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Biomedical subjects

M Lundholm

Publications and source records attributed to M Lundholm.

27 records · Page 2Linked to original sources

Humidifier fever and endotoxin exposure.

Three cases of humidifier fever were detected in an office environment. Flavobacteria were found in the contaminated water in a humidifier. After an experimental exposure, the three persons with previous symptoms suffered from fever and slight respiratory symptoms. A leucocytosis and an increase in the number of segmented white blood cells were found the day following the exposure. General immunoglobulins as well as antibodies to Flavobacterium and endotoxin were slightly elevated in the exposed group. The possibility that endotoxins may be the causative agent by means of an indirect complement activation is discussed.

Adult↗

Bacterial contamination of cotton and cotton dust and effects on the lung.

Bacterial contamination of various parts of the cotton plant and of cotton from different mills was investigated. The predominant bacterial species were Gram-negative rods mainly of the Enterobacter genus. When guinea pigs inhaled strains of these bacteria cultivated from cotton, a strong leucocyte mobilising capacity was found for Pseudomonas and Enterobacter but not for Agrobacterium or Bacillus species. The aetiology of the development of pulmonary symptoms after inhalation of bacteria-containing dusts and subsequent production of endotoxins is discussed.

Animals↗

Studies on humans exposed to airborne sewage sludge.

A clinical investigation was made among workers in a sewage treatment plant and age matched controls not exposed to sewage. Acute incidences of fever and eye symptoms were found in about 50% of the exposed population. Serum immunoglobulins, white blood cells and thrombocytes were elevated in the exposed group. A higher percentage of increased levels of C-reactive protein and fibrinogen degradation products was found in the exposed group. Although no definite cause-effect relationship can be established the responsible agent in the environment could well be endotoxins.

Air Pollution↗

Properties of some staphylococcus aureus strains associated with spontaneous l-phase transformation.

Spontaneous L-phase production was found in 7 of 14 investigated Staphylococcus aureus strains. A common characteristic of the strains producing L-phase variants spontaneously was their ability to develop L-colonies on a solid medium with 1.0-1.5% NaCl by the action of methicillin, whereas other strains required higher NaCl concentrations. Further, in 6 of the 7 strains the ability for spontaneous L-phase production was associated with high L-phase productivity in the presence of methicillin. The pattern of alpha-, beta- and delta-hemolysin production in a strain was not correlated to spontaneous L-phase production.

Hemolysin Proteins↗

Self-leveling mortar as a possible cause of symptoms associated with "sick building syndrome".

In newly constructed houses and buildings in which self-leveling mortar containing casein has been used, residents and office employees have noted a bad odor and have complained of headache, eye and throat irritation, and tiredness. These problems were suspected to result from the degradation products emitted from the mortar. Samples obtained from dry mortar powder and from mortar in buildings where casein was used and from control buildings were found to contain microorganisms (mean of 10(2) culture forming units/g). Environmental species were predominantly found, e.g., Bacillus, Clostridium, Micrococcus, and Propionibacterium. Fungi were found occasionally; no evidence of bacterial degradation was found. Headspace and gas chromatographic-mass spectrometric analysis of air from the newly constructed houses and from hydroxide-degraded casein revealed the presence of amines in the 0.003-0.013 ppm range and the presence of ammonia and sulfhydryl compounds, all of which in low concentrations can cause the symptoms observed. These substances, however, were not detected in control buildings.

Air Microbiology↗

Staphylococcus aureus exotoxin has limited and transient effects on cochlear electrophysiology.

Seven ears of Sprague-Dawley rats were exposed to 20 microliters Staphylococcus aureus exotoxin suspension by injection via the tympanic membrane into the round window niche. Another 6 ears were exposed to 20 microliters broth as controls. ABR was performed in the interval 2-31.5 kHz immediately before and 1, 2, 5, 7 and 10 days after the exposure. Although threshold changes could be found in the toxin-exposed group but not the control group in the frequency range 10-20 kHz, there were only statistically significant threshold changes--at 31.5 kHz--on the 1st, 2nd, 5th, and 7th days after the exotoxin injection. S. aureus exotoxin has minor transient but reversible effects on the inner ear, causing chiefly high-frequency threshold and latency changes.

Animals↗