Capsule Expansion Research Articles

Anterior capsule contraction with foldable silicone intraocular lenses

Purpose: To examine the causes, signs, and symptoms of anterior capsule contraction syndrome and the response to neodymium:YAG (Nd:YAG) anterior capsulotomy.Setting: Madigan Army Medical Center, Tacoma, Washington, USA.Methods: This retrospective review comprised 70 cases of phacoemulsification with foldable plate-haptic silicone intraocular lens (IOL) implantation. Patients who developed anterior capsule contraction postoperatively, defined as the anterior capsule being visible through an undilated pupil, had a radial anterior capsulotomy with an Nd:YAG laser. Variables analyzed were visual acuity, subjective complaints, associated inflammation, and IOL decentration.Results: Ten eyes of 9 patients (14%) developed anterior capsule contraction and had Nd:YAG laser radial anterior capsulotomy. Three of 9 patients reported decreased visual acuity and glare. Two other patients had chronic anterior_ chamber inflammation unresponsive to steroids after surgery that resolved after Nd:YAG anterior capsulotomy. Intraocular lens decentration was observed in 3 patients before the Nd:YAG capsulotomy. Posterior lens dislocation occurred in 1 patient after capsulotomy and required surgical lens exchange.Conclusion: One-piece foldable silicone IOLs may not provide enough peripheral capsule expansion.

Phenology and Reproductive Biology of Syntrichia inermis (Bryopsida, Pottiaceae) in the Mojave Desert

Six populations of Syntrichia inermis (Brid.) Hueb. from the Nevada Mojave Desert were sampled every two weeks for a period of one year. Stem elongation rates were very low (0.14 mm yr. -'), with vegetative growth occurring during the winter. Plants were gonioautoicous, with >90% of the plants morphologically bisexual; however, functionally female stems outnumbered functionally male stems. Archegonia were initiated and became receptive in the same winter, whereas antheridia were initiated in the winter and took from one to several years to reach maturity. On an inflorescence basis, the number of archegonia was fewer and less variable than the number of antheridia, with the abortive rate 3-4% for both gametangia. Fertilization occurred during winterlearly spring, with 50% of the current cycle perichaetia becoming fertilized. Embryos were essentially dormant from spring through fall, resuming growth the following winter, when seta elongation and capsule expansion occurred. A protracted late operculum intact phenophase occurred, with spore dispersal beginning in late summerlearly fall. Previously unknown phenological/reproductive features reported for S. inermis include the lowest known rates of stem elongation, gametophytic and sporophytic growth restricted to winter, the longest period of antheridial maturation, a new pattern of antheridial maturation, and a sporophyte maturation pattern that includes 18 + months of dormancy. Phenological studies of mosses began with broad surveys of local floras (e.g., Grimme 1903) and progressed to detailed studies of single species (e.g., Longton & Green 1969). Perhaps the most significant breakthrough in this field occurred when the stages in the life cycle were defined and quantified (Greene 1960). Since then, the dynamics of vegetative growth, gametangial maturation, stem architecture, and sporophyte life history have been presented for a variety of species (e.g., Deguchi & Takeda 1986; Hancock & Brassard 1974; Imura & Iwatsuki 1989; Longton 1979; Miles et al. 1989; Stark 1986; see review in Longton 1990). Such studies often provide data relevant to the evolution of breeding systems, the allocation of resources to sexual reproduction, and the division of effort between sexual and asexual reproduction. The life history features of desert mosses are not well known (Longton 1988; Scott 1982). It is sometimes assumed that bryophytes in the desert are primarily annuals, escaping the heat and dryness by contracting the life cycle into a few months. However, studies on the desiccation resistance of species in the Syntrichia ruralis (Hedw.) Web. & Mohr complex indicated that some species are perennial and able to withstand desiccated conditions for long periods of time without incurring irreparable cellular damage (Bewley 1979; Oliver et al. 1993). Nevertheless, photosynthesis is restricted to periods when the gametophyte is hydrated (Alpert 1979), which are short and intermittent in the American deserts. The phenology of two species in the Pottiaceae has been studied from the Chihuahuan Desert of New Mexico, S. ruralis and Trichostomum sweetii (Bartr.) Stark (as T. perligulatum (Flow.) Zand.). Both of these species were found to be perennial, but differed from one another in several respects. Gametangia were matured in the fall in T. sweetii, vs. the summer for S. ruralis (Mishler & Oliver 1991; Stark & Castetter 1995). In addition, annual stem elongation rates were much higher in S. ruralis, the populations of which were all female and at a higher elevation. Syntrichia inermis [= Tortula inermis (Brid.) Mont.] is known from throughout the American southwest and adjacent Mexico (Flowers 1973; Mishler 1994). This species is common at middle to low elevations in the Mojave Desert, and is a dominant species on soil below 760 m. It is a distinctive species, recognized by the coiled leaves when dry (into a sickle-shape with half the lamina lying horizontal; Weber 1973), autoicous condition, leaf margins recurved from base to apex, leaf apices mucronate, and sporophytes nearly always present (for illustrations see Flowers 1973, p. 203; Mishler 1994, p. 329). When dry, gametophytic plants of S. inermis resemble those of Tortula atrovirens (Sm.) Lindb. [= Desmatodon convolutus 0007-2745/97/13-27$1.6510 This content downloaded from 207.46.13.128 on Tue, 06 Sep 2016 05:44:12 UTC All use subject to http://about.jstor.org/terms 14 THE BRYOLOGIST [VOL. 100

External compression for the prevention of scar capsule contracture--a preliminary report.

One of the many methods that have been suggested for the prevention of capsule contracture is the use of capsule expansion exercises. However, the effectiveness of such treatment has remained controversial and has never been studied in a controlled manner. An experiment was designed to study the effect of intermittent external compression on gel implants in dogs. In adult mongrel dogs 200 cc gel implants were placed subcutaneously on either side of the chest wall. Postoperatively, the dogs were treated with an inflation panel which was held over one implant by a canvas jacket. The other implant served as a control. The implants were evaluated by both applanation and indention tonometry. Treatment continued for three months and the dogs were followed for an additional twelve months postoperatively. Of the original 5 dogs, 2 failed to develop contracture on either side. The remaining 3 developed varying degrees of contracture which was in all cases more severe on the control side. In the twelve months of subsequent follow-up, 2 of these dogs remained soft on the treated side and firm on the control side.

Effect of expansion exercises on capsular constriction around silicone implants

Animal experiments were used to demonstrate that capsule expansion exercises can have a positive effect on capsular constriction around silicone implants.

Evidence on the carbon nutrition of moss sporophytes from14CO2uptake and the subsequent movement of labelled assimilate

(1) The ratio of 14CO2 uptake of fully expanded capsules to that of corresponding gametophytes in the species studied was about 1 : 15 in Mnium hornum, 1 : 35 in Pleurldium acuminatum and around 1 : 1 in Funaria hygrometriea. (2) Translocation of photosynthate from gametophyte to sporophyte took place within 1 to 4 days of exposure to 14CO2; in expanded capsules the final activity was at least equal to that remaining in the gametophyte.(3) In M hornum there was no evidence of reverse translocation from sporophyte to gametophyte.(4) Translocation from gametophyte continued at a high level throughout the expansion and differentiation of the capsule in M. hornum. The activity reaching the sporophyte was approximately proportional to its fresh weight.(5) Both in situ photosynthesis and translocation to the capsule of F. hygrometrica rose to a maximum during the latter part of capsule expansion and ensuing differentiation, subsequently declining as the green tissues of the capsule senesced.(6) Fully expanded (but premeiotic) capsules of M. hornum contributed approximately 20% of the assiinilate necessary for their growth. The corresponding figure for P. acuminatum was about 10%, and for F. hygrometrica about 50%.

Effect of Light and Other Factors on Capsule Expansion in Funaria hygrometrica

Effect of Light and Other Factors on Capsule Expansion in Funaria hygrometrica

Effect of Exogenously Supplied Growth Regulators on Intercalary Meristematic Activity and Capsule Expansion in Funaria

Effect of Exogenously Supplied Growth Regulators on Intercalary Meristematic Activity and Capsule Expansion in Funaria

On the Role of the Calyptra in Permitting Expansion of Capsules in the Moss Funaria

The presence of calyptrae was found necessary for young sporo- phytes of Funaria to develop the ability to form capsules. If the calyptrae were left in place, the sporophytes formed capsules. If the calyptrae were removed the frequency of capsule formation was a function of the length of the sporophytes at the beginning of the experiment. When sporophytes were shorter than 10 mm, capsule formation was postponed indefinitely if calyptrae were absent, and there was a strong tendency for intercalary growth to become indeterminate. Beyond a certain stage, determined by environmental and endogenous factors, 100% of naked sporophytes formed capsules. Setae thickened in the typical way when the sporophytes elongated without calyptrae. The absence of the calyptra had only minor effects on the timing and quality of capsule expansion, once the sporophyte was beyond its early de- velopment. Late in elongation, the absence of the calyptra seemed to promote earlier and more vigorous capsule expansion. But if the calyptra was removed just before the capsule expanded, the speed and vigor of expansion was not altered.

A Time-Course of Sporophyte Development in Funaria hygrometrica Hedw.

After a sporophyte of Funaria hygrometrica becomes evident at the tip of a gametophyte, ca. 65-70 days will elapse before a capsule is ma- tured, under greenhouse conditions. The sporophytes elongate for 2-2.5 weeks. Capsule expansion takes 9 days, and a day later pink coloration begins to appear at the tip of the operculum. The peristome teeth redden when the capsule is in its 12th day. During the 4th week after the start of capsule expansion, chlorosis begins, followed later by a reddening of the capsule and complete ripening. Sporophyte development can be visualized as including an elongation phase, a phase of capsule expansion and other premeiotic developments, and a phase of capsule ripening. The phase in which capsule expansion takes place may be regarded as the vegetative phase of capsule development.

The Effect of the Calyptra on Capsule Symmetry in Polytrichum juniperinum Hedw.

The splitting of the inner, sheathing layer of the calyptra on the sporophyte of Polytrichum juniperinum Hedw. leads to asymmetrical expansion and the development of a capsule that is bilaterally symmetrical and dorsiventral. When unexpanded sporophytes are cultured without the sheathing layer, expansion of the capsule is radially symmetrical. When unexpanded sporophytes are cultured with the sheathing layer intact, the sheath is split and capsule expansion is asymmetrical, as it is in field-grown plants. If capsules that have already become asymmetrical are grown in culture, they develop their later angularity as would be predicted on the basis of their asymmetry. It is concluded that capsule symmetry in Polytrichum is determined by the splitting of the calyptra and the asymmetrical expansion of the erect capsule. In contrast, xThis study was accomplished with the support of National Science Foundation grant GB-6520. 2 Department of Botany, University of Illinois, Urbana, Illinois 61801. This content downloaded from 207.46.13.37 on Wed, 03 Aug 2016 05:50:58 UTC All use subject to http://about.jstor.org/terms 328 THE BRYOLOGIST [Volume 71 capsule symmetry in Funaria is determined as the capsule expands in a horizontal position and is not a function of the splitting of the calyptra. Bopp (1954; 1957a, b) studied the relationship of the calyptra to capsule expansion in moss sporophytes, with special attention to Funaria. He concluded that the calyptra exerts a mechanical restraint on capsule expansion but does not determine the bilateral symmetry of the capsule. The present study is devoted to some observations on the importance of the calyptra in Polytrichum, especially with reference to the determination of capsule symmetry. MATERIALS AND METHODS Sods of Polytrichum juniperinum Hedw. were collected at Portland Arch, Indiana, on April 10, 1968. The collections contained sporophytes with unexpanded, partly expanded, and fully expanded capsules, so that the sequence of events during capsule expansion could be reconstructed. Plants with unexpanded and partly expanded capsules were excised from gametophytes, surface sterilized for two minutes with 5% Chlorox, and planted on Voth's (1943) M5 solution solidified with 1% Difco Bacto-Agar. Unexpanded plants were cultured with and without the inner, sheathing layer of the calyptra. The culture tubes containing the plants were placed under 12 hours of daily illumination at 200 foot-candles under Sylvania Gro-lux fluorescent tubes, at 230C. Funaria hygrometrica Hedw. was obtained from the soil around potted plants in the Botany Greenhouse, on May 20, 1968, and from a border planting on the campus on May 18 and 28. Plants with capsules in various stages of development were examined, and the sequence of events in capsule expansion was reconstructed.

Photosynthesis in Sporophytes of Polytrichum and Funaria

Photosynthesis was measured in excised sporophytes of Polytrichum and Funaria with an infrared gas analyzer. Net photosynthesis was recorded for Funaria, but photosynthesis beyond the compensation point was not demon- strable for Polytrichum. The gametophytes of both genera show net photo- synthesis, and the shapes of the light saturation curves for the gametophytes are similar to those obtained for their respective sporophytes. The distribution of dry weight within the sporophyte was followed during capsule development. In Polytrichum the weight of the seta decreases as the weight of the capsule increases. This is not the case in Funaria. These results establish the importance of seta reserves in the economy of the Polytrichum sporophyte during capsule expansion. Throughout its life, the moss sporophyte remains attached to the gametophyte. It is reasonable to assume that the gametophyte contributes organic compounds to the sporophyte during part or all of the sporophyte's development. The presence of chloro- phyll throughout the young sporophyte (Bold, 1940), and especially in the capsule of the older sporophyte (Haberlandt, 1886), has prompted the question of whether or not sporophytic tissue can contribute to its own nutrition by photosynthesis. This paper is devoted to some preliminary attempts to answer this question by infrared gas analysis for the detection of photosynthesis. MATERIALS AND METHODS