Floral organogenesis of Limnocharis flava

Besides a trimerous calyx and corolla, the mature flower exhibits a polyandric androecium and an apocarpous gynoecium consisting of a whorl of carpels. Yet the primary pattern of the flower is completely trimerous and tetracyclic. After the inception of three sepals and three petals, three antesepalous primary androecial primordia are initiated each of which forms three stamens (i.e. secondary androecial primordia). Opposite these three groups of three stamen primordia, three groups of three carpels are initiated, possibly on three extremely inconspicuous primary gynoecial primordia. Additional carpel primordia are formed in varying numbers between the original three groups. Even before carpel inception, the three primary androecial primordia merge laterally thus forming an androecial ring. Additional stamen primordia arise on this ring first between the three groups of three stamen primordia and then in centrifugal direction as the androecial ring broadens basally. Eventually four whorls of stamens and two to three whorls of staminodia are formed secondarily on the androecial ring which arose from the primary primordia. Morphogenesis and construction of the flowers of Limnocharis flava differs in two major respects from those of all other taxa of the Alismatales studied thus far: (1) there are no stamen pairs primarily associated with the petals, and (2) the first-formed carpel primordia do not alternate with the stamen primordia of the preceding whorl, thus violating Hofmeister's rule of alternation.

Floral development of Aponogeton natans and A. undulatus

The primordia of the floral appendages are initiated in an acropetal succession. Members of the same whorl appear nearly simultaneously. The gynoecial whorl and the two staminal whorls are trimerous, whereas the perianth consists only of two anteriolateral tepals. However, the posterior (adaxial) tepal may be present as an extremely reduced buttress whose growth becomes arrested immediately after its inception. If this somewhat questionable tepal rudiment is included we have a perfectly trimerous and tetracyclic flower with alternation of successive whorls. Subtending bracts of the flowers are completely missing in all developmental stages. While the tepal primordia are dorsiventral from their inception, the stamen and pistil (carpel) primordia originate as hemispherical mounds which become dorsiventral in subsequent stages of development. Each pistil (carpel) primordium becomes horseshoe shaped. As the margins grow up and contact they fuse postgenitally. No cross zone is formed. Placentation is submarginal. In A. natans eight ovules are formed and in A. undulatus only two arise; all ovules are bitegmic. The floral apices have a two-layered tunica up to the stage of pistil formation. The inception of all floral appendages (including the ovules) occurs by periclinal cell division in the second tunica layer. The third layer (corpus) may contribute to the formation of the stamens and pistils. Each appendage primordium receives only one procambial strand which begins to differentiate after the inception of the primordium. The questionable rudimentary tepal buttress lacks a procambial strand. Apparently it does not reach the developmental stage at which procambial induction occurs. From the point of view of floral development, the two species of Aponogeton differ drastically from members of the Alismatales studied so far. Among the Helobiae, the Aponogetonaceae appear to be most closely related to the Scheuchzeriaceae and the Juncaginaceae (Triglochinaceae).

Development of the inflorescence and flower of Sagittaria cuneata

The reproductive region of Sagittaria cuneata is basically trimerous. This trimery is exhibited in the arrangement of the bracts, sepals, petals, pairs of stamens in the male flower, and pairs of staminodia in the female flower. In the male flower after the inception of three sepal primordia, each of the three petal primordia arises with one pair of stamen primordia on an alternisepalous bulge of the floral apex, i.e., a petal–stamen (CA) primordium. Subsequent stamen primordia are formed in alternation with the six first-formed primordia. If, for convenience sake, the first six primordia are referred to as the first whorl of stamens up to four additional whorls may be produced. Depending on the size of the floral bud, the third and fourth whorls (if present) consist of two to six stamen primordia, whereas the fifth whorl (if present) contains one to five stamen primordia. Finally, primordia of pistillodes are formed in varying numbers. In the female flower the presence of CA primordia could not be as clearly established as in the male flower. However, again each petal primordium is definitely associated with a pair of antepetalous primordia. The latter primordia develop into staminodia. In alternation with the first six staminodia six additional staminodia are formed and then again in alternation many whorls of pistils (carpels). Even in the mature flower the basic trimery is reflected in the triangular shape of the globose and massive gynoecium. From a developmental point of view, the male and female flowers are primarily trimerous. The polyandric androecium and the large pleiomerous gynoecium are superimposed on the primary trimery. It appears quite possible that this developmental modification also reflects a phylogenetic derivation. This means that the pleiomerous gynoecium and androecium are not primitive but rather advanced. There is no indication of a spiral arrangement of stamens and carpels.Whereas the foliage leaves, bracts, and sepals are initiated as dorsiventral primordia, the petals, stamens, staminodia, pistils, and pistillodes arise as more or less hemispherical mounds and become dorsiventral thereafter. The vegetative apices, inflorescence apices and the floral apices have a two-layered tunica over a massive corpus. Foliage leaves, bracts, sepals, petals, stamens, staminodia, carpels, and pistillodes are initiated by periclinal divisions in the second tunica layer. In the case of the stamens and staminodia the corpus may also contribute. Ovules are initiated by periclinal divisions of the second layer of the carpel primordium.

Floral development of Butomus umbellatus

The primordia of the floral appendages appear in acropetal succession and develop in the order in which they appear. The primordia of each whorl of appendages are formed in a rapid sequence. After the inception of outer tepal primordia, the floral apex becomes triangular. On each angle, one inner tepal primordium together with the primordia of a pair of outer stamens and an inner stamen is formed. The triangularity of the floral apex might be interpreted as an indication of the formation of petal–stamen (CA) primordia as reported for Alisma and Hydrocleis. If this is the case, the primary pattern of organogenesis of the Butomus flower is trimerous and tetracyclic, i.e. one whorl of outer tepals, one complex of inner tepals and stamens, and two whorls of pistils. The floral apices have a two-layered tunica surrounding a central corpus. The initiating divisions in the formation of all floral appendages occur in the second tunica layer. In the case of stamen primordia, the outer corpus is also involved. Procambial development is acropetal. One procambial strand differentiates into each floral appendage shortly after its inception. Additional procambial strands are formed in the pedicel and the perianth and gynoecium. The relationships of Butomus to the Magnoliidae are discussed.

Floral development of Hydrocleis nymphoides

After the inception of three sepal primordia, three petal-stamen (CA) primordia (bulges) are formed in alternisepalous positions. On each of these bulges a petal is initiated, followed by a pair of stamens relatively high up on the bulge, where it is continuous with the floral apex. Growth extends between the three bulges, thus forming an inconspicuous circular rim around the floral apex. As this rim increases in size, further stamens and eventually staminodia are formed centrifugally on the rim. Five or six carpel primordia are initiated centrally to the first-formed pairs of stamen primordia long before all stamens and staminodia have appeared. In spite of considerable deviations from the trimerous monocotyledonous floral construction, the primary organogenetic pattern is trimerous (with the exception of at least the pentamerous flowers) and it is comparable to the primary patterns found in Alisma, Butomus, and other Alismatales. Thus, the study of the earliest developmental stages reveals a common plan that is elusive in later developmental stages and mature flowers.

Nonspiral androecium and gynoecium of Sagittaria latifolia

Developmental studies do not confirm the general opinion that the androecium or the gynoecium is spiral in Sagittaria latifolia. After the inception of three sepal primordia, three bulges (petal–stamen primordia) are formed on radii alternating with the sepal primordia. On each petal–stamen primordium a petal is initiated and subsequently a pair of stamens in the male floral bud and staminodia in the female floral bud. Next, two antesepalous primordia are formed between the first paired primordia. Further stamens (or staminodia and carpels in the female floral bud) are formed centripetally, more or less alternating with the previous ones at subsequently higher levels.

Floral morphology of the Amaryllidaceae. I. Subfamily Amaryllidioideae

The flowers of the subfamily Amaryllidioideae are similar to one another in that they are fragrant, showy, bisexual, and epigynous with two trimerous whorls of perianth and stamens each, and a compound gynoecium. A single vascular strand supplies the vascular system of both a perianth member and a stamen. It splits into three bundles, one median and two laterals. The former constitutes the vascular supply of a perianth member, while the latter, facing one another right and left, fuse to supply a stamen. This peculiar mode of branching of the vascular strand is considered to be associated with superposition of a stamen upon a perianth member. The corona of Narcissus which is supplied by inversely oriented vascular bundles, is regarded as an outgrowth from the perianth tube and those of Eucharis and Pancratium, which are non-vascular, to represent the stamen cup. Two series of vascular strands differentiate in all members investigated. While the inner series constitutes the placental supply, the strands of the outer series which vary in number in different genera, show various degrees of adnation among the traces occurring on the same radius. The nature of the inferior ovary has been discussed. The nectaries are considered to be of quite advanced type.

The effect of drugs on stress-induced changes of myocardial glycogen and blood glucose concentration in rats

Rats that were subjected to restraint stress for 18 h were found to have reduced myocardial glycogen and blood sugar levels and showed histological changes in heart and adrenals. The effects of alpha-methyl-p-tyrosine, alpha-methyl-dopa, disulfiram and actinomycin D on these stress-induced changes were examined. Of these drugs, only alpha-methyl-p-tyrosine was able to prevent the fall in myocardial glycogen and blood sugar and none of the drugs prevented the histological changes induced by stress.

Floral development of Alisma triviale

The primordia of the floral appendages are initiated in acropetal order. They develop in the same order in which they appear but for the petals, which are retarded in their early growth and mature rapidly shortly before anthesis. While the sepal primordia are dorsiventral from their inception, the primordia of other appendages are of nearly radial symmetry and become more or less dorsiventral in their later stages of development. Each petal primordium together with the primordia of a stamen pair arise on one common petal–stamen (CA) primordium. The many pistil primordia arise on three antesepalous gynoecial bulges and the area between them. Thus, in its development the flower exhibits primarily a tricyclic trimerous plan. The floral apices have a two-layered tunica up to the stage of pistil inception. The initiation of all floral appendages occurs by periclinal divisions in the second layer. The third layer (corpus) may contribute, especially in the case of the petal–stamen primordia and the gynoecial bulges. The development of procambium is acropetal. Each primordium receives a single procambial strand shortly after its initiation. Thus, procambial differentiation occurs as a response to primordial inception and not according to the principle of the conservatism of vascular tissue. Additional procambial strands may differentiate as a response to increase in size. The relationships of Alisma to some ranalian families are discussed. Since the floral pattern of Alisma may be considered as a secondary derivation from a trimerous pattern, it does not appear primitive at all. Other primitive features such as apocarpy and lack of fusion of pistil margins are however retained. Thus, Alisma is a good example for heterobathmy.

Histiocytosis Syndromes of Childhood: A report of four cases

Histiocytosis Syndromes of Childhood (HSC) are a group of rare and diverse disorders characterized by aggressive proliferation or accumulation of cells of monocyte - macrophage system of bone marrow. The clinical spectrum of this syndrome is distinctly varied. The exact pathophysiology of HSC is yet to be determined; however, evidence suggests that one of the subtypes, Hemophagocytic Lymphohistiocytosis, is due to decreased Natural Killer cell activity, resulting in increased activation of other T cell subtypes and production of cytokines. We present four cases of HSC managed at our center between October 2008 & February 2010. Key words: Histiocytosis Syndromes of Childhood; Langerhan’s cell Histiocytosis (LCH); Hemophagocytic Lymphohistiocytosis (HLH); Macrophage Activation Syndrome (MAS). DOI: 10.3126/jnps.v30i3.3923J Nep Paedtr Soc 2010;30(3):171-174