution of glucose transport secondary to inhibition of PLC activity was reflected by a decrease in GLUT4 translocation to the plasma membrane upon either EGF or insulin stimulation. These results are consistent with either a permissive or an active role for PLC activity in the translocation of GLUT4 to the plasma membrane.

3T3 Cells↗
PubMed1996

Correlative measurement of anterior margin of the anulus for surgical planning.

STUDY DESIGN: This study was a retrospective anatomic correlation of intervertebral disc dimensions with current surgical guidelines. OBJECTIVES: To develop safer guidelines for disc instrumentation. SUMMARY OF BACKGROUND DATA: Anterior perforation of the anulus fibrosus and injury to intra-abdominal structures is a known complication of lumbar discectomy. Coplanar magnetic resonance imaging of the lumbar intervertebral discs could decrease the rate of complication using axial 11-weighted scans. METHODS: Three measurements through the intervertebral discs of the lumbar spine were taken in 50 patients. These were correlated with current surgical guidelines for lumbar instrumentation. RESULTS: Most of the measurements exceeded the current suggested guidelines for instrumentation at 3 cm. CONCLUSIONS: Current guidelines for introduction of instruments into the lumbar disc spaces should be reevaluated. Appropriate measurements should be made on an individual basis.

Adult↗
PubMed1996

Epidermal growth factor induces glucose storage in transgenic 3T3-L1 adipocytes overexpressing epidermal growth factor receptors.

3T3-L1 adipocytes represent an established physiological model for studying glucose uptake and storage. Overexpression of epidermal growth factor (EGF) receptors in these cells (200,000-250,000 receptors per cell) confers EGF-inducible GLUT4-mediated glucose uptake (17). We now report that EGF receptor (EGFR)-mediated signals can induce incorporation of glucose into glycogen and lipids in these cells. Incorporation into lipids was stimulated to similar levels by insulin or EGF in adipocytes expressing full-length (wild type) EGFR (2.05 +/- 0.26-fold for insulin vs. 2.28 +/- 0.15-fold for EGF). EGF induced incorporation into glycogen at roughly 60% of the level of insulin (4.53 +/- 0.57-fold for insulin vs. 2.76 +/- 0.25-fold for EGF); this corresponded with similarly lower levels of glycogen synthase activation by EGF relative to insulin stimulation. EGFR kinase activity was required for induced storage because a kinase-inactive (M721) EGFR failed to stimulate glucose incorporation into glycogen or lipids. EGFRs that lack all or part of the unique EGFR COOH-terminal tail induced glucose incorporation at levels similar to that stimulated by full-length (wild type) EGFR. Thus, domains in the COOH-terminal tail of the EGFR, which are necessary for stimulating glucose transport, are not required for signaling EGF-induced glucose storage. EGF-induced glucose storage did not require de novo protein synthesis, suggesting that EGFR signaling uses existing pathways in the adipocytes. These data demonstrate that signaling pathways for EGFR-mediated glucose storage and GLUT4-mediated glucose transport diverge at the receptor level. Thus, EGF-induced glucose storage can be achieved in the absence of induced GLUT4-mediated glucose transport.

3T3 Cells↗
PubMed1996

Persistent back pain and sciatica in the United States: patient characteristics.

Low back pain is an extremely common, seriously disabling, nonfatal public health problem worldwide. The National Low Back Pain Study was a multicenter study of a large, heterogeneous group of patients who have been referred to either a neurosurgeon or an orthopedic surgeon for the evaluation and treatment of a persistent complaint of low back pain. In this paper, we characterize persistent low back pain patients and their complaints, describe the impact of persistent low back pain on the patients' functional and psychological status, report on the patients' medical characteristics, and identify treatments that are currently prescribed for these patients. Persistent low back pain is most common among people in their mid-to-late thirties and early-to-mid forties. The patients are mostly white, well educated, and generally affluent. The majority are gainfully employed, but some quit working because of pain and those who do tend to be less educated, and more likely to be involved in litigation. The average patient has had low back pain intermittently for 10 years. The pain is usually well localized but its severity varies considerably. Besides pain, most persistent low back pain patients report a variety of motor and sensory deficits. Patients also report significant functional impairment at work, at play, and at home. The typical patient does not, however, display significant psychological distress. Most patients have consulted multiple health care providers, have received a variety of treatments, and have used a variety of medications to alleviate pain; a few have been subjected to more aggressive treatment measures including surgery, intradiscal therapy, and narcotic and psychoactive drugs. None of these treatments has been effective. Physical examinations of these patients do not provide significant clues for making a definitive diagnosis. Nonspecific abnormalities such as muscle spasm, tenderness, and trigger points are quite common, but motor weakness and sensory deficits in the lower extremities, and reflex changes in the knees and ankles, are much less common. The classic combination of reflex changes, motor weakness, and sensory deficits associated with specific protruded discs are extremely rare even though one of three patients had a diagnosis of disc herniation. Diagnostic imaging studies revealed that the majority of persistent low back pain patients have spondylotic abnormalities involving root compression or lumbar instability or both, with root compression as the primary cause of the complaint. Myofascial syndrome and lumbar instability were the next most common diagnoses. After a thorough evaluation by specialists in spinal disorders, three of five persistent low back pain patients were prescribed an additional course of conservative therapy, one of five was prescribed surgery, and the rest were prescribed no treatment. Persistent low back pain patients appear to be a distinct group of low back pain patients who are different from patients who have similar nonpersistent acute symptoms and those who have the chronic pain syndrome characterized by significant behavioral and psychological co-morbidities.

Adult↗
PubMed1996

Stearate inhibition of breast cancer cell proliferation. A mechanism involving epidermal growth factor receptor and G-proteins.

Long chain saturated fatty acids are known to inhibit breast cancer cell proliferation; however, the mechanism of this inhibition is not known. Treatment of Hs578T breast cancer cells with long chain saturated fatty acids (0.15 mmol/L for 6 hours) before epidermal growth factor (EGF) treatment inhibited EGF-induced cell proliferation in a chain-length-dependent manner. Stearate (C:18) completely inhibited the EGF-induced cell proliferation, whereas palmitate (C:16) inhibited by 67 +/- 8% and myristate (C:14) had no effect. In contrast, stearate had little effect on insulin-like growth factor-1-stimulated cell proliferation. The inhibitory effect of stearate on cell proliferation was dose and time dependent and independent of EGF receptor (EGFR) tyrosine phosphorylation. Pretreatment of cells with pertussis toxin (0.1 microgram/ml for 24 hours) inhibited the EGF-induced cell growth by 50 +/- 8%, also independent of EGFR tyrosine phosphorylation. A pertussis-toxin-sensitive, 41-kd G-protein was specifically co-immunoprecipitated with the EGFR. Pretreatment of cells with 0.15 mmol/L stearate from 0 to 6 hours inhibits, in parallel, both the EGF-induced cell proliferation and pertussis-toxin-catalyzed ADP ribosylation of the G-protein associated with the EGFR. These studies suggest that long chain saturated fatty acids inhibit EGF-induced breast cancer cell growth via a mechanism involving an EGFR-G-protein signaling pathway.

Adenosine Diphosphate Ribose↗
PubMed1995

Classic neurogenic thoracic outlet syndrome in a competitive swimmer: a true scalenus anticus syndrome.

Neurogenic thoracic outlet syndrome (TOS) is caused by compression of the lower brachial plexus usually by a cervical rib or a fibrous band. We describe a 16-year-old girl with weakness and wasting of her right hand, which progressed over the ensuing years. She had been a competitive long distance freestyle and butterfly swimmer since age 8 years. A neurological exam at age 20, revealed severe atrophy and weakness of all intrinsic right hand muscles, more so of the thenar muscles, and hypesthesia along the ulnar aspect of the hand and forearm. EMG, which showed a severe chronic axon loss lower trunk brachial plexopathy with minimal fibrillations, was typical for classic neurogenic TOS. Chest and cervical spine X-rays and MRI of the cervical spine were normal. A supraclavicular exploration confirmed the absence of a cervical rib or band. The lower trunk was thickened under the scalenus anticus which was sectioned. Neurolysis was also done. She was advised to abandon swimming. A clinical and EMG follow-up 2.5 years later showed no significant changes. This is the first case of true neurogenic TOS caused by scalenus anticus compression occurring in a competitive swimmer.

Adolescent↗
PubMed1995

Functional cDNA clones of the human respiratory syncytial (RS) virus N, P, and L proteins support replication of RS virus genomic RNA analogs and define minimal trans-acting requirements for RNA replication.

The RNA-dependent RNA polymerase of human respiratory syncytial (RS) virus was expressed in a functional form from a cDNA clone. Coexpression of the viral polymerase (L) protein, phosphoprotein (P), and nucleocapsid (N) protein allowed us to develop a system for expression and recovery of replicable RS virus RNA entirely from cDNA clones. cDNA clones of the N, P, and L genes were constructed in pGEM-based expression plasmids and shown to direct expression of the appropriate polypeptides. Two types of RS virus genomic RNA analogs were expressed from an intracellular transcription plasmid that directed the synthesis of RNAs with defined 5' and 3' ends. One analog included the authentic 5' and 3' termini of the genome, and the second contained the authentic 5' terminus and its complement at the 3' terminus as found in copyback defective interfering RNAs of other negative-strand RNA viruses. Both types of genomic analogs were encapsidated and replicated in cells expressing the RS virus N, P, and L proteins. Omission of any of the three viral proteins abrogated replication, thereby defining the N, P, and L proteins as the minimal trans-acting proteins required for RNA replication. This system has the advantages that expression occurs at a level sufficient to allow direct biochemical analysis of the products of RNA replication and that neither the use of reporter genes nor wild-type RS helper virus is required. These features allow analysis of both cis- and trans-acting factors involved in the control of replication of RS virus RNA.

Cell Line↗
PubMed1995

Epidermal growth factor (EGF) receptor carboxy-terminal domains are required for EGF-induced glucose transport in transgenic 3T3-L1 adipocytes.

Insulin-stimulated glucose transport in adipocytes is mediated by the insulin receptor. To ascertain whether a related receptor could also trigger this response, the epidermal growth factor (EGF) receptor (EGFR) was introduced into adipocytes. 3T3-L1 fibroblasts were infected by a retroviral construct encoding either the full-length (WT) or a carboxy-terminal truncated (c'973) human EGFR; truncation of the amino acids distal to 973 removes all autophosphorylation motifs. After selection and conversion to adipocytes, the level of EGFR expression was retained in infectant adipocytes (150,000 and 250,000/cell, respectively), but not in the parental 3T3-L1 adipocytes (< 5000/cell). WT and c'973 EGFR exhibited ligand-dependent tyrosine kinase activity and stimulated mitogen-activated protein kinase activity equivalently; neither phosphorylated insulin receptor substrate-1. WT EGFR, but not c'973 EGFR, underwent ligand-induced autophosphorylation. EGF did not stimulate tyrosine phosphorylation of the insulin receptor or insulin receptor substrate-1. EGF had a minimal effect on glucose transport by parental 3T3-L1 adipocytes. Glucose transport in the WT EGFR adipocytes was stimulated equivalently by insulin and EGF; exposure to insulin and EGF in combination did not result in augmented transport. Glucose transport in the c'973 EGFR adipocytes was stimulated by insulin, but not by EGF. GLUT4 was translocated to the plasma membrane to a similar extent in response to insulin or EGF in the WT EGFR adipocytes; only insulin caused a significant GLUT4 translocation in the parental or c'973 EGFR adipocytes. These data suggest that the insulin and EGF signaling pathways that lead to glucose transport converge in these adipocytes down-stream of the insulin receptor, and that activation of this pathway requires signaling motifs in the carboxy-terminus of the EGFR. This model system represents a novel approach with which to dissect signal transduction pathways in terminally differentiated adipocytes.

3T3 Cells↗
PubMed1995

The posterior surgical approach to the cervical spine.

This article reviews the indications for, and the technique of, posterior operations on the cervical spine. Cervical hemilaminectomy and laminectomy are discussed, including diagnosis, nonoperative treatment, and results and complications of surgery. Laminectomy for other conditions, cervical trauma, and cervical fusion are reviewed also.

Cervical Vertebrae↗
PubMed1995

Stearate inhibits human tumor cell invasion.

Tumor growth and metastasis are affected by changes in membrane lipid composition, however, little is known regarding the role of specific fatty acids in these pathological events. We investigated the effects of the long-chain saturated fatty acids (LCSFA), myristate (C14:0), palmitate (C16:0) and stearate (C18:0) on two key steps of metastasis: cell adhesion and invasion into extracellular matrix (ECM). Using a new 72-hour ECM (Amgel) invasion assay, we demonstrated that the exposure of highly invasive human fibrosarcoma HT-1080 cells to 0.3 mM stearate inhibited their ability to traverse Amgel by 59.4 +/- 8%. In contrast, treatment of tumor cells with 0.3 mM myristate or palmitate had no effect. Microscopic examination revealed a time-dependent inhibition of tumor cell adhesion to the Amgel in the stearate-treated group. Cell adhesion assays further showed a series of rapid morphological cellular changes, i.e. retraction of processes, cell rounding, and subsequent detachment in the presence of stearate. These morphological events were both dose- and time-dependent. Viability of LCSFA-treated cells exceeded 80%. This stearate inhibition of HT-1080 cell adhesion was also observed with two other invasive human tumor cell lines. Similar treatment of HT-1080 cell with the unsaturated long-chain fatty acid oleate (C18:1) did not alter tumor cell adhesiveness. In contrast, nontransformed human fibroblasts (Hs-68) were unaffected by stearate treatment. This inhibition of cell adhesion by stearate was determined to be dependent upon laminin-containing ECM. Pretreatment of HT-1080 cells with stearate dramatically abolished their capacity to attach to laminin but not to collagen type IV or fibronectin matrices. Immunofluorescent studies with anti-beta 1 integrin receptor and antivinculin antibodies demonstrated beta 1 subunit and vinculin colocalization to focal adhesions in untreated HT-1080 cells adherent to laminin, in contrast to stearate-treated tumor cells. Further, stearate-induced changes were shown to be functionally coupled to integrins as an anti-beta 1 antibody markedly diminishes the adhesive ability of tumor cells to laminin. These data demonstrate stearate inhibits tumor cell adhesion, and therefore invasion, via a mechanism involving a laminin integrin receptor.

Cell Adhesion↗
PubMed1994

The interaction of calmodulin and polylysine as studied by 1H NMR spectroscopy and sedimentation equilibrium centrifugation.

The effects of polylysine on calmodulin were assessed using 1H NMR and sedimentation equilibrium centrifugation. Sedimentation equilibrium centrifugation measurements demonstrated that calmodulin associates with polylysine at calmodulin-polylysine molar ratios ranging from 10:1 to 2.5:1 and when polylysine is increased above the molar ratio of 1:1 a precipitate is formed. At a 1:2.5 calmodulin:polylysine molar ratio, 75% of the calmodulin precipitates from the solution and virtually no polylysine is present in the precipitate. 1H NMR studies of the aromatic region of calmodulin identified chemical shifts of three peaks at a calmodulin:polylysine molar ratio of 1:1. These studies suggest that polylysine associates with calmodulin in aqueous solution and can alter the structure of calmodulin to cause calmodulin self-aggregation.

Animals↗
PubMed1994

Calmodulin concentrated at the osteoclast ruffled border modulates acid secretion.

Osteoclasts mediate acid dissolution of bone for maintenance of serum [Ca2+] and for replacement of old bone in terrestrial vertebrates. Recent findings point to the importance of intracellular signals, particularly Ca2+, in osteoclast regulation. However, acid degradation of bone mineral subjects the osteoclast to uniquely high extracellular [Ca2+]. We hypothesized that this high calcium environment would affect calcium signalling mechanisms, and studied the calcium binding regulatory protein, calmodulin, in the osteoclast. Avian osteoclast bone resorption was inhibited 30% at 1 microM and 90% at 7 microM by the calmodulin antagonist trifluoperazine. Osteoclast bone attachment was not affected by 10 microM trifluoperazine. Quantitative immunofluorescence using fluorescein-labelled calmodulin monoclonal antibody showed a severalfold increase of calmodulin concentration in bone attached relative to plastic attached osteoclasts. Western blots confirmed this, showing two to threefold increased osteoclast calmodulin per milligram of cell protein in 3-day bone-attached vs. nonattached cells. Scanning confocal microscopy showed calmodulin polarization to areas of bone attachment. Electron micrographs with 9 nm colloidal gold labelling showed calmodulin in the acid secreting ruffled membrane. ATP-dependent acid transport in osteoclast membrane vesicles was inhibited by the calmodulin antagonist calmidazolium. This effect was reversed by addition of excess calmodulin, showing that the inhibition is specific. Vesicle acid transport inhibition reflects an approximately fourfold shift in the apparent Km for ATP of vesicular acid transport in the presence of the calmodulin antagonist. We conclude that calmodulin concentration and distribution is modified by bone attachment, and that osteoclastic acid secretion is calmodulin regulated.

Acids↗
PubMed1994

Pantothenic acid deficiency detection in rainbow trout (Oncorhynchus mykiss).

Rainbow trout averaging 150 g were fed semipurified diets supplemented or not supplemented with pantothenic acid. After 16 wk of feeding, fish fed the deficient diet had reduced feed intake. At 28 wk, supplemented fish weighed > 600 g, whereas deficient fish weighed 425 g. Deficient fish became anorectic and listless at 25 wk and began to die at 28 wk. Histological examination of gill tissue revealed fused gill lamellae in the deficient fish, confirming pantothenic acid deficiency. At 4-wk intervals, samples of fish were taken from each group for determination of free and total concentrations of pantothenic acid in gills, liver, heart and erythrocytes by RIA. Concentrations of bound pantothenic acid, calculated by difference, did not differ between dietary treatment groups except in gills. Free pantothenic acid concentration in gills and heart were significantly lower in fish fed the deficient diet than in those fed the complete diet after 4 wk of feeding and remained so thereafter. Free pantothenic acid concentrations in the livers of deficient fish were significantly different from those in sufficient fish after 16 wk of feeding. Erythrocyte free pantothenic acid concentrations of deficient fish were significantly different from initial values at 8 wk and beyond. Using free pantothenic acid concentrations in erythrocytes allows detection of pantothenic acid deficiency in fish that are too valuable to permit destructive sampling techniques, such as broodstock and threatened or endangered species.

Animals↗