Observations on Eimeria tenella in Feces of Inoculated Chickens

SYNOPSIS. In studies on coccidial excystation, Eimeria tenella sporulated oocysts were fed to 5 individually caged chickens, and during the next 4.5 hours, all droppings were collected immediately after excretion, mixed with 0.85% NaCl solution, then promptly examined for the parasites. Some samples were placed in cold storage at 4 C and examined at intervals thereafter. Three of the birds were necropsied after 5 hours and the intestinal contents examined. Apparently unbroken oocysts containing active sporozoites were in chicken droppings beginning 1–2.25 hours postinoculation; some activated forms were inside and others outside the sporocysts. Free sporozoites, sometimes numerous, first appeared in the feces 1.1–2 hours postinoculation. At necropsy, the state and condition of the parasites in the lumen of bird intestines were similar to those in its last fecal dropping. After being in cold storage for 48 hours, free sporozoites inside and outside the oocysts became active and moved about when placed on the warming stage of the microscope.     

Biochemical Comparison of Some Classical Tetrahymena pyriformis and T. vorax Strains*

SYNOPSIS. The classical Tetrahymena pyriformis and T. vorax strains have been classified in antigenic subgroups based on immobilization and agar double diffusion in the presence of specific antisera. The present study utilized disc electrophoresis of proteins and lactate dehydrogenase isozymes for comparison of 11 strains. In agreement with similarities reported for agar diffusion data, close electrophoretic relationships were observed between strains GL and H, and V₂ and W with aniline black staining. Altho LDH isozyme production was more variable and related to cultural growth phase, similarities were recognized between GL and H, and F and PR.     

Some early works on heliconiine butterflies and their biology (Lepidoptera, Nymphalidae)

In the course of a survey of the history of the study of Heliconiinae, particularly their biology, in the eighteenth and nineteenth centuries it is shown that Heliconius nigromarginatus (Goeze) and H. pallescens (Goeze) are nomina oblita , and that H. cinereofuscus (Goeze) is not, as always supposed, a species in its own right. A new name is proposed for H. melpomene cybele (Cramer). The origin and application of some of Linnaeus' names is discussed.
Illustrations of Heliconius by Seba, Clerck, Petiver and Cramer show that three species, melpomene, erato and doris have been polymorphic at least since the middle of the eighteenth century.
The Indo-Australian genus Cethosia should probably be included in the Heliconiinae.     

Range of Variation in the Somatic Infraciliature and Contractile Vacuole Pores of Tetrahymena pyriformis

SYNOPSIS. Meridian ranges and contractile vacuole pore patterns were determined for 36 strains of Tetrahymena pyriformis, including most of the “classic” amicronucleate and micronucleate strains used by many investigators, plus a dozen other strains not previously characterized with respect to these two morphological features. Uniform axenic culturing and staining techniques were employed. Meridian ranges and modes are analyzed with strain-by-strain comparisons to the reports of previous investigators. The overall inclusive range of the 36 strains was 15–25 meridians. Modes for individual strains varied from 16 to 23. Broader ranges and, especially, higher modes and higher limits are recorded than those reported by Corliss (1953) for strains grown in bacterized hay cultures. Two postoral meridians are characteristic, although a single individual having only one and a few having three postorals were observed. Three postorals were found only in those strains having the higher number of total meridians. A few individuals, showing an anterior half or a posterior half of a bipolar meridian missing, indicate a possible explanation of how a single dividing individual could produce a proter and an opisthe differing in the total number of meridians. Meridian ranges of individual strains do not overlap each other in all cases, but they do constitute a progressively overlapping series which does not warrant taxonomic separation of strains at either extreme from each other. Contractile vacuole pores varied from 1 to 3, with 2 pores (1 each in meridians 5 and 6) being characteristic of 22 of the strains. The 2-pore 6-7 pattern was modal for 8 of the strains. Presence of 3 pores (in 5, 6 and 7) was typical of only 2 strains, but 3 pores were found occasionally. Another pattern of 3 pores (in 6, 7 and 8) was observed occasionally in 10 strains. Double pores (in 6 and 7 or 7 and 8) and the triple pore patterns were observed only in the strains having the highest total number of meridians. These variations are not considered adequate justification for taxonomic separation. Strains Ki and Aq are affirmed to be T. pyriformis. Strains V¹ PP and V, formerly regarded as strains of T. vorax, are considered to be T. pyriformis, supporting the view of Shaw and Williams (1963).     

Eimeria scholtysecki n. sp. from Ord's Kangaroo Rat Dipodomys ordii*

SYNOPSIS. Eimeria scholtysecki n. sp. is described from Ord's kangaroo rat Dipodomys ordii. The sporulated oocysts are broadly ovoid to ellipsoid, averaging 24.6 by 19.6 μ. A polar granule is present. A micropyle and oocyst residuum are absent. The ovoid sporocysts average 12.1 by 8.0 μ, and have small, flattened Stieda bodies. The distinctive sporocyst residuum is composed of coarse granules. The mean prepatent period was 8.2 days. Five inoculated rats apparently became reinfected and discharged oocysts for 30 days or more.     

Ultrastructural Observations on the Development of the Microsporidian Protozoon Plistophora hyphessobryconis Schaperclaus*

SYNOPSIS. A sequence of developmental stages of Plistophora hyphessobryconis Schaperclaus, a microsporidian protozoan parasite of the muscular tissue of several species of freshwater fishes, was studied with the electron microscope. The youngest stages observed, ca. 4 × 2 μ, have a single nucleus and their plasm contains only ergastoplasmic lamellae and ribosomes. They are surrounded by a halo of lysed host tissue. They increase in volume to become large sporonts with a great number of nuclei and a thick, 2-layered membrane. Thru schizogony, a corresponding number of sporoblasts is produced within this pansporoblast membrane. Sporoblasts start to develop a thick spore membrane, and a number of smooth-membraned vesicles appear in the plasm. These vesicles fuse to make the outer membrane of the filament. Later, its inner structures originate—the axial electron-dense substance, filling the hollow lumen of the filament, and a middle, electron-transparent layer. The structure of the filament is discussed in relation to its function and with regard to the findings of other authors. The polaroplast is a laminated structure, originating possibly by transformation of endoplasmic reticulum; the polar cap forms its apical part. The cap is also lamellar; its substance reaches into the lumen of the filament for a certain distance. No micropyle was discovered in the shell; the filament is fastened to the polar cap. These observations on microsporidian development and on the structure of their spores are compared with similar data on myxosporidian species. Such a comparison speaks clearly in favor of the complete taxonomic separation of the Microsporidea from the Myxosporidea, the latter being quite different also from other sporozoa sensu lato.     

Excitation-Contraction Coupling in Crayfish

High-sensitivity recording techniques demonstrate a continuousrelation between the onset and magnitude ot tension and themembrane depolarization that is induced by increasing K in thebathing medium or by intracellularly applied outward currents.This finding is not consistent with the mechanism of signallinge-c coupling by electrotonic spread of a "critical" depolarizationinward along the membrane of the transverse tubular system.It is in accord, however, with the channelled current mechanismthat is based on the known anion-permselectivity of the membranein the terminals of the TTS. The channelled-current model alsopredicts a direct role of Cl and a possible interaction betweenCa and CI in e-c coupling. The initiation and maintenance oftension as well as its magnitude, are in fact dependent uponthe concentrations of Ca and Cl in the medium. Thus, both thesignalling to, and the activation of, the contractile systemappear to be performed by a flow of current in the loop: cellmembrane – cell interior – TTS membrane –TTS channels – exterior, as is envisaged in the channelled-currentmodel of e-c coupling.     

Ultrastructural Observations on Life Cycle Stages of Pneumocystis carinii

An ultrastructural study of life cycle stages of Pneumocystis carinii in infected rat lungs in situ was undertaken utilizing 8 different modes of fixation. Three of the fixatives employed gave good fixation of cysts and intracystic bodies, but for the trophic forms fixation was only fair. Both the trophic forms and intracystic bodies have nuclear pores. The mitochondria of the organism have cristac that appear lamellar. One of the fixation modes revealed a thin, electron-dense layer on the outer surface of the cell wall, a "fuzzy coat" that had not been described previously. This material appears to mediate tight adhesion of trophic forms with other trophic forms, cysts, and with pneumocytcs of the lung alveolus.     

Action of Sorghum Proteinase on the Protein Bodies of Sorghum Starchy Endosperm

Protein bodies isolated from the starchy endosperm of ungerminatedsorghum exhibited some autolytic activity but seemed incapableof significant self-hydrolysis. Enzyme assay, transmission electronmicroscopy, sodium dodecyl sulphate—polyacrylamide gelelectrophoresis and amino acid analysis revealed that a proteinaseextract from germinated sorghum could degrade the protein bodiesin a manner resembling that which takes place in vivo. The proteinbodies were degraded mainly from the periphery. Glutelin (matrixprotein) was first hydrolysed, followed by the prolamin proteinbody protein. Proteinase extracts from both the germ and endospermof germinated sorghum were capable of degrading the proteinbodies. This finding is consistent with the concept that theproteinase is synthesized in the germ and then secreted intothe starchy endosperm during germination. Key words: Sorghum bicolor, protein body degradation, proteinase.     

Antimalarial Properties of Imipramine and Amitriptyline12

Dietary riboflavin deficiency is known to diminish malarial parasitemia. In this study, we determined whether imipramine and amitriptyline, drugs which inhibit riboflavin metabolism, have antimalarial efficacy. In addition, we evaluated whether these drugs, like other antimalarial agents, increase the hemolytic response to ferriprotoporphyrin IX (FP). The growth of Plasmodium falciparum (FCR3) in the absence and presence of these drugs (10 to 75 μM) was measured by determining (³H)hypoxanthine uptake by intraerythrocytic parasites for 48 h in RPMI 1640 medium. The uptake of (³H)hypoxanthine was significantly reduced in a dose-dependent manner by both imipramine and amitriptyline. The IC₅₀ values of imipramine and amitriptyline at 48 h were 56 and 45 μM, respectively. Both drugs enhanced hemolysis induced by FP (10 or 20 μM). No hemolysis by these drugs was detected in the absence of FP. It is concluded that the tricyclic antidepressants, imipramine and amitriptyline, possess substantial antimalarial properties.