Studies on the large subunit rRNA genes and their flanking regions of Leuconostocs

The products that are processed in aqueous form, such as Aqoat MF (suspension), Aquateric (pseudolatex), HP 55 (ammonia-based solution), and Kollicoat MAE 30 D (latex), were compared (in the form of spray dispersions, isolated films prepared from the dispersions, and caffeine-film-coated tablets with 5.5, 8.0, and 11.0 mg film/cm2) with one another and with ethanolic HP 55 S solution. The addition of pigments to all of the liquid preparations, with the exception of the ammoniacal solution of HP 55, led to a slight increase in pH. In each case, the viscosity of both solutions was well above that of the other formulations. The minimum film-forming temperature was decidedly reduced by the addition of pigment. Kollicoat MAE was the undissolved film-former that had the smallest particle size and particle size distribution. The next smallest were those of Aqoat MF. The latex and the suspension were the only products that were sensitive to shear and heat. The isolated films did not display any tack. The strongest films and the films most impermeable to water vapor were obtained from solutions, and this can be ascribed to the fine distribution of the film-former. None of the isolated films showed signs of dissolving at pH 4.5. At pH 5.5, only the HP 55 was dissolved. This was because HP 55 was processed in ammonia-based solution; as a result of which, films that were not very resistant to gastric juice were obtained. The other formulations did not dissolve until the pH reached 6.0. As the pH rose, the rate of dissolution increased for all of the films. The permeability to protons was similar to that of caffeine-film-coated tablets to gastric juice. The resistance increased in the following sequence: HP 55 (ammonia-based) < Aquateric < Aqoat MF < HP 55 S (organic) and Kollicoat MAE. As a result of the temperature treatment and the rate of spraying, the production time on a 5-kg scale was twice as long for 5.5 mg Aqoat MF/cm2 as it was for Kollicoat MAE. This amount of film sufficed for Kollicoat MAE and HP 55 S solution to achieve adequate resistance to gastric juice. Aqoat MF did not attain the same resistance until a thickness of 11 mg film/cm2 was reached. Film tablets with Aquateric and ammonia-based HP 55 solution absorbed more than 20% of gastric juice at this film thickness.     

Absence of linkage of obesity and energy metabolism to markers flanking homologues of rodent obesity genes in Pima Indians

The homologues of single genes that cause obesity in rodents are suggested as candidate genes for modulation of body composition in humans. Among these genes are the four mouse mutations-diabetes (db), obesity (ob), tubby (tub), and yellow agouti (Ay). Variation in the human counterparts to these genes (OB, DB, TUB, and ASP, respectively) may contribute to human obesity, which is thought to have a substantial genetic component. To initially assess the potential contribution of these genes to human obesity, we examined polymorphic DNA markers that, by virtue of syntenic relationships to appropriate regions of the mouse genome, should be closely linked to the human counterparts of these genes. Using combined data from 716 Pima Indians comprising 217 nuclear families, we have tested a number of polymorphic microsatellite markers (three at DB, two at OB, five at TUB, and three at ASP) for sib-pair linkage to BMI, percentage body fat, resting metabolic rate, 24-h energy expenditure, and 24-h respiratory quotient. No significant linkages were found in an analysis of all sibships or in an analysis restricted to discordant sib pairs.     

A genomic map of infectious laryngotracheitis virus and the sequence and organization of genes present in the unique short and flanking regions

The involvement of the intermediate area and B?tzinger complex (BOT) of the rostral ventral respiratory group (r-VRG) in laryngeal control and generation of the expiration reflex were studied in anaesthetized non-paralyzed cats Focal cooling (to 20 degrees C) of the nucleus paraambigualis (NPA) caused changes in the frequency and timing of breathing with the concomitant rise in laryngeal resistance. Cooling of the nucleus ambiguus resulted in a consistent drop in laryngeal resistance. Alterations in timing and intensity of breathing but no changes in laryngeal patency were found during cooling of the BOT. The expiration reflex was inhibited by cooling of either the NPA or BOT. The role of these medullary regions in the control of laryngeal patency and central integration of the expiration reflex is discussed.     

Purification and characterization of an agglutinin in the red alga Agardhiella tenera

The red alga, Agardhiella tenera was found to contain a glycoprotein which agglutinates mouse leukemia cells, L5178Y but not L1210. It also agglutinates guinea pig and rabbit erythrocytes, and has weak activity against human A, B and O, mouse, horse and sheep erythrocytes and hamster and mouse lymphocytes. The agglutination was not inhibited by simple sugars. The major active component was purified and determined to be a beta-structure protein containing 2.7% glucose as sugar moiety. The molecular weight was estimated to be 12,000 by gel filtration and 13,000 by polyacrylamide gel electrophoresis, in the presence of sodium dodecylsulfate. Its isoelectric point was 6.1, and it contained high amounts of glycine, serine and threonine, but no half cystine or histidine. It had no subunit structure, and the C- and N-terminal amino acids were threonine and arginine, respectively.     

Sequence and transcriptional analysis of groES and groEL genes from the thermophilic bacterium Clostridium thermocellum

Ca ++/cAMP response element binding protein (CREB), phosphoCREB, and c-Fos-like (c-FL) immunoreactivity (IR) were examined in the nucleus of the solitary tract (NTS) and parabrachial nucleus (PBN) after peripheral cholecystokinin (CCK). c-FLIR was observed only after CCK, but CCK did not alter high basal levels of CREB-IR and phosphoCREB-IR. PhosphoCREB may be necessary but is not sufficient to induce c-Fos after CCK injection.     

The sex-inducing pheromone and wounding trigger the same set of genes in the multicellular green alga Volvox

The sex-inducing pheromone of the multicellular green alga Volvox carteri is a glycoprotein that triggers development of males and females at a concentration <10(-16) M. By differential screening of a cDNA library, two novel genes were identified that are transcribed under the control of this pheromone. Unexpectedly, one gene product was characterized as a lysozyme/chitinase, and the other gene product was shown to encode a polypeptide with a striking modular composition. This polypeptide has a cysteine protease domain separated by an extensin-like module from three repeats of a chitin binding domain. In higher plants, similar protein families are known to play an important role in defense against fungi. Indeed, we found that the same set of genes triggered by the sexual pheromone was also inducible in V. carteri by wounding.     

Isolation and structure/activity features of halomon-related antitumor monoterpenes from the red alga Portieria hornemannii

Ten halogenated monoterpenes (2-6 and 8-12) related to the novel antitumor compound halomon (1) or to the carbocyclic analog 7 have been isolated from different geographic collections of the red alga, Portieria hornemannii. Structures were assigned to the basis of spectral analyses (primarily NMR and MS). The absolute configuration of isohalomon (2) was further established by X-ray crystallography. The compounds were comparatively evaluated alongside 1 and 7 in the U.S. National Cancer Institute's in vitro human tumor cell line screening panel. The results provide some interesting initial insights into the structure/activity relationships in this series.     

Cloning and characterization of the nuclear gene and cDNAs for triosephosphate isomerase of the marine red alga Gracilaria verrucosa

cDNAs and an intronless single-copy nuclear gene (TPI1) encoding triosephosphate isomerase have been cloned and sequenced from the marine red alga Gracilaria verrucosa. The predicted amino-acid sequence of TPI1 is readily alignable with those of other known TPIs; 26 of 27 active-site residues and 19 of 26 intersubunit-contact residues are identical between TPIs of G. verrucosa and/or animals and green plants. A partial cDNA sequence of a second TPI gene (TPI2), presumably encoding plastid-localized TPI, was recovered by PCR and demonstrated by phylogenetic analysis to be red algal; no TP12 cDNA or genomic clones could be recovered. Genomic Southern analysis demonstrated that at least two TPI-like genes are present in the nuclear DNA of G. verrucosa.     

Identification and structural characterization of two genes encoding glutamate transporter homologues differently expressed in the nervous system of Drosophila melanogaster

The aim of the present investigation was to study the effect of neurotoxic ibotenic acid lesion of the retrochiasmatic area on the daily profile of pineal N-acetylserotonin and melatonin synthesis and on the pineal metabolic reactivity to nocturnal short-term retinal photostimulation. Groups of rats were killed 6 h after lights off either in the dark of immediately after being photostimulated for 1 or 15 min. Additionally, groups of rats were sacrificed at six different time points throughout the 24-hour light-dark cycle. The results suggested the presence of two functionally distinct territories in the retrochiasmatic area. The basal retrochiasmatic area, an area situated immediately ventral to the third ventricle, behind the suprachiasmatic nuclei and in front of the arcuate nucleus, is implicated in the nocturnal inhibitory process induced by short-term retinal photostimulation. The lateral retrochiasmatic area, which is situated immediately lateral to the anterior periventricular nucleus, below the anterior hypothalamic nucleus and in front of the ventromedial hypothalamic nucleus, is importantly involved in the control of the peak amplitude of the daily production of N-acetylserotonin and melatonin by the pineal gland.     

Voltage-gated potassium channel genes are clustered in paralogous regions of the mouse genome

Cloning of the Drosophila Shaker gene established that a neurological phenotype including locomotor dysfunction can be caused by a mutation in a voltage-gated potassium (K) channel gene. Shaker sequences have been used to isolate a large family of related K channel genes from both flies and mammals. Toward elucidating the evolutionary relationship between loci and the potential causal connection that K channels may have to mammalian genetic disorders, we report here the genetic mapping of 12-16 different murine, voltage-gated K channel genes. We find that multiple genes, in some cases from distantly related K channel subfamilies, occur in clusters in the mouse genome. These mapping results suggest that the K channel gene subfamilies arose through ancient localized gene duplication events, followed by chromosomal duplications and rearrangements as well as further gene duplication. We also note that several neurologic disorders of both mouse and human are associated with the chromosomal regions containing K channel genes.     

Sequence analysis of a 33.2 kb segment from the left arm of yeast chromosome XV reveals eight known genes and ten new open reading frames including homologues of ABC transporters, inositol phosphatases and human expressed sequence tags

This retrospective study was undertaken to determine the revision rate for dynamic sphincter pharyngoplasty (DSP) at the University of Michigan Medical Center to analyze the determinants contributing to the need for revision pharyngoplasties, and ultimately to improve primary pharyngoplasty to avoid the need for revision. The records of 30 children with repaired palatal clefts who presented with velopharyngeal insufficiency and hypernasal speech, and who underwent DSP from January 1988 through July 1994 were reviewed. Clinical follow-up ranged from 6 to 48 months (mean, 20.2 months). Seven of the original 30 patients (23%) had persistent, moderate-to-severe hypernasality that required reoperation, while 1 patient (3%) demonstrated hyponasality requiring revision. Seven of 8 patients who underwent revision pharyngoplasty had acceptable speech after revision. Dehiscences, low-lying pharyngoplasty flaps, and end-to-end suturing of the flaps were the main determinants resulting in the need for revision. In our study, female gender and older age was associated with a higher success of primary operation.     

Organization and expression of basement membrane collagen IV genes and their roles in human disorders

PURPOSE: The prevalence of reflux in the deep and superficial venous systems in the Edinburgh population and the relationship between patterns of reflux and the presence of venous disease on clinical examination were studied. METHODS: A cross-sectional survey was done on men and women ranging in age from 18 to 64 years, randomly selected from 12 general practices. The presence of varicose veins and chronic venous insufficiency was noted on clinical examination, as was the duration of venous reflux by means of duplex scanning in 8 vein segments on each leg. Results were compared using cut-off points for reflux duration (RD) of 0.5 seconds or more (RD >/= 0.5) and more than 1.0 second (RD > 1.0) to define reflux. RESULTS: There were 1566 study participants, 867 women and 699 men. The prevalence of reflux was similar in the right and left legs. The proportion of participants with reflux was highest in the lower thigh long saphenous vein (LSV) segment (18.6% in the right leg and 17.5% in the left leg for RD >/= 0.5), followed by the above knee popliteal segments (12.3% in the right leg and 11.0% in the left leg for RD >/= 0.5), the below knee popliteal (11.3% in the right leg and 9.5% in the left leg for RD >/= 0.5), upper LSV (10.0% in the right leg and 10.8% in the left leg for RD >/= 0.5) segments, the common femoral vein segments (7.8% in the right leg and 8.0% in the left leg for RD >/= 0.5), the lower superficial femoral vein (SFV) segments (6.6% in the right leg and 6.4% in the left leg for RD >/= 0.5), and the upper SFV (5.2% in the right leg and 4.7% in the left leg for RD >/= 0.5) and short saphenous vein (SSV) (4.6% in the right leg and 5.6% in the left leg for an RD >/= 0.5) segments. In the superficial vein segments, there was little difference in the occurrence of reflux whether RD >/= 0.5 or RD > 1.0 was used; but in the different deep vein segments, the prevalence of reflux was 2 to 4 times greater for RD >/= 0.5 rather than RD > 1.0. Men had a higher prevalence of reflux in the deep vein segments than women, reaching statistical significance (P /= 0.5. In general, the prevalence of reflux increased with age. Those with "venous disease" had a significantly higher prevalence of reflux in all vein segments than those with "no disease" (P 相似文献   

The potato mitochondrial initiator methionine tRNA gene and its flanking regions: an illustration of the diversity of mitochondrial genome rearrangements among plant species

The initiator methionine transfer RNA (tRNA(fMet)) gene was identified on a 347 bp Eco RI-Hind III DNA fragment of the potato mitochondrial (mt) genome. The sequence of this gene shows 1 to 7 nucleotide differences with the other plant mt tRNAs(fMet) or tRNA(fMet) genes studied so far. Whereas the tRNA(fMet) gene is present as a single copy in the potato mt genome, a tRNA 'pseudogene' corresponding to 60% of a complete tRNA (from the 5' end to the variable region) and located at 105 nucleotides upstream of the tRNA(fMet) gene on the opposite strand was shown to be repeated at least three times. Furthermore, the physical environment of the tRNA(fMet) gene in the mt genome is very different among plants, which suggests that the tRNA(fMet) gene region has often been implicated in recombination events of plant mt genomes leading to important rearrangements in gene order.     

Partial cloning and differential expression of ryanodine receptor/calcium-release channel genes in human tissues including the hippocampus and cerebellum

Previous data indicated a tissue-specific regulation of mitochondrial pyruvate dehydrogenase (PDH) complex, especially in the brain and testis. The lack of biochemical data on the rat testis PDH limits comparative analysis between testis and liver enzymes. Therefore, we have isolated a cDNA clone encoding rat testis PDH E1 alpha isoform, determined its nucleotide sequence, studied the tissue-specific expression, and characterized the recombinant protein produced in bacteria, compared to the liver counterpart. Our cDNA clone (2.2 kb) contained the identical open reading frame (from nt 974 to 2149) with that previously reported (Cullingford et al., 1993 Biochim Biophys Acta 1216:149-153) but contained a long 5' untranslated region, which has little identity to the other clone. Northern blot confirmed testis-specific expression of this isoform. Genomic DNA analyses by PCR amplification suggested this clone is a gene product distinct from its X-linked somatic counterpart. Our biochemical and kinetic analyses revealed that the purified recombinant rat testis PDH E1 (containing both E1 alpha and E1 beta subunits) was enzymatically active and phosphorylated in vitro by purified PDH-kinase p48 or p45, similar to the recombinant human liver enzyme. Our current data thus indicate that the differential regulation of testis PDH observed in the animal model may result from differential modulation of PDH-kinase or -phosphatase in this tissue rather than the presence of functionally different PDH E1 subunit.