Indices of airway resistance and reactance from impulse oscillometry correlate with aerosol particle emission in different age groups

Airborne transmission of pathogens plays a major role in the spread of infectious diseases. Aerosol particle production from the lung is thought to occur in the peripheral airways. In the present study we investigated eighty lung-healthy subjects of two age groups (20-39, 60-76 years) at rest and during exercise whether lung function parameters indicative of peripheral airway function were correlated with individual differences in aerosol particle emission. Lung function comprised spirometry and impulse oscillometry during quiet breathing and an expiratory vital capacity manoeuvre, using resistance (R5) and reactance at 5 Hz (X5) as indicators potentially related to peripheral airway function. The association between emission at different ventilation rates relative to maximum ventilation and lung function was assessed by regression analysis. In multiple regression analyses including age group, only vital capacity manoeuvre R5 at 15% to 50% of end-expiratory vital capacity as well as quiet breathing X5 were independently linked to particle emission at 20% to 50% of maximum ventilation, in addition to age group. The fact that age as predictive factor was still significant, although to a lower degree, points towards further effects of age, potentially involving surface properties not accounted for by impulse oscillometry parameters.

Lung aerosol particle emission increases with age at rest and during exercise

Airborne respiratory aerosol particle transmission of pathogens such as severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), influenza, or rhinoviruses plays a major role in the spread of infectious diseases. The infection risk is increased during indoor exercise, as aerosol particle emission can increase by more than 100-fold from rest to maximal exercise. Earlier studies have investigated the effect of factors such as age, sex, and body mass index (BMI), but only at rest and without taking ventilation into account. Here, we report that during both rest and exercise, subjects aged 60 to 76 y emit on average more than twice as many aerosol particles per minute than subjects aged 20 to 39 y. In terms of volume, older subjects emit on average five times as much dry volume (i.e., the residue of dried aerosol particles) than younger subjects. There was no statistically significant effect of sex or BMI within the test group. Together, this suggests that aging of the lung and respiratory tract is associated with an increased generation of aerosol particles irrespective of ventilation. Our findings demonstrate that age and exercise increase aerosol particle emission. In contrast, sex or BMI only have minor effects.

Fundamental protective mechanisms of face masks against droplet infections

Many governments have instructed the population to wear simple mouse-and-nose covers or surgical face masks to protect themselves from droplet infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in public. However, the basic protection mechanisms and benefits of these masks remain controversial. Therefore, the aim of this work is to show from a fluid physics point of view under which circumstances these masks can protect against droplet infection. First of all, we show that the masks protect people in the surrounding area quite well, since the flow resistance of the face masks effectively prevents the spread of exhaled air, e.g. when breathing, speaking, singing, coughing and sneezing. Secondly, we provide visual evidence that typical household materials used by the population to make masks do not provide highly efficient protection against respirable particles and droplets with a diameter of 0.3-2 μm as they pass through the materials largely unfiltered. According to our tests, only vacuum cleaner bags with fine dust filters show a comparable or even better filtering effect than commercial particle filtering FFP2/N95/KN95 half masks. Thirdly, we show that even simple mouse-and-nose covers made of good filter material cannot reliably protect against droplet infection in contaminated ambient air, since most of the air flows through gaps at the edge of the masks. Only a close-fitting, particle-filtering respirator offers good self-protection against droplet infection. Nevertheless, wearing simple homemade or surgical face masks in public is highly recommended if no particle filtrating respiratory mask is available. Firstly, because they protect against habitual contact of the face with the hands and thus serve as self-protection against contact infection. Secondly, because the flow resistance of the masks ensures that the air remains close to the head when breathing, speaking, singing, coughing and sneezing, thus protecting other people if they have sufficient distance from each other. However, if the distance rules cannot be observed and the risk of inhalation-based infection becomes high because many people in the vicinity are infectious and the air exchange rate is small, improved filtration efficiency masks are needed, to take full advantage of the three fundamental protective mechanisms these masks provide.

Siblings of children with life-limiting conditions: psychological adjustment and sibling relationships

BACKGROUND

This study explored psychological adjustment and sibling relationships of siblings of children with life-limiting conditions (LLCs), expanding on previous research by defining LLCs using a systematic classification of these conditions.

METHODS

Thirty-nine siblings participated, aged 3-16 years. Parents completed measures of siblings' emotional and behavioural difficulties, quality of life, sibling relationships and impact on families and siblings. Sibling and family adjustment and relationships were compared with population norms, where available, and to a matched comparison group of siblings of children with autistic spectrum disorder (ASD), as a comparable 'high risk' group.

RESULTS

LLC siblings presented significantly higher levels of emotional and behavioural difficulties, and lower quality of life than population norms. Their difficulties were at levels comparable to siblings of children with ASD. A wider impact on the family was confirmed. Family socio-economic position, time since diagnosis, employment and accessing hospice care were factors associated with better psychological adjustment.

CONCLUSIONS

Using a systematic classification of LLCs, the study supported earlier findings of increased levels of psychological difficulties in siblings of children with a LLC. The evidence is (i) highlighting the need to provide support to these siblings and their families, and (ii) that intervention approaches could be drawn from the ASD field.

Macroscopic three-dimensional particle location using stereoscopic imaging and astigmatic aberrations

This Letter presents a stereoscopic imaging concept for measuring the locations of particles in three-dimensional space. The method is derived from astigmatism particle tracking velocimetry (APTV), a powerful technique that is capable of determining 3D particle locations with a single camera. APTV locates particle xy coordinates with high accuracy, while the particle z coordinate has a larger location uncertainty. This is not a problem for 3D2C (i.e., three dimensions, two velocity components) measurements, but for highly three-dimensional flows, it is desirable to measure three velocity components with similar accuracy. The stereoscopic APTV approach discussed in this report has this capability. The technique employs APTV for giving an initial estimate of the particle locations. With this information, corresponding particle images on both sensors of the stereoscopic imaging system are matched. Particle locations are then determined by mapping the two particle image sensor locations to physical space. The measurement error of stereo APTV, determined by acquiring images of 1-μm DEHS particles in a 40 mm×40 mm×20 mm measurement volume in air at Δxyz→0 between two frames, is less than 0.012 mm for xy and 0.025 mm for z. This error analysis proves the excellent suitability of stereo APTV for the measurement of three-dimensional flows in macroscopic domains.

Three-dimensional location of micrometer-sized particles in macroscopic domains using astigmatic aberrations

This Letter presents a theoretical and experimental image formation study in the presence of astigmatic aberrations. A three-dimensional, macroscopic location scheme of micrometer-sized particles for the single camera astigmatism particle tracking velocimetry (APTV) technique is introduced. Average particle z position determination errors of the technique are as low as 0.33%, with a measurement depth of 40 mm. These accuracies show APTV's ability of measuring volumetric velocity fields in macroscopic domains with limited optical access.

Challenging symptoms in children with rare life-limiting conditions: findings from a prospective diary and interview study with families

AIM

The aim was to describe the nature, frequency, severity and management challenges of symptoms in children with two rare life-limiting conditions [Mucopolysaccharide (MPS) and Batten disease].

METHODS

This was an embedded mixed-method study set in the UK between 2009 and 2011. Twenty-six children from 23 families took part. Seventeen children had an MPS condition [MPS III (Sanfilippo) n = 15; MPS I (Hurler) n = 1; MPS IVA (Morquio); n = 1]. Nine children had Batten disease. Prospective data relating to symptoms were collected over 8 weeks using a symptom diary, and qualitative retrospective interviews with families were conducted. Main outcome measures included frequency, severity rating and identification of most challenging symptoms to manage.

RESULTS

The most common and severe symptoms in MPS III were agitation, repetitive behaviours, hyperactivity and disturbed sleep, and in Batten disease were agitation, joint stiffness, secretions, and disturbed sleep. The data highlighted the high prevalence of behavioural symptoms. Distress caused to families by symptoms was not related simply to their occurrence, but to difficulty in management, likelihood of control and extent to which they signalled disease progression and decline.

CONCLUSION

In challenging contrast to the dominant biomedical framing of these rare conditions it was behavioural symptoms, rather than the physical ones, that families documented as most frequent, severe and challenging to manage. The diary developed for this study has potential use in aiding parents and clinicians to document and communicate concerns about symptoms.

Predicting death in children

Rarely do paediatric palliative medicine physicians have to break the news of a diagnosis of a life-limiting condition. It is much commoner for us to be faced with the question: "how long?". This cannot be answered with certainty, and yet a great deal may depend on it. While palliative care should ideally be available from diagnosis, the need for "active" practical palliative care intervention will fluctuate during the course of a child's illness, often over months or years, sometimes decades. Typically, there will be several periods during which death seems likely before the final terminal episode, particularly among children with non-malignant life-limiting condition. Optimal management of all episodes depends on anticipating the child's needs, which in turn depends on recognising that such an episode has begun. Providing adequate palliative care critically depends on making a diagnosis of dying. In this article, we will consider why it is important to make a diagnosis of dying, briefly review some of the helpful tools available, and examine some of the evidence from published literature in children and adults.

Transgenic peas (Pisum sativum) expressing polygalacturonase inhibiting protein from raspberry (Rubus idaeus) and stilbene synthase from grape (Vitis vinifera)

The pea (Pisum sativum L.) varieties Baroness (United Kingdome) and Baccara (France) were transformed via Agrobacterium tumefaciens-mediated gene transfer with pGPTV binary vectors containing the bar gene in combination with two different antifungal genes coding for polygalacturonase-inhibiting protein (PGIP) from raspberry (Rubus idaeus L.) driven by a double 35S promoter, or the stilbene synthase (Vst1) from grape (Vitis vinifera L.) driven by its own elicitor-inducible promoter. Transgenic lines were established and transgenes combined via conventional crossing. Resveratrol, produced by Vst1 transgenic plants, was detected using HPLC and the PGIP expression was determined in functional inhibition assays against fungal polygalacturonases. Stable inheritance of the antifungal genes in the transgenic plants was demonstrated.

In vitro tolerance to Botrytis cinerea of grapevine 41B rootstock in transgenic plants expressing the stilbene synthase Vst1 gene under the control of a pathogen-inducible PR 10 promoter

Resveratrol is a major phytoalexin in grapevine but its synthesis in response to phytopathogen attack decreases with grape berry ripening. A chimeric gene combining an alfalfa PR 10 promoter and Vst1 (Vitis stilbene synthase 1) gene was introduced into the genome of 41B rootstock. Transgenic plants were analysed for resveratrol production in leaves infected with Botrytis using an in vitro test. Among the 50 transgenic lines analysed, some exhibited a production lower than the non-transgenic control, but others accumulated resveratrol from 5-100-fold. Moreover, in the latter clones, symptoms were highly reduced in response to infection. These results were a good indication that the combination of a pathogen-inducible promoter and a defence gene may increase tolerance against fungi in grapevine. The efficacy of this approach should be further tested by experiments conducted in the vineyard.

Recombinant proteins from transgenic plants

Transgenic plants can express a wide variety of foreign genes and offer the opportunity of large-scale protein production in agricultural systems. The recombinant protein can serve both ex situ and in situ purposes. Due to significant progress in plant molecular biology, many different plant species can now be transformed and are even capable of producing very complex proteins such as antibodies or vaccines. Furthermore, recombinant proteins can mediate resistance against microbial pathogens, such as fungi or viruses, or protect transgenic plants from insect pests.

An ozone-responsive region of the grapevine resveratrol synthase promoter differs from the basal pathogen-responsive sequence

Stilbene synthase (STS) is an enzyme involved in the biosynthesis of stilbenes, which are synthesized in various plants in response to pathogen attack, UV irradiation or exposure to ozone. We describe analysis of an ozone inducible STS transcript and its corresponding promoter (Vst1), combined with the beta-glucuronidase (GUS) reporter gene. A single ozone pulse (0.1 microliter/l, 10 h) resulted in 11-fold GUS expression. Histochemical localization of GUS activity revealed small spots distributed over the whole leaf. Cross-sections of leaf tissue showed that the Vst1 promoter was induced in palisade and spongy parenchyma cells and to a lesser extent in epidermal cells. Deletions at the 5' end showed that a partial promoter sequence between position -430 and -280 constituted the ozone-responsive region, whereas for effective pathogen-inducibility sequences from -280 to -140 have been shown to be necessary.

Transgenic tobacco plants expressing the Arabidopsis thaliana nitrilase II enzyme

Nitrilase (E.C. 3.5.5.1) cloned from Arabidopsis thaliana converts indole-3-acetonitrile to the plant growth hormone, indole-3-acetic acid in vitro. To probe the capacity of ths enzyme under physiological conditions in vivo, the cDNA PM255, encoding nitrilase II, was stably integrated into the genome of Nicotiana tabacum by direct protoplast transformation under the control of the CaMV-35S promotor. The regenerated plants appeared phenotypically normal. Nitrilase II was expressed, based on the occurrence of its mRNA and polypeptide. The enzyme was catalytically active, when extracted from leaf tissue of transgenic plants (specific activity: 25 fkat mg(-1) protein with indole-3-acetonitrile as substrate). This level of activity was lower than that found in A. thaliana, and this was deemed essential for the in vivo analysis. Leaf tissue from the transgenic plants converted 1-[13C]-indole-3-acetonitrile to 1-[13C]-indole-3-acetic acid in vivo as determined by HPLC/GC-MS analysis. Untransformed tobacco was unable to catalyze this reaction. When transgenic seeds were grown on medium in the absence of indole-3-acetonitrile, germination and seedling growth appeared normal. In the presence of micromolar levels of exogenous indole-3-acetonitrile, a strong auxin-overproducing phenotype developed resulting in increased lateral root formation (at 10 microM indole-3-acetonitrile). Collectively, these data prove the ability of nitrilase II to convert low micromolar levels of indole-3-acetonitrile to indole-3-acetic acid in vivo, even when expressed at subphysiological levels thereby conferring a high-auxin phenotype upon transgenic plants. Thus, the Al thaliana nitrilase activity, which exceeds that of the transgenic plants, would be sufficient to meet the requirements for auxin biosynthesis in vivo.

Disease resistance results from foreign phytoalexin expression in a novel plant

Although phytoalexins have long been inferred to be important in the defence of plants against fungal infection, there are few reports showing that they provide resistance to infection. Several plants, including grapevine, synthesize the stilbene-type phytoalexin resveratrol when attacked by pathogens. Stilbenes with fungicidal potential are formed in several unrelated plant species, such as peanut (Arachis hypogaea), grapevine (Vitis vinifera) and pine (Pinus sylvestris). Stilbene biosynthesis only specifically requires the presence of stilbene synthase. Furthermore, the precursor molecules for the formation of hydroxy-stilbenes are malonyl-CoA and p-coumaroyl-CoA, both present in plants. To investigate the potential of stilbene biosynthetic genes in a strategy of engineering pathogen resistance, we isolated stilbene synthase genes from grapevine, where they are expressed at a high level, and transferred them into tobacco. We report here that regenerated tobacco plants containing these genes are more resistant to infection by Botrytis cinerea. This is, to our knowledge, the first report of increased disease resistance in transgenic plants based on an additional foreign phytoalexin.

Transgenic Brassica napus plants obtained by cocultivation of protoplasts with Agrobacterium tumefaciens

Hypocotyl protoplasts of German winter oilseed, rape (Brassica napus) lines of double-low quality were transformed using Agrobacterium tumefaciens harbouring pGV 3850∶1103 neo (dimer) containing chimaeric kanamycin resistance reporter genes. Transformed protoplasts were regenerated to fertile and phenotypically normal plants. Transformation was confirmed by kanamycin resistance, nopaline production, neomycinphosphotransferase II activity, and Southern blot hybridization. Seed progeny from self-pollinated transformants expressed the introduced kanamycin resistance as a Mendelian trait.

Expression of a stilbene synthase gene in Nicotiana tabacum results in synthesis of the phytoalexin resveratrol

A gene from groundnut (Arachis hypogaea) coding for stilbene synthase was transferred together with a chimaeric kanamycin resistance gene. It was found to be rapidly expressed after induction with UV light and elicitor in tobacco cells (Nicotiana tabacum). Comparative studies of stilbene synthase mRNA synthesis in groundnut and transgenic tobacco suspension cultures revealed the same kinetics of gene expression. Stilbene synthase specific mRNA was detectable 30 minutes after elicitor induction and 10 minutes after UV irradiation. The maximum of mRNA accumulation was between 2 and 8 hours post induction. 24 hours after induction stilbene synthase mRNA accumulation ceased. Furthermore, in transgenic tobacco plants, the gene was found to be inducible in sterile roots, stems and leaves. Stilbene synthase was demonstrated in crude protein extracts from transgenic tobacco cell cultures using specific antibodies. Resveratrol, the product of stilbene synthase, was identified by HPLC and antisera raised against resveratrol.

Segregation of Triazine-Resistant Chloroplasts after Introduction into Winter Type Oilseed Rape (Brassica napus L.) by Protoplast Fusion

Triazine-resistant chloroplasts of the Canadian spring oilseed rape variety OAC Triton were transferred into four German winter oilseed rape lines and two cultivars of double-low quality by means of protoplast fusion. X-irradiation has been used to reduce the amount of nuclear D N A of the spring type cultivar and to promote cybrid formation. RFLP-analysis showed that some regenerants and their progeny carried both types of chloroplasts. In some instances regenerants and progeny containing mixtures of both chloroplasts not kept under selective conditions lost their triazine-resistant chloroplasts completely during further plant growth. Preliminary results of greenhouse and field experiments indicate that volunteer plants can be eliminated by application of 150-300 g/ha metribuzin (SencorR, Bayer AG) in a stand of triazine-resistant oilseed rape of double-low quality.

Morphine metabolism in children

1. The metabolism of morphine was studied in 12 children and nine premature neonates on a continuous infusion of morphine (10-360 micrograms kg-1 h-1). 2. The mean plasma clearance of morphine was significantly higher in children than neonates (25.7 and 4.7 ml min-1 kg-1, respectively) (P less than 0.01). 3. All the neonates and children had detectable concentrations of morphine-3-glucuronide (M3G) in plasma. All the children and five neonates had detectable concentrations of morphine-6-glucuronide (M6G) in plasma or urine. 4. The M3G/morphine ratios in plasma and urine, and M6G/morphine ratios in urine were significantly higher in children than neonates (P less than 0.01), suggesting that morphine glucuronidation capacity is enhanced after the neonatal period. 5. There was no difference in the M3G/M6G ratio in children and neonates, indicating a parallel development of both glucuronidation pathways.

Clinical benefits of early cold therapy in accident and emergency following ankle sprain

One hundred and forty-three patients presenting with ankle sprains within 24 h of injury were entered into a double blind study. Treatment consisted of a standardized regime of high dose non-steroidal anti-inflammatory medication and an elastic support for all patients, who were then randomly allocated to two groups. One group received immediate cold therapy, the other received simulated therapy. Assessments made at 7 days showed a trend in favour of the group receiving cold therapy, although this did not reach significance. It is concluded that cold therapy together with compression may have a beneficial effect but that a single application in the accident and emergency department is not justified when a background therapy of non-steroidal anti-inflammatory medication is given.

Benefits of early anti-inflammatory medication following acute ankle injury

A total of 122 patients presenting with acute ankle injuries within 6 h of injury were entered into a double-blind study. Treatment consisted of a standardized regimen of physiotherapy and elastic support for all patients, who were then randomized into two groups. One group received immediate ibuprofen (2400 mg/day) while the other group received placebo medication for 48 h, followed by ibuprofen (2400 mg/day) from the 3rd day onwards, i.e. delayed antiinflammatory treatment. Assessments were made by means of a daily diary and also by clinical and radiological examination. The immediate treatment group demonstrated more rapid recovery by day 7 in terms of regression of swelling (P less than 0.01) and clinician's impression of severity (P less than 0.05). This group also tended to consider their ankle more able to bear weight at this stage (P = 0.05). In comparison with an earlier study, in which the only active treatment was an elastic support, a greater percentage of patients recovered earlier in the present study. The incidence of side-effects was low. Immediate high-dose ibuprofen is therefore recommended as treatment for moderate to severe acute ankle injuries.

Effects of Cold and Compression on Edema

In brief: A 40-minute cooling period was used to treat artificially induced acute inflammatory reactions in human tissue. Results showed no significant change in the volume of the inflammatory reaction at one hour, though a transient attenuation during the first 15 minutes was detected. The addition of mild pressure (10 mm Hg) to mild cooling (range, 15° to 25° C) produced a highly significant reduction in swelling from 15 minutes onward, This effect was sustained as long as swelling was detectable. Pressure alone (20 mm Hg) had a nonsignificant effect. The authors compare two cooling devices, an inflatable cooling cuff and an evaporative bandage, which were both found to be effective. The authors suggest that these devices could be used more routinely in emergency medicine.

Transfer and segregation of triazine tolerant chloroplasts in Brassica napus L

Hypocotyl protoplasts of 45 different genotypes of German winter oilseed rape Brassica napus L. (double zero quality: high in yield, seeds low in erucic acid and glucosinolate content) were regenerated to plants. Triazine/triazinone (tri)-tolerant chloroplasts of the Canadian spring oilseed rape variety OAC Triton were introduced into some winter oilseed rapes by means of protoplast fusion. X-ray irradiation was used to limit the transfer of nuclear DNA of Triton protoplasts and to promote the selective transfer of tri-tolerant chloroplasts. Regenerated "cybrid" plants survived a treatment rate of 1000 g/ha metribuzin. The presence and segregation of the tri-tolerant chloroplasts in winter oilseed rape plants, regenerated from fusion products and their progeny, was investigated by restriction fragment length polymorphism (RFLP). Our results indicate that chloroplast segregation was not completed in plants regnerated from fusion products derived from X-irradiated OAC Triton mesophyll protoplasts and German winter oilseed rape hypocotyl protoplasts. In regenerants and their progeny both chloroplast types can still be present. Chloroplasts derived from wintertype protoplasts can outcompete tritolerant chloroplasts during plant development. In some instances, even progeny plants not kept under selective conditions (metribuzin) lost tri-tolerant chloroplasts. A homogenous population of tri-tolerant chloroplasts was necessary to obtain stable tri-tolerant winter oilseed rape plants.

Comparison of 1,2-dihydropyrido[3,4-b]pyrazines (1-deaza-7,8-dihydropteridines) with several other inhibitors of mitosis

Several properties of four 1-deaza-7,8-dihydropteridines were compared with those of each other and with those of colchicine, nocodazole, podophyllotoxin, and vincristine. Compound NSC 370147 was more active than the other compounds of this type with respect to inhibition of proliferation of cultured L1210 cells and to increase of the mitotic index. On an equimolar basis it was more active than two of the 1-deaza-7,8-dihydropteridines, colchicine, and nocodazole and was comparable to podophyllotoxin and vincristine in inhibiting the polymerization of partially purified pig brain tubulin. All four of the 1-deaza-7,8-dihydropteridines caused decreases in the extent of binding of [3H]colchicine to partially purified tubulin and enhanced the binding of [3H]vincristine to the tubulin. Emphasis in further testing was placed upon NSC 370147, because it is easier to synthesize and is more stable than some of the other compounds of this type and because its greater solubility in water facilitates its formulation for therapeutic administration. Compound NSC 370147 inhibited competitively the binding of [3H]colchicine to purified tubulin and enhanced slightly the binding of [3H]vincristine to tubulin. It was also synergistic with vincristine in killing cultured L1210 cells and in increasing the life-spans of mice bearing P388 leukemia. It is suggested that it would be worthwhile to evaluate combinations of NSC 370147 and vincristine in tests with other experimental neoplasms.

Studies of the structure and functional organization of foreign DNA integrated into the genome of Nicotiana tabacum

In transgenic plants obtained either by Agrobacterium tumefaciens-mediated transformation or by direct DNA transfer, the structure of integrated chimeric donor DNA remains stable during vegetative proliferation, during sexual transmission, and under various selection conditions. We correlate the level of expression of the introduced gene in independent transformants and their offspring with the particular arrangement and modification of their integrated DNAs. Genetic analysis of transgenic plants shows that the chimeric gene is transmitted in a Mendelian fashion to the F1 and F2 progeny as a single dominant trait. Deviations from the expected segregation pattern are discussed with respect to different levels of gene activity. We compare the gene activity in heterozygotes versus homozygotes, and show variation in activity between plants regenerated independently from the same transformed callus. Cotransformation studies with two physically unlinked and partly homologous plasmids carrying two different marker genes indicate that they are physically linked after integration into the host genome.

Fate of selectable marker DNA integrated into the genome of Nicotiana tabacum

To compare the effects of different transformation methods on the integration behavior and structural stability of integrated foreign genes in plant cells, tobacco protoplasts were transformed with Escherichia coli plasmid pLGV2103neo DNA using the Ca phosphate DNA coprecipitation technique. Parallel transformations were done by cocultivation with Agrobacterium tumefaciens harboring the Ti plasmid derivatives pGV3850::2103neo or pGV3850::1103neo. A comparison of the fine structure of the integrated donor DNA obtained by direct gene transfer and by cocultivation indicates that the donor DNA in cells transformed by the former technique undergoes structural changes and concatemerizations, while the DNA integrated by the latter procedure is often unaltered. The cotransformed nopaline synthase gene, which is present in the donor Ti plasmid DNA, was inactivated in two out of nine cases. Once integrated, the arrays of selectable marker DNA appear to be structurally stable under different cell culture and selection conditions, as well as after genetic transmission.

Construction of a heat-inducible gene for plants. Demonstration of heat-inducible activity of the Drosophila hsp70 promoter in plants

A chimeric gene containing the neomycin phosphotransferase II coding region under the control of the hsp70 promoter from Drosophila was integrated and found to be expressed, in a heat-regulated fashion, in tobacco tissue.

Isolation of a dual plant promoter fragment from the Ti plasmid of Agrobacterium tumefaciens

The two most abundant transcripts derived from TR-DNA within plant cells transformed by an octopine strain of Agrobacterium tumefaciens arise from divergent transcription, both originating within an 500 bp section of the T-DNA. Using a combination of subcloning and exonuclease digestion, a 479-bp DNA fragment, directly flanked by the initiation codons for the two adjacent open reading frames, was isolated. The resulting DNA fragment was fused, in both orientations, to the neomycin phosphotransferase (NPT II) gene of the transposon Tn5 prior to introduction into Nicotiana tabacum cells via the Ti plasmid. The intergenic fragment was found to initiate expression of the NPT II gene in either orientation as assayed by kanamycin resistance of the transformed plant tissue as well as by enzymatic assay of the NPT II gene product. The plasmids described here are potential selection-expression vectors for plant systems.

Fusion of Agrobacterium and E. coli spheroplasts with Nicotiana tabacum protoplasts - Direct gene transfer from microorganism to higher plant

Spheroplasts of Agrobacterium tumefaciens strains and E. coli were fused with protoplasts of Nicotiana tabacum. Fusion products were cultured in the presence of antibiotics to eliminate remaining bacterial spheroplasts. On hormone free medium, tobacco protoplasts treated with wild type Agrobacterium-strains formed colonies with an average frequency of 10(-4). Opine synthesis was detected in the tissues. Some calli derived from protoplasts treated with A. tumefaciens C58C1pRi15834 formed typical hairy roots. Kanamycin resistant calli were obtained after fusion with A. tumefaciens containing pLGVTi23 neo (frequency=10(-3)). Fusion of E. coli spheroplasts containing a virulent pTiB6S3::RP4 co-integrate with tobacco protoplasts yielded two hormone independent growing calli producing octopine out of 10(5) microcalli.

Metabolic effects of oral contraceptives containing 30 micrograms and 50 micrograms of oestrogen

In Study A, biochemical data from 17 women who were not taking oral contraceptives were compared with those from women taking preparations which contained either 30 microgram of ethinyl oestradiol and 150 microgram of D-norgestrel (18 women) or 50 microgram of ethinyl oestradiol and 250 microgram of D-norgestrel (nine women). In Study B, biochemical data were collected from eight women before and during the first three or four months therapy with preparations containing 30 microgram of ethinyl oestradiol and 150 microgram of D-norgestrel. The two oral contraceptive dosage forms studied produced qualitatively and quantitatively similar metabolic changes. Both caused an increase in serum concentration of triglycerides (30% to 33%), beta-lipoproteins (27% to 29%) and ceruloplasmin (75% to 90%), and a decrease in serum levels of antithrombin III (22% to 29%) and ascorbic acid (30% to 42%). Serum cholesterol and phospholipid concentrations were unchanged. However, the proportion of serum cholesterol carried by alpha-lipoproteins (high density lipoproteins) decreased, while that carried by beta-lipoproteins (low density and very low density lipoproteins) increased. The former change is in the same direction, but much smaller than that observed in coronary heart disease.