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M Kristjansson

Publications and source records attributed to M Kristjansson.

7 recordsLinked to original sources

Genotype-phenotype interactions in Wilson's disease: insight from an Icelandic mutation.

Wilson's disease, an autosomal recessive disorder of copper transport, usually presents with symptoms from the liver or central nervous system. Rarely, the initial manifestation is fulminant hepatic failure. The abnormal gene (ATP7B) is located on chromosome 13q and encodes a copper-transporting ATPase. A large number of mutations have been reported. We describe a previously healthy 16-year-old girl who presented with fulminant hepatic failure. The girl died within 24 h of admission to a hospital from refractory shock. Autopsy revealed cirrhosis and widespread necrosis of the liver. The copper content of the liver was markedly increased (975 micrograms/g dry weight), strongly suggesting a diagnosis of Wilson's disease. Genetic studies revealed that the girl was homozygous for the mutation 2007 del7, which is the mutation found in all Wilson's disease patients previously identified in Iceland. This is the first known case of fulminant hepatic failure due to Wilson's disease in Iceland. Despite the same mutation, the clinical picture is vastly different from other Icelandic patients with Wilson's disease, who all presented with relatively late-onset neurological disease. This suggests that factors other than the specific mutation have significant impact on the phenotype of the disease.

Adolescent↗

Pneumonia caused by penicillin-non-susceptible and penicillin-susceptible pneumococci in adults: a case-control study.

The objective of this study was to investigate the observation that patients with pneumonia due to penicillin-non-susceptible pneumococci (PNSP) in many instances present with milder disease than patients with pneumonia caused by penicillin-susceptible pneumococci (PSP) and to compare the cost of treatment. The clinical data, APACHE II score and laboratory features of hospitalized adults with pneumonia caused by PNSP or PSP were compared, along with antibiotic and hospital costs. Each patient with PNSP pneumonia (n = 36) was matched to a control with PSP pneumonia of the same age and gender. There was no difference in smoking history, but PNSP pneumonia patients had received prior antibiotics more frequently (p < 0.007). The mean APACHE II score was not different, but when broken down into acute vs. chronic scores those with PSP pneumonia had a significantly higher acute score (p = 0.005). Bacteraemia was present in 9 of 31 (29%) patients with PSP compared to 2 of 25 (8%) with the PNSP pneumonia (p = 0.09). The majority of isolates in the PNSP group were of serotype 6B (minimum inhibitory concentration range 0.125-2.0 mg/l), whereas serotypes 7, 9, 14, 18 and 19 were noted among the 9 PSP isolates. Compared with the control group, patients with the PNSP strains had a significantly longer hospital stay, 26.8 vs. 11.5 days (p = 0.001) and higher average antibiotic cost, $736 vs. $213 (p < 0.0001). In conclusion, pneumonia in adults caused by PNSP is associated with a milder clinical presentation than infection caused by PSP, suggesting either that resistance carries a price or that the serotypes of PNSP are less virulent. Pneumonia due to PNSP resulted in increased cost because of prolonged hospitalization and the use of more expensive antibiotics.

APACHE↗

Persistent and relapsing infections associated with small-colony variants of Staphylococcus aureus.

Small-colony variants (SCVs) of Staphylococcus aureus were cultured from five patients with persistent and relapsing infections. All five SCV strains were nonhemolytic and nonpigmented and grew very slowly on routine culture media in an ambient atmosphere. In several instances, these phenotypic characteristics led to the initial misidentification of the organisms in the clinical microbiology laboratory. All four strains available for further analysis were shown to be auxotrophs that reverted to normal growth and morphology in the presence of menadione, hemin, and/or a CO2 supplement. Similarly, these isolates were resistant to aminoglycosides under routine conditions but susceptible in the presence of the metabolic supplements. For two patients, the large and small colony forms isolated concurrently were indistinguishable when analyzed by pulsed field gel electrophoresis and thus represented phenotypic variants within individual clones. We propose a model relating the phenotypic characteristics of S. aureus SCVs with the clinical pattern of persistent and relapsing infection.

Aged↗

Molecular confirmation of bacillus Calmette-Guérin as the cause of pulmonary infection following urinary tract instillation.

Instillation into the urinary tract of the bacillus Calmette-Guérin (BCG), a strain of Mycobacterium bovis, is associated only rarely with severe side effects. We report here two cases of culture-proven pulmonary infection due to therapy with BCG. The first patient, who was seropositive for the human immunodeficiency virus, developed bilateral interstitial pneumonitis after instillation of BCG into the bladder. The second patient developed a right-lower-lobe infiltrate and empyema after instillation of BCG into the right renal pelvis. The clinical isolates from these two patients and from a third patient with a psoas abscess following intravesical instillation were analyzed with use of pulsed field gel electrophoresis (PFGE) to resolve chromosomal restriction fragment polymorphisms. The clinical isolates were confirmed to be BCG by comparison with known vaccine strains that differed from M. bovis isolates. We conclude that the potential for subsequent dissemination be considered prior to the intravesical administration of BCG. Analysis with PFGE may be useful for identifying species of the Mycobacterium tuberculosis complex.

Administration, Intravesical↗

Mycobacterium haemophilum infection in immunocompromised patients: case report and review of the literature.

Mycobacterium haemophilum, previously characterized as an unusual pathogen, is found primarily in immunocompromised hosts. This organism has stringent growth characteristics and may not be isolated using routine techniques. M. haemophilum infects the skin and underlying tissues, a circumstance which reflects the organism's propensity for growth in a cooler environment. Infections have been reported in renal transplant recipients, patients with Hodgkin's disease, and, more recently, patients with AIDS. The organism has also been isolated from children with cervical lymphadenitis in the absence of apparent immunodeficiency. Response to therapy has not been uniform, and in some instances improvement in immune status has been associated with regression of lesions. With proliferation of transplantation surgery, chemotherapy, and AIDS, the number of infections due to M. haemophilum is likely to increase.

Adult↗