Ulla Eriksson

Genome-wide DNA microarray analysis of Francisella tularensis strains demonstrates extensive genetic conservation within the species but identifies regions that are unique to the highly virulent F. tularensis subsp. tularensis

ABSTRACT Francisella tularensis is a potent pathogen and a possible bioterrorism agent. Little is known, however, to explain the molecular basis for its virulence and the distinct differences in virulence found between the four recognized subspecies, F. tularensis subsp. tularensis, F. tularensis subsp. mediasiatica, F. tularensis subsp. holarctica, and F. tularensis subsp. novicida. We developed a DNA microarray based on 1,832 clones from a shotgun library used for sequencing of the highly virulent strain F. tularensis subsp. tularensis Schu S4. This allowed a genome-wide analysis of 27 strains representing all four subspecies. Overall, the microarray analysis confirmed a limited genetic variation within the species F. tularensis, and when the strains were compared, at most 3.7% of the probes showed differential hybridization. Cluster analysis of the hybridization data revealed that the causative agents of type A and type B tularemia, i.e., F. tularensis subsp. tularensis and F. tularensis subsp. holarctica, respectively, formed distinct clusters. Despite marked differences in their virulence and geographical origin, a high degree of genomic similarity between strains of F. tularensis subsp. tularensis and F. tularensis subsp. mediasiatica was apparent. Strains from Japan clustered separately, as did strains of F. tularensis subsp. novicida. Eight regions of difference (RD) 0.6 to 11.5 kb in size, altogether comprising 21 open reading frames, were identified that distinguished strains of the moderately virulent subspecies F. tularensis subsp. holarctica and the highly virulent subspecies F. tularensis subsp. tularensis. One of these regions, RD1, allowed for the first time the development of an F. tularensis-specific PCR assay that discriminates each of the four subspecies.

Pain as a symptom in depressive disorders: I. Relationship to diagnostic subgroup and depressive symptomatology.

Abstract The incidence of pain as a symptom in depressive disorders has been studied in a series of 161 depressed patients admitted to the Department of Psychiatry, Umeå University. 57% of the patients reported pain as a symptom. Female patients reported pain significantly more often than male patients and the patients with pain were found to be significantly older than those without. Despite the fact that patients with neurotic reactive depressions were significantly younger than the patients in the other diagnostic subgroups, they reported pain significantly more often than patients with other depressive disorders. Patients with pain were found to have significantly more muscular tension and more autonomic disturbances while no significant differences were found in items measuring sadness or inhibition‐retardation.

Pain as a symptom in depressive disorders. II. Relationship to personality traits as assessed by means of KSP.

Abstract The series included 140 hospitalized patients with depressive disorders, who were rated by means of the Comprehensive Psychopathological Rating Scale (CPRS). Furthermore, a personality inventory, KSP, was completed when the patients had improved markedly. Forty‐six per cent of the patients were found to have pain as a symptom. The patients with pain were found to have more somatic anxiety, more muscular tension, more psychasthenia and more inhibition of aggression but no significant differences were found in guilt. Thus pain as a symptom in depressive disorders seems to be linked to muscular tension and the patients seem to have more introjected aggression while no evidence emerges indicating that pain could serve to relieve the feelings of guilt.

Pain as a symptom in depressive disorders and its relationship to platelet monoamine oxidase activity

144 depressed in-patients were rated by means of the Comprehensive Psychopathological Rating Scale (CPRS) and platelet monoamine oxidase (MAO) was determined. 49 per cent of the patients were found to have pain as a symptom, and 21 per cent were found to have more severe pain. The patients with more severe pain were found to have lower platelet MAO activity than the patients without pain or with slight pain. As platelet MAO activity may reflect the turn-over in the serotinergic systems in CNS it is hypothesized that patients with depressive disorders with pain as a symptom may have more pronounced disturbances in the serotinergic systems than patients without pain as a symptom.

Aspects of aggression in formerly depressed patients and in healthy controls.

SummaryThirty former inpatients (14 male and 16 female) who had suffered from a nonpsychotic depressive syndrome were investigated by means of a new personality inventory—the KSP—when they had recovered from the depressive disorder, and their results were contrasted to those obtained from 53 healthy controls (19 male, 34 female). Attention was focused on the subscales of the KSP which refer to aspects of aggression. Former patients scored significantly higher than controls in the variables ‘irritability,’ ‘suspicion,’ ‘guilt,’ and ‘inhibition of aggression.’ The findings suggest a particular personality makeup for at least one subgroup of depression-prone subjects and closely resemble classical concepts of hostility and depression.