Volume regulation by flounder red blood cells in anisotonic media

The nucleated high K, low Na red blood cells of the winter flounder demonstrated a volume regulatory response subsequent to osmotic swelling or shrinkage. During volume regulation the net water flow was secondary to net inorganic cation flux. Volume regulation the net water flow was secondary to net inorganic cation flux. Volume regulation after osmotic swelling is referred to as regulatory volume decrease (RVD) and was characterized by net K and water loss. Since the electrochemical gradient for K is directed out of the cell there is no need to invoke active processes to explain RVD. When osmotically shrunken, the flounder erythrocyte demonstrated a regulatory volume increase (RVI) back toward control cell volume. The water movements characteristic of RVI were a consequence of net cellular NaCl and KCl uptake with Na accounting for 75 percent of the increase in intracellular cation content. Since the Na electrochemical gradient is directed into the cell, net Na uptake was the result of Na flux via dissipative pathways. The addition of 10(-4)M ouabain to suspensions of flounder erythrocytes was without effect upon net water movements during volume regulation. The presence of ouabain did however lead to a decreased ration of intracellular K:Na. Analysis of net Na and K fluxes in the presence and absence of ouabain led to the conclusion that Na and K fluxes via both conservative and dissipative pathways are increased in response to osmotic swelling or shrinkage. In addition, the Na and K flux rate through both pump and leak pathways decreased in a parallel fashion as cell volume was regulated. Taken as a whole, the Na and K movements through the flounder erythrocyte membrane demonstrated a functional dependence during volume regulation.     

2-β-d-Glucopyranosyloxy-2-methylpropanol in Acacia sieberana var. woodii

A new diol glucoside, 2-β-d-glucopyranosyloxy-2-methylpropanol, the first reported naturally occurring monoglucoside of an aliphatic dihydric alcohol, was isolated from pods of Acacia sieberana var. woodii. Structure elucidation was based on ¹ H and ¹³C NMR spectroscopy, and enzymatic analyses. The compound was hydrolysed very slowly by almond β-glucosidase, but cleaved by a β-glucuronidase enzyme complex from Helix pomatia.     

Schistosoma mansoni and Fasciola hepatica: Cross-resistance in mice with single-sex schistosome infections

Primary Schistosoma mansoni single-sex infections in mice, i.e., either male only or female only, did not stimulate any detectable level of heterologous resistance to challenge with Fasciola hepatica after 22 to 76 days, while statistically significant resistance to a challenge with F. hepatica was demonstrated in the presence of patent mixed-sex S. mansoni infections. Simultaneous infections with S. mansoni and F. hepatica induced a statistically significant reduction in the number of schisto-some worms established, i.e., the burden being reduced by 40.1 and 43.9%, respectively. There was no reduction of the F. hepatica worm burden. Similar features could be observed with a time interval of 48 hr between the S. mansoni infection and the F. hepatica challenge, i.e., the schistosome burden being reduced by 34.2 and 45.6%, respectively. Furthermore, simultaneous infections with S. mansoni and F. hepatica induced a statistically significant reduction of the egg production capacity per paired female schistosome worm as compared with that of the S. mansoni control group. Tissue egg counts of the various intestinal sections were reduced by 92.8–99.6%.     

Interaction between prostaglandins of the E-type with a urinary component from halothane anaesthetized rats

Prostaglandins of the E-type (PGE's) were found to react or combine with a urinary metabolite of Halothane yielding products which left unrecovered during the purification procedure preceeding specific radioimmunoassay of PGE₂. The products were retained on sephadex LH-20 columns, and showed on thin layer silica gel plates (TLC) R_f values lower than those of the parent PGE-compounds. The product formation is supposed to involve the β-hydroxyketone system of PGE, since PG's of the F and A type were unaffected. The product formation could be avoided by inducing anaesthesia with Hexobarbitone and maintaining the anaesthesia with Halothane-nitrous oxide or it could be reveresed by adding barbiturates to urine samples obtained from animals anaesthetized with Halothane- nitroux oxide alone. The barbiturates effectively competed with PGE for the metabolite leaving PGE to behave normally on sephadex LH-20 and TLC, thus enabling us to evaluate correctly the PGE₂ content by RIA.     

Purification and reaction mechanism of the primary inhibitor of plasmin from human plasma

The primary inhibitor of plasmin in human plasma was purified by a four-step procedure involving fractional (NH(4))(2)SO(4) precipitation, ion-exchange chromatography on a column of DEAE-Sepharose CL-6B and affinity chromatography on both a plasminogen-CH-Sepharose 4B column and a column of 6-aminohexanoic acid covalently coupled through the carboxylate function to AH-Sepharose 4B. No impurities in the final preparation could be detected when tested by immunoelectrophoresis against a range of specific antisera or against rabbit anti-human serum. On polyacrylamide-gel electrophoresis the inhibitor preparation showed a single band. The dissociation constant for the inhibitor-plasminogen complex was determined to be approx. 3mum at pH7.8. The reactions of the inhibitor with human plasmin and with bovine trypsin were studied. Comparison of the results obtained confirms the hypothesis previously presented, namely that the reaction of the inhibitor with plasmin involves at least two steps, the initial rapid formation of an enzyme-inhibitor complex followed by a slow irreversible transition to another complex. The results also indicate that the reaction of the inhibitor with trypsin involves just a single, irreversible step, so that this reaction seems to be less complicated than that of the inhibitor with plasmin. The ways in which 6-aminohexanoic acid influences the reactions were studied. The same value for the dissociation constant (approx. 26mum) for 6-aminohexanoic acid is obtained for both its effect on the reaction of the inhibitor with trypsin and for competitive inhibition of trypsin. The inhibitory effect of 6-aminohexanoic acid thus seems to be due to its blocking of the active site of trypsin. In contrast with this, the inhibitory effects of l-lysine and 6-aminohexanoic acid on the inhibitor-plasmin reaction occur at concentrations much too low to affect the active site of plasmin. The possible dependence of the reaction of the inhibitor with plasmin on a second site(s) on plasmin is discussed.     

Hyperparathyroidism in pregnancy: case report and review of the literature.

The apparent incidence of hyperparathyroidism (HPT) is low in pregnancy but will likely increase now that more asymptomatic HPT is being diagnosed. However, since the serum calcium levels are decreased in pregnant women, mild primary HPT may go unrecognized. In untreated cases of HPT, complications during pregnancy or during the neonatal period have included spontaneous abortion, stillbirth, neonatal death, neonatal tetany and hypercalcemia. A review of the literature indicates a substantial improvement in fetal outcome when parathyroidectomy is done during pregnancy, as in the case reported here. Therefore, parathyroidectomy is the treatment of choice when the diagnosis is made during pregnancy, although oral phosphate therapy may be an alternative if surgery is contraindicated.     

A biometric study of some hybridizing Crataegus populations in Denmark

Crataegus curvisepala Lindm., C. laevigata (Poiret) DC. and C. monogyna Jacq. (Rosaceae) form hybrid complexes in Denmark due to introgression. C. palmstruchii Lindm. seems to be variously introgressed individuals of C. laevigata. C. eremitagensis Raunk., C. raavadensis Raunk. and C. schumacheri Raunk. apparently belong to C. curvisepala x laevigata. The delimitation between C. curvisepala x laevigata and C. laevigata x monogyna is discussed.