Cytology of colorectal adenomas

A study of the cytological appearances of benign and malignant colorectal adenomatous polyps is reported. The aim of the study was to characterize the cytological features of adenomatous polyps and predict the likelihood of malignancy using cytology. A five grade classification of colorectal cytology has been developed and the characteristic appearances of cells from adenomatous polyps are described. The reproducibility of cytological diagnosis based on this classification has been tested in 120 smears from normal mucosa and adenomatous polyps (including polyp cancers). Correlation with histology was achieved in 88% and correlation of the cytological diagnosis between two observers was achieved in 84%. We conclude that cytology can be used reliably as an adjunct to histology in the assessment of malignancy of adenomatous polyps.     

Hemagglutination and Erythrophagocytosis Associated with the Anemia of Plasmodium berghei Infections of Rats*

SYNOPSIS. The presence of anemia that often seems excessive for the amount of parasitemia in Plasmodium berghei infections had led to the suggestion that autoimmunity might be in part responsible for the anemia. In another erythrocytic infection, Anaplasma marginale of cattle, the association of erythrophagocytosis, autohemagglutination and anemia with infection has led to the suggestion that autoimmunization may occur in anaplasmosis. The possibility that similar findings might be present in P. berghei infections of rats has been investigated. Groups of rats infected with P. berghei were examined at 2–3 day intervals during the course of infection. Red blood cell counts, hematocrit values and percentages of parasitized erythrocytes were determined. The rats were bled at intervals and the sera tested for agglutinins for trypsinized rat erythrocytes. Other infected rats were killed, and their spleens and bone marrow were examined for evidence of erythrophagocytosis. Parasitemia reached a peak on the 9th day of infection and became subpatent by the 14th. The greatest depression in erythrocyte numbers occurred on the 11th day, and the counts remained below normal until the 23rd day. Phagocytized erythrocytes, predominantly uninfected, were found in the phagocytes of the spleen and bone marrow from the 5th through the 21st day. Agglutinins for trypsinized normal rat erythrocytes were present in the sera of the rats in titers as high as 1:64 from the 5th through 14th day of infection. Lower agglutinin titers (1:8) were found from time to time in sera of rats made anemic by repeated bleedings. It is not clear whether these agglutinins are responsible for erythrophagocytosis; however, the fact that predominantly uninfected erythrocytes were phagocytized suggests that the erythrocytes might have been opsonized by an autoantibody associated with the P. berghei infections.     

Early Microspore Divisions and Subsequent Formation of Microspore Calluses at High Frequency in Anthers of Hordeum vulgare L.

The products of first microspore mitosis were studied in anthersof Hordeum vulgare. These anthers were obtained either directlyfrom plants at the binucleate stage or from tillers which hadbeen estimated visually as containing pollen at the mid-uninucleatestage and then pretreated by being clipped off at ground leveland allowed to stand in water for 2 d. In microspores from thelatter plants ten-fold increases in the failure of nuclear differentiation,alteration of the axis of division, or both were observed. Highfrequencies of further microspore response in individual antherswere subsequently induced through culture of the spikes fromthe pretreated tillers in agitated liquid medium. A five toten-fold increase in the percentage of anthers producing macroscopiccallus was observed in these spikes when compared with the controls.It is suggested that nucleo-cytoplasmic disturbances in themicrospores, brought about through the pretreatment period,stimulated the further divisions which eventually resulted inmicrospore callus formation. Microspore calluses were produced most often following an equalfirst division, although when mitosis resulted in differentiatednuclei further divisions of the vegetative nucleus also resultedin callus production. Haploid, diploid, polyploid, and mixaploidmicrospore calluses were produced but no evidence was obtainedto link haploid production with any particular developmentalpathway. Macroscopic calluses which emerged from the culturedanthers were probably mixtures of cell populations derived fromseveral or many different gametic genotypes.     

Density Studies on Lupins. II. Components of Seed Yield

Components of seed yield of cv. Ultra (Lupinus albus L.) andcv. Unicrop (L. angustifolius L.) were measured when grown atthree densities. The low density (10 plants m^–2) Unicropyield (34 g seed per plant) was 1.8 times that of Ultra as ithad more branches, pods and seeds per pod. Ultra seeds (310mg per seed) were heavier than Unicrop seeds (180 mg). The branchingpattern of Ultra was less dependent on plant density, henceat 93 plants m^–2 it gave a higher per plant yield (7.4vs 6.4 g) than Unicrop at lower densities (83 plants m^–2).Density had most influence on pod formation and only small effectson seeds per pod and seed weight. Yield components on the main-steminflorescence were influenced less by density than componentson branch inflorescences. Later formed, higher order generationsof inflorescences were most affected by increased inter- andintra-plant competition. Pod numbers on the main-stem were similarfor both species. Pods formed at higher flower nodes in Unicrop,but the lower flower nodes were less fertile than those in Ultra.Node position of flowers had no influence on seed set in main-stemUnicrop pods, but pods from higher nodes in Ultra formed fewerseeds. Seed weights in Unicrop were similar among main-stemnodes but in Ultra seed weights tended to increase at highernodes. Lupinus spp, lupins, seed yield, planting density     

Developmental anatomy of the tailed frog (As cap hits truei): a primitive frog with large eggs and slow development

The embryonic and early larval development of Ascaphus was studied by culturing embryos at 11 °C. Twenty stages of normal development are morphologically defined by using a standard staging system for anuran amphibians.
Cleavage stages are distinctive. The first cell division is unique because two separate furrows develop and then fuse to form a single cleavage plane. The large, yolky cytoplasm continues to influence cell divisions, and a blastula develops with very large vegetal cells and small, irregular shaped animal cells. There is a conspicuous, translucent blastocoel in the late blastula, and during gastrulation this structure is displayed forward by the internal migration of cells. Except for slight differences in proportions, the gastrula and neurula stages resemble the typical anuran pattern. Circulation (stage 20) begins when large vitelline veins develop on the yolk sac and direct the return of blood flow to the heart.
At hatching, the tadpole has a large yolk sac, little skin pigmentation, and no gills. Mouthparts and opercular coverings of the branchial arches develop slowly. Hind limb buds develop at the base of the tail, but they are soon concealed as a skin membrane develops and covers these structures.
The reproductive strategy for this primitive and highly aquatic frog is unusual: there is a small number of large eggs that develop slowly and produce tadpoles that continue this slow developmental process.     

Epinastic Thresholds in a Simulated Hypogravity Environment

The morphological changes of several grasses, dicotyledons and thallial plants to decreasing increments of gravity from the normal 1 g to 0 g were determined. The various levels of simulated hypogravity were obtained by regulation of the angles of the rotating clinostats. Reaction to simulated hypo-gravity is evidenced by leaf, petiole, stem and coleoptile epi-nasty, root hyponasty in the leafy plants and cereal seedlings and increased lobulation in gametophytes. Threshold response for the gametophyte, marigold, bean and pepper plants was approximately 0.67 x g while that for the wheat, corn and oat seedlings was 0.17xg. The intensity of the epinastic response was found to be inversely related to the gravitational force. With leafy plants, significant responses to reduced gravity are shown only in the presence of light perhaps influencing their ability to synthesize auxin.     

The toxicity to fish of mixtures of poisons: II. Copper-ammonia and zinc-phenol mixtures

Tests with rainbow trout in mixtures of ammonium chloride with copper sulphate and of phenol with zinc sulphate have shown that the threshold of toxic concentration for a 50% mortality occurs in solutions for which a value of I is obtained by summing the concentrations of the individual poisons expressed as fractions of their individual threshold concentrations. With ammonia-copper mixtures this method of predicting the threshold concentration becomes progressively less adequate as lower percentage mortalities are considered.     

Vipera pontica sp.n., a new viper species in the kaznakovi group (Reptilia, Viperidae) from northeastern Turkey and adjacent Transcaucasia

Vipera pontica sp.n. from northeastern Turkey and Transcaucasia is a member of the Vipera kaznakovi group characterized by partial fragmentation of frontal and parietals, sharp canthus rostralis, and a colour pattern on the head of the Vipera dinnicki type. It differs from all vipers in the Near and Middle East in having an upturned but hornless snout, and in a number of scalation and colour pattern characters. It is most similar to the west European V. aspis, but differs in having a yellow green tail tip, more loreals and fewer subcaudals. The affinities to the latter species as well as to V. barani are discussed.