Identification of new mitochondrial genome organizations in wheat plants regenerated from somatic tissue cultures

Plants have been regenerated from short-and long-term in vitro somatic tissue cultures made from immature embryos of the hexaploid wheat cultivar "Chinese Spring". The mitochondrial genome organization of each regenerated plantlet was studied, after one selfing, by probing Sal I-restricted total DNA with cloned Sal I fragments of wheat mitochondrial DNA derived from a segment of the genome, which displays marked structural changes in response to in vitro culture. Short-term in vitro cultures give rise to regenerated plants whose mitochondrial genome organization is either close to that of the parental cultivar or to that of embryogenic callus cultures, except for a single plant which has an organization resembling that of short-term non-embryogenic cultures. In contrast, all but one of the plants regenerated from long-term cultures exhibited a mitochondrial genome organization similar to that of long-term nonembryogenic cultures. In addition, extra labelled bands were detected in some of the regenerated plants with two of the probes used. These results emphasize the importance of the duration of the in vitro step preceding the regeneration process: the longer it is, the higher the probability is of obtaining mitochondrial DNA variability in regenerated plants. Furthermore, since increasing the duration of the in vitro stetp results in the production of regenerated plants with a mitochondrial genome organization resembling that of non-embryogenic tissue cultures, the question is thus raised as to whether regeneration from long-term cultures is suitable for use in plant breeding.

[A new in vitro test of endothelial viability. Vital staining using Janus green with spectrophotometric analysis of the color extract]

A new in vitro technique has been developed to measure by simple photometry the amount of Janus Green extracted with absolute alcohol from isolated corneas after vital staining. The amount of stain corresponds to the percentage of damaged endothelial cells and is a reliable parameter of endothelial viability. More rapid and easier to perform than the usual cell counting of devitalized cells this technique may be used to study the endothelial damage induced e.g. by experimental surgery, intraocular solutions, IOL material, cornea storage solutions.

Variations in long-term wheat somatic tissue culture

Morphological and chromosomal changes were induced among plants regenerated from wheat somatic embryogenic tissues that retain regenerative potential for a long time. An effect of in vitro culture on mitochondrial DNA was also ascertained since variations in mitochrondrial DNA were observed in embryogenic and nonembryogenic genotypes. These variations were detected on restriction patterns. The possible significance of the mtDNA variations in affecting plant fertility and regeneration ability is discussed.

[One year after Chernobyl. Cesium-137 levels in premature, newborn and nursing infants and in younger and older children of Bonn and environs]

From May to August 1987, 137Cs activity was measured in a total-body counter (4 pi counter) in 33 premature and mature newborns (group I), 40 infants and young children up to 2 4/12 years of age (group II), and 15 children between 3 and 6 8/12 years (group III), all from Bonn or its environs. The mean of measurements in group II, at 3.7 Bq/kg body-weight, was lower than that of group I (5.8 Bq) and III (9.4 Bq). Mean radiation exposure, calculated from these data, was 1.7 mrem/a for group I, 1.1 mrem/a for group II, and 2.8 mrem/a for group III. A comparison with present Cs values in adults and measurements made at the end of the 1950's and beginning of 60's showed good agreement. There were no significant differences, as regards Cs activity, between newborns or infants who had been formula-fed or breast-fed. The measured radiation exposure of the three groups is about 1% of natural radiation exposure. Thus, present-day results indicate that there will be no damage to health outside the natural scatter.

Evaluation of daunomycin toxicity on lens epithelium in vitro

Posterior capsule opacification is the major complication of extracapsular cataract extraction (ECCE). Lens epithelial cells derived from the periphery of the lens are thought to migrate posteriorly and contribute significantly to the postoperative proliferations at the posterior pole. We have evaluated the effects of the antiproliferative drug daunomycin on cultured porcine lens epithelial cell viability and proliferation. We observed that the mitotic activity of the cells is suppressed by a single short time treatment with daunomycin at a concentration as low as 2.5 mg/l. Long term effects on the reproductive capacity of the lens epithelial cells may not be as pronounced as the inhibition of other cells examined before e.g. retinal pigment epithelium and fibroblasts. Our results indicate that daunomycin may be useful for the pharmacologic prevention of postoperative proliferations in patients treated by ECCE.

Pyrroloquinoline quinone: a new redox cofactor in eukaryotic enzymes

During the past decade pyrroloquinoline quinone has been shown to be a new redox cofactor for a range of bacterial alcohol dehydrogenases. Recent studies suggest that this cofactor may also be covalently bound to the active site of the eukaryotic copper amine oxidases. In this mini-review we present the evidence in support of pyrroloquinoline quinone as a novel eukaryotic cofactor. As a result of mechanistic advances during the last three years, together with a re-examination of previously existing data, a working model for the role of pyrroloquinoline quinone in enzyme-catalyzed amine oxidation reactions can be proposed.

Endothelial alterations in AIDS with cytomegalovirus infection

We report on a patient in whom a cytomegalovirus infection occurred in connection with AIDS. Together with the alterations of the fundus typical for cytomegalovirus retinitis, reticular deposits were observed on the corneal endothelium. Specular microscopy showed occasional endothelial cells with edema, as well as small, dark, round, mobile structures (probably lymphocytes) and large, bright, spindle-shaped, immobile structures (probably macrophages) located behind the endothelium. Despite treatment with corticosteroids and acyclovir, an increase in the extent of the findings was observed. The deposits are interpreted as a reaction of the endothelium to the cytomegalovirus infection.

Aromatase activity in monolayer cell cultures of human endometrium

Monolayer cell cultures of proliferative human endometrial stromal cells were incubated with 100 nCi 3H-androstenedione or 100 nCi 3H-testosterone for 15 hours. After termination of the incubations 16% of the recovered radioactivity was identified as estrone by thin layer chromatography and subsequent recrystallization. 3H-testosterone was almost quantitatively converted to 3H-androstenedione. 3H-dihydrotestosterone remained unmetabolized. These findings indicate a highly active 17 beta-ol-dehydrogenase and a high aromatizing capacity of human endometrial cells.

Gametoclonal variation detected in the nuclear ribosomal DNA from doubled haploid lines of a spring wheat (Triticum aestivum L., cv. 'César')

The organization of the nuclear ribosomal DNA from a parental line of wheat (Triticum aestivum L., cv. 'César') and its anther-derived first cycle and second cycle doubled haploid lines has been analyzed by DNA-DNA molecular hybridization. Restricted DNA has been probed by three subclones of wheat nuclear ribosomal DNA covering the entire repeat unit. No significant difference was detected in the extent of methylation of ribosomal DNA of the doubled haploid lines with respect to the parental line. On the other hand, a variation has been found in the organization of the nontranscribed spacer region of ribosomal DNA of the first cycle doubled haploid line. This variation remains stable after a second cycle of in vitro androgenesis. However, one out of five second cycle doubled haploid lines so far tested showed an additional hybridization band present in the parental line but lacking in the first cycle doubled haploid line.

Reductive trapping of substrate to bovine plasma amine oxidase

Plasma amine oxidases catalyze the oxidative deamination of amines to aldehydes, followed by a 2e- reduction of O2 to H2O2. Pyrroloquinoline quinone (PQQ), previously believed to be restricted to prokaryotes, has recently been proposed to be the cofactor undergoing reduction in the first half-reaction of bovine plasma amine oxidase (Ameyama, M., Hayashi, U., Matsushita, K., Shinagawa, E., and Adachi, O. (1984) Agric. Biol. Chem. 48, 561-565; Lobenstein-Verbeek, C. L., Jongejan, J. A., Frank, J., and Duine, J. A. (1984) FEBS Lett. 170, 305-309). This result is unexpected, since model studies with PQQ implicate Schiff's base formation between a reactive carbonyl and substrates, whereas experiments with bovine plasma amine oxidase have failed to provide evidence for a carbonyl cofactor. We have, therefore, re-examined putative adducts between substrate and enzyme-bound cofactor, employing a combination of [14C]benzylamine and [3H]NaCNBH3. The use of the relatively weak reductant, NaCNBH3, affords Schiff's base specificity and permits the study of enzyme below pH 7.0. As we show, enzyme can only be inactivated by NaCNBH3 in the presence of substrate, leading to the incorporation of 1 mol of [14C]benzylamine/mol of enzyme subunit at complete inactivation. By contrast, we are unable to detect any labeling with [3H]NaCNBH3, analogous to an earlier study with [3H]NaCNBH4 (Suva, R. H., and Abeles, R. H. (1978) Biochemistry 17, 3538-3545). We conclude, first, that our inability to obtain adducts containing both carbon 14 and tritium rules out the reductive trapping either of amine substrate with pyridoxal phosphate or of aldehyde product with a lysyl side chain and, second, that the observed pattern of labeling is fully consistent with the presence of PQQ at the active site of bovine plasma amine oxidase.

Small tandemly repeated DNA sequences of higher plants likely originate from a tRNA gene ancestor

Several monomers (177 bp) of a tandemly arranged repetitive nuclear DNA sequence of Brassica oleracea have been cloned and sequenced. They share up to 95% homology between one another and up to 80% with other satellite DNA sequences of Cruciferae, suggesting a common ancestor. Both strands of these monomers show more than 50% homology with many tRNA genes; the best homologies have been obtained with Lys and His yeast mitochondrial tRNA genes (respectively 64% and 60%). These results suggest that small tandemly repeated DNA sequences of plants may have evolved from a tRNA gene ancestor. These tandem repeats have probably arisen via a process involving reverse transcription of polymerase III RNA intermediates, as is the case for interspersed DNA sequences of mammalians. A model is proposed to explain the formation of such small tandemly repeated DNA sequences.

[Trypan blue and alizarin red S sequential staining with subsequent fixation. A modified technic for the study of the corneal endothelium]

A sequential corneal endothelium staining technique with trypan blue (TB)--alizarin red S (ARS)--ethanol-trypan blue is described which can be performed in a few minutes. The first step permits the TB exclusion to be determined as a criterion of normal endothelial cell function. The two following steps permit intercellular staining by ARS and nuclear staining by TB. After each staining procedure, fixation can be performed by methanol or ethanol, both with full-thickness corneal preparations or endothelial flat mounts. In flat preparations, the focussing problems and optical artifacts of full-thickness mounts can be avoided. These modifications render simple sequential staining with subsequent fixation a complement and alternative to specular microscopy and to the customary complicated silver staining of corneal endothelium.

Gene conversion as a mechanism for divergence of a chloroplast tRNA gene inserted in the mitochondrial genome of Brassica oleracea

We have characterized a 1.7 kb sequence, containing a tRNA Leu2 gene shared by the ct and mt genomes of Brassica oleracea. The two sequences are completely homologous except in two short regions where two distinct gene conversion events have occurred between two sets of direct repeats leading to the insertion of 5 bp in the T loop of the mt copy of the ct gene. This is the first evidence that gene conversion represents the initial evolutionary step in inactivation of transferred ct genes in the mt genome. We also indicate that organelle DNA transfer by organelle fusion is an ongoing process which could be useful in genetic engineering.

Organelle genome stability in anther-derived doubled haploids of wheat (Triticum aestivum L., cv. 'Moisson')

Chloroplast and mitochondrial compartments of a parental line of wheat (Triticum aestivum L., cv. 'Moisson') and its anther-derived doubled haploid lines have been analyzed and compared on the basis of their DNA restriction patterns. The results obtained show that no noticeable difference can be detected between doubled haploid lines and parental line at the level of ctDNA and mtDNA organization. It may be concluded that in vitro culture by itself does not systematically generate a cytoplasmic variation in germ cells.

Follow-up study of 100 malignant pleural mesotheliomas

One hundred malignant pleural mesotheliomas have been treated in our hospital since 1955. Clinical and autopsy findings are analyzed and compared to X-ray changes. The most common symptoms were dyspnea (49%), pain (40%) and cough (36%). The main initial X-ray signs were pleural effusion (62%), pleural thickening (29%) and solitary nodules (6%). Prior to death a combination of effusion and pleural thickening was the usual finding. Histologically there were 49 biphasic, 32 mesenchymal and 18 epithelial malignant pleural mesotheliomas. At autopsy 82% of the cases had distant metastases, most of which had not been expected clinically. The median survival time was 7.3 months following the first clinical symptoms, and only 4 months after the first radiological signs.

Possible effect of the cell synchronization method on the pattern of 5-bromodeoxyuridine incorporation into early synthesized DNA

Synchronously and asynchronously growing chick embryo fibroblasts have been used to study the pattern of 5-bromodeoxyuridine (BrdU) incorporation into DNA. In the synchronous cell system, the density of unifilarly substituted DNA is about 0.010 g/ml higher during first half of S phase than during second half of S phase. The density of unifilarly substituted DNA isolated from asynchronously growing cells is similar to that of DNA synthesized during the second half of S phase of synchronously growing cells for a given concentration of analogue in culture medium. Reassociation kinetics experiments have shown the oversubstitution to occur at the level of early synthesized repeated and/or intermediate DNA sequences. It is then assumed that the oversubstitution is due to some metabolic changes caused by the synchronization procedure itself. As BrdU incorporation into early replicating DNA is known to induce alterations of the cell metabolism, the implication of this phenomenon is discussed at the level of the inhibition of transformation which takes place when chick embryo fibroblasts are infected with Rous sarcoma virus during G1 and subsequently treated with BrdU during early S phase.

Hand-over-mouth behavior management technique in a solo pedodontic practice: a study

The hand-over-the-mouth technique (HOM) was studied in a single-dentist pedodontic practice. The study included the frequency of its use relative to the patient's age, sex, previous dental experience and history of a significant medical experience. Observations were also made of the nature of subsequent appointments. HOM was used for almost 10 percent of the patients studied in less than 2 percent of the total number of dental appointments. It was used most often for three-year-old patients, especially female. In the majority of cases (89 percent), it was used on a single occasion and that incident was followed by appointments of a positive nature.

[Clinical specular microscopy. Technic, organization and simple calculator morphometry]

The use of specular microscopy (SM) as a routine clinical method for qualitative morphological and quantitative morphometric analysis of the corneal endothelium requires a standardized examination technique. Organizational and apparative means are necessary for the analysis, documentation and storage of the data. The results of the immediate analysis are documented on a result form. The morphological changes are classified in 4 different groups (endothelial, pre-endothelial, retro-endothelial, and non-endothelial changes). The morphometric analysis is performed immediately: the mean cell density (mcd) is estimated by comparing the endothelial mosaic in the camera viewfinder with 3 standardized specular micrographs with known cellular density. The good correlation between the results of estimation and definite counting allows this rapid method to be used as a simple clinical screening techniques. The definitive morphometric analysis is carried out directly from the photographic negative using the fixed frame principle. The mcd and mean cell area (mca), m +/- sd, are determined by a simple method which saves time and money, using a scientific pocket calculator programmed in Basic. A specially designed slide rule serves to define the frame. The calculator may also be used for statistical analyses. This is demonstrated in a group of 127 patients (aged 51-87) before IOL implantation. The mcd and mca of the examined population is 2249 +/- 290 cells/mm2 and 444 +/- 57 microns 2. There is no statistically significant difference in mcd between the right and left eye (t-test: p = 0.93). Although statistically mcd decreases significantly with advancing age (p = 0.05), there is a large range of results in this population.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging of cylinders excised from pulp tissues of the ;golden delicious' apple

Aging cylinders excised from ;Golden Delicious' apple (Pyrus malus L.) pulp, like the intact fruit, exhibit some characteristic phenomena such as rise in respiration (climacteric), ethylene synthesis, enzymic changes, and increase in ribosomes and mRNA. Aging of cylinders of pulp tissues may offer a useful physiological tool for the study of maturation and senescence.

Study of pp60v-src protein kinase activity in synchronized chicken embryo fibroblasts infected with Rous sarcoma virus

Chicken embryo fibroblast (CEF) cultures, synchronized by the addition of serum to stationary cells, were exposed to Schmidt-Ruppin strain of Rous Sarcoma Virus (SR-RSV) and the appearance of pp60v-src protein kinase activity was examined through the cell cycle. In cells infected either at the beginning or at the end of G1, the onset of pp60v-src protein kinase activity was coincidental, closely following mitosis, with a delay between the infection of cells with SR-RSV and the appearance of protein kinase activity of about 20 and 16 h, respectively. In cells infected during the S phase this delay was 16 h, as observed for late G1 cells. These experiments show that the activity of pp60v-src protein kinase, which cannot be detected before the first mitosis following infection does not depend on G1. The aphidicolin prevented protein kinase activity if added before or at the beginning of S phase, but not if added later, which is presumably related to the inhibition of S phase, required for provirus integration. The use of colcemid, which suppresses cell division, did not inhibit but delayed the appearance of protein kinase activity. These results show that the synthesis of an active oncogene product, such as pp60v-src protein kinase, depends on both S phase and mitosis.

Polyribosomes from aging apple and cherry fruit

The sequence of events which occurs during the ripening of the Passe-Crassane pear fruit have been previously studied. In this work, we have investigated the ripening of another climacteric fruit (Pyrus malus L. cv Golden Delicious) and of a nonclimacteric fruit (Prunus avium L. cv Bigarreau Napoléon). We show that both climacteric fruits exhibit the same preclimacteric sequence of events. Differences exist, however, between the Golden Delicious apple and the Passe-Crassane pear in that the protein synthesis capacity of the two fruits is not the same during the over-ripening period. On the other hand, a nonclimacteric fruit, the Bigarreau Napoléon cherry, does not show an increase in its protein synthesis capacity during the over-ripening period.

Incorporation of 5-bromodeoxyuridine in the total and ribosomal DNA of synchronously dividing chick embryo fibroblasts

The pattern of 5-bromodeoxyuridine incorporation into ribosomal DNA is quantitatively different from that for total DNA. It is concluded that 5-bromodeoxyuridine incorporation along the DNA chain is not a random process.

An atypical Aspergillus flavus from a case of bronchopulmonary aspergilloma. A contribution to the cultural and serological diagnosis of A. flavus infections

A slow-growing, non-pigmented hyphomycete was isolated from sputum and a fungus ball removed at autopsy from the lung. The patient, an alcoholic, also suffered from cirrhosis and primary carcinoma of the liver. The atypical and otherwise non-recognizable isolate showed a growth typical of Aspergillus flavus when cultured on sterilized peanuts. This observation indicates the diagnostic significance of such strains which have become atypical, as etiologic agents and sources of antigen. Serologically, the antigen of the atypical strain proved to be stronger than that of a typical A. flavus strain. In view of the simultaneous presence of the liver carcinoma and the absence of aflatoxin production by the atypical strain, the possible role of chronic colonization of the lung by A. flavus is discussed.

[Changes, during a synchronous cell cycle, of the level of incorporation of 5-bromodeoxyuridine into DNA of chick embryo fibroblasts]

The determination of the buoyant density of synchronously dividing Chick embryo fibroblast DNA, substituted at various times during the cell cycle by 5-bromodeoxyuridine (BrdU), has been carried out by means of analytical neutral CsCl banding. It has been shown that the buoyant density of BrdU-substituted DNA, duplicated during the first half of S phase, was 0.010 g/ml higher than that of BrdU-substituted DNA duplicated during the second half of S phase. That may reflect a preferential incorporation of the analogue at the beginning of S phase. This peculiar pattern of incorporation would be responsible for the observed inhibition of cell transformation occurring when fibroblasts, infected by Rous sarcoma virus, are grown in the presence of the analogue.

Polyribosomes from Pear Fruit: II. CHANGES OCCURRING IN PULP TISSUES DURING RIPENING AND SENESCENCE

Detailed analyses of polysome profiles from lyophilized pulp tissues of pear fruits (Pyrus communis L. cv. Passe-Crassane) at different stages of ripening and senescence, and estimates of the amount of polysomal-associated mRNA, lead to the conclusions that during senescence (ripening), the ripening and the over-ripening processes can clearly be separated and respectively linked to the first and the second increase in the large mRNA species. Ethylene synthesis which occurs at the beginning of a normal ripening at 15 degrees C after a cold storage or an ethephon treatment is related to an increase in mRNA and ribosomal material found only in pulp tissues. Finally, we suggest that in the pear fruit, the sequence of events which occurs during senescence (ripening) is initiated by two systems which regulate ethylene biogenesis, and that the first system is efficient only at low temperatures (from 0 to 4 degrees C).

Studies on the development of extra-endothelial and intra-endothelial pigment deposits by means of direct and indirect contact specular microscopy of the cornea

Retro-corneal pigmentation as a result of primary (degenerative) or secondary (inflammatory, traumatic) pigment dispersion represents one of the most frequent findings in specular microscopy. The analysis of the pigment distribution patterns of dense deposits like those in Krukenberg spindle (KS) permits the postulation of a hypothesis concerning the development of such typical corneal pigmentations and the pigmentation of the posterior surface of the cornea in general, such as diffuse pigment dispersion (Vogt 1930), which is seen frequently. In a particular case of double KS with extreme myopia and cataract, endothelial morphological findings were documented over a period of 1 year, both before and after cataract extraction. This was done by means of contact and non-contact specular microscopy in various spindle areas. The morpho-metric studies (cell density/mm2; cell perimeter; largest smallest and average cell diameter; specific surface; horizontal and vertical cell orientation) were carried out automatically using a computerised video image analyser. The changes in the area of densest pigmentation in the KS centre confirm the histologically proven capacity of pigment phagocytosis by human corneal endothelium. These findings indicate that in specular microscopy, both endothelial cellular surface modifications and intra-cellular changes are documentable. The extracellular pigment deposits can also be shown by means of 'indirect' specular microscopy, the optical principle of which is described.

[Indirect contact specular microscopy. A new technique for the in vivo examination of the posterior corneal surface (author's transl)]

A new application of contact specular microscopy (CSM) is presented. This technique allows, in addition to conventional CSM and by augmentation of the applanation pressure of the CSM dipping cone, to observe changes on the posterior corneal surface in a three-dimensional mode. This technique gives valuable information in cases of preendothelial, endothelial, and retroendothelial modifications, leading to prominent changes of the posterior corneal surface. Thus, it is a very suitable method to interpret in vivo morphological findings. A hypothesis of the mechanisms leading to the three-dimensional image is presented. Based on these optical considerations the term 'indirect CSM' is proposed in contrast to the conventional direct CSM.

Determination of the mineral content and the transparency of the root dentine of human teeth

One hundred and fifty-six teeth were extracted from corpses aged between 15 and 79 years. Of these, 101 teeth were selected for measurement of the mineral content of the root by photon beam absorption. Six or seven cross-sections were measured in each root, and the mean values calculated for the apical, medial, and coronal part within each decade. Further, 20 selected teeth were embedded in methacrylate and the length of the zone of transparency determined in longitudinal sections. There was no significant age dependency of the root's mineral content. There was no correlation between the extent of transparency and the mineral content.

Polyribosomes from Pear Fruit: Changes during Ripening and Senescence

Polysome profiles were examined from lyophilized peel tissue of ripening pear (Pyrus communis, L. var. Passe-Crassane). Messenger RNA chains bearing up to eight ribosomes (octamers) were resolved and exhibited the highest absorption peak when ribonuclease activity was eliminated during extraction. Neither normal ripening nor the increase of large polyribosomes that normally accompanies ripening and senescence of the fruit occurred when pretreatment at 0 C was omitted. Normal ripening and increase of large polyribosomes would, however, be initiated by an ethylene treatment. The size distribution of the polyribosomes remained essentially constant throughout a 4-month cold storage; there was, however, a large increase in ribosomes by the 12th week of storage.

The prognostic significance of first and second remission after first and second relapse radiotherapy in Hodgkin's disease

New aspects concerning the prognostic importance of remission following first treatment and second relapse treatment have resulted from a retrospective study of 175 patients who received primary treatment for Hodgkin's disease between 1964 and 1971. By means of renewed radiotherapy 27 out of 66 (=41%) patients were again brought to full remission with 10 of the 66 (=15%) patients reaching partial remission. The prognosis of the second full remission is equal to that of the first full remission, the prospect of cure being retained. The prognosis of relapse patients following renewed radiotherapy is dependent on: 1. the type of the previous remission, whether full or partial, 2. the localization of the recidive, 3. the primary stage and the presence (or absence) of signs of activity B, 4. the histology, and 5. the age of the patient.

[Treatment of bradycardia with an atropine ester]

In view of the unsatisfying drug treatment of bradycardias in most cases, clinical studies with new compounds seem to be urgent. A report is given on experiences with a derivative of atropine (gen. Ipratropiumpromid) in 34 cases suffering from various types of bradycardias. Comparing heart rate following intravenous injections of 0.5 to 1.0 mg, the new drug proved to be definitely more effective than atropine sulfate. Side effects were limited to diminution of salivary glands function.