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H Rintala

Publications and source records attributed to H Rintala.

11 recordsLinked to original sources
PubMed2004

Detection of streptomycetes in house dust--comparison of culture and PCR methods.

Streptomycetes are gram-positive, spore producing, filamentous bacteria common in soil, but also present in indoor environments. They are potent producers of secondary metabolites and inducers of inflammatory responses in vitro. Polymerase chain reaction (PCR)- and culture-based detection methods for streptomycetes in house dust samples were compared. A total of 47 dust samples were investigated, and the presence of streptomycetes was determined by cultivation on tryptone-yeast-extract-glucose agar and PCR. The 16S rRNA gene of actinomycete isolates from house dust was partially sequenced to investigate if they belong to the genus Streptomyces. Both PCR and culture showed more frequent occurrence of streptomycetes in moisture-damaged homes, although the results did not correlate well. The occurrence of streptomycetes in house dust was associated with moisture damage of the home. The amount of Streptomyces-specific PCR amplification product was significantly higher in dust from moisture-damaged homes than in homes with no moisture damage (P < 0.05, Mann-Whitney U test). A correlation between streptomycetes and moisture damage, although not statistically significant, was also observed when using binary data, e.g. presence or absence of streptomycetes or moisture damage (P = 0.054 for PCR, and P = 0.127 for culture, Fisher's exact test). Altogether, the presence of streptomycetes in house dust seems to indicate the presence of moisture damage in the building.

Air Pollution, Indoor↗
PubMed2002

Diversity of streptomycetes in water-damaged building materials based on 16S rDNA sequences.

AIMS: The diversity of streptomycetes in two different types of water-damaged building materials was investigated. METHODS AND RESULTS: Direct PCR amplification of 16S rDNA from DNA isolated from building materials, cloning of the fragments and sequence analysis were used. In the phylogenetic analysis of the variable gamma region of the PCR amplification products, the sequences affiliated with five groups. CONCLUSIONS: Several different sequences were found in both materials, suggesting the presence of several species. Also, previously unknown sequences were detected, although all the sequences clustered together with sequences of known species. SIGNIFICANCE AND IMPACT OF THE STUDY: Streptomycetes are known as indicators for moisture and mould damage in buildings and potential health risk, but their diversity in indoor environments is still unknown.

Cloning, Molecular↗
PubMed2001

PCR primers targeting the 16S rRNA gene for the specific detection of streptomycetes.

Streptomycetes are filamentous actinobacteria commonly found in soil and biotechnically important, but they also have adverse effects on human health. In this work, two primer pairs, StrepB/StrepE and StrepB/StrepF combined with Bst YI restriction endonuclease digestion, targeting the 16S rRNA gene of streptomycetes were designed. The specificity of the primers was determined by polymerase chain reaction (PCR) amplification from Streptomyces strains and near relatives. All streptomycetes tested positive and non-streptomycetes were not amplified except three strains that, however, gave Bst YI restriction endonuclease digestion results distinct from streptomycetes. Moreover, both primer pairs gave an amplification product of the expected size only when Streptomyces VTT E-99-1334 DNA was present in the template DNA mixture isolated from six bacterial and three fungal strains. The primers were further successfully used to amplify from DNA isolated from two soil and two building material samples. The 40 sequenced amplification products obtained with the primer pair StrepB/StrepE showed greater than 96.1% similarity to streptomycete 16S rRNA sequences. Seventy PCR amplification products obtained with the primers StrepB/StrepF were analysed by sequencing and restriction analysis. All 54 PCR products having >95.7% similarity to streptomycete sequences were cleaved with Bst YI. No false-positive results were achieved. Both primer sets proved to be specific for streptomycetes, and applicable for the detection of streptomycetes in environmental samples.

DNA Primers↗
PubMed1994

Androgen receptor function during undernutrition.

Hypothalamo-pituitary inhibition of reproductive function during undernutrition is well known, however, the physiological mechanisms leading to suppression of gonadotrophin secretion are not clear. A variety of studies have indicated that testicular negative feedback on LH secretion is enhanced during food restriction. To evaluate directly the suppression by endogenous androgens on hypothalamic GnRH pulse generator activity during food restriction and examine the mechanism underlying the increased testicular steroidal feedback, we examined (1) circulating bioactive LH (bLH) levels in response to selective cerebral androgen blockade by intraventricular administration of an androgen receptor antagonist (hydroxyflutamide, SCH 16423) and (2) the binding capacity and affinity of androgen receptors in medio-basal hypothalamus, pituitary and prostate during undernutrition of intact mature male rats. Hydroxyflutamide (20 micrograms in 10 microliters vehicle), but not vehicle alone, markedly increased bLH levels in both food restricted and ad-lib fed rats. However, the faster (geometric mean 11.4 vs 27.7 min) and greater (47.2 vs 21.9 ng/ml) increase in bLH level in food restricted compared with ad-lib fed controls demonstrates an enhanced sensitivity to blockade of androgenic negative feedback during undernutrition. Food restriction increased androgen receptor binding capacity in pituitary (3.36 vs 0.77 fmol/mg protein) but not in medio-basal hypothalamus or prostate while binding affinity was unchanged by undernutrition in all 3 tissues. These studies reveal that undernutrition both enhances tonic, androgen receptor-mediated feedback suppression of GnRH secretion and increases in pituitary (but not hypothalamic) androgen receptor numbers to cause inhibition of LH secretion.

Androgen Receptor Antagonists↗
PubMed1993

LH pulsatility, biopotency, and clearance during undernutrition in orchidectomized mature rats.

The effect of food restriction on circulating luteinizing hormone (LH) levels in orchidectomized rats is controversial. The present study demonstrates that decreasing food intake by 50% for 3-10 days in orchidectomized rats increases LH pulse amplitude, length, area under pulse curve, and mean levels but decreases LH pulse frequency compared with ad-lib fed, orchidectomized controls. The effects on pulsatile LH secretion of food reduction by 50% with or without dilution by cellulose to maintain food volume in orchidectomized rats were also examined. Food volume influences pulsatile LH secretion independent of macronutrient effect after 3 days of food restriction, but subsequently macronutrient deprivation predominates. The exaggerated increase in LH levels in orchidectomized rats subject to food restriction for 7 days was not due to immunochemical or chromatographic heterogeneity or alteration in biopotency of circulating LH molecules. Intravenously injected 125I-labeled rat LH analyzed by noncompartmental modeling revealed that neither LH clearance nor mean residence time was reduced by food restriction. We conclude that during food restriction in orchidectomized rats, increases in LH pulse amplitude exceed and precede the decreases in LH pulse frequency, although the early changes in pulse amplitude are predominantly due to reduced food volume rather than macronutrient deprivation.

Aging↗
PubMed1989

Heterologous gene expression of the glyphosate resistance marker and its application in yeast transformation.

The E. coli aroA gene was inserted between yeast promoter and terminator sequences in different shuttle expression plasmids and found to confer enhanced EPSP synthase activity as well as resistance to glyphosate toxicity. Subsequently, a transformation system using these newly constructed vectors in yeast was characterized. The efficiency of the glyphosate resistance marker for transformation and selection with plasmid pHR6/20-1 in S. cerevisiae laboratory strain SHY2 was found to be relatively high when compared with selection for LEU2 prototrophy. The fate of the recombinant plasmid pHR6/20-1 in the transformants, the preservation of the aroA E. coli DNA fragment in yeast, mitotic stability, EPSP synthase activity, and growth on glyphosate-containing medium have been investigated. As this plasmid also allows direct selection for glyphosate resistant transformants on rich media, the glyphosate resistance marker was used for transforming both S. cerevisiae laboratory strain SHY2 and brewer's yeast strains S. cerevisiae var. "uvarum" BHS5 and BHS2. In all cases, the vector pHR6/20-1 was maintained as an autonomously replicating plasmid. The resistance marker is, therefore, suitable for transforming genetically unlabelled S. cerevisiae laboratory, wild, and industrial yeast strains.

3-Phosphoshikimate 1-Carboxyvinyltransferase↗
PubMed1984

Breast stimulation test in fetal surveillance.

The usefulness of breast stimulation to elicit uterine contractions as a contraction stress test in fetal surveillance in high-risk pregnancies was investigated. The test was successful in fulfilling the criteria of contraction stress testing in 48 out of 76 mothers (62%). Success rates were not affected by the duration of pregnancy after 36 weeks. Nor did parity have any significant effect. The results of the breast stimulation test (BST) correlated well with the preceding non-stress test. Only one positive BST was detected in this population. In this case the late decelerations were present even during labor the next day. BST seems to be a practicable tool, in preference to the oxytocin challenge test, for fetal surveillance.

Adult↗