bluuebunny/crossref_metadata_2025 huggingface dataset:
Cure of Incessant Pacemaker Circus Movement Tachycardia by Radiofrequency Catheter Ablation
Authors: TIMMERMANS CARL , RODRIGUEZ LUZ‐MARIA , DEN NDULK KAREL , DIJKMAN BARBARA , SMEETS JOEP L.R.M. , WELLENS HEIN J.J.
Published: May 2007

Ablation of Pacemaker Circus Movement Tachycardia. Introduction: Treatment of pacemaker circus movement tachycardia (PCMT) in patients with very long VA conduction times may present a problem.

Methods and Results: PCMT occurred in a 46‐year‐old woman with an uncommon AV nodal reentrant tachycardia who developed 2:1 AV block after fast pathway radiofrequency catheter (RF) ablation performed at another institution. Due to the long VA conduction time, PCMT could not be prevented by reprogramming the pacemaker or by the addition of antiarrhythmic drugs. Cure of the PCMT was obtained after selective RF ablation of the slow AV nodal pathway.

Conclusion: RF ablation of the retrograde conduction offers another alternative for treatment of PCMT.
Regional Entrainment of Atrial Fibrillation in Man
Authors: KALMAN JONATHAN M. , OLGIN JEFFREY E. , KARCH MARTIN R. , LESH MICHAEL D.
Published: May 2007

Entrainment of Atrial Fibrillation. Introduction: The feasibility of entrainment of macroreentrant atrial arrhythmias such as atrial flutter is well documented. Recently, it has been shown that regional entrainment of atrial fibrillation is feasible in dogs.

Methods and Results: Three patients with chronic atrial fibrillation underwent electrophysiologic evaluation with attempted entrainment of atrial fibrillation prior to successful endocardial atrial defibrillation. A 16‐pole catheter was positioned in the trabeculated right atrium, and in two patients a multipolar catheter was positioned along the septum. In addition, two large surface area defibrillation catheters were placed, one in the lateral right atrium and one in the coronary sinus. Regional entrainment was attempted in the right atrium and from the catheter in the coronary sinus. Entrainment was achieved in the right atrium in all three patients over a cycle length range of 28, 17, and 13 msec, respectively, and over a radius of atrial tissue of at least 2.8 cm. Regional entrainment was demonstrated from the coronary sinus in one patient during simultaneous right atrial entrainment. Termination of atrial fibrillation during entrainment was not observed.

Conclusion: Regional entrainment of chronic atrial fibrillation is feasible in humans.
Candida dubliniensis in Recurrent Polymicrobial Tricuspid Endocarditis
Authors: Tran Christel , Cometta Alain , Letovanec Igor , Jaton Katia , Wenger Aline , Ruchat Patrick , Jaussi Andres
Published: May 2007

This report describes a successful operative case of tricuspid infective endocarditis in an IV drug user. Despite cessation of IV drug use, there were further recurrences. Six different microorganisms with multiple portals of entry were identified, including one episode of fungal endocarditis, To our knowledge, this is the first case of recurrent infective endocarditis involving Candida dubliniensis in an HIV‐negative patient.
Effect of Heart Rate on Tissue Doppler Measures of Diastolic Function
Authors: Burns Andrew T. , Connelly Kim A. , La Gerche Andre , Mooney Donald J. , Chan Justin , MacIsaac Andrew I. , Prior David L.
Published: May 2007

Background: Our aim was to study the independent effect of heart rate (HR) on parameters of diastolic function, particularly mitral annular velocities measured by tissue Doppler imaging (TDI), an effect which is not well understood. Methods: Sixteen patients with dual chamber pacemakers attending for routine pacemaker review underwent detailed echocardiographic assessment during atrial pacing with intact atrioventricular conduction at baseline and accelerated HRs. Mitral inflow and annular tissue Doppler velocities and systolic strain parameters were compared. Results: Parameters of systolic function were unaffected by increased HR. When these parameters were compared at baseline (mean 67 bpm) and accelerated HR (mean 80 bpm), the following was observed: a significant decrease in early mitral inflow (E) wave (70.5 ± 5.5 cm/s vs 63.5 ± 4.9 cm/s, P < 0.02) and early mitral annular (E′) velocities (7.0 ± 0.5 cm/s vs 6.3 ± 0.6 cm/s, P < 0.003) and a significant increase in mitral inflow A wave (70.3 ± 4.5 cm/s vs 77.3 ± 4.4 cm/s, P < 0.05) and late mitral annular (A′) velocities (9.3 ± 0.6 cm/s vs 10.8 ± 0.5, P < 0.00004). Conclusion: Changes in HR have previously unrecognized significant effects on tissue Doppler parameters of diastolic function. Further study is required to determine if tissue Doppler derived annular velocities should be corrected for HR.
Effect of External Constraint on the Index of Myocardial Performance in a Canine Model of Left Ventricular Dysfunction
Authors: Mansouri Vafa , Lavine Steven J.
Published: May 2007

Background: With left ventricular (LV) dysfunction, it is not clear how alterations in external constraint influence the index of myocardial performance (IMP). We have previously demonstrated that pericardial constraint is a factor in the production of the restrictive filling pattern. We hypothesized that altering pericardial constraint by changing intracardiac volume or removing the pericardium would produce similar directional changes in LV ejection time (LVET) and isovolumic relaxation time (IRT) resulting in minimal IMP changes. Methods: We studied 13 canines with chronic moderate LV dysfunction. LV pressures, transmitral and transaortic Doppler were obtained prior to and following pericardiectomy (PECT) with alterations of intracardiac volume, using inferior vena caval occlusion (IVCO) and volume loading. Results: With an intact pericardium, IVCO reduced LV size, LV end diastolic pressure (LVEDP), and increased deceleration time (all P < 0.05) but did not affect IMP. Volume loading increased LV size, LVEDP, and shortened deceleration time (all P < 0.05). LVET and IRT lengthened (P < 0.05), and IMP declined (0.58 ± 0.24 to 0.52 ± 0.13, P < 0.05). Following PECT, IVCO reduced LV volumes and LVEDP (P < 0.05), but did not change IMP. Volume loading increased LV size, stroke volume, and LVEDP (all P < 0.05). IMP declined (0.57 ± 0.13 vs 0.51 ± 0.14, P < 0.05) due to an increase in both LVET and IRT (P < 0.05). Comparison of stages prior to and following PECT revealed an increased LVET and stroke volume (P < 0.05) but a similar IMP. Conclusion: Increases in intracardiac volume associated with elevated LVEDP resulted in reduced IMPs. Pericardiectomy increases LV volumes, stroke volume, and LVET but did not influence IMP.
The Common Occurrence of Micronuclear Variation During Binary Fission in an Unusual Race of Paramecium caudatum
Authors: WICHTERMAN RALPH
Published: May 2007

Unstable micronuclear behavior was investigated in an unusual race of Paramecium caudatum. Lines were begun, after isolating single vegetative specimens, to yield mass cultures. After study of living specimens in the precision micro‐compression chamber and permanent preparations stained with Feulgen and iron‐hematoxylin, most paramecia revealed a single micronucleus but many were observed with two micronuclei and fewer with more than two micronuclei—occasionally three, rarely four. Specimens measured 225 microns in length; the micronucleus about seven microns. Instead of normal cyclosis, the protoplasm exhibited great fluidity. Generally two contractile vacuoles were present but specimens with three vacuoles, even four, were not uncommon.

The method of producing amicronucleate specimens and those with variable numbers of micronuclei was discovered by studying large numbers of actively dividing paramecia. Instead of a micronucleus passing to each daughter at the end of fission as in normal animals, the entire late telophase stage of the dividing micronucleus is passed to the anterior or posterior daughter cell at the time of constriction of the cell. The result is that one daughter is bimicronucleate and the other daughter amicronucleate. Bimicronucleate and amicronucleate animals are capable of dividing normally. In bimicronucleate specimens, division stages show two micronuclei in late telophase stages that result in four micronuclei, two passing to each daughter cell. However, aberrations may again occur in fission to produce variations in number of micronuclei. The irregularly shaped, atypical, macronucleus may extrude chromatin or may undergo complete fragmentation (hemixis, type D). Paramecia and macronuclei may be parasitized by a microorganism which may cause this derangement of normal micronuclear events. This possibility of induction of micronuclear variation in Paramecium by foreign microorganisms may be of considerable evolutionary significance in the genus.
Protozoa from Penikese Island
Authors: ZINN DONALD J.
Published: May 2007

Forty species of fresh and brackish water protozoa collected on August 3, 1947, on Penikese Island in Buzzards Bay, Massachusetts are identified and listed. A short historical account of the expedition on which the collection was made is given together with a brief description of the ecology of the Island. The bibliography is a nearly complete record of all published papers of the fauna and flora of Penikese Island.
The Effect of Glycerol and Related Compounds on Survival of Tritrichomonas foetus at Freezing Temperatures*
Authors: LEVINE NORMAN D. , MARQUARDT WILLIAM C.
Published: May 2007

SUMMARY. The addition of 1.0–1.1 M (9–10%) glycerol to CPLM medium of Johnson and Trussell permits Tritrichomonas foetus to survive when frozen slowly to ‐20d̀ or ‐76d̀C. and stored at either temperature. After freezing to ‐76d̀C. at the rate of 1d̀C. per minute, 38% of the protozoa were alive after 1 day, and some survived more than 128 days. After freezing to ‐20d̀C. in 1–2 hours, 63% of the protozoa were alive after 1 day, 46% after 8 days, and some survived 32 to more than 128 days in different experiments. After freezing to ‐20d̀C. in about 7 hours, 68% were alive after 1 day, 36% after 8 days, and some survived 16 to more than 64 days in different experiments. A concentration of 0.55 M (5%) glycerol is about as effective as 1.1 M, but 0.14 and 0.28 M are much less effective. If the protozoa are snap‐frozen to ‐76d̀C., glycerol does not protect them, nor do they survive slow freezing without glycerol. In CPLM medium containing 1.0 M ethylene glycol, 72% of the protozoa were alive 1 day after having been frozen to ‐20d̀C. in about 7 hours, 29% were alive after 8 days, and some survived from 16 to more than 32 days in different experiments. The above figures are averages. In parallel tests at a concentration of 1.0 M in CPLM medium following slow freezing to ‐20d̀C. and storage at that temperature for 1 day, ethylene glycol was 80–90% as effective as glycerol; 1,2,3,4‐butanetetrol was 67% as effective; 1,2‐propanediol was 57% as effective; 2,3‐butanediol, 14%; mannose, 6%; and mannitol, 1%. Glycerol monoacetate and polyvinyl alcohol were inactive; and 2,3‐dimercaptopropanol was toxic.
Effects of Temperature and Tension on Oxygen Toxicity for the Protozoa of Cryptocercus
Authors: CLEVELAND L. R. , BURKE ARTHUR W.
Published: May 2007

SUMMARY. At any given temperature level, the rate of oxygen poisoning increases proportionally with an increase in oxygen tension. But the toxicity of oxygen does not bear a proportional relationship to temperature. At a constant low tension, it is more toxic at low temperatures than at high ones and, at a constant high tension, it is less toxic at low temperatures than at high ones.
Meiosis and Nuclear Behavior in Tetrahymena pyriformis*
Authors: RAY CHARLES
Published: May 2007

SUMMARY. Chromosome behavior of strains WH‐6, and WH‐14 mating types I and II respectively of variety 1, of T. pyriformis was studied during conjugation. Meiosis takes place during the first two prezygotic divisions. The chromosomes are at late pachytene‐early diplotene during the maximum elongation of the crescent in prophase of the first micronuclear division. As the crescent shortens, five bivalent chromosomes are readily recognized. Five dyads go to each pole at the end of the first division. Following a brief interphase the second meiotic division results in four micronuclear products, each with five chromosomes. Three of these products disintegrate; the fourth undergoes mitosis resulting in two pronuclei each with five chromosomes. Following a reciprocal interchange of the migratory pronuclei between the two conjugants, the synkaryon of each is formed just anterior to the macronucleus. The diploid number of ten chromosomes has been counted at the first division of the synkaryon.
A Sugar‐Containing Basal Medium for Vitamin B12‐Assay with Euglena; Application to Body Fluids*
Authors: HUTNER S. H. , BACH MICHAEL K. , ROSS G. T. M.
Published: May 2007

SUMMARY. An improved assay of vitamin B12 is described. The z strain of Euglena gracilis, which grows more vigorously than the bacillaris strain previously used, is recommended. The pattern of B12 specificity of the two strains appears to be the same. A new medium containing sucrose, aspartic acid, glutamic acid, and glycine at pH 3.6 is well buffered and allows luxuriant growth. Vigorous utilization of sugar appears to depend on readily available nitrogen and a Krebs‐cycle component; these requirements are well met by aspartic acid (or asparagine) and glutamic acid. The proposed procedure is especially suitable for the measurement of B12 in blood serum because rise in pH and precipitation of serum proteins during incubation are minimized. Like bacillaris, the z strain allows the distinction between “combined” and “uncombined” B12 in serum. Serum may be an appropriate test material to tell whether such phagotrophs as Peranema can better utilize bound forms of vitamins than can the related osmotrophs. Patterns of B12 requirements and occurrence are discussed as phylogenetic markers.
Structure et Origine du Pedoncule chez Chilodochona.
Authors: FAURÉ‐FREMIET E. , Ch. ROUILLER  , GAUCHERY M.
Published: May 2007

SUMMARY. The peduncle of the chonotrichous ciliate Chilodochona is composed of a bundle of protein fibers secreted by intracytoplasmic glandular ampullae. This process, very different from that involved in production of the peduncle in the peritrichous ciliates, also is found, although with a simpler result, among the Dysteriidae, a highly evolved family of gymnostomes closely related to the chonotrichs.
Le Macronucleus Hétéromere de Quelques Ciliés
Authors: Fauré‐Fremiet E.
Published: May 2007

SUMMARY. In ciliates belonging to the two gymnostome families Chlamydodontidae and Dysteriidae as well as to the order Chonotrichida the macronucleus is composed of two parts which are distinct but in very close juxtaposition. One part, here called “orthomerous,” contains granules or microsomes of desoxyribonucleoprotein and several nucleoli; it thus shows the normal structure of a macronucleus of the ordinary type. The other part, “paramerous,” contains desoxy‐ribonucleic acid diffused, apparently, throughout a homogeneous karyolymph and possesses, in addition, several nucleoli and an endosome of desoxyribonucleoprotein.

The three groups of ciliates under discussion are closely related and constitute an assemblage of forms remarkably evolved. The “heteromerous” structure of their macronuclei must be considered as a secondary acquisition and a differentiation of the “homeomerous” type which characterizes the structure of the macronucleus in most other ciliates.
Studies of Tritrichomonas batrachorum I. The trophic organism*
Authors: Samuels Robert
Published: May 2007

SUMMARY. High variability within cultures of Tritrichomonas batrachorum (from Bufo boreas halophilus, Rana catesbeiana, and Rana pipiens) casts doubt on the validity of length measurements for species designation.

The morphology differs from that described previously. The axostylar capitulum is a complex structure with a preblepharoplastic portion and a perinuclear cup spreading laterally in curved membranes ending in filaments. The parabasal apparatus is Y‐shaped with a very short base.

Two types of amoeboid activity occur. Filopodia are used for anchorage. Their bases migrate and the filopodia may fuse and reseparate as in foraminifers. Ingestion is an amoeboid process utilizing lobopodia. Food adherent to a lobopod is invested in a food cup at the surface. Ingrowth of the lip of the food cup forms the food vacuole, or in cases of cannibalism, constricts the prey and forms a food tube pushing a vacuole before it. Repeated, this produces an alternating series of vacuoles and tubes. There is a pseudo‐amoeboid degenerative process in which the flagella, withdrawn into the cytosome, continue to move and produce non‐functional lobopod‐like protrusions.

An actual cytostome has not been observed, but there is a region of reduced staining intensity ventral to the axostylar capitulum.
Intracellular phagotrophy by malaria parasites: an electron microscope study of Plasmodium lophurae*
Authors: Rudzinska Maria A. , Trager William
Published: May 2007

SUMMARY. An electron microscope study of thin sections of duck erythrocytes infected with Plasmodium lophurae revealed that the so‐called “residual body” is a food vacuole formed by invagination from the cytoplasm of the host cell. Several such food vacuoles may exist in a single parasite. Digestion of hemoglobin evidently proceeds only within these food vacuoles, since they are the only place in the parasite where the characteristic malarial pigment granules may be found. This finding changes the role ascribed to the residual body and gives a new concept of the feeding mechanisms in P. lophurae and other malaria parasites. The cytoplasm of the host is taken in by the parasite by phagotrophy and not only as previously assumed, by diffusion.

The fine structure of P. lophurae shows all major components found in other protozoan and metazoan cells. Some of the organelles appear to have a much simpler structure connected probably with the highly specialized intracellular parasitic life.
Experimental Infections of Various Animals with Strains of the Genus Tetrahymena*
Authors: THOMPSON JESSE C.
Published: May 2007

SYNOPSIS. A comparative study of five species of Tetrahymena, including thirteen strains, was made to ascertain their ability to act as facultative parasites. A variety of experimental hosts, including both vertebrates and invertebrates, were inoculated with axenic cultures of protozoa. Infections were numerous in both larval and adult insects. Tissues of living vertebrates were invaded by one species of Tetrahymena through artificially produced wounds.
Some Observations on Actinosphaerium nucleofilum n. sp., a New Fresh Water Actinophryid.*
Authors: BARRETT JAMES M.
Published: May 2007

SYNOPSIS. A new fresh water species of Actinosphaerium is described, the fourth member of the genus. Some of the more significant of its diagnostic traits are: 1) the Actinophrys‐like nuclei with peripheral nucleolar granules and without central rosette‐shaped nucleoli, 2) the occurrence of some nuclei in the ecto‐endoplasmic border and the insertion of axial filaments on them, and 3) the low ratio of endoplasm to ectoplasm.
Mechanisms of Purifying Amoebae by Migration on Agar Surfaces
Authors: NEFF ROBERT J.
Published: May 2007

SYNOPSIS. Purification by migration on solid agar plates was studied with a small soil amoeba, Acanthamoeba sp., and a large fresh‐water amoeba, Amoeba proteus. Purification seems accomplished largely by two mechanisms: egestion and attrition of contaminating organisms. Digestion may also play a role but probably is less important. The migration method is applicable to motile forms of the two amoebae which differ greatly in volume and motility. Therefore the method may be of potential value in purifying many species. Modifications which should extend the usefulness of the method are considered.
An Eight‐day Method for Screening Compounds against Leishmania donovani in the Golden Hamster*
Authors: STAUBER LESLIE A. , FRANCHINO ELIZABETH M. , GRUN JOHN
Published: May 2007

SYNOPSIS. Intracardial inoculation of 1–10 million L. donovani in 0.1 ml. of ground spleen suspension from an infected animal (hamster) results in a uniform rise of parasite numbers in the untreated animal over the first 8 days after the inoculation. This rise is highly consistent from experiment to experiment.

Treatment is accomplished by parenteral injection of a compound for 6 successive days in this time interval, starting 24 hours after inoculation.

No known active compound in proper dosage (sodium stibogluconate, pentamidine, fuadin) has failed to show a significant suppression of the expected rise in parasite numbers. No known inactive compound has had any effect on the course of the infection.

The dosage‐response curve for the active compounds suggests that the method is a sensitive one. Since it takes only 8 days to complete, it is economical as well.
Gel Diffusion Studies on the Antigens of Isolated Cellular Components of Paramecium*
Authors: PREER J. R. , PREER L. B.
Published: May 2007

SYNOPSIS. A method for the isolation of trichocysts and cilia from whole paramecia is given. Trichocysts, cilia, mitochondria, and other particulates have been identified in homogenates and their numbers in different centrifugal fractions determined. Four antigens extractable from one strain of Paramecium have been studied by gel‐diffusion techniques: Antigen 1, heat‐stable, derived from trichocysts; antigen 2, not associated with any cellular particulate in homogenates; antigen 3, obtained in large quantities from the mitochondria; antigen 4, the antigen correlated with serotype, is derived mainly from the cilia and probably from the body wall and having the properties of a protein.
An Electron‐Microscope Study of the Cytology of the Protozoan Peranema trichophorum*
Authors: ROTH L. E.
Published: May 2007

SYNOPSIS. The flagellate, Peranema trichophorum, has been studied in the electron microscope by thin‐sectioning techniques. The flagella have the fibrillar pattern typical of cilia and flagella, but accessory structures including tapered, intraflagellar rods, striated, layered material on the outside of the membrane, and mastigonemes are present. In the near basal region of the flagellum, there is a swelling of the shaft which is correlated with the absence of the two central flagellar fibrils. The basal portion of the intraflagellar material is structurally and locationally similar to the basal parts of the flagellar fibril bundle; this similarity suggests that the two structures originated from similar precursors and that two kinetosomes comprise the light microscopist's blepharoplast in this organism.

The ridged pellicle is composed of 3 membranes, only two of which follow the contour of the ridges. Several filaments 21 mμ in diameter are localized under the low point of each ridge, and a single, larger fibril which has a periodic structure is often located beneath the high point of each ridge.

The cytostome and structures associated with it are described and discussed in relation to food taking. The pharyngeal rods are cross‐connected and each is composed of numerous tubular elements surrounded by a denser, homogeneous layer. A system of membranes is attached to the rods and extends anteriorly.

The nucleus contains two large nucleoli, numerous rod‐shaped, membrane‐limited bodies which appear similar in structure to bacteria, and a smaller granular component.

Other organelles are briefly described including mitochondria, Golgi bodies, vacuoles, and endoplasmic reticulum.
Bacterial Ingestion by the Rumen Ciliates Entodinium and Diplodinium
Authors: GUTIERREZ J. , DAVIS R. E.
Published: May 2007

SYNOPSIS. In cattle fed a high‐starch diet, species of Entodinium and Diplodinium ingested associated ruminal bacteria. Stained preparations of diluted rumen contents showed Entodinium caudatum, E. minimum, E. dubardi, (syn. E. simplex), E. longinucleatum, E. bursa, E. nanellum, E. exiguum, and E. vorax contained gram‐positive diplococci. Starch grains with adherent gram‐positive diplococci were observed within Entodinium spp. Diplodinium ecaudatum forma ecaudatum, D. ecaudatum forma caudatum, D. neglectum and an unidentified species of Diplodinium also ingested ruminal diplococci. Bacteria were isolated from mixed species of Entodinium by washing and culturing the protozoa in a starch feed‐extract agar medium. The strains isolated from the ciliates were gram‐positive diplococci, 0.8 times 1–1.5 μm, which attached themselves to starch granules and were able to digest the starch. Conclusive evidence of bacterial ingestion by the oligotrichs was obtained by providing the bacterial cultures to Entodinium species (E. dubardi and E. minimum) which had been starved 24 hr. Gram‐stained preparations showed the ciliates readily ingested the bacteria. The amylolytic cocci utilized by Entodinium spp. were identified as Streptococcus bovis.
Lankesterella corvi n. sp., a Blood Parasite of the English Rook, Corvus f. frugilegus L.*
Authors: BAKER J. R. , LAINSON R. , KILLICK‐KENDRICK R.
Published: May 2007

SYNOPSIS. Lankesterella corvi n. sp. (Coccidia, Eimeriidae, Cryptosporidiinae) is described from the rook, Corvus f. frugilegus L. in England. It was found in 36 of 196 fledged rooks less than 1‐year old, but not in 25 nestlings or 38 adults. It was not found in 71 jackdaws (C. monedula spermologus) or in 110 other birds of 16 species.

Mature sporozoites were found in the erythrocytes and occasionally in other blood cells. They were 6.2 times 2.5 μ, with a central, band‐like nucleus, and cytoplasm which failed to stain with Giemsa's stain. Gametogonic and sporogonic stages, found in the bone‐marrow of one bird, resembled corresponding stages of Eimeria.

A fledgling rook was infected experimentally by inoculation of a blood and tissue suspension from an infected bird. Sporozoites appeared in its blood 4 days after inoculation. They appeared to increase slightly in size and their cytoplasm lost its initial affinity for Giemsa's stain during the next few days. Engorged mites (Ornithonyssus sylviarum) from the experimentally infected rock contained unchanged sporozoites but no developmental stages of the parasite. A canary could not be infected by intraperitoneal inoculation and feeding of such mites.
An Illustrated Key to the Higher Groups of the Ciliated Protozoa, with Definition of Terms*
Authors: CORLISS JOHN O.
Published: May 2007

SYNOPSIS. A dichotomous, analytical key is offered for use in recognition and differentiation of the 26 orders and suborders belonging to the two subclasses of the single class Ciliata of the subphylum CILIOPHORA. The basic terminology employed in these brief characterizations, usable in systematic studies of ciliates in general, is defined first, and a plea is made for a more uniform vocabulary, especially in reference to structures which are without doubt homologous throughout the several higher ciliate taxa. Particular emphasis is placed on the all‐important features in the oral area; many of these are figured as well as being described in words.

Both the key and the definitions are essentially the first to be offered since Kahl's monographic work on the ciliates published in 1930–1935. They are demanded by the great accumulation of new pertinent data in the protozoclogical literature of the past 25 years.
Respiration of Colpoda cucullus During Active Life and Encystment
Authors: PIGON A.
Published: May 2007

SYNOPSIS. During encystment of Colpoda cucullus (O. F. Müller) the respiratory rate decreases from about 11.3 × 10‐5μl. O2/hr. (mean value for active form) to about 1.3 × 10‐5μl./hr. (mean for unstable cyst); the process takes about 24 hrs. At the same time the activity of the contractile vacuole is stopped, but there is no correlation in time between the two processes: when respiration is inhibited by 1/2–2/3 the vacuolar activity is hardly changed. The respiration of unstable cysts remains approximately constant at least for 4 weeks. Experiments with methylene blue suggest that inhibition of respiration at encystment may be due to inhibition of terminal oxidase.
Atoxoplasma Garnham, 1950, as a synonym for Lankesterella Labbé, 1899. Its life cycle in the English sparrow (Passer domesticus domesticus, Linn.)
Authors: LAINSON R.
Published: May 2007

SYNOPSIS. All of 99 adult English house‐sparrows, examined in the St. Albans area of Hertfordshire, England, were found to be infected with the organism previously defined by Garnham (1950) as Atoxoplasma. Young birds were found to become infected while still in the nests and as early as 6 days after hatching; there was no evidence to suggest that the parasite was transmitted through the egg. Within a few weeks of leaving the nests, all of 150 fledgling sparrows examined were heavily infected and several trapped birds died from massive infections.

All stages of schizogony were found in the lymphoid‐macrophage cells of the spleen, bone marrow and liver of these birds; later, as the schizogonic cycle abated, gametocytes developed in similar cells of the liver, lungs and kidney. These gametocytes are of the Eimeria type: the zygote nucleus divides to produce an asporous and polyzoic oocyst containing a large number of sporozoites, and after the rupture of the oocyst these sporozoites invade the lymphocytes and monocytes of the peripheral blood.

Transmission of the parasite in the sparrow is thought to take place after the ingestion of infected mites (Dermanyssus gallinae) by the young birds in the nests: unchanged sporozoites were found in smears of these mites that had been fed on infected sparrows. Transmission experiments were impossible due to the complete lack of clean sparrows.

The taxonomic status of Atoxoplasma is discussed. The type of life cycle and the production of asporous, polyzoic oocysts indicate inclusion of this parasite in the Order Coccidiida, Family Eimeriidae, Sub‐Family Cryptosporidiinae Hoare, 1933. After comparison of the two genera, the author concludes that Atoxoplasma must be regarded as a synonym for Lankesterella. Some previously described species of Atoxoplasma are, therefore, transferred to the genus Lankesterella.

The name Lankesterella garnhami nov. sp., is proposed for the parasite in the English sparrow (Passer domesticus domesticus), and Lankesterella serini nov. sp., for that in the canary (Serinus canarius).
Mass Culture of Euglena gracilis
Authors: BACH MICHAEL K.
Published: May 2007

SYNOPSIS.

A method is described whereby large amounts of Euglena cells can be obtained efficiently for enzymological studies. A completely defined, low pH medium which offers relative freedom from contamination is usee The cuh re‐equipment is also usable for the mass culture of many other unicellular algae.
Submicroscopical Aspects of Schizotrypanum cruzi in Thin Sections of Tissue Culture Forms*
Authors: MEYER H. , QUEIROGA L. T.
Published: May 2007

SYNOPSIS.

In order to study the blepharoplast‐kinetoplast region in the adult form of Schizotrypanum cruzi thin sections of this form, obtained in tissue cultures, have been examined with the electron microscope. It has been seen that the kinetoplast is contained in a large spherical, vacuole‐like space, in hich its osmiophilic mass is more dispersed than in the leishmania and crithidia forms, where it is contained in a rectangular, almost linear space. The basal body of the flagellum has been found at the margin of the vacuole, although separated from it. A group of striae in parallel array has been found with regularity in all the trypanosome forms, similar to the structures of the parabasal body in other protozoa, or to the Golgi apparatus of metazoan cells. The significance of this structure for the parasite is discussed.
The Electron Microscopy of Sarcocystis miescheriana Kuhn 1865
Authors: LUDVIK JIRI
Published: May 2007

SYNOPSIS.

Ultrathin sections of Sarcocystis miescheriana were studied in the electron microscope. The banana‐shaped body of the parasite shows a polar ring with a conoid at the anterior conical pole similar to that of S. tenella. Twenty‐two fine fibrils arise from the polar ring passing radially in the pellicle. The anterior third of the cell is filled with sarconemes converging in the conoid. Behind their ends in the center of the cell large osmiophilic central granules can be seen. A large nucleus in the posterior third with a double membrane contains small chromatin granules situated peripherally. Around the nucleus and in the posterior part of the body numerous small vacuoles with osmiophilic walls, as well as mitochondria are observed. The pellicle consists of 2 layers. On the control preparations cytochemical reactions on ribonucleic acid, deoxyribonucleic acid, polysaccharides, glycogen, volutin and fats were performed. The surface of the cyst is covered by a thin layer showing a honey‐comb structure giving rise to a great amount of parallel finger‐like villi surrounding the cyst on all sides. The villi contain many very fine double‐fibrils ending at the bases of villi in the finely granulated plasmatic interior cyst wall which forms also the septa of compartments. The functions of the observed organelles and structures are discussed.
Electron Microscopy of Pinocytosis and Food Vacuoles in Pelomyxa*
Authors: ROTH L. E.
Published: May 2007

SYNOPSIS.

Food vacuoles have been studied in various stages of the digestive process in cultures of Pelomyxa carolinensis and P. illinoisensis after feeding Tetrahymena and Paramecium. The vacuole wall formed immediately after capture of the food organism may be only 100 m/i thick. The changes observed in the food organisms indicate that first the membranes of the pellicle are ruptured, then mitochondria, cytoplasmic matrix, and nucleus are attacked; cilia and trichocysts are more resistant. The food vacuole membrane is involved first in the removal of water from the vacuole, then in transfer of cytoplasmic fluid into the vacuole, and finally in removal of digestion products from ihe vacuole by pinocyt. Vesicles which have been derived from the plasnulf—a b pinocytosis have been observed. They characteristically have a non‐turgid, non‐spherical appearance when located deep m the cytoplasm and are stainable with phosphotungstic acid. Pinocytosis and the function of food vacuole membranes are discussed. It is concluded that at leait two factors contribute to the benefits derived by amoebae from pinocytosis: (1) modification of the plasmalemma membrane near the time when it becomes the pinocytic vesicle membrane, and (2) increased surface area for diffusion.
The Effect of Physical and Chemical Agents on the Oocyst of Eimeria zurnii (Protozoa, Coccidia)*
Authors: MARQUARDT WILLIAM C. , SENGER CLYDE M. , SEGHETTI LEE
Published: May 2007

SYNOPSIS.

A study was made of the effects of solar radiation, temperature, relative humidity, centrifugation, oxygen, pH, and certain chemical agents on the sporulation of oocysts of Eimeria zurnii of cattle. Of various chemical agents and bactericides tested, only HgCl2 exhibited a high level of activity against unsporulated oocysts. Extreme pH values of 1 and 13 did not alter sporulation. Oocysts required at least 10% of the normal amount of oxygen to sporulate at a normal rate. Physical factors found to be lethal for E. zurnii were: sunlight for as short a time as 4 hours, drying at 25% or less relative humidity, and freezing below about ‐7° C. Survival was directly proportional to relative humidity, but within the limits of the observations reported here, there was no correlation with time or temperature. Normal sporulation occurred from about 8° up to 32.5° C. Below 12° the time required for sporulation was exceedingly long, and at 35° sporulation was morphologically abnormal. The optimal temperature for sporulation was about 30° at which temperature some organisms completed the process in 23 hours. Fifty % of the oocysts required 65 hours to begin sporulating at 20° and 36 hours at 25° C.
Two New Species of Coccidia of the Coypu
Authors: PRASAD H.
Published: May 2007

SYNOPSIS.

The literature on the coccidia of the coypu Myo‐ castor coypus Mol is reviewed. Four species of Eimeria have been described in these animals: E. seideli, E. myopotami, E. pellucida and E. coypi. The description of E. coypi is similar to E. myopotami in every respect, except for a little variation in size of the sporocyst It is therefore proposed to consider this species synonymous with E. myopotami, Two new species of Eimeria, E. myocastori sp. now and E. nutriae sp. nov. are now described from the coypu, naturalised n England in England.
The Buccal Organelles in Paramecium aurelia During Fission and Conjugation, with Special Reference to the Kinetosomes
Authors: PORTER E. DWAIN
Published: May 2007

SYNOPSIS.

Stomatogenesis in Paramecium aurelia is shown to involve the lower kineties of the right vestibular wall, the endoral membrane and perhaps the quadrulus. The anarchic field for the new buccal organelles is formed by granules produced from somatic kinetosomes of the right vestibular wall. The endoral membrane becomes incorporated into the buccal anlage and probably regulates orientation and development of the new organelles. A production of heretofore unobserved buccal kinetosomes from the quadrulus is described and it is suggested that these may form the new endoral membrane for the proter.

During conjugation the infraciliature dedifferentiates in the area of fusion between the conjugants. The buccal organelles dedifferentiate at the time of pronucleus formation and transfer. It is suggested that dedifferentiation of structures in the fusion area is caused by a partial solation of the cortex in this area. The dedifferentiation of the buccal organelles results from the solation of the cytoplasm and the cortex of the paroral cone during pronucleus migration. The redifferentiation of the buccal organelles and somatic kinetosomes is suggested to be a recrystallization or gelation of the cortex with the structures re‐forming in their normal positions and not from an anarchic field as at fission.
The Coccidia of the Zorille letonyx (Zorilia) capensis Kaup
Authors: PRASAD H.
Published: May 2007

The literature on the coccidia of the carnivorous mammals of the family Mustelidae has been reviewed. Three species of Isospora are described for the first time from the zoriile, Ictcnyx (Zorilla) capensis (Fam. Mustelidae). Two of these, I. hoogstraali sp. now, and 7. africana sp. nov are considered to be new species, while the third one, I. bigemina var. zorillae var. nov. is recognized as a new variety.
Oxidative Assimilation of Acetate by Euglena. Carbon Balance and Effects of Ethanol*
Authors: DANFORTH WILLIAM F.
Published: May 2007

Oxidative assimilation of acetate by Euglena gracilis was studied using methyl‐ and carboxyl‐labeled radioactive acetate. Of the total carbon utilized, 40% was oxidized to CO2 and 60% was assimilated; 20% of the CO2 produced was derived from the methyl carbon, and 80% from the car‐boxyl carbon of acetate. Seventy % of the carbon assimilated was derived from the methyl carbon and 30% from the carboxyl. The results suggest that assimilation involves decarboxylation of Krebs‐cycle oxalacetate and assimilation of the resulting pyruvate.

In the presence of ethanol a greater proportion of the acetate carbon is assimilated, though the total acetate consumption is almost unchanged.
The Life Cycle and Incidence of Hepatozoon balfouri (Laveran, 1905) in Egyptian Jerboas (Jaculus spp.) and Mites (Haemolaelaps aegyptius Keegan, 1956)*
Authors: HOOGSTRAAL HARRY
Published: May 2007

The incidence of Hepatozoon balfouri (Laveran, 1905) in examined populations of Egyptian jerboas was 41% in Jaculus j. jaculus, 21% in Jaculus o. orientalis, and nil in Allactaga tetradactyla. Infection in a few animals apparently less than 6 days old suggests the possibility of transplacental transmission. The cycle in erythrocytes and parenchyma cells of the liver is described; stages in liver are seldom seen in chronic infections. Blood of many other Egyptian rodents and insectivores was negative for H. balfouri.

The sporogonic cycle in mites, Haemolaelaps aegyptius Keegan, 1956, fed on infected jerboas, resembles that of other typical Hepatozoon species. Sporocysts contain 6 to 16 (usually 12) sporozoites. Infection rates in experimental cultures of H. aegyptius varied greatly. Mites from only a single graphic area could be experimentally infected; in the same area, the infection rate in J. jaculus is significantly higher than elsewhere. Biological races of Haemolaelaps aegyptius, more or less refractive to H. balfouri infection, may exist. Large numbers of mites, lice, fleas, and ticks removed from infected jerboas were uninfected, as were numerous arthropods experimentally fed on infected jerboas.

Owing to the presence of H. balfouri foci in widely differing ecological zones of North Africa and Sudan, different species of mites, and possibly of other arthropods, obviously transmit the infection; details of this likelihood require further investigation.
Donnè Structurales et Ultrastructurales Nouvelles sur la Conjugaison de Paramecium caudatum.
Authors: VIVIER E. , ANDRE J.
Published: May 2007

The morphologic phenomena of the conjugation of Paramecium caudatum are analysed by transverse sectioning of couples at the level of the junction zone. This orientation allows exact determination of the adjacent surfaces (which strongly suggests the absence of a paroral cone) and their relation to the ciliary fields. The modifications of the outer pellicle are studied with the electron microscope. It is shown that cytoplasmic communications occur at the top of the ridges which limit the periciliary depressions. The kinetosomes remain apparently intact but cilia and trichocysts disappear. An active role by the latter organelles is suggested for the union of the two conjugants.
Cytology of Cold Induced Transformation of Octogenic Reproductive Cysts to Resting Cysts in Colpoda maupasi*
Authors: PADNOS MORTON
Published: May 2007

SYNOPSIS. Octogenic reproductive cysts are transformed into resting cysts when returned to optimal temperature following prior exposure to cold (5°C) for at least 36 hours. In the cold, the reproductive process ceases and macronuclei revert to the interphase condition. Transformation to resting cysts is synchronous. Induced encystment is accompanied by excessive macronuclear extrusion and is associated with a loss in division potential, resulting in no division, or 1 or 2 divisions in the induced resting cyst.

These observations support the hypothesis that exposure to cold during a critical period of the predivisional stage may alter reproductive protein synthesis and favor cyst protein synthesis. The extensive macronuclear extrusions associated with this transition suggest their biochemical involvement in the encystment process.
Deoxyribonucleic Acid Synthesis and Distribution During Growth and Amitosis of the Macronucleus of Euplotes
Authors: KIMBALL R. F. , PRESCOTT D. M.
Published: May 2007

SYNOPSIS. Short sections of deoxyribonucleic acid (DNA) in the elongated macronucleus of Euplotes eurystomus were labeled by means of a short exposure to tritiated (H3‐) thymidine to follow by autoradiography the fate of the labeled DNA during amitotic reorganization of the macronucleus. During amitosis the radioactive DNA that was restricted during interphase to short sections of the nucleus is dispersed and becomes evenly distributed throughout each daughter macronucleus.

Although the reorganization bands normally originate only at the ends of the macronucleus, additional bands can start at other places on the macronuclear surface. Bands of the same macronucleus originate with a high degree of synchrony. DNA synthesis is a constant feature of the rear zone of every reorganization band.
Studies on Feeding and Digestion in Protozoa. III. Acid Phosphatase Activity in Food Vacuoles of Paramecium multimicronucleatum
Authors: MULLER M. , TÖRÖ I.
Published: May 2007

SYNOPSIS. Acid phosphatase activity was studied in total mounts and sections of agnotobiotic Paramecium multimicronucleatum by the alpha‐naphthyl phosphate‐hexazotized rosanilin method. Timing was achieved by India ink marking of food vacuoles. Enzyme activity is present in small endoplasmic granules and in the greatest part of food vacuoles. Following an inactive stage (stage I) of an average length of 5 min the activity appears at the periphery of the vacuole, in most cases in the form of granules (stage II). A high activity level (stage III) is attained within 1 1/2 min and maintained for the most part of the vacuolar cycle. The activity disappears only in the latest vacuoles before egestion (stage IV). The appearance of activity is not concurrent with but succeeding to the maximum of vacuolar acidity as ascertained by feeding Congo red stained killed yeast cells. On the basis of these results the food vacuoles may be looked upon as belonging to the lysosomes sensu lato.
The Behavior of Plasmodium berghei Strains Isolated From Relapsed Infections of White Mice*
Authors: COX HERBERT W.
Published: May 2007

SYNOPSIS. A previous study of parasites from relapsed P. berghei infections of mice indicated that the behavior of the relapse parasites differed from that of their parent strain. Experiments have been performed comparing the behavior of relapse and parent parasite infections in mice under two sets of conditions. In one group of experiments the behavior after antimalarial treatments, designed to result in chronic or latent states of infection, was tested. In all, 8 relapse strains were tested against their parent strains in six different experiments which employed 536 mice. It was observed that the mice infected with the relapse strains had a statistically significant greater mortality after the treatments than did mice infected with parent strains. This difference was observed regardless of how the relapse strain had been previously treated, or of what treatment was used in the experiments. In a second group of experiments, the behavior of infections with relapse and parent parasites was compared in normal mice. Five relapse strains were compared to their parent strains in a total of 5 experiments using 356 mice. It was observed that the mean survival time of mice infected with relapse strains was significantly greater than that of mice infected with the parent strains. It is not known whether this apparent difference in the behavior of relapse and parent parasites is related to the mechanism for relapse of P. berghei infections, or is merely a characteristic of parasites that had survived in an immune host.
Euplotes minuta Yocom (Ciliophora, Hypotrichida)
Authors: BORROR ARTHUR C.
Published: May 2007

SYNOPSIS. Euplotes minuta Yocom, 1930, which has not been reported since its original description, was isolated in 1961 from a tide pool on the New Hampshire coast. Specimens from cultures derived from a single individual averaged 54μ long and 28μ wide. The buccal cavity has an average length of 41μ and contains 31–40 membranelles. There are ten fronto‐ventral cirri, five anal cirri, four caudal cirri, and nine dorsal bristle rows. E. minuta is compared with similar species in the genus and found to be a valid species on the basis of presently accepted criteria.
Cellular Responses to Thermal and Photo Stress I. Euglena and Chlamydomonas*
Authors: GROSS J. A. , JAHN T. L.
Published: May 2007

SYNOPSIS. Euglena and Chlamydomonas were cultured in an organic medium in the dark and at several light intensities (15, 60 and 150 ft‐c) at temperatures from 20d̀ to 35d̀C. Below 32.5d̀, growth of Euglena was independent of light. Chlamydomonas was light dependent at all temperatures where growth occurred; there was no growth in the dark, at 15 ft‐c, or at temperatures above 32.5d̀. At 35d̀, growth of Euglena became inversely light dependent; the higher the illumination, the poorer the growth. Multinucleated, giant euglenas were found at 35d̀, a greater percent of abnormal cells appearing at the higher light intensities. Monsters were not observed in Chlamydomonas.

To explain the growth‐inhibiting, monster‐inducing effect of elevated temperatures on Euglena, it is postulated that a dark‐formed thermosensitive protein, essential for normal cell division, is denatured. Light may increase the effect of heat on chlorophyll and the chloroplast, possibly by being converted to intraplastidic heat through the plastid carotenoids, thus having some indirect synergistic role in the phenomenon.