Renal sugar transport in the winter flounder IV. Effect of CA2+ on sugar transport in teased renal tubules

The electrolyte distribution and sugar uptake by teased renal tubules of winter flounder (Pseudopleuronectes americanus) was studied using incubation media with 1.4 mM Ca²⁺ (controls) and without Ca²⁺. The omission of Ca²⁺: (a) produced some cellular swelling, and increase in cell Na⁺ and loss of K⁺; (b) had no effect on the extracellular propylene-glycol space; (c) increased the uptake of non-metabolizable methyl-α-D-glucoside by the tissue: whereas in controls the equilibrium tissue/medium ratio (T/M) for the Na⁺-independent uptake of the sugar was 0.71 ± 0.03 (SEM, n = 9), in Ca²⁺-free media the T/M rose in 1.18 ± 0.06. The increase in sugar uptake seen in absence of Ca²⁺ was abolished by absence of Na⁺ (Li⁺-media), 0.5 mM ouabain and 0.5 mM phlorizin; (d) produced an increase in the galactose phosphate level without affecting that of free sugar; (e) decreased the active uptake of 2-deoxy-D-galactose by the tubules. These results were analyzed on the basis of available information on the transport characteristics of the sugars at the luminal and antiluminal cell faces. It is suggested that absence of Ca²⁺ increases the permeability of the intercellular junctions, thus permitting sugars to enter from the external medium into the tubular lumen. Methyl-α-D-glucoside and D-galactose can then be taken up into the cells by brush-border localized active processes, whereas 2-deoxy-D-galactose is not reabsorbed at this cellular face. At 1.4 mM Ca²⁺, the intercellular junction appears to be relatively impermeable to sugars and the transport properties in teased tubules reflect then events predominantly localized at the antiluminal cell face.     

Altered gene and protein expression by Nm23-H1 in metastasis suppression

The aim of our work was to study (1) the antioxidant properties of lipoic acid (LA) and its reduced metabolite dihydrolipoic acid (DHLA) formed by reduction of LA and (2) the effects of treatment with LA and DHLA on (a) K(+) efflux from human red blood cells and (b) post-ischemic recovery and oxidative stress in isolated perfused rat hearts challenged with an ischemia-reperfusion (IR) sequence. In vitro, we used xanthine and xanthine oxidase to generate superoxide anion, which is not directly measurable by electron paramagnetic resonance (EPR), but specifically oxidizes the spin probe CPH into an EPR-detectable long lasting CP(*) nitroxide radical. While 5 mM of LA was ineffective in reducing the kinetics of CP(*) nitroxide formation, DHLA was shown to lessen this rate in a dose-dependent manner and at 30 mM was even more efficient than 300 UI/ml SOD. These results are in agreement with the fact that DHLA is able to directly scavenge superoxide anion. Red cells are a good model to investigate oxidative damage in biological membranes; hence, we used a suspension of erythrocytes incubated with 2,2(')-azobis(2-amidinopropane) hydrochloride (AAPH) which generates in vitro free radicals. DHLA provided more effective protection of red cells membranes than LA; DHLA was comparable to Trolox for its antioxidant potency. In vivo, treatment of rats (50 mg/kg/day i.p. for 7 days) with LA induced a slight increase in coronary flow (CF) in isolated perfused hearts, after 30 min of global total ischemia. This effect was not associated with an improvement in contractile function and reduction of myocardial oxidative stress. In conclusion, because of their ability to scavenge free radicals, LA and to an even greater degree DHLA were able to protect the membranes of red blood cells. This finding suggests that LA and DHLA might be useful in the treatment of diseases associated with oxidative stress such as diabetes.     

The genus Hyalomma Koch, 1844. IX. Redescription of all parasitic stages of H. (Euhyalomma) impeltatum Schulze & Schlottke, 1930 and H. (E.) somalicum Tonelli Rondelli, 1935 (Acari: Ixodidae)

The ticks Hyalomma (Euhyalomma) impeltatum Schulze &; Schlottke, 1930 and H. (E.) somalicum Tonelli Rondelli, 1935 [a species resurrected for “Hyalomma ? species” of Hoogstraal (1956) and H. erythraeum of Kaiser &; Hoogstraal (1968)] are tentatively considered to belong to the H. (E.) asiaticum group of closely related species. Amongst other features that are fairly similar, males of H. impeltatum can be distinguished from those of H. somalicum by the oval posterior margin of the conscutum, a narrow, subtriangular parma, the lack of ventral sclerotised plaques on median, paramedian and 4th festoons, and an incomplete to complete ivory-coloured stripe on the dorsal aspect of the leg segments; whereas males of H. somalicum have a broad but only slightly convex posterior conscutal margin, in most cases no parma, well-developed sclerotised ventral plaques on all festoons, and only a small ivory-coloured spot on the dorsal aspect of the leg segments. Females of H. impeltatum can be distinguished from those of H. somalicum by the bulging rather than flat preatrial fold of the genital aperture. All parasitic stages of both ticks are illustrated and redescribed, and the characteristics that distinguish the adults from those of other closely related species are detailed. Larger domestic and wild ungulates are the principal hosts of the adults of both ticks. Nymphs and larvae of H. impeltatum parasitise rodents, leporids, birds and lizards, whereas the hosts of the immature stages of H. somalicum are unknown. H. impeltatum is widely distributed in Africa north of the equator, Arabia, the Near East and south-western part of Central Asia; in contrast, H. somalicum has a more limited distribution in East Africa and possibly the Arabian Peninsular. Data on their possible disease relationships are also provided.     

Carcinoembryonic antigen antibody inhibits lung metastasis and augments chemotherapy in a human colonic carcinoma xenograft

Purpose: In addition to its use as a blood marker for many carcinomas, elevated expression of carcinoembryonic antigen (CEA, CD66e, CEACAM5) has been implicated in various biological aspects of neoplasia, especially tumor cell adhesion, metastasis, the blocking of cellular immune mechanisms, and having antiapoptosis functions. However, it is not known if treatment with anti-CEA antibodies can affect tumor metastasis or alter the effects of cytotoxic drugs. Methods: In vitro, human colon cancer cell lines were treated with anti-CEA MAb IgG₁, hMN-14 (labetuzumab), to assess direct effects on proliferation, as well as antibody-dependent cellular cytotoxicity (ADCC), and complement-dependent cytotoxicity (CDC). In vivo studies were undertaken in nude mice bearing s.c. (local growth) or i.v. (metastatic model) GW-39 and LS174T human colon cancer grafts, to evaluate the MAb alone and in combination with either CPT-11 or 5-fluorouracil (5FU). Results: In vitro, labetuzumab did not induce apoptosis, nor did it affect tumor cell proliferation directly or by CDC, but it did inhibit tumor cell proliferation by ADCC. In vivo, labetuzumab did not increase median survival in the GW-39 metastatic model unless the mice were pretreated with GM-CSF to increase their peripheral WBC counts; GM-CSF alone was ineffective. Also, if GW-39 tumors were pretreated with IFN- to up-regulate CEA expression threefold prior to i.v. injection, labetuzumab significantly increased median survival of the mice. When nude mice received labetuzumab with CPT-11 or 5FU, median survival increased significantly as compared to the drug or antibody alone. Conclusions: Labetuzumab, a CEA-specific MAb, induces effector-cell function in vitro against CEA-positive colonic tumor cells, and also inhibits growth of lung metastasis when CEA expression is up-regulated or if peripheral WBCs are increased. The MAb also shows chemosensitizing properties.     

Arthromyces and Blastosporella, two new genera of conidia-producing lyophylloid agarics (Agaricales, Basidiomycota) from the neotropics

Two new genera encompassing three new species of lyophylloid agarics that produce conidia on the basidiomata are described. Arthromyces is a genus comprised of two very different arthrospore-producing mushroom species found in the Greater Antilles and Central America. Blastosporella is a monotypic genus with spherical balls of blastospores covering the pileus surface with age and is known from Hispaniola and Colombia. A key to the species of Arthromyces is included.     

Phylogeny of Rozites, Cuphocybe and Rapacea inferred from ITS and LSU rDNA sequences

Phylogenetic relationships of Rozites, Cuphocybe, and Rapacea were assessed using molecular phylogenetic approaches. These three genera are placed in Cortinariaceae and have been regarded as closely related to Cortinarius. Rozites includes more than 20 species, which are characterized by having both a membranaceous partial veil in the form of a persistent annulus and a membranaceous universal veil. Cuphocye (4 species) lacks an annulus or cortina, but has pigmented veil fibrils or scales. The monotypic genus Rapacea accommodates a distinct taxon with pale, nearly smooth and thick-walled basidiospores. We analyzed 56 sequences of the internal transcribed spacer region (ITS1, ITS2, and the intervening 5.8S rRNA gene) for nine species of Rozites, three species of Cuphocybe, 28 species of Cortinarius, Rapacea mariae and Protoglossum luteum. Two species of Hebeloma were used as outgroup. Large subunit (LSU) rDNA sequences from selected taxa were also analyzed. The results clearly demonstrate that Rozites species are nested within the clade/Cortinarius, and that Rozites is polyphyletic, suggesting that membranaceous veils have evolved several times in the genus Cortinarius. Also Rapacea and Cuphocybe are nested within Cortinarius, making the latter genus paraphyletic. Based on phylogenetic studies, Rozites, Cuphocybe and Rapacea are artificial genera and do not reflect natural relationships.     

The life cycle of Ixodes rubicundus (Acari: Ixodidae) and its adaptation to a hot,dry environment

The life cycle of Ixodes rubicundus, the Karoo paralysis tick, was studied under field conditions in the south-western Orange Free State, South Africa, by placing freshly engorged ticks in small containers. The life cycle extends over 2 years. The two regulating phases in the life cycle, which undergo a morphogenetic diapause during the hot and dry summer months, are the egg and engorged nymph. Possible behavioural diapause in adults which suppresses questing activity before the end of March. can also serve as a third regulating phase. Temperature affects the duration of the pre-oviposition period of engorged females and the period between detachment of engorged larvae from hosts and ecdysis. Commencement of larval hatch is reasonably synchronized, irrespective of the month during which oviposition occurred. Peak activity periods of larvae (April or May) occur during a period of high rainfall and decreasing daily maximum temperatures. The period between detachment of engorged nymphs from hosts and ecdysis is highly variable (8–36 weeks). All developmental stages of the tick occur mainly during autumn and winter and no ticks are active during the hot summer months of December to February. Larvae, nymphs and adults each survive for only one season.     

Effect of anisotonic media on cell volume and electrolyte fluxes in slices of the dogfish (Squalus acanthias) rectal gland

Summary Osmotic responses of slices of dogfish rectal gland to hypotonic (urea-free) and hypertonic media were studied. Transfer of tissue from isotonic (890 mosM) to hypotonic (550 mosM) saline produced an osmotic swelling associated with a slow net uptake of cell K⁺ (and Cl^–) and a slow, two-component efflux of urea. Media made hypertonic (1180 mosM) by addition of urea or mannitol produced osmotic shrinkage with a net loss of KCl. The cell osmotic responses in hypotonic media were lower than predicted for an ideal osmometer. No volume regulatory responses were seen subsequent to the initial osmotic effects. The cation influx in hypotonic media lacked specificity: in the presence of 0.5 mM ouabain or in K⁺-free media a net influx of Na⁺ was found. At steady state, the cell membrane potential evaluated from the Nernst potentials of K⁺ and triphenylmethyl phosphonium⁺, was independent of medium tonicity, suggesting the membrane potential as a determinant in the cellular osmotic response. Zero-time⁸⁶Rb⁺ fluxes were measured:⁸⁶Rb⁺ influx was not affected by hypotonicity, implying an unchanged operation of the Na⁺–K⁺-ATPase. On the other hand,⁸⁶Rb⁺ efflux was significantly reduced at hypotonicity; this effect was transient, the efflux returning to the control value once the new steady state of cell volume had been reached. A controlled efflux system is therefore involved in the cell osmotic response. The absence of the volume regulatory phenomenon suggests that the cells are not equipped with a volume-sensing mechanism.Abbreviations and symbols DW dry weight - E extracellular (polyethylene glycol) space - E Nernst potential - H₂O_e H₂O_i tissue water, extra- and intracellular - TPMP ⁺ triphenyl methyl phosphonium salt - WW wet weight     

Factors significant in the diagnostic accuracy of lung cytology in bronchial washing and sputum samples. I. Bronchial washings

Some factors influencing the diagnostic accuracy for primary lung cancer in bronchial washings were studied in 276 consecutive cases seen between 1959 and 1974. Diagnostic accuracy increased during the years under study; the reasons included increasing expertise of the laboratory staff, better documentation of cytologic criteria and improved collection techniques. The overall accuracy was 74%. Detection of malignant cells was highest for squamous-cell and adenosquamous carcinomas (81%), small-cell carcinoma, adenocarcinoma and large-cell carcinoma (70%) and lowest for bronchioloalveolar-cell carcinoma (47%). Accuracy was 84% for central tumors as compared to 30% for peripheral lesions. Tumors of less than 2 cm in diameter yielded very poor results (15%) while those greater than 2 cm yielded 82% accuracy. The specificity of diagnosis of cell type in those specimens with malignant cells was over 93% for squamous-cell carcinoma, small-cell carcinoma and adenocarcinoma, 77% for large-cell carcinoma and below 50% for adenosquamous carcinoma, bronchioloalveolar carcinoma and the uncommon tumors. Two bronchial washings per case gave an appreciably better result (92%) than one per case (68%). The percentage of unsatisfactory specimens from those with cancer was 13.5 and from a control group was 29.9. Reasons for unsatisfactory specimens included limited cellular material, excessive blood and/or leukocytes and drying artifacts.     

Ribosomal proteins of HeLa cells

Ribosomal proteins from HeLa cells were analyzed by two-dimensional polyacrylamide gel electrophoresis (Kaltschmidt-Wittmann) and dodecylsulfate polyacrylamide gel electrophoresis (Laemmli). 35 proteins are associated with the small ribosomal subunit and 47 proteins with the large ribosomal subunit. The HeLa ribosomal proteins S6, S32, L40b,c, L41 and L42 are phosphorylated in vivo and in vitro. Minor differences between HeLa and rat liver ribosomal proteins were revealed by their direct coelectrophoresis.