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The effect of different sealing materials (i.e., polyvinyl chloride [PVC] transparent film, and Parafilm [PARA]) for Petri dishes was investigated on shoot regeneration from quince (Cydonia oblonga L.) 'BA 29' leaf-explants. Leaves were excised from proliferating shoot cultures, transversally scored and placed with the abaxial side down in 60-mm Petri dishes containing 10 ml of Murashige and Skoog modified medium, with 5.4 uM naphthaleneacetic acid (NAA), 4.5 uM thidiazuron (TDZ), 200 mg l-1 cefotaxime and 0.25% (wt/vol) Phytagel (IM medium) for shoot-bud induction, and cultured in darkness at 22+2 oC for 28 d. Then the explants were transferred to standard conditions (16-h photoperiod at 30 umol/ m2.s photosynthetically active radiation) on a medium similar to IM, except for lack of NAA, and with 0.65 % (wt/vol) agar instead of Phytagel, for 15 to 28 additional days. The sealing combinations PARA-PARA, PARA-PVC, PVC-PARA and PVC-PVC (in the induction-expression phases) were compared during regeneration and for their carryover effect on shoot development after transfer of explants to an elongation medium (0.9 uM 6-benzyladenine [BA]). Carbon dioxide accumulated at 27.2 mmol/ mol at the end of induction, and gradually decreased from 35.4 mmol/ mol on day 9 to 22.5 mmol/ mol on day 28 of the expression phase in PARA-sealed petri dishes, being always much higher than after sealing with PVC (1-2 mmol. mol-1). Ethylene concentration was 0.1 and 0.04 umol/ mol in the first part of the induction and expression phase, respectively, in PARA-sealed Petri dishes, and slightly decreased with duration of exposure to light during expression; while it was absent in most PVC-sealed dishes. The PARA-PARA and PVC-PVC (induction-expression) combinations gave, respectively, the worst and best results of regeneration and successive shoot development.

Avaliou-se em laboratório a influência de quatro cultivares de batata-doce resistentes a Euscepes postfasciatus Fairmaire e duas suscetíveis, sobre o parasitismo e a biologia de Catolaccus grandis Burks. Seis raízes tuberosas de batata-doce de cada cultivar foram infestadas com adultos de E. postfasciatus durante 40 dias. Após esse período as larvas foram retiradas, pesadas e encapsuladas em parafilme e oferecidas em grupos de cinco, com chance e sem chance de escolha, a fêmeas grávidas de C. grandis por 12h. Foram feitas cinco repetições. Larvas parasitadas e os ovos do parasitóide sobre as mesmas foram contados. Em seguida as larvas foram colocadas em copos descartáveis de 500 ml. Diariamente foram efetuadas três observações para se determinar a duração de desenvolvimento das fases do parasitóide e sua sobrevivência. As fêmeas de C. grandis conseguiram distinguir as larvas de E. postfasciatus criadas em raízes tuberosas suscetíveis e resistentes, preferindo parasitar aquelas criadas sobre raízes tuberosas de cultivares suscetíveis. A sobrevivência de C. grandis foi maior em larvas de E. postfasciatus provenientes de genótipos suscetíveis e o número de fêmeas emergidas do parasitóide foi maior quando as larvas hospedeiras provieram de raízes tuberosas dessas cultivares. The influence of four resistant and two susceptible genotypes of sweet potato to Euscepes postfasciatus Fairmaire on parasitism and biology of Catolaccus grandis Burks were evaluated under laboratory conditions. Six sweet potato roots of each genotype were infested with E. postfasciatus adults during 40 days. After this period the larvae were taken, weighted and encapsulated in parafilm. Five larvae were offered in free choice and no choice tests to C. grandis pregnant females for 12h. Five replications were used. The parasitized larvae and the eggs of the parasitoid were counted. Three daily observations were made to determine the developmental time of phases and parasitoid survival. C. grandis females can distinguish E. postfasciatus larvae reared on susceptible and resistant roots, prefering to parasitize larvae reared on susceptible roots. C. grandis survival was higher when the parasitoid was reared on larvae originated from susceptible roots and the number of emerged females was higher on larvae reared on hosts originated from susceptible roots.

Sols were prepared in the system TMOS:H2O:SOLV:HCl with molar ratios of 1:4:3:0.0005 for SOLV = MEOH and DMF. The sols were cast into cuvettes and covered with parafilm during gelation and aging. The bulk resistance of aged samples was determined by impedance spectroscopy at room temperature. The use of different solvents in the synthesis of silica gels leads to considerable variation in bulk resistance. The results of solvent exchange were found to depend greatly upon the nature of the solvent.

The performances of organic optoelectronic devices, such as organic light emitting diodes and polymer solar cells, have rapidly improved in the past decade. The stability of an organic optoelectronic device has become a key problem for further development. In this paper, we report one simple encapsulation method for organic optoelectronic devices with a parafilm, based on ternary polymer solar cells (PSCs). The power conversion efficiencies (PCE) of PSCs with and without encapsulation decrease from 2.93% to 2.17% and from 2.87% to 1.16% after 168-hours of degradation under an ambient environment, respectively. The stability of PSCs could be enhanced by encapsulation with a parafilm. The encapsulation method is a competitive choice for organic optoelectronic devices, owing to its low cost and compatibility with flexible devices.

When adult males of the smaller brown planthopper, Laodelphax striatellus were fed on 2% crude rice (leaf and stem ) extract containing 15% sucrose there were characteristic stylet sheaths deposited on parafilm membrane. Further bioassays with the butanol-soluble fr. of the extract revealed that it is highly effective for the insects. When the butanol fr. was charged on an ODS open column and eluted in sequence with 20, 40 and 100% m ethanol in w ater, the ODS-40% m ethanol fr. was shown as the most effective one. F urther separation of the ODS-40% methanol fr. resulted in six effective components. These components acted to stimulate very high probing response on L. striatellus only when they are combined. This activity was found to be similar to those of the ODS-40% methanol fr. and the original crude rice plant extract. Two of the active components were identified as tricin 5-O-glucoside and tricin 7-O-glucoside, respectively, through spectroscopic analyses.

Embryogenic tissues were initiated from megagametophyte explants containing precotyledonary embryos. The explants were collected from juvenile cones of two Pinus species, Pinus thunbergii and P . densiflora , in mid and late July. The medium used for initiation was modified DCR medium (inorganic nitrate salts were the same as in DCR but the other components were the same as in MS) containing 1.5 g/l glutamine, 10 μM 2,4- D, 5μM BA, 30 g/l sucrose and 8 g/l agar. The initiation frequencies in Pinus thunbergii and P . densiflora were 8.0 % (31 out of 389 explants) and 2.9 % (3 out of 105 explants), respectively. Embryogenic tissues were subcultured on modified DCR medium containing 1.5 g/l glutamine, 2 μM 2,4-D, 1 μM BA, 30 g/l sucrose, and 8 g/l agar or 4 g/1 gelrite. After one year of the initial culture, eleven P . thunbergii and three P . densiflora embryogenic lines were established. Matured somatic embryos were obtained by using Smith embryo development medium containing 50 μM ABA, 75 g/1 PEG, 60 g/1 sucrose and 5.5 g/1 gelrite. Average numbers of mature somatic embryos per dish were 32 and 22 in best cell lines of P . thunbergii and P . densiflora , respectively. The dishes sealed with permeable paper tape benefited for germination of somatic embryos compared with parafilm. Among modified GD medium Smith embryo germination medium, modified DCR medium, and LP medium, the best performance for germination was carried out by the modified GD medium containing 10 g/1 sucrose and 5 g/1 gelrite. Germination frequency of selected cell lines of both species was ca. 28 %. Regenerated plantlets have been transferred to soil.

For many applications, cells or tissue must be cultured on an optical surface of high quality. For such applications laboratories often prepare "special dishes," which are made by affixing a glass coverslip beneath a hole in a plastic petri dish bottom. In this report, we offer an improved method, using Parafilm as a dry mount adhesive, for the preparation of special dishes, and show that the resulting dish is non-toxic to neurons in culture. The Parafilm bond is stable at 60 degrees C, permitting electron microscopy resins to be poured directly into the dishes and cured. The glass coverslip can be readily removed from the cured resin mechanically. The techniques we describe offer time-saving and reliable improvements for the use of glass coverslips in cell culture and electron microscopy.

The persistence of permethrin (5% a.i.) and pirimiphos-methyl (27% a.i.), applied to the dorsum of calves in the field against Culicoides sonorensis Wirth and Jones (Diptera: Ceratopogonidae), was estimated using a hair-blood-feeding bioassay in the laboratory. Hair clippings were taken before treatment and 3, 7, 14, 21, 28, 42 and 56 days after treatment from the dorsum, side and belly of treated and control calves. Laboratory-reared insects were allowed to feed through thin hair layers and a parafilm membrane on sheep blood warmed using a water-jacketed feeder. Some intoxication after exposure to hair was noted up to 28 days after treatment with permethrin and up to 14 days after treatment with pirimiphos-methyl. Hair from the dorsum caused more intoxication for a longer period than hair from other body regions. Permethrin and pirimiphos-methyl applied to the back did not significantly reduce overall engorgement (body regions pooled) after treatment. Permethrin residues on hair remained far higher on the back than other body regions and were related to insect intoxication and reduction in engorgement in the laboratory. Residues on belly hair never exceeded 12p.p.m. and did not result in significantly reduced feeding at any time. Engorged insects that exhibited sublethal intoxication from feeding through permethrin-treated hair did recover and matured numbers of eggs comparable to controls. Field trials using treated and control calves and enclosure nets showed that dorsal applications of 5% permethrin were not effective in reducing engorgement, despite some intoxication. Vacuum samples from a calf showed that C. sonorensis fed primarily on the belly. A 0.2% permethrin application on the belly (250 ml) did result in > 80% reduction of C. sonorensis in the enclosure nets at 3 and 7 days after treatment, but activity had subsided by 10 days after treatment. The utility of insecticidal treatments for suppression of this vector is discussed.

Diferentes processos de proteção dos garfos foram pesquisados na produção de mudas por enxertia, da mangueira ‘Tommy Atkins’. Os tratamentos utilizados foram os seguintes: saquinho de polietileno (testemunha), filme de PVC, parafilme, cera de abelha, parafina e parafina + vaselina. Verificou-se que o filme de PVC e o parafilme proporcionaram pegamentos de enxertia semelhantes à testemunha (40,60%, 56,62% e 48,33%, respectivamente), enquanto que para os demais tratamentos, os percentuais de pegamento foram muito baixos (< 10%). Conclui-se que o filme de PVC e o parafilme podem ser empregados como opção aos saquinhos plásticos, na proteção dos garfos da mangueira, no procedimento da enxertia. Different processes of graft protection were evaluated in the process of grafting ‘Tommy Atkins’ mango trees. The treatments employed were the following: polyethylene bag (control), PVC film, parafilm, bee wax, paraffin and paraffin + vaseline. It was verified that both PVC film and parafilm presented successful grafting in relation to the control (40.60%, 56.62% and 48.33%, respectively), while the other treatments presented low success rate (

Nodal segments from in vitro culturedPetunia hybrida were grown under varying cultural conditions. The origin of nodal explants influenced vitrification. Basal segments formed a higher percentage of vitreous shoots than did the upper nodes. A method was developed for including polyethylene glycol with Gelrite to obtain gelled media of varying water potentials. Media water potential from −0.31 to −1.2 MPa had no effect on controlling the level of vitrification. Gelrite promoted vitrification but GIBCO agar, alone or in combination with Gelrite, reduced its occurrence. Lowering media NH4 content reduced vitrification, whereas sealing culture vessels with parafilm increased it. As it is now possible to control normal and vitreous plant development inPetunia, this can be used as a model system for studying the physiology and biochemistry of this developmental abnormality.

Unilateral parotid saliva was collected from ten subjects following oral stimulation with water, chewing on parafilm, mastication of celery and bread, and holding of bread in the mouth. Salivary flow induction was independent of chewing rate. Mastication of bread and celery resulted in higher flow rates than did chewing on parafilm. Although limited to two foods at two weights, the results suggest a possible dependence of flow rate on both the type and weight/size of the stimulus. Mastication increased the secretion rate but not the concentration of protein and alpha-amylase. The rate of alpha-amylase secretion was influenced by mastication in accord with digestive function, in that more secretion was induced by food than by nonfood stimuli, more by bread than by celery, and more by larger than smaller pieces of bread. However, these increases might be related more to the physical characteristics than the composition of the stimuli, e.g., force of chewing, dryness, and surface area.

A novel alternative to animal skin models was developed in order to aid in the screening of transdermal penetration enhancers. The skin alternative consists of a dermal layer containing human fibroblasts dispersed in a collagen matrix and an epidermal layer of differentiated and stratified human keratinocytes. Skin alternatives were placed in modified Franz diffusion cells (receptor volume 12 mL, donor area 3.14 cm2, n = 5) and enhancer solution (0.4 M in propylene glycol (PG)) was applied. Following 1 h of pretreatment, 10 microL of saturated hydrocortisone (HC) solution in PG was applied, and the cells were occluded with Parafilm. Samples were removed from the receptor compartment over 24 h, replaced with fresh receptor solution, and analyzed for steroid content using HPLC. Skin HC content was also determined. Receptor concentration at 24 h (Q24) for full-thickness skin alternative (control) was 28.6 +/- 13.7 microM and permeability (P) was 8.3 x 10(-4) +/- 5.5 x 10(-4) cm h-1. Azone (1) produced a Q24 of 105.0 +/- 36.1 microM and a P of 11.3 x 10(-4) +/- 1.8 x 10(-4) cm h-1, while the novel penetration enhancer 1-dodecyl-2-pyrrolidinone (2) produced a Q24 of 164.8 +/- 61.2 microM and a P of 33.3 x 10(-4) +/- 6.6 x 10(-4) cm h-1. Compound 3 produced the highest values for all permeability parameters tested with a P of 48.0 +/- 36.8 cm h-1 and a Q24 of 186.1 +/- 45.1 microM. When compared to the control, compound 1 gave an enhancement ratio (ER) of 3.7 for Q24 and 1.4 for P. Compound 2 gives an ER 5.8 for Q24 and 4.0 for P. These enhancement ratios are similar to those found using HC and human skin.

BACKGROUND/OBJECTIVES: The simplistic definition of a biofilm is a structured community of bacterial cells enclosed in a selfproduced polysaccharidematrix, which adheres to an inert or living surface. Several authors have stated that nearly 2/3 of chronic wounds contain bioburden in the form of biofilms. It has been reported that biofilm-associated infections exceeds $1 billion/year in the US. The purpose of this study was to evaluate the ability of cadexomer iodine dressings to prevent biofilm formation in vitro over a 48 h period using single and mixed species biofilm models. METHODS: Biofilms were grown in a 96-well microtitre plate. The lid was sealed with parafilm and incubated at 37 C for 48 hours. For each dressing tested, replicates were aseptically placed into appropriate wells of a fresh 96-well microtitre plate. Following two wash steps to remove excess stain and subsequent elution of the remaining stain in ethanol, the optical density (OD) at 570 nmwas then measured for each well. The results were grouped into strong biofilm, moderate biofilm, weak biofilm or no biofilm categories. The mixed bacterial species used are common to DUs and PUs. RESULTS: The results indicate that in contrast to a filter paper control (upon which biofilms grew freely) cadexomer iodine prevented biofilm formation against P. aeruginosa, S. aureus and mix species biofilms. CONCLUSIONS: The data suggests that rapid intervention with cadexomer iodine may be useful in preventing biofilm formation in wounds. It is hoped that studies of this typewill allow for enhanced clinician education, patient safety and prove beneficial to facilities with respect to wound care.

Dry bacteriorhodopsin (BR) film was fabricated into sandwich photocell and has differential photocurrent response to rectangular light pulse. And rectification was observed in the dry photocell of indium-tin oxide/BR film/Parafilm/stainless steel, but not of the steel/BR film/Parafilm/ITO. This is an evidence of electrode-mediated rectification. Measurement of equilibrium potential suggests that the working electrode/BR film interface have different property from that of its counter electrode/Parafilm/BR film interface. The interfacial effect of the electrodes may dominate over that of the orientation of BR. Polarities of acid or base induced transient current confirmed the presence of rectification behavior of the electrode. The results will help to understand the mechanism of differential response of BR film.

Head-space volatiles above embryogenicPicea sitchensis (Bong.) Carr. (Sitka spruce) tissues cultured in glass Petri dishes sealed with Parafilm M or cling-film, were captured on Tenax adsorption traps and analysed by gas chromatography / mass spectrometry. Each sealing system released a single major compound into the head-space; butylated hydroxytoluene from Parafilm M and 2-ethyl-1-hexanol from cling-film. After two weeks sealed under Parafilm M butylated hydroxytoluene accumulated to 1.1 μg g(-1) FW in tissues and subsequent somatic embryo maturation was prevented. When butylated hydroxytoluene was supplied via the head-space (100 μg/250 ml flask) 0.5 μg g(-1) FW accumulated in tissues after two weeks and no somatic embryo maturation occurred. Potentially phytotoxic metabolites of butylated hydroxytoluene included a substituted stilbenequinone, butylated hydroxytoluene quinone methide and butylated hydroxytoluene dimer.

A simple device for blood-feeding Aedes (Stegomyia) mosquitoes is described. Parafilm M is stretched and pressed into fiberglass window screen to form a packet for holding warmed blood. The method has been used successfully to maintain Aedes albopictus colonies for >2 yr. In typical blood-feeding trials, 53 ± 0.8% (±SE) of Aedes aegypti (Linnaeus) and 31 ± 6% of Ae. albopictus (Skuse) fed to repletion.

During the last 10 years, blueberry (Vaccinium corymbosum) production in Uruguay has increased to more than 850 ha. From 2005, symptoms of dieback characterized by the death of twigs and branches have been frequently observed in blueberry plants cv. O'Neal in orchards located in Uruguay. Symptomatic 4-year-old plants (cv. O'Neal) were collected and small pieces of necrotic tissues were surface disinfected and plated onto potato dextrose agar (PDA) with 0.2 g liter–1 of streptomycin sulfate. Plates were incubated at 25°C in the dark. All affected tissues consistently developed colonies with white and cottony mycelium, turning slightly yellow after 7 to 10 days. Black acervuli distributed in concentric circles were observed after 10 days. Conidia were fusiform, straight, and had five cells. Basal and apical cells were colorless while the three median cells were dark brown. Conidia (n = 50) had an average of 22.1 (16.5 to 28.2) × 6.6 (5.6 to 7.7) μm. All conidia had one basal appendage of 6.1 (3.9 to 14.3) μm and two to four (usually three) apical appendages of 22.8 (17.4 to 42.9) μm. According to colony and conidia morphology, the isolates were initially identified as Pestalotiopsis clavispora (G.F. Atk.) Steyaert (1). To identify, the internal transcribed spacers (ITS1, 5.8S, ITS2) region of rDNA of a representative isolate (Ara-1) was amplified with ITS1/ITS4 primers (4), sequenced, and compared with those deposited in GenBank. The isolate Ara-1 (Accession No. JQ008944) had 100% sequence identity with P. clavispora (Accession Nos. FJ517545 and EU342214). To confirm pathogenicity, isolate Ara-1 was inoculated onto asymptomatic 1-year-old blueberry plants (cv. O'Neal). Mycelial plugs (4 mm in diameter) from an actively growing colony on PDA were applied to same-size bark wounds made with a cork borer in the center of the stems previously disinfected with 70% ethanol and covered with Parafilm. Control plants were inoculated with sterile PDA plugs. Inoculated plants (five per treatment) were randomly distributed in a greenhouse and watered as needed. After 2 weeks, all stems inoculated with P. clavispora showed brown necrotic lesions 2 to 3 cm in length and 1 to 2 mm deep. White mycelium was observed over lesions. Control plants remained symptomless. The pathogen was reisolated from all necrotic lesions, thus fulfilling Koch's postulates. P. clavispora has been reported as associated with blueberry in Hawaii (3) and Chile (2). To our knowledge, this is the first report of P. clavispora causing dieback disease on blueberry in Uruguay. References: (1) E. F. Guba, Monograph of Pestalotia and Monocheatia. Harvard University Press, Cambridge, MA, 1961. (2) J. G. Espinoza et al. Plant Dis. 92:1407, 2008. (3) L. M. Keith et al. Plant Dis. 90:16, 2006. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

Embryogenic suspensions of 'Chancellor' (Vitis L. complex interspecific hybrid) were bombarded with tungsten particles coated with plasmid pBI426 encoding ß-glucuronidase (GUS) and neomycin phosphotransferase (NPTII) which results in kanamycin resistance. Two d after bombardment, cultures were placed on semi-solid medium containing either 8.6 or 17.2 μM kanamycin. Factors that affect biolistic transformation rates were studied. Tungsten microprojectiles with a mean diameter of 1.07 μm (M10) resulted in more transient gene expression than 0.771 μm diameter particles. Using M10 particles, helium pressures of 1000 and 1200 psi yielded more GUS-expressing colonies per plate than did 800 psi 2 d following bombardment. The number of transformants present after 34 d was not affected by the helium pressure. The distance between the particle launch site and the target cells, and the number of days between the last cell subculture and bombardment, did not affect the numbers of transient and long term GUS expressing colonies. The addition of 3 g/l of activated charcoal to the post-bombardment medium increased long term GUS expression four fold. Wrapping the plates after bombardment with Parafilm increased long term GUS expression three fold compared with plates wrapped with a porous venting tape. With up to 850 transformed callus colonies per plate 23 d after bombardment, the biolistic device holds much promise as a method to achieve stable transformation of grapevines.

A microwell cluster was manufactured with silicone rubber for incubating thin sections for postembedding electron microscopic immunocytochemistry. The small size of the wells requires only minute amounts (as little as 5 microliters) of antisera and other valuable immunoreagents. The capillary action of the wells holds the incubation media and grids in place, even if the cluster is turned upside down, thus facilitating safe transport and storage of the sections to be stained. This silicone rubber microwell cluster can also be used as a die to imprint wells in Parafilm sheets to be used for the same purpose.

The effect of vehicle and occlusion on the in vitro percutaneous absorption of [methylene-14C]-benzyl acetate (1.7-16.6 mg/cm2) has been studied in diffusion cells using full thickness skin from male Fischer 344 rats. Absorption of neat benzyl acetate through rat skin occluded with parafilm was 49.3 +/- 2.0% (mean +/- SD, n = 4) after 48 hr. When benzyl acetate in ethanol was applied to the skin and the skin was occluded with parafilm, the extent of absorption at 48 hr was not significantly different from that after neat application. However at 6 hr, as the ethanol content of the application mixture was increased, the absorption of benzyl acetate through occluded skin was enhanced proportionally (r = 0.999). When phenylethanol was used as a vehicle, the extent of the benzyl acetate absorption through occluded skin at 48 hr was enhanced (P less than 0.05) compared with that after application neat; with 50% (v/v) phenyl-ethanol, absorption at 48 hr was 56.3 +/- 4.9%. However, this enhanced absorption did not correlate with the proportion of phenylethanol in the application mixture. When dimethylsulphoxide was used as a vehicle, the extent of absorption of benzyl acetate through occluded skin at 48 hr was enhanced (P less than 0.05) compared with that after application neat (absorption was 59.3 +/- 3.7% of the applied dose when 50% (v/v) dimethylsulphoxide was used). As the dimethylsulphoxide content of the application mixture was increased, the absorption of benzyl acetate was enhanced proportionally. Occlusion of the skin surface with parafilm often significantly enhanced absorption (P less than 0.05), although the effect varied with time and vehicle. In general, the degree of any enhanced absorption caused by the use of a vehicle or occlusion of the skin was small, and, in most cases, would be unlikely to be toxicologically significant.

Samples of albino mice cerebellar cortex were processed by the cryofracture method for scanning electron microscopy and examined with the field emission scanning electron microscope (FESEM). Albino mouse cerebellar cortex was excised, cut into 1-2 mm slices and inmersed in 4% glutaraldehyde in O. l M phosphate buffer solution, pH 7.4, for 24h at 4°C; and postfixed for 1 h in a similarly buffered 1% osmium tetroxide solution. Specimens were dehydrated in a graded serie of ethanol (30, 50, 70, 80, 90 2x100%) prior to wrapping individual tissue pieces in preformed absolute ethanol filled parafilm cryofracture packets. Rapid freezing of packets was performed by plunging into LN2. First, the packet was transferred from the LN2 storage vessel with LNT chilled forceps in order to avoid themial damage. Secondly, the cooled fracture blade was removed from the LN2, the packet was orientated under the blade, and immediately struck with a heavy tool.

We developed an immunocytochemical protocol in which incubation occurs in a capillary slot instead of the conventional horizontal drop. Slots of constant width were formed by placing slides on top of each other with parafilm spacer layers in between. Cryostat or semi-thin plastic-embedded sections were cut from organs of carcinogen-treated experimental animals. Carcinogen-DNA adducts were visualized in the affected nuclei by a double peroxidase-antiperoxidase method using rabbit antisera specific for certain DNA adducts formed. The staining in capillary slot blocks offered better staining reproducibility than the conventional method. This is particularly important when the staining intensity must be quantified. In addition, handling of the blocks was substantially less laborious than the individual treatment of slides, making this protocol especially suitable for larger series of slides. Other applications for the capillary slot block protocol should be enzyme histochemistry and in situ hybridization.

We developed a simple DNA elution method from agarose gels. After electrophoresis of DNA in an agarose gel, the DNA fragment to be recorved was excised out of gel with a scalpel. The excised gel was placed in the middle of small Parafilm piece, and the Parafilm was folded over the gel piece. Using the petriplate, or thumb, the gel piece was pressed between the Parafilm. Upon squeezing, the DNA inside of the gel gets extruded along with the buffer. The droplets were collected with a pipet. The DNA was then purified by conventional phenol: chloroform extraction method. Typical yields are greater than 50% as determined by UV absorbance.

A simple method has been devised for testing the pathogenicity of fungal pathogens, especially Hirsutella thompsonii, against the coconut eriophyid mite, Aceria guerreronis. Except one or two bracts of the inner whorl of the perianth, under which an active and healthy population of the mite was thriving, the rest of the five or four bracts were removed from a young nut and a suspension of conidia was injected into the thin space between the nut surface and the inner surface of the bract/s by gently lifting the bract/s but leaving it/them intact. The meristematic region of the nut that got exposed after the removal of bracts as well as the retained bract/s were sheathed with a stretched parafilm up to the green portion of the nut in such a manner that there were no gaps. The treated nuts were incubated under ambient conditions. At the end of 96 h, the parafilm was unwound and the bract/s was/were opened to observe infected mites on the inner surface of the bract/s and/or on the nut surface just be...

Optical measurements from epithelial cells grown on clear solid surfaces (e.g., coverslips, petri dishes) are often compared with other measurements (e.g., short-circuit current; I(sc)) obtained from cells grown on opaque porous surfaces (inserts). However, the relative levels of differentiation of cells grown under the two conditions are usually unknown. To address this issue, we grew primary cultures of human tracheal epithelium on solid surfaces or on porous inserts and compared their total levels of protein and deoxyribonucleic acid, electrical properties in Ussing chambers, and ultrastructure. To measure ion transport across cells grown on solid supports, cells were grown on inserts placed on parafilm. Later, separation of insert from parafilm allowed the cells' I(sc) to be measured in Ussing chambers. Four different media were used. Cells grown in one medium showed very low levels of differentiation on all growth supports. In the other media, growth on inserts markedly enhanced differentiation as compared with solid supports. Baseline I(sc) of cells grown on either clear or opaque inserts was at least 30 times greater than that of cells grown on solid supports, though I(sc) with clear inserts averaged approximately 30% lower than that with opaque inserts. We conclude that though differentiation of cells may vary slightly depending on the insert used, cells on any type of insert are much better differentiated than cells grown on solid surfaces. Thus, it is both possible and desirable to make all functional measurements on cells grown on clear porous supports.

Pestalotiopsis funerea (Desm.) Steyaert occurs worldwide and is reported as an opportunistic invader of conifers. It can also be have as a primary pathogen. During the spring of 2001, leaf yellowing was observed on mature and young Cupressocyparis leylandii trees in some nurseries in northern Italy. Symptoms were first observed on twig tips and progressed toward the stem during the summer, resulting in twig dieback and death of branches up to 15 mm. Dark acervuli were present in the cankers. Isolations were made from cankers and necrotic twigs by removing the outer tissue and placing wood slivers from affected tissues on potato dextrose agar. P. funerea was isolated from 88 and 72% of cankers and necrotic twigs, respectively. Four isolates were selected for inoculation tests. Inoculations were made in September on the upper part of stems of 4-year-old pot-grown C. leylandii saplings. The outer layer of the bark (5 × 3 mm) was removed, and a 5-mm-diameter mycelial plug on malt extract agar (MEA) was placed on the wound and covered with Parafilm. Sterile MEA plugs served as controls. The experiment included 20 replications for each isolate and the control. After 4 weeks, 80% of inoculated plants showed bark necrosis or small cankers, or both, and 20% died. P. funerea was reisolated. No cankers developed in the controls. P. funerea was previously reported in Italy on Thuja orientalis L. (2) and from France on C. leylandii (1), but to our knowledge, this is the first report of the pathogen on C. leylandii in Italy. References: (1) M. Morelet. Rev. Hortic. 227:35, 1982. (2) A. Panconesi and G. Vettori. Inf. Fitopatol. 5:37, 1994.

Kenaf (Hibiscus cannabinus L. Malvaceae) presents a source of high-quality cellulose fibers and is being investigated in South Africa for commercial production. In March 2001, 12 5-month-old kenaf plants grown from seed in experimental plots near Bloemfontein, South Africa, displayed large, black, sunken lesions (10 to 20 cm long) at the base of the stem, and severe root rot. A study was undertaken to characterize the pathogen, and to determine the relative susceptibilities of five kenaf genotypes being considered for commercial cultivation. Isolations from diseased tissue on malt extract agar consistently yielded a fungus identified as Pythium group G (1). Four-month-old kenaf plants were artificially inoculated in the field by inserting wooden toothpick tips colonized by the pathogen approximately 25 cm above soil level into the stems of 10 plants of each of five genotypes. Inoculation points were wrapped using Parafilm. The fungus was highly virulent to all five kenaf genotypes in two experiments, with mean cambial lesion lengths of 117, 119, 120, 122, and 139 mm at 7 days after inoculation for Tainung-2, Cuba 108, SF-459, El Salvador, and Everglades 41, respectively. Lesions ranged from 44 to 164 mm, with an overall mean of 124 mm for all five genotypes. No lesions developed in control plants. Although Everglades had the longest lesions, there were no significant differences (P < 0.05) among genotypes. Koch's postulates were completed by reisolating the fungus from all inoculated plants. To our knowledge, there are no published reports of Pythium group G causing stem or root rot of kenaf. References: (1) M. W. Dick. Keys to Pythium. University of Reading Press, Reading, UK, 1990.

A simple, effective method of inoculating Eucalyptus marginata (jarrah) stems with the pathogen Phytophthora cinnamomi was developed. There were four criteria to be addressed when developing this technique. A method was required that did not necessitate the wounding of plant tissue, that simulated surface water ponding (often seen in riplines on rehabilitated mine sites), that was applicable to both glasshouse trials and field trials, and that was less labour intensive than previously published methods. In the development of this new method in the glasshouse, agar plugs, colonised by P. cinnamomi, were placed face-down onto unwounded green stem and periderm of 18-month-old jarrah seedlings. The highest percentage of stems infected was obtained when stems were pre-moistened before the inoculum plug was held in place with wet cotton wool and Parafilm. This technique is simple to use under field conditions.

In the laboratory, 82-99% of late second instar Franklinothrips orizabensis Johansen larvae abandoned avocado branches and artificial branches constructed of wooden dowels and were recovered below branches trapped on tangle foot coated plastic sheets, suggesting a preference by this life stage for selection of pupation sites beneath host plants. Of three media tested (coarse and fine vermiculite, and parafilm cones) for harvesting F. orizabensis pupae in cocoons, parafilm cones were most easily harvestable from colonies, and 44% of deployed late second stage larvae that were recovered used parafilm cones for pupation in experimental cages. Harvesting and shipping trials using aspirated adult F. orizabensis or pupae in parafilm cones showed significant differences in survivorship when held in the laboratory or shipped round trip from Riverside, California to Amherst, Massachusetts. Survivorship of aspirated adults was reduced on average by 41% following shipping, and mortality was highest for adult males. Transit survivorship was increased by 53% if F. orizabensis were shipped as cocoons in parafilm cones. Inclusion of ice packs in polystyrene boxes did not significantly increase survivorship rates for F. orizabensis adults or pupae that were either retained in the laboratory or shipped. This result may have been an artifact resulting from the time of year (i.e., May and temperatures were moderately cool) when shipping trials were conducted.

The palmetto weevil (R. cruentatus F.) breeds in a variety of stressed or dying palms (Giblin-Davis & Howard 1988, 1989). These large (1.9 3.0 cm long) weevils are associated with the native cabbage palmetto, Sabal palmetto (Walter), in Florida (Woodruff 1967). Semiochemicals emanating from stressed or dying palms and male conspecifics (Weissling et al. 1992, 1993, 1994, Giblin-Davis et al. 1994) are attractive to R. cruentatus adults. Although not fully understood, mating apparently takes place on dying palms and females lay their eggs in the leaf bases or directly into the wounds of the host. Larvae develop primarily in the crown region but can occasionally be found in the stem tissue. Last instar larvae migrate to the fibrous stem periphery or petiolar bases and construct cocoons from fiber (Giblin-Davis & Howard 1988). Research on an improved method to culture R. cruentatus has required the collection of a large number of eggs to produce neonate larvae for evaluation of diets. Using pineapple, Anana comosus (L.), as an ovipositional substrate, Giblin-Davis et al. (1989) reported the mean lifetime fecundity of field-collected females as 26 ? 15 eggs per female. However, pineapple proved to be a difficult media to dissect for removal of eggs. More suitable ovipositional substrates were investigated and we found that apple (Pyrus malus L.) slices were easily dissected and were readily accepted by R. cruentatus females. Using apple slices, we reinvestigated the fecundity of R. cruentatus females and determined fertility. Cocoons were harvested in the field from infested palms or in the laboratory from sugarcane (Saccharum officinarum L.) stem (Giblin-Davis et al. 1989). Cocoons were placed individually in covered 100-ml plastic cups with moistened tissue paper (Giblin-Davis et al. 1989) and were stored at 29?C until adult emergence. One male and one female were placed in a 500-ml covered plastic container with moistened tissue. After 48-72 h, males were removed and a slice of apple ('Red Delicious') was added. Slices were thin (5-15 mm; 10-18 g wet weight), convex segments covered by peel. Females oviposit through the apple pulp and most eggs are found along the peel. All containers were placed in an environmental chamber at 290 C with a 13:11 (L:D) photoperiod. Apple slices were usually replaced every 1-3 days until female death. Slices removed from containers were carefully dissected and eggs were removed. This test was repeated five times with four or five females per test (22 females total). Data were converted to the number of eggs laid per female per week. In addition, the total number of eggs laid per female was determined. During two of the tests, eggs removed from apple slices were placed in 15 x 100 mm plastic petri dishes lined with watermoistened filter paper, sealed with parafilm, and placed in the environmental chamber. Neonate larvae were removed from each dish at daily intervals and the dish resealed until all eggs hatched or decomposed. For the first test, fertility was determined every one to three days for 45 d. During the second test, eggs were col

Blueberry shoestring virus (BBSSV) was monitored in late instars of Illinoia pepperi by dot-enzyme-linked immunosorbent assay, a silver-enhanced colloidal gold immunosorbent assay, and dot-hybridization. Aphids acquired BBSSV antigen and BBSSV RNA at a rapid rate during the initial 24-h acquisition access period (AAP) from Parafilm sachets containing purified BBSSV, but the acquisition rate leveled off and declined thereafter during subsequent AAPs at intervals of up to 96 h (...)

The effects of chewing Parafilm and cheese following sucrose rinsing on human dental plaque pH and plaque fluid organic and amino acid concentrations were investigated. Immediate increases in plaque pH were observed following chewing with concomitant decreases in lactate and acetate concentrations and increases in the concentration of formate and many amino acids. Chewing with cheese when compared with Parafilm resulted in significantly higher (p less than 0.05) plaque fluid concentrations of most amino acids, although significant decreases (p less than 0.05) in phosphate, succinate, and acetate concentrations were observed. However, no significant difference in the levels of formate, lactate, and propionate were found between the two chewing treatments.

Water loss in hull and the effect of aerial humidity on the development of kernel were investigated. The results obtained are as follows: 1. The rate of water loss in the hull after detaching from panicle decreased, as ripening proceeded in both fertile and sterile grains. 2. The rate of water loss differed among sterile, fertile grains, and hull of fertile grains, being higher in the following order: sterile grain>hull of fertile grain>fertile grain. 3. The rate of water loss was much lower in normal than in malformed grain. 4. The water loss in panicle was affected by SiO2 application and it was higher in detached panicle in plots without SiO2 application. 5. By glume top clipping, the development of the kernel was inhibited very severely. But even though the top of glume was clipped, the development of kernel was not prevented so severely under high aerial moisture conditions. And even under the same moisture conditions, when the glume-top-clipped kernel was covered with a parafilm bag, the development of the kernel was better than that without covering of parafilm bag. From these results, it was shown that in the ripening of rice plant, the hulls play an important role in keeping high moisture condition in grain, thus enabling the kernel to achieve a normal development.

Rhodnius prolixus Stȧl was successfully reared for three generations on a diet of defibrinated pig blood fed through Parafilm or silicone-rubber membranes. Reproduction in terms of the number and sizes of eggs produced was superior to, while survival from egg to adult was equal to that reported for, insects fed on live hosts. The technique appears equally applicable to the rearing of Panstrongylus megistus (Burm.), Triatoma infestans (Klug) and T. brasiliensis Neiva. The inadequacy of cow blood as a diet for R. prolixus was manifested in a decrease in adult size after two generations and in a reduction of egg weight from 30 to around 16 mg per female per week. This was accompanied by a corresponding reduction in egg hatch from 90 to about 50%.

Two different types of morphogenesis are induced in vitro in the grapevine by changing the system of sealing the culture tubes (with or without Parafilm). The differences appear mainly in the degree of miniaturiation: the plants the most miniaturized, those with Parafilm, have all the characteristics of an immature juvenile state. The others, without Parafilm, show an intermediate morphology between the adult and the juvenile forms. It follows then that the importance of juvenile characters is linked to the degree of miniaturization. One of the effects of Parafilm is in the modification of the amount of CO2 in the atmosphere of the tubes: in excess during the dark phase and in severe shortage during the light phase. We have found then, that among all the environmental factors which could influence the morphogenesis of the grapevine in vitro, CO2 appears to play a relatively important role.

A rapid-cycling line of Brassica compestris L was grown from seed to maturity in vitro. Ethylene accumulated in culture containers throughout the growth period when these were tightly sealed (i.e. closed with aluminum foil, tight plastic caps, parafilm or rubber stoppers), whereas no C 2 H 4 was detected in vented containers (i.e. closed with foam or cotton plugs, or loosely fitted plastic caps). Under both closure conditions, mean levels of CO 2 , O 2 and N 2 were similar to atmospheric levels. The accumulation of C 2 H 4 in sealed containers was associated with inhibition of plant development. Plants grown in a sealed condition had swollen hypocotyls, fewer and smaller leaves and either abortive flowers or no floral buds whereas plants in vented containers developed normally to maturity. Significant reversion to normal development was observed when plants growing in sealed containers were treated with 2,5-norbornadie e (NBD), an anti-C 2 H 4 compound. Treatment with NBD offers a promising way of regulating C 2 H 4 effects in vitro.

Bloodfeeding, egg production and eclosion of Aedes aegypti (L.) fed citrated horse, sheep, or rabbit blood through a Parafilm membrane, with and without a phagostimulant (CO2), were compared with live host (rabbit) fed Ae. aegypti. Laboratory-reared Ae. aegypti were bloodfed for 30 min, 3 times/week for 18 weeks. Citrated mammalian bloods in a glass feeder were warmed to 37°C by a heater/circulator, and offered to the mosquitoes through a stretched Parafilm membrane; dry ice was placed beside the feeders during the final 9 weeks of the study. A significantly lower percentage (47–70%, P < 0.0001) of Ae. aegypti engorged during membrane bloodfeeding than during live host bloodfeeding resulting in significantly lower egg production (P < 0.0001) and egg eclosion in membrane bloodfed insects. Of the in vitro fed mosquitoes, mean egg production was highest in citrated horse blood fed females during weeks 1–9. With the use of CO2 during the last 9 weeks, there was a significant increase in the mean number of mosquitoes engorging on citrated sheep and rabbit blood (P < 0.0001) with a corresponding increase in mean egg production (P ≤ 0.0001). Even though egg production decreased with membrane bloodfeeding, this study suggests that Ae. aegypti colonies can be successfully maintained on a variety of preserved mammalian bloods fed through a Parafilm membrane.

A successful technique for feeding colonies of Glossina morsitans morsitans Westw. and G. austeni Newst. in the absence of living hosts is described. Insects are fed through membranes made of silicone rubber or of agar and Parafilm, overlying blood pools poured onto grooved glass plates. The diet employed is fresh pig blood, collected at slaughter, and aseptic procedures are adopted at every stage of diet preparation and presentation. The reproductive performance of these in vitro-fed colonies in terms of adult survival, fecundity, and offspring size, is the same as that of colonies fed on living hosts, when compared over a long period of time. The fact that the technique is successful when used with a diet of pig blood, but is not successful when used with cow blood prepared in the same way, suggests that the technique per se is adequate to elicit a normal feeding response from these tsetse species. The nature of the nutritional superiority of pig blood is not understood.

The females of the aphidophagous gall midgeAphidoletes aphidimyza (Rond.) lay their eggs on artificial substrates supplied with aphids and honey-dew. If muslin, parafilm and filter paper were offered simultanously, muslin was preferred for oviposition.

The effect of leaf cuticle on probing behavior by bayberry whitefly, Parabemisia myricae (Kuwana), was studied by enzymatically removing cuticles from young and mature lemon ( Citrus limon (L.)) leaves and using the isolated cuticles as membranes over sucrose solutions. Duration of probes by whiteflies on sucrose solutions covered by young cuticles or stretched Parafilm was significantly greater than on those covered by mature cuticles. Differences between young and mature cuticles were similar to differences previously observed between young and mature leaves. Because media beneath cuticles was the same for both young and mature cuticles, the data suggest that reluctance or inability of bayberry whitefly to feed on mature lemon leaves was the result of properties of leaf cuticle. Experiments using Parafilm as a “neutral” membrane suggest that inability of whiteflies to feed through mature cuticles results from inhibitory properties of mature cuticle rather than lack of probing stimulants.

It is well known that a liquid exposed to relatively low intensities of MHz ultrasound may or may not cavitate depending upon a variety of non-acoustic factors. This paper shows that in some cases the material used as the acoustically transparent window and even the length of the sample chamber may also be important factors. Cling film, dialysis membrane and Parafilm are all equally acceptable as acoustically transparent windows for ultrasound, whereas glass cover slips of 'soft' surfaces (in which active bubbles may embed themselves) are not. All the results obtained confirm the validity of bubble recycling as being the dominant mechanism responsible for the enhancement of cavitational activity commonly observed when the sample change is rotated.

Wild-caught female horseflies, Tabanus nigrovittatus Macq. (Diptera: Tabanidae), were presented solutions of seven analogues of ATP in 0.15 m NaCl, or various blood fractions, either as free liquids at 22 or 38dC or covered with a Parafilm M membrane at 38dC. Warming the diet, so that it can stimulate the insects' heat receptors, or presenting it warmed and covered with a membrane, which the flies can pierce and thus deploy their mouthparts as they would when blood-feeding, enhances the response to gorging stimulants. ADP (ED50 45 μM) was the most potent chemical phagostimulant. There were no significant differences between the potencies of AMP, A(TETRA)P, AMP-PCP, AMP-PNP or AMP-S, which were 3.5-5 times less potent than ADP. Cyclic AMP had no phagostimulatory activity at concentrations of 400 or 1000 μM. The ED50 for washed red blood cells (RBC) in saline was 4.5% (one tenth the concentration found in blood). RBC-free plasma caused only 10% gorging but plasma with 0.5% RBC caused 61% gorging, indicating synergism between RBC and plasma.

The effects of temperature and concentration of Mipcin (o-cumenyl methylcarbamate) on the imbibed amount by the brown planthopper, Nilaparvata lugens, and the green rice leafhopper, Nephotettix cincticeps, through rice plant and parafilm were examined by the tracer technique during 24 hr period after caging. Dietary and root dipping solutions including the sub-lethal concentration of 0.2 and 1.0 ppm 14C-labelled Mipcin for the brown planthopper and 1.0 and 10 ppm for the green rice leafhopper were used at ambient temperatures of 25 and 30°C. In the case of the brown planthopper, the imbibed amount through the plant dipped with 1.0 ppm of Mipcin solution at 25°C was lowest, 3.5μl/head/day, and the others were in the range of 6.7-8.2μl. Imbibed amount through parafilm changed from 0.8 to 2.2μl, depending on the concentration and temperature. In the case of the green rice leafhopper, imbibed amount through the plant was in the range of 6.2-8.0μl, almost independent of the Mipcin concentration and temperature. Imbibed amount through parafilm was a minimum of 2.9μl at 10 ppm of Mipcin at 25°C and a maximum of 5.3μl at 1.0 ppm of Mipcin at 30°C.

Descriptions of two membrane-feeding systems for direct observation of leafhopper probing and feeding behavior are presented. One system is for use with modified compound microscopes, the other with standard stereomicroscopes. Basically, leaf-hoppers within an insect chamber are allowed to probe through a parafilm membrane into a feeding chamber containing diet comprised of distilled water with 5% sucrose to stimulate ingestion, methylene blue to stain the salivary sheath, and India ink particles to indicate flow of solution into or out of the maxillary food canal of the stylet bundle. Preprobing activities, flange formation, stylet penetration, sheath formation, ingestion, and egestion are reported as they were observed at high magnification from the diet side of the membrane. Detailed observations of the membrane feeding behavior of leafhoppers, especially the aster leafhopper, Macrosteles fascifrons (Stal), revealed that these insects usually egest material from the foregut (maxillary food canal, cibarial sucking pump, pharynx, and esophagus) one or more times during feeding. Initial periods of egestion are nearly always preceded by periods of prolonged ingestion. Periods of intermittent egestion sometimes lasted for as long as 10 min, and insects often egested shortly before terminating probes. When egestion occurs, materials flow out of the stylet food canal in the same steady manner in which they enter it during ingestion, indicating that the sucking pump is able to function normally in either direction. At times, egestion obviously served to free the sheath and food canal openings of blocking particles. Evidence of leafhopper egestion, along with very recent electron microscopical observations of virus retention sites in the foreguts of leafhopper vectors, is interpreted as confirming the previously proposed hypothesis that leafhoppers transmit semipersistent viruses, such as maize chlorotic dwarf virus and rice tungro virus(es), and other noncirculative plant pathogenic pathogens via an ingestion-egestion mechanism.

The potential of photoacoustic spectroscopy (PAS) for the study of marine organic films has been assessed. It is shown that PAS can be used at the solid/liquid interface to detect the presence of a primary bacterial film formed from seawater. Data for several types of organic films on Parafilm are presented. Data can be obtained in situ as the film is forming under water, or subsequent to film formation on the dried film. The technique is especially useful for detecting organic films on surfaces that are neither optically reflective nor transparent. It is concluded that further development of the technique is warranted to complement existing thin film analysis methods often requiring reflectivity or transparency or both and to increase the signal-to-noise ratio of data from the water cell so that PAS can be used to distinguish various components of a seawater organic film.