Diminished expression of the α5β1 integrin (fibronectin receptor) by invasive clones of a human follicular thyroid cancer cell line

Altered adhesion plaques have been observed in transformed cell lines and are associated with enhanced metastatic potential. The prototypical adhesion plaque is formed by 51 fibronectin receptors (FnRs) interacting with the cellular actin network. We have found differences in the actin networks of noninvasive (FTC-133) and invasive (FTC-236, FTC-238) clones of a human follicular thyroid cancer cell line. Furthermore, thyroid-stimulating hormone (TSH) induces stress fibers in FTC-133. In order to investigate differences in adhesion plaques, expression of fibronectin (FN) and its receptor by these cells was analyzed. For these studies FTC-133, FTC-236, and FTC-238 were cultured in serum-depleted DME-H21 medium for 24 hours before the addition of TSH 30 mU/ml. No quantitative differences were noted in FN expression on Western blot in either the conditioned medium or cellular extracts. Western blots and immunohistochemical studies indicated that TSH induced secretion of FN only in FTC-133. Flow cytometry with an 5 antibody demonstrated a 52% and 45% reduction (p<0.01) in expression of FnR by FTC-236 and FTC-238, respectively, compared to FTC-133; this finding was supported by immunohistochemistry results. TSH treatment did not alter FnR expression. From these studies, we conclude that invasive clones of FTC decrease their expression of FnRs without changing their expression of FN. Furthermore, TSH treatment may promote FN secretion by FTC-133, although it does not seem to affect FnR or absolute FN expression. The diminished expression of FnR adhesion plaques may enhance metastatic potential in some follicular thyroid cancers.

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Resumen Se han observado placas adhesivas alteradas en líneas celulares transformadas en asociación con un potencial metastásico incrementado. La prototípica placa adhesiva se forma por la interacción de receptores 5-1 con la trama celular de actina. Hemos encontrado diferencias en las tramas de actina en clones no invasivos (FTC-133) e invasivos (FTC-236, FTC-238) de una línea celular de cáncer folicular de tiroides.Además, la TSH induce líneas de estrés en FTC-133. Con el objeto de investigar las diferencias en las placas adhesivas, se hizo el análisis de la expresión de fibronectina (FN) y sus receptores en tales células.Para estos estudios se hizo el cultivo de FTC-133, FTC-236 y FTC-238, en sueros depletados de DME-H21 por 24 horas anteriores a la adición de 30 mU/ml TSH por 24 horas. No se observaron diferencias cuantitativas en la expresion de FN o en el Western blot ni en los medios condicionados ni en los extractos celulares. Los Western blots y los estudios inmunohistoquímicos indicaron que la TSH induce la secreción de FN sólo en FTC-133. La citometría de flujo con un anticuerpo 5 demostró una reducción de 52% y 45% (p<0.01) en la expresión de FnR por FTC-236 y FT-238, respectivamente, en comparación con FTC-133; este hallazgo fue verificado por inmuno-histoquímica. El tratamiento con TSH no alteró la expresón FnR. Con base en estos estudios, es nuestra conclusión que los clones invasivos de FTC disminuyen la expresión de FnR sin cambiar su expresión de FN. Además, el tratamiento con TSH puede promover la secreciòn de FN por FTC-133, aunque no parece afectar la expresión de FnR o la expresión absoluta de FN. Esta expresión disminuída de las placas adhesivas FnR puede incrementar el potencial metastásico en algunos cánceres foliculares de tiroides.

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Résumé On a observé des altérations des plaques d'adhésion dans certaines lignées cellulaires transformées, et celles-ci semblent être associées à un potentiel métastatique augmenté. La plaque d'adhésion prototypique est formée par des récepteurs 51 de fibronectine (FnR) qui agissent sur le réseau cellulaire d'actine. Nous avons trouvé une différence entre les réseaux d'actine des clones noninvasifs (FTC-133) et invasifs (FTC-236, FTC-238) des lignées cellulaires dans le cancer folliculaire de la thyroïde chez l'homme. La TSH induit des fibres de stress dans le FTC-133. Afin d'évaluer les différences dans les plaques d'adhésion, l'expression de la fibronectine (FN) et de son récepteur ont été analysées. Pour ces études, les clones FTC-133, FTC-236 et FTC-238 ont été mis en culture dans le milieu DME-H21 dépourvu en sérum pendant 24 heures avant l'addition de 30 mU/ml de TSH/24 heures. II n'y avait aucune différence quantitative dans l'expression FN sur Western blot que ce soit sur le milieu ainsi conditionné ou sur les extraits cellulaires. Les Western blots et les études immunohistochimiques ont indiqué que la TSH n'induisait la sécrétion de FN que dans la lignée FTC-133. La cytométrie de flux avec l'anticorps 5 a démontré une réduction respectivement de 52% et de 45% (p<0.01) dans l'expression de FnR par les clones FTC-236 et FTC-238, comparé au FTC-133. Cette donnée a été confirmée par l'immunohistochimie. A partir de ces études, nous concluons que les clones d'invasion de FTC diminuent leur expression en FnR sans changer leur expression de FN. De plus, un traitement par la TSH peut induire la sécrétion de FN par le clone FTC-133 alors qu'il ne semble pas influencer le FnR ou l'expression FN. L'expression diminuée des plaques d'adhésion FnR semble potentialiser les métastases dans certains cancers de la thyroïde.

     

Quality down under: if we knew then what we know now

Australian health care's approach to performance improvement increasingly includes the use of total quality management (TQM) and its component principles and methods. Implementation experiences have confirmed TQM's relevance in the Australian health care environment, senior management's pivotal role, and the range of factors required for success. Ways of influencing executive behavioral change and streamlining implementation are discussed.     

N-CAM promotes recovery in injured nerves

The neural cell adhesion molecule, N-CAM, makes critical contributions to the development of the nervous system. It mediates the stability of homophilic adhesion in embryonic neurons and participates in morphologic differentiation. The goal of these studies was to determine N-CAM contributions to nerve regeneration and recovery of function in two species with an excised segment of sciatic nerve. N-CAM was isolated from embryonic brains, affinity purified and admixed in collagen gel for administration. Recovery was compared 30 days after surgery for two types of N-CAM delivery: entubulization versus direct application. For control nerves, tubes contained gel only. In preliminary chicken studies, latency of nerve responses was measured to demonstrate N-CAM's ability to improve upon spontaneous recovery. In subsequent studies of rodent nerves, the direct application of N-CAM significantly improved recovery in evoked nerve response amplitude, number of regenerated axons and behavioral activity. Results demonstrate N-CAM's ability to augment nerve regeneration and suggest a potential for therapeutic use.     

Functional haplodiploidy: a mechanism for the spread of insecticide resistance in an important international insect pest.

The coffee berry borer, Hypothenemus hampei, is the most important insect pest of coffee worldwide and has an unusual life history that ensures a high degree of inbreeding. Individual females lay a predominantly female brood within individual coffee berries and because males are flightless there is almost entirely full sib mating. We investigated the genetics associated with this interesting life history after the important discovery of resistance to the cyclodiene type insecticide endosulfan. Both the inheritance of the resistance phenotype and the resistance-associated point mutation in the gamma-aminobutyric acid receptor gene Rdl were examined. Consistent with haplodiploidy, males failed to express and transmit paternally derived resistance alleles. Furthermore, while cytological examination revealed that males are diploid, one set of chromosomes was condensed, and probably nonfunctional, in the somatic cells of all males examined. Moreover, although two sets of chromosomes were present in primary spermatocytes, the chromosomes failed to pair before the single meiotic division, and only one set was packaged in sperm. Thus, the coffee berry borer is "functionally" haplodiploid. Its genetics and life history may therefore represent an interesting intermediate step in the evolution of true haplodiploidy. The influence of this breeding system on the spread of insecticide resistance is discussed.     

Isovelocity investigation of the lengthening behaviour of the erector spinae muscles

The purpose of this study was to investigate the force-velocity (F/) relationship for the erector spinae muscles in submaximal activation movements, with particular attention to their response during lengthening movements and at lower shortening contraction velocities. Dynamic models that predict lower back muscle forces require reasonable representations of the modulating effect of instantaneous velocity. Ten males were observed performing trunk flexion and extension in the sagittal plane under constant load. Contraction velocities were measured as the first derivative from a devise sensitive to changes in spine curvature, and controlled by a visual feedback system while a constant load was applied through a chest harness. The erector spinae exhibited a yielding phenomenon which causes an abrupt drop in force during constant velocity stretching under constant, submaximal, stimulation. The findings were consistent with previous isovelocity muscle lengthening experiments. Yielding appeared dependent on the level of load/activation supporting the theory of a state-variableF/ relationship. The eccentric behaviour of the lower erectors (L3) seemed independent of velocity and length, while that of the upper erectors (T9) showed a dependence on length. At lower concentric velocities, concavity in torque-velocity curves was noted after a threshold velocity. The findings of this study strongly reinforce the notion that theF/ length relationship is not a continuous hyperbolic relationship during muscle shortening and that the commonly modelled force augmentation effect of lengthening is incorrect, at least for submaximal activation of the extensors of the lower back.     

The distribution of systemically administered [3H]-paclitaxel in rats: a quantitative autoradiographic study

Paclitaxel is an important agent in the treatment of many common malignancies. Although the symptomatic peripheral neuropathy caused by this drug is its principal nonhematologic toxicity, little is known about the distribution of paclitaxel within the peripheral or central nervous system following systemic administration. In order to study paclitaxel's distribution in neural and extraneural tissues, adult Sprague-Dawley rats were sacrificed 2 h after a tail vein injection of [³H]-paclitaxel (0.03 mg/kg, 250 Ci/rat). Samples of lung, heart, liver, spleen, kidney, skeletal muscle, brain, spinal cord, dorsal root ganglion, and peripheral nerve were then removed and snap-frozen. These tissues were sectioned at 10 m in a cryostat and exposed to autoradiography film for 2 weeks. The distribution and concentrations of [³H]-paclitaxel in plasma, urine and cerebrospinal fluid were also determined using liquid scintillation spectrometry. [³H]-Paclitaxel concentrations (and organ/plasma concentration ratios) in plasma, urine and cerebrospinal fluid were 2.6 nM (1), 38 nM (15) and 0.7 nM (0.3), respectively. A relatively homogeneous distribution of [³H]-paclitaxel was observed in liver [412 nM (151)], spleen [351 nM (133)], heart [319 nM (117)], lung [268 nM (93)] and muscle [69 nM (26)]. Higher concentrations of [³H]-paclitaxel were noted in the portal triads [869 nM (361)], glomeruli [797 nM (304)], and renal medulla [961 nM (363)], which may reflect biliary excretion and glomerular filtration. A high concentration of [³H]-paclitaxel was also noted in the choroid plexus [432 nM (167)], but [³H]-paclitaxel was not detected in the brain parenchyma, spinal cord, dorsal root ganglion, peripheral nerve, or the testicles. The pathogenesis of paclitaxelinduced neurotoxicity remains obscure given its limited distribution in the nervous system. In addition, these results suggest that systemically administered paclitaxel is not likely to be effective for the treatment of malignancies in the testes or the nervous system.     

Parent Expectations of the School Health Program in Nebraska

This article presents findings from the first phase of a comprehensive evaluation plan for the school health program in Nebraska public schools. The evaluation utilized the Targeting Outcomes of Programs (TOP) framework to gather parents' perspectives about the benefits of the school health program, and a ranking of important health activities and role providers. A survey was distributed to 1,200 parents randomly selected from 60 school districts. Of these, 450 (38%) were returned: 96% supported funding of health programs; 88% believed families benefited from school health; 92% viewed the health programs as "essential" to the educational mission; 64% preferred a ratio of 1 nurse/500 students; and 89% believed all students needed access to a professional school nurse. The nurse was the only clearly defined role in the health program and had activities rated as "extremely important." Results were reported to the Nebraska legislature for support of state funding for school health nursing.     

Voltage-activated sodium channels amplify inhibition in neocortical pyramidal neurons

Inhibitory postsynaptic potentials (IPSPs) in neocortical pyramidal neurons are increased in duration and amplitude at depolarized membrane potentials. This effect was not due to changes in the time course of the underlying synaptic current. The role of postsynaptic voltage-activated channels was investigated by mimicking the voltage change that occurs during an IPSP with current injections. The peak and integral of these 'simulated' IPSPs increased during depolarization of the membrane potential in a tetrodotoxin-sensitive manner. This amplification presumably occurs as the hyperpolarization associated with IPSPs turns off sodium channels that are tonically active at depolarized membrane potentials. IPSP amplification increased the ability of IPSPs to inhibit action potential firing and promoted IPSP-induced action potential synchronization.     

Interrater reliability levels of multiple clinical examiners in the evaluation of a schizophrenic patient: quality of life, level of functioning, and neuropsychological symptomatology

Sir Ronald Fisher used a single-subject design to derive the concepts of appropriate research design, randomization, sensitivity, and tests of statistical significance. The seminal work of Broca demonstrated that valid and generalizable findings can and have emerged from studies of a single patient in neuropsychology. In order to assess the reliability and/or validity of any clinical phenomena that derive from single subject research, it becomes necessary to apply appropriate biostatistical methodology. The authors develop just such an approach and apply it successfully to the evaluation of the functioning, quality of life, and neuropsychological symptomatology of a single schizophrenic patient.     

Mycophenolate mofetil and tacrolimus as primary maintenance immunosuppression in simultaneous pancreas-kidney transplantation: initial experience in 50 consecutive cases

BACKGROUND: The current study examines the use of mycophenolate mofetil (MMF) and tacrolimus as primary immunosuppression in simultaneous pancreas-kidney (SPK) transplantation. In addition, analyses of the rates of conversion from one immunosuppressive agent to another, and its subsequent consequences with respect to outcomes were determined. Quality of graft function, infections, and effect on preexisting essential hypertension are also described. METHODS: Immunosuppression consisted of quadruple therapy with antithymocyte globulin induction, tacrolimus, MMF, and prednisone. Patient and graft survival and rejection rates in 50 consecutive SPK recipients, followed for a minimum of 3 months and a mean of 14 months (range: 3-34 months), are described. RESULTS: Thirty-nine of 50 (78%) patients tolerated the MMF/tacrolimus combination long-term (mean duration of follow-up: 14+/-7 months). Nine of 50 patients (18%) were converted to Neoral, and 4 patients were converted to azathioprine as a substitute for MMF. The 2-year actuarial patient, kidney, and pancreas survival rates were 97.7%, 93.3%, and 90.0%, respectively. At 6 months after transplant, the overall incidence of acute rejection was 16%. There was a statistically significant (P< or =0.04, Cox-Mantel test) difference in the rate of rejection associated with conversion to Neoral. The incidence of rejection 6 months after transplant in the group maintained on MMF/tacrolimus was 10.2% vs. 44.4% in the group converted to Neoral (P< or =0.04, Cox-Mantel test). Overall, the 1-year actuarial cumulative incidence of tissue-invasive cytomegalovirus disease was 6.6%. There were no cases of fungal infections or post-transplant lymphoproliferative disorders. One patient developed Kaposi's sarcoma 10 months after transplant. With respect to hypertensive disease, 60% (12/20) of the patients who required pharmacologic control of blood pressure before transplant were off all antihypertensive medications at 1 year after transplant. An additional 20% (4/20) of patients had a reduction in the number of medications required to control blood pressure at 1 year after transplant. CONCLUSIONS: We conclude that the combination of MMF and tacrolimus as primary immunosuppression for SPK transplantation results in excellent patient and graft survival rates, a very low rate of acute rejection, and low rates of infection and malignancy.