bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparison of Different Criteria for Determining the Effects of Antibiotics on Tetrahymena pyriformis E.*
Authors: GROSS J. A. 
Published: May 2007

SUMMARY. A study was made of the effects of Chloromycetin, Aureomycin and Terramycin on growth of Tetrahymena pyriformis E. Growth was measured by turbidimetry, cell count and cell volume. Data were analyzed to compare growth rates, time to attain half‐maximal growth and growth after 4 days of incubation.Antibiotic levels which yielded approximately 50% inhibition of optical density were as follows: (1) Aureomycin: 1.9 × 10−5M at 4 days and 5.8 × 10−5M for the number of days to reach half‐maximal growth; 50% depression of growth rate was never attained since levels greater than 5.8 × 10−5M were lethal; 4.9 to 5.8 × 10−5M Aureomycin resulted in approximately 40% inhibition; (2) Chloromycetin: 12.4 × 10−5M at 4 days and 23.2 to 31 × 10−5M for growth rate and time to reach half‐maximum; and (3) Terramycin: 1 × 10−4M at 4 days, 1.5 × 10−4M for growth rate, and 1.5 to 2 × 10−4M for time required to reach the half‐maximal point. The diverse results obtained are discussed.Those concentrations of an antibiotic which showed approximately 50% inhibition of growth rate by turbidimetric measurement were then studied for their effect on number of cells during growth. Aureomycin was found to be 66% inhibitory at 4 days, but only 28 and 26% suppressive for growth rate and days needed to attain a half‐maximal population, respectively. Chloromycetin reduced growth 82% at 4 days, inhibited rate of growth by 37% and suppressed time to reach the half‐maximal level by 39%. Terramycin was calculated to be 50% inhibitory at 4 days, 16% suppressive for growth rate and inhibited the time to reach half‐maximal population by 24%.It is also demonstrated that Chloromycetin reduces the size of individual Tetrahymena cells during growth in the culture medium as well as during starvation in buffer.The divers results reported in the literature on the influence of a given antibiotic on Tetrahymena are shown to be caused not only by strain and medium variability, but also, to a great extent, by differences in the methods of measurement and analysis employed. It is suggested that despite certain inherent errors, turbidimetric growth rate is the method of choice for measuring the influence of inhibitors upon total protoplasmic mass.
Homalozoon vermiculare (Stokes): I. Morphology and Reproduction*
Authors: WEINREB STANLEY 
Published: May 2007

SUMMARY. Homalozoon vermiculare (Stokes) is a vermiform holotrichous ciliate of the family Spathidiidae. Its functional ventral side bears 12 longitudinal rows of short cilia. The functionally dorsal side bears a prominent longitudinal ridge, is devoid of cilia, and has very fine pellicular striations. The nuclear apparatus consists of a long folded moniliform macronucleus and several small spherical micronuclei. The contractile vacuoles are variable in number and form a longitudinal row along the functionally right side of the organism.The organism varies from 150 μ to 1500 μ in length and 35 μ to 45 μ in width in its relaxed state. It is highly contractile and its movement resembles that of a turbellarian. The body can be divided into three regions: neck, trunk, and caudal region. The neck region has a cytostome at the anterior end surrounded by a pharyngeal basket and a pair of conspicuous parapharyngeal granular masses at the posterior end. The trunk region is very granular and contains the contractile vacuoles and nuclear apparatus. The caudal region is hyaline and often contains trichite bundles. Free floating trichites are found throughout the organism.Two types of reproduction have been observed. The first type is transverse fission during which the macronucleus separates into two lengths, a new pharyngeal basket forms posterior to the division constriction, and parapharyngeal granular masses develop posterior to the new pharyngeal basket. In the second type of division the cytoplasm condenses in the anterior end of the animal leaving the posterior end very flaccid. The macronucleus then undergoes extensive reorganization followed by the development of a daughter cell from the flaccid posterior region. A new flaccid posterior region grows out of the anterior mass after separation of the first daughter cell and the division process is repeated several times until the remaining portion of the anterior mass disintegrates.
Homalozoon vermiculare (Stokes): II. Parapharyngeal Granules and Trichites*
Authors: WEINREB STANLEY 
Published: May 2007

SUMMARY. The parapharyngeal granular masses of Homalozoon vermiculare (Stokes) are stainable in vivo with Janus green B. The reaction is the same in the case of similar granules which are scattered throughout the trunk region. It is, therefore, assumed that these granules are mitochondrial in nature. These same granules failed to stain with osmic acid or acetic‐carbol‐Sudan III although they took an intense peripheral stain when treated in vivo with very dilute Nile blue sulfate. This indicates that they probably have a peripheral layer of phospholipids which would be expected if they are mitochondrial in nature.The trichites, although not stained by lipid techniques, are stained by mercuric bromphenol blue which confirms their proteinaceous nature. They are swelled by Carnoy's acetic‐alcohol causing them to become less visible in situ. Trichites are found surrounding the cytostome and free‐floating throughout the endoplasm but have not been observed subpellicularly or within the ectoplasm. There are indications that they originate within the endoplasm and do not have a homogeneous structure.
Adaptation by Tetrahymena pyriformis to Potassium Cyanide. I. Adaptive Reversal of Cyanide Inhibition of Growth*
Authors: McCASHLAND B. W. 
Published: May 2007

SUMMARY. A clonal culture of Tetrahymena pyriformis W became adapted to the presence of KCN by prolonged exposure to a KCN‐containing medium. The volume of the adapted cell is about 82% of that of the untreated cell, while the nucleocytoplasmic ratio is greater for the adapted cell (0.040) than for the untreated cell (0.033). If adapted cells are cultivated in the absence of KCN for 72 hours, they regain their original size and the nucleocytoplasmic ratio returns to a normal value. This is taken as indication that changes probably are not due to mutation or selection of cyanide‐resistant forms already present.Normal and adapted cells both have about the same water content (approximately 88% by weight) and specific gravity (about 1.053).Growth of adapted cells is not inhibited by 10−3M KCN to the same extent as that of untreated cells. However, cell division in the adapted cells is more resistant to cyanide than are the processes involved in protoplasmic increase.
The Electron Microscopy of Trichomonas muris*†
Authors: ANDERSON EVERETT 
Published: May 2007

SUMMARY. Thin sections of Trichomonas muris, from the caecum of Mesocricetus auratus, were observed with the aid of the electron microscope in order to determine structural details of organelles of this species.The blepharoplast appears to be limited by a membrane. What seem to be basal granules occur in the blepharoplastic area for the axostyle and the lamellae of the undulating membrane and measure approximately 500 Å in diameter.In cross section the anterior flagella and posterior flagellum are composed of eleven fibrils, two centrally and nine peripherally located. Each fibril measures about 380 Å in diameter.The so‐called “accessory filament” of the undulating membrane is devoid of any filamentous structure and appears to be composed of two differentiated mesh‐work areas. The undulating membrane is composed of a series of lamellae ranging from 300 to 400 Å in thickness. This organelle is attached to the external body surface by fine fibers ranging from 167 to 300 Å in thickness.The costa consists of a series of disks embedded in a matrix. The costa is attached to the internal body surface by what appear to be extensions of the costal disks. These disks are approximately 370 Å in thickness and spaced 490 Å apart.The axostyle is limited by a double, corrugated membrane. The corrugations are about 150 Å in thickness and spaced 110 Å apart. The so‐called chromatic ring is composed of a series of rods approximately 640 Å in thickness.The parabasal body consists of a series of filaments approximately 190 Å in thickness.Mitochondria, spheroidal in shape, are limited by a membrane about 180 Å in thickness. The internal structure consists of a varying number of projections which make this organelle appear in section as a series of compartments.Chromatic granules (paracostal, para‐axostylar, endo‐axostylar and those scattered in the cytoplasm) are irregular in shape and limited by a membrane approximately 200 Å in thickness. These granules typically display a vacuolated internal structure.
A Morphological Description of a Tritrichomonas from the Nasal Cavity of Swine*
Authors: Buttrey Benton W. 
Published: May 2007

SUMMARY. The trichomonad occurring in the nasal cavity of the domestic pig, Sus scrofa, is described and figured. With Heidenhain's iron‐hematoxylin and protargol (protein‐silver) stains, the specific characters are as follows: Pyriform in shape; length 8.8–18.4 μ (average 13.6 μ); width 3.2–8.0 μ (average 4.8 μ); blepharoplast of several granules; three anterior flagella with the longest 10.4–16.8 μ in length ending in knob‐like enlargements; full length undulating membrane with four to six subequal folds and containing marginal and accessory filaments; trailing flagellum 4.8–11.2 μ in length; full length costa with fine subcostal granules; hyaline rod‐shaped axostyle with bulbous capitulum, chromatic ring and conical tip; tube‐like parabasal body 3.2–4.8 μ in length; oval‐shaped nucleus 3.7–5.0 μ in length and 2.2–3.0 μ in width; cytostome; and vacuolated cytoplasm containing food vacuoles.Taxonomy of trichomonads in the respiratory and digestive systems of swine is discussed and the nasal trichomonad is compared with the two different forms of Trichomonas found in the cecum. The conclusion is that the nasal form is of a different species from the trichomonads of the cecum. The close similarity between the nasal form and Tritrichomonas foetus is emphasized. The writer suggests that the nasal form should not be given recognition as a new species until its true relationship with T. foetus is revealed.
Studies of Isolated Blepharisma and Blepharisma Fragments*
Authors: Hirshfield Henry I. , Pecora Pauline 
Published: May 2007

SUMMARY. Isolated Blepharisma undulans were studied for the following: (1) fission rate, (2) mating behavior, (3) giant formation, (4) effects of daily transections. The organisms were maintained at 22°C. and isolated daily for 60 days. Fission rate varied from two divisions a day to one in 29 days. The major factor producing the variation appeared to be the type or amount of food. Frequency of conjugation also varied greatly. Daughters of a single organism will mate within 24 hours after division. Conjugation followed by one division, re‐isolation, then conjugation within 24 hours following a second division occurred within a 5 day period. Giants were produced within 3 days by feeding with Khawkinea, Chilomonas and Paramecium. Paramecium alone did not produce giants. Exposure to 10−m, 10−4M colchicine did not accelerate this process.Daily transections into approximately equal halves were made. The anterior halves containing the mouth membranelles were followed. Fission rate was not affected by cutting. A progressive decrease in size occurred. All ultimately lysed, most on the 7th day. If cutting was suspended on any day, recovery and fission followed. If cutting was re‐instituted, lysis would again occur on or about the 7th day. Daily amputation of the posterior tip for 2 weeks did not affect either size, fission rate, or longevity.
Experimental Infection of the Gray Garden Slug, Deroceras reticulatum (Müller), By the Holotrichous Ciliate Tetrahymena pyriformis (Ehrenberg)
Authors: Kozloff Eugene N. 
Published: May 2007

SUMMARY. To determine whether Tetrahymena pyriformis could infect Deroceras reticulatum and become morphologically modified in the same way as the parasitic phase of T. limacis, 50 slugs were exposed for 10 days to an amicronucleate clone of T. Pyriformis and 50 were exposed for the same period of time to a micronucleate clone. The slugs were then transferred to clean containers for another 10 days, to allow ciliates which had entered the slugs either to persist and multiply or, in the case of transitory infections, to disappear. An additional 50 slugs were kept in a control group for 20 days. All of the slugs had been collected at a single locality in which natural infections by T. limacis had not been noted, and were maintained in separate one‐half pint milk bottles throughout the experimental period.Of the slugs exposed to the amicronucleate clone, 40 survived to the end of the experimental period, and 15 were infected. Of those exposed to the micronucleate clone, 42 survived, and 5 were infected. Forty‐three of the slugs in the control group survived, and none were infected by ciliates. In some of the slugs infected by T. pyriformis, hundreds of ciliates were noted. The infections were apparently limited to the digestive gland, intestinal tract, and fluid around the viscera. Ciliates recovered from slugs were in general smaller than those growing in thriving cultures, but morphologically were typical T. pyriformis. None were observed to have a proportionately smaller cytostome or apiculate anterior end characteristic of the parasitic phase of T. limacis.
A Comparison of the Parasitic Phase of Tetrahymena limacis (Warren) with Clones in Culture, with Particular Reference to Variability in the Number of Primary Ciliary Meridians
Authors: Kozloff Eugene N. 
Published: May 2007

SUMMARY. The number of complete primary ciliary meridians in Tetrahymena limacis found in natural infections in the slug Deroceras reticulatum has been observed to range from 32 to 40. To study the range in the number of meridians in clones in culture, 10 ciliates were pipetted singly from each of two natural infections into sterile 1% (w/v) yeast extract to which 400 units of potassium penicillin‐G and 500 micrograms of dihydrostreptomycin sulfate per ml. had been added aseptically. Ten ciliates were also pipetted from each of these natural infections into infusions of tissue of the digestive gland of D. reticulatum. Altogether, 28 clones (13 axenic clones in yeast extract and 15 bacterized clones in tissue infusions) were established.The shape of ciliates in thriving axenic cultures is generally ovoid or pyriform, and similar to that of ciliates in bacterized cultures. However, ciliates in axenic cultures are sharply apiculate at the anterior end and free from inclusions other than small lipoid granules, and in these respects resemble ciliates of the parasitic phase. The cytostome of ciliates in bacterized and axenic cultures is larger in proportion to the size of the body than it is in the parasitic phase.The ranges in the number of ciliary meridians in ciliates of the two natural infections from which the clones were established were 33 to 40 and 32 to 38, whereas the number of meridians in the clones taken as a whole ranged from 25 to 32. Fifteen of the clones showed extremes of 26 and 30.One of the clones was re‐introduced into D. reticulatum by exposing 50 slugs to a culture of the ciliates for 10 days. The slugs were then transferred to clean containers for another 10 days. Forty‐one of the slugs exposed to ciliates survived the experimental period, and 32 became infected by T. limacis. Forty‐four of 50 slugs in an unexposed control group survived, and none were infected by ciliates. In the ciliates from slugs of the experimental series, the number of complete primary meridians ranged from 28 to 36. However, more than half of the ciliates in the experimental infections possessed incomplete rows, and some individuals had as many as five of these. Ciliates in natural infections and in cultures sometimes have incomplete rows, but rarely show more than one such row. The incomplete rows in ciliates re‐introduced into slugs are considered largely to be incipient segments of future complete rows. They occur most commonly in the post‐oral region, and particularly between row 1 (the so‐called stomatogenous meridian) and the next complete row to the observer's right. It appears, therefore, that the post‐oral region is a zone in which most new rows are proliferated.
Cell Division without Chromatin in Trichonympha and Barbulanympha
Authors: CLEVELAND L. R. 
Published: May 2007

SUMMARY. Oxygen concentrations of 70–80 per cent of an atmosphere destroy all chromosomes of the flagellate Trichonympha provided the oxygen treatment is carried out during the early stages of gametogenesis at which time the chromosomes are in the process of duplicating themselves. This treatment does no damage to the cytoplasm and its organelles. Following the loss of chromosomes, the centrioles function in the production of the achromatic figure, the flagella, and‘parabasal bodies. Then the cytoplasm divides, thus producing two anucleate gametes which make some progress in the cytoplasmic differentiations characteristic of normal male and female gametes of Trichonympha.It is also possible, with somewhat higher concentrations of oxygen, with temperatures slightly above the freezing point and a longer period of treatment, to destroy the chromosomes of resting asexual nuclei in several genera of the flagellates that live in the roach Cryptocercus. So far as one can determine by observing organisms so treated, their cytoplasm and organelles are not injured.
A Biometrical Study of the Oocyst of Eimeria necatrix, a Parasite of the Common Fowl
Authors: BECKER ELERY R. , JESSEN R. J. , PATTILLO WALTER H. , VAN DOORNINCK WILLA MAE 
Published: May 2007

SUMMARY. Measurements of the length and width of a total of 6,915 unsporulated oocysts of Eimeria necatrix from 11 infected chickens revealed a length range of 12.1‐28.9 μ, width range of 10.8‐23.8 μ, and a shape‐index (length/width) range of 1.0‐1.64. The average size range of the samples of 25‐100 oocysts (mean, 66 oocysts) constituting this total and taken on the various days of the patent periods was 15.6–23.9 μ× 13.9–19.5 μ. The lengths, widths and shape indexes of the oocysts constituting such samples usually described unimodal, near‐normal frequency distribution curves.The average size of oocysts issuing from an average chicken on an average day of the patent period of the infection was, with standard deviations, 19.7 ± 1.82 μ× 16.7 ± 1.20 μ. The average standard errors for the length and width were 0.237 μ and 0.158 μ, respectively, in samples of the size indicated. A tendency to increase slightly, though significantly, in size after the first three days of the patent period was noted; also, a slight, though significant, linear increase from the first to the seventh day, inclusive. A slight, though significant, tendency to shorten with the passing of the days of the patent period was detected.Analysis of variance revealed much variation in oocyst size from bird to bird on a given day and for given bird and day combinations, but significant day to day variation was demonstrated for width only. By splitting the variance during the first seven days of the patent period into its parts, it was determined that the mean oocyst size during this period was, with standard errors, 19.59 ± 0.238 μ× 16.63 ± 0.200 μ. Further analysis disclosed that a considerable reduction in oocysts measured could be accomplished, with no loss of accuracy, if fewer measurements were taken per bird and more birds were employed.
Studies on Excystment in the Hypotrichous Ciliate Pleurotricha lanceolata*
Authors: JEFFRIES WILLIAM B. 
Published: May 2007

SUMMARY. Pleurotricha lanceolata was cultured in an aqueous extract of Cerophyl with Tetrahymena sp. as the primary food organism. It was induced to form resting cysts by crowding in the absence of food in a modified Osterhout solution. Cysts formed in this medium remained viable for several months.The morphology of the cysts and of animals undergoing excystment was studied both in the living state and in stained preparations. The excystment process was recorded by camera lucida drawings. These studies revealed no endomictic nuclear reorganization, and no extrusion of nuclear material as had been previously reported.An analysis of certain chemical and physical factors which affect excystment showed the following: the rate of excystment is temperature controlled; increasing the pH of the excystment medium increases the time required for excystment; in low concentrations some aqueous plant extracts are effective excysting agents; dilute solutions of certain plant acid mixtures neutralized with KOH are likewise effective; a number of organic substances, e.g., Bacto‐yeast extract and Bacto‐peptone, are also effective; and the presence of bacteria retards the rate of excystment.
The Induction of Haploidy in Tetrahymena pyriformis Following X‐irradiation.1
Authors: ELLIOTT A. M. , CLARK G. M. 
Published: May 2007

SUMMARY. Vegetative clones of Tetrahymena pyriformis, variety 2, mating type II, were the recipients of various dosages of X‐rays from 10,000 to 400,000r. One clone from the 400,000 level (UM7X), when mated with non‐irradiated cells of various mating types in variety 2, failed to produce a migratory nucleus. A one‐way transfer from the normal to irradiated mate occurred, resulting in the production of haploid exconjugants.When haploids were crossed with diploids the former failed to produce a migratory nucleus. A one‐way nuclear transfer from the diploid to the haploid occurred resulting again in the production of haploid exconjugants. When two haploids were crossed a clone resulted which showed 80 to 90 percent amicronucleate forms.The mating type of the derived haploid is always that of the diploid parent. All derived haploids manifest physiological and morphological characteristics similar to those of the diploid except that the haploids possess a smaller micronucleus.
Les Tentacules d'Ephelota; Etude au Microscope Electronique.
Authors: ROUILLER C. , FAURÉ‐FREMIET E. , GAUCHERY M. 
Published: May 2007

SUMMARY. The central canal of the suctorial tentacle of Ephelota is limited by a fine pellicle composed of numerous longitudinal fibrils and bearing 16–18 membrano‐fibrillar ridges arranged radially in the lumen of the canal. This structure resembles that of the myonemes in the heterotrichous ciliate Stentor.The prehensile tentacle of Ephelota contains 4–6 axial protein fibers each consisting of a lamello‐fibrillar bundle and isolated from one another by thin intracytoplasmic membranes.In both types of tentacle the cytoplasmic portion is immediately limited by a very thin pellicle which is continuous with the “epiplasmic membrane” and covered by the alveolar cuticle which envelops the entire body of the ciliate.
Supplementary Factors in the Nutrition of Euplotes.*
Authors: LILLY DANIEL M. , HENRY S. MARK 
Published: May 2007

SUMMARY. Known chemical compounds have replaced the three supplementary factors previously necessary for the growth of Euplotes patella feeding on Chilomonas paramecium under bacteria‐free conditions. The factor found in an extract of liver was identified as thiamine. The factor supplied by extracts of certain bacteria has been tentatively identified as folinic acid. A combination of 8‐azaguanine and the riboflavin analog, flavotin, has been substituted for the factor found in yeast extracts. Inorganic salts and sodium acetate have been incorporated in the supplementary medium to promote the growth of the flagellate food organisms.Euplotes has also been cultured on Tetrahymena pyriformis in a medium containing 8‐azaguanine and flavotin. The requirement for supplementary growth factors in this carnivorous ciliate has been interpreted as definitely involving intermediates in purine metabolism.