Pulmonary maturation in the hypophysectomised ovine fetus. Differential responses to adrenocorticotrophin and cortisol

Pulmonary maturation in six ovine fetuses hypophysectomised by a cryosurgical method at 0.7-0.8 of pregnancy and delivered by hysterotomy at 152.2 +/- 2.9 (SD) days was compared with that in seven control fetuses delivered at 144.5 +/- 3.5 days. Both the wet and the dry weight of the lungs was less in the hypophysectomised fetuses but total DNA did not differ. Lung volumes at 40 cm of H2O and at 5 cm of H2O on deflation in hypophysectomised fetuses were less than one-third that of controls. Saturated phosphatidylcholine, as an estimate of surfactant, was lower in both lung tissue and lavage fluid. A further group of hypophysectomised fetuses was infused intravenously either with cortisol at 1 mg/h for 72 h (n = 6), or with ACTH1-24 at 5 microgram/h for 84 h (n = 6) before delivery at 155.0 +/- 2.1 days and 154.2 +/- 3.9 days respectively. None of the indices of pulmonary maturation in the cortisol-treated fetuses differed from those in untreated hypophysectomised fetuses whereas values for lung volumes at 40 and 5 cm of H2O in ACTH-treated fetuses were more than twice those of untreated hypophysectomised fetuses and did not differ significantly from controls. In addition, the amount of saturated phosphatidylcholine in lavage fluid was greater in ACTH-treated fetuses (0.13 +/- 0.10 mg/g) than in untreated hypophysectomised fetuses (0.04 +/- 0.48 mg/g). Lung volume at 40 cm of H2O in four fetuses that were thyroidectomised at the time of hypophysectomy responded to ACTH as in hypophysectomised fetuses with intact thyroids but other indices were unaffected. We conclude that hypophysectomy retards pulmonary maturation in fetal sheep. Since ACTH restores distensibility and increases alveolar surfactant in the absence of other pituitary hormones it is likely that ACTH has a major role in lung maturation. The lack of response to cortisol suggests that the effect of ACTH is not mediated only by circulating cortisol.     

Modified oscillation behavior and decreased D-3-hydroxybutyrate dehydrogenase activity in diabetic rat liver mitochondria

One month after induction of diabetes in adult white rats with streptozotocin or 4–10 months after its induction by pancreatectomy (in every case glycemia was over 3 g/liter), the following alterations were observed in liver mitochondria: (a) a decrease of amplitude and an increase of the damping factor of volume oscillations induced by potassium ions and valinomycin; (b) a 50% decrease of d-3-hydroxybutyrate dehydrogenase (HBD) activity in mitochondria disrupted by repeated freeze-thawing; (c) a similar decrease in the rate of d-3-hydroxybutyrate oxidation by intact mitochondria; (d) a significant increase of cytochrome oxidase activity and cytochrome aa₃ content. Measurement of succinate dehydrogenase and NADH dehydrogenase activity, the cytochrome b, c₁, and c content, and the P:O ratio for mitochondria oxidizing d-3-hydroxybutyrate did not reveal significant differences between control and diabetic rat mitochondria. In the streptozotocin-injected rats, the variation of HBD activity and the modification of the mitochondrial oscillation pattern were time-dependent phenomena, both effects reaching their maximal expression about 1 month after the onset of diabetes. The variation of HBD activity followed a biphasic course, since it rose to above the control level during the first 2 weeks of diabetes, then fell progressively to about half the control value after the third week. Treatment of diabetic rats with NPH insulin (5 IU twice daily, for 3 days, reinforced by the same dose 45 min before sacrifice) restored the mitochondrial oscillation pattern, HBD activity, and rate of d-3-hydroxybutyrate oxidation by intact mitochondria to their normal values.     

A limnological reconnaissance of Lake Tebenquiche,Salar de Atacama,Chile

A number of expeditions to the area of Salar de Atacama, Chile, 68° 15'W, 20° 30'S, have involved studies of the biological and chemical features of Lake Tebenquiche, situated in the interior of the salar. Chemically, Tebenquiche is hypersaline, with practically anoxic waters dominated by sodium and chloride ions but with high concentrations of sulphate also. The lake is surrounded and invaded by macrophytes, dominated by Scirpus olmeyi and Juncus, which provide organic material for the formation of bacterial mats. The fauna of limnetic crustaceans is almost exclusively of Artemia salina. The most important genera of bacteria are: Marinomonas, Halobacterium, Acinetobacter and the sulphur reductors Vibrio and Bacillus. The Cyanobacteria are represented exclusively by Oscillatoria.     

Fine needle aspiration of retroperitoneal human dirofilariasis with a pseudotumoral presentation

The accidental finding of a pseudotumoral para-aortic mass in a 60-year-old woman led to the performance of a fine needle aspiration (FNA) biopsy under ultrasonographic guidance. The milky aspirate was centrifuged and processed as a cell block. The examination of sections confirmed the lymphatic origin of the sample, but also revealed some unexpected parasitic structures. While a complete identification could not be made on a few sections, the morphologic and epidemiologic evidence suggested Dirofilaria repens. The mass was surgically removed and identified as an adenolymphocele, which appears to be a new localization of dirofilariasis in humans. This case emphasizes the utility of FNA in diagnosing such unexpected findings without the use for exploratory surgery.     

Proteinases and amylases of larval midgut of Zabrotes subfasciatus reared on cowpea (Vigna unguiculata) seeds

Proteinase and amylase activities in larval midguts of the bruchid beetle Zabrotes subfasciatus (Boh.) (Coleoptera: Bruchidae) reared on cowpea (Vigna unguiculata (L.) Walp.) seeds were investigated. We could detect and isolate a proteolytic activity with a pH optimum of 5.5 (on azo-casein as substrate) which was activated by thiol reagents and inhibited by several compounds reactive against-SH groups. None of the plant protein inhibitors of serine proteinases utilized were effective inhibitors of this activity. This activity has characteristics of a cysteine class proteinase. We could also detect and isolate a proteolytic activity with a pH optimum of 3.5 (on hemoglobin as substrate) which was not influenced by activators or inhibitors of cysteine, serine, or metalloproteinases. This activity was totally inhibited by pepstatin, a specific inhibitor of aspartic proteinases. We conclude that this activity is due to an aspartic class proteinase. We found also that the aspartic class proteolytic activity is higher than the cysteine class proteinase activity in the midguts of Z. subfasciatus. This seems to be contrary to what is found in Callosobruchus maculatus (F.) larvae midguts. An amylolytic activity with the charateristics of an -amylase was also detected and isolated.

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Résumé Les activités protéinase et amylase ont été étudiées sur l'intestin moyen de larves de Zabrotes subfasciatus Boh. (Coléo, Bruchidae), élevées sur graines de Vigna unguiculata Walp. Nous avons pu déceler et isoler une activité protéolytique optimale à pH 5,5 (sur substrat d'azo-caséine) activée par des réactifs thiol et inhibée par plusieurs composés réagissant aux groupements SH. Aucun inhibiteur végétal des sérine-protéases utilisé n'a inibé efficacement cette activité qui présente les caractéristiques des protéines de la famille des cystéines. Nous avons pu déceler et isoler aussi une activité protéolytique optimale au pH 3,5 (sur hémoglobine comme substrat) qui n'était pas modifiée par les activateurs ou les inhibiteurs de cystéine, de sérine ou de métalloprotéinases. Cette activité était totalement inhibée par la pepstatine, inhibiteur spécifique des protéinases aspartiques. Nous en concluons que l'activité est due à une protéinase de la famille aspartique. Nous avons trouvé aussi que l'activité protéolytique de la famille aspartique était supérieure à l'activité protéinase de la famille cystéine dans l'intestin moyen de Z. subfasciatus. Ceci semble l'inverse de ce qui a été observé dans l'intestin moyen des larves de Callosobruchus maculatus F. (C.P. Silva & al, in litt.). Une activité amylolytique ayant les caractéristiques d'une -amylase a aussi été décelée.

     

The effect of clupeinon anisotropy and basophilia of polytene chromosomes

Summary When polytene chromosomes are subjected to a clupein treatment, their properties of basophilia and anisotropy are affected. The basophilia is deeply reduced, except in the nucleolar zones, puffs and sites of RNA accumulation. On the other hand, the chromosome birefringence increases. The phenomenon of anomalous dispersion of birefringence usually observed on polytene chromosomes stained with toluidine blue solutions turns into a normal negative dispersion of birefringence, when staining is preceded by clupein treatment. It is concluded that the clupein molecules attach orderly and preferentially to sequential DNA phosphates unbound to chromosome proteins, accentuating DNA anisotropic characteristics. The clupein molecules appear not attaching to RNA phosphates.     

Temperature Effects on Development of Meloidogyne Enterolobii and M. Floridensis

Meloidogyne enterolobii and M. floridensis are virulent species that can overcome root-knot nematode resistance in economically important crops. Our objectives were to determine the effects of temperature on the infectivity of second-stage juveniles (J2) of these two species and determine differences in duration and thermal-time requirements (degree-days [DD]) to complete their developmental cycle. Florida isolates of M. enterolobii and M. floridensis were compared to M. incognita race 3. Tomato cv. BHN 589 seedlings following inoculation were placed in growth chambers set at constant temperatures of 25°C, and 30°C, and alternating temperatures of 30°C to 25°C (day–night). Root infection by the three nematode species was higher at 30°C than at 25°C, and intermediate at 30°C to 25°C, with 33%, 15%, and 24% infection rates, respectively. There was no difference, however, in the percentages of J2 that infected roots among species at each temperature. Developmental time from infective J2 to reproductive stage for the three species was shorter at 30°C than at 25°C, and 30°C to 25°C. The shortest time and DD to egg production for the three species were 13 days after inoculation (DAI) and 285.7 DD, respectively. During the experimental timeframe of 29 d, a single generation was completed at 30°C for all three species, whereas only M. floridensis completed a generation at 30°C to 25°C. The number of days and accumulated DD for completing the life cycle (from J2 to J2) were 23 d and 506.9 DD for M. enterolobii, and 25 d and 552.3 DD for M. floridensis and M. incognita, respectively. Exposure to lower (25°C) and intermediate temperatures (30°C to 25°C) decreased root penetration and slowed the developmental cycle of M. enterolobii and M. floridensis compared with 30°C.     

Cryopreservation of immature equine oocytes, comparing a solid surface vitrification process with open pulled straws and the use of a synthetic ice blocker

The objective was to evaluate the effect of three cryopreservation methods on the in vitro maturation (IVM) and membrane integrity (MIn) of immature equine oocytes. An open pulled straw (OPS) method, a novel solid surface vitrification (SSV) process, and the addition of a synthetic ice blocker were evaluated. Compared with the control group (N = 269), the OPS (N = 159) and the SSV (N = 202) cryopreservation methods decreased both IVM (50.9 vs. 13.3 and 9.4%, respectively; P < 0.001) and MIn (76.6 vs. 31.1 and 33.7%; P < 0.001) of immature equine oocytes. However, inclusion of 0.1% ice blocker in the OPS vitrification process increased the rates of both IVM (30.5%; P < 0.01) and MIn (45.8%; P < 0.05) of the oocytes (N = 59). Including 0.1% ice blocker in the SSV process improved the IVM rate (20.9%; P < 0.05), whereas MIn remained compromised in this group (N = 67). However, increasing the concentration of the ice blocker (to 1.0%) in the cryopreservation methods did not significantly improve rates of IVM. In conclusion, the addition of a synthetic ice blocker (0.1%) to both cryopreservation processes significantly increased rates of both IVM and MIn of immature equine oocytes cryopreserved by OPS.     

Effect of end-stage renal disease and diabetes on zinc and copper status

The aim of this study was to compare the nutritional status of zinc and copper in patients with and without diabetes submitted to chronic hemodialysis. Thirty-three patients with type 2 diabetes (DM group), 30 nondiabetic patients (NDM group), and 20 healthy individuals (control group) were studied. Plasma, erythrocyte, and urinary zinc and plasma copper were obtained from atomic absorption spectrophotometry and ceruloplasmin by immunonephelometry. The anthropometric parameters were similar among the groups. Plasma zinc was lower and erythrocyte zinc was higher in the DM and NDM groups in relation to the control group. No difference in urinary zinc was observed comparing the groups. Plasma copper was higher in the DM group when compared to the NDM and control groups. Ceruloplasmin was similar in the three groups. Serum urea was a positive independent determinant of plasma zinc concentrations. The determinants of erythrocyte zinc were MAMC midarm nuscle circumference and Kt/V dialysis adequacy. The determinants of plasma copper concentration were serum creatinine and serum glucose. The results of this study demonstrate an alteration in the distribution of zinc of patients with chronic kidney disease (CKD) independently of the presence of DM. Also, the status of copper seems not to be influenced by CKD, but only by the metabolic derangements associated with diabetes.