A new cluster of three tRNA genes in Pseudomonas aeruginosa.
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Base Sequence↗
Biomedical subjects
G Ball
Publications and source records attributed to G Ball.
Protein secretion in Pseudomonas aeruginosa: characterization of seven xcp genes and processing of secretory apparatus components by prepilin peptidase.
The xcp genes are required for the secretion of most extracellular proteins by Pseudomonas aeruginosa. The products of these genes are essential for the transport of exoproteins across the outer membrane after they have reached the periplasm via a signal sequence-dependent pathway. To date, analysis of three xcp genes has suggested the conservation of this secretion pathway in many Gram-negative bacteria. Furthermore, the xcpA gene was shown to be identical to pilD, which encodes a peptidase involved in the processing of fimbrial (pili) subunits, suggesting a connection between pili biogenesis and protein secretion. Here the nucleotide sequences of seven other xcp genes, designated xcpR to -X, are presented. The N-termini of four of the encoded Xcp proteins display similarity to the N-termini of type IV pili, suggesting that XcpA is involved in the processing of these Xcp proteins. This could indeed be demonstrated in vivo. Furthermore, two other proteins, XcpR and XcpS, show similarity to the PilB and PilC proteins required for fimbriae assembly. Since XcpR and PilB display a canonical nucleotide-binding site, ATP hydrolysis may provide energy for both systems.
Amino Acid Sequence↗
Cognitive-behavioral therapy for panic: an open study.
This paper reports results of an open prospective study of 26 patients who met DSM-III criteria for panic disorder or agoraphobia with panic attacks. Cognitive-behavioral treatment alone produced clinically and statistically significant improvement in panic symptoms, including both full-blown and limited symptom episodes. In addition, the treatment produced improvement in associated symptoms of phobic avoidance and generalized anxiety. This work provides further preliminary indication of the usefulness of cognitive-behavioral strategies as an alternative to medication in symptom-oriented treatments.
Adult↗
Protein secretion in Pseudomonas aeruginosa: the xcpA gene encodes an integral inner membrane protein homologous to Klebsiella pneumoniae secretion function protein PulO.
xcp mutations have pleiotropic effects on the secretion of proteins in Pseudomonas aeruginosa PAO. The nucleotide sequence of a 1.2-kb DNA fragment that complements the xcp-1 mutation has been determined. Sequence analysis shows the xcpA gene product to be a 31.8-kDa polypeptide, with a highly hydrophobic character. This is consistent with a localization in the cytoplasmic membrane in P. aeruginosa, determined after specific expression of the xcpA gene under control of the T7 phi 10 promoter. A very strong homology was found between XcpA and PulO, a membrane protein required for pullulanase secretion in Klebsiella pneumoniae. This suggests the existence of a signal sequence-dependent secretion process common to these two unrelated gram-negative bacteria.
Amino Acid Sequence↗
Vulnerability to sodium lactate in panic disorder patients given cognitive-behavioral therapy.
Six patients with panic disorder who had panicked during sodium lactate infusion were given cognitive-behavioral treatment for 12-24 weeks. After treatment they underwent another lactate infusion, and four patients were rates as having no panic, suggesting that reduced vulnerability to lactate accompanies remission of panic. Controlled trials of cognitive-behavioral therapy and use of lactate infusion as a measure of remission are recommended.
Adolescent↗
Protein secretion in gram-negative bacteria: transport across the outer membrane involves common mechanisms in different bacteria.
The xcp genes are required for protein secretion by Pseudomonas aeruginosa. They are involved in the second step of the process, i.e. the translocation across the outer membrane, after the exoproteins have reached the periplasm in a signal peptide dependent fashion. The nucleotide sequence of a 2.5 kb DNA fragment containing xcp genes showed at least two complete open reading frames, potentially encoding proteins with molecular weights of 41 and 19 kd. Products with these apparent molecular weights were identified after expression of the DNA fragment in vitro and in vivo. Subcloning and complementation experiments showed that both proteins are required for secretion. The two products are located in the inner membrane and share highly significant homologies with the PulL and PulM proteins which are required for the specific secretion of pullulanase in Klebsiella pneumoniae. These homologies reveal the existence of a common mechanism for protein secretion in Pseudomonas aeruginosa and Klebsiella pneumoniae.
Amino Acid Sequence↗
Recovery from milk allergy in early childhood: antibody studies.
We assessed the relationships of clinical symptoms and serum antibody levels during follow-up of 47 patients, aged 3 to 66 months, who were shown by formal milk challenge to have cow milk allergy. Three groups of patients were identified. Group 1 patients (n = 15) were sensitized to IgE and responded rapidly to small volumes of milk with urticaria, an exacerbation of eczema, wheeze, or vomiting. In the second group (n = 24), symptoms of milk enteropathy (vomiting and diarrhea) developed between 1 and 20 hours after milk ingestion. In the group 3 patients (n = 8), coughing, diarrhea, eczematoid rashes, or a combination of these developed more than 20 hours after normal volumes of milk were given. Serum levels of IgG, IgA, IgM, and IgE and of milk-specific anti-cow milk antibodies of these isotypes were measured initially and then at a median follow-up time of 16 months (range 6 to 39 months). In this investigation, changes in these immunologic measures during the study period were related to whether or not clinical tolerance to cow milk was achieved. At follow-up, six patients from group 1, ten from group 2, and two from group 3 were milk tolerant. No consistent change in any of the immunologic measurements was associated with remission of the disease. These findings raise the question of whether acquisition of clinical tolerance to cow milk in cow milk allergy can be attributed solely to immunologic events.
Animals↗
Systemic lymphoproliferative responses to rotavirus.
In comparison with healthy adults, elderly patients and patients who had received renal transplants had significantly lower lymphoproliferative responses to rotavirus (P = 0.04, P = 0.002, respectively) and phytohaemagglutinin (P = 0.001). However, following acute rotavirus infection, elderly persons mounted good lymphoproliferative and specific antibody responses to rotavirus. No lymphoproliferative response or specific antibody to rotavirus was detected in a child with cartilage hair hypoplasia. In cord blood samples, specific antibodies were detected in the absence of a lymphoproliferative response to rotavirus. Increases in lymphoproliferative responses as well as specific antibodies were not detected in immune adult recipients of a human rotavirus vaccine (RIT 4375), but a recipient of a bovine vaccine (RIT 4237) had an increase in lymphoproliferative response to rotavirus between 13 and 28 days postvaccination. Stimulation indices for both rotavirus and phytohaemagglutinin within the vaccine groups were comparable to the healthy laboratory personnel group.
Adult↗
Clinical manifestations of cows' milk allergy in childhood. I. Associations with in-vitro cellular immune responses.
In this study 51 children who presented with symptoms of cows' milk allergy (CMA) were categorized clinically by their response to cows' milk challenge. Forty-two patients had unequivocal evidence of CMA and nine were milk tolerant. Of the patients with CMA two groups were identified. The first, made up of 32 patients, had immediate-type hypersensitivity reactions to milk associated with both positive skin-prick test (SPT) and RAST. The second group of 10 late reacting patients developed symptoms of CMA over several hours or days; significant increases in irritability, frequency of bowel actions, and rhinitis following milk ingestion were noted in this group. Leucocyte inhibition factor (LIF) produced in response to alpha-lactalbumin, beta-lactoglobulin and alpha-casein was assessed in the immediate and late reacting CMA patients as well as in the milk-tolerant group. There was no difference in LIF production between the milk-tolerant group and those with immediate reactions. However, these two groups produced less LIF than the late reacting patients for alpha-lactalbumin (P = 0.02), alpha-casein (P = 0.03) and beta-lactoglobulin (P = 0.05). A clinical dairy score card was found to be a useful instrument to assess the response of non-immediate reactions to milk ingestion.
Animals↗
Homology between endoglucanase Z of Erwinia chrysanthemi and endoglucanases of Bacillus subtilis and alkalophilic Bacillus.
Nucleotide sequencing of the celZ gene encoding the extracellular endoglucanase Z of Erwinia chrysanthemi indicated the presence of an open reading frame encoding 428 amino acids. The mature protein appeared to be extended by a signal peptide of 43 amino acids; this sequence is unusually long and positively charged (+5). It was shown to function as a signal peptide by fusing it to a truncated phoA gene encoding Escherichia coli alkaline phosphatase. Comparison of the encoded sequence with those of the endoglucanases of Bacillus subtilis and alkalophilic Bacillus revealed the existence of a region of extensive homology occurring in all three proteins at about the same distance from the NH2-terminal end. These regions may be involved in substrate binding and/or catalytic sites.
Alkaline Phosphatase↗
Post-natal depression and other myths.
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Depressive Disorder↗
Behavior therapy for panic disorder.
Eleven patients who met DSM-III criteria for panic disorder were treated with behavior therapy techniques. Seven patients had mixed phobic avoidance and none were agoraphobic; three had no phobic symptoms. Mean duration of symptoms was 3.4 years. Treatment lasted a mean of 14 weeks and consisted of 1) education about physiology and management of panic symptoms; 2) relaxation, abdominal breathing, and cognitive anxiety management skills; and 3) imaginal and in vivo exposure. Upon termination of treatment, 10 of 11 patients were panic-free and six of seven mixed phobics showed complete remission or significant improvement of phobias. Follow-up data revealed excellent stability of remission. Clinical implications for the use of behavior therapy for panic disorder and directions for future research are discussed.
Adult↗
The electromicrophysiology of delta waves induced by systemic atropine.
Delta waves in the EEG can be induced by the intravenous administration of atropine. In cats we have investigated with several computer averaging programs the relationship of extracellular unit discharge to the EEG on the surface and within the cortex. We have also studied the laminar profiles and the vertical current density profiles of these slow waves. Our results indicate that surface-positive delta waves are related to events associated with excitation of cortical neurons, while surface-negative delta waves are related to a decreased probability of unit firing suggesting the possibility of inhibition. Laminar analysis of atropine-induced slow waves indicated that these were probably generated by pyramidal cells in a similar way to delta waves induced by brain lesions. These results suggest that a disturbance in cholinergic input to the cortex might be responsible for delta waves in the EEG.
Animals↗
Cytogenetics of malignant epithelial cells and lymphoblastoid cell lines from nasopharyngeal carcinoma.
The malignant epithelial cells of nasopharyngeal carcinoma (NPC) and cells of lines derived form the lymphoid cells which infiltrate this tumour have been investigated cytogenetically. Chromosome spreads of lymphoblastoid cells of lines established from 7 different NPC biopsy specimens were examined after banding staining. Banding was also applied to the epithelial tumour cells of 5 further biopsy specimens freed from non-malignant infiltrating cells by passage through nude mice; epithelial cell spreads were obtained by in vivo splindle arrest. Five of the lymphoblastoid lines were found to be diploid, and 2 tetraploid; the karyotypes were essentially normal. The squamous epithelial nature of the cells in the nude-mouse-grown NPC tumours was established by light and electronmicroscopy, and 3 tumours were found to be near-triploid, and 2 near-diploid. The cells of the near-triploid tumours contained grossly abnormal chromosomes but those of the near-diploid tumours showed only relatively minor changes. Although abnormalities were observed which were specific for cells from each individual tumour, no discernible change was common to cells from all the tumours.
Adult↗
Cytogenetic observations on the malignant epithelial cells and infiltrating lymphocytes of nasopharyngeal carcinoma.
Because of the presence of a No 14 chromosome marker abnormality in EB virus-carrying cells from African Burkitt's lymphoma (BL) but not from other origins, and the association of EB virus with nasopharyngeal carcinoma (NPC) as well as BL, both the malignant epithelial cells and the non-malignant lymphoid cells of NPC have been investigated cytogenetically. Chromosome spreads from seven NPC-derived lymphoblastoid lines were examined after banding; five lines were diploid and two were tetraploid. No consistent no. 14 chromosome abnormalities were found. Apart from a secondary constriction near the centromere of both no. 1 chromosomes in all cells of one diploid line, no consistent significant abnormalities were seen. Five NPC tumours, freed of infiltrating lymphoid cells by passage through nude mice, were similarly examined after spindle arrest in vivo. Two tumours were near-diploid, and three were hypo-tetraploid. Near-diploid cells had only minor chromosomal changes, but the hypotetraploid spreads from all tumours showed gross changes of uncertain origin, including frequent, major translocations. No. 14 chromosome marker changes were not seen, and there was no other consistent pattern of abnormality in tumour cells.
Animals↗
Brain lesions that produce delta waves in the EEG.
Localized delta activity appears in cortex overlying a circumscribed white matter lesion. Less commonly, localized delta activity may result from a localized thalamic lesion. Unilateral diffuse delta activity appears on the side of thalamic or hypothalamic lesions. Bilateral delta activity results from bilateral lesions of the midbrain tegmentum. Localized lesions of the cerebral cortex, unilateral mesencephalic tegmental lesions, and vasogenic edema of the cerebral white matter do not produce delta activity. Marked edema of a cerebral hemisphere when no surgical decompression is provided may produce unilateral delta activity by pressure on or displacement of the brain stem or diencephalon.
Animals↗
Pilot experiments with EB virus in owl monkeys (Aotus trivirgatus). III. Serological and biochemical findings in an animal with reticuloproliferative disease.
Nucleic acid hybridization with EB virus complementary RNA has demonstrated unequivocally that EB virus DNA is present in the cells of a continuous lymphoblastoid line established in culture from a pathological lymph node of an owl monkey with reticuloproliferative disease after inoculation with EB virus. There were 48 to 49 EB virus genome equivalents per cell. In addition, serological studies showed that the diseased owl monkey developed specific antibodies to EB virus capsid antigens. The antibodies were first detected by indirect immunofluorescence in serum sampled 13 weeks after inoculation, and were not found in sera from other animals without the disease. None of the monkeys developed heterophile antibodies. The significance of the biochemical and serological findings is discussed in relation to the nature of the reticuloproliferative disease and the possibility of tumour-induction by EB virus.
Animals↗