Recording of spindle afferent discharge during hindlimb movements in spinalized turtles

The feasibility of spindle afferent recording during naturally or electrically induced hindlimb movements is demonstrated in the case of spinalized, decapitated turtles. Since these recordings are obtained from fine filaments of exposed dorsal roots, it is possible for the experimenter to select the afferents of interest. This feasibility, together with the fact that spinally generated movements are readily exhibited, make the turtle an attractive animal for the study of spinal motor control mechanisms.     

Evaluation of image-diagnosing methods of enlarged parathyroid glands in chronic renal failure

Three noninvasive image-diagnosing methods, computed tomography (CT), scintigraphy with²⁰¹T1C1 and^99mTcO_h4 ^–, and ultrasonography (US), were preoperatively performed on 50 patients with chronic renal failure and secondary hyperparathyroidism who underwent total parathyroidectomy and parathyroid autograft. The detection rates of the 3 methods on the 191 excised parathyroid glands were compared according to weight and location. CT detected 57.1% of all glands and 78.6% of 103 glands weighing over 500 mg. Scintigraphy detected 51.8% and 75.7%, and US detected 42.4% and 53.4%, respectively. The detection rate of upper glands was best with CT at 58.9% and 89.1%; that of lower glands was best with scintigraphy at 65.3% and 80.4%. Although the combination of the 3 methods diagnosed 69.6% and 89.5%, CT and scintigraphy, the best 2 combinations, visualized 67.5% and 88.3%.

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Resumen Tres métodos diagnósticos no invasivos, la tomografía computadorizada (TC), la centelleografía con²⁰¹T1C1 y^99mTcO₄ y la ultrasonografía (US) fueron realizados preoperatoriamente en 50 pacientes con falla renal crónica e hiperparatiroidismo secundario sometidos a paratiroidectomía y autotransplante paratiroideo. Las tasas de detección de los 3 métodos fueron comparados sobre las 191 glándulas paratiroideas resecadas en relación a los pesos y a los sitios de ubicación. La TC detectó el 57.1% del total de glándulas y el 78.6% de aquellas glándulas (103) con pesos superiores a 500 mg. La centelleografía detectó 51.8% y 75.7%, y la US 42.4% y 53.4% respectivamente. La tasa de detección para las glándulas superiores fue optima con TC, con 58.9% y 89.1%; la de las glándulas inferiores fue óptima con centelleografía, con 65.3% y 80.4%. Aunque la combinación de los 3 metodos diagnosticó el 69.6% y 89.5%, la TC y la centelleografía, la mejor de las combinaciones, visualizó el 67.5% y el 88.3% respectivamente.

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Résumé Trois méthodes d'imagerie non invasives, la tomodensitométrie, la scintigraphie (avec T1C1²¹⁰ et TcO₄ ^99m), et l'ultrasonographie ont été pratiquées avant l'intervention chez 50 malades qui présentaient une insuffisance rénale chronique compliquée d'hyperparathyroïdisme secondaire et qui furent traités par parathyroïdectomie totale et autogreffe parathyroïdienne. Les taux de détection de ces 3 méthodes concernant 191 glandes parathyroïdes réséquées ont été évalués en fonction du poids et du siège des lésions. La tomodensitométrie a permis de découvrir 57.1% de toutes les glandes et 78.6% des glandes dont le poids dépassait 500 mg; la scintigraphie 51.8% et 75.7%; l'ultrasonographie 42.4% et 53.4%. Le taux de détection des glandes supérieures fut plus élevé avec la tomodensitométrie: 58.9% et 89.1%; celui des glandes inférieures le fut avec la scintigraphie: 65.3% et 80.4%. Si la combinaison des 3 méthodes permet le diagnostic dans 69.6% et 89.5% des cas la tomodensitométrie associée seulement à la scintigraphie donne des résultats très voisins, les taux respectifs étant de 67.5% et de 88.3%.

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Presented at the International Association of Endocrine Surgeons in Paris, September 1985.     

Activation of protein kinase C and specific phosphorylation of a Mr 90,000 membrane protein of promotable BALB/3T3 and C3H/10T1/2 cells by tumor promoters

The activation of protein kinase C and protein phosphorylation by tumor promoters were examined using quiescent cultures of BALB/3T3 and C3H/10T1/2 cells, because in these cells tumor promoters enhance chemically induced transformation and also induce DNA synthesis and ornithine decarboxylase. The cytosol and membrane fractions were partially purified, and the activity of protein kinase C was assayed. In quiescent cells, protein kinase C activity was found only in the cytosol fraction. Treatment with 100 ng of 12-O-tetradecanoylphorbol-13-acetate or teleocidin B per ml caused rapid translocation of protein kinase C from the cytosol to the membrane fraction. The activity in the cytosol disappeared almost completely after 15 min when the activity in the membrane reached a peak. The membrane activity gradually decreased to the control level after 6 h, while no activity reappeared in the cytosol within 6 h. Under these circumstances, a membrane protein with a molecular weight of 90,000 and pl of 4.0-4.4 (termed p90) was specifically phosphorylated, possibly by the activated protein kinase C, in both cell-free and intact-cell systems. On treatment of quiescent BALB/3T3 cells with 100 ng of 12-O-tetradecanoylphorbol-13-acetate, p90 phosphorylation increased 2-fold in 1 min, reaching a peak in 15 min of 3.4-fold the initial value. The phosphorylation of p90 increased with increase in the concentrations of 12-O-tetradecanoylphorbol-13-acetate between 0.1 and 10 ng/ml and reached a plateau at 10 ng/ml. p90 phosphorylation also occurred on exposure of the cells to non-phorbol ester tumor promoters (mezerein and teleocidin B) and growth factors, such as platelet-derived growth factor and fibroblast growth factor. p90 was not immunoprecipitated by antibody against the insulin receptor. Phosphorylation of p90 occurred at a serine residue. The present study suggests that activation of protein kinase C and phosphorylation of p90 by it are early events leading to tumor promotion.     

In vivo observation of crystalline lens changes in the early post-vitrectomy stage]

Crystalline lens changes of 17 cases of eye undergoing simple vitrectomy were observed from the post-operative 1st to 21st month. Changes in the crystalline lenses were detected through a slitlamp microscope or by methods of image analysis, the Opacity Lensmeter and the laser scattering spectroscopy. Increases of the scattering light intensity of the anterior and posterior deep cortical layers were observed from the early post-operative stage in 9 cases. Seven cases progressed to nuclear opacification during the observation period, however, one case showed no nuclear changes even at the 12 post-operative month. No relationships were observed between the early cortical changes and surgical invasion, patient age, or cause of vitreous opacification. Quantitative evaluation by image analysis revealed early post-operative crystalline lens changes in cases undergoing vitreous surgery.     

Bronchial hyperresponsiveness to acetylcholine during acute pulmonary congestion in guinea pigs]

To understand the precise mechanism of bronchial hyperresponsiveness in patients with congestive heart failure, we studied the effect of mild pulmonary congestion on bronchial responsiveness to inhaled acetylcholine (ACh) in guinea pigs. We induced mild pulmonary congestion by inflation of a balloon placed in the left atrium, and maintained the left atrial pressure (Pla) at 10 mmHg for 30 minutes with continuous monitoring of lung resistance (RL) and dynamic compliance (Cdyn). Furthermore, we determined the provocative concentration of ACh producing 100% increase in RL (PC100-ACh), before and during balloon inflation. In animals with propranolol pretreatment, but not in animals without propranolol pretreatment, mild pulmonary congestion caused slight increase in RL (N.S.) and significant decrease in Cdyn (p less than 0.01) and PC 100-ACh (p less than 0.01). Cutting of bilateral vagal nerves partially inhibited the decrease of PC100-ACh, but pretreatment with either phenoxybenzamine, indomethacin, AA-861 or OKY-046 had not effect. These results suggest that blockade of beta-adrenergic receptors and the vagal reflex, but not of alpha-adrenergic receptors or arachidonates, contributes to bronchial hyperresponsiveness during acute pulmonary congestion.     

Fluid-fluid levels in cavernous hemangioma of soft tissue

Five cases of cavernous hemangioma with fluid-fluid levels on magnetic resonance imaging and/or computed tomography are reported. The signal characteristics were those of blood and histological analysis of the fluid-fluid levels showed that they were blood-filled cavities in the tumor. Although this finding itself is not specific, it may help in confirming the diagnosis of cavernous hemangioma.     

Role of Ca2+ on vasoactive intestinal peptide-induced glucose and adenosine 3',5'-monophosphate production in the isolated perfused rat liver.

Livers from fed rats (180-240 g) were perfused noncyclically with a hemoglobin-free medium in vitro to determine whether vasoactive intestinal peptide (VIP) increases hepatic glucose production through a cAMP- or a Ca(2+)-dependent mechanism. Glucose output did not increase, but cAMP increased maximally during 10(-9) M VIP infusion. When VIP was perfused at 10(-8) M or more, glucose output increased dose dependently, whereas cAMP increased only a little during the VIP infusion, but increased greatly after the infusion. When Ca2+ was excluded from the perfusate, glucose output produced by 10(-8)-10(-7) M VIP was only 40% of that observed in the Ca(2+)-containing perfusion, and the increase in cAMP was abolished almost completely. By adding 10(-7) M A23187 for 10 min during the infusion of 10(-9) M VIP, cAMP, which increased with VIP alone, decreased during the A23187 infusion and increased again after the cessation of the A23187 infusion, whereas glucose output increased during the A23187 infusion. These results were similar to those observed with higher concentrations of VIP. When 10(-4) M isobutylmethylxanthine and 10(-8) M VIP were infused concurrently, cAMP increased rapidly during the infusion and decreased after the infusion. In conclusion, 1) glycogenolysis is produced by VIP through a Ca(2+)-dependent mechanism, rather than a cAMP-dependent one; and 2) the restriction of cAMP accumulation during the infusion of high concentrations of VIP is caused by Ca(2+)-induced phosphodiesterase activation.