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Biomedical subjects

S Heber

Publications and source records attributed to S Heber.

10 recordsLinked to original sources
PubMed2000

Mapping analysis of the Xylella fastidiosa genome.

A cosmid library was made of the 2.7 Mb genome of the Gram-negative plant pathogenic bacterium Xylella fastidiosa and analysed by hybridisation mapping. Clones taken from the library as well as genomic restriction fragments of rarely cutting enzymes were used as probes. The latter served as a backbone for ordering the initial map contigs and thus facilitated gap closure. Also, the co-linearity of the cosmid map, and thus the eventual sequence, could be confirmed by this process. A subset of the eventual clone coverage was distributed to the Brazilian X.FASTIDIOSA: sequencing network. Data from this effort confirmed more quantitatively initial results from the hybridisation mapping that the redundancy of clone coverage ranged between 0 and 45-fold across the genome, while the average was 15-fold by experimental design. Reasons for this not unexpected fluctuation and the actual gaps are being discussed, as is the use of this effect for functional studies.

Brazil↗
PubMed1998

Optimization and automation of fluorescence-based DNA hybridization for high-throughput clone mapping.

Large-scale hybridization-based genome mapping projects, such as the production of sequence-ready physical clone maps, call for robust and cheap DNA labeling techniques that are amenable to automation. We routinely use a high-throughput protocol based on fluorescence detection. DNA probes are labeled via polymerase chain reaction (PCR) amplification with primers that are digoxigenin-modified at their 5' ends. Alternatively, digoxigenin-labeled dUTP is incorporated in a random hexamer priming reaction. Hybridization takes place in small volumes by sandwiching the probe between filters and plastic sheets. A fluorescence signal is produced by the activity of alkaline phosphatase attached to an anti-digoxigenin antibody upon the addition of AttoPhos substrate. Signals are directly detected with a charge-coupled device (CCD) camera and scored by an image data analysis system. DNA filters can be reused at least 40 times without loss of data quality. Significant advantages compared to radioactive techniques are the reduced health risk, enabling highly parallel processing; the production of spot signals uniform in size and intensity, which is essential for efficient image analysis; and a cost reduction of about 70%.

Alkaline Phosphatase↗
PubMed1991

Genetic regulation of cardiolipin synthase in Escherichia coli.

Recombinant DNA and genetic techniques were used to construct Escherichia coli strains SOH92 [phi(cls-lacZ+)] and SOH93 [phi(cls-'lacZ)hyb]. beta-Galactosidase (116 kDa) synthesized by strain SOH92 was primarily present in the particulate fraction. Strain SOH92 produced about 20-fold more beta-galactosidase activity than strain SOH93. Expression of clsphilacZ in both SOH92 and SOH93 was influenced by the terminal electron acceptor (increasing in the order oxygen, nitrate, fumarate) when the cells were cultured in minimal medium with glycerol as the sole carbon source. As strains SOH92 and SOH93 progressed from early to late log growth phase under aerobic conditions in LB broth, clsphilacZ expression increased about 2.5-fold. Fusion strains containing a pss-1 allele had an increased cardiolipin (CL) level, but no corresponding increase in clsphilacZ expression was observed. A cls::Tn10dTet null mutation was introduced into SOH92 and SOH93. The strains produced less CL, but no corresponding changes in clsphilacZ expression were observed. A high copy number plasmid bearing the cls gene had no effect on clsphilacZ expression. Taken together, these results indicate that cls is not subject to autogenous regulation.

Blotting, Southern↗
PubMed1989

Differentiating multiple personality disorder and complex partial seizures.

A number of reports have suggested that some cases of multiple personality disorder might be due to temporal lobe epileptic discharges. We have administered a structured interview, the Dissociative Disorders Interview Schedule, to 20 subjects with multiple personality disorder, 20 with complex partial seizures, and 28 neurologic controls. Subjects also completed the Dissociative Experiences Scale. Results show that multiple personality can be differentiated from complex partial seizures on a large number of items. The seizure patients did not differ from controls. The data indicate that the phenomenologies of these two disorders are distinct, and, therefore, there is little reason to assume a common etiology.

Adult↗
PubMed1989

Somatic symptoms in multiple personality disorder.

A structured interview, the Dissociative Disorders Interview Schedule, was administered to 20 patients with multiple personality disorder, 20 with panic disorder, 20 with eating disorders, and 20 with schizophrenia. The frequencies of somatization disorder and of individual somatic symptoms in the four groups were compared. The multiple-personality patients reported more somatic symptoms than the other groups. Of the 20 multiple-personality patients, seven met the criteria for somatization disorder. The average number of somatic symptoms per multiple-personality patient was 13.5.

Adult↗
PubMed1989

Differences between multiple personality disorder and other diagnostic groups on structured interview.

The Dissociative Disorders Interview Schedule was administered to 20 subjects with multiple personality disorder, 20 with schizophrenia, 20 with panic disorder, and 20 with eating disorders. The findings showed that multiple personality can be differentiated from the other groups on variables such as history of physical abuse, sexual abuse, substance abuse, sleepwalking, childhood imaginary playmates, secondary features of multiple personality and extrasensory and supernatural experiences. Those with multiple personality also differ from the other groups on DSM-III criteria for multiple personality, psychogenic amnesia, and psychogenic fugue. The groups did not differ on the number of subjects who had had a major depressive episode.

Adult↗